diff --git a/-XKsFKIGjZ0.txt b/-XKsFKIGjZ0.txt new file mode 100644 index 0000000000000000000000000000000000000000..a03441dffae2df67ea984249f880505434a856c0 --- /dev/null +++ b/-XKsFKIGjZ0.txt @@ -0,0 +1,2251 @@ +align:start position:0% + +so this is the car in the + + align:start position:0% +so this is the car in the + + + align:start position:0% +so this is the car in the +Department about seven cases now I'm + + align:start position:0% +Department about seven cases now I'm + + + align:start position:0% +Department about seven cases now I'm +we're going to walk to the next + + align:start position:0% +we're going to walk to the next + + + align:start position:0% +we're going to walk to the next +department is called the prefit + + align:start position:0% +department is called the prefit + + + align:start position:0% +department is called the prefit +department part of the value this like + + align:start position:0% +department part of the value this like + + + align:start position:0% +department part of the value this like +the second part of the value stre the + + align:start position:0% +the second part of the value stre the + + + align:start position:0% +the second part of the value stre the +second the value we got the cutting now + + align:start position:0% +second the value we got the cutting now + + + align:start position:0% +second the value we got the cutting now +we're going to do stitching exactly the + + align:start position:0% +we're going to do stitching exactly the + + + align:start position:0% +we're going to do stitching exactly the +pref is a shoe making technique many + + align:start position:0% +pref is a shoe making technique many + + + align:start position:0% +pref is a shoe making technique many +years ago when we didn't have computers + + align:start position:0% +years ago when we didn't have computers + + + align:start position:0% +years ago when we didn't have computers +the way a shoe was stitched is it used + + align:start position:0% +the way a shoe was stitched is it used + + + align:start position:0% +the way a shoe was stitched is it used +to be fitted two parts coming together + + align:start position:0% +to be fitted two parts coming together + + + align:start position:0% +to be fitted two parts coming together +and a very uh skillful stitchers to put + + align:start position:0% +and a very uh skillful stitchers to put + + + align:start position:0% +and a very uh skillful stitchers to put +it together but before be able to brief + + align:start position:0% +it together but before be able to brief + + + align:start position:0% +it together but before be able to brief +it and Stitch in need um be fitted used + + align:start position:0% +it and Stitch in need um be fitted used + + + align:start position:0% +it and Stitch in need um be fitted used +to be pre fitted which is you do marking + + align:start position:0% +to be pre fitted which is you do marking + + + align:start position:0% +to be pre fitted which is you do marking +you do embroidery you do other things + + align:start position:0% +you do embroidery you do other things + + + align:start position:0% +you do embroidery you do other things +before you go the Sho together that's + + align:start position:0% +before you go the Sho together that's + + + align:start position:0% +before you go the Sho together that's +where the name coming from pre so we do + + align:start position:0% +where the name coming from pre so we do + + + align:start position:0% +where the name coming from pre so we do +embroidery we put the + + align:start position:0% +embroidery we put the + + + align:start position:0% +embroidery we put the +logos or main USA logo is there and then + + align:start position:0% +logos or main USA logo is there and then + + + align:start position:0% +logos or main USA logo is there and then +you will see a series of operations + + align:start position:0% +you will see a series of operations + + + align:start position:0% +you will see a series of operations +miscellanous operations that are + + align:start position:0% +miscellanous operations that are + + + align:start position:0% +miscellanous operations that are +required to make a shoe for example + + align:start position:0% +required to make a shoe for example + + + align:start position:0% +required to make a shoe for example +reinforcement of the chip uh I talk + + align:start position:0% +reinforcement of the chip uh I talk + + + align:start position:0% +reinforcement of the chip uh I talk +about embroidery some shells take + + align:start position:0% +about embroidery some shells take + + + align:start position:0% +about embroidery some shells take +embroidery others do + + align:start position:0% +embroidery others do + + + align:start position:0% +embroidery others do +not here we have a machine called AR + + align:start position:0% +not here we have a machine called AR + + + align:start position:0% +not here we have a machine called AR +well radio frequency machine it's not + + align:start position:0% +well radio frequency machine it's not + + + align:start position:0% +well radio frequency machine it's not +being operated right now but as an + + align:start position:0% +being operated right now but as an + + + align:start position:0% +being operated right now but as an +example this is a part it will make this + + align:start position:0% +example this is a part it will make this + + + align:start position:0% +example this is a part it will make this +DEC you know it's a nice + + align:start position:0% +DEC you know it's a nice + + + align:start position:0% +DEC you know it's a nice +feature this what this machine is going + + align:start position:0% +feature this what this machine is going + + + align:start position:0% +feature this what this machine is going +to do again some cells have it some CS + + align:start position:0% +to do again some cells have it some CS + + + align:start position:0% +to do again some cells have it some CS +do not and if we go through the the the + + align:start position:0% +do not and if we go through the the the + + + align:start position:0% +do not and if we go through the the the +the team you'll see Associates making + + align:start position:0% +the team you'll see Associates making + + + align:start position:0% +the team you'll see Associates making +other miscellaneous operations to the + + align:start position:0% +other miscellaneous operations to the + + + align:start position:0% +other miscellaneous operations to the +part to the shoe so the flow of material + + align:start position:0% +part to the shoe so the flow of material + + + align:start position:0% +part to the shoe so the flow of material +starts over there goes to the so we'll + + align:start position:0% +starts over there goes to the so we'll + + + align:start position:0% +starts over there goes to the so we'll +go cutting prit we'll go to the computer + + align:start position:0% +go cutting prit we'll go to the computer + + + align:start position:0% +go cutting prit we'll go to the computer +stitching and we'll finish up stitching + + align:start position:0% +stitching and we'll finish up stitching + + + align:start position:0% +stitching and we'll finish up stitching +and then eventually uh the assembly + + align:start position:0% +and then eventually uh the assembly + + + align:start position:0% +and then eventually uh the assembly +where they put the so on so if if things + + align:start position:0% +where they put the so on so if if things + + + align:start position:0% +where they put the so on so if if things +are getting a little out of uh sequence + + align:start position:0% +are getting a little out of uh sequence + + + align:start position:0% +are getting a little out of uh sequence +timing wise could someone from here go + + align:start position:0% +timing wise could someone from here go + + + align:start position:0% +timing wise could someone from here go +over and help the brief it people this + + align:start position:0% +over and help the brief it people this + + + align:start position:0% +over and help the brief it people this +is this is a very good it's a very good + + align:start position:0% +is this is a very good it's a very good + + + align:start position:0% +is this is a very good it's a very good +point when we change from the bat and Q + + align:start position:0% +point when we change from the bat and Q + + + align:start position:0% +point when we change from the bat and Q +world to the lean world we change the + + align:start position:0% +world to the lean world we change the + + + align:start position:0% +world to the lean world we change the +man agement system in the past you have + + align:start position:0% +man agement system in the past you have + + + align:start position:0% +man agement system in the past you have +uh Associates and supervisors nobody in + + align:start position:0% +uh Associates and supervisors nobody in + + + align:start position:0% +uh Associates and supervisors nobody in +the middle in order to support thex time + + align:start position:0% +the middle in order to support thex time + + + align:start position:0% +the middle in order to support thex time +22 half seconds um and maintain that + + align:start position:0% +22 half seconds um and maintain that + + + align:start position:0% +22 half seconds um and maintain that +flow now we changed the system where we + + align:start position:0% +flow now we changed the system where we + + + align:start position:0% +flow now we changed the system where we +have a supervisor we have team leaders + + align:start position:0% +have a supervisor we have team leaders + + + align:start position:0% +have a supervisor we have team leaders +and then the associate so team leaders + + align:start position:0% +and then the associate so team leaders + + + align:start position:0% +and then the associate so team leaders +feeling if there is a disruption any + + align:start position:0% +feeling if there is a disruption any + + + align:start position:0% +feeling if there is a disruption any +kind bathroom break to a phone call to + + align:start position:0% +kind bathroom break to a phone call to + + + align:start position:0% +kind bathroom break to a phone call to +equality issue they will Champaign to + + align:start position:0% +equality issue they will Champaign to + + + align:start position:0% +equality issue they will Champaign to +maintain their the team leader will + + align:start position:0% +maintain their the team leader will + + + align:start position:0% +maintain their the team leader will +absolutely team later can do everything + + align:start position:0% +absolutely team later can do everything + + + align:start position:0% +absolutely team later can do everything +absolutely so we still in this team in + + align:start position:0% +absolutely so we still in this team in + + + align:start position:0% +absolutely so we still in this team in +the prefit we have bad the parts are pre + + align:start position:0% +the prefit we have bad the parts are pre + + + align:start position:0% +the prefit we have bad the parts are pre +fitted put a a reinforcement to the toe + + align:start position:0% +fitted put a a reinforcement to the toe + + + align:start position:0% +fitted put a a reinforcement to the toe +you make a little de uh you know uh you + + align:start position:0% +you make a little de uh you know uh you + + + align:start position:0% +you make a little de uh you know uh you +put those asso there are making a little + + align:start position:0% +put those asso there are making a little + + + align:start position:0% +put those asso there are making a little +hold on the part they're putting back on + + align:start position:0% +hold on the part they're putting back on + + + align:start position:0% +hold on the part they're putting back on +those bins that we talked before and + + align:start position:0% +those bins that we talked before and + + + align:start position:0% +those bins that we talked before and +brought filling badge to this department + + align:start position:0% +brought filling badge to this department + + + align:start position:0% +brought filling badge to this department +is called computer stitching computer + + align:start position:0% +is called computer stitching computer + + + align:start position:0% +is called computer stitching computer +stitching so what I'm going to show you + + align:start position:0% +stitching so what I'm going to show you + + + align:start position:0% +stitching so what I'm going to show you +right now + + align:start position:0% + + + + align:start position:0% + +are uh stitching + + align:start position:0% +are uh stitching + + + align:start position:0% +are uh stitching +machines but they have a computer and + + align:start position:0% +machines but they have a computer and + + + align:start position:0% +machines but they have a computer and +cameras and the way it works you see an + + align:start position:0% +cameras and the way it works you see an + + + align:start position:0% +cameras and the way it works you see an +associate picking these kind of parts + + align:start position:0% +associate picking these kind of parts + + + align:start position:0% +associate picking these kind of parts +put was called a + + align:start position:0% +put was called a + + + align:start position:0% +put was called a +pallet these little holes that to put on + + align:start position:0% +pallet these little holes that to put on + + + align:start position:0% +pallet these little holes that to put on +pins and the pallet will be fed into + + align:start position:0% +pins and the pallet will be fed into + + + align:start position:0% +pins and the pallet will be fed into +this machine and you have lights taking + + align:start position:0% +this machine and you have lights taking + + + align:start position:0% +this machine and you have lights taking +pictures okay and a computer and taking + + align:start position:0% +pictures okay and a computer and taking + + + align:start position:0% +pictures okay and a computer and taking +a pictures three frames per second so + + align:start position:0% +a pictures three frames per second so + + + align:start position:0% +a pictures three frames per second so +the camera thr the computer this is The + + align:start position:0% +the camera thr the computer this is The + + + align:start position:0% +the camera thr the computer this is The +Edge and the computer tell the sewing + + align:start position:0% +Edge and the computer tell the sewing + + + align:start position:0% +Edge and the computer tell the sewing +machine where to put the Stitch okay + + align:start position:0% +machine where to put the Stitch okay + + + align:start position:0% +machine where to put the Stitch okay +okay okay at this computer stitching + + align:start position:0% +okay okay at this computer stitching + + + align:start position:0% +okay okay at this computer stitching +department is when we transition from + + align:start position:0% +department is when we transition from + + + align:start position:0% +department is when we transition from +the badge to the FL and that's what I'm + + align:start position:0% +the badge to the FL and that's what I'm + + + align:start position:0% +the badge to the FL and that's what I'm +going to show you okay + + align:start position:0% +going to show you okay + + + align:start position:0% +going to show you okay +great this associate here I I forgot to + + align:start position:0% +great this associate here I I forgot to + + + align:start position:0% +great this associate here I I forgot to +mention we talk about the different + + align:start position:0% +mention we talk about the different + + + align:start position:0% +mention we talk about the different +management system remember tag time flow + + align:start position:0% +management system remember tag time flow + + + align:start position:0% +management system remember tag time flow +supervisor team leader to help but also + + align:start position:0% +supervisor team leader to help but also + + + align:start position:0% +supervisor team leader to help but also +we want associ to be on the line + + align:start position:0% +we want associ to be on the line + + + align:start position:0% +we want associ to be on the line +producing the shoes at that tag time so + + align:start position:0% +producing the shoes at that tag time so + + + align:start position:0% +producing the shoes at that tag time so +another level is called the point of + + align:start position:0% +another level is called the point of + + + align:start position:0% +another level is called the point of +views okay asso the the goal point of + + align:start position:0% +views okay asso the the goal point of + + + align:start position:0% +views okay asso the the goal point of +view is to bring the parts to okay The + + align:start position:0% +view is to bring the parts to okay The + + + align:start position:0% +view is to bring the parts to okay The +Operators actually adding value to the + + align:start position:0% +Operators actually adding value to the + + + align:start position:0% +Operators actually adding value to the +shoe so this lady's a point of use + + align:start position:0% +shoe so this lady's a point of use + + + align:start position:0% +shoe so this lady's a point of use +associ called a point of use associ look + + align:start position:0% +associ called a point of use associ look + + + align:start position:0% +associ called a point of use associ look +pretty busy too very busy they have to + + align:start position:0% +pretty busy too very busy they have to + + + align:start position:0% +pretty busy too very busy they have to +distribute you know in case a case every + + align:start position:0% +distribute you know in case a case every + + + align:start position:0% +distribute you know in case a case every +9 minutes and they have uh a flow + + align:start position:0% +9 minutes and they have uh a flow + + + align:start position:0% +9 minutes and they have uh a flow +from this computer stitching into the + + align:start position:0% +from this computer stitching into the + + + align:start position:0% +from this computer stitching into the +next department and come back and flow + + align:start position:0% +next department and come back and flow + + + align:start position:0% +next department and come back and flow +everything is about flow so you want to + + align:start position:0% +everything is about flow so you want to + + + align:start position:0% +everything is about flow so you want to +keep this person want to have everything + + align:start position:0% +keep this person want to have everything + + + align:start position:0% +keep this person want to have everything +she needs to do what she needs to do + + align:start position:0% +she needs to do what she needs to do + + + align:start position:0% +she needs to do what she needs to do +exactly exactly this person in the past + + align:start position:0% +exactly exactly this person in the past + + + align:start position:0% +exactly exactly this person in the past +in the past world this person will leave + + align:start position:0% +in the past world this person will leave + + + align:start position:0% +in the past world this person will leave +the machine we go pick up the parts come + + align:start position:0% +the machine we go pick up the parts come + + + align:start position:0% +the machine we go pick up the parts come +back um lot of variability in the system + + align:start position:0% +back um lot of variability in the system + + + align:start position:0% +back um lot of variability in the system +and reduction of waste is to reduce + + align:start position:0% +and reduction of waste is to reduce + + + align:start position:0% +and reduction of waste is to reduce +variability at the same time they must + + align:start position:0% +variability at the same time they must + + + align:start position:0% +variability at the same time they must +have to work very closely together yes + + align:start position:0% +have to work very closely together yes + + + align:start position:0% +have to work very closely together yes +absolutely so here you have the computer + + align:start position:0% +absolutely so here you have the computer + + + align:start position:0% +absolutely so here you have the computer +stitching machine um these are the parts + + align:start position:0% +stitching machine um these are the parts + + + align:start position:0% +stitching machine um these are the parts +that came from The + + align:start position:0% + + + + align:start position:0% + +Cutting and the associate puts the parts + + align:start position:0% +Cutting and the associate puts the parts + + + align:start position:0% +Cutting and the associate puts the parts +on this + + align:start position:0% +on this + + + align:start position:0% +on this +pallet is feding to the machine goes + + align:start position:0% +pallet is feding to the machine goes + + + align:start position:0% +pallet is feding to the machine goes +back in the machine you got the + + align:start position:0% +back in the machine you got the + + + align:start position:0% +back in the machine you got the +cameras taking pictur now it's stitching + + align:start position:0% +cameras taking pictur now it's stitching + + + align:start position:0% +cameras taking pictur now it's stitching +and then the sewing machines stitching + + align:start position:0% +and then the sewing machines stitching + + + align:start position:0% +and then the sewing machines stitching +where the computer s to + + align:start position:0% + + + + align:start position:0% + +stitch they probably come + + align:start position:0% + + + + align:start position:0% + +up here we got the part + + align:start position:0% + + + + align:start position:0% + +okay now why only three parts is because + + align:start position:0% +okay now why only three parts is because + + + align:start position:0% +okay now why only three parts is because +under the T time of 2 2 and2 seconds + + align:start position:0% +under the T time of 2 2 and2 seconds + + + align:start position:0% +under the T time of 2 2 and2 seconds +that solid fits in this machine okay so + + align:start position:0% +that solid fits in this machine okay so + + + align:start position:0% +that solid fits in this machine okay so +we look at we take all the time that is + + align:start position:0% +we look at we take all the time that is + + + align:start position:0% +we look at we take all the time that is +required to stit a shoe we divide it by + + align:start position:0% +required to stit a shoe we divide it by + + + align:start position:0% +required to stit a shoe we divide it by +2 and 2 and a half seconds and that + + align:start position:0% +2 and 2 and a half seconds and that + + + align:start position:0% +2 and 2 and a half seconds and that +tells us how many asso we need to put to + + align:start position:0% +tells us how many asso we need to put to + + + align:start position:0% +tells us how many asso we need to put to +flow now when you switch to the tack + + align:start position:0% +flow now when you switch to the tack + + + align:start position:0% +flow now when you switch to the tack +time uh approach did you have to + + align:start position:0% +time uh approach did you have to + + + align:start position:0% +time uh approach did you have to +redesign some of these machines to + + align:start position:0% +redesign some of these machines to + + + align:start position:0% +redesign some of these machines to +completely okay in the the old machines + + align:start position:0% +completely okay in the the old machines + + + align:start position:0% +completely okay in the the old machines +didn't fit the tax I'm sorry the + + align:start position:0% +didn't fit the tax I'm sorry the + + + align:start position:0% +didn't fit the tax I'm sorry the +machines are okay we have to change the + + align:start position:0% +machines are okay we have to change the + + + align:start position:0% +machines are okay we have to change the +thinking of the designing of the pallets + + align:start position:0% +thinking of the designing of the pallets + + + align:start position:0% +thinking of the designing of the pallets +okay in the past in the B and and and Q + + align:start position:0% +okay in the past in the B and and and Q + + + align:start position:0% +okay in the past in the B and and and Q +world we were very proud when we could + + align:start position:0% +world we were very proud when we could + + + align:start position:0% +world we were very proud when we could +put as many layers as possible to save + + align:start position:0% +put as many layers as possible to save + + + align:start position:0% +put as many layers as possible to save +Machinery okay uh the Goos and machine + + align:start position:0% +Machinery okay uh the Goos and machine + + + align:start position:0% +Machinery okay uh the Goos and machine +efficiency right because you get reward + + align:start position:0% +efficiency right because you get reward + + + align:start position:0% +efficiency right because you get reward +in the in the Bat World for machine + + align:start position:0% +in the in the Bat World for machine + + + align:start position:0% +in the in the Bat World for machine +efficiency right now now the goal is + + align:start position:0% +efficiency right now now the goal is + + + align:start position:0% +efficiency right now now the goal is +into efficiency and + + align:start position:0% +into efficiency and + + + align:start position:0% +into efficiency and +Association okay so what we did is now + + align:start position:0% +Association okay so what we did is now + + + align:start position:0% +Association okay so what we did is now +we don't pack as many players as we can + + align:start position:0% +we don't pack as many players as we can + + + align:start position:0% +we don't pack as many players as we can +we only put enough layers to maintain + + align:start position:0% +we only put enough layers to maintain + + + align:start position:0% +we only put enough layers to maintain +flow the machine the same but the design + + align:start position:0% +flow the machine the same but the design + + + align:start position:0% +flow the machine the same but the design +of the pallet and the number of parts + + align:start position:0% +of the pallet and the number of parts + + + align:start position:0% +of the pallet and the number of parts +has changed radically very good and did + + align:start position:0% +has changed radically very good and did + + + align:start position:0% +has changed radically very good and did +and did the associates participate in + + align:start position:0% +and did the associates participate in + + + align:start position:0% +and did the associates participate in +that redesign oh absolutely I that's a + + align:start position:0% +that redesign oh absolutely I that's a + + + align:start position:0% +that redesign oh absolutely I that's a +great question I we talk about the team + + align:start position:0% +great question I we talk about the team + + + align:start position:0% +great question I we talk about the team +leaders that's one of the major major + + align:start position:0% +leaders that's one of the major major + + + align:start position:0% +leaders that's one of the major major +changes that you know we reading the + + align:start position:0% +changes that you know we reading the + + + align:start position:0% +changes that you know we reading the +books about ass Bas assets and I know we + + align:start position:0% +books about ass Bas assets and I know we + + + align:start position:0% +books about ass Bas assets and I know we +I think we're working you know uh + + align:start position:0% +I think we're working you know uh + + + align:start position:0% +I think we're working you know uh +talking about we also you know we doing + + align:start position:0% +talking about we also you know we doing + + + align:start position:0% +talking about we also you know we doing +great things here where Associates have + + align:start position:0% +great things here where Associates have + + + align:start position:0% +great things here where Associates have +in great part you know in the uh in the + + align:start position:0% +in great part you know in the uh in the + + + align:start position:0% +in great part you know in the uh in the +problem solving activity the design + + align:start position:0% +problem solving activity the design + + + align:start position:0% +problem solving activity the design +supervisors and team leaders consult + + align:start position:0% +supervisors and team leaders consult + + + align:start position:0% +supervisors and team leaders consult +them all the time uh that's going to + + align:start position:0% +them all the time uh that's going to + + + align:start position:0% +them all the time uh that's going to +makes a big big difference before we + + align:start position:0% +makes a big big difference before we + + + align:start position:0% +makes a big big difference before we +talk about that now you see single ke + + align:start position:0% +talk about that now you see single ke + + + align:start position:0% +talk about that now you see single ke +flow you have flow yep so we got a sell + + align:start position:0% +flow you have flow yep so we got a sell + + + align:start position:0% +flow you have flow yep so we got a sell +here have you have a cell exactly I mean + + align:start position:0% +here have you have a cell exactly I mean + + + align:start position:0% +here have you have a cell exactly I mean +this is a very good + + align:start position:0% +this is a very good + + + align:start position:0% +this is a very good +graphical realization of a cell you can + + align:start position:0% +graphical realization of a cell you can + + + align:start position:0% +graphical realization of a cell you can +see it all connected together it's a + + align:start position:0% +see it all connected together it's a + + + align:start position:0% +see it all connected together it's a +good point this is a good example of + + align:start position:0% +good point this is a good example of + + + align:start position:0% +good point this is a good example of +flowing of flowing and we ask them to + + align:start position:0% +flowing of flowing and we ask them to + + + align:start position:0% +flowing of flowing and we ask them to +not to have more than two pairs it says + + align:start position:0% +not to have more than two pairs it says + + + align:start position:0% +not to have more than two pairs it says +right there two pairs only two pairs + + align:start position:0% +right there two pairs only two pairs + + + align:start position:0% +right there two pairs only two pairs +only + + align:start position:0% +only + + + align:start position:0% +only +um Y and you got you got you got some + + align:start position:0% +um Y and you got you got you got some + + + align:start position:0% +um Y and you got you got you got some +visual work instructions here absolutely + + align:start position:0% +visual work instructions here absolutely + + + align:start position:0% +visual work instructions here absolutely +is that's part of the standarized work + + align:start position:0% +is that's part of the standarized work + + + align:start position:0% +is that's part of the standarized work +where we def find the stand ized web and + + align:start position:0% +where we def find the stand ized web and + + + align:start position:0% +where we def find the stand ized web and +visual management is big part of it and + + align:start position:0% +visual management is big part of it and + + + align:start position:0% +visual management is big part of it and +if if you have more if I see three pairs + + align:start position:0% +if if you have more if I see three pairs + + + align:start position:0% +if if you have more if I see three pairs +you know there a problem this asso + + align:start position:0% +you know there a problem this asso + + + align:start position:0% +you know there a problem this asso +problem is having problem the flow + + align:start position:0% +problem is having problem the flow + + + align:start position:0% +problem is having problem the flow +coordinator we call the flow coordinator + + align:start position:0% +coordinator we call the flow coordinator + + + align:start position:0% +coordinator we call the flow coordinator +the team leaders we call them flow + + align:start position:0% +the team leaders we call them flow + + + align:start position:0% +the team leaders we call them flow +coordinator coordinat yeah then we come + + align:start position:0% +coordinator coordinat yeah then we come + + + align:start position:0% +coordinator coordinat yeah then we come +up with that's much better than team + + align:start position:0% +up with that's much better than team + + + align:start position:0% +up with that's much better than team +leader yes um because the goal is to + + align:start position:0% +leader yes um because the goal is to + + + align:start position:0% +leader yes um because the goal is to +maintain the flow in a way well the + + align:start position:0% +maintain the flow in a way well the + + + align:start position:0% +maintain the flow in a way well the +title flow coordinator means team leader + + align:start position:0% +title flow coordinator means team leader + + + align:start position:0% +title flow coordinator means team leader +focuses on them FL coordinator focuses + + align:start position:0% +focuses on them FL coordinator focuses + + + align:start position:0% +focuses on them FL coordinator focuses +on what they're doing exactly exactly so + + align:start position:0% +on what they're doing exactly exactly so + + + align:start position:0% +on what they're doing exactly exactly so +so visually if you see three pair the + + align:start position:0% +so visually if you see three pair the + + + align:start position:0% +so visually if you see three pair the +floor for will come you know something + + align:start position:0% +floor for will come you know something + + + align:start position:0% +floor for will come you know something +is not right so uh visually it's very + + align:start position:0% +is not right so uh visually it's very + + + align:start position:0% +is not right so uh visually it's very +powerful so AIO I see some little red + + align:start position:0% +powerful so AIO I see some little red + + + align:start position:0% +powerful so AIO I see some little red +dots over say red color labels what are + + align:start position:0% +dots over say red color labels what are + + + align:start position:0% +dots over say red color labels what are +those for it could be that um this + + align:start position:0% +those for it could be that um this + + + align:start position:0% +those for it could be that um this +machine sometime are very sensitive to + + align:start position:0% +machine sometime are very sensitive to + + + align:start position:0% +machine sometime are very sensitive to +um to the shape of the part because you + + align:start position:0% +um to the shape of the part because you + + + align:start position:0% +um to the shape of the part because you +take a picture and the part is sort of + + align:start position:0% +take a picture and the part is sort of + + + align:start position:0% +take a picture and the part is sort of +warp it pulls the machine so in sh + + align:start position:0% +warp it pulls the machine so in sh + + + align:start position:0% +warp it pulls the machine so in sh +making technology we can have a stage + + align:start position:0% +making technology we can have a stage + + + align:start position:0% +making technology we can have a stage +run up so the associ put a little red + + align:start position:0% +run up so the associ put a little red + + + align:start position:0% +run up so the associ put a little red +dot and it goes by the flowable noce fix + + align:start position:0% +dot and it goes by the flowable noce fix + + + align:start position:0% +dot and it goes by the flowable noce fix +it quickly and put it back into the line + + align:start position:0% +it quickly and put it back into the line + + + align:start position:0% +it quickly and put it back into the line +now is that something that came out of + + align:start position:0% +now is that something that came out of + + + align:start position:0% +now is that something that came out of +an employee suggestion probably yeah and + + align:start position:0% +an employee suggestion probably yeah and + + + align:start position:0% +an employee suggestion probably yeah and +they they' like to have that and they + + align:start position:0% +they they' like to have that and they + + + align:start position:0% +they they' like to have that and they +identify themselves you know at least + + align:start position:0% +identify themselves you know at least + + + align:start position:0% +identify themselves you know at least +the defect is there but they take + + align:start position:0% +the defect is there but they take + + + align:start position:0% +the defect is there but they take +ownership that's a big thing that + + align:start position:0% +ownership that's a big thing that + + + align:start position:0% +ownership that's a big thing that +changed in the past they were trying to + + align:start position:0% +changed in the past they were trying to + + + align:start position:0% +changed in the past they were trying to +you know we had inspectors at the line + + align:start position:0% +you know we had inspectors at the line + + + align:start position:0% +you know we had inspectors at the line +putting the do now defs happen but now + + align:start position:0% +putting the do now defs happen but now + + + align:start position:0% +putting the do now defs happen but now +they have hhip and and we I'm very proud + + align:start position:0% +they have hhip and and we I'm very proud + + + align:start position:0% +they have hhip and and we I'm very proud +We we created really uh an environment + + align:start position:0% +We we created really uh an environment + + + align:start position:0% +We we created really uh an environment +that it's okay + + align:start position:0% +that it's okay + + + align:start position:0% +that it's okay +uh to show the mistakes and it's not + + align:start position:0% +uh to show the mistakes and it's not + + + align:start position:0% +uh to show the mistakes and it's not +it's not problem they're happy oh not a + + align:start position:0% +it's not problem they're happy oh not a + + + align:start position:0% +it's not problem they're happy oh not a +problem and very interestingly when we + + align:start position:0% +problem and very interestingly when we + + + align:start position:0% +problem and very interestingly when we +change from the bats to the lean uh + + align:start position:0% +change from the bats to the lean uh + + + align:start position:0% +change from the bats to the lean uh +standards are very important + + align:start position:0% +standards are very important + + + align:start position:0% +standards are very important +standardized work which is the + + align:start position:0% +standardized work which is the + + + align:start position:0% +standardized work which is the +definition sort of the best uh flow of + + align:start position:0% +definition sort of the best uh flow of + + + align:start position:0% +definition sort of the best uh flow of +product considering cost policy and + + align:start position:0% +product considering cost policy and + + + align:start position:0% +product considering cost policy and +economics and some people thought well + + align:start position:0% +economics and some people thought well + + + align:start position:0% +economics and some people thought well +if I have to do always the same uh + + align:start position:0% +if I have to do always the same uh + + + align:start position:0% +if I have to do always the same uh +management was concerned that associate + + align:start position:0% +management was concerned that associate + + + align:start position:0% +management was concerned that associate +with feel like robot and feedback that + + align:start position:0% +with feel like robot and feedback that + + + align:start position:0% +with feel like robot and feedback that +we got after few months of lean + + align:start position:0% +we got after few months of lean + + + align:start position:0% +we got after few months of lean +implementation is that they love to know + + align:start position:0% +implementation is that they love to know + + + align:start position:0% +implementation is that they love to know +what they have to do so management and + + align:start position:0% +what they have to do so management and + + + align:start position:0% +what they have to do so management and +even human + + align:start position:0% +even human + + + align:start position:0% +even human +resources concept that they would feel + + align:start position:0% +resources concept that they would feel + + + align:start position:0% +resources concept that they would feel +like robot was not correct and um what + + align:start position:0% +like robot was not correct and um what + + + align:start position:0% +like robot was not correct and um what +we trying to teach them is that sort of + + align:start position:0% +we trying to teach them is that sort of + + + align:start position:0% +we trying to teach them is that sort of +a paradox because standardized work + + align:start position:0% +a paradox because standardized work + + + align:start position:0% +a paradox because standardized work +always have to do the same thing + + align:start position:0% +always have to do the same thing + + + align:start position:0% +always have to do the same thing +but as you do always the same thing you + + align:start position:0% +but as you do always the same thing you + + + align:start position:0% +but as you do always the same thing you +have a foundation for problem solving + + align:start position:0% +have a foundation for problem solving + + + align:start position:0% +have a foundation for problem solving +for continuous Improvement so + + align:start position:0% +for continuous Improvement so + + + align:start position:0% +for continuous Improvement so +standardized work is a continuous + + align:start position:0% +standardized work is a continuous + + + align:start position:0% +standardized work is a continuous +improvement tool impr very it depends + + align:start position:0% +improvement tool impr very it depends + + + align:start position:0% +improvement tool impr very it depends +how you look at them so through that + + align:start position:0% +how you look at them so through that + + + align:start position:0% +how you look at them so through that +repetition they will recommend uh + + align:start position:0% +repetition they will recommend uh + + + align:start position:0% +repetition they will recommend uh +changes that's a really interesting + + align:start position:0% +changes that's a really interesting + + + align:start position:0% +changes that's a really interesting +approach because that makes standardized + + align:start position:0% +approach because that makes standardized + + + align:start position:0% +approach because that makes standardized +work be something where you're always + + align:start position:0% +work be something where you're always + + + align:start position:0% +work be something where you're always +trying to improve it compared to now we + + align:start position:0% +trying to improve it compared to now we + + + align:start position:0% +trying to improve it compared to now we +can forget about it right AB well that's + + align:start position:0% +can forget about it right AB well that's + + + align:start position:0% +can forget about it right AB well that's +the thing sometime we go crazy never + + align:start position:0% +the thing sometime we go crazy never + + + align:start position:0% +the thing sometime we go crazy never +stops once you get those spr rewi for + + align:start position:0% +stops once you get those spr rewi for + + + align:start position:0% +stops once you get those spr rewi for +continuous Improvement never stop then + + align:start position:0% +continuous Improvement never stop then + + + align:start position:0% +continuous Improvement never stop then +the goal of management is really change + + align:start position:0% +the goal of management is really change + + + align:start position:0% +the goal of management is really change +uh + + align:start position:0% +uh + + + align:start position:0% +uh +radically um manage managers become more + + align:start position:0% +radically um manage managers become more + + + align:start position:0% +radically um manage managers become more +of teachers and coaches coaches always + + align:start position:0% +of teachers and coaches coaches always + + + align:start position:0% +of teachers and coaches coaches always +um challenging the thinking always uh + + align:start position:0% +um challenging the thinking always uh + + + align:start position:0% +um challenging the thinking always uh +production manag called they always have + + align:start position:0% +production manag called they always have + + + align:start position:0% +production manag called they always have +to uh put have like gentle tension you + + align:start position:0% +to uh put have like gentle tension you + + + align:start position:0% +to uh put have like gentle tension you +you will not in my experience or what I + + align:start position:0% +you will not in my experience or what I + + + align:start position:0% +you will not in my experience or what I +read you will not introduce link without + + align:start position:0% +read you will not introduce link without + + + align:start position:0% +read you will not introduce link without +that tension you know it's it's it's a + + align:start position:0% +that tension you know it's it's it's a + + + align:start position:0% +that tension you know it's it's it's a +you know it's like I read somewhere else + + align:start position:0% +you know it's like I read somewhere else + + + align:start position:0% +you know it's like I read somewhere else +you know this is like a pressure cooker + + align:start position:0% +you know this is like a pressure cooker + + + align:start position:0% +you know this is like a pressure cooker +it's always pressure to just has + + align:start position:0% +it's always pressure to just has + + + align:start position:0% +it's always pressure to just has +released the very good analys great + + align:start position:0% +released the very good analys great + + + align:start position:0% +released the very good analys great +right we should move on yes so here you + + align:start position:0% +right we should move on yes so here you + + + align:start position:0% +right we should move on yes so here you +got the uh the case ready for the next + + align:start position:0% +got the uh the case ready for the next + + + align:start position:0% +got the uh the case ready for the next +Department + + align:start position:0% +Department + + + align:start position:0% +Department +okay and the case will be sent to the + + align:start position:0% +okay and the case will be sent to the + + + align:start position:0% +okay and the case will be sent to the +stitching department so I think we + + align:start position:0% +stitching department so I think we + + + align:start position:0% +stitching department so I think we +should go around and I'll show you from + + align:start position:0% +should go around and I'll show you from + + + align:start position:0% +should go around and I'll show you from +the beginning okay very + + align:start position:0% + + + + align:start position:0% + +good \ No newline at end of file diff --git a/-yo3YxfY47g.txt b/-yo3YxfY47g.txt new file mode 100644 index 0000000000000000000000000000000000000000..7a0e71800f14201aee4b3e22ff05eac3edd3ea28 --- /dev/null +++ b/-yo3YxfY47g.txt @@ -0,0 +1,2331 @@ +align:start position:0% + +the law of large numbers gives a precise + + align:start position:0% +the law of large numbers gives a precise + + + align:start position:0% +the law of large numbers gives a precise +formal statement of the basic intuitive + + align:start position:0% +formal statement of the basic intuitive + + + align:start position:0% +formal statement of the basic intuitive +idea that underlies probability theory + + align:start position:0% +idea that underlies probability theory + + + align:start position:0% +idea that underlies probability theory +and in particular our interest in random + + align:start position:0% +and in particular our interest in random + + + align:start position:0% +and in particular our interest in random +variables and their expectations their + + align:start position:0% +variables and their expectations their + + + align:start position:0% +variables and their expectations their +means so let's begin by asking what the + + align:start position:0% +means so let's begin by asking what the + + + align:start position:0% +means so let's begin by asking what the +mean means why are we so interested in + + align:start position:0% +mean means why are we so interested in + + + align:start position:0% +mean means why are we so interested in +it for example if you roll a fair die + + align:start position:0% +it for example if you roll a fair die + + + align:start position:0% +it for example if you roll a fair die +with heads with faces one through six + + align:start position:0% +with heads with faces one through six + + + align:start position:0% +with heads with faces one through six +the mean value it's expected value is + + align:start position:0% +the mean value it's expected value is + + + align:start position:0% +the mean value it's expected value is +three and a half and you'll never roll + + align:start position:0% +three and a half and you'll never roll + + + align:start position:0% +three and a half and you'll never roll +three and a half because there is no + + align:start position:0% +three and a half because there is no + + + align:start position:0% +three and a half because there is no +three and a half face so why do we care + + align:start position:0% +three and a half face so why do we care + + + align:start position:0% +three and a half face so why do we care +about what this mean is if we're never + + align:start position:0% +about what this mean is if we're never + + + align:start position:0% +about what this mean is if we're never +going to roll it and the answer is that + + align:start position:0% +going to roll it and the answer is that + + + align:start position:0% +going to roll it and the answer is that +we believe that after many rolls if we + + align:start position:0% +we believe that after many rolls if we + + + align:start position:0% +we believe that after many rolls if we +take the average of the numbers that + + align:start position:0% +take the average of the numbers that + + + align:start position:0% +take the average of the numbers that +show on the dice that average is going + + align:start position:0% +show on the dice that average is going + + + align:start position:0% +show on the dice that average is going +to be near the mean it's gonna be near + + align:start position:0% +to be near the mean it's gonna be near + + + align:start position:0% +to be near the mean it's gonna be near +three and a half let's look at an even + + align:start position:0% +three and a half let's look at an even + + + align:start position:0% +three and a half let's look at an even +more basic example we if it's a fair die + + align:start position:0% +more basic example we if it's a fair die + + + align:start position:0% +more basic example we if it's a fair die +the probability of rolling a six as with + + align:start position:0% +the probability of rolling a six as with + + + align:start position:0% +the probability of rolling a six as with +any other number is 1/6 and the very + + align:start position:0% +any other number is 1/6 and the very + + + align:start position:0% +any other number is 1/6 and the very +meaning of the fact that the probability + + align:start position:0% +meaning of the fact that the probability + + + align:start position:0% +meaning of the fact that the probability +of rolling a six is 1/6 is that we + + align:start position:0% +of rolling a six is 1/6 is that we + + + align:start position:0% +of rolling a six is 1/6 is that we +expect that if you roll a lot of times + + align:start position:0% +expect that if you roll a lot of times + + + align:start position:0% +expect that if you roll a lot of times +if you roll about n times the fraction + + align:start position:0% +if you roll about n times the fraction + + + align:start position:0% +if you roll about n times the fraction +of sixes is going to be around and over + + align:start position:0% +of sixes is going to be around and over + + + align:start position:0% +of sixes is going to be around and over +six the fraction of six is going to be + + align:start position:0% +six the fraction of six is going to be + + + align:start position:0% +six the fraction of six is going to be +about one-sixth that of n rolls you'll + + align:start position:0% +about one-sixth that of n rolls you'll + + + align:start position:0% +about one-sixth that of n rolls you'll +get about n over six sixes that's that's + + align:start position:0% +get about n over six sixes that's that's + + + align:start position:0% +get about n over six sixes that's that's +almost the definition or the intuitive + + align:start position:0% +almost the definition or the intuitive + + + align:start position:0% +almost the definition or the intuitive +idea behind what we mean when we assign + + align:start position:0% +idea behind what we mean when we assign + + + align:start position:0% +idea behind what we mean when we assign +probability to some outcome it's that if + + align:start position:0% +probability to some outcome it's that if + + + align:start position:0% +probability to some outcome it's that if +we did it repeatedly the fraction of + + align:start position:0% +we did it repeatedly the fraction of + + + align:start position:0% +we did it repeatedly the fraction of +times that it came up would be equal to + + align:start position:0% +times that it came up would be equal to + + + align:start position:0% +times that it came up would be equal to +its probability or at least closely + + align:start position:0% +its probability or at least closely + + + align:start position:0% +its probability or at least closely +equal to it in the long run + + align:start position:0% +equal to it in the long run + + + align:start position:0% +equal to it in the long run +so let's look at what Jacob Bernoulli + + align:start position:0% +so let's look at what Jacob Bernoulli + + + align:start position:0% +so let's look at what Jacob Bernoulli +who is the discoverer of the law of + + align:start position:0% +who is the discoverer of the law of + + + align:start position:0% +who is the discoverer of the law of +large numbers had to say on the subject + + align:start position:0% +large numbers had to say on the subject + + + align:start position:0% +large numbers had to say on the subject +he was born in 1659 died in 1705 and his + + align:start position:0% +he was born in 1659 died in 1705 and his + + + align:start position:0% +he was born in 1659 died in 1705 and his +famous book the art of guessing are as + + align:start position:0% +famous book the art of guessing are as + + + align:start position:0% +famous book the art of guessing are as +konjac Tandy was actually published + + align:start position:0% +konjac Tandy was actually published + + + align:start position:0% +konjac Tandy was actually published +posthumously by his cousin and he said + + align:start position:0% +posthumously by his cousin and he said + + + align:start position:0% +posthumously by his cousin and he said +Bernoulli says even the stupidest man by + + align:start position:0% +Bernoulli says even the stupidest man by + + + align:start position:0% +Bernoulli says even the stupidest man by +some instinct of nature per se and by no + + align:start position:0% +some instinct of nature per se and by no + + + align:start position:0% +some instinct of nature per se and by no +previous instruction this is truly a + + align:start position:0% +previous instruction this is truly a + + + align:start position:0% +previous instruction this is truly a +knows for sure that the more + + align:start position:0% +knows for sure that the more + + + align:start position:0% +knows for sure that the more +observations that are taken the less the + + align:start position:0% +observations that are taken the less the + + + align:start position:0% +observations that are taken the less the +danger will be of straying from the mark + + align:start position:0% +danger will be of straying from the mark + + + align:start position:0% +danger will be of straying from the mark +all right what does he mean well like + + align:start position:0% +all right what does he mean well like + + + align:start position:0% +all right what does he mean well like +it's what we said a moment ago if you + + align:start position:0% +it's what we said a moment ago if you + + + align:start position:0% +it's what we said a moment ago if you +roll the fair die n times and the + + align:start position:0% +roll the fair die n times and the + + + align:start position:0% +roll the fair die n times and the +probability of a roll of is 1/6 then the + + align:start position:0% +probability of a roll of is 1/6 then the + + + align:start position:0% +probability of a roll of is 1/6 then the +average number of sixes which is the + + align:start position:0% +average number of sixes which is the + + + align:start position:0% +average number of sixes which is the +number of sixes rolled divided by n we + + align:start position:0% +number of sixes rolled divided by n we + + + align:start position:0% +number of sixes rolled divided by n we +believe intuitively that that number is + + align:start position:0% +believe intuitively that that number is + + + align:start position:0% +believe intuitively that that number is +gonna approach 1/6 as n approaches + + align:start position:0% +gonna approach 1/6 as n approaches + + + align:start position:0% +gonna approach 1/6 as n approaches +infinity + + align:start position:0% +infinity + + + align:start position:0% +infinity +that's what Bernoulli is saying that + + align:start position:0% +that's what Bernoulli is saying that + + + align:start position:0% +that's what Bernoulli is saying that +everybody understands that they + + align:start position:0% +everybody understands that they + + + align:start position:0% +everybody understands that they +intuitively are sure of it and who knows + + align:start position:0% +intuitively are sure of it and who knows + + + align:start position:0% +intuitively are sure of it and who knows +how they figure that out but that's what + + align:start position:0% +how they figure that out but that's what + + + align:start position:0% +how they figure that out but that's what +everyone thinks and he might be right + + align:start position:0% +everyone thinks and he might be right + + + align:start position:0% +everyone thinks and he might be right +now of course when you're doing this + + align:start position:0% +now of course when you're doing this + + + align:start position:0% +now of course when you're doing this +experiment of rolling n times and + + align:start position:0% +experiment of rolling n times and + + + align:start position:0% +experiment of rolling n times and +Counting the number of six and seeing if + + align:start position:0% +Counting the number of six and seeing if + + + align:start position:0% +Counting the number of six and seeing if +the fraction is close to 1/6 you might + + align:start position:0% +the fraction is close to 1/6 you might + + + align:start position:0% +the fraction is close to 1/6 you might +be unlucky and it's possible that you'd + + align:start position:0% +be unlucky and it's possible that you'd + + + align:start position:0% +be unlucky and it's possible that you'd +get an average that actually was way off + + align:start position:0% +get an average that actually was way off + + + align:start position:0% +get an average that actually was way off +1/6 but that would be unlucky and the + + align:start position:0% +1/6 but that would be unlucky and the + + + align:start position:0% +1/6 but that would be unlucky and the +question is how unlikely is it B is it + + align:start position:0% +question is how unlikely is it B is it + + + align:start position:0% +question is how unlikely is it B is it +to be that you'd get a number of a + + align:start position:0% +to be that you'd get a number of a + + + align:start position:0% +to be that you'd get a number of a +fraction of sixes that wasn't really + + align:start position:0% +fraction of sixes that wasn't really + + + align:start position:0% +fraction of sixes that wasn't really +close to 1/6 and with the law of large + + align:start position:0% +close to 1/6 and with the law of large + + + align:start position:0% +close to 1/6 and with the law of large +numbers is getting a grip on that and in + + align:start position:0% +numbers is getting a grip on that and in + + + align:start position:0% +numbers is getting a grip on that and in +fact subsequently we'll get a more even + + align:start position:0% +fact subsequently we'll get a more even + + + align:start position:0% +fact subsequently we'll get a more even +quantitative grip on it which will be + + align:start position:0% +quantitative grip on it which will be + + + align:start position:0% +quantitative grip on it which will be +crucial for applications in sampling and + + align:start position:0% +crucial for applications in sampling and + + + align:start position:0% +crucial for applications in sampling and +hypothesis testing but let's go on so + + align:start position:0% +hypothesis testing but let's go on so + + + align:start position:0% +hypothesis testing but let's go on so +let's look at some actual numbers which + + align:start position:0% +let's look at some actual numbers which + + + align:start position:0% +let's look at some actual numbers which +I calculated if you roll a die n times + + align:start position:0% +I calculated if you roll a die n times + + + align:start position:0% +I calculated if you roll a die n times +where n is 6 6600 1,200 3,000 or 6,000 + + align:start position:0% +where n is 6 6600 1,200 3,000 or 6,000 + + + align:start position:0% +where n is 6 6600 1,200 3,000 or 6,000 +the probability that you're going to be + + align:start position:0% +the probability that you're going to be + + + align:start position:0% +the probability that you're going to be +within 10% of the expected number of + + align:start position:0% +within 10% of the expected number of + + + align:start position:0% +within 10% of the expected number of +sixes is given here so it turns out of + + align:start position:0% +sixes is given here so it turns out of + + + align:start position:0% +sixes is given here so it turns out of +course that in order to be within 10 if + + align:start position:0% +course that in order to be within 10 if + + + align:start position:0% +course that in order to be within 10 if +you're gonna roll six times the only way + + align:start position:0% +you're gonna roll six times the only way + + + align:start position:0% +you're gonna roll six times the only way +to be within 10% of the one expected six + + align:start position:0% +to be within 10% of the one expected six + + + align:start position:0% +to be within 10% of the one expected six +that you should roll is to roll exactly + + align:start position:0% +that you should roll is to roll exactly + + + align:start position:0% +that you should roll is to roll exactly +one six in six tries and the probability + + align:start position:0% +one six in six tries and the probability + + + align:start position:0% +one six in six tries and the probability +of that is about 40% point four as you + + align:start position:0% +of that is about 40% point four as you + + + align:start position:0% +of that is about 40% point four as you +can check yourself easily then it turns + + align:start position:0% +can check yourself easily then it turns + + + align:start position:0% +can check yourself easily then it turns +out that if you flip a roll + + align:start position:0% +out that if you flip a roll + + + align:start position:0% +out that if you flip a roll +60 times + + align:start position:0% +60 times + + + align:start position:0% +60 times +probability of being between 66 sorry + + align:start position:0% +probability of being between 66 sorry + + + align:start position:0% +probability of being between 66 sorry +the expected number in 60 rolls is going + + align:start position:0% +the expected number in 60 rolls is going + + + align:start position:0% +the expected number in 60 rolls is going +to be 10 so the probability of there + + align:start position:0% +to be 10 so the probability of there + + + align:start position:0% +to be 10 so the probability of there +being within 10 percent of 10 or 9 to 11 + + align:start position:0% +being within 10 percent of 10 or 9 to 11 + + + align:start position:0% +being within 10 percent of 10 or 9 to 11 +sixes is 0.26 and likewise the + + align:start position:0% +sixes is 0.26 and likewise the + + + align:start position:0% +sixes is 0.26 and likewise the +probability of there being within 10 + + align:start position:0% +probability of there being within 10 + + + align:start position:0% +probability of there being within 10 +percent of 100 which is the expected + + align:start position:0% +percent of 100 which is the expected + + + align:start position:0% +percent of 100 which is the expected +number of sixes when you roll 600 times + + align:start position:0% +number of sixes when you roll 600 times + + + align:start position:0% +number of sixes when you roll 600 times +is 0.72 and so on until finally the + + align:start position:0% +is 0.72 and so on until finally the + + + align:start position:0% +is 0.72 and so on until finally the +probability of being within 10 percent + + align:start position:0% +probability of being within 10 percent + + + align:start position:0% +probability of being within 10 percent +of a thousand which is the expected + + align:start position:0% +of a thousand which is the expected + + + align:start position:0% +of a thousand which is the expected +number when you roll 6,000 times that is + + align:start position:0% +number when you roll 6,000 times that is + + + align:start position:0% +number when you roll 6,000 times that is +between 900 and 1106 is in 6,000 rolls + + align:start position:0% +between 900 and 1106 is in 6,000 rolls + + + align:start position:0% +between 900 and 1106 is in 6,000 rolls +is point nine nine nine triple nines in + + align:start position:0% +is point nine nine nine triple nines in + + + align:start position:0% +is point nine nine nine triple nines in +fact it's a little bit bigger so it's + + align:start position:0% +fact it's a little bit bigger so it's + + + align:start position:0% +fact it's a little bit bigger so it's +really only about one chance in a + + align:start position:0% +really only about one chance in a + + + align:start position:0% +really only about one chance in a +thousand that your number of sixes won't + + align:start position:0% +thousand that your number of sixes won't + + + align:start position:0% +thousand that your number of sixes won't +fall in that interval within ten percent + + align:start position:0% +fall in that interval within ten percent + + + align:start position:0% +fall in that interval within ten percent +of the expected number well suppose I + + align:start position:0% +of the expected number well suppose I + + + align:start position:0% +of the expected number well suppose I +asked for a tighter tolerance and I'd + + align:start position:0% +asked for a tighter tolerance and I'd + + + align:start position:0% +asked for a tighter tolerance and I'd +like to know what's the probability of + + align:start position:0% +like to know what's the probability of + + + align:start position:0% +like to know what's the probability of +being within five percent well first of + + align:start position:0% +being within five percent well first of + + + align:start position:0% +being within five percent well first of +all notice of course that as the number + + align:start position:0% +all notice of course that as the number + + + align:start position:0% +all notice of course that as the number +of rolls get larger the probability of + + align:start position:0% +of rolls get larger the probability of + + + align:start position:0% +of rolls get larger the probability of +being in this given interval is of + + align:start position:0% +being in this given interval is of + + + align:start position:0% +being in this given interval is of +getting getting higher and higher which + + align:start position:0% +getting getting higher and higher which + + + align:start position:0% +getting getting higher and higher which +is what Bernoulli said and what we + + align:start position:0% +is what Bernoulli said and what we + + + align:start position:0% +is what Bernoulli said and what we +intuitively believe the more rolls the + + align:start position:0% +intuitively believe the more rolls the + + + align:start position:0% +intuitively believe the more rolls the +more likely you are to be close to what + + align:start position:0% +more likely you are to be close to what + + + align:start position:0% +more likely you are to be close to what +you expect if you tighten the tolerance + + align:start position:0% +you expect if you tighten the tolerance + + + align:start position:0% +you expect if you tighten the tolerance +of course then the probabilities wind up + + align:start position:0% +of course then the probabilities wind up + + + align:start position:0% +of course then the probabilities wind up +getting smaller that you'll do so well + + align:start position:0% +getting smaller that you'll do so well + + + align:start position:0% +getting smaller that you'll do so well +so if you want to be within 5% of the + + align:start position:0% +so if you want to be within 5% of the + + + align:start position:0% +so if you want to be within 5% of the +average in six rolls it means you still + + align:start position:0% +average in six rolls it means you still + + + align:start position:0% +average in six rolls it means you still +have to roll exactly 1/6 which means the + + align:start position:0% +have to roll exactly 1/6 which means the + + + align:start position:0% +have to roll exactly 1/6 which means the +probability is still 0.4 but if you're + + align:start position:0% +probability is still 0.4 but if you're + + + align:start position:0% +probability is still 0.4 but if you're +trying to be within 5% of the expected + + align:start position:0% +trying to be within 5% of the expected + + + align:start position:0% +trying to be within 5% of the expected +number 10 and 60 rolls meaning between 5 + + align:start position:0% +number 10 and 60 rolls meaning between 5 + + + align:start position:0% +number 10 and 60 rolls meaning between 5 +and 15 that probability is only 0.14 + + align:start position:0% +and 15 that probability is only 0.14 + + + align:start position:0% +and 15 that probability is only 0.14 +compared to the probability of 0.26 of + + align:start position:0% +compared to the probability of 0.26 of + + + align:start position:0% +compared to the probability of 0.26 of +being within 10% and if we jump down + + align:start position:0% +being within 10% and if we jump down + + + align:start position:0% +being within 10% and if we jump down +here say to 3,000 rolls + + align:start position:0% +here say to 3,000 rolls + + + align:start position:0% +here say to 3,000 rolls +the probability of being within 10% of + + align:start position:0% +the probability of being within 10% of + + + align:start position:0% +the probability of being within 10% of +500 which is the expected number in + + align:start position:0% +500 which is the expected number in + + + align:start position:0% +500 which is the expected number in +3,000 roles within 10% is 98% 9 8 but + + align:start position:0% +3,000 roles within 10% is 98% 9 8 but + + + align:start position:0% +3,000 roles within 10% is 98% 9 8 but +within being within 5% of 500 it's 0.78 + + align:start position:0% +within being within 5% of 500 it's 0.78 + + + align:start position:0% +within being within 5% of 500 it's 0.78 +or about 3 little over 3/4 so what does + + align:start position:0% +or about 3 little over 3/4 so what does + + + align:start position:0% +or about 3 little over 3/4 so what does +that tell us well it means that if you + + align:start position:0% +that tell us well it means that if you + + + align:start position:0% +that tell us well it means that if you +enrolled three thousand times and you + + align:start position:0% +enrolled three thousand times and you + + + align:start position:0% +enrolled three thousand times and you +did not get within ten percent of the + + align:start position:0% +did not get within ten percent of the + + + align:start position:0% +did not get within ten percent of the +expected number of 500 that is you did + + align:start position:0% +expected number of 500 that is you did + + + align:start position:0% +expected number of 500 that is you did +not get in the interval between 450 and + + align:start position:0% +not get in the interval between 450 and + + + align:start position:0% +not get in the interval between 450 and +550 sixes you could be 98% confident + + align:start position:0% +550 sixes you could be 98% confident + + + align:start position:0% +550 sixes you could be 98% confident +that your die is loaded it's not + + align:start position:0% +that your die is loaded it's not + + + align:start position:0% +that your die is loaded it's not +weighted 1/6 to show a 6 and similarly + + align:start position:0% +weighted 1/6 to show a 6 and similarly + + + align:start position:0% +weighted 1/6 to show a 6 and similarly +if you did not get within 425 and for + + align:start position:0% +if you did not get within 425 and for + + + align:start position:0% +if you did not get within 425 and for +525 a 6 is in 3,000 rolls you can be 78% + + align:start position:0% +525 a 6 is in 3,000 rolls you can be 78% + + + align:start position:0% +525 a 6 is in 3,000 rolls you can be 78% +sure that your die is loaded and this is + + align:start position:0% +sure that your die is loaded and this is + + + align:start position:0% +sure that your die is loaded and this is +exactly why the law of large numbers is + + align:start position:0% +exactly why the law of large numbers is + + + align:start position:0% +exactly why the law of large numbers is +so important to us because it allows us + + align:start position:0% +so important to us because it allows us + + + align:start position:0% +so important to us because it allows us +to do an experiment and then assess + + align:start position:0% +to do an experiment and then assess + + + align:start position:0% +to do an experiment and then assess +whether what we think is true is + + align:start position:0% +whether what we think is true is + + + align:start position:0% +whether what we think is true is +verified by the outcome that we got in + + align:start position:0% +verified by the outcome that we got in + + + align:start position:0% +verified by the outcome that we got in +this experiment all right let's go on to + + align:start position:0% +this experiment all right let's go on to + + + align:start position:0% +this experiment all right let's go on to +see what else Bernoulli was concerned + + align:start position:0% +see what else Bernoulli was concerned + + + align:start position:0% +see what else Bernoulli was concerned +with in his time it certainly remains to + + align:start position:0% +with in his time it certainly remains to + + + align:start position:0% +with in his time it certainly remains to +be inquired whether after the number of + + align:start position:0% +be inquired whether after the number of + + + align:start position:0% +be inquired whether after the number of +observations has been increased the + + align:start position:0% +observations has been increased the + + + align:start position:0% +observations has been increased the +probability of obtaining the true ratio + + align:start position:0% +probability of obtaining the true ratio + + + align:start position:0% +probability of obtaining the true ratio +finally exceeds any given degree of + + align:start position:0% +finally exceeds any given degree of + + + align:start position:0% +finally exceeds any given degree of +certainty or whether the problem has so + + align:start position:0% +certainty or whether the problem has so + + + align:start position:0% +certainty or whether the problem has so +to speak its own asymptotes that is + + align:start position:0% +to speak its own asymptotes that is + + + align:start position:0% +to speak its own asymptotes that is +whether some degree of certainty is + + align:start position:0% +whether some degree of certainty is + + + align:start position:0% +whether some degree of certainty is +given which one can never exceed now + + align:start position:0% +given which one can never exceed now + + + align:start position:0% +given which one can never exceed now +that's a 17th century English that maybe + + align:start position:0% +that's a 17th century English that maybe + + + align:start position:0% +that's a 17th century English that maybe +a little bit hard to parse so let's + + align:start position:0% +a little bit hard to parse so let's + + + align:start position:0% +a little bit hard to parse so let's +translate it into math language what is + + align:start position:0% +translate it into math language what is + + + align:start position:0% +translate it into math language what is +it that Bernoulli is asking so what + + align:start position:0% +it that Bernoulli is asking so what + + + align:start position:0% +it that Bernoulli is asking so what +Bernoulli means is that he wants to + + align:start position:0% +Bernoulli means is that he wants to + + + align:start position:0% +Bernoulli means is that he wants to +think about taking a random variable R + + align:start position:0% +think about taking a random variable R + + + align:start position:0% +think about taking a random variable R +with an an expectation or mean of mu and + + align:start position:0% +with an an expectation or mean of mu and + + + align:start position:0% +with an an expectation or mean of mu and +he wants to make n trial observations of + + align:start position:0% +he wants to make n trial observations of + + + align:start position:0% +he wants to make n trial observations of +R and take the average of those + + align:start position:0% +R and take the average of those + + + align:start position:0% +R and take the average of those +observations + + align:start position:0% +observations + + + align:start position:0% +observations +and see how close they are to you all + + align:start position:0% +and see how close they are to you all + + + align:start position:0% +and see how close they are to you all +right what is it what is making any + + align:start position:0% +right what is it what is making any + + + align:start position:0% +right what is it what is making any +trial observations mean well formally + + align:start position:0% +trial observations mean well formally + + + align:start position:0% +trial observations mean well formally +the way we're gonna capture it is we're + + align:start position:0% +the way we're gonna capture it is we're + + + align:start position:0% +the way we're gonna capture it is we're +gonna think of having um a bunch of + + align:start position:0% +gonna think of having um a bunch of + + + align:start position:0% +gonna think of having um a bunch of +mutually independent identically + + align:start position:0% +mutually independent identically + + + align:start position:0% +mutually independent identically +distributed random variables r1 through + + align:start position:0% +distributed random variables r1 through + + + align:start position:0% +distributed random variables r1 through +RN this phrase identically independent + + align:start position:0% +RN this phrase identically independent + + + align:start position:0% +RN this phrase identically independent +identically distributed comes up so + + align:start position:0% +identically distributed comes up so + + + align:start position:0% +identically distributed comes up so +often that there's a standard + + align:start position:0% +often that there's a standard + + + align:start position:0% +often that there's a standard +abbreviation iid random variables so + + align:start position:0% +abbreviation iid random variables so + + + align:start position:0% +abbreviation iid random variables so +we're going to have n of them and think + + align:start position:0% +we're going to have n of them and think + + + align:start position:0% +we're going to have n of them and think +of those as being the n observations + + align:start position:0% +of those as being the n observations + + + align:start position:0% +of those as being the n observations +that we make of a given random variable + + align:start position:0% +that we make of a given random variable + + + align:start position:0% +that we make of a given random variable +on so r1 through RN each have exactly + + align:start position:0% +on so r1 through RN each have exactly + + + align:start position:0% +on so r1 through RN each have exactly +the same distribution is our and they're + + align:start position:0% +the same distribution is our and they're + + + align:start position:0% +the same distribution is our and they're +mutually independent and again since + + align:start position:0% +mutually independent and again since + + + align:start position:0% +mutually independent and again since +they're they have identical + + align:start position:0% +they're they have identical + + + align:start position:0% +they're they have identical +distributions they all have the same + + align:start position:0% +distributions they all have the same + + + align:start position:0% +distributions they all have the same +mean mu as the random variable R that we + + align:start position:0% +mean mu as the random variable R that we + + + align:start position:0% +mean mu as the random variable R that we +were trying to investigate so we model n + + align:start position:0% +were trying to investigate so we model n + + + align:start position:0% +were trying to investigate so we model n +independent trials repeated trials by + + align:start position:0% +independent trials repeated trials by + + + align:start position:0% +independent trials repeated trials by +saying that we have n random variables + + align:start position:0% +saying that we have n random variables + + + align:start position:0% +saying that we have n random variables +that are iid okay now what Bernoulli is + + align:start position:0% +that are iid okay now what Bernoulli is + + + align:start position:0% +that are iid okay now what Bernoulli is +proposing is that you take the average + + align:start position:0% +proposing is that you take the average + + + align:start position:0% +proposing is that you take the average +of those n random variables so you take + + align:start position:0% +of those n random variables so you take + + + align:start position:0% +of those n random variables so you take +R 1 through some of our 1 or 2 up + + align:start position:0% +R 1 through some of our 1 or 2 up + + + align:start position:0% +R 1 through some of our 1 or 2 up +through R and then divide by n that's + + align:start position:0% +through R and then divide by n that's + + + align:start position:0% +through R and then divide by n that's +the average value call that a sub n the + + align:start position:0% +the average value call that a sub n the + + + align:start position:0% +the average value call that a sub n the +average of the n observations of the n + + align:start position:0% +average of the n observations of the n + + + align:start position:0% +average of the n observations of the n +roll's + + align:start position:0% +roll's + + + align:start position:0% +roll's +and Bernoulli's question is is this + + align:start position:0% +and Bernoulli's question is is this + + + align:start position:0% +and Bernoulli's question is is this +average probably close to the mean mu if + + align:start position:0% +average probably close to the mean mu if + + + align:start position:0% +average probably close to the mean mu if +n is big what exactly does that mean + + align:start position:0% +n is big what exactly does that mean + + + align:start position:0% +n is big what exactly does that mean +probably close to MU means that the + + align:start position:0% +probably close to MU means that the + + + align:start position:0% +probably close to MU means that the +probability that the distance between + + align:start position:0% +probability that the distance between + + + align:start position:0% +probability that the distance between +the average and mu is less than or equal + + align:start position:0% +the average and mu is less than or equal + + + align:start position:0% +the average and mu is less than or equal +to Delta is what so Delta is talking + + align:start position:0% +to Delta is what so Delta is talking + + + align:start position:0% +to Delta is what so Delta is talking +about how close you are + + align:start position:0% +about how close you are + + + align:start position:0% +about how close you are +don't they as a parameter we expect it's + + align:start position:0% +don't they as a parameter we expect it's + + + align:start position:0% +don't they as a parameter we expect it's +got to be positive we're asking think of + + align:start position:0% +got to be positive we're asking think of + + + align:start position:0% +got to be positive we're asking think of +whatever close means to you does it mean + + align:start position:0% +whatever close means to you does it mean + + + align:start position:0% +whatever close means to you does it mean +0.1 does it mean point o 1 what amount + + align:start position:0% +0.1 does it mean point o 1 what amount + + + align:start position:0% +0.1 does it mean point o 1 what amount +would persuade you that um that the + + align:start position:0% +would persuade you that um that the + + + align:start position:0% +would persuade you that um that the +average was close to what it ought to be + + align:start position:0% +average was close to what it ought to be + + + align:start position:0% +average was close to what it ought to be +and we ask then whether the distance + + align:start position:0% +and we ask then whether the distance + + + align:start position:0% +and we ask then whether the distance +between the average and the mean is + + align:start position:0% +between the average and the mean is + + + align:start position:0% +between the average and the mean is +close less than or equal to Delta and + + align:start position:0% +close less than or equal to Delta and + + + align:start position:0% +close less than or equal to Delta and +Bernoulli wants to know what is the + + align:start position:0% +Bernoulli wants to know what is the + + + align:start position:0% +Bernoulli wants to know what is the +probability of that + + align:start position:0% + + + + align:start position:0% + +and what he goes on to say is therefore + + align:start position:0% +and what he goes on to say is therefore + + + align:start position:0% +and what he goes on to say is therefore +this is the problem which I now set + + align:start position:0% +this is the problem which I now set + + + align:start position:0% +this is the problem which I now set +forth and make known after I have + + align:start position:0% +forth and make known after I have + + + align:start position:0% +forth and make known after I have +pondered it pondered over it for 20 + + align:start position:0% +pondered it pondered over it for 20 + + + align:start position:0% +pondered it pondered over it for 20 +years both its novelty and its very + + align:start position:0% +years both its novelty and its very + + + align:start position:0% +years both its novelty and its very +great usefulness coupled with its great + + align:start position:0% +great usefulness coupled with its great + + + align:start position:0% +great usefulness coupled with its great +difficulty can exceed in weight and + + align:start position:0% +difficulty can exceed in weight and + + + align:start position:0% +difficulty can exceed in weight and +value all the remaining chapters of this + + align:start position:0% +value all the remaining chapters of this + + + align:start position:0% +value all the remaining chapters of this +thesis now Bernoulli was right on about + + align:start position:0% +thesis now Bernoulli was right on about + + + align:start position:0% +thesis now Bernoulli was right on about +the usefulness of this result at least + + align:start position:0% +the usefulness of this result at least + + + align:start position:0% +the usefulness of this result at least +in its quantitative form and at the time + + align:start position:0% +in its quantitative form and at the time + + + align:start position:0% +in its quantitative form and at the time +it was really pretty difficult for him + + align:start position:0% +it was really pretty difficult for him + + + align:start position:0% +it was really pretty difficult for him +it took him like 200 pages to complete + + align:start position:0% +it took him like 200 pages to complete + + + align:start position:0% +it took him like 200 pages to complete +his proof in ARS konjac tandy nowadays + + align:start position:0% +his proof in ARS konjac tandy nowadays + + + align:start position:0% +his proof in ARS konjac tandy nowadays +we are going to do it in about a lecture + + align:start position:0% +we are going to do it in about a lecture + + + align:start position:0% +we are going to do it in about a lecture +worth of material and you'll be seeing + + align:start position:0% +worth of material and you'll be seeing + + + align:start position:0% +worth of material and you'll be seeing +that in some subsequent video segments + + align:start position:0% +that in some subsequent video segments + + + align:start position:0% +that in some subsequent video segments +so that's what happens with 300 years + + align:start position:0% +so that's what happens with 300 years + + + align:start position:0% +so that's what happens with 300 years +two or three hundred and fifty years to + + align:start position:0% +two or three hundred and fifty years to + + + align:start position:0% +two or three hundred and fifty years to +tune up a result what took 200 pages + + align:start position:0% +tune up a result what took 200 pages + + + align:start position:0% +tune up a result what took 200 pages +then now takes 10 or less pages in fact + + align:start position:0% +then now takes 10 or less pages in fact + + + align:start position:0% +then now takes 10 or less pages in fact +if it was really concise it could be + + align:start position:0% +if it was really concise it could be + + + align:start position:0% +if it was really concise it could be +done in a few in three pages alright so + + align:start position:0% +done in a few in three pages alright so + + + align:start position:0% +done in a few in three pages alright so +again coming back to Bernoulli's + + align:start position:0% +again coming back to Bernoulli's + + + align:start position:0% +again coming back to Bernoulli's +question Bernoulli's question is what is + + align:start position:0% +question Bernoulli's question is what is + + + align:start position:0% +question Bernoulli's question is what is +the probability that the average that + + align:start position:0% +the probability that the average that + + + align:start position:0% +the probability that the average that +the distance between the average and the + + align:start position:0% +the distance between the average and the + + + align:start position:0% +the distance between the average and the +mean is less than or equal to Delta as + + align:start position:0% +mean is less than or equal to Delta as + + + align:start position:0% +mean is less than or equal to Delta as +you take more and more tries as n goes + + align:start position:0% +you take more and more tries as n goes + + + align:start position:0% +you take more and more tries as n goes +to infinity and Bernoulli's answer to + + align:start position:0% +to infinity and Bernoulli's answer to + + + align:start position:0% +to infinity and Bernoulli's answer to +the question is that the probability is + + align:start position:0% +the question is that the probability is + + + align:start position:0% +the question is that the probability is +1 that is if you want to be have a + + align:start position:0% +1 that is if you want to be have a + + + align:start position:0% +1 that is if you want to be have a +certain degree of certainty of being + + align:start position:0% +certain degree of certainty of being + + + align:start position:0% +certain degree of certainty of being +close to the mean within though if you + + align:start position:0% +close to the mean within though if you + + + align:start position:0% +close to the mean within though if you +take enough trials you can be as certain + + align:start position:0% +take enough trials you can be as certain + + + align:start position:0% +take enough trials you can be as certain +as you want that you'll be as close as + + align:start position:0% +as you want that you'll be as close as + + + align:start position:0% +as you want that you'll be as close as +you want and that is called the weak law + + align:start position:0% +you want and that is called the weak law + + + align:start position:0% +you want and that is called the weak law +of large numbers and it's one of the + + align:start position:0% +of large numbers and it's one of the + + + align:start position:0% +of large numbers and it's one of the +basic transcendent rules and theorems of + + align:start position:0% +basic transcendent rules and theorems of + + + align:start position:0% +basic transcendent rules and theorems of +probability theory it's usually stated + + align:start position:0% +probability theory it's usually stated + + + align:start position:0% +probability theory it's usually stated +in the other way as that the limit of + + align:start position:0% +in the other way as that the limit of + + + align:start position:0% +in the other way as that the limit of +the probability that the average is a + + align:start position:0% +the probability that the average is a + + + align:start position:0% +the probability that the average is a +distance away from the mean Delta is 0 + + align:start position:0% +distance away from the mean Delta is 0 + + + align:start position:0% +distance away from the mean Delta is 0 +it's the probability that it's it's + + align:start position:0% +it's the probability that it's it's + + + align:start position:0% +it's the probability that it's it's +extremely unlikely it can be as unlikely + + align:start position:0% +extremely unlikely it can be as unlikely + + + align:start position:0% +extremely unlikely it can be as unlikely +as you want to make it that it's more + + align:start position:0% +as you want to make it that it's more + + + align:start position:0% +as you want to make it that it's more +than any given tolerance from the mean + + align:start position:0% +than any given tolerance from the mean + + + align:start position:0% +than any given tolerance from the mean +as if you take a large enough number of + + align:start position:0% +as if you take a large enough number of + + + align:start position:0% +as if you take a large enough number of +trials now in this form it's not yet + + align:start position:0% +trials now in this form it's not yet + + + align:start position:0% +trials now in this form it's not yet +really use + + align:start position:0% +really use + + + align:start position:0% +really use +this is a romantic qualitative limit + + align:start position:0% +this is a romantic qualitative limit + + + align:start position:0% +this is a romantic qualitative limit +limiting result and to really use it you + + align:start position:0% +limiting result and to really use it you + + + align:start position:0% +limiting result and to really use it you +need to know something rather about the + + align:start position:0% +need to know something rather about the + + + align:start position:0% +need to know something rather about the +rate at which it approaches the limit + + align:start position:0% +rate at which it approaches the limit + + + align:start position:0% +rate at which it approaches the limit +which is what we're going to be seeing + + align:start position:0% +which is what we're going to be seeing + + + align:start position:0% +which is what we're going to be seeing +in a subsequent video and in fact the + + align:start position:0% +in a subsequent video and in fact the + + + align:start position:0% +in a subsequent video and in fact the +proof of this is going to follow easily + + align:start position:0% +proof of this is going to follow easily + + + align:start position:0% +proof of this is going to follow easily +from the chebyshev inequality bound and + + align:start position:0% +from the chebyshev inequality bound and + + + align:start position:0% +from the chebyshev inequality bound and +variance properties when we go about + + align:start position:0% +variance properties when we go about + + + align:start position:0% +variance properties when we go about +trying to get the quantitative version + + align:start position:0% +trying to get the quantitative version + + + align:start position:0% +trying to get the quantitative version +that explains the rate at which the + + align:start position:0% +that explains the rate at which the + + + align:start position:0% +that explains the rate at which the +limit is approached \ No newline at end of file diff --git a/0LqS5QtpSVE.txt b/0LqS5QtpSVE.txt new file mode 100644 index 0000000000000000000000000000000000000000..5b755a08ccd82c8e25ce70b8c66724c8af86ff26 --- /dev/null +++ b/0LqS5QtpSVE.txt @@ -0,0 +1,2155 @@ +align:start position:0% + +now let's turn our attention to control + + align:start position:0% +now let's turn our attention to control + + + align:start position:0% +now let's turn our attention to control +hazards illustrated by the code fragment + + align:start position:0% +hazards illustrated by the code fragment + + + align:start position:0% +hazards illustrated by the code fragment +shown here which instruction should be + + align:start position:0% +shown here which instruction should be + + + align:start position:0% +shown here which instruction should be +executed after the B&E if the value in + + align:start position:0% +executed after the B&E if the value in + + + align:start position:0% +executed after the B&E if the value in +r3 is nonzero and it C should be + + align:start position:0% +r3 is nonzero and it C should be + + + align:start position:0% +r3 is nonzero and it C should be +executed if the value in r3 is 0 the + + align:start position:0% +executed if the value in r3 is 0 the + + + align:start position:0% +executed if the value in r3 is 0 the +next instruction should be sub if the + + align:start position:0% +next instruction should be sub if the + + + align:start position:0% +next instruction should be sub if the +current instruction is an explicit + + align:start position:0% +current instruction is an explicit + + + align:start position:0% +current instruction is an explicit +transfer of control in other words jumps + + align:start position:0% +transfer of control in other words jumps + + + align:start position:0% +transfer of control in other words jumps +or branches the choice of the next + + align:start position:0% +or branches the choice of the next + + + align:start position:0% +or branches the choice of the next +instruction depends on the execution of + + align:start position:0% +instruction depends on the execution of + + + align:start position:0% +instruction depends on the execution of +the current instruction what are the + + align:start position:0% +the current instruction what are the + + + align:start position:0% +the current instruction what are the +implications of this dependency on our + + align:start position:0% +implications of this dependency on our + + + align:start position:0% +implications of this dependency on our +execution pipeline how does the + + align:start position:0% +execution pipeline how does the + + + align:start position:0% +execution pipeline how does the +unpiloted determine the next instruction + + align:start position:0% +unpiloted determine the next instruction + + + align:start position:0% +unpiloted determine the next instruction +for branches BEQ or B&E the value to be + + align:start position:0% +for branches BEQ or B&E the value to be + + + align:start position:0% +for branches BEQ or B&E the value to be +loaded into the program counter depends + + align:start position:0% +loaded into the program counter depends + + + align:start position:0% +loaded into the program counter depends +on 1 the opcode in other words whether + + align:start position:0% +on 1 the opcode in other words whether + + + align:start position:0% +on 1 the opcode in other words whether +the instruction is a BEQ or be any to + + align:start position:0% +the instruction is a BEQ or be any to + + + align:start position:0% +the instruction is a BEQ or be any to +the current value of the program counter + + align:start position:0% +the current value of the program counter + + + align:start position:0% +the current value of the program counter +since that's used in the offset + + align:start position:0% +since that's used in the offset + + + align:start position:0% +since that's used in the offset +calculation and 3 the values stored in + + align:start position:0% +calculation and 3 the values stored in + + + align:start position:0% +calculation and 3 the values stored in +the register specified by the RA field + + align:start position:0% +the register specified by the RA field + + + align:start position:0% +the register specified by the RA field +of the instruction since that's the + + align:start position:0% +of the instruction since that's the + + + align:start position:0% +of the instruction since that's the +value tested by the branch for jump + + align:start position:0% +value tested by the branch for jump + + + align:start position:0% +value tested by the branch for jump +instructions the next value of the + + align:start position:0% +instructions the next value of the + + + align:start position:0% +instructions the next value of the +program counter depends once again on + + align:start position:0% +program counter depends once again on + + + align:start position:0% +program counter depends once again on +the opcode field and the value of the RA + + align:start position:0% +the opcode field and the value of the RA + + + align:start position:0% +the opcode field and the value of the RA +register for all other instructions the + + align:start position:0% +register for all other instructions the + + + align:start position:0% +register for all other instructions the +next PC value depends only on the opcode + + align:start position:0% +next PC value depends only on the opcode + + + align:start position:0% +next PC value depends only on the opcode +of the instruction and the value PC plus + + align:start position:0% +of the instruction and the value PC plus + + + align:start position:0% +of the instruction and the value PC plus +4 exceptions also change the program + + align:start position:0% +4 exceptions also change the program + + + align:start position:0% +4 exceptions also change the program +counter we'll deal with them later in + + align:start position:0% +counter we'll deal with them later in + + + align:start position:0% +counter we'll deal with them later in +the lecture the control hazard is + + align:start position:0% +the lecture the control hazard is + + + align:start position:0% +the lecture the control hazard is +triggered by jump and branches since + + align:start position:0% +triggered by jump and branches since + + + align:start position:0% +triggered by jump and branches since +their execution depends on the value in + + align:start position:0% +their execution depends on the value in + + + align:start position:0% +their execution depends on the value in +the RA register in other words they need + + align:start position:0% +the RA register in other words they need + + + align:start position:0% +the RA register in other words they need +to read from the register file which + + align:start position:0% +to read from the register file which + + + align:start position:0% +to read from the register file which +happens in the RF stage our bypass + + align:start position:0% +happens in the RF stage our bypass + + + align:start position:0% +happens in the RF stage our bypass +mechanisms ensure that we'll use the + + align:start position:0% +mechanisms ensure that we'll use the + + + align:start position:0% +mechanisms ensure that we'll use the +correct value for the RA register even + + align:start position:0% +correct value for the RA register even + + + align:start position:0% +correct value for the RA register even +if it's not yet written into the + + align:start position:0% +if it's not yet written into the + + + align:start position:0% +if it's not yet written into the +register file what we're concerned about + + align:start position:0% +register file what we're concerned about + + + align:start position:0% +register file what we're concerned about +here + + align:start position:0% +here + + + align:start position:0% +here +is that the address of the instruction + + align:start position:0% +is that the address of the instruction + + + align:start position:0% +is that the address of the instruction +following the jumper branch will be + + align:start position:0% +following the jumper branch will be + + + align:start position:0% +following the jumper branch will be +loaded into the program counter at the + + align:start position:0% +loaded into the program counter at the + + + align:start position:0% +loaded into the program counter at the +end of the cycle when the jump or branch + + align:start position:0% +end of the cycle when the jump or branch + + + align:start position:0% +end of the cycle when the jump or branch +is in the RF stage but what should the I + + align:start position:0% +is in the RF stage but what should the I + + + align:start position:0% +is in the RF stage but what should the I +have stage be doing while all this is + + align:start position:0% +have stage be doing while all this is + + + align:start position:0% +have stage be doing while all this is +going on in the RF stage the answer is + + align:start position:0% +going on in the RF stage the answer is + + + align:start position:0% +going on in the RF stage the answer is +that in the case of jumps + + align:start position:0% +that in the case of jumps + + + align:start position:0% +that in the case of jumps +taken branches we don't know what the + + align:start position:0% +taken branches we don't know what the + + + align:start position:0% +taken branches we don't know what the +i/o state should be doing until those + + align:start position:0% +i/o state should be doing until those + + + align:start position:0% +i/o state should be doing until those +instructions are able to access the + + align:start position:0% +instructions are able to access the + + + align:start position:0% +instructions are able to access the +value of the RA register in the RF stage + + align:start position:0% +value of the RA register in the RF stage + + + align:start position:0% +value of the RA register in the RF stage +one solution is to stall the if' stage + + align:start position:0% +one solution is to stall the if' stage + + + align:start position:0% +one solution is to stall the if' stage +until the RF stage can compute the + + align:start position:0% +until the RF stage can compute the + + + align:start position:0% +until the RF stage can compute the +necessary result this was the first of + + align:start position:0% +necessary result this was the first of + + + align:start position:0% +necessary result this was the first of +our general strategies for dealing with + + align:start position:0% +our general strategies for dealing with + + + align:start position:0% +our general strategies for dealing with +hazards how would this work + + align:start position:0% +hazards how would this work + + + align:start position:0% +hazards how would this work +if the opcode and the RF stage is jump + + align:start position:0% +if the opcode and the RF stage is jump + + + align:start position:0% +if the opcode and the RF stage is jump +the EQ or be any stall the if' stage for + + align:start position:0% +the EQ or be any stall the if' stage for + + + align:start position:0% +the EQ or be any stall the if' stage for +one cycle in the example code shown here + + align:start position:0% +one cycle in the example code shown here + + + align:start position:0% +one cycle in the example code shown here +assume that the value in r3 is non zero + + align:start position:0% +assume that the value in r3 is non zero + + + align:start position:0% +assume that the value in r3 is non zero +when the BNE is executed in other words + + align:start position:0% +when the BNE is executed in other words + + + align:start position:0% +when the BNE is executed in other words +that the instruction following the B&E + + align:start position:0% +that the instruction following the B&E + + + align:start position:0% +that the instruction following the B&E +should be the ad c-- at the top of the + + align:start position:0% +should be the ad c-- at the top of the + + + align:start position:0% +should be the ad c-- at the top of the +loop the pipeline diagram shows the + + align:start position:0% +loop the pipeline diagram shows the + + + align:start position:0% +loop the pipeline diagram shows the +effect we're trying to achieve a no op + + align:start position:0% +effect we're trying to achieve a no op + + + align:start position:0% +effect we're trying to achieve a no op +is inserted into the pipeline and cycles + + align:start position:0% +is inserted into the pipeline and cycles + + + align:start position:0% +is inserted into the pipeline and cycles +four and eight then an execution resumes + + align:start position:0% +four and eight then an execution resumes + + + align:start position:0% +four and eight then an execution resumes +in the next cycle after the RF stage + + align:start position:0% +in the next cycle after the RF stage + + + align:start position:0% +in the next cycle after the RF stage +determines what instruction comes next + + align:start position:0% +determines what instruction comes next + + + align:start position:0% +determines what instruction comes next +note by the way that we're relying on + + align:start position:0% +note by the way that we're relying on + + + align:start position:0% +note by the way that we're relying on +our bypass logic to deliver the correct + + align:start position:0% +our bypass logic to deliver the correct + + + align:start position:0% +our bypass logic to deliver the correct +value for r3 from the mem stage since + + align:start position:0% +value for r3 from the mem stage since + + + align:start position:0% +value for r3 from the mem stage since +the adds the instruction that wrote into + + align:start position:0% +the adds the instruction that wrote into + + + align:start position:0% +the adds the instruction that wrote into +r3 is still in the pipeline in other + + align:start position:0% +r3 is still in the pipeline in other + + + align:start position:0% +r3 is still in the pipeline in other +words we have a data hazard to deal with + + align:start position:0% +words we have a data hazard to deal with + + + align:start position:0% +words we have a data hazard to deal with +- looking at say the right back stage in + + align:start position:0% +- looking at say the right back stage in + + + align:start position:0% +- looking at say the right back stage in +the pipeline diagram we see that it + + align:start position:0% +the pipeline diagram we see that it + + + align:start position:0% +the pipeline diagram we see that it +takes four cycles to execute one + + align:start position:0% +takes four cycles to execute one + + + align:start position:0% +takes four cycles to execute one +iteration of our three instruction loop + + align:start position:0% +iteration of our three instruction loop + + + align:start position:0% +iteration of our three instruction loop +so the effective CPI is 4/3 an increase + + align:start position:0% +so the effective CPI is 4/3 an increase + + + align:start position:0% +so the effective CPI is 4/3 an increase +of 33 percent using stall to deal with + + align:start position:0% +of 33 percent using stall to deal with + + + align:start position:0% +of 33 percent using stall to deal with +control hazards has had an impact on the + + align:start position:0% +control hazards has had an impact on the + + + align:start position:0% +control hazards has had an impact on the +instruction throughput of our execution + + align:start position:0% +instruction throughput of our execution + + + align:start position:0% +instruction throughput of our execution +pipeline we've already seen the logic + + align:start position:0% +pipeline we've already seen the logic + + + align:start position:0% +pipeline we've already seen the logic +needed to introduce no ops into the + + align:start position:0% +needed to introduce no ops into the + + + align:start position:0% +needed to introduce no ops into the +pipeline in this case we add a MUX to + + align:start position:0% +pipeline in this case we add a MUX to + + + align:start position:0% +pipeline in this case we add a MUX to +the instruction path in the if' stage + + align:start position:0% +the instruction path in the if' stage + + + align:start position:0% +the instruction path in the if' stage +controlled by the IR source if' signal + + align:start position:0% +controlled by the IR source if' signal + + + align:start position:0% +controlled by the IR source if' signal +we use the superscript on the control + + align:start position:0% +we use the superscript on the control + + + align:start position:0% +we use the superscript on the control +signals to indicate which pipeline state + + align:start position:0% +signals to indicate which pipeline state + + + align:start position:0% +signals to indicate which pipeline state +holds the logic if they control if the + + align:start position:0% +holds the logic if they control if the + + + align:start position:0% +holds the logic if they control if the +opcode in the RF stage has jumped BEQ or + + align:start position:0% +opcode in the RF stage has jumped BEQ or + + + align:start position:0% +opcode in the RF stage has jumped BEQ or +B&E we set IR source if' to one which + + align:start position:0% +B&E we set IR source if' to one which + + + align:start position:0% +B&E we set IR source if' to one which +causes a no op to replace the + + align:start position:0% +causes a no op to replace the + + + align:start position:0% +causes a no op to replace the +instruction that was being read from + + align:start position:0% +instruction that was being read from + + + align:start position:0% +instruction that was being read from +main memory and of course we'll be + + align:start position:0% +main memory and of course we'll be + + + align:start position:0% +main memory and of course we'll be +setting the PC + + align:start position:0% +setting the PC + + + align:start position:0% +setting the PC +roll signals to select the correct next + + align:start position:0% +roll signals to select the correct next + + + align:start position:0% +roll signals to select the correct next +PC value so the i/o stage will fetch the + + align:start position:0% +PC value so the i/o stage will fetch the + + + align:start position:0% +PC value so the i/o stage will fetch the +desired follow-on instruction in the + + align:start position:0% +desired follow-on instruction in the + + + align:start position:0% +desired follow-on instruction in the +next cycle if we replace an instruction + + align:start position:0% +next cycle if we replace an instruction + + + align:start position:0% +next cycle if we replace an instruction +with a no op we say we annulled the + + align:start position:0% +with a no op we say we annulled the + + + align:start position:0% +with a no op we say we annulled the +instruction the branch instructions in + + align:start position:0% +instruction the branch instructions in + + + align:start position:0% +instruction the branch instructions in +the beta is a make their branch decision + + align:start position:0% +the beta is a make their branch decision + + + align:start position:0% +the beta is a make their branch decision +in the RF stage since they only need the + + align:start position:0% +in the RF stage since they only need the + + + align:start position:0% +in the RF stage since they only need the +value in register RA but suppose the ISA + + align:start position:0% +value in register RA but suppose the ISA + + + align:start position:0% +value in register RA but suppose the ISA +had a branch where the branch decision + + align:start position:0% +had a branch where the branch decision + + + align:start position:0% +had a branch where the branch decision +was made in the ALU stage when the + + align:start position:0% +was made in the ALU stage when the + + + align:start position:0% +was made in the ALU stage when the +branch decision is made in the ALU stage + + align:start position:0% +branch decision is made in the ALU stage + + + align:start position:0% +branch decision is made in the ALU stage +we need to introduce to no ops into the + + align:start position:0% +we need to introduce to no ops into the + + + align:start position:0% +we need to introduce to no ops into the +pipeline replacing the now unwanted + + align:start position:0% +pipeline replacing the now unwanted + + + align:start position:0% +pipeline replacing the now unwanted +instructions in the RF and I of stages + + align:start position:0% +instructions in the RF and I of stages + + + align:start position:0% +instructions in the RF and I of stages +this would increase the effective CPI + + align:start position:0% +this would increase the effective CPI + + + align:start position:0% +this would increase the effective CPI +even further but the trade-off is that + + align:start position:0% +even further but the trade-off is that + + + align:start position:0% +even further but the trade-off is that +the more complex branches may reduce the + + align:start position:0% +the more complex branches may reduce the + + + align:start position:0% +the more complex branches may reduce the +number of instructions in the program if + + align:start position:0% +number of instructions in the program if + + + align:start position:0% +number of instructions in the program if +we annul instructions in all the earlier + + align:start position:0% +we annul instructions in all the earlier + + + align:start position:0% +we annul instructions in all the earlier +pipeline stages this is called flushing + + align:start position:0% +pipeline stages this is called flushing + + + align:start position:0% +pipeline stages this is called flushing +the pipeline since flushing the pipeline + + align:start position:0% +the pipeline since flushing the pipeline + + + align:start position:0% +the pipeline since flushing the pipeline +has a big impact on the effective CPI we + + align:start position:0% +has a big impact on the effective CPI we + + + align:start position:0% +has a big impact on the effective CPI we +do it when it's the only way to ensure + + align:start position:0% +do it when it's the only way to ensure + + + align:start position:0% +do it when it's the only way to ensure +the correct behavior of the execution + + align:start position:0% +the correct behavior of the execution + + + align:start position:0% +the correct behavior of the execution +pipeline we can be smarter about when we + + align:start position:0% +pipeline we can be smarter about when we + + + align:start position:0% +pipeline we can be smarter about when we +choose to flush the pipeline when + + align:start position:0% +choose to flush the pipeline when + + + align:start position:0% +choose to flush the pipeline when +executing branches the branch is + + align:start position:0% +executing branches the branch is + + + align:start position:0% +executing branches the branch is +not-taken it turns out that the pipeline + + align:start position:0% +not-taken it turns out that the pipeline + + + align:start position:0% +not-taken it turns out that the pipeline +has been doing the right thing by + + align:start position:0% +has been doing the right thing by + + + align:start position:0% +has been doing the right thing by +fetching the instruction following the + + align:start position:0% +fetching the instruction following the + + + align:start position:0% +fetching the instruction following the +branch starting execution of an + + align:start position:0% +branch starting execution of an + + + align:start position:0% +branch starting execution of an +instruction even when we're unsure + + align:start position:0% +instruction even when we're unsure + + + align:start position:0% +instruction even when we're unsure +whether we really want it executed is + + align:start position:0% +whether we really want it executed is + + + align:start position:0% +whether we really want it executed is +called speculation speculation is okay + + align:start position:0% +called speculation speculation is okay + + + align:start position:0% +called speculation speculation is okay +if we're able to annul the instruction + + align:start position:0% +if we're able to annul the instruction + + + align:start position:0% +if we're able to annul the instruction +before it has an effect on the CPU State + + align:start position:0% +before it has an effect on the CPU State + + + align:start position:0% +before it has an effect on the CPU State +for example by writing into the register + + align:start position:0% +for example by writing into the register + + + align:start position:0% +for example by writing into the register +file or main memory since these state + + align:start position:0% +file or main memory since these state + + + align:start position:0% +file or main memory since these state +changes called side-effects happen in + + align:start position:0% +changes called side-effects happen in + + + align:start position:0% +changes called side-effects happen in +the later pipeline stages an instruction + + align:start position:0% +the later pipeline stages an instruction + + + align:start position:0% +the later pipeline stages an instruction +can progress through the if' RF and ALU + + align:start position:0% +can progress through the if' RF and ALU + + + align:start position:0% +can progress through the if' RF and ALU +stages before we have to make a final + + align:start position:0% +stages before we have to make a final + + + align:start position:0% +stages before we have to make a final +decision about whether it should be + + align:start position:0% +decision about whether it should be + + + align:start position:0% +decision about whether it should be +annulled + + align:start position:0% +annulled + + + align:start position:0% +annulled +how does speculation help with control + + align:start position:0% +how does speculation help with control + + + align:start position:0% +how does speculation help with control +hazards guessing that the next value of + + align:start position:0% +hazards guessing that the next value of + + + align:start position:0% +hazards guessing that the next value of +the program counter is PC plus 4 is + + align:start position:0% +the program counter is PC plus 4 is + + + align:start position:0% +the program counter is PC plus 4 is +correct for all but jumps and taken + + align:start position:0% +correct for all but jumps and taken + + + align:start position:0% +correct for all but jumps and taken +branches here's our example again but + + align:start position:0% +branches here's our example again but + + + align:start position:0% +branches here's our example again but +this time let's assume that the BND is + + align:start position:0% +this time let's assume that the BND is + + + align:start position:0% +this time let's assume that the BND is +not taken in other words that the value + + align:start position:0% +not taken in other words that the value + + + align:start position:0% +not taken in other words that the value +in + + align:start position:0% +in + + + align:start position:0% +in +three is zero the sub instruction enters + + align:start position:0% +three is zero the sub instruction enters + + + align:start position:0% +three is zero the sub instruction enters +the pipeline at the start of cycle four + + align:start position:0% +the pipeline at the start of cycle four + + + align:start position:0% +the pipeline at the start of cycle four +at the end of cycle four we know whether + + align:start position:0% +at the end of cycle four we know whether + + + align:start position:0% +at the end of cycle four we know whether +or not doin all the sub if the branch is + + align:start position:0% +or not doin all the sub if the branch is + + + align:start position:0% +or not doin all the sub if the branch is +not-taken + + align:start position:0% +not-taken + + + align:start position:0% +not-taken +we want to execute the sub instruction + + align:start position:0% +we want to execute the sub instruction + + + align:start position:0% +we want to execute the sub instruction +so we just let it continue down the + + align:start position:0% +so we just let it continue down the + + + align:start position:0% +so we just let it continue down the +pipeline in other words instead of + + align:start position:0% +pipeline in other words instead of + + + align:start position:0% +pipeline in other words instead of +always annulling the instruction + + align:start position:0% +always annulling the instruction + + + align:start position:0% +always annulling the instruction +following the branch we only annul it if + + align:start position:0% +following the branch we only annul it if + + + align:start position:0% +following the branch we only annul it if +the branch was taken if the branch is + + align:start position:0% +the branch was taken if the branch is + + + align:start position:0% +the branch was taken if the branch is +not-taken + + align:start position:0% +not-taken + + + align:start position:0% +not-taken +the pipeline is speculated correctly and + + align:start position:0% +the pipeline is speculated correctly and + + + align:start position:0% +the pipeline is speculated correctly and +no instructions need to be annulled + + align:start position:0% +no instructions need to be annulled + + + align:start position:0% +no instructions need to be annulled +however if the BND is taken the sub is + + align:start position:0% +however if the BND is taken the sub is + + + align:start position:0% +however if the BND is taken the sub is +annulled at the end of cycle four and a + + align:start position:0% +annulled at the end of cycle four and a + + + align:start position:0% +annulled at the end of cycle four and a +no op is executed in cycle five so we + + align:start position:0% +no op is executed in cycle five so we + + + align:start position:0% +no op is executed in cycle five so we +only introduce a bubble in the pipeline + + align:start position:0% +only introduce a bubble in the pipeline + + + align:start position:0% +only introduce a bubble in the pipeline +when there's a taken branch fewer + + align:start position:0% +when there's a taken branch fewer + + + align:start position:0% +when there's a taken branch fewer +bubbles will decrease the impact of + + align:start position:0% +bubbles will decrease the impact of + + + align:start position:0% +bubbles will decrease the impact of +annulment on the effective CPI we'll be + + align:start position:0% +annulment on the effective CPI we'll be + + + align:start position:0% +annulment on the effective CPI we'll be +using the same data path circuitry as + + align:start position:0% +using the same data path circuitry as + + + align:start position:0% +using the same data path circuitry as +before we'll just be a bit more clever + + align:start position:0% +before we'll just be a bit more clever + + + align:start position:0% +before we'll just be a bit more clever +about when the value of the IRS or SIF + + align:start position:0% +about when the value of the IRS or SIF + + + align:start position:0% +about when the value of the IRS or SIF +control signal is set to one instead of + + align:start position:0% +control signal is set to one instead of + + + align:start position:0% +control signal is set to one instead of +setting it to one for all branches we + + align:start position:0% +setting it to one for all branches we + + + align:start position:0% +setting it to one for all branches we +only set it to one when the branch is + + align:start position:0% +only set it to one when the branch is + + + align:start position:0% +only set it to one when the branch is +taken our naive strategy of always + + align:start position:0% +taken our naive strategy of always + + + align:start position:0% +taken our naive strategy of always +speculating that the next instruction + + align:start position:0% +speculating that the next instruction + + + align:start position:0% +speculating that the next instruction +comes from PC plus four is wrong for + + align:start position:0% +comes from PC plus four is wrong for + + + align:start position:0% +comes from PC plus four is wrong for +jumps and taken branches looking at + + align:start position:0% +jumps and taken branches looking at + + + align:start position:0% +jumps and taken branches looking at +simulated execution traces will see that + + align:start position:0% +simulated execution traces will see that + + + align:start position:0% +simulated execution traces will see that +this error in speculation leads to about + + align:start position:0% +this error in speculation leads to about + + + align:start position:0% +this error in speculation leads to about +ten percent higher effective CPI can we + + align:start position:0% +ten percent higher effective CPI can we + + + align:start position:0% +ten percent higher effective CPI can we +do better this is an important question + + align:start position:0% +do better this is an important question + + + align:start position:0% +do better this is an important question +for CPUs with deep pipelines for example + + align:start position:0% +for CPUs with deep pipelines for example + + + align:start position:0% +for CPUs with deep pipelines for example +Intel's Nehalem processors from 2009 + + align:start position:0% +Intel's Nehalem processors from 2009 + + + align:start position:0% +Intel's Nehalem processors from 2009 +resolves the more complex x86 branch + + align:start position:0% +resolves the more complex x86 branch + + + align:start position:0% +resolves the more complex x86 branch +instructions quite late in the pipeline + + align:start position:0% +instructions quite late in the pipeline + + + align:start position:0% +instructions quite late in the pipeline +since Nehalem is capable of executing + + align:start position:0% +since Nehalem is capable of executing + + + align:start position:0% +since Nehalem is capable of executing +multiple instruction C cycle flushing + + align:start position:0% +multiple instruction C cycle flushing + + + align:start position:0% +multiple instruction C cycle flushing +the pipeline and Nehalem actually + + align:start position:0% +the pipeline and Nehalem actually + + + align:start position:0% +the pipeline and Nehalem actually +involves the execution of many + + align:start position:0% +involves the execution of many + + + align:start position:0% +involves the execution of many +instructions resulting in a considerable + + align:start position:0% +instructions resulting in a considerable + + + align:start position:0% +instructions resulting in a considerable +hit on the CPI like many modern + + align:start position:0% +hit on the CPI like many modern + + + align:start position:0% +hit on the CPI like many modern +processor implementations Nehalem has a + + align:start position:0% +processor implementations Nehalem has a + + + align:start position:0% +processor implementations Nehalem has a +much more sophisticated speculation + + align:start position:0% +much more sophisticated speculation + + + align:start position:0% +much more sophisticated speculation +mechanism rather than always guessing + + align:start position:0% +mechanism rather than always guessing + + + align:start position:0% +mechanism rather than always guessing +the next instruction is at PC plus 4 it + + align:start position:0% +the next instruction is at PC plus 4 it + + + align:start position:0% +the next instruction is at PC plus 4 it +only does that for non branch + + align:start position:0% +only does that for non branch + + + align:start position:0% +only does that for non branch +instructions for branches it predicts + + align:start position:0% +instructions for branches it predicts + + + align:start position:0% +instructions for branches it predicts +the behavior of each individual branch + + align:start position:0% +the behavior of each individual branch + + + align:start position:0% +the behavior of each individual branch +based on what the branch + + align:start position:0% +based on what the branch + + + align:start position:0% +based on what the branch +did last time it was executed and some + + align:start position:0% +did last time it was executed and some + + + align:start position:0% +did last time it was executed and some +knowledge of how the branch is being + + align:start position:0% +knowledge of how the branch is being + + + align:start position:0% +knowledge of how the branch is being +used for example backwards branches at + + align:start position:0% +used for example backwards branches at + + + align:start position:0% +used for example backwards branches at +the end of loops which are taken for all + + align:start position:0% +the end of loops which are taken for all + + + align:start position:0% +the end of loops which are taken for all +but the final iteration of the loop can + + align:start position:0% +but the final iteration of the loop can + + + align:start position:0% +but the final iteration of the loop can +be identified by their negative branch + + align:start position:0% +be identified by their negative branch + + + align:start position:0% +be identified by their negative branch +offset values Nehalem can even determine + + align:start position:0% +offset values Nehalem can even determine + + + align:start position:0% +offset values Nehalem can even determine +if there's a correlation between branch + + align:start position:0% +if there's a correlation between branch + + + align:start position:0% +if there's a correlation between branch +instructions using the results of an + + align:start position:0% +instructions using the results of an + + + align:start position:0% +instructions using the results of an +another earlier branch to speculate on + + align:start position:0% +another earlier branch to speculate on + + + align:start position:0% +another earlier branch to speculate on +the branch decision of the current + + align:start position:0% +the branch decision of the current + + + align:start position:0% +the branch decision of the current +branch with these sophisticated + + align:start position:0% +branch with these sophisticated + + + align:start position:0% +branch with these sophisticated +strategies Nehalem speculation is + + align:start position:0% +strategies Nehalem speculation is + + + align:start position:0% +strategies Nehalem speculation is +correct 95 to 99 percent of the time + + align:start position:0% +correct 95 to 99 percent of the time + + + align:start position:0% +correct 95 to 99 percent of the time +greatly reducing the impact of branches + + align:start position:0% +greatly reducing the impact of branches + + + align:start position:0% +greatly reducing the impact of branches +on the effective CPI there's also the + + align:start position:0% +on the effective CPI there's also the + + + align:start position:0% +on the effective CPI there's also the +lazy option of changing the is a to deal + + align:start position:0% +lazy option of changing the is a to deal + + + align:start position:0% +lazy option of changing the is a to deal +with control hazards for example we + + align:start position:0% +with control hazards for example we + + + align:start position:0% +with control hazards for example we +could change the is a to specify that + + align:start position:0% +could change the is a to specify that + + + align:start position:0% +could change the is a to specify that +the instruction following a jumper + + align:start position:0% +the instruction following a jumper + + + align:start position:0% +the instruction following a jumper +branch is always executed in other words + + align:start position:0% +branch is always executed in other words + + + align:start position:0% +branch is always executed in other words +the transfer of control happens after + + align:start position:0% +the transfer of control happens after + + + align:start position:0% +the transfer of control happens after +the next instruction this change ensures + + align:start position:0% +the next instruction this change ensures + + + align:start position:0% +the next instruction this change ensures +that the guess of PC plus 4 as the + + align:start position:0% +that the guess of PC plus 4 as the + + + align:start position:0% +that the guess of PC plus 4 as the +address of the next instruction is + + align:start position:0% +address of the next instruction is + + + align:start position:0% +address of the next instruction is +always correct in the example shown here + + align:start position:0% +always correct in the example shown here + + + align:start position:0% +always correct in the example shown here +assuming we change the is a we can + + align:start position:0% +assuming we change the is a we can + + + align:start position:0% +assuming we change the is a we can +reorganize the execution order of the + + align:start position:0% +reorganize the execution order of the + + + align:start position:0% +reorganize the execution order of the +loop to place the mall instruction after + + align:start position:0% +loop to place the mall instruction after + + + align:start position:0% +loop to place the mall instruction after +the be any instruction in the so called + + align:start position:0% +the be any instruction in the so called + + + align:start position:0% +the be any instruction in the so called +branch delay slot since the instruction + + align:start position:0% +branch delay slot since the instruction + + + align:start position:0% +branch delay slot since the instruction +in the branch delay slot is always + + align:start position:0% +in the branch delay slot is always + + + align:start position:0% +in the branch delay slot is always +executed the mall instruction will be + + align:start position:0% +executed the mall instruction will be + + + align:start position:0% +executed the mall instruction will be +executed during each iteration of the + + align:start position:0% +executed during each iteration of the + + + align:start position:0% +executed during each iteration of the +loop the resulting execution is shown in + + align:start position:0% +loop the resulting execution is shown in + + + align:start position:0% +loop the resulting execution is shown in +this pipeline diagram assuming we can + + align:start position:0% +this pipeline diagram assuming we can + + + align:start position:0% +this pipeline diagram assuming we can +find an appropriate instruction to place + + align:start position:0% +find an appropriate instruction to place + + + align:start position:0% +find an appropriate instruction to place +in the delay slot the branch will have + + align:start position:0% +in the delay slot the branch will have + + + align:start position:0% +in the delay slot the branch will have +zero impact on the effect of CPI our + + align:start position:0% +zero impact on the effect of CPI our + + + align:start position:0% +zero impact on the effect of CPI our +branch delay slots a good idea seems + + align:start position:0% +branch delay slots a good idea seems + + + align:start position:0% +branch delay slots a good idea seems +like they reduce the negative impact + + align:start position:0% +like they reduce the negative impact + + + align:start position:0% +like they reduce the negative impact +that branches might have on instruction + + align:start position:0% +that branches might have on instruction + + + align:start position:0% +that branches might have on instruction +throughput the downside is that only + + align:start position:0% +throughput the downside is that only + + + align:start position:0% +throughput the downside is that only +half of the time can we find + + align:start position:0% +half of the time can we find + + + align:start position:0% +half of the time can we find +instructions to move to the branch delay + + align:start position:0% +instructions to move to the branch delay + + + align:start position:0% +instructions to move to the branch delay +slot the other half of the time we have + + align:start position:0% +slot the other half of the time we have + + + align:start position:0% +slot the other half of the time we have +to fill it with an explicit no op + + align:start position:0% +to fill it with an explicit no op + + + align:start position:0% +to fill it with an explicit no op +instruction increasing the size of the + + align:start position:0% +instruction increasing the size of the + + + align:start position:0% +instruction increasing the size of the +code and if we make the branch decision + + align:start position:0% +code and if we make the branch decision + + + align:start position:0% +code and if we make the branch decision +later in the pipeline there are more two + + align:start position:0% +later in the pipeline there are more two + + + align:start position:0% +later in the pipeline there are more two +branch delay slots which would be even + + align:start position:0% +branch delay slots which would be even + + + align:start position:0% +branch delay slots which would be even +harder to fill in practice it turns out + + align:start position:0% +harder to fill in practice it turns out + + + align:start position:0% +harder to fill in practice it turns out +that branch prediction works better than + + align:start position:0% +that branch prediction works better than + + + align:start position:0% +that branch prediction works better than +delay slots in reducing the impact of + + align:start position:0% +delay slots in reducing the impact of + + + align:start position:0% +delay slots in reducing the impact of +branches so + + align:start position:0% +branches so + + + align:start position:0% +branches so +once again we see it's problematic to + + align:start position:0% +once again we see it's problematic to + + + align:start position:0% +once again we see it's problematic to +alter the is a to improve the throughput + + align:start position:0% +alter the is a to improve the throughput + + + align:start position:0% +alter the is a to improve the throughput +of pipeline execution ISAs outlive + + align:start position:0% +of pipeline execution ISAs outlive + + + align:start position:0% +of pipeline execution ISAs outlive +implementations so it's best not to + + align:start position:0% +implementations so it's best not to + + + align:start position:0% +implementations so it's best not to +change the execution semantics to deal + + align:start position:0% +change the execution semantics to deal + + + align:start position:0% +change the execution semantics to deal +with performance issues created by a + + align:start position:0% +with performance issues created by a + + + align:start position:0% +with performance issues created by a +particular implementation \ No newline at end of file diff --git a/0aMDzMhf528.txt b/0aMDzMhf528.txt new file mode 100644 index 0000000000000000000000000000000000000000..e3776474fad1a075b69ef0b7c8205cbee8693854 --- /dev/null +++ b/0aMDzMhf528.txt @@ -0,0 +1,212 @@ +For this problem, assume that we have a computer +system that has three devices D1, D2, and + +D3. + +Each of these devices can cause interrupts +in our system. + +This table summarizes the interrupt characteristics +of our three devices. + +For each device, we are given its service +time which is the amount of time it takes + +to service an interrupt for that particular +device. + +We are given an interrupt frequency which +tells us how frequently the interrupts for + +that device arrive. + +You can assume that the first interrupt of +each device can arrive at any time. + +The deadline is the longest amount of time +that is allowed between the interrupt request + +and the completion of the interrupt handler. + +Assume we have a program P that takes 100 +seconds to execute when interrupts are disabled. + +We would like to figure out how long it would +take to execute this program when interrupts + +are enabled. + +To answer this question, we need to determine +the amount of cpu time that is dedicated to + +the handling of each of the three devices. + +D1 has a service time of 400us and it runs +every 800us so it is using 400/800 or 50% + +of the cpu time. + +D2 has a service time of 250us and it runs +every 1000us so it is using 250/1000 or 25% + +of the cpu time. + +D3 uses 100/800 or 12.5% of the cpu time. + +This means that the user programs have the +remaining cpu time available to them. + +The remaining cpu time is 12.5% or 1/8 of +the cpu time. + +If the user program can only run for one eighth +of the time, that means that a program that + +takes 100 seconds without interrupts will +take 800 seconds to run with interrupts enabled. + +We want to consider whether there is a weak +priority ordering that could satisfy all of + +the constraints for this system? +Recall that with a weak priority ordering, + +there is no preemption, so if an interrupt +handler has begun running it runs to completion + +even if another interrupt of higher priority +arrives before its completion. + +Upon completion, all interrupts that have +arrived, regardless of their order of arrival, + +are processed in priority order. + +If there is a weak priority ordering that +satisfies our system, then we should determine + +the priority ordering. + +If there is no such ordering, then we should +identify the devices for which a weak priority + +ordering cannot guarantee meeting all the +constraints. + +Returning to our device characteristics table +and comparing our deadlines to the device + +service times, we see that in a weak priority +system if the D1 handler which has a service + +time of 400us happens to be running when a +D2 or D3 interrupt arrives, then the D2 or + +D3 devices could miss their deadlines because +the service time of D1 plus their own service + +time is greater than their deadline. + +In other words, if D2 or D3 have to wait up +to 400us before beginning to be serviced then + +their completion time won't be until 650us +for D2 which is greater than its deadline + +of 300us, and 500us for D3 which is greater +than its deadline of 400us. + +Thus, there is no weak priority system ordering +which is guaranteed to satisfy all of our + +system constraints. + +Now, lets reconsider the same question assuming +a strong priority ordering. + +Recall that with a strong priority ordering, +the handler for a device with a higher priority + +will pre-empt a running handler of a lower +priority device. + +In other words if the priority of A is greater +than B and an A interrupt arrives midway through + +the handling of a B interrupt, then the B +interrupt handler will get interrupted, the + +A handler will be run, and upon completion +of the A handler, the B handler will be resumed. + +If there is a strong priority ordering that +satisfies our system, then we should specify + +what it is. + +If there is no such ordering, then we should +identify the devices for which even a strong + +priority ordering cannot guarantee meeting +all the constraints. + +Since we now allow preemption of lower priority +device handlers in order to satisfy the requirements + +of a higher priority handler, we are no longer +faced with the issue that devices D2 and D3 + +can't meet their deadlines if D1 happens to +be running first. + +In addition, since at the beginning of our +problem we determined that there is enough + +time to service all of our interrupts given +their service times and interrupt frequencies, + +that means that there must exist a strong +priority ordering that can satisfy all the + +constraints of our system. + +You can use the scheme that a device with +a shorter deadline should have a higher priority + +than one with a longer deadline to arrive +at a valid strong priority ordering. + +A valid strong priority ordering is D2 has +the highest priority, then D3 and then D1. + +Another way of expressing this is D2 > D3 +> D1. + +Note that for this example, this priority +ordering is the only valid ordering that will + +satisfy all the constraints of our strong +priority system. + +To convince ourselves of this, let's take +a closer look at other priority possibilities + +and determine what would happen in those situations. + +If D1 had a higher priority than either D2 +or D3, then the deadlines for D2 and D3 would + +not be guaranteed to be satisfied. + +This means that D1 must have the lowest priority. + +Now between D2 and D3, if D3 had a higher +priority than D2, then if D3 was being serviced + +when a D2 interrupt arrived, the D2 interrupt +may not complete until 350us which is beyond + +its deadline. + +So this shows us that D2 must have the highest +priority, then D3 and finally D1. \ No newline at end of file diff --git a/0aa6fUHTTeU.txt b/0aa6fUHTTeU.txt new file mode 100644 index 0000000000000000000000000000000000000000..10270a76c863b2270fc08cc0bef4fe6bce706df8 --- /dev/null +++ b/0aa6fUHTTeU.txt @@ -0,0 +1,7931 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay ready to go + + align:start position:0% +ocw.mit.edu okay ready to go + + + align:start position:0% +ocw.mit.edu okay ready to go +on lecture five I guess this is um so + + align:start position:0% +on lecture five I guess this is um so + + + align:start position:0% +on lecture five I guess this is um so +this we've done the uh one-way wave + + align:start position:0% +this we've done the uh one-way wave + + + align:start position:0% +this we've done the uh one-way wave +equation uh first order equation and now + + align:start position:0% +equation uh first order equation and now + + + align:start position:0% +equation uh first order equation and now +it's just natural to see what about the + + align:start position:0% +it's just natural to see what about the + + + align:start position:0% +it's just natural to see what about the +Ordinary second order wave + + align:start position:0% +Ordinary second order wave + + + align:start position:0% +Ordinary second order wave +equation and uh on this board I've + + align:start position:0% +equation and uh on this board I've + + + align:start position:0% +equation and uh on this board I've +written it two ways I've written it as a + + align:start position:0% +written it two ways I've written it as a + + + align:start position:0% +written it two ways I've written it as a +second order equation so second time + + align:start position:0% +second order equation so second time + + + align:start position:0% +second order equation so second time +derivative appears that's going to make + + align:start position:0% +derivative appears that's going to make + + + align:start position:0% +derivative appears that's going to make +a change we're going to have uh if we'll + + align:start position:0% +a change we're going to have uh if we'll + + + align:start position:0% +a change we're going to have uh if we'll +have second differences in time so we're + + align:start position:0% +have second differences in time so we're + + + align:start position:0% +have second differences in time so we're +we're going to have more + + align:start position:0% +we're going to have more + + + align:start position:0% +we're going to have more +steps and uh of the same second + + align:start position:0% +steps and uh of the same second + + + align:start position:0% +steps and uh of the same second +difference a matching second difference + + align:start position:0% +difference a matching second difference + + + align:start position:0% +difference a matching second difference +in space and so that's one way then this + + align:start position:0% +in space and so that's one way then this + + + align:start position:0% +in space and so that's one way then this +is another important way to write the + + align:start position:0% +is another important way to write the + + + align:start position:0% +is another important way to write the +same + + align:start position:0% +same + + + align:start position:0% +same +equation as a first order system so I + + align:start position:0% +equation as a first order system so I + + + align:start position:0% +equation as a first order system so I +can get back to first order systems and + + align:start position:0% +can get back to first order systems and + + + align:start position:0% +can get back to first order systems and +I can use all those + + align:start position:0% +I can use all those + + + align:start position:0% +I can use all those +methods uh fried LAX friedrick for + + align:start position:0% +methods uh fried LAX friedrick for + + + align:start position:0% +methods uh fried LAX friedrick for +example LAX wend whatever improvements + + align:start position:0% +example LAX wend whatever improvements + + + align:start position:0% +example LAX wend whatever improvements +we think of + + align:start position:0% +we think of + + + align:start position:0% +we think of +uh on this first order system d by DT of + + align:start position:0% +uh on this first order system d by DT of + + + align:start position:0% +uh on this first order system d by DT of +a vector is a matrix times d by the x of + + align:start position:0% +a vector is a matrix times d by the x of + + + align:start position:0% +a vector is a matrix times d by the x of +the vector so that's a you really have a + + align:start position:0% +the vector so that's a you really have a + + + align:start position:0% +the vector so that's a you really have a +choice here and written this way well + + align:start position:0% +choice here and written this way well + + + align:start position:0% +choice here and written this way well +notice a little bit + + align:start position:0% +notice a little bit + + + align:start position:0% +notice a little bit +of uh good thing good one good thing + + align:start position:0% +of uh good thing good one good thing + + + align:start position:0% +of uh good thing good one good thing +here The Matrix that shows up is + + align:start position:0% +here The Matrix that shows up is + + + align:start position:0% +here The Matrix that shows up is +symmetric that was by the careful choice + + align:start position:0% +symmetric that was by the careful choice + + + align:start position:0% +symmetric that was by the careful choice +of putting a c in there then you see + + align:start position:0% +of putting a c in there then you see + + + align:start position:0% +of putting a c in there then you see +that the first equation in this system + + align:start position:0% +that the first equation in this system + + + align:start position:0% +that the first equation in this system +is utt is C time C + + align:start position:0% + + + + align:start position:0% + +uxx so the first equation is the wave + + align:start position:0% +uxx so the first equation is the wave + + + align:start position:0% +uxx so the first equation is the wave +equation and what about the second + + align:start position:0% +equation and what about the second + + + align:start position:0% +equation and what about the second +equation this is typical when you reduce + + align:start position:0% +equation this is typical when you reduce + + + align:start position:0% +equation this is typical when you reduce +things to a to a lower order system that + + align:start position:0% +things to a to a lower order system that + + + align:start position:0% +things to a to a lower order system that +you get an equation here which is just + + align:start position:0% +you get an equation here which is just + + + align:start position:0% +you get an equation here which is just +an identity the derivative of C the time + + align:start position:0% +an identity the derivative of C the time + + + align:start position:0% +an identity the derivative of C the time +this is C uxt it's the the derivative + + align:start position:0% +this is C uxt it's the the derivative + + + align:start position:0% +this is C uxt it's the the derivative +and x and t from there and we have c + + align:start position:0% +and x and t from there and we have c + + + align:start position:0% +and x and t from there and we have c +times the X derivative of UT the cross + + align:start position:0% +times the X derivative of UT the cross + + + align:start position:0% +times the X derivative of UT the cross +derivative so that is an identity + + align:start position:0% +derivative so that is an identity + + + align:start position:0% +derivative so that is an identity +because U TX is the same as uxt we can + + align:start position:0% +because U TX is the same as uxt we can + + + align:start position:0% +because U TX is the same as uxt we can +take time and x and t derivatives in + + align:start position:0% +take time and x and t derivatives in + + + align:start position:0% +take time and x and t derivatives in +either order for for a function of x and + + align:start position:0% +either order for for a function of x and + + + align:start position:0% +either order for for a function of x and +t so we'll see + + align:start position:0% + + + + align:start position:0% + +that I guess what I want to do in the + + align:start position:0% +that I guess what I want to do in the + + + align:start position:0% +that I guess what I want to do in the +lecture is not to + + align:start position:0% +lecture is not to + + + align:start position:0% +lecture is not to +repeat LAX freed Dres or LAX wend for + + align:start position:0% +repeat LAX freed Dres or LAX wend for + + + align:start position:0% +repeat LAX freed Dres or LAX wend for +this + + align:start position:0% +this + + + align:start position:0% +this +system that would + + align:start position:0% +system that would + + + align:start position:0% +system that would +be + + align:start position:0% +be + + + align:start position:0% +be +unexciting let me just mention what are + + align:start position:0% +unexciting let me just mention what are + + + align:start position:0% +unexciting let me just mention what are +the igen values of that Matrix so the + + align:start position:0% +the igen values of that Matrix so the + + + align:start position:0% +the igen values of that Matrix so the +igen value in the in a for a system it's + + align:start position:0% +igen value in the in a for a system it's + + + align:start position:0% +igen value in the in a for a system it's +the igen values of the Matrix that + + align:start position:0% +the igen values of the Matrix that + + + align:start position:0% +the igen values of the Matrix that +tell us what waves we've got what speeds + + align:start position:0% +tell us what waves we've got what speeds + + + align:start position:0% +tell us what waves we've got what speeds +they + + align:start position:0% +they + + + align:start position:0% +they +go where when it was one by1 of course + + align:start position:0% +go where when it was one by1 of course + + + align:start position:0% +go where when it was one by1 of course +it was just that single number c but + + align:start position:0% +it was just that single number c but + + + align:start position:0% +it was just that single number c but +what are the igen values of that Matrix + + align:start position:0% +what are the igen values of that Matrix + + + align:start position:0% +what are the igen values of that Matrix +now having made it a symmetric + + align:start position:0% +now having made it a symmetric + + + align:start position:0% +now having made it a symmetric +Matrix uh we know right away it has real + + align:start position:0% +Matrix uh we know right away it has real + + + align:start position:0% +Matrix uh we know right away it has real +igen values and so it's a wave + + align:start position:0% +igen values and so it's a wave + + + align:start position:0% +igen values and so it's a wave +problem for a heat equation we would we + + align:start position:0% +problem for a heat equation we would we + + + align:start position:0% +problem for a heat equation we would we +would see something + + align:start position:0% +would see something + + + align:start position:0% +would see something +different but this will be a wave + + align:start position:0% +different but this will be a wave + + + align:start position:0% +different but this will be a wave +equation and that this has two igen + + align:start position:0% +equation and that this has two igen + + + align:start position:0% +equation and that this has two igen +values and they are C and minus + + align:start position:0% +values and they are C and minus + + + align:start position:0% +values and they are C and minus +C just you could quickly check that that + + align:start position:0% +C just you could quickly check that that + + + align:start position:0% +C just you could quickly check that that +2x two Matrix has I values C and minus C + + align:start position:0% +2x two Matrix has I values C and minus C + + + align:start position:0% +2x two Matrix has I values C and minus C +they add up to zero which is the trace + + align:start position:0% +they add up to zero which is the trace + + + align:start position:0% +they add up to zero which is the trace +they multiply C * minus C is minus c^ 2 + + align:start position:0% +they multiply C * minus C is minus c^ 2 + + + align:start position:0% +they multiply C * minus C is minus c^ 2 +which is the determinant so that's + + align:start position:0% +which is the determinant so that's + + + align:start position:0% +which is the determinant so that's +they're the right igen values so that's + + align:start position:0% +they're the right igen values so that's + + + align:start position:0% +they're the right igen values so that's +going to tell us what we'll find every + + align:start position:0% +going to tell us what we'll find every + + + align:start position:0% +going to tell us what we'll find every +way that the speeds of the waves are C + + align:start position:0% +way that the speeds of the waves are C + + + align:start position:0% +way that the speeds of the waves are C +and minus C which means a wave going one + + align:start position:0% +and minus C which means a wave going one + + + align:start position:0% +and minus C which means a wave going one +way with speed c and a wave going the + + align:start position:0% +way with speed c and a wave going the + + + align:start position:0% +way with speed c and a wave going the +other way with speed + + align:start position:0% +other way with speed + + + align:start position:0% +other way with speed +C that's so so it's a two-way wave + + align:start position:0% +C that's so so it's a two-way wave + + + align:start position:0% +C that's so so it's a two-way wave +equation and this is the equation of + + align:start position:0% +equation and this is the equation of + + + align:start position:0% +equation and this is the equation of +real uh that really happens and I wanted + + align:start position:0% +real uh that really happens and I wanted + + + align:start position:0% +real uh that really happens and I wanted +to say just a little bit about just two + + align:start position:0% +to say just a little bit about just two + + + align:start position:0% +to say just a little bit about just two +words about real problems because we + + align:start position:0% +words about real problems because we + + + align:start position:0% +words about real problems because we +can't in in these first days tackle the + + align:start position:0% +can't in in these first days tackle the + + + align:start position:0% +can't in in these first days tackle the +difficult problems of + + align:start position:0% +difficult problems of + + + align:start position:0% +difficult problems of +electromagnetism antenna Decay design uh + + align:start position:0% +electromagnetism antenna Decay design uh + + + align:start position:0% +electromagnetism antenna Decay design uh +um all kinds of uh wave problems I I + + align:start position:0% +um all kinds of uh wave problems I I + + + align:start position:0% +um all kinds of uh wave problems I I +guess I'm hoping some of you may be + + align:start position:0% +guess I'm hoping some of you may be + + + align:start position:0% +guess I'm hoping some of you may be +meeting real wave problems in other + + align:start position:0% +meeting real wave problems in other + + + align:start position:0% +meeting real wave problems in other +courses and + + align:start position:0% +courses and + + + align:start position:0% +courses and +would uh make a project that that uh + + align:start position:0% +would uh make a project that that uh + + + align:start position:0% +would uh make a project that that uh +tries our methods on real problems I I I + + align:start position:0% +tries our methods on real problems I I I + + + align:start position:0% +tries our methods on real problems I I I +just wanted to write down here one sort + + align:start position:0% +just wanted to write down here one sort + + + align:start position:0% +just wanted to write down here one sort +of typical real problem so in a real + + align:start position:0% +of typical real problem so in a real + + + align:start position:0% +of typical real problem so in a real +problem we we have a a variable + + align:start position:0% +problem we we have a a variable + + + align:start position:0% +problem we we have a a variable +coefficient X because maybe our material + + align:start position:0% +coefficient X because maybe our material + + + align:start position:0% +coefficient X because maybe our material +is not homogeneous it's not + + align:start position:0% +is not homogeneous it's not + + + align:start position:0% +is not homogeneous it's not +uniform and we have a forcing + + align:start position:0% +uniform and we have a forcing + + + align:start position:0% +uniform and we have a forcing +term I is put f for the amplitude to + + align:start position:0% +term I is put f for the amplitude to + + + align:start position:0% +term I is put f for the amplitude to +emphasize that's forcing term so F + + align:start position:0% +emphasize that's forcing term so F + + + align:start position:0% +emphasize that's forcing term so F +standing for forcing but it's an + + align:start position:0% +standing for forcing but it's an + + + align:start position:0% +standing for forcing but it's an +oscillating forcing term it's a this is + + align:start position:0% +oscillating forcing term it's a this is + + + align:start position:0% +oscillating forcing term it's a this is +what you're going to have and in + + align:start position:0% +what you're going to have and in + + + align:start position:0% +what you're going to have and in +electromagnetism the frequency is going + + align:start position:0% +electromagnetism the frequency is going + + + align:start position:0% +electromagnetism the frequency is going +to be very very + + align:start position:0% +to be very very + + + align:start position:0% +to be very very +high and then uh so this is a problem + + align:start position:0% +high and then uh so this is a problem + + + align:start position:0% +high and then uh so this is a problem +that you that's not easy numerically + + align:start position:0% +that you that's not easy numerically + + + align:start position:0% +that you that's not easy numerically +very very high + + align:start position:0% +very very high + + + align:start position:0% +very very high +frequencies would normally require very + + align:start position:0% +frequencies would normally require very + + + align:start position:0% +frequencies would normally require very +very small wavelengths very very small + + align:start position:0% +very small wavelengths very very small + + + align:start position:0% +very small wavelengths very very small +Delta X because you you remember there + + align:start position:0% +Delta X because you you remember there + + + align:start position:0% +Delta X because you you remember there +would be a k Delta X in the eror + + align:start position:0% +would be a k Delta X in the eror + + + align:start position:0% +would be a k Delta X in the eror +so if we took a big Delta X and or even + + align:start position:0% +so if we took a big Delta X and or even + + + align:start position:0% +so if we took a big Delta X and or even +an ordinary size Delta X and let the + + align:start position:0% +an ordinary size Delta X and let the + + + align:start position:0% +an ordinary size Delta X and let the +frequency go way way up high high + + align:start position:0% +frequency go way way up high high + + + align:start position:0% +frequency go way way up high high +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +oscillation our K Delta X would be big + + align:start position:0% +oscillation our K Delta X would be big + + + align:start position:0% +oscillation our K Delta X would be big +and the accuracy would be poor and and + + align:start position:0% +and the accuracy would be poor and and + + + align:start position:0% +and the accuracy would be poor and and +the results useless so a lot of I'm + + align:start position:0% +the results useless so a lot of I'm + + + align:start position:0% +the results useless so a lot of I'm +really guess I'm thinking here about a + + align:start position:0% +really guess I'm thinking here about a + + + align:start position:0% +really guess I'm thinking here about a +course on wave + + align:start position:0% +course on wave + + + align:start position:0% +course on wave +propagation would study this as a first + + align:start position:0% +propagation would study this as a first + + + align:start position:0% +propagation would study this as a first +model problem + + align:start position:0% +model problem + + + align:start position:0% +model problem +get some do some analysis and then uh go + + align:start position:0% +get some do some analysis and then uh go + + + align:start position:0% +get some do some analysis and then uh go +into 2D and 3D that's uh that's the + + align:start position:0% +into 2D and 3D that's uh that's the + + + align:start position:0% +into 2D and 3D that's uh that's the +reality of of of wave theory is you get + + align:start position:0% +reality of of of wave theory is you get + + + align:start position:0% +reality of of of wave theory is you get +as you can get asymptotic results for K + + align:start position:0% +as you can get asymptotic results for K + + + align:start position:0% +as you can get asymptotic results for K +going to Infinity you get things things + + align:start position:0% +going to Infinity you get things things + + + align:start position:0% +going to Infinity you get things things +uh you're looking in in matching powers + + align:start position:0% +uh you're looking in in matching powers + + + align:start position:0% +uh you're looking in in matching powers +of K so to speak and you're getting + + align:start position:0% +of K so to speak and you're getting + + + align:start position:0% +of K so to speak and you're getting +plain waves and and interesting stuff + + align:start position:0% +plain waves and and interesting stuff + + + align:start position:0% +plain waves and and interesting stuff +that that's we can't do already right + + align:start position:0% +that that's we can't do already right + + + align:start position:0% +that that's we can't do already right +away here so I I'm going back to the + + align:start position:0% +away here so I I'm going back to the + + + align:start position:0% +away here so I I'm going back to the +ordinary wave equation either second + + align:start position:0% +ordinary wave equation either second + + + align:start position:0% +ordinary wave equation either second +start with second order UT is c^2 uxx + + align:start position:0% +start with second order UT is c^2 uxx + + + align:start position:0% +start with second order UT is c^2 uxx +okay that's our + + align:start position:0% +okay that's our + + + align:start position:0% +okay that's our +goal and as I said we don't want to see + + align:start position:0% +goal and as I said we don't want to see + + + align:start position:0% +goal and as I said we don't want to see +LAX friedricks and LAX wend again we + + align:start position:0% +LAX friedricks and LAX wend again we + + + align:start position:0% +LAX friedricks and LAX wend again we +know + + align:start position:0% +know + + + align:start position:0% +know +those it's uh rather one so one new + + align:start position:0% +those it's uh rather one so one new + + + align:start position:0% +those it's uh rather one so one new +method is going to show + + align:start position:0% +method is going to show + + + align:start position:0% +method is going to show +up one and it's Leap Frog is the right + + align:start position:0% +up one and it's Leap Frog is the right + + + align:start position:0% +up one and it's Leap Frog is the right +name natural name to give it Leap Frog + + align:start position:0% +name natural name to give it Leap Frog + + + align:start position:0% +name natural name to give it Leap Frog +because well in the time direction we + + align:start position:0% +because well in the time direction we + + + align:start position:0% +because well in the time direction we +have time n minus one n and n plus one + + align:start position:0% +have time n minus one n and n plus one + + + align:start position:0% +have time n minus one n and n plus one +there's a leap there but let me start + + align:start position:0% +there's a leap there but let me start + + + align:start position:0% +there's a leap there but let me start +with semi discreete we haven't done + + align:start position:0% +with semi discreete we haven't done + + + align:start position:0% +with semi discreete we haven't done +this until + + align:start position:0% +this until + + + align:start position:0% +this until +today semidiscrete + + align:start position:0% +today semidiscrete + + + align:start position:0% +today semidiscrete +means as you see that the time variable + + align:start position:0% +means as you see that the time variable + + + align:start position:0% +means as you see that the time variable +stays + + align:start position:0% +stays + + + align:start position:0% +stays +continuous we have ordinary differential + + align:start position:0% +continuous we have ordinary differential + + + align:start position:0% +continuous we have ordinary differential +equations in + + align:start position:0% +equations in + + + align:start position:0% +equations in +t but the space variable is what's + + align:start position:0% +t but the space variable is what's + + + align:start position:0% +t but the space variable is what's +getting discrete so the problem is like + + align:start position:0% +getting discrete so the problem is like + + + align:start position:0% +getting discrete so the problem is like +half discreete discrete in X but not + + align:start position:0% +half discreete discrete in X but not + + + align:start position:0% +half discreete discrete in X but not +there's a Delta X but there's no delta T + + align:start position:0% +there's a Delta X but there's no delta T + + + align:start position:0% +there's a Delta X but there's no delta T +yet so so it's natural to like analyze + + align:start position:0% +yet so so it's natural to like analyze + + + align:start position:0% +yet so so it's natural to like analyze +this + + align:start position:0% +this + + + align:start position:0% +this +problem and what so what do we have + + align:start position:0% +problem and what so what do we have + + + align:start position:0% +problem and what so what do we have +really we have in the X direction we + + align:start position:0% +really we have in the X direction we + + + align:start position:0% +really we have in the X direction we +have a mesh of width Delta X so we have + + align:start position:0% +have a mesh of width Delta X so we have + + + align:start position:0% +have a mesh of width Delta X so we have +unknowns that if that's + + align:start position:0% +unknowns that if that's + + + align:start position:0% +unknowns that if that's +zero J is measuring so J Delta J Delta X + + align:start position:0% +zero J is measuring so J Delta J Delta X + + + align:start position:0% +zero J is measuring so J Delta J Delta X +is the is the typical + + align:start position:0% +is the is the typical + + + align:start position:0% +is the is the typical +point point number J along there and + + align:start position:0% +point point number J along there and + + + align:start position:0% +point point number J along there and +then in the time direction we're going + + align:start position:0% +then in the time direction we're going + + + align:start position:0% +then in the time direction we're going +continuously so I don't have discrete + + align:start position:0% +continuously so I don't have discrete + + + align:start position:0% +continuously so I don't have discrete +steps + + align:start position:0% +steps + + + align:start position:0% +steps +so it's called because those are lines + + align:start position:0% +so it's called because those are lines + + + align:start position:0% +so it's called because those are lines +in the time Direction This is + + align:start position:0% +in the time Direction This is + + + align:start position:0% +in the time Direction This is +semidiscrete is also referred to as the + + align:start position:0% +semidiscrete is also referred to as the + + + align:start position:0% +semidiscrete is also referred to as the +method of + + align:start position:0% +method of + + + align:start position:0% +method of +lines so the method of lines is this is + + align:start position:0% +lines so the method of lines is this is + + + align:start position:0% +lines so the method of lines is this is +what we're doing here and it's all I + + align:start position:0% +what we're doing here and it's all I + + + align:start position:0% +what we're doing here and it's all I +want to do + + align:start position:0% +want to do + + + align:start position:0% +want to do +is what I always + + align:start position:0% +is what I always + + + align:start position:0% +is what I always +do take + + align:start position:0% +do take + + + align:start position:0% +do take +exponentials look at their growth + + align:start position:0% +exponentials look at their growth + + + align:start position:0% +exponentials look at their growth +factors understand the equation well + + align:start position:0% +factors understand the equation well + + + align:start position:0% +factors understand the equation well +actually I better do it first with the + + align:start position:0% +actually I better do it first with the + + + align:start position:0% +actually I better do it first with the +wave equation itself so so I guess my my + + align:start position:0% +wave equation itself so so I guess my my + + + align:start position:0% +wave equation itself so so I guess my my +Organization for today + + align:start position:0% +Organization for today + + + align:start position:0% +Organization for today +is first step is follow e to the + + align:start position:0% +is first step is follow e to the + + + align:start position:0% +is first step is follow e to the +ikx for the wave equation so I'll do + + align:start position:0% +ikx for the wave equation so I'll do + + + align:start position:0% +ikx for the wave equation so I'll do +that here + + align:start position:0% +that here + + + align:start position:0% +that here +utt equals c^2 + + align:start position:0% +utt equals c^2 + + + align:start position:0% +utt equals c^2 +uxx and I'm going to look at U + + align:start position:0% +uxx and I'm going to look at U + + + align:start position:0% +uxx and I'm going to look at U +proportional to and I'll call this + + align:start position:0% +proportional to and I'll call this + + + align:start position:0% +proportional to and I'll call this +Factor G again G of t + + align:start position:0% +Factor G again G of t + + + align:start position:0% +Factor G again G of t +and times the frequency I + + align:start position:0% + + + + align:start position:0% + +KX so I'm going to look for Pure + + align:start position:0% +KX so I'm going to look for Pure + + + align:start position:0% +KX so I'm going to look for Pure +exponentials okay and we'll quickly find + + align:start position:0% +exponentials okay and we'll quickly find + + + align:start position:0% +exponentials okay and we'll quickly find +them and then I'm going to do the same + + align:start position:0% +them and then I'm going to do the same + + + align:start position:0% +them and then I'm going to do the same +for semidiscrete where that X becomes J + + align:start position:0% +for semidiscrete where that X becomes J + + + align:start position:0% +for semidiscrete where that X becomes J +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +X and I'm at Point J and then I'm going + + align:start position:0% +X and I'm at Point J and then I'm going + + + align:start position:0% +X and I'm at Point J and then I'm going +to + + align:start position:0% + + + + align:start position:0% + +eventually look at the Le discrete now + + align:start position:0% +eventually look at the Le discrete now + + + align:start position:0% +eventually look at the Le discrete now +fully + + align:start position:0% +fully + + + align:start position:0% +fully +discrete discrete in time and discrete + + align:start position:0% +discrete discrete in time and discrete + + + align:start position:0% +discrete discrete in time and discrete +in + + align:start position:0% +in + + + align:start position:0% +in +space and + + align:start position:0% +space and + + + align:start position:0% +space and +uh the question of stability arises + + align:start position:0% +uh the question of stability arises + + + align:start position:0% +uh the question of stability arises +accuracy we can you pretty much we + + align:start position:0% +accuracy we can you pretty much we + + + align:start position:0% +accuracy we can you pretty much we +pretty much know the accuracy for second + + align:start position:0% +pretty much know the accuracy for second + + + align:start position:0% +pretty much know the accuracy for second +differences the that's a second order + + align:start position:0% +differences the that's a second order + + + align:start position:0% +differences the that's a second order +accurate thing because it's centered but + + align:start position:0% +accurate thing because it's centered but + + + align:start position:0% +accurate thing because it's centered but +stability is going to come + + align:start position:0% + + + + align:start position:0% + +in + + align:start position:0% + + + + align:start position:0% + +okay so that's this is our first + + align:start position:0% +okay so that's this is our first + + + align:start position:0% +okay so that's this is our first +step and and and then I'll just mention + + align:start position:0% +step and and and then I'll just mention + + + align:start position:0% +step and and and then I'll just mention +what other point remains in this in this + + align:start position:0% +what other point remains in this in this + + + align:start position:0% +what other point remains in this in this +uh wave equation is to look at the uh + + align:start position:0% +uh wave equation is to look at the uh + + + align:start position:0% +uh wave equation is to look at the uh +first order + + align:start position:0% + + + + align:start position:0% + +system how does that look in + + align:start position:0% +system how does that look in + + + align:start position:0% +system how does that look in +uh space and + + align:start position:0% +uh space and + + + align:start position:0% +uh space and +time well as I + + align:start position:0% +time well as I + + + align:start position:0% +time well as I +said + + align:start position:0% +said + + + align:start position:0% +said +the obvious thing to do would be LAX + + align:start position:0% +the obvious thing to do would be LAX + + + align:start position:0% +the obvious thing to do would be LAX +friedricks or LAX wend but there's + + align:start position:0% +friedricks or LAX wend but there's + + + align:start position:0% +friedricks or LAX wend but there's +another + + align:start position:0% +another + + + align:start position:0% +another +idea and it brings in uh a staggered + + align:start position:0% +idea and it brings in uh a staggered + + + align:start position:0% +idea and it brings in uh a staggered +grid the well you'll see + + align:start position:0% +grid the well you'll see + + + align:start position:0% +grid the well you'll see +it somehow that staggered grid is really + + align:start position:0% +it somehow that staggered grid is really + + + align:start position:0% +it somehow that staggered grid is really +an important idea that we haven't met + + align:start position:0% +an important idea that we haven't met + + + align:start position:0% +an important idea that we haven't met +yet that some unknowns are on the + + align:start position:0% +yet that some unknowns are on the + + + align:start position:0% +yet that some unknowns are on the +standard + + align:start position:0% +standard + + + align:start position:0% +standard +grid + + align:start position:0% +grid + + + align:start position:0% +grid +ujn the other unknowns are on uh a a + + align:start position:0% +ujn the other unknowns are on uh a a + + + align:start position:0% +ujn the other unknowns are on uh a a +grid that's that's half a Delta X and + + align:start position:0% +grid that's that's half a Delta X and + + + align:start position:0% +grid that's that's half a Delta X and +half a delta T + + align:start position:0% +half a delta T + + + align:start position:0% +half a delta T +different and it's just right actually + + align:start position:0% +different and it's just right actually + + + align:start position:0% +different and it's just right actually +so that's the that's a premier method in + + align:start position:0% +so that's the that's a premier method in + + + align:start position:0% +so that's the that's a premier method in +electromagnetism so that's that's what's + + align:start position:0% +electromagnetism so that's that's what's + + + align:start position:0% +electromagnetism so that's that's what's +coming but let's start with the second + + align:start position:0% +coming but let's start with the second + + + align:start position:0% +coming but let's start with the second +order method because we haven't seen + + align:start position:0% +order method because we haven't seen + + + align:start position:0% +order method because we haven't seen +second order methods before okay second + + align:start position:0% +second order methods before okay second + + + align:start position:0% +second order methods before okay second +order equation plug in G + + align:start position:0% +order equation plug in G + + + align:start position:0% +order equation plug in G +okay so I have the second time + + align:start position:0% +okay so I have the second time + + + align:start position:0% +okay so I have the second time +derivative gives me G + + align:start position:0% +derivative gives me G + + + align:start position:0% +derivative gives me G +Prime Time e to the ik KX see I'm + + align:start position:0% +Prime Time e to the ik KX see I'm + + + align:start position:0% +Prime Time e to the ik KX see I'm +separating variables of course T here + + align:start position:0% +separating variables of course T here + + + align:start position:0% +separating variables of course T here +and X there and on the other side I have + + align:start position:0% +and X there and on the other side I have + + + align:start position:0% +and X there and on the other side I have +c^2 now I have the X variable so that's + + align:start position:0% +c^2 now I have the X variable so that's + + + align:start position:0% +c^2 now I have the X variable so that's +brings down an i k so that's I k^ + + align:start position:0% +brings down an i k so that's I k^ + + + align:start position:0% +brings down an i k so that's I k^ +SAR time g e to the I + + align:start position:0% +SAR time g e to the I + + + align:start position:0% +SAR time g e to the I +KX good + + align:start position:0% +KX good + + + align:start position:0% +KX good +so simple but but uh substituting + + align:start position:0% +so simple but but uh substituting + + + align:start position:0% +so simple but but uh substituting +this is just a natural first step to see + + align:start position:0% +this is just a natural first step to see + + + align:start position:0% +this is just a natural first step to see +what's happening and then of course + + align:start position:0% +what's happening and then of course + + + align:start position:0% +what's happening and then of course +canceling e to the I KX leaves us with + + align:start position:0% +canceling e to the I KX leaves us with + + + align:start position:0% +canceling e to the I KX leaves us with +the equation for the G gble + + align:start position:0% +the equation for the G gble + + + align:start position:0% +the equation for the G gble +Prime is I'll make that i^2 minus minus + + align:start position:0% +Prime is I'll make that i^2 minus minus + + + align:start position:0% +Prime is I'll make that i^2 minus minus +c^ 2 k^ 2 + + align:start position:0% +c^ 2 k^ 2 + + + align:start position:0% +c^ 2 k^ 2 +G and of course the new aspect is it's + + align:start position:0% +G and of course the new aspect is it's + + + align:start position:0% +G and of course the new aspect is it's +second order so it's got two solutions + + align:start position:0% +second order so it's got two solutions + + + align:start position:0% +second order so it's got two solutions +instead of just one it's constant + + align:start position:0% +instead of just one it's constant + + + align:start position:0% +instead of just one it's constant +coefficients of + + align:start position:0% +coefficients of + + + align:start position:0% +coefficients of +course and so we look for + + align:start position:0% +course and so we look for + + + align:start position:0% +course and so we look for +exponentials and the solution then would + + align:start position:0% +exponentials and the solution then would + + + align:start position:0% +exponentials and the solution then would +be two solutions are uh + + align:start position:0% +be two solutions are uh + + + align:start position:0% +be two solutions are uh +some there's a e to the I I guess I'm + + align:start position:0% +some there's a e to the I I guess I'm + + + align:start position:0% +some there's a e to the I I guess I'm +bringing back the i e e to the i c k t e + + align:start position:0% +bringing back the i e e to the i c k t e + + + align:start position:0% +bringing back the i e e to the i c k t e +to the I + + align:start position:0% +to the I + + + align:start position:0% +to the I +KX + + align:start position:0% + + + + align:start position:0% + +and e to the minus i c k t e to the I + + align:start position:0% +and e to the minus i c k t e to the I + + + align:start position:0% +and e to the minus i c k t e to the I +KX so those are the two possible + + align:start position:0% +KX so those are the two possible + + + align:start position:0% +KX so those are the two possible +G's those are + + align:start position:0% +G's those are + + + align:start position:0% +G's those are +the those are if we take their second + + align:start position:0% +the those are if we take their second + + + align:start position:0% +the those are if we take their second +time + + align:start position:0% +time + + + align:start position:0% +time +derivative we get uh uh the same as + + align:start position:0% +derivative we get uh uh the same as + + + align:start position:0% +derivative we get uh uh the same as +taking the second X derivative there + + align:start position:0% +taking the second X derivative there + + + align:start position:0% +taking the second X derivative there +well we get the factor C is in the right + + align:start position:0% +well we get the factor C is in the right + + + align:start position:0% +well we get the factor C is in the right +place you you see it the second time + + align:start position:0% +place you you see it the second time + + + align:start position:0% +place you you see it the second time +derivative brings this Factor down just + + align:start position:0% +derivative brings this Factor down just + + + align:start position:0% +derivative brings this Factor down just +as we wanted but the point is that there + + align:start position:0% +as we wanted but the point is that there + + + align:start position:0% +as we wanted but the point is that there +are two of them there's a so this this I + + align:start position:0% +are two of them there's a so this this I + + + align:start position:0% +are two of them there's a so this this I +can write as e to the i k x minus C X + + align:start position:0% +can write as e to the i k x minus C X + + + align:start position:0% +can write as e to the i k x minus C X +Plus CT that's our old + + align:start position:0% +Plus CT that's our old + + + align:start position:0% +Plus CT that's our old +friend and this one I can write right as + + align:start position:0% +friend and this one I can write right as + + + align:start position:0% +friend and this one I can write right as +e to the i k xus + + align:start position:0% +e to the i k xus + + + align:start position:0% +e to the i k xus +CT which is our new friend the new wave + + align:start position:0% +CT which is our new friend the new wave + + + align:start position:0% +CT which is our new friend the new wave +the wave that's going to the right so + + align:start position:0% +the wave that's going to the right so + + + align:start position:0% +the wave that's going to the right so +this is a this X Plus CT is follows the + + align:start position:0% +this is a this X Plus CT is follows the + + + align:start position:0% +this is a this X Plus CT is follows the +characteristic lines to the left just + + align:start position:0% +characteristic lines to the left just + + + align:start position:0% +characteristic lines to the left just +the just the way we had in the oneway + + align:start position:0% +the just the way we had in the oneway + + + align:start position:0% +the just the way we had in the oneway +wave + + align:start position:0% +wave + + + align:start position:0% +wave +equation this x minus + + align:start position:0% +equation this x minus + + + align:start position:0% +equation this x minus +CT a con says constant on characteris + + align:start position:0% +CT a con says constant on characteris + + + align:start position:0% +CT a con says constant on characteris +itic lines going up to the + + align:start position:0% +itic lines going up to the + + + align:start position:0% +itic lines going up to the +right that it travels with speed + + align:start position:0% +right that it travels with speed + + + align:start position:0% +right that it travels with speed +C and uh the signal travels along those + + align:start position:0% +C and uh the signal travels along those + + + align:start position:0% +C and uh the signal travels along those +characteristics with speed C so that a + + align:start position:0% +characteristics with speed C so that a + + + align:start position:0% +characteristics with speed C so that a +an initial an initial value now maybe I + + align:start position:0% +an initial an initial value now maybe I + + + align:start position:0% +an initial an initial value now maybe I +draw draw a picture over + + align:start position:0% +draw draw a picture over + + + align:start position:0% +draw draw a picture over +here so here's T equals this is X as + + align:start position:0% +here so here's T equals this is X as + + + align:start position:0% +here so here's T equals this is X as +always this is Tal Z I have some initial + + align:start position:0% +always this is Tal Z I have some initial + + + align:start position:0% +always this is Tal Z I have some initial +value U at 0 0 and I also have an + + align:start position:0% +value U at 0 0 and I also have an + + + align:start position:0% +value U at 0 0 and I also have an +initial velocity because I'm + + align:start position:0% +initial velocity because I'm + + + align:start position:0% +initial velocity because I'm +in got a second order equation but + + align:start position:0% +in got a second order equation but + + + align:start position:0% +in got a second order equation but +information somehow pure exponential + + align:start position:0% +information somehow pure exponential + + + align:start position:0% +information somehow pure exponential +information travels along + + align:start position:0% +information travels along + + + align:start position:0% +information travels along +characteristics this way that's the new + + align:start position:0% +characteristics this way that's the new + + + align:start position:0% +characteristics this way that's the new +one and characteristics this way that's + + align:start position:0% +one and characteristics this way that's + + + align:start position:0% +one and characteristics this way that's +the old one this is this is time space + + align:start position:0% +the old one this is this is time space + + + align:start position:0% +the old one this is this is time space +I'm not graph I'm graphing the two + + align:start position:0% +I'm not graph I'm graphing the two + + + align:start position:0% +I'm not graph I'm graphing the two +characteristic lines now + + align:start position:0% +characteristic lines now + + + align:start position:0% +characteristic lines now +x minus CT equals well if it starts from + + align:start position:0% +x minus CT equals well if it starts from + + + align:start position:0% +x minus CT equals well if it starts from +zero then it would be zero and this is + + align:start position:0% +zero then it would be zero and this is + + + align:start position:0% +zero then it would be zero and this is +the X Plus + + align:start position:0% +the X Plus + + + align:start position:0% +the X Plus +CT equals z the one we had before the + + align:start position:0% +CT equals z the one we had before the + + + align:start position:0% +CT equals z the one we had before the +two characteristic lines + + align:start position:0% +two characteristic lines + + + align:start position:0% +two characteristic lines +okay waves are going both + + align:start position:0% + + + + align:start position:0% + +ways right and now what we were able to + + align:start position:0% +ways right and now what we were able to + + + align:start position:0% +ways right and now what we were able to +do with the first order + + align:start position:0% +do with the first order + + + align:start position:0% +do with the first order +equation we even got + + align:start position:0% +equation we even got + + + align:start position:0% +equation we even got +uh a completely explicit solution to the + + align:start position:0% +uh a completely explicit solution to the + + + align:start position:0% +uh a completely explicit solution to the +to the one-way wave equation and we can + + align:start position:0% +to the one-way wave equation and we can + + + align:start position:0% +to the one-way wave equation and we can +do the same for the two-way wave + + align:start position:0% +do the same for the two-way wave + + + align:start position:0% +do the same for the two-way wave +equation so I better write it down I + + align:start position:0% +equation so I better write it down I + + + align:start position:0% +equation so I better write it down I +better write down the solution so so let + + align:start position:0% +better write down the solution so so let + + + align:start position:0% +better write down the solution so so let +me just continue this same idea the + + align:start position:0% +me just continue this same idea the + + + align:start position:0% +me just continue this same idea the +general the complete + + align:start position:0% + + + + align:start position:0% + +solution will be + + align:start position:0% +solution will be + + + align:start position:0% +solution will be +U of x and t is some function of x minus + + align:start position:0% +U of x and t is some function of x minus + + + align:start position:0% +U of x and t is some function of x minus +CT and some function of call it FS2 of x + + align:start position:0% +CT and some function of call it FS2 of x + + + align:start position:0% +CT and some function of call it FS2 of x ++ + + align:start position:0% + + + + align:start position:0% + +CT oh not I've taken the + + align:start position:0% +CT oh not I've taken the + + + align:start position:0% +CT oh not I've taken the +jump the jump from one exponential a + + align:start position:0% +jump the jump from one exponential a + + + align:start position:0% +jump the jump from one exponential a +particular K that gave me these + + align:start position:0% +particular K that gave me these + + + align:start position:0% +particular K that gave me these +particular guys + + align:start position:0% + + + + align:start position:0% + +to all + + align:start position:0% +to all + + + align:start position:0% +to all +exponentials and assembling all + + align:start position:0% +exponentials and assembling all + + + align:start position:0% +exponentials and assembling all +exponentials into functions well so why + + align:start position:0% +exponentials into functions well so why + + + align:start position:0% +exponentials into functions well so why +is that okay it's only okay in this + + align:start position:0% +is that okay it's only okay in this + + + align:start position:0% +is that okay it's only okay in this +because of this very special situation + + align:start position:0% +because of this very special situation + + + align:start position:0% +because of this very special situation +that all frequencies are behaving the + + align:start position:0% +that all frequencies are behaving the + + + align:start position:0% +that all frequencies are behaving the +same here all + + align:start position:0% +same here all + + + align:start position:0% +same here all +frequencies I have no + + align:start position:0% +frequencies I have no + + + align:start position:0% +frequencies I have no +dispersion dispersion is is going to be + + align:start position:0% +dispersion dispersion is is going to be + + + align:start position:0% +dispersion dispersion is is going to be +different behavior of different + + align:start position:0% +different behavior of different + + + align:start position:0% +different behavior of different +frequencies so that's an important fact + + align:start position:0% +frequencies so that's an important fact + + + align:start position:0% +frequencies so that's an important fact +which we don't face + + align:start position:0% +which we don't face + + + align:start position:0% +which we don't face +here there will be dispersion in the + + align:start position:0% +here there will be dispersion in the + + + align:start position:0% +here there will be dispersion in the +discrete methods the semidiscrete and + + align:start position:0% +discrete methods the semidiscrete and + + + align:start position:0% +discrete methods the semidiscrete and +the discret methods different + + align:start position:0% +the discret methods different + + + align:start position:0% +the discret methods different +frequencies will travel at different + + align:start position:0% +frequencies will travel at different + + + align:start position:0% +frequencies will travel at different +speeds and that's what produces the + + align:start position:0% +speeds and that's what produces the + + + align:start position:0% +speeds and that's what produces the +oscillating error whatever shape the + + align:start position:0% +oscillating error whatever shape the + + + align:start position:0% +oscillating error whatever shape the +error has is because different Ks are + + align:start position:0% +error has is because different Ks are + + + align:start position:0% +error has is because different Ks are +doing slightly different things as we'll + + align:start position:0% +doing slightly different things as we'll + + + align:start position:0% +doing slightly different things as we'll +see when we do the discrete ones + + align:start position:0% +see when we do the discrete ones + + + align:start position:0% +see when we do the discrete ones +but in the continuous case every K we + + align:start position:0% +but in the continuous case every K we + + + align:start position:0% +but in the continuous case every K we +have the same traveling either with + + align:start position:0% +have the same traveling either with + + + align:start position:0% +have the same traveling either with +speed C or minus C and therefore we put + + align:start position:0% +speed C or minus C and therefore we put + + + align:start position:0% +speed C or minus C and therefore we put +them all together and we have a whole + + align:start position:0% +them all together and we have a whole + + + align:start position:0% +them all together and we have a whole +function traveling with speed C or minus + + align:start position:0% +function traveling with speed C or minus + + + align:start position:0% +function traveling with speed C or minus +C and now we got two + + align:start position:0% +C and now we got two + + + align:start position:0% +C and now we got two +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +functions and we have we have to match + + align:start position:0% +functions and we have we have to match + + + align:start position:0% +functions and we have we have to match +two initial conditions we have to match + + align:start position:0% +two initial conditions we have to match + + + align:start position:0% +two initial conditions we have to match +we have to we have to match a u of X and + + align:start position:0% +we have to we have to match a u of X and + + + align:start position:0% +we have to we have to match a u of X and +zero and and the time derivative has to + + align:start position:0% +zero and and the time derivative has to + + + align:start position:0% +zero and and the time derivative has to +match a UT of X and zero so these are + + align:start position:0% +match a UT of X and zero so these are + + + align:start position:0% +match a UT of X and zero so these are +the initial + + align:start position:0% +the initial + + + align:start position:0% +the initial +conditions and uh you just match them up + + align:start position:0% +conditions and uh you just match them up + + + align:start position:0% +conditions and uh you just match them up +and you find the answer so you discover + + align:start position:0% +and you find the answer so you discover + + + align:start position:0% +and you find the answer so you discover +what these functions really are and it + + align:start position:0% +what these functions really are and it + + + align:start position:0% +what these functions really are and it +turns out that I think we had you + + align:start position:0% +turns out that I think we had you + + + align:start position:0% +turns out that I think we had you +remember before we had a u of x + C T + + align:start position:0% +remember before we had a u of x + C T + + + align:start position:0% +remember before we had a u of x + C T +and zero that was our that was + + align:start position:0% +and zero that was our that was + + + align:start position:0% +and zero that was our that was +everything in the + + align:start position:0% +everything in the + + + align:start position:0% +everything in the +solution to the oneway wave equation now + + align:start position:0% +solution to the oneway wave equation now + + + align:start position:0% +solution to the oneway wave equation now +we will have U of x minus + + align:start position:0% +we will have U of x minus + + + align:start position:0% +we will have U of x minus +ct0 and this divided by + + align:start position:0% + + + + align:start position:0% + +two so there you see a waves going each + + align:start position:0% +two so there you see a waves going each + + + align:start position:0% +two so there you see a waves going each +way and the division by two makes us ma + + align:start position:0% +way and the division by two makes us ma + + + align:start position:0% +way and the division by two makes us ma +now we're matching the initial + + align:start position:0% +now we're matching the initial + + + align:start position:0% +now we're matching the initial +condition + + align:start position:0% +condition + + + align:start position:0% +condition +so that would be the total answer if + + align:start position:0% +so that would be the total answer if + + + align:start position:0% +so that would be the total answer if +the equation if this if the body starts + + align:start position:0% +the equation if this if the body starts + + + align:start position:0% +the equation if this if the body starts +from rest with zero velocity but I + + align:start position:0% +from rest with zero velocity but I + + + align:start position:0% +from rest with zero velocity but I +haven't + + align:start position:0% +haven't + + + align:start position:0% +haven't +matched so I've only matched dudt equals + + align:start position:0% +matched so I've only matched dudt equals + + + align:start position:0% +matched so I've only matched dudt equals +z I think the time derivative of that + + align:start position:0% +z I think the time derivative of that + + + align:start position:0% +z I think the time derivative of that +would be zero yeah because the time + + align:start position:0% +would be zero yeah because the time + + + align:start position:0% +would be zero yeah because the time +derivative this would bring out a c this + + align:start position:0% +derivative this would bring out a c this + + + align:start position:0% +derivative this would bring out a c this +would bring out a minus C and at T + + align:start position:0% +would bring out a minus C and at T + + + align:start position:0% +would bring out a minus C and at T +equals z they'd cancel so I need + + align:start position:0% +equals z they'd cancel so I need + + + align:start position:0% +equals z they'd cancel so I need +uh another term and it turns out to be + + align:start position:0% +uh another term and it turns out to be + + + align:start position:0% +uh another term and it turns out to be +I'll just write it down it's got to + + align:start position:0% +I'll just write it down it's got to + + + align:start position:0% +I'll just write it down it's got to +depend on x minus CT and X+ CT and it's + + align:start position:0% +depend on x minus CT and X+ CT and it's + + + align:start position:0% +depend on x minus CT and X+ CT and it's +this it's the integral of this + + align:start position:0% +this it's the integral of this + + + align:start position:0% +this it's the integral of this +velocity + + align:start position:0% + + + + align:start position:0% + +DX all right well there's no reason to + + align:start position:0% +DX all right well there's no reason to + + + align:start position:0% +DX all right well there's no reason to +take time to derive that I think it's + + align:start position:0% +take time to derive that I think it's + + + align:start position:0% +take time to derive that I think it's +right and good check it + + align:start position:0% +right and good check it + + + align:start position:0% +right and good check it +right so what this means is that the + + align:start position:0% +right so what this means is that the + + + align:start position:0% +right so what this means is that the +initial velocity is + + align:start position:0% +initial velocity is + + + align:start position:0% +initial velocity is +uh uh yeah it it's entering somehow all + + align:start position:0% +uh uh yeah it it's entering somehow all + + + align:start position:0% +uh uh yeah it it's entering somehow all +along somehow the initial velocity is is + + align:start position:0% +along somehow the initial velocity is is + + + align:start position:0% +along somehow the initial velocity is is +affecting + + align:start position:0% +affecting + + + align:start position:0% +affecting +uh things within within + + align:start position:0% +uh things within within + + + align:start position:0% +uh things within within +this + + align:start position:0% +this + + + align:start position:0% +this +cone this characteristic cone of uh + + align:start position:0% +cone this characteristic cone of uh + + + align:start position:0% +cone this characteristic cone of uh +that's that's uh defined by the + + align:start position:0% +that's that's uh defined by the + + + align:start position:0% +that's that's uh defined by the +characteristic + + align:start position:0% +characteristic + + + align:start position:0% +characteristic +lines and in two Dimensions that cone + + align:start position:0% +lines and in two Dimensions that cone + + + align:start position:0% +lines and in two Dimensions that cone +will really look like a cone it'll look + + align:start position:0% +will really look like a cone it'll look + + + align:start position:0% +will really look like a cone it'll look +like an ice cream cone or maybe that's + + align:start position:0% +like an ice cream cone or maybe that's + + + align:start position:0% +like an ice cream cone or maybe that's +in three + + align:start position:0% +in three + + + align:start position:0% +in three +dimensions yeah + + align:start position:0% +dimensions yeah + + + align:start position:0% +dimensions yeah +whatever the in other words uh if the + + align:start position:0% +whatever the in other words uh if the + + + align:start position:0% +whatever the in other words uh if the +initial condition was a Delta function + + align:start position:0% +initial condition was a Delta function + + + align:start position:0% +initial condition was a Delta function +at the + + align:start position:0% +at the + + + align:start position:0% +at the +origin you could quickly see what the + + align:start position:0% +origin you could quickly see what the + + + align:start position:0% +origin you could quickly see what the +solution would + + align:start position:0% +solution would + + + align:start position:0% +solution would +be and if the Delta if the initial + + align:start position:0% +be and if the Delta if the initial + + + align:start position:0% +be and if the Delta if the initial +condition was a step function at the + + align:start position:0% +condition was a step function at the + + + align:start position:0% +condition was a step function at the +origin what would happen then suppose I + + align:start position:0% +origin what would happen then suppose I + + + align:start position:0% +origin what would happen then suppose I +start with a step function at the + + align:start position:0% +start with a step function at the + + + align:start position:0% +start with a step function at the +origin so like a wall of + + align:start position:0% +origin so like a wall of + + + align:start position:0% +origin so like a wall of +water and suppose it's at rest so it + + align:start position:0% +water and suppose it's at rest so it + + + align:start position:0% +water and suppose it's at rest so it +nothing it it's at at moment T equals + + align:start position:0% +nothing it it's at at moment T equals + + + align:start position:0% +nothing it it's at at moment T equals +zero I remove the + + align:start position:0% +zero I remove the + + + align:start position:0% +zero I remove the +dam and the water + + align:start position:0% +dam and the water + + + align:start position:0% +dam and the water +starts water flows then this term is + + align:start position:0% +starts water flows then this term is + + + align:start position:0% +starts water flows then this term is +zero because there was no initial + + align:start position:0% +zero because there was no initial + + + align:start position:0% +zero because there was no initial +velocity and this term is just half of + + align:start position:0% +velocity and this term is just half of + + + align:start position:0% +velocity and this term is just half of +that wall goes one way and half goes the + + align:start position:0% +that wall goes one way and half goes the + + + align:start position:0% +that wall goes one way and half goes the +other way and the the notes draw a + + align:start position:0% +other way and the the notes draw a + + + align:start position:0% +other way and the the notes draw a +picture of that solution yeah so + + align:start position:0% +picture of that solution yeah so + + + align:start position:0% +picture of that solution yeah so +that's okay I've kind of quickly + + align:start position:0% +that's okay I've kind of quickly + + + align:start position:0% +that's okay I've kind of quickly +disposed of + + align:start position:0% +disposed of + + + align:start position:0% +disposed of +the the solution of the wave + + align:start position:0% +the the solution of the wave + + + align:start position:0% +the the solution of the wave +equation and of course you know that + + align:start position:0% +equation and of course you know that + + + align:start position:0% +equation and of course you know that +that's too too easy this is + + align:start position:0% + + + + align:start position:0% + +uh I mean that's good to know and good + + align:start position:0% +uh I mean that's good to know and good + + + align:start position:0% +uh I mean that's good to know and good +to compare when we meet real problems + + align:start position:0% +to compare when we meet real problems + + + align:start position:0% +to compare when we meet real problems +where C depends on X where there's a + + align:start position:0% +where C depends on X where there's a + + + align:start position:0% +where C depends on X where there's a +forcing term where there where there's + + align:start position:0% +forcing term where there where there's + + + align:start position:0% +forcing term where there where there's +real complications okay and but it's + + align:start position:0% +real complications okay and but it's + + + align:start position:0% +real complications okay and but it's +it's just pce to stay with the model + + align:start position:0% +it's just pce to stay with the model + + + align:start position:0% +it's just pce to stay with the model +problems for the at the beginning so I'm + + align:start position:0% +problems for the at the beginning so I'm + + + align:start position:0% +problems for the at the beginning so I'm +I'm going to stay with the model problem + + align:start position:0% +I'm going to stay with the model problem + + + align:start position:0% +I'm going to stay with the model problem +and move on + + align:start position:0% +and move on + + + align:start position:0% +and move on +to + + align:start position:0% +to + + + align:start position:0% +to +um discreet so so try to understand let + + align:start position:0% +um discreet so so try to understand let + + + align:start position:0% +um discreet so so try to understand let +me try to understand what happens if I + + align:start position:0% +me try to understand what happens if I + + + align:start position:0% +me try to understand what happens if I +make the space variable + + align:start position:0% +make the space variable + + + align:start position:0% +make the space variable +discret right yeah this is + + align:start position:0% +discret right yeah this is + + + align:start position:0% +discret right yeah this is +a oh I guess I should + + align:start position:0% +a oh I guess I should + + + align:start position:0% +a oh I guess I should +say another step toward reality would be + + align:start position:0% +say another step toward reality would be + + + align:start position:0% +say another step toward reality would be +have some + + align:start position:0% +have some + + + align:start position:0% +have some +boundaries I uh here this is on the + + align:start position:0% +boundaries I uh here this is on the + + + align:start position:0% +boundaries I uh here this is on the +whole line X from minus infinity to + + align:start position:0% +whole line X from minus infinity to + + + align:start position:0% +whole line X from minus infinity to +Infinity so reality would be that there + + align:start position:0% +Infinity so reality would be that there + + + align:start position:0% +Infinity so reality would be that there +would be this picture would have some + + align:start position:0% +would be this picture would have some + + + align:start position:0% +would be this picture would have some +boundary maybe + + align:start position:0% +boundary maybe + + + align:start position:0% +boundary maybe +there at say minus L and + + align:start position:0% +there at say minus L and + + + align:start position:0% +there at say minus L and +L and some boundary conditions there and + + align:start position:0% +L and some boundary conditions there and + + + align:start position:0% +L and some boundary conditions there and +on that + + align:start position:0% +on that + + + align:start position:0% +on that +boundary and that + + align:start position:0% +boundary and that + + + align:start position:0% +boundary and that +so now we have a finite problem that + + align:start position:0% +so now we have a finite problem that + + + align:start position:0% +so now we have a finite problem that +means the calculations are fine but it + + align:start position:0% +means the calculations are fine but it + + + align:start position:0% +means the calculations are fine but it +means some new effects are coming in + + align:start position:0% +means some new effects are coming in + + + align:start position:0% +means some new effects are coming in +waves can bounce back off the boundary + + align:start position:0% +waves can bounce back off the boundary + + + align:start position:0% +waves can bounce back off the boundary +partly they + + align:start position:0% +partly they + + + align:start position:0% +partly they +can go out be be lost go beyond go + + align:start position:0% +can go out be be lost go beyond go + + + align:start position:0% +can go out be be lost go beyond go +beyond or or or disappear depending what + + align:start position:0% +beyond or or or disappear depending what + + + align:start position:0% +beyond or or or disappear depending what +the boundary conditions are so that's + + align:start position:0% +the boundary conditions are so that's + + + align:start position:0% +the boundary conditions are so that's +another part of reality is boundary + + align:start position:0% +another part of reality is boundary + + + align:start position:0% +another part of reality is boundary +conditions I I I'm probably suggesting + + align:start position:0% +conditions I I I'm probably suggesting + + + align:start position:0% +conditions I I I'm probably suggesting +then some + + align:start position:0% +then some + + + align:start position:0% +then some +uh uh more realistic numerical + + align:start position:0% +uh uh more realistic numerical + + + align:start position:0% +uh uh more realistic numerical +experiments so a realistic numerical + + align:start position:0% +experiments so a realistic numerical + + + align:start position:0% +experiments so a realistic numerical +experiment would be put in some + + align:start position:0% +experiment would be put in some + + + align:start position:0% +experiment would be put in some +boundaries make this a finite + + align:start position:0% +boundaries make this a finite + + + align:start position:0% +boundaries make this a finite +system so so if that's zero let's let's + + align:start position:0% +system so so if that's zero let's let's + + + align:start position:0% +system so so if that's zero let's let's +just have a finite number and stop there + + align:start position:0% +just have a finite number and stop there + + + align:start position:0% +just have a finite number and stop there +this is this would be one boundary this + + align:start position:0% +this is this would be one boundary this + + + align:start position:0% +this is this would be one boundary this +would be the other then have just like + + align:start position:0% +would be the other then have just like + + + align:start position:0% +would be the other then have just like +seven unknowns in that problem there' be + + align:start position:0% +seven unknowns in that problem there' be + + + align:start position:0% +seven unknowns in that problem there' be +a 7 by seven Matrix over there and it + + align:start position:0% +a 7 by seven Matrix over there and it + + + align:start position:0% +a 7 by seven Matrix over there and it +would be the second difference Matrix + + align:start position:0% +would be the second difference Matrix + + + align:start position:0% +would be the second difference Matrix +that uh was so fundamental in uh is so + + align:start position:0% +that uh was so fundamental in uh is so + + + align:start position:0% +that uh was so fundamental in uh is so +fundamental in uh all of uh scientific + + align:start position:0% +fundamental in uh all of uh scientific + + + align:start position:0% +fundamental in uh all of uh scientific +Computing so we have here a second + + align:start position:0% +Computing so we have here a second + + + align:start position:0% +Computing so we have here a second +difference Matrix but it's infinite + + align:start position:0% +difference Matrix but it's infinite + + + align:start position:0% +difference Matrix but it's infinite +because because I haven't got a boundary + + align:start position:0% +because because I haven't got a boundary + + + align:start position:0% +because because I haven't got a boundary +right now so that that the fact of not + + align:start position:0% +right now so that that the fact of not + + + align:start position:0% +right now so that that the fact of not +having a boundary means forier is ready + + align:start position:0% +having a boundary means forier is ready + + + align:start position:0% +having a boundary means forier is ready +to go so I'm going to plug in I'm going + + align:start position:0% +to go so I'm going to plug in I'm going + + + align:start position:0% +to go so I'm going to plug in I'm going +to again I'm going to try + + align:start position:0% +to again I'm going to try + + + align:start position:0% +to again I'm going to try +U this is capital u now because I've + + align:start position:0% +U this is capital u now because I've + + + align:start position:0% +U this is capital u now because I've +discretized + + align:start position:0% + + + + align:start position:0% + +something and uh oh I better write this + + align:start position:0% +something and uh oh I better write this + + + align:start position:0% +something and uh oh I better write this +in a in a form where we see the J so can + + align:start position:0% +in a in a form where we see the J so can + + + align:start position:0% +in a in a form where we see the J so can +I write this equation just again for U + + align:start position:0% +I write this equation just again for U + + + align:start position:0% +I write this equation just again for U +number J so tracking up this line for + + align:start position:0% +number J so tracking up this line for + + + align:start position:0% +number J so tracking up this line for +example or this one so I'm tracking up + + align:start position:0% +example or this one so I'm tracking up + + + align:start position:0% +example or this one so I'm tracking up +this + + align:start position:0% +this + + + align:start position:0% +this +line you see that U is now a system in + + align:start position:0% +line you see that U is now a system in + + + align:start position:0% +line you see that U is now a system in +this + + align:start position:0% +this + + + align:start position:0% +this +case uh let's see I shouldn't have put + + align:start position:0% +case uh let's see I shouldn't have put + + + align:start position:0% +case uh let's see I shouldn't have put +this one in so that I'd have 1 two 3 + + align:start position:0% +this one in so that I'd have 1 two 3 + + + align:start position:0% +this one in so that I'd have 1 two 3 +four five six seven that's good yep + + align:start position:0% +four five six seven that's good yep + + + align:start position:0% +four five six seven that's good yep +so so my unknowns are UJ tracking up + + align:start position:0% +so so my unknowns are UJ tracking up + + + align:start position:0% +so so my unknowns are UJ tracking up +that line + + align:start position:0% +that line + + + align:start position:0% +that line +each UJ is is is going in in the time + + align:start position:0% +each UJ is is is going in in the time + + + align:start position:0% +each UJ is is is going in in the time +Direction so my my so this equation is + + align:start position:0% +Direction so my my so this equation is + + + align:start position:0% +Direction so my my so this equation is +really uh the time + + align:start position:0% +really uh the time + + + align:start position:0% +really uh the time +derivative it's an ordinary + + align:start position:0% +derivative it's an ordinary + + + align:start position:0% +derivative it's an ordinary +derivative I can write D and not partial + + align:start position:0% +derivative I can write D and not partial + + + align:start position:0% +derivative I can write D and not partial +derivative because the only derivatives + + align:start position:0% +derivative because the only derivatives + + + align:start position:0% +derivative because the only derivatives +here are in time of + + align:start position:0% +here are in time of + + + align:start position:0% +here are in time of +UJ is c^2 over Delta + + align:start position:0% +UJ is c^2 over Delta + + + align:start position:0% +UJ is c^2 over Delta +x^2 time u j + 1 - 2 u + + align:start position:0% +x^2 time u j + 1 - 2 u + + + align:start position:0% +x^2 time u j + 1 - 2 u +j plus u j minus one that's my + + align:start position:0% +j plus u j minus one that's my + + + align:start position:0% +j plus u j minus one that's my +equation my system of equations sorry my + + align:start position:0% +equation my system of equations sorry my + + + align:start position:0% +equation my system of equations sorry my +system of + + align:start position:0% +system of + + + align:start position:0% +system of +equations and for the moment I'm + + align:start position:0% +equations and for the moment I'm + + + align:start position:0% +equations and for the moment I'm +thinking J goes from minus infinity to + + align:start position:0% +thinking J goes from minus infinity to + + + align:start position:0% +thinking J goes from minus infinity to +Infinity I'm not going to put in a + + align:start position:0% +Infinity I'm not going to put in a + + + align:start position:0% +Infinity I'm not going to put in a +boundary okay but what I will do of + + align:start position:0% +boundary okay but what I will do of + + + align:start position:0% +boundary okay but what I will do of +course is try you + + align:start position:0% +course is try you + + + align:start position:0% +course is try you +UJ is + + align:start position:0% + + + + align:start position:0% + +some is some growth factor that J is a + + align:start position:0% +some is some growth factor that J is a + + + align:start position:0% +some is some growth factor that J is a +space is counting space steps so the + + align:start position:0% +space is counting space steps so the + + + align:start position:0% +space is counting space steps so the +growth factor is in time and it's + + align:start position:0% +growth factor is in time and it's + + + align:start position:0% +growth factor is in time and it's +continuous in time because time is + + align:start position:0% +continuous in time because time is + + + align:start position:0% +continuous in time because time is +continuous but + + align:start position:0% +continuous but + + + align:start position:0% +continuous but +it's it's always e to the i k j Delta + + align:start position:0% + + + + align:start position:0% + +X + + align:start position:0% +X + + + align:start position:0% +X +right that's the right thing to plug in + + align:start position:0% +right that's the right thing to plug in + + + align:start position:0% +right that's the right thing to plug in +I mean I guess what we're what I'm + + align:start position:0% +I mean I guess what we're what I'm + + + align:start position:0% +I mean I guess what we're what I'm +really uh the reason for really doing + + align:start position:0% +really uh the reason for really doing + + + align:start position:0% +really uh the reason for really doing +this is just + + align:start position:0% +this is just + + + align:start position:0% +this is just +to reinforce the idea that trying a pure + + align:start position:0% +to reinforce the idea that trying a pure + + + align:start position:0% +to reinforce the idea that trying a pure +exponential is a good thing to do it's + + align:start position:0% +exponential is a good thing to do it's + + + align:start position:0% +exponential is a good thing to do it's +even a good thing to do with variable + + align:start position:0% +even a good thing to do with variable + + + align:start position:0% +even a good thing to do with variable +coefficients and and and real + + align:start position:0% +coefficients and and and real + + + align:start position:0% +coefficients and and and real +problems and it's absolutely a good + + align:start position:0% +problems and it's absolutely a good + + + align:start position:0% +problems and it's absolutely a good +thing to do with these model problems + + align:start position:0% +thing to do with these model problems + + + align:start position:0% +thing to do with these model problems +okay plug it in and what + + align:start position:0% +okay plug it in and what + + + align:start position:0% +okay plug it in and what +happens okay so the so I get G + + align:start position:0% +happens okay so the so I get G + + + align:start position:0% +happens okay so the so I get G +Prime Times the exponential but of + + align:start position:0% +Prime Times the exponential but of + + + align:start position:0% +Prime Times the exponential but of +course you know in advance I'm going to + + align:start position:0% +course you know in advance I'm going to + + + align:start position:0% +course you know in advance I'm going to +cancel that exponential is c^2 over + + align:start position:0% +cancel that exponential is c^2 over + + + align:start position:0% +cancel that exponential is c^2 over +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +x^2 times what goes there what what will + + align:start position:0% +x^2 times what goes there what what will + + + align:start position:0% +x^2 times what goes there what what will +cancel the exponential so so I'm I'm + + align:start position:0% +cancel the exponential so so I'm I'm + + + align:start position:0% +cancel the exponential so so I'm I'm +imagining that exponential is far out + + align:start position:0% +imagining that exponential is far out + + + align:start position:0% +imagining that exponential is far out +but here it is a j + one so + + align:start position:0% +but here it is a j + one so + + + align:start position:0% +but here it is a j + one so +I I I've incremented J by one so that's + + align:start position:0% +I I I've incremented J by one so that's + + + align:start position:0% +I I I've incremented J by one so that's +is going to give me an e to the i k + + align:start position:0% +is going to give me an e to the i k + + + align:start position:0% +is going to give me an e to the i k +Delta X + + align:start position:0% +Delta X + + + align:start position:0% +Delta X +right here I haven't incremented it and + + align:start position:0% +right here I haven't incremented it and + + + align:start position:0% +right here I haven't incremented it and +here I've incremented it by minus one so + + align:start position:0% +here I've incremented it by minus one so + + + align:start position:0% +here I've incremented it by minus one so +that will give me an e to the minus i k + + align:start position:0% +that will give me an e to the minus i k + + + align:start position:0% +that will give me an e to the minus i k +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +X all times this same exponential which + + align:start position:0% +X all times this same exponential which + + + align:start position:0% +X all times this same exponential which +appeared there and appeared there and + + align:start position:0% +appeared there and appeared there and + + + align:start position:0% +appeared there and appeared there and +got cancelled so that that's it there + + align:start position:0% +got cancelled so that that's it there + + + align:start position:0% +got cancelled so that that's it there +gouble + + align:start position:0% + + + + align:start position:0% + +Prime oh there's got to be a G right + + align:start position:0% +Prime oh there's got to be a G right + + + align:start position:0% +Prime oh there's got to be a G right +there's a g + + align:start position:0% + + + + align:start position:0% + +here right right when I plugged in on + + align:start position:0% +here right right when I plugged in on + + + align:start position:0% +here right right when I plugged in on +the right hand side I got a g that was + + align:start position:0% +the right hand side I got a g that was + + + align:start position:0% +the right hand side I got a g that was +so uninteresting I lost it + + align:start position:0% +so uninteresting I lost it + + + align:start position:0% +so uninteresting I lost it +okay what + + align:start position:0% +okay what + + + align:start position:0% +okay what +does what's G + + align:start position:0% + + + + align:start position:0% + +there I guess the main point to see is + + align:start position:0% +there I guess the main point to see is + + + align:start position:0% +there I guess the main point to see is +this + + align:start position:0% + + + + align:start position:0% + +quantity which is divided Delta x + + align:start position:0% + + + + align:start position:0% + +s which is coming because we have + + align:start position:0% +s which is coming because we have + + + align:start position:0% +s which is coming because we have +differences instead of derivatives when + + align:start position:0% +differences instead of derivatives when + + + align:start position:0% +differences instead of derivatives when +we had derivatives that quantity was c^2 + + align:start position:0% +we had derivatives that quantity was c^2 + + + align:start position:0% +we had derivatives that quantity was c^2 +I K2 + + align:start position:0% + + + + align:start position:0% + +or in other words minus c^2 + + align:start position:0% +or in other words minus c^2 + + + align:start position:0% +or in other words minus c^2 +K2 that this was this was + + align:start position:0% +K2 that this was this was + + + align:start position:0% +K2 that this was this was +the the + + align:start position:0% +the the + + + align:start position:0% +the the +correct uh factor and this one is the + + align:start position:0% +correct uh factor and this one is the + + + align:start position:0% +correct uh factor and this one is the +discrete factor and and it's worth just + + align:start position:0% +discrete factor and and it's worth just + + + align:start position:0% +discrete factor and and it's worth just +paying a moment of attention to the to + + align:start position:0% +paying a moment of attention to the to + + + align:start position:0% +paying a moment of attention to the to +compare the + + align:start position:0% +compare the + + + align:start position:0% +compare the +two to compare the two okay okay where + + align:start position:0% +two to compare the two okay okay where + + + align:start position:0% +two to compare the two okay okay where +am I going to write that + + align:start position:0% +am I going to write that + + + align:start position:0% +am I going to write that +comparison I guess it's going to be on + + align:start position:0% +comparison I guess it's going to be on + + + align:start position:0% +comparison I guess it's going to be on +the board that's hidden so I'm going + + align:start position:0% +the board that's hidden so I'm going + + + align:start position:0% +the board that's hidden so I'm going +to can you try to remember that let me + + align:start position:0% +to can you try to remember that let me + + + align:start position:0% +to can you try to remember that let me +let me Focus just on this quantity for + + align:start position:0% +let me Focus just on this quantity for + + + align:start position:0% +let me Focus just on this quantity for +the minute or even just on this + + align:start position:0% +the minute or even just on this + + + align:start position:0% +the minute or even just on this +one just because we see it so many times + + align:start position:0% +one just because we see it so many times + + + align:start position:0% +one just because we see it so many times +because it's coming directly from second + + align:start position:0% +because it's coming directly from second + + + align:start position:0% +because it's coming directly from second +differences uh for the moment let me + + align:start position:0% +differences uh for the moment let me + + + align:start position:0% +differences uh for the moment let me +take K Delta X I'll just call it Theta + + align:start position:0% +take K Delta X I'll just call it Theta + + + align:start position:0% +take K Delta X I'll just call it Theta +it's some angle so can I just do a + + align:start position:0% +it's some angle so can I just do a + + + align:start position:0% +it's some angle so can I just do a +little bit of trig with this + + align:start position:0% +little bit of trig with this + + + align:start position:0% +little bit of trig with this +factor + + align:start position:0% +factor + + + align:start position:0% +factor +to minus 2 cos Theta let's see I'm gonna + + align:start position:0% +to minus 2 cos Theta let's see I'm gonna + + + align:start position:0% +to minus 2 cos Theta let's see I'm gonna +I'm going to bring out a minus sign so + + align:start position:0% +I'm going to bring out a minus sign so + + + align:start position:0% +I'm going to bring out a minus sign so +I'm going to I'm going to put plus signs + + align:start position:0% +I'm going to I'm going to put plus signs + + + align:start position:0% +I'm going to I'm going to put plus signs +on those and minus signs on those oh oh + + align:start position:0% +on those and minus signs on those oh oh + + + align:start position:0% +on those and minus signs on those oh oh +of course you see the main point of of + + align:start position:0% +of course you see the main point of of + + + align:start position:0% +of course you see the main point of of +course that e the plus something e to + + align:start position:0% +course that e the plus something e to + + + align:start position:0% +course that e the plus something e to +the I Theta and e to the minus I Theta + + align:start position:0% +the I Theta and e to the minus I Theta + + + align:start position:0% +the I Theta and e to the minus I Theta +combined to + + align:start position:0% +combined to + + + align:start position:0% +combined to +give 2 cos Theta right so that's the key + + align:start position:0% +give 2 cos Theta right so that's the key + + + align:start position:0% +give 2 cos Theta right so that's the key +simplification that's going to make this + + align:start position:0% +simplification that's going to make this + + + align:start position:0% +simplification that's going to make this +much neater so I have 2 cos Theta minus + + align:start position:0% +much neater so I have 2 cos Theta minus + + + align:start position:0% +much neater so I have 2 cos Theta minus +2 have 2 cos Theta minus 2 and if I + + align:start position:0% +2 have 2 cos Theta minus 2 and if I + + + align:start position:0% +2 have 2 cos Theta minus 2 and if I +bring out a minus sign I'll have 2 minus + + align:start position:0% +bring out a minus sign I'll have 2 minus + + + align:start position:0% +bring out a minus sign I'll have 2 minus +2 cos Theta and that's what I want to + + align:start position:0% +2 cos Theta and that's what I want to + + + align:start position:0% +2 cos Theta and that's what I want to +write I want to write 2us 2 cos Theta I + + align:start position:0% +write I want to write 2us 2 cos Theta I + + + align:start position:0% +write I want to write 2us 2 cos Theta I +just want to see what + + align:start position:0% +just want to see what + + + align:start position:0% +just want to see what +that's + + align:start position:0% +that's + + + align:start position:0% +that's +what that's uh I want to see what that + + align:start position:0% +what that's uh I want to see what that + + + align:start position:0% +what that's uh I want to see what that +expression + + align:start position:0% +expression + + + align:start position:0% +expression +is right so that brought out a minus + + align:start position:0% +is right so that brought out a minus + + + align:start position:0% +is right so that brought out a minus +sign just to match that minus + + align:start position:0% +sign just to match that minus + + + align:start position:0% +sign just to match that minus +sign and uh the C squs + + align:start position:0% +sign and uh the C squs + + + align:start position:0% +sign and uh the C squs +match but what's different is this K + + align:start position:0% +match but what's different is this K + + + align:start position:0% +match but what's different is this K +squar is now gone into this + + align:start position:0% +squar is now gone into this + + + align:start position:0% +squar is now gone into this +2- 2 cos K Delta X I'll write it divided + + align:start position:0% +2- 2 cos K Delta X I'll write it divided + + + align:start position:0% +2- 2 cos K Delta X I'll write it divided +by Delta + + align:start position:0% +by Delta + + + align:start position:0% +by Delta +X2 do you see that this + + align:start position:0% +X2 do you see that this + + + align:start position:0% +X2 do you see that this +is that's the change k^2 which is a + + align:start position:0% +is that's the change k^2 which is a + + + align:start position:0% +is that's the change k^2 which is a +positive quantity became this which is + + align:start position:0% +positive quantity became this which is + + + align:start position:0% +positive quantity became this which is +also a positive quantity 2 minus 2 cos + + align:start position:0% +also a positive quantity 2 minus 2 cos + + + align:start position:0% +also a positive quantity 2 minus 2 cos +Theta but it's not a pure K + + align:start position:0% +Theta but it's not a pure K + + + align:start position:0% +Theta but it's not a pure K +squ we are getting + + align:start position:0% +squ we are getting + + + align:start position:0% +squ we are getting +dispersion different + + align:start position:0% +dispersion different + + + align:start position:0% +dispersion different +frequencies are showing up inside the + + align:start position:0% +frequencies are showing up inside the + + + align:start position:0% +frequencies are showing up inside the +cosine and that's not a linear function + + align:start position:0% +cosine and that's not a linear function + + + align:start position:0% +cosine and that's not a linear function +so we're seeing uh we're seeing + + align:start position:0% +so we're seeing uh we're seeing + + + align:start position:0% +so we're seeing uh we're seeing +different frequencies going their own + + align:start position:0% +different frequencies going their own + + + align:start position:0% +different frequencies going their own +way in a more uh more interesting more + + align:start position:0% +way in a more uh more interesting more + + + align:start position:0% +way in a more uh more interesting more +way than just what we saw here with K + + align:start position:0% +way than just what we saw here with K + + + align:start position:0% +way than just what we saw here with K +squ and of course when we take the + + align:start position:0% +squ and of course when we take the + + + align:start position:0% +squ and of course when we take the +square root as we did here that produced + + align:start position:0% +square root as we did here that produced + + + align:start position:0% +square root as we did here that produced +linear in K and no dispersion and and + + align:start position:0% +linear in K and no dispersion and and + + + align:start position:0% +linear in K and no dispersion and and +uh something simple but here when we + + align:start position:0% +uh something simple but here when we + + + align:start position:0% +uh something simple but here when we +take the square root okay let's take + + align:start position:0% +take the square root okay let's take + + + align:start position:0% +take the square root okay let's take +let's get ready to take the square root + + align:start position:0% +let's get ready to take the square root + + + align:start position:0% +let's get ready to take the square root +how can we take the square root of + + align:start position:0% + + + + align:start position:0% + +that by writing it as a + + align:start position:0% +that by writing it as a + + + align:start position:0% +that by writing it as a +square it's never it's it's never + + align:start position:0% +square it's never it's it's never + + + align:start position:0% +square it's never it's it's never +negative and if I use a little + + align:start position:0% +negative and if I use a little + + + align:start position:0% +negative and if I use a little +trigonometry so I'm just going to write + + align:start position:0% +trigonometry so I'm just going to write + + + align:start position:0% +trigonometry so I'm just going to write +it down this is + + align:start position:0% +it down this is + + + align:start position:0% +it down this is +four I think it's sin + + align:start position:0% +four I think it's sin + + + align:start position:0% +four I think it's sin +squared of theta over + + align:start position:0% + + + + align:start position:0% + +2 that's just handy + + align:start position:0% +2 that's just handy + + + align:start position:0% +2 that's just handy +fact it's handy because I can take its + + align:start position:0% +fact it's handy because I can take its + + + align:start position:0% +fact it's handy because I can take its +square root and really see what so Theta + + align:start position:0% +square root and really see what so Theta + + + align:start position:0% +square root and really see what so Theta +remember this Theta is standing for K + + align:start position:0% +remember this Theta is standing for K + + + align:start position:0% +remember this Theta is standing for K +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +X so then I should I want to divide it + + align:start position:0% +X so then I should I want to divide it + + + align:start position:0% +X so then I should I want to divide it +by Delta x^ s can I bring down that + + align:start position:0% +by Delta x^ s can I bring down that + + + align:start position:0% +by Delta x^ s can I bring down that +quantity just so you see it again so + + align:start position:0% +quantity just so you see it again so + + + align:start position:0% +quantity just so you see it again so +this was the 2 - 2 cos Theta with the + + align:start position:0% +this was the 2 - 2 cos Theta with the + + + align:start position:0% +this was the 2 - 2 cos Theta with the +minus + + align:start position:0% +minus + + + align:start position:0% +minus +sign and dividing by Delta + + align:start position:0% +sign and dividing by Delta + + + align:start position:0% +sign and dividing by Delta +x^2 and that's so it was G Prime well + + align:start position:0% +x^2 and that's so it was G Prime well + + + align:start position:0% +x^2 and that's so it was G Prime well +let's just write it so I have G I'm now + + align:start position:0% +let's just write it so I have G I'm now + + + align:start position:0% +let's just write it so I have G I'm now +going to copy what i g Prime was the + + align:start position:0% +going to copy what i g Prime was the + + + align:start position:0% +going to copy what i g Prime was the +minus sign time the c^ 2 time this 4 sin + + align:start position:0% +minus sign time the c^ 2 time this 4 sin + + + align:start position:0% +minus sign time the c^ 2 time this 4 sin +SAR of K Delta X on 2 divided by Delta + + align:start position:0% +SAR of K Delta X on 2 divided by Delta + + + align:start position:0% +SAR of K Delta X on 2 divided by Delta +x^2 well maybe I'll put the Delta X2 + + align:start position:0% +x^2 well maybe I'll put the Delta X2 + + + align:start position:0% +x^2 well maybe I'll put the Delta X2 +over over there where it kind of + + align:start position:0% + + + + align:start position:0% + +belongs + + align:start position:0% +belongs + + + align:start position:0% +belongs +okay times G always forgetting + + align:start position:0% +okay times G always forgetting + + + align:start position:0% +okay times G always forgetting +G + + align:start position:0% + + + + align:start position:0% + +okay so we we're just following the + + align:start position:0% +okay so we we're just following the + + + align:start position:0% +okay so we we're just following the +golden way here of plugging in an + + align:start position:0% +golden way here of plugging in an + + + align:start position:0% +golden way here of plugging in an +exponential and seeing what happens and + + align:start position:0% +exponential and seeing what happens and + + + align:start position:0% +exponential and seeing what happens and +what happens is pretty nice the solution + + align:start position:0% +what happens is pretty nice the solution + + + align:start position:0% +what happens is pretty nice the solution +we can we now know what the solutions + + align:start position:0% +we can we now know what the solutions + + + align:start position:0% +we can we now know what the solutions +are there'll be two solutions it's a + + align:start position:0% +are there'll be two solutions it's a + + + align:start position:0% +are there'll be two solutions it's a +linear problem so the solutions will be + + align:start position:0% +linear problem so the solutions will be + + + align:start position:0% +linear problem so the solutions will be +exponential in t so the solution the the + + align:start position:0% +exponential in t so the solution the the + + + align:start position:0% +exponential in t so the solution the the +the solutions will have a plus or minus + + align:start position:0% +the solutions will have a plus or minus + + + align:start position:0% +the solutions will have a plus or minus +I because it's a minus sign so G can I + + align:start position:0% +I because it's a minus sign so G can I + + + align:start position:0% +I because it's a minus sign so G can I +write it this way G of the solution to + + align:start position:0% +write it this way G of the solution to + + + align:start position:0% +write it this way G of the solution to +this or the two the two exponential + + align:start position:0% +this or the two the two exponential + + + align:start position:0% +this or the two the two exponential +Solutions will be + + align:start position:0% +Solutions will be + + + align:start position:0% +Solutions will be +e to the plus or minus and I'm going to + + align:start position:0% +e to the plus or minus and I'm going to + + + align:start position:0% +e to the plus or minus and I'm going to +take the square root I * C * the square + + align:start position:0% +take the square root I * C * the square + + + align:start position:0% +take the square root I * C * the square +root of this well actually not that's + + align:start position:0% +root of this well actually not that's + + + align:start position:0% +root of this well actually not that's +not so hard two that was our Point + + align:start position:0% +not so hard two that was our Point + + + align:start position:0% +not so hard two that was our Point +wasn't it sorry I forgot about that sin + + align:start position:0% +wasn't it sorry I forgot about that sin + + + align:start position:0% +wasn't it sorry I forgot about that sin +K Delta X over + + align:start position:0% +K Delta X over + + + align:start position:0% +K Delta X over +2 / deltax and look here here's + + align:start position:0% +2 / deltax and look here here's + + + align:start position:0% +2 / deltax and look here here's +something nice bring the two down there + + align:start position:0% +something nice bring the two down there + + + align:start position:0% +something nice bring the two down there +what it make it 1/2 in the denominator + + align:start position:0% +what it make it 1/2 in the denominator + + + align:start position:0% +what it make it 1/2 in the denominator +do you see what what this expression + + align:start position:0% +do you see what what this expression + + + align:start position:0% +do you see what what this expression +is actually do you know its + + align:start position:0% +is actually do you know its + + + align:start position:0% +is actually do you know its +name you know it's the sync function + + align:start position:0% +name you know it's the sync function + + + align:start position:0% +name you know it's the sync function +it's the sync function right and for + + align:start position:0% +it's the sync function right and for + + + align:start position:0% +it's the sync function right and for +very small Delta X oh times + + align:start position:0% + + + + align:start position:0% + +T right it it's just we just have an + + align:start position:0% +T right it it's just we just have an + + + align:start position:0% +T right it it's just we just have an +exponential of course we do this was a + + align:start position:0% +exponential of course we do this was a + + + align:start position:0% +exponential of course we do this was a +constant coefficient problem in t so and + + align:start position:0% +constant coefficient problem in t so and + + + align:start position:0% +constant coefficient problem in t so and +of second order so I had two + + align:start position:0% +of second order so I had two + + + align:start position:0% +of second order so I had two +exponentials and I just took the square + + align:start position:0% +exponentials and I just took the square + + + align:start position:0% +exponentials and I just took the square +root of that coefficient put it there + + align:start position:0% +root of that coefficient put it there + + + align:start position:0% +root of that coefficient put it there +times T absolutely + + align:start position:0% +times T absolutely + + + align:start position:0% +times T absolutely +straightforward and now so everything is + + align:start position:0% +straightforward and now so everything is + + + align:start position:0% +straightforward and now so everything is +this this quantity is the is the key one + + align:start position:0% +this this quantity is the is the key one + + + align:start position:0% +this this quantity is the is the key one +and this is the quantity + + align:start position:0% +and this is the quantity + + + align:start position:0% +and this is the quantity +which for small + + align:start position:0% +which for small + + + align:start position:0% +which for small +K or small Delta + + align:start position:0% +K or small Delta + + + align:start position:0% +K or small Delta +X is approximately + + align:start position:0% +X is approximately + + + align:start position:0% +X is approximately +what so so if if if K and Delta X are + + align:start position:0% +what so so if if if K and Delta X are + + + align:start position:0% +what so so if if if K and Delta X are +small or if even just Delta X is small + + align:start position:0% +small or if even just Delta X is small + + + align:start position:0% +small or if even just Delta X is small +what does this sync function look like + + align:start position:0% +what does this sync function look like + + + align:start position:0% +what does this sync function look like +what is that ratio + + align:start position:0% + + + + align:start position:0% + +approximately when K is + + align:start position:0% +approximately when K is + + + align:start position:0% +approximately when K is +small well what does the s of theta look + + align:start position:0% +small well what does the s of theta look + + + align:start position:0% +small well what does the s of theta look +like when Theta is a small + + align:start position:0% +like when Theta is a small + + + align:start position:0% +like when Theta is a small +angle looks like Theta right + + align:start position:0% +angle looks like Theta right + + + align:start position:0% +angle looks like Theta right +sin Theta is about + + align:start position:0% +sin Theta is about + + + align:start position:0% +sin Theta is about +Theta so this thing is about K Delta x + + align:start position:0% +Theta so this thing is about K Delta x + + + align:start position:0% +Theta so this thing is about K Delta x +over2 / Delta it's K so it's + + align:start position:0% +over2 / Delta it's K so it's + + + align:start position:0% +over2 / Delta it's K so it's +approximately + + align:start position:0% +approximately + + + align:start position:0% +approximately +k for + + align:start position:0% + + + + align:start position:0% + +small Delta X let's say Delta X is small + + align:start position:0% +small Delta X let's say Delta X is small + + + align:start position:0% +small Delta X let's say Delta X is small +that's a right that's the key thing to + + align:start position:0% +that's a right that's the key thing to + + + align:start position:0% +that's a right that's the key thing to +know about the sync + + align:start position:0% +know about the sync + + + align:start position:0% +know about the sync +function that it it begins by + + align:start position:0% +function that it it begins by + + + align:start position:0% +function that it it begins by +approximating the sign function but then + + align:start position:0% +approximating the sign function but then + + + align:start position:0% +approximating the sign function but then +of course when K Delta X gets large it + + align:start position:0% +of course when K Delta X gets large it + + + align:start position:0% +of course when K Delta X gets large it +wanders away it's not linear in K see it + + align:start position:0% +wanders away it's not linear in K see it + + + align:start position:0% +wanders away it's not linear in K see it +starts out practically linear in K and + + align:start position:0% +starts out practically linear in K and + + + align:start position:0% +starts out practically linear in K and +that K is exactly the right K that's the + + align:start position:0% +that K is exactly the right K that's the + + + align:start position:0% +that K is exactly the right K that's the +right Factor that's the K + + align:start position:0% + + + + align:start position:0% + +here but in the differential equation it + + align:start position:0% +here but in the differential equation it + + + align:start position:0% +here but in the differential equation it +stayed K and in the difference equation + + align:start position:0% +stayed K and in the difference equation + + + align:start position:0% +stayed K and in the difference equation +as k for K Delta X moving moving moving + + align:start position:0% +as k for K Delta X moving moving moving + + + align:start position:0% +as k for K Delta X moving moving moving +away it it changes and + + align:start position:0% +away it it changes and + + + align:start position:0% +away it it changes and +uh that's why well of course that's the + + align:start position:0% +uh that's why well of course that's the + + + align:start position:0% +uh that's why well of course that's the +source of the + + align:start position:0% +source of the + + + align:start position:0% +source of the +error and we're seeing now why the + + align:start position:0% +error and we're seeing now why the + + + align:start position:0% +error and we're seeing now why the +method is probably second order accuracy + + align:start position:0% +method is probably second order accuracy + + + align:start position:0% +method is probably second order accuracy +yeah we we know that these second + + align:start position:0% +yeah we we know that these second + + + align:start position:0% +yeah we we know that these second +differences are second give second order + + align:start position:0% +differences are second give second order + + + align:start position:0% +differences are second give second order +accuracy this would be if I looked at + + align:start position:0% +accuracy this would be if I looked at + + + align:start position:0% +accuracy this would be if I looked at +the next term what's the next term in + + align:start position:0% +the next term what's the next term in + + + align:start position:0% +the next term what's the next term in +sin Theta sin Theta starts out Theta and + + align:start position:0% +sin Theta sin Theta starts out Theta and + + + align:start position:0% +sin Theta sin Theta starts out Theta and +what's the what's the term after + + align:start position:0% + + + + align:start position:0% + +that everybody's tailor series or + + align:start position:0% +that everybody's tailor series or + + + align:start position:0% +that everybody's tailor series or +huming Theta Cub it's a Theta Cub term + + align:start position:0% +huming Theta Cub it's a Theta Cub term + + + align:start position:0% +huming Theta Cub it's a Theta Cub term +ex exactly it's a minus Theta Cube over + + align:start position:0% +ex exactly it's a minus Theta Cube over + + + align:start position:0% +ex exactly it's a minus Theta Cube over +6 3 factorial but it's a Theta Cub term + + align:start position:0% +6 3 factorial but it's a Theta Cub term + + + align:start position:0% +6 3 factorial but it's a Theta Cub term +and and so the Theta gave us the right + + align:start position:0% +and and so the Theta gave us the right + + + align:start position:0% +and and so the Theta gave us the right +thing and then two more powers of theta + + align:start position:0% +thing and then two more powers of theta + + + align:start position:0% +thing and then two more powers of theta +will give us a second order error right + + align:start position:0% +will give us a second order error right + + + align:start position:0% +will give us a second order error right +okay okay I better move since so that's + + align:start position:0% +okay okay I better move since so that's + + + align:start position:0% +okay okay I better move since so that's +the story for semidiscrete + + align:start position:0% +the story for semidiscrete + + + align:start position:0% +the story for semidiscrete +semidiscrete produced a pure + + align:start position:0% +semidiscrete produced a pure + + + align:start position:0% +semidiscrete produced a pure +exponential but with + + align:start position:0% +exponential but with + + + align:start position:0% +exponential but with +u with a phase Factor you could + + align:start position:0% +u with a phase Factor you could + + + align:start position:0% +u with a phase Factor you could +say that that wasn't linear in K where + + align:start position:0% +say that that wasn't linear in K where + + + align:start position:0% +say that that wasn't linear in K where +the real one was okay + + align:start position:0% +the real one was okay + + + align:start position:0% +the real one was okay +now what about let me move up to that + + align:start position:0% +now what about let me move up to that + + + align:start position:0% +now what about let me move up to that +board + + align:start position:0% +board + + + align:start position:0% +board +above + + align:start position:0% +above + + + align:start position:0% +above +where now we're going to have we have it + + align:start position:0% +where now we're going to have we have it + + + align:start position:0% +where now we're going to have we have it +it's discrete in time as well so we're + + align:start position:0% +it's discrete in time as well so we're + + + align:start position:0% +it's discrete in time as well so we're +going to have single + + align:start position:0% +going to have single + + + align:start position:0% +going to have single +steps well what's going to be the + + align:start position:0% + + + + align:start position:0% + +difference again I'm going to try you + + align:start position:0% +difference again I'm going to try you + + + align:start position:0% +difference again I'm going to try you +know I only have one idea here + + align:start position:0% +know I only have one idea here + + + align:start position:0% +know I only have one idea here +ujn will be some G + + align:start position:0% +ujn will be some G + + + align:start position:0% +ujn will be some G +some growth factor times e to the + + align:start position:0% +some growth factor times e to the + + + align:start position:0% +some growth factor times e to the +i j k deltax just same I'm going to try + + align:start position:0% +i j k deltax just same I'm going to try + + + align:start position:0% +i j k deltax just same I'm going to try +an e to the I + + align:start position:0% +an e to the I + + + align:start position:0% +an e to the I +KX and in the space variable it will be + + align:start position:0% +KX and in the space variable it will be + + + align:start position:0% +KX and in the space variable it will be +G and oh and after n steps it'll be GN + + align:start position:0% +G and oh and after n steps it'll be GN + + + align:start position:0% +G and oh and after n steps it'll be GN +times so this is the discrete this is + + align:start position:0% +times so this is the discrete this is + + + align:start position:0% +times so this is the discrete this is +right this is the + + align:start position:0% +right this is the + + + align:start position:0% +right this is the +uh anzats to use a fancy word this is + + align:start position:0% +uh anzats to use a fancy word this is + + + align:start position:0% +uh anzats to use a fancy word this is +what you plug + + align:start position:0% + + + + align:start position:0% + +in a little crazy to use the word anzats + + align:start position:0% +in a little crazy to use the word anzats + + + align:start position:0% +in a little crazy to use the word anzats +which sounds fancy and the word plug + + align:start position:0% +which sounds fancy and the word plug + + + align:start position:0% +which sounds fancy and the word plug +Which is far from fancy I should say + + align:start position:0% +Which is far from fancy I should say + + + align:start position:0% +Which is far from fancy I should say +substitute of course okay so substitute + + align:start position:0% +substitute of course okay so substitute + + + align:start position:0% +substitute of course okay so substitute +it in all right do we know what the + + align:start position:0% +it in all right do we know what the + + + align:start position:0% +it in all right do we know what the +process is going to do when I plug it in + + align:start position:0% +process is going to do when I plug it in + + + align:start position:0% +process is going to do when I plug it in +sorry substitute it in on the left we + + align:start position:0% +sorry substitute it in on the left we + + + align:start position:0% +sorry substitute it in on the left we +get and I'm going to cancel I'm going to + + align:start position:0% +get and I'm going to cancel I'm going to + + + align:start position:0% +get and I'm going to cancel I'm going to +cancel this + + align:start position:0% +cancel this + + + align:start position:0% +cancel this +from every + + align:start position:0% +from every + + + align:start position:0% +from every +term so all I'm interested in is the + + align:start position:0% +term so all I'm interested in is the + + + align:start position:0% +term so all I'm interested in is the +well maybe I'll cancel G to the N minus + + align:start position:0% +well maybe I'll cancel G to the N minus + + + align:start position:0% +well maybe I'll cancel G to the N minus +one so let me write down what I get this + + align:start position:0% +one so let me write down what I get this + + + align:start position:0% +one so let me write down what I get this +is going to give me in the time + + align:start position:0% +is going to give me in the time + + + align:start position:0% +is going to give me in the time +Direction I'll have a g s minus a 2 G + + + align:start position:0% +Direction I'll have a g s minus a 2 G + + + + align:start position:0% +Direction I'll have a g s minus a 2 G + +a 1 over Delta t^ + + align:start position:0% +a 1 over Delta t^ + + + align:start position:0% +a 1 over Delta t^ +2 and in the space Direction which is at + + align:start position:0% +2 and in the space Direction which is at + + + align:start position:0% +2 and in the space Direction which is at +the centered time so it's going to + + align:start position:0% +the centered time so it's going to + + + align:start position:0% +the centered time so it's going to +multiply a g it's going to be my same my + + align:start position:0% +multiply a g it's going to be my same my + + + align:start position:0% +multiply a g it's going to be my same my +very same thing I could maybe give it a + + align:start position:0% +very same thing I could maybe give it a + + + align:start position:0% +very same thing I could maybe give it a +name here I I I don't know whether + + align:start position:0% +name here I I I don't know whether + + + align:start position:0% +name here I I I don't know whether +should I give it a name or I know what + + align:start position:0% +should I give it a name or I know what + + + align:start position:0% +should I give it a name or I know what +it is anyway because it's the same thing + + align:start position:0% +it is anyway because it's the same thing + + + align:start position:0% +it is anyway because it's the same thing +that I had in the in the semidiscrete + + align:start position:0% +that I had in the in the semidiscrete + + + align:start position:0% +that I had in the in the semidiscrete +method it's this uh uh yeah let let's + + align:start position:0% +method it's this uh uh yeah let let's + + + align:start position:0% +method it's this uh uh yeah let let's +see what it looked like at this point it + + align:start position:0% +see what it looked like at this point it + + + align:start position:0% +see what it looked like at this point it +was um yeah there so there's a c oh look + + align:start position:0% +was um yeah there so there's a c oh look + + + align:start position:0% +was um yeah there so there's a c oh look +look let's let's do one thing let's let + + align:start position:0% +look let's let's do one thing let's let + + + align:start position:0% +look let's let's do one thing let's let +me get this Delta t^2 up there times the + + align:start position:0% +me get this Delta t^2 up there times the + + + align:start position:0% +me get this Delta t^2 up there times the +c^2 / the Delta x^2 let me just clean up + + align:start position:0% +c^2 / the Delta x^2 let me just clean up + + + align:start position:0% +c^2 / the Delta x^2 let me just clean up +those constants + + align:start position:0% +those constants + + + align:start position:0% +those constants +so so that when I multiply up by the + + align:start position:0% +so so that when I multiply up by the + + + align:start position:0% +so so that when I multiply up by the +Delta t^ 2 times the c^ 2 / the Delta + + align:start position:0% +Delta t^ 2 times the c^ 2 / the Delta + + + align:start position:0% +Delta t^ 2 times the c^ 2 / the Delta +x^2 what's + + align:start position:0% +x^2 what's + + + align:start position:0% +x^2 what's +that c delta T over Delta x^2 is my old + + align:start position:0% +that c delta T over Delta x^2 is my old + + + align:start position:0% +that c delta T over Delta x^2 is my old +ratio the Quant number r squ + + align:start position:0% +ratio the Quant number r squ + + + align:start position:0% +ratio the Quant number r squ +and then it's + + align:start position:0% +and then it's + + + align:start position:0% +and then it's +this time G so this will all be just + + align:start position:0% +this time G so this will all be just + + + align:start position:0% +this time G so this will all be just +exactly the same and that's what I + + align:start position:0% +exactly the same and that's what I + + + align:start position:0% +exactly the same and that's what I +simplified here but well let me just + + align:start position:0% +simplified here but well let me just + + + align:start position:0% +simplified here but well let me just +leave it + + align:start position:0% +leave it + + + align:start position:0% +leave it +as uh with a minus let me remember that + + align:start position:0% +as uh with a minus let me remember that + + + align:start position:0% +as uh with a minus let me remember that +I did take a minus so that I could write + + align:start position:0% +I did take a minus so that I could write + + + align:start position:0% +I did take a minus so that I could write +it as 2 minus 2 cosine of K Delta X time + + align:start position:0% +it as 2 minus 2 cosine of K Delta X time + + + align:start position:0% +it as 2 minus 2 cosine of K Delta X time +G is that + + align:start position:0% + + + + align:start position:0% + +I really think I have kept track of + + align:start position:0% +I really think I have kept track of + + + align:start position:0% +I really think I have kept track of +everything here the r squar coming from + + align:start position:0% +everything here the r squar coming from + + + align:start position:0% +everything here the r squar coming from +all this stuff the + + align:start position:0% +all this stuff the + + + align:start position:0% +all this stuff the +minus two coming here and the plus two + + align:start position:0% +minus two coming here and the plus two + + + align:start position:0% +minus two coming here and the plus two +cosine coming from there you okay with + + align:start position:0% + + + + align:start position:0% + +that but there's one new ingredient here + + align:start position:0% +that but there's one new ingredient here + + + align:start position:0% +that but there's one new ingredient here +and again G to the N I cancelled G to + + align:start position:0% +and again G to the N I cancelled G to + + + align:start position:0% +and again G to the N I cancelled G to +the n minus1 time this from every + + align:start position:0% +the n minus1 time this from every + + + align:start position:0% +the n minus1 time this from every +term okay so the new ingredient that we + + align:start position:0% +term okay so the new ingredient that we + + + align:start position:0% +term okay so the new ingredient that we +just have five minutes to deal + + align:start position:0% +just have five minutes to deal + + + align:start position:0% +just have five minutes to deal +with is the fact that we have second we + + align:start position:0% +with is the fact that we have second we + + + align:start position:0% +with is the fact that we have second we +have G squar is showed + + align:start position:0% +have G squar is showed + + + align:start position:0% +have G squar is showed +up so why did g squ show up because it's + + align:start position:0% +up so why did g squ show up because it's + + + align:start position:0% +up so why did g squ show up because it's +a two it's a multi-step + + align:start position:0% + + + + align:start position:0% + +method and therefore I've got two G's of + + align:start position:0% +method and therefore I've got two G's of + + + align:start position:0% +method and therefore I've got two G's of +course I had two G's in all these other + + align:start position:0% +course I had two G's in all these other + + + align:start position:0% +course I had two G's in all these other +cases because I had second derivatives + + align:start position:0% +cases because I had second derivatives + + + align:start position:0% +cases because I had second derivatives +and now I have second difference so I + + align:start position:0% +and now I have second difference so I + + + align:start position:0% +and now I have second difference so I +have two G's so I have to solve for G + + align:start position:0% +have two G's so I have to solve for G + + + align:start position:0% +have two G's so I have to solve for G +and and what is stability going to + + align:start position:0% +and and what is stability going to + + + align:start position:0% +and and what is stability going to +depend on stability is going to be + + align:start position:0% +depend on stability is going to be + + + align:start position:0% +depend on stability is going to be +whether + + align:start position:0% +whether + + + align:start position:0% +whether +G both G's because there two of them now + + align:start position:0% +G both G's because there two of them now + + + align:start position:0% +G both G's because there two of them now +are less or equal one that that's what I + + align:start position:0% +are less or equal one that that's what I + + + align:start position:0% +are less or equal one that that's what I +have to check and and that's the + + align:start position:0% + + + + align:start position:0% + +equation and what do we + + align:start position:0% +equation and what do we + + + align:start position:0% +equation and what do we +figure we figure that if R is pretty big + + align:start position:0% +figure we figure that if R is pretty big + + + align:start position:0% +figure we figure that if R is pretty big +if R is big no way if R is Big the Quant + + align:start position:0% +if R is big no way if R is Big the Quant + + + align:start position:0% +if R is big no way if R is Big the Quant +test will + + align:start position:0% +test will + + + align:start position:0% +test will +fail and stability will fail but if R is + + align:start position:0% +fail and stability will fail but if R is + + + align:start position:0% +fail and stability will fail but if R is +small then I expect I have a right to + + align:start position:0% +small then I expect I have a right to + + + align:start position:0% +small then I expect I have a right to +hope for stability so it's going to be + + align:start position:0% +hope for stability so it's going to be + + + align:start position:0% +hope for stability so it's going to be +the size of R okay so I just have to + + align:start position:0% +the size of R okay so I just have to + + + align:start position:0% +the size of R okay so I just have to +I've got this quadratic equation I'm + + align:start position:0% +I've got this quadratic equation I'm + + + align:start position:0% +I've got this quadratic equation I'm +going to bring this thing over here I'm + + align:start position:0% +going to bring this thing over here I'm + + + align:start position:0% +going to bring this thing over here I'm +going to write this as g^ 2 minus 2 a g + + align:start position:0% +going to write this as g^ 2 minus 2 a g + + + align:start position:0% +going to write this as g^ 2 minus 2 a g ++ 1 = Z where a is this quantity so I + + align:start position:0% ++ 1 = Z where a is this quantity so I + + + align:start position:0% ++ 1 = Z where a is this quantity so I +minus 2 a so a is a one from there and + + align:start position:0% +minus 2 a so a is a one from there and + + + align:start position:0% +minus 2 a so a is a one from there and +when I bring this + + align:start position:0% +when I bring this + + + align:start position:0% +when I bring this +over to the other side it's going to be + + align:start position:0% +over to the other side it's going to be + + + align:start position:0% +over to the other side it's going to be +a plus r + + align:start position:0% +a plus r + + + align:start position:0% +a plus r +2 factoring out the notice the two is + + align:start position:0% +2 factoring out the notice the two is + + + align:start position:0% +2 factoring out the notice the two is +everywhere so I put the two here the a + + align:start position:0% +everywhere so I put the two here the a + + + align:start position:0% +everywhere so I put the two here the a +is going to the a comes from the one + + align:start position:0% +is going to the a comes from the one + + + align:start position:0% +is going to the a comes from the one +there and from this time the R 2 1 + r + + align:start position:0% +there and from this time the R 2 1 + r + + + align:start position:0% +there and from this time the R 2 1 + r +- R 2 cos K Delta + + align:start position:0% + + + + align:start position:0% + +X I'm just doing + + align:start position:0% + + + + align:start position:0% + +algebra and it's coming out nicely it's + + align:start position:0% +algebra and it's coming out nicely it's + + + align:start position:0% +algebra and it's coming out nicely it's +coming out to a nice equation here with + + align:start position:0% +coming out to a nice equation here with + + + align:start position:0% +coming out to a nice equation here with +a slightly messy expression for a but if + + align:start position:0% +a slightly messy expression for a but if + + + align:start position:0% +a slightly messy expression for a but if +I now that I've named this quantity a I + + align:start position:0% +I now that I've named this quantity a I + + + align:start position:0% +I now that I've named this quantity a I +can can solve + + align:start position:0% +can can solve + + + align:start position:0% +can can solve +this so what's the solution I remember + + align:start position:0% +this so what's the solution I remember + + + align:start position:0% +this so what's the solution I remember +the quadratic formula and I get G + + align:start position:0% +the quadratic formula and I get G + + + align:start position:0% +the quadratic formula and I get G +as one I think plus or minus the square + + align:start position:0% +as one I think plus or minus the square + + + align:start position:0% +as one I think plus or minus the square +root + + align:start position:0% +root + + + align:start position:0% +root +of 1 - A + + align:start position:0% +of 1 - A + + + align:start position:0% +of 1 - A +2 that's + + align:start position:0% + + + + align:start position:0% + +G oh maybe this is an a probably is I + + align:start position:0% +G oh maybe this is an a probably is I + + + align:start position:0% +G oh maybe this is an a probably is I +guess the quadratic + + align:start position:0% + + + + align:start position:0% + +equation takes a little memorizing but I + + align:start position:0% +equation takes a little memorizing but I + + + align:start position:0% +equation takes a little memorizing but I +guess the first point is that that + + align:start position:0% +guess the first point is that that + + + align:start position:0% +guess the first point is that that +coefficient shows up there and then the + + align:start position:0% +coefficient shows up there and then the + + + align:start position:0% +coefficient shows up there and then the +square root that we know + + align:start position:0% +square root that we know + + + align:start position:0% +square root that we know +okay so what's + + align:start position:0% + + + + align:start position:0% + +up again none of this is deep I'm just + + align:start position:0% +up again none of this is deep I'm just + + + align:start position:0% +up again none of this is deep I'm just +following + + align:start position:0% +following + + + align:start position:0% +following +my one one way path + + align:start position:0% +my one one way path + + + align:start position:0% +my one one way path +check stability check the size of G get + + align:start position:0% +check stability check the size of G get + + + align:start position:0% +check stability check the size of G get +an equation for G get a formula for G + + align:start position:0% +an equation for G get a formula for G + + + align:start position:0% +an equation for G get a formula for G +and look at it okay so a is + + align:start position:0% +and look at it okay so a is + + + align:start position:0% +and look at it okay so a is +some positive number and and the key is + + align:start position:0% +some positive number and and the key is + + + align:start position:0% +some positive number and and the key is +going to be whether a is bigger than one + + align:start position:0% +going to be whether a is bigger than one + + + align:start position:0% +going to be whether a is bigger than one +or smaller than one if a + + align:start position:0% + + + + align:start position:0% + +is is that right 1 - A 2 or should that + + align:start position:0% +is is that right 1 - A 2 or should that + + + align:start position:0% +is is that right 1 - A 2 or should that +be a^ 2 - + + align:start position:0% +be a^ 2 - + + + align:start position:0% +be a^ 2 - +1 is it a 2us + + align:start position:0% +1 is it a 2us + + + align:start position:0% +1 is it a 2us +one yeah professors are not responsible + + align:start position:0% +one yeah professors are not responsible + + + align:start position:0% +one yeah professors are not responsible +for the quadratic formula + + align:start position:0% +for the quadratic formula + + + align:start position:0% +for the quadratic formula +because we proved that we could do it in + + align:start position:0% +because we proved that we could do it in + + + align:start position:0% +because we proved that we could do it in +third grade and that lost it absence I + + align:start position:0% +third grade and that lost it absence I + + + align:start position:0% +third grade and that lost it absence I +guess it's that right is that + + align:start position:0% +guess it's that right is that + + + align:start position:0% +guess it's that right is that +right yeah because look here here's the + + align:start position:0% +right yeah because look here here's the + + + align:start position:0% +right yeah because look here here's the +story suppose a is bigger than + + align:start position:0% +story suppose a is bigger than + + + align:start position:0% +story suppose a is bigger than +one suppose I'm really looking at the + + align:start position:0% +one suppose I'm really looking at the + + + align:start position:0% +one suppose I'm really looking at the +roots of this equation and and notice by + + align:start position:0% +roots of this equation and and notice by + + + align:start position:0% +roots of this equation and and notice by +the way the roots of that equation + + align:start position:0% +the way the roots of that equation + + + align:start position:0% +the way the roots of that equation +multiply to give one so I'm I'm pretty + + align:start position:0% +multiply to give one so I'm I'm pretty + + + align:start position:0% +multiply to give one so I'm I'm pretty +I'm on the edge here either both Roots + + align:start position:0% +I'm on the edge here either both Roots + + + align:start position:0% +I'm on the edge here either both Roots +have size one or one of those roots is + + align:start position:0% +have size one or one of those roots is + + + align:start position:0% +have size one or one of those roots is +too big and the test is going to be is a + + align:start position:0% +too big and the test is going to be is a + + + align:start position:0% +too big and the test is going to be is a +greater than one a greater than one will + + align:start position:0% +greater than one a greater than one will + + + align:start position:0% +greater than one a greater than one will +be + + align:start position:0% + + + + align:start position:0% + +unstable and a less than one + + align:start position:0% +unstable and a less than one + + + align:start position:0% +unstable and a less than one +will be stable + + align:start position:0% +will be stable + + + align:start position:0% +will be stable +and I'll I'll connect a less than one to + + align:start position:0% +and I'll I'll connect a less than one to + + + align:start position:0% +and I'll I'll connect a less than one to +R less than + + align:start position:0% +R less than + + + align:start position:0% +R less than +one that will give me R less than one + + align:start position:0% +one that will give me R less than one + + + align:start position:0% +one that will give me R less than one +all right now i' I've given away the + + align:start position:0% +all right now i' I've given away the + + + align:start position:0% +all right now i' I've given away the +result because we time is pressing let + + align:start position:0% +result because we time is pressing let + + + align:start position:0% +result because we time is pressing let +me just take the take the remaining time + + align:start position:0% +me just take the take the remaining time + + + align:start position:0% +me just take the take the remaining time +to see this suppose a is bigger than + + align:start position:0% +to see this suppose a is bigger than + + + align:start position:0% +to see this suppose a is bigger than +one I'm just looking at the roots of + + align:start position:0% +one I'm just looking at the roots of + + + align:start position:0% +one I'm just looking at the roots of +this equation equation and here they are + + align:start position:0% +this equation equation and here they are + + + align:start position:0% +this equation equation and here they are +if a is bigger than + + align:start position:0% +if a is bigger than + + + align:start position:0% +if a is bigger than +one like two I have 2+ > 3 I'm way out + + align:start position:0% +one like two I have 2+ > 3 I'm way out + + + align:start position:0% +one like two I have 2+ > 3 I'm way out +right I'm bigger than one no question + + align:start position:0% +right I'm bigger than one no question + + + align:start position:0% +right I'm bigger than one no question +suppose a is less than + + align:start position:0% +suppose a is less than + + + align:start position:0% +suppose a is less than +one suppose a is a + + align:start position:0% +one suppose a is a + + + align:start position:0% +one suppose a is a +half then I have a half plus or minus + + align:start position:0% +half then I have a half plus or minus + + + align:start position:0% +half then I have a half plus or minus +the square root of + + align:start position:0% +the square root of + + + align:start position:0% +the square root of +what what's up here if a is smaller than + + align:start position:0% +what what's up here if a is smaller than + + + align:start position:0% +what what's up here if a is smaller than +one this is negative + + align:start position:0% + + + + align:start position:0% + +and if it's negative its square root is + + align:start position:0% +and if it's negative its square root is + + + align:start position:0% +and if it's negative its square root is +imaginary so this is good I + + align:start position:0% +imaginary so this is good I + + + align:start position:0% +imaginary so this is good I +have a real part and then an imaginary + + align:start position:0% +have a real part and then an imaginary + + + align:start position:0% +have a real part and then an imaginary +part and then on some magic little bit + + align:start position:0% +part and then on some magic little bit + + + align:start position:0% +part and then on some magic little bit +of board I'm going to add their squares + + align:start position:0% +of board I'm going to add their squares + + + align:start position:0% +of board I'm going to add their squares +so I just want to take the real part + + align:start position:0% +so I just want to take the real part + + + align:start position:0% +so I just want to take the real part +squared and the imaginary part + + align:start position:0% +squared and the imaginary part + + + align:start position:0% +squared and the imaginary part +squared now the imaginary part is going + + align:start position:0% +squared now the imaginary part is going + + + align:start position:0% +squared now the imaginary part is going +to be 1 - A squ + + align:start position:0% +to be 1 - A squ + + + align:start position:0% +to be 1 - A squ +because when I bring out an + + align:start position:0% +because when I bring out an + + + align:start position:0% +because when I bring out an +I then I have a 1 - A S there and when I + + align:start position:0% +I then I have a 1 - A S there and when I + + + align:start position:0% +I then I have a 1 - A S there and when I +add them I get + + align:start position:0% +add them I get + + + align:start position:0% +add them I get +one let me just say again what I did I + + align:start position:0% +one let me just say again what I did I + + + align:start position:0% +one let me just say again what I did I +just figured out what is absolute value + + align:start position:0% +just figured out what is absolute value + + + align:start position:0% +just figured out what is absolute value +of g^ s as real part squared and + + align:start position:0% +of g^ s as real part squared and + + + align:start position:0% +of g^ s as real part squared and +imaginary part squared and I get the + + align:start position:0% +imaginary part squared and I get the + + + align:start position:0% +imaginary part squared and I get the +answer one so the conclusion is the + + align:start position:0% +answer one so the conclusion is the + + + align:start position:0% +answer one so the conclusion is the +roots are stable when a is below one + + align:start position:0% +roots are stable when a is below one + + + align:start position:0% +roots are stable when a is below one +and I have instability when a is above + + align:start position:0% +and I have instability when a is above + + + align:start position:0% +and I have instability when a is above +one and then if I track that down that + + align:start position:0% +one and then if I track that down that + + + align:start position:0% +one and then if I track that down that +reduces to the tests it just happens to + + align:start position:0% +reduces to the tests it just happens to + + + align:start position:0% +reduces to the tests it just happens to +be the same test on R whether R is below + + align:start position:0% +be the same test on R whether R is below + + + align:start position:0% +be the same test on R whether R is below +one which is the kurant Frick's ly + + align:start position:0% +one which is the kurant Frick's ly + + + align:start position:0% +one which is the kurant Frick's ly +condition that I'm staying inside the + + align:start position:0% +condition that I'm staying inside the + + + align:start position:0% +condition that I'm staying inside the +characteristics or R is bigger than one + + align:start position:0% +characteristics or R is bigger than one + + + align:start position:0% +characteristics or R is bigger than one +and I'm taking a delta T that isn't + + align:start position:0% +and I'm taking a delta T that isn't + + + align:start position:0% +and I'm taking a delta T that isn't +isn't stable okay so that I'm sorry to + + align:start position:0% +isn't stable okay so that I'm sorry to + + + align:start position:0% +isn't stable okay so that I'm sorry to +go slightly over the time thanks for + + align:start position:0% +go slightly over the time thanks for + + + align:start position:0% +go slightly over the time thanks for +staying with me I'll begin next time + + align:start position:0% +staying with me I'll begin next time + + + align:start position:0% +staying with me I'll begin next time +with this staggered grid that won't take + + align:start position:0% +with this staggered grid that won't take + + + align:start position:0% +with this staggered grid that won't take +the whole lecture but it's worth knowing + + align:start position:0% +the whole lecture but it's worth knowing + + + align:start position:0% +the whole lecture but it's worth knowing +because we see staggered grids in many + + align:start position:0% +because we see staggered grids in many + + + align:start position:0% +because we see staggered grids in many +of the best + + align:start position:0% +of the best + + + align:start position:0% +of the best +methods okay thanks have a good weekend + + align:start position:0% +methods okay thanks have a good weekend + + + align:start position:0% +methods okay thanks have a good weekend +and I guess it's Tuesday rather than + + align:start position:0% +and I guess it's Tuesday rather than + + + align:start position:0% +and I guess it's Tuesday rather than +Monday that I see you next + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +it with the like + + align:start position:0% + + + + align:start position:0% + +say that I'm happy \ No newline at end of file diff --git a/13r9QY6cmjc.txt b/13r9QY6cmjc.txt new file mode 100644 index 0000000000000000000000000000000000000000..02b9ddb5676a959f60212d09f862e4e7412c8052 --- /dev/null +++ b/13r9QY6cmjc.txt @@ -0,0 +1,6555 @@ +align:start position:0% + +okay so we start this is the second + + align:start position:0% +okay so we start this is the second + + + align:start position:0% +okay so we start this is the second +lecture on eigenvalues so the first + + align:start position:0% +lecture on eigenvalues so the first + + + align:start position:0% +lecture on eigenvalues so the first +lecture was that reached the key + + align:start position:0% +lecture was that reached the key + + + align:start position:0% +lecture was that reached the key +equation ax equal lambda X X is the + + align:start position:0% +equation ax equal lambda X X is the + + + align:start position:0% +equation ax equal lambda X X is the +eigenvector and lambdas the eigenvalue + + align:start position:0% +eigenvector and lambdas the eigenvalue + + + align:start position:0% +eigenvector and lambdas the eigenvalue +now to use that and the the good way to + + align:start position:0% +now to use that and the the good way to + + + align:start position:0% +now to use that and the the good way to +after we found so so job one is to find + + align:start position:0% +after we found so so job one is to find + + + align:start position:0% +after we found so so job one is to find +the eigenvalues and find the + + align:start position:0% +the eigenvalues and find the + + + align:start position:0% +the eigenvalues and find the +eigenvectors now after we found them + + align:start position:0% +eigenvectors now after we found them + + + align:start position:0% +eigenvectors now after we found them +what do we do with them well the good + + align:start position:0% +what do we do with them well the good + + + align:start position:0% +what do we do with them well the good +way to see that is diagonalize the + + align:start position:0% +way to see that is diagonalize the + + + align:start position:0% +way to see that is diagonalize the +matrix so the matrix is a and I want to + + align:start position:0% +matrix so the matrix is a and I want to + + + align:start position:0% +matrix so the matrix is a and I want to +show first of all this is like the basic + + align:start position:0% +show first of all this is like the basic + + + align:start position:0% +show first of all this is like the basic +fact this this formula that's that's the + + align:start position:0% +fact this this formula that's that's the + + + align:start position:0% +fact this this formula that's that's the +key to today's lecture this matrix a I + + align:start position:0% +key to today's lecture this matrix a I + + + align:start position:0% +key to today's lecture this matrix a I +put its eigenvectors in the columns of a + + align:start position:0% +put its eigenvectors in the columns of a + + + align:start position:0% +put its eigenvectors in the columns of a +matrix s so s will be the eigenvector + + align:start position:0% +matrix s so s will be the eigenvector + + + align:start position:0% +matrix s so s will be the eigenvector +matrix and i want to look at this magic + + align:start position:0% +matrix and i want to look at this magic + + + align:start position:0% +matrix and i want to look at this magic +combination s inverse a s so can i show + + align:start position:0% +combination s inverse a s so can i show + + + align:start position:0% +combination s inverse a s so can i show +you how that how that what happens there + + align:start position:0% +you how that how that what happens there + + + align:start position:0% +you how that how that what happens there +and notice notice there's an S inverse + + align:start position:0% +and notice notice there's an S inverse + + + align:start position:0% +and notice notice there's an S inverse +we have to be able to invert this + + align:start position:0% +we have to be able to invert this + + + align:start position:0% +we have to be able to invert this +eigenvector matrix s so for that we need + + align:start position:0% +eigenvector matrix s so for that we need + + + align:start position:0% +eigenvector matrix s so for that we need +n independent eigenvectors so that's the + + align:start position:0% +n independent eigenvectors so that's the + + + align:start position:0% +n independent eigenvectors so that's the +that's the case okay so suppose we have + + align:start position:0% +that's the case okay so suppose we have + + + align:start position:0% +that's the case okay so suppose we have +n linearly independent eigen vectors of + + align:start position:0% + + + + align:start position:0% + +a + + align:start position:0% + + + + align:start position:0% + +put them in the columns of this matrix s + + align:start position:0% +put them in the columns of this matrix s + + + align:start position:0% +put them in the columns of this matrix s +so I'm naturally going to call that the + + align:start position:0% +so I'm naturally going to call that the + + + align:start position:0% +so I'm naturally going to call that the +eigenvector matrix because it's got the + + align:start position:0% +eigenvector matrix because it's got the + + + align:start position:0% +eigenvector matrix because it's got the +eigenvectors in its columns and all i + + align:start position:0% +eigenvectors in its columns and all i + + + align:start position:0% +eigenvectors in its columns and all i +want to do is show you what happens when + + align:start position:0% +want to do is show you what happens when + + + align:start position:0% +want to do is show you what happens when +you multiply a times s so a times s so + + align:start position:0% +you multiply a times s so a times s so + + + align:start position:0% +you multiply a times s so a times s so +this is a times the matrix with the + + align:start position:0% +this is a times the matrix with the + + + align:start position:0% +this is a times the matrix with the +first eigenvector in this first column + + align:start position:0% +first eigenvector in this first column + + + align:start position:0% +first eigenvector in this first column +the second eigenvector in its second + + align:start position:0% +the second eigenvector in its second + + + align:start position:0% +the second eigenvector in its second +column the nth eigen vector in its nth + + align:start position:0% +column the nth eigen vector in its nth + + + align:start position:0% +column the nth eigen vector in its nth +column and how am I going to do this + + align:start position:0% +column and how am I going to do this + + + align:start position:0% +column and how am I going to do this +matrix multiplication well certainly + + align:start position:0% +matrix multiplication well certainly + + + align:start position:0% +matrix multiplication well certainly +I'll do it a column at a time and what + + align:start position:0% +I'll do it a column at a time and what + + + align:start position:0% +I'll do it a column at a time and what +do I get a times the first column gives + + align:start position:0% +do I get a times the first column gives + + + align:start position:0% +do I get a times the first column gives +me the first column of the answer but + + align:start position:0% +me the first column of the answer but + + + align:start position:0% +me the first column of the answer but +what is it that's an eigenvector a times + + align:start position:0% +what is it that's an eigenvector a times + + + align:start position:0% +what is it that's an eigenvector a times +x1 is equal to the lambda times the x 1 + + align:start position:0% +x1 is equal to the lambda times the x 1 + + + align:start position:0% +x1 is equal to the lambda times the x 1 +and that lambdas we'll call lambda 1 of + + align:start position:0% +and that lambdas we'll call lambda 1 of + + + align:start position:0% +and that lambdas we'll call lambda 1 of +course so that's the first column ax 1 + + align:start position:0% +course so that's the first column ax 1 + + + align:start position:0% +course so that's the first column ax 1 +is the same as lambda 1 X 1 IX 2 is + + align:start position:0% +is the same as lambda 1 X 1 IX 2 is + + + align:start position:0% +is the same as lambda 1 X 1 IX 2 is +lambda 2 X 2 so on along to in the nth + + align:start position:0% +lambda 2 X 2 so on along to in the nth + + + align:start position:0% +lambda 2 X 2 so on along to in the nth +column we now have lambda n xn looking + + align:start position:0% +column we now have lambda n xn looking + + + align:start position:0% +column we now have lambda n xn looking +good but the next step is even better so + + align:start position:0% +good but the next step is even better so + + + align:start position:0% +good but the next step is even better so +for the next step I want to separate out + + align:start position:0% +for the next step I want to separate out + + + align:start position:0% +for the next step I want to separate out +those eigenvalues those those + + align:start position:0% +those eigenvalues those those + + + align:start position:0% +those eigenvalues those those +multiplying numbers from the X's so then + + align:start position:0% +multiplying numbers from the X's so then + + + align:start position:0% +multiplying numbers from the X's so then +I'll have just what I want okay so how + + align:start position:0% +I'll have just what I want okay so how + + + align:start position:0% +I'll have just what I want okay so how +am I going to separate out so that that + + align:start position:0% +am I going to separate out so that that + + + align:start position:0% +am I going to separate out so that that +number lambda 1 is multiplying the first + + align:start position:0% +number lambda 1 is multiplying the first + + + align:start position:0% +number lambda 1 is multiplying the first +column so if I want to factor it out of + + align:start position:0% +column so if I want to factor it out of + + + align:start position:0% +column so if I want to factor it out of +the first column I better put here is + + align:start position:0% +the first column I better put here is + + + align:start position:0% +the first column I better put here is +going to be X 1 and that's going to + + align:start position:0% +going to be X 1 and that's going to + + + align:start position:0% +going to be X 1 and that's going to +multiply this matrix lambda 1 in the + + align:start position:0% +multiply this matrix lambda 1 in the + + + align:start position:0% +multiply this matrix lambda 1 in the +first entry in all zeros you see that + + align:start position:0% +first entry in all zeros you see that + + + align:start position:0% +first entry in all zeros you see that +that that's going to come out right for + + align:start position:0% +that that's going to come out right for + + + align:start position:0% +that that's going to come out right for +the first column because we remember how + + align:start position:0% +the first column because we remember how + + + align:start position:0% +the first column because we remember how +we're going back to that original + + align:start position:0% +we're going back to that original + + + align:start position:0% +we're going back to that original +punchline that if I want a number to + + align:start position:0% +punchline that if I want a number to + + + align:start position:0% +punchline that if I want a number to +multiply X 1 then I can do it by putting + + align:start position:0% +multiply X 1 then I can do it by putting + + + align:start position:0% +multiply X 1 then I can do it by putting +X 1 in that column in the first column + + align:start position:0% +X 1 in that column in the first column + + + align:start position:0% +X 1 in that column in the first column +and putting that number there what am I + + align:start position:0% +and putting that number there what am I + + + align:start position:0% +and putting that number there what am I +going to have here I'm going to have + + align:start position:0% +going to have here I'm going to have + + + align:start position:0% +going to have here I'm going to have +lambda what I'm going to have X 1 X 2 xn + + align:start position:0% +lambda what I'm going to have X 1 X 2 xn + + + align:start position:0% +lambda what I'm going to have X 1 X 2 xn +these are going to be my columns again + + align:start position:0% +these are going to be my columns again + + + align:start position:0% +these are going to be my columns again +I'm getting s back again I'm getting s + + align:start position:0% +I'm getting s back again I'm getting s + + + align:start position:0% +I'm getting s back again I'm getting s +back again but now what's it x on the + + align:start position:0% +back again but now what's it x on the + + + align:start position:0% +back again but now what's it x on the +right its x if I want if I want lambda n + + align:start position:0% +right its x if I want if I want lambda n + + + align:start position:0% +right its x if I want if I want lambda n +xn in the last column how do I do it + + align:start position:0% +xn in the last column how do I do it + + + align:start position:0% +xn in the last column how do I do it +well the last column here will be I'll + + align:start position:0% +well the last column here will be I'll + + + align:start position:0% +well the last column here will be I'll +take the last column use these + + align:start position:0% +take the last column use these + + + align:start position:0% +take the last column use these +coefficients put the lambda end down + + align:start position:0% +coefficients put the lambda end down + + + align:start position:0% +coefficients put the lambda end down +there and it will multiply that nth + + align:start position:0% +there and it will multiply that nth + + + align:start position:0% +there and it will multiply that nth +column and give me lambda n xn there + + align:start position:0% +column and give me lambda n xn there + + + align:start position:0% +column and give me lambda n xn there +there you see matrix multiplication just + + align:start position:0% +there you see matrix multiplication just + + + align:start position:0% +there you see matrix multiplication just +working for us so I started with a s I + + align:start position:0% +working for us so I started with a s I + + + align:start position:0% +working for us so I started with a s I +wrote down what it meant a times each + + align:start position:0% +wrote down what it meant a times each + + + align:start position:0% +wrote down what it meant a times each +eigenvector that gave me lambda times + + align:start position:0% +eigenvector that gave me lambda times + + + align:start position:0% +eigenvector that gave me lambda times +the eigenvector and then when I peeled + + align:start position:0% +the eigenvector and then when I peeled + + + align:start position:0% +the eigenvector and then when I peeled +off the lambdas they were on the + + align:start position:0% +off the lambdas they were on the + + + align:start position:0% +off the lambdas they were on the +right-hand side so I've got s my matrix + + align:start position:0% +right-hand side so I've got s my matrix + + + align:start position:0% +right-hand side so I've got s my matrix +back again and this matrix this diagonal + + align:start position:0% +back again and this matrix this diagonal + + + align:start position:0% +back again and this matrix this diagonal +matrix the eigen value matrix and I call + + align:start position:0% +matrix the eigen value matrix and I call + + + align:start position:0% +matrix the eigen value matrix and I call +it capital lambda using capital letters + + align:start position:0% +it capital lambda using capital letters + + + align:start position:0% +it capital lambda using capital letters +for matrices and lambda to prompt me + + align:start position:0% +for matrices and lambda to prompt me + + + align:start position:0% +for matrices and lambda to prompt me +that it's that it's eigen values that + + align:start position:0% +that it's that it's eigen values that + + + align:start position:0% +that it's that it's eigen values that +are in there so you see that the + + align:start position:0% +are in there so you see that the + + + align:start position:0% +are in there so you see that the +eigenvalues are just sitting down that + + align:start position:0% +eigenvalues are just sitting down that + + + align:start position:0% +eigenvalues are just sitting down that +diagonal if I had a column x2 here I + + align:start position:0% +diagonal if I had a column x2 here I + + + align:start position:0% +diagonal if I had a column x2 here I +would want the lambda 2 in the two tube + + align:start position:0% +would want the lambda 2 in the two tube + + + align:start position:0% +would want the lambda 2 in the two tube +position in the diagonal position to + + align:start position:0% +position in the diagonal position to + + + align:start position:0% +position in the diagonal position to +multiply that X 2 and give me the lambda + + align:start position:0% +multiply that X 2 and give me the lambda + + + align:start position:0% +multiply that X 2 and give me the lambda +2 X 2 that's my formula a s is s lambda + + align:start position:0% + + + + align:start position:0% + +okay that's that's the you see it's just + + align:start position:0% +okay that's that's the you see it's just + + + align:start position:0% +okay that's that's the you see it's just +a calculation now I mentioned and I have + + align:start position:0% +a calculation now I mentioned and I have + + + align:start position:0% +a calculation now I mentioned and I have +to mention again this business about an + + align:start position:0% +to mention again this business about an + + + align:start position:0% +to mention again this business about an +independent eigenvectors as it stands + + align:start position:0% +independent eigenvectors as it stands + + + align:start position:0% +independent eigenvectors as it stands +this is all fine whether I mean I could + + align:start position:0% +this is all fine whether I mean I could + + + align:start position:0% +this is all fine whether I mean I could +be repeating the same eigenvector but I + + align:start position:0% +be repeating the same eigenvector but I + + + align:start position:0% +be repeating the same eigenvector but I +am no interest in that I want to be able + + align:start position:0% +am no interest in that I want to be able + + + align:start position:0% +am no interest in that I want to be able +to invert s and that's where this comes + + align:start position:0% +to invert s and that's where this comes + + + align:start position:0% +to invert s and that's where this comes +in this n independent eigenvectors + + align:start position:0% +in this n independent eigenvectors + + + align:start position:0% +in this n independent eigenvectors +business comes in to tell me that that + + align:start position:0% +business comes in to tell me that that + + + align:start position:0% +business comes in to tell me that that +matrix is invertible so let me on the + + align:start position:0% +matrix is invertible so let me on the + + + align:start position:0% +matrix is invertible so let me on the +next board write down what I've got a s + + align:start position:0% +next board write down what I've got a s + + + align:start position:0% +next board write down what I've got a s +equals s lambda and now I can multiply + + align:start position:0% +equals s lambda and now I can multiply + + + align:start position:0% +equals s lambda and now I can multiply +on the left by s inverse so this is + + align:start position:0% +on the left by s inverse so this is + + + align:start position:0% +on the left by s inverse so this is +really I can do that provided s is + + align:start position:0% +really I can do that provided s is + + + align:start position:0% +really I can do that provided s is +invertible provided my assumption of n + + align:start position:0% +invertible provided my assumption of n + + + align:start position:0% +invertible provided my assumption of n +independent eigenvectors is satisfied + + align:start position:0% +independent eigenvectors is satisfied + + + align:start position:0% +independent eigenvectors is satisfied +and i mentioned at the end of last time + + align:start position:0% +and i mentioned at the end of last time + + + align:start position:0% +and i mentioned at the end of last time +and i'll say again that there's a small + + align:start position:0% +and i'll say again that there's a small + + + align:start position:0% +and i'll say again that there's a small +number of matrices for that don't have n + + align:start position:0% +number of matrices for that don't have n + + + align:start position:0% +number of matrices for that don't have n +independent eigenvectors so i've got to + + align:start position:0% +independent eigenvectors so i've got to + + + align:start position:0% +independent eigenvectors so i've got to +discuss that that technical point but + + align:start position:0% +discuss that that technical point but + + + align:start position:0% +discuss that that technical point but +the great the most matrices that we see + + align:start position:0% +the great the most matrices that we see + + + align:start position:0% +the great the most matrices that we see +have end n independent eigenvectors and + + align:start position:0% +have end n independent eigenvectors and + + + align:start position:0% +have end n independent eigenvectors and +we can diagonalize this is + + align:start position:0% +we can diagonalize this is + + + align:start position:0% +we can diagonalize this is +diagonalization i could also write it + + align:start position:0% +diagonalization i could also write it + + + align:start position:0% +diagonalization i could also write it +and I often will the other way round if + + align:start position:0% +and I often will the other way round if + + + align:start position:0% +and I often will the other way round if +I multiply on the right by s inverse if + + align:start position:0% +I multiply on the right by s inverse if + + + align:start position:0% +I multiply on the right by s inverse if +I took this equation at the top and + + align:start position:0% +I took this equation at the top and + + + align:start position:0% +I took this equation at the top and +multiply on the right by s inverse I + + align:start position:0% +multiply on the right by s inverse I + + + align:start position:0% +multiply on the right by s inverse I +could I would have a left here now s + + align:start position:0% +could I would have a left here now s + + + align:start position:0% +could I would have a left here now s +inverse is coming from the right so can + + align:start position:0% +inverse is coming from the right so can + + + align:start position:0% +inverse is coming from the right so can +you keep those two straight a multiplies + + align:start position:0% +you keep those two straight a multiplies + + + align:start position:0% +you keep those two straight a multiplies +its eigenvectors that's how i keep them + + align:start position:0% +its eigenvectors that's how i keep them + + + align:start position:0% +its eigenvectors that's how i keep them +straight so a multiplies s a multiplies + + align:start position:0% +straight so a multiplies s a multiplies + + + align:start position:0% +straight so a multiplies s a multiplies +this and then this s inverse makes the + + align:start position:0% +this and then this s inverse makes the + + + align:start position:0% +this and then this s inverse makes the +whole thing diagonal and this is another + + align:start position:0% +whole thing diagonal and this is another + + + align:start position:0% +whole thing diagonal and this is another +way of saying the same thing putting the + + align:start position:0% +way of saying the same thing putting the + + + align:start position:0% +way of saying the same thing putting the +S is on the other side of the equation + + align:start position:0% +S is on the other side of the equation + + + align:start position:0% +S is on the other side of the equation +vision a is s lambda s inverse so that's + + align:start position:0% +vision a is s lambda s inverse so that's + + + align:start position:0% +vision a is s lambda s inverse so that's +the that's the new factorization that's + + align:start position:0% +the that's the new factorization that's + + + align:start position:0% +the that's the new factorization that's +the replacement for Lu from elimination + + align:start position:0% +the replacement for Lu from elimination + + + align:start position:0% +the replacement for Lu from elimination +or QR from gram-schmidt and notice that + + align:start position:0% +or QR from gram-schmidt and notice that + + + align:start position:0% +or QR from gram-schmidt and notice that +the matrix so it's it's a matrix times + + align:start position:0% +the matrix so it's it's a matrix times + + + align:start position:0% +the matrix so it's it's a matrix times +the diagonal matrix times the inverse of + + align:start position:0% +the diagonal matrix times the inverse of + + + align:start position:0% +the diagonal matrix times the inverse of +the first one it's is that's the + + align:start position:0% +the first one it's is that's the + + + align:start position:0% +the first one it's is that's the +combination that we'll see throughout + + align:start position:0% +combination that we'll see throughout + + + align:start position:0% +combination that we'll see throughout +this chapter this this combination with + + align:start position:0% +this chapter this this combination with + + + align:start position:0% +this chapter this this combination with +an S and an S inverse okay can I just + + align:start position:0% +an S and an S inverse okay can I just + + + align:start position:0% +an S and an S inverse okay can I just +begin to use that for example what about + + align:start position:0% +begin to use that for example what about + + + align:start position:0% +begin to use that for example what about +a squared what are the eigenvalues and + + align:start position:0% +a squared what are the eigenvalues and + + + align:start position:0% +a squared what are the eigenvalues and +eigenvectors of a squared that's a + + align:start position:0% +eigenvectors of a squared that's a + + + align:start position:0% +eigenvectors of a squared that's a +straightforward question with it with an + + align:start position:0% +straightforward question with it with an + + + align:start position:0% +straightforward question with it with an +absolutely clean answer so let me let me + + align:start position:0% +absolutely clean answer so let me let me + + + align:start position:0% +absolutely clean answer so let me let me +consider a squared so I start with ax + + align:start position:0% +consider a squared so I start with ax + + + align:start position:0% +consider a squared so I start with ax +equal lambda X and I'm headed for a + + align:start position:0% +equal lambda X and I'm headed for a + + + align:start position:0% +equal lambda X and I'm headed for a +squared so let me multiply both sides by + + align:start position:0% +squared so let me multiply both sides by + + + align:start position:0% +squared so let me multiply both sides by +a that's one way to get a squared on the + + align:start position:0% +a that's one way to get a squared on the + + + align:start position:0% +a that's one way to get a squared on the +left so if I should write these ifs in + + align:start position:0% +left so if I should write these ifs in + + + align:start position:0% +left so if I should write these ifs in +here if ax equals lambda X then I + + align:start position:0% +here if ax equals lambda X then I + + + align:start position:0% +here if ax equals lambda X then I +multiply by a so I get a squared x + + align:start position:0% +multiply by a so I get a squared x + + + align:start position:0% +multiply by a so I get a squared x +equals while I'm multiplying by a so + + align:start position:0% +equals while I'm multiplying by a so + + + align:start position:0% +equals while I'm multiplying by a so +that's lambda a X that lambda was a + + align:start position:0% +that's lambda a X that lambda was a + + + align:start position:0% +that's lambda a X that lambda was a +number so I just put it on the left and + + align:start position:0% +number so I just put it on the left and + + + align:start position:0% +number so I just put it on the left and +what do I did tell me how to make that + + align:start position:0% +what do I did tell me how to make that + + + align:start position:0% +what do I did tell me how to make that +look better what have I got here + + align:start position:0% +look better what have I got here + + + align:start position:0% +look better what have I got here +for if a has the eigenvalue lambda and + + align:start position:0% +for if a has the eigenvalue lambda and + + + align:start position:0% +for if a has the eigenvalue lambda and +eigenvector x what's up with a squared a + + align:start position:0% +eigenvector x what's up with a squared a + + + align:start position:0% +eigenvector x what's up with a squared a +squared X I just multiplied by a but now + + align:start position:0% +squared X I just multiplied by a but now + + + align:start position:0% +squared X I just multiplied by a but now +for a X I'm going to substitute lambda X + + align:start position:0% +for a X I'm going to substitute lambda X + + + align:start position:0% +for a X I'm going to substitute lambda X +so I've got lambda squared X so from + + align:start position:0% +so I've got lambda squared X so from + + + align:start position:0% +so I've got lambda squared X so from +that simple calculation I my conclusion + + align:start position:0% +that simple calculation I my conclusion + + + align:start position:0% +that simple calculation I my conclusion +is that the eigenvalues of a squared are + + align:start position:0% +is that the eigenvalues of a squared are + + + align:start position:0% +is that the eigenvalues of a squared are +lambda squared and the eigenvectors i + + align:start position:0% +lambda squared and the eigenvectors i + + + align:start position:0% +lambda squared and the eigenvectors i +always think about both of those what + + align:start position:0% +always think about both of those what + + + align:start position:0% +always think about both of those what +can i say about the eigenvalues they're + + align:start position:0% +can i say about the eigenvalues they're + + + align:start position:0% +can i say about the eigenvalues they're +squared what can I say about the + + align:start position:0% +squared what can I say about the + + + align:start position:0% +squared what can I say about the +eigenvectors they're the same + + align:start position:0% +eigenvectors they're the same + + + align:start position:0% +eigenvectors they're the same +the same X is in s for a now let me see + + align:start position:0% +the same X is in s for a now let me see + + + align:start position:0% +the same X is in s for a now let me see +that also from this formula how can I + + align:start position:0% +that also from this formula how can I + + + align:start position:0% +that also from this formula how can I +see what a squared is looking like from + + align:start position:0% +see what a squared is looking like from + + + align:start position:0% +see what a squared is looking like from +this formula so let me that was one way + + align:start position:0% +this formula so let me that was one way + + + align:start position:0% +this formula so let me that was one way +to do it let me do it by just taking a + + align:start position:0% +to do it let me do it by just taking a + + + align:start position:0% +to do it let me do it by just taking a +squared from that a squared is s lambda + + align:start position:0% +squared from that a squared is s lambda + + + align:start position:0% +squared from that a squared is s lambda +s inverse that's a times s lambda s + + align:start position:0% +s inverse that's a times s lambda s + + + align:start position:0% +s inverse that's a times s lambda s +inverse that's a which is this is the + + align:start position:0% +inverse that's a which is this is the + + + align:start position:0% +inverse that's a which is this is the +beauty of eigenvalues eigenvectors + + align:start position:0% +beauty of eigenvalues eigenvectors + + + align:start position:0% +beauty of eigenvalues eigenvectors +having that s inverse and s is the + + align:start position:0% +having that s inverse and s is the + + + align:start position:0% +having that s inverse and s is the +identity so i've got s lambda squared s + + align:start position:0% +identity so i've got s lambda squared s + + + align:start position:0% +identity so i've got s lambda squared s +inverse you see what that's telling me + + align:start position:0% +inverse you see what that's telling me + + + align:start position:0% +inverse you see what that's telling me +it's telling me the same thing that I + + align:start position:0% +it's telling me the same thing that I + + + align:start position:0% +it's telling me the same thing that I +just learned here but in the in a matrix + + align:start position:0% +just learned here but in the in a matrix + + + align:start position:0% +just learned here but in the in a matrix +form it's telling me that the S is the + + align:start position:0% +form it's telling me that the S is the + + + align:start position:0% +form it's telling me that the S is the +same the eigenvectors are the same but + + align:start position:0% +same the eigenvectors are the same but + + + align:start position:0% +same the eigenvectors are the same but +the eigenvalues are squared because this + + align:start position:0% +the eigenvalues are squared because this + + + align:start position:0% +the eigenvalues are squared because this +is what's lambda squared that's still + + align:start position:0% +is what's lambda squared that's still + + + align:start position:0% +is what's lambda squared that's still +diagonal it's got little lambda 1 + + align:start position:0% +diagonal it's got little lambda 1 + + + align:start position:0% +diagonal it's got little lambda 1 +squared lambda 2 squared down to lambda + + align:start position:0% +squared lambda 2 squared down to lambda + + + align:start position:0% +squared lambda 2 squared down to lambda +n squared on that diagonal those are the + + align:start position:0% +n squared on that diagonal those are the + + + align:start position:0% +n squared on that diagonal those are the +eigenvalues as we just learned of a + + align:start position:0% +eigenvalues as we just learned of a + + + align:start position:0% +eigenvalues as we just learned of a +squared okay so somehow those + + align:start position:0% +squared okay so somehow those + + + align:start position:0% +squared okay so somehow those +eigenvalues and eigenvectors are really + + align:start position:0% +eigenvalues and eigenvectors are really + + + align:start position:0% +eigenvalues and eigenvectors are really +giving you a way to to to see what's + + align:start position:0% +giving you a way to to to see what's + + + align:start position:0% +giving you a way to to to see what's +going on inside a matrix now of course I + + align:start position:0% +going on inside a matrix now of course I + + + align:start position:0% +going on inside a matrix now of course I +can continue that for to the case power + + align:start position:0% +can continue that for to the case power + + + align:start position:0% +can continue that for to the case power +a to the case power if I multiply if I + + align:start position:0% +a to the case power if I multiply if I + + + align:start position:0% +a to the case power if I multiply if I +have K of these together you see how s + + align:start position:0% +have K of these together you see how s + + + align:start position:0% +have K of these together you see how s +inverse s will keep canceling in the in + + align:start position:0% +inverse s will keep canceling in the in + + + align:start position:0% +inverse s will keep canceling in the in +the inside I'll have the s outside at + + align:start position:0% +the inside I'll have the s outside at + + + align:start position:0% +the inside I'll have the s outside at +the far left and lambda will be in there + + align:start position:0% +the far left and lambda will be in there + + + align:start position:0% +the far left and lambda will be in there +K times and s inverse so what's that + + align:start position:0% +K times and s inverse so what's that + + + align:start position:0% +K times and s inverse so what's that +telling me that's telling me that the + + align:start position:0% +telling me that's telling me that the + + + align:start position:0% +telling me that's telling me that the +eigenvalues of a of a to the K power are + + align:start position:0% +eigenvalues of a of a to the K power are + + + align:start position:0% +eigenvalues of a of a to the K power are +the K power + + align:start position:0% +the K power + + + align:start position:0% +the K power +the eigenvalues of a cubed are the cubes + + align:start position:0% +the eigenvalues of a cubed are the cubes + + + align:start position:0% +the eigenvalues of a cubed are the cubes +of the eigenvalues of a and the + + align:start position:0% +of the eigenvalues of a and the + + + align:start position:0% +of the eigenvalues of a and the +eigenvectors are the same the same okay + + align:start position:0% +eigenvectors are the same the same okay + + + align:start position:0% +eigenvectors are the same the same okay +in other words eigenvalues and + + align:start position:0% +in other words eigenvalues and + + + align:start position:0% +in other words eigenvalues and +eigenvectors give a great way to + + align:start position:0% +eigenvectors give a great way to + + + align:start position:0% +eigenvectors give a great way to +understand the powers of a matrix if I + + align:start position:0% +understand the powers of a matrix if I + + + align:start position:0% +understand the powers of a matrix if I +take this square of a matrix or the + + align:start position:0% +take this square of a matrix or the + + + align:start position:0% +take this square of a matrix or the +hundredth power of a matrix the pivots + + align:start position:0% +hundredth power of a matrix the pivots + + + align:start position:0% +hundredth power of a matrix the pivots +are all over the place + + align:start position:0% +are all over the place + + + align:start position:0% +are all over the place +Lu if I multiply lu x lu x lu x lu a + + align:start position:0% +Lu if I multiply lu x lu x lu x lu a + + + align:start position:0% +Lu if I multiply lu x lu x lu x lu a +hundred times i've got a hundred l use i + + align:start position:0% +hundred times i've got a hundred l use i + + + align:start position:0% +hundred times i've got a hundred l use i +can't do anything with them but when i + + align:start position:0% +can't do anything with them but when i + + + align:start position:0% +can't do anything with them but when i +multiply s lambda s inverse by itself + + align:start position:0% +multiply s lambda s inverse by itself + + + align:start position:0% +multiply s lambda s inverse by itself +when I look at the eigenvector picture a + + align:start position:0% +when I look at the eigenvector picture a + + + align:start position:0% +when I look at the eigenvector picture a +hundred times I get a hundred or 99 of + + align:start position:0% +hundred times I get a hundred or 99 of + + + align:start position:0% +hundred times I get a hundred or 99 of +these guys cancelling out inside and I + + align:start position:0% +these guys cancelling out inside and I + + + align:start position:0% +these guys cancelling out inside and I +get a to the hundredth is s lambda to + + align:start position:0% +get a to the hundredth is s lambda to + + + align:start position:0% +get a to the hundredth is s lambda to +the hundredth s inverse I mean + + align:start position:0% +the hundredth s inverse I mean + + + align:start position:0% +the hundredth s inverse I mean +eigenvalues tell you about powers of a + + align:start position:0% +eigenvalues tell you about powers of a + + + align:start position:0% +eigenvalues tell you about powers of a +matrix in a way that we had no no way to + + align:start position:0% +matrix in a way that we had no no way to + + + align:start position:0% +matrix in a way that we had no no way to +approach previously for example when + + align:start position:0% +approach previously for example when + + + align:start position:0% +approach previously for example when +does when do the powers of a matrix go + + align:start position:0% +does when do the powers of a matrix go + + + align:start position:0% +does when do the powers of a matrix go +to zero I would call that matrix stable + + align:start position:0% +to zero I would call that matrix stable + + + align:start position:0% +to zero I would call that matrix stable +maybe so so so I could write down a + + align:start position:0% +maybe so so so I could write down a + + + align:start position:0% +maybe so so so I could write down a +theorem I'll write it as a theorem just + + align:start position:0% +theorem I'll write it as a theorem just + + + align:start position:0% +theorem I'll write it as a theorem just +use that word to emphasize that here I'm + + align:start position:0% +use that word to emphasize that here I'm + + + align:start position:0% +use that word to emphasize that here I'm +getting this great fact from this + + align:start position:0% +getting this great fact from this + + + align:start position:0% +getting this great fact from this +eigenvalue picture okay a to the K + + align:start position:0% +eigenvalue picture okay a to the K + + + align:start position:0% +eigenvalue picture okay a to the K +approaches zero as K goes as K gets + + align:start position:0% +approaches zero as K goes as K gets + + + align:start position:0% +approaches zero as K goes as K gets +bigger if what what's the how can I tell + + align:start position:0% +bigger if what what's the how can I tell + + + align:start position:0% +bigger if what what's the how can I tell +for a matrix a if its powers go to zero + + align:start position:0% + + + + align:start position:0% + +what's somewhere inside that matrix is + + align:start position:0% +what's somewhere inside that matrix is + + + align:start position:0% +what's somewhere inside that matrix is +that information that information is not + + align:start position:0% +that information that information is not + + + align:start position:0% +that information that information is not +present in the pivots it's present in + + align:start position:0% +present in the pivots it's present in + + + align:start position:0% +present in the pivots it's present in +the eigenvalues what do I need for the + + align:start position:0% +the eigenvalues what do I need for the + + + align:start position:0% +the eigenvalues what do I need for the +to know that if I take + + align:start position:0% +to know that if I take + + + align:start position:0% +to know that if I take +I earn higher powers of a that this + + align:start position:0% +I earn higher powers of a that this + + + align:start position:0% +I earn higher powers of a that this +matrix gets smaller and smaller well s + + align:start position:0% +matrix gets smaller and smaller well s + + + align:start position:0% +matrix gets smaller and smaller well s +and s inverse are not moving + + align:start position:0% +and s inverse are not moving + + + align:start position:0% +and s inverse are not moving +so it's this guy that has to get small + + align:start position:0% +so it's this guy that has to get small + + + align:start position:0% +so it's this guy that has to get small +and that's easy too easy to understand + + align:start position:0% +and that's easy too easy to understand + + + align:start position:0% +and that's easy too easy to understand +the requirement is all eigenvalues so + + align:start position:0% +the requirement is all eigenvalues so + + + align:start position:0% +the requirement is all eigenvalues so +what is a requirement the eigenvalues + + align:start position:0% +what is a requirement the eigenvalues + + + align:start position:0% +what is a requirement the eigenvalues +have to be less than one now I have to + + align:start position:0% +have to be less than one now I have to + + + align:start position:0% +have to be less than one now I have to +write that absolute value because those + + align:start position:0% +write that absolute value because those + + + align:start position:0% +write that absolute value because those +eigenvalues could be negative they could + + align:start position:0% +eigenvalues could be negative they could + + + align:start position:0% +eigenvalues could be negative they could +be complex numbers so I'm taking the + + align:start position:0% +be complex numbers so I'm taking the + + + align:start position:0% +be complex numbers so I'm taking the +absolute value half if all of those are + + align:start position:0% +absolute value half if all of those are + + + align:start position:0% +absolute value half if all of those are +below one that's in fact we practically + + align:start position:0% +below one that's in fact we practically + + + align:start position:0% +below one that's in fact we practically +see why let me just say that I that I + + align:start position:0% + + + + align:start position:0% + +operating on one assumption here and I + + align:start position:0% +operating on one assumption here and I + + + align:start position:0% +operating on one assumption here and I +gotta keep remembering that that + + align:start position:0% +gotta keep remembering that that + + + align:start position:0% +gotta keep remembering that that +assumption is still present that + + align:start position:0% +assumption is still present that + + + align:start position:0% +assumption is still present that +assumption was that I had a full set of + + align:start position:0% +assumption was that I had a full set of + + + align:start position:0% +assumption was that I had a full set of +of n independent eigenvectors if I don't + + align:start position:0% +of n independent eigenvectors if I don't + + + align:start position:0% +of n independent eigenvectors if I don't +have that then I then this approach is + + align:start position:0% +have that then I then this approach is + + + align:start position:0% +have that then I then this approach is +not working so so again a pure + + align:start position:0% +not working so so again a pure + + + align:start position:0% +not working so so again a pure +eigenvalue approach eigenvector approach + + align:start position:0% +eigenvalue approach eigenvector approach + + + align:start position:0% +eigenvalue approach eigenvector approach +needs and independent eigenvectors if we + + align:start position:0% +needs and independent eigenvectors if we + + + align:start position:0% +needs and independent eigenvectors if we +don't have n independent eigenvectors we + + align:start position:0% +don't have n independent eigenvectors we + + + align:start position:0% +don't have n independent eigenvectors we +can't diagonalize the matrix we can't + + align:start position:0% +can't diagonalize the matrix we can't + + + align:start position:0% +can't diagonalize the matrix we can't +get to a diagonal matrix this this this + + align:start position:0% +get to a diagonal matrix this this this + + + align:start position:0% +get to a diagonal matrix this this this +diagonalization is only possible if s + + align:start position:0% +diagonalization is only possible if s + + + align:start position:0% +diagonalization is only possible if s +inverse makes sense + + align:start position:0% +inverse makes sense + + + align:start position:0% +inverse makes sense +okay can I can I follow up on that point + + align:start position:0% +okay can I can I follow up on that point + + + align:start position:0% +okay can I can I follow up on that point +now so so you see why what we get and + + align:start position:0% +now so so you see why what we get and + + + align:start position:0% +now so so you see why what we get and +and why we want it because we get + + align:start position:0% +and why we want it because we get + + + align:start position:0% +and why we want it because we get +information about the powers of a matrix + + align:start position:0% +information about the powers of a matrix + + + align:start position:0% +information about the powers of a matrix +just immediately from the eigenvalues + + align:start position:0% +just immediately from the eigenvalues + + + align:start position:0% +just immediately from the eigenvalues +okay now let me follow up on this + + align:start position:0% +okay now let me follow up on this + + + align:start position:0% +okay now let me follow up on this +business of which matrices are + + align:start position:0% +business of which matrices are + + + align:start position:0% +business of which matrices are +diagonalizable sorry about that long + + align:start position:0% +diagonalizable sorry about that long + + + align:start position:0% +diagonalizable sorry about that long +word so a matrix is + + align:start position:0% +word so a matrix is + + + align:start position:0% +word so a matrix is +sure so here's here's the main point a + + align:start position:0% +sure so here's here's the main point a + + + align:start position:0% +sure so here's here's the main point a +is sure to be to have n independent + + align:start position:0% +is sure to be to have n independent + + + align:start position:0% +is sure to be to have n independent +eigenvectors and and B now here comes + + align:start position:0% +eigenvectors and and B now here comes + + + align:start position:0% +eigenvectors and and B now here comes +that word diagonalizable if if so we + + align:start position:0% +that word diagonalizable if if so we + + + align:start position:0% +that word diagonalizable if if so we +might as well get the nice case out in + + align:start position:0% +might as well get the nice case out in + + + align:start position:0% +might as well get the nice case out in +the open the nice case is when if all + + align:start position:0% +the open the nice case is when if all + + + align:start position:0% +the open the nice case is when if all +the lambdas are different that means + + align:start position:0% + + + + align:start position:0% + +that means no repeated eigenvalues okay + + align:start position:0% +that means no repeated eigenvalues okay + + + align:start position:0% +that means no repeated eigenvalues okay +that's the nice case if my matrix and + + align:start position:0% +that's the nice case if my matrix and + + + align:start position:0% +that's the nice case if my matrix and +most Maitre if I do a random matrix in + + align:start position:0% +most Maitre if I do a random matrix in + + + align:start position:0% +most Maitre if I do a random matrix in +MATLAB and compute its eigenvalues so if + + align:start position:0% +MATLAB and compute its eigenvalues so if + + + align:start position:0% +MATLAB and compute its eigenvalues so if +I computed if I took I of ran of ten ten + + align:start position:0% + + + + align:start position:0% + +gave that MATLAB command the we'd get a + + align:start position:0% +gave that MATLAB command the we'd get a + + + align:start position:0% +gave that MATLAB command the we'd get a +random 10 by 10 matrix we would get a + + align:start position:0% +random 10 by 10 matrix we would get a + + + align:start position:0% +random 10 by 10 matrix we would get a +list of its ten eigenvalues and they + + align:start position:0% +list of its ten eigenvalues and they + + + align:start position:0% +list of its ten eigenvalues and they +would be different they would be + + align:start position:0% +would be different they would be + + + align:start position:0% +would be different they would be +distinct is the best word I would have a + + align:start position:0% +distinct is the best word I would have a + + + align:start position:0% +distinct is the best word I would have a +random matrix will have ten distinct + + align:start position:0% +random matrix will have ten distinct + + + align:start position:0% +random matrix will have ten distinct +that 10 by 10 matrix will have ten + + align:start position:0% +that 10 by 10 matrix will have ten + + + align:start position:0% +that 10 by 10 matrix will have ten +distinct eigenvalues and if it does the + + align:start position:0% +distinct eigenvalues and if it does the + + + align:start position:0% +distinct eigenvalues and if it does the +eigenvectors are automatically + + align:start position:0% +eigenvectors are automatically + + + align:start position:0% +eigenvectors are automatically +independent so that's a nice fact I + + align:start position:0% +independent so that's a nice fact I + + + align:start position:0% +independent so that's a nice fact I +could I'll refer you to the text for the + + align:start position:0% +could I'll refer you to the text for the + + + align:start position:0% +could I'll refer you to the text for the +proof that that a is sure to have an + + align:start position:0% +proof that that a is sure to have an + + + align:start position:0% +proof that that a is sure to have an +independent eigenvectors if the + + align:start position:0% +independent eigenvectors if the + + + align:start position:0% +independent eigenvectors if the +eigenvalues are different if if all the + + align:start position:0% +eigenvalues are different if if all the + + + align:start position:0% +eigenvalues are different if if all the +if all eigenvalues are + + align:start position:0% +if all eigenvalues are + + + align:start position:0% +if all eigenvalues are +it's just if some lambdas are repeated + + align:start position:0% +it's just if some lambdas are repeated + + + align:start position:0% +it's just if some lambdas are repeated +then I have to look more closely if an + + align:start position:0% +then I have to look more closely if an + + + align:start position:0% +then I have to look more closely if an +eigenvalue is repeated I have to look I + + align:start position:0% +eigenvalue is repeated I have to look I + + + align:start position:0% +eigenvalue is repeated I have to look I +have to count at the chick has it got + + align:start position:0% +have to count at the chick has it got + + + align:start position:0% +have to count at the chick has it got +say it's repeated three times so what's + + align:start position:0% +say it's repeated three times so what's + + + align:start position:0% +say it's repeated three times so what's +a possibility for the so it's so here's + + align:start position:0% +a possibility for the so it's so here's + + + align:start position:0% +a possibility for the so it's so here's +here's the repeated possibility and let + + align:start position:0% +here's the repeated possibility and let + + + align:start position:0% +here's the repeated possibility and let +me emphasize the conclusion that if I + + align:start position:0% +me emphasize the conclusion that if I + + + align:start position:0% +me emphasize the conclusion that if I +have repeated eigenvalues I may or may + + align:start position:0% +have repeated eigenvalues I may or may + + + align:start position:0% +have repeated eigenvalues I may or may +not I may or may not have have n + + align:start position:0% +not I may or may not have have n + + + align:start position:0% +not I may or may not have have n +independent eigenvectors I might I you + + align:start position:0% +independent eigenvectors I might I you + + + align:start position:0% +independent eigenvectors I might I you +know this isn't a completely negative + + align:start position:0% +know this isn't a completely negative + + + align:start position:0% +know this isn't a completely negative +case the identity matrix well suppose I + + align:start position:0% +case the identity matrix well suppose I + + + align:start position:0% +case the identity matrix well suppose I +take the ten by ten identity matrix what + + align:start position:0% +take the ten by ten identity matrix what + + + align:start position:0% +take the ten by ten identity matrix what +are the eigenvalues of that matrix so + + align:start position:0% +are the eigenvalues of that matrix so + + + align:start position:0% +are the eigenvalues of that matrix so +just let's take the easiest matrix the + + align:start position:0% +just let's take the easiest matrix the + + + align:start position:0% +just let's take the easiest matrix the +identity if I look for its eigenvalues + + align:start position:0% +identity if I look for its eigenvalues + + + align:start position:0% +identity if I look for its eigenvalues +they're all ones so that eigenvalue one + + align:start position:0% +they're all ones so that eigenvalue one + + + align:start position:0% +they're all ones so that eigenvalue one +is repeated ten times but there's no + + align:start position:0% +is repeated ten times but there's no + + + align:start position:0% +is repeated ten times but there's no +shortage of eigenvectors for the + + align:start position:0% +shortage of eigenvectors for the + + + align:start position:0% +shortage of eigenvectors for the +identity matrix in fact every vector is + + align:start position:0% +identity matrix in fact every vector is + + + align:start position:0% +identity matrix in fact every vector is +an eigenvector so i can take ten + + align:start position:0% +an eigenvector so i can take ten + + + align:start position:0% +an eigenvector so i can take ten +independent vectors oh well what happens + + align:start position:0% +independent vectors oh well what happens + + + align:start position:0% +independent vectors oh well what happens +to everything if a is the identity + + align:start position:0% +to everything if a is the identity + + + align:start position:0% +to everything if a is the identity +matrix let's just think that one through + + align:start position:0% +matrix let's just think that one through + + + align:start position:0% +matrix let's just think that one through +in our head if a is the identity matrix + + align:start position:0% +in our head if a is the identity matrix + + + align:start position:0% +in our head if a is the identity matrix +then it's got plenty of eigenvectors i + + align:start position:0% +then it's got plenty of eigenvectors i + + + align:start position:0% +then it's got plenty of eigenvectors i +choose ten independent vectors they're + + align:start position:0% +choose ten independent vectors they're + + + align:start position:0% +choose ten independent vectors they're +the columns of s and and what do i get + + align:start position:0% +the columns of s and and what do i get + + + align:start position:0% +the columns of s and and what do i get +from s inverse a s i get i again right + + align:start position:0% +from s inverse a s i get i again right + + + align:start position:0% +from s inverse a s i get i again right +if a is the idea and of course that's + + align:start position:0% +if a is the idea and of course that's + + + align:start position:0% +if a is the idea and of course that's +the correct lambda the matrix was + + align:start position:0% +the correct lambda the matrix was + + + align:start position:0% +the correct lambda the matrix was +already diagonal so if the matrix is + + align:start position:0% +already diagonal so if the matrix is + + + align:start position:0% +already diagonal so if the matrix is +already diagonal then the the lambda is + + align:start position:0% +already diagonal then the the lambda is + + + align:start position:0% +already diagonal then the the lambda is +the same as the matrix a diagonal matrix + + align:start position:0% +the same as the matrix a diagonal matrix + + + align:start position:0% +the same as the matrix a diagonal matrix +has got its eigenvalues sitting right + + align:start position:0% +has got its eigenvalues sitting right + + + align:start position:0% +has got its eigenvalues sitting right +there in + + align:start position:0% +there in + + + align:start position:0% +there in +front of you now if it's triangular the + + align:start position:0% +front of you now if it's triangular the + + + align:start position:0% +front of you now if it's triangular the +eigenvalues are still sitting there but + + align:start position:0% +eigenvalues are still sitting there but + + + align:start position:0% +eigenvalues are still sitting there but +so let's let's take a case where it's + + align:start position:0% +so let's let's take a case where it's + + + align:start position:0% +so let's let's take a case where it's +triangular suppose a is like 2 1 2 0 so + + align:start position:0% +triangular suppose a is like 2 1 2 0 so + + + align:start position:0% +triangular suppose a is like 2 1 2 0 so +there's a case that's going to be + + align:start position:0% +there's a case that's going to be + + + align:start position:0% +there's a case that's going to be +trouble there's a case that's going to + + align:start position:0% +trouble there's a case that's going to + + + align:start position:0% +trouble there's a case that's going to +be trouble + + align:start position:0% +be trouble + + + align:start position:0% +be trouble +first of all what are the eigen value if + + align:start position:0% +first of all what are the eigen value if + + + align:start position:0% +first of all what are the eigen value if +we start with a matrix the first thing + + align:start position:0% +we start with a matrix the first thing + + + align:start position:0% +we start with a matrix the first thing +we do will practically without thinking + + align:start position:0% +we do will practically without thinking + + + align:start position:0% +we do will practically without thinking +is compute the eigenvalues and + + align:start position:0% +is compute the eigenvalues and + + + align:start position:0% +is compute the eigenvalues and +eigenvectors okay so what are the + + align:start position:0% +eigenvectors okay so what are the + + + align:start position:0% +eigenvectors okay so what are the +eigenvalues you can tell me right away + + align:start position:0% +eigenvalues you can tell me right away + + + align:start position:0% +eigenvalues you can tell me right away +what they are they're two and two right + + align:start position:0% +what they are they're two and two right + + + align:start position:0% +what they are they're two and two right +it's a triangular matrix so when I do + + align:start position:0% +it's a triangular matrix so when I do + + + align:start position:0% +it's a triangular matrix so when I do +this determinant shall I do this + + align:start position:0% +this determinant shall I do this + + + align:start position:0% +this determinant shall I do this +determinant of a minus lambda I I'll get + + align:start position:0% +determinant of a minus lambda I I'll get + + + align:start position:0% +determinant of a minus lambda I I'll get +this 2 minus lambda 1 0 2 minus lambda + + align:start position:0% +this 2 minus lambda 1 0 2 minus lambda + + + align:start position:0% +this 2 minus lambda 1 0 2 minus lambda +right I take that determinant so I make + + align:start position:0% +right I take that determinant so I make + + + align:start position:0% +right I take that determinant so I make +those into vertical bars to mean + + align:start position:0% +those into vertical bars to mean + + + align:start position:0% +those into vertical bars to mean +determinant and what's the determinant + + align:start position:0% +determinant and what's the determinant + + + align:start position:0% +determinant and what's the determinant +to minus lambda square what are the + + align:start position:0% +to minus lambda square what are the + + + align:start position:0% +to minus lambda square what are the +roots lambda equal to twice so the + + align:start position:0% +roots lambda equal to twice so the + + + align:start position:0% +roots lambda equal to twice so the +eigenvalues are lambda equals 2 and 2 + + align:start position:0% +eigenvalues are lambda equals 2 and 2 + + + align:start position:0% +eigenvalues are lambda equals 2 and 2 +okay fine + + align:start position:0% +okay fine + + + align:start position:0% +okay fine +now the next step find the eigenvectors + + align:start position:0% +now the next step find the eigenvectors + + + align:start position:0% +now the next step find the eigenvectors +so i hope for eigenvectors and what do I + + align:start position:0% +so i hope for eigenvectors and what do I + + + align:start position:0% +so i hope for eigenvectors and what do I +find for this guy + + align:start position:0% +find for this guy + + + align:start position:0% +find for this guy +I can Victor's for this guy when I + + align:start position:0% +I can Victor's for this guy when I + + + align:start position:0% +I can Victor's for this guy when I +subtract 2 minus the identity so a minus + + align:start position:0% +subtract 2 minus the identity so a minus + + + align:start position:0% +subtract 2 minus the identity so a minus +2 I as zeros here and I'm looking for + + align:start position:0% +2 I as zeros here and I'm looking for + + + align:start position:0% +2 I as zeros here and I'm looking for +the null space what's what are the + + align:start position:0% +the null space what's what are the + + + align:start position:0% +the null space what's what are the +eigenvectors + + align:start position:0% +eigenvectors + + + align:start position:0% +eigenvectors +they're there they're the null space of + + align:start position:0% +they're there they're the null space of + + + align:start position:0% +they're there they're the null space of +a minus lambda up the null space is only + + align:start position:0% +a minus lambda up the null space is only + + + align:start position:0% +a minus lambda up the null space is only +one dimension this is a case where I + + align:start position:0% +one dimension this is a case where I + + + align:start position:0% +one dimension this is a case where I +don't have enough eigenvectors my + + align:start position:0% +don't have enough eigenvectors my + + + align:start position:0% +don't have enough eigenvectors my +algebra + + align:start position:0% +algebra + + + align:start position:0% +algebra +simplicity is - I would say when I see + + align:start position:0% +simplicity is - I would say when I see + + + align:start position:0% +simplicity is - I would say when I see +when I count how often the eigenvalue is + + align:start position:0% +when I count how often the eigenvalue is + + + align:start position:0% +when I count how often the eigenvalue is +repeated + + align:start position:0% + + + + align:start position:0% + +that's the algebraic multiplicity + + align:start position:0% +that's the algebraic multiplicity + + + align:start position:0% +that's the algebraic multiplicity +that's the multiplicity how many times + + align:start position:0% +that's the multiplicity how many times + + + align:start position:0% +that's the multiplicity how many times +is it the root of the polynomial my + + align:start position:0% +is it the root of the polynomial my + + + align:start position:0% +is it the root of the polynomial my +polynomial is 2 minus lambda square it's + + align:start position:0% +polynomial is 2 minus lambda square it's + + + align:start position:0% +polynomial is 2 minus lambda square it's +a double root + + align:start position:0% +a double root + + + align:start position:0% +a double root +so my algebraic multiplicity is 2 but + + align:start position:0% +so my algebraic multiplicity is 2 but + + + align:start position:0% +so my algebraic multiplicity is 2 but +the geometric multiplicity which looks + + align:start position:0% +the geometric multiplicity which looks + + + align:start position:0% +the geometric multiplicity which looks +for vectors looks for eigenvectors and + + align:start position:0% +for vectors looks for eigenvectors and + + + align:start position:0% +for vectors looks for eigenvectors and +which means the null space of this thing + + align:start position:0% +which means the null space of this thing + + + align:start position:0% +which means the null space of this thing +and the only eigenvector is 1 0 that's + + align:start position:0% +and the only eigenvector is 1 0 that's + + + align:start position:0% +and the only eigenvector is 1 0 that's +in the null space 0 1 is not in the null + + align:start position:0% +in the null space 0 1 is not in the null + + + align:start position:0% +in the null space 0 1 is not in the null +space the null space is only one + + align:start position:0% +space the null space is only one + + + align:start position:0% +space the null space is only one +dimensional so there is a matrix my this + + align:start position:0% +dimensional so there is a matrix my this + + + align:start position:0% +dimensional so there is a matrix my this +a or the original a that are not + + align:start position:0% +a or the original a that are not + + + align:start position:0% +a or the original a that are not +diagonalizable I can't I can't find two + + align:start position:0% +diagonalizable I can't I can't find two + + + align:start position:0% +diagonalizable I can't I can't find two +independent eigenvectors there's only + + align:start position:0% +independent eigenvectors there's only + + + align:start position:0% +independent eigenvectors there's only +one okay so that's the case that I'm + + align:start position:0% +one okay so that's the case that I'm + + + align:start position:0% +one okay so that's the case that I'm +that's a case that I I'm not really + + align:start position:0% +that's a case that I I'm not really + + + align:start position:0% +that's a case that I I'm not really +handling for example when I wrote down + + align:start position:0% +handling for example when I wrote down + + + align:start position:0% +handling for example when I wrote down +up here that the powers went to 0 if the + + align:start position:0% +up here that the powers went to 0 if the + + + align:start position:0% +up here that the powers went to 0 if the +eigen guys were below 1 I didn't really + + align:start position:0% +eigen guys were below 1 I didn't really + + + align:start position:0% +eigen guys were below 1 I didn't really +handle that case of repeated eigen + + align:start position:0% +handle that case of repeated eigen + + + align:start position:0% +handle that case of repeated eigen +values because my reasoning was based on + + align:start position:0% +values because my reasoning was based on + + + align:start position:0% +values because my reasoning was based on +this form and this formula is based on n + + align:start position:0% +this form and this formula is based on n + + + align:start position:0% +this form and this formula is based on n +independent eigenvectors ok so just this + + align:start position:0% +independent eigenvectors ok so just this + + + align:start position:0% +independent eigenvectors ok so just this +just to say there are some matrices that + + align:start position:0% +just to say there are some matrices that + + + align:start position:0% +just to say there are some matrices that +we that we don't cover through + + align:start position:0% +we that we don't cover through + + + align:start position:0% +we that we don't cover through +diagonalization but the great majority + + align:start position:0% +diagonalization but the great majority + + + align:start position:0% +diagonalization but the great majority +we do okay and we're always okay if we + + align:start position:0% +we do okay and we're always okay if we + + + align:start position:0% +we do okay and we're always okay if we +have different distinct eigen oh okay + + align:start position:0% +have different distinct eigen oh okay + + + align:start position:0% +have different distinct eigen oh okay +that's like the typical case because for + + align:start position:0% +that's like the typical case because for + + + align:start position:0% +that's like the typical case because for +each eigen value there's at least one + + align:start position:0% +each eigen value there's at least one + + + align:start position:0% +each eigen value there's at least one +eigenvector the algebraic multiplicity + + align:start position:0% +eigenvector the algebraic multiplicity + + + align:start position:0% +eigenvector the algebraic multiplicity +one for every eigenvalue and the + + align:start position:0% +one for every eigenvalue and the + + + align:start position:0% +one for every eigenvalue and the +geometric multiplicity is 1 there's one + + align:start position:0% +geometric multiplicity is 1 there's one + + + align:start position:0% +geometric multiplicity is 1 there's one +eigenvector and they are independent + + align:start position:0% +eigenvector and they are independent + + + align:start position:0% +eigenvector and they are independent +okay okay now let me come back to the + + align:start position:0% +okay okay now let me come back to the + + + align:start position:0% +okay okay now let me come back to the +important case when when we're okay the + + align:start position:0% +important case when when we're okay the + + + align:start position:0% +important case when when we're okay the +important case when we are dying light + + align:start position:0% +important case when we are dying light + + + align:start position:0% +important case when we are dying light +let me look at so so so a quick let me + + align:start position:0% +let me look at so so so a quick let me + + + align:start position:0% +let me look at so so so a quick let me +solve this equation the equation will be + + align:start position:0% +solve this equation the equation will be + + + align:start position:0% +solve this equation the equation will be +each I start with some start with a + + align:start position:0% +each I start with some start with a + + + align:start position:0% +each I start with some start with a +given vector u0 and then my equation is + + align:start position:0% +given vector u0 and then my equation is + + + align:start position:0% +given vector u0 and then my equation is +that every step I multiply what I have + + align:start position:0% +that every step I multiply what I have + + + align:start position:0% +that every step I multiply what I have +by a I then then equation ought to be + + align:start position:0% +by a I then then equation ought to be + + + align:start position:0% +by a I then then equation ought to be +simple to handle and I'd like to be able + + align:start position:0% +simple to handle and I'd like to be able + + + align:start position:0% +simple to handle and I'd like to be able +to solve how would I find if I start + + align:start position:0% +to solve how would I find if I start + + + align:start position:0% +to solve how would I find if I start +with a vector you know it and I multiply + + align:start position:0% +with a vector you know it and I multiply + + + align:start position:0% +with a vector you know it and I multiply +by a a hundred times what if I got what + + align:start position:0% +by a a hundred times what if I got what + + + align:start position:0% +by a a hundred times what if I got what +I certainly write down a formula for the + + align:start position:0% +I certainly write down a formula for the + + + align:start position:0% +I certainly write down a formula for the +answer so what what so u1 is a you know + + align:start position:0% +answer so what what so u1 is a you know + + + align:start position:0% +answer so what what so u1 is a you know +and u2 is what's you to then you to I + + align:start position:0% +and u2 is what's you to then you to I + + + align:start position:0% +and u2 is what's you to then you to I +multiply u2 I get from you one by + + align:start position:0% +multiply u2 I get from you one by + + + align:start position:0% +multiply u2 I get from you one by +another multiplying by a so I've been a + + align:start position:0% +another multiplying by a so I've been a + + + align:start position:0% +another multiplying by a so I've been a +twice and my formula is you K after K + + align:start position:0% +twice and my formula is you K after K + + + align:start position:0% +twice and my formula is you K after K +steps I multiplied by a K times the + + align:start position:0% +steps I multiplied by a K times the + + + align:start position:0% +steps I multiplied by a K times the +original you know you see what I'm doing + + align:start position:0% +original you know you see what I'm doing + + + align:start position:0% +original you know you see what I'm doing +the next section is going to solve + + align:start position:0% +the next section is going to solve + + + align:start position:0% +the next section is going to solve +systems of + + align:start position:0% +systems of + + + align:start position:0% +systems of +rental equation I'm going to have + + align:start position:0% +rental equation I'm going to have + + + align:start position:0% +rental equation I'm going to have +derivative this this section is the nice + + align:start position:0% +derivative this this section is the nice + + + align:start position:0% +derivative this this section is the nice +one it's all difference equations I + + align:start position:0% +one it's all difference equations I + + + align:start position:0% +one it's all difference equations I +would call that a difference equation + + align:start position:0% +would call that a difference equation + + + align:start position:0% +would call that a difference equation +it's kinetic first-order I would call + + align:start position:0% +it's kinetic first-order I would call + + + align:start position:0% +it's kinetic first-order I would call +that a first-order system because it + + align:start position:0% +that a first-order system because it + + + align:start position:0% +that a first-order system because it +connects only it only goes up one level + + align:start position:0% +connects only it only goes up one level + + + align:start position:0% +connects only it only goes up one level +and it's a system because these are + + align:start position:0% +and it's a system because these are + + + align:start position:0% +and it's a system because these are +vectors and that's amazing and the + + align:start position:0% +vectors and that's amazing and the + + + align:start position:0% +vectors and that's amazing and the +solution is just that okay but that's a + + align:start position:0% +solution is just that okay but that's a + + + align:start position:0% +solution is just that okay but that's a +nice formula that's like that most + + align:start position:0% +nice formula that's like that most + + + align:start position:0% +nice formula that's like that most +compact formula I could ever get you + + align:start position:0% +compact formula I could ever get you + + + align:start position:0% +compact formula I could ever get you +what hundreds would be eighty to one + + align:start position:0% +what hundreds would be eighty to one + + + align:start position:0% +what hundreds would be eighty to one +hundred you know but how would I + + align:start position:0% +hundred you know but how would I + + + align:start position:0% +hundred you know but how would I +actually find you one hundred how would + + align:start position:0% +actually find you one hundred how would + + + align:start position:0% +actually find you one hundred how would +I find how would I discover what you 100 + + align:start position:0% +I find how would I discover what you 100 + + + align:start position:0% +I find how would I discover what you 100 +is let me let me show you how here's the + + align:start position:0% +is let me let me show you how here's the + + + align:start position:0% +is let me let me show you how here's the +idea + + align:start position:0% +idea + + + align:start position:0% +idea +if so to solve to really stop shall I + + align:start position:0% +if so to solve to really stop shall I + + + align:start position:0% +if so to solve to really stop shall I +say to really to really solve it I would + + align:start position:0% +say to really to really solve it I would + + + align:start position:0% +say to really to really solve it I would +take this initial vector U naught and I + + align:start position:0% +take this initial vector U naught and I + + + align:start position:0% +take this initial vector U naught and I +would write it as a combination of + + align:start position:0% +would write it as a combination of + + + align:start position:0% +would write it as a combination of +eigenvectors to really solve right right + + align:start position:0% + + + + align:start position:0% + +you not as a combination say certain + + align:start position:0% +you not as a combination say certain + + + align:start position:0% +you not as a combination say certain +amount of the first eigen vector plus is + + align:start position:0% +amount of the first eigen vector plus is + + + align:start position:0% +amount of the first eigen vector plus is +certain + + align:start position:0% +certain + + + align:start position:0% +certain +the second eigenvector plus a certain + + align:start position:0% +the second eigenvector plus a certain + + + align:start position:0% +the second eigenvector plus a certain +amount of the last time now multiply by + + align:start position:0% +amount of the last time now multiply by + + + align:start position:0% +amount of the last time now multiply by +a you want you got to see the magic of + + align:start position:0% +a you want you got to see the magic of + + + align:start position:0% +a you want you got to see the magic of +eigenvectors working multiplied by a so + + align:start position:0% +eigenvectors working multiplied by a so + + + align:start position:0% +eigenvectors working multiplied by a so +a you know is what so a times that a + + align:start position:0% +a you know is what so a times that a + + + align:start position:0% +a you know is what so a times that a +times so what I can separate it out into + + align:start position:0% +times so what I can separate it out into + + + align:start position:0% +times so what I can separate it out into +n separate pieces and that's the whole + + align:start position:0% +n separate pieces and that's the whole + + + align:start position:0% +n separate pieces and that's the whole +point that each of those pieces is going + + align:start position:0% +point that each of those pieces is going + + + align:start position:0% +point that each of those pieces is going +in its own merry way each of those + + align:start position:0% +in its own merry way each of those + + + align:start position:0% +in its own merry way each of those +pieces is an eigenvector and when I + + align:start position:0% +pieces is an eigenvector and when I + + + align:start position:0% +pieces is an eigenvector and when I +multiply by a what is this piece become + + align:start position:0% +multiply by a what is this piece become + + + align:start position:0% +multiply by a what is this piece become +so that's some amount of the first let's + + align:start position:0% +so that's some amount of the first let's + + + align:start position:0% +so that's some amount of the first let's +suppose the eigenvectors are normalized + + align:start position:0% +suppose the eigenvectors are normalized + + + align:start position:0% +suppose the eigenvectors are normalized +to be unit vectors so that says what the + + align:start position:0% +to be unit vectors so that says what the + + + align:start position:0% +to be unit vectors so that says what the +eigenvector is and I need some multiple + + align:start position:0% +eigenvector is and I need some multiple + + + align:start position:0% +eigenvector is and I need some multiple +of it to produce you know okay now when + + align:start position:0% +of it to produce you know okay now when + + + align:start position:0% +of it to produce you know okay now when +I multiply by a what do I get I get c1 + + align:start position:0% +I multiply by a what do I get I get c1 + + + align:start position:0% +I multiply by a what do I get I get c1 +which is just a factor times ax 1 but + + align:start position:0% +which is just a factor times ax 1 but + + + align:start position:0% +which is just a factor times ax 1 but +they X 1 is lambda 1 X 1 when I multiply + + align:start position:0% +they X 1 is lambda 1 X 1 when I multiply + + + align:start position:0% +they X 1 is lambda 1 X 1 when I multiply +this by a I get C 2 lambda 2 X 2 and + + align:start position:0% +this by a I get C 2 lambda 2 X 2 and + + + align:start position:0% +this by a I get C 2 lambda 2 X 2 and +here I get C n lambda n + + align:start position:0% +here I get C n lambda n + + + align:start position:0% +here I get C n lambda n +and suppose I multiply by a to the + + align:start position:0% +and suppose I multiply by a to the + + + align:start position:0% +and suppose I multiply by a to the +hundredth power now can we can we having + + align:start position:0% +hundredth power now can we can we having + + + align:start position:0% +hundredth power now can we can we having +done it multiplied by a let's multiply + + align:start position:0% +done it multiplied by a let's multiply + + + align:start position:0% +done it multiplied by a let's multiply +by a to the hundredth what happens to + + align:start position:0% +by a to the hundredth what happens to + + + align:start position:0% +by a to the hundredth what happens to +this first term when I multiply by a to + + align:start position:0% +this first term when I multiply by a to + + + align:start position:0% +this first term when I multiply by a to +the 100 it's got that factor lambda to + + align:start position:0% +the 100 it's got that factor lambda to + + + align:start position:0% +the 100 it's got that factor lambda to +the hundredth that's the key that that's + + align:start position:0% +the hundredth that's the key that that's + + + align:start position:0% +the hundredth that's the key that that's +what I mean by going its own merry way + + align:start position:0% +what I mean by going its own merry way + + + align:start position:0% +what I mean by going its own merry way +if it is pure eigenvector it's exactly + + align:start position:0% +if it is pure eigenvector it's exactly + + + align:start position:0% +if it is pure eigenvector it's exactly +in a direction where multiplication by a + + align:start position:0% +in a direction where multiplication by a + + + align:start position:0% +in a direction where multiplication by a +just brings in a scalar factor lambda + + align:start position:0% +just brings in a scalar factor lambda + + + align:start position:0% +just brings in a scalar factor lambda +one so a hundred times brings in this + + align:start position:0% +one so a hundred times brings in this + + + align:start position:0% +one so a hundred times brings in this +100 times a hundred times lambda 200 + + align:start position:0% +100 times a hundred times lambda 200 + + + align:start position:0% +100 times a hundred times lambda 200 +times lambda n actually what are we + + align:start position:0% +times lambda n actually what are we + + + align:start position:0% +times lambda n actually what are we +seeing here we're seeing this same + + align:start position:0% +seeing here we're seeing this same + + + align:start position:0% +seeing here we're seeing this same +lambda capital lambda to the hundredth + + align:start position:0% +lambda capital lambda to the hundredth + + + align:start position:0% +lambda capital lambda to the hundredth +as in the as in the diagonalization and + + align:start position:0% +as in the as in the diagonalization and + + + align:start position:0% +as in the as in the diagonalization and +we're seeing the S matrix that matrix s + + align:start position:0% +we're seeing the S matrix that matrix s + + + align:start position:0% +we're seeing the S matrix that matrix s +of eigenvector that's what this has got + + align:start position:0% +of eigenvector that's what this has got + + + align:start position:0% +of eigenvector that's what this has got +this has got to amount to a lambda to + + align:start position:0% +this has got to amount to a lambda to + + + align:start position:0% +this has got to amount to a lambda to +the hundredth power times and s times + + align:start position:0% +the hundredth power times and s times + + + align:start position:0% +the hundredth power times and s times +this vector C that's telling us how much + + align:start position:0% +this vector C that's telling us how much + + + align:start position:0% +this vector C that's telling us how much +of each one is in the original thing so + + align:start position:0% +of each one is in the original thing so + + + align:start position:0% +of each one is in the original thing so +if I had to really find a hundredth + + align:start position:0% +if I had to really find a hundredth + + + align:start position:0% +if I had to really find a hundredth +power I would take you not I would + + align:start position:0% +power I would take you not I would + + + align:start position:0% +power I would take you not I would +expand it as a combination of + + align:start position:0% +expand it as a combination of + + + align:start position:0% +expand it as a combination of +eigenvectors this is really s the + + align:start position:0% +eigenvectors this is really s the + + + align:start position:0% +eigenvectors this is really s the +eigenvector matrix times C the + + align:start position:0% +eigenvector matrix times C the + + + align:start position:0% +eigenvector matrix times C the +coefficient vector and then I would + + align:start position:0% +coefficient vector and then I would + + + align:start position:0% +coefficient vector and then I would +immediately did by inserting these + + align:start position:0% +immediately did by inserting these + + + align:start position:0% +immediately did by inserting these +hundreds powers of eigenvalues I'd have + + align:start position:0% +hundreds powers of eigenvalues I'd have + + + align:start position:0% +hundreds powers of eigenvalues I'd have +the answer so the the up there must be + + align:start position:0% +the answer so the the up there must be + + + align:start position:0% +the answer so the the up there must be +let's see okay it's so yeah so if you + + align:start position:0% +let's see okay it's so yeah so if you + + + align:start position:0% +let's see okay it's so yeah so if you +100 is + + align:start position:0% +100 is + + + align:start position:0% +100 is +one hundred times you know and you know + + align:start position:0% +one hundred times you know and you know + + + align:start position:0% +one hundred times you know and you know +it is SC then you see this formula is + + align:start position:0% +it is SC then you see this formula is + + + align:start position:0% +it is SC then you see this formula is +just this formula which is the way I + + align:start position:0% +just this formula which is the way I + + + align:start position:0% +just this formula which is the way I +would actually get hold of this of this + + align:start position:0% +would actually get hold of this of this + + + align:start position:0% +would actually get hold of this of this +you 100 which is let me put it here you + + align:start position:0% +you 100 which is let me put it here you + + + align:start position:0% +you 100 which is let me put it here you +100 the way right the way I would + + align:start position:0% +100 the way right the way I would + + + align:start position:0% +100 the way right the way I would +actually get hold of that see what what + + align:start position:0% +actually get hold of that see what what + + + align:start position:0% +actually get hold of that see what what +the solution is after a hundred steps + + align:start position:0% +the solution is after a hundred steps + + + align:start position:0% +the solution is after a hundred steps +would be expand the initial vector into + + align:start position:0% +would be expand the initial vector into + + + align:start position:0% +would be expand the initial vector into +eigenvectors and up and let each + + align:start position:0% +eigenvectors and up and let each + + + align:start position:0% +eigenvectors and up and let each +eigenvector go its own way multiplying + + align:start position:0% +eigenvector go its own way multiplying + + + align:start position:0% +eigenvector go its own way multiplying +by a hundred by lambda at every step and + + align:start position:0% +by a hundred by lambda at every step and + + + align:start position:0% +by a hundred by lambda at every step and +therefore by lambda to the hundredth + + align:start position:0% +therefore by lambda to the hundredth + + + align:start position:0% +therefore by lambda to the hundredth +power after a hundred steps can I do + + align:start position:0% +power after a hundred steps can I do + + + align:start position:0% +power after a hundred steps can I do +anything + + align:start position:0% +anything + + + align:start position:0% +anything +so that's that's the the formulas now + + align:start position:0% +so that's that's the the formulas now + + + align:start position:0% +so that's that's the the formulas now +let me take an example I'll use the + + align:start position:0% +let me take an example I'll use the + + + align:start position:0% +let me take an example I'll use the +Fibonacci sequence as an example so so + + align:start position:0% +Fibonacci sequence as an example so so + + + align:start position:0% +Fibonacci sequence as an example so so +Fibonacci example you remember the + + align:start position:0% +Fibonacci example you remember the + + + align:start position:0% +Fibonacci example you remember the +Fibonacci numbers if we start with 1 and + + align:start position:0% +Fibonacci numbers if we start with 1 and + + + align:start position:0% +Fibonacci numbers if we start with 1 and +1 as f naught oh I think I start with 0 + + align:start position:0% +1 as f naught oh I think I start with 0 + + + align:start position:0% +1 as f naught oh I think I start with 0 +that's 0 and 1 be the first + + align:start position:0% +that's 0 and 1 be the first + + + align:start position:0% +that's 0 and 1 be the first +so there's F 0 and F 1 first to 7rg + + align:start position:0% +so there's F 0 and F 1 first to 7rg + + + align:start position:0% +so there's F 0 and F 1 first to 7rg +numbers and what's the rule for + + align:start position:0% +numbers and what's the rule for + + + align:start position:0% +numbers and what's the rule for +Fibonacci numbers I'm there the Sun the + + align:start position:0% +Fibonacci numbers I'm there the Sun the + + + align:start position:0% +Fibonacci numbers I'm there the Sun the +next one is the sum of those so it's 1 + + align:start position:0% +next one is the sum of those so it's 1 + + + align:start position:0% +next one is the sum of those so it's 1 +the next one is the sum of those so it's + + align:start position:0% +the next one is the sum of those so it's + + + align:start position:0% +the next one is the sum of those so it's +2 the next one is the sum of those so + + align:start position:0% +2 the next one is the sum of those so + + + align:start position:0% +2 the next one is the sum of those so +it's 3 well it looks like 1 2 3 4 5 but + + align:start position:0% +it's 3 well it looks like 1 2 3 4 5 but + + + align:start position:0% +it's 3 well it looks like 1 2 3 4 5 but +somehow it's not going to do that way + + align:start position:0% +somehow it's not going to do that way + + + align:start position:0% +somehow it's not going to do that way +the next one is 5 right 2 or 3 makes 5 + + align:start position:0% +the next one is 5 right 2 or 3 makes 5 + + + align:start position:0% +the next one is 5 right 2 or 3 makes 5 +the next one is 8 the next one is 13 and + + align:start position:0% +the next one is 8 the next one is 13 and + + + align:start position:0% +the next one is 8 the next one is 13 and +the 107 odd + + align:start position:0% +the 107 odd + + + align:start position:0% +the 107 odd +number is one that's my question + + align:start position:0% +number is one that's my question + + + align:start position:0% +number is one that's my question +how could I get a formula for the + + align:start position:0% +how could I get a formula for the + + + align:start position:0% +how could I get a formula for the +hundredth number and and for example how + + align:start position:0% +hundredth number and and for example how + + + align:start position:0% +hundredth number and and for example how +could I answer the question how fast are + + align:start position:0% +could I answer the question how fast are + + + align:start position:0% +could I answer the question how fast are +they growing how fast are those + + align:start position:0% +they growing how fast are those + + + align:start position:0% +they growing how fast are those +Fibonacci numbers growing they're + + align:start position:0% +Fibonacci numbers growing they're + + + align:start position:0% +Fibonacci numbers growing they're +certainly growing it's not a stable case + + align:start position:0% +certainly growing it's not a stable case + + + align:start position:0% +certainly growing it's not a stable case +whatever the eigenvalues of whatever + + align:start position:0% +whatever the eigenvalues of whatever + + + align:start position:0% +whatever the eigenvalues of whatever +matrix it is they're not smaller than + + align:start position:0% +matrix it is they're not smaller than + + + align:start position:0% +matrix it is they're not smaller than +one these numbers are growing but how + + align:start position:0% +one these numbers are growing but how + + + align:start position:0% +one these numbers are growing but how +fast are they growing the answer is is + + align:start position:0% +fast are they growing the answer is is + + + align:start position:0% +fast are they growing the answer is is +lies in the eigenvalue + + align:start position:0% +lies in the eigenvalue + + + align:start position:0% +lies in the eigenvalue +so I've got to find the matrix let me + + align:start position:0% +so I've got to find the matrix let me + + + align:start position:0% +so I've got to find the matrix let me +write down the Fibonacci rule FK plus 2 + + align:start position:0% +write down the Fibonacci rule FK plus 2 + + + align:start position:0% +write down the Fibonacci rule FK plus 2 +is f k plus 1 plus f k right now that's + + align:start position:0% +is f k plus 1 plus f k right now that's + + + align:start position:0% +is f k plus 1 plus f k right now that's +not in my I want to write that as u k + + align:start position:0% +not in my I want to write that as u k + + + align:start position:0% +not in my I want to write that as u k +plus 1 and a UK but right now what I've + + align:start position:0% +plus 1 and a UK but right now what I've + + + align:start position:0% +plus 1 and a UK but right now what I've +got is a single equation not a system + + align:start position:0% +got is a single equation not a system + + + align:start position:0% +got is a single equation not a system +and it's second order it's like having a + + align:start position:0% +and it's second order it's like having a + + + align:start position:0% +and it's second order it's like having a +second order differential equation with + + align:start position:0% +second order differential equation with + + + align:start position:0% +second order differential equation with +second derivative I want to get first + + align:start position:0% +second derivative I want to get first + + + align:start position:0% +second derivative I want to get first +derivatives here I want to get first + + align:start position:0% +derivatives here I want to get first + + + align:start position:0% +derivatives here I want to get first +difference so the way the way to do it + + align:start position:0% +difference so the way the way to do it + + + align:start position:0% +difference so the way the way to do it +is to effuse UK will be a vector see it + + align:start position:0% +is to effuse UK will be a vector see it + + + align:start position:0% +is to effuse UK will be a vector see it +a small trick let that UK be a vector F + + align:start position:0% +a small trick let that UK be a vector F + + + align:start position:0% +a small trick let that UK be a vector F +k plus 1 and F K so I'm going to get a 2 + + align:start position:0% +k plus 1 and F K so I'm going to get a 2 + + + align:start position:0% +k plus 1 and F K so I'm going to get a 2 +by 2 system first order instead of a 1 + + align:start position:0% +by 2 system first order instead of a 1 + + + align:start position:0% +by 2 system first order instead of a 1 +instead of a scalar system second-order + + align:start position:0% +instead of a scalar system second-order + + + align:start position:0% +instead of a scalar system second-order +by a simple trick I'm just going to have + + align:start position:0% +by a simple trick I'm just going to have + + + align:start position:0% +by a simple trick I'm just going to have +in an equation FK plus 1 equals FK plus + + align:start position:0% +in an equation FK plus 1 equals FK plus + + + align:start position:0% +in an equation FK plus 1 equals FK plus +1 that will be my second equation then + + align:start position:0% +1 that will be my second equation then + + + align:start position:0% +1 that will be my second equation then +this is my system this is my unknown and + + align:start position:0% +this is my system this is my unknown and + + + align:start position:0% +this is my system this is my unknown and +what's my one-step equation so so now UK + + align:start position:0% +what's my one-step equation so so now UK + + + align:start position:0% +what's my one-step equation so so now UK +plus 1 that's so UK plus 1 is the left + + align:start position:0% +plus 1 that's so UK plus 1 is the left + + + align:start position:0% +plus 1 that's so UK plus 1 is the left +side and what have I got here on the + + align:start position:0% +side and what have I got here on the + + + align:start position:0% +side and what have I got here on the +right side I've got some matrix + + align:start position:0% +right side I've got some matrix + + + align:start position:0% +right side I've got some matrix +multiplying UK can you see that alright + + align:start position:0% +multiplying UK can you see that alright + + + align:start position:0% +multiplying UK can you see that alright +if you can see it then you can tell me + + align:start position:0% +if you can see it then you can tell me + + + align:start position:0% +if you can see it then you can tell me +what the matrix is + + align:start position:0% +what the matrix is + + + align:start position:0% +what the matrix is +do you see that I'm taking my system + + align:start position:0% +do you see that I'm taking my system + + + align:start position:0% +do you see that I'm taking my system +here artificially made it into a system + + align:start position:0% +here artificially made it into a system + + + align:start position:0% +here artificially made it into a system +I artificially made the unknown into a + + align:start position:0% +I artificially made the unknown into a + + + align:start position:0% +I artificially made the unknown into a +vector and now I'm ready to look at and + + align:start position:0% +vector and now I'm ready to look at and + + + align:start position:0% +vector and now I'm ready to look at and +see what the matrix so do you see the + + align:start position:0% +see what the matrix so do you see the + + + align:start position:0% +see what the matrix so do you see the +left side UK plus 1 is FK + 2 FK plus 1 + + align:start position:0% +left side UK plus 1 is FK + 2 FK plus 1 + + + align:start position:0% +left side UK plus 1 is FK + 2 FK plus 1 +that's just what I want on the right + + align:start position:0% +that's just what I want on the right + + + align:start position:0% +that's just what I want on the right +side this remember this UK here I mean + + align:start position:0% +side this remember this UK here I mean + + + align:start position:0% +side this remember this UK here I mean +for the moment put it as FK plus 1 FK so + + align:start position:0% +for the moment put it as FK plus 1 FK so + + + align:start position:0% +for the moment put it as FK plus 1 FK so +what's the matrix well that is a 1 and a + + align:start position:0% +what's the matrix well that is a 1 and a + + + align:start position:0% +what's the matrix well that is a 1 and a +1 and that has a 1 and a 0 + + align:start position:0% +1 and that has a 1 and a 0 + + + align:start position:0% +1 and that has a 1 and a 0 +there's the matrix you see that that + + align:start position:0% +there's the matrix you see that that + + + align:start position:0% +there's the matrix you see that that +gives me the right hand set so there's + + align:start position:0% +gives me the right hand set so there's + + + align:start position:0% +gives me the right hand set so there's +the matrix a and this is our friend UK + + align:start position:0% +the matrix a and this is our friend UK + + + align:start position:0% +the matrix a and this is our friend UK +so we've got so that simple trick would + + align:start position:0% +so we've got so that simple trick would + + + align:start position:0% +so we've got so that simple trick would +change the second order scalar problem + + align:start position:0% +change the second order scalar problem + + + align:start position:0% +change the second order scalar problem +to a first order system - but with two + + align:start position:0% +to a first order system - but with two + + + align:start position:0% +to a first order system - but with two +unknowns with a matrix and now what do I + + align:start position:0% +unknowns with a matrix and now what do I + + + align:start position:0% +unknowns with a matrix and now what do I +do + + align:start position:0% +do + + + align:start position:0% +do +well before I even think I find its + + align:start position:0% +well before I even think I find its + + + align:start position:0% +well before I even think I find its +eigen values and eigen values so what + + align:start position:0% +eigen values and eigen values so what + + + align:start position:0% +eigen values and eigen values so what +are the eigen values and I + + align:start position:0% +are the eigen values and I + + + align:start position:0% +are the eigen values and I +that mate that's the Iowa's first let me + + align:start position:0% +that mate that's the Iowa's first let me + + + align:start position:0% +that mate that's the Iowa's first let me +just like think for a minute + + align:start position:0% +just like think for a minute + + + align:start position:0% +just like think for a minute +it's two by two so this shouldn't be + + align:start position:0% +it's two by two so this shouldn't be + + + align:start position:0% +it's two by two so this shouldn't be +impossible to do let's do it okay so my + + align:start position:0% +impossible to do let's do it okay so my + + + align:start position:0% +impossible to do let's do it okay so my +matrix again is one one one zero it's + + align:start position:0% +matrix again is one one one zero it's + + + align:start position:0% +matrix again is one one one zero it's +symmetric by the way so what I will + + align:start position:0% +symmetric by the way so what I will + + + align:start position:0% +symmetric by the way so what I will +eventually know about symmetric matrices + + align:start position:0% +eventually know about symmetric matrices + + + align:start position:0% +eventually know about symmetric matrices +is that the eigenvalues will come out + + align:start position:0% +is that the eigenvalues will come out + + + align:start position:0% +is that the eigenvalues will come out +real I won't get any complex numbers + + align:start position:0% +real I won't get any complex numbers + + + align:start position:0% +real I won't get any complex numbers +here and the eigenvectors once I get + + align:start position:0% +here and the eigenvectors once I get + + + align:start position:0% +here and the eigenvectors once I get +those actually will be orthogonal but + + align:start position:0% +those actually will be orthogonal but + + + align:start position:0% +those actually will be orthogonal but +2x2 I'm more interested in what the + + align:start position:0% +2x2 I'm more interested in what the + + + align:start position:0% +2x2 I'm more interested in what the +actual numbers are what do I know about + + align:start position:0% +actual numbers are what do I know about + + + align:start position:0% +actual numbers are what do I know about +those two numbers what should it do you + + align:start position:0% +those two numbers what should it do you + + + align:start position:0% +those two numbers what should it do you +want me to find this determinant of a + + align:start position:0% +want me to find this determinant of a + + + align:start position:0% +want me to find this determinant of a +minus lambda hi sure so it's the + + align:start position:0% +minus lambda hi sure so it's the + + + align:start position:0% +minus lambda hi sure so it's the +determinant of 1 minus lambda 1 1 0 + + align:start position:0% +determinant of 1 minus lambda 1 1 0 + + + align:start position:0% +determinant of 1 minus lambda 1 1 0 +right + + align:start position:0% + + + + align:start position:0% + +minus lambda + + align:start position:0% +minus lambda + + + align:start position:0% +minus lambda +yes okay okay there'll be two + + align:start position:0% +yes okay okay there'll be two + + + align:start position:0% +yes okay okay there'll be two +eigenvectors well tell me again what i + + align:start position:0% +eigenvectors well tell me again what i + + + align:start position:0% +eigenvectors well tell me again what i +know about the two eigenvalues before I + + align:start position:0% +know about the two eigenvalues before I + + + align:start position:0% +know about the two eigenvalues before I +go any further tell me something about + + align:start position:0% +go any further tell me something about + + + align:start position:0% +go any further tell me something about +these two eigenvalues what are they add + + align:start position:0% +these two eigenvalues what are they add + + + align:start position:0% +these two eigenvalues what are they add +up to lambda 1 plus lambda 2 + + align:start position:0% +up to lambda 1 plus lambda 2 + + + align:start position:0% +up to lambda 1 plus lambda 2 +is is the same as the trace down the + + align:start position:0% +is is the same as the trace down the + + + align:start position:0% +is is the same as the trace down the +diagonal of the matrix 1 and 0 is 1 so + + align:start position:0% +diagonal of the matrix 1 and 0 is 1 so + + + align:start position:0% +diagonal of the matrix 1 and 0 is 1 so +lambda 1 plus lambda 2 should come out + + align:start position:0% +lambda 1 plus lambda 2 should come out + + + align:start position:0% +lambda 1 plus lambda 2 should come out +to be 1 and lambda 1 times lambda 2 + + align:start position:0% +to be 1 and lambda 1 times lambda 2 + + + align:start position:0% +to be 1 and lambda 1 times lambda 2 +should come out to be the determinant + + align:start position:0% +should come out to be the determinant + + + align:start position:0% +should come out to be the determinant +which is minus 1 so I'm expecting the + + align:start position:0% +which is minus 1 so I'm expecting the + + + align:start position:0% +which is minus 1 so I'm expecting the +eigenvalues to head to 1 and to multiply + + align:start position:0% +eigenvalues to head to 1 and to multiply + + + align:start position:0% +eigenvalues to head to 1 and to multiply +2 minus 1 but let's just see a happy if + + align:start position:0% +2 minus 1 but let's just see a happy if + + + align:start position:0% +2 minus 1 but let's just see a happy if +I multiply this out I get that times + + align:start position:0% +I multiply this out I get that times + + + align:start position:0% +I multiply this out I get that times +that will be a lambda squared minus + + align:start position:0% +that will be a lambda squared minus + + + align:start position:0% +that will be a lambda squared minus +lambda minus 1 good lambda squared minus + + align:start position:0% +lambda minus 1 good lambda squared minus + + + align:start position:0% +lambda minus 1 good lambda squared minus +lambda minus 1 actually you see the + + align:start position:0% +lambda minus 1 actually you see the + + + align:start position:0% +lambda minus 1 actually you see the +compare that with the original equation + + align:start position:0% +compare that with the original equation + + + align:start position:0% +compare that with the original equation +that I started FK plus 2 minus FK plus 1 + + align:start position:0% +that I started FK plus 2 minus FK plus 1 + + + align:start position:0% +that I started FK plus 2 minus FK plus 1 +minus FK is 0 the the recurrent the + + align:start position:0% +minus FK is 0 the the recurrent the + + + align:start position:0% +minus FK is 0 the the recurrent the +recursion with that be that the + + align:start position:0% +recursion with that be that the + + + align:start position:0% +recursion with that be that the +Fibonacci number satisfied is somehow + + align:start position:0% +Fibonacci number satisfied is somehow + + + align:start position:0% +Fibonacci number satisfied is somehow +showing up directly here for the + + align:start position:0% +showing up directly here for the + + + align:start position:0% +showing up directly here for the +eigenvalues when we set that to 0 okay + + align:start position:0% +eigenvalues when we set that to 0 okay + + + align:start position:0% +eigenvalues when we set that to 0 okay +that's all well I would like to be able + + align:start position:0% +that's all well I would like to be able + + + align:start position:0% +that's all well I would like to be able +to factor that that quadratic but I'm + + align:start position:0% +to factor that that quadratic but I'm + + + align:start position:0% +to factor that that quadratic but I'm +better off to use the quadratic formula + + align:start position:0% +better off to use the quadratic formula + + + align:start position:0% +better off to use the quadratic formula +land that is let's see minus B is 1 plus + + align:start position:0% +land that is let's see minus B is 1 plus + + + align:start position:0% +land that is let's see minus B is 1 plus +or minus square root of B squared which + + align:start position:0% +or minus square root of B squared which + + + align:start position:0% +or minus square root of B squared which +is 1 minus 4 times that times that which + + align:start position:0% +is 1 minus 4 times that times that which + + + align:start position:0% +is 1 minus 4 times that times that which +is plus 4 over 2 so that's the square + + align:start position:0% +is plus 4 over 2 so that's the square + + + align:start position:0% +is plus 4 over 2 so that's the square +root of 5 + + align:start position:0% + + + + align:start position:0% + +so the eigenvalues are lambda 1 is 1/2 + + align:start position:0% +so the eigenvalues are lambda 1 is 1/2 + + + align:start position:0% +so the eigenvalues are lambda 1 is 1/2 +of 1 plus square root of 5 and lambda 2 + + align:start position:0% +of 1 plus square root of 5 and lambda 2 + + + align:start position:0% +of 1 plus square root of 5 and lambda 2 +is 1/2 of 1 minus square root of and + + align:start position:0% +is 1/2 of 1 minus square root of and + + + align:start position:0% +is 1/2 of 1 minus square root of and +sure enough they those add up to 1 and + + align:start position:0% +sure enough they those add up to 1 and + + + align:start position:0% +sure enough they those add up to 1 and +they multiply to give minus 1 okay those + + align:start position:0% +they multiply to give minus 1 okay those + + + align:start position:0% +they multiply to give minus 1 okay those +are the two I can go how what are those + + align:start position:0% +are the two I can go how what are those + + + align:start position:0% +are the two I can go how what are those +numbers approximately square root of 5 + + align:start position:0% +numbers approximately square root of 5 + + + align:start position:0% +numbers approximately square root of 5 +well it's more than 2 what less than 3 + + align:start position:0% +well it's more than 2 what less than 3 + + + align:start position:0% +well it's more than 2 what less than 3 +it could be nice to know these numbers I + + align:start position:0% +it could be nice to know these numbers I + + + align:start position:0% +it could be nice to know these numbers I +think I think that that so that number + + align:start position:0% +think I think that that so that number + + + align:start position:0% +think I think that that so that number +comes out bigger than 1 right yeah + + align:start position:0% +comes out bigger than 1 right yeah + + + align:start position:0% +comes out bigger than 1 right yeah +that's right this number comes out + + align:start position:0% +that's right this number comes out + + + align:start position:0% +that's right this number comes out +bigger than 1 it's about 1.618 + + align:start position:0% + + + + align:start position:0% + +not exactly it suppose it's one point + + align:start position:0% +not exactly it suppose it's one point + + + align:start position:0% +not exactly it suppose it's one point +just like a face so then what's lambda 2 + + align:start position:0% +just like a face so then what's lambda 2 + + + align:start position:0% +just like a face so then what's lambda 2 +is lambda 2 positive or negative + + align:start position:0% +is lambda 2 positive or negative + + + align:start position:0% +is lambda 2 positive or negative +negative right obviously negative and I + + align:start position:0% +negative right obviously negative and I + + + align:start position:0% +negative right obviously negative and I +knew that so it's minus and they add up + + align:start position:0% +knew that so it's minus and they add up + + + align:start position:0% +knew that so it's minus and they add up +to 1 so minus point 6 1 8 I guess ok and + + align:start position:0% +to 1 so minus point 6 1 8 I guess ok and + + + align:start position:0% +to 1 so minus point 6 1 8 I guess ok and +some more those are the two eigenvalues + + align:start position:0% +some more those are the two eigenvalues + + + align:start position:0% +some more those are the two eigenvalues +one eigenvalue bigger than one one + + align:start position:0% +one eigenvalue bigger than one one + + + align:start position:0% +one eigenvalue bigger than one one +eigenvalue smaller than one + + align:start position:0% +eigenvalue smaller than one + + + align:start position:0% +eigenvalue smaller than one +that's a great situation to be in of + + align:start position:0% +that's a great situation to be in of + + + align:start position:0% +that's a great situation to be in of +course the eigenvalues are different so + + align:start position:0% +course the eigenvalues are different so + + + align:start position:0% +course the eigenvalues are different so +there's no doubt whatever is this matrix + + align:start position:0% +there's no doubt whatever is this matrix + + + align:start position:0% +there's no doubt whatever is this matrix +diagonalizable is this matrix + + align:start position:0% +diagonalizable is this matrix + + + align:start position:0% +diagonalizable is this matrix +diagonalizable that original matrix a + + align:start position:0% +diagonalizable that original matrix a + + + align:start position:0% +diagonalizable that original matrix a +short we've got two distinct eigenvalues + + align:start position:0% +short we've got two distinct eigenvalues + + + align:start position:0% +short we've got two distinct eigenvalues +and we can find the eigenvectors in a + + align:start position:0% +and we can find the eigenvectors in a + + + align:start position:0% +and we can find the eigenvectors in a +moment but they'll be independent will + + align:start position:0% +moment but they'll be independent will + + + align:start position:0% +moment but they'll be independent will +be diagonalizable and now you can + + align:start position:0% +be diagonalizable and now you can + + + align:start position:0% +be diagonalizable and now you can +already answer my very first question + + align:start position:0% +already answer my very first question + + + align:start position:0% +already answer my very first question +how faster those Fibonacci numbers + + align:start position:0% +how faster those Fibonacci numbers + + + align:start position:0% +how faster those Fibonacci numbers +increasing how close they're increasing + + align:start position:0% +increasing how close they're increasing + + + align:start position:0% +increasing how close they're increasing +right they're not doubling at every step + + align:start position:0% +right they're not doubling at every step + + + align:start position:0% +right they're not doubling at every step +let's look again these numbers 5 8 13 + + align:start position:0% +let's look again these numbers 5 8 13 + + + align:start position:0% +let's look again these numbers 5 8 13 +it's not obvious the next would be 21 34 + + align:start position:0% +it's not obvious the next would be 21 34 + + + align:start position:0% +it's not obvious the next would be 21 34 +so to get some idea of what F 100 is can + + align:start position:0% +so to get some idea of what F 100 is can + + + align:start position:0% +so to get some idea of what F 100 is can +you give me any the crucial number so it + + align:start position:0% +you give me any the crucial number so it + + + align:start position:0% +you give me any the crucial number so it +these it's approximately what's + + align:start position:0% +these it's approximately what's + + + align:start position:0% +these it's approximately what's +controlling the growth of these + + align:start position:0% +controlling the growth of these + + + align:start position:0% +controlling the growth of these +Fibonacci numbers it's the eigen value + + align:start position:0% +Fibonacci numbers it's the eigen value + + + align:start position:0% +Fibonacci numbers it's the eigen value +and which eigen value is controlling + + align:start position:0% +and which eigen value is controlling + + + align:start position:0% +and which eigen value is controlling +that growth the big ones so F 100 will + + align:start position:0% +that growth the big ones so F 100 will + + + align:start position:0% +that growth the big ones so F 100 will +it be approximately some constant C one + + align:start position:0% +it be approximately some constant C one + + + align:start position:0% +it be approximately some constant C one +I guess times this lambda 1 is 1 plus + + align:start position:0% +I guess times this lambda 1 is 1 plus + + + align:start position:0% +I guess times this lambda 1 is 1 plus +square root of 5 over 2 to the hundredth + + align:start position:0% +square root of 5 over 2 to the hundredth + + + align:start position:0% +square root of 5 over 2 to the hundredth +power and the 200 in other words the + + align:start position:0% +power and the 200 in other words the + + + align:start position:0% +power and the 200 in other words the +eigen value these that the Fibonacci + + align:start position:0% +eigen value these that the Fibonacci + + + align:start position:0% +eigen value these that the Fibonacci +numbers are growing by about that factor + + align:start position:0% +numbers are growing by about that factor + + + align:start position:0% +numbers are growing by about that factor +you see that we we've got precise + + align:start position:0% +you see that we we've got precise + + + align:start position:0% +you see that we we've got precise +information about the about the + + align:start position:0% +information about the about the + + + align:start position:0% +information about the about the +Fibonacci + + align:start position:0% +Fibonacci + + + align:start position:0% +Fibonacci +numbers out of the Idaho okay and again + + align:start position:0% +numbers out of the Idaho okay and again + + + align:start position:0% +numbers out of the Idaho okay and again +why is that true let me go over to this + + align:start position:0% +why is that true let me go over to this + + + align:start position:0% +why is that true let me go over to this +board so what I'm doing here yeah the + + align:start position:0% +board so what I'm doing here yeah the + + + align:start position:0% +board so what I'm doing here yeah the +original eigen the original initial + + align:start position:0% +original eigen the original initial + + + align:start position:0% +original eigen the original initial +value is some combination of + + align:start position:0% +value is some combination of + + + align:start position:0% +value is some combination of +eigenvectors and then when we start + + align:start position:0% +eigenvectors and then when we start + + + align:start position:0% +eigenvectors and then when we start +multiple when we start going out the + + align:start position:0% +multiple when we start going out the + + + align:start position:0% +multiple when we start going out the +theory of Fibonacci numbers when we + + align:start position:0% +theory of Fibonacci numbers when we + + + align:start position:0% +theory of Fibonacci numbers when we +start multiplying by a 100 times + + align:start position:0% +start multiplying by a 100 times + + + align:start position:0% +start multiplying by a 100 times +it's his lambda 1 to the hundredth this + + align:start position:0% +it's his lambda 1 to the hundredth this + + + align:start position:0% +it's his lambda 1 to the hundredth this +term is is the one that's taken over its + + align:start position:0% +term is is the one that's taken over its + + + align:start position:0% +term is is the one that's taken over its +I mean that's be like one point six to + + align:start position:0% +I mean that's be like one point six to + + + align:start position:0% +I mean that's be like one point six to +the hundredth power the second term is + + align:start position:0% +the hundredth power the second term is + + + align:start position:0% +the hundredth power the second term is +practically nothing right the point six + + align:start position:0% +practically nothing right the point six + + + align:start position:0% +practically nothing right the point six +or minus point 6 to the hundredth power + + align:start position:0% +or minus point 6 to the hundredth power + + + align:start position:0% +or minus point 6 to the hundredth power +is an extremely small extremely small + + align:start position:0% +is an extremely small extremely small + + + align:start position:0% +is an extremely small extremely small +number so this is is this there were + + align:start position:0% +number so this is is this there were + + + align:start position:0% +number so this is is this there were +only two terms because we're two by two + + align:start position:0% +only two terms because we're two by two + + + align:start position:0% +only two terms because we're two by two +this number is this piece of it + + align:start position:0% +this number is this piece of it + + + align:start position:0% +this number is this piece of it +is there but it's it's disappeared where + + align:start position:0% +is there but it's it's disappeared where + + + align:start position:0% +is there but it's it's disappeared where +this piece is there and it's growing and + + align:start position:0% +this piece is there and it's growing and + + + align:start position:0% +this piece is there and it's growing and +controlling everything so so really that + + align:start position:0% +controlling everything so so really that + + + align:start position:0% +controlling everything so so really that +we're doing like problems that are + + align:start position:0% +we're doing like problems that are + + + align:start position:0% +we're doing like problems that are +revolving we're doing dynamic instead of + + align:start position:0% +revolving we're doing dynamic instead of + + + align:start position:0% +revolving we're doing dynamic instead of +ax equal B that's a static problem we're + + align:start position:0% +ax equal B that's a static problem we're + + + align:start position:0% +ax equal B that's a static problem we're +now we're doing dynamics a squared a + + align:start position:0% +now we're doing dynamics a squared a + + + align:start position:0% +now we're doing dynamics a squared a +cubed things are evolving in time and + + align:start position:0% +cubed things are evolving in time and + + + align:start position:0% +cubed things are evolving in time and +the eigenvalues are the crucial numbers + + align:start position:0% +the eigenvalues are the crucial numbers + + + align:start position:0% +the eigenvalues are the crucial numbers +okay I guess to complete this I better + + align:start position:0% +okay I guess to complete this I better + + + align:start position:0% +okay I guess to complete this I better +write down + + align:start position:0% + + + + align:start position:0% + +so we should complete the whole process + + align:start position:0% +so we should complete the whole process + + + align:start position:0% +so we should complete the whole process +by finding the eigen vectors okay well I + + align:start position:0% +by finding the eigen vectors okay well I + + + align:start position:0% +by finding the eigen vectors okay well I +have two up in the corner then I have to + + align:start position:0% +have two up in the corner then I have to + + + align:start position:0% +have two up in the corner then I have to +look at a minus lambda I so a minus + + align:start position:0% +look at a minus lambda I so a minus + + + align:start position:0% +look at a minus lambda I so a minus +lambda I is this 1 minus lambda 1 1 and + + align:start position:0% +lambda I is this 1 minus lambda 1 1 and + + + align:start position:0% +lambda I is this 1 minus lambda 1 1 and +minus lambda and now can we spot and + + align:start position:0% +minus lambda and now can we spot and + + + align:start position:0% +minus lambda and now can we spot and +eigenvector out of that that's s for + + align:start position:0% +eigenvector out of that that's s for + + + align:start position:0% +eigenvector out of that that's s for +these two lambdas this matrix is + + align:start position:0% +these two lambdas this matrix is + + + align:start position:0% +these two lambdas this matrix is +singular + + align:start position:0% +singular + + + align:start position:0% +singular +I guess the eigenvector 2x2 ought to be + + align:start position:0% +I guess the eigenvector 2x2 ought to be + + + align:start position:0% +I guess the eigenvector 2x2 ought to be +or easy so if I know that this matrix is + + align:start position:0% +or easy so if I know that this matrix is + + + align:start position:0% +or easy so if I know that this matrix is +singular then seems to me the eigen + + align:start position:0% +singular then seems to me the eigen + + + align:start position:0% +singular then seems to me the eigen +vector has to be lambda and one because + + align:start position:0% +vector has to be lambda and one because + + + align:start position:0% +vector has to be lambda and one because +that multiplication will give me the 0 + + align:start position:0% +that multiplication will give me the 0 + + + align:start position:0% +that multiplication will give me the 0 +and this multiplication gives me better + + align:start position:0% +and this multiplication gives me better + + + align:start position:0% +and this multiplication gives me better +give me also 0 do you see why it does + + align:start position:0% +give me also 0 do you see why it does + + + align:start position:0% +give me also 0 do you see why it does +this is the minus lambda squared plus + + align:start position:0% +this is the minus lambda squared plus + + + align:start position:0% +this is the minus lambda squared plus +lambda plus 1 it's the thing that's 0 + + align:start position:0% +lambda plus 1 it's the thing that's 0 + + + align:start position:0% +lambda plus 1 it's the thing that's 0 +because these lambdas are special + + align:start position:0% +because these lambdas are special + + + align:start position:0% +because these lambdas are special +there's the eigenvector x 1 is lambda 1 + + align:start position:0% +there's the eigenvector x 1 is lambda 1 + + + align:start position:0% +there's the eigenvector x 1 is lambda 1 +1 and X 2 is lambda 2 1 I did that as a + + align:start position:0% +1 and X 2 is lambda 2 1 I did that as a + + + align:start position:0% +1 and X 2 is lambda 2 1 I did that as a +little trick that was available in the 2 + + align:start position:0% +little trick that was available in the 2 + + + align:start position:0% +little trick that was available in the 2 +by 2 case so now I finally have to oh I + + align:start position:0% +by 2 case so now I finally have to oh I + + + align:start position:0% +by 2 case so now I finally have to oh I +have to take the initial you know so to + + align:start position:0% +have to take the initial you know so to + + + align:start position:0% +have to take the initial you know so to +complete this example entirely I have to + + align:start position:0% +complete this example entirely I have to + + + align:start position:0% +complete this example entirely I have to +say ok what was you 0 u 0 was F 1 F 2 so + + align:start position:0% +say ok what was you 0 u 0 was F 1 F 2 so + + + align:start position:0% +say ok what was you 0 u 0 was F 1 F 2 so +u 0 a starting vector + + align:start position:0% +u 0 a starting vector + + + align:start position:0% +u 0 a starting vector +f1 f0 and those were 1 and 0 so I have + + align:start position:0% +f1 f0 and those were 1 and 0 so I have + + + align:start position:0% +f1 f0 and those were 1 and 0 so I have +to use that vector so I have to look for + + align:start position:0% +to use that vector so I have to look for + + + align:start position:0% +to use that vector so I have to look for +from multiple of the first eigenvector + + align:start position:0% +from multiple of the first eigenvector + + + align:start position:0% +from multiple of the first eigenvector +and the second to produce u0 the 1 0 + + align:start position:0% +and the second to produce u0 the 1 0 + + + align:start position:0% +and the second to produce u0 the 1 0 +which this is what we'll find c1 and c2 + + align:start position:0% +which this is what we'll find c1 and c2 + + + align:start position:0% +which this is what we'll find c1 and c2 +and then I'm done so let me in the last + + align:start position:0% +and then I'm done so let me in the last + + + align:start position:0% +and then I'm done so let me in the last +five seconds grinding out a formula let + + align:start position:0% +five seconds grinding out a formula let + + + align:start position:0% +five seconds grinding out a formula let +me repeat the idea that I really it's + + align:start position:0% +me repeat the idea that I really it's + + + align:start position:0% +me repeat the idea that I really it's +the idea that central when things are + + align:start position:0% +the idea that central when things are + + + align:start position:0% +the idea that central when things are +revolving in time let me come back to + + align:start position:0% +revolving in time let me come back to + + + align:start position:0% +revolving in time let me come back to +this board because the ideas are here + + align:start position:0% +this board because the ideas are here + + + align:start position:0% +this board because the ideas are here +when things are evolving in time by a + + align:start position:0% +when things are evolving in time by a + + + align:start position:0% +when things are evolving in time by a +first order system starting from an + + align:start position:0% +first order system starting from an + + + align:start position:0% +first order system starting from an +original unit the key is find the + + align:start position:0% +original unit the key is find the + + + align:start position:0% +original unit the key is find the +eigenvalues and eigenvectors of a that + + align:start position:0% +eigenvalues and eigenvectors of a that + + + align:start position:0% +eigenvalues and eigenvectors of a that +will tell those eigenvectors are the + + align:start position:0% +will tell those eigenvectors are the + + + align:start position:0% +will tell those eigenvectors are the +eigenvalues will already tell you what's + + align:start position:0% +eigenvalues will already tell you what's + + + align:start position:0% +eigenvalues will already tell you what's +happening is the solution blowing up is + + align:start position:0% +happening is the solution blowing up is + + + align:start position:0% +happening is the solution blowing up is +it going to 0 what's it doing and then + + align:start position:0% +it going to 0 what's it doing and then + + + align:start position:0% +it going to 0 what's it doing and then +to find out exactly a formula you have + + align:start position:0% +to find out exactly a formula you have + + + align:start position:0% +to find out exactly a formula you have +to take your u0 and write it as a con + + align:start position:0% +to take your u0 and write it as a con + + + align:start position:0% +to take your u0 and write it as a con +nation of eigenvectors and then follow + + align:start position:0% +nation of eigenvectors and then follow + + + align:start position:0% +nation of eigenvectors and then follow +each eigenvector separate and that's + + align:start position:0% +each eigenvector separate and that's + + + align:start position:0% +each eigenvector separate and that's +really what this formula the formula for + + align:start position:0% +really what this formula the formula for + + + align:start position:0% +really what this formula the formula for +that that's what the formula for a to + + align:start position:0% +that that's what the formula for a to + + + align:start position:0% +that that's what the formula for a to +the K is doing so remember that formula + + align:start position:0% +the K is doing so remember that formula + + + align:start position:0% +the K is doing so remember that formula +for a to the K is s lambda to the K s + + align:start position:0% +for a to the K is s lambda to the K s + + + align:start position:0% +for a to the K is s lambda to the K s +inverse okay that's that's difference + + align:start position:0% +inverse okay that's that's difference + + + align:start position:0% +inverse okay that's that's difference +equations and you just have to so that + + align:start position:0% +equations and you just have to so that + + + align:start position:0% +equations and you just have to so that +the homework will give some examples + + align:start position:0% +the homework will give some examples + + + align:start position:0% +the homework will give some examples +different from Fibonacci to next time + + align:start position:0% +different from Fibonacci to next time + + + align:start position:0% +different from Fibonacci to next time +will be differentially + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/2qxY859dzzQ.txt b/2qxY859dzzQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..f6ed3af65086f4502ca7ee2d78f9f01ce8a9b0af --- /dev/null +++ b/2qxY859dzzQ.txt @@ -0,0 +1,1364 @@ +PROFESSOR: Hi. + +Well, if you're ready, +this will be the + +other big side of calculus. + +We still have two functions, +as before. + +Let me call them the height and +the slope: y of x and the + +slope, s of x. + +Function one and function two. + +That's what calculus is about. + +And earlier, we figured out how +to go from function one if + +we knew that, how to +find the slope. + +Of course, it was easy when +function one was just a + +straight line. + +Then the slope was just +up divided by across. + +But when function +one was curving, + +we had to do something. + +We had to take just a small +distance across, a small + +distance up and divide, +and then let small + +get smaller and smaller. + +The result of that was function +two, the derivative. + +Today, we're going +the other way. + +We know the slope. + +We know s of x, and we want +to find the height, y + +of x, of the graph. + +We know how the graph is sloping +at every point, and we + +have to put all that information +together to find + +its height. + +OK. + +Let me say the easiest way to +do it, when it works, is to + +recognize if we are given a +formula for the slope, to + +recognize maybe we know a height +that goes with it. + +Let me take an example. + +So the one, and most important +case of a height + +is x to some power. + +x to n. + +That's one that everybody +learns. + +When y is x to the nth, the +result of this process that + +produces function two going in +that direction is dy/dx is + +that n comes down and we +have one lower power. + +So if we happen to have that +as our slope, that would be + +our height. + +Nothing more to do. + +But many other slopes +are possible. + +Let's just stay with this +another minute. + +What if the slope was +x to the nth itself? + +What if we started with function +two as x to the nth. + +Suppose dy/dx is x to the nth +power, like x squared. + +Where does x squared +come from? + +Well, look at this rule. + +That rule said that for these +power functions, the power + +drops by one. + +So if I want to end up with x +to the nth, going backwards, + +function one had better be, +involve an x to the n plus 1. + +But that's not perfect, of +course, because when I take + +the slope of that one, this +factor, this power, this + +exponent, n plus n +will come down. + +Just as n came down to here, n +plus 1 will come down, and + +therefore I'd better divide by +n plus 1 so that when I do + +take the slope, when I do go to +number two, the n plus 1's + +will cancel. + +The power will drop by one, and +I'll have x to the nth. + +OK, there's an example-- + +quite a useful one-- + +of going from step two to +step one just by kind of + +recognizing what +you want there. + +So this is one set that +everybody learns. + +Another is sines and cosines, +if you can fit it into that. + +Another is either +the x or logx. + +That's pretty much the list. +And then you learn, in the + +future, ways to change things +around to fit into one of + +those forms. But then, +of course, there + +are many, many cases-- + +many, many functions, too-- that +you don't fit, can't fit + +into a form where you can +recognize from some list which + +you either have learned or you +find on the web or you find in + +the calculator. + +A lot of lists have been made +to help you go from two to + +one, but today we have +to understand what + +is the actual process. + +What is the, what is the the +reverse process to this one? + +And of course, this one involved +a limit as delta x + +went to 0, because always I have +to remember that things + +can be curving, things can be +changing, I can't assume that + +they're saying the same. + +And then, the reverse +direction. + +Maybe I just tell you first +what the symbol is. + +If I have this s of x and I want +to get back to y of x-- + +so this is from two to one-- + +one will be y of x. + +The symbol for y +of x will be-- + +it's, I'm just really wanting to +draw that integral symbol. + +The integral, I would say the +integral of s of x dx. + +And you'll see why-- + +this is, that's an s-- + +you'll see why that's a +reasonable way to write it. + +But of course, first, we need +the idea behind it. + +OK, so how am I going +to proceed? + +Step one, I'll take steps, I +won't try to get immediately + +to the case of continuous +change. + +I'll take single, individual +steps. + +Let me do that. + +And then, I'm going to +take smaller steps. + +And then in the limit, I'm +taking continuous steps. + +OK, so first, big steps. + +So let me put down, for example, +suppose I have y's. + +Suppose the y's stepped up like +0, 1, 4, 9, 16, whatever. + +So those are heights, and, of a +graph that's sort of pieces + +of straight lines, only +changing a few times. + +What would be the slopes? + +Going now, this is +one going to two. + +The slope is s. + +Well, the slope, if the step +size is one and I go up by + +one, the slope will be 1. + +Here I go up by 3. + +Here I go up by 5. + +Here I go up by 7. + +So if I, to go from there to +there, I'm taking differences. + +I'm taking delta y's. + +These s's are delta y's. + +How do I go backwards? + +Suppose I gave you 1, 3, 5, 7, +and I started y off at 0. + +How could you recover +the rest of the y's? + +Well, that I would, that 1 plus +3 is the 4, 1 plus 3 plus + +5 is the 9, 1 plus +3 adds 7 more. + +You're up to 16 and onwards. + +So if going this way is a +subtraction at each step, + +going this way is a kind +of running addition. + +I add up all the slopes to +see how far I've climbed. + +Let me do a second example, +just to make that point. + +Let me start you this time, +let me start you with the + +slopes, because that's +today's job. + +Suppose the slopes are +4, 3, 2, 1, 0. + +So if these were speeds, +I would say, + +OK, I'm slowing down. + +I'm slowing down, but I'm +still moving forward. + +Positive speeds, but putting +the brakes on. + +What would be the distances? + +If the trip meter starts, start +the trip meter at 0. + +OK. + +Then in the first second or +hour, the first delta x we + +would go 4. + +And what goes there? + +7, right? + +I'm doing, I'm accumulating, +adding up the distances. + +Here I was at 4. + +I went another three +to 7, to 9, 10. + +Here's, I didn't move. + +No speed, zero slope, stays +flat, hit the top at 10. + +OK, I could do this with any +bunch of numbers and I can do + +it with letters. + +So now I move from arithmetic +to algebra. + +Algebra just means I'll do it +with any letters, but I'm not + +yet doing it continuously, +which is what + +calculus will do. + +So with letters, I have here y0, +y1, y2, y3, y4, let's say. + +So those are the y's. + +Now what are the slopes between +them if the step + +across is 1? + +So what are the steps upward, +what are the delta y's? + +Well, y1 minus y0, y2 minus y1, +y3 minus y2, y4 minus y3. + +And then my question is these +are the s's, these are the + +delta y's, you could say. + +These are the y's. + +What happens if I add +all those delta y's? + +Do you see what happens? + +What happens if I add those +four changes to + +get the total change? + +Well, when I add those, do you +see that y1 will cancel minus + +y1, y2 will cancel minus y2, +y3 will cancel minus y3. + +So the sum-- + +and I use just a sigma symbol, +but I'll just say sum and you + +know what I mean-- + +of these delta y's is what? + +What happened after all +those cancellations? + +Did everything cancel? + +No way. + +y4 is still there, minus +y0 is still there. + +So it was y4 minus y0. + +The last y minus the first y. + +I'll just write y last minus +y 0, y first. y end minus y + +start is the sum of +the delta y's. + +Simple algebra. + +Reminding us again and again and +again that the opposite, + +the inverse to go the other way +from two to one, we add + +pieces to get back to the y's. + +Now I'm coming closer to what I +want, but I'm moving toward + +calculus now. + +So calculus, I got there by +delta y's over delta x's. + +So in moving toward calculus, +what am I doing? + +I'm thinking of the changes +delta y over + +smaller steps delta x. + +So I just want to +take this step. + +I want to divide by delta x +and multiply by delta x. + +Why do I do that? + +That's because it's this delta +y over delta x that is-- + +it's those ratios, whatever +the size of delta x is. + +And it's going to get +smaller and smaller. + +I'm going to look at the change +over very short steps. + +Then it's that ratio +that make sense. + +Delta y over delta x is +a reasonable number. + +It's close to the s. + +It's close to dy dx, but it +hasn't got there yet. + +I'm multiplying by the delta x, +the small step that's going + +to 0 but hasn't got there yet. + +And I'm adding and I get the +last one minus the first one. + +Now here comes the +limiting step. + +So the limiting step will be +the limit of this left hand + +side, this sum. + +So in the limit, I'll have more +and more and more things. + +As delta x gets smaller, if +I'm thinking of some fixed + +total change in x, I'm chopping +that up into smaller + +and smaller pieces, more +and more pieces. + +So more and more pieces of the +slopes at different points + +along times the size of the +piece give this answer. + +So now can I jump to the +way that I would + +write this in the limit? + +So now let delta x go to 0. + +And I ask the right hand +side, y last minus y + +first is not changing. + +y at the end-- + +I'll write something different, +y end minus y + +start, just to make that +same point again. + +But it's this that's changing. + +As delta x goes to 0, +this becomes dy dx. + +The little delta x's +are going to 0. + +Here's the way I write it. + +So in that limit, I can't +legally write that sigma, so + +this integral symbol is kind +of copied from that sigma. + +But it's telling you that +a limit has happened. + +And in that limit, this +is dy dx and this, the + +notation, is dx. + +I've got what I predicted +here, with s of x there. + +So what I hope this discussion +has, by starting with numbers, + +by going to algebra, by looking +at the sum of those + +things, which was simple, and +then by going to the limit, + +which was not simple. + +So a whole lot of limit has been +not fully explained, and + +I think the right thing to do +now is to do an example. + +So let me move to an example. + +So I'll take a particular +function and follow this + +process, this limiting process +and see what it gives. + +And it will give us function one +and, as a bonus, it will + +give us a new meaning +for function one. + +Let's do it. + +So now I'm going to take +a particular s of x. + +So here's x. + +Let me take s of x +to be 2 minus 2x. + +I didn't want to take one +totally simple that I already + +had started the lecture with, +but it's not difficult either. + +We'll be able to see what's +happening here. + +OK, so let me graph it, because +I want to do this now + +with the graph. + +So at x equal 1, s of x has +dropped to 0, where when x was + +0, it started at 2. + +So it started somewhere here. + +Here was 1, halfway down. + +It's going to come down +in a straight line. + +And let me stop there. + +It could continue, but let me +call y end is going to be 0 + +and y start is going to be-- + +well, we'll see about +that, sorry. + +s at the end is 0. + +S at the end is 0. + +I don't yet know what +y at the end is. + +It's not 0. + +So what's my idea? + +Well, not mine. + +Newton and Leibniz and a lot +of people had these ideas. + +It's kind of interesting. + +So Archimedes. + +He goes way, way back, before +Newton or Leibniz or anybody + +conceived of them. + +Archimedes figured out +how to deal with a + +curve with a parabola. + +Archimedes got from a parabola, +he got from x + +squared, the parabola, back to +a height by special ideas. + +He was one of the great +mathematicians of all time. + +But even Archimedes didn't see +what you now see, this + +connection between function +one and function two. + +If he had seen that, he would +have gone further. + +All right, now let's see it. + +Let me take a delta +x equal to 1/4. + +So this is delta x here, and +this one is two delta x's, and + +this one is three delta x's, and +the one is four delta x's + +in my original delta x, which is +1/4, which is small but not + +really small. + +So now what do I do? + +Look at this first period. + +The slope, the s function, +function two-- + +see, over here is going +to be function one. + +This is going to be the y, +the integral of that. + +But I don't know what +it is yet, so it's + +pretty open to question. + +OK, so now let's get there. + +So the point is that +over this interval, + +the slope is changing. + +It's changing a significant +amount. + +Not too much, but +it's changing. + +And I don't know, from the +algebra, I don't know how to + +deal with that. + +I'm just going to take a value +within this sum value and stay + +with it within that interval, +and I'll take + +the starting value. + +So over this first delta x, I'm +going to pretend that the + +slope stays at 2. + +So I'm pretending that this +is my slope function. + +Then over my next delta x, I'm +going to pretend that it stays + +at probably 1 1/2. + +And then I'm going to pretend +that it stays at 1, and I'm + +going to pretend that +it stays at 1/2. + +If you allow me to go back to +distance and speed, I'm + +chopping up the full time, the +day, let's say, into four + +pieces and in each piece, the +speed is changing, which I'm + +not ready to deal with, +which algebra isn't + +ready to deal with. + +So the best I could do was say +OK, so suppose the speed is + +constant at what it was at the +start of that short time. + +So those would be delta t's +rather than delta x's. + +The s would be representing +speed, but no difference in + +the picture. + +So now let me do these things. + +Now I'm going to do this +addition, which won't give me + +exactly the right y because +those rectangles are not + +exactly right. + +But I'll get them better by +taking smaller delta x's. + +Let me see, what +do I have here? + +Over this first time, I +have my slope, which + +I'm taking to b 2. + +So that's the delta y over delta +x, that's the s, and + +then times the delta x. + +And what is that? + +We might as well just face it, +that that 2 times that delta + +x, we can think of that +as the area in + +that tall, thin rectangle. + +Well, I've introduced the word +area for the first time. + +It never showed up on +the previous board. + +It's the extra insight +that's coming today. + +Now over the second short +period, I'm going to keep fix + +my speed at 1 1/2. + +1 1/2 times delta x, because my +speed I'm setting at 1 1/2, + +and this is how long I go so +this is a distance or a change + +in height, a change in y. + +And you see what's coming. + +The next one will be a 1 times +the delta x, and the last will + +be 1/2 times the delta x. + +This is adding the way +I did in the algebra. + +And what do I get? + +Well, this, again, is the +area of that piece. + +This one is the area of that +piece, this one is the area of + +that piece. + +I get an overestimate because +the true slopes dropped a + +little within each piece. + +I get some quantity which I can +figure out, but it's not + +the right answer. + +It's not the final answer. + +And what is now the main +step to get there? + +Chop delta x into half, +you could say. + +Why not cut it in half? + +Now I'll have a different +picture. + +Can you see what this +picture is doing? + +Now over the first little half +of the old step I am up here, + +but then I drop to here. + +Can I do this with an eraser? + +A little bit got chopped away, a +little bit got chopped away. + +Where has it gone? + +I'm going to have +this zig zag. + +That wasn't too bad. + +I'm replacing that with a sum of +eight pieces, because delta + +x is now down to 1/8. + +This is what we said +about that sum. + +That sum has got more and more +terms because it has a term + +for every little delta x, and +the size of that term is about + +like delta x multiplied +by an s. + +So what I getting in the limit +is a kind of running sum, a + +running counter, a mileage +meter, a trip mileage, that's + +adding up distance +based on speed. + +Do you see what I'm getting +in the graph picture? + +What happens to the shaded part +as delta x gets smaller + +and smaller? + +This shaded part is going +to be the curve. + +These little long pieces are +going to get reduced, reduced, + +reduced, and in the end +the total height at + +1 is going to be-- + +ta-da, this is the moment-- + +the area under the +slope curve. + +This y turns out to be +the area under the s + +of x curve, or y. + +So at x equal 1, what is it? + +What's the area out to 1? + +Well, we've got a +triangle there. + +Its base is 1, its +height is 2. + +The area of a triangle is 1/2 +the base times the height, so + +I have 1/2 times 1 times 2. + +I've got 1. + +The area at the end is 1. + +But-- + +well, I shouldn't say but. + +I should let you applaud first. +What if I only went + +that far, halfway? + +What if that was s end? + +What if I want to know what +is y at x equal 1/2? + +Then it'll be of course, just +the area up to that point. + +Can I remove this part of the +picture for a moment? + +I'm always looking at area. + +And the area of that, do we know +what that area would be? + +It's not a triangle anymore, +it's some kind of a trapezoid. + +As delta x goes to 0, I'm going +to get the correct area, + +which will be what? + +Let's see, I have 1/2 as the +base and the average height is + +about 1 1/2. + +Can I do that little +calculation? + +The base is 1/2 and the average +height is 1 1/2. + +I think I get 3/4. + +So halfway along, it's +got up to 3/4. + +Where is 3/4? + +So this is 1, this is 3/4, +this is 1/2, this is 1/4. + +So at 1, it's at 3/4. + +Halfway along, its at 3/4. + +I would like to know +that graph now. + +I'm ready to jump +to the limit. + +Let me do it the way I said at +the very start of the lecture. + +Let me take this and +try to guess. + +So, I'm taking a shortcut. + +Because do we go through this +horrible process every time we + +want to do an integral? + +Of course we don't. + +The best way is, can we find a +y function, a function, one, + +that has that derivative? + +Let's just try it. + +I'm allowed to take it in +two pieces, that's a + +very valuable fact. + +So what has the derivative 2? + +If the slope is 2, what's +the function? + +If the speed is 2, what's +the distance? + +It's constant speed, 2, times +the total distance. + +The slope of the 2x line +is 2, clearly. + +What about the 2x? + +Which function has +the slope 2x? + +Well, we saw it over here. + +The function that has the slope +2x is x squared, because + +when I take the slope of x +squared, the 2 comes down. + +The 2 shows up, I have +one smaller power, x + +to the first power. + +This is the correct y, and I +hope that my graph gets those + +points right. + +At x equal to 1, this is +2 minus 1, this is the + +correct height, 1. + +At x equal to 1/2, all right, +here is the moment of truth. + +Now set x equal to 1/2, and what +do you get for this y? + +You get 2 times 1/2-- +that's 1-- + +minus 1/2 squared, 1/4. + +Hey, miracle. + +3/4. + +This area I figured +to be 3/4 and this + +approach also gave 3/4. + +Either way, multiplying +those is 3/4, + +subtracting those is 3/4. + +What does my graph look like? + +What does the graph +of that look like? + +What's the slope at the start? + +The slope at the start +is s at the start. + +And s at the start, when +x is 0, the slope is 2. + +So it starts out with +a slope of 2. + +But it's slowing down, it's a +little bit like this one where + +the car was slowing down, we're +not picking up distance + +so quickly, we're not picking +up height so quickly. + +But we're still going +forward, we're still + +picking up some height. + +So it starts with a slope of 2, +bends around to there, and + +I guess maybe that is-- + +yes. + +That picture is almost +good, but not great. + +So the slope is 2 and there. + +And what is the slope +at this point? + +You can't tell from my picture, +which isn't perfect. + +The slope, I'm told +what it is. + +When x is 1, the slope +is 2 minus 2. + +Slope 0. + +The slope is 0. + +We're not picking up any more +height, any more area. + +And of course, that's right. + +At this point, we're not +picking up more area. + +If I continue beyond here, +we're losing area because + +below the axis, I'll count as +negative area just because if + +it was speed, I'd be +going backwards. + +That's what will happen here. + +I'll start down. + +If that continued, this +would still be the + +correct thing to graph. + +If I do graph it, that's +actually the top at x equal 1, + +and then it starts down and +probably by, I don't know + +where, x equal something, +maybe by x equal 2. + +Oh yeah, you can see. + +By x equal to 2, it's +got down to 0 again. + +When x is 2, this is now 0 and +you can see that when x is 2, + +we'll have the bad area-- + +the car going backwards-- + +will be identical to +the forward area. + +The total area is 0, and I'll be +at this point when x is 2. + +Let me just recap a moment. + +Today was about going +from function two + +back to function one. + +The quickest way to do it is +to find a function one that + +gives that function two +and then you're in. + +But if you can't do that or if +you want to understand what + +the real, behind it, limiting +process is, it's like the + +algebra but it's this expression +here that's + +concealing so much +mathematics. + +Delta x going to 0, these ratios +going to the actual + +function, and the delta x I +replaced by the symbol dx, + +indicating an infinitesimal. + +We'll see it more. + +Thank you. + +NARRATOR: This has been +a production of MIT + +OpenCourseWare and +Gilbert Strang. + +Funding for this video was +provided by the Lord + +Foundation. + +To help OCW continue to provide +free and open access + +to MIT courses, please +make a donation at + +ocw.mit.edu/donate. \ No newline at end of file diff --git a/4-ehnTIyV0A.txt b/4-ehnTIyV0A.txt new file mode 100644 index 0000000000000000000000000000000000000000..a20c0636ff97d860efaf1ae3ac90c8b557c86b28 --- /dev/null +++ b/4-ehnTIyV0A.txt @@ -0,0 +1,2369 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Ladies and gentlemen, +welcome to this + +lecture on nonlinear finite +element analysis of solids and + +structures. + +In the previous lectures, we +talked about the basic process + +of the incremental solution +that is used in + +finite element analysis. + +And we talked about quite some +important continuum mechanics + +variables that we are employing +in nonlinear finite + +element analysis. + +This was really preparatory work +for the discussion of a + +general formulation that is very +widely used to analyze + +nonlinear systems using +finite elements. + +And this formulation is called +the total Lagrangian + +formulation. + +This is the formulation that I'd +like to discuss with you + +now in this lecture. + +The total Lagrangian formulation +is a formulation + +that refers the stress and the +strain variables at time t + +plus delta t to the original +configuration at time zero. + +Total, in fact, means reference +to the original + +configuration here. + +And notice we, of course, +encountered this equation + +already earlier in the +early lectures. + +We have on the left hand side +again the total internal + +virtual work. + +And on the right hand side, +the total external virtual + +work all at time +t plus delta t. + +We have here the second +Piola-Kirchhoff stress tensor. + +Here we have the Green-Lagrange +strain tensor. + +And on the right hand side, of +course, all the body forces, + +surface forces et cetera +would enter. + +We discussed in a previous +lecture how the right hand + +side is calculated in general +and what it all contains. + +We also discussed that this +equation here is quite + +equivalent to this equation. + +And in this equation, we have +the Cauchy stress tensor + +operating on the virtual +strain tensor, an + +infinitesimally small +strain tensor. + +And this product is integrated +over the volume at time + +t plus delta t. + +On the right hand side, +we have the same + +quantity as up there. + +Now notice that we really want +to solve, of course, this + +equation here in finite +element analysis. + +But we discussed earlier that in +order to do so effectively, + +we need to introduce a new +stress measure, a new strain + +measure, and that, of course, +brings us then to this + +equation up here. + +Let us recall briefly some of +the important points that we + +made earlier in the +other lectures. + +We said that this equation here, +applied at time t plus + +delta t, is an expression +of the equilibrium, + +compatibility, and the +stress-strain law at time t + +plus delta t. + +Let's just look at this equation +once more, where + +these quantities enter. + +Well, if equilibrium is +satisfied locally everywhere + +in the continuum, then this +equation must be holding for + +any virtual displacements that +satisfy the displacement + +boundary conditions, and +corresponding virtual strains. + +Notice that the virtual +displacements enter on the + +right hand side, and these here +are the corresponding + +virtual strains. + +The compatibility enters in +here because we would, of + +course, use compatible virtual +displacement, and we would + +calculate also the stresses from +compatible displacements. + +The stress-strain law enters +in the calculation of the + +stress here from the +strains given. + +And once again we apply this +at time t plus delta t. + +We also noted earlier that +we will be using + +an incremental solution. + +Namely, that the solution at +time t plus delta t will be + +calculated from the solution at +time t by incrementing the + +displacements by ui. + +Notice that we will assume, +of course, that + +the tui's are known. + +That the displacementts at time +t are known, and that + +these are the unknown +quantities that + +we're looking for. + +Of course, that gives us then +the unknown quantities that we + +actually want to solve for. + +Our goal is, for the finite +element solution to linearize + +the equation of the principle +of virtual work, so as to + +obtain a set of equations, +finite element equations, that + +read as follows. + +Here we have a stiffness +matrix, a + +tangent stiffness matrix. + +Here we have an incremental +displacement vector. + +And on the right hand side, we +have a load vector, a vector + +of nodal point forces +corresponding to the + +externally applied loads +at time t plus delta t. + +And here we have a nodal point +force vector that is + +equivalent to the current +element stresses, in this + +particular instance at time +t, as indicated by the + +superscript t here. + +Now this incremental +displacement vector, of + +course, will be added to the +displacement that we know + +already, and that correspond +to time t. + +And that will give us then +a first estimate for the + +solution, displacement +solution, at time + +t plus delta t. + +Notice this is also summarized +down here. + +Notice, however, that this +vector here is only an + +approximation to the actual +vector that we're looking for, + +because of the linearization +process that leads us to this + +system of equations. + +The equation tku equals r +minus f is, of course, + +applicable for a single element +as well as a total + +assemblage of elements. + +In other words, this equation +here, tk delta u1 equals t + +plus delta r minus tf, would be +applicable to an element in + +which n then would mean just +the degrees of freedom, the + +number of degrees of freedom +of that element. + +And also for a total structure +in which n then, of course + +means the total number of +structural degrees of freedom. + +The tk matrix, the r vector, +and the f vector would be + +constructed using the direct +stiffness method the way we + +are used to it in the linear +elastic analysis. + +In other words, there is +nothing new here to be + +discussed really, as far as a +construction of these matrices + +go, when we talk about a total +element assemblage from the + +individual element matrices. + +However, an important point +is that we cannot simply + +linearize the principle of +virtual work when it is + +written in this form here. + +And the reason was, of course, +that we cannot integrate over + +an unknown volume. + +The volume t plus delta t is +unknown, or the volume at time + +t plus delta t is unknown, and +we cannot directly increment + +the Cauchy stresses the way we +discussed it already earlier. + +To linearize then, we need to +choose a known reference + +configuration. + +And one known reference +configuration that is a very + +natural one to use really, +is the one + +corresponding to time zero. + +In this case, if we use that +reference configuration, we + +talk about the total Lagrangian +formulation. + +If we use as a reference +configuration the + +configuration corresponding to +time t, then we talk about the + +updated Lagrangian +formulation. + +I'd like to make +one point here. + +Namely, that of course we have +calculated already from all + +the configurations from +time zero to time t. + +So you may ask yourself, why +is he not choosing as a + +reference configuration, for +example, the configuration t + +minus delta t? + +In other words, one +configuration prior to time t + +as a possibility. + +Well, it would be a possibility, +but if you choose + +to do so, you would lose the +advantages that you have in + +the updated Lagrangian +formulation, and the + +advantages that you would have +in the total Lagrangian + +formulation. + +Of course, there are differences +here and we will + +talk about the advantages and +disadvantages of either of + +these formulations. + +And you would be left with that +choice of t minus delta t + +reference configuration, +with basically all the + +disadvantages only. + +And therefore, we generally want +to choose either this one + +or that one as the reference +configuration. + +Let us now discusses the total +Lagrangian formulation. + +In the total Lagrangian +formulation, we use the + +reference configuration zero, +and therefore we talk about + +this stress. + +We use this stress and that +strain, this was a second + +Piola-Kirchhoff stress referred +to the configuration + +at time zero. + +This is the Green-Lagrange +strain referred to the + +configuration at time zero. + +The principle of virtual work +once again, originally in this + +form, is now written +in this form. + +We have had that already before +on viewgraphs, and I + +don't think I need to go through +those details again. + +But the important point is +that this is the starting + +point of the total Lagrangian +formulation. + +The formulation proceeds +as follows. + +We know the solution at time t, +therefore this stress, this + +displacement derivative, all +the static and kinematic + +variables in fact, are known +corresponding to the + +configuration at time t. + +And we can now decompose the +stress corresponding to time t + +plus delta t into one known +value and one unknown value. + +Similarly we proceed with +the strain measures. + +The strain measures, the +Green-Lagrange strain at time + +t plus delta t is decomposed +into one value that we know + +already, and an increment. + +And, of course, remember these +two increments are unknown. + +They are unknown, whereas these +are known because we + +have calculated already +the configuration + +corresponding to time t. + +In terms of displacements, we +can directly develop that the + +Green-Lagrange strain at time +t is written as shown here. + +We went over these different +components already earlier. + +Notice once again that we have +a product of displacement + +derivatives here, +that this is, of + +course, a nonlinear term. + +And once again, as I pointed out +in an earlier lecture, we + +have nothing neglected here. + +You see only quadratic terms. + +There are no cubic terms +or higher-order terms. + +We have nothing neglected. + +This is a strain measure that +holds for any amount of + +deformation, any amount +of strain. + +Then we can also write this same +strain, Green-Lagrange + +strain, corresponding to time t +plus delta t, and this would + +be the result. + +Notice whatever we had here as t +superscript has now become a + +t plus delta t superscript. + +That's in fact the +only difference. + +If you subtract from this +strain, that strain, we get + +the increment, and +that increment is + +written out right here. + +Now, there are some interesting +points regarding + +this incremental strain. + +This here is an increment in the +strain that is linear in + +the displacement components. + +Similarly this one. + +Notice this one here, is, of +course a product, product and + +may look, at first sight, +as a nonlinear term. + +When you see products of +displacements, you think of a + +nonlinearity. + +However, if you look closer, +you find that + +there is a t here. + +Therefore, this part is known. + +Since this part is known, and +this part is unknown, this + +total term is really linear in +the incremental displacement. + +In fact, the incremental +displacements don't even go in + +here, because we're +differentiating here the + +displacements at time t with +respect to the original + +coordinates. + +Therefore, this total +term here is really + +still linear in ui. + +Linear in the incremental +displacements. + +We call this part here, as +given here, the initial + +displacement effect. + +The initial displacement effect +because the initial + +displacements go into these +derivatives here. + +We are differentiating the +displacement at time t with + +respect to the original +coordinates. + +This term, on the other hand +here, is nonlinear in ui. + +It is nonlinear because here +we're taking one term that + +depends on ui, and we multiply +it by another term that + +depends on ui. + +Notice this a differentiation +of uk, the incremental + +displacement, into the k +direction with respect to the + +original coordinates. + +Coordinate axis xj +here particular. + +So this is here, clearly +a nonlinear term in ui. + +A quadratic term, as +a matter of fact. + +We will look at this strain, +of course, a little + +bit more just now. + +But keep in mind that there is +one linear term that contains + +an initial displacement effect +and a nonlinear term. + +I might add here that, of +course, this initial + +displacement effect is +zero if the initial + +displacements are zero. + +In other words, in our +incremental solution, for + +example, if we are just starting +the solution process, + +then the initial displacements +are still zero. + +This term drops out. + +We note now regarding the +formulation that the variation + +on the total Green-Lagrange +strain tensor corresponding to + +time t plus delta t, is really +equal to the variation in the + +increment of the Green-Lagrange +strain tensor, + +from time t to time +t plus delta t. + +In this picture we show +what we mean by that. + +Here on the left hand side in +black, you have the body in + +its original configuration. + +It moves to a configuration +at time t. + +And then to a configuration, +here shown in green, that + +corresponds to time +t plus delta t. + +Notice here we have the +displacement corresponding to + +time t, and then the +displacement corresponding + +from time t to time +t plus delta t. + +The total displacement, +of course, here is the + +displacement from time zero +to time t plus delta t. + +What we are doing, of course +in the principle of virtual + +work, is to impose a variation +in displacements about the + +configuration at time +t plus delta t. + +And that variation is here +indicated by the blue line. + +And if we impose this variation +here, since the + +displacements at time t are +constant, surely whatever + +these displacements were +should not matter. + +And that is, in fact, +expressed by this + +relationship here. + +If we vary here, since the +displacements to ui are + +constant, they do not affect the +variation on the strains. + +And therefore, we can simply +vary the incremental strain, + +and we find that variation is +indeed equal to the variation + +of the total strain. + +Of course, you can also +prove that to yourself + +mathematically by just going +through the arithmetic. + +In other words, applying the +variation to this quantity, + +and then applying the variation +to that quantity, + +which I've given you on the +previous viewgraph, and you + +would find that indeed you +get identically the same + +expressions. + +We can define a linear strain +term, linear strain increment, + +as 0 eij, and the nonlinear +strain increment as 0 eta ij. + +Notice that once again, here we +have the quadratic terms. + +And, of course, when we add +these two terms together, we + +get back our total strain +increment from time t to time + +t plus delta t. + +If we take a variation on that +increment, that is equivalent + +to taking a variation on +the linear term and + +the nonlinear term. + +Notice that so far we +have only talked + +about continuum mechanics. + +Of course we want to use the +continuum mechanics principles + +that we discussed so far +in the finite element + +discretization. + +But notice that these strain +terms here that we talked + +about, are really continuum +mechanics variables. + +There is an interesting +observation. + +Namely, if we talk about this +strain measure and that strain + +measure, rather the linear +incremental strains and the + +nonlinear incremental strains, +linear and nonlinear in ui, + +then if we apply these in finite +element analysis, we + +have to remember that the +displacements are interpolated + +in terms of nodal +point variables. + +And what we're really looking +for in finite element analysis + +are the nodal points +variables. + +In isoparametric finite element +analysis, which is the + +final element procedure that we +will be using extensively, + +we interpolate the internal +element displacements, tui, in + +terms of the nodal point +displacements. + +Let me define a little bit +more what this is here. + +This is, of course, the +displacement from time zero to + +time t into the i's direction. + +We are summing here over all +the finite element nodal + +points, the N nodal points. + +We have interpolation functions, +hk, that we will + +talk more about later on. + +And we have here the nodal point +displacement at time t + +into the i direction of +the nodal point k. + +This k goes with that k. + +And we're summing over +all the nodal points. + +Now notice that this is the +linear relationship in + +isoparametric finite +element analysis of + +solids, I should say. + +This is a linear relationship. + +And therefore, our linear strain +terms that we talked + +earlier about, being linear in +the incremental continuum + +mechanics displacements, are +also linear in the incremental + +nodal point displacements. + +Similarly, this term here, which +was nonlinear in the + +increments of displacements +within the domain, from a + +continuum mechanics point of +view, will also be nonlinear + +in the nodal point displacement +increments. + +However, in the formulation of +structural elements, with the + +incremental displacements, +in fact also the total + +displacements, I interpolated +using nodal point + +displacements and nodal +point rotations. + +In other words, we also deal +with nodal point rotations in + +order to calculate the total +displacements of the element. + +And in that case, we have to +recognize that the exact + +linear strain increment, the way +we have defined it earlier + +linear in the incremental +displacements, is still + +properly given as a linear +strain increment in the nodal + +point variables. + +However, the term that we +defined earlier as a nonlinear + +strain increment, this one, is +not the full story of all the + +nonlinear strain increments. + +Because the rotations will put +additional nonlinear strain + +increments into this +term here. + +The reason being, that for large +rotations, of course, we + +have cosine sine terms in these +rotations and when we + +evaluate the total nonlinear +strain term, we find that + +there are additional terms +coming up here. + +Well, what is the effect of +these two statements? + +It means that the right hand +side force vector, or rather + +the vector t 0 f, the vector +of nodal point forces + +corresponding to the internal +elements stresses, is always + +correctly calculated. + +However, the stiffness matrix, +t 0 k, for the formulation is + +only approximated because some +of the nonlinear terms here + +have been dropped in the case +of structural elements. + +Of course, you can also include +the nonlinear terms. + +Then you would have to add these +terms to this expression + +here, and then you would get a +true tangent stiffness matrix. + +This means, of course, for an +actual analysis, that when you + +form the equations, we have on +the left hand side-- let me + +just put all of it in here-- + +for the first iteration, we +talked about the fact that we + +have a stiffness matrix times an +increment in displacements. + +I already put a 1 there because +it will be only an + +approximation to the +total incremental + +displacement vector. + +Well, we notice then that this +matrix here is approximated if + +you were to drop these +additional terms. + +But the right hand side vector f +here is properly calculated. + +Therefore if you iterate, you +always get the exact solution, + +the correct solution. + +But the convergence in the +iteration might be a bit + +slower than what you could +have obtained if you had + +included these additional terms +here that I referred to. + +Let us now continue with +the continuum mechanics + +formulation. + +The equation of the principle of +virtual work becomes, if we + +substitute the quantities that +I defined earlier, directly + +this equation. + +Notice here we have now the +increment in stress times the + +variation of the incremental +Green-Lagrange strain, from + +time t to t plus delta t. + +Of course, it's integrated over +the original volume plus + +this integral here. + +Here we have the total stress, +second Piola-Kirchhoff stress, + +corresponding to time t +operating on the nonlinear + +strain increment of the total + +Green-Lagrange strain increment. + +And once again, we are +integrating over the total + +volume corresponding +to time zero. + +And on the right hand side, we +have the external virtual work + +minus the stress at time t, +operating on the linear strain + +increment corresponding +to the total + +Green-Lagrange strain increment. + +We have so far made no +approximations, and this is a + +relationship that has to hold +for any arbitrary variation in + +displacements which go in here, +or any arbitrary virtual + +displacement that go in here. + +And of course, corresponding +strains that appear here. + +In essence, what we have been +doing is that we have + +established a variation on +the configuration at time + +t plus delta t. + +We have looked at the principle +of virtual work + +corresponding to time t plus +delta t, but we have + +introduced this increment +in displacement. + +Notice that this increment in +displacement is measured from + +the displacement at time t. + +All we have done therefore, is +to rewrite the principle of + +virtual work in terms of tu and +u instead of dealing with + +t plus delta tu. + +No approximation being +done yet so far. + +Of course, we really haven't +been talking about finite + +elements either yet, when we +just look at this basic + +equation of principle +of virtual work. + +It is this principle or the +equation that we are dealing + +with, is in general, a very +complicated function of the + +unknown displacement +increment. + +We obtain an approximate +relationship in finite element + +analysis, by linearizing the +governing equation, and, of + +course, then in the finite +element sense cast it into + +this set of linear equations. + +The process of linearizing is +a very important process, + +interesting process for us +to study, and that's what + +I want to do now. + +We begin to look, in this +linearization at all the + +individual terms that appear +in the integral. + +And let us look first +at this term here. + +This term is actually already +linear in ui. + +So there is nothing +much to linearize. + +t 0 sij does not contain ui. + +It's a known quantity. + +It's a known stress value. + +And notice that when we take +the variation on this + +nonlinear strain increment, we +directly get this expression, + +where this part here is +a variation on the + +displacement increment. + +Similarly here. + +And of course, these are +going to be constants. + +Therefore, this term here is +linear in the incremental + +displacements. + +Linear in ui. + +So nothing to linearize there. + +The term on this viewgraph here, +contains an incremental + +stress and an incremental +strain. + +Notice this incremental strain +contains the linear and the + +nonlinear term. + +And this, of course, this +product is a linear functional + +off ui, sorry it contains +linear terms, + +nonlinear terms as well. + +This stress here is, in general, +a nonlinear function + +of 0 epsilon ij. + +The variation that we are +taking here means we are + +taking a variation on +the linear part and + +the nonlinear part. + +We will see actually that this +one here is constant. + +But this one carries also terms +of ui, so this total + +expression is linear in ui. + +And if we multiply these terms +here, we want to end up in + +just one expression that has +neglected all higher-order + +terms in ui, but just +contains ui. + +Well, let us do so. + +The objective is expressed +once more here, and we + +recognize that, of course, the +variation on 0 epsilon ij + +contains only constant and +linear terms in ui, the way I + +just expressed it. + +0 sij can be written as a Taylor +series expansion in 0 + +epsilon ij. + +This is the general +expression. + +Here we take the partial of +the stress at time t, with + +respect to the Green-Lagrange +strain at time t, here we are + +having this bar with the t +that denotes that we are + +actually doing this evaluation +at time t. + +And here we have an increment in +this strain, and of course, + +there are higher-order terms. + +These higher-order terms we will +neglect, and therefore we + +get directly for this stress +here, this expression. + +Notice we already have +substituted for 0 epsilon rs, + +these two quantities. + +This one here is quadratic in +ui, this one is linear in ui. + +And if we linearize this term, +we get directly this one here. + +Notice that this is the +appropriate stress-strain law + +that has to be used +corresponding + +to this stress measure. + +And we will later on talk more +about how we evaluate this + +stress-strain law. + +As an example, we may look +here at this schematic + +solution, computed solution, +over a number of time steps. + +We're going time 1, 2, 3, 4, +5, up to t minus delta + +t and then to t. + +The stress-strain law relates +basically the stress increment + +here to the strain increment. + +And notice it represents a +tangent to this this curve. + +This green line here is a +tangent to the red or the blue + +curve, the blue one now +overlapping the red curve + +right there. + +So we have here the tangent, or +the slope of this tangent + +is giving us the material +tensor 0c. + +Of course, here we're talking +just about one element. + +In general we have many elements +corresponding to the + +strain and stress measures +that we are dealing with. + +If we now substitute the result +that we just looked at + +into the general equation-- + +sorry to take this one down-- + +into the general equation here, +we see directly that + +this part here, of course, +is the stress. + +And this part here gives +us that part. + +We simply multiply out and look +at the individual terms. + +We notice that this one +does not contain ui. + +We notice that this one +is linear in ui. + +So since this one is already +linear in ui, this term will + +be quadratic in ui. + +We will have to drop it. + +This term here is linear in ui, +but this one is constant, + +so this total term +is linear in ui. + +And this is the one we keep, +and which is then the + +linearized result. + +In other words, in summary once +more, this total term + +here linearized is obtained +via this expression here. + +The final linearized equation +that we are then dealing with, + +now that we're substituting +all these results into the + +original equation that we have +developed, is as follows. + +Here we have one term that comes +from the incremental + +stress times the variation +on the total incremental + +Green-Lagrange strain. + +That all has reduced +to this term. + +Here we did not have to +linearize at all. + +We kept what we already had. + +And on the right hand side, +did not linearize either, + +because this was a term that we +had already there, and of + +course this is the external +virtual work. + +Now it's interesting to note +that these two terms here + +result into this expression, +where this is the tangent + +stiffness matrix. + +Notice that tangent stiffness +matrix contains the material + +tensor, as well as the +current stresses. + +This incremental displacement +here, vector, comes from this + +strain part and that +strain part. + +Notice that this virtual +displacement vector here comes + +from that strain part and +also from that one here. + +Below here we have, of course, +that the external virtual work + +results into a vector of nodal +point forces times these + +virtual displacements. + +And this one here results into +the force vector corresponding + +to the internal element +stresses. + +And this is, of course, a very +important quantity that we + +have to calculate accurately, +as I pointed out earlier. + +Because we want ultimately in +the iteration that this vector + +is equilibriating that vector, +and if we do make a mistake in + +calculating this vector, then +we might have converged, but + +we have converged to +the wrong solution. + +So it's very important to +recognize that this vector + +must be accurately calculated, +by all means. + +However, the k matrix here, if +we go back once more to the + +discussion of this matrix, the +k matrix here is a tangent + +stiffness matrix. + +And this tangent stiffness +matrix is selected such as to + +obtain, of course, in the +incremental solution, an + +appropriate incremental +displacement. + +We will see later on +that this matrix is + +updated in the iteration. + +It depends on what kind of +intuitive scheme we are using, + +depending on that scheme we +are updating this matrix + +differently. + +In any case, it's a matrix that +we will in quotes, "play + +around with", in order to +accelerate the convergence. + +Therefore there is no unique +matrix that can be used here, + +that should be used here. + +There are different +possibilities that we will + +discuss in later lectures. + +But on the right hand side once +again, this F vector is + +the F vector obtained from the +current stresses, and that one + +has to be calculated uniquely +in the correct way. + +Well, an important point is that +this relationship here on + +the left hand side, is equal to +the relationship given here + +on the right hand side. + +And this holds because +this term here is + +equal to that term. + +We interpret, in fact, this +right hand side as an out of + +balance virtual work term. + +Let's look once why this holds, +because this might be a + +bit of a surprise. + +The mathematical explanation +is given on this viewgraph. + +We had earlier already that +the variation on the total + +Green-Lagrange strain is +nothing else than the + +variation on the incremental +total Green-Lagrange strain. + +Now if we look down here, we +recognize that this variation + +here at ui equal to 0, is +nothing else than the + +variation on the Green-Lagrange + +strain at time t. + +If ui is zero, then this term +here is nothing else than the + +Green-Lagrange strain +at time t. + +So we're looking here at +the variation of the + +Green-Lagrange at time, t +if I put ui equal to 0. + +Now let's look at these +expressions here. + +If I evaluate this term here, at +ui equal to 0, we find that + +this term here, being a +constant, is recovered. + +But notice that this term here, +with ui equal to 0, + +simply turns out to be 0. + +Therefore, this term is +equal to that term. + +And this means, therefore, that +the variation on t zero + +epsilon ij is equal to the +variation on 0 eij, which we + +wanted to prove, of course. + +So this is the reason why this +term here is equal to that + +term, as we have used it on +the previous viewgraph. + +This result also makes physical +sense, because if we + +look at the governing equation, +we find that this + +term here, replaced, is +nothing else than tr. + +Should be tr. + +And of course, the script +r the external virtual + +work at time t. + +And this, of course, is here the +out of balance load term. + +Now if, for example, the +material is elastic, and the + +external virtual work has not +changed, then clearly the + +displacements would +not change. + +In other words, t plus delta tui +would be equal to tui, and + +the incremental displacements +would be 0. + +Therefore, equilibrium +would be satisfied. + +Hence, this term, which we have +here, must actually be + +equal to t 0 sij times variation +t 0 epsilon ij, the + +way we discussed it just now. + +We may rewrite the linearized +governing equation as given on + +this viewgraph. + +And I am rewriting it in this +form because we anticipate + +that we need an iteration. + +We simply introduce here, an +iteration counter 1, with the + +delta in front of the +incremental strain value. + +And similarly we introduce a +delta here, and an iteration + +counter 1 there. + +And on the right hand side, we +introduce also an iteration + +counter, but one lower. + +In other words, 0 here, whereas +we have a 1 there. + +Notice 0 here, a 1 here. + +And notice furthermore, that +this term is nothing else than + +that term, and this term here +is nothing else than the + +variation on t 0 epsilon ij. + +This would be the equation +that we have developed + +already, just having introduced +now a different + +notation which leads us towards +what we want to deal + +with in the iteration. + +The governing equations from a +finite element point of view, + +then would be as shown here. + +Notice tangent stiffness matrix, +del u1, iteration + +counter, the external loads, +which we still assume to be + +constant, by the way. + +We still assume deformation +independent loading if we have + +deformation dependent loading, +these would also + +change in the iteration. + +And here we have the vector +corresponding to the internal + +element stresses at time t. + +We write that vector as t +plus delta t 0, 0 there. + +And that means that we are +really talking, at this point, + +about this vector. + +We calculate this incremental +displacement vector and add it + +to the previous displacements, +which, of course, in this + +particular instance, in the +first iteration, are nothing + +else than tu. + +We add those, and obtain +our first estimates of + +displacements, namely the +estimate at the end of + +iteration 1. + +Having obtained now this +estimate on displacements, we + +can repeat the process. + +And that is shown here on +the next viewgraph. + +Notice that now I am talking +about the right hand side, + +about the Green-Lagrange strains +corresponding to time + +t plus delta t, and the +first iteration. + +In other words, these are the +Green-Lagrange strains + +corresponding to the end +of the first iteration. + +They include now the incremental +displacements that + +we just calculated. + +Similarly, these are the +stresses corresponding to the + +end of the first iteration. + +And this is an out of balance +virtual work term. + +If that is non-zero, we will +have further increment in + +displacements. + +And that increment results, +of course, into an + +increment of strains. + +Namely, the second increment. + +Here is the 2 that denotes +the increment. + +Here is the 2 that denotes +the increment. + +The finite element equations +then would look as shown here. + +Same equation as before, +but now with a 1 + +here and a 2 there. + +We calculate the incremental +displacements, we add them to + +what we had already and get a +better approximation to the + +displacements corresponding +to time t plus delta t. + +This process, of course, can now +be repeated, and on this + +viewgraph we show how +it's being done for + +every iteration k. + +In a particular iteration, we +have now on the right hand + +side the external virtual work +corresponding to time t plus + +delta t, the stresses +corresponding to time t plus + +delta t and iteration +k minus 1. + +At the end of iteration +k minus 1, the strains + +corresponding to time t plus +delta t, and at the end of + +iteration k minus 1. + +This is the out of balance +virtual work term, and on the + +left hand side we have the same +quantities as before, but + +now with the iteration +counter k. + +When discretized, we obtain +these equations here. + +Delta uk, the increment in the +iteration k of displacements, + +r minus f, computed, of course, +from the current + +displacements. + +From the current displacements +we calculate that vector here. + +Notice this vector is obtained +from this integral here. + +We repeat this process for +iteration k 1, 2, 3 et cetera + +until convergence. + +We will have to talk about +how we measure + +convergence and so on. + +But in this iteration we're +adding up the total + +incremental displacements to +obtain always a better + +estimate for the displacements +corresponding to time t plus + +delta t, and here, of +course, iteration k. + +Notice that the counter here +goes from j equals 1 to k, + +that is this j and this k, of +course, is nothing else than + +the k that we have on the +left hand side here. + +Notice once again that the first +iteration, when k is + +equal to 1, it amounts to +nothing else than what we + +discussed already at the very +beginning a little earlier in + +the lecture. + +We simply generalized that +discussion now to an equation + +in which we iterate and always +try to calculate another + +increment in displacements +until the right + +hand side is 0. + +Notice when the right hand +side is 0, the external + +virtual work is equilibrated by +the internal virtual work, + +and of course, that is what +we want to reach. + +That is what our criterion +is for the analysis. + +The external virtual work must +be equilibrated by the + +internal virtual work. + +In the finite element +discretization, the whole + +process is as summarized +on this viewgraph. + +Initially, we are given +tu, the displacements + +corresponding to time t, and the +externally applied loads + +corresponding to time +t plus delta t. + +We compute the stiffness matrix, +the tangent stiffness + +matrix corresponding +to time t. + +We calculate this vector, +the nodal point forces + +corresponding to the +stresses at time t. + +Notice this 0 here refers always +to the total Lagrangian + +formulation. + +Notice that this vector here +is really the initial + +condition for the iteration. + +Similar, the displacements +at time t are the initial + +conditions for the iteration +for the displacements. + +Zero here. + +Zero there, meaning the initial + +conditions for our iteration. + +We set the iteration counter, +k equal to 1, and we now go + +into the following loop. + +Notice on the right hand side, +an out of balance load vector + +is calculated. + +And that out of balance load +vector gives us an incremental + +displacement vector. + +Of course, the tangent stiffness +matrix is involved + +in that calculation. + +Notice that this incremental +displacement vector is added + +to the displacements that we had +previously calculated, to + +obtain a new estimate on +the displacements. + +And like that, we have now +obtained a displacement vector + +that, of course, hopefully is +closer to satisfying certain + +convergence criteria. + +We will have to talk about +these convergence + +criteria later on. + +Basically, we check whether +equilibrium is satisfied + +within a certain tolerance. + +If the equilibrium is not +satisfied, we go here. + +We use these displacements that +we just have calculated + +to compute a new vector +of nodal point forces + +corresponding to the +element stresses. + +Notice this vector now contains +the information that + +we have just calculated in +solving this equation here. + +This was information +that we obtained. + +And that information is +contained in this vector, and + +that vector is used right here +to calculate this nodal point + +force vector. + +Having calculated that, we +increase our iteration + +counter, come back here and +like that we continue the + +iteration, looping around +through here + +as I have just described. + +Notice at convergence once +again, we want, of course, + +that r is equal to f, meaning +that the external loads are + +equilibrated by the nodal point +forces corresponding to + +the internal element stresses. + +Well, this brings us to the +end of this lecture. + +You might recognize that this +last viewgraph really contains + +a lot of information that, of +course, we discussed in this + +lecture, but that also I +referred to already in the + +first lecture. + +At that time, I tried to +introduce you to this + +iteration process using rather +physical concepts, not going + +through a lengthy mathematical +derivation. + +We did not talk about continuum +mechanics variables. + +We did not talk about total +Lagrangian formulation, second + +Piola-Kirchhoff stresses, +Green-Lagrange + +strains and so on. + +I hoped at that time to give +you just a physical feel of + +how we are iterating. + +The same kind of equations, the +same equations we looked + +at at that time, now I hope +with this lecture, I have + +given you the mathematical +basis of these equations. + +I hope you have learned how to +derive these equations, how to + +work with these equations +a little bit. + +And in some of the next +lectures, we will look at how + +actually we do construct +this k matrix + +for different elements. + +That is, of course, a very +important consideration. + +How do we calculate this +k matrix for 1D, 2D, 3D + +elements, shell elements, +beam elements? + +How do we calculate this +force vector for + +these different elements? + +We will have to discuss +that as well. + +Notice that in this k matrix +goes the material law. + +Whether we are dealing with an +elasto-plastic material, + +rubber type material, all that +will affect the actual + +ingredients, the +actual elements + +here in that k matrix. + +We we also have to discuss how +we can possibly make this + +convergence that I'm +talking about fast. + +In other words, how can we +accelerate the convergence of + +these iterations? + +So in essence, I like to just +convey to you that what you + +see here you will see a +number of times again. + +We will talk about the different +parts that you have + +been looking at here already +briefly once again in the + +upcoming lectures. + +Thank you very much for +your attention. \ No newline at end of file diff --git a/4U9B9YgEqe4.txt b/4U9B9YgEqe4.txt new file mode 100644 index 0000000000000000000000000000000000000000..dc97471cd94eca13ca90ac6829ca558dce0c86c1 --- /dev/null +++ b/4U9B9YgEqe4.txt @@ -0,0 +1,499 @@ +align:start position:0% + +welcome back to 820 special relativity + + align:start position:0% +welcome back to 820 special relativity + + + align:start position:0% +welcome back to 820 special relativity +so if there is a time dilation effect + + align:start position:0% +so if there is a time dilation effect + + + align:start position:0% +so if there is a time dilation effect +through gravitational fields + + align:start position:0% +through gravitational fields + + + align:start position:0% +through gravitational fields +then there is also a redshift to the + + align:start position:0% +then there is also a redshift to the + + + align:start position:0% +then there is also a redshift to the +gravitational fields + + align:start position:0% +gravitational fields + + + align:start position:0% +gravitational fields +so a consequence of time dilation is a + + align:start position:0% +so a consequence of time dilation is a + + + align:start position:0% +so a consequence of time dilation is a +change in the light frequency and i ask + + align:start position:0% +change in the light frequency and i ask + + + align:start position:0% +change in the light frequency and i ask +you to estimate the magnitude of this + + align:start position:0% +you to estimate the magnitude of this + + + align:start position:0% +you to estimate the magnitude of this +effect + + align:start position:0% +effect + + + align:start position:0% +effect +and the example you want to use is the + + align:start position:0% +and the example you want to use is the + + + align:start position:0% +and the example you want to use is the +one shown here so you have a tower which + + align:start position:0% +one shown here so you have a tower which + + + align:start position:0% +one shown here so you have a tower which +is + + align:start position:0% +is + + + align:start position:0% +is +not randomly but 22 and a half meters + + align:start position:0% +not randomly but 22 and a half meters + + + align:start position:0% +not randomly but 22 and a half meters +tall + + align:start position:0% +tall + + + align:start position:0% +tall +and + + align:start position:0% +and + + + align:start position:0% +and +a light beam is sent down + + align:start position:0% +a light beam is sent down + + + align:start position:0% +a light beam is sent down +obviously the tower is built on this + + align:start position:0% +obviously the tower is built on this + + + align:start position:0% +obviously the tower is built on this +planet and this there's gravity is + + align:start position:0% +planet and this there's gravity is + + + align:start position:0% +planet and this there's gravity is +acting + + align:start position:0% +acting + + + align:start position:0% +acting +um so this this is basically an + + align:start position:0% +um so this this is basically an + + + align:start position:0% +um so this this is basically an +accelerating + + align:start position:0% +accelerating + + + align:start position:0% +accelerating +um reference frame + + align:start position:0% +um reference frame + + + align:start position:0% +um reference frame +the length of the tower is again 22 + + align:start position:0% +the length of the tower is again 22 + + + align:start position:0% +the length of the tower is again 22 +meters and i would like you to just get + + align:start position:0% +meters and i would like you to just get + + + align:start position:0% +meters and i would like you to just get +a feeling + + align:start position:0% +a feeling + + + align:start position:0% +a feeling +how big can this effect be the effect of + + align:start position:0% +how big can this effect be the effect of + + + align:start position:0% +how big can this effect be the effect of +redshift here + + align:start position:0% +redshift here + + + align:start position:0% +redshift here +so please try to work this out + + align:start position:0% +so please try to work this out + + + align:start position:0% +so please try to work this out +the way to to think about this is first + + align:start position:0% +the way to to think about this is first + + + align:start position:0% +the way to to think about this is first +to say okay now the light you know the + + align:start position:0% +to say okay now the light you know the + + + align:start position:0% +to say okay now the light you know the +delta t for the light to travel + + align:start position:0% +delta t for the light to travel + + + align:start position:0% +delta t for the light to travel +um is l divided by c the speed of light + + align:start position:0% +um is l divided by c the speed of light + + + align:start position:0% +um is l divided by c the speed of light +is c the length is l + + align:start position:0% +is c the length is l + + + align:start position:0% +is c the length is l +the change in velocity + + align:start position:0% +the change in velocity + + + align:start position:0% +the change in velocity +is + + align:start position:0% +is + + + align:start position:0% +is +g + + align:start position:0% +g + + + align:start position:0% +g +acceleration times l divided by c + + align:start position:0% +acceleration times l divided by c + + + align:start position:0% +acceleration times l divided by c +so the doppler shift then is the + + align:start position:0% +so the doppler shift then is the + + + align:start position:0% +so the doppler shift then is the +frequency the new frequency divided by + + align:start position:0% +frequency the new frequency divided by + + + align:start position:0% +frequency the new frequency divided by +the initial frequency + + align:start position:0% +the initial frequency + + + align:start position:0% +the initial frequency +and that can be approximated by one plus + + align:start position:0% +and that can be approximated by one plus + + + align:start position:0% +and that can be approximated by one plus +delta v over c so we find that it's one + + align:start position:0% +delta v over c so we find that it's one + + + align:start position:0% +delta v over c so we find that it's one +plus + + align:start position:0% +plus + + + align:start position:0% +plus +g times l over c square + + align:start position:0% +g times l over c square + + + align:start position:0% +g times l over c square +now the speed of light is pretty fast + + align:start position:0% +now the speed of light is pretty fast + + + align:start position:0% +now the speed of light is pretty fast +um three times ten to the um to the nine + + align:start position:0% +um three times ten to the um to the nine + + + align:start position:0% +um three times ten to the um to the nine +meter per second + + align:start position:0% +meter per second + + + align:start position:0% +meter per second +and this distance is only 22 and a half + + align:start position:0% +and this distance is only 22 and a half + + + align:start position:0% +and this distance is only 22 and a half +meters so we find that this is a tiny + + align:start position:0% +meters so we find that this is a tiny + + + align:start position:0% +meters so we find that this is a tiny +tiny tiny effect but nevertheless + + align:start position:0% +tiny tiny effect but nevertheless + + + align:start position:0% +tiny tiny effect but nevertheless +um + + align:start position:0% +um + + + align:start position:0% +um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +experimentalists at harvard tested this + + align:start position:0% +experimentalists at harvard tested this + + + align:start position:0% +experimentalists at harvard tested this +effect the pound replica and snyder in + + align:start position:0% +effect the pound replica and snyder in + + + align:start position:0% +effect the pound replica and snyder in +the 1950s and 50s and 60s were able to + + align:start position:0% +the 1950s and 50s and 60s were able to + + + align:start position:0% +the 1950s and 50s and 60s were able to +show this this very tiny um effect + + align:start position:0% +show this this very tiny um effect + + + align:start position:0% +show this this very tiny um effect +you want to know more about this you can + + align:start position:0% +you want to know more about this you can + + + align:start position:0% +you want to know more about this you can +for example look up a small description + + align:start position:0% +for example look up a small description + + + align:start position:0% +for example look up a small description +in wikipedia here + + align:start position:0% +in wikipedia here + + + align:start position:0% +in wikipedia here +but there's + + align:start position:0% +but there's + + + align:start position:0% +but there's +some quite some literature on those + + align:start position:0% +some quite some literature on those + + + align:start position:0% +some quite some literature on those +experimental tests + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/57uqU8G_z0E.txt b/57uqU8G_z0E.txt new file mode 100644 index 0000000000000000000000000000000000000000..cc52302e535e7e8e6a175553bea0fc879fc18e41 --- /dev/null +++ b/57uqU8G_z0E.txt @@ -0,0 +1,4019 @@ +align:start position:0% + +a long 15 minutes + + align:start position:0% + + + + align:start position:0% + +there you go all right hello everybody + + align:start position:0% +there you go all right hello everybody + + + align:start position:0% +there you go all right hello everybody +my name is henry and today i'll be + + align:start position:0% +my name is henry and today i'll be + + + align:start position:0% +my name is henry and today i'll be +presenting my findings on an experiment + + align:start position:0% +presenting my findings on an experiment + + + align:start position:0% +presenting my findings on an experiment +that i conducted with my + + align:start position:0% +that i conducted with my + + + align:start position:0% +that i conducted with my +lab partner adeen over there thank you + + align:start position:0% +lab partner adeen over there thank you + + + align:start position:0% +lab partner adeen over there thank you +edin during our experiment we determined + + align:start position:0% +edin during our experiment we determined + + + align:start position:0% +edin during our experiment we determined +the angular + + align:start position:0% +the angular + + + align:start position:0% +the angular +dependency of the scattering rate of + + align:start position:0% +dependency of the scattering rate of + + + align:start position:0% +dependency of the scattering rate of +alpha particles + + align:start position:0% +alpha particles + + + align:start position:0% +alpha particles +through gold foil using this relation we + + align:start position:0% +through gold foil using this relation we + + + align:start position:0% +through gold foil using this relation we +are able to determine that rutherford + + align:start position:0% +are able to determine that rutherford + + + align:start position:0% +are able to determine that rutherford +scattering + + align:start position:0% +scattering + + + align:start position:0% +scattering +presents an accurate model for this + + align:start position:0% +presents an accurate model for this + + + align:start position:0% +presents an accurate model for this +these scattering + + align:start position:0% +these scattering + + + align:start position:0% +these scattering +effects in doing so we are able to + + align:start position:0% +effects in doing so we are able to + + + align:start position:0% +effects in doing so we are able to +extract some information + + align:start position:0% +extract some information + + + align:start position:0% +extract some information +about the actual nature of atoms and + + align:start position:0% +about the actual nature of atoms and + + + align:start position:0% +about the actual nature of atoms and +their atomic makeup + + align:start position:0% +their atomic makeup + + + align:start position:0% +their atomic makeup +so to give a bit of background i'm going + + align:start position:0% +so to give a bit of background i'm going + + + align:start position:0% +so to give a bit of background i'm going +to go through two different historical + + align:start position:0% +to go through two different historical + + + align:start position:0% +to go through two different historical +models of the atom + + align:start position:0% +models of the atom + + + align:start position:0% +models of the atom +and talk about the different + + align:start position:0% +and talk about the different + + + align:start position:0% +and talk about the different +experimental predictions that they + + align:start position:0% +experimental predictions that they + + + align:start position:0% +experimental predictions that they +uh predict so back in the early 19th + + align:start position:0% +uh predict so back in the early 19th + + + align:start position:0% +uh predict so back in the early 19th +century people weren't too sure what + + align:start position:0% +century people weren't too sure what + + + align:start position:0% +century people weren't too sure what +made up an atom + + align:start position:0% +made up an atom + + + align:start position:0% +made up an atom +they knew there are some electrons and + + align:start position:0% +they knew there are some electrons and + + + align:start position:0% +they knew there are some electrons and +some positive stuff going around + + align:start position:0% +some positive stuff going around + + + align:start position:0% +some positive stuff going around +somewhere but other than that + + align:start position:0% +somewhere but other than that + + + align:start position:0% +somewhere but other than that +they weren't too sure now the + + align:start position:0% +they weren't too sure now the + + + align:start position:0% +they weren't too sure now the +predominant theory at the time was jj + + align:start position:0% +predominant theory at the time was jj + + + align:start position:0% +predominant theory at the time was jj +thompson's plum pudding model + + align:start position:0% +thompson's plum pudding model + + + align:start position:0% +thompson's plum pudding model +shown here in this model you have these + + align:start position:0% +shown here in this model you have these + + + align:start position:0% +shown here in this model you have these +negatively charged electrons that sort + + align:start position:0% +negatively charged electrons that sort + + + align:start position:0% +negatively charged electrons that sort +of float around in this soup + + align:start position:0% +of float around in this soup + + + align:start position:0% +of float around in this soup +of positive charge i apologize for the + + align:start position:0% +of positive charge i apologize for the + + + align:start position:0% +of positive charge i apologize for the +plum pudding in the soup + + align:start position:0% +plum pudding in the soup + + + align:start position:0% +plum pudding in the soup +if you're getting hungry from all these + + align:start position:0% +if you're getting hungry from all these + + + align:start position:0% +if you're getting hungry from all these +metaphors there is food back there + + align:start position:0% +metaphors there is food back there + + + align:start position:0% +metaphors there is food back there +now the the the experimental predictions + + align:start position:0% +now the the the experimental predictions + + + align:start position:0% +now the the the experimental predictions +that we want to get out of this model + + align:start position:0% +that we want to get out of this model + + + align:start position:0% +that we want to get out of this model +is what it says about scattering so if + + align:start position:0% +is what it says about scattering so if + + + align:start position:0% +is what it says about scattering so if +we take one of these atoms and we shoot + + align:start position:0% +we take one of these atoms and we shoot + + + align:start position:0% +we take one of these atoms and we shoot +it through a material made up of other + + align:start position:0% +it through a material made up of other + + + align:start position:0% +it through a material made up of other +atoms + + align:start position:0% +atoms + + + align:start position:0% +atoms +what kind of scattering do we expect to + + align:start position:0% +what kind of scattering do we expect to + + + align:start position:0% +what kind of scattering do we expect to +see and you can see in this model here + + align:start position:0% +see and you can see in this model here + + + align:start position:0% +see and you can see in this model here +we don't really expect that much + + align:start position:0% +we don't really expect that much + + + align:start position:0% +we don't really expect that much +scattering so the atom will go through + + align:start position:0% +scattering so the atom will go through + + + align:start position:0% +scattering so the atom will go through +it might pass through a you know a + + align:start position:0% +it might pass through a you know a + + + align:start position:0% +it might pass through a you know a +slightly more negatively charged region + + align:start position:0% +slightly more negatively charged region + + + align:start position:0% +slightly more negatively charged region +here and move a bit that way + + align:start position:0% +here and move a bit that way + + + align:start position:0% +here and move a bit that way +deflect a little bit that way but you + + align:start position:0% +deflect a little bit that way but you + + + align:start position:0% +deflect a little bit that way but you +don't expect that much scattering + + align:start position:0% +don't expect that much scattering + + + align:start position:0% +don't expect that much scattering +overall + + align:start position:0% +overall + + + align:start position:0% +overall +doing out all the math we see that this + + align:start position:0% +doing out all the math we see that this + + + align:start position:0% +doing out all the math we see that this +predicts + + align:start position:0% +predicts + + + align:start position:0% +predicts +small angle scattering that dies off + + align:start position:0% +small angle scattering that dies off + + + align:start position:0% +small angle scattering that dies off +exponentially + + align:start position:0% +exponentially + + + align:start position:0% +exponentially +as a function of angle this dying off is + + align:start position:0% +as a function of angle this dying off is + + + align:start position:0% +as a function of angle this dying off is +controlled by this + + align:start position:0% +controlled by this + + + align:start position:0% +controlled by this +theta sub m called the mean multiple + + align:start position:0% +theta sub m called the mean multiple + + + align:start position:0% +theta sub m called the mean multiple +scattering rate + + align:start position:0% +scattering rate + + + align:start position:0% +scattering rate +for gold we predict this is about one + + align:start position:0% +for gold we predict this is about one + + + align:start position:0% +for gold we predict this is about one +so rutherford comes along and he looks + + align:start position:0% +so rutherford comes along and he looks + + + align:start position:0% +so rutherford comes along and he looks +at this and says ah + + align:start position:0% +at this and says ah + + + align:start position:0% +at this and says ah +i don't know about this let me try + + align:start position:0% +i don't know about this let me try + + + align:start position:0% +i don't know about this let me try +something else + + align:start position:0% +something else + + + align:start position:0% +something else +this right here is the rutherford model + + align:start position:0% +this right here is the rutherford model + + + align:start position:0% +this right here is the rutherford model +that he proposes in this model we have + + align:start position:0% +that he proposes in this model we have + + + align:start position:0% +that he proposes in this model we have +our negatively charged electrons + + align:start position:0% +our negatively charged electrons + + + align:start position:0% +our negatively charged electrons +but instead of this soup of positive + + align:start position:0% +but instead of this soup of positive + + + align:start position:0% +but instead of this soup of positive +charge we have a densely + + align:start position:0% +charge we have a densely + + + align:start position:0% +charge we have a densely +packed nucleus in the middle now because + + align:start position:0% +packed nucleus in the middle now because + + + align:start position:0% +packed nucleus in the middle now because +this nucleus is so + + align:start position:0% +this nucleus is so + + + align:start position:0% +this nucleus is so +dense and so tightly packed it allows + + align:start position:0% +dense and so tightly packed it allows + + + align:start position:0% +dense and so tightly packed it allows +for much stronger interactions between + + align:start position:0% +for much stronger interactions between + + + align:start position:0% +for much stronger interactions between +atoms when it comes to scattering + + align:start position:0% +atoms when it comes to scattering + + + align:start position:0% +atoms when it comes to scattering +for example you can imagine if two atoms + + align:start position:0% +for example you can imagine if two atoms + + + align:start position:0% +for example you can imagine if two atoms +collided + + align:start position:0% +collided + + + align:start position:0% +collided +the the the nuclei would interact and + + align:start position:0% +the the the nuclei would interact and + + + align:start position:0% +the the the nuclei would interact and +they just bounce + + align:start position:0% +they just bounce + + + align:start position:0% +they just bounce +straight off so doing now all the math + + align:start position:0% +straight off so doing now all the math + + + align:start position:0% +straight off so doing now all the math +again we see + + align:start position:0% +again we see + + + align:start position:0% +again we see +that this large this larger scattering + + align:start position:0% +that this large this larger scattering + + + align:start position:0% +that this large this larger scattering +angle + + align:start position:0% +angle + + + align:start position:0% +angle +dies off as one over sine to the fourth + + align:start position:0% +dies off as one over sine to the fourth + + + align:start position:0% +dies off as one over sine to the fourth +of theta over two now this predicts much + + align:start position:0% +of theta over two now this predicts much + + + align:start position:0% +of theta over two now this predicts much +higher rate + + align:start position:0% +higher rate + + + align:start position:0% +higher rate +at larger angles than this exponential + + align:start position:0% +at larger angles than this exponential + + + align:start position:0% +at larger angles than this exponential +falloff right here + + align:start position:0% +falloff right here + + + align:start position:0% +falloff right here +a small point to clarify about this + + align:start position:0% +a small point to clarify about this + + + align:start position:0% +a small point to clarify about this +equation here is that this equation is + + align:start position:0% +equation here is that this equation is + + + align:start position:0% +equation here is that this equation is +derived assuming large angles so for + + align:start position:0% +derived assuming large angles so for + + + align:start position:0% +derived assuming large angles so for +theta roughly larger than or equal to + + align:start position:0% +theta roughly larger than or equal to + + + align:start position:0% +theta roughly larger than or equal to +10. this is not a limit of the + + align:start position:0% +10. this is not a limit of the + + + align:start position:0% +10. this is not a limit of the +rutherford theory in and of itself + + align:start position:0% +rutherford theory in and of itself + + + align:start position:0% +rutherford theory in and of itself +you can derive a rutherford model for + + align:start position:0% +you can derive a rutherford model for + + + align:start position:0% +you can derive a rutherford model for +scattering for any angle + + align:start position:0% +scattering for any angle + + + align:start position:0% +scattering for any angle +but it starts to get really gross at + + align:start position:0% +but it starts to get really gross at + + + align:start position:0% +but it starts to get really gross at +small angles + + align:start position:0% +small angles + + + align:start position:0% +small angles +you can actually see this this diverges + + align:start position:0% +you can actually see this this diverges + + + align:start position:0% +you can actually see this this diverges +for theta equals to zero which is not + + align:start position:0% +for theta equals to zero which is not + + + align:start position:0% +for theta equals to zero which is not +good + + align:start position:0% +good + + + align:start position:0% +good +so this equation right here is only + + align:start position:0% +so this equation right here is only + + + align:start position:0% +so this equation right here is only +valid for theta roughly greater than or + + align:start position:0% +valid for theta roughly greater than or + + + align:start position:0% +valid for theta roughly greater than or +equal to ten + + align:start position:0% +equal to ten + + + align:start position:0% +equal to ten +so for the purposes of this experiment + + align:start position:0% +so for the purposes of this experiment + + + align:start position:0% +so for the purposes of this experiment +we will restrict our viewing + + align:start position:0% +we will restrict our viewing + + + align:start position:0% +we will restrict our viewing +to theta greater than or equal to ten + + align:start position:0% +to theta greater than or equal to ten + + + align:start position:0% +to theta greater than or equal to ten +and these two models give us two + + align:start position:0% +and these two models give us two + + + align:start position:0% +and these two models give us two +different predictions that we can + + align:start position:0% +different predictions that we can + + + align:start position:0% +different predictions that we can +compare + + align:start position:0% +compare + + + align:start position:0% +compare +against actual data so we experi we + + align:start position:0% +against actual data so we experi we + + + align:start position:0% +against actual data so we experi we +experimentally measure scattering rates + + align:start position:0% +experimentally measure scattering rates + + + align:start position:0% +experimentally measure scattering rates +at various angles and by taking this + + align:start position:0% +at various angles and by taking this + + + align:start position:0% +at various angles and by taking this +data we can fit it + + align:start position:0% +data we can fit it + + + align:start position:0% +data we can fit it +to both the predicted rutherford and + + align:start position:0% +to both the predicted rutherford and + + + align:start position:0% +to both the predicted rutherford and +thomson model and come to a conclusion + + align:start position:0% +thomson model and come to a conclusion + + + align:start position:0% +thomson model and come to a conclusion +about which one more accurately predicts + + align:start position:0% +about which one more accurately predicts + + + align:start position:0% +about which one more accurately predicts +our model + + align:start position:0% +our model + + + align:start position:0% +our model +now let's talk a bit about the apparatus + + align:start position:0% +now let's talk a bit about the apparatus + + + align:start position:0% +now let's talk a bit about the apparatus +that lets us do this the first part of + + align:start position:0% +that lets us do this the first part of + + + align:start position:0% +that lets us do this the first part of +our apparatus is an alpha particle + + align:start position:0% +our apparatus is an alpha particle + + + align:start position:0% +our apparatus is an alpha particle +howitzer + + align:start position:0% +howitzer + + + align:start position:0% +howitzer +this howitzer contains an americium-241 + + align:start position:0% +this howitzer contains an americium-241 + + + align:start position:0% +this howitzer contains an americium-241 +source + + align:start position:0% +source + + + align:start position:0% +source +which emits alpha particles which are + + align:start position:0% +which emits alpha particles which are + + + align:start position:0% +which emits alpha particles which are +two protons and two neutrons + + align:start position:0% +two protons and two neutrons + + + align:start position:0% +two protons and two neutrons +at approximately a constant energy these + + align:start position:0% +at approximately a constant energy these + + + align:start position:0% +at approximately a constant energy these +alpha particles shoot out of the + + align:start position:0% +alpha particles shoot out of the + + + align:start position:0% +alpha particles shoot out of the +howitzer right here in a sort of + + align:start position:0% +howitzer right here in a sort of + + + align:start position:0% +howitzer right here in a sort of +concentrated beam + + align:start position:0% +concentrated beam + + + align:start position:0% +concentrated beam +directed out of the howitzer + + align:start position:0% +directed out of the howitzer + + + align:start position:0% +directed out of the howitzer +these alpha particles hit a gold foil + + align:start position:0% +these alpha particles hit a gold foil + + + align:start position:0% +these alpha particles hit a gold foil +where something happens + + align:start position:0% +where something happens + + + align:start position:0% +where something happens +we don't know yet and it scatters off at + + align:start position:0% +we don't know yet and it scatters off at + + + align:start position:0% +we don't know yet and it scatters off at +an angle theta + + align:start position:0% +an angle theta + + + align:start position:0% +an angle theta +which is then detected by our solid + + align:start position:0% +which is then detected by our solid + + + align:start position:0% +which is then detected by our solid +state detector this detector registers + + align:start position:0% +state detector this detector registers + + + align:start position:0% +state detector this detector registers +the count as well as the energy of the + + align:start position:0% +the count as well as the energy of the + + + align:start position:0% +the count as well as the energy of the +incoming particle + + align:start position:0% +incoming particle + + + align:start position:0% +incoming particle +and sends it to an mca to be analyzed + + align:start position:0% +and sends it to an mca to be analyzed + + + align:start position:0% +and sends it to an mca to be analyzed +now there's a bit of a complication in + + align:start position:0% +now there's a bit of a complication in + + + align:start position:0% +now there's a bit of a complication in +the geometry of our setup + + align:start position:0% +the geometry of our setup + + + align:start position:0% +the geometry of our setup +you see what we want to measure is this + + align:start position:0% +you see what we want to measure is this + + + align:start position:0% +you see what we want to measure is this +angle theta here our scattering rate + + align:start position:0% +angle theta here our scattering rate + + + align:start position:0% +angle theta here our scattering rate +what we actually control in what we + + align:start position:0% +what we actually control in what we + + + align:start position:0% +what we actually control in what we +measure in our experiments + + align:start position:0% +measure in our experiments + + + align:start position:0% +measure in our experiments +is this angle phi which is the angle of + + align:start position:0% +is this angle phi which is the angle of + + + align:start position:0% +is this angle phi which is the angle of +our howitzer relative to our detector + + align:start position:0% +our howitzer relative to our detector + + + align:start position:0% +our howitzer relative to our detector +so at ph equals to zero the howitzer + + align:start position:0% +so at ph equals to zero the howitzer + + + align:start position:0% +so at ph equals to zero the howitzer +points dead on at our detector + + align:start position:0% +points dead on at our detector + + + align:start position:0% +points dead on at our detector +now in a sort of theoretical world + + align:start position:0% +now in a sort of theoretical world + + + align:start position:0% +now in a sort of theoretical world +where this solid state detector is + + align:start position:0% +where this solid state detector is + + + align:start position:0% +where this solid state detector is +infinitesimally small + + align:start position:0% +infinitesimally small + + + align:start position:0% +infinitesimally small +and our beam is also this + + align:start position:0% +and our beam is also this + + + align:start position:0% +and our beam is also this +infinitesimally point source + + align:start position:0% +infinitesimally point source + + + align:start position:0% +infinitesimally point source +we would expect fee to correspond + + align:start position:0% +we would expect fee to correspond + + + align:start position:0% +we would expect fee to correspond +exactly to theta so if equals to zero + + align:start position:0% +exactly to theta so if equals to zero + + + align:start position:0% +exactly to theta so if equals to zero +the howitzer pointed dead on + + align:start position:0% +the howitzer pointed dead on + + + align:start position:0% +the howitzer pointed dead on +we would expect any non-zero scattering + + align:start position:0% +we would expect any non-zero scattering + + + align:start position:0% +we would expect any non-zero scattering +to cause the particles to shoot off in a + + align:start position:0% +to cause the particles to shoot off in a + + + align:start position:0% +to cause the particles to shoot off in a +direction + + align:start position:0% +direction + + + align:start position:0% +direction +and not be detected by our detector + + align:start position:0% +and not be detected by our detector + + + align:start position:0% +and not be detected by our detector +however in practice this is not actually + + align:start position:0% +however in practice this is not actually + + + align:start position:0% +however in practice this is not actually +the case + + align:start position:0% +the case + + + align:start position:0% +the case +our solid state detector is a few + + align:start position:0% +our solid state detector is a few + + + align:start position:0% +our solid state detector is a few +centimeters wide + + align:start position:0% +centimeters wide + + + align:start position:0% +centimeters wide +and because of this it allows for a + + align:start position:0% +and because of this it allows for a + + + align:start position:0% +and because of this it allows for a +range of angles theta + + align:start position:0% +range of angles theta + + + align:start position:0% +range of angles theta +that are detected given a certain + + align:start position:0% +that are detected given a certain + + + align:start position:0% +that are detected given a certain +howitzer angle in addition + + align:start position:0% +howitzer angle in addition + + + align:start position:0% +howitzer angle in addition +our beam has some width which allows for + + align:start position:0% +our beam has some width which allows for + + + align:start position:0% +our beam has some width which allows for +further + + align:start position:0% +further + + + align:start position:0% +further +angles that can be detected given a + + align:start position:0% +angles that can be detected given a + + + align:start position:0% +angles that can be detected given a +certain howitzer angle fee + + align:start position:0% +certain howitzer angle fee + + + align:start position:0% +certain howitzer angle fee +so this is a bunch of stuff going on we + + align:start position:0% +so this is a bunch of stuff going on we + + + align:start position:0% +so this is a bunch of stuff going on we +got a lot of different things + + align:start position:0% +got a lot of different things + + + align:start position:0% +got a lot of different things +contributing to uncertainty + + align:start position:0% +contributing to uncertainty + + + align:start position:0% +contributing to uncertainty +but we can account for this by + + align:start position:0% +but we can account for this by + + + align:start position:0% +but we can account for this by +essentially asking the simple question + + align:start position:0% +essentially asking the simple question + + + align:start position:0% +essentially asking the simple question +all right we have our howitzer at an + + align:start position:0% +all right we have our howitzer at an + + + align:start position:0% +all right we have our howitzer at an +angle fee what is the probability of a + + align:start position:0% +angle fee what is the probability of a + + + align:start position:0% +angle fee what is the probability of a +detection that we see + + align:start position:0% +detection that we see + + + align:start position:0% +detection that we see +having been having come from a particle + + align:start position:0% +having been having come from a particle + + + align:start position:0% +having been having come from a particle +being scattered at an angle theta + + align:start position:0% +being scattered at an angle theta + + + align:start position:0% +being scattered at an angle theta +again in this theoretical case where we + + align:start position:0% +again in this theoretical case where we + + + align:start position:0% +again in this theoretical case where we +have point sources and point detectors + + align:start position:0% +have point sources and point detectors + + + align:start position:0% +have point sources and point detectors +this probability would just correspond + + align:start position:0% +this probability would just correspond + + + align:start position:0% +this probability would just correspond +to a delta function centered at v + + align:start position:0% +to a delta function centered at v + + + align:start position:0% +to a delta function centered at v +however this is not practically the case + + align:start position:0% +however this is not practically the case + + + align:start position:0% +however this is not practically the case +and + + align:start position:0% +and + + + align:start position:0% +and +from simple geometric considerations + + align:start position:0% +from simple geometric considerations + + + align:start position:0% +from simple geometric considerations +which i can go into more detail later + + align:start position:0% +which i can go into more detail later + + + align:start position:0% +which i can go into more detail later +we expect as a first approximation a + + align:start position:0% +we expect as a first approximation a + + + align:start position:0% +we expect as a first approximation a +sort of triangle-shaped + + align:start position:0% +sort of triangle-shaped + + + align:start position:0% +sort of triangle-shaped +distribution around phi this is called + + align:start position:0% +distribution around phi this is called + + + align:start position:0% +distribution around phi this is called +the angular response function + + align:start position:0% +the angular response function + + + align:start position:0% +the angular response function +and we determine it by removing the gold + + align:start position:0% +and we determine it by removing the gold + + + align:start position:0% +and we determine it by removing the gold +foil from our detector so we just have + + align:start position:0% +foil from our detector so we just have + + + align:start position:0% +foil from our detector so we just have +our howitzer + + align:start position:0% +our howitzer + + + align:start position:0% +our howitzer +and our detector and we see how + + align:start position:0% +and our detector and we see how + + + align:start position:0% +and our detector and we see how +deviations in our + + align:start position:0% +deviations in our + + + align:start position:0% +deviations in our +fee affect our counting rates now again + + align:start position:0% +fee affect our counting rates now again + + + align:start position:0% +fee affect our counting rates now again +in + + align:start position:0% +in + + + align:start position:0% +in +to reference back in this theoretical + + align:start position:0% +to reference back in this theoretical + + + align:start position:0% +to reference back in this theoretical +scenario with point charges + + align:start position:0% +scenario with point charges + + + align:start position:0% +scenario with point charges +or point sources and point detectors we + + align:start position:0% +or point sources and point detectors we + + + align:start position:0% +or point sources and point detectors we +would expect to only see counts at + + align:start position:0% +would expect to only see counts at + + + align:start position:0% +would expect to only see counts at +fee equals to zero with our howitzer + + align:start position:0% +fee equals to zero with our howitzer + + + align:start position:0% +fee equals to zero with our howitzer +pointed dead on the detector + + align:start position:0% +pointed dead on the detector + + + align:start position:0% +pointed dead on the detector +and as soon as we move it a little bit + + align:start position:0% +and as soon as we move it a little bit + + + align:start position:0% +and as soon as we move it a little bit +the counts go away however this is not + + align:start position:0% +the counts go away however this is not + + + align:start position:0% +the counts go away however this is not +actually the case and by measuring these + + align:start position:0% +actually the case and by measuring these + + + align:start position:0% +actually the case and by measuring these +deviations we can determine our angular + + align:start position:0% +deviations we can determine our angular + + + align:start position:0% +deviations we can determine our angular +response function + + align:start position:0% +response function + + + align:start position:0% +response function +so we move our howitzer around we + + align:start position:0% +so we move our howitzer around we + + + align:start position:0% +so we move our howitzer around we +determine how our angle fee + + align:start position:0% +determine how our angle fee + + + align:start position:0% +determine how our angle fee +affects our counts and we get something + + align:start position:0% +affects our counts and we get something + + + align:start position:0% +affects our counts and we get something +like this + + align:start position:0% +like this + + + align:start position:0% +like this +this is fitted to a triangle + + align:start position:0% +this is fitted to a triangle + + + align:start position:0% +this is fitted to a triangle +distribution now we can take a few + + align:start position:0% +distribution now we can take a few + + + align:start position:0% +distribution now we can take a few +things out of this + + align:start position:0% +things out of this + + + align:start position:0% +things out of this +i see a fellow in the crowd laughing at + + align:start position:0% +i see a fellow in the crowd laughing at + + + align:start position:0% +i see a fellow in the crowd laughing at +my chi-squared + + align:start position:0% +my chi-squared + + + align:start position:0% +my chi-squared +the chi-squared is not that good this is + + align:start position:0% +the chi-squared is not that good this is + + + align:start position:0% +the chi-squared is not that good this is +because + + align:start position:0% +because + + + align:start position:0% +because +we we acknowledge that a triangle is + + align:start position:0% +we we acknowledge that a triangle is + + + align:start position:0% +we we acknowledge that a triangle is +only a first approximation we don't + + align:start position:0% +only a first approximation we don't + + + align:start position:0% +only a first approximation we don't +expect + + align:start position:0% +expect + + + align:start position:0% +expect +our data to actually perfectly model + + align:start position:0% +our data to actually perfectly model + + + align:start position:0% +our data to actually perfectly model +this triangle + + align:start position:0% +this triangle + + + align:start position:0% +this triangle +distribution however it simplifies our + + align:start position:0% +distribution however it simplifies our + + + align:start position:0% +distribution however it simplifies our +math greatly + + align:start position:0% +math greatly + + + align:start position:0% +math greatly +so we use this triangle distribution and + + align:start position:0% +so we use this triangle distribution and + + + align:start position:0% +so we use this triangle distribution and +try to extract some data from this + + align:start position:0% +try to extract some data from this + + + align:start position:0% +try to extract some data from this +the second thing that we can see from + + align:start position:0% +the second thing that we can see from + + + align:start position:0% +the second thing that we can see from +this is that this distribution is + + align:start position:0% +this is that this distribution is + + + align:start position:0% +this is that this distribution is +actually a bit off-center + + align:start position:0% +actually a bit off-center + + + align:start position:0% +actually a bit off-center +at theta equals to negative two now + + align:start position:0% +at theta equals to negative two now + + + align:start position:0% +at theta equals to negative two now +normally we would expect + + align:start position:0% +normally we would expect + + + align:start position:0% +normally we would expect +the highest count rate when our howitzer + + align:start position:0% +the highest count rate when our howitzer + + + align:start position:0% +the highest count rate when our howitzer +is pointed dead on + + align:start position:0% +is pointed dead on + + + align:start position:0% +is pointed dead on +at our detector at theta equals to zero + + align:start position:0% +at our detector at theta equals to zero + + + align:start position:0% +at our detector at theta equals to zero +this offset indicates that the + + align:start position:0% +this offset indicates that the + + + align:start position:0% +this offset indicates that the +protractor that we use to measure angles + + align:start position:0% +protractor that we use to measure angles + + + align:start position:0% +protractor that we use to measure angles +is actually a little bit off + + align:start position:0% +is actually a little bit off + + + align:start position:0% +is actually a little bit off +and pointing that on actually + + align:start position:0% +and pointing that on actually + + + align:start position:0% +and pointing that on actually +corresponds to theta equals to 2. + + align:start position:0% +corresponds to theta equals to 2. + + + align:start position:0% +corresponds to theta equals to 2. +finally this gives us our angular + + align:start position:0% +finally this gives us our angular + + + align:start position:0% +finally this gives us our angular +response function if we replace + + align:start position:0% +response function if we replace + + + align:start position:0% +response function if we replace +zero with our howitzer angle phi this + + align:start position:0% +zero with our howitzer angle phi this + + + align:start position:0% +zero with our howitzer angle phi this +gives us the spread around phi + + align:start position:0% +gives us the spread around phi + + + align:start position:0% +gives us the spread around phi +of scattering angles theta that we + + align:start position:0% +of scattering angles theta that we + + + align:start position:0% +of scattering angles theta that we +detect + + align:start position:0% +detect + + + align:start position:0% +detect +we accommodate this in our equations via + + align:start position:0% +we accommodate this in our equations via + + + align:start position:0% +we accommodate this in our equations via +a convolution + + align:start position:0% +a convolution + + + align:start position:0% +a convolution +now this can intuitively be thought as + + align:start position:0% +now this can intuitively be thought as + + + align:start position:0% +now this can intuitively be thought as +taking these two rates which are given + + align:start position:0% +taking these two rates which are given + + + align:start position:0% +taking these two rates which are given +thompson and rutherford the probability + + align:start position:0% +thompson and rutherford the probability + + + align:start position:0% +thompson and rutherford the probability +of having a scattering at angle theta + + align:start position:0% +of having a scattering at angle theta + + + align:start position:0% +of having a scattering at angle theta +we then multiply it by the probability + + align:start position:0% +we then multiply it by the probability + + + align:start position:0% +we then multiply it by the probability +of an scattering angle theta being + + align:start position:0% +of an scattering angle theta being + + + align:start position:0% +of an scattering angle theta being +detected + + align:start position:0% +detected + + + align:start position:0% +detected +by our how its are positioned at an + + align:start position:0% +by our how its are positioned at an + + + align:start position:0% +by our how its are positioned at an +angle phi and then we integrate over all + + align:start position:0% +angle phi and then we integrate over all + + + align:start position:0% +angle phi and then we integrate over all +theta + + align:start position:0% +theta + + + align:start position:0% +theta +this gives us two different counting + + align:start position:0% +this gives us two different counting + + + align:start position:0% +this gives us two different counting +rates as a function of our howitzer + + align:start position:0% +rates as a function of our howitzer + + + align:start position:0% +rates as a function of our howitzer +angle fee + + align:start position:0% +angle fee + + + align:start position:0% +angle fee +one for our rutherford theory and one + + align:start position:0% +one for our rutherford theory and one + + + align:start position:0% +one for our rutherford theory and one +for our thomson theory + + align:start position:0% +for our thomson theory + + + align:start position:0% +for our thomson theory +this gives us two equations that we can + + align:start position:0% +this gives us two equations that we can + + + align:start position:0% +this gives us two equations that we can +use to compare our data + + align:start position:0% +use to compare our data + + + align:start position:0% +use to compare our data +given geometric considerations about our + + align:start position:0% +given geometric considerations about our + + + align:start position:0% +given geometric considerations about our +apparatus + + align:start position:0% +apparatus + + + align:start position:0% +apparatus +so after that we are finally ready to go + + align:start position:0% +so after that we are finally ready to go + + + align:start position:0% +so after that we are finally ready to go +so we take our gold foil we put it back + + align:start position:0% +so we take our gold foil we put it back + + + align:start position:0% +so we take our gold foil we put it back +in + + align:start position:0% +in + + + align:start position:0% +in +we measure at different angles between + + align:start position:0% +we measure at different angles between + + + align:start position:0% +we measure at different angles between +fee equals to + + align:start position:0% +fee equals to + + + align:start position:0% +fee equals to +10 degrees and 60 degrees we let a + + align:start position:0% +10 degrees and 60 degrees we let a + + + align:start position:0% +10 degrees and 60 degrees we let a +detector + + align:start position:0% +detector + + + align:start position:0% +detector +detect for a while and over the period + + align:start position:0% +detect for a while and over the period + + + align:start position:0% +detect for a while and over the period +of time + + align:start position:0% +of time + + + align:start position:0% +of time +at any one of our measuring rates we get + + align:start position:0% +at any one of our measuring rates we get + + + align:start position:0% +at any one of our measuring rates we get +something that looks a bit like + + align:start position:0% +something that looks a bit like + + + align:start position:0% +something that looks a bit like +this now this mca bin number down here + + align:start position:0% +this now this mca bin number down here + + + align:start position:0% +this now this mca bin number down here +corresponds to the energy + + align:start position:0% +corresponds to the energy + + + align:start position:0% +corresponds to the energy +of the particles that we're detecting + + align:start position:0% +of the particles that we're detecting + + + align:start position:0% +of the particles that we're detecting +and on the y-axis here is our count rate + + align:start position:0% +and on the y-axis here is our count rate + + + align:start position:0% +and on the y-axis here is our count rate +now the first thing that you might think + + align:start position:0% +now the first thing that you might think + + + align:start position:0% +now the first thing that you might think +and the first thing that we thought as + + align:start position:0% +and the first thing that we thought as + + + align:start position:0% +and the first thing that we thought as +well is well + + align:start position:0% +well is well + + + align:start position:0% +well is well +this is about a gaussian right here + + align:start position:0% +this is about a gaussian right here + + + align:start position:0% +this is about a gaussian right here +that's our particle and everything below + + align:start position:0% +that's our particle and everything below + + + align:start position:0% +that's our particle and everything below +that is just noise + + align:start position:0% +that is just noise + + + align:start position:0% +that is just noise +however as we found out the energy loss + + align:start position:0% +however as we found out the energy loss + + + align:start position:0% +however as we found out the energy loss +through + + align:start position:0% +through + + + align:start position:0% +through +a material is actually described by a + + align:start position:0% +a material is actually described by a + + + align:start position:0% +a material is actually described by a +landau distribution + + align:start position:0% +landau distribution + + + align:start position:0% +landau distribution +which is a gaussian but with a slightly + + align:start position:0% +which is a gaussian but with a slightly + + + align:start position:0% +which is a gaussian but with a slightly +longer tail on one side + + align:start position:0% +longer tail on one side + + + align:start position:0% +longer tail on one side +what you see here is a gaussian with a + + align:start position:0% +what you see here is a gaussian with a + + + align:start position:0% +what you see here is a gaussian with a +slightly longer tail on one side + + align:start position:0% +slightly longer tail on one side + + + align:start position:0% +slightly longer tail on one side +so by fitting this to a landau distrib + + align:start position:0% +so by fitting this to a landau distrib + + + align:start position:0% +so by fitting this to a landau distrib +we fit this to a land out distribution + + align:start position:0% +we fit this to a land out distribution + + + align:start position:0% +we fit this to a land out distribution +and get chi + + align:start position:0% +and get chi + + + align:start position:0% +and get chi +squareds between 0.5 and 2 which + + align:start position:0% +squareds between 0.5 and 2 which + + + align:start position:0% +squareds between 0.5 and 2 which +indicates + + align:start position:0% +indicates + + + align:start position:0% +indicates +which suggests that all this did + + align:start position:0% +which suggests that all this did + + + align:start position:0% +which suggests that all this did +actually come from a land our + + align:start position:0% +actually come from a land our + + + align:start position:0% +actually come from a land our +distribution + + align:start position:0% +distribution + + + align:start position:0% +distribution +and all of these are valid scattering + + align:start position:0% +and all of these are valid scattering + + + align:start position:0% +and all of these are valid scattering +data points and not just + + align:start position:0% +data points and not just + + + align:start position:0% +data points and not just +noise we further confirmed this by + + align:start position:0% +noise we further confirmed this by + + + align:start position:0% +noise we further confirmed this by +measuring our noise by taking our + + align:start position:0% +measuring our noise by taking our + + + align:start position:0% +measuring our noise by taking our +howitzer pointed + + align:start position:0% +howitzer pointed + + + align:start position:0% +howitzer pointed +away from our detector and just letting + + align:start position:0% +away from our detector and just letting + + + align:start position:0% +away from our detector and just letting +our detector collect + + align:start position:0% +our detector collect + + + align:start position:0% +our detector collect +we ultimately determined that the noise + + align:start position:0% +we ultimately determined that the noise + + + align:start position:0% +we ultimately determined that the noise +within our energy range of interest + + align:start position:0% +within our energy range of interest + + + align:start position:0% +within our energy range of interest +is very small much smaller than any + + align:start position:0% +is very small much smaller than any + + + align:start position:0% +is very small much smaller than any +count rate that we + + align:start position:0% +count rate that we + + + align:start position:0% +count rate that we +care about in our experiment therefore + + align:start position:0% +care about in our experiment therefore + + + align:start position:0% +care about in our experiment therefore +because of this + + align:start position:0% +because of this + + + align:start position:0% +because of this +and the fact that our energy our + + align:start position:0% +and the fact that our energy our + + + align:start position:0% +and the fact that our energy our +distribution models land our + + align:start position:0% +distribution models land our + + + align:start position:0% +distribution models land our +distribution which is what we expect + + align:start position:0% +distribution which is what we expect + + + align:start position:0% +distribution which is what we expect +we conclude that we can use all the + + align:start position:0% +we conclude that we can use all the + + + align:start position:0% +we conclude that we can use all the +points that we detect + + align:start position:0% +points that we detect + + + align:start position:0% +points that we detect +as valid scattering data points but of + + align:start position:0% +as valid scattering data points but of + + + align:start position:0% +as valid scattering data points but of +course it comes with some good old + + align:start position:0% +course it comes with some good old + + + align:start position:0% +course it comes with some good old +counting uncertainty in addition we have + + align:start position:0% +counting uncertainty in addition we have + + + align:start position:0% +counting uncertainty in addition we have +some uncertainty + + align:start position:0% +some uncertainty + + + align:start position:0% +some uncertainty +in our angles we read the angles of our + + align:start position:0% +in our angles we read the angles of our + + + align:start position:0% +in our angles we read the angles of our +howitzer + + align:start position:0% +howitzer + + + align:start position:0% +howitzer +by eye from a little protractor that we + + align:start position:0% +by eye from a little protractor that we + + + align:start position:0% +by eye from a little protractor that we +have in our apparatus + + align:start position:0% +have in our apparatus + + + align:start position:0% +have in our apparatus +but our eyes aren't so good so we tack a + + align:start position:0% +but our eyes aren't so good so we tack a + + + align:start position:0% +but our eyes aren't so good so we tack a +plus or minus wonder uncertainty to + + align:start position:0% +plus or minus wonder uncertainty to + + + align:start position:0% +plus or minus wonder uncertainty to +angular measurements + + align:start position:0% +angular measurements + + + align:start position:0% +angular measurements +my lab partner thinks .5 i think one + + align:start position:0% +my lab partner thinks .5 i think one + + + align:start position:0% +my lab partner thinks .5 i think one +because i'm not a certain + + align:start position:0% +because i'm not a certain + + + align:start position:0% +because i'm not a certain +so we take all these measurements we + + align:start position:0% +so we take all these measurements we + + + align:start position:0% +so we take all these measurements we +divide by the amount of time that we + + align:start position:0% +divide by the amount of time that we + + + align:start position:0% +divide by the amount of time that we +collected to get a count rate + + align:start position:0% +collected to get a count rate + + + align:start position:0% +collected to get a count rate +we graph this as a function of our angle + + align:start position:0% +we graph this as a function of our angle + + + align:start position:0% +we graph this as a function of our angle +that we measured it at + + align:start position:0% +that we measured it at + + + align:start position:0% +that we measured it at +and fit this to a rutherford and + + align:start position:0% +and fit this to a rutherford and + + + align:start position:0% +and fit this to a rutherford and +thompson convolved fit + + align:start position:0% +thompson convolved fit + + + align:start position:0% +thompson convolved fit +and we see something like this + + align:start position:0% +and we see something like this + + + align:start position:0% +and we see something like this +and i i think this really speaks for + + align:start position:0% +and i i think this really speaks for + + + align:start position:0% +and i i think this really speaks for +itself this is + + align:start position:0% +itself this is + + + align:start position:0% +itself this is +this is not an error in my code this + + align:start position:0% +this is not an error in my code this + + + align:start position:0% +this is not an error in my code this +thompson is really just + + align:start position:0% +thompson is really just + + + align:start position:0% +thompson is really just +that bad in accounting for our data but + + align:start position:0% +that bad in accounting for our data but + + + align:start position:0% +that bad in accounting for our data but +we see here that the rutherford + + align:start position:0% +we see here that the rutherford + + + align:start position:0% +we see here that the rutherford +scattering + + align:start position:0% +scattering + + + align:start position:0% +scattering +prediction more accurately describes the + + align:start position:0% +prediction more accurately describes the + + + align:start position:0% +prediction more accurately describes the +gradual fall off + + align:start position:0% +gradual fall off + + + align:start position:0% +gradual fall off +of our scattering rates as the howitzer + + align:start position:0% +of our scattering rates as the howitzer + + + align:start position:0% +of our scattering rates as the howitzer +angle gets bigger as opposed to the + + align:start position:0% +angle gets bigger as opposed to the + + + align:start position:0% +angle gets bigger as opposed to the +thompson fit + + align:start position:0% +thompson fit + + + align:start position:0% +thompson fit +with a chi squared of two thousand + + align:start position:0% +with a chi squared of two thousand + + + align:start position:0% +with a chi squared of two thousand +uh now there are different ways of + + align:start position:0% +uh now there are different ways of + + + align:start position:0% +uh now there are different ways of +potentially giving thompson a better + + align:start position:0% +potentially giving thompson a better + + + align:start position:0% +potentially giving thompson a better +shot + + align:start position:0% +shot + + + align:start position:0% +shot +accommodating for it maybe giving it a + + align:start position:0% +accommodating for it maybe giving it a + + + align:start position:0% +accommodating for it maybe giving it a +better chance of describing our data + + align:start position:0% +better chance of describing our data + + + align:start position:0% +better chance of describing our data +and i can go into this in more detail + + align:start position:0% +and i can go into this in more detail + + + align:start position:0% +and i can go into this in more detail +later if people are interested + + align:start position:0% +later if people are interested + + + align:start position:0% +later if people are interested +but ultimately we see that thompson is + + align:start position:0% +but ultimately we see that thompson is + + + align:start position:0% +but ultimately we see that thompson is +fundamentally + + align:start position:0% +fundamentally + + + align:start position:0% +fundamentally +unable to account for this data whereas + + align:start position:0% +unable to account for this data whereas + + + align:start position:0% +unable to account for this data whereas +rutherford describes it quite well + + align:start position:0% +rutherford describes it quite well + + + align:start position:0% +rutherford describes it quite well +now there's an additional caveat to this + + align:start position:0% +now there's an additional caveat to this + + + align:start position:0% +now there's an additional caveat to this +chi squared that we have here + + align:start position:0% +chi squared that we have here + + + align:start position:0% +chi squared that we have here +so this chi squared comes from fitting + + align:start position:0% +so this chi squared comes from fitting + + + align:start position:0% +so this chi squared comes from fitting +from + + align:start position:0% +from + + + align:start position:0% +from +our our rutherford and thompson data + + align:start position:0% +our our rutherford and thompson data + + + align:start position:0% +our our rutherford and thompson data +convolved with our beam profile however + + align:start position:0% +convolved with our beam profile however + + + align:start position:0% +convolved with our beam profile however +our beam profile + + align:start position:0% +our beam profile + + + align:start position:0% +our beam profile +does have some uncertainty associated in + + align:start position:0% +does have some uncertainty associated in + + + align:start position:0% +does have some uncertainty associated in +that fit that we had + + align:start position:0% +that fit that we had + + + align:start position:0% +that fit that we had +there is some uncertainty in the + + align:start position:0% +there is some uncertainty in the + + + align:start position:0% +there is some uncertainty in the +triangle so to sort of estimate how this + + align:start position:0% +triangle so to sort of estimate how this + + + align:start position:0% +triangle so to sort of estimate how this +uncertainty affects our data + + align:start position:0% +uncertainty affects our data + + + align:start position:0% +uncertainty affects our data +we vary our beam profile within one + + align:start position:0% +we vary our beam profile within one + + + align:start position:0% +we vary our beam profile within one +standard deviation + + align:start position:0% +standard deviation + + + align:start position:0% +standard deviation +of its fit parameters and see how our + + align:start position:0% +of its fit parameters and see how our + + + align:start position:0% +of its fit parameters and see how our +goodness of fit changes + + align:start position:0% +goodness of fit changes + + + align:start position:0% +goodness of fit changes +and we see here that the goodness of fit + + align:start position:0% +and we see here that the goodness of fit + + + align:start position:0% +and we see here that the goodness of fit +for our rutherford model + + align:start position:0% +for our rutherford model + + + align:start position:0% +for our rutherford model +well it varies somewhat depending on the + + align:start position:0% +well it varies somewhat depending on the + + + align:start position:0% +well it varies somewhat depending on the +convolution that we + + align:start position:0% +convolution that we + + + align:start position:0% +convolution that we +use it doesn't it doesn't change a + + align:start position:0% +use it doesn't it doesn't change a + + + align:start position:0% +use it doesn't it doesn't change a +significant amount + + align:start position:0% +significant amount + + + align:start position:0% +significant amount +and it certainly doesn't change enough + + align:start position:0% +and it certainly doesn't change enough + + + align:start position:0% +and it certainly doesn't change enough +to warrant considering the thompson + + align:start position:0% +to warrant considering the thompson + + + align:start position:0% +to warrant considering the thompson +model + + align:start position:0% +model + + + align:start position:0% +model +the discrepancy between the chi squareds + + align:start position:0% +the discrepancy between the chi squareds + + + align:start position:0% +the discrepancy between the chi squareds +and sort of the visual discrepancy you + + align:start position:0% +and sort of the visual discrepancy you + + + align:start position:0% +and sort of the visual discrepancy you +see here + + align:start position:0% +see here + + + align:start position:0% +see here +very clearly suggests that rutherford + + align:start position:0% +very clearly suggests that rutherford + + + align:start position:0% +very clearly suggests that rutherford +does a much better job + + align:start position:0% +does a much better job + + + align:start position:0% +does a much better job +of predicting our data than thomson + + align:start position:0% +of predicting our data than thomson + + + align:start position:0% +of predicting our data than thomson +which again suggests a more rutherford + + align:start position:0% +which again suggests a more rutherford + + + align:start position:0% +which again suggests a more rutherford +makeup of the atom as opposed to the + + align:start position:0% +makeup of the atom as opposed to the + + + align:start position:0% +makeup of the atom as opposed to the +thomson plum pudding model + + align:start position:0% +thomson plum pudding model + + + align:start position:0% +thomson plum pudding model +so in conclusion thompson's plum pudding + + align:start position:0% +so in conclusion thompson's plum pudding + + + align:start position:0% +so in conclusion thompson's plum pudding +model is found to fundamentally be + + align:start position:0% +model is found to fundamentally be + + + align:start position:0% +model is found to fundamentally be +unable to describe the scattering rates + + align:start position:0% +unable to describe the scattering rates + + + align:start position:0% +unable to describe the scattering rates +that we observe at large angles + + align:start position:0% +that we observe at large angles + + + align:start position:0% +that we observe at large angles +the rutherford model more accurately + + align:start position:0% +the rutherford model more accurately + + + align:start position:0% +the rutherford model more accurately +predicts this gradual falloff + + align:start position:0% +predicts this gradual falloff + + + align:start position:0% +predicts this gradual falloff +which suggests a more rough more + + align:start position:0% +which suggests a more rough more + + + align:start position:0% +which suggests a more rough more +rutherford rutherford-like + + align:start position:0% +rutherford rutherford-like + + + align:start position:0% +rutherford rutherford-like +view of our atom and that's it thank you + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +all for right + + align:start position:0% + + + + align:start position:0% + +yeah um did you try the fit without + + align:start position:0% +yeah um did you try the fit without + + + align:start position:0% +yeah um did you try the fit without +using the + + align:start position:0% +using the + + + align:start position:0% +using the +triangular correction yes i did and + + align:start position:0% +triangular correction yes i did and + + + align:start position:0% +triangular correction yes i did and +this is another interesting point which + + align:start position:0% +this is another interesting point which + + + align:start position:0% +this is another interesting point which +shows + + align:start position:0% +shows + + + align:start position:0% +shows +that our convolution does benefit our + + align:start position:0% +that our convolution does benefit our + + + align:start position:0% +that our convolution does benefit our +data it does a much better + + align:start position:0% +data it does a much better + + + align:start position:0% +data it does a much better +not not much better not as bad as + + align:start position:0% +not not much better not as bad as + + + align:start position:0% +not not much better not as bad as +thompson relatively speaking but it does + + align:start position:0% +thompson relatively speaking but it does + + + align:start position:0% +thompson relatively speaking but it does +a noticeably better job at describing + + align:start position:0% +a noticeably better job at describing + + + align:start position:0% +a noticeably better job at describing +our data than + + align:start position:0% +our data than + + + align:start position:0% +our data than +the pure rutherford scattering one over + + align:start position:0% +the pure rutherford scattering one over + + + align:start position:0% +the pure rutherford scattering one over +signed to the fourth + + align:start position:0% +signed to the fourth + + + align:start position:0% +signed to the fourth +fit so the difference + + align:start position:0% + + + + align:start position:0% + +and sorry 8.18 is is yeah + + align:start position:0% +and sorry 8.18 is is yeah + + + align:start position:0% +and sorry 8.18 is is yeah +the that's a chi-squared of eight for + + align:start position:0% +the that's a chi-squared of eight for + + + align:start position:0% +the that's a chi-squared of eight for +just fitting with the raw rutherford + + align:start position:0% +just fitting with the raw rutherford + + + align:start position:0% +just fitting with the raw rutherford +scattering without the convolution + + align:start position:0% + + + + align:start position:0% + +yes um do you have any spots that show + + align:start position:0% +yes um do you have any spots that show + + + align:start position:0% +yes um do you have any spots that show +your + + align:start position:0% +your + + + align:start position:0% +your +distribution i i thought i did you saw + + align:start position:0% +distribution i i thought i did you saw + + + align:start position:0% +distribution i i thought i did you saw +me switch forward and then realize that + + align:start position:0% +me switch forward and then realize that + + + align:start position:0% +me switch forward and then realize that +it wasn't there so i switched back no uh + + align:start position:0% +it wasn't there so i switched back no uh + + + align:start position:0% +it wasn't there so i switched back no uh +so i don't have a picture of the land + + align:start position:0% +so i don't have a picture of the land + + + align:start position:0% +so i don't have a picture of the land +outfit + + align:start position:0% +outfit + + + align:start position:0% +outfit +one thing that i can describe which is + + align:start position:0% +one thing that i can describe which is + + + align:start position:0% +one thing that i can describe which is +um a small caveat to this + + align:start position:0% +um a small caveat to this + + + align:start position:0% +um a small caveat to this +is that the landau distribution + + align:start position:0% +is that the landau distribution + + + align:start position:0% +is that the landau distribution +describes energy loss + + align:start position:0% +describes energy loss + + + align:start position:0% +describes energy loss +this is usually a gaussian with one tail + + align:start position:0% +this is usually a gaussian with one tail + + + align:start position:0% +this is usually a gaussian with one tail +on + + align:start position:0% +on + + + align:start position:0% +on +this isn't too well it's a gaussian with + + align:start position:0% +this isn't too well it's a gaussian with + + + align:start position:0% +this isn't too well it's a gaussian with +a slightly longer tail on the right hand + + align:start position:0% +a slightly longer tail on the right hand + + + align:start position:0% +a slightly longer tail on the right hand +side + + align:start position:0% +side + + + align:start position:0% +side +now this is a gaussian with a slightly + + align:start position:0% +now this is a gaussian with a slightly + + + align:start position:0% +now this is a gaussian with a slightly +longer tail on the left hand side + + align:start position:0% +longer tail on the left hand side + + + align:start position:0% +longer tail on the left hand side +however + + align:start position:0% +however + + + align:start position:0% +however +what we see here is energy and energy + + align:start position:0% +what we see here is energy and energy + + + align:start position:0% +what we see here is energy and energy +loss is sort of the inverse of this + + align:start position:0% +loss is sort of the inverse of this + + + align:start position:0% +loss is sort of the inverse of this +so we actually fit this to a reverse + + align:start position:0% +so we actually fit this to a reverse + + + align:start position:0% +so we actually fit this to a reverse +landau distribution and + + align:start position:0% +landau distribution and + + + align:start position:0% +landau distribution and +throughout all our data we get chi + + align:start position:0% +throughout all our data we get chi + + + align:start position:0% +throughout all our data we get chi +squareds between or reduce type reduce + + align:start position:0% +squareds between or reduce type reduce + + + align:start position:0% +squareds between or reduce type reduce +chi squareds between 0.5 + + align:start position:0% +chi squareds between 0.5 + + + align:start position:0% +chi squareds between 0.5 +and 2 which indicates good fit + + align:start position:0% + + + + align:start position:0% + +uh 60 degrees 60 degrees we collected + + align:start position:0% +uh 60 degrees 60 degrees we collected + + + align:start position:0% +uh 60 degrees 60 degrees we collected +over the course of five days + + align:start position:0% +over the course of five days + + + align:start position:0% +over the course of five days +and i don't think we could have actually + + align:start position:0% +and i don't think we could have actually + + + align:start position:0% +and i don't think we could have actually +collected data at much higher + + align:start position:0% +collected data at much higher + + + align:start position:0% +collected data at much higher +angles than that because our noise data + + align:start position:0% +angles than that because our noise data + + + align:start position:0% +angles than that because our noise data +our noise rate right here + + align:start position:0% +our noise rate right here + + + align:start position:0% +our noise rate right here +is 0.002 now this is still a bit + + align:start position:0% +is 0.002 now this is still a bit + + + align:start position:0% +is 0.002 now this is still a bit +smaller than our counting rate for 60 + + align:start position:0% +smaller than our counting rate for 60 + + + align:start position:0% +smaller than our counting rate for 60 +degrees + + align:start position:0% +degrees + + + align:start position:0% +degrees +but if we started to go further we would + + align:start position:0% +but if we started to go further we would + + + align:start position:0% +but if we started to go further we would +start to enter the regime where noise + + align:start position:0% +start to enter the regime where noise + + + align:start position:0% +start to enter the regime where noise +becomes + + align:start position:0% +becomes + + + align:start position:0% +becomes +much more + + align:start position:0% + + + + align:start position:0% + +that dominant five days or five days off + + align:start position:0% +that dominant five days or five days off + + + align:start position:0% +that dominant five days or five days off +the top of my head i believe + + align:start position:0% +the top of my head i believe + + + align:start position:0% +the top of my head i believe +400. you can actually see i know the + + align:start position:0% +400. you can actually see i know the + + + align:start position:0% +400. you can actually see i know the +rate here which you can very easily go + + align:start position:0% +rate here which you can very easily go + + + align:start position:0% +rate here which you can very easily go +backwards + + align:start position:0% +backwards + + + align:start position:0% +backwards +in the math oh i guess this is somewhere + + align:start position:0% +in the math oh i guess this is somewhere + + + align:start position:0% +in the math oh i guess this is somewhere +down here + + align:start position:0% +down here + + + align:start position:0% +down here +100 per day yeah something like that + + align:start position:0% +100 per day yeah something like that + + + align:start position:0% +100 per day yeah something like that +yes something like that yep + + align:start position:0% +yes something like that yep + + + align:start position:0% +yes something like that yep +and our the noise that we mentioned here + + align:start position:0% +and our the noise that we mentioned here + + + align:start position:0% +and our the noise that we mentioned here +is actually restricted to our energy of + + align:start position:0% +is actually restricted to our energy of + + + align:start position:0% +is actually restricted to our energy of +interest so + + align:start position:0% +interest so + + + align:start position:0% +interest so +there's a fair bit of noise at much + + align:start position:0% +there's a fair bit of noise at much + + + align:start position:0% +there's a fair bit of noise at much +lower energy levels specifically between + + align:start position:0% +lower energy levels specifically between + + + align:start position:0% +lower energy levels specifically between +this mca bin number of 0 and 50 down + + align:start position:0% +this mca bin number of 0 and 50 down + + + align:start position:0% +this mca bin number of 0 and 50 down +here + + align:start position:0% +here + + + align:start position:0% +here +there's a fair bit of noise there but + + align:start position:0% +there's a fair bit of noise there but + + + align:start position:0% +there's a fair bit of noise there but +once you start getting up to this larger + + align:start position:0% +once you start getting up to this larger + + + align:start position:0% +once you start getting up to this larger +area right here between + + align:start position:0% +area right here between + + + align:start position:0% +area right here between +50 and 1500 we start to see much less + + align:start position:0% +50 and 1500 we start to see much less + + + align:start position:0% +50 and 1500 we start to see much less +noise + + align:start position:0% + + + + align:start position:0% + +all right let's thank henry again \ No newline at end of file diff --git a/5QKJG0FZTio.txt b/5QKJG0FZTio.txt new file mode 100644 index 0000000000000000000000000000000000000000..8a7dabd4af5cf61580f33c4bb8f291df1a26115a --- /dev/null +++ b/5QKJG0FZTio.txt @@ -0,0 +1,115 @@ +align:start position:0% + +we want to relate the small length area + + align:start position:0% +we want to relate the small length area + + + align:start position:0% +we want to relate the small length area +or volume element to Delta M the amount + + align:start position:0% +or volume element to Delta M the amount + + + align:start position:0% +or volume element to Delta M the amount +of mass contained + + align:start position:0% +of mass contained + + + align:start position:0% +of mass contained +within in one dimension this relation is + + align:start position:0% +within in one dimension this relation is + + + align:start position:0% +within in one dimension this relation is +called the linear density Lambda which + + align:start position:0% +called the linear density Lambda which + + + align:start position:0% +called the linear density Lambda which +is Delta M over Delta + + align:start position:0% +is Delta M over Delta + + + align:start position:0% +is Delta M over Delta +L for a uniform Rod of length L and + + align:start position:0% +L for a uniform Rod of length L and + + + align:start position:0% +L for a uniform Rod of length L and +total mass m Lambda is equal to m + + align:start position:0% +total mass m Lambda is equal to m + + + align:start position:0% +total mass m Lambda is equal to m +l in two Dimensions the area element + + align:start position:0% +l in two Dimensions the area element + + + align:start position:0% +l in two Dimensions the area element +contains an amount of mass Sigma * Delta + + align:start position:0% +contains an amount of mass Sigma * Delta + + + align:start position:0% +contains an amount of mass Sigma * Delta +a where Sigma has units of mass over + + align:start position:0% +a where Sigma has units of mass over + + + align:start position:0% +a where Sigma has units of mass over +area finally in three dimensions the + + align:start position:0% +area finally in three dimensions the + + + align:start position:0% +area finally in three dimensions the +volume density row connects the small + + align:start position:0% +volume density row connects the small + + + align:start position:0% +volume density row connects the small +Mass Delta m to the volume Delta + + align:start position:0% + + + + align:start position:0% + +V \ No newline at end of file diff --git a/69H3kTwques.txt b/69H3kTwques.txt new file mode 100644 index 0000000000000000000000000000000000000000..745f99bf3425708ec69261f7b0415c8355e63419 --- /dev/null +++ b/69H3kTwques.txt @@ -0,0 +1,411 @@ +[MUSIC PLAYING] + +PROFESSOR: Hello, everyone. + +Today we'll be taking a +look at how light interacts + +with the surface +of a solar cell. + +Right now I'm standing next +to a solar module made up + +of individual +silicon solar cells. + +If you look closely, these +cells actually appear black. + +And they appear black for +a very important reason. + +Solar engineers work very hard +to make their solar cells as + +efficient as possible. + +Reflected light is lost +energy, so good engineers + +will want to minimize the total +amount of reflected light. + +To make solar cells absorb +as much light as possible, + +and appear black, solar +engineers do two things. + +First, they grow +this very thin film + +of a dielectric +layer on the surface. + +This layer is aptly called +an anti-reflection coating. + +Second, they texture the wafer. + +And today we'll demonstrate +how texturing is performed, + +and quantify its enhancement +for reducing light reflection. + +Silicon wafers don't +start out black. + +In fact, they appear gray. + +Polished wafers even +look mirror-like, + +and reflect quite +a bit of light. + +Here we see a polished wafer, +which reflects around 1/3 + +of the light off its surface. + +And to create the rough surface +that reflects less light, + +solar engineers immerse +their silicon wafers + +into a hot, wet +chemical bath, which + +helps create tiny +surface features. + +In this example, +we use a solution + +of potassium hydroxide, +or KOH, which + +is heated to around +80 degrees Celsius. + +This violent +reaction is actually + +etching into the +silicon, and carving out + +little tiny pyramids +on the surface. + +And the result is a wafer that +loses its shiny appearance, + +and appears to +have a dull finish. + +The textured wafer is +left with a surface that + +is covered with microscopic +pyramids, whose base + +is around a micron, +or about 1/50 + +of the width of a human hair. + +It turns out that this wafer +only reflects about 1/3 + +as much light as +it previously did. + +The reason this KOH which +bath work so well at texturing + +the silicon surface +is due to the fact + +that these silicon wafers +are large crystals, which + +in this case means that the +atoms are formed in an ordered, + +repeating pattern. + +I have a model of the silicon +crystal structure right here. + +On our model, I've highlighted +the surface in red. + +Note that each silicon +atom below the surface + +is actually bonded to +four other silicon atoms, + +with four covalent bonds. + +Note that the surface +atoms are only + +bonded to two other +silicon atoms, + +and it has two bonds +that are unbonded. + +The alkaline etch is able +to remove silicon atoms more + +rapidly, when they have fewer +bonds holding to the lattice. + +Hence, a solution quickly +removes atoms on the surface. + +Now if I were acting +as the KOH solution, + +I would remove +all the atoms that + +only have two covalent bonds. + +Let's remove a few atoms. + +So this one only has +two covalent bonds. + +It gets removed. + +These three atoms +on the surface only + +have two covalent +bonds holding them, + +so I'll remove them as well. + +Let's go ahead. + +Now we can see that after +we have removed a few atoms, + +we have created some atoms below +our original surface that only + +have two covalent bonds +holding to the lattice. + +These atoms will also +get removed by the KOH. + +Now if we continue +this process, it + +would look something like this. + +So what we're going to do +is measure the reflectivity + +of both a flat and +a textured wafer. + +First, we'll measure +the flat wafer, + +and use a laser pointer +as a light source + +to simulate sunlight coming +from very far away point. + +We'll shine light +down on the surface, + +and measure the +amount of light that + +gets reflected or +bounced back away + +from the surface, +which we'll label as R. + +So I'm standing next to our +first experiment, which I just + +outlined in the previous sketch. + +We'll be using +this laser pointer, + +shining it onto this silicon +wafer, and into our photodiode. + +For those of you who don't +know what a photodiode is, + +it is a tool that can +measure the amount of light + +hitting its surface. + +The current that's read +off of this ammeter + +will be proportional +to the amount of light + +hitting our photodiode. + +To help visualize the beam path, +we're going to use some steam. + +Now if we turn on our laser +pointer, hits our photodiode, + +and we can get a good reading. + +And right now we see that it's +reading around 0.9 milliamps. + +But how does this compare +to a textured wafer? + +Let's find out. + +Now it's hard to +measure the reflectivity + +of a textured wafer +with a laser pointer, + +because it bounces the light +off at several different angles, + +and we can't measure the entire +beam with a photodiode alone. + +However, we can simulate +what this would be like. + +Let's go to our +sketch board to show + +how we can approximate +this measurement. + +To measure the reflectivity +of a textured surface, + +we'll create a 10,000 +to one scale model. + +We'll approximate +our textured surface + +using two pieces of silicon. + +Again, we use a laser +pointer as our light source, + +and shine it on one +side of the pyramid. + +It'll bounce off that +next surface, and off + +the adjacent side, +and then we'll + +measure the amount +of light reflected. + +Let's go to our +experimental setup. + +So let's clarify our set up. + +The two angled lines in our +drawing, the adjacent sides, + +on our atomic models, and the +two angled, non-textured wafers + +in our set up, are all +representing the pyramid + +structure of a +textured wafer, just + +like the one visible in our +scanning electron microscope + +image. + +Let's use some steam to +visualize the beam path. + +Now that the steam +has settled, we + +can get an accurate +reading of the reflectivity + +of our modeled silicon surface. + +And I turn on our laser pointer. + +So now we can see +that our photodiode + +is reading around +0.33 milliamps. + +This corresponds to +around a 9% reflectivity, + +which is quite a huge +reduction from what + +we had before, by +about a factor of 3. + +So in summary, +today we learned how + +silicon is etched +using a KOH solution, + +and how the resultant +pyramids increase + +the efficiency of +our solar cells, + +by reducing the amount +of reflective losses + +by a factor of 3. + +If you found this +interesting, please + +watch our other solar +demos to learn more about + +how these exciting devices work. + +I'm Joe Sullivan from MIT, +and thanks for watching. + +I'm out of here. + +[MUSIC PLAYING] \ No newline at end of file diff --git a/8IeL2koaHMk.txt b/8IeL2koaHMk.txt new file mode 100644 index 0000000000000000000000000000000000000000..be4ce17e2936f68614bc649bf49e11519045d0a9 --- /dev/null +++ b/8IeL2koaHMk.txt @@ -0,0 +1,6842 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu did anybody have any + + align:start position:0% +ocw.mit.edu did anybody have any + + + align:start position:0% +ocw.mit.edu did anybody have any +questions about this PA path analysis + + align:start position:0% +questions about this PA path analysis + + + align:start position:0% +questions about this PA path analysis +which is where we ended the class last + + align:start position:0% +which is where we ended the class last + + + align:start position:0% +which is where we ended the class last +time it's a way to + + align:start position:0% + + + + align:start position:0% + +find the probability that for two + + align:start position:0% +find the probability that for two + + + align:start position:0% +find the probability that for two +individuals when you know they're too + + align:start position:0% +individuals when you know they're too + + + align:start position:0% +individuals when you know they're too +related in related in some way but if + + align:start position:0% +related in related in some way but if + + + align:start position:0% +related in related in some way but if +you have + + align:start position:0% +you have + + + align:start position:0% +you have +their uh you + + align:start position:0% +their uh you + + + align:start position:0% +their uh you +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +can draw the family tree you're able to + + align:start position:0% +can draw the family tree you're able to + + + align:start position:0% +can draw the family tree you're able to +then using path + + align:start position:0% +then using path + + + align:start position:0% +then using path +analysis you + + align:start position:0% +analysis you + + + align:start position:0% +analysis you +can find the probability that the two El + + align:start position:0% +can find the probability that the two El + + + align:start position:0% +can find the probability that the two El +deals at one Locus are identical or how + + align:start position:0% +deals at one Locus are identical or how + + + align:start position:0% +deals at one Locus are identical or how +many of them are going to be + + align:start position:0% + + + + align:start position:0% + +identical it's called the inbreeding + + align:start position:0% +identical it's called the inbreeding + + + align:start position:0% +identical it's called the inbreeding +coefficient or the coefficient of + + align:start position:0% +coefficient or the coefficient of + + + align:start position:0% +coefficient or the coefficient of +kinship uh both terms are + + align:start position:0% +kinship uh both terms are + + + align:start position:0% +kinship uh both terms are +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +used but you can use the same thing to + + align:start position:0% +used but you can use the same thing to + + + align:start position:0% +used but you can use the same thing to +compute + + align:start position:0% +compute + + + align:start position:0% +compute +this how many genes do you get from your + + align:start position:0% +this how many genes do you get from your + + + align:start position:0% +this how many genes do you get from your +great-grandparent for example + + align:start position:0% + + + + align:start position:0% + +all + + align:start position:0% + + + + align:start position:0% + +right so this is the only slide from the + + align:start position:0% +right so this is the only slide from the + + + align:start position:0% +right so this is the only slide from the +previous uh the first class I didn't get + + align:start position:0% +previous uh the first class I didn't get + + + align:start position:0% +previous uh the first class I didn't get +to we were talking about Wilson's notes + + align:start position:0% +to we were talking about Wilson's notes + + + align:start position:0% +to we were talking about Wilson's notes +from EO Wilson's + + align:start position:0% +from EO Wilson's + + + align:start position:0% +from EO Wilson's +book we got these I read The Abridged + + align:start position:0% +book we got these I read The Abridged + + + align:start position:0% +book we got these I read The Abridged +Edition uh for making those notes + + align:start position:0% +Edition uh for making those notes + + + align:start position:0% +Edition uh for making those notes +but he talks about about the possibility + + align:start position:0% +but he talks about about the possibility + + + align:start position:0% +but he talks about about the possibility +of inbreeding taboos but when he + + align:start position:0% +of inbreeding taboos but when he + + + align:start position:0% +of inbreeding taboos but when he +introduces it he uses some more terms + + align:start position:0% +introduces it he uses some more terms + + + align:start position:0% +introduces it he uses some more terms +that are interesting he he talks + + align:start position:0% +that are interesting he he talks + + + align:start position:0% +that are interesting he he talks +introduces by defining the effective + + align:start position:0% +introduces by defining the effective + + + align:start position:0% +introduces by defining the effective +population + + align:start position:0% +population + + + align:start position:0% +population +number and that I've defined it at the + + align:start position:0% +number and that I've defined it at the + + + align:start position:0% +number and that I've defined it at the +bottom + + align:start position:0% +bottom + + + align:start position:0% +bottom +there the number of individuals in an + + align:start position:0% +there the number of individuals in an + + + align:start position:0% +there the number of individuals in an +ideal randomly breeding population with + + align:start position:0% +ideal randomly breeding population with + + + align:start position:0% +ideal randomly breeding population with +one:1 sex + + align:start position:0% +one:1 sex + + + align:start position:0% +one:1 sex +ratio that would have the same rate of + + align:start position:0% +ratio that would have the same rate of + + + align:start position:0% +ratio that would have the same rate of +heterozygosity decrease as the total + + align:start position:0% +heterozygosity decrease as the total + + + align:start position:0% +heterozygosity decrease as the total +population under + + align:start position:0% +population under + + + align:start position:0% +population under +consideration + + align:start position:0% +consideration + + + align:start position:0% +consideration +so it that's what makes it the effective + + align:start position:0% +so it that's what makes it the effective + + + align:start position:0% +so it that's what makes it the effective +population + + align:start position:0% +population + + + align:start position:0% +population +uh it's usually the smallest number you + + align:start position:0% +uh it's usually the smallest number you + + + align:start position:0% +uh it's usually the smallest number you +can have and and not have much + + align:start position:0% + + + + align:start position:0% + +inbreeding at least you would not have + + align:start position:0% +inbreeding at least you would not have + + + align:start position:0% +inbreeding at least you would not have +any more inbreeding than you would if + + align:start position:0% +any more inbreeding than you would if + + + align:start position:0% +any more inbreeding than you would if +they were breed randomly in the whole + + align:start position:0% +they were breed randomly in the whole + + + align:start position:0% +they were breed randomly in the whole +the larger + + align:start position:0% + + + + align:start position:0% + +population and numbers aren't really big + + align:start position:0% +population and numbers aren't really big + + + align:start position:0% +population and numbers aren't really big +U they get as low as 10 in some animal + + align:start position:0% +U they get as low as 10 in some animal + + + align:start position:0% +U they get as low as 10 in some animal +some species but they often are more + + align:start position:0% +some species but they often are more + + + align:start position:0% +some species but they often are more +closer to + + align:start position:0% +closer to + + + align:start position:0% +closer to +100 um and then he talks about wri's + + align:start position:0% +100 um and then he talks about wri's + + + align:start position:0% +100 um and then he talks about wri's +Island model now what that + + align:start position:0% +Island model now what that + + + align:start position:0% +Island model now what that +is he he has a model of a population + + align:start position:0% +is he he has a model of a population + + + align:start position:0% +is he he has a model of a population +that's divided up into smaller + + align:start position:0% +that's divided up into smaller + + + align:start position:0% +that's divided up into smaller +groups and we know that it's probably at + + align:start position:0% +groups and we know that it's probably at + + + align:start position:0% +groups and we know that it's probably at +least very roughly many populations are + + align:start position:0% +least very roughly many populations are + + + align:start position:0% +least very roughly many populations are +divided that way certainly humans were + + align:start position:0% +divided that way certainly humans were + + + align:start position:0% +divided that way certainly humans were +throughout much of our + + align:start position:0% +throughout much of our + + + align:start position:0% +throughout much of our +Evolutions uh that's why he calls it an + + align:start position:0% +Evolutions uh that's why he calls it an + + + align:start position:0% +Evolutions uh that's why he calls it an +is the island model because he's got the + + align:start position:0% +is the island model because he's got the + + + align:start position:0% +is the island model because he's got the +population divided into these different + + align:start position:0% +population divided into these different + + + align:start position:0% +population divided into these different +groups that are + + align:start position:0% +groups that are + + + align:start position:0% +groups that are +form he computed what well how big would + + align:start position:0% +form he computed what well how big would + + + align:start position:0% +form he computed what well how big would +those groups have to be you know in + + align:start position:0% +those groups have to be you know in + + + align:start position:0% +those groups have to be you know in +order to meet this effective population + + align:start position:0% +order to meet this effective population + + + align:start position:0% +order to meet this effective population +number + + align:start position:0% +number + + + align:start position:0% +number +definition uh and then what are the + + align:start position:0% +definition uh and then what are the + + + align:start position:0% +definition uh and then what are the +advantages of a population being divided + + align:start position:0% +advantages of a population being divided + + + align:start position:0% +advantages of a population being divided +that + + align:start position:0% +that + + + align:start position:0% +that +way and there are very clear advantages + + align:start position:0% +way and there are very clear advantages + + + align:start position:0% +way and there are very clear advantages +because when you have smaller groups + + align:start position:0% +because when you have smaller groups + + + align:start position:0% +because when you have smaller groups +you're going + + align:start position:0% +you're going + + + align:start position:0% +you're going +to the genetic differences that appear + + align:start position:0% +to the genetic differences that appear + + + align:start position:0% +to the genetic differences that appear +in the different groups will + + align:start position:0% +in the different groups will + + + align:start position:0% +in the different groups will +differ and so you will have small + + align:start position:0% +differ and so you will have small + + + align:start position:0% +differ and so you will have small +genetic differences appearing in these + + align:start position:0% +genetic differences appearing in these + + + align:start position:0% +genetic differences appearing in these +different + + align:start position:0% +different + + + align:start position:0% +different +groups and they'll be maintained if + + align:start position:0% +groups and they'll be maintained if + + + align:start position:0% +groups and they'll be maintained if +they're not interbreeding of course they + + align:start position:0% +they're not interbreeding of course they + + + align:start position:0% +they're not interbreeding of course they +would share the gene as soon as they + + align:start position:0% +would share the gene as soon as they + + + align:start position:0% +would share the gene as soon as they +exchanged if mates uh mating involved + + align:start position:0% +exchanged if mates uh mating involved + + + align:start position:0% +exchanged if mates uh mating involved +movement from one group to the other but + + align:start position:0% +movement from one group to the other but + + + align:start position:0% +movement from one group to the other but +if they're truly isolated that wouldn't + + align:start position:0% +if they're truly isolated that wouldn't + + + align:start position:0% +if they're truly isolated that wouldn't +be happening what would be the advantage + + align:start position:0% +be happening what would be the advantage + + + align:start position:0% +be happening what would be the advantage +to + + align:start position:0% +to + + + align:start position:0% +to +that what would be the advantage if a + + align:start position:0% +that what would be the advantage if a + + + align:start position:0% +that what would be the advantage if a +population were divided that way well + + align:start position:0% +population were divided that way well + + + align:start position:0% +population were divided that way well +think if there were some big change in + + align:start position:0% +think if there were some big change in + + + align:start position:0% +think if there were some big change in +the environment or new Predators + + align:start position:0% +the environment or new Predators + + + align:start position:0% +the environment or new Predators +appeared affecting all the + + align:start position:0% +appeared affecting all the + + + align:start position:0% +appeared affecting all the +groups well well if there's genetic + + align:start position:0% +groups well well if there's genetic + + + align:start position:0% +groups well well if there's genetic +differences in the groups then you're + + align:start position:0% +differences in the groups then you're + + + align:start position:0% +differences in the groups then you're +going to get better survival in some + + align:start position:0% +going to get better survival in some + + + align:start position:0% +going to get better survival in some +groups than in + + align:start position:0% +groups than in + + + align:start position:0% +groups than in +others and that's what Wright uh was uh + + align:start position:0% +others and that's what Wright uh was uh + + + align:start position:0% +others and that's what Wright uh was uh +what his model was able to + + align:start position:0% +what his model was able to + + + align:start position:0% +what his model was able to +show and that's one of the and one of + + align:start position:0% +show and that's one of the and one of + + + align:start position:0% +show and that's one of the and one of +the consequences of that + + align:start position:0% + + + + align:start position:0% + +model many points points out these what + + align:start position:0% +model many points points out these what + + + align:start position:0% +model many points points out these what +we he calls opposed selection tendencies + + align:start position:0% +we he calls opposed selection tendencies + + + align:start position:0% +we he calls opposed selection tendencies +that affect soci soci ity two very + + align:start position:0% +that affect soci soci ity two very + + + align:start position:0% +that affect soci soci ity two very +different effects uh in small groups + + align:start position:0% +different effects uh in small groups + + + align:start position:0% +different effects uh in small groups +that you have a greater chance of + + align:start position:0% +that you have a greater chance of + + + align:start position:0% +that you have a greater chance of +inbreeding and + + align:start position:0% +inbreeding and + + + align:start position:0% +inbreeding and +inbreeding uh you generally lowers + + align:start position:0% +inbreeding uh you generally lowers + + + align:start position:0% +inbreeding uh you generally lowers +individual Fitness depresses performance + + align:start position:0% +individual Fitness depresses performance + + + align:start position:0% +individual Fitness depresses performance +lowers genetic adaptibility so that is + + align:start position:0% +lowers genetic adaptibility so that is + + + align:start position:0% +lowers genetic adaptibility so that is +more likely to + + align:start position:0% +more likely to + + + align:start position:0% +more likely to +happen uh especially if you're well + + align:start position:0% +happen uh especially if you're well + + + align:start position:0% +happen uh especially if you're well +below that effective population + + align:start position:0% + + + + align:start position:0% + +number but in the small groups of + + align:start position:0% +number but in the small groups of + + + align:start position:0% +number but in the small groups of +related individuals there would be very + + align:start position:0% +related individuals there would be very + + + align:start position:0% +related individuals there would be very +clear advantages because of Greater + + align:start position:0% +clear advantages because of Greater + + + align:start position:0% +clear advantages because of Greater +amounts of altruistic behavior and close + + align:start position:0% +amounts of altruistic behavior and close + + + align:start position:0% +amounts of altruistic behavior and close +cooperation in the + + align:start position:0% + + + + align:start position:0% + +groups and then he talks about a slight + + align:start position:0% +groups and then he talks about a slight + + + align:start position:0% +groups and then he talks about a slight +a somewhat different concept assortative + + align:start position:0% +a somewhat different concept assortative + + + align:start position:0% +a somewhat different concept assortative +mating also known as homogamy and this + + align:start position:0% +mating also known as homogamy and this + + + align:start position:0% +mating also known as homogamy and this +is a tendency you find in all uh animal + + align:start position:0% +is a tendency you find in all uh animal + + + align:start position:0% +is a tendency you find in all uh animal +groups and certainly in humans a + + align:start position:0% +groups and certainly in humans a + + + align:start position:0% +groups and certainly in humans a +tendency to choose a mate that looks + + align:start position:0% +tendency to choose a mate that looks + + + align:start position:0% +tendency to choose a mate that looks +similar to oneself or one's close + + align:start position:0% +similar to oneself or one's close + + + align:start position:0% +similar to oneself or one's close +relatives + + align:start position:0% + + + + align:start position:0% + +uh and that what does that mean well it + + align:start position:0% +uh and that what does that mean well it + + + align:start position:0% +uh and that what does that mean well it +probably means that the + + align:start position:0% + + + + align:start position:0% + +group I was talking to the TA about my + + align:start position:0% +group I was talking to the TA about my + + + align:start position:0% +group I was talking to the TA about my +worries that the second projector will + + align:start position:0% +worries that the second projector will + + + align:start position:0% +worries that the second projector will +go out too it's a small small chance + + align:start position:0% +go out too it's a small small chance + + + align:start position:0% +go out too it's a small small chance +it's in the connection but I + + align:start position:0% +it's in the connection but I + + + align:start position:0% +it's in the connection but I +don't so + + align:start position:0% +don't so + + + align:start position:0% +don't so +far so + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% + + + + align:start position:0% + +what would be if you're going to always + + align:start position:0% +what would be if you're going to always + + + align:start position:0% +what would be if you're going to always +choose a mate someone that looks similar + + align:start position:0% +choose a mate someone that looks similar + + + align:start position:0% +choose a mate someone that looks similar +to yourself then the chances that you + + align:start position:0% +to yourself then the chances that you + + + align:start position:0% +to yourself then the chances that you +share genes of course are might be + + align:start position:0% +share genes of course are might be + + + align:start position:0% +share genes of course are might be +greater but that's only in a relatively + + align:start position:0% +greater but that's only in a relatively + + + align:start position:0% +greater but that's only in a relatively +small number of genes that affect the + + align:start position:0% +small number of genes that affect the + + + align:start position:0% +small number of genes that affect the +superficial + + align:start position:0% +superficial + + + align:start position:0% +superficial +appearance all + + align:start position:0% + + + + align:start position:0% + +right that was the end of that class + + align:start position:0% +right that was the end of that class + + + align:start position:0% +right that was the end of that class +and + + align:start position:0% + + + + align:start position:0% + +then I ask you to read the chapter on + + align:start position:0% +then I ask you to read the chapter on + + + align:start position:0% +then I ask you to read the chapter on +genes genetic influences on social + + align:start position:0% +genes genetic influences on social + + + align:start position:0% +genes genetic influences on social +behavior + + align:start position:0% +behavior + + + align:start position:0% +behavior +uh we want to know the difference + + align:start position:0% +uh we want to know the difference + + + align:start position:0% +uh we want to know the difference +between genetic + + align:start position:0% +between genetic + + + align:start position:0% +between genetic +determinants of Behavioral + + align:start position:0% +determinants of Behavioral + + + align:start position:0% +determinants of Behavioral +traits genetic determination and what + + align:start position:0% +traits genetic determination and what + + + align:start position:0% +traits genetic determination and what +sociobiologists uh what their view of + + align:start position:0% +sociobiologists uh what their view of + + + align:start position:0% +sociobiologists uh what their view of +concerning genes and behavior is because + + align:start position:0% +concerning genes and behavior is because + + + align:start position:0% +concerning genes and behavior is because +you know that they've been accused a lot + + align:start position:0% + + + + align:start position:0% + +of basically saying genes are us you + + align:start position:0% +of basically saying genes are us you + + + align:start position:0% +of basically saying genes are us you +know major Trends are + + align:start position:0% +know major Trends are + + + align:start position:0% +know major Trends are +genetic uh do the genes determine the + + align:start position:0% +genetic uh do the genes determine the + + + align:start position:0% +genetic uh do the genes determine the +development of specific social behaviors + + align:start position:0% +development of specific social behaviors + + + align:start position:0% +development of specific social behaviors +and first of all I want you to think + + align:start position:0% +and first of all I want you to think + + + align:start position:0% +and first of all I want you to think +back to our discussion of ethology we + + align:start position:0% +back to our discussion of ethology we + + + align:start position:0% +back to our discussion of ethology we +talked about Conor Lawrence and fixed + + align:start position:0% +talked about Conor Lawrence and fixed + + + align:start position:0% +talked about Conor Lawrence and fixed +action + + align:start position:0% +action + + + align:start position:0% +action +patterns because ethology was founded on + + align:start position:0% +patterns because ethology was founded on + + + align:start position:0% +patterns because ethology was founded on +the basis of the hereditability + + align:start position:0% +the basis of the hereditability + + + align:start position:0% +the basis of the hereditability +fixed action patterns and many of them + + align:start position:0% +fixed action patterns and many of them + + + align:start position:0% +fixed action patterns and many of them +are of course social + + align:start position:0% + + + + align:start position:0% + +behavior but we also knew that a fixed + + align:start position:0% +behavior but we also knew that a fixed + + + align:start position:0% +behavior but we also knew that a fixed +action pattern is not you know totally + + align:start position:0% +action pattern is not you know totally + + + align:start position:0% +action pattern is not you know totally +determined by the genes it it depends on + + align:start position:0% +determined by the genes it it depends on + + + align:start position:0% +determined by the genes it it depends on +motivational + + align:start position:0% +motivational + + + align:start position:0% +motivational +levels uh and the motivational intensity + + align:start position:0% +levels uh and the motivational intensity + + + align:start position:0% +levels uh and the motivational intensity +is influenced by many environmental + + align:start position:0% +is influenced by many environmental + + + align:start position:0% +is influenced by many environmental +variables but the underlying action + + align:start position:0% +variables but the underlying action + + + align:start position:0% +variables but the underlying action +pattern especially on the motorcyle side + + align:start position:0% +pattern especially on the motorcyle side + + + align:start position:0% +pattern especially on the motorcyle side +the fixed motor pattern is considered + + align:start position:0% +the fixed motor pattern is considered + + + align:start position:0% +the fixed motor pattern is considered +genetic and there's plenty of evidence + + align:start position:0% +genetic and there's plenty of evidence + + + align:start position:0% +genetic and there's plenty of evidence +for + + align:start position:0% +for + + + align:start position:0% +for +that you can even get mouse + + align:start position:0% +that you can even get mouse + + + align:start position:0% +that you can even get mouse +populations uh that are genetically + + align:start position:0% +populations uh that are genetically + + + align:start position:0% +populations uh that are genetically +different that + + align:start position:0% +different that + + + align:start position:0% +different that +show differences in details of grooming + + align:start position:0% +show differences in details of grooming + + + align:start position:0% +show differences in details of grooming +behavior um and all the members that are + + align:start position:0% +behavior um and all the members that are + + + align:start position:0% +behavior um and all the members that are +have one gene will one genetic variant + + align:start position:0% +have one gene will one genetic variant + + + align:start position:0% +have one gene will one genetic variant +will show one type and all the + + align:start position:0% +will show one type and all the + + + align:start position:0% +will show one type and all the +individuals are almost identical and the + + align:start position:0% +individuals are almost identical and the + + + align:start position:0% +individuals are almost identical and the +other groups are a little bit different + + align:start position:0% +other groups are a little bit different + + + align:start position:0% +other groups are a little bit different +certainly pretty strong evidence for + + align:start position:0% +certainly pretty strong evidence for + + + align:start position:0% +certainly pretty strong evidence for +genetic influences on that behavior that + + align:start position:0% +genetic influences on that behavior that + + + align:start position:0% +genetic influences on that behavior that +is only social behavior of course if + + align:start position:0% +is only social behavior of course if + + + align:start position:0% +is only social behavior of course if +there's grooming of individuals grooming + + align:start position:0% +there's grooming of individuals grooming + + + align:start position:0% +there's grooming of individuals grooming +of each other by in in a + + align:start position:0% + + + + align:start position:0% + +group but I want you next to remember + + align:start position:0% +group but I want you next to remember + + + align:start position:0% +group but I want you next to remember +that the nature nurture + + align:start position:0% +that the nature nurture + + + align:start position:0% +that the nature nurture +problem + + align:start position:0% +problem + + + align:start position:0% +problem +uh the way that controversy is normally + + align:start position:0% +uh the way that controversy is normally + + + align:start position:0% +uh the way that controversy is normally +dealt with now especially in so soci + + align:start position:0% +dealt with now especially in so soci + + + align:start position:0% +dealt with now especially in so soci +biology is to remember that where are we + + align:start position:0% + + + + align:start position:0% + +here that both nature and nurture are + + align:start position:0% +here that both nature and nurture are + + + align:start position:0% +here that both nature and nurture are +always + + align:start position:0% +always + + + align:start position:0% +always +involved you never have a purely genetic + + align:start position:0% + + + + align:start position:0% + +determinations and the other thing that + + align:start position:0% +determinations and the other thing that + + + align:start position:0% +determinations and the other thing that +elcock points out here is that the + + align:start position:0% +elcock points out here is that the + + + align:start position:0% +elcock points out here is that the +genetic studies most relevant to + + align:start position:0% +genetic studies most relevant to + + + align:start position:0% +genetic studies most relevant to +sociobiology are not developmental + + align:start position:0% +sociobiology are not developmental + + + align:start position:0% +sociobiology are not developmental +genetics at all but population + + align:start position:0% + + + + align:start position:0% + +genetics they deal most directly with + + align:start position:0% +genetics they deal most directly with + + + align:start position:0% +genetics they deal most directly with +the consequences of population changes + + align:start position:0% +the consequences of population changes + + + align:start position:0% +the consequences of population changes +and the frequency of different variants + + align:start position:0% +and the frequency of different variants + + + align:start position:0% +and the frequency of different variants +or alals of given genes not with the + + align:start position:0% +or alals of given genes not with the + + + align:start position:0% +or alals of given genes not with the +means by which these Al shaper influence + + align:start position:0% +means by which these Al shaper influence + + + align:start position:0% +means by which these Al shaper influence +the pathways the biochemical Pathways of + + align:start position:0% +the pathways the biochemical Pathways of + + + align:start position:0% +the pathways the biochemical Pathways of +developing + + align:start position:0% +developing + + + align:start position:0% +developing +individuals and so a lot of times the + + align:start position:0% +individuals and so a lot of times the + + + align:start position:0% +individuals and so a lot of times the +criticisms that sociobiologists are + + align:start position:0% +criticisms that sociobiologists are + + + align:start position:0% +criticisms that sociobiologists are +genetic determinists about social + + align:start position:0% +genetic determinists about social + + + align:start position:0% +genetic determinists about social +behavior is because they don't + + align:start position:0% +behavior is because they don't + + + align:start position:0% +behavior is because they don't +distinguish between ultimate approximate + + align:start position:0% +distinguish between ultimate approximate + + + align:start position:0% +distinguish between ultimate approximate +research and + + align:start position:0% + + + + align:start position:0% + +biology and uh he considers + + align:start position:0% +biology and uh he considers + + + align:start position:0% +biology and uh he considers +that the main problem with these + + align:start position:0% + + + + align:start position:0% + +criticisms + + align:start position:0% +criticisms + + + align:start position:0% +criticisms +uh especially the critics that argue in + + align:start position:0% +uh especially the critics that argue in + + + align:start position:0% +uh especially the critics that argue in +this extreme passion they talk about + + align:start position:0% +this extreme passion they talk about + + + align:start position:0% +this extreme passion they talk about +they say sociobiologists are talking + + align:start position:0% +they say sociobiologists are talking + + + align:start position:0% +they say sociobiologists are talking +about traits that are hereditary fixed + + align:start position:0% +about traits that are hereditary fixed + + + align:start position:0% +about traits that are hereditary fixed +inevitable unchangeable except by Fus + + align:start position:0% +inevitable unchangeable except by Fus + + + align:start position:0% +inevitable unchangeable except by Fus +selection for hereditary Alternatives + + align:start position:0% +selection for hereditary Alternatives + + + align:start position:0% +selection for hereditary Alternatives +well we know that that's can't be true + + align:start position:0% +well we know that that's can't be true + + + align:start position:0% +well we know that that's can't be true +because of + + align:start position:0% +because of + + + align:start position:0% +because of +the of the nature of what we know about + + align:start position:0% +the of the nature of what we know about + + + align:start position:0% +the of the nature of what we know about +how genes influence + + align:start position:0% + + + + align:start position:0% + +behavior but let me ask you about just + + align:start position:0% +behavior but let me ask you about just + + + align:start position:0% +behavior but let me ask you about just +leaving these slides for a minute what + + align:start position:0% +leaving these slides for a minute what + + + align:start position:0% +leaving these slides for a minute what +about these studies of ethology where + + align:start position:0% +about these studies of ethology where + + + align:start position:0% +about these studies of ethology where +they're dealing with like the cat um + + align:start position:0% +they're dealing with like the cat um + + + align:start position:0% +they're dealing with like the cat um +mating behavior for + + align:start position:0% +mating behavior for + + + align:start position:0% +mating behavior for +example and you can find relationships + + align:start position:0% +example and you can find relationships + + + align:start position:0% +example and you can find relationships +across species and the behavior is + + align:start position:0% +across species and the behavior is + + + align:start position:0% +across species and the behavior is +almost identical in different groups is + + align:start position:0% +almost identical in different groups is + + + align:start position:0% +almost identical in different groups is +that not social behavior and isn't it + + align:start position:0% +that not social behavior and isn't it + + + align:start position:0% +that not social behavior and isn't it +genetically + + align:start position:0% +genetically + + + align:start position:0% +genetically +determined and I would argue that it + + align:start position:0% +determined and I would argue that it + + + align:start position:0% +determined and I would argue that it +certainly is you know but there are many + + align:start position:0% +certainly is you know but there are many + + + align:start position:0% +certainly is you know but there are many +learned aspects as well okay so you will + + align:start position:0% +learned aspects as well okay so you will + + + align:start position:0% +learned aspects as well okay so you will +find individual differences in group + + align:start position:0% +find individual differences in group + + + align:start position:0% +find individual differences in group +especially on the stimulus + + align:start position:0% +especially on the stimulus + + + align:start position:0% +especially on the stimulus +side uh they develop different + + align:start position:0% +side uh they develop different + + + align:start position:0% +side uh they develop different +preferences and so forth even when the + + align:start position:0% +preferences and so forth even when the + + + align:start position:0% +preferences and so forth even when the +motor motor side is fairly + + align:start position:0% + + + + align:start position:0% + +fixed then Alcock talks about this + + align:start position:0% +fixed then Alcock talks about this + + + align:start position:0% +fixed then Alcock talks about this +review done in 1998 so that was a long + + align:start position:0% +review done in 1998 so that was a long + + + align:start position:0% +review done in 1998 so that was a long +time after the books appeared in + + align:start position:0% +time after the books appeared in + + + align:start position:0% +time after the books appeared in + + align:start position:0% + + + + align:start position:0% + +uh about uh the study he called it the + + align:start position:0% +uh about uh the study he called it the + + + align:start position:0% +uh about uh the study he called it the +study of genetically determined social + + align:start position:0% +study of genetically determined social + + + align:start position:0% +study of genetically determined social +behavior that was the main theme of the + + align:start position:0% +behavior that was the main theme of the + + + align:start position:0% +behavior that was the main theme of the +the + + align:start position:0% +the + + + align:start position:0% +the +review but Wilson actually devotes an + + align:start position:0% +review but Wilson actually devotes an + + + align:start position:0% +review but Wilson actually devotes an +entire chapter in his book to explain + + align:start position:0% +entire chapter in his book to explain + + + align:start position:0% +entire chapter in his book to explain +that although genes are essential for + + align:start position:0% +that although genes are essential for + + + align:start position:0% +that although genes are essential for +the development of behavior they don't + + align:start position:0% +the development of behavior they don't + + + align:start position:0% +the development of behavior they don't +determine it by + + align:start position:0% +determine it by + + + align:start position:0% +determine it by +themselves of course I think most people + + align:start position:0% +themselves of course I think most people + + + align:start position:0% +themselves of course I think most people +who look at genes and Behavior now would + + align:start position:0% +who look at genes and Behavior now would + + + align:start position:0% +who look at genes and Behavior now would +say that that would have to be + + align:start position:0% +say that that would have to be + + + align:start position:0% +say that that would have to be +true you can go to an extreme Like + + align:start position:0% +true you can go to an extreme Like + + + align:start position:0% +true you can go to an extreme Like +Richard Alexander did here he just + + align:start position:0% +Richard Alexander did here he just + + + align:start position:0% +Richard Alexander did here he just +points out + + align:start position:0% +points out + + + align:start position:0% +points out +that genetic + + align:start position:0% +that genetic + + + align:start position:0% +that genetic +determinism is a ridiculous argument if + + align:start position:0% +determinism is a ridiculous argument if + + + align:start position:0% +determinism is a ridiculous argument if +you exclude environment completely + + align:start position:0% +you exclude environment completely + + + align:start position:0% +you exclude environment completely +environment outside the DNA because it's + + align:start position:0% +environment outside the DNA because it's + + + align:start position:0% +environment outside the DNA because it's +always there and there's always + + align:start position:0% +always there and there's always + + + align:start position:0% +always there and there's always +variables which of course makes us + + align:start position:0% +variables which of course makes us + + + align:start position:0% +variables which of course makes us +wonder why the claim has been so + + align:start position:0% +wonder why the claim has been so + + + align:start position:0% +wonder why the claim has been so +persistent so I'll deal with that + + align:start position:0% +persistent so I'll deal with that + + + align:start position:0% +persistent so I'll deal with that +next but this is the way Al Al + + align:start position:0% +next but this is the way Al Al + + + align:start position:0% +next but this is the way Al Al +summarizes it in basically about at + + align:start position:0% +summarizes it in basically about at + + + align:start position:0% +summarizes it in basically about at +least the chemical environment of the + + align:start position:0% +least the chemical environment of the + + + align:start position:0% +least the chemical environment of the +DNA is always involved and that is + + align:start position:0% +DNA is always involved and that is + + + align:start position:0% +DNA is always involved and that is +very but I want to point out that a lot + + align:start position:0% +very but I want to point out that a lot + + + align:start position:0% +very but I want to point out that a lot +of people who argue against the + + align:start position:0% +of people who argue against the + + + align:start position:0% +of people who argue against the +influence of genes they're much more + + align:start position:0% +influence of genes they're much more + + + align:start position:0% +influence of genes they're much more +concerned they're much more they just + + align:start position:0% +concerned they're much more they just + + + align:start position:0% +concerned they're much more they just +feel that environment and learning are a + + align:start position:0% +feel that environment and learning are a + + + align:start position:0% +feel that environment and learning are a +lot more important okay that you can + + align:start position:0% +lot more important okay that you can + + + align:start position:0% +lot more important okay that you can +discount a lot of the genetic factors + + align:start position:0% +discount a lot of the genetic factors + + + align:start position:0% +discount a lot of the genetic factors +they also get upset by thinking about + + align:start position:0% +they also get upset by thinking about + + + align:start position:0% +they also get upset by thinking about +behavior in a totally deterministic way + + align:start position:0% +behavior in a totally deterministic way + + + align:start position:0% +behavior in a totally deterministic way +they basically object to the basic + + align:start position:0% +they basically object to the basic + + + align:start position:0% +they basically object to the basic +Assumption of the scientist who's trying + + align:start position:0% +Assumption of the scientist who's trying + + + align:start position:0% +Assumption of the scientist who's trying +to + + align:start position:0% +to + + + align:start position:0% +to +explain you know physical causes of the + + align:start position:0% +explain you know physical causes of the + + + align:start position:0% +explain you know physical causes of the +effects of whatever they're + + align:start position:0% +effects of whatever they're + + + align:start position:0% +effects of whatever they're +investigating whether it's Behavior or + + align:start position:0% +investigating whether it's Behavior or + + + align:start position:0% +investigating whether it's Behavior or +anything else I mean psychologists can't + + align:start position:0% +anything else I mean psychologists can't + + + align:start position:0% +anything else I mean psychologists can't +do their work without assuming that + + align:start position:0% +do their work without assuming that + + + align:start position:0% +do their work without assuming that +there are specific effects on + + align:start position:0% +there are specific effects on + + + align:start position:0% +there are specific effects on +Behavior Uh including genetic + + align:start position:0% +Behavior Uh including genetic + + + align:start position:0% +Behavior Uh including genetic +effects and so there are people like it + + align:start position:0% +effects and so there are people like it + + + align:start position:0% +effects and so there are people like it +they don't like in general the + + align:start position:0% +they don't like in general the + + + align:start position:0% +they don't like in general the +deterministic approach that scientists + + align:start position:0% +deterministic approach that scientists + + + align:start position:0% +deterministic approach that scientists +take so it's a lot of times the + + align:start position:0% +take so it's a lot of times the + + + align:start position:0% +take so it's a lot of times the +criticisms of those people is much + + align:start position:0% +criticisms of those people is much + + + align:start position:0% +criticisms of those people is much +broader than just talking about + + align:start position:0% +broader than just talking about + + + align:start position:0% +broader than just talking about +sociobiology but sociobiology is what + + align:start position:0% +sociobiology but sociobiology is what + + + align:start position:0% +sociobiology but sociobiology is what +figures their ey more than + + align:start position:0% + + + + align:start position:0% + +anything so this is an enduring myth + + align:start position:0% +anything so this is an enduring myth + + + align:start position:0% +anything so this is an enduring myth +according to + + align:start position:0% +according to + + + align:start position:0% +according to +elcock despite the fact that all + + align:start position:0% +elcock despite the fact that all + + + align:start position:0% +elcock despite the fact that all +biologists know that every trait of + + align:start position:0% +biologists know that every trait of + + + align:start position:0% +biologists know that every trait of +every organism develops through through + + align:start position:0% +every organism develops through through + + + align:start position:0% +every organism develops through through +this interaction of genes and + + align:start position:0% +this interaction of genes and + + + align:start position:0% +this interaction of genes and +environment but I think the myth + + align:start position:0% +environment but I think the myth + + + align:start position:0% +environment but I think the myth +persists they don't like this approach + + align:start position:0% +persists they don't like this approach + + + align:start position:0% +persists they don't like this approach +as I just pointed out for much more + + align:start position:0% +as I just pointed out for much more + + + align:start position:0% +as I just pointed out for much more +General reasons that have to do just + + align:start position:0% +General reasons that have to do just + + + align:start position:0% +General reasons that have to do just +with social biology so this is a + + align:start position:0% +with social biology so this is a + + + align:start position:0% +with social biology so this is a +convenience Truman to set it up like + + align:start position:0% +convenience Truman to set it up like + + + align:start position:0% +convenience Truman to set it up like +that I think it's the nature of human + + align:start position:0% +that I think it's the nature of human + + + align:start position:0% +that I think it's the nature of human +psychology we believe in our ability to + + align:start position:0% +psychology we believe in our ability to + + + align:start position:0% +psychology we believe in our ability to +change our behavior and other people's + + align:start position:0% +change our behavior and other people's + + + align:start position:0% +change our behavior and other people's +behavior + + align:start position:0% +behavior + + + align:start position:0% +behavior +and for many people the flexibility of + + align:start position:0% +and for many people the flexibility of + + + align:start position:0% +and for many people the flexibility of +human behavior is taken as mistakenly + + align:start position:0% +human behavior is taken as mistakenly + + + align:start position:0% +human behavior is taken as mistakenly +taken as evidence that cultural factors + + align:start position:0% +taken as evidence that cultural factors + + + align:start position:0% +taken as evidence that cultural factors +are the only real determinant of our + + align:start position:0% +are the only real determinant of our + + + align:start position:0% +are the only real determinant of our +actions in fact in some of the meetings + + align:start position:0% +actions in fact in some of the meetings + + + align:start position:0% +actions in fact in some of the meetings +where these arguments have come up uh + + align:start position:0% +where these arguments have come up uh + + + align:start position:0% +where these arguments have come up uh +people usually outside of sociobiology + + align:start position:0% +people usually outside of sociobiology + + + align:start position:0% +people usually outside of sociobiology +of course or behavioral + + align:start position:0% +of course or behavioral + + + align:start position:0% +of course or behavioral +biology we argue that culture is the + + align:start position:0% +biology we argue that culture is the + + + align:start position:0% +biology we argue that culture is the +only real determinant of human + + align:start position:0% +only real determinant of human + + + align:start position:0% +only real determinant of human +behavior + + align:start position:0% +behavior + + + align:start position:0% +behavior +and then I also feel that championing + + align:start position:0% +and then I also feel that championing + + + align:start position:0% +and then I also feel that championing +Free Will and freedom of action is + + align:start position:0% +Free Will and freedom of action is + + + align:start position:0% +Free Will and freedom of action is +pretty understandably very popular in + + align:start position:0% +pretty understandably very popular in + + + align:start position:0% +pretty understandably very popular in +fact I think humans haven't evolved an + + align:start position:0% +fact I think humans haven't evolved an + + + align:start position:0% +fact I think humans haven't evolved an +enthusiasm for freedom of action and a + + align:start position:0% +enthusiasm for freedom of action and a + + + align:start position:0% +enthusiasm for freedom of action and a +belief in Free Will so I think we should + + align:start position:0% +belief in Free Will so I think we should + + + align:start position:0% +belief in Free Will so I think we should +be thinking like sociobiologists about + + align:start position:0% +be thinking like sociobiologists about + + + align:start position:0% +be thinking like sociobiologists about +that why do does everybody feel that I + + align:start position:0% +that why do does everybody feel that I + + + align:start position:0% +that why do does everybody feel that I +mean yes there are some intellectuals + + align:start position:0% +mean yes there are some intellectuals + + + align:start position:0% +mean yes there are some intellectuals +that take a very deterministic approach + + align:start position:0% +that take a very deterministic approach + + + align:start position:0% +that take a very deterministic approach +say we think we have free will but we + + align:start position:0% +say we think we have free will but we + + + align:start position:0% +say we think we have free will but we +don't and they're being philosophical + + align:start position:0% +don't and they're being philosophical + + + align:start position:0% +don't and they're being philosophical +but in their own behavior do they + + align:start position:0% +but in their own behavior do they + + + align:start position:0% +but in their own behavior do they +believe in Free Will you bet you know we + + align:start position:0% +believe in Free Will you bet you know we + + + align:start position:0% +believe in Free Will you bet you know we +all do I think it's inherited and I + + align:start position:0% +all do I think it's inherited and I + + + align:start position:0% +all do I think it's inherited and I +think it's adaptive to be that + + align:start position:0% + + + + align:start position:0% + +way all + + align:start position:0% +way all + + + align:start position:0% +way all +right can a difference in one ilal + + align:start position:0% +right can a difference in one ilal + + + align:start position:0% +right can a difference in one ilal +change of + + align:start position:0% +change of + + + align:start position:0% +change of +behavior and he has this interesting + + align:start position:0% +behavior and he has this interesting + + + align:start position:0% +behavior and he has this interesting +figure + + align:start position:0% +figure + + + align:start position:0% +figure +31 to expl expl how a difference in one + + align:start position:0% +31 to expl expl how a difference in one + + + align:start position:0% +31 to expl expl how a difference in one +ilil and he has them represented by the + + align:start position:0% +ilil and he has them represented by the + + + align:start position:0% +ilil and he has them represented by the +capital and small B could result in a + + align:start position:0% +capital and small B could result in a + + + align:start position:0% +capital and small B could result in a +behavioral difference between two adults + + align:start position:0% +behavioral difference between two adults + + + align:start position:0% +behavioral difference between two adults +and it's a kind of multiplier effect + + align:start position:0% +and it's a kind of multiplier effect + + + align:start position:0% +and it's a kind of multiplier effect +this is the way I've reproduced it + + align:start position:0% + + + + align:start position:0% + +um so you start with the fertilized egg + + align:start position:0% +um so you start with the fertilized egg + + + align:start position:0% +um so you start with the fertilized egg +okay and here's one individual notice + + align:start position:0% +okay and here's one individual notice + + + align:start position:0% +okay and here's one individual notice +he's got these most of the genes are the + + align:start position:0% +he's got these most of the genes are the + + + align:start position:0% +he's got these most of the genes are the +same except that this Gene here and this + + align:start position:0% +same except that this Gene here and this + + + align:start position:0% +same except that this Gene here and this +could be you know Big B little + + align:start position:0% +could be you know Big B little + + + align:start position:0% +could be you know Big B little +B but it's different from this + + align:start position:0% +B but it's different from this + + + align:start position:0% +B but it's different from this +individual who has the two recessive + + align:start position:0% +individual who has the two recessive + + + align:start position:0% +individual who has the two recessive +genes the same Locus so his behavior if + + align:start position:0% +genes the same Locus so his behavior if + + + align:start position:0% +genes the same Locus so his behavior if +it's going to be affected will be any + + align:start position:0% +it's going to be affected will be any + + + align:start position:0% +it's going to be affected will be any +effect of that one + + align:start position:0% +effect of that one + + + align:start position:0% +effect of that one +alil and this person doesn't even have + + align:start position:0% +alil and this person doesn't even have + + + align:start position:0% +alil and this person doesn't even have +that alil so he's got to be affected by + + align:start position:0% +that alil so he's got to be affected by + + + align:start position:0% +that alil so he's got to be affected by +the other one okay it's just one gene so + + align:start position:0% +the other one okay it's just one gene so + + + align:start position:0% +the other one okay it's just one gene so +one protein + + align:start position:0% +one protein + + + align:start position:0% +one protein +and that genetic difference of course U + + align:start position:0% +and that genetic difference of course U + + + align:start position:0% +and that genetic difference of course U +will interact with the environment and + + align:start position:0% +will interact with the environment and + + + align:start position:0% +will interact with the environment and +the environment can be + + align:start position:0% +the environment can be + + + align:start position:0% +the environment can be +different so the effects if the + + align:start position:0% +different so the effects if the + + + align:start position:0% +different so the effects if the +environment's different to these two + + align:start position:0% +environment's different to these two + + + align:start position:0% +environment's different to these two +individuals you're going to get + + align:start position:0% +individuals you're going to get + + + align:start position:0% +individuals you're going to get +differences that affects the adult but + + align:start position:0% +differences that affects the adult but + + + align:start position:0% +differences that affects the adult but +then as they develop of course and + + align:start position:0% +then as they develop of course and + + + align:start position:0% +then as they develop of course and +neurons develop we know that there are + + align:start position:0% +neurons develop we know that there are + + + align:start position:0% +neurons develop we know that there are +many effects of environment on that that + + align:start position:0% +many effects of environment on that that + + + align:start position:0% +many effects of environment on that that +are independent of these but that in + + align:start position:0% +are independent of these but that in + + + align:start position:0% +are independent of these but that in +fact is Sol + + align:start position:0% +fact is Sol + + + align:start position:0% +fact is Sol +could make a difference in the way these + + align:start position:0% +could make a difference in the way these + + + align:start position:0% +could make a difference in the way these +things happen during development so the + + align:start position:0% +things happen during development so the + + + align:start position:0% +things happen during development so the +the effect + + align:start position:0% +the effect + + + align:start position:0% +the effect +here could be present throughout + + align:start position:0% +here could be present throughout + + + align:start position:0% +here could be present throughout +development with environments as long as + + align:start position:0% +development with environments as long as + + + align:start position:0% +development with environments as long as +they're slightly + + align:start position:0% +they're slightly + + + align:start position:0% +they're slightly +different you know could lead to pretty + + align:start position:0% +different you know could lead to pretty + + + align:start position:0% +different you know could lead to pretty +big differences in two adults in spite + + align:start position:0% +big differences in two adults in spite + + + align:start position:0% +big differences in two adults in spite +of that it + + align:start position:0% + + + + align:start position:0% + +ill and yet the differences developed + + align:start position:0% +ill and yet the differences developed + + + align:start position:0% +ill and yet the differences developed +specifically because of that one genetic + + align:start position:0% +specifically because of that one genetic + + + align:start position:0% +specifically because of that one genetic +difference so that's all that we we're + + align:start position:0% +difference so that's all that we we're + + + align:start position:0% +difference so that's all that we we're +talking about here so let's talk exactly + + align:start position:0% +talking about here so let's talk exactly + + + align:start position:0% +talking about here so let's talk exactly +how and why the relative frequency of + + align:start position:0% +how and why the relative frequency of + + + align:start position:0% +how and why the relative frequency of +the two Al could change over multiple + + align:start position:0% +the two Al could change over multiple + + + align:start position:0% +the two Al could change over multiple +Generations let's raise the + + align:start position:0% +Generations let's raise the + + + align:start position:0% +Generations let's raise the +possibilities from what we know okay and + + align:start position:0% +possibilities from what we know okay and + + + align:start position:0% +possibilities from what we know okay and +these are the things I could think + + align:start position:0% +these are the things I could think + + + align:start position:0% +these are the things I could think +of why B could increase and the + + align:start position:0% +of why B could increase and the + + + align:start position:0% +of why B could increase and the +recessive trait could + + align:start position:0% +recessive trait could + + + align:start position:0% +recessive trait could +decrease first of all if B the small the + + align:start position:0% +decrease first of all if B the small the + + + align:start position:0% +decrease first of all if B the small the +recessive trait resulted in death before + + align:start position:0% +recessive trait resulted in death before + + + align:start position:0% +recessive trait resulted in death before +the age of reproduction more often than + + align:start position:0% +the age of reproduction more often than + + + align:start position:0% +the age of reproduction more often than +the dominant + + align:start position:0% +the dominant + + + align:start position:0% +the dominant +trait I'm just going to refer to them + + align:start position:0% +trait I'm just going to refer to them + + + align:start position:0% +trait I'm just going to refer to them +that way because of this that's a common + + align:start position:0% +that way because of this that's a common + + + align:start position:0% +that way because of this that's a common +way of + + align:start position:0% +way of + + + align:start position:0% +way of +expressing for one ilal the recessive + + align:start position:0% +expressing for one ilal the recessive + + + align:start position:0% +expressing for one ilal the recessive +and dominant Al infecting that + + align:start position:0% +and dominant Al infecting that + + + align:start position:0% +and dominant Al infecting that +Gene a second thing could be be could + + align:start position:0% +Gene a second thing could be be could + + + align:start position:0% +Gene a second thing could be be could +result in behavioral a behavioral + + align:start position:0% +result in behavioral a behavioral + + + align:start position:0% +result in behavioral a behavioral +difference that reduce the probability + + align:start position:0% +difference that reduce the probability + + + align:start position:0% +difference that reduce the probability +of successful reproduction in a + + align:start position:0% +of successful reproduction in a + + + align:start position:0% +of successful reproduction in a +particular environment but not in all + + align:start position:0% +particular environment but not in all + + + align:start position:0% +particular environment but not in all +environments so at least in that + + align:start position:0% +environments so at least in that + + + align:start position:0% +environments so at least in that +particular environment the genes would + + align:start position:0% +particular environment the genes would + + + align:start position:0% +particular environment the genes would +change in their + + align:start position:0% +change in their + + + align:start position:0% +change in their +frequency all we need is probability + + align:start position:0% +frequency all we need is probability + + + align:start position:0% +frequency all we need is probability +differences and if the recessive trait + + align:start position:0% +differences and if the recessive trait + + + align:start position:0% +differences and if the recessive trait +resulted in no change in probability of + + align:start position:0% +resulted in no change in probability of + + + align:start position:0% +resulted in no change in probability of +reproduction but it did reduce parental + + align:start position:0% +reproduction but it did reduce parental + + + align:start position:0% +reproduction but it did reduce parental +care that alone you see would reduce in + + align:start position:0% +care that alone you see would reduce in + + + align:start position:0% +care that alone you see would reduce in +would result because you would have + + align:start position:0% +would result because you would have + + + align:start position:0% +would result because you would have +statistically anyway less + + align:start position:0% +statistically anyway less + + + align:start position:0% +statistically anyway less +Survival Of The Offspring and that would + + align:start position:0% +Survival Of The Offspring and that would + + + align:start position:0% +Survival Of The Offspring and that would +be enough then to lead to changes over + + align:start position:0% +be enough then to lead to changes over + + + align:start position:0% +be enough then to lead to changes over +multiple Generations in the frequency of + + align:start position:0% +multiple Generations in the frequency of + + + align:start position:0% +multiple Generations in the frequency of +those two + + align:start position:0% + + + + align:start position:0% + +genes all right + + align:start position:0% +genes all right + + + align:start position:0% +genes all right +so so let's talk about breeding or + + align:start position:0% +so so let's talk about breeding or + + + align:start position:0% +so so let's talk about breeding or +behavioral traits we know that animals + + align:start position:0% +behavioral traits we know that animals + + + align:start position:0% +behavioral traits we know that animals +are bred for physical traits you know + + align:start position:0% +are bred for physical traits you know + + + align:start position:0% +are bred for physical traits you know +how dogs have been bred to Loop + + align:start position:0% +how dogs have been bred to Loop + + + align:start position:0% +how dogs have been bred to Loop +different okay and + + align:start position:0% +different okay and + + + align:start position:0% +different okay and +uh it's we see it especially in farm + + align:start position:0% +uh it's we see it especially in farm + + + align:start position:0% +uh it's we see it especially in farm +animals we've read beef cattle so + + align:start position:0% +animals we've read beef cattle so + + + align:start position:0% +animals we've read beef cattle so +they're meteor + + align:start position:0% +they're meteor + + + align:start position:0% +they're meteor +uh what about Behavior it's been done in + + align:start position:0% +uh what about Behavior it's been done in + + + align:start position:0% +uh what about Behavior it's been done in +the laboratory for a number of + + align:start position:0% +the laboratory for a number of + + + align:start position:0% +the laboratory for a number of +particular behavioral traits where you + + align:start position:0% +particular behavioral traits where you + + + align:start position:0% +particular behavioral traits where you +ignore the phys any physical differences + + align:start position:0% +ignore the phys any physical differences + + + align:start position:0% +ignore the phys any physical differences +and you only you have a measure of + + align:start position:0% +and you only you have a measure of + + + align:start position:0% +and you only you have a measure of +behavior for example how louds crickets + + align:start position:0% +behavior for example how louds crickets + + + align:start position:0% +behavior for example how louds crickets +sing and the ones that sing louder you + + align:start position:0% +sing and the ones that sing louder you + + + align:start position:0% +sing and the ones that sing louder you +can breed those with each other the ones + + align:start position:0% +can breed those with each other the ones + + + align:start position:0% +can breed those with each other the ones +that see uh sing less and at the + + align:start position:0% +that see uh sing less and at the + + + align:start position:0% +that see uh sing less and at the +beginning they're probably all singing + + align:start position:0% +beginning they're probably all singing + + + align:start position:0% +beginning they're probably all singing +but some of them don't sing as loud as + + align:start position:0% +but some of them don't sing as loud as + + + align:start position:0% +but some of them don't sing as loud as +as others and if you keep reading you + + align:start position:0% +as others and if you keep reading you + + + align:start position:0% +as others and if you keep reading you +will eventually end up with a loud + + align:start position:0% +will eventually end up with a loud + + + align:start position:0% +will eventually end up with a loud +singing group and a pretty silent group + + align:start position:0% +singing group and a pretty silent group + + + align:start position:0% +singing group and a pretty silent group +okay it's also been done with fruit + + align:start position:0% +okay it's also been done with fruit + + + align:start position:0% +okay it's also been done with fruit +flies this has been the most common and + + align:start position:0% +flies this has been the most common and + + + align:start position:0% +flies this has been the most common and +probably the most famous experiments + + align:start position:0% +probably the most famous experiments + + + align:start position:0% +probably the most famous experiments +with fruit flies are the production of + + align:start position:0% +with fruit flies are the production of + + + align:start position:0% +with fruit flies are the production of +learning mutants first produced by chip + + align:start position:0% +learning mutants first produced by chip + + + align:start position:0% +learning mutants first produced by chip +Quinn of this department he most of that + + align:start position:0% +Quinn of this department he most of that + + + align:start position:0% +Quinn of this department he most of that +work he did when he was at + + align:start position:0% +work he did when he was at + + + align:start position:0% +work he did when he was at +Princeton and he produced strains of + + align:start position:0% +Princeton and he produced strains of + + + align:start position:0% +Princeton and he produced strains of +fruit + + align:start position:0% +fruit + + + align:start position:0% +fruit +flies that in a particular learning task + + align:start position:0% +flies that in a particular learning task + + + align:start position:0% +flies that in a particular learning task +that he had set up to screen the fruit + + align:start position:0% +that he had set up to screen the fruit + + + align:start position:0% +that he had set up to screen the fruit +flies um that were particularly stupid + + align:start position:0% +flies um that were particularly stupid + + + align:start position:0% +flies um that were particularly stupid +and he named them after vegetables so he + + align:start position:0% +and he named them after vegetables so he + + + align:start position:0% +and he named them after vegetables so he +has rudaba he has turnup and such + + align:start position:0% +has rudaba he has turnup and such + + + align:start position:0% +has rudaba he has turnup and such +individuals and he became well known for + + align:start position:0% +individuals and he became well known for + + + align:start position:0% +individuals and he became well known for +that work the learning mutants and crw + + align:start position:0% +that work the learning mutants and crw + + + align:start position:0% +that work the learning mutants and crw +cl it's also been done + + align:start position:0% +cl it's also been done + + + align:start position:0% +cl it's also been done +uh in mice and in rats in mice they've + + align:start position:0% +uh in mice and in rats in mice they've + + + align:start position:0% +uh in mice and in rats in mice they've +had produce facial learning differences + + align:start position:0% +had produce facial learning differences + + + align:start position:0% +had produce facial learning differences +in different groups and groups that + + align:start position:0% +in different groups and groups that + + + align:start position:0% +in different groups and groups that +different in nest building activity you + + align:start position:0% +different in nest building activity you + + + align:start position:0% +different in nest building activity you +just select the ones that are most + + align:start position:0% +just select the ones that are most + + + align:start position:0% +just select the ones that are most +vigorous about building big nests and + + align:start position:0% +vigorous about building big nests and + + + align:start position:0% +vigorous about building big nests and +the ones that don't build such big nests + + align:start position:0% +the ones that don't build such big nests + + + align:start position:0% +the ones that don't build such big nests +and don't nest in such a vigorous way + + align:start position:0% +and don't nest in such a vigorous way + + + align:start position:0% +and don't nest in such a vigorous way +and you you event if you breed them + + align:start position:0% +and you you event if you breed them + + + align:start position:0% +and you you event if you breed them +selectively for those behavioral traits + + align:start position:0% +selectively for those behavioral traits + + + align:start position:0% +selectively for those behavioral traits +you'll eventually get groups that uh are + + align:start position:0% +you'll eventually get groups that uh are + + + align:start position:0% +you'll eventually get groups that uh are +very very different in the way they + + align:start position:0% +very very different in the way they + + + align:start position:0% +very very different in the way they +build nests and you can do the same + + align:start position:0% +build nests and you can do the same + + + align:start position:0% +build nests and you can do the same +thing for spatial learning problems and + + align:start position:0% +thing for spatial learning problems and + + + align:start position:0% +thing for spatial learning problems and +there the best known is the rad + + align:start position:0% +there the best known is the rad + + + align:start position:0% +there the best known is the rad +experiments where they had what was + + align:start position:0% +experiments where they had what was + + + align:start position:0% +experiments where they had what was +called the HEB Williams + + align:start position:0% +called the HEB Williams + + + align:start position:0% +called the HEB Williams +maze a maze a fairly complex maze that + + align:start position:0% +maze a maze a fairly complex maze that + + + align:start position:0% +maze a maze a fairly complex maze that +they could change easily easily they + + align:start position:0% +they could change easily easily they + + + align:start position:0% +they could change easily easily they +could change the problem so the rat + + align:start position:0% +could change the problem so the rat + + + align:start position:0% +could change the problem so the rat +would be trained on one then they change + + align:start position:0% +would be trained on one then they change + + + align:start position:0% +would be trained on one then they change +the barriers around uh test them again + + align:start position:0% +the barriers around uh test them again + + + align:start position:0% +the barriers around uh test them again +and do that repeatedly and they'd come + + align:start position:0% +and do that repeatedly and they'd come + + + align:start position:0% +and do that repeatedly and they'd come +up with a measure of how intelligent it + + align:start position:0% +up with a measure of how intelligent it + + + align:start position:0% +up with a measure of how intelligent it +was called a rat intelligence test how + + align:start position:0% +was called a rat intelligence test how + + + align:start position:0% +was called a rat intelligence test how +learn how smart are they in learning + + align:start position:0% +learn how smart are they in learning + + + align:start position:0% +learn how smart are they in learning +mazes and of course some of them learn + + align:start position:0% +mazes and of course some of them learn + + + align:start position:0% +mazes and of course some of them learn +much better than others and so again we + + align:start position:0% +much better than others and so again we + + + align:start position:0% +much better than others and so again we +can selectively breathe them for how + + align:start position:0% +can selectively breathe them for how + + + align:start position:0% +can selectively breathe them for how +well they learn the maze we can have the + + align:start position:0% +well they learn the maze we can have the + + + align:start position:0% +well they learn the maze we can have the +ones that learn better we'll interbreed + + align:start position:0% +ones that learn better we'll interbreed + + + align:start position:0% +ones that learn better we'll interbreed +with those the ones that learn more + + align:start position:0% +with those the ones that learn more + + + align:start position:0% +with those the ones that learn more +poorly and you end up with a maze bright + + align:start position:0% +poorly and you end up with a maze bright + + + align:start position:0% +poorly and you end up with a maze bright +maze dull strain and then you cont test + + align:start position:0% +maze dull strain and then you cont test + + + align:start position:0% +maze dull strain and then you cont test +for other differences in you know what + + align:start position:0% +for other differences in you know what + + + align:start position:0% +for other differences in you know what +else happens to us animal what happens + + align:start position:0% +else happens to us animal what happens + + + align:start position:0% +else happens to us animal what happens +in the + + align:start position:0% + + + + align:start position:0% + +brain it was the fruit fly work that led + + align:start position:0% +brain it was the fruit fly work that led + + + align:start position:0% +brain it was the fruit fly work that led +most directly to study to Neuroscience + + align:start position:0% +most directly to study to Neuroscience + + + align:start position:0% +most directly to study to Neuroscience +studies in fact chip after he came here + + align:start position:0% +studies in fact chip after he came here + + + align:start position:0% +studies in fact chip after he came here +eventually did zero in on particular + + align:start position:0% +eventually did zero in on particular + + + align:start position:0% +eventually did zero in on particular +gene or particular uh factor in the + + align:start position:0% +gene or particular uh factor in the + + + align:start position:0% +gene or particular uh factor in the +brain that was found by other groups + + align:start position:0% +brain that was found by other groups + + + align:start position:0% +brain that was found by other groups +also to be involved in + + align:start position:0% +also to be involved in + + + align:start position:0% +also to be involved in +learning okay + + align:start position:0% +learning okay + + + align:start position:0% +learning okay +so and when we deal with humans you the + + align:start position:0% +so and when we deal with humans you the + + + align:start position:0% +so and when we deal with humans you the +best studies probably that + + align:start position:0% +best studies probably that + + + align:start position:0% +best studies probably that +support genetic influences on Behavior + + align:start position:0% +support genetic influences on Behavior + + + align:start position:0% +support genetic influences on Behavior +are the twin + + align:start position:0% +are the twin + + + align:start position:0% +are the twin +studies do you all know know the + + align:start position:0% +studies do you all know know the + + + align:start position:0% +studies do you all know know the +experiments using studying concordance + + align:start position:0% +experiments using studying concordance + + + align:start position:0% +experiments using studying concordance +rates first of all you have to collect + + align:start position:0% +rates first of all you have to collect + + + align:start position:0% +rates first of all you have to collect +large numbers of identical + + align:start position:0% +large numbers of identical + + + align:start position:0% +large numbers of identical +twins uh so that you that you can either + + align:start position:0% +twins uh so that you that you can either + + + align:start position:0% +twins uh so that you that you can either +test them or find out a lot about + + align:start position:0% +test them or find out a lot about + + + align:start position:0% +test them or find out a lot about +them for example do they get become + + align:start position:0% +them for example do they get become + + + align:start position:0% +them for example do they get become +schizophrenic and so that's certainly a + + align:start position:0% +schizophrenic and so that's certainly a + + + align:start position:0% +schizophrenic and so that's certainly a +big behavioral difference the ones that + + align:start position:0% +big behavioral difference the ones that + + + align:start position:0% +big behavioral difference the ones that +become schizophrenic and the that don't + + align:start position:0% +become schizophrenic and the that don't + + + align:start position:0% +become schizophrenic and the that don't +so you find out well if a a a one of the + + align:start position:0% +so you find out well if a a a one of the + + + align:start position:0% +so you find out well if a a a one of the +twins you find out is schizophrenic what + + align:start position:0% +twins you find out is schizophrenic what + + + align:start position:0% +twins you find out is schizophrenic what +is the probability that his twin will + + align:start position:0% +is the probability that his twin will + + + align:start position:0% +is the probability that his twin will +have schizophrenia do you know what the + + align:start position:0% +have schizophrenia do you know what the + + + align:start position:0% +have schizophrenia do you know what the +difference what the probability is it's + + align:start position:0% +difference what the probability is it's + + + align:start position:0% +difference what the probability is it's +about + + align:start position:0% +about + + + align:start position:0% +about +2/3 okay so it's not totally + + align:start position:0% +2/3 okay so it's not totally + + + align:start position:0% +2/3 okay so it's not totally +genetic and it's interesting that that + + align:start position:0% +genetic and it's interesting that that + + + align:start position:0% +genetic and it's interesting that that +2/3 for schizophrenia also applies to + + align:start position:0% +2/3 for schizophrenia also applies to + + + align:start position:0% +2/3 for schizophrenia also applies to +the kind of diabetes I + + align:start position:0% +the kind of diabetes I + + + align:start position:0% +the kind of diabetes I +have if I had a twin brother okay would + + align:start position:0% +have if I had a twin brother okay would + + + align:start position:0% +have if I had a twin brother okay would +have to be a brother because I'd have to + + align:start position:0% +have to be a brother because I'd have to + + + align:start position:0% +have to be a brother because I'd have to +be + + align:start position:0% +be + + + align:start position:0% +be +monozygotic okay the brother would have + + align:start position:0% +monozygotic okay the brother would have + + + align:start position:0% +monozygotic okay the brother would have +a 2third chance of having the same thing + + align:start position:0% +a 2third chance of having the same thing + + + align:start position:0% +a 2third chance of having the same thing +the concordance rate is not + + align:start position:0% +the concordance rate is not + + + align:start position:0% +the concordance rate is not +100% so that that just means there has + + align:start position:0% +100% so that that just means there has + + + align:start position:0% +100% so that that just means there has +to be environmental factors that also + + align:start position:0% +to be environmental factors that also + + + align:start position:0% +to be environmental factors that also +have a strong influence and the degree + + align:start position:0% +have a strong influence and the degree + + + align:start position:0% +have a strong influence and the degree +to which the genetics and environment uh + + align:start position:0% +to which the genetics and environment uh + + + align:start position:0% +to which the genetics and environment uh +play roles can be estimated from this + + align:start position:0% +play roles can be estimated from this + + + align:start position:0% +play roles can be estimated from this +studying concordance + + align:start position:0% +studying concordance + + + align:start position:0% +studying concordance +streats okay and that has been done for + + align:start position:0% +streats okay and that has been done for + + + align:start position:0% +streats okay and that has been done for +a number of different + + align:start position:0% +a number of different + + + align:start position:0% +a number of different +things + + align:start position:0% +things + + + align:start position:0% +things +uh about the selective reading for + + align:start position:0% +uh about the selective reading for + + + align:start position:0% +uh about the selective reading for +Behavioral + + align:start position:0% +Behavioral + + + align:start position:0% +Behavioral +traits um I like many of the examples in + + align:start position:0% +traits um I like many of the examples in + + + align:start position:0% +traits um I like many of the examples in +this book by Temple grandon a very + + align:start position:0% +this book by Temple grandon a very + + + align:start position:0% +this book by Temple grandon a very +interesting lady she's actually I + + align:start position:0% +interesting lady she's actually I + + + align:start position:0% +interesting lady she's actually I +believe to come here to give a talk once + + align:start position:0% +believe to come here to give a talk once + + + align:start position:0% +believe to come here to give a talk once +at least I've heard her I think when I I + + align:start position:0% +at least I've heard her I think when I I + + + align:start position:0% +at least I've heard her I think when I I +heard her she was + + align:start position:0% +heard her she was + + + align:start position:0% +heard her she was +uh promoting one of her books probably + + align:start position:0% +uh promoting one of her books probably + + + align:start position:0% +uh promoting one of her books probably +this one at at the bookstore in Porter + + align:start position:0% +this one at at the bookstore in Porter + + + align:start position:0% +this one at at the bookstore in Porter +Square where they get authors to come + + align:start position:0% +Square where they get authors to come + + + align:start position:0% +Square where they get authors to come +every week and sometimes twice a week to + + align:start position:0% +every week and sometimes twice a week to + + + align:start position:0% +every week and sometimes twice a week to +give talks on their new + + align:start position:0% +give talks on their new + + + align:start position:0% +give talks on their new +books and + + align:start position:0% +books and + + + align:start position:0% +books and +uh I met her she actually signed I had a + + align:start position:0% +uh I met her she actually signed I had a + + + align:start position:0% +uh I met her she actually signed I had a +copy of her book she signed it and uh + + align:start position:0% +copy of her book she signed it and uh + + + align:start position:0% +copy of her book she signed it and uh +talked to me about the teaching I was + + align:start position:0% +talked to me about the teaching I was + + + align:start position:0% +talked to me about the teaching I was +doing at MIT and so forth gave me + + align:start position:0% +doing at MIT and so forth gave me + + + align:start position:0% +doing at MIT and so forth gave me +permission cartlon to use anything in + + align:start position:0% +permission cartlon to use anything in + + + align:start position:0% +permission cartlon to use anything in +her book in class yes okay + + align:start position:0% +her book in class yes okay + + + align:start position:0% +her book in class yes okay +so she points out various things that + + align:start position:0% +so she points out various things that + + + align:start position:0% +so she points out various things that +behavioral traits that dogs have been + + align:start position:0% +behavioral traits that dogs have been + + + align:start position:0% +behavioral traits that dogs have been +bred + + align:start position:0% +bred + + + align:start position:0% +bred +for they've been bred as you know for + + align:start position:0% +for they've been bred as you know for + + + align:start position:0% +for they've been bred as you know for +herting Ability for example the sheep + + align:start position:0% +herting Ability for example the sheep + + + align:start position:0% +herting Ability for example the sheep +dog you know if you want a herge sheet + + align:start position:0% +dog you know if you want a herge sheet + + + align:start position:0% +dog you know if you want a herge sheet +and you you really do need dogs to do it + + align:start position:0% +and you you really do need dogs to do it + + + align:start position:0% +and you you really do need dogs to do it +efficiently you don't want to choose + + align:start position:0% +efficiently you don't want to choose + + + align:start position:0% +efficiently you don't want to choose +just any dog no matter how smarter he is + + align:start position:0% +just any dog no matter how smarter he is + + + align:start position:0% +just any dog no matter how smarter he is +how loyal they are genetically different + + align:start position:0% +how loyal they are genetically different + + + align:start position:0% +how loyal they are genetically different +and they have been bred specifically for + + align:start position:0% +and they have been bred specifically for + + + align:start position:0% +and they have been bred specifically for +hurting so the sheep dog is very very + + align:start position:0% +hurting so the sheep dog is very very + + + align:start position:0% +hurting so the sheep dog is very very +good you're enhancing certain fixed + + align:start position:0% +good you're enhancing certain fixed + + + align:start position:0% +good you're enhancing certain fixed +action patterns and decreasing the + + align:start position:0% +action patterns and decreasing the + + + align:start position:0% +action patterns and decreasing the +influence of other fixed action patterns + + align:start position:0% +influence of other fixed action patterns + + + align:start position:0% +influence of other fixed action patterns +in a way + + align:start position:0% +in a way + + + align:start position:0% +in a way +you're you're enhancing + + align:start position:0% +you're you're enhancing + + + align:start position:0% +you're you're enhancing +stalking uh detecting and stalking + + align:start position:0% +stalking uh detecting and stalking + + + align:start position:0% +stalking uh detecting and stalking +behavior but you're inhibiting the later + + align:start position:0% +behavior but you're inhibiting the later + + + align:start position:0% +behavior but you're inhibiting the later +parts of the predatory behavior they + + align:start position:0% +parts of the predatory behavior they + + + align:start position:0% +parts of the predatory behavior they +never attack the Sheep you've reduced I + + align:start position:0% +never attack the Sheep you've reduced I + + + align:start position:0% +never attack the Sheep you've reduced I +mean this is predatory attack is also + + align:start position:0% +mean this is predatory attack is also + + + align:start position:0% +mean this is predatory attack is also +deter by multiple genes they're M + + align:start position:0% +deter by multiple genes they're M + + + align:start position:0% +deter by multiple genes they're M +multiple + + align:start position:0% +multiple + + + align:start position:0% +multiple +components it's not a single fixed + + align:start position:0% +components it's not a single fixed + + + align:start position:0% +components it's not a single fixed +action pattern really at least on the + + align:start position:0% +action pattern really at least on the + + + align:start position:0% +action pattern really at least on the +motor side then retrievers same kind of + + align:start position:0% +motor side then retrievers same kind of + + + align:start position:0% +motor side then retrievers same kind of +thing some dogs are terrible at + + align:start position:0% +thing some dogs are terrible at + + + align:start position:0% +thing some dogs are terrible at +retrievers but if you get a golden + + align:start position:0% +retrievers but if you get a golden + + + align:start position:0% +retrievers but if you get a golden +retriever or laboratory retriever very + + align:start position:0% +retriever or laboratory retriever very + + + align:start position:0% +retriever or laboratory retriever very +easy because it's part of their genetics + + align:start position:0% +easy because it's part of their genetics + + + align:start position:0% +easy because it's part of their genetics +and of course they're trained for + + align:start position:0% +and of course they're trained for + + + align:start position:0% +and of course they're trained for +hunting uh pointing I remember my father + + align:start position:0% +hunting uh pointing I remember my father + + + align:start position:0% +hunting uh pointing I remember my father +who hunted peasants he had a a pointer + + align:start position:0% +who hunted peasants he had a a pointer + + + align:start position:0% +who hunted peasants he had a a pointer +when I was a little kid you know and + + align:start position:0% +when I was a little kid you know and + + + align:start position:0% +when I was a little kid you know and +I I I still remember that dog you know + + align:start position:0% +I I I still remember that dog you know + + + align:start position:0% +I I I still remember that dog you know +because he was so incredibly not just so + + align:start position:0% +because he was so incredibly not just so + + + align:start position:0% +because he was so incredibly not just so +incredibly loyal to my father and not to + + align:start position:0% +incredibly loyal to my father and not to + + + align:start position:0% +incredibly loyal to my father and not to +his kids uh he was so good at what he + + align:start position:0% +his kids uh he was so good at what he + + + align:start position:0% +his kids uh he was so good at what he +did you know he would stay right at my + + align:start position:0% +did you know he would stay right at my + + + align:start position:0% +did you know he would stay right at my +father's side and he would I mean they + + align:start position:0% +father's side and he would I mean they + + + align:start position:0% +father's side and he would I mean they +used for their incredibly good senses + + align:start position:0% +used for their incredibly good senses + + + align:start position:0% +used for their incredibly good senses +but also for their + + align:start position:0% +but also for their + + + align:start position:0% +but also for their +ability + + align:start position:0% + + + + align:start position:0% + +to detect the Pheasant and then stop and + + align:start position:0% +to detect the Pheasant and then stop and + + + align:start position:0% +to detect the Pheasant and then stop and +withhold their their their tendency to + + align:start position:0% +withhold their their their tendency to + + + align:start position:0% +withhold their their their tendency to +what try to grab it and attack it + + align:start position:0% +what try to grab it and attack it + + + align:start position:0% +what try to grab it and attack it +themselves you know peasants are mostly + + align:start position:0% +themselves you know peasants are mostly + + + align:start position:0% +themselves you know peasants are mostly +on the ground they they can fly to get + + align:start position:0% +on the ground they they can fly to get + + + align:start position:0% +on the ground they they can fly to get +away uh so he would become rigid and go + + align:start position:0% +away uh so he would become rigid and go + + + align:start position:0% +away uh so he would become rigid and go +into this posture it was very obvious + + align:start position:0% +into this posture it was very obvious + + + align:start position:0% +into this posture it was very obvious +and then little signal from my father + + align:start position:0% +and then little signal from my father + + + align:start position:0% +and then little signal from my father +then the dog would rush + + align:start position:0% +then the dog would rush + + + align:start position:0% +then the dog would rush +forward not to try to kill the Pheasant + + align:start position:0% +forward not to try to kill the Pheasant + + + align:start position:0% +forward not to try to kill the Pheasant +but to flush it so he would fly up + + align:start position:0% +but to flush it so he would fly up + + + align:start position:0% +but to flush it so he would fly up +because people that hunt like this + + align:start position:0% +because people that hunt like this + + + align:start position:0% +because people that hunt like this +usually wait if they can't shoot them in + + align:start position:0% +usually wait if they can't shoot them in + + + align:start position:0% +usually wait if they can't shoot them in +the air if they're not good enough shots + + align:start position:0% +the air if they're not good enough shots + + + align:start position:0% +the air if they're not good enough shots +for that then they + + align:start position:0% +for that then they + + + align:start position:0% +for that then they +don't succeed in getting the + + align:start position:0% +don't succeed in getting the + + + align:start position:0% +don't succeed in getting the +Pheasant and I remember the situation + + align:start position:0% +Pheasant and I remember the situation + + + align:start position:0% +Pheasant and I remember the situation +where there were two pheasants full + + align:start position:0% +where there were two pheasants full + + + align:start position:0% +where there were two pheasants full +pulled up and my father had a double + + align:start position:0% +pulled up and my father had a double + + + align:start position:0% +pulled up and my father had a double +barrel shotgun and he got both pheasants + + align:start position:0% +barrel shotgun and he got both pheasants + + + align:start position:0% +barrel shotgun and he got both pheasants +and then another little signal up the + + align:start position:0% +and then another little signal up the + + + align:start position:0% +and then another little signal up the +dog went to retrieve them so he could do + + align:start position:0% +dog went to retrieve them so he could do + + + align:start position:0% +dog went to retrieve them so he could do +both of these things retrieving pointing + + align:start position:0% +both of these things retrieving pointing + + + align:start position:0% +both of these things retrieving pointing +hunting uh and yet many many breeds of + + align:start position:0% +hunting uh and yet many many breeds of + + + align:start position:0% +hunting uh and yet many many breeds of +animals you know you cannot train them + + align:start position:0% +animals you know you cannot train them + + + align:start position:0% +animals you know you cannot train them +in fact they weren't very good with + + align:start position:0% +in fact they weren't very good with + + + align:start position:0% +in fact they weren't very good with +children so as his kids started growing + + align:start position:0% +children so as his kids started growing + + + align:start position:0% +children so as his kids started growing +older uh he got he gave the pointer to a + + align:start position:0% +older uh he got he gave the pointer to a + + + align:start position:0% +older uh he got he gave the pointer to a +farmer who had a lot of + + align:start position:0% +farmer who had a lot of + + + align:start position:0% +farmer who had a lot of +space we were now living in in a + + align:start position:0% +space we were now living in in a + + + align:start position:0% +space we were now living in in a +town when he did that hunting we were + + align:start position:0% +town when he did that hunting we were + + + align:start position:0% +town when he did that hunting we were +still outside of the town but then he + + align:start position:0% +still outside of the town but then he + + + align:start position:0% +still outside of the town but then he +moved into the town so his kids could go + + align:start position:0% +moved into the town so his kids could go + + + align:start position:0% +moved into the town so his kids could go +to school and + + align:start position:0% +to school and + + + align:start position:0% +to school and +uh got a doxent much better family + + align:start position:0% +uh got a doxent much better family + + + align:start position:0% +uh got a doxent much better family +dog okay so that's the dog I became most + + align:start position:0% +dog okay so that's the dog I became most + + + align:start position:0% +dog okay so that's the dog I became most +familiar with as I was growing up farm + + align:start position:0% +familiar with as I was growing up farm + + + align:start position:0% +familiar with as I was growing up farm +animals we know have been bred very + + align:start position:0% +animals we know have been bred very + + + align:start position:0% +animals we know have been bred very +specifically uh not just for their + + align:start position:0% +specifically uh not just for their + + + align:start position:0% +specifically uh not just for their +physical nature but you can't help but + + align:start position:0% +physical nature but you can't help but + + + align:start position:0% +physical nature but you can't help but +when you're breeding quarm animals you + + align:start position:0% +when you're breeding quarm animals you + + + align:start position:0% +when you're breeding quarm animals you +don't you'll tend to choose the the ones + + align:start position:0% +don't you'll tend to choose the the ones + + + align:start position:0% +don't you'll tend to choose the the ones +that aren't as aggressive so aggression + + align:start position:0% +that aren't as aggressive so aggression + + + align:start position:0% +that aren't as aggressive so aggression +has been + + align:start position:0% +has been + + + align:start position:0% +has been +reduced in the cattle for + + align:start position:0% +reduced in the cattle for + + + align:start position:0% +reduced in the cattle for +example + + align:start position:0% +example + + + align:start position:0% +example +uh and the the amount of meat they + + align:start position:0% +uh and the the amount of meat they + + + align:start position:0% +uh and the the amount of meat they +produce has been increased for chickens + + align:start position:0% +produce has been increased for chickens + + + align:start position:0% +produce has been increased for chickens +of course it's egg Ling + + align:start position:0% +of course it's egg Ling + + + align:start position:0% +of course it's egg Ling +ability and that's been + + align:start position:0% +ability and that's been + + + align:start position:0% +ability and that's been +enhanced + + align:start position:0% +enhanced + + + align:start position:0% +enhanced +uh they also breed chickens of course + + align:start position:0% +uh they also breed chickens of course + + + align:start position:0% +uh they also breed chickens of course +for meat um Bulls it's a little + + align:start position:0% +for meat um Bulls it's a little + + + align:start position:0% +for meat um Bulls it's a little +different and you find bulls that are + + align:start position:0% +different and you find bulls that are + + + align:start position:0% +different and you find bulls that are +breeders uh at cattle farms in the US + + align:start position:0% +breeders uh at cattle farms in the US + + + align:start position:0% +breeders uh at cattle farms in the US +where they breed cattle again they + + align:start position:0% +where they breed cattle again they + + + align:start position:0% +where they breed cattle again they +choose bulls that AR they have to limit + + align:start position:0% +choose bulls that AR they have to limit + + + align:start position:0% +choose bulls that AR they have to limit +their aggression but you want big mey + + align:start position:0% +their aggression but you want big mey + + + align:start position:0% +their aggression but you want big mey +bulls because that's what you're trying + + align:start position:0% +bulls because that's what you're trying + + + align:start position:0% +bulls because that's what you're trying +to + + align:start position:0% + + + + align:start position:0% + +breed + + align:start position:0% +breed + + + align:start position:0% +breed +uh my grandfather knew all about this + + align:start position:0% +uh my grandfather knew all about this + + + align:start position:0% +uh my grandfather knew all about this +kind of breeding of the Bulls because I + + align:start position:0% +kind of breeding of the Bulls because I + + + align:start position:0% +kind of breeding of the Bulls because I +remember he wanted to let us see how he + + align:start position:0% +remember he wanted to let us see how he + + + align:start position:0% +remember he wanted to let us see how he +did it and he went in on Horseback and + + align:start position:0% +did it and he went in on Horseback and + + + align:start position:0% +did it and he went in on Horseback and +got a bull and here comes the bull and + + align:start position:0% +got a bull and here comes the bull and + + + align:start position:0% +got a bull and here comes the bull and +we were all right there in the yard Here + + align:start position:0% +we were all right there in the yard Here + + + align:start position:0% +we were all right there in the yard Here +Comes This Charging + + align:start position:0% +Comes This Charging + + + align:start position:0% +Comes This Charging +Bull you can imagine what we felt you + + align:start position:0% +Bull you can imagine what we felt you + + + align:start position:0% +Bull you can imagine what we felt you +know here's his Charging Bull but the + + align:start position:0% +know here's his Charging Bull but the + + + align:start position:0% +know here's his Charging Bull but the +bull well known to my grandfather was + + align:start position:0% +bull well known to my grandfather was + + + align:start position:0% +bull well known to my grandfather was +not interested in kids at all he was + + align:start position:0% +not interested in kids at all he was + + + align:start position:0% +not interested in kids at all he was +only interested in one thing those + + align:start position:0% +only interested in one thing those + + + align:start position:0% +only interested in one thing those +females in the yard so my cousin opened + + align:start position:0% +females in the yard so my cousin opened + + + align:start position:0% +females in the yard so my cousin opened +the gate the bll ran through and + + align:start position:0% +the gate the bll ran through and + + + align:start position:0% +the gate the bll ran through and +immediately began soliciting the + + align:start position:0% +immediately began soliciting the + + + align:start position:0% +immediately began soliciting the +attentions of the + + align:start position:0% +attentions of the + + + align:start position:0% +attentions of the +females okay but of course if you're + + align:start position:0% +females okay but of course if you're + + + align:start position:0% +females okay but of course if you're +using the Bulls for other things like + + align:start position:0% +using the Bulls for other things like + + + align:start position:0% +using the Bulls for other things like +bull fighting then you breed them + + align:start position:0% +bull fighting then you breed them + + + align:start position:0% +bull fighting then you breed them +differently and there are Bull breeders + + align:start position:0% +differently and there are Bull breeders + + + align:start position:0% +differently and there are Bull breeders +in + + align:start position:0% +in + + + align:start position:0% +in +Spain uh that specifically breed bulls + + align:start position:0% +Spain uh that specifically breed bulls + + + align:start position:0% +Spain uh that specifically breed bulls +for their + + align:start position:0% +for their + + + align:start position:0% +for their +ferocity in in bull + + align:start position:0% +ferocity in in bull + + + align:start position:0% +ferocity in in bull +fighting and we know of course we're + + align:start position:0% +fighting and we know of course we're + + + align:start position:0% +fighting and we know of course we're +more familiar with breeding of horses + + align:start position:0% +more familiar with breeding of horses + + + align:start position:0% +more familiar with breeding of horses +and they've bread for various things you + + align:start position:0% +and they've bread for various things you + + + align:start position:0% +and they've bread for various things you +know for speed for thorough + + align:start position:0% +know for speed for thorough + + + align:start position:0% +know for speed for thorough +bread uh for hurting + + align:start position:0% +bread uh for hurting + + + align:start position:0% +bread uh for hurting +cattle the quarter horse they're + + align:start position:0% +cattle the quarter horse they're + + + align:start position:0% +cattle the quarter horse they're +actually faster than thorough bread and + + align:start position:0% +actually faster than thorough bread and + + + align:start position:0% +actually faster than thorough bread and +for a quarter of a mile but they can't + + align:start position:0% +for a quarter of a mile but they can't + + + align:start position:0% +for a quarter of a mile but they can't +keep up with the thorough bread in a + + align:start position:0% +keep up with the thorough bread in a + + + align:start position:0% +keep up with the thorough bread in a +longer + + align:start position:0% +longer + + + align:start position:0% +longer +race + + align:start position:0% +race + + + align:start position:0% +race +uh and uh so there's SE several breeds + + align:start position:0% +uh and uh so there's SE several breeds + + + align:start position:0% +uh and uh so there's SE several breeds +of horses we know that work horses that + + align:start position:0% +of horses we know that work horses that + + + align:start position:0% +of horses we know that work horses that +tend to be bigger meteor stronger but + + align:start position:0% +tend to be bigger meteor stronger but + + + align:start position:0% +tend to be bigger meteor stronger but +slow lower but they're used to pull + + align:start position:0% +slow lower but they're used to pull + + + align:start position:0% +slow lower but they're used to pull +things pull wagons pull plows and so + + align:start position:0% +things pull wagons pull plows and so + + + align:start position:0% +things pull wagons pull plows and so +forth a few of them now but some some of + + align:start position:0% +forth a few of them now but some some of + + + align:start position:0% +forth a few of them now but some some of +them are still maintained so very + + align:start position:0% +them are still maintained so very + + + align:start position:0% +them are still maintained so very +specific breeding for Behavioral + + align:start position:0% +specific breeding for Behavioral + + + align:start position:0% +specific breeding for Behavioral +trays so this question concerns the + + align:start position:0% +trays so this question concerns the + + + align:start position:0% +trays so this question concerns the +problems that often happen when animals + + align:start position:0% +problems that often happen when animals + + + align:start position:0% +problems that often happen when animals +are bred for a single physical trait + + align:start position:0% +are bred for a single physical trait + + + align:start position:0% +are bred for a single physical trait +what happens to + + align:start position:0% +what happens to + + + align:start position:0% +what happens to +them it's common for behavioral problems + + align:start position:0% +them it's common for behavioral problems + + + align:start position:0% +them it's common for behavioral problems +to appear and this is discussed quite a + + align:start position:0% +to appear and this is discussed quite a + + + align:start position:0% +to appear and this is discussed quite a +bit in the Temple grandin's book or the + + align:start position:0% +bit in the Temple grandin's book or the + + + align:start position:0% +bit in the Temple grandin's book or the +example I lik was colli dogs because + + align:start position:0% +example I lik was colli dogs because + + + align:start position:0% +example I lik was colli dogs because +when I was growing up I remember it was + + align:start position:0% +when I was growing up I remember it was + + + align:start position:0% +when I was growing up I remember it was +po the the remember Lassie who I don't + + align:start position:0% +po the the remember Lassie who I don't + + + align:start position:0% +po the the remember Lassie who I don't +know if you even know who Lassie is but + + align:start position:0% +know if you even know who Lassie is but + + + align:start position:0% +know if you even know who Lassie is but +that was a popular dog and Hollywood + + align:start position:0% +that was a popular dog and Hollywood + + + align:start position:0% +that was a popular dog and Hollywood +movies and it was + + align:start position:0% +movies and it was + + + align:start position:0% +movies and it was +Lassie grew up before this intense + + align:start position:0% +Lassie grew up before this intense + + + align:start position:0% +Lassie grew up before this intense +breeding in this period started to + + align:start position:0% +breeding in this period started to + + + align:start position:0% +breeding in this period started to +change the appearance of Coles to make + + align:start position:0% +change the appearance of Coles to make + + + align:start position:0% +change the appearance of Coles to make +them have narrower and narrower skulls + + align:start position:0% +them have narrower and narrower skulls + + + align:start position:0% +them have narrower and narrower skulls +emphasize the needle nose so she said + + align:start position:0% +emphasize the needle nose so she said + + + align:start position:0% +emphasize the needle nose so she said +the result was brainless ice + + align:start position:0% +the result was brainless ice + + + align:start position:0% +the result was brainless ice +picks not like lassia at + + align:start position:0% +picks not like lassia at + + + align:start position:0% +picks not like lassia at +all and that's the danger if you just + + align:start position:0% +all and that's the danger if you just + + + align:start position:0% +all and that's the danger if you just +ignore behavior when you're breeding for + + align:start position:0% +ignore behavior when you're breeding for + + + align:start position:0% +ignore behavior when you're breeding for +a particular physical trait and this is + + align:start position:0% +a particular physical trait and this is + + + align:start position:0% +a particular physical trait and this is +not the only example uh breeds of dogs + + align:start position:0% +not the only example uh breeds of dogs + + + align:start position:0% +not the only example uh breeds of dogs +you know have particular problems + + align:start position:0% +you know have particular problems + + + align:start position:0% +you know have particular problems +usually it's that they get certain + + align:start position:0% +usually it's that they get certain + + + align:start position:0% +usually it's that they get certain +diseases or or coer spaniels for example + + align:start position:0% +diseases or or coer spaniels for example + + + align:start position:0% +diseases or or coer spaniels for example +many of them get type of epilepsy you + + align:start position:0% +many of them get type of epilepsy you + + + align:start position:0% +many of them get type of epilepsy you +know that's certainly a major behavioral + + align:start position:0% +know that's certainly a major behavioral + + + align:start position:0% +know that's certainly a major behavioral +problem U behavioral disease that they + + align:start position:0% +problem U behavioral disease that they + + + align:start position:0% +problem U behavioral disease that they +get because of this breeding for their + + align:start position:0% + + + + align:start position:0% + +appearance so is it true that no genes + + align:start position:0% +appearance so is it true that no genes + + + align:start position:0% +appearance so is it true that no genes +for human behavior have been + + align:start position:0% + + + + align:start position:0% + +found the argument was that we can + + align:start position:0% +found the argument was that we can + + + align:start position:0% +found the argument was that we can +dispense with the direct evidence for a + + align:start position:0% +dispense with the direct evidence for a + + + align:start position:0% +dispense with the direct evidence for a +genetic basis of human social forms in a + + align:start position:0% +genetic basis of human social forms in a + + + align:start position:0% +genetic basis of human social forms in a +single word no + + align:start position:0% +single word no + + + align:start position:0% +single word no +evidence and here's another quote from + + align:start position:0% +evidence and here's another quote from + + + align:start position:0% +evidence and here's another quote from +this book called not in our Jeans by the + + align:start position:0% +this book called not in our Jeans by the + + + align:start position:0% +this book called not in our Jeans by the +Harvard Professor + + align:start position:0% +Harvard Professor + + + align:start position:0% +Harvard Professor +lanon Rose a British professor in cing I + + align:start position:0% +lanon Rose a British professor in cing I + + + align:start position:0% +lanon Rose a British professor in cing I +don't remember where he's + + align:start position:0% +don't remember where he's + + + align:start position:0% +don't remember where he's +from he said no one has ever been able + + align:start position:0% +from he said no one has ever been able + + + align:start position:0% +from he said no one has ever been able +to relate any aspect of human social + + align:start position:0% +to relate any aspect of human social + + + align:start position:0% +to relate any aspect of human social +behavior to any particular gene or set + + align:start position:0% +behavior to any particular gene or set + + + align:start position:0% +behavior to any particular gene or set +of Dreams is that true still I don't + + align:start position:0% +of Dreams is that true still I don't + + + align:start position:0% +of Dreams is that true still I don't +think so uh first of all in your book + + align:start position:0% +think so uh first of all in your book + + + align:start position:0% +think so uh first of all in your book +there Alcock just points out the absence + + align:start position:0% +there Alcock just points out the absence + + + align:start position:0% +there Alcock just points out the absence +of evidence isn't really evidence of + + align:start position:0% +of evidence isn't really evidence of + + + align:start position:0% +of evidence isn't really evidence of +absent of non-involvement of genes and + + align:start position:0% +absent of non-involvement of genes and + + + align:start position:0% +absent of non-involvement of genes and +soical + + align:start position:0% +soical + + + align:start position:0% +soical +development uh I guess it seemed to him + + align:start position:0% +development uh I guess it seemed to him + + + align:start position:0% +development uh I guess it seemed to him +that way and that was the argument he + + align:start position:0% +that way and that was the argument he + + + align:start position:0% +that way and that was the argument he +made but I would point out more recent + + align:start position:0% +made but I would point out more recent + + + align:start position:0% +made but I would point out more recent +evidence for specific + + align:start position:0% +evidence for specific + + + align:start position:0% +evidence for specific +genes + + align:start position:0% +genes + + + align:start position:0% +genes +uh we say for a social + + align:start position:0% +uh we say for a social + + + align:start position:0% +uh we say for a social +behavior but I want you to keep in mind + + align:start position:0% +behavior but I want you to keep in mind + + + align:start position:0% +behavior but I want you to keep in mind +that even though specific genes are + + align:start position:0% +that even though specific genes are + + + align:start position:0% +that even though specific genes are +being found are correlated with with + + align:start position:0% +being found are correlated with with + + + align:start position:0% +being found are correlated with with +various social behaviors and especially + + align:start position:0% +various social behaviors and especially + + + align:start position:0% +various social behaviors and especially +behavioral problems they're + + align:start position:0% +behavioral problems they're + + + align:start position:0% +behavioral problems they're +not genes code for + + align:start position:0% +not genes code for + + + align:start position:0% +not genes code for +proteins okay and if we look at these + + align:start position:0% +proteins okay and if we look at these + + + align:start position:0% +proteins okay and if we look at these +behaviors these abnormalities in humans + + align:start position:0% +behaviors these abnormalities in humans + + + align:start position:0% +behaviors these abnormalities in humans +autism schizophrenia and other mental + + align:start position:0% +autism schizophrenia and other mental + + + align:start position:0% +autism schizophrenia and other mental +diseases attention deficit hyperactivity + + align:start position:0% +diseases attention deficit hyperactivity + + + align:start position:0% +diseases attention deficit hyperactivity +disorder yes there's genetic + + align:start position:0% +disorder yes there's genetic + + + align:start position:0% +disorder yes there's genetic +contribution to all of these there's + + align:start position:0% +contribution to all of these there's + + + align:start position:0% +contribution to all of these there's +always multiple genes involved + + align:start position:0% +always multiple genes involved + + + align:start position:0% +always multiple genes involved +environmental effects are still + + align:start position:0% +environmental effects are still + + + align:start position:0% +environmental effects are still +strong + + align:start position:0% +strong + + + align:start position:0% +strong +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so how could a gene that has what + + align:start position:0% +so how could a gene that has what + + + align:start position:0% +so how could a gene that has what +appears to be maladaptive consequences + + align:start position:0% +appears to be maladaptive consequences + + + align:start position:0% +appears to be maladaptive consequences +be present in some animals or people + + align:start position:0% +be present in some animals or people + + + align:start position:0% +be present in some animals or people +today why wasn't it + + align:start position:0% +today why wasn't it + + + align:start position:0% +today why wasn't it +lost but the first thing I asked when I + + align:start position:0% +lost but the first thing I asked when I + + + align:start position:0% +lost but the first thing I asked when I +got diabetes at age 24 know what's this + + align:start position:0% +got diabetes at age 24 know what's this + + + align:start position:0% +got diabetes at age 24 know what's this +Dean doing around could have + + align:start position:0% +Dean doing around could have + + + align:start position:0% +Dean doing around could have +disappeared a thousand years + + align:start position:0% +disappeared a thousand years + + + align:start position:0% +disappeared a thousand years +ago first of all it could be a recent + + align:start position:0% +ago first of all it could be a recent + + + align:start position:0% +ago first of all it could be a recent +mutation and well be + + align:start position:0% +mutation and well be + + + align:start position:0% +mutation and well be +lost or maybe it has its bad effects + + align:start position:0% +lost or maybe it has its bad effects + + + align:start position:0% +lost or maybe it has its bad effects +after + + align:start position:0% +after + + + align:start position:0% +after +reproduction I said I got it at age + + align:start position:0% +reproduction I said I got it at age + + + align:start position:0% +reproduction I said I got it at age +24 you + + align:start position:0% +24 you + + + align:start position:0% +24 you +know during the age of + + align:start position:0% +know during the age of + + + align:start position:0% +know during the age of +reproduction many effects do occur later + + align:start position:0% +reproduction many effects do occur later + + + align:start position:0% +reproduction many effects do occur later +uh it may have effects only in certain + + align:start position:0% +uh it may have effects only in certain + + + align:start position:0% +uh it may have effects only in certain +environments if I were in an environment + + align:start position:0% +environments if I were in an environment + + + align:start position:0% +environments if I were in an environment +I wasn't exposed to same viruses I may + + align:start position:0% +I wasn't exposed to same viruses I may + + + align:start position:0% +I wasn't exposed to same viruses I may +never have gotten it it's an autoimmune + + align:start position:0% +never have gotten it it's an autoimmune + + + align:start position:0% +never have gotten it it's an autoimmune +disease triggered by + + align:start position:0% +disease triggered by + + + align:start position:0% +disease triggered by +viruses it's also of course because of + + align:start position:0% +viruses it's also of course because of + + + align:start position:0% +viruses it's also of course because of +modern Medical Treatments but it's also + + align:start position:0% +modern Medical Treatments but it's also + + + align:start position:0% +modern Medical Treatments but it's also +remember genetic swamping if you've + + align:start position:0% +remember genetic swamping if you've + + + align:start position:0% +remember genetic swamping if you've +forgotten what that is go back and read + + align:start position:0% +forgotten what that is go back and read + + + align:start position:0% +forgotten what that is go back and read +it it was in my notes and you can find + + align:start position:0% +it it was in my notes and you can find + + + align:start position:0% +it it was in my notes and you can find +it also on the web and then I'm posting + + align:start position:0% +it also on the web and then I'm posting + + + align:start position:0% +it also on the web and then I'm posting +these homework questions it's already at + + align:start position:0% +these homework questions it's already at + + + align:start position:0% +these homework questions it's already at +the end of the class here but I am + + align:start position:0% +the end of the class here but I am + + + align:start position:0% +the end of the class here but I am +willing to give you I want you to spend + + align:start position:0% +willing to give you I want you to spend + + + align:start position:0% +willing to give you I want you to spend +most of the time on this one the other + + align:start position:0% +most of the time on this one the other + + + align:start position:0% +most of the time on this one the other +should be easier for you if you have + + align:start position:0% +should be easier for you if you have + + + align:start position:0% +should be easier for you if you have +trouble with those I'm happy to give you + + align:start position:0% +trouble with those I'm happy to give you + + + align:start position:0% +trouble with those I'm happy to give you +hints I'm asking you to do these or + + align:start position:0% +hints I'm asking you to do these or + + + align:start position:0% +hints I'm asking you to do these or +similar to homework I gave last year + + align:start position:0% +similar to homework I gave last year + + + align:start position:0% +similar to homework I gave last year +because I want you to think think about + + align:start position:0% +because I want you to think think about + + + align:start position:0% +because I want you to think think about +these things and be clear about the type + + align:start position:0% +these things and be clear about the type + + + align:start position:0% +these things and be clear about the type +of thinking you need to do and this is + + align:start position:0% +of thinking you need to do and this is + + + align:start position:0% +of thinking you need to do and this is +the one that causes the most controversy + + align:start position:0% +the one that causes the most controversy + + + align:start position:0% +the one that causes the most controversy +so think about that and you can ask me + + align:start position:0% +so think about that and you can ask me + + + align:start position:0% +so think about that and you can ask me +about it on Friday if you wish and I'm + + align:start position:0% +about it on Friday if you wish and I'm + + + align:start position:0% +about it on Friday if you wish and I'm +happy to give you some suggestions \ No newline at end of file diff --git a/9lc7mxULRF0.txt b/9lc7mxULRF0.txt new file mode 100644 index 0000000000000000000000000000000000000000..26585631d101b50f11ddc589d309773088be2bff --- /dev/null +++ b/9lc7mxULRF0.txt @@ -0,0 +1,1995 @@ +align:start position:0% + +the molecules and born-oppenheimer hilar + + align:start position:0% +the molecules and born-oppenheimer hilar + + + align:start position:0% +the molecules and born-oppenheimer hilar +approximation + + align:start position:0% + + + + align:start position:0% + +okay oh we all know that molecules are a + + align:start position:0% +okay oh we all know that molecules are a + + + align:start position:0% +okay oh we all know that molecules are a +lot harder to solve than atoms and even + + align:start position:0% +lot harder to solve than atoms and even + + + align:start position:0% +lot harder to solve than atoms and even +atoms are not that easy once you have + + align:start position:0% +atoms are not that easy once you have + + + align:start position:0% +atoms are not that easy once you have +more than one electron because of the + + align:start position:0% +more than one electron because of the + + + align:start position:0% +more than one electron because of the +electrostatic repulsion but the + + align:start position:0% +electrostatic repulsion but the + + + align:start position:0% +electrostatic repulsion but the +molecules are significantly different in + + align:start position:0% +molecules are significantly different in + + + align:start position:0% +molecules are significantly different in +that one of the greatest simplicity's + + align:start position:0% +that one of the greatest simplicity's + + + align:start position:0% +that one of the greatest simplicity's +that we had with atoms is that the atom + + align:start position:0% +that we had with atoms is that the atom + + + align:start position:0% +that we had with atoms is that the atom +is such at the potential created by the + + align:start position:0% +is such at the potential created by the + + + align:start position:0% +is such at the potential created by the +nucleus is fairly symmetric when you + + align:start position:0% +nucleus is fairly symmetric when you + + + align:start position:0% +nucleus is fairly symmetric when you +have a molecule you have separate nuclei + + align:start position:0% +have a molecule you have separate nuclei + + + align:start position:0% +have a molecule you have separate nuclei +and therefore your spherical symmetry is + + align:start position:0% +and therefore your spherical symmetry is + + + align:start position:0% +and therefore your spherical symmetry is +gone and whether you have one electron + + align:start position:0% +gone and whether you have one electron + + + align:start position:0% +gone and whether you have one electron +or more than one electron there's no + + align:start position:0% +or more than one electron there's no + + + align:start position:0% +or more than one electron there's no +spherical symmetry all our tools of + + align:start position:0% +spherical symmetry all our tools of + + + align:start position:0% +spherical symmetry all our tools of +angular momentum don't help us much we + + align:start position:0% +angular momentum don't help us much we + + + align:start position:0% +angular momentum don't help us much we +have to start the problem and new so the + + align:start position:0% +have to start the problem and new so the + + + align:start position:0% +have to start the problem and new so the +difficulty with molecules is basically + + align:start position:0% +difficulty with molecules is basically + + + align:start position:0% +difficulty with molecules is basically +that the potential for the electrons + + align:start position:0% +that the potential for the electrons + + + align:start position:0% +that the potential for the electrons +where they move is not spherically + + align:start position:0% +where they move is not spherically + + + align:start position:0% +where they move is not spherically +symmetric there's another thing that + + align:start position:0% +symmetric there's another thing that + + + align:start position:0% +symmetric there's another thing that +helps us however is that there's a nice + + align:start position:0% +helps us however is that there's a nice + + + align:start position:0% +helps us however is that there's a nice +separation of mass scales you have the + + align:start position:0% +separation of mass scales you have the + + + align:start position:0% +separation of mass scales you have the +mass little m of the electron and the + + align:start position:0% +mass little m of the electron and the + + + align:start position:0% +mass little m of the electron and the +nuclear mass this could be the mass of + + align:start position:0% +nuclear mass this could be the mass of + + + align:start position:0% +nuclear mass this could be the mass of +one nucleus or a mass of a few nuclei or + + align:start position:0% +one nucleus or a mass of a few nuclei or + + + align:start position:0% +one nucleus or a mass of a few nuclei or +doesn't matter but this is small and + + align:start position:0% +doesn't matter but this is small and + + + align:start position:0% +doesn't matter but this is small and +typically 10 to the minus 4 you know an + + align:start position:0% +typically 10 to the minus 4 you know an + + + align:start position:0% +typically 10 to the minus 4 you know an +electron is about 2,000 times lighter + + align:start position:0% +electron is about 2,000 times lighter + + + align:start position:0% +electron is about 2,000 times lighter +than a single proton if you already have + + align:start position:0% +than a single proton if you already have + + + align:start position:0% +than a single proton if you already have +a nice nucleus with a couple of them + + align:start position:0% +a nice nucleus with a couple of them + + + align:start position:0% +a nice nucleus with a couple of them +you're several thousands already there + + align:start position:0% +you're several thousands already there + + + align:start position:0% +you're several thousands already there +so this is a nice number so we want to + + align:start position:0% +so this is a nice number so we want to + + + align:start position:0% +so this is a nice number so we want to +understand the scales of the physics of + + align:start position:0% +understand the scales of the physics of + + + align:start position:0% +understand the scales of the physics of +this so let's assume we have a molecule + + align:start position:0% +this so let's assume we have a molecule + + + align:start position:0% +this so let's assume we have a molecule +maybe has a few centers and then there's + + align:start position:0% +maybe has a few centers and then there's + + + align:start position:0% +maybe has a few centers and then there's +electronic cloud and it has a size of + + align:start position:0% +electronic cloud and it has a size of + + + align:start position:0% +electronic cloud and it has a size of +the order of a so we can estimate at + + align:start position:0% +the order of a so we can estimate at + + + align:start position:0% +the order of a so we can estimate at +first sight what are the energies + + align:start position:0% +first sight what are the energies + + + align:start position:0% +first sight what are the energies +involved here what is the energy of the + + align:start position:0% +involved here what is the energy of the + + + align:start position:0% +involved here what is the energy of the +electron for example and you could say + + align:start position:0% +electron for example and you could say + + + align:start position:0% +electron for example and you could say +the momentum of the electron is of the + + align:start position:0% +the momentum of the electron is of the + + + align:start position:0% +the momentum of the electron is of the +order of H bar times the size of the + + align:start position:0% +order of H bar times the size of the + + + align:start position:0% +order of H bar times the size of the +cloud it's an estimate and the energies + + align:start position:0% +cloud it's an estimate and the energies + + + align:start position:0% +cloud it's an estimate and the energies +electron energies are basically + + align:start position:0% +electron energies are basically + + + align:start position:0% +electron energies are basically +determined by the size in which they are + + align:start position:0% +determined by the size in which they are + + + align:start position:0% +determined by the size in which they are +confined which is a H bar and the mass + + align:start position:0% +confined which is a H bar and the mass + + + align:start position:0% +confined which is a H bar and the mass +of the electron those are the electronic + + align:start position:0% +of the electron those are the electronic + + + align:start position:0% +of the electron those are the electronic +energy so H squared over m a squared + + align:start position:0% +energy so H squared over m a squared + + + align:start position:0% +energy so H squared over m a squared +those are the right units is P squared + + align:start position:0% +those are the right units is P squared + + + align:start position:0% +those are the right units is P squared +over m the unit so it's natural like + + align:start position:0% +over m the unit so it's natural like + + + align:start position:0% +over m the unit so it's natural like +this so this is the electronic + + align:start position:0% +this so this is the electronic + + + align:start position:0% +this so this is the electronic +configuration and typical electronic + + align:start position:0% +configuration and typical electronic + + + align:start position:0% +configuration and typical electronic +energy so what is the approximate + + align:start position:0% +energy so what is the approximate + + + align:start position:0% +energy so what is the approximate +picture of the physics of a molecule + + align:start position:0% +picture of the physics of a molecule + + + align:start position:0% +picture of the physics of a molecule +basically you have nuclei and the nuclei + + align:start position:0% +basically you have nuclei and the nuclei + + + align:start position:0% +basically you have nuclei and the nuclei +repel each other they want to be away + + align:start position:0% +repel each other they want to be away + + + align:start position:0% +repel each other they want to be away +now the electrons come in and then they + + align:start position:0% +now the electrons come in and then they + + + align:start position:0% +now the electrons come in and then they +fly around the nuclei and the electrons + + align:start position:0% +fly around the nuclei and the electrons + + + align:start position:0% +fly around the nuclei and the electrons +attract the nuclei and attract the + + align:start position:0% +attract the nuclei and attract the + + + align:start position:0% +attract the nuclei and attract the +nuclei so the electrons reasonably place + + align:start position:0% +nuclei so the electrons reasonably place + + + align:start position:0% +nuclei so the electrons reasonably place +compensate the repulsion of the nuclei + + align:start position:0% +compensate the repulsion of the nuclei + + + align:start position:0% +compensate the repulsion of the nuclei +by creating some new attraction at the + + align:start position:0% +by creating some new attraction at the + + + align:start position:0% +by creating some new attraction at the +end you get some kind of equilibrium is + + align:start position:0% +end you get some kind of equilibrium is + + + align:start position:0% +end you get some kind of equilibrium is +not classical because you cannot + + align:start position:0% +not classical because you cannot + + + align:start position:0% +not classical because you cannot +it's stable equilibrium between + + align:start position:0% +it's stable equilibrium between + + + align:start position:0% +it's stable equilibrium between +classical particles this is one of the + + align:start position:0% +classical particles this is one of the + + + align:start position:0% +classical particles this is one of the +amazing things about quantum mechanics + + align:start position:0% +amazing things about quantum mechanics + + + align:start position:0% +amazing things about quantum mechanics +you know very well an atom would not + + align:start position:0% +you know very well an atom would not + + + align:start position:0% +you know very well an atom would not +exist without quantum mechanics you + + align:start position:0% +exist without quantum mechanics you + + + align:start position:0% +exist without quantum mechanics you +would have stable classical orbit + + align:start position:0% +would have stable classical orbit + + + align:start position:0% +would have stable classical orbit +circular orbits but they radiate energy + + align:start position:0% +circular orbits but they radiate energy + + + align:start position:0% +circular orbits but they radiate energy +so they indicate if you have a molecule + + align:start position:0% +so they indicate if you have a molecule + + + align:start position:0% +so they indicate if you have a molecule +you have two repelling charge positive + + align:start position:0% +you have two repelling charge positive + + + align:start position:0% +you have two repelling charge positive +charged particles in E&M you saw the + + align:start position:0% +charged particles in E&M you saw the + + + align:start position:0% +charged particles in E&M you saw the +case when you put a negative charge in + + align:start position:0% +case when you put a negative charge in + + + align:start position:0% +case when you put a negative charge in +the middle and you create a Calibri 'm + + align:start position:0% +the middle and you create a Calibri 'm + + + align:start position:0% +the middle and you create a Calibri 'm +but that's absolutely unstable you move + + align:start position:0% +but that's absolutely unstable you move + + + align:start position:0% +but that's absolutely unstable you move +that electric charge a middle a micron + + align:start position:0% +that electric charge a middle a micron + + + align:start position:0% +that electric charge a middle a micron +and then off it goes the whole thing is + + align:start position:0% +and then off it goes the whole thing is + + + align:start position:0% +and then off it goes the whole thing is +unstable but quantum mechanics of those + + align:start position:0% +unstable but quantum mechanics of those + + + align:start position:0% +unstable but quantum mechanics of those +problems and and our physical picture is + + align:start position:0% +problems and and our physical picture is + + + align:start position:0% +problems and and our physical picture is +that of repelling nuclei an attracting + + align:start position:0% +that of repelling nuclei an attracting + + + align:start position:0% +that of repelling nuclei an attracting +cloud of electric rate in an equilibrium + + align:start position:0% +cloud of electric rate in an equilibrium + + + align:start position:0% +cloud of electric rate in an equilibrium +in which the nuclei reasonably well + + align:start position:0% +in which the nuclei reasonably well + + + align:start position:0% +in which the nuclei reasonably well +localized they are quantum particles but + + align:start position:0% +localized they are quantum particles but + + + align:start position:0% +localized they are quantum particles but +they're reasonably well localized where + + align:start position:0% +they're reasonably well localized where + + + align:start position:0% +they're reasonably well localized where +the electrons are completely delocalized + + align:start position:0% +the electrons are completely delocalized + + + align:start position:0% +the electrons are completely delocalized +that is our picture they are moving in + + align:start position:0% +that is our picture they are moving in + + + align:start position:0% +that is our picture they are moving in +that way so our picture will be we have + + align:start position:0% +that way so our picture will be we have + + + align:start position:0% +that way so our picture will be we have +that and we'll have slow vibrations of + + align:start position:0% +that and we'll have slow vibrations of + + + align:start position:0% +that and we'll have slow vibrations of +the nuclei that are mostly localized and + + align:start position:0% +the nuclei that are mostly localized and + + + align:start position:0% +the nuclei that are mostly localized and +you can imagine calculating the + + align:start position:0% +you can imagine calculating the + + + align:start position:0% +you can imagine calculating the +electronic configuration for any + + align:start position:0% +electronic configuration for any + + + align:start position:0% +electronic configuration for any +particular separation of the nuclei and + + align:start position:0% +particular separation of the nuclei and + + + align:start position:0% +particular separation of the nuclei and +that's the cloud for this separation as + + align:start position:0% +that's the cloud for this separation as + + + align:start position:0% +that's the cloud for this separation as +the nuclei vibrate the electronic + + align:start position:0% +the nuclei vibrate the electronic + + + align:start position:0% +the nuclei vibrate the electronic +configuration probably adjusts + + align:start position:0% +configuration probably adjusts + + + align:start position:0% +configuration probably adjusts +adiabatically to this thing in the + + align:start position:0% +adiabatically to this thing in the + + + align:start position:0% +adiabatically to this thing in the +instantaneous eigenstates and they work + + align:start position:0% +instantaneous eigenstates and they work + + + align:start position:0% +instantaneous eigenstates and they work +that way we're going to do that + + align:start position:0% +that way we're going to do that + + + align:start position:0% +that way we're going to do that +in trying to understand things they also + + align:start position:0% +in trying to understand things they also + + + align:start position:0% +in trying to understand things they also +want to emphasize this kind of + + align:start position:0% +want to emphasize this kind of + + + align:start position:0% +want to emphasize this kind of +remarkable property of an elect + + align:start position:0% +remarkable property of an elect + + + align:start position:0% +remarkable property of an elect +turn to create the bound state so we are + + align:start position:0% +turn to create the bound state so we are + + + align:start position:0% +turn to create the bound state so we are +not amazed on the fact that if you have + + align:start position:0% +not amazed on the fact that if you have + + + align:start position:0% +not amazed on the fact that if you have +a proton and we can have an electron + + align:start position:0% +a proton and we can have an electron + + + align:start position:0% +a proton and we can have an electron +here we create a bound state and that's + + align:start position:0% +here we create a bound state and that's + + + align:start position:0% +here we create a bound state and that's +a hydrogen atom but suppose I bring in + + align:start position:0% +a hydrogen atom but suppose I bring in + + + align:start position:0% +a hydrogen atom but suppose I bring in +another proton from infinity + + align:start position:0% +another proton from infinity + + + align:start position:0% +another proton from infinity +well I if I bring it I'm gonna start + + align:start position:0% +well I if I bring it I'm gonna start + + + align:start position:0% +well I if I bring it I'm gonna start +bringing it here this kind of it's + + align:start position:0% +bringing it here this kind of it's + + + align:start position:0% +bringing it here this kind of it's +neutral but eventually this proton is + + align:start position:0% +neutral but eventually this proton is + + + align:start position:0% +neutral but eventually this proton is +going to polarize this thing okay I'm + + align:start position:0% +going to polarize this thing okay I'm + + + align:start position:0% +going to polarize this thing okay I'm +going to bring it and then if I come too + + align:start position:0% +going to bring it and then if I come too + + + align:start position:0% +going to bring it and then if I come too +close it repels it so there will be a + + align:start position:0% +close it repels it so there will be a + + + align:start position:0% +close it repels it so there will be a +force repelling it and we have to figure + + align:start position:0% +force repelling it and we have to figure + + + align:start position:0% +force repelling it and we have to figure +out what it does suppose I try to bring + + align:start position:0% +out what it does suppose I try to bring + + + align:start position:0% +out what it does suppose I try to bring +it in do you think that an electron is + + align:start position:0% +it in do you think that an electron is + + + align:start position:0% +it in do you think that an electron is +capable of stabilizing two protons can + + align:start position:0% +capable of stabilizing two protons can + + + align:start position:0% +capable of stabilizing two protons can +they create a cloud in which an electron + + align:start position:0% +they create a cloud in which an electron + + + align:start position:0% +they create a cloud in which an electron +stabilizes the two protons is that + + align:start position:0% +stabilizes the two protons is that + + + align:start position:0% +stabilizes the two protons is that +possible or not possible this a lot of + + align:start position:0% +possible or not possible this a lot of + + + align:start position:0% +possible or not possible this a lot of +protons for one single electron is that + + align:start position:0% +protons for one single electron is that + + + align:start position:0% +protons for one single electron is that +possible or not variety say yes yes any + + align:start position:0% +possible or not variety say yes yes any + + + align:start position:0% +possible or not variety say yes yes any +other opinions + + align:start position:0% + + + + align:start position:0% + +can that happen can the electron produce + + align:start position:0% +can that happen can the electron produce + + + align:start position:0% +can that happen can the electron produce +a bound state of two protons exactly + + align:start position:0% +a bound state of two protons exactly + + + align:start position:0% +a bound state of two protons exactly +sorry it is were + + align:start position:0% + + + + align:start position:0% + +okay yes it can produce it and this + + align:start position:0% +okay yes it can produce it and this + + + align:start position:0% +okay yes it can produce it and this +would be called with an electron here + + align:start position:0% +would be called with an electron here + + + align:start position:0% +would be called with an electron here +the hydrogen molecule ion so h2 plus is + + align:start position:0% +the hydrogen molecule ion so h2 plus is + + + align:start position:0% +the hydrogen molecule ion so h2 plus is +a hydrogen molecule that had these two + + align:start position:0% +a hydrogen molecule that had these two + + + align:start position:0% +a hydrogen molecule that had these two +things and it lost one electron and yes + + align:start position:0% +things and it lost one electron and yes + + + align:start position:0% +things and it lost one electron and yes +this can be done and we'll analyze it + + align:start position:0% +this can be done and we'll analyze it + + + align:start position:0% +this can be done and we'll analyze it +and now you can get greedy and say can + + align:start position:0% +and now you can get greedy and say can + + + align:start position:0% +and now you can get greedy and say can +you get an electron to stabilize three + + align:start position:0% +you get an electron to stabilize three + + + align:start position:0% +you get an electron to stabilize three +protons yes or no no cannot get it it's + + align:start position:0% +protons yes or no no cannot get it it's + + + align:start position:0% +protons yes or no no cannot get it it's +just too much work for an electron it + + align:start position:0% +just too much work for an electron it + + + align:start position:0% +just too much work for an electron it +cannot do it there theorems like that + + align:start position:0% +cannot do it there theorems like that + + + align:start position:0% +cannot do it there theorems like that +Eliot liebe mathematical physicist has + + align:start position:0% +Eliot liebe mathematical physicist has + + + align:start position:0% +Eliot liebe mathematical physicist has +proven all kinds of this things and we + + align:start position:0% +proven all kinds of this things and we + + + align:start position:0% +proven all kinds of this things and we +might discuss some of that in the Homer + + align:start position:0% +might discuss some of that in the Homer + + + align:start position:0% +might discuss some of that in the Homer +is kind of nice stuff so we will be + + align:start position:0% +is kind of nice stuff so we will be + + + align:start position:0% +is kind of nice stuff so we will be +looking at the physics of those things + + align:start position:0% +looking at the physics of those things + + + align:start position:0% +looking at the physics of those things +with a little detail so now of let's go + + align:start position:0% +with a little detail so now of let's go + + + align:start position:0% +with a little detail so now of let's go +back to our molecule here and estimate + + align:start position:0% + + + + align:start position:0% + +the vibrational nuclear energy so we + + align:start position:0% +the vibrational nuclear energy so we + + + align:start position:0% +the vibrational nuclear energy so we +have this picture the electrons are + + align:start position:0% +have this picture the electrons are + + + align:start position:0% +have this picture the electrons are +there the nuclei are kind of + + align:start position:0% +there the nuclei are kind of + + + align:start position:0% +there the nuclei are kind of +semi-classical they are roughly + + align:start position:0% +semi-classical they are roughly + + + align:start position:0% +semi-classical they are roughly +localized and they're varying and how + + align:start position:0% +localized and they're varying and how + + + align:start position:0% +localized and they're varying and how +would we estimate the nuclear vibration + + align:start position:0% +would we estimate the nuclear vibration + + + align:start position:0% +would we estimate the nuclear vibration +frequency so estimate nuclear vibration + + align:start position:0% +frequency so estimate nuclear vibration + + + align:start position:0% +frequency so estimate nuclear vibration +so we think of a harmonic oscillator P + + align:start position:0% +so we think of a harmonic oscillator P + + + align:start position:0% +so we think of a harmonic oscillator P +squared over two mass of the nucleons + + align:start position:0% +squared over two mass of the nucleons + + + align:start position:0% +squared over two mass of the nucleons +plus a restoring force age some nuclear + + align:start position:0% +plus a restoring force age some nuclear + + + align:start position:0% +plus a restoring force age some nuclear +oscillation so this is an estimate so + + align:start position:0% +oscillation so this is an estimate so + + + align:start position:0% +oscillation so this is an estimate so +it's not very rigorous but I think it + + align:start position:0% +it's not very rigorous but I think it + + + align:start position:0% +it's not very rigorous but I think it +will be clear enough now this restoring + + align:start position:0% +will be clear enough now this restoring + + + align:start position:0% +will be clear enough now this restoring +force has to do with the cloud of the + + align:start position:0% +force has to do with the cloud of the + + + align:start position:0% +force has to do with the cloud of the +electrons that are just and those things + + align:start position:0% +electrons that are just and those things + + + align:start position:0% +electrons that are just and those things +as you separate the nuclei you have to + + align:start position:0% +as you separate the nuclei you have to + + + align:start position:0% +as you separate the nuclei you have to +restore this the restoring energies due + + align:start position:0% +restore this the restoring energies due + + + align:start position:0% +restore this the restoring energies due +to the electrons and the Coulomb forces + + align:start position:0% +to the electrons and the Coulomb forces + + + align:start position:0% +to the electrons and the Coulomb forces +but it's not does not depend on the mass + + align:start position:0% +but it's not does not depend on the mass + + + align:start position:0% +but it's not does not depend on the mass +m the restoring force so this K depends + + align:start position:0% +m the restoring force so this K depends + + + align:start position:0% +m the restoring force so this K depends +on the electrons and Coulomb forces but + + align:start position:0% +on the electrons and Coulomb forces but + + + align:start position:0% +on the electrons and Coulomb forces but +definitely not on the mass of this + + align:start position:0% +definitely not on the mass of this + + + align:start position:0% +definitely not on the mass of this +quantity so k has units of e over l + + align:start position:0% +quantity so k has units of e over l + + + align:start position:0% +quantity so k has units of e over l +squared and for energy we have this + + align:start position:0% +squared and for energy we have this + + + align:start position:0% +squared and for energy we have this +energy of the electron and length the + + align:start position:0% +energy of the electron and length the + + + align:start position:0% +energy of the electron and length the +length the scale of the molecule so K is + + align:start position:0% +length the scale of the molecule so K is + + + align:start position:0% +length the scale of the molecule so K is +proportional to H squared over m a to + + align:start position:0% +proportional to H squared over m a to + + + align:start position:0% +proportional to H squared over m a to +the fourth + + align:start position:0% +the fourth + + + align:start position:0% +the fourth +it just cannot depend on the mass of the + + align:start position:0% +it just cannot depend on the mass of the + + + align:start position:0% +it just cannot depend on the mass of the +nuclei thats definitely not the origin + + align:start position:0% +nuclei thats definitely not the origin + + + align:start position:0% +nuclei thats definitely not the origin +of the restoring force so if the only + + align:start position:0% +of the restoring force so if the only + + + align:start position:0% +of the restoring force so if the only +mass you can use is the mass of the + + align:start position:0% +mass you can use is the mass of the + + + align:start position:0% +mass you can use is the mass of the +electron it can only be that but then + + align:start position:0% +electron it can only be that but then + + + align:start position:0% +electron it can only be that but then +the frequency Omega is square root of K + + align:start position:0% +the frequency Omega is square root of K + + + align:start position:0% +the frequency Omega is square root of K +over m that is the mass of the nuclei so + + align:start position:0% +over m that is the mass of the nuclei so + + + align:start position:0% +over m that is the mass of the nuclei so +the nuclear frequency is this and it's + + align:start position:0% +the nuclear frequency is this and it's + + + align:start position:0% +the nuclear frequency is this and it's +therefore equal to H squared over m a + + align:start position:0% +therefore equal to H squared over m a + + + align:start position:0% +therefore equal to H squared over m a +fourth one over m that was k + + align:start position:0% +fourth one over m that was k + + + align:start position:0% +fourth one over m that was k +and this is square root of little m over + + align:start position:0% +and this is square root of little m over + + + align:start position:0% +and this is square root of little m over +capital M times square root of H squared + + align:start position:0% +capital M times square root of H squared + + + align:start position:0% +capital M times square root of H squared +over m squared a to the fourth + + align:start position:0% +over m squared a to the fourth + + + align:start position:0% +over m squared a to the fourth +I borrowed a little m up and a little em + + align:start position:0% +I borrowed a little m up and a little em + + + align:start position:0% +I borrowed a little m up and a little em +down so from here we get that H bar + + align:start position:0% +down so from here we get that H bar + + + align:start position:0% +down so from here we get that H bar +Omega nuclear is square root of little m + + align:start position:0% +Omega nuclear is square root of little m + + + align:start position:0% +Omega nuclear is square root of little m +over capital M H squared over m a + + align:start position:0% +over capital M H squared over m a + + + align:start position:0% +over capital M H squared over m a +squared if you take the square root here + + align:start position:0% +squared if you take the square root here + + + align:start position:0% +squared if you take the square root here +you get h bar over m a squared but there + + align:start position:0% +you get h bar over m a squared but there + + + align:start position:0% +you get h bar over m a squared but there +was another H bar I put in and now we + + align:start position:0% +was another H bar I put in and now we + + + align:start position:0% +was another H bar I put in and now we +get a sensible equation in which we see + + align:start position:0% +get a sensible equation in which we see + + + align:start position:0% +get a sensible equation in which we see +that the nuclear energies for + + align:start position:0% +that the nuclear energies for + + + align:start position:0% +that the nuclear energies for +oscillation are much smaller + + align:start position:0% +oscillation are much smaller + + + align:start position:0% +oscillation are much smaller +significantly smaller so II nuclear + + align:start position:0% +significantly smaller so II nuclear + + + align:start position:0% +significantly smaller so II nuclear +oscillations go like square root of M + + align:start position:0% +oscillations go like square root of M + + + align:start position:0% +oscillations go like square root of M +over m is 10 to the minus 4 with a + + align:start position:0% +over m is 10 to the minus 4 with a + + + align:start position:0% +over m is 10 to the minus 4 with a +square root is 10 to the minus 2 times e + + align:start position:0% +square root is 10 to the minus 2 times e + + + align:start position:0% +square root is 10 to the minus 2 times e +electronic so it's considerably less + + align:start position:0% +electronic so it's considerably less + + + align:start position:0% +electronic so it's considerably less +which is this so of if you think I I + + align:start position:0% +which is this so of if you think I I + + + align:start position:0% +which is this so of if you think I I +want to make another observation here on + + align:start position:0% +want to make another observation here on + + + align:start position:0% +want to make another observation here on +time scales so Omega n we have it here + + align:start position:0% + + + + align:start position:0% + +Omega N or we have it here as well is + + align:start position:0% +Omega N or we have it here as well is + + + align:start position:0% +Omega N or we have it here as well is +equal to this times this quantity so let + + align:start position:0% +equal to this times this quantity so let + + + align:start position:0% +equal to this times this quantity so let +me say this way the Omega electronic for + + align:start position:0% +me say this way the Omega electronic for + + + align:start position:0% +me say this way the Omega electronic for +vibrations + + align:start position:0% +vibrations + + + align:start position:0% +vibrations +is the electronic energy divided by + + align:start position:0% +is the electronic energy divided by + + + align:start position:0% +is the electronic energy divided by +h-bar and its h-bar over ma squared but + + align:start position:0% +h-bar and its h-bar over ma squared but + + + align:start position:0% +h-bar and its h-bar over ma squared but +here we see that that's precisely that + + align:start position:0% +here we see that that's precisely that + + + align:start position:0% +here we see that that's precisely that +square root so the Omega nuclear is + + align:start position:0% +square root so the Omega nuclear is + + + align:start position:0% +square root so the Omega nuclear is +equal to little M over m Omega + + align:start position:0% +equal to little M over m Omega + + + align:start position:0% +equal to little M over m Omega +electronic now that is nice because it + + align:start position:0% +electronic now that is nice because it + + + align:start position:0% +electronic now that is nice because it +says that the frequency associated to + + align:start position:0% +says that the frequency associated to + + + align:start position:0% +says that the frequency associated to +the nuclear thing is much smaller than + + align:start position:0% +the nuclear thing is much smaller than + + + align:start position:0% +the nuclear thing is much smaller than +the timescales associated with the + + align:start position:0% +the timescales associated with the + + + align:start position:0% +the timescales associated with the +electronic changes so this is a good + + align:start position:0% +electronic changes so this is a good + + + align:start position:0% +electronic changes so this is a good +reason for our adiabatic thinking that + + align:start position:0% +reason for our adiabatic thinking that + + + align:start position:0% +reason for our adiabatic thinking that +as the nuclei so lowly oscillate the + + align:start position:0% +as the nuclei so lowly oscillate the + + + align:start position:0% +as the nuclei so lowly oscillate the +electronic cloud remains in that + + align:start position:0% +electronic cloud remains in that + + + align:start position:0% +electronic cloud remains in that +particular eigenstate and doesn't jump + + align:start position:0% +particular eigenstate and doesn't jump + + + align:start position:0% +particular eigenstate and doesn't jump +it's our use of the adiabatic + + align:start position:0% +it's our use of the adiabatic + + + align:start position:0% +it's our use of the adiabatic +approximation our last comment is that + + align:start position:0% +approximation our last comment is that + + + align:start position:0% +approximation our last comment is that +the rotational energy of the molecule + + align:start position:0% +the rotational energy of the molecule + + + align:start position:0% +the rotational energy of the molecule +goes like the angular momentum squared + + align:start position:0% +goes like the angular momentum squared + + + align:start position:0% +goes like the angular momentum squared +over twice the moment of inertia l + + align:start position:0% +over twice the moment of inertia l + + + align:start position:0% +over twice the moment of inertia l +squared is H squared times some numbers + + align:start position:0% +squared is H squared times some numbers + + + align:start position:0% +squared is H squared times some numbers +as usual L times L plus one and here you + + align:start position:0% +as usual L times L plus one and here you + + + align:start position:0% +as usual L times L plus one and here you +get the mass of the molecule times the + + align:start position:0% +get the mass of the molecule times the + + + align:start position:0% +get the mass of the molecule times the +size squared of the molecules this + + align:start position:0% +size squared of the molecules this + + + align:start position:0% +size squared of the molecules this +energies are like little M over capital + + align:start position:0% +energies are like little M over capital + + + align:start position:0% +energies are like little M over capital +M times this is roughly H squared over + + align:start position:0% +M times this is roughly H squared over + + + align:start position:0% +M times this is roughly H squared over +little M a squared and therefore the + + align:start position:0% +little M a squared and therefore the + + + align:start position:0% +little M a squared and therefore the +rotational energies are even smaller + + align:start position:0% +rotational energies are even smaller + + + align:start position:0% +rotational energies are even smaller +than the electronic energies the + + align:start position:0% +than the electronic energies the + + + align:start position:0% +than the electronic energies the +rotational energies go like little M + + align:start position:0% +rotational energies go like little M + + + align:start position:0% +rotational energies go like little M +over capital n time + + align:start position:0% +over capital n time + + + align:start position:0% +over capital n time +electronic energies so you have the + + align:start position:0% +electronic energies so you have the + + + align:start position:0% +electronic energies so you have the +electronic energies the nuclear energies + + align:start position:0% +electronic energies the nuclear energies + + + align:start position:0% +electronic energies the nuclear energies +of oscillation which glow like square + + align:start position:0% +of oscillation which glow like square + + + align:start position:0% +of oscillation which glow like square +root and then finally the smallest of + + align:start position:0% +root and then finally the smallest of + + + align:start position:0% +root and then finally the smallest of +them are the rotation which the molecule + + align:start position:0% +them are the rotation which the molecule + + + align:start position:0% +them are the rotation which the molecule +rotates like a solid object we'll + + align:start position:0% +rotates like a solid object we'll + + + align:start position:0% +rotates like a solid object we'll +continue this next time and calculate + + align:start position:0% +continue this next time and calculate + + + align:start position:0% +continue this next time and calculate +the few more things and more \ No newline at end of file diff --git a/ArfHGPHL8kU.txt b/ArfHGPHL8kU.txt new file mode 100644 index 0000000000000000000000000000000000000000..be88e4b595cb8eb203dcf4983c4566ab8ad1eaa0 --- /dev/null +++ b/ArfHGPHL8kU.txt @@ -0,0 +1,283 @@ +align:start position:0% + +in this lecture we introduced the notion + + align:start position:0% +in this lecture we introduced the notion + + + align:start position:0% +in this lecture we introduced the notion +of a random variable a random variable + + align:start position:0% +of a random variable a random variable + + + align:start position:0% +of a random variable a random variable +is loosely speaking a numerical quantity + + align:start position:0% +is loosely speaking a numerical quantity + + + align:start position:0% +is loosely speaking a numerical quantity +whose value is determined by the outcome + + align:start position:0% +whose value is determined by the outcome + + + align:start position:0% +whose value is determined by the outcome +of a probabilistic experiment the weight + + align:start position:0% +of a probabilistic experiment the weight + + + align:start position:0% +of a probabilistic experiment the weight +of a randomly selected student is one + + align:start position:0% +of a randomly selected student is one + + + align:start position:0% +of a randomly selected student is one +example after giving a general + + align:start position:0% +example after giving a general + + + align:start position:0% +example after giving a general +definition we will focus exclusively on + + align:start position:0% +definition we will focus exclusively on + + + align:start position:0% +definition we will focus exclusively on +discrete random variables these are + + align:start position:0% +discrete random variables these are + + + align:start position:0% +discrete random variables these are +random variables that take values in + + align:start position:0% +random variables that take values in + + + align:start position:0% +random variables that take values in +finite or countably infinite sets for + + align:start position:0% +finite or countably infinite sets for + + + align:start position:0% +finite or countably infinite sets for +example random variables that take + + align:start position:0% +example random variables that take + + + align:start position:0% +example random variables that take +integer values are discrete twenty + + align:start position:0% +integer values are discrete twenty + + + align:start position:0% +integer values are discrete twenty +discrete random variable we will + + align:start position:0% +discrete random variable we will + + + align:start position:0% +discrete random variable we will +associate a probability mass function + + align:start position:0% +associate a probability mass function + + + align:start position:0% +associate a probability mass function +which tells us the likelihood of each + + align:start position:0% +which tells us the likelihood of each + + + align:start position:0% +which tells us the likelihood of each +possible value of the random variable + + align:start position:0% +possible value of the random variable + + + align:start position:0% +possible value of the random variable +then we will go over a few examples and + + align:start position:0% +then we will go over a few examples and + + + align:start position:0% +then we will go over a few examples and +introduce some common types of random + + align:start position:0% +introduce some common types of random + + + align:start position:0% +introduce some common types of random +variables and finally we will introduce + + align:start position:0% +variables and finally we will introduce + + + align:start position:0% +variables and finally we will introduce +a new concept the expected value of a + + align:start position:0% +a new concept the expected value of a + + + align:start position:0% +a new concept the expected value of a +random variable also called + + align:start position:0% +random variable also called + + + align:start position:0% +random variable also called +the expectation or mean it is a weighted + + align:start position:0% +the expectation or mean it is a weighted + + + align:start position:0% +the expectation or mean it is a weighted +average of the values of the random + + align:start position:0% +average of the values of the random + + + align:start position:0% +average of the values of the random +variable weighted according to their + + align:start position:0% +variable weighted according to their + + + align:start position:0% +variable weighted according to their +respective probabilities and has an + + align:start position:0% +respective probabilities and has an + + + align:start position:0% +respective probabilities and has an +intuitive interpretation as the average + + align:start position:0% +intuitive interpretation as the average + + + align:start position:0% +intuitive interpretation as the average +value we expect to see if we repeat the + + align:start position:0% +value we expect to see if we repeat the + + + align:start position:0% +value we expect to see if we repeat the +same probabilistic experiment + + align:start position:0% +same probabilistic experiment + + + align:start position:0% +same probabilistic experiment +independently a large number of times + + align:start position:0% +independently a large number of times + + + align:start position:0% +independently a large number of times +expected values play a central role in + + align:start position:0% +expected values play a central role in + + + align:start position:0% +expected values play a central role in +probability theory we will look into + + align:start position:0% +probability theory we will look into + + + align:start position:0% +probability theory we will look into +some of their properties and we will + + align:start position:0% +some of their properties and we will + + + align:start position:0% +some of their properties and we will +also calculate the expected values of + + align:start position:0% +also calculate the expected values of + + + align:start position:0% +also calculate the expected values of +the example random variables that we + + align:start position:0% +the example random variables that we + + + align:start position:0% +the example random variables that we +will have introduced \ No newline at end of file diff --git a/Bzqpuuoq4bI.txt b/Bzqpuuoq4bI.txt new file mode 100644 index 0000000000000000000000000000000000000000..e1ad6404f9ed2cc4cfabfb0b00b7a2b5857f7242 --- /dev/null +++ b/Bzqpuuoq4bI.txt @@ -0,0 +1,162 @@ +In order to satisfy the static discipline, +a circuit must produce outputs that are better + +than the acceptable inputs. + +This ensures that if you concatenate multiple +gates together, for example one buffer followed + +by another buffer, then the input to each +gate will be valid even if a small amount + +of noise was introduced by the previous gate. + +So taking a closer look at that, what that +means is that if I have a valid input at my + +first buffer, and I am guaranteeing that the +output that I produce is slightly better than + +my original input, then even if a little bit +of noise was introduced, the input to the + +second buffer is still going to be considered +a valid input. + +More concretely, to satisfy the static discipline, +a valid low output must be less than a valid + +low input. + +The way that we specify this is that is that +V<sub>ol</sub> < V<sub>il</sub>. + +Also, a valid high output must be greater +than a valid high input. + +So V<sub>oh</sub> must be greater than V<sub>ih</sub>. + +If we put this all together, we have V<sub>ol</sub> +< V<sub>il</sub> and V<sub>ih</sub> < V<sub>oh</sub> + +and of course we want our low inputs to be +less than or equal to our high inputs, so + +V<sub>il</sub> <= V<sub>ih</sub>. + +Another way to think about this is to look +at the orange and green arrows which show + +the ranges of valid inputs which are wider +than the ranges of valid outputs. + +The other thing that is shown here are the +noise margins which correspond to the area + +of valid inputs but invalid outputs. + +As we said earlier, a valid input must always +produce a valid output. + +A valid input has V<sub>in</sub> < V<sub>il</sub> +if its low or V<sub>in</sub> > V<sub>ih</sub> + +if its high. + +A valid output has V<sub>out</sub> < V<sub>ol</sub> +if its low and V<sub>out</sub> > V<sub>oh</sub> + +if its high. + +In this problem, we want to determine whether +specifications 1, 2, and 3 (which provide + +0.3 volt noise margins) satisfy the static +discipline given the voltage transfer curve + +shown here. + +For each specification, we need to check the +following two constraints: + +1) Is V<sub>ol</sub> < V<sub>il</sub> <= V<sub>ih</sub> +< V<sub>oh</sub> - satisfying this constraint + +guarantees that the outputs produced are better +in quality than the inputs. + +The second constraint is: Does a valid input +produce a valid output? + +Since this curve shows an inverting function, +this translates to: + +a) Does a valid input (where V<sub>in</sub> +< V<sub>il</sub>) always produce a valid high + +output (where V<sub>out</sub> > V<sub>oh</sub>)? + +And b) Does a valid high input (where V<sub>in</sub> +> V<sub>ih</sub>) always produce a valid low + +output (where V<sub>out</sub> < V<sub>ol</sub>)? + +If all of these constraints are satisfied, +then that specification obeys the static discipline. + +If not, it doesn't. + +For all three specifications, we see that +indeed V<sub>ol</sub> < V<sub>il</sub> < V<sub>ih</sub> + +< V<sub>oh</sub>, so the first constraint +is satisfied for all three specifications. + +Now let's check the second constraint. + +For specification #1: If V<sub>in</sub> < V<sub>il</sub> +which is equal to 0.4, then V<sub>out</sub> + += 5 which is greater than V<sub>oh</sub> which +is 4.9, so a valid low input produces a valid + +high output. + +If V<sub>in</sub> > V<sub>ih</sub> which equals +4.6 then V<sub>out</sub> equals 0 which is + +less than V<sub>ol</sub> which is 0.1, so +a valid high input produces a valid low output. + +Since all of the constraints are satisfied, +specification #1 satisfies the static discipline. + +For specification #2: If V<sub>in</sub> < 0.9 +then V<sub>out</sub> >= 4 which is not greater + +than> V<sub>oh</sub> which is 4.4. + +So this specification does not satisfy the +static discipline. + +For specification #3: If V<sub>in</sub> < 1.4 +then V<sub>out</sub> >= 4 which in this case + +is greater than V<sub>oh</sub> which is 3.9. + +So the first part of the constraint checks +out. + +Now we need to check what happens when we +have a valid high input. + +In this case, if V<sub>in</sub> > 3.6 then +V<sub>out</sub> <= 1 which is less than V<sub>ol</sub> + +or 1.1, so this part of the constraint checks +out as well. + +Since all the constraints are satisfied, that +means that specification #3 also satisfies + +the static discipline. \ No newline at end of file diff --git a/CadZXGNauY0.txt b/CadZXGNauY0.txt new file mode 100644 index 0000000000000000000000000000000000000000..d9f0ab71947a807c9750eb88e1509c7c4ccf649e --- /dev/null +++ b/CadZXGNauY0.txt @@ -0,0 +1,2542 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +JOHN TSITSIKLIS: +OK let's start. + +So we've had the quiz. + +And I guess there's both good +and bad news in it. + +Yesterday, as you know, +the bad news. + +The average was a little +lower than what + +we would have wanted. + +On the other hand, the good news +is that the distribution + +was nicely spread. + +And that's the main purpose of +this quiz is basically for you + +to calibrate and see roughly +where you are standing. + +The other piece of the good +news is that, as you know, + +this quiz doesn't count for very +much in your final grade. + +So it's really a matter of +calibration and to get your + +mind set appropriately to +prepare for the second quiz, + +which counts a lot more. + +And it's more substantial. + +And we'll make sure that +the second quiz will + +have a higher average. + +All right. + +So let's go to our material. + +We're talking now +these days about + +continuous random variables. + +And I'll remind you what +we discussed last time. + +I'll remind you of the concept +of the probability density + +function of a single +random variable. + +And then we're going to rush +through all the concepts that + +we covered for the case of +discrete random variables and + +discuss their analogs for +the continuous case. + +And talk about notions +such as conditioning + +independence and so on. + +So the big picture is here. + +We have all those concepts that +we developed for the case + +of discrete random variables. + +And now we will just talk about +their analogs in the + +continuous case. + +We already discussed this analog +last week, the density + +of a single random variable. + +Then there are certain concepts +that show up both in + +the discrete and the +continuous case. + +So we have the cumulative +distribution function, which + +is a description of the +probability distribution of a + +random variable and which +applies whether you have a + +discrete or continuous +random variable. + +Then there's the notion +of the expected value. + +And in the two cases, the +expected value is calculated + +in a slightly different way, +but not very different. + +We have sums in one case, +integrals in the other. + +And this is the general +pattern that + +we're going to have. + +Formulas for the discrete case +translate to corresponding + +formulas or expressions in +the continuous case. + +We generically replace sums by +integrals, and we replace must + +functions with density +functions. + +Then the new pieces for today +are going to be mostly the + +notion of a joint density +function, which is how we + +describe the probability +distribution of two random + +variables that are somehow +related, in general, and then + +the notion of a conditional +density function that tells us + +the distribution of one random +variable X when you're told + +the value of another random +variable Y. There's another + +concept, which is the +conditional PDF given that the + +certain event has happened. + +This is a concept that's +in some ways simpler. + +You've already seen a little +bit of that in last week's + +recitation and tutorial. + +The idea is that we have a +single random variable. + +It's described by a density. + +Then you're told that the +certain event has occurred. + +Your model changes +the universe that + +you are dealing with. + +In the new universe, you are +dealing with a new density + +function, the one that applies +given the knowledge that we + +have that the certain +event has occurred. + +All right. + +So what exactly did +we say about + +continuous random variables? + +The first thing is the +definition, that a random + +variable is said to be +continuous if we are given a + +certain object that we call +the probability density + +function and we can calculate +interval probabilities given + +this density function. + +So the definition is that the +random variable is continuous + +if you can calculate +probabilities associated with + +that random variable +given that formula. + +So this formula tells you that +the probability that your + +random variable falls inside +this interval is the area + +under the density curve. + +OK. + +There's a few properties +that a density + +function must satisfy. + +Since we're talking about +probabilities, and + +probabilities are non-negative, +we have that the + +density function is always +a non-negative function. + +The total probability over +the entire real line + +must be equal to 1. + +So the integral when you +integrate over the entire real + +line has to be equal to 1. + +That's the second property. + +Another property that you get is +that if you let a equal to + +b, this integral becomes 0. + +And that tells you that the +probability of a single point + +in the continuous case +is always equal to 0. + +So these are formal +properties. + +When you want to think +intuitively, the best way to + +think about what the density +function is to think in terms + +of little intervals, the +probability that my random + +variable falls inside +the little interval. + +Well, inside that little +interval, the density function + +here is roughly constant. + +So that integral becomes the +value of the density times the + +length of the interval over +which you are integrating, + +which is delta. + +And so the density function +basically gives us + +probabilities of little events, +of small events. + +And the density is to be +interpreted as probability per + +unit length at a certain +place in the diagram. + +So in that place in the diagram, +the probability per + +unit length around this +neighborhood would be the + +height of the density function +at that point. + +What else? + +We have a formula for +calculating expected values of + +functions of random variables. + +In the discrete case, we had the +formula where here we had + +the sum, and instead of the +density, we had the PMF. + +The same formula is also valid +in the continuous case. + +And it's not too hard to derive, +but we will not do it. + +But let's think of the +intuition of what + +this formula says. + +You're trying to figure out on +the average how much g(X) is + +going to be. + +And then you reason, and you +say, well, X may turn out to + +take a particular value or a +small interval of values. + +This is the probability +that X falls + +inside the small interval. + +And when that happens, g(X) +takes that value. + +So this fraction of the time, +you fall in the little + +neighborhood of x, and +you get so much. + +Then you average over all the +possible x's that can happen. + +And that gives you the average +value of the function g(X). + +OK. + +So this is the easy stuff. + +Now let's get to the +new material. + +We want to talk about multiple +random variables + +simultaneously. + +So we want to talk now about two +random variables that are + +continuous, and in some sense +that they are jointly + +continuous. + +And let's see what this means. + +The definition is similar to +the definition we had for a + +single random variable, where +I take this formula here as + +the definition of continuous +random variables. + +Two random variables are said to +be jointly continuous if we + +can calculate probabilities by +integrating a certain function + +that we call the joint +density function + +over the set of interest. + +So we have our two-dimensional +plane. + +This is the x-y plane. + +There's a certain event S that +we're interested in. + +We want to calculate +the probability. + +How do we do that? + +We are given this function +f_(X,Y), the joint density. + +It's a function of the two +arguments x and y. + +So think of that function as +being some kind of surface + +that sits on top of the +two-dimensional plane. + +The probability of falling +inside the set S, we calculate + +it by looking at the volume +under the surface, that volume + +that sits on top of S. So the +surface underneath it has a + +certain total volume. + +What should that total +volume be? + +Well, we think of these volumes +as probabilities. + +So the total probability +should be equal to 1. + +The total volume under this +surface, should be equal to 1. + +So that's one property +that we want our + +density function to have. + +So when you integrate over the +entire space, this is of the + +volume under your surface. + +That should be equal to 1. + +Of course, since we're talking +about probabilities, the joint + +density should be a non-negative +function. + +So think of the situation +as having one pound of + +probability that's spread +all over your space. + +And the height of this joint +density function basically + +tells you how much probability +tends to be accumulated in + +certain regions of space +as opposed to other + +parts of the space. + +So wherever the density is big, +that means that this is + +an area of the two-dimensional +plane that's + +more likely to occur. + +Where the density is small, that +means that those x-y's + +are less likely to occur. + +You have already seen +one example + +of continuous densities. + +That was the example we had in +the very beginning of the + +class with a uniform + +distribution on the unit square. + +That was a special +case of a density + +function that was constant. + +So all places in the unit square +were roughly equally + +likely as any other places. + +But in other models, some parts +of the space may be more + +likely than others. + +And we describe those relative +likelihoods using + +this density function. + +So if somebody gives us the +density function, this + +determines for us probabilities +of all the + +subsets of the two-dimensional +plane. + +Now for an intuitive +interpretation, it's good to + +think about small events. + +So let's take a particular x +here and then x plus delta. + +So this is a small interval. + +Take another small interval +here that goes from y to y + +plus delta. + +And let's look at the event that +x falls here and y falls + +right there. + +What is this event? + +Well, this is the event +that will fall + +inside this little rectangle. + +Using this rule for calculating +probabilities, + +what is the probability of that +rectangle going to be? + +Well, it should be the integral +of the density over + +this rectangle. + +Or it's the volume under the +surface that sits on top of + +that rectangle. + +Now, if the rectangle is very +small, the joint density is + +not going to change very much +in that neighborhood. + +So we can treat it +as a constant. + +So the volume is going to +be the height times + +the area of the base. + +The height at that point is +whatever the function happens + +to be around that point. + +And the area of the base +is delta squared. + +So this is the intuitive way +to understand what a joint + +density function really +tells you. + +It specifies for you +probabilities of little + +squares, of little rectangles. + +And it allows you to think of +the joint density function as + +probability per unit area. + +So these are the units of the +density, its probability per + +unit area in the neighborhood +of a certain point. + +So what do we do with this +density function once we have + +it in our hands? + +Well, we can use it to calculate +expected values. + +Suppose that you have a +function of two random + +variables described by +a joint density. + +You can find, perhaps, the +distribution of this random + +variable and then use the +basic definition of the + +expectation. + +Or you can calculate +expectations directly, using + +the distribution of the original +random variables. + +This is a formula that's again +identical to the formula that + +we had for the discrete case. + +In the discrete case, +we had a double sum + +here, and we had PMFs. + +So the intuition behind this +formula is the same that one + +had for the discrete case. + +It's just that the mechanics +are different. + +Then something that we did in +the discrete case was to find + +a way to go from the joint +density of the two random + +variables taken together to the +density of just one of the + +random variables. + +So we had a formula for +the discrete case. + +Let's see how things are +going to work out in + +the continuous case. + +So in the continuous +case, we have here + +our two random variables. + +And we have a density +for them. + +And let's say that we want to +calculate the probability that + +x falls inside this interval. + +So we're looking at the +probability that our random + +variable X falls in the interval +from little x to x + +plus delta. + +Now, by the properties that we +already have for interpreting + +the density function of a single +random variable, the + +probability of a little interval +is approximately the + +density of that single random +variable times delta. + +And now we want to find a +formula for this marginal + +density in terms of +the joint density. + +OK. + +So this is the probability +that x + +falls inside this interval. + +In terms of the two-dimensional +plane, this is + +the probability that (x,y) +falls inside this strip. + +So to find that probability, +we need to calculate the + +probability that (x,y) falls in +here, which is going to be + +the double integral over the +interval over this strip, of + +the joint density. + +And what are we integrating +over? + +y goes from minus infinity +to plus infinity. + +And the dummy variable x goes +from little x to x plus delta. + +So to integrate over this strip, +what we do is for any + +given y, we integrate +in this dimension. + +This is the x integral. + +And then we integrate over +the y dimension. + +Now what is this +inner integral? + +Because x only varies very +little, this is approximately + +constant in that range. + +So the integral with +respect to x just + +becomes delta times f(x,y). + +And then we've got our dy. + +So this is what the inner +integral will evaluate to. + +We are integrating over +the little interval. + +So we're keeping y fixed. + +Integrating over here, we take +the value of the density times + +how much we're integrating +over. + +And we get this formula. + +OK. + +Now, this expression must be +equal to that expression. + +So if we cancel the deltas, we +see that the marginal density + +must be equal to the integral of +the joint density, where we + +have integrated out +the value of y. + +So this formula should come as +no surprise at this point. + +It's exactly the same as the +formula that we had for + +discrete random variables. + +But now we are replacing the +sum with an integral. + +And instead of using the +joint PMF, we are + +using the joint PDF. + +Then, continuing going down the +list of things we did for + +discrete random variables, we +can now introduce a definition + +of the notion of independence +of two random variables. + +And by analogy with the discrete +case, we define + +independence to be the +following condition. + +Two random variables are +independent if and only if + +their joint density function +factors out as a product of + +their marginal densities. + +And this property needs to +be true for all x and y. + +So this is the formal +definition. + +Operationally and intuitively, +what does it mean? + +Well, intuitively it means +the same thing as in + +the discrete case. + +Knowing anything about X +shouldn't tell you anything + +about Y. That is, information +about X is not going to change + +your beliefs about Y. We are +going to come back to this + +statement in a second. + +The other thing that it +allows you to do-- + +I'm not going to derive this-- +is it allows you to calculate + +probabilities by multiplying +individual probabilities. + +So if you ask for the +probability that x falls in a + +certain set A and y falls in a +certain set B, then you can + +calculate that probability +by multiplying individual + +probabilities. + +This takes just two lines of +derivation, which I'm not + +going to do. + +But it comes back to +the usual notion of + +independence of events. + +Basically, operationally +independence means that you + +can multiply probabilities. + +So now let's look +at an example. + +There's a sort of pretty famous +and classical one. + +It goes back a lot more +than a 100 years. + +And it's the famous +Needle of Buffon. + +Buffon was a French naturalist +who, for some reason, also + +decided to play with +probability. + +And look at the following +problem. + +So you have the two-dimensional +plane. + +And on the plane we draw a +bunch of parallel lines. + +And those parallel lines are +separated by a length. + +And the lines are apart +at distance d. + +And we throw a needle at random, +completely at random. + +And we'll have to give a meaning +to what "completely at + +random" means. + +And when we throw a needle, +there's two possibilities. + +Either the needle is going to +fall in a way that does not + +intersect any of the lines, or +it's going to fall in a way + +that it intersects +one of the lines. + +We're taking the needle to be +shorter than this distance, so + +the needle cannot intersect +two lines simultaneously. + +It either intersects 0, or it +intersects one of the lines. + +The question is to find the +probability that the needle is + +going to intersect a line. + +What's the probability +of this? + +OK. + +We are going to approach this +problem by using our standard + +four-step procedure. + +Set up your sample space, +describe a probability law on + +that sample space, identify +the event of interest, and + +then calculate. + +These four steps basically +correspond to these three + +bullets and then the last +equation down here. + +So first thing is to set +up a sample space. + +We need some variables to +describe what happened in the + +experiment. + +So what happens in the +experiment is that the needle + +lands somewhere. + +And where it lands, we can +describe this by specifying + +the location of the center +of the needle. + +And what do we mean by the +location of the center? + +Well, we can take as our +variable to be the distance + +from the center of the needle +to the nearest line. + +So it tells us the vertical +distance of the center of the + +needle from the nearest line. + +The other thing that +matters is the + +orientation of the needle. + +So we need one more variable, +which we take to be the angle + +that the needle is forming +with the lines. + +We can put the angle here, +or you can put in there. + +Yes, it's still the +same angle. + +So we have these two variables +that described what happened + +in the experiment. + +And we can take our sample space +to be the set of all + +possible x's and theta's. + +What are the possible x's? + +The lines are d apart, so the +nearest line is going to be + +anywhere between +0 and d/2 away. + +So that tells us what the +possible x's will be. + +As for theta, it really +depends how + +you define your angle. + +We are going to define our theta +to be the acute angle + +that's formed between the needle +and a line, if you were + +to extend it. + +So theta is going to be +something between 0 and pi/2. + +So I guess these red pieces +really correspond to the part + +of setting up the +sample space. + +OK. + +So that's part one. + +Second part is we +need a model. + +OK. + +Let's take our model to be that +we basically know nothing + +about how the needle falls. + +It can fall in any possible way, +and all possible ways are + +equally likely. + +Now, if you have those parallel +lines, and you close + +your eyes completely and throw a +needle completely at random, + +any x should be equally +likely. + +So we describe that situation by +saying that X should have a + +uniform distribution. + +That is, it should have a +constant density over the + +range of interest. + +Similarly, if you kind of spin +your needle completely at + +random, any angle should be as +likely as any other angle. + +And we decide to model this +situation by saying that theta + +also has a uniform +distribution over + +the range of interest. + +And finally, where we put it +should have nothing to do with + +how much we rotate it. + +And we capture this +mathematically by saying that + +X is going to be independent +of theta. + +Now, this is going +to be our model. + +I'm not deriving the model +from anything. + +I'm only saying that this sounds +like a model that does + +not assume any knowledge or +preference for certain values + +of x rather than other +values of theta. + +In the absence of any other +particular information you + +might have in your hands, that's +the most reasonable + +model to come up with. + +So you model the problem +that way. + +So what's the formula for +the joint density? + +It's going to be the +product of the + +densities of X and Theta. + +Why is it the product? + +This is because we assumed +independence. + +And the density of X, since +it's uniform, and since it + +needs to integrate to 1, that +density needs to be 2/d. + +That's the density of X. +And the density of + +Theta needs to be 2/pi. + +That's the value for the density +of Theta so that the + +overall probability over this +interval ends up being 1. + +So now we do have our joint +density in our hands. + +The next thing to do +is to identify + +the event of interest. + +And this is best done +in a picture. + +And there's two possible +situations + +that one could have. + +Either the needle falls this +way, or it falls this way. + +So how can we tell if one or the +other is going to happen? + +It has to do with whether this +interval here is smaller than + +that or bigger than that. + +So we are comparing +the height of this + +interval to that interval. + +This interval here +is capital X. + +This interval here, +what is it? + +This is half of the length of +the needle, which is l/2. + +To find this height, we take l/2 +and multiply it with the + +sine of the angle +that we have. + +So the length of this +interval up here is + +l/2 times sine theta. + +If this is smaller than +x, the needle does not + +intersect the line. + +If this is bigger than +x, then the needle + +intersects the line. + +So the event of interest, that +the needle intersects the + +line, is described this way +in terms of x and theta. + +And now that we have the event +of interest described + +mathematically, all that we +need to do is to find the + +probability of this event, we +integrate the joint density + +over the part of (x, theta) +space in which this + +inequality is true. + +So it's a double integral over +the set of all x's and theta's + +where this is true. + +The way to do this integral is +we fix theta, and we integrate + +for x's that go from 0 +up to that number. + +And theta can be anything +between 0 and pi/2. + +So the integral over this set +is basically this double + +integral here. + +We already have a formula +for the joint density. + +It's 4 over pi d, so +we put it here. + +And now, fortunately, +this is a pretty + +easy integral to evaluate. + +The integral with respect to x +-- there's nothing in here. + +So the integral is just the +length of the interval over + +which we're integrating. + +It's l/2 sine theta. + +And then we need to integrate +this with respect to theta. + +We know that the integral of a +sine is a negative cosine. + +You plug in the values for +the negative cosine + +at the two end points. + +I'm sure you can do +this integral . + +And we finally obtain the +answer, which is amazingly + +simple for such a pretty +complicated-looking problem. + +It's 2l over pi d. + +So some people a long, long time +ago, after they looked at + +this answer, they said that +maybe that gives us an + +interesting way where one could +estimate the value by + +pi, for example, +experimentally. + +How do you do that? + +Fix l and d, the dimensions +of the problem. + +Throw a million needles on +your piece of paper. + +See how often your needless +do intersect the line. + +That gives you a number +for this quantity. + +You know l and d, so you can +use that to infer pi. + +And there's an apocryphal story +about a wounded soldier + +in a hospital after the +American Civil War who + +actually had heard about this +and was spending his time in + +the hospital throwing needles +on pieces of paper. + +I don't know if it's +true or not. + +But let's do something +similar here. + +So let's look at this diagram. + +We fix the dimensions. + +This is supposed to +be our little d. + +That's supposed to +be our little l. + +We have the formula from the +previous slide that p + +is 2l over pi d. + +In this instance, we choose +d to be twice l. + +So this number is 1/pi. + +So the probability that the +needle hits the line is 1/pi. + +So I need needles that are +3.1 centimeters long. + +I couldn't find such needles. + +But I could find paper clips +that are 3.1 centimeters long. + +So let's start throwing paper +clips at random and see how + +many of them will end up +intersecting the lines. + +Good. + +OK. + +So out of eight paper clips, +we have exactly four that + +intersected the line. + +So our estimate for the +probability of intersecting + +the line is 1/2, which gives us +an estimate for the value + +of pi, which is two. + +Well, I mean, within an +engineering approximation, + +we're in the right +ballpark, right? + +So this might look like a +silly way of trying to + +estimate pi. + +And it probably is. + +On the other hand, this kind of +methodology is being used + +especially by physicists and +also by statisticians. + +It's used a lot. + +When is it used? + +If you have an integral to +calculate, such as this + +integral, but you're not lucky, +and your functions are + +not so simple where you can do +your calculations by hand, and + +maybe the dimensions are +larger-- instead of two random + +variables you have 100 +random variables, so + +it's a 100-fold integral-- + +then there's no way to do +that in the computer. + +But the way that you can +actually do it is by + +generating random samples of +your random variables, doing + +that simulation over and +over many times. + +That is, by interpreting an +integral as a probability, you + +can use simulation to estimate +that probability. + +And that gives you a way of +calculating integrals. + +And physicists do actually use +that a lot, as well as + +statisticians, computer +scientists, and so on. + +It's a so-called Monte +Carlo method + +for evaluating integrals. + +And it's a basic piece of the +toolbox in science these days. + +Finally, the harder concept +of the day is the idea of + +conditioning. + +And here things become a little +subtle when you deal + +with continuous random +variables. + +OK. + +First, remember again our basic +interpretation of what a + +density is. + +A density gives us + +probabilities of little intervals. + +So how should we define +conditional densities? + +Conditional densities should +again give us probabilities of + +little intervals, but inside a +conditional world where we + +have been told something about +the other random variable. + +So what we would like to be +true is the following. + +We would like to define a +concept of a conditional + +density of a random variable X +given the value of another + +random variable Y. And it should +behave the following + +way, that the conditional +density gives us the + +probability of little +intervals-- + +same as here-- + +given that we are told +the value of y. + +And here's where the +subtleties come. + +The main thing to notice is +that here I didn't write + +"equal," I wrote "approximately +equal." Why do + +we need that? + +Well, the thing is that +conditional probabilities are + +not defined when you condition +on an event that has 0 + +probability. + +So we need the conditioning +event here to have posed this + +probability. + +So instead of saying that Y is +exactly equal to little y, we + +want to instead say we're in a +new universe where capital Y + +is very close to little y. + +And then this notion of "very +close" kind of takes the limit + +and takes it to be +infinitesimally close. + +So this is the way to interpret +conditional + +probabilities. + +That's what they should mean. + +Now, in practice, when you +actually use probability, you + +forget about that subtlety. + +And you say, well, I've been +told that Y is equal to 1.3. + +Give me the conditional +distribution of X. But + +formally or rigorously, you +should say I'm being told that + +Y is infinitesimally +close to 1.3. + +Tell me the distribution of X. + +Now, if this is what we want, +what should this quantity be? + +It's a conditional probability, +so it should be + +the probability of two +things happening-- + +X being close to little x, Y +being close to little y. + +And that's basically given to +us by the joint density + +divided by the probability of +the conditioning event, which + +has something to do with the +density of Y itself. + +And if you do things carefully, +you see that the + +only way to satisfy this +relation is to define the + +conditional density by this +particular formula. + +OK. + +Big discussion to come down in +the end to what you should + +have probably guessed by now. + +We just take any formulas and +expressions from the discrete + +case and replace PMFs by PDFs. + +So the conditional PDF is +defined by this formula where + +here we have joint PDF and +marginal PDF, as opposed to + +the discrete case where we +had the joint PMF and + +the marginal PMF. + +So in some sense, it's just +a syntactic change. + +In another sense, it's a little +subtler on how you + +actually interpret it. + +Speaking about interpretation, +what are some ways of thinking + +about the joint density? + +Well, the best way to think +about it is that somebody has + +fixed little y for you. + +So little y is being +fixed here. + +And we look at this density +as a function of X. + +I've told you what Y is. + +Tell me what you know about X. +And you tell me that X has a + +certain distribution. + +What does that distribution +look like? + +It has exactly the same shape +as the joint density. + +Remember, we fixed Y. So +this is a constant. + +So the only thing that varies +is X. So we get the function + +that behaves like the joint +density when you fix y, which + +is really you take the joint +density, and you + +take a slice of it. + +You fix a y, and you see +how it varies with x. + +So in that sense, the +conditional PDF is just a + +slice of the joint PDF. + +But we need to divide by a +certain number, which just + +scales it and changes +its shape. + +We're coming back to a +picture in a second. + +But before going to the picture, +lets go back to the + +interpretation of +independence. + +If the two random the variables +are independent, + +according to our definition in +the previous slide, the joint + +density is going to factor +as the product of + +the marginal densities. + +The density of Y in the +numerator cancels the density + +in the denominator. + +And we're just left with +the density of X. + +So in the case of independence, +what we get is + +that the conditional is the +same as the marginal. + +And that solidifies our +intuition that in the case of + +independence, being told +something about the value of Y + +does not change our beliefs +about how X is distributed. + +So whatever we expected about X +is going to remain true even + +after we are told something +about Y. + +So let's look at +some pictures. + +Here is what the joint +PDF might look like. + +Here we've got our +x and y-axis. + +And if you want to calculate the +probability of a certain + +event, what you do is you look +at that event and you see how + +much of that mass is sitting +on top of that event. + +Now let's start slicing. + +Let's fix a value of x and look +along that slice where we + +obtain this function. + +Now what does that slice do? + +That slice tells us for that +particular x what the possible + +values of y are going to be +and how likely they are. + +If we integrate over all +y's, what do we get? + +Integrating over all y's just +gives us the marginal density + +of X. It's the calculation +that we did here. + +By integrating over all y's, we +find the marginal density + +of X. So the total area under +that slice gives us the + +marginal density of X. And by +looking at the different + +slices, we find how likely the +different values of x are + +going to be. + +How about the conditional? + +If we're interested in the +conditional of Y given X, how + +would you think about it? + +This refers to a universe where +we are told that capital + +X takes on a specific value. + +So we put ourselves in +the universe where + +this line has happened. + +There's still possible values +of y that can happen. + +And this shape kind of tells us +the relative likelihoods of + +the different y's. + +And this is indeed going to be +the shape of the conditional + +distribution of Y given +that X has occurred. + +On the other hand, the +conditional distribution must + +add up to 1. + +So the total probability over +all of the different y's in + +this universe, that +total probability + +should be equal to 1. + +Here it's not equal to 1. + +The total area is the +marginal density. + +To make it equal to 1, we need +to divide by the marginal + +density, which is basically to +renormalize this shape so that + +the total area under that slice, +under that shape, is + +equal to 1. + +So we start with the joint. + +We take the slices. + +And then we adjust the slices +so that every slice has an + +area underneath equal to 1. + +And this gives us +the conditional. + +So for example, down here-- + +you can not even see it +in this diagram-- + +but after you renormalize it +so that its total area is + +equal to 1, you get this sort of +narrow spike that goes up. + +And so this is a plot of the +conditional distributions that + +you get for the different +values of x. + +Given a particular value of x, +you're going to get this + +certain conditional +distribution. + +So this picture is worth about +as much as anything else in + +this particular chapter. + +Make sure you kind of understand +exactly all these + +pieces of the picture. + +And finally, let's go, in the +remaining time, through an + +example where we're going to +throw in the bucket all the + +concepts and notations that +we have introduced so far. + +So the example is as follows. + +We start with a stick that +has a certain length. + +And we break it a completely +random location. + +And-- + +yes, this 1 should be l. + +OK. + +So it has length l. + +And we're going to break +it at the random place. + +And we call that random place +where we break it, we call it + +X. + +X can be anywhere, uniform +distribution. + +So this means that X has a +density that goes from 0 to l. + +I guess this capital L is +supposed to be the same as the + +lower-case l. + +So that's the density of X. And +since the density needs to + +integrate to 1, the height of +that density has to be 1/l. + +Now, having broken the stick +and given that we are left + +with this piece of the stick, +I'm now going to break it + +again at a completely random +place, meaning I'm going to + +choose a point where I break it +uniformly over the length + +of the stick. + +What does this mean? + +And let's call Y the location +where I break it. + +So Y is going to range +between 0 and x. + +x is the stick that +I'm left with. + +So I'm going to break it +somewhere in between. + +So I pick a y between 0 and x. + +And of course, x +is less than l. + +And I'm going to +break it there. + +So y is uniform between +0 and x. + +What does that mean, that the +density of y, given that you + +have already told me x, ranges +from 0 to little x? + +If I told you that the first +break happened at a particular + +x, then y can only range +over this interval. + +And I'm assuming a uniform + +distribution over that interval. + +So we have this kind of shape. + +And that fixes for +us the height of + +the conditional density. + +So what's the joint density of +those two random variables? + +By the definition of conditional +densities, the + +conditional was defined as the +ratio of this divided by that. + +So we can find the joint density +by taking the marginal + +and then multiplying +by the conditional. + +This is the same formula as +in the discrete case. + +This is our very familiar +multiplication rule, but + +adjusted to the case of +continuous random variables. + +So Ps become Fs. + +OK. + +So we do have a formula +for this. + +What is it? + +It's 1/l-- + +that's the density of X -- + +times 1/x, which is the +conditional density of Y. This + +is the formula for the +joint density. + +But we must be careful. + +This is a formula that's +not valid anywhere. + +It's only valid for the x's +and y's that are possible. + +And the x's and y's that are +possible are given by these + +inequalities. + +So x can range from 0 to +l, and y can only be + +smaller than x. + +So this is the formula +for the density on + +this part of our space. + +The density is 0 +anywhere else. + +So what does it look like? + +It's basically a 1/x function. + +So it's sort of constant +along that dimension. + +But as x goes to 0, your +density goes up and + +can even blow up. + +It sort of looks like a sail +that's raised and somewhat + +curved and has a point up +there going to infinity. + +So this is the joint density. + +Now once you have in your hands +a joint density, then + +you can answer in principle +any problem. + +It's just a matter of plugging +in and doing computations. + +How about calculating something +like a conditional + +expectation of Y given +a value of x? + +OK. + +That's a concept we have +not defined so far. + +But how should we define it? + +Means the reasonable thing. + +We'll define it the same way +as ordinary expectations + +except that since we're given +some conditioning information, + +we should use the probability +distribution that applies to + +that particular situation. + +So in a situation where we are +told the value of x, the + +distribution that applies is the +conditional distribution + +of Y. So it's going to be the +conditional density of Y given + +the value of x. + +Now, we know what this is. + +It's given by 1/x. + +So we need to integrate +y times 1/x dy. + +And what should we +integrate over? + +Well, given the value of x, y +can only range from 0 to x. + +So this is what we get. + +And you do your integral, and +you get that this is x/2. + +Is it a surprise? + +It shouldn't be. + +This is just the expected value +of Y in a universe where + +X has been realized and Y is +given by this distribution. + +Y is uniform between 0 and x. + +The expected value of Y should +be the midpoint of this + +interval, which is x/2. + +Now let's do fancier stuff. + +Since we have the joint +distribution, we should be + +able to calculate +the marginal. + +What is the distribution of Y? + +After breaking the stick twice, +how big is the little + +piece that I'm left with? + +How do we find this? + +To find the marginal, we just +take the joint and integrate + +out the variable that +we don't want. + +A particular y can happen +in many ways. + +It can happen together +with any x. + +So we consider all the possible +x's that can go + +together with this y and average +over all those x's. + +So we plug in the formula for +the joint density from the + +previous slide. + +We know that it's 1/lx. + +And what's the range +of the x's? + +So to find the density of Y for +a particular y up here, + +I'm going to integrate +over x's. + +The density is 0 +here and there. + +The density is nonzero +only in this part. + +So I need to integrate over x's +going from here to there. + +So what's the "here"? + +This line goes up at +the slope of 1. + +So this is the line +x equals y. + +So if I fix y, it means that +my integral starts from a + +value of x that is +also equal to y. + +So where the integral starts +from is at x equals y. + +And it goes all the way until +the end of the length of our + +stick, which is l. + +So we need to integrate +from little y up to l. + +So that's something that +almost always comes up. + +It's not enough to have just +this formula for integrating + +the joint density. + +You need to keep track +of different regions. + +And if the joint density is 0 +in some regions, then you + +exclude those regions from +the range of integration. + +So the range of integration is +only over those values where + +the particular formula is valid, +the places where the + +joint density is nonzero. + +All right. + +The integral of 1/x dx, that +gives you a logarithm. + +So we evaluate this integral, +and we get an + +expression of this kind. + +So the density of Y has a +somewhat unexpected shape. + +So it's a logarithmic +function. + +And it goes this way. + +It's for y going all +the way to l. + +When y is equal to l, the +logarithm of 1 is equal to 0. + +But when y approaches 0, +logarithm of something big + +blows up, and we get a +shape of this form. + +OK. + +Finally, we can calculate the +expected value of Y. And we + +can do this by using the +definition of the expectation. + +So integral of y times +the density of y. + +We already found what that +density is, so we + +can plug it in here. + +And we're integrating over +the range of possible + +y's, from 0 to l. + +Now this involves the integral +for y log y, which I'm sure + +you have encountered in your +calculus classes but maybe do + +not remember how to do it. + +In any case, you look it +up in some integral + +tables or do it by parts. + +And you get the final +answer of l/4. + +And at this point, you say, +that's a really simple answer. + +Shouldn't I have expected +it to be l/4? + +I guess, yes. + +I mean, when you break it once, +the expected value of + +what you are left with is going +to be 1/2 of what you + +started with. + +When you break it the next time, +the expected length of + +what you're left with should be +1/2 of the piece that you + +are now breaking. + +So each time that you break it +at random, you expected it to + +become smaller by +a factor of 1/2. + +So if you break it twice, you +are left something that's + +expected to be 1/4. + +This is reasoning on the +average, which happens to give + +you the right answer +in this case. + +But again, there's the warning +that reasoning on the average + +doesn't always give you +the right answer. + +So be careful about doing +arguments of this type. + +Very good. + +See you on Wednesday. \ No newline at end of file diff --git a/D7nf7pKddwM.txt b/D7nf7pKddwM.txt new file mode 100644 index 0000000000000000000000000000000000000000..ae63927427b8c247d2c1cf705e3b5c3322dec446 --- /dev/null +++ b/D7nf7pKddwM.txt @@ -0,0 +1,763 @@ +align:start position:0% + +welcome back to recitation uh in this + + align:start position:0% +welcome back to recitation uh in this + + + align:start position:0% +welcome back to recitation uh in this +segment I'm going to actually show uh + + align:start position:0% +segment I'm going to actually show uh + + + align:start position:0% +segment I'm going to actually show uh +well you're actually going to show the + + align:start position:0% +well you're actually going to show the + + + align:start position:0% +well you're actually going to show the +derivative of tangent X using the + + align:start position:0% +derivative of tangent X using the + + + align:start position:0% +derivative of tangent X using the +quotient rule so what what I'd like you + + align:start position:0% +quotient rule so what what I'd like you + + + align:start position:0% +quotient rule so what what I'd like you +to do I I wanted to remind you of what + + align:start position:0% +to do I I wanted to remind you of what + + + align:start position:0% +to do I I wanted to remind you of what +the quotient rule is so u and v are + + align:start position:0% +the quotient rule is so u and v are + + + align:start position:0% +the quotient rule is so u and v are +functions of X we want to take the + + align:start position:0% +functions of X we want to take the + + + align:start position:0% +functions of X we want to take the +derivative of U / V I've written the + + align:start position:0% +derivative of U / V I've written the + + + align:start position:0% +derivative of U / V I've written the +formula that you were given in class + + align:start position:0% +formula that you were given in class + + + align:start position:0% +formula that you were given in class +uh for this and I'm I'm asking for you + + align:start position:0% +uh for this and I'm I'm asking for you + + + align:start position:0% +uh for this and I'm I'm asking for you +to take DDX of tangent X using the + + align:start position:0% +to take DDX of tangent X using the + + + align:start position:0% +to take DDX of tangent X using the +quotient Rule and the hint I will give + + align:start position:0% +quotient Rule and the hint I will give + + + align:start position:0% +quotient Rule and the hint I will give +you is the reason we can obviously use + + align:start position:0% +you is the reason we can obviously use + + + align:start position:0% +you is the reason we can obviously use +the quotient rule is because tangent X + + align:start position:0% +the quotient rule is because tangent X + + + align:start position:0% +the quotient rule is because tangent X +is equal to a quotient of two functions + + align:start position:0% +is equal to a quotient of two functions + + + align:start position:0% +is equal to a quotient of two functions +of X it's sin x / cosine of x so I'm + + align:start position:0% +of X it's sin x / cosine of x so I'm + + + align:start position:0% +of X it's sin x / cosine of x so I'm +going to give you a minute to work this + + align:start position:0% +going to give you a minute to work this + + + align:start position:0% +going to give you a minute to work this +out for yourself and then when we come + + align:start position:0% +out for yourself and then when we come + + + align:start position:0% +out for yourself and then when we come +back I will do it uh for + + align:start position:0% + + + + align:start position:0% + +you okay so we want to find the + + align:start position:0% +you okay so we want to find the + + + align:start position:0% +you okay so we want to find the +derivative of tangent X so let me let me + + align:start position:0% +derivative of tangent X so let me let me + + + align:start position:0% +derivative of tangent X so let me let me +work on this side of the board so I'm + + align:start position:0% +work on this side of the board so I'm + + + align:start position:0% +work on this side of the board so I'm +actually going to take + + align:start position:0% + + + + align:start position:0% + +DDX of + + align:start position:0% +DDX of + + + align:start position:0% +DDX of +sinx divid cosine of + + align:start position:0% +sinx divid cosine of + + + align:start position:0% +sinx divid cosine of +x okay so I in this case sin x is U + + align:start position:0% +x okay so I in this case sin x is U + + + align:start position:0% +x okay so I in this case sin x is U +cosine X is V so using my quotient rule + + align:start position:0% +cosine X is V so using my quotient rule + + + align:start position:0% +cosine X is V so using my quotient rule +I know that first I have to take the + + align:start position:0% +I know that first I have to take the + + + align:start position:0% +I know that first I have to take the +derivative of sin x that's cosine X and + + align:start position:0% +derivative of sin x that's cosine X and + + + align:start position:0% +derivative of sin x that's cosine X and +then I multiply it by the denominator + + align:start position:0% +then I multiply it by the denominator + + + align:start position:0% +then I multiply it by the denominator +the V which is cosine X so my first term + + align:start position:0% +the V which is cosine X so my first term + + + align:start position:0% +the V which is cosine X so my first term +in the numerator + + align:start position:0% +in the numerator + + + align:start position:0% +in the numerator +is cosine 2 x again one cosine X comes + + align:start position:0% +is cosine 2 x again one cosine X comes + + + align:start position:0% +is cosine 2 x again one cosine X comes +from the derivative of sin x one cosine + + align:start position:0% +from the derivative of sin x one cosine + + + align:start position:0% +from the derivative of sin x one cosine +X is the V it's the cosine X in the + + align:start position:0% +X is the V it's the cosine X in the + + + align:start position:0% +X is the V it's the cosine X in the +denominator then I have to subtract V + + align:start position:0% +denominator then I have to subtract V + + + align:start position:0% +denominator then I have to subtract V +Prime U the derivative of cosine X is + + align:start position:0% +Prime U the derivative of cosine X is + + + align:start position:0% +Prime U the derivative of cosine X is +negative sinx I'll actually just write + + align:start position:0% +negative sinx I'll actually just write + + + align:start position:0% +negative sinx I'll actually just write +that one + + align:start position:0% +that one + + + align:start position:0% +that one +down and then I bring the U along for + + align:start position:0% +down and then I bring the U along for + + + align:start position:0% +down and then I bring the U along for +the ride so I multiply by sin x here + + align:start position:0% +the ride so I multiply by sin x here + + + align:start position:0% +the ride so I multiply by sin x here +and then I take v^2 in the denominator + + align:start position:0% +and then I take v^2 in the denominator + + + align:start position:0% +and then I take v^2 in the denominator +from the formula V again is cosine X so + + align:start position:0% +from the formula V again is cosine X so + + + align:start position:0% +from the formula V again is cosine X so +I take cosine 2 x in the denominator now + + align:start position:0% +I take cosine 2 x in the denominator now + + + align:start position:0% +I take cosine 2 x in the denominator now +this at this point is a little bit messy + + align:start position:0% +this at this point is a little bit messy + + + align:start position:0% +this at this point is a little bit messy +but the nice thing is that we can use + + align:start position:0% +but the nice thing is that we can use + + + align:start position:0% +but the nice thing is that we can use +some trigonometric identities to + + align:start position:0% +some trigonometric identities to + + + align:start position:0% +some trigonometric identities to +simplify this so let me first write out + + align:start position:0% +simplify this so let me first write out + + + align:start position:0% +simplify this so let me first write out +what it is a little more clearly minus a + + align:start position:0% +what it is a little more clearly minus a + + + align:start position:0% +what it is a little more clearly minus a +negative gives you a positive and then + + align:start position:0% +negative gives you a positive and then + + + align:start position:0% +negative gives you a positive and then +here I get sin x * sin x so I get sin^2 + + align:start position:0% +here I get sin x * sin x so I get sin^2 + + + align:start position:0% +here I get sin x * sin x so I get sin^2 +X and then I keep div divid by cosine 2 + + align:start position:0% +X and then I keep div divid by cosine 2 + + + align:start position:0% +X and then I keep div divid by cosine 2 +x now at this point some of you might + + align:start position:0% +x now at this point some of you might + + + align:start position:0% +x now at this point some of you might +have divided by cosine squ X here and + + align:start position:0% +have divided by cosine squ X here and + + + align:start position:0% +have divided by cosine squ X here and +gotten one and divided by cosine squ X + + align:start position:0% +gotten one and divided by cosine squ X + + + align:start position:0% +gotten one and divided by cosine squ X +here and gotten tangent squ X and then + + align:start position:0% +here and gotten tangent squ X and then + + + align:start position:0% +here and gotten tangent squ X and then +from there you uh you could simplify to + + align:start position:0% +from there you uh you could simplify to + + + align:start position:0% +from there you uh you could simplify to +another trigonometric function I'm going + + align:start position:0% +another trigonometric function I'm going + + + align:start position:0% +another trigonometric function I'm going +to go straight a different way to show + + align:start position:0% +to go straight a different way to show + + + align:start position:0% +to go straight a different way to show +you what that actually also equals so + + align:start position:0% +you what that actually also equals so + + + align:start position:0% +you what that actually also equals so +there at this point I want to stress + + align:start position:0% +there at this point I want to stress + + + align:start position:0% +there at this point I want to stress +there sort of two ways you can you can + + align:start position:0% +there sort of two ways you can you can + + + align:start position:0% +there sort of two ways you can you can +get to the same place but I'm going to + + align:start position:0% +get to the same place but I'm going to + + + align:start position:0% +get to the same place but I'm going to +use the fact that the numerator is is a + + align:start position:0% +use the fact that the numerator is is a + + + align:start position:0% +use the fact that the numerator is is a +very nice trigonometric identity that we + + align:start position:0% +very nice trigonometric identity that we + + + align:start position:0% +very nice trigonometric identity that we +know we know cosine s x plus sin s x + + align:start position:0% +know we know cosine s x plus sin s x + + + align:start position:0% +know we know cosine s x plus sin s x +always equals 1 so this is quite lovely + + align:start position:0% +always equals 1 so this is quite lovely + + + align:start position:0% +always equals 1 so this is quite lovely +the numerator simplifies to + + align:start position:0% +the numerator simplifies to + + + align:start position:0% +the numerator simplifies to +one the + + align:start position:0% +one the + + + align:start position:0% +one the +denominator stays cosine squ X what is + + align:start position:0% +denominator stays cosine squ X what is + + + align:start position:0% +denominator stays cosine squ X what is +this function one over cosine X is + + align:start position:0% +this function one over cosine X is + + + align:start position:0% +this function one over cosine X is +actually secant x so if you need at this + + align:start position:0% +actually secant x so if you need at this + + + align:start position:0% +actually secant x so if you need at this +point to + + align:start position:0% +point to + + + align:start position:0% +point to +rewrite the whole thing like this right + + align:start position:0% +rewrite the whole thing like this right + + + align:start position:0% +rewrite the whole thing like this right +1 squ is one and in the denominator we + + align:start position:0% +1 squ is one and in the denominator we + + + align:start position:0% +1 squ is one and in the denominator we +still get cosine X this tells you that + + align:start position:0% +still get cosine X this tells you that + + + align:start position:0% +still get cosine X this tells you that +uh that 1 cosine X is actually just + + align:start position:0% +uh that 1 cosine X is actually just + + + align:start position:0% +uh that 1 cosine X is actually just +equal to SEC + + align:start position:0% +equal to SEC + + + align:start position:0% +equal to SEC +X so again what I want to point out is + + align:start position:0% +X so again what I want to point out is + + + align:start position:0% +X so again what I want to point out is +we've now taken the derivative of + + align:start position:0% +we've now taken the derivative of + + + align:start position:0% +we've now taken the derivative of +tangent X and we got that that's secant + + align:start position:0% +tangent X and we got that that's secant + + + align:start position:0% +tangent X and we got that that's secant +s x Now using this quotient rule you can + + align:start position:0% +s x Now using this quotient rule you can + + + align:start position:0% +s x Now using this quotient rule you can +do the same kind of thing with cotangent + + align:start position:0% +do the same kind of thing with cotangent + + + align:start position:0% +do the same kind of thing with cotangent +x with cosecant x with secant x you can + + align:start position:0% +x with cosecant x with secant x you can + + + align:start position:0% +x with cosecant x with secant x you can +find all these derivatives of these + + align:start position:0% +find all these derivatives of these + + + align:start position:0% +find all these derivatives of these +trigonometric functions using the + + align:start position:0% +trigonometric functions using the + + + align:start position:0% +trigonometric functions using the +quotient rule um so if you want to know + + align:start position:0% +quotient rule um so if you want to know + + + align:start position:0% +quotient rule um so if you want to know +what the derivative of SEC X is you + + align:start position:0% +what the derivative of SEC X is you + + + align:start position:0% +what the derivative of SEC X is you +should take DDX of 1 / cosine X and use + + align:start position:0% +should take DDX of 1 / cosine X and use + + + align:start position:0% +should take DDX of 1 / cosine X and use +the quotient rule or in fact the chain + + align:start position:0% +the quotient rule or in fact the chain + + + align:start position:0% +the quotient rule or in fact the chain +rule would work well there also um to + + align:start position:0% +rule would work well there also um to + + + align:start position:0% +rule would work well there also um to +find that derivative so we are building + + align:start position:0% +find that derivative so we are building + + + align:start position:0% +find that derivative so we are building +up uh the number of derivatives we can + + align:start position:0% +up uh the number of derivatives we can + + + align:start position:0% +up uh the number of derivatives we can +find using these different rules so + + align:start position:0% +find using these different rules so + + + align:start position:0% +find using these different rules so +we'll stop there \ No newline at end of file diff --git a/DGoILxx9KsE.txt b/DGoILxx9KsE.txt new file mode 100644 index 0000000000000000000000000000000000000000..8de4af7a93e76802206aafd06cf50edaec63f915 --- /dev/null +++ b/DGoILxx9KsE.txt @@ -0,0 +1,12592 @@ +align:start position:0% + +let me remind you from the reading list + + align:start position:0% +let me remind you from the reading list + + + align:start position:0% +let me remind you from the reading list +where we are + + align:start position:0% +where we are + + + align:start position:0% +where we are +we did the introductory lecture of + + align:start position:0% +we did the introductory lecture of + + + align:start position:0% +we did the introductory lecture of +course about economic science + + align:start position:0% +course about economic science + + + align:start position:0% +course about economic science +and + + align:start position:0% +and + + + align:start position:0% +and +last time we did our first nuts and + + align:start position:0% +last time we did our first nuts and + + + align:start position:0% +last time we did our first nuts and +bolts lecture on preferences consumer + + align:start position:0% +bolts lecture on preferences consumer + + + align:start position:0% +bolts lecture on preferences consumer +theory + + align:start position:0% +theory + + + align:start position:0% +theory +with the associated uh + + align:start position:0% +with the associated uh + + + align:start position:0% +with the associated uh +starred readings + + align:start position:0% +starred readings + + + align:start position:0% +starred readings +and + + align:start position:0% +and + + + align:start position:0% +and +today we're going to do + + align:start position:0% +today we're going to do + + + align:start position:0% +today we're going to do +more the way we ended the last class on + + align:start position:0% +more the way we ended the last class on + + + align:start position:0% +more the way we ended the last class on +consumer behavior + + align:start position:0% +consumer behavior + + + align:start position:0% +consumer behavior +i'm showing this + + align:start position:0% +i'm showing this + + + align:start position:0% +i'm showing this +reading list because i just want to + + align:start position:0% +reading list because i just want to + + + align:start position:0% +reading list because i just want to +remind you that these starred articles + + align:start position:0% +remind you that these starred articles + + + align:start position:0% +remind you that these starred articles +do exist the nicholson and schneider + + align:start position:0% +do exist the nicholson and schneider + + + align:start position:0% +do exist the nicholson and schneider +chapter 5 from which this is drawn + + align:start position:0% +chapter 5 from which this is drawn + + + align:start position:0% +chapter 5 from which this is drawn +although not entirely and + + align:start position:0% +although not entirely and + + + align:start position:0% +although not entirely and +also this jensen and miller paper which + + align:start position:0% +also this jensen and miller paper which + + + align:start position:0% +also this jensen and miller paper which +i will say a few words about today + + align:start position:0% +i will say a few words about today + + + align:start position:0% +i will say a few words about today +because it fits into this lecture but + + align:start position:0% +because it fits into this lecture but + + + align:start position:0% +because it fits into this lecture but +also as i probably mentioned too many + + align:start position:0% +also as i probably mentioned too many + + + align:start position:0% +also as i probably mentioned too many +times that's also + + align:start position:0% +times that's also + + + align:start position:0% +times that's also +a big part of your first + + align:start position:0% +a big part of your first + + + align:start position:0% +a big part of your first +problem set and + + align:start position:0% +problem set and + + + align:start position:0% +problem set and +involves getting that paper reading the + + align:start position:0% +involves getting that paper reading the + + + align:start position:0% +involves getting that paper reading the +yellow markings as highlights accessing + + align:start position:0% +yellow markings as highlights accessing + + + align:start position:0% +yellow markings as highlights accessing +the data that these guys used + + align:start position:0% +the data that these guys used + + + align:start position:0% +the data that these guys used +and running through some of their + + align:start position:0% +and running through some of their + + + align:start position:0% +and running through some of their +calculations + + align:start position:0% +calculations + + + align:start position:0% +calculations +okay so that's the + + align:start position:0% +okay so that's the + + + align:start position:0% +okay so that's the +part of the starred readings for this + + align:start position:0% +part of the starred readings for this + + + align:start position:0% +part of the starred readings for this +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +so in terms of the study guide consumer + + align:start position:0% +so in terms of the study guide consumer + + + align:start position:0% +so in terms of the study guide consumer +theory + + align:start position:0% +theory + + + align:start position:0% +theory +as i was alerting you last time + + align:start position:0% +as i was alerting you last time + + + align:start position:0% +as i was alerting you last time +there's a pretty good thorough review of + + align:start position:0% +there's a pretty good thorough review of + + + align:start position:0% +there's a pretty good thorough review of +what you should have learned or are + + align:start position:0% +what you should have learned or are + + + align:start position:0% +what you should have learned or are +learning from the topic of last time and + + align:start position:0% +learning from the topic of last time and + + + align:start position:0% +learning from the topic of last time and +i i will not go through all of this but + + align:start position:0% +i i will not go through all of this but + + + align:start position:0% +i i will not go through all of this but +i will ask a few questions get a few + + align:start position:0% +i will ask a few questions get a few + + + align:start position:0% +i will ask a few questions get a few +volunteers uh maybe even call on a + + align:start position:0% +volunteers uh maybe even call on a + + + align:start position:0% +volunteers uh maybe even call on a +couple of you so + + align:start position:0% +couple of you so + + + align:start position:0% +couple of you so +this one give a plausible example of a + + align:start position:0% +this one give a plausible example of a + + + align:start position:0% +this one give a plausible example of a +commodity point that could not be in + + align:start position:0% +commodity point that could not be in + + + align:start position:0% +commodity point that could not be in +typical consumption set + + align:start position:0% +typical consumption set + + + align:start position:0% +typical consumption set +and i'll take volunteers on that it's + + align:start position:0% +and i'll take volunteers on that it's + + + align:start position:0% +and i'll take volunteers on that it's +partly + + align:start position:0% +partly + + + align:start position:0% +partly +remembering the slide where i showed + + align:start position:0% +remembering the slide where i showed + + + align:start position:0% +remembering the slide where i showed +examples of consumption says does anyone + + align:start position:0% +examples of consumption says does anyone + + + align:start position:0% +examples of consumption says does anyone +remember + + align:start position:0% +remember + + + align:start position:0% +remember +this question + + align:start position:0% +this question + + + align:start position:0% +this question +yes + + align:start position:0% +yes + + + align:start position:0% +yes +uh one in feasible consumption set is + + align:start position:0% +uh one in feasible consumption set is + + + align:start position:0% +uh one in feasible consumption set is +like consuming 25 hours in a day or + + align:start position:0% +like consuming 25 hours in a day or + + + align:start position:0% +like consuming 25 hours in a day or +something like that + + align:start position:0% +something like that + + + align:start position:0% +something like that +that's good + + align:start position:0% +that's good + + + align:start position:0% +that's good +yup the that was one of the diagrams + + align:start position:0% +yup the that was one of the diagrams + + + align:start position:0% +yup the that was one of the diagrams +where the + + align:start position:0% +where the + + + align:start position:0% +where the +amount of leisure available for work or + + align:start position:0% +amount of leisure available for work or + + + align:start position:0% +amount of leisure available for work or +what or leisure the sum could not exceed + + align:start position:0% +what or leisure the sum could not exceed + + + align:start position:0% +what or leisure the sum could not exceed +25. + + align:start position:0% +25. + + + align:start position:0% +25. +there was another one which you might + + align:start position:0% +there was another one which you might + + + align:start position:0% +there was another one which you might +not have thought of given the way this + + align:start position:0% +not have thought of given the way this + + + align:start position:0% +not have thought of given the way this +is worded + + align:start position:0% +is worded + + + align:start position:0% +is worded +which is consumption of bread in new + + align:start position:0% +which is consumption of bread in new + + + align:start position:0% +which is consumption of bread in new +york at noon and consumption in boston + + align:start position:0% +york at noon and consumption in boston + + + align:start position:0% +york at noon and consumption in boston +at noon of bread + + align:start position:0% +at noon of bread + + + align:start position:0% +at noon of bread +and uh there was you're not allowed to + + align:start position:0% +and uh there was you're not allowed to + + + align:start position:0% +and uh there was you're not allowed to +have + + align:start position:0% +have + + + align:start position:0% +have +bread in the interior because you can't + + align:start position:0% +bread in the interior because you can't + + + align:start position:0% +bread in the interior because you can't +consume simultaneously in both new york + + align:start position:0% +consume simultaneously in both new york + + + align:start position:0% +consume simultaneously in both new york +and boston so that was another example + + align:start position:0% +and boston so that was another example + + + align:start position:0% +and boston so that was another example +but your your answer was great + + align:start position:0% +but your your answer was great + + + align:start position:0% +but your your answer was great +so can someone volunteer to give me + + align:start position:0% +so can someone volunteer to give me + + + align:start position:0% +so can someone volunteer to give me +the definition of local non-satiation + + align:start position:0% +the definition of local non-satiation + + + align:start position:0% +the definition of local non-satiation +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um + + align:start position:0% +um + + + align:start position:0% +um +that means that there is + + align:start position:0% +that means that there is + + + align:start position:0% +that means that there is +in that so if you + + align:start position:0% +in that so if you + + + align:start position:0% +in that so if you +have a bundle + + align:start position:0% +have a bundle + + + align:start position:0% +have a bundle +in um in any neighborhood of that bundle + + align:start position:0% +in um in any neighborhood of that bundle + + + align:start position:0% +in um in any neighborhood of that bundle +there is + + align:start position:0% +there is + + + align:start position:0% +there is +some other bundle that's referred to the + + align:start position:0% +some other bundle that's referred to the + + + align:start position:0% +some other bundle that's referred to the +bundle you originally had yeah there are + + align:start position:0% +bundle you originally had yeah there are + + + align:start position:0% +bundle you originally had yeah there are +no bliss points + + align:start position:0% +no bliss points + + + align:start position:0% +no bliss points +that's right + + align:start position:0% +that's right + + + align:start position:0% +that's right +um + + align:start position:0% +um + + + align:start position:0% +um +that's an excellent answer + + align:start position:0% +that's an excellent answer + + + align:start position:0% +that's an excellent answer +yeah for i can't remember whether we did + + align:start position:0% +yeah for i can't remember whether we did + + + align:start position:0% +yeah for i can't remember whether we did +x or y but for + + align:start position:0% +x or y but for + + + align:start position:0% +x or y but for +for any x + + align:start position:0% +for any x + + + align:start position:0% +for any x +in the consumption set + + align:start position:0% +in the consumption set + + + align:start position:0% +in the consumption set +there's some other y + + align:start position:0% +there's some other y + + + align:start position:0% +there's some other y +uh no matter how close we are to x + + align:start position:0% +uh no matter how close we are to x + + + align:start position:0% +uh no matter how close we are to x +which is preferred + + align:start position:0% +which is preferred + + + align:start position:0% +which is preferred +to x and well and y has to be in the + + align:start position:0% +to x and well and y has to be in the + + + align:start position:0% +to x and well and y has to be in the +consumption set so both things have to + + align:start position:0% +consumption set so both things have to + + + align:start position:0% +consumption set so both things have to +be true it has to be available in this + + align:start position:0% +be true it has to be available in this + + + align:start position:0% +be true it has to be available in this +little + + align:start position:0% +little + + + align:start position:0% +little +ball or circle around x and it has to be + + align:start position:0% +ball or circle around x and it has to be + + + align:start position:0% +ball or circle around x and it has to be +preferred + + align:start position:0% + + + + align:start position:0% + +and you gave a good + + align:start position:0% +and you gave a good + + + align:start position:0% +and you gave a good +counter example if there were a bliss + + align:start position:0% +counter example if there were a bliss + + + align:start position:0% +counter example if there were a bliss +point that means + + align:start position:0% +point that means + + + align:start position:0% +point that means +there's something that is + + align:start position:0% +there's something that is + + + align:start position:0% +there's something that is +maximal utility + + align:start position:0% +maximal utility + + + align:start position:0% +maximal utility +among all possible points so if we do + + align:start position:0% +among all possible points so if we do + + + align:start position:0% +among all possible points so if we do +a circle around that everything else + + align:start position:0% +a circle around that everything else + + + align:start position:0% +a circle around that everything else +would be inferior + + align:start position:0% + + + + align:start position:0% + +if if you went beyond the bliss point + + align:start position:0% +if if you went beyond the bliss point + + + align:start position:0% +if if you went beyond the bliss point +northeast of it + + align:start position:0% +northeast of it + + + align:start position:0% +northeast of it +you have too much of all the goods + + align:start position:0% +you have too much of all the goods + + + align:start position:0% +you have too much of all the goods +but then ironically + + align:start position:0% +but then ironically + + + align:start position:0% +but then ironically +you also have local non-satiation + + align:start position:0% +you also have local non-satiation + + + align:start position:0% +you also have local non-satiation +because + + align:start position:0% +because + + + align:start position:0% +because +given any point x + + align:start position:0% +given any point x + + + align:start position:0% +given any point x +uh + + align:start position:0% +uh + + + align:start position:0% +uh +there's another point y which involves + + align:start position:0% +there's another point y which involves + + + align:start position:0% +there's another point y which involves +less than both goods + + align:start position:0% +less than both goods + + + align:start position:0% +less than both goods +that would be strictly preferred because + + align:start position:0% +that would be strictly preferred because + + + align:start position:0% +that would be strictly preferred because +you're moving to the bliss point + + align:start position:0% +you're moving to the bliss point + + + align:start position:0% +you're moving to the bliss point +so anyway the the point of this little + + align:start position:0% +so anyway the the point of this little + + + align:start position:0% +so anyway the the point of this little +discussion is that local + + align:start position:0% +discussion is that local + + + align:start position:0% +discussion is that local +non-satiation and global non-satiation + + align:start position:0% +non-satiation and global non-satiation + + + align:start position:0% +non-satiation and global non-satiation +are + + align:start position:0% +are + + + align:start position:0% +are +two different things + + align:start position:0% +two different things + + + align:start position:0% +two different things +thank you okay let's + + align:start position:0% +thank you okay let's + + + align:start position:0% +thank you okay let's +what does it mean for preference + + align:start position:0% +what does it mean for preference + + + align:start position:0% +what does it mean for preference +relation to be represented by a utility + + align:start position:0% +relation to be represented by a utility + + + align:start position:0% +relation to be represented by a utility +function + + align:start position:0% +function + + + align:start position:0% +function +give a preference relation given a + + align:start position:0% +give a preference relation given a + + + align:start position:0% +give a preference relation given a +preference relation is the utility + + align:start position:0% +preference relation is the utility + + + align:start position:0% +preference relation is the utility +function that represents it unique + + align:start position:0% +function that represents it unique + + + align:start position:0% +function that represents it unique +yes or no + + align:start position:0% +yes or no + + + align:start position:0% +yes or no +and explain + + align:start position:0% + + + + align:start position:0% + +yeah so um + + align:start position:0% +yeah so um + + + align:start position:0% +yeah so um +so so we say that a utility function + + align:start position:0% +so so we say that a utility function + + + align:start position:0% +so so we say that a utility function +sort of represents a preference if + + align:start position:0% +sort of represents a preference if + + + align:start position:0% +sort of represents a preference if +for example for any consumption bundle + + align:start position:0% +for example for any consumption bundle + + + align:start position:0% +for example for any consumption bundle +um + + align:start position:0% +um + + + align:start position:0% +um +x any two consumption bundles x and y if + + align:start position:0% +x any two consumption bundles x and y if + + + align:start position:0% +x any two consumption bundles x and y if +if um x is preferred to y then u of x is + + align:start position:0% +if um x is preferred to y then u of x is + + + align:start position:0% +if um x is preferred to y then u of x is +uh + + align:start position:0% +uh + + + align:start position:0% +uh +greater than u of y + + align:start position:0% +greater than u of y + + + align:start position:0% +greater than u of y +um + + align:start position:0% +um + + + align:start position:0% +um +and the utility function is not unique + + align:start position:0% +and the utility function is not unique + + + align:start position:0% +and the utility function is not unique +um it just has to respect the given + + align:start position:0% +um it just has to respect the given + + + align:start position:0% +um it just has to respect the given +ordering of the preferences so we could + + align:start position:0% +ordering of the preferences so we could + + + align:start position:0% +ordering of the preferences so we could +have like u and if we could have u or u + + align:start position:0% +have like u and if we could have u or u + + + align:start position:0% +have like u and if we could have u or u +squared or n cubed and all those would + + align:start position:0% +squared or n cubed and all those would + + + align:start position:0% +squared or n cubed and all those would +work + + align:start position:0% +work + + + align:start position:0% +work +excellent perfect answer + + align:start position:0% + + + + align:start position:0% + +any other comments or questions about + + align:start position:0% +any other comments or questions about + + + align:start position:0% +any other comments or questions about +that + + align:start position:0% + + + + align:start position:0% + +i had a question um on this slide it had + + align:start position:0% +i had a question um on this slide it had + + + align:start position:0% +i had a question um on this slide it had +said that um it was unique only up to an + + align:start position:0% +said that um it was unique only up to an + + + align:start position:0% +said that um it was unique only up to an +order preserving transformation what + + align:start position:0% +order preserving transformation what + + + align:start position:0% +order preserving transformation what +exactly is that i guess mean + + align:start position:0% +exactly is that i guess mean + + + align:start position:0% +exactly is that i guess mean +well if you had three points + + align:start position:0% +well if you had three points + + + align:start position:0% +well if you had three points +ordering them from low to high in terms + + align:start position:0% +ordering them from low to high in terms + + + align:start position:0% +ordering them from low to high in terms +of preference relation + + align:start position:0% +of preference relation + + + align:start position:0% +of preference relation +a x1 x2 x3 + + align:start position:0% +a x1 x2 x3 + + + align:start position:0% +a x1 x2 x3 +where x3 is preferred to x2 is preferred + + align:start position:0% +where x3 is preferred to x2 is preferred + + + align:start position:0% +where x3 is preferred to x2 is preferred +to x1 + + align:start position:0% +to x1 + + + align:start position:0% +to x1 +all we need to do is assign a higher + + align:start position:0% +all we need to do is assign a higher + + + align:start position:0% +all we need to do is assign a higher +number + + align:start position:0% +number + + + align:start position:0% +number +to the best one a lower number to the + + align:start position:0% +to the best one a lower number to the + + + align:start position:0% +to the best one a lower number to the +intermediate one so something like + + align:start position:0% +intermediate one so something like + + + align:start position:0% +intermediate one so something like +you know 15 5 1 + + align:start position:0% +you know 15 5 1 + + + align:start position:0% +you know 15 5 1 +preserves the rank ordering those are + + align:start position:0% +preserves the rank ordering those are + + + align:start position:0% +preserves the rank ordering those are +utility number assignments + + align:start position:0% +utility number assignments + + + align:start position:0% +utility number assignments +but we could multiply + + align:start position:0% +but we could multiply + + + align:start position:0% +but we could multiply +by 2 and then we have + + align:start position:0% +by 2 and then we have + + + align:start position:0% +by 2 and then we have +30 10 + + align:start position:0% +30 10 + + + align:start position:0% +30 10 + + align:start position:0% + + + align:start position:0% +but we're still assigning + + align:start position:0% +but we're still assigning + + + align:start position:0% +but we're still assigning +numbers from high to low uh to preserve + + align:start position:0% +numbers from high to low uh to preserve + + + align:start position:0% +numbers from high to low uh to preserve +the same rank ordering does that help + + align:start position:0% +the same rank ordering does that help + + + align:start position:0% +the same rank ordering does that help +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +thank you okay + + align:start position:0% +thank you okay + + + align:start position:0% +thank you okay +so uh + + align:start position:0% +so uh + + + align:start position:0% +so uh +yes go on do you eventually need to i + + align:start position:0% +yes go on do you eventually need to i + + + align:start position:0% +yes go on do you eventually need to i +guess reintroduce some concept of + + align:start position:0% +guess reintroduce some concept of + + + align:start position:0% +guess reintroduce some concept of +magnitude + + align:start position:0% +magnitude + + + align:start position:0% +magnitude +or not magnitude but have something + + align:start position:0% +or not magnitude but have something + + + align:start position:0% +or not magnitude but have something +beyond disordering if you want to like + + align:start position:0% +beyond disordering if you want to like + + + align:start position:0% +beyond disordering if you want to like +start talking about gambling or expected + + align:start position:0% +start talking about gambling or expected + + + align:start position:0% +start talking about gambling or expected +value yes absolutely and we're going to + + align:start position:0% +value yes absolutely and we're going to + + + align:start position:0% +value yes absolutely and we're going to +do that in two lectures + + align:start position:0% +do that in two lectures + + + align:start position:0% +do that in two lectures +so there the + + align:start position:0% +so there the + + + align:start position:0% +so there the +utility function + + align:start position:0% +utility function + + + align:start position:0% +utility function +will + + align:start position:0% +will + + + align:start position:0% +will +the ordinal representation matters + + align:start position:0% +the ordinal representation matters + + + align:start position:0% +the ordinal representation matters +uh and and the question will be how much + + align:start position:0% +uh and and the question will be how much + + + align:start position:0% +uh and and the question will be how much +more utility do you get + + align:start position:0% +more utility do you get + + + align:start position:0% +more utility do you get +or how much less + + align:start position:0% +or how much less + + + align:start position:0% +or how much less +depending on an adverse event + + align:start position:0% +depending on an adverse event + + + align:start position:0% +depending on an adverse event +so that the curvature literally + + align:start position:0% +so that the curvature literally + + + align:start position:0% +so that the curvature literally +uh + + align:start position:0% +uh + + + align:start position:0% +uh +you know represents your willingness to + + align:start position:0% +you know represents your willingness to + + + align:start position:0% +you know represents your willingness to +take gambles + + align:start position:0% +take gambles + + + align:start position:0% +take gambles +whereas with an ordinal function a + + align:start position:0% +whereas with an ordinal function a + + + align:start position:0% +whereas with an ordinal function a +linear function is fine linear + + align:start position:0% +linear function is fine linear + + + align:start position:0% +linear function is fine linear +function when you're facing gammas means + + align:start position:0% +function when you're facing gammas means + + + align:start position:0% +function when you're facing gammas means +you're risk neutral + + align:start position:0% +you're risk neutral + + + align:start position:0% +you're risk neutral +and you just you just rank based on + + align:start position:0% +and you just you just rank based on + + + align:start position:0% +and you just you just rank based on +expected values + + align:start position:0% +expected values + + + align:start position:0% +expected values +that's all a little bit early it's a + + align:start position:0% +that's all a little bit early it's a + + + align:start position:0% +that's all a little bit early it's a +great question and we're going to get + + align:start position:0% +great question and we're going to get + + + align:start position:0% +great question and we're going to get +there in two lectures + + align:start position:0% +there in two lectures + + + align:start position:0% +there in two lectures +we have time for one more here + + align:start position:0% +we have time for one more here + + + align:start position:0% +we have time for one more here +um + + align:start position:0% + + + + align:start position:0% + +what does it mean for preferences to be + + align:start position:0% +what does it mean for preferences to be + + + align:start position:0% +what does it mean for preferences to be +homothetic + + align:start position:0% + + + + align:start position:0% + +the mrs is just depending on the ratio + + align:start position:0% +the mrs is just depending on the ratio + + + align:start position:0% +the mrs is just depending on the ratio +of two goods right + + align:start position:0% +of two goods right + + + align:start position:0% +of two goods right +not depending on the absolute quantity + + align:start position:0% +not depending on the absolute quantity + + + align:start position:0% +not depending on the absolute quantity +of each good + + align:start position:0% +of each good + + + align:start position:0% +of each good +yep perfect + + align:start position:0% +yep perfect + + + align:start position:0% +yep perfect +wow + + align:start position:0% +wow + + + align:start position:0% +wow +i'm very happy very impressed thank you + + align:start position:0% +i'm very happy very impressed thank you + + + align:start position:0% +i'm very happy very impressed thank you +all that that's tremendous okay so again + + align:start position:0% +all that that's tremendous okay so again + + + align:start position:0% +all that that's tremendous okay so again +these are just sort of ran somewhat + + align:start position:0% +these are just sort of ran somewhat + + + align:start position:0% +these are just sort of ran somewhat +randomly selected i + + align:start position:0% +randomly selected i + + + align:start position:0% +randomly selected i +do go over these before class to + + align:start position:0% +do go over these before class to + + + align:start position:0% +do go over these before class to +help me decide you know since i can't + + align:start position:0% +help me decide you know since i can't + + + align:start position:0% +help me decide you know since i can't +ask them all which one + + align:start position:0% +ask them all which one + + + align:start position:0% +ask them all which one +i would ask in class there's some of + + align:start position:0% +i would ask in class there's some of + + + align:start position:0% +i would ask in class there's some of +these that say draw a graph or + + align:start position:0% +these that say draw a graph or + + + align:start position:0% +these that say draw a graph or +so on and so forth so i know i didn't + + align:start position:0% +so on and so forth so i know i didn't + + + align:start position:0% +so on and so forth so i know i didn't +ask about those but none of them are + + align:start position:0% +ask about those but none of them are + + + align:start position:0% +ask about those but none of them are +supposed to be terribly hard + + align:start position:0% +supposed to be terribly hard + + + align:start position:0% +supposed to be terribly hard +um but it it is always a good review at + + align:start position:0% +um but it it is always a good review at + + + align:start position:0% +um but it it is always a good review at +a minimum + + align:start position:0% +a minimum + + + align:start position:0% +a minimum +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +today is a lecture + + align:start position:0% +today is a lecture + + + align:start position:0% +today is a lecture +on income and substitution effects + + align:start position:0% +on income and substitution effects + + + align:start position:0% +on income and substitution effects +or really it's about + + align:start position:0% +or really it's about + + + align:start position:0% +or really it's about +consumer maximizing behavior + + align:start position:0% +consumer maximizing behavior + + + align:start position:0% +consumer maximizing behavior +and + + align:start position:0% + + + + align:start position:0% + +so when we solve the consumer's + + align:start position:0% +so when we solve the consumer's + + + align:start position:0% +so when we solve the consumer's +utility maximization problem we get + + align:start position:0% +utility maximization problem we get + + + align:start position:0% +utility maximization problem we get +individual demand functions it should + + align:start position:0% +individual demand functions it should + + + align:start position:0% +individual demand functions it should +say function + + align:start position:0% +say function + + + align:start position:0% +say function +with an s because if there are n goods + + align:start position:0% +with an s because if there are n goods + + + align:start position:0% +with an s because if there are n goods +little n + + align:start position:0% +little n + + + align:start position:0% +little n +then there's a demand for good 1 good 2 + + align:start position:0% +then there's a demand for good 1 good 2 + + + align:start position:0% +then there's a demand for good 1 good 2 +good n and so on + + align:start position:0% +good n and so on + + + align:start position:0% +good n and so on +and what are the arguments in these + + align:start position:0% +and what are the arguments in these + + + align:start position:0% +and what are the arguments in these +demand functions + + align:start position:0% +demand functions + + + align:start position:0% +demand functions +the entire vector of prices denoted p 1 + + align:start position:0% +the entire vector of prices denoted p 1 + + + align:start position:0% +the entire vector of prices denoted p 1 +through p n + + align:start position:0% +through p n + + + align:start position:0% +through p n +and income + + align:start position:0% +and income + + + align:start position:0% +and income +denoted as i and you can think about + + align:start position:0% +denoted as i and you can think about + + + align:start position:0% +denoted as i and you can think about +prices and income denominated in dollars + + align:start position:0% +prices and income denominated in dollars + + + align:start position:0% +prices and income denominated in dollars +or some unit of account + + align:start position:0% +or some unit of account + + + align:start position:0% +or some unit of account +we're going to be spending + + align:start position:0% +we're going to be spending + + + align:start position:0% +we're going to be spending +time looking at how the price of good k + + align:start position:0% +time looking at how the price of good k + + + align:start position:0% +time looking at how the price of good k +changes when we change the price of good + + align:start position:0% +changes when we change the price of good + + + align:start position:0% +changes when we change the price of good +k + + align:start position:0% +k + + + align:start position:0% +k +but you know of necessity other goods + + align:start position:0% +but you know of necessity other goods + + + align:start position:0% +but you know of necessity other goods +will be changing as well + + align:start position:0% +will be changing as well + + + align:start position:0% +will be changing as well +it's at best the implicit happenings in + + align:start position:0% +it's at best the implicit happenings in + + + align:start position:0% +it's at best the implicit happenings in +the diagrams + + align:start position:0% +the diagrams + + + align:start position:0% +the diagrams +okay so here is a little bit of a repeat + + align:start position:0% +okay so here is a little bit of a repeat + + + align:start position:0% +okay so here is a little bit of a repeat +but expanded from last time we've got + + align:start position:0% +but expanded from last time we've got + + + align:start position:0% +but expanded from last time we've got +two goods denoted x and y + + align:start position:0% +two goods denoted x and y + + + align:start position:0% +two goods denoted x and y +and this household has a certain amount + + align:start position:0% +and this household has a certain amount + + + align:start position:0% +and this household has a certain amount +of income i + + align:start position:0% +of income i + + + align:start position:0% +of income i +uh say i2 if income were i2 this would + + align:start position:0% +uh say i2 if income were i2 this would + + + align:start position:0% +uh say i2 if income were i2 this would +be the budget line which has a slope of + + align:start position:0% +be the budget line which has a slope of + + + align:start position:0% +be the budget line which has a slope of +px over py + + align:start position:0% +px over py + + + align:start position:0% +px over py +minus + + align:start position:0% +minus + + + align:start position:0% +minus +and this is the tangency which is the + + align:start position:0% +and this is the tangency which is the + + + align:start position:0% +and this is the tangency which is the +maximum utility point denoted x2 y2 + + align:start position:0% +maximum utility point denoted x2 y2 + + + align:start position:0% +maximum utility point denoted x2 y2 +associated with income i2 + + align:start position:0% +associated with income i2 + + + align:start position:0% +associated with income i2 +what this diagram is featuring though is + + align:start position:0% +what this diagram is featuring though is + + + align:start position:0% +what this diagram is featuring though is +not a single maximization + + align:start position:0% +not a single maximization + + + align:start position:0% +not a single maximization +it's how the maximization point changes + + align:start position:0% +it's how the maximization point changes + + + align:start position:0% +it's how the maximization point changes +if you increase income so you would move + + align:start position:0% +if you increase income so you would move + + + align:start position:0% +if you increase income so you would move +from x to y 2 to x 3 y 3 for example + + align:start position:0% +from x to y 2 to x 3 y 3 for example + + + align:start position:0% +from x to y 2 to x 3 y 3 for example +and likewise if your income were less + + align:start position:0% +and likewise if your income were less + + + align:start position:0% +and likewise if your income were less +if this household's income were less + + align:start position:0% +if this household's income were less + + + align:start position:0% +if this household's income were less +they would move to + + align:start position:0% +they would move to + + + align:start position:0% +they would move to +y1 x1 so this + + align:start position:0% +y1 x1 so this + + + align:start position:0% +y1 x1 so this +you could connect these dots + + align:start position:0% +you could connect these dots + + + align:start position:0% +you could connect these dots +and as only income is varying and prices + + align:start position:0% +and as only income is varying and prices + + + align:start position:0% +and as only income is varying and prices +and the price ratios held fixed + + align:start position:0% +and the price ratios held fixed + + + align:start position:0% +and the price ratios held fixed +we could call the connected dots an + + align:start position:0% +we could call the connected dots an + + + align:start position:0% +we could call the connected dots an +income expansion path and i'll show you + + align:start position:0% +income expansion path and i'll show you + + + align:start position:0% +income expansion path and i'll show you +some examples of that momentarily + + align:start position:0% +some examples of that momentarily + + + align:start position:0% +some examples of that momentarily +here is + + align:start position:0% +here is + + + align:start position:0% +here is +a different experiment can we miss + + align:start position:0% +a different experiment can we miss + + + align:start position:0% +a different experiment can we miss +something well in this one + + align:start position:0% +something well in this one + + + align:start position:0% +something well in this one +you'll get lulled into thinking that as + + align:start position:0% +you'll get lulled into thinking that as + + + align:start position:0% +you'll get lulled into thinking that as +income changes the amount spent on both + + align:start position:0% +income changes the amount spent on both + + + align:start position:0% +income changes the amount spent on both +goods has to change increase but that's + + align:start position:0% +goods has to change increase but that's + + + align:start position:0% +goods has to change increase but that's +not necessarily the case + + align:start position:0% +not necessarily the case + + + align:start position:0% +not necessarily the case +so here again + + align:start position:0% +so here again + + + align:start position:0% +so here again +we're going from i1 to i2 to i3 + + align:start position:0% +we're going from i1 to i2 to i3 + + + align:start position:0% +we're going from i1 to i2 to i3 +and tracing out the quantities from + + align:start position:0% +and tracing out the quantities from + + + align:start position:0% +and tracing out the quantities from +zy1 zy2 to zy3 + + align:start position:0% +zy1 zy2 to zy3 + + + align:start position:0% +zy1 zy2 to zy3 +and here the + + align:start position:0% +and here the + + + align:start position:0% +and here the +quantity demanded of good + + align:start position:0% +quantity demanded of good + + + align:start position:0% +quantity demanded of good +y is increasing + + align:start position:0% +y is increasing + + + align:start position:0% +y is increasing +but the quantity demanded of good z is + + align:start position:0% +but the quantity demanded of good z is + + + align:start position:0% +but the quantity demanded of good z is +actually decreasing + + align:start position:0% +actually decreasing + + + align:start position:0% +actually decreasing +so there's nothing terribly peculiar + + align:start position:0% +so there's nothing terribly peculiar + + + align:start position:0% +so there's nothing terribly peculiar +about the shape of these indifference + + align:start position:0% +about the shape of these indifference + + + align:start position:0% +about the shape of these indifference +curves we didn't have to struggle too + + align:start position:0% +curves we didn't have to struggle too + + + align:start position:0% +curves we didn't have to struggle too +hard to get this phenomenon to happen + + align:start position:0% +hard to get this phenomenon to happen + + + align:start position:0% +hard to get this phenomenon to happen +but but anyway this phenomenon has a + + align:start position:0% +but but anyway this phenomenon has a + + + align:start position:0% +but but anyway this phenomenon has a +name namely + + align:start position:0% +name namely + + + align:start position:0% +name namely +the good + + align:start position:0% +the good + + + align:start position:0% +the good +y over here would be called a normal + + align:start position:0% +y over here would be called a normal + + + align:start position:0% +y over here would be called a normal +good + + align:start position:0% +good + + + align:start position:0% +good +and good z + + align:start position:0% +and good z + + + align:start position:0% +and good z +would be called an inferior good + + align:start position:0% +would be called an inferior good + + + align:start position:0% +would be called an inferior good +or a necessity + + align:start position:0% +or a necessity + + + align:start position:0% +or a necessity +because the amount that you consume of + + align:start position:0% +because the amount that you consume of + + + align:start position:0% +because the amount that you consume of +it diminishes as income goes up + + align:start position:0% +it diminishes as income goes up + + + align:start position:0% +it diminishes as income goes up +so here are those definitions + + align:start position:0% +so here are those definitions + + + align:start position:0% +so here are those definitions +a good for which the demand demand of + + align:start position:0% +a good for which the demand demand of + + + align:start position:0% +a good for which the demand demand of +good i goes down as income capital i + + align:start position:0% +good i goes down as income capital i + + + align:start position:0% +good i goes down as income capital i +goes up + + align:start position:0% +goes up + + + align:start position:0% +goes up +is said to be an inferior good it + + align:start position:0% +is said to be an inferior good it + + + align:start position:0% +is said to be an inferior good it +doesn't have to happen over the entire + + align:start position:0% +doesn't have to happen over the entire + + + align:start position:0% +doesn't have to happen over the entire +range of income and prices but it if it + + align:start position:0% +range of income and prices but it if it + + + align:start position:0% +range of income and prices but it if it +happens locally it's called an inferior + + align:start position:0% +happens locally it's called an inferior + + + align:start position:0% +happens locally it's called an inferior +good locally and likewise if the + + align:start position:0% +good locally and likewise if the + + + align:start position:0% +good locally and likewise if the +derivative with respect to income is + + align:start position:0% +derivative with respect to income is + + + align:start position:0% +derivative with respect to income is +positive then we call + + align:start position:0% +positive then we call + + + align:start position:0% +positive then we call +in some range the good to be a normal + + align:start position:0% +in some range the good to be a normal + + + align:start position:0% +in some range the good to be a normal +good or non-inferior good + + align:start position:0% +good or non-inferior good + + + align:start position:0% +good or non-inferior good +so there's something called engel's law + + align:start position:0% +so there's something called engel's law + + + align:start position:0% +so there's something called engel's law +and with the caveat that this is not one + + align:start position:0% +and with the caveat that this is not one + + + align:start position:0% +and with the caveat that this is not one +household + + align:start position:0% +household + + + align:start position:0% +household +it's actually comparing across + + align:start position:0% +it's actually comparing across + + + align:start position:0% +it's actually comparing across +households + + align:start position:0% +households + + + align:start position:0% +households +that differ in their annual income so + + align:start position:0% +that differ in their annual income so + + + align:start position:0% +that differ in their annual income so +here we're going + + align:start position:0% +here we're going + + + align:start position:0% +here we're going +from an annual income of 225 + + align:start position:0% +from an annual income of 225 + + + align:start position:0% +from an annual income of 225 +to this is written in 1920 by the way + + align:start position:0% +to this is written in 1920 by the way + + + align:start position:0% +to this is written in 1920 by the way +don't be too alarmed it's been a lot of + + align:start position:0% +don't be too alarmed it's been a lot of + + + align:start position:0% +don't be too alarmed it's been a lot of +inflation + + align:start position:0% +inflation + + + align:start position:0% +inflation +so this in real purchasing power was + + align:start position:0% +so this in real purchasing power was + + + align:start position:0% +so this in real purchasing power was +more than you thought 300 + + align:start position:0% +more than you thought 300 + + + align:start position:0% +more than you thought 300 +or this range 450 to 600 or + + align:start position:0% +or this range 450 to 600 or + + + align:start position:0% +or this range 450 to 600 or +750 to 1000 + + align:start position:0% +750 to 1000 + + + align:start position:0% +750 to 1000 +okay and what you can see is the percent + + align:start position:0% +okay and what you can see is the percent + + + align:start position:0% +okay and what you can see is the percent +spent + + align:start position:0% +spent + + + align:start position:0% +spent +of the budget + + align:start position:0% +of the budget + + + align:start position:0% +of the budget +on food declines + + align:start position:0% +on food declines + + + align:start position:0% +on food declines +as we move to these + + align:start position:0% +as we move to these + + + align:start position:0% +as we move to these +income groups with higher and higher + + align:start position:0% +income groups with higher and higher + + + align:start position:0% +income groups with higher and higher +income + + align:start position:0% +income + + + align:start position:0% +income +so in some sense if all consumers were + + align:start position:0% +so in some sense if all consumers were + + + align:start position:0% +so in some sense if all consumers were +like and some had more income than + + align:start position:0% +like and some had more income than + + + align:start position:0% +like and some had more income than +others we'd be looking at what an + + align:start position:0% +others we'd be looking at what an + + + align:start position:0% +others we'd be looking at what an +individual household would do as its + + align:start position:0% +individual household would do as its + + + align:start position:0% +individual household would do as its +income changed + + align:start position:0% +income changed + + + align:start position:0% +income changed +and in this case food would be an + + align:start position:0% +and in this case food would be an + + + align:start position:0% +and in this case food would be an +inferior good you're saying what's going + + align:start position:0% +inferior good you're saying what's going + + + align:start position:0% +inferior good you're saying what's going +up clothing not by much + + align:start position:0% +up clothing not by much + + + align:start position:0% +up clothing not by much +lodging not at all + + align:start position:0% +lodging not at all + + + align:start position:0% +lodging not at all +what really expands as income goes up is + + align:start position:0% +what really expands as income goes up is + + + align:start position:0% +what really expands as income goes up is +services education health legal and + + align:start position:0% +services education health legal and + + + align:start position:0% +services education health legal and +other services in fact in the u.s + + align:start position:0% +other services in fact in the u.s + + + align:start position:0% +other services in fact in the u.s +economy looking over you know decades + + align:start position:0% +economy looking over you know decades + + + align:start position:0% +economy looking over you know decades +the fraction of services produced in gdp + + align:start position:0% +the fraction of services produced in gdp + + + align:start position:0% +the fraction of services produced in gdp +is just keeps going up and up which is + + align:start position:0% +is just keeps going up and up which is + + + align:start position:0% +is just keeps going up and up which is +reflective of the fact that as + + align:start position:0% +reflective of the fact that as + + + align:start position:0% +reflective of the fact that as +households have more income they demand + + align:start position:0% +households have more income they demand + + + align:start position:0% +households have more income they demand +more services and less food + + align:start position:0% + + + + align:start position:0% + +so that's pretty dated 1920 so i went on + + align:start position:0% +so that's pretty dated 1920 so i went on + + + align:start position:0% +so that's pretty dated 1920 so i went on +the web and looked this thing up + + align:start position:0% +the web and looked this thing up + + + align:start position:0% +the web and looked this thing up +engel's law today + + align:start position:0% +engel's law today + + + align:start position:0% +engel's law today +here we're dividing households into + + align:start position:0% +here we're dividing households into + + + align:start position:0% +here we're dividing households into +quintiles five groups + + align:start position:0% +quintiles five groups + + + align:start position:0% +quintiles five groups +an equal number of household in each + + align:start position:0% +an equal number of household in each + + + align:start position:0% +an equal number of household in each +group + + align:start position:0% +group + + + align:start position:0% +group +and we plot the fraction of so-called + + align:start position:0% +and we plot the fraction of so-called + + + align:start position:0% +and we plot the fraction of so-called +luxuries and necessities for each group + + align:start position:0% +luxuries and necessities for each group + + + align:start position:0% +luxuries and necessities for each group +now this is a bit problematic in the + + align:start position:0% +now this is a bit problematic in the + + + align:start position:0% +now this is a bit problematic in the +sense that necessities are defined as + + align:start position:0% +sense that necessities are defined as + + + align:start position:0% +sense that necessities are defined as +goods or services where consumption is + + align:start position:0% +goods or services where consumption is + + + align:start position:0% +goods or services where consumption is +proportionately lower as a person's + + align:start position:0% +proportionately lower as a person's + + + align:start position:0% +proportionately lower as a person's +income increases so again necessity or + + align:start position:0% +income increases so again necessity or + + + align:start position:0% +income increases so again necessity or +non-normal goods are as we defined it in + + align:start position:0% +non-normal goods are as we defined it in + + + align:start position:0% +non-normal goods are as we defined it in +the last three slides not too + + align:start position:0% +the last three slides not too + + + align:start position:0% +the last three slides not too +surprisingly the highest income groups + + align:start position:0% +surprisingly the highest income groups + + + align:start position:0% +surprisingly the highest income groups +the top 20 percent of the population the + + align:start position:0% +the top 20 percent of the population the + + + align:start position:0% +the top 20 percent of the population the +proportion of expenditure on luxuries is + + align:start position:0% +proportion of expenditure on luxuries is + + + align:start position:0% +proportion of expenditure on luxuries is +a lot higher than on necessities and + + align:start position:0% +a lot higher than on necessities and + + + align:start position:0% +a lot higher than on necessities and +that gap lowers until you get to the + + align:start position:0% +that gap lowers until you get to the + + + align:start position:0% +that gap lowers until you get to the +lowest group + + align:start position:0% +lowest group + + + align:start position:0% +lowest group +in which case the the fraction spent on + + align:start position:0% +in which case the the fraction spent on + + + align:start position:0% +in which case the the fraction spent on +necessities is a lot higher than + + align:start position:0% +necessities is a lot higher than + + + align:start position:0% +necessities is a lot higher than +luxuries + + align:start position:0% +luxuries + + + align:start position:0% +luxuries +now when i grabbed this there was a + + align:start position:0% +now when i grabbed this there was a + + + align:start position:0% +now when i grabbed this there was a +whole article about how poor people are + + align:start position:0% +whole article about how poor people are + + + align:start position:0% +whole article about how poor people are +extravagant because they're still + + align:start position:0% +extravagant because they're still + + + align:start position:0% +extravagant because they're still +spending money on luxury goods well i + + align:start position:0% +spending money on luxury goods well i + + + align:start position:0% +spending money on luxury goods well i +mean narrowly speaking yes that's true + + align:start position:0% +mean narrowly speaking yes that's true + + + align:start position:0% +mean narrowly speaking yes that's true +but again it's a little bit harsh + + align:start position:0% +but again it's a little bit harsh + + + align:start position:0% +but again it's a little bit harsh +because it doesn't mean they're driving + + align:start position:0% +because it doesn't mean they're driving + + + align:start position:0% +because it doesn't mean they're driving +around in a mercedes-benz it just means + + align:start position:0% +around in a mercedes-benz it just means + + + align:start position:0% +around in a mercedes-benz it just means +they're eating some fraction of what + + align:start position:0% +they're eating some fraction of what + + + align:start position:0% +they're eating some fraction of what +they spend on are normal goods + + align:start position:0% +they spend on are normal goods + + + align:start position:0% +they spend on are normal goods +is it wait um + + align:start position:0% +is it wait um + + + align:start position:0% +is it wait um +can you + + align:start position:0% +can you + + + align:start position:0% +can you +is there a wait is there a little bit of + + align:start position:0% +is there a wait is there a little bit of + + + align:start position:0% +is there a wait is there a little bit of +issue with how + + align:start position:0% +issue with how + + + align:start position:0% +issue with how +those two um + + align:start position:0% +those two um + + + align:start position:0% +those two um +i guess how the two lines are defined + + align:start position:0% +i guess how the two lines are defined + + + align:start position:0% +i guess how the two lines are defined +because the way you defined them it + + align:start position:0% +because the way you defined them it + + + align:start position:0% +because the way you defined them it +seems like you said luxuries are just + + align:start position:0% +seems like you said luxuries are just + + + align:start position:0% +seems like you said luxuries are just +what rich people buy and this is + + align:start position:0% +what rich people buy and this is + + + align:start position:0% +what rich people buy and this is +necessities are what poor people buy so + + align:start position:0% +necessities are what poor people buy so + + + align:start position:0% +necessities are what poor people buy so +doesn't this kind of get confirmed just + + align:start position:0% +doesn't this kind of get confirmed just + + + align:start position:0% +doesn't this kind of get confirmed just +by how you define it yes i think that's + + align:start position:0% +by how you define it yes i think that's + + + align:start position:0% +by how you define it yes i think that's +exactly right it's almost + + align:start position:0% +exactly right it's almost + + + align:start position:0% +exactly right it's almost +tautological i mean the way they defined + + align:start position:0% +tautological i mean the way they defined + + + align:start position:0% +tautological i mean the way they defined +it it has to be true that this blue line + + align:start position:0% +it it has to be true that this blue line + + + align:start position:0% +it it has to be true that this blue line +is going up and up uh as you go across + + align:start position:0% +is going up and up uh as you go across + + + align:start position:0% +is going up and up uh as you go across +the quintiles + + align:start position:0% +the quintiles + + + align:start position:0% +the quintiles +so i agree with that comment but i still + + align:start position:0% +so i agree with that comment but i still + + + align:start position:0% +so i agree with that comment but i still +think + + align:start position:0% +think + + + align:start position:0% +think +the graphs kind of how much is it going + + align:start position:0% +the graphs kind of how much is it going + + + align:start position:0% +the graphs kind of how much is it going +up what's the difference and so on could + + align:start position:0% +up what's the difference and so on could + + + align:start position:0% +up what's the difference and so on could +go up just a teeny little bit in which + + align:start position:0% +go up just a teeny little bit in which + + + align:start position:0% +go up just a teeny little bit in which +case that blue line would not move much + + align:start position:0% +case that blue line would not move much + + + align:start position:0% +case that blue line would not move much +other questions + + align:start position:0% + + + + align:start position:0% + +well one takeaway from this is + + align:start position:0% +well one takeaway from this is + + + align:start position:0% +well one takeaway from this is +you know different households + + align:start position:0% +you know different households + + + align:start position:0% +you know different households +that differ in income do not spend the + + align:start position:0% +that differ in income do not spend the + + + align:start position:0% +that differ in income do not spend the +same fraction of their money on + + align:start position:0% +same fraction of their money on + + + align:start position:0% +same fraction of their money on +on goods so let me take a chance at the + + align:start position:0% +on goods so let me take a chance at the + + + align:start position:0% +on goods so let me take a chance at the +risk of so you know preview of coming + + align:start position:0% +risk of so you know preview of coming + + + align:start position:0% +risk of so you know preview of coming +attractions + + align:start position:0% +attractions + + + align:start position:0% +attractions +this is way back in lecture 18 + + align:start position:0% +this is way back in lecture 18 + + + align:start position:0% +this is way back in lecture 18 +where we're going to talk about + + align:start position:0% +where we're going to talk about + + + align:start position:0% +where we're going to talk about +aggregation + + align:start position:0% +aggregation + + + align:start position:0% +aggregation +which has to do with whether we can + + align:start position:0% +which has to do with whether we can + + + align:start position:0% +which has to do with whether we can +represent demand functions as if they + + align:start position:0% +represent demand functions as if they + + + align:start position:0% +represent demand functions as if they +came from a single maximizing + + align:start position:0% +came from a single maximizing + + + align:start position:0% +came from a single maximizing +representative household or weaker that + + align:start position:0% +representative household or weaker that + + + align:start position:0% +representative household or weaker that +there is a group of households like the + + align:start position:0% +there is a group of households like the + + + align:start position:0% +there is a group of households like the +lower quintile + + align:start position:0% +lower quintile + + + align:start position:0% +lower quintile +and they're all alike and we could take + + align:start position:0% +and they're all alike and we could take + + + align:start position:0% +and they're all alike and we could take +a representative quintile low quintile + + align:start position:0% +a representative quintile low quintile + + + align:start position:0% +a representative quintile low quintile +household and talk about the demand as + + align:start position:0% +household and talk about the demand as + + + align:start position:0% +household and talk about the demand as +if it were coming from that one person + + align:start position:0% +if it were coming from that one person + + + align:start position:0% +if it were coming from that one person +what is a necessary and sufficient + + align:start position:0% +what is a necessary and sufficient + + + align:start position:0% +what is a necessary and sufficient +assumption for us to be able to do that + + align:start position:0% +assumption for us to be able to do that + + + align:start position:0% +assumption for us to be able to do that +kind of aggregation + + align:start position:0% +kind of aggregation + + + align:start position:0% +kind of aggregation +it is that these income in this case + + align:start position:0% +it is that these income in this case + + + align:start position:0% +it is that these income in this case +denoted wealth expansion paths are + + align:start position:0% +denoted wealth expansion paths are + + + align:start position:0% +denoted wealth expansion paths are +linear and have exactly the same slope + + align:start position:0% +linear and have exactly the same slope + + + align:start position:0% +linear and have exactly the same slope +so + + align:start position:0% +so + + + align:start position:0% +so +these guys will spend and i'm not trying + + align:start position:0% +these guys will spend and i'm not trying + + + align:start position:0% +these guys will spend and i'm not trying +to go through the entire lecture i'm + + align:start position:0% +to go through the entire lecture i'm + + + align:start position:0% +to go through the entire lecture i'm +just really trying to motivate you that + + align:start position:0% +just really trying to motivate you that + + + align:start position:0% +just really trying to motivate you that +we looked at some micro data and later + + align:start position:0% +we looked at some micro data and later + + + align:start position:0% +we looked at some micro data and later +we'll make some assumptions it's good to + + align:start position:0% +we'll make some assumptions it's good to + + + align:start position:0% +we'll make some assumptions it's good to +put the micro data about the assumptions + + align:start position:0% +put the micro data about the assumptions + + + align:start position:0% +put the micro data about the assumptions +on the table at the same time + + align:start position:0% +on the table at the same time + + + align:start position:0% +on the table at the same time +and compare them + + align:start position:0% +and compare them + + + align:start position:0% +and compare them +what's going on here is that if these + + align:start position:0% +what's going on here is that if these + + + align:start position:0% +what's going on here is that if these +income expansion paths are parallel + + align:start position:0% +income expansion paths are parallel + + + align:start position:0% +income expansion paths are parallel +then when we increase income for one + + align:start position:0% +then when we increase income for one + + + align:start position:0% +then when we increase income for one +household its expenditure would go up + + align:start position:0% +household its expenditure would go up + + + align:start position:0% +household its expenditure would go up +but because this line is parallel when + + align:start position:0% +but because this line is parallel when + + + align:start position:0% +but because this line is parallel when +we decrease expenditure for another one + + align:start position:0% +we decrease expenditure for another one + + + align:start position:0% +we decrease expenditure for another one +its expenditures will go down in exactly + + align:start position:0% +its expenditures will go down in exactly + + + align:start position:0% +its expenditures will go down in exactly +the same amount that this disguise went + + align:start position:0% +the same amount that this disguise went + + + align:start position:0% +the same amount that this disguise went +up so those income effects are + + align:start position:0% +up so those income effects are + + + align:start position:0% +up so those income effects are +completely offsetting and that turns out + + align:start position:0% +completely offsetting and that turns out + + + align:start position:0% +completely offsetting and that turns out +to be necessary and sufficient to add up + + align:start position:0% +to be necessary and sufficient to add up + + + align:start position:0% +to be necessary and sufficient to add up +all of income and drive demand as if + + align:start position:0% +all of income and drive demand as if + + + align:start position:0% +all of income and drive demand as if +we'd given all of income to one + + align:start position:0% +we'd given all of income to one + + + align:start position:0% +we'd given all of income to one +household + + align:start position:0% +household + + + align:start position:0% +household +all right well it was with some + + align:start position:0% +all right well it was with some + + + align:start position:0% +all right well it was with some +trepidation that i showed you this + + align:start position:0% +trepidation that i showed you this + + + align:start position:0% +trepidation that i showed you this +picture + + align:start position:0% +picture + + + align:start position:0% +picture +that i thought you might like to know + + align:start position:0% +that i thought you might like to know + + + align:start position:0% +that i thought you might like to know +what's coming + + align:start position:0% +what's coming + + + align:start position:0% +what's coming +and we'll review all of that when we get + + align:start position:0% +and we'll review all of that when we get + + + align:start position:0% +and we'll review all of that when we get +to 18. okay so let's talk about income + + align:start position:0% +to 18. okay so let's talk about income + + + align:start position:0% +to 18. okay so let's talk about income +and substitution effects now instead of + + align:start position:0% +and substitution effects now instead of + + + align:start position:0% +and substitution effects now instead of +changing income + + align:start position:0% +changing income + + + align:start position:0% +changing income +we want to change a price + + align:start position:0% +we want to change a price + + + align:start position:0% +we want to change a price +we're going to focus on good x + + align:start position:0% +we're going to focus on good x + + + align:start position:0% +we're going to focus on good x +we're going to look at an initial point + + align:start position:0% +we're going to look at an initial point + + + align:start position:0% +we're going to look at an initial point +which is + + align:start position:0% +which is + + + align:start position:0% +which is +y star x star + + align:start position:0% +y star x star + + + align:start position:0% +y star x star +and then we're going to lower the price + + align:start position:0% +and then we're going to lower the price + + + align:start position:0% +and then we're going to lower the price +of good x + + align:start position:0% +of good x + + + align:start position:0% +of good x +and not touch good y + + align:start position:0% +and not touch good y + + + align:start position:0% +and not touch good y +one way to kind of + + align:start position:0% +one way to kind of + + + align:start position:0% +one way to kind of +quickly convince yourself that the + + align:start position:0% +quickly convince yourself that the + + + align:start position:0% +quickly convince yourself that the +diagram is correct is that this point + + align:start position:0% +diagram is correct is that this point + + + align:start position:0% +diagram is correct is that this point +over here on the y-axis is taking all + + align:start position:0% +over here on the y-axis is taking all + + + align:start position:0% +over here on the y-axis is taking all +your income and devoting it to the + + align:start position:0% +your income and devoting it to the + + + align:start position:0% +your income and devoting it to the +purchase of good y the price of y hasn't + + align:start position:0% +purchase of good y the price of y hasn't + + + align:start position:0% +purchase of good y the price of y hasn't +changed so this point hasn't changed but + + align:start position:0% +changed so this point hasn't changed but + + + align:start position:0% +changed so this point hasn't changed but +the price of x is going down + + align:start position:0% +the price of x is going down + + + align:start position:0% +the price of x is going down +and logically + + align:start position:0% +and logically + + + align:start position:0% +and logically +the set of things you can buy is + + align:start position:0% +the set of things you can buy is + + + align:start position:0% +the set of things you can buy is +expanding + + align:start position:0% +expanding + + + align:start position:0% +expanding +so this budget line shifts to the right + + align:start position:0% +so this budget line shifts to the right + + + align:start position:0% +so this budget line shifts to the right +but not in a parallel fashion so what is + + align:start position:0% +but not in a parallel fashion so what is + + + align:start position:0% +but not in a parallel fashion so what is +the new purchase + + align:start position:0% +the new purchase + + + align:start position:0% +the new purchase +the new purchase is the tangency y + + align:start position:0% +the new purchase is the tangency y + + + align:start position:0% +the new purchase is the tangency y +double star and x double star and we're + + align:start position:0% +double star and x double star and we're + + + align:start position:0% +double star and x double star and we're +going to break that movement from the + + align:start position:0% +going to break that movement from the + + + align:start position:0% +going to break that movement from the +initial point to the subsequent point + + align:start position:0% +initial point to the subsequent point + + + align:start position:0% +initial point to the subsequent point +into two pieces + + align:start position:0% +into two pieces + + + align:start position:0% +into two pieces +one a price effect and two an income + + align:start position:0% +one a price effect and two an income + + + align:start position:0% +one a price effect and two an income +effect + + align:start position:0% +effect + + + align:start position:0% +effect +so since the price of good x goes down + + align:start position:0% +so since the price of good x goes down + + + align:start position:0% +so since the price of good x goes down +px over py + + align:start position:0% +px over py + + + align:start position:0% +px over py +in absolute value is going down so + + align:start position:0% +in absolute value is going down so + + + align:start position:0% +in absolute value is going down so +there's a new + + align:start position:0% +there's a new + + + align:start position:0% +there's a new +budget line with a lower slope + + align:start position:0% +budget line with a lower slope + + + align:start position:0% +budget line with a lower slope +that is pivoting on the initial + + align:start position:0% +that is pivoting on the initial + + + align:start position:0% +that is pivoting on the initial +indifference curve u1 + + align:start position:0% +indifference curve u1 + + + align:start position:0% +indifference curve u1 +so setting aside income effects which + + align:start position:0% +so setting aside income effects which + + + align:start position:0% +so setting aside income effects which +we'll get to momentarily + + align:start position:0% +we'll get to momentarily + + + align:start position:0% +we'll get to momentarily +the natural + + align:start position:0% +the natural + + + align:start position:0% +the natural +impact of lowering the price of good x + + align:start position:0% +impact of lowering the price of good x + + + align:start position:0% +impact of lowering the price of good x +is to increase the expenditure of good x + + align:start position:0% +is to increase the expenditure of good x + + + align:start position:0% +is to increase the expenditure of good x +and decrease the expenditure of good y + + align:start position:0% +and decrease the expenditure of good y + + + align:start position:0% +and decrease the expenditure of good y +so that's called the substitution effect + + align:start position:0% +so that's called the substitution effect + + + align:start position:0% +so that's called the substitution effect +and it's a movement from x star y star + + align:start position:0% +and it's a movement from x star y star + + + align:start position:0% +and it's a movement from x star y star +to be + + align:start position:0% +to be + + + align:start position:0% +to be +but in fact of course income effectively + + align:start position:0% +but in fact of course income effectively + + + align:start position:0% +but in fact of course income effectively +purchasing power has gone up even though + + align:start position:0% +purchasing power has gone up even though + + + align:start position:0% +purchasing power has gone up even though +nominal income has not moved one good at + + align:start position:0% +nominal income has not moved one good at + + + align:start position:0% +nominal income has not moved one good at +least is cheaper so their effective + + align:start position:0% +least is cheaper so their effective + + + align:start position:0% +least is cheaper so their effective +income has gone up and that's + + align:start position:0% +income has gone up and that's + + + align:start position:0% +income has gone up and that's +represented by this parallel shift from + + align:start position:0% +represented by this parallel shift from + + + align:start position:0% +represented by this parallel shift from +b to + + align:start position:0% +b to + + + align:start position:0% +b to +x double star y double star and that + + align:start position:0% +x double star y double star and that + + + align:start position:0% +x double star y double star and that +last bit from b to there is called the + + align:start position:0% +last bit from b to there is called the + + + align:start position:0% +last bit from b to there is called the +income effect + + align:start position:0% +income effect + + + align:start position:0% +income effect +so the global movement is from x star + + align:start position:0% +so the global movement is from x star + + + align:start position:0% +so the global movement is from x star +to x double star + + align:start position:0% +to x double star + + + align:start position:0% +to x double star +with a corresponding movement from y + + align:start position:0% +with a corresponding movement from y + + + align:start position:0% +with a corresponding movement from y +star to y double star and it's broken + + align:start position:0% +star to y double star and it's broken + + + align:start position:0% +star to y double star and it's broken +into two pieces + + align:start position:0% +into two pieces + + + align:start position:0% +into two pieces +this substitution effect which + + align:start position:0% +this substitution effect which + + + align:start position:0% +this substitution effect which +corresponds with movement along the + + align:start position:0% +corresponds with movement along the + + + align:start position:0% +corresponds with movement along the +original indifference curve and the + + align:start position:0% +original indifference curve and the + + + align:start position:0% +original indifference curve and the +income effect of having higher effective + + align:start position:0% +income effect of having higher effective + + + align:start position:0% +income effect of having higher effective +purchasing power + + align:start position:0% +purchasing power + + + align:start position:0% +purchasing power +okay + + align:start position:0% +okay + + + align:start position:0% +okay +a lot of today's lecture is just like + + align:start position:0% +a lot of today's lecture is just like + + + align:start position:0% +a lot of today's lecture is just like +going over this in various ways + + align:start position:0% +going over this in various ways + + + align:start position:0% +going over this in various ways +you can get mesmerized with the price + + align:start position:0% +you can get mesmerized with the price + + + align:start position:0% +you can get mesmerized with the price +decrease + + align:start position:0% +decrease + + + align:start position:0% +decrease +here is a price increase + + align:start position:0% +here is a price increase + + + align:start position:0% +here is a price increase +uh they're starting out + + align:start position:0% +uh they're starting out + + + align:start position:0% +uh they're starting out +with a tangency + + align:start position:0% +with a tangency + + + align:start position:0% +with a tangency +the uh price of good x still goes in + + align:start position:0% +the uh price of good x still goes in + + + align:start position:0% +the uh price of good x still goes in +this case up + + align:start position:0% +this case up + + + align:start position:0% +this case up +their purchasing power goes down the + + align:start position:0% +their purchasing power goes down the + + + align:start position:0% +their purchasing power goes down the +budget line rotates from this initial + + align:start position:0% +budget line rotates from this initial + + + align:start position:0% +budget line rotates from this initial +point inward + + align:start position:0% + + + + align:start position:0% + +so the total demand of the price + + align:start position:0% +so the total demand of the price + + + align:start position:0% +so the total demand of the price +increase is going + + align:start position:0% +increase is going + + + align:start position:0% +increase is going +down a reduction in x + + align:start position:0% +down a reduction in x + + + align:start position:0% +down a reduction in x +but again we can break that into two + + align:start position:0% +but again we can break that into two + + + align:start position:0% +but again we can break that into two +pieces + + align:start position:0% +pieces + + + align:start position:0% +pieces +one is the substitution effect the + + align:start position:0% +one is the substitution effect the + + + align:start position:0% +one is the substitution effect the +movement away from good x because it has + + align:start position:0% +movement away from good x because it has + + + align:start position:0% +movement away from good x because it has +a higher price relative to good y + + align:start position:0% +a higher price relative to good y + + + align:start position:0% +a higher price relative to good y +to point b + + align:start position:0% +to point b + + + align:start position:0% +to point b +and now we take into account the loss of + + align:start position:0% +and now we take into account the loss of + + + align:start position:0% +and now we take into account the loss of +effective purchasing power + + align:start position:0% +effective purchasing power + + + align:start position:0% +effective purchasing power +which is a shift in this budget line the + + align:start position:0% +which is a shift in this budget line the + + + align:start position:0% +which is a shift in this budget line the +dotted tangency line + + align:start position:0% +dotted tangency line + + + align:start position:0% +dotted tangency line +which is tangent at b to the actual new + + align:start position:0% +which is tangent at b to the actual new + + + align:start position:0% +which is tangent at b to the actual new +lower budget line + + align:start position:0% +lower budget line + + + align:start position:0% +lower budget line +so here we denote the + + align:start position:0% +so here we denote the + + + align:start position:0% +so here we denote the +the combination of the substitution and + + align:start position:0% +the combination of the substitution and + + + align:start position:0% +the combination of the substitution and +income effects + + align:start position:0% +income effects + + + align:start position:0% +income effects +this is really the previous diagram in + + align:start position:0% +this is really the previous diagram in + + + align:start position:0% +this is really the previous diagram in +reverse + + align:start position:0% +reverse + + + align:start position:0% +reverse +but i think it's useful + + align:start position:0% +but i think it's useful + + + align:start position:0% +but i think it's useful +to show both + + align:start position:0% +to show both + + + align:start position:0% +to show both +of course we can also start changing the + + align:start position:0% +of course we can also start changing the + + + align:start position:0% +of course we can also start changing the +price of y let's not do that right away + + align:start position:0% +price of y let's not do that right away + + + align:start position:0% +price of y let's not do that right away +i'll come back to that later but the + + align:start position:0% +i'll come back to that later but the + + + align:start position:0% +i'll come back to that later but the +principles remain the same + + align:start position:0% +principles remain the same + + + align:start position:0% +principles remain the same +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +let's construct some demand curves + + align:start position:0% +let's construct some demand curves + + + align:start position:0% +let's construct some demand curves +as in the equation system we had + + align:start position:0% +as in the equation system we had + + + align:start position:0% +as in the equation system we had +initially + + align:start position:0% +initially + + + align:start position:0% +initially +if we keep lowering the price moving in + + align:start position:0% +if we keep lowering the price moving in + + + align:start position:0% +if we keep lowering the price moving in +this direction + + align:start position:0% +this direction + + + align:start position:0% +this direction +we trace out this tangency + + align:start position:0% +we trace out this tangency + + + align:start position:0% +we trace out this tangency +and those will be the demand at the + + align:start position:0% +and those will be the demand at the + + + align:start position:0% +and those will be the demand at the +associated prices so here + + align:start position:0% +associated prices so here + + + align:start position:0% +associated prices so here +we have say x + + align:start position:0% +we have say x + + + align:start position:0% +we have say x +prime at price p prime + + align:start position:0% +prime at price p prime + + + align:start position:0% +prime at price p prime +x double prime at price p double prime + + align:start position:0% +x double prime at price p double prime + + + align:start position:0% +x double prime at price p double prime +and + + align:start position:0% +and + + + align:start position:0% +and +this would would have been even better + + align:start position:0% +this would would have been even better + + + align:start position:0% +this would would have been even better +if + + align:start position:0% +if + + + align:start position:0% +if +these things were lined up but they were + + align:start position:0% +these things were lined up but they were + + + align:start position:0% +these things were lined up but they were +intended to be + + align:start position:0% +intended to be + + + align:start position:0% +intended to be +x triple prime + + align:start position:0% + + + + align:start position:0% + +at price p triple prime + + align:start position:0% +at price p triple prime + + + align:start position:0% +at price p triple prime +now again + + align:start position:0% +now again + + + align:start position:0% +now again +price is going down + + align:start position:0% +price is going down + + + align:start position:0% +price is going down +and + + align:start position:0% +and + + + align:start position:0% +and +demand is going up + + align:start position:0% + + + + align:start position:0% + +now just to alert you + + align:start position:0% +now just to alert you + + + align:start position:0% +now just to alert you +i don't know where this got started with + + align:start position:0% +i don't know where this got started with + + + align:start position:0% +i don't know where this got started with +marshall or whatever + + align:start position:0% +marshall or whatever + + + align:start position:0% +marshall or whatever +but usually we plot you know y as a + + align:start position:0% +but usually we plot you know y as a + + + align:start position:0% +but usually we plot you know y as a +function of x + + align:start position:0% +function of x + + + align:start position:0% +function of x +where x is on the y axis and y the + + align:start position:0% +where x is on the y axis and y the + + + align:start position:0% +where x is on the y axis and y the +dependent variable is on the y axis + + align:start position:0% +dependent variable is on the y axis + + + align:start position:0% +dependent variable is on the y axis +this is actually plotted in reverse + + align:start position:0% +this is actually plotted in reverse + + + align:start position:0% +this is actually plotted in reverse +because we're varying price as an + + align:start position:0% +because we're varying price as an + + + align:start position:0% +because we're varying price as an +exogenous variable + + align:start position:0% +exogenous variable + + + align:start position:0% +exogenous variable +and plotting the demand + + align:start position:0% +and plotting the demand + + + align:start position:0% +and plotting the demand +no big deal i don't think i can plot it + + align:start position:0% +no big deal i don't think i can plot it + + + align:start position:0% +no big deal i don't think i can plot it +the other way + + align:start position:0% +the other way + + + align:start position:0% +the other way +actually i could but + + align:start position:0% +actually i could but + + + align:start position:0% +actually i could but +you'll see why this + + align:start position:0% +you'll see why this + + + align:start position:0% +you'll see why this +can get confusing right i just thought + + align:start position:0% +can get confusing right i just thought + + + align:start position:0% +can get confusing right i just thought +i'd point it out along the way + + align:start position:0% +i'd point it out along the way + + + align:start position:0% +i'd point it out along the way +okay + + align:start position:0% +okay + + + align:start position:0% +okay +now we come to giffen's paradox + + align:start position:0% +now we come to giffen's paradox + + + align:start position:0% +now we come to giffen's paradox +if the income effect of a price change + + align:start position:0% +if the income effect of a price change + + + align:start position:0% +if the income effect of a price change +is strong enough the change in the price + + align:start position:0% +is strong enough the change in the price + + + align:start position:0% +is strong enough the change in the price +and the resulting change in the quantity + + align:start position:0% +and the resulting change in the quantity + + + align:start position:0% +and the resulting change in the quantity +demanded could actually move in the same + + align:start position:0% +demanded could actually move in the same + + + align:start position:0% +demanded could actually move in the same +direction + + align:start position:0% +direction + + + align:start position:0% +direction +so let me give you an example that's + + align:start position:0% +so let me give you an example that's + + + align:start position:0% +so let me give you an example that's +attributed to robert giffin + + align:start position:0% +attributed to robert giffin + + + align:start position:0% +attributed to robert giffin +who claimed to observe this in ireland + + align:start position:0% +who claimed to observe this in ireland + + + align:start position:0% +who claimed to observe this in ireland +where they had a famine so the potato + + align:start position:0% +where they had a famine so the potato + + + align:start position:0% +where they had a famine so the potato +crop was failing and the price of + + align:start position:0% +crop was failing and the price of + + + align:start position:0% +crop was failing and the price of +potatoes was rising and despite the rise + + align:start position:0% +potatoes was rising and despite the rise + + + align:start position:0% +potatoes was rising and despite the rise +in price people consumed more so the + + align:start position:0% +in price people consumed more so the + + + align:start position:0% +in price people consumed more so the +demand curve was upward sloping not + + align:start position:0% +demand curve was upward sloping not + + + align:start position:0% +demand curve was upward sloping not +downward sloping + + align:start position:0% +downward sloping + + + align:start position:0% +downward sloping +his explanation was potatoes are a big + + align:start position:0% +his explanation was potatoes are a big + + + align:start position:0% +his explanation was potatoes are a big +part of the budget when their price goes + + align:start position:0% +part of the budget when their price goes + + + align:start position:0% +part of the budget when their price goes +up the effective income goes down and + + align:start position:0% +up the effective income goes down and + + + align:start position:0% +up the effective income goes down and +that income effect dominates the lower + + align:start position:0% +that income effect dominates the lower + + + align:start position:0% +that income effect dominates the lower +income effect is what lowers the demand + + align:start position:0% +income effect is what lowers the demand + + + align:start position:0% +income effect is what lowers the demand +for the good but in effect prices go up + + align:start position:0% +for the good but in effect prices go up + + + align:start position:0% +for the good but in effect prices go up +and demand goes + + align:start position:0% +and demand goes + + + align:start position:0% +and demand goes +well + + align:start position:0% +well + + + align:start position:0% +well +income's going down but these this good + + align:start position:0% +income's going down but these this good + + + align:start position:0% +income's going down but these this good +is a necessity so you get sort of a + + align:start position:0% +is a necessity so you get sort of a + + + align:start position:0% +is a necessity so you get sort of a +negative sign on the income effect so + + align:start position:0% +negative sign on the income effect so + + + align:start position:0% +negative sign on the income effect so +the demand is going up so price and + + align:start position:0% +the demand is going up so price and + + + align:start position:0% +the demand is going up so price and +income are going up at the same time + + align:start position:0% +income are going up at the same time + + + align:start position:0% +income are going up at the same time +it's a bit of a mouthful no pun intended + + align:start position:0% +it's a bit of a mouthful no pun intended + + + align:start position:0% +it's a bit of a mouthful no pun intended +actually this could not have happened it + + align:start position:0% +actually this could not have happened it + + + align:start position:0% +actually this could not have happened it +would require that potatoes be an + + align:start position:0% +would require that potatoes be an + + + align:start position:0% +would require that potatoes be an +important part of the budget that + + align:start position:0% +important part of the budget that + + + align:start position:0% +important part of the budget that +potatoes be a necessity but what doesn't + + align:start position:0% +potatoes be a necessity but what doesn't + + + align:start position:0% +potatoes be a necessity but what doesn't +fit the facts is how are they consuming + + align:start position:0% +fit the facts is how are they consuming + + + align:start position:0% +fit the facts is how are they consuming +more potatoes + + align:start position:0% +more potatoes + + + align:start position:0% +more potatoes +when in fact there was a blight and + + align:start position:0% +when in fact there was a blight and + + + align:start position:0% +when in fact there was a blight and +there were no more potatoes to be had + + align:start position:0% +there were no more potatoes to be had + + + align:start position:0% +there were no more potatoes to be had +so something doesn't add up literally + + align:start position:0% +so something doesn't add up literally + + + align:start position:0% +so something doesn't add up literally +anyway all intermediate micro classes + + align:start position:0% +anyway all intermediate micro classes + + + align:start position:0% +anyway all intermediate micro classes +technically fix your feature gif and + + align:start position:0% +technically fix your feature gif and + + + align:start position:0% +technically fix your feature gif and +goods and then move on + + align:start position:0% +goods and then move on + + + align:start position:0% +goods and then move on +and you may be left wondering if it ever + + align:start position:0% +and you may be left wondering if it ever + + + align:start position:0% +and you may be left wondering if it ever +really happens in practice those + + align:start position:0% +really happens in practice those + + + align:start position:0% +really happens in practice those +searching + + align:start position:0% +searching + + + align:start position:0% +searching +around i discovered jensen and miller + + align:start position:0% +around i discovered jensen and miller + + + align:start position:0% +around i discovered jensen and miller +who actually + + align:start position:0% +who actually + + + align:start position:0% +who actually +ran an experiment + + align:start position:0% +ran an experiment + + + align:start position:0% +ran an experiment +so this is literally a randomized + + align:start position:0% +so this is literally a randomized + + + align:start position:0% +so this is literally a randomized +control trial + + align:start position:0% +control trial + + + align:start position:0% +control trial +they went to china two different + + align:start position:0% +they went to china two different + + + align:start position:0% +they went to china two different +provinces looked at relatively poor + + align:start position:0% +provinces looked at relatively poor + + + align:start position:0% +provinces looked at relatively poor +households and changed the price of + + align:start position:0% +households and changed the price of + + + align:start position:0% +households and changed the price of +these staple food item that was a big + + align:start position:0% +these staple food item that was a big + + + align:start position:0% +these staple food item that was a big +part of their budget + + align:start position:0% +part of their budget + + + align:start position:0% +part of their budget +now in order to make the comparison + + align:start position:0% +now in order to make the comparison + + + align:start position:0% +now in order to make the comparison +you've got to change the price so it was + + align:start position:0% +you've got to change the price so it was + + + align:start position:0% +you've got to change the price so it was +a randomized control trial meaning + + align:start position:0% +a randomized control trial meaning + + + align:start position:0% +a randomized control trial meaning +randomly some households were + + align:start position:0% +randomly some households were + + + align:start position:0% +randomly some households were +exposed to a lower price because they + + align:start position:0% +exposed to a lower price because they + + + align:start position:0% +exposed to a lower price because they +were given vouchers so that when they + + align:start position:0% +were given vouchers so that when they + + + align:start position:0% +were given vouchers so that when they +went to the store the sum of you unpaid + + align:start position:0% +went to the store the sum of you unpaid + + + align:start position:0% +went to the store the sum of you unpaid +plus vouchers equaled the stated price + + align:start position:0% +plus vouchers equaled the stated price + + + align:start position:0% +plus vouchers equaled the stated price +but they didn't have to pay for the + + align:start position:0% +but they didn't have to pay for the + + + align:start position:0% +but they didn't have to pay for the +vouchers so effectively from their point + + align:start position:0% +vouchers so effectively from their point + + + align:start position:0% +vouchers so effectively from their point +of view the price was lowered given the + + align:start position:0% +of view the price was lowered given the + + + align:start position:0% +of view the price was lowered given the +vouchers + + align:start position:0% +vouchers + + + align:start position:0% +vouchers +and the control group did not receive + + align:start position:0% +and the control group did not receive + + + align:start position:0% +and the control group did not receive +vouchers so the control group faced the + + align:start position:0% +vouchers so the control group faced the + + + align:start position:0% +vouchers so the control group faced the +normal market price and what jensen and + + align:start position:0% +normal market price and what jensen and + + + align:start position:0% +normal market price and what jensen and +miller are doing is comparing the + + align:start position:0% +miller are doing is comparing the + + + align:start position:0% +miller are doing is comparing the +control group with the treatment group + + align:start position:0% +control group with the treatment group + + + align:start position:0% +control group with the treatment group +and what they discovered was + + align:start position:0% +and what they discovered was + + + align:start position:0% +and what they discovered was +in hunan in the south rice was the + + align:start position:0% +in hunan in the south rice was the + + + align:start position:0% +in hunan in the south rice was the +staple good + + align:start position:0% +staple good + + + align:start position:0% +staple good +in gonzoo it's wheat they did surveys + + align:start position:0% +in gonzoo it's wheat they did surveys + + + align:start position:0% +in gonzoo it's wheat they did surveys +like engel + + align:start position:0% +like engel + + + align:start position:0% +like engel +before during and after the subsidy on + + align:start position:0% +before during and after the subsidy on + + + align:start position:0% +before during and after the subsidy on +both treatment and control groups and + + align:start position:0% +both treatment and control groups and + + + align:start position:0% +both treatment and control groups and +they found strong evidence that poor + + align:start position:0% +they found strong evidence that poor + + + align:start position:0% +they found strong evidence that poor +households in hunan experience this + + align:start position:0% +households in hunan experience this + + + align:start position:0% +households in hunan experience this +giffen behavior with respect to rice + + align:start position:0% +giffen behavior with respect to rice + + + align:start position:0% +giffen behavior with respect to rice +that is to say when the price of rice + + align:start position:0% +that is to say when the price of rice + + + align:start position:0% +that is to say when the price of rice +went down households reduced their + + align:start position:0% +went down households reduced their + + + align:start position:0% +went down households reduced their +demand for rice + + align:start position:0% +demand for rice + + + align:start position:0% +demand for rice +the evidence was + + align:start position:0% +the evidence was + + + align:start position:0% +the evidence was +mixed in the other province and i think + + align:start position:0% +mixed in the other province and i think + + + align:start position:0% +mixed in the other province and i think +i + + align:start position:0% +i + + + align:start position:0% +i +will choose not to say very much about + + align:start position:0% +will choose not to say very much about + + + align:start position:0% +will choose not to say very much about +this there were groups the very poorest + + align:start position:0% +this there were groups the very poorest + + + align:start position:0% +this there were groups the very poorest +and the least poor that responded in + + align:start position:0% +and the least poor that responded in + + + align:start position:0% +and the least poor that responded in +what you might think to be the ordinary + + align:start position:0% +what you might think to be the ordinary + + + align:start position:0% +what you might think to be the ordinary +way with price with demand down sloping + + align:start position:0% +way with price with demand down sloping + + + align:start position:0% +way with price with demand down sloping +but there was a good a group in the + + align:start position:0% +but there was a good a group in the + + + align:start position:0% +but there was a good a group in the +middle between the very poorest and the + + align:start position:0% +middle between the very poorest and the + + + align:start position:0% +middle between the very poorest and the +least poor which exhibited giffen + + align:start position:0% +least poor which exhibited giffen + + + align:start position:0% +least poor which exhibited giffen +behavior + + align:start position:0% +behavior + + + align:start position:0% +behavior +now as it's written on the slide this is + + align:start position:0% +now as it's written on the slide this is + + + align:start position:0% +now as it's written on the slide this is +a bit of a mystery + + align:start position:0% +a bit of a mystery + + + align:start position:0% +a bit of a mystery +why is it that we're getting this + + align:start position:0% +why is it that we're getting this + + + align:start position:0% +why is it that we're getting this +difference across the three groups + + align:start position:0% +difference across the three groups + + + align:start position:0% +difference across the three groups +or two groups plus one + + align:start position:0% +or two groups plus one + + + align:start position:0% +or two groups plus one +and i leave that for you because again + + align:start position:0% +and i leave that for you because again + + + align:start position:0% +and i leave that for you because again +the problem set features the entire + + align:start position:0% +the problem set features the entire + + + align:start position:0% +the problem set features the entire +article we try to make it easy by + + align:start position:0% +article we try to make it easy by + + + align:start position:0% +article we try to make it easy by +highlighting the text but somewhere in + + align:start position:0% +highlighting the text but somewhere in + + + align:start position:0% +highlighting the text but somewhere in +that paper is a discussion of why this + + align:start position:0% +that paper is a discussion of why this + + + align:start position:0% +that paper is a discussion of why this +result which is a bit hard to interpret + + align:start position:0% +result which is a bit hard to interpret + + + align:start position:0% +result which is a bit hard to interpret +here does have and + + align:start position:0% +here does have and + + + align:start position:0% +here does have and +the authors did give it an + + align:start position:0% +the authors did give it an + + + align:start position:0% +the authors did give it an +interpretation so that's advertising to + + align:start position:0% +interpretation so that's advertising to + + + align:start position:0% +interpretation so that's advertising to +go and grab that paper + + align:start position:0% +go and grab that paper + + + align:start position:0% +go and grab that paper +which + + align:start position:0% + + + + align:start position:0% + +yeah so is the demand like the amount of + + align:start position:0% +yeah so is the demand like the amount of + + + align:start position:0% +yeah so is the demand like the amount of +potatoes or rice you're consuming or + + align:start position:0% +potatoes or rice you're consuming or + + + align:start position:0% +potatoes or rice you're consuming or +like the proportion that is of your + + align:start position:0% +like the proportion that is of your + + + align:start position:0% +like the proportion that is of your +income that's increasing + + align:start position:0% +income that's increasing + + + align:start position:0% +income that's increasing +it's the quantity but obviously they + + align:start position:0% +it's the quantity but obviously they + + + align:start position:0% +it's the quantity but obviously they +have the prices + + align:start position:0% +have the prices + + + align:start position:0% +have the prices +so you can look both + + align:start position:0% + + + + align:start position:0% + +but the the definition + + align:start position:0% +but the the definition + + + align:start position:0% +but the the definition +we've been using of a given good + + align:start position:0% +we've been using of a given good + + + align:start position:0% +we've been using of a given good +uh + + align:start position:0% +uh + + + align:start position:0% +uh +oops + + align:start position:0% + + + + align:start position:0% + +well actually it never showed + + align:start position:0% +well actually it never showed + + + align:start position:0% +well actually it never showed +uh but it is the quantity in this case + + align:start position:0% +uh but it is the quantity in this case + + + align:start position:0% +uh but it is the quantity in this case +the quantity of potatoes + + align:start position:0% +the quantity of potatoes + + + align:start position:0% +the quantity of potatoes +not expenditure on potatoes + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +um + + align:start position:0% +um + + + align:start position:0% +um +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now i want to get to something + + align:start position:0% +so now i want to get to something + + + align:start position:0% +so now i want to get to something +effectively we've already been doing + + align:start position:0% +effectively we've already been doing + + + align:start position:0% +effectively we've already been doing +which is + + align:start position:0% +which is + + + align:start position:0% +which is +compensated versus uncompensated demands + + align:start position:0% +compensated versus uncompensated demands + + + align:start position:0% +compensated versus uncompensated demands +so the uncompensated demand is the total + + align:start position:0% +so the uncompensated demand is the total + + + align:start position:0% +so the uncompensated demand is the total +demand sometimes called the marshallian + + align:start position:0% +demand sometimes called the marshallian + + + align:start position:0% +demand sometimes called the marshallian +demand + + align:start position:0% +demand + + + align:start position:0% +demand +from + + align:start position:0% +from + + + align:start position:0% +from +marshall who was an early english + + align:start position:0% +marshall who was an early english + + + align:start position:0% +marshall who was an early english +economist it shows the relationship + + align:start position:0% +economist it shows the relationship + + + align:start position:0% +economist it shows the relationship +between price of the good and the + + align:start position:0% +between price of the good and the + + + align:start position:0% +between price of the good and the +quantity purchased assuming that all + + align:start position:0% +quantity purchased assuming that all + + + align:start position:0% +quantity purchased assuming that all +other prices and income are held + + align:start position:0% +other prices and income are held + + + align:start position:0% +other prices and income are held +constant the compensated demand + + align:start position:0% +constant the compensated demand + + + align:start position:0% +constant the compensated demand +sometimes called the hixian demand shows + + align:start position:0% +sometimes called the hixian demand shows + + + align:start position:0% +sometimes called the hixian demand shows +the relationship between price and + + align:start position:0% +the relationship between price and + + + align:start position:0% +the relationship between price and +quantity it continues to assume that all + + align:start position:0% +quantity it continues to assume that all + + + align:start position:0% +quantity it continues to assume that all +the other prices are held fixed but + + align:start position:0% +the other prices are held fixed but + + + align:start position:0% +the other prices are held fixed but +instead of holding income fixed utility + + align:start position:0% +instead of holding income fixed utility + + + align:start position:0% +instead of holding income fixed utility +is held fixed so to go back to the + + align:start position:0% +is held fixed so to go back to the + + + align:start position:0% +is held fixed so to go back to the +earlier slides we were featuring the + + align:start position:0% +earlier slides we were featuring the + + + align:start position:0% +earlier slides we were featuring the +substitution effect as the movement + + align:start position:0% +substitution effect as the movement + + + align:start position:0% +substitution effect as the movement +along an indifference curve i.e holding + + align:start position:0% +along an indifference curve i.e holding + + + align:start position:0% +along an indifference curve i.e holding +utility fixed so when we looked at how + + align:start position:0% +utility fixed so when we looked at how + + + align:start position:0% +utility fixed so when we looked at how +much demand would change + + align:start position:0% +much demand would change + + + align:start position:0% +much demand would change +one way or the other as a function of + + align:start position:0% +one way or the other as a function of + + + align:start position:0% +one way or the other as a function of +the price change + + align:start position:0% +the price change + + + align:start position:0% +the price change +and we + + align:start position:0% +and we + + + align:start position:0% +and we +went along the initial baseline + + align:start position:0% +went along the initial baseline + + + align:start position:0% +went along the initial baseline +indifference curve that was the + + align:start position:0% +indifference curve that was the + + + align:start position:0% +indifference curve that was the +compensated demand + + align:start position:0% +compensated demand + + + align:start position:0% +compensated demand +so + + align:start position:0% +so + + + align:start position:0% +so +more dramatically + + align:start position:0% +more dramatically + + + align:start position:0% +more dramatically +if we fix the initial + + align:start position:0% +if we fix the initial + + + align:start position:0% +if we fix the initial +point and change the price we would be + + align:start position:0% +point and change the price we would be + + + align:start position:0% +point and change the price we would be +for lower price pivoting along this + + align:start position:0% +for lower price pivoting along this + + + align:start position:0% +for lower price pivoting along this +indifference curve u2 + + align:start position:0% +indifference curve u2 + + + align:start position:0% +indifference curve u2 +by construction + + align:start position:0% +by construction + + + align:start position:0% +by construction +we keep utility constant at u2 + + align:start position:0% +we keep utility constant at u2 + + + align:start position:0% +we keep utility constant at u2 +and then plot the demands + + align:start position:0% +and then plot the demands + + + align:start position:0% +and then plot the demands +which are going up and we put that on + + align:start position:0% +which are going up and we put that on + + + align:start position:0% +which are going up and we put that on +the price quantity diagram and the + + align:start position:0% +the price quantity diagram and the + + + align:start position:0% +the price quantity diagram and the +demand curve is sloping down but this is + + align:start position:0% +demand curve is sloping down but this is + + + align:start position:0% +demand curve is sloping down but this is +the hixian demand that little h to + + align:start position:0% +the hixian demand that little h to + + + align:start position:0% +the hixian demand that little h to +remind us that it's hixed + + align:start position:0% +remind us that it's hixed + + + align:start position:0% +remind us that it's hixed +so + + align:start position:0% +so + + + align:start position:0% +so +putting both + + align:start position:0% +putting both + + + align:start position:0% +putting both +types of demand on the same diagram + + align:start position:0% +types of demand on the same diagram + + + align:start position:0% +types of demand on the same diagram +we have the normal demand of the + + align:start position:0% +we have the normal demand of the + + + align:start position:0% +we have the normal demand of the +marshalling demand + + align:start position:0% +marshalling demand + + + align:start position:0% +marshalling demand +and h for the hixian demand + + align:start position:0% +and h for the hixian demand + + + align:start position:0% +and h for the hixian demand +so as price goes down demand goes up but + + align:start position:0% +so as price goes down demand goes up but + + + align:start position:0% +so as price goes down demand goes up but +the demand goes up from two different + + align:start position:0% +the demand goes up from two different + + + align:start position:0% +the demand goes up from two different +effects one is the substitution effect + + align:start position:0% +effects one is the substitution effect + + + align:start position:0% +effects one is the substitution effect +holding utility constant and that's a + + align:start position:0% +holding utility constant and that's a + + + align:start position:0% +holding utility constant and that's a +point on the hixian demand + + align:start position:0% +point on the hixian demand + + + align:start position:0% +point on the hixian demand +and then the rest of it is this movement + + align:start position:0% +and then the rest of it is this movement + + + align:start position:0% +and then the rest of it is this movement +to the marshallian demand or ordinary + + align:start position:0% +to the marshallian demand or ordinary + + + align:start position:0% +to the marshallian demand or ordinary +demand which is the income effect that + + align:start position:0% +demand which is the income effect that + + + align:start position:0% +demand which is the income effect that +comes from the lower price + + align:start position:0% +comes from the lower price + + + align:start position:0% +comes from the lower price +and obviously we can go in the other + + align:start position:0% +and obviously we can go in the other + + + align:start position:0% +and obviously we can go in the other +direction starting here as sort of a + + align:start position:0% +direction starting here as sort of a + + + align:start position:0% +direction starting here as sort of a +baseline + + align:start position:0% +baseline + + + align:start position:0% +baseline +if we + + align:start position:0% +if we + + + align:start position:0% +if we +increase the price we would pivot along + + align:start position:0% +increase the price we would pivot along + + + align:start position:0% +increase the price we would pivot along +the indifference curve + + align:start position:0% +the indifference curve + + + align:start position:0% +the indifference curve +and get a lower demand due to the + + align:start position:0% +and get a lower demand due to the + + + align:start position:0% +and get a lower demand due to the +substitution effect but effective income + + align:start position:0% +substitution effect but effective income + + + align:start position:0% +substitution effect but effective income +has gone down so this sort of negative + + align:start position:0% +has gone down so this sort of negative + + + align:start position:0% +has gone down so this sort of negative +income effect kicks in and demand is + + align:start position:0% +income effect kicks in and demand is + + + align:start position:0% +income effect kicks in and demand is +even less + + align:start position:0% +even less + + + align:start position:0% +even less +so kind of intuitively the hixian demand + + align:start position:0% +so kind of intuitively the hixian demand + + + align:start position:0% +so kind of intuitively the hixian demand +is steeper than + + align:start position:0% +is steeper than + + + align:start position:0% +is steeper than +the ordinary demand curve because it has + + align:start position:0% +the ordinary demand curve because it has + + + align:start position:0% +the ordinary demand curve because it has +included those income effects + + align:start position:0% +included those income effects + + + align:start position:0% +included those income effects +or putting in another way the ordinary + + align:start position:0% +or putting in another way the ordinary + + + align:start position:0% +or putting in another way the ordinary +demand curve is quote flatter with a + + align:start position:0% +demand curve is quote flatter with a + + + align:start position:0% +demand curve is quote flatter with a +lower slope + + align:start position:0% +lower slope + + + align:start position:0% +lower slope +because there's a more dramatic larger + + align:start position:0% +because there's a more dramatic larger + + + align:start position:0% +because there's a more dramatic larger +change in the quantity as we change the + + align:start position:0% +change in the quantity as we change the + + + align:start position:0% +change in the quantity as we change the +price either the income effect is + + align:start position:0% +price either the income effect is + + + align:start position:0% +price either the income effect is +positive and demand goes up all the more + + align:start position:0% +positive and demand goes up all the more + + + align:start position:0% +positive and demand goes up all the more +or the income effect is negative and the + + align:start position:0% +or the income effect is negative and the + + + align:start position:0% +or the income effect is negative and the +demand decreases all the more + + align:start position:0% +demand decreases all the more + + + align:start position:0% +demand decreases all the more +so we could say be careful about this + + align:start position:0% +so we could say be careful about this + + + align:start position:0% +so we could say be careful about this +that in some sense the ordinary demand + + align:start position:0% +that in some sense the ordinary demand + + + align:start position:0% +that in some sense the ordinary demand +curve is more elastic at least here it + + align:start position:0% +curve is more elastic at least here it + + + align:start position:0% +curve is more elastic at least here it +has a higher derivative + + align:start position:0% +has a higher derivative + + + align:start position:0% +has a higher derivative +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +there's a mathematical expression + + align:start position:0% +there's a mathematical expression + + + align:start position:0% +there's a mathematical expression +for the difference between the hixian + + align:start position:0% +for the difference between the hixian + + + align:start position:0% +for the difference between the hixian +demand and the ordinary demand + + align:start position:0% +demand and the ordinary demand + + + align:start position:0% +demand and the ordinary demand +namely the derivative of demand of good + + align:start position:0% +namely the derivative of demand of good + + + align:start position:0% +namely the derivative of demand of good +x as we change the price of x the slope + + align:start position:0% +x as we change the price of x the slope + + + align:start position:0% +x as we change the price of x the slope +of the ordinary demand curve is first + + align:start position:0% +of the ordinary demand curve is first + + + align:start position:0% +of the ordinary demand curve is first +term + + align:start position:0% +term + + + align:start position:0% +term +the substitution effect of the price + + align:start position:0% +the substitution effect of the price + + + align:start position:0% +the substitution effect of the price +change px but then this income effect + + align:start position:0% +change px but then this income effect + + + align:start position:0% +change px but then this income effect +kicks in + + align:start position:0% +kicks in + + + align:start position:0% +kicks in +and there's two pieces to the income + + align:start position:0% +and there's two pieces to the income + + + align:start position:0% +and there's two pieces to the income +effect + + align:start position:0% +effect + + + align:start position:0% +effect +one has to do with how high is the + + align:start position:0% +one has to do with how high is the + + + align:start position:0% +one has to do with how high is the +marginal change in x as you change + + align:start position:0% +marginal change in x as you change + + + align:start position:0% +marginal change in x as you change +income the other is how much x you were + + align:start position:0% +income the other is how much x you were + + + align:start position:0% +income the other is how much x you were +eating to begin with you know think of + + align:start position:0% +eating to begin with you know think of + + + align:start position:0% +eating to begin with you know think of +potatoes and so on + + align:start position:0% +potatoes and so on + + + align:start position:0% +potatoes and so on +or those budget shares either angle or + + align:start position:0% +or those budget shares either angle or + + + align:start position:0% +or those budget shares either angle or +but this is x this is the quantity so it + + align:start position:0% +but this is x this is the quantity so it + + + align:start position:0% +but this is x this is the quantity so it +looks from this since we're subtracting + + align:start position:0% +looks from this since we're subtracting + + + align:start position:0% +looks from this since we're subtracting +say the income is factor is positive and + + align:start position:0% +say the income is factor is positive and + + + align:start position:0% +say the income is factor is positive and +x is positive then we're subtracting a + + align:start position:0% +x is positive then we're subtracting a + + + align:start position:0% +x is positive then we're subtracting a +positive number so it looks like this + + align:start position:0% +positive number so it looks like this + + + align:start position:0% +positive number so it looks like this +minus this must be lower than this so it + + align:start position:0% +minus this must be lower than this so it + + + align:start position:0% +minus this must be lower than this so it +looks like the ordinary demand should + + align:start position:0% +looks like the ordinary demand should + + + align:start position:0% +looks like the ordinary demand should +have a lower slope if this equation is + + align:start position:0% +have a lower slope if this equation is + + + align:start position:0% +have a lower slope if this equation is +accurate but in fact as i just said it's + + align:start position:0% +accurate but in fact as i just said it's + + + align:start position:0% +accurate but in fact as i just said it's +the other way around puzzle puzzle + + align:start position:0% +the other way around puzzle puzzle + + + align:start position:0% +the other way around puzzle puzzle +puzzle what's going on well it's this + + align:start position:0% +puzzle what's going on well it's this + + + align:start position:0% +puzzle what's going on well it's this +stupid way that we traditionally plot + + align:start position:0% +stupid way that we traditionally plot + + + align:start position:0% +stupid way that we traditionally plot +the dependent variable on the x axis + + align:start position:0% +the dependent variable on the x axis + + + align:start position:0% +the dependent variable on the x axis +so you know this is dx dp + + align:start position:0% +so you know this is dx dp + + + align:start position:0% +so you know this is dx dp +the response of the dependent variable + + align:start position:0% +the response of the dependent variable + + + align:start position:0% +the response of the dependent variable +to the independent variable which is you + + align:start position:0% +to the independent variable which is you + + + align:start position:0% +to the independent variable which is you +know one over the slope of this so this + + align:start position:0% +know one over the slope of this so this + + + align:start position:0% +know one over the slope of this so this +diagram is consistent with this equation + + align:start position:0% +diagram is consistent with this equation + + + align:start position:0% +diagram is consistent with this equation +it just takes a little bit of juggling + + align:start position:0% +it just takes a little bit of juggling + + + align:start position:0% +it just takes a little bit of juggling +to realize why + + align:start position:0% +to realize why + + + align:start position:0% +to realize why +anyway this is called slutsky's equation + + align:start position:0% +anyway this is called slutsky's equation + + + align:start position:0% +anyway this is called slutsky's equation +and again at the risk of trying to do + + align:start position:0% +and again at the risk of trying to do + + + align:start position:0% +and again at the risk of trying to do +too much too fast but on the other hand + + align:start position:0% +too much too fast but on the other hand + + + align:start position:0% +too much too fast but on the other hand +providing some motivation for where + + align:start position:0% +providing some motivation for where + + + align:start position:0% +providing some motivation for where +we're going eventually we'll get to + + align:start position:0% +we're going eventually we'll get to + + + align:start position:0% +we're going eventually we'll get to +lecture 19 and talk about whether there + + align:start position:0% +lecture 19 and talk about whether there + + + align:start position:0% +lecture 19 and talk about whether there +are rejectable restrictions on data as + + align:start position:0% +are rejectable restrictions on data as + + + align:start position:0% +are rejectable restrictions on data as +in the science lecture we have a model + + align:start position:0% +in the science lecture we have a model + + + align:start position:0% +in the science lecture we have a model +does the model fit the data or not can + + align:start position:0% +does the model fit the data or not can + + + align:start position:0% +does the model fit the data or not can +you even reject the model + + align:start position:0% +you even reject the model + + + align:start position:0% +you even reject the model +is it providing some guidance or you can + + align:start position:0% +is it providing some guidance or you can + + + align:start position:0% +is it providing some guidance or you can +always tweak things so the model is + + align:start position:0% +always tweak things so the model is + + + align:start position:0% +always tweak things so the model is +always true so this lecture 19 is about + + align:start position:0% +always true so this lecture 19 is about + + + align:start position:0% +always true so this lecture 19 is about +restrictions that can be tested + + align:start position:0% +restrictions that can be tested + + + align:start position:0% +restrictions that can be tested +and there's something called slutsky + + align:start position:0% +and there's something called slutsky + + + align:start position:0% +and there's something called slutsky +same guy + + align:start position:0% +same guy + + + align:start position:0% +same guy +slutsky's decomposition this equation is + + align:start position:0% +slutsky's decomposition this equation is + + + align:start position:0% +slutsky's decomposition this equation is +a generalization of the one i was just + + align:start position:0% +a generalization of the one i was just + + + align:start position:0% +a generalization of the one i was just +showing you with the exception that we + + align:start position:0% +showing you with the exception that we + + + align:start position:0% +showing you with the exception that we +put this substitution effect on the left + + align:start position:0% +put this substitution effect on the left + + + align:start position:0% +put this substitution effect on the left +and the regular derivative on the right + + align:start position:0% +and the regular derivative on the right + + + align:start position:0% +and the regular derivative on the right +so it looks like the signs are changing + + align:start position:0% +so it looks like the signs are changing + + + align:start position:0% +so it looks like the signs are changing +this becomes a plus + + align:start position:0% +this becomes a plus + + + align:start position:0% +this becomes a plus +this is a generalization in a number of + + align:start position:0% +this is a generalization in a number of + + + align:start position:0% +this is a generalization in a number of +respects + + align:start position:0% +respects + + + align:start position:0% +respects +we're looking at the demand for good l + + align:start position:0% +we're looking at the demand for good l + + + align:start position:0% +we're looking at the demand for good l +as we change the price of another good + + align:start position:0% +as we change the price of another good + + + align:start position:0% +as we change the price of another good +good k + + align:start position:0% +good k + + + align:start position:0% +good k +not the own effect + + align:start position:0% +not the own effect + + + align:start position:0% +not the own effect +of one good with respect to its own + + align:start position:0% +of one good with respect to its own + + + align:start position:0% +of one good with respect to its own +price but sort of a cross partial + + align:start position:0% +price but sort of a cross partial + + + align:start position:0% +price but sort of a cross partial +derivative although we still have this + + align:start position:0% +derivative although we still have this + + + align:start position:0% +derivative although we still have this +income effect over here and we're still + + align:start position:0% +income effect over here and we're still + + + align:start position:0% +income effect over here and we're still +weighting it by the initial quantity + + align:start position:0% +weighting it by the initial quantity + + + align:start position:0% +weighting it by the initial quantity +purchased so it turns out that + + align:start position:0% +purchased so it turns out that + + + align:start position:0% +purchased so it turns out that +what we want to do is ask whether + + align:start position:0% +what we want to do is ask whether + + + align:start position:0% +what we want to do is ask whether +observe demands + + align:start position:0% +observe demands + + + align:start position:0% +observe demands +this guy + + align:start position:0% +this guy + + + align:start position:0% +this guy +these guys really how demand is changing + + align:start position:0% +these guys really how demand is changing + + + align:start position:0% +these guys really how demand is changing +with prices and income whether there are + + align:start position:0% +with prices and income whether there are + + + align:start position:0% +with prices and income whether there are +patterns which could be rejected as + + align:start position:0% +patterns which could be rejected as + + + align:start position:0% +patterns which could be rejected as +being inconsistent with a model and the + + align:start position:0% +being inconsistent with a model and the + + + align:start position:0% +being inconsistent with a model and the +problem is that the restrictions are on + + align:start position:0% +problem is that the restrictions are on + + + align:start position:0% +problem is that the restrictions are on +these pixian demands and we don't see + + align:start position:0% +these pixian demands and we don't see + + + align:start position:0% +these pixian demands and we don't see +those we see the regular demands we + + align:start position:0% +those we see the regular demands we + + + align:start position:0% +those we see the regular demands we +don't see the hixing demands but it and + + align:start position:0% +don't see the hixing demands but it and + + + align:start position:0% +don't see the hixing demands but it and +i'll say more about this in a minute + + align:start position:0% +i'll say more about this in a minute + + + align:start position:0% +i'll say more about this in a minute +it turns out that with some math you can + + align:start position:0% +it turns out that with some math you can + + + align:start position:0% +it turns out that with some math you can +actually go back and forth between the + + align:start position:0% +actually go back and forth between the + + + align:start position:0% +actually go back and forth between the +regular demand and the hixian demand and + + align:start position:0% +regular demand and the hixian demand and + + + align:start position:0% +regular demand and the hixian demand and +there are restrictions so anyway i'm + + align:start position:0% +there are restrictions so anyway i'm + + + align:start position:0% +there are restrictions so anyway i'm +running an experiment now + + align:start position:0% +running an experiment now + + + align:start position:0% +running an experiment now +because i'm showing you things that are + + align:start position:0% +because i'm showing you things that are + + + align:start position:0% +because i'm showing you things that are +more toward the end of the class lecture + + align:start position:0% +more toward the end of the class lecture + + + align:start position:0% +more toward the end of the class lecture +set of lectures than at the beginning + + align:start position:0% +set of lectures than at the beginning + + + align:start position:0% +set of lectures than at the beginning +but but since we're introducing + + align:start position:0% +but but since we're introducing + + + align:start position:0% +but but since we're introducing +slutsky's equation today i thought i'd + + align:start position:0% +slutsky's equation today i thought i'd + + + align:start position:0% +slutsky's equation today i thought i'd +show you that we will come back to it + + align:start position:0% +show you that we will come back to it + + + align:start position:0% +show you that we will come back to it +and and use it in a subsequent lecture + + align:start position:0% +and and use it in a subsequent lecture + + + align:start position:0% +and and use it in a subsequent lecture +this is a lot simpler notation + + align:start position:0% +this is a lot simpler notation + + + align:start position:0% +this is a lot simpler notation +and don't worry about either the income + + align:start position:0% +and don't worry about either the income + + + align:start position:0% +and don't worry about either the income +expansion paths or this generalization + + align:start position:0% +expansion paths or this generalization + + + align:start position:0% +expansion paths or this generalization +of slutsky that was meant to be a + + align:start position:0% +of slutsky that was meant to be a + + + align:start position:0% +of slutsky that was meant to be a +preview of coming attractions and + + align:start position:0% +preview of coming attractions and + + + align:start position:0% +preview of coming attractions and +motivation not something you should be + + align:start position:0% +motivation not something you should be + + + align:start position:0% +motivation not something you should be +worried about learning right away + + align:start position:0% +worried about learning right away + + + align:start position:0% +worried about learning right away +so + + align:start position:0% +so + + + align:start position:0% +so +now i want to introduce something called + + align:start position:0% +now i want to introduce something called + + + align:start position:0% +now i want to introduce something called +duality + + align:start position:0% +duality + + + align:start position:0% +duality +this looks like an income expansion path + + align:start position:0% +this looks like an income expansion path + + + align:start position:0% +this looks like an income expansion path +as we increase income we get more and + + align:start position:0% +as we increase income we get more and + + + align:start position:0% +as we increase income we get more and +more points + + align:start position:0% +more points + + + align:start position:0% +more points +i think this is identical with the + + align:start position:0% +i think this is identical with the + + + align:start position:0% +i think this is identical with the +figure i showed you earlier + + align:start position:0% +figure i showed you earlier + + + align:start position:0% +figure i showed you earlier +but i want to use it for a different + + align:start position:0% +but i want to use it for a different + + + align:start position:0% +but i want to use it for a different +purpose + + align:start position:0% +purpose + + + align:start position:0% +purpose +i want to say + + align:start position:0% +i want to say + + + align:start position:0% +i want to say +suppose we're at this point with this + + align:start position:0% +suppose we're at this point with this + + + align:start position:0% +suppose we're at this point with this +intermediate income i2 + + align:start position:0% +intermediate income i2 + + + align:start position:0% +intermediate income i2 +then we could be maximizing utility + + align:start position:0% +then we could be maximizing utility + + + align:start position:0% +then we could be maximizing utility +subject to that income level holding + + align:start position:0% +subject to that income level holding + + + align:start position:0% +subject to that income level holding +price is fixed and that would be x2 y2 + + align:start position:0% +price is fixed and that would be x2 y2 + + + align:start position:0% +price is fixed and that would be x2 y2 +would be the maximal point of utility + + align:start position:0% +would be the maximal point of utility + + + align:start position:0% +would be the maximal point of utility +but suppose we did a different + + align:start position:0% +but suppose we did a different + + + align:start position:0% +but suppose we did a different +experiment + + align:start position:0% +experiment + + + align:start position:0% +experiment +suppose we wanted to achieve + + align:start position:0% +suppose we wanted to achieve + + + align:start position:0% +suppose we wanted to achieve +this utility level u2 by spending as + + align:start position:0% +this utility level u2 by spending as + + + align:start position:0% +this utility level u2 by spending as +little as possible the amount spent + + align:start position:0% +little as possible the amount spent + + + align:start position:0% +little as possible the amount spent +would be captured by these various + + align:start position:0% +would be captured by these various + + + align:start position:0% +would be captured by these various +possible budget lines so something + + align:start position:0% +possible budget lines so something + + + align:start position:0% +possible budget lines so something +called a minimizing expenditure problem + + align:start position:0% +called a minimizing expenditure problem + + + align:start position:0% +called a minimizing expenditure problem +minimal expenditure problem + + align:start position:0% +minimal expenditure problem + + + align:start position:0% +minimal expenditure problem +would be to find the budget line which + + align:start position:0% +would be to find the budget line which + + + align:start position:0% +would be to find the budget line which +is lowest closest to zero zero and still + + align:start position:0% +is lowest closest to zero zero and still + + + align:start position:0% +is lowest closest to zero zero and still +allows the household to get the utility + + align:start position:0% +allows the household to get the utility + + + align:start position:0% +allows the household to get the utility +level u2 + + align:start position:0% +level u2 + + + align:start position:0% +level u2 +so at this point it's clear you could + + align:start position:0% +so at this point it's clear you could + + + align:start position:0% +so at this point it's clear you could +think of this as maximizing utility + + align:start position:0% +think of this as maximizing utility + + + align:start position:0% +think of this as maximizing utility +subject to a fixed budget or minimizing + + align:start position:0% +subject to a fixed budget or minimizing + + + align:start position:0% +subject to a fixed budget or minimizing +the expenses to get to a fixed level of + + align:start position:0% +the expenses to get to a fixed level of + + + align:start position:0% +the expenses to get to a fixed level of +utility + + align:start position:0% +utility + + + align:start position:0% +utility +both things are true and you can go back + + align:start position:0% +both things are true and you can go back + + + align:start position:0% +both things are true and you can go back +and forth and that is the essential idea + + align:start position:0% +and forth and that is the essential idea + + + align:start position:0% +and forth and that is the essential idea +of duality + + align:start position:0% +of duality + + + align:start position:0% +of duality +okay let's do it little bit more with + + align:start position:0% +okay let's do it little bit more with + + + align:start position:0% +okay let's do it little bit more with +notation + + align:start position:0% +notation + + + align:start position:0% +notation +let's take a consumer with a consumption + + align:start position:0% +let's take a consumer with a consumption + + + align:start position:0% +let's take a consumer with a consumption +set + + align:start position:0% +set + + + align:start position:0% +set +an l dimensional commodity space with + + align:start position:0% +an l dimensional commodity space with + + + align:start position:0% +an l dimensional commodity space with +the + + align:start position:0% +the + + + align:start position:0% +the +preferences represented by a continuous + + align:start position:0% +preferences represented by a continuous + + + align:start position:0% +preferences represented by a continuous +utility function + + align:start position:0% +utility function + + + align:start position:0% +utility function +and let's look at the utility + + align:start position:0% +and let's look at the utility + + + align:start position:0% +and let's look at the utility +maximization problem + + align:start position:0% +maximization problem + + + align:start position:0% +maximization problem +ump for short + + align:start position:0% +ump for short + + + align:start position:0% +ump for short +which is to maximize utility + + align:start position:0% +which is to maximize utility + + + align:start position:0% +which is to maximize utility +subject to being within the budget so + + align:start position:0% +subject to being within the budget so + + + align:start position:0% +subject to being within the budget so +this says choose a point in the + + align:start position:0% +this says choose a point in the + + + align:start position:0% +this says choose a point in the +consumption set + + align:start position:0% +consumption set + + + align:start position:0% +consumption set +all of the positive ortho + + align:start position:0% +all of the positive ortho + + + align:start position:0% +all of the positive ortho +which maximizes that utility function + + align:start position:0% +which maximizes that utility function + + + align:start position:0% +which maximizes that utility function +subject to the points under + + align:start position:0% +subject to the points under + + + align:start position:0% +subject to the points under +consideration have to be such that when + + align:start position:0% +consideration have to be such that when + + + align:start position:0% +consideration have to be such that when +you take the dot product of p and x p 1 + + align:start position:0% +you take the dot product of p and x p 1 + + + align:start position:0% +you take the dot product of p and x p 1 +x 1 plus p 2 x 2 dot dot it cannot + + align:start position:0% +x 1 plus p 2 x 2 dot dot it cannot + + + align:start position:0% +x 1 plus p 2 x 2 dot dot it cannot +exceed wealth or income so that's the + + align:start position:0% +exceed wealth or income so that's the + + + align:start position:0% +exceed wealth or income so that's the +utility maximization problem + + align:start position:0% +utility maximization problem + + + align:start position:0% +utility maximization problem +the + + align:start position:0% +the + + + align:start position:0% +the +result of solving the maximization + + align:start position:0% +result of solving the maximization + + + align:start position:0% +result of solving the maximization +problem + + align:start position:0% +problem + + + align:start position:0% +problem +can be substituted into utility in other + + align:start position:0% +can be substituted into utility in other + + + align:start position:0% +can be substituted into utility in other +words utility at the maximal solution + + align:start position:0% +words utility at the maximal solution + + + align:start position:0% +words utility at the maximal solution +and we're going to call that the value + + align:start position:0% +and we're going to call that the value + + + align:start position:0% +and we're going to call that the value +function or indirect utility function + + align:start position:0% +function or indirect utility function + + + align:start position:0% +function or indirect utility function +note that the maximized utility is a + + align:start position:0% +note that the maximized utility is a + + + align:start position:0% +note that the maximized utility is a +function of the parameters or the + + align:start position:0% +function of the parameters or the + + + align:start position:0% +function of the parameters or the +exogenous variables of the problem + + align:start position:0% +exogenous variables of the problem + + + align:start position:0% +exogenous variables of the problem +namely the price vector p + + align:start position:0% +namely the price vector p + + + align:start position:0% +namely the price vector p +and wealth w + + align:start position:0% +and wealth w + + + align:start position:0% +and wealth w +now + + align:start position:0% +now + + + align:start position:0% +now +in contrast the expenditure minimization + + align:start position:0% +in contrast the expenditure minimization + + + align:start position:0% +in contrast the expenditure minimization +problem emp + + align:start position:0% +problem emp + + + align:start position:0% +problem emp +is to + + align:start position:0% +is to + + + align:start position:0% +is to +given a certain level of utility + + align:start position:0% +given a certain level of utility + + + align:start position:0% +given a certain level of utility +minimize + + align:start position:0% +minimize + + + align:start position:0% +minimize +expenditures the dot product p dot x + + align:start position:0% +expenditures the dot product p dot x + + + align:start position:0% +expenditures the dot product p dot x +uh that allows you to achieve at least + + align:start position:0% +uh that allows you to achieve at least + + + align:start position:0% +uh that allows you to achieve at least +that utility + + align:start position:0% +that utility + + + align:start position:0% +that utility +getting more is fine but you know + + align:start position:0% +getting more is fine but you know + + + align:start position:0% +getting more is fine but you know +in most of the figures we show they'll + + align:start position:0% +in most of the figures we show they'll + + + align:start position:0% +in most of the figures we show they'll +this will be at inequality but just like + + align:start position:0% +this will be at inequality but just like + + + align:start position:0% +this will be at inequality but just like +you could spend less than your + + align:start position:0% +you could spend less than your + + + align:start position:0% +you could spend less than your +income in principle here you could + + align:start position:0% +income in principle here you could + + + align:start position:0% +income in principle here you could +achieve a higher level of utility but + + align:start position:0% +achieve a higher level of utility but + + + align:start position:0% +achieve a higher level of utility but +whatever you're doing here in the + + align:start position:0% +whatever you're doing here in the + + + align:start position:0% +whatever you're doing here in the +expenditure minimization problem you're + + align:start position:0% +expenditure minimization problem you're + + + align:start position:0% +expenditure minimization problem you're +trying to minimize total expenditures + + align:start position:0% +trying to minimize total expenditures + + + align:start position:0% +trying to minimize total expenditures +and we call the solution to that the e + + align:start position:0% +and we call the solution to that the e + + + align:start position:0% +and we call the solution to that the e +for expenditure + + align:start position:0% +for expenditure + + + align:start position:0% +for expenditure +minimum is a minimized expenditure at + + align:start position:0% +minimum is a minimized expenditure at + + + align:start position:0% +minimum is a minimized expenditure at +the optimum is a function of the + + align:start position:0% +the optimum is a function of the + + + align:start position:0% +the optimum is a function of the +parameters of the problem the same price + + align:start position:0% +parameters of the problem the same price + + + align:start position:0% +parameters of the problem the same price +vector p + + align:start position:0% +vector p + + + align:start position:0% +vector p +but now what's taken as a given is u + + align:start position:0% +but now what's taken as a given is u + + + align:start position:0% +but now what's taken as a given is u +not w but u + + align:start position:0% +not w but u + + + align:start position:0% +not w but u +so we'll have this + + align:start position:0% +so we'll have this + + + align:start position:0% +so we'll have this +notation for value function and + + align:start position:0% +notation for value function and + + + align:start position:0% +notation for value function and +expenditure functions + + align:start position:0% +expenditure functions + + + align:start position:0% +expenditure functions +expenditure functions and demands for + + align:start position:0% +expenditure functions and demands for + + + align:start position:0% +expenditure functions and demands for +that matter have certain properties + + align:start position:0% +that matter have certain properties + + + align:start position:0% +that matter have certain properties +it turns out the expenditure function is + + align:start position:0% +it turns out the expenditure function is + + + align:start position:0% +it turns out the expenditure function is +concave + + align:start position:0% +concave + + + align:start position:0% +concave +and the derivative of the expenditure + + align:start position:0% +and the derivative of the expenditure + + + align:start position:0% +and the derivative of the expenditure +function is demand + + align:start position:0% +function is demand + + + align:start position:0% +function is demand +so when you take the second derivative + + align:start position:0% +so when you take the second derivative + + + align:start position:0% +so when you take the second derivative +of demand + + align:start position:0% +of demand + + + align:start position:0% +of demand +it picks up the concavity of the level + + align:start position:0% +it picks up the concavity of the level + + + align:start position:0% +it picks up the concavity of the level +expenditure function + + align:start position:0% +expenditure function + + + align:start position:0% +expenditure function +and that's why + + align:start position:0% +and that's why + + + align:start position:0% +and that's why +that slutsky equation holds because + + align:start position:0% +that slutsky equation holds because + + + align:start position:0% +that slutsky equation holds because +we're looking at the matrix of second + + align:start position:0% +we're looking at the matrix of second + + + align:start position:0% +we're looking at the matrix of second +order conditions effectively + + align:start position:0% +order conditions effectively + + + align:start position:0% +order conditions effectively +but again just ignore me if that's + + align:start position:0% +but again just ignore me if that's + + + align:start position:0% +but again just ignore me if that's +confusing we'll get there in that + + align:start position:0% +confusing we'll get there in that + + + align:start position:0% +confusing we'll get there in that +lecture 19. for now i just want to focus + + align:start position:0% +lecture 19. for now i just want to focus + + + align:start position:0% +lecture 19. for now i just want to focus +on this + + align:start position:0% +on this + + + align:start position:0% +on this +relationship this duality and there's a + + align:start position:0% +relationship this duality and there's a + + + align:start position:0% +relationship this duality and there's a +number of ways to put it the notation is + + align:start position:0% +number of ways to put it the notation is + + + align:start position:0% +number of ways to put it the notation is +surprisingly subtle but if you work + + align:start position:0% +surprisingly subtle but if you work + + + align:start position:0% +surprisingly subtle but if you work +through it it's fine so suppose we're + + align:start position:0% +through it it's fine so suppose we're + + + align:start position:0% +through it it's fine so suppose we're +given a continuous utility function + + align:start position:0% +given a continuous utility function + + + align:start position:0% +given a continuous utility function +representing locally non-satiated + + align:start position:0% +representing locally non-satiated + + + align:start position:0% +representing locally non-satiated +preferences with a consumption set + + align:start position:0% +preferences with a consumption set + + + align:start position:0% +preferences with a consumption set +strictly positive price vector if x star + + align:start position:0% +strictly positive price vector if x star + + + align:start position:0% +strictly positive price vector if x star +is optimal under the utility max problem + + align:start position:0% +is optimal under the utility max problem + + + align:start position:0% +is optimal under the utility max problem +for a given wealth at those prices then + + align:start position:0% +for a given wealth at those prices then + + + align:start position:0% +for a given wealth at those prices then +x-star is optimal in the expenditure + + align:start position:0% +x-star is optimal in the expenditure + + + align:start position:0% +x-star is optimal in the expenditure +minimization problem when the required + + align:start position:0% +minimization problem when the required + + + align:start position:0% +minimization problem when the required +utility level is the utility you + + align:start position:0% +utility level is the utility you + + + align:start position:0% +utility level is the utility you +achieved under the utility maximization + + align:start position:0% +achieved under the utility maximization + + + align:start position:0% +achieved under the utility maximization +problem + + align:start position:0% +problem + + + align:start position:0% +problem +i showed you a picture of that just a + + align:start position:0% +i showed you a picture of that just a + + + align:start position:0% +i showed you a picture of that just a +minute ago + + align:start position:0% +minute ago + + + align:start position:0% +minute ago +and the minimize expenditure when you + + align:start position:0% +and the minimize expenditure when you + + + align:start position:0% +and the minimize expenditure when you +solve the emp + + align:start position:0% +solve the emp + + + align:start position:0% +solve the emp +is exactly the wealth that you had in + + align:start position:0% +is exactly the wealth that you had in + + + align:start position:0% +is exactly the wealth that you had in +the utility maximization problem + + align:start position:0% +the utility maximization problem + + + align:start position:0% +the utility maximization problem +well let me go back + + align:start position:0% +well let me go back + + + align:start position:0% +well let me go back +so i started here + + align:start position:0% +so i started here + + + align:start position:0% +so i started here +we had income i + + align:start position:0% +we had income i + + + align:start position:0% +we had income i +prices were given + + align:start position:0% +prices were given + + + align:start position:0% +prices were given +we maximized utility ended up at u2 + + align:start position:0% +we maximized utility ended up at u2 + + + align:start position:0% +we maximized utility ended up at u2 +given i and p + + align:start position:0% +given i and p + + + align:start position:0% +given i and p +we had a certain + + align:start position:0% +we had a certain + + + align:start position:0% +we had a certain +optimizing solution + + align:start position:0% +optimizing solution + + + align:start position:0% +optimizing solution +here called + + align:start position:0% +here called + + + align:start position:0% +here called +x2 y2 that solves the utility + + align:start position:0% +x2 y2 that solves the utility + + + align:start position:0% +x2 y2 that solves the utility +maximization problem + + align:start position:0% +maximization problem + + + align:start position:0% +maximization problem +and then i said what if + + align:start position:0% +and then i said what if + + + align:start position:0% +and then i said what if +we fix the utility level instead + + align:start position:0% +we fix the utility level instead + + + align:start position:0% +we fix the utility level instead +and solve the expenditure minimization + + align:start position:0% +and solve the expenditure minimization + + + align:start position:0% +and solve the expenditure minimization +problem which is finding the expenditure + + align:start position:0% +problem which is finding the expenditure + + + align:start position:0% +problem which is finding the expenditure +level earmarked by these budget lines + + align:start position:0% +level earmarked by these budget lines + + + align:start position:0% +level earmarked by these budget lines +which is minimal + + align:start position:0% +which is minimal + + + align:start position:0% +which is minimal +and yet allows us to achieve the utility + + align:start position:0% +and yet allows us to achieve the utility + + + align:start position:0% +and yet allows us to achieve the utility +level u2 + + align:start position:0% +level u2 + + + align:start position:0% +level u2 +so this budget line which was a budget + + align:start position:0% +so this budget line which was a budget + + + align:start position:0% +so this budget line which was a budget +line for the utility maximization + + align:start position:0% +line for the utility maximization + + + align:start position:0% +line for the utility maximization +problem + + align:start position:0% +problem + + + align:start position:0% +problem +is kind of the minute minimized + + align:start position:0% +is kind of the minute minimized + + + align:start position:0% +is kind of the minute minimized +expenditure line + + align:start position:0% +expenditure line + + + align:start position:0% +expenditure line +for the expenditure minimization problem + + align:start position:0% +for the expenditure minimization problem + + + align:start position:0% +for the expenditure minimization problem +i don't maybe the picture is just easier + + align:start position:0% +i don't maybe the picture is just easier + + + align:start position:0% +i don't maybe the picture is just easier +but the notation says that + + align:start position:0% +but the notation says that + + + align:start position:0% +but the notation says that +and actually goes the other way + + align:start position:0% +and actually goes the other way + + + align:start position:0% +and actually goes the other way +if x star were solving the expenditure + + align:start position:0% +if x star were solving the expenditure + + + align:start position:0% +if x star were solving the expenditure +minimization problem + + align:start position:0% +minimization problem + + + align:start position:0% +minimization problem +when the acquired utility level is + + align:start position:0% +when the acquired utility level is + + + align:start position:0% +when the acquired utility level is +parameter u + + align:start position:0% +parameter u + + + align:start position:0% +parameter u +then x star is also optimal the same x + + align:start position:0% +then x star is also optimal the same x + + + align:start position:0% +then x star is also optimal the same x +in the utility maximization problem + + align:start position:0% +in the utility maximization problem + + + align:start position:0% +in the utility maximization problem +where we give the guys wealth equal to + + align:start position:0% +where we give the guys wealth equal to + + + align:start position:0% +where we give the guys wealth equal to +the minimized expenditure + + align:start position:0% +the minimized expenditure + + + align:start position:0% +the minimized expenditure +and when they + + align:start position:0% +and when they + + + align:start position:0% +and when they +solve the utility maximization problem + + align:start position:0% +solve the utility maximization problem + + + align:start position:0% +solve the utility maximization problem +at that level of wealth + + align:start position:0% +at that level of wealth + + + align:start position:0% +at that level of wealth +they end up exactly with the u that we + + align:start position:0% +they end up exactly with the u that we + + + align:start position:0% +they end up exactly with the u that we +started with in the expenditure + + align:start position:0% +started with in the expenditure + + + align:start position:0% +started with in the expenditure +minimization problem + + align:start position:0% + + + + align:start position:0% + +relatedly + + align:start position:0% +relatedly + + + align:start position:0% +relatedly +and this is the most compact notation of + + align:start position:0% +and this is the most compact notation of + + + align:start position:0% +and this is the most compact notation of +all + + align:start position:0% +all + + + align:start position:0% +all +that's kind of cool + + align:start position:0% +that's kind of cool + + + align:start position:0% +that's kind of cool +another way to state the proposition is + + align:start position:0% +another way to state the proposition is + + + align:start position:0% +another way to state the proposition is +to say that + + align:start position:0% +to say that + + + align:start position:0% +to say that +given equation 3 when we start given a + + align:start position:0% +given equation 3 when we start given a + + + align:start position:0% +given equation 3 when we start given a +price vector p + + align:start position:0% +price vector p + + + align:start position:0% +price vector p +we are fixing prices p + + align:start position:0% +we are fixing prices p + + + align:start position:0% +we are fixing prices p +we give the guy income or wealth w + + align:start position:0% +we give the guy income or wealth w + + + align:start position:0% +we give the guy income or wealth w +we solve the utility maximization + + align:start position:0% +we solve the utility maximization + + + align:start position:0% +we solve the utility maximization +problem we substitute the maximizing + + align:start position:0% +problem we substitute the maximizing + + + align:start position:0% +problem we substitute the maximizing +demands into utility + + align:start position:0% +demands into utility + + + align:start position:0% +demands into utility +we get the indirect utility function now + + align:start position:0% +we get the indirect utility function now + + + align:start position:0% +we get the indirect utility function now +starting with that level of utility we + + align:start position:0% +starting with that level of utility we + + + align:start position:0% +starting with that level of utility we +do the expenditure minimization problem + + align:start position:0% +do the expenditure minimization problem + + + align:start position:0% +do the expenditure minimization problem +and the minimized expenditures at that p + + align:start position:0% +and the minimized expenditures at that p + + + align:start position:0% +and the minimized expenditures at that p +and particular utility level is w all + + align:start position:0% +and particular utility level is w all + + + align:start position:0% +and particular utility level is w all +over again so it's like feeding back to + + align:start position:0% +over again so it's like feeding back to + + + align:start position:0% +over again so it's like feeding back to +itself + + align:start position:0% + + + + align:start position:0% + +likewise here + + align:start position:0% +likewise here + + + align:start position:0% +likewise here +we start with the parametrized level of + + align:start position:0% +we start with the parametrized level of + + + align:start position:0% +we start with the parametrized level of +u in the expenditure minimization + + align:start position:0% +u in the expenditure minimization + + + align:start position:0% +u in the expenditure minimization +problem taking in p vector p is given + + align:start position:0% +problem taking in p vector p is given + + + align:start position:0% +problem taking in p vector p is given +at that level u + + align:start position:0% +at that level u + + + align:start position:0% +at that level u +we solve for the minimized expenditure + + align:start position:0% +we solve for the minimized expenditure + + + align:start position:0% +we solve for the minimized expenditure +which we called e of p and u + + align:start position:0% +which we called e of p and u + + + align:start position:0% +which we called e of p and u +and if we take that minimized + + align:start position:0% +and if we take that minimized + + + align:start position:0% +and if we take that minimized +expenditure and substituted it as a + + align:start position:0% +expenditure and substituted it as a + + + align:start position:0% +expenditure and substituted it as a +wealth term and solve the utility + + align:start position:0% +wealth term and solve the utility + + + align:start position:0% +wealth term and solve the utility +maximization problem at that wealth we + + align:start position:0% +maximization problem at that wealth we + + + align:start position:0% +maximization problem at that wealth we +would get that the indirect utility + + align:start position:0% +would get that the indirect utility + + + align:start position:0% +would get that the indirect utility +is exactly the u that we started with + + align:start position:0% +is exactly the u that we started with + + + align:start position:0% +is exactly the u that we started with +so it it it is a bit of a mouthful the + + align:start position:0% +so it it it is a bit of a mouthful the + + + align:start position:0% +so it it it is a bit of a mouthful the +notation is quite compact and you may + + align:start position:0% +notation is quite compact and you may + + + align:start position:0% +notation is quite compact and you may +just sort of like have a whiteout moment + + align:start position:0% +just sort of like have a whiteout moment + + + align:start position:0% +just sort of like have a whiteout moment +when you see it but it is repeating in + + align:start position:0% +when you see it but it is repeating in + + + align:start position:0% +when you see it but it is repeating in +different ways in related notation + + align:start position:0% +different ways in related notation + + + align:start position:0% +different ways in related notation +oh this also means that e and v are + + align:start position:0% +oh this also means that e and v are + + + align:start position:0% +oh this also means that e and v are +inverses of one another in the sense + + align:start position:0% +inverses of one another in the sense + + + align:start position:0% +inverses of one another in the sense +that take e and multiply by some + + align:start position:0% +that take e and multiply by some + + + align:start position:0% +that take e and multiply by some +imagined e inverse and you'd get rid of + + align:start position:0% +imagined e inverse and you'd get rid of + + + align:start position:0% +imagined e inverse and you'd get rid of +e on the left hand side and have an e + + align:start position:0% +e on the left hand side and have an e + + + align:start position:0% +e on the left hand side and have an e +inverse on the right hand side so you'd + + align:start position:0% +inverse on the right hand side so you'd + + + align:start position:0% +inverse on the right hand side so you'd +have the value function is an inverse of + + align:start position:0% +have the value function is an inverse of + + + align:start position:0% +have the value function is an inverse of +v + + align:start position:0% +v + + + align:start position:0% +v +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +i said that wrong actually + + align:start position:0% +i said that wrong actually + + + align:start position:0% +i said that wrong actually +if if you take e + + align:start position:0% +if if you take e + + + align:start position:0% +if if you take e +and get rid of it by taking e inverse + + align:start position:0% +and get rid of it by taking e inverse + + + align:start position:0% +and get rid of it by taking e inverse +when you take the inverse of the + + align:start position:0% +when you take the inverse of the + + + align:start position:0% +when you take the inverse of the +expenditure function you end up with a + + align:start position:0% +expenditure function you end up with a + + + align:start position:0% +expenditure function you end up with a +value function + + align:start position:0% +value function + + + align:start position:0% +value function +and likewise when you take the inverse + + align:start position:0% +and likewise when you take the inverse + + + align:start position:0% +and likewise when you take the inverse +of the value function + + align:start position:0% +of the value function + + + align:start position:0% +of the value function +you'll end up with the expenditure + + align:start position:0% +you'll end up with the expenditure + + + align:start position:0% +you'll end up with the expenditure +function + + align:start position:0% +function + + + align:start position:0% +function +okay i said it right that time + + align:start position:0% +okay i said it right that time + + + align:start position:0% +okay i said it right that time +there's a question + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% +uh + + + align:start position:0% +uh +you keep saying indirect use your + + align:start position:0% +you keep saying indirect use your + + + align:start position:0% +you keep saying indirect use your +functioning function or i guess what do + + align:start position:0% +functioning function or i guess what do + + + align:start position:0% +functioning function or i guess what do +you mean when you say indirect + + align:start position:0% +you mean when you say indirect + + + align:start position:0% +you mean when you say indirect +uh it has a label i mean these looks + + align:start position:0% +uh it has a label i mean these looks + + + align:start position:0% +uh it has a label i mean these looks +like value + + align:start position:0% +like value + + + align:start position:0% +like value +we say value function but it's called + + align:start position:0% +we say value function but it's called + + + align:start position:0% +we say value function but it's called +the indirect utility function in the + + align:start position:0% +the indirect utility function in the + + + align:start position:0% +the indirect utility function in the +literature okay that's the name that we + + align:start position:0% +literature okay that's the name that we + + + align:start position:0% +literature okay that's the name that we +give it + + align:start position:0% +give it + + + align:start position:0% +give it +okay so hicksian demand + + align:start position:0% +okay so hicksian demand + + + align:start position:0% +okay so hicksian demand +is solving the expenditure minimization + + align:start position:0% +is solving the expenditure minimization + + + align:start position:0% +is solving the expenditure minimization +problem + + align:start position:0% +problem + + + align:start position:0% +problem +and we have the hixian demand or demand + + align:start position:0% +and we have the hixian demand or demand + + + align:start position:0% +and we have the hixian demand or demand +correspondence if there's more than one + + align:start position:0% +correspondence if there's more than one + + + align:start position:0% +correspondence if there's more than one +solution + + align:start position:0% +solution + + + align:start position:0% +solution +and then the diagrams there's been a + + align:start position:0% +and then the diagrams there's been a + + + align:start position:0% +and then the diagrams there's been a +unique solution this looks like it's a + + align:start position:0% +unique solution this looks like it's a + + + align:start position:0% +unique solution this looks like it's a +new slide but actually right from the + + align:start position:0% +new slide but actually right from the + + + align:start position:0% +new slide but actually right from the +very beginning where we were talking + + align:start position:0% +very beginning where we were talking + + + align:start position:0% +very beginning where we were talking +about price effects and income effects + + align:start position:0% +about price effects and income effects + + + align:start position:0% +about price effects and income effects +and we defined the price effect as a + + align:start position:0% +and we defined the price effect as a + + + align:start position:0% +and we defined the price effect as a +substitution effect we were moving along + + align:start position:0% +substitution effect we were moving along + + + align:start position:0% +substitution effect we were moving along +a given indifference curve so we're + + align:start position:0% +a given indifference curve so we're + + + align:start position:0% +a given indifference curve so we're +really talking about hixing demands all + + align:start position:0% +really talking about hixing demands all + + + align:start position:0% +really talking about hixing demands all +along and again for the third time we + + align:start position:0% +along and again for the third time we + + + align:start position:0% +along and again for the third time we +have a different way of stating the + + align:start position:0% +have a different way of stating the + + + align:start position:0% +have a different way of stating the +problem that the ordinary demand is + + align:start position:0% +problem that the ordinary demand is + + + align:start position:0% +problem that the ordinary demand is +equal to the hixian demand evaluated at + + align:start position:0% +equal to the hixian demand evaluated at + + + align:start position:0% +equal to the hixian demand evaluated at +a utility level which is the indirect + + align:start position:0% +a utility level which is the indirect + + + align:start position:0% +a utility level which is the indirect +utility of the utility maximization + + align:start position:0% +utility of the utility maximization + + + align:start position:0% +utility of the utility maximization +problem and likewise for the expenditure + + align:start position:0% +problem and likewise for the expenditure + + + align:start position:0% +problem and likewise for the expenditure +minimization problem this is as i've + + align:start position:0% +minimization problem this is as i've + + + align:start position:0% +minimization problem this is as i've +been saying true you know starting at + + align:start position:0% +been saying true you know starting at + + + align:start position:0% +been saying true you know starting at +this point you start looking at it one + + align:start position:0% +this point you start looking at it one + + + align:start position:0% +this point you start looking at it one +way or the other you send end up with + + align:start position:0% +way or the other you send end up with + + + align:start position:0% +way or the other you send end up with +exactly the same point + + align:start position:0% +exactly the same point + + + align:start position:0% +exactly the same point +but if we start actually taking discrete + + align:start position:0% +but if we start actually taking discrete + + + align:start position:0% +but if we start actually taking discrete +changes + + align:start position:0% +changes + + + align:start position:0% +changes +things are a bit different and in fact + + align:start position:0% +things are a bit different and in fact + + + align:start position:0% +things are a bit different and in fact +we were actually doing that at the + + align:start position:0% +we were actually doing that at the + + + align:start position:0% +we were actually doing that at the +beginning right we were talking about + + align:start position:0% +beginning right we were talking about + + + align:start position:0% +beginning right we were talking about +a non-trivial decrease in the price of x + + align:start position:0% + + + + align:start position:0% + +so let's talk about discrete changes and + + align:start position:0% +so let's talk about discrete changes and + + + align:start position:0% +so let's talk about discrete changes and +compensated demand + + align:start position:0% +compensated demand + + + align:start position:0% +compensated demand +we start with p and w we have the + + align:start position:0% +we start with p and w we have the + + + align:start position:0% +we start with p and w we have the +maximized demand x + + align:start position:0% +maximized demand x + + + align:start position:0% +maximized demand x +for that given + + align:start position:0% +for that given + + + align:start position:0% +for that given +w but we change p + + align:start position:0% +w but we change p + + + align:start position:0% +w but we change p +from p to p prime + + align:start position:0% +from p to p prime + + + align:start position:0% +from p to p prime +then w prime + + align:start position:0% +then w prime + + + align:start position:0% +then w prime +would say be the minimized expenditure + + align:start position:0% +would say be the minimized expenditure + + + align:start position:0% +would say be the minimized expenditure +at + + align:start position:0% +at + + + align:start position:0% +at +the level of utility u the initial level + + align:start position:0% +the level of utility u the initial level + + + align:start position:0% +the level of utility u the initial level +of utility + + align:start position:0% +of utility + + + align:start position:0% +of utility +at the baseline + + align:start position:0% +at the baseline + + + align:start position:0% +at the baseline +but with the new different price vector + + align:start position:0% +but with the new different price vector + + + align:start position:0% +but with the new different price vector +p prime + + align:start position:0% +p prime + + + align:start position:0% +p prime +and we call that + + align:start position:0% +and we call that + + + align:start position:0% +and we call that +new wealth as opposed to old wealth call + + align:start position:0% +new wealth as opposed to old wealth call + + + align:start position:0% +new wealth as opposed to old wealth call +it w prime so in words + + align:start position:0% +it w prime so in words + + + align:start position:0% +it w prime so in words +that level of income or wealth w prime + + align:start position:0% +that level of income or wealth w prime + + + align:start position:0% +that level of income or wealth w prime +is the one that under the new price + + align:start position:0% +is the one that under the new price + + + align:start position:0% +is the one that under the new price +vector p prime would minimize the + + align:start position:0% +vector p prime would minimize the + + + align:start position:0% +vector p prime would minimize the +expenses + + align:start position:0% +expenses + + + align:start position:0% +expenses +at p prime of achieving the old utility + + align:start position:0% +at p prime of achieving the old utility + + + align:start position:0% +at p prime of achieving the old utility +level remember when we changed the price + + align:start position:0% +level remember when we changed the price + + + align:start position:0% +level remember when we changed the price +we just rotated along the indifference + + align:start position:0% +we just rotated along the indifference + + + align:start position:0% +we just rotated along the indifference +curve going one way or the other + + align:start position:0% +curve going one way or the other + + + align:start position:0% +curve going one way or the other +that's all this english and all this + + align:start position:0% +that's all this english and all this + + + align:start position:0% +that's all this english and all this +notation means + + align:start position:0% +notation means + + + align:start position:0% +notation means +we're just compensating + + align:start position:0% +we're just compensating + + + align:start position:0% +we're just compensating +the agent for the change in + + align:start position:0% +the agent for the change in + + + align:start position:0% +the agent for the change in +purchasing power + + align:start position:0% +purchasing power + + + align:start position:0% +purchasing power +but of course demand doesn't stay + + align:start position:0% +but of course demand doesn't stay + + + align:start position:0% +but of course demand doesn't stay +constant + + align:start position:0% +constant + + + align:start position:0% +constant +because the new demand x star will be + + align:start position:0% +because the new demand x star will be + + + align:start position:0% +because the new demand x star will be +different as the prices are different + + align:start position:0% +different as the prices are different + + + align:start position:0% +different as the prices are different +and the hixian demand includes the price + + align:start position:0% +and the hixian demand includes the price + + + align:start position:0% +and the hixian demand includes the price +substitution effect is defined by it + + align:start position:0% +substitution effect is defined by it + + + align:start position:0% +substitution effect is defined by it +so the hixian demand at the old utility + + align:start position:0% +so the hixian demand at the old utility + + + align:start position:0% +so the hixian demand at the old utility +level and prices p prime + + align:start position:0% +level and prices p prime + + + align:start position:0% +level and prices p prime +is different from the original baseline + + align:start position:0% +is different from the original baseline + + + align:start position:0% +is different from the original baseline +purchase + + align:start position:0% +purchase + + + align:start position:0% +purchase +anyway if you understood the income and + + align:start position:0% +anyway if you understood the income and + + + align:start position:0% +anyway if you understood the income and +substitution effects at the beginning + + align:start position:0% +substitution effects at the beginning + + + align:start position:0% +substitution effects at the beginning +that's all this slide is saying where we + + align:start position:0% +that's all this slide is saying where we + + + align:start position:0% +that's all this slide is saying where we +have you know non-trivial discrete + + align:start position:0% +have you know non-trivial discrete + + + align:start position:0% +have you know non-trivial discrete +changes in the price here's + + align:start position:0% +changes in the price here's + + + align:start position:0% +changes in the price here's +the picture again + + align:start position:0% +the picture again + + + align:start position:0% +the picture again +but + + align:start position:0% +but + + + align:start position:0% +but +be forewarned + + align:start position:0% +be forewarned + + + align:start position:0% +be forewarned +that that somehow to make it more + + align:start position:0% +that that somehow to make it more + + + align:start position:0% +that that somehow to make it more +interesting we're gonna change the price + + align:start position:0% +interesting we're gonna change the price + + + align:start position:0% +interesting we're gonna change the price +of good two instead of good one + + align:start position:0% +of good two instead of good one + + + align:start position:0% +of good two instead of good one +and + + align:start position:0% +and + + + align:start position:0% +and +we are going to + + align:start position:0% +we are going to + + + align:start position:0% +we are going to +increase the price so the original + + align:start position:0% +increase the price so the original + + + align:start position:0% +increase the price so the original +baseline + + align:start position:0% +baseline + + + align:start position:0% +baseline +budget is from w + + align:start position:0% +budget is from w + + + align:start position:0% +budget is from w +to w over p2 + + align:start position:0% +to w over p2 + + + align:start position:0% +to w over p2 +why just w + + align:start position:0% +why just w + + + align:start position:0% +why just w +well + + align:start position:0% +well + + + align:start position:0% +well +there's an assumption down here + + align:start position:0% +there's an assumption down here + + + align:start position:0% +there's an assumption down here +that we only care about the price ratio + + align:start position:0% +that we only care about the price ratio + + + align:start position:0% +that we only care about the price ratio +so let's denominate everything in units + + align:start position:0% +so let's denominate everything in units + + + align:start position:0% +so let's denominate everything in units +of good + + align:start position:0% +of good + + + align:start position:0% +of good +on the x-axis + + align:start position:0% +on the x-axis + + + align:start position:0% +on the x-axis +p1 the first good equals one + + align:start position:0% +p1 the first good equals one + + + align:start position:0% +p1 the first good equals one +so we don't need to worry anymore about + + align:start position:0% +so we don't need to worry anymore about + + + align:start position:0% +so we don't need to worry anymore about +the price of the first good because + + align:start position:0% +the price of the first good because + + + align:start position:0% +the price of the first good because +it's one and the question is what's the + + align:start position:0% +it's one and the question is what's the + + + align:start position:0% +it's one and the question is what's the +price of the second good relative to + + align:start position:0% +price of the second good relative to + + + align:start position:0% +price of the second good relative to +one this case the price of the second + + align:start position:0% +one this case the price of the second + + + align:start position:0% +one this case the price of the second +good p2 + + align:start position:0% +good p2 + + + align:start position:0% +good p2 +is going up + + align:start position:0% +is going up + + + align:start position:0% +is going up +so + + align:start position:0% +so + + + align:start position:0% +so +you would go from w over p2 attainable + + align:start position:0% +you would go from w over p2 attainable + + + align:start position:0% +you would go from w over p2 attainable +to w over p2 prime attainable + + align:start position:0% +to w over p2 prime attainable + + + align:start position:0% +to w over p2 prime attainable +when you go from a price p2 to p2 prime + + align:start position:0% +when you go from a price p2 to p2 prime + + + align:start position:0% +when you go from a price p2 to p2 prime +this is like the earlier diagram where + + align:start position:0% +this is like the earlier diagram where + + + align:start position:0% +this is like the earlier diagram where +we fixed a point on the y-axis and + + align:start position:0% +we fixed a point on the y-axis and + + + align:start position:0% +we fixed a point on the y-axis and +pivoted + + align:start position:0% +pivoted + + + align:start position:0% +pivoted +on the x-axis but this is the other way + + align:start position:0% +on the x-axis but this is the other way + + + align:start position:0% +on the x-axis but this is the other way +around because we're changing the price + + align:start position:0% +around because we're changing the price + + + align:start position:0% +around because we're changing the price +of good two and not the price of good + + align:start position:0% +of good two and not the price of good + + + align:start position:0% +of good two and not the price of good +one + + align:start position:0% + + + + align:start position:0% + +okay so we start here and we have an + + align:start position:0% +okay so we start here and we have an + + + align:start position:0% +okay so we start here and we have an +income a lower budget line + + align:start position:0% +income a lower budget line + + + align:start position:0% +income a lower budget line +now we want to break that into two + + align:start position:0% +now we want to break that into two + + + align:start position:0% +now we want to break that into two +pieces namely the substitution effect + + align:start position:0% +pieces namely the substitution effect + + + align:start position:0% +pieces namely the substitution effect +and the income effect + + align:start position:0% +and the income effect + + + align:start position:0% +and the income effect +what is the substitution effect + + align:start position:0% +what is the substitution effect + + + align:start position:0% +what is the substitution effect +at this higher price of p2 + + align:start position:0% +at this higher price of p2 + + + align:start position:0% +at this higher price of p2 +it's p1 over p2 if you remember the + + align:start position:0% +it's p1 over p2 if you remember the + + + align:start position:0% +it's p1 over p2 if you remember the +slope + + align:start position:0% +slope + + + align:start position:0% +slope +so as p2 goes up that slope goes down + + align:start position:0% +so as p2 goes up that slope goes down + + + align:start position:0% +so as p2 goes up that slope goes down +so we're going to rotate along this + + align:start position:0% +so we're going to rotate along this + + + align:start position:0% +so we're going to rotate along this +indifference curve + + align:start position:0% +indifference curve + + + align:start position:0% +indifference curve +and effectively maximize utility + + align:start position:0% +and effectively maximize utility + + + align:start position:0% +and effectively maximize utility +which is giving you this point what's + + align:start position:0% +which is giving you this point what's + + + align:start position:0% +which is giving you this point what's +the maximal utility you can get + + align:start position:0% +the maximal utility you can get + + + align:start position:0% +the maximal utility you can get +or the minimize expenditure rotating + + align:start position:0% +or the minimize expenditure rotating + + + align:start position:0% +or the minimize expenditure rotating +along this indifference curve and then + + align:start position:0% +along this indifference curve and then + + + align:start position:0% +along this indifference curve and then +the income effect is moving from here a + + align:start position:0% +the income effect is moving from here a + + + align:start position:0% +the income effect is moving from here a +parallel shift back to here + + align:start position:0% +parallel shift back to here + + + align:start position:0% +parallel shift back to here +so + + align:start position:0% +so + + + align:start position:0% +so +our initial level of wealth w was on + + align:start position:0% +our initial level of wealth w was on + + + align:start position:0% +our initial level of wealth w was on +this good one axis and our new level of + + align:start position:0% +this good one axis and our new level of + + + align:start position:0% +this good one axis and our new level of +wealth + + align:start position:0% +wealth + + + align:start position:0% +wealth +is this minimized expenditure at the new + + align:start position:0% +is this minimized expenditure at the new + + + align:start position:0% +is this minimized expenditure at the new +prices p prime given utility level u so + + align:start position:0% +prices p prime given utility level u so + + + align:start position:0% +prices p prime given utility level u so +we've gone from w to w prime + + align:start position:0% +we've gone from w to w prime + + + align:start position:0% +we've gone from w to w prime +that's the change in wealth + + align:start position:0% +that's the change in wealth + + + align:start position:0% +that's the change in wealth +in terms of good one + + align:start position:0% +in terms of good one + + + align:start position:0% +in terms of good one +initial wealth new wealth in terms of + + align:start position:0% +initial wealth new wealth in terms of + + + align:start position:0% +initial wealth new wealth in terms of +good one this must therefore be + + align:start position:0% +good one this must therefore be + + + align:start position:0% +good one this must therefore be +the change in wealth and that's the + + align:start position:0% +the change in wealth and that's the + + + align:start position:0% +the change in wealth and that's the +change in wealth which is positive + + align:start position:0% +change in wealth which is positive + + + align:start position:0% +change in wealth which is positive +which you may have been wondering about + + align:start position:0% +which you may have been wondering about + + + align:start position:0% +which you may have been wondering about +which is necessary to compensate the + + align:start position:0% +which is necessary to compensate the + + + align:start position:0% +which is necessary to compensate the +agent for the fact that the price of + + align:start position:0% +agent for the fact that the price of + + + align:start position:0% +agent for the fact that the price of +good two has gone up + + align:start position:0% +good two has gone up + + + align:start position:0% +good two has gone up +we have to compensate the agent for the + + align:start position:0% +we have to compensate the agent for the + + + align:start position:0% +we have to compensate the agent for the +adverse price change by giving him or + + align:start position:0% +adverse price change by giving him or + + + align:start position:0% +adverse price change by giving him or +her more income + + align:start position:0% +her more income + + + align:start position:0% +her more income +and this is that level of income + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +as i keep saying but it's probably been + + align:start position:0% +as i keep saying but it's probably been + + + align:start position:0% +as i keep saying but it's probably been +more or less an abstract statement i'm + + align:start position:0% +more or less an abstract statement i'm + + + align:start position:0% +more or less an abstract statement i'm +really interested in economies + + align:start position:0% +really interested in economies + + + align:start position:0% +really interested in economies +real economies where we have something + + align:start position:0% +real economies where we have something + + + align:start position:0% +real economies where we have something +going on over time + + align:start position:0% +going on over time + + + align:start position:0% +going on over time +or something with a geography or + + align:start position:0% +or something with a geography or + + + align:start position:0% +or something with a geography or +something + + align:start position:0% +something + + + align:start position:0% +something +having to do with uncertainty and + + align:start position:0% +having to do with uncertainty and + + + align:start position:0% +having to do with uncertainty and +gambles and states of the world + + align:start position:0% +gambles and states of the world + + + align:start position:0% +gambles and states of the world +so + + align:start position:0% +so + + + align:start position:0% +so +having memorized or shown you all those + + align:start position:0% +having memorized or shown you all those + + + align:start position:0% +having memorized or shown you all those +figures with some very interesting + + align:start position:0% +figures with some very interesting + + + align:start position:0% +figures with some very interesting +concepts and a little bit of data along + + align:start position:0% +concepts and a little bit of data along + + + align:start position:0% +concepts and a little bit of data along +the way + + align:start position:0% +the way + + + align:start position:0% +the way +one may nevertheless walk away with the + + align:start position:0% +one may nevertheless walk away with the + + + align:start position:0% +one may nevertheless walk away with the +impression that we're talking about a + + align:start position:0% +impression that we're talking about a + + + align:start position:0% +impression that we're talking about a +static world where we have rice and + + align:start position:0% +static world where we have rice and + + + align:start position:0% +static world where we have rice and +other goods or potatoes and other goods + + align:start position:0% +other goods or potatoes and other goods + + + align:start position:0% +other goods or potatoes and other goods +and + + align:start position:0% +and + + + align:start position:0% +and +we're just comparing wheat to apples as + + align:start position:0% +we're just comparing wheat to apples as + + + align:start position:0% +we're just comparing wheat to apples as +we change prices but no the framework + + align:start position:0% +we change prices but no the framework + + + align:start position:0% +we change prices but no the framework +applies to any goods + + align:start position:0% +applies to any goods + + + align:start position:0% +applies to any goods +in including goods that are earmarked by + + align:start position:0% +in including goods that are earmarked by + + + align:start position:0% +in including goods that are earmarked by +time so + + align:start position:0% +time so + + + align:start position:0% +time so +suppose we have + + align:start position:0% +suppose we have + + + align:start position:0% +suppose we have +two time periods only + + align:start position:0% +two time periods only + + + align:start position:0% +two time periods only +and we'll call consumption c1 + + align:start position:0% +and we'll call consumption c1 + + + align:start position:0% +and we'll call consumption c1 +consumption in date one and c2 + + align:start position:0% +consumption in date one and c2 + + + align:start position:0% +consumption in date one and c2 +consumption in day two and we're gonna + + align:start position:0% +consumption in day two and we're gonna + + + align:start position:0% +consumption in day two and we're gonna +give + + align:start position:0% +give + + + align:start position:0% +give +income as an endowment + + align:start position:0% +income as an endowment + + + align:start position:0% +income as an endowment +meaning + + align:start position:0% +meaning + + + align:start position:0% +meaning +how much income they have + + align:start position:0% +how much income they have + + + align:start position:0% +how much income they have +in the first date one and how much + + align:start position:0% +in the first date one and how much + + + align:start position:0% +in the first date one and how much +income they have in the second date too + + align:start position:0% +income they have in the second date too + + + align:start position:0% +income they have in the second date too +yeah using income is a bit tricky here + + align:start position:0% +yeah using income is a bit tricky here + + + align:start position:0% +yeah using income is a bit tricky here +because we used that before in in the + + align:start position:0% +because we used that before in in the + + + align:start position:0% +because we used that before in in the +static optimization problem so think of + + align:start position:0% +static optimization problem so think of + + + align:start position:0% +static optimization problem so think of +it as money then + + align:start position:0% +it as money then + + + align:start position:0% +it as money then +money + + align:start position:0% +money + + + align:start position:0% +money +in date one money at day two now what is + + align:start position:0% +in date one money at day two now what is + + + align:start position:0% +in date one money at day two now what is +the budget line well + + align:start position:0% +the budget line well + + + align:start position:0% +the budget line well +if they just + + align:start position:0% +if they just + + + align:start position:0% +if they just +eat their money + + align:start position:0% +eat their money + + + align:start position:0% +eat their money +they would have consumption equal to m1 + + align:start position:0% +they would have consumption equal to m1 + + + align:start position:0% +they would have consumption equal to m1 +and m2 + + align:start position:0% +and m2 + + + align:start position:0% +and m2 +but the way this is drawn they don't + + align:start position:0% +but the way this is drawn they don't + + + align:start position:0% +but the way this is drawn they don't +want to do that they want to move in one + + align:start position:0% +want to do that they want to move in one + + + align:start position:0% +want to do that they want to move in one +direction or another + + align:start position:0% +direction or another + + + align:start position:0% +direction or another +so what is this budget line this budget + + align:start position:0% +so what is this budget line this budget + + + align:start position:0% +so what is this budget line this budget +line reflects the possibility of giving + + align:start position:0% +line reflects the possibility of giving + + + align:start position:0% +line reflects the possibility of giving +up money tomorrow and getting more + + align:start position:0% +up money tomorrow and getting more + + + align:start position:0% +up money tomorrow and getting more +consumption today + + align:start position:0% +consumption today + + + align:start position:0% +consumption today +that's borrowing or giving up money + + align:start position:0% +that's borrowing or giving up money + + + align:start position:0% +that's borrowing or giving up money +today and getting more consumption + + align:start position:0% +today and getting more consumption + + + align:start position:0% +today and getting more consumption +tomorrow that's lending so the slope of + + align:start position:0% +tomorrow that's lending so the slope of + + + align:start position:0% +tomorrow that's lending so the slope of +this heavy blue line represents the + + align:start position:0% +this heavy blue line represents the + + + align:start position:0% +this heavy blue line represents the +trade-off of the price of goods today + + align:start position:0% +trade-off of the price of goods today + + + align:start position:0% +trade-off of the price of goods today +for the price of goods tomorrow which + + align:start position:0% +for the price of goods tomorrow which + + + align:start position:0% +for the price of goods tomorrow which +you kind of knew all along but probably + + align:start position:0% +you kind of knew all along but probably + + + align:start position:0% +you kind of knew all along but probably +forgot + + align:start position:0% +forgot + + + align:start position:0% +forgot +why because the slope of the budget line + + align:start position:0% +why because the slope of the budget line + + + align:start position:0% +why because the slope of the budget line +is p1 over p2 p1 being consumption at + + align:start position:0% +is p1 over p2 p1 being consumption at + + + align:start position:0% +is p1 over p2 p1 being consumption at +day one + + align:start position:0% +day one + + + align:start position:0% +day one +p2 being sorry the price of consumption + + align:start position:0% +p2 being sorry the price of consumption + + + align:start position:0% +p2 being sorry the price of consumption +at day two but the economics of the + + align:start position:0% +at day two but the economics of the + + + align:start position:0% +at day two but the economics of the +problem you know doesn't write p1 over + + align:start position:0% +problem you know doesn't write p1 over + + + align:start position:0% +problem you know doesn't write p1 over +p2 it writes r as an interest rate + + align:start position:0% +p2 it writes r as an interest rate + + + align:start position:0% +p2 it writes r as an interest rate +why is it the interest rate because if + + align:start position:0% +why is it the interest rate because if + + + align:start position:0% +why is it the interest rate because if +you gave up some of your money today and + + align:start position:0% +you gave up some of your money today and + + + align:start position:0% +you gave up some of your money today and +put it in the bank + + align:start position:0% +put it in the bank + + + align:start position:0% +put it in the bank +you would get the principal and interest + + align:start position:0% +you would get the principal and interest + + + align:start position:0% +you would get the principal and interest +back tomorrow + + align:start position:0% +back tomorrow + + + align:start position:0% +back tomorrow +so one plus r which is also the slope of + + align:start position:0% +so one plus r which is also the slope of + + + align:start position:0% +so one plus r which is also the slope of +this line + + align:start position:0% +this line + + + align:start position:0% +this line +reflects the trade-off between + + align:start position:0% +reflects the trade-off between + + + align:start position:0% +reflects the trade-off between +consumption today + + align:start position:0% +consumption today + + + align:start position:0% +consumption today +and consumption tomorrow as made + + align:start position:0% +and consumption tomorrow as made + + + align:start position:0% +and consumption tomorrow as made +possible by this interest rate + + align:start position:0% +possible by this interest rate + + + align:start position:0% +possible by this interest rate +okay so then as per the entire lecture + + align:start position:0% +okay so then as per the entire lecture + + + align:start position:0% +okay so then as per the entire lecture +we try to change a price or here let's + + align:start position:0% +we try to change a price or here let's + + + align:start position:0% +we try to change a price or here let's +increase the interest rate so it's still + + align:start position:0% +increase the interest rate so it's still + + + align:start position:0% +increase the interest rate so it's still +possible to eat your money in both + + align:start position:0% +possible to eat your money in both + + + align:start position:0% +possible to eat your money in both +periods but now that the interest rate + + align:start position:0% +periods but now that the interest rate + + + align:start position:0% +periods but now that the interest rate +has gone up the budget line is steeper + + align:start position:0% +has gone up the budget line is steeper + + + align:start position:0% +has gone up the budget line is steeper +for a given surrendering of one unit of + + align:start position:0% +for a given surrendering of one unit of + + + align:start position:0% +for a given surrendering of one unit of +consumption today + + align:start position:0% +consumption today + + + align:start position:0% +consumption today +you get a higher one plus r tomorrow + + align:start position:0% +you get a higher one plus r tomorrow + + + align:start position:0% +you get a higher one plus r tomorrow +so this paler blue line crosses through + + align:start position:0% +so this paler blue line crosses through + + + align:start position:0% +so this paler blue line crosses through +the endowment point but it's steeper and + + align:start position:0% +the endowment point but it's steeper and + + + align:start position:0% +the endowment point but it's steeper and +as drawn with these indifference curves + + align:start position:0% +as drawn with these indifference curves + + + align:start position:0% +as drawn with these indifference curves +the household would move from this point + + align:start position:0% +the household would move from this point + + + align:start position:0% +the household would move from this point +to this point + + align:start position:0% +to this point + + + align:start position:0% +to this point +so + + align:start position:0% +so + + + align:start position:0% +so +let's talk about income and substitution + + align:start position:0% +let's talk about income and substitution + + + align:start position:0% +let's talk about income and substitution +effects + + align:start position:0% +effects + + + align:start position:0% +effects +consumption tomorrow at day two goes up + + align:start position:0% +consumption tomorrow at day two goes up + + + align:start position:0% +consumption tomorrow at day two goes up +and up why + + align:start position:0% +and up why + + + align:start position:0% +and up why +to effects and they're both moving in + + align:start position:0% +to effects and they're both moving in + + + align:start position:0% +to effects and they're both moving in +the same direction the increase in the + + align:start position:0% +the same direction the increase in the + + + align:start position:0% +the same direction the increase in the +interest rate effectively means they + + align:start position:0% +interest rate effectively means they + + + align:start position:0% +interest rate effectively means they +have more income they can take their + + align:start position:0% +have more income they can take their + + + align:start position:0% +have more income they can take their +endowment of money tomorrow and it will + + align:start position:0% +endowment of money tomorrow and it will + + + align:start position:0% +endowment of money tomorrow and it will +be worth more so there's an income + + align:start position:0% +be worth more so there's an income + + + align:start position:0% +be worth more so there's an income +effect associated with the price change + + align:start position:0% +effect associated with the price change + + + align:start position:0% +effect associated with the price change +not only that there's a substitution + + align:start position:0% +not only that there's a substitution + + + align:start position:0% +not only that there's a substitution +effect why because as the interest rate + + align:start position:0% +effect why because as the interest rate + + + align:start position:0% +effect why because as the interest rate +goes up the opportunity cost of eating + + align:start position:0% +goes up the opportunity cost of eating + + + align:start position:0% +goes up the opportunity cost of eating +today goes up it's more painful to eat + + align:start position:0% +today goes up it's more painful to eat + + + align:start position:0% +today goes up it's more painful to eat +today because you could get even more + + align:start position:0% +today because you could get even more + + + align:start position:0% +today because you could get even more +tomorrow by putting the money in the + + align:start position:0% +tomorrow by putting the money in the + + + align:start position:0% +tomorrow by putting the money in the +bank at a higher interest rate so the + + align:start position:0% +bank at a higher interest rate so the + + + align:start position:0% +bank at a higher interest rate so the +substitution effect + + align:start position:0% +substitution effect + + + align:start position:0% +substitution effect +moves them with these nice smooth + + align:start position:0% +moves them with these nice smooth + + + align:start position:0% +moves them with these nice smooth +indifference curves away from + + align:start position:0% +indifference curves away from + + + align:start position:0% +indifference curves away from +consumption today toward higher + + align:start position:0% +consumption today toward higher + + + align:start position:0% +consumption today toward higher +consumption tomorrow + + align:start position:0% +consumption tomorrow + + + align:start position:0% +consumption tomorrow +so the income and substitution effects + + align:start position:0% +so the income and substitution effects + + + align:start position:0% +so the income and substitution effects +in this diagram work in the same + + align:start position:0% +in this diagram work in the same + + + align:start position:0% +in this diagram work in the same +direction for good two but it it's not + + align:start position:0% +direction for good two but it it's not + + + align:start position:0% +direction for good two but it it's not +true for good one at date one + + align:start position:0% +true for good one at date one + + + align:start position:0% +true for good one at date one +or at least it could be ambiguous + + align:start position:0% +or at least it could be ambiguous + + + align:start position:0% +or at least it could be ambiguous +why there's an income effect which + + align:start position:0% +why there's an income effect which + + + align:start position:0% +why there's an income effect which +should increase consumption at date one + + align:start position:0% +should increase consumption at date one + + + align:start position:0% +should increase consumption at date one +but there's a price effect which should + + align:start position:0% +but there's a price effect which should + + + align:start position:0% +but there's a price effect which should +decrease consumption at day one + + align:start position:0% +decrease consumption at day one + + + align:start position:0% +decrease consumption at day one +and those can in principle move in + + align:start position:0% +and those can in principle move in + + + align:start position:0% +and those can in principle move in +opposite directions + + align:start position:0% +opposite directions + + + align:start position:0% +opposite directions +in this case date one consumption is + + align:start position:0% +in this case date one consumption is + + + align:start position:0% +in this case date one consumption is +going down + + align:start position:0% +going down + + + align:start position:0% +going down +so the substitution effect is dominating + + align:start position:0% +so the substitution effect is dominating + + + align:start position:0% +so the substitution effect is dominating +the income effect + + align:start position:0% +the income effect + + + align:start position:0% +the income effect +but it didn't have to go that way you + + align:start position:0% +but it didn't have to go that way you + + + align:start position:0% +but it didn't have to go that way you +could have drawn the indifference curves + + align:start position:0% +could have drawn the indifference curves + + + align:start position:0% +could have drawn the indifference curves +and gotten an increase in the + + align:start position:0% +and gotten an increase in the + + + align:start position:0% +and gotten an increase in the +consumption of date of that good okay + + align:start position:0% +consumption of date of that good okay + + + align:start position:0% +consumption of date of that good okay +let's start out with a different but + + align:start position:0% +let's start out with a different but + + + align:start position:0% +let's start out with a different but +related diagram suppose they have money + + align:start position:0% +related diagram suppose they have money + + + align:start position:0% +related diagram suppose they have money +today and tomorrow as endowments and + + align:start position:0% +today and tomorrow as endowments and + + + align:start position:0% +today and tomorrow as endowments and +this guy is actually doing what + + align:start position:0% +this guy is actually doing what + + + align:start position:0% +this guy is actually doing what +originally borrowing getting more + + align:start position:0% +originally borrowing getting more + + + align:start position:0% +originally borrowing getting more +consumption today than the money he or + + align:start position:0% +consumption today than the money he or + + + align:start position:0% +consumption today than the money he or +she has at the expense of paying it back + + align:start position:0% +she has at the expense of paying it back + + + align:start position:0% +she has at the expense of paying it back +with interest tomorrow therefore having + + align:start position:0% +with interest tomorrow therefore having + + + align:start position:0% +with interest tomorrow therefore having +less consumption than the money that he + + align:start position:0% +less consumption than the money that he + + + align:start position:0% +less consumption than the money that he +or she originally had so + + align:start position:0% +or she originally had so + + + align:start position:0% +or she originally had so +we'd end up with this tangency and now + + align:start position:0% +we'd end up with this tangency and now + + + align:start position:0% +we'd end up with this tangency and now +we still increase the interest rate that + + align:start position:0% +we still increase the interest rate that + + + align:start position:0% +we still increase the interest rate that +makes this pale + + align:start position:0% +makes this pale + + + align:start position:0% +makes this pale +blue line steeper + + align:start position:0% +blue line steeper + + + align:start position:0% +blue line steeper +and you can see consumption is moving + + align:start position:0% +and you can see consumption is moving + + + align:start position:0% +and you can see consumption is moving +inwards so actually + + align:start position:0% +inwards so actually + + + align:start position:0% +inwards so actually +consumption of both goods in the diagram + + align:start position:0% +consumption of both goods in the diagram + + + align:start position:0% +consumption of both goods in the diagram +is going down but let's think about + + align:start position:0% +is going down but let's think about + + + align:start position:0% +is going down but let's think about +income and substitution effects because + + align:start position:0% +income and substitution effects because + + + align:start position:0% +income and substitution effects because +they were borrowing originally as + + align:start position:0% +they were borrowing originally as + + + align:start position:0% +they were borrowing originally as +opposed to lending intuitively an + + align:start position:0% +opposed to lending intuitively an + + + align:start position:0% +opposed to lending intuitively an +increase in the interest rate is a bad + + align:start position:0% +increase in the interest rate is a bad + + + align:start position:0% +increase in the interest rate is a bad +situation for them + + align:start position:0% +situation for them + + + align:start position:0% +situation for them +they were borrowing and now the interest + + align:start position:0% +they were borrowing and now the interest + + + align:start position:0% +they were borrowing and now the interest +rate is higher so the income effect is + + align:start position:0% +rate is higher so the income effect is + + + align:start position:0% +rate is higher so the income effect is +negative and that could show up with + + align:start position:0% +negative and that could show up with + + + align:start position:0% +negative and that could show up with +both goods on the other hand the + + align:start position:0% +both goods on the other hand the + + + align:start position:0% +both goods on the other hand the +substitution effect should still push + + align:start position:0% +substitution effect should still push + + + align:start position:0% +substitution effect should still push +them in the direction of higher + + align:start position:0% +them in the direction of higher + + + align:start position:0% +them in the direction of higher +consumption tomorrow that's the + + align:start position:0% +consumption tomorrow that's the + + + align:start position:0% +consumption tomorrow that's the +substitution effect so for one of these + + align:start position:0% +substitution effect so for one of these + + + align:start position:0% +substitution effect so for one of these +goods + + align:start position:0% +goods + + + align:start position:0% +goods +consumption today is unambiguous but + + align:start position:0% +consumption today is unambiguous but + + + align:start position:0% +consumption today is unambiguous but +consumption tomorrow is ambiguous + + align:start position:0% +consumption tomorrow is ambiguous + + + align:start position:0% +consumption tomorrow is ambiguous +despite the way it's drawn because the + + align:start position:0% +despite the way it's drawn because the + + + align:start position:0% +despite the way it's drawn because the +income and substitution effects work in + + align:start position:0% +income and substitution effects work in + + + align:start position:0% +income and substitution effects work in +the opposite direction + + align:start position:0% +the opposite direction + + + align:start position:0% +the opposite direction +so take a look at those there's a lot + + align:start position:0% +so take a look at those there's a lot + + + align:start position:0% +so take a look at those there's a lot +going on in fact that's kind of the + + align:start position:0% +going on in fact that's kind of the + + + align:start position:0% +going on in fact that's kind of the +point that when we move from apple's + + align:start position:0% +point that when we move from apple's + + + align:start position:0% +point that when we move from apple's +wheats and so on with prices and income + + align:start position:0% +wheats and so on with prices and income + + + align:start position:0% +wheats and so on with prices and income +to an applied problem like you know + + align:start position:0% +to an applied problem like you know + + + align:start position:0% +to an applied problem like you know +what's happening in the us with these + + align:start position:0% +what's happening in the us with these + + + align:start position:0% +what's happening in the us with these +lower and lower interest rates well + + align:start position:0% +lower and lower interest rates well + + + align:start position:0% +lower and lower interest rates well +if we looked at consumer behavior + + align:start position:0% +if we looked at consumer behavior + + + align:start position:0% +if we looked at consumer behavior +there's income effects + + align:start position:0% +there's income effects + + + align:start position:0% +there's income effects +there's uh substitution effects it can + + align:start position:0% +there's uh substitution effects it can + + + align:start position:0% +there's uh substitution effects it can +go in different directions and be in + + align:start position:0% +go in different directions and be in + + + align:start position:0% +go in different directions and be in +conflict and that's an important part of + + align:start position:0% +conflict and that's an important part of + + + align:start position:0% +conflict and that's an important part of +understanding the impact on the + + align:start position:0% +understanding the impact on the + + + align:start position:0% +understanding the impact on the +households and the impact on the economy + + align:start position:0% +households and the impact on the economy + + + align:start position:0% +households and the impact on the economy +and and it's actually a lot more work to + + align:start position:0% +and and it's actually a lot more work to + + + align:start position:0% +and and it's actually a lot more work to +go through this slide in the previous + + align:start position:0% +go through this slide in the previous + + + align:start position:0% +go through this slide in the previous +one than you might have imagined even + + align:start position:0% +one than you might have imagined even + + + align:start position:0% +one than you might have imagined even +though + + align:start position:0% +though + + + align:start position:0% +though +say you were totally sure you could + + align:start position:0% +say you were totally sure you could + + + align:start position:0% +say you were totally sure you could +shift these curves around + + align:start position:0% +shift these curves around + + + align:start position:0% +shift these curves around +in whatever way you wanted when you get + + align:start position:0% +in whatever way you wanted when you get + + + align:start position:0% +in whatever way you wanted when you get +to the economic application we kind of + + align:start position:0% +to the economic application we kind of + + + align:start position:0% +to the economic application we kind of +do it all over again with the new + + align:start position:0% +do it all over again with the new + + + align:start position:0% +do it all over again with the new +realistic labels and it and it and + + align:start position:0% +realistic labels and it and it and + + + align:start position:0% +realistic labels and it and it and +brings that tool to life + + align:start position:0% +brings that tool to life + + + align:start position:0% +brings that tool to life +okay well that's the last slide for + + align:start position:0% +okay well that's the last slide for + + + align:start position:0% +okay well that's the last slide for +today that's the uh the end of this + + align:start position:0% +today that's the uh the end of this + + + align:start position:0% +today that's the uh the end of this +lecture all right thank you very much \ No newline at end of file diff --git a/DYfP7BDhvHI.txt b/DYfP7BDhvHI.txt new file mode 100644 index 0000000000000000000000000000000000000000..d4024844d59aa57959a2d2e3817c59febab019f6 --- /dev/null +++ b/DYfP7BDhvHI.txt @@ -0,0 +1,16440 @@ +align:start position:0% + +um so anyway uh today's lecture you know + + align:start position:0% +um so anyway uh today's lecture you know + + + align:start position:0% +um so anyway uh today's lecture you know +I I was doing uh I did Static + + align:start position:0% +I I was doing uh I did Static + + + align:start position:0% +I I was doing uh I did Static +competition last week today sort of my + + align:start position:0% +competition last week today sort of my + + + align:start position:0% +competition last week today sort of my +plan is I'm going to start with empirics + + align:start position:0% +plan is I'm going to start with empirics + + + align:start position:0% +plan is I'm going to start with empirics +of static competition I'm going to fill + + align:start position:0% +of static competition I'm going to fill + + + align:start position:0% +of static competition I'm going to fill +in in the middle some extra theory that + + align:start position:0% +in in the middle some extra theory that + + + align:start position:0% +in in the middle some extra theory that +I didn't have time to do last uh doe + + align:start position:0% +I didn't have time to do last uh doe + + + align:start position:0% +I didn't have time to do last uh doe +last Wednesday and then like the paper + + align:start position:0% +last Wednesday and then like the paper + + + align:start position:0% +last Wednesday and then like the paper +at the end I'm going to do very very + + align:start position:0% +at the end I'm going to do very very + + + align:start position:0% +at the end I'm going to do very very +quickly because I just was reading it + + align:start position:0% +quickly because I just was reading it + + + align:start position:0% +quickly because I just was reading it +over making the notes and I realized + + align:start position:0% +over making the notes and I realized + + + align:start position:0% +over making the notes and I realized +that you know Tobias is going to be + + align:start position:0% +that you know Tobias is going to be + + + align:start position:0% +that you know Tobias is going to be +spending an awful long awful lot of time + + align:start position:0% +spending an awful long awful lot of time + + + align:start position:0% +spending an awful long awful lot of time +next Monday explaining sort of what the + + align:start position:0% +next Monday explaining sort of what the + + + align:start position:0% +next Monday explaining sort of what the +model is about and the estimation of it + + align:start position:0% +model is about and the estimation of it + + + align:start position:0% +model is about and the estimation of it +and I figured that it'd be much better + + align:start position:0% +and I figured that it'd be much better + + + align:start position:0% +and I figured that it'd be much better +to wait until after he's done that and + + align:start position:0% +to wait until after he's done that and + + + align:start position:0% +to wait until after he's done that and +you can just look at my slides on it um + + align:start position:0% +you can just look at my slides on it um + + + align:start position:0% +you can just look at my slides on it um +and I'll just sort of stick with basic + + align:start position:0% +and I'll just sort of stick with basic + + + align:start position:0% +and I'll just sort of stick with basic +comments so anyway I'm going to first + + align:start position:0% +comments so anyway I'm going to first + + + align:start position:0% +comments so anyway I'm going to first +sort of cover you know one of my + + align:start position:0% +sort of cover you know one of my + + + align:start position:0% +sort of cover you know one of my +favorite papers in the course so this is + + align:start position:0% +favorite papers in the course so this is + + + align:start position:0% +favorite papers in the course so this is +uh breast hands paper competition and + + align:start position:0% +uh breast hands paper competition and + + + align:start position:0% +uh breast hands paper competition and +collusion in the American automobile + + align:start position:0% +collusion in the American automobile + + + align:start position:0% +collusion in the American automobile +industry the 1955 price War um you I + + align:start position:0% +industry the 1955 price War um you I + + + align:start position:0% +industry the 1955 price War um you I +should say in some sense it I I it's one + + align:start position:0% +should say in some sense it I I it's one + + + align:start position:0% +should say in some sense it I I it's one +of my favorite papers I took the star + + align:start position:0% +of my favorite papers I took the star + + + align:start position:0% +of my favorite papers I took the star +off it this year because in some ways I + + align:start position:0% +off it this year because in some ways I + + + align:start position:0% +off it this year because in some ways I +think it's as the paper gets more and + + align:start position:0% +think it's as the paper gets more and + + + align:start position:0% +think it's as the paper gets more and +more dated you can appreciate it more by + + align:start position:0% +more dated you can appreciate it more by + + + align:start position:0% +more dated you can appreciate it more by +hearing about what it does than by + + align:start position:0% +hearing about what it does than by + + + align:start position:0% +hearing about what it does than by +actually reading it you know there's + + align:start position:0% +actually reading it you know there's + + + align:start position:0% +actually reading it you know there's +just sort of many things that you read + + align:start position:0% +just sort of many things that you read + + + align:start position:0% +just sort of many things that you read +and you're like wow that sounds like a + + align:start position:0% +and you're like wow that sounds like a + + + align:start position:0% +and you're like wow that sounds like a +40y old way to do something and so I'll + + align:start position:0% +40y old way to do something and so I'll + + + align:start position:0% +40y old way to do something and so I'll +just leave out the 40-year-old parts + + align:start position:0% +just leave out the 40-year-old parts + + + align:start position:0% +just leave out the 40-year-old parts +that were a bit awkward and probably had + + align:start position:0% +that were a bit awkward and probably had + + + align:start position:0% +that were a bit awkward and probably had +hadap some trouble publishing it to + + align:start position:0% +hadap some trouble publishing it to + + + align:start position:0% +hadap some trouble publishing it to +begin with and I'll sort of give you the + + align:start position:0% +begin with and I'll sort of give you the + + + align:start position:0% +begin with and I'll sort of give you the +main ideas so you know this is a paper + + align:start position:0% +main ideas so you know this is a paper + + + align:start position:0% +main ideas so you know this is a paper +on the io economic history boundary um + + align:start position:0% +on the io economic history boundary um + + + align:start position:0% +on the io economic history boundary um +the to applied topic is what caused the + + align:start position:0% +the to applied topic is what caused the + + + align:start position:0% +the to applied topic is what caused the +1955 surge in US Auto Sales uh and it + + align:start position:0% +1955 surge in US Auto Sales uh and it + + + align:start position:0% +1955 surge in US Auto Sales uh and it +has this interesting hypothesis which is + + align:start position:0% +has this interesting hypothesis which is + + + align:start position:0% +has this interesting hypothesis which is +you know that the 1955 surgeon Auto + + align:start position:0% +you know that the 1955 surgeon Auto + + + align:start position:0% +you know that the 1955 surgeon Auto +Sales was due to a breakdown in + + align:start position:0% +Sales was due to a breakdown in + + + align:start position:0% +Sales was due to a breakdown in +collusion that at the time uh there were + + align:start position:0% +collusion that at the time uh there were + + + align:start position:0% +collusion that at the time uh there were +very few foreign cars sold in the United + + align:start position:0% +very few foreign cars sold in the United + + + align:start position:0% +very few foreign cars sold in the United +States there were largely three American + + align:start position:0% +States there were largely three American + + + align:start position:0% +States there were largely three American +autom makers and his hypothesis that the + + align:start position:0% +autom makers and his hypothesis that the + + + align:start position:0% +autom makers and his hypothesis that the +us automakers were colluding to set set + + align:start position:0% +us automakers were colluding to set set + + + align:start position:0% +us automakers were colluding to set set +Monopoly prices and then in 1955 the + + align:start position:0% +Monopoly prices and then in 1955 the + + + align:start position:0% +Monopoly prices and then in 1955 the +collusion broke down prices Dro many + + align:start position:0% +collusion broke down prices Dro many + + + align:start position:0% +collusion broke down prices Dro many +more cars were sold anyway that's and + + align:start position:0% +more cars were sold anyway that's and + + + align:start position:0% +more cars were sold anyway that's and +then the firms got it figured out again + + align:start position:0% +then the firms got it figured out again + + + align:start position:0% +then the firms got it figured out again +in 1956 prices went back up um you know + + align:start position:0% +in 1956 prices went back up um you know + + + align:start position:0% +in 1956 prices went back up um you know +paper besides having this sort of + + align:start position:0% +paper besides having this sort of + + + align:start position:0% +paper besides having this sort of +interesting historical fact it it has + + align:start position:0% +interesting historical fact it it has + + + align:start position:0% +interesting historical fact it it has +been a really influential as a model for + + align:start position:0% +been a really influential as a model for + + + align:start position:0% +been a really influential as a model for +future work in some sense I I see this + + align:start position:0% +future work in some sense I I see this + + + align:start position:0% +future work in some sense I I see this +as the first structural empirical paper + + align:start position:0% +as the first structural empirical paper + + + align:start position:0% +as the first structural empirical paper +in IO and I think that you know what you + + align:start position:0% +in IO and I think that you know what you + + + align:start position:0% +in IO and I think that you know what you +can think of is that the um really sort + + align:start position:0% +can think of is that the um really sort + + + align:start position:0% +can think of is that the um really sort +of you know many future papers have sort + + align:start position:0% +of you know many future papers have sort + + + align:start position:0% +of you know many future papers have sort +of picked up on breast and hand's + + align:start position:0% +of picked up on breast and hand's + + + align:start position:0% +of picked up on breast and hand's +methodology and sort of adopted this as + + align:start position:0% +methodology and sort of adopted this as + + + align:start position:0% +methodology and sort of adopted this as +a different way of doing things so I + + align:start position:0% +a different way of doing things so I + + + align:start position:0% +a different way of doing things so I +will explain what it was that Brean was + + align:start position:0% +will explain what it was that Brean was + + + align:start position:0% +will explain what it was that Brean was +trying to do in this paper um but for + + align:start position:0% +trying to do in this paper um but for + + + align:start position:0% +trying to do in this paper um but for +the first on the applied topic you know + + align:start position:0% +the first on the applied topic you know + + + align:start position:0% +the first on the applied topic you know +here's a you know he starts with this + + align:start position:0% +here's a you know he starts with this + + + align:start position:0% +here's a you know he starts with this +sort of simple table of of car sales by + + align:start position:0% +sort of simple table of of car sales by + + + align:start position:0% +sort of simple table of of car sales by +year in the United States and you get + + align:start position:0% +year in the United States and you get + + + align:start position:0% +year in the United States and you get +this sort of striking finding which you + + align:start position:0% +this sort of striking finding which you + + + align:start position:0% +this sort of striking finding which you +know is in 1954 us automakers produced 5 + + align:start position:0% +know is in 1954 us automakers produced 5 + + + align:start position:0% +know is in 1954 us automakers produced 5 +a half million cars in 1955 they + + align:start position:0% +a half million cars in 1955 they + + + align:start position:0% +a half million cars in 1955 they +produced 7.9 million cars in 1956 they + + align:start position:0% +produced 7.9 million cars in 1956 they + + + align:start position:0% +produced 7.9 million cars in 1956 they +produced 5.8 million cars so those was + + align:start position:0% +produced 5.8 million cars so those was + + + align:start position:0% +produced 5.8 million cars so those was +you know like cars are a big part of the + + align:start position:0% +you know like cars are a big part of the + + + align:start position:0% +you know like cars are a big part of the +economy and this cars being produced + + align:start position:0% +economy and this cars being produced + + + align:start position:0% +economy and this cars being produced +going up by 40% in one year is a really + + align:start position:0% +going up by 40% in one year is a really + + + align:start position:0% +going up by 40% in one year is a really +striking fact um if you look at it sales + + align:start position:0% +striking fact um if you look at it sales + + + align:start position:0% +striking fact um if you look at it sales +in dollars it's still a big jump the + + align:start position:0% +in dollars it's still a big jump the + + + align:start position:0% +in dollars it's still a big jump the +jump in dollars of car sales is not as + + align:start position:0% +jump in dollars of car sales is not as + + + align:start position:0% +jump in dollars of car sales is not as +big as the jump in unit Car Sales uh and + + align:start position:0% +big as the jump in unit Car Sales uh and + + + align:start position:0% +big as the jump in unit Car Sales uh and +part that's because prices were lower + + align:start position:0% +part that's because prices were lower + + + align:start position:0% +part that's because prices were lower +and in part that's because people did + + align:start position:0% +and in part that's because people did + + + align:start position:0% +and in part that's because people did +buy smaller cars um + + align:start position:0% +buy smaller cars um + + + align:start position:0% +buy smaller cars um +and then if you look at what was going + + align:start position:0% +and then if you look at what was going + + + align:start position:0% +and then if you look at what was going +on in the US economy it was sort of a + + align:start position:0% +on in the US economy it was sort of a + + + align:start position:0% +on in the US economy it was sort of a +boom time in the US economy you can see + + align:start position:0% +boom time in the US economy you can see + + + align:start position:0% +boom time in the US economy you can see +non-auto durable goods spending went + + align:start position:0% +non-auto durable goods spending went + + + align:start position:0% +non-auto durable goods spending went +from 14.5 to 16 billion and then + + align:start position:0% +from 14.5 to 16 billion and then + + + align:start position:0% +from 14.5 to 16 billion and then +continued increasing to 17 billion the + + align:start position:0% +continued increasing to 17 billion the + + + align:start position:0% +continued increasing to 17 billion the +next year so it was a good year for the + + align:start position:0% +next year so it was a good year for the + + + align:start position:0% +next year so it was a good year for the +US economy but not a 40% larger increase + + align:start position:0% +US economy but not a 40% larger increase + + + align:start position:0% +US economy but not a 40% larger increase +in car sales boom in the US econom I + + align:start position:0% +in car sales boom in the US econom I + + + align:start position:0% +in car sales boom in the US econom I +mean there really are not 40% boom in + + align:start position:0% +mean there really are not 40% boom in + + + align:start position:0% +mean there really are not 40% boom in +car sales uh General macro uh shocks um + + align:start position:0% +car sales uh General macro uh shocks um + + + align:start position:0% +car sales uh General macro uh shocks um +you can find explanations in the popular + + align:start position:0% +you can find explanations in the popular + + + align:start position:0% +you can find explanations in the popular +press of what caused the 1955 thing as a + + align:start position:0% +press of what caused the 1955 thing as a + + + align:start position:0% +press of what caused the 1955 thing as a +cultural phenomenon you know here's a + + align:start position:0% +cultural phenomenon you know here's a + + + align:start position:0% +cultural phenomenon you know here's a +quote from c talk describing this where + + align:start position:0% +quote from c talk describing this where + + + align:start position:0% +quote from c talk describing this where +they sort of talk about how rock music + + align:start position:0% +they sort of talk about how rock music + + + align:start position:0% +they sort of talk about how rock music +and Drive-In restaurants were becoming a + + align:start position:0% +and Drive-In restaurants were becoming a + + + align:start position:0% +and Drive-In restaurants were becoming a +thing and there were Sleek new designs + + align:start position:0% +thing and there were Sleek new designs + + + align:start position:0% +thing and there were Sleek new designs +for cars and whatever um you apparently + + align:start position:0% +for cars and whatever um you apparently + + + align:start position:0% +for cars and whatever um you apparently +back in the 1950s Paul Samuelson taught + + align:start position:0% +back in the 1950s Paul Samuelson taught + + + align:start position:0% +back in the 1950s Paul Samuelson taught +both uh 121 through you know taught both + + align:start position:0% +both uh 121 through you know taught both + + + align:start position:0% +both uh 121 through you know taught both +in the in the micro sequence 121 through + + align:start position:0% +in the in the micro sequence 121 through + + + align:start position:0% +in the in the micro sequence 121 through +124 and in the chometric sequence uh 381 + + align:start position:0% +124 and in the chometric sequence uh 381 + + + align:start position:0% +124 and in the chometric sequence uh 381 +382 I think the numbers were still the + + align:start position:0% +382 I think the numbers were still the + + + align:start position:0% +382 I think the numbers were still the +same 50 years or 70 years ago that is + + align:start position:0% +same 50 years or 70 years ago that is + + + align:start position:0% +same 50 years or 70 years ago that is +now um uh but you know Paul apparently + + align:start position:0% +now um uh but you know Paul apparently + + + align:start position:0% +now um uh but you know Paul apparently +you know this was pre + + align:start position:0% +you know this was pre + + + align:start position:0% +you know this was pre +14192 but there was a required seconde + + align:start position:0% +14192 but there was a required seconde + + + align:start position:0% +14192 but there was a required seconde +econometrics paper uh and you know Paul + + align:start position:0% +econometrics paper uh and you know Paul + + + align:start position:0% +econometrics paper uh and you know Paul +samelson apparently when teaching the + + align:start position:0% +samelson apparently when teaching the + + + align:start position:0% +samelson apparently when teaching the +second year conom metrics course would + + align:start position:0% +second year conom metrics course would + + + align:start position:0% +second year conom metrics course would +say that he would flunk any paper that + + align:start position:0% +say that he would flunk any paper that + + + align:start position:0% +say that he would flunk any paper that +claimed it was providing an explanation + + align:start position:0% +claimed it was providing an explanation + + + align:start position:0% +claimed it was providing an explanation +for 1955 Auto Sales where by explanation + + align:start position:0% +for 1955 Auto Sales where by explanation + + + align:start position:0% +for 1955 Auto Sales where by explanation +he sort of meant you know you're + + align:start position:0% +he sort of meant you know you're + + + align:start position:0% +he sort of meant you know you're +regressing Auto Sales on a bunch of + + align:start position:0% +regressing Auto Sales on a bunch of + + + align:start position:0% +regressing Auto Sales on a bunch of +right- hand side variabl like the price + + align:start position:0% +right- hand side variabl like the price + + + align:start position:0% +right- hand side variabl like the price +of steel and whatever um okay so what + + align:start position:0% +of steel and whatever um okay so what + + + align:start position:0% +of steel and whatever um okay so what +were cars in 1955 so I got some + + align:start position:0% +were cars in 1955 so I got some + + + align:start position:0% +were cars in 1955 so I got some +illustrations here so um 1955 Mercury + + align:start position:0% +illustrations here so um 1955 Mercury + + + align:start position:0% +illustrations here so um 1955 Mercury +Montclair 1955 Chevy Bair 1955 Ford + + align:start position:0% +Montclair 1955 Chevy Bair 1955 Ford + + + align:start position:0% +Montclair 1955 Chevy Bair 1955 Ford +Thunderbird you know you can see right + + align:start position:0% +Thunderbird you know you can see right + + + align:start position:0% +Thunderbird you know you can see right +the 55 Thunderbird is a very cute car um + + align:start position:0% +the 55 Thunderbird is a very cute car um + + + align:start position:0% +the 55 Thunderbird is a very cute car um +the other cars just look pretty generic + + align:start position:0% +the other cars just look pretty generic + + + align:start position:0% +the other cars just look pretty generic +to me you know here's the for contrast + + align:start position:0% +to me you know here's the for contrast + + + align:start position:0% +to me you know here's the for contrast +here's the 1955 Chevy ba Air versus the + + align:start position:0% +here's the 1955 Chevy ba Air versus the + + + align:start position:0% +here's the 1955 Chevy ba Air versus the +1954 Chevy ba air and you can see that + + align:start position:0% +1954 Chevy ba air and you can see that + + + align:start position:0% +1954 Chevy ba air and you can see that +you know they sort of seem to have taken + + align:start position:0% +you know they sort of seem to have taken + + + align:start position:0% +you know they sort of seem to have taken +away a little bit of this wheel thing + + align:start position:0% +away a little bit of this wheel thing + + + align:start position:0% +away a little bit of this wheel thing +that stuck out here and they smoothed + + align:start position:0% +that stuck out here and they smoothed + + + align:start position:0% +that stuck out here and they smoothed +out the grill instead of these big + + align:start position:0% +out the grill instead of these big + + + align:start position:0% +out the grill instead of these big +things they went to small things you + + align:start position:0% +things they went to small things you + + + align:start position:0% +things they went to small things you +know it it fits with the sleeker car + + align:start position:0% +know it it fits with the sleeker car + + + align:start position:0% +know it it fits with the sleeker car +Theory but it's it doesn't look all that + + align:start position:0% +Theory but it's it doesn't look all that + + + align:start position:0% +Theory but it's it doesn't look all that +different to me um you know perhaps + + align:start position:0% +different to me um you know perhaps + + + align:start position:0% +different to me um you know perhaps +Sunday perhaps today someone could write + + align:start position:0% +Sunday perhaps today someone could write + + + align:start position:0% +Sunday perhaps today someone could write +a machine learning thing judging the + + align:start position:0% +a machine learning thing judging the + + + align:start position:0% +a machine learning thing judging the +sleekness of cars and seeing how much + + align:start position:0% +sleekness of cars and seeing how much + + + align:start position:0% +sleekness of cars and seeing how much +the sleekness of cars increase affects + + align:start position:0% +the sleekness of cars increase affects + + + align:start position:0% +the sleekness of cars increase affects +increase sales or something like that I + + align:start position:0% +increase sales or something like that I + + + align:start position:0% +increase sales or something like that I +don't know + + align:start position:0% +don't know + + + align:start position:0% +don't know +um okay anyway so his hypothesis is that + + align:start position:0% +um okay anyway so his hypothesis is that + + + align:start position:0% +um okay anyway so his hypothesis is that +this was called caused by a breakdown + + align:start position:0% +this was called caused by a breakdown + + + align:start position:0% +this was called caused by a breakdown +and collusion among the big three + + align:start position:0% +and collusion among the big three + + + align:start position:0% +and collusion among the big three +um you know in general if you're writing + + align:start position:0% +um you know in general if you're writing + + + align:start position:0% +um you know in general if you're writing +an you know like there are several types + + align:start position:0% +an you know like there are several types + + + align:start position:0% +an you know like there are several types +of paper empirical papers one can write + + align:start position:0% +of paper empirical papers one can write + + + align:start position:0% +of paper empirical papers one can write +if you're writing a here's a fact I have + + align:start position:0% +if you're writing a here's a fact I have + + + align:start position:0% +if you're writing a here's a fact I have +an explanation for that fact um + + align:start position:0% +an explanation for that fact um + + + align:start position:0% +an explanation for that fact um +generally you know if you or if the fact + + align:start position:0% +generally you know if you or if the fact + + + align:start position:0% +generally you know if you or if the fact +is well known and you're proposing an + + align:start position:0% +is well known and you're proposing an + + + align:start position:0% +is well known and you're proposing an +explanation for it there are a thousand + + align:start position:0% +explanation for it there are a thousand + + + align:start position:0% +explanation for it there are a thousand +explanations for any fact you can come + + align:start position:0% +explanations for any fact you can come + + + align:start position:0% +explanations for any fact you can come +up with so generally the way you try to + + align:start position:0% +up with so generally the way you try to + + + align:start position:0% +up with so generally the way you try to +make the case that your explanation is + + align:start position:0% +make the case that your explanation is + + + align:start position:0% +make the case that your explanation is +correct and convincing is to think of a + + align:start position:0% +correct and convincing is to think of a + + + align:start position:0% +correct and convincing is to think of a +lot of other predictions that go along + + align:start position:0% +lot of other predictions that go along + + + align:start position:0% +lot of other predictions that go along +with your explanation that people + + align:start position:0% +with your explanation that people + + + align:start position:0% +with your explanation that people +haven't talked about yet and then show + + align:start position:0% +haven't talked about yet and then show + + + align:start position:0% +haven't talked about yet and then show +that here's a bunch of other + + align:start position:0% +that here's a bunch of other + + + align:start position:0% +that here's a bunch of other +implications of my theory now I'm going + + align:start position:0% +implications of my theory now I'm going + + + align:start position:0% +implications of my theory now I'm going +to look at the data in more detail and + + align:start position:0% +to look at the data in more detail and + + + align:start position:0% +to look at the data in more detail and +to these other implications in my theory + + align:start position:0% +to these other implications in my theory + + + align:start position:0% +to these other implications in my theory +are true as well okay um and that's what + + align:start position:0% +are true as well okay um and that's what + + + align:start position:0% +are true as well okay um and that's what +breaston Han is trying to do and his + + align:start position:0% +breaston Han is trying to do and his + + + align:start position:0% +breaston Han is trying to do and his +idea is that you know motivated by the + + align:start position:0% +idea is that you know motivated by the + + + align:start position:0% +idea is that you know motivated by the +then recent literature on differentiated + + align:start position:0% +then recent literature on differentiated + + + align:start position:0% +then recent literature on differentiated +product competition was that if there + + align:start position:0% +product competition was that if there + + + align:start position:0% +product competition was that if there +was a shift from from collusion to + + align:start position:0% +was a shift from from collusion to + + + align:start position:0% +was a shift from from collusion to +competition it ought to have a different + + align:start position:0% +competition it ought to have a different + + + align:start position:0% +competition it ought to have a different +effect on different car models in + + align:start position:0% +effect on different car models in + + + align:start position:0% +effect on different car models in +particular car models that were close in + + align:start position:0% +particular car models that were close in + + + align:start position:0% +particular car models that were close in +product space to other car models uh + + align:start position:0% +product space to other car models uh + + + align:start position:0% +product space to other car models uh +would see a much bigger drop in price + + align:start position:0% +would see a much bigger drop in price + + + align:start position:0% +would see a much bigger drop in price +than car models that were very + + align:start position:0% +than car models that were very + + + align:start position:0% +than car models that were very +distinctive so like on my previous slide + + align:start position:0% +distinctive so like on my previous slide + + + align:start position:0% +distinctive so like on my previous slide +um you know you can see the Ford + + align:start position:0% +um you know you can see the Ford + + + align:start position:0% +um you know you can see the Ford +Thunderbird it was an original car it it + + align:start position:0% +Thunderbird it was an original car it it + + + align:start position:0% +Thunderbird it was an original car it it +looks very different from those other + + align:start position:0% +looks very different from those other + + + align:start position:0% +looks very different from those other +cars maybe if you're colluding or in + + align:start position:0% +cars maybe if you're colluding or in + + + align:start position:0% +cars maybe if you're colluding or in +competition it doesn't matter so much + + align:start position:0% +competition it doesn't matter so much + + + align:start position:0% +competition it doesn't matter so much +for the price of the Ford Thunderbird + + align:start position:0% +for the price of the Ford Thunderbird + + + align:start position:0% +for the price of the Ford Thunderbird +you can sort of you still have a lot of + + align:start position:0% +you can sort of you still have a lot of + + + align:start position:0% +you can sort of you still have a lot of +Market power but at least to my mind if + + align:start position:0% +Market power but at least to my mind if + + + align:start position:0% +Market power but at least to my mind if +if you're looking at the Mercury + + align:start position:0% +if you're looking at the Mercury + + + align:start position:0% +if you're looking at the Mercury +Monclair versus the Chevy + + align:start position:0% +Monclair versus the Chevy + + + align:start position:0% +Monclair versus the Chevy +belir you know I would have to spend + + align:start position:0% +belir you know I would have to spend + + + align:start position:0% +belir you know I would have to spend +some time learning to recognize the + + align:start position:0% +some time learning to recognize the + + + align:start position:0% +some time learning to recognize the +difference between those two if you were + + align:start position:0% +difference between those two if you were + + + align:start position:0% +difference between those two if you were +sort of showing the pictures of them and + + align:start position:0% +sort of showing the pictures of them and + + + align:start position:0% +sort of showing the pictures of them and +so you might think if there was berran + + align:start position:0% +so you might think if there was berran + + + align:start position:0% +so you might think if there was berran +competition between Mercury and Chevy + + align:start position:0% +competition between Mercury and Chevy + + + align:start position:0% +competition between Mercury and Chevy +the price of the B and the Montclair uh + + align:start position:0% +the price of the B and the Montclair uh + + + align:start position:0% +the price of the B and the Montclair uh +they could get in very tough competition + + align:start position:0% +they could get in very tough competition + + + align:start position:0% +they could get in very tough competition +and drive uh prices down towards cost + + align:start position:0% +and drive uh prices down towards cost + + + align:start position:0% +and drive uh prices down towards cost +okay um so just you know breast and hand + + align:start position:0% +okay um so just you know breast and hand + + + align:start position:0% +okay um so just you know breast and hand +has these sort of pictures illustrating + + align:start position:0% +has these sort of pictures illustrating + + + align:start position:0% +has these sort of pictures illustrating +this he sort of supposes that you know + + align:start position:0% +this he sort of supposes that you know + + + align:start position:0% +this he sort of supposes that you know +suppose that this was just a pure + + align:start position:0% +suppose that this was just a pure + + + align:start position:0% +suppose that this was just a pure +one-dimensional vertical competition + + align:start position:0% +one-dimensional vertical competition + + + align:start position:0% +one-dimensional vertical competition +model like I described last time so we + + align:start position:0% +model like I described last time so we + + + align:start position:0% +model like I described last time so we +put quality on the x axis uh the solid + + align:start position:0% +put quality on the x axis uh the solid + + + align:start position:0% +put quality on the x axis uh the solid +line is supposed to represent cost and + + align:start position:0% +line is supposed to represent cost and + + + align:start position:0% +line is supposed to represent cost and +then these are the prices of the + + align:start position:0% +then these are the prices of the + + + align:start position:0% +then these are the prices of the +different car models where General + + align:start position:0% +different car models where General + + + align:start position:0% +different car models where General +Motors and Ford are the two firms + + align:start position:0% +Motors and Ford are the two firms + + + align:start position:0% +Motors and Ford are the two firms +producing them and it it is true that + + align:start position:0% +producing them and it it is true that + + + align:start position:0% +producing them and it it is true that +generally General Motors tend to produce + + align:start position:0% +generally General Motors tend to produce + + + align:start position:0% +generally General Motors tend to produce +the bigger cars and Ford tended to + + align:start position:0% +the bigger cars and Ford tended to + + + align:start position:0% +the bigger cars and Ford tended to +produce the smaller cars so GM sort of + + align:start position:0% +produce the smaller cars so GM sort of + + + align:start position:0% +produce the smaller cars so GM sort of +with its Cadillac division had a lot of + + align:start position:0% +with its Cadillac division had a lot of + + + align:start position:0% +with its Cadillac division had a lot of +the upper end of the quality Spectrum + + align:start position:0% +the upper end of the quality Spectrum + + + align:start position:0% +the upper end of the quality Spectrum +more to itself + + align:start position:0% +more to itself + + + align:start position:0% +more to itself +okay and what he says is that you know + + align:start position:0% +okay and what he says is that you know + + + align:start position:0% +okay and what he says is that you know +in this vertical differentiation model + + align:start position:0% +in this vertical differentiation model + + + align:start position:0% +in this vertical differentiation model +if you have models that are relatively + + align:start position:0% +if you have models that are relatively + + + align:start position:0% +if you have models that are relatively +far apart like models 4 and five if you + + align:start position:0% +far apart like models 4 and five if you + + + align:start position:0% +far apart like models 4 and five if you +view these as very different in quality + + align:start position:0% +view these as very different in quality + + + align:start position:0% +view these as very different in quality +space then if you're if these are the + + align:start position:0% +space then if you're if these are the + + + align:start position:0% +space then if you're if these are the +collusive prices and they start + + align:start position:0% +collusive prices and they start + + + align:start position:0% +collusive prices and they start +competing with each other it may be that + + align:start position:0% +competing with each other it may be that + + + align:start position:0% +competing with each other it may be that +prices for four and five don't drop very + + align:start position:0% +prices for four and five don't drop very + + + align:start position:0% +prices for four and five don't drop very +very much because they're still far + + align:start position:0% +very much because they're still far + + + align:start position:0% +very much because they're still far +enough apart that the they you know the + + align:start position:0% +enough apart that the they you know the + + + align:start position:0% +enough apart that the they you know the +marginal consumers are small relative to + + align:start position:0% +marginal consumers are small relative to + + + align:start position:0% +marginal consumers are small relative to +Total demand so you don't do much to try + + align:start position:0% +Total demand so you don't do much to try + + + align:start position:0% +Total demand so you don't do much to try +to attract more marginal + + align:start position:0% +to attract more marginal + + + align:start position:0% +to attract more marginal +consumers um but on the other hand if + + align:start position:0% +consumers um but on the other hand if + + + align:start position:0% +consumers um but on the other hand if +you look at models two and three that + + align:start position:0% +you look at models two and three that + + + align:start position:0% +you look at models two and three that +are very similar um so this could be my + + align:start position:0% +are very similar um so this could be my + + + align:start position:0% +are very similar um so this could be my +Belair and + + align:start position:0% +Belair and + + + align:start position:0% +Belair and +Montclair if they're colluding they may + + align:start position:0% +Montclair if they're colluding they may + + + align:start position:0% +Montclair if they're colluding they may +charge fairly high + + align:start position:0% +charge fairly high + + + align:start position:0% +charge fairly high +prices and then if they start competing + + align:start position:0% +prices and then if they start competing + + + align:start position:0% +prices and then if they start competing +with each other prices may get driven + + align:start position:0% +with each other prices may get driven + + + align:start position:0% +with each other prices may get driven +very low because they're very close in + + align:start position:0% +very low because they're very close in + + + align:start position:0% +very low because they're very close in +product space + + align:start position:0% + + + + align:start position:0% + +and you know so if you had that as an + + align:start position:0% +and you know so if you had that as an + + + align:start position:0% +and you know so if you had that as an +idea and you thought about how you could + + align:start position:0% +idea and you thought about how you could + + + align:start position:0% +idea and you thought about how you could +test that you know breaston hand could + + align:start position:0% +test that you know breaston hand could + + + align:start position:0% +test that you know breaston hand could +have taken this sort of what I'd call + + align:start position:0% +have taken this sort of what I'd call + + + align:start position:0% +have taken this sort of what I'd call +the classic reduced form approach in IO + + align:start position:0% +the classic reduced form approach in IO + + + align:start position:0% +the classic reduced form approach in IO +which is you make predictions you test + + align:start position:0% +which is you make predictions you test + + + align:start position:0% +which is you make predictions you test +the predictions and so what you could + + align:start position:0% +the predictions and so what you could + + + align:start position:0% +the predictions and so what you could +have looked for is you know our price + + align:start position:0% +have looked for is you know our price + + + align:start position:0% +have looked for is you know our price +drops from 1954 to + + align:start position:0% +drops from 1954 to + + + align:start position:0% +drops from 1954 to +1955 larger for car models that are + + align:start position:0% +1955 larger for car models that are + + + align:start position:0% +1955 larger for car models that are +closer in product space and that would + + align:start position:0% +closer in product space and that would + + + align:start position:0% +closer in product space and that would +be sort of an auxil prediction of a + + align:start position:0% +be sort of an auxil prediction of a + + + align:start position:0% +be sort of an auxil prediction of a +breakdown in + + align:start position:0% +breakdown in + + + align:start position:0% +breakdown in +collusion um but you know breast andan + + align:start position:0% +collusion um but you know breast andan + + + align:start position:0% +collusion um but you know breast andan +thought that you know this is really not + + align:start position:0% +thought that you know this is really not + + + align:start position:0% +thought that you know this is really not +all you could do with that theory you + + align:start position:0% +all you could do with that theory you + + + align:start position:0% +all you could do with that theory you +know the one thing is that the theory is + + align:start position:0% +know the one thing is that the theory is + + + align:start position:0% +know the one thing is that the theory is +more complicated than that you know like + + align:start position:0% +more complicated than that you know like + + + align:start position:0% +more complicated than that you know like +if if you remember the sort of vertical + + align:start position:0% +if if you remember the sort of vertical + + + align:start position:0% +if if you remember the sort of vertical +competition model every firm does have a + + align:start position:0% +competition model every firm does have a + + + align:start position:0% +competition model every firm does have a +first order condition that's pinned out + + align:start position:0% +first order condition that's pinned out + + + align:start position:0% +first order condition that's pinned out +to the firm above and to the firm below + + align:start position:0% +to the firm above and to the firm below + + + align:start position:0% +to the firm above and to the firm below +and those two first order conditions are + + align:start position:0% +and those two first order conditions are + + + align:start position:0% +and those two first order conditions are +going to pin down the prices but those + + align:start position:0% +going to pin down the prices but those + + + align:start position:0% +going to pin down the prices but those +things are going to involve the prices + + align:start position:0% +things are going to involve the prices + + + align:start position:0% +things are going to involve the prices +of the low next low lower quality model + + align:start position:0% +of the low next low lower quality model + + + align:start position:0% +of the low next low lower quality model +and the lower model below that and the + + align:start position:0% +and the lower model below that and the + + + align:start position:0% +and the lower model below that and the +model below that and so it is a system + + align:start position:0% +model below that and so it is a system + + + align:start position:0% +model below that and so it is a system +of n equations and N unknowns and any + + align:start position:0% +of n equations and N unknowns and any + + + align:start position:0% +of n equations and N unknowns and any +change in the competition you know like + + align:start position:0% +change in the competition you know like + + + align:start position:0% +change in the competition you know like +the change any in any one place is going + + align:start position:0% +the change any in any one place is going + + + align:start position:0% +the change any in any one place is going +to have Ripple effects throughout the + + align:start position:0% +to have Ripple effects throughout the + + + align:start position:0% +to have Ripple effects throughout the +distribution and will change the prices + + align:start position:0% +distribution and will change the prices + + + align:start position:0% +distribution and will change the prices +of the higher price models even if + + align:start position:0% +of the higher price models even if + + + align:start position:0% +of the higher price models even if +they're not in very close competition um + + align:start position:0% +they're not in very close competition um + + + align:start position:0% +they're not in very close competition um +and then the other thing that Brean said + + align:start position:0% +and then the other thing that Brean said + + + align:start position:0% +and then the other thing that Brean said +is that you know our theories are + + align:start position:0% +is that you know our theories are + + + align:start position:0% +is that you know our theories are +quantitative theories not just + + align:start position:0% +quantitative theories not just + + + align:start position:0% +quantitative theories not just +qualitative theories they don't just + + align:start position:0% +qualitative theories they don't just + + + align:start position:0% +qualitative theories they don't just +predict that prices will go down they + + align:start position:0% +predict that prices will go down they + + + align:start position:0% +predict that prices will go down they +really are predicting how much the + + align:start position:0% +really are predicting how much the + + + align:start position:0% +really are predicting how much the +prices would go down and how much the + + align:start position:0% +prices would go down and how much the + + + align:start position:0% +prices would go down and how much the +prices would go down depend on things + + align:start position:0% +prices would go down depend on things + + + align:start position:0% +prices would go down depend on things +that we in theory could measure uh and + + align:start position:0% +that we in theory could measure uh and + + + align:start position:0% +that we in theory could measure uh and +so really to give a more complete test + + align:start position:0% +so really to give a more complete test + + + align:start position:0% +so really to give a more complete test +of the theory we should really see + + align:start position:0% +of the theory we should really see + + + align:start position:0% +of the theory we should really see +whether the theory can qual can + + align:start position:0% +whether the theory can qual can + + + align:start position:0% +whether the theory can qual can +quantitatively amount account for + + align:start position:0% +quantitatively amount account for + + + align:start position:0% +quantitatively amount account for +everything instead of just qualitatively + + align:start position:0% +everything instead of just qualitatively + + + align:start position:0% +everything instead of just qualitatively +account for everything um so what did + + align:start position:0% +account for everything um so what did + + + align:start position:0% +account for everything um so what did +breast andan do and this is where the + + align:start position:0% +breast andan do and this is where the + + + align:start position:0% +breast andan do and this is where the +paper starts to look awfully primitive + + align:start position:0% +paper starts to look awfully primitive + + + align:start position:0% +paper starts to look awfully primitive +these days um you know he he basically + + align:start position:0% +these days um you know he he basically + + + align:start position:0% +these days um you know he he basically +wrote down the standard vertical + + align:start position:0% +wrote down the standard vertical + + + align:start position:0% +wrote down the standard vertical +differentiation model that I Des cried + + align:start position:0% +differentiation model that I Des cried + + + align:start position:0% +differentiation model that I Des cried +in lecture um so Suppose there are n + + align:start position:0% +in lecture um so Suppose there are n + + + align:start position:0% +in lecture um so Suppose there are n +models with qualities V1 through + + align:start position:0% +models with qualities V1 through + + + align:start position:0% +models with qualities V1 through +VN and suppose that the quality of a car + + align:start position:0% +VN and suppose that the quality of a car + + + align:start position:0% +VN and suppose that the quality of a car +is simply a function of observable + + align:start position:0% +is simply a function of observable + + + align:start position:0% +is simply a function of observable +characteristics uh what function of + + align:start position:0% +characteristics uh what function of + + + align:start position:0% +characteristics uh what function of +observable characteristics you know + + align:start position:0% +observable characteristics you know + + + align:start position:0% +observable characteristics you know +basically it's just x * square root of x + + align:start position:0% +basically it's just x * square root of x + + + align:start position:0% +basically it's just x * square root of x +x beta uh where X would contain things + + align:start position:0% +x beta uh where X would contain things + + + align:start position:0% +x beta uh where X would contain things +like uh the horsepower of the car + + align:start position:0% +like uh the horsepower of the car + + + align:start position:0% +like uh the horsepower of the car +whether it had a V8 engine the size in + + align:start position:0% +whether it had a V8 engine the size in + + + align:start position:0% +whether it had a V8 engine the size in +cubic inches the weight of the car + + align:start position:0% +cubic inches the weight of the car + + + align:start position:0% +cubic inches the weight of the car +whether head air conditioning things + + align:start position:0% +whether head air conditioning things + + + align:start position:0% +whether head air conditioning things +like that um he then assumes that + + align:start position:0% +like that um he then assumes that + + + align:start position:0% +like that um he then assumes that +there's again just like in the vertical + + align:start position:0% +there's again just like in the vertical + + + align:start position:0% +there's again just like in the vertical +differentiation model uh there's a mass + + align:start position:0% +differentiation model uh there's a mass + + + align:start position:0% +differentiation model uh there's a mass +of consumers with types Theta + + align:start position:0% +of consumers with types Theta + + + align:start position:0% +of consumers with types Theta +distributed uniform on some interval 0 + + align:start position:0% +distributed uniform on some interval 0 + + + align:start position:0% +distributed uniform on some interval 0 +to Vmax and there's a density Delta on + + align:start position:0% +to Vmax and there's a density Delta on + + + align:start position:0% +to Vmax and there's a density Delta on +that + + align:start position:0% +that + + + align:start position:0% +that +interval and then he says that the + + align:start position:0% +interval and then he says that the + + + align:start position:0% +interval and then he says that the +utility of a type Theta consumer from + + align:start position:0% +utility of a type Theta consumer from + + + align:start position:0% +utility of a type Theta consumer from +buying model I is going to be Theta VI + + align:start position:0% +buying model I is going to be Theta VI + + + align:start position:0% +buying model I is going to be Theta VI +minus + + align:start position:0% +minus + + + align:start position:0% +minus +Pi so pure vertical model uh and then he + + align:start position:0% +Pi so pure vertical model uh and then he + + + align:start position:0% +Pi so pure vertical model uh and then he +has the cost of producing Q units at + + align:start position:0% +has the cost of producing Q units at + + + align:start position:0% +has the cost of producing Q units at +quality V is uh some constant that's or + + align:start position:0% +quality V is uh some constant that's or + + + align:start position:0% +quality V is uh some constant that's or +some function of v that's going to end + + align:start position:0% +some function of v that's going to end + + + align:start position:0% +some function of v that's going to end +up being irrelevant and then Q mu e to + + align:start position:0% +up being irrelevant and then Q mu e to + + + align:start position:0% +up being irrelevant and then Q mu e to +the V power so you know costs you again + + align:start position:0% +the V power so you know costs you again + + + align:start position:0% +the V power so you know costs you again +you know V somehow is like the square + + align:start position:0% +you know V somehow is like the square + + + align:start position:0% +you know V somehow is like the square +root of the observable variables and + + align:start position:0% +root of the observable variables and + + + align:start position:0% +root of the observable variables and +then costs are exponentially increasing + + align:start position:0% +then costs are exponentially increasing + + + align:start position:0% +then costs are exponentially increasing +in v as you try to raise quality uh and + + align:start position:0% +in v as you try to raise quality uh and + + + align:start position:0% +in v as you try to raise quality uh and +then there there is just it's a constant + + align:start position:0% +then there there is just it's a constant + + + align:start position:0% +then there there is just it's a constant +marginal cost so mu time e to the V is + + align:start position:0% +marginal cost so mu time e to the V is + + + align:start position:0% +marginal cost so mu time e to the V is +the is the marginal cost of producing a + + align:start position:0% +the is the marginal cost of producing a + + + align:start position:0% +the is the marginal cost of producing a +single + + align:start position:0% + + + + align:start position:0% + +car okay but then sort of what you know + + align:start position:0% +car okay but then sort of what you know + + + align:start position:0% +car okay but then sort of what you know +breast hand's thought was is that you + + align:start position:0% +breast hand's thought was is that you + + + align:start position:0% +breast hand's thought was is that you +know this is a model that I can fully + + align:start position:0% +know this is a model that I can fully + + + align:start position:0% +know this is a model that I can fully +specify and if you fully specify the + + align:start position:0% +specify and if you fully specify the + + + align:start position:0% +specify and if you fully specify the +prim you if you fully specify The + + align:start position:0% +prim you if you fully specify The + + + align:start position:0% +prim you if you fully specify The +Primitives which is um you know the + + align:start position:0% +Primitives which is um you know the + + + align:start position:0% +Primitives which is um you know the +production functions of the firms the uh + + align:start position:0% +production functions of the firms the uh + + + align:start position:0% +production functions of the firms the uh +preferences of the consumers and the + + align:start position:0% +preferences of the consumers and the + + + align:start position:0% +preferences of the consumers and the +model of firm + + align:start position:0% +model of firm + + + align:start position:0% +model of firm +Behavior then you can fully predict + + align:start position:0% +Behavior then you can fully predict + + + align:start position:0% +Behavior then you can fully predict +what's going to happen so you sort of + + align:start position:0% +what's going to happen so you sort of + + + align:start position:0% +what's going to happen so you sort of +basically once once you fix the + + align:start position:0% +basically once once you fix the + + + align:start position:0% +basically once once you fix the +parameters beta mu in the production + + align:start position:0% +parameters beta mu in the production + + + align:start position:0% +parameters beta mu in the production +function and Delta in Vmax in the um + + align:start position:0% +function and Delta in Vmax in the um + + + align:start position:0% +function and Delta in Vmax in the um +consumer preferences you can fully + + align:start position:0% +consumer preferences you can fully + + + align:start position:0% +consumer preferences you can fully +predict what's going to happen under any + + align:start position:0% +predict what's going to happen under any + + + align:start position:0% +predict what's going to happen under any +model of behavior and so in particular + + align:start position:0% +model of behavior and so in particular + + + align:start position:0% +model of behavior and so in particular +like you know collusive pricing just + + align:start position:0% +like you know collusive pricing just + + + align:start position:0% +like you know collusive pricing just +becomes the multi-product Monopoly model + + align:start position:0% +becomes the multi-product Monopoly model + + + align:start position:0% +becomes the multi-product Monopoly model +that we covered um static competition + + align:start position:0% +that we covered um static competition + + + align:start position:0% +that we covered um static competition +would be another natural model know + + align:start position:0% +would be another natural model know + + + align:start position:0% +would be another natural model know +would people often apply to a situation + + align:start position:0% +would people often apply to a situation + + + align:start position:0% +would people often apply to a situation +like this um and then breast Nan also + + align:start position:0% +like this um and then breast Nan also + + + align:start position:0% +like this um and then breast Nan also +considers two other models um one of + + align:start position:0% +considers two other models um one of + + + align:start position:0% +considers two other models um one of +these is like + + align:start position:0% +these is like + + + align:start position:0% +these is like +you know non-cooperative static + + align:start position:0% +you know non-cooperative static + + + align:start position:0% +you know non-cooperative static +competition between all products so this + + align:start position:0% +competition between all products so this + + + align:start position:0% +competition between all products so this +is as if every Ford Model is run by a + + align:start position:0% +is as if every Ford Model is run by a + + + align:start position:0% +is as if every Ford Model is run by a +different manager who's competing + + align:start position:0% +different manager who's competing + + + align:start position:0% +different manager who's competing +aggressively against every other Ford + + align:start position:0% +aggressively against every other Ford + + + align:start position:0% +aggressively against every other Ford +product so every product in the model in + + align:start position:0% +product so every product in the model in + + + align:start position:0% +product so every product in the model in +the in the market is run by a different + + align:start position:0% +the in the market is run by a different + + + align:start position:0% +the in the market is run by a different +manager who's not who's profit + + align:start position:0% +manager who's not who's profit + + + align:start position:0% +manager who's not who's profit +maximizing solely based on that car and + + align:start position:0% +maximizing solely based on that car and + + + align:start position:0% +maximizing solely based on that car and +then he's got a fourth one you know this + + align:start position:0% +then he's got a fourth one you know this + + + align:start position:0% +then he's got a fourth one you know this +is one of those ones where it's based on + + align:start position:0% +is one of those ones where it's based on + + + align:start position:0% +is one of those ones where it's based on +somebody's paper from the 1970s and I + + align:start position:0% +somebody's paper from the 1970s and I + + + align:start position:0% +somebody's paper from the 1970s and I +have a hard time it's sort of perfect + + align:start position:0% +have a hard time it's sort of perfect + + + align:start position:0% +have a hard time it's sort of perfect +competition you have a hard time making + + align:start position:0% +competition you have a hard time making + + + align:start position:0% +competition you have a hard time making +out today what is that model and what + + align:start position:0% +out today what is that model and what + + + align:start position:0% +out today what is that model and what +would be the justification for it but + + align:start position:0% +would be the justification for it but + + + align:start position:0% +would be the justification for it but +he's got four different models he notes + + align:start position:0% +he's got four different models he notes + + + align:start position:0% +he's got four different models he notes +that under any of those four models you + + align:start position:0% +that under any of those four models you + + + align:start position:0% +that under any of those four models you +can work out what should happen given + + align:start position:0% +can work out what should happen given + + + align:start position:0% +can work out what should happen given +any set of parameters so then you can + + align:start position:0% +any set of parameters so then you can + + + align:start position:0% +any set of parameters so then you can +invert that relationship and say you + + align:start position:0% +invert that relationship and say you + + + align:start position:0% +invert that relationship and say you +know given any one of these models and + + align:start position:0% +know given any one of these models and + + + align:start position:0% +know given any one of these models and +one of these models applied to any in + + align:start position:0% +one of these models applied to any in + + + align:start position:0% +one of these models applied to any in +for any of any behavioral model in any + + align:start position:0% +for any of any behavioral model in any + + + align:start position:0% +for any of any behavioral model in any +year 1954 55 or 56 I can figure out what + + align:start position:0% +year 1954 55 or 56 I can figure out what + + + align:start position:0% +year 1954 55 or 56 I can figure out what +would be the parameters that best + + align:start position:0% +would be the parameters that best + + + align:start position:0% +would be the parameters that best +explain the data and then breast Nan's + + align:start position:0% +explain the data and then breast Nan's + + + align:start position:0% +explain the data and then breast Nan's +idea was for each model of firm behavior + + align:start position:0% +idea was for each model of firm behavior + + + align:start position:0% +idea was for each model of firm behavior +in each year I figure out what + + align:start position:0% +in each year I figure out what + + + align:start position:0% +in each year I figure out what +parameters best explain the data and + + align:start position:0% +parameters best explain the data and + + + align:start position:0% +parameters best explain the data and +then ask how well does that model + + align:start position:0% +then ask how well does that model + + + align:start position:0% +then ask how well does that model +explain the data with those parameters + + align:start position:0% +explain the data with those parameters + + + align:start position:0% +explain the data with those parameters +and then I pick out whichever model fits + + align:start position:0% +and then I pick out whichever model fits + + + align:start position:0% +and then I pick out whichever model fits +best in every year um to sort of say + + align:start position:0% +best in every year um to sort of say + + + align:start position:0% +best in every year um to sort of say +this is how the firms behaved in that + + align:start position:0% +this is how the firms behaved in that + + + align:start position:0% +this is how the firms behaved in that +year okay um and the way he does this is + + align:start position:0% +year okay um and the way he does this is + + + align:start position:0% +year okay um and the way he does this is +again this seems archaic but it's a set + + align:start position:0% +again this seems archaic but it's a set + + + align:start position:0% +again this seems archaic but it's a set +of non- nested hypotheses hypothesis + + align:start position:0% +of non- nested hypotheses hypothesis + + + align:start position:0% +of non- nested hypotheses hypothesis +tests where he looks at how well the you + + align:start position:0% +tests where he looks at how well the you + + + align:start position:0% +tests where he looks at how well the you +know looks at the model fits the model + + align:start position:0% +know looks at the model fits the model + + + align:start position:0% +know looks at the model fits the model +to the data and then like in a + + align:start position:0% +to the data and then like in a + + + align:start position:0% +to the data and then like in a +likelihood ratio sense says do the + + align:start position:0% +likelihood ratio sense says do the + + + align:start position:0% +likelihood ratio sense says do the +predictions of the other model help + + align:start position:0% +predictions of the other model help + + + align:start position:0% +predictions of the other model help +explain the errors like do the + + align:start position:0% +explain the errors like do the + + + align:start position:0% +explain the errors like do the +predictions of model two help explain + + align:start position:0% +predictions of model two help explain + + + align:start position:0% +predictions of model two help explain +the errors in model one and if + + align:start position:0% +the errors in model one and if + + + align:start position:0% +the errors in model one and if +predictions of model two help explain + + align:start position:0% +predictions of model two help explain + + + align:start position:0% +predictions of model two help explain +the errors of model one then model one + + align:start position:0% +the errors of model one then model one + + + align:start position:0% +the errors of model one then model one +is rejected by model two and model one + + align:start position:0% +is rejected by model two and model one + + + align:start position:0% +is rejected by model two and model one +is not the correct model and so what he + + align:start position:0% +is not the correct model and so what he + + + align:start position:0% +is not the correct model and so what he +looks for is is there one of these four + + align:start position:0% +looks for is is there one of these four + + + align:start position:0% +looks for is is there one of these four +Mo in each year year by year is there + + align:start position:0% +Mo in each year year by year is there + + + align:start position:0% +Mo in each year year by year is there +one of these four models that's not + + align:start position:0% +one of these four models that's not + + + align:start position:0% +one of these four models that's not +rejected by the other + + align:start position:0% +rejected by the other + + + align:start position:0% +rejected by the other +model and then the other thing that + + align:start position:0% +model and then the other thing that + + + align:start position:0% +model and then the other thing that +brehan really also pioneered uh and this + + align:start position:0% +brehan really also pioneered uh and this + + + align:start position:0% +brehan really also pioneered uh and this +was you know paper IND thesis was the + + align:start position:0% +was you know paper IND thesis was the + + + align:start position:0% +was you know paper IND thesis was the +idea of a + + align:start position:0% +idea of a + + + align:start position:0% +idea of a +counterfactual his thought was that you + + align:start position:0% +counterfactual his thought was that you + + + align:start position:0% +counterfactual his thought was that you +know if we do this and we figure out + + align:start position:0% +know if we do this and we figure out + + + align:start position:0% +know if we do this and we figure out +what is the correct model on each year + + align:start position:0% +what is the correct model on each year + + + align:start position:0% +what is the correct model on each year +then I can do a counterfactual and + + align:start position:0% +then I can do a counterfactual and + + + align:start position:0% +then I can do a counterfactual and +predict what would have happened under + + align:start position:0% +predict what would have happened under + + + align:start position:0% +predict what would have happened under +any other model or any other government + + align:start position:0% +any other model or any other government + + + align:start position:0% +any other model or any other government +policy I could tell you what if the + + align:start position:0% +policy I could tell you what if the + + + align:start position:0% +policy I could tell you what if the +government had had a 5% sales tax on + + align:start position:0% +government had had a 5% sales tax on + + + align:start position:0% +government had had a 5% sales tax on +cars what would happen if the firms had + + align:start position:0% +cars what would happen if the firms had + + + align:start position:0% +cars what would happen if the firms had +colluded instead of comp with each other + + align:start position:0% +colluded instead of comp with each other + + + align:start position:0% +colluded instead of comp with each other +what would have happened in you know any + + align:start position:0% +what would have happened in you know any + + + align:start position:0% +what would have happened in you know any +any other thing change you can think of + + align:start position:0% +any other thing change you can think of + + + align:start position:0% +any other thing change you can think of +to the industry you can sort of predict + + align:start position:0% +to the industry you can sort of predict + + + align:start position:0% +to the industry you can sort of predict +what would have happened under his model + + align:start position:0% +what would have happened under his model + + + align:start position:0% +what would have happened under his model +and gives you the sort of counterfactual + + align:start position:0% +and gives you the sort of counterfactual + + + align:start position:0% +and gives you the sort of counterfactual +prediction + + align:start position:0% +prediction + + + align:start position:0% +prediction +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +okay okay so what are the main applied + + align:start position:0% +okay okay so what are the main applied + + + align:start position:0% +okay okay so what are the main applied +results of the paper um and you know I I + + align:start position:0% +results of the paper um and you know I I + + + align:start position:0% +results of the paper um and you know I I +sort of always think that like you know + + align:start position:0% +sort of always think that like you know + + + align:start position:0% +sort of always think that like you know +some maybe someday someone will rewrite + + align:start position:0% +some maybe someday someone will rewrite + + + align:start position:0% +some maybe someday someone will rewrite +this paper you know obviously this is + + align:start position:0% +this paper you know obviously this is + + + align:start position:0% +this paper you know obviously this is +primitive data like minimal data from + + align:start position:0% +primitive data like minimal data from + + + align:start position:0% +primitive data like minimal data from +the 1950s maybe someone will rewrite + + align:start position:0% +the 1950s maybe someone will rewrite + + + align:start position:0% +the 1950s maybe someone will rewrite +this paper and sort of say from more + + align:start position:0% +this paper and sort of say from more + + + align:start position:0% +this paper and sort of say from more +modern perspective what do we think + + align:start position:0% +modern perspective what do we think + + + align:start position:0% +modern perspective what do we think +actually happened but you know what does + + align:start position:0% +actually happened but you know what does + + + align:start position:0% +actually happened but you know what does +this analysis say first one says that + + align:start position:0% +this analysis say first one says that + + + align:start position:0% +this analysis say first one says that +the you know collusive model fits the + + align:start position:0% +the you know collusive model fits the + + + align:start position:0% +the you know collusive model fits the +data best in 1954 and + + align:start position:0% +data best in 1954 and + + + align:start position:0% +data best in 1954 and +1956 and the static competition model + + align:start position:0% +1956 and the static competition model + + + align:start position:0% +1956 and the static competition model +fits the data best in + + align:start position:0% +fits the data best in + + + align:start position:0% +fits the data best in +1955 so that's his evidence for his main + + align:start position:0% +1955 so that's his evidence for his main + + + align:start position:0% +1955 so that's his evidence for his main +hypothesis that there was this breakdown + + align:start position:0% +hypothesis that there was this breakdown + + + align:start position:0% +hypothesis that there was this breakdown +inclusion and the clusive model fits the + + align:start position:0% +inclusion and the clusive model fits the + + + align:start position:0% +inclusion and the clusive model fits the +patterns best in + + align:start position:0% +patterns best in + + + align:start position:0% +patterns best in +5456 the competitive model in 55 + + align:start position:0% +5456 the competitive model in 55 + + + align:start position:0% +5456 the competitive model in 55 +um further supporting that is you know + + align:start position:0% +um further supporting that is you know + + + align:start position:0% +um further supporting that is you know +his model has a bunch of parameters the + + align:start position:0% +his model has a bunch of parameters the + + + align:start position:0% +his model has a bunch of parameters the +MU and the Delta and the V-Max and + + align:start position:0% +MU and the Delta and the V-Max and + + + align:start position:0% +MU and the Delta and the V-Max and +especially the betas that sort of talk + + align:start position:0% +especially the betas that sort of talk + + + align:start position:0% +especially the betas that sort of talk +about the which relate to the how + + align:start position:0% +about the which relate to the how + + + align:start position:0% +about the which relate to the how +valuable is horsepower how valuable is + + align:start position:0% +valuable is horsepower how valuable is + + + align:start position:0% +valuable is horsepower how valuable is +air conditioning things like that um + + align:start position:0% +air conditioning things like that um + + + align:start position:0% +air conditioning things like that um +what he notes is that if you estimate + + align:start position:0% +what he notes is that if you estimate + + + align:start position:0% +what he notes is that if you estimate +the collusive model in 54 and 56 and + + align:start position:0% +the collusive model in 54 and 56 and + + + align:start position:0% +the collusive model in 54 and 56 and +then estimate the static competition + + align:start position:0% +then estimate the static competition + + + align:start position:0% +then estimate the static competition +model in + + align:start position:0% +model in + + + align:start position:0% +model in +55 the parameters like the betas turn + + align:start position:0% +55 the parameters like the betas turn + + + align:start position:0% +55 the parameters like the betas turn +out to be fairly similar between 54 56 + + align:start position:0% +out to be fairly similar between 54 56 + + + align:start position:0% +out to be fairly similar between 54 56 +and 55 and that's sort of further + + align:start position:0% +and 55 and that's sort of further + + + align:start position:0% +and 55 and that's sort of further +supporting evidence that you know like + + align:start position:0% +supporting evidence that you know like + + + align:start position:0% +supporting evidence that you know like +consumer preferences towards horsepower + + align:start position:0% +consumer preferences towards horsepower + + + align:start position:0% +consumer preferences towards horsepower +should probably be fairly stable over + + align:start position:0% +should probably be fairly stable over + + + align:start position:0% +should probably be fairly stable over +time and so what he notes is that if you + + align:start position:0% +time and so what he notes is that if you + + + align:start position:0% +time and so what he notes is that if you +do this model in these two years the + + align:start position:0% +do this model in these two years the + + + align:start position:0% +do this model in these two years the +other model in 55 then the preference + + align:start position:0% +other model in 55 then the preference + + + align:start position:0% +other model in 55 then the preference +parameters are fairly similar across the + + align:start position:0% +parameters are fairly similar across the + + + align:start position:0% +parameters are fairly similar across the +years um whereas if you try to fix any + + align:start position:0% +years um whereas if you try to fix any + + + align:start position:0% +years um whereas if you try to fix any +one model and use any one model to + + align:start position:0% +one model and use any one model to + + + align:start position:0% +one model and use any one model to +explain what happens the parameters need + + align:start position:0% +explain what happens the parameters need + + + align:start position:0% +explain what happens the parameters need +to change a lot from 54 to 55 from 55 to + + align:start position:0% +to change a lot from 54 to 55 from 55 to + + + align:start position:0% +to change a lot from 54 to 55 from 55 to +56 you know in some sense you need you + + align:start position:0% +56 you know in some sense you need you + + + align:start position:0% +56 you know in some sense you need you +know prices did go down despite the fact + + align:start position:0% +know prices did go down despite the fact + + + align:start position:0% +know prices did go down despite the fact +that demand is going way up and so you + + align:start position:0% +that demand is going way up and so you + + + align:start position:0% +that demand is going way up and so you +need something to say that suddenly cars + + align:start position:0% +need something to say that suddenly cars + + + align:start position:0% +need something to say that suddenly cars +got a lot cheaper and you know cars got + + align:start position:0% +got a lot cheaper and you know cars got + + + align:start position:0% +got a lot cheaper and you know cars got +a lot cheaper to produce and people + + align:start position:0% +a lot cheaper to produce and people + + + align:start position:0% +a lot cheaper to produce and people +valued cars more than they used to Value + + align:start position:0% +valued cars more than they used to Value + + + align:start position:0% +valued cars more than they used to Value +cars during that one year whereas if you + + align:start position:0% +cars during that one year whereas if you + + + align:start position:0% +cars during that one year whereas if you +sort of uh use this change in Behavior + + align:start position:0% +sort of uh use this change in Behavior + + + align:start position:0% +sort of uh use this change in Behavior +then the parameter estimates are fairly + + align:start position:0% +then the parameter estimates are fairly + + + align:start position:0% +then the parameter estimates are fairly +stable across time and so that's + + align:start position:0% +stable across time and so that's + + + align:start position:0% +stable across time and so that's +supporting evidence + + align:start position:0% +supporting evidence + + + align:start position:0% +supporting evidence +um then what's in his counterfactual um + + align:start position:0% +um then what's in his counterfactual um + + + align:start position:0% +um then what's in his counterfactual um +the counterfactual he does is suppose + + align:start position:0% +the counterfactual he does is suppose + + + align:start position:0% +the counterfactual he does is suppose +firms had colluded in 1955 instead of + + align:start position:0% +firms had colluded in 1955 instead of + + + align:start position:0% +firms had colluded in 1955 instead of +engaging in differentiated product + + align:start position:0% +engaging in differentiated product + + + align:start position:0% +engaging in differentiated product +competition uh and what he finds is that + + align:start position:0% +competition uh and what he finds is that + + + align:start position:0% +competition uh and what he finds is that +prices would have been 6% higher uh and + + align:start position:0% +prices would have been 6% higher uh and + + + align:start position:0% +prices would have been 6% higher uh and +demand would have been six 11% lower so + + align:start position:0% +demand would have been six 11% lower so + + + align:start position:0% +demand would have been six 11% lower so +this was you know a 40% jump in Auto + + align:start position:0% +this was you know a 40% jump in Auto + + + align:start position:0% +this was you know a 40% jump in Auto +Sales his model is not fully explaining + + align:start position:0% +Sales his model is not fully explaining + + + align:start position:0% +Sales his model is not fully explaining +it his model is saying I'm explaining uh + + align:start position:0% +it his model is saying I'm explaining uh + + + align:start position:0% +it his model is saying I'm explaining uh +you know a little more than 25% of the + + align:start position:0% +you know a little more than 25% of the + + + align:start position:0% +you know a little more than 25% of the +Boom in auto sales as as coming from uh + + align:start position:0% +Boom in auto sales as as coming from uh + + + align:start position:0% +Boom in auto sales as as coming from uh +as coming from the change in collusion + + align:start position:0% +as coming from the change in collusion + + + align:start position:0% +as coming from the change in collusion +so in some sense you know he's already + + align:start position:0% +so in some sense you know he's already + + + align:start position:0% +so in some sense you know he's already +sort of letting you know that his model + + align:start position:0% +sort of letting you know that his model + + + align:start position:0% +sort of letting you know that his model +at least the model as he's estimated + + align:start position:0% +at least the model as he's estimated + + + align:start position:0% +at least the model as he's estimated +isn't fully correct because it's not + + align:start position:0% +isn't fully correct because it's not + + + align:start position:0% +isn't fully correct because it's not +fully accounting for the jump in sales + + align:start position:0% +fully accounting for the jump in sales + + + align:start position:0% +fully accounting for the jump in sales +now there was a you know 10% jump in + + align:start position:0% +now there was a you know 10% jump in + + + align:start position:0% +now there was a you know 10% jump in +non-auto durable good sales he would + + align:start position:0% +non-auto durable good sales he would + + + align:start position:0% +non-auto durable good sales he would +have said just the sort of background + + align:start position:0% +have said just the sort of background + + + align:start position:0% +have said just the sort of background +change in US economy income or change in + + align:start position:0% +change in US economy income or change in + + + align:start position:0% +change in US economy income or change in +income maybe could have explained 10% + + align:start position:0% +income maybe could have explained 10% + + + align:start position:0% +income maybe could have explained 10% +also but so you thing his model is + + align:start position:0% +also but so you thing his model is + + + align:start position:0% +also but so you thing his model is +explaining part of what's going + + align:start position:0% +explaining part of what's going + + + align:start position:0% +explaining part of what's going +on um but it is you know it is a very + + align:start position:0% +on um but it is you know it is a very + + + align:start position:0% +on um but it is you know it is a very +nice use of the you know use of the + + align:start position:0% +nice use of the you know use of the + + + align:start position:0% +nice use of the you know use of the +counterfactual to give us a sense of + + align:start position:0% +counterfactual to give us a sense of + + + align:start position:0% +counterfactual to give us a sense of +what would have happened in another + + align:start position:0% +what would have happened in another + + + align:start position:0% +what would have happened in another +world and that you know now you know you + + align:start position:0% +world and that you know now you know you + + + align:start position:0% +world and that you know now you know you +just see every IO paper now has + + align:start position:0% +just see every IO paper now has + + + align:start position:0% +just see every IO paper now has +counterfactuals which I think started + + align:start position:0% +counterfactuals which I think started + + + align:start position:0% +counterfactuals which I think started +here + + align:start position:0% +here + + + align:start position:0% +here +um as I said you know if you read the + + align:start position:0% +um as I said you know if you read the + + + align:start position:0% +um as I said you know if you read the +paper there are all kinds of things that + + align:start position:0% +paper there are all kinds of things that + + + align:start position:0% +paper there are all kinds of things that +are going to seem odd to you like you + + align:start position:0% +are going to seem odd to you like you + + + align:start position:0% +are going to seem odd to you like you +know this sort of adoption of the pure + + align:start position:0% +know this sort of adoption of the pure + + + align:start position:0% +know this sort of adoption of the pure +vertical model you know + + align:start position:0% +vertical model you know + + + align:start position:0% +vertical model you know +clearly you know I I don't think the the + + align:start position:0% +clearly you know I I don't think the the + + + align:start position:0% +clearly you know I I don't think the the +the Mercury Montclair and the Chevy ba + + align:start position:0% +the Mercury Montclair and the Chevy ba + + + align:start position:0% +the Mercury Montclair and the Chevy ba +air are so similar that there would be + + align:start position:0% +air are so similar that there would be + + + align:start position:0% +air are so similar that there would be +purely Bertrand competition between them + + align:start position:0% +purely Bertrand competition between them + + + align:start position:0% +purely Bertrand competition between them +you know if you thought about doing that + + align:start position:0% +you know if you thought about doing that + + + align:start position:0% +you know if you thought about doing that +in today's car market you know there are + + align:start position:0% +in today's car market you know there are + + + align:start position:0% +in today's car market you know there are +pickup trucks um there are convertibles + + align:start position:0% +pickup trucks um there are convertibles + + + align:start position:0% +pickup trucks um there are convertibles +there are sport sedans there are you + + align:start position:0% +there are sport sedans there are you + + + align:start position:0% +there are sport sedans there are you +know electric vehicles if you try to put + + align:start position:0% +know electric vehicles if you try to put + + + align:start position:0% +know electric vehicles if you try to put +them on a one-dimensional quality space + + align:start position:0% +them on a one-dimensional quality space + + + align:start position:0% +them on a one-dimensional quality space +you know some of them like some pickup + + align:start position:0% +you know some of them like some pickup + + + align:start position:0% +you know some of them like some pickup +truck is going to nearly coincide with a + + align:start position:0% +truck is going to nearly coincide with a + + + align:start position:0% +truck is going to nearly coincide with a +Honda Accord and you know + + align:start position:0% +Honda Accord and you know + + + align:start position:0% +Honda Accord and you know +clearly you need to have some kind of + + align:start position:0% +clearly you need to have some kind of + + + align:start position:0% +clearly you need to have some kind of +horizontal differentiation as well as as + + align:start position:0% +horizontal differentiation as well as as + + + align:start position:0% +horizontal differentiation as well as as +vertical + + align:start position:0% +vertical + + + align:start position:0% +vertical +differentiation um you know the anyway a + + align:start position:0% +differentiation um you know the anyway a + + + align:start position:0% +differentiation um you know the anyway a +number of aspects when you when you sort + + align:start position:0% +number of aspects when you when you sort + + + align:start position:0% +number of aspects when you when you sort +of see how people do modern empirical + + align:start position:0% +of see how people do modern empirical + + + align:start position:0% +of see how people do modern empirical +work that look very different but I + + align:start position:0% +work that look very different but I + + + align:start position:0% +work that look very different but I +think the in some ways + + align:start position:0% +think the in some ways + + + align:start position:0% +think the in some ways +the basic ideas still seem very spoton + + align:start position:0% +the basic ideas still seem very spoton + + + align:start position:0% +the basic ideas still seem very spoton +in particular one thing I think he does + + align:start position:0% +in particular one thing I think he does + + + align:start position:0% +in particular one thing I think he does +better than many current models is he + + align:start position:0% +better than many current models is he + + + align:start position:0% +better than many current models is he +does take very seriously this idea of I + + align:start position:0% +does take very seriously this idea of I + + + align:start position:0% +does take very seriously this idea of I +want this empir this structure work only + + align:start position:0% +want this empir this structure work only + + + align:start position:0% +want this empir this structure work only +works if I choose the right framework + + align:start position:0% +works if I choose the right framework + + + align:start position:0% +works if I choose the right framework +and he's going to sort of come up with + + align:start position:0% +and he's going to sort of come up with + + + align:start position:0% +and he's going to sort of come up with +four different models and put a lot of + + align:start position:0% +four different models and put a lot of + + + align:start position:0% +four different models and put a lot of +effort into testing the four different + + align:start position:0% +effort into testing the four different + + + align:start position:0% +effort into testing the four different +structural models against each other + + align:start position:0% +structural models against each other + + + align:start position:0% +structural models against each other +whereas now very often it's like it's + + align:start position:0% +whereas now very often it's like it's + + + align:start position:0% +whereas now very often it's like it's +hard to estimate even any one model so + + align:start position:0% +hard to estimate even any one model so + + + align:start position:0% +hard to estimate even any one model so +you see a lot of papers that have here's + + align:start position:0% +you see a lot of papers that have here's + + + align:start position:0% +you see a lot of papers that have here's +my one model and I can estimate that and + + align:start position:0% +my one model and I can estimate that and + + + align:start position:0% +my one model and I can estimate that and +I can talk about how well it fits by + + align:start position:0% +I can talk about how well it fits by + + + align:start position:0% +I can talk about how well it fits by +sort of putting up a graph and showing + + align:start position:0% +sort of putting up a graph and showing + + + align:start position:0% +sort of putting up a graph and showing +some x's and y's and show the Y's are + + align:start position:0% +some x's and y's and show the Y's are + + + align:start position:0% +some x's and y's and show the Y's are +close to the Y hats but um you know I + + align:start position:0% +close to the Y hats but um you know I + + + align:start position:0% +close to the Y hats but um you know I +think it is doing a very nice job on + + align:start position:0% +think it is doing a very nice job on + + + align:start position:0% +think it is doing a very nice job on +that + + align:start position:0% +that + + + align:start position:0% +that +Dimension so uh any questions on breast + + align:start position:0% +Dimension so uh any questions on breast + + + align:start position:0% +Dimension so uh any questions on breast +andan yeah why would like collusion + + align:start position:0% +andan yeah why would like collusion + + + align:start position:0% +andan yeah why would like collusion +break down for just one year and then + + align:start position:0% +break down for just one year and then + + + align:start position:0% +break down for just one year and then +all of a sudden the next year it's back + + align:start position:0% +all of a sudden the next year it's back + + + align:start position:0% +all of a sudden the next year it's back +at it again yeah so + + align:start position:0% + + + + align:start position:0% + +um you a little hard to say you know the + + align:start position:0% +um you a little hard to say you know the + + + align:start position:0% +um you a little hard to say you know the +the um I I will in a couple weeks be + + align:start position:0% +the um I I will in a couple weeks be + + + align:start position:0% +the um I I will in a couple weeks be +discussing sort of models of repeated + + align:start position:0% +discussing sort of models of repeated + + + align:start position:0% +discussing sort of models of repeated +game collusion and in you know models of + + align:start position:0% +game collusion and in you know models of + + + align:start position:0% +game collusion and in you know models of +repeated game collusion you do get this + + align:start position:0% +repeated game collusion you do get this + + + align:start position:0% +repeated game collusion you do get this +phenomenon of the way you support + + align:start position:0% +phenomenon of the way you support + + + align:start position:0% +phenomenon of the way you support +collusion is via price Wars to punish + + align:start position:0% +collusion is via price Wars to punish + + + align:start position:0% +collusion is via price Wars to punish +somebody who cheats so that is if you + + align:start position:0% +somebody who cheats so that is if you + + + align:start position:0% +somebody who cheats so that is if you +you're trying to collude you think that + + align:start position:0% +you're trying to collude you think that + + + align:start position:0% +you're trying to collude you think that +someone is cheating on the collusive + + align:start position:0% +someone is cheating on the collusive + + + align:start position:0% +someone is cheating on the collusive +agreements and their dealers are + + align:start position:0% +agreements and their dealers are + + + align:start position:0% +agreements and their dealers are +charging you know like you've all agreed + + align:start position:0% +charging you know like you've all agreed + + + align:start position:0% +charging you know like you've all agreed +that we're going to charge $7,000 for + + align:start position:0% +that we're going to charge $7,000 for + + + align:start position:0% +that we're going to charge $7,000 for +our Bel a and Montclair and you think + + align:start position:0% +our Bel a and Montclair and you think + + + align:start position:0% +our Bel a and Montclair and you think +the other guys dealers are actually + + align:start position:0% +the other guys dealers are actually + + + align:start position:0% +the other guys dealers are actually +giving consumers cuts and offering it + + align:start position:0% +giving consumers cuts and offering it + + + align:start position:0% +giving consumers cuts and offering it +for 6,500 instead of 7,000 even though + + align:start position:0% +for 6,500 instead of 7,000 even though + + + align:start position:0% +for 6,500 instead of 7,000 even though +the list price is 7,000 you might decide + + align:start position:0% +the list price is 7,000 you might decide + + + align:start position:0% +the list price is 7,000 you might decide +you know + + align:start position:0% +you know + + + align:start position:0% +you know +we're GNA have to punish you for doing + + align:start position:0% +we're GNA have to punish you for doing + + + align:start position:0% +we're GNA have to punish you for doing +that and we're g to have we're going to + + align:start position:0% +that and we're g to have we're going to + + + align:start position:0% +that and we're g to have we're going to +sort of abandon colluding this year and + + align:start position:0% +sort of abandon colluding this year and + + + align:start position:0% +sort of abandon colluding this year and +we're going to all learn how bad it is + + align:start position:0% +we're going to all learn how bad it is + + + align:start position:0% +we're going to all learn how bad it is +and then go back to cooperating the next + + align:start position:0% +and then go back to cooperating the next + + + align:start position:0% +and then go back to cooperating the next +year um you know so you could tell some + + align:start position:0% +year um you know so you could tell some + + + align:start position:0% +year um you know so you could tell some +story like that I I I don't you know he + + align:start position:0% +story like that I I I don't you know he + + + align:start position:0% +story like that I I I don't you know he +doesn't have + + align:start position:0% +doesn't have + + + align:start position:0% +doesn't have +any there there's no discussion in the + + align:start position:0% +any there there's no discussion in the + + + align:start position:0% +any there there's no discussion in the +paper of like why collusion would have + + align:start position:0% +paper of like why collusion would have + + + align:start position:0% +paper of like why collusion would have +brought down and there's no narrative + + align:start position:0% +brought down and there's no narrative + + + align:start position:0% +brought down and there's no narrative +evidence at all of the executives + + align:start position:0% +evidence at all of the executives + + + align:start position:0% +evidence at all of the executives +talking to each other and having + + align:start position:0% +talking to each other and having + + + align:start position:0% +talking to each other and having +anything going wrong um but it is true + + align:start position:0% +anything going wrong um but it is true + + + align:start position:0% +anything going wrong um but it is true +that actually you know like I + + align:start position:0% +that actually you know like I + + + align:start position:0% +that actually you know like I +think when we look at we're going to + + align:start position:0% +think when we look at we're going to + + + align:start position:0% +think when we look at we're going to +start study several other papers on + + align:start position:0% +start study several other papers on + + + align:start position:0% +start study several other papers on +cartels like almost all the cartels we + + align:start position:0% +cartels like almost all the cartels we + + + align:start position:0% +cartels like almost all the cartels we +study are finite lived like they go on + + align:start position:0% +study are finite lived like they go on + + + align:start position:0% +study are finite lived like they go on +they're colluding with each other for + + align:start position:0% +they're colluding with each other for + + + align:start position:0% +they're colluding with each other for +some number of years and then it breaks + + align:start position:0% +some number of years and then it breaks + + + align:start position:0% +some number of years and then it breaks +down at some point um you know in part + + align:start position:0% +down at some point um you know in part + + + align:start position:0% +down at some point um you know in part +because also it's illegal um but it's + + align:start position:0% +because also it's illegal um but it's + + + align:start position:0% +because also it's illegal um but it's +you know so people are afraid of getting + + align:start position:0% +you know so people are afraid of getting + + + align:start position:0% +you know so people are afraid of getting +caught or something goes wrong and they + + align:start position:0% +caught or something goes wrong and they + + + align:start position:0% +caught or something goes wrong and they +can't discuss it with each other and get + + align:start position:0% +can't discuss it with each other and get + + + align:start position:0% +can't discuss it with each other and get +things back + + align:start position:0% + + + + align:start position:0% + +um anybody + + align:start position:0% + + + + align:start position:0% + +else okay um so second thing I I was + + align:start position:0% +else okay um so second thing I I was + + + align:start position:0% +else okay um so second thing I I was +going to do then I was going to jump + + align:start position:0% +going to do then I was going to jump + + + align:start position:0% +going to do then I was going to jump +ahead before I get to Miller and + + align:start position:0% +ahead before I get to Miller and + + + align:start position:0% +ahead before I get to Miller and +Weinberg and just do do uh you know half + + align:start position:0% +Weinberg and just do do uh you know half + + + align:start position:0% +Weinberg and just do do uh you know half +hour 40 minutes on oligopoly price + + align:start position:0% +hour 40 minutes on oligopoly price + + + align:start position:0% +hour 40 minutes on oligopoly price +discrimination and you know I think in + + align:start position:0% +discrimination and you know I think in + + + align:start position:0% +discrimination and you know I think in +terr's textbook and in many other places + + align:start position:0% +terr's textbook and in many other places + + + align:start position:0% +terr's textbook and in many other places +price discrimination is typically taught + + align:start position:0% +price discrimination is typically taught + + + align:start position:0% +price discrimination is typically taught +as a monopoly topic um and you know I + + align:start position:0% +as a monopoly topic um and you know I + + + align:start position:0% +as a monopoly topic um and you know I +think that was because historically you + + align:start position:0% +think that was because historically you + + + align:start position:0% +think that was because historically you +had Monopoly and perfect competition as + + align:start position:0% +had Monopoly and perfect competition as + + + align:start position:0% +had Monopoly and perfect competition as +the two models with perfect competition + + align:start position:0% +the two models with perfect competition + + + align:start position:0% +the two models with perfect competition +price equals marginal cost you can't + + align:start position:0% +price equals marginal cost you can't + + + align:start position:0% +price equals marginal cost you can't +price discriminate but you know with + + align:start position:0% +price discriminate but you know with + + + align:start position:0% +price discriminate but you know with +imperfect competition price isn't equal + + align:start position:0% +imperfect competition price isn't equal + + + align:start position:0% +imperfect competition price isn't equal +to marginal cost there's no reason why + + align:start position:0% +to marginal cost there's no reason why + + + align:start position:0% +to marginal cost there's no reason why +oligopolies can't price discriminate + + align:start position:0% +oligopolies can't price discriminate + + + align:start position:0% +oligopolies can't price discriminate +just like monopolies price discriminate + + align:start position:0% +just like monopolies price discriminate + + + align:start position:0% +just like monopolies price discriminate +uh in particular there was an early + + align:start position:0% +uh in particular there was an early + + + align:start position:0% +uh in particular there was an early +paper in this um Bornstein and Rose uh + + align:start position:0% +paper in this um Bornstein and Rose uh + + + align:start position:0% +paper in this um Bornstein and Rose uh +1994 jpe look at Price dispersion in + + align:start position:0% +1994 jpe look at Price dispersion in + + + align:start position:0% +1994 jpe look at Price dispersion in +Airline markets and what they find is + + align:start position:0% +Airline markets and what they find is + + + align:start position:0% +Airline markets and what they find is +that if you look at uh Airline City pair + + align:start position:0% +that if you look at uh Airline City pair + + + align:start position:0% +that if you look at uh Airline City pair +markets like you know Boston to New York + + align:start position:0% +markets like you know Boston to New York + + + align:start position:0% +markets like you know Boston to New York +New York to Phoenix + + align:start position:0% +New York to Phoenix + + + align:start position:0% +New York to Phoenix +whatever the markets that have more + + align:start position:0% +whatever the markets that have more + + + align:start position:0% +whatever the markets that have more +competition tend to have more price + + align:start position:0% +competition tend to have more price + + + align:start position:0% +competition tend to have more price +dispers + + align:start position:0% +dispers + + + align:start position:0% +dispers +on the same plane so like you know if + + align:start position:0% +on the same plane so like you know if + + + align:start position:0% +on the same plane so like you know if +you look at a flight you know from + + align:start position:0% +you look at a flight you know from + + + align:start position:0% +you look at a flight you know from +Boston to New York there are a lot of + + align:start position:0% +Boston to New York there are a lot of + + + align:start position:0% +Boston to New York there are a lot of +people on that flight they all PID + + align:start position:0% +people on that flight they all PID + + + align:start position:0% +people on that flight they all PID +different prices and the Bornstein Row's + + align:start position:0% +different prices and the Bornstein Row's + + + align:start position:0% +different prices and the Bornstein Row's +finding is that the heterogeneity in + + align:start position:0% +finding is that the heterogeneity in + + + align:start position:0% +finding is that the heterogeneity in +prices on a flight is actually larger in + + align:start position:0% +prices on a flight is actually larger in + + + align:start position:0% +prices on a flight is actually larger in +the more competitive markets not smaller + + align:start position:0% +the more competitive markets not smaller + + + align:start position:0% +the more competitive markets not smaller +and the more competitive markets um so + + align:start position:0% +and the more competitive markets um so + + + align:start position:0% +and the more competitive markets um so +it's an indication that it's not the + + align:start position:0% +it's an indication that it's not the + + + align:start position:0% +it's an indication that it's not the +case that competition that we often see + + align:start position:0% +case that competition that we often see + + + align:start position:0% +case that competition that we often see +makes it impossible to price + + align:start position:0% +makes it impossible to price + + + align:start position:0% +makes it impossible to price +discriminate okay so how would we model + + align:start position:0% +discriminate okay so how would we model + + + align:start position:0% +discriminate okay so how would we model +price discrimination well let me first + + align:start position:0% +price discrimination well let me first + + + align:start position:0% +price discrimination well let me first +start start with um third degree price + + align:start position:0% +start start with um third degree price + + + align:start position:0% +start start with um third degree price +discrimination so you have you know two + + align:start position:0% +discrimination so you have you know two + + + align:start position:0% +discrimination so you have you know two +firms competing in two separate markets + + align:start position:0% +firms competing in two separate markets + + + align:start position:0% +firms competing in two separate markets +and suppos there's no cross Market + + align:start position:0% +and suppos there's no cross Market + + + align:start position:0% +and suppos there's no cross Market +Arbitrage so you know this is two firms + + align:start position:0% +Arbitrage so you know this is two firms + + + align:start position:0% +Arbitrage so you know this is two firms +selling uh cell phone service in Boston + + align:start position:0% +selling uh cell phone service in Boston + + + align:start position:0% +selling uh cell phone service in Boston +the same two firm selling or two firm + + align:start position:0% +the same two firm selling or two firm + + + align:start position:0% +the same two firm selling or two firm +selling cable TV service in Boston and + + align:start position:0% +selling cable TV service in Boston and + + + align:start position:0% +selling cable TV service in Boston and +selling cable TV service in Philadelphia + + align:start position:0% +selling cable TV service in Philadelphia + + + align:start position:0% +selling cable TV service in Philadelphia +you know you can't arbit you can't like + + align:start position:0% +you know you can't arbit you can't like + + + align:start position:0% +you know you can't arbit you can't like +get a buy cable TV in Boston and then + + align:start position:0% +get a buy cable TV in Boston and then + + + align:start position:0% +get a buy cable TV in Boston and then +use it in Philadelphia or vice versa you + + align:start position:0% +use it in Philadelphia or vice versa you + + + align:start position:0% +use it in Philadelphia or vice versa you +have to buy the service at your service + + align:start position:0% +have to buy the service at your service + + + align:start position:0% +have to buy the service at your service +address um and you know so you could + + align:start position:0% +address um and you know so you could + + + align:start position:0% +address um and you know so you could +have these same two firms competing and + + align:start position:0% +have these same two firms competing and + + + align:start position:0% +have these same two firms competing and +they're competing in these two different + + align:start position:0% +they're competing in these two different + + + align:start position:0% +they're competing in these two different +markets okay um so suppose that you know + + align:start position:0% +markets okay um so suppose that you know + + + align:start position:0% +markets okay um so suppose that you know +every each of the markets has hotelling + + align:start position:0% +every each of the markets has hotelling + + + align:start position:0% +every each of the markets has hotelling +preferences and the type Theta consumers + + align:start position:0% +preferences and the type Theta consumers + + + align:start position:0% +preferences and the type Theta consumers +in Market M get + + align:start position:0% +in Market M get + + + align:start position:0% +in Market M get +utility V minus P price of firm one and + + align:start position:0% +utility V minus P price of firm one and + + + align:start position:0% +utility V minus P price of firm one and +M minus TM Theta if they buy from firm + + align:start position:0% +M minus TM Theta if they buy from firm + + + align:start position:0% +M minus TM Theta if they buy from firm +one and V minus p2m minus tm1 minus + + align:start position:0% +one and V minus p2m minus tm1 minus + + + align:start position:0% +one and V minus p2m minus tm1 minus +Theta if they buy it from firm two so + + align:start position:0% +Theta if they buy it from firm two so + + + align:start position:0% +Theta if they buy it from firm two so +this is just competition on two + + align:start position:0% +this is just competition on two + + + align:start position:0% +this is just competition on two +lines you know this + + align:start position:0% +lines you know this + + + align:start position:0% +lines you know this +is this is Market one and it has some + + align:start position:0% +is this is Market one and it has some + + + align:start position:0% +is this is Market one and it has some +parameter + + align:start position:0% +parameter + + + align:start position:0% +parameter +T1 and this is Market + + align:start position:0% + + + + align:start position:0% + +2 uh and it has some parameter + + align:start position:0% +2 uh and it has some parameter + + + align:start position:0% +2 uh and it has some parameter +T2 I think I made T2 the high + + align:start position:0% +T2 I think I made T2 the high + + + align:start position:0% +T2 I think I made T2 the high +guys okay so you just have you're + + align:start position:0% +guys okay so you just have you're + + + align:start position:0% +guys okay so you just have you're +competing on this line you're competing + + align:start position:0% +competing on this line you're competing + + + align:start position:0% +competing on this line you're competing +on this line these markets are + + align:start position:0% +on this line these markets are + + + align:start position:0% +on this line these markets are +completely separate well you + + align:start position:0% + + + + align:start position:0% + +know price discrimination is just just + + align:start position:0% +know price discrimination is just just + + + align:start position:0% +know price discrimination is just just +like third degree in Monopoly it's just + + align:start position:0% +like third degree in Monopoly it's just + + + align:start position:0% +like third degree in Monopoly it's just +two totally separate markets so if we + + align:start position:0% +two totally separate markets so if we + + + align:start position:0% +two totally separate markets so if we +have competition here what's going to + + align:start position:0% +have competition here what's going to + + + align:start position:0% +have competition here what's going to +happen is you're going to get you know P + + align:start position:0% +happen is you're going to get you know P + + + align:start position:0% +happen is you're going to get you know P +star equals c plus T1 you have + + align:start position:0% +star equals c plus T1 you have + + + align:start position:0% +star equals c plus T1 you have +competition here you're going to get P2 + + align:start position:0% +competition here you're going to get P2 + + + align:start position:0% +competition here you're going to get P2 +star is C plus + + align:start position:0% +star is C plus + + + align:start position:0% +star is C plus +T2 right we just compete on a line here + + align:start position:0% +T2 right we just compete on a line here + + + align:start position:0% +T2 right we just compete on a line here +we get hoteling here we compete on this + + align:start position:0% +we get hoteling here we compete on this + + + align:start position:0% +we get hoteling here we compete on this +line we get hoteling here + + align:start position:0% +line we get hoteling here + + + align:start position:0% +line we get hoteling here +the prices are different across markets + + align:start position:0% +the prices are different across markets + + + align:start position:0% +the prices are different across markets +we're discriminating against consumers + + align:start position:0% +we're discriminating against consumers + + + align:start position:0% +we're discriminating against consumers +in this market you the high types end up + + align:start position:0% +in this market you the high types end up + + + align:start position:0% +in this market you the high types end up +paying more what are high types a high + + align:start position:0% +paying more what are high types a high + + + align:start position:0% +paying more what are high types a high +type is somebody who lives in a market + + align:start position:0% +type is somebody who lives in a market + + + align:start position:0% +type is somebody who lives in a market +where there's more heterogen Adan taste + + align:start position:0% +where there's more heterogen Adan taste + + + align:start position:0% +where there's more heterogen Adan taste +so if there's more heterogen Adan taste + + align:start position:0% +so if there's more heterogen Adan taste + + + align:start position:0% +so if there's more heterogen Adan taste +in Market 2 than in Market one then + + align:start position:0% +in Market 2 than in Market one then + + + align:start position:0% +in Market 2 than in Market one then +people in Market 2 end up paying more + + align:start position:0% +people in Market 2 end up paying more + + + align:start position:0% +people in Market 2 end up paying more +than people in Market + + align:start position:0% +than people in Market + + + align:start position:0% +than people in Market +one + + align:start position:0% +one + + + align:start position:0% +one +okay um the one policy question you get + + align:start position:0% +okay um the one policy question you get + + + align:start position:0% +okay um the one policy question you get +is well what would happen in a market + + align:start position:0% +is well what would happen in a market + + + align:start position:0% +is well what would happen in a market +like this if we banned um people + + align:start position:0% +like this if we banned um people + + + align:start position:0% +like this if we banned um people +from uh what would happen if we Bann + + align:start position:0% +from uh what would happen if we Bann + + + align:start position:0% +from uh what would happen if we Bann +people from uh price discriminating and + + align:start position:0% +people from uh price discriminating and + + + align:start position:0% +people from uh price discriminating and +say you have to charge the same Mar + + align:start position:0% +say you have to charge the same Mar + + + align:start position:0% +say you have to charge the same Mar +price in both markets uh it turns out + + align:start position:0% +price in both markets uh it turns out + + + align:start position:0% +price in both markets uh it turns out +like in this model you just sort of get + + align:start position:0% +like in this model you just sort of get + + + align:start position:0% +like in this model you just sort of get +an average markup so if instead + + align:start position:0% +an average markup so if instead + + + align:start position:0% +an average markup so if instead +of being allowed to price separately you + + align:start position:0% +of being allowed to price separately you + + + align:start position:0% +of being allowed to price separately you +force them to charge the same price what + + align:start position:0% +force them to charge the same price what + + + align:start position:0% +force them to charge the same price what +you get is price equals C + 2 T1 T2 over + + align:start position:0% +you get is price equals C + 2 T1 T2 over + + + align:start position:0% +you get is price equals C + 2 T1 T2 over +T1 + T2 + + align:start position:0% +T1 + T2 + + + align:start position:0% +T1 + T2 +okay um this is uh what mathematicians + + align:start position:0% +okay um this is uh what mathematicians + + + align:start position:0% +okay um this is uh what mathematicians +refer to as the harmonic + + align:start position:0% + + + + align:start position:0% + +mean of um T1 and T2 and you know basic + + align:start position:0% +mean of um T1 and T2 and you know basic + + + align:start position:0% +mean of um T1 and T2 and you know basic +math fact is that if T1 is less than T2 + + align:start position:0% +math fact is that if T1 is less than T2 + + + align:start position:0% +math fact is that if T1 is less than T2 +then T1 is less than 2 T1 T2 over T1 + + + align:start position:0% +then T1 is less than 2 T1 T2 over T1 + + + + align:start position:0% +then T1 is less than 2 T1 T2 over T1 + +T2 Which is less than or equal to T1 1 + + + align:start position:0% +T2 Which is less than or equal to T1 1 + + + + align:start position:0% +T2 Which is less than or equal to T1 1 + +T2 over 2 less than or equal to T2 okay + + align:start position:0% +T2 over 2 less than or equal to T2 okay + + + align:start position:0% +T2 over 2 less than or equal to T2 okay +this is the called the arithmetic + + align:start position:0% +this is the called the arithmetic + + + align:start position:0% +this is the called the arithmetic +harmonic mean inequality so it it's the + + align:start position:0% +harmonic mean inequality so it it's the + + + align:start position:0% +harmonic mean inequality so it it's the +you can think of this as this is the + + align:start position:0% +you can think of this as this is the + + + align:start position:0% +you can think of this as this is the +reciprocal of the average of the + + align:start position:0% +reciprocal of the average of the + + + align:start position:0% +reciprocal of the average of the +reciprocals of T1 and T2 so it always + + align:start position:0% +reciprocals of T1 and T2 so it always + + + align:start position:0% +reciprocals of T1 and T2 so it always +lies between T1 and T2 and it is less + + align:start position:0% +lies between T1 and T2 and it is less + + + align:start position:0% +lies between T1 and T2 and it is less +than the arithmetic mean of T1 and T2 + + align:start position:0% +than the arithmetic mean of T1 and T2 + + + align:start position:0% +than the arithmetic mean of T1 and T2 +but justes the way the math works this + + align:start position:0% +but justes the way the math works this + + + align:start position:0% +but justes the way the math works this +is the price that you end up charging if + + align:start position:0% +is the price that you end up charging if + + + align:start position:0% +is the price that you end up charging if +you ban price discrimination um so what + + align:start position:0% +you ban price discrimination um so what + + + align:start position:0% +you ban price discrimination um so what +is Banning price discrimination do you + + align:start position:0% +is Banning price discrimination do you + + + align:start position:0% +is Banning price discrimination do you +know typically it makes the high types + + align:start position:0% +know typically it makes the high types + + + align:start position:0% +know typically it makes the high types +better off typically it makes the low + + align:start position:0% +better off typically it makes the low + + + align:start position:0% +better off typically it makes the low +types worse off um it does eliminate a + + align:start position:0% +types worse off um it does eliminate a + + + align:start position:0% +types worse off um it does eliminate a +misallocation of markets you know in + + align:start position:0% +misallocation of markets you know in + + + align:start position:0% +misallocation of markets you know in +many models if you have a high price in + + align:start position:0% +many models if you have a high price in + + + align:start position:0% +many models if you have a high price in +one market and a low price in another + + align:start position:0% +one market and a low price in another + + + align:start position:0% +one market and a low price in another +Market there are people in the high + + align:start position:0% +Market there are people in the high + + + align:start position:0% +Market there are people in the high +Market who would like the good who + + align:start position:0% +Market who would like the good who + + + align:start position:0% +Market who would like the good who +aren't getting it and there are people + + align:start position:0% +aren't getting it and there are people + + + align:start position:0% +aren't getting it and there are people +in the low Market who don't like the + + align:start position:0% +in the low Market who don't like the + + + align:start position:0% +in the low Market who don't like the +good as much who are getting it that's a + + align:start position:0% +good as much who are getting it that's a + + + align:start position:0% +good as much who are getting it that's a +misallocation like there is in price + + align:start position:0% +misallocation like there is in price + + + align:start position:0% +misallocation like there is in price +discrimination models um so Banning + + align:start position:0% +discrimination models um so Banning + + + align:start position:0% +discrimination models um so Banning +price eliminates that + + align:start position:0% +price eliminates that + + + align:start position:0% +price eliminates that +inefficiency that inefficiency isn't + + align:start position:0% +inefficiency that inefficiency isn't + + + align:start position:0% +inefficiency that inefficiency isn't +present in hoteling because in hoteling + + align:start position:0% +present in hoteling because in hoteling + + + align:start position:0% +present in hoteling because in hoteling +everybody buys at least if he is big + + align:start position:0% +everybody buys at least if he is big + + + align:start position:0% +everybody buys at least if he is big +enough um and then you know + + align:start position:0% +enough um and then you know + + + align:start position:0% +enough um and then you know +welfare can go either way um so there + + align:start position:0% +welfare can go either way um so there + + + align:start position:0% +welfare can go either way um so there +are you know you know here again there + + align:start position:0% +are you know you know here again there + + + align:start position:0% +are you know you know here again there +are no welfare changes it's just a + + align:start position:0% +are no welfare changes it's just a + + + align:start position:0% +are no welfare changes it's just a +transfer because everybody buy you know + + align:start position:0% +transfer because everybody buy you know + + + align:start position:0% +transfer because everybody buy you know +all all efficient transactions take + + align:start position:0% +all all efficient transactions take + + + align:start position:0% +all all efficient transactions take +place the first best is achieved in both + + align:start position:0% +place the first best is achieved in both + + + align:start position:0% +place the first best is achieved in both +both models um so it's just a pure + + align:start position:0% +both models um so it's just a pure + + + align:start position:0% +both models um so it's just a pure +transfer but in general you know Banning + + align:start position:0% +transfer but in general you know Banning + + + align:start position:0% +transfer but in general you know Banning +price discrimination can increase so + + align:start position:0% +price discrimination can increase so + + + align:start position:0% +price discrimination can increase so +total social welfare or it can decrease + + align:start position:0% +total social welfare or it can decrease + + + align:start position:0% +total social welfare or it can decrease +total social + + align:start position:0% +total social + + + align:start position:0% +total social +welfare + + align:start position:0% +welfare + + + align:start position:0% +welfare +um okay um there's a set of papers in + + align:start position:0% +um okay um there's a set of papers in + + + align:start position:0% +um okay um there's a set of papers in +the 1980s noting that this is the + + align:start position:0% +the 1980s noting that this is the + + + align:start position:0% +the 1980s noting that this is the +typical effect of banning price + + align:start position:0% +typical effect of banning price + + + align:start position:0% +typical effect of banning price +discrimination in oligopoly markets but + + align:start position:0% +discrimination in oligopoly markets but + + + align:start position:0% +discrimination in oligopoly markets but +the typical effects don't have to hold + + align:start position:0% +the typical effects don't have to hold + + + align:start position:0% +the typical effects don't have to hold +um so there's a paper by T and Vias a88 + + align:start position:0% +um so there's a paper by T and Vias a88 + + + align:start position:0% +um so there's a paper by T and Vias a88 +that makes the point that allowing price + + align:start position:0% +that makes the point that allowing price + + + align:start position:0% +that makes the point that allowing price +discrimination can make all consumers + + align:start position:0% +discrimination can make all consumers + + + align:start position:0% +discrimination can make all consumers +better off so price discrimination can + + align:start position:0% +better off so price discrimination can + + + align:start position:0% +better off so price discrimination can +make everybody better off um because of + + align:start position:0% +make everybody better off um because of + + + align:start position:0% +make everybody better off um because of +this effect that t and Vias highlight + + align:start position:0% +this effect that t and Vias highlight + + + align:start position:0% +this effect that t and Vias highlight +when you let firms price discriminate it + + align:start position:0% +when you let firms price discriminate it + + + align:start position:0% +when you let firms price discriminate it +lets firms aggressively Target rals + + align:start position:0% +lets firms aggressively Target rals + + + align:start position:0% +lets firms aggressively Target rals +natural + + align:start position:0% +natural + + + align:start position:0% +natural +consumers uh and that can sort of + + align:start position:0% +consumers uh and that can sort of + + + align:start position:0% +consumers uh and that can sort of +intensify price competition so the exam + + align:start position:0% +intensify price competition so the exam + + + align:start position:0% +intensify price competition so the exam +simplest example that t and Vias gave + + align:start position:0% +simplest example that t and Vias gave + + + align:start position:0% +simplest example that t and Vias gave +was you know consider again the + + align:start position:0% +was you know consider again the + + + align:start position:0% +was you know consider again the +hotelling model and I'm going to give + + align:start position:0% +hotelling model and I'm going to give + + + align:start position:0% +hotelling model and I'm going to give +the hotelling model a different + + align:start position:0% +the hotelling model a different + + + align:start position:0% +the hotelling model a different +interpretation so we have these two + + align:start position:0% +interpretation so we have these two + + + align:start position:0% +interpretation so we have these two +firms and they're + + align:start position:0% +firms and they're + + + align:start position:0% +firms and they're +competing and the consumers have some + + align:start position:0% +competing and the consumers have some + + + align:start position:0% +competing and the consumers have some +types + + align:start position:0% +types + + + align:start position:0% +types +data and I'm going to assume that um the + + align:start position:0% +data and I'm going to assume that um the + + + align:start position:0% +data and I'm going to assume that um the +firms can observe Theta you know so + + align:start position:0% +firms can observe Theta you know so + + + align:start position:0% +firms can observe Theta you know so +maybe these are two firms uh selling + + align:start position:0% +maybe these are two firms uh selling + + + align:start position:0% +maybe these are two firms uh selling +Lumber to home builders and they know + + align:start position:0% +Lumber to home builders and they know + + + align:start position:0% +Lumber to home builders and they know +where the home builder job site is and + + align:start position:0% +where the home builder job site is and + + + align:start position:0% +where the home builder job site is and +so they know how long it's going to take + + align:start position:0% +so they know how long it's going to take + + + align:start position:0% +so they know how long it's going to take +the home builder to truck the lumber + + align:start position:0% +the home builder to truck the lumber + + + align:start position:0% +the home builder to truck the lumber +from their warehouse to his Factory site + + align:start position:0% +from their warehouse to his Factory site + + + align:start position:0% +from their warehouse to his Factory site +so they know his Theta and that's the + + align:start position:0% +so they know his Theta and that's the + + + align:start position:0% +so they know his Theta and that's the +Theta is determining willingness to pay + + align:start position:0% +Theta is determining willingness to pay + + + align:start position:0% +Theta is determining willingness to pay +you know through some means that's known + + align:start position:0% +you know through some means that's known + + + align:start position:0% +you know through some means that's known +to the + + align:start position:0% +to the + + + align:start position:0% +to the +sellers and so here you know + + align:start position:0% +sellers and so here you know + + + align:start position:0% +sellers and so here you know +discrimination would be firm set Theta + + align:start position:0% +discrimination would be firm set Theta + + + align:start position:0% +discrimination would be firm set Theta +dependent prices instead of theta + + align:start position:0% +dependent prices instead of theta + + + align:start position:0% +dependent prices instead of theta +independent prices because they observe + + align:start position:0% +independent prices because they observe + + + align:start position:0% +independent prices because they observe +Theta okay well first you know what + + align:start position:0% +Theta okay well first you know what + + + align:start position:0% +Theta okay well first you know what +happens in this model if firms are if + + align:start position:0% +happens in this model if firms are if + + + align:start position:0% +happens in this model if firms are if +they're not allowed to to um price + + align:start position:0% +they're not allowed to to um price + + + align:start position:0% +they're not allowed to to um price +discriminate then you just get P star + + align:start position:0% +discriminate then you just get P star + + + align:start position:0% +discriminate then you just get P star +equals c plus + + align:start position:0% +equals c plus + + + align:start position:0% +equals c plus +T right because if if I know the + + align:start position:0% +T right because if if I know the + + + align:start position:0% +T right because if if I know the +locations but I don't know I'm not + + align:start position:0% +locations but I don't know I'm not + + + align:start position:0% +locations but I don't know I'm not +allowed to charge different prices and I + + align:start position:0% +allowed to charge different prices and I + + + align:start position:0% +allowed to charge different prices and I +just charge C plus T to + + align:start position:0% + + + + align:start position:0% + +everybody what's going to happen if I + + align:start position:0% +everybody what's going to happen if I + + + align:start position:0% +everybody what's going to happen if I +now start discriminating well if I'm + + align:start position:0% +now start discriminating well if I'm + + + align:start position:0% +now start discriminating well if I'm +firm one or let say I'm firm + + align:start position:0% +firm one or let say I'm firm + + + align:start position:0% +firm one or let say I'm firm +two and I'm trying to sell to a consumer + + align:start position:0% +two and I'm trying to sell to a consumer + + + align:start position:0% +two and I'm trying to sell to a consumer +over here I know that that consumer + + align:start position:0% +over here I know that that consumer + + + align:start position:0% +over here I know that that consumer +prefers firm one per firm one's product + + align:start position:0% +prefers firm one per firm one's product + + + align:start position:0% +prefers firm one per firm one's product +to my product and so to get that firm to + + align:start position:0% +to my product and so to get that firm to + + + align:start position:0% +to my product and so to get that firm to +get that consumer I'm going to have to + + align:start position:0% +get that consumer I'm going to have to + + + align:start position:0% +get that consumer I'm going to have to +undercut firm one + + align:start position:0% +undercut firm one + + + align:start position:0% +undercut firm one +um in pricing to this consumer there's + + align:start position:0% +um in pricing to this consumer there's + + + align:start position:0% +um in pricing to this consumer there's +no product differentiation left right we + + align:start position:0% +no product differentiation left right we + + + align:start position:0% +no product differentiation left right we +know this consumer has some value V1 for + + align:start position:0% +know this consumer has some value V1 for + + + align:start position:0% +know this consumer has some value V1 for +firm one's product and some value V2 for + + align:start position:0% +firm one's product and some value V2 for + + + align:start position:0% +firm one's product and some value V2 for +firm 2's product and we're just pricing + + align:start position:0% +firm 2's product and we're just pricing + + + align:start position:0% +firm 2's product and we're just pricing +to that consumer like in a beran + + align:start position:0% +to that consumer like in a beran + + + align:start position:0% +to that consumer like in a beran +competition model so what's going to + + align:start position:0% +competition model so what's going to + + + align:start position:0% +competition model so what's going to +happen is Bertrand competition is just + + align:start position:0% +happen is Bertrand competition is just + + + align:start position:0% +happen is Bertrand competition is just +going to force prices down until you + + align:start position:0% +going to force prices down until you + + + align:start position:0% +going to force prices down until you +know P2 + + align:start position:0% + + + + align:start position:0% + +star equals + + align:start position:0% +star equals + + + align:start position:0% +star equals +c and P1 star is going to be so P2 star + + align:start position:0% +c and P1 star is going to be so P2 star + + + align:start position:0% +c and P1 star is going to be so P2 star +of + + align:start position:0% +of + + + align:start position:0% +of +theta is C and P1 star of theta is going + + align:start position:0% +theta is C and P1 star of theta is going + + + align:start position:0% +theta is C and P1 star of theta is going +to be firm one's Advantage which + + align:start position:0% +to be firm one's Advantage which + + + align:start position:0% +to be firm one's Advantage which +isga Theta minus 1us + + align:start position:0% +isga Theta minus 1us + + + align:start position:0% +isga Theta minus 1us +Theta + + align:start position:0% + + + + align:start position:0% + +um m - 1us Theta so that's uh + + align:start position:0% +um m - 1us Theta so that's uh + + + align:start position:0% +um m - 1us Theta so that's uh +1us C+ so C plus 1 - 2 Theta so what + + align:start position:0% +1us C+ so C plus 1 - 2 Theta so what + + + align:start position:0% +1us C+ so C plus 1 - 2 Theta so what +firm one is going to do is firm one is + + align:start position:0% +firm one is going to do is firm one is + + + align:start position:0% +firm one is going to do is firm one is +going to price at its Advantage relative + + align:start position:0% +going to price at its Advantage relative + + + align:start position:0% +going to price at its Advantage relative +to firm two and the consumer is going to + + align:start position:0% +to firm two and the consumer is going to + + + align:start position:0% +to firm two and the consumer is going to +buy from firm + + align:start position:0% +buy from firm + + + align:start position:0% +buy from firm +one and so what you get if you over here + + align:start position:0% +one and so what you get if you over here + + + align:start position:0% +one and so what you get if you over here +I've tried to graph what is price + + align:start position:0% +I've tried to graph what is price + + + align:start position:0% +I've tried to graph what is price +equilibrium price paid as a function of + + align:start position:0% +equilibrium price paid as a function of + + + align:start position:0% +equilibrium price paid as a function of +theta and all these consumers over here + + align:start position:0% +theta and all these consumers over here + + + align:start position:0% +theta and all these consumers over here +hereby from firm one uh as you come to + + align:start position:0% +hereby from firm one uh as you come to + + + align:start position:0% +hereby from firm one uh as you come to +the middle of the line at the middle of + + align:start position:0% +the middle of the line at the middle of + + + align:start position:0% +the middle of the line at the middle of +the line they're in pure berr + + align:start position:0% +the line they're in pure berr + + + align:start position:0% +the line they're in pure berr +competition the consumer has the same + + align:start position:0% +competition the consumer has the same + + + align:start position:0% +competition the consumer has the same +preferences for both so they both price + + align:start position:0% +preferences for both so they both price + + + align:start position:0% +preferences for both so they both price +at C and then you go back up here to C + + align:start position:0% +at C and then you go back up here to C + + + align:start position:0% +at C and then you go back up here to C +plus T at the end so no discrimination + + align:start position:0% +plus T at the end so no discrimination + + + align:start position:0% +plus T at the end so no discrimination +everyone pays C plus + + align:start position:0% +everyone pays C plus + + + align:start position:0% +everyone pays C plus +t uh in with discrimination the worst + + align:start position:0% +t uh in with discrimination the worst + + + align:start position:0% +t uh in with discrimination the worst +case is you pay C plus T if if someone + + align:start position:0% +case is you pay C plus T if if someone + + + align:start position:0% +case is you pay C plus T if if someone +knows you're fully captive and like + + align:start position:0% +knows you're fully captive and like + + + align:start position:0% +knows you're fully captive and like +their product by T better and then + + align:start position:0% +their product by T better and then + + + align:start position:0% +their product by T better and then +otherwise you pay C in the + + align:start position:0% +otherwise you pay C in the + + + align:start position:0% +otherwise you pay C in the +middle okay so all the consumers are + + align:start position:0% +middle okay so all the consumers are + + + align:start position:0% +middle okay so all the consumers are +better off and they're better off + + align:start position:0% +better off and they're better off + + + align:start position:0% +better off and they're better off +because the rivals are cutting prices to + + align:start position:0% +because the rivals are cutting prices to + + + align:start position:0% +because the rivals are cutting prices to +Target consumers who don't want to buy + + align:start position:0% +Target consumers who don't want to buy + + + align:start position:0% +Target consumers who don't want to buy +from them and that targeting the rivals + + align:start position:0% +from them and that targeting the rivals + + + align:start position:0% +from them and that targeting the rivals +consumers is an intens allowing them to + + align:start position:0% +consumers is an intens allowing them to + + + align:start position:0% +consumers is an intens allowing them to +do that intensifies the competition and + + align:start position:0% +do that intensifies the competition and + + + align:start position:0% +do that intensifies the competition and +that intensifies competition Cuts prices + + align:start position:0% +that intensifies competition Cuts prices + + + align:start position:0% +that intensifies competition Cuts prices +for everybody so that's the sort of + + align:start position:0% +for everybody so that's the sort of + + + align:start position:0% +for everybody so that's the sort of +thought that price discrimination can be + + align:start position:0% +thought that price discrimination can be + + + align:start position:0% +thought that price discrimination can be +a universal good for + + align:start position:0% +a universal good for + + + align:start position:0% +a universal good for +consumers + + align:start position:0% +consumers + + + align:start position:0% +consumers +okay uh + + align:start position:0% +okay uh + + + align:start position:0% +okay uh +second insight though uh came uh you + + align:start position:0% +second insight though uh came uh you + + + align:start position:0% +second insight though uh came uh you +know uh Ken courts a decade later was + + align:start position:0% +know uh Ken courts a decade later was + + + align:start position:0% +know uh Ken courts a decade later was +that that's true but there's a second + + align:start position:0% +that that's true but there's a second + + + align:start position:0% +that that's true but there's a second +effect and price discrimination can + + align:start position:0% +effect and price discrimination can + + + align:start position:0% +effect and price discrimination can +actually make prices higher for all + + align:start position:0% +actually make prices higher for all + + + align:start position:0% +actually make prices higher for all +consumers and it's it's the thought that + + align:start position:0% +consumers and it's it's the thought that + + + align:start position:0% +consumers and it's it's the thought that +you know price discrimination makes your + + align:start position:0% +you know price discrimination makes your + + + align:start position:0% +you know price discrimination makes your +pricing more + + align:start position:0% +pricing more + + + align:start position:0% +pricing more +flexible one thing that lets you do is + + align:start position:0% +flexible one thing that lets you do is + + + align:start position:0% +flexible one thing that lets you do is +Target your Rivals consumers and that's + + align:start position:0% +Target your Rivals consumers and that's + + + align:start position:0% +Target your Rivals consumers and that's +good for competition the other thing it + + align:start position:0% +good for competition the other thing it + + + align:start position:0% +good for competition the other thing it +does is let you exploit people who are + + align:start position:0% +does is let you exploit people who are + + + align:start position:0% +does is let you exploit people who are +captive to you and so courts looked at + + align:start position:0% +captive to you and so courts looked at + + + align:start position:0% +captive to you and so courts looked at +this specification where if you think + + align:start position:0% +this specification where if you think + + + align:start position:0% +this specification where if you think +about it so over here what I've tried to + + align:start position:0% +about it so over here what I've tried to + + + align:start position:0% +about it so over here what I've tried to +graph is + + align:start position:0% +graph is + + + align:start position:0% +graph is +um uh you know what that's a graph of is + + align:start position:0% +um uh you know what that's a graph of is + + + align:start position:0% +um uh you know what that's a graph of is +what is uh + + align:start position:0% +what is uh + + + align:start position:0% +what is uh +V the value that you get for buying from + + align:start position:0% +V the value that you get for buying from + + + align:start position:0% +V the value that you get for buying from +firm Theta and what he assumes is that + + align:start position:0% +firm Theta and what he assumes is that + + + align:start position:0% +firm Theta and what he assumes is that +you get value two from buying from a + + align:start position:0% +you get value two from buying from a + + + align:start position:0% +you get value two from buying from a +consumer you know so these are uh value + + align:start position:0% +consumer you know so these are uh value + + + align:start position:0% +consumer you know so these are uh value +they get buying from firm + + align:start position:0% + + + + align:start position:0% + +one your value goes like this the + + align:start position:0% +one your value goes like this the + + + align:start position:0% +one your value goes like this the +farther your preferred type Theta is + + align:start position:0% +farther your preferred type Theta is + + + align:start position:0% +farther your preferred type Theta is +from firm one's product um the lower is + + align:start position:0% +from firm one's product um the lower is + + + align:start position:0% +from firm one's product um the lower is +the utility you get from + + align:start position:0% +the utility you get from + + + align:start position:0% +the utility you get from +it and then once the product is too far + + align:start position:0% +it and then once the product is too far + + + align:start position:0% +it and then once the product is too far +from what you want your utility just + + align:start position:0% +from what you want your utility just + + + align:start position:0% +from what you want your utility just +drops to zero like so I have this + + align:start position:0% +drops to zero like so I have this + + + align:start position:0% +drops to zero like so I have this +decreasing you know distance from firm + + align:start position:0% +decreasing you know distance from firm + + + align:start position:0% +decreasing you know distance from firm +one I like it less and less and then + + align:start position:0% +one I like it less and less and then + + + align:start position:0% +one I like it less and less and then +once it gets to some point I'm like I + + align:start position:0% +once it gets to some point I'm like I + + + align:start position:0% +once it gets to some point I'm like I +can't use that and then your utility + + align:start position:0% +can't use that and then your utility + + + align:start position:0% +can't use that and then your utility +drops to zero so that's my utility + + align:start position:0% +drops to zero so that's my utility + + + align:start position:0% +drops to zero so that's my utility +buying from firm one + + align:start position:0% +buying from firm one + + + align:start position:0% +buying from firm one +and my utility buying from firm two does + + align:start position:0% +and my utility buying from firm two does + + + align:start position:0% +and my utility buying from firm two does +the opposite it's zero here and then it + + align:start position:0% +the opposite it's zero here and then it + + + align:start position:0% +the opposite it's zero here and then it +goes up like that so these high Theta + + align:start position:0% +goes up like that so these high Theta + + + align:start position:0% +goes up like that so these high Theta +consumers really like and get utility + + align:start position:0% +consumers really like and get utility + + + align:start position:0% +consumers really like and get utility +two from buying from one's product the + + align:start position:0% +two from buying from one's product the + + + align:start position:0% +two from buying from one's product the +guy in the middle gets utility one from + + align:start position:0% +guy in the middle gets utility one from + + + align:start position:0% +guy in the middle gets utility one from +both and vice versa so in some sense + + align:start position:0% +both and vice versa so in some sense + + + align:start position:0% +both and vice versa so in some sense +I've eliminated that targeting your + + align:start position:0% +I've eliminated that targeting your + + + align:start position:0% +I've eliminated that targeting your +Rivals uh competitors effect by saying + + align:start position:0% +Rivals uh competitors effect by saying + + + align:start position:0% +Rivals uh competitors effect by saying +that anyone who gets utility from one + + align:start position:0% +that anyone who gets utility from one + + + align:start position:0% +that anyone who gets utility from one +firm gets zero utility from the other + + align:start position:0% +firm gets zero utility from the other + + + align:start position:0% +firm gets zero utility from the other +firm so letting them Target your rivals + + align:start position:0% +firm so letting them Target your rivals + + + align:start position:0% +firm so letting them Target your rivals +consumers doesn't actually create any + + align:start position:0% +consumers doesn't actually create any + + + align:start position:0% +consumers doesn't actually create any +competition um so you know what would + + align:start position:0% +competition um so you know what would + + + align:start position:0% +competition um so you know what would +happen in this + + align:start position:0% +happen in this + + + align:start position:0% +happen in this +model um in this model if I ban + + align:start position:0% +model um in this model if I ban + + + align:start position:0% +model um in this model if I ban +competition if I ban price + + align:start position:0% +competition if I ban price + + + align:start position:0% +competition if I ban price +discrimination sorry if I ban price + + align:start position:0% +discrimination sorry if I ban price + + + align:start position:0% +discrimination sorry if I ban price +discrimination firm one is essentially + + align:start position:0% +discrimination firm one is essentially + + + align:start position:0% +discrimination firm one is essentially +pricing as if it had a linear demand + + align:start position:0% +pricing as if it had a linear demand + + + align:start position:0% +pricing as if it had a linear demand +curve you know it's a linear demand + + align:start position:0% +curve you know it's a linear demand + + + align:start position:0% +curve you know it's a linear demand +curve that cuts off but if you remember + + align:start position:0% +curve that cuts off but if you remember + + + align:start position:0% +curve that cuts off but if you remember +if you have a linear demand curve that + + align:start position:0% +if you have a linear demand curve that + + + align:start position:0% +if you have a linear demand curve that +looks like this even if it continues you + + align:start position:0% +looks like this even if it continues you + + + align:start position:0% +looks like this even if it continues you +still would price at + + align:start position:0% +still would price at + + + align:start position:0% +still would price at +one so with + + align:start position:0% +one so with + + + align:start position:0% +one so with +if you ban price discrimination firm one + + align:start position:0% +if you ban price discrimination firm one + + + align:start position:0% +if you ban price discrimination firm one +is going to set P star equals one firm + + align:start position:0% +is going to set P star equals one firm + + + align:start position:0% +is going to set P star equals one firm +two is going to set P star equals one + + align:start position:0% +two is going to set P star equals one + + + align:start position:0% +two is going to set P star equals one +because they're both just pricing to the + + align:start position:0% +because they're both just pricing to the + + + align:start position:0% +because they're both just pricing to the +linear demand curve 2 minus + + align:start position:0% +linear demand curve 2 minus + + + align:start position:0% +linear demand curve 2 minus +P whereas if you allow them to + + align:start position:0% +P whereas if you allow them to + + + align:start position:0% +P whereas if you allow them to +discriminate I do first-degree price + + align:start position:0% +discriminate I do first-degree price + + + align:start position:0% +discriminate I do first-degree price +discrimination this guy pays two this + + align:start position:0% +discrimination this guy pays two this + + + align:start position:0% +discrimination this guy pays two this +guy pays 1.9 this guy pays 1.8 and so on + + align:start position:0% +guy pays 1.9 this guy pays 1.8 and so on + + + align:start position:0% +guy pays 1.9 this guy pays 1.8 and so on +till this guy pays one so basically I + + align:start position:0% +till this guy pays one so basically I + + + align:start position:0% +till this guy pays one so basically I +just raise prices to everyone because + + align:start position:0% +just raise prices to everyone because + + + align:start position:0% +just raise prices to everyone because +letting me price discriminate lets me + + align:start position:0% +letting me price discriminate lets me + + + align:start position:0% +letting me price discriminate lets me +exploit all of lets me extract all of + + align:start position:0% +exploit all of lets me extract all of + + + align:start position:0% +exploit all of lets me extract all of +their Surplus when I don't have + + align:start position:0% +their Surplus when I don't have + + + align:start position:0% +their Surplus when I don't have +competition and here I've designed the + + align:start position:0% +competition and here I've designed the + + + align:start position:0% +competition and here I've designed the +oligopoly so there really isn't any + + align:start position:0% +oligopoly so there really isn't any + + + align:start position:0% +oligopoly so there really isn't any +competition so you know I think courts' + + align:start position:0% +competition so you know I think courts' + + + align:start position:0% +competition so you know I think courts' +basic Insight was that there are these + + align:start position:0% +basic Insight was that there are these + + + align:start position:0% +basic Insight was that there are these +two effects and we shouldn't necessarily + + align:start position:0% +two effects and we shouldn't necessarily + + + align:start position:0% +two effects and we shouldn't necessarily +expect either of those two effects to + + align:start position:0% +expect either of those two effects to + + + align:start position:0% +expect either of those two effects to +dominate you know price discrimination + + align:start position:0% +dominate you know price discrimination + + + align:start position:0% +dominate you know price discrimination +can be good because it intensifies + + align:start position:0% +can be good because it intensifies + + + align:start position:0% +can be good because it intensifies +competition it can be bad because it has + + align:start position:0% +competition it can be bad because it has + + + align:start position:0% +competition it can be bad because it has +more exploitation and it's just going to + + align:start position:0% +more exploitation and it's just going to + + + align:start position:0% +more exploitation and it's just going to +matter on the distribution of relative + + align:start position:0% +matter on the distribution of relative + + + align:start position:0% +matter on the distribution of relative +preferences for firm one versus firm 2's + + align:start position:0% +preferences for firm one versus firm 2's + + + align:start position:0% +preferences for firm one versus firm 2's +products whether the exploitation effect + + align:start position:0% +products whether the exploitation effect + + + align:start position:0% +products whether the exploitation effect +dominates and makes prices go up or the + + align:start position:0% +dominates and makes prices go up or the + + + align:start position:0% +dominates and makes prices go up or the +the competition effect dominates and + + align:start position:0% +the competition effect dominates and + + + align:start position:0% +the competition effect dominates and +makes prices go down um as I said you + + align:start position:0% +makes prices go down um as I said you + + + align:start position:0% +makes prices go down um as I said you +know like right the this hoteling model + + align:start position:0% +know like right the this hoteling model + + + align:start position:0% +know like right the this hoteling model +it's like it's an intermediate effect + + align:start position:0% +it's like it's an intermediate effect + + + align:start position:0% +it's like it's an intermediate effect +it's like you charge intermediate prices + + align:start position:0% +it's like you charge intermediate prices + + + align:start position:0% +it's like you charge intermediate prices +and you know you're lose the ability to + + align:start position:0% +and you know you're lose the ability to + + + align:start position:0% +and you know you're lose the ability to +compete and discriminate in a way that + + align:start position:0% +compete and discriminate in a way that + + + align:start position:0% +compete and discriminate in a way that +makes you just sort of charge something + + align:start position:0% +makes you just sort of charge something + + + align:start position:0% +makes you just sort of charge something +in between what you would have charged + + align:start position:0% +in between what you would have charged + + + align:start position:0% +in between what you would have charged +the high and low types + + align:start position:0% +the high and low types + + + align:start position:0% +the high and low types +um + + align:start position:0% +um + + + align:start position:0% +um +okay any questions on that argument yeah + + align:start position:0% +okay any questions on that argument yeah + + + align:start position:0% +okay any questions on that argument yeah +is it this just kind of arguing that if + + align:start position:0% +is it this just kind of arguing that if + + + align:start position:0% +is it this just kind of arguing that if +it's not action oligopoly monopoly yeah + + align:start position:0% +it's not action oligopoly monopoly yeah + + + align:start position:0% +it's not action oligopoly monopoly yeah +that's right it so he he made it a + + align:start position:0% +that's right it so he he made it a + + + align:start position:0% +that's right it so he he made it a +monopoly so it's but then obviously like + + align:start position:0% +monopoly so it's but then obviously like + + + align:start position:0% +monopoly so it's but then obviously like +you could have it be an oligopoly like + + align:start position:0% +you could have it be an oligopoly like + + + align:start position:0% +you could have it be an oligopoly like +this and you would get the same results + + align:start position:0% +this and you would get the same results + + + align:start position:0% +this and you would get the same results +right like if it was an oligopoly where + + align:start position:0% +right like if it was an oligopoly where + + + align:start position:0% +right like if it was an oligopoly where +it really was an oligopoly but most of + + align:start position:0% +it really was an oligopoly but most of + + + align:start position:0% +it really was an oligopoly but most of +them got low utility from one and high + + align:start position:0% +them got low utility from one and high + + + align:start position:0% +them got low utility from one and high +from the other then you would still get + + align:start position:0% +from the other then you would still get + + + align:start position:0% +from the other then you would still get +the same effect there but it it's yeah + + align:start position:0% +the same effect there but it it's yeah + + + align:start position:0% +the same effect there but it it's yeah +he's arguing that it's basically it's + + align:start position:0% +he's arguing that it's basically it's + + + align:start position:0% +he's arguing that it's basically it's +adjacent to the Monopoly model and in + + align:start position:0% +adjacent to the Monopoly model and in + + + align:start position:0% +adjacent to the Monopoly model and in +the Monopoly model it goes this way so + + align:start position:0% +the Monopoly model it goes this way so + + + align:start position:0% +the Monopoly model it goes this way so +oligopoly models near that one it's + + align:start position:0% +oligopoly models near that one it's + + + align:start position:0% +oligopoly models near that one it's +going to go the same way + + align:start position:0% + + + + align:start position:0% + +yeah okay um so that that was sort of + + align:start position:0% +yeah okay um so that that was sort of + + + align:start position:0% +yeah okay um so that that was sort of +oligopoly third degree price + + align:start position:0% +oligopoly third degree price + + + align:start position:0% +oligopoly third degree price +discrimination what about second degree + + align:start position:0% +discrimination what about second degree + + + align:start position:0% +discrimination what about second degree +price discrimination and I do think that + + align:start position:0% +price discrimination and I do think that + + + align:start position:0% +price discrimination and I do think that +you know oligopoly second degree price + + align:start position:0% +you know oligopoly second degree price + + + align:start position:0% +you know oligopoly second degree price +discrimination is a really important + + align:start position:0% +discrimination is a really important + + + align:start position:0% +discrimination is a really important +topic because you know I think many many + + align:start position:0% +topic because you know I think many many + + + align:start position:0% +topic because you know I think many many +products people + + align:start position:0% +products people + + + align:start position:0% +products people +buy there is second degree + + align:start position:0% +buy there is second degree + + + align:start position:0% +buy there is second degree +discrimination there like you know + + align:start position:0% +discrimination there like you know + + + align:start position:0% +discrimination there like you know +you're buying phones there is the iPhone + + align:start position:0% +you're buying phones there is the iPhone + + + align:start position:0% +you're buying phones there is the iPhone +13 and the iPhone 14 and the 128 + + align:start position:0% +13 and the iPhone 14 and the 128 + + + align:start position:0% +13 and the iPhone 14 and the 128 +megabyte and the 512 megabyte version + + align:start position:0% +megabyte and the 512 megabyte version + + + align:start position:0% +megabyte and the 512 megabyte version +you know you're buying cable TV and it's + + align:start position:0% +you know you're buying cable TV and it's + + + align:start position:0% +you know you're buying cable TV and it's +cable TV package one package two package + + align:start position:0% +cable TV package one package two package + + + align:start position:0% +cable TV package one package two package +three package four all with increasing + + align:start position:0% +three package four all with increasing + + + align:start position:0% +three package four all with increasing +features you know you have competing + + align:start position:0% +features you know you have competing + + + align:start position:0% +features you know you have competing +firm selling TVs everyone's got the you + + align:start position:0% +firm selling TVs everyone's got the you + + + align:start position:0% +firm selling TVs everyone's got the you +know 42in TV and the 49 in TV and the 55 + + align:start position:0% +know 42in TV and the 49 in TV and the 55 + + + align:start position:0% +know 42in TV and the 49 in TV and the 55 +in TV and the 62in TV and each of those + + align:start position:0% +in TV and the 62in TV and each of those + + + align:start position:0% +in TV and the 62in TV and each of those +TVs has the 4K or doesn't have the 4K + + align:start position:0% +TVs has the 4K or doesn't have the 4K + + + align:start position:0% +TVs has the 4K or doesn't have the 4K +but it's you know you generally see + + align:start position:0% +but it's you know you generally see + + + align:start position:0% +but it's you know you generally see +firms in olop Industries are selling + + align:start position:0% +firms in olop Industries are selling + + + align:start position:0% +firms in olop Industries are selling +multiple products competing with + + align:start position:0% +multiple products competing with + + + align:start position:0% +multiple products competing with +multiple products of each other + + align:start position:0% +multiple products of each other + + + align:start position:0% +multiple products of each other +um you know so if you're talking about + + align:start position:0% +um you know so if you're talking about + + + align:start position:0% +um you know so if you're talking about +oligopoly second degree discrimination + + align:start position:0% +oligopoly second degree discrimination + + + align:start position:0% +oligopoly second degree discrimination +or the the cars in breaston hand's + + align:start position:0% +or the the cars in breaston hand's + + + align:start position:0% +or the the cars in breaston hand's +example right like it's Ford is + + align:start position:0% +example right like it's Ford is + + + align:start position:0% +example right like it's Ford is +producing a line of cards GM is + + align:start position:0% +producing a line of cards GM is + + + align:start position:0% +producing a line of cards GM is +producing a line of cars those cars are + + align:start position:0% +producing a line of cars those cars are + + + align:start position:0% +producing a line of cars those cars are +competing against other models and + + align:start position:0% +competing against other models and + + + align:start position:0% +competing against other models and +there's sort of vertical constraints + + align:start position:0% +there's sort of vertical constraints + + + align:start position:0% +there's sort of vertical constraints +within the firm and there's also + + align:start position:0% +within the firm and there's also + + + align:start position:0% +within the firm and there's also +competition across the firms um so you + + align:start position:0% +competition across the firms um so you + + + align:start position:0% +competition across the firms um so you +know clearly you want to have vertical + + align:start position:0% +know clearly you want to have vertical + + + align:start position:0% +know clearly you want to have vertical +differentiation and you want to have + + align:start position:0% +differentiation and you want to have + + + align:start position:0% +differentiation and you want to have +horizontal different + + align:start position:0% +horizontal different + + + align:start position:0% +horizontal different +iation and then the substitution + + align:start position:0% +iation and then the substitution + + + align:start position:0% +iation and then the substitution +patterns there's going to be cross firm + + align:start position:0% +patterns there's going to be cross firm + + + align:start position:0% +patterns there's going to be cross firm +substitution going on and there's going + + align:start position:0% +substitution going on and there's going + + + align:start position:0% +substitution going on and there's going +to be within firm substitution going on + + align:start position:0% +to be within firm substitution going on + + + align:start position:0% +to be within firm substitution going on +and it just turns out it's hard to write + + align:start position:0% +and it just turns out it's hard to write + + + align:start position:0% +and it just turns out it's hard to write +down a nice tractable model that has you + + align:start position:0% +down a nice tractable model that has you + + + align:start position:0% +down a nice tractable model that has you +know the two dimensions of consumer + + align:start position:0% +know the two dimensions of consumer + + + align:start position:0% +know the two dimensions of consumer +tastes and has both substitution + + align:start position:0% +tastes and has both substitution + + + align:start position:0% +tastes and has both substitution +patterns mattering in the sort of + + align:start position:0% +patterns mattering in the sort of + + + align:start position:0% +patterns mattering in the sort of +binding IC constraints and The Binding + + align:start position:0% +binding IC constraints and The Binding + + + align:start position:0% +binding IC constraints and The Binding +cross firm constraints um so what the + + align:start position:0% +cross firm constraints um so what the + + + align:start position:0% +cross firm constraints um so what the +literatures tend to do is is do a few + + align:start position:0% +literatures tend to do is is do a few + + + align:start position:0% +literatures tend to do is is do a few +different special cases one thing it's + + align:start position:0% +different special cases one thing it's + + + align:start position:0% +different special cases one thing it's +done is to assume independent horizontal + + align:start position:0% +done is to assume independent horizontal + + + align:start position:0% +done is to assume independent horizontal +and vertical preferences and there's + + align:start position:0% +and vertical preferences and there's + + + align:start position:0% +and vertical preferences and there's +this observation that if you make + + align:start position:0% +this observation that if you make + + + align:start position:0% +this observation that if you make +horizontal and vertical preferences + + align:start position:0% +horizontal and vertical preferences + + + align:start position:0% +horizontal and vertical preferences +independent you get a surprisingly + + align:start position:0% +independent you get a surprisingly + + + align:start position:0% +independent you get a surprisingly +tractable model that you can do even + + align:start position:0% +tractable model that you can do even + + + align:start position:0% +tractable model that you can do even +with a Continuum of types um the other + + align:start position:0% +with a Continuum of types um the other + + + align:start position:0% +with a Continuum of types um the other +thing that people do is have discrete + + align:start position:0% +thing that people do is have discrete + + + align:start position:0% +thing that people do is have discrete +vertical types and when you have + + align:start position:0% +vertical types and when you have + + + align:start position:0% +vertical types and when you have +discrete vertical types um you can + + align:start position:0% +discrete vertical types um you can + + + align:start position:0% +discrete vertical types um you can +sometimes make the IC constraints the + + align:start position:0% +sometimes make the IC constraints the + + + align:start position:0% +sometimes make the IC constraints the +within firm IC constraints non-binding + + align:start position:0% +within firm IC constraints non-binding + + + align:start position:0% +within firm IC constraints non-binding +and eliminate the number of constraints + + align:start position:0% +and eliminate the number of constraints + + + align:start position:0% +and eliminate the number of constraints +you have to solve for um and then a + + align:start position:0% +you have to solve for um and then a + + + align:start position:0% +you have to solve for um and then a +third approach you sometimes see people + + align:start position:0% +third approach you sometimes see people + + + align:start position:0% +third approach you sometimes see people +do is actually just eliminate the + + align:start position:0% +do is actually just eliminate the + + + align:start position:0% +do is actually just eliminate the +vertical differentiation entirely and + + align:start position:0% +vertical differentiation entirely and + + + align:start position:0% +vertical differentiation entirely and +talk about uh second degree + + align:start position:0% +talk about uh second degree + + + align:start position:0% +talk about uh second degree +discrimination in a model that doesn't + + align:start position:0% +discrimination in a model that doesn't + + + align:start position:0% +discrimination in a model that doesn't +have vertical uh + + align:start position:0% +have vertical uh + + + align:start position:0% +have vertical uh +differentiation + + align:start position:0% +differentiation + + + align:start position:0% +differentiation +um okay so let me go I'll start with + + align:start position:0% +um okay so let me go I'll start with + + + align:start position:0% +um okay so let me go I'll start with +just + + align:start position:0% +just + + + align:start position:0% +just +a you know overview of what happens in + + align:start position:0% +a you know overview of what happens in + + + align:start position:0% +a you know overview of what happens in +this independent model so um you know + + align:start position:0% +this independent model so um you know + + + align:start position:0% +this independent model so um you know +stole has a chapter of the handbook in + + align:start position:0% +stole has a chapter of the handbook in + + + align:start position:0% +stole has a chapter of the handbook in +IO that surveys this literature that's + + align:start position:0% +IO that surveys this literature that's + + + align:start position:0% +IO that surveys this literature that's +pretty big + + align:start position:0% +pretty big + + + align:start position:0% +pretty big +um and seemingly General you have these + + align:start position:0% +um and seemingly General you have these + + + align:start position:0% +um and seemingly General you have these +firms J they can produce a range of + + align:start position:0% +firms J they can produce a range of + + + align:start position:0% +firms J they can produce a range of +qualities s at some constant marginal + + align:start position:0% +qualities s at some constant marginal + + + align:start position:0% +qualities s at some constant marginal +cost C of s so typically they actually + + align:start position:0% +cost C of s so typically they actually + + + align:start position:0% +cost C of s so typically they actually +have a Continuum of s's they could + + align:start position:0% +have a Continuum of s's they could + + + align:start position:0% +have a Continuum of s's they could +produce if they wanted to uh consumer + + align:start position:0% +produce if they wanted to uh consumer + + + align:start position:0% +produce if they wanted to uh consumer +eyes utility from buying a good of + + align:start position:0% +eyes utility from buying a good of + + + align:start position:0% +eyes utility from buying a good of +quality s from firm J is Theta I of s so + + align:start position:0% +quality s from firm J is Theta I of s so + + + align:start position:0% +quality s from firm J is Theta I of s so +this is the vertical preference High + + align:start position:0% +this is the vertical preference High + + + align:start position:0% +this is the vertical preference High +types like are willing to pay more for + + align:start position:0% +types like are willing to pay more for + + + align:start position:0% +types like are willing to pay more for +Quality minus the price plus the epon i + + align:start position:0% +Quality minus the price plus the epon i + + + align:start position:0% +Quality minus the price plus the epon i +j so this is the logit like error um + + align:start position:0% +j so this is the logit like error um + + + align:start position:0% +j so this is the logit like error um +that we've had in our + + align:start position:0% +that we've had in our + + + align:start position:0% +that we've had in our +models and then models assume that the + + align:start position:0% +models and then models assume that the + + + align:start position:0% +models and then models assume that the +Theta I and the Epsilon I JS are all + + align:start position:0% +Theta I and the Epsilon I JS are all + + + align:start position:0% +Theta I and the Epsilon I JS are all +independent and Theta I is distributed F + + align:start position:0% +independent and Theta I is distributed F + + + align:start position:0% +independent and Theta I is distributed F +Theta Epsilon i j is dist distributed F + + align:start position:0% +Theta Epsilon i j is dist distributed F + + + align:start position:0% +Theta Epsilon i j is dist distributed F +Epsilon and they're pretty General in + + align:start position:0% +Epsilon and they're pretty General in + + + align:start position:0% +Epsilon and they're pretty General in +terms of what distribution of theta is + + align:start position:0% +terms of what distribution of theta is + + + align:start position:0% +terms of what distribution of theta is +in what distribution of epsilons you + + align:start position:0% +in what distribution of epsilons you + + + align:start position:0% +in what distribution of epsilons you +have + + align:start position:0% +have + + + align:start position:0% +have +okay so let me Define SAR of theta to be + + align:start position:0% +okay so let me Define SAR of theta to be + + + align:start position:0% +okay so let me Define SAR of theta to be +the efficient quality for a consumer uh + + align:start position:0% +the efficient quality for a consumer uh + + + align:start position:0% +the efficient quality for a consumer uh +of type uh that should say type Theta to + + align:start position:0% +of type uh that should say type Theta to + + + align:start position:0% +of type uh that should say type Theta to +buy so you have a consumer this should + + align:start position:0% +buy so you have a consumer this should + + + align:start position:0% +buy so you have a consumer this should +be a Theta instead of a v so you know if + + align:start position:0% +be a Theta instead of a v so you know if + + + align:start position:0% +be a Theta instead of a v so you know if +you have a type Theta consumer they + + align:start position:0% +you have a type Theta consumer they + + + align:start position:0% +you have a type Theta consumer they +ought to be buying quality the maximize + + align:start position:0% +ought to be buying quality the maximize + + + align:start position:0% +ought to be buying quality the maximize +is Theta Time s minus C of s so this is + + align:start position:0% +is Theta Time s minus C of s so this is + + + align:start position:0% +is Theta Time s minus C of s so this is +if the goods were sold at Cost what + + align:start position:0% +if the goods were sold at Cost what + + + align:start position:0% +if the goods were sold at Cost what +would they buy that's the efficient + + align:start position:0% +would they buy that's the efficient + + + align:start position:0% +would they buy that's the efficient +thing to sell to them + + align:start position:0% +thing to sell to them + + + align:start position:0% +thing to sell to them +okay um so just an example of a for of a + + align:start position:0% +okay um so just an example of a for of a + + + align:start position:0% +okay um so just an example of a for of a +model fitting this consider a hoteling + + align:start position:0% +model fitting this consider a hoteling + + + align:start position:0% +model fitting this consider a hoteling +like model and suppose that Epsilon i1 + + align:start position:0% +like model and suppose that Epsilon i1 + + + align:start position:0% +like model and suppose that Epsilon i1 +is distributed uniform on 0 to T and + + align:start position:0% +is distributed uniform on 0 to T and + + + align:start position:0% +is distributed uniform on 0 to T and +Epsilon I2 is is just the negative of + + align:start position:0% +Epsilon I2 is is just the negative of + + + align:start position:0% +Epsilon I2 is is just the negative of +Epsilon + + align:start position:0% + + + + align:start position:0% + +one then a nashy equ that model is just + + align:start position:0% +one then a nashy equ that model is just + + + align:start position:0% +one then a nashy equ that model is just +PJs is C of S Plus t for all J and S so + + align:start position:0% +PJs is C of S Plus t for all J and S so + + + align:start position:0% +PJs is C of S Plus t for all J and S so +if you imagine it it's as if we've got + + align:start position:0% +if you imagine it it's as if we've got + + + align:start position:0% +if you imagine it it's as if we've got +this uh you know + + align:start position:0% +this uh you know + + + align:start position:0% +this uh you know +I've got this Continuum of hotelling + + align:start position:0% + + + + align:start position:0% + +lines so you have these different + + align:start position:0% +lines so you have these different + + + align:start position:0% +lines so you have these different +quality levels S1 S2 S3 S4 + + align:start position:0% + + + + align:start position:0% + +S5 on each line let's imagine I charge + + align:start position:0% +S5 on each line let's imagine I charge + + + align:start position:0% +S5 on each line let's imagine I charge +uh P star equals c of + + align:start position:0% +uh P star equals c of + + + align:start position:0% +uh P star equals c of +s so quality of you know + + align:start position:0% +s so quality of you know + + + align:start position:0% +s so quality of you know +yeah price for Quality s is C of S Plus + + align:start position:0% +yeah price for Quality s is C of S Plus + + + align:start position:0% +yeah price for Quality s is C of S Plus +t Okay so imagine you had that + + align:start position:0% +t Okay so imagine you had that + + + align:start position:0% +t Okay so imagine you had that +pricing that every every quality I sell + + align:start position:0% +pricing that every every quality I sell + + + align:start position:0% +pricing that every every quality I sell +at the Cost Plus T then what are + + align:start position:0% +at the Cost Plus T then what are + + + align:start position:0% +at the Cost Plus T then what are +consumers going to do you know the + + align:start position:0% +consumers going to do you know the + + + align:start position:0% +consumers going to do you know the +markups are the same for every quality + + align:start position:0% +markups are the same for every quality + + + align:start position:0% +markups are the same for every quality +level so when I'm deciding which quality + + align:start position:0% +level so when I'm deciding which quality + + + align:start position:0% +level so when I'm deciding which quality +level to buy I buy the efficient quality + + align:start position:0% +level to buy I buy the efficient quality + + + align:start position:0% +level to buy I buy the efficient quality +level I buy s if I'm a type Theta + + align:start position:0% +level I buy s if I'm a type Theta + + + align:start position:0% +level I buy s if I'm a type Theta +consumer I buy SAR of theta + + align:start position:0% +consumer I buy SAR of theta + + + align:start position:0% +consumer I buy SAR of theta +so all the consumers for whom S3 is the + + align:start position:0% +so all the consumers for whom S3 is the + + + align:start position:0% +so all the consumers for whom S3 is the +optimal quality are like okay I'm either + + align:start position:0% +optimal quality are like okay I'm either + + + align:start position:0% +optimal quality are like okay I'm either +going to + + align:start position:0% + + + + align:start position:0% + +buy quality S3 from firm one or I'm + + align:start position:0% +buy quality S3 from firm one or I'm + + + align:start position:0% +buy quality S3 from firm one or I'm +going to buy quality 3 from S2 who do I + + align:start position:0% +going to buy quality 3 from S2 who do I + + + align:start position:0% +going to buy quality 3 from S2 who do I +buy from well again it depends on my it + + align:start position:0% +buy from well again it depends on my it + + + align:start position:0% +buy from well again it depends on my it +depends on my now I'm calling this an + + align:start position:0% +depends on my now I'm calling this an + + + align:start position:0% +depends on my now I'm calling this an +Epsilon i1 and an Epsilon + + align:start position:0% +Epsilon i1 and an Epsilon + + + align:start position:0% +Epsilon i1 and an Epsilon +I2 + + align:start position:0% +I2 + + + align:start position:0% +I2 +but if I if my taste is I really like + + align:start position:0% +but if I if my taste is I really like + + + align:start position:0% +but if I if my taste is I really like +firm one's product I buy from firm one + + align:start position:0% +firm one's product I buy from firm one + + + align:start position:0% +firm one's product I buy from firm one +if my Epsilon is I really buy firm two's + + align:start position:0% +if my Epsilon is I really buy firm two's + + + align:start position:0% +if my Epsilon is I really buy firm two's +product I buy from firm two and so it's + + align:start position:0% +product I buy from firm two and so it's + + + align:start position:0% +product I buy from firm two and so it's +just the you know like as far as if the + + align:start position:0% +just the you know like as far as if the + + + align:start position:0% +just the you know like as far as if the +firm Cuts its price it's just like the + + align:start position:0% +firm Cuts its price it's just like the + + + align:start position:0% +firm Cuts its price it's just like the +competition on a line model and if it + + align:start position:0% +competition on a line model and if it + + + align:start position:0% +competition on a line model and if it +cuts its price it will attract you know + + align:start position:0% +cuts its price it will attract you know + + + align:start position:0% +cuts its price it will attract you know +more consumers from the other side it + + align:start position:0% +more consumers from the other side it + + + align:start position:0% +more consumers from the other side it +would have you know this increase in + + align:start position:0% +would have you know this increase in + + + align:start position:0% +would have you know this increase in +demand one half plus P2 minus P1 over + + align:start position:0% +demand one half plus P2 minus P1 over + + + align:start position:0% +demand one half plus P2 minus P1 over +2T but they're just basically competing + + align:start position:0% +2T but they're just basically competing + + + align:start position:0% +2T but they're just basically competing +on a line against the other firm for + + align:start position:0% +on a line against the other firm for + + + align:start position:0% +on a line against the other firm for +this quality level and so the same + + align:start position:0% +this quality level and so the same + + + align:start position:0% +this quality level and so the same +hoteling First St condition applies and + + align:start position:0% +hoteling First St condition applies and + + + align:start position:0% +hoteling First St condition applies and +they chart price C plus t on each line + + align:start position:0% +they chart price C plus t on each line + + + align:start position:0% +they chart price C plus t on each line +and so if the firms are doing this + + align:start position:0% +and so if the firms are doing this + + + align:start position:0% +and so if the firms are doing this +they're playing hotelling on each line + + align:start position:0% +they're playing hotelling on each line + + + align:start position:0% +they're playing hotelling on each line +they're pricing at C plus t on each line + + align:start position:0% +they're pricing at C plus t on each line + + + align:start position:0% +they're pricing at C plus t on each line +all consumers do buy the best quality + + align:start position:0% +all consumers do buy the best quality + + + align:start position:0% +all consumers do buy the best quality +for them and so the result here is that + + align:start position:0% +for them and so the result here is that + + + align:start position:0% +for them and so the result here is that +when you have competitive secondary + + align:start position:0% +when you have competitive secondary + + + align:start position:0% +when you have competitive secondary +discrimination secondary discrimination + + align:start position:0% +discrimination secondary discrimination + + + align:start position:0% +discrimination secondary discrimination +goes away the firms are not using + + align:start position:0% +goes away the firms are not using + + + align:start position:0% +goes away the firms are not using +different quality levels to discriminate + + align:start position:0% +different quality levels to discriminate + + + align:start position:0% +different quality levels to discriminate +among consumers they just are charging + + align:start position:0% +among consumers they just are charging + + + align:start position:0% +among consumers they just are charging +you know it's not like the iPhone with + + align:start position:0% +you know it's not like the iPhone with + + + align:start position:0% +you know it's not like the iPhone with +512 megabytes cost $300 more than the + + align:start position:0% +512 megabytes cost $300 more than the + + + align:start position:0% +512 megabytes cost $300 more than the +iPhone with 128 megabytes + + align:start position:0% +iPhone with 128 megabytes + + + align:start position:0% +iPhone with 128 megabytes +they give them all at the same markup + + align:start position:0% +they give them all at the same markup + + + align:start position:0% +they give them all at the same markup +and all consumers buy the efficient + + align:start position:0% +and all consumers buy the efficient + + + align:start position:0% +and all consumers buy the efficient +quality so all of that quality + + align:start position:0% +quality so all of that quality + + + align:start position:0% +quality so all of that quality +distortions second in secondary + + align:start position:0% +distortions second in secondary + + + align:start position:0% +distortions second in secondary +discrimination goes + + align:start position:0% + + + + align:start position:0% + +away okay um and you know I I sort of + + align:start position:0% +away okay um and you know I I sort of + + + align:start position:0% +away okay um and you know I I sort of +gave this example in the hoteling model + + align:start position:0% +gave this example in the hoteling model + + + align:start position:0% +gave this example in the hoteling model +but you know stall shows that this is + + align:start position:0% +but you know stall shows that this is + + + align:start position:0% +but you know stall shows that this is +really very general so there's this very + + align:start position:0% +really very general so there's this very + + + align:start position:0% +really very general so there's this very +general thing of for F's distribut of + + align:start position:0% +general thing of for F's distribut of + + + align:start position:0% +general thing of for F's distribut of +Epsilon satisfying some conditions + + align:start position:0% +Epsilon satisfying some conditions + + + align:start position:0% +Epsilon satisfying some conditions +industries of Epsilon satisfying some + + align:start position:0% +industries of Epsilon satisfying some + + + align:start position:0% +industries of Epsilon satisfying some +conditions as long as the Theta and + + align:start position:0% +conditions as long as the Theta and + + + align:start position:0% +conditions as long as the Theta and +Epsilon are are independent this always + + align:start position:0% +Epsilon are are independent this always + + + align:start position:0% +Epsilon are are independent this always +happens you just get competition on many + + align:start position:0% +happens you just get competition on many + + + align:start position:0% +happens you just get competition on many +lines and constant markups across + + align:start position:0% +lines and constant markups across + + + align:start position:0% +lines and constant markups across +Goods um and I I think the thing that I + + align:start position:0% +Goods um and I I think the thing that I + + + align:start position:0% +Goods um and I I think the thing that I +want to most point out most about this + + align:start position:0% +want to most point out most about this + + + align:start position:0% +want to most point out most about this +model is that it seems very general but + + align:start position:0% +model is that it seems very general but + + + align:start position:0% +model is that it seems very general but +it's got this hidden special and + + align:start position:0% +it's got this hidden special and + + + align:start position:0% +it's got this hidden special and +incorrect assumption in it which is that + + align:start position:0% +incorrect assumption in it which is that + + + align:start position:0% +incorrect assumption in it which is that +the thetas and the epsilons are going to + + align:start position:0% +the thetas and the epsilons are going to + + + align:start position:0% +the thetas and the epsilons are going to +be uh + + align:start position:0% +be uh + + + align:start position:0% +be uh +independent okay and I you know a good + + align:start position:0% +independent okay and I you know a good + + + align:start position:0% +independent okay and I you know a good +example to think about this is you know + + align:start position:0% +example to think about this is you know + + + align:start position:0% +example to think about this is you know +think about um uh think about you and uh + + align:start position:0% +think about um uh think about you and uh + + + align:start position:0% +think about um uh think about you and uh +a CEO of some company flying to Europe + + align:start position:0% +a CEO of some company flying to Europe + + + align:start position:0% +a CEO of some company flying to Europe +and you're told that there are two + + align:start position:0% +and you're told that there are two + + + align:start position:0% +and you're told that there are two +flights available to go to Paris there's + + align:start position:0% +flights available to go to Paris there's + + + align:start position:0% +flights available to go to Paris there's +a Delta flight or an Air France flight + + align:start position:0% +a Delta flight or an Air France flight + + + align:start position:0% +a Delta flight or an Air France flight +okay um you know you might say that sort + + align:start position:0% +okay um you know you might say that sort + + + align:start position:0% +okay um you know you might say that sort +of you know some people like Air France + + align:start position:0% +of you know some people like Air France + + + align:start position:0% +of you know some people like Air France +better than Delta some people like de + + align:start position:0% +better than Delta some people like de + + + align:start position:0% +better than Delta some people like de +Delta better than Air France um you know + + align:start position:0% +Delta better than Air France um you know + + + align:start position:0% +Delta better than Air France um you know +it may be that the preferences that + + align:start position:0% +it may be that the preferences that + + + align:start position:0% +it may be that the preferences that +students have on Delta versus Air France + + align:start position:0% +students have on Delta versus Air France + + + align:start position:0% +students have on Delta versus Air France +and the preferences that the CEOs have + + align:start position:0% +and the preferences that the CEOs have + + + align:start position:0% +and the preferences that the CEOs have +on Delta versus Air France are + + align:start position:0% +on Delta versus Air France are + + + align:start position:0% +on Delta versus Air France are +uncorrelated that yeah they're both like + + align:start position:0% +uncorrelated that yeah they're both like + + + align:start position:0% +uncorrelated that yeah they're both like +you can model them as uniform on zero to + + align:start position:0% +you can model them as uniform on zero to + + + align:start position:0% +you can model them as uniform on zero to +T for their dis utility for Air France + + align:start position:0% +T for their dis utility for Air France + + + align:start position:0% +T for their dis utility for Air France +relative their ideal Airline disly for + + align:start position:0% +relative their ideal Airline disly for + + + align:start position:0% +relative their ideal Airline disly for +Delta but what's uncorrelated as + + align:start position:0% +Delta but what's uncorrelated as + + + align:start position:0% +Delta but what's uncorrelated as +reasonable independent is not reasonable + + align:start position:0% +reasonable independent is not reasonable + + + align:start position:0% +reasonable independent is not reasonable +because how much are you willing to pay + + align:start position:0% +because how much are you willing to pay + + + align:start position:0% +because how much are you willing to pay +those of you who really like Air France + + align:start position:0% +those of you who really like Air France + + + align:start position:0% +those of you who really like Air France +how much extra are you willing to pay + + align:start position:0% +how much extra are you willing to pay + + + align:start position:0% +how much extra are you willing to pay +for to go to on Air France maybe it's 20 + + align:start position:0% +for to go to on Air France maybe it's 20 + + + align:start position:0% +for to go to on Air France maybe it's 20 +bucks maybe it's 10 bucks I don't know + + align:start position:0% +bucks maybe it's 10 bucks I don't know + + + align:start position:0% +bucks maybe it's 10 bucks I don't know +um the CEOs they may pay $5,000 more to + + align:start position:0% +um the CEOs they may pay $5,000 more to + + + align:start position:0% +um the CEOs they may pay $5,000 more to +go on Air France relative to Delta if + + align:start position:0% +go on Air France relative to Delta if + + + align:start position:0% +go on Air France relative to Delta if +they like it because for them the 5,000 + + align:start position:0% +they like it because for them the 5,000 + + + align:start position:0% +they like it because for them the 5,000 +is sort of rounding error and so you + + align:start position:0% +is sort of rounding error and so you + + + align:start position:0% +is sort of rounding error and so you +know I think what's reasonable there is + + align:start position:0% +know I think what's reasonable there is + + + align:start position:0% +know I think what's reasonable there is +the uncorrelated preferences for you + + align:start position:0% +the uncorrelated preferences for you + + + align:start position:0% +the uncorrelated preferences for you +know that the businessmen and the + + align:start position:0% +know that the businessmen and the + + + align:start position:0% +know that the businessmen and the +students may have the same + + align:start position:0% + + + + align:start position:0% + +well same you know uncorrelated + + align:start position:0% +well same you know uncorrelated + + + align:start position:0% +well same you know uncorrelated +preferences for Del you know this for + + align:start position:0% +preferences for Del you know this for + + + align:start position:0% +preferences for Del you know this for +Delta versus Air France but they + + align:start position:0% +Delta versus Air France but they + + + align:start position:0% +Delta versus Air France but they +wouldn't have independent preferences + + align:start position:0% +wouldn't have independent preferences + + + align:start position:0% +wouldn't have independent preferences +what it really might look like is you + + align:start position:0% +what it really might look like is you + + + align:start position:0% +what it really might look like is you +know you'd have the student + + align:start position:0% +know you'd have the student + + + align:start position:0% +know you'd have the student +line uh you have the student line + + align:start position:0% +line uh you have the student line + + + align:start position:0% +line uh you have the student line +where T is very small and then you have + + align:start position:0% +where T is very small and then you have + + + align:start position:0% +where T is very small and then you have +the uh businessman line where T is very + + align:start position:0% +the uh businessman line where T is very + + + align:start position:0% +the uh businessman line where T is very +very big + + align:start position:0% +very big + + + align:start position:0% +very big +you know they have a higher vertical + + align:start position:0% +you know they have a higher vertical + + + align:start position:0% +you know they have a higher vertical +willingness to pay for the good but then + + align:start position:0% +willingness to pay for the good but then + + + align:start position:0% +willingness to pay for the good but then +having in addition to higher vertical + + align:start position:0% +having in addition to higher vertical + + + align:start position:0% +having in addition to higher vertical +willingness to pay they just have much + + align:start position:0% +willingness to pay they just have much + + + align:start position:0% +willingness to pay they just have much +more + + align:start position:0% +more + + + align:start position:0% +more +intense horizontal preferences as + + align:start position:0% +intense horizontal preferences as + + + align:start position:0% +intense horizontal preferences as +measured in dollars that's not covered + + align:start position:0% +measured in dollars that's not covered + + + align:start position:0% +measured in dollars that's not covered +by the independence + + align:start position:0% +by the independence + + + align:start position:0% +by the independence +case Independence would say there should + + align:start position:0% +case Independence would say there should + + + align:start position:0% +case Independence would say there should +be one line up here like this where + + align:start position:0% +be one line up here like this where + + + align:start position:0% +be one line up here like this where +again they'll all shift from Air France + + align:start position:0% +again they'll all shift from Air France + + + align:start position:0% +again they'll all shift from Air France +to Delta for 20 bucks which is just not + + align:start position:0% +to Delta for 20 bucks which is just not + + + align:start position:0% +to Delta for 20 bucks which is just not +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +true + + align:start position:0% +true + + + align:start position:0% +true +okay and it's the + + align:start position:0% +okay and it's the + + + align:start position:0% +okay and it's the +independence in some sense that results + + align:start position:0% +independence in some sense that results + + + align:start position:0% +independence in some sense that results +in the constant + + align:start position:0% +in the constant + + + align:start position:0% +in the constant +markups so you know second op so a + + align:start position:0% +markups so you know second op so a + + + align:start position:0% +markups so you know second op so a +second way people model this is just + + align:start position:0% +second way people model this is just + + + align:start position:0% +second way people model this is just +let's go with this discrete type space + + align:start position:0% +let's go with this discrete type space + + + align:start position:0% +let's go with this discrete type space +so there's just you know two + + align:start position:0% +so there's just you know two + + + align:start position:0% +so there's just you know two +qualities um SL and Sh SL is the coach + + align:start position:0% +qualities um SL and Sh SL is the coach + + + align:start position:0% +qualities um SL and Sh SL is the coach +class seat where your knees are pressed + + align:start position:0% +class seat where your knees are pressed + + + align:start position:0% +class seat where your knees are pressed +into the seat in front of you and then + + align:start position:0% +into the seat in front of you and then + + + align:start position:0% +into the seat in front of you and then +sh is the LI flat bed with the nice TV + + align:start position:0% +sh is the LI flat bed with the nice TV + + + align:start position:0% +sh is the LI flat bed with the nice TV +and the champagne and glasses when you + + align:start position:0% +and the champagne and glasses when you + + + align:start position:0% +and the champagne and glasses when you +walk on the plane and everything else + + align:start position:0% +walk on the plane and everything else + + + align:start position:0% +walk on the plane and everything else +okay and so what you can think of here + + align:start position:0% +okay and so what you can think of here + + + align:start position:0% +okay and so what you can think of here +is you know model this is I can model + + align:start position:0% +is you know model this is I can model + + + align:start position:0% +is you know model this is I can model +that as the uh vertical differentiation + + align:start position:0% +that as the uh vertical differentiation + + + align:start position:0% +that as the uh vertical differentiation +model where consumers have a discrete + + align:start position:0% +model where consumers have a discrete + + + align:start position:0% +model where consumers have a discrete +vertical type TL or + + align:start position:0% +vertical type TL or + + + align:start position:0% +vertical type TL or +th and then they have horizontal types + + align:start position:0% +th and then they have horizontal types + + + align:start position:0% +th and then they have horizontal types +Epsilon i1 and Epsilon I2 just like in + + align:start position:0% +Epsilon i1 and Epsilon I2 just like in + + + align:start position:0% +Epsilon i1 and Epsilon I2 just like in +the hoteling model and let's instead + + align:start position:0% +the hoteling model and let's instead + + + align:start position:0% +the hoteling model and let's instead +then specify the utility instead of + + align:start position:0% +then specify the utility instead of + + + align:start position:0% +then specify the utility instead of +being Theta S Plus EP minus P plus + + align:start position:0% +being Theta S Plus EP minus P plus + + + align:start position:0% +being Theta S Plus EP minus P plus +Epsilon we'll M have the Theta multiply + + align:start position:0% +Epsilon we'll M have the Theta multiply + + + align:start position:0% +Epsilon we'll M have the Theta multiply +s minus + + align:start position:0% +s minus + + + align:start position:0% +s minus +Epsilon so that if you have you know + + align:start position:0% +Epsilon so that if you have you know + + + align:start position:0% +Epsilon so that if you have you know +everybody has in has + + align:start position:0% +everybody has in has + + + align:start position:0% +everybody has in has +um uh everyone has horizontal + + align:start position:0% +um uh everyone has horizontal + + + align:start position:0% +um uh everyone has horizontal +preferences of the same intensity in + + align:start position:0% +preferences of the same intensity in + + + align:start position:0% +preferences of the same intensity in +utils but when you convert the utils to + + align:start position:0% +utils but when you convert the utils to + + + align:start position:0% +utils but when you convert the utils to +Dollars by multiplying by this Theta the + + align:start position:0% +Dollars by multiplying by this Theta the + + + align:start position:0% +Dollars by multiplying by this Theta the +preferences in dollar terms are much + + align:start position:0% +preferences in dollar terms are much + + + align:start position:0% +preferences in dollar terms are much +more intense for the businessmen than + + align:start position:0% +more intense for the businessmen than + + + align:start position:0% +more intense for the businessmen than +they are for the students so the Theta + + align:start position:0% +they are for the students so the Theta + + + align:start position:0% +they are for the students so the Theta +the vertical + + align:start position:0% +the vertical + + + align:start position:0% +the vertical +type multiplies both the quality and the + + align:start position:0% +type multiplies both the quality and the + + + align:start position:0% +type multiplies both the quality and the +relative preference of Delta Air + + align:start position:0% +relative preference of Delta Air + + + align:start position:0% +relative preference of Delta Air +France okay so in this model it's + + align:start position:0% +France okay so in this model it's + + + align:start position:0% +France okay so in this model it's +reasonable to assume that the thetas and + + align:start position:0% +reasonable to assume that the thetas and + + + align:start position:0% +reasonable to assume that the thetas and +the epsilons are now independent so you + + align:start position:0% +the epsilons are now independent so you + + + align:start position:0% +the epsilons are now independent so you +have this willingness to pay for Quality + + align:start position:0% +have this willingness to pay for Quality + + + align:start position:0% +have this willingness to pay for Quality +um whether it be quality of the the nice + + align:start position:0% +um whether it be quality of the the nice + + + align:start position:0% +um whether it be quality of the the nice +seed or quality of the Air France food + + align:start position:0% +seed or quality of the Air France food + + + align:start position:0% +seed or quality of the Air France food +and then you have a idiosyncratic taste + + align:start position:0% +and then you have a idiosyncratic taste + + + align:start position:0% +and then you have a idiosyncratic taste +for the Air France food versus the Delta + + align:start position:0% +for the Air France food versus the Delta + + + align:start position:0% +for the Air France food versus the Delta +food okay uh anyway so I'm going to + + align:start position:0% +food okay uh anyway so I'm going to + + + align:start position:0% +food okay uh anyway so I'm going to +assume for this numerical example that + + align:start position:0% +assume for this numerical example that + + + align:start position:0% +assume for this numerical example that +the thetas and the epsilons are + + align:start position:0% +the thetas and the epsilons are + + + align:start position:0% +the thetas and the epsilons are +independent and half the people are high + + align:start position:0% +independent and half the people are high + + + align:start position:0% +independent and half the people are high +types um so what happens here well you + + align:start position:0% +types um so what happens here well you + + + align:start position:0% +types um so what happens here well you +know simple fact I got conditions under + + align:start position:0% +know simple fact I got conditions under + + + align:start position:0% +know simple fact I got conditions under +which this is true but under some set of + + align:start position:0% +which this is true but under some set of + + + align:start position:0% +which this is true but under some set of +conditions what you get is you know if + + align:start position:0% +conditions what you get is you know if + + + align:start position:0% +conditions what you get is you know if +this is a line that has length TL and + + align:start position:0% +this is a line that has length TL and + + + align:start position:0% +this is a line that has length TL and +this is a line that has length uh + + align:start position:0% +this is a line that has length uh + + + align:start position:0% +this is a line that has length uh +th you get P star equals c plus TL + + align:start position:0% +th you get P star equals c plus TL + + + align:start position:0% +th you get P star equals c plus TL +here and you get P star equals c plus th + + align:start position:0% +here and you get P star equals c plus th + + + align:start position:0% +here and you get P star equals c plus th +here all right so on the big line you + + align:start position:0% +here all right so on the big line you + + + align:start position:0% +here all right so on the big line you +price with with the big amount of + + align:start position:0% +price with with the big amount of + + + align:start position:0% +price with with the big amount of +differentiation on the little line you + + align:start position:0% +differentiation on the little line you + + + align:start position:0% +differentiation on the little line you +price in the little amount of + + align:start position:0% +price in the little amount of + + + align:start position:0% +price in the little amount of +differentiation and all the low types by + + align:start position:0% +differentiation and all the low types by + + + align:start position:0% +differentiation and all the low types by +the low quality product all the high + + align:start position:0% +the low quality product all the high + + + align:start position:0% +the low quality product all the high +types by the high quality product what + + align:start position:0% +types by the high quality product what + + + align:start position:0% +types by the high quality product what +has to be true for that you know it has + + align:start position:0% +has to be true for that you know it has + + + align:start position:0% +has to be true for that you know it has +to be that the th times uh Delta s is + + align:start position:0% +to be that the th times uh Delta s is + + + align:start position:0% +to be that the th times uh Delta s is +the willingness to pay of high types to + + align:start position:0% +the willingness to pay of high types to + + + align:start position:0% +the willingness to pay of high types to +get the high quality product TL Delta s + + align:start position:0% +get the high quality product TL Delta s + + + align:start position:0% +get the high quality product TL Delta s +is the willingness to pay of the low + + align:start position:0% +is the willingness to pay of the low + + + align:start position:0% +is the willingness to pay of the low +types to get the high quality product + + align:start position:0% +types to get the high quality product + + + align:start position:0% +types to get the high quality product +and it just has to be + + align:start position:0% +and it just has to be + + + align:start position:0% +and it just has to be +that the markups that result from + + align:start position:0% +that the markups that result from + + + align:start position:0% +that the markups that result from +different uh differenti different + + align:start position:0% +different uh differenti different + + + align:start position:0% +different uh differenti different +degrees of differentiation + + align:start position:0% +degrees of differentiation + + + align:start position:0% +degrees of differentiation +are exactly between the willingness to + + align:start position:0% +are exactly between the willingness to + + + align:start position:0% +are exactly between the willingness to +pay the high types and the low types so + + align:start position:0% +pay the high types and the low types so + + + align:start position:0% +pay the high types and the low types so +here you know just in this under those + + align:start position:0% +here you know just in this under those + + + align:start position:0% +here you know just in this under those +assumptions the IC constraints are all + + align:start position:0% +assumptions the IC constraints are all + + + align:start position:0% +assumptions the IC constraints are all +non-binding you know there are no + + align:start position:0% +non-binding you know there are no + + + align:start position:0% +non-binding you know there are no +consumers who are indifferent between + + align:start position:0% +consumers who are indifferent between + + + align:start position:0% +consumers who are indifferent between +buying a first class ticket or a coach + + align:start position:0% +buying a first class ticket or a coach + + + align:start position:0% +buying a first class ticket or a coach +class ticket in this model I've written + + align:start position:0% +class ticket in this model I've written + + + align:start position:0% +class ticket in this model I've written +down there are the sort of students are + + align:start position:0% +down there are the sort of students are + + + align:start position:0% +down there are the sort of students are +are just in competition on align to buy + + align:start position:0% +are just in competition on align to buy + + + align:start position:0% +are just in competition on align to buy +the low class tickets these are kind of + + align:start position:0% +the low class tickets these are kind of + + + align:start position:0% +the low class tickets these are kind of +by the high cost tickets it requires a + + align:start position:0% +by the high cost tickets it requires a + + + align:start position:0% +by the high cost tickets it requires a +coincidence right The Coincidence is + + align:start position:0% +coincidence right The Coincidence is + + + align:start position:0% +coincidence right The Coincidence is +that + + align:start position:0% +that + + + align:start position:0% +that +th minus TL is in this range that makes + + align:start position:0% +th minus TL is in this range that makes + + + align:start position:0% +th minus TL is in this range that makes +both of the IC constraints non-binding + + align:start position:0% +both of the IC constraints non-binding + + + align:start position:0% +both of the IC constraints non-binding +and makes the businessman buy the + + align:start position:0% +and makes the businessman buy the + + + align:start position:0% +and makes the businessman buy the +business class tickets the students buy + + align:start position:0% +business class tickets the students buy + + + align:start position:0% +business class tickets the students buy +this the the coach class + + align:start position:0% +this the the coach class + + + align:start position:0% +this the the coach class +tickets um but you know this is a I + + align:start position:0% +tickets um but you know this is a I + + + align:start position:0% +tickets um but you know this is a I +don't know this is a perfectly + + align:start position:0% +don't know this is a perfectly + + + align:start position:0% +don't know this is a perfectly +reasonable model of secondary oligopoly + + align:start position:0% +reasonable model of secondary oligopoly + + + align:start position:0% +reasonable model of secondary oligopoly +price discrimination you know again it + + align:start position:0% +price discrimination you know again it + + + align:start position:0% +price discrimination you know again it +does say that competition determines + + align:start position:0% +does say that competition determines + + + align:start position:0% +does say that competition determines +markups so it is a very different + + align:start position:0% +markups so it is a very different + + + align:start position:0% +markups so it is a very different +mathematical structure from what you get + + align:start position:0% +mathematical structure from what you get + + + align:start position:0% +mathematical structure from what you get +in the um uh it's a different + + align:start position:0% +in the um uh it's a different + + + align:start position:0% +in the um uh it's a different +mathematical structure from what you get + + align:start position:0% +mathematical structure from what you get + + + align:start position:0% +mathematical structure from what you get +in the + + align:start position:0% +in the + + + align:start position:0% +in the +um uh second degree Monopoly price + + align:start position:0% +um uh second degree Monopoly price + + + align:start position:0% +um uh second degree Monopoly price +discrimination model where it's the IC + + align:start position:0% +discrimination model where it's the IC + + + align:start position:0% +discrimination model where it's the IC +constraints and the manipulating quality + + align:start position:0% +constraints and the manipulating quality + + + align:start position:0% +constraints and the manipulating quality +to do things um you know it it is the + + align:start position:0% +to do things um you know it it is the + + + align:start position:0% +to do things um you know it it is the +case that you can still get you can + + align:start position:0% +case that you can still get you can + + + align:start position:0% +case that you can still get you can +think of you can get + + align:start position:0% +think of you can get + + + align:start position:0% +think of you can get +um you know I set these sh and SL + + align:start position:0% +um you know I set these sh and SL + + + align:start position:0% +um you know I set these sh and SL +exogenous it could be that you can get + + align:start position:0% +exogenous it could be that you can get + + + align:start position:0% +exogenous it could be that you can get +sort of manipulation of the qualities + + align:start position:0% +sort of manipulation of the qualities + + + align:start position:0% +sort of manipulation of the qualities +here where firms charge an choose a + + align:start position:0% +here where firms charge an choose a + + + align:start position:0% +here where firms charge an choose a +quality level SL that prevents the + + align:start position:0% +quality level SL that prevents the + + + align:start position:0% +quality level SL that prevents the +businessmen from take you know some + + align:start position:0% +businessmen from take you know some + + + align:start position:0% +businessmen from take you know some +sense they choose how far apart to make + + align:start position:0% +sense they choose how far apart to make + + + align:start position:0% +sense they choose how far apart to make +these lines so that this price + + align:start position:0% +these lines so that this price + + + align:start position:0% +these lines so that this price +discrimination scheme holds up um you + + align:start position:0% +discrimination scheme holds up um you + + + align:start position:0% +discrimination scheme holds up um you +know if if SL were too high I increase + + align:start position:0% +know if if SL were too high I increase + + + align:start position:0% +know if if SL were too high I increase +SL at some point the IR constraint would + + align:start position:0% +SL at some point the IR constraint would + + + align:start position:0% +SL at some point the IR constraint would +start binding and the high types would + + align:start position:0% +start binding and the high types would + + + align:start position:0% +start binding and the high types would +jump down and start buying the low + + align:start position:0% +jump down and start buying the low + + + align:start position:0% +jump down and start buying the low +quality B uh good + + align:start position:0% +quality B uh good + + + align:start position:0% +quality B uh good +instead + + align:start position:0% + + + + align:start position:0% + +okay okay and we say you know + + align:start position:0% +okay okay and we say you know + + + align:start position:0% +okay okay and we say you know +interesting about this model is this + + align:start position:0% +interesting about this model is this + + + align:start position:0% +interesting about this model is this +model is also a model of multiple + + align:start position:0% +model is also a model of multiple + + + align:start position:0% +model is also a model of multiple +equilib + + align:start position:0% +equilib + + + align:start position:0% +equilib +sometimes this model has two equilibria + + align:start position:0% +sometimes this model has two equilibria + + + align:start position:0% +sometimes this model has two equilibria +one where the firms discriminate and one + + align:start position:0% +one where the firms discriminate and one + + + align:start position:0% +one where the firms discriminate and one +where the firms just sell the high + + align:start position:0% +where the firms just sell the high + + + align:start position:0% +where the firms just sell the high +quality good to everybody and in some + + align:start position:0% +quality good to everybody and in some + + + align:start position:0% +quality good to everybody and in some +sense there's this just this + + align:start position:0% +sense there's this just this + + + align:start position:0% +sense there's this just this +complimentarity if you're you know right + + align:start position:0% +complimentarity if you're you know right + + + align:start position:0% +complimentarity if you're you know right +we we know these things have upward + + align:start position:0% +we we know these things have upward + + + align:start position:0% +we we know these things have upward +sloping reaction functions where you try + + align:start position:0% +sloping reaction functions where you try + + + align:start position:0% +sloping reaction functions where you try +tend to sort of you know you only go one + + align:start position:0% +tend to sort of you know you only go one + + + align:start position:0% +tend to sort of you know you only go one +half to one but like you know as your + + align:start position:0% +half to one but like you know as your + + + align:start position:0% +half to one but like you know as your +rival raises their price you raise your + + align:start position:0% +rival raises their price you raise your + + + align:start position:0% +rival raises their price you raise your +price that same thing means if your + + align:start position:0% +price that same thing means if your + + + align:start position:0% +price that same thing means if your +rival is spreading its prices for the + + align:start position:0% +rival is spreading its prices for the + + + align:start position:0% +rival is spreading its prices for the +high and low quality good apart you want + + align:start position:0% +high and low quality good apart you want + + + align:start position:0% +high and low quality good apart you want +to spread your prices apart + + align:start position:0% +to spread your prices apart + + + align:start position:0% +to spread your prices apart +but you can actually have two equilibria + + align:start position:0% +but you can actually have two equilibria + + + align:start position:0% +but you can actually have two equilibria +one where the lowquality good doesn't + + align:start position:0% +one where the lowquality good doesn't + + + align:start position:0% +one where the lowquality good doesn't +exist in the F they just compete for + + align:start position:0% +exist in the F they just compete for + + + align:start position:0% +exist in the F they just compete for +everybody with selling the high quality + + align:start position:0% +everybody with selling the high quality + + + align:start position:0% +everybody with selling the high quality +good and then the other where this + + align:start position:0% +good and then the other where this + + + align:start position:0% +good and then the other where this +discrimination + + align:start position:0% +discrimination + + + align:start position:0% +discrimination +occurs okay but the discriminatory + + align:start position:0% +occurs okay but the discriminatory + + + align:start position:0% +occurs okay but the discriminatory +equilibrium is better for the firms than + + align:start position:0% +equilibrium is better for the firms than + + + align:start position:0% +equilibrium is better for the firms than +the one where they don't + + align:start position:0% + + + + align:start position:0% + +discriminate okay any questions on that + + align:start position:0% + + + + align:start position:0% + +model okay so then the final Theory + + align:start position:0% +model okay so then the final Theory + + + align:start position:0% +model okay so then the final Theory +topic I wanted to get to us a little bit + + align:start position:0% +topic I wanted to get to us a little bit + + + align:start position:0% +topic I wanted to get to us a little bit +on um add-on pricing um so but first let + + align:start position:0% +on um add-on pricing um so but first let + + + align:start position:0% +on um add-on pricing um so but first let +me go back to uh laen matuda uh Journal + + align:start position:0% +me go back to uh laen matuda uh Journal + + + align:start position:0% +me go back to uh laen matuda uh Journal +business + + align:start position:0% +business + + + align:start position:0% +business + + align:start position:0% + + + align:start position:0% +um you know LA and mudas were thinking + + align:start position:0% +um you know LA and mudas were thinking + + + align:start position:0% +um you know LA and mudas were thinking +of this question of you + + align:start position:0% +of this question of you + + + align:start position:0% +of this question of you +know why is it that turkeys are on sale + + align:start position:0% +know why is it that turkeys are on sale + + + align:start position:0% +know why is it that turkeys are on sale +on Thanksgiving wouldn't you think that + + align:start position:0% +on Thanksgiving wouldn't you think that + + + align:start position:0% +on Thanksgiving wouldn't you think that +the one day of the year when turkey + + align:start position:0% +the one day of the year when turkey + + + align:start position:0% +the one day of the year when turkey +demand is a hundred times higher than it + + align:start position:0% +demand is a hundred times higher than it + + + align:start position:0% +demand is a hundred times higher than it +is any other day of the year turkey + + align:start position:0% +is any other day of the year turkey + + + align:start position:0% +is any other day of the year turkey +prices would be high instead of low um + + align:start position:0% +prices would be high instead of low um + + + align:start position:0% +prices would be high instead of low um +and let's think about the following + + align:start position:0% +and let's think about the following + + + align:start position:0% +and let's think about the following +model so suppose and you know think of + + align:start position:0% +model so suppose and you know think of + + + align:start position:0% +model so suppose and you know think of +this as a model of people competing you + + align:start position:0% +this as a model of people competing you + + + align:start position:0% +this as a model of people competing you +know uh this is competing + + align:start position:0% +know uh this is competing + + + align:start position:0% +know uh this is competing +supermarkets um and the supermarkets are + + align:start position:0% +supermarkets um and the supermarkets are + + + align:start position:0% +supermarkets um and the supermarkets are +selling two different products um V1 and + + align:start position:0% +selling two different products um V1 and + + + align:start position:0% +selling two different products um V1 and +V2 and consumers actually all want to + + align:start position:0% +V2 and consumers actually all want to + + + align:start position:0% +V2 and consumers actually all want to +buy both products they want to buy the + + align:start position:0% +buy both products they want to buy the + + + align:start position:0% +buy both products they want to buy the +the turkey and they want to buy the + + align:start position:0% +the turkey and they want to buy the + + + align:start position:0% +the turkey and they want to buy the +stuffing or the cranberry sauce sauce or + + align:start position:0% +stuffing or the cranberry sauce sauce or + + + align:start position:0% +stuffing or the cranberry sauce sauce or +whatever um and so what my utility is I + + align:start position:0% +whatever um and so what my utility is I + + + align:start position:0% +whatever um and so what my utility is I +get V1 + V2 minus P11 - p12 minus t + + align:start position:0% +get V1 + V2 minus P11 - p12 minus t + + + align:start position:0% +get V1 + V2 minus P11 - p12 minus t +Theta if I am type Theta and I drive to + + align:start position:0% +Theta if I am type Theta and I drive to + + + align:start position:0% +Theta if I am type Theta and I drive to +store one and I buy both products there + + align:start position:0% +store one and I buy both products there + + + align:start position:0% +store one and I buy both products there +are at these + + align:start position:0% +are at these + + + align:start position:0% +are at these +prices or I can go to firm drive to firm + + align:start position:0% +prices or I can go to firm drive to firm + + + align:start position:0% +prices or I can go to firm drive to firm +two and again get V1 minus p21 plus V2 + + align:start position:0% +two and again get V1 minus p21 plus V2 + + + align:start position:0% +two and again get V1 minus p21 plus V2 +minus P22 minus t * 1 minus Theta if I + + align:start position:0% +minus P22 minus t * 1 minus Theta if I + + + align:start position:0% +minus P22 minus t * 1 minus Theta if I +drive and buy the products from firm two + + align:start position:0% +drive and buy the products from firm two + + + align:start position:0% +drive and buy the products from firm two +and then I can if I want um split my + + align:start position:0% +and then I can if I want um split my + + + align:start position:0% +and then I can if I want um split my +shopping and get V1 minus P11 by buying + + align:start position:0% +shopping and get V1 minus P11 by buying + + + align:start position:0% +shopping and get V1 minus P11 by buying +the turkey at store one and then get V2 + + align:start position:0% +the turkey at store one and then get V2 + + + align:start position:0% +the turkey at store one and then get V2 +minus P22 from buying the cranberry + + align:start position:0% +minus P22 from buying the cranberry + + + align:start position:0% +minus P22 from buying the cranberry +sauce at firm two but then I have + + align:start position:0% +sauce at firm two but then I have + + + align:start position:0% +sauce at firm two but then I have +incurred both driving + + align:start position:0% +incurred both driving + + + align:start position:0% +incurred both driving +costs uh and so while in matuda consider + + align:start position:0% +costs uh and so while in matuda consider + + + align:start position:0% +costs uh and so while in matuda consider +this multi-stage game where what firms + + align:start position:0% +this multi-stage game where what firms + + + align:start position:0% +this multi-stage game where what firms +do is you know imagine there were per + + align:start position:0% +do is you know imagine there were per + + + align:start position:0% +do is you know imagine there were per +product advertising costs so you don't + + align:start position:0% +product advertising costs so you don't + + + align:start position:0% +product advertising costs so you don't +want to advertise the price of every + + align:start position:0% +want to advertise the price of every + + + align:start position:0% +want to advertise the price of every +product in your store that's clearly + + align:start position:0% +product in your store that's clearly + + + align:start position:0% +product in your store that's clearly +true with supermarkets you you've got + + align:start position:0% +true with supermarkets you you've got + + + align:start position:0% +true with supermarkets you you've got +10,000 products there you can't + + align:start position:0% +10,000 products there you can't + + + align:start position:0% +10,000 products there you can't +advertise all of them so in the extreme + + align:start position:0% +advertise all of them so in the extreme + + + align:start position:0% +advertise all of them so in the extreme +case suppose you choose an advertise the + + align:start position:0% +case suppose you choose an advertise the + + + align:start position:0% +case suppose you choose an advertise the +price of one + + align:start position:0% +price of one + + + align:start position:0% +price of one +good and then after choosing the price + + align:start position:0% +good and then after choosing the price + + + align:start position:0% +good and then after choosing the price +of your one good you choose an + + align:start position:0% +of your one good you choose an + + + align:start position:0% +of your one good you choose an +unadvertised price for the other good + + align:start position:0% +unadvertised price for the other good + + + align:start position:0% +unadvertised price for the other good +which is kept secret until consumers + + align:start position:0% +which is kept secret until consumers + + + align:start position:0% +which is kept secret until consumers +arrive at the + + align:start position:0% +arrive at the + + + align:start position:0% +arrive at the +store consumers drive to one firm and + + align:start position:0% +store consumers drive to one firm and + + + align:start position:0% +store consumers drive to one firm and +current cost either T Theta or T1 minus + + align:start position:0% +current cost either T Theta or T1 minus + + + align:start position:0% +current cost either T Theta or T1 minus +Theta when they get there they learn the + + align:start position:0% +Theta when they get there they learn the + + + align:start position:0% +Theta when they get there they learn the +price for the unver IED good and then + + align:start position:0% +price for the unver IED good and then + + + align:start position:0% +price for the unver IED good and then +consumers after learning the price of + + align:start position:0% +consumers after learning the price of + + + align:start position:0% +consumers after learning the price of +the unadvertised good they either buy + + align:start position:0% +the unadvertised good they either buy + + + align:start position:0% +the unadvertised good they either buy +one or both products there or they + + align:start position:0% +one or both products there or they + + + align:start position:0% +one or both products there or they +decide to drive to the other firm and + + align:start position:0% +decide to drive to the other firm and + + + align:start position:0% +decide to drive to the other firm and +buy at the at firm two + + align:start position:0% +buy at the at firm two + + + align:start position:0% +buy at the at firm two +instead + + align:start position:0% +instead + + + align:start position:0% +instead +okay you know proposition first um in + + align:start position:0% +okay you know proposition first um in + + + align:start position:0% +okay you know proposition first um in +the above model equilibrium prices + + align:start position:0% +the above model equilibrium prices + + + align:start position:0% +the above model equilibrium prices +satisfy P1 Star Plus P2 star is C1 plus + + align:start position:0% +satisfy P1 Star Plus P2 star is C1 plus + + + align:start position:0% +satisfy P1 Star Plus P2 star is C1 plus +C2 plus T again this is just the + + align:start position:0% +C2 plus T again this is just the + + + align:start position:0% +C2 plus T again this is just the +hoteling competition on a line model uh + + align:start position:0% +hoteling competition on a line model uh + + + align:start position:0% +hoteling competition on a line model uh +in equilibrium the price of the bundle + + align:start position:0% +in equilibrium the price of the bundle + + + align:start position:0% +in equilibrium the price of the bundle +is going to be C plus + + align:start position:0% + + + + align:start position:0% + +T um but the individual prices are not + + align:start position:0% +T um but the individual prices are not + + + align:start position:0% +T um but the individual prices are not +like C plus t over2 for each the + + align:start position:0% +like C plus t over2 for each the + + + align:start position:0% +like C plus t over2 for each the +individual prices are P two star equals + + align:start position:0% +individual prices are P two star equals + + + align:start position:0% +individual prices are P two star equals +V2 and pj1 star is C1 plus C2 plus T + + align:start position:0% +V2 and pj1 star is C1 plus C2 plus T + + + align:start position:0% +V2 and pj1 star is C1 plus C2 plus T +minus V2 so + + align:start position:0% +minus V2 so + + + align:start position:0% +minus V2 so +basically uh cranberry sauce is always + + align:start position:0% +basically uh cranberry sauce is always + + + align:start position:0% +basically uh cranberry sauce is always +incredibly expensive on Thanksgiving you + + align:start position:0% +incredibly expensive on Thanksgiving you + + + align:start position:0% +incredibly expensive on Thanksgiving you +know you sort of have this advertised + + align:start position:0% +know you sort of have this advertised + + + align:start position:0% +know you sort of have this advertised +product the advertised product you show + + align:start position:0% +product the advertised product you show + + + align:start position:0% +product the advertised product you show +up at the store to buy the unadvertised + + align:start position:0% +up at the store to buy the unadvertised + + + align:start position:0% +up at the store to buy the unadvertised +product and you find that wow that is + + align:start position:0% +product and you find that wow that is + + + align:start position:0% +product and you find that wow that is +exactly my full willingness to pay I'm + + align:start position:0% +exactly my full willingness to pay I'm + + + align:start position:0% +exactly my full willingness to pay I'm +basically indifferent to walking out + + align:start position:0% +basically indifferent to walking out + + + align:start position:0% +basically indifferent to walking out +versus spending $11 buying + + align:start position:0% +versus spending $11 buying + + + align:start position:0% +versus spending $11 buying +cranberries but you know in + + align:start position:0% +cranberries but you know in + + + align:start position:0% +cranberries but you know in +equilibrium both firms are charging $11 + + align:start position:0% +equilibrium both firms are charging $11 + + + align:start position:0% +equilibrium both firms are charging $11 +for The Cranberries so there's the + + align:start position:0% +for The Cranberries so there's the + + + align:start position:0% +for The Cranberries so there's the +advertised price for the turkey the + + align:start position:0% +advertised price for the turkey the + + + align:start position:0% +advertised price for the turkey the +advertised price of the turkey is a + + align:start position:0% +advertised price of the turkey is a + + + align:start position:0% +advertised price of the turkey is a +great deal and it just is a great deal + + align:start position:0% +great deal and it just is a great deal + + + align:start position:0% +great deal and it just is a great deal +reflecting how much they're going to rip + + align:start position:0% +reflecting how much they're going to rip + + + align:start position:0% +reflecting how much they're going to rip +you off for everything else you buy when + + align:start position:0% +you off for everything else you buy when + + + align:start position:0% +you off for everything else you buy when +you get into the store to buy the turkey + + align:start position:0% +you get into the store to buy the turkey + + + align:start position:0% +you get into the store to buy the turkey +that's a good deal and in equilibrium + + align:start position:0% +that's a good deal and in equilibrium + + + align:start position:0% +that's a good deal and in equilibrium +it's all + + align:start position:0% +it's all + + + align:start position:0% +it's all +neutral okay in equili it's as if you + + align:start position:0% +neutral okay in equili it's as if you + + + align:start position:0% +neutral okay in equili it's as if you +advertise the prices for everything we + + align:start position:0% +advertise the prices for everything we + + + align:start position:0% +advertise the prices for everything we +would get exactly the same outcome it's + + align:start position:0% +would get exactly the same outcome it's + + + align:start position:0% +would get exactly the same outcome it's +it's C+ T pricing it's just in a + + align:start position:0% +it's C+ T pricing it's just in a + + + align:start position:0% +it's C+ T pricing it's just in a +distorted way where one good is really + + align:start position:0% +distorted way where one good is really + + + align:start position:0% +distorted way where one good is really +cheap and then the other goods are + + align:start position:0% +cheap and then the other goods are + + + align:start position:0% +cheap and then the other goods are +expensive okay um and actually you know + + align:start position:0% +expensive okay um and actually you know + + + align:start position:0% +expensive okay um and actually you know +there's actually a paper on on + + align:start position:0% +there's actually a paper on on + + + align:start position:0% +there's actually a paper on on +Thanksgiving noting that in fact it is + + align:start position:0% +Thanksgiving noting that in fact it is + + + align:start position:0% +Thanksgiving noting that in fact it is +true that turkeys are cheapest on + + align:start position:0% +true that turkeys are cheapest on + + + align:start position:0% +true that turkeys are cheapest on +Thanksgiving on any other day of the + + align:start position:0% +Thanksgiving on any other day of the + + + align:start position:0% +Thanksgiving on any other day of the +year and everything else in the grocery + + align:start position:0% +year and everything else in the grocery + + + align:start position:0% +year and everything else in the grocery +store is on average more expensive than + + align:start position:0% +store is on average more expensive than + + + align:start position:0% +store is on average more expensive than +any other day of the year that is a sort + + align:start position:0% +any other day of the year that is a sort + + + align:start position:0% +any other day of the year that is a sort +of this is sort of what firms seem to do + + align:start position:0% +of this is sort of what firms seem to do + + + align:start position:0% +of this is sort of what firms seem to do +is you know turkeys are a loss leader + + align:start position:0% +is you know turkeys are a loss leader + + + align:start position:0% +is you know turkeys are a loss leader +why actually why are turkeys a good loss + + align:start position:0% +why actually why are turkeys a good loss + + + align:start position:0% +why actually why are turkeys a good loss +leader milk is often also a loss leader + + align:start position:0% +leader milk is often also a loss leader + + + align:start position:0% +leader milk is often also a loss leader +at like convenience stores like you know + + align:start position:0% +at like convenience stores like you know + + + align:start position:0% +at like convenience stores like you know +a gallon of milk seems relatively cheap + + align:start position:0% +a gallon of milk seems relatively cheap + + + align:start position:0% +a gallon of milk seems relatively cheap +compared to a bag of potato chips turkey + + align:start position:0% +compared to a bag of potato chips turkey + + + align:start position:0% +compared to a bag of potato chips turkey +and milk are Lo good loss leaders + + align:start position:0% +and milk are Lo good loss leaders + + + align:start position:0% +and milk are Lo good loss leaders +because you don't want to have a lost + + align:start position:0% +because you don't want to have a lost + + + align:start position:0% +because you don't want to have a lost +leader where people come in and stock up + + align:start position:0% +leader where people come in and stock up + + + align:start position:0% +leader where people come in and stock up +and buy 23 of the thing that's + + align:start position:0% +and buy 23 of the thing that's + + + align:start position:0% +and buy 23 of the thing that's +advertised as a great deal and then not + + align:start position:0% +advertised as a great deal and then not + + + align:start position:0% +advertised as a great deal and then not +buy anything else at your store and + + align:start position:0% +buy anything else at your store and + + + align:start position:0% +buy anything else at your store and +exploit you and sort of save it up and + + align:start position:0% +exploit you and sort of save it up and + + + align:start position:0% +exploit you and sort of save it up and +live off that for the next six months + + align:start position:0% +live off that for the next six months + + + align:start position:0% +live off that for the next six months +like Ramen noodles would be a terrible + + align:start position:0% +like Ramen noodles would be a terrible + + + align:start position:0% +like Ramen noodles would be a terrible +loss leader because you'd get the + + align:start position:0% +loss leader because you'd get the + + + align:start position:0% +loss leader because you'd get the +student comes in buys like you know the + + align:start position:0% +student comes in buys like you know the + + + align:start position:0% +student comes in buys like you know the +case of ramen noodles and just leaves + + align:start position:0% +case of ramen noodles and just leaves + + + align:start position:0% +case of ramen noodles and just leaves +with just that but turkeys you really + + align:start position:0% +with just that but turkeys you really + + + align:start position:0% +with just that but turkeys you really +don't want more than one you know + + align:start position:0% +don't want more than one you know + + + align:start position:0% +don't want more than one you know +gallons of milk you really don't want + + align:start position:0% +gallons of milk you really don't want + + + align:start position:0% +gallons of milk you really don't want +more than one so something that you can + + align:start position:0% +more than one so something that you can + + + align:start position:0% +more than one so something that you can +sort of give people a very good deal on + + align:start position:0% +sort of give people a very good deal on + + + align:start position:0% +sort of give people a very good deal on +they buy exactly one and then you rip + + align:start position:0% +they buy exactly one and then you rip + + + align:start position:0% +they buy exactly one and then you rip +them off for everything else that's sort + + align:start position:0% +them off for everything else that's sort + + + align:start position:0% +them off for everything else that's sort +of how you choose your lost + + align:start position:0% +of how you choose your lost + + + align:start position:0% +of how you choose your lost +leaders okay uh but you know the LA and + + align:start position:0% +leaders okay uh but you know the LA and + + + align:start position:0% +leaders okay uh but you know the LA and +matus model says that this is how loss + + align:start position:0% +matus model says that this is how loss + + + align:start position:0% +matus model says that this is how loss +leaders work um uh but they are neutral + + align:start position:0% +leaders work um uh but they are neutral + + + align:start position:0% +leaders work um uh but they are neutral +e economically it's not like Banning + + align:start position:0% +e economically it's not like Banning + + + align:start position:0% +e economically it's not like Banning +them would do any anyone any good or + + align:start position:0% +them would do any anyone any good or + + + align:start position:0% +them would do any anyone any good or +something you know right it's they're + + align:start position:0% +something you know right it's they're + + + align:start position:0% +something you know right it's they're +they're completely neutral for the + + align:start position:0% +they're completely neutral for the + + + align:start position:0% +they're completely neutral for the +firm's profits and neutral for consumers + + align:start position:0% +firm's profits and neutral for consumers + + + align:start position:0% +firm's profits and neutral for consumers +and they do economize an advertising + + align:start position:0% +and they do economize an advertising + + + align:start position:0% +and they do economize an advertising +cost so in that sense they're + + align:start position:0% +cost so in that sense they're + + + align:start position:0% +cost so in that sense they're +good I put carman's picture up there I I + + align:start position:0% +good I put carman's picture up there I I + + + align:start position:0% +good I put carman's picture up there I I +sort of respect you know Carmen at one + + align:start position:0% +sort of respect you know Carmen at one + + + align:start position:0% +sort of respect you know Carmen at one +point was a very successful Economist + + align:start position:0% +point was a very successful Economist + + + align:start position:0% +point was a very successful Economist +and then um uh had been a professor at + + align:start position:0% +and then um uh had been a professor at + + + align:start position:0% +and then um uh had been a professor at +Berkeley and dropped out and became a + + align:start position:0% +Berkeley and dropped out and became a + + + align:start position:0% +Berkeley and dropped out and became a +novelist and actually is a successful + + align:start position:0% +novelist and actually is a successful + + + align:start position:0% +novelist and actually is a successful +novelist although she writes in Spanish + + align:start position:0% +novelist although she writes in Spanish + + + align:start position:0% +novelist although she writes in Spanish +so I've never read any of her books but + + align:start position:0% +so I've never read any of her books but + + + align:start position:0% +so I've never read any of her books but +uh anyway won several prizes for her + + align:start position:0% +uh anyway won several prizes for her + + + align:start position:0% +uh anyway won several prizes for her +fiction writing after she decided to + + align:start position:0% +fiction writing after she decided to + + + align:start position:0% +fiction writing after she decided to +have a second career um okay + + align:start position:0% +have a second career um okay + + + align:start position:0% +have a second career um okay +um uh add-on pricing so + + align:start position:0% +um uh add-on pricing so + + + align:start position:0% +um uh add-on pricing so +um so add-on pricing sort of thinks + + align:start position:0% +um so add-on pricing sort of thinks + + + align:start position:0% +um so add-on pricing sort of thinks +about basically this loss leader idea in + + align:start position:0% +about basically this loss leader idea in + + + align:start position:0% +about basically this loss leader idea in +a vertical um competitive price + + align:start position:0% +a vertical um competitive price + + + align:start position:0% +a vertical um competitive price +discrimination model so there are many + + align:start position:0% +discrimination model so there are many + + + align:start position:0% +discrimination model so there are many +cases + + align:start position:0% +cases + + + align:start position:0% +cases +where firms that are sort of practicing + + align:start position:0% +where firms that are sort of practicing + + + align:start position:0% +where firms that are sort of practicing +second degree price discrimination do + + align:start position:0% +second degree price discrimination do + + + align:start position:0% +second degree price discrimination do +have non-visible prices for add-ons so + + align:start position:0% +have non-visible prices for add-ons so + + + align:start position:0% +have non-visible prices for add-ons so +for instance you go to a hotel and it + + align:start position:0% +for instance you go to a hotel and it + + + align:start position:0% +for instance you go to a hotel and it +like it's very easy to find the price of + + align:start position:0% +like it's very easy to find the price of + + + align:start position:0% +like it's very easy to find the price of +a hotel online and compare price of + + align:start position:0% +a hotel online and compare price of + + + align:start position:0% +a hotel online and compare price of +hotels it's very hard to compare what's + + align:start position:0% +hotels it's very hard to compare what's + + + align:start position:0% +hotels it's very hard to compare what's +the price of the beer in the mini bar or + + align:start position:0% +the price of the beer in the mini bar or + + + align:start position:0% +the price of the beer in the mini bar or +what's the price of the sparkling water + + align:start position:0% +what's the price of the sparkling water + + + align:start position:0% +what's the price of the sparkling water +in the mini bar what's the price of a + + align:start position:0% +in the mini bar what's the price of a + + + align:start position:0% +in the mini bar what's the price of a +Quant in the hotel lobby if I'm in a + + align:start position:0% +Quant in the hotel lobby if I'm in a + + + align:start position:0% +Quant in the hotel lobby if I'm in a +hurry to get somewhere + + align:start position:0% +hurry to get somewhere + + + align:start position:0% +hurry to get somewhere +um you know rental cars it's very easy + + align:start position:0% +um you know rental cars it's very easy + + + align:start position:0% +um you know rental cars it's very easy +to compare the price of the rental car + + align:start position:0% +to compare the price of the rental car + + + align:start position:0% +to compare the price of the rental car +it's very hard to figure out what will I + + align:start position:0% +it's very hard to figure out what will I + + + align:start position:0% +it's very hard to figure out what will I +pay for the car seat if I need a car + + align:start position:0% +pay for the car seat if I need a car + + + align:start position:0% +pay for the car seat if I need a car +seat for my infant when I get there you + + align:start position:0% +seat for my infant when I get there you + + + align:start position:0% +seat for my infant when I get there you +know I don't know I guess you guys are + + align:start position:0% +know I don't know I guess you guys are + + + align:start position:0% +know I don't know I guess you guys are +too young to have infants but you know + + align:start position:0% +too young to have infants but you know + + + align:start position:0% +too young to have infants but you know +it's it's sort of striking to you that + + align:start position:0% +it's it's sort of striking to you that + + + align:start position:0% +it's it's sort of striking to you that +you sort of like you go to rent a car + + align:start position:0% +you sort of like you go to rent a car + + + align:start position:0% +you sort of like you go to rent a car +and you can rent a $20,000 car for1 + + align:start position:0% +and you can rent a $20,000 car for1 + + + align:start position:0% +and you can rent a $20,000 car for1 +19.95 a day and then you want to rent a + + align:start position:0% +19.95 a day and then you want to rent a + + + align:start position:0% +19.95 a day and then you want to rent a +$37 car seat because you don't want to C + + align:start position:0% +$37 car seat because you don't want to C + + + align:start position:0% +$37 car seat because you don't want to C +lug it on the plane and it's like 13.95 + + align:start position:0% +lug it on the plane and it's like 13.95 + + + align:start position:0% +lug it on the plane and it's like 13.95 +a day and you're like you know how can + + align:start position:0% +a day and you're like you know how can + + + align:start position:0% +a day and you're like you know how can +this be that like they can rent me a + + align:start position:0% +this be that like they can rent me a + + + align:start position:0% +this be that like they can rent me a +$20,000 car for $20 and then the $37 car + + align:start position:0% +$20,000 car for $20 and then the $37 car + + + align:start position:0% +$20,000 car for $20 and then the $37 car +SE either charging me $13 a day or + + align:start position:0% +SE either charging me $13 a day or + + + align:start position:0% +SE either charging me $13 a day or +making me carry this enormous think + + align:start position:0% +making me carry this enormous think + + + align:start position:0% +making me carry this enormous think +piece of plastic on the airplane and + + align:start position:0% +piece of plastic on the airplane and + + + align:start position:0% +piece of plastic on the airplane and +it's you know obviously it's it's this + + align:start position:0% +it's you know obviously it's it's this + + + align:start position:0% +it's you know obviously it's it's this +sort of same add-on pricing thing where + + align:start position:0% +sort of same add-on pricing thing where + + + align:start position:0% +sort of same add-on pricing thing where +it's very easy to compare the prices of + + align:start position:0% +it's very easy to compare the prices of + + + align:start position:0% +it's very easy to compare the prices of +the cars and not of the and not of the + + align:start position:0% +the cars and not of the and not of the + + + align:start position:0% +the cars and not of the and not of the +car seats therefore the car seat is + + align:start position:0% +car seats therefore the car seat is + + + align:start position:0% +car seats therefore the car seat is +priced at V2 what is your disutility + + align:start position:0% +priced at V2 what is your disutility + + + align:start position:0% +priced at V2 what is your disutility +from carrying a car seat on a plane + + align:start position:0% +from carrying a car seat on a plane + + + align:start position:0% +from carrying a car seat on a plane +that's what they'll charge you uh and + + align:start position:0% +that's what they'll charge you uh and + + + align:start position:0% +that's what they'll charge you uh and +then the you know cars are sort of some + + align:start position:0% +then the you know cars are sort of some + + + align:start position:0% +then the you know cars are sort of some +sense the loss leader to make money + + align:start position:0% +sense the loss leader to make money + + + align:start position:0% +sense the loss leader to make money +selling the car seats in the rental car + + align:start position:0% +selling the car seats in the rental car + + + align:start position:0% +selling the car seats in the rental car +insurance um you know uh inkjet printers + + align:start position:0% +insurance um you know uh inkjet printers + + + align:start position:0% +insurance um you know uh inkjet printers +I mentioned earlier that right again + + align:start position:0% +I mentioned earlier that right again + + + align:start position:0% +I mentioned earlier that right again +like the inkjet printer is very cheap + + align:start position:0% +like the inkjet printer is very cheap + + + align:start position:0% +like the inkjet printer is very cheap +but they've sort of invented this inkjet + + align:start position:0% +but they've sort of invented this inkjet + + + align:start position:0% +but they've sort of invented this inkjet +printer that has almost no ink in it + + align:start position:0% +printer that has almost no ink in it + + + align:start position:0% +printer that has almost no ink in it +when you buy it and then it's got the + + align:start position:0% +when you buy it and then it's got the + + + align:start position:0% +when you buy it and then it's got the +starter cartridge and then the sort of + + align:start position:0% +starter cartridge and then the sort of + + + align:start position:0% +starter cartridge and then the sort of +regular cartridge for the internet + + align:start position:0% +regular cartridge for the internet + + + align:start position:0% +regular cartridge for the internet +printer is much more expensive and + + align:start position:0% +printer is much more expensive and + + + align:start position:0% +printer is much more expensive and +that's sort of the Hidden feature when + + align:start position:0% +that's sort of the Hidden feature when + + + align:start position:0% +that's sort of the Hidden feature when +you buy the + + align:start position:0% +you buy the + + + align:start position:0% +you buy the +cartridge so you know to think about how + + align:start position:0% +cartridge so you know to think about how + + + align:start position:0% +cartridge so you know to think about how +this works in vertical competition + + align:start position:0% +this works in vertical competition + + + align:start position:0% +this works in vertical competition +um you know L mudas was purely additive + + align:start position:0% +um you know L mudas was purely additive + + + align:start position:0% +um you know L mudas was purely additive +competition it wasn't a vertical model + + align:start position:0% +competition it wasn't a vertical model + + + align:start position:0% +competition it wasn't a vertical model +so imagine you have firms advertised + + align:start position:0% +so imagine you have firms advertised + + + align:start position:0% +so imagine you have firms advertised +prices for their lowquality goods like + + align:start position:0% +prices for their lowquality goods like + + + align:start position:0% +prices for their lowquality goods like +the rental car without a car + + align:start position:0% +the rental car without a car + + + align:start position:0% +the rental car without a car +seat + + align:start position:0% +seat + + + align:start position:0% +seat +um cost SL and both sh both have cost c + + align:start position:0% +um cost SL and both sh both have cost c + + + align:start position:0% +um cost SL and both sh both have cost c +as if the car seat is essentially free + + align:start position:0% +as if the car seat is essentially free + + + align:start position:0% +as if the car seat is essentially free +for them to + + align:start position:0% +for them to + + + align:start position:0% +for them to +provide um consumers incur some cost um + + align:start position:0% +provide um consumers incur some cost um + + + align:start position:0% +provide um consumers incur some cost um +to visit Jay and learn the price uh so + + align:start position:0% +to visit Jay and learn the price uh so + + + align:start position:0% +to visit Jay and learn the price uh so +consumers have to visit the firm to + + align:start position:0% +consumers have to visit the firm to + + + align:start position:0% +consumers have to visit the firm to +learn the price of the um uh upgrades + + align:start position:0% +learn the price of the um uh upgrades + + + align:start position:0% +learn the price of the um uh upgrades +you have to spend some time on the + + align:start position:0% +you have to spend some time on the + + + align:start position:0% +you have to spend some time on the +website learning what it costs to get a + + align:start position:0% +website learning what it costs to get a + + + align:start position:0% +website learning what it costs to get a +car seat added to your rental car and + + align:start position:0% +car seat added to your rental car and + + + align:start position:0% +car seat added to your rental car and +then that would let you upgrade in + + align:start position:0% +then that would let you upgrade in + + + align:start position:0% +then that would let you upgrade in +quality and then again let's do the + + align:start position:0% +quality and then again let's do the + + + align:start position:0% +quality and then again let's do the +competition on two lines so Epsilon i1 + + align:start position:0% +competition on two lines so Epsilon i1 + + + align:start position:0% +competition on two lines so Epsilon i1 +Epsilon I2 independent again you know + + align:start position:0% +Epsilon I2 independent again you know + + + align:start position:0% +Epsilon I2 independent again you know +same thing this + + align:start position:0% +same thing this + + + align:start position:0% +same thing this +setup so this setup where what you do is + + align:start position:0% +setup so this setup where what you do is + + + align:start position:0% +setup so this setup where what you do is +Imagine This setup where you're only + + align:start position:0% +Imagine This setup where you're only + + + align:start position:0% +Imagine This setup where you're only +advertising the price of the lowquality + + align:start position:0% +advertising the price of the lowquality + + + align:start position:0% +advertising the price of the lowquality +good and then consumers have to pay + + align:start position:0% +good and then consumers have to pay + + + align:start position:0% +good and then consumers have to pay +something after they arrive or after + + align:start position:0% +something after they arrive or after + + + align:start position:0% +something after they arrive or after +they've spent some time in investigating + + align:start position:0% +they've spent some time in investigating + + + align:start position:0% +they've spent some time in investigating +your firm to learn what it cost to + + align:start position:0% +your firm to learn what it cost to + + + align:start position:0% +your firm to learn what it cost to +upgrade to the high quality + + align:start position:0% +upgrade to the high quality + + + align:start position:0% +upgrade to the high quality +good um what happens um well you know + + align:start position:0% +good um what happens um well you know + + + align:start position:0% +good um what happens um well you know +there's an equilibrium where like and + + align:start position:0% +there's an equilibrium where like and + + + align:start position:0% +there's an equilibrium where like and +law and + + align:start position:0% +law and + + + align:start position:0% +law and +matus um the price of the upgrade is the + + align:start position:0% +matus um the price of the upgrade is the + + + align:start position:0% +matus um the price of the upgrade is the +full value for the + + align:start position:0% +full value for the + + + align:start position:0% +full value for the +upgrade uh for the high types so the + + align:start position:0% +upgrade uh for the high types so the + + + align:start position:0% +upgrade uh for the high types so the +price of the upgrade is what are the + + align:start position:0% +price of the upgrade is what are the + + + align:start position:0% +price of the upgrade is what are the +businessmen willing to pay for the + + align:start position:0% +businessmen willing to pay for the + + + align:start position:0% +businessmen willing to pay for the +rental car + + align:start position:0% +rental car + + + align:start position:0% +rental car +seat um and then price of the low + + align:start position:0% +seat um and then price of the low + + + align:start position:0% +seat um and then price of the low +quality good ends up being this um which + + align:start position:0% +quality good ends up being this um which + + + align:start position:0% +quality good ends up being this um which +I won't get into um but main applied + + align:start position:0% +I won't get into um but main applied + + + align:start position:0% +I won't get into um but main applied +conclusions are that profits in this + + align:start position:0% +conclusions are that profits in this + + + align:start position:0% +conclusions are that profits in this +game are higher than the profits in the + + align:start position:0% +game are higher than the profits in the + + + align:start position:0% +game are higher than the profits in the +game where PL and pH are both visible so + + align:start position:0% +game where PL and pH are both visible so + + + align:start position:0% +game where PL and pH are both visible so +in this competitive price discrimination + + align:start position:0% +in this competitive price discrimination + + + align:start position:0% +in this competitive price discrimination +model add-on pricing or these these the + + align:start position:0% +model add-on pricing or these these the + + + align:start position:0% +model add-on pricing or these these the +sort of loss leaders are not uh neutral + + align:start position:0% +sort of loss leaders are not uh neutral + + + align:start position:0% +sort of loss leaders are not uh neutral +they raise prices and not only do they + + align:start position:0% +they raise prices and not only do they + + + align:start position:0% +they raise prices and not only do they +raise prices but they make all consumers + + align:start position:0% +raise prices but they make all consumers + + + align:start position:0% +raise prices but they make all consumers +worse off um than in the game where the + + align:start position:0% +worse off um than in the game where the + + + align:start position:0% +worse off um than in the game where the +the lowquality good didn't exist so if I + + align:start position:0% +the lowquality good didn't exist so if I + + + align:start position:0% +the lowquality good didn't exist so if I +ban the production of of rental cars + + align:start position:0% +ban the production of of rental cars + + + align:start position:0% +ban the production of of rental cars +that don't come with a car seat if you + + align:start position:0% +that don't come with a car seat if you + + + align:start position:0% +that don't come with a car seat if you +ask for it for free all consumers would + + align:start position:0% +ask for it for free all consumers would + + + align:start position:0% +ask for it for free all consumers would +be better off the low types would be + + align:start position:0% +be better off the low types would be + + + align:start position:0% +be better off the low types would be +better off and the high types would be + + align:start position:0% +better off and the high types would be + + + align:start position:0% +better off and the high types would be +better off um the high types are better + + align:start position:0% +better off um the high types are better + + + align:start position:0% +better off um the high types are better +off because they would pay a low price + + align:start position:0% +off because they would pay a low price + + + align:start position:0% +off because they would pay a low price +without this add-on pricing scheme the + + align:start position:0% +without this add-on pricing scheme the + + + align:start position:0% +without this add-on pricing scheme the +low types are better off because they're + + align:start position:0% +low types are better off because they're + + + align:start position:0% +low types are better off because they're +getting a better quality good instead of + + align:start position:0% +getting a better quality good instead of + + + align:start position:0% +getting a better quality good instead of +having to carry their car seats on the + + align:start position:0% +having to carry their car seats on the + + + align:start position:0% +having to carry their car seats on the +plane okay + + align:start position:0% +plane okay + + + align:start position:0% +plane okay +I'm short on time so when I I skip that + + align:start position:0% +I'm short on time so when I I skip that + + + align:start position:0% +I'm short on time so when I I skip that +but let just sort of give you the + + align:start position:0% +but let just sort of give you the + + + align:start position:0% +but let just sort of give you the +intuition for these why that add-on + + align:start position:0% +intuition for these why that add-on + + + align:start position:0% +intuition for these why that add-on +pricing becomes + + align:start position:0% +pricing becomes + + + align:start position:0% +pricing becomes +non-neutral you know imagine think about + + align:start position:0% +non-neutral you know imagine think about + + + align:start position:0% +non-neutral you know imagine think about +reducing your price to P star minus DP + + align:start position:0% +reducing your price to P star minus DP + + + align:start position:0% +reducing your price to P star minus DP +in the add-on model and doing the same + + align:start position:0% +in the add-on model and doing the same + + + align:start position:0% +in the add-on model and doing the same +in the model with no low quality + + align:start position:0% +in the model with no low quality + + + align:start position:0% +in the model with no low quality +good in both models what you lose from a + + align:start position:0% +good in both models what you lose from a + + + align:start position:0% +good in both models what you lose from a +price cut is 1 half DP from charging the + + align:start position:0% +price cut is 1 half DP from charging the + + + align:start position:0% +price cut is 1 half DP from charging the +lower prices to the half the consumers + + align:start position:0% +lower prices to the half the consumers + + + align:start position:0% +lower prices to the half the consumers +you're + + align:start position:0% +you're + + + align:start position:0% +you're +serving in both models what you're + + align:start position:0% +serving in both models what you're + + + align:start position:0% +serving in both models what you're +gaining is + + align:start position:0% +gaining is + + + align:start position:0% +gaining is +from the price cut is the number of + + align:start position:0% +from the price cut is the number of + + + align:start position:0% +from the price cut is the number of +customers gained times the per customer + + align:start position:0% +customers gained times the per customer + + + align:start position:0% +customers gained times the per customer +profit on the marginal consumer that you + + align:start position:0% +profit on the marginal consumer that you + + + align:start position:0% +profit on the marginal consumer that you +gain and so because you know in both + + align:start position:0% +gain and so because you know in both + + + align:start position:0% +gain and so because you know in both +models if you try to make you know in + + align:start position:0% +models if you try to make you know in + + + align:start position:0% +models if you try to make you know in +both models the first order condition + + align:start position:0% +both models the first order condition + + + align:start position:0% +both models the first order condition +this has to equal + + align:start position:0% +this has to equal + + + align:start position:0% +this has to equal +this the 1 half DP is the same in both + + align:start position:0% +this the 1 half DP is the same in both + + + align:start position:0% +this the 1 half DP is the same in both +the number of customers gained in both + + align:start position:0% +the number of customers gained in both + + + align:start position:0% +the number of customers gained in both +therefore the per customer profit on the + + align:start position:0% +therefore the per customer profit on the + + + align:start position:0% +therefore the per customer profit on the +marginal consumer is the same in both + + align:start position:0% +marginal consumer is the same in both + + + align:start position:0% +marginal consumer is the same in both +models so in both models the per + + align:start position:0% +models so in both models the per + + + align:start position:0% +models so in both models the per +customer profit you make on the marginal + + align:start position:0% +customer profit you make on the marginal + + + align:start position:0% +customer profit you make on the marginal +consumer is the + + align:start position:0% +consumer is the + + + align:start position:0% +consumer is the +same um + + align:start position:0% +same um + + + align:start position:0% +same um +but profits are based on profits on the + + align:start position:0% +but profits are based on profits on the + + + align:start position:0% +but profits are based on profits on the +average consumer not the marginal + + align:start position:0% +average consumer not the marginal + + + align:start position:0% +average consumer not the marginal +consumer and if you think about what + + align:start position:0% +consumer and if you think about what + + + align:start position:0% +consumer and if you think about what +goes on in a model like this when I cut + + align:start position:0% +goes on in a model like this when I cut + + + align:start position:0% +goes on in a model like this when I cut +my price who do I get by like I offer my + + align:start position:0% +my price who do I get by like I offer my + + + align:start position:0% +my price who do I get by like I offer my +rental car for $1 less than than every + + align:start position:0% +rental car for $1 less than than every + + + align:start position:0% +rental car for $1 less than than every +than everybody else's rental car my + + align:start position:0% +than everybody else's rental car my + + + align:start position:0% +than everybody else's rental car my +rental car is $38.95 a day instead of $ + + align:start position:0% +rental car is $38.95 a day instead of $ + + + align:start position:0% +rental car is $38.95 a day instead of $ +39.95 a day I get all the cheap skates + + align:start position:0% +39.95 a day I get all the cheap skates + + + align:start position:0% +39.95 a day I get all the cheap skates +and I get all the cheap skates where the + + align:start position:0% +and I get all the cheap skates where the + + + align:start position:0% +and I get all the cheap skates where the +low types were willing to carry their + + align:start position:0% +low types were willing to carry their + + + align:start position:0% +low types were willing to carry their +car seat on a plane and spend extra time + + align:start position:0% +car seat on a plane and spend extra time + + + align:start position:0% +car seat on a plane and spend extra time +waiting at the gate to get their car + + align:start position:0% +waiting at the gate to get their car + + + align:start position:0% +waiting at the gate to get their car +seat and and carrying it through the + + align:start position:0% +seat and and carrying it through the + + + align:start position:0% +seat and and carrying it through the +airport to save the 13.95 a day and so + + align:start position:0% +airport to save the 13.95 a day and so + + + align:start position:0% +airport to save the 13.95 a day and so +because the cheap skates are an + + align:start position:0% +because the cheap skates are an + + + align:start position:0% +because the cheap skates are an +adversely selected population relative + + align:start position:0% +adversely selected population relative + + + align:start position:0% +adversely selected population relative +to the full population so I when I cut + + align:start position:0% +to the full population so I when I cut + + + align:start position:0% +to the full population so I when I cut +my price in this add-on model I get a + + align:start position:0% +my price in this add-on model I get a + + + align:start position:0% +my price in this add-on model I get a +bunch of cheap + + align:start position:0% +bunch of cheap + + + align:start position:0% +bunch of cheap +skates if the marginal profit so there's + + align:start position:0% +skates if the marginal profit so there's + + + align:start position:0% +skates if the marginal profit so there's +in the add-on model there's this big gap + + align:start position:0% +in the add-on model there's this big gap + + + align:start position:0% +in the add-on model there's this big gap +between the profits on the marginal + + align:start position:0% +between the profits on the marginal + + + align:start position:0% +between the profits on the marginal +consumers and the profits on the average + + align:start position:0% +consumers and the profits on the average + + + align:start position:0% +consumers and the profits on the average +consumers whereas in the single good + + align:start position:0% +consumers whereas in the single good + + + align:start position:0% +consumers whereas in the single good +product the marginal and average + + align:start position:0% +product the marginal and average + + + align:start position:0% +product the marginal and average +consumers are exactly the + + align:start position:0% +consumers are exactly the + + + align:start position:0% +consumers are exactly the +same so what we've done is we've just + + align:start position:0% +same so what we've done is we've just + + + align:start position:0% +same so what we've done is we've just +created this gap between marginal + + align:start position:0% +created this gap between marginal + + + align:start position:0% +created this gap between marginal +consumers and average consumers and that + + align:start position:0% +consumers and average consumers and that + + + align:start position:0% +consumers and average consumers and that +ends up raising equilibrium prices some + + align:start position:0% +ends up raising equilibrium prices some + + + align:start position:0% +ends up raising equilibrium prices some +you've some you've created an adverse + + align:start position:0% +you've some you've created an adverse + + + align:start position:0% +you've some you've created an adverse +selection problem and that adverse + + align:start position:0% +selection problem and that adverse + + + align:start position:0% +selection problem and that adverse +selection + + align:start position:0% +selection + + + align:start position:0% +selection +problem uh makes it hard for firms to + + align:start position:0% +problem uh makes it hard for firms to + + + align:start position:0% +problem uh makes it hard for firms to +price compete against other firms + + align:start position:0% +price compete against other firms + + + align:start position:0% +price compete against other firms +because if you cut prices you just get + + align:start position:0% +because if you cut prices you just get + + + align:start position:0% +because if you cut prices you just get +cheap skates on whom you lose money + + align:start position:0% +cheap skates on whom you lose money + + + align:start position:0% +cheap skates on whom you lose money +money renting the cars so + + align:start position:0% +money renting the cars so + + + align:start position:0% +money renting the cars so +cheap okay any questions no so okay + + align:start position:0% +cheap okay any questions no so okay + + + align:start position:0% +cheap okay any questions no so okay +that leave me with uh 10 minutes and I I + + align:start position:0% +that leave me with uh 10 minutes and I I + + + align:start position:0% +that leave me with uh 10 minutes and I I +said I would do this paper very quickly + + align:start position:0% +said I would do this paper very quickly + + + align:start position:0% +said I would do this paper very quickly +because this really follows very much + + align:start position:0% +because this really follows very much + + + align:start position:0% +because this really follows very much +methodology Tobias is talking about on + + align:start position:0% +methodology Tobias is talking about on + + + align:start position:0% +methodology Tobias is talking about on +Monday um of next week so you know + + align:start position:0% +Monday um of next week so you know + + + align:start position:0% +Monday um of next week so you know +Miller and Weinberg is is a very similar + + align:start position:0% +Miller and Weinberg is is a very similar + + + align:start position:0% +Miller and Weinberg is is a very similar +paper to breast and hand and it's a much + + align:start position:0% +paper to breast and hand and it's a much + + + align:start position:0% +paper to breast and hand and it's a much +more modern well done um you know + + align:start position:0% +more modern well done um you know + + + align:start position:0% +more modern well done um you know +Frontier quality um uh piece of Applied + + align:start position:0% +Frontier quality um uh piece of Applied + + + align:start position:0% +Frontier quality um uh piece of Applied +work um the applied question is whether + + align:start position:0% +work um the applied question is whether + + + align:start position:0% +work um the applied question is whether +us beer price the rise in US beer prices + + align:start position:0% +us beer price the rise in US beer prices + + + align:start position:0% +us beer price the rise in US beer prices +following the 2008 uh joint venture of + + align:start position:0% +following the 2008 uh joint venture of + + + align:start position:0% +following the 2008 uh joint venture of +Miller and Kors can be explained as a + + align:start position:0% +Miller and Kors can be explained as a + + + align:start position:0% +Miller and Kors can be explained as a +consequence of just static price + + align:start position:0% +consequence of just static price + + + align:start position:0% +consequence of just static price +competition or if we need some degree of + + align:start position:0% +competition or if we need some degree of + + + align:start position:0% +competition or if we need some degree of +cooperation or collusion among the firms + + align:start position:0% +cooperation or collusion among the firms + + + align:start position:0% +cooperation or collusion among the firms +to understand what happens and so what + + align:start position:0% +to understand what happens and so what + + + align:start position:0% +to understand what happens and so what +it does is it estimates a model that + + align:start position:0% +it does is it estimates a model that + + + align:start position:0% +it does is it estimates a model that +assumes that the firms were paying + + align:start position:0% +assumes that the firms were paying + + + align:start position:0% +assumes that the firms were paying +static uh you know natur equ static + + align:start position:0% +static uh you know natur equ static + + + align:start position:0% +static uh you know natur equ static +differentiated product competition + + align:start position:0% +differentiated product competition + + + align:start position:0% +differentiated product competition +before the merger and then after the + + align:start position:0% +before the merger and then after the + + + align:start position:0% +before the merger and then after the +merger um Miller Kors and anheiser Bush + + align:start position:0% +merger um Miller Kors and anheiser Bush + + + align:start position:0% +merger um Miller Kors and anheiser Bush +are partially + + align:start position:0% +are partially + + + align:start position:0% +are partially +Cooperative uh and then the partial + + align:start position:0% +Cooperative uh and then the partial + + + align:start position:0% +Cooperative uh and then the partial +Cooperative model what it does is it + + align:start position:0% +Cooperative model what it does is it + + + align:start position:0% +Cooperative model what it does is it +like Brean had three or four models they + + align:start position:0% +like Brean had three or four models they + + + align:start position:0% +like Brean had three or four models they +have a Continuum of models the Continuum + + align:start position:0% +have a Continuum of models the Continuum + + + align:start position:0% +have a Continuum of models the Continuum +of models is assume it's as if each firm + + align:start position:0% +of models is assume it's as if each firm + + + align:start position:0% +of models is assume it's as if each firm +is maximizing their own profit plus + + align:start position:0% +is maximizing their own profit plus + + + align:start position:0% +is maximizing their own profit plus +Kappa times the profit of the other + + align:start position:0% +Kappa times the profit of the other + + + align:start position:0% +Kappa times the profit of the other +firms so Kappa equals one would be full + + align:start position:0% +firms so Kappa equals one would be full + + + align:start position:0% +firms so Kappa equals one would be full +collusion usion Kappa equals z would be + + align:start position:0% +collusion usion Kappa equals z would be + + + align:start position:0% +collusion usion Kappa equals z would be +static competition and Kappa in between + + align:start position:0% +static competition and Kappa in between + + + align:start position:0% +static competition and Kappa in between +is some degree of partial collusion + + align:start position:0% +is some degree of partial collusion + + + align:start position:0% +is some degree of partial collusion +between the firms okay and then what + + align:start position:0% +between the firms okay and then what + + + align:start position:0% +between the firms okay and then what +they note is that in this model with + + align:start position:0% +they note is that in this model with + + + align:start position:0% +they note is that in this model with +this sort of Contin of models you can + + align:start position:0% +this sort of Contin of models you can + + + align:start position:0% +this sort of Contin of models you can +test whether Kappa equals zero to say + + align:start position:0% +test whether Kappa equals zero to say + + + align:start position:0% +test whether Kappa equals zero to say +does the static competition model + + align:start position:0% +does the static competition model + + + align:start position:0% +does the static competition model +explain what's going on or you know do I + + align:start position:0% +explain what's going on or you know do I + + + align:start position:0% +explain what's going on or you know do I +need to have some degree of collusion + + align:start position:0% +need to have some degree of collusion + + + align:start position:0% +need to have some degree of collusion +starting after the the Miller cores merg + + align:start position:0% +starting after the the Miller cores merg + + + align:start position:0% +starting after the the Miller cores merg +to understand why prices are what they + + align:start position:0% +to understand why prices are what they + + + align:start position:0% +to understand why prices are what they +are so anyway I I won't go into the + + align:start position:0% +are so anyway I I won't go into the + + + align:start position:0% +are so anyway I I won't go into the +details here but um background you know + + align:start position:0% +details here but um background you know + + + align:start position:0% +details here but um background you know +I think even graduate students drink + + align:start position:0% +I think even graduate students drink + + + align:start position:0% +I think even graduate students drink +craft beer these days but you know + + align:start position:0% +craft beer these days but you know + + + align:start position:0% +craft beer these days but you know +despite the incredible rise in craft + + align:start position:0% +despite the incredible rise in craft + + + align:start position:0% +despite the incredible rise in craft +beer most Americans still drink really + + align:start position:0% +beer most Americans still drink really + + + align:start position:0% +beer most Americans still drink really +cheap beer um so you know most Americans + + align:start position:0% +cheap beer um so you know most Americans + + + align:start position:0% +cheap beer um so you know most Americans +drink Bud Light Coors Light uh Miller + + align:start position:0% +drink Bud Light Coors Light uh Miller + + + align:start position:0% +drink Bud Light Coors Light uh Miller +Light you know maybe May that's least + + align:start position:0% +Light you know maybe May that's least + + + align:start position:0% +Light you know maybe May that's least +most sales because people buy budlight + + align:start position:0% +most sales because people buy budlight + + + align:start position:0% +most sales because people buy budlight +in 30 packs um but um there's been + + align:start position:0% +in 30 packs um but um there's been + + + align:start position:0% +in 30 packs um but um there's been +tremendous consolidation of beer + + align:start position:0% +tremendous consolidation of beer + + + align:start position:0% +tremendous consolidation of beer +ownership in the past 20 years globally + + align:start position:0% +ownership in the past 20 years globally + + + align:start position:0% +ownership in the past 20 years globally +so basically in every country around the + + align:start position:0% +so basically in every country around the + + + align:start position:0% +so basically in every country around the +world the same three companies sell all + + align:start position:0% +world the same three companies sell all + + + align:start position:0% +world the same three companies sell all +the beer uh and so you know the same + + align:start position:0% +the beer uh and so you know the same + + + align:start position:0% +the beer uh and so you know the same +companies that sell anheiser bush in the + + align:start position:0% +companies that sell anheiser bush in the + + + align:start position:0% +companies that sell anheiser bush in the +United States are also ones that sell + + align:start position:0% +United States are also ones that sell + + + align:start position:0% +United States are also ones that sell +Becks and Germany and celella Arta and + + align:start position:0% +Becks and Germany and celella Arta and + + + align:start position:0% +Becks and Germany and celella Arta and +England and whatever but these companies + + align:start position:0% +England and whatever but these companies + + + align:start position:0% +England and whatever but these companies +have put together portfolios of beers + + align:start position:0% +have put together portfolios of beers + + + align:start position:0% +have put together portfolios of beers +um you know prior to the N 2008 Miller + + align:start position:0% +um you know prior to the N 2008 Miller + + + align:start position:0% +um you know prior to the N 2008 Miller +Kors joint venture um anheiser bush + + align:start position:0% +Kors joint venture um anheiser bush + + + align:start position:0% +Kors joint venture um anheiser bush +inbev had a market share of about + + align:start position:0% +inbev had a market share of about + + + align:start position:0% +inbev had a market share of about +35% Miller had a a market share of 18% K + + align:start position:0% +35% Miller had a a market share of 18% K + + + align:start position:0% +35% Miller had a a market share of 18% K +had an market share of 11% and again you + + align:start position:0% +had an market share of 11% and again you + + + align:start position:0% +had an market share of 11% and again you +know those are market shares in the + + align:start position:0% +know those are market shares in the + + + align:start position:0% +know those are market shares in the +whole Beer Market if you take away the + + align:start position:0% +whole Beer Market if you take away the + + + align:start position:0% +whole Beer Market if you take away the +premium beers there are many submarkets + + align:start position:0% +premium beers there are many submarkets + + + align:start position:0% +premium beers there are many submarkets +in which those firms have much higher + + align:start position:0% +in which those firms have much higher + + + align:start position:0% +in which those firms have much higher +shares okay and despite the fact that + + align:start position:0% +shares okay and despite the fact that + + + align:start position:0% +shares okay and despite the fact that +sort of these were the overall market + + align:start position:0% +sort of these were the overall market + + + align:start position:0% +sort of these were the overall market +shares um Miller and KS were in 2008 + + align:start position:0% +shares um Miller and KS were in 2008 + + + align:start position:0% +shares um Miller and KS were in 2008 +allowed to form a joint venture and sell + + align:start position:0% +allowed to form a joint venture and sell + + + align:start position:0% +allowed to form a joint venture and sell +their beer together + + align:start position:0% +their beer together + + + align:start position:0% +their beer together +um so and Miller cores argued that yes + + align:start position:0% +um so and Miller cores argued that yes + + + align:start position:0% +um so and Miller cores argued that yes +it looks like the second and third + + align:start position:0% +it looks like the second and third + + + align:start position:0% +it looks like the second and third +biggest firms in the market are merging + + align:start position:0% +biggest firms in the market are merging + + + align:start position:0% +biggest firms in the market are merging +together to be create a three- firm + + align:start position:0% +together to be create a three- firm + + + align:start position:0% +together to be create a three- firm +competition to two- firm competition but + + align:start position:0% +competition to two- firm competition but + + + align:start position:0% +competition to two- firm competition but +this is going to be good for consumers + + align:start position:0% +this is going to be good for consumers + + + align:start position:0% +this is going to be good for consumers +because there's going to be enough cost + + align:start position:0% +because there's going to be enough cost + + + align:start position:0% +because there's going to be enough cost +savings that we're going to have an + + align:start position:0% +savings that we're going to have an + + + align:start position:0% +savings that we're going to have an +incentive to lower our prices particular + + align:start position:0% +incentive to lower our prices particular + + + align:start position:0% +incentive to lower our prices particular +you know Kors was mostly brewed in + + align:start position:0% +you know Kors was mostly brewed in + + + align:start position:0% +you know Kors was mostly brewed in +Colorado and then had to be shipped all + + align:start position:0% +Colorado and then had to be shipped all + + + align:start position:0% +Colorado and then had to be shipped all +across the United States which is + + align:start position:0% +across the United States which is + + + align:start position:0% +across the United States which is +expensive they're like if only we could + + align:start position:0% +expensive they're like if only we could + + + align:start position:0% +expensive they're like if only we could +produce all the Kors beer and all those + + align:start position:0% +produce all the Kors beer and all those + + + align:start position:0% +produce all the Kors beer and all those +Miller plants that are distributed + + align:start position:0% +Miller plants that are distributed + + + align:start position:0% +Miller plants that are distributed +around the country and then share trucks + + align:start position:0% +around the country and then share trucks + + + align:start position:0% +around the country and then share trucks +shipping the Miller and Coors to all the + + align:start position:0% +shipping the Miller and Coors to all the + + + align:start position:0% +shipping the Miller and Coors to all the +beer distributors then we'd save on the + + align:start position:0% +beer distributors then we'd save on the + + + align:start position:0% +beer distributors then we'd save on the +trucking costs we'd save on the shipping + + align:start position:0% +trucking costs we'd save on the shipping + + + align:start position:0% +trucking costs we'd save on the shipping +costs cost will go down so much that + + align:start position:0% +costs cost will go down so much that + + + align:start position:0% +costs cost will go down so much that +consumers will be better off uh and the + + align:start position:0% +consumers will be better off uh and the + + + align:start position:0% +consumers will be better off uh and the +justice department approved the merger + + align:start position:0% +justice department approved the merger + + + align:start position:0% +justice department approved the merger +um uh anyway um you know very beautiful + + align:start position:0% +um uh anyway um you know very beautiful + + + align:start position:0% +um uh anyway um you know very beautiful +graph to sort of giving the basic thing + + align:start position:0% +graph to sort of giving the basic thing + + + align:start position:0% +graph to sort of giving the basic thing +of did what the firms tell the justice + + align:start position:0% +of did what the firms tell the justice + + + align:start position:0% +of did what the firms tell the justice +department come true here are the graphs + + align:start position:0% +department come true here are the graphs + + + align:start position:0% +department come true here are the graphs +of the prices for Miller Light Bud Light + + align:start position:0% +of the prices for Miller Light Bud Light + + + align:start position:0% +of the prices for Miller Light Bud Light +Kors light leading up to the time of the + + align:start position:0% +Kors light leading up to the time of the + + + align:start position:0% +Kors light leading up to the time of the +merg merer and you can see beer prices + + align:start position:0% +merg merer and you can see beer prices + + + align:start position:0% +merg merer and you can see beer prices +were trending down um after the merger + + align:start position:0% +were trending down um after the merger + + + align:start position:0% +were trending down um after the merger +there was this temporary sale on Miller + + align:start position:0% +there was this temporary sale on Miller + + + align:start position:0% +there was this temporary sale on Miller +Light but then by a couple months after + + align:start position:0% +Light but then by a couple months after + + + align:start position:0% +Light but then by a couple months after +the merger prices went up + + align:start position:0% +the merger prices went up + + + align:start position:0% +the merger prices went up +there so there's just a very + + align:start position:0% +there so there's just a very + + + align:start position:0% +there so there's just a very +clear departure from Trend and the + + align:start position:0% +clear departure from Trend and the + + + align:start position:0% +clear departure from Trend and the +prices of budlight Miller Light Coors + + align:start position:0% +prices of budlight Miller Light Coors + + + align:start position:0% +prices of budlight Miller Light Coors +Light jump after the Miller Kors + + align:start position:0% +Light jump after the Miller Kors + + + align:start position:0% +Light jump after the Miller Kors +merger okay um their competitor prices + + align:start position:0% +merger okay um their competitor prices + + + align:start position:0% +merger okay um their competitor prices +didn't do so much so that two largest + + align:start position:0% +didn't do so much so that two largest + + + align:start position:0% +didn't do so much so that two largest +Brands not sold by uh anheiser Bush + + align:start position:0% +Brands not sold by uh anheiser Bush + + + align:start position:0% +Brands not sold by uh anheiser Bush +inbev or Miller Kors are Heineken and + + align:start position:0% +inbev or Miller Kors are Heineken and + + + align:start position:0% +inbev or Miller Kors are Heineken and +Corona um Heineken and Corona + + align:start position:0% +Corona um Heineken and Corona + + + align:start position:0% +Corona um Heineken and Corona +prices you know you don't notice maybe + + align:start position:0% +prices you know you don't notice maybe + + + align:start position:0% +prices you know you don't notice maybe +you look and see there's a little jump + + align:start position:0% +you look and see there's a little jump + + + align:start position:0% +you look and see there's a little jump +up here but it seems like they're mostly + + align:start position:0% +up here but it seems like they're mostly + + + align:start position:0% +up here but it seems like they're mostly +on Trend so if we take that as a + + align:start position:0% +on Trend so if we take that as a + + + align:start position:0% +on Trend so if we take that as a +differences and differences thing to say + + align:start position:0% +differences and differences thing to say + + + align:start position:0% +differences and differences thing to say +there doesn't seem to be a difference in + + align:start position:0% +there doesn't seem to be a difference in + + + align:start position:0% +there doesn't seem to be a difference in +the cost of producing beer if there's no + + align:start position:0% +the cost of producing beer if there's no + + + align:start position:0% +the cost of producing beer if there's no +difference in the cost of producing beer + + align:start position:0% +difference in the cost of producing beer + + + align:start position:0% +difference in the cost of producing beer +what you get is that the 12 packs of the + + align:start position:0% +what you get is that the 12 packs of the + + + align:start position:0% +what you get is that the 12 packs of the +flagship Brands went up by about uh 10% + + align:start position:0% +flagship Brands went up by about uh 10% + + + align:start position:0% +flagship Brands went up by about uh 10% +overall prices went up by about 5% you + + align:start position:0% +overall prices went up by about 5% you + + + align:start position:0% +overall prices went up by about 5% you +know it's basically it's as if they you + + align:start position:0% +know it's basically it's as if they you + + + align:start position:0% +know it's basically it's as if they you +know like a 12 if a 12pack of Bud Light + + align:start position:0% +know like a 12 if a 12pack of Bud Light + + + align:start position:0% +know like a 12 if a 12pack of Bud Light +cost 10 bucks it's like they went from + + align:start position:0% +cost 10 bucks it's like they went from + + + align:start position:0% +cost 10 bucks it's like they went from +10 to 11 the 20 packs it seems like the + + align:start position:0% +10 to 11 the 20 packs it seems like the + + + align:start position:0% +10 to 11 the 20 packs it seems like the +the 30 packs it seem like they went from + + align:start position:0% +the 30 packs it seem like they went from + + + align:start position:0% +the 30 packs it seem like they went from +from 18 to 19 but it's basically like + + align:start position:0% +from 18 to 19 but it's basically like + + + align:start position:0% +from 18 to 19 but it's basically like +prices go up by 5% on average but 10% on + + align:start position:0% +prices go up by 5% on average but 10% on + + + align:start position:0% +prices go up by 5% on average but 10% on +this sort of 12pack of the standard + + align:start position:0% +this sort of 12pack of the standard + + + align:start position:0% +this sort of 12pack of the standard +Flagship beers okay um so um why does + + align:start position:0% +Flagship beers okay um so um why does + + + align:start position:0% +Flagship beers okay um so um why does +this happen again you know there is sort + + align:start position:0% +this happen again you know there is sort + + + align:start position:0% +this happen again you know there is sort +of a there are three things going on + + align:start position:0% +of a there are three things going on + + + align:start position:0% +of a there are three things going on +here there are costs are presumably + + align:start position:0% +here there are costs are presumably + + + align:start position:0% +here there are costs are presumably +going down because they're now Brewing + + align:start position:0% +going down because they're now Brewing + + + align:start position:0% +going down because they're now Brewing +Kors all over the country um but Miller + + align:start position:0% +Kors all over the country um but Miller + + + align:start position:0% +Kors all over the country um but Miller +Kors has this unilateral incentive to + + align:start position:0% +Kors has this unilateral incentive to + + + align:start position:0% +Kors has this unilateral incentive to +raise its prices because it knows if + + align:start position:0% +raise its prices because it knows if + + + align:start position:0% +raise its prices because it knows if +someone goes in to buy Kors light and + + align:start position:0% +someone goes in to buy Kors light and + + + align:start position:0% +someone goes in to buy Kors light and +the price is now higher than they expect + + align:start position:0% +the price is now higher than they expect + + + align:start position:0% +the price is now higher than they expect +they may switch to Miller Light and + + align:start position:0% +they may switch to Miller Light and + + + align:start position:0% +they may switch to Miller Light and +that's not a bad thing anymore um and + + align:start position:0% +that's not a bad thing anymore um and + + + align:start position:0% +that's not a bad thing anymore um and +then there's this possible collusion + + align:start position:0% +then there's this possible collusion + + + align:start position:0% +then there's this possible collusion +third effect so anyway what do they do + + align:start position:0% +third effect so anyway what do they do + + + align:start position:0% +third effect so anyway what do they do +it's + + align:start position:0% +it's + + + align:start position:0% +it's +random coefficients low at demand uh + + align:start position:0% +random coefficients low at demand uh + + + align:start position:0% +random coefficients low at demand uh +Tobias will tell you more about what + + align:start position:0% +Tobias will tell you more about what + + + align:start position:0% +Tobias will tell you more about what +that means but basically you know your + + align:start position:0% +that means but basically you know your + + + align:start position:0% +that means but basically you know your +utility from buying a brand J of beer if + + align:start position:0% +utility from buying a brand J of beer if + + + align:start position:0% +utility from buying a brand J of beer if +you live in region r at time T is + + align:start position:0% +you live in region r at time T is + + + align:start position:0% +you live in region r at time T is +characteristics of the beers times beta + + align:start position:0% +characteristics of the beers times beta + + + align:start position:0% +characteristics of the beers times beta +minus a disutility from paying for the + + align:start position:0% +minus a disutility from paying for the + + + align:start position:0% +minus a disutility from paying for the +beers plus a bunch of fixed effect the + + align:start position:0% +beers plus a bunch of fixed effect the + + + align:start position:0% +beers plus a bunch of fixed effect the +beer uh brand fixed effect the time + + align:start position:0% +beer uh brand fixed effect the time + + + align:start position:0% +beer uh brand fixed effect the time +fixed effect an unobserved quality of + + align:start position:0% +fixed effect an unobserved quality of + + + align:start position:0% +fixed effect an unobserved quality of +the beer and this sort of idiosyncratic + + align:start position:0% +the beer and this sort of idiosyncratic + + + align:start position:0% +the beer and this sort of idiosyncratic +Epsilon like like in the hotelling model + + align:start position:0% +Epsilon like like in the hotelling model + + + align:start position:0% +Epsilon like like in the hotelling model +some people like Kors relative to Bud + + align:start position:0% +some people like Kors relative to Bud + + + align:start position:0% +some people like Kors relative to Bud +wise or just taste wise um what's + + align:start position:0% +wise or just taste wise um what's + + + align:start position:0% +wise or just taste wise um what's +different from the standard loit model + + align:start position:0% +different from the standard loit model + + + align:start position:0% +different from the standard loit model +is it's a random coefficients where the + + align:start position:0% +is it's a random coefficients where the + + + align:start position:0% +is it's a random coefficients where the +different people have different + + align:start position:0% +different people have different + + + align:start position:0% +different people have different +preferences over the + + align:start position:0% +preferences over the + + + align:start position:0% +preferences over the +characteristics and some people are more + + align:start position:0% +characteristics and some people are more + + + align:start position:0% +characteristics and some people are more +price sensitive and some people are less + + align:start position:0% +price sensitive and some people are less + + + align:start position:0% +price sensitive and some people are less +price sensitive so the random + + align:start position:0% +price sensitive so the random + + + align:start position:0% +price sensitive so the random +coefficients mean that not everyone has + + align:start position:0% +coefficients mean that not everyone has + + + align:start position:0% +coefficients mean that not everyone has +the same + + align:start position:0% +the same + + + align:start position:0% +the same +coefficients you know some people like + + align:start position:0% +coefficients you know some people like + + + align:start position:0% +coefficients you know some people like +hoppiness and some people don't like + + align:start position:0% +hoppiness and some people don't like + + + align:start position:0% +hoppiness and some people don't like +hoppiness some people dislike paying + + align:start position:0% +hoppiness some people dislike paying + + + align:start position:0% +hoppiness some people dislike paying +money other people don't care care so + + align:start position:0% +money other people don't care care so + + + align:start position:0% +money other people don't care care so +much about how much they're paying okay + + align:start position:0% +much about how much they're paying okay + + + align:start position:0% +much about how much they're paying okay +they estimate this model they have some + + align:start position:0% +they estimate this model they have some + + + align:start position:0% +they estimate this model they have some +instruments for price I will skip over + + align:start position:0% +instruments for price I will skip over + + + align:start position:0% +instruments for price I will skip over +but they find a bunch of charts like + + align:start position:0% +but they find a bunch of charts like + + + align:start position:0% +but they find a bunch of charts like +this so this chart says um these are + + align:start position:0% +this so this chart says um these are + + + align:start position:0% +this so this chart says um these are +price eloc it says if you raise the + + align:start position:0% +price eloc it says if you raise the + + + align:start position:0% +price eloc it says if you raise the +price of Budweiser by 1% sales of + + align:start position:0% +price of Budweiser by 1% sales of + + + align:start position:0% +price of Budweiser by 1% sales of +Budweiser go down by + + align:start position:0% +Budweiser go down by + + + align:start position:0% +Budweiser go down by +4.4% or sales of Bud Light but then + + align:start position:0% +4.4% or sales of Bud Light but then + + + align:start position:0% +4.4% or sales of Bud Light but then +people will buy other things and so in + + align:start position:0% +people will buy other things and so in + + + align:start position:0% +people will buy other things and so in +particular Kors Budweiser sales will go + + align:start position:0% +particular Kors Budweiser sales will go + + + align:start position:0% +particular Kors Budweiser sales will go +up by 0.3% cor sales by over + + align:start position:0% +up by 0.3% cor sales by over + + + align:start position:0% +up by 0.3% cor sales by over +36% Coors Light sales will go up by 351 + + align:start position:0% +36% Coors Light sales will go up by 351 + + + align:start position:0% +36% Coors Light sales will go up by 351 +per Corona sales will go up by + + align:start position:0% +per Corona sales will go up by + + + align:start position:0% +per Corona sales will go up by +2279 we have this sort of substitution + + align:start position:0% +2279 we have this sort of substitution + + + align:start position:0% +2279 we have this sort of substitution +Matrix they've + + align:start position:0% +Matrix they've + + + align:start position:0% +Matrix they've +estimated and then they say you know + + align:start position:0% +estimated and then they say you know + + + align:start position:0% +estimated and then they say you know +it's a two-step estimation first we + + align:start position:0% +it's a two-step estimation first we + + + align:start position:0% +it's a two-step estimation first we +estimate demand to find all the + + align:start position:0% +estimate demand to find all the + + + align:start position:0% +estimate demand to find all the +elasticities then we say what's going to + + align:start position:0% +elasticities then we say what's going to + + + align:start position:0% +elasticities then we say what's going to +happen What would happen under the + + align:start position:0% +happen What would happen under the + + + align:start position:0% +happen What would happen under the +different um models of + + align:start position:0% +different um models of + + + align:start position:0% +different um models of +behavior and let me see two things I + + align:start position:0% +behavior and let me see two things I + + + align:start position:0% +behavior and let me see two things I +want to say one thing they find is that + + align:start position:0% +want to say one thing they find is that + + + align:start position:0% +want to say one thing they find is that +you know they estimate which Kappa model + + align:start position:0% +you know they estimate which Kappa model + + + align:start position:0% +you know they estimate which Kappa model +best fits the data and they find that in + + align:start position:0% +best fits the data and they find that in + + + align:start position:0% +best fits the data and they find that in +the post period kappas of like 0.25 to + + align:start position:0% +the post period kappas of like 0.25 to + + + align:start position:0% +the post period kappas of like 0.25 to +37 best fit the data so it's as if the + + align:start position:0% +37 best fit the data so it's as if the + + + align:start position:0% +37 best fit the data so it's as if the +firms Budweiser and Miller are putting + + align:start position:0% +firms Budweiser and Miller are putting + + + align:start position:0% +firms Budweiser and Miller are putting +weight on each other's prices and + + align:start position:0% +weight on each other's prices and + + + align:start position:0% +weight on each other's prices and +starting to price higher than seems + + align:start position:0% +starting to price higher than seems + + + align:start position:0% +starting to price higher than seems +optimal after the + + align:start position:0% + + + + align:start position:0% + +merger and um here's the sort of + + align:start position:0% +merger and um here's the sort of + + + align:start position:0% +merger and um here's the sort of +counterfactual so this is what beer + + align:start position:0% +counterfactual so this is what beer + + + align:start position:0% +counterfactual so this is what beer +prices of 12 so 12 packs were like nine + + align:start position:0% +prices of 12 so 12 packs were like nine + + + align:start position:0% +prices of 12 so 12 packs were like nine +bucks or whatever before the merger so + + align:start position:0% +bucks or whatever before the merger so + + + align:start position:0% +bucks or whatever before the merger so +we have this long-term trend of + + align:start position:0% +we have this long-term trend of + + + align:start position:0% +we have this long-term trend of +declining prices of 12 packs of cheap + + align:start position:0% +declining prices of 12 packs of cheap + + + align:start position:0% +declining prices of 12 packs of cheap +beer they think absent the merger it + + align:start position:0% +beer they think absent the merger it + + + align:start position:0% +beer they think absent the merger it +would have continued along this path + + align:start position:0% +would have continued along this path + + + align:start position:0% +would have continued along this path +with some Rises and Falls um I don't + + align:start position:0% +with some Rises and Falls um I don't + + + align:start position:0% +with some Rises and Falls um I don't +know if that's due to costs but then we + + align:start position:0% +know if that's due to costs but then we + + + align:start position:0% +know if that's due to costs but then we +have three things happening the first is + + align:start position:0% +have three things happening the first is + + + align:start position:0% +have three things happening the first is +this unilateral incentive of Miller Kors + + align:start position:0% +this unilateral incentive of Miller Kors + + + align:start position:0% +this unilateral incentive of Miller Kors +to raise its prices because it knows + + align:start position:0% +to raise its prices because it knows + + + align:start position:0% +to raise its prices because it knows +that customers it loses when it raises + + align:start position:0% +that customers it loses when it raises + + + align:start position:0% +that customers it loses when it raises +the price of Coors go to Miller and + + align:start position:0% +the price of Coors go to Miller and + + + align:start position:0% +the price of Coors go to Miller and +that's no longer a bad thing um that + + align:start position:0% +that's no longer a bad thing um that + + + align:start position:0% +that's no longer a bad thing um that +would cause prices to go up for this + + align:start position:0% +would cause prices to go up for this + + + align:start position:0% +would cause prices to go up for this +much but then there were savings from + + align:start position:0% +much but then there were savings from + + + align:start position:0% +much but then there were savings from +CES being cheaper to produce and they + + align:start position:0% +CES being cheaper to produce and they + + + align:start position:0% +CES being cheaper to produce and they +say that the K savings would have been + + align:start position:0% +say that the K savings would have been + + + align:start position:0% +say that the K savings would have been +enough to offset that Kors was not lying + + align:start position:0% +enough to offset that Kors was not lying + + + align:start position:0% +enough to offset that Kors was not lying +before the merger when they said that + + align:start position:0% +before the merger when they said that + + + align:start position:0% +before the merger when they said that +our costs are going to go down by enough + + align:start position:0% +our costs are going to go down by enough + + + align:start position:0% +our costs are going to go down by enough +that it's going to offset our incentive + + align:start position:0% +that it's going to offset our incentive + + + align:start position:0% +that it's going to offset our incentive +to raise prices and they would sort of + + align:start position:0% +to raise prices and they would sort of + + + align:start position:0% +to raise prices and they would sort of +say the cost savings are this big so + + align:start position:0% +say the cost savings are this big so + + + align:start position:0% +say the cost savings are this big so +that would have caused this to + + align:start position:0% +that would have caused this to + + + align:start position:0% +that would have caused this to +happen however um the third effect is + + align:start position:0% +happen however um the third effect is + + + align:start position:0% +happen however um the third effect is +that it looks like they're now + + align:start position:0% +that it looks like they're now + + + align:start position:0% +that it looks like they're now +coordinating they pricing and that + + align:start position:0% +coordinating they pricing and that + + + align:start position:0% +coordinating they pricing and that +increase in collusion is enough to go + + align:start position:0% +increase in collusion is enough to go + + + align:start position:0% +increase in collusion is enough to go +from these triangles to this line up + + align:start position:0% +from these triangles to this line up + + + align:start position:0% +from these triangles to this line up +here so the arguing is that there are + + align:start position:0% +here so the arguing is that there are + + + align:start position:0% +here so the arguing is that there are +sort of three roughly equally sized + + align:start position:0% +sort of three roughly equally sized + + + align:start position:0% +sort of three roughly equally sized +effect the Miller cor is internalizing + + align:start position:0% +effect the Miller cor is internalizing + + + align:start position:0% +effect the Miller cor is internalizing +it's uh doing multiproduct Monopoly + + align:start position:0% +it's uh doing multiproduct Monopoly + + + align:start position:0% +it's uh doing multiproduct Monopoly +pricing the cost savings on producing Cs + + align:start position:0% +pricing the cost savings on producing Cs + + + align:start position:0% +pricing the cost savings on producing Cs +and the anheiser bush bush Miller + + align:start position:0% +and the anheiser bush bush Miller + + + align:start position:0% +and the anheiser bush bush Miller +Cooperative Behavior All roughly equal + + align:start position:0% +Cooperative Behavior All roughly equal + + + align:start position:0% +Cooperative Behavior All roughly equal +sizes but combining together to cause + + align:start position:0% +sizes but combining together to cause + + + align:start position:0% +sizes but combining together to cause +this increase in the 12 packs + + align:start position:0% +this increase in the 12 packs + + + align:start position:0% +this increase in the 12 packs +okay um anyway I think to sort of + + align:start position:0% +okay um anyway I think to sort of + + + align:start position:0% +okay um anyway I think to sort of +appreciate you know paper has some + + align:start position:0% +appreciate you know paper has some + + + align:start position:0% +appreciate you know paper has some +strengths and weaknesses or whatever to + + align:start position:0% +strengths and weaknesses or whatever to + + + align:start position:0% +strengths and weaknesses or whatever to +appreciate those it's easier after + + align:start position:0% +appreciate those it's easier after + + + align:start position:0% +appreciate those it's easier after +tobias's Monday lecture so I figured I + + align:start position:0% +tobias's Monday lecture so I figured I + + + align:start position:0% +tobias's Monday lecture so I figured I +would just skip those and maybe you can + + align:start position:0% +would just skip those and maybe you can + + + align:start position:0% +would just skip those and maybe you can +sort of go back and reread the paper + + align:start position:0% +sort of go back and reread the paper + + + align:start position:0% +sort of go back and reread the paper +after tobias's talk next Monday and + + align:start position:0% +after tobias's talk next Monday and + + + align:start position:0% +after tobias's talk next Monday and +think about you know what what do we + + align:start position:0% +think about you know what what do we + + + align:start position:0% +think about you know what what do we +think of the various aspects of the + + align:start position:0% +think of the various aspects of the + + + align:start position:0% +think of the various aspects of the +estimation + + align:start position:0% +estimation + + + align:start position:0% +estimation +strategy okay but it it is it is it is a + + align:start position:0% +strategy okay but it it is it is it is a + + + align:start position:0% +strategy okay but it it is it is it is a +breast and hand like idea of estimate + + align:start position:0% +breast and hand like idea of estimate + + + align:start position:0% +breast and hand like idea of estimate +multiple models see which ones fit best + + align:start position:0% +multiple models see which ones fit best + + + align:start position:0% +multiple models see which ones fit best +and sort of that's how I determine how + + align:start position:0% +and sort of that's how I determine how + + + align:start position:0% +and sort of that's how I determine how +how firms are + + align:start position:0% +how firms are + + + align:start position:0% +how firms are +behaving okay any + + align:start position:0% +behaving okay any + + + align:start position:0% +behaving okay any +questions okay then we are done uh I + + align:start position:0% +questions okay then we are done uh I + + + align:start position:0% +questions okay then we are done uh I +guess I get a I get a week off um Tobias + + align:start position:0% +guess I get a I get a week off um Tobias + + + align:start position:0% +guess I get a I get a week off um Tobias +is GNA be here um the G gandan Novo is + + align:start position:0% +is GNA be here um the G gandan Novo is + + + align:start position:0% +is GNA be here um the G gandan Novo is +published in like a whatever Handbook of + + align:start position:0% +published in like a whatever Handbook of + + + align:start position:0% +published in like a whatever Handbook of +IO that's expensive and hard to find but + + align:start position:0% +IO that's expensive and hard to find but + + + align:start position:0% +IO that's expensive and hard to find but +if you look at the same exact document + + align:start position:0% +if you look at the same exact document + + + align:start position:0% +if you look at the same exact document +as NBR working paper + + align:start position:0% +as NBR working paper + + + align:start position:0% +as NBR working paper +29257 so if you look at that version uh + + align:start position:0% +29257 so if you look at that version uh + + + align:start position:0% +29257 so if you look at that version uh +that's easy to find for \ No newline at end of file diff --git a/Dqko567cE9I.txt b/Dqko567cE9I.txt new file mode 100644 index 0000000000000000000000000000000000000000..f6a054b80e9e471ec2e8ef99e956276e48c5b7b0 --- /dev/null +++ b/Dqko567cE9I.txt @@ -0,0 +1,13416 @@ +align:start position:0% + +all right so let's + + align:start position:0% +all right so let's + + + align:start position:0% +all right so let's +get started are there any questions from + + align:start position:0% +get started are there any questions from + + + align:start position:0% +get started are there any questions from +last time + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +as you are no doubt well aware + + align:start position:0% +as you are no doubt well aware + + + align:start position:0% +as you are no doubt well aware +this is the last lecture i'm going to + + align:start position:0% +this is the last lecture i'm going to + + + align:start position:0% +this is the last lecture i'm going to +give + + align:start position:0% +give + + + align:start position:0% +give +the + + align:start position:0% +the + + + align:start position:0% +the +the exam is a week from + + align:start position:0% +the exam is a week from + + + align:start position:0% +the exam is a week from +yesterday on monday + + align:start position:0% +yesterday on monday + + + align:start position:0% +yesterday on monday +so what i want to do today is is to + + align:start position:0% +so what i want to do today is is to + + + align:start position:0% +so what i want to do today is is to +review + + align:start position:0% +review + + + align:start position:0% +review +the material and see if there are + + align:start position:0% +the material and see if there are + + + align:start position:0% +the material and see if there are +questions + + align:start position:0% +questions + + + align:start position:0% +questions +so today we're covering the material + + align:start position:0% +so today we're covering the material + + + align:start position:0% +so today we're covering the material +from + + align:start position:0% +from + + + align:start position:0% +from +lectures + + align:start position:0% +lectures + + + align:start position:0% +lectures +16 on 16 through 21 + + align:start position:0% +16 on 16 through 21 + + + align:start position:0% +16 on 16 through 21 +and normally you know the exam would + + align:start position:0% +and normally you know the exam would + + + align:start position:0% +and normally you know the exam would +cover 16 through 21 and i could have + + align:start position:0% +cover 16 through 21 and i could have + + + align:start position:0% +cover 16 through 21 and i could have +written that in there i am just trying + + align:start position:0% +written that in there i am just trying + + + align:start position:0% +written that in there i am just trying +to avoid confusion though because the + + align:start position:0% +to avoid confusion though because the + + + align:start position:0% +to avoid confusion though because the +course is cumulative and one thing + + align:start position:0% +course is cumulative and one thing + + + align:start position:0% +course is cumulative and one thing +builds on another you know essentially + + align:start position:0% +builds on another you know essentially + + + align:start position:0% +builds on another you know essentially +it will focus + + align:start position:0% +it will focus + + + align:start position:0% +it will focus +on + + align:start position:0% +on + + + align:start position:0% +on +16 onwards but you should be + + align:start position:0% +16 onwards but you should be + + + align:start position:0% +16 onwards but you should be +by now very familiar with the earlier + + align:start position:0% +by now very familiar with the earlier + + + align:start position:0% +by now very familiar with the earlier +material and some of it may come up + + align:start position:0% +material and some of it may come up + + + align:start position:0% +material and some of it may come up +so this is just to prevent me from + + align:start position:0% +so this is just to prevent me from + + + align:start position:0% +so this is just to prevent me from +misleading you if i said it was only on + + align:start position:0% +misleading you if i said it was only on + + + align:start position:0% +misleading you if i said it was only on +the last one third of the class you know + + align:start position:0% +the last one third of the class you know + + + align:start position:0% +the last one third of the class you know +then you + + align:start position:0% +then you + + + align:start position:0% +then you +you may get lulled into uh thinking that + + align:start position:0% +you may get lulled into uh thinking that + + + align:start position:0% +you may get lulled into uh thinking that +it's quite narrowly about only those + + align:start position:0% +it's quite narrowly about only those + + + align:start position:0% +it's quite narrowly about only those +things as opposed to + + align:start position:0% +things as opposed to + + + align:start position:0% +things as opposed to +the things on which it is building + + align:start position:0% +the things on which it is building + + + align:start position:0% +the things on which it is building +anyway just one word of clarification + + align:start position:0% +anyway just one word of clarification + + + align:start position:0% +anyway just one word of clarification +and again it's only + + align:start position:0% +and again it's only + + + align:start position:0% +and again it's only +the third midterm it doesn't count + + align:start position:0% +the third midterm it doesn't count + + + align:start position:0% +the third midterm it doesn't count +anything special in terms of + + align:start position:0% +anything special in terms of + + + align:start position:0% +anything special in terms of +your grade let's see + + align:start position:0% +your grade let's see + + + align:start position:0% +your grade let's see +so last time we talked about money + + align:start position:0% +so last time we talked about money + + + align:start position:0% +so last time we talked about money +uh bitcoin in particular + + align:start position:0% +uh bitcoin in particular + + + align:start position:0% +uh bitcoin in particular +and i singled out two questions + + align:start position:0% +and i singled out two questions + + + align:start position:0% +and i singled out two questions +one of which i kind of mentioned in + + align:start position:0% +one of which i kind of mentioned in + + + align:start position:0% +one of which i kind of mentioned in +class but let's get you guys engaged in + + align:start position:0% +class but let's get you guys engaged in + + + align:start position:0% +class but let's get you guys engaged in +this + + align:start position:0% +this + + + align:start position:0% +this +a central banker namely dudley at new + + align:start position:0% +a central banker namely dudley at new + + + align:start position:0% +a central banker namely dudley at new +york fed + + align:start position:0% +york fed + + + align:start position:0% +york fed +has heard to say that unlike fiat money + + align:start position:0% +has heard to say that unlike fiat money + + + align:start position:0% +has heard to say that unlike fiat money +bitcoin's positive value in markets is + + align:start position:0% +bitcoin's positive value in markets is + + + align:start position:0% +bitcoin's positive value in markets is +just a bubble + + align:start position:0% +just a bubble + + + align:start position:0% +just a bubble +and with wild fluctuations so bitcoin + + align:start position:0% +and with wild fluctuations so bitcoin + + + align:start position:0% +and with wild fluctuations so bitcoin +should be regulated if not banned + + align:start position:0% +should be regulated if not banned + + + align:start position:0% +should be regulated if not banned +altogether + + align:start position:0% +altogether + + + align:start position:0% +altogether +and then + + align:start position:0% +and then + + + align:start position:0% +and then +it says discuss this statement using the + + align:start position:0% +it says discuss this statement using the + + + align:start position:0% +it says discuss this statement using the +tools you have learned in the class + + align:start position:0% +tools you have learned in the class + + + align:start position:0% +tools you have learned in the class +so could i get some volunteers to answer + + align:start position:0% +so could i get some volunteers to answer + + + align:start position:0% +so could i get some volunteers to answer +that question + + align:start position:0% + + + + align:start position:0% + +to be honest and pretty unsure but i do + + align:start position:0% +to be honest and pretty unsure but i do + + + align:start position:0% +to be honest and pretty unsure but i do +remember we talked about how you can + + align:start position:0% +remember we talked about how you can + + + align:start position:0% +remember we talked about how you can +have equilibrium with bubbles + + align:start position:0% +have equilibrium with bubbles + + + align:start position:0% +have equilibrium with bubbles +um so they're not like inherently + + align:start position:0% +um so they're not like inherently + + + align:start position:0% +um so they're not like inherently +something that you have to regulate it's + + align:start position:0% +something that you have to regulate it's + + + align:start position:0% +something that you have to regulate it's +possible to still have an equilibrium + + align:start position:0% +possible to still have an equilibrium + + + align:start position:0% +possible to still have an equilibrium +despite bitcoin being overvalued + + align:start position:0% +despite bitcoin being overvalued + + + align:start position:0% +despite bitcoin being overvalued +right + + align:start position:0% +right + + + align:start position:0% +right +that's true + + align:start position:0% +that's true + + + align:start position:0% +that's true +um + + align:start position:0% + + + + align:start position:0% + +the question actually asks about fiat + + align:start position:0% +the question actually asks about fiat + + + align:start position:0% +the question actually asks about fiat +money i kind of slipped that in there + + align:start position:0% +money i kind of slipped that in there + + + align:start position:0% +money i kind of slipped that in there +that unlike fiat money bitcoin + + align:start position:0% +that unlike fiat money bitcoin + + + align:start position:0% +that unlike fiat money bitcoin +is just a bubble + + align:start position:0% +is just a bubble + + + align:start position:0% +is just a bubble +can you maybe respond to that part + + align:start position:0% + + + + align:start position:0% + +maria or anyone else for that matter + + align:start position:0% + + + + align:start position:0% + +i mean i guess that is somewhat true as + + align:start position:0% +i mean i guess that is somewhat true as + + + align:start position:0% +i mean i guess that is somewhat true as +in it's not tied to like a tangible + + align:start position:0% +in it's not tied to like a tangible + + + align:start position:0% +in it's not tied to like a tangible +um kind of asset + + align:start position:0% +um kind of asset + + + align:start position:0% +um kind of asset +underlying it + + align:start position:0% +underlying it + + + align:start position:0% +underlying it +i'm not sure what exactly you're looking + + align:start position:0% +i'm not sure what exactly you're looking + + + align:start position:0% +i'm not sure what exactly you're looking +for here though + + align:start position:0% +for here though + + + align:start position:0% +for here though +okay + + align:start position:0% +okay + + + align:start position:0% +okay +fiat money is a bubble + + align:start position:0% +fiat money is a bubble + + + align:start position:0% +fiat money is a bubble +it's a bubble the way that + + align:start position:0% +it's a bubble the way that + + + align:start position:0% +it's a bubble the way that +bitcoin is potentially a bubble + + align:start position:0% +bitcoin is potentially a bubble + + + align:start position:0% +bitcoin is potentially a bubble +uh fiat money used to be backed by gold + + align:start position:0% +uh fiat money used to be backed by gold + + + align:start position:0% +uh fiat money used to be backed by gold +so there if you didn't want to hold the + + align:start position:0% +so there if you didn't want to hold the + + + align:start position:0% +so there if you didn't want to hold the +notes you could go to the federal + + align:start position:0% +notes you could go to the federal + + + align:start position:0% +notes you could go to the federal +reserve and + + align:start position:0% +reserve and + + + align:start position:0% +reserve and +and demand a real commodity + + align:start position:0% +and demand a real commodity + + + align:start position:0% +and demand a real commodity +so then it would not + + align:start position:0% +so then it would not + + + align:start position:0% +so then it would not +potentially be a bubble because + + align:start position:0% +potentially be a bubble because + + + align:start position:0% +potentially be a bubble because +it was just a certificate for a + + align:start position:0% +it was just a certificate for a + + + align:start position:0% +it was just a certificate for a +commodity that would have real value + + align:start position:0% +commodity that would have real value + + + align:start position:0% +commodity that would have real value +but when nixon broke the link to gold + + align:start position:0% +but when nixon broke the link to gold + + + align:start position:0% +but when nixon broke the link to gold +then fiat money is just + + align:start position:0% +then fiat money is just + + + align:start position:0% +then fiat money is just +pieces of paper + + align:start position:0% +pieces of paper + + + align:start position:0% +pieces of paper +and nevertheless it has value so it + + align:start position:0% +and nevertheless it has value so it + + + align:start position:0% +and nevertheless it has value so it +so the point of the lecture was that + + align:start position:0% +so the point of the lecture was that + + + align:start position:0% +so the point of the lecture was that +fiat money is a bubble + + align:start position:0% +fiat money is a bubble + + + align:start position:0% +fiat money is a bubble +now we used yeah the word bubble + + align:start position:0% +now we used yeah the word bubble + + + align:start position:0% +now we used yeah the word bubble +is almost deliberately provocative + + align:start position:0% +is almost deliberately provocative + + + align:start position:0% +is almost deliberately provocative +because it kind of sounds bad + + align:start position:0% + + + + align:start position:0% + +but dudley who made this statement + + align:start position:0% +but dudley who made this statement + + + align:start position:0% +but dudley who made this statement +seem to have not + + align:start position:0% +seem to have not + + + align:start position:0% +seem to have not +let's say forgotten seems to have + + align:start position:0% +let's say forgotten seems to have + + + align:start position:0% +let's say forgotten seems to have +forgotten + + align:start position:0% +forgotten + + + align:start position:0% +forgotten +that his domain fiat money is + + align:start position:0% +that his domain fiat money is + + + align:start position:0% +that his domain fiat money is +potentially fragile as well + + align:start position:0% +potentially fragile as well + + + align:start position:0% +potentially fragile as well +now the difference is you know the + + align:start position:0% +now the difference is you know the + + + align:start position:0% +now the difference is you know the +federal reserve behaves itself by and + + align:start position:0% +federal reserve behaves itself by and + + + align:start position:0% +federal reserve behaves itself by and +large + + align:start position:0% +large + + + align:start position:0% +large +hard not to jump in with some + + align:start position:0% +hard not to jump in with some + + + align:start position:0% +hard not to jump in with some +parenthetical comments on that but let's + + align:start position:0% +parenthetical comments on that but let's + + + align:start position:0% +parenthetical comments on that but let's +argue that that's the case so then with + + align:start position:0% +argue that that's the case so then with + + + align:start position:0% +argue that that's the case so then with +forward guidance and so on + + align:start position:0% +forward guidance and so on + + + align:start position:0% +forward guidance and so on +noah no one is expecting high inflation + + align:start position:0% +noah no one is expecting high inflation + + + align:start position:0% +noah no one is expecting high inflation +which + + align:start position:0% +which + + + align:start position:0% +which +you know would lead to speculations + + align:start position:0% +you know would lead to speculations + + + align:start position:0% +you know would lead to speculations +about how much + + align:start position:0% +about how much + + + align:start position:0% +about how much +the money is really worth and so on so + + align:start position:0% +the money is really worth and so on so + + + align:start position:0% +the money is really worth and so on so +that whereas with bitcoin you know we + + align:start position:0% +that whereas with bitcoin you know we + + + align:start position:0% +that whereas with bitcoin you know we +don't have a long history + + align:start position:0% +don't have a long history + + + align:start position:0% +don't have a long history +we haven't set expectations and so on so + + align:start position:0% +we haven't set expectations and so on so + + + align:start position:0% +we haven't set expectations and so on so +there are differences between the two + + align:start position:0% +there are differences between the two + + + align:start position:0% +there are differences between the two +but in a in a model + + align:start position:0% +but in a in a model + + + align:start position:0% +but in a in a model +it's pretty hard to make a distinction + + align:start position:0% +it's pretty hard to make a distinction + + + align:start position:0% +it's pretty hard to make a distinction +because they're both + + align:start position:0% +because they're both + + + align:start position:0% +because they're both +essentially worthless even though they + + align:start position:0% +essentially worthless even though they + + + align:start position:0% +essentially worthless even though they +have value + + align:start position:0% + + + + align:start position:0% + +so that's what i was looking for + + align:start position:0% + + + + align:start position:0% + +the second question + + align:start position:0% +the second question + + + align:start position:0% +the second question +should currency pay interest + + align:start position:0% + + + + align:start position:0% + +or more specifically + + align:start position:0% +or more specifically + + + align:start position:0% +or more specifically +what did we learn in the lecture about + + align:start position:0% +what did we learn in the lecture about + + + align:start position:0% +what did we learn in the lecture about +that + + align:start position:0% + + + + align:start position:0% + +is it ready to see a non-zero price of + + align:start position:0% +is it ready to see a non-zero price of + + + align:start position:0% +is it ready to see a non-zero price of +of a currency + + align:start position:0% +of a currency + + + align:start position:0% +of a currency +because um and remember we + + align:start position:0% +because um and remember we + + + align:start position:0% +because um and remember we +we say that cash + + align:start position:0% +we say that cash + + + align:start position:0% +we say that cash +has positive value because um it can be + + align:start position:0% +has positive value because um it can be + + + align:start position:0% +has positive value because um it can be +used to pay taxes and + + align:start position:0% +used to pay taxes and + + + align:start position:0% +used to pay taxes and +there's a cash in advance so + + align:start position:0% +there's a cash in advance so + + + align:start position:0% +there's a cash in advance so +um + + align:start position:0% +um + + + align:start position:0% +um +so + + align:start position:0% +so + + + align:start position:0% +so +um so so if the price is equal to zero + + align:start position:0% +um so so if the price is equal to zero + + + align:start position:0% +um so so if the price is equal to zero +um + + align:start position:0% +um + + + align:start position:0% +um +then + + align:start position:0% +then + + + align:start position:0% +then +the + + align:start position:0% +the + + + align:start position:0% +the +no nobody will demand the + + align:start position:0% +no nobody will demand the + + + align:start position:0% +no nobody will demand the +demand currency right + + align:start position:0% + + + + align:start position:0% + +uh yeah you're + + align:start position:0% +uh yeah you're + + + align:start position:0% +uh yeah you're +speaking to the levels + + align:start position:0% +speaking to the levels + + + align:start position:0% +speaking to the levels +so the point of having cash in advance + + align:start position:0% +so the point of having cash in advance + + + align:start position:0% +so the point of having cash in advance +or taxes and so on is that money would + + align:start position:0% +or taxes and so on is that money would + + + align:start position:0% +or taxes and so on is that money would +always have value because + + align:start position:0% +always have value because + + + align:start position:0% +always have value because +there's something you need to do with it + + align:start position:0% +there's something you need to do with it + + + align:start position:0% +there's something you need to do with it +either buy stuff or pay taxes in it + + align:start position:0% +either buy stuff or pay taxes in it + + + align:start position:0% +either buy stuff or pay taxes in it +but this question + + align:start position:0% +but this question + + + align:start position:0% +but this question +interest implies something about how the + + align:start position:0% +interest implies something about how the + + + align:start position:0% +interest implies something about how the +price of money is changing over time + + align:start position:0% +price of money is changing over time + + + align:start position:0% +price of money is changing over time +or + + align:start position:0% +or + + + align:start position:0% +or +or that currency you know + + align:start position:0% + + + + align:start position:0% + +how can i put this the mechanical way to + + align:start position:0% +how can i put this the mechanical way to + + + align:start position:0% +how can i put this the mechanical way to +get currency to bear interest even + + align:start position:0% +get currency to bear interest even + + + align:start position:0% +get currency to bear interest even +though you can't take it necessarily to + + align:start position:0% +though you can't take it necessarily to + + + align:start position:0% +though you can't take it necessarily to +a bank + + align:start position:0% +a bank + + + align:start position:0% +a bank +and exchange it for more money + + align:start position:0% +and exchange it for more money + + + align:start position:0% +and exchange it for more money +is is to have + + align:start position:0% +is is to have + + + align:start position:0% +is is to have +the thing that money exchanges against + + align:start position:0% +the thing that money exchanges against + + + align:start position:0% +the thing that money exchanges against +um + + align:start position:0% +um + + + align:start position:0% +um +be lowering in in price in other words + + align:start position:0% +be lowering in in price in other words + + + align:start position:0% +be lowering in in price in other words +a deflation + + align:start position:0% +a deflation + + + align:start position:0% +a deflation +where the nominal price level is going + + align:start position:0% +where the nominal price level is going + + + align:start position:0% +where the nominal price level is going +down + + align:start position:0% +down + + + align:start position:0% +down +means that you can buy more goods with + + align:start position:0% +means that you can buy more goods with + + + align:start position:0% +means that you can buy more goods with +money tomorrow than you can buy with it + + align:start position:0% +money tomorrow than you can buy with it + + + align:start position:0% +money tomorrow than you can buy with it +today and that's effectively like paying + + align:start position:0% +today and that's effectively like paying + + + align:start position:0% +today and that's effectively like paying +interest + + align:start position:0% +interest + + + align:start position:0% +interest +the way to remember that is inflation is + + align:start position:0% +the way to remember that is inflation is + + + align:start position:0% +the way to remember that is inflation is +bad obviously because the purchasing + + align:start position:0% +bad obviously because the purchasing + + + align:start position:0% +bad obviously because the purchasing +power of money is going down + + align:start position:0% +power of money is going down + + + align:start position:0% +power of money is going down +it takes more and more money to buy + + align:start position:0% +it takes more and more money to buy + + + align:start position:0% +it takes more and more money to buy +goods with deflation + + align:start position:0% +goods with deflation + + + align:start position:0% +goods with deflation +the purchasing power of money is going + + align:start position:0% +the purchasing power of money is going + + + align:start position:0% +the purchasing power of money is going +up + + align:start position:0% +up + + + align:start position:0% +up +so that's effectively a way to pay + + align:start position:0% +so that's effectively a way to pay + + + align:start position:0% +so that's effectively a way to pay +interest and + + align:start position:0% +interest and + + + align:start position:0% +interest and +what did we learn in class about whether + + align:start position:0% +what did we learn in class about whether + + + align:start position:0% +what did we learn in class about whether +or not + + align:start position:0% +or not + + + align:start position:0% +or not +it's optimal to engineer that + + align:start position:0% + + + + align:start position:0% + +any volunteers + + align:start position:0% + + + + align:start position:0% + +yeah sorry i know it's the end of the + + align:start position:0% +yeah sorry i know it's the end of the + + + align:start position:0% +yeah sorry i know it's the end of the +term and you're all very very busy + + align:start position:0% + + + + align:start position:0% + +so the answer was + + align:start position:0% +so the answer was + + + align:start position:0% +so the answer was +in that model of money with spatially + + align:start position:0% +in that model of money with spatially + + + align:start position:0% +in that model of money with spatially +separated agents + + align:start position:0% +separated agents + + + align:start position:0% +separated agents +uh there was a monetary equilibrium + + align:start position:0% +uh there was a monetary equilibrium + + + align:start position:0% +uh there was a monetary equilibrium +with a constant price level but it was + + align:start position:0% +with a constant price level but it was + + + align:start position:0% +with a constant price level but it was +not pareto optimal + + align:start position:0% +not pareto optimal + + + align:start position:0% +not pareto optimal +and to get to one of the pareto optimal + + align:start position:0% +and to get to one of the pareto optimal + + + align:start position:0% +and to get to one of the pareto optimal +allocations + + align:start position:0% +allocations + + + align:start position:0% +allocations +it was necessary to engineer this kind + + align:start position:0% +it was necessary to engineer this kind + + + align:start position:0% +it was necessary to engineer this kind +of deflation + + align:start position:0% + + + + align:start position:0% + +so that's an example of paying interest + + align:start position:0% +so that's an example of paying interest + + + align:start position:0% +so that's an example of paying interest +on money + + align:start position:0% +on money + + + align:start position:0% +on money +is actually + + align:start position:0% +is actually + + + align:start position:0% +is actually +something the federal reserve should be + + align:start position:0% +something the federal reserve should be + + + align:start position:0% +something the federal reserve should be +doing + + align:start position:0% +doing + + + align:start position:0% +doing +because i hope it's coming back to you + + align:start position:0% +because i hope it's coming back to you + + + align:start position:0% +because i hope it's coming back to you +now + + align:start position:0% +now + + + align:start position:0% +now +okay + + align:start position:0% +okay + + + align:start position:0% +okay +anyway those were the two main + + align:start position:0% +anyway those were the two main + + + align:start position:0% +anyway those were the two main +ingredients of this + + align:start position:0% +ingredients of this + + + align:start position:0% +ingredients of this +last very last lecture on bubbles so i + + align:start position:0% +last very last lecture on bubbles so i + + + align:start position:0% +last very last lecture on bubbles so i +probably won't + + align:start position:0% +probably won't + + + align:start position:0% +probably won't +if history is any god i won't have time + + align:start position:0% +if history is any god i won't have time + + + align:start position:0% +if history is any god i won't have time +to + + align:start position:0% +to + + + align:start position:0% +to +open up lecture this last lecture 21 and + + align:start position:0% +open up lecture this last lecture 21 and + + + align:start position:0% +open up lecture this last lecture 21 and +review it but those were the + + align:start position:0% +review it but those were the + + + align:start position:0% +review it but those were the +the two principal components + + align:start position:0% +the two principal components + + + align:start position:0% +the two principal components +namely + + align:start position:0% +namely + + + align:start position:0% +namely +money as a bubble and uh + + align:start position:0% +money as a bubble and uh + + + align:start position:0% +money as a bubble and uh +and this policy aspect + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +so + + align:start position:0% +so + + + align:start position:0% +so +again the study guide should help you + + align:start position:0% +again the study guide should help you + + + align:start position:0% +again the study guide should help you +prepare for the exam + + align:start position:0% +prepare for the exam + + + align:start position:0% +prepare for the exam +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +and now we're ready to + + align:start position:0% +and now we're ready to + + + align:start position:0% +and now we're ready to +to review + + align:start position:0% +to review + + + align:start position:0% +to review +the lectures + + align:start position:0% +the lectures + + + align:start position:0% +the lectures +there's only six of them + + align:start position:0% +there's only six of them + + + align:start position:0% +there's only six of them +so this material is probably pretty + + align:start position:0% +so this material is probably pretty + + + align:start position:0% +so this material is probably pretty +fresh in your minds i think what i'll do + + align:start position:0% +fresh in your minds i think what i'll do + + + align:start position:0% +fresh in your minds i think what i'll do +rather than obviously i wouldn't have + + align:start position:0% +rather than obviously i wouldn't have + + + align:start position:0% +rather than obviously i wouldn't have +time anyway to go over all the + + align:start position:0% +time anyway to go over all the + + + align:start position:0% +time anyway to go over all the +individual + + align:start position:0% +individual + + + align:start position:0% +individual +slides of each lecture i will try to + + align:start position:0% +slides of each lecture i will try to + + + align:start position:0% +slides of each lecture i will try to +remind you what we did and maybe maybe + + align:start position:0% +remind you what we did and maybe maybe + + + align:start position:0% +remind you what we did and maybe maybe +draw some connections to the other + + align:start position:0% +draw some connections to the other + + + align:start position:0% +draw some connections to the other +lectures and how things are kind of + + align:start position:0% +lectures and how things are kind of + + + align:start position:0% +lectures and how things are kind of +fitting together so this was the lecture + + align:start position:0% +fitting together so this was the lecture + + + align:start position:0% +fitting together so this was the lecture +on the fundamental welfare theorems + + align:start position:0% +on the fundamental welfare theorems + + + align:start position:0% +on the fundamental welfare theorems +namely that competitive equilibria + + align:start position:0% +namely that competitive equilibria + + + align:start position:0% +namely that competitive equilibria +under certain assumptions are pareto + + align:start position:0% +under certain assumptions are pareto + + + align:start position:0% +under certain assumptions are pareto +optimal and any optimum can be supported + + align:start position:0% +optimal and any optimum can be supported + + + align:start position:0% +optimal and any optimum can be supported +with transfers so this lecture was about + + align:start position:0% +with transfers so this lecture was about + + + align:start position:0% +with transfers so this lecture was about +sufficient assumptions and the + + align:start position:0% +sufficient assumptions and the + + + align:start position:0% +sufficient assumptions and the +corresponding proofs + + align:start position:0% +corresponding proofs + + + align:start position:0% +corresponding proofs +and it ended with extensions to + + align:start position:0% +and it ended with extensions to + + + align:start position:0% +and it ended with extensions to +more general commodity spaces so + + align:start position:0% +more general commodity spaces so + + + align:start position:0% +more general commodity spaces so +you may remember that i did this i + + align:start position:0% +you may remember that i did this i + + + align:start position:0% +you may remember that i did this i +showed this back to the earlier lectures + + align:start position:0% +showed this back to the earlier lectures + + + align:start position:0% +showed this back to the earlier lectures +the first part of the course on risk + + align:start position:0% +the first part of the course on risk + + + align:start position:0% +the first part of the course on risk +sharing i showed the income movements of + + align:start position:0% +sharing i showed the income movements of + + + align:start position:0% +sharing i showed the income movements of +households over time and compared to + + align:start position:0% +households over time and compared to + + + align:start position:0% +households over time and compared to +each other and including the consumption + + align:start position:0% +each other and including the consumption + + + align:start position:0% +each other and including the consumption +we noted this gradient here that the + + align:start position:0% +we noted this gradient here that the + + + align:start position:0% +we noted this gradient here that the +average level of consumption is + + align:start position:0% +average level of consumption is + + + align:start position:0% +average level of consumption is +increasing as one moves from landless + + align:start position:0% +increasing as one moves from landless + + + align:start position:0% +increasing as one moves from landless +households to larger + + align:start position:0% +households to larger + + + align:start position:0% +households to larger +landowners in the risk sharing framework + + align:start position:0% +landowners in the risk sharing framework + + + align:start position:0% +landowners in the risk sharing framework +that was related to lambda the pareto + + align:start position:0% +that was related to lambda the pareto + + + align:start position:0% +that was related to lambda the pareto +weight + + align:start position:0% +weight + + + align:start position:0% +weight +and very clearly for certain functional + + align:start position:0% +and very clearly for certain functional + + + align:start position:0% +and very clearly for certain functional +forms it was exactly that parade of + + align:start position:0% +forms it was exactly that parade of + + + align:start position:0% +forms it was exactly that parade of +weight of one household relative to the + + align:start position:0% +weight of one household relative to the + + + align:start position:0% +weight of one household relative to the +others + + align:start position:0% +others + + + align:start position:0% +others +but the + + align:start position:0% +but the + + + align:start position:0% +but the +motivation here was to introduce the + + align:start position:0% +motivation here was to introduce the + + + align:start position:0% +motivation here was to introduce the +welfare theorems so then the the issue + + align:start position:0% +welfare theorems so then the the issue + + + align:start position:0% +welfare theorems so then the the issue +was whether the lambdas that are + + align:start position:0% +was whether the lambdas that are + + + align:start position:0% +was whether the lambdas that are +implicit in that diagram are related to + + align:start position:0% +implicit in that diagram are related to + + + align:start position:0% +implicit in that diagram are related to +wealth + + align:start position:0% +wealth + + + align:start position:0% +wealth +like land holdings and the number of + + align:start position:0% +like land holdings and the number of + + + align:start position:0% +like land holdings and the number of +plow animals and so on + + align:start position:0% +plow animals and so on + + + align:start position:0% +plow animals and so on +so i was sort of anticipating a + + align:start position:0% +so i was sort of anticipating a + + + align:start position:0% +so i was sort of anticipating a +connection between + + align:start position:0% +connection between + + + align:start position:0% +connection between +lambdas as in + + align:start position:0% +lambdas as in + + + align:start position:0% +lambdas as in +the pareto problem of pareto optimal + + align:start position:0% +the pareto problem of pareto optimal + + + align:start position:0% +the pareto problem of pareto optimal +allocations versus the wealth + + align:start position:0% +allocations versus the wealth + + + align:start position:0% +allocations versus the wealth +that may be needed in a competitive + + align:start position:0% +that may be needed in a competitive + + + align:start position:0% +that may be needed in a competitive +equilibrium you'll see that again or be + + align:start position:0% +equilibrium you'll see that again or be + + + align:start position:0% +equilibrium you'll see that again or be +reminded of it momentarily + + align:start position:0% +reminded of it momentarily + + + align:start position:0% +reminded of it momentarily +so the first welfare theorem + + align:start position:0% +so the first welfare theorem + + + align:start position:0% +so the first welfare theorem +is that any price equilibrium + + align:start position:0% +is that any price equilibrium + + + align:start position:0% +is that any price equilibrium +competitive equilibrium including a + + align:start position:0% +competitive equilibrium including a + + + align:start position:0% +competitive equilibrium including a +price equilibrium with transfers is + + align:start position:0% +price equilibrium with transfers is + + + align:start position:0% +price equilibrium with transfers is +pareto optimal under minimal sufficient + + align:start position:0% +pareto optimal under minimal sufficient + + + align:start position:0% +pareto optimal under minimal sufficient +assumptions namely + + align:start position:0% +assumptions namely + + + align:start position:0% +assumptions namely +rational preferences which we haven't + + align:start position:0% +rational preferences which we haven't + + + align:start position:0% +rational preferences which we haven't +reviewed for a while but it was in + + align:start position:0% +reviewed for a while but it was in + + + align:start position:0% +reviewed for a while but it was in +lecture two + + align:start position:0% +lecture two + + + align:start position:0% +lecture two +complete + + align:start position:0% +complete + + + align:start position:0% +complete +transitive + + align:start position:0% +transitive + + + align:start position:0% +transitive +and continuous preferences + + align:start position:0% +and continuous preferences + + + align:start position:0% +and continuous preferences +and local non-satiation with those two + + align:start position:0% +and local non-satiation with those two + + + align:start position:0% +and local non-satiation with those two +assumptions we get this + + align:start position:0% +assumptions we get this + + + align:start position:0% +assumptions we get this +sufficient for this theorem + + align:start position:0% +sufficient for this theorem + + + align:start position:0% +sufficient for this theorem +so this was a picture + + align:start position:0% +so this was a picture + + + align:start position:0% +so this was a picture +in our familiar edgeworth box + + align:start position:0% +in our familiar edgeworth box + + + align:start position:0% +in our familiar edgeworth box +of a competitive equilibrium being + + align:start position:0% +of a competitive equilibrium being + + + align:start position:0% +of a competitive equilibrium being +pareto optimal + + align:start position:0% +pareto optimal + + + align:start position:0% +pareto optimal +uh the proof + + align:start position:0% +uh the proof + + + align:start position:0% +uh the proof +you may remember relied on + + align:start position:0% +you may remember relied on + + + align:start position:0% +you may remember relied on +starting with a given allocation + + align:start position:0% +starting with a given allocation + + + align:start position:0% +starting with a given allocation +the star allocation and then conjuring + + align:start position:0% +the star allocation and then conjuring + + + align:start position:0% +the star allocation and then conjuring +up by contradiction that there might be + + align:start position:0% +up by contradiction that there might be + + + align:start position:0% +up by contradiction that there might be +something pareto improving we prove this + + align:start position:0% +something pareto improving we prove this + + + align:start position:0% +something pareto improving we prove this +little lemma + + align:start position:0% +little lemma + + + align:start position:0% +little lemma +that anything which is weakly better has + + align:start position:0% +that anything which is weakly better has + + + align:start position:0% +that anything which is weakly better has +to cost us at least as much + + align:start position:0% +to cost us at least as much + + + align:start position:0% +to cost us at least as much +and then we just went through the math + + align:start position:0% +and then we just went through the math + + + align:start position:0% +and then we just went through the math +summing up over all the households + + align:start position:0% +summing up over all the households + + + align:start position:0% +summing up over all the households +obviously if it's strictly better for + + align:start position:0% +obviously if it's strictly better for + + + align:start position:0% +obviously if it's strictly better for +some households i prime then it must + + align:start position:0% +some households i prime then it must + + + align:start position:0% +some households i prime then it must +have costed more or otherwise they would + + align:start position:0% +have costed more or otherwise they would + + + align:start position:0% +have costed more or otherwise they would +have chosen so we get in equation one + + align:start position:0% +have chosen so we get in equation one + + + align:start position:0% +have chosen so we get in equation one +the statement about total expenditures + + align:start position:0% +the statement about total expenditures + + + align:start position:0% +the statement about total expenditures +the value of total expenditure summing + + align:start position:0% +the value of total expenditure summing + + + align:start position:0% +the value of total expenditure summing +up over + + align:start position:0% +up over + + + align:start position:0% +up over +all the households i'm going quickly now + + align:start position:0% +all the households i'm going quickly now + + + align:start position:0% +all the households i'm going quickly now +we used profit maximization we coupled + + align:start position:0% +we used profit maximization we coupled + + + align:start position:0% +we used profit maximization we coupled +equations one and two + + align:start position:0% +equations one and two + + + align:start position:0% +equations one and two +to get a statement about resource + + align:start position:0% +to get a statement about resource + + + align:start position:0% +to get a statement about resource +constraints and at the bottom line + + align:start position:0% +constraints and at the bottom line + + + align:start position:0% +constraints and at the bottom line +concluded that this alternative + + align:start position:0% +concluded that this alternative + + + align:start position:0% +concluded that this alternative +pareto-dominating allocation would not + + align:start position:0% +pareto-dominating allocation would not + + + align:start position:0% +pareto-dominating allocation would not +be feasible in contradiction to what we + + align:start position:0% +be feasible in contradiction to what we + + + align:start position:0% +be feasible in contradiction to what we +assumed + + align:start position:0% +assumed + + + align:start position:0% +assumed +so that was qed that was the end of the + + align:start position:0% +so that was qed that was the end of the + + + align:start position:0% +so that was qed that was the end of the +proof of the first welfare theorem + + align:start position:0% +proof of the first welfare theorem + + + align:start position:0% +proof of the first welfare theorem +now later even today we'll review it you + + align:start position:0% +now later even today we'll review it you + + + align:start position:0% +now later even today we'll review it you +know this thing fails with + + align:start position:0% +know this thing fails with + + + align:start position:0% +know this thing fails with +if these sums are infinite sums and + + align:start position:0% +if these sums are infinite sums and + + + align:start position:0% +if these sums are infinite sums and +don't + + align:start position:0% +don't + + + align:start position:0% +don't +have finite value + + align:start position:0% +have finite value + + + align:start position:0% +have finite value +then the second welfare theorem was + + align:start position:0% +then the second welfare theorem was + + + align:start position:0% +then the second welfare theorem was +illustrated here + + align:start position:0% +illustrated here + + + align:start position:0% +illustrated here +that we have pareto optimum + + align:start position:0% +that we have pareto optimum + + + align:start position:0% +that we have pareto optimum +characterized by tangency of + + align:start position:0% +characterized by tangency of + + + align:start position:0% +characterized by tangency of +indifference curves + + align:start position:0% +indifference curves + + + align:start position:0% +indifference curves +but that nevertheless uh it's not + + align:start position:0% +but that nevertheless uh it's not + + + align:start position:0% +but that nevertheless uh it's not +reachable + + align:start position:0% +reachable + + + align:start position:0% +reachable +if we start from the endowment and start + + align:start position:0% +if we start from the endowment and start + + + align:start position:0% +if we start from the endowment and start +drawing potential budget lines + + align:start position:0% +drawing potential budget lines + + + align:start position:0% +drawing potential budget lines +through the endowment point as you would + + align:start position:0% +through the endowment point as you would + + + align:start position:0% +through the endowment point as you would +for candidate budget lines in a + + align:start position:0% +for candidate budget lines in a + + + align:start position:0% +for candidate budget lines in a +competitive equilibria so i mean this + + align:start position:0% +competitive equilibria so i mean this + + + align:start position:0% +competitive equilibria so i mean this +was meant to illustrate that + + align:start position:0% +was meant to illustrate that + + + align:start position:0% +was meant to illustrate that +to get to this particular pareto optimum + + align:start position:0% +to get to this particular pareto optimum + + + align:start position:0% +to get to this particular pareto optimum +as in the second welfare theorem + + align:start position:0% +as in the second welfare theorem + + + align:start position:0% +as in the second welfare theorem +we're going to have to take some value + + align:start position:0% +we're going to have to take some value + + + align:start position:0% +we're going to have to take some value +away from agent a over here + + align:start position:0% +away from agent a over here + + + align:start position:0% +away from agent a over here +and give it to agent b + + align:start position:0% +and give it to agent b + + + align:start position:0% +and give it to agent b +and and that's what this said the tax on + + align:start position:0% +and and that's what this said the tax on + + + align:start position:0% +and and that's what this said the tax on +a + + align:start position:0% +a + + + align:start position:0% +a +is equal to the subsidy on b + + align:start position:0% +is equal to the subsidy on b + + + align:start position:0% +is equal to the subsidy on b +t being transfer so negative is a tax + + align:start position:0% +t being transfer so negative is a tax + + + align:start position:0% +t being transfer so negative is a tax +so then we could get as in the second + + align:start position:0% +so then we could get as in the second + + + align:start position:0% +so then we could get as in the second +welfare theorem to any allocation + + align:start position:0% +welfare theorem to any allocation + + + align:start position:0% +welfare theorem to any allocation +along + + align:start position:0% +along + + + align:start position:0% +along +that contract curve where the inference + + align:start position:0% +that contract curve where the inference + + + align:start position:0% +that contract curve where the inference +curves are tangent by reallocating + + align:start position:0% +curves are tangent by reallocating + + + align:start position:0% +curves are tangent by reallocating +wealth now to prove it we went through + + align:start position:0% +wealth now to prove it we went through + + + align:start position:0% +wealth now to prove it we went through +this constructive argument we defined an + + align:start position:0% +this constructive argument we defined an + + + align:start position:0% +this constructive argument we defined an +economy and this slide or a version of + + align:start position:0% +economy and this slide or a version of + + + align:start position:0% +economy and this slide or a version of +it shows up at least three times + + align:start position:0% +it shows up at least three times + + + align:start position:0% +it shows up at least three times +in these six lectures so an economy + + align:start position:0% +in these six lectures so an economy + + + align:start position:0% +in these six lectures so an economy +consisting of preferences endowments + + align:start position:0% +consisting of preferences endowments + + + align:start position:0% +consisting of preferences endowments +production sets and profit shares + + align:start position:0% +production sets and profit shares + + + align:start position:0% +production sets and profit shares +here assuming a lot more concavity and + + align:start position:0% +here assuming a lot more concavity and + + + align:start position:0% +here assuming a lot more concavity and +convexity and preferences production + + align:start position:0% +convexity and preferences production + + + align:start position:0% +convexity and preferences production +sets etc and then we get the second + + align:start position:0% +sets etc and then we get the second + + + align:start position:0% +sets etc and then we get the second +welfare theorem that any pareto optimum + + align:start position:0% +welfare theorem that any pareto optimum + + + align:start position:0% +welfare theorem that any pareto optimum +can be supported for some wealth any + + align:start position:0% +can be supported for some wealth any + + + align:start position:0% +can be supported for some wealth any +pareto optimum associated with some + + align:start position:0% +pareto optimum associated with some + + + align:start position:0% +pareto optimum associated with some +lambda vector of maximized weighted + + align:start position:0% +lambda vector of maximized weighted + + + align:start position:0% +lambda vector of maximized weighted +utilities can be supported by a suitable + + align:start position:0% +utilities can be supported by a suitable + + + align:start position:0% +utilities can be supported by a suitable +redistribution of wealth the way we + + align:start position:0% +redistribution of wealth the way we + + + align:start position:0% +redistribution of wealth the way we +prove this was to go back to what you + + align:start position:0% +prove this was to go back to what you + + + align:start position:0% +prove this was to go back to what you +know about + + align:start position:0% +know about + + + align:start position:0% +know about +lagrangians so this was i think also in + + align:start position:0% +lagrangians so this was i think also in + + + align:start position:0% +lagrangians so this was i think also in +the second lecture of the class + + align:start position:0% +the second lecture of the class + + + align:start position:0% +the second lecture of the class +and you've used it over and over again + + align:start position:0% +and you've used it over and over again + + + align:start position:0% +and you've used it over and over again +maximizing concave functions on convex + + align:start position:0% +maximizing concave functions on convex + + + align:start position:0% +maximizing concave functions on convex +sets you know generating all these + + align:start position:0% +sets you know generating all these + + + align:start position:0% +sets you know generating all these +shadow prices + + align:start position:0% +shadow prices + + + align:start position:0% +shadow prices +so we used it here three times first we + + align:start position:0% +so we used it here three times first we + + + align:start position:0% +so we used it here three times first we +use it for the pareto problem so + + align:start position:0% +use it for the pareto problem so + + + align:start position:0% +use it for the pareto problem so +we're starting with a pareto optimal + + align:start position:0% +we're starting with a pareto optimal + + + align:start position:0% +we're starting with a pareto optimal +allocation so we know again from things + + align:start position:0% +allocation so we know again from things + + + align:start position:0% +allocation so we know again from things +you did earlier in the class + + align:start position:0% +you did earlier in the class + + + align:start position:0% +you did earlier in the class +when we introduced the notion of pareto + + align:start position:0% +when we introduced the notion of pareto + + + align:start position:0% +when we introduced the notion of pareto +optimality i don't remember the lecture + + align:start position:0% +optimality i don't remember the lecture + + + align:start position:0% +optimality i don't remember the lecture +number + + align:start position:0% +number + + + align:start position:0% +number +we maximize weighted sums of utilities + + align:start position:0% +we maximize weighted sums of utilities + + + align:start position:0% +we maximize weighted sums of utilities +lambdas being these weights subject to + + align:start position:0% +lambdas being these weights subject to + + + align:start position:0% +lambdas being these weights subject to +resource constraints and production + + align:start position:0% +resource constraints and production + + + align:start position:0% +resource constraints and production +constraints that's all written down here + + align:start position:0% +constraints that's all written down here + + + align:start position:0% +constraints that's all written down here +the solution to any one of these pareto + + align:start position:0% +the solution to any one of these pareto + + + align:start position:0% +the solution to any one of these pareto +problems is pareto optimal and all the + + align:start position:0% +problems is pareto optimal and all the + + + align:start position:0% +problems is pareto optimal and all the +optima can be described as solutions for + + align:start position:0% +optima can be described as solutions for + + + align:start position:0% +optima can be described as solutions for +some lambdas so we go start thinking + + align:start position:0% +some lambdas so we go start thinking + + + align:start position:0% +some lambdas so we go start thinking +about these so-called pareto problems as + + align:start position:0% +about these so-called pareto problems as + + + align:start position:0% +about these so-called pareto problems as +equivalent with pareto optimal + + align:start position:0% +equivalent with pareto optimal + + + align:start position:0% +equivalent with pareto optimal +allocations use the lagrangian set it up + + align:start position:0% +allocations use the lagrangian set it up + + + align:start position:0% +allocations use the lagrangian set it up +this way + + align:start position:0% +this way + + + align:start position:0% +this way +and get the first order conditions + + align:start position:0% +and get the first order conditions + + + align:start position:0% +and get the first order conditions +including the primal + + align:start position:0% +including the primal + + + align:start position:0% +including the primal +dual feasibility on the shadow prices + + align:start position:0% +dual feasibility on the shadow prices + + + align:start position:0% +dual feasibility on the shadow prices +complementary slackness and all of that + + align:start position:0% +complementary slackness and all of that + + + align:start position:0% +complementary slackness and all of that +the point is that with all that + + align:start position:0% +the point is that with all that + + + align:start position:0% +the point is that with all that +concavity and convexity as appropriate + + align:start position:0% +concavity and convexity as appropriate + + + align:start position:0% +concavity and convexity as appropriate +these first order conditions from + + align:start position:0% +these first order conditions from + + + align:start position:0% +these first order conditions from +differentiating the lagrangian are not + + align:start position:0% +differentiating the lagrangian are not + + + align:start position:0% +differentiating the lagrangian are not +only necessary they're sufficient so any + + align:start position:0% +only necessary they're sufficient so any + + + align:start position:0% +only necessary they're sufficient so any +solution + + align:start position:0% +solution + + + align:start position:0% +solution +to these first order conditions + + align:start position:0% +to these first order conditions + + + align:start position:0% +to these first order conditions +allocations and shadow prices that + + align:start position:0% +allocations and shadow prices that + + + align:start position:0% +allocations and shadow prices that +satisfy the first order conditions + + align:start position:0% +satisfy the first order conditions + + + align:start position:0% +satisfy the first order conditions +will be + + align:start position:0% +will be + + + align:start position:0% +will be +pareto optimal will be a solution to the + + align:start position:0% +pareto optimal will be a solution to the + + + align:start position:0% +pareto optimal will be a solution to the +pareto problem + + align:start position:0% +pareto problem + + + align:start position:0% +pareto problem +so we did that + + align:start position:0% +so we did that + + + align:start position:0% +so we did that +then we went to the second part reminded + + align:start position:0% +then we went to the second part reminded + + + align:start position:0% +then we went to the second part reminded +ourselves of the definition of a + + align:start position:0% +ourselves of the definition of a + + + align:start position:0% +ourselves of the definition of a +competitive equilibrium with transfers + + align:start position:0% +competitive equilibrium with transfers + + + align:start position:0% +competitive equilibrium with transfers +namely consumer optimization firm + + align:start position:0% +namely consumer optimization firm + + + align:start position:0% +namely consumer optimization firm +maximization of profits and so on along + + align:start position:0% +maximization of profits and so on along + + + align:start position:0% +maximization of profits and so on along +with a feasible distribution of wealth + + align:start position:0% +with a feasible distribution of wealth + + + align:start position:0% +with a feasible distribution of wealth +as i was just saying so here's the + + align:start position:0% +as i was just saying so here's the + + + align:start position:0% +as i was just saying so here's the +second and third time we're going to use + + align:start position:0% +second and third time we're going to use + + + align:start position:0% +second and third time we're going to use +the lagrangian for the consumer + + align:start position:0% +the lagrangian for the consumer + + + align:start position:0% +the lagrangian for the consumer +optimization problem and use it for the + + align:start position:0% +optimization problem and use it for the + + + align:start position:0% +optimization problem and use it for the +firm profit maximization here's the + + align:start position:0% +firm profit maximization here's the + + + align:start position:0% +firm profit maximization here's the +consumer maximization problem maximizing + + align:start position:0% +consumer maximization problem maximizing + + + align:start position:0% +consumer maximization problem maximizing +utilities subject to a budget we get + + align:start position:0% +utilities subject to a budget we get + + + align:start position:0% +utilities subject to a budget we get +this first order condition and again + + align:start position:0% +this first order condition and again + + + align:start position:0% +this first order condition and again +with the concavity in the constraint + + align:start position:0% +with the concavity in the constraint + + + align:start position:0% +with the concavity in the constraint +setting in the objective function and + + align:start position:0% +setting in the objective function and + + + align:start position:0% +setting in the objective function and +convexity in the constraint set these + + align:start position:0% +convexity in the constraint set these + + + align:start position:0% +convexity in the constraint set these +are not only necessary but they're + + align:start position:0% +are not only necessary but they're + + + align:start position:0% +are not only necessary but they're +sufficient condition for an optimum all + + align:start position:0% +sufficient condition for an optimum all + + + align:start position:0% +sufficient condition for an optimum all +we need to do is find the mu i at given + + align:start position:0% +we need to do is find the mu i at given + + + align:start position:0% +we need to do is find the mu i at given +prices p and an x i star and it will be + + align:start position:0% +prices p and an x i star and it will be + + + align:start position:0% +prices p and an x i star and it will be +maximizing for the consumer + + align:start position:0% +maximizing for the consumer + + + align:start position:0% +maximizing for the consumer +each consumer + + align:start position:0% +each consumer + + + align:start position:0% +each consumer +likewise for the + + align:start position:0% +likewise for the + + + align:start position:0% +likewise for the +firm maximization we have + + align:start position:0% +firm maximization we have + + + align:start position:0% +firm maximization we have +unnecessary and sufficient conditions in + + align:start position:0% +unnecessary and sufficient conditions in + + + align:start position:0% +unnecessary and sufficient conditions in +the to find candidates for the + + align:start position:0% +the to find candidates for the + + + align:start position:0% +the to find candidates for the +decentralized competitive equilibria + + align:start position:0% +decentralized competitive equilibria + + + align:start position:0% +decentralized competitive equilibria +and then all we did was match them up + + align:start position:0% +and then all we did was match them up + + + align:start position:0% +and then all we did was match them up +now i think the tricky thing here is to + + align:start position:0% +now i think the tricky thing here is to + + + align:start position:0% +now i think the tricky thing here is to +remember what the given is and what the + + align:start position:0% +remember what the given is and what the + + + align:start position:0% +remember what the given is and what the +objective function the given was a + + align:start position:0% +objective function the given was a + + + align:start position:0% +objective function the given was a +pareto optimal allocation so for the + + align:start position:0% +pareto optimal allocation so for the + + + align:start position:0% +pareto optimal allocation so for the +consumer we started out with these + + align:start position:0% +consumer we started out with these + + + align:start position:0% +consumer we started out with these +conditions which are the necessary and + + align:start position:0% +conditions which are the necessary and + + + align:start position:0% +conditions which are the necessary and +sufficient conditions from the pareto + + align:start position:0% +sufficient conditions from the pareto + + + align:start position:0% +sufficient conditions from the pareto +problem being satisfied so we have the + + align:start position:0% +problem being satisfied so we have the + + + align:start position:0% +problem being satisfied so we have the +gamma + + align:start position:0% +gamma + + + align:start position:0% +gamma +sub l for commodity l as a given the + + align:start position:0% +sub l for commodity l as a given the + + + align:start position:0% +sub l for commodity l as a given the +lambdas were given because we had a + + align:start position:0% +lambdas were given because we had a + + + align:start position:0% +lambdas were given because we had a +given certain candidate pareto optimum + + align:start position:0% +given certain candidate pareto optimum + + + align:start position:0% +given certain candidate pareto optimum +these are all satisfied we're looking + + align:start position:0% +these are all satisfied we're looking + + + align:start position:0% +these are all satisfied we're looking +for this thing we're trying to see if + + align:start position:0% +for this thing we're trying to see if + + + align:start position:0% +for this thing we're trying to see if +consumers are going to be maximizing so + + align:start position:0% +consumers are going to be maximizing so + + + align:start position:0% +consumers are going to be maximizing so +the candidate for the price would be the + + align:start position:0% +the candidate for the price would be the + + + align:start position:0% +the candidate for the price would be the +lagrange multiplier and the candidate + + align:start position:0% +lagrange multiplier and the candidate + + + align:start position:0% +lagrange multiplier and the candidate +for the + + align:start position:0% +for the + + + align:start position:0% +for the +marginality of income the shadow price + + align:start position:0% +marginality of income the shadow price + + + align:start position:0% +marginality of income the shadow price +and the budget constraint would be one + + align:start position:0% +and the budget constraint would be one + + + align:start position:0% +and the budget constraint would be one +over lambda okay so here i go back to + + align:start position:0% +over lambda okay so here i go back to + + + align:start position:0% +over lambda okay so here i go back to +the slides of the rocky mountain in + + align:start position:0% +the slides of the rocky mountain in + + + align:start position:0% +the slides of the rocky mountain in +kansas this establishes a direct + + align:start position:0% +kansas this establishes a direct + + + align:start position:0% +kansas this establishes a direct +relationship between the pareto weights + + align:start position:0% +relationship between the pareto weights + + + align:start position:0% +relationship between the pareto weights +and the pareto problem and the marginal + + align:start position:0% +and the pareto problem and the marginal + + + align:start position:0% +and the pareto problem and the marginal +utility of wealth and hence the level of + + align:start position:0% +utility of wealth and hence the level of + + + align:start position:0% +utility of wealth and hence the level of +wealth it's quite general it's super + + align:start position:0% +wealth it's quite general it's super + + + align:start position:0% +wealth it's quite general it's super +robust + + align:start position:0% +robust + + + align:start position:0% +robust +and so then the rest of this was just + + align:start position:0% +and so then the rest of this was just + + + align:start position:0% +and so then the rest of this was just +you know the tedious part of + + align:start position:0% +you know the tedious part of + + + align:start position:0% +you know the tedious part of +constructing the wealth as the valuation + + align:start position:0% +constructing the wealth as the valuation + + + align:start position:0% +constructing the wealth as the valuation +of expenditure and making sure that they + + align:start position:0% +of expenditure and making sure that they + + + align:start position:0% +of expenditure and making sure that they +all add up we refer to this way of + + align:start position:0% +all add up we refer to this way of + + + align:start position:0% +all add up we refer to this way of +finding the prices from the second + + align:start position:0% +finding the prices from the second + + + align:start position:0% +finding the prices from the second +welfare theorem as margin of utility + + align:start position:0% +welfare theorem as margin of utility + + + align:start position:0% +welfare theorem as margin of utility +pricing + + align:start position:0% +pricing + + + align:start position:0% +pricing +i mean more accurately + + align:start position:0% +i mean more accurately + + + align:start position:0% +i mean more accurately +it's the lambda weighted margin + + align:start position:0% +it's the lambda weighted margin + + + align:start position:0% +it's the lambda weighted margin +utilities which are equated all over the + + align:start position:0% +utilities which are equated all over the + + + align:start position:0% +utilities which are equated all over the +households not the levels + + align:start position:0% +households not the levels + + + align:start position:0% +households not the levels +but when you take ratios across + + align:start position:0% +but when you take ratios across + + + align:start position:0% +but when you take ratios across +different goods l and k the marginal + + align:start position:0% +different goods l and k the marginal + + + align:start position:0% +different goods l and k the marginal +rates of substa the lambdas cancel out + + align:start position:0% +rates of substa the lambdas cancel out + + + align:start position:0% +rates of substa the lambdas cancel out +so the marginal rates of substitution + + align:start position:0% +so the marginal rates of substitution + + + align:start position:0% +so the marginal rates of substitution +are equated over all the households as + + align:start position:0% +are equated over all the households as + + + align:start position:0% +are equated over all the households as +they are in this picture + + align:start position:0% +they are in this picture + + + align:start position:0% +they are in this picture +along this orange green orange green + + align:start position:0% +along this orange green orange green + + + align:start position:0% +along this orange green orange green +yellow orange line + + align:start position:0% +yellow orange line + + + align:start position:0% +yellow orange line +yeah and this made the wealth add up + + align:start position:0% +yeah and this made the wealth add up + + + align:start position:0% +yeah and this made the wealth add up +now we did a second proof of the welfare + + align:start position:0% +now we did a second proof of the welfare + + + align:start position:0% +now we did a second proof of the welfare +theorem + + align:start position:0% +theorem + + + align:start position:0% +theorem +which is namely + + align:start position:0% +which is namely + + + align:start position:0% +which is namely +one nuance thing which is instead of + + align:start position:0% +one nuance thing which is instead of + + + align:start position:0% +one nuance thing which is instead of +just maximizing utility subject to + + align:start position:0% +just maximizing utility subject to + + + align:start position:0% +just maximizing utility subject to +budget we minimize expenditures subject + + align:start position:0% +budget we minimize expenditures subject + + + align:start position:0% +budget we minimize expenditures subject +to achieving a certain level of utility + + align:start position:0% +to achieving a certain level of utility + + + align:start position:0% +to achieving a certain level of utility +that kind of conjured up + + align:start position:0% +that kind of conjured up + + + align:start position:0% +that kind of conjured up +you know this + + align:start position:0% +you know this + + + align:start position:0% +you know this +so this is + + align:start position:0% +so this is + + + align:start position:0% +so this is +sort of the in + + align:start position:0% +sort of the in + + + align:start position:0% +sort of the in +the target and different curve + + align:start position:0% +the target and different curve + + + align:start position:0% +the target and different curve +as it were + + align:start position:0% +as it were + + + align:start position:0% +as it were +as if it were coming from one consumer + + align:start position:0% +as if it were coming from one consumer + + + align:start position:0% +as if it were coming from one consumer +interesting comment + + align:start position:0% +interesting comment + + + align:start position:0% +interesting comment +but it's just the aggregated + + align:start position:0% +but it's just the aggregated + + + align:start position:0% +but it's just the aggregated +better than set + + align:start position:0% +better than set + + + align:start position:0% +better than set +associated with + + align:start position:0% +associated with + + + align:start position:0% +associated with +the pareto optimal allocation + + align:start position:0% +the pareto optimal allocation + + + align:start position:0% +the pareto optimal allocation +the other part of this diagram is two + + align:start position:0% +the other part of this diagram is two + + + align:start position:0% +the other part of this diagram is two +production functions + + align:start position:0% +production functions + + + align:start position:0% +production functions +different from each other but aggregated + + align:start position:0% +different from each other but aggregated + + + align:start position:0% +different from each other but aggregated +up to an aggregated production function + + align:start position:0% +up to an aggregated production function + + + align:start position:0% +up to an aggregated production function +and then you can see as if it were a + + align:start position:0% +and then you can see as if it were a + + + align:start position:0% +and then you can see as if it were a +robinson crusoe representative consumer + + align:start position:0% +robinson crusoe representative consumer + + + align:start position:0% +robinson crusoe representative consumer +you know the optimum is characterized by + + align:start position:0% +you know the optimum is characterized by + + + align:start position:0% +you know the optimum is characterized by +a maximal utility level subject to the + + align:start position:0% +a maximal utility level subject to the + + + align:start position:0% +a maximal utility level subject to the +single production set and then + + align:start position:0% +single production set and then + + + align:start position:0% +single production set and then +my point is that we get this + + align:start position:0% +my point is that we get this + + + align:start position:0% +my point is that we get this +separating hyperplane + + align:start position:0% +separating hyperplane + + + align:start position:0% +separating hyperplane +so + + align:start position:0% +so + + + align:start position:0% +so +all these definitions supporting + + align:start position:0% +all these definitions supporting + + + align:start position:0% +all these definitions supporting +hyperplane etc + + align:start position:0% +hyperplane etc + + + align:start position:0% +hyperplane etc +that's really where + + align:start position:0% +that's really where + + + align:start position:0% +that's really where +given all the convexity that's all you + + align:start position:0% +given all the convexity that's all you + + + align:start position:0% +given all the convexity that's all you +need to do these convex sets are + + align:start position:0% +need to do these convex sets are + + + align:start position:0% +need to do these convex sets are +separated from each other so this is a + + align:start position:0% +separated from each other so this is a + + + align:start position:0% +separated from each other so this is a +quite general proof and it works in many + + align:start position:0% +quite general proof and it works in many + + + align:start position:0% +quite general proof and it works in many +spaces not just finite dimensional + + align:start position:0% +spaces not just finite dimensional + + + align:start position:0% +spaces not just finite dimensional +euclidean spaces + + align:start position:0% +euclidean spaces + + + align:start position:0% +euclidean spaces +and you know we're about to review + + align:start position:0% +and you know we're about to review + + + align:start position:0% +and you know we're about to review +the representative consumer as i said + + align:start position:0% +the representative consumer as i said + + + align:start position:0% +the representative consumer as i said +this looks all the world like + + align:start position:0% +this looks all the world like + + + align:start position:0% +this looks all the world like +like a representative consumer because + + align:start position:0% +like a representative consumer because + + + align:start position:0% +like a representative consumer because +i've seemingly added up the indifference + + align:start position:0% +i've seemingly added up the indifference + + + align:start position:0% +i've seemingly added up the indifference +curves + + align:start position:0% +curves + + + align:start position:0% +curves +but one should be aware that it is not + + align:start position:0% +but one should be aware that it is not + + + align:start position:0% +but one should be aware that it is not +the gorman consumer that's going on here + + align:start position:0% +the gorman consumer that's going on here + + + align:start position:0% +the gorman consumer that's going on here +and this particular pareto optimum + + align:start position:0% +and this particular pareto optimum + + + align:start position:0% +and this particular pareto optimum +you know is is sensitive to the + + align:start position:0% +you know is is sensitive to the + + + align:start position:0% +you know is is sensitive to the +distribution of wealth you just can't + + align:start position:0% +distribution of wealth you just can't + + + align:start position:0% +distribution of wealth you just can't +see that i did not go through that when + + align:start position:0% +see that i did not go through that when + + + align:start position:0% +see that i did not go through that when +i lectured gave this lecture because we + + align:start position:0% +i lectured gave this lecture because we + + + align:start position:0% +i lectured gave this lecture because we +hadn't gotten to gorman and it wouldn't + + align:start position:0% +hadn't gotten to gorman and it wouldn't + + + align:start position:0% +hadn't gotten to gorman and it wouldn't +have made any sense + + align:start position:0% +have made any sense + + + align:start position:0% +have made any sense +but though i might as well say it now + + align:start position:0% +but though i might as well say it now + + + align:start position:0% +but though i might as well say it now +if you don't have a gorman + + align:start position:0% +if you don't have a gorman + + + align:start position:0% +if you don't have a gorman +representative consumer then you know as + + align:start position:0% +representative consumer then you know as + + + align:start position:0% +representative consumer then you know as +you + + align:start position:0% +you + + + align:start position:0% +you +increase this guy's budget line and + + align:start position:0% +increase this guy's budget line and + + + align:start position:0% +increase this guy's budget line and +decreases this one + + align:start position:0% +decreases this one + + + align:start position:0% +decreases this one +you may you may change the the shape of + + align:start position:0% +you may you may change the the shape of + + + align:start position:0% +you may you may change the the shape of +this seemingly aggregated up + + align:start position:0% +this seemingly aggregated up + + + align:start position:0% +this seemingly aggregated up +indifference curve and therefore change + + align:start position:0% +indifference curve and therefore change + + + align:start position:0% +indifference curve and therefore change +the whole optimal allocation so + + align:start position:0% +the whole optimal allocation so + + + align:start position:0% +the whole optimal allocation so +hopefully that helps you kind of think + + align:start position:0% +hopefully that helps you kind of think + + + align:start position:0% +hopefully that helps you kind of think +about the hidden way in which + + align:start position:0% +about the hidden way in which + + + align:start position:0% +about the hidden way in which +heterogeneity is entering into this + + align:start position:0% +heterogeneity is entering into this + + + align:start position:0% +heterogeneity is entering into this +picture + + align:start position:0% +picture + + + align:start position:0% +picture +and and this lecture i finished it off + + align:start position:0% +and and this lecture i finished it off + + + align:start position:0% +and and this lecture i finished it off +in an abstract way by saying + + align:start position:0% +in an abstract way by saying + + + align:start position:0% +in an abstract way by saying +the proofs of the welfare theorems are + + align:start position:0% +the proofs of the welfare theorems are + + + align:start position:0% +the proofs of the welfare theorems are +quite general that does not require + + align:start position:0% +quite general that does not require + + + align:start position:0% +quite general that does not require +finite dimensional + + align:start position:0% +finite dimensional + + + align:start position:0% +finite dimensional +commodity spaces + + align:start position:0% +commodity spaces + + + align:start position:0% +commodity spaces +i gave you the + + align:start position:0% +i gave you the + + + align:start position:0% +i gave you the +sufficient assumptions for the two + + align:start position:0% +sufficient assumptions for the two + + + align:start position:0% +sufficient assumptions for the two +welfare theorems + + align:start position:0% +welfare theorems + + + align:start position:0% +welfare theorems +and kind of quit there + + align:start position:0% +and kind of quit there + + + align:start position:0% +and kind of quit there +if we had more time i could have gone + + align:start position:0% +if we had more time i could have gone + + + align:start position:0% +if we had more time i could have gone +into greater detail + + align:start position:0% +into greater detail + + + align:start position:0% +into greater detail +i only asserted without proving it + + align:start position:0% +i only asserted without proving it + + + align:start position:0% +i only asserted without proving it +that if we took what we did earlier in + + align:start position:0% +that if we took what we did earlier in + + + align:start position:0% +that if we took what we did earlier in +the course about pareto optima with + + align:start position:0% +the course about pareto optima with + + + align:start position:0% +the course about pareto optima with +obstacles to trade + + align:start position:0% +obstacles to trade + + + align:start position:0% +obstacles to trade +with incentive constraints and + + align:start position:0% +with incentive constraints and + + + align:start position:0% +with incentive constraints and +potentially non-convex consumption sets + + align:start position:0% +potentially non-convex consumption sets + + + align:start position:0% +potentially non-convex consumption sets +because of discrete choices + + align:start position:0% +because of discrete choices + + + align:start position:0% +because of discrete choices +we could nevertheless introduce + + align:start position:0% +we could nevertheless introduce + + + align:start position:0% +we could nevertheless introduce +lotteries + + align:start position:0% +lotteries + + + align:start position:0% +lotteries +and that would have turned the space + + align:start position:0% +and that would have turned the space + + + align:start position:0% +and that would have turned the space +into a convex set and the theorems as in + + align:start position:0% +into a convex set and the theorems as in + + + align:start position:0% +into a convex set and the theorems as in +deru you know what it would apply to + + align:start position:0% +deru you know what it would apply to + + + align:start position:0% +deru you know what it would apply to +that so although this lecture just + + align:start position:0% +that so although this lecture just + + + align:start position:0% +that so although this lecture just +proves the welfare theorems carefully + + align:start position:0% +proves the welfare theorems carefully + + + align:start position:0% +proves the welfare theorems carefully +for finite dimensional commodity spaces + + align:start position:0% +for finite dimensional commodity spaces + + + align:start position:0% +for finite dimensional commodity spaces +and only asserted that the theorems + + align:start position:0% +and only asserted that the theorems + + + align:start position:0% +and only asserted that the theorems +extend + + align:start position:0% +extend + + + align:start position:0% +extend +it would cover + + align:start position:0% +it would cover + + + align:start position:0% +it would cover +competitive equilibria + + align:start position:0% +competitive equilibria + + + align:start position:0% +competitive equilibria +in contract space + + align:start position:0% +in contract space + + + align:start position:0% +in contract space +where households can buy whatever + + align:start position:0% +where households can buy whatever + + + align:start position:0% +where households can buy whatever +contracts they want + + align:start position:0% +contracts they want + + + align:start position:0% +contracts they want +granted at certain prices and firms as + + align:start position:0% +granted at certain prices and firms as + + + align:start position:0% +granted at certain prices and firms as +intermediaries will create contracts + + align:start position:0% +intermediaries will create contracts + + + align:start position:0% +intermediaries will create contracts +that maximize profits + + align:start position:0% +that maximize profits + + + align:start position:0% +that maximize profits +tying some of the loose ends together + + align:start position:0% +tying some of the loose ends together + + + align:start position:0% +tying some of the loose ends together +but without actually going through much + + align:start position:0% +but without actually going through much + + + align:start position:0% +but without actually going through much +of the details there so that was lecture + + align:start position:0% +of the details there so that was lecture + + + align:start position:0% +of the details there so that was lecture + + align:start position:0% + + + align:start position:0% +questions + + align:start position:0% +questions + + + align:start position:0% +questions +about 16. + + align:start position:0% + + + + align:start position:0% + +well we'll come back to it again because + + align:start position:0% +well we'll come back to it again because + + + align:start position:0% +well we'll come back to it again because +we're going to go through the failures + + align:start position:0% +we're going to go through the failures + + + align:start position:0% +we're going to go through the failures +or review them quickly then this was the + + align:start position:0% +or review them quickly then this was the + + + align:start position:0% +or review them quickly then this was the +existence lecture the point being that + + align:start position:0% +existence lecture the point being that + + + align:start position:0% +existence lecture the point being that +that for example the first welfare + + align:start position:0% +that for example the first welfare + + + align:start position:0% +that for example the first welfare +theorem assumes existence of an + + align:start position:0% +theorem assumes existence of an + + + align:start position:0% +theorem assumes existence of an +equilibrium and then assures everybody + + align:start position:0% +equilibrium and then assures everybody + + + align:start position:0% +equilibrium and then assures everybody +that it would be optimal under + + align:start position:0% +that it would be optimal under + + + align:start position:0% +that it would be optimal under +sufficient conditions but if the model + + align:start position:0% +sufficient conditions but if the model + + + align:start position:0% +sufficient conditions but if the model +could be vacuous if there is no + + align:start position:0% +could be vacuous if there is no + + + align:start position:0% +could be vacuous if there is no +competitive equilibrium so we're we're + + align:start position:0% +competitive equilibrium so we're we're + + + align:start position:0% +competitive equilibrium so we're we're +dealing with things like that directly + + align:start position:0% +dealing with things like that directly + + + align:start position:0% +dealing with things like that directly +in this lecture and this was a listing + + align:start position:0% +in this lecture and this was a listing + + + align:start position:0% +in this lecture and this was a listing +of the things covered so the main + + align:start position:0% +of the things covered so the main + + + align:start position:0% +of the things covered so the main +mathematical object tool really was a + + align:start position:0% +mathematical object tool really was a + + + align:start position:0% +mathematical object tool really was a +fixed point theorem + + align:start position:0% +fixed point theorem + + + align:start position:0% +fixed point theorem +this was an example that some function + + align:start position:0% +this was an example that some function + + + align:start position:0% +this was an example that some function +has across the 45 degree line in which + + align:start position:0% +has across the 45 degree line in which + + + align:start position:0% +has across the 45 degree line in which +case whatever you put in you get back + + align:start position:0% +case whatever you put in you get back + + + align:start position:0% +case whatever you put in you get back +out the argument in the range is the + + align:start position:0% +out the argument in the range is the + + + align:start position:0% +out the argument in the range is the +argument in the domain under the under + + align:start position:0% +argument in the domain under the under + + + align:start position:0% +argument in the domain under the under +the function f and it was sufficient for + + align:start position:0% +the function f and it was sufficient for + + + align:start position:0% +the function f and it was sufficient for +this to have the set of faces of values + + align:start position:0% +this to have the set of faces of values + + + align:start position:0% +this to have the set of faces of values +in the domain and the range being + + align:start position:0% +in the domain and the range being + + + align:start position:0% +in the domain and the range being +non-empty convex and compact and for the + + align:start position:0% +non-empty convex and compact and for the + + + align:start position:0% +non-empty convex and compact and for the +function f to be continuous and that's + + align:start position:0% +function f to be continuous and that's + + + align:start position:0% +function f to be continuous and that's +brower's fixed point theorem + + align:start position:0% +brower's fixed point theorem + + + align:start position:0% +brower's fixed point theorem +i should say though well we're about to + + align:start position:0% +i should say though well we're about to + + + align:start position:0% +i should say though well we're about to +get there that this is all about + + align:start position:0% +get there that this is all about + + + align:start position:0% +get there that this is all about +existence it it's not about how to find + + align:start position:0% +existence it it's not about how to find + + + align:start position:0% +existence it it's not about how to find +it and at least one of you has asked me + + align:start position:0% +it and at least one of you has asked me + + + align:start position:0% +it and at least one of you has asked me +questions about that + + align:start position:0% +questions about that + + + align:start position:0% +questions about that +anyway this is brower's fixed point + + align:start position:0% +anyway this is brower's fixed point + + + align:start position:0% +anyway this is brower's fixed point +theorem it's paired with kakutani's + + align:start position:0% +theorem it's paired with kakutani's + + + align:start position:0% +theorem it's paired with kakutani's +fixed point theorem and the way in which + + align:start position:0% +fixed point theorem and the way in which + + + align:start position:0% +fixed point theorem and the way in which +they differed primarily was not the set + + align:start position:0% +they differed primarily was not the set + + + align:start position:0% +they differed primarily was not the set +a which is still compact and convex and + + align:start position:0% +a which is still compact and convex and + + + align:start position:0% +a which is still compact and convex and +non-empty but the function f which is no + + align:start position:0% +non-empty but the function f which is no + + + align:start position:0% +non-empty but the function f which is no +longer single necessarily single valued + + align:start position:0% +longer single necessarily single valued + + + align:start position:0% +longer single necessarily single valued +it could be multiple values or there are + + align:start position:0% +it could be multiple values or there are + + + align:start position:0% +it could be multiple values or there are +multiple values in the range for for any + + align:start position:0% +multiple values in the range for for any + + + align:start position:0% +multiple values in the range for for any +particular input x in the domain and of + + align:start position:0% +particular input x in the domain and of + + + align:start position:0% +particular input x in the domain and of +course not anything goes and had to be + + align:start position:0% +course not anything goes and had to be + + + align:start position:0% +course not anything goes and had to be +convex value and continuous in a certain + + align:start position:0% +convex value and continuous in a certain + + + align:start position:0% +convex value and continuous in a certain +sense and then with kakutani again we + + align:start position:0% +sense and then with kakutani again we + + + align:start position:0% +sense and then with kakutani again we +have a fixed point + + align:start position:0% +have a fixed point + + + align:start position:0% +have a fixed point +so these are very powerful tools and + + align:start position:0% +so these are very powerful tools and + + + align:start position:0% +so these are very powerful tools and +they're used for competitive equilibria + + align:start position:0% +they're used for competitive equilibria + + + align:start position:0% +they're used for competitive equilibria +in one way or another and used in + + align:start position:0% +in one way or another and used in + + + align:start position:0% +in one way or another and used in +games + + align:start position:0% +games + + + align:start position:0% +games +and we + + align:start position:0% +and we + + + align:start position:0% +and we +actually + + align:start position:0% +actually + + + align:start position:0% +actually +combined those at the end of this + + align:start position:0% +combined those at the end of this + + + align:start position:0% +combined those at the end of this +lecture to have a game that would be + + align:start position:0% +lecture to have a game that would be + + + align:start position:0% +lecture to have a game that would be +achieved under a nash equilibrium as a + + align:start position:0% +achieved under a nash equilibrium as a + + + align:start position:0% +achieved under a nash equilibrium as a +volreisian equilibrium okay + + align:start position:0% +volreisian equilibrium okay + + + align:start position:0% +volreisian equilibrium okay +so here are + + align:start position:0% +so here are + + + align:start position:0% +so here are +what happens if you don't assume + + align:start position:0% +what happens if you don't assume + + + align:start position:0% +what happens if you don't assume +continuity of the function you get these + + align:start position:0% +continuity of the function you get these + + + align:start position:0% +continuity of the function you get these +jumps so if the aggregate demand for an + + align:start position:0% +jumps so if the aggregate demand for an + + + align:start position:0% +jumps so if the aggregate demand for an +economy somehow had jumps like this then + + align:start position:0% +economy somehow had jumps like this then + + + align:start position:0% +economy somehow had jumps like this then +you could not be assured that there + + align:start position:0% +you could not be assured that there + + + align:start position:0% +you could not be assured that there +would exist a competitive equilibrium + + align:start position:0% +would exist a competitive equilibrium + + + align:start position:0% +would exist a competitive equilibrium +and we're we're looking for the + + align:start position:0% +and we're we're looking for the + + + align:start position:0% +and we're we're looking for the +existence + + align:start position:0% +existence + + + align:start position:0% +existence +of prices + + align:start position:0% +of prices + + + align:start position:0% +of prices +such that you put prices in to each of + + align:start position:0% +such that you put prices in to each of + + + align:start position:0% +such that you put prices in to each of +the agents + + align:start position:0% +the agents + + + align:start position:0% +the agents +maximization problems + + align:start position:0% +maximization problems + + + align:start position:0% +maximization problems +look at their demands + + align:start position:0% +look at their demands + + + align:start position:0% +look at their demands +see if demands add up to supply and if + + align:start position:0% +see if demands add up to supply and if + + + align:start position:0% +see if demands add up to supply and if +we find the price that makes that happen + + align:start position:0% +we find the price that makes that happen + + + align:start position:0% +we find the price that makes that happen +and this all of this can be formulated + + align:start position:0% +and this all of this can be formulated + + + align:start position:0% +and this all of this can be formulated +as a fixed point now i did not go + + align:start position:0% +as a fixed point now i did not go + + + align:start position:0% +as a fixed point now i did not go +through + + align:start position:0% +through + + + align:start position:0% +through +the math of this because it's + + align:start position:0% +the math of this because it's + + + align:start position:0% +the math of this because it's +surprisingly tedious + + align:start position:0% +surprisingly tedious + + + align:start position:0% +surprisingly tedious +however let me say that the existence + + align:start position:0% +however let me say that the existence + + + align:start position:0% +however let me say that the existence +proof is the existence of a competitive + + align:start position:0% +proof is the existence of a competitive + + + align:start position:0% +proof is the existence of a competitive +equilibrium as in at least one fixed + + align:start position:0% +equilibrium as in at least one fixed + + + align:start position:0% +equilibrium as in at least one fixed +point + + align:start position:0% +point + + + align:start position:0% +point +herbert scarf did a lot of work on this + + align:start position:0% +herbert scarf did a lot of work on this + + + align:start position:0% +herbert scarf did a lot of work on this +subject and in his proof of the + + align:start position:0% +subject and in his proof of the + + + align:start position:0% +subject and in his proof of the +volrasian equilibrium he actually did + + align:start position:0% +volrasian equilibrium he actually did + + + align:start position:0% +volrasian equilibrium he actually did +more + + align:start position:0% +more + + + align:start position:0% +more +which was to go back to brower and + + align:start position:0% +which was to go back to brower and + + + align:start position:0% +which was to go back to brower and +actually show how to find the fixed + + align:start position:0% +actually show how to find the fixed + + + align:start position:0% +actually show how to find the fixed +point that is to say in an algorithm + + align:start position:0% +point that is to say in an algorithm + + + align:start position:0% +point that is to say in an algorithm +take a guess + + align:start position:0% +take a guess + + + align:start position:0% +take a guess +look at directional derivatives + + align:start position:0% +look at directional derivatives + + + align:start position:0% +look at directional derivatives +formulate a new guess + + align:start position:0% +formulate a new guess + + + align:start position:0% +formulate a new guess +and iterate until you get to + + align:start position:0% +and iterate until you get to + + + align:start position:0% +and iterate until you get to +the end or approximately the end however + + align:start position:0% +the end or approximately the end however + + + align:start position:0% +the end or approximately the end however +close the computer can make it and he + + align:start position:0% +close the computer can make it and he + + + align:start position:0% +close the computer can make it and he +would have constructively found the + + align:start position:0% +would have constructively found the + + + align:start position:0% +would have constructively found the +brower's fixed point which works much + + align:start position:0% +brower's fixed point which works much + + + align:start position:0% +brower's fixed point which works much +more generally than just finding the + + align:start position:0% +more generally than just finding the + + + align:start position:0% +more generally than just finding the +existence of a competitive equilibrium + + align:start position:0% +existence of a competitive equilibrium + + + align:start position:0% +existence of a competitive equilibrium +this comes up later when we talked about + + align:start position:0% +this comes up later when we talked about + + + align:start position:0% +this comes up later when we talked about +restrictions on data having to do with + + align:start position:0% +restrictions on data having to do with + + + align:start position:0% +restrictions on data having to do with +algorithms and what the algorithms + + align:start position:0% +algorithms and what the algorithms + + + align:start position:0% +algorithms and what the algorithms +actually look like when computing + + align:start position:0% +actually look like when computing + + + align:start position:0% +actually look like when computing +solutions to individual problems and + + align:start position:0% +solutions to individual problems and + + + align:start position:0% +solutions to individual problems and +defining a competitive equilibria anyway + + align:start position:0% +defining a competitive equilibria anyway + + + align:start position:0% +defining a competitive equilibria anyway +i just wanted to draw your attention to + + align:start position:0% +i just wanted to draw your attention to + + + align:start position:0% +i just wanted to draw your attention to +the distinction as an overview that's my + + align:start position:0% +the distinction as an overview that's my + + + align:start position:0% +the distinction as an overview that's my +job today between existence of a + + align:start position:0% +job today between existence of a + + + align:start position:0% +job today between existence of a +competitive equilibrium and how to find + + align:start position:0% +competitive equilibrium and how to find + + + align:start position:0% +competitive equilibrium and how to find +the competitive equilibrium + + align:start position:0% +the competitive equilibrium + + + align:start position:0% +the competitive equilibrium +algorithmically + + align:start position:0% +algorithmically + + + align:start position:0% +algorithmically +okay + + align:start position:0% +okay + + + align:start position:0% +okay +what we did do in this lecture + + align:start position:0% +what we did do in this lecture + + + align:start position:0% +what we did do in this lecture +was to prove the existence of a + + align:start position:0% +was to prove the existence of a + + + align:start position:0% +was to prove the existence of a +competitive equilibrium using the second + + align:start position:0% +competitive equilibrium using the second + + + align:start position:0% +competitive equilibrium using the second +welfare theorem which we just reviewed + + align:start position:0% +welfare theorem which we just reviewed + + + align:start position:0% +welfare theorem which we just reviewed +in lecture 16. so the idea is instead of + + align:start position:0% +in lecture 16. so the idea is instead of + + + align:start position:0% +in lecture 16. so the idea is instead of +iterating on candidate prices + + align:start position:0% +iterating on candidate prices + + + align:start position:0% +iterating on candidate prices +to find where supply is equal to demand + + align:start position:0% +to find where supply is equal to demand + + + align:start position:0% +to find where supply is equal to demand +we iterate on these lambda weights + + align:start position:0% +we iterate on these lambda weights + + + align:start position:0% +we iterate on these lambda weights +and uh and the idea is very much here's + + align:start position:0% +and uh and the idea is very much here's + + + align:start position:0% +and uh and the idea is very much here's +that economy again i promised you it + + align:start position:0% +that economy again i promised you it + + + align:start position:0% +that economy again i promised you it +would keep coming back the statement of + + align:start position:0% +would keep coming back the statement of + + + align:start position:0% +would keep coming back the statement of +the economy with the convexity and + + align:start position:0% +the economy with the convexity and + + + align:start position:0% +the economy with the convexity and +concavity + + align:start position:0% +concavity + + + align:start position:0% +concavity +the idea is to + + align:start position:0% +the idea is to + + + align:start position:0% +the idea is to +go back to the pareto problem this is + + align:start position:0% +go back to the pareto problem this is + + + align:start position:0% +go back to the pareto problem this is +now the second time today that this is + + align:start position:0% +now the second time today that this is + + + align:start position:0% +now the second time today that this is +the pareto problem has come up we just + + align:start position:0% +the pareto problem has come up we just + + + align:start position:0% +the pareto problem has come up we just +used it in 16 for the second welfare + + align:start position:0% +used it in 16 for the second welfare + + + align:start position:0% +used it in 16 for the second welfare +theorem here it is again stated rather + + align:start position:0% +theorem here it is again stated rather + + + align:start position:0% +theorem here it is again stated rather +succinctly to remind us of these lambda + + align:start position:0% +succinctly to remind us of these lambda + + + align:start position:0% +succinctly to remind us of these lambda +i weights such that when we max we get + + align:start position:0% +i weights such that when we max we get + + + align:start position:0% +i weights such that when we max we get +pareto optima so we start with those + + align:start position:0% +pareto optima so we start with those + + + align:start position:0% +pareto optima so we start with those +lambdas + + align:start position:0% +lambdas + + + align:start position:0% +lambdas +and then we + + align:start position:0% +and then we + + + align:start position:0% +and then we +essentially + + align:start position:0% +essentially + + + align:start position:0% +essentially +look at the + + align:start position:0% +look at the + + + align:start position:0% +look at the +solution to the pareto problem these x + + align:start position:0% +solution to the pareto problem these x + + + align:start position:0% +solution to the pareto problem these x +hats + + align:start position:0% +hats + + + align:start position:0% +hats +for those particular lambdas look at the + + align:start position:0% +for those particular lambdas look at the + + + align:start position:0% +for those particular lambdas look at the +prices which you now know and remember + + align:start position:0% +prices which you now know and remember + + + align:start position:0% +prices which you now know and remember +are the shadow prices on the resource + + align:start position:0% +are the shadow prices on the resource + + + align:start position:0% +are the shadow prices on the resource +constraints and we generate the wealth + + align:start position:0% +constraints and we generate the wealth + + + align:start position:0% +constraints and we generate the wealth +associating with this purchasing power + + align:start position:0% +associating with this purchasing power + + + align:start position:0% +associating with this purchasing power +so what we're going to look for to get a + + align:start position:0% +so what we're going to look for to get a + + + align:start position:0% +so what we're going to look for to get a +standard volraisian equilibrium + + align:start position:0% +standard volraisian equilibrium + + + align:start position:0% +standard volraisian equilibrium +is particular lambdas such that + + align:start position:0% +is particular lambdas such that + + + align:start position:0% +is particular lambdas such that +the valuation + + align:start position:0% +the valuation + + + align:start position:0% +the valuation +of privately owned resources for a given + + align:start position:0% +of privately owned resources for a given + + + align:start position:0% +of privately owned resources for a given +household eye is equal to + + align:start position:0% +household eye is equal to + + + align:start position:0% +household eye is equal to +the wealth coming from the lambdas + + align:start position:0% +the wealth coming from the lambdas + + + align:start position:0% +the wealth coming from the lambdas +here this is a better statement of it a + + align:start position:0% +here this is a better statement of it a + + + align:start position:0% +here this is a better statement of it a +particular lambda star the fixed point + + align:start position:0% +particular lambda star the fixed point + + + align:start position:0% +particular lambda star the fixed point +find me please the fixed point would be + + align:start position:0% +find me please the fixed point would be + + + align:start position:0% +find me please the fixed point would be +such that + + align:start position:0% +such that + + + align:start position:0% +such that +when we substitute lambda in the pareto + + align:start position:0% +when we substitute lambda in the pareto + + + align:start position:0% +when we substitute lambda in the pareto +problem and generate the optimal + + align:start position:0% +problem and generate the optimal + + + align:start position:0% +problem and generate the optimal +allocations we'll have some valuation at + + align:start position:0% +allocations we'll have some valuation at + + + align:start position:0% +allocations we'll have some valuation at +those shadow prices + + align:start position:0% +those shadow prices + + + align:start position:0% +those shadow prices +of the expenditures which when we sum up + + align:start position:0% +of the expenditures which when we sum up + + + align:start position:0% +of the expenditures which when we sum up +over + + align:start position:0% +over + + + align:start position:0% +over +and summed up over all the commodities l + + align:start position:0% +and summed up over all the commodities l + + + align:start position:0% +and summed up over all the commodities l +would be exactly equal to the right-hand + + align:start position:0% +would be exactly equal to the right-hand + + + align:start position:0% +would be exactly equal to the right-hand +side of the budget the valuation of + + align:start position:0% +side of the budget the valuation of + + + align:start position:0% +side of the budget the valuation of +purchasing power that the consumer has + + align:start position:0% +purchasing power that the consumer has + + + align:start position:0% +purchasing power that the consumer has +as a result of owning the endowment and + + align:start position:0% +as a result of owning the endowment and + + + align:start position:0% +as a result of owning the endowment and +getting shares in the profits of the + + align:start position:0% +getting shares in the profits of the + + + align:start position:0% +getting shares in the profits of the +firms when the firms are maximizing at + + align:start position:0% +firms when the firms are maximizing at + + + align:start position:0% +firms when the firms are maximizing at +that same lambda star so this is the + + align:start position:0% +that same lambda star so this is the + + + align:start position:0% +that same lambda star so this is the +fixed point + + align:start position:0% +fixed point + + + align:start position:0% +fixed point +i think i mentioned in a sort of + + align:start position:0% +i think i mentioned in a sort of + + + align:start position:0% +i think i mentioned in a sort of +question and answer at the beginning of + + align:start position:0% +question and answer at the beginning of + + + align:start position:0% +question and answer at the beginning of +lecture 18 when we reviewed 17 that i + + align:start position:0% +lecture 18 when we reviewed 17 that i + + + align:start position:0% +lecture 18 when we reviewed 17 that i +felt i hadn't done a good enough job + + align:start position:0% +felt i hadn't done a good enough job + + + align:start position:0% +felt i hadn't done a good enough job +explaining the intuition for this + + align:start position:0% +explaining the intuition for this + + + align:start position:0% +explaining the intuition for this +mapping but it does come from the second + + align:start position:0% +mapping but it does come from the second + + + align:start position:0% +mapping but it does come from the second +welfare theorem start with a given guess + + align:start position:0% +welfare theorem start with a given guess + + + align:start position:0% +welfare theorem start with a given guess +about the lambda that pins down + + align:start position:0% +about the lambda that pins down + + + align:start position:0% +about the lambda that pins down +which particular pareto optimum we're + + align:start position:0% +which particular pareto optimum we're + + + align:start position:0% +which particular pareto optimum we're +targeting and suppose it were the case + + align:start position:0% +targeting and suppose it were the case + + + align:start position:0% +targeting and suppose it were the case +that the valuation of expenditure at + + align:start position:0% +that the valuation of expenditure at + + + align:start position:0% +that the valuation of expenditure at +that optimum for consumer i were + + align:start position:0% +that optimum for consumer i were + + + align:start position:0% +that optimum for consumer i were +strictly greater than the valuation of + + align:start position:0% +strictly greater than the valuation of + + + align:start position:0% +strictly greater than the valuation of +his or her + + align:start position:0% +his or her + + + align:start position:0% +his or her +privately owned resources + + align:start position:0% +privately owned resources + + + align:start position:0% +privately owned resources +well in this case we gave this consumer + + align:start position:0% +well in this case we gave this consumer + + + align:start position:0% +well in this case we gave this consumer +too much they can't afford it so the + + align:start position:0% +too much they can't afford it so the + + + align:start position:0% +too much they can't afford it so the +obvious way to iterate + + align:start position:0% +obvious way to iterate + + + align:start position:0% +obvious way to iterate +if indeed you were even searching + + align:start position:0% +if indeed you were even searching + + + align:start position:0% +if indeed you were even searching +is to reduce the lambda for this + + align:start position:0% +is to reduce the lambda for this + + + align:start position:0% +is to reduce the lambda for this +household and increase the lambdas for + + align:start position:0% +household and increase the lambdas for + + + align:start position:0% +household and increase the lambdas for +the other so this is very much like that + + align:start position:0% +the other so this is very much like that + + + align:start position:0% +the other so this is very much like that +edgeworth box diagram for the second + + align:start position:0% +edgeworth box diagram for the second + + + align:start position:0% +edgeworth box diagram for the second +welfare theorem where i said you know + + align:start position:0% +welfare theorem where i said you know + + + align:start position:0% +welfare theorem where i said you know +household a + + align:start position:0% +household a + + + align:start position:0% +household a +has to give up stuff this would be + + align:start position:0% +has to give up stuff this would be + + + align:start position:0% +has to give up stuff this would be +household a if the inequality is greater + + align:start position:0% +household a if the inequality is greater + + + align:start position:0% +household a if the inequality is greater +than or equal to and household b would + + align:start position:0% +than or equal to and household b would + + + align:start position:0% +than or equal to and household b would +be the recipient and be getting the + + align:start position:0% +be the recipient and be getting the + + + align:start position:0% +be the recipient and be getting the +transfers for household b you'd be under + + align:start position:0% +transfers for household b you'd be under + + + align:start position:0% +transfers for household b you'd be under +valuing evaluation of the resources that + + align:start position:0% +valuing evaluation of the resources that + + + align:start position:0% +valuing evaluation of the resources that +the assigned optimum could be less than + + align:start position:0% +the assigned optimum could be less than + + + align:start position:0% +the assigned optimum could be less than +the evaluation of their privately owned + + align:start position:0% +the evaluation of their privately owned + + + align:start position:0% +the evaluation of their privately owned +resources + + align:start position:0% +resources + + + align:start position:0% +resources +now again negishi didn't actually show + + align:start position:0% +now again negishi didn't actually show + + + align:start position:0% +now again negishi didn't actually show +that one could find the fixed point by + + align:start position:0% +that one could find the fixed point by + + + align:start position:0% +that one could find the fixed point by +iterating on the lambdas but but in + + align:start position:0% +iterating on the lambdas but but in + + + align:start position:0% +iterating on the lambdas but but in +practice + + align:start position:0% +practice + + + align:start position:0% +practice +it typically works so as a numerical + + align:start position:0% +it typically works so as a numerical + + + align:start position:0% +it typically works so as a numerical +algorithm you could just be trying out + + align:start position:0% +algorithm you could just be trying out + + + align:start position:0% +algorithm you could just be trying out +candidates lambda checking out these + + align:start position:0% +candidates lambda checking out these + + + align:start position:0% +candidates lambda checking out these +kinds of budget equations and and so on + + align:start position:0% +kinds of budget equations and and so on + + + align:start position:0% +kinds of budget equations and and so on +so here again this links up to lambda + + align:start position:0% +so here again this links up to lambda + + + align:start position:0% +so here again this links up to lambda +equal marginal utility of income that's + + align:start position:0% +equal marginal utility of income that's + + + align:start position:0% +equal marginal utility of income that's +the kansas rocky mountain pictures at + + align:start position:0% +the kansas rocky mountain pictures at + + + align:start position:0% +the kansas rocky mountain pictures at +the beginning and i reinforced that when + + align:start position:0% +the beginning and i reinforced that when + + + align:start position:0% +the beginning and i reinforced that when +we went through the second welfare + + align:start position:0% +we went through the second welfare + + + align:start position:0% +we went through the second welfare +theorem so this proof of the existence + + align:start position:0% +theorem so this proof of the existence + + + align:start position:0% +theorem so this proof of the existence +is working off the same sort of + + align:start position:0% +is working off the same sort of + + + align:start position:0% +is working off the same sort of +equivalence between the lambdas and the + + align:start position:0% +equivalence between the lambdas and the + + + align:start position:0% +equivalence between the lambdas and the +inverse marginal utility of wealth this + + align:start position:0% +inverse marginal utility of wealth this + + + align:start position:0% +inverse marginal utility of wealth this +is the + + align:start position:0% +is the + + + align:start position:0% +is the +computer science part + + align:start position:0% +computer science part + + + align:start position:0% +computer science part +that it looks like it might be + + align:start position:0% +that it looks like it might be + + + align:start position:0% +that it looks like it might be +hard to find actually constructively so + + align:start position:0% +hard to find actually constructively so + + + align:start position:0% +hard to find actually constructively so +these guys algorithmically want to find + + align:start position:0% +these guys algorithmically want to find + + + align:start position:0% +these guys algorithmically want to find +the valerian equilibrium not just + + align:start position:0% +the valerian equilibrium not just + + + align:start position:0% +the valerian equilibrium not just +be happy with + + align:start position:0% +be happy with + + + align:start position:0% +be happy with +the notion that there's a fixed point so + + align:start position:0% +the notion that there's a fixed point so + + + align:start position:0% +the notion that there's a fixed point so +that it exists and this literature works + + align:start position:0% +that it exists and this literature works + + + align:start position:0% +that it exists and this literature works +on the same they kind of discovered + + align:start position:0% +on the same they kind of discovered + + + align:start position:0% +on the same they kind of discovered +again negishi so that's why i told you + + align:start position:0% +again negishi so that's why i told you + + + align:start position:0% +again negishi so that's why i told you +about it and you but you get a better + + align:start position:0% +about it and you but you get a better + + + align:start position:0% +about it and you but you get a better +sense here and i gave you a hint of that + + align:start position:0% +sense here and i gave you a hint of that + + + align:start position:0% +sense here and i gave you a hint of that +with respect to herb scarf that the way + + align:start position:0% +with respect to herb scarf that the way + + + align:start position:0% +with respect to herb scarf that the way +to find it is to sort of periodically + + align:start position:0% +to find it is to sort of periodically + + + align:start position:0% +to find it is to sort of periodically +look at the aggregate demand arctic or + + align:start position:0% +look at the aggregate demand arctic or + + + align:start position:0% +look at the aggregate demand arctic or +oracle as it were and take a local + + align:start position:0% +oracle as it were and take a local + + + align:start position:0% +oracle as it were and take a local +derivative of it to see kind of which + + align:start position:0% +derivative of it to see kind of which + + + align:start position:0% +derivative of it to see kind of which +way you ought to move + + align:start position:0% +way you ought to move + + + align:start position:0% +way you ought to move +so it's a little bit harder than what i + + align:start position:0% +so it's a little bit harder than what i + + + align:start position:0% +so it's a little bit harder than what i +said about just iterating on nigishi's + + align:start position:0% +said about just iterating on nigishi's + + + align:start position:0% +said about just iterating on nigishi's +algorithm + + align:start position:0% +algorithm + + + align:start position:0% +algorithm +but their point is that they designed an + + align:start position:0% +but their point is that they designed an + + + align:start position:0% +but their point is that they designed an +algorithm that finds the competitive + + align:start position:0% +algorithm that finds the competitive + + + align:start position:0% +algorithm that finds the competitive +equilibrium using negishi and it's not + + align:start position:0% +equilibrium using negishi and it's not + + + align:start position:0% +equilibrium using negishi and it's not +that hard in the sense that it's + + align:start position:0% +that hard in the sense that it's + + + align:start position:0% +that hard in the sense that it's +polynomial of degree 3 and the number of + + align:start position:0% +polynomial of degree 3 and the number of + + + align:start position:0% +polynomial of degree 3 and the number of +goods which is n + + align:start position:0% +goods which is n + + + align:start position:0% +goods which is n +so it's a polynomial rather than + + align:start position:0% +so it's a polynomial rather than + + + align:start position:0% +so it's a polynomial rather than +exponentially hard + + align:start position:0% +exponentially hard + + + align:start position:0% +exponentially hard +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so then we went to the second part of + + align:start position:0% +so then we went to the second part of + + + align:start position:0% +so then we went to the second part of +the lecture which was strategic form + + align:start position:0% +the lecture which was strategic form + + + align:start position:0% +the lecture which was strategic form +games this looks quite different you + + align:start position:0% +games this looks quite different you + + + align:start position:0% +games this looks quite different you +have utility functions again but they + + align:start position:0% +have utility functions again but they + + + align:start position:0% +have utility functions again but they +can be a function of other people's + + align:start position:0% +can be a function of other people's + + + align:start position:0% +can be a function of other people's +strategies not just your own + + align:start position:0% +strategies not just your own + + + align:start position:0% +strategies not just your own +finite set of players that's kind of + + align:start position:0% +finite set of players that's kind of + + + align:start position:0% +finite set of players that's kind of +similar + + align:start position:0% +similar + + + align:start position:0% +similar +and we talked about strategy profiles + + align:start position:0% +and we talked about strategy profiles + + + align:start position:0% +and we talked about strategy profiles +what household eye is doing or trader i + + align:start position:0% +what household eye is doing or trader i + + + align:start position:0% +what household eye is doing or trader i +versus what all the others are doing + + align:start position:0% +versus what all the others are doing + + + align:start position:0% +versus what all the others are doing +and we defined mixed strategies + + align:start position:0% +and we defined mixed strategies + + + align:start position:0% +and we defined mixed strategies +where the players are randomizing + + align:start position:0% +where the players are randomizing + + + align:start position:0% +where the players are randomizing +potentially + + align:start position:0% +potentially + + + align:start position:0% +potentially +over + + align:start position:0% +over + + + align:start position:0% +over +a finite set of discrete actions + + align:start position:0% +a finite set of discrete actions + + + align:start position:0% +a finite set of discrete actions +so this is one place in the class in the + + align:start position:0% +so this is one place in the class in the + + + align:start position:0% +so this is one place in the class in the +course where again these lotteries come + + align:start position:0% +course where again these lotteries come + + + align:start position:0% +course where again these lotteries come +up to convexify things in this case and + + align:start position:0% +up to convexify things in this case and + + + align:start position:0% +up to convexify things in this case and +indeed the convexification + + align:start position:0% +indeed the convexification + + + align:start position:0% +indeed the convexification +is what allows + + align:start position:0% +is what allows + + + align:start position:0% +is what allows +us to prove the existence of this mixed + + align:start position:0% +us to prove the existence of this mixed + + + align:start position:0% +us to prove the existence of this mixed +strategy equilibrium + + align:start position:0% +strategy equilibrium + + + align:start position:0% +strategy equilibrium +a mixed strategy equilibrium is a set of + + align:start position:0% +a mixed strategy equilibrium is a set of + + + align:start position:0% +a mixed strategy equilibrium is a set of +randomization routines for each player + + align:start position:0% +randomization routines for each player + + + align:start position:0% +randomization routines for each player +stacked up in a vector + + align:start position:0% +stacked up in a vector + + + align:start position:0% +stacked up in a vector +such that given what all the other + + align:start position:0% +such that given what all the other + + + align:start position:0% +such that given what all the other +players i are doing minus i all the + + align:start position:0% +players i are doing minus i all the + + + align:start position:0% +players i are doing minus i all the +others but player i wants to do is the i + + align:start position:0% +others but player i wants to do is the i + + + align:start position:0% +others but player i wants to do is the i +star sigma star vector component of that + + align:start position:0% +star sigma star vector component of that + + + align:start position:0% +star sigma star vector component of that +vector better than any other component + + align:start position:0% +vector better than any other component + + + align:start position:0% +vector better than any other component +so this is the definition of a mixed + + align:start position:0% +so this is the definition of a mixed + + + align:start position:0% +so this is the definition of a mixed +strategy equilibrium + + align:start position:0% +strategy equilibrium + + + align:start position:0% +strategy equilibrium +and then we kind of have this + + align:start position:0% +and then we kind of have this + + + align:start position:0% +and then we kind of have this +interesting side note here + + align:start position:0% +interesting side note here + + + align:start position:0% +interesting side note here +and this is a third mean a third related + + align:start position:0% +and this is a third mean a third related + + + align:start position:0% +and this is a third mean a third related +but not identical statement which is you + + align:start position:0% +but not identical statement which is you + + + align:start position:0% +but not identical statement which is you +have a candidate for an equilibrium + + align:start position:0% +have a candidate for an equilibrium + + + align:start position:0% +have a candidate for an equilibrium +how do you know it really is an + + align:start position:0% +how do you know it really is an + + + align:start position:0% +how do you know it really is an +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +this is well it's related to the idea of + + align:start position:0% +this is well it's related to the idea of + + + align:start position:0% +this is well it's related to the idea of +the fixed point momentarily i'll show + + align:start position:0% +the fixed point momentarily i'll show + + + align:start position:0% +the fixed point momentarily i'll show +you that but + + align:start position:0% +you that but + + + align:start position:0% +you that but +but here the question is + + align:start position:0% +but here the question is + + + align:start position:0% +but here the question is +how many things do you have to check at + + align:start position:0% +how many things do you have to check at + + + align:start position:0% +how many things do you have to check at +the candidate mixed equilibrium nash + + align:start position:0% +the candidate mixed equilibrium nash + + + align:start position:0% +the candidate mixed equilibrium nash +mixed strategy nash equilibrium and + + align:start position:0% +mixed strategy nash equilibrium and + + + align:start position:0% +mixed strategy nash equilibrium and +it turns out you only need to to check + + align:start position:0% +it turns out you only need to to check + + + align:start position:0% +it turns out you only need to to check +pure strategy deviations here + + align:start position:0% +pure strategy deviations here + + + align:start position:0% +pure strategy deviations here +and rather than + + align:start position:0% +and rather than + + + align:start position:0% +and rather than +all possible mixed strategies + + align:start position:0% +all possible mixed strategies + + + align:start position:0% +all possible mixed strategies +thank goodness because that would be + + align:start position:0% +thank goodness because that would be + + + align:start position:0% +thank goodness because that would be +hard and the reason for that is if you + + align:start position:0% +hard and the reason for that is if you + + + align:start position:0% +hard and the reason for that is if you +can find + + align:start position:0% +can find + + + align:start position:0% +can find +a + + align:start position:0% +a + + + align:start position:0% +a +degenerate action which dominates the + + align:start position:0% +degenerate action which dominates the + + + align:start position:0% +degenerate action which dominates the +supposed mixed strategy maximum that's + + align:start position:0% +supposed mixed strategy maximum that's + + + align:start position:0% +supposed mixed strategy maximum that's +enough that's a particular degenerate + + align:start position:0% +enough that's a particular degenerate + + + align:start position:0% +enough that's a particular degenerate +mixed strategy to show that you could do + + align:start position:0% +mixed strategy to show that you could do + + + align:start position:0% +mixed strategy to show that you could do +better and if there were + + align:start position:0% +better and if there were + + + align:start position:0% +better and if there were +multiple ones that were doing better you + + align:start position:0% +multiple ones that were doing better you + + + align:start position:0% +multiple ones that were doing better you +pick the best one that dominates to + + align:start position:0% +pick the best one that dominates to + + + align:start position:0% +pick the best one that dominates to +break up the solution and if there were + + align:start position:0% +break up the solution and if there were + + + align:start position:0% +break up the solution and if there were +two or more we + + align:start position:0% +two or more we + + + align:start position:0% +two or more we +that generated the same utility you + + align:start position:0% +that generated the same utility you + + + align:start position:0% +that generated the same utility you +could randomize over them but there's no + + align:start position:0% +could randomize over them but there's no + + + align:start position:0% +could randomize over them but there's no +need because they all generate the same + + align:start position:0% +need because they all generate the same + + + align:start position:0% +need because they all generate the same +utility so you might as well pick one so + + align:start position:0% +utility so you might as well pick one so + + + align:start position:0% +utility so you might as well pick one so +that's the intuition + + align:start position:0% +that's the intuition + + + align:start position:0% +that's the intuition +for why it's enough to look to check a + + align:start position:0% +for why it's enough to look to check a + + + align:start position:0% +for why it's enough to look to check a +given candidate profile against these + + align:start position:0% +given candidate profile against these + + + align:start position:0% +given candidate profile against these +degenerate + + align:start position:0% +degenerate + + + align:start position:0% +degenerate +actions + + align:start position:0% +actions + + + align:start position:0% +actions +not mixed strategies + + align:start position:0% +not mixed strategies + + + align:start position:0% +not mixed strategies +okay the the rest of it is + + align:start position:0% +okay the the rest of it is + + + align:start position:0% +okay the the rest of it is +you know remembering + + align:start position:0% +you know remembering + + + align:start position:0% +you know remembering +these exactly these kinds of responses + + align:start position:0% +these exactly these kinds of responses + + + align:start position:0% +these exactly these kinds of responses +these sort of + + align:start position:0% +these sort of + + + align:start position:0% +these sort of +better than sen sets or you know uh + + align:start position:0% +better than sen sets or you know uh + + + align:start position:0% +better than sen sets or you know uh +best response sets + + align:start position:0% +best response sets + + + align:start position:0% +best response sets +for each player so + + align:start position:0% +for each player so + + + align:start position:0% +for each player so +given the others are doing you want a + + align:start position:0% +given the others are doing you want a + + + align:start position:0% +given the others are doing you want a +best response for player i obviously is + + align:start position:0% +best response for player i obviously is + + + align:start position:0% +best response for player i obviously is +going to maximize hopefully generating + + align:start position:0% +going to maximize hopefully generating + + + align:start position:0% +going to maximize hopefully generating +the same mixed strategy as a candidate + + align:start position:0% +the same mixed strategy as a candidate + + + align:start position:0% +the same mixed strategy as a candidate +but maybe not if it's not a + + align:start position:0% +but maybe not if it's not a + + + align:start position:0% +but maybe not if it's not a +mixed strategy equilibrium + + align:start position:0% +mixed strategy equilibrium + + + align:start position:0% +mixed strategy equilibrium +but all the other guys are doing the + + align:start position:0% +but all the other guys are doing the + + + align:start position:0% +but all the other guys are doing the +same so we're going to look for a fixed + + align:start position:0% +same so we're going to look for a fixed + + + align:start position:0% +same so we're going to look for a fixed +point in the space of best response + + align:start position:0% +point in the space of best response + + + align:start position:0% +point in the space of best response +strategies + + align:start position:0% +strategies + + + align:start position:0% +strategies +and the proof of the existence of the + + align:start position:0% +and the proof of the existence of the + + + align:start position:0% +and the proof of the existence of the +mixed strategy nash equilibrium had to + + align:start position:0% +mixed strategy nash equilibrium had to + + + align:start position:0% +mixed strategy nash equilibrium had to +do with the convexity of these best + + align:start position:0% +do with the convexity of these best + + + align:start position:0% +do with the convexity of these best +responses + + align:start position:0% +responses + + + align:start position:0% +responses +as in kakutani for example + + align:start position:0% +as in kakutani for example + + + align:start position:0% +as in kakutani for example +in particular all this stuff okay i'm a + + align:start position:0% +in particular all this stuff okay i'm a + + + align:start position:0% +in particular all this stuff okay i'm a +little worried i'm going to get bogged + + align:start position:0% +little worried i'm going to get bogged + + + align:start position:0% +little worried i'm going to get bogged +down in the weeds but i did want you to + + align:start position:0% +down in the weeds but i did want you to + + + align:start position:0% +down in the weeds but i did want you to +on the other hand + + align:start position:0% +on the other hand + + + align:start position:0% +on the other hand +kind of see the big picture + + align:start position:0% +kind of see the big picture + + + align:start position:0% +kind of see the big picture +so so now we have + + align:start position:0% +so so now we have + + + align:start position:0% +so so now we have +two parts the nash equilibrium for + + align:start position:0% +two parts the nash equilibrium for + + + align:start position:0% +two parts the nash equilibrium for +strategic games and the valrazian + + align:start position:0% +strategic games and the valrazian + + + align:start position:0% +strategic games and the valrazian +equilibria they + + align:start position:0% +equilibria they + + + align:start position:0% +equilibria they +they're all using fixed points + + align:start position:0% +they're all using fixed points + + + align:start position:0% +they're all using fixed points +but the economic problem looks kind of + + align:start position:0% +but the economic problem looks kind of + + + align:start position:0% +but the economic problem looks kind of +different + + align:start position:0% +different + + + align:start position:0% +different +so i finished this lecture off by + + align:start position:0% +so i finished this lecture off by + + + align:start position:0% +so i finished this lecture off by +drawing the connection + + align:start position:0% +drawing the connection + + + align:start position:0% +drawing the connection +like how do you actually set up a market + + align:start position:0% +like how do you actually set up a market + + + align:start position:0% +like how do you actually set up a market +to find a valrayan equilibria + + align:start position:0% +to find a valrayan equilibria + + + align:start position:0% +to find a valrayan equilibria +and + + align:start position:0% +and + + + align:start position:0% +and +we did that with respect to these limit + + align:start position:0% +we did that with respect to these limit + + + align:start position:0% +we did that with respect to these limit +order strategies on the supply and + + align:start position:0% +order strategies on the supply and + + + align:start position:0% +order strategies on the supply and +demand side + + align:start position:0% +demand side + + + align:start position:0% +demand side +and then wrote it down as a game so once + + align:start position:0% +and then wrote it down as a game so once + + + align:start position:0% +and then wrote it down as a game so once +we wrote this down as a game where + + align:start position:0% +we wrote this down as a game where + + + align:start position:0% +we wrote this down as a game where +players decide + + align:start position:0% +players decide + + + align:start position:0% +players decide +what to bid given what others are + + align:start position:0% +what to bid given what others are + + + align:start position:0% +what to bid given what others are +bidding + + align:start position:0% +bidding + + + align:start position:0% +bidding +it is a strategic form game and we + + align:start position:0% +it is a strategic form game and we + + + align:start position:0% +it is a strategic form game and we +characterize the equilibrium turned out + + align:start position:0% +characterize the equilibrium turned out + + + align:start position:0% +characterize the equilibrium turned out +you needed some penalties + + align:start position:0% +you needed some penalties + + + align:start position:0% +you needed some penalties +otherwise + + align:start position:0% +otherwise + + + align:start position:0% +otherwise +they would spend more than they have and + + align:start position:0% +they would spend more than they have and + + + align:start position:0% +they would spend more than they have and +that can't be consistent with + + align:start position:0% +that can't be consistent with + + + align:start position:0% +that can't be consistent with +maximization well it would be + + align:start position:0% +maximization well it would be + + + align:start position:0% +maximization well it would be +maximization but there'd be no limit + + align:start position:0% +maximization but there'd be no limit + + + align:start position:0% +maximization but there'd be no limit +so it would not be consistent with + + align:start position:0% +so it would not be consistent with + + + align:start position:0% +so it would not be consistent with +finding the vol resin equilibria + + align:start position:0% +finding the vol resin equilibria + + + align:start position:0% +finding the vol resin equilibria +so we did have to sort of find the + + align:start position:0% +so we did have to sort of find the + + + align:start position:0% +so we did have to sort of find the +optimal penalty structure in order to + + align:start position:0% +optimal penalty structure in order to + + + align:start position:0% +optimal penalty structure in order to +prove the theorem that any volran + + align:start position:0% +prove the theorem that any volran + + + align:start position:0% +prove the theorem that any volran +equilibrium could be supported as a + + align:start position:0% +equilibrium could be supported as a + + + align:start position:0% +equilibrium could be supported as a +mixed strategy equilibrium in this + + align:start position:0% +mixed strategy equilibrium in this + + + align:start position:0% +mixed strategy equilibrium in this +market gain and the other + + align:start position:0% +market gain and the other + + + align:start position:0% +market gain and the other +direction is also true so that + + align:start position:0% +direction is also true so that + + + align:start position:0% +direction is also true so that +was lecture 17 are there any questions + + align:start position:0% +was lecture 17 are there any questions + + + align:start position:0% +was lecture 17 are there any questions +about what we are doing in lecture 17. + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +18 was aggregation + + align:start position:0% +18 was aggregation + + + align:start position:0% +18 was aggregation +and again this is getting more recent so + + align:start position:0% +and again this is getting more recent so + + + align:start position:0% +and again this is getting more recent so +hopefully + + align:start position:0% +hopefully + + + align:start position:0% +hopefully +a little more fresh in your minds + + align:start position:0% +a little more fresh in your minds + + + align:start position:0% +a little more fresh in your minds +we want to do this positive and + + align:start position:0% +we want to do this positive and + + + align:start position:0% +we want to do this positive and +normative + + align:start position:0% +normative + + + align:start position:0% +normative +and i would say the content of this + + align:start position:0% +and i would say the content of this + + + align:start position:0% +and i would say the content of this +lecture is what do we have to assume + + align:start position:0% +lecture is what do we have to assume + + + align:start position:0% +lecture is what do we have to assume +like it or not in order to be in the + + align:start position:0% +like it or not in order to be in the + + + align:start position:0% +like it or not in order to be in the +land of macro where you have a + + align:start position:0% +land of macro where you have a + + + align:start position:0% +land of macro where you have a +representative consumer + + align:start position:0% +representative consumer + + + align:start position:0% +representative consumer +and is usable in the sense that what the + + align:start position:0% +and is usable in the sense that what the + + + align:start position:0% +and is usable in the sense that what the +representative consumer would do which + + align:start position:0% +representative consumer would do which + + + align:start position:0% +representative consumer would do which +from a positive economic standpoint + + align:start position:0% +from a positive economic standpoint + + + align:start position:0% +from a positive economic standpoint +generate aggregate demand as if you had + + align:start position:0% +generate aggregate demand as if you had + + + align:start position:0% +generate aggregate demand as if you had +all the underlying households but you + + align:start position:0% +all the underlying households but you + + + align:start position:0% +all the underlying households but you +don't need to do it you just use the + + align:start position:0% +don't need to do it you just use the + + + align:start position:0% +don't need to do it you just use the +representative consumer so it's a very + + align:start position:0% +representative consumer so it's a very + + + align:start position:0% +representative consumer so it's a very +powerful tool but again for you to + + align:start position:0% +powerful tool but again for you to + + + align:start position:0% +powerful tool but again for you to +decide + + align:start position:0% +decide + + + align:start position:0% +decide +how strong or potentially unrealistic + + align:start position:0% +how strong or potentially unrealistic + + + align:start position:0% +how strong or potentially unrealistic +are the underlying assumption set that + + align:start position:0% +are the underlying assumption set that + + + align:start position:0% +are the underlying assumption set that +allows us to do this + + align:start position:0% +allows us to do this + + + align:start position:0% +allows us to do this +so we reviewed the notion of the + + align:start position:0% +so we reviewed the notion of the + + + align:start position:0% +so we reviewed the notion of the +indirect utility function which is the + + align:start position:0% +indirect utility function which is the + + + align:start position:0% +indirect utility function which is the +maximized utility after solving max + + align:start position:0% +maximized utility after solving max + + + align:start position:0% +maximized utility after solving max +utility subject to budget given the + + align:start position:0% +utility subject to budget given the + + + align:start position:0% +utility subject to budget given the +parameters the price and the wealth of a + + align:start position:0% +parameters the price and the wealth of a + + + align:start position:0% +parameters the price and the wealth of a +household and + + align:start position:0% +household and + + + align:start position:0% +household and +we + + align:start position:0% +we + + + align:start position:0% +we +quickly reviewed some properties of the + + align:start position:0% +quickly reviewed some properties of the + + + align:start position:0% +quickly reviewed some properties of the +indirect utility functions in particular + + align:start position:0% +indirect utility functions in particular + + + align:start position:0% +indirect utility functions in particular +roy's identity which miraculously says + + align:start position:0% +roy's identity which miraculously says + + + align:start position:0% +roy's identity which miraculously says +that if you start differentiating the + + align:start position:0% +that if you start differentiating the + + + align:start position:0% +that if you start differentiating the +indirect utility function with respect + + align:start position:0% +indirect utility function with respect + + + align:start position:0% +indirect utility function with respect +to prices and respect to wealth and + + align:start position:0% +to prices and respect to wealth and + + + align:start position:0% +to prices and respect to wealth and +start taking ratios you'll get the + + align:start position:0% +start taking ratios you'll get the + + + align:start position:0% +start taking ratios you'll get the +underlying demands + + align:start position:0% +underlying demands + + + align:start position:0% +underlying demands +and this was a tool and it's kind of + + align:start position:0% +and this was a tool and it's kind of + + + align:start position:0% +and this was a tool and it's kind of +heavily used again now for the third + + align:start position:0% +heavily used again now for the third + + + align:start position:0% +heavily used again now for the third +time it just came from the lagrangian + + align:start position:0% +time it just came from the lagrangian + + + align:start position:0% +time it just came from the lagrangian +problem for the individual household + + align:start position:0% +problem for the individual household + + + align:start position:0% +problem for the individual household +and + + align:start position:0% +and + + + align:start position:0% +and +roy's identity came from that + + align:start position:0% +roy's identity came from that + + + align:start position:0% +roy's identity came from that +and then we got to gorman which is a + + align:start position:0% +and then we got to gorman which is a + + + align:start position:0% +and then we got to gorman which is a +particular representation of these + + align:start position:0% +particular representation of these + + + align:start position:0% +particular representation of these +indirect utility functions as a function + + align:start position:0% +indirect utility functions as a function + + + align:start position:0% +indirect utility functions as a function +of prices and wealth namely this thing + + align:start position:0% +of prices and wealth namely this thing + + + align:start position:0% +of prices and wealth namely this thing +in six + + align:start position:0% +in six + + + align:start position:0% +in six +so it's separable it has kind of an + + align:start position:0% +so it's separable it has kind of an + + + align:start position:0% +so it's separable it has kind of an +intercept as a function of p + + align:start position:0% +intercept as a function of p + + + align:start position:0% +intercept as a function of p +slope term on wealth as a function of p + + align:start position:0% +slope term on wealth as a function of p + + + align:start position:0% +slope term on wealth as a function of p +i noted that the cobb douglas would + + align:start position:0% +i noted that the cobb douglas would + + + align:start position:0% +i noted that the cobb douglas would +satisfy this we actually did the math + + align:start position:0% +satisfy this we actually did the math + + + align:start position:0% +satisfy this we actually did the math +this math is never very hard to do as + + align:start position:0% +this math is never very hard to do as + + + align:start position:0% +this math is never very hard to do as +long as you remember that when you have + + align:start position:0% +long as you remember that when you have + + + align:start position:0% +long as you remember that when you have +these cobb douglas utility function + + align:start position:0% +these cobb douglas utility function + + + align:start position:0% +these cobb douglas utility function +these coefficients represent expenditure + + align:start position:0% +these coefficients represent expenditure + + + align:start position:0% +these coefficients represent expenditure +shares so p1 times x1 + + align:start position:0% +shares so p1 times x1 + + + align:start position:0% +shares so p1 times x1 +is alpha share of wealth w + + align:start position:0% +is alpha share of wealth w + + + align:start position:0% +is alpha share of wealth w +likewise p2 x2 is one minus alpha share + + align:start position:0% +likewise p2 x2 is one minus alpha share + + + align:start position:0% +likewise p2 x2 is one minus alpha share +of wealth w for the second good + + align:start position:0% +of wealth w for the second good + + + align:start position:0% +of wealth w for the second good +so you can plot them down right away and + + align:start position:0% +so you can plot them down right away and + + + align:start position:0% +so you can plot them down right away and +just substitute into the given utility + + align:start position:0% +just substitute into the given utility + + + align:start position:0% +just substitute into the given utility +function and you end up with this + + align:start position:0% +function and you end up with this + + + align:start position:0% +function and you end up with this +functional form i also noted that + + align:start position:0% +functional form i also noted that + + + align:start position:0% +functional form i also noted that +although + + align:start position:0% +although + + + align:start position:0% +although +this is special + + align:start position:0% +this is special + + + align:start position:0% +this is special +in that the intercepts are zero it also + + align:start position:0% +in that the intercepts are zero it also + + + align:start position:0% +in that the intercepts are zero it also +seemingly assumed that the coefficients + + align:start position:0% +seemingly assumed that the coefficients + + + align:start position:0% +seemingly assumed that the coefficients +b are + + align:start position:0% +b are + + + align:start position:0% +b are +the same but no this was a particular + + align:start position:0% +the same but no this was a particular + + + align:start position:0% +the same but no this was a particular +indirect utility function for a + + align:start position:0% +indirect utility function for a + + + align:start position:0% +indirect utility function for a +household a given household we have to + + align:start position:0% +household a given household we have to + + + align:start position:0% +household a given household we have to +start putting i in the utility function + + align:start position:0% +start putting i in the utility function + + + align:start position:0% +start putting i in the utility function +to to decide and if + + align:start position:0% +to to decide and if + + + align:start position:0% +to to decide and if +if these alphas were different across + + align:start position:0% +if these alphas were different across + + + align:start position:0% +if these alphas were different across +different households we would need an + + align:start position:0% +different households we would need an + + + align:start position:0% +different households we would need an +alpha i on them and then this thing the + + align:start position:0% +alpha i on them and then this thing the + + + align:start position:0% +alpha i on them and then this thing the +gorman form would be violated + + align:start position:0% +gorman form would be violated + + + align:start position:0% +gorman form would be violated +so the first part of the positive + + align:start position:0% +so the first part of the positive + + + align:start position:0% +so the first part of the positive +representative consumer was just saying + + align:start position:0% +representative consumer was just saying + + + align:start position:0% +representative consumer was just saying +a definition of aggregate demand namely + + align:start position:0% +a definition of aggregate demand namely + + + align:start position:0% +a definition of aggregate demand namely +it's the sum of the demands over all the + + align:start position:0% +it's the sum of the demands over all the + + + align:start position:0% +it's the sum of the demands over all the +individual households at price vector p + + align:start position:0% +individual households at price vector p + + + align:start position:0% +individual households at price vector p +in wealth wi + + align:start position:0% +in wealth wi + + + align:start position:0% +in wealth wi +and the gorman part + + align:start position:0% +and the gorman part + + + align:start position:0% +and the gorman part +is to find + + align:start position:0% +is to find + + + align:start position:0% +is to find +that that demand + + align:start position:0% +that that demand + + + align:start position:0% +that that demand +this guy here + + align:start position:0% +this guy here + + + align:start position:0% +this guy here +depends on the vector of wealth in a + + align:start position:0% +depends on the vector of wealth in a + + + align:start position:0% +depends on the vector of wealth in a +particular way namely it's just the sum + + align:start position:0% +particular way namely it's just the sum + + + align:start position:0% +particular way namely it's just the sum +of them + + align:start position:0% +of them + + + align:start position:0% +of them +or in other words it's enough + + align:start position:0% +or in other words it's enough + + + align:start position:0% +or in other words it's enough +we should be able to find + + align:start position:0% +we should be able to find + + + align:start position:0% +we should be able to find +a utility function + + align:start position:0% +a utility function + + + align:start position:0% +a utility function +and give this mythical representative + + align:start position:0% +and give this mythical representative + + + align:start position:0% +and give this mythical representative +household all the wealth in the economy + + align:start position:0% +household all the wealth in the economy + + + align:start position:0% +household all the wealth in the economy +and have that + + align:start position:0% +and have that + + + align:start position:0% +and have that +household maximize utility + + align:start position:0% +household maximize utility + + + align:start position:0% +household maximize utility +generating aggregate demand which would + + align:start position:0% +generating aggregate demand which would + + + align:start position:0% +generating aggregate demand which would +be the sum of the individual demands if + + align:start position:0% +be the sum of the individual demands if + + + align:start position:0% +be the sum of the individual demands if +we'd bothered to keep track of the micro + + align:start position:0% +we'd bothered to keep track of the micro + + + align:start position:0% +we'd bothered to keep track of the micro +economy and the individual wealth levels + + align:start position:0% +economy and the individual wealth levels + + + align:start position:0% +economy and the individual wealth levels +so + + align:start position:0% +so + + + align:start position:0% +so +this statement was necessary but + + align:start position:0% +this statement was necessary but + + + align:start position:0% +this statement was necessary but +but it's about to be sufficient + + align:start position:0% +but it's about to be sufficient + + + align:start position:0% +but it's about to be sufficient +if the individual households have this + + align:start position:0% +if the individual households have this + + + align:start position:0% +if the individual households have this +particular indirect utility function of + + align:start position:0% +particular indirect utility function of + + + align:start position:0% +particular indirect utility function of +the gorman forum + + align:start position:0% +the gorman forum + + + align:start position:0% +the gorman forum +with the i only on the a + + align:start position:0% +with the i only on the a + + + align:start position:0% +with the i only on the a +intercept piece + + align:start position:0% +intercept piece + + + align:start position:0% +intercept piece +although w depends on i but that's + + align:start position:0% +although w depends on i but that's + + + align:start position:0% +although w depends on i but that's +because it's individual households + + align:start position:0% +because it's individual households + + + align:start position:0% +because it's individual households +wealth + + align:start position:0% +wealth + + + align:start position:0% +wealth +then the utility function we're looking + + align:start position:0% +then the utility function we're looking + + + align:start position:0% +then the utility function we're looking +for is just going to be an aggregated + + align:start position:0% +for is just going to be an aggregated + + + align:start position:0% +for is just going to be an aggregated +version + + align:start position:0% +version + + + align:start position:0% +version +sort of aggregating up the intercept + + align:start position:0% +sort of aggregating up the intercept + + + align:start position:0% +sort of aggregating up the intercept +terms + + align:start position:0% +terms + + + align:start position:0% +terms +and imposing the same coefficient + + align:start position:0% +and imposing the same coefficient + + + align:start position:0% +and imposing the same coefficient +on the wealth + + align:start position:0% +on the wealth + + + align:start position:0% +on the wealth +across all the households + + align:start position:0% +across all the households + + + align:start position:0% +across all the households +now do you like it or not + + align:start position:0% +now do you like it or not + + + align:start position:0% +now do you like it or not +you know it is going to require that we + + align:start position:0% +you know it is going to require that we + + + align:start position:0% +you know it is going to require that we +have these linear expansion paths if we + + align:start position:0% +have these linear expansion paths if we + + + align:start position:0% +have these linear expansion paths if we +go back to the micro economy and see how + + align:start position:0% +go back to the micro economy and see how + + + align:start position:0% +go back to the micro economy and see how +they're behaving that giving wealth to + + align:start position:0% +they're behaving that giving wealth to + + + align:start position:0% +they're behaving that giving wealth to +one guy would increase utility and + + align:start position:0% +one guy would increase utility and + + + align:start position:0% +one guy would increase utility and +consumption + + align:start position:0% +consumption + + + align:start position:0% +consumption +in exactly the same way that consumption + + align:start position:0% +in exactly the same way that consumption + + + align:start position:0% +in exactly the same way that consumption +would be decreased for the other one so + + align:start position:0% +would be decreased for the other one so + + + align:start position:0% +would be decreased for the other one so +moving wealth around because the slopes + + align:start position:0% +moving wealth around because the slopes + + + align:start position:0% +moving wealth around because the slopes +of these lines are the same they're + + align:start position:0% +of these lines are the same they're + + + align:start position:0% +of these lines are the same they're +parallel lines moving wealth around has + + align:start position:0% +parallel lines moving wealth around has + + + align:start position:0% +parallel lines moving wealth around has +no effect on aggregate demand it's just + + align:start position:0% +no effect on aggregate demand it's just + + + align:start position:0% +no effect on aggregate demand it's just +a restatement of the positive part of + + align:start position:0% +a restatement of the positive part of + + + align:start position:0% +a restatement of the positive part of +the + + align:start position:0% +the + + + align:start position:0% +the +representative consumer + + align:start position:0% +representative consumer + + + align:start position:0% +representative consumer +if you're listening to macro economists + + align:start position:0% +if you're listening to macro economists + + + align:start position:0% +if you're listening to macro economists +worried a lot about marginal propensity + + align:start position:0% +worried a lot about marginal propensity + + + align:start position:0% +worried a lot about marginal propensity +to consume out of wealth and out of + + align:start position:0% +to consume out of wealth and out of + + + align:start position:0% +to consume out of wealth and out of +transfers you know they're trying to + + align:start position:0% +transfers you know they're trying to + + + align:start position:0% +transfers you know they're trying to +find transfers to particular constrained + + align:start position:0% +find transfers to particular constrained + + + align:start position:0% +find transfers to particular constrained +households in a way that they would eat + + align:start position:0% +households in a way that they would eat + + + align:start position:0% +households in a way that they would eat +a lot as if there was a special virtue + + align:start position:0% +a lot as if there was a special virtue + + + align:start position:0% +a lot as if there was a special virtue +of pumping up aggregate demand well they + + align:start position:0% +of pumping up aggregate demand well they + + + align:start position:0% +of pumping up aggregate demand well they +don't have gorman in mind because + + align:start position:0% +don't have gorman in mind because + + + align:start position:0% +don't have gorman in mind because +aggregate demand is not determined by + + align:start position:0% +aggregate demand is not determined by + + + align:start position:0% +aggregate demand is not determined by +the distribution of wealth under gorman + + align:start position:0% +the distribution of wealth under gorman + + + align:start position:0% +the distribution of wealth under gorman +it's determined by the aggregate wealth + + align:start position:0% +it's determined by the aggregate wealth + + + align:start position:0% +it's determined by the aggregate wealth +so it wouldn't matter who you gave the + + align:start position:0% +so it wouldn't matter who you gave the + + + align:start position:0% +so it wouldn't matter who you gave the +money to if it were gorman world + + align:start position:0% +money to if it were gorman world + + + align:start position:0% +money to if it were gorman world +positive representative consumer + + align:start position:0% +positive representative consumer + + + align:start position:0% +positive representative consumer +the proof of it i'm not going to go + + align:start position:0% +the proof of it i'm not going to go + + + align:start position:0% +the proof of it i'm not going to go +through + + align:start position:0% +through + + + align:start position:0% +through +it's basically using roy's identity over + + align:start position:0% +it's basically using roy's identity over + + + align:start position:0% +it's basically using roy's identity over +and over again + + align:start position:0% +and over again + + + align:start position:0% +and over again +and exploiting the linearity + + align:start position:0% +and exploiting the linearity + + + align:start position:0% +and exploiting the linearity +adding up and then taking you know + + align:start position:0% +adding up and then taking you know + + + align:start position:0% +adding up and then taking you know +taking it back down + + align:start position:0% +taking it back down + + + align:start position:0% +taking it back down +these are examples of gorman aggregate + + align:start position:0% +these are examples of gorman aggregate + + + align:start position:0% +these are examples of gorman aggregate +preferences + + align:start position:0% +preferences + + + align:start position:0% +preferences +allowing variation in the intercepts so + + align:start position:0% +allowing variation in the intercepts so + + + align:start position:0% +allowing variation in the intercepts so +households do not have to be all alike + + align:start position:0% +households do not have to be all alike + + + align:start position:0% +households do not have to be all alike +and the normative household + + align:start position:0% +and the normative household + + + align:start position:0% +and the normative household +normative in addition to being positive + + align:start position:0% +normative in addition to being positive + + + align:start position:0% +normative in addition to being positive +is another definition + + align:start position:0% +is another definition + + + align:start position:0% +is another definition +namely + + align:start position:0% +namely + + + align:start position:0% +namely +we're looking we have the underlying + + align:start position:0% +we're looking we have the underlying + + + align:start position:0% +we're looking we have the underlying +micro economy with a heterogeneity + + align:start position:0% +micro economy with a heterogeneity + + + align:start position:0% +micro economy with a heterogeneity +across all the households + + align:start position:0% +across all the households + + + align:start position:0% +across all the households +we're looking for this fictitious + + align:start position:0% +we're looking for this fictitious + + + align:start position:0% +we're looking for this fictitious +utility function u star + + align:start position:0% +utility function u star + + + align:start position:0% +utility function u star +which we + + align:start position:0% +which we + + + align:start position:0% +which we +label the utility function of the + + align:start position:0% +label the utility function of the + + + align:start position:0% +label the utility function of the +normative representative household + + align:start position:0% +normative representative household + + + align:start position:0% +normative representative household +to satisfy two properties namely + + align:start position:0% +to satisfy two properties namely + + + align:start position:0% +to satisfy two properties namely +if we want to see if something x and y + + align:start position:0% +if we want to see if something x and y + + + align:start position:0% +if we want to see if something x and y +is pareto optimal then + + align:start position:0% +is pareto optimal then + + + align:start position:0% +is pareto optimal then +we can search for alternative + + align:start position:0% +we can search for alternative + + + align:start position:0% +we can search for alternative +allocations in parade or dominate + + align:start position:0% +allocations in parade or dominate + + + align:start position:0% +allocations in parade or dominate +in the normal micro land of all these + + align:start position:0% +in the normal micro land of all these + + + align:start position:0% +in the normal micro land of all these +different households you have to check + + align:start position:0% +different households you have to check + + + align:start position:0% +different households you have to check +out each and every one to see if they're + + align:start position:0% +out each and every one to see if they're + + + align:start position:0% +out each and every one to see if they're +better off + + align:start position:0% +better off + + + align:start position:0% +better off +under the proposed alternative + + align:start position:0% +under the proposed alternative + + + align:start position:0% +under the proposed alternative +with gorman + + align:start position:0% +with gorman + + + align:start position:0% +with gorman +normative you don't have to do that you + + align:start position:0% +normative you don't have to do that you + + + align:start position:0% +normative you don't have to do that you +just sum up all the demands in the + + align:start position:0% +just sum up all the demands in the + + + align:start position:0% +just sum up all the demands in the +baseline + + align:start position:0% +baseline + + + align:start position:0% +baseline +and in the alternative + + align:start position:0% +and in the alternative + + + align:start position:0% +and in the alternative +and evaluate that sum under this + + align:start position:0% +and evaluate that sum under this + + + align:start position:0% +and evaluate that sum under this +mythical utility function u star + + align:start position:0% +mythical utility function u star + + + align:start position:0% +mythical utility function u star +so + + align:start position:0% +so + + + align:start position:0% +so +if something creator dominates then it + + align:start position:0% +if something creator dominates then it + + + align:start position:0% +if something creator dominates then it +has to have a higher return under ustar + + align:start position:0% +has to have a higher return under ustar + + + align:start position:0% +has to have a higher return under ustar +so that makes the search a whole lot + + align:start position:0% +so that makes the search a whole lot + + + align:start position:0% +so that makes the search a whole lot +easier + + align:start position:0% +easier + + + align:start position:0% +easier +and the flip side is the same + + align:start position:0% +and the flip side is the same + + + align:start position:0% +and the flip side is the same +with an important caveat + + align:start position:0% +with an important caveat + + + align:start position:0% +with an important caveat +you start with a baseline and you find a + + align:start position:0% +you start with a baseline and you find a + + + align:start position:0% +you start with a baseline and you find a +prime allocation + + align:start position:0% +prime allocation + + + align:start position:0% +prime allocation +which is dominant under u star after you + + align:start position:0% +which is dominant under u star after you + + + align:start position:0% +which is dominant under u star after you +sum up then we should be able to do + + align:start position:0% +sum up then we should be able to do + + + align:start position:0% +sum up then we should be able to do +better so there there is a way in the + + align:start position:0% +better so there there is a way in the + + + align:start position:0% +better so there there is a way in the +micro space + + align:start position:0% +micro space + + + align:start position:0% +micro space +to assign + + align:start position:0% +to assign + + + align:start position:0% +to assign +allocations + + align:start position:0% +allocations + + + align:start position:0% +allocations +that add up to the prime bundle but are + + align:start position:0% +that add up to the prime bundle but are + + + align:start position:0% +that add up to the prime bundle but are +not necessarily the actual prime + + align:start position:0% +not necessarily the actual prime + + + align:start position:0% +not necessarily the actual prime +allocation a way to do that in such a + + align:start position:0% +allocation a way to do that in such a + + + align:start position:0% +allocation a way to do that in such a +way that everyone is at least as well + + align:start position:0% +way that everyone is at least as well + + + align:start position:0% +way that everyone is at least as well +off and some people are better off + + align:start position:0% +off and some people are better off + + + align:start position:0% +off and some people are better off +so the point of this is + + align:start position:0% +so the point of this is + + + align:start position:0% +so the point of this is +it's very strong when it works it's a + + align:start position:0% +it's very strong when it works it's a + + + align:start position:0% +it's very strong when it works it's a +way of evaluating allocations but is it + + align:start position:0% +way of evaluating allocations but is it + + + align:start position:0% +way of evaluating allocations but is it +is not to say that you don't have to + + align:start position:0% +is not to say that you don't have to + + + align:start position:0% +is not to say that you don't have to +worry about the distribution + + align:start position:0% +worry about the distribution + + + align:start position:0% +worry about the distribution +you could make people better off as i've + + align:start position:0% +you could make people better off as i've + + + align:start position:0% +you could make people better off as i've +said before i think when i gave this + + align:start position:0% +said before i think when i gave this + + + align:start position:0% +said before i think when i gave this +lecture free trade could make everyone + + align:start position:0% +lecture free trade could make everyone + + + align:start position:0% +lecture free trade could make everyone +better off but you shouldn't stop there + + align:start position:0% +better off but you shouldn't stop there + + + align:start position:0% +better off but you shouldn't stop there +because even under gorman you have to + + align:start position:0% +because even under gorman you have to + + + align:start position:0% +because even under gorman you have to +redistribute + + align:start position:0% +redistribute + + + align:start position:0% +redistribute +wealth in such a way as to to let it + + align:start position:0% +wealth in such a way as to to let it + + + align:start position:0% +wealth in such a way as to to let it +pareto dominate the + + align:start position:0% +pareto dominate the + + + align:start position:0% +pareto dominate the +tariff equilibrium + + align:start position:0% +tariff equilibrium + + + align:start position:0% +tariff equilibrium +maybe that's a lesson that trait + + align:start position:0% +maybe that's a lesson that trait + + + align:start position:0% +maybe that's a lesson that trait +theorists kind of forgot to emphasize + + align:start position:0% +theorists kind of forgot to emphasize + + + align:start position:0% +theorists kind of forgot to emphasize +so we did this in + + align:start position:0% +so we did this in + + + align:start position:0% +so we did this in +we actually did the proof in the space + + align:start position:0% +we actually did the proof in the space + + + align:start position:0% +we actually did the proof in the space +of indirect utilities and again i don't + + align:start position:0% +of indirect utilities and again i don't + + + align:start position:0% +of indirect utilities and again i don't +want to + + align:start position:0% +want to + + + align:start position:0% +want to +go through that too much + + align:start position:0% +go through that too much + + + align:start position:0% +go through that too much +so at the end we have the application of + + align:start position:0% +so at the end we have the application of + + + align:start position:0% +so at the end we have the application of +those positive and normative + + align:start position:0% +those positive and normative + + + align:start position:0% +those positive and normative +representative consumers to this slide + + align:start position:0% +representative consumers to this slide + + + align:start position:0% +representative consumers to this slide +this is the third time that i've shown + + align:start position:0% +this is the third time that i've shown + + + align:start position:0% +this is the third time that i've shown +you this economy + + align:start position:0% +you this economy + + + align:start position:0% +you this economy +and at least maybe the third time we + + align:start position:0% +and at least maybe the third time we + + + align:start position:0% +and at least maybe the third time we +talked about the pareto problem in this + + align:start position:0% +talked about the pareto problem in this + + + align:start position:0% +talked about the pareto problem in this +economy this pareto problem of course + + align:start position:0% +economy this pareto problem of course + + + align:start position:0% +economy this pareto problem of course +has the lambda weights as well it should + + align:start position:0% +has the lambda weights as well it should + + + align:start position:0% +has the lambda weights as well it should +but if we have a positive and normative + + align:start position:0% +but if we have a positive and normative + + + align:start position:0% +but if we have a positive and normative +representative consumer + + align:start position:0% +representative consumer + + + align:start position:0% +representative consumer +then amazingly we can drop the pareto + + align:start position:0% +then amazingly we can drop the pareto + + + align:start position:0% +then amazingly we can drop the pareto +weights and just maximize u-star + + align:start position:0% +weights and just maximize u-star + + + align:start position:0% +weights and just maximize u-star +so it's as if there's a single + + align:start position:0% +so it's as if there's a single + + + align:start position:0% +so it's as if there's a single +representative consumer with an + + align:start position:0% +representative consumer with an + + + align:start position:0% +representative consumer with an +aggregated production technology like + + align:start position:0% +aggregated production technology like + + + align:start position:0% +aggregated production technology like +robinson crusoe and this is a much much + + align:start position:0% +robinson crusoe and this is a much much + + + align:start position:0% +robinson crusoe and this is a much much +easier problem to solve hence the power + + align:start position:0% +easier problem to solve hence the power + + + align:start position:0% +easier problem to solve hence the power +of it for macro + + align:start position:0% +of it for macro + + + align:start position:0% +of it for macro +because we're solving it in the space of + + align:start position:0% +because we're solving it in the space of + + + align:start position:0% +because we're solving it in the space of +macros and again typically people forget + + align:start position:0% +macros and again typically people forget + + + align:start position:0% +macros and again typically people forget +to think about the underlying + + align:start position:0% +to think about the underlying + + + align:start position:0% +to think about the underlying +distribution and the underlying wealth + + align:start position:0% +distribution and the underlying wealth + + + align:start position:0% +distribution and the underlying wealth +distribution of welfare gains + + align:start position:0% +distribution of welfare gains + + + align:start position:0% +distribution of welfare gains +that and maybe even losses to sort of + + align:start position:0% +that and maybe even losses to sort of + + + align:start position:0% +that and maybe even losses to sort of +stick with the aggregates + + align:start position:0% +stick with the aggregates + + + align:start position:0% +stick with the aggregates +so are there any questions about lecture + + align:start position:0% +so are there any questions about lecture + + + align:start position:0% +so are there any questions about lecture +18. + + align:start position:0% + + + + align:start position:0% + +19 went the other direction and i paired + + align:start position:0% +19 went the other direction and i paired + + + align:start position:0% +19 went the other direction and i paired +them deliberately + + align:start position:0% +them deliberately + + + align:start position:0% +them deliberately +instead of saying look at all the + + align:start position:0% +instead of saying look at all the + + + align:start position:0% +instead of saying look at all the +special things you can do if you assume + + align:start position:0% +special things you can do if you assume + + + align:start position:0% +special things you can do if you assume +special structure like linear income + + align:start position:0% +special structure like linear income + + + align:start position:0% +special structure like linear income +expansion pass + + align:start position:0% +expansion pass + + + align:start position:0% +expansion pass +let's try to avoid any restrictions + + align:start position:0% +let's try to avoid any restrictions + + + align:start position:0% +let's try to avoid any restrictions +whatsoever on utility and production + + align:start position:0% +whatsoever on utility and production + + + align:start position:0% +whatsoever on utility and production +sets and so on and still see whether + + align:start position:0% +sets and so on and still see whether + + + align:start position:0% +sets and so on and still see whether +we can say anything at all + + align:start position:0% +we can say anything at all + + + align:start position:0% +we can say anything at all +so the spirit of this is very different + + align:start position:0% +so the spirit of this is very different + + + align:start position:0% +so the spirit of this is very different +from the previous lecture this is about + + align:start position:0% +from the previous lecture this is about + + + align:start position:0% +from the previous lecture this is about +not assuming gorman aggregation we're + + align:start position:0% +not assuming gorman aggregation we're + + + align:start position:0% +not assuming gorman aggregation we're +not even assuming + + align:start position:0% +not even assuming + + + align:start position:0% +not even assuming +anything much at all about expansion + + align:start position:0% +anything much at all about expansion + + + align:start position:0% +anything much at all about expansion +paths + + align:start position:0% +paths + + + align:start position:0% +paths +could have gift and goods + + align:start position:0% +could have gift and goods + + + align:start position:0% +could have gift and goods +what can what if anything can we say or + + align:start position:0% +what can what if anything can we say or + + + align:start position:0% +what can what if anything can we say or +given data can we just always accept + + align:start position:0% +given data can we just always accept + + + align:start position:0% +given data can we just always accept +that there's an economy that would have + + align:start position:0% +that there's an economy that would have + + + align:start position:0% +that there's an economy that would have +generated the data + + align:start position:0% +generated the data + + + align:start position:0% +generated the data +and we've talked about this + + align:start position:0% +and we've talked about this + + + align:start position:0% +and we've talked about this +at the beginning of the following class + + align:start position:0% +at the beginning of the following class + + + align:start position:0% +at the beginning of the following class +so we want to put as little structure as + + align:start position:0% +so we want to put as little structure as + + + align:start position:0% +so we want to put as little structure as +possible and we did this + + align:start position:0% +possible and we did this + + + align:start position:0% +possible and we did this +a couple of ways with an infinite amount + + align:start position:0% +a couple of ways with an infinite amount + + + align:start position:0% +a couple of ways with an infinite amount +of data with a finite amount of data we + + align:start position:0% +of data with a finite amount of data we + + + align:start position:0% +of data with a finite amount of data we +did it in partial equilibrium under + + align:start position:0% +did it in partial equilibrium under + + + align:start position:0% +did it in partial equilibrium under +consumer choice and then we made some + + align:start position:0% +consumer choice and then we made some + + + align:start position:0% +consumer choice and then we made some +connections to + + align:start position:0% +connections to + + + align:start position:0% +connections to +to general equilibrium theory + + align:start position:0% +to general equilibrium theory + + + align:start position:0% +to general equilibrium theory +the slotsky thing + + align:start position:0% +the slotsky thing + + + align:start position:0% +the slotsky thing +came from a property namely that we + + align:start position:0% +came from a property namely that we + + + align:start position:0% +came from a property namely that we +minimized the expenditure necessary to + + align:start position:0% +minimized the expenditure necessary to + + + align:start position:0% +minimized the expenditure necessary to +achieve a certain level of utility + + align:start position:0% +achieve a certain level of utility + + + align:start position:0% +achieve a certain level of utility +that expenditure function is concave + + align:start position:0% +that expenditure function is concave + + + align:start position:0% +that expenditure function is concave +and then the derivative of the + + align:start position:0% +and then the derivative of the + + + align:start position:0% +and then the derivative of the +expenditure function + + align:start position:0% +expenditure function + + + align:start position:0% +expenditure function +a bit like roy's identity not quite is + + align:start position:0% +a bit like roy's identity not quite is + + + align:start position:0% +a bit like roy's identity not quite is +the hixing demands + + align:start position:0% +the hixing demands + + + align:start position:0% +the hixing demands +so the second derivative of the + + align:start position:0% +so the second derivative of the + + + align:start position:0% +so the second derivative of the +expenditure function a matrix really + + align:start position:0% +expenditure function a matrix really + + + align:start position:0% +expenditure function a matrix really +across partial derivatives has to be + + align:start position:0% +across partial derivatives has to be + + + align:start position:0% +across partial derivatives has to be +symmetric and negative semi-definite + + align:start position:0% +symmetric and negative semi-definite + + + align:start position:0% +symmetric and negative semi-definite +this statement is what led to the + + align:start position:0% +this statement is what led to the + + + align:start position:0% +this statement is what led to the +slutsky equation this is a version of + + align:start position:0% +slutsky equation this is a version of + + + align:start position:0% +slutsky equation this is a version of +that equation i guess for the purposes + + align:start position:0% +that equation i guess for the purposes + + + align:start position:0% +that equation i guess for the purposes +of the lecture in terms of + + align:start position:0% +of the lecture in terms of + + + align:start position:0% +of the lecture in terms of +what's the point of it all one is we get + + align:start position:0% +what's the point of it all one is we get + + + align:start position:0% +what's the point of it all one is we get +restrictions from the data + + align:start position:0% +restrictions from the data + + + align:start position:0% +restrictions from the data +assuming preferences are + + align:start position:0% +assuming preferences are + + + align:start position:0% +assuming preferences are +regular + + align:start position:0% +regular + + + align:start position:0% +regular +we get restrictions on + + align:start position:0% +we get restrictions on + + + align:start position:0% +we get restrictions on +something we never see + + align:start position:0% +something we never see + + + align:start position:0% +something we never see +namely these compensated hixi and demand + + align:start position:0% +namely these compensated hixi and demand + + + align:start position:0% +namely these compensated hixi and demand +functions as i think we went through in + + align:start position:0% +functions as i think we went through in + + + align:start position:0% +functions as i think we went through in +lecture three + + align:start position:0% +lecture three + + + align:start position:0% +lecture three +but fortunately we're able to write out + + align:start position:0% +but fortunately we're able to write out + + + align:start position:0% +but fortunately we're able to write out +the left-hand side + + align:start position:0% +the left-hand side + + + align:start position:0% +the left-hand side +the slutsky derivative cross-partial + + align:start position:0% +the slutsky derivative cross-partial + + + align:start position:0% +the slutsky derivative cross-partial +derivatives in terms of observables on + + align:start position:0% +derivatives in terms of observables on + + + align:start position:0% +derivatives in terms of observables on +the right-hand side which are directly + + align:start position:0% +the right-hand side which are directly + + + align:start position:0% +the right-hand side which are directly +from the consumer's optimization problem + + align:start position:0% +from the consumer's optimization problem + + + align:start position:0% +from the consumer's optimization problem +how demand changes with prices + + align:start position:0% +how demand changes with prices + + + align:start position:0% +how demand changes with prices +how demands change with wealth and of + + align:start position:0% +how demands change with wealth and of + + + align:start position:0% +how demands change with wealth and of +course we would be observing the actual + + align:start position:0% +course we would be observing the actual + + + align:start position:0% +course we would be observing the actual +allocations this is with infinite data + + align:start position:0% +allocations this is with infinite data + + + align:start position:0% +allocations this is with infinite data +so again we're allowed conceptually to + + align:start position:0% +so again we're allowed conceptually to + + + align:start position:0% +so again we're allowed conceptually to +think about + + align:start position:0% +think about + + + align:start position:0% +think about +having all these derivatives + + align:start position:0% +having all these derivatives + + + align:start position:0% +having all these derivatives +for infinite testimony small changes + + align:start position:0% +for infinite testimony small changes + + + align:start position:0% +for infinite testimony small changes +available to us + + align:start position:0% +available to us + + + align:start position:0% +available to us +and again + + align:start position:0% +and again + + + align:start position:0% +and again +as i went through in class from lecture + + align:start position:0% +as i went through in class from lecture + + + align:start position:0% +as i went through in class from lecture +three + + align:start position:0% +three + + + align:start position:0% +three +when we did the income and substitution + + align:start position:0% +when we did the income and substitution + + + align:start position:0% +when we did the income and substitution +effects we kind of had written + + align:start position:0% +effects we kind of had written + + + align:start position:0% +effects we kind of had written +with the s on the right hand side and d + + align:start position:0% +with the s on the right hand side and d + + + align:start position:0% +with the s on the right hand side and d +x d p on the left hand side + + align:start position:0% +x d p on the left hand side + + + align:start position:0% +x d p on the left hand side +so there was a negative sign but it's + + align:start position:0% +so there was a negative sign but it's + + + align:start position:0% +so there was a negative sign but it's +all the same + + align:start position:0% +all the same + + + align:start position:0% +all the same +it's all equivalent + + align:start position:0% +it's all equivalent + + + align:start position:0% +it's all equivalent +okay so then + + align:start position:0% +okay so then + + + align:start position:0% +okay so then +we're saying like slutsky would be + + align:start position:0% +we're saying like slutsky would be + + + align:start position:0% +we're saying like slutsky would be +satisfied and a couple of other things + + align:start position:0% +satisfied and a couple of other things + + + align:start position:0% +satisfied and a couple of other things +are satisfied if we have + + align:start position:0% +are satisfied if we have + + + align:start position:0% +are satisfied if we have +the premise of an underlying + + align:start position:0% +the premise of an underlying + + + align:start position:0% +the premise of an underlying +rational consumer maximizing utility and + + align:start position:0% +rational consumer maximizing utility and + + + align:start position:0% +rational consumer maximizing utility and +we reviewed this in the discussion + + align:start position:0% +we reviewed this in the discussion + + + align:start position:0% +we reviewed this in the discussion +of the subsequent class we have + + align:start position:0% +of the subsequent class we have + + + align:start position:0% +of the subsequent class we have +homogeneity of degree zero + + align:start position:0% +homogeneity of degree zero + + + align:start position:0% +homogeneity of degree zero +and vol ross law spending your budget + + align:start position:0% +and vol ross law spending your budget + + + align:start position:0% +and vol ross law spending your budget +no price solution and spending and being + + align:start position:0% +no price solution and spending and being + + + align:start position:0% +no price solution and spending and being +on the budget line that plus slutsky are + + align:start position:0% +on the budget line that plus slutsky are + + + align:start position:0% +on the budget line that plus slutsky are +the restrictions + + align:start position:0% +the restrictions + + + align:start position:0% +the restrictions +implied by having a + + align:start position:0% +implied by having a + + + align:start position:0% +implied by having a +utility maximizing rational household + + align:start position:0% +utility maximizing rational household + + + align:start position:0% +utility maximizing rational household +and it turned out + + align:start position:0% +and it turned out + + + align:start position:0% +and it turned out +that it goes the other way as well + + align:start position:0% +that it goes the other way as well + + + align:start position:0% +that it goes the other way as well +that is to say if you had data that + + align:start position:0% +that is to say if you had data that + + + align:start position:0% +that is to say if you had data that +satisfied these three properties then + + align:start position:0% +satisfied these three properties then + + + align:start position:0% +satisfied these three properties then +there would be an underlying utility + + align:start position:0% +there would be an underlying utility + + + align:start position:0% +there would be an underlying utility +function that's + + align:start position:0% +function that's + + + align:start position:0% +function that's +quasi-concave increasing and so on that + + align:start position:0% +quasi-concave increasing and so on that + + + align:start position:0% +quasi-concave increasing and so on that +would have generated the data + + align:start position:0% +would have generated the data + + + align:start position:0% +would have generated the data +so this kind of seemingly bears some + + align:start position:0% +so this kind of seemingly bears some + + + align:start position:0% +so this kind of seemingly bears some +similarity to gorman in the sense of + + align:start position:0% +similarity to gorman in the sense of + + + align:start position:0% +similarity to gorman in the sense of +could we generate the aggregate demand + + align:start position:0% +could we generate the aggregate demand + + + align:start position:0% +could we generate the aggregate demand +by maximizing a utility function + + align:start position:0% +by maximizing a utility function + + + align:start position:0% +by maximizing a utility function +could we find a utility function u star + + align:start position:0% +could we find a utility function u star + + + align:start position:0% +could we find a utility function u star +such that given the household all the + + align:start position:0% +such that given the household all the + + + align:start position:0% +such that given the household all the +wealth the solution of that problem + + align:start position:0% +wealth the solution of that problem + + + align:start position:0% +wealth the solution of that problem +would be the underlying demands here + + align:start position:0% +would be the underlying demands here + + + align:start position:0% +would be the underlying demands here +though we're giving the the data + + align:start position:0% +though we're giving the the data + + + align:start position:0% +though we're giving the the data +including demands + + align:start position:0% +including demands + + + align:start position:0% +including demands +for a given household and trying to find + + align:start position:0% +for a given household and trying to find + + + align:start position:0% +for a given household and trying to find +whether or not there exists a utility + + align:start position:0% +whether or not there exists a utility + + + align:start position:0% +whether or not there exists a utility +function that would generate demands + + align:start position:0% +function that would generate demands + + + align:start position:0% +function that would generate demands +with all these properties and the answer + + align:start position:0% +with all these properties and the answer + + + align:start position:0% +with all these properties and the answer +is yes + + align:start position:0% +is yes + + + align:start position:0% +is yes +that it's sufficient and necessary to + + align:start position:0% +that it's sufficient and necessary to + + + align:start position:0% +that it's sufficient and necessary to +have these properties + + align:start position:0% +have these properties + + + align:start position:0% +have these properties +so the theory has content you just need + + align:start position:0% +so the theory has content you just need + + + align:start position:0% +so the theory has content you just need +to scroll through this list in the data + + align:start position:0% +to scroll through this list in the data + + + align:start position:0% +to scroll through this list in the data +and see if you can + + align:start position:0% +and see if you can + + + align:start position:0% +and see if you can +violate one of them + + align:start position:0% +violate one of them + + + align:start position:0% +violate one of them +and it would it could not have had come + + align:start position:0% +and it would it could not have had come + + + align:start position:0% +and it would it could not have had come +from a maximizing household + + align:start position:0% +from a maximizing household + + + align:start position:0% +from a maximizing household +convexity was not testable + + align:start position:0% +convexity was not testable + + + align:start position:0% +convexity was not testable +not with this demand theory + + align:start position:0% +not with this demand theory + + + align:start position:0% +not with this demand theory +because you generate the same data and + + align:start position:0% +because you generate the same data and + + + align:start position:0% +because you generate the same data and +we actually made a connection to + + align:start position:0% +we actually made a connection to + + + align:start position:0% +we actually made a connection to +computer science + + align:start position:0% +computer science + + + align:start position:0% +computer science +so this part this is testing with finite + + align:start position:0% +so this part this is testing with finite + + + align:start position:0% +so this part this is testing with finite +data not an infinite amount of data and + + align:start position:0% +data not an infinite amount of data and + + + align:start position:0% +data not an infinite amount of data and +the key here was the beginning at least + + align:start position:0% +the key here was the beginning at least + + + align:start position:0% +the key here was the beginning at least +this weak axiom of revealed preference + + align:start position:0% +this weak axiom of revealed preference + + + align:start position:0% +this weak axiom of revealed preference +which you should all know + + align:start position:0% +which you should all know + + + align:start position:0% +which you should all know +and again we reviewed it in the + + align:start position:0% +and again we reviewed it in the + + + align:start position:0% +and again we reviewed it in the +subsequent lecture at the beginning + + align:start position:0% +subsequent lecture at the beginning + + + align:start position:0% +subsequent lecture at the beginning +that that sort of pairwise if we have + + align:start position:0% +that that sort of pairwise if we have + + + align:start position:0% +that that sort of pairwise if we have +two observations + + align:start position:0% +two observations + + + align:start position:0% +two observations +prices and + + align:start position:0% +prices and + + + align:start position:0% +prices and +demands in situation one in situation + + align:start position:0% +demands in situation one in situation + + + align:start position:0% +demands in situation one in situation +two + + align:start position:0% +two + + + align:start position:0% +two +then a price p2 if they're observed + + align:start position:0% +then a price p2 if they're observed + + + align:start position:0% +then a price p2 if they're observed +choosing x2 it better be the case + + align:start position:0% +choosing x2 it better be the case + + + align:start position:0% +choosing x2 it better be the case +and x1 was available and not chosen it + + align:start position:0% +and x1 was available and not chosen it + + + align:start position:0% +and x1 was available and not chosen it +better be the case that price is p1 + + align:start position:0% +better be the case that price is p1 + + + align:start position:0% +better be the case that price is p1 +where they're choosing x1 they don't + + align:start position:0% +where they're choosing x1 they don't + + + align:start position:0% +where they're choosing x1 they don't +have x2 available otherwise they they + + align:start position:0% +have x2 available otherwise they they + + + align:start position:0% +have x2 available otherwise they they +were supposed to have chosen it if it + + align:start position:0% +were supposed to have chosen it if it + + + align:start position:0% +were supposed to have chosen it if it +had been interior in the budget + + align:start position:0% +had been interior in the budget + + + align:start position:0% +had been interior in the budget +according to the first statement it + + align:start position:0% +according to the first statement it + + + align:start position:0% +according to the first statement it +would be utility maximizing + + align:start position:0% +would be utility maximizing + + + align:start position:0% +would be utility maximizing +so this is putting restrictions on data + + align:start position:0% +so this is putting restrictions on data + + + align:start position:0% +so this is putting restrictions on data +the the weak axiom of real preferences + + align:start position:0% +the the weak axiom of real preferences + + + align:start position:0% +the the weak axiom of real preferences +looking at pairwise observations as we + + align:start position:0% +looking at pairwise observations as we + + + align:start position:0% +looking at pairwise observations as we +move prices and demands around + + align:start position:0% +move prices and demands around + + + align:start position:0% +move prices and demands around +to see if it's quote rational + + align:start position:0% +to see if it's quote rational + + + align:start position:0% +to see if it's quote rational +weak axiom of revealed preference + + align:start position:0% +weak axiom of revealed preference + + + align:start position:0% +weak axiom of revealed preference +and then we generalize that that + + align:start position:0% +and then we generalize that that + + + align:start position:0% +and then we generalize that that +we called those directly revealed + + align:start position:0% +we called those directly revealed + + + align:start position:0% +we called those directly revealed +preferred pairwise comparisons + + align:start position:0% +preferred pairwise comparisons + + + align:start position:0% +preferred pairwise comparisons +and then we + + align:start position:0% +and then we + + + align:start position:0% +and then we +went on to talk about + + align:start position:0% +went on to talk about + + + align:start position:0% +went on to talk about +indirectly revealed preferred or just + + align:start position:0% +indirectly revealed preferred or just + + + align:start position:0% +indirectly revealed preferred or just +revealed preferred + + align:start position:0% +revealed preferred + + + align:start position:0% +revealed preferred +and + + align:start position:0% +and + + + align:start position:0% +and +the content of this was we never see all + + align:start position:0% +the content of this was we never see all + + + align:start position:0% +the content of this was we never see all +the pairwise comparisons + + align:start position:0% +the pairwise comparisons + + + align:start position:0% +the pairwise comparisons +we never see + + align:start position:0% +we never see + + + align:start position:0% +we never see +you know + + align:start position:0% +you know + + + align:start position:0% +you know +xt directly + + align:start position:0% +xt directly + + + align:start position:0% +xt directly +compared to xs but we do see it + + align:start position:0% +compared to xs but we do see it + + + align:start position:0% +compared to xs but we do see it +indirectly + + align:start position:0% +indirectly + + + align:start position:0% +indirectly +because we have xt + + align:start position:0% +because we have xt + + + align:start position:0% +because we have xt +in this case revealed directly preferred + + align:start position:0% +in this case revealed directly preferred + + + align:start position:0% +in this case revealed directly preferred +to xr1 xr1 revealed preferred xr2 + + align:start position:0% +to xr1 xr1 revealed preferred xr2 + + + align:start position:0% +to xr1 xr1 revealed preferred xr2 +and so on down the chain + + align:start position:0% +and so on down the chain + + + align:start position:0% +and so on down the chain +so + + align:start position:0% +so + + + align:start position:0% +so +under one of those + + align:start position:0% +under one of those + + + align:start position:0% +under one of those +properties of a rational consumer + + align:start position:0% +properties of a rational consumer + + + align:start position:0% +properties of a rational consumer +namely transitivity + + align:start position:0% +namely transitivity + + + align:start position:0% +namely transitivity +if we had a sequence of revealed + + align:start position:0% +if we had a sequence of revealed + + + align:start position:0% +if we had a sequence of revealed +directly preferred + + align:start position:0% +directly preferred + + + align:start position:0% +directly preferred +and under transitivity xt should be + + align:start position:0% +and under transitivity xt should be + + + align:start position:0% +and under transitivity xt should be +revealed preferred + + align:start position:0% +revealed preferred + + + align:start position:0% +revealed preferred +directly preferred xs too so when you + + align:start position:0% +directly preferred xs too so when you + + + align:start position:0% +directly preferred xs too so when you +can do the pairwise comparison at tns + + align:start position:0% +can do the pairwise comparison at tns + + + align:start position:0% +can do the pairwise comparison at tns +it better be the case they don't they + + align:start position:0% +it better be the case they don't they + + + align:start position:0% +it better be the case they don't they +don't violate that xt is preferred x + + align:start position:0% +don't violate that xt is preferred x + + + align:start position:0% +don't violate that xt is preferred x +weekly preferred xs + + align:start position:0% +weekly preferred xs + + + align:start position:0% +weekly preferred xs +so this second part + + align:start position:0% +so this second part + + + align:start position:0% +so this second part +is + + align:start position:0% +is + + + align:start position:0% +is +assuming underlying consumer rationality + + align:start position:0% +assuming underlying consumer rationality + + + align:start position:0% +assuming underlying consumer rationality +in order to set up a situation where we + + align:start position:0% +in order to set up a situation where we + + + align:start position:0% +in order to set up a situation where we +can actually impose the test + + align:start position:0% +can actually impose the test + + + align:start position:0% +can actually impose the test +then we did that in computational + + align:start position:0% +then we did that in computational + + + align:start position:0% +then we did that in computational +economics + + align:start position:0% +economics + + + align:start position:0% +economics +which i mentioned i elaborated on in the + + align:start position:0% +which i mentioned i elaborated on in the + + + align:start position:0% +which i mentioned i elaborated on in the +subsequent lecture + + align:start position:0% +subsequent lecture + + + align:start position:0% +subsequent lecture +and we took it to general equilibrium so + + align:start position:0% +and we took it to general equilibrium so + + + align:start position:0% +and we took it to general equilibrium so +are there any + + align:start position:0% +are there any + + + align:start position:0% +are there any +questions about and risk sharing any + + align:start position:0% +questions about and risk sharing any + + + align:start position:0% +questions about and risk sharing any +questions about + + align:start position:0% +questions about + + + align:start position:0% +questions about +lecture 19. + + align:start position:0% + + + + align:start position:0% + +these reviews get faster and faster as + + align:start position:0% +these reviews get faster and faster as + + + align:start position:0% +these reviews get faster and faster as +we approach the end of the hour + + align:start position:0% +we approach the end of the hour + + + align:start position:0% +we approach the end of the hour +but on the other hand it's more and more + + align:start position:0% +but on the other hand it's more and more + + + align:start position:0% +but on the other hand it's more and more +recent so not so worried + + align:start position:0% +recent so not so worried + + + align:start position:0% +recent so not so worried +21 we already did so that just leaves us + + align:start position:0% +21 we already did so that just leaves us + + + align:start position:0% +21 we already did so that just leaves us +with 20 + + align:start position:0% +with 20 + + + align:start position:0% +with 20 +and 20 is pretty familiar + + align:start position:0% +and 20 is pretty familiar + + + align:start position:0% +and 20 is pretty familiar +which was + + align:start position:0% +which was + + + align:start position:0% +which was +the failure of the welfare theorem so we + + align:start position:0% +the failure of the welfare theorem so we + + + align:start position:0% +the failure of the welfare theorem so we +kind of covered + + align:start position:0% +kind of covered + + + align:start position:0% +kind of covered +sufficient assumptions already + + align:start position:0% +sufficient assumptions already + + + align:start position:0% +sufficient assumptions already +and then + + align:start position:0% +and then + + + align:start position:0% +and then +for the fourth third or fourth time i'm + + align:start position:0% +for the fourth third or fourth time i'm + + + align:start position:0% +for the fourth third or fourth time i'm +showing you this economy again + + align:start position:0% +showing you this economy again + + + align:start position:0% +showing you this economy again +in all of its glory with the convexity + + align:start position:0% +in all of its glory with the convexity + + + align:start position:0% +in all of its glory with the convexity +and + + align:start position:0% +and + + + align:start position:0% +and +concavity + + align:start position:0% +concavity + + + align:start position:0% +concavity +in the appropriate spots + + align:start position:0% +in the appropriate spots + + + align:start position:0% +in the appropriate spots +statement of the second welfare theorem + + align:start position:0% +statement of the second welfare theorem + + + align:start position:0% +statement of the second welfare theorem +you actually saw this slide before in + + align:start position:0% +you actually saw this slide before in + + + align:start position:0% +you actually saw this slide before in +the review today + + align:start position:0% +the review today + + + align:start position:0% +the review today +and the second welfare theorem + + align:start position:0% +and the second welfare theorem + + + align:start position:0% +and the second welfare theorem +says that + + align:start position:0% +says that + + + align:start position:0% +says that +any pareto optimum + + align:start position:0% +any pareto optimum + + + align:start position:0% +any pareto optimum +can be supported as a volrazian + + align:start position:0% +can be supported as a volrazian + + + align:start position:0% +can be supported as a volrazian +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +so here's a case where everything's + + align:start position:0% +so here's a case where everything's + + + align:start position:0% +so here's a case where everything's +working out fine + + align:start position:0% +working out fine + + + align:start position:0% +working out fine +here's the pareto optimum obviously + + align:start position:0% +here's the pareto optimum obviously + + + align:start position:0% +here's the pareto optimum obviously +this is the supporting hyperplane again + + align:start position:0% +this is the supporting hyperplane again + + + align:start position:0% +this is the supporting hyperplane again +so it's going to be a competitive + + align:start position:0% +so it's going to be a competitive + + + align:start position:0% +so it's going to be a competitive +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +but + + align:start position:0% +but + + + align:start position:0% +but +the second welfare theorem + + align:start position:0% +the second welfare theorem + + + align:start position:0% +the second welfare theorem +has a sufficient assumption is the + + align:start position:0% +has a sufficient assumption is the + + + align:start position:0% +has a sufficient assumption is the +convexity + + align:start position:0% +convexity + + + align:start position:0% +convexity +so + + align:start position:0% +so + + + align:start position:0% +so +as i said i think last time or in answer + + align:start position:0% +as i said i think last time or in answer + + + align:start position:0% +as i said i think last time or in answer +to this + + align:start position:0% +to this + + + align:start position:0% +to this +that second to last time + + align:start position:0% +that second to last time + + + align:start position:0% +that second to last time +you know the starting point here is + + align:start position:0% +you know the starting point here is + + + align:start position:0% +you know the starting point here is +something that's pareto optimal and it's + + align:start position:0% +something that's pareto optimal and it's + + + align:start position:0% +something that's pareto optimal and it's +easy to lose track of the direction of + + align:start position:0% +easy to lose track of the direction of + + + align:start position:0% +easy to lose track of the direction of +the argument + + align:start position:0% +the argument + + + align:start position:0% +the argument +is this pareto optimal yes it certainly + + align:start position:0% +is this pareto optimal yes it certainly + + + align:start position:0% +is this pareto optimal yes it certainly +is or at least you can imagine so + + align:start position:0% +is or at least you can imagine so + + + align:start position:0% +is or at least you can imagine so +this is the indifference curve that's + + align:start position:0% +this is the indifference curve that's + + + align:start position:0% +this is the indifference curve that's +tangent locally and you could try to + + align:start position:0% +tangent locally and you could try to + + + align:start position:0% +tangent locally and you could try to +move away from there globally + + align:start position:0% +move away from there globally + + + align:start position:0% +move away from there globally +but whatever you do + + align:start position:0% +but whatever you do + + + align:start position:0% +but whatever you do +it has to be on this production set to + + align:start position:0% +it has to be on this production set to + + + align:start position:0% +it has to be on this production set to +be feasible + + align:start position:0% +be feasible + + + align:start position:0% +be feasible +and that's going to be + + align:start position:0% +and that's going to be + + + align:start position:0% +and that's going to be +associated with a lower level of an + + align:start position:0% +associated with a lower level of an + + + align:start position:0% +associated with a lower level of an +indifference curve so this is the best + + align:start position:0% +indifference curve so this is the best + + + align:start position:0% +indifference curve so this is the best +level of utility achievable within and + + align:start position:0% +level of utility achievable within and + + + align:start position:0% +level of utility achievable within and +on the production set and likewise over + + align:start position:0% +on the production set and likewise over + + + align:start position:0% +on the production set and likewise over +here oh + + align:start position:0% +here oh + + + align:start position:0% +here oh +but then the second forgetting the + + align:start position:0% +but then the second forgetting the + + + align:start position:0% +but then the second forgetting the +second part of the theorem is + + align:start position:0% +second part of the theorem is + + + align:start position:0% +second part of the theorem is +can it be supported as a competitive + + align:start position:0% +can it be supported as a competitive + + + align:start position:0% +can it be supported as a competitive +equilibrium the answer is no + + align:start position:0% +equilibrium the answer is no + + + align:start position:0% +equilibrium the answer is no +because given this imagine supporting + + align:start position:0% +because given this imagine supporting + + + align:start position:0% +because given this imagine supporting +hyper plane + + align:start position:0% +hyper plane + + + align:start position:0% +hyper plane +the household would be better off moving + + align:start position:0% +the household would be better off moving + + + align:start position:0% +the household would be better off moving +away to some extreme have a higher + + align:start position:0% +away to some extreme have a higher + + + align:start position:0% +away to some extreme have a higher +utility so it's not going to be + + align:start position:0% +utility so it's not going to be + + + align:start position:0% +utility so it's not going to be +consistent with utility maximization and + + align:start position:0% +consistent with utility maximization and + + + align:start position:0% +consistent with utility maximization and +this one is not consistent with profit + + align:start position:0% +this one is not consistent with profit + + + align:start position:0% +this one is not consistent with profit +maximization even though it is still a + + align:start position:0% +maximization even though it is still a + + + align:start position:0% +maximization even though it is still a +pareto optimal point as you could sort + + align:start position:0% +pareto optimal point as you could sort + + + align:start position:0% +pareto optimal point as you could sort +of construct graphically + + align:start position:0% +of construct graphically + + + align:start position:0% +of construct graphically +so i showed you this picture earlier + + align:start position:0% +so i showed you this picture earlier + + + align:start position:0% +so i showed you this picture earlier +this is kind of an aggregated version of + + align:start position:0% +this is kind of an aggregated version of + + + align:start position:0% +this is kind of an aggregated version of +it + + align:start position:0% +it + + + align:start position:0% +it +just says those assumptions are + + align:start position:0% +just says those assumptions are + + + align:start position:0% +just says those assumptions are +sufficient they're not necessarily + + align:start position:0% +sufficient they're not necessarily + + + align:start position:0% +sufficient they're not necessarily +necessary + + align:start position:0% +necessary + + + align:start position:0% +necessary +the first welfare theorem is a + + align:start position:0% +the first welfare theorem is a + + + align:start position:0% +the first welfare theorem is a +competitive equilibrium is optimal this + + align:start position:0% +competitive equilibrium is optimal this + + + align:start position:0% +competitive equilibrium is optimal this +one assumes the existence of a + + align:start position:0% +one assumes the existence of a + + + align:start position:0% +one assumes the existence of a +competitive equilibrium + + align:start position:0% +competitive equilibrium + + + align:start position:0% +competitive equilibrium +all we need is rationality and + + align:start position:0% +all we need is rationality and + + + align:start position:0% +all we need is rationality and +non-satiation but this was a picture + + align:start position:0% +non-satiation but this was a picture + + + align:start position:0% +non-satiation but this was a picture +showing that if we don't have + + align:start position:0% +showing that if we don't have + + + align:start position:0% +showing that if we don't have +non-satiation locally we're not + + align:start position:0% +non-satiation locally we're not + + + align:start position:0% +non-satiation locally we're not +necessarily going to show that the + + align:start position:0% +necessarily going to show that the + + + align:start position:0% +necessarily going to show that the +competitive equilibrium is pareto + + align:start position:0% +competitive equilibrium is pareto + + + align:start position:0% +competitive equilibrium is pareto +optimal + + align:start position:0% +optimal + + + align:start position:0% +optimal +because we're given the competitive + + align:start position:0% +because we're given the competitive + + + align:start position:0% +because we're given the competitive +equilibrium we can find something pareto + + align:start position:0% +equilibrium we can find something pareto + + + align:start position:0% +equilibrium we can find something pareto +dominating + + align:start position:0% +dominating + + + align:start position:0% +dominating +then we went through this pollution + + align:start position:0% +then we went through this pollution + + + align:start position:0% +then we went through this pollution +example + + align:start position:0% +example + + + align:start position:0% +example +which is like not allowing + + align:start position:0% +which is like not allowing + + + align:start position:0% +which is like not allowing +trade in all the goods and again the + + align:start position:0% +trade in all the goods and again the + + + align:start position:0% +trade in all the goods and again the +intuition for this + + align:start position:0% +intuition for this + + + align:start position:0% +intuition for this +this miraculous price system when it + + align:start position:0% +this miraculous price system when it + + + align:start position:0% +this miraculous price system when it +works + + align:start position:0% +works + + + align:start position:0% +works +means that households only have to + + align:start position:0% +means that households only have to + + + align:start position:0% +means that households only have to +evaluate things on the margin at those + + align:start position:0% +evaluate things on the margin at those + + + align:start position:0% +evaluate things on the margin at those +prices they internalize + + align:start position:0% +prices they internalize + + + align:start position:0% +prices they internalize +through the prices + + align:start position:0% +through the prices + + + align:start position:0% +through the prices +and make the right decision the prices + + align:start position:0% +and make the right decision the prices + + + align:start position:0% +and make the right decision the prices +reflect the social trade-off + + align:start position:0% +reflect the social trade-off + + + align:start position:0% +reflect the social trade-off +of increasing or decreasing + + align:start position:0% +of increasing or decreasing + + + align:start position:0% +of increasing or decreasing +demands + + align:start position:0% +demands + + + align:start position:0% +demands +and of course they're much aware of + + align:start position:0% +and of course they're much aware of + + + align:start position:0% +and of course they're much aware of +their utility consequences their + + align:start position:0% +their utility consequences their + + + align:start position:0% +their utility consequences their +marginal rate of substitution + + align:start position:0% +marginal rate of substitution + + + align:start position:0% +marginal rate of substitution +so if we get it right in a competitive + + align:start position:0% +so if we get it right in a competitive + + + align:start position:0% +so if we get it right in a competitive +equilibrium in complete markets and the + + align:start position:0% +equilibrium in complete markets and the + + + align:start position:0% +equilibrium in complete markets and the +price system conveys all the right + + align:start position:0% +price system conveys all the right + + + align:start position:0% +price system conveys all the right +things on the margin and all the people + + align:start position:0% +things on the margin and all the people + + + align:start position:0% +things on the margin and all the people +have to do + + align:start position:0% +have to do + + + align:start position:0% +have to do +is take from god this price system from + + align:start position:0% +is take from god this price system from + + + align:start position:0% +is take from god this price system from +adam smith you might say + + align:start position:0% +adam smith you might say + + + align:start position:0% +adam smith you might say +as if by an invisible hand namely the + + align:start position:0% +as if by an invisible hand namely the + + + align:start position:0% +as if by an invisible hand namely the +price system + + align:start position:0% +price system + + + align:start position:0% +price system +be guided to + + align:start position:0% +be guided to + + + align:start position:0% +be guided to +pareto optimal allocations but likewise + + align:start position:0% +pareto optimal allocations but likewise + + + align:start position:0% +pareto optimal allocations but likewise +if we screw up the markets + + align:start position:0% +if we screw up the markets + + + align:start position:0% +if we screw up the markets +then + + align:start position:0% +then + + + align:start position:0% +then +the whole thing falls apart and this + + align:start position:0% +the whole thing falls apart and this + + + align:start position:0% +the whole thing falls apart and this +pollution example was where we didn't + + align:start position:0% +pollution example was where we didn't + + + align:start position:0% +pollution example was where we didn't +have a price for all the goods so we + + align:start position:0% +have a price for all the goods so we + + + align:start position:0% +have a price for all the goods so we +don't have a rate of substitution of one + + align:start position:0% +don't have a rate of substitution of one + + + align:start position:0% +don't have a rate of substitution of one +good for the other + + align:start position:0% +good for the other + + + align:start position:0% +good for the other +in the market and + + align:start position:0% +in the market and + + + align:start position:0% +in the market and +and households and firms make + + align:start position:0% +and households and firms make + + + align:start position:0% +and households and firms make +inefficient choices so we did that with + + align:start position:0% +inefficient choices so we did that with + + + align:start position:0% +inefficient choices so we did that with +the pollution as a leading example we + + align:start position:0% +the pollution as a leading example we + + + align:start position:0% +the pollution as a leading example we +went to aero to generalize it where + + align:start position:0% +went to aero to generalize it where + + + align:start position:0% +went to aero to generalize it where +households care about others consumption + + align:start position:0% +households care about others consumption + + + align:start position:0% +households care about others consumption +either they're altruistic or envious and + + align:start position:0% +either they're altruistic or envious and + + + align:start position:0% +either they're altruistic or envious and +the same thing kind of works this is the + + align:start position:0% +the same thing kind of works this is the + + + align:start position:0% +the same thing kind of works this is the +fourth or fifth time today that we talk + + align:start position:0% +fourth or fifth time today that we talk + + + align:start position:0% +fourth or fifth time today that we talk +about a pareto problem + + align:start position:0% +about a pareto problem + + + align:start position:0% +about a pareto problem +an associated first order conditions + + align:start position:0% +an associated first order conditions + + + align:start position:0% +an associated first order conditions +generating shadow prices so we're + + align:start position:0% +generating shadow prices so we're + + + align:start position:0% +generating shadow prices so we're +following exactly the same steps as in + + align:start position:0% +following exactly the same steps as in + + + align:start position:0% +following exactly the same steps as in +the second welfare theorem + + align:start position:0% +the second welfare theorem + + + align:start position:0% +the second welfare theorem +and finding a way despite the + + align:start position:0% +and finding a way despite the + + + align:start position:0% +and finding a way despite the +externalities and utility functions to + + align:start position:0% +externalities and utility functions to + + + align:start position:0% +externalities and utility functions to +support the pareto optimal allocation as + + align:start position:0% +support the pareto optimal allocation as + + + align:start position:0% +support the pareto optimal allocation as +a competitive equilibrium + + align:start position:0% +a competitive equilibrium + + + align:start position:0% +a competitive equilibrium +we already talked about failure + + align:start position:0% +we already talked about failure + + + align:start position:0% +we already talked about failure +when we have an infinite number of goods + + align:start position:0% +when we have an infinite number of goods + + + align:start position:0% +when we have an infinite number of goods +this was + + align:start position:0% +this was + + + align:start position:0% +this was +an example of how to pareto dominate an + + align:start position:0% +an example of how to pareto dominate an + + + align:start position:0% +an example of how to pareto dominate an +allocation + + align:start position:0% +allocation + + + align:start position:0% +allocation +by essentially + + align:start position:0% +by essentially + + + align:start position:0% +by essentially +giving + + align:start position:0% +giving + + + align:start position:0% +giving +the first household some goods the + + align:start position:0% +the first household some goods the + + + align:start position:0% +the first household some goods the +second had + + align:start position:0% +second had + + + align:start position:0% +second had +and then the third giving to the second + + align:start position:0% +and then the third giving to the second + + + align:start position:0% +and then the third giving to the second +and so on + + align:start position:0% +and so on + + + align:start position:0% +and so on +this is exactly what's going on in the + + align:start position:0% +this is exactly what's going on in the + + + align:start position:0% +this is exactly what's going on in the +overlapping generations monetary economy + + align:start position:0% +overlapping generations monetary economy + + + align:start position:0% +overlapping generations monetary economy +of lecture 21. money is worthless + + align:start position:0% +of lecture 21. money is worthless + + + align:start position:0% +of lecture 21. money is worthless +it's just pieces of paper there's no + + align:start position:0% +it's just pieces of paper there's no + + + align:start position:0% +it's just pieces of paper there's no +intrinsic value + + align:start position:0% +intrinsic value + + + align:start position:0% +intrinsic value +but if household 2 here came up with + + align:start position:0% +but if household 2 here came up with + + + align:start position:0% +but if household 2 here came up with +money + + align:start position:0% +money + + + align:start position:0% +money +and gave it to household took money + + align:start position:0% +and gave it to household took money + + + align:start position:0% +and gave it to household took money +sorry from household one + + align:start position:0% +sorry from household one + + + align:start position:0% +sorry from household one +and exchange it for goods + + align:start position:0% +and exchange it for goods + + + align:start position:0% +and exchange it for goods +you know then one gets the goods and two + + align:start position:0% +you know then one gets the goods and two + + + align:start position:0% +you know then one gets the goods and two +gets the money + + align:start position:0% +gets the money + + + align:start position:0% +gets the money +and then two can pass the money along to + + align:start position:0% +and then two can pass the money along to + + + align:start position:0% +and then two can pass the money along to +household three + + align:start position:0% +household three + + + align:start position:0% +household three +so there is a connection between this + + align:start position:0% +so there is a connection between this + + + align:start position:0% +so there is a connection between this +artificial example + + align:start position:0% +artificial example + + + align:start position:0% +artificial example +and the fact + + align:start position:0% +and the fact + + + align:start position:0% +and the fact +that we get + + align:start position:0% +that we get + + + align:start position:0% +that we get +a non-optimal autarky equilibrium + + align:start position:0% +a non-optimal autarky equilibrium + + + align:start position:0% +a non-optimal autarky equilibrium +dominated by + + align:start position:0% +dominated by + + + align:start position:0% +dominated by +a monetary equilibrium in the + + align:start position:0% +a monetary equilibrium in the + + + align:start position:0% +a monetary equilibrium in the +overlapping + + align:start position:0% +overlapping + + + align:start position:0% +overlapping +generations model + + align:start position:0% +generations model + + + align:start position:0% +generations model +which we talked about at the beginning + + align:start position:0% +which we talked about at the beginning + + + align:start position:0% +which we talked about at the beginning +of class okay + + align:start position:0% +of class okay + + + align:start position:0% +of class okay +so + + align:start position:0% +so + + + align:start position:0% +so +essentially that was that was it for + + align:start position:0% +essentially that was that was it for + + + align:start position:0% +essentially that was that was it for +lecture 23 + + align:start position:0% +lecture 23 + + + align:start position:0% +lecture 23 +and we already reviewed lecture 21 so + + align:start position:0% +and we already reviewed lecture 21 so + + + align:start position:0% +and we already reviewed lecture 21 so +questions + + align:start position:0% + + + + align:start position:0% + +i enjoy teaching the class i i really + + align:start position:0% +i enjoy teaching the class i i really + + + align:start position:0% +i enjoy teaching the class i i really +enjoy the interaction with you guys + + align:start position:0% +enjoy the interaction with you guys + + + align:start position:0% +enjoy the interaction with you guys +you're + + align:start position:0% +you're + + + align:start position:0% +you're +really doing well + + align:start position:0% +really doing well + + + align:start position:0% +really doing well +it's a great joy to me i hope you like + + align:start position:0% +it's a great joy to me i hope you like + + + align:start position:0% +it's a great joy to me i hope you like +this way of learning economics and + + align:start position:0% +this way of learning economics and + + + align:start position:0% +this way of learning economics and +you're really quite well trained now + + align:start position:0% +you're really quite well trained now + + + align:start position:0% +you're really quite well trained now +thank you very much + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/DzqE7tj7eIM.txt b/DzqE7tj7eIM.txt new file mode 100644 index 0000000000000000000000000000000000000000..427837511d2b364ce47b6b21b33f7dcc69cab4c6 --- /dev/null +++ b/DzqE7tj7eIM.txt @@ -0,0 +1,2531 @@ +align:start position:0% + +okay um so today begins uh igen values + + align:start position:0% +okay um so today begins uh igen values + + + align:start position:0% +okay um so today begins uh igen values +and igen + + align:start position:0% +and igen + + + align:start position:0% +and igen +vectors and the reason we want those + + align:start position:0% +vectors and the reason we want those + + + align:start position:0% +vectors and the reason we want those +need those is to solve systems of linear + + align:start position:0% +need those is to solve systems of linear + + + align:start position:0% +need those is to solve systems of linear +equations systems meaning more than one + + align:start position:0% +equations systems meaning more than one + + + align:start position:0% +equations systems meaning more than one +equation n equations n equal 2 in the + + align:start position:0% +equation n equations n equal 2 in the + + + align:start position:0% +equation n equations n equal 2 in the +examples here so so Lan value is a + + align:start position:0% +examples here so so Lan value is a + + + align:start position:0% +examples here so so Lan value is a +number I Vector is a vector they're both + + align:start position:0% +number I Vector is a vector they're both + + + align:start position:0% +number I Vector is a vector they're both +hiding in the + + align:start position:0% +hiding in the + + + align:start position:0% +hiding in the +Matrix once we find them we can use them + + align:start position:0% +Matrix once we find them we can use them + + + align:start position:0% +Matrix once we find them we can use them +let me show you the reason igen values + + align:start position:0% +let me show you the reason igen values + + + align:start position:0% +let me show you the reason igen values +were created invented discovered uh was + + align:start position:0% +were created invented discovered uh was + + + align:start position:0% +were created invented discovered uh was +solving differential equations which is + + align:start position:0% +solving differential equations which is + + + align:start position:0% +solving differential equations which is +our purpose so Y is now a vector because + + align:start position:0% +our purpose so Y is now a vector because + + + align:start position:0% +our purpose so Y is now a vector because +so this is a system of + + align:start position:0% +so this is a system of + + + align:start position:0% +so this is a system of +equations I'll do an example in a minute + + align:start position:0% +equations I'll do an example in a minute + + + align:start position:0% +equations I'll do an example in a minute +a is a matrix so why so we have n + + align:start position:0% +a is a matrix so why so we have n + + + align:start position:0% +a is a matrix so why so we have n +equations n components of Y and a is an + + align:start position:0% +equations n components of Y and a is an + + + align:start position:0% +equations n components of Y and a is an +N byn Matrix n rows n columns good and + + align:start position:0% +N byn Matrix n rows n columns good and + + + align:start position:0% +N byn Matrix n rows n columns good and +now I can tell you right away where igen + + align:start position:0% +now I can tell you right away where igen + + + align:start position:0% +now I can tell you right away where igen +values and igen vectors pay off they + + align:start position:0% +values and igen vectors pay off they + + + align:start position:0% +values and igen vectors pay off they +they come into the solution we look for + + align:start position:0% +they come into the solution we look for + + + align:start position:0% +they come into the solution we look for +Solutions of that kind when we had one + + align:start position:0% +Solutions of that kind when we had one + + + align:start position:0% +Solutions of that kind when we had one +equation we looked for Solutions just e + + align:start position:0% +equation we looked for Solutions just e + + + align:start position:0% +equation we looked for Solutions just e +to the + + align:start position:0% +to the + + + align:start position:0% +to the +St and we found that number s now we + + align:start position:0% +St and we found that number s now we + + + align:start position:0% +St and we found that number s now we +have e to the Lambda T we changed s to + + align:start position:0% +have e to the Lambda T we changed s to + + + align:start position:0% +have e to the Lambda T we changed s to +Lambda no problem and but multiplied by + + align:start position:0% +Lambda no problem and but multiplied by + + + align:start position:0% +Lambda no problem and but multiplied by +a vector because our unknown is a vector + + align:start position:0% +a vector because our unknown is a vector + + + align:start position:0% +a vector because our unknown is a vector +this is a vector but that does not + + align:start position:0% +this is a vector but that does not + + + align:start position:0% +this is a vector but that does not +depend on time that's the beauty of it + + align:start position:0% +depend on time that's the beauty of it + + + align:start position:0% +depend on time that's the beauty of it +all the time dependence is in the + + align:start position:0% +all the time dependence is in the + + + align:start position:0% +all the time dependence is in the +exponential as always and X is just + + align:start position:0% +exponential as always and X is just + + + align:start position:0% +exponential as always and X is just +multiples of that exponential as you'll + + align:start position:0% +multiples of that exponential as you'll + + + align:start position:0% +multiples of that exponential as you'll +see okay so I look for Solutions like + + align:start position:0% +see okay so I look for Solutions like + + + align:start position:0% +see okay so I look for Solutions like +that I plug that into the differential + + align:start position:0% +that I plug that into the differential + + + align:start position:0% +that I plug that into the differential +equation and what happens so here's my + + align:start position:0% +equation and what happens so here's my + + + align:start position:0% +equation and what happens so here's my +equation I'm plugging in e to the Lambda + + align:start position:0% +equation I'm plugging in e to the Lambda + + + align:start position:0% +equation I'm plugging in e to the Lambda +TX that's y That's a * y there now the + + align:start position:0% +TX that's y That's a * y there now the + + + align:start position:0% +TX that's y That's a * y there now the +derivative of y the time derivative + + align:start position:0% +derivative of y the time derivative + + + align:start position:0% +derivative of y the time derivative +brings down a Lambda so + + align:start position:0% +brings down a Lambda so + + + align:start position:0% +brings down a Lambda so +to get the derivative I include the + + align:start position:0% +to get the derivative I include the + + + align:start position:0% +to get the derivative I include the +Lambda so do you see that substituting + + align:start position:0% +Lambda so do you see that substituting + + + align:start position:0% +Lambda so do you see that substituting +into the equation with this nice + + align:start position:0% +into the equation with this nice + + + align:start position:0% +into the equation with this nice +notation is just this has to be true my + + align:start position:0% +notation is just this has to be true my + + + align:start position:0% +notation is just this has to be true my +equation changed to that form okay now I + + align:start position:0% +equation changed to that form okay now I + + + align:start position:0% +equation changed to that form okay now I +cancel e to the Lambda T just the way I + + align:start position:0% +cancel e to the Lambda T just the way I + + + align:start position:0% +cancel e to the Lambda T just the way I +was always canceling e to the S so I + + align:start position:0% +was always canceling e to the S so I + + + align:start position:0% +was always canceling e to the S so I +cancel e to the Lambda T because it's + + align:start position:0% +cancel e to the Lambda T because it's + + + align:start position:0% +cancel e to the Lambda T because it's +never zero and I have the biggest + + align:start position:0% +never zero and I have the biggest + + + align:start position:0% +never zero and I have the biggest +equation + + align:start position:0% +equation + + + align:start position:0% +equation +ax The Matrix times my I Vector is equal + + align:start position:0% +ax The Matrix times my I Vector is equal + + + align:start position:0% +ax The Matrix times my I Vector is equal +to Lambda X the number the I value times + + align:start position:0% +to Lambda X the number the I value times + + + align:start position:0% +to Lambda X the number the I value times +the igen vector not linear + + align:start position:0% +the igen vector not linear + + + align:start position:0% +the igen vector not linear +notice two unknowns here that are + + align:start position:0% +notice two unknowns here that are + + + align:start position:0% +notice two unknowns here that are +multiplied a number Lambda times a + + align:start position:0% +multiplied a number Lambda times a + + + align:start position:0% +multiplied a number Lambda times a +vector X so what what am I looking for + + align:start position:0% +vector X so what what am I looking for + + + align:start position:0% +vector X so what what am I looking for +I'm looking for vectors + + align:start position:0% +I'm looking for vectors + + + align:start position:0% +I'm looking for vectors +X the igen vectors so that mult + + align:start position:0% +X the igen vectors so that mult + + + align:start position:0% +X the igen vectors so that mult +multiplying by a multiplying a * X gives + + align:start position:0% +multiplying by a multiplying a * X gives + + + align:start position:0% +multiplying by a multiplying a * X gives +a number time x it's in the same + + align:start position:0% +a number time x it's in the same + + + align:start position:0% +a number time x it's in the same +direction as X just the length is + + align:start position:0% +direction as X just the length is + + + align:start position:0% +direction as X just the length is +changed well if Lambda was be was one I + + align:start position:0% +changed well if Lambda was be was one I + + + align:start position:0% +changed well if Lambda was be was one I +would have ax equal x that's allowed if + + align:start position:0% +would have ax equal x that's allowed if + + + align:start position:0% +would have ax equal x that's allowed if +Lambda is zero I would have ax equals z + + align:start position:0% +Lambda is zero I would have ax equals z + + + align:start position:0% +Lambda is zero I would have ax equals z +that's all right I don't want X to be + + align:start position:0% +that's all right I don't want X to be + + + align:start position:0% +that's all right I don't want X to be +zero that's useless that's no that's no + + align:start position:0% +zero that's useless that's no that's no + + + align:start position:0% +zero that's useless that's no that's no +help to know that zero is a solution + + align:start position:0% +help to know that zero is a solution + + + align:start position:0% +help to know that zero is a solution +it's the it's so X should be not zero + + align:start position:0% +it's the it's so X should be not zero + + + align:start position:0% +it's the it's so X should be not zero +Lambda can be any number and it can be + + align:start position:0% +Lambda can be any number and it can be + + + align:start position:0% +Lambda can be any number and it can be +real it could be complex number as you + + align:start position:0% +real it could be complex number as you + + + align:start position:0% +real it could be complex number as you +will see even if the Matrix is real + + align:start position:0% +will see even if the Matrix is real + + + align:start position:0% +will see even if the Matrix is real +Lambda could be complex anyway ax equal + + align:start position:0% +Lambda could be complex anyway ax equal + + + align:start position:0% +Lambda could be complex anyway ax equal +lamb X that's the big equation it got a + + align:start position:0% +lamb X that's the big equation it got a + + + align:start position:0% +lamb X that's the big equation it got a +box around it okay so now I'm ready to + + align:start position:0% +box around it okay so now I'm ready to + + + align:start position:0% +box around it okay so now I'm ready to +do an + + align:start position:0% +do an + + + align:start position:0% +do an +example and in this example first of all + + align:start position:0% +example and in this example first of all + + + align:start position:0% +example and in this example first of all +I'm going to to spot the igen values and + + align:start position:0% +I'm going to to spot the igen values and + + + align:start position:0% +I'm going to to spot the igen values and +IG vectors without a system just go for + + align:start position:0% +IG vectors without a system just go for + + + align:start position:0% +IG vectors without a system just go for +it in the 2x two case okay so I'll give + + align:start position:0% +it in the 2x two case okay so I'll give + + + align:start position:0% +it in the 2x two case okay so I'll give +a 2X two Matrix a we'll find the lambdas + + align:start position:0% +a 2X two Matrix a we'll find the lambdas + + + align:start position:0% +a 2X two Matrix a we'll find the lambdas +and the x's and then we'll have the + + align:start position:0% +and the x's and then we'll have the + + + align:start position:0% +and the x's and then we'll have the +solution to the system of differential + + align:start position:0% +solution to the system of differential + + + align:start position:0% +solution to the system of differential +equations + + align:start position:0% +equations + + + align:start position:0% +equations +good okay there's the + + align:start position:0% +good okay there's the + + + align:start position:0% +good okay there's the +system there's the first equation for y1 + + align:start position:0% +system there's the first equation for y1 + + + align:start position:0% +system there's the first equation for y1 +prime meaning derivative + + align:start position:0% +prime meaning derivative + + + align:start position:0% +prime meaning derivative +time d by DT time derivative is a linear + + align:start position:0% +time d by DT time derivative is a linear + + + align:start position:0% +time d by DT time derivative is a linear +constant coefficients second one linear + + align:start position:0% +constant coefficients second one linear + + + align:start position:0% +constant coefficients second one linear +constant coefficients three and three + + align:start position:0% +constant coefficients three and three + + + align:start position:0% +constant coefficients three and three +those numbers 5 1 3 3 go into the Matrix + + align:start position:0% +those numbers 5 1 3 3 go into the Matrix + + + align:start position:0% +those numbers 5 1 3 3 go into the Matrix +then that problem is exactly y Prime the + + align:start position:0% +then that problem is exactly y Prime the + + + align:start position:0% +then that problem is exactly y Prime the +vector derivative of the vector equal a + + align:start position:0% +vector derivative of the vector equal a + + + align:start position:0% +vector derivative of the vector equal a +* y okay that's my problem now I values + + align:start position:0% +* y okay that's my problem now I values + + + align:start position:0% +* y okay that's my problem now I values +and I vectors will solve it okay so I + + align:start position:0% +and I vectors will solve it okay so I + + + align:start position:0% +and I vectors will solve it okay so I +just look at that matrix it's Matrix + + align:start position:0% +just look at that matrix it's Matrix + + + align:start position:0% +just look at that matrix it's Matrix +question what are the IG values what are + + align:start position:0% +question what are the IG values what are + + + align:start position:0% +question what are the IG values what are +the igen vectors of that Matrix okay and + + align:start position:0% +the igen vectors of that Matrix okay and + + + align:start position:0% +the igen vectors of that Matrix okay and +remember I want I + + align:start position:0% +remember I want I + + + align:start position:0% +remember I want I +want a x = Lambda + + align:start position:0% +want a x = Lambda + + + align:start position:0% +want a x = Lambda +X I've spotted the first igen Vector one + + align:start position:0% +X I've spotted the first igen Vector one + + + align:start position:0% +X I've spotted the first igen Vector one +one we can just check does it Work If I + + align:start position:0% +one we can just check does it Work If I + + + align:start position:0% +one we can just check does it Work If I +multiply a a by that IG Vector 1 one do + + align:start position:0% +multiply a a by that IG Vector 1 one do + + + align:start position:0% +multiply a a by that IG Vector 1 one do +you see what happens when I multiply by + + align:start position:0% +you see what happens when I multiply by + + + align:start position:0% +you see what happens when I multiply by +one that gives me a six that gives me a + + align:start position:0% +one that gives me a six that gives me a + + + align:start position:0% +one that gives me a six that gives me a +six so a * that Vector is + + align:start position:0% +six so a * that Vector is + + + align:start position:0% +six so a * that Vector is +66 and that is 6 * 1 one so there you go + + align:start position:0% +66 and that is 6 * 1 one so there you go + + + align:start position:0% +66 and that is 6 * 1 one so there you go +found the first igen value If I multiply + + align:start position:0% +found the first igen value If I multiply + + + align:start position:0% +found the first igen value If I multiply +a by X I get 6 by X I get the Vector + + align:start position:0% +a by X I get 6 by X I get the Vector + + + align:start position:0% +a by X I get 6 by X I get the Vector +66 now the second one again I've worked + + align:start position:0% +66 now the second one again I've worked + + + align:start position:0% +66 now the second one again I've worked +in advance produce this igen vector and + + align:start position:0% +in advance produce this igen vector and + + + align:start position:0% +in advance produce this igen vector and +I think is 1us 3 so let's multiply by a + + align:start position:0% +I think is 1us 3 so let's multiply by a + + + align:start position:0% +I think is 1us 3 so let's multiply by a +try the second I Vector I should call + + align:start position:0% +try the second I Vector I should call + + + align:start position:0% +try the second I Vector I should call +this first one maybe X1 and Lambda 1 and + + align:start position:0% +this first one maybe X1 and Lambda 1 and + + + align:start position:0% +this first one maybe X1 and Lambda 1 and +I should call this one X2 and Lambda 2 + + align:start position:0% +I should call this one X2 and Lambda 2 + + + align:start position:0% +I should call this one X2 and Lambda 2 +and we can find out what Lambda 2 is if + + align:start position:0% +and we can find out what Lambda 2 is if + + + align:start position:0% +and we can find out what Lambda 2 is if +I know once I find the I vectors of + + align:start position:0% +I know once I find the I vectors of + + + align:start position:0% +I know once I find the I vectors of +course + + align:start position:0% +course + + + align:start position:0% +course +I just do a * X to to recognize the + + align:start position:0% +I just do a * X to to recognize the + + + align:start position:0% +I just do a * X to to recognize the +Lambda the igen value so 51 * this is 5 + + align:start position:0% +Lambda the igen value so 51 * this is 5 + + + align:start position:0% +Lambda the igen value so 51 * this is 5 +- 3 is a two it's a two so I've get so + + align:start position:0% +- 3 is a two it's a two so I've get so + + + align:start position:0% +- 3 is a two it's a two so I've get so +here I got a + + align:start position:0% +here I got a + + + align:start position:0% +here I got a +two and from 3 3 it's 3 - 9 is - 6 + + align:start position:0% +two and from 3 3 it's 3 - 9 is - 6 + + + align:start position:0% +two and from 3 3 it's 3 - 9 is - 6 +that's what I got for + + align:start position:0% +that's what I got for + + + align:start position:0% +that's what I got for +ax there was the X + + align:start position:0% +ax there was the X + + + align:start position:0% +ax there was the X +when I did the multiplication ax came + + align:start position:0% +when I did the multiplication ax came + + + align:start position:0% +when I did the multiplication ax came +out to be 2 - 6 and + + align:start position:0% +out to be 2 - 6 and + + + align:start position:0% +out to be 2 - 6 and +good that output is two times the input + + align:start position:0% +good that output is two times the input + + + align:start position:0% +good that output is two times the input +the I value is + + align:start position:0% +the I value is + + + align:start position:0% +the I value is +two right I'm looking for + + align:start position:0% +two right I'm looking for + + + align:start position:0% +two right I'm looking for +inputs the IG Vector so that the output + + align:start position:0% +inputs the IG Vector so that the output + + + align:start position:0% +inputs the IG Vector so that the output +is a number times that IG vector and + + align:start position:0% +is a number times that IG vector and + + + align:start position:0% +is a number times that IG vector and +that number is Lambda the I value so I + + align:start position:0% +that number is Lambda the I value so I + + + align:start position:0% +that number is Lambda the I value so I +have now found the two and and I expect + + align:start position:0% +have now found the two and and I expect + + + align:start position:0% +have now found the two and and I expect +two for a 2X two Matrix you'll see soon + + align:start position:0% +two for a 2X two Matrix you'll see soon + + + align:start position:0% +two for a 2X two Matrix you'll see soon +see why I expect two igen values and + + align:start position:0% +see why I expect two igen values and + + + align:start position:0% +see why I expect two igen values and +each igen value should have an igen + + align:start position:0% +each igen value should have an igen + + + align:start position:0% +each igen value should have an igen +Vector so uh here they are for this + + align:start position:0% +Vector so uh here they are for this + + + align:start position:0% +Vector so uh here they are for this +Matrix so I've got the answers now y of + + align:start position:0% + + + + align:start position:0% + +T which which stands for y1 and Y2 of t + + align:start position:0% + + + + align:start position:0% + +those + + align:start position:0% +those + + + align:start position:0% +those +are okay it's e to the Lambda TX that's + + align:start position:0% +are okay it's e to the Lambda TX that's + + + align:start position:0% +are okay it's e to the Lambda TX that's +remember that's the picture that we're + + align:start position:0% +remember that's the picture that we're + + + align:start position:0% +remember that's the picture that we're +looking for so the first one is e to the + + align:start position:0% +looking for so the first one is e to the + + + align:start position:0% +looking for so the first one is e to the +6t * X which + + align:start position:0% +6t * X which + + + align:start position:0% +6t * X which +is1 if I put that into the equation it + + align:start position:0% +is1 if I put that into the equation it + + + align:start position:0% +is1 if I put that into the equation it +will solve the equation also have + + align:start position:0% +will solve the equation also have + + + align:start position:0% +will solve the equation also have +another one e to the Lambda 2 was 2 t + + align:start position:0% +another one e to the Lambda 2 was 2 t + + + align:start position:0% +another one e to the Lambda 2 was 2 t +e to the Lambda T * its I Vector 1 - + + align:start position:0% +e to the Lambda T * its I Vector 1 - + + + align:start position:0% +e to the Lambda T * its I Vector 1 - +3 that's a solution also one solution + + align:start position:0% +3 that's a solution also one solution + + + align:start position:0% +3 that's a solution also one solution +another solution and what do I do with + + align:start position:0% +another solution and what do I do with + + + align:start position:0% +another solution and what do I do with +linear equations I take + + align:start position:0% +linear equations I take + + + align:start position:0% +linear equations I take +combinations any number C1 of that plus + + align:start position:0% +combinations any number C1 of that plus + + + align:start position:0% +combinations any number C1 of that plus +any number C2 of that is still a + + align:start position:0% +any number C2 of that is still a + + + align:start position:0% +any number C2 of that is still a +solution that's superposition adding + + align:start position:0% +solution that's superposition adding + + + align:start position:0% +solution that's superposition adding +solutions to linear equations there + + align:start position:0% +solutions to linear equations there + + + align:start position:0% +solutions to linear equations there +these are n equations there's no there's + + align:start position:0% +these are n equations there's no there's + + + align:start position:0% +these are n equations there's no there's +no Force term in these equations I'm not + + align:start position:0% +no Force term in these equations I'm not + + + align:start position:0% +no Force term in these equations I'm not +dealing with a force term I'm looking + + align:start position:0% +dealing with a force term I'm looking + + + align:start position:0% +dealing with a force term I'm looking +for the null Solutions the solutions of + + align:start position:0% +for the null Solutions the solutions of + + + align:start position:0% +for the null Solutions the solutions of +the equations themselves and there I + + align:start position:0% +the equations themselves and there I + + + align:start position:0% +the equations themselves and there I +have two Co two solutions two + + align:start position:0% +have two Co two solutions two + + + align:start position:0% +have two Co two solutions two +coefficients to choose how do I choose + + align:start position:0% +coefficients to choose how do I choose + + + align:start position:0% +coefficients to choose how do I choose +them of course I match the initial + + align:start position:0% +them of course I match the initial + + + align:start position:0% +them of course I match the initial +condition so at T equals z + + align:start position:0% + + + + align:start position:0% + +at tal 0 at t = 0 I would have y of + + align:start position:0% + + + + align:start position:0% + +0 that's my given initial condition my + + align:start position:0% +0 that's my given initial condition my + + + align:start position:0% +0 that's my given initial condition my +y1 and Y2 will be so I'm setting T + + align:start position:0% +y1 and Y2 will be so I'm setting T + + + align:start position:0% +y1 and Y2 will be so I'm setting T +equals z so that's one of course when T + + align:start position:0% +equals z so that's one of course when T + + + align:start position:0% +equals z so that's one of course when T +is zero that's one so I just have C1 * 1 + + align:start position:0% +is zero that's one so I just have C1 * 1 + + + align:start position:0% +is zero that's one so I just have C1 * 1 +1 and C2 * + + align:start position:0% +1 and C2 * + + + align:start position:0% +1 and C2 * +that that's 1 again at t = 0 * 1 - + + align:start position:0% +that that's 1 again at t = 0 * 1 - + + + align:start position:0% +that that's 1 again at t = 0 * 1 - +3 that's what + + align:start position:0% +3 that's what + + + align:start position:0% +3 that's what +determines C1 and C2 C1 and C2 come from + + align:start position:0% +determines C1 and C2 C1 and C2 come from + + + align:start position:0% +determines C1 and C2 C1 and C2 come from +the initial conditions just the way they + + align:start position:0% +the initial conditions just the way they + + + align:start position:0% +the initial conditions just the way they +always + + align:start position:0% +always + + + align:start position:0% +always +did so I'm solving two first order + + align:start position:0% +did so I'm solving two first order + + + align:start position:0% +did so I'm solving two first order +linear constant coefficient equations + + align:start position:0% +linear constant coefficient equations + + + align:start position:0% +linear constant coefficient equations +homogeneous meaning no no Force term and + + align:start position:0% +homogeneous meaning no no Force term and + + + align:start position:0% +homogeneous meaning no no Force term and +uh I I'm looking for I so I get a null + + align:start position:0% +uh I I'm looking for I so I get a null + + + align:start position:0% +uh I I'm looking for I so I get a null +solution with constants to choose and + + align:start position:0% +solution with constants to choose and + + + align:start position:0% +solution with constants to choose and +all as as always those constants come + + align:start position:0% +all as as always those constants come + + + align:start position:0% +all as as always those constants come +from matching the initial conditions so + + align:start position:0% +from matching the initial conditions so + + + align:start position:0% +from matching the initial conditions so +the there the initial condition here is + + align:start position:0% +the there the initial condition here is + + + align:start position:0% +the there the initial condition here is +a + + align:start position:0% +a + + + align:start position:0% +a +vector so if for example y of Z was 2 + + align:start position:0% +vector so if for example y of Z was 2 + + + align:start position:0% +vector so if for example y of Z was 2 +minus 2 then I would want one of those + + align:start position:0% +minus 2 then I would want one of those + + + align:start position:0% +minus 2 then I would want one of those +and one of + + align:start position:0% +and one of + + + align:start position:0% +and one of +those okay that's that's I've used igen + + align:start position:0% +those okay that's that's I've used igen + + + align:start position:0% +those okay that's that's I've used igen +values and igen vectors to solve a + + align:start position:0% +values and igen vectors to solve a + + + align:start position:0% +values and igen vectors to solve a +linear system their first and primary + + align:start position:0% +linear system their first and primary + + + align:start position:0% +linear system their first and primary +purpose okay but how do I find those + + align:start position:0% +purpose okay but how do I find those + + + align:start position:0% +purpose okay but how do I find those +igen values and igen vectors what about + + align:start position:0% +igen values and igen vectors what about + + + align:start position:0% +igen values and igen vectors what about +other properties what what's going on + + align:start position:0% +other properties what what's going on + + + align:start position:0% +other properties what what's going on +with igen values and igen vectors may I + + align:start position:0% +with igen values and igen vectors may I + + + align:start position:0% +with igen values and igen vectors may I +begin on this just a couple more minutes + + align:start position:0% +begin on this just a couple more minutes + + + align:start position:0% +begin on this just a couple more minutes +about IG value Val and ion vectors basic + + align:start position:0% +about IG value Val and ion vectors basic + + + align:start position:0% +about IG value Val and ion vectors basic +facts and then I'll come next time next + + align:start position:0% +facts and then I'll come next time next + + + align:start position:0% +facts and then I'll come next time next +video of how to find them okay basic + + align:start position:0% +video of how to find them okay basic + + + align:start position:0% +video of how to find them okay basic +facts basic facts so + + align:start position:0% +facts basic facts so + + + align:start position:0% +facts basic facts so +start + + align:start position:0% +start + + + align:start position:0% +start +from + + align:start position:0% +from + + + align:start position:0% +from +Ax = Lambda + + align:start position:0% +Ax = Lambda + + + align:start position:0% +Ax = Lambda +X let's suppose we found + + align:start position:0% +X let's suppose we found + + + align:start position:0% +X let's suppose we found +those could you tell me the igen values + + align:start position:0% +those could you tell me the igen values + + + align:start position:0% +those could you tell me the igen values +and igen vectors of a + + align:start position:0% +and igen vectors of a + + + align:start position:0% +and igen vectors of a +squared this is + + align:start position:0% +squared this is + + + align:start position:0% +squared this is +a + + align:start position:0% +a + + + align:start position:0% +a +uh I would like to know what the igon + + align:start position:0% +uh I would like to know what the igon + + + align:start position:0% +uh I would like to know what the igon +values and I vectors of a^ squ are are + + align:start position:0% +values and I vectors of a^ squ are are + + + align:start position:0% +values and I vectors of a^ squ are are +they connected with these so I found the + + align:start position:0% +they connected with these so I found the + + + align:start position:0% +they connected with these so I found the +suppose I know the X and I know the + + align:start position:0% +suppose I know the X and I know the + + + align:start position:0% +suppose I know the X and I know the +Lambda what about for a what about for a + + align:start position:0% +Lambda what about for a what about for a + + + align:start position:0% +Lambda what about for a what about for a +squ well the good thing is that the ion + + align:start position:0% +squ well the good thing is that the ion + + + align:start position:0% +squ well the good thing is that the ion +vectors are the same for a s so let me + + align:start position:0% +vectors are the same for a s so let me + + + align:start position:0% +vectors are the same for a s so let me +show you I I say that same X so I'm this + + align:start position:0% +show you I I say that same X so I'm this + + + align:start position:0% +show you I I say that same X so I'm this +is the + + align:start position:0% +is the + + + align:start position:0% +is the +same X same Vector same ion Vector the + + align:start position:0% +same X same Vector same ion Vector the + + + align:start position:0% +same X same Vector same ion Vector the +igen value would be different of course + + align:start position:0% +igen value would be different of course + + + align:start position:0% +igen value would be different of course +for a^ S but the I Vector is the same + + align:start position:0% +for a^ S but the I Vector is the same + + + align:start position:0% +for a^ S but the I Vector is the same +okay and let's see what happens for a s + + align:start position:0% +okay and let's see what happens for a s + + + align:start position:0% +okay and let's see what happens for a s +so that's a * ax right 1 a and another + + align:start position:0% +so that's a * ax right 1 a and another + + + align:start position:0% +so that's a * ax right 1 a and another +ax but ax is Lambda X + + align:start position:0% +ax but ax is Lambda X + + + align:start position:0% +ax but ax is Lambda X +are you good with that that's just a * + + align:start position:0% +are you good with that that's just a * + + + align:start position:0% +are you good with that that's just a * +ax so that okay now Lambda is a number I + + align:start position:0% +ax so that okay now Lambda is a number I + + + align:start position:0% +ax so that okay now Lambda is a number I +like I like to bring it out front where + + align:start position:0% +like I like to bring it out front where + + + align:start position:0% +like I like to bring it out front where +I can see + + align:start position:0% +I can see + + + align:start position:0% +I can see +it so I I didn't do anything there this + + align:start position:0% +it so I I didn't do anything there this + + + align:start position:0% +it so I I didn't do anything there this +number Lambda was multiplying everything + + align:start position:0% +number Lambda was multiplying everything + + + align:start position:0% +number Lambda was multiplying everything +so put it in front now ax I have again + + align:start position:0% +so put it in front now ax I have again + + + align:start position:0% +so put it in front now ax I have again +the ax that's again the Lambda X because + + align:start position:0% +the ax that's again the Lambda X because + + + align:start position:0% +the ax that's again the Lambda X because +I'm looking at this same X same X so I + + align:start position:0% +I'm looking at this same X same X so I + + + align:start position:0% +I'm looking at this same X same X so I +get the same Lambda so that's a Lambda X + + align:start position:0% +get the same Lambda so that's a Lambda X + + + align:start position:0% +get the same Lambda so that's a Lambda X +another Lambda I have Lambda 2 + + align:start position:0% +another Lambda I have Lambda 2 + + + align:start position:0% +another Lambda I have Lambda 2 +x that's what I wanted a^ 2 x is Lambda + + align:start position:0% +x that's what I wanted a^ 2 x is Lambda + + + align:start position:0% +x that's what I wanted a^ 2 x is Lambda +2 x conclusion the I vectors stay the + + align:start position:0% +2 x conclusion the I vectors stay the + + + align:start position:0% +2 x conclusion the I vectors stay the +same + + align:start position:0% +same + + + align:start position:0% +same +Lambda goes to Lambda + + align:start position:0% +Lambda goes to Lambda + + + align:start position:0% +Lambda goes to Lambda +squared the the I values are squared so + + align:start position:0% +squared the the I values are squared so + + + align:start position:0% +squared the the I values are squared so +if I had my example again of oh let me + + align:start position:0% +if I had my example again of oh let me + + + align:start position:0% +if I had my example again of oh let me +find that + + align:start position:0% + + + + align:start position:0% + +Matrix suppose I wanted suppose I had + + align:start position:0% +Matrix suppose I wanted suppose I had + + + align:start position:0% +Matrix suppose I wanted suppose I had +that same + + align:start position:0% +that same + + + align:start position:0% +that same +Matrix and I was interested in a squar + + align:start position:0% +Matrix and I was interested in a squar + + + align:start position:0% +Matrix and I was interested in a squar +then the igen values would be + + align:start position:0% +then the igen values would be + + + align:start position:0% +then the igen values would be +36 and four the + + align:start position:0% +36 and four the + + + align:start position:0% +36 and four the +squares suppose I'm looking at the N + + align:start position:0% +squares suppose I'm looking at the N + + + align:start position:0% +squares suppose I'm looking at the N +power of a matrix you may say why look + + align:start position:0% +power of a matrix you may say why look + + + align:start position:0% +power of a matrix you may say why look +at the N power but there are many + + align:start position:0% +at the N power but there are many + + + align:start position:0% +at the N power but there are many +examples to look at the N power of a + + align:start position:0% +examples to look at the N power of a + + + align:start position:0% +examples to look at the N power of a +matrix mat the thousandth power so let's + + align:start position:0% +matrix mat the thousandth power so let's + + + align:start position:0% +matrix mat the thousandth power so let's +just write down the conclusion same + + align:start position:0% +just write down the conclusion same + + + align:start position:0% +just write down the conclusion same +same uh reasoning a to the n x + + align:start position:0% +same uh reasoning a to the n x + + + align:start position:0% +same uh reasoning a to the n x +is Lambda is the same X and every time I + + align:start position:0% +is Lambda is the same X and every time I + + + align:start position:0% +is Lambda is the same X and every time I +multiply by a I multiply by a Lambda so + + align:start position:0% +multiply by a I multiply by a Lambda so + + + align:start position:0% +multiply by a I multiply by a Lambda so +I get Lambda n + + align:start position:0% + + + + align:start position:0% + +times so there's the handy rule + + align:start position:0% + + + + align:start position:0% + +that really tells us something about + + align:start position:0% +that really tells us something about + + + align:start position:0% +that really tells us something about +what what igen values are good for igen + + align:start position:0% +what what igen values are good for igen + + + align:start position:0% +what what igen values are good for igen +values are good for things that move in + + align:start position:0% +values are good for things that move in + + + align:start position:0% +values are good for things that move in +time e differential + + align:start position:0% +time e differential + + + align:start position:0% +time e differential +equations uh that that is really moving + + align:start position:0% +equations uh that that is really moving + + + align:start position:0% +equations uh that that is really moving +in time n equal 1 is the first first + + align:start position:0% +in time n equal 1 is the first first + + + align:start position:0% +in time n equal 1 is the first first +time or n equals z is the start take one + + align:start position:0% +time or n equals z is the start take one + + + align:start position:0% +time or n equals z is the start take one +step to n equal 1 take another step to n + + align:start position:0% +step to n equal 1 take another step to n + + + align:start position:0% +step to n equal 1 take another step to n +equal 2 keep going every time step + + align:start position:0% +equal 2 keep going every time step + + + align:start position:0% +equal 2 keep going every time step +brings a multiplication by Lambda so + + align:start position:0% +brings a multiplication by Lambda so + + + align:start position:0% +brings a multiplication by Lambda so +that is uh a very useful rule another + + align:start position:0% +that is uh a very useful rule another + + + align:start position:0% +that is uh a very useful rule another +handy rule is what about a plus the + + align:start position:0% + + + + align:start position:0% + +identity suppose I add the identity + + align:start position:0% +identity suppose I add the identity + + + align:start position:0% +identity suppose I add the identity +Matrix to + + align:start position:0% +Matrix to + + + align:start position:0% +Matrix to +my uh to my original Matrix what happens + + align:start position:0% +my uh to my original Matrix what happens + + + align:start position:0% +my uh to my original Matrix what happens +to the igen values what happens to the + + align:start position:0% +to the igen values what happens to the + + + align:start position:0% +to the igen values what happens to the +igen vectors basic question or I could + + align:start position:0% +igen vectors basic question or I could + + + align:start position:0% +igen vectors basic question or I could +multiply a constant times the identity + + align:start position:0% +multiply a constant times the identity + + + align:start position:0% +multiply a constant times the identity +two times the identity seven times the + + align:start position:0% +two times the identity seven times the + + + align:start position:0% +two times the identity seven times the +identity and I want to know what about + + align:start position:0% +identity and I want to know what about + + + align:start position:0% +identity and I want to know what about +its ion vectors and the answer is same + + align:start position:0% +its ion vectors and the answer is same + + + align:start position:0% +its ion vectors and the answer is same +same + + align:start position:0% +same + + + align:start position:0% +same +X's same + + align:start position:0% +X's same + + + align:start position:0% +X's same +x i I show that by figuring out what I + + align:start position:0% +x i I show that by figuring out what I + + + align:start position:0% +x i I show that by figuring out what I +have here this is ax which is Lambda X + + align:start position:0% +have here this is ax which is Lambda X + + + align:start position:0% +have here this is ax which is Lambda X +and this is C * the identity time x the + + align:start position:0% +and this is C * the identity time x the + + + align:start position:0% +and this is C * the identity time x the +identity doesn't do anything so that's + + align:start position:0% +identity doesn't do anything so that's + + + align:start position:0% +identity doesn't do anything so that's +just + + align:start position:0% +just + + + align:start position:0% +just +CX so what do I have + + align:start position:0% +CX so what do I have + + + align:start position:0% +CX so what do I have +now I've seen that the IG value is + + align:start position:0% +now I've seen that the IG value is + + + align:start position:0% +now I've seen that the IG value is +Lambda + + + align:start position:0% +Lambda + + + + align:start position:0% +Lambda + +C so there is the I + + align:start position:0% +C so there is the I + + + align:start position:0% +C so there is the I +values + + align:start position:0% +values + + + align:start position:0% +values +for when I I think about this as + + align:start position:0% +for when I I think about this as + + + align:start position:0% +for when I I think about this as +shifting a by a multi of the identity + + align:start position:0% +shifting a by a multi of the identity + + + align:start position:0% +shifting a by a multi of the identity +shifting a adding adding five times the + + align:start position:0% +shifting a adding adding five times the + + + align:start position:0% +shifting a adding adding five times the +identity to it if I add five five times + + align:start position:0% +identity to it if I add five five times + + + align:start position:0% +identity to it if I add five five times +the identity to any Matrix the igen + + align:start position:0% +the identity to any Matrix the igen + + + align:start position:0% +the identity to any Matrix the igen +values of that Matrix go up by + + align:start position:0% +values of that Matrix go up by + + + align:start position:0% +values of that Matrix go up by +five and the igen vectors stay the same + + align:start position:0% +five and the igen vectors stay the same + + + align:start position:0% +five and the igen vectors stay the same +so for as long as I keep working with + + align:start position:0% +so for as long as I keep working with + + + align:start position:0% +so for as long as I keep working with +that one Matrix a taking Powers taking + + align:start position:0% +that one Matrix a taking Powers taking + + + align:start position:0% +that one Matrix a taking Powers taking +adding adding multiples of the identity + + align:start position:0% +adding adding multiples of the identity + + + align:start position:0% +adding adding multiples of the identity +in the later taking expon exponentials + + align:start position:0% +in the later taking expon exponentials + + + align:start position:0% +in the later taking expon exponentials +whatever I do I keep the same igen + + align:start position:0% +whatever I do I keep the same igen + + + align:start position:0% +whatever I do I keep the same igen +vectors and everything is easy the a + + align:start position:0% +vectors and everything is easy the a + + + align:start position:0% +vectors and everything is easy the a +diff but don't think if I had two two + + align:start position:0% +diff but don't think if I had two two + + + align:start position:0% +diff but don't think if I had two two +matrices A and B with different igen + + align:start position:0% +matrices A and B with different igen + + + align:start position:0% +matrices A and B with different igen +vectors then I don't know what the igen + + align:start position:0% +vectors then I don't know what the igen + + + align:start position:0% +vectors then I don't know what the igen +vectors of a plus b would be I don't + + align:start position:0% +vectors of a plus b would be I don't + + + align:start position:0% +vectors of a plus b would be I don't +know those I can't tell the I vectors of + + align:start position:0% +know those I can't tell the I vectors of + + + align:start position:0% +know those I can't tell the I vectors of +a * B because a has has its own little + + align:start position:0% +a * B because a has has its own little + + + align:start position:0% +a * B because a has has its own little +igen vectors and B has its igen vectors + + align:start position:0% +igen vectors and B has its igen vectors + + + align:start position:0% +igen vectors and B has its igen vectors +and unless they're the same I can't + + align:start position:0% +and unless they're the same I can't + + + align:start position:0% +and unless they're the same I can't +easily combine A and B but these are the + + align:start position:0% +easily combine A and B but these are the + + + align:start position:0% +easily combine A and B but these are the +this shows what I as long as I'm staying + + align:start position:0% +this shows what I as long as I'm staying + + + align:start position:0% +this shows what I as long as I'm staying +with one a and it's powers + + align:start position:0% +with one a and it's powers + + + align:start position:0% +with one a and it's powers +and steps like that no problem okay I'll + + align:start position:0% +and steps like that no problem okay I'll + + + align:start position:0% +and steps like that no problem okay I'll +stop there for a first look at igen + + align:start position:0% +stop there for a first look at igen + + + align:start position:0% +stop there for a first look at igen +values and igen vectors \ No newline at end of file diff --git a/FEK07tdpX3I.txt b/FEK07tdpX3I.txt new file mode 100644 index 0000000000000000000000000000000000000000..bceaef16fb87435adb65d9b6a95719729c664718 --- /dev/null +++ b/FEK07tdpX3I.txt @@ -0,0 +1,475 @@ +align:start position:0% + +welcome back to 8701 + + align:start position:0% +welcome back to 8701 + + + align:start position:0% +welcome back to 8701 +in this short section we want to look at + + align:start position:0% +in this short section we want to look at + + + align:start position:0% +in this short section we want to look at +the weak interaction a little bit more + + align:start position:0% +the weak interaction a little bit more + + + align:start position:0% +the weak interaction a little bit more +and specifically discuss neutral + + align:start position:0% +and specifically discuss neutral + + + align:start position:0% +and specifically discuss neutral +currents we looked + + align:start position:0% +currents we looked + + + align:start position:0% +currents we looked +in some detail charge currents + + align:start position:0% +in some detail charge currents + + + align:start position:0% +in some detail charge currents +specifically the interaction with quarks + + align:start position:0% +specifically the interaction with quarks + + + align:start position:0% +specifically the interaction with quarks +so here + + align:start position:0% +so here + + + align:start position:0% +so here +we want to look at the z border + + align:start position:0% +we want to look at the z border + + + align:start position:0% +we want to look at the z border +specifically in the weak interaction + + align:start position:0% +specifically in the weak interaction + + + align:start position:0% +specifically in the weak interaction +via the neutral current + + align:start position:0% +via the neutral current + + + align:start position:0% +via the neutral current +so studying those two processes here + + align:start position:0% +so studying those two processes here + + + align:start position:0% +so studying those two processes here +where there's an electron in the + + align:start position:0% +where there's an electron in the + + + align:start position:0% +where there's an electron in the +positron + + align:start position:0% +positron + + + align:start position:0% +positron +through some process including a z-boson + + align:start position:0% +through some process including a z-boson + + + align:start position:0% +through some process including a z-boson +or a photon + + align:start position:0% +or a photon + + + align:start position:0% +or a photon +resulting in a muon and an antimurr + + align:start position:0% +resulting in a muon and an antimurr + + + align:start position:0% +resulting in a muon and an antimurr +those processes have been studied in + + align:start position:0% +those processes have been studied in + + + align:start position:0% +those processes have been studied in +great detail at slack + + align:start position:0% +great detail at slack + + + align:start position:0% +great detail at slack +and at cern with the slc and the large + + align:start position:0% +and at cern with the slc and the large + + + align:start position:0% +and at cern with the slc and the large +electron position collider + + align:start position:0% +electron position collider + + + align:start position:0% +electron position collider +so if we want to you know calculate the + + align:start position:0% +so if we want to you know calculate the + + + align:start position:0% +so if we want to you know calculate the +cross section and + + align:start position:0% +cross section and + + + align:start position:0% +cross section and +study the cross section of the center of + + align:start position:0% +study the cross section of the center of + + + align:start position:0% +study the cross section of the center of +mass energy + + align:start position:0% +mass energy + + + align:start position:0% +mass energy +we see a number of interesting effects + + align:start position:0% +we see a number of interesting effects + + + align:start position:0% +we see a number of interesting effects +at low energies and at very large + + align:start position:0% +at low energies and at very large + + + align:start position:0% +at low energies and at very large +energies + + align:start position:0% +energies + + + align:start position:0% +energies +the cross section runs with one over the + + align:start position:0% +the cross section runs with one over the + + + align:start position:0% +the cross section runs with one over the +energy squared + + align:start position:0% +energy squared + + + align:start position:0% +energy squared +but at the mass of the z-border we see + + align:start position:0% +but at the mass of the z-border we see + + + align:start position:0% +but at the mass of the z-border we see +this enormous resonance here so the + + align:start position:0% +this enormous resonance here so the + + + align:start position:0% +this enormous resonance here so the +resonance is about 200 + + align:start position:0% +resonance is about 200 + + + align:start position:0% +resonance is about 200 +the cross-section at the resonance from + + align:start position:0% +the cross-section at the resonance from + + + align:start position:0% +the cross-section at the resonance from +the z-border is about 200 times that of + + align:start position:0% +the z-border is about 200 times that of + + + align:start position:0% +the z-border is about 200 times that of +just the photon exchange so this allows + + align:start position:0% +just the photon exchange so this allows + + + align:start position:0% +just the photon exchange so this allows +you to study the z-boson + + align:start position:0% +you to study the z-boson + + + align:start position:0% +you to study the z-boson +with great precision um at those + + align:start position:0% +with great precision um at those + + + align:start position:0% +with great precision um at those +colliders you have + + align:start position:0% +colliders you have + + + align:start position:0% +colliders you have +sizable cross-section when you're on + + align:start position:0% +sizable cross-section when you're on + + + align:start position:0% +sizable cross-section when you're on +electron position colliders + + align:start position:0% +electron position colliders + + + align:start position:0% +electron position colliders +and then you can with precision look at + + align:start position:0% +and then you can with precision look at + + + align:start position:0% +and then you can with precision look at +you know what is the rate into + + align:start position:0% +you know what is the rate into + + + align:start position:0% +you know what is the rate into +an antivirus what is the rate in the + + align:start position:0% +an antivirus what is the rate in the + + + align:start position:0% +an antivirus what is the rate in the +quark antiqua and so on and you can + + align:start position:0% +quark antiqua and so on and you can + + + align:start position:0% +quark antiqua and so on and you can +study the mass the width of the z + + align:start position:0% +study the mass the width of the z + + + align:start position:0% +study the mass the width of the z +both on um with with an enormous + + align:start position:0% +both on um with with an enormous + + + align:start position:0% +both on um with with an enormous +level of precision again so i will not + + align:start position:0% +level of precision again so i will not + + + align:start position:0% +level of precision again so i will not +go into too much detail here um please + + align:start position:0% +go into too much detail here um please + + + align:start position:0% +go into too much detail here um please +have a look at chapter + + align:start position:0% +have a look at chapter + + + align:start position:0% +have a look at chapter +9.6 in griffiths for example but there's + + align:start position:0% +9.6 in griffiths for example but there's + + + align:start position:0% +9.6 in griffiths for example but there's +many other resources where you can learn + + align:start position:0% +many other resources where you can learn + + + align:start position:0% +many other resources where you can learn +about + + align:start position:0% +about + + + align:start position:0% +about +more about neutral currents neutral + + align:start position:0% +more about neutral currents neutral + + + align:start position:0% +more about neutral currents neutral +currents + + align:start position:0% +currents + + + align:start position:0% +currents +electro weak neutral currents are + + align:start position:0% +electro weak neutral currents are + + + align:start position:0% +electro weak neutral currents are +specifically important in the study of + + align:start position:0% +specifically important in the study of + + + align:start position:0% +specifically important in the study of +neutrinos + + align:start position:0% +neutrinos + + + align:start position:0% +neutrinos +as we have as we will discuss more in + + align:start position:0% +as we have as we will discuss more in + + + align:start position:0% +as we have as we will discuss more in +the lectures as well \ No newline at end of file diff --git a/Fxy3tsWDcpY.txt b/Fxy3tsWDcpY.txt new file mode 100644 index 0000000000000000000000000000000000000000..40b9b9b25153d50a7a4a793902af9ee8886eabb6 --- /dev/null +++ b/Fxy3tsWDcpY.txt @@ -0,0 +1,15123 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu well let's get + + align:start position:0% +ocw.mit.edu well let's get + + + align:start position:0% +ocw.mit.edu well let's get +started I'd like to introduce Lewis + + align:start position:0% +started I'd like to introduce Lewis + + + align:start position:0% +started I'd like to introduce Lewis +Watts it's a great pleasure to have him + + align:start position:0% +Watts it's a great pleasure to have him + + + align:start position:0% +Watts it's a great pleasure to have him +here Lewis is a professor um at the + + align:start position:0% +here Lewis is a professor um at the + + + align:start position:0% +here Lewis is a professor um at the +University of California Santa Cruz + + align:start position:0% +University of California Santa Cruz + + + align:start position:0% +University of California Santa Cruz +he + + align:start position:0% +he + + + align:start position:0% +he +actually has an architectural degree we + + align:start position:0% +actually has an architectural degree we + + + align:start position:0% +actually has an architectural degree we +started studying architecture in + + align:start position:0% +started studying architecture in + + + align:start position:0% +started studying architecture in +graduate school and then drifted towards + + align:start position:0% +graduate school and then drifted towards + + + align:start position:0% +graduate school and then drifted towards +photography his undergraduate degree + + align:start position:0% +photography his undergraduate degree + + + align:start position:0% +photography his undergraduate degree +from Berkeley is in political science + + align:start position:0% +from Berkeley is in political science + + + align:start position:0% +from Berkeley is in political science +and so he came to photography uh after + + align:start position:0% +and so he came to photography uh after + + + align:start position:0% +and so he came to photography uh after +um an undergraduate career in the + + align:start position:0% +um an undergraduate career in the + + + align:start position:0% +um an undergraduate career in the +liberal arts and Lou taught for many + + align:start position:0% +liberal arts and Lou taught for many + + + align:start position:0% +liberal arts and Lou taught for many +years at Berkeley a photography course + + align:start position:0% +years at Berkeley a photography course + + + align:start position:0% +years at Berkeley a photography course +that before I met him I had heard about + + align:start position:0% +that before I met him I had heard about + + + align:start position:0% +that before I met him I had heard about +it from my Berkeley colleagues it was + + align:start position:0% +it from my Berkeley colleagues it was + + + align:start position:0% +it from my Berkeley colleagues it was +known for all the landscape architecture + + align:start position:0% +known for all the landscape architecture + + + align:start position:0% +known for all the landscape architecture +and architecture and planning students + + align:start position:0% +and architecture and planning students + + + align:start position:0% +and architecture and planning students +that that took it um and used + + align:start position:0% +that that took it um and used + + + align:start position:0% +that that took it um and used +photography as a way with L of + + align:start position:0% +photography as a way with L of + + + align:start position:0% +photography as a way with L of +investigating their own culture and and + + align:start position:0% +investigating their own culture and and + + + align:start position:0% +investigating their own culture and and +other cultures and the way they were + + align:start position:0% +other cultures and the way they were + + + align:start position:0% +other cultures and the way they were +expressed in urban + + align:start position:0% +expressed in urban + + + align:start position:0% +expressed in urban +form Lou is uh has had a a distinguished + + align:start position:0% +form Lou is uh has had a a distinguished + + + align:start position:0% +form Lou is uh has had a a distinguished +career he's had many solo exhibitions of + + align:start position:0% +career he's had many solo exhibitions of + + + align:start position:0% +career he's had many solo exhibitions of +his photographs uh been in many many + + align:start position:0% +his photographs uh been in many many + + + align:start position:0% +his photographs uh been in many many +group exhibition positions uh all over + + align:start position:0% +group exhibition positions uh all over + + + align:start position:0% +group exhibition positions uh all over +including the Smithsonian his uh his + + align:start position:0% +including the Smithsonian his uh his + + + align:start position:0% +including the Smithsonian his uh his +work is in the collection of the + + align:start position:0% +work is in the collection of the + + + align:start position:0% +work is in the collection of the +Smithsonian and uh San Francisco uh the + + align:start position:0% +Smithsonian and uh San Francisco uh the + + + align:start position:0% +Smithsonian and uh San Francisco uh the +Museum of Modern Art in San Francisco + + align:start position:0% +Museum of Modern Art in San Francisco + + + align:start position:0% +Museum of Modern Art in San Francisco +he's also as for a photographer done a + + align:start position:0% +he's also as for a photographer done a + + + align:start position:0% +he's also as for a photographer done a +number of in unusual things um including + + align:start position:0% +number of in unusual things um including + + + align:start position:0% +number of in unusual things um including +uh working with the National Park + + align:start position:0% +uh working with the National Park + + + align:start position:0% +uh working with the National Park +Service on and planners on a Heritage + + align:start position:0% +Service on and planners on a Heritage + + + align:start position:0% +Service on and planners on a Heritage +Trail in Richmond California documenting + + align:start position:0% +Trail in Richmond California documenting + + + align:start position:0% +Trail in Richmond California documenting +um the area where the shipyards were + + align:start position:0% +um the area where the shipyards were + + + align:start position:0% +um the area where the shipyards were +during the second world war and he's + + align:start position:0% +during the second world war and he's + + + align:start position:0% +during the second world war and he's +recently just published a book on um the + + align:start position:0% +recently just published a book on um the + + + align:start position:0% +recently just published a book on um the +San Francisco Filmore which I think + + align:start position:0% +San Francisco Filmore which I think + + + align:start position:0% +San Francisco Filmore which I think +he'll tell you a little bit about the + + align:start position:0% +he'll tell you a little bit about the + + + align:start position:0% +he'll tell you a little bit about the +culture of jazz uh in San Francisco it + + align:start position:0% +culture of jazz uh in San Francisco it + + + align:start position:0% +culture of jazz uh in San Francisco it +gives me a great pleasure to um to have + + align:start position:0% +gives me a great pleasure to um to have + + + align:start position:0% +gives me a great pleasure to um to have +Lewis here and I won't say anymore uh uh + + align:start position:0% +Lewis here and I won't say anymore uh uh + + + align:start position:0% +Lewis here and I won't say anymore uh uh +he really needs no more introduction at + + align:start position:0% +he really needs no more introduction at + + + align:start position:0% +he really needs no more introduction at +all thank welcome well thank you + + align:start position:0% + + + + align:start position:0% + +well let's see I'm um I actually went to + + align:start position:0% +well let's see I'm um I actually went to + + + align:start position:0% +well let's see I'm um I actually went to +high school in Boston some 40 years ago + + align:start position:0% +high school in Boston some 40 years ago + + + align:start position:0% +high school in Boston some 40 years ago +and I for some reason I've only been + + align:start position:0% +and I for some reason I've only been + + + align:start position:0% +and I for some reason I've only been +back a few times so it's interesting to + + align:start position:0% +back a few times so it's interesting to + + + align:start position:0% +back a few times so it's interesting to +be here and it sort of brings up some + + align:start position:0% +be here and it sort of brings up some + + + align:start position:0% +be here and it sort of brings up some +things from my past um um a lot of my + + align:start position:0% +things from my past um um a lot of my + + + align:start position:0% +things from my past um um a lot of my +work is informed by um I think migration + + align:start position:0% +work is informed by um I think migration + + + align:start position:0% +work is informed by um I think migration +um my fa my father both of my parents + + align:start position:0% +um my fa my father both of my parents + + + align:start position:0% +um my fa my father both of my parents +are from the south uh my father's from + + align:start position:0% +are from the south uh my father's from + + + align:start position:0% +are from the south uh my father's from +Georg Georgia my mother's from uh + + align:start position:0% +Georg Georgia my mother's from uh + + + align:start position:0% +Georg Georgia my mother's from uh +Arkansas and I was actually born in + + align:start position:0% +Arkansas and I was actually born in + + + align:start position:0% +Arkansas and I was actually born in +Little Rock Arkansas but I was conceived + + align:start position:0% +Little Rock Arkansas but I was conceived + + + align:start position:0% +Little Rock Arkansas but I was conceived +in Seattle because my father was + + align:start position:0% +in Seattle because my father was + + + align:start position:0% +in Seattle because my father was +discharged from Fort Lewis in Tacoma and + + align:start position:0% +discharged from Fort Lewis in Tacoma and + + + align:start position:0% +discharged from Fort Lewis in Tacoma and +went into Seattle and um ended up + + align:start position:0% +went into Seattle and um ended up + + + align:start position:0% +went into Seattle and um ended up +getting a job with the Urban League and + + align:start position:0% +getting a job with the Urban League and + + + align:start position:0% +getting a job with the Urban League and +my mother came to join him and then went + + align:start position:0% +my mother came to join him and then went + + + align:start position:0% +my mother came to join him and then went +back to Little Rock because she knew the + + align:start position:0% +back to Little Rock because she knew the + + + align:start position:0% +back to Little Rock because she knew the +doctor so it's been helpful when I'm + + align:start position:0% +doctor so it's been helpful when I'm + + + align:start position:0% +doctor so it's been helpful when I'm +photographing in the South I can say I + + align:start position:0% +photographing in the South I can say I + + + align:start position:0% +photographing in the South I can say I +I'm I'm from here even though I just was + + align:start position:0% +I'm I'm from here even though I just was + + + align:start position:0% +I'm I'm from here even though I just was +there for four months um so a lot of my + + align:start position:0% +there for four months um so a lot of my + + + align:start position:0% +there for four months um so a lot of my +work um actually so photography caught + + align:start position:0% +work um actually so photography caught + + + align:start position:0% +work um actually so photography caught +me when I was a in the first year of a + + align:start position:0% +me when I was a in the first year of a + + + align:start position:0% +me when I was a in the first year of a +um graduate program for non- Majors uh + + align:start position:0% +um graduate program for non- Majors uh + + + align:start position:0% +um graduate program for non- Majors uh +in architecture at Berkeley and I um + + align:start position:0% +in architecture at Berkeley and I um + + + align:start position:0% +in architecture at Berkeley and I um +ended up actually getting degree in + + align:start position:0% +ended up actually getting degree in + + + align:start position:0% +ended up actually getting degree in +design rather than a master of + + align:start position:0% +design rather than a master of + + + align:start position:0% +design rather than a master of +architecture um and have had had the + + align:start position:0% +architecture um and have had had the + + + align:start position:0% +architecture um and have had had the +opportunity to to teach uh primarily um + + align:start position:0% +opportunity to to teach uh primarily um + + + align:start position:0% +opportunity to to teach uh primarily um +uh seniors and graduate students in the + + align:start position:0% +uh seniors and graduate students in the + + + align:start position:0% +uh seniors and graduate students in the +College of environmental design and a + + align:start position:0% +College of environmental design and a + + + align:start position:0% +College of environmental design and a +few others Berkeley does not really have + + align:start position:0% +few others Berkeley does not really have + + + align:start position:0% +few others Berkeley does not really have +a photo program um but it was + + align:start position:0% +a photo program um but it was + + + align:start position:0% +a photo program um but it was +interesting to me that um uh a most of + + align:start position:0% +interesting to me that um uh a most of + + + align:start position:0% +interesting to me that um uh a most of +the Architects did not want to do do + + align:start position:0% +the Architects did not want to do do + + + align:start position:0% +the Architects did not want to do do +architectural Photography they were + + align:start position:0% +architectural Photography they were + + + align:start position:0% +architectural Photography they were +interested in sort of uh expand uh + + align:start position:0% +interested in sort of uh expand uh + + + align:start position:0% +interested in sort of uh expand uh +exploring the medium kind of another + + align:start position:0% +exploring the medium kind of another + + + align:start position:0% +exploring the medium kind of another +ways and then they would use it in their + + align:start position:0% +ways and then they would use it in their + + + align:start position:0% +ways and then they would use it in their +research later but in the class they + + align:start position:0% +research later but in the class they + + + align:start position:0% +research later but in the class they +wanted I basically taught it as a fine + + align:start position:0% +wanted I basically taught it as a fine + + + align:start position:0% +wanted I basically taught it as a fine +arts class um and my own work um I was + + align:start position:0% +arts class um and my own work um I was + + + align:start position:0% +arts class um and my own work um I was +very interested in photographing in West + + align:start position:0% +very interested in photographing in West + + + align:start position:0% +very interested in photographing in West +Oakland which is um an area that was + + align:start position:0% +Oakland which is um an area that was + + + align:start position:0% +Oakland which is um an area that was +populated during World War II by a lot + + align:start position:0% +populated during World War II by a lot + + + align:start position:0% +populated during World War II by a lot +of + + align:start position:0% +of + + + align:start position:0% +of +African-Americans um who came to work in + + align:start position:0% +African-Americans um who came to work in + + + align:start position:0% +African-Americans um who came to work in +the shipyards uh during World War II + + align:start position:0% +the shipyards uh during World War II + + + align:start position:0% +the shipyards uh during World War II +basically World War II most of you know + + align:start position:0% +basically World War II most of you know + + + align:start position:0% +basically World War II most of you know +into the depression and all of a sudden + + align:start position:0% +into the depression and all of a sudden + + + align:start position:0% +into the depression and all of a sudden +there was work when the war effort began + + align:start position:0% +there was work when the war effort began + + + align:start position:0% +there was work when the war effort began +and what I noticed in West Oakland where + + align:start position:0% +and what I noticed in West Oakland where + + + align:start position:0% +and what I noticed in West Oakland where +there all these sort of evidences of the + + align:start position:0% +there all these sort of evidences of the + + + align:start position:0% +there all these sort of evidences of the +Southern background of either the + + align:start position:0% +Southern background of either the + + + align:start position:0% +Southern background of either the +inhabitants or the parents of the + + align:start position:0% +inhabitants or the parents of the + + + align:start position:0% +inhabitants or the parents of the +inhabitants and how those traces were + + align:start position:0% +inhabitants and how those traces were + + + align:start position:0% +inhabitants and how those traces were +left in the landscape and that's what I + + align:start position:0% +left in the landscape and that's what I + + + align:start position:0% +left in the landscape and that's what I +was interested in photographing I'm the + + align:start position:0% +was interested in photographing I'm the + + + align:start position:0% +was interested in photographing I'm the +son of um two social scientists and it's + + align:start position:0% +son of um two social scientists and it's + + + align:start position:0% +son of um two social scientists and it's +funny when I first started doing + + align:start position:0% +funny when I first started doing + + + align:start position:0% +funny when I first started doing +photography I said well all this + + align:start position:0% +photography I said well all this + + + align:start position:0% +photography I said well all this +sociology and history I've left behind + + align:start position:0% +sociology and history I've left behind + + + align:start position:0% +sociology and history I've left behind +but of course it informs all the work + + align:start position:0% +but of course it informs all the work + + + align:start position:0% +but of course it informs all the work +that I do so what I want to show you is + + align:start position:0% +that I do so what I want to show you is + + + align:start position:0% +that I do so what I want to show you is +a uh a a couple of projects one is a um + + align:start position:0% +a uh a a couple of projects one is a um + + + align:start position:0% +a uh a a couple of projects one is a um +a visual history project um I'll talk a + + align:start position:0% +a visual history project um I'll talk a + + + align:start position:0% +a visual history project um I'll talk a +little bit about I I decided not to show + + align:start position:0% +little bit about I I decided not to show + + + align:start position:0% +little bit about I I decided not to show +slides but this signage project project + + align:start position:0% +slides but this signage project project + + + align:start position:0% +slides but this signage project project +was um part of a team that was um uh + + align:start position:0% +was um part of a team that was um uh + + + align:start position:0% +was um part of a team that was um uh +commissioned by the the the de + + align:start position:0% +commissioned by the the the de + + + align:start position:0% +commissioned by the the the de +Redevelopment agency of the city of + + align:start position:0% +Redevelopment agency of the city of + + + align:start position:0% +Redevelopment agency of the city of +Richmond which is just nor north of uh + + align:start position:0% +Richmond which is just nor north of uh + + + align:start position:0% +Richmond which is just nor north of uh +Berkeley in um San Francisco and which + + align:start position:0% +Berkeley in um San Francisco and which + + + align:start position:0% +Berkeley in um San Francisco and which +was during World War II the um side of + + align:start position:0% +was during World War II the um side of + + + align:start position:0% +was during World War II the um side of +the Kaiser shipyards and uh that was + + align:start position:0% +the Kaiser shipyards and uh that was + + + align:start position:0% +the Kaiser shipyards and uh that was +also a place where a lot of people from + + align:start position:0% +also a place where a lot of people from + + + align:start position:0% +also a place where a lot of people from +all over the country came because there + + align:start position:0% +all over the country came because there + + + align:start position:0% +all over the country came because there +was work it was the first place where + + align:start position:0% +was work it was the first place where + + + align:start position:0% +was work it was the first place where +there was an integrated Workforce it was + + align:start position:0% +there was an integrated Workforce it was + + + align:start position:0% +there was an integrated Workforce it was +the birth of Rosie the Riveter um where + + align:start position:0% +the birth of Rosie the Riveter um where + + + align:start position:0% +the birth of Rosie the Riveter um where +women were actually welding as it's + + align:start position:0% +women were actually welding as it's + + + align:start position:0% +women were actually welding as it's +supposed to riveting but um but where + + align:start position:0% +supposed to riveting but um but where + + + align:start position:0% +supposed to riveting but um but where +women were uh integral part of the + + align:start position:0% +women were uh integral part of the + + + align:start position:0% +women were uh integral part of the +workforce um it was also a place that + + align:start position:0% +workforce um it was also a place that + + + align:start position:0% +workforce um it was also a place that +had segregated housing and um uh kind of + + align:start position:0% +had segregated housing and um uh kind of + + + align:start position:0% +had segregated housing and um uh kind of +sort of had patterns that were happening + + align:start position:0% +sort of had patterns that were happening + + + align:start position:0% +sort of had patterns that were happening +in other parts of the country but there + + align:start position:0% +in other parts of the country but there + + + align:start position:0% +in other parts of the country but there +was actually very little Trace so um a + + align:start position:0% +was actually very little Trace so um a + + + align:start position:0% +was actually very little Trace so um a +what uh people had been trying to do was + + align:start position:0% +what uh people had been trying to do was + + + align:start position:0% +what uh people had been trying to do was +to make the um sort of access to the Bay + + align:start position:0% +to make the um sort of access to the Bay + + + align:start position:0% +to make the um sort of access to the Bay +there was only something like a half + + align:start position:0% +there was only something like a half + + + align:start position:0% +there was only something like a half +mile access and uh there's now almost + + align:start position:0% +mile access and uh there's now almost + + + align:start position:0% +mile access and uh there's now almost +Total Access and eventually there's + + align:start position:0% +Total Access and eventually there's + + + align:start position:0% +Total Access and eventually there's +going to be a trail it'll um circum + + align:start position:0% +going to be a trail it'll um circum + + + align:start position:0% +going to be a trail it'll um circum +Amulet the bay and and like I can ride + + align:start position:0% +Amulet the bay and and like I can ride + + + align:start position:0% +Amulet the bay and and like I can ride +from my house in Port Richmond to + + align:start position:0% +from my house in Port Richmond to + + + align:start position:0% +from my house in Port Richmond to +Emeryville or to Oakland without bring + + align:start position:0% +Emeryville or to Oakland without bring + + + align:start position:0% +Emeryville or to Oakland without bring +in traffic going just along the bay and + + align:start position:0% +in traffic going just along the bay and + + + align:start position:0% +in traffic going just along the bay and +so in the area in Richmond there are + + align:start position:0% +so in the area in Richmond there are + + + align:start position:0% +so in the area in Richmond there are +these signs that have um dorothia Lang + + align:start position:0% +these signs that have um dorothia Lang + + + align:start position:0% +these signs that have um dorothia Lang +and other people's photographs and text + + align:start position:0% +and other people's photographs and text + + + align:start position:0% +and other people's photographs and text +of uh the social impact when the + + align:start position:0% +of uh the social impact when the + + + align:start position:0% +of uh the social impact when the +population of Richmond C trip in a + + align:start position:0% +population of Richmond C trip in a + + + align:start position:0% +population of Richmond C trip in a +course of 6 months so it was interesting + + align:start position:0% +course of 6 months so it was interesting + + + align:start position:0% +course of 6 months so it was interesting +to me to uh both collect that and also + + align:start position:0% +to me to uh both collect that and also + + + align:start position:0% +to me to uh both collect that and also +place that in a in an area where people + + align:start position:0% +place that in a in an area where people + + + align:start position:0% +place that in a in an area where people +who are using the the space for + + align:start position:0% +who are using the the space for + + + align:start position:0% +who are using the the space for +recreation the trail can actually see um + + align:start position:0% +recreation the trail can actually see um + + + align:start position:0% +recreation the trail can actually see um +this history which would been hidden so + + align:start position:0% +this history which would been hidden so + + + align:start position:0% +this history which would been hidden so +another um uh history project that I've + + align:start position:0% +another um uh history project that I've + + + align:start position:0% +another um uh history project that I've +been working on actually for about the + + align:start position:0% +been working on actually for about the + + + align:start position:0% +been working on actually for about the +last 10 or 15 years is um based on a set + + align:start position:0% +last 10 or 15 years is um based on a set + + + align:start position:0% +last 10 or 15 years is um based on a set +of photographs I found in a Sho shine + + align:start position:0% +of photographs I found in a Sho shine + + + align:start position:0% +of photographs I found in a Sho shine +parlor um uh + + align:start position:0% +parlor um uh + + + align:start position:0% +parlor um uh +and this is uh red pal or hopefully this + + align:start position:0% +and this is uh red pal or hopefully this + + + align:start position:0% +and this is uh red pal or hopefully this +will be hold on just a + + align:start position:0% + + + + align:start position:0% + +sec + + align:start position:0% +sec + + + align:start position:0% +sec +okay this is uh red pal in front of his + + align:start position:0% +okay this is uh red pal in front of his + + + align:start position:0% +okay this is uh red pal in front of his +uh shine parlor and red uh like a lot of + + align:start position:0% +uh shine parlor and red uh like a lot of + + + align:start position:0% +uh shine parlor and red uh like a lot of +um uh Barbers and beauticians and in + + align:start position:0% +um uh Barbers and beauticians and in + + + align:start position:0% +um uh Barbers and beauticians and in +this case uh shine parlor was actually a + + align:start position:0% +this case uh shine parlor was actually a + + + align:start position:0% +this case uh shine parlor was actually a +a uh archivist and he had photographs of + + align:start position:0% +a uh archivist and he had photographs of + + + align:start position:0% +a uh archivist and he had photographs of +every one who had uh been in this area + + align:start position:0% +every one who had uh been in this area + + + align:start position:0% +every one who had uh been in this area +in San Francisco The Filmore District + + align:start position:0% +in San Francisco The Filmore District + + + align:start position:0% +in San Francisco The Filmore District +which um had uh sort of instantly became + + align:start position:0% +which um had uh sort of instantly became + + + align:start position:0% +which um had uh sort of instantly became +a little Harlem in the early 40s uh when + + align:start position:0% +a little Harlem in the early 40s uh when + + + align:start position:0% +a little Harlem in the early 40s uh when +um uh people came West and in San + + align:start position:0% +um uh people came West and in San + + + align:start position:0% +um uh people came West and in San +Francisco the only place where there was + + align:start position:0% +Francisco the only place where there was + + + align:start position:0% +Francisco the only place where there was +available housing was what had been + + align:start position:0% +available housing was what had been + + + align:start position:0% +available housing was what had been +Japan town because the Japanese had been + + align:start position:0% +Japan town because the Japanese had been + + + align:start position:0% +Japan town because the Japanese had been +recently intered and it was uh it it + + align:start position:0% +recently intered and it was uh it it + + + align:start position:0% +recently intered and it was uh it it +already sort of had a built-in um uh set + + align:start position:0% +already sort of had a built-in um uh set + + + align:start position:0% +already sort of had a built-in um uh set +of of uh institutions that were um sort + + align:start position:0% +of of uh institutions that were um sort + + + align:start position:0% +of of uh institutions that were um sort +of taken over by African-Americans there + + align:start position:0% +of taken over by African-Americans there + + + align:start position:0% +of taken over by African-Americans there +were already there were clubs at at its + + align:start position:0% +were already there were clubs at at its + + + align:start position:0% +were already there were clubs at at its +height there were probably eight or nine + + align:start position:0% +height there were probably eight or nine + + + align:start position:0% +height there were probably eight or nine +jazz clubs there were three + + align:start position:0% +jazz clubs there were three + + + align:start position:0% +jazz clubs there were three +african-american-owned + + align:start position:0% +african-american-owned + + + align:start position:0% +african-american-owned +hotels um and there was a critical mass + + align:start position:0% +hotels um and there was a critical mass + + + align:start position:0% +hotels um and there was a critical mass +um of of people who had come to work in + + align:start position:0% +um of of people who had come to work in + + + align:start position:0% +um of of people who had come to work in +both um Hunter point and in the East Bay + + align:start position:0% +both um Hunter point and in the East Bay + + + align:start position:0% +both um Hunter point and in the East Bay +in the the shipyards and so um when I + + align:start position:0% +in the the shipyards and so um when I + + + align:start position:0% +in the the shipyards and so um when I +walked in in + + align:start position:0% +walked in in + + + align:start position:0% +walked in in +1989 uh someone had sent me to a shine + + align:start position:0% +1989 uh someone had sent me to a shine + + + align:start position:0% +1989 uh someone had sent me to a shine +parlor I got really excited and I said + + align:start position:0% +parlor I got really excited and I said + + + align:start position:0% +parlor I got really excited and I said +wow can I photograph walls and he was + + align:start position:0% +wow can I photograph walls and he was + + + align:start position:0% +wow can I photograph walls and he was +having none of it he basically threw me + + align:start position:0% +having none of it he basically threw me + + + align:start position:0% +having none of it he basically threw me +out of his Club of his shop so I came + + align:start position:0% +out of his Club of his shop so I came + + + align:start position:0% +out of his Club of his shop so I came +back a month later armed with some + + align:start position:0% +back a month later armed with some + + + align:start position:0% +back a month later armed with some +people that knew him and he was gone and + + align:start position:0% +people that knew him and he was gone and + + + align:start position:0% +people that knew him and he was gone and +the walls were bare um here's a picture + + align:start position:0% +the walls were bare um here's a picture + + + align:start position:0% +the walls were bare um here's a picture +of the um you can see if you can see in + + align:start position:0% +of the um you can see if you can see in + + + align:start position:0% +of the um you can see if you can see in +the walls there's a picture of Bobby + + align:start position:0% +the walls there's a picture of Bobby + + + align:start position:0% +the walls there's a picture of Bobby +Kennedy and Sitting Bull and Joseph + + align:start position:0% +Kennedy and Sitting Bull and Joseph + + + align:start position:0% +Kennedy and Sitting Bull and Joseph +Stalin and Jackie Robinson I mean really + + align:start position:0% +Stalin and Jackie Robinson I mean really + + + align:start position:0% +Stalin and Jackie Robinson I mean really +had and on other walls there were a lot + + align:start position:0% +had and on other walls there were a lot + + + align:start position:0% +had and on other walls there were a lot +of uh Jazz musicians so um what he was + + align:start position:0% +of uh Jazz musicians so um what he was + + + align:start position:0% +of uh Jazz musicians so um what he was +gone when I came back and it turned out + + align:start position:0% +gone when I came back and it turned out + + + align:start position:0% +gone when I came back and it turned out +uh after 5 years of searching that he + + align:start position:0% +uh after 5 years of searching that he + + + align:start position:0% +uh after 5 years of searching that he +had had a stroke literally two weeks + + align:start position:0% +had had a stroke literally two weeks + + + align:start position:0% +had had a stroke literally two weeks +after I'd seen him and so in the mid 90s + + align:start position:0% +after I'd seen him and so in the mid 90s + + + align:start position:0% +after I'd seen him and so in the mid 90s +I was working for the Redevelopment + + align:start position:0% +I was working for the Redevelopment + + + align:start position:0% +I was working for the Redevelopment +agency who will um come up a little + + align:start position:0% +agency who will um come up a little + + + align:start position:0% +agency who will um come up a little +later in the story uh because they were + + align:start position:0% +later in the story uh because they were + + + align:start position:0% +later in the story uh because they were +uh attempting to make a jazz + + align:start position:0% +uh attempting to make a jazz + + + align:start position:0% +uh attempting to make a jazz +preservation District in an area where + + align:start position:0% +preservation District in an area where + + + align:start position:0% +preservation District in an area where +very most of the trace of + + align:start position:0% +very most of the trace of + + + align:start position:0% +very most of the trace of +African-Americans had disappeared in the + + align:start position:0% +African-Americans had disappeared in the + + + align:start position:0% +African-Americans had disappeared in the +late 60s due to + + align:start position:0% +late 60s due to + + + align:start position:0% +late 60s due to +Redevelopment and for the h 100th time I + + align:start position:0% +Redevelopment and for the h 100th time I + + + align:start position:0% +Redevelopment and for the h 100th time I +asked uh Reggie Pettis the barber in the + + align:start position:0% +asked uh Reggie Pettis the barber in the + + + align:start position:0% +asked uh Reggie Pettis the barber in the +barber shop across the street do you + + align:start position:0% +barber shop across the street do you + + + align:start position:0% +barber shop across the street do you +know what happened to the photographs + + align:start position:0% +know what happened to the photographs + + + align:start position:0% +know what happened to the photographs +and he he said oh they're in my back + + align:start position:0% +and he he said oh they're in my back + + + align:start position:0% +and he he said oh they're in my back +room so what had happened was when when + + align:start position:0% +room so what had happened was when when + + + align:start position:0% +room so what had happened was when when +red um who's on the uh left had a stroke + + align:start position:0% +red um who's on the uh left had a stroke + + + align:start position:0% +red um who's on the uh left had a stroke +uh the landlord took all the photographs + + align:start position:0% +uh the landlord took all the photographs + + + align:start position:0% +uh the landlord took all the photographs +down um and was about to throw them out + + align:start position:0% +down um and was about to throw them out + + + align:start position:0% +down um and was about to throw them out +and Reggie rescued them and they'd been + + align:start position:0% +and Reggie rescued them and they'd been + + + align:start position:0% +and Reggie rescued them and they'd been +sitting in his back + + align:start position:0% +sitting in his back + + + align:start position:0% +sitting in his back +room and a lot of them were in in uh + + align:start position:0% +room and a lot of them were in in uh + + + align:start position:0% +room and a lot of them were in in uh +pretty bad shape so this was the + + align:start position:0% +pretty bad shape so this was the + + + align:start position:0% +pretty bad shape so this was the +opportunity in this case 10 years ago or + + align:start position:0% +opportunity in this case 10 years ago or + + + align:start position:0% +opportunity in this case 10 years ago or +8 years ago to learn Photoshop and um + + align:start position:0% +8 years ago to learn Photoshop and um + + + align:start position:0% +8 years ago to learn Photoshop and um +actually I had learned and I had + + align:start position:0% +actually I had learned and I had + + + align:start position:0% +actually I had learned and I had +students show me Photoshop probably four + + align:start position:0% +students show me Photoshop probably four + + + align:start position:0% +students show me Photoshop probably four +or five times but I really had not I was + + align:start position:0% +or five times but I really had not I was + + + align:start position:0% +or five times but I really had not I was +shooting film and I didn't really have + + align:start position:0% +shooting film and I didn't really have + + + align:start position:0% +shooting film and I didn't really have +that much interest but this was a + + align:start position:0% +that much interest but this was a + + + align:start position:0% +that much interest but this was a +project that was really important and so + + align:start position:0% +project that was really important and so + + + align:start position:0% +project that was really important and so +with Photoshop I was able to learn to + + align:start position:0% +with Photoshop I was able to learn to + + + align:start position:0% +with Photoshop I was able to learn to +restore the images and uh events they + + align:start position:0% +restore the images and uh events they + + + align:start position:0% +restore the images and uh events they +were using a report and then uh my + + align:start position:0% +were using a report and then uh my + + + align:start position:0% +were using a report and then uh my +friends at the San Francisco art + + align:start position:0% +friends at the San Francisco art + + + align:start position:0% +friends at the San Francisco art +commission said well you need to show + + align:start position:0% +commission said well you need to show + + + align:start position:0% +commission said well you need to show +these people need to see them so they + + align:start position:0% +these people need to see them so they + + + align:start position:0% +these people need to see them so they +were uh exhibited a number of times um + + align:start position:0% +were uh exhibited a number of times um + + + align:start position:0% +were uh exhibited a number of times um +some people doing research on the um the + + align:start position:0% +some people doing research on the um the + + + align:start position:0% +some people doing research on the um the +um + + align:start position:0% +um + + + align:start position:0% +um +uh area we're doing films used them and + + align:start position:0% +uh area we're doing films used them and + + + align:start position:0% +uh area we're doing films used them and +and they were used in a uh neighborhood + + align:start position:0% +and they were used in a uh neighborhood + + + align:start position:0% +and they were used in a uh neighborhood +documentary that kqbd the uh PBS station + + align:start position:0% +documentary that kqbd the uh PBS station + + + align:start position:0% +documentary that kqbd the uh PBS station +in San Francisco did on the Filmore and + + align:start position:0% +in San Francisco did on the Filmore and + + + align:start position:0% +in San Francisco did on the Filmore and +I was an adviser for that so in this + + align:start position:0% +I was an adviser for that so in this + + + align:start position:0% +I was an adviser for that so in this +group of photographs were photographs of + + align:start position:0% +group of photographs were photographs of + + + align:start position:0% +group of photographs were photographs of +life in this community um a lot of + + align:start position:0% +life in this community um a lot of + + + align:start position:0% +life in this community um a lot of +pictures of entertainers this is a VOD + + align:start position:0% +pictures of entertainers this is a VOD + + + align:start position:0% +pictures of entertainers this is a VOD +villian this picture is probably from + + align:start position:0% +villian this picture is probably from + + + align:start position:0% +villian this picture is probably from +the' 40s cuz the in front of the um + + align:start position:0% +the' 40s cuz the in front of the um + + + align:start position:0% +the' 40s cuz the in front of the um +California theater and you can see that + + align:start position:0% +California theater and you can see that + + + align:start position:0% +California theater and you can see that +the uh movie post ERS are World War II + + align:start position:0% +the uh movie post ERS are World War II + + + align:start position:0% +the uh movie post ERS are World War II +vintage here's a picture of Charlie + + align:start position:0% +vintage here's a picture of Charlie + + + align:start position:0% +vintage here's a picture of Charlie +Parker in front of uh in inside Jimbo's + + align:start position:0% +Parker in front of uh in inside Jimbo's + + + align:start position:0% +Parker in front of uh in inside Jimbo's +Bop city um an after hours place where a + + align:start position:0% +Bop city um an after hours place where a + + + align:start position:0% +Bop city um an after hours place where a +lot of musicians would come to jam after + + align:start position:0% +lot of musicians would come to jam after + + + align:start position:0% +lot of musicians would come to jam after +they came here's a publicity shot of Joe + + align:start position:0% +they came here's a publicity shot of Joe + + + align:start position:0% +they came here's a publicity shot of Joe +Lewis with Joe Lewis liquor and um the + + align:start position:0% +Lewis with Joe Lewis liquor and um the + + + align:start position:0% +Lewis with Joe Lewis liquor and um the +uh some some older gentlemen in front of + + align:start position:0% +uh some some older gentlemen in front of + + + align:start position:0% +uh some some older gentlemen in front of +the Burger King on Filmore said that + + align:start position:0% +the Burger King on Filmore said that + + + align:start position:0% +the Burger King on Filmore said that +that was the worst rot gut they ever + + align:start position:0% +that was the worst rot gut they ever + + + align:start position:0% +that was the worst rot gut they ever +tasted so it was interesting that I + + align:start position:0% +tasted so it was interesting that I + + + align:start position:0% +tasted so it was interesting that I +would eventually when I first got the + + align:start position:0% +would eventually when I first got the + + + align:start position:0% +would eventually when I first got the +photographs there was no labels I didn't + + align:start position:0% +photographs there was no labels I didn't + + + align:start position:0% +photographs there was no labels I didn't +know any of the people and as they + + align:start position:0% +know any of the people and as they + + + align:start position:0% +know any of the people and as they +started to have a public life I started + + align:start position:0% +started to have a public life I started + + + align:start position:0% +started to have a public life I started +meeting people um and I started meeting + + align:start position:0% +meeting people um and I started meeting + + + align:start position:0% +meeting people um and I started meeting +other photographers and other people who + + align:start position:0% +other photographers and other people who + + + align:start position:0% +other photographers and other people who +had had um collections this woman was + + align:start position:0% +had had um collections this woman was + + + align:start position:0% +had had um collections this woman was +named Vera the + + align:start position:0% +named Vera the + + + align:start position:0% +named Vera the +body here's a photograph taken probably + + align:start position:0% +body here's a photograph taken probably + + + align:start position:0% +body here's a photograph taken probably +after the Japanese came back a very U + + align:start position:0% +after the Japanese came back a very U + + + align:start position:0% +after the Japanese came back a very U +Multicultural wedding party and people + + align:start position:0% +Multicultural wedding party and people + + + align:start position:0% +Multicultural wedding party and people +said that that was one of the things + + align:start position:0% +said that that was one of the things + + + align:start position:0% +said that that was one of the things +that this community was um very + + align:start position:0% +that this community was um very + + + align:start position:0% +that this community was um very +Multicultural I did eventually did a + + align:start position:0% +Multicultural I did eventually did a + + + align:start position:0% +Multicultural I did eventually did a +public art uh piece on the street and + + align:start position:0% +public art uh piece on the street and + + + align:start position:0% +public art uh piece on the street and +and I remember seeing an old man in + + align:start position:0% +and I remember seeing an old man in + + + align:start position:0% +and I remember seeing an old man in +front of one of the posters and he said + + align:start position:0% +front of one of the posters and he said + + + align:start position:0% +front of one of the posters and he said +he came every day because it was the + + align:start position:0% +he came every day because it was the + + + align:start position:0% +he came every day because it was the +best time of his life here's a picture + + align:start position:0% +best time of his life here's a picture + + + align:start position:0% +best time of his life here's a picture +of Chad Baker uh inside + + align:start position:0% +of Chad Baker uh inside + + + align:start position:0% +of Chad Baker uh inside +jimbos there's if you see um uh just to + + align:start position:0% +jimbos there's if you see um uh just to + + + align:start position:0% +jimbos there's if you see um uh just to +the uh left is El Fitzgerald and next to + + align:start position:0% +the uh left is El Fitzgerald and next to + + + align:start position:0% +the uh left is El Fitzgerald and next to +her is is someone I had a lot of + + align:start position:0% +her is is someone I had a lot of + + + align:start position:0% +her is is someone I had a lot of +pictures of whose name was um uh Robert + + align:start position:0% +pictures of whose name was um uh Robert + + + align:start position:0% +pictures of whose name was um uh Robert +Lee and I called Robert Lee probably I + + align:start position:0% +Lee and I called Robert Lee probably I + + + align:start position:0% +Lee and I called Robert Lee probably I +tried to to meet with him probably over + + align:start position:0% +tried to to meet with him probably over + + + align:start position:0% +tried to to meet with him probably over +the course of two years and he always + + align:start position:0% +the course of two years and he always + + + align:start position:0% +the course of two years and he always +put me off he said oh my cat in the + + align:start position:0% +put me off he said oh my cat in the + + + align:start position:0% +put me off he said oh my cat in the +garage or I got to go to the hospital + + align:start position:0% +garage or I got to go to the hospital + + + align:start position:0% +garage or I got to go to the hospital +and then he died and so I was never able + + align:start position:0% +and then he died and so I was never able + + + align:start position:0% +and then he died and so I was never able +to talk to him and I know he would have + + align:start position:0% +to talk to him and I know he would have + + + align:start position:0% +to talk to him and I know he would have +had the some of these stories here's a + + align:start position:0% +had the some of these stories here's a + + + align:start position:0% +had the some of these stories here's a +picture of him at uh Jack which was a + + align:start position:0% +picture of him at uh Jack which was a + + + align:start position:0% +picture of him at uh Jack which was a +famous bar a lot of the clubs um had um + + align:start position:0% +famous bar a lot of the clubs um had um + + + align:start position:0% +famous bar a lot of the clubs um had um +pictures of of uh Jazz and other + + align:start position:0% +pictures of of uh Jazz and other + + + align:start position:0% +pictures of of uh Jazz and other +entertainers on the uh um painted on the + + align:start position:0% +entertainers on the uh um painted on the + + + align:start position:0% +entertainers on the uh um painted on the +back of the seats and I was told that + + align:start position:0% +back of the seats and I was told that + + + align:start position:0% +back of the seats and I was told that +this woman is actually now a prominent + + align:start position:0% +this woman is actually now a prominent + + + align:start position:0% +this woman is actually now a prominent +socialite in San Francisco who probably + + align:start position:0% +socialite in San Francisco who probably + + + align:start position:0% +socialite in San Francisco who probably +would not be happy to know this + + align:start position:0% +would not be happy to know this + + + align:start position:0% +would not be happy to know this +Photograph still + + align:start position:0% +Photograph still + + + align:start position:0% +Photograph still +existed um here's a a barber uh shop + + align:start position:0% +existed um here's a a barber uh shop + + + align:start position:0% +existed um here's a a barber uh shop +where um someone's getting his hair + + align:start position:0% +where um someone's getting his hair + + + align:start position:0% +where um someone's getting his hair +processed um this is uh one of the + + align:start position:0% +processed um this is uh one of the + + + align:start position:0% +processed um this is uh one of the +publicity pictures this was a group + + align:start position:0% +publicity pictures this was a group + + + align:start position:0% +publicity pictures this was a group +called The Four Naturals and I actually + + align:start position:0% +called The Four Naturals and I actually + + + align:start position:0% +called The Four Naturals and I actually +have three or four of these this kind of + + align:start position:0% +have three or four of these this kind of + + + align:start position:0% +have three or four of these this kind of +motif where The Pianist who was always + + align:start position:0% +motif where The Pianist who was always + + + align:start position:0% +motif where The Pianist who was always +different was at this kind of um rounded + + align:start position:0% +different was at this kind of um rounded + + + align:start position:0% +different was at this kind of um rounded +faux keyboard The Pianist is actually + + align:start position:0% +faux keyboard The Pianist is actually + + + align:start position:0% +faux keyboard The Pianist is actually +Frank Jackson Who Um I met and who + + align:start position:0% +Frank Jackson Who Um I met and who + + + align:start position:0% +Frank Jackson Who Um I met and who +actually gave uh contributed photographs + + align:start position:0% +actually gave uh contributed photographs + + + align:start position:0% +actually gave uh contributed photographs +and oral history here's another + + align:start position:0% +and oral history here's another + + + align:start position:0% +and oral history here's another +photograph of him um and when we there's + + align:start position:0% +photograph of him um and when we there's + + + align:start position:0% +photograph of him um and when we there's +an exhibit of this work and um a lot of + + align:start position:0% +an exhibit of this work and um a lot of + + + align:start position:0% +an exhibit of this work and um a lot of +the musicians from the period played um + + align:start position:0% +the musicians from the period played um + + + align:start position:0% +the musicians from the period played um +but here's a picture Frank um celebrated + + align:start position:0% +but here's a picture Frank um celebrated + + + align:start position:0% +but here's a picture Frank um celebrated +his 80th birthday uh couple of months + + align:start position:0% +his 80th birthday uh couple of months + + + align:start position:0% +his 80th birthday uh couple of months +ago at Yoshi's in Oakland so he's still + + align:start position:0% +ago at Yoshi's in Oakland so he's still + + + align:start position:0% +ago at Yoshi's in Oakland so he's still +playing and that's been thrilling to + + align:start position:0% +playing and that's been thrilling to + + + align:start position:0% +playing and that's been thrilling to +meet people who I've been looking + + align:start position:0% +meet people who I've been looking + + + align:start position:0% +meet people who I've been looking +photographs up and actually hear them + + align:start position:0% +photographs up and actually hear them + + + align:start position:0% +photographs up and actually hear them +playing um when I did a neighborhood + + align:start position:0% +playing um when I did a neighborhood + + + align:start position:0% +playing um when I did a neighborhood +walk in there was a a gentleman who kept + + align:start position:0% +walk in there was a a gentleman who kept + + + align:start position:0% +walk in there was a a gentleman who kept +correcting me as I was sort of saying + + align:start position:0% +correcting me as I was sort of saying + + + align:start position:0% +correcting me as I was sort of saying +things as I believed them and it turned + + align:start position:0% +things as I believed them and it turned + + + align:start position:0% +things as I believed them and it turned +out he was uh Wesley Johnson Jr and his + + align:start position:0% +out he was uh Wesley Johnson Jr and his + + + align:start position:0% +out he was uh Wesley Johnson Jr and his +father own the Texas Playhouse which was + + align:start position:0% +father own the Texas Playhouse which was + + + align:start position:0% +father own the Texas Playhouse which was +basically sort of a hangout for uh + + align:start position:0% +basically sort of a hangout for uh + + + align:start position:0% +basically sort of a hangout for uh +people from Texas and his signature was + + align:start position:0% +people from Texas and his signature was + + + align:start position:0% +people from Texas and his signature was +sort of wearing that white 10 gallon + + align:start position:0% +sort of wearing that white 10 gallon + + + align:start position:0% +sort of wearing that white 10 gallon +ston hat here's a p here he is posing + + align:start position:0% +ston hat here's a p here he is posing + + + align:start position:0% +ston hat here's a p here he is posing +with uh T-Bone Walker who was a star of + + align:start position:0% +with uh T-Bone Walker who was a star of + + + align:start position:0% +with uh T-Bone Walker who was a star of +the day um uh and if you if you've heard + + align:start position:0% +the day um uh and if you if you've heard + + + align:start position:0% +the day um uh and if you if you've heard +him play you know where Chuck Barry + + align:start position:0% +him play you know where Chuck Barry + + + align:start position:0% +him play you know where Chuck Barry +Chuck Barry got all his licks so he the + + align:start position:0% +Chuck Barry got all his licks so he the + + + align:start position:0% +Chuck Barry got all his licks so he the +the after meeting with Wesley he + + align:start position:0% +the after meeting with Wesley he + + + align:start position:0% +the after meeting with Wesley he +actually gave us his father's albums and + + align:start position:0% +actually gave us his father's albums and + + + align:start position:0% +actually gave us his father's albums and +it turned out his father had given Red a + + align:start position:0% +it turned out his father had given Red a + + + align:start position:0% +it turned out his father had given Red a +lot of the work that he had on his walls + + align:start position:0% +lot of the work that he had on his walls + + + align:start position:0% +lot of the work that he had on his walls +so the sort of all these connecting and + + align:start position:0% +so the sort of all these connecting and + + + align:start position:0% +so the sort of all these connecting and +the sort of collection of images and + + align:start position:0% +the sort of collection of images and + + + align:start position:0% +the sort of collection of images and +Arch kept growing and growing um here's + + align:start position:0% +Arch kept growing and growing um here's + + + align:start position:0% +Arch kept growing and growing um here's +a picture of some church lady so it was + + align:start position:0% +a picture of some church lady so it was + + + align:start position:0% +a picture of some church lady so it was +a nightclub but I think people would use + + align:start position:0% +a nightclub but I think people would use + + + align:start position:0% +a nightclub but I think people would use +it for other things um on the walls he + + align:start position:0% +it for other things um on the walls he + + + align:start position:0% +it for other things um on the walls he +had these murals um these were all Texas + + align:start position:0% +had these murals um these were all Texas + + + align:start position:0% +had these murals um these were all Texas +musicians Saunders King was a wellknown + + align:start position:0% +musicians Saunders King was a wellknown + + + align:start position:0% +musicians Saunders King was a wellknown +and had a hit in a star in San Francisco + + align:start position:0% +and had a hit in a star in San Francisco + + + align:start position:0% +and had a hit in a star in San Francisco +and V his daughter is married to Carlos + + align:start position:0% +and V his daughter is married to Carlos + + + align:start position:0% +and V his daughter is married to Carlos +Santana um I think who else is here uh + + align:start position:0% +Santana um I think who else is here uh + + + align:start position:0% +Santana um I think who else is here uh +John Hinton I'm not sure but Ivory Joe + + align:start position:0% +John Hinton I'm not sure but Ivory Joe + + + align:start position:0% +John Hinton I'm not sure but Ivory Joe +Hunter was a Pianist from Texas so in + + align:start position:0% +Hunter was a Pianist from Texas so in + + + align:start position:0% +Hunter was a Pianist from Texas so in +his album I noticed there were all these + + align:start position:0% +his album I noticed there were all these + + + align:start position:0% +his album I noticed there were all these +paintings and I saw them in other + + align:start position:0% +paintings and I saw them in other + + + align:start position:0% +paintings and I saw them in other +people's photographs that were on the + + align:start position:0% +people's photographs that were on the + + + align:start position:0% +people's photographs that were on the +walls they were done by um uh an artist + + align:start position:0% +walls they were done by um uh an artist + + + align:start position:0% +walls they were done by um uh an artist +named um I'm going to probably get his + + align:start position:0% +named um I'm going to probably get his + + + align:start position:0% +named um I'm going to probably get his +name wrong I think it's Hinton and he + + align:start position:0% +name wrong I think it's Hinton and he + + + align:start position:0% +name wrong I think it's Hinton and he +actually designed the logo for + + align:start position:0% +actually designed the logo for + + + align:start position:0% +actually designed the logo for +Fisherman's Warf and designed the + + align:start position:0% +Fisherman's Warf and designed the + + + align:start position:0% +Fisherman's Warf and designed the +Oakland Paramount which is a really + + align:start position:0% +Oakland Paramount which is a really + + + align:start position:0% +Oakland Paramount which is a really +strong Art Deco so I kept seeing these + + align:start position:0% +strong Art Deco so I kept seeing these + + + align:start position:0% +strong Art Deco so I kept seeing these +paintings and one day I got a letter um + + align:start position:0% +paintings and one day I got a letter um + + + align:start position:0% +paintings and one day I got a letter um +from someone said I have the paintings + + align:start position:0% +from someone said I have the paintings + + + align:start position:0% +from someone said I have the paintings +in my basement um here's a picture of of + + align:start position:0% +in my basement um here's a picture of of + + + align:start position:0% +in my basement um here's a picture of of +Wesley with his two bartender and his + + align:start position:0% +Wesley with his two bartender and his + + + align:start position:0% +Wesley with his two bartender and his +partner and so I went to see um this + + align:start position:0% +partner and so I went to see um this + + + align:start position:0% +partner and so I went to see um this +gentleman and there were these paintings + + align:start position:0% +gentleman and there were these paintings + + + align:start position:0% +gentleman and there were these paintings +I'd been looking at for 5 years they're + + align:start position:0% +I'd been looking at for 5 years they're + + + align:start position:0% +I'd been looking at for 5 years they're +absolutely beautiful and they're they're + + align:start position:0% +absolutely beautiful and they're they're + + + align:start position:0% +absolutely beautiful and they're they're +they're uh gold flaked and they're 50 + + align:start position:0% +they're uh gold flaked and they're 50 + + + align:start position:0% +they're uh gold flaked and they're 50 +years old and in incredible shape so + + align:start position:0% +years old and in incredible shape so + + + align:start position:0% +years old and in incredible shape so +they're in the exhibit um which is + + align:start position:0% +they're in the exhibit um which is + + + align:start position:0% +they're in the exhibit um which is +thrilling and and it turned out when the + + align:start position:0% +thrilling and and it turned out when the + + + align:start position:0% +thrilling and and it turned out when the +Texas Playhouse was being um demolished + + align:start position:0% +Texas Playhouse was being um demolished + + + align:start position:0% +Texas Playhouse was being um demolished +as we're a lot of the clubs in the late + + align:start position:0% +as we're a lot of the clubs in the late + + + align:start position:0% +as we're a lot of the clubs in the late +60s the Ukrainian contractor said oh + + align:start position:0% +60s the Ukrainian contractor said oh + + + align:start position:0% +60s the Ukrainian contractor said oh +great I can uh bring these paintings + + align:start position:0% +great I can uh bring these paintings + + + align:start position:0% +great I can uh bring these paintings +home and and Salvage the plywood so when + + align:start position:0% +home and and Salvage the plywood so when + + + align:start position:0% +home and and Salvage the plywood so when +he brought him home his wife said you + + align:start position:0% +he brought him home his wife said you + + + align:start position:0% +he brought him home his wife said you +will do no such thing that's this is Art + + align:start position:0% +will do no such thing that's this is Art + + + align:start position:0% +will do no such thing that's this is Art +so they gave the paintings to their + + align:start position:0% +so they gave the paintings to their + + + align:start position:0% +so they gave the paintings to their +neighbors African American neighbors who + + align:start position:0% +neighbors African American neighbors who + + + align:start position:0% +neighbors African American neighbors who +had grown up in the Filmore and Willie + + align:start position:0% +had grown up in the Filmore and Willie + + + align:start position:0% +had grown up in the Filmore and Willie +had kept them I mean he' kept them in a + + align:start position:0% +had kept them I mean he' kept them in a + + + align:start position:0% +had kept them I mean he' kept them in a +dry uh dark room for the last 30 years + + align:start position:0% +dry uh dark room for the last 30 years + + + align:start position:0% +dry uh dark room for the last 30 years +so he was again an incredible conser + + align:start position:0% +so he was again an incredible conser + + + align:start position:0% +so he was again an incredible conser +conservator his um here's a photograph + + align:start position:0% +conservator his um here's a photograph + + + align:start position:0% +conservator his um here's a photograph +of Lionel Hampton and it turned out I'd + + align:start position:0% +of Lionel Hampton and it turned out I'd + + + align:start position:0% +of Lionel Hampton and it turned out I'd +been looking at this photograph for a + + align:start position:0% +been looking at this photograph for a + + + align:start position:0% +been looking at this photograph for a +long time and this is um Robert brassard + + align:start position:0% +long time and this is um Robert brassard + + + align:start position:0% +long time and this is um Robert brassard +who is the uncle of my friend Tony + + align:start position:0% +who is the uncle of my friend Tony + + + align:start position:0% +who is the uncle of my friend Tony +brassard who's a a writer who does a + + align:start position:0% +brassard who's a a writer who does a + + + align:start position:0% +brassard who's a a writer who does a +remembrance of him and they lived in the + + align:start position:0% +remembrance of him and they lived in the + + + align:start position:0% +remembrance of him and they lived in the +East Bay but they would get dressed up + + align:start position:0% +East Bay but they would get dressed up + + + align:start position:0% +East Bay but they would get dressed up +every weekend this was a sweetheart they + + align:start position:0% +every weekend this was a sweetheart they + + + align:start position:0% +every weekend this was a sweetheart they +never married but they were uh went + + align:start position:0% +never married but they were uh went + + + align:start position:0% +never married but they were uh went +together for a long time and they would + + align:start position:0% +together for a long time and they would + + + align:start position:0% +together for a long time and they would +dress and go to the film War every + + align:start position:0% +dress and go to the film War every + + + align:start position:0% +dress and go to the film War every +weekend and so here he is in front of + + align:start position:0% +weekend and so here he is in front of + + + align:start position:0% +weekend and so here he is in front of +this painting that I've actually now + + align:start position:0% +this painting that I've actually now + + + align:start position:0% +this painting that I've actually now +touched it's sort of it um one of the + + align:start position:0% +touched it's sort of it um one of the + + + align:start position:0% +touched it's sort of it um one of the +the clubs that was prominent in this + + align:start position:0% +the clubs that was prominent in this + + + align:start position:0% +the clubs that was prominent in this +neighborhood was the Filmore the same + + align:start position:0% +neighborhood was the Filmore the same + + + align:start position:0% +neighborhood was the Filmore the same +Filmore that some of you have probably + + align:start position:0% +Filmore that some of you have probably + + + align:start position:0% +Filmore that some of you have probably +heard of and that Bill Graham eventually + + align:start position:0% +heard of and that Bill Graham eventually + + + align:start position:0% +heard of and that Bill Graham eventually +ran but before that it was a rhythm and + + align:start position:0% +ran but before that it was a rhythm and + + + align:start position:0% +ran but before that it was a rhythm and +blues venue um run by Charles Sullivan + + align:start position:0% +blues venue um run by Charles Sullivan + + + align:start position:0% +blues venue um run by Charles Sullivan +who is the considered the mayor of of + + align:start position:0% +who is the considered the mayor of of + + + align:start position:0% +who is the considered the mayor of of +the Filmore and here's a poster of + + align:start position:0% +the Filmore and here's a poster of + + + align:start position:0% +the Filmore and here's a poster of +Little Richard uh playing at the fil + + align:start position:0% +Little Richard uh playing at the fil + + + align:start position:0% +Little Richard uh playing at the fil +more I love there was this sort of + + align:start position:0% +more I love there was this sort of + + + align:start position:0% +more I love there was this sort of +aesthetic I've seen all over the the + + align:start position:0% +aesthetic I've seen all over the the + + + align:start position:0% +aesthetic I've seen all over the the +country at the Howard Theater in + + align:start position:0% +country at the Howard Theater in + + + align:start position:0% +country at the Howard Theater in +Washington at the the Regal in Chicago + + align:start position:0% +Washington at the the Regal in Chicago + + + align:start position:0% +Washington at the the Regal in Chicago +there was a certain way of doing offset + + align:start position:0% +there was a certain way of doing offset + + + align:start position:0% +there was a certain way of doing offset +printing in Rhythm uh Blues venues so + + align:start position:0% +printing in Rhythm uh Blues venues so + + + align:start position:0% +printing in Rhythm uh Blues venues so +here's uh Little Richard who's returning + + align:start position:0% +here's uh Little Richard who's returning + + + align:start position:0% +here's uh Little Richard who's returning +from a Triumph in England and um uh John + + align:start position:0% +from a Triumph in England and um uh John + + + align:start position:0% +from a Triumph in England and um uh John +Godard who now has a incredible record + + align:start position:0% +Godard who now has a incredible record + + + align:start position:0% +Godard who now has a incredible record +store in mil valy California was a + + align:start position:0% +store in mil valy California was a + + + align:start position:0% +store in mil valy California was a +14-year-old kid who took the bus in to + + align:start position:0% +14-year-old kid who took the bus in to + + + align:start position:0% +14-year-old kid who took the bus in to +see Little Richard and and took a + + align:start position:0% +see Little Richard and and took a + + + align:start position:0% +see Little Richard and and took a +picture with the Brownie and Little + + align:start position:0% +picture with the Brownie and Little + + + align:start position:0% +picture with the Brownie and Little +Richard had this left-handed guitarist + + align:start position:0% +Richard had this left-handed guitarist + + + align:start position:0% +Richard had this left-handed guitarist +who was really frustrating John because + + align:start position:0% +who was really frustrating John because + + + align:start position:0% +who was really frustrating John because +he kept getting in the way of Little + + align:start position:0% +he kept getting in the way of Little + + + align:start position:0% +he kept getting in the way of Little +Richard and that guitarist was James + + align:start position:0% +Richard and that guitarist was James + + + align:start position:0% +Richard and that guitarist was James +Marshall Hendricks this is I think one + + align:start position:0% +Marshall Hendricks this is I think one + + + align:start position:0% +Marshall Hendricks this is I think one +of the few and Little Richard fired him + + align:start position:0% +of the few and Little Richard fired him + + + align:start position:0% +of the few and Little Richard fired him +after 6 months cuz he was too weird + + align:start position:0% +after 6 months cuz he was too weird + + + align:start position:0% +after 6 months cuz he was too weird +which I thought was quite interesting so + + align:start position:0% +which I thought was quite interesting so + + + align:start position:0% +which I thought was quite interesting so +anyway in this collection here's a a + + align:start position:0% +anyway in this collection here's a a + + + align:start position:0% +anyway in this collection here's a a +picture in front of um Melrose records + + align:start position:0% +picture in front of um Melrose records + + + align:start position:0% +picture in front of um Melrose records +and in the window is a a sign for a a + + align:start position:0% +and in the window is a a sign for a a + + + align:start position:0% +and in the window is a a sign for a a +hit of the day called bbo is dead bill + + align:start position:0% +hit of the day called bbo is dead bill + + + align:start position:0% +hit of the day called bbo is dead bill +was a governor of Mississippi who was a + + align:start position:0% +was a governor of Mississippi who was a + + + align:start position:0% +was a governor of Mississippi who was a +St segregationist and when he died + + align:start position:0% +St segregationist and when he died + + + align:start position:0% +St segregationist and when he died +someone made a hit in celebration of + + align:start position:0% +someone made a hit in celebration of + + + align:start position:0% +someone made a hit in celebration of +that fact so in the meantime um this + + align:start position:0% +that fact so in the meantime um this + + + align:start position:0% +that fact so in the meantime um this +sort of collection is growing and I met + + align:start position:0% +sort of collection is growing and I met + + + align:start position:0% +sort of collection is growing and I met +a friend a woman um Janet Alvarado whose + + align:start position:0% +a friend a woman um Janet Alvarado whose + + + align:start position:0% +a friend a woman um Janet Alvarado whose +father had come to San Francisco in the + + align:start position:0% +father had come to San Francisco in the + + + align:start position:0% +father had come to San Francisco in the +first wave of Filipino immigrants there + + align:start position:0% +first wave of Filipino immigrants there + + + align:start position:0% +first wave of Filipino immigrants there +was sort of a bachelor society and he + + align:start position:0% +was sort of a bachelor society and he + + + align:start position:0% +was sort of a bachelor society and he +had taught himself photography and he + + align:start position:0% +had taught himself photography and he + + + align:start position:0% +had taught himself photography and he +worked in the kitchen in the predio the + + align:start position:0% +worked in the kitchen in the predio the + + + align:start position:0% +worked in the kitchen in the predio the +army base in San Francisco and as is the + + align:start position:0% +army base in San Francisco and as is the + + + align:start position:0% +army base in San Francisco and as is the +case a lot of people of color worked in + + align:start position:0% +case a lot of people of color worked in + + + align:start position:0% +case a lot of people of color worked in +the predio and he lived in in the + + align:start position:0% +the predio and he lived in in the + + + align:start position:0% +the predio and he lived in in the +Filmore and went to to uh clubs he also + + align:start position:0% +Filmore and went to to uh clubs he also + + + align:start position:0% +Filmore and went to to uh clubs he also +did a lot of photography of Filipino and + + align:start position:0% +did a lot of photography of Filipino and + + + align:start position:0% +did a lot of photography of Filipino and +Hispanic communities and in fact the + + align:start position:0% +Hispanic communities and in fact the + + + align:start position:0% +Hispanic communities and in fact the +Smithsonian has an exhibit that his + + align:start position:0% +Smithsonian has an exhibit that his + + + align:start position:0% +Smithsonian has an exhibit that his +daughter um organized um but he has + + align:start position:0% +daughter um organized um but he has + + + align:start position:0% +daughter um organized um but he has +thousands of 4x5 negatives so he um this + + align:start position:0% +thousands of 4x5 negatives so he um this + + + align:start position:0% +thousands of 4x5 negatives so he um this +is a picture in a house party that he + + align:start position:0% +is a picture in a house party that he + + + align:start position:0% +is a picture in a house party that he +took um that he contributed to the book + + align:start position:0% +took um that he contributed to the book + + + align:start position:0% +took um that he contributed to the book +and then here's a photograph done by + + align:start position:0% +and then here's a photograph done by + + + align:start position:0% +and then here's a photograph done by +Steve Jackson who is the official + + align:start position:0% +Steve Jackson who is the official + + + align:start position:0% +Steve Jackson who is the official +photographer of the um Jimbo's Bob city + + align:start position:0% +photographer of the um Jimbo's Bob city + + + align:start position:0% +photographer of the um Jimbo's Bob city +which I said was a a well-known after + + align:start position:0% +which I said was a a well-known after + + + align:start position:0% +which I said was a a well-known after +hours place there was actually a Bop + + align:start position:0% +hours place there was actually a Bop + + + align:start position:0% +hours place there was actually a Bop +city in in New York and um someone uh + + align:start position:0% +city in in New York and um someone uh + + + align:start position:0% +city in in New York and um someone uh +slim gayer who was a musician and tried + + align:start position:0% +slim gayer who was a musician and tried + + + align:start position:0% +slim gayer who was a musician and tried +to be an entrepreneur opened up a club + + align:start position:0% +to be an entrepreneur opened up a club + + + align:start position:0% +to be an entrepreneur opened up a club +called vout City if you know about slim + + align:start position:0% +called vout City if you know about slim + + + align:start position:0% +called vout City if you know about slim +and slam vout and vout oon was a a + + align:start position:0% +and slam vout and vout oon was a a + + + align:start position:0% +and slam vout and vout oon was a a +saying of the day but it didn't last + + align:start position:0% +saying of the day but it didn't last + + + align:start position:0% +saying of the day but it didn't last +very long so um uh it was taken over by + + align:start position:0% +very long so um uh it was taken over by + + + align:start position:0% +very long so um uh it was taken over by +uh + + align:start position:0% +uh + + + align:start position:0% +uh +uh someone else and it basically opened + + align:start position:0% +uh someone else and it basically opened + + + align:start position:0% +uh someone else and it basically opened +at 2 a.m. uh you had to bring your own + + align:start position:0% +at 2 a.m. uh you had to bring your own + + + align:start position:0% +at 2 a.m. uh you had to bring your own +liquor and a lot of the musicians who + + align:start position:0% +liquor and a lot of the musicians who + + + align:start position:0% +liquor and a lot of the musicians who +were playing would come there was a sort + + align:start position:0% +were playing would come there was a sort + + + align:start position:0% +were playing would come there was a sort +of house Rhythm Section and people would + + align:start position:0% +of house Rhythm Section and people would + + + align:start position:0% +of house Rhythm Section and people would +show up so on this is on the cover of + + align:start position:0% +show up so on this is on the cover of + + + align:start position:0% +show up so on this is on the cover of +the book and um on the left is John + + align:start position:0% +the book and um on the left is John + + + align:start position:0% +the book and um on the left is John +handy who lives in the Bay Area who's + + align:start position:0% +handy who lives in the Bay Area who's + + + align:start position:0% +handy who lives in the Bay Area who's +well known that's poy po Dexter next to + + align:start position:0% +well known that's poy po Dexter next to + + + align:start position:0% +well known that's poy po Dexter next to +him uh and then next to him was at the + + align:start position:0% +him uh and then next to him was at the + + + align:start position:0% +him uh and then next to him was at the +time a young saxophone player John col + + align:start position:0% +time a young saxophone player John col + + + align:start position:0% +time a young saxophone player John col +train and next to him was Frank fiser so + + align:start position:0% +train and next to him was Frank fiser so + + + align:start position:0% +train and next to him was Frank fiser so +so um a couple of months ago when the + + align:start position:0% +so um a couple of months ago when the + + + align:start position:0% +so um a couple of months ago when the +exhibit opened we had a a concert with + + align:start position:0% +exhibit opened we had a a concert with + + + align:start position:0% +exhibit opened we had a a concert with +the Filmore preservation big band and + + align:start position:0% +the Filmore preservation big band and + + + align:start position:0% +the Filmore preservation big band and +two of the re surviving members that's + + align:start position:0% +two of the re surviving members that's + + + align:start position:0% +two of the re surviving members that's +John handy second from the left and + + align:start position:0% +John handy second from the left and + + + align:start position:0% +John handy second from the left and +Frank fiser next to him so again it was + + align:start position:0% +Frank fiser next to him so again it was + + + align:start position:0% +Frank fiser next to him so again it was +just thrilling and they still could play + + align:start position:0% +just thrilling and they still could play + + + align:start position:0% +just thrilling and they still could play +um they they were able to play and I I + + align:start position:0% +um they they were able to play and I I + + + align:start position:0% +um they they were able to play and I I +love that whole thing coming together so + + align:start position:0% +love that whole thing coming together so + + + align:start position:0% +love that whole thing coming together so +what happened was there would sort of + + align:start position:0% +what happened was there would sort of + + + align:start position:0% +what happened was there would sort of +move a foot to uh redevelop this area it + + align:start position:0% +move a foot to uh redevelop this area it + + + align:start position:0% +move a foot to uh redevelop this area it +was it had a stock of uh Victorian house + + align:start position:0% +was it had a stock of uh Victorian house + + + align:start position:0% +was it had a stock of uh Victorian house +houses um and um I have we have uh + + align:start position:0% +houses um and um I have we have uh + + + align:start position:0% +houses um and um I have we have uh +photographs from the Redevelopment + + align:start position:0% +photographs from the Redevelopment + + + align:start position:0% +photographs from the Redevelopment +agency where buildings were numbered and + + align:start position:0% +agency where buildings were numbered and + + + align:start position:0% +agency where buildings were numbered and +a lot of them were torn down and a lot + + align:start position:0% +a lot of them were torn down and a lot + + + align:start position:0% +a lot of them were torn down and a lot +of people were displaced with the idea + + align:start position:0% +of people were displaced with the idea + + + align:start position:0% +of people were displaced with the idea +that they would be put on a list and be + + align:start position:0% +that they would be put on a list and be + + + align:start position:0% +that they would be put on a list and be +the first to be able to come back and so + + align:start position:0% +the first to be able to come back and so + + + align:start position:0% +the first to be able to come back and so +it turned out that much of the Filmore + + align:start position:0% +it turned out that much of the Filmore + + + align:start position:0% +it turned out that much of the Filmore +looked like this for years and years + + align:start position:0% +looked like this for years and years + + + align:start position:0% +looked like this for years and years +that that um the buildings seemed to be + + align:start position:0% +that that um the buildings seemed to be + + + align:start position:0% +that that um the buildings seemed to be +people were displaced and the buildings + + align:start position:0% +people were displaced and the buildings + + + align:start position:0% +people were displaced and the buildings +were torn down quickly but it turned out + + align:start position:0% +were torn down quickly but it turned out + + + align:start position:0% +were torn down quickly but it turned out +I think one family on that list was able + + align:start position:0% +I think one family on that list was able + + + align:start position:0% +I think one family on that list was able +to resettle so um that obviously was + + align:start position:0% +to resettle so um that obviously was + + + align:start position:0% +to resettle so um that obviously was +devastating to a lot of people and it's + + align:start position:0% +devastating to a lot of people and it's + + + align:start position:0% +devastating to a lot of people and it's +no accident that a large percentage of + + align:start position:0% +no accident that a large percentage of + + + align:start position:0% +no accident that a large percentage of +the people who died in Guana with Jim + + align:start position:0% +the people who died in Guana with Jim + + + align:start position:0% +the people who died in Guana with Jim +Jones who had a church right next to the + + align:start position:0% +Jones who had a church right next to the + + + align:start position:0% +Jones who had a church right next to the +Filmore Auditorium were people from the + + align:start position:0% +Filmore Auditorium were people from the + + + align:start position:0% +Filmore Auditorium were people from the +Filmore or The Offspring of people um + + align:start position:0% +Filmore or The Offspring of people um + + + align:start position:0% +Filmore or The Offspring of people um +and there was no Trace PE there was + + align:start position:0% +and there was no Trace PE there was + + + align:start position:0% +and there was no Trace PE there was +there people I think people have studied + + align:start position:0% +there people I think people have studied + + + align:start position:0% +there people I think people have studied +their planners here who that the Filmore + + align:start position:0% +their planners here who that the Filmore + + + align:start position:0% +their planners here who that the Filmore +has been studied a lot as a sort of + + align:start position:0% +has been studied a lot as a sort of + + + align:start position:0% +has been studied a lot as a sort of +attempt at um Redevelopment that didn't + + align:start position:0% +attempt at um Redevelopment that didn't + + + align:start position:0% +attempt at um Redevelopment that didn't +go very well and some people say that it + + align:start position:0% +go very well and some people say that it + + + align:start position:0% +go very well and some people say that it +was the intention of the developers that + + align:start position:0% +was the intention of the developers that + + + align:start position:0% +was the intention of the developers that +they didn't like the idea of they're in + + align:start position:0% +they didn't like the idea of they're in + + + align:start position:0% +they didn't like the idea of they're in +a prominent area in San Francisco was + + align:start position:0% +a prominent area in San Francisco was + + + align:start position:0% +a prominent area in San Francisco was +African-American Community it turned out + + align:start position:0% +African-American Community it turned out + + + align:start position:0% +African-American Community it turned out +a lot of them were displaced to other + + align:start position:0% +a lot of them were displaced to other + + + align:start position:0% +a lot of them were displaced to other +places but some of them ended up in the + + align:start position:0% +places but some of them ended up in the + + + align:start position:0% +places but some of them ended up in the +area um uh so it was important to me uh + + align:start position:0% +area um uh so it was important to me uh + + + align:start position:0% +area um uh so it was important to me uh +the first sort of pup that to exhibit + + align:start position:0% +the first sort of pup that to exhibit + + + align:start position:0% +the first sort of pup that to exhibit +that work and then this is actually um + + align:start position:0% +that work and then this is actually um + + + align:start position:0% +that work and then this is actually um +sort of storefront installation that's + + align:start position:0% +sort of storefront installation that's + + + align:start position:0% +sort of storefront installation that's +on the side of some of the clubs and um + + align:start position:0% +on the side of some of the clubs and um + + + align:start position:0% +on the side of some of the clubs and um +some of that the the the area is being + + align:start position:0% +some of that the the the area is being + + + align:start position:0% +some of that the the the area is being +redeveloped a jazz club Yoshi's which is + + align:start position:0% +redeveloped a jazz club Yoshi's which is + + + align:start position:0% +redeveloped a jazz club Yoshi's which is +in the East Bay is going to be moving + + align:start position:0% +in the East Bay is going to be moving + + + align:start position:0% +in the East Bay is going to be moving +across the street from where this is but + + align:start position:0% +across the street from where this is but + + + align:start position:0% +across the street from where this is but +it it's basically preservation District + + align:start position:0% +it it's basically preservation District + + + align:start position:0% +it it's basically preservation District +it's not really the it will not be the + + align:start position:0% +it's not really the it will not be the + + + align:start position:0% +it's not really the it will not be the +same and it won't be the same Community + + align:start position:0% +same and it won't be the same Community + + + align:start position:0% +same and it won't be the same Community +but I think the book and um is an + + align:start position:0% +but I think the book and um is an + + + align:start position:0% +but I think the book and um is an +attempt and the people who lived in the + + align:start position:0% +attempt and the people who lived in the + + + align:start position:0% +attempt and the people who lived in the +community say that the book is important + + align:start position:0% +community say that the book is important + + + align:start position:0% +community say that the book is important +to them because at least now that + + align:start position:0% +to them because at least now that + + + align:start position:0% +to them because at least now that +history has a public face + + align:start position:0% +history has a public face + + + align:start position:0% +history has a public face +so that was um that was me sort of + + align:start position:0% +so that was um that was me sort of + + + align:start position:0% +so that was um that was me sort of +manipulating and looking at and handling + + align:start position:0% +manipulating and looking at and handling + + + align:start position:0% +manipulating and looking at and handling +other people's photographs and + + align:start position:0% +other people's photographs and + + + align:start position:0% +other people's photographs and +manipulating with the idea of trying to + + align:start position:0% +manipulating with the idea of trying to + + + align:start position:0% +manipulating with the idea of trying to +bring them back to I think the the + + align:start position:0% +bring them back to I think the the + + + align:start position:0% +bring them back to I think the the +condition that I I think that the uh R + + align:start position:0% +condition that I I think that the uh R + + + align:start position:0% +condition that I I think that the uh R +photographers wanted so my own work um + + align:start position:0% +photographers wanted so my own work um + + + align:start position:0% +photographers wanted so my own work um +I'll show a little bit of the work uh + + align:start position:0% +I'll show a little bit of the work uh + + + align:start position:0% +I'll show a little bit of the work uh +the first kind of work I've done West + + align:start position:0% +the first kind of work I've done West + + + align:start position:0% +the first kind of work I've done West +Oakland was always a place that was + + align:start position:0% +Oakland was always a place that was + + + align:start position:0% +Oakland was always a place that was +interested in photographing and I'm very + + align:start position:0% +interested in photographing and I'm very + + + align:start position:0% +interested in photographing and I'm very +interested in markings some of you know + + align:start position:0% +interested in markings some of you know + + + align:start position:0% +interested in markings some of you know +Walker Evans um you'll see uh sort of + + align:start position:0% +Walker Evans um you'll see uh sort of + + + align:start position:0% +Walker Evans um you'll see uh sort of +evidence of my interest in kind of signs + + align:start position:0% +evidence of my interest in kind of signs + + + align:start position:0% +evidence of my interest in kind of signs +and what they mean and then I'm also + + align:start position:0% +and what they mean and then I'm also + + + align:start position:0% +and what they mean and then I'm also +interested in kind of symbolic so I + + align:start position:0% +interested in kind of symbolic so I + + + align:start position:0% +interested in kind of symbolic so I +thought that this I was told that this + + align:start position:0% +thought that this I was told that this + + + align:start position:0% +thought that this I was told that this +Ghost Town meant that this was a crack + + align:start position:0% +Ghost Town meant that this was a crack + + + align:start position:0% +Ghost Town meant that this was a crack +house but it turns out this community + + align:start position:0% +house but it turns out this community + + + align:start position:0% +house but it turns out this community +which is about a 20 block area in West + + align:start position:0% +which is about a 20 block area in West + + + align:start position:0% +which is about a 20 block area in West +Oakland calls itself ghost town and I've + + align:start position:0% +Oakland calls itself ghost town and I've + + + align:start position:0% +Oakland calls itself ghost town and I've +seen in um uh people sell t-shirts it's + + align:start position:0% +seen in um uh people sell t-shirts it's + + + align:start position:0% +seen in um uh people sell t-shirts it's +sort of like a sense of identity this is + + align:start position:0% +sort of like a sense of identity this is + + + align:start position:0% +sort of like a sense of identity this is +um uh can you read the text yeah um I + + align:start position:0% +um uh can you read the text yeah um I + + + align:start position:0% +um uh can you read the text yeah um I +sort of asked people there was a a + + align:start position:0% +sort of asked people there was a a + + + align:start position:0% +sort of asked people there was a a +Palestinian + + align:start position:0% +Palestinian + + + align:start position:0% +Palestinian +uh Market at the end of this block and I + + align:start position:0% +uh Market at the end of this block and I + + + align:start position:0% +uh Market at the end of this block and I +asked them about this signage and they + + align:start position:0% +asked them about this signage and they + + + align:start position:0% +asked them about this signage and they +either didn't want to talk about it and + + align:start position:0% +either didn't want to talk about it and + + + align:start position:0% +either didn't want to talk about it and +I asked people in the street but is + + align:start position:0% +I asked people in the street but is + + + align:start position:0% +I asked people in the street but is +obviously um interesting and sort of + + align:start position:0% +obviously um interesting and sort of + + + align:start position:0% +obviously um interesting and sort of +reflective of changing demographics in + + align:start position:0% +reflective of changing demographics in + + + align:start position:0% +reflective of changing demographics in +this particular neighborhood then here's + + align:start position:0% +this particular neighborhood then here's + + + align:start position:0% +this particular neighborhood then here's +basically uh a kind of more conscious + + align:start position:0% +basically uh a kind of more conscious + + + align:start position:0% +basically uh a kind of more conscious +marking of a nightclub facade in West + + align:start position:0% +marking of a nightclub facade in West + + + align:start position:0% +marking of a nightclub facade in West +Oakland and I love this is probably one + + align:start position:0% +Oakland and I love this is probably one + + + align:start position:0% +Oakland and I love this is probably one +of the first pictures I took when I + + align:start position:0% +of the first pictures I took when I + + + align:start position:0% +of the first pictures I took when I +decided to become a photographer and + + align:start position:0% +decided to become a photographer and + + + align:start position:0% +decided to become a photographer and +this is uh I I think really hand painted + + align:start position:0% +this is uh I I think really hand painted + + + align:start position:0% +this is uh I I think really hand painted +and very reminiscent of what I've seen + + align:start position:0% +and very reminiscent of what I've seen + + + align:start position:0% +and very reminiscent of what I've seen +in rural in Louisiana and actually right + + align:start position:0% +in rural in Louisiana and actually right + + + align:start position:0% +in rural in Louisiana and actually right +after I took the picture of the sign + + align:start position:0% +after I took the picture of the sign + + + align:start position:0% +after I took the picture of the sign +disappeared and I was told later when I + + align:start position:0% +disappeared and I was told later when I + + + align:start position:0% +disappeared and I was told later when I +had to show at the Oakland Museum that + + align:start position:0% +had to show at the Oakland Museum that + + + align:start position:0% +had to show at the Oakland Museum that +um the house was sold not long after I + + align:start position:0% +um the house was sold not long after I + + + align:start position:0% +um the house was sold not long after I +took it but it basically someone + + align:start position:0% +took it but it basically someone + + + align:start position:0% +took it but it basically someone +probably came in the 40s and 50s uh had + + align:start position:0% +probably came in the 40s and 50s uh had + + + align:start position:0% +probably came in the 40s and 50s uh had +chickens in the backyard and just like + + align:start position:0% +chickens in the backyard and just like + + + align:start position:0% +chickens in the backyard and just like +they had done in Texas Louisiana you + + align:start position:0% +they had done in Texas Louisiana you + + + align:start position:0% +they had done in Texas Louisiana you +could go get fresh + + align:start position:0% + + + + align:start position:0% + +poultry um this is uh some people have + + align:start position:0% +poultry um this is uh some people have + + + align:start position:0% +poultry um this is uh some people have +asked me about this picture U some + + align:start position:0% +asked me about this picture U some + + + align:start position:0% +asked me about this picture U some +people in interpret as someone + + align:start position:0% +people in interpret as someone + + + align:start position:0% +people in interpret as someone +incarcerated sort of behind um uh walls + + align:start position:0% +incarcerated sort of behind um uh walls + + + align:start position:0% +incarcerated sort of behind um uh walls +um and they I've been a number of other + + align:start position:0% +um and they I've been a number of other + + + align:start position:0% +um and they I've been a number of other +interpretations the other thing is this + + align:start position:0% +interpretations the other thing is this + + + align:start position:0% +interpretations the other thing is this +was at one time 512 which I thought is + + align:start position:0% +was at one time 512 which I thought is + + + align:start position:0% +was at one time 512 which I thought is +interesting I I don't know if you can + + align:start position:0% +interesting I I don't know if you can + + + align:start position:0% +interesting I I don't know if you can +read it um but it's basically uh + + align:start position:0% +read it um but it's basically uh + + + align:start position:0% +read it um but it's basically uh +probably retail space that someone's + + align:start position:0% +probably retail space that someone's + + + align:start position:0% +probably retail space that someone's +using now to live in and they put up + + align:start position:0% +using now to live in and they put up + + + align:start position:0% +using now to live in and they put up +this Photograph to for both privacy and + + align:start position:0% +this Photograph to for both privacy and + + + align:start position:0% +this Photograph to for both privacy and +as kind of reflection here's a converted + + align:start position:0% +as kind of reflection here's a converted + + + align:start position:0% +as kind of reflection here's a converted +storefront church and this again + + align:start position:0% +storefront church and this again + + + align:start position:0% +storefront church and this again +reminded me of the South um this this + + align:start position:0% +reminded me of the South um this this + + + align:start position:0% +reminded me of the South um this this +church has since and this building has + + align:start position:0% +church has since and this building has + + + align:start position:0% +church has since and this building has +since uh uh had other uses this picture + + align:start position:0% +since uh uh had other uses this picture + + + align:start position:0% +since uh uh had other uses this picture +was taken in '93 there's always a lot of + + align:start position:0% +was taken in '93 there's always a lot of + + + align:start position:0% +was taken in '93 there's always a lot of +that um kind of uh change in terms of + + align:start position:0% +that um kind of uh change in terms of + + + align:start position:0% +that um kind of uh change in terms of +how things are used but this whole idea + + align:start position:0% +how things are used but this whole idea + + + align:start position:0% +how things are used but this whole idea +of impro improvising and how that gets + + align:start position:0% +of impro improvising and how that gets + + + align:start position:0% +of impro improvising and how that gets +reflected in the environment is really + + align:start position:0% +reflected in the environment is really + + + align:start position:0% +reflected in the environment is really +important to me this is a photograph + + align:start position:0% +important to me this is a photograph + + + align:start position:0% +important to me this is a photograph +that um led me to meet an spurn I heard + + align:start position:0% +that um led me to meet an spurn I heard + + + align:start position:0% +that um led me to meet an spurn I heard +that my friend Walter Hood who uh I've + + align:start position:0% +that my friend Walter Hood who uh I've + + + align:start position:0% +that my friend Walter Hood who uh I've +done some work was showing slides of + + align:start position:0% +done some work was showing slides of + + + align:start position:0% +done some work was showing slides of +West Oakland and some things that he was + + align:start position:0% +West Oakland and some things that he was + + + align:start position:0% +West Oakland and some things that he was +doing and I guess either in the middle + + align:start position:0% +doing and I guess either in the middle + + + align:start position:0% +doing and I guess either in the middle +of his lecture or right afterwards she + + align:start position:0% +of his lecture or right afterwards she + + + align:start position:0% +of his lecture or right afterwards she +um yelled out for him to stop and say + + align:start position:0% +um yelled out for him to stop and say + + + align:start position:0% +um yelled out for him to stop and say +what's the story with that photograph + + align:start position:0% +what's the story with that photograph + + + align:start position:0% +what's the story with that photograph +and um which shows her incredibly good + + align:start position:0% +and um which shows her incredibly good + + + align:start position:0% +and um which shows her incredibly good +taste um but um what's interesting about + + align:start position:0% +taste um but um what's interesting about + + + align:start position:0% +taste um but um what's interesting about +it you know one of the rules is you + + align:start position:0% +it you know one of the rules is you + + + align:start position:0% +it you know one of the rules is you +shouldn't shoot in the middle of the day + + align:start position:0% +shouldn't shoot in the middle of the day + + + align:start position:0% +shouldn't shoot in the middle of the day +because um the angle of sun makes it + + align:start position:0% +because um the angle of sun makes it + + + align:start position:0% +because um the angle of sun makes it +harder to see people but of course uh I + + align:start position:0% +harder to see people but of course uh I + + + align:start position:0% +harder to see people but of course uh I +photograph when I can and I would not + + align:start position:0% +photograph when I can and I would not + + + align:start position:0% +photograph when I can and I would not +have been able to make this image + + align:start position:0% +have been able to make this image + + + align:start position:0% +have been able to make this image +without if it had not been in the middle + + align:start position:0% +without if it had not been in the middle + + + align:start position:0% +without if it had not been in the middle +of the day and the the couple things + + align:start position:0% +of the day and the the couple things + + + align:start position:0% +of the day and the the couple things +going on the Safeway cart is the basket + + align:start position:0% +going on the Safeway cart is the basket + + + align:start position:0% +going on the Safeway cart is the basket +the um you know what they're doing is + + align:start position:0% +the um you know what they're doing is + + + align:start position:0% +the um you know what they're doing is +played out on the + + align:start position:0% +played out on the + + + align:start position:0% +played out on the +street and um they didn't even they + + align:start position:0% +street and um they didn't even they + + + align:start position:0% +street and um they didn't even they +didn't even look up they were they were + + align:start position:0% +didn't even look up they were they were + + + align:start position:0% +didn't even look up they were they were +really into + + align:start position:0% +really into + + + align:start position:0% +really into +playing this was uh this uh domino game + + align:start position:0% +playing this was uh this uh domino game + + + align:start position:0% +playing this was uh this uh domino game +at the new Chicago new California Barber + + align:start position:0% +at the new Chicago new California Barber + + + align:start position:0% +at the new Chicago new California Barber +Shop had been going on almost + + align:start position:0% +Shop had been going on almost + + + align:start position:0% +Shop had been going on almost +continuously for about 20 years it's no + + align:start position:0% +continuously for about 20 years it's no + + + align:start position:0% +continuously for about 20 years it's no +longer in existence also and when when I + + align:start position:0% +longer in existence also and when when I + + + align:start position:0% +longer in existence also and when when I +photographed I photographed probably + + align:start position:0% +photographed I photographed probably + + + align:start position:0% +photographed I photographed probably +maybe over the course of a week and when + + align:start position:0% +maybe over the course of a week and when + + + align:start position:0% +maybe over the course of a week and when +I first saw this picture I really didn't + + align:start position:0% +I first saw this picture I really didn't + + + align:start position:0% +I first saw this picture I really didn't +like it compositionally but this is + + align:start position:0% +like it compositionally but this is + + + align:start position:0% +like it compositionally but this is +really the photograph the photograph is + + align:start position:0% +really the photograph the photograph is + + + align:start position:0% +really the photograph the photograph is +about their hands and how their hands + + align:start position:0% +about their hands and how their hands + + + align:start position:0% +about their hands and how their hands +kind of represent the kind of community + + align:start position:0% +kind of represent the kind of community + + + align:start position:0% +kind of represent the kind of community +and communion that they have plus I + + align:start position:0% +and communion that they have plus I + + + align:start position:0% +and communion that they have plus I +think he had a good hand so then right + + align:start position:0% +think he had a good hand so then right + + + align:start position:0% +think he had a good hand so then right +next door was this guy with a raccoon on + + align:start position:0% +next door was this guy with a raccoon on + + + align:start position:0% +next door was this guy with a raccoon on +a leash and in the barber shop they were + + align:start position:0% +a leash and in the barber shop they were + + + align:start position:0% +a leash and in the barber shop they were +taking bets as to who would win in a + + align:start position:0% +taking bets as to who would win in a + + + align:start position:0% +taking bets as to who would win in a +fight between a pitbull and the raccoon + + align:start position:0% +fight between a pitbull and the raccoon + + + align:start position:0% +fight between a pitbull and the raccoon +and I think I put my money on the + + align:start position:0% +and I think I put my money on the + + + align:start position:0% +and I think I put my money on the +Raccoon although this raccoon had + + align:start position:0% +Raccoon although this raccoon had + + + align:start position:0% +Raccoon although this raccoon had +actually been caught as a a what's a + + align:start position:0% +actually been caught as a a what's a + + + align:start position:0% +actually been caught as a a what's a +young raccoon a pup and um was was uh + + align:start position:0% +young raccoon a pup and um was was uh + + + align:start position:0% +young raccoon a pup and um was was uh +trained and I know when I used to live + + align:start position:0% +trained and I know when I used to live + + + align:start position:0% +trained and I know when I used to live +in Ren County raccoons would come in to + + align:start position:0% +in Ren County raccoons would come in to + + + align:start position:0% +in Ren County raccoons would come in to +my house through the window go into the + + align:start position:0% +my house through the window go into the + + + align:start position:0% +my house through the window go into the +kitchen open the the counter take the + + align:start position:0% +kitchen open the the counter take the + + + align:start position:0% +kitchen open the the counter take the +lid off the K cat kibble take their fill + + align:start position:0% +lid off the K cat kibble take their fill + + + align:start position:0% +lid off the K cat kibble take their fill +and put the lid back and then leave and + + align:start position:0% +and put the lid back and then leave and + + + align:start position:0% +and put the lid back and then leave and +did that regularly so I'm not sure I was + + align:start position:0% +did that regularly so I'm not sure I was + + + align:start position:0% +did that regularly so I'm not sure I was +talking earlier about the whole notion + + align:start position:0% +talking earlier about the whole notion + + + align:start position:0% +talking earlier about the whole notion +of um how do you photograph strangers + + align:start position:0% +of um how do you photograph strangers + + + align:start position:0% +of um how do you photograph strangers +and I think this Photograph sort of uh + + align:start position:0% +and I think this Photograph sort of uh + + + align:start position:0% +and I think this Photograph sort of uh +is interesting that I asked her if I + + align:start position:0% +is interesting that I asked her if I + + + align:start position:0% +is interesting that I asked her if I +could photograph this is actually in + + align:start position:0% +could photograph this is actually in + + + align:start position:0% +could photograph this is actually in +East Oakland and I think this Photograph + + align:start position:0% +East Oakland and I think this Photograph + + + align:start position:0% +East Oakland and I think this Photograph +I think she's looking at me much more + + align:start position:0% +I think she's looking at me much more + + + align:start position:0% +I think she's looking at me much more +intently than I'm looking at her which I + + align:start position:0% +intently than I'm looking at her which I + + + align:start position:0% +intently than I'm looking at her which I +think it's the + + align:start position:0% +think it's the + + + align:start position:0% +think it's the +photograph so I was very interested in + + align:start position:0% +photograph so I was very interested in + + + align:start position:0% +photograph so I was very interested in +people would tell stories of arriving in + + align:start position:0% +people would tell stories of arriving in + + + align:start position:0% +people would tell stories of arriving in +West Oakland in 1943 with $10 in their + + align:start position:0% +West Oakland in 1943 with $10 in their + + + align:start position:0% +West Oakland in 1943 with $10 in their +pocket and how they had raised a family + + align:start position:0% +pocket and how they had raised a family + + + align:start position:0% +pocket and how they had raised a family +you know two or three generation + + align:start position:0% +you know two or three generation + + + align:start position:0% +you know two or three generation +and there's a really beautiful um old uh + + align:start position:0% +and there's a really beautiful um old uh + + + align:start position:0% +and there's a really beautiful um old uh +uh railroad station which is closed + + align:start position:0% +uh railroad station which is closed + + + align:start position:0% +uh railroad station which is closed +because of seismic conditions and so + + align:start position:0% +because of seismic conditions and so + + + align:start position:0% +because of seismic conditions and so +there's a new one that uh is in Jack + + align:start position:0% +there's a new one that uh is in Jack + + + align:start position:0% +there's a new one that uh is in Jack +London Square and I was interested in + + align:start position:0% +London Square and I was interested in + + + align:start position:0% +London Square and I was interested in +photographing it and so I went one day + + align:start position:0% +photographing it and so I went one day + + + align:start position:0% +photographing it and so I went one day +and there was a guy waiting in a a + + align:start position:0% +and there was a guy waiting in a a + + + align:start position:0% +and there was a guy waiting in a a +Cadillac with these really beautiful + + align:start position:0% +Cadillac with these really beautiful + + + align:start position:0% +Cadillac with these really beautiful +cowboy boots and like a fool I said + + align:start position:0% +cowboy boots and like a fool I said + + + align:start position:0% +cowboy boots and like a fool I said +could you move cuz I want to photograph + + align:start position:0% +could you move cuz I want to photograph + + + align:start position:0% +could you move cuz I want to photograph +the building you know I immediately + + align:start position:0% +the building you know I immediately + + + align:start position:0% +the building you know I immediately +regretted it and so um I got another + + align:start position:0% +regretted it and so um I got another + + + align:start position:0% +regretted it and so um I got another +chance I went back and here's a woman + + align:start position:0% +chance I went back and here's a woman + + + align:start position:0% +chance I went back and here's a woman +who just come from Stockton dressed up + + align:start position:0% +who just come from Stockton dressed up + + + align:start position:0% +who just come from Stockton dressed up +for her daughter's wedding and so I sort + + align:start position:0% +for her daughter's wedding and so I sort + + + align:start position:0% +for her daughter's wedding and so I sort +of saw that this was taken in '97 but I + + align:start position:0% +of saw that this was taken in '97 but I + + + align:start position:0% +of saw that this was taken in '97 but I +saw that as kind of being indication of + + align:start position:0% +saw that as kind of being indication of + + + align:start position:0% +saw that as kind of being indication of +that idea of transference and the kind + + align:start position:0% +that idea of transference and the kind + + + align:start position:0% +that idea of transference and the kind +of indicating these stories I heard um + + align:start position:0% +of indicating these stories I heard um + + + align:start position:0% +of indicating these stories I heard um +and I love that the shopping cart in the + + align:start position:0% +and I love that the shopping cart in the + + + align:start position:0% +and I love that the shopping cart in the +ghetto is a is the SUV of the ghetto and + + align:start position:0% +ghetto is a is the SUV of the ghetto and + + + align:start position:0% +ghetto is a is the SUV of the ghetto and +absolutely is a convenience uh a means + + align:start position:0% +absolutely is a convenience uh a means + + + align:start position:0% +absolutely is a convenience uh a means +for transfering uh in some cases there's + + align:start position:0% +for transfering uh in some cases there's + + + align:start position:0% +for transfering uh in some cases there's +like lines of them it's also uh + + align:start position:0% +like lines of them it's also uh + + + align:start position:0% +like lines of them it's also uh +important in the economy terms of + + align:start position:0% +important in the economy terms of + + + align:start position:0% +important in the economy terms of +recycling so um uh so that's sort of + + align:start position:0% +recycling so um uh so that's sort of + + + align:start position:0% +recycling so um uh so that's sort of +West Oakland and here's a photograph + + align:start position:0% +West Oakland and here's a photograph + + + align:start position:0% +West Oakland and here's a photograph +taken in hiana Florida um I sort of read + + align:start position:0% +taken in hiana Florida um I sort of read + + + align:start position:0% +taken in hiana Florida um I sort of read +about the whole notion West African + + align:start position:0% +about the whole notion West African + + + align:start position:0% +about the whole notion West African +notion of the swep swept clean yard + + align:start position:0% +notion of the swep swept clean yard + + + align:start position:0% +notion of the swep swept clean yard +which is all over the South um so here + + align:start position:0% +which is all over the South um so here + + + align:start position:0% +which is all over the South um so here +was an example this is a swept clean + + align:start position:0% +was an example this is a swept clean + + + align:start position:0% +was an example this is a swept clean +yard with a satellite + + align:start position:0% +yard with a satellite + + + align:start position:0% +yard with a satellite +dish um I went to Beal Street and saw + + align:start position:0% +dish um I went to Beal Street and saw + + + align:start position:0% +dish um I went to Beal Street and saw +this peeling mural some people think + + align:start position:0% +this peeling mural some people think + + + align:start position:0% +this peeling mural some people think +that's Bessie Smith some think it's it's + + align:start position:0% +that's Bessie Smith some think it's it's + + + align:start position:0% +that's Bessie Smith some think it's it's +Billy Holiday um couldn't find it when I + + align:start position:0% +Billy Holiday um couldn't find it when I + + + align:start position:0% +Billy Holiday um couldn't find it when I +was there a couple of months ago so it + + align:start position:0% +was there a couple of months ago so it + + + align:start position:0% +was there a couple of months ago so it +was gone uh Bradford marcelus used it on + + align:start position:0% +was gone uh Bradford marcelus used it on + + + align:start position:0% +was gone uh Bradford marcelus used it on +the cover of one of his albums but I + + align:start position:0% +the cover of one of his albums but I + + + align:start position:0% +the cover of one of his albums but I +sort of saw it as symbolic sort of B + + align:start position:0% +sort of saw it as symbolic sort of B + + + align:start position:0% +sort of saw it as symbolic sort of B +Street the same thing happened it was + + align:start position:0% +Street the same thing happened it was + + + align:start position:0% +Street the same thing happened it was +about to be um it was a thriving + + align:start position:0% +about to be um it was a thriving + + + align:start position:0% +about to be um it was a thriving +African-American Community it was about + + align:start position:0% +African-American Community it was about + + + align:start position:0% +African-American Community it was about +to be um destroyed and it's basically + + align:start position:0% +to be um destroyed and it's basically + + + align:start position:0% +to be um destroyed and it's basically +now a tourist area so the culture was um + + align:start position:0% +now a tourist area so the culture was um + + + align:start position:0% +now a tourist area so the culture was um +the means for it to survive but it's not + + align:start position:0% +the means for it to survive but it's not + + + align:start position:0% +the means for it to survive but it's not +it it had to take another reiteration + + align:start position:0% +it it had to take another reiteration + + + align:start position:0% +it it had to take another reiteration +I'm really interested in what's going to + + align:start position:0% +I'm really interested in what's going to + + + align:start position:0% +I'm really interested in what's going to +happen in New Orleans and we'll talk + + align:start position:0% +happen in New Orleans and we'll talk + + + align:start position:0% +happen in New Orleans and we'll talk +more about that um this is Tula + + align:start position:0% +more about that um this is Tula + + + align:start position:0% +more about that um this is Tula +Louisiana um kind of a bayou uh light + + align:start position:0% +Louisiana um kind of a bayou uh light + + + align:start position:0% +Louisiana um kind of a bayou uh light +tree this is in the Third Ward in + + align:start position:0% +tree this is in the Third Ward in + + + align:start position:0% +tree this is in the Third Ward in +Houston I um was uh worked with a number + + align:start position:0% +Houston I um was uh worked with a number + + + align:start position:0% +Houston I um was uh worked with a number +of uh uh Architects um in at that that + + align:start position:0% +of uh uh Architects um in at that that + + + align:start position:0% +of uh uh Architects um in at that that +time in rice they had a conference on + + align:start position:0% +time in rice they had a conference on + + + align:start position:0% +time in rice they had a conference on +shotgun houses and the project Rous + + align:start position:0% +shotgun houses and the project Rous + + + align:start position:0% +shotgun houses and the project Rous +which is in the the Third Ward is um + + align:start position:0% +which is in the the Third Ward is um + + + align:start position:0% +which is in the the Third Ward is um +series of of shotgun houses that were + + align:start position:0% +series of of shotgun houses that were + + + align:start position:0% +series of of shotgun houses that were +sort of reconfigured some of you may + + align:start position:0% +sort of reconfigured some of you may + + + align:start position:0% +sort of reconfigured some of you may +know about it and artists come and do in + + align:start position:0% +know about it and artists come and do in + + + align:start position:0% +know about it and artists come and do in +do residencies and installation actually + + align:start position:0% +do residencies and installation actually + + + align:start position:0% +do residencies and installation actually +run by um uh unwed mothers who um sort + + align:start position:0% +run by um uh unwed mothers who um sort + + + align:start position:0% +run by um uh unwed mothers who um sort +of administer it but the neighborhood in + + align:start position:0% +of administer it but the neighborhood in + + + align:start position:0% +of administer it but the neighborhood in +Houston was very interesting to me and + + align:start position:0% +Houston was very interesting to me and + + + align:start position:0% +Houston was very interesting to me and +here's you know that sort of ongoing + + align:start position:0% +here's you know that sort of ongoing + + + align:start position:0% +here's you know that sort of ongoing +I've seen domino games in Kingston + + align:start position:0% +I've seen domino games in Kingston + + + align:start position:0% +I've seen domino games in Kingston +Jamaica all over the south in carem um + + align:start position:0% +Jamaica all over the south in carem um + + + align:start position:0% +Jamaica all over the south in carem um +again I'm always interested in the sort + + align:start position:0% +again I'm always interested in the sort + + + align:start position:0% +again I'm always interested in the sort +of stories that get told on the + + align:start position:0% +of stories that get told on the + + + align:start position:0% +of stories that get told on the +street um the Third Ward is the home of + + align:start position:0% +street um the Third Ward is the home of + + + align:start position:0% +street um the Third Ward is the home of +uh um Barbara Jordan and uh Mickey + + align:start position:0% +uh um Barbara Jordan and uh Mickey + + + align:start position:0% +uh um Barbara Jordan and uh Mickey +Leland and lightning Hopkins a lot of + + align:start position:0% +Leland and lightning Hopkins a lot of + + + align:start position:0% +Leland and lightning Hopkins a lot of +people the third W come from the third W + + align:start position:0% +people the third W come from the third W + + + align:start position:0% +people the third W come from the third W +this project Ro house in the + + align:start position:0% + + + + align:start position:0% + +background and this sort of interesting + + align:start position:0% +background and this sort of interesting + + + align:start position:0% +background and this sort of interesting +story in the + + align:start position:0% +story in the + + + align:start position:0% +story in the +foreground so this is sort of the + + align:start position:0% +foreground so this is sort of the + + + align:start position:0% +foreground so this is sort of the +courtyard of of um project Rouse so + + align:start position:0% +courtyard of of um project Rouse so + + + align:start position:0% +courtyard of of um project Rouse so +project rowhouse in some ways was kind + + align:start position:0% +project rowhouse in some ways was kind + + + align:start position:0% +project rowhouse in some ways was kind +of um formalized but the shotgun house + + align:start position:0% +of um formalized but the shotgun house + + + align:start position:0% +of um formalized but the shotgun house +is very interesting uh it's like the + + align:start position:0% +is very interesting uh it's like the + + + align:start position:0% +is very interesting uh it's like the +perfect design pre uh air conditioner + + align:start position:0% +perfect design pre uh air conditioner + + + align:start position:0% +perfect design pre uh air conditioner +because of the Cross ventilation High + + align:start position:0% +because of the Cross ventilation High + + + align:start position:0% +because of the Cross ventilation High +ceilings and um I know uh I've got the + + align:start position:0% +ceilings and um I know uh I've got the + + + align:start position:0% +ceilings and um I know uh I've got the +chance to stay with friends of mine in + + align:start position:0% +chance to stay with friends of mine in + + + align:start position:0% +chance to stay with friends of mine in +Baton Rouge it's actually a really nice + + align:start position:0% +Baton Rouge it's actually a really nice + + + align:start position:0% +Baton Rouge it's actually a really nice +kind of uh house we can't use them in + + align:start position:0% +kind of uh house we can't use them in + + + align:start position:0% +kind of uh house we can't use them in +California because you can just put them + + align:start position:0% +California because you can just put them + + + align:start position:0% +California because you can just put them +on concrete blocks but that won't work + + align:start position:0% +on concrete blocks but that won't work + + + align:start position:0% +on concrete blocks but that won't work +for seismic so um I uh love going to New + + align:start position:0% +for seismic so um I uh love going to New + + + align:start position:0% +for seismic so um I uh love going to New +York I'm really regret not being able to + + align:start position:0% +York I'm really regret not being able to + + + align:start position:0% +York I'm really regret not being able to +go this trip um but here the you'll sort + + align:start position:0% +go this trip um but here the you'll sort + + + align:start position:0% +go this trip um but here the you'll sort +of see kind of similar kind of + + align:start position:0% +of see kind of similar kind of + + + align:start position:0% +of see kind of similar kind of +references I'm very interested Ed in + + align:start position:0% +references I'm very interested Ed in + + + align:start position:0% +references I'm very interested Ed in +especially how the sort of um the + + align:start position:0% +especially how the sort of um the + + + align:start position:0% +especially how the sort of um the +African-American church which I have + + align:start position:0% +African-American church which I have + + + align:start position:0% +African-American church which I have +some problems with but but also which I + + align:start position:0% +some problems with but but also which I + + + align:start position:0% +some problems with but but also which I +think is incredible thank God for it + + align:start position:0% +think is incredible thank God for it + + + align:start position:0% +think is incredible thank God for it +because it it's a source of a lot of my + + align:start position:0% +because it it's a source of a lot of my + + + align:start position:0% +because it it's a source of a lot of my +photography I have some things I really + + align:start position:0% +photography I have some things I really + + + align:start position:0% +photography I have some things I really +admire about it also um but you can kind + + align:start position:0% +admire about it also um but you can kind + + + align:start position:0% +admire about it also um but you can kind +of see this referencing the thing I this + + align:start position:0% +of see this referencing the thing I this + + + align:start position:0% +of see this referencing the thing I this +is in Harlem uh this is actually a + + align:start position:0% +is in Harlem uh this is actually a + + + align:start position:0% +is in Harlem uh this is actually a +Haitian uh Church + + align:start position:0% +Haitian uh Church + + + align:start position:0% +Haitian uh Church +um and I I just love that kind of + + align:start position:0% +um and I I just love that kind of + + + align:start position:0% +um and I I just love that kind of +evidence of hand and expression a + + align:start position:0% +evidence of hand and expression a + + + align:start position:0% +evidence of hand and expression a +collective expression of Faith as shown + + align:start position:0% +collective expression of Faith as shown + + + align:start position:0% +collective expression of Faith as shown +in a visual sense now I may have it + + align:start position:0% +in a visual sense now I may have it + + + align:start position:0% +in a visual sense now I may have it +wrong I think this is 127th Street in + + align:start position:0% +wrong I think this is 127th Street in + + + align:start position:0% +wrong I think this is 127th Street in +Harlem I believe it that was designed by + + align:start position:0% +Harlem I believe it that was designed by + + + align:start position:0% +Harlem I believe it that was designed by +the asers but looks like Southern + + align:start position:0% +the asers but looks like Southern + + + align:start position:0% +the asers but looks like Southern +architecture to me so I I actually love + + align:start position:0% +architecture to me so I I actually love + + + align:start position:0% +architecture to me so I I actually love +um kind of this little one block with uh + + align:start position:0% +um kind of this little one block with uh + + + align:start position:0% +um kind of this little one block with uh +kind of scale and um architecture which + + align:start position:0% +kind of scale and um architecture which + + + align:start position:0% +kind of scale and um architecture which +seems much different than New York um I + + align:start position:0% +seems much different than New York um I + + + align:start position:0% +seems much different than New York um I +was scheduled to do a residency in New + + align:start position:0% +was scheduled to do a residency in New + + + align:start position:0% +was scheduled to do a residency in New +Orleans um actually this during the + + align:start position:0% +Orleans um actually this during the + + + align:start position:0% +Orleans um actually this during the +summer and I was working on my book so + + align:start position:0% +summer and I was working on my book so + + + align:start position:0% +summer and I was working on my book so +it was delayed and then all of a sudden + + align:start position:0% +it was delayed and then all of a sudden + + + align:start position:0% +it was delayed and then all of a sudden +Katrina hit so I was not able to go so I + + align:start position:0% +Katrina hit so I was not able to go so I + + + align:start position:0% +Katrina hit so I was not able to go so I +went um I went to New York um and stay + + align:start position:0% +went um I went to New York um and stay + + + align:start position:0% +went um I went to New York um and stay +actually stayed in Brooklyn and + + align:start position:0% +actually stayed in Brooklyn and + + + align:start position:0% +actually stayed in Brooklyn and +photographed a sort of some examples of + + align:start position:0% +photographed a sort of some examples of + + + align:start position:0% +photographed a sort of some examples of +both gentrification and people fighting + + align:start position:0% +both gentrification and people fighting + + + align:start position:0% +both gentrification and people fighting +it um I would spent a little time in + + align:start position:0% +it um I would spent a little time in + + + align:start position:0% +it um I would spent a little time in +Washington and then I went to Chicago + + align:start position:0% +Washington and then I went to Chicago + + + align:start position:0% +Washington and then I went to Chicago +where um a friend of mine who I remember + + align:start position:0% +where um a friend of mine who I remember + + + align:start position:0% +where um a friend of mine who I remember +as being in the Black Panthers is now an + + align:start position:0% +as being in the Black Panthers is now an + + + align:start position:0% +as being in the Black Panthers is now an +Alderman and was organized ing um her + + align:start position:0% +Alderman and was organized ing um her + + + align:start position:0% +Alderman and was organized ing um her +district and uh just north of uh Wrigley + + align:start position:0% +district and uh just north of uh Wrigley + + + align:start position:0% +district and uh just north of uh Wrigley +Field on the North side and instead of + + align:start position:0% +Field on the North side and instead of + + + align:start position:0% +Field on the North side and instead of +the recurring pattern where a lot of + + align:start position:0% +the recurring pattern where a lot of + + + align:start position:0% +the recurring pattern where a lot of +people were being displaced she was um + + align:start position:0% +people were being displaced she was um + + + align:start position:0% +people were being displaced she was um +um sort of having community-based + + align:start position:0% +um sort of having community-based + + + align:start position:0% +um sort of having community-based +Redevelopment and she had seen the + + align:start position:0% +Redevelopment and she had seen the + + + align:start position:0% +Redevelopment and she had seen the +Filmore um project and was interested in + + align:start position:0% +Filmore um project and was interested in + + + align:start position:0% +Filmore um project and was interested in +in me talking to them about doing public + + align:start position:0% +in me talking to them about doing public + + + align:start position:0% +in me talking to them about doing public +art and kind of expressions of history + + align:start position:0% +art and kind of expressions of history + + + align:start position:0% +art and kind of expressions of history +in the the sort of area that they were + + align:start position:0% +in the the sort of area that they were + + + align:start position:0% +in the the sort of area that they were +communicating and I hadn't been to + + align:start position:0% +communicating and I hadn't been to + + + align:start position:0% +communicating and I hadn't been to +Chicago in 30 years and um got a chance + + align:start position:0% +Chicago in 30 years and um got a chance + + + align:start position:0% +Chicago in 30 years and um got a chance +to go to Cabrini Green um which is just + + align:start position:0% +to go to Cabrini Green um which is just + + + align:start position:0% +to go to Cabrini Green um which is just +barely left but um was kind of wandering + + align:start position:0% +barely left but um was kind of wandering + + + align:start position:0% +barely left but um was kind of wandering +around and saw some people with video + + align:start position:0% +around and saw some people with video + + + align:start position:0% +around and saw some people with video +and there was a group that was + + align:start position:0% +and there was a group that was + + + align:start position:0% +and there was a group that was +interviewing people who were to trying + + align:start position:0% +interviewing people who were to trying + + + align:start position:0% +interviewing people who were to trying +to prevent them from being displaced + + align:start position:0% +to prevent them from being displaced + + + align:start position:0% +to prevent them from being displaced +because a lot of people have been + + align:start position:0% +because a lot of people have been + + + align:start position:0% +because a lot of people have been +displaced and they were going to + + align:start position:0% +displaced and they were going to + + + align:start position:0% +displaced and they were going to +actually go to the UN with with + + align:start position:0% +actually go to the UN with with + + + align:start position:0% +actually go to the UN with with +interviews so I had seen photographs of + + align:start position:0% +interviews so I had seen photographs of + + + align:start position:0% +interviews so I had seen photographs of +it I think the good times was was based + + align:start position:0% +it I think the good times was was based + + + align:start position:0% +it I think the good times was was based +in Cabrini Green and I've been hearing + + align:start position:0% +in Cabrini Green and I've been hearing + + + align:start position:0% +in Cabrini Green and I've been hearing +about it for years um and there's this + + align:start position:0% +about it for years um and there's this + + + align:start position:0% +about it for years um and there's this +whole thing about these exterior um + + align:start position:0% +whole thing about these exterior um + + + align:start position:0% +whole thing about these exterior um +corridors and like 3T Square elevators + + align:start position:0% +corridors and like 3T Square elevators + + + align:start position:0% +corridors and like 3T Square elevators +and incredible mass and I'd seen + + align:start position:0% +and incredible mass and I'd seen + + + align:start position:0% +and incredible mass and I'd seen +photographs of and I had to photograph + + align:start position:0% +photographs of and I had to photograph + + + align:start position:0% +photographs of and I had to photograph +it um it was very interesting + + align:start position:0% +it um it was very interesting + + + align:start position:0% +it um it was very interesting +um uh and this was sort of my attempt to + + align:start position:0% +um uh and this was sort of my attempt to + + + align:start position:0% +um uh and this was sort of my attempt to +get back to photographing after having + + align:start position:0% +get back to photographing after having + + + align:start position:0% +get back to photographing after having +been working on other projects and we + + align:start position:0% +been working on other projects and we + + + align:start position:0% +been working on other projects and we +were talking about it earlier I wasn't + + align:start position:0% +were talking about it earlier I wasn't + + + align:start position:0% +were talking about it earlier I wasn't +sure if I was still a photographer I had + + align:start position:0% +sure if I was still a photographer I had + + + align:start position:0% +sure if I was still a photographer I had +to kind of work my way back through it + + align:start position:0% + + + + align:start position:0% + +so uh from there I went to see my friend + + align:start position:0% +so uh from there I went to see my friend + + + align:start position:0% +so uh from there I went to see my friend +uh + + align:start position:0% +uh + + + align:start position:0% +uh +uh Laura Lawson who's a teaches + + align:start position:0% +uh Laura Lawson who's a teaches + + + align:start position:0% +uh Laura Lawson who's a teaches +landscape and who I worked on a book of + + align:start position:0% +landscape and who I worked on a book of + + + align:start position:0% +landscape and who I worked on a book of +Community Gardens with and she had been + + align:start position:0% +Community Gardens with and she had been + + + align:start position:0% +Community Gardens with and she had been +talking about East St Louis so she took + + align:start position:0% +talking about East St Louis so she took + + + align:start position:0% +talking about East St Louis so she took +me to East St Louis um this is a bridge + + align:start position:0% +me to East St Louis um this is a bridge + + + align:start position:0% +me to East St Louis um this is a bridge +that um I didn't you know I heard about + + align:start position:0% +that um I didn't you know I heard about + + + align:start position:0% +that um I didn't you know I heard about +least St Louis it's the home of Miles + + align:start position:0% +least St Louis it's the home of Miles + + + align:start position:0% +least St Louis it's the home of Miles +Davis is probably the source of one of + + align:start position:0% +Davis is probably the source of one of + + + align:start position:0% +Davis is probably the source of one of +the large the the most um the biggest + + align:start position:0% +the large the the most um the biggest + + + align:start position:0% +the large the the most um the biggest +race riots um in the country in the + + align:start position:0% +race riots um in the country in the + + + align:start position:0% +race riots um in the country in the +history of the country and there was a + + align:start position:0% +history of the country and there was a + + + align:start position:0% +history of the country and there was a +bridge where you could walk to St Louis + + align:start position:0% +bridge where you could walk to St Louis + + + align:start position:0% +bridge where you could walk to St Louis +that has been closed that's this has + + align:start position:0% +that has been closed that's this has + + + align:start position:0% +that has been closed that's this has +been closed I think for the last 50 + + align:start position:0% +been closed I think for the last 50 + + + align:start position:0% +been closed I think for the last 50 +years and this is sort of the yellow + + align:start position:0% +years and this is sort of the yellow + + + align:start position:0% +years and this is sort of the yellow +brick road where you can kind of see the + + align:start position:0% +brick road where you can kind of see the + + + align:start position:0% +brick road where you can kind of see the +archway from this bridge um that's sort + + align:start position:0% +archway from this bridge um that's sort + + + align:start position:0% +archway from this bridge um that's sort +of in uh + + align:start position:0% +of in uh + + + align:start position:0% +of in uh +disrepair um I was interested in this + + align:start position:0% +disrepair um I was interested in this + + + align:start position:0% +disrepair um I was interested in this +the the kind of results the Onyx Club + + align:start position:0% +the the kind of results the Onyx Club + + + align:start position:0% +the the kind of results the Onyx Club +there was a club Alabama which I know + + align:start position:0% +there was a club Alabama which I know + + + align:start position:0% +there was a club Alabama which I know +there was one in Central Avenue and it + + align:start position:0% +there was one in Central Avenue and it + + + align:start position:0% +there was one in Central Avenue and it +was also one in San Francisco that + + align:start position:0% +was also one in San Francisco that + + + align:start position:0% +was also one in San Francisco that +seemed to be recurring theme um so that + + align:start position:0% +seemed to be recurring theme um so that + + + align:start position:0% +seemed to be recurring theme um so that +was + + align:start position:0% +was + + + align:start position:0% +was +both interesting uh to me and both kind + + align:start position:0% +both interesting uh to me and both kind + + + align:start position:0% +both interesting uh to me and both kind +of places that I I'm going to go back + + align:start position:0% +of places that I I'm going to go back + + + align:start position:0% +of places that I I'm going to go back +and do some more work + + align:start position:0% +and do some more work + + + align:start position:0% +and do some more work +um um so I'm going to show you a little + + align:start position:0% +um um so I'm going to show you a little + + + align:start position:0% +um um so I'm going to show you a little +bit of a color work I've been kind of + + align:start position:0% +bit of a color work I've been kind of + + + align:start position:0% +bit of a color work I've been kind of +Shifting back and forth I got a dig well + + align:start position:0% +Shifting back and forth I got a dig well + + + align:start position:0% +Shifting back and forth I got a dig well +I got a um my I moved and gave up my + + align:start position:0% +I got a um my I moved and gave up my + + + align:start position:0% +I got a um my I moved and gave up my +dark room and then simultaneously got a + + align:start position:0% +dark room and then simultaneously got a + + + align:start position:0% +dark room and then simultaneously got a +job in Santa Cruz and wasn't sure if I + + align:start position:0% +job in Santa Cruz and wasn't sure if I + + + align:start position:0% +job in Santa Cruz and wasn't sure if I +was going to to be moving there I'm not + + align:start position:0% +was going to to be moving there I'm not + + + align:start position:0% +was going to to be moving there I'm not +um and uh sort of simultaneously to me + + align:start position:0% +um and uh sort of simultaneously to me + + + align:start position:0% +um and uh sort of simultaneously to me +working on the book I started doing + + align:start position:0% +working on the book I started doing + + + align:start position:0% +working on the book I started doing +output put digitally and started doing + + align:start position:0% +output put digitally and started doing + + + align:start position:0% +output put digitally and started doing +more color I didn't do I did some color + + align:start position:0% +more color I didn't do I did some color + + + align:start position:0% +more color I didn't do I did some color +and I printed color but because I didn't + + align:start position:0% +and I printed color but because I didn't + + + align:start position:0% +and I printed color but because I didn't +have access I um had and would really + + align:start position:0% +have access I um had and would really + + + align:start position:0% +have access I um had and would really +like black and white I started doing I I + + align:start position:0% +like black and white I started doing I I + + + align:start position:0% +like black and white I started doing I I +did color all along but I kind of + + align:start position:0% +did color all along but I kind of + + + align:start position:0% +did color all along but I kind of +started actualizing it this's another + + align:start position:0% +started actualizing it this's another + + + align:start position:0% +started actualizing it this's another +nightclub facade at East Oakland this is + + align:start position:0% +nightclub facade at East Oakland this is + + + align:start position:0% +nightclub facade at East Oakland this is +in Richmond a sort of a nicely um + + align:start position:0% +in Richmond a sort of a nicely um + + + align:start position:0% +in Richmond a sort of a nicely um +appointed + + align:start position:0% +appointed + + + align:start position:0% +appointed +Treehouse this is um also hian uh + + align:start position:0% +Treehouse this is um also hian uh + + + align:start position:0% +Treehouse this is um also hian uh +Florida Lower East Side in New York with + + align:start position:0% +Florida Lower East Side in New York with + + + align:start position:0% +Florida Lower East Side in New York with +basketballs Brooklyn very near where + + align:start position:0% +basketballs Brooklyn very near where + + + align:start position:0% +basketballs Brooklyn very near where +ebitz fille used to + + align:start position:0% +ebitz fille used to + + + align:start position:0% +ebitz fille used to +be uh Eatonville Florida home of zoril + + align:start position:0% +be uh Eatonville Florida home of zoril + + + align:start position:0% +be uh Eatonville Florida home of zoril +Hurston another uh Church in Richmond it + + align:start position:0% +Hurston another uh Church in Richmond it + + + align:start position:0% +Hurston another uh Church in Richmond it +looks very much like churches I see in + + align:start position:0% +looks very much like churches I see in + + + align:start position:0% +looks very much like churches I see in +the South so when I came back U I did + + align:start position:0% +the South so when I came back U I did + + + align:start position:0% +the South so when I came back U I did +get to New Orleans you'll see some of + + align:start position:0% +get to New Orleans you'll see some of + + + align:start position:0% +get to New Orleans you'll see some of +those later but when I came back I was + + align:start position:0% +those later but when I came back I was + + + align:start position:0% +those later but when I came back I was +commissioned to um uh work on uh a + + align:start position:0% +commissioned to um uh work on uh a + + + align:start position:0% +commissioned to um uh work on uh a +public art project in uh on Vermont + + align:start position:0% +public art project in uh on Vermont + + + align:start position:0% +public art project in uh on Vermont +Street in uh what is now called South + + align:start position:0% +Street in uh what is now called South + + + align:start position:0% +Street in uh what is now called South +Central Los Angeles but it but until uh + + align:start position:0% +Central Los Angeles but it but until uh + + + align:start position:0% +Central Los Angeles but it but until uh +prior to the Watts Riots was just + + align:start position:0% +prior to the Watts Riots was just + + + align:start position:0% +prior to the Watts Riots was just +Central Los Angeles and this is the + + align:start position:0% +Central Los Angeles and this is the + + + align:start position:0% +Central Los Angeles and this is the +first public um sort of county building + + align:start position:0% +first public um sort of county building + + + align:start position:0% +first public um sort of county building +in this neighborhood since the Rodney + + align:start position:0% +in this neighborhood since the Rodney + + + align:start position:0% +in this neighborhood since the Rodney +King riots basically sort of nothing's + + align:start position:0% +King riots basically sort of nothing's + + + align:start position:0% +King riots basically sort of nothing's +happened there were all these promises + + align:start position:0% +happened there were all these promises + + + align:start position:0% +happened there were all these promises +that were going to be made and the is + + align:start position:0% +that were going to be made and the is + + + align:start position:0% +that were going to be made and the is +privately developed and the developer + + align:start position:0% +privately developed and the developer + + + align:start position:0% +privately developed and the developer +who was a photo collector wanted to have + + align:start position:0% +who was a photo collector wanted to have + + + align:start position:0% +who was a photo collector wanted to have +photography and public art so he + + align:start position:0% +photography and public art so he + + + align:start position:0% +photography and public art so he +basically commiss missed six artists to + + align:start position:0% +basically commiss missed six artists to + + + align:start position:0% +basically commiss missed six artists to +um uh work for a month and then do a + + align:start position:0% +um uh work for a month and then do a + + + align:start position:0% +um uh work for a month and then do a +proposal and this was a neighborhood + + align:start position:0% +proposal and this was a neighborhood + + + align:start position:0% +proposal and this was a neighborhood +I've been looking for in La for like 30 + + align:start position:0% +I've been looking for in La for like 30 + + + align:start position:0% +I've been looking for in La for like 30 +years it's not it's not it's farther + + align:start position:0% +years it's not it's not it's farther + + + align:start position:0% +years it's not it's not it's farther +more Central than Compton and Watts it + + align:start position:0% +more Central than Compton and Watts it + + + align:start position:0% +more Central than Compton and Watts it +has a lot of storefront churches um it's + + align:start position:0% +has a lot of storefront churches um it's + + + align:start position:0% +has a lot of storefront churches um it's +half perhaps slightly more Hispanic it + + align:start position:0% +half perhaps slightly more Hispanic it + + + align:start position:0% +half perhaps slightly more Hispanic it +had all these kind of things that you + + align:start position:0% +had all these kind of things that you + + + align:start position:0% +had all these kind of things that you +can kind of see from my work I'm + + align:start position:0% +can kind of see from my work I'm + + + align:start position:0% +can kind of see from my work I'm +interested in and I love these converted + + align:start position:0% +interested in and I love these converted + + + align:start position:0% +interested in and I love these converted +buildings you know the the whole idea of + + align:start position:0% +buildings you know the the whole idea of + + + align:start position:0% +buildings you know the the whole idea of +the theater being used having different + + align:start position:0% +the theater being used having different + + + align:start position:0% +the theater being used having different +reiterations has been real interesting + + align:start position:0% +reiterations has been real interesting + + + align:start position:0% +reiterations has been real interesting +to me and again the kind of markings how + + align:start position:0% +to me and again the kind of markings how + + + align:start position:0% +to me and again the kind of markings how +how is both Faith + + align:start position:0% + + + + align:start position:0% + +expressed and the other thing I like + + align:start position:0% +expressed and the other thing I like + + + align:start position:0% +expressed and the other thing I like +about La is um if if I need to go + + align:start position:0% +about La is um if if I need to go + + + align:start position:0% +about La is um if if I need to go +someplace really different from the Bay + + align:start position:0% +someplace really different from the Bay + + + align:start position:0% +someplace really different from the Bay +Area I can go to La and feel like I'm + + align:start position:0% +Area I can go to La and feel like I'm + + + align:start position:0% +Area I can go to La and feel like I'm +going to Nepal because the light is + + align:start position:0% +going to Nepal because the light is + + + align:start position:0% +going to Nepal because the light is +different the light is really different + + align:start position:0% +different the light is really different + + + align:start position:0% +different the light is really different +I think something happened I think it's + + align:start position:0% +I think something happened I think it's + + + align:start position:0% +I think something happened I think it's +really is a different Zone the things + + align:start position:0% +really is a different Zone the things + + + align:start position:0% +really is a different Zone the things +that people talk about are different the + + align:start position:0% +that people talk about are different the + + + align:start position:0% +that people talk about are different the +colors they wear are different the cars + + align:start position:0% +colors they wear are different the cars + + + align:start position:0% +colors they wear are different the cars +and their interest in cars are different + + align:start position:0% +and their interest in cars are different + + + align:start position:0% +and their interest in cars are different +and and I always find it really + + align:start position:0% + + + + align:start position:0% + +refreshing so again uh I love the fact + + align:start position:0% +refreshing so again uh I love the fact + + + align:start position:0% +refreshing so again uh I love the fact +that people's hearts were on their + + align:start position:0% +that people's hearts were on their + + + align:start position:0% +that people's hearts were on their +sleeves um this is the area where + + align:start position:0% +sleeves um this is the area where + + + align:start position:0% +sleeves um this is the area where +Pepperdine University used to be there's + + align:start position:0% +Pepperdine University used to be there's + + + align:start position:0% +Pepperdine University used to be there's +now the khaw Christian Center which is + + align:start position:0% +now the khaw Christian Center which is + + + align:start position:0% +now the khaw Christian Center which is +one of these mega churches with + + align:start position:0% +one of these mega churches with + + + align:start position:0% +one of these mega churches with +something like 10,000 members and inside + + align:start position:0% +something like 10,000 members and inside + + + align:start position:0% +something like 10,000 members and inside +this huge building called the the faith + + align:start position:0% +this huge building called the the faith + + + align:start position:0% +this huge building called the the faith +Dome they have services that are + + align:start position:0% +Dome they have services that are + + + align:start position:0% +Dome they have services that are +televised and in fact they encourage you + + align:start position:0% +televised and in fact they encourage you + + + align:start position:0% +televised and in fact they encourage you +to sit in the front because they don't + + align:start position:0% +to sit in the front because they don't + + + align:start position:0% +to sit in the front because they don't +like to have empty seats it's bad for + + align:start position:0% + + + + align:start position:0% + +business so they didn't actually like me + + align:start position:0% +business so they didn't actually like me + + + align:start position:0% +business so they didn't actually like me +taking this picture in fact they um but + + align:start position:0% +taking this picture in fact they um but + + + align:start position:0% +taking this picture in fact they um but +it's it was interesting so this was a + + align:start position:0% +it's it was interesting so this was a + + + align:start position:0% +it's it was interesting so this was a +kind of mega church is almost corporate + + align:start position:0% +kind of mega church is almost corporate + + + align:start position:0% +kind of mega church is almost corporate +in nature and then right next to it was + + align:start position:0% +in nature and then right next to it was + + + align:start position:0% +in nature and then right next to it was +a very small Multicultural uh + + align:start position:0% +a very small Multicultural uh + + + align:start position:0% +a very small Multicultural uh +bilingual um uh Pentecostal Church where + + align:start position:0% +bilingual um uh Pentecostal Church where + + + align:start position:0% +bilingual um uh Pentecostal Church where +everything was done in two + + align:start position:0% + + + + align:start position:0% + +languages and then in a farther up + + align:start position:0% +languages and then in a farther up + + + align:start position:0% +languages and then in a farther up +kinshaw this guy's been here for Years + + align:start position:0% +kinshaw this guy's been here for Years + + + align:start position:0% +kinshaw this guy's been here for Years +love that + + align:start position:0% +love that + + + align:start position:0% +love that +sign and it was interesting that that I + + align:start position:0% +sign and it was interesting that that I + + + align:start position:0% +sign and it was interesting that that I +kind of hit this when I had sort of + + align:start position:0% +kind of hit this when I had sort of + + + align:start position:0% +kind of hit this when I had sort of +gotten some momentum going I don't know + + align:start position:0% +gotten some momentum going I don't know + + + align:start position:0% +gotten some momentum going I don't know +if I could have taken these pictures + + align:start position:0% +if I could have taken these pictures + + + align:start position:0% +if I could have taken these pictures +Well Pro I'd like to think I would but + + align:start position:0% +Well Pro I'd like to think I would but + + + align:start position:0% +Well Pro I'd like to think I would but +um I don't know if I would have uh I I + + align:start position:0% +um I don't know if I would have uh I I + + + align:start position:0% +um I don't know if I would have uh I I +know I'm sort of uh on a role because no + + align:start position:0% +know I'm sort of uh on a role because no + + + align:start position:0% +know I'm sort of uh on a role because no +one questioned me and we were talking + + align:start position:0% +one questioned me and we were talking + + + align:start position:0% +one questioned me and we were talking +about it I you get to hear the story + + align:start position:0% +about it I you get to hear the story + + + align:start position:0% +about it I you get to hear the story +twice I had a paper out Ben you probably + + align:start position:0% +twice I had a paper out Ben you probably + + + align:start position:0% +twice I had a paper out Ben you probably +heard the story also I had a paper out + + align:start position:0% +heard the story also I had a paper out + + + align:start position:0% +heard the story also I had a paper out +when I was a kid and the only thing I + + align:start position:0% +when I was a kid and the only thing I + + + align:start position:0% +when I was a kid and the only thing I +learned from it was that dogs will chase + + align:start position:0% +learned from it was that dogs will chase + + + align:start position:0% +learned from it was that dogs will chase +you if you're frightened of them and + + align:start position:0% +you if you're frightened of them and + + + align:start position:0% +you if you're frightened of them and +that absolutely applies to photography + + align:start position:0% +that absolutely applies to photography + + + align:start position:0% +that absolutely applies to photography +if you're feeling uncomfortable with + + align:start position:0% +if you're feeling uncomfortable with + + + align:start position:0% +if you're feeling uncomfortable with +what you're doing people will pick up on + + align:start position:0% +what you're doing people will pick up on + + + align:start position:0% +what you're doing people will pick up on +it they actually will pick up on it more + + align:start position:0% +it they actually will pick up on it more + + + align:start position:0% +it they actually will pick up on it more +in California than in New York and maybe + + align:start position:0% +in California than in New York and maybe + + + align:start position:0% +in California than in New York and maybe +even especially in New York cuz in New + + align:start position:0% +even especially in New York cuz in New + + + align:start position:0% +even especially in New York cuz in New +York I photograph people doing illegal + + align:start position:0% +York I photograph people doing illegal + + + align:start position:0% +York I photograph people doing illegal +things in didn't even look up in + + align:start position:0% +things in didn't even look up in + + + align:start position:0% +things in didn't even look up in +California everybody's in cars so the + + align:start position:0% +California everybody's in cars so the + + + align:start position:0% +California everybody's in cars so the +idea of actually facing someone face to + + align:start position:0% +idea of actually facing someone face to + + + align:start position:0% +idea of actually facing someone face to +face is a little more foreign and people + + align:start position:0% +face is a little more foreign and people + + + align:start position:0% +face is a little more foreign and people +are more suspicious but if you are if + + align:start position:0% +are more suspicious but if you are if + + + align:start position:0% +are more suspicious but if you are if +you know this whole thing about stealing + + align:start position:0% +you know this whole thing about stealing + + + align:start position:0% +you know this whole thing about stealing +Souls you can only steal someone's Soul + + align:start position:0% +Souls you can only steal someone's Soul + + + align:start position:0% +Souls you can only steal someone's Soul +if that's your intent I really believe + + align:start position:0% +if that's your intent I really believe + + + align:start position:0% +if that's your intent I really believe +that and people can pick up on it and + + align:start position:0% +that and people can pick up on it and + + + align:start position:0% +that and people can pick up on it and +especially um uh people of color and + + align:start position:0% +especially um uh people of color and + + + align:start position:0% +especially um uh people of color and +people in um communities that have been + + align:start position:0% +people in um communities that have been + + + align:start position:0% +people in um communities that have been +under the gun and that have been + + align:start position:0% +under the gun and that have been + + + align:start position:0% +under the gun and that have been +exploited by media can absolutely their + + align:start position:0% +exploited by media can absolutely their + + + align:start position:0% +exploited by media can absolutely their + detector is um pretty stri on + + align:start position:0% + detector is um pretty stri on + + + align:start position:0% + detector is um pretty stri on +so it was interesting to me I could kind + + align:start position:0% +so it was interesting to me I could kind + + + align:start position:0% +so it was interesting to me I could kind +of judge by the way people reacting to + + align:start position:0% +of judge by the way people reacting to + + + align:start position:0% +of judge by the way people reacting to +me that both I was really into doing + + align:start position:0% +me that both I was really into doing + + + align:start position:0% +me that both I was really into doing +this and that maybe my heart was pure as + + align:start position:0% +this and that maybe my heart was pure as + + + align:start position:0% +this and that maybe my heart was pure as +pure as it could + + align:start position:0% + + + + align:start position:0% + +get so there's sort of the everpresent + + align:start position:0% +get so there's sort of the everpresent + + + align:start position:0% +get so there's sort of the everpresent +palm and the representation of it I + + align:start position:0% +palm and the representation of it I + + + align:start position:0% +palm and the representation of it I +photographed there was a motel I didn't + + align:start position:0% +photographed there was a motel I didn't + + + align:start position:0% +photographed there was a motel I didn't +include it but it's the motel where Sam + + align:start position:0% +include it but it's the motel where Sam + + + align:start position:0% +include it but it's the motel where Sam +Cook was killed which is right up the + + align:start position:0% +Cook was killed which is right up the + + + align:start position:0% +Cook was killed which is right up the +street from from here here um there's + + align:start position:0% +street from from here here um there's + + + align:start position:0% +street from from here here um there's +like you know you sort of drive and + + align:start position:0% +like you know you sort of drive and + + + align:start position:0% +like you know you sort of drive and +someone will have four drum sets just + + align:start position:0% +someone will have four drum sets just + + + align:start position:0% +someone will have four drum sets just +set up in an empty lot selling it and + + align:start position:0% +set up in an empty lot selling it and + + + align:start position:0% +set up in an empty lot selling it and +then there's besides the kind of + + align:start position:0% +then there's besides the kind of + + + align:start position:0% +then there's besides the kind of +religious iconography there these + + align:start position:0% +religious iconography there these + + + align:start position:0% +religious iconography there these +incredible I think they're really + + align:start position:0% +incredible I think they're really + + + align:start position:0% +incredible I think they're really +beautiful um sort of you know uh + + align:start position:0% +beautiful um sort of you know uh + + + align:start position:0% +beautiful um sort of you know uh +vernacular expressions of + + align:start position:0% +vernacular expressions of + + + align:start position:0% +vernacular expressions of +Commerce so right next to the uh kinof + + align:start position:0% +Commerce so right next to the uh kinof + + + align:start position:0% +Commerce so right next to the uh kinof +um Christian Center was a neighborhood + + align:start position:0% +um Christian Center was a neighborhood + + + align:start position:0% +um Christian Center was a neighborhood +called Vermont nolles which has some of + + align:start position:0% +called Vermont nolles which has some of + + + align:start position:0% +called Vermont nolles which has some of +the nicest houses housing stock in Los + + align:start position:0% +the nicest houses housing stock in Los + + + align:start position:0% +the nicest houses housing stock in Los +Angeles 100% African-American in fact + + align:start position:0% +Angeles 100% African-American in fact + + + align:start position:0% +Angeles 100% African-American in fact +they're very suspicious of this new + + align:start position:0% +they're very suspicious of this new + + + align:start position:0% +they're very suspicious of this new +building but um again people there sort + + align:start position:0% +building but um again people there sort + + + align:start position:0% +building but um again people there sort +of stereotypes about where black people + + align:start position:0% +of stereotypes about where black people + + + align:start position:0% +of stereotypes about where black people +live and what their lives are like and + + align:start position:0% +live and what their lives are like and + + + align:start position:0% +live and what their lives are like and +here was this incredibly immaculately + + align:start position:0% +here was this incredibly immaculately + + + align:start position:0% +here was this incredibly immaculately +landscaped uh neighborhood um that uh + + align:start position:0% +landscaped uh neighborhood um that uh + + + align:start position:0% +landscaped uh neighborhood um that uh +people are fighting to try to live in + + align:start position:0% + + + + align:start position:0% + +a lot of these are on Vermont Vermont is + + align:start position:0% +a lot of these are on Vermont Vermont is + + + align:start position:0% +a lot of these are on Vermont Vermont is +the second busiest bus travel people do + + align:start position:0% +the second busiest bus travel people do + + + align:start position:0% +the second busiest bus travel people do +take buses in La contrary to popular and + + align:start position:0% +take buses in La contrary to popular and + + + align:start position:0% +take buses in La contrary to popular and +and so that was part of the idea was my + + align:start position:0% +and so that was part of the idea was my + + + align:start position:0% +and so that was part of the idea was my +idea was I wanted to make these + + align:start position:0% +idea was I wanted to make these + + + align:start position:0% +idea was I wanted to make these +photographs large in kind of light boxes + + align:start position:0% +photographs large in kind of light boxes + + + align:start position:0% +photographs large in kind of light boxes +that you'd be able to see regardless of + + align:start position:0% +that you'd be able to see regardless of + + + align:start position:0% +that you'd be able to see regardless of +how you were passing by uh vehicle or + + align:start position:0% +how you were passing by uh vehicle or + + + align:start position:0% +how you were passing by uh vehicle or +foot traffic and also if you were using + + align:start position:0% +foot traffic and also if you were using + + + align:start position:0% +foot traffic and also if you were using +the building + + align:start position:0% + + + + align:start position:0% + +so my proposal although I didn't get to + + align:start position:0% +so my proposal although I didn't get to + + + align:start position:0% +so my proposal although I didn't get to +reiterate it was um uh I had uh + + align:start position:0% +reiterate it was um uh I had uh + + + align:start position:0% +reiterate it was um uh I had uh +contracted with um a sign maker and + + align:start position:0% +contracted with um a sign maker and + + + align:start position:0% +contracted with um a sign maker and +someone who makes these huge boxes for + + align:start position:0% +someone who makes these huge boxes for + + + align:start position:0% +someone who makes these huge boxes for +advertising and I was going to place + + align:start position:0% +advertising and I was going to place + + + align:start position:0% +advertising and I was going to place +them on the building um I was actually + + align:start position:0% +them on the building um I was actually + + + align:start position:0% +them on the building um I was actually +in the middle of working on the book so + + align:start position:0% +in the middle of working on the book so + + + align:start position:0% +in the middle of working on the book so +my presentation was to show and be very + + align:start position:0% +my presentation was to show and be very + + + align:start position:0% +my presentation was to show and be very +enthusiastic about the images which I + + align:start position:0% +enthusiastic about the images which I + + + align:start position:0% +enthusiastic about the images which I +was actually more interested in even + + align:start position:0% +was actually more interested in even + + + align:start position:0% +was actually more interested in even +than doing the public art so what they + + align:start position:0% +than doing the public art so what they + + + align:start position:0% +than doing the public art so what they +they someone else is going to do um the + + align:start position:0% +they someone else is going to do um the + + + align:start position:0% +they someone else is going to do um the +sort of imagery on the outside of the + + align:start position:0% +sort of imagery on the outside of the + + + align:start position:0% +sort of imagery on the outside of the +building but they are are going to use + + align:start position:0% +building but they are are going to use + + + align:start position:0% +building but they are are going to use +my photographs of the community inside + + align:start position:0% +my photographs of the community inside + + + align:start position:0% +my photographs of the community inside +the building so that the clients will + + align:start position:0% +the building so that the clients will + + + align:start position:0% +the building so that the clients will +actually see them and they I thought I + + align:start position:0% +actually see them and they I thought I + + + align:start position:0% +actually see them and they I thought I +mean I was really interested that the + + align:start position:0% +mean I was really interested that the + + + align:start position:0% +mean I was really interested that the +the story was more complex and meets the + + align:start position:0% +the story was more complex and meets the + + + align:start position:0% +the story was more complex and meets the +eye and I thought it was interested and + + align:start position:0% +eye and I thought it was interested and + + + align:start position:0% +eye and I thought it was interested and +important that the clients and the + + align:start position:0% +important that the clients and the + + + align:start position:0% +important that the clients and the +people in Community saw a reflection of + + align:start position:0% +people in Community saw a reflection of + + + align:start position:0% +people in Community saw a reflection of +that because they know that but a lot of + + align:start position:0% +that because they know that but a lot of + + + align:start position:0% +that because they know that but a lot of +other people + + align:start position:0% +other people + + + align:start position:0% +other people +don't so naturally I was very + + align:start position:0% +don't so naturally I was very + + + align:start position:0% +don't so naturally I was very +disappointed and paying quite close + + align:start position:0% +disappointed and paying quite close + + + align:start position:0% +disappointed and paying quite close +attention to the course of Katrina as it + + align:start position:0% +attention to the course of Katrina as it + + + align:start position:0% +attention to the course of Katrina as it +was bearing on New Orleans uh the the + + align:start position:0% +was bearing on New Orleans uh the the + + + align:start position:0% +was bearing on New Orleans uh the the +year before I had been there right after + + align:start position:0% +year before I had been there right after + + + align:start position:0% +year before I had been there right after +I can't remember the name of the + + align:start position:0% +I can't remember the name of the + + + align:start position:0% +I can't remember the name of the +hurricane that AED at the last minute + + align:start position:0% +hurricane that AED at the last minute + + + align:start position:0% +hurricane that AED at the last minute +and I hadn't really thought about it but + + align:start position:0% +and I hadn't really thought about it but + + + align:start position:0% +and I hadn't really thought about it but +a lot of people left and it was + + align:start position:0% +a lot of people left and it was + + + align:start position:0% +a lot of people left and it was +interesting it was really on class lines + + align:start position:0% +interesting it was really on class lines + + + align:start position:0% +interesting it was really on class lines +who left and who didn't and on the one + + align:start position:0% +who left and who didn't and on the one + + + align:start position:0% +who left and who didn't and on the one +hand you know know it would be + + align:start position:0% +hand you know know it would be + + + align:start position:0% +hand you know know it would be +interesting as a what am I as a + + align:start position:0% +interesting as a what am I as a + + + align:start position:0% +interesting as a what am I as a +photographer social scientist or the son + + align:start position:0% +photographer social scientist or the son + + + align:start position:0% +photographer social scientist or the son +of social scientist to have been with + + align:start position:0% +of social scientist to have been with + + + align:start position:0% +of social scientist to have been with +there with a hurricane uh because i' you + + align:start position:0% +there with a hurricane uh because i' you + + + align:start position:0% +there with a hurricane uh because i' you +know like to experience it of course + + align:start position:0% +know like to experience it of course + + + align:start position:0% +know like to experience it of course +everybody who lives there said are you + + align:start position:0% +everybody who lives there said are you + + + align:start position:0% +everybody who lives there said are you +out of your mind uh and people I know + + align:start position:0% +out of your mind uh and people I know + + + align:start position:0% +out of your mind uh and people I know +that we're stuck there really you know + + align:start position:0% +that we're stuck there really you know + + + align:start position:0% +that we're stuck there really you know +especially after with all that we've + + align:start position:0% +especially after with all that we've + + + align:start position:0% +especially after with all that we've +heard so anyway um in East St Louis um + + align:start position:0% +heard so anyway um in East St Louis um + + + align:start position:0% +heard so anyway um in East St Louis um +before New Orleans was closed you had to + + align:start position:0% +before New Orleans was closed you had to + + + align:start position:0% +before New Orleans was closed you had to +show ID you know and it did it opened up + + align:start position:0% +show ID you know and it did it opened up + + + align:start position:0% +show ID you know and it did it opened up +although there's no way to get there so + + align:start position:0% +although there's no way to get there so + + + align:start position:0% +although there's no way to get there so +I had to rent a car in Memphis driveth + + align:start position:0% +I had to rent a car in Memphis driveth + + + align:start position:0% +I had to rent a car in Memphis driveth +through Mississippi actually took + + align:start position:0% +through Mississippi actually took + + + align:start position:0% +through Mississippi actually took +picture of cotton for the first time I + + align:start position:0% +picture of cotton for the first time I + + + align:start position:0% +picture of cotton for the first time I +once drove all the way across the + + align:start position:0% +once drove all the way across the + + + align:start position:0% +once drove all the way across the +country and the first place I saw cotton + + align:start position:0% +country and the first place I saw cotton + + + align:start position:0% +country and the first place I saw cotton +was in Bakersfield I don't know what + + align:start position:0% +was in Bakersfield I don't know what + + + align:start position:0% +was in Bakersfield I don't know what +that's about so anyway but New Orleans + + align:start position:0% +that's about so anyway but New Orleans + + + align:start position:0% +that's about so anyway but New Orleans +is a place I have gone to seven or eight + + align:start position:0% +is a place I have gone to seven or eight + + + align:start position:0% +is a place I have gone to seven or eight +times in the last 12 years and uh I you + + align:start position:0% +times in the last 12 years and uh I you + + + align:start position:0% +times in the last 12 years and uh I you +know was very anxious to go I went in + + align:start position:0% +know was very anxious to go I went in + + + align:start position:0% +know was very anxious to go I went in +October um but I had been there before + + align:start position:0% +October um but I had been there before + + + align:start position:0% +October um but I had been there before +and what I wanted to show you this is uh + + align:start position:0% +and what I wanted to show you this is uh + + + align:start position:0% +and what I wanted to show you this is uh +John Scott who's a a MacArthur fellow + + align:start position:0% +John Scott who's a a MacArthur fellow + + + align:start position:0% +John Scott who's a a MacArthur fellow +sculptor who teaches at Xavier + + align:start position:0% +sculptor who teaches at Xavier + + + align:start position:0% +sculptor who teaches at Xavier +University and this is a spirit house + + align:start position:0% +University and this is a spirit house + + + align:start position:0% +University and this is a spirit house +which is again based on the model of the + + align:start position:0% +which is again based on the model of the + + + align:start position:0% +which is again based on the model of the +shotgun house and on the walls are these + + align:start position:0% +shotgun house and on the walls are these + + + align:start position:0% +shotgun house and on the walls are these +cutouts that have narratives of the + + align:start position:0% +cutouts that have narratives of the + + + align:start position:0% +cutouts that have narratives of the +African-American story in Louisiana the + + align:start position:0% +African-American story in Louisiana the + + + align:start position:0% +African-American story in Louisiana the +relationship with the Indians and uh it + + align:start position:0% +relationship with the Indians and uh it + + + align:start position:0% +relationship with the Indians and uh it +was um built it's on St + + align:start position:0% +was um built it's on St + + + align:start position:0% +was um built it's on St +um I think it's on St Bernard's um and + + align:start position:0% +um I think it's on St Bernard's um and + + + align:start position:0% +um I think it's on St Bernard's um and +so I was very curious to see if it + + align:start position:0% +so I was very curious to see if it + + + align:start position:0% +so I was very curious to see if it +surviv the hurricane so that was one of + + align:start position:0% +surviv the hurricane so that was one of + + + align:start position:0% +surviv the hurricane so that was one of +the first places I went when I + + align:start position:0% +the first places I went when I + + + align:start position:0% +the first places I went when I +arrived um St Rock is in the Bywater and + + align:start position:0% +arrived um St Rock is in the Bywater and + + + align:start position:0% +arrived um St Rock is in the Bywater and +St Rox is the miracle is the patron + + align:start position:0% +St Rox is the miracle is the patron + + + align:start position:0% +St Rox is the miracle is the patron +saint of miracle cures and this is a + + align:start position:0% +saint of miracle cures and this is a + + + align:start position:0% +saint of miracle cures and this is a +picture I took + + align:start position:0% +picture I took + + + align:start position:0% +picture I took +in 2000 of this chapel and I'm assuming + + align:start position:0% +in 2000 of this chapel and I'm assuming + + + align:start position:0% +in 2000 of this chapel and I'm assuming +he must be the patron saint because + + align:start position:0% +he must be the patron saint because + + + align:start position:0% +he must be the patron saint because +there are all these braces and um alleys + + align:start position:0% +there are all these braces and um alleys + + + align:start position:0% +there are all these braces and um alleys +and I took this picture uh in 2004 this + + align:start position:0% +and I took this picture uh in 2004 this + + + align:start position:0% +and I took this picture uh in 2004 this +is in the chapel and there's this Crush + + align:start position:0% +is in the chapel and there's this Crush + + + align:start position:0% +is in the chapel and there's this Crush +which is pretty spooky one thing I have + + align:start position:0% +which is pretty spooky one thing I have + + + align:start position:0% +which is pretty spooky one thing I have +to say about New Orleans and the whole + + align:start position:0% +to say about New Orleans and the whole + + + align:start position:0% +to say about New Orleans and the whole +notion of faith faith seems much more + + align:start position:0% +notion of faith faith seems much more + + + align:start position:0% +notion of faith faith seems much more +viable when it's 100° and 100% humidity + + align:start position:0% +viable when it's 100° and 100% humidity + + + align:start position:0% +viable when it's 100° and 100% humidity +sort of a particular kind of Fai this is + + align:start position:0% +sort of a particular kind of Fai this is + + + align:start position:0% +sort of a particular kind of Fai this is +what that Chapel looked like in + + align:start position:0% +what that Chapel looked like in + + + align:start position:0% +what that Chapel looked like in +October and as is + + align:start position:0% +October and as is + + + align:start position:0% +October and as is +this so the Bywater did um flood this is + + align:start position:0% +this so the Bywater did um flood this is + + + align:start position:0% +this so the Bywater did um flood this is +the budoo spiritualist church on Rampart + + align:start position:0% +the budoo spiritualist church on Rampart + + + align:start position:0% +the budoo spiritualist church on Rampart +Street I love the fact that the streets + + align:start position:0% +Street I love the fact that the streets + + + align:start position:0% +Street I love the fact that the streets +in New Orleans are actually named after + + align:start position:0% +in New Orleans are actually named after + + + align:start position:0% +in New Orleans are actually named after +Jazz well it's the other way around + + align:start position:0% +Jazz well it's the other way around + + + align:start position:0% +Jazz well it's the other way around +there's a lot of jazz especially um well + + align:start position:0% +there's a lot of jazz especially um well + + + align:start position:0% +there's a lot of jazz especially um well +through the history of jazz but uh BAS + + align:start position:0% +through the history of jazz but uh BAS + + + align:start position:0% +through the history of jazz but uh BAS +Street Rampart Street I mean they were + + align:start position:0% +Street Rampart Street I mean they were + + + align:start position:0% +Street Rampart Street I mean they were +based on these streets and then the + + align:start position:0% +based on these streets and then the + + + align:start position:0% +based on these streets and then the +other streets are named after the muses + + align:start position:0% +other streets are named after the muses + + + align:start position:0% +other streets are named after the muses +so in 1994 when I first went I was uh + + align:start position:0% +so in 1994 when I first went I was uh + + + align:start position:0% +so in 1994 when I first went I was uh +walking in uh T this is a Calo uh + + align:start position:0% +walking in uh T this is a Calo uh + + + align:start position:0% +walking in uh T this is a Calo uh +housing project and I heard music you + + align:start position:0% +housing project and I heard music you + + + align:start position:0% +housing project and I heard music you +know I was looking for uh funerals I + + align:start position:0% +know I was looking for uh funerals I + + + align:start position:0% +know I was looking for uh funerals I +knew about the tradition and here were + + align:start position:0% +knew about the tradition and here were + + + align:start position:0% +knew about the tradition and here were +these um 15 and 16 year olds a brass + + align:start position:0% +these um 15 and 16 year olds a brass + + + align:start position:0% +these um 15 and 16 year olds a brass +band playing better than a lot of + + align:start position:0% +band playing better than a lot of + + + align:start position:0% +band playing better than a lot of +professional musicians I know um it + + align:start position:0% +professional musicians I know um it + + + align:start position:0% +professional musicians I know um it +turned out that this woman's son had + + align:start position:0% +turned out that this woman's son had + + + align:start position:0% +turned out that this woman's son had +died died at Sea and so they were having + + align:start position:0% +died died at Sea and so they were having + + + align:start position:0% +died died at Sea and so they were having +a + + align:start position:0% +a + + + align:start position:0% +a +wake and um the thing that was immediate + + align:start position:0% +wake and um the thing that was immediate + + + align:start position:0% +wake and um the thing that was immediate +to me was that sort of expressions of + + align:start position:0% +to me was that sort of expressions of + + + align:start position:0% +to me was that sort of expressions of +culture in New Orleans are certainly an + + align:start position:0% +culture in New Orleans are certainly an + + + align:start position:0% +culture in New Orleans are certainly an +amalgam of a lot of things um Africa uh + + align:start position:0% +amalgam of a lot of things um Africa uh + + + align:start position:0% +amalgam of a lot of things um Africa uh +um Native American Europe Caribbean um + + align:start position:0% +um Native American Europe Caribbean um + + + align:start position:0% +um Native American Europe Caribbean um +but then there's all these things that + + align:start position:0% +but then there's all these things that + + + align:start position:0% +but then there's all these things that +are very unique there are people that do + + align:start position:0% +are very unique there are people that do + + + align:start position:0% +are very unique there are people that do +things in New Orleans that they haven't + + align:start position:0% +things in New Orleans that they haven't + + + align:start position:0% +things in New Orleans that they haven't +done anywhere else there's the story of + + align:start position:0% +done anywhere else there's the story of + + + align:start position:0% +done anywhere else there's the story of +Congo Square the SLA the French let the + + align:start position:0% +Congo Square the SLA the French let the + + + align:start position:0% +Congo Square the SLA the French let the +slaves play instruments the Americans + + align:start position:0% +slaves play instruments the Americans + + + align:start position:0% +slaves play instruments the Americans +did not not so there's some argument + + align:start position:0% +did not not so there's some argument + + + align:start position:0% +did not not so there's some argument +about where Jazz invented but um the + + align:start position:0% +about where Jazz invented but um the + + + align:start position:0% +about where Jazz invented but um the +people the New Orleans apologists say + + align:start position:0% +people the New Orleans apologists say + + + align:start position:0% +people the New Orleans apologists say +that that's where it's from and so again + + align:start position:0% +that that's where it's from and so again + + + align:start position:0% +that that's where it's from and so again +um I was going to say without an agenda + + align:start position:0% +um I was going to say without an agenda + + + align:start position:0% +um I was going to say without an agenda +I have an agenda but I'm I'm sort of + + align:start position:0% +I have an agenda but I'm I'm sort of + + + align:start position:0% +I have an agenda but I'm I'm sort of +interested and and it was interested + + align:start position:0% +interested and and it was interested + + + align:start position:0% +interested and and it was interested +putting these slides together because + + align:start position:0% +putting these slides together because + + + align:start position:0% +putting these slides together because +I'm trying to sort of make some sense of + + align:start position:0% +I'm trying to sort of make some sense of + + + align:start position:0% +I'm trying to sort of make some sense of +what is the thread that runs and maybe + + align:start position:0% +what is the thread that runs and maybe + + + align:start position:0% +what is the thread that runs and maybe +you can tell me um this is someone + + align:start position:0% +you can tell me um this is someone + + + align:start position:0% +you can tell me um this is someone +playing air guitar outside of a blues + + align:start position:0% +playing air guitar outside of a blues + + + align:start position:0% +playing air guitar outside of a blues +Club in the French + + align:start position:0% +Club in the French + + + align:start position:0% +Club in the French +Quarter here's uh this is actually on + + align:start position:0% +Quarter here's uh this is actually on + + + align:start position:0% +Quarter here's uh this is actually on +Rampart Street this is in t this is pre + + align:start position:0% +Rampart Street this is in t this is pre + + + align:start position:0% +Rampart Street this is in t this is pre +Katrina and uh there's basically a + + align:start position:0% +Katrina and uh there's basically a + + + align:start position:0% +Katrina and uh there's basically a +demonstration to try to fight um + + align:start position:0% +demonstration to try to fight um + + + align:start position:0% +demonstration to try to fight um +gentrification T again has real + + align:start position:0% +gentrification T again has real + + + align:start position:0% +gentrification T again has real +interesting housing stock it's right off + + align:start position:0% +interesting housing stock it's right off + + + align:start position:0% +interesting housing stock it's right off +the French quarter and there sort of + + align:start position:0% +the French quarter and there sort of + + + align:start position:0% +the French quarter and there sort of +it's changing this is actually was at + + align:start position:0% +it's changing this is actually was at + + + align:start position:0% +it's changing this is actually was at +the dedication of the spirit house um so + + align:start position:0% +the dedication of the spirit house um so + + + align:start position:0% +the dedication of the spirit house um so +I finally got to see my uh marching band + + align:start position:0% +I finally got to see my uh marching band + + + align:start position:0% +I finally got to see my uh marching band +this a t Brass + + align:start position:0% + + + + align:start position:0% + +Band I'm sort of uh + + align:start position:0% +Band I'm sort of uh + + + align:start position:0% +Band I'm sort of uh +uh I I think I think I see better in + + align:start position:0% +uh I I think I think I see better in + + + align:start position:0% +uh I I think I think I see better in +black and white I also see better with + + align:start position:0% +black and white I also see better with + + + align:start position:0% +black and white I also see better with +non autofocusing cameras but I do love + + align:start position:0% +non autofocusing cameras but I do love + + + align:start position:0% +non autofocusing cameras but I do love +my Nikon d70 it was actually a problem + + align:start position:0% +my Nikon d70 it was actually a problem + + + align:start position:0% +my Nikon d70 it was actually a problem +during the trip because I was switching + + align:start position:0% +during the trip because I was switching + + + align:start position:0% +during the trip because I was switching +back and forth and and I don't think I + + align:start position:0% +back and forth and and I don't think I + + + align:start position:0% +back and forth and and I don't think I +want to keep doing that so I either am + + align:start position:0% +want to keep doing that so I either am + + + align:start position:0% +want to keep doing that so I either am +going to either go high-end digital or + + align:start position:0% +going to either go high-end digital or + + + align:start position:0% +going to either go high-end digital or +shoot more film and just use digital for + + align:start position:0% +shoot more film and just use digital for + + + align:start position:0% +shoot more film and just use digital for +taking notes but don't hold me to + + align:start position:0% +taking notes but don't hold me to + + + align:start position:0% +taking notes but don't hold me to +that so you're going to see photographs + + align:start position:0% +that so you're going to see photographs + + + align:start position:0% +that so you're going to see photographs +uh you're going to see more in a couple + + align:start position:0% +uh you're going to see more in a couple + + + align:start position:0% +uh you're going to see more in a couple +of weeks but you'll see some post + + align:start position:0% +of weeks but you'll see some post + + + align:start position:0% +of weeks but you'll see some post +Katrina photographs but and I've been + + align:start position:0% +Katrina photographs but and I've been + + + align:start position:0% +Katrina photographs but and I've been +showing them and I after 4 days of being + + align:start position:0% +showing them and I after 4 days of being + + + align:start position:0% +showing them and I after 4 days of being +there I arrived at like 7:30 at night I + + align:start position:0% +there I arrived at like 7:30 at night I + + + align:start position:0% +there I arrived at like 7:30 at night I +stayed with some friends that had + + align:start position:0% +stayed with some friends that had + + + align:start position:0% +stayed with some friends that had +literally come back a couple hours + + align:start position:0% +literally come back a couple hours + + + align:start position:0% +literally come back a couple hours +before I had and they'd been there for + + align:start position:0% +before I had and they'd been there for + + + align:start position:0% +before I had and they'd been there for +they' been gone for a month and a half + + align:start position:0% +they' been gone for a month and a half + + + align:start position:0% +they' been gone for a month and a half +it was the lights were sort of twick + + align:start position:0% +it was the lights were sort of twick + + + align:start position:0% +it was the lights were sort of twick +flickering cuz the power wasn't full + + align:start position:0% +flickering cuz the power wasn't full + + + align:start position:0% +flickering cuz the power wasn't full +there was nobody on the streets it was + + align:start position:0% +there was nobody on the streets it was + + + align:start position:0% +there was nobody on the streets it was +scary it was very spooky and I sort of + + align:start position:0% +scary it was very spooky and I sort of + + + align:start position:0% +scary it was very spooky and I sort of +ran out of my car under their house but + + align:start position:0% +ran out of my car under their house but + + + align:start position:0% +ran out of my car under their house but +um then I photographed 12 hours a day + + align:start position:0% +um then I photographed 12 hours a day + + + align:start position:0% +um then I photographed 12 hours a day +for 5 days straight and then I Got U + + align:start position:0% +for 5 days straight and then I Got U + + + align:start position:0% +for 5 days straight and then I Got U +destruction + + align:start position:0% +destruction + + + align:start position:0% +destruction +fatigue um here's a sort of something in + + align:start position:0% +fatigue um here's a sort of something in + + + align:start position:0% +fatigue um here's a sort of something in +the Katrina um talking about sellouts + + align:start position:0% +the Katrina um talking about sellouts + + + align:start position:0% +the Katrina um talking about sellouts +this is taken uh on the River Road + + align:start position:0% +this is taken uh on the River Road + + + align:start position:0% +this is taken uh on the River Road +between um Baton Rouge and Louisiana and + + align:start position:0% +between um Baton Rouge and Louisiana and + + + align:start position:0% +between um Baton Rouge and Louisiana and +uh New Orleans called cancer alley it + + align:start position:0% +uh New Orleans called cancer alley it + + + align:start position:0% +uh New Orleans called cancer alley it +has one of the highest incidents of + + align:start position:0% +has one of the highest incidents of + + + align:start position:0% +has one of the highest incidents of +cancer in the country because all the + + align:start position:0% +cancer in the country because all the + + + align:start position:0% +cancer in the country because all the +petrochemical companies that dump into + + align:start position:0% +petrochemical companies that dump into + + + align:start position:0% +petrochemical companies that dump into +the water this is actually in Baton + + align:start position:0% +the water this is actually in Baton + + + align:start position:0% +the water this is actually in Baton +Rouge a place I've spent some time I've + + align:start position:0% +Rouge a place I've spent some time I've + + + align:start position:0% +Rouge a place I've spent some time I've +done um + + align:start position:0% +done um + + + align:start position:0% +done um +uh some things in I've had some shows + + align:start position:0% +uh some things in I've had some shows + + + align:start position:0% +uh some things in I've had some shows +there and done some things at LSU so + + align:start position:0% +there and done some things at LSU so + + + align:start position:0% +there and done some things at LSU so +I've actually been spending time in as + + align:start position:0% +I've actually been spending time in as + + + align:start position:0% +I've actually been spending time in as +much time in Baton Rouge although I + + align:start position:0% +much time in Baton Rouge although I + + + align:start position:0% +much time in Baton Rouge although I +always go back to New Orleans this is + + align:start position:0% +always go back to New Orleans this is + + + align:start position:0% +always go back to New Orleans this is +the Sweet Olive Cemetery an + + align:start position:0% +the Sweet Olive Cemetery an + + + align:start position:0% +the Sweet Olive Cemetery an +African-American Cemetery that had just + + align:start position:0% +African-American Cemetery that had just + + + align:start position:0% +African-American Cemetery that had just +had had been sort of been to ruins and + + align:start position:0% +had had been sort of been to ruins and + + + align:start position:0% +had had been sort of been to ruins and +was just starting to be um uh restored + + align:start position:0% +was just starting to be um uh restored + + + align:start position:0% +was just starting to be um uh restored +and I always thought this coffee pot was + + align:start position:0% +and I always thought this coffee pot was + + + align:start position:0% +and I always thought this coffee pot was +like this what you know incredible + + align:start position:0% +like this what you know incredible + + + align:start position:0% +like this what you know incredible +expression of culture and I think it is + + align:start position:0% +expression of culture and I think it is + + + align:start position:0% +expression of culture and I think it is +but it also is a receptacle for the + + align:start position:0% +but it also is a receptacle for the + + + align:start position:0% +but it also is a receptacle for the +flowers you know always has a practical + + align:start position:0% +flowers you know always has a practical + + + align:start position:0% +flowers you know always has a practical +use this is um a a doll house in the + + align:start position:0% +use this is um a a doll house in the + + + align:start position:0% +use this is um a a doll house in the +form the shape of a shotgun house um + + align:start position:0% +form the shape of a shotgun house um + + + align:start position:0% +form the shape of a shotgun house um +it's a crypt for a + + align:start position:0% +it's a crypt for a + + + align:start position:0% +it's a crypt for a +child I love that and then I love these + + align:start position:0% +child I love that and then I love these + + + align:start position:0% +child I love that and then I love these +kind of hand scratching on the + + align:start position:0% + + + + align:start position:0% + +gravestones so after having kind of both + + align:start position:0% +gravestones so after having kind of both + + + align:start position:0% +gravestones so after having kind of both +shown and looked at all my post Catrina + + align:start position:0% +shown and looked at all my post Catrina + + + align:start position:0% +shown and looked at all my post Catrina +what I realized was I really missed and + + align:start position:0% +what I realized was I really missed and + + + align:start position:0% +what I realized was I really missed and +was more interested in Pre Catrina or in + + align:start position:0% +was more interested in Pre Catrina or in + + + align:start position:0% +was more interested in Pre Catrina or in +New Orleans as it was and maybe will be + + align:start position:0% + + + + align:start position:0% + +it seemed appropriate at the time this + + align:start position:0% +it seemed appropriate at the time this + + + align:start position:0% +it seemed appropriate at the time this +is like about 12 years ago to shoot + + align:start position:0% +is like about 12 years ago to shoot + + + align:start position:0% +is like about 12 years ago to shoot +infrared in New Orleans although it's + + align:start position:0% +infrared in New Orleans although it's + + + align:start position:0% +infrared in New Orleans although it's +not necessary because the spirits are + + align:start position:0% +not necessary because the spirits are + + + align:start position:0% +not necessary because the spirits are +already there this is one of the few + + align:start position:0% +already there this is one of the few + + + align:start position:0% +already there this is one of the few +cemeteries in Orleans that where with + + align:start position:0% +cemeteries in Orleans that where with + + + align:start position:0% +cemeteries in Orleans that where with +Graves in the grounds Hope Cemetery + + align:start position:0% +Graves in the grounds Hope Cemetery + + + align:start position:0% +Graves in the grounds Hope Cemetery +another African-American Cemetery um + + align:start position:0% +another African-American Cemetery um + + + align:start position:0% +another African-American Cemetery um +this is in St Louis cemeter and this is + + align:start position:0% +this is in St Louis cemeter and this is + + + align:start position:0% +this is in St Louis cemeter and this is +Marie lao's uh grave uh uh Crypt you + + align:start position:0% +Marie lao's uh grave uh uh Crypt you + + + align:start position:0% +Marie lao's uh grave uh uh Crypt you +know because the water table so high + + align:start position:0% +know because the water table so high + + + align:start position:0% +know because the water table so high +most of the graves are above uh ground + + align:start position:0% +most of the graves are above uh ground + + + align:start position:0% +most of the graves are above uh ground +and then there's all this + + align:start position:0% +and then there's all this + + + align:start position:0% +and then there's all this +technology um this is maybe a drawing + + align:start position:0% +technology um this is maybe a drawing + + + align:start position:0% +technology um this is maybe a drawing +but the there's all these both + + align:start position:0% +but the there's all these both + + + align:start position:0% +but the there's all these both +photographs and drawings on the graves + + align:start position:0% +photographs and drawings on the graves + + + align:start position:0% +photographs and drawings on the graves +that at least when I've visited over the + + align:start position:0% +that at least when I've visited over the + + + align:start position:0% +that at least when I've visited over the +course of 10 years have not faded at all + + align:start position:0% +course of 10 years have not faded at all + + + align:start position:0% +course of 10 years have not faded at all +and I'm not sure I know the signs we did + + align:start position:0% +and I'm not sure I know the signs we did + + + align:start position:0% +and I'm not sure I know the signs we did +uh in richm are done with sort of inkjet + + align:start position:0% +uh in richm are done with sort of inkjet + + + align:start position:0% +uh in richm are done with sort of inkjet +printers using porcelain inks and then + + align:start position:0% +printers using porcelain inks and then + + + align:start position:0% +printers using porcelain inks and then +they're fired so there is it is possible + + align:start position:0% +they're fired so there is it is possible + + + align:start position:0% +they're fired so there is it is possible +to now + + align:start position:0% +to now + + + align:start position:0% +to now +display continuous tone photographs in + + align:start position:0% +display continuous tone photographs in + + + align:start position:0% +display continuous tone photographs in +uh sort of outside environments but + + align:start position:0% +uh sort of outside environments but + + + align:start position:0% +uh sort of outside environments but +someone in New Orleans has been hip to + + align:start position:0% +someone in New Orleans has been hip to + + + align:start position:0% +someone in New Orleans has been hip to +this technology before + + align:start position:0% + + + + align:start position:0% + +that so uh maybe in in + + align:start position:0% +that so uh maybe in in + + + align:start position:0% +that so uh maybe in in +19 99 or something said well you got to + + align:start position:0% +19 99 or something said well you got to + + + align:start position:0% +19 99 or something said well you got to +go to Fatz Domino's house Fats Domino + + align:start position:0% +go to Fatz Domino's house Fats Domino + + + align:start position:0% +go to Fatz Domino's house Fats Domino +lives in the Lower Ninth Ward lived um + + align:start position:0% +lives in the Lower Ninth Ward lived um + + + align:start position:0% +lives in the Lower Ninth Ward lived um +has this incredible house with all this + + align:start position:0% +has this incredible house with all this + + + align:start position:0% +has this incredible house with all this +nomenclature and I finally found it I + + align:start position:0% +nomenclature and I finally found it I + + + align:start position:0% +nomenclature and I finally found it I +mean I didn't know it was a ninth W but + + align:start position:0% +mean I didn't know it was a ninth W but + + + align:start position:0% +mean I didn't know it was a ninth W but +someone um took me there so I took this + + align:start position:0% +someone um took me there so I took this + + + align:start position:0% +someone um took me there so I took this +picture which I thought was really + + align:start position:0% +picture which I thought was really + + + align:start position:0% +picture which I thought was really +interesting and then um uh I was able to + + align:start position:0% +interesting and then um uh I was able to + + + align:start position:0% +interesting and then um uh I was able to +get access to the Lower Ninth by being + + align:start position:0% +get access to the Lower Ninth by being + + + align:start position:0% +get access to the Lower Ninth by being +embedded with the National Guard you'll + + align:start position:0% +embedded with the National Guard you'll + + + align:start position:0% +embedded with the National Guard you'll +see a little of that later um and I + + align:start position:0% +see a little of that later um and I + + + align:start position:0% +see a little of that later um and I +found his house again he actually there + + align:start position:0% +found his house again he actually there + + + align:start position:0% +found his house again he actually there +was rumors that he had died but he was + + align:start position:0% +was rumors that he had died but he was + + + align:start position:0% +was rumors that he had died but he was +rescued from the second story of his + + align:start position:0% +rescued from the second story of his + + + align:start position:0% +rescued from the second story of his +house in the back um but this was the + + align:start position:0% +house in the back um but this was the + + + align:start position:0% +house in the back um but this was the +graffiti on on front of his house um + + align:start position:0% +graffiti on on front of his house um + + + align:start position:0% +graffiti on on front of his house um +because the the the rumor was that he + + align:start position:0% +because the the the rumor was that he + + + align:start position:0% +because the the the rumor was that he +was dead + + align:start position:0% + + + + align:start position:0% + +so I it's interesting I think I need to + + align:start position:0% +so I it's interesting I think I need to + + + align:start position:0% +so I it's interesting I think I need to +print some of these it I've sort of lost + + align:start position:0% +print some of these it I've sort of lost + + + align:start position:0% +print some of these it I've sort of lost +a little interest in this I mean it's + + align:start position:0% +a little interest in this I mean it's + + + align:start position:0% +a little interest in this I mean it's +incredibly interesting and I think it + + align:start position:0% +incredibly interesting and I think it + + + align:start position:0% +incredibly interesting and I think it +fits within my interest um and what was + + align:start position:0% +fits within my interest um and what was + + + align:start position:0% +fits within my interest um and what was +left was a variety of ways that people + + align:start position:0% +left was a variety of ways that people + + + align:start position:0% +left was a variety of ways that people +were leaving their calling cards or the + + align:start position:0% +were leaving their calling cards or the + + + align:start position:0% +were leaving their calling cards or the +buildings became sort of the the wall + + align:start position:0% +buildings became sort of the the wall + + + align:start position:0% +buildings became sort of the the wall +where news um was + + align:start position:0% +where news um was + + + align:start position:0% +where news um was +left I saw this sign and I thought oh + + align:start position:0% +left I saw this sign and I thought oh + + + align:start position:0% +left I saw this sign and I thought oh +someone must be doing some kind of like + + align:start position:0% +someone must be doing some kind of like + + + align:start position:0% +someone must be doing some kind of like +19th century photo technique but of + + align:start position:0% +19th century photo technique but of + + + align:start position:0% +19th century photo technique but of +course this is really about restoring + + align:start position:0% +course this is really about restoring + + + align:start position:0% +course this is really about restoring +wet photographs was I was I was thinking + + align:start position:0% +wet photographs was I was I was thinking + + + align:start position:0% +wet photographs was I was I was thinking +wow maybe I'll you know check that + + align:start position:0% +wow maybe I'll you know check that + + + align:start position:0% +wow maybe I'll you know check that +out this is in the lower + + align:start position:0% +out this is in the lower + + + align:start position:0% +out this is in the lower +n99th in California I say if um the + + align:start position:0% +n99th in California I say if um the + + + align:start position:0% +n99th in California I say if um the +earthquake hits empty your refrigerator + + align:start position:0% +earthquake hits empty your refrigerator + + + align:start position:0% +earthquake hits empty your refrigerator +there's the there's sort of um uh the + + align:start position:0% +there's the there's sort of um uh the + + + align:start position:0% +there's the there's sort of um uh the +refrigerators basically were these toxic + + align:start position:0% +refrigerators basically were these toxic + + + align:start position:0% +refrigerators basically were these toxic +that had to be um uh duct tape clothes + + align:start position:0% +that had to be um uh duct tape clothes + + + align:start position:0% +that had to be um uh duct tape clothes +because literally they would + + align:start position:0% + + + + align:start position:0% + +explode and the SP there was a lot of + + align:start position:0% +explode and the SP there was a lot of + + + align:start position:0% +explode and the SP there was a lot of +you know markings by FEMA and SP SPCA + + align:start position:0% +you know markings by FEMA and SP SPCA + + + align:start position:0% +you know markings by FEMA and SP SPCA +and I couldn't help but think of + + align:start position:0% +and I couldn't help but think of + + + align:start position:0% +and I couldn't help but think of +Moses and the the uh the + + align:start position:0% +Moses and the the uh the + + + align:start position:0% +Moses and the the uh the +Nazis and maybe some more benevolent + + align:start position:0% +Nazis and maybe some more benevolent + + + align:start position:0% +Nazis and maybe some more benevolent +things and some of the markings were + + align:start position:0% +things and some of the markings were + + + align:start position:0% +things and some of the markings were +actually really beautiful but they were + + align:start position:0% +actually really beautiful but they were + + + align:start position:0% +actually really beautiful but they were +also kind of spooky and then there was + + align:start position:0% +also kind of spooky and then there was + + + align:start position:0% +also kind of spooky and then there was +the everpresent because especially in a + + align:start position:0% +the everpresent because especially in a + + + align:start position:0% +the everpresent because especially in a +lot of areas it flooded multiple times + + align:start position:0% +lot of areas it flooded multiple times + + + align:start position:0% +lot of areas it flooded multiple times +there were these incredible lines all + + align:start position:0% +there were these incredible lines all + + + align:start position:0% +there were these incredible lines all +over everything that that sort of marked + + align:start position:0% +over everything that that sort of marked + + + align:start position:0% +over everything that that sort of marked +where the and because the water was so + + align:start position:0% +where the and because the water was so + + + align:start position:0% +where the and because the water was so +toxic it really did it sort of etched + + align:start position:0% +toxic it really did it sort of etched + + + align:start position:0% +toxic it really did it sort of etched +into a lot of + + align:start position:0% +into a lot of + + + align:start position:0% +into a lot of +surfaces and they were sort of the + + align:start position:0% +surfaces and they were sort of the + + + align:start position:0% +surfaces and they were sort of the +everpresent editorial + + align:start position:0% +everpresent editorial + + + align:start position:0% +everpresent editorial +comments I guess they're selling + + align:start position:0% +comments I guess they're selling + + + align:start position:0% +comments I guess they're selling +T-shirts in the French + + align:start position:0% +T-shirts in the French + + + align:start position:0% +T-shirts in the French +Quarter and a lot of uh you see a lot of + + align:start position:0% +Quarter and a lot of uh you see a lot of + + + align:start position:0% +Quarter and a lot of uh you see a lot of +abandoned bus buses uh they were + + align:start position:0% + + + + align:start position:0% + +commandeered so what you're seeing I + + align:start position:0% +commandeered so what you're seeing I + + + align:start position:0% +commandeered so what you're seeing I +shot a lot of black black and white + + align:start position:0% +shot a lot of black black and white + + + align:start position:0% +shot a lot of black black and white +which I'm just sort of getting + + align:start position:0% +which I'm just sort of getting + + + align:start position:0% +which I'm just sort of getting +to this is in the Cooper housing project + + align:start position:0% +to this is in the Cooper housing project + + + align:start position:0% +to this is in the Cooper housing project +you'll see a little bit of that later + + align:start position:0% +you'll see a little bit of that later + + + align:start position:0% +you'll see a little bit of that later +which was completely abandoned and I + + align:start position:0% +which was completely abandoned and I + + + align:start position:0% +which was completely abandoned and I +understand now is actually in pretty + + align:start position:0% +understand now is actually in pretty + + + align:start position:0% +understand now is actually in pretty +good shape and they won't let the people + + align:start position:0% +good shape and they won't let the people + + + align:start position:0% +good shape and they won't let the people +back something like 300,000 abandoned + + align:start position:0% +back something like 300,000 abandoned + + + align:start position:0% +back something like 300,000 abandoned +cars in in New Orleans + + align:start position:0% + + + + align:start position:0% + +so I would say Aesthetics are real + + align:start position:0% +so I would say Aesthetics are real + + + align:start position:0% +so I would say Aesthetics are real +important to me that you know kind of I + + align:start position:0% +important to me that you know kind of I + + + align:start position:0% +important to me that you know kind of I +think I do have there's certain things + + align:start position:0% +think I do have there's certain things + + + align:start position:0% +think I do have there's certain things +that I'm very interested in for a + + align:start position:0% +that I'm very interested in for a + + + align:start position:0% +that I'm very interested in for a +variety of reasons and I I tried this is + + align:start position:0% +variety of reasons and I I tried this is + + + align:start position:0% +variety of reasons and I I tried this is +the city park um at post this is the + + align:start position:0% +the city park um at post this is the + + + align:start position:0% +the city park um at post this is the +Martin Luther King library in the lower + + align:start position:0% +Martin Luther King library in the lower + + + align:start position:0% +Martin Luther King library in the lower +9th this is um the Cooper uh uh housing + + align:start position:0% +9th this is um the Cooper uh uh housing + + + align:start position:0% +9th this is um the Cooper uh uh housing +project um he was leaving the next week + + align:start position:0% +project um he was leaving the next week + + + align:start position:0% +project um he was leaving the next week +to go to California but he'd been he'd + + align:start position:0% +to go to California but he'd been he'd + + + align:start position:0% +to go to California but he'd been he'd +come back after the hurricane and been + + align:start position:0% +come back after the hurricane and been + + + align:start position:0% +come back after the hurricane and been +living there by + + align:start position:0% + + + + align:start position:0% + +himself if you're familiar with um + + align:start position:0% +himself if you're familiar with um + + + align:start position:0% +himself if you're familiar with um +Southern wrap gold teeth are quite + + align:start position:0% + + + + align:start position:0% + +big so I was on St claw's and actually I + + align:start position:0% +big so I was on St claw's and actually I + + + align:start position:0% +big so I was on St claw's and actually I +saw these guys with Scientology t-shirts + + align:start position:0% +saw these guys with Scientology t-shirts + + + align:start position:0% +saw these guys with Scientology t-shirts +in the courtyard of this and I was going + + align:start position:0% +in the courtyard of this and I was going + + + align:start position:0% +in the courtyard of this and I was going +what is that about so of course it was + + align:start position:0% +what is that about so of course it was + + + align:start position:0% +what is that about so of course it was +also a place where the National Guard + + align:start position:0% +also a place where the National Guard + + + align:start position:0% +also a place where the National Guard +was and to even get access I had to go + + align:start position:0% +was and to even get access I had to go + + + align:start position:0% +was and to even get access I had to go +through six layers of bureaucracy and i' + + align:start position:0% +through six layers of bureaucracy and i' + + + align:start position:0% +through six layers of bureaucracy and i' +had sort of given up um I had to call + + align:start position:0% +had sort of given up um I had to call + + + align:start position:0% +had sort of given up um I had to call +the chief of police this was right after + + align:start position:0% +the chief of police this was right after + + + align:start position:0% +the chief of police this was right after +there was the um African the 65-year-old + + align:start position:0% +there was the um African the 65-year-old + + + align:start position:0% +there was the um African the 65-year-old +African-American teacher was beaten up + + align:start position:0% +African-American teacher was beaten up + + + align:start position:0% +African-American teacher was beaten up +in the French Quarter so I was referred + + align:start position:0% +in the French Quarter so I was referred + + + align:start position:0% +in the French Quarter so I was referred +to the Public Public Relations person of + + align:start position:0% +to the Public Public Relations person of + + + align:start position:0% +to the Public Public Relations person of +the New Orleans police and he never did + + align:start position:0% +the New Orleans police and he never did + + + align:start position:0% +the New Orleans police and he never did +call me but he said just say I said it + + align:start position:0% +call me but he said just say I said it + + + align:start position:0% +call me but he said just say I said it +was fine because I was trying to get + + align:start position:0% +was fine because I was trying to get + + + align:start position:0% +was fine because I was trying to get +access to the National Guard because I + + align:start position:0% +access to the National Guard because I + + + align:start position:0% +access to the National Guard because I +couldn't get into the ninth ward so I + + align:start position:0% +couldn't get into the ninth ward so I + + + align:start position:0% +couldn't get into the ninth ward so I +got a call so at the end of the 5 days + + align:start position:0% +got a call so at the end of the 5 days + + + align:start position:0% +got a call so at the end of the 5 days +when I was really pretty burned out + + align:start position:0% +when I was really pretty burned out + + + align:start position:0% +when I was really pretty burned out +saying you want want to be embedded with + + align:start position:0% +saying you want want to be embedded with + + + align:start position:0% +saying you want want to be embedded with +the National Guard and I said hell yes + + align:start position:0% +the National Guard and I said hell yes + + + align:start position:0% +the National Guard and I said hell yes +uh I couldn't help but obviously + + align:start position:0% +uh I couldn't help but obviously + + + align:start position:0% +uh I couldn't help but obviously +thinking about other situations where + + align:start position:0% +thinking about other situations where + + + align:start position:0% +thinking about other situations where +embedding was going on there's a lot I + + align:start position:0% +embedding was going on there's a lot I + + + align:start position:0% +embedding was going on there's a lot I +thought about Iraq a lot while I was in + + align:start position:0% +thought about Iraq a lot while I was in + + + align:start position:0% +thought about Iraq a lot while I was in +New Orleans so I won't I'll spare you + + align:start position:0% +New Orleans so I won't I'll spare you + + + align:start position:0% +New Orleans so I won't I'll spare you +the picture of me posing with an M16 but + + align:start position:0% +the picture of me posing with an M16 but + + + align:start position:0% +the picture of me posing with an M16 but +these were the 18 and 19 year old kids + + align:start position:0% +these were the 18 and 19 year old kids + + + align:start position:0% +these were the 18 and 19 year old kids +some of whom would just come back from + + align:start position:0% +some of whom would just come back from + + + align:start position:0% +some of whom would just come back from +Iraq and who said New Orleans was much + + align:start position:0% +Iraq and who said New Orleans was much + + + align:start position:0% +Iraq and who said New Orleans was much +more upsetting to them than Iraq was but + + align:start position:0% +more upsetting to them than Iraq was but + + + align:start position:0% +more upsetting to them than Iraq was but +and who were not allowed to leave this + + align:start position:0% +and who were not allowed to leave this + + + align:start position:0% +and who were not allowed to leave this +uh Monastery where they were staying uh + + align:start position:0% +uh Monastery where they were staying uh + + + align:start position:0% +uh Monastery where they were staying uh +the a Convent where they were staying so + + align:start position:0% +the a Convent where they were staying so + + + align:start position:0% +the a Convent where they were staying so +many of them knew nothing about New + + align:start position:0% +many of them knew nothing about New + + + align:start position:0% +many of them knew nothing about New +Orleans they knew they were patrolling + + align:start position:0% +Orleans they knew they were patrolling + + + align:start position:0% +Orleans they knew they were patrolling +the ninth ward but they had not been to + + align:start position:0% +the ninth ward but they had not been to + + + align:start position:0% +the ninth ward but they had not been to +the French + + align:start position:0% +the French + + + align:start position:0% +the French +Quarter + + align:start position:0% +Quarter + + + align:start position:0% +Quarter +um it was interesting that a couple of + + align:start position:0% +um it was interesting that a couple of + + + align:start position:0% +um it was interesting that a couple of +the people when I asked if I could + + align:start position:0% +the people when I asked if I could + + + align:start position:0% +the people when I asked if I could +photograph a couple of these guys says + + align:start position:0% +photograph a couple of these guys says + + + align:start position:0% +photograph a couple of these guys says +no way and the other one said we're not + + align:start position:0% +no way and the other one said we're not + + + align:start position:0% +no way and the other one said we're not +going to pose for you but go + + align:start position:0% +going to pose for you but go + + + align:start position:0% +going to pose for you but go +ahead that's when I knew maybe I was + + align:start position:0% +ahead that's when I knew maybe I was + + + align:start position:0% +ahead that's when I knew maybe I was +onto something a lot of uh private + + align:start position:0% +onto something a lot of uh private + + + align:start position:0% +onto something a lot of uh private +Securities of blackwat um a lot of + + align:start position:0% +Securities of blackwat um a lot of + + + align:start position:0% +Securities of blackwat um a lot of +people walking around with guns on their + + align:start position:0% +people walking around with guns on their + + + align:start position:0% +people walking around with guns on their +hips this is on Canal Street + + align:start position:0% +hips this is on Canal Street + + + align:start position:0% +hips this is on Canal Street +so here's I did get into the the lower + + align:start position:0% + + + + align:start position:0% + +9th this was literally right by the + + align:start position:0% +9th this was literally right by the + + + align:start position:0% +9th this was literally right by the +barge I'm not going to show the barge + + align:start position:0% +barge I'm not going to show the barge + + + align:start position:0% +barge I'm not going to show the barge +but there there was a lot of evidence um + + align:start position:0% +but there there was a lot of evidence um + + + align:start position:0% +but there there was a lot of evidence um +you're going to see some work in a + + align:start position:0% +you're going to see some work in a + + + align:start position:0% +you're going to see some work in a +couple of weeks of someone who really + + align:start position:0% +couple of weeks of someone who really + + + align:start position:0% +couple of weeks of someone who really +concentrated on kind of + + align:start position:0% +concentrated on kind of + + + align:start position:0% +concentrated on kind of +ephemera uh in New Orleans someone who + + align:start position:0% +ephemera uh in New Orleans someone who + + + align:start position:0% +ephemera uh in New Orleans someone who +was sitting in this + + align:start position:0% +was sitting in this + + + align:start position:0% +was sitting in this +room that uh this the foundation of the + + align:start position:0% +room that uh this the foundation of the + + + align:start position:0% +room that uh this the foundation of the +house that's behind it the the flood + + align:start position:0% +house that's behind it the the flood + + + align:start position:0% +house that's behind it the the flood +complet it kept it intact but moved it + + align:start position:0% +complet it kept it intact but moved it + + + align:start position:0% +complet it kept it intact but moved it +um half a + + align:start position:0% + + + + align:start position:0% + +block so when I was there I actually + + align:start position:0% +block so when I was there I actually + + + align:start position:0% +block so when I was there I actually +they didn't open up the city till the + + align:start position:0% +they didn't open up the city till the + + + align:start position:0% +they didn't open up the city till the +standing water was gone so I didn't see + + align:start position:0% +standing water was gone so I didn't see + + + align:start position:0% +standing water was gone so I didn't see +standing water in New Orleans this is a + + align:start position:0% +standing water in New Orleans this is a + + + align:start position:0% +standing water in New Orleans this is a +picture I took in 1994 on the River Road + + align:start position:0% +picture I took in 1994 on the River Road + + + align:start position:0% +picture I took in 1994 on the River Road +during a tropical rainstorm and this is + + align:start position:0% +during a tropical rainstorm and this is + + + align:start position:0% +during a tropical rainstorm and this is +a picture I took leaving the 9th Ward + + align:start position:0% +a picture I took leaving the 9th Ward + + + align:start position:0% +a picture I took leaving the 9th Ward +the first day they allowed people to + + align:start position:0% +the first day they allowed people to + + + align:start position:0% +the first day they allowed people to +drive in they had a fir truck that was + + align:start position:0% +drive in they had a fir truck that was + + + align:start position:0% +drive in they had a fir truck that was +rinsing off the cars it literally when + + align:start position:0% +rinsing off the cars it literally when + + + align:start position:0% +rinsing off the cars it literally when +you walked out of the the um got out of + + align:start position:0% +you walked out of the the um got out of + + + align:start position:0% +you walked out of the the um got out of +the car in the ninth ward even with a + + align:start position:0% +the car in the ninth ward even with a + + + align:start position:0% +the car in the ninth ward even with a +mask on I would get nauseous the the + + align:start position:0% +mask on I would get nauseous the the + + + align:start position:0% +mask on I would get nauseous the the +dust was uh and I think I I understand + + align:start position:0% +dust was uh and I think I I understand + + + align:start position:0% +dust was uh and I think I I understand +it's um becoming an issue for people + + align:start position:0% +it's um becoming an issue for people + + + align:start position:0% +it's um becoming an issue for people +that are + + align:start position:0% +that are + + + align:start position:0% +that are +there here's a photograph I took um in + + align:start position:0% +there here's a photograph I took um in + + + align:start position:0% +there here's a photograph I took um in +the lunchroom in New Orleans about 5 + + align:start position:0% +the lunchroom in New Orleans about 5 + + + align:start position:0% +the lunchroom in New Orleans about 5 +years ago and I thought it was interest + + align:start position:0% +years ago and I thought it was interest + + + align:start position:0% +years ago and I thought it was interest +well no it was after + + align:start position:0% +well no it was after + + + align:start position:0% +well no it was after +911 um and in fact some people think + + align:start position:0% +911 um and in fact some people think + + + align:start position:0% +911 um and in fact some people think +it's supposed to be a representation of + + align:start position:0% +it's supposed to be a representation of + + + align:start position:0% +it's supposed to be a representation of +New York it's actually someone trying to + + align:start position:0% +New York it's actually someone trying to + + + align:start position:0% +New York it's actually someone trying to +make the skyline of New Orleans look + + align:start position:0% +make the skyline of New Orleans look + + + align:start position:0% +make the skyline of New Orleans look +like um New York and I thought it was + + align:start position:0% +like um New York and I thought it was + + + align:start position:0% +like um New York and I thought it was +interesting that um uh the sort of + + align:start position:0% +interesting that um uh the sort of + + + align:start position:0% +interesting that um uh the sort of +notion of New Orleans and disaster this + + align:start position:0% +notion of New Orleans and disaster this + + + align:start position:0% +notion of New Orleans and disaster this +was kind of a reference to another + + align:start position:0% +was kind of a reference to another + + + align:start position:0% +was kind of a reference to another +disaster was kind of manifested in this + + align:start position:0% +disaster was kind of manifested in this + + + align:start position:0% +disaster was kind of manifested in this +kind of trump little um uh + + align:start position:0% +kind of trump little um uh + + + align:start position:0% +kind of trump little um uh +mural so I + + align:start position:0% +mural so I + + + align:start position:0% +mural so I +think that is + + align:start position:0% +think that is + + + align:start position:0% +think that is +it and I'd be very curious if anybody + + align:start position:0% +it and I'd be very curious if anybody + + + align:start position:0% +it and I'd be very curious if anybody +has questions or or comments um it was + + align:start position:0% +has questions or or comments um it was + + + align:start position:0% +has questions or or comments um it was +interesting to put this show together + + align:start position:0% +interesting to put this show together + + + align:start position:0% +interesting to put this show together +because uh a I'm sort of realizing how + + align:start position:0% +because uh a I'm sort of realizing how + + + align:start position:0% +because uh a I'm sort of realizing how +much of my work I haven't gotten to + + align:start position:0% +much of my work I haven't gotten to + + + align:start position:0% +much of my work I haven't gotten to +digitized yet and the there's a certain + + align:start position:0% +digitized yet and the there's a certain + + + align:start position:0% +digitized yet and the there's a certain +thread but but things have changed um + + align:start position:0% +thread but but things have changed um + + + align:start position:0% +thread but but things have changed um +and some things that I kind of felt I + + align:start position:0% +and some things that I kind of felt I + + + align:start position:0% +and some things that I kind of felt I +was pretty clear about became less clear + + align:start position:0% +was pretty clear about became less clear + + + align:start position:0% +was pretty clear about became less clear +as I was putting some work today there's + + align:start position:0% +as I was putting some work today there's + + + align:start position:0% +as I was putting some work today there's +other things I'm I'm pretty clear about + + align:start position:0% +other things I'm I'm pretty clear about + + + align:start position:0% +other things I'm I'm pretty clear about +in terms of way I'm working but I'm I'm + + align:start position:0% +in terms of way I'm working but I'm I'm + + + align:start position:0% +in terms of way I'm working but I'm I'm +interested in your reactions or if + + align:start position:0% +interested in your reactions or if + + + align:start position:0% +interested in your reactions or if +anybody has questions + + align:start position:0% + + + + align:start position:0% + +or if people are ready to eat + + align:start position:0% + + + + align:start position:0% + +whatever well maybe I'll just use the7 + + align:start position:0% +whatever well maybe I'll just use the7 + + + align:start position:0% +whatever well maybe I'll just use the7 +foring I thought that folks might I'm + + align:start position:0% +foring I thought that folks might I'm + + + align:start position:0% +foring I thought that folks might I'm +interested soes you're using photography + + align:start position:0% +interested soes you're using photography + + + align:start position:0% +interested soes you're using photography +a certain way as investigation + + align:start position:0% + + + + align:start position:0% + +what + + align:start position:0% +what + + + align:start position:0% +what +youan + + align:start position:0% +youan + + + align:start position:0% +youan +you I have to how you contr that + + align:start position:0% +you I have to how you contr that + + + align:start position:0% +you I have to how you contr that +whatever else you + + align:start position:0% +whatever else you + + + align:start position:0% +whatever else you +were well I think the probably the most + + align:start position:0% +were well I think the probably the most + + + align:start position:0% +were well I think the probably the most +boring thing I can imagine and there's a + + align:start position:0% +boring thing I can imagine and there's a + + + align:start position:0% +boring thing I can imagine and there's a +lot of people that do it and a lot of + + align:start position:0% +lot of people that do it and a lot of + + + align:start position:0% +lot of people that do it and a lot of +people get pleasure that they' like to + + align:start position:0% +people get pleasure that they' like to + + + align:start position:0% +people get pleasure that they' like to +talk about equipment in fact there + + align:start position:0% +talk about equipment in fact there + + + align:start position:0% +talk about equipment in fact there +there's a great it doesn't exist anymore + + align:start position:0% +there's a great it doesn't exist anymore + + + align:start position:0% +there's a great it doesn't exist anymore +there's this famous swap meat in um uh + + align:start position:0% +there's this famous swap meat in um uh + + + align:start position:0% +there's this famous swap meat in um uh +Oakland that was every Sunday it was + + align:start position:0% +Oakland that was every Sunday it was + + + align:start position:0% +Oakland that was every Sunday it was +always a great place to find used + + align:start position:0% +always a great place to find used + + + align:start position:0% +always a great place to find used +equipment but there were people that go + + align:start position:0% +equipment but there were people that go + + + align:start position:0% +equipment but there were people that go +every day and they never took a picture + + align:start position:0% +every day and they never took a picture + + + align:start position:0% +every day and they never took a picture +all they did was talk about equipment + + align:start position:0% +all they did was talk about equipment + + + align:start position:0% +all they did was talk about equipment +but I do think that the tool I really + + align:start position:0% +but I do think that the tool I really + + + align:start position:0% +but I do think that the tool I really +feel it's important the tools you use + + align:start position:0% +feel it's important the tools you use + + + align:start position:0% +feel it's important the tools you use +are very important I um I think I bought + + align:start position:0% +are very important I um I think I bought + + + align:start position:0% +are very important I um I think I bought +a couple times cameras with autofocus + + align:start position:0% +a couple times cameras with autofocus + + + align:start position:0% +a couple times cameras with autofocus +and zooms and and couldn't use them you + + align:start position:0% +and zooms and and couldn't use them you + + + align:start position:0% +and zooms and and couldn't use them you +know I I knew I could tell I mean I + + align:start position:0% +know I I knew I could tell I mean I + + + align:start position:0% +know I I knew I could tell I mean I +would borrow them or rent them um the + + align:start position:0% +would borrow them or rent them um the + + + align:start position:0% +would borrow them or rent them um the +sort of more help I have seeing the + + align:start position:0% +sort of more help I have seeing the + + + align:start position:0% +sort of more help I have seeing the +worse I see it's changed a little bit + + align:start position:0% +worse I see it's changed a little bit + + + align:start position:0% +worse I see it's changed a little bit +cuz my eyesight is left but so I had a I + + align:start position:0% +cuz my eyesight is left but so I had a I + + + align:start position:0% +cuz my eyesight is left but so I had a I +had three lias and they were all stolen + + align:start position:0% +had three lias and they were all stolen + + + align:start position:0% +had three lias and they were all stolen +so I had this decision I am going to + + align:start position:0% +so I had this decision I am going to + + + align:start position:0% +so I had this decision I am going to +change cuz I love the lia but it was + + align:start position:0% +change cuz I love the lia but it was + + + align:start position:0% +change cuz I love the lia but it was +small It's too convenient so I'm going + + align:start position:0% +small It's too convenient so I'm going + + + align:start position:0% +small It's too convenient so I'm going +to get something that's more of a paint + + align:start position:0% +to get something that's more of a paint + + + align:start position:0% +to get something that's more of a paint +I also use a lot of the black and white + + align:start position:0% +I also use a lot of the black and white + + + align:start position:0% +I also use a lot of the black and white +I use a Fuji 6x9 which is called a Texas + + align:start position:0% +I use a Fuji 6x9 which is called a Texas + + + align:start position:0% +I use a Fuji 6x9 which is called a Texas +like it looks like a Leica on steroids + + align:start position:0% +like it looks like a Leica on steroids + + + align:start position:0% +like it looks like a Leica on steroids +it's a rangefinder that shoots 6x9 + + align:start position:0% +it's a rangefinder that shoots 6x9 + + + align:start position:0% +it's a rangefinder that shoots 6x9 +images uh so I like it because it's the + + align:start position:0% +images uh so I like it because it's the + + + align:start position:0% +images uh so I like it because it's the +biggest negative I can make hand holding + + align:start position:0% +biggest negative I can make hand holding + + + align:start position:0% +biggest negative I can make hand holding +without using a a view uh like a press + + align:start position:0% +without using a a view uh like a press + + + align:start position:0% +without using a a view uh like a press +camera um but I finally found the this + + align:start position:0% +camera um but I finally found the this + + + align:start position:0% +camera um but I finally found the this +Nikon and Canon and a couple other + + align:start position:0% +Nikon and Canon and a couple other + + + align:start position:0% +Nikon and Canon and a couple other +people made digital cameras for people + + align:start position:0% +people made digital cameras for people + + + align:start position:0% +people made digital cameras for people +like me because the one thing I did not + + align:start position:0% +like me because the one thing I did not + + + align:start position:0% +like me because the one thing I did not +could not tolerate was pushing the + + align:start position:0% +could not tolerate was pushing the + + + align:start position:0% +could not tolerate was pushing the +shutter and it not going so most of the + + align:start position:0% +shutter and it not going so most of the + + + align:start position:0% +shutter and it not going so most of the +the newer generation cameras don't take + + align:start position:0% +the newer generation cameras don't take + + + align:start position:0% +the newer generation cameras don't take +long to recycle because the idea is I I + + align:start position:0% +long to recycle because the idea is I I + + + align:start position:0% +long to recycle because the idea is I I +want to take the picture when it's + + align:start position:0% +want to take the picture when it's + + + align:start position:0% +want to take the picture when it's +happening I don't want anything else to + + align:start position:0% +happening I don't want anything else to + + + align:start position:0% +happening I don't want anything else to +get in the way of that including + + align:start position:0% +get in the way of that including + + + align:start position:0% +get in the way of that including +autofocus so I actually surprisingly + + align:start position:0% +autofocus so I actually surprisingly + + + align:start position:0% +autofocus so I actually surprisingly +really like this camera it's a a a + + align:start position:0% +really like this camera it's a a a + + + align:start position:0% +really like this camera it's a a a +single lens reflex it looks like a film + + align:start position:0% +single lens reflex it looks like a film + + + align:start position:0% +single lens reflex it looks like a film +camera it came with a zoom lens I said + + align:start position:0% +camera it came with a zoom lens I said + + + align:start position:0% +camera it came with a zoom lens I said +and ideally I was going to be able to + + align:start position:0% +and ideally I was going to be able to + + + align:start position:0% +and ideally I was going to be able to +use my lenses you can but it doesn't + + align:start position:0% +use my lenses you can but it doesn't + + + align:start position:0% +use my lenses you can but it doesn't +translate I had you know fixed Focus + + align:start position:0% +translate I had you know fixed Focus + + + align:start position:0% +translate I had you know fixed Focus +lenses so I've been using it a lot in + + align:start position:0% +lenses so I've been using it a lot in + + + align:start position:0% +lenses so I've been using it a lot in +fact I use it exclusively for a while + + align:start position:0% +fact I use it exclusively for a while + + + align:start position:0% +fact I use it exclusively for a while +but I knew and and I use it to make a + + align:start position:0% +but I knew and and I use it to make a + + + align:start position:0% +but I knew and and I use it to make a +living I do a lot of architectural + + align:start position:0% +living I do a lot of architectural + + + align:start position:0% +living I do a lot of architectural +photography it's great I can make give + + align:start position:0% +photography it's great I can make give + + + align:start position:0% +photography it's great I can make give +files that the Architects can use I use + + align:start position:0% +files that the Architects can use I use + + + align:start position:0% +files that the Architects can use I use +it for architectural Pres + + align:start position:0% +it for architectural Pres + + + align:start position:0% +it for architectural Pres +reservation um and so it's I know it's + + align:start position:0% +reservation um and so it's I know it's + + + align:start position:0% +reservation um and so it's I know it's +part of + + align:start position:0% +part of + + + align:start position:0% +part of +my no that's not not taking that's that + + align:start position:0% +my no that's not not taking that's that + + + align:start position:0% +my no that's not not taking that's that +is using it on this trip my + + align:start position:0% +is using it on this trip my + + + align:start position:0% +is using it on this trip my +rationalization was I would use the + + align:start position:0% +rationalization was I would use the + + + align:start position:0% +rationalization was I would use the +digital camera to get instant feedback + + align:start position:0% +digital camera to get instant feedback + + + align:start position:0% +digital camera to get instant feedback +to make pictures that were good but the + + align:start position:0% +to make pictures that were good but the + + + align:start position:0% +to make pictures that were good but the +real serious photographs would be in + + align:start position:0% +real serious photographs would be in + + + align:start position:0% +real serious photographs would be in +black and white but you know sometime it + + align:start position:0% +black and white but you know sometime it + + + align:start position:0% +black and white but you know sometime it +depend on which camera I had in my hands + + align:start position:0% +depend on which camera I had in my hands + + + align:start position:0% +depend on which camera I had in my hands +they got in each other's way in that way + + align:start position:0% +they got in each other's way in that way + + + align:start position:0% +they got in each other's way in that way +so in terms of that kind of work this + + align:start position:0% +so in terms of that kind of work this + + + align:start position:0% +so in terms of that kind of work this +kind of my own personal investigation I + + align:start position:0% +kind of my own personal investigation I + + + align:start position:0% +kind of my own personal investigation I +have some decisions to make um and so in + + align:start position:0% +have some decisions to make um and so in + + + align:start position:0% +have some decisions to make um and so in +that case either I'll leave the digital + + align:start position:0% +that case either I'll leave the digital + + + align:start position:0% +that case either I'll leave the digital +at home and just shoot film or keep it + + align:start position:0% +at home and just shoot film or keep it + + + align:start position:0% +at home and just shoot film or keep it +in the bag and and shoot more film + + align:start position:0% +in the bag and and shoot more film + + + align:start position:0% +in the bag and and shoot more film +because what happened was there's some + + align:start position:0% +because what happened was there's some + + + align:start position:0% +because what happened was there's some +pictures that I should have taken in + + align:start position:0% +pictures that I should have taken in + + + align:start position:0% +pictures that I should have taken in +black and white that didn't exist + + align:start position:0% +black and white that didn't exist + + + align:start position:0% +black and white that didn't exist +anymore so that's but I you know I I'm + + align:start position:0% +anymore so that's but I you know I I'm + + + align:start position:0% +anymore so that's but I you know I I'm +not the other alternative would be to + + align:start position:0% +not the other alternative would be to + + + align:start position:0% +not the other alternative would be to +get a + + align:start position:0% +get a + + + align:start position:0% +get a +$3,000 you know 20 megapixel digital + + align:start position:0% +$3,000 you know 20 megapixel digital + + + align:start position:0% +$3,000 you know 20 megapixel digital +camera and then cuz what I want to do be + + align:start position:0% +camera and then cuz what I want to do be + + + align:start position:0% +camera and then cuz what I want to do be +able to make big pictures my question + + align:start position:0% +able to make big pictures my question + + + align:start position:0% +able to make big pictures my question +wasn't really + + align:start position:0% +wasn't really + + + align:start position:0% +wasn't really +directed direct what of research right + + align:start position:0% +directed direct what of research right + + + align:start position:0% +directed direct what of research right +what is + + align:start position:0% +what is + + + align:start position:0% +what is +it how does photography take you I I + + align:start position:0% +it how does photography take you I I + + + align:start position:0% +it how does photography take you I I +want the materials and the medium to be + + align:start position:0% +want the materials and the medium to be + + + align:start position:0% +want the materials and the medium to be +as close to translating my ideas as + + align:start position:0% +as close to translating my ideas as + + + align:start position:0% +as close to translating my ideas as +possible there are sometimes when + + align:start position:0% +possible there are sometimes when + + + align:start position:0% +possible there are sometimes when +digital does do that and sometimes when + + align:start position:0% +digital does do that and sometimes when + + + align:start position:0% +digital does do that and sometimes when +it absolutely does not and I don't know + + align:start position:0% +it absolutely does not and I don't know + + + align:start position:0% +it absolutely does not and I don't know +if I can be any clearer than that I it + + align:start position:0% +if I can be any clearer than that I it + + + align:start position:0% +if I can be any clearer than that I it +is you know I kept saying oh I hate + + align:start position:0% +is you know I kept saying oh I hate + + + align:start position:0% +is you know I kept saying oh I hate +technology I'm a lead eyem of course + + align:start position:0% +technology I'm a lead eyem of course + + + align:start position:0% +technology I'm a lead eyem of course +this is as I'm trying to find my Palm + + align:start position:0% +this is as I'm trying to find my Palm + + + align:start position:0% +this is as I'm trying to find my Palm +Pilot and my you know so that that's + + align:start position:0% +Pilot and my you know so that that's + + + align:start position:0% +Pilot and my you know so that that's +obviously not the case and um we were + + align:start position:0% +obviously not the case and um we were + + + align:start position:0% +obviously not the case and um we were +talking about it whatever I have usually + + align:start position:0% +talking about it whatever I have usually + + + align:start position:0% +talking about it whatever I have usually +I learn whatever else I can do when I + + align:start position:0% +I learn whatever else I can do when I + + + align:start position:0% +I learn whatever else I can do when I +need to do it and I think that's that's + + align:start position:0% +need to do it and I think that's that's + + + align:start position:0% +need to do it and I think that's that's +the case in terms of Photography um + + align:start position:0% +the case in terms of Photography um + + + align:start position:0% +the case in terms of Photography um +so I think maybe ultimately every + + align:start position:0% +so I think maybe ultimately every + + + align:start position:0% +so I think maybe ultimately every +picture I take is note taking and I need + + align:start position:0% +picture I take is note taking and I need + + + align:start position:0% +picture I take is note taking and I need +to find a variety I want the sort of + + align:start position:0% +to find a variety I want the sort of + + + align:start position:0% +to find a variety I want the sort of +ways to + + align:start position:0% +ways to + + + align:start position:0% +ways to +translate my reaction into things I mean + + align:start position:0% +translate my reaction into things I mean + + + align:start position:0% +translate my reaction into things I mean +I use the camera we've talked about that + + align:start position:0% +I use the camera we've talked about that + + + align:start position:0% +I use the camera we've talked about that +the camera really is my excuse to go + + align:start position:0% +the camera really is my excuse to go + + + align:start position:0% +the camera really is my excuse to go +into places I have no business in being + + align:start position:0% +into places I have no business in being + + + align:start position:0% +into places I have no business in being +and so I want the tool I use that + + align:start position:0% +and so I want the tool I use that + + + align:start position:0% +and so I want the tool I use that +records that experience to be something + + align:start position:0% +records that experience to be something + + + align:start position:0% +records that experience to be something +I feel comfortable with and that does + + align:start position:0% +I feel comfortable with and that does + + + align:start position:0% +I feel comfortable with and that does +what I want to do it in the case of the + + align:start position:0% +what I want to do it in the case of the + + + align:start position:0% +what I want to do it in the case of the +medium format camera allows me if I scan + + align:start position:0% +medium format camera allows me if I scan + + + align:start position:0% +medium format camera allows me if I scan +them to be able to I can make 45 48 in + + align:start position:0% +them to be able to I can make 45 48 in + + + align:start position:0% +them to be able to I can make 45 48 in +prints if I want it's harder I can't do + + align:start position:0% +prints if I want it's harder I can't do + + + align:start position:0% +prints if I want it's harder I can't do +that with a d70 because it's too it + + align:start position:0% +that with a d70 because it's too it + + + align:start position:0% +that with a d70 because it's too it +makes too small a file + + align:start position:0% +makes too small a file + + + align:start position:0% +makes too small a file +so I don't you know I'm doing the very + + align:start position:0% +so I don't you know I'm doing the very + + + align:start position:0% +so I don't you know I'm doing the very +thing I said I don't like but it's I I'm + + align:start position:0% +thing I said I don't like but it's I I'm + + + align:start position:0% +thing I said I don't like but it's I I'm +kind of into talking about the tools + + align:start position:0% +kind of into talking about the tools + + + align:start position:0% +kind of into talking about the tools +enough that so I know if there's + + align:start position:0% +enough that so I know if there's + + + align:start position:0% +enough that so I know if there's +something else I can use that will allow + + align:start position:0% +something else I can use that will allow + + + align:start position:0% +something else I can use that will allow +me to do what I need to I will uh I'll + + align:start position:0% +me to do what I need to I will uh I'll + + + align:start position:0% +me to do what I need to I will uh I'll +I'll get that or I'll find out about it + + align:start position:0% +I'll get that or I'll find out about it + + + align:start position:0% +I'll get that or I'll find out about it +or in a lot of cases I'll ask one of my + + align:start position:0% +or in a lot of cases I'll ask one of my + + + align:start position:0% +or in a lot of cases I'll ask one of my +students about it because they may know + + align:start position:0% +students about it because they may know + + + align:start position:0% +students about it because they may know +more about it than I + + align:start position:0% + + + + align:start position:0% + +do yes I'm curious about uh sort of this + + align:start position:0% +do yes I'm curious about uh sort of this + + + align:start position:0% +do yes I'm curious about uh sort of this +act of like recognition + + align:start position:0% +act of like recognition + + + align:start position:0% +act of like recognition +sort of like you know here's the + + align:start position:0% +sort of like you know here's the + + + align:start position:0% +sort of like you know here's the +hometown of Zer hen or here's the block + + align:start position:0% +hometown of Zer hen or here's the block + + + align:start position:0% +hometown of Zer hen or here's the block +next to where Sam Cooks was killed or + + align:start position:0% +next to where Sam Cooks was killed or + + + align:start position:0% +next to where Sam Cooks was killed or +this is where FS Domino's hous it's + + align:start position:0% +this is where FS Domino's hous it's + + + align:start position:0% +this is where FS Domino's hous it's +almost like there's a certain sort of + + align:start position:0% +almost like there's a certain sort of + + + align:start position:0% +almost like there's a certain sort of +cultural Consciousness that these places + + align:start position:0% +cultural Consciousness that these places + + + align:start position:0% +cultural Consciousness that these places +sort of Blossom from and kind of + + align:start position:0% +sort of Blossom from and kind of + + + align:start position:0% +sort of Blossom from and kind of +recording that with the camera I'm + + align:start position:0% +recording that with the camera I'm + + + align:start position:0% +recording that with the camera I'm +curious to talk about that because it's + + align:start position:0% +curious to talk about that because it's + + + align:start position:0% +curious to talk about that because it's +it's one way to kind of Define the + + align:start position:0% +it's one way to kind of Define the + + + align:start position:0% +it's one way to kind of Define the +really complete um sort of idea of + + align:start position:0% +really complete um sort of idea of + + + align:start position:0% +really complete um sort of idea of +culture uh by + + align:start position:0% +culture uh by + + + align:start position:0% +culture uh by +moving I how that differs from Oakland + + align:start position:0% +moving I how that differs from Oakland + + + align:start position:0% +moving I how that differs from Oakland +looking around Oakland well you know I I + + align:start position:0% +looking around Oakland well you know I I + + + align:start position:0% +looking around Oakland well you know I I +sort of like to say well I just go plac + + align:start position:0% +sort of like to say well I just go plac + + + align:start position:0% +sort of like to say well I just go plac +and react to place but I + + align:start position:0% +and react to place but I + + + align:start position:0% +and react to place but I +very directed and structured the places + + align:start position:0% +very directed and structured the places + + + align:start position:0% +very directed and structured the places +I go to then riff if I am riffing I mean + + align:start position:0% +I go to then riff if I am riffing I mean + + + align:start position:0% +I go to then riff if I am riffing I mean +in other words I place myself in a + + align:start position:0% +in other words I place myself in a + + + align:start position:0% +in other words I place myself in a +particular situation and then react to S + + align:start position:0% +particular situation and then react to S + + + align:start position:0% +particular situation and then react to S +circumstances uh I know in um a lot of + + align:start position:0% +circumstances uh I know in um a lot of + + + align:start position:0% +circumstances uh I know in um a lot of +communities of color I'm going to find + + align:start position:0% +communities of color I'm going to find + + + align:start position:0% +communities of color I'm going to find +examples of + + align:start position:0% +examples of + + + align:start position:0% +examples of +improvisation um I'm also going to find + + align:start position:0% +improvisation um I'm also going to find + + + align:start position:0% +improvisation um I'm also going to find +out sort of things like in the Third + + align:start position:0% +out sort of things like in the Third + + + align:start position:0% +out sort of things like in the Third +Ward um that lot is where lightning + + align:start position:0% +Ward um that lot is where lightning + + + align:start position:0% +Ward um that lot is where lightning +Hopkins was raised and that's + + align:start position:0% +Hopkins was raised and that's + + + align:start position:0% +Hopkins was raised and that's +interesting to me because it tells me a + + align:start position:0% +interesting to me because it tells me a + + + align:start position:0% +interesting to me because it tells me a +little bit about um I mean it's sort of + + align:start position:0% +little bit about um I mean it's sort of + + + align:start position:0% +little bit about um I mean it's sort of +thrilling to me I have some problems + + align:start position:0% +thrilling to me I have some problems + + + align:start position:0% +thrilling to me I have some problems +with the South and actually I can + + align:start position:0% +with the South and actually I can + + + align:start position:0% +with the South and actually I can +usually only be in the South for about + + align:start position:0% +usually only be in the South for about + + + align:start position:0% +usually only be in the South for about +two weeks at a time but I keep going + + align:start position:0% +two weeks at a time but I keep going + + + align:start position:0% +two weeks at a time but I keep going +back uh because the south is a very + + align:start position:0% +back uh because the south is a very + + + align:start position:0% +back uh because the south is a very +Dynamic area on a lot of different + + align:start position:0% +Dynamic area on a lot of different + + + align:start position:0% +Dynamic area on a lot of different +levels but kind of those those + + align:start position:0% +levels but kind of those those + + + align:start position:0% +levels but kind of those those +manifestations of culture are real + + align:start position:0% +manifestations of culture are real + + + align:start position:0% +manifestations of culture are real +important because they they sort of give + + align:start position:0% +important because they they sort of give + + + align:start position:0% +important because they they sort of give +me they sort of help inform me in terms + + align:start position:0% +me they sort of help inform me in terms + + + align:start position:0% +me they sort of help inform me in terms +of kind of the things I'm reacting to + + align:start position:0% +of kind of the things I'm reacting to + + + align:start position:0% +of kind of the things I'm reacting to +maybe not as instinctively I'd like to + + align:start position:0% +maybe not as instinctively I'd like to + + + align:start position:0% +maybe not as instinctively I'd like to +State a and so uh sometimes I find those + + align:start position:0% +State a and so uh sometimes I find those + + + align:start position:0% +State a and so uh sometimes I find those +things after the fact sometimes I find + + align:start position:0% +things after the fact sometimes I find + + + align:start position:0% +things after the fact sometimes I find +them in the course the the the act of + + align:start position:0% +them in the course the the the act of + + + align:start position:0% +them in the course the the the act of +photographing opens up the conversation + + align:start position:0% +photographing opens up the conversation + + + align:start position:0% +photographing opens up the conversation +you know people say so what are you + + align:start position:0% +you know people say so what are you + + + align:start position:0% +you know people say so what are you +doing and I'll say I'm you know real + + align:start position:0% +doing and I'll say I'm you know real + + + align:start position:0% +doing and I'll say I'm you know real +interested in kind of finding + + align:start position:0% +interested in kind of finding + + + align:start position:0% +interested in kind of finding +reflections of culture and history you + + align:start position:0% +reflections of culture and history you + + + align:start position:0% +reflections of culture and history you +know in this block and someone say well + + align:start position:0% +know in this block and someone say well + + + align:start position:0% +know in this block and someone say well +you know so and so used to be there or + + align:start position:0% +you know so and so used to be there or + + + align:start position:0% +you know so and so used to be there or +you should knock on that door + + align:start position:0% +you should knock on that door + + + align:start position:0% +you should knock on that door +it it opens up things and some of the + + align:start position:0% +it it opens up things and some of the + + + align:start position:0% +it it opens up things and some of the +stories are you know kind of uh kind of + + align:start position:0% +stories are you know kind of uh kind of + + + align:start position:0% +stories are you know kind of uh kind of +national significance and some of them + + align:start position:0% +national significance and some of them + + + align:start position:0% +national significance and some of them +and probably more interesting or are + + align:start position:0% +and probably more interesting or are + + + align:start position:0% +and probably more interesting or are +personal so it's kind of both an excuse + + align:start position:0% +personal so it's kind of both an excuse + + + align:start position:0% +personal so it's kind of both an excuse +and the the vehicle by which + + align:start position:0% +and the the vehicle by which + + + align:start position:0% +and the the vehicle by which +I um can both Drive the work and can + + align:start position:0% +I um can both Drive the work and can + + + align:start position:0% +I um can both Drive the work and can +inform the sort of aesthetic decisions + + align:start position:0% +inform the sort of aesthetic decisions + + + align:start position:0% +inform the sort of aesthetic decisions +I'm making I think that answers it yes + + align:start position:0% +I'm making I think that answers it yes + + + align:start position:0% +I'm making I think that answers it yes +began this series of with the + + align:start position:0% +began this series of with the + + + align:start position:0% +began this series of with the +photographer who shoots from the air + + align:start position:0% +photographer who shoots from the air + + + align:start position:0% +photographer who shoots from the air +gentleman and we had a photographer who + + align:start position:0% +gentleman and we had a photographer who + + + align:start position:0% +gentleman and we had a photographer who +always looks at the high point of a city + + align:start position:0% +always looks at the high point of a city + + + align:start position:0% +always looks at the high point of a city +and takes an image + + align:start position:0% +and takes an image + + + align:start position:0% +and takes an image +downar looking at + + align:start position:0% +downar looking at + + + align:start position:0% +downar looking at +the photographs in New Jersey and I'm + + align:start position:0% +the photographs in New Jersey and I'm + + + align:start position:0% +the photographs in New Jersey and I'm +wondering if if you ever have + + align:start position:0% +wondering if if you ever have + + + align:start position:0% +wondering if if you ever have +a a tendency or a wish to photograph + + align:start position:0% +a a tendency or a wish to photograph + + + align:start position:0% +a a tendency or a wish to photograph +from on high uh or whether the subject + + align:start position:0% +from on high uh or whether the subject + + + align:start position:0% +from on high uh or whether the subject +matter that you take is always uh with + + align:start position:0% +matter that you take is always uh with + + + align:start position:0% +matter that you take is always uh with +your feet on the ground I think my + + align:start position:0% +your feet on the ground I think my + + + align:start position:0% +your feet on the ground I think my +tendency is I want to get as close to it + + align:start position:0% +tendency is I want to get as close to it + + + align:start position:0% +tendency is I want to get as close to it +as possible I don't like telephoto + + align:start position:0% +as possible I don't like telephoto + + + align:start position:0% +as possible I don't like telephoto +lenses I don't photograph with them very + + align:start position:0% +lenses I don't photograph with them very + + + align:start position:0% +lenses I don't photograph with them very +well I know people that photograph + + align:start position:0% +well I know people that photograph + + + align:start position:0% +well I know people that photograph +really well I need to have be sort of in + + align:start position:0% +really well I need to have be sort of in + + + align:start position:0% +really well I need to have be sort of in +physical contact with what I photograph + + align:start position:0% +physical contact with what I photograph + + + align:start position:0% +physical contact with what I photograph +I mean I do and I do like if I can get + + align:start position:0% +I mean I do and I do like if I can get + + + align:start position:0% +I mean I do and I do like if I can get +to a place where I can kind of see more + + align:start position:0% +to a place where I can kind of see more + + + align:start position:0% +to a place where I can kind of see more +context I will do that but I think my + + align:start position:0% +context I will do that but I think my + + + align:start position:0% +context I will do that but I think my +first inclination is to get close to + + align:start position:0% +first inclination is to get close to + + + align:start position:0% +first inclination is to get close to +something I think that shows in the work + + align:start position:0% +something I think that shows in the work + + + align:start position:0% +something I think that shows in the work +um I I'm kind of interested in the + + align:start position:0% +um I I'm kind of interested in the + + + align:start position:0% +um I I'm kind of interested in the +detail I'm very interested in the kind + + align:start position:0% +detail I'm very interested in the kind + + + align:start position:0% +detail I'm very interested in the kind +of bones of things and the texture + + align:start position:0% +of bones of things and the texture + + + align:start position:0% +of bones of things and the texture +uh both the sort of physical texture I + + align:start position:0% +uh both the sort of physical texture I + + + align:start position:0% +uh both the sort of physical texture I +actually hate when students say that yes + + align:start position:0% +actually hate when students say that yes + + + align:start position:0% +actually hate when students say that yes +I was really interested in but I am + + align:start position:0% +I was really interested in but I am + + + align:start position:0% +I was really interested in but I am +interested in that so I you know um but + + align:start position:0% +interested in that so I you know um but + + + align:start position:0% +interested in that so I you know um but +I'm interested in it for what it + + align:start position:0% +I'm interested in it for what it + + + align:start position:0% +I'm interested in it for what it +reflects the kind of you know that + + align:start position:0% +reflects the kind of you know that + + + align:start position:0% +reflects the kind of you know that +what's what always I loved about New + + align:start position:0% +what's what always I loved about New + + + align:start position:0% +what's what always I loved about New +Orleans is uh you know before the + + align:start position:0% +Orleans is uh you know before the + + + align:start position:0% +Orleans is uh you know before the +hurricane it already looks because it + + align:start position:0% +hurricane it already looks because it + + + align:start position:0% +hurricane it already looks because it +the climate is so hard that the patina + + align:start position:0% +the climate is so hard that the patina + + + align:start position:0% +the climate is so hard that the patina +of everything is just absolutely + + align:start position:0% +of everything is just absolutely + + + align:start position:0% +of everything is just absolutely +spectacular because it's there and so I + + align:start position:0% +spectacular because it's there and so I + + + align:start position:0% +spectacular because it's there and so I +I want to get close enough that that'll + + align:start position:0% +I want to get close enough that that'll + + + align:start position:0% +I want to get close enough that that'll +show in the photographs is there is + + align:start position:0% +show in the photographs is there is + + + align:start position:0% +show in the photographs is there is +there any kind of a setup shot I don't + + align:start position:0% +there any kind of a setup shot I don't + + + align:start position:0% +there any kind of a setup shot I don't +know what I mean something that gives + + align:start position:0% +know what I mean something that gives + + + align:start position:0% +know what I mean something that gives +you an entry point that is a larger + + align:start position:0% +you an entry point that is a larger + + + align:start position:0% +you an entry point that is a larger +context than the details that you find + + align:start position:0% +context than the details that you find + + + align:start position:0% +context than the details that you find +yeah I I I don't I think I like to have + + align:start position:0% +yeah I I I don't I think I like to have + + + align:start position:0% +yeah I I I don't I think I like to have +some hint of where something is or I'll + + align:start position:0% +some hint of where something is or I'll + + + align:start position:0% +some hint of where something is or I'll +at least do that in the photographs and + + align:start position:0% +at least do that in the photographs and + + + align:start position:0% +at least do that in the photographs and +then I have a decision to make you know + + align:start position:0% +then I have a decision to make you know + + + align:start position:0% +then I have a decision to make you know +whether I'm going to include that or not + + align:start position:0% +whether I'm going to include that or not + + + align:start position:0% +whether I'm going to include that or not +um uh you know sometimes I'll take one + + align:start position:0% +um uh you know sometimes I'll take one + + + align:start position:0% +um uh you know sometimes I'll take one +picture sort of whatever it feels like + + align:start position:0% +picture sort of whatever it feels like + + + align:start position:0% +picture sort of whatever it feels like +and leave but I think my tend my way of + + align:start position:0% +and leave but I think my tend my way of + + + align:start position:0% +and leave but I think my tend my way of +working usually is to kind of linger at + + align:start position:0% +working usually is to kind of linger at + + + align:start position:0% +working usually is to kind of linger at +a place and um kind of look at it from + + align:start position:0% +a place and um kind of look at it from + + + align:start position:0% +a place and um kind of look at it from +different areas angles or look at that + + align:start position:0% +different areas angles or look at that + + + align:start position:0% +different areas angles or look at that +phenomenon as it exists say in a number + + align:start position:0% +phenomenon as it exists say in a number + + + align:start position:0% +phenomenon as it exists say in a number +of different + + align:start position:0% + + + + align:start position:0% + +iterations yeah what's your personal + + align:start position:0% +iterations yeah what's your personal + + + align:start position:0% +iterations yeah what's your personal +position regarding government's action + + align:start position:0% +position regarding government's action + + + align:start position:0% +position regarding government's action +krina because you never mentioned + + align:start position:0% +krina because you never mentioned + + + align:start position:0% +krina because you never mentioned +anything while you were talking about it + + align:start position:0% +anything while you were talking about it + + + align:start position:0% +anything while you were talking about it +and I don't know the contrast between + + align:start position:0% +and I don't know the contrast between + + + align:start position:0% +and I don't know the contrast between +the photos + + align:start position:0% +the photos + + + align:start position:0% +the photos +well I I'd be interested I will answer + + align:start position:0% +well I I'd be interested I will answer + + + align:start position:0% +well I I'd be interested I will answer +that from the photographs what would you + + align:start position:0% +that from the photographs what would you + + + align:start position:0% +that from the photographs what would you +think my is there any hint in the + + align:start position:0% + + + + align:start position:0% + +images and there may not be you know the + + align:start position:0% +images and there may not be you know the + + + align:start position:0% +images and there may not be you know the +thing is you said that you were going to + + align:start position:0% +thing is you said that you were going to + + + align:start position:0% +thing is you said that you were going to +go there initially before the H right + + align:start position:0% +go there initially before the H right + + + align:start position:0% +go there initially before the H right +and to me it seems like you sort of + + align:start position:0% +and to me it seems like you sort of + + + align:start position:0% +and to me it seems like you sort of +photographed as if the H wouldn't have + + align:start position:0% +photographed as if the H wouldn't have + + + align:start position:0% +photographed as if the H wouldn't have +happened well to respect but like it + + align:start position:0% +happened well to respect but like it + + + align:start position:0% +happened well to respect but like it +still has that sort of quest that you + + align:start position:0% +still has that sort of quest that you + + + align:start position:0% +still has that sort of quest that you +have + + align:start position:0% +have + + + align:start position:0% +have +the way of looking that uh it continues + + align:start position:0% +the way of looking that uh it continues + + + align:start position:0% +the way of looking that uh it continues +regarding the geography as geography + + align:start position:0% +regarding the geography as geography + + + align:start position:0% +regarding the geography as geography +changes well it's interesting that I + + align:start position:0% +changes well it's interesting that I + + + align:start position:0% +changes well it's interesting that I +have + + align:start position:0% +have + + + align:start position:0% +have +shown a like + + align:start position:0% +shown a like + + + align:start position:0% +shown a like +150 image presentation of post Katrina + + align:start position:0% +150 image presentation of post Katrina + + + align:start position:0% +150 image presentation of post Katrina +work I think four or five times in the + + align:start position:0% +work I think four or five times in the + + + align:start position:0% +work I think four or five times in the +last couple of months and the last two + + align:start position:0% +last couple of months and the last two + + + align:start position:0% +last couple of months and the last two +times I showed it I was sick of it it + + align:start position:0% +times I showed it I was sick of it it + + + align:start position:0% +times I showed it I was sick of it it +was sort of like I it sort of like + + align:start position:0% +was sort of like I it sort of like + + + align:start position:0% +was sort of like I it sort of like +that's not I mean I obviously was drawn + + align:start position:0% +that's not I mean I obviously was drawn + + + align:start position:0% +that's not I mean I obviously was drawn +there I had to go there and I wanted to + + align:start position:0% +there I had to go there and I wanted to + + + align:start position:0% +there I had to go there and I wanted to +photograph it but I'm more interested in + + align:start position:0% +photograph it but I'm more interested in + + + align:start position:0% +photograph it but I'm more interested in +I mean one of the things that I missed I + + align:start position:0% +I mean one of the things that I missed I + + + align:start position:0% +I mean one of the things that I missed I +was there literally the first time after + + align:start position:0% +was there literally the first time after + + + align:start position:0% +was there literally the first time after +the hurricane when you could go there + + align:start position:0% +the hurricane when you could go there + + + align:start position:0% +the hurricane when you could go there +without having to show ID you know L + + align:start position:0% +without having to show ID you know L + + + align:start position:0% +without having to show ID you know L +that's I went made a beine and and the + + align:start position:0% +that's I went made a beine and and the + + + align:start position:0% +that's I went made a beine and and the +thing that happened almost everybody I + + align:start position:0% +thing that happened almost everybody I + + + align:start position:0% +thing that happened almost everybody I +knew was not there the streets were + + align:start position:0% +knew was not there the streets were + + + align:start position:0% +knew was not there the streets were +empty there's incredible Devastation + + align:start position:0% +empty there's incredible Devastation + + + align:start position:0% +empty there's incredible Devastation +which actually I haven't seen a + + align:start position:0% +which actually I haven't seen a + + + align:start position:0% +which actually I haven't seen a +photograph that really shows including + + align:start position:0% +photograph that really shows including + + + align:start position:0% +photograph that really shows including +my own I made a decision I've made a + + align:start position:0% +my own I made a decision I've made a + + + align:start position:0% +my own I made a decision I've made a +decision now and I think I'm going to + + align:start position:0% +decision now and I think I'm going to + + + align:start position:0% +decision now and I think I'm going to +revisit it cuz I haven't really printed + + align:start position:0% +revisit it cuz I haven't really printed + + + align:start position:0% +revisit it cuz I haven't really printed +it that that that's not the destruction + + align:start position:0% +it that that that's not the destruction + + + align:start position:0% +it that that that's not the destruction +pictures are of less interest to me and + + align:start position:0% +pictures are of less interest to me and + + + align:start position:0% +pictures are of less interest to me and +they don't even really speak to really + + align:start position:0% +they don't even really speak to really + + + align:start position:0% +they don't even really speak to really +what's going on they don't speak to the + + align:start position:0% +what's going on they don't speak to the + + + align:start position:0% +what's going on they don't speak to the +fact that people have been displaced + + align:start position:0% +fact that people have been displaced + + + align:start position:0% +fact that people have been displaced +they don't speak to the fact that the + + align:start position:0% +they don't speak to the fact that the + + + align:start position:0% +they don't speak to the fact that the +Lower Ninth Ward had something like 60 + + align:start position:0% +Lower Ninth Ward had something like 60 + + + align:start position:0% +Lower Ninth Ward had something like 60 +or 70% homeowners they don't I didn't + + align:start position:0% +or 70% homeowners they don't I didn't + + + align:start position:0% +or 70% homeowners they don't I didn't +show it there's an area called Lake View + + align:start position:0% +show it there's an area called Lake View + + + align:start position:0% +show it there's an area called Lake View +which was a middle class primarily white + + align:start position:0% +which was a middle class primarily white + + + align:start position:0% +which was a middle class primarily white +area that was right by the 7th Avenue + + align:start position:0% +area that was right by the 7th Avenue + + + align:start position:0% +area that was right by the 7th Avenue +Canal which had much it's a landfill it + + align:start position:0% +Canal which had much it's a landfill it + + + align:start position:0% +Canal which had much it's a landfill it +had houses that are probably 30 or 40 + + align:start position:0% +had houses that are probably 30 or 40 + + + align:start position:0% +had houses that are probably 30 or 40 +years old except for where the barge + + align:start position:0% +years old except for where the barge + + + align:start position:0% +years old except for where the barge +basically leveled house the housing + + align:start position:0% +basically leveled house the housing + + + align:start position:0% +basically leveled house the housing +damage was actually worse in Lake View + + align:start position:0% +damage was actually worse in Lake View + + + align:start position:0% +damage was actually worse in Lake View +because those houses weren't as well + + align:start position:0% +because those houses weren't as well + + + align:start position:0% +because those houses weren't as well +made as the earlier houses + + align:start position:0% +made as the earlier houses + + + align:start position:0% +made as the earlier houses +um uh but I'm more interested in like I + + align:start position:0% +um uh but I'm more interested in like I + + + align:start position:0% +um uh but I'm more interested in like I +live in Richmond and that was settled by + + align:start position:0% +live in Richmond and that was settled by + + + align:start position:0% +live in Richmond and that was settled by +a lot of people from Louisiana and + + align:start position:0% +a lot of people from Louisiana and + + + align:start position:0% +a lot of people from Louisiana and +there's not shotgun houses in Richmond + + align:start position:0% +there's not shotgun houses in Richmond + + + align:start position:0% +there's not shotgun houses in Richmond +but there the way people personalize + + align:start position:0% +but there the way people personalize + + + align:start position:0% +but there the way people personalize +their spaces with iron fences looks + + align:start position:0% +their spaces with iron fences looks + + + align:start position:0% +their spaces with iron fences looks +exactly like the ninth W it's really + + align:start position:0% +exactly like the ninth W it's really + + + align:start position:0% +exactly like the ninth W it's really +amazing so that you know I guess for + + align:start position:0% +amazing so that you know I guess for + + + align:start position:0% +amazing so that you know I guess for +this talk I was more interested in the + + align:start position:0% +this talk I was more interested in the + + + align:start position:0% +this talk I was more interested in the +whole idea of transference um and at + + align:start position:0% +whole idea of transference um and at + + + align:start position:0% +whole idea of transference um and at +least for here less I'm less interested + + align:start position:0% +least for here less I'm less interested + + + align:start position:0% +least for here less I'm less interested +in the effects of the hurricane the + + align:start position:0% +in the effects of the hurricane the + + + align:start position:0% +in the effects of the hurricane the +physical effects of the hurricane I am + + align:start position:0% +physical effects of the hurricane I am + + + align:start position:0% +physical effects of the hurricane I am +very interested in the social I'm also + + align:start position:0% +very interested in the social I'm also + + + align:start position:0% +very interested in the social I'm also +interested in terms of when I talk to + + align:start position:0% +interested in terms of when I talk to + + + align:start position:0% +interested in terms of when I talk to +people you know there were all these + + align:start position:0% +people you know there were all these + + + align:start position:0% +people you know there were all these +stories well there were stories that + + align:start position:0% +stories well there were stories that + + + align:start position:0% +stories well there were stories that +there were gangs of black people killing + + align:start position:0% +there were gangs of black people killing + + + align:start position:0% +there were gangs of black people killing +people in the Garden District which + + align:start position:0% +people in the Garden District which + + + align:start position:0% +people in the Garden District which +wasn't true there were stories that + + align:start position:0% +wasn't true there were stories that + + + align:start position:0% +wasn't true there were stories that +multiple people were raped in the + + align:start position:0% +multiple people were raped in the + + + align:start position:0% +multiple people were raped in the +Astrodome which which was also not true + + align:start position:0% +Astrodome which which was also not true + + + align:start position:0% +Astrodome which which was also not true +people were smoking Kraken it was + + align:start position:0% +people were smoking Kraken it was + + + align:start position:0% +people were smoking Kraken it was +horrendous but it was interesting that + + align:start position:0% +horrendous but it was interesting that + + + align:start position:0% +horrendous but it was interesting that +the hurricane well what it did reflect + + align:start position:0% +the hurricane well what it did reflect + + + align:start position:0% +the hurricane well what it did reflect +is the the I Love New Orleans but I also + + align:start position:0% +is the the I Love New Orleans but I also + + + align:start position:0% +is the the I Love New Orleans but I also +hate it because the racism the racism is + + align:start position:0% +hate it because the racism the racism is + + + align:start position:0% +hate it because the racism the racism is +almost breathtaking it's so palpable and + + align:start position:0% +almost breathtaking it's so palpable and + + + align:start position:0% +almost breathtaking it's so palpable and +that's one of the things I don't like + + align:start position:0% +that's one of the things I don't like + + + align:start position:0% +that's one of the things I don't like +about the south and I I don't want to + + align:start position:0% +about the south and I I don't want to + + + align:start position:0% +about the south and I I don't want to +you know um + + align:start position:0% +you know um + + + align:start position:0% +you know um +uh there's some things fauler said in + + align:start position:0% +uh there's some things fauler said in + + + align:start position:0% +uh there's some things fauler said in +the South the past isn't really the past + + align:start position:0% +the South the past isn't really the past + + + align:start position:0% +the South the past isn't really the past +in history is right just below the C and + + align:start position:0% +in history is right just below the C and + + + align:start position:0% +in history is right just below the C and +that's absolutely the truth and that's + + align:start position:0% +that's absolutely the truth and that's + + + align:start position:0% +that's absolutely the truth and that's +those are things I'm really interested + + align:start position:0% +those are things I'm really interested + + + align:start position:0% +those are things I'm really interested +in photographing but there's also + + align:start position:0% +in photographing but there's also + + + align:start position:0% +in photographing but there's also +elements about that I am disgusted by + + align:start position:0% +elements about that I am disgusted by + + + align:start position:0% +elements about that I am disgusted by +and can't be around for long periods of + + align:start position:0% +and can't be around for long periods of + + + align:start position:0% +and can't be around for long periods of +time so but I did really was very upset + + align:start position:0% +time so but I did really was very upset + + + align:start position:0% +time so but I did really was very upset +to not have a chance to be in New + + align:start position:0% +to not have a chance to be in New + + + align:start position:0% +to not have a chance to be in New +Orleans I was going to be at the AY + + align:start position:0% +Orleans I was going to be at the AY + + + align:start position:0% +Orleans I was going to be at the AY +Museum of Southern art because there New + + align:start position:0% +Museum of Southern art because there New + + + align:start position:0% +Museum of Southern art because there New +Orleans is an incredible Art Center + + align:start position:0% +Orleans is an incredible Art Center + + + align:start position:0% +Orleans is an incredible Art Center +there's I sort of said New Orleans is a + + align:start position:0% +there's I sort of said New Orleans is a + + + align:start position:0% +there's I sort of said New Orleans is a +place where there's not much mediocrity + + align:start position:0% +place where there's not much mediocrity + + + align:start position:0% +place where there's not much mediocrity +there's incredible genius and incredible + + align:start position:0% +there's incredible genius and incredible + + + align:start position:0% +there's incredible genius and incredible +Inc competence and there's there um + + align:start position:0% +Inc competence and there's there um + + + align:start position:0% +Inc competence and there's there um +artists incredible artists artists that + + align:start position:0% +artists incredible artists artists that + + + align:start position:0% +artists incredible artists artists that +we don't even know visual artists + + align:start position:0% +we don't even know visual artists + + + align:start position:0% +we don't even know visual artists +musicians uh acting and I I in the + + align:start position:0% +musicians uh acting and I I in the + + + align:start position:0% +musicians uh acting and I I in the +course of visiting have gotten a chance + + align:start position:0% +course of visiting have gotten a chance + + + align:start position:0% +course of visiting have gotten a chance +to meet some of them but and this would + + align:start position:0% +to meet some of them but and this would + + + align:start position:0% +to meet some of them but and this would +have been a chance to sort of get you + + align:start position:0% +have been a chance to sort of get you + + + align:start position:0% +have been a chance to sort of get you +know further below the beneath the + + align:start position:0% +know further below the beneath the + + + align:start position:0% +know further below the beneath the +surface and I guess at this point + + align:start position:0% +surface and I guess at this point + + + align:start position:0% +surface and I guess at this point +because I've been dealing with the + + align:start position:0% +because I've been dealing with the + + + align:start position:0% +because I've been dealing with the +destruction I'm much more interested in + + align:start position:0% +destruction I'm much more interested in + + + align:start position:0% +destruction I'm much more interested in +kind of what New Orleans was and what it + + align:start position:0% +kind of what New Orleans was and what it + + + align:start position:0% +kind of what New Orleans was and what it +will be I I'm going to go in May and + + align:start position:0% +will be I I'm going to go in May and + + + align:start position:0% +will be I I'm going to go in May and +kind of uh work with a colleague of mine + + align:start position:0% +kind of uh work with a colleague of mine + + + align:start position:0% +kind of uh work with a colleague of mine +um we're going to kind of examine how + + align:start position:0% +um we're going to kind of examine how + + + align:start position:0% +um we're going to kind of examine how +something like the Jazz Fest and the + + align:start position:0% +something like the Jazz Fest and the + + + align:start position:0% +something like the Jazz Fest and the +role of culture whether that will be + + align:start position:0% +role of culture whether that will be + + + align:start position:0% +role of culture whether that will be +used to make New Orleans into a boutique + + align:start position:0% +used to make New Orleans into a boutique + + + align:start position:0% +used to make New Orleans into a boutique +or a theme park or to sort of bring back + + align:start position:0% +or a theme park or to sort of bring back + + + align:start position:0% +or a theme park or to sort of bring back +what was before and as someone told me + + align:start position:0% +what was before and as someone told me + + + align:start position:0% +what was before and as someone told me +it's probably going to be a combination + + align:start position:0% +it's probably going to be a combination + + + align:start position:0% +it's probably going to be a combination +of + + align:start position:0% + + + + align:start position:0% + +both all right thank you + + align:start position:0% +both all right thank you + + + align:start position:0% +both all right thank you +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] \ No newline at end of file diff --git a/GZQ-8pg7bgk.txt b/GZQ-8pg7bgk.txt new file mode 100644 index 0000000000000000000000000000000000000000..b071ad44719c7a41097b20189f1b3fb2f89099ce --- /dev/null +++ b/GZQ-8pg7bgk.txt @@ -0,0 +1,12603 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +we talked about + + align:start position:0% +we talked about + + + align:start position:0% +we talked about +path integral + + align:start position:0% +path integral + + + align:start position:0% +path integral +formulation of quantum mechanics + + align:start position:0% +formulation of quantum mechanics + + + align:start position:0% +formulation of quantum mechanics +so let me just quickly remind you the + + align:start position:0% +so let me just quickly remind you the + + + align:start position:0% +so let me just quickly remind you the +main idea + + align:start position:0% + + + + align:start position:0% + +Okay so classically + + align:start position:0% + + + + align:start position:0% + +if we specify the initial location + + align:start position:0% +if we specify the initial location + + + align:start position:0% +if we specify the initial location +say if you add T Prime X Prime + + align:start position:0% +say if you add T Prime X Prime + + + align:start position:0% +say if you add T Prime X Prime +and then the final location + + align:start position:0% + + + + align:start position:0% + +T and X + + align:start position:0% +T and X + + + align:start position:0% +T and X +said time T you add X and then there's a + + align:start position:0% +said time T you add X and then there's a + + + align:start position:0% +said time T you add X and then there's a +unique trajectory okay + + align:start position:0% +unique trajectory okay + + + align:start position:0% +unique trajectory okay +and it's a unique detection + + align:start position:0% +and it's a unique detection + + + align:start position:0% +and it's a unique detection +so Quantum mechanically + + align:start position:0% + + + + align:start position:0% + +you ask a different question + + align:start position:0% +you ask a different question + + + align:start position:0% +you ask a different question +you ask what is the transition amplitude + + align:start position:0% + + + + align:start position:0% + +if you say at T Prime + + align:start position:0% +if you say at T Prime + + + align:start position:0% +if you say at T Prime +you add location X Prime and what's the + + align:start position:0% +you add location X Prime and what's the + + + align:start position:0% +you add location X Prime and what's the +transition amplitude at time T you add + + align:start position:0% +transition amplitude at time T you add + + + align:start position:0% +transition amplitude at time T you add +location X + + align:start position:0% +location X + + + align:start position:0% +location X +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and the answer for this question + + align:start position:0% + + + + align:start position:0% + +now is equal to + + align:start position:0% +now is equal to + + + align:start position:0% +now is equal to +you just sum + + align:start position:0% +you just sum + + + align:start position:0% +you just sum +of all possible path + + align:start position:0% +of all possible path + + + align:start position:0% +of all possible path +between + + align:start position:0% +between + + + align:start position:0% +between +T Prime and X Prime and the TX okay + + align:start position:0% +T Prime and X Prime and the TX okay + + + align:start position:0% +T Prime and X Prime and the TX okay +so it's just sum of all possible paths + + align:start position:0% +so it's just sum of all possible paths + + + align:start position:0% +so it's just sum of all possible paths +and with some weight okay + + align:start position:0% +and with some weight okay + + + align:start position:0% +and with some weight okay +so more explicitly + + align:start position:0% + + + + align:start position:0% + +and with the weight you sum of all paths + + align:start position:0% +and with the weight you sum of all paths + + + align:start position:0% +and with the weight you sum of all paths +and the weight is given by experiential + + align:start position:0% +and the weight is given by experiential + + + align:start position:0% +and the weight is given by experiential +i h + + align:start position:0% +i h + + + align:start position:0% +i h +s + + align:start position:0% + + + + align:start position:0% + +so for each pass you have action + + align:start position:0% +so for each pass you have action + + + align:start position:0% +so for each pass you have action +and then just evaluate for each part the + + align:start position:0% +and then just evaluate for each part the + + + align:start position:0% +and then just evaluate for each part the +action and then yeah here also + + align:start position:0% +action and then yeah here also + + + align:start position:0% +action and then yeah here also +we explicit H bar here and because the + + align:start position:0% +we explicit H bar here and because the + + + align:start position:0% +we explicit H bar here and because the +action has the unit of H bar and yeah so + + align:start position:0% +action has the unit of H bar and yeah so + + + align:start position:0% +action has the unit of H bar and yeah so +this would be the + + align:start position:0% +this would be the + + + align:start position:0% +this would be the +um + + align:start position:0% +um + + + align:start position:0% +um +the quantum mechanical answer okay so + + align:start position:0% +the quantum mechanical answer okay so + + + align:start position:0% +the quantum mechanical answer okay so +this is a formulation of quantum + + align:start position:0% +this is a formulation of quantum + + + align:start position:0% +this is a formulation of quantum +mechanics + + align:start position:0% +mechanics + + + align:start position:0% +mechanics +even in path integral + + align:start position:0% +even in path integral + + + align:start position:0% +even in path integral +and so we can write this more explicitly + + align:start position:0% + + + + align:start position:0% + +mathematically mathematical rotation + + align:start position:0% +mathematically mathematical rotation + + + align:start position:0% +mathematically mathematical rotation +for disarming over Parts is the + + align:start position:0% +for disarming over Parts is the + + + align:start position:0% +for disarming over Parts is the +following + + align:start position:0% +following + + + align:start position:0% +following +say we + + align:start position:0% +say we + + + align:start position:0% +say we +introduce a rotation like this which you + + align:start position:0% +introduce a rotation like this which you + + + align:start position:0% +introduce a rotation like this which you +integrate over all possible trajectories + + align:start position:0% +integrate over all possible trajectories + + + align:start position:0% +integrate over all possible trajectories +between x t Prime equal to X + + align:start position:0% +between x t Prime equal to X + + + align:start position:0% +between x t Prime equal to X +and x t or X Prime and x t equal to X + + align:start position:0% +and x t or X Prime and x t equal to X + + + align:start position:0% +and x t or X Prime and x t equal to X +and then + + align:start position:0% +and then + + + align:start position:0% +and then +you integrate under the U with weight + + align:start position:0% +you integrate under the U with weight + + + align:start position:0% +you integrate under the U with weight +as + + align:start position:0% +as + + + align:start position:0% +as +x t + + align:start position:0% +x t + + + align:start position:0% +x t +and the x t + + align:start position:0% + + + + align:start position:0% + +and x t is a function of x t + + align:start position:0% +and x t is a function of x t + + + align:start position:0% +and x t is a function of x t +which give you + + align:start position:0% +which give you + + + align:start position:0% +which give you +which you increase integrate from T + + align:start position:0% +which you increase integrate from T + + + align:start position:0% +which you increase integrate from T +Prime to T + + align:start position:0% +Prime to T + + + align:start position:0% +Prime to T +we have t + + align:start position:0% +we have t + + + align:start position:0% +we have t +double Prime + + align:start position:0% +double Prime + + + align:start position:0% +double Prime +so one half m x dot Square minus BX okay + + align:start position:0% +so one half m x dot Square minus BX okay + + + align:start position:0% +so one half m x dot Square minus BX okay +so this is for the one dimensional + + align:start position:0% +so this is for the one dimensional + + + align:start position:0% +so this is for the one dimensional +particle + + align:start position:0% + + + + align:start position:0% + +and also this + + align:start position:0% +and also this + + + align:start position:0% +and also this +so all the trajectory with this fixed + + align:start position:0% +so all the trajectory with this fixed + + + align:start position:0% +so all the trajectory with this fixed +endpoint and T Prime should be equal to + + align:start position:0% +endpoint and T Prime should be equal to + + + align:start position:0% +endpoint and T Prime should be equal to +X Prime and the time T could be equal to + + align:start position:0% +X Prime and the time T could be equal to + + + align:start position:0% +X Prime and the time T could be equal to +X + + align:start position:0% +X + + + align:start position:0% +X +and also this integration is a shorthand + + align:start position:0% +and also this integration is a shorthand + + + align:start position:0% +and also this integration is a shorthand +notation + + align:start position:0% +notation + + + align:start position:0% +notation +for limit + + align:start position:0% +for limit + + + align:start position:0% +for limit +so this DX t + + align:start position:0% +so this DX t + + + align:start position:0% +so this DX t +should be understood as a limit + + align:start position:0% + + + + align:start position:0% + +when you take angles Infinity + + align:start position:0% +when you take angles Infinity + + + align:start position:0% +when you take angles Infinity +this factor of + + align:start position:0% +this factor of + + + align:start position:0% +this factor of +n divided by 2 pi I + + align:start position:0% +n divided by 2 pi I + + + align:start position:0% +n divided by 2 pi I +delta T So essentially you divide your + + align:start position:0% +delta T So essentially you divide your + + + align:start position:0% +delta T So essentially you divide your +path + + align:start position:0% +path + + + align:start position:0% +path +by by intervals of delta T + + align:start position:0% +by by intervals of delta T + + + align:start position:0% +by by intervals of delta T +and then you integrate over all possible + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +yeah okay so so you separate the path + + align:start position:0% +yeah okay so so you separate the path + + + align:start position:0% +yeah okay so so you separate the path +from t t Prime to T + + align:start position:0% +from t t Prime to T + + + align:start position:0% +from t t Prime to T +by by n segment + + align:start position:0% +by by n segment + + + align:start position:0% +by by n segment +so this is the t i + + align:start position:0% +so this is the t i + + + align:start position:0% +so this is the t i +and then location will be x i + + align:start position:0% + + + + align:start position:0% + +so this is TI and location and then you + + align:start position:0% +so this is TI and location and then you + + + align:start position:0% +so this is TI and location and then you +integrate the x i of that okay + + align:start position:0% +integrate the x i of that okay + + + align:start position:0% +integrate the x i of that okay +so so this is the + + align:start position:0% +so so this is the + + + align:start position:0% +so so this is the +um formulation of fast integral + + align:start position:0% +um formulation of fast integral + + + align:start position:0% +um formulation of fast integral +for quantum mechanics + + align:start position:0% +for quantum mechanics + + + align:start position:0% +for quantum mechanics +any questions on this + + align:start position:0% +any questions on this + + + align:start position:0% +any questions on this +yes + + align:start position:0% + + + + align:start position:0% + +uh yeah yeah in principle you can also + + align:start position:0% +uh yeah yeah in principle you can also + + + align:start position:0% +uh yeah yeah in principle you can also +do this in momentum basis yeah momentum + + align:start position:0% +do this in momentum basis yeah momentum + + + align:start position:0% +do this in momentum basis yeah momentum +space and and also you can actually also + + align:start position:0% +space and and also you can actually also + + + align:start position:0% +space and and also you can actually also +generalize + + align:start position:0% +generalize + + + align:start position:0% +generalize +so + + align:start position:0% +so + + + align:start position:0% +so +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +um + + align:start position:0% +um + + + align:start position:0% +um +yeah but + + align:start position:0% +yeah but + + + align:start position:0% +yeah but +yeah we will talk about the how you + + align:start position:0% +yeah we will talk about the how you + + + align:start position:0% +yeah we will talk about the how you +generalize this uh to to other bases and + + align:start position:0% +generalize this uh to to other bases and + + + align:start position:0% +generalize this uh to to other bases and +uh but but this is the fundamental + + align:start position:0% +uh but but this is the fundamental + + + align:start position:0% +uh but but this is the fundamental +formulation and uh when you write it in + + align:start position:0% +formulation and uh when you write it in + + + align:start position:0% +formulation and uh when you write it in +other bases you essentially you reduce + + align:start position:0% +other bases you essentially you reduce + + + align:start position:0% +other bases you essentially you reduce +to this basis and because this is the + + align:start position:0% +to this basis and because this is the + + + align:start position:0% +to this basis and because this is the +most intuitive way yeah + + align:start position:0% +most intuitive way yeah + + + align:start position:0% +most intuitive way yeah +to to uh to formulate it + + align:start position:0% +to to uh to formulate it + + + align:start position:0% +to to uh to formulate it +any other questions + + align:start position:0% + + + + align:start position:0% + +okay create + + align:start position:0% +okay create + + + align:start position:0% +okay create +so a simple example + + align:start position:0% +so a simple example + + + align:start position:0% +so a simple example +is just a free particle + + align:start position:0% + + + + align:start position:0% + +when you have a free particle + + align:start position:0% + + + + align:start position:0% + +let me just then then the S is + + align:start position:0% +let me just then then the S is + + + align:start position:0% +let me just then then the S is +particularly simple you just the + + align:start position:0% +particularly simple you just the + + + align:start position:0% +particularly simple you just the +integration + + align:start position:0% +integration + + + align:start position:0% +integration +of one half MX Square + + align:start position:0% +of one half MX Square + + + align:start position:0% +of one half MX Square +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so we described + + align:start position:0% +so we described + + + align:start position:0% +so we described +edible s is equal to this + + align:start position:0% +edible s is equal to this + + + align:start position:0% +edible s is equal to this +and then this is like a gaussian + + align:start position:0% +and then this is like a gaussian + + + align:start position:0% +and then this is like a gaussian +integral + + align:start position:0% +integral + + + align:start position:0% +integral +okay because this is quadratic in x + + align:start position:0% +okay because this is quadratic in x + + + align:start position:0% +okay because this is quadratic in x +okay so this is like a gaussian integral + + align:start position:0% +okay so this is like a gaussian integral + + + align:start position:0% +okay so this is like a gaussian integral +and so you can reduce so so in this case + + align:start position:0% +and so you can reduce so so in this case + + + align:start position:0% +and so you can reduce so so in this case +you have a gaussian integral + + align:start position:0% + + + + align:start position:0% + +and schematically + + align:start position:0% +and schematically + + + align:start position:0% +and schematically +you have something like this + + align:start position:0% + + + + align:start position:0% + +you can + + align:start position:0% +you can + + + align:start position:0% +you can +so + + align:start position:0% + + + + align:start position:0% + +when axis of this form you can write it + + align:start position:0% +when axis of this form you can write it + + + align:start position:0% +when axis of this form you can write it +in this general form + + align:start position:0% +in this general form + + + align:start position:0% +in this general form +you can write the path integral in this + + align:start position:0% +you can write the path integral in this + + + align:start position:0% +you can write the path integral in this +general form and the K in this case will + + align:start position:0% +general form and the K in this case will + + + align:start position:0% +general form and the K in this case will +be some Delta function yeah I wrote down + + align:start position:0% +be some Delta function yeah I wrote down + + + align:start position:0% +be some Delta function yeah I wrote down +K last time explicitly + + align:start position:0% +K last time explicitly + + + align:start position:0% +K last time explicitly +and then this is like a golfing integral + + align:start position:0% + + + + align:start position:0% + +and in the Gauss integral we can just + + align:start position:0% +and in the Gauss integral we can just + + + align:start position:0% +and in the Gauss integral we can just +directly + + align:start position:0% +directly + + + align:start position:0% +directly +write down its answer + + align:start position:0% +write down its answer + + + align:start position:0% +write down its answer +and some constant divided by Delta k + + align:start position:0% +and some constant divided by Delta k + + + align:start position:0% +and some constant divided by Delta k +so this determinant is defined in the + + align:start position:0% +so this determinant is defined in the + + + align:start position:0% +so this determinant is defined in the +space of functions okay so and C is some + + align:start position:0% +space of functions okay so and C is some + + + align:start position:0% +space of functions okay so and C is some +constant + + align:start position:0% +constant + + + align:start position:0% +constant +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so you may also view this just as + + align:start position:0% +so you may also view this just as + + + align:start position:0% +so you may also view this just as +a + + align:start position:0% +a + + + align:start position:0% +a +lateral yeah so this also just follows + + align:start position:0% +lateral yeah so this also just follows + + + align:start position:0% +lateral yeah so this also just follows +from this continuous okay follow from + + align:start position:0% +from this continuous okay follow from + + + align:start position:0% +from this continuous okay follow from +this discrete case which you take a + + align:start position:0% +this discrete case which you take a + + + align:start position:0% +this discrete case which you take a +Continuum limit + + align:start position:0% +Continuum limit + + + align:start position:0% +Continuum limit +yes + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +yeah yeah this is the same as you do the + + align:start position:0% +yeah yeah this is the same as you do the + + + align:start position:0% +yeah yeah this is the same as you do the +standard gaussian integral with the I + + align:start position:0% +standard gaussian integral with the I + + + align:start position:0% +standard gaussian integral with the I +yeah that integral you can also do + + align:start position:0% + + + + align:start position:0% + +you know it's a it's a + + align:start position:0% +you know it's a it's a + + + align:start position:0% +you know it's a it's a +yeah just with a single + + align:start position:0% + + + + align:start position:0% + +so this integral + + align:start position:0% +so this integral + + + align:start position:0% +so this integral +we can Define right + + align:start position:0% +we can Define right + + + align:start position:0% +we can Define right +yeah this integral is we know how to do + + align:start position:0% +yeah this integral is we know how to do + + + align:start position:0% +yeah this integral is we know how to do +this integral it's the same as this one + + align:start position:0% +this integral it's the same as this one + + + align:start position:0% +this integral it's the same as this one +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +so yeah + + align:start position:0% +so yeah + + + align:start position:0% +so yeah +so you have to + + align:start position:0% +so you have to + + + align:start position:0% +so you have to +do a really mathematical trick to do + + align:start position:0% +do a really mathematical trick to do + + + align:start position:0% +do a really mathematical trick to do +this integral and but but this integral + + align:start position:0% +this integral and but but this integral + + + align:start position:0% +this integral and but but this integral +is defined yeah we can give a value + + align:start position:0% + + + + align:start position:0% + +other questions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +good so so so this uh is the + + align:start position:0% +good so so so this uh is the + + + align:start position:0% +good so so so this uh is the +path integral + + align:start position:0% +path integral + + + align:start position:0% +path integral +for for quantum mechanics with one + + align:start position:0% +for for quantum mechanics with one + + + align:start position:0% +for for quantum mechanics with one +degree of freedom + + align:start position:0% +degree of freedom + + + align:start position:0% +degree of freedom +so now we can just immediately + + align:start position:0% +so now we can just immediately + + + align:start position:0% +so now we can just immediately +generalize these two more the good + + align:start position:0% +generalize these two more the good + + + align:start position:0% +generalize these two more the good +freedom + + align:start position:0% +freedom + + + align:start position:0% +freedom +okay and there's nothing really change + + align:start position:0% +okay and there's nothing really change + + + align:start position:0% +okay and there's nothing really change +when you have more than one degree + + align:start position:0% +when you have more than one degree + + + align:start position:0% +when you have more than one degree +Freedom just integrate over so if you + + align:start position:0% +Freedom just integrate over so if you + + + align:start position:0% +Freedom just integrate over so if you +have say + + align:start position:0% +have say + + + align:start position:0% +have say +three particles then you just integrate + + align:start position:0% +three particles then you just integrate + + + align:start position:0% +three particles then you just integrate +the dx1 dx2 dx3 and then use the same + + align:start position:0% +the dx1 dx2 dx3 and then use the same + + + align:start position:0% +the dx1 dx2 dx3 and then use the same +action okay + + align:start position:0% +action okay + + + align:start position:0% +action okay +so you just uh uh straightforward + + align:start position:0% +so you just uh uh straightforward + + + align:start position:0% +so you just uh uh straightforward +generalize + + align:start position:0% +generalize + + + align:start position:0% +generalize +and then we can generalize to field + + align:start position:0% +and then we can generalize to field + + + align:start position:0% +and then we can generalize to field +Theory because Fields here we just take + + align:start position:0% +Theory because Fields here we just take + + + align:start position:0% +Theory because Fields here we just take +an alarm with equals freedom to Infinity + + align:start position:0% +an alarm with equals freedom to Infinity + + + align:start position:0% +an alarm with equals freedom to Infinity +okay so so we can now + + align:start position:0% + + + + align:start position:0% + +so to field Theory + + align:start position:0% + + + + align:start position:0% + +so in this case from the uh + + align:start position:0% +so in this case from the uh + + + align:start position:0% +so in this case from the uh +we just need to replace + + align:start position:0% +we just need to replace + + + align:start position:0% +we just need to replace +in the different places by so remember + + align:start position:0% +in the different places by so remember + + + align:start position:0% +in the different places by so remember +so the dynamical variable for single + + align:start position:0% +so the dynamical variable for single + + + align:start position:0% +so the dynamical variable for single +particle + + align:start position:0% +particle + + + align:start position:0% +particle +you have this operator + + align:start position:0% +you have this operator + + + align:start position:0% +you have this operator +and then when you go to field Theory + + align:start position:0% +and then when you go to field Theory + + + align:start position:0% +and then when you go to field Theory +the counterpart of this + + align:start position:0% +the counterpart of this + + + align:start position:0% +the counterpart of this +is the Phi + + align:start position:0% + + + + align:start position:0% + +okay is the + + align:start position:0% +okay is the + + + align:start position:0% +okay is the +is the Phi is the field variable + + align:start position:0% +is the Phi is the field variable + + + align:start position:0% +is the Phi is the field variable +and then + + align:start position:0% +and then + + + align:start position:0% +and then +so this quantity + + align:start position:0% + + + + align:start position:0% + +when you go to field Theory + + align:start position:0% +when you go to field Theory + + + align:start position:0% +when you go to field Theory +the corresponding quantity + + align:start position:0% +the corresponding quantity + + + align:start position:0% +the corresponding quantity +is + + align:start position:0% +is + + + align:start position:0% +is +5X + + align:start position:0% +5X + + + align:start position:0% +5X +smt + + align:start position:0% +smt + + + align:start position:0% +smt +and the Phi X say Phi Prime X + + align:start position:0% + + + + align:start position:0% + +and time T Prime + + align:start position:0% +and time T Prime + + + align:start position:0% +and time T Prime +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% + + + + align:start position:0% + +again the way to think about this is + + align:start position:0% +again the way to think about this is + + + align:start position:0% +again the way to think about this is +just you should view this X as label + + align:start position:0% +just you should view this X as label + + + align:start position:0% +just you should view this X as label +and then this is just like I see we have + + align:start position:0% +and then this is just like I see we have + + + align:start position:0% +and then this is just like I see we have +infinite number of of positions okay I + + align:start position:0% +infinite number of of positions okay I + + + align:start position:0% +infinite number of of positions okay I +just have infinite number five which are + + align:start position:0% +just have infinite number five which are + + + align:start position:0% +just have infinite number five which are +eigenvalues of this operator at time T + + align:start position:0% +eigenvalues of this operator at time T + + + align:start position:0% +eigenvalues of this operator at time T +at T Prime and similarly here okay + + align:start position:0% +at T Prime and similarly here okay + + + align:start position:0% +at T Prime and similarly here okay +and the um + + align:start position:0% +and the um + + + align:start position:0% +and the um +so so again he this one you can write it + + align:start position:0% +so so again he this one you can write it + + + align:start position:0% +so so again he this one you can write it +in the form + + align:start position:0% +in the form + + + align:start position:0% +in the form +in terms of the position eigen state so + + align:start position:0% +in terms of the position eigen state so + + + align:start position:0% +in terms of the position eigen state so +this is the position I can stay in field + + align:start position:0% +this is the position I can stay in field + + + align:start position:0% +this is the position I can stay in field +Theory + + align:start position:0% + + + + align:start position:0% + +okay so this is the position I can say + + align:start position:0% +okay so this is the position I can say + + + align:start position:0% +okay so this is the position I can say +in field Theory and then we can use the + + align:start position:0% +in field Theory and then we can use the + + + align:start position:0% +in field Theory and then we can use the +same Technique we discussed last time + + align:start position:0% +same Technique we discussed last time + + + align:start position:0% +same Technique we discussed last time +you just split this into many many + + align:start position:0% +you just split this into many many + + + align:start position:0% +you just split this into many many +infinitesimal pieces by split in the + + align:start position:0% +infinitesimal pieces by split in the + + + align:start position:0% +infinitesimal pieces by split in the +time interval from T Prime to T + + align:start position:0% +time interval from T Prime to T + + + align:start position:0% +time interval from T Prime to T +and split into many pieces and then just + + align:start position:0% +and split into many pieces and then just + + + align:start position:0% +and split into many pieces and then just +do it over and over and insert the + + align:start position:0% +do it over and over and insert the + + + align:start position:0% +do it over and over and insert the +complete side of state of Phi + + align:start position:0% +complete side of state of Phi + + + align:start position:0% +complete side of state of Phi +okay + + align:start position:0% + + + + align:start position:0% + +and then I just uh so h + + align:start position:0% +and then I just uh so h + + + align:start position:0% +and then I just uh so h +is now + + align:start position:0% +is now + + + align:start position:0% +is now +of course it's the field counterpart of + + align:start position:0% +of course it's the field counterpart of + + + align:start position:0% +of course it's the field counterpart of +it + + align:start position:0% +it + + + align:start position:0% +it +just H equal to but the details of this + + align:start position:0% +just H equal to but the details of this + + + align:start position:0% +just H equal to but the details of this +does not matter + + align:start position:0% + + + + align:start position:0% + +say say this is the hamiltonian you can + + align:start position:0% +say say this is the hamiltonian you can + + + align:start position:0% +say say this is the hamiltonian you can +just insert this into here and then you + + align:start position:0% +just insert this into here and then you + + + align:start position:0% +just insert this into here and then you +just repeat the same procedure okay just + + align:start position:0% +just repeat the same procedure okay just + + + align:start position:0% +just repeat the same procedure okay just +keep in mind + + align:start position:0% +keep in mind + + + align:start position:0% +keep in mind +now you just have infinite number of + + align:start position:0% +now you just have infinite number of + + + align:start position:0% +now you just have infinite number of +this freedom + + align:start position:0% +this freedom + + + align:start position:0% +this freedom +okay that's the only difference we just + + align:start position:0% +okay that's the only difference we just + + + align:start position:0% +okay that's the only difference we just +your rotation become a little bit more + + align:start position:0% +your rotation become a little bit more + + + align:start position:0% +your rotation become a little bit more +complicated + + align:start position:0% +complicated + + + align:start position:0% +complicated +but if you keep a very clear mind + + align:start position:0% +but if you keep a very clear mind + + + align:start position:0% +but if you keep a very clear mind +with the correspondence with a single + + align:start position:0% +with the correspondence with a single + + + align:start position:0% +with the correspondence with a single +particle case + + align:start position:0% +particle case + + + align:start position:0% +particle case +okay then everything is the same okay + + align:start position:0% +okay then everything is the same okay + + + align:start position:0% +okay then everything is the same okay +just if you understand how to translate + + align:start position:0% +just if you understand how to translate + + + align:start position:0% +just if you understand how to translate +the notation here to the rotation here + + align:start position:0% +the notation here to the rotation here + + + align:start position:0% +the notation here to the rotation here +then everything is just exactly the same + + align:start position:0% +then everything is just exactly the same + + + align:start position:0% +then everything is just exactly the same +okay just everything goes through so I + + align:start position:0% +okay just everything goes through so I + + + align:start position:0% +okay just everything goes through so I +will not repeat that procedure + + align:start position:0% +will not repeat that procedure + + + align:start position:0% +will not repeat that procedure +and now you just find this quantity okay + + align:start position:0% +and now you just find this quantity okay + + + align:start position:0% +and now you just find this quantity okay +then again we can write this in terms of + + align:start position:0% +then again we can write this in terms of + + + align:start position:0% +then again we can write this in terms of +path integral + + align:start position:0% +path integral + + + align:start position:0% +path integral +so now this can be written as + + align:start position:0% +so now this can be written as + + + align:start position:0% +so now this can be written as +you can pass integral Phi now you + + align:start position:0% +you can pass integral Phi now you + + + align:start position:0% +you can pass integral Phi now you +integrate over all possible + + align:start position:0% +integrate over all possible + + + align:start position:0% +integrate over all possible +configuration of Phi + + align:start position:0% + + + + align:start position:0% + +which is the boundary condition + + align:start position:0% +which is the boundary condition + + + align:start position:0% +which is the boundary condition +Phi T Prime x equal to 5 Prime X + + align:start position:0% +Phi T Prime x equal to 5 Prime X + + + align:start position:0% +Phi T Prime x equal to 5 Prime X +and Phi TX + + align:start position:0% +and Phi TX + + + align:start position:0% +and Phi TX +equal to 5X + + align:start position:0% +equal to 5X + + + align:start position:0% +equal to 5X +and again you just have exponential + + align:start position:0% +and again you just have exponential + + + align:start position:0% +and again you just have exponential +is 5. + + align:start position:0% +is 5. + + + align:start position:0% +is 5. +and S is its action for Phi + + align:start position:0% +and S is its action for Phi + + + align:start position:0% +and S is its action for Phi +so now the s + + align:start position:0% + + + + align:start position:0% + +is now + + align:start position:0% + + + + align:start position:0% + +so in this case yeah this is the + + align:start position:0% +so in this case yeah this is the + + + align:start position:0% +so in this case yeah this is the +integration of the language density and + + align:start position:0% +integration of the language density and + + + align:start position:0% +integration of the language density and +L is + + align:start position:0% +L is + + + align:start position:0% +L is +one half + + align:start position:0% +one half + + + align:start position:0% +one half +yeah it just what we wrote down before + + align:start position:0% + + + + align:start position:0% + +okay some potential Phi okay + + align:start position:0% + + + + align:start position:0% + +so so for any scalar field still these + + align:start position:0% +so so for any scalar field still these + + + align:start position:0% +so so for any scalar field still these +just work identically + + align:start position:0% +just work identically + + + align:start position:0% +just work identically +okay and again you just get the + + align:start position:0% +okay and again you just get the + + + align:start position:0% +okay and again you just get the +integration over the lagrangian and + + align:start position:0% +integration over the lagrangian and + + + align:start position:0% +integration over the lagrangian and +which is the become full integral of the + + align:start position:0% +which is the become full integral of the + + + align:start position:0% +which is the become full integral of the +logon intensity okay + + align:start position:0% +logon intensity okay + + + align:start position:0% +logon intensity okay +any questions on this + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +so whenever you get confused + + align:start position:0% +so whenever you get confused + + + align:start position:0% +so whenever you get confused +about the uh whenever you get confused + + align:start position:0% +about the uh whenever you get confused + + + align:start position:0% +about the uh whenever you get confused +about passing the going Fields Theory + + align:start position:0% +about passing the going Fields Theory + + + align:start position:0% +about passing the going Fields Theory +then try to translate + + align:start position:0% +then try to translate + + + align:start position:0% +then try to translate +into a a the language of a single + + align:start position:0% +into a a the language of a single + + + align:start position:0% +into a a the language of a single +particle okay but by doing this kind of + + align:start position:0% +particle okay but by doing this kind of + + + align:start position:0% +particle okay but by doing this kind of +replacement and then you will be able to + + align:start position:0% +replacement and then you will be able to + + + align:start position:0% +replacement and then you will be able to +settle your problem + + align:start position:0% +settle your problem + + + align:start position:0% +settle your problem +and then whenever you get confused about + + align:start position:0% +and then whenever you get confused about + + + align:start position:0% +and then whenever you get confused about +the passing the goal in this quantum + + align:start position:0% +the passing the goal in this quantum + + + align:start position:0% +the passing the goal in this quantum +mechanics + + align:start position:0% +mechanics + + + align:start position:0% +mechanics +then just retail reduce it about about + + align:start position:0% +then just retail reduce it about about + + + align:start position:0% +then just retail reduce it about about +uh reduce it by finally dimensional + + align:start position:0% +uh reduce it by finally dimensional + + + align:start position:0% +uh reduce it by finally dimensional +integral and then you should be able to + + align:start position:0% +integral and then you should be able to + + + align:start position:0% +integral and then you should be able to +understand okay just just always uh + + align:start position:0% +understand okay just just always uh + + + align:start position:0% +understand okay just just always uh +reduce it to the simple case and often + + align:start position:0% +reduce it to the simple case and often + + + align:start position:0% +reduce it to the simple case and often +your confusion can be understood in that + + align:start position:0% +your confusion can be understood in that + + + align:start position:0% +your confusion can be understood in that +simpler case okay + + align:start position:0% +simpler case okay + + + align:start position:0% +simpler case okay +and uh yeah + + align:start position:0% + + + + align:start position:0% + +good so now let me explain a little bit + + align:start position:0% +good so now let me explain a little bit + + + align:start position:0% +good so now let me explain a little bit +what what this rotation means + + align:start position:0% +what what this rotation means + + + align:start position:0% +what what this rotation means +okay so so so this says in words means + + align:start position:0% +okay so so so this says in words means + + + align:start position:0% +okay so so so this says in words means +you integrate over all possible + + align:start position:0% +you integrate over all possible + + + align:start position:0% +you integrate over all possible +configurations of Phi + + align:start position:0% +configurations of Phi + + + align:start position:0% +configurations of Phi +between T and T Prime + + align:start position:0% +between T and T Prime + + + align:start position:0% +between T and T Prime +and and with the uh the final uh the + + align:start position:0% +and and with the uh the final uh the + + + align:start position:0% +and and with the uh the final uh the +final configuration the the initial + + align:start position:0% +final configuration the the initial + + + align:start position:0% +final configuration the the initial +configuration to be Phi Prime and the + + align:start position:0% +configuration to be Phi Prime and the + + + align:start position:0% +configuration to be Phi Prime and the +final configuration to be five okay f i + + align:start position:0% +final configuration to be five okay f i + + + align:start position:0% +final configuration to be five okay f i +x and the initial TV 5 Prime X Okay so + + align:start position:0% +x and the initial TV 5 Prime X Okay so + + + align:start position:0% +x and the initial TV 5 Prime X Okay so +so so let me just say a previously txt + + align:start position:0% + + + + align:start position:0% + +if you think about it in terms of + + align:start position:0% +if you think about it in terms of + + + align:start position:0% +if you think about it in terms of +discrete case corresponding to you just + + align:start position:0% +discrete case corresponding to you just + + + align:start position:0% +discrete case corresponding to you just +sum take the product of all the I + + align:start position:0% +sum take the product of all the I + + + align:start position:0% +sum take the product of all the I +at different time with DX I okay so in + + align:start position:0% +at different time with DX I okay so in + + + align:start position:0% +at different time with DX I okay so in +the Continuum limit it's like you just + + align:start position:0% +the Continuum limit it's like you just + + + align:start position:0% +the Continuum limit it's like you just +take the product of all possible value + + align:start position:0% +take the product of all possible value + + + align:start position:0% +take the product of all possible value +of T and then the integrate over the + + align:start position:0% +of T and then the integrate over the + + + align:start position:0% +of T and then the integrate over the +value of x at that particular value of T + + align:start position:0% +value of x at that particular value of T + + + align:start position:0% +value of x at that particular value of T +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that's the meaning of this txt which + + align:start position:0% +so that's the meaning of this txt which + + + align:start position:0% +so that's the meaning of this txt which +is yeah up to a pre-factor + + align:start position:0% +is yeah up to a pre-factor + + + align:start position:0% +is yeah up to a pre-factor +corresponding to that so similarly Phi + + align:start position:0% +corresponding to that so similarly Phi + + + align:start position:0% +corresponding to that so similarly Phi +is the same thing + + align:start position:0% + + + + align:start position:0% + +so now remember 5x is the now become the + + align:start position:0% +so now remember 5x is the now become the + + + align:start position:0% +so now remember 5x is the now become the +dynamical variable so so this now become + + align:start position:0% +dynamical variable so so this now become + + + align:start position:0% +dynamical variable so so this now become +sum over + + align:start position:0% +sum over + + + align:start position:0% +sum over +take product over t + + align:start position:0% +take product over t + + + align:start position:0% +take product over t +okay + + align:start position:0% +okay + + + align:start position:0% +okay +oh yeah no no first you think of take + + align:start position:0% +oh yeah no no first you think of take + + + align:start position:0% +oh yeah no no first you think of take +product + + align:start position:0% +product + + + align:start position:0% +product +over X so this is a label of X you have + + align:start position:0% +over X so this is a label of X you have + + + align:start position:0% +over X so this is a label of X you have +so so X are the labels of Phi and you + + align:start position:0% +so so X are the labels of Phi and you + + + align:start position:0% +so so X are the labels of Phi and you +take all possible value of x + + align:start position:0% +take all possible value of x + + + align:start position:0% +take all possible value of x +and then then each of them is just like + + align:start position:0% +and then then each of them is just like + + + align:start position:0% +and then then each of them is just like +a + + align:start position:0% + + + + align:start position:0% + +okay so so just like + + align:start position:0% +okay so so just like + + + align:start position:0% +okay so so just like +you have such so many different + + align:start position:0% +you have such so many different + + + align:start position:0% +you have such so many different +variables + + align:start position:0% +variables + + + align:start position:0% +variables +each X label one or a degrees Freedom + + align:start position:0% +each X label one or a degrees Freedom + + + align:start position:0% +each X label one or a degrees Freedom +okay and then you have Phi T and now and + + align:start position:0% +okay and then you have Phi T and now and + + + align:start position:0% +okay and then you have Phi T and now and +now and then you use this one then you + + align:start position:0% +now and then you use this one then you + + + align:start position:0% +now and then you use this one then you +have + + align:start position:0% +have + + + align:start position:0% +have +p x + + align:start position:0% + + + + align:start position:0% + +D Phi + + align:start position:0% + + + + align:start position:0% + +so is it clear what this equation means + + align:start position:0% +so is it clear what this equation means + + + align:start position:0% +so is it clear what this equation means +foreign + + align:start position:0% + + + + align:start position:0% + +tells you + + align:start position:0% +tells you + + + align:start position:0% +tells you +that you have many many different the + + align:start position:0% +that you have many many different the + + + align:start position:0% +that you have many many different the +good freedom so this step is just + + align:start position:0% +good freedom so this step is just + + + align:start position:0% +good freedom so this step is just +enumerate you all possible the good + + align:start position:0% +enumerate you all possible the good + + + align:start position:0% +enumerate you all possible the good +Freedom which are labeled by X + + align:start position:0% +Freedom which are labeled by X + + + align:start position:0% +Freedom which are labeled by X +just like your standard integral if you + + align:start position:0% +just like your standard integral if you + + + align:start position:0% +just like your standard integral if you +have five dimensional integral and each + + align:start position:0% +have five dimensional integral and each + + + align:start position:0% +have five dimensional integral and each +in and then you just have a product of + + align:start position:0% +in and then you just have a product of + + + align:start position:0% +in and then you just have a product of +five different variables okay here we + + align:start position:0% +five different variables okay here we + + + align:start position:0% +five different variables okay here we +have all different possible value of x + + align:start position:0% +have all different possible value of x + + + align:start position:0% +have all different possible value of x +variables and that variable is a + + align:start position:0% +variables and that variable is a + + + align:start position:0% +variables and that variable is a +function of t + + align:start position:0% +function of t + + + align:start position:0% +function of t +and then now we use this equation and + + align:start position:0% +and then now we use this equation and + + + align:start position:0% +and then now we use this equation and +not each of them + + align:start position:0% +not each of them + + + align:start position:0% +not each of them +is like here okay and then and then now + + align:start position:0% +is like here okay and then and then now + + + align:start position:0% +is like here okay and then and then now +you have the product the all possible + + align:start position:0% +you have the product the all possible + + + align:start position:0% +you have the product the all possible +value of T and then you integrate then + + align:start position:0% +value of T and then you integrate then + + + align:start position:0% +value of T and then you integrate then +all possible values of Phi say at point + + align:start position:0% +all possible values of Phi say at point + + + align:start position:0% +all possible values of Phi say at point +x and the T + + align:start position:0% +x and the T + + + align:start position:0% +x and the T +okay but remember T always is between t + + align:start position:0% +okay but remember T always is between t + + + align:start position:0% +okay but remember T always is between t +Prime and T okay + + align:start position:0% +Prime and T okay + + + align:start position:0% +Prime and T okay +yes + + align:start position:0% + + + + align:start position:0% + +you mean here + + align:start position:0% + + + + align:start position:0% + +yeah yeah + + align:start position:0% + + + + align:start position:0% + +yeah here I just write it in the + + align:start position:0% +yeah here I just write it in the + + + align:start position:0% +yeah here I just write it in the +Continuum form + + align:start position:0% +Continuum form + + + align:start position:0% +Continuum form +so here label it by TI + + align:start position:0% +so here label it by TI + + + align:start position:0% +so here label it by TI +inside each location TI I have dxi in + + align:start position:0% +inside each location TI I have dxi in + + + align:start position:0% +inside each location TI I have dxi in +that form + + align:start position:0% + + + + align:start position:0% + +but if I go to Continuum limit and go to + + align:start position:0% +but if I go to Continuum limit and go to + + + align:start position:0% +but if I go to Continuum limit and go to +infinite limit essentially at each point + + align:start position:0% +infinite limit essentially at each point + + + align:start position:0% +infinite limit essentially at each point +T + + align:start position:0% +T + + + align:start position:0% +T +I have integration over X + + align:start position:0% +I have integration over X + + + align:start position:0% +I have integration over X +and and so that's roughly the yeah uh uh + + align:start position:0% +and and so that's roughly the yeah uh uh + + + align:start position:0% +and and so that's roughly the yeah uh uh +uh the Continuum of a form of that and + + align:start position:0% +uh the Continuum of a form of that and + + + align:start position:0% +uh the Continuum of a form of that and +and here it's similar + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +good so so so once you have load this + + align:start position:0% +good so so so once you have load this + + + align:start position:0% +good so so so once you have load this +trick + + align:start position:0% +trick + + + align:start position:0% +trick +to the reduction and I think you will be + + align:start position:0% +to the reduction and I think you will be + + + align:start position:0% +to the reduction and I think you will be +able to settle all your confusions about + + align:start position:0% +able to settle all your confusions about + + + align:start position:0% +able to settle all your confusions about +these definitions okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so other than that + + align:start position:0% +so other than that + + + align:start position:0% +so other than that +other than this additional label X + + align:start position:0% +other than this additional label X + + + align:start position:0% +other than this additional label X +okay so other than + + align:start position:0% + + + + align:start position:0% + +additional + + align:start position:0% + + + + align:start position:0% + +label + + align:start position:0% + + + + align:start position:0% + +yeah because as you called here label X + + align:start position:0% +yeah because as you called here label X + + + align:start position:0% +yeah because as you called here label X +so the field series path integral + + align:start position:0% + + + + align:start position:0% + +I'm gonna fall off + + align:start position:0% +I'm gonna fall off + + + align:start position:0% +I'm gonna fall off +a scalar field + + align:start position:0% + + + + align:start position:0% + +is essentially + + align:start position:0% + + + + align:start position:0% + +identical + + align:start position:0% + + + + align:start position:0% + +to that in-ground mechanics okay + + align:start position:0% + + + + align:start position:0% + +so just to emphasize this point + + align:start position:0% + + + + align:start position:0% + +so here actually you can Define this + + align:start position:0% +so here actually you can Define this + + + align:start position:0% +so here actually you can Define this +General it doesn't matter what your V is + + align:start position:0% +General it doesn't matter what your V is + + + align:start position:0% +General it doesn't matter what your V is +okay you can choose whatever V you want + + align:start position:0% +okay you can choose whatever V you want + + + align:start position:0% +okay you can choose whatever V you want +uh the story does not change + + align:start position:0% +uh the story does not change + + + align:start position:0% +uh the story does not change +uh just like when we do the uh when we + + align:start position:0% +uh just like when we do the uh when we + + + align:start position:0% +uh just like when we do the uh when we +do the single particle case it doesn't + + align:start position:0% +do the single particle case it doesn't + + + align:start position:0% +do the single particle case it doesn't +matter what this V is okay you can + + align:start position:0% +matter what this V is okay you can + + + align:start position:0% +matter what this V is okay you can +choose arbitrary three you want + + align:start position:0% +choose arbitrary three you want + + + align:start position:0% +choose arbitrary three you want +but if we choose V to be + + align:start position:0% +but if we choose V to be + + + align:start position:0% +but if we choose V to be +when V is the um + + align:start position:0% + + + + align:start position:0% + +for the free Theory + + align:start position:0% + + + + align:start position:0% + +then in this case of course a + + align:start position:0% +then in this case of course a + + + align:start position:0% +then in this case of course a +particularly simple and then in this + + align:start position:0% +particularly simple and then in this + + + align:start position:0% +particularly simple and then in this +case the the path integral + + align:start position:0% + + + + align:start position:0% + +is again + + align:start position:0% + + + + align:start position:0% + +causing + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so again gaussing are we allowed to + + align:start position:0% +so again gaussing are we allowed to + + + align:start position:0% +so again gaussing are we allowed to +write it again so so again that formula + + align:start position:0% +write it again so so again that formula + + + align:start position:0% +write it again so so again that formula +and the uh this formula applies + + align:start position:0% +and the uh this formula applies + + + align:start position:0% +and the uh this formula applies +just this case in a more complicated + + align:start position:0% +just this case in a more complicated + + + align:start position:0% +just this case in a more complicated +space a k is operating in a more + + align:start position:0% +space a k is operating in a more + + + align:start position:0% +space a k is operating in a more +complicated space okay so now you not + + align:start position:0% +complicated space okay so now you not + + + align:start position:0% +complicated space okay so now you not +only have the space of t but you also + + align:start position:0% +only have the space of t but you also + + + align:start position:0% +only have the space of t but you also +have the space of X okay + + align:start position:0% +have the space of X okay + + + align:start position:0% +have the space of X okay +but once you generalize to some space or + + align:start position:0% +but once you generalize to some space or + + + align:start position:0% +but once you generalize to some space or +functions doesn't matter this function + + align:start position:0% +functions doesn't matter this function + + + align:start position:0% +functions doesn't matter this function +become more complicated okay and uh so + + align:start position:0% +become more complicated okay and uh so + + + align:start position:0% +become more complicated okay and uh so +conceptually they're the same okay + + align:start position:0% +conceptually they're the same okay + + + align:start position:0% +conceptually they're the same okay +conceptually the same + + align:start position:0% + + + + align:start position:0% + +great + + align:start position:0% +great + + + align:start position:0% +great +so now for the for interacting Theory + + align:start position:0% +so now for the for interacting Theory + + + align:start position:0% +so now for the for interacting Theory +then essentially + + align:start position:0% +then essentially + + + align:start position:0% +then essentially +then the then the quantum filter will + + align:start position:0% +then the then the quantum filter will + + + align:start position:0% +then the then the quantum filter will +then reduce to two in this path integral + + align:start position:0% +then reduce to two in this path integral + + + align:start position:0% +then reduce to two in this path integral +okay if you don't know how to do this + + align:start position:0% +okay if you don't know how to do this + + + align:start position:0% +okay if you don't know how to do this +part integral and then then essentially + + align:start position:0% +part integral and then then essentially + + + align:start position:0% +part integral and then then essentially +you learn how to solve the theory okay + + align:start position:0% +you learn how to solve the theory okay + + + align:start position:0% +you learn how to solve the theory okay +you know how to solve the theory + + align:start position:0% +you know how to solve the theory + + + align:start position:0% +you know how to solve the theory +and uh so as I said in the free Siri + + align:start position:0% +and uh so as I said in the free Siri + + + align:start position:0% +and uh so as I said in the free Siri +case it's essentially reduced to + + align:start position:0% +case it's essentially reduced to + + + align:start position:0% +case it's essentially reduced to +gaussian integral then everything this + + align:start position:0% +gaussian integral then everything this + + + align:start position:0% +gaussian integral then everything this +is simple and which we will go back to + + align:start position:0% +is simple and which we will go back to + + + align:start position:0% +is simple and which we will go back to +discuss that they may you know live in + + align:start position:0% +discuss that they may you know live in + + + align:start position:0% +discuss that they may you know live in +more detail later + + align:start position:0% +more detail later + + + align:start position:0% +more detail later +and um + + align:start position:0% +and um + + + align:start position:0% +and um +now let's just think a little bit uh uh + + align:start position:0% +now let's just think a little bit uh uh + + + align:start position:0% +now let's just think a little bit uh uh +how to treat the interacting case okay + + align:start position:0% +how to treat the interacting case okay + + + align:start position:0% +how to treat the interacting case okay +so so recall our goal + + align:start position:0% + + + + align:start position:0% + +is to compute this object + + align:start position:0% +is to compute this object + + + align:start position:0% +is to compute this object +the vacuum expectation value of time + + align:start position:0% +the vacuum expectation value of time + + + align:start position:0% +the vacuum expectation value of time +ordered correlation functions + + align:start position:0% + + + + align:start position:0% + +okay we want to compute this object okay + + align:start position:0% +okay we want to compute this object okay + + + align:start position:0% +okay we want to compute this object okay +so so now we will discuss how we use + + align:start position:0% +so so now we will discuss how we use + + + align:start position:0% +so so now we will discuss how we use +passenger going to compute this object + + align:start position:0% +passenger going to compute this object + + + align:start position:0% +passenger going to compute this object +okay + + align:start position:0% + + + + align:start position:0% + +okay so before doing that + + align:start position:0% +okay so before doing that + + + align:start position:0% +okay so before doing that +let's first try to do this + + align:start position:0% +let's first try to do this + + + align:start position:0% +let's first try to do this +in uh um + + align:start position:0% +in uh um + + + align:start position:0% +in uh um +so so before doing that let's first + + align:start position:0% +so so before doing that let's first + + + align:start position:0% +so so before doing that let's first +discuss how to do this in quantum + + align:start position:0% +discuss how to do this in quantum + + + align:start position:0% +discuss how to do this in quantum +mechanics okay before doing this in + + align:start position:0% +mechanics okay before doing this in + + + align:start position:0% +mechanics okay before doing this in +field Theory and before we can just + + align:start position:0% +field Theory and before we can just + + + align:start position:0% +field Theory and before we can just +first understand how we compute the + + align:start position:0% +first understand how we compute the + + + align:start position:0% +first understand how we compute the +similar object in quantum mechanics and + + align:start position:0% +similar object in quantum mechanics and + + + align:start position:0% +similar object in quantum mechanics and +once we understand how to do that again + + align:start position:0% +once we understand how to do that again + + + align:start position:0% +once we understand how to do that again +the generation to field series will be + + align:start position:0% +the generation to field series will be + + + align:start position:0% +the generation to field series will be +straightforward + + align:start position:0% +straightforward + + + align:start position:0% +straightforward +okay + + align:start position:0% +okay + + + align:start position:0% +okay +good so so first we talk about + + align:start position:0% +good so so first we talk about + + + align:start position:0% +good so so first we talk about +time ordered + + align:start position:0% + + + + align:start position:0% + +relation function + + align:start position:0% + + + + align:start position:0% + +in quantum mechanics + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so we will be introducing a a number of + + align:start position:0% +so we will be introducing a a number of + + + align:start position:0% +so we will be introducing a a number of +tricks + + align:start position:0% +tricks + + + align:start position:0% +tricks +and those tricks will then take over + + align:start position:0% +and those tricks will then take over + + + align:start position:0% +and those tricks will then take over +to field CV okay + + align:start position:0% +to field CV okay + + + align:start position:0% +to field CV okay +then we'll be carried over to field + + align:start position:0% +then we'll be carried over to field + + + align:start position:0% +then we'll be carried over to field +series + + align:start position:0% +series + + + align:start position:0% +series +so again let's just consider this system + + align:start position:0% +so again let's just consider this system + + + align:start position:0% +so again let's just consider this system +okay let's consider system like this + + align:start position:0% +okay let's consider system like this + + + align:start position:0% +okay let's consider system like this +just visit the lagranging of this phone + + align:start position:0% +just visit the lagranging of this phone + + + align:start position:0% +just visit the lagranging of this phone +okay just one particle theory okay + + align:start position:0% +okay just one particle theory okay + + + align:start position:0% +okay just one particle theory okay +and then the analog + + align:start position:0% +and then the analog + + + align:start position:0% +and then the analog +the analog of this object + + align:start position:0% +the analog of this object + + + align:start position:0% +the analog of this object +is this object + + align:start position:0% +is this object + + + align:start position:0% +is this object +isn't it called GN + + align:start position:0% +isn't it called GN + + + align:start position:0% +isn't it called GN +would be + + align:start position:0% +would be + + + align:start position:0% +would be +say + + align:start position:0% +say + + + align:start position:0% +say +um + + align:start position:0% +um + + + align:start position:0% +um +so let's call the zero is the vacuum of + + align:start position:0% +so let's call the zero is the vacuum of + + + align:start position:0% +so let's call the zero is the vacuum of +the field Theory oh of this quantum + + align:start position:0% +the field Theory oh of this quantum + + + align:start position:0% +the field Theory oh of this quantum +mechanical system and then you have time + + align:start position:0% +mechanical system and then you have time + + + align:start position:0% +mechanical system and then you have time +ordered + + align:start position:0% +ordered + + + align:start position:0% +ordered +and then you have xt1 + + align:start position:0% +and then you have xt1 + + + align:start position:0% +and then you have xt1 +because the dynamic variable here for + + align:start position:0% +because the dynamic variable here for + + + align:start position:0% +because the dynamic variable here for +for quantum mechanics just X + + align:start position:0% +for quantum mechanics just X + + + align:start position:0% +for quantum mechanics just X +and x t n a different time + + align:start position:0% +and x t n a different time + + + align:start position:0% +and x t n a different time +and then yeah okay so we we want to + + align:start position:0% +and then yeah okay so we we want to + + + align:start position:0% +and then yeah okay so we we want to +compute such object uh uh uh in quantum + + align:start position:0% +compute such object uh uh uh in quantum + + + align:start position:0% +compute such object uh uh uh in quantum +mechanics + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so our goal + + align:start position:0% +so so our goal + + + align:start position:0% +so so our goal +is to develop techniques yeah so you + + align:start position:0% +is to develop techniques yeah so you + + + align:start position:0% +is to develop techniques yeah so you +should imagine all these are operators + + align:start position:0% +should imagine all these are operators + + + align:start position:0% +should imagine all these are operators +okay all these operators + + align:start position:0% +okay all these operators + + + align:start position:0% +okay all these operators +so our goal is to develop type links to + + align:start position:0% +so our goal is to develop type links to + + + align:start position:0% +so our goal is to develop type links to +calculate this + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so um + + align:start position:0% +so um + + + align:start position:0% +so um +so before doing that + + align:start position:0% +so before doing that + + + align:start position:0% +so before doing that +let's first understand how to unders how + + align:start position:0% +let's first understand how to unders how + + + align:start position:0% +let's first understand how to unders how +to do this time ordering + + align:start position:0% +to do this time ordering + + + align:start position:0% +to do this time ordering +uh uh using using pass integral okay how + + align:start position:0% +uh uh using using pass integral okay how + + + align:start position:0% +uh uh using using pass integral okay how +do you do the time ordering partner + + align:start position:0% +do you do the time ordering partner + + + align:start position:0% +do you do the time ordering partner +so before I do that do you have any + + align:start position:0% +so before I do that do you have any + + + align:start position:0% +so before I do that do you have any +questions + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +so it turns out actually past integral + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +some of the natural the most natural + + align:start position:0% +some of the natural the most natural + + + align:start position:0% +some of the natural the most natural +object to think about such kind of time + + align:start position:0% +object to think about such kind of time + + + align:start position:0% +object to think about such kind of time +all the correlation functions okay and + + align:start position:0% +all the correlation functions okay and + + + align:start position:0% +all the correlation functions okay and +we will see in a minute okay the the + + align:start position:0% +we will see in a minute okay the the + + + align:start position:0% +we will see in a minute okay the the +part in the exactly the most natural + + align:start position:0% +part in the exactly the most natural + + + align:start position:0% +part in the exactly the most natural +thing to uh the most natural framework + + align:start position:0% +thing to uh the most natural framework + + + align:start position:0% +thing to uh the most natural framework +to think about this kind of order + + align:start position:0% +to think about this kind of order + + + align:start position:0% +to think about this kind of order +correlation functions so before doing + + align:start position:0% +correlation functions so before doing + + + align:start position:0% +correlation functions so before doing +that let's consider one simple example + + align:start position:0% +that let's consider one simple example + + + align:start position:0% +that let's consider one simple example +okay so firstly you can see there + + align:start position:0% + + + + align:start position:0% + +so let's consider some other time T1 + + align:start position:0% +so let's consider some other time T1 + + + align:start position:0% +so let's consider some other time T1 +between t Prime and the T okay so so we + + align:start position:0% +between t Prime and the T okay so so we + + + align:start position:0% +between t Prime and the T okay so so we +can see that again we go back to this + + align:start position:0% +can see that again we go back to this + + + align:start position:0% +can see that again we go back to this +problem + + align:start position:0% +problem + + + align:start position:0% +problem +okay we go back to this problem but we + + align:start position:0% +okay we go back to this problem but we + + + align:start position:0% +okay we go back to this problem but we +can see the sometime in between t Prime + + align:start position:0% +can see the sometime in between t Prime + + + align:start position:0% +can see the sometime in between t Prime +and T okay so now let's consider this + + align:start position:0% +and T okay so now let's consider this + + + align:start position:0% +and T okay so now let's consider this +object + + align:start position:0% +object + + + align:start position:0% +object +so the simplest case of this one + + align:start position:0% +so the simplest case of this one + + + align:start position:0% +so the simplest case of this one +you just take n equal to one okay just + + align:start position:0% +you just take n equal to one okay just + + + align:start position:0% +you just take n equal to one okay just +have one of them + + align:start position:0% + + + + align:start position:0% + +let's consider the simplest case + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so as you can see that this object + + align:start position:0% +so as you can see that this object + + + align:start position:0% +so as you can see that this object +so this is easy to do + + align:start position:0% +so this is easy to do + + + align:start position:0% +so this is easy to do +we can just use the same Technique we + + align:start position:0% +we can just use the same Technique we + + + align:start position:0% +we can just use the same Technique we +used before + + align:start position:0% +used before + + + align:start position:0% +used before +so essentially + + align:start position:0% + + + + align:start position:0% + +most of tricks + + align:start position:0% +most of tricks + + + align:start position:0% +most of tricks +in quantum mechanics + + align:start position:0% + + + + align:start position:0% + +just reduce to one trick + + align:start position:0% +just reduce to one trick + + + align:start position:0% +just reduce to one trick +or yet yeah I say most of the case Okay + + align:start position:0% +or yet yeah I say most of the case Okay + + + align:start position:0% +or yet yeah I say most of the case Okay +most of the case tricks in quantum + + align:start position:0% +most of the case tricks in quantum + + + align:start position:0% +most of the case tricks in quantum +mechanics be excused to one trick uh + + align:start position:0% +mechanics be excused to one trick uh + + + align:start position:0% +mechanics be excused to one trick uh +what is that trick + + align:start position:0% +what is that trick + + + align:start position:0% +what is that trick +which we already used over and over + + align:start position:0% +which we already used over and over + + + align:start position:0% +which we already used over and over +saying driving the path integral + + align:start position:0% +saying driving the path integral + + + align:start position:0% +saying driving the path integral +yeah insert the identities + + align:start position:0% +yeah insert the identities + + + align:start position:0% +yeah insert the identities +so so if you know how to insert + + align:start position:0% +so so if you know how to insert + + + align:start position:0% +so so if you know how to insert +identities at the right location at the + + align:start position:0% +identities at the right location at the + + + align:start position:0% +identities at the right location at the +right time and essentially uh you can + + align:start position:0% +right time and essentially uh you can + + + align:start position:0% +right time and essentially uh you can +you can uh yeah you know all the tricks + + align:start position:0% +you can uh yeah you know all the tricks + + + align:start position:0% +you can uh yeah you know all the tricks +in quantum mechanics + + align:start position:0% +in quantum mechanics + + + align:start position:0% +in quantum mechanics +and so here we do the same thing + + align:start position:0% +and so here we do the same thing + + + align:start position:0% +and so here we do the same thing +so I've been since this is T1 + + align:start position:0% +so I've been since this is T1 + + + align:start position:0% +so I've been since this is T1 +so we just insert the complete set of a + + align:start position:0% +so we just insert the complete set of a + + + align:start position:0% +so we just insert the complete set of a +position against State at T1 + + align:start position:0% +position against State at T1 + + + align:start position:0% +position against State at T1 +so let's just do this + + align:start position:0% +so let's just do this + + + align:start position:0% +so let's just do this +so we integrate + + align:start position:0% + + + + align:start position:0% + +x 1 T1 + + align:start position:0% +x 1 T1 + + + align:start position:0% +x 1 T1 +okay X1 T1 + + align:start position:0% +okay X1 T1 + + + align:start position:0% +okay X1 T1 +X hat + + align:start position:0% +X hat + + + align:start position:0% +X hat +T1 + + align:start position:0% +T1 + + + align:start position:0% +T1 +keep run + + align:start position:0% +keep run + + + align:start position:0% +keep run +okay + + align:start position:0% + + + + align:start position:0% + +so so these are the + + align:start position:0% +so so these are the + + + align:start position:0% +so so these are the +so this integrates to one okay + + align:start position:0% +so this integrates to one okay + + + align:start position:0% +so this integrates to one okay +so this integrate C1 + + align:start position:0% +so this integrate C1 + + + align:start position:0% +so this integrate C1 +so since this is so since this is + + align:start position:0% +so since this is so since this is + + + align:start position:0% +so since this is so since this is +agnosticated T1 so this act on this we + + align:start position:0% +agnosticated T1 so this act on this we + + + align:start position:0% +agnosticated T1 so this act on this we +you just uh you you just get your + + align:start position:0% +you just uh you you just get your + + + align:start position:0% +you just uh you you just get your +eigenvalue + + align:start position:0% +eigenvalue + + + align:start position:0% +eigenvalue +so so we just get + + align:start position:0% +so so we just get + + + align:start position:0% +so so we just get +dx1 + + align:start position:0% +dx1 + + + align:start position:0% +dx1 +X1 so you just get eigen value + + align:start position:0% +X1 so you just get eigen value + + + align:start position:0% +X1 so you just get eigen value +and then you cut x t + + align:start position:0% +and then you cut x t + + + align:start position:0% +and then you cut x t +X1 T1 + + align:start position:0% +X1 T1 + + + align:start position:0% +X1 T1 +T1 + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% + + + + align:start position:0% + +but now + + align:start position:0% +but now + + + align:start position:0% +but now +we know how to do both of them + + align:start position:0% +we know how to do both of them + + + align:start position:0% +we know how to do both of them +we just plug in our password a a formula + + align:start position:0% +we just plug in our password a a formula + + + align:start position:0% +we just plug in our password a a formula +to uh to both of them + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so so you can do this explicitly + + align:start position:0% +so so you can do this explicitly + + + align:start position:0% +so so you can do this explicitly +plug in + + align:start position:0% +plug in + + + align:start position:0% +plug in +plug in this expression there + + align:start position:0% + + + + align:start position:0% + +okay plug in this expression there + + align:start position:0% + + + + align:start position:0% + +but it's also very intuitive you know + + align:start position:0% +but it's also very intuitive you know + + + align:start position:0% +but it's also very intuitive you know +what this looks like + + align:start position:0% +what this looks like + + + align:start position:0% +what this looks like +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so this is like the following + + align:start position:0% +so this is like the following + + + align:start position:0% +so this is like the following +so previously we + + align:start position:0% +so previously we + + + align:start position:0% +so previously we +we just do all the paths + + align:start position:0% +we just do all the paths + + + align:start position:0% +we just do all the paths +between these two + + align:start position:0% +between these two + + + align:start position:0% +between these two +okay so now + + align:start position:0% + + + + align:start position:0% + +we uh uh so now you have this x t + + align:start position:0% +we uh uh so now you have this x t + + + align:start position:0% +we uh uh so now you have this x t +and now we have T1 + + align:start position:0% +and now we have T1 + + + align:start position:0% +and now we have T1 +so suppose this is the time T1 + + align:start position:0% +so suppose this is the time T1 + + + align:start position:0% +so suppose this is the time T1 +it's suppose T goes up and so this is T + + align:start position:0% +it's suppose T goes up and so this is T + + + align:start position:0% +it's suppose T goes up and so this is T +Prime + + align:start position:0% + + + + align:start position:0% + +so suppose this is the time T1 and this + + align:start position:0% +so suppose this is the time T1 and this + + + align:start position:0% +so suppose this is the time T1 and this +is TI Prime X Prime okay + + align:start position:0% +is TI Prime X Prime okay + + + align:start position:0% +is TI Prime X Prime okay +so this corresponding to you you first + + align:start position:0% +so this corresponding to you you first + + + align:start position:0% +so this corresponding to you you first +do the path integral to to some location + + align:start position:0% +do the path integral to to some location + + + align:start position:0% +do the path integral to to some location +T1 integrate over all paths here + + align:start position:0% +T1 integrate over all paths here + + + align:start position:0% +T1 integrate over all paths here +and then you multiply X1 + + align:start position:0% +and then you multiply X1 + + + align:start position:0% +and then you multiply X1 +and then you do all the path integral + + align:start position:0% +and then you do all the path integral + + + align:start position:0% +and then you do all the path integral +here okay and then you integrate over X1 + + align:start position:0% +here okay and then you integrate over X1 + + + align:start position:0% +here okay and then you integrate over X1 +okay you integrate x y okay + + align:start position:0% +okay you integrate x y okay + + + align:start position:0% +okay you integrate x y okay +so now if you without this X1 + + align:start position:0% +so now if you without this X1 + + + align:start position:0% +so now if you without this X1 +okay if we dot X1 then of course this is + + align:start position:0% +okay if we dot X1 then of course this is + + + align:start position:0% +okay if we dot X1 then of course this is +trivially equal to the previous web + + align:start position:0% +trivially equal to the previous web + + + align:start position:0% +trivially equal to the previous web +because the uh you do all possible parts + + align:start position:0% +because the uh you do all possible parts + + + align:start position:0% +because the uh you do all possible parts +to T1 and open the bar from T1 to T and + + align:start position:0% +to T1 and open the bar from T1 to T and + + + align:start position:0% +to T1 and open the bar from T1 to T and +then you integrate over all possible + + align:start position:0% +then you integrate over all possible + + + align:start position:0% +then you integrate over all possible +location here then it's the same as you + + align:start position:0% +location here then it's the same as you + + + align:start position:0% +location here then it's the same as you +integrate from here to there uh the + + align:start position:0% +integrate from here to there uh the + + + align:start position:0% +integrate from here to there uh the +arbitrary path okay so the div the only + + align:start position:0% +arbitrary path okay so the div the only + + + align:start position:0% +arbitrary path okay so the div the only +difference is now we multiply by x y + + align:start position:0% +difference is now we multiply by x y + + + align:start position:0% +difference is now we multiply by x y +okay and the value at T1 + + align:start position:0% +okay and the value at T1 + + + align:start position:0% +okay and the value at T1 +and now we can immediately write down + + align:start position:0% +and now we can immediately write down + + + align:start position:0% +and now we can immediately write down +using pass integral what's this object + + align:start position:0% +using pass integral what's this object + + + align:start position:0% +using pass integral what's this object +so this object is essentially + + align:start position:0% +so this object is essentially + + + align:start position:0% +so this object is essentially +okay + + align:start position:0% +okay + + + align:start position:0% +okay +it's just equal to + + align:start position:0% +it's just equal to + + + align:start position:0% +it's just equal to +so now I will + + align:start position:0% +so now I will + + + align:start position:0% +so now I will +use a simplified rotation say here right + + align:start position:0% +use a simplified rotation say here right + + + align:start position:0% +use a simplified rotation say here right +X Prime T Prime x t + + align:start position:0% +X Prime T Prime x t + + + align:start position:0% +X Prime T Prime x t +to be to be those limits okay + + align:start position:0% +to be to be those limits okay + + + align:start position:0% +to be to be those limits okay +without name it + + align:start position:0% +without name it + + + align:start position:0% +without name it +and then again we integrate all possible + + align:start position:0% +and then again we integrate all possible + + + align:start position:0% +and then again we integrate all possible +Parts between them + + align:start position:0% + + + + align:start position:0% + +but then + + align:start position:0% +but then + + + align:start position:0% +but then +we just have X T1 + + align:start position:0% +we just have X T1 + + + align:start position:0% +we just have X T1 +here + + align:start position:0% + + + + align:start position:0% + +okay it just you integrate over all + + align:start position:0% +okay it just you integrate over all + + + align:start position:0% +okay it just you integrate over all +positive between them just add this time + + align:start position:0% +positive between them just add this time + + + align:start position:0% +positive between them just add this time +T1 you multiply in the integrand the + + align:start position:0% +T1 you multiply in the integrand the + + + align:start position:0% +T1 you multiply in the integrand the +value of x at one yeah so this is + + align:start position:0% +value of x at one yeah so this is + + + align:start position:0% +value of x at one yeah so this is +essentially just a the X1 here okay + + align:start position:0% +essentially just a the X1 here okay + + + align:start position:0% +essentially just a the X1 here okay +is this clear + + align:start position:0% +is this clear + + + align:start position:0% +is this clear +you can do this explicitly by plugging + + align:start position:0% +you can do this explicitly by plugging + + + align:start position:0% +you can do this explicitly by plugging +the formulas and manipulating you'll get + + align:start position:0% +the formulas and manipulating you'll get + + + align:start position:0% +the formulas and manipulating you'll get +this but it's much easier to understand + + align:start position:0% +this but it's much easier to understand + + + align:start position:0% +this but it's much easier to understand +it heuristically + + align:start position:0% +it heuristically + + + align:start position:0% +it heuristically +okay + + align:start position:0% +okay + + + align:start position:0% +okay +using a diagram + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +so + + align:start position:0% +so + + + align:start position:0% +so +so this is a very very + + align:start position:0% +so this is a very very + + + align:start position:0% +so this is a very very +suggestive + + align:start position:0% +suggestive + + + align:start position:0% +suggestive +it tells you + + align:start position:0% +it tells you + + + align:start position:0% +it tells you +when we insert or operate here + + align:start position:0% + + + + align:start position:0% + +what we do is just we translate the + + align:start position:0% +what we do is just we translate the + + + align:start position:0% +what we do is just we translate the +eigenvalue of this operator + + align:start position:0% +eigenvalue of this operator + + + align:start position:0% +eigenvalue of this operator +okay plugged it in the integrand + + align:start position:0% +okay plugged it in the integrand + + + align:start position:0% +okay plugged it in the integrand +okay plug in the integrand + + align:start position:0% +okay plug in the integrand + + + align:start position:0% +okay plug in the integrand +so so now you can do the same thing + + align:start position:0% +so so now you can do the same thing + + + align:start position:0% +so so now you can do the same thing +suppose you have + + align:start position:0% +suppose you have + + + align:start position:0% +suppose you have +two operators okay + + align:start position:0% +two operators okay + + + align:start position:0% +two operators okay +so now let's look at + + align:start position:0% + + + + align:start position:0% + +we have two operators + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so you can immediately almost + + align:start position:0% +so you can immediately almost + + + align:start position:0% +so you can immediately almost +immediately write down + + align:start position:0% +immediately write down + + + align:start position:0% +immediately write down +if you try to generalize that what would + + align:start position:0% +if you try to generalize that what would + + + align:start position:0% +if you try to generalize that what would +you write down this the uh the answer + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +good so so you just + + align:start position:0% + + + + align:start position:0% + +DX t + + align:start position:0% + + + + align:start position:0% + +but this is almost cracked + + align:start position:0% +but this is almost cracked + + + align:start position:0% +but this is almost cracked +not completely correct + + align:start position:0% +not completely correct + + + align:start position:0% +not completely correct +for one reason + + align:start position:0% +for one reason + + + align:start position:0% +for one reason +it's actually one of you asked before + + align:start position:0% +it's actually one of you asked before + + + align:start position:0% +it's actually one of you asked before +yes + + align:start position:0% + + + + align:start position:0% + +exactly this + + align:start position:0% +exactly this + + + align:start position:0% +exactly this +is only equal to that + + align:start position:0% +is only equal to that + + + align:start position:0% +is only equal to that +only when + + align:start position:0% +only when + + + align:start position:0% +only when +only for + + align:start position:0% + + + + align:start position:0% + +When Ty is greater than T Cube + + align:start position:0% +When Ty is greater than T Cube + + + align:start position:0% +When Ty is greater than T Cube +so remember + + align:start position:0% +so remember + + + align:start position:0% +so remember +all these paths they don't come back in + + align:start position:0% +all these paths they don't come back in + + + align:start position:0% +all these paths they don't come back in +time okay the at the past they go + + align:start position:0% +time okay the at the past they go + + + align:start position:0% +time okay the at the past they go +forward in time they don't come back + + align:start position:0% +forward in time they don't come back + + + align:start position:0% +forward in time they don't come back +say so so here it's like you have to uh + + align:start position:0% +say so so here it's like you have to uh + + + align:start position:0% +say so so here it's like you have to uh +insert the two uh here just insert the + + align:start position:0% +insert the two uh here just insert the + + + align:start position:0% +insert the two uh here just insert the +two sets of complete States one is here + + align:start position:0% +two sets of complete States one is here + + + align:start position:0% +two sets of complete States one is here +when it's here + + align:start position:0% +when it's here + + + align:start position:0% +when it's here +but the passing go cannot come back okay + + align:start position:0% +but the passing go cannot come back okay + + + align:start position:0% +but the passing go cannot come back okay +so the order here have to be the same as + + align:start position:0% +so the order here have to be the same as + + + align:start position:0% +so the order here have to be the same as +the ordering over the path integral + + align:start position:0% +the ordering over the path integral + + + align:start position:0% +the ordering over the path integral +okay I have to be the same ordinary + + align:start position:0% +okay I have to be the same ordinary + + + align:start position:0% +okay I have to be the same ordinary +Parts integral so that means this is + + align:start position:0% +Parts integral so that means this is + + + align:start position:0% +Parts integral so that means this is +equal + + align:start position:0% +equal + + + align:start position:0% +equal +okay or only for T1 greater than T2 + + align:start position:0% +okay or only for T1 greater than T2 + + + align:start position:0% +okay or only for T1 greater than T2 +okay + + align:start position:0% + + + + align:start position:0% + +so but + + align:start position:0% +so but + + + align:start position:0% +so but +the same thing happens + + align:start position:0% +the same thing happens + + + align:start position:0% +the same thing happens +but + + align:start position:0% +but + + + align:start position:0% +but +for T2 greater than T1 + + align:start position:0% +for T2 greater than T1 + + + align:start position:0% +for T2 greater than T1 +so suppose T2 is greater than T1 + + align:start position:0% +so suppose T2 is greater than T1 + + + align:start position:0% +so suppose T2 is greater than T1 +if you start this expression then we can + + align:start position:0% +if you start this expression then we can + + + align:start position:0% +if you start this expression then we can +ask what could the the correspond in the + + align:start position:0% +ask what could the the correspond in the + + + align:start position:0% +ask what could the the correspond in the +operated form so what do you think will + + align:start position:0% +operated form so what do you think will + + + align:start position:0% +operated form so what do you think will +be the operator form + + align:start position:0% + + + + align:start position:0% + +yeah so for for T1 greater than T2 we + + align:start position:0% +yeah so for for T1 greater than T2 we + + + align:start position:0% +yeah so for for T1 greater than T2 we +have this equal to that okay + + align:start position:0% +have this equal to that okay + + + align:start position:0% +have this equal to that okay +but now let's ask the post + + align:start position:0% +but now let's ask the post + + + align:start position:0% +but now let's ask the post +it's off the t2 greater than T1 but on + + align:start position:0% +it's off the t2 greater than T1 but on + + + align:start position:0% +it's off the t2 greater than T1 but on +the right hand side we still have this + + align:start position:0% +the right hand side we still have this + + + align:start position:0% +the right hand side we still have this +one but what should be the left hand + + align:start position:0% +one but what should be the left hand + + + align:start position:0% +one but what should be the left hand +side + + align:start position:0% + + + + align:start position:0% + +exactly just exchange X2 and T1 because + + align:start position:0% +exactly just exchange X2 and T1 because + + + align:start position:0% +exactly just exchange X2 and T1 because +because always follows the time order so + + align:start position:0% +because always follows the time order so + + + align:start position:0% +because always follows the time order so +that means the order here has always to + + align:start position:0% +that means the order here has always to + + + align:start position:0% +that means the order here has always to +be time ordered so that means that the + + align:start position:0% +be time ordered so that means that the + + + align:start position:0% +be time ordered so that means that the +correct formula which applies to for all + + align:start position:0% +correct formula which applies to for all + + + align:start position:0% +correct formula which applies to for all +T1 T2 + + align:start position:0% +T1 T2 + + + align:start position:0% +T1 T2 +it's just you time order them + + align:start position:0% + + + + align:start position:0% + +it's just your time order them + + align:start position:0% + + + + align:start position:0% + +okay so so no matter for uh for what the + + align:start position:0% +okay so so no matter for uh for what the + + + align:start position:0% +okay so so no matter for uh for what the +old value of q1 and T2 if you time order + + align:start position:0% +old value of q1 and T2 if you time order + + + align:start position:0% +old value of q1 and T2 if you time order +them so that the the X with the larger + + align:start position:0% +them so that the the X with the larger + + + align:start position:0% +them so that the the X with the larger +time always sit in the front then it's + + align:start position:0% +time always sit in the front then it's + + + align:start position:0% +time always sit in the front then it's +always equal to this one + + align:start position:0% +always equal to this one + + + align:start position:0% +always equal to this one +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so this now just immediately generalized + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so so this tells you + + align:start position:0% + + + + align:start position:0% + +because of the part in the growth in the + + align:start position:0% +because of the part in the growth in the + + + align:start position:0% +because of the part in the growth in the +past integral the time only goes forward + + align:start position:0% + + + + align:start position:0% + +the time only goes forward + + align:start position:0% + + + + align:start position:0% + +then the + + align:start position:0% +then the + + + align:start position:0% +then the +time ordering + + align:start position:0% + + + + align:start position:0% + +naturally rise + + align:start position:0% + + + + align:start position:0% + +is impossible books okay + + align:start position:0% + + + + align:start position:0% + +so you can immediately generalize this + + align:start position:0% +so you can immediately generalize this + + + align:start position:0% +so you can immediately generalize this +so for any t + + align:start position:0% + + + + align:start position:0% + +for any + + align:start position:0% +for any + + + align:start position:0% +for any +P1 + + align:start position:0% +P1 + + + align:start position:0% +P1 +TN + + align:start position:0% +TN + + + align:start position:0% +TN +between t Prime and T + + align:start position:0% +between t Prime and T + + + align:start position:0% +between t Prime and T +then you always have + + align:start position:0% +then you always have + + + align:start position:0% +then you always have +x t + + align:start position:0% +x t + + + align:start position:0% +x t +time ordered + + align:start position:0% +time ordered + + + align:start position:0% +time ordered +X hide T1 + + align:start position:0% +X hide T1 + + + align:start position:0% +X hide T1 +x t n + + align:start position:0% + + + + align:start position:0% + +0 and this is equal to + + align:start position:0% + + + + align:start position:0% + +X Prime T Prime + + align:start position:0% +X Prime T Prime + + + align:start position:0% +X Prime T Prime +x t + + align:start position:0% +x t + + + align:start position:0% +x t +x t + + align:start position:0% +x t + + + align:start position:0% +x t +and X T1 + + align:start position:0% +and X T1 + + + align:start position:0% +and X T1 +x t n + + align:start position:0% +x t n + + + align:start position:0% +x t n +exponential is + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so that's why + + align:start position:0% +so that's why + + + align:start position:0% +so that's why +why we say earlier + + align:start position:0% +why we say earlier + + + align:start position:0% +why we say earlier +that you didn't pass integral + + align:start position:0% + + + + align:start position:0% + +so our goal is to compute this object so + + align:start position:0% +so our goal is to compute this object so + + + align:start position:0% +so our goal is to compute this object so +that's why actually Union passes go to + + align:start position:0% +that's why actually Union passes go to + + + align:start position:0% +that's why actually Union passes go to +compute it is very natural + + align:start position:0% +compute it is very natural + + + align:start position:0% +compute it is very natural +because the time ordering is just very + + align:start position:0% +because the time ordering is just very + + + align:start position:0% +because the time ordering is just very +natural from the point of view of parts + + align:start position:0% +natural from the point of view of parts + + + align:start position:0% +natural from the point of view of parts +in the group okay yes + + align:start position:0% + + + + align:start position:0% + +hmm + + align:start position:0% +hmm + + + align:start position:0% +hmm +oh oh sorry sorry yeah + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% +good + + + align:start position:0% +good +good + + align:start position:0% + + + + align:start position:0% + +any question on this + + align:start position:0% +any question on this + + + align:start position:0% +any question on this +so this is a key formula + + align:start position:0% + + + + align:start position:0% + +okay so this is a key formula + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +good any questions on this + + align:start position:0% + + + + align:start position:0% + +so now we have got the time ordering + + align:start position:0% +so now we have got the time ordering + + + align:start position:0% +so now we have got the time ordering +okay now we want to compute but here is + + align:start position:0% +okay now we want to compute but here is + + + align:start position:0% +okay now we want to compute but here is +the vacuum correlation function + + align:start position:0% +the vacuum correlation function + + + align:start position:0% +the vacuum correlation function +okay so we have to actually go to the + + align:start position:0% +okay so we have to actually go to the + + + align:start position:0% +okay so we have to actually go to the +vacuum okay uh uh uh here uh it's in in + + align:start position:0% +vacuum okay uh uh uh here uh it's in in + + + align:start position:0% +vacuum okay uh uh uh here uh it's in in +such kind of between the position + + align:start position:0% +such kind of between the position + + + align:start position:0% +such kind of between the position +against state + + align:start position:0% +against state + + + align:start position:0% +against state +okay so now we have to see how to do + + align:start position:0% +okay so now we have to see how to do + + + align:start position:0% +okay so now we have to see how to do +this for the vacuum + + align:start position:0% +this for the vacuum + + + align:start position:0% +this for the vacuum +so so now let me just introduce a + + align:start position:0% +so so now let me just introduce a + + + align:start position:0% +so so now let me just introduce a +simplified rotation so let me call this + + align:start position:0% +simplified rotation so let me call this + + + align:start position:0% +simplified rotation so let me call this +whole scene X + + align:start position:0% +whole scene X + + + align:start position:0% +whole scene X +capital x okay + + align:start position:0% +capital x okay + + + align:start position:0% +capital x okay +code is hosting capital X + + align:start position:0% + + + + align:start position:0% + +so now + + align:start position:0% +so now + + + align:start position:0% +so now +so + + align:start position:0% +so + + + align:start position:0% +so +we want to consider the vacuum query + + align:start position:0% + + + + align:start position:0% + +so the idea is very simple + + align:start position:0% +so the idea is very simple + + + align:start position:0% +so the idea is very simple +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so um + + align:start position:0% + + + + align:start position:0% + +right okay + + align:start position:0% +right okay + + + align:start position:0% +right okay +so everyone who can see the a vacuum + + align:start position:0% +so everyone who can see the a vacuum + + + align:start position:0% +so everyone who can see the a vacuum +every function we want to increase it in + + align:start position:0% +every function we want to increase it in + + + align:start position:0% +every function we want to increase it in +the in the GN + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% +for + + + align:start position:0% +for +arbitrary + + align:start position:0% + + + + align:start position:0% + +T1 + + align:start position:0% +T1 + + + align:start position:0% +T1 +PN + + align:start position:0% +PN + + + align:start position:0% +PN +belongs to minus infinity to plus + + align:start position:0% +belongs to minus infinity to plus + + + align:start position:0% +belongs to minus infinity to plus +infinity okay + + align:start position:0% + + + + align:start position:0% + +so you want to compute this + + align:start position:0% + + + + align:start position:0% + +and + + align:start position:0% + + + + align:start position:0% + +okay and the GN using our rotation + + align:start position:0% +okay and the GN using our rotation + + + align:start position:0% +okay and the GN using our rotation +be not equal to zero + + align:start position:0% +be not equal to zero + + + align:start position:0% +be not equal to zero +X zero okay + + align:start position:0% + + + + align:start position:0% + +so outside the load is zero for that + + align:start position:0% +so outside the load is zero for that + + + align:start position:0% +so outside the load is zero for that +so now again + + align:start position:0% +so now again + + + align:start position:0% +so now again +we insert the company side of State + + align:start position:0% +we insert the company side of State + + + align:start position:0% +we insert the company side of State +okay again we insert the complete set of + + align:start position:0% +okay again we insert the complete set of + + + align:start position:0% +okay again we insert the complete set of +states + + align:start position:0% +states + + + align:start position:0% +states +we insert one + + align:start position:0% +we insert one + + + align:start position:0% +we insert one +equal to DX + + align:start position:0% + + + + align:start position:0% + +x t + + align:start position:0% + + + + align:start position:0% + +which is also equal to DX Prime + + align:start position:0% +which is also equal to DX Prime + + + align:start position:0% +which is also equal to DX Prime +X Prime T Prime + + align:start position:0% +X Prime T Prime + + + align:start position:0% +X Prime T Prime +X Prime T Prime + + align:start position:0% +X Prime T Prime + + + align:start position:0% +X Prime T Prime +okay + + align:start position:0% + + + + align:start position:0% + +we + + align:start position:0% +we + + + align:start position:0% +we +T equals to plus infinity + + align:start position:0% +T equals to plus infinity + + + align:start position:0% +T equals to plus infinity +and T Prime goes to minus infinity + + align:start position:0% +and T Prime goes to minus infinity + + + align:start position:0% +and T Prime goes to minus infinity +into the here + + align:start position:0% +into the here + + + align:start position:0% +into the here +okay so you insert that into here + + align:start position:0% +okay so you insert that into here + + + align:start position:0% +okay so you insert that into here +okay + + align:start position:0% + + + + align:start position:0% + +and then we find + + align:start position:0% + + + + align:start position:0% + +so yeah so let me I need a bigger space + + align:start position:0% +so yeah so let me I need a bigger space + + + align:start position:0% +so yeah so let me I need a bigger space +so let me just write it down + + align:start position:0% + + + + align:start position:0% + +so if you do that + + align:start position:0% + + + + align:start position:0% + +so this trick is General + + align:start position:0% +so this trick is General + + + align:start position:0% +so this trick is General +does not restrict to the vacuum + + align:start position:0% +does not restrict to the vacuum + + + align:start position:0% +does not restrict to the vacuum +okay so in any case evaluating any state + + align:start position:0% +okay so in any case evaluating any state + + + align:start position:0% +okay so in any case evaluating any state +you can reduce it + + align:start position:0% +you can reduce it + + + align:start position:0% +you can reduce it +to the path integral + + align:start position:0% +to the path integral + + + align:start position:0% +to the path integral +by by doing this trick + + align:start position:0% +by by doing this trick + + + align:start position:0% +by by doing this trick +of inserting this guys + + align:start position:0% +of inserting this guys + + + align:start position:0% +of inserting this guys +so then we have GN + + align:start position:0% +so then we have GN + + + align:start position:0% +so then we have GN +now just equal to + + align:start position:0% +now just equal to + + + align:start position:0% +now just equal to +now we have limit T equals to plus + + align:start position:0% +now we have limit T equals to plus + + + align:start position:0% +now we have limit T equals to plus +infinity + + align:start position:0% +infinity + + + align:start position:0% +infinity +T Prime goes to minus infinity + + align:start position:0% +T Prime goes to minus infinity + + + align:start position:0% +T Prime goes to minus infinity +then we have DX DX Prime + + align:start position:0% +then we have DX DX Prime + + + align:start position:0% +then we have DX DX Prime +so we insert one here + + align:start position:0% +so we insert one here + + + align:start position:0% +so we insert one here +and the one here okay in both places + + align:start position:0% +and the one here okay in both places + + + align:start position:0% +and the one here okay in both places +here we insert the upper line here we + + align:start position:0% +here we insert the upper line here we + + + align:start position:0% +here we insert the upper line here we +insert the lower line okay + + align:start position:0% +insert the lower line okay + + + align:start position:0% +insert the lower line okay +then we have + + align:start position:0% +then we have + + + align:start position:0% +then we have +zero + + align:start position:0% +zero + + + align:start position:0% +zero +X + + align:start position:0% +X + + + align:start position:0% +X +t + + align:start position:0% +t + + + align:start position:0% +t +then x t + + align:start position:0% + + + + align:start position:0% + +X + + align:start position:0% +X + + + align:start position:0% +X +X Prime T Prime + + align:start position:0% +X Prime T Prime + + + align:start position:0% +X Prime T Prime +and then X Prime T Prime + + align:start position:0% +and then X Prime T Prime + + + align:start position:0% +and then X Prime T Prime +than zero + + align:start position:0% +than zero + + + align:start position:0% +than zero +okay times + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so now + + align:start position:0% + + + + align:start position:0% + +we just have + + align:start position:0% +we just have + + + align:start position:0% +we just have +yeah so so let me just save some + + align:start position:0% +yeah so so let me just save some + + + align:start position:0% +yeah so so let me just save some +so so this then become + + align:start position:0% +so so this then become + + + align:start position:0% +so so this then become +DX DX Prime + + align:start position:0% +DX DX Prime + + + align:start position:0% +DX DX Prime +so these two are simple + + align:start position:0% + + + + align:start position:0% + +so essentially they just become the + + align:start position:0% +so essentially they just become the + + + align:start position:0% +so essentially they just become the +vacuum + + align:start position:0% +vacuum + + + align:start position:0% +vacuum +a wave function + + align:start position:0% +a wave function + + + align:start position:0% +a wave function +okay so we have + + align:start position:0% +okay so we have + + + align:start position:0% +okay so we have +PSI zero + + align:start position:0% +PSI zero + + + align:start position:0% +PSI zero +star + + align:start position:0% +star + + + align:start position:0% +star +X and say 0 x Prime + + align:start position:0% +X and say 0 x Prime + + + align:start position:0% +X and say 0 x Prime +and then we have this path integral + + align:start position:0% +and then we have this path integral + + + align:start position:0% +and then we have this path integral +which we already know how to do + + align:start position:0% +which we already know how to do + + + align:start position:0% +which we already know how to do +okay we already and then we have this + + align:start position:0% +okay we already and then we have this + + + align:start position:0% +okay we already and then we have this +pass integral + + align:start position:0% +pass integral + + + align:start position:0% +pass integral +okay then we have that path in the group + + align:start position:0% +okay then we have that path in the group + + + align:start position:0% +okay then we have that path in the group +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +yeah so so so so you just insert + + align:start position:0% +yeah so so so so you just insert + + + align:start position:0% +yeah so so so so you just insert +so let me call Star you just insert the + + align:start position:0% +so let me call Star you just insert the + + + align:start position:0% +so let me call Star you just insert the +star here + + align:start position:0% +star here + + + align:start position:0% +star here +okay + + align:start position:0% + + + + align:start position:0% + +and now with t and t Prime uh to + + align:start position:0% +and now with t and t Prime uh to + + + align:start position:0% +and now with t and t Prime uh to +Infinity okay everything finds Infinity + + align:start position:0% +Infinity okay everything finds Infinity + + + align:start position:0% +Infinity okay everything finds Infinity +and this yeah the reason we take T Prime + + align:start position:0% +and this yeah the reason we take T Prime + + + align:start position:0% +and this yeah the reason we take T Prime +and T got Infinity is obvious because we + + align:start position:0% +and T got Infinity is obvious because we + + + align:start position:0% +and T got Infinity is obvious because we +want to include + + align:start position:0% +want to include + + + align:start position:0% +want to include +so here the T have to be go between the + + align:start position:0% +so here the T have to be go between the + + + align:start position:0% +so here the T have to be go between the +T Prime and the T so if you want to have + + align:start position:0% +T Prime and the T so if you want to have + + + align:start position:0% +T Prime and the T so if you want to have +arbitrary t + + align:start position:0% +arbitrary t + + + align:start position:0% +arbitrary t +and then we want to the uh T Prime to go + + align:start position:0% +and then we want to the uh T Prime to go + + + align:start position:0% +and then we want to the uh T Prime to go +to minus infinity and t equal to plus + + align:start position:0% +to minus infinity and t equal to plus + + + align:start position:0% +to minus infinity and t equal to plus +infinity + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so we have used that the + + align:start position:0% +so we have used that the + + + align:start position:0% +so we have used that the +X + + align:start position:0% +X + + + align:start position:0% +X +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +P Prime 0 is just equal to size zero + + align:start position:0% +P Prime 0 is just equal to size zero + + + align:start position:0% +P Prime 0 is just equal to size zero +X Prime just the ground state wave + + align:start position:0% +X Prime just the ground state wave + + + align:start position:0% +X Prime just the ground state wave +function okay + + align:start position:0% + + + + align:start position:0% + +so that means that so this trick + + align:start position:0% +so that means that so this trick + + + align:start position:0% +so that means that so this trick +actually works in in uh for other states + + align:start position:0% +actually works in in uh for other states + + + align:start position:0% +actually works in in uh for other states +too okay you can do the similar trick + + align:start position:0% +too okay you can do the similar trick + + + align:start position:0% +too okay you can do the similar trick +and uh and you just + + align:start position:0% +and uh and you just + + + align:start position:0% +and uh and you just +essentially get two more integrals to do + + align:start position:0% +essentially get two more integrals to do + + + align:start position:0% +essentially get two more integrals to do +and uh you take that path integral and + + align:start position:0% +and uh you take that path integral and + + + align:start position:0% +and uh you take that path integral and +then you just uh integrate it over the + + align:start position:0% +then you just uh integrate it over the + + + align:start position:0% +then you just uh integrate it over the +initial and the final wave functions + + align:start position:0% +initial and the final wave functions + + + align:start position:0% +initial and the final wave functions +okay an integrate of ignition the follow + + align:start position:0% +okay an integrate of ignition the follow + + + align:start position:0% +okay an integrate of ignition the follow +wave functions + + align:start position:0% +wave functions + + + align:start position:0% +wave functions +so so the trick applies to any state + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +you understand not just the vacuum + + align:start position:0% +you understand not just the vacuum + + + align:start position:0% +you understand not just the vacuum +correlation functions + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +this the energy + + align:start position:0% + + + + align:start position:0% + +yeah sorry say it again + + align:start position:0% + + + + align:start position:0% + +yeah yeah yeah it's a wrong State it's + + align:start position:0% +yeah yeah yeah it's a wrong State it's + + + align:start position:0% +yeah yeah yeah it's a wrong State it's +the it's the lowest energizing State + + align:start position:0% +the it's the lowest energizing State + + + align:start position:0% +the it's the lowest energizing State +yeah yeah it doesn't matter you can also + + align:start position:0% +yeah yeah it doesn't matter you can also + + + align:start position:0% +yeah yeah it doesn't matter you can also +take a other + + align:start position:0% +take a other + + + align:start position:0% +take a other +you can take other states too it just + + align:start position:0% +you can take other states too it just + + + align:start position:0% +you can take other states too it just +will be some wave function too yeah will + + align:start position:0% +will be some wave function too yeah will + + + align:start position:0% +will be some wave function too yeah will +be some wave function there + + align:start position:0% +be some wave function there + + + align:start position:0% +be some wave function there +yes + + align:start position:0% + + + + align:start position:0% + +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +oh yeah yeah if you're not take yeah + + align:start position:0% +oh yeah yeah if you're not take yeah + + + align:start position:0% +oh yeah yeah if you're not take yeah +that's a very good question so if you + + align:start position:0% +that's a very good question so if you + + + align:start position:0% +that's a very good question so if you +don't take + + align:start position:0% +don't take + + + align:start position:0% +don't take +uh so if you take other states + + align:start position:0% +uh so if you take other states + + + align:start position:0% +uh so if you take other states +and then in general there may be some + + align:start position:0% +and then in general there may be some + + + align:start position:0% +and then in general there may be some +dependence on T and T Prime and T in + + align:start position:0% +dependence on T and T Prime and T in + + + align:start position:0% +dependence on T and T Prime and T in +this wave function yeah indeed yeah + + align:start position:0% +this wave function yeah indeed yeah + + + align:start position:0% +this wave function yeah indeed yeah +so and so you have to take the limit + + align:start position:0% +so and so you have to take the limit + + + align:start position:0% +so and so you have to take the limit +also in the wave function + + align:start position:0% +also in the wave function + + + align:start position:0% +also in the wave function +yeah but here we are using the + + align:start position:0% +yeah but here we are using the + + + align:start position:0% +yeah but here we are using the +simplification that the the ground state + + align:start position:0% +simplification that the the ground state + + + align:start position:0% +simplification that the the ground state +is actually time independent good that's + + align:start position:0% +is actually time independent good that's + + + align:start position:0% +is actually time independent good that's +a good question + + align:start position:0% +a good question + + + align:start position:0% +a good question +other questions + + align:start position:0% + + + + align:start position:0% + +okay good + + align:start position:0% +okay good + + + align:start position:0% +okay good +so this works essentially + + align:start position:0% +so this works essentially + + + align:start position:0% +so this works essentially +for any state + + align:start position:0% + + + + align:start position:0% + +but for the ground state actually + + align:start position:0% +but for the ground state actually + + + align:start position:0% +but for the ground state actually +there's another trick + + align:start position:0% +there's another trick + + + align:start position:0% +there's another trick +which can simplify the problem + + align:start position:0% +which can simplify the problem + + + align:start position:0% +which can simplify the problem +which you don't even have to do this two + + align:start position:0% +which you don't even have to do this two + + + align:start position:0% +which you don't even have to do this two +additional integral + + align:start position:0% +additional integral + + + align:start position:0% +additional integral +okay you can actually directly + + align:start position:0% +okay you can actually directly + + + align:start position:0% +okay you can actually directly +so for the ground state + + align:start position:0% + + + + align:start position:0% + +for the vacuum + + align:start position:0% + + + + align:start position:0% + +this actually + + align:start position:0% +this actually + + + align:start position:0% +this actually +another + + align:start position:0% +another + + + align:start position:0% +another +trick + + align:start position:0% + + + + align:start position:0% + +to get rid of + + align:start position:0% + + + + align:start position:0% + +to get to make the + + align:start position:0% + + + + align:start position:0% + +these two additional integrals are + + align:start position:0% +these two additional integrals are + + + align:start position:0% +these two additional integrals are +necessary + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so now let me tell you how you do this + + align:start position:0% +so now let me tell you how you do this + + + align:start position:0% +so now let me tell you how you do this +trick and this trick is very important + + align:start position:0% +trick and this trick is very important + + + align:start position:0% +trick and this trick is very important +also in Quantum field series + + align:start position:0% +also in Quantum field series + + + align:start position:0% +also in Quantum field series +because if you do harmonic oscillator of + + align:start position:0% +because if you do harmonic oscillator of + + + align:start position:0% +because if you do harmonic oscillator of +course + + align:start position:0% +course + + + align:start position:0% +course +you know the wave function + + align:start position:0% +you know the wave function + + + align:start position:0% +you know the wave function +but if I give you a harmonic oscillator + + align:start position:0% +but if I give you a harmonic oscillator + + + align:start position:0% +but if I give you a harmonic oscillator +which we don't know how to solve the way + + align:start position:0% +which we don't know how to solve the way + + + align:start position:0% +which we don't know how to solve the way +the gun State wave function and then + + align:start position:0% +the gun State wave function and then + + + align:start position:0% +the gun State wave function and then +this then this will be a nightmare okay + + align:start position:0% +this then this will be a nightmare okay + + + align:start position:0% +this then this will be a nightmare okay +because then you don't know the wave + + align:start position:0% +because then you don't know the wave + + + align:start position:0% +because then you don't know the wave +function and for Quantum field theory in + + align:start position:0% +function and for Quantum field theory in + + + align:start position:0% +function and for Quantum field theory in +particular in the interacting case we + + align:start position:0% +particular in the interacting case we + + + align:start position:0% +particular in the interacting case we +don't know the wave function + + align:start position:0% +don't know the wave function + + + align:start position:0% +don't know the wave function +okay so so so so so so even though this + + align:start position:0% +okay so so so so so so even though this + + + align:start position:0% +okay so so so so so so even though this +formally give you the answer + + align:start position:0% +formally give you the answer + + + align:start position:0% +formally give you the answer +but in practice it's actually often not + + align:start position:0% +but in practice it's actually often not + + + align:start position:0% +but in practice it's actually often not +convenient to use + + align:start position:0% +convenient to use + + + align:start position:0% +convenient to use +but fortunately for the ground state + + align:start position:0% +but fortunately for the ground state + + + align:start position:0% +but fortunately for the ground state +there's additional trick which actually + + align:start position:0% +there's additional trick which actually + + + align:start position:0% +there's additional trick which actually +you don't need to use the ground state + + align:start position:0% +you don't need to use the ground state + + + align:start position:0% +you don't need to use the ground state +wave function tool okay so so now I'm uh + + align:start position:0% +wave function tool okay so so now I'm uh + + + align:start position:0% +wave function tool okay so so now I'm uh +so now I tell you this additional tube + + align:start position:0% +so now I tell you this additional tube + + + align:start position:0% +so now I tell you this additional tube +but this trick only specific to the + + align:start position:0% +but this trick only specific to the + + + align:start position:0% +but this trick only specific to the +vacuum okay you cannot apply to other + + align:start position:0% +vacuum okay you cannot apply to other + + + align:start position:0% +vacuum okay you cannot apply to other +states + + align:start position:0% +states + + + align:start position:0% +states +okay so this is specific to vacuum + + align:start position:0% +okay so this is specific to vacuum + + + align:start position:0% +okay so this is specific to vacuum +so + + align:start position:0% +so + + + align:start position:0% +so +so now let's forget about this scene + + align:start position:0% +so now let's forget about this scene + + + align:start position:0% +so now let's forget about this scene +okay now let's forget about this scene + + align:start position:0% +okay now let's forget about this scene + + + align:start position:0% +okay now let's forget about this scene +stop + + align:start position:0% +stop + + + align:start position:0% +stop +coming back from here okay + + align:start position:0% +coming back from here okay + + + align:start position:0% +coming back from here okay +so nowadays coming back from here now + + align:start position:0% +so nowadays coming back from here now + + + align:start position:0% +so nowadays coming back from here now +let's coming back from here just + + align:start position:0% +let's coming back from here just + + + align:start position:0% +let's coming back from here just +consider + + align:start position:0% + + + + align:start position:0% + +again I take + + align:start position:0% +again I take + + + align:start position:0% +again I take +limit he goes to plus infinity + + align:start position:0% +limit he goes to plus infinity + + + align:start position:0% +limit he goes to plus infinity +and T Prime goes to minus infinity + + align:start position:0% +and T Prime goes to minus infinity + + + align:start position:0% +and T Prime goes to minus infinity +let's look at this object + + align:start position:0% +let's look at this object + + + align:start position:0% +let's look at this object +x t + + align:start position:0% +x t + + + align:start position:0% +x t +X + + align:start position:0% +X + + + align:start position:0% +X +X Prime T Prime okay + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now + + align:start position:0% +so now + + + align:start position:0% +so now +again we are going to + + align:start position:0% +again we are going to + + + align:start position:0% +again we are going to +insert identity okay now we are again + + align:start position:0% +insert identity okay now we are again + + + align:start position:0% +insert identity okay now we are again +going to insert the identity and now we + + align:start position:0% +going to insert the identity and now we + + + align:start position:0% +going to insert the identity and now we +insert the identity in a different way + + align:start position:0% +insert the identity in a different way + + + align:start position:0% +insert the identity in a different way +again we insert the identity here + + align:start position:0% +again we insert the identity here + + + align:start position:0% +again we insert the identity here +I mean so the identity here + + align:start position:0% + + + + align:start position:0% + +but now we instead identity expressed + + align:start position:0% +but now we instead identity expressed + + + align:start position:0% +but now we instead identity expressed +in the company side of energizing States + + align:start position:0% +in the company side of energizing States + + + align:start position:0% +in the company side of energizing States +okay so now we saw inserted the complete + + align:start position:0% +okay so now we saw inserted the complete + + + align:start position:0% +okay so now we saw inserted the complete +set of energizing state + + align:start position:0% +set of energizing state + + + align:start position:0% +set of energizing state +so I just formally labeled it by m + + align:start position:0% +so I just formally labeled it by m + + + align:start position:0% +so I just formally labeled it by m +okay + + align:start position:0% + + + + align:start position:0% + +so now let's just insert in the two + + align:start position:0% +so now let's just insert in the two + + + align:start position:0% +so now let's just insert in the two +places + + align:start position:0% +places + + + align:start position:0% +places +okay + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +okay so so so we now we have two + + align:start position:0% +okay so so so we now we have two + + + align:start position:0% +okay so so so we now we have two +identities then we have n and M + + align:start position:0% + + + + align:start position:0% + +we have n m + + align:start position:0% +we have n m + + + align:start position:0% +we have n m +so now I will uh so you keep this in + + align:start position:0% +so now I will uh so you keep this in + + + align:start position:0% +so now I will uh so you keep this in +mind I will not + + align:start position:0% +mind I will not + + + align:start position:0% +mind I will not +copy this over and over okay so keep + + align:start position:0% +copy this over and over okay so keep + + + align:start position:0% +copy this over and over okay so keep +this limit in mind oh it's t Prime + + align:start position:0% +this limit in mind oh it's t Prime + + + align:start position:0% +this limit in mind oh it's t Prime +equals to minus infinity + + align:start position:0% + + + + align:start position:0% + +so now we have and then we have x t + + align:start position:0% +so now we have and then we have x t + + + align:start position:0% +so now we have and then we have x t +with m + + align:start position:0% +with m + + + align:start position:0% +with m +and m x + + align:start position:0% +and m x + + + align:start position:0% +and m x +with n + + align:start position:0% +with n + + + align:start position:0% +with n +and N with X Prime T Prime + + align:start position:0% +and N with X Prime T Prime + + + align:start position:0% +and N with X Prime T Prime +okay + + align:start position:0% + + + + align:start position:0% + +so now if we look at this sum + + align:start position:0% + + + + align:start position:0% + +so now if we look at this sum + + align:start position:0% + + + + align:start position:0% + +it well n and m equal to zero + + align:start position:0% +it well n and m equal to zero + + + align:start position:0% +it well n and m equal to zero +this is the object we want + + align:start position:0% +this is the object we want + + + align:start position:0% +this is the object we want +okay + + align:start position:0% +okay + + + align:start position:0% +okay +this is the object we want but this also + + align:start position:0% +this is the object we want but this also + + + align:start position:0% +this is the object we want but this also +contains many many other + + align:start position:0% +contains many many other + + + align:start position:0% +contains many many other +stuff + + align:start position:0% +stuff + + + align:start position:0% +stuff +so now we will use a trick + + align:start position:0% +so now we will use a trick + + + align:start position:0% +so now we will use a trick +to isolate n equal to 0 and m equal to + + align:start position:0% +to isolate n equal to 0 and m equal to + + + align:start position:0% +to isolate n equal to 0 and m equal to +zero piece + + align:start position:0% +zero piece + + + align:start position:0% +zero piece +okay to isolate that piece okay + + align:start position:0% +okay to isolate that piece okay + + + align:start position:0% +okay to isolate that piece okay +that's what we are going to do now + + align:start position:0% + + + + align:start position:0% + +so this is the commonly + + align:start position:0% +so this is the commonly + + + align:start position:0% +so this is the commonly +used + + align:start position:0% +used + + + align:start position:0% +used +technique + + align:start position:0% +technique + + + align:start position:0% +technique +in Quantum field Theory + + align:start position:0% +in Quantum field Theory + + + align:start position:0% +in Quantum field Theory +not only in Quantum velocity actually in + + align:start position:0% +not only in Quantum velocity actually in + + + align:start position:0% +not only in Quantum velocity actually in +in many areas of physics + + align:start position:0% +in many areas of physics + + + align:start position:0% +in many areas of physics +um + + align:start position:0% +um + + + align:start position:0% +um +so um so now let's first to explain that + + align:start position:0% +so um so now let's first to explain that + + + align:start position:0% +so um so now let's first to explain that +you can just look at this object + + align:start position:0% + + + + align:start position:0% + +so let's look at this object okay + + align:start position:0% + + + + align:start position:0% + +so this object is + + align:start position:0% +so this object is + + + align:start position:0% +so this object is +limit T Prime goes to minus infinity + + align:start position:0% +limit T Prime goes to minus infinity + + + align:start position:0% +limit T Prime goes to minus infinity +some energizing State n and X Prime T + + align:start position:0% +some energizing State n and X Prime T + + + align:start position:0% +some energizing State n and X Prime T +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +so again this is written in the + + align:start position:0% +so again this is written in the + + + align:start position:0% +so again this is written in the +Heisenberg picture + + align:start position:0% +Heisenberg picture + + + align:start position:0% +Heisenberg picture +so we need to so translate to you more + + align:start position:0% +so we need to so translate to you more + + + align:start position:0% +so we need to so translate to you more +familiar + + align:start position:0% +familiar + + + align:start position:0% +familiar +language of the shorting a picture so we + + align:start position:0% +language of the shorting a picture so we + + + align:start position:0% +language of the shorting a picture so we +need to write it as + + align:start position:0% + + + + align:start position:0% + +n + + align:start position:0% +n + + + align:start position:0% +n +and then you have expansion i h t Prime + + align:start position:0% +and then you have expansion i h t Prime + + + align:start position:0% +and then you have expansion i h t Prime +and then X Prime okay so now it's the + + align:start position:0% +and then X Prime okay so now it's the + + + align:start position:0% +and then X Prime okay so now it's the +standard shooting a picture + + align:start position:0% +standard shooting a picture + + + align:start position:0% +standard shooting a picture +state + + align:start position:0% + + + + align:start position:0% + +so now since n is in the jagging state + + align:start position:0% +so now since n is in the jagging state + + + align:start position:0% +so now since n is in the jagging state +we can just act the uh this one okay so + + align:start position:0% +we can just act the uh this one okay so + + + align:start position:0% +we can just act the uh this one okay so +this is just equal to + + align:start position:0% +this is just equal to + + + align:start position:0% +this is just equal to +limit T Prime equals to minus infinity + + align:start position:0% +limit T Prime equals to minus infinity + + + align:start position:0% +limit T Prime equals to minus infinity +foreign + + align:start position:0% + + + + align:start position:0% + +and X Prime + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so now + + align:start position:0% +so now + + + align:start position:0% +so now +we will + + align:start position:0% +we will + + + align:start position:0% +we will +try to select the ground state + + align:start position:0% +try to select the ground state + + + align:start position:0% +try to select the ground state +and we do that by doing the following + + align:start position:0% + + + + align:start position:0% + +so now imagine + + align:start position:0% + + + + align:start position:0% + +giving en a small imaginary part + + align:start position:0% +giving en a small imaginary part + + + align:start position:0% +giving en a small imaginary part +okay + + align:start position:0% + + + + align:start position:0% + +okay imagine yeah take + + align:start position:0% +okay imagine yeah take + + + align:start position:0% +okay imagine yeah take +en + + align:start position:0% +en + + + align:start position:0% +en +goes to + + align:start position:0% +goes to + + + align:start position:0% +goes to +e n y minus i absolute + + align:start position:0% +e n y minus i absolute + + + align:start position:0% +e n y minus i absolute +hmm + + align:start position:0% + + + + align:start position:0% + +so Epson is a small positive number + + align:start position:0% + + + + align:start position:0% + +okay so which is equivalent to taking + + align:start position:0% +okay so which is equivalent to taking + + + align:start position:0% +okay so which is equivalent to taking +so or you just take H your hamiltonian + + align:start position:0% +so or you just take H your hamiltonian + + + align:start position:0% +so or you just take H your hamiltonian +take it into one minus Epsilon + + align:start position:0% +take it into one minus Epsilon + + + align:start position:0% +take it into one minus Epsilon +you can make a give you the hamiltonian + + align:start position:0% +you can make a give you the hamiltonian + + + align:start position:0% +you can make a give you the hamiltonian +a slightly imaginary part okay it's + + align:start position:0% +a slightly imaginary part okay it's + + + align:start position:0% +a slightly imaginary part okay it's +equivalent okay + + align:start position:0% +equivalent okay + + + align:start position:0% +equivalent okay +so now with this + + align:start position:0% + + + + align:start position:0% + +with this + + align:start position:0% +with this + + + align:start position:0% +with this +and now we have + + align:start position:0% + + + + align:start position:0% + +so limit + + align:start position:0% +so limit + + + align:start position:0% +so limit +P Prime goes to minus infinity + + align:start position:0% + + + + align:start position:0% + +so now we have experiential + + align:start position:0% +so now we have experiential + + + align:start position:0% +so now we have experiential +i e n + + align:start position:0% + + + + align:start position:0% + +one minus I Epsilon t + + align:start position:0% +one minus I Epsilon t + + + align:start position:0% +one minus I Epsilon t +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +and N X Prime + + align:start position:0% +and N X Prime + + + align:start position:0% +and N X Prime +okay + + align:start position:0% + + + + align:start position:0% + +so this is just equal to that + + align:start position:0% + + + + align:start position:0% + +so now you see + + align:start position:0% + + + + align:start position:0% + +supposed to be normalized our state + + align:start position:0% +supposed to be normalized our state + + + align:start position:0% +supposed to be normalized our state +so that easier yeah so so by definition + + align:start position:0% +so that easier yeah so so by definition + + + align:start position:0% +so that easier yeah so so by definition +en are greater than e0 + + align:start position:0% + + + + align:start position:0% + +greater than e0 for n greater than zero + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so the effect of this + + align:start position:0% +so the effect of this + + + align:start position:0% +so the effect of this +putting apps on here + + align:start position:0% +putting apps on here + + + align:start position:0% +putting apps on here +when you multiply it + + align:start position:0% +when you multiply it + + + align:start position:0% +when you multiply it +is to give you a factor like this + + align:start position:0% +is to give you a factor like this + + + align:start position:0% +is to give you a factor like this +explain + + align:start position:0% +explain + + + align:start position:0% +explain +Epsilon e n + + align:start position:0% +Epsilon e n + + + align:start position:0% +Epsilon e n +times T Prime okay so it'll give you a + + align:start position:0% +times T Prime okay so it'll give you a + + + align:start position:0% +times T Prime okay so it'll give you a +real Factor like this + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so now T go t Prime goes to minus + + align:start position:0% +so now T go t Prime goes to minus + + + align:start position:0% +so now T go t Prime goes to minus +infinity + + align:start position:0% + + + + align:start position:0% + +and e n is greater than e0 + + align:start position:0% +and e n is greater than e0 + + + align:start position:0% +and e n is greater than e0 +so for any state + + align:start position:0% +so for any state + + + align:start position:0% +so for any state +which is not ground state will this + + align:start position:0% +which is not ground state will this + + + align:start position:0% +which is not ground state will this +Factor will be experientially small it + + align:start position:0% +Factor will be experientially small it + + + align:start position:0% +Factor will be experientially small it +goes to zero so the ratio between this + + align:start position:0% +goes to zero so the ratio between this + + + align:start position:0% +goes to zero so the ratio between this +factor and the ground state goes to zero + + align:start position:0% +factor and the ground state goes to zero + + + align:start position:0% +factor and the ground state goes to zero +for any excited States + + align:start position:0% +for any excited States + + + align:start position:0% +for any excited States +okay + + align:start position:0% +okay + + + align:start position:0% +okay +because of the e n minus e0 or greater + + align:start position:0% +because of the e n minus e0 or greater + + + align:start position:0% +because of the e n minus e0 or greater +than zero okay and this goes to minus + + align:start position:0% +than zero okay and this goes to minus + + + align:start position:0% +than zero okay and this goes to minus +infinity and Epsilon is positive okay + + align:start position:0% + + + + align:start position:0% + +so so this implies + + align:start position:0% + + + + align:start position:0% + +so so this implies so so we continue + + align:start position:0% +so so this implies so so we continue + + + align:start position:0% +so so this implies so so we continue +sorry it's just uh so let's continue + + align:start position:0% +sorry it's just uh so let's continue + + + align:start position:0% +sorry it's just uh so let's continue +over here + + align:start position:0% +over here + + + align:start position:0% +over here +so this means + + align:start position:0% +so this means + + + align:start position:0% +so this means +we get + + align:start position:0% + + + + align:start position:0% + +essentially zero + + align:start position:0% +essentially zero + + + align:start position:0% +essentially zero +for m not equal to zero + + align:start position:0% +for m not equal to zero + + + align:start position:0% +for m not equal to zero +and therefore an expression i e zero + + align:start position:0% +and therefore an expression i e zero + + + align:start position:0% +and therefore an expression i e zero +y minus Epsilon T Prime + + align:start position:0% + + + + align:start position:0% + +for n equal to zero + + align:start position:0% +for n equal to zero + + + align:start position:0% +for n equal to zero +okay + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +you just take out the overall Factor + + align:start position:0% +you just take out the overall Factor + + + align:start position:0% +you just take out the overall Factor +corresponding to the ground state + + align:start position:0% + + + + align:start position:0% + +yeah then all the other coefficient will + + align:start position:0% +yeah then all the other coefficient will + + + align:start position:0% +yeah then all the other coefficient will +go to zero + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +it's a mathematical trick + + align:start position:0% +it's a mathematical trick + + + align:start position:0% +it's a mathematical trick +and at the end of the day we said + + align:start position:0% +and at the end of the day we said + + + align:start position:0% +and at the end of the day we said +Epsilon go to zero + + align:start position:0% +Epsilon go to zero + + + align:start position:0% +Epsilon go to zero +and you just go back to the original + + align:start position:0% +and you just go back to the original + + + align:start position:0% +and you just go back to the original +hamiltonian so this is just a trick if + + align:start position:0% +hamiltonian so this is just a trick if + + + align:start position:0% +hamiltonian so this is just a trick if +you're doing this order properly it just + + align:start position:0% +you're doing this order properly it just + + + align:start position:0% +you're doing this order properly it just +laterally selects the ground state for + + align:start position:0% +laterally selects the ground state for + + + align:start position:0% +laterally selects the ground state for +you + + align:start position:0% +you + + + align:start position:0% +you +yeah yeah just a pure mathematical trick + + align:start position:0% +yeah yeah just a pure mathematical trick + + + align:start position:0% +yeah yeah just a pure mathematical trick +yes + + align:start position:0% + + + + align:start position:0% + +yeah I have some uh for me write this + + align:start position:0% +yeah I have some uh for me write this + + + align:start position:0% +yeah I have some uh for me write this +absent we always assume Epson is greater + + align:start position:0% +absent we always assume Epson is greater + + + align:start position:0% +absent we always assume Epson is greater +than zero + + align:start position:0% +than zero + + + align:start position:0% +than zero +so uh so yeah yeah + + align:start position:0% +so uh so yeah yeah + + + align:start position:0% +so uh so yeah yeah +you always assume uh yeah + + align:start position:0% + + + + align:start position:0% + +oh I can + + align:start position:0% +oh I can + + + align:start position:0% +oh I can +uh um + + align:start position:0% +uh um + + + align:start position:0% +uh um +I have a path integral + + align:start position:0% +I have a path integral + + + align:start position:0% +I have a path integral +and uh + + align:start position:0% +and uh + + + align:start position:0% +and uh +essentially that I can design the rule I + + align:start position:0% +essentially that I can design the rule I + + + align:start position:0% +essentially that I can design the rule I +want + + align:start position:0% +want + + + align:start position:0% +want +as far as at the end of the day I get + + align:start position:0% +as far as at the end of the day I get + + + align:start position:0% +as far as at the end of the day I get +the uh the desired desired quantity yeah + + align:start position:0% +the uh the desired desired quantity yeah + + + align:start position:0% +the uh the desired desired quantity yeah +yeah but but the order of limit is very + + align:start position:0% +yeah but but the order of limit is very + + + align:start position:0% +yeah but but the order of limit is very +important you have to be very careful + + align:start position:0% +important you have to be very careful + + + align:start position:0% +important you have to be very careful +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yes + + align:start position:0% + + + + align:start position:0% + +now here is not the no here you cannot + + align:start position:0% +now here is not the no here you cannot + + + align:start position:0% +now here is not the no here you cannot +do extreme stationary phase because if + + align:start position:0% +do extreme stationary phase because if + + + align:start position:0% +do extreme stationary phase because if +you just yeah yeah yeah you really need + + align:start position:0% +you just yeah yeah yeah you really need + + + align:start position:0% +you just yeah yeah yeah you really need +to suppress the other contribution + + align:start position:0% + + + + align:start position:0% + +not only suppress them you just they + + align:start position:0% +not only suppress them you just they + + + align:start position:0% +not only suppress them you just they +have to go to zero yeah + + align:start position:0% + + + + align:start position:0% + +generally go to zero okay so similarly + + align:start position:0% +generally go to zero okay so similarly + + + align:start position:0% +generally go to zero okay so similarly +with the same trick just the same scene + + align:start position:0% +with the same trick just the same scene + + + align:start position:0% +with the same trick just the same scene +in one shot + + align:start position:0% +in one shot + + + align:start position:0% +in one shot +okay selects n equal to zero + + align:start position:0% +okay selects n equal to zero + + + align:start position:0% +okay selects n equal to zero +but you see actually also selects m + + align:start position:0% +but you see actually also selects m + + + align:start position:0% +but you see actually also selects m +equal to zero + + align:start position:0% +equal to zero + + + align:start position:0% +equal to zero +because you see with the same sign + + align:start position:0% +because you see with the same sign + + + align:start position:0% +because you see with the same sign +okay with the same sign + + align:start position:0% +okay with the same sign + + + align:start position:0% +okay with the same sign +you can easily check yourself + + align:start position:0% +you can easily check yourself + + + align:start position:0% +you can easily check yourself +when T goes to plus infinity + + align:start position:0% + + + + align:start position:0% + +so these now become + + align:start position:0% +so these now become + + + align:start position:0% +so these now become +limit + + align:start position:0% +limit + + + align:start position:0% +limit +to equal to plus infinity + + align:start position:0% +to equal to plus infinity + + + align:start position:0% +to equal to plus infinity +so exponential minus i e m + + align:start position:0% +so exponential minus i e m + + + align:start position:0% +so exponential minus i e m +one minus Epsilon t + + align:start position:0% +one minus Epsilon t + + + align:start position:0% +one minus Epsilon t +times x n + + align:start position:0% +times x n + + + align:start position:0% +times x n +and then again this become + + align:start position:0% + + + + align:start position:0% + +zero for m not equal for m not equal to + + align:start position:0% +zero for m not equal for m not equal to + + + align:start position:0% +zero for m not equal for m not equal to +for n no m not equal to zero and then + + align:start position:0% +for n no m not equal to zero and then + + + align:start position:0% +for n no m not equal to zero and then +then the ground state + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so so this simple trick + + align:start position:0% +so so this simple trick + + + align:start position:0% +so so this simple trick +beautifully + + align:start position:0% +beautifully + + + align:start position:0% +beautifully +select + + align:start position:0% +select + + + align:start position:0% +select +the uh the m equal to zero and N equal + + align:start position:0% +the uh the m equal to zero and N equal + + + align:start position:0% +the uh the m equal to zero and N equal +to zero piece okay so now we can write + + align:start position:0% +to zero piece okay so now we can write + + + align:start position:0% +to zero piece okay so now we can write +so now we can write + + align:start position:0% +so now we can write + + + align:start position:0% +so now we can write +so so this is just the ground state wave + + align:start position:0% +so so this is just the ground state wave + + + align:start position:0% +so so this is just the ground state wave +function + + align:start position:0% +function + + + align:start position:0% +function +and this is just a ground state wave + + align:start position:0% +and this is just a ground state wave + + + align:start position:0% +and this is just a ground state wave +function okay so now we have + + align:start position:0% +function okay so now we have + + + align:start position:0% +function okay so now we have +limit + + align:start position:0% +limit + + + align:start position:0% +limit +T Prime go to minus infinity and T + + align:start position:0% +T Prime go to minus infinity and T + + + align:start position:0% +T Prime go to minus infinity and T +equals to plus infinity + + align:start position:0% + + + + align:start position:0% + +x t x + + align:start position:0% +x t x + + + align:start position:0% +x t x +Prime T Prime + + align:start position:0% +Prime T Prime + + + align:start position:0% +Prime T Prime +so not equal to so you have the ground + + align:start position:0% +so not equal to so you have the ground + + + align:start position:0% +so not equal to so you have the ground +state wave function star X + + align:start position:0% +state wave function star X + + + align:start position:0% +state wave function star X +um Prime + + align:start position:0% + + + + align:start position:0% + +X + + align:start position:0% +X + + + align:start position:0% +X +now 0 x + + align:start position:0% +now 0 x + + + align:start position:0% +now 0 x +0 and then you have this phase Factor + + align:start position:0% + + + + align:start position:0% + +and with everything else goes to zero + + align:start position:0% +and with everything else goes to zero + + + align:start position:0% +and with everything else goes to zero +okay + + align:start position:0% + + + + align:start position:0% + +so to look at that + + align:start position:0% +so to look at that + + + align:start position:0% +so to look at that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and so this is the so now up to those + + align:start position:0% +and so this is the so now up to those + + + align:start position:0% +and so this is the so now up to those +factors + + align:start position:0% +factors + + + align:start position:0% +factors +after those factors we get what we want + + align:start position:0% +after those factors we get what we want + + + align:start position:0% +after those factors we get what we want +okay we get what we want + + align:start position:0% + + + + align:start position:0% + +so but still you have another low in + + align:start position:0% +so but still you have another low in + + + align:start position:0% +so but still you have another low in +factors + + align:start position:0% +factors + + + align:start position:0% +factors +but they can be easily got off + + align:start position:0% +but they can be easily got off + + + align:start position:0% +but they can be easily got off +they can be easy they get rid of us + + align:start position:0% +they can be easy they get rid of us + + + align:start position:0% +they can be easy they get rid of us +using the following + + align:start position:0% + + + + align:start position:0% + +so now you also similarly + + align:start position:0% +so now you also similarly + + + align:start position:0% +so now you also similarly +the same + + align:start position:0% +the same + + + align:start position:0% +the same +exactly the same reasoning whether you + + align:start position:0% +exactly the same reasoning whether you + + + align:start position:0% +exactly the same reasoning whether you +so in this discussion whether you have X + + align:start position:0% +so in this discussion whether you have X + + + align:start position:0% +so in this discussion whether you have X +there or what's the form of X doesn't + + align:start position:0% +there or what's the form of X doesn't + + + align:start position:0% +there or what's the form of X doesn't +matter okay X can be anything + + align:start position:0% +matter okay X can be anything + + + align:start position:0% +matter okay X can be anything +so X can be anything so so + + align:start position:0% +so X can be anything so so + + + align:start position:0% +so X can be anything so so +so you can just take x equal to 1 okay + + align:start position:0% +so you can just take x equal to 1 okay + + + align:start position:0% +so you can just take x equal to 1 okay +and then you also have + + align:start position:0% +and then you also have + + + align:start position:0% +and then you also have +limit T goes to plus infinity + + align:start position:0% +limit T goes to plus infinity + + + align:start position:0% +limit T goes to plus infinity +T Prime goes to minus infinity + + align:start position:0% +T Prime goes to minus infinity + + + align:start position:0% +T Prime goes to minus infinity +the x t + + align:start position:0% +the x t + + + align:start position:0% +the x t +X Prime T Prime + + align:start position:0% +X Prime T Prime + + + align:start position:0% +X Prime T Prime +so this is also equal to psi 0 x sine + + align:start position:0% +so this is also equal to psi 0 x sine + + + align:start position:0% +so this is also equal to psi 0 x sine +zero star + + align:start position:0% +zero star + + + align:start position:0% +zero star +X Prime + + align:start position:0% +X Prime + + + align:start position:0% +X Prime +and now is the zero with zero okay + + align:start position:0% +and now is the zero with zero okay + + + align:start position:0% +and now is the zero with zero okay +because the uh if set x equal to 1 okay + + align:start position:0% +because the uh if set x equal to 1 okay + + + align:start position:0% +because the uh if set x equal to 1 okay +and then you just ground state and so so + + align:start position:0% +and then you just ground state and so so + + + align:start position:0% +and then you just ground state and so so +this is just equal to one + + align:start position:0% +this is just equal to one + + + align:start position:0% +this is just equal to one +and then you have the same factor + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so now + + align:start position:0% + + + + align:start position:0% + +now we can just find the GN + + align:start position:0% +now we can just find the GN + + + align:start position:0% +now we can just find the GN +okay so this object is GN + + align:start position:0% + + + + align:start position:0% + +so GN then can be found as the ratio + + align:start position:0% +so GN then can be found as the ratio + + + align:start position:0% +so GN then can be found as the ratio +between the two + + align:start position:0% + + + + align:start position:0% + +take the limit t plus infinity T Prime + + align:start position:0% +take the limit t plus infinity T Prime + + + align:start position:0% +take the limit t plus infinity T Prime +go to minus infinity + + align:start position:0% + + + + align:start position:0% + +have x t + + align:start position:0% +have x t + + + align:start position:0% +have x t +X Prime T Prime + + align:start position:0% +X Prime T Prime + + + align:start position:0% +X Prime T Prime +and x t + + align:start position:0% +and x t + + + align:start position:0% +and x t +and x x t + + align:start position:0% +and x x t + + + align:start position:0% +and x x t +okay you can just find that as a ratio + + align:start position:0% +okay you can just find that as a ratio + + + align:start position:0% +okay you can just find that as a ratio +between the two + + align:start position:0% +between the two + + + align:start position:0% +between the two +so this gives you the expression + + align:start position:0% +so this gives you the expression + + + align:start position:0% +so this gives you the expression +for calculating this cooling function + + align:start position:0% +for calculating this cooling function + + + align:start position:0% +for calculating this cooling function +okay uh this correlation function + + align:start position:0% +okay uh this correlation function + + + align:start position:0% +okay uh this correlation function +so in the axis any time order the + + align:start position:0% +so in the axis any time order the + + + align:start position:0% +so in the axis any time order the +product okay + + align:start position:0% + + + + align:start position:0% + +and therefore now for each of them below + + align:start position:0% +and therefore now for each of them below + + + align:start position:0% +and therefore now for each of them below +the path integral + + align:start position:0% +the path integral + + + align:start position:0% +the path integral +and then you can just write down the + + align:start position:0% +and then you can just write down the + + + align:start position:0% +and then you can just write down the +pattern and go for each other + + align:start position:0% + + + + align:start position:0% + +so now you see + + align:start position:0% +so now you see + + + align:start position:0% +so now you see +this GN is in principle or a physical + + align:start position:0% +this GN is in principle or a physical + + + align:start position:0% +this GN is in principle or a physical +observable that actually involving the + + align:start position:0% +observable that actually involving the + + + align:start position:0% +observable that actually involving the +ratio of two passing goals + + align:start position:0% +ratio of two passing goals + + + align:start position:0% +ratio of two passing goals +when without any X and Y with some x a + + align:start position:0% +when without any X and Y with some x a + + + align:start position:0% +when without any X and Y with some x a +visual desired correlation functions so + + align:start position:0% +visual desired correlation functions so + + + align:start position:0% +visual desired correlation functions so +as I mentioned before + + align:start position:0% +as I mentioned before + + + align:start position:0% +as I mentioned before +that when you evaluate the path + + align:start position:0% +that when you evaluate the path + + + align:start position:0% +that when you evaluate the path +integrals you will get that kind of C + + align:start position:0% +integrals you will get that kind of C + + + align:start position:0% +integrals you will get that kind of C +between upstairs and downstairs NATO we + + align:start position:0% +between upstairs and downstairs NATO we + + + align:start position:0% +between upstairs and downstairs NATO we +will see explicitly + + align:start position:0% +will see explicitly + + + align:start position:0% +will see explicitly +okay so yeah so this is a beautiful + + align:start position:0% +okay so yeah so this is a beautiful + + + align:start position:0% +okay so yeah so this is a beautiful +formula okay and uh and the + + align:start position:0% +formula okay and uh and the + + + align:start position:0% +formula okay and uh and the +um yeah + + align:start position:0% +um yeah + + + align:start position:0% +um yeah +and and then you don't have to + + align:start position:0% +and and then you don't have to + + + align:start position:0% +and and then you don't have to +you don't have to uh uh uh + + align:start position:0% +you don't have to uh uh uh + + + align:start position:0% +you don't have to uh uh uh +um yeah yeah so all those factors + + align:start position:0% +um yeah yeah so all those factors + + + align:start position:0% +um yeah yeah so all those factors +canceled you don't need to know the + + align:start position:0% +canceled you don't need to know the + + + align:start position:0% +canceled you don't need to know the +ground state wave function you can just + + align:start position:0% +ground state wave function you can just + + + align:start position:0% +ground state wave function you can just +perform that path in the code + + align:start position:0% +perform that path in the code + + + align:start position:0% +perform that path in the code +okay uh perform that path in the ground + + align:start position:0% +okay uh perform that path in the ground + + + align:start position:0% +okay uh perform that path in the ground +and here in principle you can also take + + align:start position:0% + + + + align:start position:0% + +arbitrary + + align:start position:0% + + + + align:start position:0% + +x and x Prime + + align:start position:0% +x and x Prime + + + align:start position:0% +x and x Prime +okay you can take aperture X and the + + align:start position:0% +okay you can take aperture X and the + + + align:start position:0% +okay you can take aperture X and the +exponent doesn't matter + + align:start position:0% +exponent doesn't matter + + + align:start position:0% +exponent doesn't matter +so conventionally we just take x equal + + align:start position:0% +so conventionally we just take x equal + + + align:start position:0% +so conventionally we just take x equal +to X Prime equal to zero + + align:start position:0% +to X Prime equal to zero + + + align:start position:0% +to X Prime equal to zero +that's for Simplicity okay + + align:start position:0% +that's for Simplicity okay + + + align:start position:0% +that's for Simplicity okay +we can just take them to zero + + align:start position:0% + + + + align:start position:0% + +okay any questions on this + + align:start position:0% +okay any questions on this + + + align:start position:0% +okay any questions on this +yes + + align:start position:0% + + + + align:start position:0% + +yeah I just the only thing matters is + + align:start position:0% +yeah I just the only thing matters is + + + align:start position:0% +yeah I just the only thing matters is +there + + align:start position:0% +there + + + align:start position:0% +there +so they only come into this + + align:start position:0% +so they only come into this + + + align:start position:0% +so they only come into this +pre-factor and then cancel the between + + align:start position:0% +pre-factor and then cancel the between + + + align:start position:0% +pre-factor and then cancel the between +the two it doesn't matter + + align:start position:0% +the two it doesn't matter + + + align:start position:0% +the two it doesn't matter +yeah so yeah all the uh the factors + + align:start position:0% +yeah so yeah all the uh the factors + + + align:start position:0% +yeah so yeah all the uh the factors +there and this Factor they just cancel + + align:start position:0% +there and this Factor they just cancel + + + align:start position:0% +there and this Factor they just cancel +and you just have to be this + + align:start position:0% +and you just have to be this + + + align:start position:0% +and you just have to be this +x0 left so so it doesn't matter they + + align:start position:0% +x0 left so so it doesn't matter they + + + align:start position:0% +x0 left so so it doesn't matter they +cancel anyway so it doesn't matter where + + align:start position:0% +cancel anyway so it doesn't matter where + + + align:start position:0% +cancel anyway so it doesn't matter where +you put x and x Prime + + align:start position:0% +you put x and x Prime + + + align:start position:0% +you put x and x Prime +yes + + align:start position:0% + + + + align:start position:0% + +so so normally when you calculate that + + align:start position:0% +so so normally when you calculate that + + + align:start position:0% +so so normally when you calculate that +at the end and then you take Epsilon + + align:start position:0% +at the end and then you take Epsilon + + + align:start position:0% +at the end and then you take Epsilon +goes to zero yeah so we just normally + + align:start position:0% +goes to zero yeah so we just normally + + + align:start position:0% +goes to zero yeah so we just normally +believe that it implicit + + align:start position:0% +believe that it implicit + + + align:start position:0% +believe that it implicit +yeah when you do the path integral you + + align:start position:0% +yeah when you do the path integral you + + + align:start position:0% +yeah when you do the path integral you +keep a small Epsilon + + align:start position:0% +keep a small Epsilon + + + align:start position:0% +keep a small Epsilon +and so after you finish doing the + + align:start position:0% +and so after you finish doing the + + + align:start position:0% +and so after you finish doing the +passing after you finish in the end you + + align:start position:0% +passing after you finish in the end you + + + align:start position:0% +passing after you finish in the end you +take the absolute zero + + align:start position:0% +take the absolute zero + + + align:start position:0% +take the absolute zero +yes + + align:start position:0% +yes + + + align:start position:0% +yes +I'm sorry also on why we can take x and + + align:start position:0% +I'm sorry also on why we can take x and + + + align:start position:0% +I'm sorry also on why we can take x and +x Prime equals + + align:start position:0% +x Prime equals + + + align:start position:0% +x Prime equals +like the balance depend on X and X Prime + + align:start position:0% +like the balance depend on X and X Prime + + + align:start position:0% +like the balance depend on X and X Prime +now the bounds does not depend on it's + + align:start position:0% +now the bounds does not depend on it's + + + align:start position:0% +now the bounds does not depend on it's +only the the particle is only limited by + + align:start position:0% +only the the particle is only limited by + + + align:start position:0% +only the the particle is only limited by +T and T T Prime t + + align:start position:0% +T and T T Prime t + + + align:start position:0% +T and T T Prime t +yeah initial value uh they're the same + + align:start position:0% +yeah initial value uh they're the same + + + align:start position:0% +yeah initial value uh they're the same +initial + + align:start position:0% +initial + + + align:start position:0% +initial +of course specific value of this path + + align:start position:0% +of course specific value of this path + + + align:start position:0% +of course specific value of this path +integral will depend on X and X Prime + + align:start position:0% +integral will depend on X and X Prime + + + align:start position:0% +integral will depend on X and X Prime +but the console between offset and + + align:start position:0% +but the console between offset and + + + align:start position:0% +but the console between offset and +downstairs + + align:start position:0% +downstairs + + + align:start position:0% +downstairs +so so the canceled yeah and so in the + + align:start position:0% +so so the canceled yeah and so in the + + + align:start position:0% +so so the canceled yeah and so in the +end this right hand side does not depend + + align:start position:0% +end this right hand side does not depend + + + align:start position:0% +end this right hand side does not depend +on X and X Prime + + align:start position:0% + + + + align:start position:0% + +yeah also you see here + + align:start position:0% +yeah also you see here + + + align:start position:0% +yeah also you see here +if this formula makes any sense + + align:start position:0% +if this formula makes any sense + + + align:start position:0% +if this formula makes any sense +the left hand side does not depend on X + + align:start position:0% +the left hand side does not depend on X + + + align:start position:0% +the left hand side does not depend on X +and X Prime so so the right hand side + + align:start position:0% +and X Prime so so the right hand side + + + align:start position:0% +and X Prime so so the right hand side +must not depend on X X prime otherwise + + align:start position:0% +must not depend on X X prime otherwise + + + align:start position:0% +must not depend on X X prime otherwise +this formula immediately wrong + + align:start position:0% +this formula immediately wrong + + + align:start position:0% +this formula immediately wrong +yes + + align:start position:0% + + + + align:start position:0% + +that's right that's right yeah just when + + align:start position:0% +that's right that's right yeah just when + + + align:start position:0% +that's right that's right yeah just when +you do the calculation you keep a small + + align:start position:0% +you do the calculation you keep a small + + + align:start position:0% +you do the calculation you keep a small +Epsilon when you do the path integral it + + align:start position:0% +Epsilon when you do the path integral it + + + align:start position:0% +Epsilon when you do the path integral it +keeps more absolute but but when you + + align:start position:0% +keeps more absolute but but when you + + + align:start position:0% +keeps more absolute but but when you +finally calculate the value answer you + + align:start position:0% +finally calculate the value answer you + + + align:start position:0% +finally calculate the value answer you +can set Epsilon to zero + + align:start position:0% + + + + align:start position:0% + +um no you have to keep Epsilon + + align:start position:0% +um no you have to keep Epsilon + + + align:start position:0% +um no you have to keep Epsilon +this you have to take first + + align:start position:0% +this you have to take first + + + align:start position:0% +this you have to take first +so this is part of your calculation + + align:start position:0% +so this is part of your calculation + + + align:start position:0% +so this is part of your calculation +you have to always take this first + + align:start position:0% +you have to always take this first + + + align:start position:0% +you have to always take this first +and the big because the final answer + + align:start position:0% +and the big because the final answer + + + align:start position:0% +and the big because the final answer +also does not depend on T and T Prime + + align:start position:0% +also does not depend on T and T Prime + + + align:start position:0% +also does not depend on T and T Prime +and because this is the vacuum uh this + + align:start position:0% +and because this is the vacuum uh this + + + align:start position:0% +and because this is the vacuum uh this +correlation function does not depend on + + align:start position:0% +correlation function does not depend on + + + align:start position:0% +correlation function does not depend on +your T and T Prime so so you uh you + + align:start position:0% +your T and T Prime so so you uh you + + + align:start position:0% +your T and T Prime so so you uh you +always + + align:start position:0% +always + + + align:start position:0% +always +set the uh yeah you keep a small Epsilon + + align:start position:0% +set the uh yeah you keep a small Epsilon + + + align:start position:0% +set the uh yeah you keep a small Epsilon +take this limit first and do the + + align:start position:0% +take this limit first and do the + + + align:start position:0% +take this limit first and do the +calculation + + align:start position:0% +calculation + + + align:start position:0% +calculation +do the calculation and then when you + + align:start position:0% +do the calculation and then when you + + + align:start position:0% +do the calculation and then when you +calculate everything at the end of the + + align:start position:0% +calculate everything at the end of the + + + align:start position:0% +calculate everything at the end of the +day then you set Epsilon to zero + + align:start position:0% +day then you set Epsilon to zero + + + align:start position:0% +day then you set Epsilon to zero +and then that guarantee you choose the + + align:start position:0% +and then that guarantee you choose the + + + align:start position:0% +and then that guarantee you choose the +vacuum + + align:start position:0% + + + + align:start position:0% + +go to this + + align:start position:0% +go to this + + + align:start position:0% +go to this +this of + + align:start position:0% +this of + + + align:start position:0% +this of +one more + + align:start position:0% +one more + + + align:start position:0% +one more +uh a trick we have to do okay sorry it + + align:start position:0% +uh a trick we have to do okay sorry it + + + align:start position:0% +uh a trick we have to do okay sorry it +had too many tricks there's one more + + align:start position:0% +had too many tricks there's one more + + + align:start position:0% +had too many tricks there's one more +trick we have to do + + align:start position:0% +trick we have to do + + + align:start position:0% +trick we have to do +um + + align:start position:0% +um + + + align:start position:0% +um +so so now we have told you how to + + align:start position:0% +so so now we have told you how to + + + align:start position:0% +so so now we have told you how to +calculate this guy for arbitrary X + + align:start position:0% +calculate this guy for arbitrary X + + + align:start position:0% +calculate this guy for arbitrary X +but often it's actually + + align:start position:0% + + + + align:start position:0% + +it's actually uh not + + align:start position:0% +it's actually uh not + + + align:start position:0% +it's actually uh not +it's not the smartest way + + align:start position:0% +it's not the smartest way + + + align:start position:0% +it's not the smartest way +to directly calculate such a endpoint + + align:start position:0% +to directly calculate such a endpoint + + + align:start position:0% +to directly calculate such a endpoint +function okay + + align:start position:0% +function okay + + + align:start position:0% +function okay +it's also not the smartest way + + align:start position:0% +it's also not the smartest way + + + align:start position:0% +it's also not the smartest way +so so there's something a little bit + + align:start position:0% +so so there's something a little bit + + + align:start position:0% +so so there's something a little bit +uh more + + align:start position:0% +uh more + + + align:start position:0% +uh more +uh uh more clever it's called generating + + align:start position:0% +uh uh more clever it's called generating + + + align:start position:0% +uh uh more clever it's called generating +functional + + align:start position:0% + + + + align:start position:0% + +so some of you may have seen this + + align:start position:0% +so some of you may have seen this + + + align:start position:0% +so some of you may have seen this +say in your high school math competition + + align:start position:0% +say in your high school math competition + + + align:start position:0% +say in your high school math competition +um + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +so suppose we wanted to integral like + + align:start position:0% +so suppose we wanted to integral like + + + align:start position:0% +so suppose we wanted to integral like +this okay + + align:start position:0% +this okay + + + align:start position:0% +this okay +so let's do again let's go back to + + align:start position:0% +so let's do again let's go back to + + + align:start position:0% +so let's do again let's go back to +ordinary integral + + align:start position:0% +ordinary integral + + + align:start position:0% +ordinary integral +so let's just I suppose we wanted to + + align:start position:0% +so let's just I suppose we wanted to + + + align:start position:0% +so let's just I suppose we wanted to +integral like this so so you have a + + align:start position:0% +integral like this so so you have a + + + align:start position:0% +integral like this so so you have a +parallel let's just say + + align:start position:0% +parallel let's just say + + + align:start position:0% +parallel let's just say +this we have some face like what you do + + align:start position:0% +this we have some face like what you do + + + align:start position:0% +this we have some face like what you do +in the past integral and we want to + + align:start position:0% +in the past integral and we want to + + + align:start position:0% +in the past integral and we want to +calculate x to the power n + + align:start position:0% +calculate x to the power n + + + align:start position:0% +calculate x to the power n +okay I need some integer + + align:start position:0% +okay I need some integer + + + align:start position:0% +okay I need some integer +uh here yeah here like you have endpoint + + align:start position:0% +uh here yeah here like you have endpoint + + + align:start position:0% +uh here yeah here like you have endpoint +function yeah yeah suppose we want to + + align:start position:0% +function yeah yeah suppose we want to + + + align:start position:0% +function yeah yeah suppose we want to +calculate this + + align:start position:0% +calculate this + + + align:start position:0% +calculate this +so you can just calculate this guy is + + align:start position:0% +so you can just calculate this guy is + + + align:start position:0% +so you can just calculate this guy is +fine okay but but there's a better way + + align:start position:0% +fine okay but but there's a better way + + + align:start position:0% +fine okay but but there's a better way +uh often there's a better way it is that + + align:start position:0% +uh often there's a better way it is that + + + align:start position:0% +uh often there's a better way it is that +instead of calculate this for individual + + align:start position:0% +instead of calculate this for individual + + + align:start position:0% +instead of calculate this for individual +n + + align:start position:0% +n + + + align:start position:0% +n +you can actually consider a following + + align:start position:0% +you can actually consider a following + + + align:start position:0% +you can actually consider a following +quantity + + align:start position:0% + + + + align:start position:0% + +the d a + + align:start position:0% +the d a + + + align:start position:0% +the d a +uh and which is defined to be + + align:start position:0% +uh and which is defined to be + + + align:start position:0% +uh and which is defined to be +DX + + align:start position:0% + + + + align:start position:0% + +expansion I + + align:start position:0% +expansion I + + + align:start position:0% +expansion I +Lambda f x + + align:start position:0% +Lambda f x + + + align:start position:0% +Lambda f x +then plus I + + align:start position:0% +then plus I + + + align:start position:0% +then plus I +say ax + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so you can see that this object + + align:start position:0% + + + + align:start position:0% + +so this object when you expand this + + align:start position:0% +so this object when you expand this + + + align:start position:0% +so this object when you expand this +exponential + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +I think I don't need this anymore + + align:start position:0% + + + + align:start position:0% + +yeah let me just erase this + + align:start position:0% + + + + align:start position:0% + +so now if you so why we are interested + + align:start position:0% +so now if you so why we are interested + + + align:start position:0% +so now if you so why we are interested +in this object + + align:start position:0% +in this object + + + align:start position:0% +in this object +because imagine you you expanded this + + align:start position:0% +because imagine you you expanded this + + + align:start position:0% +because imagine you you expanded this +exponential Factor + + align:start position:0% +exponential Factor + + + align:start position:0% +exponential Factor +and then you + + align:start position:0% +and then you + + + align:start position:0% +and then you +essentially you get the a + + align:start position:0% +essentially you get the a + + + align:start position:0% +essentially you get the a +is exponential n equal to zero to + + align:start position:0% +is exponential n equal to zero to + + + align:start position:0% +is exponential n equal to zero to +Infinity + + align:start position:0% + + + + align:start position:0% + +and factorial + + align:start position:0% +and factorial + + + align:start position:0% +and factorial +i a n d n okay so if you expand this + + align:start position:0% +i a n d n okay so if you expand this + + + align:start position:0% +i a n d n okay so if you expand this +thing in power series of a or power + + align:start position:0% +thing in power series of a or power + + + align:start position:0% +thing in power series of a or power +Series yeah if you expand this and then + + align:start position:0% +Series yeah if you expand this and then + + + align:start position:0% +Series yeah if you expand this and then +just n's term will give you an X power n + + align:start position:0% +just n's term will give you an X power n + + + align:start position:0% +just n's term will give you an X power n +and then it's the same that we just + + align:start position:0% +and then it's the same that we just + + + align:start position:0% +and then it's the same that we just +expand + + align:start position:0% +expand + + + align:start position:0% +expand +this is the a in power series + + align:start position:0% +this is the a in power series + + + align:start position:0% +this is the a in power series +and then the M would be the end + + align:start position:0% +and then the M would be the end + + + align:start position:0% +and then the M would be the end +coefficient + + align:start position:0% +coefficient + + + align:start position:0% +coefficient +okay so so if you compute + + align:start position:0% +okay so so if you compute + + + align:start position:0% +okay so so if you compute +the a in one shot + + align:start position:0% +the a in one shot + + + align:start position:0% +the a in one shot +and then and then the the the the N you + + align:start position:0% +and then and then the the the the N you + + + align:start position:0% +and then and then the the the the N you +can just do about about Taylor series + + align:start position:0% +can just do about about Taylor series + + + align:start position:0% +can just do about about Taylor series +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so sometimes we also write the n + + align:start position:0% +so sometimes we also write the n + + + align:start position:0% +so sometimes we also write the n +as say I to the power n + + align:start position:0% +as say I to the power n + + + align:start position:0% +as say I to the power n +then you take n derivative of the a + + align:start position:0% +then you take n derivative of the a + + + align:start position:0% +then you take n derivative of the a +over a + + align:start position:0% +over a + + + align:start position:0% +over a +and then you set a equal to zero okay + + align:start position:0% +and then you set a equal to zero okay + + + align:start position:0% +and then you set a equal to zero okay +so this is the same thing + + align:start position:0% +so this is the same thing + + + align:start position:0% +so this is the same thing +so when you set Take N derivatives + + align:start position:0% +so when you set Take N derivatives + + + align:start position:0% +so when you set Take N derivatives +of a + + align:start position:0% +of a + + + align:start position:0% +of a +you get rid of the earlier the lower + + align:start position:0% +you get rid of the earlier the lower + + + align:start position:0% +you get rid of the earlier the lower +powers + + align:start position:0% +powers + + + align:start position:0% +powers +and then the higher Powers you get rid + + align:start position:0% +and then the higher Powers you get rid + + + align:start position:0% +and then the higher Powers you get rid +of by setting a equal to zero + + align:start position:0% +of by setting a equal to zero + + + align:start position:0% +of by setting a equal to zero +okay so then that's just pick this term + + align:start position:0% +okay so then that's just pick this term + + + align:start position:0% +okay so then that's just pick this term +okay pick the end + + align:start position:0% + + + + align:start position:0% + +so so this is so d a is called the + + align:start position:0% +so so this is so d a is called the + + + align:start position:0% +so so this is so d a is called the +generating function + + align:start position:0% + + + + align:start position:0% + +okay a generating function + + align:start position:0% + + + + align:start position:0% + +oh okay so now when we want to so one + + align:start position:0% +oh okay so now when we want to so one + + + align:start position:0% +oh okay so now when we want to so one +final remark + + align:start position:0% +final remark + + + align:start position:0% +final remark +so now we want to compute this guy + + align:start position:0% + + + + align:start position:0% + +so this GN + + align:start position:0% + + + + align:start position:0% + +is equal to t x 1 say x n + + align:start position:0% +is equal to t x 1 say x n + + + align:start position:0% +is equal to t x 1 say x n +so xc1 x t n + + align:start position:0% + + + + align:start position:0% + +again instead of computing each one of + + align:start position:0% +again instead of computing each one of + + + align:start position:0% +again instead of computing each one of +them + + align:start position:0% +them + + + align:start position:0% +them +we can consider such a so-called + + align:start position:0% +we can consider such a so-called + + + align:start position:0% +we can consider such a so-called +generating function of generation of + + align:start position:0% +generating function of generation of + + + align:start position:0% +generating function of generation of +this idea we can consider Z + + align:start position:0% + + + + align:start position:0% + +JT + + align:start position:0% + + + + align:start position:0% + +you can consider this object dxt + + align:start position:0% + + + + align:start position:0% + +and now add I + + align:start position:0% +and now add I + + + align:start position:0% +and now add I +DT + + align:start position:0% +DT + + + align:start position:0% +DT +so minus infinity to plus infinity JT + + align:start position:0% +so minus infinity to plus infinity JT + + + align:start position:0% +so minus infinity to plus infinity JT +x t + + align:start position:0% +x t + + + align:start position:0% +x t +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so remember this is just the path + + align:start position:0% +so remember this is just the path + + + align:start position:0% +so remember this is just the path +integral + + align:start position:0% +integral + + + align:start position:0% +integral +so let's just look at the upstairs okay + + align:start position:0% +so let's just look at the upstairs okay + + + align:start position:0% +so let's just look at the upstairs okay +uh uh + + align:start position:0% +uh uh + + + align:start position:0% +uh uh +expansion I X + + align:start position:0% +expansion I X + + + align:start position:0% +expansion I X +commission is + + align:start position:0% +commission is + + + align:start position:0% +commission is +x t + + align:start position:0% + + + + align:start position:0% + +so now this does the same thing so now + + align:start position:0% +so now this does the same thing so now + + + align:start position:0% +so now this does the same thing so now +if you take this imagine you expand this + + align:start position:0% +if you take this imagine you expand this + + + align:start position:0% +if you take this imagine you expand this +Factor + + align:start position:0% +Factor + + + align:start position:0% +Factor +okay and then + + align:start position:0% +okay and then + + + align:start position:0% +okay and then +to ends power then you will generate + + align:start position:0% +to ends power then you will generate + + + align:start position:0% +to ends power then you will generate +this term as a coefficient okay we will + + align:start position:0% +this term as a coefficient okay we will + + + align:start position:0% +this term as a coefficient okay we will +discuss that in more detail next time + + align:start position:0% +discuss that in more detail next time + + + align:start position:0% +discuss that in more detail next time +okay so so so so so often instead of + + align:start position:0% +okay so so so so so often instead of + + + align:start position:0% +okay so so so so so often instead of +computing + + align:start position:0% +computing + + + align:start position:0% +computing +this object directly + + align:start position:0% +this object directly + + + align:start position:0% +this object directly +we compute a generating functional + + align:start position:0% +we compute a generating functional + + + align:start position:0% +we compute a generating functional +so-called generating functional and then + + align:start position:0% +so-called generating functional and then + + + align:start position:0% +so-called generating functional and then +and then which often makes sense much + + align:start position:0% +and then which often makes sense much + + + align:start position:0% +and then which often makes sense much +easier + + align:start position:0% +easier + + + align:start position:0% +easier +okay I often makes things much easier + + align:start position:0% +okay I often makes things much easier + + + align:start position:0% +okay I often makes things much easier +um + + align:start position:0% +um + + + align:start position:0% +um +yeah so this this preparation and then + + align:start position:0% +yeah so this this preparation and then + + + align:start position:0% +yeah so this this preparation and then +we are ready to + + align:start position:0% +we are ready to + + + align:start position:0% +we are ready to +tackle + + align:start position:0% +tackle + + + align:start position:0% +tackle +how to treat this thing + + align:start position:0% +how to treat this thing + + + align:start position:0% +how to treat this thing +in uh how to uh actually finding such + + align:start position:0% +in uh how to uh actually finding such + + + align:start position:0% +in uh how to uh actually finding such +object in quantum mechanics + + align:start position:0% +object in quantum mechanics + + + align:start position:0% +object in quantum mechanics +and once we have that doing field Theory + + align:start position:0% +and once we have that doing field Theory + + + align:start position:0% +and once we have that doing field Theory +will be automatic + + align:start position:0% +will be automatic + + + align:start position:0% +will be automatic +and then then you will + + align:start position:0% +and then then you will + + + align:start position:0% +and then then you will +then know how to actually calculate the + + align:start position:0% +then know how to actually calculate the + + + align:start position:0% +then know how to actually calculate the +scattering amplitude which is a good + + align:start position:0% +scattering amplitude which is a good + + + align:start position:0% +scattering amplitude which is a good +achievement yeah + + align:start position:0% +achievement yeah + + + align:start position:0% +achievement yeah +okay so so let's stop here \ No newline at end of file diff --git a/GyFVgJZ0hIs.txt b/GyFVgJZ0hIs.txt new file mode 100644 index 0000000000000000000000000000000000000000..34817f0036d3f9e8d66bd9ea3392b40b122e0d41 --- /dev/null +++ b/GyFVgJZ0hIs.txt @@ -0,0 +1,1811 @@ +align:start position:0% + +in 6042 we're going to be pretty + + align:start position:0% +in 6042 we're going to be pretty + + + align:start position:0% +in 6042 we're going to be pretty +concerned with proofs we're going to try + + align:start position:0% +concerned with proofs we're going to try + + + align:start position:0% +concerned with proofs we're going to try +to help you learn how to do rudimentary + + align:start position:0% +to help you learn how to do rudimentary + + + align:start position:0% +to help you learn how to do rudimentary +proofs uh and not be afraid of them the + + align:start position:0% +proofs uh and not be afraid of them the + + + align:start position:0% +proofs uh and not be afraid of them the +most important skill in some ways is the + + align:start position:0% +most important skill in some ways is the + + + align:start position:0% +most important skill in some ways is the +ability to distinguish a very plausible + + align:start position:0% +ability to distinguish a very plausible + + + align:start position:0% +ability to distinguish a very plausible +argument that might not be totally right + + align:start position:0% +argument that might not be totally right + + + align:start position:0% +argument that might not be totally right +from a proof which is totally right + + align:start position:0% +from a proof which is totally right + + + align:start position:0% +from a proof which is totally right +that's an important skill and it's a + + align:start position:0% +that's an important skill and it's a + + + align:start position:0% +that's an important skill and it's a +it's a basic understanding of what math + + align:start position:0% +it's a basic understanding of what math + + + align:start position:0% +it's a basic understanding of what math +is it's that distinction between knowing + + align:start position:0% +is it's that distinction between knowing + + + align:start position:0% +is it's that distinction between knowing +when a thing is mathematically + + align:start position:0% +when a thing is mathematically + + + align:start position:0% +when a thing is mathematically +absolutely uh unarguable and and uh + + align:start position:0% +absolutely uh unarguable and and uh + + + align:start position:0% +absolutely uh unarguable and and uh +inevitable as opposed to something + + align:start position:0% +inevitable as opposed to something + + + align:start position:0% +inevitable as opposed to something +that's just very likely it's interesting + + align:start position:0% +that's just very likely it's interesting + + + align:start position:0% +that's just very likely it's interesting +physicists by and large do a lot of math + + align:start position:0% +physicists by and large do a lot of math + + + align:start position:0% +physicists by and large do a lot of math +and they tend not to worry so much about + + align:start position:0% +and they tend not to worry so much about + + + align:start position:0% +and they tend not to worry so much about +proofs but all the theoreticians and the + + align:start position:0% +proofs but all the theoreticians and the + + + align:start position:0% +proofs but all the theoreticians and the +mathematicians are uh in agreement that + + align:start position:0% +mathematicians are uh in agreement that + + + align:start position:0% +mathematicians are uh in agreement that +that you don't really understand the + + align:start position:0% +that you don't really understand the + + + align:start position:0% +that you don't really understand the +subject until you know how to prove the + + align:start position:0% +subject until you know how to prove the + + + align:start position:0% +subject until you know how to prove the +basic facts pragmatically the value of + + align:start position:0% +basic facts pragmatically the value of + + + align:start position:0% +basic facts pragmatically the value of +proofs is that uh there's an awful lot + + align:start position:0% +proofs is that uh there's an awful lot + + + align:start position:0% +proofs is that uh there's an awful lot +of content in this subject and in in + + align:start position:0% +of content in this subject and in in + + + align:start position:0% +of content in this subject and in in +many other mathematical subjects and if + + align:start position:0% +many other mathematical subjects and if + + + align:start position:0% +many other mathematical subjects and if +your only way to figure out what the + + align:start position:0% +your only way to figure out what the + + + align:start position:0% +your only way to figure out what the +exact details are is memorization you're + + align:start position:0% +exact details are is memorization you're + + + align:start position:0% +exact details are is memorization you're +going to get lost most of these rules + + align:start position:0% +going to get lost most of these rules + + + align:start position:0% +going to get lost most of these rules +and and theorems that we prove I can + + align:start position:0% +and and theorems that we prove I can + + + align:start position:0% +and and theorems that we prove I can +never remember them exactly but I know + + align:start position:0% +never remember them exactly but I know + + + align:start position:0% +never remember them exactly but I know +how to prove them so I can debug them + + align:start position:0% +how to prove them so I can debug them + + + align:start position:0% +how to prove them so I can debug them +and get them exactly right so let's + + align:start position:0% +and get them exactly right so let's + + + align:start position:0% +and get them exactly right so let's +begin by looking at uh some just + + align:start position:0% +begin by looking at uh some just + + + align:start position:0% +begin by looking at uh some just +examples of proofs before we start to + + align:start position:0% +examples of proofs before we start to + + + align:start position:0% +examples of proofs before we start to +get try to get abstract about what they + + align:start position:0% +get try to get abstract about what they + + + align:start position:0% +get try to get abstract about what they +are and we'll look at um a famous + + align:start position:0% +are and we'll look at um a famous + + + align:start position:0% +are and we'll look at um a famous +theorem that you've all seen from early + + align:start position:0% +theorem that you've all seen from early + + + align:start position:0% +theorem that you've all seen from early +on in high school the Pythagorean + + align:start position:0% +on in high school the Pythagorean + + + align:start position:0% +on in high school the Pythagorean +theorem it says that if I have a right + + align:start position:0% +theorem it says that if I have a right + + + align:start position:0% +theorem it says that if I have a right +triangle with sides A and B and + + align:start position:0% +triangle with sides A and B and + + + align:start position:0% +triangle with sides A and B and +hypotenuse + + align:start position:0% +hypotenuse + + + align:start position:0% +hypotenuse +C uh then there's a relationship between + + align:start position:0% +C uh then there's a relationship between + + + align:start position:0% +C uh then there's a relationship between +the a b and c namely that A2 + B2 equal + + align:start position:0% +the a b and c namely that A2 + B2 equal + + + align:start position:0% +the a b and c namely that A2 + B2 equal +c^2 now this is as I said completely + + align:start position:0% +c^2 now this is as I said completely + + + align:start position:0% +c^2 now this is as I said completely +familiar but is it obvious well every + + align:start position:0% +familiar but is it obvious well every + + + align:start position:0% +familiar but is it obvious well every +once in a while students say it's + + align:start position:0% +once in a while students say it's + + + align:start position:0% +once in a while students say it's +obvious but what I think they really + + align:start position:0% +obvious but what I think they really + + + align:start position:0% +obvious but what I think they really +mean is that it's familiar it's not + + align:start position:0% +mean is that it's familiar it's not + + + align:start position:0% +mean is that it's familiar it's not +obvious part of the argument for the + + align:start position:0% +obvious part of the argument for the + + + align:start position:0% +obvious part of the argument for the +fact that it's not obvious is that for + + align:start position:0% +fact that it's not obvious is that for + + + align:start position:0% +fact that it's not obvious is that for +thousands of years people have kept + + align:start position:0% +thousands of years people have kept + + + align:start position:0% +thousands of years people have kept +feeling the need to prove it in order to + + align:start position:0% +feeling the need to prove it in order to + + + align:start position:0% +feeling the need to prove it in order to +be sure that it's true and explain why + + align:start position:0% +be sure that it's true and explain why + + + align:start position:0% +be sure that it's true and explain why +it's true there's a citation in the + + align:start position:0% +it's true there's a citation in the + + + align:start position:0% +it's true there's a citation in the +notes of a a website devoted to + + align:start position:0% +notes of a a website devoted to + + + align:start position:0% +notes of a a website devoted to +collecting Pythagorean theorem proofs + + align:start position:0% +collecting Pythagorean theorem proofs + + + align:start position:0% +collecting Pythagorean theorem proofs +there was over a hundred of them + + align:start position:0% +there was over a hundred of them + + + align:start position:0% +there was over a hundred of them +including one by a former president of + + align:start position:0% +including one by a former president of + + + align:start position:0% +including one by a former president of +the United States um so let's look at + + align:start position:0% +the United States um so let's look at + + + align:start position:0% +the United States um so let's look at +one of my favorite proofs of the + + align:start position:0% +one of my favorite proofs of the + + + align:start position:0% +one of my favorite proofs of the +Pythagorean theorem and it goes this way + + align:start position:0% +Pythagorean theorem and it goes this way + + + align:start position:0% +Pythagorean theorem and it goes this way +um there are four triangles that are all + + align:start position:0% +um there are four triangles that are all + + + align:start position:0% +um there are four triangles that are all +the same size four copies of this ABC + + align:start position:0% +the same size four copies of this ABC + + + align:start position:0% +the same size four copies of this ABC +triangle which we've put in different + + align:start position:0% +triangle which we've put in different + + + align:start position:0% +triangle which we've put in different +colors to distinguish them and a square + + align:start position:0% +colors to distinguish them and a square + + + align:start position:0% +colors to distinguish them and a square +uh which for the moment is of unknown + + align:start position:0% +uh which for the moment is of unknown + + + align:start position:0% +uh which for the moment is of unknown +size uh and the proof of the Pythagorean + + align:start position:0% +size uh and the proof of the Pythagorean + + + align:start position:0% +size uh and the proof of the Pythagorean +theorem is going to consist of taking + + align:start position:0% +theorem is going to consist of taking + + + align:start position:0% +theorem is going to consist of taking +these four shapes and reassembling them + + align:start position:0% +these four shapes and reassembling them + + + align:start position:0% +these four shapes and reassembling them +so that they form a c by C + + align:start position:0% +so that they form a c by C + + + align:start position:0% +so that they form a c by C +Square first and then finding a second + + align:start position:0% +Square first and then finding a second + + + align:start position:0% +Square first and then finding a second +Arrangement so that they form two + + align:start position:0% +Arrangement so that they form two + + + align:start position:0% +Arrangement so that they form two +squares and a a by a square and a b by b + + align:start position:0% +squares and a a by a square and a b by b + + + align:start position:0% +squares and a a by a square and a b by b +square then by the theorem of + + align:start position:0% +square then by the theorem of + + + align:start position:0% +square then by the theorem of +conservation of paper or conservation of + + align:start position:0% +conservation of paper or conservation of + + + align:start position:0% +conservation of paper or conservation of +area uh it has to be that the uh the C + + align:start position:0% +area uh it has to be that the uh the C + + + align:start position:0% +area uh it has to be that the uh the C +by C uh area is the same as the a by a + + align:start position:0% +by C uh area is the same as the a by a + + + align:start position:0% +by C uh area is the same as the a by a +plus b by B area and so a^2 + B2 is + + align:start position:0% +plus b by B area and so a^2 + B2 is + + + align:start position:0% +plus b by B area and so a^2 + B2 is +equal to c^2 well let's look at those + + align:start position:0% +equal to c^2 well let's look at those + + + align:start position:0% +equal to c^2 well let's look at those +rearrangements and probably you should + + align:start position:0% +rearrangements and probably you should + + + align:start position:0% +rearrangements and probably you should +take a moment to try it yourself before + + align:start position:0% +take a moment to try it yourself before + + + align:start position:0% +take a moment to try it yourself before +I pop the solution up but there's the + + align:start position:0% +I pop the solution up but there's the + + + align:start position:0% +I pop the solution up but there's the +solution to the first one it's the + + align:start position:0% +solution to the first one it's the + + + align:start position:0% +solution to the first one it's the +easier of the two this is the c C + + align:start position:0% +easier of the two this is the c C + + + align:start position:0% +easier of the two this is the c C +Arrangement the hint is that if it's + + align:start position:0% +Arrangement the hint is that if it's + + + align:start position:0% +Arrangement the hint is that if it's +going to be C by C you don't have a lot + + align:start position:0% +going to be C by C you don't have a lot + + + align:start position:0% +going to be C by C you don't have a lot +of choice except to put the c c long + + align:start position:0% +of choice except to put the c c long + + + align:start position:0% +of choice except to put the c c long +hypo hypotenuses on the outside and then + + align:start position:0% +hypo hypotenuses on the outside and then + + + align:start position:0% +hypo hypotenuses on the outside and then +it's a matter of just fiddling the the + + align:start position:0% +it's a matter of just fiddling the the + + + align:start position:0% +it's a matter of just fiddling the the +the Triangles around so they fit + + align:start position:0% +the Triangles around so they fit + + + align:start position:0% +the Triangles around so they fit +together and you discover there's a + + align:start position:0% +together and you discover there's a + + + align:start position:0% +together and you discover there's a +square in the middle and that's just + + align:start position:0% +square in the middle and that's just + + + align:start position:0% +square in the middle and that's just +where that extra square that is provided + + align:start position:0% +where that extra square that is provided + + + align:start position:0% +where that extra square that is provided +will fit also this enables you to figure + + align:start position:0% +will fit also this enables you to figure + + + align:start position:0% +will fit also this enables you to figure +out the dimensions of the square are + + align:start position:0% +out the dimensions of the square are + + + align:start position:0% +out the dimensions of the square are +because if you look at it this is a b + + align:start position:0% +because if you look at it this is a b + + + align:start position:0% +because if you look at it this is a b +side we're letting B be the longer of + + align:start position:0% +side we're letting B be the longer of + + + align:start position:0% +side we're letting B be the longer of +the two sides of the triangle + + align:start position:0% +the two sides of the triangle + + + align:start position:0% +the two sides of the triangle +and this is the a side the shorter side + + align:start position:0% +and this is the a side the shorter side + + + align:start position:0% +and this is the a side the shorter side +of another triangle so what's left here + + align:start position:0% +of another triangle so what's left here + + + align:start position:0% +of another triangle so what's left here +has to be B minus a so now we know that + + align:start position:0% +has to be B minus a so now we know that + + + align:start position:0% +has to be B minus a so now we know that +it's a B minus a by B minus a squ from + + align:start position:0% +it's a B minus a by B minus a squ from + + + align:start position:0% +it's a B minus a by B minus a squ from +this + + align:start position:0% +this + + + align:start position:0% +this +Arrangement um and that's what we've uh + + align:start position:0% +Arrangement um and that's what we've uh + + + align:start position:0% +Arrangement um and that's what we've uh +indicated here now the next Arrangement + + align:start position:0% +indicated here now the next Arrangement + + + align:start position:0% +indicated here now the next Arrangement +is the following uh we're going to take + + align:start position:0% +is the following uh we're going to take + + + align:start position:0% +is the following uh we're going to take +the two the two of the triangles and + + align:start position:0% +the two the two of the triangles and + + + align:start position:0% +the two the two of the triangles and +form a rectangle and another two + + align:start position:0% +form a rectangle and another two + + + align:start position:0% +form a rectangle and another two +triangles form a rectangle line them up + + align:start position:0% +triangles form a rectangle line them up + + + align:start position:0% +triangles form a rectangle line them up +in this way and fit the B minus a by B + + align:start position:0% +in this way and fit the B minus a by B + + + align:start position:0% +in this way and fit the B minus a by B +minus a squ Square there now where are + + align:start position:0% +minus a squ Square there now where are + + + align:start position:0% +minus a squ Square there now where are +the two squares well I didn't say that + + align:start position:0% +the two squares well I didn't say that + + + align:start position:0% +the two squares well I didn't say that +the A by A and B by B squ needed to be + + align:start position:0% +the A by A and B by B squ needed to be + + + align:start position:0% +the A by A and B by B squ needed to be +separate in fact they're not there're + + align:start position:0% +separate in fact they're not there're + + + align:start position:0% +separate in fact they're not there're +attached but where are they well let's + + align:start position:0% +attached but where are they well let's + + + align:start position:0% +attached but where are they well let's +look at this uh line how long is it well + + align:start position:0% +look at this uh line how long is it well + + + align:start position:0% +look at this uh line how long is it well +it's a plus B minus a long which means + + align:start position:0% +it's a plus B minus a long which means + + + align:start position:0% +it's a plus B minus a long which means +that it's B long and suddenly there's a + + align:start position:0% +that it's B long and suddenly there's a + + + align:start position:0% +that it's B long and suddenly there's a +b and there's a b and I've got a B by + + align:start position:0% +b and there's a b and I've got a B by + + + align:start position:0% +b and there's a b and I've got a B by +B rectangle right there but wait a + + align:start position:0% +B rectangle right there but wait a + + + align:start position:0% +B rectangle right there but wait a +second here's a B minus a and it's lined + + align:start position:0% +second here's a B minus a and it's lined + + + align:start position:0% +second here's a B minus a and it's lined +up up against a b side so if I look at + + align:start position:0% +up up against a b side so if I look at + + + align:start position:0% +up up against a b side so if I look at +what's left it's B minus B minus a it + + align:start position:0% +what's left it's B minus B minus a it + + + align:start position:0% +what's left it's B minus B minus a it +tells me that that little piece is a and + + align:start position:0% +tells me that that little piece is a and + + + align:start position:0% +tells me that that little piece is a and +so sure enough when I add this uh hidden + + align:start position:0% +so sure enough when I add this uh hidden + + + align:start position:0% +so sure enough when I add this uh hidden +Line This conceptual line to separate + + align:start position:0% +Line This conceptual line to separate + + + align:start position:0% +Line This conceptual line to separate +the two squares this part's a by a and + + align:start position:0% +the two squares this part's a by a and + + + align:start position:0% +the two squares this part's a by a and +that part's B by B and we've proved the + + align:start position:0% +that part's B by B and we've proved the + + + align:start position:0% +that part's B by B and we've proved the +Pythagorean + + align:start position:0% +Pythagorean + + + align:start position:0% +Pythagorean +theorem so what about this proof um it + + align:start position:0% +theorem so what about this proof um it + + + align:start position:0% +theorem so what about this proof um it +it's really very elegant and it's abs + + align:start position:0% +it's really very elegant and it's abs + + + align:start position:0% +it's really very elegant and it's abs +correct and I hope it's kind of + + align:start position:0% +correct and I hope it's kind of + + + align:start position:0% +correct and I hope it's kind of +convincing uh and so this is a wonderful + + align:start position:0% +convincing uh and so this is a wonderful + + + align:start position:0% +convincing uh and so this is a wonderful +case of a proof by picture that really + + align:start position:0% +case of a proof by picture that really + + + align:start position:0% +case of a proof by picture that really +works in this case but unfortunately + + align:start position:0% +works in this case but unfortunately + + + align:start position:0% +works in this case but unfortunately +proof by pictures worry mathematicians + + align:start position:0% +proof by pictures worry mathematicians + + + align:start position:0% +proof by pictures worry mathematicians +and they're legitimately worrisome uh + + align:start position:0% +and they're legitimately worrisome uh + + + align:start position:0% +and they're legitimately worrisome uh +because there's lots of hidden + + align:start position:0% +because there's lots of hidden + + + align:start position:0% +because there's lots of hidden +assumptions and and exercise that you + + align:start position:0% +assumptions and and exercise that you + + + align:start position:0% +assumptions and and exercise that you +can go through is to go back and think + + align:start position:0% +can go through is to go back and think + + + align:start position:0% +can go through is to go back and think +about all of the geometric information + + align:start position:0% +about all of the geometric information + + + align:start position:0% +about all of the geometric information +that's kind of being taken for granted + + align:start position:0% +that's kind of being taken for granted + + + align:start position:0% +that's kind of being taken for granted +in this picture like over here how did + + align:start position:0% +in this picture like over here how did + + + align:start position:0% +in this picture like over here how did +we know that that was a right angle that + + align:start position:0% +we know that that was a right angle that + + + align:start position:0% +we know that that was a right angle that +this thing was a rectangle we needed + + align:start position:0% +this thing was a rectangle we needed + + + align:start position:0% +this thing was a rectangle we needed +that to be a right angle because we were + + align:start position:0% +that to be a right angle because we were + + + align:start position:0% +that to be a right angle because we were +claiming that this was a square well how + + align:start position:0% +claiming that this was a square well how + + + align:start position:0% +claiming that this was a square well how +did we know that that was a rectangle + + align:start position:0% +did we know that that was a rectangle + + + align:start position:0% +did we know that that was a rectangle +well the answers are obvious we're using + + align:start position:0% +well the answers are obvious we're using + + + align:start position:0% +well the answers are obvious we're using +the fact that the uh that the + + align:start position:0% +the fact that the uh that the + + + align:start position:0% +the fact that the uh that the +complementary angles of a right triangle + + align:start position:0% +complementary angles of a right triangle + + + align:start position:0% +complementary angles of a right triangle +sum to 90 de because the angles of a + + align:start position:0% +sum to 90 de because the angles of a + + + align:start position:0% +sum to 90 de because the angles of a +triangle in general sum to 180 degrees + + align:start position:0% +triangle in general sum to 180 degrees + + + align:start position:0% +triangle in general sum to 180 degrees +we're using that in a bunch of other + + align:start position:0% +we're using that in a bunch of other + + + align:start position:0% +we're using that in a bunch of other +places we're Al also using the fact that + + align:start position:0% +places we're Al also using the fact that + + + align:start position:0% +places we're Al also using the fact that +this is a straight line which may or may + + align:start position:0% +this is a straight line which may or may + + + align:start position:0% +this is a straight line which may or may +not be obvious uh but it's true and + + align:start position:0% +not be obvious uh but it's true and + + + align:start position:0% +not be obvious uh but it's true and +that's why it's safe to add those + + align:start position:0% +that's why it's safe to add those + + + align:start position:0% +that's why it's safe to add those +distances to figure out what it was my + + align:start position:0% +distances to figure out what it was my + + + align:start position:0% +distances to figure out what it was my +point is that there were really a whole + + align:start position:0% +point is that there were really a whole + + + align:start position:0% +point is that there were really a whole +lot of hidden assumptions in the diagram + + align:start position:0% +lot of hidden assumptions in the diagram + + + align:start position:0% +lot of hidden assumptions in the diagram +that it's easy to overlook and be fooled + + align:start position:0% +that it's easy to overlook and be fooled + + + align:start position:0% +that it's easy to overlook and be fooled +by so let me show you an example of + + align:start position:0% +by so let me show you an example of + + + align:start position:0% +by so let me show you an example of +getting fooled by a proof by diagram and + + align:start position:0% +getting fooled by a proof by diagram and + + + align:start position:0% +getting fooled by a proof by diagram and +here's how to get infinitely rich Let's + + align:start position:0% +here's how to get infinitely rich Let's + + + align:start position:0% +here's how to get infinitely rich Let's +imagine that I have a 10 by 11 piece of + + align:start position:0% +imagine that I have a 10 by 11 piece of + + + align:start position:0% +imagine that I have a 10 by 11 piece of +gold foil nice actually they could be + + align:start position:0% +gold foil nice actually they could be + + + align:start position:0% +gold foil nice actually they could be +slabs of gold but but let's think of + + align:start position:0% +slabs of gold but but let's think of + + + align:start position:0% +slabs of gold but but let's think of +this as a a rectangular shape that's + + align:start position:0% +this as a a rectangular shape that's + + + align:start position:0% +this as a a rectangular shape that's +made out of gold and it's going to be + + align:start position:0% +made out of gold and it's going to be + + + align:start position:0% +made out of gold and it's going to be +rectangles those are right angles there + + align:start position:0% +rectangles those are right angles there + + + align:start position:0% +rectangles those are right angles there +and what I'm going to do is Mark off the + + align:start position:0% +and what I'm going to do is Mark off the + + + align:start position:0% +and what I'm going to do is Mark off the +corners I'm going to uh mark off a + + align:start position:0% +corners I'm going to uh mark off a + + + align:start position:0% +corners I'm going to uh mark off a +length down of one and then I'm going to + + align:start position:0% +length down of one and then I'm going to + + + align:start position:0% +length down of one and then I'm going to +mark off a length of one so that and and + + align:start position:0% +mark off a length of one so that and and + + + align:start position:0% +mark off a length of one so that and and +shift it so that it touches the diagonal + + align:start position:0% +shift it so that it touches the diagonal + + + align:start position:0% +shift it so that it touches the diagonal +and do the same thing in this lower + + align:start position:0% +and do the same thing in this lower + + + align:start position:0% +and do the same thing in this lower +corner and now let's just shift these + + align:start position:0% +corner and now let's just shift these + + + align:start position:0% +corner and now let's just shift these +shapes um the top one going uh Southwest + + align:start position:0% +shapes um the top one going uh Southwest + + + align:start position:0% +shapes um the top one going uh Southwest +and the and the second one going + + align:start position:0% +and the and the second one going + + + align:start position:0% +and the and the second one going +Northeast and what I wind up with is + + align:start position:0% +Northeast and what I wind up with is + + + align:start position:0% +Northeast and what I wind up with is +this picture so that I've now got those + + align:start position:0% +this picture so that I've now got those + + + align:start position:0% +this picture so that I've now got those +little red triangles protruding above + + align:start position:0% +little red triangles protruding above + + + align:start position:0% +little red triangles protruding above +the shape okay cool well what are we + + align:start position:0% +the shape okay cool well what are we + + + align:start position:0% +the shape okay cool well what are we +know um this is now side 10 because I've + + align:start position:0% +know um this is now side 10 because I've + + + align:start position:0% +know um this is now side 10 because I've +subtracted one from its length here um + + align:start position:0% +subtracted one from its length here um + + + align:start position:0% +subtracted one from its length here um +and this is side 11 because that used to + + align:start position:0% +and this is side 11 because that used to + + + align:start position:0% +and this is side 11 because that used to +be 10 and I've added one to its length + + align:start position:0% +be 10 and I've added one to its length + + + align:start position:0% +be 10 and I've added one to its length +there so that's cool because now what I + + align:start position:0% +there so that's cool because now what I + + + align:start position:0% +there so that's cool because now what I +can do is take those protruding + + align:start position:0% +can do is take those protruding + + + align:start position:0% +can do is take those protruding +triangles out and they'll form a little + + align:start position:0% +triangles out and they'll form a little + + + align:start position:0% +triangles out and they'll form a little +one by one rectangle Square uh and + + align:start position:0% +one by one rectangle Square uh and + + + align:start position:0% +one by one rectangle Square uh and +suddenly I have this little bit of gold + + align:start position:0% +suddenly I have this little bit of gold + + + align:start position:0% +suddenly I have this little bit of gold +that's extra but look what's here it's a + + align:start position:0% +that's extra but look what's here it's a + + + align:start position:0% +that's extra but look what's here it's a +10 by + + align:start position:0% +10 by + + + align:start position:0% +10 by +11 rectangular shape of gold foil again + + align:start position:0% +11 rectangular shape of gold foil again + + + align:start position:0% +11 rectangular shape of gold foil again +so I just rotate this by 90° and I start + + align:start position:0% +so I just rotate this by 90° and I start + + + align:start position:0% +so I just rotate this by 90° and I start +all over again I can keep generating + + align:start position:0% +all over again I can keep generating + + + align:start position:0% +all over again I can keep generating +these little one by one shapes of gold + + align:start position:0% +these little one by one shapes of gold + + + align:start position:0% +these little one by one shapes of gold +foil forever I can get infinitely Rich + + align:start position:0% +foil forever I can get infinitely Rich + + + align:start position:0% +foil forever I can get infinitely Rich +okay well there's something wrong with + + align:start position:0% +okay well there's something wrong with + + + align:start position:0% +okay well there's something wrong with +that it's violating all kinds of confer + + align:start position:0% +that it's violating all kinds of confer + + + align:start position:0% +that it's violating all kinds of confer +conservation principles not to mention + + align:start position:0% +conservation principles not to mention + + + align:start position:0% +conservation principles not to mention +that it would undermine the price of + + align:start position:0% +that it would undermine the price of + + + align:start position:0% +that it would undermine the price of +gold so what's the bug well um if you + + align:start position:0% +gold so what's the bug well um if you + + + align:start position:0% +gold so what's the bug well um if you +probably can spot this but maybe you've + + align:start position:0% +probably can spot this but maybe you've + + + align:start position:0% +probably can spot this but maybe you've +been fooled uh what's going on is + + align:start position:0% +been fooled uh what's going on is + + + align:start position:0% +been fooled uh what's going on is +there's an implicit assumption that + + align:start position:0% +there's an implicit assumption that + + + align:start position:0% +there's an implicit assumption that +those little triangles that I cut off + + align:start position:0% +those little triangles that I cut off + + + align:start position:0% +those little triangles that I cut off +were right triangles and that this line + + align:start position:0% +were right triangles and that this line + + + align:start position:0% +were right triangles and that this line +that I claimed was of length 11 um was a + + align:start position:0% +that I claimed was of length 11 um was a + + + align:start position:0% +that I claimed was of length 11 um was a +straight line and it's not those + + align:start position:0% +straight line and it's not those + + + align:start position:0% +straight line and it's not those +triangles are a are have two sides that + + align:start position:0% +triangles are a are have two sides that + + + align:start position:0% +triangles are a are have two sides that +are of length one they're isoceles + + align:start position:0% +are of length one they're isoceles + + + align:start position:0% +are of length one they're isoceles +triangles but they're lying up against a + + align:start position:0% +triangles but they're lying up against a + + + align:start position:0% +triangles but they're lying up against a +diag diagonal that's not + + align:start position:0% +diag diagonal that's not + + + align:start position:0% +diag diagonal that's not +45° um and so they're not right + + align:start position:0% +45° um and so they're not right + + + align:start position:0% +45° um and so they're not right +triangles and that line isn't straight + + align:start position:0% +triangles and that line isn't straight + + + align:start position:0% +triangles and that line isn't straight +and 10 and 11 were close enough that it + + align:start position:0% +and 10 and 11 were close enough that it + + + align:start position:0% +and 10 and 11 were close enough that it +wasn't visually obvious so this is a way + + align:start position:0% +wasn't visually obvious so this is a way + + + align:start position:0% +wasn't visually obvious so this is a way +to Simply put one over on you with a + + align:start position:0% +to Simply put one over on you with a + + + align:start position:0% +to Simply put one over on you with a +proof by picture and if I had been asked + + align:start position:0% +proof by picture and if I had been asked + + + align:start position:0% +proof by picture and if I had been asked +to justify how do I know it's a straight + + align:start position:0% +to justify how do I know it's a straight + + + align:start position:0% +to justify how do I know it's a straight +line that bug would have emerged but + + align:start position:0% +line that bug would have emerged but + + + align:start position:0% +line that bug would have emerged but +you're not likely to notice that if it + + align:start position:0% +you're not likely to notice that if it + + + align:start position:0% +you're not likely to notice that if it +isn't visually obvious which is why we + + align:start position:0% +isn't visually obvious which is why we + + + align:start position:0% +isn't visually obvious which is why we +worry about some of these proof SP \ No newline at end of file diff --git a/HNDawwNfu5w.txt b/HNDawwNfu5w.txt new file mode 100644 index 0000000000000000000000000000000000000000..f1f408f43ba92df50a60f278ddded084531f4beb --- /dev/null +++ b/HNDawwNfu5w.txt @@ -0,0 +1,17683 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a creative common license. Your support + + align:start position:0% +a creative common license. Your support + + + align:start position:0% +a creative common license. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mit.edu. + + align:start position:0% + + + + align:start position:0% + +>> Anyway, uh today uh we have a guest + + align:start position:0% +>> Anyway, uh today uh we have a guest + + + align:start position:0% +>> Anyway, uh today uh we have a guest +speaker who's the audio director for the + + align:start position:0% +speaker who's the audio director for the + + + align:start position:0% +speaker who's the audio director for the +Singapore Academy. + + align:start position:0% +Singapore Academy. + + + align:start position:0% +Singapore Academy. +That's where we are. And um and he's + + align:start position:0% +That's where we are. And um and he's + + + align:start position:0% +That's where we are. And um and he's +going to run through brainstorming uh as + + align:start position:0% +going to run through brainstorming uh as + + + align:start position:0% +going to run through brainstorming uh as +an exercise. Um but we're not actually + + align:start position:0% +an exercise. Um but we're not actually + + + align:start position:0% +an exercise. Um but we're not actually +planning out the game that you're going + + align:start position:0% +planning out the game that you're going + + + align:start position:0% +planning out the game that you're going +to be doing for your first assignment in + + align:start position:0% +to be doing for your first assignment in + + + align:start position:0% +to be doing for your first assignment in +this class. I think this is a you're + + align:start position:0% +this class. I think this is a you're + + + align:start position:0% +this class. I think this is a you're +doing other + + align:start position:0% +doing other + + + align:start position:0% +doing other +>> Yeah, these will just be just be + + align:start position:0% +>> Yeah, these will just be just be + + + align:start position:0% +>> Yeah, these will just be just be +practice. So basically the the groups + + align:start position:0% +practice. So basically the the groups + + + align:start position:0% +practice. So basically the the groups +there will be a group activity involved + + align:start position:0% +there will be a group activity involved + + + align:start position:0% +there will be a group activity involved +in this but the the things that that + + align:start position:0% +in this but the the things that that + + + align:start position:0% +in this but the the things that that +that you're working on don't have to be + + align:start position:0% +that you're working on don't have to be + + + align:start position:0% +that you're working on don't have to be +the same groups that you will eventually + + align:start position:0% +the same groups that you will eventually + + + align:start position:0% +the same groups that you will eventually +be using for your first assignment. The + + align:start position:0% +be using for your first assignment. The + + + align:start position:0% +be using for your first assignment. The +idea is just sort of to get used to the + + align:start position:0% +idea is just sort of to get used to the + + + align:start position:0% +idea is just sort of to get used to the +process of brainstorming and sort of a + + align:start position:0% +process of brainstorming and sort of a + + + align:start position:0% +process of brainstorming and sort of a +general rules of thumb uh and before I + + align:start position:0% +general rules of thumb uh and before I + + + align:start position:0% +general rules of thumb uh and before I +spoil the entire talk. + + align:start position:0% +spoil the entire talk. + + + align:start position:0% +spoil the entire talk. +>> Yeah that's okay. So uh yeah just my + + align:start position:0% +>> Yeah that's okay. So uh yeah just my + + + align:start position:0% +>> Yeah that's okay. So uh yeah just my +name is Apstein. A little bit of + + align:start position:0% +name is Apstein. A little bit of + + + align:start position:0% +name is Apstein. A little bit of +background on myself. Um I'm the audio + + align:start position:0% +background on myself. Um I'm the audio + + + align:start position:0% +background on myself. Um I'm the audio +director here. Uh I've been working in + + align:start position:0% +director here. Uh I've been working in + + + align:start position:0% +director here. Uh I've been working in +sound design uh officially for uh a + + align:start position:0% +sound design uh officially for uh a + + + align:start position:0% +sound design uh officially for uh a +number of years now, five some odd + + align:start position:0% +number of years now, five some odd + + + align:start position:0% +number of years now, five some odd +years. Uh unofficially uh way longer + + align:start position:0% +years. Uh unofficially uh way longer + + + align:start position:0% +years. Uh unofficially uh way longer +than that. Um uh doing TV TV and video + + align:start position:0% +than that. Um uh doing TV TV and video + + + align:start position:0% +than that. Um uh doing TV TV and video +game sound design. And then uh and then + + align:start position:0% +game sound design. And then uh and then + + + align:start position:0% +game sound design. And then uh and then +before that I I was a high school + + align:start position:0% +before that I I was a high school + + + align:start position:0% +before that I I was a high school +teacher. Um and so I think you know to + + align:start position:0% +teacher. Um and so I think you know to + + + align:start position:0% +teacher. Um and so I think you know to +the extent that um uh talking about kind + + align:start position:0% +the extent that um uh talking about kind + + + align:start position:0% +the extent that um uh talking about kind +of creative collaboration uh I have a + + align:start position:0% +of creative collaboration uh I have a + + + align:start position:0% +of creative collaboration uh I have a +fair amount of experience ranging even + + align:start position:0% +fair amount of experience ranging even + + + align:start position:0% +fair amount of experience ranging even +back to to when I was uh teaching high + + align:start position:0% +back to to when I was uh teaching high + + + align:start position:0% +back to to when I was uh teaching high +school for trying to uh encourage what + + align:start position:0% +school for trying to uh encourage what + + + align:start position:0% +school for trying to uh encourage what +what we might call organized uh + + align:start position:0% +what we might call organized uh + + + align:start position:0% +what we might call organized uh +ideiation. Um I guess first I'll I'll + + align:start position:0% +ideiation. Um I guess first I'll I'll + + + align:start position:0% +ideiation. Um I guess first I'll I'll +thank you guys for for reading uh + + align:start position:0% +thank you guys for for reading uh + + + align:start position:0% +thank you guys for for reading uh +reading the text. Um it is it is funny. + + align:start position:0% +reading the text. Um it is it is funny. + + + align:start position:0% +reading the text. Um it is it is funny. +it does have these kind of um I guess + + align:start position:0% +it does have these kind of um I guess + + + align:start position:0% +it does have these kind of um I guess +now a little antiquated 1950s sort of + + align:start position:0% +now a little antiquated 1950s sort of + + + align:start position:0% +now a little antiquated 1950s sort of +references and um you know some of his + + align:start position:0% +references and um you know some of his + + + align:start position:0% +references and um you know some of his +uh some of his uh scientific evidence + + align:start position:0% +uh some of his uh scientific evidence + + + align:start position:0% +uh some of his uh scientific evidence +for uh for for why brainstorming is good + + align:start position:0% +for uh for for why brainstorming is good + + + align:start position:0% +for uh for for why brainstorming is good +is is not particularly well supported. + + align:start position:0% +is is not particularly well supported. + + + align:start position:0% +is is not particularly well supported. +was like, "We got 95 ideas." And I was + + align:start position:0% +was like, "We got 95 ideas." And I was + + + align:start position:0% +was like, "We got 95 ideas." And I was +like, "Well, how many ideas did you + + align:start position:0% +like, "Well, how many ideas did you + + + align:start position:0% +like, "Well, how many ideas did you +get?" You know, doing it the other way + + align:start position:0% +get?" You know, doing it the other way + + + align:start position:0% +get?" You know, doing it the other way +doesn't, you know, he doesn't tell you, + + align:start position:0% +doesn't, you know, he doesn't tell you, + + + align:start position:0% +doesn't, you know, he doesn't tell you, +but hey, 95, that's a big number, you + + align:start position:0% +but hey, 95, that's a big number, you + + + align:start position:0% +but hey, 95, that's a big number, you +know. So, um, you know, a little a + + align:start position:0% +know. So, um, you know, a little a + + + align:start position:0% +know. So, um, you know, a little a +little bit of background about Alex + + align:start position:0% +little bit of background about Alex + + + align:start position:0% +little bit of background about Alex +Osborne. He was, um, he was an + + align:start position:0% +Osborne. He was, um, he was an + + + align:start position:0% +Osborne. He was, um, he was an +advertising, uh, executive. Um, and so + + align:start position:0% +advertising, uh, executive. Um, and so + + + align:start position:0% +advertising, uh, executive. Um, and so +you can kind of see where brainstorming + + align:start position:0% +you can kind of see where brainstorming + + + align:start position:0% +you can kind of see where brainstorming +and advertising is a is a creative + + align:start position:0% +and advertising is a is a creative + + + align:start position:0% +and advertising is a is a creative +industry, right? It's a design industry. + + align:start position:0% +industry, right? It's a design industry. + + + align:start position:0% +industry, right? It's a design industry. +And so getting multiple people in + + align:start position:0% +And so getting multiple people in + + + align:start position:0% +And so getting multiple people in +interdisciplinary kind of you know + + align:start position:0% +interdisciplinary kind of you know + + + align:start position:0% +interdisciplinary kind of you know +different skills working together um on + + align:start position:0% +different skills working together um on + + + align:start position:0% +different skills working together um on +a on a creative project it can be a + + align:start position:0% +a on a creative project it can be a + + + align:start position:0% +a on a creative project it can be a +challenge. Um and so you can see how + + align:start position:0% +challenge. Um and so you can see how + + + align:start position:0% +challenge. Um and so you can see how +brainstorming came out of the work he + + align:start position:0% +brainstorming came out of the work he + + + align:start position:0% +brainstorming came out of the work he +was doing in advertising. So um so just + + align:start position:0% +was doing in advertising. So um so just + + + align:start position:0% +was doing in advertising. So um so just +to get started I I would say you know + + align:start position:0% +to get started I I would say you know + + + align:start position:0% +to get started I I would say you know +you've read it so you have a sense but + + align:start position:0% +you've read it so you have a sense but + + + align:start position:0% +you've read it so you have a sense but +but kind of forget what you think you + + align:start position:0% +but kind of forget what you think you + + + align:start position:0% +but kind of forget what you think you +know brainstorming is. Um some of what + + align:start position:0% +know brainstorming is. Um some of what + + + align:start position:0% +know brainstorming is. Um some of what +you think it is will apply. um some of + + align:start position:0% +you think it is will apply. um some of + + + align:start position:0% +you think it is will apply. um some of +the most fundamental principles um to + + align:start position:0% +the most fundamental principles um to + + + align:start position:0% +the most fundamental principles um to +brainstorming maybe you don't you don't + + align:start position:0% +brainstorming maybe you don't you don't + + + align:start position:0% +brainstorming maybe you don't you don't +realize or you didn't realize until you + + align:start position:0% +realize or you didn't realize until you + + + align:start position:0% +realize or you didn't realize until you +did the reading and and that's a little + + align:start position:0% +did the reading and and that's a little + + + align:start position:0% +did the reading and and that's a little +bit of what I want to talk about. I + + align:start position:0% +bit of what I want to talk about. I + + + align:start position:0% +bit of what I want to talk about. I +think the the foundation for his + + align:start position:0% +think the the foundation for his + + + align:start position:0% +think the the foundation for his +brainstorming idea is actually really + + align:start position:0% +brainstorming idea is actually really + + + align:start position:0% +brainstorming idea is actually really +solid and it's something something that + + align:start position:0% +solid and it's something something that + + + align:start position:0% +solid and it's something something that +you know we should explore today. Um + + align:start position:0% +you know we should explore today. Um + + + align:start position:0% +you know we should explore today. Um +why why brainstorming for video game + + align:start position:0% +why why brainstorming for video game + + + align:start position:0% +why why brainstorming for video game +design um is an interesting question. Um + + align:start position:0% +design um is an interesting question. Um + + + align:start position:0% +design um is an interesting question. Um +but I sort of touched on that a little + + align:start position:0% +but I sort of touched on that a little + + + align:start position:0% +but I sort of touched on that a little +bit with relation to advertising, right? + + align:start position:0% +bit with relation to advertising, right? + + + align:start position:0% +bit with relation to advertising, right? +I mean, we're talking about a creative + + align:start position:0% +I mean, we're talking about a creative + + + align:start position:0% +I mean, we're talking about a creative +industry where you've got people with + + align:start position:0% +industry where you've got people with + + + align:start position:0% +industry where you've got people with +various skill sets, whether they're + + align:start position:0% +various skill sets, whether they're + + + align:start position:0% +various skill sets, whether they're +artists or sound designers or uh game + + align:start position:0% +artists or sound designers or uh game + + + align:start position:0% +artists or sound designers or uh game +designers explicitly or producers. Um, + + align:start position:0% +designers explicitly or producers. Um, + + + align:start position:0% +designers explicitly or producers. Um, +all of these people kind of existing in + + align:start position:0% +all of these people kind of existing in + + + align:start position:0% +all of these people kind of existing in +a collaborative environment together. + + align:start position:0% +a collaborative environment together. + + + align:start position:0% +a collaborative environment together. +They're bringing different things to the + + align:start position:0% +They're bringing different things to the + + + align:start position:0% +They're bringing different things to the +table. How do you get them to to kind of + + align:start position:0% +table. How do you get them to to kind of + + + align:start position:0% +table. How do you get them to to kind of +work together and and and be + + align:start position:0% +work together and and and be + + + align:start position:0% +work together and and and be +collaboratively creative? And so this + + align:start position:0% +collaboratively creative? And so this + + + align:start position:0% +collaboratively creative? And so this +is, you know, a first step in that + + align:start position:0% +is, you know, a first step in that + + + align:start position:0% +is, you know, a first step in that +process. And so this is this is why + + align:start position:0% +process. And so this is this is why + + + align:start position:0% +process. And so this is this is why +brainstorming is particularly useful um + + align:start position:0% +brainstorming is particularly useful um + + + align:start position:0% +brainstorming is particularly useful um +for game design. And then the other + + align:start position:0% +for game design. And then the other + + + align:start position:0% +for game design. And then the other +thing um the other thing that I I think + + align:start position:0% +thing um the other thing that I I think + + + align:start position:0% +thing um the other thing that I I think +is important to understand and we'll + + align:start position:0% +is important to understand and we'll + + + align:start position:0% +is important to understand and we'll +talk about it a bit more is is um the + + align:start position:0% +talk about it a bit more is is um the + + + align:start position:0% +talk about it a bit more is is um the +kind of social pressures um that are + + align:start position:0% +kind of social pressures um that are + + + align:start position:0% +kind of social pressures um that are +created in creative envir professional + + align:start position:0% +created in creative envir professional + + + align:start position:0% +created in creative envir professional +creative environments even + + align:start position:0% +creative environments even + + + align:start position:0% +creative environments even +non-professional actually I mean it it + + align:start position:0% +non-professional actually I mean it it + + + align:start position:0% +non-professional actually I mean it it +would exist in an educational + + align:start position:0% +would exist in an educational + + + align:start position:0% +would exist in an educational +environment too um you guys are all at + + align:start position:0% +environment too um you guys are all at + + + align:start position:0% +environment too um you guys are all at +MIT it's one of the most prestigious + + align:start position:0% +MIT it's one of the most prestigious + + + align:start position:0% +MIT it's one of the most prestigious +universities um you know in the world + + align:start position:0% +universities um you know in the world + + + align:start position:0% +universities um you know in the world +right and so you're probably no stranger + + align:start position:0% +right and so you're probably no stranger + + + align:start position:0% +right and so you're probably no stranger +to the idea of of kind of social + + align:start position:0% +to the idea of of kind of social + + + align:start position:0% +to the idea of of kind of social +pressure in uh in the process of + + align:start position:0% +pressure in uh in the process of + + + align:start position:0% +pressure in uh in the process of +ideiation, right? Um you sit there and + + align:start position:0% +ideiation, right? Um you sit there and + + + align:start position:0% +ideiation, right? Um you sit there and +you say if I say this idea, am I going + + align:start position:0% +you say if I say this idea, am I going + + + align:start position:0% +you say if I say this idea, am I going +to look like an idiot? Um and and + + align:start position:0% +to look like an idiot? Um and and + + + align:start position:0% +to look like an idiot? Um and and +usually the outcome from that is if I + + align:start position:0% +usually the outcome from that is if I + + + align:start position:0% +usually the outcome from that is if I +don't say anything, it's it's you know, + + align:start position:0% +don't say anything, it's it's you know, + + + align:start position:0% +don't say anything, it's it's you know, +maybe I don't get the gain of presenting + + align:start position:0% +maybe I don't get the gain of presenting + + + align:start position:0% +maybe I don't get the gain of presenting +a good idea, but I don't get the hit of + + align:start position:0% +a good idea, but I don't get the hit of + + + align:start position:0% +a good idea, but I don't get the hit of +making a bad idea. And so it's like, you + + align:start position:0% +making a bad idea. And so it's like, you + + + align:start position:0% +making a bad idea. And so it's like, you +know, self-preservation. It's like why + + align:start position:0% +know, self-preservation. It's like why + + + align:start position:0% +know, self-preservation. It's like why +take the risk uh if if it's not worth + + align:start position:0% +take the risk uh if if it's not worth + + + align:start position:0% +take the risk uh if if it's not worth +it. Um and so you know I think MIT is an + + align:start position:0% +it. Um and so you know I think MIT is an + + + align:start position:0% +it. Um and so you know I think MIT is an +interesting place to talk about + + align:start position:0% +interesting place to talk about + + + align:start position:0% +interesting place to talk about +brainstorming and and this kind of + + align:start position:0% +brainstorming and and this kind of + + + align:start position:0% +brainstorming and and this kind of +organized ideation because there is you + + align:start position:0% +organized ideation because there is you + + + align:start position:0% +organized ideation because there is you +know social and academic pressure here + + align:start position:0% +know social and academic pressure here + + + align:start position:0% +know social and academic pressure here +too. Uh pressure to be right, pressure + + align:start position:0% +too. Uh pressure to be right, pressure + + + align:start position:0% +too. Uh pressure to be right, pressure +to not say something that would seem + + align:start position:0% +to not say something that would seem + + + align:start position:0% +to not say something that would seem +wrong and that sort of pressure is is + + align:start position:0% +wrong and that sort of pressure is is + + + align:start position:0% +wrong and that sort of pressure is is +completely uh antithetical to the idea + + align:start position:0% +completely uh antithetical to the idea + + + align:start position:0% +completely uh antithetical to the idea +of a brainstorming session. Um and so + + align:start position:0% +of a brainstorming session. Um and so + + + align:start position:0% +of a brainstorming session. Um and so +that's that's kind of a a basis for why + + align:start position:0% +that's that's kind of a a basis for why + + + align:start position:0% +that's that's kind of a a basis for why +not only it's good for video games but + + align:start position:0% +not only it's good for video games but + + + align:start position:0% +not only it's good for video games but +why it's also good to talk about talk + + align:start position:0% +why it's also good to talk about talk + + + align:start position:0% +why it's also good to talk about talk +about here at MIT. So + + align:start position:0% +about here at MIT. So + + + align:start position:0% +about here at MIT. So +there are four uh basic principles of + + align:start position:0% +there are four uh basic principles of + + + align:start position:0% +there are four uh basic principles of +brainstorming. Um you know these were + + align:start position:0% +brainstorming. Um you know these were + + + align:start position:0% +brainstorming. Um you know these were +outlined by Alex Osborne. He he was an + + align:start position:0% +outlined by Alex Osborne. He he was an + + + align:start position:0% +outlined by Alex Osborne. He he was an +ad agent. Um and uh I guess it was you + + align:start position:0% +ad agent. Um and uh I guess it was you + + + align:start position:0% +ad agent. Um and uh I guess it was you +know early he says it was like 1938 when + + align:start position:0% +know early he says it was like 1938 when + + + align:start position:0% +know early he says it was like 1938 when +he first started using it. People + + align:start position:0% +he first started using it. People + + + align:start position:0% +he first started using it. People +started kind of talking about it since + + align:start position:0% +started kind of talking about it since + + + align:start position:0% +started kind of talking about it since +then. Um and and it kind of I like when + + align:start position:0% +then. Um and and it kind of I like when + + + align:start position:0% +then. Um and and it kind of I like when +he said it sort of spiraled out of + + align:start position:0% +he said it sort of spiraled out of + + + align:start position:0% +he said it sort of spiraled out of +control that people sort of ran away + + align:start position:0% +control that people sort of ran away + + + align:start position:0% +control that people sort of ran away +with it. They're like ah this is a great + + align:start position:0% +with it. They're like ah this is a great + + + align:start position:0% +with it. They're like ah this is a great +idea but then they were they were kind + + align:start position:0% +idea but then they were they were kind + + + align:start position:0% +idea but then they were they were kind +of practicing it wrong. Um and so uh you + + align:start position:0% +of practicing it wrong. Um and so uh you + + + align:start position:0% +of practicing it wrong. Um and so uh you +know in in applied imaginations which is + + align:start position:0% +know in in applied imaginations which is + + + align:start position:0% +know in in applied imaginations which is +where the text um you know you guys + + align:start position:0% +where the text um you know you guys + + + align:start position:0% +where the text um you know you guys +read. It's sort of him reflecting on + + align:start position:0% +read. It's sort of him reflecting on + + + align:start position:0% +read. It's sort of him reflecting on +this brainstorming idea and saying this + + align:start position:0% +this brainstorming idea and saying this + + + align:start position:0% +this brainstorming idea and saying this +is really how it how it should be uh how + + align:start position:0% +is really how it how it should be uh how + + + align:start position:0% +is really how it how it should be uh how +it should be exercised. Um the first + + align:start position:0% +it should be exercised. Um the first + + + align:start position:0% +it should be exercised. Um the first +principle is single-handedly the most + + align:start position:0% +principle is single-handedly the most + + + align:start position:0% +principle is single-handedly the most +important principle. Um and that's no + + align:start position:0% +important principle. Um and that's no + + + align:start position:0% +important principle. Um and that's no +criticism. Um, that's a that's kind of a + + align:start position:0% +criticism. Um, that's a that's kind of a + + + align:start position:0% +criticism. Um, that's a that's kind of a +blanket way of of saying it, but but + + align:start position:0% +blanket way of of saying it, but but + + + align:start position:0% +blanket way of of saying it, but but +really in a more uh in a more um broad + + align:start position:0% +really in a more uh in a more um broad + + + align:start position:0% +really in a more uh in a more um broad +sense, it's it's kind of saying uh you + + align:start position:0% +sense, it's it's kind of saying uh you + + + align:start position:0% +sense, it's it's kind of saying uh you +know, judgment needs to be excluded. Um, + + align:start position:0% +know, judgment needs to be excluded. Um, + + + align:start position:0% +know, judgment needs to be excluded. Um, +in some sense, it's kind of um kind of + + align:start position:0% +in some sense, it's kind of um kind of + + + align:start position:0% +in some sense, it's kind of um kind of +both positive and negative, but but + + align:start position:0% +both positive and negative, but but + + + align:start position:0% +both positive and negative, but but +especially you don't want to criticize + + align:start position:0% +especially you don't want to criticize + + + align:start position:0% +especially you don't want to criticize +each other's work. Um, you also don't + + align:start position:0% +each other's work. Um, you also don't + + + align:start position:0% +each other's work. Um, you also don't +want to spend time during a brainstorm + + align:start position:0% +want to spend time during a brainstorm + + + align:start position:0% +want to spend time during a brainstorm +session talking about how good an idea + + align:start position:0% +session talking about how good an idea + + + align:start position:0% +session talking about how good an idea +is, right? If if someone throws out an + + align:start position:0% +is, right? If if someone throws out an + + + align:start position:0% +is, right? If if someone throws out an +idea um and and someone's like, "Oh, + + align:start position:0% +idea um and and someone's like, "Oh, + + + align:start position:0% +idea um and and someone's like, "Oh, +this is the best idea. We don't even + + align:start position:0% +this is the best idea. We don't even + + + align:start position:0% +this is the best idea. We don't even +need to keep going anymore." Then it's + + align:start position:0% +need to keep going anymore." Then it's + + + align:start position:0% +need to keep going anymore." Then it's +like, "Oh, no. Wait, now we're not + + align:start position:0% +like, "Oh, no. Wait, now we're not + + + align:start position:0% +like, "Oh, no. Wait, now we're not +brainstorming anymore." Um and so + + align:start position:0% +brainstorming anymore." Um and so + + + align:start position:0% +brainstorming anymore." Um and so +really, you know, judgment is is is + + align:start position:0% +really, you know, judgment is is is + + + align:start position:0% +really, you know, judgment is is is +absolutely supposed to be excluded from + + align:start position:0% +absolutely supposed to be excluded from + + + align:start position:0% +absolutely supposed to be excluded from +the process. Um + + align:start position:0% +the process. Um + + + align:start position:0% +the process. Um +I think that uh this is the primary uh + + align:start position:0% +I think that uh this is the primary uh + + + align:start position:0% +I think that uh this is the primary uh +principle that goes against that social + + align:start position:0% +principle that goes against that social + + + align:start position:0% +principle that goes against that social +pressure, right? Because the social + + align:start position:0% +pressure, right? Because the social + + + align:start position:0% +pressure, right? Because the social +pressure of judgment, the people who are + + align:start position:0% +pressure of judgment, the people who are + + + align:start position:0% +pressure of judgment, the people who are +saying, whether you have an executive + + align:start position:0% +saying, whether you have an executive + + + align:start position:0% +saying, whether you have an executive +who's in charge of you, a boss who's + + align:start position:0% +who's in charge of you, a boss who's + + + align:start position:0% +who's in charge of you, a boss who's +saying whether or not the ideas are good + + align:start position:0% +saying whether or not the ideas are good + + + align:start position:0% +saying whether or not the ideas are good +or bad, or whether you have colleagues + + align:start position:0% +or bad, or whether you have colleagues + + + align:start position:0% +or bad, or whether you have colleagues +that are saying whether or not ideas are + + align:start position:0% +that are saying whether or not ideas are + + + align:start position:0% +that are saying whether or not ideas are +good or bad, that sort of social + + align:start position:0% +good or bad, that sort of social + + + align:start position:0% +good or bad, that sort of social +pressure that forces people to stay + + align:start position:0% +pressure that forces people to stay + + + align:start position:0% +pressure that forces people to stay +quiet and maybe hold on to good ideas or + + align:start position:0% +quiet and maybe hold on to good ideas or + + + align:start position:0% +quiet and maybe hold on to good ideas or +throw away good ideas. Um, you know, if + + align:start position:0% +throw away good ideas. Um, you know, if + + + align:start position:0% +throw away good ideas. Um, you know, if +everybody's on board with the lack of + + align:start position:0% +everybody's on board with the lack of + + + align:start position:0% +everybody's on board with the lack of +criticism, then you you kind of have + + align:start position:0% +criticism, then you you kind of have + + + align:start position:0% +criticism, then you you kind of have +more freedom to to kind of express + + align:start position:0% +more freedom to to kind of express + + + align:start position:0% +more freedom to to kind of express +yourself. Um, you know, just just kind + + align:start position:0% +yourself. Um, you know, just just kind + + + align:start position:0% +yourself. Um, you know, just just kind +of pulling back to the text a little + + align:start position:0% +of pulling back to the text a little + + + align:start position:0% +of pulling back to the text a little +bit, um, you know, there was this this + + align:start position:0% +bit, um, you know, there was this this + + + align:start position:0% +bit, um, you know, there was this this +great quote um from this vice president. + + align:start position:0% +great quote um from this vice president. + + + align:start position:0% +great quote um from this vice president. +I just I'll read to you guys again. Uh + + align:start position:0% +I just I'll read to you guys again. Uh + + + align:start position:0% +I just I'll read to you guys again. Uh +you know, he said, "It was hard to get + + align:start position:0% +you know, he said, "It was hard to get + + + align:start position:0% +you know, he said, "It was hard to get +through my head uh what you were trying + + align:start position:0% +through my head uh what you were trying + + + align:start position:0% +through my head uh what you were trying +to do with us. Uh my 15 years of + + align:start position:0% +to do with us. Uh my 15 years of + + + align:start position:0% +to do with us. Uh my 15 years of +conference after conference in my + + align:start position:0% +conference after conference in my + + + align:start position:0% +conference after conference in my +company have conditioned me against + + align:start position:0% +company have conditioned me against + + + align:start position:0% +company have conditioned me against +shooting while um almost all of us + + align:start position:0% +shooting while um almost all of us + + + align:start position:0% +shooting while um almost all of us +officers rate each other on the basis of + + align:start position:0% +officers rate each other on the basis of + + + align:start position:0% +officers rate each other on the basis of +judgment. Uh we are far more apt to look + + align:start position:0% +judgment. Uh we are far more apt to look + + + align:start position:0% +judgment. Uh we are far more apt to look +up to the other fellow if he makes no + + align:start position:0% +up to the other fellow if he makes no + + + align:start position:0% +up to the other fellow if he makes no +mistakes than if he suggests lots of + + align:start position:0% +mistakes than if he suggests lots of + + + align:start position:0% +mistakes than if he suggests lots of +ideas." That's something that may sound + + align:start position:0% +ideas." That's something that may sound + + + align:start position:0% +ideas." That's something that may sound +familiar to you. Um so I've always kept + + align:start position:0% +familiar to you. Um so I've always kept + + + align:start position:0% +familiar to you. Um so I've always kept +myself from spouting any suggestions + + align:start position:0% +myself from spouting any suggestions + + + align:start position:0% +myself from spouting any suggestions +which could be sneered at. uh I wish our + + align:start position:0% +which could be sneered at. uh I wish our + + + align:start position:0% +which could be sneered at. uh I wish our +people would feel free to shoot ideas + + align:start position:0% +people would feel free to shoot ideas + + + align:start position:0% +people would feel free to shoot ideas +the way we have been doing in these + + align:start position:0% +the way we have been doing in these + + + align:start position:0% +the way we have been doing in these +brainstorm sessions. And so really like + + align:start position:0% +brainstorm sessions. And so really like + + + align:start position:0% +brainstorm sessions. And so really like +um this this lack of criticism, this + + align:start position:0% +um this this lack of criticism, this + + + align:start position:0% +um this this lack of criticism, this +sort of creating a safe environment for + + align:start position:0% +sort of creating a safe environment for + + + align:start position:0% +sort of creating a safe environment for +ideiation um is is the most fundamental + + align:start position:0% +ideiation um is is the most fundamental + + + align:start position:0% +ideiation um is is the most fundamental +principle in this brainstorm. Um and it + + align:start position:0% +principle in this brainstorm. Um and it + + + align:start position:0% +principle in this brainstorm. Um and it +really goes right at those social + + align:start position:0% +really goes right at those social + + + align:start position:0% +really goes right at those social +pressures which which can stop you know + + align:start position:0% +pressures which which can stop you know + + + align:start position:0% +pressures which which can stop you know +creativity and really hamper creativity. + + align:start position:0% +creativity and really hamper creativity. + + + align:start position:0% +creativity and really hamper creativity. +Um any questions about that? That sort + + align:start position:0% +Um any questions about that? That sort + + + align:start position:0% +Um any questions about that? That sort +of makes sense, right? This principle of + + align:start position:0% +of makes sense, right? This principle of + + + align:start position:0% +of makes sense, right? This principle of +of no criticism. Cool. Um, + + align:start position:0% +of no criticism. Cool. Um, + + + align:start position:0% +of no criticism. Cool. Um, +principle number two, uh, freewheeling, + + align:start position:0% +principle number two, uh, freewheeling, + + + align:start position:0% +principle number two, uh, freewheeling, +as uh, Mr. Osborne likes to call it. The + + align:start position:0% +as uh, Mr. Osborne likes to call it. The + + + align:start position:0% +as uh, Mr. Osborne likes to call it. The +wilder idea the better. This is also + + align:start position:0% +wilder idea the better. This is also + + + align:start position:0% +wilder idea the better. This is also +hard, uh, to kind of get used to. Um, + + align:start position:0% +hard, uh, to kind of get used to. Um, + + + align:start position:0% +hard, uh, to kind of get used to. Um, +again, it was like the guy said in that + + align:start position:0% +again, it was like the guy said in that + + + align:start position:0% +again, it was like the guy said in that +quote, you know, you you resist the urge + + align:start position:0% +quote, you know, you you resist the urge + + + align:start position:0% +quote, you know, you you resist the urge +to throw out something that's absolutely + + align:start position:0% +to throw out something that's absolutely + + + align:start position:0% +to throw out something that's absolutely +crazy and absolutely wild for the fear + + align:start position:0% +crazy and absolutely wild for the fear + + + align:start position:0% +crazy and absolutely wild for the fear +of ridicule. Well, if we eliminate the + + align:start position:0% +of ridicule. Well, if we eliminate the + + + align:start position:0% +of ridicule. Well, if we eliminate the +fear of ridicule and we understand that + + align:start position:0% +fear of ridicule and we understand that + + + align:start position:0% +fear of ridicule and we understand that +we're just trying to get every idea that + + align:start position:0% +we're just trying to get every idea that + + + align:start position:0% +we're just trying to get every idea that +we can um then freewheeling is is + + align:start position:0% +we can um then freewheeling is is + + + align:start position:0% +we can um then freewheeling is is +absolutely encouraged and you need to + + align:start position:0% +absolutely encouraged and you need to + + + align:start position:0% +absolutely encouraged and you need to +kind of get past that um past that oh + + align:start position:0% +kind of get past that um past that oh + + + align:start position:0% +kind of get past that um past that oh +you know this is whatever we're known + + align:start position:0% +you know this is whatever we're known + + + align:start position:0% +you know this is whatever we're known +whatever like this um and I can you know + + align:start position:0% +whatever like this um and I can you know + + + align:start position:0% +whatever like this um and I can you know +I I put up Kadamari dysi up here because + + align:start position:0% +I I put up Kadamari dysi up here because + + + align:start position:0% +I I put up Kadamari dysi up here because +you know that that's the sort of idea + + align:start position:0% +you know that that's the sort of idea + + + align:start position:0% +you know that that's the sort of idea +that someone throws out at a at a at a + + align:start position:0% +that someone throws out at a at a at a + + + align:start position:0% +that someone throws out at a at a at a +meeting um and if there's criticism + + align:start position:0% +meeting um and if there's criticism + + + align:start position:0% +meeting um and if there's criticism +someone will be like that's the dumbest + + align:start position:0% +someone will be like that's the dumbest + + + align:start position:0% +someone will be like that's the dumbest +thing I've ever heard. you can't just + + align:start position:0% +thing I've ever heard. you can't just + + + align:start position:0% +thing I've ever heard. you can't just +roll around picking up stuff for the + + align:start position:0% +roll around picking up stuff for the + + + align:start position:0% +roll around picking up stuff for the +king of the cosmos. That's insane. Um + + align:start position:0% +king of the cosmos. That's insane. Um + + + align:start position:0% +king of the cosmos. That's insane. Um +and and it probably, you know, it + + align:start position:0% +and and it probably, you know, it + + + align:start position:0% +and and it probably, you know, it +probably was a synthesis of a lot of + + align:start position:0% +probably was a synthesis of a lot of + + + align:start position:0% +probably was a synthesis of a lot of +different ideas that that kind of + + align:start position:0% +different ideas that that kind of + + + align:start position:0% +different ideas that that kind of +created that game, which we'll talk + + align:start position:0% +created that game, which we'll talk + + + align:start position:0% +created that game, which we'll talk +about later, but um really, you know, + + align:start position:0% +about later, but um really, you know, + + + align:start position:0% +about later, but um really, you know, +having these like kind of wild, crazy + + align:start position:0% +having these like kind of wild, crazy + + + align:start position:0% +having these like kind of wild, crazy +ideas. You may think it's over the edge, + + align:start position:0% +ideas. You may think it's over the edge, + + + align:start position:0% +ideas. You may think it's over the edge, +and it might be over the edge. Um, but + + align:start position:0% +and it might be over the edge. Um, but + + + align:start position:0% +and it might be over the edge. Um, but +it is it is way easier to make something + + align:start position:0% +it is it is way easier to make something + + + align:start position:0% +it is it is way easier to make something +feasible than it is to take something + + align:start position:0% +feasible than it is to take something + + + align:start position:0% +feasible than it is to take something +that's pretty um pretty normal and make + + align:start position:0% +that's pretty um pretty normal and make + + + align:start position:0% +that's pretty um pretty normal and make +it make it innovative and interesting, + + align:start position:0% +it make it innovative and interesting, + + + align:start position:0% +it make it innovative and interesting, +right? It's it's much easier to kind of + + align:start position:0% +right? It's it's much easier to kind of + + + align:start position:0% +right? It's it's much easier to kind of +go go in that backward direction. Um, + + align:start position:0% +go go in that backward direction. Um, + + + align:start position:0% +go go in that backward direction. Um, +and so really the wilder idea the idea + + align:start position:0% +and so really the wilder idea the idea + + + align:start position:0% +and so really the wilder idea the idea +you can come up with the the the + + align:start position:0% +you can come up with the the the + + + align:start position:0% +you can come up with the the the +stronger. Um, + + align:start position:0% +stronger. Um, + + + align:start position:0% +stronger. Um, +any questions about principle number + + align:start position:0% +any questions about principle number + + + align:start position:0% +any questions about principle number +two? Making sense on board? Cool. Uh, + + align:start position:0% +two? Making sense on board? Cool. Uh, + + + align:start position:0% +two? Making sense on board? Cool. Uh, +quantity. Um, this is really the the + + align:start position:0% +quantity. Um, this is really the the + + + align:start position:0% +quantity. Um, this is really the the +goal of of a brainstorming session. Come + + align:start position:0% +goal of of a brainstorming session. Come + + + align:start position:0% +goal of of a brainstorming session. Come +up with as many ideas as you can, right? + + align:start position:0% +up with as many ideas as you can, right? + + + align:start position:0% +up with as many ideas as you can, right? +Um, it it stands to reason that if you + + align:start position:0% +Um, it it stands to reason that if you + + + align:start position:0% +Um, it it stands to reason that if you +have lots of ideas, there's a greater + + align:start position:0% +have lots of ideas, there's a greater + + + align:start position:0% +have lots of ideas, there's a greater +likelihood that you'll have a useful one + + align:start position:0% +likelihood that you'll have a useful one + + + align:start position:0% +likelihood that you'll have a useful one +um than if say you have two. Your + + align:start position:0% +um than if say you have two. Your + + + align:start position:0% +um than if say you have two. Your +choices are limited. You didn't pick the + + align:start position:0% +choices are limited. You didn't pick the + + + align:start position:0% +choices are limited. You didn't pick the +better of the two, I suppose, but it + + align:start position:0% +better of the two, I suppose, but it + + + align:start position:0% +better of the two, I suppose, but it +might not be the best idea you have. Um, + + align:start position:0% +might not be the best idea you have. Um, + + + align:start position:0% +might not be the best idea you have. Um, +and so really this is, you know, this + + align:start position:0% +and so really this is, you know, this + + + align:start position:0% +and so really this is, you know, this +adds on to that wild idea. Throw + + align:start position:0% +adds on to that wild idea. Throw + + + align:start position:0% +adds on to that wild idea. Throw +everything out you can. you need to just + + align:start position:0% +everything out you can. you need to just + + + align:start position:0% +everything out you can. you need to just +get everything um out and everything on + + align:start position:0% +get everything um out and everything on + + + align:start position:0% +get everything um out and everything on +on on the page um in order to even be + + align:start position:0% +on on the page um in order to even be + + + align:start position:0% +on on the page um in order to even be +able to start judging it. And that's the + + align:start position:0% +able to start judging it. And that's the + + + align:start position:0% +able to start judging it. And that's the +important thing too that that needs to + + align:start position:0% +important thing too that that needs to + + + align:start position:0% +important thing too that that needs to +be um that needs to be clarified is that + + align:start position:0% +be um that needs to be clarified is that + + + align:start position:0% +be um that needs to be clarified is that +brainstorming is a first step in a + + align:start position:0% +brainstorming is a first step in a + + + align:start position:0% +brainstorming is a first step in a +creative process. It's not the whole + + align:start position:0% +creative process. It's not the whole + + + align:start position:0% +creative process. It's not the whole +process. It's not like, oh, we've got + + align:start position:0% +process. It's not like, oh, we've got + + + align:start position:0% +process. It's not like, oh, we've got +this creative problem that we need to + + align:start position:0% +this creative problem that we need to + + + align:start position:0% +this creative problem that we need to +solve. We'll have a brainstorming + + align:start position:0% +solve. We'll have a brainstorming + + + align:start position:0% +solve. We'll have a brainstorming +session, then we'll have it. Um, and + + align:start position:0% +session, then we'll have it. Um, and + + + align:start position:0% +session, then we'll have it. Um, and +actually that's that's something that + + align:start position:0% +actually that's that's something that + + + align:start position:0% +actually that's that's something that +hampers brainstorming a lot is that you + + align:start position:0% +hampers brainstorming a lot is that you + + + align:start position:0% +hampers brainstorming a lot is that you +have the brainstorming session, you come + + align:start position:0% +have the brainstorming session, you come + + + align:start position:0% +have the brainstorming session, you come +up with these great ideas and then + + align:start position:0% +up with these great ideas and then + + + align:start position:0% +up with these great ideas and then +everybody leaves and you never return to + + align:start position:0% +everybody leaves and you never return to + + + align:start position:0% +everybody leaves and you never return to +it or you never kind of reflect on which + + align:start position:0% +it or you never kind of reflect on which + + + align:start position:0% +it or you never kind of reflect on which +of these ideas is going to be best or + + align:start position:0% +of these ideas is going to be best or + + + align:start position:0% +of these ideas is going to be best or +you kind of just end up picking one. And + + align:start position:0% +you kind of just end up picking one. And + + + align:start position:0% +you kind of just end up picking one. And +so the judgment needs to happen as well. + + align:start position:0% +so the judgment needs to happen as well. + + + align:start position:0% +so the judgment needs to happen as well. +Um, but not now, you know, during the + + align:start position:0% +Um, but not now, you know, during the + + + align:start position:0% +Um, but not now, you know, during the +brainstorm session. It's just get + + align:start position:0% +brainstorm session. It's just get + + + align:start position:0% +brainstorm session. It's just get +everything out that you can. Um, + + align:start position:0% +everything out that you can. Um, + + + align:start position:0% +everything out that you can. Um, +it it really just it kind of stands for + + align:start position:0% +it it really just it kind of stands for + + + align:start position:0% +it it really just it kind of stands for +reason. And I I kind of made fun of + + align:start position:0% +reason. And I I kind of made fun of + + + align:start position:0% +reason. And I I kind of made fun of +Storm when he was like, you know, + + align:start position:0% +Storm when he was like, you know, + + + align:start position:0% +Storm when he was like, you know, +saying, well, in this inst in the + + align:start position:0% +saying, well, in this inst in the + + + align:start position:0% +saying, well, in this inst in the +government they had 95 ideas and we you + + align:start position:0% +government they had 95 ideas and we you + + + align:start position:0% +government they had 95 ideas and we you +know came up with eight good desires + + align:start position:0% +know came up with eight good desires + + + align:start position:0% +know came up with eight good desires +which you know how many did you come up + + align:start position:0% +which you know how many did you come up + + + align:start position:0% +which you know how many did you come up +with before but but it's true just the + + align:start position:0% +with before but but it's true just the + + + align:start position:0% +with before but but it's true just the +more you have the better you're going to + + align:start position:0% +more you have the better you're going to + + + align:start position:0% +more you have the better you're going to +do + + align:start position:0% +do + + + align:start position:0% +do +and then this one is related to that + + align:start position:0% +and then this one is related to that + + + align:start position:0% +and then this one is related to that +which is the idea of synthesis or + + align:start position:0% +which is the idea of synthesis or + + + align:start position:0% +which is the idea of synthesis or +building on ideas um which is that often + + align:start position:0% +building on ideas um which is that often + + + align:start position:0% +building on ideas um which is that often +times the best idea the best creative + + align:start position:0% +times the best idea the best creative + + + align:start position:0% +times the best idea the best creative +idea is not going to be something that's + + align:start position:0% +idea is not going to be something that's + + + align:start position:0% +idea is not going to be something that's +just kind of a unique idea that stands + + align:start position:0% +just kind of a unique idea that stands + + + align:start position:0% +just kind of a unique idea that stands +alone in this corpus of ideas that + + align:start position:0% +alone in this corpus of ideas that + + + align:start position:0% +alone in this corpus of ideas that +you've collected over the brainstorm + + align:start position:0% +you've collected over the brainstorm + + + align:start position:0% +you've collected over the brainstorm +it's going to be an idea that is a + + align:start position:0% +it's going to be an idea that is a + + + align:start position:0% +it's going to be an idea that is a +synthesis of of of one idea and another + + align:start position:0% +synthesis of of of one idea and another + + + align:start position:0% +synthesis of of of one idea and another +or someone suggests an idea and then + + align:start position:0% +or someone suggests an idea and then + + + align:start position:0% +or someone suggests an idea and then +that makes you think of something else + + align:start position:0% +that makes you think of something else + + + align:start position:0% +that makes you think of something else +that's related to it and you kind of + + align:start position:0% +that's related to it and you kind of + + + align:start position:0% +that's related to it and you kind of +build on that and and you can see in + + align:start position:0% +build on that and and you can see in + + + align:start position:0% +build on that and and you can see in +really positive good brainstorming + + align:start position:0% +really positive good brainstorming + + + align:start position:0% +really positive good brainstorming +sessions um there's momentum and one of + + align:start position:0% +sessions um there's momentum and one of + + + align:start position:0% +sessions um there's momentum and one of +the things that can really hurt that + + align:start position:0% +the things that can really hurt that + + + align:start position:0% +the things that can really hurt that +momentum is when people are starting to + + align:start position:0% +momentum is when people are starting to + + + align:start position:0% +momentum is when people are starting to +riff on an idea then someone's like oh + + align:start position:0% +riff on an idea then someone's like oh + + + align:start position:0% +riff on an idea then someone's like oh +but you know in other news you know we + + align:start position:0% +but you know in other news you know we + + + align:start position:0% +but you know in other news you know we +could do this and so it's really + + align:start position:0% +could do this and so it's really + + + align:start position:0% +could do this and so it's really +encouraged that you synthesize ideas if + + align:start position:0% +encouraged that you synthesize ideas if + + + align:start position:0% +encouraged that you synthesize ideas if +you have that other left field idea + + align:start position:0% +you have that other left field idea + + + align:start position:0% +you have that other left field idea +don't throw it away right jot it down so + + align:start position:0% +don't throw it away right jot it down so + + + align:start position:0% +don't throw it away right jot it down so +that you can bring it up later but don't + + align:start position:0% +that you can bring it up later but don't + + + align:start position:0% +that you can bring it up later but don't +don't kind of kill the momentum of the + + align:start position:0% +don't kind of kill the momentum of the + + + align:start position:0% +don't kind of kill the momentum of the +synthesis if that's happening. Um it's + + align:start position:0% +synthesis if that's happening. Um it's + + + align:start position:0% +synthesis if that's happening. Um it's +it's you know kind of really important + + align:start position:0% +it's you know kind of really important + + + align:start position:0% +it's you know kind of really important +that you start um it's the collaborative + + align:start position:0% +that you start um it's the collaborative + + + align:start position:0% +that you start um it's the collaborative +part of this creative uh ideiation. Um + + align:start position:0% +part of this creative uh ideiation. Um + + + align:start position:0% +part of this creative uh ideiation. Um +it's this combining of ideas that's + + align:start position:0% +it's this combining of ideas that's + + + align:start position:0% +it's this combining of ideas that's +going to create um good ideas. And + + align:start position:0% +going to create um good ideas. And + + + align:start position:0% +going to create um good ideas. And +that's that's just um I I think we can + + align:start position:0% +that's that's just um I I think we can + + + align:start position:0% +that's that's just um I I think we can +kind of take that as a given that if you + + align:start position:0% +kind of take that as a given that if you + + + align:start position:0% +kind of take that as a given that if you +collect a bunch of skilled, thoughtful, + + align:start position:0% +collect a bunch of skilled, thoughtful, + + + align:start position:0% +collect a bunch of skilled, thoughtful, +creative people together um combining + + align:start position:0% +creative people together um combining + + + align:start position:0% +creative people together um combining +their ideas is going to create something + + align:start position:0% +their ideas is going to create something + + + align:start position:0% +their ideas is going to create something +that's better than just the any one idea + + align:start position:0% +that's better than just the any one idea + + + align:start position:0% +that's better than just the any one idea +that one creative uh professional is + + align:start position:0% +that one creative uh professional is + + + align:start position:0% +that one creative uh professional is +going to have or at least just a + + align:start position:0% +going to have or at least just a + + + align:start position:0% +going to have or at least just a +different solution that might be more + + align:start position:0% +different solution that might be more + + + align:start position:0% +different solution that might be more +ideal given the problem. And so, you + + align:start position:0% +ideal given the problem. And so, you + + + align:start position:0% +ideal given the problem. And so, you +know, you can think of things like, you + + align:start position:0% +know, you can think of things like, you + + + align:start position:0% +know, you can think of things like, you +know, Lego's pretty awesome. Um, Star + + align:start position:0% +know, Lego's pretty awesome. Um, Star + + + align:start position:0% +know, Lego's pretty awesome. Um, Star +Wars is also pretty awesome, + + align:start position:0% +Wars is also pretty awesome, + + + align:start position:0% +Wars is also pretty awesome, +but you know, Lego Star Wars move is is + + align:start position:0% +but you know, Lego Star Wars move is is + + + align:start position:0% +but you know, Lego Star Wars move is is +also awesome. You know, similarly, um, + + align:start position:0% +also awesome. You know, similarly, um, + + + align:start position:0% +also awesome. You know, similarly, um, +you know, Marvel's dope. Um, Capcom's + + align:start position:0% +you know, Marvel's dope. Um, Capcom's + + + align:start position:0% +you know, Marvel's dope. Um, Capcom's +also pretty dope. Marvel versus Capcom + + align:start position:0% +also pretty dope. Marvel versus Capcom + + + align:start position:0% +also pretty dope. Marvel versus Capcom +is tremendously dope. So, um, you know, + + align:start position:0% +is tremendously dope. So, um, you know, + + + align:start position:0% +is tremendously dope. So, um, you know, +building on ideas can create obviously + + align:start position:0% +building on ideas can create obviously + + + align:start position:0% +building on ideas can create obviously +really interesting things and that's, + + align:start position:0% +really interesting things and that's, + + + align:start position:0% +really interesting things and that's, +you know, it's a good idea to kind of + + align:start position:0% +you know, it's a good idea to kind of + + + align:start position:0% +you know, it's a good idea to kind of +keep working on that in your brainstorm + + align:start position:0% +keep working on that in your brainstorm + + + align:start position:0% +keep working on that in your brainstorm +sessions, like what can you what can you + + align:start position:0% +sessions, like what can you what can you + + + align:start position:0% +sessions, like what can you what can you +put together? Um, + + align:start position:0% +put together? Um, + + + align:start position:0% +put together? Um, +so how is it organized? Um, you know, + + align:start position:0% +so how is it organized? Um, you know, + + + align:start position:0% +so how is it organized? Um, you know, +we've kind of talked about basic + + align:start position:0% +we've kind of talked about basic + + + align:start position:0% +we've kind of talked about basic +principles. Any questions about those + + align:start position:0% +principles. Any questions about those + + + align:start position:0% +principles. Any questions about those +four principles? Do they all make sense? + + align:start position:0% +four principles? Do they all make sense? + + + align:start position:0% +four principles? Do they all make sense? +Do they all seem to be grounded in + + align:start position:0% +Do they all seem to be grounded in + + + align:start position:0% +Do they all seem to be grounded in +the greatest? All right. Um, + + align:start position:0% +the greatest? All right. Um, + + + align:start position:0% +the greatest? All right. Um, +so the question becomes then, how do you + + align:start position:0% +so the question becomes then, how do you + + + align:start position:0% +so the question becomes then, how do you +organize um how do you organize your + + align:start position:0% +organize um how do you organize your + + + align:start position:0% +organize um how do you organize your +brainstorm? One of the points that Alex + + align:start position:0% +brainstorm? One of the points that Alex + + + align:start position:0% +brainstorm? One of the points that Alex +Osborne makes is that um it needs to + + align:start position:0% +Osborne makes is that um it needs to + + + align:start position:0% +Osborne makes is that um it needs to +have a casual spirit or a casual + + align:start position:0% +have a casual spirit or a casual + + + align:start position:0% +have a casual spirit or a casual +atmosphere. He refers to it as a picnic, + + align:start position:0% +atmosphere. He refers to it as a picnic, + + + align:start position:0% +atmosphere. He refers to it as a picnic, +which is another one of those I haven't + + align:start position:0% +which is another one of those I haven't + + + align:start position:0% +which is another one of those I haven't +been on a picnic in a really long time, + + align:start position:0% +been on a picnic in a really long time, + + + align:start position:0% +been on a picnic in a really long time, +but um but you know, it's like yes, we + + align:start position:0% +but um but you know, it's like yes, we + + + align:start position:0% +but um but you know, it's like yes, we +brought our lunches in and then we + + align:start position:0% +brought our lunches in and then we + + + align:start position:0% +brought our lunches in and then we +talked afterwards. It's like what we + + align:start position:0% +talked afterwards. It's like what we + + + align:start position:0% +talked afterwards. It's like what we +call those lunch meetings now. But um + + align:start position:0% +call those lunch meetings now. But um + + + align:start position:0% +call those lunch meetings now. But um +but he has a good point that if um if a + + align:start position:0% +but he has a good point that if um if a + + + align:start position:0% +but he has a good point that if um if a +large part of the brainstorming session + + align:start position:0% +large part of the brainstorming session + + + align:start position:0% +large part of the brainstorming session +is intended to combat um social + + align:start position:0% +is intended to combat um social + + + align:start position:0% +is intended to combat um social +pressures that stop you from being + + align:start position:0% +pressures that stop you from being + + + align:start position:0% +pressures that stop you from being +creative, that inhibit your creativity, + + align:start position:0% +creative, that inhibit your creativity, + + + align:start position:0% +creative, that inhibit your creativity, +then it would stand to reason that + + align:start position:0% +then it would stand to reason that + + + align:start position:0% +then it would stand to reason that +creating a casual spirit, a casual + + align:start position:0% +creating a casual spirit, a casual + + + align:start position:0% +creating a casual spirit, a casual +environment um for this process is + + align:start position:0% +environment um for this process is + + + align:start position:0% +environment um for this process is +important. Um, and so I have, you know, + + align:start position:0% +important. Um, and so I have, you know, + + + align:start position:0% +important. Um, and so I have, you know, +it's hard to most video game processes + + align:start position:0% +it's hard to most video game processes + + + align:start position:0% +it's hard to most video game processes +and most video game companies have a + + align:start position:0% +and most video game companies have a + + + align:start position:0% +and most video game companies have a +pretty casual spirit and environment + + align:start position:0% +pretty casual spirit and environment + + + align:start position:0% +pretty casual spirit and environment +because of the nature of the work in + + align:start position:0% +because of the nature of the work in + + + align:start position:0% +because of the nature of the work in +general. Um, so sometimes this might not + + align:start position:0% +general. Um, so sometimes this might not + + + align:start position:0% +general. Um, so sometimes this might not +be that hard, but um, you know, things + + align:start position:0% +be that hard, but um, you know, things + + + align:start position:0% +be that hard, but um, you know, things +to consider are like what is the makeup + + align:start position:0% +to consider are like what is the makeup + + + align:start position:0% +to consider are like what is the makeup +of your team, right? If there's, you + + align:start position:0% +of your team, right? If there's, you + + + align:start position:0% +of your team, right? If there's, you +know, if your president of the company + + align:start position:0% +know, if your president of the company + + + align:start position:0% +know, if your president of the company +does a really bad job of putting himself + + align:start position:0% +does a really bad job of putting himself + + + align:start position:0% +does a really bad job of putting himself +or herself on the same level as all the + + align:start position:0% +or herself on the same level as all the + + + align:start position:0% +or herself on the same level as all the +people, you might want to exclude that + + align:start position:0% +people, you might want to exclude that + + + align:start position:0% +people, you might want to exclude that +person from the brainstorming session + + align:start position:0% +person from the brainstorming session + + + align:start position:0% +person from the brainstorming session +because then everybody's going to feel + + align:start position:0% +because then everybody's going to feel + + + align:start position:0% +because then everybody's going to feel +the pressure of the president, you know, + + align:start position:0% +the pressure of the president, you know, + + + align:start position:0% +the pressure of the president, you know, +and we, you know, do we need to make an + + align:start position:0% +and we, you know, do we need to make an + + + align:start position:0% +and we, you know, do we need to make an +idea that makes that person happy. It's, + + align:start position:0% +idea that makes that person happy. It's, + + + align:start position:0% +idea that makes that person happy. It's, +you know, you have to think these things + + align:start position:0% +you know, you have to think these things + + + align:start position:0% +you know, you have to think these things +through in terms of what the environment + + align:start position:0% +through in terms of what the environment + + + align:start position:0% +through in terms of what the environment +is going to be for your brainstorming + + align:start position:0% +is going to be for your brainstorming + + + align:start position:0% +is going to be for your brainstorming +session and and who's involved. Um, so + + align:start position:0% +session and and who's involved. Um, so + + + align:start position:0% +session and and who's involved. Um, so +it it is an important point is an + + align:start position:0% +it it is an important point is an + + + align:start position:0% +it it is an important point is an +important step. um you know starting + + align:start position:0% +important step. um you know starting + + + align:start position:0% +important step. um you know starting +with a a bad or or a worthless idea uh + + align:start position:0% +with a a bad or or a worthless idea uh + + + align:start position:0% +with a a bad or or a worthless idea uh +encourages that freewheeling sense. Um + + align:start position:0% +encourages that freewheeling sense. Um + + + align:start position:0% +encourages that freewheeling sense. Um +you know a lot of times people will + + align:start position:0% +you know a lot of times people will + + + align:start position:0% +you know a lot of times people will +contribute ideas that feel safe. Again + + align:start position:0% +contribute ideas that feel safe. Again + + + align:start position:0% +contribute ideas that feel safe. Again +you want to come up with the most ideas + + align:start position:0% +you want to come up with the most ideas + + + align:start position:0% +you want to come up with the most ideas +that you can. Um so you know having + + align:start position:0% +that you can. Um so you know having + + + align:start position:0% +that you can. Um so you know having +someone with the courage or even + + align:start position:0% +someone with the courage or even + + + align:start position:0% +someone with the courage or even +bringing to the beginning of it a a + + align:start position:0% +bringing to the beginning of it a a + + + align:start position:0% +bringing to the beginning of it a a +crazy worthless bad freewheeling idea + + align:start position:0% +crazy worthless bad freewheeling idea + + + align:start position:0% +crazy worthless bad freewheeling idea +can help kind of encourage people to + + align:start position:0% +can help kind of encourage people to + + + align:start position:0% +can help kind of encourage people to +keep doing that. So, um, you know, + + align:start position:0% +keep doing that. So, um, you know, + + + align:start position:0% +keep doing that. So, um, you know, +either starting with someone who has a + + align:start position:0% +either starting with someone who has a + + + align:start position:0% +either starting with someone who has a +crazy idea or even bringing it to the + + align:start position:0% +crazy idea or even bringing it to the + + + align:start position:0% +crazy idea or even bringing it to the +brainstorm at the very beginning can be + + align:start position:0% +brainstorm at the very beginning can be + + + align:start position:0% +brainstorm at the very beginning can be +a really good thing as well. Um, this is + + align:start position:0% +a really good thing as well. Um, this is + + + align:start position:0% +a really good thing as well. Um, this is +kind of a key one. Don't uh don't + + align:start position:0% +kind of a key one. Don't uh don't + + + align:start position:0% +kind of a key one. Don't uh don't +interrupt anyone. Um, it it's really + + align:start position:0% +interrupt anyone. Um, it it's really + + + align:start position:0% +interrupt anyone. Um, it it's really +important in a brainstorming session to + + align:start position:0% +important in a brainstorming session to + + + align:start position:0% +important in a brainstorming session to +encourage um that every voice is heard. + + align:start position:0% +encourage um that every voice is heard. + + + align:start position:0% +encourage um that every voice is heard. +Um, you know, there's there's these kind + + align:start position:0% +Um, you know, there's there's these kind + + + align:start position:0% +Um, you know, there's there's these kind +of uh let me see if I can find that + + align:start position:0% +of uh let me see if I can find that + + + align:start position:0% +of uh let me see if I can find that +quote from that one guy. Um, yeah, here + + align:start position:0% +quote from that one guy. Um, yeah, here + + + align:start position:0% +quote from that one guy. Um, yeah, here +we go. Um, it's great. I was think up or + + align:start position:0% +we go. Um, it's great. I was think up or + + + align:start position:0% +we go. Um, it's great. I was think up or +think up or shut up. + + align:start position:0% +think up or shut up. + + + align:start position:0% +think up or shut up. +>> Oh, well, yeah, there's that one, too, + + align:start position:0% +>> Oh, well, yeah, there's that one, too, + + + align:start position:0% +>> Oh, well, yeah, there's that one, too, +which is a good one. Yeah, but um uh let + + align:start position:0% +which is a good one. Yeah, but um uh let + + + align:start position:0% +which is a good one. Yeah, but um uh let +me just It's talking about the spirit of + + align:start position:0% +me just It's talking about the spirit of + + + align:start position:0% +me just It's talking about the spirit of +a brainstorm session is important. Uh + + align:start position:0% +a brainstorm session is important. Uh + + + align:start position:0% +a brainstorm session is important. Uh +self- encouragement is needed almost as + + align:start position:0% +self- encouragement is needed almost as + + + align:start position:0% +self- encouragement is needed almost as +much as mutual encouragement. Uh a + + align:start position:0% +much as mutual encouragement. Uh a + + + align:start position:0% +much as mutual encouragement. Uh a +perfectionism complex will throttle + + align:start position:0% +perfectionism complex will throttle + + + align:start position:0% +perfectionism complex will throttle +effort and abort ideas. Uh he says, "One + + align:start position:0% +effort and abort ideas. Uh he says, "One + + + align:start position:0% +effort and abort ideas. Uh he says, "One +of the ablest members kept mom + + align:start position:0% +of the ablest members kept mom + + + align:start position:0% +of the ablest members kept mom +throughout one of our sessions. I button + + align:start position:0% +throughout one of our sessions. I button + + + align:start position:0% +throughout one of our sessions. I button +hold him, never heard that expression, + + align:start position:0% +hold him, never heard that expression, + + + align:start position:0% +hold him, never heard that expression, +afterward and begged him to spout + + align:start position:0% +afterward and begged him to spout + + + align:start position:0% +afterward and begged him to spout +whatever ideas might come to his mind in + + align:start position:0% +whatever ideas might come to his mind in + + + align:start position:0% +whatever ideas might come to his mind in +our next meeting." And this is this is + + align:start position:0% +our next meeting." And this is this is + + + align:start position:0% +our next meeting." And this is this is +where it gets good. this is the, you + + align:start position:0% +where it gets good. this is the, you + + + align:start position:0% +where it gets good. this is the, you +know, really able uh member of this ad + + align:start position:0% +know, really able uh member of this ad + + + align:start position:0% +know, really able uh member of this ad +team. He says, "All right, I'll try." + + align:start position:0% +team. He says, "All right, I'll try." + + + align:start position:0% +team. He says, "All right, I'll try." +Uh, but here's what happened. After our + + align:start position:0% +Uh, but here's what happened. After our + + + align:start position:0% +Uh, but here's what happened. After our +first meeting, I jotted down about 15 + + align:start position:0% +first meeting, I jotted down about 15 + + + align:start position:0% +first meeting, I jotted down about 15 +ideas with the thought that I would + + align:start position:0% +ideas with the thought that I would + + + align:start position:0% +ideas with the thought that I would +bring them to our next session. When I + + align:start position:0% +bring them to our next session. When I + + + align:start position:0% +bring them to our next session. When I +looked them over, I decided they were + + align:start position:0% +looked them over, I decided they were + + + align:start position:0% +looked them over, I decided they were +worthless, so I just tore up the list. + + align:start position:0% +worthless, so I just tore up the list. + + + align:start position:0% +worthless, so I just tore up the list. +Um, and you know, Alice kind of goes on + + align:start position:0% +Um, and you know, Alice kind of goes on + + + align:start position:0% +Um, and you know, Alice kind of goes on +to say, "It took a while to encourage + + align:start position:0% +to say, "It took a while to encourage + + + align:start position:0% +to say, "It took a while to encourage +this guy to understand that there's no + + align:start position:0% +this guy to understand that there's no + + + align:start position:0% +this guy to understand that there's no +such thing as a worthless idea. Um, that + + align:start position:0% +such thing as a worthless idea. Um, that + + + align:start position:0% +such thing as a worthless idea. Um, that +that it can either be expanded upon or + + align:start position:0% +that it can either be expanded upon or + + + align:start position:0% +that it can either be expanded upon or +revise." And that's kind of that + + align:start position:0% +revise." And that's kind of that + + + align:start position:0% +revise." And that's kind of that +synthesis thing, right? that that you + + align:start position:0% +synthesis thing, right? that that you + + + align:start position:0% +synthesis thing, right? that that you +know having a wild idea and and um you + + align:start position:0% +know having a wild idea and and um you + + + align:start position:0% +know having a wild idea and and um you +know getting back to this idea of the + + align:start position:0% +know getting back to this idea of the + + + align:start position:0% +know getting back to this idea of the +interruption. Nothing will stop a person + + align:start position:0% +interruption. Nothing will stop a person + + + align:start position:0% +interruption. Nothing will stop a person +from wanting to contribute if um more + + align:start position:0% +from wanting to contribute if um more + + + align:start position:0% +from wanting to contribute if um more +than than not being able to even have + + align:start position:0% +than than not being able to even have + + + align:start position:0% +than than not being able to even have +their voice be heard, right? Like + + align:start position:0% +their voice be heard, right? Like + + + align:start position:0% +their voice be heard, right? Like +they're trying to say something and then + + align:start position:0% +they're trying to say something and then + + + align:start position:0% +they're trying to say something and then +they just get cut out by somebody else + + align:start position:0% +they just get cut out by somebody else + + + align:start position:0% +they just get cut out by somebody else +who's like, "No, but this is better." Um + + align:start position:0% +who's like, "No, but this is better." Um + + + align:start position:0% +who's like, "No, but this is better." Um +you know, especially for a shy person or + + align:start position:0% +you know, especially for a shy person or + + + align:start position:0% +you know, especially for a shy person or +a person who's otherwise feeling like my + + align:start position:0% +a person who's otherwise feeling like my + + + align:start position:0% +a person who's otherwise feeling like my +ideas are worthless. Um they they won't + + align:start position:0% +ideas are worthless. Um they they won't + + + align:start position:0% +ideas are worthless. Um they they won't +be able to get it out because they've + + align:start position:0% +be able to get it out because they've + + + align:start position:0% +be able to get it out because they've +then been they've then been cut short. + + align:start position:0% +then been they've then been cut short. + + + align:start position:0% +then been they've then been cut short. +Um so this you know some of this + + align:start position:0% +Um so this you know some of this + + + align:start position:0% +Um so this you know some of this +responsibility falls on what we might + + align:start position:0% +responsibility falls on what we might + + + align:start position:0% +responsibility falls on what we might +call the leader which I'll talk about + + align:start position:0% +call the leader which I'll talk about + + + align:start position:0% +call the leader which I'll talk about +later of of the of the group. Um but + + align:start position:0% +later of of the of the group. Um but + + + align:start position:0% +later of of the of the group. Um but +really it it's kind of a collective + + align:start position:0% +really it it's kind of a collective + + + align:start position:0% +really it it's kind of a collective +responsibility that everybody kind of um + + align:start position:0% +responsibility that everybody kind of um + + + align:start position:0% +responsibility that everybody kind of um +make sure that as someone is expressing + + align:start position:0% +make sure that as someone is expressing + + + align:start position:0% +make sure that as someone is expressing +an idea that it's maintained. Adding to + + align:start position:0% +an idea that it's maintained. Adding to + + + align:start position:0% +an idea that it's maintained. Adding to +that you know + + align:start position:0% +that you know + + + align:start position:0% +that you know +keep the keep the description of your + + align:start position:0% +keep the keep the description of your + + + align:start position:0% +keep the keep the description of your +idea short. Um you know if people are + + align:start position:0% +idea short. Um you know if people are + + + align:start position:0% +idea short. Um you know if people are +sitting here and it's like you've now + + align:start position:0% +sitting here and it's like you've now + + + align:start position:0% +sitting here and it's like you've now +hijacked the 30 minute brainstorming + + align:start position:0% +hijacked the 30 minute brainstorming + + + align:start position:0% +hijacked the 30 minute brainstorming +session with your one idea that took + + align:start position:0% +session with your one idea that took + + + align:start position:0% +session with your one idea that took +five minutes to explain. um that that + + align:start position:0% +five minutes to explain. um that that + + + align:start position:0% +five minutes to explain. um that that +can also hamper it, right? Part of it is + + align:start position:0% +can also hamper it, right? Part of it is + + + align:start position:0% +can also hamper it, right? Part of it is +not only don't interrupt people, but + + align:start position:0% +not only don't interrupt people, but + + + align:start position:0% +not only don't interrupt people, but +also make sure that when you are + + align:start position:0% +also make sure that when you are + + + align:start position:0% +also make sure that when you are +contributing, you are allowing for other + + align:start position:0% +contributing, you are allowing for other + + + align:start position:0% +contributing, you are allowing for other +people to contribute as well. Um + + align:start position:0% +people to contribute as well. Um + + + align:start position:0% +people to contribute as well. Um +something that maybe is not considered + + align:start position:0% +something that maybe is not considered + + + align:start position:0% +something that maybe is not considered +as much. Um for the organization, + + align:start position:0% +as much. Um for the organization, + + + align:start position:0% +as much. Um for the organization, +designate a leader. I hate that term, + + align:start position:0% +designate a leader. I hate that term, + + + align:start position:0% +designate a leader. I hate that term, +but that's what he used in the book. Um + + align:start position:0% +but that's what he used in the book. Um + + + align:start position:0% +but that's what he used in the book. Um +I I tend to use the term clerk, which is + + align:start position:0% +I I tend to use the term clerk, which is + + + align:start position:0% +I I tend to use the term clerk, which is +kind of a quaker idea, which I I kind of + + align:start position:0% +kind of a quaker idea, which I I kind of + + + align:start position:0% +kind of a quaker idea, which I I kind of +grab on to. A clerk, you know, being + + align:start position:0% +grab on to. A clerk, you know, being + + + align:start position:0% +grab on to. A clerk, you know, being +more of a facilitator than an actual + + align:start position:0% +more of a facilitator than an actual + + + align:start position:0% +more of a facilitator than an actual +leader. Um you know, leader suggests, + + align:start position:0% +leader. Um you know, leader suggests, + + + align:start position:0% +leader. Um you know, leader suggests, +you know, boss. It's always not great + + align:start position:0% +you know, boss. It's always not great + + + align:start position:0% +you know, boss. It's always not great +for a for a, you know, everyone's even + + align:start position:0% +for a for a, you know, everyone's even + + + align:start position:0% +for a for a, you know, everyone's even +sort of brainstorming session. Um, and + + align:start position:0% +sort of brainstorming session. Um, and + + + align:start position:0% +sort of brainstorming session. Um, and +then of course the secretary or as he + + align:start position:0% +then of course the secretary or as he + + + align:start position:0% +then of course the secretary or as he +calls it an associate theater. Um, you + + align:start position:0% +calls it an associate theater. Um, you + + + align:start position:0% +calls it an associate theater. Um, you +know, this is someone who who writes + + align:start position:0% +know, this is someone who who writes + + + align:start position:0% +know, this is someone who who writes +stuff down. You know, there's some of + + align:start position:0% +stuff down. You know, there's some of + + + align:start position:0% +stuff down. You know, there's some of +that that good old fashioned hierarchy + + align:start position:0% +that that good old fashioned hierarchy + + + align:start position:0% +that that good old fashioned hierarchy +going on in this in this text, but um + + align:start position:0% +going on in this in this text, but um + + + align:start position:0% +going on in this in this text, but um +but you know, obviously we'll talk a + + align:start position:0% +but you know, obviously we'll talk a + + + align:start position:0% +but you know, obviously we'll talk a +little bit more about what the roles of + + align:start position:0% +little bit more about what the roles of + + + align:start position:0% +little bit more about what the roles of +these people are, but but having those + + align:start position:0% +these people are, but but having those + + + align:start position:0% +these people are, but but having those +those roles uh defined early is + + align:start position:0% +those roles uh defined early is + + + align:start position:0% +those roles uh defined early is +important. Um, + + align:start position:0% +important. Um, + + + align:start position:0% +important. Um, +and then this is this is something to + + align:start position:0% +and then this is this is something to + + + align:start position:0% +and then this is this is something to +talk about a bit explaining the process + + align:start position:0% +talk about a bit explaining the process + + + align:start position:0% +talk about a bit explaining the process +and the principal question at the start + + align:start position:0% +and the principal question at the start + + + align:start position:0% +and the principal question at the start +of the session. Um, you know, I don't + + align:start position:0% +of the session. Um, you know, I don't + + + align:start position:0% +of the session. Um, you know, I don't +know how how many of you had heard of + + align:start position:0% +know how how many of you had heard of + + + align:start position:0% +know how how many of you had heard of +these four principles of brainstorming + + align:start position:0% +these four principles of brainstorming + + + align:start position:0% +these four principles of brainstorming +explicitly prior to reading this text? + + align:start position:0% +explicitly prior to reading this text? + + + align:start position:0% +explicitly prior to reading this text? +Anybody? Oh, well, + + align:start position:0% +Anybody? Oh, well, + + + align:start position:0% +Anybody? Oh, well, +I know you heard from me. But, um, but + + align:start position:0% +I know you heard from me. But, um, but + + + align:start position:0% +I know you heard from me. But, um, but +yeah, the um, you know, the process is + + align:start position:0% +yeah, the um, you know, the process is + + + align:start position:0% +yeah, the um, you know, the process is +something that it needs to be clear + + align:start position:0% +something that it needs to be clear + + + align:start position:0% +something that it needs to be clear +otherwise people won't remember to do. + + align:start position:0% +otherwise people won't remember to do. + + + align:start position:0% +otherwise people won't remember to do. +And you'll see when we do the exercise, + + align:start position:0% +And you'll see when we do the exercise, + + + align:start position:0% +And you'll see when we do the exercise, +it's it's even hard sometimes to curb + + align:start position:0% +it's it's even hard sometimes to curb + + + align:start position:0% +it's it's even hard sometimes to curb +your criticism. You know, it's it's just + + align:start position:0% +your criticism. You know, it's it's just + + + align:start position:0% +your criticism. You know, it's it's just +when especially when you're comfortable + + align:start position:0% +when especially when you're comfortable + + + align:start position:0% +when especially when you're comfortable +with people and you may not mean it in a + + align:start position:0% +with people and you may not mean it in a + + + align:start position:0% +with people and you may not mean it in a +malicious way. You may not mean it in a + + align:start position:0% +malicious way. You may not mean it in a + + + align:start position:0% +malicious way. You may not mean it in a +way to kind of uh you know stop the + + align:start position:0% +way to kind of uh you know stop the + + + align:start position:0% +way to kind of uh you know stop the +brainstorming session, but you just be + + align:start position:0% +brainstorming session, but you just be + + + align:start position:0% +brainstorming session, but you just be +like, "Oh, that's nuts." You know, we're + + align:start position:0% +like, "Oh, that's nuts." You know, we're + + + align:start position:0% +like, "Oh, that's nuts." You know, we're +laughing and everybody's having a good + + align:start position:0% +laughing and everybody's having a good + + + align:start position:0% +laughing and everybody's having a good +time. And then you kind of like think + + align:start position:0% +time. And then you kind of like think + + + align:start position:0% +time. And then you kind of like think +back and like wait, you know, that was + + align:start position:0% +back and like wait, you know, that was + + + align:start position:0% +back and like wait, you know, that was +me passing judgment on an idea and + + align:start position:0% +me passing judgment on an idea and + + + align:start position:0% +me passing judgment on an idea and +possibly inhibiting the kind of the kind + + align:start position:0% +possibly inhibiting the kind of the kind + + + align:start position:0% +possibly inhibiting the kind of the kind +of ideation that we're trying to get + + align:start position:0% +of ideation that we're trying to get + + + align:start position:0% +of ideation that we're trying to get +across. So, um explaining the process at + + align:start position:0% +across. So, um explaining the process at + + + align:start position:0% +across. So, um explaining the process at +the beginning regardless of the group is + + align:start position:0% +the beginning regardless of the group is + + + align:start position:0% +the beginning regardless of the group is +really important and that is usually + + align:start position:0% +really important and that is usually + + + align:start position:0% +really important and that is usually +responsibility that falls on the leader + + align:start position:0% +responsibility that falls on the leader + + + align:start position:0% +responsibility that falls on the leader +or the secretary, whoever is organizing + + align:start position:0% +or the secretary, whoever is organizing + + + align:start position:0% +or the secretary, whoever is organizing +the session, right? They even suggest in + + align:start position:0% +the session, right? They even suggest in + + + align:start position:0% +the session, right? They even suggest in +the text have it posted have the four + + align:start position:0% +the text have it posted have the four + + + align:start position:0% +the text have it posted have the four +principles up so that everybody can kind + + align:start position:0% +principles up so that everybody can kind + + + align:start position:0% +principles up so that everybody can kind +of remind themselves through the process + + align:start position:0% +of remind themselves through the process + + + align:start position:0% +of remind themselves through the process +what these four principles are. Um but + + align:start position:0% +what these four principles are. Um but + + + align:start position:0% +what these four principles are. Um but +explaining the process is really + + align:start position:0% +explaining the process is really + + + align:start position:0% +explaining the process is really +important and this this is I can't even + + align:start position:0% +important and this this is I can't even + + + align:start position:0% +important and this this is I can't even +this is so important. Um having the + + align:start position:0% +this is so important. Um having the + + + align:start position:0% +this is so important. Um having the +principal question and the goal of the + + align:start position:0% +principal question and the goal of the + + + align:start position:0% +principal question and the goal of the +brainstorming session clear at the start + + align:start position:0% +brainstorming session clear at the start + + + align:start position:0% +brainstorming session clear at the start +um you know obviously it's it's this is + + align:start position:0% +um you know obviously it's it's this is + + + align:start position:0% +um you know obviously it's it's this is +encouraging freewheeling. It's + + align:start position:0% +encouraging freewheeling. It's + + + align:start position:0% +encouraging freewheeling. It's +encouraging free thought. that's + + align:start position:0% +encouraging free thought. that's + + + align:start position:0% +encouraging free thought. that's +encouraging this all kind of you know + + align:start position:0% +encouraging this all kind of you know + + + align:start position:0% +encouraging this all kind of you know +wide openen creativity and yet at the + + align:start position:0% +wide openen creativity and yet at the + + + align:start position:0% +wide openen creativity and yet at the +same time if you do that in an unbounded + + align:start position:0% +same time if you do that in an unbounded + + + align:start position:0% +same time if you do that in an unbounded +sort of way you might end up with things + + align:start position:0% +sort of way you might end up with things + + + align:start position:0% +sort of way you might end up with things +that that really in the end you don't + + align:start position:0% +that that really in the end you don't + + + align:start position:0% +that that really in the end you don't +have too many useful ideas you've got + + align:start position:0% +have too many useful ideas you've got + + + align:start position:0% +have too many useful ideas you've got +useful ideas for something else not for + + align:start position:0% +useful ideas for something else not for + + + align:start position:0% +useful ideas for something else not for +the actual creative problem that you + + align:start position:0% +the actual creative problem that you + + + align:start position:0% +the actual creative problem that you +have. So, I mean, you take it from an ad + + align:start position:0% +have. So, I mean, you take it from an ad + + + align:start position:0% +have. So, I mean, you take it from an ad +ad concept, you know, so you've got a + + align:start position:0% +ad concept, you know, so you've got a + + + align:start position:0% +ad concept, you know, so you've got a +vodka company that's like, "Oh, we need + + align:start position:0% +vodka company that's like, "Oh, we need + + + align:start position:0% +vodka company that's like, "Oh, we need +we need an advertisement for our, you + + align:start position:0% +we need an advertisement for our, you + + + align:start position:0% +we need an advertisement for our, you +know, awesome vodka or whatever." And + + align:start position:0% +know, awesome vodka or whatever." And + + + align:start position:0% +know, awesome vodka or whatever." And +so, you're like, "All right, well, we + + align:start position:0% +so, you're like, "All right, well, we + + + align:start position:0% +so, you're like, "All right, well, we +have a brainstorm session." Then a bunch + + align:start position:0% +have a brainstorm session." Then a bunch + + + align:start position:0% +have a brainstorm session." Then a bunch +of people come up with ideas. Now, + + align:start position:0% +of people come up with ideas. Now, + + + align:start position:0% +of people come up with ideas. Now, +you're selling dryers. Um, because it + + align:start position:0% +you're selling dryers. Um, because it + + + align:start position:0% +you're selling dryers. Um, because it +was wide open, right? And it's like, + + align:start position:0% +was wide open, right? And it's like, + + + align:start position:0% +was wide open, right? And it's like, +"Oh, we've got these great ad ideas for + + align:start position:0% +"Oh, we've got these great ad ideas for + + + align:start position:0% +"Oh, we've got these great ad ideas for +dryers, but they're just really, really + + align:start position:0% +dryers, but they're just really, really + + + align:start position:0% +dryers, but they're just really, really +not going to work." You know, bringing + + align:start position:0% +not going to work." You know, bringing + + + align:start position:0% +not going to work." You know, bringing +it back to a video game contest. um you + + align:start position:0% +it back to a video game contest. um you + + + align:start position:0% +it back to a video game contest. um you +know, you've got a contract with a + + align:start position:0% +know, you've got a contract with a + + + align:start position:0% +know, you've got a contract with a +producer to make a first-person shooter, + + align:start position:0% +producer to make a first-person shooter, + + + align:start position:0% +producer to make a first-person shooter, +and in your brainstorming session, + + align:start position:0% +and in your brainstorming session, + + + align:start position:0% +and in your brainstorming session, +you've designed um a cool cute + + align:start position:0% +you've designed um a cool cute + + + align:start position:0% +you've designed um a cool cute +platformer. Um neat, but that's not + + align:start position:0% +platformer. Um neat, but that's not + + + align:start position:0% +platformer. Um neat, but that's not +where the money's coming from, right? + + align:start position:0% +where the money's coming from, right? + + + align:start position:0% +where the money's coming from, right? +So, so bounding the brainstorm session + + align:start position:0% +So, so bounding the brainstorm session + + + align:start position:0% +So, so bounding the brainstorm session +is important, too. And and you'll kind + + align:start position:0% +is important, too. And and you'll kind + + + align:start position:0% +is important, too. And and you'll kind +of see that in the exercises that we do + + align:start position:0% +of see that in the exercises that we do + + + align:start position:0% +of see that in the exercises that we do +today, how it's important to to bound + + align:start position:0% +today, how it's important to to bound + + + align:start position:0% +today, how it's important to to bound +that. Um + + align:start position:0% + + + + align:start position:0% + +yes. + + align:start position:0% +yes. + + + align:start position:0% +yes. +Oh, and write down everything. Yeah, + + align:start position:0% +Oh, and write down everything. Yeah, + + + align:start position:0% +Oh, and write down everything. Yeah, +sorry, I forgot about that. This is an + + align:start position:0% +sorry, I forgot about that. This is an + + + align:start position:0% +sorry, I forgot about that. This is an +important uh important question. Uh + + align:start position:0% +important uh important question. Uh + + + align:start position:0% +important uh important question. Uh +important point um you know you this + + align:start position:0% +important point um you know you this + + + align:start position:0% +important point um you know you this +happens to all of us but you have this + + align:start position:0% +happens to all of us but you have this + + + align:start position:0% +happens to all of us but you have this +great idea and then you don't write it + + align:start position:0% +great idea and then you don't write it + + + align:start position:0% +great idea and then you don't write it +down and then you you go to bed and then + + align:start position:0% +down and then you you go to bed and then + + + align:start position:0% +down and then you you go to bed and then +the next day you're like oh I had this + + align:start position:0% +the next day you're like oh I had this + + + align:start position:0% +the next day you're like oh I had this +great idea great idea and you can't + + align:start position:0% +great idea great idea and you can't + + + align:start position:0% +great idea great idea and you can't +remember it right and so um writing down + + align:start position:0% +remember it right and so um writing down + + + align:start position:0% +remember it right and so um writing down +everything is absolutely essential. + + align:start position:0% +everything is absolutely essential. + + + align:start position:0% +everything is absolutely essential. +You'll never you know you'd be amazed + + align:start position:0% +You'll never you know you'd be amazed + + + align:start position:0% +You'll never you know you'd be amazed +the number of times that you know a week + + align:start position:0% +the number of times that you know a week + + + align:start position:0% +the number of times that you know a week +later you're like oh we could put these + + align:start position:0% +later you're like oh we could put these + + + align:start position:0% +later you're like oh we could put these +two ideas together um as long as you can + + align:start position:0% +two ideas together um as long as you can + + + align:start position:0% +two ideas together um as long as you can +remember what those ideas were. Um, and + + align:start position:0% +remember what those ideas were. Um, and + + + align:start position:0% +remember what those ideas were. Um, and +so what you think, you know, it's hard + + align:start position:0% +so what you think, you know, it's hard + + + align:start position:0% +so what you think, you know, it's hard +to not mentally pass judgment on things + + align:start position:0% +to not mentally pass judgment on things + + + align:start position:0% +to not mentally pass judgment on things +during the brainstorm session. And what + + align:start position:0% +during the brainstorm session. And what + + + align:start position:0% +during the brainstorm session. And what +you think might be great now may a week + + align:start position:0% +you think might be great now may a week + + + align:start position:0% +you think might be great now may a week +later not be as great and what you + + align:start position:0% +later not be as great and what you + + + align:start position:0% +later not be as great and what you +didn't think, you know, will be. And so + + align:start position:0% +didn't think, you know, will be. And so + + + align:start position:0% +didn't think, you know, will be. And so +making sure to have everything written + + align:start position:0% +making sure to have everything written + + + align:start position:0% +making sure to have everything written +down is really important. And and they + + align:start position:0% +down is really important. And and they + + + align:start position:0% +down is really important. And and they +even suggest, you know, having um two + + align:start position:0% +even suggest, you know, having um two + + + align:start position:0% +even suggest, you know, having um two +secretaries if you need if you've got a + + align:start position:0% +secretaries if you need if you've got a + + + align:start position:0% +secretaries if you need if you've got a +large group or lots of ideas and they're + + align:start position:0% +large group or lots of ideas and they're + + + align:start position:0% +large group or lots of ideas and they're +each writing every other one um can be + + align:start position:0% +each writing every other one um can be + + + align:start position:0% +each writing every other one um can be +helpful to make sure that you get + + align:start position:0% +helpful to make sure that you get + + + align:start position:0% +helpful to make sure that you get +everything right so that you get + + align:start position:0% +everything right so that you get + + + align:start position:0% +everything right so that you get +everything. So um + + align:start position:0% +everything. So um + + + align:start position:0% +everything. So um +next is the question of what sort of + + align:start position:0% +next is the question of what sort of + + + align:start position:0% +next is the question of what sort of +problems are suitable to a brainstorming + + align:start position:0% +problems are suitable to a brainstorming + + + align:start position:0% +problems are suitable to a brainstorming +session. Uh the great example that Alex + + align:start position:0% +session. Uh the great example that Alex + + + align:start position:0% +session. Uh the great example that Alex +Osborne gives is um setting up a + + align:start position:0% +Osborne gives is um setting up a + + + align:start position:0% +Osborne gives is um setting up a +brainstorm session on whether or not to + + align:start position:0% +brainstorm session on whether or not to + + + align:start position:0% +brainstorm session on whether or not to +get married um is not a particularly + + align:start position:0% +get married um is not a particularly + + + align:start position:0% +get married um is not a particularly +suitable question. I that was sort of an + + align:start position:0% +suitable question. I that was sort of an + + + align:start position:0% +suitable question. I that was sort of an +interesting uh interesting concept. He's + + align:start position:0% +interesting uh interesting concept. He's + + + align:start position:0% +interesting uh interesting concept. He's +like well to decide to get married you + + align:start position:0% +like well to decide to get married you + + + align:start position:0% +like well to decide to get married you +you apparently list the pros and cons. + + align:start position:0% +you apparently list the pros and cons. + + + align:start position:0% +you apparently list the pros and cons. +That's not exactly the process I went + + align:start position:0% +That's not exactly the process I went + + + align:start position:0% +That's not exactly the process I went +through before I got married. I was like + + align:start position:0% +through before I got married. I was like + + + align:start position:0% +through before I got married. I was like +well honey I'm going to have to write + + align:start position:0% +well honey I'm going to have to write + + + align:start position:0% +well honey I'm going to have to write +this down. Um + + align:start position:0% +this down. Um + + + align:start position:0% +this down. Um +but fair enough that that wasn't the + + align:start position:0% +but fair enough that that wasn't the + + + align:start position:0% +but fair enough that that wasn't the +suggestion that he came up with. And he + + align:start position:0% +suggestion that he came up with. And he + + + align:start position:0% +suggestion that he came up with. And he +has a good point, right? I mean it's the + + align:start position:0% +has a good point, right? I mean it's the + + + align:start position:0% +has a good point, right? I mean it's the +question of whether or not to get + + align:start position:0% +question of whether or not to get + + + align:start position:0% +question of whether or not to get +married is a judgment call. Um it is not + + align:start position:0% +married is a judgment call. Um it is not + + + align:start position:0% +married is a judgment call. Um it is not +a creative uh ideation process. And so + + align:start position:0% +a creative uh ideation process. And so + + + align:start position:0% +a creative uh ideation process. And so +that's not a particularly useful um kind + + align:start position:0% +that's not a particularly useful um kind + + + align:start position:0% +that's not a particularly useful um kind +of uh problem that's suitable to the + + align:start position:0% +of uh problem that's suitable to the + + + align:start position:0% +of uh problem that's suitable to the +brainstorming process. Um you know, you + + align:start position:0% +brainstorming process. Um you know, you + + + align:start position:0% +brainstorming process. Um you know, you +want you want a uh you want a problem + + align:start position:0% +want you want a uh you want a problem + + + align:start position:0% +want you want a uh you want a problem +that is going to be benefited by having + + align:start position:0% +that is going to be benefited by having + + + align:start position:0% +that is going to be benefited by having +a large uh a large selection, a large + + align:start position:0% +a large uh a large selection, a large + + + align:start position:0% +a large uh a large selection, a large +corpus of ideas. And so those are the + + align:start position:0% +corpus of ideas. And so those are the + + + align:start position:0% +corpus of ideas. And so those are the +kind of problems that are more more + + align:start position:0% +kind of problems that are more more + + + align:start position:0% +kind of problems that are more more +useful. And you know, you'll see when we + + align:start position:0% +useful. And you know, you'll see when we + + + align:start position:0% +useful. And you know, you'll see when we +do our example exercise what some of + + align:start position:0% +do our example exercise what some of + + + align:start position:0% +do our example exercise what some of +those might be. Um I also kind of put + + align:start position:0% +those might be. Um I also kind of put + + + align:start position:0% +those might be. Um I also kind of put +here that um you know having a clear + + align:start position:0% +here that um you know having a clear + + + align:start position:0% +here that um you know having a clear +definition of the aim is really + + align:start position:0% +definition of the aim is really + + + align:start position:0% +definition of the aim is really +essential. It's sort of what we talked + + align:start position:0% +essential. It's sort of what we talked + + + align:start position:0% +essential. It's sort of what we talked +about before. Um you need to make sure + + align:start position:0% +about before. Um you need to make sure + + + align:start position:0% +about before. Um you need to make sure +that everybody understands and + + align:start position:0% +that everybody understands and + + + align:start position:0% +that everybody understands and +everybody's on the same page. Otherwise + + align:start position:0% +everybody's on the same page. Otherwise + + + align:start position:0% +everybody's on the same page. Otherwise +you end up with stuff that um that might + + align:start position:0% +you end up with stuff that um that might + + + align:start position:0% +you end up with stuff that um that might +be useful for something else but not + + align:start position:0% +be useful for something else but not + + + align:start position:0% +be useful for something else but not +useful for what you're you're + + align:start position:0% +useful for what you're you're + + + align:start position:0% +useful for what you're you're +particularly trying to do. Um and so + + align:start position:0% +particularly trying to do. Um and so + + + align:start position:0% +particularly trying to do. Um and so +making that clear for everybody is + + align:start position:0% +making that clear for everybody is + + + align:start position:0% +making that clear for everybody is +really important. Um, keeping the + + align:start position:0% +really important. Um, keeping the + + + align:start position:0% +really important. Um, keeping the +problem as simple as possible, um, you + + align:start position:0% +problem as simple as possible, um, you + + + align:start position:0% +problem as simple as possible, um, you +know, is also really important. Trying + + align:start position:0% +know, is also really important. Trying + + + align:start position:0% +know, is also really important. Trying +to keep simple language, uh, for the + + align:start position:0% +to keep simple language, uh, for the + + + align:start position:0% +to keep simple language, uh, for the +problem. Uh, keep it, you know, keep it + + align:start position:0% +problem. Uh, keep it, you know, keep it + + + align:start position:0% +problem. Uh, keep it, you know, keep it +constrained in a way that that, um, is + + align:start position:0% +constrained in a way that that, um, is + + + align:start position:0% +constrained in a way that that, um, is +simple enough so that people can kind of + + align:start position:0% +simple enough so that people can kind of + + + align:start position:0% +simple enough so that people can kind of +work on it as opposed to just feeling + + align:start position:0% +work on it as opposed to just feeling + + + align:start position:0% +work on it as opposed to just feeling +limited by it. Um, if that makes any + + align:start position:0% +limited by it. Um, if that makes any + + + align:start position:0% +limited by it. Um, if that makes any +sense. You know, something is overly + + align:start position:0% +sense. You know, something is overly + + + align:start position:0% +sense. You know, something is overly +complicated and overly constrained. Um, + + align:start position:0% +complicated and overly constrained. Um, + + + align:start position:0% +complicated and overly constrained. Um, +then it becomes a well, how do I fit + + align:start position:0% +then it becomes a well, how do I fit + + + align:start position:0% +then it becomes a well, how do I fit +everything into this? You know, how do I + + align:start position:0% +everything into this? You know, how do I + + + align:start position:0% +everything into this? You know, how do I +match every single one of these things? + + align:start position:0% +match every single one of these things? + + + align:start position:0% +match every single one of these things? +If it's simpler, then it's a little bit + + align:start position:0% +If it's simpler, then it's a little bit + + + align:start position:0% +If it's simpler, then it's a little bit +easier to kind of work on and kind of be + + align:start position:0% +easier to kind of work on and kind of be + + + align:start position:0% +easier to kind of work on and kind of be +creative. So, keeping problems simple. + + align:start position:0% +creative. So, keeping problems simple. + + + align:start position:0% +creative. So, keeping problems simple. +Um, which isn't to say that complex + + align:start position:0% +Um, which isn't to say that complex + + + align:start position:0% +Um, which isn't to say that complex +problems couldn't be dealt with, but + + align:start position:0% +problems couldn't be dealt with, but + + + align:start position:0% +problems couldn't be dealt with, but +just divide this divide them into sub + + align:start position:0% +just divide this divide them into sub + + + align:start position:0% +just divide this divide them into sub +problems, right? Divide them into little + + align:start position:0% +problems, right? Divide them into little + + + align:start position:0% +problems, right? Divide them into little +little sections. So, there might be + + align:start position:0% +little sections. So, there might be + + + align:start position:0% +little sections. So, there might be +something like, you know, how could we + + align:start position:0% +something like, you know, how could we + + + align:start position:0% +something like, you know, how could we +deal with the UI? Um, you know, how + + align:start position:0% +deal with the UI? Um, you know, how + + + align:start position:0% +deal with the UI? Um, you know, how +could it look in this uh in this game, + + align:start position:0% +could it look in this uh in this game, + + + align:start position:0% +could it look in this uh in this game, +you know? So, rather than say, well, how + + align:start position:0% +you know? So, rather than say, well, how + + + align:start position:0% +you know? So, rather than say, well, how +are we going to design our first person + + align:start position:0% +are we going to design our first person + + + align:start position:0% +are we going to design our first person +shooter? You've got a brainstorming + + align:start position:0% +shooter? You've got a brainstorming + + + align:start position:0% +shooter? You've got a brainstorming +session about what the UI could look + + align:start position:0% +session about what the UI could look + + + align:start position:0% +session about what the UI could look +like for the first person shooter. + + align:start position:0% +like for the first person shooter. + + + align:start position:0% +like for the first person shooter. +you've got maybe a brainstorming session + + align:start position:0% +you've got maybe a brainstorming session + + + align:start position:0% +you've got maybe a brainstorming session +for um you know what the fiction for + + align:start position:0% +for um you know what the fiction for + + + align:start position:0% +for um you know what the fiction for +this first person shooter might be. + + align:start position:0% +this first person shooter might be. + + + align:start position:0% +this first person shooter might be. +You're dividing it into sub problems + + align:start position:0% +You're dividing it into sub problems + + + align:start position:0% +You're dividing it into sub problems +rather than having it be this gigantic + + align:start position:0% +rather than having it be this gigantic + + + align:start position:0% +rather than having it be this gigantic +you know model of of a thing. And you + + align:start position:0% +you know model of of a thing. And you + + + align:start position:0% +you know model of of a thing. And you +can see how that would be a problem, + + align:start position:0% +can see how that would be a problem, + + + align:start position:0% +can see how that would be a problem, +right? Because if you just brainstorm on + + align:start position:0% +right? Because if you just brainstorm on + + + align:start position:0% +right? Because if you just brainstorm on +what's our first person shooter going to + + align:start position:0% +what's our first person shooter going to + + + align:start position:0% +what's our first person shooter going to +be, you're going to get ideas about the + + align:start position:0% +be, you're going to get ideas about the + + + align:start position:0% +be, you're going to get ideas about the +UI. You're going to get ideas about the + + align:start position:0% +UI. You're going to get ideas about the + + + align:start position:0% +UI. You're going to get ideas about the +fiction. You're going to get ideas about + + align:start position:0% +fiction. You're going to get ideas about + + + align:start position:0% +fiction. You're going to get ideas about +what sort of guns you should use or what + + align:start position:0% +what sort of guns you should use or what + + + align:start position:0% +what sort of guns you should use or what +they should sound like. And it'll just + + align:start position:0% +they should sound like. And it'll just + + + align:start position:0% +they should sound like. And it'll just +be lots of interesting ideas but we get + + align:start position:0% +be lots of interesting ideas but we get + + + align:start position:0% +be lots of interesting ideas but we get +all over the place. + + align:start position:0% +all over the place. + + + align:start position:0% +all over the place. +uh and yeah uh problems should be + + align:start position:0% +uh and yeah uh problems should be + + + align:start position:0% +uh and yeah uh problems should be +clearly and simply articulated. I think + + align:start position:0% +clearly and simply articulated. I think + + + align:start position:0% +clearly and simply articulated. I think +that's what I sort of said by should be + + align:start position:0% +that's what I sort of said by should be + + + align:start position:0% +that's what I sort of said by should be +simple just you know make sure that + + align:start position:0% +simple just you know make sure that + + + align:start position:0% +simple just you know make sure that +they're articulated in the simple way. + + align:start position:0% +they're articulated in the simple way. + + + align:start position:0% +they're articulated in the simple way. +Sometimes you can have a simple problem + + align:start position:0% +Sometimes you can have a simple problem + + + align:start position:0% +Sometimes you can have a simple problem +that's not articulated particularly + + align:start position:0% +that's not articulated particularly + + + align:start position:0% +that's not articulated particularly +clearly. Um so it's just something um + + align:start position:0% +clearly. Um so it's just something um + + + align:start position:0% +clearly. Um so it's just something um +responsibilities of the leader clerk + + align:start position:0% +responsibilities of the leader clerk + + + align:start position:0% +responsibilities of the leader clerk +whatever um + + align:start position:0% +whatever um + + + align:start position:0% +whatever um +the first being uh to understand and + + align:start position:0% +the first being uh to understand and + + + align:start position:0% +the first being uh to understand and +explain the problem and the aim of the + + align:start position:0% +explain the problem and the aim of the + + + align:start position:0% +explain the problem and the aim of the +brainstorm session. I mean a lot of + + align:start position:0% +brainstorm session. I mean a lot of + + + align:start position:0% +brainstorm session. I mean a lot of +times people uh maybe will write a memo + + align:start position:0% +times people uh maybe will write a memo + + + align:start position:0% +times people uh maybe will write a memo +beforehand um you know as the + + align:start position:0% +beforehand um you know as the + + + align:start position:0% +beforehand um you know as the +facilitator of the of the thing as the + + align:start position:0% +facilitator of the of the thing as the + + + align:start position:0% +facilitator of the of the thing as the +person who perhaps wants to see the + + align:start position:0% +person who perhaps wants to see the + + + align:start position:0% +person who perhaps wants to see the +brainstorm be a success uh the most + + align:start position:0% +brainstorm be a success uh the most + + + align:start position:0% +brainstorm be a success uh the most +maybe um you know having a clear + + align:start position:0% +maybe um you know having a clear + + + align:start position:0% +maybe um you know having a clear +understanding of the problem and + + align:start position:0% +understanding of the problem and + + + align:start position:0% +understanding of the problem and +explaining that to the group is an + + align:start position:0% +explaining that to the group is an + + + align:start position:0% +explaining that to the group is an +important job for the leader um I use + + align:start position:0% +important job for the leader um I use + + + align:start position:0% +important job for the leader um I use +this term facilitating the session uh + + align:start position:0% +this term facilitating the session uh + + + align:start position:0% +this term facilitating the session uh +encouraging ideiation discouraging + + align:start position:0% +encouraging ideiation discouraging + + + align:start position:0% +encouraging ideiation discouraging +criticism you're kind of the watch guard + + align:start position:0% +criticism you're kind of the watch guard + + + align:start position:0% +criticism you're kind of the watch guard +for the process not necessarily um you + + align:start position:0% +for the process not necessarily um you + + + align:start position:0% +for the process not necessarily um you +can sometimes be a contributor and a + + align:start position:0% +can sometimes be a contributor and a + + + align:start position:0% +can sometimes be a contributor and a +watchdog for the process. But most + + align:start position:0% +watchdog for the process. But most + + + align:start position:0% +watchdog for the process. But most +importantly is that you are a watchdog + + align:start position:0% +importantly is that you are a watchdog + + + align:start position:0% +importantly is that you are a watchdog +for the process. Um it's you'll you'll + + align:start position:0% +for the process. Um it's you'll you'll + + + align:start position:0% +for the process. Um it's you'll you'll +see as we do it, it's just so easy to + + align:start position:0% +see as we do it, it's just so easy to + + + align:start position:0% +see as we do it, it's just so easy to +kind of slip into these conversational + + align:start position:0% +kind of slip into these conversational + + + align:start position:0% +kind of slip into these conversational +habits that are contrary to + + align:start position:0% +habits that are contrary to + + + align:start position:0% +habits that are contrary to +brainstorming uh brainstorming process + + align:start position:0% +brainstorming uh brainstorming process + + + align:start position:0% +brainstorming uh brainstorming process +and uh and so having someone who's + + align:start position:0% +and uh and so having someone who's + + + align:start position:0% +and uh and so having someone who's +constantly like making sure don't + + align:start position:0% +constantly like making sure don't + + + align:start position:0% +constantly like making sure don't +criticize encouraging people like oh I + + align:start position:0% +criticize encouraging people like oh I + + + align:start position:0% +criticize encouraging people like oh I +haven't heard from this person. Do you + + align:start position:0% +haven't heard from this person. Do you + + + align:start position:0% +haven't heard from this person. Do you +have any ideas? You know, even kind of + + align:start position:0% +have any ideas? You know, even kind of + + + align:start position:0% +have any ideas? You know, even kind of +pulling people out is important. Um and + + align:start position:0% +pulling people out is important. Um and + + + align:start position:0% +pulling people out is important. Um and +that comes to that ensuring that no + + align:start position:0% +that comes to that ensuring that no + + + align:start position:0% +that comes to that ensuring that no +voices are lost during the discussion, + + align:start position:0% +voices are lost during the discussion, + + + align:start position:0% +voices are lost during the discussion, +right? I mean we had that abbleist + + align:start position:0% +right? I mean we had that abbleist + + + align:start position:0% +right? I mean we had that abbleist +member who had 15 ideas that he wrote + + align:start position:0% +member who had 15 ideas that he wrote + + + align:start position:0% +member who had 15 ideas that he wrote +down and he's like they're worthless. + + align:start position:0% +down and he's like they're worthless. + + + align:start position:0% +down and he's like they're worthless. +Well, in some ways it's the part of the + + align:start position:0% +Well, in some ways it's the part of the + + + align:start position:0% +Well, in some ways it's the part of the +leader either during the session or + + align:start position:0% +leader either during the session or + + + align:start position:0% +leader either during the session or +after the session to try to encourage, + + align:start position:0% +after the session to try to encourage, + + + align:start position:0% +after the session to try to encourage, +you know, those able members to + + align:start position:0% +you know, those able members to + + + align:start position:0% +you know, those able members to +contribute. Um yeah, I mean it's some of + + align:start position:0% +contribute. Um yeah, I mean it's some of + + + align:start position:0% +contribute. Um yeah, I mean it's some of +the most crackpot ideas become the best + + align:start position:0% +the most crackpot ideas become the best + + + align:start position:0% +the most crackpot ideas become the best +ones. So you really want to make sure + + align:start position:0% +ones. So you really want to make sure + + + align:start position:0% +ones. So you really want to make sure +every voice is heard. Um and then + + align:start position:0% +every voice is heard. Um and then + + + align:start position:0% +every voice is heard. Um and then +encouraging the synthesis, encouraging + + align:start position:0% +encouraging the synthesis, encouraging + + + align:start position:0% +encouraging the synthesis, encouraging +people to kind of riff on other ideas. + + align:start position:0% +people to kind of riff on other ideas. + + + align:start position:0% +people to kind of riff on other ideas. +Um you know, trying to find ways for + + align:start position:0% +Um you know, trying to find ways for + + + align:start position:0% +Um you know, trying to find ways for +people to build on each other even + + align:start position:0% +people to build on each other even + + + align:start position:0% +people to build on each other even +offering synthesis towards a direction. + + align:start position:0% +offering synthesis towards a direction. + + + align:start position:0% +offering synthesis towards a direction. +So maybe you have a couple ideas you're + + align:start position:0% +So maybe you have a couple ideas you're + + + align:start position:0% +So maybe you have a couple ideas you're +like, "Oh, like you know, one and 10 are + + align:start position:0% +like, "Oh, like you know, one and 10 are + + + align:start position:0% +like, "Oh, like you know, one and 10 are +kind of similar, but like you know, are + + align:start position:0% +kind of similar, but like you know, are + + + align:start position:0% +kind of similar, but like you know, are +there any ways we can combine this?" And + + align:start position:0% +there any ways we can combine this?" And + + + align:start position:0% +there any ways we can combine this?" And +like, "Yeah, we could, you know, give + + align:start position:0% +like, "Yeah, we could, you know, give + + + align:start position:0% +like, "Yeah, we could, you know, give +him a helmet." Awesome. + + align:start position:0% +him a helmet." Awesome. + + + align:start position:0% +him a helmet." Awesome. +So on so forth. I don't know what what + + align:start position:0% +So on so forth. I don't know what what + + + align:start position:0% +So on so forth. I don't know what what +two things can combine to get a helmet, + + align:start position:0% +two things can combine to get a helmet, + + + align:start position:0% +two things can combine to get a helmet, +but can't get shot in the head. How + + align:start position:0% +but can't get shot in the head. How + + + align:start position:0% +but can't get shot in the head. How +about a helmet? All right. Um, so + + align:start position:0% +about a helmet? All right. Um, so + + + align:start position:0% +about a helmet? All right. Um, so +responsibilities for the secretary. most + + align:start position:0% +responsibilities for the secretary. most + + + align:start position:0% +responsibilities for the secretary. most +obviously record every and all ideas. + + align:start position:0% +obviously record every and all ideas. + + + align:start position:0% +obviously record every and all ideas. +It's like write it all down. You have to + + align:start position:0% +It's like write it all down. You have to + + + align:start position:0% +It's like write it all down. You have to +write it all down. This is so important. + + align:start position:0% +write it all down. This is so important. + + + align:start position:0% +write it all down. This is so important. +Um this one is often overlooked. Uh + + align:start position:0% +Um this one is often overlooked. Uh + + + align:start position:0% +Um this one is often overlooked. Uh +monitoring the schedule and the duration + + align:start position:0% +monitoring the schedule and the duration + + + align:start position:0% +monitoring the schedule and the duration +of the session. Um something I learned a + + align:start position:0% +of the session. Um something I learned a + + + align:start position:0% +of the session. Um something I learned a +long long long time ago is one of the + + align:start position:0% +long long long time ago is one of the + + + align:start position:0% +long long long time ago is one of the +worst things that can happen is meetings + + align:start position:0% +worst things that can happen is meetings + + + align:start position:0% +worst things that can happen is meetings +that run over or meetings that start + + align:start position:0% +that run over or meetings that start + + + align:start position:0% +that run over or meetings that start +late or meetings um you know that don't + + align:start position:0% +late or meetings um you know that don't + + + align:start position:0% +late or meetings um you know that don't +adhere to a schedule. no no better way + + align:start position:0% +adhere to a schedule. no no better way + + + align:start position:0% +adhere to a schedule. no no better way +to kind of uh you know lose your + + align:start position:0% +to kind of uh you know lose your + + + align:start position:0% +to kind of uh you know lose your +employees or lose your staff um than to + + align:start position:0% +employees or lose your staff um than to + + + align:start position:0% +employees or lose your staff um than to +to kind of bite into their time. Um and + + align:start position:0% +to kind of bite into their time. Um and + + + align:start position:0% +to kind of bite into their time. Um and +so you know making sure that it's + + align:start position:0% +so you know making sure that it's + + + align:start position:0% +so you know making sure that it's +constrained and that it meets the + + align:start position:0% +constrained and that it meets the + + + align:start position:0% +constrained and that it meets the +duration is really important. And so you + + align:start position:0% +duration is really important. And so you + + + align:start position:0% +duration is really important. And so you +know may seem simple but timing the + + align:start position:0% +know may seem simple but timing the + + + align:start position:0% +know may seem simple but timing the +thing. Um and then of course if + + align:start position:0% +thing. Um and then of course if + + + align:start position:0% +thing. Um and then of course if +applicable participating in the + + align:start position:0% +applicable participating in the + + + align:start position:0% +applicable participating in the +brainstorming you know like I said all + + align:start position:0% +brainstorming you know like I said all + + + align:start position:0% +brainstorming you know like I said all +voices um all voices should be heard and + + align:start position:0% +voices um all voices should be heard and + + + align:start position:0% +voices um all voices should be heard and +that you know oftentimes would mean that + + align:start position:0% +that you know oftentimes would mean that + + + align:start position:0% +that you know oftentimes would mean that +the secretary is a uh is a creative + + align:start position:0% +the secretary is a uh is a creative + + + align:start position:0% +the secretary is a uh is a creative +professional as well. Um And so make + + align:start position:0% +professional as well. Um And so make + + + align:start position:0% +professional as well. Um And so make +sure that you participate quickly. + + align:start position:0% +sure that you participate quickly. + + + align:start position:0% +sure that you participate quickly. +So + + align:start position:0% +So + + + align:start position:0% +So +we've got a few exercises now to get you + + align:start position:0% +we've got a few exercises now to get you + + + align:start position:0% +we've got a few exercises now to get you +acclimated to the idea of brainstorming. + + align:start position:0% +acclimated to the idea of brainstorming. + + + align:start position:0% +acclimated to the idea of brainstorming. +Um the first one is an actual individual + + align:start position:0% +Um the first one is an actual individual + + + align:start position:0% +Um the first one is an actual individual +brainstorm. So uh if you have paper, + + align:start position:0% +brainstorm. So uh if you have paper, + + + align:start position:0% +brainstorm. So uh if you have paper, +grab some paper. + + align:start position:0% +grab some paper. + + + align:start position:0% +grab some paper. +If anyone's lacking either writing + + align:start position:0% +If anyone's lacking either writing + + + align:start position:0% +If anyone's lacking either writing +equipment or paper, + + align:start position:0% +equipment or paper, + + + align:start position:0% +equipment or paper, +>> you could use a note card, too. It's + + align:start position:0% +>> you could use a note card, too. It's + + + align:start position:0% +>> you could use a note card, too. It's +really just something to write on other + + align:start position:0% +really just something to write on other + + + align:start position:0% +really just something to write on other +than the table. + + align:start position:0% + + + + align:start position:0% + +Not cards are totally fine. + + align:start position:0% +Not cards are totally fine. + + + align:start position:0% +Not cards are totally fine. +>> Um, I'll, as you guys are getting ready, + + align:start position:0% +>> Um, I'll, as you guys are getting ready, + + + align:start position:0% +>> Um, I'll, as you guys are getting ready, +I'll continue to talk. This is actually + + align:start position:0% +I'll continue to talk. This is actually + + + align:start position:0% +I'll continue to talk. This is actually +something that I didn't mention in the + + align:start position:0% +something that I didn't mention in the + + + align:start position:0% +something that I didn't mention in the +process, but what is actually very + + align:start position:0% +process, but what is actually very + + + align:start position:0% +process, but what is actually very +useful to the brainstorming process. I + + align:start position:0% +useful to the brainstorming process. I + + + align:start position:0% +useful to the brainstorming process. I +think doing warm-ups before your actual + + align:start position:0% +think doing warm-ups before your actual + + + align:start position:0% +think doing warm-ups before your actual +brainstorm is useful. Um, you know, + + align:start position:0% +brainstorm is useful. Um, you know, + + + align:start position:0% +brainstorm is useful. Um, you know, +people show up just for lunch, + + align:start position:0% +people show up just for lunch, + + + align:start position:0% +people show up just for lunch, +especially because one of those eating. + + align:start position:0% +especially because one of those eating. + + + align:start position:0% +especially because one of those eating. +Um, you know, people, you know, + + align:start position:0% +Um, you know, people, you know, + + + align:start position:0% +Um, you know, people, you know, +sometimes they're tired. People just + + align:start position:0% +sometimes they're tired. People just + + + align:start position:0% +sometimes they're tired. People just +might have other things on the brain. + + align:start position:0% +might have other things on the brain. + + + align:start position:0% +might have other things on the brain. +So, getting getting in the habit, + + align:start position:0% +So, getting getting in the habit, + + + align:start position:0% +So, getting getting in the habit, +getting warmed up to uh being creative, + + align:start position:0% +getting warmed up to uh being creative, + + + align:start position:0% +getting warmed up to uh being creative, +um, is important. I I tend to find it's + + align:start position:0% +um, is important. I I tend to find it's + + + align:start position:0% +um, is important. I I tend to find it's +a rare it's a rare kind of person who + + align:start position:0% +a rare it's a rare kind of person who + + + align:start position:0% +a rare it's a rare kind of person who +you just sort of give a blank piece of + + align:start position:0% +you just sort of give a blank piece of + + + align:start position:0% +you just sort of give a blank piece of +paper to and you're like, "Ah, make + + align:start position:0% +paper to and you're like, "Ah, make + + + align:start position:0% +paper to and you're like, "Ah, make +something. Go be creative." And they're + + align:start position:0% +something. Go be creative." And they're + + + align:start position:0% +something. Go be creative." And they're +like, they just like whip something out, + + align:start position:0% +like, they just like whip something out, + + + align:start position:0% +like, they just like whip something out, +right? You got you got to kind of get + + align:start position:0% +right? You got you got to kind of get + + + align:start position:0% +right? You got you got to kind of get +warmed up. Um, you know, visual artists + + align:start position:0% +warmed up. Um, you know, visual artists + + + align:start position:0% +warmed up. Um, you know, visual artists +sketch constantly and that that makes + + align:start position:0% +sketch constantly and that that makes + + + align:start position:0% +sketch constantly and that that makes +sense and I make film sketches. Um, I I + + align:start position:0% +sense and I make film sketches. Um, I I + + + align:start position:0% +sense and I make film sketches. Um, I I +just make dumb pieces of music that I'll + + align:start position:0% +just make dumb pieces of music that I'll + + + align:start position:0% +just make dumb pieces of music that I'll +maybe never use for anything, but maybe + + align:start position:0% +maybe never use for anything, but maybe + + + align:start position:0% +maybe never use for anything, but maybe +I will. Um, who knows? I make stupid + + align:start position:0% +I will. Um, who knows? I make stupid + + + align:start position:0% +I will. Um, who knows? I make stupid +sound effects in the shower. Um, I + + align:start position:0% +sound effects in the shower. Um, I + + + align:start position:0% +sound effects in the shower. Um, I +consider that warming up for work. Um, + + align:start position:0% +consider that warming up for work. Um, + + + align:start position:0% +consider that warming up for work. Um, +so, uh, you know, you have to kind of + + align:start position:0% +so, uh, you know, you have to kind of + + + align:start position:0% +so, uh, you know, you have to kind of +get warmed up. And so, this is just a + + align:start position:0% +get warmed up. And so, this is just a + + + align:start position:0% +get warmed up. And so, this is just a +really quick five minute, uh, five + + align:start position:0% +really quick five minute, uh, five + + + align:start position:0% +really quick five minute, uh, five +minute warm up. And the idea is, um, + + align:start position:0% +minute warm up. And the idea is, um, + + + align:start position:0% +minute warm up. And the idea is, um, +write anything that comes to your mind + + align:start position:0% +write anything that comes to your mind + + + align:start position:0% +write anything that comes to your mind +for this specific problem. And I'll show + + align:start position:0% +for this specific problem. And I'll show + + + align:start position:0% +for this specific problem. And I'll show +you a picture. brainstorm possible uses. + + align:start position:0% +you a picture. brainstorm possible uses. + + + align:start position:0% +you a picture. brainstorm possible uses. +It's not really brainstorm. It's more of + + align:start position:0% +It's not really brainstorm. It's more of + + + align:start position:0% +It's not really brainstorm. It's more of +just like a you individually come up + + align:start position:0% +just like a you individually come up + + + align:start position:0% +just like a you individually come up +with creative ideas uh creative uses uh + + align:start position:0% +with creative ideas uh creative uses uh + + + align:start position:0% +with creative ideas uh creative uses uh +for the following item and I'll give you + + align:start position:0% +for the following item and I'll give you + + + align:start position:0% +for the following item and I'll give you +five minutes starting now. + + align:start position:0% + + + + align:start position:0% + +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +Hopefully was good for a warm up. Quick + + align:start position:0% +Hopefully was good for a warm up. Quick + + + align:start position:0% +Hopefully was good for a warm up. Quick +question and show + + align:start position:0% +question and show + + + align:start position:0% +question and show +and be honest. + + align:start position:0% +and be honest. + + + align:start position:0% +and be honest. +This is a safe mind. + + align:start position:0% +This is a safe mind. + + + align:start position:0% +This is a safe mind. +How many of you had an idea that you did + + align:start position:0% +How many of you had an idea that you did + + + align:start position:0% +How many of you had an idea that you did +not write down? How many of you self + + align:start position:0% +not write down? How many of you self + + + align:start position:0% +not write down? How many of you self +censored yourself with an idea? + + align:start position:0% +censored yourself with an idea? + + + align:start position:0% +censored yourself with an idea? +Yeah. You're like, "Oh, that's just + + align:start position:0% +Yeah. You're like, "Oh, that's just + + + align:start position:0% +Yeah. You're like, "Oh, that's just +dumb." See, it's really it's hard to get + + align:start position:0% +dumb." See, it's really it's hard to get + + + align:start position:0% +dumb." See, it's really it's hard to get +out of the habit of doing that. It's + + align:start position:0% +out of the habit of doing that. It's + + + align:start position:0% +out of the habit of doing that. It's +hard to get out of this kind of this + + align:start position:0% +hard to get out of this kind of this + + + align:start position:0% +hard to get out of this kind of this +habit of self- judgment. Um, and it's + + align:start position:0% +habit of self- judgment. Um, and it's + + + align:start position:0% +habit of self- judgment. Um, and it's +really important. Um, you know, that + + align:start position:0% +really important. Um, you know, that + + + align:start position:0% +really important. Um, you know, that +that dumb idea that you think was + + align:start position:0% +that dumb idea that you think was + + + align:start position:0% +that dumb idea that you think was +worthless might be a good one. Does + + align:start position:0% +worthless might be a good one. Does + + + align:start position:0% +worthless might be a good one. Does +anyone who raised their hand want to + + align:start position:0% +anyone who raised their hand want to + + + align:start position:0% +anyone who raised their hand want to +share what their censored idea was? just + + align:start position:0% +share what their censored idea was? just + + + align:start position:0% +share what their censored idea was? just +to exercise the demons, so to speak. + + align:start position:0% +to exercise the demons, so to speak. + + + align:start position:0% +to exercise the demons, so to speak. +>> No, nothing. + + align:start position:0% +>> No, nothing. + + + align:start position:0% +>> No, nothing. +>> All right. Who wants to share some ideas + + align:start position:0% +>> All right. Who wants to share some ideas + + + align:start position:0% +>> All right. Who wants to share some ideas +that they did write down? All right. + + align:start position:0% +that they did write down? All right. + + + align:start position:0% +that they did write down? All right. +Here we go. + + align:start position:0% +Here we go. + + + align:start position:0% +Here we go. +>> See, I have a lot. + + align:start position:0% +>> See, I have a lot. + + + align:start position:0% +>> See, I have a lot. +>> Yeah. Well, throw throw us a couple that + + align:start position:0% +>> Yeah. Well, throw throw us a couple that + + + align:start position:0% +>> Yeah. Well, throw throw us a couple that +are your favorite. + + align:start position:0% +are your favorite. + + + align:start position:0% +are your favorite. +>> See, lockpick, MacGyver, connecting + + align:start position:0% +>> See, lockpick, MacGyver, connecting + + + align:start position:0% +>> See, lockpick, MacGyver, connecting +circuits. + + align:start position:0% +circuits. + + + align:start position:0% +circuits. +>> There you go. + + align:start position:0% +>> There you go. + + + align:start position:0% +>> There you go. +>> Carrying cards, um, a knife, clothes + + align:start position:0% +>> Carrying cards, um, a knife, clothes + + + align:start position:0% +>> Carrying cards, um, a knife, clothes +hanger, chopsticks, a dowster, um, stir. + + align:start position:0% +hanger, chopsticks, a dowster, um, stir. + + + align:start position:0% +hanger, chopsticks, a dowster, um, stir. +See, connect batteries. Air of tires + + align:start position:0% +See, connect batteries. Air of tires + + + align:start position:0% +See, connect batteries. Air of tires +emote tool nose picker + + align:start position:0% +emote tool nose picker + + + align:start position:0% +emote tool nose picker +>> staple. A staple + + align:start position:0% +>> staple. A staple + + + align:start position:0% +>> staple. A staple +>> and a paper bra. I have a lot of things. + + align:start position:0% +>> and a paper bra. I have a lot of things. + + + align:start position:0% +>> and a paper bra. I have a lot of things. +>> Yeah. Good. No, that's awesome. + + align:start position:0% +>> Yeah. Good. No, that's awesome. + + + align:start position:0% +>> Yeah. Good. No, that's awesome. +>> All right. I got Let's see. Um + + align:start position:0% +>> All right. I got Let's see. Um + + + align:start position:0% +>> All right. I got Let's see. Um +fingernail cleaner, an eyelash + + align:start position:0% +fingernail cleaner, an eyelash + + + align:start position:0% +fingernail cleaner, an eyelash +straightener, basically a rail gun ammo, + + align:start position:0% +straightener, basically a rail gun ammo, + + + align:start position:0% +straightener, basically a rail gun ammo, +a balloon annihilator, and an official + + align:start position:0% +a balloon annihilator, and an official + + + align:start position:0% +a balloon annihilator, and an official +Tamagotchi TM resetter. + + align:start position:0% + + + + align:start position:0% + +>> Yeah. resets a lot of things. How about + + align:start position:0% +>> Yeah. resets a lot of things. How about + + + align:start position:0% +>> Yeah. resets a lot of things. How about +over the side? Yeah. + + align:start position:0% + + + + align:start position:0% + +>> Catch fish with it by turning into + + align:start position:0% +>> Catch fish with it by turning into + + + align:start position:0% +>> Catch fish with it by turning into +scratch messages with it. Use it as a + + align:start position:0% +scratch messages with it. Use it as a + + + align:start position:0% +scratch messages with it. Use it as a +key ring. Conduct electricity with it. + + align:start position:0% +key ring. Conduct electricity with it. + + + align:start position:0% +key ring. Conduct electricity with it. +Make it into jewelry. Um fix umbrellas + + align:start position:0% +Make it into jewelry. Um fix umbrellas + + + align:start position:0% +Make it into jewelry. Um fix umbrellas +and what have you with it, which I've + + align:start position:0% +and what have you with it, which I've + + + align:start position:0% +and what have you with it, which I've +done before. + + align:start position:0% +done before. + + + align:start position:0% +done before. +Money clip. Use it as a skewer for + + align:start position:0% +Money clip. Use it as a skewer for + + + align:start position:0% +Money clip. Use it as a skewer for +cooking. + + align:start position:0% +cooking. + + + align:start position:0% +cooking. +uh put it on top of a door and so when + + align:start position:0% +uh put it on top of a door and so when + + + align:start position:0% +uh put it on top of a door and so when +people open it falls on the ground you + + align:start position:0% +people open it falls on the ground you + + + align:start position:0% +people open it falls on the ground you +know somebody's been in your room + + align:start position:0% + + + + align:start position:0% + +>> oil + + align:start position:0% + + + + align:start position:0% + +accessory + + align:start position:0% +accessory + + + align:start position:0% +accessory +that's a good question + + align:start position:0% + + + + align:start position:0% + +>> uh I had a hair styling accessory + + align:start position:0% +>> uh I had a hair styling accessory + + + align:start position:0% +>> uh I had a hair styling accessory +projectile something you could mel down + + align:start position:0% +projectile something you could mel down + + + align:start position:0% +projectile something you could mel down +to for metal and porn out stuff. + + align:start position:0% +to for metal and porn out stuff. + + + align:start position:0% +to for metal and porn out stuff. +>> Uh that's something you could bend and + + align:start position:0% +>> Uh that's something you could bend and + + + align:start position:0% +>> Uh that's something you could bend and +put on chairs and people sit down and + + align:start position:0% +put on chairs and people sit down and + + + align:start position:0% +put on chairs and people sit down and +poke them. Um modern art. Um I thought + + align:start position:0% +poke them. Um modern art. Um I thought + + + align:start position:0% +poke them. Um modern art. Um I thought +of you could like try to get a bunch and + + align:start position:0% +of you could like try to get a bunch and + + + align:start position:0% +of you could like try to get a bunch and +fill a dorm room with it as a prank or + + align:start position:0% +fill a dorm room with it as a prank or + + + align:start position:0% +fill a dorm room with it as a prank or +something. Um toothpick + + align:start position:0% +something. Um toothpick + + + align:start position:0% +something. Um toothpick +hold stuff open for emergency surgery. + + align:start position:0% + + + + align:start position:0% + +>> Cool. + + align:start position:0% +>> Cool. + + + align:start position:0% +>> Cool. +I thought you could uh bend it into an + + align:start position:0% +I thought you could uh bend it into an + + + align:start position:0% +I thought you could uh bend it into an +interesting flat shape and then put it + + align:start position:0% +interesting flat shape and then put it + + + align:start position:0% +interesting flat shape and then put it +in ink and use it as a stamp. + + align:start position:0% +in ink and use it as a stamp. + + + align:start position:0% +in ink and use it as a stamp. +>> Very nice. Very cool. Um cool. Yeah. Go + + align:start position:0% +>> Very nice. Very cool. Um cool. Yeah. Go + + + align:start position:0% +>> Very nice. Very cool. Um cool. Yeah. Go +ahead. + + align:start position:0% +ahead. + + + align:start position:0% +ahead. +>> Uh game bits and tokens holder for + + align:start position:0% +>> Uh game bits and tokens holder for + + + align:start position:0% +>> Uh game bits and tokens holder for +dipping something into liquids. Um pie + + align:start position:0% +dipping something into liquids. Um pie + + + align:start position:0% +dipping something into liquids. Um pie +clips and keeping small boards together. + + align:start position:0% +clips and keeping small boards together. + + + align:start position:0% +clips and keeping small boards together. +>> Sure. + + align:start position:0% +>> Sure. + + + align:start position:0% +>> Sure. +>> Mini rock garden. + + align:start position:0% + + + + align:start position:0% + +Good + + align:start position:0% +Good + + + align:start position:0% +Good +>> heat generator. If you uh work hard in + + align:start position:0% +>> heat generator. If you uh work hard in + + + align:start position:0% +>> heat generator. If you uh work hard in +it by bending it and then bending it and + + align:start position:0% +it by bending it and then bending it and + + + align:start position:0% +it by bending it and then bending it and +then it gets hot. + + align:start position:0% +then it gets hot. + + + align:start position:0% +then it gets hot. +>> Very nice. + + align:start position:0% +>> Very nice. + + + align:start position:0% +>> Very nice. +>> As long as it doesn't break. + + align:start position:0% +>> As long as it doesn't break. + + + align:start position:0% +>> As long as it doesn't break. +>> I think of a souvenir as a totem for a + + align:start position:0% +>> I think of a souvenir as a totem for a + + + align:start position:0% +>> I think of a souvenir as a totem for a +lost robot. + + align:start position:0% +lost robot. + + + align:start position:0% +lost robot. +>> That's good. + + align:start position:0% +>> That's good. + + + align:start position:0% +>> That's good. +>> You say that again. + + align:start position:0% +>> You say that again. + + + align:start position:0% +>> You say that again. +>> Let's say like there's a robot made by + + align:start position:0% +>> Let's say like there's a robot made by + + + align:start position:0% +>> Let's say like there's a robot made by +human but it's lost in space. They have + + align:start position:0% +human but it's lost in space. They have + + + align:start position:0% +human but it's lost in space. They have +to remind it become like a secret thing. + + align:start position:0% +to remind it become like a secret thing. + + + align:start position:0% +to remind it become like a secret thing. +>> Yeah. My favorite use for a paperclip is + + align:start position:0% +>> Yeah. My favorite use for a paperclip is + + + align:start position:0% +>> Yeah. My favorite use for a paperclip is +cleaning the lint out of my uh iPhone + + align:start position:0% +cleaning the lint out of my uh iPhone + + + align:start position:0% +cleaning the lint out of my uh iPhone +ear jack, which drives me absolutely + + align:start position:0% +ear jack, which drives me absolutely + + + align:start position:0% +ear jack, which drives me absolutely +nuts. So, I'm running on reserve battery + + align:start position:0% +nuts. So, I'm running on reserve battery + + + align:start position:0% +nuts. So, I'm running on reserve battery +power and my slideshow has been + + align:start position:0% +power and my slideshow has been + + + align:start position:0% +power and my slideshow has been +suspended on in my office. There's a uh + + align:start position:0% +suspended on in my office. There's a uh + + + align:start position:0% +suspended on in my office. There's a uh +there's a air. + + align:start position:0% +there's a air. + + + align:start position:0% +there's a air. +So, um + + align:start position:0% +So, um + + + align:start position:0% +So, um +so yeah, how did we feel about that + + align:start position:0% +so yeah, how did we feel about that + + + align:start position:0% +so yeah, how did we feel about that +exercise? Got you loosened up a little + + align:start position:0% +exercise? Got you loosened up a little + + + align:start position:0% +exercise? Got you loosened up a little +bit. Got you thinking about some ideas. + + align:start position:0% +bit. Got you thinking about some ideas. + + + align:start position:0% +bit. Got you thinking about some ideas. +Got you feeling a little creative juices + + align:start position:0% +Got you feeling a little creative juices + + + align:start position:0% +Got you feeling a little creative juices +fine. We've got three more exercises + + align:start position:0% +fine. We've got three more exercises + + + align:start position:0% +fine. We've got three more exercises +that we're going to do. Um, + + align:start position:0% +that we're going to do. Um, + + + align:start position:0% +that we're going to do. Um, +so much brainstorming. + + align:start position:0% +so much brainstorming. + + + align:start position:0% +so much brainstorming. +This is the hardest work I've ever done + + align:start position:0% +This is the hardest work I've ever done + + + align:start position:0% +This is the hardest work I've ever done +to get my chicken. No. Um, yeah. So, + + align:start position:0% +to get my chicken. No. Um, yeah. So, + + + align:start position:0% +to get my chicken. No. Um, yeah. So, +we've got a few more exercise to get you + + align:start position:0% +we've got a few more exercise to get you + + + align:start position:0% +we've got a few more exercise to get you +guys kind of comfortable, get you guys, + + align:start position:0% +guys kind of comfortable, get you guys, + + + align:start position:0% +guys kind of comfortable, get you guys, +you know, relaxed with this kind of + + align:start position:0% +you know, relaxed with this kind of + + + align:start position:0% +you know, relaxed with this kind of +brainstorming process. The next one is + + align:start position:0% +brainstorming process. The next one is + + + align:start position:0% +brainstorming process. The next one is +going to be a group exercise. Um, I'm + + align:start position:0% +going to be a group exercise. Um, I'm + + + align:start position:0% +going to be a group exercise. Um, I'm +going to wait to describe it until I can + + align:start position:0% +going to wait to describe it until I can + + + align:start position:0% +going to wait to describe it until I can +get uh get my slideshow. Anybody else + + align:start position:0% +get uh get my slideshow. Anybody else + + + align:start position:0% +get uh get my slideshow. Anybody else +have any particularly choice paperclip + + align:start position:0% +have any particularly choice paperclip + + + align:start position:0% +have any particularly choice paperclip +ideas? Start one. + + align:start position:0% +ideas? Start one. + + + align:start position:0% +ideas? Start one. +>> A sign sine wave generator. + + align:start position:0% +>> A sign sine wave generator. + + + align:start position:0% +>> A sign sine wave generator. +>> Very good. + + align:start position:0% +>> Very good. + + + align:start position:0% +>> Very good. +wireframe doll. + + align:start position:0% + + + + align:start position:0% + +>> All right. + + align:start position:0% + + + + align:start position:0% + +>> Hold up. Stop looking at + + align:start position:0% +>> Hold up. Stop looking at + + + align:start position:0% +>> Hold up. Stop looking at +it like as a spear. + + align:start position:0% +it like as a spear. + + + align:start position:0% +it like as a spear. +>> Oh, yeah. + + align:start position:0% +>> Oh, yeah. + + + align:start position:0% +>> Oh, yeah. +Man versus Wild like catch fish with it + + align:start position:0% +Man versus Wild like catch fish with it + + + align:start position:0% +Man versus Wild like catch fish with it +or + + align:start position:0% +or + + + align:start position:0% +or +>> something to chew on. + + align:start position:0% + + + + align:start position:0% + +>> Launcher rubber band launcher + + align:start position:0% +>> Launcher rubber band launcher + + + align:start position:0% +>> Launcher rubber band launcher +>> letting air out tires. + + align:start position:0% + + + + align:start position:0% + +You heard of the guy who had an + + align:start position:0% +You heard of the guy who had an + + + align:start position:0% +You heard of the guy who had an +oversized red tape equip and ended up + + align:start position:0% +oversized red tape equip and ended up + + + align:start position:0% +oversized red tape equip and ended up +trading it for a house + + align:start position:0% +trading it for a house + + + align:start position:0% +trading it for a house +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +towards a house. + + align:start position:0% + + + + align:start position:0% + +>> Pretty cool. So, so hopefully that got + + align:start position:0% +>> Pretty cool. So, so hopefully that got + + + align:start position:0% +>> Pretty cool. So, so hopefully that got +you loosened up. I do want to just + + align:start position:0% +you loosened up. I do want to just + + + align:start position:0% +you loosened up. I do want to just +emphasize again for those of you who + + align:start position:0% +emphasize again for those of you who + + + align:start position:0% +emphasize again for those of you who +raised your hand and even those of you + + align:start position:0% +raised your hand and even those of you + + + align:start position:0% +raised your hand and even those of you +who did not raise your hand because you + + align:start position:0% +who did not raise your hand because you + + + align:start position:0% +who did not raise your hand because you +were censoring the truth because you're + + align:start position:0% +were censoring the truth because you're + + + align:start position:0% +were censoring the truth because you're +afraid try not to self censor. Um really + + align:start position:0% +afraid try not to self censor. Um really + + + align:start position:0% +afraid try not to self censor. Um really +it's important to brainstorming. I bet + + align:start position:0% +it's important to brainstorming. I bet + + + align:start position:0% +it's important to brainstorming. I bet +some + + align:start position:0% +some + + + align:start position:0% +some +>> Yeah, I know. Stop self-centering. I bet + + align:start position:0% +>> Yeah, I know. Stop self-centering. I bet + + + align:start position:0% +>> Yeah, I know. Stop self-centering. I bet +I bet those crappy ideas that you write + + align:start position:0% +I bet those crappy ideas that you write + + + align:start position:0% +I bet those crappy ideas that you write +down are actually really awesome. So um + + align:start position:0% +down are actually really awesome. So um + + + align:start position:0% +down are actually really awesome. So um +activity number two uh we're going to + + align:start position:0% +activity number two uh we're going to + + + align:start position:0% +activity number two uh we're going to +work as one large group. Um this is our + + align:start position:0% +work as one large group. Um this is our + + + align:start position:0% +work as one large group. Um this is our +con shell. Doesn't look like one, I + + align:start position:0% +con shell. Doesn't look like one, I + + + align:start position:0% +con shell. Doesn't look like one, I +know, but um you know the principle + + align:start position:0% +know, but um you know the principle + + + align:start position:0% +know, but um you know the principle +still applies. Um this is just to kind + + align:start position:0% +still applies. Um this is just to kind + + + align:start position:0% +still applies. Um this is just to kind +of get us in the habit in the shape of + + align:start position:0% +of get us in the habit in the shape of + + + align:start position:0% +of get us in the habit in the shape of +uh kind of speaking one at a time uh not + + align:start position:0% +uh kind of speaking one at a time uh not + + + align:start position:0% +uh kind of speaking one at a time uh not +interrupting each other. Um and in some + + align:start position:0% +interrupting each other. Um and in some + + + align:start position:0% +interrupting each other. Um and in some +senses building on each other's ideas + + align:start position:0% +senses building on each other's ideas + + + align:start position:0% +senses building on each other's ideas +too, right? There's something in the + + align:start position:0% +too, right? There's something in the + + + align:start position:0% +too, right? There's something in the +physical kind of passing of the ball + + align:start position:0% +physical kind of passing of the ball + + + align:start position:0% +physical kind of passing of the ball +after you've heard someone's idea that + + align:start position:0% +after you've heard someone's idea that + + + align:start position:0% +after you've heard someone's idea that +might encourage that sort of synthesis + + align:start position:0% +might encourage that sort of synthesis + + + align:start position:0% +might encourage that sort of synthesis +of ideas as you're going. Um I will be + + align:start position:0% +of ideas as you're going. Um I will be + + + align:start position:0% +of ideas as you're going. Um I will be +your fearless leader. Um all that means + + align:start position:0% +your fearless leader. Um all that means + + + align:start position:0% +your fearless leader. Um all that means +is I just kind of make sure you're not + + align:start position:0% +is I just kind of make sure you're not + + + align:start position:0% +is I just kind of make sure you're not +interrupting each other. Um uh and we're + + align:start position:0% +interrupting each other. Um uh and we're + + + align:start position:0% +interrupting each other. Um uh and we're +going to brainstorm solutions to uh a a + + align:start position:0% +going to brainstorm solutions to uh a a + + + align:start position:0% +going to brainstorm solutions to uh a a +design problem. Uh this one I think is + + align:start position:0% +design problem. Uh this one I think is + + + align:start position:0% +design problem. Uh this one I think is +actually a lot of fun. Um so I will show + + align:start position:0% +actually a lot of fun. Um so I will show + + + align:start position:0% +actually a lot of fun. Um so I will show +you the design problem. I will maybe + + align:start position:0% +you the design problem. I will maybe + + + align:start position:0% +you the design problem. I will maybe +throw out an idea and then I will toss + + align:start position:0% +throw out an idea and then I will toss + + + align:start position:0% +throw out an idea and then I will toss +the con shell to first person who wants + + align:start position:0% +the con shell to first person who wants + + + align:start position:0% +the con shell to first person who wants +it and then it doesn't have to come back + + align:start position:0% +it and then it doesn't have to come back + + + align:start position:0% +it and then it doesn't have to come back +to me. Just anyone who wants it throw up + + align:start position:0% +to me. Just anyone who wants it throw up + + + align:start position:0% +to me. Just anyone who wants it throw up +your hand and we'll kind of keep moving + + align:start position:0% +your hand and we'll kind of keep moving + + + align:start position:0% +your hand and we'll kind of keep moving +around. Please close the lids on your + + align:start position:0% +around. Please close the lids on your + + + align:start position:0% +around. Please close the lids on your +drinks. + + align:start position:0% +drinks. + + + align:start position:0% +drinks. +put put away put away your crystal stuff + + align:start position:0% +put put away put away your crystal stuff + + + align:start position:0% +put put away put away your crystal stuff +that you don't want to shatter. Um, so + + align:start position:0% +that you don't want to shatter. Um, so + + + align:start position:0% +that you don't want to shatter. Um, so +we will take approximately 15 minutes on + + align:start position:0% +we will take approximately 15 minutes on + + + align:start position:0% +we will take approximately 15 minutes on +this. We'll see how our momentum goes. + + align:start position:0% +this. We'll see how our momentum goes. + + + align:start position:0% +this. We'll see how our momentum goes. +Um, so you just finished updating Tetris + + align:start position:0% +Um, so you just finished updating Tetris + + + align:start position:0% +Um, so you just finished updating Tetris +for Xbox Live Arcade. Awesome. I don't + + align:start position:0% +for Xbox Live Arcade. Awesome. I don't + + + align:start position:0% +for Xbox Live Arcade. Awesome. I don't +know how you got the rights, but that's + + align:start position:0% +know how you got the rights, but that's + + + align:start position:0% +know how you got the rights, but that's +great. Um, Microsoft is demanding a set + + align:start position:0% +great. Um, Microsoft is demanding a set + + + align:start position:0% +great. Um, Microsoft is demanding a set +of achievements uh for integrating the + + align:start position:0% +of achievements uh for integrating the + + + align:start position:0% +of achievements uh for integrating the +game into their online service because + + align:start position:0% +game into their online service because + + + align:start position:0% +game into their online service because +unless you have achievements, it's not a + + align:start position:0% +unless you have achievements, it's not a + + + align:start position:0% +unless you have achievements, it's not a +real game. Um, + + align:start position:0% +real game. Um, + + + align:start position:0% +real game. Um, +so we are going to brainstorm possible + + align:start position:0% +so we are going to brainstorm possible + + + align:start position:0% +so we are going to brainstorm possible +player achievements uh for your new + + align:start position:0% +player achievements uh for your new + + + align:start position:0% +player achievements uh for your new +version of Tetris. You know what + + align:start position:0% +version of Tetris. You know what + + + align:start position:0% +version of Tetris. You know what +achievements are, right? Those little + + align:start position:0% +achievements are, right? Those little + + + align:start position:0% +achievements are, right? Those little +things that pop up on your Xbox every + + align:start position:0% +things that pop up on your Xbox every + + + align:start position:0% +things that pop up on your Xbox every +time you do anything. Um, so that is our + + align:start position:0% +time you do anything. Um, so that is our + + + align:start position:0% +time you do anything. Um, so that is our +idea for Tetris achievements. And I'll + + align:start position:0% +idea for Tetris achievements. And I'll + + + align:start position:0% +idea for Tetris achievements. And I'll +start. Uh, how about for actually + + align:start position:0% +start. Uh, how about for actually + + + align:start position:0% +start. Uh, how about for actually +getting four lines? You get a Tetris + + align:start position:0% +getting four lines? You get a Tetris + + + align:start position:0% +getting four lines? You get a Tetris +achievement must be next. + + align:start position:0% +achievement must be next. + + + align:start position:0% +achievement must be next. +>> Uh, you get an achievement for losing as + + align:start position:0% +>> Uh, you get an achievement for losing as + + + align:start position:0% +>> Uh, you get an achievement for losing as +quickly as possible, which I think would + + align:start position:0% +quickly as possible, which I think would + + + align:start position:0% +quickly as possible, which I think would +just be like Very good. + + align:start position:0% +just be like Very good. + + + align:start position:0% +just be like Very good. +>> Getting three lines with S piece. + + align:start position:0% +>> Getting three lines with S piece. + + + align:start position:0% +>> Getting three lines with S piece. +>> Uh drawing some sort of unique little + + align:start position:0% +>> Uh drawing some sort of unique little + + + align:start position:0% +>> Uh drawing some sort of unique little +picture with the Tetris blocks like uh + + align:start position:0% +picture with the Tetris blocks like uh + + + align:start position:0% +picture with the Tetris blocks like uh +you know something perhaps + + align:start position:0% +you know something perhaps + + + align:start position:0% +you know something perhaps +>> putting one of each block down. + + align:start position:0% + + + + align:start position:0% + +>> Uh lasting for a certain amount of time + + align:start position:0% +>> Uh lasting for a certain amount of time + + + align:start position:0% +>> Uh lasting for a certain amount of time +without them ever getting above a + + align:start position:0% +without them ever getting above a + + + align:start position:0% +without them ever getting above a +certain height. + + align:start position:0% + + + + align:start position:0% + +a certain amount of time without ever + + align:start position:0% +a certain amount of time without ever + + + align:start position:0% +a certain amount of time without ever +rotating a piece. + + align:start position:0% +rotating a piece. + + + align:start position:0% +rotating a piece. +>> Modern Tetris games have a system where + + align:start position:0% +>> Modern Tetris games have a system where + + + align:start position:0% +>> Modern Tetris games have a system where +you can rotate indefinitely when your + + align:start position:0% +you can rotate indefinitely when your + + + align:start position:0% +you can rotate indefinitely when your +piece is down. So, you rotate + + align:start position:0% +piece is down. So, you rotate + + + align:start position:0% +piece is down. So, you rotate +indefinitely for a minute or two or + + align:start position:0% +indefinitely for a minute or two or + + + align:start position:0% +indefinitely for a minute or two or +three minutes. + + align:start position:0% +three minutes. + + + align:start position:0% +three minutes. +>> Lasting a certain amount of time without + + align:start position:0% +>> Lasting a certain amount of time without + + + align:start position:0% +>> Lasting a certain amount of time without +ever clearing a line with a straight + + align:start position:0% +ever clearing a line with a straight + + + align:start position:0% +ever clearing a line with a straight +piece. + + align:start position:0% + + + + align:start position:0% + +Putting your piece down underneath + + align:start position:0% +Putting your piece down underneath + + + align:start position:0% +Putting your piece down underneath +another piece + + align:start position:0% +another piece + + + align:start position:0% +another piece +>> into a little hole. + + align:start position:0% +>> into a little hole. + + + align:start position:0% +>> into a little hole. +>> The teeth. + + align:start position:0% +>> The teeth. + + + align:start position:0% +>> The teeth. +>> There you go. Spelling USSR with your + + align:start position:0% +>> There you go. Spelling USSR with your + + + align:start position:0% +>> There you go. Spelling USSR with your +pieces. + + align:start position:0% + + + + align:start position:0% + +>> How's the bathroom? + + align:start position:0% +>> How's the bathroom? + + + align:start position:0% +>> How's the bathroom? +>> Um, making like a congeration of all the + + align:start position:0% +>> Um, making like a congeration of all the + + + align:start position:0% +>> Um, making like a congeration of all the +pieces into like the shape of a regular + + align:start position:0% +pieces into like the shape of a regular + + + align:start position:0% +pieces into like the shape of a regular +piece. + + align:start position:0% + + + + align:start position:0% + +>> Very cool. + + align:start position:0% +>> Very cool. + + + align:start position:0% +>> Very cool. +Uh, basically only moving the pieces in + + align:start position:0% +Uh, basically only moving the pieces in + + + align:start position:0% +Uh, basically only moving the pieces in +B to the music that's playing + + align:start position:0% +B to the music that's playing + + + align:start position:0% +B to the music that's playing +>> spelling your say with your pieces. I + + align:start position:0% +>> spelling your say with your pieces. I + + + align:start position:0% +>> spelling your say with your pieces. I +don't know if it's possible, but doing + + align:start position:0% +don't know if it's possible, but doing + + + align:start position:0% +don't know if it's possible, but doing +it. + + align:start position:0% + + + + align:start position:0% + +>> Uh, high score and high score without + + align:start position:0% +>> Uh, high score and high score without + + + align:start position:0% +>> Uh, high score and high score without +clearing lines. + + align:start position:0% + + + + align:start position:0% + +>> Uh, managing to clear the entire board + + align:start position:0% +>> Uh, managing to clear the entire board + + + align:start position:0% +>> Uh, managing to clear the entire board +in a game that has already reached the + + align:start position:0% +in a game that has already reached the + + + align:start position:0% +in a game that has already reached the +top line but not quite. + + align:start position:0% + + + + align:start position:0% + +putting a piece down without actually uh + + align:start position:0% +putting a piece down without actually uh + + + align:start position:0% +putting a piece down without actually uh +looking at the piece at all. + + align:start position:0% + + + + align:start position:0% + +>> Most pieces per time. + + align:start position:0% +>> Most pieces per time. + + + align:start position:0% +>> Most pieces per time. +>> Sure. + + align:start position:0% + + + + align:start position:0% + +>> One day of continuous tetris + + align:start position:0% +>> One day of continuous tetris + + + align:start position:0% +>> One day of continuous tetris +marathon + + align:start position:0% +marathon + + + align:start position:0% +marathon +>> breaking the previous high. + + align:start position:0% +>> breaking the previous high. + + + align:start position:0% +>> breaking the previous high. +Only ever shifting pieces either right + + align:start position:0% +Only ever shifting pieces either right + + + align:start position:0% +Only ever shifting pieces either right +or the left the entire game. + + align:start position:0% +or the left the entire game. + + + align:start position:0% +or the left the entire game. +>> Ah, + + align:start position:0% +>> Ah, + + + align:start position:0% +>> Ah, +>> doing the marathon challenge but only + + align:start position:0% +>> doing the marathon challenge but only + + + align:start position:0% +>> doing the marathon challenge but only +listening to one piece of music the + + align:start position:0% +listening to one piece of music the + + + align:start position:0% +listening to one piece of music the +entire time. + + align:start position:0% +entire time. + + + align:start position:0% +entire time. +>> The same + + align:start position:0% +>> The same + + + align:start position:0% +>> The same +>> clearing a level by dropping pieces + + align:start position:0% +>> clearing a level by dropping pieces + + + align:start position:0% +>> clearing a level by dropping pieces +before they fall five spaces. + + align:start position:0% +before they fall five spaces. + + + align:start position:0% +before they fall five spaces. +>> All right. + + align:start position:0% + + + + align:start position:0% + +>> Rotating every single piece that you + + align:start position:0% +>> Rotating every single piece that you + + + align:start position:0% +>> Rotating every single piece that you +play. + + align:start position:0% +play. + + + align:start position:0% +play. +>> Oh, very good. + + align:start position:0% +>> Oh, very good. + + + align:start position:0% +>> Oh, very good. +uh never going above a certain line for + + align:start position:0% +uh never going above a certain line for + + + align:start position:0% +uh never going above a certain line for +a certain amount of time. + + align:start position:0% + + + + align:start position:0% + +>> All of the above but on different equity + + align:start position:0% +>> All of the above but on different equity + + + align:start position:0% +>> All of the above but on different equity +levels + + align:start position:0% + + + + align:start position:0% + +>> uh clearing three lines with a T. + + align:start position:0% +>> uh clearing three lines with a T. + + + align:start position:0% +>> uh clearing three lines with a T. +>> Sure. + + align:start position:0% +>> Sure. + + + align:start position:0% +>> Sure. +>> Starting up the game, + + align:start position:0% +>> Starting up the game, + + + align:start position:0% +>> Starting up the game, +>> clearing a kind of screen + + align:start position:0% +>> clearing a kind of screen + + + align:start position:0% +>> clearing a kind of screen +>> using the L block. + + align:start position:0% +>> using the L block. + + + align:start position:0% +>> using the L block. +Doesn't matter how. + + align:start position:0% + + + + align:start position:0% + +different color. So, you know, lines + + align:start position:0% +different color. So, you know, lines + + + align:start position:0% +different color. So, you know, lines +always + + align:start position:0% + + + + align:start position:0% + +>> rotating a piece 720° + + align:start position:0% +>> rotating a piece 720° + + + align:start position:0% +>> rotating a piece 720° +>> only matching pieces such that the new + + align:start position:0% +>> only matching pieces such that the new + + + align:start position:0% +>> only matching pieces such that the new +blocks that fall down are touching + + align:start position:0% +blocks that fall down are touching + + + align:start position:0% +blocks that fall down are touching +blocks of the same color. + + align:start position:0% +blocks of the same color. + + + align:start position:0% +blocks of the same color. +>> Clear two four block segments with two + + align:start position:0% +>> Clear two four block segments with two + + + align:start position:0% +>> Clear two four block segments with two +consecutive uh lines. + + align:start position:0% +consecutive uh lines. + + + align:start position:0% +consecutive uh lines. +Uh, clearing a level using only + + align:start position:0% +Uh, clearing a level using only + + + align:start position:0% +Uh, clearing a level using only +tetrises. + + align:start position:0% + + + + align:start position:0% + +>> Sorry, you can't talk anymore. + + align:start position:0% +>> Sorry, you can't talk anymore. + + + align:start position:0% +>> Sorry, you can't talk anymore. +>> Challenging somebody on your friends + + align:start position:0% +>> Challenging somebody on your friends + + + align:start position:0% +>> Challenging somebody on your friends +list to beat the score. + + align:start position:0% +list to beat the score. + + + align:start position:0% +list to beat the score. +>> Um, fighting against someone on friends + + align:start position:0% +>> Um, fighting against someone on friends + + + align:start position:0% +>> Um, fighting against someone on friends +list to lose faster. + + align:start position:0% + + + + align:start position:0% + +>> Having no holes in the block for + + align:start position:0% +>> Having no holes in the block for + + + align:start position:0% +>> Having no holes in the block for +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Uh, inviting a friend on one of your + + align:start position:0% +Uh, inviting a friend on one of your + + + align:start position:0% +Uh, inviting a friend on one of your +Xbox Live friends to play with you. + + align:start position:0% +Xbox Live friends to play with you. + + + align:start position:0% +Xbox Live friends to play with you. +>> Five consecutive line clears. + + align:start position:0% +>> Five consecutive line clears. + + + align:start position:0% +>> Five consecutive line clears. +>> Beating one of your friends on Xbox Live + + align:start position:0% +>> Beating one of your friends on Xbox Live + + + align:start position:0% +>> Beating one of your friends on Xbox Live +when you play with them. + + align:start position:0% +when you play with them. + + + align:start position:0% +when you play with them. +>> Losing to a friend on Xbox Live. + + align:start position:0% + + + + align:start position:0% + +>> Playing with a friend for one hour + + align:start position:0% +>> Playing with a friend for one hour + + + align:start position:0% +>> Playing with a friend for one hour +continuously one day. + + align:start position:0% + + + + align:start position:0% + +Beating a score set by the original + + align:start position:0% +Beating a score set by the original + + + align:start position:0% +Beating a score set by the original +creator of Tetris. + + align:start position:0% +creator of Tetris. + + + align:start position:0% +creator of Tetris. +>> Clearing a line somewhere above the + + align:start position:0% +>> Clearing a line somewhere above the + + + align:start position:0% +>> Clearing a line somewhere above the +first line. The first line only has one + + align:start position:0% +first line. The first line only has one + + + align:start position:0% +first line. The first line only has one +block filled in. + + align:start position:0% + + + + align:start position:0% + +>> I think it definitely is. + + align:start position:0% + + + + align:start position:0% + +>> Someone's going to have ideas. There's + + align:start position:0% +>> Someone's going to have ideas. There's + + + align:start position:0% +>> Someone's going to have ideas. There's +an idea. + + align:start position:0% +an idea. + + + align:start position:0% +an idea. +lose all the telem + + align:start position:0% + + + + align:start position:0% + +>> losing 100 times. + + align:start position:0% +>> losing 100 times. + + + align:start position:0% +>> losing 100 times. +>> Yeah. + + align:start position:0% + + + + align:start position:0% + +>> Playing on increasingly ridiculous + + align:start position:0% +>> Playing on increasingly ridiculous + + + align:start position:0% +>> Playing on increasingly ridiculous +difficulties with achievements for each + + align:start position:0% +difficulties with achievements for each + + + align:start position:0% +difficulties with achievements for each +four speeds. + + align:start position:0% +four speeds. + + + align:start position:0% +four speeds. +using the speed + + align:start position:0% +using the speed + + + align:start position:0% +using the speed +>> completing a Tetris challenge, which is + + align:start position:0% +>> completing a Tetris challenge, which is + + + align:start position:0% +>> completing a Tetris challenge, which is +presumably some kind of thing where you + + align:start position:0% +presumably some kind of thing where you + + + align:start position:0% +presumably some kind of thing where you +have to drop blocks in the right + + align:start position:0% +have to drop blocks in the right + + + align:start position:0% +have to drop blocks in the right +sequence in order to clear all the + + align:start position:0% +sequence in order to clear all the + + + align:start position:0% +sequence in order to clear all the +lines. Yeah. + + align:start position:0% +lines. Yeah. + + + align:start position:0% +lines. Yeah. +>> Clearing a thousand lines. + + align:start position:0% +>> Clearing a thousand lines. + + + align:start position:0% +>> Clearing a thousand lines. +>> Uh playing invisible mode. + + align:start position:0% +>> Uh playing invisible mode. + + + align:start position:0% +>> Uh playing invisible mode. +>> Uh playing for a certain amount of time + + align:start position:0% +>> Uh playing for a certain amount of time + + + align:start position:0% +>> Uh playing for a certain amount of time +while holding down the down key + + align:start position:0% +while holding down the down key + + + align:start position:0% +while holding down the down key +continuously. + + align:start position:0% + + + + align:start position:0% + +>> I don't know if you only rotating in one + + align:start position:0% +>> I don't know if you only rotating in one + + + align:start position:0% +>> I don't know if you only rotating in one +direction always. I don't know if + + align:start position:0% +direction always. I don't know if + + + align:start position:0% +direction always. I don't know if +someone said that or not. + + align:start position:0% +someone said that or not. + + + align:start position:0% +someone said that or not. +>> Getting 10 achievements in Tetris. + + align:start position:0% + + + + align:start position:0% + +>> Getting every achievement in + + align:start position:0% +>> Getting every achievement in + + + align:start position:0% +>> Getting every achievement in +>> the Tetris. + + align:start position:0% +>> the Tetris. + + + align:start position:0% +>> the Tetris. +>> Oh no. How can you get it? + + align:start position:0% +>> Oh no. How can you get it? + + + align:start position:0% +>> Oh no. How can you get it? +>> It's a paradox. It's impossible. + + align:start position:0% +>> It's a paradox. It's impossible. + + + align:start position:0% +>> It's a paradox. It's impossible. +>> Always having blocks on the far left and + + align:start position:0% +>> Always having blocks on the far left and + + + align:start position:0% +>> Always having blocks on the far left and +on the far right column. + + align:start position:0% +on the far right column. + + + align:start position:0% +on the far right column. +Cool. + + align:start position:0% +Cool. + + + align:start position:0% +Cool. +I think that that had some that had some + + align:start position:0% +I think that that had some that had some + + + align:start position:0% +I think that that had some that had some +decent momentum, but you know, I think + + align:start position:0% +decent momentum, but you know, I think + + + align:start position:0% +decent momentum, but you know, I think +like our mission was accomplished, + + align:start position:0% +like our mission was accomplished, + + + align:start position:0% +like our mission was accomplished, +right? Like we were really only giving + + align:start position:0% +right? Like we were really only giving + + + align:start position:0% +right? Like we were really only giving +one idea at a time because it was only + + align:start position:0% +one idea at a time because it was only + + + align:start position:0% +one idea at a time because it was only +the person who had the ball was talking. + + align:start position:0% +the person who had the ball was talking. + + + align:start position:0% +the person who had the ball was talking. +Um that, you know, probably with a + + align:start position:0% +Um that, you know, probably with a + + + align:start position:0% +Um that, you know, probably with a +little bit more speed and momentum, but + + align:start position:0% +little bit more speed and momentum, but + + + align:start position:0% +little bit more speed and momentum, but +it was nice. Like we did had a little + + align:start position:0% +it was nice. Like we did had a little + + + align:start position:0% +it was nice. Like we did had a little +building on ideas. You know, we're + + align:start position:0% +building on ideas. You know, we're + + + align:start position:0% +building on ideas. You know, we're +starting to get this kind of brainstorm. + + align:start position:0% +starting to get this kind of brainstorm. + + + align:start position:0% +starting to get this kind of brainstorm. +There was still some shyness, which is, + + align:start position:0% +There was still some shyness, which is, + + + align:start position:0% +There was still some shyness, which is, +you know, people have different + + align:start position:0% +you know, people have different + + + align:start position:0% +you know, people have different +personalities, but stop being shy. + + align:start position:0% +personalities, but stop being shy. + + + align:start position:0% +personalities, but stop being shy. +You're allowed to have your different + + align:start position:0% +You're allowed to have your different + + + align:start position:0% +You're allowed to have your different +personalities, but stop it. No. Um, so + + align:start position:0% +personalities, but stop it. No. Um, so + + + align:start position:0% +personalities, but stop it. No. Um, so +that's activity number two. Um, + + align:start position:0% +that's activity number two. Um, + + + align:start position:0% +that's activity number two. Um, +any questions about that process? How do + + align:start position:0% +any questions about that process? How do + + + align:start position:0% +any questions about that process? How do +you feel about it? Any thoughts on it + + align:start position:0% +you feel about it? Any thoughts on it + + + align:start position:0% +you feel about it? Any thoughts on it +before we go on to the next activity? + + align:start position:0% +before we go on to the next activity? + + + align:start position:0% +before we go on to the next activity? +>> All right, next activity. Actually, this + + align:start position:0% +>> All right, next activity. Actually, this + + + align:start position:0% +>> All right, next activity. Actually, this +might be this is our last activity. + + align:start position:0% +might be this is our last activity. + + + align:start position:0% +might be this is our last activity. +Sorry, I said, but there's only three. + + align:start position:0% + + + + align:start position:0% + +>> Um, okay. So, this one is a more formal + + align:start position:0% +>> Um, okay. So, this one is a more formal + + + align:start position:0% +>> Um, okay. So, this one is a more formal +uh a more formal uh brainstorm. And + + align:start position:0% +uh a more formal uh brainstorm. And + + + align:start position:0% +uh a more formal uh brainstorm. And +actually, I screwed up that last one. We + + align:start position:0% +actually, I screwed up that last one. We + + + align:start position:0% +actually, I screwed up that last one. We +didn't have a secretary. So all of those + + align:start position:0% +didn't have a secretary. So all of those + + + align:start position:0% +didn't have a secretary. So all of those +great Tetris ideas are now lost. I can't + + align:start position:0% +great Tetris ideas are now lost. I can't + + + align:start position:0% +great Tetris ideas are now lost. I can't +remember any. + + align:start position:0% +remember any. + + + align:start position:0% +remember any. +>> Oh yes. + + align:start position:0% +>> Oh yes. + + + align:start position:0% +>> Oh yes. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +>> Do we not have that 1950s or something? + + align:start position:0% +>> Do we not have that 1950s or something? + + + align:start position:0% +>> Do we not have that 1950s or something? +>> Let me just get these waxers. + + align:start position:0% +>> Let me just get these waxers. + + + align:start position:0% +>> Let me just get these waxers. +So uh what we're going to do is we're + + align:start position:0% +So uh what we're going to do is we're + + + align:start position:0% +So uh what we're going to do is we're +going to separate the two design teams. + + align:start position:0% +going to separate the two design teams. + + + align:start position:0% +going to separate the two design teams. +Um so it'll just totally be by by + + align:start position:0% +Um so it'll just totally be by by + + + align:start position:0% +Um so it'll just totally be by by +location. We'll just kind of get half of + + align:start position:0% +location. We'll just kind of get half of + + + align:start position:0% +location. We'll just kind of get half of +you over here and half of you over + + align:start position:0% +you over here and half of you over + + + align:start position:0% +you over here and half of you over +there. Um, I want the team to designate + + align:start position:0% +there. Um, I want the team to designate + + + align:start position:0% +there. Um, I want the team to designate +one leader. That's gonna be the person + + align:start position:0% +one leader. That's gonna be the person + + + align:start position:0% +one leader. That's gonna be the person +who's responsible. Clerk for + + align:start position:0% +who's responsible. Clerk for + + + align:start position:0% +who's responsible. Clerk for +facilitating it. Oh, did I say clerk + + align:start position:0% +facilitating it. Oh, did I say clerk + + + align:start position:0% +facilitating it. Oh, did I say clerk +there? A leader and a secretary. It's + + align:start position:0% +there? A leader and a secretary. It's + + + align:start position:0% +there? A leader and a secretary. It's +supposed to be a clerk, leader, and a + + align:start position:0% +supposed to be a clerk, leader, and a + + + align:start position:0% +supposed to be a clerk, leader, and a +secretary. Um, so one person to write + + align:start position:0% +secretary. Um, so one person to write + + + align:start position:0% +secretary. Um, so one person to write +everything down, one person to obviously + + align:start position:0% +everything down, one person to obviously + + + align:start position:0% +everything down, one person to obviously +facilitate and and we're going to do a + + align:start position:0% +facilitate and and we're going to do a + + + align:start position:0% +facilitate and and we're going to do a +we're going to do a kind of a 20 or so + + align:start position:0% +we're going to do a kind of a 20 or so + + + align:start position:0% +we're going to do a kind of a 20 or so +minute uh brainstorm uh for a game + + align:start position:0% +minute uh brainstorm uh for a game + + + align:start position:0% +minute uh brainstorm uh for a game +pitch. Um, what do I mean by game pitch? + + align:start position:0% +pitch. Um, what do I mean by game pitch? + + + align:start position:0% +pitch. Um, what do I mean by game pitch? +It's kind of think of the uh think of + + align:start position:0% +It's kind of think of the uh think of + + + align:start position:0% +It's kind of think of the uh think of +the you're in an elevator with Miiamoto + + align:start position:0% +the you're in an elevator with Miiamoto + + + align:start position:0% +the you're in an elevator with Miiamoto +or you're in an elevator with you know + + align:start position:0% +or you're in an elevator with you know + + + align:start position:0% +or you're in an elevator with you know +Philip Han and uh you have this game + + align:start position:0% +Philip Han and uh you have this game + + + align:start position:0% +Philip Han and uh you have this game +idea that you need to pitch but you're + + align:start position:0% +idea that you need to pitch but you're + + + align:start position:0% +idea that you need to pitch but you're +only going to the 10th floor or so and + + align:start position:0% +only going to the 10th floor or so and + + + align:start position:0% +only going to the 10th floor or so and +so really you've got like 30 seconds a + + align:start position:0% +so really you've got like 30 seconds a + + + align:start position:0% +so really you've got like 30 seconds a +minute 2 minutes maybe um to kind of get + + align:start position:0% +minute 2 minutes maybe um to kind of get + + + align:start position:0% +minute 2 minutes maybe um to kind of get +the core information about this game + + align:start position:0% +the core information about this game + + + align:start position:0% +the core information about this game +app. Um so that can be something like a + + align:start position:0% +app. Um so that can be something like a + + + align:start position:0% +app. Um so that can be something like a +title maybe a tagline for it um any main + + align:start position:0% +title maybe a tagline for it um any main + + + align:start position:0% +title maybe a tagline for it um any main +features uh you might have for it. Um, + + align:start position:0% +features uh you might have for it. Um, + + + align:start position:0% +features uh you might have for it. Um, +of course it would be way too easy or + + align:start position:0% +of course it would be way too easy or + + + align:start position:0% +of course it would be way too easy or +way actually crazy for me to be like any + + align:start position:0% +way actually crazy for me to be like any + + + align:start position:0% +way actually crazy for me to be like any +game at all because there's lots of + + align:start position:0% +game at all because there's lots of + + + align:start position:0% +game at all because there's lots of +different types of games obviously. So + + align:start position:0% +different types of games obviously. So + + + align:start position:0% +different types of games obviously. So +it's going to be a game based on the + + align:start position:0% +it's going to be a game based on the + + + align:start position:0% +it's going to be a game based on the +following constraint. So what I'd like + + align:start position:0% +following constraint. So what I'd like + + + align:start position:0% +following constraint. So what I'd like +to do first before I give you the + + align:start position:0% +to do first before I give you the + + + align:start position:0% +to do first before I give you the +constraint is let's divide ourselves in + + align:start position:0% +constraint is let's divide ourselves in + + + align:start position:0% +constraint is let's divide ourselves in +half. We can kind of draw this like + + align:start position:0% +half. We can kind of draw this like + + + align:start position:0% +half. We can kind of draw this like +imaginary line diagonally dividing the + + align:start position:0% +imaginary line diagonally dividing the + + + align:start position:0% +imaginary line diagonally dividing the +two of you back there and and we'll just + + align:start position:0% +two of you back there and and we'll just + + + align:start position:0% +two of you back there and and we'll just +get we just get one half here. + + align:start position:0% + + + + align:start position:0% + +And once I give you the constraint, + + align:start position:0% +And once I give you the constraint, + + + align:start position:0% +And once I give you the constraint, +we'll actually find a separate room for + + align:start position:0% +we'll actually find a separate room for + + + align:start position:0% +we'll actually find a separate room for +for the other team for one of the teams. + + align:start position:0% +for the other team for one of the teams. + + + align:start position:0% +for the other team for one of the teams. +>> You're stuck on the little wire. + + align:start position:0% +>> You're stuck on the little wire. + + + align:start position:0% +>> You're stuck on the little wire. +>> That's an achievement right there. + + align:start position:0% +>> That's an achievement right there. + + + align:start position:0% +>> That's an achievement right there. +>> I always think that when I'm watching my + + align:start position:0% +>> I always think that when I'm watching my + + + align:start position:0% +>> I always think that when I'm watching my +like + + align:start position:0% +like + + + align:start position:0% +like +think like something happens, + + align:start position:0% +think like something happens, + + + align:start position:0% +think like something happens, +>> especially when someone + + align:start position:0% + + + + align:start position:0% + +you watch this movie. + + align:start position:0% +you watch this movie. + + + align:start position:0% +you watch this movie. +If someone has a piece of paper, they + + align:start position:0% +If someone has a piece of paper, they + + + align:start position:0% +If someone has a piece of paper, they +can down there, right? + + align:start position:0% +can down there, right? + + + align:start position:0% +can down there, right? +>> Yeah, just write out a piece of paper. + + align:start position:0% +>> Yeah, just write out a piece of paper. + + + align:start position:0% +>> Yeah, just write out a piece of paper. +So, um, so these are your teams. You + + align:start position:0% +So, um, so these are your teams. You + + + align:start position:0% +So, um, so these are your teams. You +guys will go into that room. You guys + + align:start position:0% +guys will go into that room. You guys + + + align:start position:0% +guys will go into that room. You guys +stay out here. Um, as soon as I give you + + align:start position:0% +stay out here. Um, as soon as I give you + + + align:start position:0% +stay out here. Um, as soon as I give you +the constraint, designate a designate a + + align:start position:0% +the constraint, designate a designate a + + + align:start position:0% +the constraint, designate a designate a +clerk/ leader, um, leader and a + + align:start position:0% +clerk/ leader, um, leader and a + + + align:start position:0% +clerk/ leader, um, leader and a +secretary, someone to write everything + + align:start position:0% +secretary, someone to write everything + + + align:start position:0% +secretary, someone to write everything +down because our groups are relatively + + align:start position:0% +down because our groups are relatively + + + align:start position:0% +down because our groups are relatively +small, right? We can have the leader and + + align:start position:0% +small, right? We can have the leader and + + + align:start position:0% +small, right? We can have the leader and +the uh the secretary involved in the + + align:start position:0% +the uh the secretary involved in the + + + align:start position:0% +the uh the secretary involved in the +brainstorming process. Please don't be + + align:start position:0% +brainstorming process. Please don't be + + + align:start position:0% +brainstorming process. Please don't be +afraid of contributing. But if you are + + align:start position:0% +afraid of contributing. But if you are + + + align:start position:0% +afraid of contributing. But if you are +designated as this leader, keep in mind + + align:start position:0% +designated as this leader, keep in mind + + + align:start position:0% +designated as this leader, keep in mind +your primary responsibility is + + align:start position:0% +your primary responsibility is + + + align:start position:0% +your primary responsibility is +facilitating the brainstorm. You want to + + align:start position:0% +facilitating the brainstorm. You want to + + + align:start position:0% +facilitating the brainstorm. You want to +make sure it runs smoothly. You want to + + align:start position:0% +make sure it runs smoothly. You want to + + + align:start position:0% +make sure it runs smoothly. You want to +make sure people are not criticizing + + align:start position:0% +make sure people are not criticizing + + + align:start position:0% +make sure people are not criticizing +ideas. You want to make sure that it's + + align:start position:0% +ideas. You want to make sure that it's + + + align:start position:0% +ideas. You want to make sure that it's +going okay. Any questions on this before + + align:start position:0% +going okay. Any questions on this before + + + align:start position:0% +going okay. Any questions on this before +I give you your constraints? + + align:start position:0% +I give you your constraints? + + + align:start position:0% +I give you your constraints? +Everything make sense? All good. Okay. + + align:start position:0% +Everything make sense? All good. Okay. + + + align:start position:0% +Everything make sense? All good. Okay. +Here are the constraints for the game. + + align:start position:0% +Here are the constraints for the game. + + + align:start position:0% +Here are the constraints for the game. +Uh it must have zombies. It must have a + + align:start position:0% +Uh it must have zombies. It must have a + + + align:start position:0% +Uh it must have zombies. It must have a +love. It must be massively multiplayer. + + align:start position:0% +love. It must be massively multiplayer. + + + align:start position:0% +love. It must be massively multiplayer. +Um so that those are the constraints for + + align:start position:0% +Um so that those are the constraints for + + + align:start position:0% +Um so that those are the constraints for +your game. that's what the publisher is + + align:start position:0% +your game. that's what the publisher is + + + align:start position:0% +your game. that's what the publisher is +going to give you money for. Um uh so + + align:start position:0% +going to give you money for. Um uh so + + + align:start position:0% +going to give you money for. Um uh so +you need to develop a pitch a pitch for + + align:start position:0% +you need to develop a pitch a pitch for + + + align:start position:0% +you need to develop a pitch a pitch for +this game idea. Um a title tagline what + + align:start position:0% +this game idea. Um a title tagline what + + + align:start position:0% +this game idea. Um a title tagline what +what have you. All right. So you guys + + align:start position:0% +what have you. All right. So you guys + + + align:start position:0% +what have you. All right. So you guys +we'll we'll take you in this room over + + align:start position:0% +we'll we'll take you in this room over + + + align:start position:0% +we'll we'll take you in this room over +here. You guys stay here. Designate a + + align:start position:0% +here. You guys stay here. Designate a + + + align:start position:0% +here. You guys stay here. Designate a +leader and a secretary and then start + + align:start position:0% +leader and a secretary and then start + + + align:start position:0% +leader and a secretary and then start +brainstorming. + + align:start position:0% +brainstorming. + + + align:start position:0% +brainstorming. +Secretary + + align:start position:0% +Secretary + + + align:start position:0% +Secretary +>> Oh, I love this. It's like I don't want + + align:start position:0% +>> Oh, I love this. It's like I don't want + + + align:start position:0% +>> Oh, I love this. It's like I don't want +to be the leader. I don't want to be the + + align:start position:0% +to be the leader. I don't want to be the + + + align:start position:0% +to be the leader. I don't want to be the +secretary. + + align:start position:0% +secretary. + + + align:start position:0% +secretary. +>> I said I'll do it. Oh + + align:start position:0% +>> I said I'll do it. Oh + + + align:start position:0% +>> I said I'll do it. Oh +secretary. Wait, he wanted to be the + + align:start position:0% +secretary. Wait, he wanted to be the + + + align:start position:0% +secretary. Wait, he wanted to be the +secretary. + + align:start position:0% +secretary. + + + align:start position:0% +secretary. +>> Oh, you're secretary. + + align:start position:0% +>> Oh, you're secretary. + + + align:start position:0% +>> Oh, you're secretary. +>> One of your secretary wants to use + + align:start position:0% +>> One of your secretary wants to use + + + align:start position:0% +>> One of your secretary wants to use +leader. So you get a leader then. + + align:start position:0% +leader. So you get a leader then. + + + align:start position:0% +leader. So you get a leader then. +>> Because you're interested in those game + + align:start position:0% +>> Because you're interested in those game + + + align:start position:0% +>> Because you're interested in those game +and you lost. + + align:start position:0% +and you lost. + + + align:start position:0% +and you lost. +>> Brings up the age question. + + align:start position:0% +>> Brings up the age question. + + + align:start position:0% +>> Brings up the age question. +>> If they're both vampires or they're both + + align:start position:0% +>> If they're both vampires or they're both + + + align:start position:0% +>> If they're both vampires or they're both +zombies, does it count as necessities + + align:start position:0% + + + + align:start position:0% + +manages to have + + align:start position:0% +manages to have + + + align:start position:0% +manages to have +>> encompass all of those except the + + align:start position:0% +>> encompass all of those except the + + + align:start position:0% +>> encompass all of those except the +massively multiplayer parties licensed + + align:start position:0% +massively multiplayer parties licensed + + + align:start position:0% +massively multiplayer parties licensed +title right there. Make it Nazi zombies. + + align:start position:0% +title right there. Make it Nazi zombies. + + + align:start position:0% +title right there. Make it Nazi zombies. +Two Nazi zombie. No, a forbidden love. A + + align:start position:0% +Two Nazi zombie. No, a forbidden love. A + + + align:start position:0% +Two Nazi zombie. No, a forbidden love. A +Nazi zombies in love with like an allied + + align:start position:0% +Nazi zombies in love with like an allied + + + align:start position:0% +Nazi zombies in love with like an allied +zombie + + align:start position:0% +zombie + + + align:start position:0% +zombie +>> and Jewish. + + align:start position:0% +>> and Jewish. + + + align:start position:0% +>> and Jewish. +>> Yes. + + align:start position:0% +>> Yes. + + + align:start position:0% +>> Yes. +>> And then it's So there's two factions. + + align:start position:0% +>> And then it's So there's two factions. + + + align:start position:0% +>> And then it's So there's two factions. +It could be Well, they're all people + + align:start position:0% +It could be Well, they're all people + + + align:start position:0% +It could be Well, they're all people +like online. One group there's like two + + align:start position:0% +like online. One group there's like two + + + align:start position:0% +like online. One group there's like two +factions. There's the ally group and the + + align:start position:0% +factions. There's the ally group and the + + + align:start position:0% +factions. There's the ally group and the +axis group. + + align:start position:0% +axis group. + + + align:start position:0% +axis group. +>> What if What if they're all Nazis? + + align:start position:0% +>> What if What if they're all Nazis? + + + align:start position:0% +>> What if What if they're all Nazis? +>> What What What if there's two factions? + + align:start position:0% +>> What What What if there's two factions? + + + align:start position:0% +>> What What What if there's two factions? +There's the zombies and the humans and + + align:start position:0% +There's the zombies and the humans and + + + align:start position:0% +There's the zombies and the humans and +they're drawn into war because there's a + + align:start position:0% +they're drawn into war because there's a + + + align:start position:0% +they're drawn into war because there's a +love there's a love story between a a + + align:start position:0% +love there's a love story between a a + + + align:start position:0% +love there's a love story between a a +zombie and a human and the leaders get + + align:start position:0% +zombie and a human and the leaders get + + + align:start position:0% +zombie and a human and the leaders get +pissed over this and so we're in war + + align:start position:0% +pissed over this and so we're in war + + + align:start position:0% +pissed over this and so we're in war +because of of like Rome and Julietesque + + align:start position:0% +because of of like Rome and Julietesque + + + align:start position:0% +because of of like Rome and Julietesque +zombie humans. + + align:start position:0% +zombie humans. + + + align:start position:0% +zombie humans. +>> What you're saying is we're having + + align:start position:0% +>> What you're saying is we're having + + + align:start position:0% +>> What you're saying is we're having +intelligent zombies. + + align:start position:0% +intelligent zombies. + + + align:start position:0% +intelligent zombies. +>> Yeah, intelligent zombies. + + align:start position:0% +>> Yeah, intelligent zombies. + + + align:start position:0% +>> Yeah, intelligent zombies. +>> Well, clearly they're semi-intm + + align:start position:0% + + + + align:start position:0% + +Hitler into this though just because + + align:start position:0% +Hitler into this though just because + + + align:start position:0% +Hitler into this though just because +it's Nazis. There must be a zombie + + align:start position:0% +it's Nazis. There must be a zombie + + + align:start position:0% +it's Nazis. There must be a zombie +Hitler. Who said this? + + align:start position:0% +Hitler. Who said this? + + + align:start position:0% +Hitler. Who said this? +>> Wait, what is your name? + + align:start position:0% +>> Wait, what is your name? + + + align:start position:0% +>> Wait, what is your name? +>> Bobby. + + align:start position:0% +>> Bobby. + + + align:start position:0% +>> Bobby. +>> What is your name? + + align:start position:0% +>> What is your name? + + + align:start position:0% +>> What is your name? +>> What is your name? Jason. + + align:start position:0% +>> What is your name? Jason. + + + align:start position:0% +>> What is your name? Jason. +>> Brian. On Jason's idea of is it + + align:start position:0% +>> Brian. On Jason's idea of is it + + + align:start position:0% +>> Brian. On Jason's idea of is it +necrophilia? I I think because there's a + + align:start position:0% +necrophilia? I I think because there's a + + + align:start position:0% +necrophilia? I I think because there's a +love story, the title could be necroilia + + align:start position:0% +love story, the title could be necroilia + + + align:start position:0% +love story, the title could be necroilia +question mark. + + align:start position:0% +question mark. + + + align:start position:0% +question mark. +>> Is it? + + align:start position:0% +>> Is it? + + + align:start position:0% +>> Is it? +>> Is it nec? + + align:start position:0% +>> Is it nec? + + + align:start position:0% +>> Is it nec? +>> Is it necroilia? + + align:start position:0% +>> Is it necroilia? + + + align:start position:0% +>> Is it necroilia? +>> Probably. Probably. + + align:start position:0% +>> Probably. Probably. + + + align:start position:0% +>> Probably. Probably. +>> Is it I like it as a love story, but is + + align:start position:0% +>> Is it I like it as a love story, but is + + + align:start position:0% +>> Is it I like it as a love story, but is +it a sex story? + + align:start position:0% + + + + align:start position:0% + +>> So, wait. How about this? + + align:start position:0% +>> So, wait. How about this? + + + align:start position:0% +>> So, wait. How about this? +>> Or maybe even zombie strippers that fall + + align:start position:0% +>> Or maybe even zombie strippers that fall + + + align:start position:0% +>> Or maybe even zombie strippers that fall +in love with. + + align:start position:0% +in love with. + + + align:start position:0% +in love with. +>> Have you seen Zombie Strippers? + + align:start position:0% +>> Have you seen Zombie Strippers? + + + align:start position:0% +>> Have you seen Zombie Strippers? +>> No. + + align:start position:0% +>> No. + + + align:start position:0% +>> No. +>> It's a terrible, wonderful, terrible + + align:start position:0% +>> It's a terrible, wonderful, terrible + + + align:start position:0% +>> It's a terrible, wonderful, terrible +movie. + + align:start position:0% +movie. + + + align:start position:0% +movie. +>> I'll watch it. + + align:start position:0% +>> I'll watch it. + + + align:start position:0% +>> I'll watch it. +>> You should not. Should + + align:start position:0% + + + + align:start position:0% + +>> um So the actually how about we have the + + align:start position:0% +>> um So the actually how about we have the + + + align:start position:0% +>> um So the actually how about we have the +zombies as the good guys? That way like + + align:start position:0% +zombies as the good guys? That way like + + + align:start position:0% +zombies as the good guys? That way like +the allies are trying to like make a + + align:start position:0% +the allies are trying to like make a + + + align:start position:0% +the allies are trying to like make a +weapon that will destroy like half the + + align:start position:0% +weapon that will destroy like half the + + + align:start position:0% +weapon that will destroy like half the +world and the zombies are like, "No, + + align:start position:0% +world and the zombies are like, "No, + + + align:start position:0% +world and the zombies are like, "No, +that will be bad. Let's make everyone + + align:start position:0% +that will be bad. Let's make everyone + + + align:start position:0% +that will be bad. Let's make everyone +else obvious so they agree with us." + + align:start position:0% +else obvious so they agree with us." + + + align:start position:0% +else obvious so they agree with us." +Well, + + align:start position:0% +Well, + + + align:start position:0% +Well, +>> what if what if + + align:start position:0% +>> what if what if + + + align:start position:0% +>> what if what if +>> what if you're just a zombie and + + align:start position:0% +>> what if you're just a zombie and + + + align:start position:0% +>> what if you're just a zombie and +everyone is trying to kill you, so you + + align:start position:0% +everyone is trying to kill you, so you + + + align:start position:0% +everyone is trying to kill you, so you +want to make everyone zombies so the + + align:start position:0% +want to make everyone zombies so the + + + align:start position:0% +want to make everyone zombies so the +world will be peaceful and happy. + + align:start position:0% +world will be peaceful and happy. + + + align:start position:0% +world will be peaceful and happy. +>> You want everyone to love you. + + align:start position:0% +>> You want everyone to love you. + + + align:start position:0% +>> You want everyone to love you. +>> Yeah, + + align:start position:0% +>> Yeah, + + + align:start position:0% +>> Yeah, +>> I like that a lot. + + align:start position:0% +>> I like that a lot. + + + align:start position:0% +>> I like that a lot. +>> And that's then + + align:start position:0% +>> And that's then + + + align:start position:0% +>> And that's then +even better. Love zombies. Like, who + + align:start position:0% +even better. Love zombies. Like, who + + + align:start position:0% +even better. Love zombies. Like, who +says they have to be undead? They can be + + align:start position:0% +says they have to be undead? They can be + + + align:start position:0% +says they have to be undead? They can be +infected by emotion. + + align:start position:0% +infected by emotion. + + + align:start position:0% +infected by emotion. +>> That's a tagline right there. + + align:start position:0% +>> That's a tagline right there. + + + align:start position:0% +>> That's a tagline right there. +>> Nudest zombies. What if what if like 95% + + align:start position:0% +>> Nudest zombies. What if what if like 95% + + + align:start position:0% +>> Nudest zombies. What if what if like 95% +of the world is zombie and so then the + + align:start position:0% +of the world is zombie and so then the + + + align:start position:0% +of the world is zombie and so then the +weird creatures that are like scary are + + align:start position:0% +weird creatures that are like scary are + + + align:start position:0% +weird creatures that are like scary are +the humans and they're like sentient + + align:start position:0% +the humans and they're like sentient + + + align:start position:0% +the humans and they're like sentient +they do weird things but the zombies all + + align:start position:0% +they do weird things but the zombies all + + + align:start position:0% +they do weird things but the zombies all +are happy and love each other. + + align:start position:0% +are happy and love each other. + + + align:start position:0% +are happy and love each other. +>> Maybe the humans have the love disease. + + align:start position:0% +>> Maybe the humans have the love disease. + + + align:start position:0% +>> Maybe the humans have the love disease. +>> They're trying to zombies + + align:start position:0% +>> They're trying to zombies + + + align:start position:0% +>> They're trying to zombies +like they're infecting zombies with + + align:start position:0% +like they're infecting zombies with + + + align:start position:0% +like they're infecting zombies with +love. + + align:start position:0% + + + + align:start position:0% + +>> So then each person would be I either + + align:start position:0% +>> So then each person would be I either + + + align:start position:0% +>> So then each person would be I either +start as a zombie or a human. They have + + align:start position:0% +start as a zombie or a human. They have + + + align:start position:0% +start as a zombie or a human. They have +to complete a bunch of little tasks + + align:start position:0% +to complete a bunch of little tasks + + + align:start position:0% +to complete a bunch of little tasks +before they can come, you know, and they + + align:start position:0% +before they can come, you know, and they + + + align:start position:0% +before they can come, you know, and they +like play challenges against each other. + + align:start position:0% +like play challenges against each other. + + + align:start position:0% +like play challenges against each other. +So be like zombie against zombie and one + + align:start position:0% +So be like zombie against zombie and one + + + align:start position:0% +So be like zombie against zombie and one +of them is infected, one of them isn't. + + align:start position:0% +of them is infected, one of them isn't. + + + align:start position:0% +of them is infected, one of them isn't. +>> So humans can infect zombies with blood + + align:start position:0% +>> So humans can infect zombies with blood + + + align:start position:0% +>> So humans can infect zombies with blood +that makes them not zombies. + + align:start position:0% +that makes them not zombies. + + + align:start position:0% +that makes them not zombies. +>> What if no zombies? What what if what if + + align:start position:0% +>> What if no zombies? What what if what if + + + align:start position:0% +>> What if no zombies? What what if what if +there's a dynamic what what if there's a + + align:start position:0% +there's a dynamic what what if there's a + + + align:start position:0% +there's a dynamic what what if there's a +dynamic between so there's there's two + + align:start position:0% +dynamic between so there's there's two + + + align:start position:0% +dynamic between so there's there's two +factions zombies and humans and every + + align:start position:0% +factions zombies and humans and every + + + align:start position:0% +factions zombies and humans and every +player is given a match and in this + + align:start position:0% +player is given a match and in this + + + align:start position:0% +player is given a match and in this +massive multiplayer world that one of + + align:start position:0% +massive multiplayer world that one of + + + align:start position:0% +massive multiplayer world that one of +their main objectives is to find their + + align:start position:0% +their main objectives is to find their + + + align:start position:0% +their main objectives is to find their +match who's in the opposing faction + + align:start position:0% +match who's in the opposing faction + + + align:start position:0% +match who's in the opposing faction +buried deep among hostile hordes of + + align:start position:0% +buried deep among hostile hordes of + + + align:start position:0% +buried deep among hostile hordes of +either humans or zombies find them and + + align:start position:0% +either humans or zombies find them and + + + align:start position:0% +either humans or zombies find them and +like live happily ever after together + + align:start position:0% +like live happily ever after together + + + align:start position:0% +like live happily ever after together +>> and become either zombies or humans + + align:start position:0% +>> and become either zombies or humans + + + align:start position:0% +>> and become either zombies or humans +together. + + align:start position:0% +together. + + + align:start position:0% +together. +>> Correct. + + align:start position:0% +>> Correct. + + + align:start position:0% +>> Correct. +>> But love zombies + + align:start position:0% +>> But love zombies + + + align:start position:0% +>> But love zombies +>> find a cure or just get bitten + + align:start position:0% +>> find a cure or just get bitten + + + align:start position:0% +>> find a cure or just get bitten +>> and become love zombies. + + align:start position:0% +>> and become love zombies. + + + align:start position:0% +>> and become love zombies. +>> Love zombies. + + align:start position:0% +>> Love zombies. + + + align:start position:0% +>> Love zombies. +>> Love zombies. + + align:start position:0% + + + + align:start position:0% + +Ask the question. Is there truly a + + align:start position:0% +Ask the question. Is there truly a + + + align:start position:0% +Ask the question. Is there truly a +difference between being in love and + + align:start position:0% +difference between being in love and + + + align:start position:0% +difference between being in love and +being undead? + + align:start position:0% +being undead? + + + align:start position:0% +being undead? +>> That's a great tagline. + + align:start position:0% +>> That's a great tagline. + + + align:start position:0% +>> That's a great tagline. +>> Maybe some task. + + align:start position:0% + + + + align:start position:0% + +>> What's even more blind? Having your eyes + + align:start position:0% +>> What's even more blind? Having your eyes + + + align:start position:0% +>> What's even more blind? Having your eyes +guided out by a zombie or being in love? + + align:start position:0% +guided out by a zombie or being in love? + + + align:start position:0% +guided out by a zombie or being in love? +>> So, so then we can draw it into not the + + align:start position:0% +>> So, so then we can draw it into not the + + + align:start position:0% +>> So, so then we can draw it into not the +actual Nazi zombie game. + + align:start position:0% +actual Nazi zombie game. + + + align:start position:0% +actual Nazi zombie game. +>> Maybe the Nazi zombies from the other + + align:start position:0% +>> Maybe the Nazi zombies from the other + + + align:start position:0% +>> Maybe the Nazi zombies from the other +point of view. So, they're just trying + + align:start position:0% +point of view. So, they're just trying + + + align:start position:0% +point of view. So, they're just trying +to have love and and the humans are + + align:start position:0% +to have love and and the humans are + + + align:start position:0% +to have love and and the humans are +trying to kill them. + + align:start position:0% +trying to kill them. + + + align:start position:0% +trying to kill them. +Um, + + align:start position:0% +Um, + + + align:start position:0% +Um, +>> wait. Are we having Nazis? + + align:start position:0% +>> wait. Are we having Nazis? + + + align:start position:0% +>> wait. Are we having Nazis? +>> We can. + + align:start position:0% +>> We can. + + + align:start position:0% +>> We can. +>> Some of the ideas can include Nazis and + + align:start position:0% +>> Some of the ideas can include Nazis and + + + align:start position:0% +>> Some of the ideas can include Nazis and +some of them can't and we can decide. + + align:start position:0% +some of them can't and we can decide. + + + align:start position:0% +some of them can't and we can decide. +>> Should we be getting to the point of + + align:start position:0% +>> Should we be getting to the point of + + + align:start position:0% +>> Should we be getting to the point of +judgment towards the end of the thing so + + align:start position:0% +judgment towards the end of the thing so + + + align:start position:0% +judgment towards the end of the thing so +we can finalize a pitch in a thing or + + align:start position:0% +we can finalize a pitch in a thing or + + + align:start position:0% +we can finalize a pitch in a thing or +whatever? Just just come up + + align:start position:0% +whatever? Just just come up + + + align:start position:0% +whatever? Just just come up +>> with just brainstorming. That's awesome. + + align:start position:0% +>> with just brainstorming. That's awesome. + + + align:start position:0% +>> with just brainstorming. That's awesome. +>> Yeah, it's just fun. + + align:start position:0% +>> Yeah, it's just fun. + + + align:start position:0% +>> Yeah, it's just fun. +>> Yeah. Yeah. + + align:start position:0% +>> Yeah. Yeah. + + + align:start position:0% +>> Yeah. Yeah. +>> How about um the player is a human + + align:start position:0% +>> How about um the player is a human + + + align:start position:0% +>> How about um the player is a human +fighting against the zombies and you + + align:start position:0% +fighting against the zombies and you + + + align:start position:0% +fighting against the zombies and you +have some kind of companion may or may + + align:start position:0% +have some kind of companion may or may + + + align:start position:0% +have some kind of companion may or may +not be a cube but that accompanies you + + align:start position:0% +not be a cube but that accompanies you + + + align:start position:0% +not be a cube but that accompanies you +on your journey to defeat the zombies. + + align:start position:0% +on your journey to defeat the zombies. + + + align:start position:0% +on your journey to defeat the zombies. +>> So companion cube I like better. + + align:start position:0% +>> So companion cube I like better. + + + align:start position:0% +>> So companion cube I like better. +>> Do plants love each other? + + align:start position:0% +>> Do plants love each other? + + + align:start position:0% +>> Do plants love each other? +>> That way that is a heart like that's + + align:start position:0% +>> That way that is a heart like that's + + + align:start position:0% +>> That way that is a heart like that's +like a love story between you and your + + align:start position:0% +like a love story between you and your + + + align:start position:0% +like a love story between you and your +cube. + + align:start position:0% +cube. + + + align:start position:0% +cube. +>> But can the can the cube become a + + align:start position:0% +>> But can the can the cube become a + + + align:start position:0% +>> But can the can the cube become a +zombie? + + align:start position:0% +zombie? + + + align:start position:0% +zombie? +>> Yes. + + align:start position:0% +>> Yes. + + + align:start position:0% +>> Yes. +>> I mean it could be a person like Left + + align:start position:0% +>> I mean it could be a person like Left + + + align:start position:0% +>> I mean it could be a person like Left +for Dead. like four people against all + + align:start position:0% +for Dead. like four people against all + + + align:start position:0% +for Dead. like four people against all +the zombies that they're always + + align:start position:0% + + + + align:start position:0% + +>> or witches. Maybe you're trying to get + + align:start position:0% +>> or witches. Maybe you're trying to get + + + align:start position:0% +>> or witches. Maybe you're trying to get +>> the love story is you and the witch + + align:start position:0% +>> the love story is you and the witch + + + align:start position:0% +>> the love story is you and the witch +consuming the thing and like + + align:start position:0% +consuming the thing and like + + + align:start position:0% +consuming the thing and like +>> what if so all players play zombies and + + align:start position:0% +>> what if so all players play zombies and + + + align:start position:0% +>> what if so all players play zombies and +most missions are stuff like you have to + + align:start position:0% +most missions are stuff like you have to + + + align:start position:0% +most missions are stuff like you have to +infect a city and just run around like + + align:start position:0% +infect a city and just run around like + + + align:start position:0% +infect a city and just run around like +binding people into the entire city that + + align:start position:0% +binding people into the entire city that + + + align:start position:0% +binding people into the entire city that +you've like conquered or turned into + + align:start position:0% +you've like conquered or turned into + + + align:start position:0% +you've like conquered or turned into +zombified. Your ultimate goal is that + + align:start position:0% +zombified. Your ultimate goal is that + + + align:start position:0% +zombified. Your ultimate goal is that +your girlfriend from back when you were + + align:start position:0% +your girlfriend from back when you were + + + align:start position:0% +your girlfriend from back when you were +human or your boyfriend from back when + + align:start position:0% +human or your boyfriend from back when + + + align:start position:0% +human or your boyfriend from back when +you were human is at some place and you + + align:start position:0% +you were human is at some place and you + + + align:start position:0% +you were human is at some place and you +want to infect all cities until you can + + align:start position:0% +want to infect all cities until you can + + + align:start position:0% +want to infect all cities until you can +get there and then infect her so that + + align:start position:0% +get there and then infect her so that + + + align:start position:0% +get there and then infect her so that +you guys can live happily ever after. + + align:start position:0% +you guys can live happily ever after. + + + align:start position:0% +you guys can live happily ever after. +>> A you could also + + align:start position:0% +>> A you could also + + + align:start position:0% +>> A you could also +>> also building on the idea of being + + align:start position:0% +>> also building on the idea of being + + + align:start position:0% +>> also building on the idea of being +zombies trying to infect cities. + + align:start position:0% +zombies trying to infect cities. + + + align:start position:0% +zombies trying to infect cities. +>> Oh god, + + align:start position:0% +>> Oh god, + + + align:start position:0% +>> Oh god, +>> you are zombies uh with Cupid's love + + align:start position:0% +>> you are zombies uh with Cupid's love + + + align:start position:0% +>> you are zombies uh with Cupid's love +arrows + + align:start position:0% +arrows + + + align:start position:0% +arrows +>> trying to infect the entire city with + + align:start position:0% +>> trying to infect the entire city with + + + align:start position:0% +>> trying to infect the entire city with +love at which point no no productivity + + align:start position:0% +love at which point no no productivity + + + align:start position:0% +love at which point no no productivity +is all gone in the city. zombie with + + align:start position:0% +is all gone in the city. zombie with + + + align:start position:0% +is all gone in the city. zombie with +love arrows infecting people. + + align:start position:0% +love arrows infecting people. + + + align:start position:0% +love arrows infecting people. +>> It could be set in the 1950s where + + align:start position:0% +>> It could be set in the 1950s where + + + align:start position:0% +>> It could be set in the 1950s where +everyone's like trying to be productive + + align:start position:0% +everyone's like trying to be productive + + + align:start position:0% +everyone's like trying to be productive +and not love each other. + + align:start position:0% +and not love each other. + + + align:start position:0% +and not love each other. +>> No, what if what if you build along the + + align:start position:0% +>> No, what if what if you build along the + + + align:start position:0% +>> No, what if what if you build along the +lines of, you know, having to infect the + + align:start position:0% +lines of, you know, having to infect the + + + align:start position:0% +lines of, you know, having to infect the +city, but you have to do that. One + + align:start position:0% +city, but you have to do that. One + + + align:start position:0% +city, but you have to do that. One +zombie can't infect an entire city, + + align:start position:0% +zombie can't infect an entire city, + + + align:start position:0% +zombie can't infect an entire city, +right? So, you have to like ally with + + align:start position:0% +right? So, you have to like ally with + + + align:start position:0% +right? So, you have to like ally with +other zombies, but they're like + + align:start position:0% +other zombies, but they're like + + + align:start position:0% +other zombies, but they're like +different factions of zombies. Kind of + + align:start position:0% +different factions of zombies. Kind of + + + align:start position:0% +different factions of zombies. Kind of +like two zombie mob families, right, + + align:start position:0% +like two zombie mob families, right, + + + align:start position:0% +like two zombie mob families, right, +that are trying to infect. They have two + + align:start position:0% +that are trying to infect. They have two + + + align:start position:0% +that are trying to infect. They have two +different, you know, varieties of this + + align:start position:0% +different, you know, varieties of this + + + align:start position:0% +different, you know, varieties of this +lovely in + + align:start position:0% +lovely in + + + align:start position:0% +lovely in +>> Oh, wait. Could there be like a drug + + align:start position:0% +>> Oh, wait. Could there be like a drug + + + align:start position:0% +>> Oh, wait. Could there be like a drug +trade? So like the like they have to + + align:start position:0% +trade? So like the like they have to + + + align:start position:0% +trade? So like the like they have to +infect people with like a certain drug. + + align:start position:0% +infect people with like a certain drug. + + + align:start position:0% +infect people with like a certain drug. +So it's like a drug war as well. And + + align:start position:0% +So it's like a drug war as well. And + + + align:start position:0% +So it's like a drug war as well. And +this the three swords good swords are + + align:start position:0% +this the three swords good swords are + + + align:start position:0% +this the three swords good swords are +cool. + + align:start position:0% +cool. + + + align:start position:0% +cool. +>> Zombie. + + align:start position:0% +>> Zombie. + + + align:start position:0% +>> Zombie. +>> What if + + align:start position:0% +>> What if + + + align:start position:0% +>> What if +>> what if when you have a zombie virus + + align:start position:0% +>> what if when you have a zombie virus + + + align:start position:0% +>> what if when you have a zombie virus +instead of wanting to eat people you are + + align:start position:0% +instead of wanting to eat people you are + + + align:start position:0% +instead of wanting to eat people you are +overcome with an urge to passionately + + align:start position:0% +overcome with an urge to passionately + + + align:start position:0% +overcome with an urge to passionately +make out with them. And if you make out + + align:start position:0% +make out with them. And if you make out + + + align:start position:0% +make out with them. And if you make out +with somebody then they turn into a love + + align:start position:0% +with somebody then they turn into a love + + + align:start position:0% +with somebody then they turn into a love +zombie too. And so there's no like + + align:start position:0% +zombie too. And so there's no like + + + align:start position:0% +zombie too. And so there's no like +decomposition going on so much as there + + align:start position:0% +decomposition going on so much as there + + + align:start position:0% +decomposition going on so much as there +is like hordes of people running through + + align:start position:0% +is like hordes of people running through + + + align:start position:0% +is like hordes of people running through +streets trying to passionately make out + + align:start position:0% +streets trying to passionately make out + + + align:start position:0% +streets trying to passionately make out +with each other. So wait + + align:start position:0% +with each other. So wait + + + align:start position:0% +with each other. So wait +>> being decaying and like decrepit. W + + align:start position:0% +>> being decaying and like decrepit. W + + + align:start position:0% +>> being decaying and like decrepit. W +zombies suddenly become very attractive. + + align:start position:0% +zombies suddenly become very attractive. + + + align:start position:0% +zombies suddenly become very attractive. +So you + + align:start position:0% +So you + + + align:start position:0% +So you +>> wait and they start like they start like + + align:start position:0% +>> wait and they start like they start like + + + align:start position:0% +>> wait and they start like they start like +taking care of their appearance and + + align:start position:0% +taking care of their appearance and + + + align:start position:0% +taking care of their appearance and +stuff. + + align:start position:0% +stuff. + + + align:start position:0% +stuff. +>> So when is limit is there I'm well after + + align:start position:0% +>> So when is limit is there I'm well after + + + align:start position:0% +>> So when is limit is there I'm well after +the zombies make out. + + align:start position:0% +the zombies make out. + + + align:start position:0% +the zombies make out. +>> What what's next? + + align:start position:0% +>> What what's next? + + + align:start position:0% +>> What what's next? +>> Well they get for + + align:start position:0% +>> Well they get for + + + align:start position:0% +>> Well they get for +Okay. So what if we just like make a + + align:start position:0% +Okay. So what if we just like make a + + + align:start position:0% +Okay. So what if we just like make a +like World of Warcraft type of MMO but + + align:start position:0% +like World of Warcraft type of MMO but + + + align:start position:0% +like World of Warcraft type of MMO but +every player player humans you have a + + align:start position:0% +every player player humans you have a + + + align:start position:0% +every player player humans you have a +zombie companion + + align:start position:0% + + + + align:start position:0% + +>> pet zombie? + + align:start position:0% +>> pet zombie? + + + align:start position:0% +>> pet zombie? +>> Yeah zombie + + align:start position:0% +>> Yeah zombie + + + align:start position:0% +>> Yeah zombie +peties + + align:start position:0% + + + + align:start position:0% + +>> no but they had + + align:start position:0% +>> no but they had + + + align:start position:0% +>> no but they had +>> the dead Pokemon. No, they had a pet as + + align:start position:0% +>> the dead Pokemon. No, they had a pet as + + + align:start position:0% +>> the dead Pokemon. No, they had a pet as +a pet. + + align:start position:0% +a pet. + + + align:start position:0% +a pet. +>> I think it's called + + align:start position:0% +>> I think it's called + + + align:start position:0% +>> I think it's called +>> Ph. It's like I think + + align:start position:0% +>> Ph. It's like I think + + + align:start position:0% +>> Ph. It's like I think +>> it's a movie called Phto. + + align:start position:0% +>> it's a movie called Phto. + + + align:start position:0% +>> it's a movie called Phto. +>> I've not seen it, but + + align:start position:0% +>> I've not seen it, but + + + align:start position:0% +>> I've not seen it, but +>> I've seen the trailer. + + align:start position:0% +>> I've seen the trailer. + + + align:start position:0% +>> I've seen the trailer. +>> So, what if you have to fight like with + + align:start position:0% +>> So, what if you have to fight like with + + + align:start position:0% +>> So, what if you have to fight like with +Pokemon zombies + + align:start position:0% +Pokemon zombies + + + align:start position:0% +Pokemon zombies +different powerups? + + align:start position:0% +different powerups? + + + align:start position:0% +different powerups? +>> Different kinds of zombies like uh like + + align:start position:0% +>> Different kinds of zombies like uh like + + + align:start position:0% +>> Different kinds of zombies like uh like +Left 4 Dead. There's, you know, the big + + align:start position:0% +Left 4 Dead. There's, you know, the big + + + align:start position:0% +Left 4 Dead. There's, you know, the big +fat ones that like vomit and you know, + + align:start position:0% +fat ones that like vomit and you know, + + + align:start position:0% +fat ones that like vomit and you know, +>> spitters. I hate spitters. But smokers. + + align:start position:0% +>> spitters. I hate spitters. But smokers. + + + align:start position:0% +>> spitters. I hate spitters. But smokers. +Smokers are the worst. + + align:start position:0% +Smokers are the worst. + + + align:start position:0% +Smokers are the worst. +>> Well, instead of pyro, you have blood + + align:start position:0% +>> Well, instead of pyro, you have blood + + + align:start position:0% +>> Well, instead of pyro, you have blood +potions. Man, he said smokers are the + + align:start position:0% +potions. Man, he said smokers are the + + + align:start position:0% +potions. Man, he said smokers are the +worst. That sounds like a dating s. + + align:start position:0% +worst. That sounds like a dating s. + + + align:start position:0% +worst. That sounds like a dating s. +I do I like the Pokemon idea. So, you + + align:start position:0% +I do I like the Pokemon idea. So, you + + + align:start position:0% +I do I like the Pokemon idea. So, you +can have um instead of like you're + + align:start position:0% +can have um instead of like you're + + + align:start position:0% +can have um instead of like you're +humans, but you just have to capture all + + align:start position:0% +humans, but you just have to capture all + + + align:start position:0% +humans, but you just have to capture all +the poke like different types of zombies + + align:start position:0% +the poke like different types of zombies + + + align:start position:0% +the poke like different types of zombies +and then you fight other people with + + align:start position:0% +and then you fight other people with + + + align:start position:0% +and then you fight other people with +their zombies and it's like match for + + align:start position:0% +their zombies and it's like match for + + + align:start position:0% +their zombies and it's like match for +zombie versus zombie. + + align:start position:0% +zombie versus zombie. + + + align:start position:0% +zombie versus zombie. +What if the love story is not for the + + align:start position:0% +What if the love story is not for the + + + align:start position:0% +What if the love story is not for the +player, but is in is in the story of the + + align:start position:0% +player, but is in is in the story of the + + + align:start position:0% +player, but is in is in the story of the +game in that the reason that you're + + align:start position:0% +game in that the reason that you're + + + align:start position:0% +game in that the reason that you're +waging war at the moment is because + + align:start position:0% +waging war at the moment is because + + + align:start position:0% +waging war at the moment is because +you're trying to steal a cure to + + align:start position:0% +you're trying to steal a cure to + + + align:start position:0% +you're trying to steal a cure to +zombieism because your fearless leader + + align:start position:0% +zombieism because your fearless leader + + + align:start position:0% +zombieism because your fearless leader +20 ranks up, you're president of + + align:start position:0% +20 ranks up, you're president of + + + align:start position:0% +20 ranks up, you're president of +whatever's girlfriend has been zombified + + align:start position:0% +whatever's girlfriend has been zombified + + + align:start position:0% +whatever's girlfriend has been zombified +or his wife has been zombified. And so + + align:start position:0% +or his wife has been zombified. And so + + + align:start position:0% +or his wife has been zombified. And so +the whole game, you're all the means in + + align:start position:0% +the whole game, you're all the means in + + + align:start position:0% +the whole game, you're all the means in +a quest to to try to find this cure, but + + align:start position:0% +a quest to to try to find this cure, but + + + align:start position:0% +a quest to to try to find this cure, but +you don't realize you're trying to find + + align:start position:0% +you don't realize you're trying to find + + + align:start position:0% +you don't realize you're trying to find +a cure for it's not for like your use or + + align:start position:0% +a cure for it's not for like your use or + + + align:start position:0% +a cure for it's not for like your use or +your girlfriend's use or whatever of + + align:start position:0% +your girlfriend's use or whatever of + + + align:start position:0% +your girlfriend's use or whatever of +people you love. It's for your leaders. + + align:start position:0% +people you love. It's for your leaders. + + + align:start position:0% +people you love. It's for your leaders. +>> And what if she is actually the leader + + align:start position:0% +>> And what if she is actually the leader + + + align:start position:0% +>> And what if she is actually the leader +of the zombies and + + align:start position:0% +of the zombies and + + + align:start position:0% +of the zombies and +>> Oh crap. + + align:start position:0% + + + + align:start position:0% + +>> What if the zombies are aliens? + + align:start position:0% +>> What if the zombies are aliens? + + + align:start position:0% +>> What if the zombies are aliens? +>> Zombie aliens. + + align:start position:0% +>> Zombie aliens. + + + align:start position:0% +>> Zombie aliens. +>> The blood. What if the zombies are + + align:start position:0% +>> The blood. What if the zombies are + + + align:start position:0% +>> The blood. What if the zombies are +ninjas? + + align:start position:0% +ninjas? + + + align:start position:0% +ninjas? +>> Yes. + + align:start position:0% +>> Yes. + + + align:start position:0% +>> Yes. +>> You can learn a lot. + + align:start position:0% +>> You can learn a lot. + + + align:start position:0% +>> You can learn a lot. +>> Combine the Pokemon of zombie ID with + + align:start position:0% +>> Combine the Pokemon of zombie ID with + + + align:start position:0% +>> Combine the Pokemon of zombie ID with +like the Sims where you like have a + + align:start position:0% +like the Sims where you like have a + + + align:start position:0% +like the Sims where you like have a +zombie that's under your control and + + align:start position:0% +zombie that's under your control and + + + align:start position:0% +zombie that's under your control and +you're trying to like teach your zombie + + align:start position:0% +you're trying to like teach your zombie + + + align:start position:0% +you're trying to like teach your zombie +to love and like maybe you're a + + align:start position:0% +to love and like maybe you're a + + + align:start position:0% +to love and like maybe you're a +different avatar. like a human avatar + + align:start position:0% +different avatar. like a human avatar + + + align:start position:0% +different avatar. like a human avatar +and you go through quests where you like + + align:start position:0% +and you go through quests where you like + + + align:start position:0% +and you go through quests where you like +take your zombie places and teach your + + align:start position:0% +take your zombie places and teach your + + + align:start position:0% +take your zombie places and teach your +zombie things + + align:start position:0% +zombie things + + + align:start position:0% +zombie things +>> and not to bite people and + + align:start position:0% +>> and not to bite people and + + + align:start position:0% +>> and not to bite people and +>> yeah exactly like I don't I don't know + + align:start position:0% +>> yeah exactly like I don't I don't know + + + align:start position:0% +>> yeah exactly like I don't I don't know +train your zombie + + align:start position:0% +train your zombie + + + align:start position:0% +train your zombie +>> maybe have so with the whole thing with + + align:start position:0% +>> maybe have so with the whole thing with + + + align:start position:0% +>> maybe have so with the whole thing with +the ninja pir ninja zombies might not + + align:start position:0% +the ninja pir ninja zombies might not + + + align:start position:0% +the ninja pir ninja zombies might not +have pirate pirates as well pirate + + align:start position:0% +have pirate pirates as well pirate + + + align:start position:0% +have pirate pirates as well pirate +zombies maybe + + align:start position:0% +zombies maybe + + + align:start position:0% +zombies maybe +>> pirate versus ninja + + align:start position:0% +>> pirate versus ninja + + + align:start position:0% +>> pirate versus ninja +>> zombies + + align:start position:0% +>> zombies + + + align:start position:0% +>> zombies +>> zombie edition special edition + + align:start position:0% +>> zombie edition special edition + + + align:start position:0% +>> zombie edition special edition +>> in space wrapped in bacon + + align:start position:0% +>> in space wrapped in bacon + + + align:start position:0% +>> in space wrapped in bacon +>> yes + + align:start position:0% +>> yes + + + align:start position:0% +>> yes +>> time traveling zombies + + align:start position:0% +>> time traveling zombies + + + align:start position:0% +>> time traveling zombies +I would be a great game to make just + + align:start position:0% +I would be a great game to make just + + + align:start position:0% +I would be a great game to make just +like pirate zombies versus ninja zombies + + align:start position:0% +like pirate zombies versus ninja zombies + + + align:start position:0% +like pirate zombies versus ninja zombies +in space wrapped in bacon and just make + + align:start position:0% +in space wrapped in bacon and just make + + + align:start position:0% +in space wrapped in bacon and just make +that game great. + + align:start position:0% +that game great. + + + align:start position:0% +that game great. +>> So is it necia probably + + align:start position:0% + + + + align:start position:0% + +>> pirate edition the ninja. + + align:start position:0% +>> pirate edition the ninja. + + + align:start position:0% +>> pirate edition the ninja. +>> So maybe you should divide into little + + align:start position:0% +>> So maybe you should divide into little + + + align:start position:0% +>> So maybe you should divide into little +sub brainstorms for like a name tagline + + align:start position:0% +sub brainstorms for like a name tagline + + + align:start position:0% +sub brainstorms for like a name tagline +all that. Do we as a name do we have + + align:start position:0% +all that. Do we as a name do we have + + + align:start position:0% +all that. Do we as a name do we have +anyone more brainstorming? + + align:start position:0% +anyone more brainstorming? + + + align:start position:0% +anyone more brainstorming? +I think we should figure out like a + + align:start position:0% +I think we should figure out like a + + + align:start position:0% +I think we should figure out like a +mechanic that works. So far, we have a + + align:start position:0% +mechanic that works. So far, we have a + + + align:start position:0% +mechanic that works. So far, we have a +lot of ideas about like what the game + + align:start position:0% +lot of ideas about like what the game + + + align:start position:0% +lot of ideas about like what the game +world is. We have no idea like how you + + align:start position:0% +world is. We have no idea like how you + + + align:start position:0% +world is. We have no idea like how you +play the game. So, maybe more + + align:start position:0% +play the game. So, maybe more + + + align:start position:0% +play the game. So, maybe more +brainstorming on that then. + + align:start position:0% +brainstorming on that then. + + + align:start position:0% +brainstorming on that then. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> It's massive multiplayer. ones working + + align:start position:0% +>> It's massive multiplayer. ones working + + + align:start position:0% +>> It's massive multiplayer. ones working +such as typical WoW style RPG, typical + + align:start position:0% +such as typical WoW style RPG, typical + + + align:start position:0% +such as typical WoW style RPG, typical +passive player FPS, + + align:start position:0% +passive player FPS, + + + align:start position:0% +passive player FPS, +Pokemon style RPG, + + align:start position:0% +Pokemon style RPG, + + + align:start position:0% +Pokemon style RPG, +>> Pokemon seem like Pokemon FPS + + align:start position:0% +>> Pokemon seem like Pokemon FPS + + + align:start position:0% +>> Pokemon seem like Pokemon FPS +>> or as we were saying before like The + + align:start position:0% +>> or as we were saying before like The + + + align:start position:0% +>> or as we were saying before like The +Sims Online. + + align:start position:0% +Sims Online. + + + align:start position:0% +Sims Online. +>> The Sims Online was so good. + + align:start position:0% +>> The Sims Online was so good. + + + align:start position:0% +>> The Sims Online was so good. +>> Did you play as a Pokemon? + + align:start position:0% +>> Did you play as a Pokemon? + + + align:start position:0% +>> Did you play as a Pokemon? +>> Yeah, maybe play as a Pokemon, but it's + + align:start position:0% +>> Yeah, maybe play as a Pokemon, but it's + + + align:start position:0% +>> Yeah, maybe play as a Pokemon, but it's +a first person shooter. + + align:start position:0% +a first person shooter. + + + align:start position:0% +a first person shooter. +>> But more like, + + align:start position:0% +>> But more like, + + + align:start position:0% +>> But more like, +>> but you still have like an RPG first + + align:start position:0% +>> but you still have like an RPG first + + + align:start position:0% +>> but you still have like an RPG first +person shooter as Pokemon. Wait + + align:start position:0% +person shooter as Pokemon. Wait + + + align:start position:0% +person shooter as Pokemon. Wait +a + + align:start position:0% + + + + align:start position:0% + +>> zombie. + + align:start position:0% +>> zombie. + + + align:start position:0% +>> zombie. +>> Wait, you have to you have to fight you + + align:start position:0% +>> Wait, you have to you have to fight you + + + align:start position:0% +>> Wait, you have to you have to fight you +have battles with uh words like uh + + align:start position:0% +have battles with uh words like uh + + + align:start position:0% +have battles with uh words like uh +Monkey Island. + + align:start position:0% +Monkey Island. + + + align:start position:0% +Monkey Island. +>> I like that text based zombie love. + + align:start position:0% +>> I like that text based zombie love. + + + align:start position:0% +>> I like that text based zombie love. +>> Text based zombie love. + + align:start position:0% +>> Text based zombie love. + + + align:start position:0% +>> Text based zombie love. +>> And then his really really long tongue + + align:start position:0% +>> And then his really really long tongue + + + align:start position:0% +>> And then his really really long tongue +down your throat. + + align:start position:0% +down your throat. + + + align:start position:0% +down your throat. +>> Zombie make out. + + align:start position:0% +>> Zombie make out. + + + align:start position:0% +>> Zombie make out. +>> Son of a title. So, if it's massively + + align:start position:0% +>> Son of a title. So, if it's massively + + + align:start position:0% +>> Son of a title. So, if it's massively +multiplayer, what if you, you know, you + + align:start position:0% +multiplayer, what if you, you know, you + + + align:start position:0% +multiplayer, what if you, you know, you +randomly get paired with five other + + align:start position:0% +randomly get paired with five other + + + align:start position:0% +randomly get paired with five other +players who are playing this game and + + align:start position:0% +players who are playing this game and + + + align:start position:0% +players who are playing this game and +you all have some kind of task you have + + align:start position:0% +you all have some kind of task you have + + + align:start position:0% +you all have some kind of task you have +to complete and you're given these + + align:start position:0% +to complete and you're given these + + + align:start position:0% +to complete and you're given these +particular zombie Pokemon that you can + + align:start position:0% +particular zombie Pokemon that you can + + + align:start position:0% +particular zombie Pokemon that you can +use to complete this particular task. + + align:start position:0% +use to complete this particular task. + + + align:start position:0% +use to complete this particular task. +>> So, you working those with those five. + + align:start position:0% +>> So, you working those with those five. + + + align:start position:0% +>> So, you working those with those five. +>> Wait, we have zombie pokeballs. + + align:start position:0% +>> Wait, we have zombie pokeballs. + + + align:start position:0% +>> Wait, we have zombie pokeballs. +>> What? + + align:start position:0% +>> What? + + + align:start position:0% +>> What? +>> We have a title. + + align:start position:0% +>> We have a title. + + + align:start position:0% +>> We have a title. +>> So, uh, Necroilia + + align:start position:0% +>> So, uh, Necroilia + + + align:start position:0% +>> So, uh, Necroilia +with F E L. + + align:start position:0% +with F E L. + + + align:start position:0% +with F E L. +>> The first zombie sex game. + + align:start position:0% + + + + align:start position:0% + +Oh no. + + align:start position:0% +Oh no. + + + align:start position:0% +Oh no. +>> What if wait if it's going to be popular + + align:start position:0% +>> What if wait if it's going to be popular + + + align:start position:0% +>> What if wait if it's going to be popular +in Japan? You have to have tentful + + align:start position:0% +in Japan? You have to have tentful + + + align:start position:0% +in Japan? You have to have tentful +somewhere. + + align:start position:0% +somewhere. + + + align:start position:0% +somewhere. +>> What if you are a zombie and all the + + align:start position:0% +>> What if you are a zombie and all the + + + align:start position:0% +>> What if you are a zombie and all the +players are zombies and the NPCs are the + + align:start position:0% +players are zombies and the NPCs are the + + + align:start position:0% +players are zombies and the NPCs are the +humans and you like try to go on quests + + align:start position:0% +humans and you like try to go on quests + + + align:start position:0% +humans and you like try to go on quests +to make yourself more attractive and + + align:start position:0% +to make yourself more attractive and + + + align:start position:0% +to make yourself more attractive and +like learn human customs and you get + + align:start position:0% +like learn human customs and you get + + + align:start position:0% +like learn human customs and you get +points for like seducing humans. + + align:start position:0% +points for like seducing humans. + + + align:start position:0% +points for like seducing humans. +>> Yes. + + align:start position:0% +>> Yes. + + + align:start position:0% +>> Yes. +>> You have to make sure your your brain + + align:start position:0% +>> You have to make sure your your brain + + + align:start position:0% +>> You have to make sure your your brain +speed meter doesn't get too low though. + + align:start position:0% +speed meter doesn't get too low though. + + + align:start position:0% +speed meter doesn't get too low though. +>> So you have to eat them in seduce them + + align:start position:0% +>> So you have to eat them in seduce them + + + align:start position:0% +>> So you have to eat them in seduce them +in. And then if you like eat them with + + align:start position:0% +in. And then if you like eat them with + + + align:start position:0% +in. And then if you like eat them with +certain you + + align:start position:0% +certain you + + + align:start position:0% +certain you +>> eat the ones you don't want. + + align:start position:0% +>> eat the ones you don't want. + + + align:start position:0% +>> eat the ones you don't want. +>> You Yeah, + + align:start position:0% +>> You Yeah, + + + align:start position:0% +>> You Yeah, +>> that actually sounds like a fun vampire + + align:start position:0% +>> that actually sounds like a fun vampire + + + align:start position:0% +>> that actually sounds like a fun vampire +game. I'm going to put that out there. + + align:start position:0% +game. I'm going to put that out there. + + + align:start position:0% +game. I'm going to put that out there. +You're a vampire. You have to seduce a + + align:start position:0% +You're a vampire. You have to seduce a + + + align:start position:0% +You're a vampire. You have to seduce a +human female to bring back to drink. + + align:start position:0% +human female to bring back to drink. + + + align:start position:0% +human female to bring back to drink. +>> It's like prototype or or you have to + + align:start position:0% +>> It's like prototype or or you have to + + + align:start position:0% +>> It's like prototype or or you have to +seduce a human because you want to + + align:start position:0% +seduce a human because you want to + + + align:start position:0% +seduce a human because you want to +seduce a human, but at the same time you + + align:start position:0% +seduce a human, but at the same time you + + + align:start position:0% +seduce a human, but at the same time you +have to eat humans. So you have to hide + + align:start position:0% +have to eat humans. So you have to hide + + + align:start position:0% +have to eat humans. So you have to hide +the fact you're eating humans for the + + align:start position:0% +the fact you're eating humans for the + + + align:start position:0% +the fact you're eating humans for the +human decision. + + align:start position:0% +human decision. + + + align:start position:0% +human decision. +>> Oh, I see. So you have a human + + align:start position:0% +>> Oh, I see. So you have a human + + + align:start position:0% +>> Oh, I see. So you have a human +girlfriend and then like you eat other + + align:start position:0% +girlfriend and then like you eat other + + + align:start position:0% +girlfriend and then like you eat other +humans. + + align:start position:0% +humans. + + + align:start position:0% +humans. +>> Like while she's not looking like it's + + align:start position:0% +>> Like while she's not looking like it's + + + align:start position:0% +>> Like while she's not looking like it's +true. + + align:start position:0% +true. + + + align:start position:0% +true. +>> Have you been eating other girlfriends + + align:start position:0% +>> Have you been eating other girlfriends + + + align:start position:0% +>> Have you been eating other girlfriends +without me? Where's my stepdad? Uh, + + align:start position:0% +without me? Where's my stepdad? Uh, + + + align:start position:0% +without me? Where's my stepdad? Uh, +>> about that. + + align:start position:0% +>> about that. + + + align:start position:0% +>> about that. +>> Oh, that's who that guy was. I thought + + align:start position:0% +>> Oh, that's who that guy was. I thought + + + align:start position:0% +>> Oh, that's who that guy was. I thought +he was the delivery guy. + + align:start position:0% +he was the delivery guy. + + + align:start position:0% +he was the delivery guy. +>> Let's see. Zombies meets American + + align:start position:0% +>> Let's see. Zombies meets American + + + align:start position:0% +>> Let's see. Zombies meets American +Psycho. + + align:start position:0% + + + + align:start position:0% + +>> You've never seen American Psycho? Oh, + + align:start position:0% +>> You've never seen American Psycho? Oh, + + + align:start position:0% +>> You've never seen American Psycho? Oh, +>> Psycho. + + align:start position:0% +>> Psycho. + + + align:start position:0% +>> Psycho. +>> He goes around killing random people, + + align:start position:0% +>> He goes around killing random people, + + + align:start position:0% +>> He goes around killing random people, +but he has a girlfriend. I bet he's + + align:start position:0% +but he has a girlfriend. I bet he's + + + align:start position:0% +but he has a girlfriend. I bet he's +crazy. That's + + align:start position:0% +crazy. That's + + + align:start position:0% +crazy. That's +psycho, + + align:start position:0% +psycho, + + + align:start position:0% +psycho, +>> but better. + + align:start position:0% + + + + align:start position:0% + +So necroilia + + align:start position:0% +So necroilia + + + align:start position:0% +So necroilia +>> get infected with emotion. + + align:start position:0% +>> get infected with emotion. + + + align:start position:0% +>> get infected with emotion. +>> Necroilia infected with love. Brains + + align:start position:0% +>> Necroilia infected with love. Brains + + + align:start position:0% +>> Necroilia infected with love. Brains +>> love after. + + align:start position:0% +>> love after. + + + align:start position:0% +>> love after. +>> It's a perfect movie. It's a perfect + + align:start position:0% +>> It's a perfect movie. It's a perfect + + + align:start position:0% +>> It's a perfect movie. It's a perfect +game. + + align:start position:0% +game. + + + align:start position:0% +game. +>> All right, guys. I'm going to have you + + align:start position:0% +>> All right, guys. I'm going to have you + + + align:start position:0% +>> All right, guys. I'm going to have you +uh have you stop. We're going to read + + align:start position:0% +uh have you stop. We're going to read + + + align:start position:0% +uh have you stop. We're going to read +the other. + + align:start position:0% +the other. + + + align:start position:0% +the other. +>> Love After Life. + + align:start position:0% +>> Love After Life. + + + align:start position:0% +>> Love After Life. +>> I like it. I like it. + + align:start position:0% +>> I like it. I like it. + + + align:start position:0% +>> I like it. I like it. +>> That's really good. + + align:start position:0% + + + + align:start position:0% + +I think that was + + align:start position:0% +I think that was + + + align:start position:0% +I think that was +>> that was good. + + align:start position:0% +>> that was good. + + + align:start position:0% +>> that was good. +>> All right, guys. So, our publisher is + + align:start position:0% +>> All right, guys. So, our publisher is + + + align:start position:0% +>> All right, guys. So, our publisher is +going to give us so much. + + align:start position:0% + + + + align:start position:0% + +>> It may it may seem kind of kind of odd + + align:start position:0% +>> It may it may seem kind of kind of odd + + + align:start position:0% +>> It may it may seem kind of kind of odd +to have you guys do this brainstorming, + + align:start position:0% +to have you guys do this brainstorming, + + + align:start position:0% +to have you guys do this brainstorming, +then what I actually want to talk about + + align:start position:0% +then what I actually want to talk about + + + align:start position:0% +then what I actually want to talk about +is rather than the ideas that you came + + align:start position:0% +is rather than the ideas that you came + + + align:start position:0% +is rather than the ideas that you came +up with because I'm sure they're all + + align:start position:0% +up with because I'm sure they're all + + + align:start position:0% +up with because I'm sure they're all +really good. + + align:start position:0% +really good. + + + align:start position:0% +really good. +>> I know. So, sad. But what what really + + align:start position:0% +>> I know. So, sad. But what what really + + + align:start position:0% +>> I know. So, sad. But what what really +matters is the process, right? Because + + align:start position:0% +matters is the process, right? Because + + + align:start position:0% +matters is the process, right? Because +um the point of brainstorming is to + + align:start position:0% +um the point of brainstorming is to + + + align:start position:0% +um the point of brainstorming is to +withhold judgment. judging judging which + + align:start position:0% +withhold judgment. judging judging which + + + align:start position:0% +withhold judgment. judging judging which +of your ideas is best um shouldn't have + + align:start position:0% +of your ideas is best um shouldn't have + + + align:start position:0% +of your ideas is best um shouldn't have +even been happening at this stage. And + + align:start position:0% +even been happening at this stage. And + + + align:start position:0% +even been happening at this stage. And +so, you know, one one kind of question, + + align:start position:0% +so, you know, one one kind of question, + + + align:start position:0% +so, you know, one one kind of question, +you know, we'll come back to what went + + align:start position:0% +you know, we'll come back to what went + + + align:start position:0% +you know, we'll come back to what went +well, but um what what sort of uh + + align:start position:0% +well, but um what what sort of uh + + + align:start position:0% +well, but um what what sort of uh +stumbling blocks did you guys run into + + align:start position:0% +stumbling blocks did you guys run into + + + align:start position:0% +stumbling blocks did you guys run into +in this process as you were doing it? + + align:start position:0% +in this process as you were doing it? + + + align:start position:0% +in this process as you were doing it? +Did it did it all go perfectly or I + + align:start position:0% +Did it did it all go perfectly or I + + + align:start position:0% +Did it did it all go perfectly or I +highly doubt, but what sort of things + + align:start position:0% +highly doubt, but what sort of things + + + align:start position:0% +highly doubt, but what sort of things +>> I was going to say like we were trying + + align:start position:0% +>> I was going to say like we were trying + + + align:start position:0% +>> I was going to say like we were trying +to design this whole game. So, sometimes + + align:start position:0% +to design this whole game. So, sometimes + + + align:start position:0% +to design this whole game. So, sometimes +we say features and they would push + + align:start position:0% +we say features and they would push + + + align:start position:0% +we say features and they would push +games. + + align:start position:0% +games. + + + align:start position:0% +games. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +>> So it might have been + + align:start position:0% +>> So it might have been + + + align:start position:0% +>> So it might have been +like things you want. + + align:start position:0% +like things you want. + + + align:start position:0% +like things you want. +>> Yeah. Yeah. In some senses it may have + + align:start position:0% +>> Yeah. Yeah. In some senses it may have + + + align:start position:0% +>> Yeah. Yeah. In some senses it may have +been constrained in one area, right? + + align:start position:0% +been constrained in one area, right? + + + align:start position:0% +been constrained in one area, right? +Yeah. Sure. Zombies and a love story but + + align:start position:0% +Yeah. Sure. Zombies and a love story but + + + align:start position:0% +Yeah. Sure. Zombies and a love story but +but then it was like asking for a whole + + align:start position:0% +but then it was like asking for a whole + + + align:start position:0% +but then it was like asking for a whole +lot and so it could have been can we + + align:start position:0% +lot and so it could have been can we + + + align:start position:0% +lot and so it could have been can we +just brainstorm the title or can we just + + align:start position:0% +just brainstorm the title or can we just + + + align:start position:0% +just brainstorm the title or can we just +brainstorm this? Can we just brainstorm + + align:start position:0% +brainstorm this? Can we just brainstorm + + + align:start position:0% +brainstorm this? Can we just brainstorm +that? What about + + align:start position:0% +that? What about + + + align:start position:0% +that? What about +>> we very briefly got sidetracked on + + align:start position:0% +>> we very briefly got sidetracked on + + + align:start position:0% +>> we very briefly got sidetracked on +Pokemon? + + align:start position:0% + + + + align:start position:0% + +I think I think zombies for a second we + + align:start position:0% +I think I think zombies for a second we + + + align:start position:0% +I think I think zombies for a second we +got like it was like Pokemon only + + align:start position:0% +got like it was like Pokemon only + + + align:start position:0% +got like it was like Pokemon only +Pokemon first person shooter but that + + align:start position:0% +Pokemon first person shooter but that + + + align:start position:0% +Pokemon first person shooter but that +was like 25 seconds. + + align:start position:0% +was like 25 seconds. + + + align:start position:0% +was like 25 seconds. +>> Any other thoughts? I mean the whole + + align:start position:0% +>> Any other thoughts? I mean the whole + + + align:start position:0% +>> Any other thoughts? I mean the whole +recruit be like your help you had + + align:start position:0% +recruit be like your help you had + + + align:start position:0% +recruit be like your help you had +personally but if you had any challenges + + align:start position:0% +personally but if you had any challenges + + + align:start position:0% +personally but if you had any challenges +with like you know + + align:start position:0% +with like you know + + + align:start position:0% +with like you know +>> so I feel like if somebody says a really + + align:start position:0% +>> so I feel like if somebody says a really + + + align:start position:0% +>> so I feel like if somebody says a really +good idea and everyone's kind of stuck + + align:start position:0% +good idea and everyone's kind of stuck + + + align:start position:0% +good idea and everyone's kind of stuck +on that idea and you have to kind of get + + align:start position:0% +on that idea and you have to kind of get + + + align:start position:0% +on that idea and you have to kind of get +through that whole idea before any other + + align:start position:0% +through that whole idea before any other + + + align:start position:0% +through that whole idea before any other +ideas can come out. + + align:start position:0% +ideas can come out. + + + align:start position:0% +ideas can come out. +>> Yeah. Yeah. It's true. + + align:start position:0% +>> Yeah. Yeah. It's true. + + + align:start position:0% +>> Yeah. Yeah. It's true. +like what other kind of noise are there? + + align:start position:0% + + + + align:start position:0% + +>> Yeah. So like a few other ones. + + align:start position:0% + + + + align:start position:0% + +>> Sure. + + align:start position:0% +>> Sure. + + + align:start position:0% +>> Sure. +>> Kind of hard to like jump in my own + + align:start position:0% +>> Kind of hard to like jump in my own + + + align:start position:0% +>> Kind of hard to like jump in my own +ideas. + + align:start position:0% + + + + align:start position:0% + +>> Yeah, it's really hard to brainstorm. I + + align:start position:0% +>> Yeah, it's really hard to brainstorm. I + + + align:start position:0% +>> Yeah, it's really hard to brainstorm. I +mean you guys actually I mean both + + align:start position:0% +mean you guys actually I mean both + + + align:start position:0% +mean you guys actually I mean both +groups but I I stopped it with you guys + + align:start position:0% +groups but I I stopped it with you guys + + + align:start position:0% +groups but I I stopped it with you guys +and you guys had this interesting kind + + align:start position:0% +and you guys had this interesting kind + + + align:start position:0% +and you guys had this interesting kind +of momentum going and I was watching you + + align:start position:0% +of momentum going and I was watching you + + + align:start position:0% +of momentum going and I was watching you +trying to write it all down. It was it + + align:start position:0% +trying to write it all down. It was it + + + align:start position:0% +trying to write it all down. It was it +was way hard like because like ideas + + align:start position:0% +was way hard like because like ideas + + + align:start position:0% +was way hard like because like ideas +were coming in like as you were + + align:start position:0% +were coming in like as you were + + + align:start position:0% +were coming in like as you were +finishing the last idea. So it is you + + align:start position:0% +finishing the last idea. So it is you + + + align:start position:0% +finishing the last idea. So it is you +know if a group has really good momentum + + align:start position:0% +know if a group has really good momentum + + + align:start position:0% +know if a group has really good momentum +it's I I actually I really like the idea + + align:start position:0% +it's I I actually I really like the idea + + + align:start position:0% +it's I I actually I really like the idea +of having two people where each person's + + align:start position:0% +of having two people where each person's + + + align:start position:0% +of having two people where each person's +writing every other one. Of course the + + align:start position:0% +writing every other one. Of course the + + + align:start position:0% +writing every other one. Of course the +difficulty is then you kind of pull two + + align:start position:0% +difficulty is then you kind of pull two + + + align:start position:0% +difficulty is then you kind of pull two +people out of contributing right. So + + align:start position:0% +people out of contributing right. So + + + align:start position:0% +people out of contributing right. So +it's you know the organization of the + + align:start position:0% +it's you know the organization of the + + + align:start position:0% +it's you know the organization of the +actual group is is kind of important + + align:start position:0% +actual group is is kind of important + + + align:start position:0% +actual group is is kind of important +that works. + + align:start position:0% +that works. + + + align:start position:0% +that works. +>> Do you ever recommend using like a tape + + align:start position:0% +>> Do you ever recommend using like a tape + + + align:start position:0% +>> Do you ever recommend using like a tape +recorder like you're doing for this + + align:start position:0% +recorder like you're doing for this + + + align:start position:0% +recorder like you're doing for this +class? + + align:start position:0% +class? + + + align:start position:0% +class? +>> Yeah. Yeah. Absolutely. I mean that it's + + align:start position:0% +>> Yeah. Yeah. Absolutely. I mean that it's + + + align:start position:0% +>> Yeah. Yeah. Absolutely. I mean that it's +it certainly makes sense. One of the + + align:start position:0% +it certainly makes sense. One of the + + + align:start position:0% +it certainly makes sense. One of the +things that you know, one of the things + + align:start position:0% +things that you know, one of the things + + + align:start position:0% +things that you know, one of the things +that Osborne says, which I think is + + align:start position:0% +that Osborne says, which I think is + + + align:start position:0% +that Osborne says, which I think is +>> can't put a shape or cord down. Remember + + align:start position:0% +>> can't put a shape or cord down. Remember + + + align:start position:0% +>> can't put a shape or cord down. Remember +that. + + align:start position:0% +that. + + + align:start position:0% +that. +>> Yeah. Yeah. But he also says like it's + + align:start position:0% +>> Yeah. Yeah. But he also says like it's + + + align:start position:0% +>> Yeah. Yeah. But he also says like it's +the one of the most important things for + + align:start position:0% +the one of the most important things for + + + align:start position:0% +the one of the most important things for +the secretary scribe is to is to number + + align:start position:0% +the secretary scribe is to is to number + + + align:start position:0% +the secretary scribe is to is to number +things so that you know how many you + + align:start position:0% +things so that you know how many you + + + align:start position:0% +things so that you know how many you +have. I'm sort of like is that is that + + align:start position:0% +have. I'm sort of like is that is that + + + align:start position:0% +have. I'm sort of like is that is that +just to support your work? Like be like, + + align:start position:0% +just to support your work? Like be like, + + + align:start position:0% +just to support your work? Like be like, +look, you know, we came up with 110 + + align:start position:0% +look, you know, we came up with 110 + + + align:start position:0% +look, you know, we came up with 110 +ideas. That's amazing. You know, it's + + align:start position:0% +ideas. That's amazing. You know, it's + + + align:start position:0% +ideas. That's amazing. You know, it's +like how many doesn't seem to matter as + + align:start position:0% +like how many doesn't seem to matter as + + + align:start position:0% +like how many doesn't seem to matter as +much as the quality of the ideas. So, um + + align:start position:0% +much as the quality of the ideas. So, um + + + align:start position:0% +much as the quality of the ideas. So, um +I thought it was weird that you said + + align:start position:0% +I thought it was weird that you said + + + align:start position:0% +I thought it was weird that you said +that. But um yeah, I mean tape + + align:start position:0% +that. But um yeah, I mean tape + + + align:start position:0% +that. But um yeah, I mean tape +recording, video recording, any way of + + align:start position:0% +recording, video recording, any way of + + + align:start position:0% +recording, video recording, any way of +documenting the process I think is the + + align:start position:0% +documenting the process I think is the + + + align:start position:0% +documenting the process I think is the +most important problem. Um and and + + align:start position:0% +most important problem. Um and and + + + align:start position:0% +most important problem. Um and and +actually you know he does make a good + + align:start position:0% +actually you know he does make a good + + + align:start position:0% +actually you know he does make a good +point of saying you know one of the + + align:start position:0% +point of saying you know one of the + + + align:start position:0% +point of saying you know one of the +problems with brainstorming as it kind + + align:start position:0% +problems with brainstorming as it kind + + + align:start position:0% +problems with brainstorming as it kind +of evolved from when he first introduced + + align:start position:0% +of evolved from when he first introduced + + + align:start position:0% +of evolved from when he first introduced +it at this one place and when people + + align:start position:0% +it at this one place and when people + + + align:start position:0% +it at this one place and when people +started kind of running with it without + + align:start position:0% +started kind of running with it without + + + align:start position:0% +started kind of running with it without +thinking about the principles is they + + align:start position:0% +thinking about the principles is they + + + align:start position:0% +thinking about the principles is they +would brainstorm and then that was sort + + align:start position:0% +would brainstorm and then that was sort + + + align:start position:0% +would brainstorm and then that was sort +of it and it was like you really have to + + align:start position:0% +of it and it was like you really have to + + + align:start position:0% +of it and it was like you really have to +kind of look back at what you've come up + + align:start position:0% +kind of look back at what you've come up + + + align:start position:0% +kind of look back at what you've come up +with. Um it's really important to kind + + align:start position:0% +with. Um it's really important to kind + + + align:start position:0% +with. Um it's really important to kind +of reflect on what you've done as a + + align:start position:0% +of reflect on what you've done as a + + + align:start position:0% +of reflect on what you've done as a +second step. Um, you know, and so, uh, + + align:start position:0% +second step. Um, you know, and so, uh, + + + align:start position:0% +second step. Um, you know, and so, uh, +that's kind of important, too. How about + + align:start position:0% +that's kind of important, too. How about + + + align:start position:0% +that's kind of important, too. How about +the judgment thing? Was there I mean, + + align:start position:0% +the judgment thing? Was there I mean, + + + align:start position:0% +the judgment thing? Was there I mean, +people I I didn't notice a whole lot of + + align:start position:0% +people I I didn't notice a whole lot of + + + align:start position:0% +people I I didn't notice a whole lot of +like criticism, but like I don't think + + align:start position:0% +like criticism, but like I don't think + + + align:start position:0% +like criticism, but like I don't think +anybody was really good. I was like, oh, + + align:start position:0% +anybody was really good. I was like, oh, + + + align:start position:0% +anybody was really good. I was like, oh, +that's a terrible idea. But did you find + + align:start position:0% +that's a terrible idea. But did you find + + + align:start position:0% +that's a terrible idea. But did you find +it hard to not pass judgment on ideas as + + align:start position:0% +it hard to not pass judgment on ideas as + + + align:start position:0% +it hard to not pass judgment on ideas as +they were coming out, even your own? + + align:start position:0% +they were coming out, even your own? + + + align:start position:0% +they were coming out, even your own? +>> Yeah. I mean, I definitely let more than + + align:start position:0% +>> Yeah. I mean, I definitely let more than + + + align:start position:0% +>> Yeah. I mean, I definitely let more than +one like, I like that slip, you know, + + align:start position:0% +one like, I like that slip, you know, + + + align:start position:0% +one like, I like that slip, you know, +like, oh, that's + + align:start position:0% +like, oh, that's + + + align:start position:0% +like, oh, that's +>> generally that's okay. I mean like you + + align:start position:0% +>> generally that's okay. I mean like you + + + align:start position:0% +>> generally that's okay. I mean like you +know it's it's you know what you want to + + align:start position:0% +know it's it's you know what you want to + + + align:start position:0% +know it's it's you know what you want to +avoid is like the oh my god we've got to + + align:start position:0% +avoid is like the oh my god we've got to + + + align:start position:0% +avoid is like the oh my god we've got to +do this one you know like that's that + + align:start position:0% +do this one you know like that's that + + + align:start position:0% +do this one you know like that's that +will that will derail everything because + + align:start position:0% +will that will derail everything because + + + align:start position:0% +will that will derail everything because +then it's like you know just a loud the + + align:start position:0% +then it's like you know just a loud the + + + align:start position:0% +then it's like you know just a loud the +loud voice that proclaims that we're + + align:start position:0% +loud voice that proclaims that we're + + + align:start position:0% +loud voice that proclaims that we're +done because we got the idea will derail + + align:start position:0% +done because we got the idea will derail + + + align:start position:0% +done because we got the idea will derail +things but you know nothing encourages a + + align:start position:0% +things but you know nothing encourages a + + + align:start position:0% +things but you know nothing encourages a +person who's shy more than feeling like + + align:start position:0% +person who's shy more than feeling like + + + align:start position:0% +person who's shy more than feeling like +their idea actually was good or + + align:start position:0% +their idea actually was good or + + + align:start position:0% +their idea actually was good or +meritorious and so yeah you know that + + align:start position:0% +meritorious and so yeah you know that + + + align:start position:0% +meritorious and so yeah you know that +sort of stuff is fine u you know you + + align:start position:0% +sort of stuff is fine u you know you + + + align:start position:0% +sort of stuff is fine u you know you +want to avoid the stop the process + + align:start position:0% +want to avoid the stop the process + + + align:start position:0% +want to avoid the stop the process +>> I I think I did say at some point like + + align:start position:0% +>> I I think I did say at some point like + + + align:start position:0% +>> I I think I did say at some point like +We've got our title which is probably + + align:start position:0% +We've got our title which is probably + + + align:start position:0% +We've got our title which is probably +not. + + align:start position:0% +not. + + + align:start position:0% +not. +>> Yeah. I mean it's it's really it's just + + align:start position:0% +>> Yeah. I mean it's it's really it's just + + + align:start position:0% +>> Yeah. I mean it's it's really it's just +a hard thing to kind of train yourself + + align:start position:0% +a hard thing to kind of train yourself + + + align:start position:0% +a hard thing to kind of train yourself +from doing. + + align:start position:0% +from doing. + + + align:start position:0% +from doing. +>> Come on. Is it necroilia title? + + align:start position:0% +>> Come on. Is it necroilia title? + + + align:start position:0% +>> Come on. Is it necroilia title? +>> How + + align:start position:0% +>> How + + + align:start position:0% +>> How +many self-censorers still out there + + align:start position:0% +many self-censorers still out there + + + align:start position:0% +many self-censorers still out there +where a lot of people thought of ideas + + align:start position:0% +where a lot of people thought of ideas + + + align:start position:0% +where a lot of people thought of ideas +but then just didn't contribute? + + align:start position:0% +but then just didn't contribute? + + + align:start position:0% +but then just didn't contribute? +It's good if you didn't. It's great. I + + align:start position:0% +It's good if you didn't. It's great. I + + + align:start position:0% +It's good if you didn't. It's great. I +mean it's great if you if everybody felt + + align:start position:0% +mean it's great if you if everybody felt + + + align:start position:0% +mean it's great if you if everybody felt +like a cool that's that's really good. + + align:start position:0% +like a cool that's that's really good. + + + align:start position:0% +like a cool that's that's really good. +That's really good. So um so I would say + + align:start position:0% +That's really good. So um so I would say + + + align:start position:0% +That's really good. So um so I would say +that's one thing what that went well. + + align:start position:0% +that's one thing what that went well. + + + align:start position:0% +that's one thing what that went well. +What other things went well you guys? + + align:start position:0% +What other things went well you guys? + + + align:start position:0% +What other things went well you guys? +>> The tagline Yeah, specifically just + + align:start position:0% +>> The tagline Yeah, specifically just + + + align:start position:0% +>> The tagline Yeah, specifically just +coming up with tagline. + + align:start position:0% +coming up with tagline. + + + align:start position:0% +coming up with tagline. +>> Well, just in love + + align:start position:0% +>> Well, just in love + + + align:start position:0% +>> Well, just in love +life. Is it love after life? + + align:start position:0% +life. Is it love after life? + + + align:start position:0% +life. Is it love after life? +>> Love after life. + + align:start position:0% +>> Love after life. + + + align:start position:0% +>> Love after life. +>> That's cool. I mean, did you guys feel + + align:start position:0% +>> That's cool. I mean, did you guys feel + + + align:start position:0% +>> That's cool. I mean, did you guys feel +like you had momentum? It seemed to me + + align:start position:0% +like you had momentum? It seemed to me + + + align:start position:0% +like you had momentum? It seemed to me +watching that there was momentum + + align:start position:0% +watching that there was momentum + + + align:start position:0% +watching that there was momentum +building that it was + + align:start position:0% +building that it was + + + align:start position:0% +building that it was +>> I think you did a really good job of + + align:start position:0% +>> I think you did a really good job of + + + align:start position:0% +>> I think you did a really good job of +taking a lot of different ideas that we + + align:start position:0% +taking a lot of different ideas that we + + + align:start position:0% +taking a lot of different ideas that we +had and started synthesizing them into + + align:start position:0% +had and started synthesizing them into + + + align:start position:0% +had and started synthesizing them into +different things. Oh, that idea would + + align:start position:0% +different things. Oh, that idea would + + + align:start position:0% +different things. Oh, that idea would +work well if we did this. Oh, and then + + align:start position:0% +work well if we did this. Oh, and then + + + align:start position:0% +work well if we did this. Oh, and then +we could use like that name and that + + align:start position:0% +we could use like that name and that + + + align:start position:0% +we could use like that name and that +would fit there. + + align:start position:0% +would fit there. + + + align:start position:0% +would fit there. +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Who are the two leaders for the two + + align:start position:0% +>> Who are the two leaders for the two + + + align:start position:0% +>> Who are the two leaders for the two +groups? the clips. + + align:start position:0% +groups? the clips. + + + align:start position:0% +groups? the clips. +>> Did you did you guys feel like you had + + align:start position:0% +>> Did you did you guys feel like you had + + + align:start position:0% +>> Did you did you guys feel like you had +to do much facilitating + + align:start position:0% +to do much facilitating + + + align:start position:0% +to do much facilitating +>> really? So, the hard part is really just + + align:start position:0% +>> really? So, the hard part is really just + + + align:start position:0% +>> really? So, the hard part is really just +at the beginning where it's like how do + + align:start position:0% +at the beginning where it's like how do + + + align:start position:0% +at the beginning where it's like how do +we want to just approach this thing? And + + align:start position:0% +we want to just approach this thing? And + + + align:start position:0% +we want to just approach this thing? And +so, I guess we decided to start with the + + align:start position:0% +so, I guess we decided to start with the + + + align:start position:0% +so, I guess we decided to start with the +title or like it was either the titles + + align:start position:0% +title or like it was either the titles + + + align:start position:0% +title or like it was either the titles +or the main features and we were just + + align:start position:0% +or the main features and we were just + + + align:start position:0% +or the main features and we were just +like, all right, let's bunch of random + + align:start position:0% +like, all right, let's bunch of random + + + align:start position:0% +like, all right, let's bunch of random +titles, see + + align:start position:0% +titles, see + + + align:start position:0% +titles, see +>> forgot I was the lead. + + align:start position:0% +>> forgot I was the lead. + + + align:start position:0% +>> forgot I was the lead. +>> I didn't lead anything. + + align:start position:0% +>> I didn't lead anything. + + + align:start position:0% +>> I didn't lead anything. +you know, if if you don't have a whole + + align:start position:0% +you know, if if you don't have a whole + + + align:start position:0% +you know, if if you don't have a whole +lot of facilitating to do, it generally + + align:start position:0% +lot of facilitating to do, it generally + + + align:start position:0% +lot of facilitating to do, it generally +means that the group is running. Okay. + + align:start position:0% +means that the group is running. Okay. + + + align:start position:0% +means that the group is running. Okay. +Um, you know, I do think I do think you + + align:start position:0% +Um, you know, I do think I do think you + + + align:start position:0% +Um, you know, I do think I do think you +have a good point. A lot of the + + align:start position:0% +have a good point. A lot of the + + + align:start position:0% +have a good point. A lot of the +facilitators work comes at the beginning + + align:start position:0% +facilitators work comes at the beginning + + + align:start position:0% +facilitators work comes at the beginning +of the process or even before the + + align:start position:0% +of the process or even before the + + + align:start position:0% +of the process or even before the +process even began, making sure the + + align:start position:0% +process even began, making sure the + + + align:start position:0% +process even began, making sure the +constraints are clear and that you guys + + align:start position:0% +constraints are clear and that you guys + + + align:start position:0% +constraints are clear and that you guys +know what you're going to be working on. + + align:start position:0% +know what you're going to be working on. + + + align:start position:0% +know what you're going to be working on. +Um, okay. So, bringing this back, this + + align:start position:0% +Um, okay. So, bringing this back, this + + + align:start position:0% +Um, okay. So, bringing this back, this +is a game design class, right? I mean, I + + align:start position:0% +is a game design class, right? I mean, I + + + align:start position:0% +is a game design class, right? I mean, I +sort of touched on it early, but you + + align:start position:0% +sort of touched on it early, but you + + + align:start position:0% +sort of touched on it early, but you +know, how how do you guys see this um + + align:start position:0% +know, how how do you guys see this um + + + align:start position:0% +know, how how do you guys see this um +being a useful kind of mechanic or + + align:start position:0% +being a useful kind of mechanic or + + + align:start position:0% +being a useful kind of mechanic or +useful tool in you know what it's funny? + + align:start position:0% +useful tool in you know what it's funny? + + + align:start position:0% +useful tool in you know what it's funny? +I call it mechanic. Maybe you catch that + + align:start position:0% +I call it mechanic. Maybe you catch that + + + align:start position:0% +I call it mechanic. Maybe you catch that +paragraph in Alex where the guy was + + align:start position:0% +paragraph in Alex where the guy was + + + align:start position:0% +paragraph in Alex where the guy was +saying when my team feels like they're + + align:start position:0% +saying when my team feels like they're + + + align:start position:0% +saying when my team feels like they're +playing, it's a way more productive + + align:start position:0% +playing, it's a way more productive + + + align:start position:0% +playing, it's a way more productive +brainstorm than when not. And I thought + + align:start position:0% +brainstorm than when not. And I thought + + + align:start position:0% +brainstorm than when not. And I thought +that was really interesting, right? + + align:start position:0% +that was really interesting, right? + + + align:start position:0% +that was really interesting, right? +Because like there are elements of of + + align:start position:0% +Because like there are elements of of + + + align:start position:0% +Because like there are elements of of +giness to this. Um which I think is kind + + align:start position:0% +giness to this. Um which I think is kind + + + align:start position:0% +giness to this. Um which I think is kind +of interesting. Um, so you know, how do + + align:start position:0% +of interesting. Um, so you know, how do + + + align:start position:0% +of interesting. Um, so you know, how do +you guys think this could improve, you + + align:start position:0% +you guys think this could improve, you + + + align:start position:0% +you guys think this could improve, you +know, the general game design of the + + align:start position:0% +know, the general game design of the + + + align:start position:0% +know, the general game design of the +process? + + align:start position:0% + + + + align:start position:0% + +>> I feel like after you you have a game + + align:start position:0% +>> I feel like after you you have a game + + + align:start position:0% +>> I feel like after you you have a game +and you're testing it and there's like a + + align:start position:0% +and you're testing it and there's like a + + + align:start position:0% +and you're testing it and there's like a +major flaw that you know it's taking too + + align:start position:0% +major flaw that you know it's taking too + + + align:start position:0% +major flaw that you know it's taking too +long or or something like that and + + align:start position:0% +long or or something like that and + + + align:start position:0% +long or or something like that and +everyone sits down and brainstorm like + + align:start position:0% +everyone sits down and brainstorm like + + + align:start position:0% +everyone sits down and brainstorm like +okay this is exactly what our problem is + + align:start position:0% +okay this is exactly what our problem is + + + align:start position:0% +okay this is exactly what our problem is +fix it. + + align:start position:0% +fix it. + + + align:start position:0% +fix it. +>> Yeah. Yeah. Kind of overcoming + + align:start position:0% +>> Yeah. Yeah. Kind of overcoming + + + align:start position:0% +>> Yeah. Yeah. Kind of overcoming +roadblocks. Yeah. Sure. never to have + + align:start position:0% +roadblocks. Yeah. Sure. never to have + + + align:start position:0% +roadblocks. Yeah. Sure. never to have +come up with half the cool ideas that we + + align:start position:0% +come up with half the cool ideas that we + + + align:start position:0% +come up with half the cool ideas that we +came up with in the process and just me + + align:start position:0% +came up with in the process and just me + + + align:start position:0% +came up with in the process and just me +thinking alone never to come up with + + align:start position:0% +thinking alone never to come up with + + + align:start position:0% +thinking alone never to come up with +like Pokemon zombies. + + align:start position:0% + + + + align:start position:0% + +>> Well, this is good just in general make + + align:start position:0% +>> Well, this is good just in general make + + + align:start position:0% +>> Well, this is good just in general make +to think up a game because maybe it's + + align:start position:0% +to think up a game because maybe it's + + + align:start position:0% +to think up a game because maybe it's +like oh every single game has been + + align:start position:0% +like oh every single game has been + + + align:start position:0% +like oh every single game has been +decide people made games of all types. + + align:start position:0% +decide people made games of all types. + + + align:start position:0% +decide people made games of all types. +How am I going to make an unique game? + + align:start position:0% +How am I going to make an unique game? + + + align:start position:0% +How am I going to make an unique game? +It's brainstorm like hm those two things + + align:start position:0% +It's brainstorm like hm those two things + + + align:start position:0% +It's brainstorm like hm those two things +I've I've never seen that before. That + + align:start position:0% +I've I've never seen that before. That + + + align:start position:0% +I've I've never seen that before. That +could be interesting. Yeah, and that's a + + align:start position:0% +could be interesting. Yeah, and that's a + + + align:start position:0% +could be interesting. Yeah, and that's a +really good point actually. The + + align:start position:0% +really good point actually. The + + + align:start position:0% +really good point actually. The +synthesis + + align:start position:0% + + + + align:start position:0% + +thing is is actually I think something + + align:start position:0% +thing is is actually I think something + + + align:start position:0% +thing is is actually I think something +that's really important, right? Because + + align:start position:0% +that's really important, right? Because + + + align:start position:0% +that's really important, right? Because +um we do we tend to see a lot of recycle + + align:start position:0% +um we do we tend to see a lot of recycle + + + align:start position:0% +um we do we tend to see a lot of recycle +mechanics and what what becomes an + + align:start position:0% +mechanics and what what becomes an + + + align:start position:0% +mechanics and what what becomes an +interesting thing in a game often times + + align:start position:0% +interesting thing in a game often times + + + align:start position:0% +interesting thing in a game often times +is not that it's a completely new uh + + align:start position:0% +is not that it's a completely new uh + + + align:start position:0% +is not that it's a completely new uh +rule, right? It's the way that rule + + align:start position:0% +rule, right? It's the way that rule + + + align:start position:0% +rule, right? It's the way that rule +interacts with the other rules in the + + align:start position:0% +interacts with the other rules in the + + + align:start position:0% +interacts with the other rules in the +system. Um and and you know in some + + align:start position:0% +system. Um and and you know in some + + + align:start position:0% +system. Um and and you know in some +instances also how that rule is read and + + align:start position:0% +instances also how that rule is read and + + + align:start position:0% +instances also how that rule is read and +interpreted by the player or perhaps + + align:start position:0% +interpreted by the player or perhaps + + + align:start position:0% +interpreted by the player or perhaps +intended to be read and interpreted by + + align:start position:0% +intended to be read and interpreted by + + + align:start position:0% +intended to be read and interpreted by +the player. So um yeah, I think the + + align:start position:0% +the player. So um yeah, I think the + + + align:start position:0% +the player. So um yeah, I think the +synthesis is actually an interesting + + align:start position:0% +synthesis is actually an interesting + + + align:start position:0% +synthesis is actually an interesting +part of it where people can bring a lot + + align:start position:0% +part of it where people can bring a lot + + + align:start position:0% +part of it where people can bring a lot +of different ideas from a lot of + + align:start position:0% +of different ideas from a lot of + + + align:start position:0% +of different ideas from a lot of +different experiences with games um to + + align:start position:0% +different experiences with games um to + + + align:start position:0% +different experiences with games um to +kind of fuse these ideas together. Um + + align:start position:0% +kind of fuse these ideas together. Um + + + align:start position:0% +kind of fuse these ideas together. Um +just uh + + align:start position:0% +just uh + + + align:start position:0% +just uh +when it comes to coming up with ideas + + align:start position:0% +when it comes to coming up with ideas + + + align:start position:0% +when it comes to coming up with ideas +for games, nice thing about + + align:start position:0% +for games, nice thing about + + + align:start position:0% +for games, nice thing about +brainstorming is that it gets past the + + align:start position:0% +brainstorming is that it gets past the + + + align:start position:0% +brainstorming is that it gets past the +good idea that everyone happens to like. + + align:start position:0% +good idea that everyone happens to like. + + + align:start position:0% +good idea that everyone happens to like. +uh which is uh a problem that we + + align:start position:0% +uh which is uh a problem that we + + + align:start position:0% +uh which is uh a problem that we +sometimes have in the SP is people the + + align:start position:0% +sometimes have in the SP is people the + + + align:start position:0% +sometimes have in the SP is people the +people will find one idea they will + + align:start position:0% +people will find one idea they will + + + align:start position:0% +people will find one idea they will +never think past it that's because they + + align:start position:0% +never think past it that's because they + + + align:start position:0% +never think past it that's because they +were happy to find one that everybody + + align:start position:0% +were happy to find one that everybody + + + align:start position:0% +were happy to find one that everybody +>> yeah and so you guys are dividing into + + align:start position:0% +>> yeah and so you guys are dividing into + + + align:start position:0% +>> yeah and so you guys are dividing into +design teams and one of the things that + + align:start position:0% +design teams and one of the things that + + + align:start position:0% +design teams and one of the things that +I would encourage I don't know how it's + + align:start position:0% +I would encourage I don't know how it's + + + align:start position:0% +I would encourage I don't know how it's +set up schedule-wise but try to try to + + align:start position:0% +set up schedule-wise but try to try to + + + align:start position:0% +set up schedule-wise but try to try to +divide the brainstorming process from + + align:start position:0% +divide the brainstorming process from + + + align:start position:0% +divide the brainstorming process from +the judgment you know like I kind of + + align:start position:0% +the judgment you know like I kind of + + + align:start position:0% +the judgment you know like I kind of +said it's it's true like even even if + + align:start position:0% +said it's it's true like even even if + + + align:start position:0% +said it's it's true like even even if +you do the brainstorm it can help you + + align:start position:0% +you do the brainstorm it can help you + + + align:start position:0% +you do the brainstorm it can help you +get over. But a lot of times whatever + + align:start position:0% +get over. But a lot of times whatever + + + align:start position:0% +get over. But a lot of times whatever +had momentum during that brainstorm or + + align:start position:0% +had momentum during that brainstorm or + + + align:start position:0% +had momentum during that brainstorm or +whatever got the most yuck during that + + align:start position:0% +whatever got the most yuck during that + + + align:start position:0% +whatever got the most yuck during that +brainstorm, right, is going to be like + + align:start position:0% +brainstorm, right, is going to be like + + + align:start position:0% +brainstorm, right, is going to be like +the popular strong idea. And then when + + align:start position:0% +the popular strong idea. And then when + + + align:start position:0% +the popular strong idea. And then when +you come back to it with a little space, + + align:start position:0% +you come back to it with a little space, + + + align:start position:0% +you come back to it with a little space, +you might be like, "Oh, you know, like, + + align:start position:0% +you might be like, "Oh, you know, like, + + + align:start position:0% +you might be like, "Oh, you know, like, +yeah, that is a really good idea, but + + align:start position:0% +yeah, that is a really good idea, but + + + align:start position:0% +yeah, that is a really good idea, but +there was this other thing that got + + align:start position:0% +there was this other thing that got + + + align:start position:0% +there was this other thing that got +mentioned like a half an hour earlier + + align:start position:0% +mentioned like a half an hour earlier + + + align:start position:0% +mentioned like a half an hour earlier +that's really interesting. Maybe we + + align:start position:0% +that's really interesting. Maybe we + + + align:start position:0% +that's really interesting. Maybe we +could incorporate that somehow." And so + + align:start position:0% +could incorporate that somehow." And so + + + align:start position:0% +could incorporate that somehow." And so +kind of, you know, making the judgment + + align:start position:0% +kind of, you know, making the judgment + + + align:start position:0% +kind of, you know, making the judgment +happen in a in a separate phase can be + + align:start position:0% +happen in a in a separate phase can be + + + align:start position:0% +happen in a in a separate phase can be +really important. Um because it's true, + + align:start position:0% +really important. Um because it's true, + + + align:start position:0% +really important. Um because it's true, +creativity is like this, it's a little + + align:start position:0% +creativity is like this, it's a little + + + align:start position:0% +creativity is like this, it's a little +bit more organic. It's not necessarily a + + align:start position:0% +bit more organic. It's not necessarily a + + + align:start position:0% +bit more organic. It's not necessarily a +a strictly logical process, right? Um so + + align:start position:0% +a strictly logical process, right? Um so + + + align:start position:0% +a strictly logical process, right? Um so +applying logic later can be a good thing + + align:start position:0% +applying logic later can be a good thing + + + align:start position:0% +applying logic later can be a good thing +I think to the creative process. + + align:start position:0% +I think to the creative process. + + + align:start position:0% +I think to the creative process. +Cool. Any questions about brainstorming + + align:start position:0% +Cool. Any questions about brainstorming + + + align:start position:0% +Cool. Any questions about brainstorming +at all? You are incredibly enlightened + + align:start position:0% +at all? You are incredibly enlightened + + + align:start position:0% +at all? You are incredibly enlightened +by Alex Osbor + + align:start position:0% + + + + align:start position:0% + +on the forum actually people reading + + align:start position:0% +on the forum actually people reading + + + align:start position:0% +on the forum actually people reading +about using things like Google or Google + + align:start position:0% +about using things like Google or Google + + + align:start position:0% +about using things like Google or Google +Docs where things are automatically + + align:start position:0% +Docs where things are automatically + + + align:start position:0% +Docs where things are automatically +recorded because everyone's basically + + align:start position:0% +recorded because everyone's basically + + + align:start position:0% +recorded because everyone's basically +typing in their years. + + align:start position:0% +typing in their years. + + + align:start position:0% +typing in their years. +>> Yeah. I mean, I think it's interesting. + + align:start position:0% +>> Yeah. I mean, I think it's interesting. + + + align:start position:0% +>> Yeah. I mean, I think it's interesting. +I I don't have a whole lot of experience + + align:start position:0% +I I don't have a whole lot of experience + + + align:start position:0% +I I don't have a whole lot of experience +with Well, I should reframe. Um I I + + align:start position:0% +with Well, I should reframe. Um I I + + + align:start position:0% +with Well, I should reframe. Um I I +Well, I don't have a lot of experience + + align:start position:0% +Well, I don't have a lot of experience + + + align:start position:0% +Well, I don't have a lot of experience +with remote brainstorming, but I did + + align:start position:0% +with remote brainstorming, but I did + + + align:start position:0% +with remote brainstorming, but I did +have a um I did, you know, so one of the + + align:start position:0% +have a um I did, you know, so one of the + + + align:start position:0% +have a um I did, you know, so one of the +games I worked on this summer was this + + align:start position:0% +games I worked on this summer was this + + + align:start position:0% +games I worked on this summer was this +game called Yet One Word where um you + + align:start position:0% +game called Yet One Word where um you + + + align:start position:0% +game called Yet One Word where um you +were asked a lot of personal questions. + + align:start position:0% +were asked a lot of personal questions. + + + align:start position:0% +were asked a lot of personal questions. +And so, we had to think of personal + + align:start position:0% +And so, we had to think of personal + + + align:start position:0% +And so, we had to think of personal +questions. And at one, so we were like, + + align:start position:0% +questions. And at one, so we were like, + + + align:start position:0% +questions. And at one, so we were like, +well, if you have ideas, write it down + + align:start position:0% +well, if you have ideas, write it down + + + align:start position:0% +well, if you have ideas, write it down +in Google Doc. And at one point myself + + align:start position:0% +in Google Doc. And at one point myself + + + align:start position:0% +in Google Doc. And at one point myself +and two of the other designers were all + + align:start position:0% +and two of the other designers were all + + + align:start position:0% +and two of the other designers were all +in the Google doc at the same time. And + + align:start position:0% +in the Google doc at the same time. And + + + align:start position:0% +in the Google doc at the same time. And +you could actually see it that sort of + + align:start position:0% +you could actually see it that sort of + + + align:start position:0% +you could actually see it that sort of +brainstorming momentum happen. Someone + + align:start position:0% +brainstorming momentum happen. Someone + + + align:start position:0% +brainstorming momentum happen. Someone +would type something in and then like + + align:start position:0% +would type something in and then like + + + align:start position:0% +would type something in and then like +someone would type next like a that's so + + align:start position:0% +someone would type next like a that's so + + + align:start position:0% +someone would type next like a that's so +funny and then like write an idea that's + + align:start position:0% +funny and then like write an idea that's + + + align:start position:0% +funny and then like write an idea that's +related to that, right? And and you're + + align:start position:0% +related to that, right? And and you're + + + align:start position:0% +related to that, right? And and you're +kind of seeing it happen in this digital + + align:start position:0% +kind of seeing it happen in this digital + + + align:start position:0% +kind of seeing it happen in this digital +space. So I think it can we've gotten so + + align:start position:0% +space. So I think it can we've gotten so + + + align:start position:0% +space. So I think it can we've gotten so +accustomed to having these kind of um + + align:start position:0% +accustomed to having these kind of um + + + align:start position:0% +accustomed to having these kind of um +digital personalities, right? these + + align:start position:0% +digital personalities, right? these + + + align:start position:0% +digital personalities, right? these +digital personas in IMing and text + + align:start position:0% +digital personas in IMing and text + + + align:start position:0% +digital personas in IMing and text +messaging and all that other stuff that + + align:start position:0% +messaging and all that other stuff that + + + align:start position:0% +messaging and all that other stuff that +I I think we've gotten pretty adept at + + align:start position:0% +I I think we've gotten pretty adept at + + + align:start position:0% +I I think we've gotten pretty adept at +typing fast enough to get ideas out. But + + align:start position:0% +typing fast enough to get ideas out. But + + + align:start position:0% +typing fast enough to get ideas out. But +I think it could totally work. Um + + align:start position:0% +I think it could totally work. Um + + + align:start position:0% +I think it could totally work. Um +there's something to be said for like + + align:start position:0% +there's something to be said for like + + + align:start position:0% +there's something to be said for like +the momentum that gets generated in + + align:start position:0% +the momentum that gets generated in + + + align:start position:0% +the momentum that gets generated in +person. Um but yeah, I mean + + align:start position:0% +person. Um but yeah, I mean + + + align:start position:0% +person. Um but yeah, I mean +>> yeah I mean I was it's so funny. I was + + align:start position:0% +>> yeah I mean I was it's so funny. I was + + + align:start position:0% +>> yeah I mean I was it's so funny. I was +going to say like no that's a terrible + + align:start position:0% +going to say like no that's a terrible + + + align:start position:0% +going to say like no that's a terrible +idea you have to be around each other. I + + align:start position:0% +idea you have to be around each other. I + + + align:start position:0% +idea you have to be around each other. I +was like actually it worked. Um, I mean + + align:start position:0% +was like actually it worked. Um, I mean + + + align:start position:0% +was like actually it worked. Um, I mean +I think it all depends a little bit on + + align:start position:0% +I think it all depends a little bit on + + + align:start position:0% +I think it all depends a little bit on +personalities and people that are + + align:start position:0% +personalities and people that are + + + align:start position:0% +personalities and people that are +involved. + + align:start position:0% +involved. + + + align:start position:0% +involved. +Certainly for a prolonged brainstorm you + + align:start position:0% +Certainly for a prolonged brainstorm you + + + align:start position:0% +Certainly for a prolonged brainstorm you +one of the things Alex Osbourne says is + + align:start position:0% +one of the things Alex Osbourne says is + + + align:start position:0% +one of the things Alex Osbourne says is +like time box it if if you you know if + + align:start position:0% +like time box it if if you you know if + + + align:start position:0% +like time box it if if you you know if +you don't time box it's going to be a + + align:start position:0% +you don't time box it's going to be a + + + align:start position:0% +you don't time box it's going to be a +problem. I think for in person that's + + align:start position:0% +problem. I think for in person that's + + + align:start position:0% +problem. I think for in person that's +true. Um you know it's so easy to get + + align:start position:0% +true. Um you know it's so easy to get + + + align:start position:0% +true. Um you know it's so easy to get +onto a Google document now whenever you + + align:start position:0% +onto a Google document now whenever you + + + align:start position:0% +onto a Google document now whenever you +have an idea that actually having kind + + align:start position:0% +have an idea that actually having kind + + + align:start position:0% +have an idea that actually having kind +of a long phone brainstorm where anytime + + align:start position:0% +of a long phone brainstorm where anytime + + + align:start position:0% +of a long phone brainstorm where anytime +someone has an idea over a week or + + align:start position:0% +someone has an idea over a week or + + + align:start position:0% +someone has an idea over a week or +something like that write it down. um + + align:start position:0% +something like that write it down. um + + + align:start position:0% +something like that write it down. um +you know that's also useful too because + + align:start position:0% +you know that's also useful too because + + + align:start position:0% +you know that's also useful too because +then you know you separated the + + align:start position:0% +then you know you separated the + + + align:start position:0% +then you know you separated the +processes collecting and then but you + + align:start position:0% +processes collecting and then but you + + + align:start position:0% +processes collecting and then but you +still should do that sort of building on + + align:start position:0% +still should do that sort of building on + + + align:start position:0% +still should do that sort of building on +ideas. + + align:start position:0% +ideas. + + + align:start position:0% +ideas. +>> It's probably easier to do those + + align:start position:0% +>> It's probably easier to do those + + + align:start position:0% +>> It's probably easier to do those +synthesis when you're at least + + align:start position:0% +synthesis when you're at least + + + align:start position:0% +synthesis when you're at least +simultaneously on the line online or in + + align:start position:0% +simultaneously on the line online or in + + + align:start position:0% +simultaneously on the line online or in +the same room. + + align:start position:0% +the same room. + + + align:start position:0% +the same room. +>> Yep. Yeah. Yeah. And to see the ideas + + align:start position:0% +>> Yep. Yeah. Yeah. And to see the ideas + + + align:start position:0% +>> Yep. Yeah. Yeah. And to see the ideas +come out as they come out. + + align:start position:0% +come out as they come out. + + + align:start position:0% +come out as they come out. +>> Yeah. It's it's kind of it's a little + + align:start position:0% +>> Yeah. It's it's kind of it's a little + + + align:start position:0% +>> Yeah. It's it's kind of it's a little +uncommon to just read something and be + + align:start position:0% +uncommon to just read something and be + + + align:start position:0% +uncommon to just read something and be +like, "Oh, yeah. What about this when it + + align:start position:0% +like, "Oh, yeah. What about this when it + + + align:start position:0% +like, "Oh, yeah. What about this when it +first shows up?" When it first kind of + + align:start position:0% +first shows up?" When it first kind of + + + align:start position:0% +first shows up?" When it first kind of +comes into existence as you're trying to + + align:start position:0% +comes into existence as you're trying to + + + align:start position:0% +comes into existence as you're trying to +think of things that can spur ideas, you + + align:start position:0% +think of things that can spur ideas, you + + + align:start position:0% +think of things that can spur ideas, you +know, the other danger about doing it + + align:start position:0% +know, the other danger about doing it + + + align:start position:0% +know, the other danger about doing it +like, "Okay, this document is open for + + align:start position:0% +like, "Okay, this document is open for + + + align:start position:0% +like, "Okay, this document is open for +the next 24 hours. Everyone throw your + + align:start position:0% +the next 24 hours. Everyone throw your + + + align:start position:0% +the next 24 hours. Everyone throw your +ideas in." Is that then people start + + align:start position:0% +ideas in." Is that then people start + + + align:start position:0% +ideas in." Is that then people start +spending too long on any one idea + + align:start position:0% +spending too long on any one idea + + + align:start position:0% +spending too long on any one idea +thinking about what they're going to + + align:start position:0% +thinking about what they're going to + + + align:start position:0% +thinking about what they're going to +write down before they write it down and + + align:start position:0% +write down before they write it down and + + + align:start position:0% +write down before they write it down and +it's like, "No, that's not the point." + + align:start position:0% +it's like, "No, that's not the point." + + + align:start position:0% +it's like, "No, that's not the point." +>> Yeah. Yeah. Think of the paperclip + + align:start position:0% +>> Yeah. Yeah. Think of the paperclip + + + align:start position:0% +>> Yeah. Yeah. Think of the paperclip +experience and those of you that raised + + align:start position:0% +experience and those of you that raised + + + align:start position:0% +experience and those of you that raised +your hand for saying that you were + + align:start position:0% +your hand for saying that you were + + + align:start position:0% +your hand for saying that you were +self-censoring on your own. Like you + + align:start position:0% +self-censoring on your own. Like you + + + align:start position:0% +self-censoring on your own. Like you +didn't even have to I wasn't going to + + align:start position:0% +didn't even have to I wasn't going to + + + align:start position:0% +didn't even have to I wasn't going to +make you all hand in those paperclip + + align:start position:0% +make you all hand in those paperclip + + + align:start position:0% +make you all hand in those paperclip +ideas and you were self-censoring, + + align:start position:0% +ideas and you were self-censoring, + + + align:start position:0% +ideas and you were self-censoring, +right? So yeah, the same same sort of + + align:start position:0% +right? So yeah, the same same sort of + + + align:start position:0% +right? So yeah, the same same sort of +thing applies. Like you might you might + + align:start position:0% +thing applies. Like you might you might + + + align:start position:0% +thing applies. Like you might you might +censor yourself or spend a lot of time + + align:start position:0% +censor yourself or spend a lot of time + + + align:start position:0% +censor yourself or spend a lot of time +on ideas. So + + align:start position:0% +on ideas. So + + + align:start position:0% +on ideas. So +yeah, any other thoughts, questions? + + align:start position:0% +yeah, any other thoughts, questions? + + + align:start position:0% +yeah, any other thoughts, questions? +Cool. Well, I hope this was helpful. I + + align:start position:0% +Cool. Well, I hope this was helpful. I + + + align:start position:0% +Cool. Well, I hope this was helpful. I +hope it'll be helpful for your game + + align:start position:0% +hope it'll be helpful for your game + + + align:start position:0% +hope it'll be helpful for your game +design stuff. Um, email me if you do + + align:start position:0% +design stuff. Um, email me if you do + + + align:start position:0% +design stuff. Um, email me if you do +have any questions about this stuff. I + + align:start position:0% +have any questions about this stuff. I + + + align:start position:0% +have any questions about this stuff. I +mean, I can try to try to help out, but + + align:start position:0% +mean, I can try to try to help out, but + + + align:start position:0% +mean, I can try to try to help out, but +you know, + + align:start position:0% +you know, + + + align:start position:0% +you know, +other than that, good luck on your your + + align:start position:0% +other than that, good luck on your your + + + align:start position:0% +other than that, good luck on your your +game design for this class and for the + + align:start position:0% +game design for this class and for the + + + align:start position:0% +game design for this class and for the +rest of the cool. + + align:start position:0% + + + + align:start position:0% + +I do like that on the the keynote + + align:start position:0% +I do like that on the the keynote + + + align:start position:0% +I do like that on the the keynote +things. It says end of show. + + align:start position:0% + + + + align:start position:0% + +>> Uh let's see now. Uh we're going to play + + align:start position:0% +>> Uh let's see now. Uh we're going to play + + + align:start position:0% +>> Uh let's see now. Uh we're going to play +some card games, but before that, just a + + align:start position:0% +some card games, but before that, just a + + + align:start position:0% +some card games, but before that, just a +little bit of admin. Um on Monday you'll + + align:start position:0% +little bit of admin. Um on Monday you'll + + + align:start position:0% +little bit of admin. Um on Monday you'll +notice that uh we had two readings, one + + align:start position:0% +notice that uh we had two readings, one + + + align:start position:0% +notice that uh we had two readings, one +of which you've already done. So it + + align:start position:0% +of which you've already done. So it + + + align:start position:0% +of which you've already done. So it +doesn't matter. Um this is the other + + align:start position:0% +doesn't matter. Um this is the other + + + align:start position:0% +doesn't matter. Um this is the other +reading. It's a little bit dry. Tough it + + align:start position:0% +reading. It's a little bit dry. Tough it + + + align:start position:0% +reading. It's a little bit dry. Tough it +out. Caffeinate yourself reading it. + + align:start position:0% +out. Caffeinate yourself reading it. + + + align:start position:0% +out. Caffeinate yourself reading it. +Tough it out. It is worth it. It's + + align:start position:0% +Tough it out. It is worth it. It's + + + align:start position:0% +Tough it out. It is worth it. It's +translation. So + + align:start position:0% +translation. So + + + align:start position:0% +translation. So +uh let's see now. Um + + align:start position:0% + + + + align:start position:0% + +there there's at least one person um + + align:start position:0% +there there's at least one person um + + + align:start position:0% +there there's at least one person um +who hasn't form that we need to fill + + align:start position:0% +who hasn't form that we need to fill + + + align:start position:0% +who hasn't form that we need to fill +out. + + align:start position:0% +out. + + + align:start position:0% +out. +So just just come up here + + align:start position:0% +So just just come up here + + + align:start position:0% +So just just come up here +if + + align:start position:0% +if + + + align:start position:0% +if +at least four + + align:start position:0% +at least four + + + align:start position:0% +at least four +more time. + + align:start position:0% +more time. + + + align:start position:0% +more time. +>> Yeah, I'm not sure if we have enough to + + align:start position:0% +>> Yeah, I'm not sure if we have enough to + + + align:start position:0% +>> Yeah, I'm not sure if we have enough to +get through all of them, but most of + + align:start position:0% +get through all of them, but most of + + + align:start position:0% +get through all of them, but most of +them are pretty short. Uh uh a lot of + + align:start position:0% +them are pretty short. Uh uh a lot of + + + align:start position:0% +them are pretty short. Uh uh a lot of +them the delay is going to be set up + + align:start position:0% +them the delay is going to be set up + + + align:start position:0% +them the delay is going to be set up +which is why they couldn't first because + + align:start position:0% +which is why they couldn't first because + + + align:start position:0% +which is why they couldn't first because +uh uh that takes a lot of set up. That + + align:start position:0% +uh uh that takes a lot of set up. That + + + align:start position:0% +uh uh that takes a lot of set up. That +being said, um if you do get a chance to + + align:start position:0% +being said, um if you do get a chance to + + + align:start position:0% +being said, um if you do get a chance to +look at a rule and study the cards, um + + align:start position:0% +look at a rule and study the cards, um + + + align:start position:0% +look at a rule and study the cards, um +what like even though they've done a + + align:start position:0% +what like even though they've done a + + + align:start position:0% +what like even though they've done a +bunch of really really smart things on + + align:start position:0% +bunch of really really smart things on + + + align:start position:0% +bunch of really really smart things on +the cards just to make it easier for you + + align:start position:0% +the cards just to make it easier for you + + + align:start position:0% +the cards just to make it easier for you +to set up uh and you want to kind of + + align:start position:0% +to set up uh and you want to kind of + + + align:start position:0% +to set up uh and you want to kind of +paying attention to that, but the the + + align:start position:0% +paying attention to that, but the the + + + align:start position:0% +paying attention to that, but the the +the aim of the today is pretty much just + + align:start position:0% +the aim of the today is pretty much just + + + align:start position:0% +the aim of the today is pretty much just +variety. We have four fairly different + + align:start position:0% +variety. We have four fairly different + + + align:start position:0% +variety. We have four fairly different +kinds of games that use cards in a very + + align:start position:0% +kinds of games that use cards in a very + + + align:start position:0% +kinds of games that use cards in a very +different way. Uh and if you don't get a + + align:start position:0% +different way. Uh and if you don't get a + + + align:start position:0% +different way. Uh and if you don't get a +chance necessarily to play all of them, + + align:start position:0% +chance necessarily to play all of them, + + + align:start position:0% +chance necessarily to play all of them, +at least get a chance to look at other + + align:start position:0% +at least get a chance to look at other + + + align:start position:0% +at least get a chance to look at other +people playing with them and if you + + align:start position:0% +people playing with them and if you + + + align:start position:0% +people playing with them and if you +wanted to like check them out in the + + align:start position:0% +wanted to like check them out in the + + + align:start position:0% +wanted to like check them out in the +middle of the week or something just + + align:start position:0% +middle of the week or something just + + + align:start position:0% +middle of the week or something just +kick around the office but you know your + + align:start position:0% +kick around the office but you know your + + + align:start position:0% +kick around the office but you know your +time to come back here next week or + + align:start position:0% +time to come back here next week or + + + align:start position:0% +time to come back here next week or +something + + align:start position:0% +something + + + align:start position:0% +something +but uh that's basically it if we can + + align:start position:0% +but uh that's basically it if we can + + + align:start position:0% +but uh that's basically it if we can +just keep um uh if we can clear the + + align:start position:0% +just keep um uh if we can clear the + + + align:start position:0% +just keep um uh if we can clear the +tables we need them for the cards uh \ No newline at end of file diff --git a/Hgi3PSZI6Jw.txt b/Hgi3PSZI6Jw.txt new file mode 100644 index 0000000000000000000000000000000000000000..4410b980066736d9b6375a765cd881a162f5d7ad --- /dev/null +++ b/Hgi3PSZI6Jw.txt @@ -0,0 +1,7131 @@ +align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +oh + + align:start position:0% +oh + + + align:start position:0% +oh +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +hi we've spent the last couple of + + align:start position:0% +hi we've spent the last couple of + + + align:start position:0% +hi we've spent the last couple of +sessions looking at compensating + + align:start position:0% +sessions looking at compensating + + + align:start position:0% +sessions looking at compensating +feedback systems we started this + + align:start position:0% +feedback systems we started this + + + align:start position:0% +feedback systems we started this +discussion rather generally without + + align:start position:0% +discussion rather generally without + + + align:start position:0% +discussion rather generally without +really considering the realities that + + align:start position:0% +really considering the realities that + + + align:start position:0% +really considering the realities that +the system physical configuration often + + align:start position:0% +the system physical configuration often + + + align:start position:0% +the system physical configuration often +times forces upon us last time we did an + + align:start position:0% +times forces upon us last time we did an + + + align:start position:0% +times forces upon us last time we did an +example where we considered some of the + + align:start position:0% +example where we considered some of the + + + align:start position:0% +example where we considered some of the +constraints that actually apply in a + + align:start position:0% +constraints that actually apply in a + + + align:start position:0% +constraints that actually apply in a +physical + + align:start position:0% +physical + + + align:start position:0% +physical +system the topology we were using for + + align:start position:0% +system the topology we were using for + + + align:start position:0% +system the topology we were using for +that demonstration and in fact generally + + align:start position:0% +that demonstration and in fact generally + + + align:start position:0% +that demonstration and in fact generally +for our discussion to this point has + + align:start position:0% +for our discussion to this point has + + + align:start position:0% +for our discussion to this point has +been what's known as series or Cascade + + align:start position:0% +been what's known as series or Cascade + + + align:start position:0% +been what's known as series or Cascade +compensation and for that we have our + + align:start position:0% +compensation and for that we have our + + + align:start position:0% +compensation and for that we have our +general feedback form the type we + + align:start position:0% +general feedback form the type we + + + align:start position:0% +general feedback form the type we +feedback system form the kind we've been + + align:start position:0% +feedback system form the kind we've been + + + align:start position:0% +feedback system form the kind we've been +considering to this point where we have + + align:start position:0% +considering to this point where we have + + + align:start position:0% +considering to this point where we have +a forward path a a feedback path F very + + align:start position:0% +a forward path a a feedback path F very + + + align:start position:0% +a forward path a a feedback path F very +frequently the physical situation + + align:start position:0% +frequently the physical situation + + + align:start position:0% +frequently the physical situation +constrains the transfer functions of + + align:start position:0% +constrains the transfer functions of + + + align:start position:0% +constrains the transfer functions of +these two elements we frequently + + align:start position:0% +these two elements we frequently + + + align:start position:0% +these two elements we frequently +consider the element shown a fixed + + align:start position:0% +consider the element shown a fixed + + + align:start position:0% +consider the element shown a fixed +element f is very very frequently + + align:start position:0% +element f is very very frequently + + + align:start position:0% +element f is very very frequently +constrained by the ideal closed loop + + align:start position:0% +constrained by the ideal closed loop + + + align:start position:0% +constrained by the ideal closed loop +gain for our configuration to implement + + align:start position:0% +gain for our configuration to implement + + + align:start position:0% +gain for our configuration to implement +the series compensation or Cascade + + align:start position:0% +the series compensation or Cascade + + + align:start position:0% +the series compensation or Cascade +compensation that we've been considering + + align:start position:0% +compensation that we've been considering + + + align:start position:0% +compensation that we've been considering +up till now we add one more or possibly + + align:start position:0% +up till now we add one more or possibly + + + align:start position:0% +up till now we add one more or possibly +more than one element somewhere in the + + align:start position:0% +more than one element somewhere in the + + + align:start position:0% +more than one element somewhere in the +Loop we add it in series or in Cascade + + align:start position:0% +Loop we add it in series or in Cascade + + + align:start position:0% +Loop we add it in series or in Cascade +with the fixed elements we could add it + + align:start position:0% +with the fixed elements we could add it + + + align:start position:0% +with the fixed elements we could add it +here here here here the effect of adding + + align:start position:0% +here here here here the effect of adding + + + align:start position:0% +here here here here the effect of adding +it in any of those places on the loop + + align:start position:0% +it in any of those places on the loop + + + align:start position:0% +it in any of those places on the loop +transmission is identical of course and + + align:start position:0% +transmission is identical of course and + + + align:start position:0% +transmission is identical of course and +so it has the same effect on stability + + align:start position:0% +so it has the same effect on stability + + + align:start position:0% +so it has the same effect on stability +regardless of where we locate it however + + align:start position:0% +regardless of where we locate it however + + + align:start position:0% +regardless of where we locate it however +the actual closed loop gain of the + + align:start position:0% +the actual closed loop gain of the + + + align:start position:0% +the actual closed loop gain of the +system varies as a function of where we + + align:start position:0% +system varies as a function of where we + + + align:start position:0% +system varies as a function of where we +locate the series compensating element + + align:start position:0% +locate the series compensating element + + + align:start position:0% +locate the series compensating element +today I'd like to consider another way + + align:start position:0% +today I'd like to consider another way + + + align:start position:0% +today I'd like to consider another way +of compensating a feedback system + + align:start position:0% +of compensating a feedback system + + + align:start position:0% +of compensating a feedback system +uh in particular feedback or minor Loop + + align:start position:0% +uh in particular feedback or minor Loop + + + align:start position:0% +uh in particular feedback or minor Loop +compensation the topology for feedback + + align:start position:0% +compensation the topology for feedback + + + align:start position:0% +compensation the topology for feedback +compensation is shown in this view graph + + align:start position:0% +compensation is shown in this view graph + + + align:start position:0% +compensation is shown in this view graph +and this is a fundamentally different + + align:start position:0% +and this is a fundamentally different + + + align:start position:0% +and this is a fundamentally different +kind of topology from what we have with + + align:start position:0% +kind of topology from what we have with + + + align:start position:0% +kind of topology from what we have with +series + + align:start position:0% +series + + + align:start position:0% +series +compensation here we have a a two-loop + + align:start position:0% +compensation here we have a a two-loop + + + align:start position:0% +compensation here we have a a two-loop +system we have of course the input and + + align:start position:0% +system we have of course the input and + + + align:start position:0% +system we have of course the input and +the output and as always we have a a + + align:start position:0% +the output and as always we have a a + + + align:start position:0% +the output and as always we have a a +feedback element here and this feedback + + align:start position:0% +feedback element here and this feedback + + + align:start position:0% +feedback element here and this feedback +element labeled F1 is of of course the + + align:start position:0% +element labeled F1 is of of course the + + + align:start position:0% +element labeled F1 is of of course the +element that links the output back to + + align:start position:0% +element that links the output back to + + + align:start position:0% +element that links the output back to +the summing point in the system and so + + align:start position:0% +the summing point in the system and so + + + align:start position:0% +the summing point in the system and so +we choose F1 as a function of the + + align:start position:0% +we choose F1 as a function of the + + + align:start position:0% +we choose F1 as a function of the +desired or ideal Clos Loop gain of our + + align:start position:0% +desired or ideal Clos Loop gain of our + + + align:start position:0% +desired or ideal Clos Loop gain of our +feedback system in particular the ideal + + align:start position:0% +feedback system in particular the ideal + + + align:start position:0% +feedback system in particular the ideal +Clos Loop gain of this system is simply + + align:start position:0% +Clos Loop gain of this system is simply + + + align:start position:0% +Clos Loop gain of this system is simply +one over + + align:start position:0% +one over + + + align:start position:0% +one over +F1 in addition to the overall Loop which + + align:start position:0% +F1 in addition to the overall Loop which + + + align:start position:0% +F1 in addition to the overall Loop which +involves F1 this is oftentimes called an + + align:start position:0% +involves F1 this is oftentimes called an + + + align:start position:0% +involves F1 this is oftentimes called an +outer or a major Loop we have an inner + + align:start position:0% +outer or a major Loop we have an inner + + + align:start position:0% +outer or a major Loop we have an inner +or a minor + + align:start position:0% +or a minor + + + align:start position:0% +or a minor +Loop here and we show elements A2 and F2 + + align:start position:0% +Loop here and we show elements A2 and F2 + + + align:start position:0% +Loop here and we show elements A2 and F2 +associated with that minor + + align:start position:0% +associated with that minor + + + align:start position:0% +associated with that minor +Loop very frequently in this sort of + + align:start position:0% +Loop very frequently in this sort of + + + align:start position:0% +Loop very frequently in this sort of +feedback topology or system that's + + align:start position:0% +feedback topology or system that's + + + align:start position:0% +feedback topology or system that's +feedback compensated the elements A1 and + + align:start position:0% +feedback compensated the elements A1 and + + + align:start position:0% +feedback compensated the elements A1 and +A2 are fixed + + align:start position:0% +A2 are fixed + + + align:start position:0% +A2 are fixed +elements and the element F1 is of course + + align:start position:0% +elements and the element F1 is of course + + + align:start position:0% +elements and the element F1 is of course +chosen as a function of the ideal closed + + align:start position:0% +chosen as a function of the ideal closed + + + align:start position:0% +chosen as a function of the ideal closed +loop gain the way we then try to do + + align:start position:0% +loop gain the way we then try to do + + + align:start position:0% +loop gain the way we then try to do +compensation or try to affect + + align:start position:0% +compensation or try to affect + + + align:start position:0% +compensation or try to affect +compensation for this kind of a system + + align:start position:0% +compensation for this kind of a system + + + align:start position:0% +compensation for this kind of a system +very frequently boils down to the choice + + align:start position:0% +very frequently boils down to the choice + + + align:start position:0% +very frequently boils down to the choice +of the element used or the transfer + + align:start position:0% +of the element used or the transfer + + + align:start position:0% +of the element used or the transfer +function used for F2 so our hope is that + + align:start position:0% +function used for F2 so our hope is that + + + align:start position:0% +function used for F2 so our hope is that +we can select + + align:start position:0% +we can select + + + align:start position:0% +we can select +F2 in order to get acceptable + + align:start position:0% +F2 in order to get acceptable + + + align:start position:0% +F2 in order to get acceptable +performance from the overall + + align:start position:0% + + + + align:start position:0% + +system we can + + align:start position:0% +system we can + + + align:start position:0% +system we can +consider the transfer function V out + + align:start position:0% +consider the transfer function V out + + + align:start position:0% +consider the transfer function V out +over va va in the + + align:start position:0% +over va va in the + + + align:start position:0% +over va va in the +previous View graph was the voltage just + + align:start position:0% +previous View graph was the voltage just + + + align:start position:0% +previous View graph was the voltage just +out of the summing point in the major + + align:start position:0% +out of the summing point in the major + + + align:start position:0% +out of the summing point in the major +Loop and that transfer function is of + + align:start position:0% +Loop and that transfer function is of + + + align:start position:0% +Loop and that transfer function is of +course as + + align:start position:0% +course as + + + align:start position:0% +course as +always uh A1 that's a cascaded element + + align:start position:0% +always uh A1 that's a cascaded element + + + align:start position:0% +always uh A1 that's a cascaded element +and then we have a a reduction of the + + align:start position:0% +and then we have a a reduction of the + + + align:start position:0% +and then we have a a reduction of the +minor Loop the minor Loop has a forward + + align:start position:0% +minor Loop the minor Loop has a forward + + + align:start position:0% +minor Loop the minor Loop has a forward +path A2 and a feedback path F2 and so + + align:start position:0% +path A2 and a feedback path F2 and so + + + align:start position:0% +path A2 and a feedback path F2 and so +when we collapse the minor Loop we get a + + align:start position:0% +when we collapse the minor Loop we get a + + + align:start position:0% +when we collapse the minor Loop we get a +transfer function from the input to the + + align:start position:0% +transfer function from the input to the + + + align:start position:0% +transfer function from the input to the +output of the minor Loop that's simply + + align:start position:0% +output of the minor Loop that's simply + + + align:start position:0% +output of the minor Loop that's simply +A2 over 1 minus the transmission of the + + align:start position:0% +A2 over 1 minus the transmission of the + + + align:start position:0% +A2 over 1 minus the transmission of the +minor Loop uh in particular 1+ A2 + + align:start position:0% +minor Loop uh in particular 1+ A2 + + + align:start position:0% +minor Loop uh in particular 1+ A2 +F2 + + align:start position:0% +F2 + + + align:start position:0% +F2 +consequently the transfer function from + + align:start position:0% +consequently the transfer function from + + + align:start position:0% +consequently the transfer function from +here to here the effectively the forward + + align:start position:0% +here to here the effectively the forward + + + align:start position:0% +here to here the effectively the forward +path of the major Loop is simply A1 * A2 + + align:start position:0% +path of the major Loop is simply A1 * A2 + + + align:start position:0% +path of the major Loop is simply A1 * A2 +over 1 + A2 F2 + + align:start position:0% + + + + align:start position:0% + +using that value for the forward path of + + align:start position:0% +using that value for the forward path of + + + align:start position:0% +using that value for the forward path of +our major loop system we can write the + + align:start position:0% +our major loop system we can write the + + + align:start position:0% +our major loop system we can write the +overall output to input transfer + + align:start position:0% +overall output to input transfer + + + align:start position:0% +overall output to input transfer +function for the system and in + + align:start position:0% +function for the system and in + + + align:start position:0% +function for the system and in +particular it's our forward path the + + align:start position:0% +particular it's our forward path the + + + align:start position:0% +particular it's our forward path the +expression here divided by 1 minus the + + align:start position:0% +expression here divided by 1 minus the + + + align:start position:0% +expression here divided by 1 minus the +loop transmission of the major Loop uh + + align:start position:0% +loop transmission of the major Loop uh + + + align:start position:0% +loop transmission of the major Loop uh +the loop transmission of the major Loop + + align:start position:0% +the loop transmission of the major Loop + + + align:start position:0% +the loop transmission of the major Loop +is simply minus + + align:start position:0% +is simply minus + + + align:start position:0% +is simply minus +or the negative of loop transmission for + + align:start position:0% +or the negative of loop transmission for + + + align:start position:0% +or the negative of loop transmission for +the major Loop is simply this expression + + align:start position:0% +the major Loop is simply this expression + + + align:start position:0% +the major Loop is simply this expression +times fub1 consequently we get the input + + align:start position:0% +times fub1 consequently we get the input + + + align:start position:0% +times fub1 consequently we get the input +to Output transfer function for the + + align:start position:0% +to Output transfer function for the + + + align:start position:0% +to Output transfer function for the +overall system as + + align:start position:0% + + + + align:start position:0% + +shown we could certainly adjust + + align:start position:0% +shown we could certainly adjust + + + align:start position:0% +shown we could certainly adjust +parameters in this system by choosing F2 + + align:start position:0% +parameters in this system by choosing F2 + + + align:start position:0% +parameters in this system by choosing F2 +to get a desired closed loop transfer + + align:start position:0% +to get a desired closed loop transfer + + + align:start position:0% +to get a desired closed loop transfer +function hopefully to accomplish + + align:start position:0% +function hopefully to accomplish + + + align:start position:0% +function hopefully to accomplish +stability objectives and so forth and we + + align:start position:0% +stability objectives and so forth and we + + + align:start position:0% +stability objectives and so forth and we +could go through an exact mathematical + + align:start position:0% +could go through an exact mathematical + + + align:start position:0% +could go through an exact mathematical +development that would tell us the + + align:start position:0% +development that would tell us the + + + align:start position:0% +development that would tell us the +effect on overall performance of + + align:start position:0% +effect on overall performance of + + + align:start position:0% +effect on overall performance of +particular choices of the quantity F2 + + align:start position:0% +particular choices of the quantity F2 + + + align:start position:0% +particular choices of the quantity F2 +however that's not usually what we do + + align:start position:0% +however that's not usually what we do + + + align:start position:0% +however that's not usually what we do +the Hope in minor Loop compensation is + + align:start position:0% +the Hope in minor Loop compensation is + + + align:start position:0% +the Hope in minor Loop compensation is +that we're able to make the minor + + align:start position:0% +that we're able to make the minor + + + align:start position:0% +that we're able to make the minor +Loop effectively honest if you will + + align:start position:0% +Loop effectively honest if you will + + + align:start position:0% +Loop effectively honest if you will +controlled by feedback at the major Loop + + align:start position:0% +controlled by feedback at the major Loop + + + align:start position:0% +controlled by feedback at the major Loop +crossover frequency in other words what + + align:start position:0% +crossover frequency in other words what + + + align:start position:0% +crossover frequency in other words what +we do is hope that the loop transmission + + align:start position:0% +we do is hope that the loop transmission + + + align:start position:0% +we do is hope that the loop transmission +of the minor Loop the A2 F2 product at + + align:start position:0% +of the minor Loop the A2 F2 product at + + + align:start position:0% +of the minor Loop the A2 F2 product at +the frequency particularly of crossover + + align:start position:0% +the frequency particularly of crossover + + + align:start position:0% +the frequency particularly of crossover +of the major Loop we hope that that A2 + + align:start position:0% +of the major Loop we hope that that A2 + + + align:start position:0% +of the major Loop we hope that that A2 +F2 product is large if that's true then + + align:start position:0% +F2 product is large if that's true then + + + align:start position:0% +F2 product is large if that's true then +the transfer function from here to here + + align:start position:0% +the transfer function from here to here + + + align:start position:0% +the transfer function from here to here +is about equal to 1 over F2 if we didn't + + align:start position:0% +is about equal to 1 over F2 if we didn't + + + align:start position:0% +is about equal to 1 over F2 if we didn't +have everything else if this were just + + align:start position:0% +have everything else if this were just + + + align:start position:0% +have everything else if this were just +if this were the only part of our + + align:start position:0% +if this were the only part of our + + + align:start position:0% +if this were the only part of our +feedback system we'd of course argue + + align:start position:0% +feedback system we'd of course argue + + + align:start position:0% +feedback system we'd of course argue +that any frequency where the loop + + align:start position:0% +that any frequency where the loop + + + align:start position:0% +that any frequency where the loop +transmission magnitude was large + + align:start position:0% +transmission magnitude was large + + + align:start position:0% +transmission magnitude was large +compared to one the input to Output + + align:start position:0% +compared to one the input to Output + + + align:start position:0% +compared to one the input to Output +transfer function of that minor Loop + + align:start position:0% +transfer function of that minor Loop + + + align:start position:0% +transfer function of that minor Loop +would simply be equal to 1/ F2 and so + + align:start position:0% +would simply be equal to 1/ F2 and so + + + align:start position:0% +would simply be equal to 1/ F2 and so +our hope is as to say that at the + + align:start position:0% +our hope is as to say that at the + + + align:start position:0% +our hope is as to say that at the +crossover of the major Loop that + + align:start position:0% +crossover of the major Loop that + + + align:start position:0% +crossover of the major Loop that +condition is satisfied and the transfer + + align:start position:0% +condition is satisfied and the transfer + + + align:start position:0% +condition is satisfied and the transfer +function from here to here is about 1 + + align:start position:0% +function from here to here is about 1 + + + align:start position:0% +function from here to here is about 1 +over + + align:start position:0% +over + + + align:start position:0% +over +F2 if that's + + align:start position:0% +F2 if that's + + + align:start position:0% +F2 if that's +true we're able to + + align:start position:0% +true we're able to + + + align:start position:0% +true we're able to +design using an approximation that says + + align:start position:0% +design using an approximation that says + + + align:start position:0% +design using an approximation that says +the negative the loop transmission for + + align:start position:0% +the negative the loop transmission for + + + align:start position:0% +the negative the loop transmission for +the overall Loop is simply equal to A2 + + align:start position:0% +the overall Loop is simply equal to A2 + + + align:start position:0% +the overall Loop is simply equal to A2 +A1 F1 divided by F2 the elements A1 and + + align:start position:0% +A1 F1 divided by F2 the elements A1 and + + + align:start position:0% +A1 F1 divided by F2 the elements A1 and +F1 are elements associated with the + + align:start position:0% +F1 are elements associated with the + + + align:start position:0% +F1 are elements associated with the +major Loop one over F2 is the + + align:start position:0% +major Loop one over F2 is the + + + align:start position:0% +major Loop one over F2 is the +approximate input to Output transmission + + align:start position:0% +approximate input to Output transmission + + + align:start position:0% +approximate input to Output transmission +of the minor Loop and again our hope is + + align:start position:0% +of the minor Loop and again our hope is + + + align:start position:0% +of the minor Loop and again our hope is +as I indicated that the quantity A2 F2 + + align:start position:0% +as I indicated that the quantity A2 F2 + + + align:start position:0% +as I indicated that the quantity A2 F2 +evaluated at Omega C where Omega C is + + align:start position:0% +evaluated at Omega C where Omega C is + + + align:start position:0% +evaluated at Omega C where Omega C is +the crossover frequency of the major + + align:start position:0% +the crossover frequency of the major + + + align:start position:0% +the crossover frequency of the major +Loop is considerably larger than one + + align:start position:0% +Loop is considerably larger than one + + + align:start position:0% +Loop is considerably larger than one +that's the condition necessary to use + + align:start position:0% +that's the condition necessary to use + + + align:start position:0% +that's the condition necessary to use +this approximation for the transmission + + align:start position:0% +this approximation for the transmission + + + align:start position:0% +this approximation for the transmission +of the major loop as our design + + align:start position:0% + + + + align:start position:0% + +tool why do we feel we might be able to + + align:start position:0% +tool why do we feel we might be able to + + + align:start position:0% +tool why do we feel we might be able to +accomplish this sort of a thing well the + + align:start position:0% +accomplish this sort of a thing well the + + + align:start position:0% +accomplish this sort of a thing well the +thing that saves us generally or the + + align:start position:0% +thing that saves us generally or the + + + align:start position:0% +thing that saves us generally or the +thing that allows us to make the minor + + align:start position:0% +thing that allows us to make the minor + + + align:start position:0% +thing that allows us to make the minor +Loop have very high gain or very high + + align:start position:0% +Loop have very high gain or very high + + + align:start position:0% +Loop have very high gain or very high +Loop transmission magnitude at the + + align:start position:0% +Loop transmission magnitude at the + + + align:start position:0% +Loop transmission magnitude at the +crossover frequency of the major Loop + + align:start position:0% +crossover frequency of the major Loop + + + align:start position:0% +crossover frequency of the major Loop +really reflects the fact that there's + + align:start position:0% +really reflects the fact that there's + + + align:start position:0% +really reflects the fact that there's +relatively fewer elements in the minor + + align:start position:0% +relatively fewer elements in the minor + + + align:start position:0% +relatively fewer elements in the minor +Loop than there are in the overall + + align:start position:0% +Loop than there are in the overall + + + align:start position:0% +Loop than there are in the overall +Loop we recognize of course that as we + + align:start position:0% +Loop we recognize of course that as we + + + align:start position:0% +Loop we recognize of course that as we +increase the complexity of a feedback + + align:start position:0% +increase the complexity of a feedback + + + align:start position:0% +increase the complexity of a feedback +system increase the number of elements + + align:start position:0% +system increase the number of elements + + + align:start position:0% +system increase the number of elements +in a loop because of the low pass nature + + align:start position:0% +in a loop because of the low pass nature + + + align:start position:0% +in a loop because of the low pass nature +of those elements it becomes + + align:start position:0% +of those elements it becomes + + + align:start position:0% +of those elements it becomes +progressively more difficult to + + align:start position:0% +progressively more difficult to + + + align:start position:0% +progressively more difficult to +stabilize the loop we get more and more + + align:start position:0% +stabilize the loop we get more and more + + + align:start position:0% +stabilize the loop we get more and more +poles really associated with the energy + + align:start position:0% +poles really associated with the energy + + + align:start position:0% +poles really associated with the energy +storage becomes more difficult to + + align:start position:0% +storage becomes more difficult to + + + align:start position:0% +storage becomes more difficult to +stabilize the resultant Loop + + align:start position:0% +stabilize the resultant Loop + + + align:start position:0% +stabilize the resultant Loop +consequently Loops that contain fewer + + align:start position:0% +consequently Loops that contain fewer + + + align:start position:0% +consequently Loops that contain fewer +elements generally can be stabilized to + + align:start position:0% +elements generally can be stabilized to + + + align:start position:0% +elements generally can be stabilized to +have higher crossover frequencies than + + align:start position:0% +have higher crossover frequencies than + + + align:start position:0% +have higher crossover frequencies than +Loops which include more elements here + + align:start position:0% +Loops which include more elements here + + + align:start position:0% +Loops which include more elements here +as a say the minor Loop or the inner + + align:start position:0% +as a say the minor Loop or the inner + + + align:start position:0% +as a say the minor Loop or the inner +loop is a small fraction of the overall + + align:start position:0% +loop is a small fraction of the overall + + + align:start position:0% +loop is a small fraction of the overall +system and so there's at least some hope + + align:start position:0% +system and so there's at least some hope + + + align:start position:0% +system and so there's at least some hope +that we're able to make this Loop have a + + align:start position:0% +that we're able to make this Loop have a + + + align:start position:0% +that we're able to make this Loop have a +much higher crossover frequency than the + + align:start position:0% +much higher crossover frequency than the + + + align:start position:0% +much higher crossover frequency than the +overall Loop uh consequently we would + + align:start position:0% +overall Loop uh consequently we would + + + align:start position:0% +overall Loop uh consequently we would +find out that were true that the loop + + align:start position:0% +find out that were true that the loop + + + align:start position:0% +find out that were true that the loop +transmission magnitude of this Loop + + align:start position:0% +transmission magnitude of this Loop + + + align:start position:0% +transmission magnitude of this Loop +would be large at the crossover + + align:start position:0% +would be large at the crossover + + + align:start position:0% +would be large at the crossover +frequency of the major + + align:start position:0% + + + + align:start position:0% + +loop again assuming that uh that + + align:start position:0% +loop again assuming that uh that + + + align:start position:0% +loop again assuming that uh that +condition satisfied we go ahead and we + + align:start position:0% +condition satisfied we go ahead and we + + + align:start position:0% +condition satisfied we go ahead and we +can express the transfer function V out + + align:start position:0% +can express the transfer function V out + + + align:start position:0% +can express the transfer function V out +over VA again this is effectively the + + align:start position:0% +over VA again this is effectively the + + + align:start position:0% +over VA again this is effectively the +overall forward path transmission of our + + align:start position:0% +overall forward path transmission of our + + + align:start position:0% +overall forward path transmission of our +major Loop + + align:start position:0% +major Loop + + + align:start position:0% +major Loop +this is an exact expression for it at + + align:start position:0% +this is an exact expression for it at + + + align:start position:0% +this is an exact expression for it at +frequencies where the magnitude of the + + align:start position:0% +frequencies where the magnitude of the + + + align:start position:0% +frequencies where the magnitude of the +minor Loop transmission is much much + + align:start position:0% +minor Loop transmission is much much + + + align:start position:0% +minor Loop transmission is much much +larger than one and this is the case + + align:start position:0% +larger than one and this is the case + + + align:start position:0% +larger than one and this is the case +that we hope exists uh particularly at + + align:start position:0% +that we hope exists uh particularly at + + + align:start position:0% +that we hope exists uh particularly at +crossover of the major Loop so we can + + align:start position:0% +crossover of the major Loop so we can + + + align:start position:0% +crossover of the major Loop so we can +use this as our design tool the + + align:start position:0% +use this as our design tool the + + + align:start position:0% +use this as our design tool the +effective forward path of our overall + + align:start position:0% +effective forward path of our overall + + + align:start position:0% +effective forward path of our overall +system is A1 over F2 or is approximately + + align:start position:0% +system is A1 over F2 or is approximately + + + align:start position:0% +system is A1 over F2 or is approximately +A1 over F2 if we have the Other Extreme + + align:start position:0% +A1 over F2 if we have the Other Extreme + + + align:start position:0% +A1 over F2 if we have the Other Extreme +if the magnitude of the minor Loop + + align:start position:0% +if the magnitude of the minor Loop + + + align:start position:0% +if the magnitude of the minor Loop +transmission is small compared to one + + align:start position:0% +transmission is small compared to one + + + align:start position:0% +transmission is small compared to one +then the minor Loop is effectively + + align:start position:0% +then the minor Loop is effectively + + + align:start position:0% +then the minor Loop is effectively +working on an open loop basis the + + align:start position:0% +working on an open loop basis the + + + align:start position:0% +working on an open loop basis the +forward path for our major loop system + + align:start position:0% +forward path for our major loop system + + + align:start position:0% +forward path for our major loop system +simply becomes A1 A2 the transfer + + align:start position:0% +simply becomes A1 A2 the transfer + + + align:start position:0% +simply becomes A1 A2 the transfer +function F2 doesn't really influence the + + align:start position:0% +function F2 doesn't really influence the + + + align:start position:0% +function F2 doesn't really influence the +results very much in that + + align:start position:0% +results very much in that + + + align:start position:0% +results very much in that +case there's a nice graphical + + align:start position:0% +case there's a nice graphical + + + align:start position:0% +case there's a nice graphical +interpretation of this what we can do is + + align:start position:0% +interpretation of this what we can do is + + + align:start position:0% +interpretation of this what we can do is +plot the two limiting cases plot the two + + align:start position:0% +plot the two limiting cases plot the two + + + align:start position:0% +plot the two limiting cases plot the two +approximations in other words we plot A1 + + align:start position:0% +approximations in other words we plot A1 + + + align:start position:0% +approximations in other words we plot A1 +A2 and we also plot A1 over F2 we do + + align:start position:0% +A2 and we also plot A1 over F2 we do + + + align:start position:0% +A2 and we also plot A1 over F2 we do +that in bod plot form uh here's an + + align:start position:0% +that in bod plot form uh here's an + + + align:start position:0% +that in bod plot form uh here's an +assumed form for the plot A1 A2 I've + + align:start position:0% +assumed form for the plot A1 A2 I've + + + align:start position:0% +assumed form for the plot A1 A2 I've +assumed a two- pole kind of of + + align:start position:0% +assumed a two- pole kind of of + + + align:start position:0% +assumed a two- pole kind of of +transmission for + + align:start position:0% +transmission for + + + align:start position:0% +transmission for +that and then we also plot the quantity + + align:start position:0% +that and then we also plot the quantity + + + align:start position:0% +that and then we also plot the quantity +A1 over F2 that's the other limiting + + align:start position:0% +A1 over F2 that's the other limiting + + + align:start position:0% +A1 over F2 that's the other limiting +case and I've shown that here I've + + align:start position:0% +case and I've shown that here I've + + + align:start position:0% +case and I've shown that here I've +assumed in this plot that the quantity + + align:start position:0% +assumed in this plot that the quantity + + + align:start position:0% +assumed in this plot that the quantity +A1 over fub1 is single pole in nature uh + + align:start position:0% +A1 over fub1 is single pole in nature uh + + + align:start position:0% +A1 over fub1 is single pole in nature uh +and in fact as I've drawn it it reflects + + align:start position:0% +and in fact as I've drawn it it reflects + + + align:start position:0% +and in fact as I've drawn it it reflects +a pole at the or origin this would tell + + align:start position:0% +a pole at the or origin this would tell + + + align:start position:0% +a pole at the or origin this would tell +us that F1 is proportional to S if f1's + + align:start position:0% +us that F1 is proportional to S if f1's + + + align:start position:0% +us that F1 is proportional to S if f1's +proportional to s or at least one + + align:start position:0% +proportional to s or at least one + + + align:start position:0% +proportional to s or at least one +possibility is to have F1 proportional + + align:start position:0% +possibility is to have F1 proportional + + + align:start position:0% +possibility is to have F1 proportional +to S and A1 be frequency + + align:start position:0% +to S and A1 be frequency + + + align:start position:0% +to S and A1 be frequency +independent we'll see that that sort of + + align:start position:0% +independent we'll see that that sort of + + + align:start position:0% +independent we'll see that that sort of +transfer function is very frequently + + align:start position:0% +transfer function is very frequently + + + align:start position:0% +transfer function is very frequently +used for the quantity uh F2 I'm sorry + + align:start position:0% +used for the quantity uh F2 I'm sorry + + + align:start position:0% +used for the quantity uh F2 I'm sorry +this this should be + + align:start position:0% + + + + align:start position:0% + +F2 the U we find that that the transfer + + align:start position:0% +F2 the U we find that that the transfer + + + align:start position:0% +F2 the U we find that that the transfer +function of the feedback element in the + + align:start position:0% +function of the feedback element in the + + + align:start position:0% +function of the feedback element in the +minor Loop very frequently is a zero at + + align:start position:0% +minor Loop very frequently is a zero at + + + align:start position:0% +minor Loop very frequently is a zero at +the origin we'll see an example of that + + align:start position:0% +the origin we'll see an example of that + + + align:start position:0% +the origin we'll see an example of that +uh in the next lecture when we we do an + + align:start position:0% +uh in the next lecture when we we do an + + + align:start position:0% +uh in the next lecture when we we do an +example of this kind of compensation + + align:start position:0% +example of this kind of compensation + + + align:start position:0% +example of this kind of compensation +using an operational amplifier another + + align:start position:0% +using an operational amplifier another + + + align:start position:0% +using an operational amplifier another +possibility that you may very may be + + align:start position:0% +possibility that you may very may be + + + align:start position:0% +possibility that you may very may be +familiar with is the use of a tachometer + + align:start position:0% +familiar with is the use of a tachometer + + + align:start position:0% +familiar with is the use of a tachometer +in a Servo mechanism and what one does + + align:start position:0% +in a Servo mechanism and what one does + + + align:start position:0% +in a Servo mechanism and what one does +with a tachometer is measure the output + + align:start position:0% +with a tachometer is measure the output + + + align:start position:0% +with a tachometer is measure the output +velocity of the system and feed that + + align:start position:0% +velocity of the system and feed that + + + align:start position:0% +velocity of the system and feed that +back in a way that forms a minor Loop + + align:start position:0% +back in a way that forms a minor Loop + + + align:start position:0% +back in a way that forms a minor Loop +well the tachometer of course introduces + + align:start position:0% +well the tachometer of course introduces + + + align:start position:0% +well the tachometer of course introduces +a differentiation between output + + align:start position:0% +a differentiation between output + + + align:start position:0% +a differentiation between output +position and its signal so if we use a + + align:start position:0% +position and its signal so if we use a + + + align:start position:0% +position and its signal so if we use a +tachometer for monor Loop feedback in a + + align:start position:0% +tachometer for monor Loop feedback in a + + + align:start position:0% +tachometer for monor Loop feedback in a +in a Servo mechanism when we model that + + align:start position:0% +in a Servo mechanism when we model that + + + align:start position:0% +in a Servo mechanism when we model that +sort of a system we find that we formed + + align:start position:0% +sort of a system we find that we formed + + + align:start position:0% +sort of a system we find that we formed +a minor Loop Loop where the value of the + + align:start position:0% +a minor Loop Loop where the value of the + + + align:start position:0% +a minor Loop Loop where the value of the +feedback transfer function in the minor + + align:start position:0% +feedback transfer function in the minor + + + align:start position:0% +feedback transfer function in the minor +Loop is in fact proportional to S and in + + align:start position:0% +Loop is in fact proportional to S and in + + + align:start position:0% +Loop is in fact proportional to S and in +those sorts of cases why the quantity A1 + + align:start position:0% +those sorts of cases why the quantity A1 + + + align:start position:0% +those sorts of cases why the quantity A1 +over F2 can very easily have this sort + + align:start position:0% +over F2 can very easily have this sort + + + align:start position:0% +over F2 can very easily have this sort +of form well once we' plotted these two + + align:start position:0% +of form well once we' plotted these two + + + align:start position:0% +of form well once we' plotted these two +transfer functions uh in particular the + + align:start position:0% +transfer functions uh in particular the + + + align:start position:0% +transfer functions uh in particular the +two limiting approximations A1 over F2 + + align:start position:0% +two limiting approximations A1 over F2 + + + align:start position:0% +two limiting approximations A1 over F2 +uh which is the approximation that holds + + align:start position:0% +uh which is the approximation that holds + + + align:start position:0% +uh which is the approximation that holds +when the loop transmission of the minor + + align:start position:0% +when the loop transmission of the minor + + + align:start position:0% +when the loop transmission of the minor +Loop is large compared to one + + align:start position:0% +Loop is large compared to one + + + align:start position:0% +Loop is large compared to one +and the A1 A2 product which is the + + align:start position:0% +and the A1 A2 product which is the + + + align:start position:0% +and the A1 A2 product which is the +approximation that holds when the + + align:start position:0% +approximation that holds when the + + + align:start position:0% +approximation that holds when the +transmission of the minor Loop is small + + align:start position:0% +transmission of the minor Loop is small + + + align:start position:0% +transmission of the minor Loop is small +compared to one we can very easily + + align:start position:0% +compared to one we can very easily + + + align:start position:0% +compared to one we can very easily +determine which of these approximations + + align:start position:0% +determine which of these approximations + + + align:start position:0% +determine which of these approximations +holds at any given + + align:start position:0% +holds at any given + + + align:start position:0% +holds at any given +frequency consider a frequency for + + align:start position:0% +frequency consider a frequency for + + + align:start position:0% +frequency consider a frequency for +example between here and here where the + + align:start position:0% +example between here and here where the + + + align:start position:0% +example between here and here where the +A1 A2 product exceeds the A1 over F2 + + align:start position:0% +A1 A2 product exceeds the A1 over F2 + + + align:start position:0% +A1 A2 product exceeds the A1 over F2 +product + + align:start position:0% +product + + + align:start position:0% +product +in other words this condition if that's + + align:start position:0% +in other words this condition if that's + + + align:start position:0% +in other words this condition if that's +true and we simply divide both sides by + + align:start position:0% +true and we simply divide both sides by + + + align:start position:0% +true and we simply divide both sides by +A1 over F2 we find that over this entire + + align:start position:0% +A1 over F2 we find that over this entire + + + align:start position:0% +A1 over F2 we find that over this entire +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +range the A2 F2 product is large + + align:start position:0% +range the A2 F2 product is large + + + align:start position:0% +range the A2 F2 product is large +compared to one or at least greater than + + align:start position:0% +compared to one or at least greater than + + + align:start position:0% +compared to one or at least greater than +one if we consider the entire frequency + + align:start position:0% +one if we consider the entire frequency + + + align:start position:0% +one if we consider the entire frequency +range it's certainly large much greater + + align:start position:0% +range it's certainly large much greater + + + align:start position:0% +range it's certainly large much greater +than one possibly over this frequency + + align:start position:0% +than one possibly over this frequency + + + align:start position:0% +than one possibly over this frequency +range + + align:start position:0% +range + + + align:start position:0% +range +and if we look above we find out that at + + align:start position:0% +and if we look above we find out that at + + + align:start position:0% +and if we look above we find out that at +frequencies where that condition is + + align:start position:0% +frequencies where that condition is + + + align:start position:0% +frequencies where that condition is +satisfied in particular where A2 F2 is + + align:start position:0% +satisfied in particular where A2 F2 is + + + align:start position:0% +satisfied in particular where A2 F2 is +much much larger than one why an + + align:start position:0% +much much larger than one why an + + + align:start position:0% +much much larger than one why an +approximation to the forward path of our + + align:start position:0% +approximation to the forward path of our + + + align:start position:0% +approximation to the forward path of our +system is simply A1 over F2 so that says + + align:start position:0% +system is simply A1 over F2 so that says + + + align:start position:0% +system is simply A1 over F2 so that says +that in this frequency range we should + + align:start position:0% +that in this frequency range we should + + + align:start position:0% +that in this frequency range we should +use + + align:start position:0% +use + + + align:start position:0% +use +this line as an approximation to the + + align:start position:0% +this line as an approximation to the + + + align:start position:0% +this line as an approximation to the +forward path transfer function of our + + align:start position:0% +forward path transfer function of our + + + align:start position:0% +forward path transfer function of our +overall system + + align:start position:0% +overall system + + + align:start position:0% +overall system +if we reverse the inequality in other + + align:start position:0% +if we reverse the inequality in other + + + align:start position:0% +if we reverse the inequality in other +words if we're working at frequencies + + align:start position:0% +words if we're working at frequencies + + + align:start position:0% +words if we're working at frequencies +either below this frequency or above + + align:start position:0% +either below this frequency or above + + + align:start position:0% +either below this frequency or above +this one where A1 A2 is less than A1 + + align:start position:0% +this one where A1 A2 is less than A1 + + + align:start position:0% +this one where A1 A2 is less than A1 +over F2 the equal the inequality simply + + align:start position:0% +over F2 the equal the inequality simply + + + align:start position:0% +over F2 the equal the inequality simply +reverses and we find out that here and + + align:start position:0% +reverses and we find out that here and + + + align:start position:0% +reverses and we find out that here and +here in in those frequency ranges we + + align:start position:0% +here in in those frequency ranges we + + + align:start position:0% +here in in those frequency ranges we +should use A1 A2 as our approximation to + + align:start position:0% +should use A1 A2 as our approximation to + + + align:start position:0% +should use A1 A2 as our approximation to +the forward path transfer function of + + align:start position:0% +the forward path transfer function of + + + align:start position:0% +the forward path transfer function of +the + + align:start position:0% +the + + + align:start position:0% +the +system + + align:start position:0% +system + + + align:start position:0% +system +well a very simple way to do this is to + + align:start position:0% +well a very simple way to do this is to + + + align:start position:0% +well a very simple way to do this is to +Simply use the lower of these two curves + + align:start position:0% +Simply use the lower of these two curves + + + align:start position:0% +Simply use the lower of these two curves +at all frequencies that's a consequence + + align:start position:0% +at all frequencies that's a consequence + + + align:start position:0% +at all frequencies that's a consequence +of Simply checking the inequalities and + + align:start position:0% +of Simply checking the inequalities and + + + align:start position:0% +of Simply checking the inequalities and +so we conclude at least where the much + + align:start position:0% +so we conclude at least where the much + + + align:start position:0% +so we conclude at least where the much +greater than and much less than + + align:start position:0% +greater than and much less than + + + align:start position:0% +greater than and much less than +conditions were satisfied for example in + + align:start position:0% +conditions were satisfied for example in + + + align:start position:0% +conditions were satisfied for example in +this frequency + + align:start position:0% +this frequency + + + align:start position:0% +this frequency +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +range in this frequency + + align:start position:0% +range in this frequency + + + align:start position:0% +range in this frequency +range and in this frequency range we + + align:start position:0% +range and in this frequency range we + + + align:start position:0% +range and in this frequency range we +could simply select the lower of the two + + align:start position:0% +could simply select the lower of the two + + + align:start position:0% +could simply select the lower of the two +curves as being a very good + + align:start position:0% +curves as being a very good + + + align:start position:0% +curves as being a very good +approximation to the forward path + + align:start position:0% +approximation to the forward path + + + align:start position:0% +approximation to the forward path +transfer function of our overall system + + align:start position:0% +transfer function of our overall system + + + align:start position:0% +transfer function of our overall system +we have to worry a little bit about what + + align:start position:0% +we have to worry a little bit about what + + + align:start position:0% +we have to worry a little bit about what +happens where the magnitude uh the + + align:start position:0% +happens where the magnitude uh the + + + align:start position:0% +happens where the magnitude uh the +magnitudes are about equal in other + + align:start position:0% +magnitudes are about equal in other + + + align:start position:0% +magnitudes are about equal in other +words in this frequency range and in + + align:start position:0% +words in this frequency range and in + + + align:start position:0% +words in this frequency range and in +this frequency range uh and if we did + + align:start position:0% +this frequency range uh and if we did + + + align:start position:0% +this frequency range uh and if we did +that carefully we'd find out that for + + align:start position:0% +that carefully we'd find out that for + + + align:start position:0% +that carefully we'd find out that for +this this sort of situation where the + + align:start position:0% +this this sort of situation where the + + + align:start position:0% +this this sort of situation where the +slope of the two curves differ by one + + align:start position:0% +slope of the two curves differ by one + + + align:start position:0% +slope of the two curves differ by one +unit on logarithmic coordinates at the + + align:start position:0% +unit on logarithmic coordinates at the + + + align:start position:0% +unit on logarithmic coordinates at the +intersections uh we get basically uh the + + align:start position:0% +intersections uh we get basically uh the + + + align:start position:0% +intersections uh we get basically uh the +usual sort of single pole + + align:start position:0% +usual sort of single pole + + + align:start position:0% +usual sort of single pole +matching between the the two + + align:start position:0% +matching between the the two + + + align:start position:0% +matching between the the two +curves so the only place we have to take + + align:start position:0% +curves so the only place we have to take + + + align:start position:0% +curves so the only place we have to take +any particular care is in the immediate + + align:start position:0% +any particular care is in the immediate + + + align:start position:0% +any particular care is in the immediate +vicinity where the magnit uh where the + + align:start position:0% +vicinity where the magnit uh where the + + + align:start position:0% +vicinity where the magnit uh where the +magnitudes are are equal other than that + + align:start position:0% +magnitudes are are equal other than that + + + align:start position:0% +magnitudes are are equal other than that +we can just go ahead and approximate the + + align:start position:0% +we can just go ahead and approximate the + + + align:start position:0% +we can just go ahead and approximate the +forward path transfer function of our + + align:start position:0% +forward path transfer function of our + + + align:start position:0% +forward path transfer function of our +system as simply the lower of the two + + align:start position:0% +system as simply the lower of the two + + + align:start position:0% +system as simply the lower of the two +curves we'll very rapidly sort of relax + + align:start position:0% +curves we'll very rapidly sort of relax + + + align:start position:0% +curves we'll very rapidly sort of relax +this and and make an even cruder + + align:start position:0% +this and and make an even cruder + + + align:start position:0% +this and and make an even cruder +approximation and and really not worry + + align:start position:0% +approximation and and really not worry + + + align:start position:0% +approximation and and really not worry +too much about uh exactly what goes on + + align:start position:0% +too much about uh exactly what goes on + + + align:start position:0% +too much about uh exactly what goes on +in this vicinity and this vicinity uh + + align:start position:0% +in this vicinity and this vicinity uh + + + align:start position:0% +in this vicinity and this vicinity uh +simply go blindly ahead and take the + + align:start position:0% +simply go blindly ahead and take the + + + align:start position:0% +simply go blindly ahead and take the +lower of the two curves at all + + align:start position:0% +lower of the two curves at all + + + align:start position:0% +lower of the two curves at all +frequencies we find out that very + + align:start position:0% +frequencies we find out that very + + + align:start position:0% +frequencies we find out that very +frequently gives us completely + + align:start position:0% +frequently gives us completely + + + align:start position:0% +frequently gives us completely +satisfactory information for use as a + + align:start position:0% +satisfactory information for use as a + + + align:start position:0% +satisfactory information for use as a +design + + align:start position:0% + + + + align:start position:0% + +tool I mentioned that one common kind + + align:start position:0% +tool I mentioned that one common kind + + + align:start position:0% +tool I mentioned that one common kind +kind of a system that uses this sort of + + align:start position:0% +kind of a system that uses this sort of + + + align:start position:0% +kind of a system that uses this sort of +minor Loop compensation is that of a + + align:start position:0% +minor Loop compensation is that of a + + + align:start position:0% +minor Loop compensation is that of a +Servo mechanism where tachometric + + align:start position:0% +Servo mechanism where tachometric + + + align:start position:0% +Servo mechanism where tachometric +feedback is used the tachometer provides + + align:start position:0% +feedback is used the tachometer provides + + + align:start position:0% +feedback is used the tachometer provides +a zero at the origin at least if our if + + align:start position:0% +a zero at the origin at least if our if + + + align:start position:0% +a zero at the origin at least if our if +we consider the input to the tachometer + + align:start position:0% +we consider the input to the tachometer + + + align:start position:0% +we consider the input to the tachometer +to be mechanical position uh then it + + align:start position:0% +to be mechanical position uh then it + + + align:start position:0% +to be mechanical position uh then it +provides a differentiation of zero at + + align:start position:0% +provides a differentiation of zero at + + + align:start position:0% +provides a differentiation of zero at +the origin in its transfer function + + align:start position:0% +the origin in its transfer function + + + align:start position:0% +the origin in its transfer function +there's another case where monor Loop + + align:start position:0% +there's another case where monor Loop + + + align:start position:0% +there's another case where monor Loop +feedback is frequently used and that's + + align:start position:0% +feedback is frequently used and that's + + + align:start position:0% +feedback is frequently used and that's +in the design of most modern operational + + align:start position:0% +in the design of most modern operational + + + align:start position:0% +in the design of most modern operational +amplifiers + + align:start position:0% +amplifiers + + + align:start position:0% +amplifiers +this can be done either internal to the + + align:start position:0% +this can be done either internal to the + + + align:start position:0% +this can be done either internal to the +amplifier there are a number of + + align:start position:0% +amplifier there are a number of + + + align:start position:0% +amplifier there are a number of +amplifiers available where there's an + + align:start position:0% +amplifiers available where there's an + + + align:start position:0% +amplifiers available where there's an +internal minor Loop compensating element + + align:start position:0% +internal minor Loop compensating element + + + align:start position:0% +internal minor Loop compensating element +the 741 which is familiar to most of you + + align:start position:0% +the 741 which is familiar to most of you + + + align:start position:0% +the 741 which is familiar to most of you +is probably the best example or the most + + align:start position:0% +is probably the best example or the most + + + align:start position:0% +is probably the best example or the most +widely used example of that kind of an + + align:start position:0% +widely used example of that kind of an + + + align:start position:0% +widely used example of that kind of an +amplifier there are also several + + align:start position:0% +amplifier there are also several + + + align:start position:0% +amplifier there are also several +operational amplifiers available where + + align:start position:0% +operational amplifiers available where + + + align:start position:0% +operational amplifiers available where +provision is included for the user to + + align:start position:0% +provision is included for the user to + + + align:start position:0% +provision is included for the user to +complete compensating the amplifier + + align:start position:0% +complete compensating the amplifier + + + align:start position:0% +complete compensating the amplifier +really by forming a minor + + align:start position:0% +really by forming a minor + + + align:start position:0% +really by forming a minor +Loop and an amplifier like that uh we + + align:start position:0% +Loop and an amplifier like that uh we + + + align:start position:0% +Loop and an amplifier like that uh we +might be able to + + align:start position:0% +might be able to + + + align:start position:0% +might be able to +represent this + + align:start position:0% + + + + align:start position:0% + +way here we have the symbol for the + + align:start position:0% +way here we have the symbol for the + + + align:start position:0% +way here we have the symbol for the +operational amplifier anyway and a very + + align:start position:0% +operational amplifier anyway and a very + + + align:start position:0% +operational amplifier anyway and a very +common way of Designing these amplifiers + + align:start position:0% +common way of Designing these amplifiers + + + align:start position:0% +common way of Designing these amplifiers +is to basically use a two-stage design + + align:start position:0% +is to basically use a two-stage design + + + align:start position:0% +is to basically use a two-stage design +there's some sort of an input + + align:start position:0% +there's some sort of an input + + + align:start position:0% +there's some sort of an input +differential stage that takes the + + align:start position:0% +differential stage that takes the + + + align:start position:0% +differential stage that takes the +difference between the two voltages + + align:start position:0% +difference between the two voltages + + + align:start position:0% +difference between the two voltages +applied to the input terminals of the + + align:start position:0% +applied to the input terminals of the + + + align:start position:0% +applied to the input terminals of the +operational amplifier generally provides + + align:start position:0% +operational amplifier generally provides + + + align:start position:0% +operational amplifier generally provides +an output current proportional to that + + align:start position:0% +an output current proportional to that + + + align:start position:0% +an output current proportional to that +difference and then there's a second + + align:start position:0% +difference and then there's a second + + + align:start position:0% +difference and then there's a second +stage that provides very high voltage + + align:start position:0% +stage that provides very high voltage + + + align:start position:0% +stage that provides very high voltage +gain that that uses the output of the + + align:start position:0% +gain that that uses the output of the + + + align:start position:0% +gain that that uses the output of the +first stage and amplifies it by a large + + align:start position:0% +first stage and amplifies it by a large + + + align:start position:0% +first stage and amplifies it by a large +amount and by using appropriate design + + align:start position:0% +amount and by using appropriate design + + + align:start position:0% +amount and by using appropriate design +techniques in these two stage amplifiers + + align:start position:0% +techniques in these two stage amplifiers + + + align:start position:0% +techniques in these two stage amplifiers +or amplifiers that have really only two + + align:start position:0% +or amplifiers that have really only two + + + align:start position:0% +or amplifiers that have really only two +stages of voltage gain it's possible to + + align:start position:0% +stages of voltage gain it's possible to + + + align:start position:0% +stages of voltage gain it's possible to +get the kinds of of open loop gains at + + align:start position:0% +get the kinds of of open loop gains at + + + align:start position:0% +get the kinds of of open loop gains at +low frequencies the one normally + + align:start position:0% +low frequencies the one normally + + + align:start position:0% +low frequencies the one normally +Associates with operational amplifiers + + align:start position:0% +Associates with operational amplifiers + + + align:start position:0% +Associates with operational amplifiers +somewhere on the order of 100,000 to a + + align:start position:0% +somewhere on the order of 100,000 to a + + + align:start position:0% +somewhere on the order of 100,000 to a +million implying a voltage gain if it's + + align:start position:0% +million implying a voltage gain if it's + + + align:start position:0% +million implying a voltage gain if it's +equally distributed between the two + + align:start position:0% +equally distributed between the two + + + align:start position:0% +equally distributed between the two +stages of something like a thousand per + + align:start position:0% +stages of something like a thousand per + + + align:start position:0% +stages of something like a thousand per +stage well the way one then forms a + + align:start position:0% +stage well the way one then forms a + + + align:start position:0% +stage well the way one then forms a +minor Loop is to connect a compensating + + align:start position:0% +minor Loop is to connect a compensating + + + align:start position:0% +minor Loop is to connect a compensating +network from the output of the second + + align:start position:0% +network from the output of the second + + + align:start position:0% +network from the output of the second +stage back to the input of the second + + align:start position:0% +stage back to the input of the second + + + align:start position:0% +stage back to the input of the second +stage so a a minor Loops formed uh in + + align:start position:0% +stage so a a minor Loops formed uh in + + + align:start position:0% +stage so a a minor Loops formed uh in +general we could form that minor Loop + + align:start position:0% +general we could form that minor Loop + + + align:start position:0% +general we could form that minor Loop +using a two-port compensating Network + + align:start position:0% +using a two-port compensating Network + + + align:start position:0% +using a two-port compensating Network +and we'll see how that works but we form + + align:start position:0% +and we'll see how that works but we form + + + align:start position:0% +and we'll see how that works but we form +the monor loop around simply the second + + align:start position:0% +the monor loop around simply the second + + + align:start position:0% +the monor loop around simply the second +stage of the operational amplifier and + + align:start position:0% +stage of the operational amplifier and + + + align:start position:0% +stage of the operational amplifier and +consequently if we compare this topology + + align:start position:0% +consequently if we compare this topology + + + align:start position:0% +consequently if we compare this topology +with our earlier topology for a minor + + align:start position:0% +with our earlier topology for a minor + + + align:start position:0% +with our earlier topology for a minor +Loop compensated system uh this might + + align:start position:0% +Loop compensated system uh this might + + + align:start position:0% +Loop compensated system uh this might +represent the first stage of the + + align:start position:0% +represent the first stage of the + + + align:start position:0% +represent the first stage of the +operational amplifier this would + + align:start position:0% +operational amplifier this would + + + align:start position:0% +operational amplifier this would +represent the second stage with the + + align:start position:0% +represent the second stage with the + + + align:start position:0% +represent the second stage with the +two-port network providing the function + + align:start position:0% +two-port network providing the function + + + align:start position:0% +two-port network providing the function +F2 the feedback around the second stage + + align:start position:0% +F2 the feedback around the second stage + + + align:start position:0% +F2 the feedback around the second stage +which forms the minor Loop and then of + + align:start position:0% +which forms the minor Loop and then of + + + align:start position:0% +which forms the minor Loop and then of +course when we go to connect the + + align:start position:0% +course when we go to connect the + + + align:start position:0% +course when we go to connect the +operational amplifier in an overall + + align:start position:0% +operational amplifier in an overall + + + align:start position:0% +operational amplifier in an overall +feedback system in some overall feedback + + align:start position:0% +feedback system in some overall feedback + + + align:start position:0% +feedback system in some overall feedback +connection we add an external path F1 to + + align:start position:0% +connection we add an external path F1 to + + + align:start position:0% +connection we add an external path F1 to +complete the major + + align:start position:0% + + + + align:start position:0% + +Loop once again here's the the way we + + align:start position:0% +Loop once again here's the the way we + + + align:start position:0% +Loop once again here's the the way we +sort of implement the previous topology + + align:start position:0% +sort of implement the previous topology + + + align:start position:0% +sort of implement the previous topology +for an operational + + align:start position:0% + + + + align:start position:0% + +amplifier I'd like to look at a a very + + align:start position:0% +amplifier I'd like to look at a a very + + + align:start position:0% +amplifier I'd like to look at a a very +simplified representation of how such an + + align:start position:0% +simplified representation of how such an + + + align:start position:0% +simplified representation of how such an +operational amplifier works or so that + + align:start position:0% +operational amplifier works or so that + + + align:start position:0% +operational amplifier works or so that +we can can begin to look at the + + align:start position:0% +we can can begin to look at the + + + align:start position:0% +we can can begin to look at the +performance of this kind of an + + align:start position:0% +performance of this kind of an + + + align:start position:0% +performance of this kind of an +amplifier uh I've taken a few Liberties + + align:start position:0% +amplifier uh I've taken a few Liberties + + + align:start position:0% +amplifier uh I've taken a few Liberties +here with the construction of actual + + align:start position:0% +here with the construction of actual + + + align:start position:0% +here with the construction of actual +amplifiers there are some minor + + align:start position:0% +amplifiers there are some minor + + + align:start position:0% +amplifiers there are some minor +differences between the topology I'll + + align:start position:0% +differences between the topology I'll + + + align:start position:0% +differences between the topology I'll +present which is is very schematic in + + align:start position:0% +present which is is very schematic in + + + align:start position:0% +present which is is very schematic in +nature and the actual topology is used + + align:start position:0% +nature and the actual topology is used + + + align:start position:0% +nature and the actual topology is used +but they don't change any significant + + align:start position:0% +but they don't change any significant + + + align:start position:0% +but they don't change any significant +answers and so we'll we'll go ahead and + + align:start position:0% +answers and so we'll we'll go ahead and + + + align:start position:0% +answers and so we'll we'll go ahead and +look at this some what simplified + + align:start position:0% +look at this some what simplified + + + align:start position:0% +look at this some what simplified +representation bearing in mind that it + + align:start position:0% +representation bearing in mind that it + + + align:start position:0% +representation bearing in mind that it +does give us the correct answer for the + + align:start position:0% +does give us the correct answer for the + + + align:start position:0% +does give us the correct answer for the +transfer function of the operational + + align:start position:0% +transfer function of the operational + + + align:start position:0% +transfer function of the operational +amplifier we might have a differential + + align:start position:0% +amplifier we might have a differential + + + align:start position:0% +amplifier we might have a differential +input stage uh I've shown it constructed + + align:start position:0% +input stage uh I've shown it constructed + + + align:start position:0% +input stage uh I've shown it constructed +out of PNP transistors and that's the + + align:start position:0% +out of PNP transistors and that's the + + + align:start position:0% +out of PNP transistors and that's the +way it's done uh in amplifiers like the + + align:start position:0% +way it's done uh in amplifiers like the + + + align:start position:0% +way it's done uh in amplifiers like the +741 or at least the topological function + + align:start position:0% +741 or at least the topological function + + + align:start position:0% +741 or at least the topological function +of the input stage is the same as if it + + align:start position:0% +of the input stage is the same as if it + + + align:start position:0% +of the input stage is the same as if it +were constructed simply of PNP + + align:start position:0% +were constructed simply of PNP + + + align:start position:0% +were constructed simply of PNP +transistors and that differential pair + + align:start position:0% +transistors and that differential pair + + + align:start position:0% +transistors and that differential pair +of trans ancestors is generally biased + + align:start position:0% +of trans ancestors is generally biased + + + align:start position:0% +of trans ancestors is generally biased +with a current + + align:start position:0% +with a current + + + align:start position:0% +with a current +Source I've assumed for purposes of + + align:start position:0% +Source I've assumed for purposes of + + + align:start position:0% +Source I've assumed for purposes of +calculating the transfer function of the + + align:start position:0% +calculating the transfer function of the + + + align:start position:0% +calculating the transfer function of the +amplifier that we apply an input to only + + align:start position:0% +amplifier that we apply an input to only + + + align:start position:0% +amplifier that we apply an input to only +one side of the differential pair uh + + align:start position:0% +one side of the differential pair uh + + + align:start position:0% +one side of the differential pair uh +ground the other side so here's our our + + align:start position:0% +ground the other side so here's our our + + + align:start position:0% +ground the other side so here's our our +input signal + + align:start position:0% +input signal + + + align:start position:0% +input signal +VI and again in a little Distortion of + + align:start position:0% +VI and again in a little Distortion of + + + align:start position:0% +VI and again in a little Distortion of +reality but one that that does lead us + + align:start position:0% +reality but one that that does lead us + + + align:start position:0% +reality but one that that does lead us +to the correct result uh I assume that + + align:start position:0% +to the correct result uh I assume that + + + align:start position:0% +to the correct result uh I assume that +the first stage is loaded with a current + + align:start position:0% +the first stage is loaded with a current + + + align:start position:0% +the first stage is loaded with a current +Source in fact a fixed magnitude current + + align:start position:0% +Source in fact a fixed magnitude current + + + align:start position:0% +Source in fact a fixed magnitude current +source and what we generally do would be + + align:start position:0% +source and what we generally do would be + + + align:start position:0% +source and what we generally do would be +to connect or select this current source + + align:start position:0% +to connect or select this current source + + + align:start position:0% +to connect or select this current source +to have a value 1/ half of the current + + align:start position:0% +to have a value 1/ half of the current + + + align:start position:0% +to have a value 1/ half of the current +used to bias the entire first stage uh + + align:start position:0% +used to bias the entire first stage uh + + + align:start position:0% +used to bias the entire first stage uh +the rationale for that of course being + + align:start position:0% +the rationale for that of course being + + + align:start position:0% +the rationale for that of course being +that if these transistors are well + + align:start position:0% +that if these transistors are well + + + align:start position:0% +that if these transistors are well +matched when we had VI equal to zero the + + align:start position:0% +matched when we had VI equal to zero the + + + align:start position:0% +matched when we had VI equal to zero the +current applied to the emitter of the + + align:start position:0% +current applied to the emitter of the + + + align:start position:0% +current applied to the emitter of the +differential p pair would divide equally + + align:start position:0% +differential p pair would divide equally + + + align:start position:0% +differential p pair would divide equally +between the two members of the pair uh + + align:start position:0% +between the two members of the pair uh + + + align:start position:0% +between the two members of the pair uh +consequently the quiescent current with + + align:start position:0% +consequently the quiescent current with + + + align:start position:0% +consequently the quiescent current with +Zer volts applied to the differential + + align:start position:0% +Zer volts applied to the differential + + + align:start position:0% +Zer volts applied to the differential +pair The quiescent Collector current of + + align:start position:0% +pair The quiescent Collector current of + + + align:start position:0% +pair The quiescent Collector current of +this transistor would be 1/2 of the bias + + align:start position:0% +this transistor would be 1/2 of the bias + + + align:start position:0% +this transistor would be 1/2 of the bias +current + + align:start position:0% +current + + + align:start position:0% +current +uh the second stage of the amplifier is + + align:start position:0% +uh the second stage of the amplifier is + + + align:start position:0% +uh the second stage of the amplifier is +modeled uh uh even more diagrammatically + + align:start position:0% +modeled uh uh even more diagrammatically + + + align:start position:0% +modeled uh uh even more diagrammatically +than the first stage here we at least + + align:start position:0% +than the first stage here we at least + + + align:start position:0% +than the first stage here we at least +show a couple of transistors the second + + align:start position:0% +show a couple of transistors the second + + + align:start position:0% +show a couple of transistors the second +stage we simply assume has some put + + align:start position:0% +stage we simply assume has some put + + + align:start position:0% +stage we simply assume has some put +admittance while I've shown it as a + + align:start position:0% +admittance while I've shown it as a + + + align:start position:0% +admittance while I've shown it as a +resistor or a conductance why in general + + align:start position:0% +resistor or a conductance why in general + + + align:start position:0% +resistor or a conductance why in general +it's a a frequency dependent element + + align:start position:0% +it's a a frequency dependent element + + + align:start position:0% +it's a a frequency dependent element +let's call that + + align:start position:0% +let's call that + + + align:start position:0% +let's call that +Yi and the voltage across the input of + + align:start position:0% +Yi and the voltage across the input of + + + align:start position:0% +Yi and the voltage across the input of +the second stage the incremental voltage + + align:start position:0% +the second stage the incremental voltage + + + align:start position:0% +the second stage the incremental voltage +is a little bit of a problem with + + align:start position:0% +is a little bit of a problem with + + + align:start position:0% +is a little bit of a problem with +grounds but at least the incremental + + align:start position:0% +grounds but at least the incremental + + + align:start position:0% +grounds but at least the incremental +component of the voltage across the + + align:start position:0% +component of the voltage across the + + + align:start position:0% +component of the voltage across the +input to the second stage we'll call VA + + align:start position:0% +input to the second stage we'll call VA + + + align:start position:0% +input to the second stage we'll call VA +and the output voltage of the second + + align:start position:0% +and the output voltage of the second + + + align:start position:0% +and the output voltage of the second +stage which we assume is identically the + + align:start position:0% +stage which we assume is identically the + + + align:start position:0% +stage which we assume is identically the +output voltage of the operational + + align:start position:0% +output voltage of the operational + + + align:start position:0% +output voltage of the operational +amplifier usually there's some kind of + + align:start position:0% +amplifier usually there's some kind of + + + align:start position:0% +amplifier usually there's some kind of +of buffering in a mitter follower or + + align:start position:0% +of buffering in a mitter follower or + + + align:start position:0% +of buffering in a mitter follower or +something like that between the second + + align:start position:0% +something like that between the second + + + align:start position:0% +something like that between the second +stage itself and the output to make the + + align:start position:0% +stage itself and the output to make the + + + align:start position:0% +stage itself and the output to make the +second stage less sensitive to loads + + align:start position:0% +second stage less sensitive to loads + + + align:start position:0% +second stage less sensitive to loads +applied to the amplifier anyway we + + align:start position:0% +applied to the amplifier anyway we + + + align:start position:0% +applied to the amplifier anyway we +assume that we can model the second + + align:start position:0% +assume that we can model the second + + + align:start position:0% +assume that we can model the second +stage as a dependent voltage source and + + align:start position:0% +stage as a dependent voltage source and + + + align:start position:0% +stage as a dependent voltage source and +we'll call the gain from the input to + + align:start position:0% +we'll call the gain from the input to + + + align:start position:0% +we'll call the gain from the input to +the second stage to the output of the + + align:start position:0% +the second stage to the output of the + + + align:start position:0% +the second stage to the output of the +second stage simply a subi so we model + + align:start position:0% +second stage simply a subi so we model + + + align:start position:0% +second stage simply a subi so we model +the second stage as an input admittance + + align:start position:0% +the second stage as an input admittance + + + align:start position:0% +the second stage as an input admittance +y subi and a dependent generator whose + + align:start position:0% +y subi and a dependent generator whose + + + align:start position:0% +y subi and a dependent generator whose +magnitude is AI times the voltage + + align:start position:0% +magnitude is AI times the voltage + + + align:start position:0% +magnitude is AI times the voltage +applied to the input of the second stage + + align:start position:0% +applied to the input of the second stage + + + align:start position:0% +applied to the input of the second stage +we then form a minor Loop by connecting + + align:start position:0% +we then form a minor Loop by connecting + + + align:start position:0% +we then form a minor Loop by connecting +a compensating network from the output + + align:start position:0% +a compensating network from the output + + + align:start position:0% +a compensating network from the output +to a two-port + + align:start position:0% +to a two-port + + + align:start position:0% +to a two-port +network and the second side of the + + align:start position:0% +network and the second side of the + + + align:start position:0% +network and the second side of the +two-port network or the second Port of + + align:start position:0% +two-port network or the second Port of + + + align:start position:0% +two-port network or the second Port of +the two-port network is connected back + + align:start position:0% +the two-port network is connected back + + + align:start position:0% +the two-port network is connected back +to the input of the second stage we'll + + align:start position:0% +to the input of the second stage we'll + + + align:start position:0% +to the input of the second stage we'll +find it convenient to represent present + + align:start position:0% +find it convenient to represent present + + + align:start position:0% +find it convenient to represent present +the two Port uh in terms of its + + align:start position:0% +the two Port uh in terms of its + + + align:start position:0% +the two Port uh in terms of its +shortcircuit transfer + + align:start position:0% +shortcircuit transfer + + + align:start position:0% +shortcircuit transfer +admittance at least as I've shown things + + align:start position:0% +admittance at least as I've shown things + + + align:start position:0% +admittance at least as I've shown things +where we apply the voltage from a + + align:start position:0% +where we apply the voltage from a + + + align:start position:0% +where we apply the voltage from a +voltage source to one side of the two + + align:start position:0% +voltage source to one side of the two + + + align:start position:0% +voltage source to one side of the two +Port we don't have to worry about + + align:start position:0% +Port we don't have to worry about + + + align:start position:0% +Port we don't have to worry about +parameters of the two port at this side + + align:start position:0% +parameters of the two port at this side + + + align:start position:0% +parameters of the two port at this side +of the + + align:start position:0% +of the + + + align:start position:0% +of the +network uh they can't really affect + + align:start position:0% +network uh they can't really affect + + + align:start position:0% +network uh they can't really affect +operation if this model is valid since + + align:start position:0% +operation if this model is valid since + + + align:start position:0% +operation if this model is valid since +the input parameters on the two Port + + align:start position:0% +the input parameters on the two Port + + + align:start position:0% +the input parameters on the two Port +can't affect the voltage of of this + + align:start position:0% +can't affect the voltage of of this + + + align:start position:0% +can't affect the voltage of of this +Source uh however we do have to worry + + align:start position:0% +Source uh however we do have to worry + + + align:start position:0% +Source uh however we do have to worry +about modeling the two port at its + + align:start position:0% +about modeling the two port at its + + + align:start position:0% +about modeling the two port at its +output side and we'll do that in an + + align:start position:0% +output side and we'll do that in an + + + align:start position:0% +output side and we'll do that in an +admittance form where we show the two + + align:start position:0% +admittance form where we show the two + + + align:start position:0% +admittance form where we show the two +Port as a y sub a uh uh an output + + align:start position:0% +Port as a y sub a uh uh an output + + + align:start position:0% +Port as a y sub a uh uh an output +admittance at this port and a + + align:start position:0% +admittance at this port and a + + + align:start position:0% +admittance at this port and a +shortcircuit transfer admittance a + + align:start position:0% +shortcircuit transfer admittance a + + + align:start position:0% +shortcircuit transfer admittance a +dependent current Source uh which is + + align:start position:0% +dependent current Source uh which is + + + align:start position:0% +dependent current Source uh which is +dependent on the voltage applied to this + + align:start position:0% +dependent on the voltage applied to this + + + align:start position:0% +dependent on the voltage applied to this +side of the two Port so we can model our + + align:start position:0% +side of the two Port so we can model our + + + align:start position:0% +side of the two Port so we can model our +two port at this side as say is this + + align:start position:0% +two port at this side as say is this + + + align:start position:0% +two port at this side as say is this +admittance this dependent current source + + align:start position:0% +admittance this dependent current source + + + align:start position:0% +admittance this dependent current source +of course to evaluate the quantity y + + align:start position:0% +of course to evaluate the quantity y + + + align:start position:0% +of course to evaluate the quantity y +subc we'd perform an experiment where + + align:start position:0% +subc we'd perform an experiment where + + + align:start position:0% +subc we'd perform an experiment where +we'd incrementally short this port of + + align:start position:0% +we'd incrementally short this port of + + + align:start position:0% +we'd incrementally short this port of +the two port and would then measure the + + align:start position:0% +the two port and would then measure the + + + align:start position:0% +the two port and would then measure the +relationship between that shortcircuit + + align:start position:0% +relationship between that shortcircuit + + + align:start position:0% +relationship between that shortcircuit +current that we observed and the voltage + + align:start position:0% +current that we observed and the voltage + + + align:start position:0% +current that we observed and the voltage +V subn we' find that I Y subc was simply + + align:start position:0% +V subn we' find that I Y subc was simply + + + align:start position:0% +V subn we' find that I Y subc was simply +the ratio of the shortcircuit current to + + align:start position:0% +the ratio of the shortcircuit current to + + + align:start position:0% +the ratio of the shortcircuit current to +the voltage applied to this part of the + + align:start position:0% +the voltage applied to this part of the + + + align:start position:0% +the voltage applied to this part of the +network let me point out that my + + align:start position:0% +network let me point out that my + + + align:start position:0% +network let me point out that my +convention here is a little bit at + + align:start position:0% +convention here is a little bit at + + + align:start position:0% +convention here is a little bit at +variance with standard two-port + + align:start position:0% +variance with standard two-port + + + align:start position:0% +variance with standard two-port +convention and I've chosen to do that + + align:start position:0% +convention and I've chosen to do that + + + align:start position:0% +convention and I've chosen to do that +simply to save some minus signs in the + + align:start position:0% +simply to save some minus signs in the + + + align:start position:0% +simply to save some minus signs in the +development the usual convention defines + + align:start position:0% +development the usual convention defines + + + align:start position:0% +development the usual convention defines +currents in a two-port being into the + + align:start position:0% +currents in a two-port being into the + + + align:start position:0% +currents in a two-port being into the +network uh the way I've defined my + + align:start position:0% +network uh the way I've defined my + + + align:start position:0% +network uh the way I've defined my +shortcircuit transfer admittance is + + align:start position:0% +shortcircuit transfer admittance is + + + align:start position:0% +shortcircuit transfer admittance is +considering the current out of the the + + align:start position:0% +considering the current out of the the + + + align:start position:0% +considering the current out of the the +network and say my reason for doing that + + align:start position:0% +network and say my reason for doing that + + + align:start position:0% +network and say my reason for doing that +is is just that it saves some minus + + align:start position:0% +is is just that it saves some minus + + + align:start position:0% +is is just that it saves some minus +signs in the development and hopefully + + align:start position:0% +signs in the development and hopefully + + + align:start position:0% +signs in the development and hopefully +some confusion I've I've always found + + align:start position:0% +some confusion I've I've always found + + + align:start position:0% +some confusion I've I've always found +that that I work a little bit better + + align:start position:0% +that that I work a little bit better + + + align:start position:0% +that that I work a little bit better +with fewer minus sign so that's the + + align:start position:0% +with fewer minus sign so that's the + + + align:start position:0% +with fewer minus sign so that's the +reason for violating standard + + align:start position:0% +reason for violating standard + + + align:start position:0% +reason for violating standard +conventions in in this + + align:start position:0% +conventions in in this + + + align:start position:0% +conventions in in this +development the effect of the first + + align:start position:0% +development the effect of the first + + + align:start position:0% +development the effect of the first +stage on incremental signals is simply + + align:start position:0% +stage on incremental signals is simply + + + align:start position:0% +stage on incremental signals is simply +to inject or remove a current from this + + align:start position:0% +to inject or remove a current from this + + + align:start position:0% +to inject or remove a current from this +sde that's proportional to an applied + + align:start position:0% +sde that's proportional to an applied + + + align:start position:0% +sde that's proportional to an applied +input voltage if the input transistors + + align:start position:0% +input voltage if the input transistors + + + align:start position:0% +input voltage if the input transistors +are perfectly matched under quient + + align:start position:0% +are perfectly matched under quient + + + align:start position:0% +are perfectly matched under quient +conditions The Collector current of this + + align:start position:0% +conditions The Collector current of this + + + align:start position:0% +conditions The Collector current of this +transistor is identically equal to the + + align:start position:0% +transistor is identically equal to the + + + align:start position:0% +transistor is identically equal to the +current ass assciated with this current + + align:start position:0% +current ass assciated with this current + + + align:start position:0% +current ass assciated with this current +Source if we then apply an incremental + + align:start position:0% +Source if we then apply an incremental + + + align:start position:0% +Source if we then apply an incremental +input voltage about the quient operating + + align:start position:0% +input voltage about the quient operating + + + align:start position:0% +input voltage about the quient operating +point of Z Volts for the input voltage + + align:start position:0% +point of Z Volts for the input voltage + + + align:start position:0% +point of Z Volts for the input voltage +that voltage effectively divides equally + + align:start position:0% +that voltage effectively divides equally + + + align:start position:0% +that voltage effectively divides equally +between the two input transistors + + align:start position:0% +between the two input transistors + + + align:start position:0% +between the two input transistors +consequently we get an incremental + + align:start position:0% +consequently we get an incremental + + + align:start position:0% +consequently we get an incremental +change in The Collector current of this + + align:start position:0% +change in The Collector current of this + + + align:start position:0% +change in The Collector current of this +transistor that's one/ half of the input + + align:start position:0% +transistor that's one/ half of the input + + + align:start position:0% +transistor that's one/ half of the input +voltage the amount of voltage that's + + align:start position:0% +voltage the amount of voltage that's + + + align:start position:0% +voltage the amount of voltage that's +applied to the base toit Junction of + + align:start position:0% +applied to the base toit Junction of + + + align:start position:0% +applied to the base toit Junction of +this transistor being 1/2 of the input + + align:start position:0% +this transistor being 1/2 of the input + + + align:start position:0% +this transistor being 1/2 of the input +voltage because of the symmetry of the + + align:start position:0% +voltage because of the symmetry of the + + + align:start position:0% +voltage because of the symmetry of the +circuit times the trans conductance of + + align:start position:0% +circuit times the trans conductance of + + + align:start position:0% +circuit times the trans conductance of +this transistor we assume that the trans + + align:start position:0% +this transistor we assume that the trans + + + align:start position:0% +this transistor we assume that the trans +conductances of the two input + + align:start position:0% +conductances of the two input + + + align:start position:0% +conductances of the two input +transistors are equal so the effect of + + align:start position:0% +transistors are equal so the effect of + + + align:start position:0% +transistors are equal so the effect of +the first stage is to Simply cause an + + align:start position:0% +the first stage is to Simply cause an + + + align:start position:0% +the first stage is to Simply cause an +incremental current at this node and the + + align:start position:0% +incremental current at this node and the + + + align:start position:0% +incremental current at this node and the +constant proportionality between that + + align:start position:0% +constant proportionality between that + + + align:start position:0% +constant proportionality between that +incremental current and the input + + align:start position:0% +incremental current and the input + + + align:start position:0% +incremental current and the input +voltage is simply GM / + + align:start position:0% +voltage is simply GM / + + + align:start position:0% +voltage is simply GM / +two we're then able to model the overall + + align:start position:0% +two we're then able to model the overall + + + align:start position:0% +two we're then able to model the overall +system as follows we can replace the + + align:start position:0% +system as follows we can replace the + + + align:start position:0% +system as follows we can replace the +differential Pair by a dependent current + + align:start position:0% +differential Pair by a dependent current + + + align:start position:0% +differential Pair by a dependent current +Source whose magnitude is gmvi / 2 so + + align:start position:0% +Source whose magnitude is gmvi / 2 so + + + align:start position:0% +Source whose magnitude is gmvi / 2 so +that's dependent current Source reflects + + align:start position:0% +that's dependent current Source reflects + + + align:start position:0% +that's dependent current Source reflects +the transmission from the input voltage + + align:start position:0% +the transmission from the input voltage + + + align:start position:0% +the transmission from the input voltage +to this current we + + align:start position:0% +to this current we + + + align:start position:0% +to this current we +combine these two admittances to get an + + align:start position:0% +combine these two admittances to get an + + + align:start position:0% +combine these two admittances to get an +admittance that's Yi + ya a uh the + + align:start position:0% +admittance that's Yi + ya a uh the + + + align:start position:0% +admittance that's Yi + ya a uh the +voltage across that admittance is VA and + + align:start position:0% +voltage across that admittance is VA and + + + align:start position:0% +voltage across that admittance is VA and +the output voltage as it was above is + + align:start position:0% +the output voltage as it was above is + + + align:start position:0% +the output voltage as it was above is +simply AI times that voltage V Suba we + + align:start position:0% +simply AI times that voltage V Suba we + + + align:start position:0% +simply AI times that voltage V Suba we +complete the minor Loop or model the + + align:start position:0% +complete the minor Loop or model the + + + align:start position:0% +complete the minor Loop or model the +effect of + + align:start position:0% +effect of + + + align:start position:0% +effect of +the two-port network as far as its + + align:start position:0% +the two-port network as far as its + + + align:start position:0% +the two-port network as far as its +feedback effect simply as a dependent + + align:start position:0% +feedback effect simply as a dependent + + + align:start position:0% +feedback effect simply as a dependent +generator whose magnitude is y subc + + align:start position:0% +generator whose magnitude is y subc + + + align:start position:0% +generator whose magnitude is y subc +times now vo recognizing that v o and VM + + align:start position:0% +times now vo recognizing that v o and VM + + + align:start position:0% +times now vo recognizing that v o and VM +are identical and so we represent the + + align:start position:0% +are identical and so we represent the + + + align:start position:0% +are identical and so we represent the +dependent generator associated with the + + align:start position:0% +dependent generator associated with the + + + align:start position:0% +dependent generator associated with the +two port in this way we've already taken + + align:start position:0% +two port in this way we've already taken + + + align:start position:0% +two port in this way we've already taken +care of the output admittance of the two + + align:start position:0% +care of the output admittance of the two + + + align:start position:0% +care of the output admittance of the two +ports since we've lumped it into this + + align:start position:0% +ports since we've lumped it into this + + + align:start position:0% +ports since we've lumped it into this +admittance we can then use this + + align:start position:0% +admittance we can then use this + + + align:start position:0% +admittance we can then use this +representation to determine what becomes + + align:start position:0% +representation to determine what becomes + + + align:start position:0% +representation to determine what becomes +the open loop transfer function of the + + align:start position:0% +the open loop transfer function of the + + + align:start position:0% +the open loop transfer function of the +operational amplifier we of course have + + align:start position:0% +operational amplifier we of course have + + + align:start position:0% +operational amplifier we of course have +considered the operational amplifier + + align:start position:0% +considered the operational amplifier + + + align:start position:0% +considered the operational amplifier +from an input applied to the + + align:start position:0% +from an input applied to the + + + align:start position:0% +from an input applied to the +differential input stage to the output + + align:start position:0% +differential input stage to the output + + + align:start position:0% +differential input stage to the output +of the amplifier so this is what we + + align:start position:0% +of the amplifier so this is what we + + + align:start position:0% +of the amplifier so this is what we +commonly consider the open loop transfer + + align:start position:0% +commonly consider the open loop transfer + + + align:start position:0% +commonly consider the open loop transfer +function of the operational + + align:start position:0% +function of the operational + + + align:start position:0% +function of the operational +amplifier we can most easily uh + + align:start position:0% +amplifier we can most easily uh + + + align:start position:0% +amplifier we can most easily uh +determine that quantity + + align:start position:0% +determine that quantity + + + align:start position:0% +determine that quantity +uh by first writing a node equation at + + align:start position:0% +uh by first writing a node equation at + + + align:start position:0% +uh by first writing a node equation at +this + + align:start position:0% +this + + + align:start position:0% +this +node and that's the equation shown here + + align:start position:0% +node and that's the equation shown here + + + align:start position:0% +node and that's the equation shown here +uh we have a current coming out of the + + align:start position:0% +uh we have a current coming out of the + + + align:start position:0% +uh we have a current coming out of the +node that's GM VI over two if we we can + + align:start position:0% +node that's GM VI over two if we we can + + + align:start position:0% +node that's GM VI over two if we we can +move that over to the left we get a + + align:start position:0% +move that over to the left we get a + + + align:start position:0% +move that over to the left we get a +minus gmvi over two on the left side of + + align:start position:0% +minus gmvi over two on the left side of + + + align:start position:0% +minus gmvi over two on the left side of +the equation uh there's a current going + + align:start position:0% +the equation uh there's a current going + + + align:start position:0% +the equation uh there's a current going +uh out of the node in question through + + align:start position:0% +uh out of the node in question through + + + align:start position:0% +uh out of the node in question through +the combined admittance Yi + ya a the + + align:start position:0% +the combined admittance Yi + ya a the + + + align:start position:0% +the combined admittance Yi + ya a the +voltage across that admittance is VA so + + align:start position:0% +voltage across that admittance is VA so + + + align:start position:0% +voltage across that admittance is VA so +we get a current through that combined + + align:start position:0% +we get a current through that combined + + + align:start position:0% +we get a current through that combined +admittance that's simply VA * + + align:start position:0% +admittance that's simply VA * + + + align:start position:0% +admittance that's simply VA * +yi+ ya a and we get a current into the + + align:start position:0% +yi+ ya a and we get a current into the + + + align:start position:0% +yi+ ya a and we get a current into the +node that's YC * V that represents the + + align:start position:0% +node that's YC * V that represents the + + + align:start position:0% +node that's YC * V that represents the +shortcircuit transfer admittance of our + + align:start position:0% +shortcircuit transfer admittance of our + + + align:start position:0% +shortcircuit transfer admittance of our +compensating two Port uh the second + + align:start position:0% +compensating two Port uh the second + + + align:start position:0% +compensating two Port uh the second +equation uh reflects the fact that V out + + align:start position:0% +equation uh reflects the fact that V out + + + align:start position:0% +equation uh reflects the fact that V out +is simply minus AI time VA the + + align:start position:0% +is simply minus AI time VA the + + + align:start position:0% +is simply minus AI time VA the +relationship for the dependent generator + + align:start position:0% +relationship for the dependent generator + + + align:start position:0% +relationship for the dependent generator +in the second stage rearranging terms we + + align:start position:0% +in the second stage rearranging terms we + + + align:start position:0% +in the second stage rearranging terms we +get 0 equal AI VA plus + + align:start position:0% +get 0 equal AI VA plus + + + align:start position:0% +get 0 equal AI VA plus +v and when we solve this set of + + align:start position:0% +v and when we solve this set of + + + align:start position:0% +v and when we solve this set of +equations for the output or input to + + align:start position:0% +equations for the output or input to + + + align:start position:0% +equations for the output or input to +Output transfer function we obtain GM + + align:start position:0% +Output transfer function we obtain GM + + + align:start position:0% +Output transfer function we obtain GM +over2 uh times AI over Yi + y a over 1 + + + align:start position:0% +over2 uh times AI over Yi + y a over 1 + + + + align:start position:0% +over2 uh times AI over Yi + y a over 1 + +AI y c over Yi + ya + + align:start position:0% +AI y c over Yi + ya + + + align:start position:0% +AI y c over Yi + ya +a there's a very nice physical + + align:start position:0% +a there's a very nice physical + + + align:start position:0% +a there's a very nice physical +significance associated with the terms + + align:start position:0% +significance associated with the terms + + + align:start position:0% +significance associated with the terms +in that final equation in particular + + align:start position:0% +in that final equation in particular + + + align:start position:0% +in that final equation in particular +let's consider the + + align:start position:0% +let's consider the + + + align:start position:0% +let's consider the +numerator here we have gm/ 2 * AI over + + align:start position:0% +numerator here we have gm/ 2 * AI over + + + align:start position:0% +numerator here we have gm/ 2 * AI over +Yi + ya + + align:start position:0% +Yi + ya + + + align:start position:0% +Yi + ya +a what's + + align:start position:0% +a what's + + + align:start position:0% +a what's +that well consider what would happen if + + align:start position:0% +that well consider what would happen if + + + align:start position:0% +that well consider what would happen if +we disabled the feedback network if we + + align:start position:0% +we disabled the feedback network if we + + + align:start position:0% +we disabled the feedback network if we +made YC equal to + + align:start position:0% +made YC equal to + + + align:start position:0% +made YC equal to +zero uh possibly by + + align:start position:0% +zero uh possibly by + + + align:start position:0% +zero uh possibly by +disconnecting + + align:start position:0% +disconnecting + + + align:start position:0% +disconnecting +uh the input Port of the compensating + + align:start position:0% +uh the input Port of the compensating + + + align:start position:0% +uh the input Port of the compensating +network from V out and simply shorting + + align:start position:0% +network from V out and simply shorting + + + align:start position:0% +network from V out and simply shorting +it that would of course disable this + + align:start position:0% +it that would of course disable this + + + align:start position:0% +it that would of course disable this +generator since VM would then be zero uh + + align:start position:0% +generator since VM would then be zero uh + + + align:start position:0% +generator since VM would then be zero uh +however we would keep the loading + + align:start position:0% +however we would keep the loading + + + align:start position:0% +however we would keep the loading +associated with the two-port network uh + + align:start position:0% +associated with the two-port network uh + + + align:start position:0% +associated with the two-port network uh +we lump that admittance y Suba with Y + + align:start position:0% +we lump that admittance y Suba with Y + + + align:start position:0% +we lump that admittance y Suba with Y +subi to say all we've done really is + + align:start position:0% +subi to say all we've done really is + + + align:start position:0% +subi to say all we've done really is +make YC uh or the magnitude of this + + align:start position:0% +make YC uh or the magnitude of this + + + align:start position:0% +make YC uh or the magnitude of this +generator equal to zero and then + + align:start position:0% +generator equal to zero and then + + + align:start position:0% +generator equal to zero and then +calculate the gain that results in the + + align:start position:0% +calculate the gain that results in the + + + align:start position:0% +calculate the gain that results in the +absence of minor Loop feedback disabling + + align:start position:0% +absence of minor Loop feedback disabling + + + align:start position:0% +absence of minor Loop feedback disabling +this generator effectively makes F in + + align:start position:0% +this generator effectively makes F in + + + align:start position:0% +this generator effectively makes F in +the minor Loop zero well the gain would + + align:start position:0% +the minor Loop zero well the gain would + + + align:start position:0% +the minor Loop zero well the gain would +simply be gm/ 2 that gets us to a + + align:start position:0% +simply be gm/ 2 that gets us to a + + + align:start position:0% +simply be gm/ 2 that gets us to a +current times Yi + ya a I'm sorry + + align:start position:0% +current times Yi + ya a I'm sorry + + + align:start position:0% +current times Yi + ya a I'm sorry +divided by Yi + ya a that gets us the + + align:start position:0% +divided by Yi + ya a that gets us the + + + align:start position:0% +divided by Yi + ya a that gets us the +voltage at this point we multiply that + + align:start position:0% +voltage at this point we multiply that + + + align:start position:0% +voltage at this point we multiply that +voltage by a sub I to get the overall + + align:start position:0% +voltage by a sub I to get the overall + + + align:start position:0% +voltage by a sub I to get the overall +output voltage so the physical + + align:start position:0% +output voltage so the physical + + + align:start position:0% +output voltage so the physical +significance of the quantity gm/ 2 * AI + + align:start position:0% +significance of the quantity gm/ 2 * AI + + + align:start position:0% +significance of the quantity gm/ 2 * AI +over Yi plus ya a is that it's the open + + align:start position:0% +over Yi plus ya a is that it's the open + + + align:start position:0% +over Yi plus ya a is that it's the open +loop voltage gain of the operational + + align:start position:0% +loop voltage gain of the operational + + + align:start position:0% +loop voltage gain of the operational +amplifier with the minor Loop disabled + + align:start position:0% +amplifier with the minor Loop disabled + + + align:start position:0% +amplifier with the minor Loop disabled +but considering the loading that the + + align:start position:0% +but considering the loading that the + + + align:start position:0% +but considering the loading that the +output side of the two-port compensating + + align:start position:0% +output side of the two-port compensating + + + align:start position:0% +output side of the two-port compensating +Network applies to the second stage we + + align:start position:0% +Network applies to the second stage we + + + align:start position:0% +Network applies to the second stage we +see that because the quantity y Suba + + align:start position:0% +see that because the quantity y Suba + + + align:start position:0% +see that because the quantity y Suba +appears in the expression the + + align:start position:0% +appears in the expression the + + + align:start position:0% +appears in the expression the +denominator has a very familiar looking + + align:start position:0% +denominator has a very familiar looking + + + align:start position:0% +denominator has a very familiar looking +feedback Form 1 plus something it'd be + + align:start position:0% +feedback Form 1 plus something it'd be + + + align:start position:0% +feedback Form 1 plus something it'd be +very reassuring if that's something were + + align:start position:0% +very reassuring if that's something were + + + align:start position:0% +very reassuring if that's something were +minus the loop transmission so let's + + align:start position:0% +minus the loop transmission so let's + + + align:start position:0% +minus the loop transmission so let's +consider the quantity a subi times y c + + align:start position:0% +consider the quantity a subi times y c + + + align:start position:0% +consider the quantity a subi times y c +over Yi + ya a well as we suspected + + align:start position:0% +over Yi + ya a well as we suspected + + + align:start position:0% +over Yi + ya a well as we suspected +that's precisely the negative of a loop + + align:start position:0% +that's precisely the negative of a loop + + + align:start position:0% +that's precisely the negative of a loop +transmission and in particular it's the + + align:start position:0% +transmission and in particular it's the + + + align:start position:0% +transmission and in particular it's the +transmission around the minor Loop uh + + align:start position:0% +transmission around the minor Loop uh + + + align:start position:0% +transmission around the minor Loop uh +let's consider the minor Loop Loop if we + + align:start position:0% +let's consider the minor Loop Loop if we + + + align:start position:0% +let's consider the minor Loop Loop if we +forget about a driving input to the + + align:start position:0% +forget about a driving input to the + + + align:start position:0% +forget about a driving input to the +overall system here uh around the minor + + align:start position:0% +overall system here uh around the minor + + + align:start position:0% +overall system here uh around the minor +Loop we get a product y Sub C divided by + + align:start position:0% +Loop we get a product y Sub C divided by + + + align:start position:0% +Loop we get a product y Sub C divided by +this admittance to get us a voltage here + + align:start position:0% +this admittance to get us a voltage here + + + align:start position:0% +this admittance to get us a voltage here +so we get a y c over Yi + y a we + + align:start position:0% +so we get a y c over Yi + y a we + + + align:start position:0% +so we get a y c over Yi + y a we +multiply that by a sub I and if we keep + + align:start position:0% +multiply that by a sub I and if we keep + + + align:start position:0% +multiply that by a sub I and if we keep +track of things there's a minus sign + + align:start position:0% +track of things there's a minus sign + + + align:start position:0% +track of things there's a minus sign +associated with that Loop + + align:start position:0% +associated with that Loop + + + align:start position:0% +associated with that Loop +transmission so the quantity y c over Yi + + align:start position:0% +transmission so the quantity y c over Yi + + + align:start position:0% +transmission so the quantity y c over Yi ++ ya a all multiplied by AI is the + + align:start position:0% ++ ya a all multiplied by AI is the + + + align:start position:0% ++ ya a all multiplied by AI is the +negative of the transmission around the + + align:start position:0% +negative of the transmission around the + + + align:start position:0% +negative of the transmission around the +minor + + align:start position:0% +minor + + + align:start position:0% +minor +Loop so we have the numerator of this + + align:start position:0% +Loop so we have the numerator of this + + + align:start position:0% +Loop so we have the numerator of this +expression being the gain the amplifier + + align:start position:0% +expression being the gain the amplifier + + + align:start position:0% +expression being the gain the amplifier +would have if the monitor Loop were + + align:start position:0% +would have if the monitor Loop were + + + align:start position:0% +would have if the monitor Loop were +disabled but its loading were considered + + align:start position:0% +disabled but its loading were considered + + + align:start position:0% +disabled but its loading were considered +the denominator of of this expression is + + align:start position:0% +the denominator of of this expression is + + + align:start position:0% +the denominator of of this expression is +one minus the loop transmission of the + + align:start position:0% +one minus the loop transmission of the + + + align:start position:0% +one minus the loop transmission of the +minor + + align:start position:0% +minor + + + align:start position:0% +minor +Loop and again there's the familiar + + align:start position:0% +Loop and again there's the familiar + + + align:start position:0% +Loop and again there's the familiar +limiting cases this goes right back to + + align:start position:0% +limiting cases this goes right back to + + + align:start position:0% +limiting cases this goes right back to +what we did earlier in our general + + align:start position:0% +what we did earlier in our general + + + align:start position:0% +what we did earlier in our general +discussion of feedback compensation + + align:start position:0% +discussion of feedback compensation + + + align:start position:0% +discussion of feedback compensation +let's consider the quantity V out over + + align:start position:0% +let's consider the quantity V out over + + + align:start position:0% +let's consider the quantity V out over +VI the open loop transfer function of + + align:start position:0% +VI the open loop transfer function of + + + align:start position:0% +VI the open loop transfer function of +the amplifier for those two limiting + + align:start position:0% +the amplifier for those two limiting + + + align:start position:0% +the amplifier for those two limiting +cases well if the transmission around + + align:start position:0% +cases well if the transmission around + + + align:start position:0% +cases well if the transmission around +the minor Loop the magnitude of the + + align:start position:0% +the minor Loop the magnitude of the + + + align:start position:0% +the minor Loop the magnitude of the +transmission around the minor Loop the + + align:start position:0% +transmission around the minor Loop the + + + align:start position:0% +transmission around the minor Loop the +AI YC over Yi + ya a product is much + + align:start position:0% +AI YC over Yi + ya a product is much + + + align:start position:0% +AI YC over Yi + ya a product is much +larger than one in other words if this + + align:start position:0% +larger than one in other words if this + + + align:start position:0% +larger than one in other words if this +term is Big compared to one in the + + align:start position:0% +term is Big compared to one in the + + + align:start position:0% +term is Big compared to one in the +denominator we can ignore the one the + + align:start position:0% +denominator we can ignore the one the + + + align:start position:0% +denominator we can ignore the one the +AIS cancel out the Yi plus y a cancel + + align:start position:0% +AIS cancel out the Yi plus y a cancel + + + align:start position:0% +AIS cancel out the Yi plus y a cancel +out and under those conditions the open + + align:start position:0% +out and under those conditions the open + + + align:start position:0% +out and under those conditions the open +loop transfer function of the of the + + align:start position:0% +loop transfer function of the of the + + + align:start position:0% +loop transfer function of the of the +amplifier is simply GM / 2 * y Sub + + align:start position:0% +amplifier is simply GM / 2 * y Sub + + + align:start position:0% +amplifier is simply GM / 2 * y Sub +C uh in the other limiting case where + + align:start position:0% +C uh in the other limiting case where + + + align:start position:0% +C uh in the other limiting case where +the transmission around the minor Loop + + align:start position:0% +the transmission around the minor Loop + + + align:start position:0% +the transmission around the minor Loop +is small compared to one or the + + align:start position:0% +is small compared to one or the + + + align:start position:0% +is small compared to one or the +magnitude of the transmission around the + + align:start position:0% +magnitude of the transmission around the + + + align:start position:0% +magnitude of the transmission around the +minor Loop is small compared to one uh + + align:start position:0% +minor Loop is small compared to one uh + + + align:start position:0% +minor Loop is small compared to one uh +we find out that the input to Output + + align:start position:0% +we find out that the input to Output + + + align:start position:0% +we find out that the input to Output +transfer function for the amplifier it's + + align:start position:0% +transfer function for the amplifier it's + + + align:start position:0% +transfer function for the amplifier it's +open loop Loop transfer function uh is + + align:start position:0% +open loop Loop transfer function uh is + + + align:start position:0% +open loop Loop transfer function uh is +simply that that would result uh with + + align:start position:0% +simply that that would result uh with + + + align:start position:0% +simply that that would result uh with +the minor Loop disabled that's the + + align:start position:0% +the minor Loop disabled that's the + + + align:start position:0% +the minor Loop disabled that's the +effect of of having the transmission + + align:start position:0% +effect of of having the transmission + + + align:start position:0% +effect of of having the transmission +around the minor Loop small uh and in + + align:start position:0% +around the minor Loop small uh and in + + + align:start position:0% +around the minor Loop small uh and in +that case we get GM over2 times AI over + + align:start position:0% +that case we get GM over2 times AI over + + + align:start position:0% +that case we get GM over2 times AI over +Yi plus + + align:start position:0% +Yi plus + + + align:start position:0% +Yi plus +ya well exactly as we did in our general + + align:start position:0% +ya well exactly as we did in our general + + + align:start position:0% +ya well exactly as we did in our general +discussion of minor Loop compensation a + + align:start position:0% +discussion of minor Loop compensation a + + + align:start position:0% +discussion of minor Loop compensation a +very convenient way to to look at this + + align:start position:0% +very convenient way to to look at this + + + align:start position:0% +very convenient way to to look at this +and a very nice way to do design is to + + align:start position:0% +and a very nice way to do design is to + + + align:start position:0% +and a very nice way to do design is to +draw these two quantities + + align:start position:0% +draw these two quantities + + + align:start position:0% +draw these two quantities +we draw G subm over 2 y Sub C which is + + align:start position:0% +we draw G subm over 2 y Sub C which is + + + align:start position:0% +we draw G subm over 2 y Sub C which is +the approximation that we would use when + + align:start position:0% +the approximation that we would use when + + + align:start position:0% +the approximation that we would use when +the transmission around the minor Loop + + align:start position:0% +the transmission around the minor Loop + + + align:start position:0% +the transmission around the minor Loop +has a magnitude large compared to + + align:start position:0% +has a magnitude large compared to + + + align:start position:0% +has a magnitude large compared to +one and we similarly draw the open loop + + align:start position:0% +one and we similarly draw the open loop + + + align:start position:0% +one and we similarly draw the open loop +gain of the amplifier in the absence of + + align:start position:0% +gain of the amplifier in the absence of + + + align:start position:0% +gain of the amplifier in the absence of +minor Loop feedback but considering the + + align:start position:0% +minor Loop feedback but considering the + + + align:start position:0% +minor Loop feedback but considering the +loading associated with the two-port + + align:start position:0% +loading associated with the two-port + + + align:start position:0% +loading associated with the two-port +feedback Network that quantity is of + + align:start position:0% +feedback Network that quantity is of + + + align:start position:0% +feedback Network that quantity is of +course G sub M AI over 2 Yi + y a we + + align:start position:0% +course G sub M AI over 2 Yi + y a we + + + align:start position:0% +course G sub M AI over 2 Yi + y a we +draw those two quantities on our usual B + + align:start position:0% +draw those two quantities on our usual B + + + align:start position:0% +draw those two quantities on our usual B +plot + + align:start position:0% +plot + + + align:start position:0% +plot +coordinates and we look for the the two + + align:start position:0% +coordinates and we look for the the two + + + align:start position:0% +coordinates and we look for the the two +look to see which curve is is greater in + + align:start position:0% +look to see which curve is is greater in + + + align:start position:0% +look to see which curve is is greater in +magnitude uh if in fact for example this + + align:start position:0% +magnitude uh if in fact for example this + + + align:start position:0% +magnitude uh if in fact for example this +quantity the open loop transfer function + + align:start position:0% +quantity the open loop transfer function + + + align:start position:0% +quantity the open loop transfer function +of the amplifier and the absence of + + align:start position:0% +of the amplifier and the absence of + + + align:start position:0% +of the amplifier and the absence of +minor Loop feedback is greater than this + + align:start position:0% +minor Loop feedback is greater than this + + + align:start position:0% +minor Loop feedback is greater than this +quantity uh the Imp ation which we can + + align:start position:0% +quantity uh the Imp ation which we can + + + align:start position:0% +quantity uh the Imp ation which we can +get by by + + align:start position:0% +get by by + + + align:start position:0% +get by by +simply multiplying both sides of this + + align:start position:0% +simply multiplying both sides of this + + + align:start position:0% +simply multiplying both sides of this +equation by the reciprocal of this term + + align:start position:0% +equation by the reciprocal of this term + + + align:start position:0% +equation by the reciprocal of this term +is that the magnitude of the + + align:start position:0% +is that the magnitude of the + + + align:start position:0% +is that the magnitude of the +transmission around the minor Loop is + + align:start position:0% +transmission around the minor Loop is + + + align:start position:0% +transmission around the minor Loop is +large compared to one if that's true our + + align:start position:0% +large compared to one if that's true our + + + align:start position:0% +large compared to one if that's true our +earlier approximation tells us that we + + align:start position:0% +earlier approximation tells us that we + + + align:start position:0% +earlier approximation tells us that we +use this as our estimate of the open + + align:start position:0% +use this as our estimate of the open + + + align:start position:0% +use this as our estimate of the open +loop transfer function of the amplifier + + align:start position:0% +loop transfer function of the amplifier + + + align:start position:0% +loop transfer function of the amplifier +it's exactly the sort of thing that we + + align:start position:0% +it's exactly the sort of thing that we + + + align:start position:0% +it's exactly the sort of thing that we +did over + + align:start position:0% +did over + + + align:start position:0% +did over +here uh in this case this curve would be + + align:start position:0% +here uh in this case this curve would be + + + align:start position:0% +here uh in this case this curve would be +GM over 2 y Sub + + align:start position:0% +GM over 2 y Sub + + + align:start position:0% +GM over 2 y Sub +C uh so we can we can show what would + + align:start position:0% +C uh so we can we can show what would + + + align:start position:0% +C uh so we can we can show what would +happen for our operational amplifier + + align:start position:0% +happen for our operational amplifier + + + align:start position:0% +happen for our operational amplifier +this + + align:start position:0% +this + + + align:start position:0% +this +curve would + + align:start position:0% +curve would + + + align:start position:0% +curve would +be G + + align:start position:0% +be G + + + align:start position:0% +be G +subm over 2 y Sub + + align:start position:0% +subm over 2 y Sub + + + align:start position:0% +subm over 2 y Sub +C and this curve would be not not this + + align:start position:0% +C and this curve would be not not this + + + align:start position:0% +C and this curve would be not not this +quantity but rather + + align:start position:0% +quantity but rather + + + align:start position:0% +quantity but rather +G subm over 2 + + align:start position:0% +G subm over 2 + + + align:start position:0% +G subm over 2 +times + + align:start position:0% +times + + + align:start position:0% +times +AI over Yi plus ya a so we plot those + + align:start position:0% +AI over Yi plus ya a so we plot those + + + align:start position:0% +AI over Yi plus ya a so we plot those +two quantities once again as in our + + align:start position:0% +two quantities once again as in our + + + align:start position:0% +two quantities once again as in our +general discussion of monor loop + + align:start position:0% +general discussion of monor loop + + + align:start position:0% +general discussion of monor loop +feedback we'd estimate the overall + + align:start position:0% +feedback we'd estimate the overall + + + align:start position:0% +feedback we'd estimate the overall +forward path transfer function of our + + align:start position:0% +forward path transfer function of our + + + align:start position:0% +forward path transfer function of our +system in this case uh the open loop + + align:start position:0% +system in this case uh the open loop + + + align:start position:0% +system in this case uh the open loop +transfer function of the operational + + align:start position:0% +transfer function of the operational + + + align:start position:0% +transfer function of the operational +amplifier as simply the lower of those + + align:start position:0% +amplifier as simply the lower of those + + + align:start position:0% +amplifier as simply the lower of those +two curves at all + + align:start position:0% + + + + align:start position:0% + +frequencies we'll find out that this + + align:start position:0% +frequencies we'll find out that this + + + align:start position:0% +frequencies we'll find out that this +sort of estimate works very well for at + + align:start position:0% +sort of estimate works very well for at + + + align:start position:0% +sort of estimate works very well for at +least one available operational + + align:start position:0% +least one available operational + + + align:start position:0% +least one available operational +amplifier in fact most modern + + align:start position:0% +amplifier in fact most modern + + + align:start position:0% +amplifier in fact most modern +operational amplifiers the ones that are + + align:start position:0% +operational amplifiers the ones that are + + + align:start position:0% +operational amplifiers the ones that are +currently being designed use this sort + + align:start position:0% +currently being designed use this sort + + + align:start position:0% +currently being designed use this sort +of two two-stage topology several of the + + align:start position:0% +of two two-stage topology several of the + + + align:start position:0% +of two two-stage topology several of the +available ones allow the user to select + + align:start position:0% +available ones allow the user to select + + + align:start position:0% +available ones allow the user to select +the compensating element we'll find out + + align:start position:0% +the compensating element we'll find out + + + align:start position:0% +the compensating element we'll find out +that that gives us a very very powerful + + align:start position:0% +that that gives us a very very powerful + + + align:start position:0% +that that gives us a very very powerful +handle on the performance of the + + align:start position:0% +handle on the performance of the + + + align:start position:0% +handle on the performance of the +operational + + align:start position:0% +operational + + + align:start position:0% +operational +amplifier there are a number of popular + + align:start position:0% +amplifier there are a number of popular + + + align:start position:0% +amplifier there are a number of popular +operational amplifiers which do use + + align:start position:0% +operational amplifiers which do use + + + align:start position:0% +operational amplifiers which do use +minor Loop compensation say a good + + align:start position:0% +minor Loop compensation say a good + + + align:start position:0% +minor Loop compensation say a good +example of that is the + + align:start position:0% +example of that is the + + + align:start position:0% +example of that is the +741 and it's a fine amplifier in certain + + align:start position:0% +741 and it's a fine amplifier in certain + + + align:start position:0% +741 and it's a fine amplifier in certain +applications but it really doesn't have + + align:start position:0% +applications but it really doesn't have + + + align:start position:0% +applications but it really doesn't have +anywhere near the flexibility of those + + align:start position:0% +anywhere near the flexibility of those + + + align:start position:0% +anywhere near the flexibility of those +amplifiers that we're able to compensate + + align:start position:0% +amplifiers that we're able to compensate + + + align:start position:0% +amplifiers that we're able to compensate +ourselves and in fact I feel that one of + + align:start position:0% +ourselves and in fact I feel that one of + + + align:start position:0% +ourselves and in fact I feel that one of +the reasons for the popularity of the + + align:start position:0% +the reasons for the popularity of the + + + align:start position:0% +the reasons for the popularity of the +741 is simply that an awful lot of + + align:start position:0% +741 is simply that an awful lot of + + + align:start position:0% +741 is simply that an awful lot of +people who are designing with + + align:start position:0% +people who are designing with + + + align:start position:0% +people who are designing with +operational amplifiers have haven't made + + align:start position:0% +operational amplifiers have haven't made + + + align:start position:0% +operational amplifiers have haven't made +the effort to learn how to compensate + + align:start position:0% +the effort to learn how to compensate + + + align:start position:0% +the effort to learn how to compensate +those amplifiers themselves hopefully + + align:start position:0% +those amplifiers themselves hopefully + + + align:start position:0% +those amplifiers themselves hopefully +this sort of a development will will + + align:start position:0% +this sort of a development will will + + + align:start position:0% +this sort of a development will will +help in fact because of the ease of + + align:start position:0% +help in fact because of the ease of + + + align:start position:0% +help in fact because of the ease of +applying this approximation and as we'll + + align:start position:0% +applying this approximation and as we'll + + + align:start position:0% +applying this approximation and as we'll +see next time because of the very good + + align:start position:0% +see next time because of the very good + + + align:start position:0% +see next time because of the very good +results that we get using the + + align:start position:0% +results that we get using the + + + align:start position:0% +results that we get using the +approximation why we're able to very + + align:start position:0% +approximation why we're able to very + + + align:start position:0% +approximation why we're able to very +readily determine sort of a a quote + + align:start position:0% +readily determine sort of a a quote + + + align:start position:0% +readily determine sort of a a quote +Optimum compensation for many many + + align:start position:0% +Optimum compensation for many many + + + align:start position:0% +Optimum compensation for many many +feedback configurations using these + + align:start position:0% +feedback configurations using these + + + align:start position:0% +feedback configurations using these +sorts of operational amplifiers so I'd + + align:start position:0% +sorts of operational amplifiers so I'd + + + align:start position:0% +sorts of operational amplifiers so I'd +like to look into that next time and do + + align:start position:0% +like to look into that next time and do + + + align:start position:0% +like to look into that next time and do +a an actual example using a commercially + + align:start position:0% +a an actual example using a commercially + + + align:start position:0% +a an actual example using a commercially +available operational amplifier + + align:start position:0% +available operational amplifier + + + align:start position:0% +available operational amplifier +determining the kinds of compensation we + + align:start position:0% +determining the kinds of compensation we + + + align:start position:0% +determining the kinds of compensation we +should use as a function of application + + align:start position:0% +should use as a function of application + + + align:start position:0% +should use as a function of application +thank you \ No newline at end of file diff --git a/IGk-7EKR35A.txt b/IGk-7EKR35A.txt new file mode 100644 index 0000000000000000000000000000000000000000..bf74764f5749ccad4be956bbcca958746470fce7 --- /dev/null +++ b/IGk-7EKR35A.txt @@ -0,0 +1,1515 @@ +align:start position:0% + +hi everyone welcome back so in this + + align:start position:0% +hi everyone welcome back so in this + + + align:start position:0% +hi everyone welcome back so in this +problem I'd like to take a look at + + align:start position:0% +problem I'd like to take a look at + + + align:start position:0% +problem I'd like to take a look at +convolution in green formula and + + align:start position:0% +convolution in green formula and + + + align:start position:0% +convolution in green formula and +specifically for part one we're just + + align:start position:0% +specifically for part one we're just + + + align:start position:0% +specifically for part one we're just +asked to compute the convolution of t + + align:start position:0% +asked to compute the convolution of t + + + align:start position:0% +asked to compute the convolution of t +with itself T in the second part we're + + align:start position:0% +with itself T in the second part we're + + + align:start position:0% +with itself T in the second part we're +asked to conf compute the convolution of + + align:start position:0% +asked to conf compute the convolution of + + + align:start position:0% +asked to conf compute the convolution of +e to Theus KT with another exponential e + + align:start position:0% +e to Theus KT with another exponential e + + + align:start position:0% +e to Theus KT with another exponential e +to the A and then in Part B were to use + + align:start position:0% +to the A and then in Part B were to use + + + align:start position:0% +to the A and then in Part B were to use +the result from part A as well as + + align:start position:0% +the result from part A as well as + + + align:start position:0% +the result from part A as well as +Green's formula to solve x do plus KX = + + align:start position:0% +Green's formula to solve x do plus KX = + + + align:start position:0% +Green's formula to solve x do plus KX = +e to the A and specifically we're + + align:start position:0% +e to the A and specifically we're + + + align:start position:0% +e to the A and specifically we're +interested in the rest initial condition + + align:start position:0% +interested in the rest initial condition + + + align:start position:0% +interested in the rest initial condition +solution to this formula okay so I'll + + align:start position:0% +solution to this formula okay so I'll + + + align:start position:0% +solution to this formula okay so I'll +let you think about this problem and + + align:start position:0% +let you think about this problem and + + + align:start position:0% +let you think about this problem and +I'll be back in a minute + + align:start position:0% + + + + align:start position:0% + +hi everyone welcome back okay so for + + align:start position:0% +hi everyone welcome back okay so for + + + align:start position:0% +hi everyone welcome back okay so for +part one we're asked to compute the + + align:start position:0% +part one we're asked to compute the + + + align:start position:0% +part one we're asked to compute the +convolution of two functions t with + + align:start position:0% +convolution of two functions t with + + + align:start position:0% +convolution of two functions t with +itself and I'll just quickly write down + + align:start position:0% +itself and I'll just quickly write down + + + align:start position:0% +itself and I'll just quickly write down +the formula for a convolution so if I + + align:start position:0% +the formula for a convolution so if I + + + align:start position:0% +the formula for a convolution so if I +have two + + align:start position:0% +have two + + + align:start position:0% +have two +functions f and + + align:start position:0% +functions f and + + + align:start position:0% +functions f and +g then the convolution is defined as in + + align:start position:0% +g then the convolution is defined as in + + + align:start position:0% +g then the convolution is defined as in +this case the integral from zero to T of + + align:start position:0% +this case the integral from zero to T of + + + align:start position:0% +this case the integral from zero to T of +f so the function f evaluated at we're + + align:start position:0% +f so the function f evaluated at we're + + + align:start position:0% +f so the function f evaluated at we're +going to use to as the integration + + align:start position:0% +going to use to as the integration + + + align:start position:0% +going to use to as the integration +variable multiplied by G T minus + + align:start position:0% +variable multiplied by G T minus + + + align:start position:0% +variable multiplied by G T minus +to D + + align:start position:0% +to D + + + align:start position:0% +to D +to so notice how the variable T appears + + align:start position:0% +to so notice how the variable T appears + + + align:start position:0% +to so notice how the variable T appears +in two places in this uh formula it + + align:start position:0% +in two places in this uh formula it + + + align:start position:0% +in two places in this uh formula it +appears in one place in the argument of + + align:start position:0% +appears in one place in the argument of + + + align:start position:0% +appears in one place in the argument of +G and it appears in the bound of + + align:start position:0% +G and it appears in the bound of + + + align:start position:0% +G and it appears in the bound of +integration meanwhile too is the Integra + + align:start position:0% +integration meanwhile too is the Integra + + + align:start position:0% +integration meanwhile too is the Integra +in uh it's the variable we're + + align:start position:0% +in uh it's the variable we're + + + align:start position:0% +in uh it's the variable we're +integrating over and T appears in two + + align:start position:0% +integrating over and T appears in two + + + align:start position:0% +integrating over and T appears in two +places as well one in F and one in G + + align:start position:0% + + + + align:start position:0% + +okay so if we're interested in t + + align:start position:0% +okay so if we're interested in t + + + align:start position:0% +okay so if we're interested in t +convolved with + + align:start position:0% + + + + align:start position:0% + +t we have the integral from 0 to + + align:start position:0% +t we have the integral from 0 to + + + align:start position:0% +t we have the integral from 0 to +T + + align:start position:0% +T + + + align:start position:0% +T +of to + + align:start position:0% +of to + + + align:start position:0% +of to +times T minus + + align:start position:0% +times T minus + + + align:start position:0% +times T minus +to so notice how f is just T and G is T + + align:start position:0% +to so notice how f is just T and G is T + + + align:start position:0% +to so notice how f is just T and G is T +so when we insert to and T minus ta into + + align:start position:0% +so when we insert to and T minus ta into + + + align:start position:0% +so when we insert to and T minus ta into +the the function we end up just getting + + align:start position:0% +the the function we end up just getting + + + align:start position:0% +the the function we end up just getting +to time T minus ta + + align:start position:0% + + + + align:start position:0% + +DT and just expanding this out we have t + + align:start position:0% +DT and just expanding this out we have t + + + align:start position:0% +DT and just expanding this out we have t +* + + align:start position:0% +* + + + align:start position:0% +* +to minus to^ 2 D + + align:start position:0% +to minus to^ 2 D + + + align:start position:0% +to minus to^ 2 D +to so in the integral the variable T + + align:start position:0% +to so in the integral the variable T + + + align:start position:0% +to so in the integral the variable T +always appears just as a + + align:start position:0% + + + + align:start position:0% + +constant so in this case we have t to + + align:start position:0% +constant so in this case we have t to + + + align:start position:0% +constant so in this case we have t to +integrated becomes t^2 over 2 when I + + align:start position:0% +integrated becomes t^2 over 2 when I + + + align:start position:0% +integrated becomes t^2 over 2 when I +integrate from0 to uh t + + align:start position:0% +integrate from0 to uh t + + + align:start position:0% +integrate from0 to uh t +t^ squar integrates to + + align:start position:0% +t^ squar integrates to + + + align:start position:0% +t^ squar integrates to +1/3 T + + align:start position:0% + + + + align:start position:0% + +cubed and zero drops out from the other + + align:start position:0% +cubed and zero drops out from the other + + + align:start position:0% +cubed and zero drops out from the other +end of the integral so we end up with t + + align:start position:0% +end of the integral so we end up with t + + + align:start position:0% +end of the integral so we end up with t +cubed 12 - + + align:start position:0% +cubed 12 - + + + align:start position:0% +cubed 12 - +1/3 which is equal to 1 16 T + + align:start position:0% +1/3 which is equal to 1 16 T + + + align:start position:0% +1/3 which is equal to 1 16 T +cubed okay so there's the answer we're + + align:start position:0% +cubed okay so there's the answer we're + + + align:start position:0% +cubed okay so there's the answer we're +looking for for Part B or for question + + align:start position:0% +looking for for Part B or for question + + + align:start position:0% +looking for for Part B or for question +two again we have another computation to + + align:start position:0% +two again we have another computation to + + + align:start position:0% +two again we have another computation to +do so we have more integrals to work + + align:start position:0% + + + + align:start position:0% + +out and in this case it's two + + align:start position:0% + + + + align:start position:0% + +exponentials so we have 0 to + + align:start position:0% +exponentials so we have 0 to + + + align:start position:0% +exponentials so we have 0 to +T the first one's going to be e to the + + align:start position:0% +T the first one's going to be e to the + + + align:start position:0% +T the first one's going to be e to the +KT + + align:start position:0% +KT + + + align:start position:0% +KT +sorry e to the K + + align:start position:0% + + + + align:start position:0% + +to and the second one is e to the A T + + align:start position:0% +to and the second one is e to the A T + + + align:start position:0% +to and the second one is e to the A T +minus to + + align:start position:0% + + + + align:start position:0% + +D so I can just expand things out and I + + align:start position:0% +D so I can just expand things out and I + + + align:start position:0% +D so I can just expand things out and I +get e to the a + + align:start position:0% +get e to the a + + + align:start position:0% +get e to the a +t time e to the minus uh + + align:start position:0% +t time e to the minus uh + + + align:start position:0% +t time e to the minus uh +A+ + + align:start position:0% +A+ + + + align:start position:0% +A+ +K to D + + align:start position:0% +K to D + + + align:start position:0% +K to D +to 0 to + + align:start position:0% +to 0 to + + + align:start position:0% +to 0 to +T and again because T is just a dummy + + align:start position:0% +T and again because T is just a dummy + + + align:start position:0% +T and again because T is just a dummy +variable in this integral we're not + + align:start position:0% +variable in this integral we're not + + + align:start position:0% +variable in this integral we're not +integrating over T I can just think of e + + align:start position:0% +integrating over T I can just think of e + + + align:start position:0% +integrating over T I can just think of e +to the a t as a constant so I'm really + + align:start position:0% +to the a t as a constant so I'm really + + + align:start position:0% +to the a t as a constant so I'm really +just integrating the function e to the + + align:start position:0% +just integrating the function e to the + + + align:start position:0% +just integrating the function e to the +minus a plus K + + align:start position:0% + + + + align:start position:0% + +to and when I integrate this function I + + align:start position:0% +to and when I integrate this function I + + + align:start position:0% +to and when I integrate this function I +get one + + align:start position:0% + + + + align:start position:0% + +over minus a + k eus a + + + align:start position:0% +over minus a + k eus a + + + + align:start position:0% +over minus a + k eus a + +k to evaluated at the + + align:start position:0% +k to evaluated at the + + + align:start position:0% +k to evaluated at the +bounds 0 and + + align:start position:0% + + + + align:start position:0% + +P so the negative sign here just flips + + align:start position:0% +P so the negative sign here just flips + + + align:start position:0% +P so the negative sign here just flips +the + + align:start position:0% +the + + + align:start position:0% +the +bounds so a plus + + align:start position:0% + + + + align:start position:0% + +K substituting in zero just gives us + + align:start position:0% + + + + align:start position:0% + +one and then substituting in t gives us + + align:start position:0% +one and then substituting in t gives us + + + align:start position:0% +one and then substituting in t gives us +e to the + + align:start position:0% +e to the + + + align:start position:0% +e to the +minus a + k t + + align:start position:0% +minus a + k t + + + align:start position:0% +minus a + k t +okay and I can expand out multiply out e + + align:start position:0% +okay and I can expand out multiply out e + + + align:start position:0% +okay and I can expand out multiply out e +to the a + + align:start position:0% + + + + align:start position:0% + +t and when the dust + + align:start position:0% +t and when the dust + + + align:start position:0% +t and when the dust +settles we have e to the A T + + align:start position:0% +settles we have e to the A T + + + align:start position:0% +settles we have e to the A T +minus E to the minus + + align:start position:0% + + + + align:start position:0% + +KT okay so this is just the uh the + + align:start position:0% +KT okay so this is just the uh the + + + align:start position:0% +KT okay so this is just the uh the +computation of the convolution e to the + + align:start position:0% +computation of the convolution e to the + + + align:start position:0% +computation of the convolution e to the +minus KT and e to the a t so note now if + + align:start position:0% +minus KT and e to the a t so note now if + + + align:start position:0% +minus KT and e to the a t so note now if +if for example K were to equal negative + + align:start position:0% +if for example K were to equal negative + + + align:start position:0% +if for example K were to equal negative +a we would have zero in the denominator + + align:start position:0% +a we would have zero in the denominator + + + align:start position:0% +a we would have zero in the denominator +and zero in the numerator so one way to + + align:start position:0% +and zero in the numerator so one way to + + + align:start position:0% +and zero in the numerator so one way to +compute the Special K when case when K + + align:start position:0% +compute the Special K when case when K + + + align:start position:0% +compute the Special K when case when K +is equal to negative a is to use lel's + + align:start position:0% +is equal to negative a is to use lel's + + + align:start position:0% +is equal to negative a is to use lel's +Rule and differentiate the top and the + + align:start position:0% +Rule and differentiate the top and the + + + align:start position:0% +Rule and differentiate the top and the +bottom uh for example with respect to + + align:start position:0% + + + + align:start position:0% + +K another alternative way of computing + + align:start position:0% +K another alternative way of computing + + + align:start position:0% +K another alternative way of computing +uh the special case when uh a is equal + + align:start position:0% +uh the special case when uh a is equal + + + align:start position:0% +uh the special case when uh a is equal +to negative k is just to plug in e to + + align:start position:0% +to negative k is just to plug in e to + + + align:start position:0% +to negative k is just to plug in e to +the uh e to the K and then just work out + + align:start position:0% +the uh e to the K and then just work out + + + align:start position:0% +the uh e to the K and then just work out +this integral and you'll obtain a + + align:start position:0% +this integral and you'll obtain a + + + align:start position:0% +this integral and you'll obtain a +different + + align:start position:0% +different + + + align:start position:0% +different +answer okay and now lastly for Part B + + align:start position:0% +answer okay and now lastly for Part B + + + align:start position:0% +answer okay and now lastly for Part B +we're interested in the differential + + align:start position:0% +we're interested in the differential + + + align:start position:0% +we're interested in the differential +equation x dot plus + + align:start position:0% +equation x dot plus + + + align:start position:0% +equation x dot plus +KX equal e to a T and we're interested + + align:start position:0% +KX equal e to a T and we're interested + + + align:start position:0% +KX equal e to a T and we're interested +in finding uh the particular solution + + align:start position:0% +in finding uh the particular solution + + + align:start position:0% +in finding uh the particular solution +that has rest initial + + align:start position:0% +that has rest initial + + + align:start position:0% +that has rest initial +conditions so for example X of 0 is + + align:start position:0% +conditions so for example X of 0 is + + + align:start position:0% +conditions so for example X of 0 is +equal a + + align:start position:0% + + + + align:start position:0% + +zero and uh we want to use Green's + + align:start position:0% +zero and uh we want to use Green's + + + align:start position:0% +zero and uh we want to use Green's +formula so just recall that uh there's + + align:start position:0% +formula so just recall that uh there's + + + align:start position:0% +formula so just recall that uh there's +the impulse response + + align:start position:0% +the impulse response + + + align:start position:0% +the impulse response +formula or the weight function + + align:start position:0% + + + + align:start position:0% + +W which solves the same differential + + align:start position:0% +W which solves the same differential + + + align:start position:0% +W which solves the same differential +equation but with the Delta function on + + align:start position:0% +equation but with the Delta function on + + + align:start position:0% +equation but with the Delta function on +the right hand + + align:start position:0% +the right hand + + + align:start position:0% +the right hand +side and + + align:start position:0% +side and + + + align:start position:0% +side and +W in this case + + align:start position:0% +W in this case + + + align:start position:0% +W in this case +as we've seen in lecture is actually e + + align:start position:0% +as we've seen in lecture is actually e + + + align:start position:0% +as we've seen in lecture is actually e +uh to the negative + + align:start position:0% +uh to the negative + + + align:start position:0% +uh to the negative +KT when T is bigger than zero and it's + + align:start position:0% +KT when T is bigger than zero and it's + + + align:start position:0% +KT when T is bigger than zero and it's +zero when T is less than + + align:start position:0% + + + + align:start position:0% + +zero so notice how e minus KT is exactly + + align:start position:0% +zero so notice how e minus KT is exactly + + + align:start position:0% +zero so notice how e minus KT is exactly +the function that we convolved in part + + align:start position:0% +the function that we convolved in part + + + align:start position:0% +the function that we convolved in part +a uh specifically we convolved it with e + + align:start position:0% +a uh specifically we convolved it with e + + + align:start position:0% +a uh specifically we convolved it with e +to + + align:start position:0% +to + + + align:start position:0% +to +a so for example Green's formula says + + align:start position:0% +a so for example Green's formula says + + + align:start position:0% +a so for example Green's formula says +that the particular solution that has + + align:start position:0% +that the particular solution that has + + + align:start position:0% +that the particular solution that has +rest initial condition + + align:start position:0% +rest initial condition + + + align:start position:0% +rest initial condition +is going to be the weight + + align:start position:0% +is going to be the weight + + + align:start position:0% +is going to be the weight +function convolved with the right hand + + align:start position:0% +function convolved with the right hand + + + align:start position:0% +function convolved with the right hand +side of the differential + + align:start position:0% +side of the differential + + + align:start position:0% +side of the differential +equation e to the a + + align:start position:0% +equation e to the a + + + align:start position:0% +equation e to the a +t in this case on the domain of + + align:start position:0% +t in this case on the domain of + + + align:start position:0% +t in this case on the domain of +integration for the convolution W is + + align:start position:0% +integration for the convolution W is + + + align:start position:0% +integration for the convolution W is +just e the minus + + align:start position:0% + + + + align:start position:0% + +KT so we have e minus KT involved with E + + align:start position:0% +KT so we have e minus KT involved with E + + + align:start position:0% +KT so we have e minus KT involved with E +the a t so Green's formula gives us uh + + align:start position:0% +the a t so Green's formula gives us uh + + + align:start position:0% +the a t so Green's formula gives us uh +the equation for the solution to this + + align:start position:0% +the equation for the solution to this + + + align:start position:0% +the equation for the solution to this +differential equation which has rest + + align:start position:0% +differential equation which has rest + + + align:start position:0% +differential equation which has rest +initial + + align:start position:0% +initial + + + align:start position:0% +initial +conditions and specifically we've + + align:start position:0% +conditions and specifically we've + + + align:start position:0% +conditions and specifically we've +already worked this out from part A so I + + align:start position:0% +already worked this out from part A so I + + + align:start position:0% +already worked this out from part A so I +can just write down what the answer + + align:start position:0% +can just write down what the answer + + + align:start position:0% +can just write down what the answer +is it's 1 over a plus + + align:start position:0% + + + + align:start position:0% + +k e to the A T minus eus + + align:start position:0% + + + + align:start position:0% + +KT and just as a quick check to make + + align:start position:0% +KT and just as a quick check to make + + + align:start position:0% +KT and just as a quick check to make +sure that we've done everything + + align:start position:0% +sure that we've done everything + + + align:start position:0% +sure that we've done everything +correctly we can plug in t equals 0 and + + align:start position:0% +correctly we can plug in t equals 0 and + + + align:start position:0% +correctly we can plug in t equals 0 and +when T equals 0 we have 1us 1 which + + align:start position:0% +when T equals 0 we have 1us 1 which + + + align:start position:0% +when T equals 0 we have 1us 1 which +gives us Z so indeed this x is the + + align:start position:0% +gives us Z so indeed this x is the + + + align:start position:0% +gives us Z so indeed this x is the +solution to this differential equation + + align:start position:0% +solution to this differential equation + + + align:start position:0% +solution to this differential equation +which has rest initial + + align:start position:0% +which has rest initial + + + align:start position:0% +which has rest initial +conditions okay so I'd uh just like to + + align:start position:0% +conditions okay so I'd uh just like to + + + align:start position:0% +conditions okay so I'd uh just like to +conclude this problem uh quick recap uh + + align:start position:0% +conclude this problem uh quick recap uh + + + align:start position:0% +conclude this problem uh quick recap uh +we worked out several convolutions and + + align:start position:0% +we worked out several convolutions and + + + align:start position:0% +we worked out several convolutions and +uh specifically we were able to use + + align:start position:0% +uh specifically we were able to use + + + align:start position:0% +uh specifically we were able to use +green + + align:start position:0% +green + + + align:start position:0% +green +formula uh in addition to the + + align:start position:0% +formula uh in addition to the + + + align:start position:0% +formula uh in addition to the +convolution that we worked out to + + align:start position:0% +convolution that we worked out to + + + align:start position:0% +convolution that we worked out to +compute the solution with rest initial + + align:start position:0% +compute the solution with rest initial + + + align:start position:0% +compute the solution with rest initial +conditions to an OD uh moreover Green's + + align:start position:0% +conditions to an OD uh moreover Green's + + + align:start position:0% +conditions to an OD uh moreover Green's +function is very useful because notice + + align:start position:0% +function is very useful because notice + + + align:start position:0% +function is very useful because notice +how we could have computed the + + align:start position:0% +how we could have computed the + + + align:start position:0% +how we could have computed the +convolution for any right- hand side + + align:start position:0% +convolution for any right- hand side + + + align:start position:0% +convolution for any right- hand side +function here so uh in some sense we're + + align:start position:0% +function here so uh in some sense we're + + + align:start position:0% +function here so uh in some sense we're +able to generalize and find solutions to + + align:start position:0% +able to generalize and find solutions to + + + align:start position:0% +able to generalize and find solutions to +differential equations which have + + align:start position:0% +differential equations which have + + + align:start position:0% +differential equations which have +arbitrary right- hand side forcings not + + align:start position:0% +arbitrary right- hand side forcings not + + + align:start position:0% +arbitrary right- hand side forcings not +just signs and cosiness periodic + + align:start position:0% +just signs and cosiness periodic + + + align:start position:0% +just signs and cosiness periodic +functions or other simple functions + + align:start position:0% +functions or other simple functions + + + align:start position:0% +functions or other simple functions +which we've been looking at in the + + align:start position:0% +which we've been looking at in the + + + align:start position:0% +which we've been looking at in the +past so I'd like to conclude here and + + align:start position:0% +past so I'd like to conclude here and + + + align:start position:0% +past so I'd like to conclude here and +I'll see you next time \ No newline at end of file diff --git a/ITE9w9wKVKU.txt b/ITE9w9wKVKU.txt new file mode 100644 index 0000000000000000000000000000000000000000..a558b124cd6e008020943b53f4206be6f9f6ae75 --- /dev/null +++ b/ITE9w9wKVKU.txt @@ -0,0 +1,8531 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +professor of urban studies and planning + + align:start position:0% +professor of urban studies and planning + + + align:start position:0% +professor of urban studies and planning +at MIT and this is another installment + + align:start position:0% +at MIT and this is another installment + + + align:start position:0% +at MIT and this is another installment +of my lecture series on Urban Energy + + align:start position:0% +of my lecture series on Urban Energy + + + align:start position:0% +of my lecture series on Urban Energy +Systems and policies + + align:start position:0% +Systems and policies + + + align:start position:0% +Systems and policies +today we're going to talk about + + align:start position:0% +today we're going to talk about + + + align:start position:0% +today we're going to talk about +renewable energy and we've been talking + + align:start position:0% +renewable energy and we've been talking + + + align:start position:0% +renewable energy and we've been talking +in this plots about consumption how we + + align:start position:0% +in this plots about consumption how we + + + align:start position:0% +in this plots about consumption how we +consume energy in our personal + + align:start position:0% +consume energy in our personal + + + align:start position:0% +consume energy in our personal +transportation and our buildings and our + + align:start position:0% +transportation and our buildings and our + + + align:start position:0% +transportation and our buildings and our +consumption of material Goods quite + + align:start position:0% +consumption of material Goods quite + + + align:start position:0% +consumption of material Goods quite +often produced by industrial + + align:start position:0% +often produced by industrial + + + align:start position:0% +often produced by industrial +manufacturing processes and I've + + align:start position:0% +manufacturing processes and I've + + + align:start position:0% +manufacturing processes and I've +emphasized in the class that we need to + + align:start position:0% +emphasized in the class that we need to + + + align:start position:0% +emphasized in the class that we need to +make all those uses more efficient in + + align:start position:0% +make all those uses more efficient in + + + align:start position:0% +make all those uses more efficient in +order for us to help decarbonate cities + + align:start position:0% +order for us to help decarbonate cities + + + align:start position:0% +order for us to help decarbonate cities +but now it's time for us to turn to talk + + align:start position:0% +but now it's time for us to turn to talk + + + align:start position:0% +but now it's time for us to turn to talk +about renewable energy the fundamental + + align:start position:0% +about renewable energy the fundamental + + + align:start position:0% +about renewable energy the fundamental +building blocks now enabled cities to + + align:start position:0% +building blocks now enabled cities to + + + align:start position:0% +building blocks now enabled cities to +transition from their current energy + + align:start position:0% +transition from their current energy + + + align:start position:0% +transition from their current energy +sources which mostly depend on fossil + + align:start position:0% +sources which mostly depend on fossil + + + align:start position:0% +sources which mostly depend on fossil +fuels to renewable energy energy sources + + align:start position:0% +fuels to renewable energy energy sources + + + align:start position:0% +fuels to renewable energy energy sources +that will help cities decarbonize and + + align:start position:0% +that will help cities decarbonize and + + + align:start position:0% +that will help cities decarbonize and +avoid the worst consequences of climate + + align:start position:0% +avoid the worst consequences of climate + + + align:start position:0% +avoid the worst consequences of climate +change + + align:start position:0% +change + + + align:start position:0% +change +so today in the first part I'll talk + + align:start position:0% +so today in the first part I'll talk + + + align:start position:0% +so today in the first part I'll talk +about wind energy + + align:start position:0% +about wind energy + + + align:start position:0% +about wind energy +the materials for today if you have the + + align:start position:0% +the materials for today if you have the + + + align:start position:0% +the materials for today if you have the +PDF or hard copies you can click on + + align:start position:0% +PDF or hard copies you can click on + + + align:start position:0% +PDF or hard copies you can click on +these pink links and they'll take you to + + align:start position:0% +these pink links and they'll take you to + + + align:start position:0% +these pink links and they'll take you to +the various resources these are the + + align:start position:0% +the various resources these are the + + + align:start position:0% +the various resources these are the +materials will be this we'll be + + align:start position:0% +materials will be this we'll be + + + align:start position:0% +materials will be this we'll be +discussing today + + align:start position:0% +discussing today + + + align:start position:0% +discussing today +and just to refresh our memory where we + + align:start position:0% +and just to refresh our memory where we + + + align:start position:0% +and just to refresh our memory where we +are uh these are again the + + align:start position:0% +are uh these are again the + + + align:start position:0% +are uh these are again the +decarborization pathways from the + + align:start position:0% +decarborization pathways from the + + + align:start position:0% +decarborization pathways from the +Williams NL 2021 paper this is the 100 + + align:start position:0% +Williams NL 2021 paper this is the 100 + + + align:start position:0% +Williams NL 2021 paper this is the 100 +renewable energy scenario so on the left + + align:start position:0% +renewable energy scenario so on the left + + + align:start position:0% +renewable energy scenario so on the left +hand side of the Sankey diagram you can + + align:start position:0% +hand side of the Sankey diagram you can + + + align:start position:0% +hand side of the Sankey diagram you can +see that all of our primary energy + + align:start position:0% +see that all of our primary energy + + + align:start position:0% +see that all of our primary energy +sources are essentially uh decarbonized + + align:start position:0% +sources are essentially uh decarbonized + + + align:start position:0% +sources are essentially uh decarbonized +renewable energy sources solar wind and + + align:start position:0% +renewable energy sources solar wind and + + + align:start position:0% +renewable energy sources solar wind and +biomass being the three largest sources + + align:start position:0% +biomass being the three largest sources + + + align:start position:0% +biomass being the three largest sources +of energy + + align:start position:0% +of energy + + + align:start position:0% +of energy +and what I want to emphasize in this + + align:start position:0% +and what I want to emphasize in this + + + align:start position:0% +and what I want to emphasize in this +class is that we're going to over the + + align:start position:0% +class is that we're going to over the + + + align:start position:0% +class is that we're going to over the +next few classes is we're going to talk + + align:start position:0% +next few classes is we're going to talk + + + align:start position:0% +next few classes is we're going to talk +about your renewable toolbox like high + + align:start position:0% +about your renewable toolbox like high + + + align:start position:0% +about your renewable toolbox like high +defines sustainable energy or a + + align:start position:0% +defines sustainable energy or a + + + align:start position:0% +defines sustainable energy or a +sustainable production of energy as + + align:start position:0% +sustainable production of energy as + + + align:start position:0% +sustainable production of energy as +categories of wind + + align:start position:0% +categories of wind + + + align:start position:0% +categories of wind +solar hydropower wave power high power + + align:start position:0% +solar hydropower wave power high power + + + align:start position:0% +solar hydropower wave power high power +geothermal power and Makai gives nuclear + + align:start position:0% +geothermal power and Makai gives nuclear + + + align:start position:0% +geothermal power and Makai gives nuclear +a question mark because it's not clear + + align:start position:0% +a question mark because it's not clear + + + align:start position:0% +a question mark because it's not clear +whether or not it's not clear to look + + align:start position:0% +whether or not it's not clear to look + + + align:start position:0% +whether or not it's not clear to look +high and still to me what their nuclear + + align:start position:0% +high and still to me what their nuclear + + + align:start position:0% +high and still to me what their nuclear +power counts as sustainable + + align:start position:0% +power counts as sustainable + + + align:start position:0% +power counts as sustainable +but what I wanted to set up a renewable + + align:start position:0% +but what I wanted to set up a renewable + + + align:start position:0% +but what I wanted to set up a renewable +toolbox and we're going to develop this + + align:start position:0% +toolbox and we're going to develop this + + + align:start position:0% +toolbox and we're going to develop this +theme in the next few lectures is that + + align:start position:0% +theme in the next few lectures is that + + + align:start position:0% +theme in the next few lectures is that +it has becoming decently cheap + + align:start position:0% +it has becoming decently cheap + + + align:start position:0% +it has becoming decently cheap +increasingly clean but these fundamental + + align:start position:0% +increasingly clean but these fundamental + + + align:start position:0% +increasingly clean but these fundamental +Technologies require transitioning our + + align:start position:0% +Technologies require transitioning our + + + align:start position:0% +Technologies require transitioning our +energy system and how it works because + + align:start position:0% +energy system and how it works because + + + align:start position:0% +energy system and how it works because +they work in different ways in our + + align:start position:0% +they work in different ways in our + + + align:start position:0% +they work in different ways in our +existing fossil fuel resources + + align:start position:0% +existing fossil fuel resources + + + align:start position:0% +existing fossil fuel resources +and so just to kind of give a definition + + align:start position:0% +and so just to kind of give a definition + + + align:start position:0% +and so just to kind of give a definition +of renewal resources why we are focused + + align:start position:0% +of renewal resources why we are focused + + + align:start position:0% +of renewal resources why we are focused +on particular Technologies there are + + align:start position:0% +on particular Technologies there are + + + align:start position:0% +on particular Technologies there are +technologies that drive Energy natural + + align:start position:0% +technologies that drive Energy natural + + + align:start position:0% +technologies that drive Energy natural +processes they can be regenerative over + + align:start position:0% +processes they can be regenerative over + + + align:start position:0% +processes they can be regenerative over +short periods of time and they will not + + align:start position:0% +short periods of time and they will not + + + align:start position:0% +short periods of time and they will not +be depleted + + align:start position:0% +be depleted + + + align:start position:0% +be depleted +we can talk about whether or not + + align:start position:0% +we can talk about whether or not + + + align:start position:0% +we can talk about whether or not +Renewables are defined as clean Net Zero + + align:start position:0% +Renewables are defined as clean Net Zero + + + align:start position:0% +Renewables are defined as clean Net Zero +or carbon free all these definitions or + + align:start position:0% +or carbon free all these definitions or + + + align:start position:0% +or carbon free all these definitions or +these uh various descriptors have + + align:start position:0% +these uh various descriptors have + + + align:start position:0% +these uh various descriptors have +different uh slightly different meanings + + align:start position:0% +different uh slightly different meanings + + + align:start position:0% +different uh slightly different meanings +and of course I want to emphasize Energy + + align:start position:0% +and of course I want to emphasize Energy + + + align:start position:0% +and of course I want to emphasize Energy +Efficiency is also necessary for us to + + align:start position:0% +Efficiency is also necessary for us to + + + align:start position:0% +Efficiency is also necessary for us to +achieve decarbonization the 100 + + align:start position:0% +achieve decarbonization the 100 + + + align:start position:0% +achieve decarbonization the 100 +renewable scenario I showed you in the + + align:start position:0% +renewable scenario I showed you in the + + + align:start position:0% +renewable scenario I showed you in the +last slide and for the Williams NL + + align:start position:0% +last slide and for the Williams NL + + + align:start position:0% +last slide and for the Williams NL +papers and many most of the + + align:start position:0% +papers and many most of the + + + align:start position:0% +papers and many most of the +decomposition studies all emphasize the + + align:start position:0% +decomposition studies all emphasize the + + + align:start position:0% +decomposition studies all emphasize the +fact that we can't build renewable + + align:start position:0% +fact that we can't build renewable + + + align:start position:0% +fact that we can't build renewable +resources as fast as we need to to meet + + align:start position:0% +resources as fast as we need to to meet + + + align:start position:0% +resources as fast as we need to to meet +our mid-century goal so it's going to be + + align:start position:0% +our mid-century goal so it's going to be + + + align:start position:0% +our mid-century goal so it's going to be +necessary to use Energy Efficiency and + + align:start position:0% +necessary to use Energy Efficiency and + + + align:start position:0% +necessary to use Energy Efficiency and +that can be the Technologies products + + align:start position:0% +that can be the Technologies products + + + align:start position:0% +that can be the Technologies products +services or changes in behaviors or + + align:start position:0% +services or changes in behaviors or + + + align:start position:0% +services or changes in behaviors or +expectations and reduce the energy + + align:start position:0% +expectations and reduce the energy + + + align:start position:0% +expectations and reduce the energy +required for certain processes or tasks + + align:start position:0% +required for certain processes or tasks + + + align:start position:0% +required for certain processes or tasks +or services and we also talked about + + align:start position:0% +or services and we also talked about + + + align:start position:0% +or services and we also talked about +about that a few lectures ago + + align:start position:0% +about that a few lectures ago + + + align:start position:0% +about that a few lectures ago +and the other thing I want to emphasize + + align:start position:0% +and the other thing I want to emphasize + + + align:start position:0% +and the other thing I want to emphasize +about your renewal toolbox is that it + + align:start position:0% +about your renewal toolbox is that it + + + align:start position:0% +about your renewal toolbox is that it +has different limitations we have to + + align:start position:0% +has different limitations we have to + + + align:start position:0% +has different limitations we have to +think about some key factors or key + + align:start position:0% +think about some key factors or key + + + align:start position:0% +think about some key factors or key +categories of problems to solve + + align:start position:0% +categories of problems to solve + + + align:start position:0% +categories of problems to solve +first there's the total potential of + + align:start position:0% +first there's the total potential of + + + align:start position:0% +first there's the total potential of +renewable energy that we can achieve in + + align:start position:0% +renewable energy that we can achieve in + + + align:start position:0% +renewable energy that we can achieve in +a meaningful period of time + + align:start position:0% +a meaningful period of time + + + align:start position:0% +a meaningful period of time +second as you may have heard many + + align:start position:0% +second as you may have heard many + + + align:start position:0% +second as you may have heard many +renewable Technologies may be + + align:start position:0% +renewable Technologies may be + + + align:start position:0% +renewable Technologies may be +intermittent in terms of how they derive + + align:start position:0% +intermittent in terms of how they derive + + + align:start position:0% +intermittent in terms of how they derive +energy from natural processes and + + align:start position:0% +energy from natural processes and + + + align:start position:0% +energy from natural processes and +something I've emphasized in this class + + align:start position:0% +something I've emphasized in this class + + + align:start position:0% +something I've emphasized in this class +and I think is particularly relevant to + + align:start position:0% +and I think is particularly relevant to + + + align:start position:0% +and I think is particularly relevant to +cities and land use is how much land use + + align:start position:0% +cities and land use is how much land use + + + align:start position:0% +cities and land use is how much land use +or how much land TIG is required to + + align:start position:0% +or how much land TIG is required to + + + align:start position:0% +or how much land TIG is required to +build renewable resources renewable + + align:start position:0% +build renewable resources renewable + + + align:start position:0% +build renewable resources renewable +resources are quite often less energy + + align:start position:0% +resources are quite often less energy + + + align:start position:0% +resources are quite often less energy +dense than a fossil fuel energy systems + + align:start position:0% +dense than a fossil fuel energy systems + + + align:start position:0% +dense than a fossil fuel energy systems +but just to give you a sense of kind of + + align:start position:0% +but just to give you a sense of kind of + + + align:start position:0% +but just to give you a sense of kind of +the intermittency or what the kind of + + align:start position:0% +the intermittency or what the kind of + + + align:start position:0% +the intermittency or what the kind of +sources of energy for wind and solar + + align:start position:0% +sources of energy for wind and solar + + + align:start position:0% +sources of energy for wind and solar +look like there's a few kind of fun + + align:start position:0% +look like there's a few kind of fun + + + align:start position:0% +look like there's a few kind of fun +fun visualizations I'll click on here in + + align:start position:0% +fun visualizations I'll click on here in + + + align:start position:0% +fun visualizations I'll click on here in +a moment + + align:start position:0% +a moment + + + align:start position:0% +a moment +if we look at the wind right now across + + align:start position:0% +if we look at the wind right now across + + + align:start position:0% +if we look at the wind right now across +the United States that first link takes + + align:start position:0% +the United States that first link takes + + + align:start position:0% +the United States that first link takes +us to this wind map that you can see + + align:start position:0% +us to this wind map that you can see + + + align:start position:0% +us to this wind map that you can see +here you can see that the wind has a + + align:start position:0% +here you can see that the wind has a + + + align:start position:0% +here you can see that the wind has a +directionality it's concentrated in some + + align:start position:0% +directionality it's concentrated in some + + + align:start position:0% +directionality it's concentrated in some +places quite clearly blowing in the + + align:start position:0% +places quite clearly blowing in the + + + align:start position:0% +places quite clearly blowing in the +Mountain West and the Midwest and Texas + + align:start position:0% +Mountain West and the Midwest and Texas + + + align:start position:0% +Mountain West and the Midwest and Texas +much more than it is here on the East + + align:start position:0% +much more than it is here on the East + + + align:start position:0% +much more than it is here on the East +Coast where we I'm recording this video + + align:start position:0% +Coast where we I'm recording this video + + + align:start position:0% +Coast where we I'm recording this video +if we look at the global map of wind you + + align:start position:0% +if we look at the global map of wind you + + + align:start position:0% +if we look at the global map of wind you +can also see something something very + + align:start position:0% +can also see something something very + + + align:start position:0% +can also see something something very +different you can see that the wind is + + align:start position:0% +different you can see that the wind is + + + align:start position:0% +different you can see that the wind is +much stronger over the oceans than it is + + align:start position:0% +much stronger over the oceans than it is + + + align:start position:0% +much stronger over the oceans than it is +over the land + + align:start position:0% +over the land + + + align:start position:0% +over the land +uh this is a pretty neat little + + align:start position:0% +uh this is a pretty neat little + + + align:start position:0% +uh this is a pretty neat little +visualization you can actually see any + + align:start position:0% +visualization you can actually see any + + + align:start position:0% +visualization you can actually see any +part of the world and see where the wind + + align:start position:0% +part of the world and see where the wind + + + align:start position:0% +part of the world and see where the wind +is and of course these little vectors + + align:start position:0% +is and of course these little vectors + + + align:start position:0% +is and of course these little vectors +and these kind of fields of vectors show + + align:start position:0% +and these kind of fields of vectors show + + + align:start position:0% +and these kind of fields of vectors show +you that uh there may be a storm off of + + align:start position:0% +you that uh there may be a storm off of + + + align:start position:0% +you that uh there may be a storm off of +I think Mexico here there may be some + + align:start position:0% +I think Mexico here there may be some + + + align:start position:0% +I think Mexico here there may be some +very strong winds in the upper North + + align:start position:0% +very strong winds in the upper North + + + align:start position:0% +very strong winds in the upper North +Atlantic but you can see in almost all + + align:start position:0% +Atlantic but you can see in almost all + + + align:start position:0% +Atlantic but you can see in almost all +the cases that the wind is much stronger + + align:start position:0% +the cases that the wind is much stronger + + + align:start position:0% +the cases that the wind is much stronger +offshore than it is onshore and that'll + + align:start position:0% +offshore than it is onshore and that'll + + + align:start position:0% +offshore than it is onshore and that'll +be a key theme we'll talk about today + + align:start position:0% +be a key theme we'll talk about today + + + align:start position:0% +be a key theme we'll talk about today +so just going back to our slides on wind + + align:start position:0% + + + + align:start position:0% + +again to emphasize that your renewal + + align:start position:0% +again to emphasize that your renewal + + + align:start position:0% +again to emphasize that your renewal +toolbox is going to require deploying + + align:start position:0% +toolbox is going to require deploying + + + align:start position:0% +toolbox is going to require deploying +these at scale that's going to require + + align:start position:0% +these at scale that's going to require + + + align:start position:0% +these at scale that's going to require +us to essentially build a new Energy + + align:start position:0% +us to essentially build a new Energy + + + align:start position:0% +us to essentially build a new Energy +System to avoid climate change and so + + align:start position:0% +System to avoid climate change and so + + + align:start position:0% +System to avoid climate change and so +you just want to focus on the building + + align:start position:0% +you just want to focus on the building + + + align:start position:0% +you just want to focus on the building +block for a second and what the + + align:start position:0% +block for a second and what the + + + align:start position:0% +block for a second and what the +challenge is uh the first building block + + align:start position:0% +challenge is uh the first building block + + + align:start position:0% +challenge is uh the first building block +is going to be a solar + + align:start position:0% +is going to be a solar + + + align:start position:0% +is going to be a solar +I'll talk about how a Solar Technologies + + align:start position:0% +I'll talk about how a Solar Technologies + + + align:start position:0% +I'll talk about how a Solar Technologies +have drastically cheaper in the next + + align:start position:0% +have drastically cheaper in the next + + + align:start position:0% +have drastically cheaper in the next +lecture but we have to build + + align:start position:0% +lecture but we have to build + + + align:start position:0% +lecture but we have to build +approximately 47 times more solar in the + + align:start position:0% +approximately 47 times more solar in the + + + align:start position:0% +approximately 47 times more solar in the +United States to achieve our mid-century + + align:start position:0% +United States to achieve our mid-century + + + align:start position:0% +United States to achieve our mid-century +goals wind as another building block + + align:start position:0% +goals wind as another building block + + + align:start position:0% +goals wind as another building block +that has been very successful probably + + align:start position:0% +that has been very successful probably + + + align:start position:0% +that has been very successful probably +our highest amount of capacity of + + align:start position:0% +our highest amount of capacity of + + + align:start position:0% +our highest amount of capacity of +renewable energy coming from wind right + + align:start position:0% +renewable energy coming from wind right + + + align:start position:0% +renewable energy coming from wind right +now we still have to actually increase + + align:start position:0% +now we still have to actually increase + + + align:start position:0% +now we still have to actually increase +the amount we've built by 28 times over + + align:start position:0% +the amount we've built by 28 times over + + + align:start position:0% +the amount we've built by 28 times over +what we've built over the last 40 years + + align:start position:0% +what we've built over the last 40 years + + + align:start position:0% +what we've built over the last 40 years +and storage geothermal analog + + align:start position:0% +and storage geothermal analog + + + align:start position:0% +and storage geothermal analog +electrolysis that can be used to create + + align:start position:0% +electrolysis that can be used to create + + + align:start position:0% +electrolysis that can be used to create +hydrogen from renewable resources those + + align:start position:0% +hydrogen from renewable resources those + + + align:start position:0% +hydrogen from renewable resources those +are fundamentally building blocks that + + align:start position:0% +are fundamentally building blocks that + + + align:start position:0% +are fundamentally building blocks that +are going to be part of the annual + + align:start position:0% +are going to be part of the annual + + + align:start position:0% +are going to be part of the annual +toolbox but I want to emphasize this + + align:start position:0% +toolbox but I want to emphasize this + + + align:start position:0% +toolbox but I want to emphasize this +toolbox is probably the toolbox you'll + + align:start position:0% +toolbox is probably the toolbox you'll + + + align:start position:0% +toolbox is probably the toolbox you'll +be using for much of your careers and to + + align:start position:0% +be using for much of your careers and to + + + align:start position:0% +be using for much of your careers and to +your credit or to your advantage all + + align:start position:0% +your credit or to your advantage all + + + align:start position:0% +your credit or to your advantage all +these building blocks have gotten + + align:start position:0% +these building blocks have gotten + + + align:start position:0% +these building blocks have gotten +increasingly cheap over time will + + align:start position:0% +increasingly cheap over time will + + + align:start position:0% +increasingly cheap over time will +probably get cheaper over time + + align:start position:0% +probably get cheaper over time + + + align:start position:0% +probably get cheaper over time +all you have to figure out in your + + align:start position:0% +all you have to figure out in your + + + align:start position:0% +all you have to figure out in your +careers is + + align:start position:0% +careers is + + + align:start position:0% +careers is +um give you a to-do list for your + + align:start position:0% +um give you a to-do list for your + + + align:start position:0% +um give you a to-do list for your +careers all you have to do is figure out + + align:start position:0% +careers all you have to do is figure out + + + align:start position:0% +careers all you have to do is figure out +how to finance these new technologies + + align:start position:0% +how to finance these new technologies + + + align:start position:0% +how to finance these new technologies +which sometimes have our higher upfront + + align:start position:0% +which sometimes have our higher upfront + + + align:start position:0% +which sometimes have our higher upfront +costs + + align:start position:0% +costs + + + align:start position:0% +costs +all you should do is figure out how to + + align:start position:0% +all you should do is figure out how to + + + align:start position:0% +all you should do is figure out how to +install the capacity the 47 times more + + align:start position:0% +install the capacity the 47 times more + + + align:start position:0% +install the capacity the 47 times more +solar 28 times more win to generate + + align:start position:0% +solar 28 times more win to generate + + + align:start position:0% +solar 28 times more win to generate +electricity or energy + + align:start position:0% +electricity or energy + + + align:start position:0% +electricity or energy +you have to figure out how to transmit + + align:start position:0% +you have to figure out how to transmit + + + align:start position:0% +you have to figure out how to transmit +this power across by the places that is + + align:start position:0% +this power across by the places that is + + + align:start position:0% +this power across by the places that is +generated to the places that it's needed + + align:start position:0% +generated to the places that it's needed + + + align:start position:0% +generated to the places that it's needed +we'll have to figure out how to + + align:start position:0% +we'll have to figure out how to + + + align:start position:0% +we'll have to figure out how to +distribute this power within cities I'll + + align:start position:0% +distribute this power within cities I'll + + + align:start position:0% +distribute this power within cities I'll +have to figure out how to balance this + + align:start position:0% +have to figure out how to balance this + + + align:start position:0% +have to figure out how to balance this +power across the grid because + + align:start position:0% +power across the grid because + + + align:start position:0% +power across the grid because +electricity cannot very easily be stored + + align:start position:0% +electricity cannot very easily be stored + + + align:start position:0% +electricity cannot very easily be stored +though we'll talk about storage you have + + align:start position:0% +though we'll talk about storage you have + + + align:start position:0% +though we'll talk about storage you have +to figure out how to balance the system + + align:start position:0% +to figure out how to balance the system + + + align:start position:0% +to figure out how to balance the system +so that when you're generating power in + + align:start position:0% +so that when you're generating power in + + + align:start position:0% +so that when you're generating power in +one part of the continental US like you + + align:start position:0% +one part of the continental US like you + + + align:start position:0% +one part of the continental US like you +saw the wind blowing them out in the + + align:start position:0% +saw the wind blowing them out in the + + + align:start position:0% +saw the wind blowing them out in the +west it can be consumed elsewhere like + + align:start position:0% +west it can be consumed elsewhere like + + + align:start position:0% +west it can be consumed elsewhere like +on the West Coast + + align:start position:0% +on the West Coast + + + align:start position:0% +on the West Coast +you have to figure out how to make this + + align:start position:0% +you have to figure out how to make this + + + align:start position:0% +you have to figure out how to make this +grid reliable you have to figure out how + + align:start position:0% +grid reliable you have to figure out how + + + align:start position:0% +grid reliable you have to figure out how +to make this grid resilient in the face + + align:start position:0% +to make this grid resilient in the face + + + align:start position:0% +to make this grid resilient in the face +of increasing climate changes + + align:start position:0% +of increasing climate changes + + + align:start position:0% +of increasing climate changes +and of course you have to cite all these + + align:start position:0% +and of course you have to cite all these + + + align:start position:0% +and of course you have to cite all these +resources and all these transformation + + align:start position:0% +resources and all these transformation + + + align:start position:0% +resources and all these transformation +lines so again your renewable toolbox + + align:start position:0% +lines so again your renewable toolbox + + + align:start position:0% +lines so again your renewable toolbox +has fundamentally really interesting + + align:start position:0% +has fundamentally really interesting + + + align:start position:0% +has fundamentally really interesting +really increasingly cheap and cost + + align:start position:0% +really increasingly cheap and cost + + + align:start position:0% +really increasingly cheap and cost +effective building blocks on the + + align:start position:0% +effective building blocks on the + + + align:start position:0% +effective building blocks on the +left-hand side this is your to-do list + + align:start position:0% +left-hand side this is your to-do list + + + align:start position:0% +left-hand side this is your to-do list +to build a new Energy System on the + + align:start position:0% +to build a new Energy System on the + + + align:start position:0% +to build a new Energy System on the +right hand side + + align:start position:0% +right hand side + + + align:start position:0% +right hand side +so the agenda for our next few classes + + align:start position:0% +so the agenda for our next few classes + + + align:start position:0% +so the agenda for our next few classes +is going to emphasize a series of + + align:start position:0% +is going to emphasize a series of + + + align:start position:0% +is going to emphasize a series of +different Technologies and I'll try to + + align:start position:0% +different Technologies and I'll try to + + + align:start position:0% +different Technologies and I'll try to +teach you a series of different concepts + + align:start position:0% +teach you a series of different concepts + + + align:start position:0% +teach you a series of different concepts +that are useful to think about the + + align:start position:0% +that are useful to think about the + + + align:start position:0% +that are useful to think about the +nature of those Technologies so today + + align:start position:0% +nature of those Technologies so today + + + align:start position:0% +nature of those Technologies so today +we'll talk about win Basics and we'll + + align:start position:0% +we'll talk about win Basics and we'll + + + align:start position:0% +we'll talk about win Basics and we'll +use that to illustrate capacity factors + + align:start position:0% +use that to illustrate capacity factors + + + align:start position:0% +use that to illustrate capacity factors +and levelized costs of energy + + align:start position:0% +and levelized costs of energy + + + align:start position:0% +and levelized costs of energy +on the next lecture we'll talk about + + align:start position:0% +on the next lecture we'll talk about + + + align:start position:0% +on the next lecture we'll talk about +solar Basics including adoption costs + + align:start position:0% +solar Basics including adoption costs + + + align:start position:0% +solar Basics including adoption costs +learning curves and citing issues + + align:start position:0% +learning curves and citing issues + + + align:start position:0% +learning curves and citing issues +and then the third lecture from now + + align:start position:0% +and then the third lecture from now + + + align:start position:0% +and then the third lecture from now +we'll talk about storage and geothermal + + align:start position:0% +we'll talk about storage and geothermal + + + align:start position:0% +we'll talk about storage and geothermal +as examples of how we might develop new + + align:start position:0% +as examples of how we might develop new + + + align:start position:0% +as examples of how we might develop new +niches or new technologies in the + + align:start position:0% +niches or new technologies in the + + + align:start position:0% +niches or new technologies in the +existing Energy System + + align:start position:0% +existing Energy System + + + align:start position:0% +existing Energy System +uh renewable energy potential what is it + + align:start position:0% +uh renewable energy potential what is it + + + align:start position:0% +uh renewable energy potential what is it +uh there's a potential amount of + + align:start position:0% +uh there's a potential amount of + + + align:start position:0% +uh there's a potential amount of +renewable resource that can be generated + + align:start position:0% +renewable resource that can be generated + + + align:start position:0% +renewable resource that can be generated +if you want to see maps for pretty much + + align:start position:0% +if you want to see maps for pretty much + + + align:start position:0% +if you want to see maps for pretty much +every country in the world or globally + + align:start position:0% +every country in the world or globally + + + align:start position:0% +every country in the world or globally +you can see the international renewable + + align:start position:0% +you can see the international renewable + + + align:start position:0% +you can see the international renewable +energy agency uh Irena has a very good + + align:start position:0% +energy agency uh Irena has a very good + + + align:start position:0% +energy agency uh Irena has a very good +resource of renewable energy potential + + align:start position:0% +resource of renewable energy potential + + + align:start position:0% +resource of renewable energy potential +studies uh I already know it's found in + + align:start position:0% +studies uh I already know it's found in + + + align:start position:0% +studies uh I already know it's found in +2009 it's the agency specifically + + align:start position:0% +2009 it's the agency specifically + + + align:start position:0% +2009 it's the agency specifically +focused on Renewables if you go to this + + align:start position:0% +focused on Renewables if you go to this + + + align:start position:0% +focused on Renewables if you go to this +link you can see potential studies and + + align:start position:0% +link you can see potential studies and + + + align:start position:0% +link you can see potential studies and +they have 10 000 studies on five major + + align:start position:0% +they have 10 000 studies on five major + + + align:start position:0% +they have 10 000 studies on five major +categories of Renewables and I think you + + align:start position:0% +categories of Renewables and I think you + + + align:start position:0% +categories of Renewables and I think you +can see which countries have been + + align:start position:0% +can see which countries have been + + + align:start position:0% +can see which countries have been +studied for your papers for this class + + align:start position:0% +studied for your papers for this class + + + align:start position:0% +studied for your papers for this class +so getting back to this graph I touched + + align:start position:0% +so getting back to this graph I touched + + + align:start position:0% +so getting back to this graph I touched +on this a little bit I think in the last + + align:start position:0% +on this a little bit I think in the last + + + align:start position:0% +on this a little bit I think in the last +lecture the price of electricity from + + align:start position:0% +lecture the price of electricity from + + + align:start position:0% +lecture the price of electricity from +new power plants has drastically changed + + align:start position:0% +new power plants has drastically changed + + + align:start position:0% +new power plants has drastically changed +over time a lot of these arrows in 2009 + + align:start position:0% +over time a lot of these arrows in 2009 + + + align:start position:0% +over time a lot of these arrows in 2009 +nuclear has gone more expensive solar + + align:start position:0% +nuclear has gone more expensive solar + + + align:start position:0% +nuclear has gone more expensive solar +thermal has decreased slightly full + + align:start position:0% +thermal has decreased slightly full + + + align:start position:0% +thermal has decreased slightly full +power has not changed at all natural gas + + align:start position:0% +power has not changed at all natural gas + + + align:start position:0% +power has not changed at all natural gas +peaking plants and combined cycle plants + + align:start position:0% +peaking plants and combined cycle plants + + + align:start position:0% +peaking plants and combined cycle plants +have both decreased in the cost of + + align:start position:0% +have both decreased in the cost of + + + align:start position:0% +have both decreased in the cost of +electricity of new power plants but of + + align:start position:0% +electricity of new power plants but of + + + align:start position:0% +electricity of new power plants but of +course the two most drastic lines or the + + align:start position:0% +course the two most drastic lines or the + + + align:start position:0% +course the two most drastic lines or the +steepest slopes on this chart + + align:start position:0% +steepest slopes on this chart + + + align:start position:0% +steepest slopes on this chart +is the price of electricity from solar + + align:start position:0% +is the price of electricity from solar + + + align:start position:0% +is the price of electricity from solar +declining by about 90 in the last 10 + + align:start position:0% +declining by about 90 in the last 10 + + + align:start position:0% +declining by about 90 in the last 10 +years and the price of onshore wind + + align:start position:0% +years and the price of onshore wind + + + align:start position:0% +years and the price of onshore wind +electricity depending about 70 over the + + align:start position:0% +electricity depending about 70 over the + + + align:start position:0% +electricity depending about 70 over the +last 10 years + + align:start position:0% +last 10 years + + + align:start position:0% +last 10 years +just again highlight that the price of + + align:start position:0% +just again highlight that the price of + + + align:start position:0% +just again highlight that the price of +onshore with electricity is declined by + + align:start position:0% +onshore with electricity is declined by + + + align:start position:0% +onshore with electricity is declined by +70 in the past 10 years and we have a + + align:start position:0% +70 in the past 10 years and we have a + + + align:start position:0% +70 in the past 10 years and we have a +very large installed base of wind + + align:start position:0% +very large installed base of wind + + + align:start position:0% +very large installed base of wind +just to kind of look at our win Basics + + align:start position:0% +just to kind of look at our win Basics + + + align:start position:0% +just to kind of look at our win Basics +uh these are all graphs from The High + + align:start position:0% +uh these are all graphs from The High + + + align:start position:0% +uh these are all graphs from The High +chapter that you all read for this class + + align:start position:0% +chapter that you all read for this class + + + align:start position:0% +chapter that you all read for this class +wind power is essentially just picking a + + align:start position:0% +wind power is essentially just picking a + + + align:start position:0% +wind power is essentially just picking a +wind you have some kind of volume air + + align:start position:0% +wind you have some kind of volume air + + + align:start position:0% +wind you have some kind of volume air +hit your wind turbine it gets slightly + + align:start position:0% +hit your wind turbine it gets slightly + + + align:start position:0% +hit your wind turbine it gets slightly +displaced by the Obstacle of the wind + + align:start position:0% +displaced by the Obstacle of the wind + + + align:start position:0% +displaced by the Obstacle of the wind +turbine until it blows and you're taking + + align:start position:0% +turbine until it blows and you're taking + + + align:start position:0% +turbine until it blows and you're taking +some amount of energy off out of the + + align:start position:0% +some amount of energy off out of the + + + align:start position:0% +some amount of energy off out of the +wind this rule of thumb in makai's book + + align:start position:0% +wind this rule of thumb in makai's book + + + align:start position:0% +wind this rule of thumb in makai's book +is that the wind turbine should be about + + align:start position:0% +is that the wind turbine should be about + + + align:start position:0% +is that the wind turbine should be about +five diameters apart I think that's + + align:start position:0% +five diameters apart I think that's + + + align:start position:0% +five diameters apart I think that's +probably changed and it's gotten more + + align:start position:0% +probably changed and it's gotten more + + + align:start position:0% +probably changed and it's gotten more +sophisticated over time Michael Howland + + align:start position:0% +sophisticated over time Michael Howland + + + align:start position:0% +sophisticated over time Michael Howland +a new faculty member in the department + + align:start position:0% +a new faculty member in the department + + + align:start position:0% +a new faculty member in the department +of civil engineering studies uh the + + align:start position:0% +of civil engineering studies uh the + + + align:start position:0% +of civil engineering studies uh the +operation of wind turbine leaves on how + + align:start position:0% +operation of wind turbine leaves on how + + + align:start position:0% +operation of wind turbine leaves on how +to optimize them + + align:start position:0% +to optimize them + + + align:start position:0% +to optimize them +and of course the important point that + + align:start position:0% +and of course the important point that + + + align:start position:0% +and of course the important point that +Makai makes is that the wind speed + + align:start position:0% +Makai makes is that the wind speed + + + align:start position:0% +Makai makes is that the wind speed +changes versus the height off of the + + align:start position:0% +changes versus the height off of the + + + align:start position:0% +changes versus the height off of the +ground you can see that the wind speed + + align:start position:0% +ground you can see that the wind speed + + + align:start position:0% +ground you can see that the wind speed +comes quite a bit higher and the power + + align:start position:0% +comes quite a bit higher and the power + + + align:start position:0% +comes quite a bit higher and the power +density that you can extract from the + + align:start position:0% +density that you can extract from the + + + align:start position:0% +density that you can extract from the +wind goes up actually non-linearly off + + align:start position:0% +wind goes up actually non-linearly off + + + align:start position:0% +wind goes up actually non-linearly off +the ground so in other words the bigger + + align:start position:0% +the ground so in other words the bigger + + + align:start position:0% +the ground so in other words the bigger +you make the turbine the higher off the + + align:start position:0% +you make the turbine the higher off the + + + align:start position:0% +you make the turbine the higher off the +ground the more wind power is there the + + align:start position:0% +ground the more wind power is there the + + + align:start position:0% +ground the more wind power is there the +mowing speed is there and the power + + align:start position:0% +mowing speed is there and the power + + + align:start position:0% +mowing speed is there and the power +density goes at the nonlinear function + + align:start position:0% +density goes at the nonlinear function + + + align:start position:0% +density goes at the nonlinear function +of the wind speed the more power can be + + align:start position:0% +of the wind speed the more power can be + + + align:start position:0% +of the wind speed the more power can be +extracted from this volume of air + + align:start position:0% +extracted from this volume of air + + + align:start position:0% +extracted from this volume of air +that's going to be our occurring theme + + align:start position:0% +that's going to be our occurring theme + + + align:start position:0% +that's going to be our occurring theme +as we look at wind turbines and wind + + align:start position:0% +as we look at wind turbines and wind + + + align:start position:0% +as we look at wind turbines and wind +power and where might go + + align:start position:0% +power and where might go + + + align:start position:0% +power and where might go +uh looking the department of energy + + align:start position:0% +uh looking the department of energy + + + align:start position:0% +uh looking the department of energy +United States produces a land-based wind + + align:start position:0% +United States produces a land-based wind + + + align:start position:0% +United States produces a land-based wind +market report in 2022 here they just map + + align:start position:0% +market report in 2022 here they just map + + + align:start position:0% +market report in 2022 here they just map +the wind speed at 100 meters off the + + align:start position:0% +the wind speed at 100 meters off the + + + align:start position:0% +the wind speed at 100 meters off the +ground they map it against these + + align:start position:0% +ground they map it against these + + + align:start position:0% +ground they map it against these +different regions which are tracked + + align:start position:0% +different regions which are tracked + + + align:start position:0% +different regions which are tracked +along different Regional transmission or + + align:start position:0% +along different Regional transmission or + + + align:start position:0% +along different Regional transmission or +interest system interconnected system + + align:start position:0% +interest system interconnected system + + + align:start position:0% +interest system interconnected system +operators these are all different + + align:start position:0% +operators these are all different + + + align:start position:0% +operators these are all different +regions of the electric grid it's + + align:start position:0% +regions of the electric grid it's + + + align:start position:0% +regions of the electric grid it's +relevant because wind is going to plug + + align:start position:0% +relevant because wind is going to plug + + + align:start position:0% +relevant because wind is going to plug +into regions of electric grid that are + + align:start position:0% +into regions of electric grid that are + + + align:start position:0% +into regions of electric grid that are +governed in different ways but the most + + align:start position:0% +governed in different ways but the most + + + align:start position:0% +governed in different ways but the most +important thing is that you can see that + + align:start position:0% +important thing is that you can see that + + + align:start position:0% +important thing is that you can see that +most of the power wind power are the + + align:start position:0% +most of the power wind power are the + + + align:start position:0% +most of the power wind power are the +wind speed in the United States is + + align:start position:0% +wind speed in the United States is + + + align:start position:0% +wind speed in the United States is +concentrated here in the middle part of + + align:start position:0% +concentrated here in the middle part of + + + align:start position:0% +concentrated here in the middle part of +the country that's concentrated in exits + + align:start position:0% +the country that's concentrated in exits + + + align:start position:0% +the country that's concentrated in exits +this is the region of the electric + + align:start position:0% +this is the region of the electric + + + align:start position:0% +this is the region of the electric +reliability Council of Texas the + + align:start position:0% +reliability Council of Texas the + + + align:start position:0% +reliability Council of Texas the +Southwest power pool constitutes much of + + align:start position:0% +Southwest power pool constitutes much of + + + align:start position:0% +Southwest power pool constitutes much of +the Midwest here and the Mid-Continental + + align:start position:0% +the Midwest here and the Mid-Continental + + + align:start position:0% +the Midwest here and the Mid-Continental +inter-system operator operates much in + + align:start position:0% +inter-system operator operates much in + + + align:start position:0% +inter-system operator operates much in +this part of the Midwest so our wind + + align:start position:0% +this part of the Midwest so our wind + + + align:start position:0% +this part of the Midwest so our wind +power is clearly concentrated on land in + + align:start position:0% +power is clearly concentrated on land in + + + align:start position:0% +power is clearly concentrated on land in +the middle of our country + + align:start position:0% +the middle of our country + + + align:start position:0% +the middle of our country +and if you look at the win market report + + align:start position:0% +and if you look at the win market report + + + align:start position:0% +and if you look at the win market report +it's been exciting to pack it over the + + align:start position:0% +it's been exciting to pack it over the + + + align:start position:0% +it's been exciting to pack it over the +last few years because you can see over + + align:start position:0% +last few years because you can see over + + + align:start position:0% +last few years because you can see over +the last few years these are the + + align:start position:0% +the last few years these are the + + + align:start position:0% +the last few years these are the +cumulative total capacity added + + align:start position:0% +cumulative total capacity added + + + align:start position:0% +cumulative total capacity added +and the cumulative total capacity has of + + align:start position:0% +and the cumulative total capacity has of + + + align:start position:0% +and the cumulative total capacity has of +course gone steadily up over the last 22 + + align:start position:0% +course gone steadily up over the last 22 + + + align:start position:0% +course gone steadily up over the last 22 +years but if you look at the capacity + + align:start position:0% +years but if you look at the capacity + + + align:start position:0% +years but if you look at the capacity +Edition additions you can see that every + + align:start position:0% +Edition additions you can see that every + + + align:start position:0% +Edition additions you can see that every +single year we're adding much more + + align:start position:0% +single year we're adding much more + + + align:start position:0% +single year we're adding much more +capacity of wind power in fact until + + align:start position:0% +capacity of wind power in fact until + + + align:start position:0% +capacity of wind power in fact until +this last year until 2020 for four + + align:start position:0% +this last year until 2020 for four + + + align:start position:0% +this last year until 2020 for four +straight years the capacity had + + align:start position:0% +straight years the capacity had + + + align:start position:0% +straight years the capacity had +increased and you can see that almost + + align:start position:0% +increased and you can see that almost + + + align:start position:0% +increased and you can see that almost +quite regularly we're starting to break + + align:start position:0% +quite regularly we're starting to break + + + align:start position:0% +quite regularly we're starting to break +records for how much past they were + + align:start position:0% +records for how much past they were + + + align:start position:0% +records for how much past they were +adding in any given year + + align:start position:0% +adding in any given year + + + align:start position:0% +adding in any given year +2021 slowed slightly + + align:start position:0% +2021 slowed slightly + + + align:start position:0% +2021 slowed slightly +but you can see that a lot of this + + align:start position:0% +but you can see that a lot of this + + + align:start position:0% +but you can see that a lot of this +capacity is being added in certain + + align:start position:0% +capacity is being added in certain + + + align:start position:0% +capacity is being added in certain +regions and those are those three + + align:start position:0% +regions and those are those three + + + align:start position:0% +regions and those are those three +regions I showed you the map before + + align:start position:0% +regions I showed you the map before + + + align:start position:0% +regions I showed you the map before +Texas the Southwest power pool and the + + align:start position:0% +Texas the Southwest power pool and the + + + align:start position:0% +Texas the Southwest power pool and the +Mid-Continental inter-system operator + + align:start position:0% +Mid-Continental inter-system operator + + + align:start position:0% +Mid-Continental inter-system operator +if you look at where wind stands in our + + align:start position:0% +if you look at where wind stands in our + + + align:start position:0% +if you look at where wind stands in our +capacity conditions another exciting + + align:start position:0% +capacity conditions another exciting + + + align:start position:0% +capacity conditions another exciting +part of the story is that this is from + + align:start position:0% +part of the story is that this is from + + + align:start position:0% +part of the story is that this is from +the weed market report it shows Uber + + align:start position:0% +the weed market report it shows Uber + + + align:start position:0% +the weed market report it shows Uber +years well how much capacity how much + + align:start position:0% +years well how much capacity how much + + + align:start position:0% +years well how much capacity how much +capacity are we adding to the grid to + + align:start position:0% +capacity are we adding to the grid to + + + align:start position:0% +capacity are we adding to the grid to +generate electric power you can see + + align:start position:0% +generate electric power you can see + + + align:start position:0% +generate electric power you can see +overwhelmingly it is coming from wind + + align:start position:0% +overwhelmingly it is coming from wind + + + align:start position:0% +overwhelmingly it is coming from wind +solar and storage over the last few + + align:start position:0% +solar and storage over the last few + + + align:start position:0% +solar and storage over the last few +years natural gas and light blue have + + align:start position:0% +years natural gas and light blue have + + + align:start position:0% +years natural gas and light blue have +had some years of growth but it's + + align:start position:0% +had some years of growth but it's + + + align:start position:0% +had some years of growth but it's +steadily becoming a smaller part of our + + align:start position:0% +steadily becoming a smaller part of our + + + align:start position:0% +steadily becoming a smaller part of our +capacity additions our capacity + + align:start position:0% +capacity additions our capacity + + + align:start position:0% +capacity additions our capacity +additions to our electricity system are + + align:start position:0% +additions to our electricity system are + + + align:start position:0% +additions to our electricity system are +almost entirely wind solar and storage + + align:start position:0% +almost entirely wind solar and storage + + + align:start position:0% +almost entirely wind solar and storage +wind for the first time has I think + + align:start position:0% +wind for the first time has I think + + + align:start position:0% +wind for the first time has I think +fallen in the second place from solar it + + align:start position:0% +fallen in the second place from solar it + + + align:start position:0% +fallen in the second place from solar it +used to be a few years here it looked + + align:start position:0% +used to be a few years here it looked + + + align:start position:0% +used to be a few years here it looked +like solar is actually larger but now + + align:start position:0% +like solar is actually larger but now + + + align:start position:0% +like solar is actually larger but now +swim is clearly in the second position + + align:start position:0% +swim is clearly in the second position + + + align:start position:0% +swim is clearly in the second position +solar is the biggest capacity Edition + + align:start position:0% +solar is the biggest capacity Edition + + + align:start position:0% +solar is the biggest capacity Edition +being added to the grid this is the + + align:start position:0% +being added to the grid this is the + + + align:start position:0% +being added to the grid this is the +capacity the ability to generate power + + align:start position:0% +capacity the ability to generate power + + + align:start position:0% +capacity the ability to generate power +in gigawatts that doesn't necessarily + + align:start position:0% +in gigawatts that doesn't necessarily + + + align:start position:0% +in gigawatts that doesn't necessarily +mean that capacity is being used all the + + align:start position:0% +mean that capacity is being used all the + + + align:start position:0% +mean that capacity is being used all the +time which we will talk about we talk + + align:start position:0% +time which we will talk about we talk + + + align:start position:0% +time which we will talk about we talk +about intermittency + + align:start position:0% +about intermittency + + + align:start position:0% +about intermittency +but finally if we look at the different + + align:start position:0% +but finally if we look at the different + + + align:start position:0% +but finally if we look at the different +regions again wind is quite dominant in + + align:start position:0% +regions again wind is quite dominant in + + + align:start position:0% +regions again wind is quite dominant in +the middle of the country in the + + align:start position:0% +the middle of the country in the + + + align:start position:0% +the middle of the country in the +southwest power pool in the electric + + align:start position:0% +southwest power pool in the electric + + + align:start position:0% +southwest power pool in the electric +reliability Council of Texas and the mid + + align:start position:0% +reliability Council of Texas and the mid + + + align:start position:0% +reliability Council of Texas and the mid +Continental inter-system operator you + + align:start position:0% +Continental inter-system operator you + + + align:start position:0% +Continental inter-system operator you +can see all these errors are quite + + align:start position:0% +can see all these errors are quite + + + align:start position:0% +can see all these errors are quite +dominated by wind other parts of the + + align:start position:0% +dominated by wind other parts of the + + + align:start position:0% +dominated by wind other parts of the +country are more dominated by solar and + + align:start position:0% +country are more dominated by solar and + + + align:start position:0% +country are more dominated by solar and +natural gas + + align:start position:0% + + + + align:start position:0% + +so just to give you an example of what + + align:start position:0% +so just to give you an example of what + + + align:start position:0% +so just to give you an example of what +these optional wind turbines look like + + align:start position:0% +these optional wind turbines look like + + + align:start position:0% +these optional wind turbines look like +this is actually a plain uh picture I + + align:start position:0% +this is actually a plain uh picture I + + + align:start position:0% +this is actually a plain uh picture I +took out of a plane window and I was + + align:start position:0% +took out of a plane window and I was + + + align:start position:0% +took out of a plane window and I was +flying I think over the North Sea in + + align:start position:0% +flying I think over the North Sea in + + + align:start position:0% +flying I think over the North Sea in +Europe this is I think off the coast of + + align:start position:0% +Europe this is I think off the coast of + + + align:start position:0% +Europe this is I think off the coast of +Poland and this just gives you a sense + + align:start position:0% +Poland and this just gives you a sense + + + align:start position:0% +Poland and this just gives you a sense +of what you can see from a plane there's + + align:start position:0% +of what you can see from a plane there's + + + align:start position:0% +of what you can see from a plane there's +a little yep probably not a little ship + + align:start position:0% +a little yep probably not a little ship + + + align:start position:0% +a little yep probably not a little ship +sailing between these wind turbines but + + align:start position:0% +sailing between these wind turbines but + + + align:start position:0% +sailing between these wind turbines but +these wind turbines are simply off tour + + align:start position:0% +these wind turbines are simply off tour + + + align:start position:0% +these wind turbines are simply off tour +where we know more wind is flowing + + align:start position:0% +where we know more wind is flowing + + + align:start position:0% +where we know more wind is flowing +I have to give you another picture this + + align:start position:0% +I have to give you another picture this + + + align:start position:0% +I have to give you another picture this +is a picture of uh of officero wind + + align:start position:0% +is a picture of uh of officero wind + + + align:start position:0% +is a picture of uh of officero wind +turbines in Europe which tends to have + + align:start position:0% +turbines in Europe which tends to have + + + align:start position:0% +turbines in Europe which tends to have +shallower Waters in the U.S but you have + + align:start position:0% +shallower Waters in the U.S but you have + + + align:start position:0% +shallower Waters in the U.S but you have +it looks like a ferry and you have a + + align:start position:0% +it looks like a ferry and you have a + + + align:start position:0% +it looks like a ferry and you have a +sailboat sailing through + + align:start position:0% +sailboat sailing through + + + align:start position:0% +sailboat sailing through +and the reason why it's exciting to talk + + align:start position:0% +and the reason why it's exciting to talk + + + align:start position:0% +and the reason why it's exciting to talk +about uh wind offshore is that if you + + align:start position:0% +about uh wind offshore is that if you + + + align:start position:0% +about uh wind offshore is that if you +look at the average wind speed above + + align:start position:0% +look at the average wind speed above + + + align:start position:0% +look at the average wind speed above +North America you can see that there is + + align:start position:0% +North America you can see that there is + + + align:start position:0% +North America you can see that there is +this concentration of wind power in the + + align:start position:0% +this concentration of wind power in the + + + align:start position:0% +this concentration of wind power in the +center of the country but very + + align:start position:0% +center of the country but very + + + align:start position:0% +center of the country but very +importantly you actually have very high + + align:start position:0% +importantly you actually have very high + + + align:start position:0% +importantly you actually have very high +wind speeds off the coast of the U.S + + align:start position:0% +wind speeds off the coast of the U.S + + + align:start position:0% +wind speeds off the coast of the U.S +this probably doesn't go all the way + + align:start position:0% +this probably doesn't go all the way + + + align:start position:0% +this probably doesn't go all the way +out into the ocean this is probably just + + align:start position:0% +out into the ocean this is probably just + + + align:start position:0% +out into the ocean this is probably just +map long Continental Health but you can + + align:start position:0% +map long Continental Health but you can + + + align:start position:0% +map long Continental Health but you can +see the concentrations of wind are just + + align:start position:0% +see the concentrations of wind are just + + + align:start position:0% +see the concentrations of wind are just +as high if not higher than the middle of + + align:start position:0% +as high if not higher than the middle of + + + align:start position:0% +as high if not higher than the middle of +the country but also quite importantly + + align:start position:0% +the country but also quite importantly + + + align:start position:0% +the country but also quite importantly +there these wind powers or wind + + align:start position:0% +there these wind powers or wind + + + align:start position:0% +there these wind powers or wind +potential are located very close to the + + align:start position:0% +potential are located very close to the + + + align:start position:0% +potential are located very close to the +population center of the us we know most + + align:start position:0% +population center of the us we know most + + + align:start position:0% +population center of the us we know most +the population of the US is actually + + align:start position:0% +the population of the US is actually + + + align:start position:0% +the population of the US is actually +complicated along the coasts and so it's + + align:start position:0% +complicated along the coasts and so it's + + + align:start position:0% +complicated along the coasts and so it's +important to generate renewable energy + + align:start position:0% +important to generate renewable energy + + + align:start position:0% +important to generate renewable energy +close to the populations because it + + align:start position:0% +close to the populations because it + + + align:start position:0% +close to the populations because it +minimizes our need to transmit the power + + align:start position:0% +minimizes our need to transmit the power + + + align:start position:0% +minimizes our need to transmit the power +through the grid so we will need more + + align:start position:0% +through the grid so we will need more + + + align:start position:0% +through the grid so we will need more +transmission lines for the grid also + + align:start position:0% +transmission lines for the grid also + + + align:start position:0% +transmission lines for the grid also +so just to give you a sense of what + + align:start position:0% +so just to give you a sense of what + + + align:start position:0% +so just to give you a sense of what +these floating what floating wind + + align:start position:0% +these floating what floating wind + + + align:start position:0% +these floating what floating wind +turbines can look like off the shore of + + align:start position:0% +turbines can look like off the shore of + + + align:start position:0% +turbines can look like off the shore of +the U.S here's three different ways of + + align:start position:0% +the U.S here's three different ways of + + + align:start position:0% +the U.S here's three different ways of +anchoring and floating wind turbine to + + align:start position:0% +anchoring and floating wind turbine to + + + align:start position:0% +anchoring and floating wind turbine to +the ocean floor you have one that has + + align:start position:0% +the ocean floor you have one that has + + + align:start position:0% +the ocean floor you have one that has +this big kind of counterweight to keep + + align:start position:0% +this big kind of counterweight to keep + + + align:start position:0% +this big kind of counterweight to keep +it upright you have these this kind of + + align:start position:0% +it upright you have these this kind of + + + align:start position:0% +it upright you have these this kind of +tripod system with three anchors and you + + align:start position:0% +tripod system with three anchors and you + + + align:start position:0% +tripod system with three anchors and you +have a different tripod system all meant + + align:start position:0% +have a different tripod system all meant + + + align:start position:0% +have a different tripod system all meant +to Anchor wind turbines offshore + + align:start position:0% +to Anchor wind turbines offshore + + + align:start position:0% +to Anchor wind turbines offshore +of course just to give you a sense + + align:start position:0% +of course just to give you a sense + + + align:start position:0% +of course just to give you a sense +of where this technical potential is + + align:start position:0% +of where this technical potential is + + + align:start position:0% +of where this technical potential is +located if according to the end result + + align:start position:0% +located if according to the end result + + + align:start position:0% +located if according to the end result +study if you look a place to have + + align:start position:0% +study if you look a place to have + + + align:start position:0% +study if you look a place to have +greater than seven meters per second + + align:start position:0% +greater than seven meters per second + + + align:start position:0% +greater than seven meters per second +wind speed less than a thousand meters + + align:start position:0% +wind speed less than a thousand meters + + + align:start position:0% +wind speed less than a thousand meters +in depth less than 60 meters in depth + + align:start position:0% +in depth less than 60 meters in depth + + + align:start position:0% +in depth less than 60 meters in depth +the great lakes and if you try to avoid + + align:start position:0% +the great lakes and if you try to avoid + + + align:start position:0% +the great lakes and if you try to avoid +conflicting use and environmental + + align:start position:0% +conflicting use and environmental + + + align:start position:0% +conflicting use and environmental +extensions you can see that there they + + align:start position:0% +extensions you can see that there they + + + align:start position:0% +extensions you can see that there they +break each of these bars into the places + + align:start position:0% +break each of these bars into the places + + + align:start position:0% +break each of these bars into the places +where the water depth is greater than 60 + + align:start position:0% +where the water depth is greater than 60 + + + align:start position:0% +where the water depth is greater than 60 +meters and less than 60 meters + + align:start position:0% +meters and less than 60 meters + + + align:start position:0% +meters and less than 60 meters +and you can see surprisingly that one of + + align:start position:0% +and you can see surprisingly that one of + + + align:start position:0% +and you can see surprisingly that one of +the largest states for technical energy + + align:start position:0% +the largest states for technical energy + + + align:start position:0% +the largest states for technical energy +potential is Massachusetts and then + + align:start position:0% +potential is Massachusetts and then + + + align:start position:0% +potential is Massachusetts and then +Florida and then Texas and so on so + + align:start position:0% +Florida and then Texas and so on so + + + align:start position:0% +Florida and then Texas and so on so +these are all offshore wind potentials + + align:start position:0% +these are all offshore wind potentials + + + align:start position:0% +these are all offshore wind potentials +for different states but this is also to + + align:start position:0% +for different states but this is also to + + + align:start position:0% +for different states but this is also to +give you a sense of why it's so + + align:start position:0% +give you a sense of why it's so + + + align:start position:0% +give you a sense of why it's so +important that Massachusetts is pursuing + + align:start position:0% +important that Massachusetts is pursuing + + + align:start position:0% +important that Massachusetts is pursuing +offshore wind energy this is the chance + + align:start position:0% +offshore wind energy this is the chance + + + align:start position:0% +offshore wind energy this is the chance +that Massachusetts has to develop a + + align:start position:0% +that Massachusetts has to develop a + + + align:start position:0% +that Massachusetts has to develop a +renewable energy resources in a highly + + align:start position:0% +renewable energy resources in a highly + + + align:start position:0% +renewable energy resources in a highly +dense area of the country a highly + + align:start position:0% +dense area of the country a highly + + + align:start position:0% +dense area of the country a highly +populated area of the country like + + align:start position:0% +populated area of the country like + + + align:start position:0% +populated area of the country like +Massachusetts we're not going to build + + align:start position:0% +Massachusetts we're not going to build + + + align:start position:0% +Massachusetts we're not going to build +we're not going to be able to build as + + align:start position:0% +we're not going to be able to build as + + + align:start position:0% +we're not going to be able to build as +much solar as other parts of the country + + align:start position:0% +much solar as other parts of the country + + + align:start position:0% +much solar as other parts of the country +and frankly it's not very sunny + + align:start position:0% +and frankly it's not very sunny + + + align:start position:0% +and frankly it's not very sunny +Massachusetts compared to Arizona or + + align:start position:0% +Massachusetts compared to Arizona or + + + align:start position:0% +Massachusetts compared to Arizona or +Hawaii so offshore wind is probably + + align:start position:0% +Hawaii so offshore wind is probably + + + align:start position:0% +Hawaii so offshore wind is probably +going to be our biggest opportunity for + + align:start position:0% +going to be our biggest opportunity for + + + align:start position:0% +going to be our biggest opportunity for +building renewable energy + + align:start position:0% + + + + align:start position:0% + +now what's really exciting is if you + + align:start position:0% +now what's really exciting is if you + + + align:start position:0% +now what's really exciting is if you +look at the Boe the usdoe also does an + + align:start position:0% +look at the Boe the usdoe also does an + + + align:start position:0% +look at the Boe the usdoe also does an +offshore Wing market report every year + + align:start position:0% +offshore Wing market report every year + + + align:start position:0% +offshore Wing market report every year +I've been updating this and so actually + + align:start position:0% +I've been updating this and so actually + + + align:start position:0% +I've been updating this and so actually +it's interesting when you look at the + + align:start position:0% +it's interesting when you look at the + + + align:start position:0% +it's interesting when you look at the +graphics in the report every year they + + align:start position:0% +graphics in the report every year they + + + align:start position:0% +graphics in the report every year they +change because austral win is growing in + + align:start position:0% +change because austral win is growing in + + + align:start position:0% +change because austral win is growing in +fact in fact basically exploding and its + + align:start position:0% +fact in fact basically exploding and its + + + align:start position:0% +fact in fact basically exploding and its +potential so uh last year I think when I + + align:start position:0% +potential so uh last year I think when I + + + align:start position:0% +potential so uh last year I think when I +looked at this map they had the entire + + align:start position:0% +looked at this map they had the entire + + + align:start position:0% +looked at this map they had the entire +Atlantic post was on one map and there + + align:start position:0% +Atlantic post was on one map and there + + + align:start position:0% +Atlantic post was on one map and there +was I think about 20 planned projects + + align:start position:0% +was I think about 20 planned projects + + + align:start position:0% +was I think about 20 planned projects +now there's about 20 31 planned projects + + align:start position:0% +now there's about 20 31 planned projects + + + align:start position:0% +now there's about 20 31 planned projects +in the North Atlantic alone they also + + align:start position:0% +in the North Atlantic alone they also + + + align:start position:0% +in the North Atlantic alone they also +actually sorry 32 because they show uh + + align:start position:0% +actually sorry 32 because they show uh + + + align:start position:0% +actually sorry 32 because they show uh +Lake Erie having a offshore wind project + + align:start position:0% +Lake Erie having a offshore wind project + + + align:start position:0% +Lake Erie having a offshore wind project +some fresh water wind projects there's + + align:start position:0% +some fresh water wind projects there's + + + align:start position:0% +some fresh water wind projects there's +one all the way up in off the coast of + + align:start position:0% +one all the way up in off the coast of + + + align:start position:0% +one all the way up in off the coast of +Maine and you can see this on this graph + + align:start position:0% +Maine and you can see this on this graph + + + align:start position:0% +Maine and you can see this on this graph +that there's about 32 planned win + + align:start position:0% +that there's about 32 planned win + + + align:start position:0% +that there's about 32 planned win +projects + + align:start position:0% +projects + + + align:start position:0% +projects +they all are in different areas off the + + align:start position:0% +they all are in different areas off the + + + align:start position:0% +they all are in different areas off the +coast you can see they occur at + + align:start position:0% +coast you can see they occur at + + + align:start position:0% +coast you can see they occur at +different bathymetric depths they are + + align:start position:0% +different bathymetric depths they are + + + align:start position:0% +different bathymetric depths they are +some of them are leased some of them are + + align:start position:0% +some of them are leased some of them are + + + align:start position:0% +some of them are leased some of them are +dormant areas but these are all areas + + align:start position:0% +dormant areas but these are all areas + + + align:start position:0% +dormant areas but these are all areas +that have explored for offshore wind + + align:start position:0% +that have explored for offshore wind + + + align:start position:0% +that have explored for offshore wind +if you look at the Pacific coast and the + + align:start position:0% +if you look at the Pacific coast and the + + + align:start position:0% +if you look at the Pacific coast and the +South Atlantic now they have separate + + align:start position:0% +South Atlantic now they have separate + + + align:start position:0% +South Atlantic now they have separate +Maps broken out just for these areas you + + align:start position:0% +Maps broken out just for these areas you + + + align:start position:0% +Maps broken out just for these areas you +can see that on the west coast off of + + align:start position:0% +can see that on the west coast off of + + + align:start position:0% +can see that on the west coast off of +Oregon and California there's a number + + align:start position:0% +Oregon and California there's a number + + + align:start position:0% +Oregon and California there's a number +of off-road wind projects planned + + align:start position:0% +of off-road wind projects planned + + + align:start position:0% +of off-road wind projects planned +there's officer when projects planned + + align:start position:0% +there's officer when projects planned + + + align:start position:0% +there's officer when projects planned +off in Hawaii now and leaving the south + + align:start position:0% +off in Hawaii now and leaving the south + + + align:start position:0% +off in Hawaii now and leaving the south +at Landing these are all areas in the + + align:start position:0% +at Landing these are all areas in the + + + align:start position:0% +at Landing these are all areas in the +Gulf of Mexico these are all areas that + + align:start position:0% +Gulf of Mexico these are all areas that + + + align:start position:0% +Gulf of Mexico these are all areas that +weren't even mapped in the last off-road + + align:start position:0% +weren't even mapped in the last off-road + + + align:start position:0% +weren't even mapped in the last off-road +we've marked a report from just last + + align:start position:0% +we've marked a report from just last + + + align:start position:0% +we've marked a report from just last +year so clearly this is an area that is + + align:start position:0% +year so clearly this is an area that is + + + align:start position:0% +year so clearly this is an area that is +growing very rapidly + + align:start position:0% +growing very rapidly + + + align:start position:0% +growing very rapidly +if we look at the pipeline for offshore + + align:start position:0% +if we look at the pipeline for offshore + + + align:start position:0% +if we look at the pipeline for offshore +wind the Striking thing about it to you + + align:start position:0% +wind the Striking thing about it to you + + + align:start position:0% +wind the Striking thing about it to you +should be this classification from what + + align:start position:0% +should be this classification from what + + + align:start position:0% +should be this classification from what +we actually have operating from what's + + align:start position:0% +we actually have operating from what's + + + align:start position:0% +we actually have operating from what's +under construction from what's financial + + align:start position:0% +under construction from what's financial + + + align:start position:0% +under construction from what's financial +opposed what's been approved what's + + align:start position:0% +opposed what's been approved what's + + + align:start position:0% +opposed what's been approved what's +waiting for permitting areas that are + + align:start position:0% +waiting for permitting areas that are + + + align:start position:0% +waiting for permitting areas that are +under site control and areas that are + + align:start position:0% +under site control and areas that are + + + align:start position:0% +under site control and areas that are +being planned if you add all these parts + + align:start position:0% +being planned if you add all these parts + + + align:start position:0% +being planned if you add all these parts +up you get the total pipeline of off + + align:start position:0% +up you get the total pipeline of off + + + align:start position:0% +up you get the total pipeline of off +throw wind expected what you should + + align:start position:0% +throw wind expected what you should + + + align:start position:0% +throw wind expected what you should +notice about this is that four we have + + align:start position:0% +notice about this is that four we have + + + align:start position:0% +notice about this is that four we have +about 40 000 megawatts of optimal wind + + align:start position:0% +about 40 000 megawatts of optimal wind + + + align:start position:0% +about 40 000 megawatts of optimal wind +that's in the pipeline + + align:start position:0% +that's in the pipeline + + + align:start position:0% +that's in the pipeline +that's up about 35 + + align:start position:0% +that's up about 35 + + + align:start position:0% +that's up about 35 +000 megawatts just last year alone but + + align:start position:0% +000 megawatts just last year alone but + + + align:start position:0% +000 megawatts just last year alone but +they're really striking thing to you + + align:start position:0% +they're really striking thing to you + + + align:start position:0% +they're really striking thing to you +should be that of the 40 000 megawatts + + align:start position:0% +should be that of the 40 000 megawatts + + + align:start position:0% +should be that of the 40 000 megawatts +we have planned we only have 42 + + align:start position:0% +we have planned we only have 42 + + + align:start position:0% +we have planned we only have 42 +megawatts operating that's actually I + + align:start position:0% +megawatts operating that's actually I + + + align:start position:0% +megawatts operating that's actually I +think exactly seven offshore wind + + align:start position:0% +think exactly seven offshore wind + + + align:start position:0% +think exactly seven offshore wind +turbines in the US right now + + align:start position:0% +turbines in the US right now + + + align:start position:0% +turbines in the US right now +five off of Rhode Island and two off of + + align:start position:0% +five off of Rhode Island and two off of + + + align:start position:0% +five off of Rhode Island and two off of +Virginia + + align:start position:0% +Virginia + + + align:start position:0% +Virginia +that's all we have operating when we go + + align:start position:0% +that's all we have operating when we go + + + align:start position:0% +that's all we have operating when we go +to under construction we're going to + + align:start position:0% +to under construction we're going to + + + align:start position:0% +to under construction we're going to +effectively I think increase that by a + + align:start position:0% +effectively I think increase that by a + + + align:start position:0% +effectively I think increase that by a +factor of 20. a lot of that is looks + + align:start position:0% +factor of 20. a lot of that is looks + + + align:start position:0% +factor of 20. a lot of that is looks +like in Massachusetts + + align:start position:0% +like in Massachusetts + + + align:start position:0% +like in Massachusetts +and we have very little that's their + + align:start position:0% +and we have very little that's their + + + align:start position:0% +and we have very little that's their +financially closed and financially + + align:start position:0% +financially closed and financially + + + align:start position:0% +financially closed and financially +approved but if you look at the states + + align:start position:0% +approved but if you look at the states + + + align:start position:0% +approved but if you look at the states +that are permitted off girl wind it's + + align:start position:0% +that are permitted off girl wind it's + + + align:start position:0% +that are permitted off girl wind it's +New York Massachusetts New Jersey North + + align:start position:0% +New York Massachusetts New Jersey North + + + align:start position:0% +New York Massachusetts New Jersey North +Carolina Virginia Maryland all up and + + align:start position:0% +Carolina Virginia Maryland all up and + + + align:start position:0% +Carolina Virginia Maryland all up and +down the East Coast we have a lot of + + align:start position:0% +down the East Coast we have a lot of + + + align:start position:0% +down the East Coast we have a lot of +Permitting a lot of permits that need to + + align:start position:0% +Permitting a lot of permits that need to + + + align:start position:0% +Permitting a lot of permits that need to +be extradited or need to be achieved or + + align:start position:0% +be extradited or need to be achieved or + + + align:start position:0% +be extradited or need to be achieved or +approved for these projects to go + + align:start position:0% +approved for these projects to go + + + align:start position:0% +approved for these projects to go +forward in terms of areas that have + + align:start position:0% +forward in terms of areas that have + + + align:start position:0% +forward in terms of areas that have +people developers have achieved psych + + align:start position:0% +people developers have achieved psych + + + align:start position:0% +people developers have achieved psych +control + + align:start position:0% +control + + + align:start position:0% +control +a large majority of that is in New York + + align:start position:0% +a large majority of that is in New York + + + align:start position:0% +a large majority of that is in New York +and Massachusetts + + align:start position:0% +and Massachusetts + + + align:start position:0% +and Massachusetts +and then in terms of planning we have + + align:start position:0% +and then in terms of planning we have + + + align:start position:0% +and then in terms of planning we have +quite a bit of planning for offshore + + align:start position:0% +quite a bit of planning for offshore + + + align:start position:0% +quite a bit of planning for offshore +wind in California but again if you add + + align:start position:0% +wind in California but again if you add + + + align:start position:0% +wind in California but again if you add +this whole pipeline together of the 40 + + align:start position:0% +this whole pipeline together of the 40 + + + align:start position:0% +this whole pipeline together of the 40 +000 megawatts we have in our total + + align:start position:0% +000 megawatts we have in our total + + + align:start position:0% +000 megawatts we have in our total +pipeline we only have 42 megawatts + + align:start position:0% +pipeline we only have 42 megawatts + + + align:start position:0% +pipeline we only have 42 megawatts +operating which is 0.1 percent so we + + align:start position:0% +operating which is 0.1 percent so we + + + align:start position:0% +operating which is 0.1 percent so we +obviously have big Ambitions for + + align:start position:0% +obviously have big Ambitions for + + + align:start position:0% +obviously have big Ambitions for +offshore wind but we haven't realized + + align:start position:0% +offshore wind but we haven't realized + + + align:start position:0% +offshore wind but we haven't realized +99.9 of the actual wind capacity yet + + align:start position:0% +99.9 of the actual wind capacity yet + + + align:start position:0% +99.9 of the actual wind capacity yet +if you look at these states and the wind + + align:start position:0% +if you look at these states and the wind + + + align:start position:0% +if you look at these states and the wind +pipeline by state you can also think + + align:start position:0% +pipeline by state you can also think + + + align:start position:0% +pipeline by state you can also think +about how this fits into the energy + + align:start position:0% +about how this fits into the energy + + + align:start position:0% +about how this fits into the energy +policies currently quite a bit of New + + align:start position:0% +policies currently quite a bit of New + + + align:start position:0% +policies currently quite a bit of New +York's potential is under site control + + align:start position:0% +York's potential is under site control + + + align:start position:0% +York's potential is under site control +and quite a bit is being permitted and a + + align:start position:0% +and quite a bit is being permitted and a + + + align:start position:0% +and quite a bit is being permitted and a +very small course should be under + + align:start position:0% +very small course should be under + + + align:start position:0% +very small course should be under +construction a Massachusetts had less + + align:start position:0% +construction a Massachusetts had less + + + align:start position:0% +construction a Massachusetts had less +total wind offshore pipeline but has + + align:start position:0% +total wind offshore pipeline but has + + + align:start position:0% +total wind offshore pipeline but has +less Underside control more in + + align:start position:0% +less Underside control more in + + + align:start position:0% +less Underside control more in +permitting and more Under Construction + + align:start position:0% +permitting and more Under Construction + + + align:start position:0% +permitting and more Under Construction +New Jersey is almost entirely in the + + align:start position:0% +New Jersey is almost entirely in the + + + align:start position:0% +New Jersey is almost entirely in the +permitting phase and so on and so on + + align:start position:0% +permitting phase and so on and so on + + + align:start position:0% +permitting phase and so on and so on +but let's just to give you a sense of + + align:start position:0% +but let's just to give you a sense of + + + align:start position:0% +but let's just to give you a sense of +how big these wind turbine blades are + + align:start position:0% +how big these wind turbine blades are + + + align:start position:0% +how big these wind turbine blades are +this is a graphic of the heli X turbine + + align:start position:0% +this is a graphic of the heli X turbine + + + align:start position:0% +this is a graphic of the heli X turbine +a new turbine introduced by GE just a + + align:start position:0% +a new turbine introduced by GE just a + + + align:start position:0% +a new turbine introduced by GE just a +couple years ago + + align:start position:0% +couple years ago + + + align:start position:0% +couple years ago +and just to give you an example this is + + align:start position:0% +and just to give you an example this is + + + align:start position:0% +and just to give you an example this is +the Statue of Liberty of 305 feet the + + align:start position:0% +the Statue of Liberty of 305 feet the + + + align:start position:0% +the Statue of Liberty of 305 feet the +Empire State Building the Eiffel Tower + + align:start position:0% +Empire State Building the Eiffel Tower + + + align:start position:0% +Empire State Building the Eiffel Tower +the average onshore turbine is 466 feet + + align:start position:0% +the average onshore turbine is 466 feet + + + align:start position:0% +the average onshore turbine is 466 feet +tall the tallest U.S turbine the tallest + + align:start position:0% +tall the tallest U.S turbine the tallest + + + align:start position:0% +tall the tallest U.S turbine the tallest +turbine you've probably seen on Shore is + + align:start position:0% +turbine you've probably seen on Shore is + + + align:start position:0% +turbine you've probably seen on Shore is +574 feet tall the new GE heliight X is + + align:start position:0% +574 feet tall the new GE heliight X is + + + align:start position:0% +574 feet tall the new GE heliight X is +853 feet tall the current the five uh + + align:start position:0% +853 feet tall the current the five uh + + + align:start position:0% +853 feet tall the current the five uh +weed turbines we have operating in the + + align:start position:0% +weed turbines we have operating in the + + + align:start position:0% +weed turbines we have operating in the +US are off of Rhode Island are only 590 + + align:start position:0% +US are off of Rhode Island are only 590 + + + align:start position:0% +US are off of Rhode Island are only 590 +feet tall so G can build these turbines + + align:start position:0% +feet tall so G can build these turbines + + + align:start position:0% +feet tall so G can build these turbines +they've introduced us as a product but + + align:start position:0% +they've introduced us as a product but + + + align:start position:0% +they've introduced us as a product but +clearly these turbines are very large I + + align:start position:0% +clearly these turbines are very large I + + + align:start position:0% +clearly these turbines are very large I +think each of those blades is one or two + + align:start position:0% +think each of those blades is one or two + + + align:start position:0% +think each of those blades is one or two +aircraft Wings long + + align:start position:0% +aircraft Wings long + + + align:start position:0% +aircraft Wings long +so you know just to give you a sense + + align:start position:0% +so you know just to give you a sense + + + align:start position:0% +so you know just to give you a sense +um the uh the total height of the new + + align:start position:0% +um the uh the total height of the new + + + align:start position:0% +um the uh the total height of the new +Helia X wind turbine is three times the + + align:start position:0% +Helia X wind turbine is three times the + + + align:start position:0% +Helia X wind turbine is three times the +flat iron building the diameter is + + align:start position:0% +flat iron building the diameter is + + + align:start position:0% +flat iron building the diameter is +equivalent to the Golden Gate Bridge + + align:start position:0% +equivalent to the Golden Gate Bridge + + + align:start position:0% +equivalent to the Golden Gate Bridge +tower height above the water and the + + align:start position:0% +tower height above the water and the + + + align:start position:0% +tower height above the water and the +surface of the blade sweep is equivalent + + align:start position:0% +surface of the blade sweep is equivalent + + + align:start position:0% +surface of the blade sweep is equivalent +to seven American football fields + + align:start position:0% +to seven American football fields + + + align:start position:0% +to seven American football fields +single one of these turbines can + + align:start position:0% +single one of these turbines can + + + align:start position:0% +single one of these turbines can +generate 67 gigawatt hours annually + + align:start position:0% +generate 67 gigawatt hours annually + + + align:start position:0% +generate 67 gigawatt hours annually +which is I guess if that's enough for 16 + + align:start position:0% +which is I guess if that's enough for 16 + + + align:start position:0% +which is I guess if that's enough for 16 +000 European households for Turbine + + align:start position:0% +000 European households for Turbine + + + align:start position:0% +000 European households for Turbine +which I guess maybe by 8 000 American + + align:start position:0% +which I guess maybe by 8 000 American + + + align:start position:0% +which I guess maybe by 8 000 American +households the key point though is that + + align:start position:0% +households the key point though is that + + + align:start position:0% +households the key point though is that +how's the map I showed you before wind + + align:start position:0% +how's the map I showed you before wind + + + align:start position:0% +how's the map I showed you before wind +speeds are higher October the wind is + + align:start position:0% +speeds are higher October the wind is + + + align:start position:0% +speeds are higher October the wind is +steadier off the door if you put one of + + align:start position:0% +steadier off the door if you put one of + + + align:start position:0% +steadier off the door if you put one of +these turbines offshore it'll generate + + align:start position:0% +these turbines offshore it'll generate + + + align:start position:0% +these turbines offshore it'll generate +much more power than onshore provides + + align:start position:0% +much more power than onshore provides + + + align:start position:0% +much more power than onshore provides +but again we've yet to realize this + + align:start position:0% +but again we've yet to realize this + + + align:start position:0% +but again we've yet to realize this +technology American waters are deeper + + align:start position:0% +technology American waters are deeper + + + align:start position:0% +technology American waters are deeper +and stormier than European Waters + + align:start position:0% +and stormier than European Waters + + + align:start position:0% +and stormier than European Waters +Europeans I think have deployed some + + align:start position:0% +Europeans I think have deployed some + + + align:start position:0% +Europeans I think have deployed some +like five or six thousand offshore wind + + align:start position:0% +like five or six thousand offshore wind + + + align:start position:0% +like five or six thousand offshore wind +turbines we've only deployed seven of + + align:start position:0% +turbines we've only deployed seven of + + + align:start position:0% +turbines we've only deployed seven of +the us we have a lot of obstacles and + + align:start position:0% +the us we have a lot of obstacles and + + + align:start position:0% +the us we have a lot of obstacles and +bearish to overcome such as the right + + align:start position:0% +bearish to overcome such as the right + + + align:start position:0% +bearish to overcome such as the right +kinds of chips and the right kind of + + align:start position:0% +kinds of chips and the right kind of + + + align:start position:0% +kinds of chips and the right kind of +Workforce and the import capability that + + align:start position:0% +Workforce and the import capability that + + + align:start position:0% +Workforce and the import capability that +that are all necessary to build these + + align:start position:0% +that are all necessary to build these + + + align:start position:0% +that are all necessary to build these +offshore turbines let alone the undersea + + align:start position:0% +offshore turbines let alone the undersea + + + align:start position:0% +offshore turbines let alone the undersea +wiring required to transmit the powerful + + align:start position:0% +wiring required to transmit the powerful + + + align:start position:0% +wiring required to transmit the powerful +off your on to onshore and connected to + + align:start position:0% +off your on to onshore and connected to + + + align:start position:0% +off your on to onshore and connected to +our grid + + align:start position:0% + + + + align:start position:0% + +I'll skip over more GE marketing + + align:start position:0% +I'll skip over more GE marketing + + + align:start position:0% +I'll skip over more GE marketing +literature one key point or kind of + + align:start position:0% +literature one key point or kind of + + + align:start position:0% +literature one key point or kind of +analytical concept I want to talk to you + + align:start position:0% +analytical concept I want to talk to you + + + align:start position:0% +analytical concept I want to talk to you +about is the idea of intermittency + + align:start position:0% +about is the idea of intermittency + + + align:start position:0% +about is the idea of intermittency +you've probably heard that Renewable + + align:start position:0% +you've probably heard that Renewable + + + align:start position:0% +you've probably heard that Renewable +Energy Technologies are intermittent and + + align:start position:0% +Energy Technologies are intermittent and + + + align:start position:0% +Energy Technologies are intermittent and +that the wind doesn't always blow the + + align:start position:0% +that the wind doesn't always blow the + + + align:start position:0% +that the wind doesn't always blow the +sun doesn't always shine but what we use + + align:start position:0% +sun doesn't always shine but what we use + + + align:start position:0% +sun doesn't always shine but what we use +to measure the output of these + + align:start position:0% +to measure the output of these + + + align:start position:0% +to measure the output of these +technology is a calculation called the + + align:start position:0% +technology is a calculation called the + + + align:start position:0% +technology is a calculation called the +capacity Factor the asciate factor is + + align:start position:0% +capacity Factor the asciate factor is + + + align:start position:0% +capacity Factor the asciate factor is +defined as the ratio of actual power + + align:start position:0% +defined as the ratio of actual power + + + align:start position:0% +defined as the ratio of actual power +produced divided by the maximum possible + + align:start position:0% +produced divided by the maximum possible + + + align:start position:0% +produced divided by the maximum possible +power over a period of time + + align:start position:0% +power over a period of time + + + align:start position:0% +power over a period of time +so the key points I want to make is that + + align:start position:0% +so the key points I want to make is that + + + align:start position:0% +so the key points I want to make is that +it's unitless it's a percentage this is + + align:start position:0% +it's unitless it's a percentage this is + + + align:start position:0% +it's unitless it's a percentage this is +the number or percentage that's + + align:start position:0% +the number or percentage that's + + + align:start position:0% +the number or percentage that's +empirically determined in real life + + align:start position:0% +empirically determined in real life + + + align:start position:0% +empirically determined in real life +operation and it changes seasonally the + + align:start position:0% +operation and it changes seasonally the + + + align:start position:0% +operation and it changes seasonally the +wind blows differently in different + + align:start position:0% +wind blows differently in different + + + align:start position:0% +wind blows differently in different +places in the summer than the winter + + align:start position:0% +places in the summer than the winter + + + align:start position:0% +places in the summer than the winter +obviously uh it's determined real life + + align:start position:0% +obviously uh it's determined real life + + + align:start position:0% +obviously uh it's determined real life +operation uh seasonally solar operates + + align:start position:0% +operation uh seasonally solar operates + + + align:start position:0% +operation uh seasonally solar operates +as different intermittency or different + + align:start position:0% +as different intermittency or different + + + align:start position:0% +as different intermittency or different +capacity in different times of the year + + align:start position:0% +capacity in different times of the year + + + align:start position:0% +capacity in different times of the year +so we measure the capacity factor and we + + align:start position:0% +so we measure the capacity factor and we + + + align:start position:0% +so we measure the capacity factor and we +use capacity Factor as kind of a general + + align:start position:0% +use capacity Factor as kind of a general + + + align:start position:0% +use capacity Factor as kind of a general +ratio that we can use to calculate how + + align:start position:0% +ratio that we can use to calculate how + + + align:start position:0% +ratio that we can use to calculate how +much energy we're going to produce from + + align:start position:0% +much energy we're going to produce from + + + align:start position:0% +much energy we're going to produce from +a given technology given that the + + align:start position:0% +a given technology given that the + + + align:start position:0% +a given technology given that the +resource that is harvesting the wind or + + align:start position:0% +resource that is harvesting the wind or + + + align:start position:0% +resource that is harvesting the wind or +the sun are not necessarily always there + + align:start position:0% +the sun are not necessarily always there + + + align:start position:0% +the sun are not necessarily always there +so just to give you a few other kind of + + align:start position:0% +so just to give you a few other kind of + + + align:start position:0% +so just to give you a few other kind of +key terms the nameplate generation + + align:start position:0% +key terms the nameplate generation + + + align:start position:0% +key terms the nameplate generation +capacity this is what the general the + + align:start position:0% +capacity this is what the general the + + + align:start position:0% +capacity this is what the general the +manufacturer says the technology can + + align:start position:0% +manufacturer says the technology can + + + align:start position:0% +manufacturer says the technology can +generate that's what the GE diagram the + + align:start position:0% +generate that's what the GE diagram the + + + align:start position:0% +generate that's what the GE diagram the +previous few slides showed you that the + + align:start position:0% +previous few slides showed you that the + + + align:start position:0% +previous few slides showed you that the +nameplate generation capacity and the + + align:start position:0% +nameplate generation capacity and the + + + align:start position:0% +nameplate generation capacity and the +nameplate generation capacity varies for + + align:start position:0% +nameplate generation capacity varies for + + + align:start position:0% +nameplate generation capacity varies for +different Technologies just to show you + + align:start position:0% +different Technologies just to show you + + + align:start position:0% +different Technologies just to show you +a two fossil fuel Technologies a coal + + align:start position:0% +a two fossil fuel Technologies a coal + + + align:start position:0% +a two fossil fuel Technologies a coal +fire power plant or a natural gas + + align:start position:0% +fire power plant or a natural gas + + + align:start position:0% +fire power plant or a natural gas +turbine + + align:start position:0% +turbine + + + align:start position:0% +turbine +if we skip + + align:start position:0% +if we skip + + + align:start position:0% +if we skip +to + + align:start position:0% +to + + + align:start position:0% +to +the tables put out by the U.S Energy + + align:start position:0% +the tables put out by the U.S Energy + + + align:start position:0% +the tables put out by the U.S Energy +Information and administration when I + + align:start position:0% +Information and administration when I + + + align:start position:0% +Information and administration when I +clicked on the link from the slides for + + align:start position:0% +clicked on the link from the slides for + + + align:start position:0% +clicked on the link from the slides for +the eia tables from the electric power + + align:start position:0% +the eia tables from the electric power + + + align:start position:0% +the eia tables from the electric power +monthly what you're looking at here is a + + align:start position:0% +monthly what you're looking at here is a + + + align:start position:0% +monthly what you're looking at here is a +table of capacity factors for utility + + align:start position:0% +table of capacity factors for utility + + + align:start position:0% +table of capacity factors for utility +scale generators primarily using fossil + + align:start position:0% +scale generators primarily using fossil + + + align:start position:0% +scale generators primarily using fossil +fuels so just look at the uh kind of + + align:start position:0% +fuels so just look at the uh kind of + + + align:start position:0% +fuels so just look at the uh kind of +aspects of this table you have the + + align:start position:0% +aspects of this table you have the + + + align:start position:0% +aspects of this table you have the +annual data this is annualized data you + + align:start position:0% +annual data this is annualized data you + + + align:start position:0% +annual data this is annualized data you +have the various fossil fuel generating + + align:start position:0% +have the various fossil fuel generating + + + align:start position:0% +have the various fossil fuel generating +Technologies to pull natural gas natural + + align:start position:0% +Technologies to pull natural gas natural + + + align:start position:0% +Technologies to pull natural gas natural +gas is broken into combined cycle gas + + align:start position:0% +gas is broken into combined cycle gas + + + align:start position:0% +gas is broken into combined cycle gas +turbines and peaking gas turbines annual + + align:start position:0% +turbines and peaking gas turbines annual + + + align:start position:0% +turbines and peaking gas turbines annual +petroleum steam turbine gas turbine the + + align:start position:0% +petroleum steam turbine gas turbine the + + + align:start position:0% +petroleum steam turbine gas turbine the +internal combustion and so on these are + + align:start position:0% +internal combustion and so on these are + + + align:start position:0% +internal combustion and so on these are +all categorized in different ways but + + align:start position:0% +all categorized in different ways but + + + align:start position:0% +all categorized in different ways but +then the important thing to notice is + + align:start position:0% +then the important thing to notice is + + + align:start position:0% +then the important thing to notice is +that there's a Time adjust capacity it + + align:start position:0% +that there's a Time adjust capacity it + + + align:start position:0% +that there's a Time adjust capacity it +varies across years and here's the + + align:start position:0% +varies across years and here's the + + + align:start position:0% +varies across years and here's the +capacity factor it's a percentage of the + + align:start position:0% +capacity factor it's a percentage of the + + + align:start position:0% +capacity factor it's a percentage of the +time that the resource is actually + + align:start position:0% +time that the resource is actually + + + align:start position:0% +time that the resource is actually +producing power so you can see that coal + + align:start position:0% +producing power so you can see that coal + + + align:start position:0% +producing power so you can see that coal +has a relatively high capacity factor I + + align:start position:0% +has a relatively high capacity factor I + + + align:start position:0% +has a relatively high capacity factor I +guess around 50 or 6 60 percent but + + align:start position:0% +guess around 50 or 6 60 percent but + + + align:start position:0% +guess around 50 or 6 60 percent but +that's still much lower when we talk + + align:start position:0% +that's still much lower when we talk + + + align:start position:0% +that's still much lower when we talk +about coal as a base load resource a lot + + align:start position:0% +about coal as a base load resource a lot + + + align:start position:0% +about coal as a base load resource a lot +of Advocates will say well we need coal + + align:start position:0% +of Advocates will say well we need coal + + + align:start position:0% +of Advocates will say well we need coal +as a base load resource because it's + + align:start position:0% +as a base load resource because it's + + + align:start position:0% +as a base load resource because it's +always providing power + + align:start position:0% +always providing power + + + align:start position:0% +always providing power +so this has the factor could be + + align:start position:0% +so this has the factor could be + + + align:start position:0% +so this has the factor could be +relatively low at 56 50 or 60 percent of + + align:start position:0% +relatively low at 56 50 or 60 percent of + + + align:start position:0% +relatively low at 56 50 or 60 percent of +the time it's only providing resources + + align:start position:0% +the time it's only providing resources + + + align:start position:0% +the time it's only providing resources +or energy + + align:start position:0% +or energy + + + align:start position:0% +or energy +for a couple of different reasons it + + align:start position:0% +for a couple of different reasons it + + + align:start position:0% +for a couple of different reasons it +could be because it's uh coal power + + align:start position:0% +could be because it's uh coal power + + + align:start position:0% +could be because it's uh coal power +plants are actually frequently down for + + align:start position:0% +plants are actually frequently down for + + + align:start position:0% +plants are actually frequently down for +maintenance it could also be that cool + + align:start position:0% +maintenance it could also be that cool + + + align:start position:0% +maintenance it could also be that cool +fire power plants are simply out + + align:start position:0% +fire power plants are simply out + + + align:start position:0% +fire power plants are simply out +competed in certain seasons of the year + + align:start position:0% +competed in certain seasons of the year + + + align:start position:0% +competed in certain seasons of the year +for example if you look at the year 2020 + + align:start position:0% +for example if you look at the year 2020 + + + align:start position:0% +for example if you look at the year 2020 +you look at the capacity Factor + + align:start position:0% +you look at the capacity Factor + + + align:start position:0% +you look at the capacity Factor +coal-fired power plants look like they + + align:start position:0% +coal-fired power plants look like they + + + align:start position:0% +coal-fired power plants look like they +have a capacity Factor around 50 or 60 + + align:start position:0% +have a capacity Factor around 50 or 60 + + + align:start position:0% +have a capacity Factor around 50 or 60 +percent still in the summer because in + + align:start position:0% +percent still in the summer because in + + + align:start position:0% +percent still in the summer because in +July and August we have Peak electric + + align:start position:0% +July and August we have Peak electric + + + align:start position:0% +July and August we have Peak electric +demand but the capacity Factor gets as + + align:start position:0% +demand but the capacity Factor gets as + + + align:start position:0% +demand but the capacity Factor gets as +low as 25 or 30 percent for these kind + + align:start position:0% +low as 25 or 30 percent for these kind + + + align:start position:0% +low as 25 or 30 percent for these kind +of shoulder seasons and winter seasons + + align:start position:0% +of shoulder seasons and winter seasons + + + align:start position:0% +of shoulder seasons and winter seasons +probably because coal is simply not as + + align:start position:0% +probably because coal is simply not as + + + align:start position:0% +probably because coal is simply not as +necessary as for quote unquote base load + + align:start position:0% +necessary as for quote unquote base load + + + align:start position:0% +necessary as for quote unquote base load +power in those seasons of the year and + + align:start position:0% +power in those seasons of the year and + + + align:start position:0% +power in those seasons of the year and +it's probably being out competed by + + align:start position:0% +it's probably being out competed by + + + align:start position:0% +it's probably being out competed by +natural gas power plants + + align:start position:0% +natural gas power plants + + + align:start position:0% +natural gas power plants +if you look at combined cycle of gas + + align:start position:0% +if you look at combined cycle of gas + + + align:start position:0% +if you look at combined cycle of gas +turbines capacity Factor has been + + align:start position:0% +turbines capacity Factor has been + + + align:start position:0% +turbines capacity Factor has been +relatively steady over the previous + + align:start position:0% +relatively steady over the previous + + + align:start position:0% +relatively steady over the previous +years let's say around 50 to 60 percent + + align:start position:0% +years let's say around 50 to 60 percent + + + align:start position:0% +years let's say around 50 to 60 percent +and you can see again that they're much + + align:start position:0% +and you can see again that they're much + + + align:start position:0% +and you can see again that they're much +more utilized in the summer when we had + + align:start position:0% +more utilized in the summer when we had + + + align:start position:0% +more utilized in the summer when we had +electricity demand grain High because + + align:start position:0% +electricity demand grain High because + + + align:start position:0% +electricity demand grain High because +air conditioners but it's actually dips + + align:start position:0% +air conditioners but it's actually dips + + + align:start position:0% +air conditioners but it's actually dips +also in the uh kind of spring and fall + + align:start position:0% +also in the uh kind of spring and fall + + + align:start position:0% +also in the uh kind of spring and fall +simply because there's not as much + + align:start position:0% +simply because there's not as much + + + align:start position:0% +simply because there's not as much +electricity demand when it's not very + + align:start position:0% +electricity demand when it's not very + + + align:start position:0% +electricity demand when it's not very +hot or very cold if you look at another + + align:start position:0% +hot or very cold if you look at another + + + align:start position:0% +hot or very cold if you look at another +kind of gas turbine natural gas gas + + align:start position:0% +kind of gas turbine natural gas gas + + + align:start position:0% +kind of gas turbine natural gas gas +turbines these are probably peaking + + align:start position:0% +turbines these are probably peaking + + + align:start position:0% +turbines these are probably peaking +plants that are used to meet electricity + + align:start position:0% +plants that are used to meet electricity + + + align:start position:0% +plants that are used to meet electricity +demand for certain Peaks or for + + align:start position:0% +demand for certain Peaks or for + + + align:start position:0% +demand for certain Peaks or for +regulation of the grid keeping the Grid + + align:start position:0% +regulation of the grid keeping the Grid + + + align:start position:0% +regulation of the grid keeping the Grid +at the right frequency you can see that + + align:start position:0% +at the right frequency you can see that + + + align:start position:0% +at the right frequency you can see that +the demand utilization for these + + align:start position:0% +the demand utilization for these + + + align:start position:0% +the demand utilization for these +Technologies is relatively low it's like + + align:start position:0% +Technologies is relatively low it's like + + + align:start position:0% +Technologies is relatively low it's like +15 16 in July and August it dips as low + + align:start position:0% +15 16 in July and August it dips as low + + + align:start position:0% +15 16 in July and August it dips as low +as about nine or ten percent in the rest + + align:start position:0% +as about nine or ten percent in the rest + + + align:start position:0% +as about nine or ten percent in the rest +of the year simply because these + + align:start position:0% +of the year simply because these + + + align:start position:0% +of the year simply because these +turbines are mostly used to meet kind of + + align:start position:0% +turbines are mostly used to meet kind of + + + align:start position:0% +turbines are mostly used to meet kind of +the Peaks or the reserve or the + + align:start position:0% +the Peaks or the reserve or the + + + align:start position:0% +the Peaks or the reserve or the +regulation of the grid itself + + align:start position:0% +regulation of the grid itself + + + align:start position:0% +regulation of the grid itself +now I'm going to show you a different + + align:start position:0% +now I'm going to show you a different + + + align:start position:0% +now I'm going to show you a different +slide one moment + + align:start position:0% +slide one moment + + + align:start position:0% +slide one moment +if we go back to the slides the handout + + align:start position:0% +if we go back to the slides the handout + + + align:start position:0% +if we go back to the slides the handout +and I click on this table for electric + + align:start position:0% +and I click on this table for electric + + + align:start position:0% +and I click on this table for electric +power monthly table 6.07 B for + + align:start position:0% +power monthly table 6.07 B for + + + align:start position:0% +power monthly table 6.07 B for +non-fossil resources + + align:start position:0% + + + + align:start position:0% + +once you now see our capacity factors + + align:start position:0% +once you now see our capacity factors + + + align:start position:0% +once you now see our capacity factors +for utility scale generators primarily + + align:start position:0% +for utility scale generators primarily + + + align:start position:0% +for utility scale generators primarily +using non-fossil fuels so we should just + + align:start position:0% +using non-fossil fuels so we should just + + + align:start position:0% +using non-fossil fuels so we should just +note right off the bat this is for + + align:start position:0% +note right off the bat this is for + + + align:start position:0% +note right off the bat this is for +utility scale generators this is what + + align:start position:0% +utility scale generators this is what + + + align:start position:0% +utility scale generators this is what +the US to eia the Energy Information + + align:start position:0% +the US to eia the Energy Information + + + align:start position:0% +the US to eia the Energy Information +Administration collects this doesn't + + align:start position:0% +Administration collects this doesn't + + + align:start position:0% +Administration collects this doesn't +include necessarily a new out solar + + align:start position:0% +include necessarily a new out solar + + + align:start position:0% +include necessarily a new out solar +but if you look at the different types + + align:start position:0% +but if you look at the different types + + + align:start position:0% +but if you look at the different types +of Technologies geothermal hydroelectric + + align:start position:0% +of Technologies geothermal hydroelectric + + + align:start position:0% +of Technologies geothermal hydroelectric +nuclear biomass other kinds of gas solar + + align:start position:0% +nuclear biomass other kinds of gas solar + + + align:start position:0% +nuclear biomass other kinds of gas solar +photovoltaic and solar thermal and wind + + align:start position:0% +photovoltaic and solar thermal and wind + + + align:start position:0% +photovoltaic and solar thermal and wind +and wood these are kind of what I've + + align:start position:0% +and wood these are kind of what I've + + + align:start position:0% +and wood these are kind of what I've +refer to as a renewable toolkit if you + + align:start position:0% +refer to as a renewable toolkit if you + + + align:start position:0% +refer to as a renewable toolkit if you +look at the capacity factor for + + align:start position:0% +look at the capacity factor for + + + align:start position:0% +look at the capacity factor for +geothermal it's actually quite High + + align:start position:0% +geothermal it's actually quite High + + + align:start position:0% +geothermal it's actually quite High +looks around 70 percent geothermal + + align:start position:0% +looks around 70 percent geothermal + + + align:start position:0% +looks around 70 percent geothermal +because it comes from the heat from the + + align:start position:0% +because it comes from the heat from the + + + align:start position:0% +because it comes from the heat from the +earth is quite steady + + align:start position:0% +earth is quite steady + + + align:start position:0% +earth is quite steady +hydroelectric is actually a surprisingly + + align:start position:0% +hydroelectric is actually a surprisingly + + + align:start position:0% +hydroelectric is actually a surprisingly +low around 30 or 40 percent + + align:start position:0% +low around 30 or 40 percent + + + align:start position:0% +low around 30 or 40 percent +probably because hydroelectric + + align:start position:0% +probably because hydroelectric + + + align:start position:0% +probably because hydroelectric +Technologies often require water to be + + align:start position:0% +Technologies often require water to be + + + align:start position:0% +Technologies often require water to be +behind a reservoir and then it flows + + align:start position:0% +behind a reservoir and then it flows + + + align:start position:0% +behind a reservoir and then it flows +through a turbine and generates + + align:start position:0% +through a turbine and generates + + + align:start position:0% +through a turbine and generates +electricity so hydroelectric plants may + + align:start position:0% +electricity so hydroelectric plants may + + + align:start position:0% +electricity so hydroelectric plants may +not be run all a year or they may be + + align:start position:0% +not be run all a year or they may be + + + align:start position:0% +not be run all a year or they may be +around certain times of the year again + + align:start position:0% +around certain times of the year again + + + align:start position:0% +around certain times of the year again +let's say in July and August actually + + align:start position:0% +let's say in July and August actually + + + align:start position:0% +let's say in July and August actually +it's relatively low here but you might + + align:start position:0% +it's relatively low here but you might + + + align:start position:0% +it's relatively low here but you might +imagine + + align:start position:0% +imagine + + + align:start position:0% +imagine +um I'd love to power plants being run + + align:start position:0% +um I'd love to power plants being run + + + align:start position:0% +um I'd love to power plants being run +for various reasons in different times + + align:start position:0% +for various reasons in different times + + + align:start position:0% +for various reasons in different times +of the year for example where there's + + align:start position:0% +of the year for example where there's + + + align:start position:0% +of the year for example where there's +more spring runoff or snow melt in the + + align:start position:0% +more spring runoff or snow melt in the + + + align:start position:0% +more spring runoff or snow melt in the +spring it might actually have higher + + align:start position:0% +spring it might actually have higher + + + align:start position:0% +spring it might actually have higher +capacity factors + + align:start position:0% +capacity factors + + + align:start position:0% +capacity factors +nuclear power plants look like they have + + align:start position:0% +nuclear power plants look like they have + + + align:start position:0% +nuclear power plants look like they have +very high capacity factors around 90 and + + align:start position:0% +very high capacity factors around 90 and + + + align:start position:0% +very high capacity factors around 90 and +consistently + + align:start position:0% +consistently + + + align:start position:0% +consistently +and then solar portable take you can see + + align:start position:0% +and then solar portable take you can see + + + align:start position:0% +and then solar portable take you can see +only has a capacity factor of 25 over + + align:start position:0% +only has a capacity factor of 25 over + + + align:start position:0% +only has a capacity factor of 25 over +many years it doesn't seem to change a + + align:start position:0% +many years it doesn't seem to change a + + + align:start position:0% +many years it doesn't seem to change a +whole lot though you can tell in the 20 + + align:start position:0% +whole lot though you can tell in the 20 + + + align:start position:0% +whole lot though you can tell in the 20 +year 2020 it does change throughout the + + align:start position:0% +year 2020 it does change throughout the + + + align:start position:0% +year 2020 it does change throughout the +year because obviously in some parts of + + align:start position:0% +year because obviously in some parts of + + + align:start position:0% +year because obviously in some parts of +the year the days are longer notably + + align:start position:0% +the year the days are longer notably + + + align:start position:0% +the year the days are longer notably +summer than they are winter + + align:start position:0% +summer than they are winter + + + align:start position:0% +summer than they are winter +wind you can see that the capacity + + align:start position:0% +wind you can see that the capacity + + + align:start position:0% +wind you can see that the capacity +factors are around 30 35 over the years + + align:start position:0% +factors are around 30 35 over the years + + + align:start position:0% +factors are around 30 35 over the years +and you can actually see the capacity + + align:start position:0% +and you can actually see the capacity + + + align:start position:0% +and you can actually see the capacity +factors go down slightly in the summer + + align:start position:0% +factors go down slightly in the summer + + + align:start position:0% +factors go down slightly in the summer +that are slightly higher in the spring + + align:start position:0% +that are slightly higher in the spring + + + align:start position:0% +that are slightly higher in the spring +and the winter and the fall so this is + + align:start position:0% +and the winter and the fall so this is + + + align:start position:0% +and the winter and the fall so this is +just to give you a sense of even though + + align:start position:0% +just to give you a sense of even though + + + align:start position:0% +just to give you a sense of even though +certain technologies have a name plate + + align:start position:0% +certain technologies have a name plate + + + align:start position:0% +certain technologies have a name plate +capacity like GE Mark and Sarah Haley + + align:start position:0% +capacity like GE Mark and Sarah Haley + + + align:start position:0% +capacity like GE Mark and Sarah Haley +turbines it's not necessarily the energy + + align:start position:0% +turbines it's not necessarily the energy + + + align:start position:0% +turbines it's not necessarily the energy +or the electricity that we derive from + + align:start position:0% +or the electricity that we derive from + + + align:start position:0% +or the electricity that we derive from +these Technologies that's a percentage + + align:start position:0% +these Technologies that's a percentage + + + align:start position:0% +these Technologies that's a percentage +of the possible capacity + + align:start position:0% +of the possible capacity + + + align:start position:0% +of the possible capacity +so going back to our slides uh just to + + align:start position:0% +so going back to our slides uh just to + + + align:start position:0% +so going back to our slides uh just to +show you again the capacity Factor + + align:start position:0% +show you again the capacity Factor + + + align:start position:0% +show you again the capacity Factor +changes you can see that nuclear has + + align:start position:0% +changes you can see that nuclear has + + + align:start position:0% +changes you can see that nuclear has +relatively high capacity hydropower wind + + align:start position:0% +relatively high capacity hydropower wind + + + align:start position:0% +relatively high capacity hydropower wind +solar PV solar thermal all have lower + + align:start position:0% +solar PV solar thermal all have lower + + + align:start position:0% +solar PV solar thermal all have lower +capacity factors and of course our + + align:start position:0% +capacity factors and of course our + + + align:start position:0% +capacity factors and of course our +landfill gaps our biomass pole and + + align:start position:0% +landfill gaps our biomass pole and + + + align:start position:0% +landfill gaps our biomass pole and +natural gas power plants have higher + + align:start position:0% +natural gas power plants have higher + + + align:start position:0% +natural gas power plants have higher +capacity factors so the geothermal is + + align:start position:0% +capacity factors so the geothermal is + + + align:start position:0% +capacity factors so the geothermal is +also quite High a noticeable thing I + + align:start position:0% +also quite High a noticeable thing I + + + align:start position:0% +also quite High a noticeable thing I +want you to observe in this graph is + + align:start position:0% +want you to observe in this graph is + + + align:start position:0% +want you to observe in this graph is +that offshore wind has no capacity + + align:start position:0% +that offshore wind has no capacity + + + align:start position:0% +that offshore wind has no capacity +Factor because we haven't empirically + + align:start position:0% +Factor because we haven't empirically + + + align:start position:0% +Factor because we haven't empirically +determined it yet we haven't observed + + align:start position:0% +determined it yet we haven't observed + + + align:start position:0% +determined it yet we haven't observed +this technology in action as I said to + + align:start position:0% +this technology in action as I said to + + + align:start position:0% +this technology in action as I said to +you on the earlier slides there's only + + align:start position:0% +you on the earlier slides there's only + + + align:start position:0% +you on the earlier slides there's only +seven offshore wind turbines operating + + align:start position:0% +seven offshore wind turbines operating + + + align:start position:0% +seven offshore wind turbines operating +in the U.S even though we are planning + + align:start position:0% +in the U.S even though we are planning + + + align:start position:0% +in the U.S even though we are planning +to build about a hundred percent or a + + align:start position:0% +to build about a hundred percent or a + + + align:start position:0% +to build about a hundred percent or a +thousand times more offshore capacity at + + align:start position:0% +thousand times more offshore capacity at + + + align:start position:0% +thousand times more offshore capacity at +the moment it's a unproven technology + + align:start position:0% +the moment it's a unproven technology + + + align:start position:0% +the moment it's a unproven technology +that we still need to understand or the + + align:start position:0% +that we still need to understand or the + + + align:start position:0% +that we still need to understand or the +actual capacity is going to be so we can + + align:start position:0% +actual capacity is going to be so we can + + + align:start position:0% +actual capacity is going to be so we can +plan to build our grid or forecast how + + align:start position:0% +plan to build our grid or forecast how + + + align:start position:0% +plan to build our grid or forecast how +effective this technology is going to be + + align:start position:0% +effective this technology is going to be + + + align:start position:0% +effective this technology is going to be +in the future + + align:start position:0% +in the future + + + align:start position:0% +in the future +so another key metric for + + align:start position:0% +so another key metric for + + + align:start position:0% +so another key metric for +um this uh these costs of these + + align:start position:0% +um this uh these costs of these + + + align:start position:0% +um this uh these costs of these +Technologies is the levelized cost of + + align:start position:0% +Technologies is the levelized cost of + + + align:start position:0% +Technologies is the levelized cost of +energy in a simple way I'm just called + + align:start position:0% +energy in a simple way I'm just called + + + align:start position:0% +energy in a simple way I'm just called +here these simple levelized of + + align:start position:0% +here these simple levelized of + + + align:start position:0% +here these simple levelized of +energy it's taking the fixed cost + + align:start position:0% +energy it's taking the fixed cost + + + align:start position:0% +energy it's taking the fixed cost +the fuel costs and the variable + + align:start position:0% +the fuel costs and the variable + + + align:start position:0% +the fuel costs and the variable +operations maintenance and dividing it + + align:start position:0% +operations maintenance and dividing it + + + align:start position:0% +operations maintenance and dividing it +all or amortizing it over the length of + + align:start position:0% +all or amortizing it over the length of + + + align:start position:0% +all or amortizing it over the length of +Life the technology in other words + + align:start position:0% +Life the technology in other words + + + align:start position:0% +Life the technology in other words +taking the average cost of Technology + + align:start position:0% +taking the average cost of Technology + + + align:start position:0% +taking the average cost of Technology +averaged over its whole lifetime + + align:start position:0% +averaged over its whole lifetime + + + align:start position:0% +averaged over its whole lifetime +to show you in another way you have the + + align:start position:0% +to show you in another way you have the + + + align:start position:0% +to show you in another way you have the +capital cost times the recovery Factor + + align:start position:0% +capital cost times the recovery Factor + + + align:start position:0% +capital cost times the recovery Factor +plus the fixed cost this is the fixed + + align:start position:0% +plus the fixed cost this is the fixed + + + align:start position:0% +plus the fixed cost this is the fixed +cost term you divide it by 8 760 hours + + align:start position:0% +cost term you divide it by 8 760 hours + + + align:start position:0% +cost term you divide it by 8 760 hours +in a year and multiply comes the + + align:start position:0% +in a year and multiply comes the + + + align:start position:0% +in a year and multiply comes the +capacity Factor because you're not + + align:start position:0% +capacity Factor because you're not + + + align:start position:0% +capacity Factor because you're not +getting the full capacity of the + + align:start position:0% +getting the full capacity of the + + + align:start position:0% +getting the full capacity of the +technology all the time + + align:start position:0% +technology all the time + + + align:start position:0% +technology all the time +you can add on this additional fuel cost + + align:start position:0% +you can add on this additional fuel cost + + + align:start position:0% +you can add on this additional fuel cost +this is kind of the posture incurring + + align:start position:0% +this is kind of the posture incurring + + + align:start position:0% +this is kind of the posture incurring +throughout the life of the technology so + + align:start position:0% +throughout the life of the technology so + + + align:start position:0% +throughout the life of the technology so +you take the fuel cost to average over + + align:start position:0% +you take the fuel cost to average over + + + align:start position:0% +you take the fuel cost to average over +time and multiply times the speed rate + + align:start position:0% +time and multiply times the speed rate + + + align:start position:0% +time and multiply times the speed rate +which is the exact amount of energy + + align:start position:0% +which is the exact amount of energy + + + align:start position:0% +which is the exact amount of energy +you're actually getting out of the heat + + align:start position:0% +you're actually getting out of the heat + + + align:start position:0% +you're actually getting out of the heat +energy of the technology for example + + align:start position:0% +energy of the technology for example + + + align:start position:0% +energy of the technology for example +with a coal-fired power plant if it has + + align:start position:0% +with a coal-fired power plant if it has + + + align:start position:0% +with a coal-fired power plant if it has +a low heat rate around like 30 or 40 + + align:start position:0% +a low heat rate around like 30 or 40 + + + align:start position:0% +a low heat rate around like 30 or 40 +percent the heat of the technology may + + align:start position:0% +percent the heat of the technology may + + + align:start position:0% +percent the heat of the technology may +actually be going out the Smoke Stack + + align:start position:0% +actually be going out the Smoke Stack + + + align:start position:0% +actually be going out the Smoke Stack +and you wouldn't factor that into the + + align:start position:0% +and you wouldn't factor that into the + + + align:start position:0% +and you wouldn't factor that into the +energy of the fuel that you're getting + + align:start position:0% +energy of the fuel that you're getting + + + align:start position:0% +energy of the fuel that you're getting +and then you might add on some variable + + align:start position:0% +and then you might add on some variable + + + align:start position:0% +and then you might add on some variable +operations and maintenance costs I think + + align:start position:0% +operations and maintenance costs I think + + + align:start position:0% +operations and maintenance costs I think +a more exact way or better but more + + align:start position:0% +a more exact way or better but more + + + align:start position:0% +a more exact way or better but more +complicated formula + + align:start position:0% +complicated formula + + + align:start position:0% +complicated formula +for the level as constant energy + + align:start position:0% +for the level as constant energy + + + align:start position:0% +for the level as constant energy +Wikipedia actually has a surprisingly + + align:start position:0% +Wikipedia actually has a surprisingly + + + align:start position:0% +Wikipedia actually has a surprisingly +good article on this they call the + + align:start position:0% +good article on this they call the + + + align:start position:0% +good article on this they call the +levelized quantum energy be some of + + align:start position:0% +levelized quantum energy be some of + + + align:start position:0% +levelized quantum energy be some of +costs over the lifetime divided by the + + align:start position:0% +costs over the lifetime divided by the + + + align:start position:0% +costs over the lifetime divided by the +sum of electrical energy produced over + + align:start position:0% +sum of electrical energy produced over + + + align:start position:0% +sum of electrical energy produced over +the lifetime + + align:start position:0% +the lifetime + + + align:start position:0% +the lifetime +so you have various terms like the + + align:start position:0% +so you have various terms like the + + + align:start position:0% +so you have various terms like the +investment expenditures and year T + + align:start position:0% +investment expenditures and year T + + + align:start position:0% +investment expenditures and year T +that's this term here plus the + + align:start position:0% +that's this term here plus the + + + align:start position:0% +that's this term here plus the +operations and maintenance expenditures + + align:start position:0% +operations and maintenance expenditures + + + align:start position:0% +operations and maintenance expenditures +in year T that's the Mt here plus the + + align:start position:0% +in year T that's the Mt here plus the + + + align:start position:0% +in year T that's the Mt here plus the +fuel expenditures in the given year T + + align:start position:0% +fuel expenditures in the given year T + + + align:start position:0% +fuel expenditures in the given year T +here you add it up across all the years + + align:start position:0% +here you add it up across all the years + + + align:start position:0% +here you add it up across all the years +and starting at T equals one but the + + align:start position:0% +and starting at T equals one but the + + + align:start position:0% +and starting at T equals one but the +more complicated formula has a discount + + align:start position:0% +more complicated formula has a discount + + + align:start position:0% +more complicated formula has a discount +term 1 plus r over T where R is a + + align:start position:0% +term 1 plus r over T where R is a + + + align:start position:0% +term 1 plus r over T where R is a +discount rate that's a way of taking all + + align:start position:0% +discount rate that's a way of taking all + + + align:start position:0% +discount rate that's a way of taking all +the financial costs and discounting it + + align:start position:0% +the financial costs and discounting it + + + align:start position:0% +the financial costs and discounting it +over the discount rate + + align:start position:0% +over the discount rate + + + align:start position:0% +over the discount rate +and then what you do on the bottom is + + align:start position:0% +and then what you do on the bottom is + + + align:start position:0% +and then what you do on the bottom is +you have the energy so this is the cost + + align:start position:0% +you have the energy so this is the cost + + + align:start position:0% +you have the energy so this is the cost +per energy and you take all the energy + + align:start position:0% +per energy and you take all the energy + + + align:start position:0% +per energy and you take all the energy +over each of the periods T again sum it + + align:start position:0% +over each of the periods T again sum it + + + align:start position:0% +over each of the periods T again sum it +up over n terms and discount it so you + + align:start position:0% +up over n terms and discount it so you + + + align:start position:0% +up over n terms and discount it so you +discount it because the value of the + + align:start position:0% +discount it because the value of the + + + align:start position:0% +discount it because the value of the +energy or the cost Energy may not be the + + align:start position:0% +energy or the cost Energy may not be the + + + align:start position:0% +energy or the cost Energy may not be the +same the same in the future as it is now + + align:start position:0% +same the same in the future as it is now + + + align:start position:0% +same the same in the future as it is now +like the time value of money you're + + align:start position:0% +like the time value of money you're + + + align:start position:0% +like the time value of money you're +valuing the energy and the costs up + + align:start position:0% +valuing the energy and the costs up + + + align:start position:0% +valuing the energy and the costs up +front more than you are the energy and + + align:start position:0% +front more than you are the energy and + + + align:start position:0% +front more than you are the energy and +cost in the future + + align:start position:0% +cost in the future + + + align:start position:0% +cost in the future +and of course this note down here is + + align:start position:0% +and of course this note down here is + + + align:start position:0% +and of course this note down here is +useful some caution must be taken when + + align:start position:0% +useful some caution must be taken when + + + align:start position:0% +useful some caution must be taken when +using formulas for the levelized cost as + + align:start position:0% +using formulas for the levelized cost as + + + align:start position:0% +using formulas for the levelized cost as +they often embody unseen assumptions + + align:start position:0% +they often embody unseen assumptions + + + align:start position:0% +they often embody unseen assumptions +like neglecting the effects of cactus or + + align:start position:0% +like neglecting the effects of cactus or + + + align:start position:0% +like neglecting the effects of cactus or +maybe specified in real or nominal terms + + align:start position:0% +maybe specified in real or nominal terms + + + align:start position:0% +maybe specified in real or nominal terms +in other words other versions of the + + align:start position:0% +in other words other versions of the + + + align:start position:0% +in other words other versions of the +above formula like the previous slide do + + align:start position:0% +above formula like the previous slide do + + + align:start position:0% +above formula like the previous slide do +not discount the electricity stream in a + + align:start position:0% +not discount the electricity stream in a + + + align:start position:0% +not discount the electricity stream in a +way that the Wikipedia formula discounts + + align:start position:0% +way that the Wikipedia formula discounts + + + align:start position:0% +way that the Wikipedia formula discounts +it + + align:start position:0% +it + + + align:start position:0% +it +but this is uh why we look at the levard + + align:start position:0% +but this is uh why we look at the levard + + + align:start position:0% +but this is uh why we look at the levard +levelized cost of energy analysis I + + align:start position:0% +levelized cost of energy analysis I + + + align:start position:0% +levelized cost of energy analysis I +think all the assumptions are stated up + + align:start position:0% +think all the assumptions are stated up + + + align:start position:0% +think all the assumptions are stated up +front in the report this is a fairly + + align:start position:0% +front in the report this is a fairly + + + align:start position:0% +front in the report this is a fairly +industry standard report that gets + + align:start position:0% +industry standard report that gets + + + align:start position:0% +industry standard report that gets +supported every year last year it came + + align:start position:0% +supported every year last year it came + + + align:start position:0% +supported every year last year it came +out this week in October so we may get a + + align:start position:0% +out this week in October so we may get a + + + align:start position:0% +out this week in October so we may get a +new version this week you can see the + + align:start position:0% +new version this week you can see the + + + align:start position:0% +new version this week you can see the + Renewal Energy up here in the top + + align:start position:0% + Renewal Energy up here in the top + + + align:start position:0% + Renewal Energy up here in the top +boxes and the cost of conventional + + align:start position:0% +boxes and the cost of conventional + + + align:start position:0% +boxes and the cost of conventional +quote-unquote conventional or fossil + + align:start position:0% +quote-unquote conventional or fossil + + + align:start position:0% +quote-unquote conventional or fossil +fuel Technologies in the bottom and the + + align:start position:0% +fuel Technologies in the bottom and the + + + align:start position:0% +fuel Technologies in the bottom and the +reason why I say your renewable toolkit + + align:start position:0% +reason why I say your renewable toolkit + + + align:start position:0% +reason why I say your renewable toolkit +is getting cheaper and cleaner all the + + align:start position:0% +is getting cheaper and cleaner all the + + + align:start position:0% +is getting cheaper and cleaner all the +time look at the relative costs of + + align:start position:0% +time look at the relative costs of + + + align:start position:0% +time look at the relative costs of +feature Technologies solar PV uh on a + + align:start position:0% +feature Technologies solar PV uh on a + + + align:start position:0% +feature Technologies solar PV uh on a +cost in dollars of a megawatt hour is + + align:start position:0% +cost in dollars of a megawatt hour is + + + align:start position:0% +cost in dollars of a megawatt hour is +the same thing as the cost of cents per + + align:start position:0% +the same thing as the cost of cents per + + + align:start position:0% +the same thing as the cost of cents per +kilowatt hour that's 147 dollars per + + align:start position:0% +kilowatt hour that's 147 dollars per + + + align:start position:0% +kilowatt hour that's 147 dollars per +megawatt hour at least for solar Eevee + + align:start position:0% +megawatt hour at least for solar Eevee + + + align:start position:0% +megawatt hour at least for solar Eevee +in the rooftop residential but it's much + + align:start position:0% +in the rooftop residential but it's much + + + align:start position:0% +in the rooftop residential but it's much +cheaper for a commercial industrial + + align:start position:0% +cheaper for a commercial industrial + + + align:start position:0% +cheaper for a commercial industrial +rooftop installation it's actually about + + align:start position:0% +rooftop installation it's actually about + + + align:start position:0% +rooftop installation it's actually about +about 2.5 times less + + align:start position:0% +about 2.5 times less + + + align:start position:0% +about 2.5 times less +a solar PV and a community solar + + align:start position:0% +a solar PV and a community solar + + + align:start position:0% +a solar PV and a community solar +installation is even lower but not none + + align:start position:0% +installation is even lower but not none + + + align:start position:0% +installation is even lower but not none +of these other solar installations are + + align:start position:0% +of these other solar installations are + + + align:start position:0% +of these other solar installations are +as cheap as solar installed at the + + align:start position:0% +as cheap as solar installed at the + + + align:start position:0% +as cheap as solar installed at the +utility scale using different + + align:start position:0% +utility scale using different + + + align:start position:0% +utility scale using different +Technologies like crystalline + + align:start position:0% +Technologies like crystalline + + + align:start position:0% +Technologies like crystalline +photovoltaic panels or thin film + + align:start position:0% +photovoltaic panels or thin film + + + align:start position:0% +photovoltaic panels or thin film +photovoltaic panels + + align:start position:0% +photovoltaic panels + + + align:start position:0% +photovoltaic panels +if you look at solar Thermal Tower + + align:start position:0% +if you look at solar Thermal Tower + + + align:start position:0% +if you look at solar Thermal Tower +that's also called a concentrating solar + + align:start position:0% +that's also called a concentrating solar + + + align:start position:0% +that's also called a concentrating solar +tower this is like out in the desert in + + align:start position:0% +tower this is like out in the desert in + + + align:start position:0% +tower this is like out in the desert in +California this is still relatively + + align:start position:0% +California this is still relatively + + + align:start position:0% +California this is still relatively +expensive and has not gotten cheaper + + align:start position:0% +expensive and has not gotten cheaper + + + align:start position:0% +expensive and has not gotten cheaper +over time solar PV is the technology + + align:start position:0% +over time solar PV is the technology + + + align:start position:0% +over time solar PV is the technology +that's gotten cheapest most quickly + + align:start position:0% +that's gotten cheapest most quickly + + + align:start position:0% +that's gotten cheapest most quickly +we'll talk more about that in the next + + align:start position:0% +we'll talk more about that in the next + + + align:start position:0% +we'll talk more about that in the next +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +geothermal is relatively cheap + + align:start position:0% +geothermal is relatively cheap + + + align:start position:0% +geothermal is relatively cheap +but it's also important to note in the + + align:start position:0% +but it's also important to note in the + + + align:start position:0% +but it's also important to note in the +context of this class that wind is the + + align:start position:0% +context of this class that wind is the + + + align:start position:0% +context of this class that wind is the +cheapest resource among the renewable + + align:start position:0% +cheapest resource among the renewable + + + align:start position:0% +cheapest resource among the renewable +Technologies it's at least at lowest + + align:start position:0% +Technologies it's at least at lowest + + + align:start position:0% +Technologies it's at least at lowest +point twenty six dollars per megawatt + + align:start position:0% +point twenty six dollars per megawatt + + + align:start position:0% +point twenty six dollars per megawatt +hour that can vary and be as much as + + align:start position:0% +hour that can vary and be as much as + + + align:start position:0% +hour that can vary and be as much as +fifty dollars per megawatt hour probably + + align:start position:0% +fifty dollars per megawatt hour probably + + + align:start position:0% +fifty dollars per megawatt hour probably +for older wind farm that has smaller + + align:start position:0% +for older wind farm that has smaller + + + align:start position:0% +for older wind farm that has smaller +wind turbines now the important thing to + + align:start position:0% +wind turbines now the important thing to + + + align:start position:0% +wind turbines now the important thing to +note is that wind at 26 dollars per + + align:start position:0% +note is that wind at 26 dollars per + + + align:start position:0% +note is that wind at 26 dollars per +megawatt hour on the low end of the + + align:start position:0% +megawatt hour on the low end of the + + + align:start position:0% +megawatt hour on the low end of the +scale is actually much cheaper than our + + align:start position:0% +scale is actually much cheaper than our + + + align:start position:0% +scale is actually much cheaper than our +other technology it's cheaper than a gas + + align:start position:0% +other technology it's cheaper than a gas + + + align:start position:0% +other technology it's cheaper than a gas +peaking natural gas plant it's much + + align:start position:0% +peaking natural gas plant it's much + + + align:start position:0% +peaking natural gas plant it's much +cheaper than a nuclear power plant it's + + align:start position:0% +cheaper than a nuclear power plant it's + + + align:start position:0% +cheaper than a nuclear power plant it's +cheaper than a coal fire power plant and + + align:start position:0% +cheaper than a coal fire power plant and + + + align:start position:0% +cheaper than a coal fire power plant and +it's basically cheaper than a combined + + align:start position:0% +it's basically cheaper than a combined + + + align:start position:0% +it's basically cheaper than a combined +gas cycle turbine power plant + + align:start position:0% +gas cycle turbine power plant + + + align:start position:0% +gas cycle turbine power plant +if we look at that the sensitivity of + + align:start position:0% +if we look at that the sensitivity of + + + align:start position:0% +if we look at that the sensitivity of +these various costs to federal tax + + align:start position:0% +these various costs to federal tax + + + align:start position:0% +these various costs to federal tax +subsidies have been levelized costs + + align:start position:0% +subsidies have been levelized costs + + + align:start position:0% +subsidies have been levelized costs +estimates from Ozark really include + + align:start position:0% +estimates from Ozark really include + + + align:start position:0% +estimates from Ozark really include +federal tax subsidies and public + + align:start position:0% +federal tax subsidies and public + + + align:start position:0% +federal tax subsidies and public +calculations you can see that federal + + align:start position:0% +calculations you can see that federal + + + align:start position:0% +calculations you can see that federal +tax deficitors make solar PV have the + + align:start position:0% +tax deficitors make solar PV have the + + + align:start position:0% +tax deficitors make solar PV have the +rooftop cheaper and make solar PV on the + + align:start position:0% +rooftop cheaper and make solar PV on the + + + align:start position:0% +rooftop cheaper and make solar PV on the +commercial industrial buildings keeper + + align:start position:0% +commercial industrial buildings keeper + + + align:start position:0% +commercial industrial buildings keeper +it makes Community solar cheaper it + + align:start position:0% +it makes Community solar cheaper it + + + align:start position:0% +it makes Community solar cheaper it +makes utility scale Cheaper by about 25 + + align:start position:0% +makes utility scale Cheaper by about 25 + + + align:start position:0% +makes utility scale Cheaper by about 25 +30 percent + + align:start position:0% +30 percent + + + align:start position:0% +30 percent +makes solar thermal Towers cheaper it + + align:start position:0% +makes solar thermal Towers cheaper it + + + align:start position:0% +makes solar thermal Towers cheaper it +makes geothermal Technologies cheaper + + align:start position:0% +makes geothermal Technologies cheaper + + + align:start position:0% +makes geothermal Technologies cheaper +and it makes wind much much cheaper at + + align:start position:0% +and it makes wind much much cheaper at + + + align:start position:0% +and it makes wind much much cheaper at +the low end from 26 megawatt hour we + + align:start position:0% +the low end from 26 megawatt hour we + + + align:start position:0% +the low end from 26 megawatt hour we +went to nine dollars per megawatt hour + + align:start position:0% +went to nine dollars per megawatt hour + + + align:start position:0% +went to nine dollars per megawatt hour +if you compare that to all these + + align:start position:0% +if you compare that to all these + + + align:start position:0% +if you compare that to all these +conventional or fossil Technologies in + + align:start position:0% +conventional or fossil Technologies in + + + align:start position:0% +conventional or fossil Technologies in +the previous slide and none of these + + align:start position:0% +the previous slide and none of these + + + align:start position:0% +the previous slide and none of these +things compete because we don't offer as + + align:start position:0% +things compete because we don't offer as + + + align:start position:0% +things compete because we don't offer as +many overt federal tax subsidies for + + align:start position:0% +many overt federal tax subsidies for + + + align:start position:0% +many overt federal tax subsidies for +these Technologies in terms of energy + + align:start position:0% +these Technologies in terms of energy + + + align:start position:0% +these Technologies in terms of energy +production even though these + + align:start position:0% +production even though these + + + align:start position:0% +production even though these +Technologies or these industries do + + align:start position:0% +Technologies or these industries do + + + align:start position:0% +Technologies or these industries do +receive a lot of subsidies in other ways + + align:start position:0% +receive a lot of subsidies in other ways + + + align:start position:0% +receive a lot of subsidies in other ways +but Lazar doesn't calculate those + + align:start position:0% +but Lazar doesn't calculate those + + + align:start position:0% +but Lazar doesn't calculate those +levelized costs just to show the + + align:start position:0% +levelized costs just to show the + + + align:start position:0% +levelized costs just to show the +sensitivity of this because the federal + + align:start position:0% +sensitivity of this because the federal + + + align:start position:0% +sensitivity of this because the federal +tax subsidy for renewable energy have + + align:start position:0% +tax subsidy for renewable energy have + + + align:start position:0% +tax subsidy for renewable energy have +been much more debated and are frankly + + align:start position:0% +been much more debated and are frankly + + + align:start position:0% +been much more debated and are frankly +sometimes a little less secure or less + + align:start position:0% +sometimes a little less secure or less + + + align:start position:0% +sometimes a little less secure or less +entrenched than the fossil fuel + + align:start position:0% +entrenched than the fossil fuel + + + align:start position:0% +entrenched than the fossil fuel +subsidies + + align:start position:0% +subsidies + + + align:start position:0% +subsidies +but if we do this comparison again the + + align:start position:0% +but if we do this comparison again the + + + align:start position:0% +but if we do this comparison again the +key point from a lot of energy analysts + + align:start position:0% +key point from a lot of energy analysts + + + align:start position:0% +key point from a lot of energy analysts +and a lot of renewable energy Advocates + + align:start position:0% +and a lot of renewable energy Advocates + + + align:start position:0% +and a lot of renewable energy Advocates +is that if you compare the levelized + + align:start position:0% +is that if you compare the levelized + + + align:start position:0% +is that if you compare the levelized +cost of new build wind and solar versus + + align:start position:0% +cost of new build wind and solar versus + + + align:start position:0% +cost of new build wind and solar versus +the marginal cost of selected existing + + align:start position:0% +the marginal cost of selected existing + + + align:start position:0% +the marginal cost of selected existing +conventional generation in other words + + align:start position:0% +conventional generation in other words + + + align:start position:0% +conventional generation in other words +the right hand side here for coal + + align:start position:0% +the right hand side here for coal + + + align:start position:0% +the right hand side here for coal +nuclear and combined and gas cycle + + align:start position:0% +nuclear and combined and gas cycle + + + align:start position:0% +nuclear and combined and gas cycle +turbines we already have that fossil + + align:start position:0% +turbines we already have that fossil + + + align:start position:0% +turbines we already have that fossil +fuel system and it's already built or + + align:start position:0% +fuel system and it's already built or + + + align:start position:0% +fuel system and it's already built or +private compare is should we continue to + + align:start position:0% +private compare is should we continue to + + + align:start position:0% +private compare is should we continue to +operate the fossil fuel system that we + + align:start position:0% +operate the fossil fuel system that we + + + align:start position:0% +operate the fossil fuel system that we +have or should we new build wind and + + align:start position:0% +have or should we new build wind and + + + align:start position:0% +have or should we new build wind and +solar and so the point of this graph is + + align:start position:0% +solar and so the point of this graph is + + + align:start position:0% +solar and so the point of this graph is +to show that onshore wind if you + + align:start position:0% +to show that onshore wind if you + + + align:start position:0% +to show that onshore wind if you +subsidize it it's cheaper to build a + + align:start position:0% +subsidize it it's cheaper to build a + + + align:start position:0% +subsidize it it's cheaper to build a +whole new onshore wind turbine or farm + + align:start position:0% +whole new onshore wind turbine or farm + + + align:start position:0% +whole new onshore wind turbine or farm +and provide Power that way subsidized + + align:start position:0% +and provide Power that way subsidized + + + align:start position:0% +and provide Power that way subsidized +wind out competes all these fossil + + align:start position:0% +wind out competes all these fossil + + + align:start position:0% +wind out competes all these fossil +generation Technologies and unsubsidized + + align:start position:0% +generation Technologies and unsubsidized + + + align:start position:0% +generation Technologies and unsubsidized +solar PV unsubsidized wind and + + align:start position:0% +solar PV unsubsidized wind and + + + align:start position:0% +solar PV unsubsidized wind and +subsidized solar PV are getting to the + + align:start position:0% +subsidized solar PV are getting to the + + + align:start position:0% +subsidized solar PV are getting to the +point where they're starting to + + align:start position:0% +point where they're starting to + + + align:start position:0% +point where they're starting to +outcompete coal and nuclear and will + + align:start position:0% +outcompete coal and nuclear and will + + + align:start position:0% +outcompete coal and nuclear and will +probably soon algae outcompete gas and + + align:start position:0% +probably soon algae outcompete gas and + + + align:start position:0% +probably soon algae outcompete gas and +combined vehicle with combines that gold + + align:start position:0% +combined vehicle with combines that gold + + + align:start position:0% +combined vehicle with combines that gold +gas turbines also thank you very much \ No newline at end of file diff --git a/JGCSdBMU1uA.txt b/JGCSdBMU1uA.txt new file mode 100644 index 0000000000000000000000000000000000000000..b05f507e763fdffaf5c23c0d5b170d86a5bc0532 --- /dev/null +++ b/JGCSdBMU1uA.txt @@ -0,0 +1,746 @@ +Sarah Hansen: +Today on the podcast, we're highlighting the + +power of open educational resources or OER. + +Elizabeth Siler: +I love using OER. + +One thing I love about teaching OER is that +I get to teach what I want to teach. + +What I think my students need to know, in +the way they need to learn it. + +Instead of just defaulting to what the textbooks +say. + +Sarah Hansen: +In this episode, I invited two instructors + +in to talk about open educational resources. + +One of them teaches negotiation and management +here at MIT and shares her course materials + +in MIT OpenCourseWare. + +The other recently adapted those materials +for use in her own course at another university. + +An organizational ombudsperson at MIT for +42 years, adjunct professor Mary Rowe was + +among the very first instructors to put her +course materials on OpenCourseWare almost + +20 years ago. + +That course is titled 15.667, Negotiation +and Conflict Management. + +Associate professor Elizabeth Siler has used +and adapted the materials from this course + +inner teachings at Worcester State University. + +When we brought these two instructors together, +something really special happened while much + +of the conversation did center on negotiation +itself. + +Mary and Elizabeth simultaneously began a +real time collaboration about how to teach + +negotiation with OER from Mary's course. + +Sarah Hansen: +The conversation brought forward so much of + +what we at OCW hope OER can do for educators. + +Things like creating community, shared ownership +of learning materials and fuel for inspired + +teaching, that we just really wanted to share +it with you. + +We hope it will help you find new inspiration +for using OER in your teaching. + +So without any further ado, let's jump into +the conversation. + +You'll hear me talking with Elizabeth first +and we start with one of my own insecurities + +about negotiation, an anxiety some of you +may share. + +When I think about negotiation, I like freeze +up. + +I'm like, Oh God, I have to negotiate a salary. + +I'm never going to get what I want. + +I can't ask for what I want. + +Elizabeth Siler: +Well, that's one of the reasons that I really + +like this course learning it and teaching +it. + +It's one of the things that... + +This is probably true for most students and +most people, they don't really like to deal + +with conflict, but learning about negotiation +as a way that you can learn that there are + +different ways to handle a conflict, or handle +a negotiation without changing your personality, + +right. + +Without being something that you're not. + +It's their skills and their behaviors, but +they're not personality traits. + +You can be shy and still be clear in what +you want and ask questions. + +You can still be a successful negotiator and +still not like speaking in public. + +Mary Rowe: +I think that's a wonderful example of how + +negotiation specialists try to build options, +which is that those who get into negotiations + +about anything, including bedtime for children, +want to come up with options. + +Sarah Hansen: +I'm taking that to heart as I think about + +my three-year-old tonight. + +So the course 15.667, the one we have on MIT, +OpenCourseWare it involves a number of case + +studies and simulations, which you've made +openly available Mary to the world. + +Tell us about the role of case studies in +the course? + +Mary Rowe: +So case studies and discussing real life is + +how you learn negotiations. + +It's absolutely essential. + +Elizabeth Siler: +There's one of them called dealing with an + +aggressive competitive negotiator. + +And this was a case, the main character's +named Mr. Canny. + +And he just wants what you're selling, but +he won't admit it and he won't give in. + +He won't, he keeps asking for more and it, +I mean, he's a real pain. + +But what I love about this is that the students +read this and they're like, "Oh, what do I + +do this person? + +How do I deal with this person? + +What's going on?" + +And then they talk about it with each other +and they start to see that, okay, there are + +some things we could do. + +And then we start to apply that process of, +well, what are his interests? + +What does he want? + +What's going on behind the scenes? + +Elizabeth Siler: +He's being very aggressive, but why is that? + +And what does he like? + +How might you talk to this person, so +he'll be more likely to take you seriously. + +And so the two things I like about this is, +one is that the teaching notes for some of + +these are really thorough and lovely and wonderful, +is this list that's like two pages long of + +things that you could do to address this situation. + +But the other thing about it is that this +is written so strongly that my students had + +some really visceral reactions to this. + +Some of them felt really angry. + +We did this at the end of the class, the end +of the semester, so that they were comfortable + +talking about... + +They were more comfortable with self disclosure +about how they were feeling and what went + +on. + +And some of them got really angry. + +Some of them got really scared. + +I was thrilled when this very articulate, +very kind of cool hockey player guy in my + +class said, "I'll admit it. + +You know, I was a little nervous when I was +reading this." + +Like, yes. + +Okay, good. + +Elizabeth Siler: +And so they could talk about how you have + +to deal with your own emotions right before +you can go on and negotiate, which in business, + +so much... emotions are treated like they are +bad, or that people don't have emotions. + +But you can't really negotiate well if you're +afraid. + +Or you can't negotiate well with somebody +if you're angry. + +So one of the things we talked about at the +end is, okay, here's how you felt about this. + +What are some things that you do? + +I mean, there was money involved in it, but +the thing that was really important about + +that one to me was to get the students to +acknowledge their emotions and figure out + +how to deal with them. + +And then to see that there's a whole lot more +things they could do in the situation than + +they thought of, than they had thought about +before. + +Mary Rowe: +It's hard to imagine, Elizabeth, more skillful + +discussion of teaching that case. + +Listening to you, I notice two things. + +One of them is that you've illuminated perfectly, +that we're all negotiating with ourselves + +and how we're dealing with our negotiation, +with our, our dealing, with our emotions. + +We've got two different points of view. + +I've got to make this work and I'm panicked +or I'm furious. + +So you're opening up a discussion at the end +of the class about even not just how I noticed + +that negotiations are important, I guess they +should have been. + +My first point is that emotions are important +that after all relationships between people, + +are almost always the most important thing +going on, even more so than money. + +But secondly, that in dealing with my emotions, +that I might be negotiating with myself, I + +loved your description. + +Elizabeth Siler: +And I love how you could tie that back to + +the theory. + +Right? + +negotiating with yourself because... + +Well, that's, frankly, that's one of the hardest +things I find about teaching is until I really, + +really know, like until I've taught the course +a lot or really know it, it takes me longer + +to make those connections from the student +experience to the theory. + +So it's really helpful to see that. + +Mary Rowe: +Well, and it's helpful to me to listen to + +you and see it. + +So always learning. + +Listening to Elizabeth again now reminded +me of how every student who plays has a chance + +to learn their own strengths and their own +vulnerabilities. + +And I think that could be elucidated better +in the teaching. + +I used to say at the beginning of the course, +that I have no idea whether we can teach people + +to negotiate better in the sense of getting +more of what you want. + +I was pretty sure that we can teach how you +and your team can lose less in working with + +other people. + +I'd like to think more about that in revising +the course. + +Mary Rowe: +We, haven't actually proven that we can teach + +people to negotiate better, in part because +how well you negotiate is for you to decide. + +And I can't tell you how you would think of +it. + +You might watch me negotiate and think I'd +given up the store and I'm pretty happy about + +it because I've maintained the relationships +that mattered to me. + +But I think we can teach people to defend +themselves better and that we can prove that. + +Anyway, you're right on the fringe know of +what I've been thinking about. + +Sarah Hansen: +The case studies and 15.667 are designed for + +graduate students in the MIT Sloan School +of Management. + +And many of these students come to the course +with previous management and business experience. + +Elizabeth Siler: +My students have not had the same kinds of + +work experience that a graduate student would +have. + +So I would add some things in to explain, +well, this is how a law firm works, or this + +is what a defense contractor does. + +And this is the way the organization is structured. + +So when you say this, this is what it means. + +It, when it says this, this is what it means. + +And it was just really helpful because that's +the stuff that they would need to know to + +make a decision, but they don't need to know +it to learn how to negotiate. + +I try to get the confusing things out of the +way so they can concentrate on what are the + +interests, and what am I going to say? + +Mary Rowe: +Very good ideas. + +Sarah Hansen: +It seems like you're touching on an important + +aspect of what it means to teach with OER. + +What it means to really discover something +and then to change it, to make it work for + +your students. + +Elizabeth Siler: +Yeah. + +I love using OER. + +One thing I love about teaching OER is that +I get to teach what I want to teach. + +What I think my students need to know in the +way they need to learn it. + +Instead of just defaulting to what the texts +books say. + +And sometimes that means using a textbook +that's an open resource and just adding things + +in. + +Sometimes it means pulling from more than +one textbook. + +Sometimes it means pulling things from... + +Writing things and pulling in podcasts and +articles and- + +Mary Rowe: +And the newspaper from yesterday. + +Elizabeth Siler: +... Newspaper from yesterday. + +Right. + +Sarah Hansen: +I asked Elizabeth if she had any tips for + +educators who wanted to begin teaching with +OER. + +Elizabeth Siler: +The first thing I would do is to talk to your + +librarian, because librarians are pretty much +at the forefront of open education resources. + +The next thing I would say is to find somebody +to work with find some community, which is, + +Mary's nodding. + +It's a lot easier if you were starting a course +kind of from scratch the way I was with this + +course to find somebody to work with, because +it helps split up the workload and it gives + +you somebody to bounce ideas off of. + +And the other thing is just to think about +what's working and what's not working about + +your current course. + +Because if something's not working, you can +probably find something else to replace it. + +It's not just about using a textbook that's +free, so that your students will have it. + +It's also about being able to teach what you +think they need to learn. + +Elizabeth Siler: +The other thing is, if you're using open educational + +resources that you can mix and match. + +There are several meta search engines for +OER materials right now. + +And the good news is the bad news that there +are so many of them, you might have to dig + +through to find what you're looking for. + +But the good news is that there is a lot out +there. + +And if there's not, then you can write it. + +Sarah Hansen: +Elizabeth, what plans do you have to share + +the materials you've adapted from Mary's course +with others? + +Elizabeth Siler: +Right. + +That's part of open education resources overall +is community again, and it's doing what you + +have and sharing it with other people. + +Once I finish, I'm probably going to work +with the instructional designer at my school, + +actually to put things in a word document +and PDF documents. + +So that they could be in a format that can +be easily adapted by other professors and + +then find a platform for it. + +Sarah Hansen: +Before we ended our conversation, I asked + +Mary and Elizabeth, if there was anything +else, they wanted to ask each other about + +teaching with the OER in 15.667. + +Mary Rowe: + +Well I would like to ask, Elizabeth, did you +use the task of writing a perceived injurious + +experience letter? + +Elizabeth Siler: +Oh, yes I did. + +Mary Rowe: +The reason I ask is that of everything that + +I ever stumbled into, of course, everything +you've heard from me is hindsight. + +I never had the wit to plan it, but of everything +that I ever came up with in teaching negotiations, + +the perceived injurious letter and various +variations of it, flew by far the furthest. + +I would get requests, I remember one from +Canada to reproduce the instructions in 500,000 + +copies for school, for elementary school or +something. + +And still on my website at Sloan, it's now +called ideas to consider if you've been harassed, + +right. + +But basically the notion of how to deal with +a situation where you have felt injured or + +hurt. + +So I'm very interested in your experience +with it. + +Elizabeth Siler: +Yeah. + +From one of the last assignments in this semester, +the students could write the perceived injurious- + +Mary Rowe: +Experience. + +Elizabeth Siler: +... experience, right. + +They could write a PIE letter or they could +write an apology letter. + +They could choose, and they could write about +something from themselves and their own life. + +Or they could write about something from one +of the cases, because not everybody has the + +same level of comfort and disclosing and that's +fine. + +They can still learn. + +And what I found out was, first of all I was +really surprised still, even with being around + +hundreds of undergraduates every day, just +how much, how personal people were willing + +to get at this. + +I mean, it was clear I was the only person +who was going to read this. + +Nobody was ever going to do it. + +They didn't have to send it. + +But people got really personal and I thought +they would be getting personal more about + +how they'd been injured, but they got really +personal and really explicit and really thoughtful + +about how they had hurt other people. + +Elizabeth Siler: +And that was really powerful. + +I mean, I was kind of blown away by how willing +they were to take this on and the things they + +said. + +And I wish I had done it earlier in the semester +so that I could find out some more, how did + +they react to that? + +Like what did they get out of it? + +Going back to the beginning of this, I think +that maybe why this spoke to me so much, it's + +because it was everything every day. + +And that there are a lot of things you can +do in business classes with a very low amount + +of emotions involved, and that's great, but +this isn't one of them. + +And we don't really talk about it much in +any other business classes, but we're human. + +As my finance professor said, Annabel Burrell. + +And she said, we are more than rational beings. + +Right? + +And I think this is one of the places where +that's incredibly clear. + +Mary Rowe: +You remind me also that it's the basis for + +leadership. + +To the extent that management training includes +a discussion of leadership, emotions had relationships + +are profoundly fundamental. + +Sarah Hansen: +You two have completely changed my perspective + +on what negotiation is. + +I feel like you've created a pathway for me +to explore this area more. + +I feel like it's accessible to me that I might +actually be good at it. + +Mary Rowe: +Oh, yeah. + +Sarah Hansen: +That I might be doing it already without knowing + +it. + +If you're getting the same feeling that maybe +you or your students might already be, or + +it could become good at negotiation with the +right tools, and want to learn more, you can + +explore, download, reuse, and remix all of +Mary's teaching materials from our MIT OpenCourseWare + +website. + +On our website and in the show notes, you'll +find the case study about dealing with an + +aggressive competitive negotiator, like Mr. +Canny and guidelines for writing a perceived + +injurious experience letter. + +If you, like Elizabeth use these or other +OER from OpenCourseWare in your teaching, + +we'd love to hear about it because when you +share your story of using OER, you inspire + +others. + +And that's what we're all about. + +Thank you for listening. + +And we hope you enjoyed season one of Chalk +Radio. + +We're already hard at work on season two. + +If there's a professor you'd like to hear +from reach out and let us know. + +Until next time I'm Sarah Hansen from MIT, +OpenCourseWare. \ No newline at end of file diff --git a/JPkgJwJHYSc.txt b/JPkgJwJHYSc.txt new file mode 100644 index 0000000000000000000000000000000000000000..b555856f942314437efd56c3c248d9b804e6ad77 --- /dev/null +++ b/JPkgJwJHYSc.txt @@ -0,0 +1,14603 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +I'm excited because I'm gonna get the + + align:start position:0% +I'm excited because I'm gonna get the + + + align:start position:0% +I'm excited because I'm gonna get the +chance to co-teach today with I would + + align:start position:0% +chance to co-teach today with I would + + + align:start position:0% +chance to co-teach today with I would +say one of the students but it's not + + align:start position:0% +say one of the students but it's not + + + align:start position:0% +say one of the students but it's not +really one of the students but Larry + + align:start position:0% +really one of the students but Larry + + + align:start position:0% +really one of the students but Larry +Lessig is consented to join us in a in a + + align:start position:0% +Lessig is consented to join us in a in a + + + align:start position:0% +Lessig is consented to join us in a in a +few minutes so I'm going to be breezing + + align:start position:0% +few minutes so I'm going to be breezing + + + align:start position:0% +few minutes so I'm going to be breezing +through a little faster than usual and + + align:start position:0% +through a little faster than usual and + + + align:start position:0% +through a little faster than usual and +then we'll co-teach this blockchain and + + align:start position:0% +then we'll co-teach this blockchain and + + + align:start position:0% +then we'll co-teach this blockchain and +money here we are where it's smart + + align:start position:0% +money here we are where it's smart + + + align:start position:0% +money here we are where it's smart +contracts everybody seems to be coming + + align:start position:0% +contracts everybody seems to be coming + + + align:start position:0% +contracts everybody seems to be coming +back which is a sign of your interest + + align:start position:0% +back which is a sign of your interest + + + align:start position:0% +back which is a sign of your interest +more than it is in my teaching but I + + align:start position:0% +more than it is in my teaching but I + + + align:start position:0% +more than it is in my teaching but I +thank you for being here + + align:start position:0% +thank you for being here + + + align:start position:0% +thank you for being here +we made it through the last three + + align:start position:0% +we made it through the last three + + + align:start position:0% +we made it through the last three +classes together on Bitcoin in the + + align:start position:0% +classes together on Bitcoin in the + + + align:start position:0% +classes together on Bitcoin in the +basics of that technology and in one + + align:start position:0% +basics of that technology and in one + + + align:start position:0% +basics of that technology and in one +class we're gonna try to chew off a bit + + align:start position:0% +class we're gonna try to chew off a bit + + + align:start position:0% +class we're gonna try to chew off a bit +on smart contracts both the technology + + align:start position:0% +on smart contracts both the technology + + + align:start position:0% +on smart contracts both the technology +side a little bit on the market and then + + align:start position:0% +side a little bit on the market and then + + + align:start position:0% +side a little bit on the market and then +the law that Larry is going to take us + + align:start position:0% +the law that Larry is going to take us + + + align:start position:0% +the law that Larry is going to take us +through and so as I said I want to start + + align:start position:0% +through and so as I said I want to start + + + align:start position:0% +through and so as I said I want to start +with a little administrative because we + + align:start position:0% +with a little administrative because we + + + align:start position:0% +with a little administrative because we +are on the sixth class I'm gonna review + + align:start position:0% +are on the sixth class I'm gonna review + + + align:start position:0% +are on the sixth class I'm gonna review +a bit about the projects very quickly + + align:start position:0% +a bit about the projects very quickly + + + align:start position:0% +a bit about the projects very quickly +we're gonna do smart contracts the the + + align:start position:0% +we're gonna do smart contracts the the + + + align:start position:0% +we're gonna do smart contracts the the +design what what design features yes + + align:start position:0% +design what what design features yes + + + align:start position:0% +design what what design features yes +we're gonna go back a little bit about + + align:start position:0% +we're gonna go back a little bit about + + + align:start position:0% +we're gonna go back a little bit about +hash functions and Merkle trees but not + + align:start position:0% +hash functions and Merkle trees but not + + + align:start position:0% +hash functions and Merkle trees but not +too much + + align:start position:0% +too much + + + align:start position:0% +too much +DAP switch are basically decentralized + + align:start position:0% +DAP switch are basically decentralized + + + align:start position:0% +DAP switch are basically decentralized +applications and token sales Larry's + + align:start position:0% +applications and token sales Larry's + + + align:start position:0% +applications and token sales Larry's +going to take us through legal issues + + align:start position:0% +going to take us through legal issues + + + align:start position:0% +going to take us through legal issues +and then we'll sum it all up so let me + + align:start position:0% +and then we'll sum it all up so let me + + + align:start position:0% +and then we'll sum it all up so let me +just real fast on the administrative + + align:start position:0% +just real fast on the administrative + + + align:start position:0% +just real fast on the administrative +side again class participation 30% + + align:start position:0% +side again class participation 30% + + + align:start position:0% +side again class participation 30% +that's why we're all here together + + align:start position:0% +that's why we're all here together + + + align:start position:0% +that's why we're all here together +that means hopefully reading the + + align:start position:0% +that means hopefully reading the + + + align:start position:0% +that means hopefully reading the +assignments and participating about half + + align:start position:0% +assignments and participating about half + + + align:start position:0% +assignments and participating about half +of you have participated so I guess I'm + + align:start position:0% +of you have participated so I guess I'm + + + align:start position:0% +of you have participated so I guess I'm +gonna go with a little bit more cold + + align:start position:0% +gonna go with a little bit more cold + + + align:start position:0% +gonna go with a little bit more cold +calling starting Thursday I'm not gonna + + align:start position:0% +calling starting Thursday I'm not gonna + + + align:start position:0% +calling starting Thursday I'm not gonna +do a bunch of it today because Larry and + + align:start position:0% +do a bunch of it today because Larry and + + + align:start position:0% +do a bunch of it today because Larry and +I are joining so you can ease off but be + + align:start position:0% +I are joining so you can ease off but be + + + align:start position:0% +I are joining so you can ease off but be +really be conscious if you haven't been + + align:start position:0% +really be conscious if you haven't been + + + align:start position:0% +really be conscious if you haven't been +participating try to get in and join the + + align:start position:0% +participating try to get in and join the + + + align:start position:0% +participating try to get in and join the +conversation and discussion the two + + align:start position:0% +conversation and discussion the two + + + align:start position:0% +conversation and discussion the two +individual write-ups I think we have + + align:start position:0% +individual write-ups I think we have + + + align:start position:0% +individual write-ups I think we have +seven but it's quite possible some of + + align:start position:0% +seven but it's quite possible some of + + + align:start position:0% +seven but it's quite possible some of +you have submitted already it's just + + align:start position:0% +you have submitted already it's just + + + align:start position:0% +you have submitted already it's just +meant to be + + align:start position:0% +meant to be + + + align:start position:0% +meant to be +critical business reasoning we are in a + + align:start position:0% +critical business reasoning we are in a + + + align:start position:0% +critical business reasoning we are in a +business school mcc's tenth you just + + align:start position:0% +business school mcc's tenth you just + + + align:start position:0% +business school mcc's tenth you just +summarized some readings I'm sure will + + align:start position:0% +summarized some readings I'm sure will + + + align:start position:0% +summarized some readings I'm sure will +give you a you know a pass on that but + + align:start position:0% +give you a you know a pass on that but + + + align:start position:0% +give you a you know a pass on that but +that's not what I'm looking for I'm + + align:start position:0% +that's not what I'm looking for I'm + + + align:start position:0% +that's not what I'm looking for I'm +really looking for critical reasoning + + align:start position:0% +really looking for critical reasoning + + + align:start position:0% +really looking for critical reasoning +and thinking from a business perspective + + align:start position:0% +and thinking from a business perspective + + + align:start position:0% +and thinking from a business perspective +of why does this matter what are its + + align:start position:0% +of why does this matter what are its + + + align:start position:0% +of why does this matter what are its +strengths or its values in terms of + + align:start position:0% +strengths or its values in terms of + + + align:start position:0% +strengths or its values in terms of +business reasoning and critical + + align:start position:0% +business reasoning and critical + + + align:start position:0% +business reasoning and critical +reasoning one by the tenth class one by + + align:start position:0% +reasoning one by the tenth class one by + + + align:start position:0% +reasoning one by the tenth class one by +the 23rd always before class what it + + align:start position:0% +the 23rd always before class what it + + + align:start position:0% +the 23rd always before class what it +likely means this will be getting most + + align:start position:0% +likely means this will be getting most + + + align:start position:0% +likely means this will be getting most +of these on the 8th 9th and 10th class I + + align:start position:0% +of these on the 8th 9th and 10th class I + + + align:start position:0% +of these on the 8th 9th and 10th class I +know how that works and so forth and + + align:start position:0% +know how that works and so forth and + + + align:start position:0% +know how that works and so forth and +that's okay that's okay + + align:start position:0% +that's okay that's okay + + + align:start position:0% +that's okay that's okay +but I'm just reminding you of that in + + align:start position:0% +but I'm just reminding you of that in + + + align:start position:0% +but I'm just reminding you of that in +terms of the group research paper again + + align:start position:0% +terms of the group research paper again + + + align:start position:0% +terms of the group research paper again +Sabrina and talita stood up a Google app + + align:start position:0% +Sabrina and talita stood up a Google app + + + align:start position:0% +Sabrina and talita stood up a Google app +I think it's in Google but where you can + + align:start position:0% +I think it's in Google but where you can + + + align:start position:0% +I think it's in Google but where you can +go in and team up in teams of three or + + align:start position:0% +go in and team up in teams of three or + + + align:start position:0% +go in and team up in teams of three or +four it's not required to do this by the + + align:start position:0% +four it's not required to do this by the + + + align:start position:0% +four it's not required to do this by the +eighth class next Tuesday but I'm + + align:start position:0% +eighth class next Tuesday but I'm + + + align:start position:0% +eighth class next Tuesday but I'm +strongly suggesting it to figure out who + + align:start position:0% +strongly suggesting it to figure out who + + + align:start position:0% +strongly suggesting it to figure out who +your teams are and not sort of wait till + + align:start position:0% +your teams are and not sort of wait till + + + align:start position:0% +your teams are and not sort of wait till +the second half of the semester and I'd + + align:start position:0% +the second half of the semester and I'd + + + align:start position:0% +the second half of the semester and I'd +like to encourage everybody to choose an + + align:start position:0% +like to encourage everybody to choose an + + + align:start position:0% +like to encourage everybody to choose an +area for your use case by mid way again + + align:start position:0% +area for your use case by mid way again + + + align:start position:0% +area for your use case by mid way again +you're not going to get graded if it + + align:start position:0% +you're not going to get graded if it + + + align:start position:0% +you're not going to get graded if it +takes you another class or two to figure + + align:start position:0% +takes you another class or two to figure + + + align:start position:0% +takes you another class or two to figure +it out but I just think it's much better + + align:start position:0% +it out but I just think it's much better + + + align:start position:0% +it out but I just think it's much better +if you you know your teams you know what + + align:start position:0% +if you you know your teams you know what + + + align:start position:0% +if you you know your teams you know what +your use case will be if it's not about + + align:start position:0% +your use case will be if it's not about + + + align:start position:0% +your use case will be if it's not about +finance one one group was already asked + + align:start position:0% +finance one one group was already asked + + + align:start position:0% +finance one one group was already asked +me to if that's all right I just want to + + align:start position:0% +me to if that's all right I just want to + + + align:start position:0% +me to if that's all right I just want to +know more detailed what its gonna be I'm + + align:start position:0% +know more detailed what its gonna be I'm + + + align:start position:0% +know more detailed what its gonna be I'm +probably gonna say yes but it needs a + + align:start position:0% +probably gonna say yes but it needs a + + + align:start position:0% +probably gonna say yes but it needs a +little bit of pre-approval if it's + + align:start position:0% +little bit of pre-approval if it's + + + align:start position:0% +little bit of pre-approval if it's +outside of Finance so any questions + + align:start position:0% +outside of Finance so any questions + + + align:start position:0% +outside of Finance so any questions +about the requirements I just wanted a + + align:start position:0% + + + + align:start position:0% + +so the study questions today's smart + + align:start position:0% +so the study questions today's smart + + + align:start position:0% +so the study questions today's smart +contracts and and basically how they + + align:start position:0% +contracts and and basically how they + + + align:start position:0% +contracts and and basically how they +compared to regular contracts and what + + align:start position:0% +compared to regular contracts and what + + + align:start position:0% +compared to regular contracts and what +are the tokens that are used within that + + align:start position:0% +are the tokens that are used within that + + + align:start position:0% +are the tokens that are used within that +ecosystem and what are the platforms in + + align:start position:0% +ecosystem and what are the platforms in + + + align:start position:0% +ecosystem and what are the platforms in +a very similar sense to + + align:start position:0% +a very similar sense to + + + align:start position:0% +a very similar sense to +the Internet we have the Internet and + + align:start position:0% +the Internet we have the Internet and + + + align:start position:0% +the Internet we have the Internet and +then above the internet you have you + + align:start position:0% +then above the internet you have you + + + align:start position:0% +then above the internet you have you +would say applications Facebook and + + align:start position:0% +would say applications Facebook and + + + align:start position:0% +would say applications Facebook and +other applications well this too has a + + align:start position:0% +other applications well this too has a + + + align:start position:0% +other applications well this too has a +series of platforms and then + + align:start position:0% +series of platforms and then + + + align:start position:0% +series of platforms and then +decentralized applications potentially + + align:start position:0% +decentralized applications potentially + + + align:start position:0% +decentralized applications potentially +on top of that and basically a quick + + align:start position:0% +on top of that and basically a quick + + + align:start position:0% +on top of that and basically a quick +touch on decentralized applications + + align:start position:0% +touch on decentralized applications + + + align:start position:0% +touch on decentralized applications +later in the semester we're going to + + align:start position:0% +later in the semester we're going to + + + align:start position:0% +later in the semester we're going to +take two sessions on initial point + + align:start position:0% +take two sessions on initial point + + + align:start position:0% +take two sessions on initial point +offerings and thus we're going to talk a + + align:start position:0% +offerings and thus we're going to talk a + + + align:start position:0% +offerings and thus we're going to talk a +lot about token economics so this will + + align:start position:0% +lot about token economics so this will + + + align:start position:0% +lot about token economics so this will +be just the first taste test and then + + align:start position:0% +be just the first taste test and then + + + align:start position:0% +be just the first taste test and then +we'll come back to it later and then the + + align:start position:0% +we'll come back to it later and then the + + + align:start position:0% +we'll come back to it later and then the +readings I hopefully everybody read + + align:start position:0% +readings I hopefully everybody read + + + align:start position:0% +readings I hopefully everybody read +through smart contracts + + align:start position:0% +through smart contracts + + + align:start position:0% +through smart contracts +I thought the chamber of digital + + align:start position:0% +I thought the chamber of digital + + + align:start position:0% +I thought the chamber of digital +commerce even though this is almost two + + align:start position:0% +commerce even though this is almost two + + + align:start position:0% +commerce even though this is almost two +years ago this paper was a very helpful + + align:start position:0% +years ago this paper was a very helpful + + + align:start position:0% +years ago this paper was a very helpful +sort of flavor for what folks and + + align:start position:0% +sort of flavor for what folks and + + + align:start position:0% +sort of flavor for what folks and +commerce are thinking and what + + align:start position:0% +commerce are thinking and what + + + align:start position:0% +commerce are thinking and what +developers were thinking and I love that + + align:start position:0% +developers were thinking and I love that + + + align:start position:0% +developers were thinking and I love that +nick szabo sort of wrote the + + align:start position:0% +nick szabo sort of wrote the + + + align:start position:0% +nick szabo sort of wrote the +introduction to it and and and it's + + align:start position:0% +introduction to it and and and it's + + + align:start position:0% +introduction to it and and and it's +interesting to see in question why is it + + align:start position:0% +interesting to see in question why is it + + + align:start position:0% +interesting to see in question why is it +that it's two years later and many of + + align:start position:0% +that it's two years later and many of + + + align:start position:0% +that it's two years later and many of +those use cases are still being + + align:start position:0% +those use cases are still being + + + align:start position:0% +those use cases are still being +discussed but haven't fully been adopted + + align:start position:0% +discussed but haven't fully been adopted + + + align:start position:0% +discussed but haven't fully been adopted +and then the state of the daps and and + + align:start position:0% +and then the state of the daps and and + + + align:start position:0% +and then the state of the daps and and +then who are the competitors to eat + + align:start position:0% +then who are the competitors to eat + + + align:start position:0% +then who are the competitors to eat +theorem so you don't you feel good I + + align:start position:0% +theorem so you don't you feel good I + + + align:start position:0% +theorem so you don't you feel good I +haven't asked anybody a cold question + + align:start position:0% +haven't asked anybody a cold question + + + align:start position:0% +haven't asked anybody a cold question +yet and then the optional readings I + + align:start position:0% +yet and then the optional readings I + + + align:start position:0% +yet and then the optional readings I +don't know did anybody actually go back + + align:start position:0% +don't know did anybody actually go back + + + align:start position:0% +don't know did anybody actually go back +there optional did anybody go back and + + align:start position:0% +there optional did anybody go back and + + + align:start position:0% +there optional did anybody go back and +read either Sabo's original piece from + + align:start position:0% +read either Sabo's original piece from + + + align:start position:0% +read either Sabo's original piece from +20 years ago in smart contracts so few + + align:start position:0% +20 years ago in smart contracts so few + + + align:start position:0% +20 years ago in smart contracts so few +of you are kind of into that rabbit hole + + align:start position:0% +of you are kind of into that rabbit hole + + + align:start position:0% +of you are kind of into that rabbit hole +of blocks ay and an ether British what + + align:start position:0% +of blocks ay and an ether British what + + + align:start position:0% +of blocks ay and an ether British what +did you think of you know it's 20 years + + align:start position:0% +did you think of you know it's 20 years + + + align:start position:0% +did you think of you know it's 20 years +ago he wrote this thing on nick szabo + + align:start position:0% +ago he wrote this thing on nick szabo + + + align:start position:0% +ago he wrote this thing on nick szabo +wrote this think about the etherium + + align:start position:0% +wrote this think about the etherium + + + align:start position:0% +wrote this think about the etherium +white paper what's interesting is even + + align:start position:0% +white paper what's interesting is even + + + align:start position:0% +white paper what's interesting is even +if you didn't do it for the class and + + align:start position:0% +if you didn't do it for the class and + + + align:start position:0% +if you didn't do it for the class and +you find yourself more and more + + align:start position:0% +you find yourself more and more + + + align:start position:0% +you find yourself more and more +interested in this over the next couple + + align:start position:0% +interested in this over the next couple + + + align:start position:0% +interested in this over the next couple +of months or even later going back and + + align:start position:0% +of months or even later going back and + + + align:start position:0% +of months or even later going back and +read + + align:start position:0% +read + + + align:start position:0% +read +the etherium white paper it's not highly + + align:start position:0% +the etherium white paper it's not highly + + + align:start position:0% +the etherium white paper it's not highly +technical in the first I don't know 10 + + align:start position:0% +technical in the first I don't know 10 + + + align:start position:0% +technical in the first I don't know 10 +or 15 pages it really gives a history of + + align:start position:0% +or 15 pages it really gives a history of + + + align:start position:0% +or 15 pages it really gives a history of +Bitcoin it talks about distributed + + align:start position:0% +Bitcoin it talks about distributed + + + align:start position:0% +Bitcoin it talks about distributed +applications and largely written at the + + align:start position:0% +applications and largely written at the + + + align:start position:0% +applications and largely written at the +time by a nineteen year old as well so + + align:start position:0% +time by a nineteen year old as well so + + + align:start position:0% +time by a nineteen year old as well so +it's it's a remarkable thing and then + + align:start position:0% +it's it's a remarkable thing and then + + + align:start position:0% +it's it's a remarkable thing and then +one of Larry's colleague or maybe it's + + align:start position:0% +one of Larry's colleague or maybe it's + + + align:start position:0% +one of Larry's colleague or maybe it's +two of them but deep philippi paper as + + align:start position:0% +two of them but deep philippi paper as + + + align:start position:0% +two of them but deep philippi paper as +well on the regulatory issues so let me + + align:start position:0% +well on the regulatory issues so let me + + + align:start position:0% +well on the regulatory issues so let me +talk a little bit about smart contracts + + align:start position:0% +talk a little bit about smart contracts + + + align:start position:0% +talk a little bit about smart contracts +and lay a groundwork before Larry gives + + align:start position:0% +and lay a groundwork before Larry gives + + + align:start position:0% +and lay a groundwork before Larry gives +us the law a smart contract is a set of + + align:start position:0% +us the law a smart contract is a set of + + + align:start position:0% +us the law a smart contract is a set of +promises specified in a digital form I'm + + align:start position:0% +promises specified in a digital form I'm + + + align:start position:0% +promises specified in a digital form I'm +gonna say four things it's just a set of + + align:start position:0% +gonna say four things it's just a set of + + + align:start position:0% +gonna say four things it's just a set of +promises and in digital form so it's not + + align:start position:0% +promises and in digital form so it's not + + + align:start position:0% +promises and in digital form so it's not +hand written out it includes protocols + + align:start position:0% +hand written out it includes protocols + + + align:start position:0% +hand written out it includes protocols +what's a protocol andrew operating + + align:start position:0% +what's a protocol andrew operating + + + align:start position:0% +what's a protocol andrew operating +procedure is anybody else give me + + align:start position:0% +procedure is anybody else give me + + + align:start position:0% +procedure is anybody else give me +another word for it maybe an algorithm + + align:start position:0% +another word for it maybe an algorithm + + + align:start position:0% +another word for it maybe an algorithm +so so a set of promises in digital form + + align:start position:0% +so so a set of promises in digital form + + + align:start position:0% +so so a set of promises in digital form +but it can include math basically if you + + align:start position:0% +but it can include math basically if you + + + align:start position:0% +but it can include math basically if you +wish or standard operating procedures + + align:start position:0% +wish or standard operating procedures + + + align:start position:0% +wish or standard operating procedures +if-then statements and so forth and it's + + align:start position:0% +if-then statements and so forth and it's + + + align:start position:0% +if-then statements and so forth and it's +innate the parties then perform against + + align:start position:0% +innate the parties then perform against + + + align:start position:0% +innate the parties then perform against +these promises and guess what nick szabo + + align:start position:0% +these promises and guess what nick szabo + + + align:start position:0% +these promises and guess what nick szabo +wrote that in 1996 and i thought it was + + align:start position:0% +wrote that in 1996 and i thought it was + + + align:start position:0% +wrote that in 1996 and i thought it was +still probably the best definition of + + align:start position:0% +still probably the best definition of + + + align:start position:0% +still probably the best definition of +smart contract he coined the phrase 22 + + align:start position:0% +smart contract he coined the phrase 22 + + + align:start position:0% +smart contract he coined the phrase 22 +years ago he might actually be Satoshi + + align:start position:0% +years ago he might actually be Satoshi + + + align:start position:0% +years ago he might actually be Satoshi +Nakamoto three of the tables in here you + + align:start position:0% +Nakamoto three of the tables in here you + + + align:start position:0% +Nakamoto three of the tables in here you +all voted that it was Nick's mo so I + + align:start position:0% +all voted that it was Nick's mo so I + + + align:start position:0% +all voted that it was Nick's mo so I +thought that's kind of the best + + align:start position:0% +thought that's kind of the best + + + align:start position:0% +thought that's kind of the best +definition if you've got to just kind of + + align:start position:0% +definition if you've got to just kind of + + + align:start position:0% +definition if you've got to just kind of +a root you know now I would also say + + align:start position:0% +a root you know now I would also say + + + align:start position:0% +a root you know now I would also say +however that smart contracts may not be + + align:start position:0% +however that smart contracts may not be + + + align:start position:0% +however that smart contracts may not be +so smart a lot of people have come to be + + align:start position:0% +so smart a lot of people have come to be + + + align:start position:0% +so smart a lot of people have come to be +calling them dumb contracts they're just + + align:start position:0% +calling them dumb contracts they're just + + + align:start position:0% +calling them dumb contracts they're just +algorithms that perform a function so + + align:start position:0% +algorithms that perform a function so + + + align:start position:0% +algorithms that perform a function so +don't think of them as artificial + + align:start position:0% +don't think of them as artificial + + + align:start position:0% +don't think of them as artificial +intelligence that's another class + + align:start position:0% +intelligence that's another class + + + align:start position:0% +intelligence that's another class +provided next semester by Simon Johnson + + align:start position:0% +provided next semester by Simon Johnson + + + align:start position:0% +provided next semester by Simon Johnson +think of them almost as just dumb + + align:start position:0% +think of them almost as just dumb + + + align:start position:0% +think of them almost as just dumb +contracts and in a sense they're + + align:start position:0% +contracts and in a sense they're + + + align:start position:0% +contracts and in a sense they're +mechanizing what might otherwise be done + + align:start position:0% +mechanizing what might otherwise be done + + + align:start position:0% +mechanizing what might otherwise be done +amongst them between humans and smart + + align:start position:0% +amongst them between humans and smart + + + align:start position:0% +amongst them between humans and smart +contracts may or may not be really + + align:start position:0% +contracts may or may not be really + + + align:start position:0% +contracts may or may not be really +contracts and that's why Larry is going + + align:start position:0% +contracts and that's why Larry is going + + + align:start position:0% +contracts and that's why Larry is going +to speak to it so I just remember even + + align:start position:0% +to speak to it so I just remember even + + + align:start position:0% +to speak to it so I just remember even +though Nick Sabo's calls it smart + + align:start position:0% +though Nick Sabo's calls it smart + + + align:start position:0% +though Nick Sabo's calls it smart +contracts they may not be smart and they + + align:start position:0% +contracts they may not be smart and they + + + align:start position:0% +contracts they may not be smart and they +may not be contracts so a little bit + + align:start position:0% +may not be contracts so a little bit + + + align:start position:0% +may not be contracts so a little bit +about the technical features remember + + align:start position:0% +about the technical features remember + + + align:start position:0% +about the technical features remember +our three three ways we did this what + + align:start position:0% +our three three ways we did this what + + + align:start position:0% +our three three ways we did this what +what are the big technical features that + + align:start position:0% +what are the big technical features that + + + align:start position:0% +what are the big technical features that +we studied I'm sorry to do this Anton + + align:start position:0% +we studied I'm sorry to do this Anton + + + align:start position:0% +we studied I'm sorry to do this Anton +what are the three big buckets remember + + align:start position:0% +what are the three big buckets remember + + + align:start position:0% +what are the three big buckets remember +we took three classes and three buckets + + align:start position:0% +we took three classes and three buckets + + + align:start position:0% +we took three classes and three buckets +of information great you got what two + + align:start position:0% +of information great you got what two + + + align:start position:0% +of information great you got what two +other people give me the others so + + align:start position:0% +other people give me the others so + + + align:start position:0% +other people give me the others so +cryptography guess what bitcoin and + + align:start position:0% +cryptography guess what bitcoin and + + + align:start position:0% +cryptography guess what bitcoin and +etherium all have the same cryptography + + align:start position:0% +etherium all have the same cryptography + + + align:start position:0% +etherium all have the same cryptography +it's not identical but for the purposes + + align:start position:0% +it's not identical but for the purposes + + + align:start position:0% +it's not identical but for the purposes +of design features it has cryptographic + + align:start position:0% +of design features it has cryptographic + + + align:start position:0% +of design features it has cryptographic +hashes timestamps block headers Merkle + + align:start position:0% +hashes timestamps block headers Merkle + + + align:start position:0% +hashes timestamps block headers Merkle +trees the etherium has more than one + + align:start position:0% +trees the etherium has more than one + + + align:start position:0% +trees the etherium has more than one +Merkel tree and Bitcoin has one and it + + align:start position:0% +Merkel tree and Bitcoin has one and it + + + align:start position:0% +Merkel tree and Bitcoin has one and it +has digital signatures and addresses so + + align:start position:0% +has digital signatures and addresses so + + + align:start position:0% +has digital signatures and addresses so +everything we talked about three + + align:start position:0% +everything we talked about three + + + align:start position:0% +everything we talked about three +lectures ago about cryptography both + + align:start position:0% +lectures ago about cryptography both + + + align:start position:0% +lectures ago about cryptography both +forms of block chains anybody want to + + align:start position:0% +forms of block chains anybody want to + + + align:start position:0% +forms of block chains anybody want to +give me what our second bucket was + + align:start position:0% + + + + align:start position:0% + +Jeremy's centralization what else did we + + align:start position:0% +Jeremy's centralization what else did we + + + align:start position:0% +Jeremy's centralization what else did we +talk about Elan consensus so again + + align:start position:0% +talk about Elan consensus so again + + + align:start position:0% +talk about Elan consensus so again +decentralized network consensus if + + align:start position:0% +decentralized network consensus if + + + align:start position:0% +decentralized network consensus if +theorem actually uses proof of work even + + align:start position:0% +theorem actually uses proof of work even + + + align:start position:0% +theorem actually uses proof of work even +though that some there's some talk that + + align:start position:0% +though that some there's some talk that + + + align:start position:0% +though that some there's some talk that +ether will move to proof of stake but + + align:start position:0% +ether will move to proof of stake but + + + align:start position:0% +ether will move to proof of stake but +it's currently proof of work there's a + + align:start position:0% +it's currently proof of work there's a + + + align:start position:0% +it's currently proof of work there's a +native currency it's eath or F or ETH or + + align:start position:0% +native currency it's eath or F or ETH or + + + align:start position:0% +native currency it's eath or F or ETH or +ether instead of Bitcoin + + align:start position:0% +ether instead of Bitcoin + + + align:start position:0% +ether instead of Bitcoin +and it has a network the third thing + + align:start position:0% +and it has a network the third thing + + + align:start position:0% +and it has a network the third thing +that we talked about transaction format + + align:start position:0% +that we talked about transaction format + + + align:start position:0% +that we talked about transaction format +so we talked about transactions and + + align:start position:0% +so we talked about transactions and + + + align:start position:0% +so we talked about transactions and +script well guess what a theorem does + + align:start position:0% +script well guess what a theorem does + + + align:start position:0% +script well guess what a theorem does +not have a transaction script or aut XO + + align:start position:0% +not have a transaction script or aut XO + + + align:start position:0% +not have a transaction script or aut XO +so that's the one place that Vitalik + + align:start position:0% +so that's the one place that Vitalik + + + align:start position:0% +so that's the one place that Vitalik +Butera and who designed all of this no + + align:start position:0% +Butera and who designed all of this no + + + align:start position:0% +Butera and who designed all of this no +had to go a different way instead of + + align:start position:0% +had to go a different way instead of + + + align:start position:0% +had to go a different way instead of +transaction inputs and outputs there's + + align:start position:0% +transaction inputs and outputs there's + + + align:start position:0% +transaction inputs and outputs there's +something called state transitions + + align:start position:0% + + + + align:start position:0% + +Isabella Ledger's what are the two + + align:start position:0% +Isabella Ledger's what are the two + + + align:start position:0% +Isabella Ledger's what are the two +different types of Ledger's that we + + align:start position:0% +different types of Ledger's that we + + + align:start position:0% +different types of Ledger's that we +talked about in class two permissioned + + align:start position:0% +talked about in class two permissioned + + + align:start position:0% +talked about in class two permissioned +and public are two different types of + + align:start position:0% +and public are two different types of + + + align:start position:0% +and public are two different types of +blockchains about remind me your name + + align:start position:0% +blockchains about remind me your name + + + align:start position:0% +blockchains about remind me your name +again Stephanie so balanced ledger and + + align:start position:0% +again Stephanie so balanced ledger and + + + align:start position:0% +again Stephanie so balanced ledger and +transaction ledger you can keep a list + + align:start position:0% +transaction ledger you can keep a list + + + align:start position:0% +transaction ledger you can keep a list +of transactions and this goes back + + align:start position:0% +of transactions and this goes back + + + align:start position:0% +of transactions and this goes back +thousands of years this is not + + align:start position:0% +thousands of years this is not + + + align:start position:0% +thousands of years this is not +blockchain or you can keep balances + + align:start position:0% +blockchain or you can keep balances + + + align:start position:0% +blockchain or you can keep balances +Bitcoin is in essence a transaction + + align:start position:0% +Bitcoin is in essence a transaction + + + align:start position:0% +Bitcoin is in essence a transaction +ledger the theorem and many of the other + + align:start position:0% +ledger the theorem and many of the other + + + align:start position:0% +ledger the theorem and many of the other +smart contract platforms are balance + + align:start position:0% +smart contract platforms are balance + + + align:start position:0% +smart contract platforms are balance +Ledger's there's a lot of technological + + align:start position:0% +Ledger's there's a lot of technological + + + align:start position:0% +Ledger's there's a lot of technological +and mathematical reasons why which I'd + + align:start position:0% +and mathematical reasons why which I'd + + + align:start position:0% +and mathematical reasons why which I'd +be glad to do in office hours but + + align:start position:0% +be glad to do in office hours but + + + align:start position:0% +be glad to do in office hours but +because of that when you're moving from + + align:start position:0% +because of that when you're moving from + + + align:start position:0% +because of that when you're moving from +one set of balances like is it buh buh + + align:start position:0% +one set of balances like is it buh buh + + + align:start position:0% +one set of balances like is it buh buh +has $100 at Bank of America - buh having + + align:start position:0% +has $100 at Bank of America - buh having + + + align:start position:0% +has $100 at Bank of America - buh having +a hundred and one dollars you need to + + align:start position:0% +a hundred and one dollars you need to + + + align:start position:0% +a hundred and one dollars you need to +have a transition it's called a state + + align:start position:0% +have a transition it's called a state + + + align:start position:0% +have a transition it's called a state +transition which would mean add one + + align:start position:0% +transition which would mean add one + + + align:start position:0% +transition which would mean add one +dollar but so aetherium is an account + + align:start position:0% +dollar but so aetherium is an account + + + align:start position:0% +dollar but so aetherium is an account +based and an in fact doesn't even have + + align:start position:0% +based and an in fact doesn't even have + + + align:start position:0% +based and an in fact doesn't even have +one programming language there's six or + + align:start position:0% +one programming language there's six or + + + align:start position:0% +one programming language there's six or +seven programming languages you can + + align:start position:0% +seven programming languages you can + + + align:start position:0% +seven programming languages you can +write in for those who are so inclined + + align:start position:0% +write in for those who are so inclined + + + align:start position:0% +write in for those who are so inclined +so I'm going to go through really + + align:start position:0% +so I'm going to go through really + + + align:start position:0% +so I'm going to go through really +quickly my analysis and many other + + align:start position:0% +quickly my analysis and many other + + + align:start position:0% +quickly my analysis and many other +people's put up my sort of rendition of + + align:start position:0% +people's put up my sort of rendition of + + + align:start position:0% +people's put up my sort of rendition of +the difference between aetherium in + + align:start position:0% +the difference between aetherium in + + + align:start position:0% +the difference between aetherium in +Bitcoin + + align:start position:0% +Bitcoin + + + align:start position:0% +Bitcoin +but stop me if there's a question so the + + align:start position:0% +but stop me if there's a question so the + + + align:start position:0% +but stop me if there's a question so the +founder there's actually a founder the + + align:start position:0% +founder there's actually a founder the + + + align:start position:0% +founder there's actually a founder the +the mythology around + + align:start position:0% +the mythology around + + + align:start position:0% +the mythology around +Vitalik bhooteriya might not be as great + + align:start position:0% +Vitalik bhooteriya might not be as great + + + align:start position:0% +Vitalik bhooteriya might not be as great +as Satoshi Nakamoto but a 19 year old + + align:start position:0% +as Satoshi Nakamoto but a 19 year old + + + align:start position:0% +as Satoshi Nakamoto but a 19 year old +journalist who was writing about Bitcoin + + align:start position:0% +journalist who was writing about Bitcoin + + + align:start position:0% +journalist who was writing about Bitcoin +for was a Bitcoin magazine if I remember + + align:start position:0% +for was a Bitcoin magazine if I remember + + + align:start position:0% +for was a Bitcoin magazine if I remember +that where he was writing said we can + + align:start position:0% +that where he was writing said we can + + + align:start position:0% +that where he was writing said we can +build something on top of it using Nick + + align:start position:0% +build something on top of it using Nick + + + align:start position:0% +build something on top of it using Nick +Sabo's thoughts about smart contracts + + align:start position:0% +Sabo's thoughts about smart contracts + + + align:start position:0% +Sabo's thoughts about smart contracts +about six years after Bitcoin he made a + + align:start position:0% +about six years after Bitcoin he made a + + + align:start position:0% +about six years after Bitcoin he made a +touring complete does anyone want to + + align:start position:0% +touring complete does anyone want to + + + align:start position:0% +touring complete does anyone want to +remind the class what touring complete + + align:start position:0% +remind the class what touring complete + + + align:start position:0% +remind the class what touring complete +is did I see a hand up yes + + align:start position:0% +is did I see a hand up yes + + + align:start position:0% +is did I see a hand up yes +bold of you what's your first name again + + align:start position:0% + + + + align:start position:0% + +Alana says touring complete means you + + align:start position:0% +Alana says touring complete means you + + + align:start position:0% +Alana says touring complete means you +can write loops but what that really + + align:start position:0% +can write loops but what that really + + + align:start position:0% +can write loops but what that really +means for the the business crowd is it + + align:start position:0% +means for the the business crowd is it + + + align:start position:0% +means for the the business crowd is it +means you can write a program to do just + + align:start position:0% +means you can write a program to do just + + + align:start position:0% +means you can write a program to do just +about anything it's highly flexible + + align:start position:0% +about anything it's highly flexible + + + align:start position:0% +about anything it's highly flexible +I'm sure the technologists and here will + + align:start position:0% +I'm sure the technologists and here will + + + align:start position:0% +I'm sure the technologists and here will +say well maybe there's something you + + align:start position:0% +say well maybe there's something you + + + align:start position:0% +say well maybe there's something you +can't do with it but the the point and + + align:start position:0% +can't do with it but the the point and + + + align:start position:0% +can't do with it but the the point and +what vitalik said is we shouldn't just + + align:start position:0% +what vitalik said is we shouldn't just + + + align:start position:0% +what vitalik said is we shouldn't just +limit it to a scripting language that + + align:start position:0% +limit it to a scripting language that + + + align:start position:0% +limit it to a scripting language that +was non touring complete that can just + + align:start position:0% +was non touring complete that can just + + + align:start position:0% +was non touring complete that can just +move a little bit appear to peer value + + align:start position:0% +move a little bit appear to peer value + + + align:start position:0% +move a little bit appear to peer value +around that he wanted to do basically a + + align:start position:0% +around that he wanted to do basically a + + + align:start position:0% +around that he wanted to do basically a +peer-to-peer virtual computer that could + + align:start position:0% +peer-to-peer virtual computer that could + + + align:start position:0% +peer-to-peer virtual computer that could +move code and complete code and he in + + align:start position:0% +move code and complete code and he in + + + align:start position:0% +move code and complete code and he in +over the years it's being able to be + + align:start position:0% +over the years it's being able to be + + + align:start position:0% +over the years it's being able to be +written in a bunch of things but + + align:start position:0% +written in a bunch of things but + + + align:start position:0% +written in a bunch of things but +solidity is the main program language + + align:start position:0% +solidity is the main program language + + + align:start position:0% +solidity is the main program language +and thus its account based rather than + + align:start position:0% +and thus its account based rather than + + + align:start position:0% +and thus its account based rather than +transaction based because of the loops + + align:start position:0% +transaction based because of the loops + + + align:start position:0% +transaction based because of the loops +if you could loop and be tore and + + align:start position:0% +if you could loop and be tore and + + + align:start position:0% +if you could loop and be tore and +complete with transactions there was a + + align:start position:0% +complete with transactions there was a + + + align:start position:0% +complete with transactions there was a +vulnerability and attack vectors that he + + align:start position:0% +vulnerability and attack vectors that he + + + align:start position:0% +vulnerability and attack vectors that he +he made it account based the + + align:start position:0% +he made it account based the + + + align:start position:0% +he made it account based the +transactions are stored in merkel keys + + align:start position:0% +transactions are stored in merkel keys + + + align:start position:0% +transactions are stored in merkel keys +but guess what if you really interests + + align:start position:0% +but guess what if you really interests + + + align:start position:0% +but guess what if you really interests +and wanted to learn everything about + + align:start position:0% +and wanted to learn everything about + + + align:start position:0% +and wanted to learn everything about +aetherium there's at least four key + + align:start position:0% +aetherium there's at least four key + + + align:start position:0% +aetherium there's at least four key +Merkel trees that get summarized up into + + align:start position:0% +Merkel trees that get summarized up into + + + align:start position:0% +Merkel trees that get summarized up into +that block headers + + align:start position:0% +that block headers + + + align:start position:0% +that block headers +there's the transactions which in + + align:start position:0% +there's the transactions which in + + + align:start position:0% +there's the transactions which in +essence aren't transactions they call + + align:start position:0% +essence aren't transactions they call + + + align:start position:0% +essence aren't transactions they call +them state + + align:start position:0% +them state + + + align:start position:0% +them state +there's the state itself something + + align:start position:0% +there's the state itself something + + + align:start position:0% +there's the state itself something +called storage which is really related + + align:start position:0% +called storage which is really related + + + align:start position:0% +called storage which is really related +to each one of the individual aetherium + + align:start position:0% +to each one of the individual aetherium + + + align:start position:0% +to each one of the individual aetherium +accounts and that believe it or not + + align:start position:0% +accounts and that believe it or not + + + align:start position:0% +accounts and that believe it or not +actually receipts there's a written + + align:start position:0% +actually receipts there's a written + + + align:start position:0% +actually receipts there's a written +records of receipts from every state + + align:start position:0% +records of receipts from every state + + + align:start position:0% +records of receipts from every state +transition so there's a lot more + + align:start position:0% +transition so there's a lot more + + + align:start position:0% +transition so there's a lot more +complexity inside the etherium + + align:start position:0% +complexity inside the etherium + + + align:start position:0% +complexity inside the etherium +blockchain + + align:start position:0% +blockchain + + + align:start position:0% +blockchain +they write about fourteen seconds of + + align:start position:0% +they write about fourteen seconds of + + + align:start position:0% +they write about fourteen seconds of +block instead of ten minutes and that + + align:start position:0% +block instead of ten minutes and that + + + align:start position:0% +block instead of ten minutes and that +changes a bunch of the economics proof + + align:start position:0% +changes a bunch of the economics proof + + + align:start position:0% +changes a bunch of the economics proof +of work for some reason which others can + + align:start position:0% +of work for some reason which others can + + + align:start position:0% +of work for some reason which others can +study + + align:start position:0% +study + + + align:start position:0% +study +Vitalik decided to use a different hash + + align:start position:0% +Vitalik decided to use a different hash + + + align:start position:0% +Vitalik decided to use a different hash +function it's still based on elliptic + + align:start position:0% +function it's still based on elliptic + + + align:start position:0% +function it's still based on elliptic +curves I think but a different hash + + align:start position:0% +curves I think but a different hash + + + align:start position:0% +curves I think but a different hash +function what about the economics well + + align:start position:0% +function what about the economics well + + + align:start position:0% +function what about the economics well +it's called a third ETH it's programmed + + align:start position:0% +it's called a third ETH it's programmed + + + align:start position:0% +it's called a third ETH it's programmed +in such a way that you can't use a six + + align:start position:0% +in such a way that you can't use a six + + + align:start position:0% +in such a way that you can't use a six +purposely sort of it makes it that + + align:start position:0% +purposely sort of it makes it that + + + align:start position:0% +purposely sort of it makes it that +mining is more decentralized and you + + align:start position:0% +mining is more decentralized and you + + + align:start position:0% +mining is more decentralized and you +don't have the big factories the entire + + align:start position:0% +don't have the big factories the entire + + + align:start position:0% +don't have the big factories the entire +hash community the entire mining + + align:start position:0% +hash community the entire mining + + + align:start position:0% +hash community the entire mining +community is much smaller in fact I + + align:start position:0% +community is much smaller in fact I + + + align:start position:0% +community is much smaller in fact I +think it's about what would that be two + + align:start position:0% +think it's about what would that be two + + + align:start position:0% +think it's about what would that be two +hundred thousand times smaller there's + + align:start position:0% +hundred thousand times smaller there's + + + align:start position:0% +hundred thousand times smaller there's +two hundred and sixty tera hashes per + + align:start position:0% +two hundred and sixty tera hashes per + + + align:start position:0% +two hundred and sixty tera hashes per +second as of yesterday and the Bitcoin + + align:start position:0% +second as of yesterday and the Bitcoin + + + align:start position:0% +second as of yesterday and the Bitcoin +mining community has 54 EXA hashes that + + align:start position:0% +mining community has 54 EXA hashes that + + + align:start position:0% +mining community has 54 EXA hashes that +means lots more computers a lot more + + align:start position:0% +means lots more computers a lot more + + + align:start position:0% +means lots more computers a lot more +electricity a lot more nationally of + + align:start position:0% +electricity a lot more nationally of + + + align:start position:0% +electricity a lot more nationally of +teeth about resources Bitcoin started in + + align:start position:0% +teeth about resources Bitcoin started in + + + align:start position:0% +teeth about resources Bitcoin started in +January of 2009 and nobody owned any + + align:start position:0% +January of 2009 and nobody owned any + + + align:start position:0% +January of 2009 and nobody owned any +Bitcoin whereas aetherium started with a + + align:start position:0% +Bitcoin whereas aetherium started with a + + + align:start position:0% +Bitcoin whereas aetherium started with a +pre-sale and an IC o---- which we'll be + + align:start position:0% +pre-sale and an IC o---- which we'll be + + + align:start position:0% +pre-sale and an IC o---- which we'll be +talking about about 72 million aetherium + + align:start position:0% +talking about about 72 million aetherium + + + align:start position:0% +talking about about 72 million aetherium +the talaq wanted to raise money he was + + align:start position:0% +the talaq wanted to raise money he was + + + align:start position:0% +the talaq wanted to raise money he was +maybe 19 years old he looped in with a + + align:start position:0% +maybe 19 years old he looped in with a + + + align:start position:0% +maybe 19 years old he looped in with a +venture capitalist from Canada Joe Lubin + + align:start position:0% +venture capitalist from Canada Joe Lubin + + + align:start position:0% +venture capitalist from Canada Joe Lubin +who now runs Consensus lumen took about + + align:start position:0% +who now runs Consensus lumen took about + + + align:start position:0% +who now runs Consensus lumen took about +10% or nine and a half percent of the + + align:start position:0% +10% or nine and a half percent of the + + + align:start position:0% +10% or nine and a half percent of the +offering they put nine half percent in a + + align:start position:0% +offering they put nine half percent in a + + + align:start position:0% +offering they put nine half percent in a +foundation called the etherium + + align:start position:0% +foundation called the etherium + + + align:start position:0% +foundation called the etherium +foundation and the other 80% was sold to + + align:start position:0% +foundation and the other 80% was sold to + + + align:start position:0% +foundation and the other 80% was sold to +the public for 18 million dollars + + align:start position:0% + + + + align:start position:0% + +we'll talk later in the semester as to + + align:start position:0% +we'll talk later in the semester as to + + + align:start position:0% +we'll talk later in the semester as to +whether that was really a securities + + align:start position:0% +whether that was really a securities + + + align:start position:0% +whether that was really a securities +offering I publicly said I think so but + + align:start position:0% +offering I publicly said I think so but + + + align:start position:0% +offering I publicly said I think so but +that was in 2014 and in 2018 and the + + align:start position:0% +that was in 2014 and in 2018 and the + + + align:start position:0% +that was in 2014 and in 2018 and the +Securities and Exchange Commission has + + align:start position:0% +Securities and Exchange Commission has + + + align:start position:0% +Securities and Exchange Commission has +said regardless of what it might have + + align:start position:0% +said regardless of what it might have + + + align:start position:0% +said regardless of what it might have +been in 14 it's now sufficiently + + align:start position:0% +been in 14 it's now sufficiently + + + align:start position:0% +been in 14 it's now sufficiently +decentralized that we'll consider it not + + align:start position:0% +decentralized that we'll consider it not + + + align:start position:0% +decentralized that we'll consider it not +as security but in essence they raised + + align:start position:0% +as security but in essence they raised + + + align:start position:0% +as security but in essence they raised +18 million dollars and were off to the + + align:start position:0% +18 million dollars and were off to the + + + align:start position:0% +18 million dollars and were off to the +races + + align:start position:0% +races + + + align:start position:0% +races +oh and the 10% that Joe Lubin capped if + + align:start position:0% +oh and the 10% that Joe Lubin capped if + + + align:start position:0% +oh and the 10% that Joe Lubin capped if +he still owned it would be worth about + + align:start position:0% +he still owned it would be worth about + + + align:start position:0% +he still owned it would be worth about +two billion dollars now but he probably + + align:start position:0% +two billion dollars now but he probably + + + align:start position:0% +two billion dollars now but he probably +sold some of it along the way there + + align:start position:0% +sold some of it along the way there + + + align:start position:0% +sold some of it along the way there +block rewards the monetary policy in + + align:start position:0% +block rewards the monetary policy in + + + align:start position:0% +block rewards the monetary policy in +aetherium if you remember it splits + + align:start position:0% +aetherium if you remember it splits + + + align:start position:0% +aetherium if you remember it splits +every four years you know that there's a + + align:start position:0% +every four years you know that there's a + + + align:start position:0% +every four years you know that there's a +block reward splits + + align:start position:0% +block reward splits + + + align:start position:0% +block reward splits +etherium was set up that was five if the + + align:start position:0% +etherium was set up that was five if the + + + align:start position:0% +etherium was set up that was five if the +ether per block and then a year ago they + + align:start position:0% +ether per block and then a year ago they + + + align:start position:0% +ether per block and then a year ago they +just announced they were gonna change + + align:start position:0% +just announced they were gonna change + + + align:start position:0% +just announced they were gonna change +the software to three ether per block + + align:start position:0% +the software to three ether per block + + + align:start position:0% +the software to three ether per block +and a month ago they announced they're + + align:start position:0% +and a month ago they announced they're + + + align:start position:0% +and a month ago they announced they're +gonna change it to two ether per block + + align:start position:0% +gonna change it to two ether per block + + + align:start position:0% +gonna change it to two ether per block +so the monetary policy of Bitcoin is + + align:start position:0% +so the monetary policy of Bitcoin is + + + align:start position:0% +so the monetary policy of Bitcoin is +said to be immutable and fixed forever + + align:start position:0% +said to be immutable and fixed forever + + + align:start position:0% +said to be immutable and fixed forever +but I would say that because he theorem + + align:start position:0% +but I would say that because he theorem + + + align:start position:0% +but I would say that because he theorem +supposedly was fixed and now twice + + align:start position:0% +supposedly was fixed and now twice + + + align:start position:0% +supposedly was fixed and now twice +they've changed the monetary policy + + align:start position:0% +they've changed the monetary policy + + + align:start position:0% +they've changed the monetary policy +there is a form that if all the miners + + align:start position:0% +there is a form that if all the miners + + + align:start position:0% +there is a form that if all the miners +and all the computer nodes decide they + + align:start position:0% +and all the computer nodes decide they + + + align:start position:0% +and all the computer nodes decide they +can change the monetary policy and if + + align:start position:0% +can change the monetary policy and if + + + align:start position:0% +can change the monetary policy and if +the etherium is shown that I think + + align:start position:0% +the etherium is shown that I think + + + align:start position:0% +the etherium is shown that I think +aetherium was a bit more centralized and + + align:start position:0% +aetherium was a bit more centralized and + + + align:start position:0% +aetherium was a bit more centralized and +has more leadership because Vitalik + + align:start position:0% +has more leadership because Vitalik + + + align:start position:0% +has more leadership because Vitalik +bhooteriya is an actual human who's + + align:start position:0% +bhooteriya is an actual human who's + + + align:start position:0% +bhooteriya is an actual human who's +willing to disclose who he is and he + + align:start position:0% +willing to disclose who he is and he + + + align:start position:0% +willing to disclose who he is and he +still has the sort of founder following + + align:start position:0% +still has the sort of founder following + + + align:start position:0% +still has the sort of founder following +and Satoshi Nakamoto went he ghosted all + + align:start position:0% +and Satoshi Nakamoto went he ghosted all + + + align:start position:0% +and Satoshi Nakamoto went he ghosted all +of us in a sense and so thus it's it's + + align:start position:0% +of us in a sense and so thus it's it's + + + align:start position:0% +of us in a sense and so thus it's it's +in some ways socially just more set + + align:start position:0% +in some ways socially just more set + + + align:start position:0% +in some ways socially just more set +decentralized and then fees are + + align:start position:0% +decentralized and then fees are + + + align:start position:0% +decentralized and then fees are +voluntary in Bitcoin they're a necessary + + align:start position:0% +voluntary in Bitcoin they're a necessary + + + align:start position:0% +voluntary in Bitcoin they're a necessary +part to channel everything Emily policy + + align:start position:0% +part to channel everything Emily policy + + + align:start position:0% +part to channel everything Emily policy +in practice what does it actually mean + + align:start position:0% +in practice what does it actually mean + + + align:start position:0% +in practice what does it actually mean +for like a difference between Bitcoin + + align:start position:0% +for like a difference between Bitcoin + + + align:start position:0% +for like a difference between Bitcoin +and a cerium that it's fixed for + + align:start position:0% +and a cerium that it's fixed for + + + align:start position:0% +and a cerium that it's fixed for +changing + + align:start position:0% +changing + + + align:start position:0% +changing +staying at that tape so Emily asked what + + align:start position:0% +staying at that tape so Emily asked what + + + align:start position:0% +staying at that tape so Emily asked what +does it mean in practice in practice + + align:start position:0% +does it mean in practice in practice + + + align:start position:0% +does it mean in practice in practice +Bitcoin has a much slower growth rate or + + align:start position:0% +Bitcoin has a much slower growth rate or + + + align:start position:0% +Bitcoin has a much slower growth rate or +inflation rate which is currently if I'm + + align:start position:0% +inflation rate which is currently if I'm + + + align:start position:0% +inflation rate which is currently if I'm +not mistaken about half what's that for + + align:start position:0% +not mistaken about half what's that for + + + align:start position:0% +not mistaken about half what's that for +about 4% but it's about half of the + + align:start position:0% +about 4% but it's about half of the + + + align:start position:0% +about 4% but it's about half of the +inflation rate at a theorem which is + + align:start position:0% +inflation rate at a theorem which is + + + align:start position:0% +inflation rate at a theorem which is +running in the 7% range every one of the + + align:start position:0% +running in the 7% range every one of the + + + align:start position:0% +running in the 7% range every one of the +1600 live tokens that are right now all + + align:start position:0% +1600 live tokens that are right now all + + + align:start position:0% +1600 live tokens that are right now all +coins have separate monetary policies + + align:start position:0% +coins have separate monetary policies + + + align:start position:0% +coins have separate monetary policies +and one could do a complete economic + + align:start position:0% +and one could do a complete economic + + + align:start position:0% +and one could do a complete economic +study about what it means but in terms + + align:start position:0% +study about what it means but in terms + + + align:start position:0% +study about what it means but in terms +of aetherium versus Bitcoin aetherium + + align:start position:0% +of aetherium versus Bitcoin aetherium + + + align:start position:0% +of aetherium versus Bitcoin aetherium +has a higher inflation rate and secondly + + align:start position:0% +has a higher inflation rate and secondly + + + align:start position:0% +has a higher inflation rate and secondly +because they've shown that they can form + + align:start position:0% +because they've shown that they can form + + + align:start position:0% +because they've shown that they can form +some consensus and change it I think it + + align:start position:0% +some consensus and change it I think it + + + align:start position:0% +some consensus and change it I think it +sends an interesting question into that + + align:start position:0% +sends an interesting question into that + + + align:start position:0% +sends an interesting question into that +that ecosystem as to how hard a monetary + + align:start position:0% +that ecosystem as to how hard a monetary + + + align:start position:0% +that ecosystem as to how hard a monetary +policy versus more human based flexible + + align:start position:0% +policy versus more human based flexible + + + align:start position:0% +policy versus more human based flexible +monetary policy Hugo the ethereum + + align:start position:0% +monetary policy Hugo the ethereum + + + align:start position:0% +monetary policy Hugo the ethereum +blockchain decide or so the core + + align:start position:0% +blockchain decide or so the core + + + align:start position:0% +blockchain decide or so the core +developers of any coin can propose to + + align:start position:0% +developers of any coin can propose to + + + align:start position:0% +developers of any coin can propose to +the various mining and nodes to make a + + align:start position:0% +the various mining and nodes to make a + + + align:start position:0% +the various mining and nodes to make a +change including the monetary policy + + align:start position:0% +change including the monetary policy + + + align:start position:0% +change including the monetary policy +even in Bitcoin the monetary policy + + align:start position:0% +even in Bitcoin the monetary policy + + + align:start position:0% +even in Bitcoin the monetary policy +could change if there was a proposal + + align:start position:0% +could change if there was a proposal + + + align:start position:0% +could change if there was a proposal +from the core developers in the theory + + align:start position:0% +from the core developers in the theory + + + align:start position:0% +from the core developers in the theory +of case they have done that twice the + + align:start position:0% +of case they have done that twice the + + + align:start position:0% +of case they have done that twice the +core development of aetherium is highly + + align:start position:0% +core development of aetherium is highly + + + align:start position:0% +core development of aetherium is highly +concentrated around the etherium + + align:start position:0% +concentrated around the etherium + + + align:start position:0% +concentrated around the etherium +foundation consensus the company that + + align:start position:0% +foundation consensus the company that + + + align:start position:0% +foundation consensus the company that +joe Lubin ron's has some normative + + align:start position:0% +joe Lubin ron's has some normative + + + align:start position:0% +joe Lubin ron's has some normative +social standing in the community as well + + align:start position:0% +social standing in the community as well + + + align:start position:0% +social standing in the community as well +but it's been it's been part of + + align:start position:0% +but it's been it's been part of + + + align:start position:0% +but it's been it's been part of +proposals and in reading the proposals + + align:start position:0% +proposals and in reading the proposals + + + align:start position:0% +proposals and in reading the proposals +that goes back to Emily's question the + + align:start position:0% +that goes back to Emily's question the + + + align:start position:0% +that goes back to Emily's question the +court of ella pers have said we should + + align:start position:0% +court of ella pers have said we should + + + align:start position:0% +court of ella pers have said we should +bring down the inflation rate like + + align:start position:0% +bring down the inflation rate like + + + align:start position:0% +bring down the inflation rate like +there's an active advocacy to bring down + + align:start position:0% +there's an active advocacy to bring down + + + align:start position:0% +there's an active advocacy to bring down +no and software or yes in essence buy + + align:start position:0% +no and software or yes in essence buy + + + align:start position:0% +no and software or yes in essence buy +and it could lead to a hard fork + + align:start position:0% +and it could lead to a hard fork + + + align:start position:0% +and it could lead to a hard fork +I believe so that's the background let + + align:start position:0% +I believe so that's the background let + + + align:start position:0% +I believe so that's the background let +me just talk about the platforms we know + + align:start position:0% +me just talk about the platforms we know + + + align:start position:0% +me just talk about the platforms we know +about aetherium we've just chatted about + + align:start position:0% +about aetherium we've just chatted about + + + align:start position:0% +about aetherium we've just chatted about +it it's actual current market value was + + align:start position:0% +it it's actual current market value was + + + align:start position:0% +it it's actual current market value was +22 billion well we're not going to spend + + align:start position:0% +22 billion well we're not going to spend + + + align:start position:0% +22 billion well we're not going to spend +a lot of time in this this class this + + align:start position:0% +a lot of time in this this class this + + + align:start position:0% +a lot of time in this this class this +semester about market values I thought + + align:start position:0% +semester about market values I thought + + + align:start position:0% +semester about market values I thought +it would give you a sense of how people + + align:start position:0% +it would give you a sense of how people + + + align:start position:0% +it would give you a sense of how people +think about it the other five that you + + align:start position:0% +think about it the other five that you + + + align:start position:0% +think about it the other five that you +did some reading about EEO smark values + + align:start position:0% +did some reading about EEO smark values + + + align:start position:0% +did some reading about EEO smark values +about five billion is so new because + + align:start position:0% +about five billion is so new because + + + align:start position:0% +about five billion is so new because +they just finished a initial coin + + align:start position:0% +they just finished a initial coin + + + align:start position:0% +they just finished a initial coin +offering in july and they just went live + + align:start position:0% +offering in july and they just went live + + + align:start position:0% +offering in july and they just went live +in july but they raised 4.2 billion + + align:start position:0% +in july but they raised 4.2 billion + + + align:start position:0% +in july but they raised 4.2 billion +dollars so my my estimate my prediction + + align:start position:0% +dollars so my my estimate my prediction + + + align:start position:0% +dollars so my my estimate my prediction +is EOS is going to be real and going to + + align:start position:0% +is EOS is going to be real and going to + + + align:start position:0% +is EOS is going to be real and going to +be around + + align:start position:0% +be around + + + align:start position:0% +be around +they've taken 1 billion of that 4.2 + + align:start position:0% +they've taken 1 billion of that 4.2 + + + align:start position:0% +they've taken 1 billion of that 4.2 +billion and set up a Kickstarter sort of + + align:start position:0% +billion and set up a Kickstarter sort of + + + align:start position:0% +billion and set up a Kickstarter sort of +venture firm literally so that they + + align:start position:0% +venture firm literally so that they + + + align:start position:0% +venture firm literally so that they +could maybe support some of you you + + align:start position:0% +could maybe support some of you you + + + align:start position:0% +could maybe support some of you you +could be knocking on the eos venture + + align:start position:0% +could be knocking on the eos venture + + + align:start position:0% +could be knocking on the eos venture +firms door and saying fund me I've got a + + align:start position:0% +firms door and saying fund me I've got a + + + align:start position:0% +firms door and saying fund me I've got a +great idea and they'd have one condition + + align:start position:0% +great idea and they'd have one condition + + + align:start position:0% +great idea and they'd have one condition +amongst others you'd have to use Geo's + + align:start position:0% +amongst others you'd have to use Geo's + + + align:start position:0% +amongst others you'd have to use Geo's +as the platform so you know it's it's a + + align:start position:0% +as the platform so you know it's it's a + + + align:start position:0% +as the platform so you know it's it's a +self-reinforcing business model neo is + + align:start position:0% +self-reinforcing business model neo is + + + align:start position:0% +self-reinforcing business model neo is +the other big one that I'd mentioned + + align:start position:0% +the other big one that I'd mentioned + + + align:start position:0% +the other big one that I'd mentioned +which was started two years ago out of + + align:start position:0% +which was started two years ago out of + + + align:start position:0% +which was started two years ago out of +China a lot of people think with the + + align:start position:0% +China a lot of people think with the + + + align:start position:0% +China a lot of people think with the +backing of the Chinese government even + + align:start position:0% +backing of the Chinese government even + + + align:start position:0% +backing of the Chinese government even +not officially certainly with the the + + align:start position:0% +not officially certainly with the the + + + align:start position:0% +not officially certainly with the the +verbal and help of their some people + + align:start position:0% +verbal and help of their some people + + + align:start position:0% +verbal and help of their some people +think of it as the etherium of China but + + align:start position:0% +think of it as the etherium of China but + + + align:start position:0% +think of it as the etherium of China but +it does use a different proof of work + + align:start position:0% +it does use a different proof of work + + + align:start position:0% +it does use a different proof of work +and those are the main ones aetherium + + align:start position:0% +and those are the main ones aetherium + + + align:start position:0% +and those are the main ones aetherium +classic is there because there was a + + align:start position:0% +classic is there because there was a + + + align:start position:0% +classic is there because there was a +hard fork off of aetherium after the Dow + + align:start position:0% +hard fork off of aetherium after the Dow + + + align:start position:0% +hard fork off of aetherium after the Dow +Dow + + align:start position:0% +Dow + + + align:start position:0% +Dow +circumstance any quick questions about + + align:start position:0% +circumstance any quick questions about + + + align:start position:0% +circumstance any quick questions about +the platforms and nee and neo and EEO + + align:start position:0% +the platforms and nee and neo and EEO + + + align:start position:0% +the platforms and nee and neo and EEO +Tsar thought to be a little bit higher + + align:start position:0% +Tsar thought to be a little bit higher + + + align:start position:0% +Tsar thought to be a little bit higher +throughput and faster because of the + + align:start position:0% +throughput and faster because of the + + + align:start position:0% +throughput and faster because of the +different proof of work that each of + + align:start position:0% +different proof of work that each of + + + align:start position:0% +different proof of work that each of +them have so maybe they're more scalable + + align:start position:0% +them have so maybe they're more scalable + + + align:start position:0% +them have so maybe they're more scalable +than aetherium long term + + align:start position:0% +than aetherium long term + + + align:start position:0% +than aetherium long term +what's that so Hugo is pointing out that + + align:start position:0% +what's that so Hugo is pointing out that + + + align:start position:0% +what's that so Hugo is pointing out that +neither one truly used neo and ia's and + + align:start position:0% +neither one truly used neo and ia's and + + + align:start position:0% +neither one truly used neo and ia's and +truly use decentralized proof-of-work + + align:start position:0% +truly use decentralized proof-of-work + + + align:start position:0% +truly use decentralized proof-of-work +they use a delegated Byzantine fault + + align:start position:0% +they use a delegated Byzantine fault + + + align:start position:0% +they use a delegated Byzantine fault +tolerance this was from the reading + + align:start position:0% +tolerance this was from the reading + + + align:start position:0% +tolerance this was from the reading +we're not going to spend time on it but + + align:start position:0% +we're not going to spend time on it but + + + align:start position:0% +we're not going to spend time on it but +there was there was 12 use cases that + + align:start position:0% +there was there was 12 use cases that + + + align:start position:0% +there was there was 12 use cases that +the digital Chamber of Commerce came up + + align:start position:0% +the digital Chamber of Commerce came up + + + align:start position:0% +the digital Chamber of Commerce came up +with and we're gonna study most of these + + align:start position:0% +with and we're gonna study most of these + + + align:start position:0% +with and we're gonna study most of these +not all of these later in the semester + + align:start position:0% +not all of these later in the semester + + + align:start position:0% +not all of these later in the semester +I'm please tell me the question is is + + align:start position:0% +I'm please tell me the question is is + + + align:start position:0% +I'm please tell me the question is is +two multi-language platforms have more + + align:start position:0% +two multi-language platforms have more + + + align:start position:0% +two multi-language platforms have more +potential or less than single language + + align:start position:0% +potential or less than single language + + + align:start position:0% +potential or less than single language +platforms I haven't done a real study + + align:start position:0% +platforms I haven't done a real study + + + align:start position:0% +platforms I haven't done a real study +Mike my gut tells me that there's some + + align:start position:0% +Mike my gut tells me that there's some + + + align:start position:0% +Mike my gut tells me that there's some +trade-offs a multi-language platform + + align:start position:0% +trade-offs a multi-language platform + + + align:start position:0% +trade-offs a multi-language platform +probably allows for more development of + + align:start position:0% +probably allows for more development of + + + align:start position:0% +probably allows for more development of +apps just like on the internet you know + + align:start position:0% +apps just like on the internet you know + + + align:start position:0% +apps just like on the internet you know +if you can have more app development + + align:start position:0% +if you can have more app development + + + align:start position:0% +if you can have more app development +though if you have only one single + + align:start position:0% +though if you have only one single + + + align:start position:0% +though if you have only one single +language you might have fewer + + align:start position:0% +language you might have fewer + + + align:start position:0% +language you might have fewer +vulnerabilities vulnerabilities either + + align:start position:0% +vulnerabilities vulnerabilities either + + + align:start position:0% +vulnerabilities vulnerabilities either +to attack or coming down so there's + + align:start position:0% +to attack or coming down so there's + + + align:start position:0% +to attack or coming down so there's +probably some trade-offs and I'm more + + align:start position:0% +probably some trade-offs and I'm more + + + align:start position:0% +probably some trade-offs and I'm more +into democratizing capital markets so I + + align:start position:0% +into democratizing capital markets so I + + + align:start position:0% +into democratizing capital markets so I +probably my biases would be to the ones + + align:start position:0% +probably my biases would be to the ones + + + align:start position:0% +probably my biases would be to the ones +that have multi-language potential but I + + align:start position:0% +that have multi-language potential but I + + + align:start position:0% +that have multi-language potential but I +can't say for sure whether that little + + align:start position:0% +can't say for sure whether that little + + + align:start position:0% +can't say for sure whether that little +necessarily win because there are some + + align:start position:0% +necessarily win because there are some + + + align:start position:0% +necessarily win because there are some +trade-offs if that helps + + align:start position:0% +trade-offs if that helps + + + align:start position:0% +trade-offs if that helps +so we'll take a view of all of these + + align:start position:0% +so we'll take a view of all of these + + + align:start position:0% +so we'll take a view of all of these +later in the semester but what's + + align:start position:0% +later in the semester but what's + + + align:start position:0% +later in the semester but what's +interesting is none of them have yet + + align:start position:0% +interesting is none of them have yet + + + align:start position:0% +interesting is none of them have yet +taken off and in fact if you look at the + + align:start position:0% +taken off and in fact if you look at the + + + align:start position:0% +taken off and in fact if you look at the +DAPs today the decentralized + + align:start position:0% +DAPs today the decentralized + + + align:start position:0% +DAPs today the decentralized +applications which run on a + + align:start position:0% +applications which run on a + + + align:start position:0% +applications which run on a +decentralized blockchain they generally + + align:start position:0% +decentralized blockchain they generally + + + align:start position:0% +decentralized blockchain they generally +have native tokens they don't have to + + align:start position:0% +have native tokens they don't have to + + + align:start position:0% +have native tokens they don't have to +have a native token by the way you could + + align:start position:0% +have a native token by the way you could + + + align:start position:0% +have a native token by the way you could +run a + + align:start position:0% +run a + + + align:start position:0% +run a +based on ether you could run a DAP on + + align:start position:0% +based on ether you could run a DAP on + + + align:start position:0% +based on ether you could run a DAP on +the underlying token but they all almost + + align:start position:0% +the underlying token but they all almost + + + align:start position:0% +the underlying token but they all almost +always have their own native token this + + align:start position:0% +always have their own native token this + + + align:start position:0% +always have their own native token this +is a list that I pulled off the internet + + align:start position:0% +is a list that I pulled off the internet + + + align:start position:0% +is a list that I pulled off the internet +yesterday similar to your reading these + + align:start position:0% +yesterday similar to your reading these + + + align:start position:0% +yesterday similar to your reading these +are the actual DAPs that are working the + + align:start position:0% +are the actual DAPs that are working the + + + align:start position:0% +are the actual DAPs that are working the +highest gaming gambling exchanges in + + align:start position:0% +highest gaming gambling exchanges in + + + align:start position:0% +highest gaming gambling exchanges in +finance the the most active gap is a + + align:start position:0% +finance the the most active gap is a + + + align:start position:0% +finance the the most active gap is a +adapt is a gambling site that only has + + align:start position:0% +adapt is a gambling site that only has + + + align:start position:0% +adapt is a gambling site that only has +1,500 users a day in the last 24 hours I + + align:start position:0% +1,500 users a day in the last 24 hours I + + + align:start position:0% +1,500 users a day in the last 24 hours I +pulled this down yesterday so that was a + + align:start position:0% +pulled this down yesterday so that was a + + + align:start position:0% +pulled this down yesterday so that was a +Monday so this would have been Sunday + + align:start position:0% +Monday so this would have been Sunday + + + align:start position:0% +Monday so this would have been Sunday +night to Monday night there was only + + align:start position:0% +night to Monday night there was only + + + align:start position:0% +night to Monday night there was only +1,500 users to the most active gambling + + align:start position:0% +1,500 users to the most active gambling + + + align:start position:0% +1,500 users to the most active gambling +site crypto kitties that some of you + + align:start position:0% +site crypto kitties that some of you + + + align:start position:0% +site crypto kitties that some of you +might know had 418 users in those 24 + + align:start position:0% +might know had 418 users in those 24 + + + align:start position:0% +might know had 418 users in those 24 +hours these are not you know economy + + align:start position:0% +hours these are not you know economy + + + align:start position:0% +hours these are not you know economy +wise use case you know the these you + + align:start position:0% +wise use case you know the these you + + + align:start position:0% +wise use case you know the these you +would see numbers that were hundreds of + + align:start position:0% +would see numbers that were hundreds of + + + align:start position:0% +would see numbers that were hundreds of +thousands or if it's like Facebook + + align:start position:0% +thousands or if it's like Facebook + + + align:start position:0% +thousands or if it's like Facebook +there's two billion members and probably + + align:start position:0% +there's two billion members and probably + + + align:start position:0% +there's two billion members and probably +in any 24 hours there's a half a billion + + align:start position:0% +in any 24 hours there's a half a billion + + + align:start position:0% +in any 24 hours there's a half a billion +to a billion people that check in on + + align:start position:0% +to a billion people that check in on + + + align:start position:0% +to a billion people that check in on +Facebook so these are pretty limited at + + align:start position:0% +Facebook so these are pretty limited at + + + align:start position:0% +Facebook so these are pretty limited at +this stage but it has led to something + + align:start position:0% +this stage but it has led to something + + + align:start position:0% +this stage but it has led to something +called initial coin offerings which + + align:start position:0% +called initial coin offerings which + + + align:start position:0% +called initial coin offerings which +we're going to study a bunch later in + + align:start position:0% +we're going to study a bunch later in + + + align:start position:0% +we're going to study a bunch later in +the semester initial coin offerings + + align:start position:0% +the semester initial coin offerings + + + align:start position:0% +the semester initial coin offerings +raise money to build a network but the + + align:start position:0% +raise money to build a network but the + + + align:start position:0% +raise money to build a network but the +tokens are usually issued before they're + + align:start position:0% +tokens are usually issued before they're + + + align:start position:0% +tokens are usually issued before they're +usable and a token is some native + + align:start position:0% +usable and a token is some native + + + align:start position:0% +usable and a token is some native +currency to be used on a on a network + + align:start position:0% +currency to be used on a on a network + + + align:start position:0% +currency to be used on a on a network +the development is open but highly + + align:start position:0% +the development is open but highly + + + align:start position:0% +the development is open but highly +centralized the promoters usually give + + align:start position:0% +centralized the promoters usually give + + + align:start position:0% +centralized the promoters usually give +themselves some skin in the game or some + + align:start position:0% +themselves some skin in the game or some + + + align:start position:0% +themselves some skin in the game or some +Vig in in the theory of initial coin + + align:start position:0% +Vig in in the theory of initial coin + + + align:start position:0% +Vig in in the theory of initial coin +offering the foundation kept 10% Joe + + align:start position:0% +offering the foundation kept 10% Joe + + + align:start position:0% +offering the foundation kept 10% Joe +lube and kept 10% and the other 80% was + + align:start position:0% +lube and kept 10% and the other 80% was + + + align:start position:0% +lube and kept 10% and the other 80% was +sold to the public but some keeps sixty + + align:start position:0% +sold to the public but some keeps sixty + + + align:start position:0% +sold to the public but some keeps sixty +or eighty percent for themselves I mean + + align:start position:0% +or eighty percent for themselves I mean + + + align:start position:0% +or eighty percent for themselves I mean +it's a whole wide range of economic + + align:start position:0% +it's a whole wide range of economic + + + align:start position:0% +it's a whole wide range of economic +incentives and models and the tokens are + + align:start position:0% +incentives and models and the tokens are + + + align:start position:0% +incentives and models and the tokens are +usually fungible and transferable and + + align:start position:0% +usually fungible and transferable and + + + align:start position:0% +usually fungible and transferable and +thus you can sort of put them on an + + align:start position:0% +thus you can sort of put them on an + + + align:start position:0% +thus you can sort of put them on an +exchange and try to sell them and + + align:start position:0% +exchange and try to sell them and + + + align:start position:0% +exchange and try to sell them and +promote them and again we're going to + + align:start position:0% +promote them and again we're going to + + + align:start position:0% +promote them and again we're going to +come back but I thought if we're talking + + align:start position:0% +come back but I thought if we're talking + + + align:start position:0% +come back but I thought if we're talking +about smart contracts they + + align:start position:0% +about smart contracts they + + + align:start position:0% +about smart contracts they +I into initial coin offerings Daniel is + + align:start position:0% +I into initial coin offerings Daniel is + + + align:start position:0% +I into initial coin offerings Daniel is +an excellent question Daniel says what + + align:start position:0% +an excellent question Daniel says what + + + align:start position:0% +an excellent question Daniel says what +goes into the valuation of something + + align:start position:0% +goes into the valuation of something + + + align:start position:0% +goes into the valuation of something +that is not functional and there there + + align:start position:0% +that is not functional and there there + + + align:start position:0% +that is not functional and there there +are many things that go up and + + align:start position:0% +are many things that go up and + + + align:start position:0% +are many things that go up and +ultimately it's in the anticipation of + + align:start position:0% +ultimately it's in the anticipation of + + + align:start position:0% +ultimately it's in the anticipation of +the potential profit and appreciation in + + align:start position:0% +the potential profit and appreciation in + + + align:start position:0% +the potential profit and appreciation in +the future so if you were just to have a + + align:start position:0% +the future so if you were just to have a + + + align:start position:0% +the future so if you were just to have a +laundromat a corner laundromat here in + + align:start position:0% +laundromat a corner laundromat here in + + + align:start position:0% +laundromat a corner laundromat here in +Cambridge you probably would only pay + + align:start position:0% +Cambridge you probably would only pay + + + align:start position:0% +Cambridge you probably would only pay +for the laundromat token what you + + align:start position:0% +for the laundromat token what you + + + align:start position:0% +for the laundromat token what you +thought the value was to do your laundry + + align:start position:0% +thought the value was to do your laundry + + + align:start position:0% +thought the value was to do your laundry +whatever there's 75 cents or whatever + + align:start position:0% +whatever there's 75 cents or whatever + + + align:start position:0% +whatever there's 75 cents or whatever +that frankly I don't know what the + + align:start position:0% +that frankly I don't know what the + + + align:start position:0% +that frankly I don't know what the +tokens go for and Cameron is anyway + + align:start position:0% +tokens go for and Cameron is anyway + + + align:start position:0% +tokens go for and Cameron is anyway +you're gonna tell me what a laundromat + + align:start position:0% +you're gonna tell me what a laundromat + + + align:start position:0% +you're gonna tell me what a laundromat +token goes for but if it's pre-function + + align:start position:0% +token goes for but if it's pre-function + + + align:start position:0% +token goes for but if it's pre-function +on the laundromat has not been built yet + + align:start position:0% +on the laundromat has not been built yet + + + align:start position:0% +on the laundromat has not been built yet +you and you have confidence it will be + + align:start position:0% +you and you have confidence it will be + + + align:start position:0% +you and you have confidence it will be +built you'll probably discount back you + + align:start position:0% +built you'll probably discount back you + + + align:start position:0% +built you'll probably discount back you +might pay 50 cents instead of 75 cents + + align:start position:0% +might pay 50 cents instead of 75 cents + + + align:start position:0% +might pay 50 cents instead of 75 cents +ultimately if you think it's going to be + + align:start position:0% +ultimately if you think it's going to be + + + align:start position:0% +ultimately if you think it's going to be +a really popular laundromat and it's + + align:start position:0% +a really popular laundromat and it's + + + align:start position:0% +a really popular laundromat and it's +gonna be the place to be seen by all MIT + + align:start position:0% +gonna be the place to be seen by all MIT + + + align:start position:0% +gonna be the place to be seen by all MIT +students and you think that token might + + align:start position:0% +students and you think that token might + + + align:start position:0% +students and you think that token might +one day be worth five dollars then + + align:start position:0% +one day be worth five dollars then + + + align:start position:0% +one day be worth five dollars then +you're starting to speculate on on the + + align:start position:0% +you're starting to speculate on on the + + + align:start position:0% +you're starting to speculate on on the +Community Interest so these tokens if + + align:start position:0% +Community Interest so these tokens if + + + align:start position:0% +Community Interest so these tokens if +you really believe in them you're trying + + align:start position:0% +you really believe in them you're trying + + + align:start position:0% +you really believe in them you're trying +to pay for what others will pay for them + + align:start position:0% +to pay for what others will pay for them + + + align:start position:0% +to pay for what others will pay for them +in the future and the economic + + align:start position:0% +in the future and the economic + + + align:start position:0% +in the future and the economic +equilibrium would be discounted so thus + + align:start position:0% +equilibrium would be discounted so thus + + + align:start position:0% +equilibrium would be discounted so thus +you're buying it because you think + + align:start position:0% +you're buying it because you think + + + align:start position:0% +you're buying it because you think +they'll appreciate in value so - Isaac + + align:start position:0% +they'll appreciate in value so - Isaac + + + align:start position:0% +they'll appreciate in value so - Isaac +says but maybe there could be a news Miz + + align:start position:0% +says but maybe there could be a news Miz + + + align:start position:0% +says but maybe there could be a news Miz +Matic or or other value to it it's + + align:start position:0% +Matic or or other value to it it's + + + align:start position:0% +Matic or or other value to it it's +possible I mean certainly crypto Kitty's + + align:start position:0% +possible I mean certainly crypto Kitty's + + + align:start position:0% +possible I mean certainly crypto Kitty's +caught into the whole collectibles wave + + align:start position:0% +caught into the whole collectibles wave + + + align:start position:0% +caught into the whole collectibles wave +let me try to wrap up so that I can hand + + align:start position:0% +let me try to wrap up so that I can hand + + + align:start position:0% +let me try to wrap up so that I can hand +it off to to Larry so there's been + + align:start position:0% +it off to to Larry so there's been + + + align:start position:0% +it off to to Larry so there's been +twenty eight billion dollars raised per + + align:start position:0% +twenty eight billion dollars raised per + + + align:start position:0% +twenty eight billion dollars raised per +one website + + align:start position:0% +one website + + + align:start position:0% +one website +elementa see others the track it think + + align:start position:0% +elementa see others the track it think + + + align:start position:0% +elementa see others the track it think +it's only between 20 and 25 billion + + align:start position:0% +it's only between 20 and 25 billion + + + align:start position:0% +it's only between 20 and 25 billion +there are no official arithmetic and no + + align:start position:0% +there are no official arithmetic and no + + + align:start position:0% +there are no official arithmetic and no +official records but the twenty eight + + align:start position:0% +official records but the twenty eight + + + align:start position:0% +official records but the twenty eight +billion dollars raised in initial coin + + align:start position:0% +billion dollars raised in initial coin + + + align:start position:0% +billion dollars raised in initial coin +offerings this is a cut of a neat video + + align:start position:0% +offerings this is a cut of a neat video + + + align:start position:0% +offerings this is a cut of a neat video +that I just took the last slide of from + + align:start position:0% +that I just took the last slide of from + + + align:start position:0% +that I just took the last slide of from +elementa so you can watch it in a minute + + align:start position:0% +elementa so you can watch it in a minute + + + align:start position:0% +elementa so you can watch it in a minute +and a half and over the years it's + + align:start position:0% +and a half and over the years it's + + + align:start position:0% +and a half and over the years it's +geographically dispersed with blue being + + align:start position:0% +geographically dispersed with blue being + + + align:start position:0% +geographically dispersed with blue being +Oceania Australia and and so forth + + align:start position:0% +Oceania Australia and and so forth + + + align:start position:0% +Oceania Australia and and so forth +Green being Asia North America being + + align:start position:0% +Green being Asia North America being + + + align:start position:0% +Green being Asia North America being +orange but the biggest ones is race 4.2 + + align:start position:0% +orange but the biggest ones is race 4.2 + + + align:start position:0% +orange but the biggest ones is race 4.2 +billion telegram 1.7 billion and the + + align:start position:0% +billion telegram 1.7 billion and the + + + align:start position:0% +billion telegram 1.7 billion and the +like these are not small figures there's + + align:start position:0% +like these are not small figures there's + + + align:start position:0% +like these are not small figures there's +been forty five hundred at least forty + + align:start position:0% +been forty five hundred at least forty + + + align:start position:0% +been forty five hundred at least forty +five hundred proposed initial quaint + + align:start position:0% +five hundred proposed initial quaint + + + align:start position:0% +five hundred proposed initial quaint +offerings many of them didn't raise any + + align:start position:0% +offerings many of them didn't raise any + + + align:start position:0% +offerings many of them didn't raise any +money but over 2,000 to 3,000 have + + align:start position:0% +money but over 2,000 to 3,000 have + + + align:start position:0% +money but over 2,000 to 3,000 have +raised money I'm gonna use the three + + align:start position:0% +raised money I'm gonna use the three + + + align:start position:0% +raised money I'm gonna use the three +thousand figure less than half of them + + align:start position:0% +thousand figure less than half of them + + + align:start position:0% +thousand figure less than half of them +are even live today about fifty there's + + align:start position:0% +are even live today about fifty there's + + + align:start position:0% +are even live today about fifty there's +one study that shows that 59 percent + + align:start position:0% +one study that shows that 59 percent + + + align:start position:0% +one study that shows that 59 percent +fail within the first nine months there + + align:start position:0% +fail within the first nine months there + + + align:start position:0% +fail within the first nine months there +are other studies that say between a + + align:start position:0% +are other studies that say between a + + + align:start position:0% +are other studies that say between a +quarter and three quarters or scams + + align:start position:0% +quarter and three quarters or scams + + + align:start position:0% +quarter and three quarters or scams +Christian Catalina here has a study + + align:start position:0% +Christian Catalina here has a study + + + align:start position:0% +Christian Catalina here has a study +which I think is probably the most valid + + align:start position:0% +which I think is probably the most valid + + + align:start position:0% +which I think is probably the most valid +and reliable which says 25 percent of + + align:start position:0% +and reliable which says 25 percent of + + + align:start position:0% +and reliable which says 25 percent of +scams or frauds status has one that says + + align:start position:0% +scams or frauds status has one that says + + + align:start position:0% +scams or frauds status has one that says +80 percent might be I mean it just goes + + align:start position:0% +80 percent might be I mean it just goes + + + align:start position:0% +80 percent might be I mean it just goes +to zero or there's hold that until later + + align:start position:0% +to zero or there's hold that until later + + + align:start position:0% +to zero or there's hold that until later +when we're gonna dig into these in in + + align:start position:0% +when we're gonna dig into these in in + + + align:start position:0% +when we're gonna dig into these in in +the class but broad definition of fails + + align:start position:0% +the class but broad definition of fails + + + align:start position:0% +the class but broad definition of fails +so it's not just technology it means + + align:start position:0% +so it's not just technology it means + + + align:start position:0% +so it's not just technology it means +that you can't even find the website + + align:start position:0% +that you can't even find the website + + + align:start position:0% +that you can't even find the website +anymore they took your money and they + + align:start position:0% +anymore they took your money and they + + + align:start position:0% +anymore they took your money and they +ran or they still have a website but + + align:start position:0% +ran or they still have a website but + + + align:start position:0% +ran or they still have a website but +it's it's it's it's not live there + + align:start position:0% +it's it's it's it's not live there + + + align:start position:0% +it's it's it's it's not live there +doesn't seem like there's a development + + align:start position:0% +doesn't seem like there's a development + + + align:start position:0% +doesn't seem like there's a development +team any longer so multiple definitions + + align:start position:0% +team any longer so multiple definitions + + + align:start position:0% +team any longer so multiple definitions +of failure so that brings us to legal + + align:start position:0% +of failure so that brings us to legal + + + align:start position:0% +of failure so that brings us to legal +issues and as is Larry brings up is his + + align:start position:0% +issues and as is Larry brings up is his + + + align:start position:0% +issues and as is Larry brings up is his +computer let me just introduce our guest + + align:start position:0% +computer let me just introduce our guest + + + align:start position:0% +computer let me just introduce our guest +lecture Larry Lessig who's esteemed + + align:start position:0% +lecture Larry Lessig who's esteemed + + + align:start position:0% +lecture Larry Lessig who's esteemed +Harvard professor + + align:start position:0% +Harvard professor + + + align:start position:0% +Harvard professor +of law he was at Stanford he started + + align:start position:0% +of law he was at Stanford he started + + + align:start position:0% +of law he was at Stanford he started +something called the Internet and a + + align:start position:0% +something called the Internet and a + + + align:start position:0% +something called the Internet and a +center for Internet and Society you + + align:start position:0% +center for Internet and Society you + + + align:start position:0% +center for Internet and Society you +clerked for Justice Scalia so you must + + align:start position:0% +clerked for Justice Scalia so you must + + + align:start position:0% +clerked for Justice Scalia so you must +you must have some real views on what's + + align:start position:0% +you must have some real views on what's + + + align:start position:0% +you must have some real views on what's +going on this week then and this + + align:start position:0% +going on this week then and this + + + align:start position:0% +going on this week then and this +incredible appellate court judge posner + + align:start position:0% +incredible appellate court judge posner + + + align:start position:0% +incredible appellate court judge posner +and Larry also his first of what have + + align:start position:0% +and Larry also his first of what have + + + align:start position:0% +and Larry also his first of what have +you up to 9 or 10 books now but his + + align:start position:0% +you up to 9 or 10 books now but his + + + align:start position:0% +you up to 9 or 10 books now but his +first was the code in the law that I + + align:start position:0% +first was the code in the law that I + + + align:start position:0% +first was the code in the law that I +referenced in our first lecture Larry's + + align:start position:0% +referenced in our first lecture Larry's + + + align:start position:0% +referenced in our first lecture Larry's +going to take it away ok great so I'm + + align:start position:0% +going to take it away ok great so I'm + + + align:start position:0% +going to take it away ok great so I'm +really happy to be able to say that I've + + align:start position:0% +really happy to be able to say that I've + + + align:start position:0% +really happy to be able to say that I've +taught Business School students at MIT I + + align:start position:0% +taught Business School students at MIT I + + + align:start position:0% +taught Business School students at MIT I +mean I you know I'm a tech wannabe but + + align:start position:0% +mean I you know I'm a tech wannabe but + + + align:start position:0% +mean I you know I'm a tech wannabe but +have never been allowed to be officially + + align:start position:0% +have never been allowed to be officially + + + align:start position:0% +have never been allowed to be officially +here so this is exciting + + align:start position:0% +here so this is exciting + + + align:start position:0% +here so this is exciting +um but what I want to do is really + + align:start position:0% +um but what I want to do is really + + + align:start position:0% +um but what I want to do is really +address what I've experienced as + + align:start position:0% +address what I've experienced as + + + align:start position:0% +address what I've experienced as +misperceptions about the nature of the + + align:start position:0% +misperceptions about the nature of the + + + align:start position:0% +misperceptions about the nature of the +law as it might interact with the issues + + align:start position:0% +law as it might interact with the issues + + + align:start position:0% +law as it might interact with the issues +around digital contracts + + align:start position:0% +around digital contracts + + + align:start position:0% +around digital contracts +so I teach contract contract law is one + + align:start position:0% +so I teach contract contract law is one + + + align:start position:0% +so I teach contract contract law is one +of the subjects which I've taught since + + align:start position:0% +of the subjects which I've taught since + + + align:start position:0% +of the subjects which I've taught since +I started teaching and so I want to + + align:start position:0% +I started teaching and so I want to + + + align:start position:0% +I started teaching and so I want to +frame four points for you about how to + + align:start position:0% +frame four points for you about how to + + + align:start position:0% +frame four points for you about how to +think about contract law as it relates + + align:start position:0% +think about contract law as it relates + + + align:start position:0% +think about contract law as it relates +to these potential digital contracts but + + align:start position:0% +to these potential digital contracts but + + + align:start position:0% +to these potential digital contracts but +the first thing to do is just to make + + align:start position:0% +the first thing to do is just to make + + + align:start position:0% +the first thing to do is just to make +sure we understand we're all talking + + align:start position:0% +sure we understand we're all talking + + + align:start position:0% +sure we understand we're all talking +about the same thing okay so here's what + + align:start position:0% +about the same thing okay so here's what + + + align:start position:0% +about the same thing okay so here's what +the core of contract law teaches us + + align:start position:0% +the core of contract law teaches us + + + align:start position:0% +the core of contract law teaches us +contracts our contract is a promise or + + align:start position:0% +contracts our contract is a promise or + + + align:start position:0% +contracts our contract is a promise or +performance given in exchange for a + + align:start position:0% +performance given in exchange for a + + + align:start position:0% +performance given in exchange for a +promise or performance the given in + + align:start position:0% +promise or performance the given in + + + align:start position:0% +promise or performance the given in +exchange for is really critical that's + + align:start position:0% +exchange for is really critical that's + + + align:start position:0% +exchange for is really critical that's +the quid pro quo that sometimes referred + + align:start position:0% +the quid pro quo that sometimes referred + + + align:start position:0% +the quid pro quo that sometimes referred +to as the consideration for the promise + + align:start position:0% +to as the consideration for the promise + + + align:start position:0% +to as the consideration for the promise +but notice here this is mapping out four + + align:start position:0% +but notice here this is mapping out four + + + align:start position:0% +but notice here this is mapping out four +different possibilities you can have a + + align:start position:0% +different possibilities you can have a + + + align:start position:0% +different possibilities you can have a +promise in exchange for a promise I + + align:start position:0% +promise in exchange for a promise I + + + align:start position:0% +promise in exchange for a promise I +promise to pay you $10,000 if you + + align:start position:0% +promise to pay you $10,000 if you + + + align:start position:0% +promise to pay you $10,000 if you +promise to sing an opera for me tomorrow + + align:start position:0% +promise to sing an opera for me tomorrow + + + align:start position:0% +promise to sing an opera for me tomorrow +or it can be promise for a performance I + + align:start position:0% +or it can be promise for a performance I + + + align:start position:0% +or it can be promise for a performance I +promise to pay you Indy five dollars if + + align:start position:0% +promise to pay you Indy five dollars if + + + align:start position:0% +promise to pay you Indy five dollars if +you sing a song for us now + + align:start position:0% +you sing a song for us now + + + align:start position:0% +you sing a song for us now +so it's the performance I want I don't + + align:start position:0% +so it's the performance I want I don't + + + align:start position:0% +so it's the performance I want I don't +want to promise from him because we know + + align:start position:0% +want to promise from him because we know + + + align:start position:0% +want to promise from him because we know +what Andy's promises are worth or it + + align:start position:0% +what Andy's promises are worth or it + + + align:start position:0% +what Andy's promises are worth or it +could be a performance for a promise + + align:start position:0% +could be a performance for a promise + + + align:start position:0% +could be a performance for a promise +I'll sing if you promise to pay me after + + align:start position:0% +I'll sing if you promise to pay me after + + + align:start position:0% +I'll sing if you promise to pay me after +I'm done or the really interesting one + + align:start position:0% +I'm done or the really interesting one + + + align:start position:0% +I'm done or the really interesting one +for our purposes is a performance for a + + align:start position:0% +for our purposes is a performance for a + + + align:start position:0% +for our purposes is a performance for a +performance I'll sing if you pay me + + align:start position:0% +performance I'll sing if you pay me + + + align:start position:0% +performance I'll sing if you pay me +$5,000 I didn't want to promise from you + + align:start position:0% +$5,000 I didn't want to promise from you + + + align:start position:0% +$5,000 I didn't want to promise from you +because I don't trust you your business + + align:start position:0% +because I don't trust you your business + + + align:start position:0% +because I don't trust you your business +school students right so I I just want + + align:start position:0% +school students right so I I just want + + + align:start position:0% +school students right so I I just want +the money but I'm not promising to do + + align:start position:0% +the money but I'm not promising to do + + + align:start position:0% +the money but I'm not promising to do +anything I'm actually going to do + + align:start position:0% +anything I'm actually going to do + + + align:start position:0% +anything I'm actually going to do +something for you now that's the one + + align:start position:0% +something for you now that's the one + + + align:start position:0% +something for you now that's the one +that we're gonna think about in the + + align:start position:0% +that we're gonna think about in the + + + align:start position:0% +that we're gonna think about in the +context of digital contracts and they're + + align:start position:0% + + + + align:start position:0% + +actually what's gonna make three points + + align:start position:0% +actually what's gonna make three points + + + align:start position:0% +actually what's gonna make three points +but then I decided I was gonna make four + + align:start position:0% +but then I decided I was gonna make four + + + align:start position:0% +but then I decided I was gonna make four +so let me fix that for points about + + align:start position:0% +so let me fix that for points about + + + align:start position:0% +so let me fix that for points about +contracts so the first point about + + align:start position:0% +contracts so the first point about + + + align:start position:0% +contracts so the first point about +contracts to think about this case all + + align:start position:0% +contracts to think about this case all + + + align:start position:0% +contracts to think about this case all +right here's a it's not quite digital + + align:start position:0% +right here's a it's not quite digital + + + align:start position:0% +right here's a it's not quite digital +but it's a physical contract machine in + + align:start position:0% +but it's a physical contract machine in + + + align:start position:0% +but it's a physical contract machine in +the sense that it's a performance for a + + align:start position:0% +the sense that it's a performance for a + + + align:start position:0% +the sense that it's a performance for a +performance if you drop a dime into this + + align:start position:0% +performance if you drop a dime into this + + + align:start position:0% +performance if you drop a dime into this +machine then out will come dr. pepper or + + align:start position:0% +machine then out will come dr. pepper or + + + align:start position:0% +machine then out will come dr. pepper or +something else okay so there's no + + align:start position:0% +something else okay so there's no + + + align:start position:0% +something else okay so there's no +promises involved and we understand + + align:start position:0% +promises involved and we understand + + + align:start position:0% +promises involved and we understand +there's a mechanism that's to produce + + align:start position:0% +there's a mechanism that's to produce + + + align:start position:0% +there's a mechanism that's to produce +this result and obviously these have + + align:start position:0% +this result and obviously these have + + + align:start position:0% +this result and obviously these have +been here for a long time and these + + align:start position:0% +been here for a long time and these + + + align:start position:0% +been here for a long time and these +mechanisms provide real value because to + + align:start position:0% +mechanisms provide real value because to + + + align:start position:0% +mechanisms provide real value because to +the extent you don't have to hire + + align:start position:0% +the extent you don't have to hire + + + align:start position:0% +the extent you don't have to hire +somebody to stand there handing out dr. + + align:start position:0% +somebody to stand there handing out dr. + + + align:start position:0% +somebody to stand there handing out dr. +peppers you can lower the cost of + + align:start position:0% +peppers you can lower the cost of + + + align:start position:0% +peppers you can lower the cost of +delivering dr. peppers and increase the + + align:start position:0% +delivering dr. peppers and increase the + + + align:start position:0% +delivering dr. peppers and increase the +market for dr. peppers so this is the + + align:start position:0% +market for dr. peppers so this is the + + + align:start position:0% +market for dr. peppers so this is the +motivation lower the transaction cost of + + align:start position:0% +motivation lower the transaction cost of + + + align:start position:0% +motivation lower the transaction cost of +engaging in a particular kind of + + align:start position:0% +engaging in a particular kind of + + + align:start position:0% +engaging in a particular kind of +contract which is performance for + + align:start position:0% +contract which is performance for + + + align:start position:0% +contract which is performance for +performance now when you look at that + + align:start position:0% +performance now when you look at that + + + align:start position:0% +performance now when you look at that +contract you should ask yourself what + + align:start position:0% +contract you should ask yourself what + + + align:start position:0% +contract you should ask yourself what +are the terms of this contract right so + + align:start position:0% +are the terms of this contract right so + + + align:start position:0% +are the terms of this contract right so +some of them are expressed and they're + + align:start position:0% +some of them are expressed and they're + + + align:start position:0% +some of them are expressed and they're +pretty obvious so this says 10 cents it + + align:start position:0% +pretty obvious so this says 10 cents it + + + align:start position:0% +pretty obvious so this says 10 cents it +says if you pay 10 cents there you will + + align:start position:0% +says if you pay 10 cents there you will + + + align:start position:0% +says if you pay 10 cents there you will +get the dr. pepper well that's what you + + align:start position:0% +get the dr. pepper well that's what you + + + align:start position:0% +get the dr. pepper well that's what you +kind of expect is a great cartoon I + + align:start position:0% +kind of expect is a great cartoon I + + + align:start position:0% +kind of expect is a great cartoon I +couldn't find where you come to a + + align:start position:0% +couldn't find where you come to a + + + align:start position:0% +couldn't find where you come to a +machine it says deposit 50 cents + + align:start position:0% +machine it says deposit 50 cents + + + align:start position:0% +machine it says deposit 50 cents +positive 50 cents and the light comes on + + align:start position:0% +positive 50 cents and the light comes on + + + align:start position:0% +positive 50 cents and the light comes on +thank you very much right so you think + + align:start position:0% +thank you very much right so you think + + + align:start position:0% +thank you very much right so you think +you know what this contract is but you + + align:start position:0% +you know what this contract is but you + + + align:start position:0% +you know what this contract is but you +know that the joke is to Vince that + + align:start position:0% +know that the joke is to Vince that + + + align:start position:0% +know that the joke is to Vince that +maybe you don't know what that contract + + align:start position:0% +maybe you don't know what that contract + + + align:start position:0% +maybe you don't know what that contract +is but but the Express terms are the one + + align:start position:0% +is but but the Express terms are the one + + + align:start position:0% +is but but the Express terms are the one +we expect go with the statement to the + + align:start position:0% +we expect go with the statement to the + + + align:start position:0% +we expect go with the statement to the +machine but then there's a whole bunch + + align:start position:0% +machine but then there's a whole bunch + + + align:start position:0% +machine but then there's a whole bunch +of implied terms so one implied term if + + align:start position:0% +of implied terms so one implied term if + + + align:start position:0% +of implied terms so one implied term if +this machine is in the United States is + + align:start position:0% +this machine is in the United States is + + + align:start position:0% +this machine is in the United States is +that when you take the dr. pepper out + + align:start position:0% +that when you take the dr. pepper out + + + align:start position:0% +that when you take the dr. pepper out +and you drink it it's actually going to + + align:start position:0% +and you drink it it's actually going to + + + align:start position:0% +and you drink it it's actually going to +be safe to drink + + align:start position:0% +be safe to drink + + + align:start position:0% +be safe to drink +it's actually gonna be dr. pepper it's + + align:start position:0% +it's actually gonna be dr. pepper it's + + + align:start position:0% +it's actually gonna be dr. pepper it's +actually not going to make you sick and + + align:start position:0% +actually not going to make you sick and + + + align:start position:0% +actually not going to make you sick and +none of that is written on the dr. + + align:start position:0% +none of that is written on the dr. + + + align:start position:0% +none of that is written on the dr. +pepper machine that's instead a term a + + align:start position:0% +pepper machine that's instead a term a + + + align:start position:0% +pepper machine that's instead a term a +contract term that gets created by the + + align:start position:0% +contract term that gets created by the + + + align:start position:0% +contract term that gets created by the +law and gets imposed or wrapped around + + align:start position:0% +law and gets imposed or wrapped around + + + align:start position:0% +law and gets imposed or wrapped around +the delivery of that drink + + align:start position:0% +the delivery of that drink + + + align:start position:0% +the delivery of that drink +okay that's your first point the second + + align:start position:0% +okay that's your first point the second + + + align:start position:0% +okay that's your first point the second +point that is to think more about what + + align:start position:0% +point that is to think more about what + + + align:start position:0% +point that is to think more about what +these implied terms imply because if + + align:start position:0% +these implied terms imply because if + + + align:start position:0% +these implied terms imply because if +these implied terms are implied by a + + align:start position:0% +these implied terms are implied by a + + + align:start position:0% +these implied terms are implied by a +legal system then that means the legal + + align:start position:0% +legal system then that means the legal + + + align:start position:0% +legal system then that means the legal +system has an interest in your contract + + align:start position:0% +system has an interest in your contract + + + align:start position:0% +system has an interest in your contract +legal system is not on that + + align:start position:0% +legal system is not on that + + + align:start position:0% +legal system is not on that +disinterested in your contract so we + + align:start position:0% +disinterested in your contract so we + + + align:start position:0% +disinterested in your contract so we +should always think that our contract is + + align:start position:0% +should always think that our contract is + + + align:start position:0% +should always think that our contract is +going to have two parties we call them + + align:start position:0% +going to have two parties we call them + + + align:start position:0% +going to have two parties we call them +the promise or and the promisee you know + + align:start position:0% +the promise or and the promisee you know + + + align:start position:0% +the promise or and the promisee you know +I've told you we've had contracts it can + + align:start position:0% +I've told you we've had contracts it can + + + align:start position:0% +I've told you we've had contracts it can +be performance the performance or isn't + + align:start position:0% +be performance the performance or isn't + + + align:start position:0% +be performance the performance or isn't +really a word but let's just say promise + + align:start position:0% +really a word but let's just say promise + + + align:start position:0% +really a word but let's just say promise +Oram promise e but there's always a + + align:start position:0% +Oram promise e but there's always a + + + align:start position:0% +Oram promise e but there's always a +third party which is the state who is in + + align:start position:0% +third party which is the state who is in + + + align:start position:0% +third party which is the state who is in +the middle of the contract in the sense + + align:start position:0% +the middle of the contract in the sense + + + align:start position:0% +the middle of the contract in the sense +that the states will police many + + align:start position:0% +that the states will police many + + + align:start position:0% +that the states will police many +contracts and decide whether they lie to + + align:start position:0% +contracts and decide whether they lie to + + + align:start position:0% +contracts and decide whether they lie to +the state likes the contract or not I + + align:start position:0% +the state likes the contract or not I + + + align:start position:0% +the state likes the contract or not I +mean if the state doesn't like the + + align:start position:0% +mean if the state doesn't like the + + + align:start position:0% +mean if the state doesn't like the +contract then the state won't enforce + + align:start position:0% +contract then the state won't enforce + + + align:start position:0% +contract then the state won't enforce +the contract or the state might actually + + align:start position:0% +the contract or the state might actually + + + align:start position:0% +the contract or the state might actually +punish you because of the contract so + + align:start position:0% +punish you because of the contract so + + + align:start position:0% +punish you because of the contract so +for example the state cares about the + + align:start position:0% +for example the state cares about the + + + align:start position:0% +for example the state cares about the +kinds of contracts you can have + + align:start position:0% +kinds of contracts you can have + + + align:start position:0% +kinds of contracts you can have +contracts for the sale of tables you + + align:start position:0% +contracts for the sale of tables you + + + align:start position:0% +contracts for the sale of tables you +can't have contracts for the sale of the + + align:start position:0% +can't have contracts for the sale of the + + + align:start position:0% +can't have contracts for the sale of the +people though you can sell dogs for + + align:start position:0% +people though you can sell dogs for + + + align:start position:0% +people though you can sell dogs for +reasons I can't understand but you know + + align:start position:0% +reasons I can't understand but you know + + + align:start position:0% +reasons I can't understand but you know +the point is we are deciding which type + + align:start position:0% +the point is we are deciding which type + + + align:start position:0% +the point is we are deciding which type +of things can be sold and which kind of + + align:start position:0% +of things can be sold and which kind of + + + align:start position:0% +of things can be sold and which kind of +things can't be sold the state cares + + align:start position:0% +things can't be sold the state cares + + + align:start position:0% +things can't be sold the state cares +about the effect of the contract + + align:start position:0% +about the effect of the contract + + + align:start position:0% +about the effect of the contract +if the contract is to render your + + align:start position:0% +if the contract is to render your + + + align:start position:0% +if the contract is to render your +corporation vulnerable to bankruptcy the + + align:start position:0% +corporation vulnerable to bankruptcy the + + + align:start position:0% +corporation vulnerable to bankruptcy the +state might have an interest in deciding + + align:start position:0% +state might have an interest in deciding + + + align:start position:0% +state might have an interest in deciding +whether that contract will be enforced + + align:start position:0% +whether that contract will be enforced + + + align:start position:0% +whether that contract will be enforced +or not or whether it will be allowed or + + align:start position:0% +or not or whether it will be allowed or + + + align:start position:0% +or not or whether it will be allowed or +not whether it's permissible under + + align:start position:0% +not whether it's permissible under + + + align:start position:0% +not whether it's permissible under +bankruptcy laws to engage in that + + align:start position:0% +bankruptcy laws to engage in that + + + align:start position:0% +bankruptcy laws to engage in that +contract because of the risk that it's + + align:start position:0% +contract because of the risk that it's + + + align:start position:0% +contract because of the risk that it's +going to create it's going to care about + + align:start position:0% +going to create it's going to care about + + + align:start position:0% +going to create it's going to care about +the terms of the contract so if you're + + align:start position:0% +the terms of the contract so if you're + + + align:start position:0% +the terms of the contract so if you're +selling your labor in a state with a + + align:start position:0% +selling your labor in a state with a + + + align:start position:0% +selling your labor in a state with a +minimum wage law the state's gonna care + + align:start position:0% +minimum wage law the state's gonna care + + + align:start position:0% +minimum wage law the state's gonna care +does the term that specifies your wage + + align:start position:0% +does the term that specifies your wage + + + align:start position:0% +does the term that specifies your wage +equal or exceed the minimum wage and the + + align:start position:0% +equal or exceed the minimum wage and the + + + align:start position:0% +equal or exceed the minimum wage and the +state's gonna obviously care the most + + align:start position:0% +state's gonna obviously care the most + + + align:start position:0% +state's gonna obviously care the most +important thing for the state is whether + + align:start position:0% +important thing for the state is whether + + + align:start position:0% +important thing for the state is whether +and how the state tax is the transaction + + align:start position:0% +and how the state tax is the transaction + + + align:start position:0% +and how the state tax is the transaction +in the contract so when does it tax the + + align:start position:0% +in the contract so when does it tax the + + + align:start position:0% +in the contract so when does it tax the +transaction of the contract does it you + + align:start position:0% +transaction of the contract does it you + + + align:start position:0% +transaction of the contract does it you +know what is the event that's going to + + align:start position:0% +know what is the event that's going to + + + align:start position:0% +know what is the event that's going to +manifest it and of course the contract + + align:start position:0% +manifest it and of course the contract + + + align:start position:0% +manifest it and of course the contract +can try to play with that to sort of + + align:start position:0% +can try to play with that to sort of + + + align:start position:0% +can try to play with that to sort of +deal with whether it will be taxed in + + align:start position:0% +deal with whether it will be taxed in + + + align:start position:0% +deal with whether it will be taxed in +the state will care about how the + + align:start position:0% +the state will care about how the + + + align:start position:0% +the state will care about how the +contract deals with okay so the point is + + align:start position:0% +contract deals with okay so the point is + + + align:start position:0% +contract deals with okay so the point is +to to fight against the first real bias + + align:start position:0% +to to fight against the first real bias + + + align:start position:0% +to to fight against the first real bias +then especially non it was let's say + + align:start position:0% +then especially non it was let's say + + + align:start position:0% +then especially non it was let's say +tech people maybe business tech people + + align:start position:0% +tech people maybe business tech people + + + align:start position:0% +tech people maybe business tech people +bringing to the idea of contract law + + align:start position:0% +bringing to the idea of contract law + + + align:start position:0% +bringing to the idea of contract law +which is that contracts are not about + + align:start position:0% +which is that contracts are not about + + + align:start position:0% +which is that contracts are not about +the state they're about private parties + + align:start position:0% +the state they're about private parties + + + align:start position:0% +the state they're about private parties +that's not true they're about private + + align:start position:0% +that's not true they're about private + + + align:start position:0% +that's not true they're about private +parties and the state and the state is + + align:start position:0% +parties and the state and the state is + + + align:start position:0% +parties and the state and the state is +always going to be there now so if I say + + align:start position:0% +always going to be there now so if I say + + + align:start position:0% +always going to be there now so if I say +to you so I'm trying to sell my parents + + align:start position:0% +to you so I'm trying to sell my parents + + + align:start position:0% +to you so I'm trying to sell my parents +house I can't sell it so if they say to + + align:start position:0% +house I can't sell it so if they say to + + + align:start position:0% +house I can't sell it so if they say to +you I'll offer you $10,000 to anyone who + + align:start position:0% +you I'll offer you $10,000 to anyone who + + + align:start position:0% +you I'll offer you $10,000 to anyone who +will burn down my parents house you're + + align:start position:0% +will burn down my parents house you're + + + align:start position:0% +will burn down my parents house you're +trying to accept that contract yeah + + align:start position:0% +trying to accept that contract yeah + + + align:start position:0% +trying to accept that contract yeah +you're raising your hand so you're + + align:start position:0% +you're raising your hand so you're + + + align:start position:0% +you're raising your hand so you're +trying to accept I want to say + + align:start position:0% +trying to accept I want to say + + + align:start position:0% +trying to accept I want to say +officially it's a joke so nobody gets + + align:start position:0% +officially it's a joke so nobody gets + + + align:start position:0% +officially it's a joke so nobody gets +any uncertainty about this now you can + + align:start position:0% +any uncertainty about this now you can + + + align:start position:0% +any uncertainty about this now you can +ask a question because I didn't want you + + align:start position:0% +ask a question because I didn't want you + + + align:start position:0% +ask a question because I didn't want you +to accept because if you accepted my + + align:start position:0% +to accept because if you accepted my + + + align:start position:0% +to accept because if you accepted my +offer then that's it I'm stuck so now + + align:start position:0% +offer then that's it I'm stuck so now + + + align:start position:0% +offer then that's it I'm stuck so now +it's clear it's not really an offer and + + align:start position:0% +it's clear it's not really an offer and + + + align:start position:0% +it's clear it's not really an offer and +I can ask you a question + + align:start position:0% +I can ask you a question + + + align:start position:0% +I can ask you a question +so they said contracts cannot be between + + align:start position:0% +so they said contracts cannot be between + + + align:start position:0% +so they said contracts cannot be between +two parties they have to be between two + + align:start position:0% +two parties they have to be between two + + + align:start position:0% +two parties they have to be between two +parties in the state let me see it more + + align:start position:0% +parties in the state let me see it more + + + align:start position:0% +parties in the state let me see it more +clearly contracts always have the state + + align:start position:0% +clearly contracts always have the state + + + align:start position:0% +clearly contracts always have the state +present so it's always between two + + align:start position:0% +present so it's always between two + + + align:start position:0% +present so it's always between two +parties or three parties or four so you + + align:start position:0% +parties or three parties or four so you + + + align:start position:0% +parties or three parties or four so you +and I enter into a contract not this one + + align:start position:0% +and I enter into a contract not this one + + + align:start position:0% +and I enter into a contract not this one +but another one + + align:start position:0% +but another one + + + align:start position:0% +but another one +but the state is in the room and + + align:start position:0% +but the state is in the room and + + + align:start position:0% +but the state is in the room and +deciding whether the states you know in + + align:start position:0% +deciding whether the states you know in + + + align:start position:0% +deciding whether the states you know in +the states gonna allow the contract to + + align:start position:0% +the states gonna allow the contract to + + + align:start position:0% +the states gonna allow the contract to +happen so most contracts the state + + align:start position:0% +happen so most contracts the state + + + align:start position:0% +happen so most contracts the state +doesn't care about but some contracts + + align:start position:0% +doesn't care about but some contracts + + + align:start position:0% +doesn't care about but some contracts +gonna say hell no we're not gonna allow + + align:start position:0% +gonna say hell no we're not gonna allow + + + align:start position:0% +gonna say hell no we're not gonna allow +it like this one you know if you didn't + + align:start position:0% +it like this one you know if you didn't + + + align:start position:0% +it like this one you know if you didn't +get that noticed it was a joke and you + + align:start position:0% +get that noticed it was a joke and you + + + align:start position:0% +get that noticed it was a joke and you +thought I was serious and you went you + + align:start position:0% +thought I was serious and you went you + + + align:start position:0% +thought I was serious and you went you +burned down my parents house so that we + + align:start position:0% +burned down my parents house so that we + + + align:start position:0% +burned down my parents house so that we +could get the insurance and not have to + + align:start position:0% +could get the insurance and not have to + + + align:start position:0% +could get the insurance and not have to +worry about selling the house and then + + align:start position:0% +worry about selling the house and then + + + align:start position:0% +worry about selling the house and then +you came to me and you said okay pay the + + align:start position:0% +you came to me and you said okay pay the + + + align:start position:0% +you came to me and you said okay pay the +$10,000 and I said it was an obvious + + align:start position:0% +$10,000 and I said it was an obvious + + + align:start position:0% +$10,000 and I said it was an obvious +joke and you went to a court and you + + align:start position:0% +joke and you went to a court and you + + + align:start position:0% +joke and you went to a court and you +said force Lessig to pay the $10,000 the + + align:start position:0% +said force Lessig to pay the $10,000 the + + + align:start position:0% +said force Lessig to pay the $10,000 the +Corbis say this is an illegal contract I + + align:start position:0% +Corbis say this is an illegal contract I + + + align:start position:0% +Corbis say this is an illegal contract I +come enforce this contract so my point + + align:start position:0% +come enforce this contract so my point + + + align:start position:0% +come enforce this contract so my point +is the state in a certain sense is the + + align:start position:0% +is the state in a certain sense is the + + + align:start position:0% +is the state in a certain sense is the +sense sensor of this contract the state + + align:start position:0% +sense sensor of this contract the state + + + align:start position:0% +sense sensor of this contract the state +is in the room when we make this + + align:start position:0% +is in the room when we make this + + + align:start position:0% +is in the room when we make this +contract and the state's judgment about + + align:start position:0% +contract and the state's judgment about + + + align:start position:0% +contract and the state's judgment about +it will decide whether we enforce it or + + align:start position:0% +it will decide whether we enforce it or + + + align:start position:0% +it will decide whether we enforce it or +not is that clear I'm not saying the + + align:start position:0% +not is that clear I'm not saying the + + + align:start position:0% +not is that clear I'm not saying the +state is technically signing the + + align:start position:0% +state is technically signing the + + + align:start position:0% +state is technically signing the +document but I'm getting you to + + align:start position:0% +document but I'm getting you to + + + align:start position:0% +document but I'm getting you to +recognize the fact that the contract is + + align:start position:0% +recognize the fact that the contract is + + + align:start position:0% +recognize the fact that the contract is +valuable to the extent it's enforceable + + align:start position:0% +valuable to the extent it's enforceable + + + align:start position:0% +valuable to the extent it's enforceable +and the state is the essential agent in + + align:start position:0% +and the state is the essential agent in + + + align:start position:0% +and the state is the essential agent in +enforcement in the that's my question + + align:start position:0% +enforcement in the that's my question + + + align:start position:0% +enforcement in the that's my question +because it seems like nowadays we can + + align:start position:0% +because it seems like nowadays we can + + + align:start position:0% +because it seems like nowadays we can +have contracts where the enforcement is + + align:start position:0% +have contracts where the enforcement is + + + align:start position:0% +have contracts where the enforcement is +not a contract that says hey if you can + + align:start position:0% +not a contract that says hey if you can + + + align:start position:0% +not a contract that says hey if you can +factor this number I'll give you 10 and + + align:start position:0% +factor this number I'll give you 10 and + + + align:start position:0% +factor this number I'll give you 10 and +what I started with when I was showing + + align:start position:0% +what I started with when I was showing + + + align:start position:0% +what I started with when I was showing +you this picture was to say actually + + align:start position:0% +you this picture was to say actually + + + align:start position:0% +you this picture was to say actually +that's been true for a while right so in + + align:start position:0% +that's been true for a while right so in + + + align:start position:0% +that's been true for a while right so in +what sense is the state here well the + + align:start position:0% +what sense is the state here well the + + + align:start position:0% +what sense is the state here well the +state is here if you know when you put + + align:start position:0% +state is here if you know when you put + + + align:start position:0% +state is here if you know when you put +the dime in you get the drink out and + + align:start position:0% +the dime in you get the drink out and + + + align:start position:0% +the dime in you get the drink out and +the drink doesn't have dr. pepper but it + + align:start position:0% +the drink doesn't have dr. pepper but it + + + align:start position:0% +the drink doesn't have dr. pepper but it +has gasoline in it + + align:start position:0% +has gasoline in it + + + align:start position:0% +has gasoline in it +you know the state would come in and say + + align:start position:0% +you know the state would come in and say + + + align:start position:0% +you know the state would come in and say +well you've breached the implied term + + align:start position:0% +well you've breached the implied term + + + align:start position:0% +well you've breached the implied term +that said that this was safe to consume + + align:start position:0% +that said that this was safe to consume + + + align:start position:0% +that said that this was safe to consume +so the state is in this contract too and + + align:start position:0% +so the state is in this contract too and + + + align:start position:0% +so the state is in this contract too and +and so what I'm trying to lead to I'll + + align:start position:0% +and so what I'm trying to lead to I'll + + + align:start position:0% +and so what I'm trying to lead to I'll +get to the place where we say is there + + align:start position:0% +get to the place where we say is there + + + align:start position:0% +get to the place where we say is there +ever a place where the state is not + + align:start position:0% +ever a place where the state is not + + + align:start position:0% +ever a place where the state is not +there which is what I think your you + + align:start position:0% +there which is what I think your you + + + align:start position:0% +there which is what I think your you +know your blockchain like invocation is + + align:start position:0% +know your blockchain like invocation is + + + align:start position:0% +know your blockchain like invocation is +so that's that's a question we're going + + align:start position:0% +so that's that's a question we're going + + + align:start position:0% +so that's that's a question we're going +to get here's another contract + + align:start position:0% + + + + align:start position:0% + +we'll offer you $50,000 to lobby + + align:start position:0% +we'll offer you $50,000 to lobby + + + align:start position:0% +we'll offer you $50,000 to lobby +Congress to pass HR 102 this contract + + align:start position:0% +Congress to pass HR 102 this contract + + + align:start position:0% +Congress to pass HR 102 this contract +looks pretty normal to us can imagine + + align:start position:0% +looks pretty normal to us can imagine + + + align:start position:0% +looks pretty normal to us can imagine +lobbyists have a contract like this all + + align:start position:0% +lobbyists have a contract like this all + + + align:start position:0% +lobbyists have a contract like this all +the time in fact in the middle of the + + align:start position:0% +the time in fact in the middle of the + + + align:start position:0% +the time in fact in the middle of the +19th century the Supreme Court ruled + + align:start position:0% +19th century the Supreme Court ruled + + + align:start position:0% +19th century the Supreme Court ruled +this contract was an illegal contract + + align:start position:0% +this contract was an illegal contract + + + align:start position:0% +this contract was an illegal contract +you weren't allowed to hire people to + + align:start position:0% +you weren't allowed to hire people to + + + align:start position:0% +you weren't allowed to hire people to +lobby Congress right so again the + + align:start position:0% +lobby Congress right so again the + + + align:start position:0% +lobby Congress right so again the +background norm of what is appropriate + + align:start position:0% +background norm of what is appropriate + + + align:start position:0% +background norm of what is appropriate +or not for the contract controlled what + + align:start position:0% +or not for the contract controlled what + + + align:start position:0% +or not for the contract controlled what +type of contracting was allowed okay so + + align:start position:0% +type of contracting was allowed okay so + + + align:start position:0% +type of contracting was allowed okay so +so that's about the type of contracts + + align:start position:0% +so that's about the type of contracts + + + align:start position:0% +so that's about the type of contracts +but then think about the terms of + + align:start position:0% +but then think about the terms of + + + align:start position:0% +but then think about the terms of +contract and so I want to now I want to + + align:start position:0% +contract and so I want to now I want to + + + align:start position:0% +contract and so I want to now I want to +get you to recognize the way in which + + align:start position:0% +get you to recognize the way in which + + + align:start position:0% +get you to recognize the way in which +the terms that the law wants a contract + + align:start position:0% +the terms that the law wants a contract + + + align:start position:0% +the terms that the law wants a contract +to have can be defeated or not by + + align:start position:0% +to have can be defeated or not by + + + align:start position:0% +to have can be defeated or not by +technology and the way I'm going to get + + align:start position:0% +technology and the way I'm going to get + + + align:start position:0% +technology and the way I'm going to get +you to think about that is to think + + align:start position:0% +you to think about that is to think + + + align:start position:0% +you to think about that is to think +about not contract law but something + + align:start position:0% +about not contract law but something + + + align:start position:0% +about not contract law but something +that will create the intuitions I want + + align:start position:0% +that will create the intuitions I want + + + align:start position:0% +that will create the intuitions I want +you to think about copyright law + + align:start position:0% +you to think about copyright law + + + align:start position:0% +you to think about copyright law +everybody knows so copyright law is a + + align:start position:0% +everybody knows so copyright law is a + + + align:start position:0% +everybody knows so copyright law is a +basic contract with the state where the + + align:start position:0% +basic contract with the state where the + + + align:start position:0% +basic contract with the state where the +state says if you create something then + + align:start position:0% +state says if you create something then + + + align:start position:0% +state says if you create something then +you're gonna get an exclusive right to + + align:start position:0% +you're gonna get an exclusive right to + + + align:start position:0% +you're gonna get an exclusive right to +it or exclusive rights a set of Rights + + align:start position:0% +it or exclusive rights a set of Rights + + + align:start position:0% +it or exclusive rights a set of Rights +the occlusive right to copy is whose + + align:start position:0% +the occlusive right to copy is whose + + + align:start position:0% +the occlusive right to copy is whose +right to sell it skews the right to make + + align:start position:0% +right to sell it skews the right to make + + + align:start position:0% +right to sell it skews the right to make +derivative works of it for a period of + + align:start position:0% +derivative works of it for a period of + + + align:start position:0% +derivative works of it for a period of +time and in America right now that's + + align:start position:0% +time and in America right now that's + + + align:start position:0% +time and in America right now that's +your life Plus 70 years subject to fair + + align:start position:0% +your life Plus 70 years subject to fair + + + align:start position:0% +your life Plus 70 years subject to fair +use meaning the law says you can't + + align:start position:0% +use meaning the law says you can't + + + align:start position:0% +use meaning the law says you can't +control every use of my copyrighted work + + align:start position:0% +control every use of my copyrighted work + + + align:start position:0% +control every use of my copyrighted work +if you want to take a book of mine and + + align:start position:0% +if you want to take a book of mine and + + + align:start position:0% +if you want to take a book of mine and +quote a section and write a review that + + align:start position:0% +quote a section and write a review that + + + align:start position:0% +quote a section and write a review that +says see how idiotic Lessig is you can + + align:start position:0% +says see how idiotic Lessig is you can + + + align:start position:0% +says see how idiotic Lessig is you can +do that and I can't wrap the book in a + + align:start position:0% +do that and I can't wrap the book in a + + + align:start position:0% +do that and I can't wrap the book in a +contract that says you're not allowed to + + align:start position:0% +contract that says you're not allowed to + + + align:start position:0% +contract that says you're not allowed to +quote it for purposes of criticizing I'm + + align:start position:0% +quote it for purposes of criticizing I'm + + + align:start position:0% +quote it for purposes of criticizing I'm +just not allowed to do so copyright law + + align:start position:0% +just not allowed to do so copyright law + + + align:start position:0% +just not allowed to do so copyright law +kind of imagined this bundle of Rights + + align:start position:0% +kind of imagined this bundle of Rights + + + align:start position:0% +kind of imagined this bundle of Rights +that it was offering but now imagine + + align:start position:0% +that it was offering but now imagine + + + align:start position:0% +that it was offering but now imagine +something like called DRM digital rights + + align:start position:0% +something like called DRM digital rights + + + align:start position:0% +something like called DRM digital rights +management DRM is a set of code that we + + align:start position:0% +management DRM is a set of code that we + + + align:start position:0% +management DRM is a set of code that we +can wrap copyrighted material in in the + + align:start position:0% +can wrap copyrighted material in in the + + + align:start position:0% +can wrap copyrighted material in in the +process of making it available to others + + align:start position:0% +process of making it available to others + + + align:start position:0% +process of making it available to others +networks and whatever else it's pretty + + align:start position:0% +networks and whatever else it's pretty + + + align:start position:0% +networks and whatever else it's pretty +trivial to see the way DRM could in + + align:start position:0% +trivial to see the way DRM could in + + + align:start position:0% +trivial to see the way DRM could in +effect destroy the limitations on the + + align:start position:0% +effect destroy the limitations on the + + + align:start position:0% +effect destroy the limitations on the +term you know you can wrap it encrypt it + + align:start position:0% +term you know you can wrap it encrypt it + + + align:start position:0% +term you know you can wrap it encrypt it +make it so that my ability to control it + + align:start position:0% +make it so that my ability to control it + + + align:start position:0% +make it so that my ability to control it +will be my ability to control it you + + align:start position:0% +will be my ability to control it you + + + align:start position:0% +will be my ability to control it you +know concept can see Vuli as long as + + align:start position:0% +know concept can see Vuli as long as + + + align:start position:0% +know concept can see Vuli as long as +machines are running you know if it's a + + align:start position:0% +machines are running you know if it's a + + + align:start position:0% +machines are running you know if it's a +Microsoft based system four years later + + align:start position:0% +Microsoft based system four years later + + + align:start position:0% +Microsoft based system four years later +it won't be workable but the point is in + + align:start position:0% +it won't be workable but the point is in + + + align:start position:0% +it won't be workable but the point is in +principle it could be forever + + align:start position:0% +principle it could be forever + + + align:start position:0% +principle it could be forever +same thing with fair use you can imagine + + align:start position:0% +same thing with fair use you can imagine + + + align:start position:0% +same thing with fair use you can imagine +it being wrapped in a way that disables + + align:start position:0% +it being wrapped in a way that disables + + + align:start position:0% +it being wrapped in a way that disables +the capacity to engage in fair use so I + + align:start position:0% +the capacity to engage in fair use so I + + + align:start position:0% +the capacity to engage in fair use so I +was a stunt you know I make tons of + + align:start position:0% +was a stunt you know I make tons of + + + align:start position:0% +was a stunt you know I make tons of +presentations all the time where I need + + align:start position:0% +presentations all the time where I need + + + align:start position:0% +presentations all the time where I need +to capture video and I was astonished to + + align:start position:0% +to capture video and I was astonished to + + + align:start position:0% +to capture video and I was astonished to +discover the latest round of this + + align:start position:0% +discover the latest round of this + + + align:start position:0% +discover the latest round of this +operating system basically makes it + + align:start position:0% +operating system basically makes it + + + align:start position:0% +operating system basically makes it +incredibly difficult to rip video for + + align:start position:0% +incredibly difficult to rip video for + + + align:start position:0% +incredibly difficult to rip video for +the purpose of capturing even two + + align:start position:0% +the purpose of capturing even two + + + align:start position:0% +the purpose of capturing even two +seconds of it so if you have a video + + align:start position:0% +seconds of it so if you have a video + + + align:start position:0% +seconds of it so if you have a video +program that is capturing your screen + + align:start position:0% +program that is capturing your screen + + + align:start position:0% +program that is capturing your screen +that this operating system will now + + align:start position:0% +that this operating system will now + + + align:start position:0% +that this operating system will now +disable it for any period of time that + + align:start position:0% +disable it for any period of time that + + + align:start position:0% +disable it for any period of time that +you're trying to capture the screen like + + align:start position:0% +you're trying to capture the screen like + + + align:start position:0% +you're trying to capture the screen like +they've built the technology so that now + + align:start position:0% +they've built the technology so that now + + + align:start position:0% +they've built the technology so that now +there is no capacity technical capacity + + align:start position:0% +there is no capacity technical capacity + + + align:start position:0% +there is no capacity technical capacity +to engage in fair use of copyrighted + + align:start position:0% +to engage in fair use of copyrighted + + + align:start position:0% +to engage in fair use of copyrighted +material on the Apple platform now you + + align:start position:0% +material on the Apple platform now you + + + align:start position:0% +material on the Apple platform now you +might say why should they be allowed to + + align:start position:0% +might say why should they be allowed to + + + align:start position:0% +might say why should they be allowed to +do that if the law intended that the + + align:start position:0% +do that if the law intended that the + + + align:start position:0% +do that if the law intended that the +contract gives you the free use of fair + + align:start position:0% +contract gives you the free use of fair + + + align:start position:0% +contract gives you the free use of fair +use why should they be allowed to do + + align:start position:0% +use why should they be allowed to do + + + align:start position:0% +use why should they be allowed to do +that but that's the battle that's been + + align:start position:0% +that but that's the battle that's been + + + align:start position:0% +that but that's the battle that's been +going on about DRM ever since the + + align:start position:0% +going on about DRM ever since the + + + align:start position:0% +going on about DRM ever since the +beginning of the internet on the + + align:start position:0% +beginning of the internet on the + + + align:start position:0% +beginning of the internet on the +beginning of copyright at work on the + + align:start position:0% +beginning of copyright at work on the + + + align:start position:0% +beginning of copyright at work on the +internet so my point is to get you to + + align:start position:0% +internet so my point is to get you to + + + align:start position:0% +internet so my point is to get you to +realize the way the code becomes part of + + align:start position:0% +realize the way the code becomes part of + + + align:start position:0% +realize the way the code becomes part of +the law of this contract and you have to + + align:start position:0% +the law of this contract and you have to + + + align:start position:0% +the law of this contract and you have to +ask yourself the question whether that + + align:start position:0% +ask yourself the question whether that + + + align:start position:0% +ask yourself the question whether that +law is respecting the law of the + + align:start position:0% +law is respecting the law of the + + + align:start position:0% +law is respecting the law of the +sovereign the law of the jurisdiction so + + align:start position:0% +sovereign the law of the jurisdiction so + + + align:start position:0% +sovereign the law of the jurisdiction so +when Apple and Disney get together and + + align:start position:0% +when Apple and Disney get together and + + + align:start position:0% +when Apple and Disney get together and +they sell this technology and they sell + + align:start position:0% +they sell this technology and they sell + + + align:start position:0% +they sell this technology and they sell +movies across the i2 platform that make + + align:start position:0% +movies across the i2 platform that make + + + align:start position:0% +movies across the i2 platform that make +it practically impossible you know + + align:start position:0% +it practically impossible you know + + + align:start position:0% +it practically impossible you know +there's not even code I mean if you go + + align:start position:0% +there's not even code I mean if you go + + + align:start position:0% +there's not even code I mean if you go +out there and you look you + + align:start position:0% +out there and you look you + + + align:start position:0% +out there and you look you +find everybody who says yeah with this + + align:start position:0% +find everybody who says yeah with this + + + align:start position:0% +find everybody who says yeah with this +version nobody's yet found a way to + + align:start position:0% +version nobody's yet found a way to + + + align:start position:0% +version nobody's yet found a way to +break it okay so so right now we're in a + + align:start position:0% +break it okay so so right now we're in a + + + align:start position:0% +break it okay so so right now we're in a +world where right now it's not possible + + align:start position:0% +world where right now it's not possible + + + align:start position:0% +world where right now it's not possible +for me to capture three seconds to put + + align:start position:0% +for me to capture three seconds to put + + + align:start position:0% +for me to capture three seconds to put +into a presentation and the issue that + + align:start position:0% +into a presentation and the issue that + + + align:start position:0% +into a presentation and the issue that +raises is to what extent is that + + align:start position:0% +raises is to what extent is that + + + align:start position:0% +raises is to what extent is that +consistent with copyright law if the + + align:start position:0% +consistent with copyright law if the + + + align:start position:0% +consistent with copyright law if the +technology now disables you from doing + + align:start position:0% +technology now disables you from doing + + + align:start position:0% +technology now disables you from doing +exactly what copyright law wants so this + + align:start position:0% +exactly what copyright law wants so this + + + align:start position:0% +exactly what copyright law wants so this +is the trade-off to think about the + + align:start position:0% +is the trade-off to think about the + + + align:start position:0% +is the trade-off to think about the +relationship between the policy that the + + align:start position:0% +relationship between the policy that the + + + align:start position:0% +relationship between the policy that the +law wants and the policy of the + + align:start position:0% +law wants and the policy of the + + + align:start position:0% +law wants and the policy of the +technology and there's no reason to + + align:start position:0% +technology and there's no reason to + + + align:start position:0% +technology and there's no reason to +believe the policy of the technology + + align:start position:0% +believe the policy of the technology + + + align:start position:0% +believe the policy of the technology +will always be consistent with the law + + align:start position:0% +will always be consistent with the law + + + align:start position:0% +will always be consistent with the law +and to the extent that's not consistent + + align:start position:0% +and to the extent that's not consistent + + + align:start position:0% +and to the extent that's not consistent +with the law it challenges the law it + + align:start position:0% +with the law it challenges the law it + + + align:start position:0% +with the law it challenges the law it +says to the law okay come out and get me + + align:start position:0% +says to the law okay come out and get me + + + align:start position:0% +says to the law okay come out and get me +now that obviously is implicated in the + + align:start position:0% +now that obviously is implicated in the + + + align:start position:0% +now that obviously is implicated in the +context of smart contracts because the + + align:start position:0% +context of smart contracts because the + + + align:start position:0% +context of smart contracts because the +biggest fear about smart contracts is + + align:start position:0% +biggest fear about smart contracts is + + + align:start position:0% +biggest fear about smart contracts is +that they enable a kind of transaction + + align:start position:0% +that they enable a kind of transaction + + + align:start position:0% +that they enable a kind of transaction +that can hide from the policy of the law + + align:start position:0% +that can hide from the policy of the law + + + align:start position:0% +that can hide from the policy of the law +so that question for the law is what + + align:start position:0% +so that question for the law is what + + + align:start position:0% +so that question for the law is what +will you do to step in and this is I + + align:start position:0% +will you do to step in and this is I + + + align:start position:0% +will you do to step in and this is I +think that where your question is going + + align:start position:0% +think that where your question is going + + + align:start position:0% +think that where your question is going +how does the state appear in the middle + + align:start position:0% +how does the state appear in the middle + + + align:start position:0% +how does the state appear in the middle +of that contract to that okay that's the + + align:start position:0% +of that contract to that okay that's the + + + align:start position:0% +of that contract to that okay that's the +second second point here's a third point + + align:start position:0% +second second point here's a third point + + + align:start position:0% +second second point here's a third point +there's often this intuition that + + align:start position:0% +there's often this intuition that + + + align:start position:0% +there's often this intuition that +especially technologists people have + + align:start position:0% +especially technologists people have + + + align:start position:0% +especially technologists people have +about what the particular aim of + + align:start position:0% +about what the particular aim of + + + align:start position:0% +about what the particular aim of +contract law is so in the very beginning + + align:start position:0% +contract law is so in the very beginning + + + align:start position:0% +contract law is so in the very beginning +of me writing about the law of + + align:start position:0% +of me writing about the law of + + + align:start position:0% +of me writing about the law of +cyberspace somebody from MIT I won't + + align:start position:0% +cyberspace somebody from MIT I won't + + + align:start position:0% +cyberspace somebody from MIT I won't +name any names it wasn't Andy showed up + + align:start position:0% +name any names it wasn't Andy showed up + + + align:start position:0% +name any names it wasn't Andy showed up +at the Harvard Law School and said I've + + align:start position:0% +at the Harvard Law School and said I've + + + align:start position:0% +at the Harvard Law School and said I've +solved the problem of contract law I + + align:start position:0% +solved the problem of contract law I + + + align:start position:0% +solved the problem of contract law I +said what do you mean he said I have a + + align:start position:0% +said what do you mean he said I have a + + + align:start position:0% +said what do you mean he said I have a +system that will eliminate risks in + + align:start position:0% +system that will eliminate risks in + + + align:start position:0% +system that will eliminate risks in +contracts and he was really disappointed + + align:start position:0% +contracts and he was really disappointed + + + align:start position:0% +contracts and he was really disappointed +when I said you know the objective of + + align:start position:0% +when I said you know the objective of + + + align:start position:0% +when I said you know the objective of +contract law is not to eliminate risks + + align:start position:0% +contract law is not to eliminate risks + + + align:start position:0% +contract law is not to eliminate risks +the objective of contract law is just to + + align:start position:0% +the objective of contract law is just to + + + align:start position:0% +the objective of contract law is just to +allocate risk to figure out who has the + + align:start position:0% +allocate risk to figure out who has the + + + align:start position:0% +allocate risk to figure out who has the +risk so each of us can figure out what + + align:start position:0% +risk so each of us can figure out what + + + align:start position:0% +risk so each of us can figure out what +to do in light of the risk so if I say I + + align:start position:0% +to do in light of the risk so if I say I + + + align:start position:0% +to do in light of the risk so if I say I +will buy ten thousand bushels of corn + + align:start position:0% +will buy ten thousand bushels of corn + + + align:start position:0% +will buy ten thousand bushels of corn +from you at 350 a bushel turns out that + + align:start position:0% +from you at 350 a bushel turns out that + + + align:start position:0% +from you at 350 a bushel turns out that +is the price of corn right now um he + + align:start position:0% +is the price of corn right now um he + + + align:start position:0% +is the price of corn right now um he +always looks up things on the internet I + + align:start position:0% +always looks up things on the internet I + + + align:start position:0% +always looks up things on the internet I +figure I should look it up before I + + align:start position:0% +figure I should look it up before I + + + align:start position:0% +figure I should look it up before I +presented 350 is the price of a bushel + + align:start position:0% +presented 350 is the price of a bushel + + + align:start position:0% +presented 350 is the price of a bushel +of corn right now deliver September 1 + + align:start position:0% +of corn right now deliver September 1 + + + align:start position:0% +of corn right now deliver September 1 +what that's basically doing is it + + align:start position:0% +what that's basically doing is it + + + align:start position:0% +what that's basically doing is it +allocating the risk of the price of corn + + align:start position:0% +allocating the risk of the price of corn + + + align:start position:0% +allocating the risk of the price of corn +so if you're a farmer and you don't want + + align:start position:0% +so if you're a farmer and you don't want + + + align:start position:0% +so if you're a farmer and you don't want +to face the risk the price of corn is + + align:start position:0% +to face the risk the price of corn is + + + align:start position:0% +to face the risk the price of corn is +gonna fall to $3 you enter into this + + align:start position:0% +gonna fall to $3 you enter into this + + + align:start position:0% +gonna fall to $3 you enter into this +contract if you're a buyer you accept + + align:start position:0% +contract if you're a buyer you accept + + + align:start position:0% +contract if you're a buyer you accept +this contract but if the price of corn + + align:start position:0% +this contract but if the price of corn + + + align:start position:0% +this contract but if the price of corn +falls to $3 well you're you're out of + + align:start position:0% +falls to $3 well you're you're out of + + + align:start position:0% +falls to $3 well you're you're out of +luck so the point is it relocates the + + align:start position:0% +luck so the point is it relocates the + + + align:start position:0% +luck so the point is it relocates the +price of price change reallocates the + + align:start position:0% +price of price change reallocates the + + + align:start position:0% +price of price change reallocates the +risk of price gauge also reallocates the + + align:start position:0% +risk of price gauge also reallocates the + + + align:start position:0% +risk of price gauge also reallocates the +risk of delivery so if I've got all this + + align:start position:0% +risk of delivery so if I've got all this + + + align:start position:0% +risk of delivery so if I've got all this +corn I can place it in a certain place + + align:start position:0% +corn I can place it in a certain place + + + align:start position:0% +corn I can place it in a certain place +to shift the risk of delivery so that + + align:start position:0% +to shift the risk of delivery so that + + + align:start position:0% +to shift the risk of delivery so that +once again I'm in deep I used the + + align:start position:0% +once again I'm in deep I used the + + + align:start position:0% +once again I'm in deep I used the +contract to shift my risk of storage or + + align:start position:0% +contract to shift my risk of storage or + + + align:start position:0% +contract to shift my risk of storage or +my risk of delivery and you on the other + + align:start position:0% +my risk of delivery and you on the other + + + align:start position:0% +my risk of delivery and you on the other +side so the objective of contract law + + align:start position:0% +side so the objective of contract law + + + align:start position:0% +side so the objective of contract law +number one is risk allocation number one + + align:start position:0% +number one is risk allocation number one + + + align:start position:0% +number one is risk allocation number one +but allocation matters only if come say + + align:start position:0% +but allocation matters only if come say + + + align:start position:0% +but allocation matters only if come say +olia for me only if there's a system to + + align:start position:0% +olia for me only if there's a system to + + + align:start position:0% +olia for me only if there's a system to +process the breach of a contract only if + + align:start position:0% +process the breach of a contract only if + + + align:start position:0% +process the breach of a contract only if +you've got a technology let's say for + + align:start position:0% +you've got a technology let's say for + + + align:start position:0% +you've got a technology let's say for +processing the brief so if I have a + + align:start position:0% +processing the brief so if I have a + + + align:start position:0% +processing the brief so if I have a +contract with you of ten thousand + + align:start position:0% +contract with you of ten thousand + + + align:start position:0% +contract with you of ten thousand +bushels of corn three dollars and fifty + + align:start position:0% +bushels of corn three dollars and fifty + + + align:start position:0% +bushels of corn three dollars and fifty +on September first and you don't deliver + + align:start position:0% +on September first and you don't deliver + + + align:start position:0% +on September first and you don't deliver +that's a breach my risk has only been + + align:start position:0% +that's a breach my risk has only been + + + align:start position:0% +that's a breach my risk has only been +reallocated if there's some way for me + + align:start position:0% +reallocated if there's some way for me + + + align:start position:0% +reallocated if there's some way for me +to enforce the contract at that point so + + align:start position:0% +to enforce the contract at that point so + + + align:start position:0% +to enforce the contract at that point so +it requires this system and the system + + align:start position:0% +it requires this system and the system + + + align:start position:0% +it requires this system and the system +we ordinarily take for granted as a + + align:start position:0% +we ordinarily take for granted as a + + + align:start position:0% +we ordinarily take for granted as a +legal system and I say we take it for + + align:start position:0% +legal system and I say we take it for + + + align:start position:0% +legal system and I say we take it for +granted meaning some people can take it + + align:start position:0% +granted meaning some people can take it + + + align:start position:0% +granted meaning some people can take it +for granted like people in + + align:start position:0% +for granted like people in + + + align:start position:0% +for granted like people in +well-developed legal contexts but that's + + align:start position:0% +well-developed legal contexts but that's + + + align:start position:0% +well-developed legal contexts but that's +also emphasized other people can't take + + align:start position:0% +also emphasized other people can't take + + + align:start position:0% +also emphasized other people can't take +it for granted so for example people in + + align:start position:0% +it for granted so for example people in + + + align:start position:0% +it for granted so for example people in +developing worlds they can't take the + + align:start position:0% +developing worlds they can't take the + + + align:start position:0% +developing worlds they can't take the +legal system for granted they can't + + align:start position:0% +legal system for granted they can't + + + align:start position:0% +legal system for granted they can't +assume that if the contracts breach they + + align:start position:0% +assume that if the contracts breach they + + + align:start position:0% +assume that if the contracts breach they +can go into a court and say enforce the + + align:start position:0% +can go into a court and say enforce the + + + align:start position:0% +can go into a court and say enforce the +contract where give me damages or if + + align:start position:0% +contract where give me damages or if + + + align:start position:0% +contract where give me damages or if +you've got our contract between someone + + align:start position:0% +you've got our contract between someone + + + align:start position:0% +you've got our contract between someone +in Rwanda and somebody in Alaska then + + align:start position:0% +in Rwanda and somebody in Alaska then + + + align:start position:0% +in Rwanda and somebody in Alaska then +there - there's a question of whether + + align:start position:0% +there - there's a question of whether + + + align:start position:0% +there - there's a question of whether +we've got sufficient infrastructure to + + align:start position:0% +we've got sufficient infrastructure to + + + align:start position:0% +we've got sufficient infrastructure to +development so so so the point I want to + + align:start position:0% +development so so so the point I want to + + + align:start position:0% +development so so so the point I want to +emphasize at the end of this little + + align:start position:0% +emphasize at the end of this little + + + align:start position:0% +emphasize at the end of this little +intervention is to suggest that this + + align:start position:0% +intervention is to suggest that this + + + align:start position:0% +intervention is to suggest that this +fact that it takes for granted the + + align:start position:0% +fact that it takes for granted the + + + align:start position:0% +fact that it takes for granted the +system of enforcement shows the real + + align:start position:0% +system of enforcement shows the real + + + align:start position:0% +system of enforcement shows the real +potential benefit + + align:start position:0% +potential benefit + + + align:start position:0% +potential benefit +of this class of contracting devices + + align:start position:0% +of this class of contracting devices + + + align:start position:0% +of this class of contracting devices +because if we think about this as + + align:start position:0% +because if we think about this as + + + align:start position:0% +because if we think about this as +representation of a well-developed legal + + align:start position:0% +representation of a well-developed legal + + + align:start position:0% +representation of a well-developed legal +system and we think of first world + + align:start position:0% +system and we think of first world + + + align:start position:0% +system and we think of first world +countries that's having those and we + + align:start position:0% +countries that's having those and we + + + align:start position:0% +countries that's having those and we +compare like third world or developing + + align:start position:0% +compare like third world or developing + + + align:start position:0% +compare like third world or developing +world countries don't have these + + align:start position:0% +world countries don't have these + + + align:start position:0% +world countries don't have these +well-developed legal systems you might + + align:start position:0% +well-developed legal systems you might + + + align:start position:0% +well-developed legal systems you might +say that first world countries are + + align:start position:0% +say that first world countries are + + + align:start position:0% +say that first world countries are +better off relative to third world + + align:start position:0% +better off relative to third world + + + align:start position:0% +better off relative to third world +countries because they have the legal + + align:start position:0% +countries because they have the legal + + + align:start position:0% +countries because they have the legal +infrastructure to enable this risk + + align:start position:0% +infrastructure to enable this risk + + + align:start position:0% +infrastructure to enable this risk +allocation that will enable all sorts of + + align:start position:0% +allocation that will enable all sorts of + + + align:start position:0% +allocation that will enable all sorts of +market transactions to happen which + + align:start position:0% +market transactions to happen which + + + align:start position:0% +market transactions to happen which +otherwise wouldn't happen but if we + + align:start position:0% +otherwise wouldn't happen but if we + + + align:start position:0% +otherwise wouldn't happen but if we +imagine infrastructure like blockchain + + align:start position:0% +imagine infrastructure like blockchain + + + align:start position:0% +imagine infrastructure like blockchain +like infrastructures or aetherium + + align:start position:0% +like infrastructures or aetherium + + + align:start position:0% +like infrastructures or aetherium +infrastructures to enter the mix + + align:start position:0% +infrastructures to enter the mix + + + align:start position:0% +infrastructures to enter the mix +providing a technical infrastructure + + align:start position:0% +providing a technical infrastructure + + + align:start position:0% +providing a technical infrastructure +that doesn't require judges and lawyers + + align:start position:0% +that doesn't require judges and lawyers + + + align:start position:0% +that doesn't require judges and lawyers +but just requires code then that can + + align:start position:0% +but just requires code then that can + + + align:start position:0% +but just requires code then that can +come that can supplement substitute for + + align:start position:0% +come that can supplement substitute for + + + align:start position:0% +come that can supplement substitute for +the legal infrastructure provide the + + align:start position:0% +the legal infrastructure provide the + + + align:start position:0% +the legal infrastructure provide the +infrastructure the contract needs at a + + align:start position:0% +infrastructure the contract needs at a + + + align:start position:0% +infrastructure the contract needs at a +much lower cost and thereby enable + + align:start position:0% +much lower cost and thereby enable + + + align:start position:0% +much lower cost and thereby enable +people to contract who otherwise + + align:start position:0% +people to contract who otherwise + + + align:start position:0% +people to contract who otherwise +wouldn't rationally contract because + + align:start position:0% +wouldn't rationally contract because + + + align:start position:0% +wouldn't rationally contract because +they could never count on the + + align:start position:0% +they could never count on the + + + align:start position:0% +they could never count on the +infrastructure of the legal system to + + align:start position:0% +infrastructure of the legal system to + + + align:start position:0% +infrastructure of the legal system to +deliver what they need okay so the point + + align:start position:0% +deliver what they need okay so the point + + + align:start position:0% +deliver what they need okay so the point +is this picture is trying to say that + + align:start position:0% +is this picture is trying to say that + + + align:start position:0% +is this picture is trying to say that +the key value one key value of these + + align:start position:0% +the key value one key value of these + + + align:start position:0% +the key value one key value of these +technologies is that they will be a + + align:start position:0% +technologies is that they will be a + + + align:start position:0% +technologies is that they will be a +substitute for a failed legal system or + + align:start position:0% +substitute for a failed legal system or + + + align:start position:0% +substitute for a failed legal system or +a legal system that's not yet developed + + align:start position:0% +a legal system that's not yet developed + + + align:start position:0% +a legal system that's not yet developed +they will provide the infrastructure of + + align:start position:0% +they will provide the infrastructure of + + + align:start position:0% +they will provide the infrastructure of +a legal system or the legal system do + + align:start position:0% +a legal system or the legal system do + + + align:start position:0% +a legal system or the legal system do +anything because you can't make that + + align:start position:0% +anything because you can't make that + + + align:start position:0% +anything because you can't make that +contract with I will pay you three point + + align:start position:0% +contract with I will pay you three point + + + align:start position:0% +contract with I will pay you three point +five dollars per bushel temple first + + align:start position:0% +five dollars per bushel temple first + + + align:start position:0% +five dollars per bushel temple first +immaterial because you're making a + + align:start position:0% +immaterial because you're making a + + + align:start position:0% +immaterial because you're making a +statement about the real world your + + align:start position:0% +statement about the real world your + + + align:start position:0% +statement about the real world your +theory of blockchain cannot verify that + + align:start position:0% +theory of blockchain cannot verify that + + + align:start position:0% +theory of blockchain cannot verify that +I gave you the bushes they're very risky + + align:start position:0% +I gave you the bushes they're very risky + + + align:start position:0% +I gave you the bushes they're very risky +I should say racket for just I think + + align:start position:0% +I should say racket for just I think + + + align:start position:0% +I should say racket for just I think +it's I'm not sure if it's to you but + + align:start position:0% +it's I'm not sure if it's to you but + + + align:start position:0% +it's I'm not sure if it's to you but +it's in slides but you know n is less + + align:start position:0% +it's in slides but you know n is less + + + align:start position:0% +it's in slides but you know n is less +than a hundred I promise + + align:start position:0% +than a hundred I promise + + + align:start position:0% +than a hundred I promise +so just hold one second okay so if you + + align:start position:0% +so just hold one second okay so if you + + + align:start position:0% +so just hold one second okay so if you +say that one function here is to + + align:start position:0% +say that one function here is to + + + align:start position:0% +say that one function here is to +substitute for a failed legal system + + align:start position:0% +substitute for a failed legal system + + + align:start position:0% +substitute for a failed legal system +um that suggests the other key + + align:start position:0% +um that suggests the other key + + + align:start position:0% +um that suggests the other key +opportunity here is to enable contracts + + align:start position:0% +opportunity here is to enable contracts + + + align:start position:0% +opportunity here is to enable contracts +where the transaction costs right now + + align:start position:0% +where the transaction costs right now + + + align:start position:0% +where the transaction costs right now +are otherwise too high so this is a key + + align:start position:0% +are otherwise too high so this is a key + + + align:start position:0% +are otherwise too high so this is a key +opportunity to think of places where you + + align:start position:0% +opportunity to think of places where you + + + align:start position:0% +opportunity to think of places where you +could lower the transaction costs of the + + align:start position:0% +could lower the transaction costs of the + + + align:start position:0% +could lower the transaction costs of the +contract you will enable a contract + + align:start position:0% +contract you will enable a contract + + + align:start position:0% +contract you will enable a contract +which otherwise exists right now so I'm + + align:start position:0% +which otherwise exists right now so I'm + + + align:start position:0% +which otherwise exists right now so I'm +on a bull a scientific board for an + + align:start position:0% +on a bull a scientific board for an + + + align:start position:0% +on a bull a scientific board for an +insurance company and insurance company + + align:start position:0% +insurance company and insurance company + + + align:start position:0% +insurance company and insurance company +I saw I was meeting the president this + + align:start position:0% +I saw I was meeting the president this + + + align:start position:0% +I saw I was meeting the president this +week last week and he was all excited + + align:start position:0% +week last week and he was all excited + + + align:start position:0% +week last week and he was all excited +about a new product which they were + + align:start position:0% +about a new product which they were + + + align:start position:0% +about a new product which they were +investing in which was going to provide + + align:start position:0% +investing in which was going to provide + + + align:start position:0% +investing in which was going to provide +flight delay insurance and this product + + align:start position:0% +flight delay insurance and this product + + + align:start position:0% +flight delay insurance and this product +was going to be completely blocked + + align:start position:0% +was going to be completely blocked + + + align:start position:0% +was going to be completely blocked +chain-driven and it would this is that + + align:start position:0% +chain-driven and it would this is that + + + align:start position:0% +chain-driven and it would this is that +I'm trying to get to your point it would + + align:start position:0% +I'm trying to get to your point it would + + + align:start position:0% +I'm trying to get to your point it would +trigger payments and a completely + + align:start position:0% +trigger payments and a completely + + + align:start position:0% +trigger payments and a completely +automatic way based on the information + + align:start position:0% +automatic way based on the information + + + align:start position:0% +automatic way based on the information +that's being reported from you know the + + align:start position:0% +that's being reported from you know the + + + align:start position:0% +that's being reported from you know the +end different sites that are reporting + + align:start position:0% +end different sites that are reporting + + + align:start position:0% +end different sites that are reporting +information about flight so I buy the + + align:start position:0% +information about flight so I buy the + + + align:start position:0% +information about flight so I buy the +contract it says if my flights delayed + + align:start position:0% +contract it says if my flights delayed + + + align:start position:0% +contract it says if my flights delayed +more than an hour + + align:start position:0% +more than an hour + + + align:start position:0% +more than an hour +I get paid $200 and automatically as as + + align:start position:0% +I get paid $200 and automatically as as + + + align:start position:0% +I get paid $200 and automatically as as +he put it it's a no touch product by + + align:start position:0% +he put it it's a no touch product by + + + align:start position:0% +he put it it's a no touch product by +which he meant no human needs to touch + + align:start position:0% +which he meant no human needs to touch + + + align:start position:0% +which he meant no human needs to touch +this product for this contract to be + + align:start position:0% +this product for this contract to be + + + align:start position:0% +this product for this contract to be +enabled it's a kind of product that + + align:start position:0% +enabled it's a kind of product that + + + align:start position:0% +enabled it's a kind of product that +never would have been available before + + align:start position:0% +never would have been available before + + + align:start position:0% +never would have been available before +because the transaction cost of engaging + + align:start position:0% +because the transaction cost of engaging + + + align:start position:0% +because the transaction cost of engaging +it were way too high but now that we've + + align:start position:0% +it were way too high but now that we've + + + align:start position:0% +it were way too high but now that we've +lowered the transaction cost and have an + + align:start position:0% +lowered the transaction cost and have an + + + align:start position:0% +lowered the transaction cost and have an +infrastructure of trust which is what + + align:start position:0% +infrastructure of trust which is what + + + align:start position:0% +infrastructure of trust which is what +the blockchain is providing here there's + + align:start position:0% +the blockchain is providing here there's + + + align:start position:0% +the blockchain is providing here there's +a huge market that now is out available + + align:start position:0% +a huge market that now is out available + + + align:start position:0% +a huge market that now is out available +for a contract that otherwise you know + + align:start position:0% +for a contract that otherwise you know + + + align:start position:0% +for a contract that otherwise you know +it just wasn't there before + + align:start position:0% +it just wasn't there before + + + align:start position:0% +it just wasn't there before +now that market depends on making a + + align:start position:0% +now that market depends on making a + + + align:start position:0% +now that market depends on making a +couple assumptions you're not saying + + align:start position:0% +couple assumptions you're not saying + + + align:start position:0% +couple assumptions you're not saying +that there's a hundred percent certainty + + align:start position:0% +that there's a hundred percent certainty + + + align:start position:0% +that there's a hundred percent certainty +that everything in that market is + + align:start position:0% +that everything in that market is + + + align:start position:0% +that everything in that market is +working the way it's supposed to work + + align:start position:0% +working the way it's supposed to work + + + align:start position:0% +working the way it's supposed to work +but the point is you don't need a + + align:start position:0% +but the point is you don't need a + + + align:start position:0% +but the point is you don't need a +hundred percent certainty for the vast + + align:start position:0% +hundred percent certainty for the vast + + + align:start position:0% +hundred percent certainty for the vast +majority of these kinds of contracts if + + align:start position:0% +majority of these kinds of contracts if + + + align:start position:0% +majority of these kinds of contracts if +it gets it wrong every once in a while + + align:start position:0% +it gets it wrong every once in a while + + + align:start position:0% +it gets it wrong every once in a while +you know that's good enough for + + align:start position:0% +you know that's good enough for + + + align:start position:0% +you know that's good enough for +government work or good enough for + + align:start position:0% +government work or good enough for + + + align:start position:0% +government work or good enough for +airplane work and so so that's gonna be + + align:start position:0% +airplane work and so so that's gonna be + + + align:start position:0% +airplane work and so so that's gonna be +sufficient to enable the market + + align:start position:0% +sufficient to enable the market + + + align:start position:0% +sufficient to enable the market +recognizing that even in the legal + + align:start position:0% +recognizing that even in the legal + + + align:start position:0% +recognizing that even in the legal +system market guess what it doesn't + + align:start position:0% +system market guess what it doesn't + + + align:start position:0% +system market guess what it doesn't +always get it right either well it + + align:start position:0% +always get it right either well it + + + align:start position:0% +always get it right either well it +doesn't always enforce the contract well + + align:start position:0% +doesn't always enforce the contract well + + + align:start position:0% +doesn't always enforce the contract well +either in fact the costs are much much + + align:start position:0% +either in fact the costs are much much + + + align:start position:0% +either in fact the costs are much much +higher to fail in + + align:start position:0% +higher to fail in + + + align:start position:0% +higher to fail in +okay so two kinds of transaction costs + + align:start position:0% +okay so two kinds of transaction costs + + + align:start position:0% +okay so two kinds of transaction costs +one system transaction cost suggests + + align:start position:0% +one system transaction cost suggests + + + align:start position:0% +one system transaction cost suggests +that where you have less developed legal + + align:start position:0% +that where you have less developed legal + + + align:start position:0% +that where you have less developed legal +systems the blockchain is going to + + align:start position:0% +systems the blockchain is going to + + + align:start position:0% +systems the blockchain is going to +provide a real opportunity because + + align:start position:0% +provide a real opportunity because + + + align:start position:0% +provide a real opportunity because +you're going to lower the transaction + + align:start position:0% +you're going to lower the transaction + + + align:start position:0% +you're going to lower the transaction +cost for those systems and the other is + + align:start position:0% +cost for those systems and the other is + + + align:start position:0% +cost for those systems and the other is +just contract transaction costs there'll + + align:start position:0% +just contract transaction costs there'll + + + align:start position:0% +just contract transaction costs there'll +be a huge explosion of markets where + + align:start position:0% +be a huge explosion of markets where + + + align:start position:0% +be a huge explosion of markets where +right now the contract transaction costs + + align:start position:0% +right now the contract transaction costs + + + align:start position:0% +right now the contract transaction costs +are so high and we can lower them and + + align:start position:0% +are so high and we can lower them and + + + align:start position:0% +are so high and we can lower them and +thereby enable a certain kind of + + align:start position:0% +thereby enable a certain kind of + + + align:start position:0% +thereby enable a certain kind of +transaction that otherwise wouldn't be + + align:start position:0% +transaction that otherwise wouldn't be + + + align:start position:0% +transaction that otherwise wouldn't be +there okay final point I want to make + + align:start position:0% +there okay final point I want to make + + + align:start position:0% +there okay final point I want to make +the other thing technologists always + + align:start position:0% +the other thing technologists always + + + align:start position:0% +the other thing technologists always +love to say is the great thing we will + + align:start position:0% +love to say is the great thing we will + + + align:start position:0% +love to say is the great thing we will +do when we do contracts technologies is + + align:start position:0% +do when we do contracts technologies is + + + align:start position:0% +do when we do contracts technologies is +they'll be solved the clarity problem + + align:start position:0% +they'll be solved the clarity problem + + + align:start position:0% +they'll be solved the clarity problem +every term will be perfectly clear could + + align:start position:0% +every term will be perfectly clear could + + + align:start position:0% +every term will be perfectly clear could +you write those contracts out and + + align:start position:0% +you write those contracts out and + + + align:start position:0% +you write those contracts out and +there's all sorts of ambiguity vagueness + + align:start position:0% +there's all sorts of ambiguity vagueness + + + align:start position:0% +there's all sorts of ambiguity vagueness +and it's a total mess but when we've + + align:start position:0% +and it's a total mess but when we've + + + align:start position:0% +and it's a total mess but when we've +coded all of our contracts our smart + + align:start position:0% +coded all of our contracts our smart + + + align:start position:0% +coded all of our contracts our smart +contracts then we'll have perfect + + align:start position:0% +contracts then we'll have perfect + + + align:start position:0% +contracts then we'll have perfect +certainty for every single outcome and + + align:start position:0% +certainty for every single outcome and + + + align:start position:0% +certainty for every single outcome and +that will be great and the point I want + + align:start position:0% +that will be great and the point I want + + + align:start position:0% +that will be great and the point I want +to suggest to you is the is that often + + align:start position:0% +to suggest to you is the is that often + + + align:start position:0% +to suggest to you is the is that often +obscurity is a real value obscurity is + + align:start position:0% +obscurity is a real value obscurity is + + + align:start position:0% +obscurity is a real value obscurity is +what you want because there's a way to + + align:start position:0% +what you want because there's a way to + + + align:start position:0% +what you want because there's a way to +see it so imagine this is a decision + + align:start position:0% +see it so imagine this is a decision + + + align:start position:0% +see it so imagine this is a decision +tree and it's really small because I + + align:start position:0% +tree and it's really small because I + + + align:start position:0% +tree and it's really small because I +just stole it from the internet + + align:start position:0% +just stole it from the internet + + + align:start position:0% +just stole it from the internet +it doesn't have anything to do really + + align:start position:0% +it doesn't have anything to do really + + + align:start position:0% +it doesn't have anything to do really +with what I'm talking about here but + + align:start position:0% +with what I'm talking about here but + + + align:start position:0% +with what I'm talking about here but +imagine a really complicated decision + + align:start position:0% +imagine a really complicated decision + + + align:start position:0% +imagine a really complicated decision +tree like this we just represent all the + + align:start position:0% +tree like this we just represent all the + + + align:start position:0% +tree like this we just represent all the +possible things that could happen with + + align:start position:0% +possible things that could happen with + + + align:start position:0% +possible things that could happen with +our deal so I want to buy the house but + + align:start position:0% +our deal so I want to buy the house but + + + align:start position:0% +our deal so I want to buy the house but +what happens that the house get hit by a + + align:start position:0% +what happens that the house get hit by a + + + align:start position:0% +what happens that the house get hit by a +meteor or what happens if you go + + align:start position:0% +meteor or what happens if you go + + + align:start position:0% +meteor or what happens if you go +bankrupt all of these possible outcomes + + align:start position:0% +bankrupt all of these possible outcomes + + + align:start position:0% +bankrupt all of these possible outcomes +and in principle we could say we should + + align:start position:0% +and in principle we could say we should + + + align:start position:0% +and in principle we could say we should +be negotiating every one of these blue + + align:start position:0% +be negotiating every one of these blue + + + align:start position:0% +be negotiating every one of these blue +dots we should be saying what happens if + + align:start position:0% +dots we should be saying what happens if + + + align:start position:0% +dots we should be saying what happens if +this happens okay then this is what you + + align:start position:0% +this happens okay then this is what you + + + align:start position:0% +this happens okay then this is what you +get in this good idea what happens if + + align:start position:0% +get in this good idea what happens if + + + align:start position:0% +get in this good idea what happens if +that house would you get rid of okay so + + align:start position:0% +that house would you get rid of okay so + + + align:start position:0% +that house would you get rid of okay so +it imagine this blue dot here has a + + align:start position:0% +it imagine this blue dot here has a + + + align:start position:0% +it imagine this blue dot here has a +point zero zero two percent chance of + + align:start position:0% +point zero zero two percent chance of + + + align:start position:0% +point zero zero two percent chance of +happening so you know the chance of that + + align:start position:0% +happening so you know the chance of that + + + align:start position:0% +happening so you know the chance of that +happening is practically zero and so + + align:start position:0% +happening is practically zero and so + + + align:start position:0% +happening is practically zero and so +what's the reasonable amount of time you + + align:start position:0% +what's the reasonable amount of time you + + + align:start position:0% +what's the reasonable amount of time you +should spend negotiating that term zero + + align:start position:0% +should spend negotiating that term zero + + + align:start position:0% +should spend negotiating that term zero +right especially because you know if you + + align:start position:0% +right especially because you know if you + + + align:start position:0% +right especially because you know if you +know if you this term is something you + + align:start position:0% +know if you this term is something you + + + align:start position:0% +know if you this term is something you +know he's really he's really + + align:start position:0% +know he's really he's really + + + align:start position:0% +know he's really he's really +worked up about and you could never come + + align:start position:0% +worked up about and you could never come + + + align:start position:0% +worked up about and you could never come +to an agreement about that term it would + + align:start position:0% +to an agreement about that term it would + + + align:start position:0% +to an agreement about that term it would +be ridiculous that the whole contract + + align:start position:0% +be ridiculous that the whole contract + + + align:start position:0% +be ridiculous that the whole contract +fall about because of this point zero + + align:start position:0% +fall about because of this point zero + + + align:start position:0% +fall about because of this point zero +zero two percent possibility + + align:start position:0% +zero two percent possibility + + + align:start position:0% +zero two percent possibility +so what contracts do all the time is + + align:start position:0% +so what contracts do all the time is + + + align:start position:0% +so what contracts do all the time is +they create these fuzzy or vague or + + align:start position:0% +they create these fuzzy or vague or + + + align:start position:0% +they create these fuzzy or vague or +ambiguous places as a gamble it's like + + align:start position:0% +ambiguous places as a gamble it's like + + + align:start position:0% +ambiguous places as a gamble it's like +okay we'll go forward we're gonna just + + align:start position:0% +okay we'll go forward we're gonna just + + + align:start position:0% +okay we'll go forward we're gonna just +gamble that this point zero zero two + + align:start position:0% +gamble that this point zero zero two + + + align:start position:0% +gamble that this point zero zero two +percent outcome won't happen most of the + + align:start position:0% +percent outcome won't happen most of the + + + align:start position:0% +percent outcome won't happen most of the +time in fact you can work out how often + + align:start position:0% +time in fact you can work out how often + + + align:start position:0% +time in fact you can work out how often +it doesn't happen right so most of the + + align:start position:0% +it doesn't happen right so most of the + + + align:start position:0% +it doesn't happen right so most of the +time that'll be just fine and if it + + align:start position:0% +time that'll be just fine and if it + + + align:start position:0% +time that'll be just fine and if it +turns out to happen then what we'll do + + align:start position:0% +turns out to happen then what we'll do + + + align:start position:0% +turns out to happen then what we'll do +is ask somebody namely a judge to figure + + align:start position:0% +is ask somebody namely a judge to figure + + + align:start position:0% +is ask somebody namely a judge to figure +that term out we'll say what should that + + align:start position:0% +that term out we'll say what should that + + + align:start position:0% +that term out we'll say what should that +term be interpreted as it was ambiguous + + align:start position:0% +term be interpreted as it was ambiguous + + + align:start position:0% +term be interpreted as it was ambiguous +so what should the answer be and the + + align:start position:0% +so what should the answer be and the + + + align:start position:0% +so what should the answer be and the +judge will look at in judges Li well + + align:start position:0% +judge will look at in judges Li well + + + align:start position:0% +judge will look at in judges Li well +it's fair that you win or he wins so the + + align:start position:0% +it's fair that you win or he wins so the + + + align:start position:0% +it's fair that you win or he wins so the +point is there are many times when you + + align:start position:0% +point is there are many times when you + + + align:start position:0% +point is there are many times when you +ask the question should you negotiate a + + align:start position:0% +ask the question should you negotiate a + + + align:start position:0% +ask the question should you negotiate a +term ex ante and the answer to that + + align:start position:0% +term ex ante and the answer to that + + + align:start position:0% +term ex ante and the answer to that +question is no and in those contexts and + + align:start position:0% +question is no and in those contexts and + + + align:start position:0% +question is no and in those contexts and +ambiguity is a way to negotiate it ex + + align:start position:0% +ambiguity is a way to negotiate it ex + + + align:start position:0% +ambiguity is a way to negotiate it ex +post meaning after the fact exposed by + + align:start position:0% +post meaning after the fact exposed by + + + align:start position:0% +post meaning after the fact exposed by +using the court so as we think about + + align:start position:0% +using the court so as we think about + + + align:start position:0% +using the court so as we think about +these digital smart contracts this is + + align:start position:0% +these digital smart contracts this is + + + align:start position:0% +these digital smart contracts this is +why smart contracts are referred to as + + align:start position:0% +why smart contracts are referred to as + + + align:start position:0% +why smart contracts are referred to as +dumb contracts they're smart contracts + + align:start position:0% +dumb contracts they're smart contracts + + + align:start position:0% +dumb contracts they're smart contracts +for the equivalent of dropping a dime in + + align:start position:0% +for the equivalent of dropping a dime in + + + align:start position:0% +for the equivalent of dropping a dime in +and getting a dr. pepper the sorts of + + align:start position:0% +and getting a dr. pepper the sorts of + + + align:start position:0% +and getting a dr. pepper the sorts of +things where the possibilities are + + align:start position:0% +things where the possibilities are + + + align:start position:0% +things where the possibilities are +really small and narrow or like my CEO + + align:start position:0% +really small and narrow or like my CEO + + + align:start position:0% +really small and narrow or like my CEO +was really excited is your plane late + + align:start position:0% +was really excited is your plane late + + + align:start position:0% +was really excited is your plane late +yes I get $50 no I don't things where + + align:start position:0% +yes I get $50 no I don't things where + + + align:start position:0% +yes I get $50 no I don't things where +it's relatively clear but there's a + + align:start position:0% +it's relatively clear but there's a + + + align:start position:0% +it's relatively clear but there's a +really important conceptual question + + align:start position:0% +really important conceptual question + + + align:start position:0% +really important conceptual question +about what happens when we're trying to + + align:start position:0% +about what happens when we're trying to + + + align:start position:0% +about what happens when we're trying to +use them for the kinds of contracts + + align:start position:0% +use them for the kinds of contracts + + + align:start position:0% +use them for the kinds of contracts +where what we want is ambiguity because + + align:start position:0% +where what we want is ambiguity because + + + align:start position:0% +where what we want is ambiguity because +if the way if the very terms of + + align:start position:0% +if the way if the very terms of + + + align:start position:0% +if the way if the very terms of +deployment the platform demands + + align:start position:0% +deployment the platform demands + + + align:start position:0% +deployment the platform demands +specifying all of the outcomes in this + + align:start position:0% +specifying all of the outcomes in this + + + align:start position:0% +specifying all of the outcomes in this +tree then your basic thing well there's + + align:start position:0% +tree then your basic thing well there's + + + align:start position:0% +tree then your basic thing well there's +a whole bunch of contracts you're just + + align:start position:0% +a whole bunch of contracts you're just + + + align:start position:0% +a whole bunch of contracts you're just +not going to be able to have in this + + align:start position:0% +not going to be able to have in this + + + align:start position:0% +not going to be able to have in this +space because the costs + + align:start position:0% +space because the costs + + + align:start position:0% +space because the costs +of specifying that tree will be higher + + align:start position:0% +of specifying that tree will be higher + + + align:start position:0% +of specifying that tree will be higher +than the benefit of those contracts so + + align:start position:0% +than the benefit of those contracts so + + + align:start position:0% +than the benefit of those contracts so +it's a weird sense in which on the one + + align:start position:0% +it's a weird sense in which on the one + + + align:start position:0% +it's a weird sense in which on the one +hand I've said to you that these tech + + align:start position:0% +hand I've said to you that these tech + + + align:start position:0% +hand I've said to you that these tech +this technology can lower the + + align:start position:0% +this technology can lower the + + + align:start position:0% +this technology can lower the +transaction cost of contracts but for + + align:start position:0% +transaction cost of contracts but for + + + align:start position:0% +transaction cost of contracts but for +this kind of contract it can actually + + align:start position:0% +this kind of contract it can actually + + + align:start position:0% +this kind of contract it can actually +increase the transaction costs of + + align:start position:0% +increase the transaction costs of + + + align:start position:0% +increase the transaction costs of +contracts because for this kind of + + align:start position:0% +contracts because for this kind of + + + align:start position:0% +contracts because for this kind of +contract if it reveals the ambiguities + + align:start position:0% +contract if it reveals the ambiguities + + + align:start position:0% +contract if it reveals the ambiguities +we need to negotiate about and those + + align:start position:0% +we need to negotiate about and those + + + align:start position:0% +we need to negotiate about and those +negotiated ambiguities are just too + + align:start position:0% +negotiated ambiguities are just too + + + align:start position:0% +negotiated ambiguities are just too +costly for us to negotiate then it's + + align:start position:0% +costly for us to negotiate then it's + + + align:start position:0% +costly for us to negotiate then it's +going to block us from having that + + align:start position:0% +going to block us from having that + + + align:start position:0% +going to block us from having that +contract that forces us to see the point + + align:start position:0% +contract that forces us to see the point + + + align:start position:0% +contract that forces us to see the point +zero zero two percent you and I have to + + align:start position:0% +zero zero two percent you and I have to + + + align:start position:0% +zero zero two percent you and I have to +come to terms on it and we don't get + + align:start position:0% +come to terms on it and we don't get + + + align:start position:0% +come to terms on it and we don't get +have a good way to fake ambiguity I mean + + align:start position:0% +have a good way to fake ambiguity I mean + + + align:start position:0% +have a good way to fake ambiguity I mean +the legal system takes ambiguity because + + align:start position:0% +the legal system takes ambiguity because + + + align:start position:0% +the legal system takes ambiguity because +we just say oh yeah we didn't see that + + align:start position:0% +we just say oh yeah we didn't see that + + + align:start position:0% +we just say oh yeah we didn't see that +they saw it he knew it when they wrote + + align:start position:0% +they saw it he knew it when they wrote + + + align:start position:0% +they saw it he knew it when they wrote +the contract but they don't have to + + align:start position:0% +the contract but they don't have to + + + align:start position:0% +the contract but they don't have to +admit they knew it but the but the code + + align:start position:0% +admit they knew it but the but the code + + + align:start position:0% +admit they knew it but the but the code +has to admit it knows there's an + + align:start position:0% +has to admit it knows there's an + + + align:start position:0% +has to admit it knows there's an +ambiguity and that's a hard thing to + + align:start position:0% +ambiguity and that's a hard thing to + + + align:start position:0% +ambiguity and that's a hard thing to +self-consciously okay so I've given you + + align:start position:0% +self-consciously okay so I've given you + + + align:start position:0% +self-consciously okay so I've given you +four ideas happy to take questions abuse + + align:start position:0% + + + + align:start position:0% + +so what if you can code into the + + align:start position:0% +so what if you can code into the + + + align:start position:0% +so what if you can code into the +contract like the the easy scenarios and + + align:start position:0% +contract like the the easy scenarios and + + + align:start position:0% +contract like the the easy scenarios and +then say like elsif or go to court + + align:start position:0% +then say like elsif or go to court + + + align:start position:0% +then say like elsif or go to court +or some like multinational court that is + + align:start position:0% +or some like multinational court that is + + + align:start position:0% +or some like multinational court that is +like very important and even the + + align:start position:0% +like very important and even the + + + align:start position:0% +like very important and even the +etherium court will have to have a court + + align:start position:0% +etherium court will have to have a court + + + align:start position:0% +etherium court will have to have a court +above it if it wants to avoid government + + align:start position:0% +above it if it wants to avoid government + + + align:start position:0% +above it if it wants to avoid government +saying if you have anything to do with + + align:start position:0% +saying if you have anything to do with + + + align:start position:0% +saying if you have anything to do with +the theory am we're gonna punish it + + align:start position:0% +the theory am we're gonna punish it + + + align:start position:0% +the theory am we're gonna punish it +right so this is the sense of which I + + align:start position:0% +right so this is the sense of which I + + + align:start position:0% +right so this is the sense of which I +wanted to suggest to go back to your + + align:start position:0% +wanted to suggest to go back to your + + + align:start position:0% +wanted to suggest to go back to your +first question that you know if you + + align:start position:0% +first question that you know if you + + + align:start position:0% +first question that you know if you +think about it as as layers of an onion + + align:start position:0% +think about it as as layers of an onion + + + align:start position:0% +think about it as as layers of an onion +peel the layers back enough and you're + + align:start position:0% +peel the layers back enough and you're + + + align:start position:0% +peel the layers back enough and you're +going to in the end have to get to a + + align:start position:0% +going to in the end have to get to a + + + align:start position:0% +going to in the end have to get to a +state in some sense you know state isn't + + align:start position:0% +state in some sense you know state isn't + + + align:start position:0% +state in some sense you know state isn't +as an enforceable mechanism and that + + align:start position:0% +as an enforceable mechanism and that + + + align:start position:0% +as an enforceable mechanism and that +enforceable mechanism I mean doesn't + + align:start position:0% +enforceable mechanism I mean doesn't + + + align:start position:0% +enforceable mechanism I mean doesn't +have to be for every case again 99% of + + align:start position:0% +have to be for every case again 99% of + + + align:start position:0% +have to be for every case again 99% of +the time you drop the diamond you get + + align:start position:0% +the time you drop the diamond you get + + + align:start position:0% +the time you drop the diamond you get +the dr. pepper but there's a contingency + + align:start position:0% +the dr. pepper but there's a contingency + + + align:start position:0% +the dr. pepper but there's a contingency +where you drop the diamond and out comes + + align:start position:0% +where you drop the diamond and out comes + + + align:start position:0% +where you drop the diamond and out comes +the bottle of gasoline and I need to go + + align:start position:0% +the bottle of gasoline and I need to go + + + align:start position:0% +the bottle of gasoline and I need to go +to somebody and say you've breached this + + align:start position:0% +to somebody and say you've breached this + + + align:start position:0% +to somebody and say you've breached this +contract and that person but if it's a + + align:start position:0% +contract and that person but if it's a + + + align:start position:0% +contract and that person but if it's a +contract between somebody and + + align:start position:0% +contract between somebody and + + + align:start position:0% +contract between somebody and +alaskan-style you know + + align:start position:0% +alaskan-style you know + + + align:start position:0% +alaskan-style you know +wit like you still have the question of + + align:start position:0% +wit like you still have the question of + + + align:start position:0% +wit like you still have the question of +which state to go to what's the + + align:start position:0% +which state to go to what's the + + + align:start position:0% +which state to go to what's the +jurisdiction so I feel like there would + + align:start position:0% +jurisdiction so I feel like there would + + + align:start position:0% +jurisdiction so I feel like there would +have to be some like extra national + + align:start position:0% +have to be some like extra national + + + align:start position:0% +have to be some like extra national +we'll see in these types of contracts is + + align:start position:0% +we'll see in these types of contracts is + + + align:start position:0% +we'll see in these types of contracts is +they'll be a whole bunch of boilerplate + + align:start position:0% +they'll be a whole bunch of boilerplate + + + align:start position:0% +they'll be a whole bunch of boilerplate +that specifies choice of law it turns + + align:start position:0% +that specifies choice of law it turns + + + align:start position:0% +that specifies choice of law it turns +out to be a relatively easy thing to do + + align:start position:0% +out to be a relatively easy thing to do + + + align:start position:0% +out to be a relatively easy thing to do +right now choice of jurisdictions for + + align:start position:0% +right now choice of jurisdictions for + + + align:start position:0% +right now choice of jurisdictions for +most countries is pretty user their + + align:start position:0% +most countries is pretty user their + + + align:start position:0% +most countries is pretty user their +standard ways to do that all that will + + align:start position:0% +standard ways to do that all that will + + + align:start position:0% +standard ways to do that all that will +plug in automatically but again all of + + align:start position:0% +plug in automatically but again all of + + + align:start position:0% +plug in automatically but again all of +those are outside of the code + + align:start position:0% +those are outside of the code + + + align:start position:0% +those are outside of the code +all of those are legally binding + + align:start position:0% +all of those are legally binding + + + align:start position:0% +all of those are legally binding +contracts so I government right trust + + align:start position:0% +contracts so I government right trust + + + align:start position:0% +contracts so I government right trust +the court I don't trust a software + + align:start position:0% +the court I don't trust a software + + + align:start position:0% +the court I don't trust a software +engineer to find a proper go protect me + + align:start position:0% +engineer to find a proper go protect me + + + align:start position:0% +engineer to find a proper go protect me +or my counterparty so like what do you + + align:start position:0% +or my counterparty so like what do you + + + align:start position:0% +or my counterparty so like what do you +think about that what is your take on + + align:start position:0% +think about that what is your take on + + + align:start position:0% +think about that what is your take on +those more contract not only your take + + align:start position:0% +those more contract not only your take + + + align:start position:0% +those more contract not only your take +on whether to trust but what the courts + + align:start position:0% +on whether to trust but what the courts + + + align:start position:0% +on whether to trust but what the courts +in Europe in the u.s. right now do if + + align:start position:0% +in Europe in the u.s. right now do if + + + align:start position:0% +in Europe in the u.s. right now do if +somebody says I wrote the contract and + + align:start position:0% +somebody says I wrote the contract and + + + align:start position:0% +somebody says I wrote the contract and +here's the code well so when you say let + + align:start position:0% +here's the code well so when you say let + + + align:start position:0% +here's the code well so when you say let +me just me understand a question better + + align:start position:0% +me just me understand a question better + + + align:start position:0% +me just me understand a question better +the way I'm sorry your name is dude the + + align:start position:0% +the way I'm sorry your name is dude the + + + align:start position:0% +the way I'm sorry your name is dude the +way Hugo described it I think is nice a + + align:start position:0% +way Hugo described it I think is nice a + + + align:start position:0% +way Hugo described it I think is nice a +whole bunch of conditional statements + + align:start position:0% +whole bunch of conditional statements + + + align:start position:0% +whole bunch of conditional statements +which is the code so the code says if + + align:start position:0% +which is the code so the code says if + + + align:start position:0% +which is the code so the code says if +the plane leaves more than 30 minutes + + align:start position:0% +the plane leaves more than 30 minutes + + + align:start position:0% +the plane leaves more than 30 minutes +late then transfer $100 to his account + + align:start position:0% +late then transfer $100 to his account + + + align:start position:0% +late then transfer $100 to his account +okay so you don't trust Vitale's system + + align:start position:0% +okay so you don't trust Vitale's system + + + align:start position:0% +okay so you don't trust Vitale's system +to be able to implement that conditional + + align:start position:0% +to be able to implement that conditional + + + align:start position:0% +to be able to implement that conditional +yep I mean I don't know the code I don't + + align:start position:0% +yep I mean I don't know the code I don't + + + align:start position:0% +yep I mean I don't know the code I don't +know if it's breakable I don't know if + + align:start position:0% +know if it's breakable I don't know if + + + align:start position:0% +know if it's breakable I don't know if +GE can log in and change it you know + + align:start position:0% +GE can log in and change it you know + + + align:start position:0% +GE can log in and change it you know +this is true of everything you know when + + align:start position:0% +this is true of everything you know when + + + align:start position:0% +this is true of everything you know when +I say to you I'm a lawyer I'm gonna + + align:start position:0% +I say to you I'm a lawyer I'm gonna + + + align:start position:0% +I say to you I'm a lawyer I'm gonna +write the contract so you can sell your + + align:start position:0% +write the contract so you can sell your + + + align:start position:0% +write the contract so you can sell your +car to Andy + + align:start position:0% +car to Andy + + + align:start position:0% +car to Andy +you know you can have the same questions + + align:start position:0% +you know you can have the same questions + + + align:start position:0% +you know you can have the same questions +or you can enter the question whether + + align:start position:0% +or you can enter the question whether + + + align:start position:0% +or you can enter the question whether +Andy's gonna you know have a way to flip + + align:start position:0% +Andy's gonna you know have a way to flip + + + align:start position:0% +Andy's gonna you know have a way to flip +the price so instead of a ten thousand + + align:start position:0% +the price so instead of a ten thousand + + + align:start position:0% +the price so instead of a ten thousand +it's fifteen thousand so this + + align:start position:0% +it's fifteen thousand so this + + + align:start position:0% +it's fifteen thousand so this +uncertainty is everywhere it might be + + align:start position:0% +uncertainty is everywhere it might be + + + align:start position:0% +uncertainty is everywhere it might be +Vitaly would say actually there's a more + + align:start position:0% +Vitaly would say actually there's a more + + + align:start position:0% +Vitaly would say actually there's a more +robust way to verify my code than + + align:start position:0% +robust way to verify my code than + + + align:start position:0% +robust way to verify my code than +Lessing's contract because lessons + + align:start position:0% +Lessing's contract because lessons + + + align:start position:0% +Lessing's contract because lessons +contract code is written in English we + + align:start position:0% +contract code is written in English we + + + align:start position:0% +contract code is written in English we +have all sorts of but my code you can + + align:start position:0% +have all sorts of but my code you can + + + align:start position:0% +have all sorts of but my code you can +have independent people who verify so at + + align:start position:0% +have independent people who verify so at + + + align:start position:0% +have independent people who verify so at +the level of conditionals I'm pretty + + align:start position:0% +the level of conditionals I'm pretty + + + align:start position:0% +the level of conditionals I'm pretty +confident what I'm not confident about + + align:start position:0% +confident what I'm not confident about + + + align:start position:0% +confident what I'm not confident about +is and I had the great pleasure in + + align:start position:0% +is and I had the great pleasure in + + + align:start position:0% +is and I had the great pleasure in +December of 2015 + + align:start position:0% +December of 2015 + + + align:start position:0% +December of 2015 +spending a weekend with them like + + align:start position:0% +spending a weekend with them like + + + align:start position:0% +spending a weekend with them like +watching that group and you know it's + + align:start position:0% +watching that group and you know it's + + + align:start position:0% +watching that group and you know it's +this weird kind of you know he is like + + align:start position:0% +this weird kind of you know he is like + + + align:start position:0% +this weird kind of you know he is like +the Messiah figure and there's like + + align:start position:0% +the Messiah figure and there's like + + + align:start position:0% +the Messiah figure and there's like +twelve people sitting on the floor + + align:start position:0% +twelve people sitting on the floor + + + align:start position:0% +twelve people sitting on the floor +around him listening to his every bit of + + align:start position:0% +around him listening to his every bit of + + + align:start position:0% +around him listening to his every bit of +wisdom you know so it was inspirational + + align:start position:0% +wisdom you know so it was inspirational + + + align:start position:0% +wisdom you know so it was inspirational +and scary at the same time because you + + align:start position:0% +and scary at the same time because you + + + align:start position:0% +and scary at the same time because you +see how much money is resting on this + + align:start position:0% +see how much money is resting on this + + + align:start position:0% +see how much money is resting on this +Messiah structure but I have a lot of + + align:start position:0% +Messiah structure but I have a lot of + + + align:start position:0% +Messiah structure but I have a lot of +confidence in their ability to do the + + align:start position:0% +confidence in their ability to do the + + + align:start position:0% +confidence in their ability to do the +conditionals but I'm not so confident + + align:start position:0% +conditionals but I'm not so confident + + + align:start position:0% +conditionals but I'm not so confident +that they yet thought through how it + + align:start position:0% +that they yet thought through how it + + + align:start position:0% +that they yet thought through how it +plugs in to the bigger legal story and + + align:start position:0% +plugs in to the bigger legal story and + + + align:start position:0% +plugs in to the bigger legal story and +that's part of what I was trying to + + align:start position:0% +that's part of what I was trying to + + + align:start position:0% +that's part of what I was trying to +pitch to them is when I'm trying to him + + align:start position:0% +pitch to them is when I'm trying to him + + + align:start position:0% +pitch to them is when I'm trying to him +and that's what I'm trying to pitch to + + align:start position:0% +and that's what I'm trying to pitch to + + + align:start position:0% +and that's what I'm trying to pitch to +you that it's never gonna be the case + + align:start position:0% +you that it's never gonna be the case + + + align:start position:0% +you that it's never gonna be the case +it's not this conference in Australia + + align:start position:0% +it's not this conference in Australia + + + align:start position:0% +it's not this conference in Australia +where I met them and so many of the + + align:start position:0% +where I met them and so many of the + + + align:start position:0% +where I met them and so many of the +people there were speaking the way + + align:start position:0% +people there were speaking the way + + + align:start position:0% +people there were speaking the way +people spoke about the internet 20 years + + align:start position:0% +people spoke about the internet 20 years + + + align:start position:0% +people spoke about the internet 20 years +ago it's like oh there's like the real + + align:start position:0% +ago it's like oh there's like the real + + + align:start position:0% +ago it's like oh there's like the real +world we have the government's but we're + + align:start position:0% +world we have the government's but we're + + + align:start position:0% +world we have the government's but we're +gonna create like John Perry Barlow + + align:start position:0% +gonna create like John Perry Barlow + + + align:start position:0% +gonna create like John Perry Barlow +speak we're gonna trade this virtual + + align:start position:0% +speak we're gonna trade this virtual + + + align:start position:0% +speak we're gonna trade this virtual +world where there's no governments where + + align:start position:0% +world where there's no governments where + + + align:start position:0% +world where there's no governments where +we just live free of government and it's + + align:start position:0% +we just live free of government and it's + + + align:start position:0% +we just live free of government and it's +like so naive about the way this stuff + + align:start position:0% +like so naive about the way this stuff + + + align:start position:0% +like so naive about the way this stuff +works because it's always embedded in a + + align:start position:0% +works because it's always embedded in a + + + align:start position:0% +works because it's always embedded in a +real world which has a real government + + align:start position:0% +real world which has a real government + + + align:start position:0% +real world which has a real government +and that real government is not going to + + align:start position:0% +and that real government is not going to + + + align:start position:0% +and that real government is not going to +look the other way if you're you know + + align:start position:0% +look the other way if you're you know + + + align:start position:0% +look the other way if you're you know +doing lots of damage or not paying your + + align:start position:0% +doing lots of damage or not paying your + + + align:start position:0% +doing lots of damage or not paying your +taxes so the question isn't whether the + + align:start position:0% +taxes so the question isn't whether the + + + align:start position:0% +taxes so the question isn't whether the +question is just how and how much we go + + align:start position:0% +question is just how and how much we go + + + align:start position:0% +question is just how and how much we go +impact there what kind of implications + + align:start position:0% +impact there what kind of implications + + + align:start position:0% +impact there what kind of implications +you have do you think this technology + + align:start position:0% +you have do you think this technology + + + align:start position:0% +you have do you think this technology +has to broaden access to legal services + + align:start position:0% +has to broaden access to legal services + + + align:start position:0% +has to broaden access to legal services +and generally letting people know when + + align:start position:0% +and generally letting people know when + + + align:start position:0% +and generally letting people know when +they're being taken advantage or being + + align:start position:0% +they're being taken advantage or being + + + align:start position:0% +they're being taken advantage or being +able to like provide more standard + + align:start position:0% +able to like provide more standard + + + align:start position:0% +able to like provide more standard +versions of + + align:start position:0% +versions of + + + align:start position:0% +versions of +really call it contracts employment + + align:start position:0% +really call it contracts employment + + + align:start position:0% +really call it contracts employment +contracts or these contracts and things + + align:start position:0% +contracts or these contracts and things + + + align:start position:0% +contracts or these contracts and things +like that do you think that this is + + align:start position:0% +like that do you think that this is + + + align:start position:0% +like that do you think that this is +going to be a game-changer I mean you + + align:start position:0% +going to be a game-changer I mean you + + + align:start position:0% +going to be a game-changer I mean you +know you've got a muster the political + + align:start position:0% +know you've got a muster the political + + + align:start position:0% +know you've got a muster the political +will to break the monopoly lawyers have + + align:start position:0% +will to break the monopoly lawyers have + + + align:start position:0% +will to break the monopoly lawyers have +in this space and you know I'll tell you + + align:start position:0% +in this space and you know I'll tell you + + + align:start position:0% +in this space and you know I'll tell you +we're gonna fight hard against it but + + align:start position:0% +we're gonna fight hard against it but + + + align:start position:0% +we're gonna fight hard against it but +there is no reason for 90% of what + + align:start position:0% +there is no reason for 90% of what + + + align:start position:0% +there is no reason for 90% of what +lawyers do to be done by lawyers just + + align:start position:0% +lawyers do to be done by lawyers just + + + align:start position:0% +lawyers do to be done by lawyers just +like when you know go if you buy a house + + align:start position:0% +like when you know go if you buy a house + + + align:start position:0% +like when you know go if you buy a house +and you like have to have a lawyer who + + align:start position:0% +and you like have to have a lawyer who + + + align:start position:0% +and you like have to have a lawyer who +sits there and basically signs documents + + align:start position:0% +sits there and basically signs documents + + + align:start position:0% +sits there and basically signs documents +for you and you're like why and the + + align:start position:0% +for you and you're like why and the + + + align:start position:0% +for you and you're like why and the +answer is because the law has been + + align:start position:0% +answer is because the law has been + + + align:start position:0% +answer is because the law has been +written to require that person to sit + + align:start position:0% +written to require that person to sit + + + align:start position:0% +written to require that person to sit +there and sign documents and why because + + align:start position:0% +there and sign documents and why because + + + align:start position:0% +there and sign documents and why because +people get paid to sign documents have + + align:start position:0% +people get paid to sign documents have + + + align:start position:0% +people get paid to sign documents have +corrupted the law so so there's lots to + + align:start position:0% +corrupted the law so so there's lots to + + + align:start position:0% +corrupted the law so so there's lots to +clean up but if we could clean it up + + align:start position:0% +clean up but if we could clean it up + + + align:start position:0% +clean up but if we could clean it up +absolutely you know 99% of this stuff + + align:start position:0% +absolutely you know 99% of this stuff + + + align:start position:0% +absolutely you know 99% of this stuff +ought to be automatic and then let's get + + align:start position:0% +ought to be automatic and then let's get + + + align:start position:0% +ought to be automatic and then let's get +the lawyers to focus on the hard corner + + align:start position:0% +the lawyers to focus on the hard corner + + + align:start position:0% +the lawyers to focus on the hard corner +case it's not on the know everything + + align:start position:0% +case it's not on the know everything + + + align:start position:0% +case it's not on the know everything +should be automatic and that and that + + align:start position:0% +should be automatic and that and that + + + align:start position:0% +should be automatic and that and that +certainly should be true not just within + + align:start position:0% +certainly should be true not just within + + + align:start position:0% +certainly should be true not just within +a jurisdiction but across jurisdiction + + align:start position:0% +a jurisdiction but across jurisdiction + + + align:start position:0% +a jurisdiction but across jurisdiction +can I return to your insurance example I + + align:start position:0% +can I return to your insurance example I + + + align:start position:0% +can I return to your insurance example I +got the idea that you could write a + + align:start position:0% +got the idea that you could write a + + + align:start position:0% +got the idea that you could write a +smart contract that would pay you + + align:start position:0% +smart contract that would pay you + + + align:start position:0% +smart contract that would pay you +automatically planes just later but then + + align:start position:0% +automatically planes just later but then + + + align:start position:0% +automatically planes just later but then +you said it puts it on the clock that + + align:start position:0% +you said it puts it on the clock that + + + align:start position:0% +you said it puts it on the clock that +can you connect why he put it on a + + align:start position:0% +can you connect why he put it on a + + + align:start position:0% +can you connect why he put it on a +blockchain as opposed to just putting it + + align:start position:0% +blockchain as opposed to just putting it + + + align:start position:0% +blockchain as opposed to just putting it +on his disk and letting your credit card + + align:start position:0% +on his disk and letting your credit card + + + align:start position:0% +on his disk and letting your credit card +get credited I mean where did the + + align:start position:0% +get credited I mean where did the + + + align:start position:0% +get credited I mean where did the +blockchain + + align:start position:0% +blockchain + + + align:start position:0% +blockchain +enter into that and why did he need a + + align:start position:0% +enter into that and why did he need a + + + align:start position:0% +enter into that and why did he need a +blockchain in order to maintain that + + align:start position:0% +blockchain in order to maintain that + + + align:start position:0% +blockchain in order to maintain that +state thing that he thought he was + + align:start position:0% +state thing that he thought he was + + + align:start position:0% +state thing that he thought he was +getting out of the blockchain is to + + align:start position:0% +getting out of the blockchain is to + + + align:start position:0% +getting out of the blockchain is to +increase the verify ability of third + + align:start position:0% +increase the verify ability of third + + + align:start position:0% +increase the verify ability of third +parties of the actual payments according + + align:start position:0% +parties of the actual payments according + + + align:start position:0% +parties of the actual payments according +to the data so if I say to you I'm gonna + + align:start position:0% +to the data so if I say to you I'm gonna + + + align:start position:0% +to the data so if I say to you I'm gonna +be paying you 500 dollars if you're + + align:start position:0% +be paying you 500 dollars if you're + + + align:start position:0% +be paying you 500 dollars if you're +playing as an hour late and we have the + + align:start position:0% +playing as an hour late and we have the + + + align:start position:0% +playing as an hour late and we have the +data out there about the planes being + + align:start position:0% +data out there about the planes being + + + align:start position:0% +data out there about the planes being +late if he did it inside of his + + align:start position:0% +late if he did it inside of his + + + align:start position:0% +late if he did it inside of his +insurance company I wouldn't have any + + align:start position:0% +insurance company I wouldn't have any + + + align:start position:0% +insurance company I wouldn't have any +way to know that he paid you 500 dollars + + align:start position:0% +way to know that he paid you 500 dollars + + + align:start position:0% +way to know that he paid you 500 dollars +for the plane being late but if it's in + + align:start position:0% +for the plane being late but if it's in + + + align:start position:0% +for the plane being late but if it's in +a blog chain there's at least + + align:start position:0% +a blog chain there's at least + + + align:start position:0% +a blog chain there's at least +conceptually a way in which we could be + + align:start position:0% +conceptually a way in which we could be + + + align:start position:0% +conceptually a way in which we could be +doing this + + align:start position:0% +doing this + + + align:start position:0% +doing this +not that I'm revealing it to you but we + + align:start position:0% +not that I'm revealing it to you but we + + + align:start position:0% +not that I'm revealing it to you but we +could be signaling Apollo that depends + + align:start position:0% +could be signaling Apollo that depends + + + align:start position:0% +could be signaling Apollo that depends +on who maintains the knowledge chain and + + align:start position:0% +on who maintains the knowledge chain and + + + align:start position:0% +on who maintains the knowledge chain and +at the same time and return to that + + align:start position:0% +at the same time and return to that + + + align:start position:0% +at the same time and return to that +suddenly everybody knows the cash flow + + align:start position:0% +suddenly everybody knows the cash flow + + + align:start position:0% +suddenly everybody knows the cash flow +of that insurance company which is + + align:start position:0% +of that insurance company which is + + + align:start position:0% +of that insurance company which is +likely not something he wants to do + + align:start position:0% +likely not something he wants to do + + + align:start position:0% +likely not something he wants to do +companies bigger than authenticating the + + align:start position:0% +companies bigger than authenticating the + + + align:start position:0% +companies bigger than authenticating the +truth about certain types of my do not + + align:start position:0% +truth about certain types of my do not + + + align:start position:0% +truth about certain types of my do not +want everybody to know what planes I'm + + align:start position:0% +want everybody to know what planes I'm + + + align:start position:0% +want everybody to know what planes I'm +flying + + align:start position:0% +flying + + + align:start position:0% +flying +so you've implied that there's now a + + align:start position:0% +so you've implied that there's now a + + + align:start position:0% +so you've implied that there's now a +public no all I mean to all I need to + + align:start position:0% +public no all I mean to all I need to + + + align:start position:0% +public no all I mean to all I need to +argue and I didn't interrogate him far I + + align:start position:0% +argue and I didn't interrogate him far I + + + align:start position:0% +argue and I didn't interrogate him far I +was just taking his statement that he's + + align:start position:0% +was just taking his statement that he's + + + align:start position:0% +was just taking his statement that he's +doing so I'm trying to think why would + + align:start position:0% +doing so I'm trying to think why would + + + align:start position:0% +doing so I'm trying to think why would +he want to do it because I had the same + + align:start position:0% +he want to do it because I had the same + + + align:start position:0% +he want to do it because I had the same +kind of question you want to do you had + + align:start position:0% +kind of question you want to do you had + + + align:start position:0% +kind of question you want to do you had +and it's just that if you are trying to + + align:start position:0% +and it's just that if you are trying to + + + align:start position:0% +and it's just that if you are trying to +create credibility around your claim do + + align:start position:0% +create credibility around your claim do + + + align:start position:0% +create credibility around your claim do +I have a reason to trust this insurance + + align:start position:0% +I have a reason to trust this insurance + + + align:start position:0% +I have a reason to trust this insurance +company that in fact it's going to be + + align:start position:0% +company that in fact it's going to be + + + align:start position:0% +company that in fact it's going to be +doing this then there's some + + align:start position:0% +doing this then there's some + + + align:start position:0% +doing this then there's some +transparency that this enables not + + align:start position:0% +transparency that this enables not + + + align:start position:0% +transparency that this enables not +necessarily the transparency of your + + align:start position:0% +necessarily the transparency of your + + + align:start position:0% +necessarily the transparency of your +credit card number or your name or the + + align:start position:0% +credit card number or your name or the + + + align:start position:0% +credit card number or your name or the +flights that you're taking but that + + align:start position:0% +flights that you're taking but that + + + align:start position:0% +flights that you're taking but that +there was somebody who was on this who + + align:start position:0% +there was somebody who was on this who + + + align:start position:0% +there was somebody who was on this who +had a contract and we then made this + + align:start position:0% +had a contract and we then made this + + + align:start position:0% +had a contract and we then made this +kind of payment it might that would be a + + align:start position:0% +kind of payment it might that would be a + + + align:start position:0% +kind of payment it might that would be a +potential value that he has now if + + align:start position:0% +potential value that he has now if + + + align:start position:0% +potential value that he has now if +there's no value from that then you're + + align:start position:0% +there's no value from that then you're + + + align:start position:0% +there's no value from that then you're +right the overhead of the blockchain or + + align:start position:0% +right the overhead of the blockchain or + + + align:start position:0% +right the overhead of the blockchain or +public or private or whatever is too + + align:start position:0% +public or private or whatever is too + + + align:start position:0% +public or private or whatever is too +high and he just could do it inside and + + align:start position:0% +high and he just could do it inside and + + + align:start position:0% +high and he just could do it inside and +for certain companies like you know if + + align:start position:0% +for certain companies like you know if + + + align:start position:0% +for certain companies like you know if +you went to a credible insurance company + + align:start position:0% +you went to a credible insurance company + + + align:start position:0% +you went to a credible insurance company +the credible insurance company you know + + align:start position:0% +the credible insurance company you know + + + align:start position:0% +the credible insurance company you know +you probably trust that credible + + align:start position:0% +you probably trust that credible + + + align:start position:0% +you probably trust that credible +insurance company but again if you're a + + align:start position:0% +insurance company but again if you're a + + + align:start position:0% +insurance company but again if you're a +not credible insurance company if you're + + align:start position:0% +not credible insurance company if you're + + + align:start position:0% +not credible insurance company if you're +a startup and you are out there in the + + align:start position:0% +a startup and you are out there in the + + + align:start position:0% +a startup and you are out there in the +market and you're saying give me your + + align:start position:0% +market and you're saying give me your + + + align:start position:0% +market and you're saying give me your +money and I'll pay you if the planes + + align:start position:0% +money and I'll pay you if the planes + + + align:start position:0% +money and I'll pay you if the planes +late people are gonna say why should I + + align:start position:0% +late people are gonna say why should I + + + align:start position:0% +late people are gonna say why should I +trust you and you're like well here you + + align:start position:0% +trust you and you're like well here you + + + align:start position:0% +trust you and you're like well here you +don't really have to trust me here's the + + align:start position:0% +don't really have to trust me here's the + + + align:start position:0% +don't really have to trust me here's the +data to democratical way than if I just + + align:start position:0% +data to democratical way than if I just + + + align:start position:0% +data to democratical way than if I just +published a report on my website that + + align:start position:0% +published a report on my website that + + + align:start position:0% +published a report on my website that +I'm doing what I say on to it let me + + align:start position:0% +I'm doing what I say on to it let me + + + align:start position:0% +I'm doing what I say on to it let me +strut it Andy let's try to get a couple + + align:start position:0% +strut it Andy let's try to get a couple + + + align:start position:0% +strut it Andy let's try to get a couple +more questions but my hunch is that it's + + align:start position:0% +more questions but my hunch is that it's + + + align:start position:0% +more questions but my hunch is that it's +probably a permission rather than + + align:start position:0% +probably a permission rather than + + + align:start position:0% +probably a permission rather than +permission list blockchain and and it + + align:start position:0% +permission list blockchain and and it + + + align:start position:0% +permission list blockchain and and it +may be the insurance company wants to + + align:start position:0% +may be the insurance company wants to + + + align:start position:0% +may be the insurance company wants to +ride on the buzz of blockchain but it's + + align:start position:0% +ride on the buzz of blockchain but it's + + + align:start position:0% +ride on the buzz of blockchain but it's +possible also that he thinks that + + align:start position:0% +possible also that he thinks that + + + align:start position:0% +possible also that he thinks that +there'll be more trust that consumers + + align:start position:0% +there'll be more trust that consumers + + + align:start position:0% +there'll be more trust that consumers +will trust it if it's called a block J + + align:start position:0% +will trust it if it's called a block J + + + align:start position:0% +will trust it if it's called a block J +so it's but you didn't interview + + align:start position:0% +so it's but you didn't interview + + + align:start position:0% +so it's but you didn't interview +you can pick who you want to write this + + align:start position:0% +you can pick who you want to write this + + + align:start position:0% +you can pick who you want to write this +whole smart conscience solvent + + align:start position:0% +whole smart conscience solvent + + + align:start position:0% +whole smart conscience solvent +submarines in some countries would + + align:start position:0% +submarines in some countries would + + + align:start position:0% +submarines in some countries would +receive and I was talking to in context + + align:start position:0% +receive and I was talking to in context + + + align:start position:0% +receive and I was talking to in context +or something like that yeah if you have + + align:start position:0% +or something like that yeah if you have + + + align:start position:0% +or something like that yeah if you have +an alternative way to credibly represent + + align:start position:0% +an alternative way to credibly represent + + + align:start position:0% +an alternative way to credibly represent +a fact and again this is kind of + + align:start position:0% +a fact and again this is kind of + + + align:start position:0% +a fact and again this is kind of +connected to Andy's point like what is + + align:start position:0% +connected to Andy's point like what is + + + align:start position:0% +connected to Andy's point like what is +this and is there an alternative way and + + align:start position:0% +this and is there an alternative way and + + + align:start position:0% +this and is there an alternative way and +is this the alternative way then you + + align:start position:0% +is this the alternative way then you + + + align:start position:0% +is this the alternative way then you +lower the transaction cost of that kind + + align:start position:0% +lower the transaction cost of that kind + + + align:start position:0% +lower the transaction cost of that kind +of contract because I'm going to trust + + align:start position:0% +of contract because I'm going to trust + + + align:start position:0% +of contract because I'm going to trust +the contracting process more if I'm + + align:start position:0% +the contracting process more if I'm + + + align:start position:0% +the contracting process more if I'm +confident that in fact the the fact that + + align:start position:0% +confident that in fact the the fact that + + + align:start position:0% +confident that in fact the the fact that +I'm late I'm not late it doesn't + + align:start position:0% +I'm late I'm not late it doesn't + + + align:start position:0% +I'm late I'm not late it doesn't +penalize me or you don't penalize me + + align:start position:0% +penalize me or you don't penalize me + + + align:start position:0% +penalize me or you don't penalize me +claiming I'm late so to the extent you + + align:start position:0% +claiming I'm late so to the extent you + + + align:start position:0% +claiming I'm late so to the extent you +lower the cost of verifying facts in the + + align:start position:0% +lower the cost of verifying facts in the + + + align:start position:0% +lower the cost of verifying facts in the +world you increase the opportunity for + + align:start position:0% +world you increase the opportunity for + + + align:start position:0% +world you increase the opportunity for +certain contracts to happen who + + align:start position:0% +certain contracts to happen who + + + align:start position:0% +certain contracts to happen who +otherwise wouldn't have and and that's + + align:start position:0% +otherwise wouldn't have and and that's + + + align:start position:0% +otherwise wouldn't have and and that's +the only trade-off that I'm trying to + + align:start position:0% +the only trade-off that I'm trying to + + + align:start position:0% +the only trade-off that I'm trying to +emphasize by emphasizing the transaction + + align:start position:0% +emphasize by emphasizing the transaction + + + align:start position:0% +emphasize by emphasizing the transaction +cost apart from these contracts you had + + align:start position:0% +cost apart from these contracts you had + + + align:start position:0% +cost apart from these contracts you had +a question + + align:start position:0% + + + + align:start position:0% + +not for one-off transactions before the + + align:start position:0% +not for one-off transactions before the + + + align:start position:0% +not for one-off transactions before the +insurance company aggregate thousands of + + align:start position:0% +insurance company aggregate thousands of + + + align:start position:0% +insurance company aggregate thousands of +transactions where they've shown + + align:start position:0% +transactions where they've shown + + + align:start position:0% +transactions where they've shown +performance they can use this ethical or + + align:start position:0% +performance they can use this ethical or + + + align:start position:0% +performance they can use this ethical or +commercial reasons to show that yes + + align:start position:0% +commercial reasons to show that yes + + + align:start position:0% +commercial reasons to show that yes +people get paid when + + align:start position:0% + + + + align:start position:0% + +ridiculous yeah you would free that it + + align:start position:0% +ridiculous yeah you would free that it + + + align:start position:0% +ridiculous yeah you would free that it +would have to be that that would be a + + align:start position:0% +would have to be that that would be a + + + align:start position:0% +would have to be that that would be a +value it was providing otherwise to be + + align:start position:0% +value it was providing otherwise to be + + + align:start position:0% +value it was providing otherwise to be +Eddie's point there would be no reason + + align:start position:0% +Eddie's point there would be no reason + + + align:start position:0% +Eddie's point there would be no reason +to adopt that's gonna go on the back + + align:start position:0% +to adopt that's gonna go on the back + + + align:start position:0% +to adopt that's gonna go on the back +right I don't remember a name so with + + align:start position:0% +right I don't remember a name so with + + + align:start position:0% +right I don't remember a name so with +it's easier access to these kind of + + align:start position:0% +it's easier access to these kind of + + + align:start position:0% +it's easier access to these kind of +derivative contracts do you proceed a + + align:start position:0% +derivative contracts do you proceed a + + + align:start position:0% +derivative contracts do you proceed a +world where there's a lot more leverage + + align:start position:0% +world where there's a lot more leverage + + + align:start position:0% +world where there's a lot more leverage +and sort of any type of market outside + + align:start position:0% +and sort of any type of market outside + + + align:start position:0% +and sort of any type of market outside +of financial markets or see this + + align:start position:0% +of financial markets or see this + + + align:start position:0% +of financial markets or see this +creating risk this is your expertise + + align:start position:0% +creating risk this is your expertise + + + align:start position:0% +creating risk this is your expertise +right because I mean we already saw in + + align:start position:0% +right because I mean we already saw in + + + align:start position:0% +right because I mean we already saw in +the derivatives market the fact that the + + align:start position:0% +the derivatives market the fact that the + + + align:start position:0% +the derivatives market the fact that the +choice by policymakers was to allow it + + align:start position:0% +choice by policymakers was to allow it + + + align:start position:0% +choice by policymakers was to allow it +to be an invisible market and not to + + align:start position:0% +to be an invisible market and not to + + + align:start position:0% +to be an invisible market and not to +regulate that market created all sorts + + align:start position:0% +regulate that market created all sorts + + + align:start position:0% +regulate that market created all sorts +of risks that you know people might + + align:start position:0% +of risks that you know people might + + + align:start position:0% +of risks that you know people might +think shouldn't have been there and I + + align:start position:0% +think shouldn't have been there and I + + + align:start position:0% +think shouldn't have been there and I +think the same potential is here which + + align:start position:0% +think the same potential is here which + + + align:start position:0% +think the same potential is here which +is again to come back to the point don't + + align:start position:0% +is again to come back to the point don't + + + align:start position:0% +is again to come back to the point don't +expect there not to be government here I + + align:start position:0% +expect there not to be government here I + + + align:start position:0% +expect there not to be government here I +mean you know to the extent people + + align:start position:0% +mean you know to the extent people + + + align:start position:0% +mean you know to the extent people +realize this risk and don't have as much + + align:start position:0% +realize this risk and don't have as much + + + align:start position:0% +realize this risk and don't have as much +political corrupting power as Wall + + align:start position:0% +political corrupting power as Wall + + + align:start position:0% +political corrupting power as Wall +Street did in our system I would say yes + + align:start position:0% +Street did in our system I would say yes + + + align:start position:0% +Street did in our system I would say yes +even on Bitcoin you can create something + + align:start position:0% +even on Bitcoin you can create something + + + align:start position:0% +even on Bitcoin you can create something +called discrete log contracts to do + + align:start position:0% +called discrete log contracts to do + + + align:start position:0% +called discrete log contracts to do +contracts for differences or derivatives + + align:start position:0% +contracts for differences or derivatives + + + align:start position:0% +contracts for differences or derivatives +but with smart contracts you can put a + + align:start position:0% +but with smart contracts you can put a + + + align:start position:0% +but with smart contracts you can put a +lot of leverage into the system and + + align:start position:0% +lot of leverage into the system and + + + align:start position:0% +lot of leverage into the system and +transactions can move quickly so I think + + align:start position:0% +transactions can move quickly so I think + + + align:start position:0% +transactions can move quickly so I think +the state will have an interest + + align:start position:0% +the state will have an interest + + + align:start position:0% +the state will have an interest +particularly if it grows you probably + + align:start position:0% +particularly if it grows you probably + + + align:start position:0% +particularly if it grows you probably +only have time for two more questions + + align:start position:0% +only have time for two more questions + + + align:start position:0% +only have time for two more questions +and I'm still wondering how do courts + + align:start position:0% +and I'm still wondering how do courts + + + align:start position:0% +and I'm still wondering how do courts +currently look at these as a matter of + + align:start position:0% +currently look at these as a matter of + + + align:start position:0% +currently look at these as a matter of +law and the late 1990s I was honored to + + align:start position:0% +law and the late 1990s I was honored to + + + align:start position:0% +law and the late 1990s I was honored to +work with Senator John McCain on + + align:start position:0% +work with Senator John McCain on + + + align:start position:0% +work with Senator John McCain on +something which became the e-signature + + align:start position:0% +something which became the e-signature + + + align:start position:0% +something which became the e-signature +law I was just playing point for the US + + align:start position:0% +law I was just playing point for the US + + + align:start position:0% +law I was just playing point for the US +Department of Treasury it was really + + align:start position:0% +Department of Treasury it was really + + + align:start position:0% +Department of Treasury it was really +John McCain's law Congress was doing but + + align:start position:0% +John McCain's law Congress was doing but + + + align:start position:0% +John McCain's law Congress was doing but +I'm wondering how the courts today would + + align:start position:0% +I'm wondering how the courts today would + + + align:start position:0% +I'm wondering how the courts today would +see these contracts is it like do we + + align:start position:0% +see these contracts is it like do we + + + align:start position:0% +see these contracts is it like do we +need something like them a signature law + + align:start position:0% +need something like them a signature law + + + align:start position:0% +need something like them a signature law +to have code accepted beyond what ecig + + align:start position:0% +to have code accepted beyond what ecig + + + align:start position:0% +to have code accepted beyond what ecig +mature + + align:start position:0% +mature + + + align:start position:0% +mature +no I think easy I think the e-signature + + align:start position:0% +no I think easy I think the e-signature + + + align:start position:0% +no I think easy I think the e-signature +infrastructure is going to be 99 percent + + align:start position:0% +infrastructure is going to be 99 percent + + + align:start position:0% +infrastructure is going to be 99 percent +of what you mean that which I worked 120 + + align:start position:0% +of what you mean that which I worked 120 + + + align:start position:0% +of what you mean that which I worked 120 +years ago little did I know - yeah I + + align:start position:0% +years ago little did I know - yeah I + + + align:start position:0% +years ago little did I know - yeah I +mean because there's no there's no + + align:start position:0% +mean because there's no there's no + + + align:start position:0% +mean because there's no there's no +that's why I wanted to wrap this around + + align:start position:0% +that's why I wanted to wrap this around + + + align:start position:0% +that's why I wanted to wrap this around +the idea of a soda pop it's like it's + + align:start position:0% +the idea of a soda pop it's like it's + + + align:start position:0% +the idea of a soda pop it's like it's +nothing new in some sense contract law + + align:start position:0% +nothing new in some sense contract law + + + align:start position:0% +nothing new in some sense contract law +has always dealt with machines that are + + align:start position:0% +has always dealt with machines that are + + + align:start position:0% +has always dealt with machines that are +delivering on obligations it's just a + + align:start position:0% +delivering on obligations it's just a + + + align:start position:0% +delivering on obligations it's just a +more sophisticated set of proves you're + + align:start position:0% +more sophisticated set of proves you're + + + align:start position:0% +more sophisticated set of proves you're +gonna have to make in the court but it's + + align:start position:0% +gonna have to make in the court but it's + + + align:start position:0% +gonna have to make in the court but it's +the same underlying one more question I + + align:start position:0% +the same underlying one more question I + + + align:start position:0% +the same underlying one more question I +mean it's just we're supposed to we + + align:start position:0% +mean it's just we're supposed to we + + + align:start position:0% +mean it's just we're supposed to we +always we're MIT we supposed to end five + + align:start position:0% +always we're MIT we supposed to end five + + + align:start position:0% +always we're MIT we supposed to end five +minutes early + + align:start position:0% +minutes early + + + align:start position:0% +minutes early +okay I don't know what you do it or I + + align:start position:0% +okay I don't know what you do it or I + + + align:start position:0% +okay I don't know what you do it or I +don't remember yeah it's Harvard Law you + + align:start position:0% +don't remember yeah it's Harvard Law you + + + align:start position:0% +don't remember yeah it's Harvard Law you +know question from Elan which is a lot + + align:start position:0% +know question from Elan which is a lot + + + align:start position:0% +know question from Elan which is a lot +of the contracts you're talking about + + align:start position:0% +of the contracts you're talking about + + + align:start position:0% +of the contracts you're talking about +simple contracts right you've got + + align:start position:0% +simple contracts right you've got + + + align:start position:0% +simple contracts right you've got +individuals on one side got large + + align:start position:0% +individuals on one side got large + + + align:start position:0% +individuals on one side got large +companies like your insurance company + + align:start position:0% +companies like your insurance company + + + align:start position:0% +companies like your insurance company +other the insurance company can't in + + align:start position:0% +other the insurance company can't in + + + align:start position:0% +other the insurance company can't in +fact go through the entire decision tree + + align:start position:0% +fact go through the entire decision tree + + + align:start position:0% +fact go through the entire decision tree +and decide what every term is in their + + align:start position:0% +and decide what every term is in their + + + align:start position:0% +and decide what every term is in their +favor and the law deals with that all + + align:start position:0% +favor and the law deals with that all + + + align:start position:0% +favor and the law deals with that all +the time but here you have another + + align:start position:0% +the time but here you have another + + + align:start position:0% +the time but here you have another +problem which is now it's going to be + + align:start position:0% +problem which is now it's going to be + + + align:start position:0% +problem which is now it's going to be +okay it's going to be written computer + + align:start position:0% +okay it's going to be written computer + + + align:start position:0% +okay it's going to be written computer +code how the judge is going to deal with + + align:start position:0% +code how the judge is going to deal with + + + align:start position:0% +code how the judge is going to deal with +that now it's in a language that is + + align:start position:0% +that now it's in a language that is + + + align:start position:0% +that now it's in a language that is +going to be even tougher to deal with + + align:start position:0% +going to be even tougher to deal with + + + align:start position:0% +going to be even tougher to deal with +that problem and the answer is so this + + align:start position:0% +that problem and the answer is so this + + + align:start position:0% +that problem and the answer is so this +is actually a another version of your + + align:start position:0% +is actually a another version of your + + + align:start position:0% +is actually a another version of your +question the answer to that is nobody + + align:start position:0% +question the answer to that is nobody + + + align:start position:0% +question the answer to that is nobody +knows right now and so this issue gets + + align:start position:0% +knows right now and so this issue gets + + + align:start position:0% +knows right now and so this issue gets +raised in a lot of parallel contexts for + + align:start position:0% +raised in a lot of parallel contexts for + + + align:start position:0% +raised in a lot of parallel contexts for +example there's a Supreme Court justice + + align:start position:0% +example there's a Supreme Court justice + + + align:start position:0% +example there's a Supreme Court justice +from California who's doing a lot of + + align:start position:0% +from California who's doing a lot of + + + align:start position:0% +from California who's doing a lot of +work about the question of black boxes + + align:start position:0% +work about the question of black boxes + + + align:start position:0% +work about the question of black boxes +that predict whether you are likely to + + align:start position:0% +that predict whether you are likely to + + + align:start position:0% +that predict whether you are likely to +commit a crime again so like if you're + + align:start position:0% +commit a crime again so like if you're + + + align:start position:0% +commit a crime again so like if you're +convicted of crime the question is well + + align:start position:0% +convicted of crime the question is well + + + align:start position:0% +convicted of crime the question is well +you're gonna have parole the parole juh + + align:start position:0% +you're gonna have parole the parole juh + + + align:start position:0% +you're gonna have parole the parole juh +the parole process is supposed to decide + + align:start position:0% +the parole process is supposed to decide + + + align:start position:0% +the parole process is supposed to decide +your likelihood of committing a crime so + + align:start position:0% +your likelihood of committing a crime so + + + align:start position:0% +your likelihood of committing a crime so +these companies have built these black + + align:start position:0% +these companies have built these black + + + align:start position:0% +these companies have built these black +boxes where you spit in every bit of + + align:start position:0% +boxes where you spit in every bit of + + + align:start position:0% +boxes where you spit in every bit of +data and it comes out and says yes + + align:start position:0% +data and it comes out and says yes + + + align:start position:0% +data and it comes out and says yes +you're a criminal or no you're not and + + align:start position:0% +you're a criminal or no you're not and + + + align:start position:0% +you're a criminal or no you're not and +then the lawyers come forward they say + + align:start position:0% +then the lawyers come forward they say + + + align:start position:0% +then the lawyers come forward they say +well I want to interrogate the black box + + align:start position:0% +well I want to interrogate the black box + + + align:start position:0% +well I want to interrogate the black box +I want to know what and the courts are + + align:start position:0% +I want to know what and the courts are + + + align:start position:0% +I want to know what and the courts are +come + + align:start position:0% +come + + + align:start position:0% +come +confused about this because on the one + + align:start position:0% +confused about this because on the one + + + align:start position:0% +confused about this because on the one +hand they say no no this is their trade + + align:start position:0% +hand they say no no this is their trade + + + align:start position:0% +hand they say no no this is their trade +secret but on the other hand they're + + align:start position:0% +secret but on the other hand they're + + + align:start position:0% +secret but on the other hand they're +like wait wait a minute you can't decide + + align:start position:0% +like wait wait a minute you can't decide + + + align:start position:0% +like wait wait a minute you can't decide +whether I have Liberty or not based on + + align:start position:0% +whether I have Liberty or not based on + + + align:start position:0% +whether I have Liberty or not based on +these black boxes that just spit out + + align:start position:0% +these black boxes that just spit out + + + align:start position:0% +these black boxes that just spit out +numbers right so I've got to be able to + + align:start position:0% +numbers right so I've got to be able to + + + align:start position:0% +numbers right so I've got to be able to +interrogate right so this is the most + + align:start position:0% +interrogate right so this is the most + + + align:start position:0% +interrogate right so this is the most +important innovation that's got to + + align:start position:0% +important innovation that's got to + + + align:start position:0% +important innovation that's got to +happen in law lawyers have to become + + align:start position:0% +happen in law lawyers have to become + + + align:start position:0% +happen in law lawyers have to become +technically sophisticated to be able to + + align:start position:0% +technically sophisticated to be able to + + + align:start position:0% +technically sophisticated to be able to +read code like they read legal contracts + + align:start position:0% +read code like they read legal contracts + + + align:start position:0% +read code like they read legal contracts +they have to have a conceptual + + align:start position:0% +they have to have a conceptual + + + align:start position:0% +they have to have a conceptual +understanding of what code can do so + + align:start position:0% +understanding of what code can do so + + + align:start position:0% +understanding of what code can do so +they can think creatively about code + + align:start position:0% +they can think creatively about code + + + align:start position:0% +they can think creatively about code +like they think creatively about + + align:start position:0% +like they think creatively about + + + align:start position:0% +like they think creatively about +language right and one of the most + + align:start position:0% +language right and one of the most + + + align:start position:0% +language right and one of the most +important innovations that we you know + + align:start position:0% +important innovations that we you know + + + align:start position:0% +important innovations that we you know +like we'd like the Berkman Center and + + align:start position:0% +like we'd like the Berkman Center and + + + align:start position:0% +like we'd like the Berkman Center and +people like that are trying to push into + + align:start position:0% +people like that are trying to push into + + + align:start position:0% +people like that are trying to push into +the legal environment is to insist that + + align:start position:0% +the legal environment is to insist that + + + align:start position:0% +the legal environment is to insist that +just like lawyers now all study + + align:start position:0% +just like lawyers now all study + + + align:start position:0% +just like lawyers now all study +economics because that's a core way of + + align:start position:0% +economics because that's a core way of + + + align:start position:0% +economics because that's a core way of +thinking about the law we also should + + align:start position:0% +thinking about the law we also should + + + align:start position:0% +thinking about the law we also should +study basic code so we should can think + + align:start position:0% +study basic code so we should can think + + + align:start position:0% +study basic code so we should can think +about this modality of regulation not to + + align:start position:0% +about this modality of regulation not to + + + align:start position:0% +about this modality of regulation not to +expect people to be writing code but at + + align:start position:0% +expect people to be writing code but at + + + align:start position:0% +expect people to be writing code but at +least that they can think through it so + + align:start position:0% +least that they can think through it so + + + align:start position:0% +least that they can think through it so +I completely agree that's a that's a you + + align:start position:0% +I completely agree that's a that's a you + + + align:start position:0% +I completely agree that's a that's a you +know a fudge States that I didn't talk + + align:start position:0% +know a fudge States that I didn't talk + + + align:start position:0% +know a fudge States that I didn't talk +about at all but I think it's a really + + align:start position:0% +about at all but I think it's a really + + + align:start position:0% +about at all but I think it's a really +important problem thinking about whether + + align:start position:0% +important problem thinking about whether + + + align:start position:0% +important problem thinking about whether +the legal system is gonna be able to + + align:start position:0% +the legal system is gonna be able to + + + align:start position:0% +the legal system is gonna be able to +deal with it because if none of the + + align:start position:0% +deal with it because if none of the + + + align:start position:0% +deal with it because if none of the +lawyers understand it I'm yeah let me + + align:start position:0% +lawyers understand it I'm yeah let me + + + align:start position:0% +lawyers understand it I'm yeah let me +just end with one story about that so + + align:start position:0% +just end with one story about that so + + + align:start position:0% +just end with one story about that so +when I first started doing this work + + align:start position:0% +when I first started doing this work + + + align:start position:0% +when I first started doing this work +talking about code and regular I went to + + align:start position:0% +talking about code and regular I went to + + + align:start position:0% +talking about code and regular I went to +Paris 20 years ago and I gave a speech + + align:start position:0% +Paris 20 years ago and I gave a speech + + + align:start position:0% +Paris 20 years ago and I gave a speech +to some lawyer group and I sat down + + align:start position:0% +to some lawyer group and I sat down + + + align:start position:0% +to some lawyer group and I sat down +after the speech and the chairman of + + align:start position:0% +after the speech and the chairman of + + + align:start position:0% +after the speech and the chairman of +this buccal group sat down next to me + + align:start position:0% +this buccal group sat down next to me + + + align:start position:0% +this buccal group sat down next to me +and I introduced myself and he stood up + + align:start position:0% +and I introduced myself and he stood up + + + align:start position:0% +and I introduced myself and he stood up +and he grabbed my card and he crushed it + + align:start position:0% +and he grabbed my card and he crushed it + + + align:start position:0% +and he grabbed my card and he crushed it +and he threw it to the ground and he + + align:start position:0% +and he threw it to the ground and he + + + align:start position:0% +and he threw it to the ground and he +said I am NOT a technician and his point + + align:start position:0% +said I am NOT a technician and his point + + + align:start position:0% +said I am NOT a technician and his point +was he is a lawyer could never accept + + align:start position:0% +was he is a lawyer could never accept + + + align:start position:0% +was he is a lawyer could never accept +the idea that what he needed to + + align:start position:0% +the idea that what he needed to + + + align:start position:0% +the idea that what he needed to +understand was code like that was + + align:start position:0% +understand was code like that was + + + align:start position:0% +understand was code like that was +forbidden it was beneath him and I think + + align:start position:0% +forbidden it was beneath him and I think + + + align:start position:0% +forbidden it was beneath him and I think +it's a you know it's a hugely important + + align:start position:0% +it's a you know it's a hugely important + + + align:start position:0% +it's a you know it's a hugely important +cultural problem - like integrate this + + align:start position:0% +cultural problem - like integrate this + + + align:start position:0% +cultural problem - like integrate this +form of knowledge because if we don't + + align:start position:0% +form of knowledge because if we don't + + + align:start position:0% +form of knowledge because if we don't +then the problem you're talking about is + + align:start position:0% +then the problem you're talking about is + + + align:start position:0% +then the problem you're talking about is +really a huge problem but I think we can + + align:start position:0% +really a huge problem but I think we can + + + align:start position:0% +really a huge problem but I think we can +because we've seen last + + align:start position:0% +because we've seen last + + + align:start position:0% +because we've seen last +so I want to thank you on behalf of the + + align:start position:0% +so I want to thank you on behalf of the + + + align:start position:0% +so I want to thank you on behalf of the +class blockchain money I also want to + + align:start position:0% +class blockchain money I also want to + + + align:start position:0% +class blockchain money I also want to +say you're much better than Christopher + + align:start position:0% +say you're much better than Christopher + + + align:start position:0% +say you're much better than Christopher +Lloyd if anybody wants to know the joke + + align:start position:0% +Lloyd if anybody wants to know the joke + + + align:start position:0% +Lloyd if anybody wants to know the joke +watch that West weaning episode that + + align:start position:0% +watch that West weaning episode that + + + align:start position:0% +watch that West weaning episode that +Christopher Lloyd plays Professor + + align:start position:0% +Christopher Lloyd plays Professor + + + align:start position:0% +Christopher Lloyd plays Professor +Lawrence Lessig so thank you see you on + + align:start position:0% +Lawrence Lessig so thank you see you on + + + align:start position:0% +Lawrence Lessig so thank you see you on +Thursday + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/K1w2o5i0NGQ.txt b/K1w2o5i0NGQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..30ba702af931298ab6ff1f3f2f770eb7bb096efa --- /dev/null +++ b/K1w2o5i0NGQ.txt @@ -0,0 +1,2077 @@ +III The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: All right. + +We'll back up and start again +since I just turned on my + +microphone. + +I started with the observation +that for most of recorded + +history people thought +qualitatively, not + +quantitatively. + +They didn't know what +statistics were. + +They must have had some +intuitive sense, for example, + +that if you're old, you're +more likely to have bad + +hearing than if you're young. + +If you're old you're +more likely to die + +than if you're young. + +Things like that. + +But they were just anecdotes, +and they had no careful way to + +go from statements about +individuals to statements + +about populations +or expectations. + +This changed in about the middle +of the 17th century, + +changed fairly dramatically, +when an Englishman named John + +Graunt published something +called The Natural and + +Political Observations Made Upon +the Bills of Mortality. + +This was the first work in +recorded history that actually + +used statistics. + +And what he did is he looked +at the fairly comprehensive + +statistics of when people died +in the city of London. + +And from that, attempted to +produce a model that could be + +used to predict the spread +of the plague. + +And it turns out, he was +pretty good at it. + +And that just changed the way +people started to think. + +And since that time, people have +used statistics both to + +inform and, unfortunately, +to mislead. + +Some have willfully used +statistics to mislead, others + +have merely been incompetent. + +And that gets me to what I +want to talk about today, + +which is statistics. + +This is often attributed to Mark +Twain but, in fact, he + +copied it from Benjamin +Disraeli, who said, "There are + +three kinds of lies: lies, +damned lies, and statistics." + +And there is, unfortunately, +a lot of truth in that. + +More recently, in the '50s +Darrell Huff wrote a wonderful + +book, I recommend it, called +How to Lie with Statistics. + +Now here's a quote from the +book, "If you can't prove what + +you want to prove, demonstrate +something else and pretend + +that they're the same thing. + +In the daze that follows the +collision of statistics with + +the human mind, hardly anyone +will notice the difference." + +Alas, that seems to be true. + +So what I want to do today is +talk about a few ways in which + +one can be fooled into drawing +inappropriate conclusions from + +statistical data. + +Now I trust that you +will use this + +information only for good. + +And it will make you a better +consumer and purveyor of data + +rather than a better liar, +but that's up to you. + +All right. + +So let's start with the +first way out thing I + +want to talk about. + +And it's important to always +remember that no matter how + +good your statistics are, +statistical measures don't + +tell the whole story. + +We've seen examples of this +already earlier in the term. + +There are an enormous set of +statistics that can be + +extracted from a data set. + +And by carefully picking and +choosing among them, it's + +possible to convey almost any +impression you want about the + +same data set. + +The best antidote, of course, is +to look at the data itself. + +In 1973, the statistician John +Anscombe published a paper + +with this set of data. + +Four different examples where +he gave values for x and y, + +nothing very sophisticated. + +The interesting thing is that +in many ways, the statistics + +for these four data sets +are very similar. + +They have the same mean, the +same median, the same variance + +for x and y both, the same +correlation between x and y. + +And even if we use linear +regression to get a fit, we + +get very similar things. + +So let's look at it. + +I actually wrote some +code to do that. + +So this just reads in the data +set that we just had up, and + +then plots some things +with it. + +And so let's look at it. + +So what you can see is, you have +these in your hand out, + +we have four graphs, +four plots. + +And I won't show you +them all because + +they're all are identical. + +What they all give me is a mean +of 7.5 and a whole bunch + +of things, same to 17 decimal +places or so, the same median + +and the same linear fit, +y equals 0.5x plus 3. + +So I might write a paper in +which I would tell you that + +well, from a statistical +sense, these data + +sets are all the same. + +Every statistical result I +ran said these things are + +indistinguishable. + +Well, is it true that +these data sets are + +indistinguishable? + +Well, one way to look at it is +to actually plot the points. + +So we can run it with true, +which says in addition to + +plotting the data, put points +on them in addition to + +plotting the statistics. + +And now we see something +fairly dramatic. + +So for example, figure (2) and +figure (1) don't look a lot + +like each other, when we +actually look at the data. + +Figure (3) looks quite different +and figure (4) is + +remarkably different. + +Compare figure (4) to, +say, figure (1). + +Again, these are all +in your hand out. + +So the moral is pretty simple +here, and it's one we looked + +at before, which is, don't +ever ignore the data. + +Don't just look at statistics +about the data, try and find a + +way to look at the +data itself. + +Of course, it's easy enough to +look at the data, but how do + +you look at it? + +And the next thing to +remember is that + +pictures can be deceiving. + +There can be no doubt about the +utility of graphics for + +quickly conveying information. + +However, when used carelessly or +maliciously, a plot can be + +highly misleading. + +So let's look-- go back to the +PowerPoint, and look at this + +plot of housing prices +in the Midwest. + +So we've got a plot here, and +we've got years 2006, 2007 and + +then in 2008 and 9, +we have quarters. + +You may remember that there was +an event in the housing + +market in 2008 precipitating the +global financial crisis. + +And if we look at this, what +impression do we get about + +housing prices in the mid +west during this period? + +Well I would get the impression +that they are + +remarkably stable. + +You publish this and you say, +OK, look they really haven't + +changed very much. + +Maybe they've gone down +a little, but + +nothing very serious. + +If we compare that to this plot, +which is exactly the + +same data, and now I ask +you about housing + +prices in the Midwest. + +Well, what you might +tell me is it's-- + +they're remarkably unstable. + +And in fact, there was +clearly some sort of + +horrible event here. + +Exactly the same data, two +plots both of which are + +truthful, but which give a +radically different impression + +about what happened. + +The chart on the right +was designed-- + +on the right in your handout-- + +was designed to show that they +were highly unstable. + +So what's the difference? + +What trick did I use to produce +these two plots? + +Yeah? + +AUDIENCE: In the more +stable one, you used + +the logarithmic scale. + +And then here only has +selected numbers so-- + +PROFESSOR: So that +was certainly one + +trick that I performed. + +That in the first chart, +I plotted the y-axis + +logarithmically, which always +make things look like they are + +changing less than if +I plot it linearly. + +And in this chart, I +used a linear plot. + +Go ahead. + +AUDIENCE: You see a much +narrower scale + +on the second plot. + +So that the magnitude of the +difference is much less + +compared to the magnitude of the +whole graph of the scale. + +PROFESSOR: So that's the other +thing I did is, if you look at + +it, I sort of cheated. + +I had full years here and +then I went to quarters. + +So in part of my chart, the +resolution on the x is pretty + +wide is a whole year, and then +part of it's on a quarter. + +And, not surprisingly, since +we know that housing prices + +change seasonally, they're +different in the spring than + +in the winter, once I start +plotting quarters, even if + +there had not been a crash, it +would have looked much less + +stable in the out years, +because I changed the + +resolution on the x-axis. + +I didn't lie. + +You can tell reading the +legend that I did that. + +But I sure could have +fooled a lot of + +people with these charts. + +Here's another nice example +of statistics. + +So this plots-- + +this is from a paper by two +professors, I think from Yale, + +shows what you can do if you're +in the Ivy league, that + +plots initials against GPA +for students at Yale. + +And so you can see that if your +first name starts with + +the letter A, I think it was +first initials, your GPA is + +considerably higher than if it +starts with C or D. And if + +your parents weren't nice enough +to give you an A name, + +you could hope they at least +gave you a B name. + +And you certainly don't +want them to give + +you a C or a D name. + +So if you're Charlene or David +you could have a real problem. + +I have to say my first child +was named David. + +His GPA might have been +somewhere in there. + +All right -- + +clearly it matters. + +Well, what tricks did +I perform here? + +AUDIENCE: There is very +little disparity in x. + +You are going from 3.32 to-- + +PROFESSOR: Right. + +So what I did here is I made the +range on the y-axis very + +small, ranging from 3.32 to +3.38, not a big difference. + +However, because that's the +whole thing, it looks like + +it's a big difference. + +You will often see this when +you, say, look at things in + +newspapers where, in fact, +someone has manipulated one of + +the axes to make things +look big or small. + +If I had ranged this from a GPA +of 0.0 to a GPA of 4.0, + +the highest GPA at Yale, +this difference would + +have looked very tiny. + +But I didn't -- + +actually it wasn't I. I actually +copied this from + +their paper. + +This was the way they presented +it in their paper. + +Because they were trying to +argue in the paper that your + +name had a big influence +on your life. + +And they used many statistics +including your grades. + +And so they actually formatted +it kind of like this to try + +and give you this impression. + +Now later we'll see another +statistical sin they committed + +in this paper, which, basically, +was designed to + +show that in your name +was destiny. + +And they had many +other things. + +If you're a baseball player, and +your name starts with K, + +you're more likely +to strike out. + +Because K is the symbol for +strikeouts in a baseball score + +book, a lot of implausible +things. + +All right. + +Moving right along, probably +the most serious and common + +statistical error is +the one known as + +Garbage In Garbage Out. + +And it's so common that people +typically refer to it by its + +acronym GIGO -- + +Garbage In Garbage Out. + +A classic example of this +occurred and, we could look at + +more recent examples, +but I don't want to + +offend any of you. + +In 1840, United states census +showed that insanity among + +free blacks and mulattoes was +roughly 10 times more common + +than insanity among enslaved +blacks or mulattoes. + +And the conclusion from this +was obvious, I guess. + +US Senator, former Vice +President, and later, + +Secretary of State John C. +Calhoun concluded from the + +census and I quote, "The data +on sanity revealed In this + +census is unimpeachable. + +From it, our nation must +conclude that the abolition of + +slavery would be to the African, +a curse." Because + +after all, if you freed them +from slavery, they + +would all go insane. + +That's what the statistics +reported, he said. + +Now never mind it was soon clear +that in fact that census + +was riddled with errors. + +And John Quincy Adams, a former +Vice President and + +Massachusetts resident responded +to Calhoun and said, + +no that's a ridiculous +conclusion. + +The census is full of errors. + +Calhoun, being a very patient +person, explained to Adams the + +following, "There were so many +errors, that they balanced one + +another out, and led to the same +conclusion just as much + +as if they were all correct." +There were just enough errors + +that you could be OK. + +Well, what was he relying on? + +What should he have said if he +wanted to make this statement + +more mathematically precise? + +What he was basically implying +is that the measurement errors + +are unbiased and independent of +each other and, therefore, + +almost identically distributed +on either side of the mean. + +I see a typo, I might +as well fix it. + +Might as well make it big +enough to fix it. + +That's interesting. + +If he had made this much more +precise statement, then you + +could have had an meaningful +discussion-- + +assuming it was possible to have +a meaningful discussion + +with John Calhoun, which +is perhaps dubious-- + +about whether or not, in fact, +the errors are independent. + +Because if they're not, if, for +example, they represent + +bias in the people compiling the +data, then you cannot rely + +upon statistical methods +to say that they'll + +balance each other out. + +You remember way back in Gauss' +time, Gauss talked + +about this when he talked about +the normal distribution. + +And said, well, if we take +these astronomical + +measurements and we assume our +errors are independent and + +normally distributed, then we +can look at the mean and + +assume that that's close +to the truth. + +Well, those are important +assumptions which in this case + +turned out to be not correct. + +And, in fact, it was later shown +that the errors did not + +balance each other out nicely. + +And in fact, today you can say +that no statistical conclusion + +can be drawn from that. + +On the other hand recently, +the US National Research + +Council, perhaps the most +prestigious academic + +organization in the United +states, published a ranking of + +all universities +in the country. + +And it was later shown that it +was full of garbagy input. + +And they did extensive +statistical analysis and + +published it on data that turned +out to be just wrong. + +And it was very embarrassing. + +Now the good news is +MIT came out near + +the top of this analysis. + +And the bad news is we can't +conclude that it actually + +should have been near the top +because who knows about the + +quality of the data, but +kind of embarrassing. + +All right. + +Moving right along, another very +common way to lie with + +statistics is to exploit what's +called the cum hoc ergo + +propter hoc fallacy. + +So anyone here study Latin? + +Bunch of techy-- + +Oh OK. + +Well what does it mean? + +AUDIENCE: With this therefore, +because of this? + +PROFESSOR: Boy, your +Latin is good. + +Either that or you just +know statistics. + +But I have to say that was the +most fluent translation I've + +had it all the years I've +asked this question. + +I hit the relay man-- the relay +woman on the throw. + +All right. + +Yes, with this, therefore +because of this. + +I don't know why but +statisticians, like physicians + +and attorneys, like +to show off by + +phrasing things in Latin. + +So for example, it is a +statistical fact that college + +students, including MIT +students, who regularly attend + +lectures have higher GPAs than +students who attend lectures + +only sporadically. + +So that would tell us that those +of you in the room are + +likely to have a higher GPA than +the various students in + +6.00 who are not in this room. + +I hope it's true. + +Now if you're a professor who +gives these lectures, what you + +want to believe it's because the +lectures are so incredibly + +informative, that we make the +students who come much smarter + +and, therefore, they +do better. + +And so we'd like to +assume causality. + +Because I give beautiful +lectures and you choose to + +come, you will get a better +grade in 6.00. + +Well, yes, there's +a correlation. + +It's unquestionably true, but +causation is hard to jump to. + +For example, maybe it's the +point that students who bother + +to come to lecture also bother +to do the problem sets, and + +are just more conscientious. + +And whether they came to lecture +or not, the fact that + +they're more conscientious would +give them better GPAs. + +There's no way I know to +separate those two things, + +other than doing a controlled +experiment, right? + +Maybe kicking half of you out of +lecture every day and just + +see how it goes. + +But it's dangerous but again, +you can read things like the + +faculty newsletter, which will +talk about how important it is + +to come the lecture because +you'll do better. + +Because whoever wrote that +article for the faculty + +newsletter didn't understand +this-- + +this fallacy, or was just +thinking wishfully. + +Another nice example, one that +was in the news not too long + +ago, has to do with the flu. + +This was the cases of +flu in New York + +State in recent years. + +And you'll notice that there was +a peak in 2009, and that + +was the famous swine flu +epidemic, which I'm sure you + +all remember. + +Now, if you look at this +carefully, or even not too + +carefully, you'll notice a +correlation between when + +schools are in session and +when the flu occurs. + +That in fact, during those +months when schools are in + +session, there are more cases of +flu than in the months when + +school is not in session, high +schools, colleges, whatever. + +Quite a strong correlation, +in fact. + +This led many to conclude that +going to school is an + +important causative factor +in getting the flu. + +And so maybe you shouldn't +have come to the lectures + +because you would have just +gotten the flu by doing so. + +And in fact because of this, +you had many parents not + +sending their kids to school +during the swine flu epidemic. + +And in fact, you had many +schools closing in some + +communities because of the +swine flu epidemic. + +Well, let's think about it. + +Just as you could use this +correlation to conclude that + +going to school causes the swine +flu, you could have also + +used it to prove that the flu +causes you to go to school. + +Because more people are in +school when the flu season is + +at it's height. + +And therefore, it's the growth +of flu that causes people to + +go to school. + +That's an equally valid +statistical + +assumption from this data. + +Kind of a weird thing but +it's true, right? + +Just as we could conclude that +having a high GPA causes + +people to come to the lecture. + +You look at your GPA every +morning, and if it's high + +enough, you come to lecture, +otherwise, you don't. + +You could draw that conclusion +from the data as well. + +The issue here that you have to +think about is whether or + +not there is what's called a +lurking variable, some other + +variable that's related to the +other two, and maybe that's + +the causative one. + +So for example, a lurking +variable here is that the + +school season coincides with +or the non-school season, + +maybe I should say, coincides +with the summer. + +And in fact, if you study the +flu virus in a lab, you will + +discover that it survives longer +in cold weather than in + +hot and humid weather. + +When it's cold and dry, the flu +virus will survive for a + +longer time on a surface +than it will when + +it's warm and humid. + +And so in fact, maybe it's the +weather, not the presence of + +schools, that causes the flu +to be more virulent during + +certain times of the year. + +In fact, it's probably +likely true. + +So there is a lurking variable +that we have to consider, and + +maybe that's the causative +factor. + +Now, this can actually lead +to some really bad + +decisions in the world. + +I'm particularly interested in +issues related to health care + +and public health. + +In 2002, roughly 6 million +American women were taking + +hormone replacement therapy, in +the belief that this would + +substantially lower their risk +of cardiovascular disease. + +It was argued that women over a +certain age or of a certain + +age, if you took extra hormones, +they were less + +likely to have a heart attack. + +This belief was supported by +several published studies in + +highly reputable journals in +which they showed a strong + +correlation between being on +hormone replacement therapy + +and not having cardiovascular +disease. + +And this data had been around +a while and, as I said, by + +2002 in the US, roughly +6 million women + +were on this therapy. + +Later that year, the Journal +of the American Medical + +Society published an article +asserting that in fact being + +on this therapy increased +women's risk of + +cardiovascular disease. + +It made you more likely to +have a heart attack. + +Well, how could this +have happened? + +After the new study came out, +people went back and + +reanalyzed the old study and +discovered that the women in + +that study who'd been on hormone +replacement therapy + +were more likely than the other +women in the group to + +have also better diet and be on +a better exercise regimen. + +In fact, they were women who +were more health conscious. + +So there were the lurking +variables of diet and exercise + +and other things that were, in +fact, probably the causative + +factors in better health, not +the replacement therapy. + +But there was this lurking +variable that had not been + +discovered in the initial +analysis of the data. + +So what we saw is that taking +hormone replacement therapy + +and improved cardiac health were +coincident effects of a + +common cause, that is to say +being health conscious. + +Kind of a strange thing but +a true and sad story. + +All right. + +Moving right along, another +thing to be cautious of is + +non-response bias and +related problem of a + +non-representative sample. + +You'll probably recall that when +I first started talking + +about statistics and the use of +randomness, I said that all + +statistical techniques are based +upon the assumption that + +by sampling a subset of a +population, we can infer + +things about the population +as a whole. + +And that's true, typically, +because if random sampling is + +used, you can make assumptions +that the distribution of + +results from the random sample, +if it's large enough, + +will be the same as a +distribution of results from + +the whole population. + +And that's why we typically +want to sample randomly. + +And so for all the simulations +we looked at, we used random + +sampling to try and ensure that +a small number of samples + +would give us something +representative of the + +population. + +And then we use statistical +techniques to answer the + +question about how many random +samples we needed. + +But those techniques were only +valid if the samples were + +indeed random. + +Otherwise, you can analyze it +to your heart's content and + +any conclusions you've drawn are +likely to be fallacious. + +Unfortunately, many studies, +particularly in the social + +sciences, are based on +what is often called + +a convenience sampling. + +So for example, if you look +at psychological-- + +psychology journals, you'll find +that many psychological + +studies use populations of + +undergraduates for their studies. + +Why did they do this? + +Is it because they believe +that undergraduates are + +representative of the population +as a whole? + +No. + +It's because they're captive. + +They have to agree to +participate, right? + +It's a convenience if you happen +to be at a university + +to do your experiments +on undergraduates. + +And so they do that and then +they say, well, the + +undergraduates are just like +the population as a whole. + +You may have observed that at +least at this institution, the + +undergraduates are probably +not representative of the + +population as a whole. + +A well-known example of what you +can do with this occurred + +during World War II. + +Whenever an allied plane would +return from a bombing run over + +Germany, the plane would be +inspected to see where flak + +had hit it. + +So the planes would fly over +to drop bombs, the Germans + +would shoot flak at the planes +to try and knock + +them out the air. + +They'd come back to England, +they'd get inspected, they'd + +say, well the flak hit this part +of the plane more often + +than that part of the +plane on average. + +And so they would reinforce the +skin of those parts of the + +plane where they expected the +flak to hit, to try and make + +the plane less likely to be +damaged in future runs, or the + +planes in general. + +What's wrong with this? + +Yeah? + +AUDIENCE: They're not getting +the planes that dropped? + +PROFESSOR: Exactly. + +What they're not sampling is the +planes that never made it + +back from the bombing, ooh, that +never made it back from + +the bombing runs because they +weren't there to sample. + +And in fact maybe it's the case +that what they were doing + +was reinforcing those parts of +the planes where it didn't + +matter if you got hit by flak +because it wouldn't cause a + +plane to crash, and not +reinforcing those parts of the + +planes that were most +vulnerable to + +being damaged by flak. + +They did a convenient +sampling, they drew + +conclusions, and they probably +did exactly the wrong thing in + +what they chose to reinforce +in the airplanes. + +This particular error is called +non-response bias where + +you do some sort of survey, for +example, and some people + +don't respond and, therefore, +you ignore what + +they would have said. + +It's perhaps something we see +when we do the underground + +guide to Course 6. + +In fact I should point out +that it's now online. + +And it would be good if each of +you would go and rate this + +course, rate the lectures, +rate the TAs, et cetera. + +We actually do read them and it +makes a difference in how + +we teach the course in +subsequent terms. + +But there's clearly a bias. + +You know, maybe only the +people who really feel + +strongly about the course, +either positively or + +negatively, bother to +fill out the survey. + +And we draw the conclusions +that there's a bimodal + +distribution, and nobody thinks +it's kind of mediocre, + +because they don't bother +responding. + +Or maybe only the people who +hate the course respond, and + +we think everybody +hates the course. + +Who knows. + +It's a big problem. + +We see it, it's a big problem +today with telephone polls, + +where you get more convenient +sampling and + +non-representative samples, +where a lot of polls are done + +using telephones. + +By law, these pollsters cannot +call cell phones, so they only + +call land lines. + +How many of you have +a land line? + +Let the record show, nobody. + +How many of your parents +have a land line? + +Let the record show, pretty +much everybody. + +Well, that means your parents +are more likely to get sampled + +than you when there's a poll +of, say, who should be + +nominated for president. + +And so any of these polls +that are based on + +telephones will be biased. + +And, unfortunately, their poll +may just say, a telephone + +sample, and people may +not realize the + +implication of that. + +That whole part of the +population is under sampled. + +There are lots of examples +of this. + +All right. + +Moving along, another problem +we often see is data + +enhancement. + +It's easy to read much more +into data than it actually + +implies, especially when +viewed out of context. + +So on April 29, 2009, CNN +reported that quote, "Mexican + +health officials suspect that +the swine flu outbreak has + +caused more than 159 deaths and +roughly 2,500 illnesses." + +It was pretty scary stuff at the +time, and people got all + +worried about the swine flu. + +On the other hand, how many +deaths a year do you think are + +attributable to the +conventional + +seasonal flu in the US? + +Anyone want to hazard a guess? + +36,000. + +So 36,000 people a year, on +average, will die from the + +seasonal flu, which sort of puts +in prospective that 159 + +deaths from the swine flu +maybe shouldn't be so + +terrifying. + +But again, people typically did +not report both of those. + +Another great statistic, and +accurate, is that most auto + +accidents happen within +10 miles of home. + +I'm sure many of you +have heard that. + +So what does that mean? + +Almost nothing. + +Most driving is done +with 10 miles-- + +within 10 miles of home. + +And besides that, what does +home mean in this context? + +What home means is +the registration + +address of the car. + +So if I were to choose to +register my car in Alaska, + +does that mean I'm less likely +to have an accident driving + +around MIT? + +I don't think so. + +Again, it's a kind +of a meaningless. + +Another aspect of this +is people often + +extrapolate from data. + +So we can look at an example +of internet usage. + +This is kind of a fun one too. + +So what I've plotted here is +the internet usage in the + +United states as a percentage +of population. + +And I plotted of this from-- + +starting at 1994. + +And the green line, or actually, +the blue line there + +are the points and the green +line is a linear fit. + +If you looked at my code, you'd +see I was using polyfit + +with a 1 to get a line to fit, +and you can see it's a pretty + +darn good fit. + +So people actually looked at +these things and used this to + +extrapolate internet usage +going forward. + +So we can do that. + +Now, we'll run the same +code with the + +extrapolation turned on. + +And so figure (1) is the same +figure (1) as before, same + +data, same fit. + +And here's figure (2). + +And you'll notice that as of +last year about 115% of the US + +population was using the +internet, probably not true. + +It may be possible in sports +to give 110%, but in + +statistics it's not. + +Again, you see this all the +time when people are doing + +these projections. + +They'll say, fit some data, +they extrapolate into the + +future without understanding +why maybe that isn't a good + +thing to do. + +We saw that by when we were +modeling springs, right? + +We could accurately project +linearly until we exceeded the + +constant of elasticity at which +point our linear model + +was totally broken. + +So you always need to have some +reason other than just + +fitting the data to believe that +what you're doing makes + +actual sense. + +All right. + +The final one I want to talk +about is what is typically + +called in the literature the +Texas sharpshooter fallacy. + +And this is a little bit tricky + +to understand sometimes. + +Actually, is there anyone +here from Texas? + +Oh good, so no one will +be offended by this. + +Well imagine that you're driving +down some country road + +in Texas and that +you see a barn. + +And that barn has six targets +painted on it, and in the dead + +center of each target, you +find a bullet hole. + +So you're driving, your pretty +impressed, and you stop. + +And you see the owner of the +barn and you say, you must be + +a damn good shot. + +And he says, absolutely, +I never miss. + +At which point the farmer's +wife walks out and says, + +that's right there ain't a man +in the state of Texas who is + +more accurate with +a paint gun. + +What did he do? + +He shot six bullets into +the barn, and he + +was a terrible shot. + +They were all over the place. + +Then he went and painted a +target around each of them. + +And it looked like he +was a great shot. + +Now you might think that, well +that's silly, no one would do + +that in practice. + +But in fact, it happens all +of the time in practice. + +A classic of this genre appeared +in the magazine New + +Scientist, in 2001. + +And it reported that a research +team led by John + +Eagles of the Royal Cornhill +Hospital in Aberdeen, had + +discovered that and I quote, +"Anorexic women are most + +likely to have been born in +the spring or early summer + +between March and June. + +In fact, there were +more than-- + +there were more than 13%-- + +there were 13% more anorexics +born on average in those + +months, and 30% more anorexics, +on average, in + +June." + +Now, let's look at this +worrisome statistic. + +Are any of you women +here born in June? + +All right. + +Well, I won't ask about +your health history. + +But maybe you should be +worried, or maybe not. + +So let's look at how they +did this study. + +You may wonder why so many of +these studies are all studies + +about women's health. + +And then, perhaps, because +they're all + +done by male doctors. + +Anyway, the team studied 446 +women who had been diagnosed + +as anorexic. + +So if you divide that by 12 +what you've discovered is + +that, on average, there should +have been 37 women born in + +each of those months, +of the 446. + +And in fact, in June, there were +48 anorexic women born. + +So they said, well, how likely +is this to have occurred + +simply by chance? + +Well as I am want to do in +such occasions, I checked + +their analysis, and I +wrote a little piece + +of code to do that. + +So trying to figure out what's +the probability of 48 women + +being born in June, I ran +a simulation in which I + +simulated 446 births and chose +a month at random, and looked + +at the probability. + +And let's see what it +was when we run it. + +Oops, well we didn't +want these graphs. + +The probability of at least 48 +births in June was 0.042. + +So in fact, pretty low. + +You might say, well, what's +the odds of this + +happening by accident? + +Pretty small. + +Therefore, maybe we are really +on to something. + +Maybe it has to do with the +conditions of the birth and + +the weather or who knows what. + +Well, what's wrong with +this analysis? + +Well, one way to look at it is +this analysis would have been + +perfectly valid if the +researchers had started with a + +hypothesis that there are more +babies born in June than in + +any other month-- more future +anorexics born in June than in + +any other month, and then run +this experiment to test it, + +and validated it. + +So if they had started with the +hypothesis, and then from + +the hypothesis conducted what's +called a prospective + +study then they would have, +perhaps, valid reason to + +believe that the study supports +the hypothesis. + +But that's not what they did. + +Instead what they did is they +looked at the data and then + +chose a hypothesis that matched +the data, the Texas + +sharpshooter fallacy. + +Given that that was the +experiment they performed, the + +right question to ask is not +what is the probability that + +you had 48 future anorexics born +in June, but what was the + +probability that you have 48 +future anorexics born in at + +least one of the 12 months? + +Because that's what they were +really doing, right? + +So therefore, we should really +have run this simulation. + +Similar to the previous one, +again, these are in your hand + +out, but is there at least +one month in which + +there were 48 births? + +And if we run that we'll see +that the probability is over + +40%, not so impressive as 4%. + +So in fact, we see that we +probably shouldn't draw any + +conclusion. + +The probability of this +happening by pure accident is + +almost 50%. + +So why should we believe that +it's somehow meaningful. + +Again, an example of the Texas +sharpshooter fallacy that + +appeared in the literature and +a lot of people fell for it. + +And if we had more time, I +would give you many more + +examples, but we don't. + +I'll see you on Thursday, +on Tuesday, rather. + +Two more lectures to go. + +On Tuesday, I'm going to go over +some code that I'll be + +asking you to look +at in preparation + +for the final exam. + +And then on Thursday, we'll +wrap things up. \ No newline at end of file diff --git a/K2Tlj27nkjs.txt b/K2Tlj27nkjs.txt new file mode 100644 index 0000000000000000000000000000000000000000..d93961cb09cb32528fb8ff683099f16f4b28faad --- /dev/null +++ b/K2Tlj27nkjs.txt @@ -0,0 +1,899 @@ +align:start position:0% + +in this segment we start a new topic we + + align:start position:0% +in this segment we start a new topic we + + + align:start position:0% +in this segment we start a new topic we +will talk about the covariance of two + + align:start position:0% +will talk about the covariance of two + + + align:start position:0% +will talk about the covariance of two +random variables which gives us useful + + align:start position:0% +random variables which gives us useful + + + align:start position:0% +random variables which gives us useful +information about the dependencies + + align:start position:0% +information about the dependencies + + + align:start position:0% +information about the dependencies +between these two random variables let + + align:start position:0% +between these two random variables let + + + align:start position:0% +between these two random variables let +us motivate the concept by looking first + + align:start position:0% +us motivate the concept by looking first + + + align:start position:0% +us motivate the concept by looking first +the special case suppose that x and y + + align:start position:0% +the special case suppose that x and y + + + align:start position:0% +the special case suppose that x and y +have zero means and that they are + + align:start position:0% +have zero means and that they are + + + align:start position:0% +have zero means and that they are +discrete random variables if x and y are + + align:start position:0% +discrete random variables if x and y are + + + align:start position:0% +discrete random variables if x and y are +independent then the expectation of the + + align:start position:0% +independent then the expectation of the + + + align:start position:0% +independent then the expectation of the +product is the product of the + + align:start position:0% +product is the product of the + + + align:start position:0% +product is the product of the +expectations and since we have assumed + + align:start position:0% +expectations and since we have assumed + + + align:start position:0% +expectations and since we have assumed +zero means this is going to be equal to + + align:start position:0% +zero means this is going to be equal to + + + align:start position:0% +zero means this is going to be equal to +zero but suppose instead that the joint + + align:start position:0% +zero but suppose instead that the joint + + + align:start position:0% +zero but suppose instead that the joint +PMF of the x and y is of the following + + align:start position:0% +PMF of the x and y is of the following + + + align:start position:0% +PMF of the x and y is of the following +kind each point in this diagram is + + align:start position:0% +kind each point in this diagram is + + + align:start position:0% +kind each point in this diagram is +equally likely so we have here a + + align:start position:0% +equally likely so we have here a + + + align:start position:0% +equally likely so we have here a +discrete uniform distribution on the + + align:start position:0% +discrete uniform distribution on the + + + align:start position:0% +discrete uniform distribution on the +discrete set which consists of the + + align:start position:0% +discrete set which consists of the + + + align:start position:0% +discrete set which consists of the +points shown in this diagram what we + + align:start position:0% +points shown in this diagram what we + + + align:start position:0% +points shown in this diagram what we +have in this particular example is that + + align:start position:0% +have in this particular example is that + + + align:start position:0% +have in this particular example is that +that most outcomes positive values of X + + align:start position:0% +that most outcomes positive values of X + + + align:start position:0% +that most outcomes positive values of X +tend to go together with positive values + + align:start position:0% +tend to go together with positive values + + + align:start position:0% +tend to go together with positive values +of Y and negative values of X tend to go + + align:start position:0% +of Y and negative values of X tend to go + + + align:start position:0% +of Y and negative values of X tend to go +together with negative values of Y so + + align:start position:0% +together with negative values of Y so + + + align:start position:0% +together with negative values of Y so +most of the time we have outcomes in + + align:start position:0% +most of the time we have outcomes in + + + align:start position:0% +most of the time we have outcomes in +this quadrant in which x times y is + + align:start position:0% +this quadrant in which x times y is + + + align:start position:0% +this quadrant in which x times y is +positive or in this quadrant where x + + align:start position:0% +positive or in this quadrant where x + + + align:start position:0% +positive or in this quadrant where x +times y is again positive but some of + + align:start position:0% +times y is again positive but some of + + + align:start position:0% +times y is again positive but some of +the time we fall in this quadrant when + + align:start position:0% +the time we fall in this quadrant when + + + align:start position:0% +the time we fall in this quadrant when +an x times y is negative or in this + + align:start position:0% +an x times y is negative or in this + + + align:start position:0% +an x times y is negative or in this +quadrant where x times y is negative + + align:start position:0% +quadrant where x times y is negative + + + align:start position:0% +quadrant where x times y is negative +since we have many more points here and + + align:start position:0% +since we have many more points here and + + + align:start position:0% +since we have many more points here and +here + + align:start position:0% +here + + + align:start position:0% +here +on the average the value of x times y is + + align:start position:0% +on the average the value of x times y is + + + align:start position:0% +on the average the value of x times y is +going to be positive on the other hand + + align:start position:0% +going to be positive on the other hand + + + align:start position:0% +going to be positive on the other hand +if the diagram takes this form then most + + align:start position:0% +if the diagram takes this form then most + + + align:start position:0% +if the diagram takes this form then most +of the time the pair XY lies in this + + align:start position:0% +of the time the pair XY lies in this + + + align:start position:0% +of the time the pair XY lies in this +quadrant or in that quadrant where the + + align:start position:0% +quadrant or in that quadrant where the + + + align:start position:0% +quadrant or in that quadrant where the +product of x times y is negative so the + + align:start position:0% +product of x times y is negative so the + + + align:start position:0% +product of x times y is negative so the +random variables x and y typically have + + align:start position:0% +random variables x and y typically have + + + align:start position:0% +random variables x and y typically have +opposite signs and on the average the + + align:start position:0% +opposite signs and on the average the + + + align:start position:0% +opposite signs and on the average the +expected value of x times y is going to + + align:start position:0% +expected value of x times y is going to + + + align:start position:0% +expected value of x times y is going to +be negative so here we have a positive + + align:start position:0% +be negative so here we have a positive + + + align:start position:0% +be negative so here we have a positive +expectation here we have a negative + + align:start position:0% +expectation here we have a negative + + + align:start position:0% +expectation here we have a negative +expectation of x times y this quantity + + align:start position:0% +expectation of x times y this quantity + + + align:start position:0% +expectation of x times y this quantity +the expected value of x times y tells us + + align:start position:0% +the expected value of x times y tells us + + + align:start position:0% +the expected value of x times y tells us +whether x and y tend to move in the same + + align:start position:0% +whether x and y tend to move in the same + + + align:start position:0% +whether x and y tend to move in the same +or in opposite directions and this + + align:start position:0% +or in opposite directions and this + + + align:start position:0% +or in opposite directions and this +quantity is what we call the covariance + + align:start position:0% +quantity is what we call the covariance + + + align:start position:0% +quantity is what we call the covariance +in the zero mean case let us now + + align:start position:0% +in the zero mean case let us now + + + align:start position:0% +in the zero mean case let us now +generalize the random variables do not + + align:start position:0% +generalize the random variables do not + + + align:start position:0% +generalize the random variables do not +have to be discrete + + align:start position:0% +have to be discrete + + + align:start position:0% +have to be discrete +this quantity is well defined for any + + align:start position:0% +this quantity is well defined for any + + + align:start position:0% +this quantity is well defined for any +kind of random variables and if we have + + align:start position:0% +kind of random variables and if we have + + + align:start position:0% +kind of random variables and if we have +non zero means the covariance is defined + + align:start position:0% +non zero means the covariance is defined + + + align:start position:0% +non zero means the covariance is defined +by this expression what we have here is + + align:start position:0% +by this expression what we have here is + + + align:start position:0% +by this expression what we have here is +that we look at the deviation of X from + + align:start position:0% +that we look at the deviation of X from + + + align:start position:0% +that we look at the deviation of X from +its mean value and the deviation of Y + + align:start position:0% +its mean value and the deviation of Y + + + align:start position:0% +its mean value and the deviation of Y +from its mean value and we are asking + + align:start position:0% +from its mean value and we are asking + + + align:start position:0% +from its mean value and we are asking +whether these two deviations tend to + + align:start position:0% +whether these two deviations tend to + + + align:start position:0% +whether these two deviations tend to +have the same sign or not whether they + + align:start position:0% +have the same sign or not whether they + + + align:start position:0% +have the same sign or not whether they +move in the same direction or not if the + + align:start position:0% +move in the same direction or not if the + + + align:start position:0% +move in the same direction or not if the +covariance is positive what it tells us + + align:start position:0% +covariance is positive what it tells us + + + align:start position:0% +covariance is positive what it tells us +is that whenever this quantity is + + align:start position:0% +is that whenever this quantity is + + + align:start position:0% +is that whenever this quantity is +positive so that X is above its mean + + align:start position:0% +positive so that X is above its mean + + + align:start position:0% +positive so that X is above its mean +then typically or usually the deviation + + align:start position:0% +then typically or usually the deviation + + + align:start position:0% +then typically or usually the deviation +of Y from its mean will also tend to be + + align:start position:0% +of Y from its mean will also tend to be + + + align:start position:0% +of Y from its mean will also tend to be +positive to summarize the covariance in + + align:start position:0% +positive to summarize the covariance in + + + align:start position:0% +positive to summarize the covariance in +general tells us whether two random + + align:start position:0% +general tells us whether two random + + + align:start position:0% +general tells us whether two random +variables tend to move together both + + align:start position:0% +variables tend to move together both + + + align:start position:0% +variables tend to move together both +being high or both being low in sum + + align:start position:0% +being high or both being low in sum + + + align:start position:0% +being high or both being low in sum +average or typical sense now if the two + + align:start position:0% +average or typical sense now if the two + + + align:start position:0% +average or typical sense now if the two +random variables are independent we + + align:start position:0% +random variables are independent we + + + align:start position:0% +random variables are independent we +already saw that in the zero mean case + + align:start position:0% +already saw that in the zero mean case + + + align:start position:0% +already saw that in the zero mean case +this quantity the covariance is going to + + align:start position:0% +this quantity the covariance is going to + + + align:start position:0% +this quantity the covariance is going to +be zero how about the case where we have + + align:start position:0% +be zero how about the case where we have + + + align:start position:0% +be zero how about the case where we have +nonzero means well if we have + + align:start position:0% +nonzero means well if we have + + + align:start position:0% +nonzero means well if we have +independence then we have the expected + + align:start position:0% +independence then we have the expected + + + align:start position:0% +independence then we have the expected +value of the product of two random + + align:start position:0% +value of the product of two random + + + align:start position:0% +value of the product of two random +variables x and y are independent so X + + align:start position:0% +variables x and y are independent so X + + + align:start position:0% +variables x and y are independent so X +minus the expected value which is a + + align:start position:0% +minus the expected value which is a + + + align:start position:0% +minus the expected value which is a +constant is going to be independent from + + align:start position:0% +constant is going to be independent from + + + align:start position:0% +constant is going to be independent from +Y minus its expected value and so the + + align:start position:0% +Y minus its expected value and so the + + + align:start position:0% +Y minus its expected value and so the +covariance is going to be the product of + + align:start position:0% +covariance is going to be the product of + + + align:start position:0% +covariance is going to be the product of +two expectations + + align:start position:0% + + + + align:start position:0% + +but the expected value of X minus this + + align:start position:0% +but the expected value of X minus this + + + align:start position:0% +but the expected value of X minus this +constant is zero and the same is true + + align:start position:0% +constant is zero and the same is true + + + align:start position:0% +constant is zero and the same is true +for this term as well so the covariance + + align:start position:0% +for this term as well so the covariance + + + align:start position:0% +for this term as well so the covariance +in this case is going to be equal to + + align:start position:0% +in this case is going to be equal to + + + align:start position:0% +in this case is going to be equal to +zero so in the independent case we have + + align:start position:0% +zero so in the independent case we have + + + align:start position:0% +zero so in the independent case we have +zero covariances on the other hand the + + align:start position:0% +zero covariances on the other hand the + + + align:start position:0% +zero covariances on the other hand the +converse is not true there are examples + + align:start position:0% +converse is not true there are examples + + + align:start position:0% +converse is not true there are examples +in which we have dependence but zero + + align:start position:0% +in which we have dependence but zero + + + align:start position:0% +in which we have dependence but zero +covariance here is one example in this + + align:start position:0% +covariance here is one example in this + + + align:start position:0% +covariance here is one example in this +example there are four possible outcomes + + align:start position:0% +example there are four possible outcomes + + + align:start position:0% +example there are four possible outcomes +at at any particular outcome either X or + + align:start position:0% +at at any particular outcome either X or + + + align:start position:0% +at at any particular outcome either X or +Y is going to be zero so in this example + + align:start position:0% +Y is going to be zero so in this example + + + align:start position:0% +Y is going to be zero so in this example +the random variable x times y is + + align:start position:0% +the random variable x times y is + + + align:start position:0% +the random variable x times y is +identically equal to 0 the mean of X is + + align:start position:0% +identically equal to 0 the mean of X is + + + align:start position:0% +identically equal to 0 the mean of X is +also 0 the mean of Y is also 0 by + + align:start position:0% +also 0 the mean of Y is also 0 by + + + align:start position:0% +also 0 the mean of Y is also 0 by +symmetry so the covariance is the + + align:start position:0% +symmetry so the covariance is the + + + align:start position:0% +symmetry so the covariance is the +expected value of this quantity and so + + align:start position:0% +expected value of this quantity and so + + + align:start position:0% +expected value of this quantity and so +the covariance in this example is equal + + align:start position:0% +the covariance in this example is equal + + + align:start position:0% +the covariance in this example is equal +to 0 on the other hand the two random + + align:start position:0% +to 0 on the other hand the two random + + + align:start position:0% +to 0 on the other hand the two random +variables x and y are dependent if I + + align:start position:0% +variables x and y are dependent if I + + + align:start position:0% +variables x and y are dependent if I +tell you that X is equal to 1 then you + + align:start position:0% +tell you that X is equal to 1 then you + + + align:start position:0% +tell you that X is equal to 1 then you +know that this outcome has occurred and + + align:start position:0% +know that this outcome has occurred and + + + align:start position:0% +know that this outcome has occurred and +in that case you are certain that Y is + + align:start position:0% +in that case you are certain that Y is + + + align:start position:0% +in that case you are certain that Y is +equal to 0 so knowing the value of X + + align:start position:0% +equal to 0 so knowing the value of X + + + align:start position:0% +equal to 0 so knowing the value of X +tells you a lot about the value of Y and + + align:start position:0% +tells you a lot about the value of Y and + + + align:start position:0% +tells you a lot about the value of Y and +therefore we have dependence between + + align:start position:0% +therefore we have dependence between + + + align:start position:0% +therefore we have dependence between +these two random variables \ No newline at end of file diff --git a/MniYgsZSp30.txt b/MniYgsZSp30.txt new file mode 100644 index 0000000000000000000000000000000000000000..b2dc41267014ab0a50776ba7bf1eaea21a4b31f4 --- /dev/null +++ b/MniYgsZSp30.txt @@ -0,0 +1,3849 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: OK. + +Well hello, everyone. + +And welcome back to +Computational Systems Biology. + +I am David Gifford and I +am delighted to be back + +with you today. + +We're going to talk, +today, about understanding + +transcription. + +Specifically, how we're going +to understand transcription + +is a technique called RNA-seq. + +And RNA-seq is a methodology +for characterizing RNA molecules + +through next +generation sequencing. + +And we'll talk, first, +about RNA-seq principles. + +We'll then talk +about how to take + +the data we learn from RNA-seq +and analyze it using tools + +for characterizing +differential gene + +expression and principal +component analysis. + +And finally, we'll talk about +single cell RNA-seq, which + +is a very important and growing +area of scientific inquiry. + +But first, let's +talk about RNA-seq. + +How many people have +heard of RNA-seq before? + +Fantastic. + +How many people +have done it before? + +Some? + +Great. + +So RNA-seq is fairly +simple in concept. + +What we're going to +do is we're going + +to isolate RNA species from +a cell or collection of cells + +in the desired condition. + +And note that we can choose +which kind of RNA molecules + +to isolate. + +We can isolate molecules +before any selection, which + +would include molecules that +are precursor RNAs that have not + +been spliced yet, +including non-coding RNAs. + +As you probably know, the +study of non-coding RNAs + +is extraordinarily important. + +There are over 3,300 +so-called long non-coding RNAs + +that have been +characterized so far. + +Those are non-coding +RNAs over 200 bases long. + +We'll be talking about +those later on, when + +we talk about chromatin +function in the genome. + +And of course, there are +the precursor messenger RNAs + +that are spliced, turned into +messenger RNAs that are then + +translated into protein. + +And the specifics of +the RNA-seq protocol + +will give you various +of these species + +depending upon what kinds of +purification methodologies + +you use. + +But as you're aware, +there are many isoforms + +that are possible in +most mammalian genes. + +This is a short summary, +produced by the Burge + +Laboratory, of different +kinds of splicing + +events that can occur. + +And the splicing +events are often + +regulated by +cis-regulatory sequences + +that live in the introns. + +And these introns contain +recognition sequences + +for splicing factors where +the splicing factors can + +be conditionally expressed. + +And so you get +different combinations + +of these exons +being glued together + +to produce variant +forms of proteins. + +So we have to be +mindful of the idea + +that the RNA +molecules that we're + +going to be +observing, typically, + +are going to be +reverse transcribed. + +So we'll see entire +transcripts that came, perhaps, + +from distinct exonic +locations in the genome. + +And the essential +idea of RNA-seq + +is that we take the RNA +molecules we care about-- + +in this case, we're +going to purify + +the ones that have poly-A tails. + +We will take those molecules. + +We'll reverse transcribe them. + +We'll sequence fragments +of them and then + +map them to the genome. + +Now if you don't purify +for poly-A tails, + +you get a lot of things +mapping to the genome that + +are intronic. + +And so you get a +lot of data that + +is very difficult to analyze. + +So typically, +people, when they're + +looking for gene +expression data, + +will do poly-A purification. + +And when you do this-- when you +sequence the result of doing + +the reverse transcription +of these RNA molecules-- + +and you map the results to +the genome, what you find + +is data that looks like this. + +This is the SOX2 gene. + +This is typical expression data. + +You can see all of the +individual reads mapping + +to the genome, the blue +in the plus strand, + +the pink on the minus strand. + +And our job is to take data +like this and to analyze it. + +Now we can take +these data and we + +can summarize them +in various formats. + +One way is to simply +count the number of times + +that we see a read +at a particular base, + +like here, for the SMUG1 gene. + +And here you see +something else going on, + +which is that we have +reads from-- the sequencing + +experiments have been +polyadenylated and purified. + +So we're only seeing +the reads that + +occur over the exonic +sequences, more or less. + +There are a few intronic +reads there, scattered about. + +The other thing that we see, +which is very important, + +is that we see reads that +are split across exons. + +Because the splicing +event has occurred, + +the RNA molecule is +a contiguous sequence + +of a collection of exons. + +And sometimes you'll +get a read that + +spans an exon-exon boundary. + +And when we get +this, you can see, + +in the bottom part of the +slide that I'm showing you, + +these reads can map +across the exons. + +Typically, in order to +get good performance out + +of something like +this, we want to use + +reads that are about +100 bases long. + +And we'll use a mapper +that is capable of mapping + +both ends of a read to +account for split reads + +for these exon crossing events. + +So that gives you an idea of +the kinds of data that we have. + +And part of the +challenge now is looking + +at how we can determine which +particular isoforms of a gene + +are being expressed by +evaluating these data. + +So there are two principal +ways of going about this. + +One way is we simply +take our read data, + +and we use the ideas +that we talked about + +in genome assembly, and +we assemble the reads + +into transcripts. + +That's typically done de novo. + +There are reference +guided assemblers. + +It has the benefit that you +don't need a reference genome. + +So sometimes, when you're +working with an organism that + +does not have a well +characterized reference genome, + +you will de novo +assemble the transcripts + +from an RNA-seq experiment. + +But it also has problems +with correctness, + +as we saw when we +talked about assembly. + +The other approach, which +is more typically used, + +is to map reads, or aligned the +reads, to a reference genome + +and identify the +different isoforms that + +are being expressed +using constraints. + +And ultimately, the goals +is to identify the isoforms + +and quantitate them so we can +do further downstream analysis. + +And you'll hear about +two different metrics, + +sometimes, in the +literature, for expression. + +One is the number of +reads per kilobase + +of transcript per million reads. + +So you might have, for +example, an RPKM metric + +of 1,000, which means that one +out of every thousandth read + +is mapping to a particular gene. + +So it gives you a metric +that's adjusted for the fact + +that longer genes will +produce more reads. + +An alternative +metric is fragments + +per kilobase per million. + +And that's sometimes +used when we're + +talking about paired end data. + +And you're considering +that you're + +sequencing both +ends of a fragment. + +So here we're talking +about how many fragments + +we see for a particular +gene per 1,000 + +bases of the gene per +million fragments. + +OK. + +So the essential idea, +then, is to take the reads + +that we have-- the basket of +reads-- align it to the genome, + +both to exons and +to exon crossings, + +and to determine, for a given +gene, what isoforms we have + +and how they're being expressed. + +So from here on in, +I'm going to assume + +that we're talking about +a gene and its isoforms. + +And that's OK. + +Because typically, we can +map reads uniquely to a gene. + +And there are +details, of course, + +when you have genes +there are paralogs that + +have identical sequences across +the genome where this becomes + +more difficult. + +So if we consider +this, once again, + +we're going to take +our reads, we're + +going to map them to +the genome, and we're + +going to look for all +possible pairings of exons. + +What we would like +to do is to enumerate + +all of the possible +isoforms that are possible + +given the data that we have. + +And we can use junction crossing +reads and other methodologies + +to enumerate all the +possible isoforms. + +But what we're +going to assume is + +that we've enumerated +all the isoforms. + +And we're going to +number them 1 through n. + +So we have isoform 1, isoform +2, isoform 3 for a given gene. + +And what we want to +compute for each isoform is + +its relative contribution +to the read population + +we're seeing that +maps to that gene. + +So in order to do +that, what we could do + +is use some constraints. + +So if I show you +this picture, which + +suggests that we have +possible splice events here + +for the event C in the +middle, if I told you + +that A, C, and E were very +highly covered by reeds, + +you might think that +A, C, and E represented + +one isoform that was +highly expressed. + +And so if we think about +how to use our read + +coverage as a guide to +determining isoform prevalence, + +we'll be in good shape. + +And really, that's the +best evidence we have. + +We have two sources +of evidence, right? + +We have our junction +crossing reads, which tell us + +which exons are being +spliced together, + +that helps us both compute +the set of possible isoforms + +and estimate their prevalence. + +The other thing we +have is the reads + +that actually +simply cover exons. + +And their relative +prevalence can also + +help us compute the relative +amounts of different isoforms. + +So in order to do this, we can +think about what reads tell us. + +And some reads will +exclude certain isoforms. + +So if we consider the +reads that we have, + +we can think about reads that +cross particular junctions that + +are inclusion reads +saying that-- for example, + +in this case, the top +reads are indicating + +that the middle white exon is +being included in a transcript + +whereas the bottom +reads are exclusion + +reads indicating that that +white exon in the middle + +is being spliced out. + +So what we would +like to do, then, + +is to build a +probabilistic model that + +takes into account what we know +about what a read tells us. + +Because each read is +a piece of evidence. + +And we're going to use +that read like detectives. + +We're going to go in and +we're going to try and analyze + +all of the different +reads we see for a gene + +and use it to +weight what we think + +is happening with +the different isoform + +expressions in the pool of +reads that we're observing. + +And in order to do +so, we will have + +to build a function +that describes + +the probability of +seeing a read given + +the expression of a +particular isoform. + +So the essential idea is this-- +for the next three slides, + +I want to build a model of +the probability of seeing + +a read conditioned upon a +particular isoform being + +expressed. + +All right? + +So there are three +ways to approach this. + +One is that I can +see a read that I + +know is incompatible +with a given isoform. + +And therefore, the +probability of seeing that + +read given the isoform is 0. + +And that's perfectly fine. + +And this can either happen +with a single ended read + +or with a paired end read. + +And it's a conditional +probability. + +So the probability of seeing +read i given and isoform j + +can be 0. + +Another possibility is that, +if I have a transcript-- + +now recall that the +transcript has been spliced. + +So what we're looking at +is the entire sequence + +of the spliced isoform. + +And we see a read. + +And the read can land anywhere +within that transcript. + +Let's assume, for +the time being, + +we're looking at +single ended read. + +Then, the probability +of seeing that read + +land in that transcript +is 1 over the length + +of the transcript-- all +right-- at a particular base. + +So this read is compatible +with that transcript. + +And we can describe the +probability in this fashion. + +It's also possible for us to +consider paired end reads. + +And if we have +paired end reads, we + +can describe a +probability function + +that has two +essential components. + +The denominator +is still the same. + +That is, the likelihood +of the read aligning + +at a particular +position is going + +to be 1 over the length +of the entire transcript. + +The numerator is +different though. + +We're going to compute +the length of the read + +that we have, or the implied +length of the paired end read, + +and ask, what's the +likelihood of seeing that. + +So we don't know the exact +length, recall, of the insert. + +When we're looking +at paired end reads, + +we can only estimate +how long the fragment + +is that we're sequencing. + +And so we are going to have a +probabilistic interpretation + +of how long the piece of RNA +is that we actually wound up + +sequencing the ends of. + +And that is placed +in the numerator, + +which scales the 1 over l sub j. + +So this gives us a +probability for seeing + +a read in a particular +transcript that + +accounts for the +fact that we have + +to back both ends +to that transcript. + +OK? + +So we have three possibilities +that we've described, + +one, where a particular read is +incompatible with an isoform, + +two, where we had +a single end read + +mapping to an isoform, +which is simply + +1 over the length +of the isoform, + +and three, where +we're mapping paired + +end reads to an isoform, +which includes uncertainty + +about where it will map, +which is the 1 over l sub j, + +and also uncertainty about the +length of the fragment itself, + +which is encoded in +the F function, which + +is a distribution +over fragment lengths. + +OK. + +So once we have +this structure, we + +can then estimate +isoform expression. + +Now we talked before, when +we talked about ChIP-seq + +last time, the idea of +estimating proportions. + +And the essential idea +here is that if we + +want to compute the +probability of a read given, + +in this case, a mixture of +isoforms, that's simply going + +to be-- let's see, what +variable did I use? + +Yeah-- the estimated +concentration + +of that isoform times the +probability of the read as + +seen in that isoform. + +So for an individual read, we +can estimate its likelihood + +given this mixture. + +And then the product +around the outside + +describes how to +estimate the probability + +of the entire basket of reads +that we see for that gene. + +And what we would like to do +is to pick psi, in this case, + +to maximize the likelihood +of the observed reads. + +So what psi is +going to do is it's + +going to give us the fraction +of each isoform that we see. + +Are there any questions +about the idea + +of isoform quantitation? + +Yes. + +AUDIENCE: I'm a little lost in-- +in the last full slide review, + +you were describing these three +cases for excluded, single, + +and paired reads. + +So we're computing the +different probabilities + +for both ends to happen in a +transcript, of for just one, + +or-- + +PROFESSOR: It depends. + +The second and third +cases depend upon + +whether we're +analyzing single ended + +reads or paired end reads. + +And so we wouldn't use both +of them at the same time. + +In other words, if you only +have single ended data, + +you would use the second +case that we showed. + +And if you had +paired end data, you + +would use the third +case that we showed. + +AUDIENCE: OK. + +PROFESSOR: Question, yes. + +AUDIENCE: Sorry. + +I noticed that the single +end reads case-- could you + +explain the intuition behind +that probability [INAUDIBLE]? + +PROFESSOR: Sure. + +The intuition behind +that probability + +is that we're asking-- +so here is a transcript. + +And we're assuming, what is +the probability of a read given + +that it came from +this transcript. + +OK? + +What's the probability of +observing a particular read? + +And the probability of +observing it lining up + +at a particular position +is 1 over the length + +of this transcript. + +And so the probability actually +includes the idea of alignment + +at a particular position +in the transcript. + +OK? + +So obviously, the +probability's 1 + +if we assume it comes from here +if we don't consider this fact. + +But if we want to ask where +it lines up in the transcript, + +it's going to be 1 over l sub j. + +OK? + +AUDIENCE: So we assume that +it's uniformly possible? + +PROFESSOR: That it's +uniformly possible, + +which gets us to a good point. + +I'm glad you asked +that question. + +Sometimes we would +have more reads + +at the three prime end of +a transcript than the five + +prime end. + +Can anybody imagine why? + +Yes. + +AUDIENCE: Because you're +pulling on the poly-A tails. + +PROFESSOR: Yeah. + +So this actually was +purified by the poly-A tail. + +And we're pulling on this. + +We're purifying by it. + +And if there's breakage +of these transcripts + +as it goes through the +biochemical processing, + +we can get shorter +and shorter molecules. + +They all contain this bit. + +And the probability to contain +that whole thing actually + +decreases. + +So oftentimes there +is three prime bias + +in RNA-seq experiments one +needs to be mindful of. + +But we're assuming, today, +that there isn't such bias + +and that the probability's +equal that it + +maps someplace in +this transcript. + +OK? + +Does that answer your question? + +Yes. + +AUDIENCE: Sorry. + +I do have one more. + +Can you show us how +that extends, then, + +to the paired end read and where +the probability distribution-- + +PROFESSOR: Right. + +So if we go to paired end +reads, right, like this, + +this component is going to +be where it aligns, right? + +And then, the probability of the +length of this entire molecule + +is what I had up +there before, which + +is-- exactly how did I do that? + +So this is going to be-- +this is this bit, which + +is the implied length of this. + +OK? + +So if I map the +left and the right-- + +this component is where +the left end maps. + +OK? + +I take the left and the +right ends of the read + +that I have from +that transcript. + +And it has a particular +length on this transcript. + +OK? + +I'll call that length +l sub j of R sub i. + +Now remember, that +is not the same + +as the length in the genome. + +That's the length in this +transcript as it is spliced. + +OK? + +F is going to be the +probability distribution + +of the length of the fragments. + +So let's just say that they're +centered around 200 bases. + +OK? + +So if this is exactly 200 bases, +it's going to be quite likely. + +OK? + +But imagine that when +I map this fragment, + +this wound up being +400 bases apart. + +Then, this +distribution would tell + +is it's very unlikely that +I would see a fragment that + +mapped here and +mapped 400 bases up + +here, because my fragment +with distribution defined by F + +is 200 bases. + +So it's going to discount +that, the probability of that. + +So this term that the +probability of the read + +given the transcript +is the component + +of where it's aligning +times the likelihood + +that the implied +fragment length agrees + +with what we think +we have empirically. + +OK? + +Does that make sense? + +OK. + +Those are good questions. + +OK. + +So given this +framework, we can either + +use EM or other machine learning +like frameworks to maximize psi + +and to learn the +fraction of expression + +of each different isoform +from the observed data given + +the functions that we have. + +And just to give +you an idea, when + +this was done for +myogenesis, a program + +called Cufflinks, which +does this kind of process + +of identifying +isoform prevalences, + +was able to identify a +large number of transcripts. + +70% of the reads +were in previously + +annotated transcripts. + +But it also found 643 +new isoforms of genes + +in this single time series. + +And I posted one +of the papers that + +describes some this technology +on the Stellar site. + +But note that certain of the +genes have light coverage. + +And what we're seeing here is +that for genes are expressed + +in low copy numbers, +it's obviously + +more difficult to get +reads out of them. + +And I'm presuming, in this +particular experiment-- + +although I can't recollect-- +that the reason they don't see + +that many intronic reads is +they did poly-A purification. + +OK. + +So we've talked about +how to take our reads, + +build a probabilistic model, +estimate isoform prevalences. + +And we know how many reads +are mapping to a given gene. + +The question now +is whether or not + +we see differential +expression of a gene + +in different conditions. + +So I'd like to turn to the +analysis of differential + +expression unless there +are any final questions + +about the details of RNA-seq +and isoform estimation. + +This is your chance to +ask those hard questions. + +Yes. + +AUDIENCE: OK. + +I have a really silly question. + +But can you explain, really +quickly, what are isoforms? + +PROFESSOR: What an isoform is? + +AUDIENCE: Yeah. + +PROFESSOR: Sure. + +An isoform is a particular +splice variant of a gene. + +So a gene that has a +particular splicing pattern + +is called an isoform. + +So imagine we have three +exons, one, two, and three. + +And a transcript that has all +three would be one isoform. + +And another variant that omits +two would be a second isoform. + +So just one in three +would be an isoform. + +And each gene has a set +of isoforms it exhibits. + +And that depends upon how it's +regulated and whether or not + +any splicing is +constitutive-- it always + +happens-- or whether +or not it's regulated. + +And so in theory, +a gene with n exons + +has how many potential isoforms? + +It's 2 to the n. + +Because you can consider each +exon being included or omitted. + +All right. + +But that isn't +typically the case-- + +that there are many +fewer isoforms than that. + +But in general, an isoform +refers to a particular splice + +variant of a gene. + +Yes. + +AUDIENCE: I just want to +make sure I have everything + +correctly. + +When you're using single +legged or pair end reads, + +you can get excluded +ends, right? + +So you can get that in both +cases, whether or not you're-- + +PROFESSOR: Well, it depends. + +Once again, it's +somewhat probabilistic + +where the reads actually hit. + +Because if all the +reads only hit exons, + +and you didn't +get any junctions, + +and none of your paired end +reads crossed junctions, + +then you wouldn't +actually have exclusion. + +All right? + +AUDIENCE: But it's possible for +using both types of sequencing? + +PROFESSOR: Yes, it's possible +with both types of sequencing. + +In fact, oftentimes, +what people do + +is that they will count +junction crossing reads. + +If you have a large +enough number of reads + +in your sequencing, say, +100 base pairs at least, + +then a large number +of your reads + +are going to be-- not a large, +but a significant fraction-- + +will be exon crossing. + +And you'll be able to count the +number of exon-exon junctions + +you have of different types. + +And that will give +you an estimate + +of how much splicing is going +on and will help validate + +the kinds of conclusions +that come out of programs + +like Cufflinks or MISO, which is +another program from the Burge + +Laboratory that is used to +estimate isoform prevalence. + +Yes. + +AUDIENCE: So even +given this information, + +you can't say which exons go +with which exons necessarily, + +except paralogs, right? + +Because the reads, in +general, aren't long enough + +to span an exon. + +And therefore we wouldn't +know, for example, + +that a given transcript is +exons one, five, and six. + +You could only know that exons +five and six went together. + +PROFESSOR: That is +not strictly true + +if you have paired end +reads and your fragments + +are long enough to span exons. + +But in general, you're correct. + +And that's why modern +sequencing technologies that + +are coming down the pike +that can do 25 kilobase reads + +are so important for doing +things just like that. + +Yes. + +AUDIENCE: In your diagram +of the read up there, + +are the boxes the actual genome +or RNA sequence and the line + +in between the artificial linker +that you added when you seq + +ref'd? + +PROFESSOR: Ah, that's +a good question. + +The question is, +is this the linker + +and these are the +actual sequences. + +No. + +What I'm drawing here is +that these are the bits + +that we actually get +to see the sequence of. + +We sequence from both +ends of a molecule. + +This is the part of the fragment +that we haven't sequenced + +because our reads +aren't long enough. + +And so the entire fragment +might be 300 bases long. + +If this is 100 and this is +100, then the unobserved part + +is 100 in the middle. + +OK? + +And that's called +the insert length, + +the entire length +of the molecule. + +And we get to choose how +long these fragments are up + +to a maximum size. + +Contemporary +sequencers don't really + +like fragments over 1,000 bases. + +And the performance +starts falling off + +when you get close +to that number. + +So people, typically, +are operating + +in a more optimal +range of fragments + +that are a few +hundred bases long. + +Any other questions? + +OK. + +So I wanted to briefly talk +about hypothesis testing. + +Because we're going +to be needing it + +for determining when things +are really differentially + +expressed. + +So I'm just going to +show you some data + +and ask you a few +questions about it. + +So here are two different +scatters of data. + +Well, actually, it's +exactly the same data. + +But we have two +different bits to it. + +We have two +independent Gaussians + +that are fit to the data, +from gene one and gene two. + +And another fit +uses two Gaussians + +that have a correlation +structure between them. + +And the question +is whether or not + +the null hypothesis or +the alternative hypothesis + +is more reasonable. + +And typically, when +we say reasonable, + +we want to judge whether +or not it's significant. + +Significance +typically talks about, + +what's the chance +that the data we saw + +occurred at random given +the null hypothesis. + +So what's the chance +it was generated + +by the null hypothesis +versus the chance + +that it was generated by +the alternative hypothesis? + +Now the problem is that +alternative hypotheses, + +typically, are more complex. + +And a more complex model will +always explain data better. + +So we need to have +a principled way + +of asking the question, given +that the alternative hypothesis + +is always going to +do a better job, + +does it do such a better +job that it can exclude + +the null hypothesis at a +particular probability level. + +OK? + +So here are two different +models for these data. + +The null model, H0, +is that they came + +from two independent Gaussians. + +The alternative model, +H1, is that they + +came from two +correlated Gaussians. + +And then we can +ask whether or not + +H1 is sufficiently more likely +to warrant our rejecting H0 + +and accepting H1. + +Now as I said, H1 is always +going to fit the data better. + +So the probability +of that collection + +of points evaluated with the +H1 model, fit to the data, + +is always going to be superior. + +So we need to have +a way to compare + +the probability of the data +given H1 versus the data + +given H0 in a way that +allows us to judge + +the probability that the data +via H0 occurred at random. + +In this particular case, +the data supports H1. + +And let's see why. + +So this is a key idea here. + +How many people have heard of +likelihood ratio statistics + +before? + +OK. + +About half the class. + +OK. + +So here's the idea. + +The idea is that what +we're going to do + +is we're going to +compute a test statistic. + +And the test statistic +is going to be + +a function of the observed data. + +And it's 2 times the log of +the probability of the observed + +data given H1 over the +probability of the observed + +data given H0. + +OK? + +Now we know that +this is always going + +to have a higher value than the +probability in the denominator. + +So this is always going +to be greater than 1. + +So the test statistic will +always be greater than 0 + +since we're operating +in the log domain. + +OK? + +The question is-- we +know that this is always + +going to be better, even when +the data was generated from H0. + +But when is this +sufficiently better + +for us to believe that H0 is not +true and we should accept H1? + +What we need is a distribution +for this test statistic + +that occurred if H0 was true. + +And that distribution allows +us to compute the probability + +that an observed value +for the test statistic + +occurred, even in the presence-- +assuming that H0 is true. + +OK. + +So this depends upon +the number of degrees + +of freedom difference +between H1 and H0. + +How many degrees of +freedom are there + +in H1 in this model up here? + +How many parameters +do we get to pick? + +AUDIENCE: Six. + +PROFESSOR: Hmm? + +AUDIENCE: Six. + +PROFESSOR: Six? + +AUDIENCE: Two means and four-- + +PROFESSOR: Two means +and four coherences. + +And for H0? + +AUDIENCE: Just four. + +PROFESSOR: Four. + +So what's the +difference in the number + +of degrees of freedom +between H1 and H0? + +It's two. + +So the test statistic +is parametrized + +by the difference in number +of degrees of freedom. + +And so what we see, then, is +something that looks like this. + +We see a test statistic where +this is the probability of it, + +on the y-axis, and the test +statistic on the x-axis. + +But as the test statistic +gets larger and larger, + +the probability that it +occurred with H0 being true + +gets smaller and smaller. + +So let us just suppose that we +took our data from our model + +that we observed. + +And we computed the test +statistic at a particular value + +call T observed. + +So this is the actual +value that we computed out + +of our likelihood ratio test. + +What we would like to ask +is, what's the probability + +that our test statistic is +greater than or equal to T + +observed given that +H0 is true, which + +means that we're +going to consider + +all the tail of +this distribution. + +Because we want to also consider +the case where T observed + +was even greater +than what we saw. + +And this gives us a way of +computing the probability + +that H0 is true given +the test statistic. + +And this gives us our p-value. + +OK? + +So this is a way of, +in general, comparing + +two probabilistic models and +analyzing the significance + +of adding extra degrees +of freedom to the model. + +Typically, what we'll be +doing in today's lecture + +is asking whether or +not-- if we let the means + +change, for example, +between two conditions-- + +we get a sufficient +improvement in our ability + +to predict the data that our +test statistic will allow + +us to reject the null hypothesis +that the means are the same. + +OK. + +I'm going to stop +here and see if there + +are any questions +at all about this. + +AUDIENCE: Yes. + +Where did the degrees of +freedom enter into the equation? + +PROFESSOR: Where did the degrees +of freedom enter into this? + +Great question. + +The chi-square tables +that you look up + +are indexed by the +number of degrees + +of freedom of difference. + +OK? + +And so whenever you +compute a chi-squared, + +you will compute +it with the number + +of degrees of +freedom difference. + +Any other questions? + +OK. + +So let's now turn to evaluating +RNA-seq data once again. + +And I'm going to describe +a method called DESeq + +for determining +differential expression. + +And in our analysis, +what we're going to do + +is we're going to let i range +over a gene or an isoform. + +j is an experiment. + +And there may be +multiple experiments + +in the same condition +that are replicates. + +And Kij is the number of +counts observed for i and j. + +So that's the expression of gene +or isoform i in experiment j. + +Now what we need +to do, however, is + +to normalize experiments +against one another. + +And the normalization +factor s sub j + +is computed for a +particular experiment. + +And it's used to normalize +all of the values + +in that experiment. + +And if all the experiments +were completely identical-- + +the read depth was identical +and everything was the same-- + +then all of the s +sub js would be 1. + +If you had an experiment that +had exactly twice as many reads + +as the other experiments, +it's s sub j would be 2. + +So this scale factor is +used to normalize things + +in our next slide, as we'll see. + +And the essential +idea is that we're + +going to take the median +value of this ratio. + +And the reason that the +denominator is a geometric mean + +is so that no one experiment +dominates the average. + +They all have equal +weight for the average. + +But the geometric mean +is simply the product + +of all of the expressions for +a particular median gene taken + +to the root m power +to get them back + +to the value for a +single experiment. + +And that is the +normalizing factor + +for the numerator, which +is the number of counts + +for a particular gene. + +OK? + +So we're just doing +median style normalization + +where s sub j is a scale factor. + +Once again, if all the +experiments were the same, + +s sub j would be 1. + +If one particular experiment +had twice as many counts + +as another experiment +uniformly, s + +sub j would be 2, just +for that experiment. + +Any questions about +the scale factor? + +Yes. + +AUDIENCE: Sorry, +what is the term + +on the bottom-- in +the denominator? + +PROFESSOR: That's +a normalizing term + +across-- that's the geometric +mean of all the experiments put + +together. + +All right? + +So because it's the product +of all the experiments-- m + +experiments-- then, +rooted m, it's + +equal to the geometric mean +of a single experiment. + +Any other questions? + +Yes. + +AUDIENCE: Are we normalizing +different experiments + +to each other or +different replicates + +of a single experiment? + +PROFESSOR: In this particular +case, each one of these + +is a different replicate. + +OK? + +So j is ranging over +different replicates, + +not over conditions, right now. + +So each replicate, +each experiment, + +gets its own normalizing factor. + +We'll see, in a moment, how to +put those replicates together + +to build statistical strength. + +But we need-- since each +replicate has its own read + +depth, we have to normalize +each one independently. + +OK? + +So what we then do is we compute +an expression for a condition. + +Now a condition, +we're going to call p. + +And q sub ip is the +normalized expression + +for gene slash isoform +i in condition p. + +So a condition may have +multiple replicates in it. + +So we're going to +average, over all + +of the replicates, the +average expression, + +as you can see here. + +So we're summing over +all the replicates + +for a given condition. + +We're going to take +each replicate, + +normalize it by its scale +factor we just computed, + +and then compute the normalized +expression for a gene + +or an isoform in that +particular condition. + +Is that clear to everybody, +what's going on here? + +Now I'm describing this to +you because the key fact is + +the next line, which +is that we compute + +the mean for a +particular replicate + +by taking the normalized +expression for a gene + +and then reverse correcting +it back to scaling it + +back up again for that +particular replicate + +by multiplying by s sub j. + +But the most important +thing is what's + +on the right hand side, +which is that the variance is + +equal to the mean plus this +function of the expression. + +And the reason this +is important is + +that most other models for +modeling expression data + +use Poisson models. + +And we've already seen, +when we talked about library + +complexity, that Poisson +models don't work that well + +all the time. + +So this is using a negative +binomial function, once again. + +We saw negative +binomials before. + +We're modelling both the +mean and the variance. + +And the variance is a +function, a linear function + +and a non-linear +function, of the mean. + +So what's going to +happen, then, is + +that we're going to use the +negative binomial to compute + +the probability of observing +the data in a given condition. + +And we can either combine +conditions and ask, + +what's the probability of +seeing the conditions combined + +with a single mean and variance, +or we can separate them + +into a more complex +H1 hypothesis and ask, + +what's the probability of +seeing them with separate means + +and variances, +and then do a test + +to see how significant the +difference is to determine + +whether or not we can exclude +the fact that the genes are + +expressed at the same level. + +And to give you an intuitive +idea of what's going on, + +this is a plot from the paper +showing the relationship + +between mean expression +and variance. + +Recall, for Poisson, that +variance is equal to mean. + +We only have one parameter +to tune for Poisson, + +which is lambda. + +The purple line is Poisson. + +And you can check and +see that the mean's + +equal to the variance +in that case. + +What DESeq does is it fits the +orange line to the observed + +data. + +Yes. + +AUDIENCE: I don't know where +the v sub p comes from. + +Where is that, again? + +PROFESSOR: That's the function. + +V sub p, in that +equation up there, + +is the function that +we're fitting-- that's + +the solid orange +line-- to the observed + +relationship between mean +and variance in the data. + +OK? + +So DESeq fits that function. + +EdgeR is another technique that +does not fit and instead uses + +the estimate that's the dotted +line, which isn't as good. + +So a lot of people +use DESeq these days + +for doing differential +expression analysis + +because it allows the +variance to change + +as the mean increases. + +And this is the case for +these type of count data. + +Before I go on though, +I'll pause and see + +if there are any questions at +all about what's going on here. + +Yes. + +AUDIENCE: You said that mu sub +p, then, is the [INAUDIBLE] + +to the data. + +I'm confused. + +How do we fit that function, +or where does that come from? + +PROFESSOR: You +mean the mu sub p? + +AUDIENCE: Yes. + +PROFESSOR: That function is fit. + +And the paper +describes exactly how + +it's fit, which I posted +on the Stellar site. + +But it's a nonlinear +function of q, in this case. + +Good question. + +Any other questions? + +OK. + +So once again, we +have two hypotheses, + +the null hypothesis that A and +B are expressing identically, + +H1, A and B +differentially express. + +We can compute the number +of degrees of freedom. + +And we can do a likelihood +ratio test, if we'd like, + +to compute the +probability of H0. + +And our model in this case is +the negative binomial model + +of the data, which +fits the data better. + +And that's why DESeq +does a better job + +than other methodologies. + +Because it provides a +better approximation + +to the underlying noise. + +And the next slide +shows what you get out + +of this kind of analysis, +where the little red dots are + +the genes that have +been called significant + +using Benjamini-Hochberg +correction, which + +we talked about previously. + +And you can see how, as the mean +increases, the required log 2 + +fold change comes down +to be significant. + +So oftentimes, you'll +see plots like this + +in papers that describe how they +actually computed what genes + +were differentially expressed. + +Any questions at all? + +Yes. + +AUDIENCE: Why is it +that the significance is + +lower as the mean increases? + +PROFESSOR: Why the +significance is lower? + +AUDIENCE: Or the threshold. + +PROFESSOR: Oh, because +as you increase + +the number of observations, +the mean value theorem + +is going to cause +things to actually get + +closer and closer to 0. + +And so you need less of +a fold change difference + +to be significant as you get +more and more observations. + +And other questions? + +OK. + +So now we're going to +delve into one other area. + +How many people have done +hypergeometric tests before? + +OK. + +So we're going to talk +about hypergeometric tests. + +So imagine that we have a +universe, for simplicity, + +of 1,000 genes. + +OK? + +So we have this universe. + +And we have, B is a set of +genes that there are 30 of them. + +And there's another set, +A, of which there are 20. + +And the overlap between these +two is a total of three genes. + +So it might be that +A is the set of genes + +that are differentially +expressed + +between two conditions. + +B is the set of genes +that, you happen to know, + +have a particular annotation. + +For example, they're involved +in stress response in the cell. + +And you'd like to +know whether or not + +the genes that are +differentially expressed + +have a significant component of +stress response related genes + +or whether or not this +occurred at random. + +OK? + +So we need to compute that. + +So how many ways +could we choose B? + +Well, if we are going to use-- +this is n1, n2, this is big N, + +and this is k. + +All right? + +So the number of ways I can +choose B is big N choose n2. + +That's the number of ways I can +choose B. Is everybody with me + +on that? + +Yeah? + +OK. + +How many ways can I +choose three elements out + +of A, these three that +are going to overlap? + +Well, that's going +to be n1 choose k. + +So that's how many ways I can +choose these three elements. + +And then, how many ways could I +choose the other elements of B? + +So once again, I'm figuring +out how I can choose B. Well, + +how could I choose +the rest of B? + +Well, how many elements do I +have to choose, of B, here? + +Well, B is n too big. + +But I've already +chosen k of them. + +Right? + +All right. + +Sorry, it's the +other way around. + +The universe I can +pick from is 1,000, + +which is all the elements, minus +the elements of A that I've + +already chosen from +to get those three. + +And then I need to pick the +27 things they don't overlap + +with A. So 27 things +that don't overlap with A + +would be n2 minus k. + +So this is the +number ways to choose + +B given this set of constraints. + +This is the number of ways to +choose B given no constraints. + +So the probability +that I have overlap + +of exactly k is equal +to this, which is, + +how many ways are there +with no constraints + +and how many ways +are there given + +that I have an overlap of k. + +All right? + +And typically, what +I want to ask is, + +what is the probability +that my observed overlap + +is greater than or equal to k. + +So this case, the +overlap would be three. + +But I also would need +to consider the fact + +that I might have four, +or five, or six, which + +would be even more unlikely, +but still significant. + +So if you look at the +exact computation, + +the probability of +three here is 0.017. + +And the probability that I +have three or more is 0.02. + +So that's still +pretty significant. + +Unlikely that would +occur by chance. + +Right? + +That I have three or more genes +overlapping in this situation + +could only happen +two out of 100 times. + +Does everybody understand +what's going on here? + +Any questions at all? + +So you're all now +hypergeometric whizzes, right? + +All right? + +Fantastic. + +OK. + +Now we're going to turn to +a final kind of analysis. + +How many people have heard of +principal component analysis + +before? + +How many people know how to do +principal component analysis? + +A few. + +OK. + +Great. + +Yes. + +AUDIENCE: Sorry, +could you just briefly + +mention, again, where exactly do +we use the hypergeometric test? + +What kinds of questions are +we asking when we do that? + +PROFESSOR: Typically, +they're overlap questions. + +So you're asking-- you have a +universe of objects, right-- + +like, in this case, genes. + +And you have a subset of +20 and a subset of 30. + +Let's say these are the +differentially expressed genes. + +These are genes in the +stress response pathway. + +They overlap by three genes. + +Does that actually +occur at random or not? + +All right? + +If I told you that there are +a much smaller number of genes + +and the stress response +genes were very much larger, + +it could be much easier for +that overlap to occur at random. + +Good question. + +Any other questions? + +OK. + +So the next part of +lecture is entitled + +"multivariate Gaussians +are your friends." + +OK? + +They are friendly. + +They're like a puppy dog. + +They are just wonderful to +play with and very friendly. + +And the reason most people get +a little turned off by them + +is because they get this-- +the first thing they're shown + +is this very hairy +looking exponential + +which describes what they are. + +And so I'm going to shy away +from complicated looking + +exponentials and give you the +puppy dog, my favorite way + +of looking at +multivariate Gaussians. + +OK? + +Which, I think, is a +great way to look at them. + +And the reason we need to +look at multivariate Gaussians + +is that they help +us understand what + +is going on with principal +component analysis in a very + +straightforward way. + +And the reason that we want +to use principal component + +analysis is that +we're going to be + +able to reveal hidden factors +and structures in our data. + +And they're also +going to allow us + +to reduce the +dimensionality of the data. + +And we'll see why in a moment. + +But here is the friendly version +of multivariate Gaussians. + +And let me describe to you why +I think this is so friendly. + +So we're all familiar with +unidimensional Gaussians + +like this. + +Centered at zero. + +They have variance 1. + +Just very friendly +univariate Gaussians, right? + +Everybody's familiar with those? + +Normal distributions? + +So let's suppose +that we just take + +a whole collection of those. + +And we say that we +have a vector z that + +is sampled from a collection +of univariate Gaussians. + +And it can be as +long as we like. + +OK? + +But they're all sampled +from the same distribution. + +And what we're going to say is +that our multivariate Gaussian, + +x, is going to be a matrix +times z plus a mean. + +And so what this +matrix is going to do + +is it's going to take all +of our univariate Gaussians + +and combine them to produce +our multivariate Gaussian. + +All right? + +So the structure +of this matrix will + +describe how these single +variate Gaussians are + +being mixed together to produce +this multivariate distribution. + +And you can imagine +various structures + +for this matrix A. Right? + +And the covariance +matrix, sigma, + +which describes the structure +of this multivariate Gaussian, + +is shown on this slide to +be equal to A A transpose. + +And thus, if we knew this +matrix A, which we may not know, + +we'd be able to compute the +covariance matrix directly. + +OK? + +Let me take that one more time. + +We take a bunch of +univariate Gaussians, + +make a vector z out of them. + +And just for +clarity, right, we're + +going to talk about matrices and +vectors as rows across columns. + +So this is n by 1. + +This is n by n. + +This is n by 1. + +And this is n by 1. + +OK? + +That's the dimensionality +of these various objects + +we're dealing with here. + +So we get this vector +of univariate Gaussians. + +We apply this matrix n +to combine them together. + +We get out our multivariate +Gaussian offset by some mean. + +Is everybody happy +with that so far? + +Yes? + +No? + +You're suspending disbelief +for the next slide. + +Is that-- OK. + +Well, here's the next +thing I'd like to say, + +is that the variance of +a vector-- we'll call it + +v-- times x, which +is a random variable, + +is going to be equal +to-- x is derived + +from this distribution-- +v transpose sigma + +v. And the demonstration of +that is on the top of this page. + +So the variance of this +vector-- sorry, the projection + +of this random variable +onto this vector-- + +is going to give you a +variance in this direction + +as that product. + +So what we would +like to do is this. + +We would like to find v +sub i, which are vectors, + +to maximize variance +of v sub i transpose x + +such that v sub i transpose +v sub i is equal to 1. + +In other words, they're +unit length vectors. + +So these are going to be +called the eigenvectors. + +And if we think about the +structure that we desire, + +what we'll find is that +they satisfy the constraint + +that the covariance matrix +times an eigenvector + +is equal to the +eigenvalue associated + +with that vector times +the vector itself. + +And with a little manipulation-- +if we multiply both sides by v + +sub i transpose-- v sub i equals +v sub i transpose lambda sub i + +sigma squared v sub i-- and +we move these guys around, + +v sub i transpose +sigma v sub i is + +equal to-- these two +guys, multiplied together, + +equal 1-- lambda sub i squared. + +This, we see up above, +is equal to the variance + +when it's projected +in the direction of v. + +And so lambda sub i squared is +simply the variance associated + +with that direction. + +So the question then becomes, +how do we find these things. + +And how do we discover +these magic eigenvectors + +that are directions in which +this multivariate Gaussian has + +its variance maximized? + +And we can do this by +singular value decomposition. + +So we can compute this +covariance matrix. + +So we compute sigma +from the data. + +And then we do a singular +value decomposition + +such that sigma is equal +to U S U transpose. + +And that's what the singular +value decomposition does + +for us is it +decomposes the sigma + +matrix into these +components where + +S is a diagonal matrix that +contains the eigenvalues + +and U is a column. + +Each column is an eigenvector. + +So in doing a singular +value decomposition, + +we get the eigenvalues +and the eigenvectors. + +The other thing, you +recall, was that sigma + +was equal to A A transpose +when we started off. + +A was the matrix that we used to +make our multivariate Gaussian + +out of our univariate Gaussians. + +And thus, what we can observe is +that our multivariate Gaussian + +x is equal to U S to the +1/2 times z plus a mean. + +So here is what's going when we +make a multivariate Gaussian is + +we're taking a bunch of +univariate Gaussians, + +we're scaling them, and +we're rotating them. + +OK? + +And that makes a +multivariate Gaussian. + +And then we offset this +whole thing by a mean. + +Because we also have to do +rotations around the origin. + +So the way I think about +multivariate Gaussians + +is that it is a +scaling and a rotation + +of univariate Gaussians. + +And implicit in that +scaling and rotation + +is the discovery of the +major directions of variance + +in the underlying +data as represented + +by the eigenvectors. + +And the eigenvalues tell +you how much of the variance + +is accounted for in each +one of those dimensions. + +Are there any +questions about that? + +I hope there are. + +Yes. + +AUDIENCE: How do you +compute sigma from the data? + +Is it some magical process? + +PROFESSOR: The sigma of +the value of decomposition? + +AUDIENCE: No. + +So-- + +PROFESSOR: How do you +compute sigma from the data? + +AUDIENCE: Yeah, the first step. + +PROFESSOR: That is +shown in equation seven. + +So you can compute the means. + +And you know you have x, +which are observed values. + +So you compute that expectation. + +And that is sigma. + +OK? + +Good question. + +Any other questions? + +OK. + +So we have these +eigenvectors and eigenvalues, + +which represent the +vectors of maximum variance + +in the underlying data. + +And we can use these to organize +data by projecting observations + +onto these eigenvectors-- +or they're sometimes + +called principal components-- +defined dimensions + +of variability that help us +organize our underlying data. + +We'll come back to +that in a moment. + +OK. + +Any other questions about +principal component analysis? + +Yes. + +AUDIENCE: [INAUDIBLE] +e was expectation + +when you were +calculating the second? + +PROFESSOR: Yes, e is the +expectation is correct. + +AUDIENCE: And also +what that means. + +PROFESSOR: It's the +average expected value. + +So in the case of +computing sigma, + +you would compute the expected +value of that inner equation + +across all the data +points that you see. + +So you'd sum up all +the values and divide + +by the number of +things that you had. + +Any other questions? + +OK. + +So just for calibration for +next year, how many people + +think they've got a general +idea of what principal component + +analysis is-- a general idea? + +Uh-oh. + +How many people who thought +it was really interesting + +were sort of completely +baffled about halfway through? + +OK. + +All right. + +Well, I think that +recitation can + +help with some of +those questions. + +But if anybody has a question +they'd like to ask now-- No? + +It's that far gone? + +I mean, the thing with +this sort of analysis + +is that if your matrix algebra +is a little rusty, then, + +when you start looking +at equations like that, + +you can get a little +lost sometimes. + +All right. + +Well, let's turn, then-- if +there aren't any brave souls + +who wish to ask +a question, we'll + +turn to single cell +RNA-seq analysis. + +So I'm a firm believer +that single cell analysis + +of biological samples is +the next big frontier. + +And it's being made possible +through devices like this. + +This is a Fluidigm C1 chip, +which has 96 different reaction + +wells, which allows +you, in each well, + +to process a single +cell independently. + +And the little winds are ways +to get reagents into those cells + +to do things like produce +RNA-seq ready materials. + +And when you do +single cell analysis, + +you can take apart what's +happening in a population. + +So an early paper asked some +fairly fundamental but simple + +questions. + +For example, if you take +two 10,000 cell aliquots + +of the same culture, and you +profile them independently, + +and you ask how well to the +expression values for each gene + +agree between sample +A and sample B, + +you expect there to be a very +good agreement between sample A + +and sample B in these +10,000 cell cultures. + +A second question is, now, +if you take, say, 14 cells + +from those cultures and you +profile them independently, + +and you ask, how well +do they correlate + +with what you saw in the +10,000 cell experiment, that + +will tell you something about +the population heterogeneity + +that you're observing. + +Because if they correlate +perfectly with the 10,000 cell + +experiment, then you +really know that there's + +no point in looking at +individual cells in some sense, + +because they're all the same. + +Seen one, seem them all. + +Right? + +But if you find +that each cell has + +its own particular +expression fingerprint + +and what you're seeing in the +10,000 cell average experiment + +wipes out those +fingerprints, then you + +know it's very important to +analyze each cell individually. + +So the analysis that was done +asked exactly that question. + +So here's what I'll +show you in these plots. + +So here is, on the upper left, +the 10,000 cell experiment + +versus the 10,000 +cell experiment. + +And as you can see, the +correlation coefficient + +is quite high-- 0.98-- +and looks very, very good + +of experiment one +versus experiment two, + +or rep one, rep two. + +Here is a separate +experiment which + +is looking at two +individual cells + +and asking-- and +plotting, for each gene, + +the expression in one +cell versus the gene + +in the other cell. + +And you can see that the +correlation coefficient's 0.54. + +And there's actually +a fairly wide spread. + +In fact, there are genes that +are expressed in one cell that + +are not expressed in the +other cell, and vice versa. + +So the expression of +these individual cells + +it's quite divergent. + +And the final panel +shows how-- down here-- + +how a single cell +average on the y-axis + +relates to the 10,000 +cell experiment. + +But given the middle +panel-- the panel B there-- + +that is showing the fact that +two single cells don't really + +relate that well to another, +it bags other questions. + +For example, are the +isoforms of the genes that + +are being expressed the same +in those distinct cells? + +And so panel D +shows isoforms that + +are the same across each one +of the single cells being + +profiled, which is the +solid bar at the top. + +And the bottom couple +of rows in figure D + +are the 10,000 cell +experiment average. + +But panel E is the +most interesting, + +perhaps, which is that the +isoforms for those four genes + +are being +differentially expressed + +in different individual cells. + +And that's further supported +by taking two of those genes + +and doing fluorescent in situ +histochemistry and microscopy, + +and looking at the +number of RNA molecules + +for each one of those, and +noting that it corresponds + +to what's seen in the +upper right hand panel. + +So we see that in +individual cells, + +different isoforms +are being expressed. + +Now these cells were +derived from bone marrow. + +And they're exposed +to lipopolysaccharide + +to activate an immune response. + +So they are clearly not all +behaving exactly the same. + +And to further elucidate this, +the authors of this paper + +took the gene +expressions that they + +saw for a given cell +as a large vector + +and computed the +principal components, + +and then projected the cells +into the first and second + +principal component +or eigenvector space. + +And as you can see, there is +a distinct separation of three + +of the cells from the +rest of the cells, where + +three of the cells, +which correlate well + +with principal component +one, are thought + +to be mature cells that +express certain cell surface + +proteins whereas the ones +on the left-- the maturing + +cells-- the triangle +depicted cells-- + +express certain cytokines +under the maturing legend + +there, on the clustergram +on the right-hand side. + +And thus, the first +principal component + +was able to separate those +two different broad classes + +of cells. + +So it looks like there are +at least two different kinds + +of cells in this population. + +And then, the authors +asked another question, + +which is, can they take +individual cell data + +and look at the relationship +between pairs of genes + +to see which genes +are co-expressed. + +And the hypothesis +is that genes that + +are co-expressed +in individual cells + +make up individual +regulatory circuits. + +And so they hypothesize that +the genes LRF7 and IFIT1 + +and STAT2 and LRF7 are all in an +anti-viral regulatory circuit. + +They then ask the question, +if they knocked out + +LRF7, which is the second +panel on the right-hand side, + +would they oblate +downstream gene expression. + +And they partially did. + +And they thought that since +STAT2 and LRF7 are both thought + +to be regulators of +the circuit and they're + +both downstream of the +interfering receptor, + +they thought if they knocked +out the interfering receptor, + +they would oblate most of +the anti-viral cluster, + +which, in fact, they did. + +So what this is suggesting +is that, first, single cell + +analysis is +extraordinarily important + +to understand what's going +on in individual cells. + +Because in a cell culture, the +cells can be quite different. + +And secondarily, it's +possible, within the context + +of individual single +cell analysis, + +to be able to pick out +regulatory circuits that + +wouldn't be as +evident when you're + +looking at cells en masse. + +And finally-- I'll thank Mike +for the next two slides-- + +I wanted to point +out that quality + +metrics for RNA-seq data for +single cells is very important. + +And we talked about library +complexity earlier in the term. + +And here, you can see that as +library complexity increases, + +expression of coefficient +of variation, which + +is the standard +deviation over the mean, + +comes down as you get +sufficient library complexity. + +And furthermore, as library +complexity increases, + +mean expression increases. + +And the cells that are in +red were classified as bad + +by microscopy, from the Fluidigm +instrument processing step. + +So I think you can see that +single cell analysis is going + +to be extraordinarily +important and can reveal + +a lot of information that is +not present in these large batch + +experiments. + +And it's coming +to a lab near you. + +So on that note, I'll thank +you very much for today. + +And we'll see you +later in the term. + +And Professor Burge will +return at the next lecture. + +Thanks very much. \ No newline at end of file diff --git a/N9f0MIzNcmI.txt b/N9f0MIzNcmI.txt new file mode 100644 index 0000000000000000000000000000000000000000..9f43c90df1c10bd487e7c665a5f5e3caf4eb66cc --- /dev/null +++ b/N9f0MIzNcmI.txt @@ -0,0 +1,1083 @@ +align:start position:0% + +so case a wig Zeeman effect so what are + + align:start position:0% +so case a wig Zeeman effect so what are + + + align:start position:0% +so case a wig Zeeman effect so what are +our states here we discovered that and + + align:start position:0% +our states here we discovered that and + + + align:start position:0% +our states here we discovered that and +we know those are the couple basis + + align:start position:0% +we know those are the couple basis + + + align:start position:0% +we know those are the couple basis +states and the states of h 0 tilde + + align:start position:0% +states and the states of h 0 tilde + + + align:start position:0% +states and the states of h 0 tilde +eigenstates are eigenstates they're the + + align:start position:0% +eigenstates are eigenstates they're the + + + align:start position:0% +eigenstates are eigenstates they're the +approximate that eigenstates are the + + align:start position:0% +approximate that eigenstates are the + + + align:start position:0% +approximate that eigenstates are the +states n l j MJ and the energies were + + align:start position:0% +states n l j MJ and the energies were + + + align:start position:0% +states n l j MJ and the energies were +energies of dependent on N and J we had + + align:start position:0% + + + + align:start position:0% + +so the 1 s 1/2 to s 1/2 to P 1/2 + 2 p3 + + align:start position:0% +so the 1 s 1/2 to s 1/2 to P 1/2 + 2 p3 + + + align:start position:0% +so the 1 s 1/2 to s 1/2 to P 1/2 + 2 p3 +halves roughly to remind you of what + + align:start position:0% +halves roughly to remind you of what + + + align:start position:0% +halves roughly to remind you of what +happened the original states were + + align:start position:0% +happened the original states were + + + align:start position:0% +happened the original states were +shifted and we use the J quantum number + + align:start position:0% +shifted and we use the J quantum number + + + align:start position:0% +shifted and we use the J quantum number +in here and and those are our multiplets + + align:start position:0% +in here and and those are our multiplets + + + align:start position:0% +in here and and those are our multiplets +those are our multiplicity we have a lot + + align:start position:0% +those are our multiplicity we have a lot + + + align:start position:0% +those are our multiplicity we have a lot +of degeneracy as usual so this is the + + align:start position:0% +of degeneracy as usual so this is the + + + align:start position:0% +of degeneracy as usual so this is the +generous e here and the generous e here + + align:start position:0% +generous e here and the generous e here + + + align:start position:0% +generous e here and the generous e here +because a multiplet p3 halves is j equal + + align:start position:0% +because a multiplet p3 halves is j equal + + + align:start position:0% +because a multiplet p3 halves is j equal +three-halves and that's four states here + + align:start position:0% +three-halves and that's four states here + + + align:start position:0% +three-halves and that's four states here +you have two states and here you have + + align:start position:0% +you have two states and here you have + + + align:start position:0% +you have two states and here you have +two states as well so quite a bit of + + align:start position:0% +two states as well so quite a bit of + + + align:start position:0% +two states as well so quite a bit of +states that are degenerate + + align:start position:0% +states that are degenerate + + + align:start position:0% +states that are degenerate +so in principle when we do the Zeeman + + align:start position:0% +so in principle when we do the Zeeman + + + align:start position:0% +so in principle when we do the Zeeman +splitting we may + + align:start position:0% +splitting we may + + + align:start position:0% +splitting we may +have to consider the full matrix n LJ MJ + + align:start position:0% +have to consider the full matrix n LJ MJ + + + align:start position:0% +have to consider the full matrix n LJ MJ +Delta H demon and L prime J and prime J + + align:start position:0% +Delta H demon and L prime J and prime J + + + align:start position:0% +Delta H demon and L prime J and prime J +so what are our degeneracies our + + align:start position:0% +so what are our degeneracies our + + + align:start position:0% +so what are our degeneracies our +degeneracies are when you have a given + + align:start position:0% +degeneracies are when you have a given + + + align:start position:0% +degeneracies are when you have a given +value of J so they did a degenerate + + align:start position:0% +value of J so they did a degenerate + + + align:start position:0% +value of J so they did a degenerate +subspace can have different else for + + align:start position:0% +subspace can have different else for + + + align:start position:0% +subspace can have different else for +example here but the same J and + + align:start position:0% +example here but the same J and + + + align:start position:0% +example here but the same J and +therefore different MJ's or within a + + align:start position:0% +therefore different MJ's or within a + + + align:start position:0% +therefore different MJ's or within a +given J multiplet it might have + + align:start position:0% +given J multiplet it might have + + + align:start position:0% +given J multiplet it might have +different MJ's so this is the scope of + + align:start position:0% +different MJ's so this is the scope of + + + align:start position:0% +different MJ's so this is the scope of +the degeneracy and in principle we may + + align:start position:0% +the degeneracy and in principle we may + + + align:start position:0% +the degeneracy and in principle we may +have to diagonalize a matrix like that + + align:start position:0% +have to diagonalize a matrix like that + + + align:start position:0% +have to diagonalize a matrix like that +by looking at the degenerate spaces if + + align:start position:0% +by looking at the degenerate spaces if + + + align:start position:0% +by looking at the degenerate spaces if +you are doing the level 2 you would have + + align:start position:0% +you are doing the level 2 you would have + + + align:start position:0% +you are doing the level 2 you would have +to discuss this four states here you + + align:start position:0% +to discuss this four states here you + + + align:start position:0% +to discuss this four states here you +would have to discuss these other four + + align:start position:0% +would have to discuss these other four + + + align:start position:0% +would have to discuss these other four +states happily we don't have to do that + + align:start position:0% +states happily we don't have to do that + + + align:start position:0% +states happily we don't have to do that +much because as usual + + align:start position:0% +much because as usual + + + align:start position:0% +much because as usual +well Delta H diamond is proportional to + + align:start position:0% +well Delta H diamond is proportional to + + + align:start position:0% +well Delta H diamond is proportional to +L Z plus two s Z and this commutes with + + align:start position:0% +L Z plus two s Z and this commutes with + + + align:start position:0% +L Z plus two s Z and this commutes with +l squared with Delta H Zeeman l squared + + align:start position:0% +l squared with Delta H Zeeman l squared + + + align:start position:0% +l squared with Delta H Zeeman l squared +commutes with ne L operator is certainly + + align:start position:0% +commutes with ne L operator is certainly + + + align:start position:0% +commutes with ne L operator is certainly +commute with n es operator they don't + + align:start position:0% +commute with n es operator they don't + + + align:start position:0% +commute with n es operator they don't +even talk to each other and therefore l + + align:start position:0% +even talk to each other and therefore l + + + align:start position:0% +even talk to each other and therefore l +squared commutes with l cement which + + align:start position:0% +squared commutes with l cement which + + + align:start position:0% +squared commutes with l cement which +means that when L is different from L + + align:start position:0% +means that when L is different from L + + + align:start position:0% +means that when L is different from L +prime this matrix element has to vanish + + align:start position:0% +prime this matrix element has to vanish + + + align:start position:0% +prime this matrix element has to vanish +this is our remark from perturbation + + align:start position:0% +this is our remark from perturbation + + + align:start position:0% +this is our remark from perturbation +theory long long ago + + align:start position:0% +theory long long ago + + + align:start position:0% +theory long long ago +you have another operator for which the + + align:start position:0% +you have another operator for which the + + + align:start position:0% +you have another operator for which the +states have different eigenvalues + + align:start position:0% +states have different eigenvalues + + + align:start position:0% +states have different eigenvalues +commutes with your perturbation the + + align:start position:0% +commutes with your perturbation the + + + align:start position:0% +commutes with your perturbation the +matrix element of the perturbation must + + align:start position:0% +matrix element of the perturbation must + + + align:start position:0% +matrix element of the perturbation must +vanish between those states so we don't + + align:start position:0% +vanish between those states so we don't + + + align:start position:0% +vanish between those states so we don't +have Agins states like that and when L + + align:start position:0% +have Agins states like that and when L + + + align:start position:0% +have Agins states like that and when L +is equal to L prime are ready so we + + align:start position:0% +is equal to L prime are ready so we + + + align:start position:0% +is equal to L prime are ready so we +focus on L equals to L Prime + + align:start position:0% +focus on L equals to L Prime + + + align:start position:0% +focus on L equals to L Prime +so we only need to worry within + + align:start position:0% +so we only need to worry within + + + align:start position:0% +so we only need to worry within +multiplets so you have n LJ MJ Delta H + + align:start position:0% +multiplets so you have n LJ MJ Delta H + + + align:start position:0% +multiplets so you have n LJ MJ Delta H +demon now and LJ MJ prime is an issue of + + align:start position:0% +demon now and LJ MJ prime is an issue of + + + align:start position:0% +demon now and LJ MJ prime is an issue of +M J prime now but demon thing commutes + + align:start position:0% +M J prime now but demon thing commutes + + + align:start position:0% +M J prime now but demon thing commutes +with j z jz commute with delta h demon + + align:start position:0% + + + + align:start position:0% + +JZ is LZ plus s z and z components in + + align:start position:0% +JZ is LZ plus s z and z components in + + + align:start position:0% +JZ is LZ plus s z and z components in +angular momentum to identical components + + align:start position:0% +angular momentum to identical components + + + align:start position:0% +angular momentum to identical components +always commute of course + + align:start position:0% +always commute of course + + + align:start position:0% +always commute of course +so jz commute with delta h seaman so + + align:start position:0% +so jz commute with delta h seaman so + + + align:start position:0% +so jz commute with delta h seaman so +this thing will vanish and less M is + + align:start position:0% +this thing will vanish and less M is + + + align:start position:0% +this thing will vanish and less M is +equal to M Prime and that's great + + align:start position:0% +equal to M Prime and that's great + + + align:start position:0% +equal to M Prime and that's great +because you're back to non degenerate + + align:start position:0% +because you're back to non degenerate + + + align:start position:0% +because you're back to non degenerate +perturbation Theory Hall matrix this + + align:start position:0% +perturbation Theory Hall matrix this + + + align:start position:0% +perturbation Theory Hall matrix this +Zeeman thing could have turned out to be + + align:start position:0% +Zeeman thing could have turned out to be + + + align:start position:0% +Zeeman thing could have turned out to be +complicated matrices now it's perfectly + + align:start position:0% +complicated matrices now it's perfectly + + + align:start position:0% +complicated matrices now it's perfectly +diagonal in this basis there's nothing + + align:start position:0% +diagonal in this basis there's nothing + + + align:start position:0% +diagonal in this basis there's nothing +to worry about here except that it's + + align:start position:0% +to worry about here except that it's + + + align:start position:0% +to worry about here except that it's +still not easy to compute as we will see + + align:start position:0% +still not easy to compute as we will see + + + align:start position:0% +still not easy to compute as we will see +so what what do we need to compute we'll + + align:start position:0% +so what what do we need to compute we'll + + + align:start position:0% +so what what do we need to compute we'll +have the first order Corrections due to + + align:start position:0% +have the first order Corrections due to + + + align:start position:0% +have the first order Corrections due to +Zeeman on the m l j MJ basis is equal + + align:start position:0% +Zeeman on the m l j MJ basis is equal + + + align:start position:0% +Zeeman on the m l j MJ basis is equal +well the Zeeman Hamiltonian has an e + + align:start position:0% +well the Zeeman Hamiltonian has an e + + + align:start position:0% +well the Zeeman Hamiltonian has an e +over to MC so let's put it there e let's + + align:start position:0% +over to MC so let's put it there e let's + + + align:start position:0% +over to MC so let's put it there e let's +put the big close to the e to MC and now + + align:start position:0% +put the big close to the e to MC and now + + + align:start position:0% +put the big close to the e to MC and now +we have to do n LJ m j LZ plus 2 SZ + LJ + + align:start position:0% + + + + align:start position:0% + +energy perfectly they either know and + + align:start position:0% +energy perfectly they either know and + + + align:start position:0% +energy perfectly they either know and +that's + + align:start position:0% +that's + + + align:start position:0% +that's +non-degenerate perturbation theory is + + align:start position:0% +non-degenerate perturbation theory is + + + align:start position:0% +non-degenerate perturbation theory is +gonna give us all the energies we want + + align:start position:0% +gonna give us all the energies we want + + + align:start position:0% +gonna give us all the energies we want +all the splittings we want so basically + + align:start position:0% +all the splittings we want so basically + + + align:start position:0% +all the splittings we want so basically +what's going to happen as you didn't see + + align:start position:0% +what's going to happen as you didn't see + + + align:start position:0% +what's going to happen as you didn't see +here is that things don't mix everything + + align:start position:0% +here is that things don't mix everything + + + align:start position:0% +here is that things don't mix everything +is there honestly these two levels have + + align:start position:0% +is there honestly these two levels have + + + align:start position:0% +is there honestly these two levels have +been a split these two levels I'm going + + align:start position:0% +been a split these two levels I'm going + + + align:start position:0% +been a split these two levels I'm going +to split these four levels are going to + + align:start position:0% +to split these four levels are going to + + + align:start position:0% +to split these four levels are going to +split everything is gonna split here + + align:start position:0% +split everything is gonna split here + + + align:start position:0% +split everything is gonna split here +the remarkable thing of this formula and + + align:start position:0% +the remarkable thing of this formula and + + + align:start position:0% +the remarkable thing of this formula and +it's going to keep us busy for about 10 + + align:start position:0% +it's going to keep us busy for about 10 + + + align:start position:0% +it's going to keep us busy for about 10 +15 more minutes is that this thing this + + align:start position:0% +15 more minutes is that this thing this + + + align:start position:0% +15 more minutes is that this thing this +matrix element is proportional to MJ so + + align:start position:0% +matrix element is proportional to MJ so + + + align:start position:0% +matrix element is proportional to MJ so +the state split proportional to the M + + align:start position:0% +the state split proportional to the M + + + align:start position:0% +the state split proportional to the M +quantum number the state with M equal + + align:start position:0% +quantum number the state with M equal + + + align:start position:0% +quantum number the state with M equal +three halves will split three times as + + align:start position:0% +three halves will split three times as + + + align:start position:0% +three halves will split three times as +much as the state with M equal 1/2 and + + align:start position:0% +much as the state with M equal 1/2 and + + + align:start position:0% +much as the state with M equal 1/2 and +that's not obvious here + + align:start position:0% +that's not obvious here + + + align:start position:0% +that's not obvious here +it's a remarkable result it's part of + + align:start position:0% +it's a remarkable result it's part of + + + align:start position:0% +it's a remarkable result it's part of +what's called the vintner Edward theorem + + align:start position:0% +what's called the vintner Edward theorem + + + align:start position:0% +what's called the vintner Edward theorem +something that you study in graduate + + align:start position:0% +something that you study in graduate + + + align:start position:0% +something that you study in graduate +quantum mechanics but we're going to see + + align:start position:0% +quantum mechanics but we're going to see + + + align:start position:0% +quantum mechanics but we're going to see +a bit of it the beginning of it in this + + align:start position:0% +a bit of it the beginning of it in this + + + align:start position:0% +a bit of it the beginning of it in this +computation and it's a fairly remarkable + + align:start position:0% +computation and it's a fairly remarkable + + + align:start position:0% +computation and it's a fairly remarkable +result so the remarkable result here + + align:start position:0% +result so the remarkable result here + + + align:start position:0% +result so the remarkable result here +markable is that e ones are proportional + + align:start position:0% +markable is that e ones are proportional + + + align:start position:0% +markable is that e ones are proportional +to MJ and that defines a linear + + align:start position:0% +to MJ and that defines a linear + + + align:start position:0% +to MJ and that defines a linear +splitting because it's linearly + + align:start position:0% +splitting because it's linearly + + + align:start position:0% +splitting because it's linearly +proportional to the magnitude of the + + align:start position:0% +proportional to the magnitude of the + + + align:start position:0% +proportional to the magnitude of the +magnetic field and divides the states + + align:start position:0% +magnetic field and divides the states + + + align:start position:0% +magnetic field and divides the states +nicely so we want to understand this + + align:start position:0% +nicely so we want to understand this + + + align:start position:0% +nicely so we want to understand this +matrix element and there's a little + + align:start position:0% +matrix element and there's a little + + + align:start position:0% +matrix element and there's a little +thing we can do notice that LZ plus 2's + + align:start position:0% +thing we can do notice that LZ plus 2's + + + align:start position:0% +thing we can do notice that LZ plus 2's +Z is equal to JZ + SZ you can take one + + align:start position:0% +Z is equal to JZ + SZ you can take one + + + align:start position:0% +Z is equal to JZ + SZ you can take one +of + + align:start position:0% +of + + + align:start position:0% +of +the SZ is and complete jz and you're + + align:start position:0% +the SZ is and complete jz and you're + + + align:start position:0% +the SZ is and complete jz and you're +left with that so the matrix element n + + align:start position:0% +left with that so the matrix element n + + + align:start position:0% +left with that so the matrix element n +LJ m LZ + 2 SZ m LJ MJ is equal if you + + align:start position:0% +LJ m LZ + 2 SZ m LJ MJ is equal if you + + + align:start position:0% +LJ m LZ + 2 SZ m LJ MJ is equal if you +have a jz that gives you just something + + align:start position:0% +have a jz that gives you just something + + + align:start position:0% +have a jz that gives you just something +proportional to H MJ plus m l j m j SZ + + + align:start position:0% +proportional to H MJ plus m l j m j SZ + + + + align:start position:0% +proportional to H MJ plus m l j m j SZ + +LJ m j so okay a little bit of the + + align:start position:0% +LJ m j so okay a little bit of the + + + align:start position:0% +LJ m j so okay a little bit of the +mystery baby seems to you at least + + align:start position:0% +mystery baby seems to you at least + + + align:start position:0% +mystery baby seems to you at least +consistent here I said this matrix + + align:start position:0% +consistent here I said this matrix + + + align:start position:0% +consistent here I said this matrix +element turns out to be proportional to + + align:start position:0% +element turns out to be proportional to + + + align:start position:0% +element turns out to be proportional to +M J and certainly this piece having to + + align:start position:0% +M J and certainly this piece having to + + + align:start position:0% +M J and certainly this piece having to +do with the J component here is + + align:start position:0% +do with the J component here is + + + align:start position:0% +do with the J component here is +proportional to M J the mystery that + + align:start position:0% +proportional to M J the mystery that + + + align:start position:0% +proportional to M J the mystery that +remains is why this matrix element would + + align:start position:0% +remains is why this matrix element would + + + align:start position:0% +remains is why this matrix element would +be proportional to M J \ No newline at end of file diff --git a/O06G95nJrQI.txt b/O06G95nJrQI.txt new file mode 100644 index 0000000000000000000000000000000000000000..5f89e755f53f03b559c48d1f15325e66a46c9656 --- /dev/null +++ b/O06G95nJrQI.txt @@ -0,0 +1,8024 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +so we are going to spend today + + align:start position:0% +so we are going to spend today + + + align:start position:0% +so we are going to spend today +mostly + + align:start position:0% +mostly + + + align:start position:0% +mostly +on the cloudiest clap around equation + + align:start position:0% + + + + align:start position:0% + +and remember we're still in chapter + + align:start position:0% +and remember we're still in chapter + + + align:start position:0% +and remember we're still in chapter +seven + + align:start position:0% +seven + + + align:start position:0% +seven +of the text okay good so what is the CC + + align:start position:0% +of the text okay good so what is the CC + + + align:start position:0% +of the text okay good so what is the CC +equation the CC equation is the + + align:start position:0% +equation the CC equation is the + + + align:start position:0% +equation the CC equation is the +following + + align:start position:0% + + + + align:start position:0% + +we have a phase diagram here I'm going + + align:start position:0% +we have a phase diagram here I'm going + + + align:start position:0% +we have a phase diagram here I'm going +to draw a little close-up section + + align:start position:0% +to draw a little close-up section + + + align:start position:0% +to draw a little close-up section +of a phase diagram and this is very + + align:start position:0% +of a phase diagram and this is very + + + align:start position:0% +of a phase diagram and this is very +generic + + align:start position:0% +generic + + + align:start position:0% +generic +and all right so let's say we have + + align:start position:0% +and all right so let's say we have + + + align:start position:0% +and all right so let's say we have +Alpha + + align:start position:0% +Alpha + + + align:start position:0% +Alpha +I like to use Colors Let's make alpha + + align:start position:0% +I like to use Colors Let's make alpha + + + align:start position:0% +I like to use Colors Let's make alpha +kind of teal + + align:start position:0% +kind of teal + + + align:start position:0% +kind of teal +and let's say we have beta + + align:start position:0% +and let's say we have beta + + + align:start position:0% +and let's say we have beta +and beta is going to be + + align:start position:0% +and beta is going to be + + + align:start position:0% +and beta is going to be +kind of purple + + align:start position:0% +kind of purple + + + align:start position:0% +kind of purple +and we have a coexistence line + + align:start position:0% +and we have a coexistence line + + + align:start position:0% +and we have a coexistence line +between them + + align:start position:0% +between them + + + align:start position:0% +between them +and at any point on that line we have a + + align:start position:0% +and at any point on that line we have a + + + align:start position:0% +and at any point on that line we have a +slope + + align:start position:0% +slope + + + align:start position:0% +slope +right we have rise over run + + align:start position:0% +right we have rise over run + + + align:start position:0% +right we have rise over run +so here's a little DP + + align:start position:0% +so here's a little DP + + + align:start position:0% +so here's a little DP +and here's a little DT + + align:start position:0% + + + + align:start position:0% + +okay what makes these phases + + align:start position:0% +okay what makes these phases + + + align:start position:0% +okay what makes these phases +stable well over here mu of alpha is + + align:start position:0% +stable well over here mu of alpha is + + + align:start position:0% +stable well over here mu of alpha is +less the MU of beta right that's that's + + align:start position:0% +less the MU of beta right that's that's + + + align:start position:0% +less the MU of beta right that's that's +the definition we developed + + align:start position:0% +the definition we developed + + + align:start position:0% +the definition we developed +last time and over here + + align:start position:0% +last time and over here + + + align:start position:0% +last time and over here +mu of beta is less than mu of alpha + + align:start position:0% + + + + align:start position:0% + +but + + align:start position:0% + + + + align:start position:0% + +on the coexistence line + + align:start position:0% + + + + align:start position:0% + +all right last time we developed the + + align:start position:0% +all right last time we developed the + + + align:start position:0% +all right last time we developed the +conditions + + align:start position:0% +conditions + + + align:start position:0% +conditions +for two-phase equilibrium so on that + + align:start position:0% +for two-phase equilibrium so on that + + + align:start position:0% +for two-phase equilibrium so on that +coexistence line mu of alpha which is of + + align:start position:0% +coexistence line mu of alpha which is of + + + align:start position:0% +coexistence line mu of alpha which is of +course a function of temperature and + + align:start position:0% +course a function of temperature and + + + align:start position:0% +course a function of temperature and +pressure equals mu of theta which is a + + align:start position:0% +pressure equals mu of theta which is a + + + align:start position:0% +pressure equals mu of theta which is a +function of temperature and pressure + + align:start position:0% + + + + align:start position:0% + +so if I take a little jog + + align:start position:0% +so if I take a little jog + + + align:start position:0% +so if I take a little jog +I take a little jog from here let's see + + align:start position:0% +I take a little jog from here let's see + + + align:start position:0% +I take a little jog from here let's see +and start running out of colors pretty + + align:start position:0% +and start running out of colors pretty + + + align:start position:0% +and start running out of colors pretty +soon + + align:start position:0% + + + + align:start position:0% + +let's take a little jog let's walk a + + align:start position:0% +let's take a little jog let's walk a + + + align:start position:0% +let's take a little jog let's walk a +little bit + + align:start position:0% +little bit + + + align:start position:0% +little bit +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +if I'm going to stay on the line I need + + align:start position:0% +if I'm going to stay on the line I need + + + align:start position:0% +if I'm going to stay on the line I need +demu of alpha + + align:start position:0% +demu of alpha + + + align:start position:0% +demu of alpha +which is of course a function of + + align:start position:0% +which is of course a function of + + + align:start position:0% +which is of course a function of +temperature and pressure to be equal to + + align:start position:0% +temperature and pressure to be equal to + + + align:start position:0% +temperature and pressure to be equal to +D mu of beta + + align:start position:0% +D mu of beta + + + align:start position:0% +D mu of beta +as a function of temperature and + + align:start position:0% +as a function of temperature and + + + align:start position:0% +as a function of temperature and +pressure all right I want you to think + + align:start position:0% +pressure all right I want you to think + + + align:start position:0% +pressure all right I want you to think +about uh this line as a Mountain Ridge + + align:start position:0% +about uh this line as a Mountain Ridge + + + align:start position:0% +about uh this line as a Mountain Ridge +and you're walking along the Mountain + + align:start position:0% +and you're walking along the Mountain + + + align:start position:0% +and you're walking along the Mountain +Ridge + + align:start position:0% +Ridge + + + align:start position:0% +Ridge +and you want to stay on the ridge + + align:start position:0% +and you want to stay on the ridge + + + align:start position:0% +and you want to stay on the ridge +because if you fall off the ridge you + + align:start position:0% +because if you fall off the ridge you + + + align:start position:0% +because if you fall off the ridge you +you fall very far it hurts so and the + + align:start position:0% +you fall very far it hurts so and the + + + align:start position:0% +you fall very far it hurts so and the +ridge is a curvy line and so if you want + + align:start position:0% +ridge is a curvy line and so if you want + + + align:start position:0% +ridge is a curvy line and so if you want +to stay on the ridge right you just + + align:start position:0% +to stay on the ridge right you just + + + align:start position:0% +to stay on the ridge right you just +can't walk in any direction for as long + + align:start position:0% +can't walk in any direction for as long + + + align:start position:0% +can't walk in any direction for as long +as you like + + align:start position:0% +as you like + + + align:start position:0% +as you like +if you want to stay in the ridge you + + align:start position:0% +if you want to stay in the ridge you + + + align:start position:0% +if you want to stay in the ridge you +can't walk in X and Y as much as you + + align:start position:0% +can't walk in X and Y as much as you + + + align:start position:0% +can't walk in X and Y as much as you +like Northwest + + align:start position:0% +like Northwest + + + align:start position:0% +like Northwest +east and south you need to stay on the + + align:start position:0% +east and south you need to stay on the + + + align:start position:0% +east and south you need to stay on the +ridge so you only have one degree of + + align:start position:0% +ridge so you only have one degree of + + + align:start position:0% +ridge so you only have one degree of +Freedom right if you walk a little bit + + align:start position:0% +Freedom right if you walk a little bit + + + align:start position:0% +Freedom right if you walk a little bit +north you've got to adjust a little bit + + align:start position:0% +north you've got to adjust a little bit + + + align:start position:0% +north you've got to adjust a little bit +west or east to stay on the ridge + + align:start position:0% +west or east to stay on the ridge + + + align:start position:0% +west or east to stay on the ridge +that's pretty intuitive if you're on a + + align:start position:0% +that's pretty intuitive if you're on a + + + align:start position:0% +that's pretty intuitive if you're on a +Mountain Ridge you don't have to go + + align:start position:0% +Mountain Ridge you don't have to go + + + align:start position:0% +Mountain Ridge you don't have to go +through all that thinking and think + + align:start position:0% +through all that thinking and think + + + align:start position:0% +through all that thinking and think +about multivariable calculus you just + + align:start position:0% +about multivariable calculus you just + + + align:start position:0% +about multivariable calculus you just +don't want to fall off the ridge but + + align:start position:0% +don't want to fall off the ridge but + + + align:start position:0% +don't want to fall off the ridge but +that's what's going on here we want to + + align:start position:0% +that's what's going on here we want to + + + align:start position:0% +that's what's going on here we want to +stay on the coexistence line This is the + + align:start position:0% +stay on the coexistence line This is the + + + align:start position:0% +stay on the coexistence line This is the +condition to stay on the line + + align:start position:0% +condition to stay on the line + + + align:start position:0% +condition to stay on the line +right the potentials are equal and so if + + align:start position:0% +right the potentials are equal and so if + + + align:start position:0% +right the potentials are equal and so if +I take a little step I've got to stay + + align:start position:0% +I take a little step I've got to stay + + + align:start position:0% +I take a little step I've got to stay +take a step such that the changes of + + align:start position:0% +take a step such that the changes of + + + align:start position:0% +take a step such that the changes of +these chemical potentials are also equal + + align:start position:0% +these chemical potentials are also equal + + + align:start position:0% +these chemical potentials are also equal +so that I stay on the ridge + + align:start position:0% + + + + align:start position:0% + +okay questions on this concept because + + align:start position:0% +okay questions on this concept because + + + align:start position:0% +okay questions on this concept because +we're going to start evaluating this + + align:start position:0% +we're going to start evaluating this + + + align:start position:0% +we're going to start evaluating this +condition now so it's going to get kind + + align:start position:0% +condition now so it's going to get kind + + + align:start position:0% +condition now so it's going to get kind +of mathy + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so let's evaluate that condition that's + + align:start position:0% +so let's evaluate that condition that's + + + align:start position:0% +so let's evaluate that condition that's +the condition for the line + + align:start position:0% +the condition for the line + + + align:start position:0% +the condition for the line +all right so D Mu Alpha + + align:start position:0% +all right so D Mu Alpha + + + align:start position:0% +all right so D Mu Alpha +we know what this is who wants to give + + align:start position:0% +we know what this is who wants to give + + + align:start position:0% +we know what this is who wants to give +me an expression for D mu of alpha + + align:start position:0% + + + + align:start position:0% + +it's something times DT plus something + + align:start position:0% +it's something times DT plus something + + + align:start position:0% +it's something times DT plus something +times TP + + align:start position:0% + + + + align:start position:0% + +minus s DT plus VDP + + align:start position:0% + + + + align:start position:0% + +right you may recall that chemical + + align:start position:0% +right you may recall that chemical + + + align:start position:0% +right you may recall that chemical +potential is molar Gibbs free energy so + + align:start position:0% +potential is molar Gibbs free energy so + + + align:start position:0% +potential is molar Gibbs free energy so +we're seeing the same differential form + + align:start position:0% +we're seeing the same differential form + + + align:start position:0% +we're seeing the same differential form +here as we did + + align:start position:0% +here as we did + + + align:start position:0% +here as we did +a couple weeks ago now + + align:start position:0% + + + + align:start position:0% + +when we developed a differential form + + align:start position:0% +when we developed a differential form + + + align:start position:0% +when we developed a differential form +for indeed Gibbs right so the only thing + + align:start position:0% +for indeed Gibbs right so the only thing + + + align:start position:0% +for indeed Gibbs right so the only thing +I've done here is I'm expressing the + + align:start position:0% +I've done here is I'm expressing the + + + align:start position:0% +I've done here is I'm expressing the +molar Gibbs free energy as chemical + + align:start position:0% +molar Gibbs free energy as chemical + + + align:start position:0% +molar Gibbs free energy as chemical +potential and I'm adding the phase + + align:start position:0% +potential and I'm adding the phase + + + align:start position:0% +potential and I'm adding the phase +labels right because now I have a + + align:start position:0% +labels right because now I have a + + + align:start position:0% +labels right because now I have a +heterogeneous system multiple phases so + + align:start position:0% +heterogeneous system multiple phases so + + + align:start position:0% +heterogeneous system multiple phases so +I have to keep track of the phase levels + + align:start position:0% +I have to keep track of the phase levels + + + align:start position:0% +I have to keep track of the phase levels +okay so thank you for that I didn't see + + align:start position:0% +okay so thank you for that I didn't see + + + align:start position:0% +okay so thank you for that I didn't see +which rectangle answered that question + + align:start position:0% +which rectangle answered that question + + + align:start position:0% +which rectangle answered that question +but thank you for that + + align:start position:0% +but thank you for that + + + align:start position:0% +but thank you for that +um + + align:start position:0% +um + + + align:start position:0% +um +and likewise we have + + align:start position:0% +and likewise we have + + + align:start position:0% +and likewise we have +verbata + + align:start position:0% + + + + align:start position:0% + +okay so this is true right for Alpha and + + align:start position:0% +okay so this is true right for Alpha and + + + align:start position:0% +okay so this is true right for Alpha and +beta phase and I want the MU of alpha to + + align:start position:0% +beta phase and I want the MU of alpha to + + + align:start position:0% +beta phase and I want the MU of alpha to +be equal to D mu of beta so I'm going to + + align:start position:0% +be equal to D mu of beta so I'm going to + + + align:start position:0% +be equal to D mu of beta so I'm going to +combine these three lines + + align:start position:0% +combine these three lines + + + align:start position:0% +combine these three lines +right I'm going to plug in for D Mu + + align:start position:0% +right I'm going to plug in for D Mu + + + align:start position:0% +right I'm going to plug in for D Mu +Alpha I'm going to plug in for DBU beta + + align:start position:0% +Alpha I'm going to plug in for DBU beta + + + align:start position:0% +Alpha I'm going to plug in for DBU beta +I'm going to see what I get and so what + + align:start position:0% +I'm going to see what I get and so what + + + align:start position:0% +I'm going to see what I get and so what +I get is + + align:start position:0% +I get is + + + align:start position:0% +I get is +um what D Mu Alpha equals minus s Alpha + + align:start position:0% +um what D Mu Alpha equals minus s Alpha + + + align:start position:0% +um what D Mu Alpha equals minus s Alpha +DT plus v Alpha DP and that's going to + + align:start position:0% +DT plus v Alpha DP and that's going to + + + align:start position:0% +DT plus v Alpha DP and that's going to +be equal to minus s beta DT plus v beta + + align:start position:0% +be equal to minus s beta DT plus v beta + + + align:start position:0% +be equal to minus s beta DT plus v beta +DP I'm going to collect terms + + align:start position:0% + + + + align:start position:0% + +collect terms and I get S of alpha minus + + align:start position:0% +collect terms and I get S of alpha minus + + + align:start position:0% +collect terms and I get S of alpha minus +s of beta + + align:start position:0% +s of beta + + + align:start position:0% +s of beta +DT + + align:start position:0% +DT + + + align:start position:0% +DT +equals V of alpha minus V of beta + + align:start position:0% +equals V of alpha minus V of beta + + + align:start position:0% +equals V of alpha minus V of beta +DP + + align:start position:0% + + + + align:start position:0% + +and this here this is a transformation + + align:start position:0% +and this here this is a transformation + + + align:start position:0% +and this here this is a transformation +quantity + + align:start position:0% +quantity + + + align:start position:0% +quantity +I hope everyone watched the the three + + align:start position:0% +I hope everyone watched the the three + + + align:start position:0% +I hope everyone watched the the three +d's of thermodynamics uh + + align:start position:0% +d's of thermodynamics uh + + + align:start position:0% +d's of thermodynamics uh +and um + + align:start position:0% +and um + + + align:start position:0% +and um +if you did I hope you found it useful + + align:start position:0% +if you did I hope you found it useful + + + align:start position:0% +if you did I hope you found it useful +so this is a transformation quantity + + align:start position:0% +so this is a transformation quantity + + + align:start position:0% +so this is a transformation quantity +this is Delta s and this is Delta V + + align:start position:0% +this is Delta s and this is Delta V + + + align:start position:0% +this is Delta s and this is Delta V +as we go between phases beta Alpha is + + align:start position:0% +as we go between phases beta Alpha is + + + align:start position:0% +as we go between phases beta Alpha is +your transformation quantities + + align:start position:0% +your transformation quantities + + + align:start position:0% +your transformation quantities +and we're going to then + + align:start position:0% +and we're going to then + + + align:start position:0% +and we're going to then +divide through + + align:start position:0% + + + + align:start position:0% + +divide through and we're going to get + + align:start position:0% +divide through and we're going to get + + + align:start position:0% +divide through and we're going to get +an expression for the slope DP DT equals + + align:start position:0% +an expression for the slope DP DT equals + + + align:start position:0% +an expression for the slope DP DT equals +Delta s over Delta V + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +right + + align:start position:0% +right + + + align:start position:0% +right +that's pretty useful + + align:start position:0% + + + + align:start position:0% + +so now we have an expression for the + + align:start position:0% +so now we have an expression for the + + + align:start position:0% +so now we have an expression for the +slope the local slope of that coexist + + align:start position:0% +slope the local slope of that coexist + + + align:start position:0% +slope the local slope of that coexist +enzyme as a function of these + + align:start position:0% +enzyme as a function of these + + + align:start position:0% +enzyme as a function of these +transformation quantities + + align:start position:0% +transformation quantities + + + align:start position:0% +transformation quantities +and we have something else for an + + align:start position:0% +and we have something else for an + + + align:start position:0% +and we have something else for an +isothermal + + align:start position:0% + + + + align:start position:0% + +equilibrium transformation + + align:start position:0% + + + + align:start position:0% + +we know that Delta s + + align:start position:0% + + + + align:start position:0% + +equals Delta H over t + + align:start position:0% +equals Delta H over t + + + align:start position:0% +equals Delta H over t +so I can re-express this as + + align:start position:0% +so I can re-express this as + + + align:start position:0% +so I can re-express this as +g p DT + + align:start position:0% +g p DT + + + align:start position:0% +g p DT +equals + + align:start position:0% +equals + + + align:start position:0% +equals +Delta H over t + + align:start position:0% +Delta H over t + + + align:start position:0% +Delta H over t +Delta V + + align:start position:0% + + + + align:start position:0% + +so these are equivalent + + align:start position:0% + + + + align:start position:0% + +and these are called the cloud CS + + align:start position:0% + + + + align:start position:0% + +relation or equation + + align:start position:0% +relation or equation + + + align:start position:0% +relation or equation +okay so that that's that's where these + + align:start position:0% +okay so that that's that's where these + + + align:start position:0% +okay so that that's that's where these +are these are very famous + + align:start position:0% +are these are very famous + + + align:start position:0% +are these are very famous +um + + align:start position:0% +um + + + align:start position:0% +um +and so it's it's a differential equation + + align:start position:0% +and so it's it's a differential equation + + + align:start position:0% +and so it's it's a differential equation +it's a differential equation for this + + align:start position:0% +it's a differential equation for this + + + align:start position:0% +it's a differential equation for this +line right it's not an equation for the + + align:start position:0% +line right it's not an equation for the + + + align:start position:0% +line right it's not an equation for the +line but it's giving the slope of the + + align:start position:0% +line but it's giving the slope of the + + + align:start position:0% +line but it's giving the slope of the +line as a function of temperature and + + align:start position:0% +line as a function of temperature and + + + align:start position:0% +line as a function of temperature and +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +um + + align:start position:0% +um + + + align:start position:0% +um +where temperature and pressure + + align:start position:0% +where temperature and pressure + + + align:start position:0% +where temperature and pressure +parameterize these transformation + + align:start position:0% +parameterize these transformation + + + align:start position:0% +parameterize these transformation +quantities Delta seductively + + align:start position:0% + + + + align:start position:0% + +okay so this is in general true for any + + align:start position:0% +okay so this is in general true for any + + + align:start position:0% +okay so this is in general true for any +two-phase coexistence line + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +we're going to analyze it now for the + + align:start position:0% +we're going to analyze it now for the + + + align:start position:0% +we're going to analyze it now for the +case of vapor pressure + + align:start position:0% +case of vapor pressure + + + align:start position:0% +case of vapor pressure +because + + align:start position:0% +because + + + align:start position:0% +because +the equation simplify for vapor pressure + + align:start position:0% +the equation simplify for vapor pressure + + + align:start position:0% +the equation simplify for vapor pressure +and it's also a very useful + + align:start position:0% +and it's also a very useful + + + align:start position:0% +and it's also a very useful +result which is used in lots of + + align:start position:0% +result which is used in lots of + + + align:start position:0% +result which is used in lots of +different fields + + align:start position:0% +different fields + + + align:start position:0% +different fields +but before I move on to a specific case + + align:start position:0% +but before I move on to a specific case + + + align:start position:0% +but before I move on to a specific case +this should be a good time for questions + + align:start position:0% +this should be a good time for questions + + + align:start position:0% +this should be a good time for questions +on the general case + + align:start position:0% + + + + align:start position:0% + +can you explain when you + + align:start position:0% +can you explain when you + + + align:start position:0% +can you explain when you +um said like that for the isothermal + + align:start position:0% +um said like that for the isothermal + + + align:start position:0% +um said like that for the isothermal +equilibrium transformation why you + + align:start position:0% +equilibrium transformation why you + + + align:start position:0% +equilibrium transformation why you +specified that case sure I think that + + align:start position:0% +specified that case sure I think that + + + align:start position:0% +specified that case sure I think that +was Ryman but anyway thank you + + align:start position:0% +was Ryman but anyway thank you + + + align:start position:0% +was Ryman but anyway thank you +um so when we are having an isothermal + + align:start position:0% +um so when we are having an isothermal + + + align:start position:0% +um so when we are having an isothermal +transformation + + align:start position:0% +transformation + + + align:start position:0% +transformation +foreign + + align:start position:0% +foreign + + + align:start position:0% +foreign +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +if Alpha + + align:start position:0% +if Alpha + + + align:start position:0% +if Alpha +and beta can transform through each + + align:start position:0% +and beta can transform through each + + + align:start position:0% +and beta can transform through each +other at equilibrium that's the that's + + align:start position:0% +other at equilibrium that's the that's + + + align:start position:0% +other at equilibrium that's the that's +almost the meaning of coexistence then + + align:start position:0% +almost the meaning of coexistence then + + + align:start position:0% +almost the meaning of coexistence then +Delta G has to be zero + + align:start position:0% +Delta G has to be zero + + + align:start position:0% +Delta G has to be zero +that again was our our requirement for + + align:start position:0% +that again was our our requirement for + + + align:start position:0% +that again was our our requirement for +equilibrium at constant temperature and + + align:start position:0% +equilibrium at constant temperature and + + + align:start position:0% +equilibrium at constant temperature and +pressure + + align:start position:0% + + + + align:start position:0% + +and to give free energy of the two + + align:start position:0% +and to give free energy of the two + + + align:start position:0% +and to give free energy of the two +phases is equal or in other words the + + align:start position:0% +phases is equal or in other words the + + + align:start position:0% +phases is equal or in other words the +chemical potentials are equal + + align:start position:0% +chemical potentials are equal + + + align:start position:0% +chemical potentials are equal +so Delta G + + align:start position:0% +so Delta G + + + align:start position:0% +so Delta G +equals Delta + + align:start position:0% +equals Delta + + + align:start position:0% +equals Delta +H minus TS all right that's just from + + align:start position:0% +H minus TS all right that's just from + + + align:start position:0% +H minus TS all right that's just from +the definition and if it's isothermal + + align:start position:0% +the definition and if it's isothermal + + + align:start position:0% +the definition and if it's isothermal +this is Delta H minus t Delta s because + + align:start position:0% +this is Delta H minus t Delta s because + + + align:start position:0% +this is Delta H minus t Delta s because +T here is a fixed number for an + + align:start position:0% +T here is a fixed number for an + + + align:start position:0% +T here is a fixed number for an +isochonal transformation + + align:start position:0% +isochonal transformation + + + align:start position:0% +isochonal transformation +so this has to equal zero if phases + + align:start position:0% +so this has to equal zero if phases + + + align:start position:0% +so this has to equal zero if phases +Alpha and beta are in equilibrium + + align:start position:0% +Alpha and beta are in equilibrium + + + align:start position:0% +Alpha and beta are in equilibrium +so this is um + + align:start position:0% +so this is um + + + align:start position:0% +so this is um +useful and I mentioned this in the last + + align:start position:0% +useful and I mentioned this in the last + + + align:start position:0% +useful and I mentioned this in the last +class that the fact that + + align:start position:0% +class that the fact that + + + align:start position:0% +class that the fact that +Delta H minus t Delta s is zero + + align:start position:0% +Delta H minus t Delta s is zero + + + align:start position:0% +Delta H minus t Delta s is zero +for two phase equilibrium is is um + + align:start position:0% +for two phase equilibrium is is um + + + align:start position:0% +for two phase equilibrium is is um +it's used for instance + + align:start position:0% +it's used for instance + + + align:start position:0% +it's used for instance +in databases for Transformations you + + align:start position:0% +in databases for Transformations you + + + align:start position:0% +in databases for Transformations you +might see temperature and you might see + + align:start position:0% +might see temperature and you might see + + + align:start position:0% +might see temperature and you might see +Delta s or you might see Delta H and you + + align:start position:0% +Delta s or you might see Delta H and you + + + align:start position:0% +Delta s or you might see Delta H and you +might see Delta s right you might see a + + align:start position:0% +might see Delta s right you might see a + + + align:start position:0% +might see Delta s right you might see a +pair of numbers but you might not see + + align:start position:0% +pair of numbers but you might not see + + + align:start position:0% +pair of numbers but you might not see +all three + + align:start position:0% +all three + + + align:start position:0% +all three +because + + align:start position:0% +because + + + align:start position:0% +because +um having all three is redundant because + + align:start position:0% +um having all three is redundant because + + + align:start position:0% +um having all three is redundant because +you have to have this condition + + align:start position:0% +you have to have this condition + + + align:start position:0% +you have to have this condition +satisfied and if you uh you can you can + + align:start position:0% +satisfied and if you uh you can you can + + + align:start position:0% +satisfied and if you uh you can you can +you know you can check that if you open + + align:start position:0% +you know you can check that if you open + + + align:start position:0% +you know you can check that if you open +the textbook and you go to + + align:start position:0% +the textbook and you go to + + + align:start position:0% +the textbook and you go to +um + + align:start position:0% +um + + + align:start position:0% +um +phase Transformations for the elements + + align:start position:0% +phase Transformations for the elements + + + align:start position:0% +phase Transformations for the elements +you know there's a bunch of data here + + align:start position:0% +you know there's a bunch of data here + + + align:start position:0% +you know there's a bunch of data here +and if you like to you can go and check + + align:start position:0% +and if you like to you can go and check + + + align:start position:0% +and if you like to you can go and check +in for example silver here silver melts + + align:start position:0% +in for example silver here silver melts + + + align:start position:0% +in for example silver here silver melts +from FCC to liquid at 1235 Kelvin I know + + align:start position:0% +from FCC to liquid at 1235 Kelvin I know + + + align:start position:0% +from FCC to liquid at 1235 Kelvin I know +you can't read the numbers but I'm just + + align:start position:0% +you can't read the numbers but I'm just + + + align:start position:0% +you can't read the numbers but I'm just +pointing out the structure of the + + align:start position:0% +pointing out the structure of the + + + align:start position:0% +pointing out the structure of the +database and there's Delta s of the + + align:start position:0% +database and there's Delta s of the + + + align:start position:0% +database and there's Delta s of the +transformation and the Delta h of the + + align:start position:0% +transformation and the Delta h of the + + + align:start position:0% +transformation and the Delta h of the +transformation + + align:start position:0% +transformation + + + align:start position:0% +transformation +and you can confirm that Delta H minus t + + align:start position:0% +and you can confirm that Delta H minus t + + + align:start position:0% +and you can confirm that Delta H minus t +times Delta s is going to be zero for + + align:start position:0% +times Delta s is going to be zero for + + + align:start position:0% +times Delta s is going to be zero for +every single set of these + + align:start position:0% +every single set of these + + + align:start position:0% +every single set of these +so the Hoff is nice and it gives you + + align:start position:0% +so the Hoff is nice and it gives you + + + align:start position:0% +so the Hoff is nice and it gives you +extra information right but he could for + + align:start position:0% +extra information right but he could for + + + align:start position:0% +extra information right but he could for +example + + align:start position:0% +example + + + align:start position:0% +example +block out the temperature of the + + align:start position:0% +block out the temperature of the + + + align:start position:0% +block out the temperature of the +transformation and not list the melting + + align:start position:0% +transformation and not list the melting + + + align:start position:0% +transformation and not list the melting +temperature and you say what on Earth + + align:start position:0% +temperature and you say what on Earth + + + align:start position:0% +temperature and you say what on Earth +it's a table of melting temperatures and + + align:start position:0% +it's a table of melting temperatures and + + + align:start position:0% +it's a table of melting temperatures and +it doesn't lose the melting temperature + + align:start position:0% +it doesn't lose the melting temperature + + + align:start position:0% +it doesn't lose the melting temperature +what is he doing right well you can + + align:start position:0% +what is he doing right well you can + + + align:start position:0% +what is he doing right well you can +solve for the transformation temperature + + align:start position:0% +solve for the transformation temperature + + + align:start position:0% +solve for the transformation temperature +from Delta X and Delta h + + align:start position:0% +from Delta X and Delta h + + + align:start position:0% +from Delta X and Delta h +under the condition of the Delta G of + + align:start position:0% +under the condition of the Delta G of + + + align:start position:0% +under the condition of the Delta G of +zero + + align:start position:0% +zero + + + align:start position:0% +zero +now I don't know if that answers your + + align:start position:0% +now I don't know if that answers your + + + align:start position:0% +now I don't know if that answers your +question + + align:start position:0% +question + + + align:start position:0% +question +um if it's off page please try again + + align:start position:0% +um if it's off page please try again + + + align:start position:0% +um if it's off page please try again +no that was helpful thank you + + align:start position:0% +no that was helpful thank you + + + align:start position:0% +no that was helpful thank you +thank you all right so um + + align:start position:0% +thank you all right so um + + + align:start position:0% +thank you all right so um +let's move on right so let's use the + + align:start position:0% +let's move on right so let's use the + + + align:start position:0% +let's move on right so let's use the +kind of calcium equation + + align:start position:0% + + + + align:start position:0% + +using + + align:start position:0% +using + + + align:start position:0% +using +the c c + + align:start position:0% +the c c + + + align:start position:0% +the c c +equation + + align:start position:0% +equation + + + align:start position:0% +equation +vapor pressure + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so this is a very useful case + + align:start position:0% +so this is a very useful case + + + align:start position:0% +so this is a very useful case +and let's just remember what what we're + + align:start position:0% +and let's just remember what what we're + + + align:start position:0% +and let's just remember what what we're +doing here + + align:start position:0% + + + + align:start position:0% + +right here is + + align:start position:0% +right here is + + + align:start position:0% +right here is +I have temperature here I have pressure + + align:start position:0% +I have temperature here I have pressure + + + align:start position:0% +I have temperature here I have pressure +here that's a typical way that vapor + + align:start position:0% +here that's a typical way that vapor + + + align:start position:0% +here that's a typical way that vapor +pressure curves are plotted + + align:start position:0% +pressure curves are plotted + + + align:start position:0% +pressure curves are plotted +and there's a typical curve and here's + + align:start position:0% +and there's a typical curve and here's + + + align:start position:0% +and there's a typical curve and here's +um solid + + align:start position:0% + + + + align:start position:0% + +for instance + + align:start position:0% +for instance + + + align:start position:0% +for instance +and here is vapor + + align:start position:0% +and here is vapor + + + align:start position:0% +and here is vapor +I use green for both that's not very + + align:start position:0% +I use green for both that's not very + + + align:start position:0% +I use green for both that's not very +creative + + align:start position:0% +creative + + + align:start position:0% +creative +um + + align:start position:0% +um + + + align:start position:0% +um +let me point out that everything we're + + align:start position:0% +let me point out that everything we're + + + align:start position:0% +let me point out that everything we're +about to do + + align:start position:0% + + + + align:start position:0% + +also applies if that's liquid + + align:start position:0% +also applies if that's liquid + + + align:start position:0% +also applies if that's liquid +so it's vapor pressure over a condensed + + align:start position:0% +so it's vapor pressure over a condensed + + + align:start position:0% +so it's vapor pressure over a condensed +phase it doesn't have to be over the + + align:start position:0% +phase it doesn't have to be over the + + + align:start position:0% +phase it doesn't have to be over the +solid phase it could also be over liquid + + align:start position:0% +solid phase it could also be over liquid + + + align:start position:0% +solid phase it could also be over liquid +so here + + align:start position:0% +so here + + + align:start position:0% +so here +vapor + + align:start position:0% +vapor + + + align:start position:0% +vapor +condenses + + align:start position:0% + + + + align:start position:0% + +right on that side of the curve vapor + + align:start position:0% +right on that side of the curve vapor + + + align:start position:0% +right on that side of the curve vapor +condenses + + align:start position:0% +condenses + + + align:start position:0% +condenses +and here + + align:start position:0% +and here + + + align:start position:0% +and here +solid + + align:start position:0% +solid + + + align:start position:0% +solid +sublimes + + align:start position:0% + + + + align:start position:0% + +or liquid evaporates as the case may be + + align:start position:0% + + + + align:start position:0% + +right so that's the meaning of this + + align:start position:0% +right so that's the meaning of this + + + align:start position:0% +right so that's the meaning of this +phase diagram + + align:start position:0% +phase diagram + + + align:start position:0% +phase diagram +um + + align:start position:0% +um + + + align:start position:0% +um +Okay so + + align:start position:0% +Okay so + + + align:start position:0% +Okay so +on the coexistence line + + align:start position:0% + + + + align:start position:0% + +on the coexistence line + + align:start position:0% +on the coexistence line + + + align:start position:0% +on the coexistence line +vapor + + align:start position:0% + + + + align:start position:0% + +saturated that's an important word + + align:start position:0% + + + + align:start position:0% + +you need to be able to interpret that + + align:start position:0% +you need to be able to interpret that + + + align:start position:0% +you need to be able to interpret that +word when you see it in all sorts of + + align:start position:0% +word when you see it in all sorts of + + + align:start position:0% +word when you see it in all sorts of +problems + + align:start position:0% +problems + + + align:start position:0% +problems +saturated + + align:start position:0% +saturated + + + align:start position:0% +saturated +that's a really important concept + + align:start position:0% +that's a really important concept + + + align:start position:0% +that's a really important concept +at + + align:start position:0% +at + + + align:start position:0% +at +saturation vapor pressure + + align:start position:0% +saturation vapor pressure + + + align:start position:0% +saturation vapor pressure +so these terms saturation saturation + + align:start position:0% +so these terms saturation saturation + + + align:start position:0% +so these terms saturation saturation +vapor pressure you're going to encounter + + align:start position:0% +vapor pressure you're going to encounter + + + align:start position:0% +vapor pressure you're going to encounter +these all over the place + + align:start position:0% +these all over the place + + + align:start position:0% +these all over the place +um even on your even on your weather + + align:start position:0% +um even on your even on your weather + + + align:start position:0% +um even on your even on your weather +forecast + + align:start position:0% +forecast + + + align:start position:0% +forecast +and it's nice to be able to connect it + + align:start position:0% +and it's nice to be able to connect it + + + align:start position:0% +and it's nice to be able to connect it +back to the thermodynamics Okay so + + align:start position:0% + + + + align:start position:0% + +we're on the curve let's say + + align:start position:0% +we're on the curve let's say + + + align:start position:0% +we're on the curve let's say +if + + align:start position:0% +if + + + align:start position:0% +if +excess + + align:start position:0% + + + + align:start position:0% + +vapor pressure + + align:start position:0% + + + + align:start position:0% + +is added + + align:start position:0% + + + + align:start position:0% + +what will happen imagine you have a + + align:start position:0% +what will happen imagine you have a + + + align:start position:0% +what will happen imagine you have a +system you have these two phases in a + + align:start position:0% +system you have these two phases in a + + + align:start position:0% +system you have these two phases in a +box + + align:start position:0% +box + + + align:start position:0% +box +and you turn up the vapor pressure + + align:start position:0% +and you turn up the vapor pressure + + + align:start position:0% +and you turn up the vapor pressure +what will spontaneously happen + + align:start position:0% + + + + align:start position:0% + +The Vapor will condense to decrease + + align:start position:0% +The Vapor will condense to decrease + + + align:start position:0% +The Vapor will condense to decrease +thank you will spontaneously + + align:start position:0% + + + + align:start position:0% + +condense + + align:start position:0% + + + + align:start position:0% + +to let me put this in quotes + + align:start position:0% +to let me put this in quotes + + + align:start position:0% +to let me put this in quotes +to try to + + align:start position:0% +to try to + + + align:start position:0% +to try to +reapproach + + align:start position:0% + + + + align:start position:0% + +right to try to reapproach PSAT likewise + + align:start position:0% +right to try to reapproach PSAT likewise + + + align:start position:0% +right to try to reapproach PSAT likewise +if vapor pressure + + align:start position:0% +if vapor pressure + + + align:start position:0% +if vapor pressure +is reduced let's say you hook it up to a + + align:start position:0% +is reduced let's say you hook it up to a + + + align:start position:0% +is reduced let's say you hook it up to a +vacuum pump + + align:start position:0% + + + + align:start position:0% + +what will happen + + align:start position:0% + + + + align:start position:0% + +solid will thank you I'm going to use a + + align:start position:0% +solid will thank you I'm going to use a + + + align:start position:0% +solid will thank you I'm going to use a +case of the solid but you're right + + align:start position:0% +case of the solid but you're right + + + align:start position:0% +case of the solid but you're right +spontaneously + + align:start position:0% + + + + align:start position:0% + +Sublime + + align:start position:0% + + + + align:start position:0% + +to again in air quotes + + align:start position:0% +to again in air quotes + + + align:start position:0% +to again in air quotes +try to + + align:start position:0% +try to + + + align:start position:0% +try to +reapproach + + align:start position:0% + + + + align:start position:0% + +saturation vapor pressure + + align:start position:0% +saturation vapor pressure + + + align:start position:0% +saturation vapor pressure +okay so it seems that when you're on + + align:start position:0% +okay so it seems that when you're on + + + align:start position:0% +okay so it seems that when you're on +this coexistence line + + align:start position:0% +this coexistence line + + + align:start position:0% +this coexistence line +if you try to change the Intensive + + align:start position:0% +if you try to change the Intensive + + + align:start position:0% +if you try to change the Intensive +parameters of the system + + align:start position:0% +parameters of the system + + + align:start position:0% +parameters of the system +if you try to change the pressure say + + align:start position:0% +if you try to change the pressure say + + + align:start position:0% +if you try to change the pressure say +um + + align:start position:0% +um + + + align:start position:0% +um +the system will respond to try to + + align:start position:0% +the system will respond to try to + + + align:start position:0% +the system will respond to try to +counteract your change it will try to + + align:start position:0% +counteract your change it will try to + + + align:start position:0% +counteract your change it will try to +resist whatever you're trying to do if + + align:start position:0% +resist whatever you're trying to do if + + + align:start position:0% +resist whatever you're trying to do if +you try to increase the pressure it's + + align:start position:0% +you try to increase the pressure it's + + + align:start position:0% +you try to increase the pressure it's +got a way to try to + + align:start position:0% +got a way to try to + + + align:start position:0% +got a way to try to +pull it back down if you try to decrease + + align:start position:0% +pull it back down if you try to decrease + + + align:start position:0% +pull it back down if you try to decrease +the pressure it's got a way to try to + + align:start position:0% +the pressure it's got a way to try to + + + align:start position:0% +the pressure it's got a way to try to +push it back up + + align:start position:0% +push it back up + + + align:start position:0% +push it back up +right so it has a way to resist you + + align:start position:0% +right so it has a way to resist you + + + align:start position:0% +right so it has a way to resist you +what's the principle behind that and + + align:start position:0% +what's the principle behind that and + + + align:start position:0% +what's the principle behind that and +it's a french guy who remembers there's + + align:start position:0% +it's a french guy who remembers there's + + + align:start position:0% +it's a french guy who remembers there's +a general principle which explains this + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% + + + + align:start position:0% + +this is a really nice example of the + + align:start position:0% +this is a really nice example of the + + + align:start position:0% +this is a really nice example of the +shot to the ace principle + + align:start position:0% +shot to the ace principle + + + align:start position:0% +shot to the ace principle +that is nature reacts in such a way to + + align:start position:0% +that is nature reacts in such a way to + + + align:start position:0% +that is nature reacts in such a way to +counteract any external impulses + + align:start position:0% +counteract any external impulses + + + align:start position:0% +counteract any external impulses +or in other words it's stubborn it will + + align:start position:0% +or in other words it's stubborn it will + + + align:start position:0% +or in other words it's stubborn it will +resist you by any means possible so in + + align:start position:0% +resist you by any means possible so in + + + align:start position:0% +resist you by any means possible so in +this case you're on the coexistence line + + align:start position:0% +this case you're on the coexistence line + + + align:start position:0% +this case you're on the coexistence line +it has a means of resistance which is + + align:start position:0% +it has a means of resistance which is + + + align:start position:0% +it has a means of resistance which is +this phase transformation and it will + + align:start position:0% +this phase transformation and it will + + + align:start position:0% +this phase transformation and it will +use that phase transformation to try to + + align:start position:0% +use that phase transformation to try to + + + align:start position:0% +use that phase transformation to try to +resist the changes which you impose + + align:start position:0% +resist the changes which you impose + + + align:start position:0% +resist the changes which you impose +all right so I hope that's a little bit + + align:start position:0% +all right so I hope that's a little bit + + + align:start position:0% +all right so I hope that's a little bit +intuitive + + align:start position:0% + + + + align:start position:0% + +let's do some math around that + + align:start position:0% +let's do some math around that + + + align:start position:0% +let's do some math around that +all right so let's calculate + + align:start position:0% + + + + align:start position:0% + +let's calculate the calculation the + + align:start position:0% +let's calculate the calculation the + + + align:start position:0% +let's calculate the calculation the +saturation vapor pressure + + align:start position:0% +saturation vapor pressure + + + align:start position:0% +saturation vapor pressure +how do we do that we have a a + + align:start position:0% +how do we do that we have a a + + + align:start position:0% +how do we do that we have a a +differential equation right + + align:start position:0% +differential equation right + + + align:start position:0% +differential equation right +so how do we get an equation from a + + align:start position:0% +so how do we get an equation from a + + + align:start position:0% +so how do we get an equation from a +differential equation + + align:start position:0% + + + + align:start position:0% + +right you have to solve it + + align:start position:0% +right you have to solve it + + + align:start position:0% +right you have to solve it +so we're going to do it by integrating + + align:start position:0% +so we're going to do it by integrating + + + align:start position:0% +so we're going to do it by integrating +the CC equation + + align:start position:0% +the CC equation + + + align:start position:0% +the CC equation +and as we'll see uh normally uh in + + align:start position:0% +and as we'll see uh normally uh in + + + align:start position:0% +and as we'll see uh normally uh in +general you can't do this + + align:start position:0% +general you can't do this + + + align:start position:0% +general you can't do this +because it can't you might not have + + align:start position:0% +because it can't you might not have + + + align:start position:0% +because it can't you might not have +closed form expressions for everything + + align:start position:0% +closed form expressions for everything + + + align:start position:0% +closed form expressions for everything +that you need but we're going to make + + align:start position:0% +that you need but we're going to make + + + align:start position:0% +that you need but we're going to make +some approximations + + align:start position:0% +some approximations + + + align:start position:0% +some approximations +so here's in general we have this DP + + align:start position:0% +so here's in general we have this DP + + + align:start position:0% +so here's in general we have this DP +Delta V + + align:start position:0% +Delta V + + + align:start position:0% +Delta V +equals DT + + align:start position:0% +equals DT + + + align:start position:0% +equals DT +Delta H over T right if we're going to + + align:start position:0% +Delta H over T right if we're going to + + + align:start position:0% +Delta H over T right if we're going to +integral integrate this thing in general + + align:start position:0% +integral integrate this thing in general + + + align:start position:0% +integral integrate this thing in general +we need + + align:start position:0% +we need + + + align:start position:0% +we need +what we need Delta H as a function of T + + align:start position:0% +what we need Delta H as a function of T + + + align:start position:0% +what we need Delta H as a function of T +and P and we need Delta v as a function + + align:start position:0% +and P and we need Delta v as a function + + + align:start position:0% +and P and we need Delta v as a function +of T and P right in general we're going + + align:start position:0% +of T and P right in general we're going + + + align:start position:0% +of T and P right in general we're going +to need these things and we have no even + + align:start position:0% +to need these things and we have no even + + + align:start position:0% +to need these things and we have no even +if these equations of State exist + + align:start position:0% +if these equations of State exist + + + align:start position:0% +if these equations of State exist +there's no guarantee that they're + + align:start position:0% +there's no guarantee that they're + + + align:start position:0% +there's no guarantee that they're +separable or that we know how to solve + + align:start position:0% +separable or that we know how to solve + + + align:start position:0% +separable or that we know how to solve +the equation + + align:start position:0% +the equation + + + align:start position:0% +the equation +um right this is why we use + + align:start position:0% +um right this is why we use + + + align:start position:0% +um right this is why we use +computers + + align:start position:0% +computers + + + align:start position:0% +computers +so in in general + + align:start position:0% + + + + align:start position:0% + +these transformation + + align:start position:0% + + + + align:start position:0% + +quantities + + align:start position:0% + + + + align:start position:0% + +can be + + align:start position:0% + + + + align:start position:0% + +right as we saw last time + + align:start position:0% +right as we saw last time + + + align:start position:0% +right as we saw last time +in general + + align:start position:0% +in general + + + align:start position:0% +in general +let's say this is pressure + + align:start position:0% + + + + align:start position:0% + +this is temperature + + align:start position:0% +this is temperature + + + align:start position:0% +this is temperature +let's say there's + + align:start position:0% +let's say there's + + + align:start position:0% +let's say there's +a standard + + align:start position:0% +a standard + + + align:start position:0% +a standard +t-not peanut + + align:start position:0% +t-not peanut + + + align:start position:0% +t-not peanut +like standard temperature and pressure + + align:start position:0% +like standard temperature and pressure + + + align:start position:0% +like standard temperature and pressure +conditions right + + align:start position:0% +conditions right + + + align:start position:0% +conditions right +standard state + + align:start position:0% + + + + align:start position:0% + +and someone gives us the transformation + + align:start position:0% +and someone gives us the transformation + + + align:start position:0% +and someone gives us the transformation +quantities there + + align:start position:0% +quantities there + + + align:start position:0% +quantities there +right and we actually need them over + + align:start position:0% +right and we actually need them over + + + align:start position:0% +right and we actually need them over +here + + align:start position:0% + + + + align:start position:0% + +right at some other p + + align:start position:0% +right at some other p + + + align:start position:0% +right at some other p +and T + + align:start position:0% + + + + align:start position:0% + +right so in general in general we can + + align:start position:0% +right so in general in general we can + + + align:start position:0% +right so in general in general we can +integrate so for instance + + align:start position:0% + + + + align:start position:0% + +calculating Delta H as a function of t + + align:start position:0% +calculating Delta H as a function of t + + + align:start position:0% +calculating Delta H as a function of t +and P + + align:start position:0% +and P + + + align:start position:0% +and P +like DH equals c p d t minus plus v one + + align:start position:0% +like DH equals c p d t minus plus v one + + + align:start position:0% +like DH equals c p d t minus plus v one +minus t Alpha + + align:start position:0% +minus t Alpha + + + align:start position:0% +minus t Alpha +DP + + align:start position:0% +DP + + + align:start position:0% +DP +so it's Delta H at T and P + + align:start position:0% +so it's Delta H at T and P + + + align:start position:0% +so it's Delta H at T and P +equals Delta h + + align:start position:0% +equals Delta h + + + align:start position:0% +equals Delta h +x a t naught and P naught some standard + + align:start position:0% +x a t naught and P naught some standard + + + align:start position:0% +x a t naught and P naught some standard +data which I found maybe in a database + + align:start position:0% +data which I found maybe in a database + + + align:start position:0% +data which I found maybe in a database +plus from T naught to T + + align:start position:0% +plus from T naught to T + + + align:start position:0% +plus from T naught to T +d + + align:start position:0% +d + + + align:start position:0% +d +Delta h + + align:start position:0% +Delta h + + + align:start position:0% +Delta h +and fixed pressure + + align:start position:0% +and fixed pressure + + + align:start position:0% +and fixed pressure +Plus + + align:start position:0% +Plus + + + align:start position:0% +Plus +from P naught to p + + align:start position:0% +from P naught to p + + + align:start position:0% +from P naught to p +d + + align:start position:0% +d + + + align:start position:0% +d +Delta H at fixed temperature + + align:start position:0% + + + + align:start position:0% + +which equals Delta h + + align:start position:0% +which equals Delta h + + + align:start position:0% +which equals Delta h +T naught T naught Plus + + align:start position:0% +T naught T naught Plus + + + align:start position:0% +T naught T naught Plus +T naught over t + + align:start position:0% +T naught over t + + + align:start position:0% +T naught over t +d t Prime dummy variable Delta CP so + + align:start position:0% +d t Prime dummy variable Delta CP so + + + align:start position:0% +d t Prime dummy variable Delta CP so +there's my heat capacity differences + + align:start position:0% +there's my heat capacity differences + + + align:start position:0% +there's my heat capacity differences +right so here's where that data comes in + + align:start position:0% +right so here's where that data comes in + + + align:start position:0% +right so here's where that data comes in +P naught to p d + + align:start position:0% +P naught to p d + + + align:start position:0% +P naught to p d +P Prime dummy variable + + align:start position:0% +P Prime dummy variable + + + align:start position:0% +P Prime dummy variable +and again a transformation quantity V + + align:start position:0% +and again a transformation quantity V + + + align:start position:0% +and again a transformation quantity V +one minus t Alpha + + align:start position:0% + + + + align:start position:0% + +these are + + align:start position:0% + + + + align:start position:0% + +transformation quantities + + align:start position:0% + + + + align:start position:0% + +all right these characterize the change + + align:start position:0% +all right these characterize the change + + + align:start position:0% +all right these characterize the change +as you move between phases + + align:start position:0% +as you move between phases + + + align:start position:0% +as you move between phases +all right so I'm just I'm just laying + + align:start position:0% +all right so I'm just I'm just laying + + + align:start position:0% +all right so I'm just I'm just laying +this out in general you're very rare + + align:start position:0% +this out in general you're very rare + + + align:start position:0% +this out in general you're very rare +that you actually have to do + + align:start position:0% +that you actually have to do + + + align:start position:0% +that you actually have to do +calculations like this let me lay out + + align:start position:0% +calculations like this let me lay out + + + align:start position:0% +calculations like this let me lay out +how to calculate Delta V + + align:start position:0% + + + + align:start position:0% + +calculating Delta V right that's the + + align:start position:0% +calculating Delta V right that's the + + + align:start position:0% +calculating Delta V right that's the +other part of the integral Delta V so we + + align:start position:0% +other part of the integral Delta V so we + + + align:start position:0% +other part of the integral Delta V so we +have DV equals V Alpha DT minus V beta + + align:start position:0% +have DV equals V Alpha DT minus V beta + + + align:start position:0% +have DV equals V Alpha DT minus V beta +DP that's the general form + + align:start position:0% +DP that's the general form + + + align:start position:0% +DP that's the general form +so Delta V + + align:start position:0% +so Delta V + + + align:start position:0% +so Delta V +at some temperature and pressure + + align:start position:0% +at some temperature and pressure + + + align:start position:0% +at some temperature and pressure +equals Delta V + + align:start position:0% +equals Delta V + + + align:start position:0% +equals Delta V +at a standard temperature and pressure + + align:start position:0% +at a standard temperature and pressure + + + align:start position:0% +at a standard temperature and pressure +Plus + + align:start position:0% +Plus + + + align:start position:0% +Plus +from standard temperature to my desired + + align:start position:0% +from standard temperature to my desired + + + align:start position:0% +from standard temperature to my desired +temperature D Delta V at fixed pressure + + align:start position:0% +temperature D Delta V at fixed pressure + + + align:start position:0% +temperature D Delta V at fixed pressure +plus from standard pressure to my + + align:start position:0% +plus from standard pressure to my + + + align:start position:0% +plus from standard pressure to my +pressure of Interest D Delta V at a + + align:start position:0% +pressure of Interest D Delta V at a + + + align:start position:0% +pressure of Interest D Delta V at a +fixed temperature + + align:start position:0% + + + + align:start position:0% + +equals Delta V + + align:start position:0% +equals Delta V + + + align:start position:0% +equals Delta V +at T naught P naught Plus + + align:start position:0% +at T naught P naught Plus + + + align:start position:0% +at T naught P naught Plus +T naught t + + align:start position:0% +T naught t + + + align:start position:0% +T naught t +D dummy variable + + align:start position:0% +D dummy variable + + + align:start position:0% +D dummy variable +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +V Alpha + + align:start position:0% + + + + align:start position:0% + +Plus + + align:start position:0% +Plus + + + align:start position:0% +Plus +P naught to P dummy variable + + align:start position:0% +P naught to P dummy variable + + + align:start position:0% +P naught to P dummy variable +Delta minus V beta and again + + align:start position:0% + + + + align:start position:0% + +these are transformation quantities + + align:start position:0% +these are transformation quantities + + + align:start position:0% +these are transformation quantities +they're the differences + + align:start position:0% + + + + align:start position:0% + +between phases + + align:start position:0% +between phases + + + align:start position:0% +between phases +transformation quantities all right so + + align:start position:0% +transformation quantities all right so + + + align:start position:0% +transformation quantities all right so +um + + align:start position:0% +um + + + align:start position:0% +um +why am I telling you this right uh + + align:start position:0% +why am I telling you this right uh + + + align:start position:0% +why am I telling you this right uh +I can hear that go live from Hamilton in + + align:start position:0% +I can hear that go live from Hamilton in + + + align:start position:0% +I can hear that go live from Hamilton in +my background why am I telling you this + + align:start position:0% +my background why am I telling you this + + + align:start position:0% +my background why am I telling you this +I'm telling you this because in general + + align:start position:0% +I'm telling you this because in general + + + align:start position:0% +I'm telling you this because in general +you need a lot of data to do these + + align:start position:0% +you need a lot of data to do these + + + align:start position:0% +you need a lot of data to do these +calculations you need to know the heat + + align:start position:0% +calculations you need to know the heat + + + align:start position:0% +calculations you need to know the heat +capacities of all the phases and their + + align:start position:0% +capacities of all the phases and their + + + align:start position:0% +capacities of all the phases and their +differences you need to know that + + align:start position:0% +differences you need to know that + + + align:start position:0% +differences you need to know that +thermal expansion coefficients of all + + align:start position:0% +thermal expansion coefficients of all + + + align:start position:0% +thermal expansion coefficients of all +the phases and their differences + + align:start position:0% +the phases and their differences + + + align:start position:0% +the phases and their differences +for this calculation you need to tell + + align:start position:0% +for this calculation you need to tell + + + align:start position:0% +for this calculation you need to tell +the volume of all the phases + + align:start position:0% +the volume of all the phases + + + align:start position:0% +the volume of all the phases +and you know + + align:start position:0% +and you know + + + align:start position:0% +and you know +here right we are calculating Delta V's + + align:start position:0% +here right we are calculating Delta V's + + + align:start position:0% +here right we are calculating Delta V's +you need to know the volume of all the + + align:start position:0% +you need to know the volume of all the + + + align:start position:0% +you need to know the volume of all the +phases + + align:start position:0% +phases + + + align:start position:0% +phases +right + + align:start position:0% +right + + + align:start position:0% +right +and if you don't know the volume of all + + align:start position:0% +and if you don't know the volume of all + + + align:start position:0% +and if you don't know the volume of all +the faces at all temperature and + + align:start position:0% +the faces at all temperature and + + + align:start position:0% +the faces at all temperature and +pressure you have to know it at some + + align:start position:0% +pressure you have to know it at some + + + align:start position:0% +pressure you have to know it at some +temperature and pressure then you need + + align:start position:0% +temperature and pressure then you need + + + align:start position:0% +temperature and pressure then you need +the thermal expansion coefficient of all + + align:start position:0% +the thermal expansion coefficient of all + + + align:start position:0% +the thermal expansion coefficient of all +the phases and you need the isothermal + + align:start position:0% +the phases and you need the isothermal + + + align:start position:0% +the phases and you need the isothermal +compressibility of other phases all + + align:start position:0% +compressibility of other phases all + + + align:start position:0% +compressibility of other phases all +right so again you can see why calcater + + align:start position:0% +right so again you can see why calcater + + + align:start position:0% +right so again you can see why calcater +computer you know calculation phase + + align:start position:0% +computer you know calculation phase + + + align:start position:0% +computer you know calculation phase +diagrams is so powerful because it + + align:start position:0% +diagrams is so powerful because it + + + align:start position:0% +diagrams is so powerful because it +integrates all this stuff for you + + align:start position:0% +integrates all this stuff for you + + + align:start position:0% +integrates all this stuff for you +automatically right + + align:start position:0% +automatically right + + + align:start position:0% +automatically right +so in general + + align:start position:0% + + + + align:start position:0% + +in general this requires + + align:start position:0% + + + + align:start position:0% + +knowing some writing's getting sloppy + + align:start position:0% +knowing some writing's getting sloppy + + + align:start position:0% +knowing some writing's getting sloppy +here this requires knowing + + align:start position:0% +here this requires knowing + + + align:start position:0% +here this requires knowing +CP as a function of temperature and + + align:start position:0% +CP as a function of temperature and + + + align:start position:0% +CP as a function of temperature and +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +v as a function of temperature and + + align:start position:0% +v as a function of temperature and + + + align:start position:0% +v as a function of temperature and +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +Alpha as a function of temperature and + + align:start position:0% +Alpha as a function of temperature and + + + align:start position:0% +Alpha as a function of temperature and +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +and beta as a function of temperature + + align:start position:0% +and beta as a function of temperature + + + align:start position:0% +and beta as a function of temperature +and pressure + + align:start position:0% +and pressure + + + align:start position:0% +and pressure +for both phases + + align:start position:0% + + + + align:start position:0% + +so let's get phase labels here right + + align:start position:0% +so let's get phase labels here right + + + align:start position:0% +so let's get phase labels here right +there's a lot of information that we + + align:start position:0% +there's a lot of information that we + + + align:start position:0% +there's a lot of information that we +need to tabulate for both phases Kappa + + align:start position:0% +need to tabulate for both phases Kappa + + + align:start position:0% +need to tabulate for both phases Kappa +equals a of fan beta right + + align:start position:0% +equals a of fan beta right + + + align:start position:0% +equals a of fan beta right +however + + align:start position:0% + + + + align:start position:0% + +for + + align:start position:0% +for + + + align:start position:0% +for +vaporization + + align:start position:0% + + + + align:start position:0% + +of a condensed phase + + align:start position:0% + + + + align:start position:0% + +for vaporization of a condensed phase + + align:start position:0% +for vaporization of a condensed phase + + + align:start position:0% +for vaporization of a condensed phase +over + + align:start position:0% +over + + + align:start position:0% +over +a limited temperature range + + align:start position:0% + + + + align:start position:0% + +we can simplify + + align:start position:0% + + + + align:start position:0% + +using three assumptions + + align:start position:0% + + + + align:start position:0% + +one + + align:start position:0% +one + + + align:start position:0% +one +we're going to say Delta H is + + align:start position:0% +we're going to say Delta H is + + + align:start position:0% +we're going to say Delta H is +approximately equal + + align:start position:0% +approximately equal + + + align:start position:0% +approximately equal +to a constant + + align:start position:0% + + + + align:start position:0% + +that's probably the worst approximation + + align:start position:0% +that's probably the worst approximation + + + align:start position:0% +that's probably the worst approximation +we don't know if it's good or not we're + + align:start position:0% +we don't know if it's good or not we're + + + align:start position:0% +we don't know if it's good or not we're +just going to go with it + + align:start position:0% +just going to go with it + + + align:start position:0% +just going to go with it +if Delta H is a constant I don't need to + + align:start position:0% +if Delta H is a constant I don't need to + + + align:start position:0% +if Delta H is a constant I don't need to +do all that heat capacity integrating + + align:start position:0% +do all that heat capacity integrating + + + align:start position:0% +do all that heat capacity integrating +and so forth right it's just a number + + align:start position:0% +and so forth right it's just a number + + + align:start position:0% +and so forth right it's just a number +okay + + align:start position:0% +okay + + + align:start position:0% +okay +two + + align:start position:0% +two + + + align:start position:0% +two +volume of the gas is going to be much + + align:start position:0% +volume of the gas is going to be much + + + align:start position:0% +volume of the gas is going to be much +much greater than volume of the solid or + + align:start position:0% +much greater than volume of the solid or + + + align:start position:0% +much greater than volume of the solid or +volume of the liquid + + align:start position:0% +volume of the liquid + + + align:start position:0% +volume of the liquid +right if I assume the volume of the gas + + align:start position:0% +right if I assume the volume of the gas + + + align:start position:0% +right if I assume the volume of the gas +molar volume is much much greater than + + align:start position:0% +molar volume is much much greater than + + + align:start position:0% +molar volume is much much greater than +the solid of the liquid + + align:start position:0% +the solid of the liquid + + + align:start position:0% +the solid of the liquid +then Delta volume + + align:start position:0% + + + + align:start position:0% + +is approximately equal to what + + align:start position:0% + + + + align:start position:0% + +Delta volume this is a transformation + + align:start position:0% +Delta volume this is a transformation + + + align:start position:0% +Delta volume this is a transformation +quantity + + align:start position:0% +quantity + + + align:start position:0% +quantity +I am vaporizing + + align:start position:0% +I am vaporizing + + + align:start position:0% +I am vaporizing +so + + align:start position:0% +so + + + align:start position:0% +so +Delta volume is approximately equal to + + align:start position:0% +Delta volume is approximately equal to + + + align:start position:0% +Delta volume is approximately equal to +what + + align:start position:0% +what + + + align:start position:0% +what +the volume of the gas right exactly + + align:start position:0% +the volume of the gas right exactly + + + align:start position:0% +the volume of the gas right exactly +right Delta Delta V equals volume gas + + align:start position:0% +right Delta Delta V equals volume gas + + + align:start position:0% +right Delta Delta V equals volume gas +minus volume solid + + align:start position:0% +minus volume solid + + + align:start position:0% +minus volume solid +right and if the volume of gas is so + + align:start position:0% +right and if the volume of gas is so + + + align:start position:0% +right and if the volume of gas is so +much bigger + + align:start position:0% +much bigger + + + align:start position:0% +much bigger +uh right + + align:start position:0% + + + + align:start position:0% + +we can say it's basically equal to the + + align:start position:0% +we can say it's basically equal to the + + + align:start position:0% +we can say it's basically equal to the +volume of the vapor in and um you know + + align:start position:0% +volume of the vapor in and um you know + + + align:start position:0% +volume of the vapor in and um you know +the + + align:start position:0% +the + + + align:start position:0% +the +when when typical condensed phases + + align:start position:0% +when when typical condensed phases + + + align:start position:0% +when when typical condensed phases +sublime or evaporate you have factors of + + align:start position:0% +sublime or evaporate you have factors of + + + align:start position:0% +sublime or evaporate you have factors of +20 000 or more increase in volume molar + + align:start position:0% +20 000 or more increase in volume molar + + + align:start position:0% +20 000 or more increase in volume molar +volume + + align:start position:0% +volume + + + align:start position:0% +volume +so you know that means you're making an + + align:start position:0% +so you know that means you're making an + + + align:start position:0% +so you know that means you're making an +error one part and twenty thousand it's + + align:start position:0% +error one part and twenty thousand it's + + + align:start position:0% +error one part and twenty thousand it's +it's a pretty good approximation so that + + align:start position:0% +it's a pretty good approximation so that + + + align:start position:0% +it's a pretty good approximation so that +would say that that this is um + + align:start position:0% +would say that that this is um + + + align:start position:0% +would say that that this is um +this is a good approximation + + align:start position:0% + + + + align:start position:0% + +this one here is kind of a approximation + + align:start position:0% +this one here is kind of a approximation + + + align:start position:0% +this one here is kind of a approximation +it's okay it's not bad + + align:start position:0% +it's okay it's not bad + + + align:start position:0% +it's okay it's not bad +and here's + + align:start position:0% +and here's + + + align:start position:0% +and here's +the third approximation is that the gas + + align:start position:0% +the third approximation is that the gas + + + align:start position:0% +the third approximation is that the gas +the age ideally + + align:start position:0% + + + + align:start position:0% + +so we can use the ideal gas equation of + + align:start position:0% +so we can use the ideal gas equation of + + + align:start position:0% +so we can use the ideal gas equation of +state and unless you're at high + + align:start position:0% +state and unless you're at high + + + align:start position:0% +state and unless you're at high +pressures that's also a pretty good + + align:start position:0% +pressures that's also a pretty good + + + align:start position:0% +pressures that's also a pretty good +approximation + + align:start position:0% +approximation + + + align:start position:0% +approximation +so what we're going to see next is how + + align:start position:0% +so what we're going to see next is how + + + align:start position:0% +so what we're going to see next is how +these three approximations + + align:start position:0% +these three approximations + + + align:start position:0% +these three approximations +uh + + align:start position:0% +uh + + + align:start position:0% +uh +well + + align:start position:0% +well + + + align:start position:0% +well +what I'm going to do I'm just going to + + align:start position:0% +what I'm going to do I'm just going to + + + align:start position:0% +what I'm going to do I'm just going to +outline the the way that this goes + + align:start position:0% +outline the the way that this goes + + + align:start position:0% +outline the the way that this goes +forward because + + align:start position:0% +forward because + + + align:start position:0% +forward because +um for on the pset if you need to use + + align:start position:0% +um for on the pset if you need to use + + + align:start position:0% +um for on the pset if you need to use +this a little bit so I want you to + + align:start position:0% +this a little bit so I want you to + + + align:start position:0% +this a little bit so I want you to +explore a little bit + + align:start position:0% +explore a little bit + + + align:start position:0% +explore a little bit +but + + align:start position:0% +but + + + align:start position:0% +but +right if the volume of the gas + + align:start position:0% +right if the volume of the gas + + + align:start position:0% +right if the volume of the gas +equals RT + + align:start position:0% +equals RT + + + align:start position:0% +equals RT +over p + + align:start position:0% +over p + + + align:start position:0% +over p +right that's PV equals nrt + + align:start position:0% + + + + align:start position:0% + +and that's approximately equal to Delta + + align:start position:0% +and that's approximately equal to Delta + + + align:start position:0% +and that's approximately equal to Delta +V + + align:start position:0% +V + + + align:start position:0% +V +and Delta H is constant + + align:start position:0% + + + + align:start position:0% + +right let's remember what I'm trying to + + align:start position:0% +right let's remember what I'm trying to + + + align:start position:0% +right let's remember what I'm trying to +do here + + align:start position:0% + + + + align:start position:0% + +right here I have DP + + align:start position:0% +right here I have DP + + + align:start position:0% +right here I have DP +Delta V equals z t Del's H over K so + + align:start position:0% +Delta V equals z t Del's H over K so + + + align:start position:0% +Delta V equals z t Del's H over K so +let's see + + align:start position:0% +let's see + + + align:start position:0% +let's see +DP + + align:start position:0% +DP + + + align:start position:0% +DP +Delta V equals + + align:start position:0% +Delta V equals + + + align:start position:0% +Delta V equals +DT Delta h + + align:start position:0% +DT Delta h + + + align:start position:0% +DT Delta h +over t + + align:start position:0% +over t + + + align:start position:0% +over t +right + + align:start position:0% +right + + + align:start position:0% +right +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and + + align:start position:0% +and + + + align:start position:0% +and +so what + + align:start position:0% +so what + + + align:start position:0% +so what +we have DP + + align:start position:0% +we have DP + + + align:start position:0% +we have DP +RT over p + + align:start position:0% + + + + align:start position:0% + +equals DT Delta H over t + + align:start position:0% +equals DT Delta H over t + + + align:start position:0% +equals DT Delta H over t +right so so this is a constant now the + + align:start position:0% +right so so this is a constant now the + + + align:start position:0% +right so so this is a constant now the +the H is a constant that's our + + align:start position:0% +the H is a constant that's our + + + align:start position:0% +the H is a constant that's our +approximation + + align:start position:0% +approximation + + + align:start position:0% +approximation +we have temperature + + align:start position:0% +we have temperature + + + align:start position:0% +we have temperature +and temperature so it's separable I can + + align:start position:0% +and temperature so it's separable I can + + + align:start position:0% +and temperature so it's separable I can +take this temperature over here + + align:start position:0% +take this temperature over here + + + align:start position:0% +take this temperature over here +right so I'm going to have DT over t + + align:start position:0% +right so I'm going to have DT over t + + + align:start position:0% +right so I'm going to have DT over t +squared on the right hand side where the + + align:start position:0% +squared on the right hand side where the + + + align:start position:0% +squared on the right hand side where the +constant factor and the left hand side + + align:start position:0% +constant factor and the left hand side + + + align:start position:0% +constant factor and the left hand side +I'm going to have DP over p + + align:start position:0% +I'm going to have DP over p + + + align:start position:0% +I'm going to have DP over p +with a constant Factor so this is this + + align:start position:0% +with a constant Factor so this is this + + + align:start position:0% +with a constant Factor so this is this +is now a separable and easy differential + + align:start position:0% +is now a separable and easy differential + + + align:start position:0% +is now a separable and easy differential +equation to solve + + align:start position:0% +equation to solve + + + align:start position:0% +equation to solve +and as you can see already you're going + + align:start position:0% +and as you can see already you're going + + + align:start position:0% +and as you can see already you're going +to get logarithms + + align:start position:0% +to get logarithms + + + align:start position:0% +to get logarithms +uh from from the DP over P term okay so + + align:start position:0% +uh from from the DP over P term okay so + + + align:start position:0% +uh from from the DP over P term okay so +um + + align:start position:0% +um + + + align:start position:0% +um +I'm going to leave it here for you to + + align:start position:0% +I'm going to leave it here for you to + + + align:start position:0% +I'm going to leave it here for you to +finish this calculation + + align:start position:0% +finish this calculation + + + align:start position:0% +finish this calculation +um and you'll use the result + + align:start position:0% +um and you'll use the result + + + align:start position:0% +um and you'll use the result +on the uh in the P set + + align:start position:0% +on the uh in the P set + + + align:start position:0% +on the uh in the P set +and this is very well described in the + + align:start position:0% +and this is very well described in the + + + align:start position:0% +and this is very well described in the +textbook so you can step through it's a + + align:start position:0% +textbook so you can step through it's a + + + align:start position:0% +textbook so you can step through it's a +nice calculation to finish + + align:start position:0% +nice calculation to finish + + + align:start position:0% +nice calculation to finish +um I'm going to move on to Gibbs phase + + align:start position:0% +um I'm going to move on to Gibbs phase + + + align:start position:0% +um I'm going to move on to Gibbs phase +rule so so we're going to leave this + + align:start position:0% +rule so so we're going to leave this + + + align:start position:0% +rule so so we're going to leave this +here on questions on saturation vapor + + align:start position:0% +here on questions on saturation vapor + + + align:start position:0% +here on questions on saturation vapor +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +um this is a good time for them I will + + align:start position:0% +um this is a good time for them I will + + + align:start position:0% +um this is a good time for them I will +note that we're going to return to the + + align:start position:0% +note that we're going to return to the + + + align:start position:0% +note that we're going to return to the +concept of saturation vapor pressure on + + align:start position:0% +concept of saturation vapor pressure on + + + align:start position:0% +concept of saturation vapor pressure on +Wednesday when we're going to do an + + align:start position:0% +Wednesday when we're going to do an + + + align:start position:0% +Wednesday when we're going to do an +extended example + + align:start position:0% +extended example + + + align:start position:0% +extended example +so this isn't the last you'll see + + align:start position:0% +so this isn't the last you'll see + + + align:start position:0% +so this isn't the last you'll see +saturation vapor pressure + + align:start position:0% +saturation vapor pressure + + + align:start position:0% +saturation vapor pressure +and we'll come back with a vengeance + + align:start position:0% +and we'll come back with a vengeance + + + align:start position:0% +and we'll come back with a vengeance +um in a couple weeks from now when we do + + align:start position:0% +um in a couple weeks from now when we do + + + align:start position:0% +um in a couple weeks from now when we do +uh + + align:start position:0% +uh + + + align:start position:0% +uh +multi-phase multi-component reacting + + align:start position:0% +multi-phase multi-component reacting + + + align:start position:0% +multi-phase multi-component reacting +systems + + align:start position:0% + + + + align:start position:0% + +well I do have a quick question so + + align:start position:0% +well I do have a quick question so + + + align:start position:0% +well I do have a quick question so +in order to assume like DP over DT + + align:start position:0% +in order to assume like DP over DT + + + align:start position:0% +in order to assume like DP over DT +equals Delta H over T Delta V we said + + align:start position:0% +equals Delta H over T Delta V we said + + + align:start position:0% +equals Delta H over T Delta V we said +that it had to be isothermal + + align:start position:0% +that it had to be isothermal + + + align:start position:0% +that it had to be isothermal +yes I did this was um I'm sorry you're + + align:start position:0% +yes I did this was um I'm sorry you're + + + align:start position:0% +yes I did this was um I'm sorry you're +referring back to Delta at the end of + + align:start position:0% +referring back to Delta at the end of + + + align:start position:0% +referring back to Delta at the end of +the cost of Delta H minus t Delta s + + align:start position:0% +the cost of Delta H minus t Delta s + + + align:start position:0% +the cost of Delta H minus t Delta s +yeah and then we said like when + + align:start position:0% +yeah and then we said like when + + + align:start position:0% +yeah and then we said like when +we wrote the second form of like the + + align:start position:0% +we wrote the second form of like the + + + align:start position:0% +we wrote the second form of like the +clausius cap clap around equation like + + align:start position:0% +clausius cap clap around equation like + + + align:start position:0% +clausius cap clap around equation like +that it had to be isothermal for that + + align:start position:0% +that it had to be isothermal for that + + + align:start position:0% +that it had to be isothermal for that +right so then why is DT not zero + + align:start position:0% + + + + align:start position:0% + +good question + + align:start position:0% +good question + + + align:start position:0% +good question +this is a consistent question of + + align:start position:0% +this is a consistent question of + + + align:start position:0% +this is a consistent question of +confusion + + align:start position:0% +confusion + + + align:start position:0% +confusion +um + + align:start position:0% +um + + + align:start position:0% +um +these and and again + + align:start position:0% +these and and again + + + align:start position:0% +these and and again +um I won't put you on the spot and ask + + align:start position:0% +um I won't put you on the spot and ask + + + align:start position:0% +um I won't put you on the spot and ask +you whether you've + + align:start position:0% +you whether you've + + + align:start position:0% +you whether you've +watched and spent time thinking about + + align:start position:0% +watched and spent time thinking about + + + align:start position:0% +watched and spent time thinking about +the 3DS of thermodynamics video I don't + + align:start position:0% +the 3DS of thermodynamics video I don't + + + align:start position:0% +the 3DS of thermodynamics video I don't +mean to for suggest upset a Panacea but + + align:start position:0% +mean to for suggest upset a Panacea but + + + align:start position:0% +mean to for suggest upset a Panacea but +um this is a very confusing point + + align:start position:0% +um this is a very confusing point + + + align:start position:0% +um this is a very confusing point +these are transformation quantities + + align:start position:0% +these are transformation quantities + + + align:start position:0% +these are transformation quantities +these are functions of temperature and + + align:start position:0% +these are functions of temperature and + + + align:start position:0% +these are functions of temperature and +pressure at any given temperature and + + align:start position:0% +pressure at any given temperature and + + + align:start position:0% +pressure at any given temperature and +pressure they're numbers + + align:start position:0% +pressure they're numbers + + + align:start position:0% +pressure they're numbers +so for instance Delta s Delta V Delta H + + align:start position:0% +so for instance Delta s Delta V Delta H + + + align:start position:0% +so for instance Delta s Delta V Delta H +Delta V and any given temperature and + + align:start position:0% +Delta V and any given temperature and + + + align:start position:0% +Delta V and any given temperature and +pressure they're numbers they + + align:start position:0% +pressure they're numbers they + + + align:start position:0% +pressure they're numbers they +characterize the change in state + + align:start position:0% +characterize the change in state + + + align:start position:0% +characterize the change in state +variables As you move between phases + + align:start position:0% + + + + align:start position:0% + +being functions of temperature and + + align:start position:0% +being functions of temperature and + + + align:start position:0% +being functions of temperature and +pressure they depend on temperature and + + align:start position:0% +pressure they depend on temperature and + + + align:start position:0% +pressure they depend on temperature and +pressure so I want you to think of these + + align:start position:0% +pressure so I want you to think of these + + + align:start position:0% +pressure so I want you to think of these +capital D Deltas as the distances + + align:start position:0% +capital D Deltas as the distances + + + align:start position:0% +capital D Deltas as the distances +between these surfaces and I'm sort of + + align:start position:0% +between these surfaces and I'm sort of + + + align:start position:0% +between these surfaces and I'm sort of +drawing surfaces here but it was I drew + + align:start position:0% +drawing surfaces here but it was I drew + + + align:start position:0% +drawing surfaces here but it was I drew +it in the last lecture and it's really + + align:start position:0% +it in the last lecture and it's really + + + align:start position:0% +it in the last lecture and it's really +well Illustrated in a textbook so each + + align:start position:0% +well Illustrated in a textbook so each + + + align:start position:0% +well Illustrated in a textbook so each +of these quantities Delta s Delta V is + + align:start position:0% +of these quantities Delta s Delta V is + + + align:start position:0% +of these quantities Delta s Delta V is +the distance between let's say the + + align:start position:0% +the distance between let's say the + + + align:start position:0% +the distance between let's say the +surface s for phase vapor and S for + + align:start position:0% +surface s for phase vapor and S for + + + align:start position:0% +surface s for phase vapor and S for +phase solid as as drawing the last + + align:start position:0% +phase solid as as drawing the last + + + align:start position:0% +phase solid as as drawing the last +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +um + + align:start position:0% + + + + align:start position:0% + +and since they're functions of + + align:start position:0% +and since they're functions of + + + align:start position:0% +and since they're functions of +temperature and pressure they vary with + + align:start position:0% +temperature and pressure they vary with + + + align:start position:0% +temperature and pressure they vary with +temperature and pressure + + align:start position:0% +temperature and pressure + + + align:start position:0% +temperature and pressure +so for example you have volume oh that's + + align:start position:0% +so for example you have volume oh that's + + + align:start position:0% +so for example you have volume oh that's +a really fat pen that's not helping + + align:start position:0% +a really fat pen that's not helping + + + align:start position:0% +a really fat pen that's not helping +let me find a page where I have some + + align:start position:0% +let me find a page where I have some + + + align:start position:0% +let me find a page where I have some +white space this there I have my space + + align:start position:0% +white space this there I have my space + + + align:start position:0% +white space this there I have my space +on this page + + align:start position:0% +on this page + + + align:start position:0% +on this page +let me grab a pen that's not too worn + + align:start position:0% +let me grab a pen that's not too worn + + + align:start position:0% +let me grab a pen that's not too worn +out yet so let's say I have + + align:start position:0% +out yet so let's say I have + + + align:start position:0% +out yet so let's say I have +volume of phase Alpha that of course + + align:start position:0% +volume of phase Alpha that of course + + + align:start position:0% +volume of phase Alpha that of course +depends on temperature and pressure + + align:start position:0% +depends on temperature and pressure + + + align:start position:0% +depends on temperature and pressure +volume of phase beta that of course + + align:start position:0% +volume of phase beta that of course + + + align:start position:0% +volume of phase beta that of course +depends on pressure and temperature + + align:start position:0% +depends on pressure and temperature + + + align:start position:0% +depends on pressure and temperature +and so I might have a transformation + + align:start position:0% +and so I might have a transformation + + + align:start position:0% +and so I might have a transformation +quantity the change in volume as I + + align:start position:0% +quantity the change in volume as I + + + align:start position:0% +quantity the change in volume as I +transform from alpha to Beta this equals + + align:start position:0% +transform from alpha to Beta this equals + + + align:start position:0% +transform from alpha to Beta this equals +volume of beta temperature and pressure + + align:start position:0% +volume of beta temperature and pressure + + + align:start position:0% +volume of beta temperature and pressure +minus volume of alpha temperature and + + align:start position:0% +minus volume of alpha temperature and + + + align:start position:0% +minus volume of alpha temperature and +pressure and so this explicitly depends + + align:start position:0% +pressure and so this explicitly depends + + + align:start position:0% +pressure and so this explicitly depends +on temperature and pressure + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +um + + align:start position:0% +um + + + align:start position:0% +um +right that means that even though I can + + align:start position:0% +right that means that even though I can + + + align:start position:0% +right that means that even though I can +consider an isothermal transformation + + align:start position:0% +consider an isothermal transformation + + + align:start position:0% +consider an isothermal transformation +between Alpha and beta I can also ask + + align:start position:0% +between Alpha and beta I can also ask + + + align:start position:0% +between Alpha and beta I can also ask +how that quantity varies + + align:start position:0% + + + + align:start position:0% + +let's say with temperature + + align:start position:0% + + + + align:start position:0% + +right that's the slope of that surface + + align:start position:0% +right that's the slope of that surface + + + align:start position:0% +right that's the slope of that surface +for varying temperature with fixed + + align:start position:0% +for varying temperature with fixed + + + align:start position:0% +for varying temperature with fixed +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +and and I'm hesitating to launch into + + align:start position:0% +and and I'm hesitating to launch into + + + align:start position:0% +and and I'm hesitating to launch into +redrawing all those surfaces that I did + + align:start position:0% +redrawing all those surfaces that I did + + + align:start position:0% +redrawing all those surfaces that I did +the last time because it just if I do it + + align:start position:0% +the last time because it just if I do it + + + align:start position:0% +the last time because it just if I do it +quickly it'll be too messy to be useful + + align:start position:0% +quickly it'll be too messy to be useful + + + align:start position:0% +quickly it'll be too messy to be useful +and if I take my time I'll be repeating + + align:start position:0% +and if I take my time I'll be repeating + + + align:start position:0% +and if I take my time I'll be repeating +myself and we'll run out of time with + + align:start position:0% +myself and we'll run out of time with + + + align:start position:0% +myself and we'll run out of time with +today's lecture + + align:start position:0% +today's lecture + + + align:start position:0% +today's lecture +another way to think about it is that at + + align:start position:0% +another way to think about it is that at + + + align:start position:0% +another way to think about it is that at +any given temperature and pressure a + + align:start position:0% +any given temperature and pressure a + + + align:start position:0% +any given temperature and pressure a +fixed temperature and a fixed pressure I + + align:start position:0% +fixed temperature and a fixed pressure I + + + align:start position:0% +fixed temperature and a fixed pressure I +have these equilibrium conditions + + align:start position:0% +have these equilibrium conditions + + + align:start position:0% +have these equilibrium conditions +between the two phases + + align:start position:0% +between the two phases + + + align:start position:0% +between the two phases +and now I'm going to take a little I'm + + align:start position:0% +and now I'm going to take a little I'm + + + align:start position:0% +and now I'm going to take a little I'm +going to take a little trip + + align:start position:0% +going to take a little trip + + + align:start position:0% +going to take a little trip +I'm gonna go from one temperature and + + align:start position:0% +I'm gonna go from one temperature and + + + align:start position:0% +I'm gonna go from one temperature and +pressure to another temperature and + + align:start position:0% +pressure to another temperature and + + + align:start position:0% +pressure to another temperature and +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +and causes claparon is about making sure + + align:start position:0% +and causes claparon is about making sure + + + align:start position:0% +and causes claparon is about making sure +that I stay on that equilibrium + + align:start position:0% +that I stay on that equilibrium + + + align:start position:0% +that I stay on that equilibrium +condition + + align:start position:0% +condition + + + align:start position:0% +condition +okay I don't know if that was helpful + + align:start position:0% +okay I don't know if that was helpful + + + align:start position:0% +okay I don't know if that was helpful +um + + align:start position:0% +um + + + align:start position:0% +um +let's let's move on and then and then as + + align:start position:0% +let's let's move on and then and then as + + + align:start position:0% +let's let's move on and then and then as +time allows um come back to that + + align:start position:0% +time allows um come back to that + + + align:start position:0% +time allows um come back to that +question at the end of the lecture + + align:start position:0% + + + + align:start position:0% + +but again transformation quantities + + align:start position:0% +but again transformation quantities + + + align:start position:0% +but again transformation quantities +they're super important + + align:start position:0% +they're super important + + + align:start position:0% +they're super important +Gibbs phase rule + + align:start position:0% + + + + align:start position:0% + +we're going to go over this a little bit + + align:start position:0% +we're going to go over this a little bit + + + align:start position:0% +we're going to go over this a little bit +quickly + + align:start position:0% +quickly + + + align:start position:0% +quickly +gives phase rule is the answer to the + + align:start position:0% +gives phase rule is the answer to the + + + align:start position:0% +gives phase rule is the answer to the +following question how many phases + + align:start position:0% + + + + align:start position:0% + +can coexist + + align:start position:0% + + + + align:start position:0% + +at + + align:start position:0% +at + + + align:start position:0% +at +at equilibrium how many phases goes acid + + align:start position:0% +at equilibrium how many phases goes acid + + + align:start position:0% +at equilibrium how many phases goes acid +equilibrium so Gibbs phase rule is a + + align:start position:0% +equilibrium so Gibbs phase rule is a + + + align:start position:0% +equilibrium so Gibbs phase rule is a +linear algebra problem it's like this + + align:start position:0% +linear algebra problem it's like this + + + align:start position:0% +linear algebra problem it's like this +number of degrees of freedom + + align:start position:0% + + + + align:start position:0% + +equals number of variables + + align:start position:0% + + + + align:start position:0% + +minus number of independent + + align:start position:0% +minus number of independent + + + align:start position:0% +minus number of independent +constraints + + align:start position:0% +constraints + + + align:start position:0% +constraints +so hopefully this is um familiar from + + align:start position:0% +so hopefully this is um familiar from + + + align:start position:0% +so hopefully this is um familiar from +linear algebra so let's count variables + + align:start position:0% + + + + align:start position:0% + +I just have to go through this in order + + align:start position:0% +I just have to go through this in order + + + align:start position:0% +I just have to go through this in order +to for it to make any sense + + align:start position:0% +to for it to make any sense + + + align:start position:0% +to for it to make any sense +all right so I have + + align:start position:0% +all right so I have + + + align:start position:0% +all right so I have +let's see + + align:start position:0% +let's see + + + align:start position:0% +let's see +for phase Alpha I have a temperature and + + align:start position:0% +for phase Alpha I have a temperature and + + + align:start position:0% +for phase Alpha I have a temperature and +a pressure + + align:start position:0% +a pressure + + + align:start position:0% +a pressure +sorry bro let's say that was drawn for + + align:start position:0% +sorry bro let's say that was drawn for + + + align:start position:0% +sorry bro let's say that was drawn for +face beta I apologize for temperature + + align:start position:0% +face beta I apologize for temperature + + + align:start position:0% +face beta I apologize for temperature +temperature and pressure for Alpha + + align:start position:0% +temperature and pressure for Alpha + + + align:start position:0% +temperature and pressure for Alpha +temperature and pressure for phase gamma + + align:start position:0% +temperature and pressure for phase gamma + + + align:start position:0% +temperature and pressure for phase gamma +and so forth + + align:start position:0% + + + + align:start position:0% + +for each of pH phases + + align:start position:0% + + + + align:start position:0% + +I have + + align:start position:0% +I have + + + align:start position:0% +I have +to + + align:start position:0% +to + + + align:start position:0% +to +variables that's what I mean to set up I + + align:start position:0% +variables that's what I mean to set up I + + + align:start position:0% +variables that's what I mean to set up I +mean to suggest an array + + align:start position:0% +mean to suggest an array + + + align:start position:0% +mean to suggest an array +of phases and two variables so in this + + align:start position:0% +of phases and two variables so in this + + + align:start position:0% +of phases and two variables so in this +approach + + align:start position:0% +approach + + + align:start position:0% +approach +the number of variables + + align:start position:0% +the number of variables + + + align:start position:0% +the number of variables +in my system + + align:start position:0% +in my system + + + align:start position:0% +in my system +equals two + + align:start position:0% +equals two + + + align:start position:0% +equals two +times + + align:start position:0% +times + + + align:start position:0% +times +F and I use fa because the textbook uses + + align:start position:0% +F and I use fa because the textbook uses + + + align:start position:0% +F and I use fa because the textbook uses +p + + align:start position:0% +p + + + align:start position:0% +p +um whereas in every other page of the + + align:start position:0% +um whereas in every other page of the + + + align:start position:0% +um whereas in every other page of the +textbook p means pressure + + align:start position:0% +textbook p means pressure + + + align:start position:0% +textbook p means pressure +so I don't like what they do so I use + + align:start position:0% +so I don't like what they do so I use + + + align:start position:0% +so I don't like what they do so I use + all right so that's that's okay now + + align:start position:0% + all right so that's that's okay now + + + align:start position:0% + all right so that's that's okay now +let's do um + + align:start position:0% +let's do um + + + align:start position:0% +let's do um +let's do uh number of degrees of freedom + + align:start position:0% +let's do uh number of degrees of freedom + + + align:start position:0% +let's do uh number of degrees of freedom +the number of variables number of + + align:start position:0% +the number of variables number of + + + align:start position:0% +the number of variables number of +independent constraints + + align:start position:0% +independent constraints + + + align:start position:0% +independent constraints +number of constraints + + align:start position:0% + + + + align:start position:0% + +number of constraints I'm not going to + + align:start position:0% +number of constraints I'm not going to + + + align:start position:0% +number of constraints I'm not going to +write this out because it's very well + + align:start position:0% +write this out because it's very well + + + align:start position:0% +write this out because it's very well +presented in the text but my constraints + + align:start position:0% +presented in the text but my constraints + + + align:start position:0% +presented in the text but my constraints +are my equilibrium conditions such as + + align:start position:0% +are my equilibrium conditions such as + + + align:start position:0% +are my equilibrium conditions such as +T of alpha + + align:start position:0% +T of alpha + + + align:start position:0% +T of alpha +equals T of beta equals T of gamma + + align:start position:0% +equals T of beta equals T of gamma + + + align:start position:0% +equals T of beta equals T of gamma +equals T of all the other phases + + align:start position:0% +equals T of all the other phases + + + align:start position:0% +equals T of all the other phases +and for example P of alpha equals P of + + align:start position:0% +and for example P of alpha equals P of + + + align:start position:0% +and for example P of alpha equals P of +beta equals P of gamma equals and so + + align:start position:0% +beta equals P of gamma equals and so + + + align:start position:0% +beta equals P of gamma equals and so +forth so I have my variables and I have + + align:start position:0% +forth so I have my variables and I have + + + align:start position:0% +forth so I have my variables and I have +my constraints the variables come from + + align:start position:0% +my constraints the variables come from + + + align:start position:0% +my constraints the variables come from +counting the constraints come from the + + align:start position:0% +counting the constraints come from the + + + align:start position:0% +counting the constraints come from the +equilibrium conditions which we've + + align:start position:0% +equilibrium conditions which we've + + + align:start position:0% +equilibrium conditions which we've +already derived and let me skip straight + + align:start position:0% +already derived and let me skip straight + + + align:start position:0% +already derived and let me skip straight +to the answer + + align:start position:0% +to the answer + + + align:start position:0% +to the answer +the answer + + align:start position:0% +the answer + + + align:start position:0% +the answer +is that my number of degree of Freedom + + align:start position:0% +is that my number of degree of Freedom + + + align:start position:0% +is that my number of degree of Freedom +equals + + align:start position:0% +equals + + + align:start position:0% +equals + + align:start position:0% + + + align:start position:0% +times phases + + align:start position:0% +times phases + + + align:start position:0% +times phases +minus three + + align:start position:0% +minus three + + + align:start position:0% +minus three +times phases minus one + + align:start position:0% +times phases minus one + + + align:start position:0% +times phases minus one +equals 3 + + align:start position:0% +equals 3 + + + align:start position:0% +equals 3 +minus the number of phases this is gives + + align:start position:0% +minus the number of phases this is gives + + + align:start position:0% +minus the number of phases this is gives +phase rule + + align:start position:0% + + + + align:start position:0% + +for unitary systems + + align:start position:0% + + + + align:start position:0% + +right so this is this is um + + align:start position:0% +right so this is this is um + + + align:start position:0% +right so this is this is um +skipping straight to the answer it's + + align:start position:0% +skipping straight to the answer it's + + + align:start position:0% +skipping straight to the answer it's +more thoroughly developed than the text + + align:start position:0% +more thoroughly developed than the text + + + align:start position:0% +more thoroughly developed than the text +what does this mean that's what I want + + align:start position:0% +what does this mean that's what I want + + + align:start position:0% +what does this mean that's what I want +to get to that's why I'm rushing ahead + + align:start position:0% +to get to that's why I'm rushing ahead + + + align:start position:0% +to get to that's why I'm rushing ahead +a one phase region + + align:start position:0% + + + + align:start position:0% + +one phase + + align:start position:0% + + + + align:start position:0% + +phase equals one + + align:start position:0% +phase equals one + + + align:start position:0% +phase equals one +through gria Freedom equals two + + align:start position:0% +through gria Freedom equals two + + + align:start position:0% +through gria Freedom equals two +for example + + align:start position:0% + + + + align:start position:0% + +the TP plane + + align:start position:0% +the TP plane + + + align:start position:0% +the TP plane +right so this is getting back to what we + + align:start position:0% +right so this is getting back to what we + + + align:start position:0% +right so this is getting back to what we +know to be true which is that + + align:start position:0% + + + + align:start position:0% + +in a unary phase diagram in general I'm + + align:start position:0% +in a unary phase diagram in general I'm + + + align:start position:0% +in a unary phase diagram in general I'm +going to draw the one for water here + + align:start position:0% +going to draw the one for water here + + + align:start position:0% +going to draw the one for water here +because it's pretty familiar + + align:start position:0% +because it's pretty familiar + + + align:start position:0% +because it's pretty familiar +let's see this is temperature this is + + align:start position:0% +let's see this is temperature this is + + + align:start position:0% +let's see this is temperature this is +pressure + + align:start position:0% +pressure + + + align:start position:0% +pressure +this is liquid solid and a vapor + + align:start position:0% + + + + align:start position:0% + +in general in a urinary phase diagram + + align:start position:0% +in general in a urinary phase diagram + + + align:start position:0% +in general in a urinary phase diagram +I can stick in one phase region and I + + align:start position:0% +I can stick in one phase region and I + + + align:start position:0% +I can stick in one phase region and I +can wander around randomly in + + align:start position:0% +can wander around randomly in + + + align:start position:0% +can wander around randomly in +temperature and pressure and remain in + + align:start position:0% +temperature and pressure and remain in + + + align:start position:0% +temperature and pressure and remain in +that one phase region + + align:start position:0% +that one phase region + + + align:start position:0% +that one phase region +that's the meaning of having two degrees + + align:start position:0% +that's the meaning of having two degrees + + + align:start position:0% +that's the meaning of having two degrees +of freedom I can wander at random in + + align:start position:0% +of freedom I can wander at random in + + + align:start position:0% +of freedom I can wander at random in +temperature and pressure independently + + align:start position:0% +temperature and pressure independently + + + align:start position:0% +temperature and pressure independently +while remaining in my one phase region + + align:start position:0% +while remaining in my one phase region + + + align:start position:0% +while remaining in my one phase region +now it's considered two-phase region + + align:start position:0% + + + + align:start position:0% + +two-phase region + + align:start position:0% +two-phase region + + + align:start position:0% +two-phase region +front equals two so what's my degrees of + + align:start position:0% +front equals two so what's my degrees of + + + align:start position:0% +front equals two so what's my degrees of +freedom anybody + + align:start position:0% + + + + align:start position:0% + +one one right + + align:start position:0% +one one right + + + align:start position:0% +one one right +so what does that mean if I am + + align:start position:0% +so what does that mean if I am + + + align:start position:0% +so what does that mean if I am +in a two-phase region let's say on that + + align:start position:0% +in a two-phase region let's say on that + + + align:start position:0% +in a two-phase region let's say on that +coexistence line + + align:start position:0% +coexistence line + + + align:start position:0% +coexistence line +I can move along the line + + align:start position:0% + + + + align:start position:0% + +and maintain my two-phase coexistence + + align:start position:0% +and maintain my two-phase coexistence + + + align:start position:0% +and maintain my two-phase coexistence +condition + + align:start position:0% +condition + + + align:start position:0% +condition +that's one degree of freedom right if I + + align:start position:0% +that's one degree of freedom right if I + + + align:start position:0% +that's one degree of freedom right if I +move in temperature the move in pressure + + align:start position:0% +move in temperature the move in pressure + + + align:start position:0% +move in temperature the move in pressure +is prescribed + + align:start position:0% +is prescribed + + + align:start position:0% +is prescribed +I can't move independently in both + + align:start position:0% +I can't move independently in both + + + align:start position:0% +I can't move independently in both +pressure and temperature + + align:start position:0% +pressure and temperature + + + align:start position:0% +pressure and temperature +and it's prescribed by the cloud 6 + + align:start position:0% +and it's prescribed by the cloud 6 + + + align:start position:0% +and it's prescribed by the cloud 6 +collaboron equation we just derived that + + align:start position:0% +collaboron equation we just derived that + + + align:start position:0% +collaboron equation we just derived that +right so that's one degree of freedom + + align:start position:0% +right so that's one degree of freedom + + + align:start position:0% +right so that's one degree of freedom +is a line + + align:start position:0% +is a line + + + align:start position:0% +is a line +right this is a coexistence line + + align:start position:0% + + + + align:start position:0% + +and finally + + align:start position:0% +and finally + + + align:start position:0% +and finally +a three-phase region + + align:start position:0% + + + + align:start position:0% + +number phases equals three + + align:start position:0% +number phases equals three + + + align:start position:0% +number phases equals three +so my degrees of freedom equals zero + + align:start position:0% +so my degrees of freedom equals zero + + + align:start position:0% +so my degrees of freedom equals zero +what's a geometrical object with zero + + align:start position:0% +what's a geometrical object with zero + + + align:start position:0% +what's a geometrical object with zero +degrees of freedom + + align:start position:0% + + + + align:start position:0% + +a point what + + align:start position:0% +a point what + + + align:start position:0% +a point what +so we have in unitary phase diagrams + + align:start position:0% + + + + align:start position:0% + +so-called triple points + + align:start position:0% +so-called triple points + + + align:start position:0% +so-called triple points +these are points where + + align:start position:0% +these are points where + + + align:start position:0% +these are points where +three phases can exist at equilibrium + + align:start position:0% +three phases can exist at equilibrium + + + align:start position:0% +three phases can exist at equilibrium +can coexist at equilibrium + + align:start position:0% +can coexist at equilibrium + + + align:start position:0% +can coexist at equilibrium +however + + align:start position:0% +however + + + align:start position:0% +however +there are special points if I change + + align:start position:0% +there are special points if I change + + + align:start position:0% +there are special points if I change +temperature or pressure away from those + + align:start position:0% +temperature or pressure away from those + + + align:start position:0% +temperature or pressure away from those +points I fall out of that three-phase + + align:start position:0% +points I fall out of that three-phase + + + align:start position:0% +points I fall out of that three-phase +coexistence condition + + align:start position:0% +coexistence condition + + + align:start position:0% +coexistence condition +so for example my triple point here of + + align:start position:0% +so for example my triple point here of + + + align:start position:0% +so for example my triple point here of +water + + align:start position:0% +water + + + align:start position:0% +water +is um + + align:start position:0% +is um + + + align:start position:0% +is um +gosh what is it it's like 10 Tor and + + align:start position:0% +gosh what is it it's like 10 Tor and + + + align:start position:0% +gosh what is it it's like 10 Tor and +right around 273 see I forget exactly + + align:start position:0% +right around 273 see I forget exactly + + + align:start position:0% +right around 273 see I forget exactly +the number + + align:start position:0% +the number + + + align:start position:0% +the number +if I'm in any temperature and pressure + + align:start position:0% +if I'm in any temperature and pressure + + + align:start position:0% +if I'm in any temperature and pressure +other than that special triple point I + + align:start position:0% +other than that special triple point I + + + align:start position:0% +other than that special triple point I +cannot have all three phases coexisting + + align:start position:0% +cannot have all three phases coexisting + + + align:start position:0% +cannot have all three phases coexisting +in equilibrium + + align:start position:0% + + + + align:start position:0% + +it comes out of of this uh + + align:start position:0% +it comes out of of this uh + + + align:start position:0% +it comes out of of this uh +relatively simple linear algebra + + align:start position:0% +relatively simple linear algebra + + + align:start position:0% +relatively simple linear algebra +approach and four-phase region + + align:start position:0% + + + + align:start position:0% + +not allowed + + align:start position:0% + + + + align:start position:0% + +so from thinking about the number of + + align:start position:0% +so from thinking about the number of + + + align:start position:0% +so from thinking about the number of +independent variables in a unary system + + align:start position:0% +independent variables in a unary system + + + align:start position:0% +independent variables in a unary system +that is pressure and temperature + + align:start position:0% + + + + align:start position:0% + +and deriving the conditions for + + align:start position:0% +and deriving the conditions for + + + align:start position:0% +and deriving the conditions for +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +right which you'll recall came from + + align:start position:0% +right which you'll recall came from + + + align:start position:0% +right which you'll recall came from +entropy Max condition + + align:start position:0% +entropy Max condition + + + align:start position:0% +entropy Max condition +and thinking about those things we have + + align:start position:0% +and thinking about those things we have + + + align:start position:0% +and thinking about those things we have +arrived at + + align:start position:0% +arrived at + + + align:start position:0% +arrived at +a pretty strict set of rules + + align:start position:0% +a pretty strict set of rules + + + align:start position:0% +a pretty strict set of rules +and they're fully consistent with + + align:start position:0% +and they're fully consistent with + + + align:start position:0% +and they're fully consistent with +everything we know nature does + + align:start position:0% +everything we know nature does + + + align:start position:0% +everything we know nature does +so I think that's kind of cool + + align:start position:0% +so I think that's kind of cool + + + align:start position:0% +so I think that's kind of cool +um + + align:start position:0% +um + + + align:start position:0% +um +it's an example of the deductive power + + align:start position:0% +it's an example of the deductive power + + + align:start position:0% +it's an example of the deductive power +of thermodynamics you start with these + + align:start position:0% +of thermodynamics you start with these + + + align:start position:0% +of thermodynamics you start with these +abstract principles and some math + + align:start position:0% +abstract principles and some math + + + align:start position:0% +abstract principles and some math +and you get very practical real world + + align:start position:0% +and you get very practical real world + + + align:start position:0% +and you get very practical real world +predictions that are borne out + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% + + + + align:start position:0% + +what happens how do I get a four-phase + + align:start position:0% +what happens how do I get a four-phase + + + align:start position:0% +what happens how do I get a four-phase +region does anyone know there are four + + align:start position:0% +region does anyone know there are four + + + align:start position:0% +region does anyone know there are four +phase equilibria in nature they're + + align:start position:0% +phase equilibria in nature they're + + + align:start position:0% +phase equilibria in nature they're +allowed but they're not allowed in unary + + align:start position:0% +allowed but they're not allowed in unary + + + align:start position:0% +allowed but they're not allowed in unary +systems how do I get a four-phase + + align:start position:0% +systems how do I get a four-phase + + + align:start position:0% +systems how do I get a four-phase +coexistence + + align:start position:0% + + + + align:start position:0% + +right it happens if I somehow increase + + align:start position:0% +right it happens if I somehow increase + + + align:start position:0% +right it happens if I somehow increase +my number of variables faster than + + align:start position:0% +my number of variables faster than + + + align:start position:0% +my number of variables faster than +increase my independent constraints and + + align:start position:0% +increase my independent constraints and + + + align:start position:0% +increase my independent constraints and +that's what happens when you add + + align:start position:0% +that's what happens when you add + + + align:start position:0% +that's what happens when you add +multiple components to a system so we're + + align:start position:0% +multiple components to a system so we're + + + align:start position:0% +multiple components to a system so we're +going to revisit Gibbs phase rule when + + align:start position:0% +going to revisit Gibbs phase rule when + + + align:start position:0% +going to revisit Gibbs phase rule when +we do uh + + align:start position:0% +we do uh + + + align:start position:0% +we do uh +multi-component systems + + align:start position:0% + + + + align:start position:0% + +except + + align:start position:0% + + + + align:start position:0% + +if multi-components + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% +okay so + + + align:start position:0% +okay so +um this is the end of our treatment of + + align:start position:0% +um this is the end of our treatment of + + + align:start position:0% +um this is the end of our treatment of +urinary phase diagrams + + align:start position:0% +urinary phase diagrams + + + align:start position:0% +urinary phase diagrams +um in terms of new material on Wednesday + + align:start position:0% +um in terms of new material on Wednesday + + + align:start position:0% +um in terms of new material on Wednesday +we're going to study saturation vapor + + align:start position:0% +we're going to study saturation vapor + + + align:start position:0% +we're going to study saturation vapor +pressure in some detail + + align:start position:0% +pressure in some detail + + + align:start position:0% +pressure in some detail +uh I hope this does give you a little + + align:start position:0% +uh I hope this does give you a little + + + align:start position:0% +uh I hope this does give you a little +bit of a flavor of the pace of this + + align:start position:0% +bit of a flavor of the pace of this + + + align:start position:0% +bit of a flavor of the pace of this +class there's no way that I could cover + + align:start position:0% +class there's no way that I could cover + + + align:start position:0% +class there's no way that I could cover +all the material and work examples + + align:start position:0% +all the material and work examples + + + align:start position:0% +all the material and work examples +um in lecture and so we rely also on on + + align:start position:0% +um in lecture and so we rely also on on + + + align:start position:0% +um in lecture and so we rely also on on +the textbooks on the reading so please + + align:start position:0% +the textbooks on the reading so please + + + align:start position:0% +the textbooks on the reading so please +do keep up \ No newline at end of file diff --git a/O7AoQhYEdLA.txt b/O7AoQhYEdLA.txt new file mode 100644 index 0000000000000000000000000000000000000000..18efa83d5564ee08c22cea1d251e698567ec2be3 --- /dev/null +++ b/O7AoQhYEdLA.txt @@ -0,0 +1,603 @@ +align:start position:0% + +in this lecture would describe the + + align:start position:0% +in this lecture would describe the + + + align:start position:0% +in this lecture would describe the +Framingham Heart Study one of the most + + align:start position:0% +Framingham Heart Study one of the most + + + align:start position:0% +Framingham Heart Study one of the most +important epidemiological studies ever + + align:start position:0% +important epidemiological studies ever + + + align:start position:0% +important epidemiological studies ever +conducted and the underlying analytics + + align:start position:0% +conducted and the underlying analytics + + + align:start position:0% +conducted and the underlying analytics +that led to our current understanding of + + align:start position:0% +that led to our current understanding of + + + align:start position:0% +that led to our current understanding of +cardiovascular disease to motivate how + + align:start position:0% +cardiovascular disease to motivate how + + + align:start position:0% +cardiovascular disease to motivate how +the study affected our understanding of + + align:start position:0% +the study affected our understanding of + + + align:start position:0% +the study affected our understanding of +blood pressure today we described the + + align:start position:0% +blood pressure today we described the + + + align:start position:0% +blood pressure today we described the +case of Franklin Delano Roosevelt FDR + + align:start position:0% +case of Franklin Delano Roosevelt FDR + + + align:start position:0% +case of Franklin Delano Roosevelt FDR +for short who is the President of the + + align:start position:0% +for short who is the President of the + + + align:start position:0% +for short who is the President of the +United States from 1933 to 1945 he was + + align:start position:0% +United States from 1933 to 1945 he was + + + align:start position:0% +United States from 1933 to 1945 he was +the longest-serving president of the + + align:start position:0% +the longest-serving president of the + + + align:start position:0% +the longest-serving president of the +United States and he led the country + + align:start position:0% +United States and he led the country + + + align:start position:0% +United States and he led the country +during difficult times the Great + + align:start position:0% +during difficult times the Great + + + align:start position:0% +during difficult times the Great +Depression and World War two he died + + align:start position:0% +Depression and World War two he died + + + align:start position:0% +Depression and World War two he died +while a president on April 12 1945 + + align:start position:0% + + + + align:start position:0% + +before the president before the + + align:start position:0% +before the president before the + + + align:start position:0% +before the president before the +presidency + + align:start position:0% +presidency + + + align:start position:0% +presidency +FDR's blood pressure was 140 over 100 + + align:start position:0% + + + + align:start position:0% + +today healthy blood pressure is + + align:start position:0% +today healthy blood pressure is + + + align:start position:0% +today healthy blood pressure is +considered to be less than 120 over 80 + + align:start position:0% +considered to be less than 120 over 80 + + + align:start position:0% +considered to be less than 120 over 80 +so therefore 140 over 100 is today + + align:start position:0% +so therefore 140 over 100 is today + + + align:start position:0% +so therefore 140 over 100 is today +considered high blood pressure one year + + align:start position:0% +considered high blood pressure one year + + + align:start position:0% +considered high blood pressure one year +before his death his blood pressure was + + align:start position:0% +before his death his blood pressure was + + + align:start position:0% +before his death his blood pressure was +210 over 120 today this is called + + align:start position:0% +210 over 120 today this is called + + + align:start position:0% +210 over 120 today this is called +hypertensive crisis an emergency care is + + align:start position:0% +hypertensive crisis an emergency care is + + + align:start position:0% +hypertensive crisis an emergency care is +needed on the other hand + + align:start position:0% +needed on the other hand + + + align:start position:0% +needed on the other hand +FDR's personal physician said a moderate + + align:start position:0% +FDR's personal physician said a moderate + + + align:start position:0% +FDR's personal physician said a moderate +degree of arteriosus although no more + + align:start position:0% +degree of arteriosus although no more + + + align:start position:0% +degree of arteriosus although no more +than normal for a man of his age two + + align:start position:0% +than normal for a man of his age two + + + align:start position:0% +than normal for a man of his age two +months before his death his blood + + align:start position:0% +months before his death his blood + + + align:start position:0% +months before his death his blood +pressure was 260 over 150 and the day of + + align:start position:0% +pressure was 260 over 150 and the day of + + + align:start position:0% +pressure was 260 over 150 and the day of +his death was 300 over 190 there were + + align:start position:0% +his death was 300 over 190 there were + + + align:start position:0% +his death was 300 over 190 there were +early misconceptions in the first half + + align:start position:0% +early misconceptions in the first half + + + align:start position:0% +early misconceptions in the first half +of the 20th century about blood pressure + + align:start position:0% +of the 20th century about blood pressure + + + align:start position:0% +of the 20th century about blood pressure +high blood pressure dubbed essential + + align:start position:0% +high blood pressure dubbed essential + + + align:start position:0% +high blood pressure dubbed essential +hypertension was considered important to + + align:start position:0% +hypertension was considered important to + + + align:start position:0% +hypertension was considered important to +force blood through arteries and is + + align:start position:0% +force blood through arteries and is + + + align:start position:0% +force blood through arteries and is +considered harmful to lower blood + + align:start position:0% +considered harmful to lower blood + + + align:start position:0% +considered harmful to lower blood +pressure today of course we know better + + align:start position:0% +pressure today of course we know better + + + align:start position:0% +pressure today of course we know better +in the words of Daniel Levy the + + align:start position:0% +in the words of Daniel Levy the + + + align:start position:0% +in the words of Daniel Levy the +Framingham Heart Study director where he + + align:start position:0% +Framingham Heart Study director where he + + + align:start position:0% +Framingham Heart Study director where he +says today presidential blood + + align:start position:0% +says today presidential blood + + + align:start position:0% +says today presidential blood +numbers like FDR's would send the + + align:start position:0% +numbers like FDR's would send the + + + align:start position:0% +numbers like FDR's would send the +country's leading doctors racing down + + align:start position:0% +country's leading doctors racing down + + + align:start position:0% +country's leading doctors racing down +hallways whisking the nation's leader in + + align:start position:0% +hallways whisking the nation's leader in + + + align:start position:0% +hallways whisking the nation's leader in +to the cardia care unit of this Bethesda + + align:start position:0% +to the cardia care unit of this Bethesda + + + align:start position:0% +to the cardia care unit of this Bethesda +Naval Hospital so how do we learn in the + + align:start position:0% +Naval Hospital so how do we learn in the + + + align:start position:0% +Naval Hospital so how do we learn in the +1940s in the late 1940s the US + + align:start position:0% +1940s in the late 1940s the US + + + align:start position:0% +1940s in the late 1940s the US +government set out to better understand + + align:start position:0% +government set out to better understand + + + align:start position:0% +government set out to better understand +cardiovascular disease the plan was to + + align:start position:0% +cardiovascular disease the plan was to + + + align:start position:0% +cardiovascular disease the plan was to +track a large cohort of initially + + align:start position:0% +track a large cohort of initially + + + align:start position:0% +track a large cohort of initially +healthy patients over their lifetimes a + + align:start position:0% +healthy patients over their lifetimes a + + + align:start position:0% +healthy patients over their lifetimes a +city was chosen the city of Framingham + + align:start position:0% +city was chosen the city of Framingham + + + align:start position:0% +city was chosen the city of Framingham +Massachusetts to be the site for the + + align:start position:0% +Massachusetts to be the site for the + + + align:start position:0% +Massachusetts to be the site for the +study + + align:start position:0% +study + + + align:start position:0% +study +Framingham has an appropriate size it's + + align:start position:0% +Framingham has an appropriate size it's + + + align:start position:0% +Framingham has an appropriate size it's +not too large it's not too small it has + + align:start position:0% +not too large it's not too small it has + + + align:start position:0% +not too large it's not too small it has +a stable population that doesn't move + + align:start position:0% +a stable population that doesn't move + + + align:start position:0% +a stable population that doesn't move +too much and the doctors and residents + + align:start position:0% +too much and the doctors and residents + + + align:start position:0% +too much and the doctors and residents +were quite cooperative so in 1948 the + + align:start position:0% +were quite cooperative so in 1948 the + + + align:start position:0% +were quite cooperative so in 1948 the +Framingham starting Heart Study started + + align:start position:0% + + + + align:start position:0% + +the study included 5,000 209 patients + + align:start position:0% +the study included 5,000 209 patients + + + align:start position:0% +the study included 5,000 209 patients +aged 30 to 59 patients were given a + + align:start position:0% +aged 30 to 59 patients were given a + + + align:start position:0% +aged 30 to 59 patients were given a +questionnaire and an examination every + + align:start position:0% +questionnaire and an examination every + + + align:start position:0% +questionnaire and an examination every +two years during this examination their + + align:start position:0% +two years during this examination their + + + align:start position:0% +two years during this examination their +physical characteristics were recorded + + align:start position:0% +physical characteristics were recorded + + + align:start position:0% +physical characteristics were recorded +the behavioral characteristics as well + + align:start position:0% +the behavioral characteristics as well + + + align:start position:0% +the behavioral characteristics as well +as test results exams and questions + + align:start position:0% +as test results exams and questions + + + align:start position:0% +as test results exams and questions +expanded over time but the key in the + + align:start position:0% +expanded over time but the key in the + + + align:start position:0% +expanded over time but the key in the +study was that the trajectory of the + + align:start position:0% +study was that the trajectory of the + + + align:start position:0% +study was that the trajectory of the +health of the patients was followed + + align:start position:0% +health of the patients was followed + + + align:start position:0% +health of the patients was followed +during the entire life span in this + + align:start position:0% +during the entire life span in this + + + align:start position:0% +during the entire life span in this +class we'll be we will build models + + align:start position:0% +class we'll be we will build models + + + align:start position:0% +class we'll be we will build models +using the Framingham data to predict and + + align:start position:0% +using the Framingham data to predict and + + + align:start position:0% +using the Framingham data to predict and +prevent \ No newline at end of file diff --git a/OK7_ReXhVaQ.txt b/OK7_ReXhVaQ.txt new file mode 100644 index 0000000000000000000000000000000000000000..86073aea87de497dc5c46dfc6db65f56c369eb49 --- /dev/null +++ b/OK7_ReXhVaQ.txt @@ -0,0 +1,357 @@ +PROFESSOR ROBERT DORKIN:Hi, and +welcome to a help session + +on recombinant DNA. + +Today we will be talking about +the polymerase chain reaction + +as well as DNA sequencing. + +The polymerase chain reaction, +also known as + +PCR, has many uses. + +One of the most common +uses is to amplify a + +desired section of DNA. + +What you need for the reaction +is your DNA sequence of + +interest, DNA polymerase, DNA +primers, and then four + +different nucleotides. + +You combine all these together, +and the first thing + +that you do is you heat +the reaction up. + +What this does is that by adding +heat to the system, you + +break the hydrogen bonds +between the two + +different DNA strands. + +This results in two separate +DNA sequences. + +Now what happens is that you +allow the system to cool. + +As it cools, the DNA primers are +able to hybridize to this + +separate strands. + +Now as you remember from +lecture, when you're + +synthesizing DNA, you synthesize +from the five prime + +to three prime direction. + +This means that the primers you +design have to match the + +three prime end of your +sequences of interest. + +So for example, if we were +designing primers for these + +two sequences, one of them would +be GGTA and the other + +one would be AGCT. + +Now, I've written four here. + +In actuality, these primers are +generally longer, around + +16 or so, 16 to 27. + +However, they can be a whole +different variety of lengths + +dependent on numerous +different factors. + +The next thing that happens is +that the DNA polymerase is + +going to bind to the DNA +sequence with the primer. + +Once the DNA polymerase is +bound, it's going to take some + +of the free nucleotides in the +surrounding area and slowly + +add them to finish +up the strand. + +And so on and so forth. + +Once it's completed, we are +going to have now doubled our + +original DNA sequence. + +We're going to have two strands +that are identical to + +the first one. + +As you can see, by repeating +the steps, heating it, + +allowing it to cool, allowing +more primers to bond, and then + +allowing the DNA polymerase to +elongate, we can double the + +number of sequences +every round. + +And you can rapidly +get a large amount + +of the desired sequence. + +PCR has other uses though +besides simply increasing the + +total amount of DNA +that you have. + +One of the uses of PCR +is to sequence DNA. + +Now, if we look over here, +normally DNA is form of + +deoxyribonucleic acids. + +You have the phosphate group +on the five prime end. + +You have a hydroxyl group +on the three prime end. + +This hydroxyl group +is very important. + +That's because when a new +nucleotide is added, this + +hydroxyl group undergoes a +covalent bond with the + +phosphate on the new nucleotide +and then adds a new + +nucleotide that way. + +So you can see you're adding +the five prime + +the three prime direction. + +However, it is possible +to create a + +dideoxyribonucleic acid. + +The dideoxyribonucleic acid, +instead of having a three + +prime hydroxyl group, has +a three prime hydrogen. + +This three prime hydrogen is no +longer capable of forming a + +covalent bond with +a phosphate. + +That means as soon as the +dideoxyribonucleic acid is + +added to DNA, no further +nucleotides can be added in + +the series. + +Let's go back to our example +with the primers. + +What does that mean for here? + +Well, let's say you have a +normal PCR reaction, but in + +addition to the four +deoxyribonucleic acids you + +have, you also take a little +bit of dideoxyribonucleic + +acids of one of the types. + +So let's say we add +in some ddTTP. + +Now what happens is that your +DNA polymerase will go along + +adding nucleotides as normal, +but if it ever adds a + +dideoxyribonucleic acid, the +polymerase will stop. + +So if it adds, say +a normal T here-- + +continues down, continues +down. + +If it adds a dideoxyribonucleic +acid here, + +it's going to stop, +and we're going to + +get a truncated sequence. + +And so you can see that at any +position that we have an A, + +it's going to be possible to +have a truncated sequence of + +that length. + +What this means that we're now +going to, once the PCR is + +complete, have different DNA +sequences of numerous + +different lengths. + +But the one thing they're all +going to have in common is + +that they're all going to end +with a T. So you can imagine + +doing this now for each of the +four different letters. + +Then we can take them and +run them out of a gel. + +Let's go look at such +a gel over here. + +Here we have a gel. + +Each of these letters +represents which + +dideoxyribonucleic acid was +used for that experiment. + +And then the PCR was +run out on the gel. + +As you remember, the strands +close to the bottom are the + +shorter strands, and the strands +close to the top are + +the longer strands. + +So if we look at this gel, we +know that the shortest strand + +ends with a G. The next shortest +strand ends in a T. + +Oh, sorry, ends in +an A, excuse me. + +Then the next short strand ends +in a T, then two A's, + +then a G, then a C, then a T. So +as you can see, this is one + +way to determine the +sequence of DNA. + +Another way has been devised, +which is even faster. + +Instead of running the sequences +all out in different + +polymerase chain reactions, what +they do is they have some + +of each of the +dideoxynucleotides together. + +But now, they fluorescently +label them, such that you have + +a different fluorescent +label on each + +dideoxyribonucleic acid. + +Now what happens is that +you can run it + +out all on one column. + +And then by just looking at the +colors, you can determine + +what the sequence is. + +So once again, the sequence +would be GATAAGCT. + +And so this way, you can more +efficiently, more rapidly, + +determine what the +DNA sequence is. + +This has been two examples of +polymerase chain reactions and + +their uses. + +This has been another help +session on recombinant DNA. + +We hope you join us +again next time. + +Thank you. \ No newline at end of file diff --git a/OznepAivkkg.txt b/OznepAivkkg.txt new file mode 100644 index 0000000000000000000000000000000000000000..b211be1ef23aa78b2bf149d27cde56ebdedb577c --- /dev/null +++ b/OznepAivkkg.txt @@ -0,0 +1,2222 @@ +PROFESSOR: All right. + +Lecture 17 was about folding +polygons into polyhedra, + +and today we will do it +with real pieces of paper. + +But before we get +there, I want to talk + +about some things we could make. + +In lecture, I demonstrated +this perimeter having technique + +where you take +any convex polygon + +and you pick any point +on the perimeter. + +Then you measure out the +perimeter halfway on each side. + +You get the antipodal point, y. + +And then just +glue-- locally, you + +glue everything +around x and around y. + +So I mean, you just start. + +We call this zipping where you +don't glue any extra material + +in here, you just start +zipping these guys together. + +I guess these circles or when +you happen to hit this vertex, + +well, then you just keep +going-- zip, zip, zip, zip, zip. + +So that's one thing we could +make with convex polygons. + +Slightly more general +is called a pita form. + +This is defined in the textbook. + +And the idea is instead +of a convex polygon, + +you could take any convex body. + +It could have some corners +or it could be smooth. + +So this is what +we call a convex, + +or what I'm going to call +today a convex 2D body, meaning + +it can be smooth in +addition to polygonal. + +And then you pick any +point on the boundary + +and you measure out the +perimeter halfway, x and y, + +and you glue in +exactly the same way. + +Now, it does not follow +from Alexandrov's theorem + +that this will make +a convex thing, + +but it follows from a +slightly more general form + +of Alexandrov's theorem called +Alexandrov-Pogorelov theorem. + +So Pogorelov was a +student of Alexandrov + +and he edited some things +that Alexandrov wrote, + +but then also Pogorelov +wrote his own papers + +and proved some +stronger versions + +of Alexandrov's theorem that +hold for smooth bodies, not + +just polygonal folding. + +So Alexandrov's +theorem, you recall, + +if you have a convex +polyhedral metric homeomorphic + +to a sphere, then it's realized +by a unique convex polyhedron. + +So the Pogorelov's extension +is that if you have everything + +except the polyhedral +part-- so if you + +have a convex metric +homeomorphic to a sphere-- so + +topologically it's a sphere, +but we omit the polyhedral part. + +So polyhedral was that you +have finitely many vertices. + +In some sense, I have +infinitely many vertices, + +infinitesimal curvature +at every point here. + +Then it's realized by a +unique convex 3D body. + +So same concept of +a convex object. + +Well, I should say this +is really the surface of. + +So a convex body, I should +probably define that. + +Convex body is one where +you take any two points + +and you draw a +straight line and you + +stay within the body for +the entire straight line. + +So that's convex. + +You take any two points, +like this one and this one, + +draw a line between them, +and you stay inside. + +The body is the piece of +paper we're gluing up. + +Here we have a 3D +body, but then we + +just look at the surface +of it, the boundary. + +And that's going to be +the surface we make. + +Technically, that +surface is not convex. + +It's the interior that's convex +because you can draw lines + +through it and you stay inside. + +This is exactly the same thing, +but instead of polyhedron here, + +we have body because we didn't +have finitely many vertices. + +And I'm not going to +prove this theorem. + +But existence is +basically the same proof. + +You just take a limit. + +So you can polygonalize +with lots of little edges + +here, add little points, +and take the limit + +as that approximation gets very, +very close to the actual curve. + +At all times you +have a polyhedron, + +it's easy to show you will +converge to a convex body. + +The uniqueness is the +harder part, I believe. + +I haven't read the proof, +but it was more challenging. + +I think that took 20 years +or so to settle uniqueness. + +Alexandrov's like 1950. + +This theorem I think is +1973 the final version. + +But the version without unique +was proved back in 1950. + +So that's something +else we can do. + +Instead of cutting +out a polygon, + +we can cut out a nice smooth +thing or you can add some kinks + +and be smooth elsewhere. + +As long as it's +convex, then you're + +guaranteed that-- we're +only gluing together + +two convex points. + +It could be flat or it +could be strictly convex, + +which means we'll have at most +360 degrees of material at any + +point because it's always +doing two at most 180's. + +And so we will have +a convex metric, + +meaning always at most 360 +of material everywhere. + +So then this theorem applies +so we'll get a unique thing. + +Another thing we could +make is called a D-form. + +And I have some examples +of D-forms here. + +So the idea with the D-form is +you take two convex 2D bodies-- + +so here they have some +straight parts and some curve + +parts-- of the same perimeter. + +I pick one point from one +body and I pick another point + +from the other body. + +I attach them there. + +And then I zip. + +So it would be zip, +zip, zip, zip, zip. + +Wherever my fingers +were at the same time, + +those are points that +get glued together. + +And this is with the +convex body you get. + +Again, Alexandrov-Pogorelov +applies because we're still + +only gluing two convex +points together at any point. + +As long as these guys +have matching perimeter, + +we'll be OK. + +And so we will get a +unique convex 3D body. + +In this case, we get +this fun kind of shape. + +So this is what I +suggest you make. + +D-forms tend to look a +little bit cooler somehow + +because they have two polygons. + +And the one that's +particularly easy to build + +is two copies of the +same shape, but then you + +don't want to glue +corresponding points. + +Like if I glued this +point to that point, + +I would just get a flat, +doubly covered thing + +and that's boring. + +But you just pick +some other point + +and glue it to +non-matching points, + +then it acts like you have +two very different convex + +bodies which is kind of cool. + +I have some images +of D-forms here. + +There's actually a whole book +on D-forms by John Sharp. + +They're invented by this guy +Tony Wills who's an artist. + +At the top, the +quote is, "there is + +no such thing as +an ugly D-form." + +So we are guaranteed +success here. + +And also it says, "they +surprise, confuse, + +can be addictive. + +They're an intellectual virus. + +Beware." + +So you've been warned. + +This is Tony Wills, +the inventor. + +Now, from the +artistic perspective, + +you don't have to start +from convex polygons. + +We're going to start +from convex bodies + +because they're +guaranteed to work. + +If you're careful to satisfy +Alexandrov-Pogorelov, + +you can have a convex +metric even though you + +start from nonconvex bodies, +although in this case, + +he's actually getting +nonconvex shapes as well. + +More typical D-form is +something like this. + +This is made from two ellipses +and he builds them out + +of metal. + +This is a simulation by +this guy Kenneth Brakke + +who has this software +called Surface Evolver. + +And it's usually used for +computing minimal services, + +soap bundles and +things like that. + +But here it's computing +what D-forms look like, + +approximately. + +And so this is an example +of taking two ellipses + +and instead of-- if you +glue at matching points, + +they would be flat-- but +then you change the rotation. + +So here, they're rotated by 22.5 +degrees, rotated by 45 degrees, + +rotated by 90 degrees, so +you get this nice continuum + +of different things that +you could zip together. + +So I propose we make some. + +And so you have your +scissors and tape. + +If you don't have two sheets of +paper, get some from the front. + +And so everyone have +scissors, tape, everything? + +We're going to have +to share a bit. + +So what we want to do is make +two identical convex shapes. + +So you have some here. + +Two rectangles are +valid convex shapes. + +You could cut not all. + +Everyone should do +something different. + +I'm just going to make sure +they're nicely aligned. + +Hold on tight because you +don't want them to let go, + +and then just cut. + +Always turn left +with your cutting. + +You can be smooth. + +You can have some corners, +what you want to do. + +Just always turn left. + +And once you have your two +shapes, you pull them apart. + +Make sure you do not glue +corresponding points. + +Pick some other points and +attach them together with tape. + +Here's where it gets a +little bit challenging. + +With smooth curves, it's little +harder to tape them together, + +so you're probably going to +have to use a bunch of points + +of tape, so to speak, +not literal points. + +And I just tape, tape, tape. + +Before you get all +the way, you want + +to make sure you can still +pop it up and be convex. + +I think we'll be able to +do that by [INAUDIBLE] + +inside the limit. + +Give me some scissors. + +All right. + +There's my D-form. + +Mostly convex, kind of fun. + +So a funny thing you'll +notice about D-forms, + +if you made yours +smooth-- so if you don't + +have any kinks on the +outer boundary-- then + +the surface looks smooth, +which is kind of nice. + +The other thing is there's +this noticeable seam where + +you taped things. + +There, you're not +smooth, obviously. + +You've got a crease +along the seam. + +But also it looks like all +that the surface is doing + +is kind of taking +the convex hull, + +the envelope of that seam. + +So there's two +properties we observe. + +One is that it looks +smooth, except at the seam. + +And the other is +that the hull surface + +is the convex hull +of the 3D seam. + +And I want to prove +both of those things. + +Those are both true facts. + +But first I need to +define some things. + +So we're going to +prove that D-forms + +are smooth and +other good things. + +This is a paper +that was originally + +a class project in this +class, I think in 2007. + +Sounds about right. + +Submitted during class, it looks +like, or just after semester + +with Greg Price. + +D-form have no spurious creases. + +So what's a D-form? + +You take two, for +us, it's going to be + +two convex shapes +of equal perimeter. + +You glue two points, two +corresponding points P and Q + +together, and then +you zip from there. + +We can actually talk about +something even more general + +which we'll call a seam form. + +A seam form, you can have +multiple convex shapes. + +It's a little harder +to imagine, but you + +can join multiple +points together. + +Maybe you join all three +of those corners together. + +As long as you have at most +360 of material everywhere, + +it'll be fine. + +Maybe do some zipping. + +I'm not going to try to figure +out exactly how this gluing + +pattern works, but you +find a gluing pattern + +where you don't +violate anything. + +So it looks like +if I do this one, + +I better have these +guys also a little bit + +sharp so that they don't add +up to too much angle there. + +So these three points +would also join together. + +This would be like three +petals in like a seed pod + +or something, like those leaves +that wrap around little fruits + +or something. + +I won't try to draw it but-- +I guess I will try to draw it. + +Something like this. + +So that's a thing. + +This could even fold +not exactly a sphere, + +but something like a sphere. + +So seam forms, you could have +any number of convex shapes + +and glue them together +however you want, + +provided at all points you +satisfy Alexandrov-Pogorelov, + +so you only have at most +360 degrees of material + +and you are +topologically a sphere. + +Then you have a seam form. + +So most of the theorems I'm +going to talk about apply + +to general seam forms, but we're +interested in D-forms and pita + +forms in particular. + +So let me tell you some +theorems about seam forms. + +Theorem 1 is that +a seam form equals + +convex hull of its seams. + +So the seams in +general are these parts + +where you did gluing, +wherever you taped stuff. + +The boundaries of the convex +polygons, those are the seams. + +They map to some curves in 3D. + +If you take the +convex hull, the claim + +is you get the entire seam form. + +That's actually +pretty easy to prove. + +Then the second +claim is there aren't + +many creases other than +the seams of course. + +The seams are usually +going to be creased. + +And these creases are +going to be line segments. + +And not just any line +segments, but their endpoints + +are pretty special. + +So the claim is that +the creases have + +to be line segments basically +connecting strict vertices. + +What do I mean by strict vertex? + +Something like these three +points which come together, + +provided the total angle here +is strictly less than 360. + +I call that a strict vertex. + +Whereas these points +connecting from here to here, + +those don't count +as strict vertices. + +They do have curvature, but +only infinitesimal curvature. + +Because this is essentially +180 degrees of material, + +just slightly less +because it's curved. + +So only where I have +kinks can I potentially + +have strictly less than 180. + +And if I join them together +to be strictly less than 360, + +that's a strict vertex. + +So potentially, I have a +seam coming from here, also + +at the other endpoint. + +So in this picture, I might +have a crease like this, + +I might have a +crease like this, I + +might have a crease +like this, potentially. + +But in something like a D-form, +there are no strict vertices. + +If these are smooth-- so I'll +assume here these are smooth. + +We could call it a smooth +D-form if you like. + +Then there's no vertices, +no strict vertices, + +only these sort of +barely vertices. + +So there could be no creases. + +There's one other +situation which + +is creases could be +tangent to seams. + +This should seem +impossible because the way + +I've defined things +it is impossible. + +You're tangent to a seam, that +would be you're like this. + +How am I supposed to have +a crease inside that's + +tangent to the seam? + +The answer is you can't. + +If these regions are +convex, you can't have them. + +This statement is actually +about a more general form + +of seam forms where you +can have a nonconvex piece. + +So in general seam form, you +have a bunch of flat pieces + +and you somehow search +for them together so + +that you satisfy +Alexandrov-Pogorelov. + +And now you could +have a tangent. + +I could, for example, have a +crease that emanates from there + +or have a crease that +emanates from there. + +But right now, it +has nowhere to stop. + +The only way for these +creases to actually exist + +is if there's a +kink here, then this + +could go from there to there. + +So this is starting at a +vertex and ending tangent. + +You could, of course, also +start tangent and end tangent + +if there's another bend. + +But the claim is, +all crease look + +like that, which +means if you carefully + +designed your thing +or vaguely carefully + +such as a smooth +D-form, then you're + +guaranteed there are no creases +which is what we observe. + +So this is justifying our +intuition from these examples. + +One other case is the pita form. + +So pita form does +actually make vertices. + +This point x is going to be +a strict vertex because it + +has less than 180 of +material, so definitely + +strictly less than 360. + +Same with y. + +So pita form is +potentially going + +to have a seam from x +to y, but that's it. + +Sorry, a crease from x to y. + +It has at most one crease. + +I think most examples +we've made do + +have such a crease from x to y. + +Let's prove these theorems, +or at least sketch the proofs. + +Don't want to get +too technical here. + +So to prove the first +part that the seam form is + +convex hull of its seams, it's +helpful to have a tool here + +which is a theorem by Minkowski. + +We'll call it +Minkowski's theorem, + +although he has a bunch. + +Hermann Minkowski. + +It relates convex +things to convex hulls. + +It says, any convex +body is the convex hull + +of its extreme points. + +What are extreme points? + +Extreme points are points +on the surface where + +you can touch just that +point with a tangent plane. + +So if you think of +polyhedra, these + +are vertices of the polyhedra. + +But I want to handle +things that are smooth, + +so they may might not +really have any vertices. + +In general, I have +some convex body. + +If I can draw-- imagine +this is in two dimensions-- + +if I can draw a +tangent plane that just + +touches at a single point, +then I call that point extreme. + +Let's look at an example here. + +Here I believe +every seam point is + +going to be an extreme +point because I + +can put a tangent plane. + +It just touches at that point. + +What am I distinguishing from? + +Well, for example, this point, +this surface is developable. + +We know it's ruled. + +So there's a straight line here. + +You can see it in the +shadow, in the silhouette. + +If I said, is this +point extreme? + +I try to put a tangent +plane on, the only way + +to get a tangent plane is +to include this entire line. + +So it's impossible to +just hit this point + +or any point along that line. + +In fact, every interior +point, I claim, + +you cannot just hit that point. + +You've got to hit +an entire line. + +Whereas at the +seam, I can do it. + +I can angle between +this and this. + +There's a tangent +plane, because this + +is curving, that only +hits at one point. + +If I had a straight +segment, then + +the endpoints of the +straight segment of the seam + +would be extreme, but the points +in the middle of the segment + +would not be extreme. + +So that's the +meaning of extreme. + +And we're going to +use this because I + +claim that these interior +points can never be extreme. + +It can only be the seam +points that are extreme. + +And therefore, we are the +convex hull of the seam points + +because we are the convex +hull of the extreme points. + +How do we argue that? + +So I claim an extreme +point can't be locally flat + +and at the same time be convex, +because convex in 3D, that's + +what we need. + +If you had a point and it +just meets a tangent plane + +at that single point, +that means locally + +you're kind of going +down from that plane, + +if you think of that +plane as vertical. + +So this is a situation. + +I want to prove this. + +To prove it, I need to +introduce another tool which + +is a generally good +thing for you guys + +to know about, so +kind of an excuse + +to tell you about the Gauss +sphere, which I don't think we + +actually cover in lectures, +but might come up again. + +Gauss sphere is a simple idea. + +For every tangent +plane-- let's just think + +of this single point. + +I want to look at the-- it's +called the tangent space. + +Look at all the tangent +planes that touch this point. + +Because this +particular tangent plan + +I drew only touches that one +point, it has some wiggle room. + +I can pick any direction +and just wiggle + +and rotate the plane +around this point + +and it won't immediately +hit the surface. + +I've got a little bit of time +before it hits the surface. + +So there's a two-dimensional +space of tangent planes + +that touch just this point. + +Because there's +at least one, I've + +got to have some wiggle room. + +So I want to draw that space. + +And a clean way to draw the +space is for every such plane + +to draw a normal vector +perpendicular to the plane, + +take the direction of +that normal vector, + +and draw it on a sphere. + +It's a unit sphere. + +So this is a sphere. + +This one looks pretty vertical +so that would correspond + +to the north pole of the sphere. + +So that direction becomes +a point on the sphere. + +Think of it as this vector +from the center of the sphere + +to the north pole. + +But we'll just +draw it as a point. + +And because I've got a +two-dimensional space + +of maneuverability or +rotatability of this plane, + +I'm going to get some +region-- which maybe I + +should draw like +this-- of the sphere. + +Those are all the +possible normal vectors + +of tangent planes at that point. + +So this is called the Gauss map +where you map all these normals + +to the Gauss sphere, which Gauss +sphere is just a unit sphere. + +Fun fact. + +The area of that thing, +which is the map of all + +the tangent normal directions, +equals the curvature + +at that point. + +You may recall at +some point curvature + +is actually Gaussian +curvature, so that's + +why Gauss is all +over the place here. + +Now because I claim this +is a two-dimensional space, + +this thing will +have positive area. + +Therefore, at this +point, that vertex + +has positive curvature +on the surface. + +And yet, it was supposed +to be in the middle of one + +of these flat shapes. + +That's supposed to +have zero curvature. + +Contradiction. + +Or stated more +positively, if I have + +a point that is +an extreme point, + +it's only touched by +one of these planes, + +I have this flexibility. + +Therefore, I get area. + +Therefore, it is +not locally flat, + +so it must be a seam point. + +It could be one like this +where I'm barely non-flat, + +but I am non-flat. + +There's kind of +infinitesimal curvature here. + +Or it could be one of these +points where I'm very non-flat, + +or I guess X and Y here +are other examples of here + +I'm very not flat. + +I've only got 180 degrees +of curvature roughly. + +So it's got to be one +of those if you're + +going to be an extreme point. + +Therefore, all the extreme +points are seam points. + +Therefore, convex hull +of the extreme points + +is the convex hull of the seams, +and that is your seam form. + +So that's part one. + +It's pretty easy. + +Let me tell you about part two. + +Part two builds on part one. + +It's one reason +why we care about. + +So part two is that there +are no spurious creases. + +Unless you have strict +vertices, then you + +could connect those up. + +So let's look at a +locally flat crease point. + +Actually, at this point, +I should probably mention. + +This paper, I think of as a +forerunner to the "How Paper + +Folds Between +Creases" paper which + +is that hyperbolic +parabolas don't exist. + +You may recall there were +theorems about what creases + +look like, what ruled +surfaces look like, + +and so on between creases. + +In that setting, we've proved +things like straight creases + +stay straight and all +these good things. + +Here, it's a little +bit different + +because we have kind of +two levels of creases. + +There's the seam +which is special. + +And then we're imagining +hypothetical creases + +between the seam. + +And could you have +a curved crease? + +Claim is no. + +Claim is all the creases +in between the seams + +have to be straight. + +And in fact, they +can't look like this. + +They have to be at +corners somehow. + +So that's what we're +going to prove. + +But a lot of the +same techniques, + +most of the same definitions. + +This paper was +kind of a warm up, + +I feel like, for +the nonexistence + +of hyperbolic parabolas. + +Although they use a +lot of the same tools. + +They have two of +the same authors, + +but there's no +theorem that really + +is shared between the two. + +They're not identical. + +So we're looking +inside a flat region. + +We're imagining, let's +look at a crease point. + +It lies on some crease locally. + +And it's a fold crease. + +So I'm going to wave +my hands a little bit. + +But imagine a folded crease. + +Maybe it's a curve. + +We don't know. + +It's folded by some +angle, some nonzero angle. + +Otherwise, it's not a crease. + +So locally, it looks like +two kind of planes, at least + +to the first order they're +going to be planes. + +Maybe something like this. + +I'm going to draw +the creases straight + +because to the first +order, it is straight. + +But it might be slightly curved. + +So we're looking +at a point here. + +And my point is, it's +bent by some angle. + +So I'm going to draw +the two tangent planes. + +There's a tangent +plane on the right. + +Whatever the surface +is doing on the right, + +there's a tangent +plane over there. + +Whatever the surface is doing +on the left of the crease, + +there's a tangent plane there. + +They're not the same plane +because we are creased. + +Whatever the crease +angle is, that's + +the angle between +these two planes. + +I want to look at this tangent +space again a little bit. + +You can think of it, +the tangent space + +at the least it has +this tangent plane. + +For this point, you have +at least this tangent plane + +and at least this +other tangent plane. + +And so in particular, you have +to have the sweep between them. + +So you get at least a +one-dimensional set there. + +Now, this can happen. + +So we're not going to +get a contradiction. + +We're not going to +suddenly discover + +there's a two-dimensional area +and get that it wasn't flat. + +But at least we've got +a one-dimensional arc. + +On the Gaussian sphere here, +we've got something like this + +so far. + +This is one extreme +tangent plane on the left. + +This is extreme tangent +plane on the right. + +These two points +correspond to those two. + +And then we've got +the arc of-- you + +can sweep the tangent +plane around and still + +stay outside the surface, + +Well, that's interesting. + +It's interesting because +all of those tangent planes + +share a line, which is going to +be this line that I drew here. + +I mean, you look at +these two planes, + +there's a line that they share. + +And if you rotate the +plane through that line, + +you'll still pass +through this point + +and you won't hit the surface. + +So in fact, all those tangent +planes share this line. + +I think we actually +just need these two. + +So if you don't see +that, don't worry. + +There are these two planes. + +There's a line there. + +They're tangent, +which means that line + +is on or outside the surface +because tangent planes don't + +hit the surface. + +I mean, they touch +the surface barely, + +but they don't go interior. + +Well, I claim that in fact the +surface must touch this line. + +I claim the surface, +at least locally, + +has got to follow +along that intersection + +line of the left and +right tangent planes. + +Why? + +It comes down to this +Gaussian sphere thing. + +We know that the surface +lies inside these two planes. + +There's this wedge here. + +The surface must be below. + +We also know the surface comes +and touches it at this point. + +Could it, from here, kind of +dip down away from this line? + +I claim no. + +If it dipped down, then there'd +be a third tangent plane. + +The tangent plane could +follow and dip down as well. + +And then we've got not +just a one-dimensional arc, + +but we're actually going to get +a whole triangle in the Gauss + +sphere. + +Once you have a whole triangle, +that means you weren't flat. + +You have positive curvature. + +So we're looking at a +locally flat crease point + +somewhere in the middle +of one of these polygons. + +So in fact, you can't afford +to dip down because then you'd + +have at least a little +bit of curvature there. + +Because you have zero curvature, +you've got to stay straight. + +So that means that +the surface locally + +has to exist along the +segment in both directions + +until something happens. + +Now, we assumed +that our point was + +locally flat and a crease point. + +So the surface must +continue in this direction + +until we reach a point that +is either not locally flat + +or not a crease point. + +I claim it's got to +remain a crease point. + +Because look, you're following +along this intersection + +line of these two +tangent planes. + +These remain tangent planes. + +These are not only tangent +planes at this point. + +They're also tangent +planes at this point + +and potentially any +point along this segment. + +As long as the surface is +here, they are tangent planes. + +Therefore, you are creased here. + +I mean, you can't be +smooth if you're butting up + +against these two +tangent planes. + +So crease must be preserved, so +the only issue is locally flat. + +It could be at some point +you become not locally flat. + +And that indeed happens. + +That's when you hit the seam. + +When you hit the seam, then +you're no longer locally flat. + +So this proves the +creases must be + +line segments between +two points on the seam. + +There's a little bit more to +prove which is it either hits + +a strict vertex or +it's tangent to seams. + +And this basically +follows the same argument + +that if you hit something other +than a strict vertex or a seam, + +you would have positive +curvature where + +you shouldn't, basically. + +So I'll just leave it at that. + +I think that's +enough for the proof. + +You get the idea why +creases can't exist. + +Any questions about that? + +I have few more questions. + +One question is, can we see +more examples of rolling belts? + +And in some sense, +this example is + +an example of a rolling belt. + +So D-forms, you take +two, say, ellipses. + +And the seam that connects +them is a rolling belt. + +And this is an illustration +of the rolling action. + +As you change, which point +glues to which point? + +Let's say I fix this point. + +I can glue to this one or +to this one or to this one + +or to this one. + +And then I zip around. + +That's the rolling of the belt. + +More generally, +I'll draw a picture. + +More generally, a rolling +belt from the viewpoint + +of a gluing tree is that +you have basically it's + +like a conveyor belt +like at the airport + +or on a tank or something. + +You've got treads here +and it's going to roll. + +So if I mark a point, let's +say I mark this point. + +And I roll it around +this way a little bit, + +this point maybe +stays stationary + +and I end up with +something like this. + +And what that means is whatever +this guy glued to over here + +is now over here. + +So we're changing the gluing. + +This guy's now getting glued +to some point like this + +because it kind of rolls around. + +So in general, +you're rolling this, + +but then you're always just +gluing across this path. + +For this to work, every angle +out here must be less than + +or equal to 180, +like the material + +that's out on the outside. + +Remember, the gluing +tree has the outside + +of the polygon in here. + +The inside of +polygon's out here. + +So all the material's +on the outside here. + +All of these things must be +less than or equal to 180. + +If you can find a path +in your gluing tree + +where you've got less than +180 material all around you, + +then you can do this rolling. + +And no matter how you roll, +and then just glue across, + +you will still have a valid +gluing, a valid Alexandrov + +gluing. + +So that's what rolling +belts look like in general. + +We see them all over the +place with these D-forms. + +The simple example +I showed in class + +was when you take a rectangle, +you glue into a cylinder. + +And now up here, I've +got a rolling belt. + +Because if you look +at the sides here, + +I've got actually exactly +180 degrees of material + +all around the belt. + +And so I could +collapse it like this + +or I could collapse +it-- let me tape it. + +A little hard to +hold everything. + +If you look at this belt, I +could collapse it like this. + +Or I could roll it a little +bit and classify like that. + +Or I could roll it a little +bit, collapse it like that. + +Roll it a little more. + +Collapse it like that. + +All of these are valid +gluing because they're always + +gluing 180 to 180. + +And that's what +rolling belts are. + +Does the broken applet work now? + +I don't know why +it wasn't working. + +Probably some conflict +with suspension + +or just the Java +installation was bad. + +But here it is. + +It's freely available online. + +You draw your graph. + +It's a little hard to just use. + +It's hard to draw +an exciting example. + +Here I'll a draw a tetrahedron +because that's simple. + +In this case, it's abstract, +so all of these edges + +are unit lengths. + +It's kind of like TreeMaker. + +You separately +specify the lengths. + +Then you say Compute. + +And it will find, in this +case, it's a tetrahedron, + +an equilateral. + +A regular tetrahedron +is a little hard + +to see because we've got +either a weird field of view + +or a lot of perspective here. + +But this is a +regular tetrahedron. + +You can verify that by say +making some of these lengths + +longer. + +I'll make three of them five. + +So then this is like a pyramid. + +Of course, we're just +essentially applying + +Cauchy's rigidity theorem here +and say, oh, this uniquely + +assembles into this +spiky tetrahedron. + +You could, in principle, +drawn an across here + +with the appropriate gluing. + +It's a little tricky +to draw in because you + +have to also triangulate. + +It'd be hard to do from +scratch to compute gluings. + +But in theory, especially +if you use software + +to compute the gluings +and compute shortest + +path in a glued +polygon-- which we'll + +be getting more to next class. + +Next lecture is about +algorithms for finding gluings. + +Then computing shortest paths. + +Then you could use that as +input to this software which + +will then compute what +the 3D polyhedron is. + +So that's the Alexandrov +implementation. + +This is by, I think, a student +of Bobenko and Izmestiev. + +One quick question +about-- running out + +of time-- about +the nonconvex case. + +So we're doing all this work +about making convex surfaces. + +I said nonconvex +case is trivial. + +In a sense, the decision +problem is trivial. + +It's not an easy +theorem to prove. + +And aha, taped it up. + +It follows from what's called +the Burago-Zalgaller theorem. + +And it says that if you tap +any polyhedral metric-- so that + +means you take a polygon, +you glue it however you want. + +You could even add boundary. + +Pick any polyhedron metrics, so +you take any polygon and glue + +it however you want. + +It could have handles. + +It could be a doughnut. + +It could be whatever. + +Then it has an isometric +polyhedral realization in 3D. + +So there is a way-- so +we're doing it abstractly. + +We're gluing stuff together. + +It's kind of topologically. + +We don't know what we're doing. + +But then there is a way +to actually embed it + +as a polyhedral surface +in 3D without stretching + +any of the lengths. + +So it's a folding of +the piece of paper. + +It could have creases in +it, will have actually + +tons of creases in it. + +And it has exactly the +right-- it connects + +all the things you want +it to connect together. + +It's kind of crazy. + +Furthermore, it could +be self-crossing. + +But if your surface +is either orientable-- + +so it doesn't have any cross +caps or Mobius strips in it-- + +or it has boundary, +then there's even + +a way to do without crossings. + +So that's basically all +the cases we care about. + +You could glue this together +into a sphere or into a disk + +or into a torus or +two-handled torus or whatever. + +No matter what you +do, there is a way + +to embed it in 3D as a +presumably nonconvex very + +creased surface. + +This is a hard to prove. + +If you're familiar +with Nash's embedding + +theorem about embedding +Riemannian surfaces, + +it uses a bunch of techniques +from there called spiraling + +perturbations, +which I don't know. + +And one description I read +calls the resulting surfaces + +"strongly corrugated," which +I think means tons of creases. + +It is finitely many creases. + +That's the theorem. + +There's no bound on them. + +As far as I know, +there's no algorithm + +to compute this thing. + +I've never seen a picture +of them, otherwise, + +I'd show it to you. + +So lots of open problems +in making this real. + +But at least the decision +problem is kind of boring. + +You do any gluing. + +It will make a nonconvex thing. + +To find that thing is +still pretty interesting + +question though. + +That's it. \ No newline at end of file diff --git a/P5Ce9tbK86M.txt b/P5Ce9tbK86M.txt new file mode 100644 index 0000000000000000000000000000000000000000..eedb1f03928ebf3592b06b00397cf9fe03eb637e --- /dev/null +++ b/P5Ce9tbK86M.txt @@ -0,0 +1,1854 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: In discussing +the continuous-time and + +discrete-time Fourier +transforms, we developed a + +number of important +properties. + +Two particularly significant +ones, as I mentioned at the + +time, are the modulation +property and + +the convolution property. + +Starting with the next lecture, +the one after this + +one, we'll be developing and +exploiting some of the + +consequences of the modulation +property. + +In today's lecture though, I'd +like to review and expand on + +the notion of filtering, which, +as I had mentioned, + +flows more or less directly from +the convolution property. + +To begin, let me just quickly +review what the convolution + +property is. + +Both for continuous-time and +for discrete-time, the + +convolution property tells us +that the Fourier transform of + +the convolution of two time +functions is the product of + +the Fourier transforms. + +Now, what this means in terms +of linear time-invariant + +filters, since we know that in +the time domain the output of + +a linear time-invariant filter +is the convolution of the + +input and the impulse response, +it says essentially + +then in the frequency domain +that the Fourier transform of + +the output is the product the +Fourier transform of the + +impulse response, namely the +frequency response, and the + +Fourier transform +of the input. + +So the output is described +through that product. + +Now, recall also that in +developing the Fourier + +transform, I interpreted the +Fourier transform as the + +complex amplitude of a +decomposition of the signal in + +terms of a set of complex +exponentials. + +And the frequency response or +the convolution property, in + +effect, tells us how to modify +the amplitudes of each of + +those complex exponentials as +they go through the system. + +Now, this led to the notion of +filtering, where the basic + +concept was that since we can +modify the amplitudes of each + +of the complex exponential +components separately, we can, + +for example, retain +some of them and + +totally eliminate others. + +And this is the basic +notion of filtering. + +So we have, as you recall, first +of all the notion in + +continuous-time of an ideal +filter, for example, I + +illustrate here an ideal lowpass +filter where we pass + +exactly frequency components in +one band and reject totally + +frequency components +in another band. + +The band being passed, of +course, referred to as the + +passband, and the band rejected +as the stopband. + +I illustrated here +a lowpass filter. + +We can, of course, reject the +low frequencies and retain the + +high frequencies. + +And that then corresponds to +an ideal highpass filter. + +Or we can just retain +frequencies within a band. + +And so I show below what is +referred to commonly as a + +bandpass filter. + +Now, this is what the ideal +filters looked like for + +continuous-time. + +For discrete-time, we have +exactly the same situation. + +Namely, we have an ideal +discrete-time lowpass filter, + +which passes exactly frequencies +which are the low + +frequencies. + +Low frequencies, of course, +being around 0, and because of + +the periodicity, also +around 2pi. + +We show also an ideal +highpass filter. + +And a highpass filter, as I +indicated last time, passes + +frequencies around pi. + +And finally, below that, I show +an ideal bandpass filter + +passing frequencies someplace in +the range between 0 and pi. + +And recall also that the basic +difference between + +continuous-time a discrete-time +for these + +filters is that the +discrete-time versions are, of + +course, periodic in frequency. + +Now, let's look at these ideal +filters, and in particular the + +ideal lowpass filter +in the time domain. + +We have the frequency response +of the ideal lowpass filter. + +And shown below it is the +impulse response. + +So here is the frequency +response and below it the + +impulse response of the +ideal lowpass filter. + +And this, of course, +is a sine x over x + +form of impulse response. + +And recognize also or recall +that since this frequency + +response is real-valued, the +impulse response, in other + +words, the inverse transform is +an even function of time. + +And notice also, since I want +to refer back to this, that + +the impulse response of an ideal +lowpass filter, in fact, + +is non-causal. + +That follows, from among other +things, from the fact that + +it's an even function. + +But keep in mind, in fact, that +a sine x over x function + +goes off to infinity +in both directions. + +So the impulse response of the +ideal lowpass filter is + +symmetric and continues to have +tails off to plus and + +minus infinity. + +Now, the situation is basically +the same in the + +discrete-time case. + +Let's look at the frequency +response and associated + +impulse response for an ideal +discrete-time lowpass filter. + +So once again, here is the +frequency response of the + +ideal lowpass filter. + +And below what I show the +impulse response. + +Again, it's a sine x over x +type of impulse response. + +And again, we recognize that +since in the frequency domain, + +this frequency response +is real-valued. + +That means, as a consequence +of the properties of the + +Fourier transform and inverse +Fourier transform, that the + +impulse response is an even +function in the time domain. + +And also, incidentally, the sine +x over x function goes + +off to infinity, again, +in both directions. + +Now, we've talked about ideal +filters in this discussion. + +And ideal filters all +are, in fact, ideal + +in a certain sense. + +What they do ideally is they +pass a certain band of + +frequencies exactly and +they reject a band + +of frequencies exactly. + +On the other hand, there are +many filtering problems in + +which, generally, we don't +have a sharp distinction + +between the frequencies we +want to pass and the + +frequencies we want to reject. + +One example of this that's +elaborated on in the text is + +the design of an automotive +suspension system, which, in + +fact, is the design of +a lowpass filter. + +And basically what you want to +do in a case like that is + +filter out or attenuate very +rapid road variations and keep + +the lower variations in, of +course, elevation of the + +highway or road. + +And what you can see intuitively +is that there + +isn't really a very sharp +distinction or sharp cut-off + +between what you would logically +call the low + +frequencies and what you would +call the high frequencies. + +Now, also somewhat related to +this is the fact that as we've + +seen in the time domain, these +ideal filters have a very + +particular kind of character. + +For example, let's look back at +the ideal lowpass filter. + +And we saw the impulse +response. + +The impulse response is what +we had shown here. + +Let's now look at the step +response of the discrete-time + +ideal lowpass filter. + +And notice the fact that it has +a tail that oscillates. + +And when the step hits, +in fact, it has + +an oscillatory behavior. + +Now, exactly the same +situation occurs in + +continuous-time. + +Let's look at the step +response of the + +continuous-time ideal +lowpass filter. + +And what we see is that when a +step hits then, in fact, we + +get an oscillation. + +And very often, that oscillation +is something + +that's undesirable. + +For example, if you were +designing an automotive + +suspension system and you hit +a curve, which is a step + +input, in fact, you probably +would not like to have the + +automobile oscillating, dying +down in oscillation. + +Now there's another very +important point, which again, + +we can see either in +continuous-time or + +discrete-time, which is that +even if we want it to have an + +ideal filter, the ideal filter +has another problem if we want + +to attempt to implement +it in real time. + +What's the problem? + +The problem is that since the +impulse response is even and, + +in fact, has tails that go off +to plus and minus infinity, + +it's non-causal. + +So if, in fact, we want to build +a filter and the filter + +is restricted to operate in real +time, then, in fact, we + +can't build an ideal filter. + +So what that says is that, in +practice, although ideal + +filters are nice to think about +and perhaps relate to + +practical problems, more +typically what we consider are + +nonideal filters and in the +discrete-time case, a nonideal + +filter then we would have a +characteristic somewhat like + +I've indicated here. + +Where instead of a very rapid +transition from passband to + +stopband, there would be a more +gradual transition with a + +passband cutoff frequency and +a stopband cutoff frequency. + +And perhaps also instead of +having an exactly flat + +characteristic in the stopband +in the passband, we would + +allow a certain amount +of ripple. + +We also have exactly the same +situation in continuous-time, + +where here we'll just simply +change our frequency axis to a + +continuous frequency axis +instead of the discrete + +frequency axis. + +Again, we would think in terms +of an allowable passband + +ripple, a transition from +passband to stopband with a + +passband cutoff frequency and +a stopband cutoff frequency. + +So the notion here is that, +again, ideal filters are ideal + +in some respects, not ideal +in other respects. + +And for many practical +problems, we + +may not want them. + +And even if we did want them, +we may not be able to get + +them, perhaps because of this +issue of causality. + +Even if causality is not an +issue, what happens in filter + +design and implementation, in +fact, is that the sharper you + +attempt to make the cutoff, the +more expensive, in some + +sense, the filter becomes, +either in terms of components, + +in continuous-time, or in +terms of computation in + +discrete-time. + +And so there are these whole +variety of issues that really + +make it important to +understand the + +notion nonideal filters. + +Now, just to illustrate as an +example, let me remind you of + +one example of what, in fact, is +a nonideal lowpass filter. + +And we have looked previously +at the associated + +differential equation. + +Let me now, in fact, relate +it to a circuit, and in + +particular an RC circuit, where +the output could either + +be across the capacitor +or the output can + +be across the resistor. + +So in effect, we have +two systems here. + +We have a system, which is the +system function from the + +voltage source input to the +capacitor output, the system + +from the voltage source input +to the resistor output. + +And, in fact, just applying +Kirchhoff's Voltage Law to + +this, we can relate those in +a very straightforward way. + +It's very straightforward to +verify that the system from + +input to resistor output is +simply the identity system + +with the capacitor output +subtracted from it. + +Now, we can write the +differential equation for + +either of these systems and, as +we talked about last time + +in the last several lectures, +solve that equation using and + +exploiting the properties of +the Fourier transform. + +And in fact, if we look at the +differential equation relating + +the capacitor output to the +voltage source input, we + +recognize that this is an +example that, in effect, we've + +solved previously. + +And so just working our way +down, applying the Fourier + +transform to the differential +equation and generating the + +system function by taking the +ratio of the capacitor voltage + +or its Fourier transform to the +Fourier transform of the + +source, we then have the system +function associated + +with the system for which +the output is + +the capacitor voltage. + +Or if we solve instead for the +system function associated + +with the resistor output, +we can simply + +subtract H1 from unity. + +And the system function that +we get in that case is the + +system function that +I show here. + +So we have, now, two system +functions, one for the + +capacitor output, the other +for the resistor output. + +And one, the first, +corresponding to the capacitor + +output, in fact, if we plot it +on a linear amplitude scale, + +looks like this. + +And as you can see, and as +we saw last time, is an + +approximation to a +lowpass filter. + +It is, in fact, and nonideal +lowpass filter, whereas the + +resistor output is an +approximation to a highpass + +filter, or in effect, a nonideal +highpass filter. + +So in one case, just comparing +the two, we have a lowpass + +filter as the capacitor output +associated with the capacitor + +output, and a highpass filter +associated with + +the resistor output. + +Let's just quickly look at that +example now, looking on a + +Bode plot, instead of +on the linear scale + +that we showed before. + +And recall incidentally, and be +aware incidentally, of the + +fact that we can, of course, +cascade several filters of + +this type and improve +the characteristics. + +So I have shown at the top +a Bode plot of the system + +function associated with +the capacitor output. + +It's flat out to a frequency +corresponding to 1 over the + +time constant, RC. + +And then it falls off at 10 dB +per decade, a decade being a + +factor of 10. + +Or if instead we look at the +system function associated + +with the resistor output, that +corresponds to a 10 dB per + +decade increase in frequency +up to approximately the + +reciprocal of the time constant, +and then approaching + +a flat characteristic +after that. + +And if we consider either one +of these, looking back again + +at the lowpass filter, if we +were to cascade several + +filters with this frequency +response, then because we have + +things plotted on a Bode plot, +the Bode plot for the cascade + +would simply be summing these. + +And so if we cascaded, for +example, two stages instead of + +a roll-off at 10 dB per decade, +it would roll off at + +20 dB per decade. + +Now, filters in this type, RC +filters, perhaps several of + +them in cascade, are in +fact very prevalent. + +And in fact, in an environment +like this, where we're, in + +fact, doing recording, we see +there are filters of that type + +that show up very commonly +both in the audio and the + +video portion of the signal +processing that's associated + +with making this set of tapes. + +In fact, let's take a look +in the control room. + +And what I'll be able to show +you in the control room is the + +audio portion of the processing +that's done and the + +kinds of filters, very much of +the type we just talked about, + +that are associated with the +signal processing that's done + +in preparing the audio +for the tapes. + +So let's just take a walk +into the control room + +and see what we see. + +This is the control room that's + +used for camera switching. + +It's used for computer editing +and also audio control. + +You can see the monitors, +and these are used + +for the camera switching. + +And this is the computer editing +console that's used + +for online and offline +computer editing. + +What I really want to +demonstrate though, in the + +context of the lecture is the +audio control panel, which + +contains, among other things, a +variety of filters for high + +frequency, low frequencies, +et cetera, basically + +equalization filters. + +And what we have in the way of +filtering is, first of all, + +what's referred to as a graphic +equalizer, which + +consists of a set of bandpass +filters, which I'll describe a + +little more carefully +in a minute. + +And then also, an audio control +panel, which is down + +here and which contains separate +equalizer circuits + +for each of a whole set of +channels and also lots of + +controls on them. + +Well, let me begin in the +demonstration by demonstrating + +a little bit of what the +graphic equalizer does. + +Well, what we have is a set +of bandpass filters. + +And what's indicated up here are +the center frequencies of + +the filters, and then a slider +switch for each one that lets + +us attenuate or amplify. + +And this is a dB scale. + +So essentially, if you look +across this bank of filters + +with the total output of the +equalizer just being the sum + +of the outputs from each of +these filters, interestingly + +the position of the slider +switches as you move across + +here, in effect, shows you what +the frequency response of + +the equalizer is. + +So you can change the overall +shaping of the filter by + +moving the switches +up and down. + +Right now the equalizer +is out. + +Let's put the equalizer +into the circuit. + +And now I put in this filtering +characteristic. + +And what I'd like to demonstrate +is filtering with + +this, when we do things that +are a little more dramatic + +than what would normally be +done in a typical audio + +recording setting. + +And to do this, let's add to my +voice some music to make it + +more interesting. + +Not that my voice isn't +interesting as it is. + +But in any case, let's +bring some music up. + +[MUSIC PLAYING] + +And now what I'll do is set +the low frequencies flat. + +And let me take out the high +frequencies above 800 cycles. + +And so now what we have, +effectively, + +is a lowpass filter. + +And now with the lowpass filter, +let me now bring the + +highs back up. + +And so I'm bringing up those +bandpass filters. + +And now let me cut +out the lows. + +And you'll hear the lows +disappearing and, in effect, + +keeping the highs in effectively +crispens the + +sound, either my voice +or the music. + +And finally, let me go back to +0 dB equalization on each of + +the filters. + +And what I'll also do now is +take the equalizer out of the + +circuit totally. + +Now, let's take a look at the +audio master control panel. + +And this panel has, of course, +for each channel and, for + +example, the channel +that we're working + +on, of a volume control. + +I can turn the volume down, and +I can turn the volume up. + +And it also has, for this +particular equalizer circuit, + +it has a set of three bandpass +filters and knobs which let us + +either put in up to 12 dB gain +or 12 dB attenuation in each + +of the bands, and also a +selector switch that lets us + +select the center the band. + +So let me just again +demonstrate a + +little bit with this. + +And let's get a close +up of this panel. + +So what we have, as +I indicated, is + +three bandpass filters. + +And these knobs that I'm +pointing to here are controls + +that allow us for each of the +filters to put in up to 12 dB + +gain or 12 dB attenuation. + +There are also with each of the +filters a selector switch + +that lets us adjust the center +frequency of the filter. + +Basically it's a two-position +switch. + +There also, as you can see, is +a button that let's us either + +put the equalization +in or out. + +Currently the equalization +is out. + +Let's put the equalization in. + +We won't hear any effect from +that, because the gain + +controls are all set at 0 dB. + +And I'll want to illustrate +shortly the effect of these. + +But before I do, let me draw +your attention to one other + +filter, which is this +white switch. + +And this switch is a highpass +filter that essentially cuts + +out frequencies below +about 100 cycles. + +So what it means is that if I +put this switch in, everything + +is more or less flat +above 100 cycles. + +And what that's used for, +basically, is to eliminate + +perhaps 60 cycle noise, if +that's present, or some low + +frequency hum or whatever. + +Well, we won't really +demonstrate + +anything with that. + +Let's [? go ?] now with the +equalization in, demonstrate + +the effect of boosting or +attenuating the low and high + +frequencies. + +And again, I think to +demonstrate this, it + +illustrates the point the +best if we have a + +little background music. + +So maestro, if you can +bring that up. + +[MUSIC PLAYING] + +And so now what I'm going to +do is first boost the low + +frequencies. + +And that's what this +potentiometer knob will do. + +So now, increasing the low +frequency gain and, in fact, + +all the way up to 12 dB when I +have the knob over as far as + +I've gone here. + +And so that has a very +bassy sound. + +And in fact, we can make it +even bassier by taking the + +high frequencies and attenuating +those by 12 dB. + +OK well, let's put some of the +high frequencies back in. + +And now let's turn the +low-frequency gain first + +back down to 0. + +And now we're back to +flat equalization. + +And now I can turn the low +frequency gain down so that I + +attenuate the low frequencies +by much as 12 dB. + +And that's where we are now. + +And so this has, of course, +a much crisper sound. + +And to enhance the highs even +more, I can, in addition to + +cutting out the lows, boost +the highs by putting in, + +again, as much as 12 dB. + +OK well, let's turn down the +music now and go back to no + +equalization by setting +these knobs to 0 dB. + +And in fact, we can take +the equalizer out. + +Well, that's a quick look at +some real-world filters. + +Now let's stop having so +much fun, and let's + +go back to the lecture. + +OK well, that's a little +behind-the-scenes look. + +What I'd like to do now is +turn our attention to + +discrete-time filters. + +And as I've meant in previous +lectures, there are basically + +two classes of discrete-time +filters or discrete-time + +difference equations. + +One class is referred to a +non-recursive or moving + +average filter. + +And the basic idea with a +moving average filter is + +something that perhaps you're +somewhat familiar with + +intuitively. + +Think of the notion of taking +a data sequence, and let's + +suppose that what we wanted to +do was apply some smoothing to + +the data sequence. + +We could, for example, think +of taking adjacent points, + +averaging them together, and +then moving that average along + +the data sequence. + +And what you can kind of see +intuitively is that that would + +apply some smoothing. + +So in fact, the difference +equation, let's say, for + +three-point moving average +would be the difference + +equation that I indicate here, +just simply taking a data + +point and the two data points +adjacent to it and forming an + +average of those three. + +So if we thought of the +processing involved, if we're + +forming an output sequence +value, we would take three + +adjacent points and +average them. + +That would give us the output +add the associated time. + +And then to compute the next +output point, we would just + +simply slide this by one point, +average these together, + +and that would give us the +next output point. + +And we would continue along, +just simply sliding and + +averaging to form the output +data sequence. + +Now, that's an example of what's +commonly referred to a + +three-point moving average. + +In fact, we can generalize +that notion + +in a number of ways. + +One way of generalizing the +notion of a moving average + +from the three-point moving +average, which I summarize + +again here, is to think of +extending that to a larger + +number of points, and in fact +applying weights to that as I + +indicated here, so that, in +addition to just summing up + +the points and dividing by the +number of points summed, we + +can, in fact, apply individual +weights to the points so that + +it's what is often referred to +as a weighting moving average. + +And I show below one possible +curve that might result, where + +these would be essentially the +weights associated with this + +weighted moving average. + +And in fact, it's easy to +verify that this indeed + +corresponds to the impulse +response of the filter. + +Well, just to cement this +notion, let me show you an + +example or two. + +Here is an example of a +five-point moving average. + +A five-point moving average +would have an impulse response + +that just consists of a +rectangle of length five. + +And if this is convolved with +a data sequence, that would + +correspond to taking five +adjacent points and, in + +effect, averaging them. + +We've looked previously at the +Fourier transform of this + +rectangular sequence. + +And the Fourier transform of +that, in fact, is of the form + +of a sine n x over +sine x curve. + +And as you can see, that is +some approximation to a + +lowpass filter. + +And so this, again, is the +impulse response and frequency + +response of a nonideal +lowpass filter. + +Now, there are a variety of +algorithms that, in fact, tell + +you how to choose the weights +associated with a weighted + +moving average to, in some +sense, design better + +approximations and without going +into the details of any + +of those algorithms. + +Let me just show the result of +choosing the weights for the + +design of a 251-point moving +average filter, where the + +weights are chosen using an +optimum algorithm to generate + +as sharp a cutoff as can +possibly be generated. + +And so what I show here is the +frequency response of the + +resulting filter on a +logarithmic amplitude scale + +and a linear frequency scale. + +Notice that on this scale, the +passband is very flat. + +Although here is an expanded +view of it. + +And in fact, it has what's +referred to as an equal-ripple + +characteristic. + +And then here is the +transition band. + +And here we have to stopband, +which in fact is down somewhat + +more than 80 dB and, again, has +what's referred to as an + +equal-ripple characteristic. + +Now, the notion of a moving +average for filtering is + +something that is very +commonly used. + +I had shown last time actually +the result of some filtering + +on a particular data +sequence, the Dow + +Jones Industrial Average. + +And very often, in looking at +various kinds of stock market + +publications, what you will see +is the Dow Jones average + +shown in its raw form +as a data sequence. + +And then very typically, you'll +see also the result of + +a moving average, where the +moving average might be on the + +order of day, or it might be +on the order of months. + +The whole notion being to take +some of the random high + +frequency fluctuations out of +the average and show the low + +frequency, or trends, over +some period of time. + +So let's, in fact, go back +to the Dow Jones average. + +And let me now show you what the +result of filtering with a + +moving average filter would +look like on the same Dow + +Jones industrial average +sequence that + +I showed last time. + +So once again, we have the Dow +Jones average from 1927 to + +roughly 1932. + +At the top, we see the +impulse response + +for the moving average. + +Again, I remind you on an +expanded time scale, and + +what's shown here is +the moving average + +with just one point. + +So the output on the bottom +trace is just simply identical + +to the input. + +Now, let's increase the +length of the moving + +average to two points. + +And we see that there is a small +amount of smoothing, + +three points and just +a little more + +smoothing, that gets inserted. + +Now a four-point moving +average, and next the + +five-point moving average, +and a six-point + +moving average next. + +And we see that the smoothing +increases. + +Now, let's increase the length +of the moving average filter + +much more rapidly and watch +how the output is more and + +more smooth in relation +to the input. + +Again, I emphasize that the +time scale for the impulse + +response is significantly +expanded in relationship to + +the time scale for both the +input and the output. + +And once again, through the +magic of filtering, we've been + +able to eliminate the 1929 +Stock Market Crash. + +All right, so we've seen moving +average filters, or + +what are sometimes referred to +as non-recursive filters. + +And they are, as I stressed, +a very important class of + +discrete-time filters. + +Another very important class of +discrete-time filters are + +what are referred to as +recursive filters. + +Recursive filters are filters +for which the difference + +equation has feedback from the +output back into the input. + +In other words, the output +depends not only on the input, + +but also on previous values +of the output. + +So for example, as I've +stressed previously, a + +recursive difference equation +has the general form that I + +indicate here, a linear +combination of weighted + +outputs on the left-hand side +and linear combination of + +weighted inputs on the +right-hand side. + +And as we've talked about, we +can solve this equation for + +the current output y of n in +terms of current and past + +inputs and past outputs. + +For example, just to interpret +this, focus on the + +interpretation of this as a +filter, let's look at a first + +order difference equation, which +we've talked about and + +generated the solution +to previously. + +So the first order difference +equation would be as I + +indicated here. + +And imposing causality on this, +so that we assume that + +we are running this as a +recursive forward in time, we + +can solve this for y of n in +terms of x of n and y of n + +minus 1 weighted by +the factor a. + +And I simply indicate the +block diagram for this. + +But what we want to examine +now for this first order + +recursion is the frequency +response and see its + +interpretation as a filter. + +Well in fact, again, the +mathematics for this we've + +gone through in the +last lecture. + +And so interpreting the first +order difference equation as a + +system, what we're attempting +to generate is the frequency + +response, which is the +Fourier transform + +of the impulse response. + +And from the difference +equation, we can, of course, + +solve for either one of those +by using the properties, + +exploiting the properties, +of Fourier transform. + +Applying the Fourier transform +to the difference equation, we + +will end up with the Fourier +transform of the output equal + +to the Fourier transform of the +input times this factor, + +which we know from the +convolution property, in fact, + +is the frequency response +of the system. + +So this is the frequency +response. + +And of course, the inverse +Fourier transform of that, + +which I indicate below, is the +system impulse response. + +So we have the frequency +response obtained by applying + +the Fourier transform to the +difference equation, the + +impulse response. + +And, as we did last time, we can +look at that in terms of a + +frequency response +characteristic. + +And recall that, depending on +whether the factor a is + +positive or negative, we either +get a lowpass filter or + +a highpass filter. + +And if, in fact, we look at the +frequency response for the + +factor a being positive, then +we see that this is an + +approximation to a lowpass +filter, whereas below it I + +show the frequency response +for a negative. + +And there this corresponds to +a highpass filter, because + +we're attenuating low +frequencies and retaining the + +high frequencies. + +And recall also that +we illustrated this + +characteristic as a lowpass or +highpass filter for the first + +order recursion by looking at +how it worked as a filter in + +both cases when the input was +the Dow Jones average. + +And indeed, we saw that it +generated both lowpass and + +highpass filtering in the +appropriate cases. + +So for discrete-time, we have +the two classes, moving + +average and recursive filters. + +And there are a variety of +issues discussed in the text + +about why, in certain contexts, +one might want to + +use one of the other. + +Basically, what happens is that +for the moving average + +filter, for a given set a filter +specifications, there + +are many more multiplications +required than + +for a recursive filter. + +But there are, in certain +contexts, some very important + +compensating benefits for the +moving average filter. + +Now, this concludes, pretty +much, what I want to say in + +detail about filtering, the +concept of filtering, in the + +set of lectures. + +This is only a very quick +glimpse into a very important + +and very rich topic, and one, of +course, that can be studied + +on its own in an considerable +amount of detail. + +As the lectures go on, what +we'll find is that the basic + +concept of filtering, both ideal +and nonideal filtering, + +will be a very important +part of what we do. + +And in particular, beginning +with the next lecture, we'll + +turn to a discussion of +modulation, exploiting the + +property of modulation +as it relates to + +some practical problems. + +And what we'll find when we do +that is that a very important + +part of that discussion and, in +fact, a very important part + +of the use of modulation also +just naturally incorporates + +the concept and properties +of filtering. + +Thank you. \ No newline at end of file diff --git a/PkpRIStmfrE.txt b/PkpRIStmfrE.txt new file mode 100644 index 0000000000000000000000000000000000000000..18f0e0cdbd9f85079a3b76113fe0c6841146deed --- /dev/null +++ b/PkpRIStmfrE.txt @@ -0,0 +1,7099 @@ +align:start position:0% + +okay so let's get + + align:start position:0% +okay so let's get + + + align:start position:0% +okay so let's get +started + + align:start position:0% +started + + + align:start position:0% +started +so as I said I I I'm going to do second + + align:start position:0% +so as I said I I I'm going to do second + + + align:start position:0% +so as I said I I I'm going to do second +derivatives which is just going to be + + align:start position:0% +derivatives which is just going to be + + + align:start position:0% +derivatives which is just going to be +the derivative of the + + align:start position:0% +the derivative of the + + + align:start position:0% +the derivative of the +derivative but you know when you have um + + align:start position:0% +derivative but you know when you have um + + + align:start position:0% +derivative but you know when you have um +functions from you know matrices to + + align:start position:0% +functions from you know matrices to + + + align:start position:0% +functions from you know matrices to +matrices or something like that you have + + align:start position:0% +matrices or something like that you have + + + align:start position:0% +matrices or something like that you have +to think a little bit + + align:start position:0% +to think a little bit + + + align:start position:0% +to think a little bit +carefully just to make sure we + + align:start position:0% +carefully just to make sure we + + + align:start position:0% +carefully just to make sure we +understand what kind of thing the second + + align:start position:0% +understand what kind of thing the second + + + align:start position:0% +understand what kind of thing the second +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +is so remember when we take basically + + align:start position:0% +is so remember when we take basically + + + align:start position:0% +is so remember when we take basically +the the first + + align:start position:0% +the the first + + + align:start position:0% +the the first +derivative right what what we have is + + align:start position:0% +derivative right what what we have is + + + align:start position:0% +derivative right what what we have is +this this linear + + align:start position:0% + + + + align:start position:0% + +operator F primed of X that takes in uh + + align:start position:0% +operator F primed of X that takes in uh + + + align:start position:0% +operator F primed of X that takes in uh +a little + + align:start position:0% +a little + + + align:start position:0% +a little +change right and gives us you know a DF + + align:start position:0% +change right and gives us you know a DF + + + align:start position:0% +change right and gives us you know a DF +which is the the the f of x plus DX + + align:start position:0% +which is the the the f of x plus DX + + + align:start position:0% +which is the the the f of x plus DX +minus F ofx to first order right they + + align:start position:0% +minus F ofx to first order right they + + + align:start position:0% +minus F ofx to first order right they +dropping higher order + + align:start position:0% +dropping higher order + + + align:start position:0% +dropping higher order +terms and so it's really natural you + + align:start position:0% +terms and so it's really natural you + + + align:start position:0% +terms and so it's really natural you +know to define the second + + align:start position:0% + + + + align:start position:0% + +derivative say derive as the derivative + + align:start position:0% +derivative say derive as the derivative + + + align:start position:0% +derivative say derive as the derivative +of that so what + + align:start position:0% +of that so what + + + align:start position:0% +of that so what +should what what should uh uh um + + align:start position:0% +should what what should uh uh um + + + align:start position:0% +should what what should uh uh um +F Prim + + align:start position:0% + + + + align:start position:0% + +B right F + + align:start position:0% +B right F + + + align:start position:0% +B right F +primed of uh of + + align:start position:0% +primed of uh of + + + align:start position:0% +primed of uh of +X should take in a that's called let me + + align:start position:0% +X should take in a that's called let me + + + align:start position:0% +X should take in a that's called let me +call it DX Prime that means that's not a + + align:start position:0% +call it DX Prime that means that's not a + + + align:start position:0% +call it DX Prime that means that's not a +derivative just means a different uh let + + align:start position:0% +derivative just means a different uh let + + + align:start position:0% +derivative just means a different uh let +me put it in here a red is it's going to + + align:start position:0% +me put it in here a red is it's going to + + + align:start position:0% +me put it in here a red is it's going to +be a a + + align:start position:0% +be a a + + + align:start position:0% +be a a +different small + + align:start position:0% +different small + + + align:start position:0% +different small +change right so Prime here is not + + align:start position:0% +change right so Prime here is not + + + align:start position:0% +change right so Prime here is not +derivative it's just different okay call + + align:start position:0% +derivative it's just different okay call + + + align:start position:0% +derivative it's just different okay call +it Tilda or something like that but we + + align:start position:0% +it Tilda or something like that but we + + + align:start position:0% +it Tilda or something like that but we +overload the prime a lot in mathematics + + align:start position:0% +overload the prime a lot in mathematics + + + align:start position:0% +overload the prime a lot in mathematics +right so what should it be well it + + align:start position:0% +right so what should it be well it + + + align:start position:0% +right so what should it be well it +should be the derivative I mean it + + align:start position:0% +should be the derivative I mean it + + + align:start position:0% +should be the derivative I mean it +should be exactly the same thing it + + align:start position:0% +should be exactly the same thing it + + + align:start position:0% +should be exactly the same thing it +should be it should be + + align:start position:0% +should be it should be + + + align:start position:0% +should be it should be +DF primed right so it should be FR Prim + + align:start position:0% +DF primed right so it should be FR Prim + + + align:start position:0% +DF primed right so it should be FR Prim +of x uh plus DXE + + align:start position:0% +of x uh plus DXE + + + align:start position:0% +of x uh plus DXE +primed + + align:start position:0% +primed + + + align:start position:0% +primed +minus F primed of + + align:start position:0% + + + + align:start position:0% + +X it should look exactly the same but + + align:start position:0% +X it should look exactly the same but + + + align:start position:0% +X it should look exactly the same but +now let's think about what this means so + + align:start position:0% +now let's think about what this means so + + + align:start position:0% +now let's think about what this means so +this F Prime here is not a number + + align:start position:0% +this F Prime here is not a number + + + align:start position:0% +this F Prime here is not a number +anymore this is it could be a number but + + align:start position:0% +anymore this is it could be a number but + + + align:start position:0% +anymore this is it could be a number but +in general it's a linear operator right + + align:start position:0% +in general it's a linear operator right + + + align:start position:0% +in general it's a linear operator right +so this + + align:start position:0% +so this + + + align:start position:0% +so this +here is the difference of two linear + + align:start position:0% +here is the difference of two linear + + + align:start position:0% +here is the difference of two linear +operators + + align:start position:0% + + + + align:start position:0% + +right and what does it mean to to add + + align:start position:0% +right and what does it mean to to add + + + align:start position:0% +right and what does it mean to to add +and subtract and and take differences of + + align:start position:0% +and subtract and and take differences of + + + align:start position:0% +and subtract and and take differences of +linear operators right and we did a + + align:start position:0% +linear operators right and we did a + + + align:start position:0% +linear operators right and we did a +little bit of this in problem set one + + align:start position:0% +little bit of this in problem set one + + + align:start position:0% +little bit of this in problem set one +you can think of linear operators + + align:start position:0% +you can think of linear operators + + + align:start position:0% +you can think of linear operators +themselves as a vector space right you + + align:start position:0% +themselves as a vector space right you + + + align:start position:0% +themselves as a vector space right you +can just like we can take functions you + + align:start position:0% +can just like we can take functions you + + + align:start position:0% +can just like we can take functions you +know sinx plus cosine X is another + + align:start position:0% +know sinx plus cosine X is another + + + align:start position:0% +know sinx plus cosine X is another +function right so so we can take think + + align:start position:0% +function right so so we can take think + + + align:start position:0% +function right so so we can take think +of linear operators as as as a vector + + align:start position:0% +of linear operators as as as a vector + + + align:start position:0% +of linear operators as as as a vector +space as well so if you have if we have + + align:start position:0% +space as well so if you have if we have + + + align:start position:0% +space as well so if you have if we have +linear + + align:start position:0% +linear + + + align:start position:0% +linear +operators + + align:start position:0% + + + + align:start position:0% + +uh operators + + align:start position:0% +uh operators + + + align:start position:0% +uh operators +operators uh L1 and + + align:start position:0% +operators uh L1 and + + + align:start position:0% +operators uh L1 and +L2 then what we mean by their addition + + align:start position:0% +L2 then what we mean by their addition + + + align:start position:0% +L2 then what we mean by their addition +L1 plus L2 or plus or minus + + align:start position:0% +L1 plus L2 or plus or minus + + + align:start position:0% +L1 plus L2 or plus or minus +is the linear + + align:start position:0% + + + + align:start position:0% + +operator that takes a vector + + align:start position:0% +operator that takes a vector + + + align:start position:0% +operator that takes a vector +v and gives you L1 of + + align:start position:0% +v and gives you L1 of + + + align:start position:0% +v and gives you L1 of +V plus L2 of + + align:start position:0% +V plus L2 of + + + align:start position:0% +V plus L2 of +V right and the same thing if you if you + + align:start position:0% +V right and the same thing if you if you + + + align:start position:0% +V right and the same thing if you if you +multiply a linear Operator by a + + align:start position:0% +multiply a linear Operator by a + + + align:start position:0% +multiply a linear Operator by a +scalar that's the linear + + align:start position:0% + + + + align:start position:0% + +operator that sends a vector v to Alpha + + align:start position:0% +operator that sends a vector v to Alpha + + + align:start position:0% +operator that sends a vector v to Alpha +time L1 one of + + align:start position:0% +time L1 one of + + + align:start position:0% +time L1 one of +V right so so and this this should be + + align:start position:0% +V right so so and this this should be + + + align:start position:0% +V right so so and this this should be +familiar right so if I take two matrices + + align:start position:0% +familiar right so if I take two matrices + + + align:start position:0% +familiar right so if I take two matrices +and I add them you actually know what + + align:start position:0% +and I add them you actually know what + + + align:start position:0% +and I add them you actually know what +that mean you say oh that means you add + + align:start position:0% +that mean you say oh that means you add + + + align:start position:0% +that mean you say oh that means you add +the elements up element wise but where + + align:start position:0% +the elements up element wise but where + + + align:start position:0% +the elements up element wise but where +does that rule come from that adding up + + align:start position:0% +does that rule come from that adding up + + + align:start position:0% +does that rule come from that adding up +two matrices element wise is exactly the + + align:start position:0% +two matrices element wise is exactly the + + + align:start position:0% +two matrices element wise is exactly the +new Matrix that acting on a vector gives + + align:start position:0% +new Matrix that acting on a vector gives + + + align:start position:0% +new Matrix that acting on a vector gives +you the first Matrix times the vector + + align:start position:0% +you the first Matrix times the vector + + + align:start position:0% +you the first Matrix times the vector +plus the second Matrix times a vector + + align:start position:0% +plus the second Matrix times a vector + + + align:start position:0% +plus the second Matrix times a vector +right if I take a matrix and multiply it + + align:start position:0% +right if I take a matrix and multiply it + + + align:start position:0% +right if I take a matrix and multiply it +by three you can say oh you multiply all + + align:start position:0% +by three you can say oh you multiply all + + + align:start position:0% +by three you can say oh you multiply all +the entries by three but why it's + + align:start position:0% +the entries by three but why it's + + + align:start position:0% +the entries by three but why it's +because if I take that's the the linear + + align:start position:0% +because if I take that's the the linear + + + align:start position:0% +because if I take that's the the linear +operator that taking a takes a vector + + align:start position:0% +operator that taking a takes a vector + + + align:start position:0% +operator that taking a takes a vector +it's equivalent to multiplying it by + + align:start position:0% +it's equivalent to multiplying it by + + + align:start position:0% +it's equivalent to multiplying it by +that M original Matrix and then + + align:start position:0% +that M original Matrix and then + + + align:start position:0% +that M original Matrix and then +multiplying by three right so that's + + align:start position:0% +multiplying by three right so that's + + + align:start position:0% +multiplying by three right so that's +where those rules Come From just like + + align:start position:0% +where those rules Come From just like + + + align:start position:0% +where those rules Come From just like +the rule for multiplying two matrices oh + + align:start position:0% +the rule for multiplying two matrices oh + + + align:start position:0% +the rule for multiplying two matrices oh +rows times columns why because that's + + align:start position:0% +rows times columns why because that's + + + align:start position:0% +rows times columns why because that's +the new M that's the new linear operator + + align:start position:0% +the new M that's the new linear operator + + + align:start position:0% +the new M that's the new linear operator +that equivalent to multiplying by the + + align:start position:0% +that equivalent to multiplying by the + + + align:start position:0% +that equivalent to multiplying by the +first Matrix by the right Matrix and + + align:start position:0% +first Matrix by the right Matrix and + + + align:start position:0% +first Matrix by the right Matrix and +then by the left Matrix right that's + + align:start position:0% +then by the left Matrix right that's + + + align:start position:0% +then by the left Matrix right that's +where these rules Come From right so + + align:start position:0% +where these rules Come From right so + + + align:start position:0% +where these rules Come From right so +this thing here + + align:start position:0% +this thing here + + + align:start position:0% +this thing here +is is now so what we really mean by this + + align:start position:0% +is is now so what we really mean by this + + + align:start position:0% +is is now so what we really mean by this +is + + align:start position:0% +is + + + align:start position:0% +is +this is a linear + + align:start position:0% +this is a linear + + + align:start position:0% +this is a linear +operator right + + align:start position:0% + + + + align:start position:0% + +so right that this is the difference of + + align:start position:0% +so right that this is the difference of + + + align:start position:0% +so right that this is the difference of +two linear operators this is these are + + align:start position:0% +two linear operators this is these are + + + align:start position:0% +two linear operators this is these are +linear operators that take in a DX and + + align:start position:0% +linear operators that take in a DX and + + + align:start position:0% +linear operators that take in a DX and +give you something else give you a DF + + align:start position:0% +give you something else give you a DF + + + align:start position:0% +give you something else give you a DF +right so the difference of these two + + align:start position:0% +right so the difference of these two + + + align:start position:0% +right so the difference of these two +things is a linear operator that takes + + align:start position:0% +things is a linear operator that takes + + + align:start position:0% +things is a linear operator that takes +in a DX not a DX prime a DX and gives + + align:start position:0% +in a DX not a DX prime a DX and gives + + + align:start position:0% +in a DX not a DX prime a DX and gives +you uh and gives you something else so + + align:start position:0% +you uh and gives you something else so + + + align:start position:0% +you uh and gives you something else so +this is this is a linear operator that + + align:start position:0% +this is this is a linear operator that + + + align:start position:0% +this is this is a linear operator that +takes in we can call it uh F Prim right + + align:start position:0% +takes in we can call it uh F Prim right + + + align:start position:0% +takes in we can call it uh F Prim right +uh of X it takes in a DX + + align:start position:0% +uh of X it takes in a DX + + + align:start position:0% +uh of X it takes in a DX +Prime that takes in so another input we + + align:start position:0% +Prime that takes in so another input we + + + align:start position:0% +Prime that takes in so another input we +can take it write it as it takes in an + + align:start position:0% +can take it write it as it takes in an + + + align:start position:0% +can take it write it as it takes in an +input + + align:start position:0% +input + + + align:start position:0% +input +DX + + align:start position:0% +DX + + + align:start position:0% +DX +oops and what it gives you is frim of x + + align:start position:0% +oops and what it gives you is frim of x + + + align:start position:0% +oops and what it gives you is frim of x ++ DX + + align:start position:0% + + + + align:start position:0% + +Prim uh acting + + align:start position:0% +Prim uh acting + + + align:start position:0% +Prim uh acting +on + + align:start position:0% + + + + align:start position:0% + +DX + + align:start position:0% +DX + + + align:start position:0% +DX +minus minus fime of X acting on + + align:start position:0% + + + + align:start position:0% + +DX does everyone see so so so this F + + align:start position:0% +DX does everyone see so so so this F + + + align:start position:0% +DX does everyone see so so so this F +Prime is going to be it's just copying + + align:start position:0% +Prime is going to be it's just copying + + + align:start position:0% +Prime is going to be it's just copying +down the formula for the for the + + align:start position:0% +down the formula for the for the + + + align:start position:0% +down the formula for the for the +derivative except applying it to F Prime + + align:start position:0% +derivative except applying it to F Prime + + + align:start position:0% +derivative except applying it to F Prime +but then so this is the the linear + + align:start position:0% +but then so this is the the linear + + + align:start position:0% +but then so this is the the linear +operator you get when you take the + + align:start position:0% +operator you get when you take the + + + align:start position:0% +operator you get when you take the +original linear operator at F at a + + align:start position:0% +original linear operator at F at a + + + align:start position:0% +original linear operator at F at a +slightly shifted x minus minus frime of + + align:start position:0% +slightly shifted x minus minus frime of + + + align:start position:0% +slightly shifted x minus minus frime of +X so this is a linear operator that X on + + align:start position:0% +X so this is a linear operator that X on + + + align:start position:0% +X so this is a linear operator that X on +DX and what it does is it's just the + + align:start position:0% +DX and what it does is it's just the + + + align:start position:0% +DX and what it does is it's just the +linear operator that takes this on DX + + align:start position:0% +linear operator that takes this on DX + + + align:start position:0% +linear operator that takes this on DX +minus this on DX but then if you think + + align:start position:0% +minus this on DX but then if you think + + + align:start position:0% +minus this on DX but then if you think +about this object now this object now + + align:start position:0% +about this object now this object now + + + align:start position:0% +about this object now this object now +takes two + + align:start position:0% +takes two + + + align:start position:0% +takes two +inputs right it takes the change it + + align:start position:0% +inputs right it takes the change it + + + align:start position:0% +inputs right it takes the change it +takes the change in X you know where DX + + align:start position:0% +takes the change in X you know where DX + + + align:start position:0% +takes the change in X you know where DX +Prime is a change in where you're taking + + align:start position:0% +Prime is a change in where you're taking + + + align:start position:0% +Prime is a change in where you're taking +the derivative right and then the second + + align:start position:0% +the derivative right and then the second + + + align:start position:0% +the derivative right and then the second +one DX is the change you know in X that + + align:start position:0% +one DX is the change you know in X that + + + align:start position:0% +one DX is the change you know in X that +you're acting the derivative f primed on + + align:start position:0% +you're acting the derivative f primed on + + + align:start position:0% +you're acting the derivative f primed on +right so this is called a bilinear + + align:start position:0% + + + + align:start position:0% + +form right so we have we're going to + + align:start position:0% +form right so we have we're going to + + + align:start position:0% +form right so we have we're going to +have F + + align:start position:0% +have F + + + align:start position:0% +have F +primed that's taking of X that takes two + + align:start position:0% + + + + align:start position:0% + +inputs DX + + align:start position:0% +inputs DX + + + align:start position:0% +inputs DX +Prime and + + align:start position:0% +Prime and + + + align:start position:0% +Prime and +DX but writing those two pairs of + + align:start position:0% +DX but writing those two pairs of + + + align:start position:0% +DX but writing those two pairs of +brackets is a little bit annoying so let + + align:start position:0% +brackets is a little bit annoying so let + + + align:start position:0% +brackets is a little bit annoying so let +me just write one pair of brackets and + + align:start position:0% +me just write one pair of brackets and + + + align:start position:0% +me just write one pair of brackets and +just give it two + + align:start position:0% + + + + align:start position:0% + +arguments right and so it acts on two + + align:start position:0% + + + + align:start position:0% + +vectors and it's linear in + + align:start position:0% +vectors and it's linear in + + + align:start position:0% +vectors and it's linear in +both right so in general uh you know + + align:start position:0% +both right so in general uh you know + + + align:start position:0% +both right so in general uh you know +bilinear form + + align:start position:0% + + + + align:start position:0% + +right it say let me just remind you of + + align:start position:0% +right it say let me just remind you of + + + align:start position:0% +right it say let me just remind you of +linearity right you have a bilinear + + align:start position:0% +linearity right you have a bilinear + + + align:start position:0% +linearity right you have a bilinear +form form you know call it B that takes + + align:start position:0% +form form you know call it B that takes + + + align:start position:0% +form form you know call it B that takes +in a vector U and it takes in a vector v + + align:start position:0% +in a vector U and it takes in a vector v + + + align:start position:0% +in a vector U and it takes in a vector v +right with and and + + align:start position:0% +right with and and + + + align:start position:0% +right with and and +linearity means if you take like B of U1 + + align:start position:0% +linearity means if you take like B of U1 + + + align:start position:0% +linearity means if you take like B of U1 ++ U2 that had oops comma V that had + + align:start position:0% ++ U2 that had oops comma V that had + + + align:start position:0% ++ U2 that had oops comma V that had +better equal + + align:start position:0% +better equal + + + align:start position:0% +better equal +B of U1 + + align:start position:0% +B of U1 + + + align:start position:0% +B of U1 +V plus b of U2 V but it also has to be + + align:start position:0% +V plus b of U2 V but it also has to be + + + align:start position:0% +V plus b of U2 V but it also has to be +linear in the second argument B of U V1 + + align:start position:0% +linear in the second argument B of U V1 + + + align:start position:0% +linear in the second argument B of U V1 +plus + + align:start position:0% +plus + + + align:start position:0% +plus +V2 has to equal B of U V1 plus b of U + + align:start position:0% +V2 has to equal B of U V1 plus b of U + + + align:start position:0% +V2 has to equal B of U V1 plus b of U +V2 Etc right you can also scale the and + + align:start position:0% +V2 Etc right you can also scale the and + + + align:start position:0% +V2 Etc right you can also scale the and +multiply one of the arguments by two and + + align:start position:0% +multiply one of the arguments by two and + + + align:start position:0% +multiply one of the arguments by two and +so forth right if I multiply both of the + + align:start position:0% +so forth right if I multiply both of the + + + align:start position:0% +so forth right if I multiply both of the +arguments by two if I I do + + align:start position:0% +arguments by two if I I do + + + align:start position:0% +arguments by two if I I do +B uh if I do B of like 2 U * 3 V right + + align:start position:0% +B uh if I do B of like 2 U * 3 V right + + + align:start position:0% +B uh if I do B of like 2 U * 3 V right +that had better be 2 * 3 uh B of UV + + align:start position:0% +that had better be 2 * 3 uh B of UV + + + align:start position:0% +that had better be 2 * 3 uh B of UV +right so if I multiply both arguments by + + align:start position:0% +right so if I multiply both arguments by + + + align:start position:0% +right so if I multiply both arguments by +two it doesn't multiply the output by + + align:start position:0% +two it doesn't multiply the output by + + + align:start position:0% +two it doesn't multiply the output by +two it multiplies it by + + align:start position:0% + + + + align:start position:0% + +four + + align:start position:0% +four + + + align:start position:0% +four +so so that's what this second derivative + + align:start position:0% +so so that's what this second derivative + + + align:start position:0% +so so that's what this second derivative +is it takes in a change a two changes + + align:start position:0% +is it takes in a change a two changes + + + align:start position:0% +is it takes in a change a two changes +right A change in where you're taking + + align:start position:0% +right A change in where you're taking + + + align:start position:0% +right A change in where you're taking +the derivative and a change in the thing + + align:start position:0% +the derivative and a change in the thing + + + align:start position:0% +the derivative and a change in the thing +that you're taking the derivative + + align:start position:0% +that you're taking the derivative + + + align:start position:0% +that you're taking the derivative +on and you might wonder if it if it if + + align:start position:0% +on and you might wonder if it if it if + + + align:start position:0% +on and you might wonder if it if it if +it matters like the order oops and I + + align:start position:0% +it matters like the order oops and I + + + align:start position:0% +it matters like the order oops and I +this should not have been a + + align:start position:0% +this should not have been a + + + align:start position:0% +this should not have been a +prime okay if it matters does the order + + align:start position:0% +prime okay if it matters does the order + + + align:start position:0% +prime okay if it matters does the order +of these two things matter and in + + align:start position:0% +of these two things matter and in + + + align:start position:0% +of these two things matter and in +general for bilinear forms the order + + align:start position:0% +general for bilinear forms the order + + + align:start position:0% +general for bilinear forms the order +matters in + + align:start position:0% + + + + align:start position:0% + +general for bilinear + + align:start position:0% + + + + align:start position:0% + +forms um + + align:start position:0% +forms um + + + align:start position:0% +forms um +you know B of u v is not equal to B of + + align:start position:0% + + + + align:start position:0% + +v + + align:start position:0% +v + + + align:start position:0% +v +v and and in fact it may not even make + + align:start position:0% +v and and in fact it may not even make + + + align:start position:0% +v and and in fact it may not even make +sense to swap the arguments like you can + + align:start position:0% +sense to swap the arguments like you can + + + align:start position:0% +sense to swap the arguments like you can +have a bilinear form where U lives in + + align:start position:0% +have a bilinear form where U lives in + + + align:start position:0% +have a bilinear form where U lives in +one vector space and V lives in + + align:start position:0% +one vector space and V lives in + + + align:start position:0% +one vector space and V lives in +completely different Vector space like + + align:start position:0% +completely different Vector space like + + + align:start position:0% +completely different Vector space like +so U is a scalar and V is a column + + align:start position:0% +so U is a scalar and V is a column + + + align:start position:0% +so U is a scalar and V is a column +Vector like it doesn't even you can't + + align:start position:0% +Vector like it doesn't even you can't + + + align:start position:0% +Vector like it doesn't even you can't +even uh swap them so I it + + align:start position:0% +even uh swap them so I it + + + align:start position:0% +even uh swap them so I it +this may not even makes + + align:start position:0% +this may not even makes + + + align:start position:0% +this may not even makes +sense but here you know DX and DX Prime + + align:start position:0% +sense but here you know DX and DX Prime + + + align:start position:0% +sense but here you know DX and DX Prime +they clearly live in the same Vector + + align:start position:0% +they clearly live in the same Vector + + + align:start position:0% +they clearly live in the same Vector +space it both changes to X and so it do + + align:start position:0% +space it both changes to X and so it do + + + align:start position:0% +space it both changes to X and so it do +you could swap them and ask what's the + + align:start position:0% +you could swap them and ask what's the + + + align:start position:0% +you could swap them and ask what's the +change and in fact but here it turns out + + align:start position:0% +change and in fact but here it turns out + + + align:start position:0% +change and in fact but here it turns out +they are the same so here + + align:start position:0% + + + + align:start position:0% + +for uh + + align:start position:0% +for uh + + + align:start position:0% +for uh +here um it turns out that F primed + + align:start position:0% +here um it turns out that F primed + + + align:start position:0% +here um it turns out that F primed +of DX + + align:start position:0% + + + + align:start position:0% + +primed my color came right fouble I was + + align:start position:0% +primed my color came right fouble I was + + + align:start position:0% +primed my color came right fouble I was +using black right F primed of X right + + align:start position:0% +using black right F primed of X right + + + align:start position:0% +using black right F primed of X right +there's a point at which you're valuing + + align:start position:0% +there's a point at which you're valuing + + + align:start position:0% +there's a point at which you're valuing +the second derivative of DX Prime comma + + align:start position:0% +the second derivative of DX Prime comma + + + align:start position:0% +the second derivative of DX Prime comma +DX always in fact equals F primed of + + align:start position:0% + + + + align:start position:0% + +X DX + + align:start position:0% +X DX + + + align:start position:0% +X DX +comma DX Prime and so this is what's + + align:start position:0% +comma DX Prime and so this is what's + + + align:start position:0% +comma DX Prime and so this is what's +called a + + align:start position:0% + + + + align:start position:0% + +symmetric + + align:start position:0% +symmetric + + + align:start position:0% +symmetric +and we can show it pretty easily just + + align:start position:0% +and we can show it pretty easily just + + + align:start position:0% +and we can show it pretty easily just +from the definition right so so in fact + + align:start position:0% +from the definition right so so in fact + + + align:start position:0% +from the definition right so so in fact +you as I'll show in a minute this is + + align:start position:0% +you as I'll show in a minute this is + + + align:start position:0% +you as I'll show in a minute this is +actually you've seen this kind of thing + + align:start position:0% +actually you've seen this kind of thing + + + align:start position:0% +actually you've seen this kind of thing +before you didn't realize it so you + + align:start position:0% +before you didn't realize it so you + + + align:start position:0% +before you didn't realize it so you +learned in 1802 monly variable calculus + + align:start position:0% +learned in 1802 monly variable calculus + + + align:start position:0% +learned in 1802 monly variable calculus +then when I take a partial derivative + + align:start position:0% +then when I take a partial derivative + + + align:start position:0% +then when I take a partial derivative +like partial F partial X partial y like + + align:start position:0% +like partial F partial X partial y like + + + align:start position:0% +like partial F partial X partial y like +two and I can swap them it doesn't + + align:start position:0% +two and I can swap them it doesn't + + + align:start position:0% +two and I can swap them it doesn't +matter and it turns out that is is going + + align:start position:0% +matter and it turns out that is is going + + + align:start position:0% +matter and it turns out that is is going +to be a special case of this right so so + + align:start position:0% +to be a special case of this right so so + + + align:start position:0% +to be a special case of this right so so +let me let me show it in general from + + align:start position:0% +let me let me show it in general from + + + align:start position:0% +let me let me show it in general from +just from the definition so so why is + + align:start position:0% + + + + align:start position:0% + +this okay why so y + + align:start position:0% + + + + align:start position:0% + +symmetric and so we just we just need to + + align:start position:0% +symmetric and so we just we just need to + + + align:start position:0% +symmetric and so we just we just need to +write out the definition a little bit so + + align:start position:0% +write out the definition a little bit so + + + align:start position:0% +write out the definition a little bit so +just write out FP Prim of + + align:start position:0% +just write out FP Prim of + + + align:start position:0% +just write out FP Prim of +X of DX Prim DX I'm not going to use + + align:start position:0% +X of DX Prim DX I'm not going to use + + + align:start position:0% +X of DX Prim DX I'm not going to use +colors here because it gets too annoying + + align:start position:0% +colors here because it gets too annoying + + + align:start position:0% +colors here because it gets too annoying +to swap swap pens back and forth + + align:start position:0% +to swap swap pens back and forth + + + align:start position:0% +to swap swap pens back and forth +okay so there's there's two terms here + + align:start position:0% +okay so there's there's two terms here + + + align:start position:0% +okay so there's there's two terms here +so there's a term that comes from um FR + + align:start position:0% +so there's a term that comes from um FR + + + align:start position:0% +so there's a term that comes from um FR +Prime of x + DX + + align:start position:0% +Prime of x + DX + + + align:start position:0% +Prime of x + DX +Prime acting on + + align:start position:0% +Prime acting on + + + align:start position:0% +Prime acting on +DX + + align:start position:0% +DX + + + align:start position:0% +DX +minus F + + align:start position:0% +minus F + + + align:start position:0% +minus F +ofx FR Prime of X acting on DX right + + align:start position:0% +ofx FR Prime of X acting on DX right + + + align:start position:0% +ofx FR Prime of X acting on DX right +that's just the definition I did before + + align:start position:0% +that's just the definition I did before + + + align:start position:0% +that's just the definition I did before +right that's the it's it's the F Prime + + align:start position:0% +right that's the it's it's the F Prime + + + align:start position:0% +right that's the it's it's the F Prime +is the difference of these two linear + + align:start position:0% +is the difference of these two linear + + + align:start position:0% +is the difference of these two linear +operators so acting on DX is the + + align:start position:0% +operators so acting on DX is the + + + align:start position:0% +operators so acting on DX is the +difference of what they do on the + + align:start position:0% +difference of what they do on the + + + align:start position:0% +difference of what they do on the +DX but now let's take it one step + + align:start position:0% +DX but now let's take it one step + + + align:start position:0% +DX but now let's take it one step +further I'm going to expand out what's + + align:start position:0% +further I'm going to expand out what's + + + align:start position:0% +further I'm going to expand out what's +the definition of f primed let's go back + + align:start position:0% +the definition of f primed let's go back + + + align:start position:0% +the definition of f primed let's go back +to that frime of of X fim let's do the + + align:start position:0% +to that frime of of X fim let's do the + + + align:start position:0% +to that frime of of X fim let's do the +second one that's easier + + align:start position:0% +second one that's easier + + + align:start position:0% +second one that's easier +right + + align:start position:0% +right + + + align:start position:0% +right +um so the second + + align:start position:0% +um so the second + + + align:start position:0% +um so the second +term what's F Prime of X DX we + + align:start position:0% +term what's F Prime of X DX we + + + align:start position:0% +term what's F Prime of X DX we +said you know very in the very first + + align:start position:0% +said you know very in the very first + + + align:start position:0% +said you know very in the very first +lecture that's the same thing as f ofx + + align:start position:0% +lecture that's the same thing as f ofx + + + align:start position:0% +lecture that's the same thing as f ofx +plus DX minus F ofx right that's what + + align:start position:0% +plus DX minus F ofx right that's what + + + align:start position:0% +plus DX minus F ofx right that's what +that's what that is so + + align:start position:0% +that's what that is so + + + align:start position:0% +that's what that is so +what's what's F Prime of X Plus DX Prime + + align:start position:0% +what's what's F Prime of X Plus DX Prime + + + align:start position:0% +what's what's F Prime of X Plus DX Prime +DX it's f + + align:start position:0% +DX it's f + + + align:start position:0% +DX it's f +of x + DX Prim + DX minus F ofx + + + align:start position:0% + + + + align:start position:0% + +dxr now let me just regroup these terms + + align:start position:0% +dxr now let me just regroup these terms + + + align:start position:0% +dxr now let me just regroup these terms +a little bit so I have one term that + + align:start position:0% +a little bit so I have one term that + + + align:start position:0% +a little bit so I have one term that +looks like f ofx + DX prime plus + + align:start position:0% + + + + align:start position:0% + +DX and I have another term that looks + + align:start position:0% +DX and I have another term that looks + + + align:start position:0% +DX and I have another term that looks +like just a A plus F ofx that's not very + + align:start position:0% +like just a A plus F ofx that's not very + + + align:start position:0% +like just a A plus F ofx that's not very +interesting and then I have another term + + align:start position:0% +interesting and then I have another term + + + align:start position:0% +interesting and then I have another term +that looks like f ofx uh plus DX with + + align:start position:0% +that looks like f ofx uh plus DX with + + + align:start position:0% +that looks like f ofx uh plus DX with +the minus sign and I have another term + + align:start position:0% +the minus sign and I have another term + + + align:start position:0% +the minus sign and I have another term +that looks like f ofx plus DX + + align:start position:0% + + + + align:start position:0% + +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +but now if you stare at this + + align:start position:0% +but now if you stare at this + + + align:start position:0% +but now if you stare at this +clearly vector addition is commutative + + align:start position:0% +clearly vector addition is commutative + + + align:start position:0% +clearly vector addition is commutative +right I can swap those I can swap + + align:start position:0% + + + + align:start position:0% + +these these two two terms so this is + + align:start position:0% +these these two two terms so this is + + + align:start position:0% +these these two two terms so this is +this is I can I can swap the addition in + + align:start position:0% +this is I can I can swap the addition in + + + align:start position:0% +this is I can I can swap the addition in +the input I can also swap the addition + + align:start position:0% +the input I can also swap the addition + + + align:start position:0% +the input I can also swap the addition +of the output I can just arrange these + + align:start position:0% +of the output I can just arrange these + + + align:start position:0% +of the output I can just arrange these +two terms right and so this whole thing + + align:start position:0% +two terms right and so this whole thing + + + align:start position:0% +two terms right and so this whole thing +is exactly what you the same as what you + + align:start position:0% +is exactly what you the same as what you + + + align:start position:0% +is exactly what you the same as what you +would get is if I took F Prime of X and + + align:start position:0% +would get is if I took F Prime of X and + + + align:start position:0% +would get is if I took F Prime of X and +evaluated it at and I swapped the + + align:start position:0% + + + + align:start position:0% + +outputs so it's just just writing out + + align:start position:0% +outputs so it's just just writing out + + + align:start position:0% +outputs so it's just just writing out +the definition + + align:start position:0% +the definition + + + align:start position:0% +the definition +this this does not look symmetric + + align:start position:0% +this this does not look symmetric + + + align:start position:0% +this this does not look symmetric +because here the DX Prime is in in the + + align:start position:0% +because here the DX Prime is in in the + + + align:start position:0% +because here the DX Prime is in in the +argument and DX is what f is acting on + + align:start position:0% +argument and DX is what f is acting on + + + align:start position:0% +argument and DX is what f is acting on +but when you write out the derivative + + align:start position:0% +but when you write out the derivative + + + align:start position:0% +but when you write out the derivative +the definition the derivative then you + + align:start position:0% +the definition the derivative then you + + + align:start position:0% +the definition the derivative then you +see that both DX and DX Prime appear in + + align:start position:0% +see that both DX and DX Prime appear in + + + align:start position:0% +see that both DX and DX Prime appear in +the same way + + align:start position:0% +the same way + + + align:start position:0% +the same way +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so let's + + align:start position:0% +so let's + + + align:start position:0% +so let's +do uh you know uh so the 181 example is + + align:start position:0% +do uh you know uh so the 181 example is + + + align:start position:0% +do uh you know uh so the 181 example is +is very easy the the first derivative is + + align:start position:0% +is very easy the the first derivative is + + + align:start position:0% +is very easy the the first derivative is +a number the second derivative is also a + + align:start position:0% +a number the second derivative is also a + + + align:start position:0% +a number the second derivative is also a +number that that's kind of boring so + + align:start position:0% +number that that's kind of boring so + + + align:start position:0% +number that that's kind of boring so +that so it's it's The Familiar this is + + align:start position:0% +that so it's it's The Familiar this is + + + align:start position:0% +that so it's it's The Familiar this is +this is a strict generalization of what + + align:start position:0% +this is a strict generalization of what + + + align:start position:0% +this is a strict generalization of what +you learned before it's nothing new um + + align:start position:0% +you learned before it's nothing new um + + + align:start position:0% +you learned before it's nothing new um +but let's do an + + align:start position:0% +but let's do an + + + align:start position:0% +but let's do an +1802 you know multivariable + + align:start position:0% + + + + align:start position:0% + +calculus right so suppose we have a + + align:start position:0% + + + + align:start position:0% + +scalar function f + + align:start position:0% + + + + align:start position:0% + +ofx right so the output is a + + align:start position:0% +ofx right so the output is a + + + align:start position:0% +ofx right so the output is a +scalar + + align:start position:0% +scalar + + + align:start position:0% +scalar +but the input uh is going to be uh this + + align:start position:0% +but the input uh is going to be uh this + + + align:start position:0% +but the input uh is going to be uh this +this is going to be in RN so this is an + + align:start position:0% +this is going to be in RN so this is an + + + align:start position:0% +this is going to be in RN so this is an +N component + + align:start position:0% + + + + align:start position:0% + +Vector you could think of it as a column + + align:start position:0% +Vector you could think of it as a column + + + align:start position:0% +Vector you could think of it as a column +Vector if you if you if you + + align:start position:0% +Vector if you if you if you + + + align:start position:0% +Vector if you if you if you +want + + align:start position:0% + + + + align:start position:0% + +right so then what do we know so we know + + align:start position:0% +right so then what do we know so we know + + + align:start position:0% +right so then what do we know so we know +that FR + + align:start position:0% +that FR + + + align:start position:0% +that FR +Prim of x X is a row Vector it's the + + align:start position:0% +Prim of x X is a row Vector it's the + + + align:start position:0% +Prim of x X is a row Vector it's the +transpose of the + + align:start position:0% + + + + align:start position:0% + +gradient right so that that way um fime + + align:start position:0% +gradient right so that that way um fime + + + align:start position:0% +gradient right so that that way um fime +of x times DX is a + + align:start position:0% +of x times DX is a + + + align:start position:0% +of x times DX is a +scalar right that's the only way to get + + align:start position:0% +scalar right that's the only way to get + + + align:start position:0% +scalar right that's the only way to get +that's the only linear operator that + + align:start position:0% +that's the only linear operator that + + + align:start position:0% +that's the only linear operator that +takes a vector in and scalar out so then + + align:start position:0% +takes a vector in and scalar out so then + + + align:start position:0% +takes a vector in and scalar out so then +now let's think about what is um what is + + align:start position:0% +now let's think about what is um what is + + + align:start position:0% +now let's think about what is um what is +our our second + + align:start position:0% + + + + align:start position:0% + +derivative our fime X it has to take in + + align:start position:0% +derivative our fime X it has to take in + + + align:start position:0% +derivative our fime X it has to take in +two vectors DX Prime and DX so that now + + align:start position:0% +two vectors DX Prime and DX so that now + + + align:start position:0% +two vectors DX Prime and DX so that now +it doesn't really matter which order I + + align:start position:0% +it doesn't really matter which order I + + + align:start position:0% +it doesn't really matter which order I +put the the + + align:start position:0% +put the the + + + align:start position:0% +put the the +prime okay but it has to give a + + align:start position:0% + + + + align:start position:0% + +scalar right in the end right that that + + align:start position:0% +scalar right in the end right that that + + + align:start position:0% +scalar right in the end right that that +that's that the output is this has to + + align:start position:0% +that's that the output is this has to + + + align:start position:0% +that's that the output is this has to +match if you plug in both these things + + align:start position:0% +match if you plug in both these things + + + align:start position:0% +match if you plug in both these things +matches F right just again just go back + + align:start position:0% +matches F right just again just go back + + + align:start position:0% +matches F right just again just go back +to the definition uh uh um that you know + + align:start position:0% +to the definition uh uh um that you know + + + align:start position:0% +to the definition uh uh um that you know +you know uh uh um f Prime takes in a + + align:start position:0% +you know uh uh um f Prime takes in a + + + align:start position:0% +you know uh uh um f Prime takes in a +vector and gives you the the same output + + align:start position:0% +vector and gives you the the same output + + + align:start position:0% +vector and gives you the the same output +as F because it gives it gives you the + + align:start position:0% +as F because it gives it gives you the + + + align:start position:0% +as F because it gives it gives you the +the DF so F primed when you plug in your + + align:start position:0% +the DF so F primed when you plug in your + + + align:start position:0% +the DF so F primed when you plug in your +both vectors your DX DX Prime and DX and + + align:start position:0% +both vectors your DX DX Prime and DX and + + + align:start position:0% +both vectors your DX DX Prime and DX and +DX it has to give the same output as + + align:start position:0% +DX it has to give the same output as + + + align:start position:0% +DX it has to give the same output as +frime of DX right so it has to give this + + align:start position:0% +frime of DX right so it has to give this + + + align:start position:0% +frime of DX right so it has to give this +something the same shape as F so this + + align:start position:0% +something the same shape as F so this + + + align:start position:0% +something the same shape as F so this +this takes + + align:start position:0% +this takes + + + align:start position:0% +this takes +in two vectors and gives you a scalar + + align:start position:0% +in two vectors and gives you a scalar + + + align:start position:0% +in two vectors and gives you a scalar +right and and there's only there turns + + align:start position:0% +right and and there's only there turns + + + align:start position:0% +right and and there's only there turns +out there's only one kind of linear of + + align:start position:0% +out there's only one kind of linear of + + + align:start position:0% +out there's only one kind of linear of +way to write down an operation that + + align:start position:0% +way to write down an operation that + + + align:start position:0% +way to write down an operation that +takes in two column vectors and outputs + + align:start position:0% +takes in two column vectors and outputs + + + align:start position:0% +takes in two column vectors and outputs +a scalar and is linear in both of the + + align:start position:0% +a scalar and is linear in both of the + + + align:start position:0% +a scalar and is linear in both of the +vectors and that + + align:start position:0% +vectors and that + + + align:start position:0% +vectors and that +is to put a matrix + + align:start position:0% +is to put a matrix + + + align:start position:0% +is to put a matrix +here um and put a a DX here and a DX + + align:start position:0% +here um and put a a DX here and a DX + + + align:start position:0% +here um and put a a DX here and a DX +primed transpose over there + + align:start position:0% +primed transpose over there + + + align:start position:0% +primed transpose over there +and it has to be + + align:start position:0% + + + + align:start position:0% + +symmetric we know it has to be the same + + align:start position:0% +symmetric we know it has to be the same + + + align:start position:0% +symmetric we know it has to be the same +thing if you + + align:start position:0% +thing if you + + + align:start position:0% +thing if you +swap + + align:start position:0% +swap + + + align:start position:0% +swap +the the DX and DX + + align:start position:0% +the the DX and DX + + + align:start position:0% +the the DX and DX +Prime + + align:start position:0% +Prime + + + align:start position:0% +Prime +so um but that that that means actually + + align:start position:0% +so um but that that that means actually + + + align:start position:0% +so um but that that that means actually +it has to be a symmetric Matrix because + + align:start position:0% +it has to be a symmetric Matrix because + + + align:start position:0% +it has to be a symmetric Matrix because +this is this is also a + + align:start position:0% +this is this is also a + + + align:start position:0% +this is this is also a +number so it equals the transpose of + + align:start position:0% + + + + align:start position:0% + +itself + + align:start position:0% +itself + + + align:start position:0% +itself +right this is true for any number you + + align:start position:0% +right this is true for any number you + + + align:start position:0% +right this is true for any number you +can always equal to the transpose itself + + align:start position:0% +can always equal to the transpose itself + + + align:start position:0% +can always equal to the transpose itself +so that equals DX transpose H transpose + + align:start position:0% +so that equals DX transpose H transpose + + + align:start position:0% +so that equals DX transpose H transpose +uh uh um DX Prime so these two have to + + align:start position:0% +uh uh um DX Prime so these two have to + + + align:start position:0% +uh uh um DX Prime so these two have to +be + + align:start position:0% +be + + + align:start position:0% +be +equal right so we have a + + align:start position:0% + + + + align:start position:0% + +symmetric n byn + + align:start position:0% + + + + align:start position:0% + +Matrix h which is called The hessan + + align:start position:0% + + + + align:start position:0% + +Matrix how many of you have heard of + + align:start position:0% +Matrix how many of you have heard of + + + align:start position:0% +Matrix how many of you have heard of +Hessian matrices before yeah it's a fair + + align:start position:0% +Hessian matrices before yeah it's a fair + + + align:start position:0% +Hessian matrices before yeah it's a fair +number of you right so yeah so that's + + align:start position:0% +number of you right so yeah so that's + + + align:start position:0% +number of you right so yeah so that's +that's what a bilinear form looks like + + align:start position:0% +that's what a bilinear form looks like + + + align:start position:0% +that's what a bilinear form looks like +acting on column vectors it's it's a + + align:start position:0% +acting on column vectors it's it's a + + + align:start position:0% +acting on column vectors it's it's a +matrix right + + align:start position:0% +matrix right + + + align:start position:0% +matrix right +and but it's it's it's it's it's nice to + + align:start position:0% +and but it's it's it's it's it's nice to + + + align:start position:0% +and but it's it's it's it's it's nice to +write it in in 1802 terms sort of more + + align:start position:0% +write it in in 1802 terms sort of more + + + align:start position:0% +write it in in 1802 terms sort of more +explicitly like component wise right + + align:start position:0% +explicitly like component wise right + + + align:start position:0% +explicitly like component wise right +just like the gradient and 18 know in + + align:start position:0% +just like the gradient and 18 know in + + + align:start position:0% +just like the gradient and 18 know in +when you first learn it it's partial F + + align:start position:0% +when you first learn it it's partial F + + + align:start position:0% +when you first learn it it's partial F +partial X1 partial F partial X2 and so + + align:start position:0% +partial X1 partial F partial X2 and so + + + align:start position:0% +partial X1 partial F partial X2 and so +forth like H is is going to be the same + + align:start position:0% +forth like H is is going to be the same + + + align:start position:0% +forth like H is is going to be the same +thing so same kind of thing so so now if + + align:start position:0% +thing so same kind of thing so so now if + + + align:start position:0% +thing so same kind of thing so so now if +we do it + + align:start position:0% + + + + align:start position:0% + +explicitly let's just sort of write out + + align:start position:0% +explicitly let's just sort of write out + + + align:start position:0% +explicitly let's just sort of write out +slowly right so we know that the + + align:start position:0% +slowly right so we know that the + + + align:start position:0% +slowly right so we know that the +gradient of f is the vector that has + + align:start position:0% +gradient of f is the vector that has + + + align:start position:0% +gradient of f is the vector that has +partial F parti + + align:start position:0% +partial F parti + + + align:start position:0% +partial F parti +X1 to partial F partial + + align:start position:0% +X1 to partial F partial + + + align:start position:0% +X1 to partial F partial +xn + + align:start position:0% +xn + + + align:start position:0% +xn +right so that means what is what is + + align:start position:0% +right so that means what is what is + + + align:start position:0% +right so that means what is what is +um what we want to take is the change D + + align:start position:0% +um what we want to take is the change D + + + align:start position:0% +um what we want to take is the change D +of of + + align:start position:0% +of of + + + align:start position:0% +of of +uh of uh gradient + + align:start position:0% +uh of uh gradient + + + align:start position:0% +uh of uh gradient +F right uh say transposed I guess uh um + + align:start position:0% +F right uh say transposed I guess uh um + + + align:start position:0% +F right uh say transposed I guess uh um +yeah um you so what's yeah what's What's + + align:start position:0% +yeah um you so what's yeah what's What's + + + align:start position:0% +yeah um you so what's yeah what's What's +d of uh of + + align:start position:0% + + + + align:start position:0% + +uh of this for example so well it's the + + align:start position:0% +uh of this for example so well it's the + + + align:start position:0% +uh of this for example so well it's the +same thing + + align:start position:0% +same thing + + + align:start position:0% +same thing +as D of partial F partial + + align:start position:0% +as D of partial F partial + + + align:start position:0% +as D of partial F partial +X1 to d d of partial F partial + + align:start position:0% + + + + align:start position:0% + +xn + + align:start position:0% +xn + + + align:start position:0% +xn +but partial F partial X1 is a scalar + + align:start position:0% +but partial F partial X1 is a scalar + + + align:start position:0% +but partial F partial X1 is a scalar +function right that take for of of X of + + align:start position:0% +function right that take for of of X of + + + align:start position:0% +function right that take for of of X of +all the comp depends on all the + + align:start position:0% +all the comp depends on all the + + + align:start position:0% +all the comp depends on all the +components X and you spit that a number + + align:start position:0% +components X and you spit that a number + + + align:start position:0% +components X and you spit that a number +which is partial F partial X1 so we know + + align:start position:0% +which is partial F partial X1 so we know + + + align:start position:0% +which is partial F partial X1 so we know +what the D of that looks like the D of + + align:start position:0% +what the D of that looks like the D of + + + align:start position:0% +what the D of that looks like the D of +that + + align:start position:0% +that + + + align:start position:0% +that +is a + + align:start position:0% +is a + + + align:start position:0% +is a +gradient right of partial F partial X1 + + align:start position:0% +gradient right of partial F partial X1 + + + align:start position:0% +gradient right of partial F partial X1 +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +DX say all the way to gradient + + align:start position:0% +DX say all the way to gradient + + + align:start position:0% +DX say all the way to gradient +of partial F partial xn transpose + + align:start position:0% + + + + align:start position:0% + +DX but we can write that out + + align:start position:0% +DX but we can write that out + + + align:start position:0% +DX but we can write that out +as we can pull out the DX column vector + + align:start position:0% +as we can pull out the DX column vector + + + align:start position:0% +as we can pull out the DX column vector +and that's gradient of partial F partial + + align:start position:0% +and that's gradient of partial F partial + + + align:start position:0% +and that's gradient of partial F partial +X1 + + align:start position:0% +X1 + + + align:start position:0% +X1 +transpose all the way to par gradient of + + align:start position:0% +transpose all the way to par gradient of + + + align:start position:0% +transpose all the way to par gradient of +partial F partial xn + + align:start position:0% +partial F partial xn + + + align:start position:0% +partial F partial xn +transpose but that Matrix + + align:start position:0% +transpose but that Matrix + + + align:start position:0% +transpose but that Matrix +that what is the gradient that's that's + + align:start position:0% +that what is the gradient that's that's + + + align:start position:0% +that what is the gradient that's that's +the that's partial F that's partial + + align:start position:0% +the that's partial F that's partial + + + align:start position:0% +the that's partial F that's partial +squared of f partial X1 partial X1 + + align:start position:0% +squared of f partial X1 partial X1 + + + align:start position:0% +squared of f partial X1 partial X1 +to partial F partial X1 partial xn + + align:start position:0% +to partial F partial X1 partial xn + + + align:start position:0% +to partial F partial X1 partial xn +that's what the gradient transpose looks + + align:start position:0% +that's what the gradient transpose looks + + + align:start position:0% +that's what the gradient transpose looks +like I take partial partial F X1 and + + align:start position:0% +like I take partial partial F X1 and + + + align:start position:0% +like I take partial partial F X1 and +take this derivative respect to X1 to xn + + align:start position:0% +take this derivative respect to X1 to xn + + + align:start position:0% +take this derivative respect to X1 to xn +so that's a mixed second + + align:start position:0% +so that's a mixed second + + + align:start position:0% +so that's a mixed second +derivative and then the last row is the + + align:start position:0% +derivative and then the last row is the + + + align:start position:0% +derivative and then the last row is the +same thing partial squared partial F par + + align:start position:0% +same thing partial squared partial F par + + + align:start position:0% +same thing partial squared partial F par +I xn and I take its derivative respect + + align:start position:0% +I xn and I take its derivative respect + + + align:start position:0% +I xn and I take its derivative respect +to X1 all the way to its derivative with + + align:start position:0% +to X1 all the way to its derivative with + + + align:start position:0% +to X1 all the way to its derivative with +respect + + align:start position:0% +respect + + + align:start position:0% +respect +to xn derivatives xn + + align:start position:0% + + + + align:start position:0% + +DX right and this is uh this is this is + + align:start position:0% +DX right and this is uh this is this is + + + align:start position:0% +DX right and this is uh this is this is +a matrix of second derivatives this is + + align:start position:0% +a matrix of second derivatives this is + + + align:start position:0% +a matrix of second derivatives this is +this is exactly going to be um I guess + + align:start position:0% +this is exactly going to be um I guess + + + align:start position:0% +this is exactly going to be um I guess +this was + + align:start position:0% +this was + + + align:start position:0% +this was +um uh + + align:start position:0% +um uh + + + align:start position:0% +um uh +this this is this is I guess H uh or + + align:start position:0% +this this is this is I guess H uh or + + + align:start position:0% +this this is this is I guess H uh or +it's equal to I guess it's h transpose + + align:start position:0% +it's equal to I guess it's h transpose + + + align:start position:0% +it's equal to I guess it's h transpose +because gr gr F was the transpose of the + + align:start position:0% +because gr gr F was the transpose of the + + + align:start position:0% +because gr gr F was the transpose of the +derivative right so this gives you the + + align:start position:0% +derivative right so this gives you the + + + align:start position:0% +derivative right so this gives you the +change this is this is the D of frime + + align:start position:0% +change this is this is the D of frime + + + align:start position:0% +change this is this is the D of frime +transpose right so it's h transpose but + + align:start position:0% +transpose right so it's h transpose but + + + align:start position:0% +transpose right so it's h transpose but +we know that that equals H so it doesn't + + align:start position:0% +we know that that equals H so it doesn't + + + align:start position:0% +we know that that equals H so it doesn't +really matter and so now so then we get + + align:start position:0% +really matter and so now so then we get + + + align:start position:0% +really matter and so now so then we get +that the H the IJ + + align:start position:0% +that the H the IJ + + + align:start position:0% +that the H the IJ +element is just part + + align:start position:0% +element is just part + + + align:start position:0% +element is just part +F partial x i partial + + align:start position:0% +F partial x i partial + + + align:start position:0% +F partial x i partial +XJ but that equals hji because we know + + align:start position:0% +XJ but that equals hji because we know + + + align:start position:0% +XJ but that equals hji because we know +in general that the pesan is a symmetric + + align:start position:0% +in general that the pesan is a symmetric + + + align:start position:0% +in general that the pesan is a symmetric +Matrix is is a symmetric bilinear form + + align:start position:0% +Matrix is is a symmetric bilinear form + + + align:start position:0% +Matrix is is a symmetric bilinear form +which means it's a symmetric Matrix so + + align:start position:0% +which means it's a symmetric Matrix so + + + align:start position:0% +which means it's a symmetric Matrix so +that gives you this relationship you + + align:start position:0% +that gives you this relationship you + + + align:start position:0% +that gives you this relationship you +learned in multivariable calculus that I + + align:start position:0% +learned in multivariable calculus that I + + + align:start position:0% +learned in multivariable calculus that I +when I take partial derivatives I can + + align:start position:0% +when I take partial derivatives I can + + + align:start position:0% +when I take partial derivatives I can +swap the + + align:start position:0% +swap the + + + align:start position:0% +swap the +order it just comes from the definition + + align:start position:0% +order it just comes from the definition + + + align:start position:0% +order it just comes from the definition +the derivative but the point is that + + align:start position:0% +the derivative but the point is that + + + align:start position:0% +the derivative but the point is that +that extends to more when you extend + + align:start position:0% +that extends to more when you extend + + + align:start position:0% +that extends to more when you extend +that to more General objects it turns + + align:start position:0% +that to more General objects it turns + + + align:start position:0% +that to more General objects it turns +turns into this symmetric par your form + + align:start position:0% +turns into this symmetric par your form + + + align:start position:0% +turns into this symmetric par your form +business any questions + + align:start position:0% +business any questions + + + align:start position:0% +business any questions +yeah this should be n one like they + + align:start position:0% +yeah this should be n one like they + + + align:start position:0% +yeah this should be n one like they +should be reversed right just in the + + align:start position:0% +should be reversed right just in the + + + align:start position:0% +should be reversed right just in the +Matrix + + align:start position:0% +Matrix + + + align:start position:0% +Matrix +itself which the partial div these + + align:start position:0% +itself which the partial div these + + + align:start position:0% +itself which the partial div these +should be reversed yeah te I guess it + + align:start position:0% +should be reversed yeah te I guess it + + + align:start position:0% +should be reversed yeah te I guess it +depends on yes it depends on what you + + align:start position:0% +depends on yes it depends on what you + + + align:start position:0% +depends on yes it depends on what you +mean by part because because we're so + + align:start position:0% +mean by part because because we're so + + + align:start position:0% +mean by part because because we're so +used to the fact that this this you can + + align:start position:0% +used to the fact that this this you can + + + align:start position:0% +used to the fact that this this you can +take the derivative in either order so + + align:start position:0% +take the derivative in either order so + + + align:start position:0% +take the derivative in either order so +actually I don't know like does it mean + + align:start position:0% +actually I don't know like does it mean + + + align:start position:0% +actually I don't know like does it mean +you take the this derivative then this + + align:start position:0% +you take the this derivative then this + + + align:start position:0% +you take the this derivative then this +derivative or the other way around + + align:start position:0% +derivative or the other way around + + + align:start position:0% +derivative or the other way around +like if I put parentheses here I think + + align:start position:0% +like if I put parentheses here I think + + + align:start position:0% +like if I put parentheses here I think +it's + + align:start position:0% +it's + + + align:start position:0% +it's +right okay yeah because + + align:start position:0% +right okay yeah because + + + align:start position:0% +right okay yeah because +but the notation is kind of ambiguous + + align:start position:0% +but the notation is kind of ambiguous + + + align:start position:0% +but the notation is kind of ambiguous +because it doesn't need to be explicit + + align:start position:0% +because it doesn't need to be explicit + + + align:start position:0% +because it doesn't need to be explicit +because you can you can swap the order + + align:start position:0% +because you can you can swap the order + + + align:start position:0% +because you can you can swap the order +but yeah so I think I think yeah if I + + align:start position:0% +but yeah so I think I think yeah if I + + + align:start position:0% +but yeah so I think I think yeah if I +put derivative parentheses here that's + + align:start position:0% +put derivative parentheses here that's + + + align:start position:0% +put derivative parentheses here that's +sort of the the explicit thing I take + + align:start position:0% +sort of the the explicit thing I take + + + align:start position:0% +sort of the the explicit thing I take +partial F partial X1 I take it dtive + + align:start position:0% +partial F partial X1 I take it dtive + + + align:start position:0% +partial F partial X1 I take it dtive +respect to X1 and all the way to xn but + + align:start position:0% +respect to X1 and all the way to xn but + + + align:start position:0% +respect to X1 and all the way to xn but +if you put parentheses there then it's + + align:start position:0% +if you put parentheses there then it's + + + align:start position:0% +if you put parentheses there then it's +the opposite right but at the end of the + + align:start position:0% +the opposite right but at the end of the + + + align:start position:0% +the opposite right but at the end of the +day it's not going to matter because + + align:start position:0% +day it's not going to matter because + + + align:start position:0% +day it's not going to matter because +because this is + + align:start position:0% +because this is + + + align:start position:0% +because this is +symmetric yeah okay so so that's what + + align:start position:0% +symmetric yeah okay so so that's what + + + align:start position:0% +symmetric yeah okay so so that's what +you know you know how many learn the H + + align:start position:0% +you know you know how many learn the H + + + align:start position:0% +you know you know how many learn the H +Matrix this way it's basically it's the + + align:start position:0% +Matrix this way it's basically it's the + + + align:start position:0% +Matrix this way it's basically it's the +Matrix of all the mixed second + + align:start position:0% +Matrix of all the mixed second + + + align:start position:0% +Matrix of all the mixed second +derivative you have so that's that's + + align:start position:0% +derivative you have so that's that's + + + align:start position:0% +derivative you have so that's that's +usually how it's presented right so and + + align:start position:0% +usually how it's presented right so and + + + align:start position:0% +usually how it's presented right so and +that's yes that it's the Jacobian of the + + align:start position:0% +that's yes that it's the Jacobian of the + + + align:start position:0% +that's yes that it's the Jacobian of the +gradient in a way yeah it's exactly the + + align:start position:0% +gradient in a way yeah it's exactly the + + + align:start position:0% +gradient in a way yeah it's exactly the +Jacobian of the gradient yes good good + + align:start position:0% +Jacobian of the gradient yes good good + + + align:start position:0% +Jacobian of the gradient yes good good +good good let me me write that down so + + align:start position:0% +good good let me me write that down so + + + align:start position:0% +good good let me me write that down so +this is this is the + + align:start position:0% +this is this is the + + + align:start position:0% +this is this is the +um + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +exactly so um yeah so but but now we + + align:start position:0% +exactly so um yeah so but but now we + + + align:start position:0% +exactly so um yeah so but but now we +have it in a much more general setting + + align:start position:0% +have it in a much more general setting + + + align:start position:0% +have it in a much more general setting +right so it's it's I think it's it's + + align:start position:0% +right so it's it's I think it's it's + + + align:start position:0% +right so it's it's I think it's it's +it's nice to do let's do a let's do a + + align:start position:0% +it's nice to do let's do a let's do a + + + align:start position:0% +it's nice to do let's do a let's do a +more General + + align:start position:0% +more General + + + align:start position:0% +more General +example an example that you that it's + + align:start position:0% +example an example that you that it's + + + align:start position:0% +example an example that you that it's +not so easy to + + align:start position:0% +not so easy to + + + align:start position:0% +not so easy to +do with 1801 + + align:start position:0% +do with 1801 + + + align:start position:0% +do with 1801 +let's do 1802 even let's take our + + align:start position:0% +let's do 1802 even let's take our + + + align:start position:0% +let's do 1802 even let's take our +favorite function our new favorite + + align:start position:0% +favorite function our new favorite + + + align:start position:0% +favorite function our new favorite +function that takes in a matrix and + + align:start position:0% +function that takes in a matrix and + + + align:start position:0% +function that takes in a matrix and +gives you a + + align:start position:0% +gives you a + + + align:start position:0% +gives you a +scalar right so uh from previous from + + align:start position:0% +scalar right so uh from previous from + + + align:start position:0% +scalar right so uh from previous from +the previous lecture we we learn what + + align:start position:0% +the previous lecture we we learn what + + + align:start position:0% +the previous lecture we we learn what +the derivative of this + + align:start position:0% +the derivative of this + + + align:start position:0% +the derivative of this +is so if you take FR primed of + + align:start position:0% +is so if you take FR primed of + + + align:start position:0% +is so if you take FR primed of +a that's that's the linear operator act + + align:start position:0% +a that's that's the linear operator act + + + align:start position:0% +a that's that's the linear operator act +that acting on da what it gives you is + + align:start position:0% +that acting on da what it gives you is + + + align:start position:0% +that acting on da what it gives you is +deter terminant + + align:start position:0% +deter terminant + + + align:start position:0% +deter terminant +a times the trace of a inverse + + align:start position:0% +a times the trace of a inverse + + + align:start position:0% +a times the trace of a inverse +da right so or equivalently we showed + + align:start position:0% +da right so or equivalently we showed + + + align:start position:0% +da right so or equivalently we showed +that the the gradient of f was the + + align:start position:0% +that the the gradient of f was the + + + align:start position:0% +that the the gradient of f was the +determinant of a times the transpose of + + align:start position:0% +determinant of a times the transpose of + + + align:start position:0% +determinant of a times the transpose of +this a inverse transpose which is called + + align:start position:0% +this a inverse transpose which is called + + + align:start position:0% +this a inverse transpose which is called +the The adjugate + + align:start position:0% + + + + align:start position:0% + +Matrix yeah the adjugate of the + + align:start position:0% +Matrix yeah the adjugate of the + + + align:start position:0% +Matrix yeah the adjugate of the +transpose of the ugate sorry the + + align:start position:0% +transpose of the ugate sorry the + + + align:start position:0% +transpose of the ugate sorry the +adjugate + + align:start position:0% + + + + align:start position:0% + +transposed I always forget which is + + align:start position:0% +transposed I always forget which is + + + align:start position:0% +transposed I always forget which is +which um it's the co-actor Matrix of a + + align:start position:0% +which um it's the co-actor Matrix of a + + + align:start position:0% +which um it's the co-actor Matrix of a +um so yes so we saw this and and there's + + align:start position:0% +um so yes so we saw this and and there's + + + align:start position:0% +um so yes so we saw this and and there's +various ways you can you can you can + + align:start position:0% +various ways you can you can you can + + + align:start position:0% +various ways you can you can you can +show this so Professor adman looked at a + + align:start position:0% +show this so Professor adman looked at a + + + align:start position:0% +show this so Professor adman looked at a +couple different ways so now let's go + + align:start position:0% +couple different ways so now let's go + + + align:start position:0% +couple different ways so now let's go +one step further and now let's let's + + align:start position:0% +one step further and now let's let's + + + align:start position:0% +one step further and now let's let's +take the second derivative and whenever + + align:start position:0% +take the second derivative and whenever + + + align:start position:0% +take the second derivative and whenever +we faces something new and confusing + + align:start position:0% +we faces something new and confusing + + + align:start position:0% +we faces something new and confusing +it's it's always good to fall back on + + align:start position:0% +it's it's always good to fall back on + + + align:start position:0% +it's it's always good to fall back on +the definition right so all we're doing + + align:start position:0% +the definition right so all we're doing + + + align:start position:0% +the definition right so all we're doing +is just uh I'm going to take um we're + + align:start position:0% +is just uh I'm going to take um we're + + + align:start position:0% +is just uh I'm going to take um we're +going to take uh D of this right d + + align:start position:0% +going to take uh D of this right d + + + align:start position:0% +going to take uh D of this right d +of of of uh of uh of this whole + + align:start position:0% +of of of uh of uh of this whole + + + align:start position:0% +of of of uh of uh of this whole +formula determinant a trace a a + + align:start position:0% +formula determinant a trace a a + + + align:start position:0% +formula determinant a trace a a +inverse + + align:start position:0% +inverse + + + align:start position:0% +inverse +da + + align:start position:0% +da + + + align:start position:0% +da +I'm going to put a prime here here just + + align:start position:0% +I'm going to put a prime here here just + + + align:start position:0% +I'm going to put a prime here here just +just to make it clear that what I'm + + align:start position:0% +just to make it clear that what I'm + + + align:start position:0% +just to make it clear that what I'm +changing is a not da I'm going to use a + + align:start position:0% +changing is a not da I'm going to use a + + + align:start position:0% +changing is a not da I'm going to use a +DA Prime so da D + + align:start position:0% +DA Prime so da D + + + align:start position:0% +DA Prime so da D +primed so this what this is going to be + + align:start position:0% +primed so this what this is going to be + + + align:start position:0% +primed so this what this is going to be +is this is going to be + + align:start position:0% +is this is going to be + + + align:start position:0% +is this is going to be +our F primed of a plus da + + align:start position:0% +our F primed of a plus da + + + align:start position:0% +our F primed of a plus da +primed acting on + + align:start position:0% +primed acting on + + + align:start position:0% +primed acting on +da let me give myself a little more + + align:start position:0% +da let me give myself a little more + + + align:start position:0% +da let me give myself a little more +space + + align:start position:0% + + + + align:start position:0% + +minus frime of + + align:start position:0% +minus frime of + + + align:start position:0% +minus frime of +a On Da right so the prime here is just + + align:start position:0% +a On Da right so the prime here is just + + + align:start position:0% +a On Da right so the prime here is just +it's not another derivative I'm + + align:start position:0% +it's not another derivative I'm + + + align:start position:0% +it's not another derivative I'm +overloading my primes a little bit but + + align:start position:0% +overloading my primes a little bit but + + + align:start position:0% +overloading my primes a little bit but +it's just it just means I'm using I'm + + align:start position:0% +it's just it just means I'm using I'm + + + align:start position:0% +it's just it just means I'm using I'm +Chang I'm changing a by da + + align:start position:0% +Chang I'm changing a by da + + + align:start position:0% +Chang I'm changing a by da +Prime okay and and da is going to be + + align:start position:0% +Prime okay and and da is going to be + + + align:start position:0% +Prime okay and and da is going to be +fixed yes in the previous example as + + align:start position:0% +fixed yes in the previous example as + + + align:start position:0% +fixed yes in the previous example as +well that was technically DX right just + + align:start position:0% +well that was technically DX right just + + + align:start position:0% +well that was technically DX right just +clarify + + align:start position:0% +clarify + + + align:start position:0% +clarify +yeah um yeah well I didn't have any DXs + + align:start position:0% +yeah um yeah well I didn't have any DXs + + + align:start position:0% +yeah um yeah well I didn't have any DXs +here so I didn't need a a d Prime right + + align:start position:0% +here so I didn't need a a d Prime right + + + align:start position:0% +here so I didn't need a a d Prime right +so yeah yeah I but I could have used a d + + align:start position:0% +so yeah yeah I but I could have used a d + + + align:start position:0% +so yeah yeah I but I could have used a d +Prime there if I wanted but it's really + + align:start position:0% +Prime there if I wanted but it's really + + + align:start position:0% +Prime there if I wanted but it's really +the same kind of thing it's just I I + + align:start position:0% +the same kind of thing it's just I I + + + align:start position:0% +the same kind of thing it's just I I +already have a DA here and I want to be + + align:start position:0% +already have a DA here and I want to be + + + align:start position:0% +already have a DA here and I want to be +careful that I'm not changing this this + + align:start position:0% +careful that I'm not changing this this + + + align:start position:0% +careful that I'm not changing this this +is this is now going to be this is + + align:start position:0% +is this is now going to be this is + + + align:start position:0% +is this is now going to be this is +actually let me put this in blue here + + align:start position:0% +actually let me put this in blue here + + + align:start position:0% +actually let me put this in blue here +this + + align:start position:0% +this + + + align:start position:0% +this +is um so this + + align:start position:0% +is um so this + + + align:start position:0% +is um so this +is da da + + align:start position:0% +is da da + + + align:start position:0% +is da da +da this is going to be + + align:start position:0% + + + + align:start position:0% + +fixed okay so da is Da is not changing + + align:start position:0% +fixed okay so da is Da is not changing + + + align:start position:0% +fixed okay so da is Da is not changing +we can think of as a a + + align:start position:0% +we can think of as a a + + + align:start position:0% +we can think of as a a +constant so when I when I change things + + align:start position:0% +constant so when I when I change things + + + align:start position:0% +constant so when I when I change things +I'm changing a by da Prime okay and so + + align:start position:0% +I'm changing a by da Prime okay and so + + + align:start position:0% +I'm changing a by da Prime okay and so +now I can just use the by the product + + align:start position:0% +now I can just use the by the product + + + align:start position:0% +now I can just use the by the product +use the uh um our derivative + + align:start position:0% +use the uh um our derivative + + + align:start position:0% +use the uh um our derivative +rules our + + align:start position:0% +rules our + + + align:start position:0% +rules our +product uh and our chain + + align:start position:0% + + + + align:start position:0% + +rules dot dot dot right and what do I + + align:start position:0% +rules dot dot dot right and what do I + + + align:start position:0% +rules dot dot dot right and what do I +get right + + align:start position:0% +get right + + + align:start position:0% +get right +so so so now I'm just treating da as + + align:start position:0% +so so so now I'm just treating da as + + + align:start position:0% +so so so now I'm just treating da as +just a constant Matrix I'm sticking in + + align:start position:0% +just a constant Matrix I'm sticking in + + + align:start position:0% +just a constant Matrix I'm sticking in +there and then I'm taking the derivative + + align:start position:0% +there and then I'm taking the derivative + + + align:start position:0% +there and then I'm taking the derivative +the same way as before well I have the + + align:start position:0% +the same way as before well I have the + + + align:start position:0% +the same way as before well I have the +derivative of this term times this plus + + align:start position:0% +derivative of this term times this plus + + + align:start position:0% +derivative of this term times this plus +this times the derivative of that term + + align:start position:0% +this times the derivative of that term + + + align:start position:0% +this times the derivative of that term +right and the Der of this term we just + + align:start position:0% +right and the Der of this term we just + + + align:start position:0% +right and the Der of this term we just +we just or the differential sorry of + + align:start position:0% +we just or the differential sorry of + + + align:start position:0% +we just or the differential sorry of +that term we just saw what it was right + + align:start position:0% +that term we just saw what it was right + + + align:start position:0% +that term we just saw what it was right +this is our this is our CH oops it's + + align:start position:0% +this is our this is our CH oops it's + + + align:start position:0% +this is our this is our CH oops it's +this ah it's this right so the first + + align:start position:0% +this ah it's this right so the first + + + align:start position:0% +this ah it's this right so the first +term + + align:start position:0% +term + + + align:start position:0% +term +is uh determinant of a + + align:start position:0% +is uh determinant of a + + + align:start position:0% +is uh determinant of a +times uh so so the D of the determinant + + align:start position:0% +times uh so so the D of the determinant + + + align:start position:0% +times uh so so the D of the determinant +is the determinant of a times the trace + + align:start position:0% +is the determinant of a times the trace + + + align:start position:0% +is the determinant of a times the trace +of a prime not a prime a + + align:start position:0% +of a prime not a prime a + + + align:start position:0% +of a prime not a prime a +inverse da + + align:start position:0% +inverse da + + + align:start position:0% +inverse da +primed right so this came + + align:start position:0% +primed right so this came + + + align:start position:0% +primed right so this came +from + + align:start position:0% + + + + align:start position:0% + +that term right times times the other + + align:start position:0% +that term right times times the other + + + align:start position:0% +that term right times times the other +term trace of a + + align:start position:0% +term trace of a + + + align:start position:0% +term trace of a +inverse + + align:start position:0% + + + + align:start position:0% + +da + + align:start position:0% +da + + + align:start position:0% +da +plus I have my still have my determinant + + align:start position:0% +plus I have my still have my determinant + + + align:start position:0% +plus I have my still have my determinant +of + + align:start position:0% + + + + align:start position:0% + +a times the derivative of the other + + align:start position:0% + + + + align:start position:0% + +term and Trace is a linear operator so I + + align:start position:0% +term and Trace is a linear operator so I + + + align:start position:0% +term and Trace is a linear operator so I +can just take the derivative + + align:start position:0% +can just take the derivative + + + align:start position:0% +can just take the derivative +inside and so now I or the differential + + align:start position:0% +inside and so now I or the differential + + + align:start position:0% +inside and so now I or the differential +inside and now I need da inverse and we + + align:start position:0% +inside and now I need da inverse and we + + + align:start position:0% +inside and now I need da inverse and we +know what da inverse that was a minus + + align:start position:0% +know what da inverse that was a minus + + + align:start position:0% +know what da inverse that was a minus +sign so let me change this to a minus + + align:start position:0% +sign so let me change this to a minus + + + align:start position:0% +sign so let me change this to a minus +sign okay of a + + align:start position:0% +sign okay of a + + + align:start position:0% +sign okay of a +inverse d a primed a + + align:start position:0% +inverse d a primed a + + + align:start position:0% +inverse d a primed a +inverse and then there's still a + + align:start position:0% +inverse and then there's still a + + + align:start position:0% +inverse and then there's still a +DA everyone see that so This this term + + align:start position:0% +DA everyone see that so This this term + + + align:start position:0% +DA everyone see that so This this term +here is exactly D + + align:start position:0% +here is exactly D + + + align:start position:0% +here is exactly D +primed of a + + align:start position:0% +primed of a + + + align:start position:0% +primed of a +inverse well with the minus + + align:start position:0% + + + + align:start position:0% + +sign + + align:start position:0% + + + + align:start position:0% + +and now the question is is this this + + align:start position:0% +and now the question is is this this + + + align:start position:0% +and now the question is is this this +this is it this is this is a bi it's not + + align:start position:0% +this is it this is this is a bi it's not + + + align:start position:0% +this is it this is this is a bi it's not +going to get much simpler than this this + + align:start position:0% +going to get much simpler than this this + + + align:start position:0% +going to get much simpler than this this +this is our bilinear form + + align:start position:0% + + + + align:start position:0% + +this is + + align:start position:0% + + + + align:start position:0% + +bilinear and you know in da primed and + + align:start position:0% +bilinear and you know in da primed and + + + align:start position:0% +bilinear and you know in da primed and +uh and uh + + align:start position:0% +uh and uh + + + align:start position:0% +uh and uh +da right so I stick in any da Prime any + + align:start position:0% +da right so I stick in any da Prime any + + + align:start position:0% +da right so I stick in any da Prime any +da clearly this is linear in each one of + + align:start position:0% +da clearly this is linear in each one of + + + align:start position:0% +da clearly this is linear in each one of +them individually right there's I never + + align:start position:0% +them individually right there's I never + + + align:start position:0% +them individually right there's I never +I never multip I can multiply da by da + + align:start position:0% +I never multip I can multiply da by da + + + align:start position:0% +I never multip I can multiply da by da +Prime it's + + align:start position:0% +Prime it's + + + align:start position:0% +Prime it's +quadratic but it's but but it's uh + + align:start position:0% +quadratic but it's but but it's uh + + + align:start position:0% +quadratic but it's but but it's uh +but I can't multiply um d da by itself + + align:start position:0% +but I can't multiply um d da by itself + + + align:start position:0% +but I can't multiply um d da by itself +okay and is it + + align:start position:0% +okay and is it + + + align:start position:0% +okay and is it +symmetric well let's look this term is + + align:start position:0% +symmetric well let's look this term is + + + align:start position:0% +symmetric well let's look this term is +the same as + + align:start position:0% +the same as + + + align:start position:0% +the same as +this right so if I swap and these are + + align:start position:0% +this right so if I swap and these are + + + align:start position:0% +this right so if I swap and these are +just Trace is just number so I can swap + + align:start position:0% +just Trace is just number so I can swap + + + align:start position:0% +just Trace is just number so I can swap +these two terms and that's that's that's + + align:start position:0% +these two terms and that's that's that's + + + align:start position:0% +these two terms and that's that's that's +fine this is and this is also a number + + align:start position:0% +fine this is and this is also a number + + + align:start position:0% +fine this is and this is also a number +right what about this if I swap D and D + + align:start position:0% +right what about this if I swap D and D + + + align:start position:0% +right what about this if I swap D and D +prime it looks it looks a little bit + + align:start position:0% +prime it looks it looks a little bit + + + align:start position:0% +prime it looks it looks a little bit +different but remember the trace has the + + align:start position:0% +different but remember the trace has the + + + align:start position:0% +different but remember the trace has the +cyclic property I can I can move the + + align:start position:0% +cyclic property I can I can move the + + + align:start position:0% +cyclic property I can I can move the +like the a inverse da over to the + + align:start position:0% +like the a inverse da over to the + + + align:start position:0% +like the a inverse da over to the +beginning and then it looks like trace + + align:start position:0% +beginning and then it looks like trace + + + align:start position:0% +beginning and then it looks like trace +of a inverse da a inverse da + + align:start position:0% +of a inverse da a inverse da + + + align:start position:0% +of a inverse da a inverse da +Prime right so this + + align:start position:0% +Prime right so this + + + align:start position:0% +Prime right so this +is this is + + align:start position:0% + + + + align:start position:0% + +symmetric uh + + align:start position:0% +symmetric uh + + + align:start position:0% +symmetric uh +using this cyclic property of the + + align:start position:0% + + + + align:start position:0% + +trace + + align:start position:0% + + + + align:start position:0% + +that's it this is this this doesn't + + align:start position:0% +that's it this is this this doesn't + + + align:start position:0% +that's it this is this this doesn't +simplify into we can't write it as a + + align:start position:0% +simplify into we can't write it as a + + + align:start position:0% +simplify into we can't write it as a +Hessian matrix unless I vectorize things + + align:start position:0% +Hessian matrix unless I vectorize things + + + align:start position:0% +Hessian matrix unless I vectorize things +okay so if I if I if I do VC of d da + + align:start position:0% +okay so if I if I if I do VC of d da + + + align:start position:0% +okay so if I if I if I do VC of d da +right this this could be some big Matrix + + align:start position:0% +right this this could be some big Matrix + + + align:start position:0% +right this this could be some big Matrix +and and squ by yeah it's n s by n s + + align:start position:0% +and and squ by yeah it's n s by n s + + + align:start position:0% +and and squ by yeah it's n s by n s +Matrix right that has a VEC of Da on one + + align:start position:0% +Matrix right that has a VEC of Da on one + + + align:start position:0% +Matrix right that has a VEC of Da on one +side and VEC of Da Prime on the other + + align:start position:0% +side and VEC of Da Prime on the other + + + align:start position:0% +side and VEC of Da Prime on the other +side but it's it's not very natural to + + align:start position:0% +side but it's it's not very natural to + + + align:start position:0% +side but it's it's not very natural to +do that and see in some ways it's easier + + align:start position:0% +do that and see in some ways it's easier + + + align:start position:0% +do that and see in some ways it's easier +to do this okay + + align:start position:0% + + + + align:start position:0% + +so so let's I want to talk a little bit + + align:start position:0% +so so let's I want to talk a little bit + + + align:start position:0% +so so let's I want to talk a little bit +about + + align:start position:0% + + + + align:start position:0% + +um now why second + + align:start position:0% + + + + align:start position:0% + +derivatives and of course they come up + + align:start position:0% +derivatives and of course they come up + + + align:start position:0% +derivatives and of course they come up +in lots of cases right but but let me + + align:start position:0% +in lots of cases right but but let me + + + align:start position:0% +in lots of cases right but but let me +just mention a few Salient things so + + align:start position:0% +just mention a few Salient things so + + + align:start position:0% +just mention a few Salient things so +first of all they give you the the the + + align:start position:0% +first of all they give you the the the + + + align:start position:0% +first of all they give you the the the +first Der of give you a linear + + align:start position:0% +first Der of give you a linear + + + align:start position:0% +first Der of give you a linear +approximation of a function + + align:start position:0% +approximation of a function + + + align:start position:0% +approximation of a function +linearization this the second + + align:start position:0% +linearization this the second + + + align:start position:0% +linearization this the second +derivatives give you quadratic + + align:start position:0% + + + + align:start position:0% + +approximations right so if you have + + align:start position:0% +approximations right so if you have + + + align:start position:0% +approximations right so if you have +f of x plus little a little change let's + + align:start position:0% +f of x plus little a little change let's + + + align:start position:0% +f of x plus little a little change let's +call it Delta X that's not it's not + + align:start position:0% +call it Delta X that's not it's not + + + align:start position:0% +call it Delta X that's not it's not +infinite decimal anymore so this is + + align:start position:0% +infinite decimal anymore so this is + + + align:start position:0% +infinite decimal anymore so this is +going to be an + + align:start position:0% +going to be an + + + align:start position:0% +going to be an +approximation + + align:start position:0% +approximation + + + align:start position:0% +approximation +this is approximately f + + align:start position:0% +this is approximately f + + + align:start position:0% +this is approximately f +ofx plus frime of X Delta X that's our + + align:start position:0% +ofx plus frime of X Delta X that's our + + + align:start position:0% +ofx plus frime of X Delta X that's our +linear approximation from the first + + align:start position:0% +linear approximation from the first + + + align:start position:0% +linear approximation from the first +derivative or finite difference + + align:start position:0% +derivative or finite difference + + + align:start position:0% +derivative or finite difference +approximation if you think of it and now + + align:start position:0% +approximation if you think of it and now + + + align:start position:0% +approximation if you think of it and now +there'll be a new + + align:start position:0% +there'll be a new + + + align:start position:0% +there'll be a new +term that'll look like f Prim of X with + + align:start position:0% +term that'll look like f Prim of X with + + + align:start position:0% +term that'll look like f Prim of X with +a Delta x a Delta + + align:start position:0% +a Delta x a Delta + + + align:start position:0% +a Delta x a Delta +X and I'm missing something what am I + + align:start position:0% + + + + align:start position:0% + +missing + + align:start position:0% +missing + + + align:start position:0% +missing +just think of 1801 Taylor + + align:start position:0% +just think of 1801 Taylor + + + align:start position:0% +just think of 1801 Taylor +series there's a half yeah right and + + align:start position:0% +series there's a half yeah right and + + + align:start position:0% +series there's a half yeah right and +then and then and then and then there's + + align:start position:0% +then and then and then and then there's + + + align:start position:0% +then and then and then and then there's +higher order terms little low of Delta + + align:start position:0% +higher order terms little low of Delta + + + align:start position:0% +higher order terms little low of Delta +X squar right we're dropping terms so + + align:start position:0% +X squar right we're dropping terms so + + + align:start position:0% +X squar right we're dropping terms so +we're dropping terms that are + + align:start position:0% + + + + align:start position:0% + +smaller than + + align:start position:0% +smaller than + + + align:start position:0% +smaller than +quadratic all right so if it's if it's + + align:start position:0% +quadratic all right so if it's if it's + + + align:start position:0% +quadratic all right so if it's if it's +three times differentiable we're + + align:start position:0% +three times differentiable we're + + + align:start position:0% +three times differentiable we're +dropping cubic terms but maybe the + + align:start position:0% +dropping cubic terms but maybe the + + + align:start position:0% +dropping cubic terms but maybe the +function doesn't have at their + + align:start position:0% +function doesn't have at their + + + align:start position:0% +function doesn't have at their +derivative but definitely what we're + + align:start position:0% +derivative but definitely what we're + + + align:start position:0% +derivative but definitely what we're +dropping are are terms that are higher + + align:start position:0% +dropping are are terms that are higher + + + align:start position:0% +dropping are are terms that are higher +than quadratic so the + + align:start position:0% +than quadratic so the + + + align:start position:0% +than quadratic so the +1/2 you can you can derive this pretty + + align:start position:0% +1/2 you can you can derive this pretty + + + align:start position:0% +1/2 you can you can derive this pretty +easily by just just if you if if you + + align:start position:0% +easily by just just if you if if you + + + align:start position:0% +easily by just just if you if if you +take two derivatives of this you'd + + align:start position:0% +take two derivatives of this you'd + + + align:start position:0% +take two derivatives of this you'd +better get back to F Prime F Prime right + + align:start position:0% +better get back to F Prime F Prime right + + + align:start position:0% +better get back to F Prime F Prime right +it's better had a better match the + + align:start position:0% +it's better had a better match the + + + align:start position:0% +it's better had a better match the +second derivative but because DX appears + + align:start position:0% +second derivative but because DX appears + + + align:start position:0% +second derivative but because DX appears +twice in this then uh if you take two + + align:start position:0% +twice in this then uh if you take two + + + align:start position:0% +twice in this then uh if you take two +der to Delta X sorry you should get you + + align:start position:0% +der to Delta X sorry you should get you + + + align:start position:0% +der to Delta X sorry you should get you +should get back to f F Prim and but + + align:start position:0% +should get back to f F Prim and but + + + align:start position:0% +should get back to f F Prim and but +because Delta X appears twice in this + + align:start position:0% +because Delta X appears twice in this + + + align:start position:0% +because Delta X appears twice in this +you need to have a half there um in + + align:start position:0% +you need to have a half there um in + + + align:start position:0% +you need to have a half there um in +order to get back to F Prime so if we + + align:start position:0% +order to get back to F Prime so if we + + + align:start position:0% +order to get back to F Prime so if we +take let me just write that in so if we + + align:start position:0% +take let me just write that in so if we + + + align:start position:0% +take let me just write that in so if we +take okay the second + + align:start position:0% + + + + align:start position:0% + +derivative with + + align:start position:0% +derivative with + + + align:start position:0% +derivative with +respect to Delta X you had better get + + align:start position:0% +respect to Delta X you had better get + + + align:start position:0% +respect to Delta X you had better get +back to fpre of X and that 1/ half + + align:start position:0% +back to fpre of X and that 1/ half + + + align:start position:0% +back to fpre of X and that 1/ half +factor is is is + + align:start position:0% + + + + align:start position:0% + +necessary because it appears twice so + + align:start position:0% +necessary because it appears twice so + + + align:start position:0% +necessary because it appears twice so +otherwise you you'd see it get twice + + align:start position:0% +otherwise you you'd see it get twice + + + align:start position:0% +otherwise you you'd see it get twice +just like if you you know for the same + + align:start position:0% +just like if you you know for the same + + + align:start position:0% +just like if you you know for the same +same reason you have it in the Taylor + + align:start position:0% +same reason you have it in the Taylor + + + align:start position:0% +same reason you have it in the Taylor +series right if these are just scalers + + align:start position:0% +series right if these are just scalers + + + align:start position:0% +series right if these are just scalers +right when I take this this is a Delta x + + align:start position:0% +right when I take this this is a Delta x + + + align:start position:0% +right when I take this this is a Delta x +squared when I take the second + + align:start position:0% +squared when I take the second + + + align:start position:0% +squared when I take the second +derivative I'm going to get a two and if + + align:start position:0% +derivative I'm going to get a two and if + + + align:start position:0% +derivative I'm going to get a two and if +I really wanted to match the second + + align:start position:0% +I really wanted to match the second + + + align:start position:0% +I really wanted to match the second +derivative if you know of my function at + + align:start position:0% +derivative if you know of my function at + + + align:start position:0% +derivative if you know of my function at +that point so okay so you know linear + + align:start position:0% +that point so okay so you know linear + + + align:start position:0% +that point so okay so you know linear +approximating things by the things is + + align:start position:0% +approximating things by the things is + + + align:start position:0% +approximating things by the things is +useful approxim things like quadratic + + align:start position:0% +useful approxim things like quadratic + + + align:start position:0% +useful approxim things like quadratic +functions is useful so for example um if + + align:start position:0% +functions is useful so for example um if + + + align:start position:0% +functions is useful so for example um if +you're doing + + align:start position:0% + + + + align:start position:0% + +optimization right we approximate uh + + align:start position:0% +optimization right we approximate uh + + + align:start position:0% +optimization right we approximate uh +f f uh by approximately a + + align:start position:0% +f f uh by approximately a + + + align:start position:0% +f f uh by approximately a +quadratic and then optimiz + + align:start position:0% + + + + align:start position:0% + +the + + align:start position:0% + + + + align:start position:0% + +quadratic to get a + + align:start position:0% +quadratic to get a + + + align:start position:0% +quadratic to get a +step a + + align:start position:0% +step a + + + align:start position:0% +step a +step this is sometimes called this has a + + align:start position:0% +step this is sometimes called this has a + + + align:start position:0% +step this is sometimes called this has a +variety of names it's sometimes called + + align:start position:0% +variety of names it's sometimes called + + + align:start position:0% +variety of names it's sometimes called +sequential quadratic + + align:start position:0% + + + + align:start position:0% + +programming or or + + align:start position:0% +programming or or + + + align:start position:0% +programming or or +sqp technically you you should also if + + align:start position:0% +sqp technically you you should also if + + + align:start position:0% +sqp technically you you should also if +you if you have constraints you + + align:start position:0% +you if you have constraints you + + + align:start position:0% +you if you have constraints you +take you you make linear approximations + + align:start position:0% +take you you make linear approximations + + + align:start position:0% +take you you make linear approximations +of the + + align:start position:0% +of the + + + align:start position:0% +of the +constraints or I guess uh aine + + align:start position:0% + + + + align:start position:0% + +approximations but it's colloquially + + align:start position:0% +approximations but it's colloquially + + + align:start position:0% +approximations but it's colloquially +it's called linear + + align:start position:0% +it's called linear + + + align:start position:0% +it's called linear +approximations a + + align:start position:0% +approximations a + + + align:start position:0% +approximations a +prod of + + align:start position:0% +prod of + + + align:start position:0% +prod of +constraints so if you have a arbit + + align:start position:0% +constraints so if you have a arbit + + + align:start position:0% +constraints so if you have a arbit +minimizing an arbitrary nonlinear + + align:start position:0% +minimizing an arbitrary nonlinear + + + align:start position:0% +minimizing an arbitrary nonlinear +function arbitrary con nonlinear + + align:start position:0% +function arbitrary con nonlinear + + + align:start position:0% +function arbitrary con nonlinear +constraints right um that's hard but if + + align:start position:0% +constraints right um that's hard but if + + + align:start position:0% +constraints right um that's hard but if +you approximate the function by a + + align:start position:0% +you approximate the function by a + + + align:start position:0% +you approximate the function by a +quadratic function using a second + + align:start position:0% +quadratic function using a second + + + align:start position:0% +quadratic function using a second +derivative approximate the constraints + + align:start position:0% +derivative approximate the constraints + + + align:start position:0% +derivative approximate the constraints +by linear that's called a QP or + + align:start position:0% +by linear that's called a QP or + + + align:start position:0% +by linear that's called a QP or +quadratic program and there are there + + align:start position:0% +quadratic program and there are there + + + align:start position:0% +quadratic program and there are there +are you know good methods to solve those + + align:start position:0% +are you know good methods to solve those + + + align:start position:0% +are you know good methods to solve those +kinds of things right + + align:start position:0% +kinds of things right + + + align:start position:0% +kinds of things right +um another equivalent + + align:start position:0% +um another equivalent + + + align:start position:0% +um another equivalent +equivalently optimizing a quadratic + + align:start position:0% +equivalently optimizing a quadratic + + + align:start position:0% +equivalently optimizing a quadratic +function is the same thing is uh you + + align:start position:0% +function is the same thing is uh you + + + align:start position:0% +function is the same thing is uh you +know so optimizing a function is equal + + align:start position:0% +know so optimizing a function is equal + + + align:start position:0% +know so optimizing a function is equal +to finding locally to finding you know a + + align:start position:0% +to finding locally to finding you know a + + + align:start position:0% +to finding locally to finding you know a +root of the gradient right so we're + + align:start position:0% +root of the gradient right so we're + + + align:start position:0% +root of the gradient right so we're +equivalently + + align:start position:0% +equivalently + + + align:start position:0% +equivalently +finding a root of the gradient of F and + + align:start position:0% +finding a root of the gradient of F and + + + align:start position:0% +finding a root of the gradient of F and +you're going to approximate it by a + + align:start position:0% +you're going to approximate it by a + + + align:start position:0% +you're going to approximate it by a +linear you know by an + + align:start position:0% +linear you know by an + + + align:start position:0% +linear you know by an +Aline by + + align:start position:0% +Aline by + + + align:start position:0% +Aline by +by right because if I but you know or + + align:start position:0% +by right because if I but you know or + + + align:start position:0% +by right because if I but you know or +say + + align:start position:0% +say + + + align:start position:0% +say +linear colloquially linear right right + + align:start position:0% +linear colloquially linear right right + + + align:start position:0% +linear colloquially linear right right +because because you equivalently you're + + align:start position:0% +because because you equivalently you're + + + align:start position:0% +because because you equivalently you're +approximating it by FR Prime of X Plus + + align:start position:0% +approximating it by FR Prime of X Plus + + + align:start position:0% +approximating it by FR Prime of X Plus +um plus your F primed of x uh you know + + align:start position:0% +um plus your F primed of x uh you know + + + align:start position:0% +um plus your F primed of x uh you know +Delta + + align:start position:0% +Delta + + + align:start position:0% +Delta +X + + align:start position:0% +X + + + align:start position:0% +X +right and so if you're finding a root of + + align:start position:0% +right and so if you're finding a root of + + + align:start position:0% +right and so if you're finding a root of +a linear + + align:start position:0% +a linear + + + align:start position:0% +a linear +function you have non trying to find the + + align:start position:0% +function you have non trying to find the + + + align:start position:0% +function you have non trying to find the +root of a nonlinear function grad F and + + align:start position:0% +root of a nonlinear function grad F and + + + align:start position:0% +root of a nonlinear function grad F and +you approximate it by a linear thing and + + align:start position:0% +you approximate it by a linear thing and + + + align:start position:0% +you approximate it by a linear thing and +you find a root of that what's the name + + align:start position:0% +you find a root of that what's the name + + + align:start position:0% +you find a root of that what's the name +for that + + align:start position:0% +for that + + + align:start position:0% +for that +method Newton's method so this is just + + align:start position:0% +method Newton's method so this is just + + + align:start position:0% +method Newton's method so this is just +Newton's + + align:start position:0% + + + + align:start position:0% + +method right and uh so in in + + align:start position:0% +method right and uh so in in + + + align:start position:0% +method right and uh so in in +practice uh finding the + + align:start position:0% +practice uh finding the + + + align:start position:0% +practice uh finding the +Hessian or finding the the F Prime uh um + + align:start position:0% +Hessian or finding the the F Prime uh um + + + align:start position:0% +Hessian or finding the the F Prime uh um +uh + + align:start position:0% +uh + + + align:start position:0% +uh +or or the Hessian + + align:start position:0% + + + + align:start position:0% + +matrix is is often + + align:start position:0% + + + + align:start position:0% + +expensive if you have if F ofx again + + align:start position:0% +expensive if you have if F ofx again + + + align:start position:0% +expensive if you have if F ofx again +takes a a a a RN to a + + align:start position:0% +takes a a a a RN to a + + + align:start position:0% +takes a a a a RN to a +scaler then um H is an N byn + + align:start position:0% +scaler then um H is an N byn + + + align:start position:0% +scaler then um H is an N byn +Matrix and this is + + align:start position:0% + + + + align:start position:0% + +huge if n is large l so if you have a + + align:start position:0% +huge if n is large l so if you have a + + + align:start position:0% +huge if n is large l so if you have a +neural network with aill is a billion + + align:start position:0% +neural network with aill is a billion + + + align:start position:0% +neural network with aill is a billion +the Hassan is a billion by million + + align:start position:0% +the Hassan is a billion by million + + + align:start position:0% +the Hassan is a billion by million +Matrix you can't even store this Matrix + + align:start position:0% +Matrix you can't even store this Matrix + + + align:start position:0% +Matrix you can't even store this Matrix +much less comput it so it's it's it's + + align:start position:0% +much less comput it so it's it's it's + + + align:start position:0% +much less comput it so it's it's it's +it's hard to get exactly for in in I + + align:start position:0% +it's hard to get exactly for in in I + + + align:start position:0% +it's hard to get exactly for in in I +guess say in high + + align:start position:0% + + + + align:start position:0% + +Dimensions so often what you try and do + + align:start position:0% +Dimensions so often what you try and do + + + align:start position:0% +Dimensions so often what you try and do +is you try and + + align:start position:0% +is you try and + + + align:start position:0% +is you try and +approximate if you don't want to give up + + align:start position:0% +approximate if you don't want to give up + + + align:start position:0% +approximate if you don't want to give up +on it entirely you + + align:start position:0% + + + + align:start position:0% + +approximate the + + align:start position:0% +approximate the + + + align:start position:0% +approximate the +Hessian uh uh in various + + align:start position:0% + + + + align:start position:0% + +ways + + align:start position:0% +ways + + + align:start position:0% +ways +and so these these give you rise to a + + align:start position:0% +and so these these give you rise to a + + + align:start position:0% +and so these these give you rise to a +variety of methods called quasi Newton + + align:start position:0% + + + + align:start position:0% + +methods uh + + align:start position:0% +methods uh + + + align:start position:0% +methods uh +methods that the most famous of which is + + align:start position:0% +methods that the most famous of which is + + + align:start position:0% +methods that the most famous of which is +called the bfgs method which is like + + align:start position:0% +called the bfgs method which is like + + + align:start position:0% +called the bfgs method which is like +Bren Fletcher goldb and Shannon I think + + align:start position:0% +Bren Fletcher goldb and Shannon I think + + + align:start position:0% +Bren Fletcher goldb and Shannon I think +it's named after four people who + + align:start position:0% +it's named after four people who + + + align:start position:0% +it's named after four people who +amusingly discovered the same thing in + + align:start position:0% +amusingly discovered the same thing in + + + align:start position:0% +amusingly discovered the same thing in +the same year independently like there's + + align:start position:0% +the same year independently like there's + + + align:start position:0% +the same year independently like there's +like there's three three or four + + align:start position:0% +like there's three three or four + + + align:start position:0% +like there's three three or four +separate + + align:start position:0% +separate + + + align:start position:0% +separate +papers on the same thing there there's + + align:start position:0% +papers on the same thing there there's + + + align:start position:0% +papers on the same thing there there's +also a closely related method called uh + + align:start position:0% +also a closely related method called uh + + + align:start position:0% +also a closely related method called uh +Newton kroff + + align:start position:0% + + + + align:start position:0% + +methods + + align:start position:0% +methods + + + align:start position:0% +methods +right and so forth so you know I don't + + align:start position:0% +right and so forth so you know I don't + + + align:start position:0% +right and so forth so you know I don't +don't have time to explain all these + + align:start position:0% +don't have time to explain all these + + + align:start position:0% +don't have time to explain all these +things but you know this + + align:start position:0% +things but you know this + + + align:start position:0% +things but you know this +is these are some key wordss if you ever + + align:start position:0% +is these are some key wordss if you ever + + + align:start position:0% +is these are some key wordss if you ever +need to do this so you know Hessians are + + align:start position:0% +need to do this so you know Hessians are + + + align:start position:0% +need to do this so you know Hessians are +useful for small n you can compute them + + align:start position:0% +useful for small n you can compute them + + + align:start position:0% +useful for small n you can compute them +explicitly by even automatic + + align:start position:0% +explicitly by even automatic + + + align:start position:0% +explicitly by even automatic +differentiation can get hens for you but + + align:start position:0% +differentiation can get hens for you but + + + align:start position:0% +differentiation can get hens for you but +for big ends you can't even store it + + align:start position:0% +for big ends you can't even store it + + + align:start position:0% +for big ends you can't even store it +much less compute it so then there are + + align:start position:0% +much less compute it so then there are + + + align:start position:0% +much less compute it so then there are +ways to kind of and it's a really + + align:start position:0% +ways to kind of and it's a really + + + align:start position:0% +ways to kind of and it's a really +intricate problem to approximate + + align:start position:0% +intricate problem to approximate + + + align:start position:0% +intricate problem to approximate +Hessians or you can you can compute the + + align:start position:0% +Hessians or you can you can compute the + + + align:start position:0% +Hessians or you can you can compute the +hessan times in a particular direction + + align:start position:0% +hessan times in a particular direction + + + align:start position:0% +hessan times in a particular direction +quickly like aian times a operated on a + + align:start position:0% +quickly like aian times a operated on a + + + align:start position:0% +quickly like aian times a operated on a +DX that that you can get quickly + + align:start position:0% +DX that that you can get quickly + + + align:start position:0% +DX that that you can get quickly +um but um yeah + + align:start position:0% + + + + align:start position:0% + +so \ No newline at end of file diff --git a/QcUUGlsSXmY.txt b/QcUUGlsSXmY.txt new file mode 100644 index 0000000000000000000000000000000000000000..66dd7ef174430a66150d86f2a1ffb67f47db569f --- /dev/null +++ b/QcUUGlsSXmY.txt @@ -0,0 +1,11675 @@ +align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +so let's get started today first of all + + align:start position:0% +so let's get started today first of all + + + align:start position:0% +so let's get started today first of all +are there any questions from last time + + align:start position:0% +are there any questions from last time + + + align:start position:0% +are there any questions from last time +all right so please feel free to ask + + align:start position:0% +all right so please feel free to ask + + + align:start position:0% +all right so please feel free to ask +questions along the way in terms of the + + align:start position:0% +questions along the way in terms of the + + + align:start position:0% +questions along the way in terms of the +reading list for up to lecture nine + + align:start position:0% +reading list for up to lecture nine + + + align:start position:0% +reading list for up to lecture nine +today we're sharing with production it's + + align:start position:0% +today we're sharing with production it's + + + align:start position:0% +today we're sharing with production it's +our second lecture on applications there + + align:start position:0% +our second lecture on applications there + + + align:start position:0% +our second lecture on applications there +are two starred papers and we're going + + align:start position:0% +are two starred papers and we're going + + + align:start position:0% +are two starred papers and we're going +to be going through the first one with + + align:start position:0% +to be going through the first one with + + + align:start position:0% +to be going through the first one with +some Panther Rock and some detail and + + align:start position:0% +some Panther Rock and some detail and + + + align:start position:0% +some Panther Rock and some detail and +then a few selected slides on the Canon + + align:start position:0% +then a few selected slides on the Canon + + + align:start position:0% +then a few selected slides on the Canon +at Al paper but like all starred papers + + align:start position:0% +at Al paper but like all starred papers + + + align:start position:0% +at Al paper but like all starred papers +I hope you will be reading them because + + align:start position:0% +I hope you will be reading them because + + + align:start position:0% +I hope you will be reading them because +I know you're very well trained now and + + align:start position:0% +I know you're very well trained now and + + + align:start position:0% +I know you're very well trained now and +you will be able to read those articles + + align:start position:0% +you will be able to read those articles + + + align:start position:0% +you will be able to read those articles +so think you would get a lot out of it + + align:start position:0% +so think you would get a lot out of it + + + align:start position:0% +so think you would get a lot out of it +but we will cover most of it today + + align:start position:0% +but we will cover most of it today + + + align:start position:0% +but we will cover most of it today +the other thing + + align:start position:0% +the other thing + + + align:start position:0% +the other thing +for the study guide + + align:start position:0% +for the study guide + + + align:start position:0% +for the study guide +so let me ask you guys some + + align:start position:0% +so let me ask you guys some + + + align:start position:0% +so let me ask you guys some +questions + + align:start position:0% +questions + + + align:start position:0% +questions +last time was our first applied lecture + + align:start position:0% +last time was our first applied lecture + + + align:start position:0% +last time was our first applied lecture +on resharing we did it in both Village + + align:start position:0% +on resharing we did it in both Village + + + align:start position:0% +on resharing we did it in both Village +India and medieval villages + + align:start position:0% +India and medieval villages + + + align:start position:0% +India and medieval villages +and today I want to + + align:start position:0% +and today I want to + + + align:start position:0% +and today I want to +give a little bit more emphasis to the + + align:start position:0% +give a little bit more emphasis to the + + + align:start position:0% +give a little bit more emphasis to the +economics combined with the analysis + + align:start position:0% +economics combined with the analysis + + + align:start position:0% +economics combined with the analysis +more than I usually do but it seems like + + align:start position:0% +more than I usually do but it seems like + + + align:start position:0% +more than I usually do but it seems like +the time to do that since we're talking + + align:start position:0% +the time to do that since we're talking + + + align:start position:0% +the time to do that since we're talking +about applications + + align:start position:0% +about applications + + + align:start position:0% +about applications +so the first one I picked here + + align:start position:0% +so the first one I picked here + + + align:start position:0% +so the first one I picked here +describing words why villages in India + + align:start position:0% +describing words why villages in India + + + align:start position:0% +describing words why villages in India +are a risky place + + align:start position:0% +are a risky place + + + align:start position:0% +are a risky place +how to quantify that risk and its + + align:start position:0% +how to quantify that risk and its + + + align:start position:0% +how to quantify that risk and its +sources + + align:start position:0% +sources + + + align:start position:0% +sources +and how that risk might be mitigated or + + align:start position:0% +and how that risk might be mitigated or + + + align:start position:0% +and how that risk might be mitigated or +potentially + + align:start position:0% +potentially + + + align:start position:0% +potentially +well mitigated via individual or social + + align:start position:0% +well mitigated via individual or social + + + align:start position:0% +well mitigated via individual or social +diversification + + align:start position:0% +diversification + + + align:start position:0% +diversification +so I have lately been taking + + align:start position:0% +so I have lately been taking + + + align:start position:0% +so I have lately been taking +volunteers uh but let me ask Dixon do + + align:start position:0% +volunteers uh but let me ask Dixon do + + + align:start position:0% +volunteers uh but let me ask Dixon do +you want to take a stab at that + + align:start position:0% +you want to take a stab at that + + + align:start position:0% +you want to take a stab at that +yeah sure uh so Villages are a risky + + align:start position:0% +yeah sure uh so Villages are a risky + + + align:start position:0% +yeah sure uh so Villages are a risky +place because + + align:start position:0% +place because + + + align:start position:0% +place because +um it's mostly Agriculture and it's not + + align:start position:0% +um it's mostly Agriculture and it's not + + + align:start position:0% +um it's mostly Agriculture and it's not +a stable source of income + + align:start position:0% +a stable source of income + + + align:start position:0% +a stable source of income +and I think we can quantify that risk by + + align:start position:0% +and I think we can quantify that risk by + + + align:start position:0% +and I think we can quantify that risk by +just looking at like the variation + + align:start position:0% +just looking at like the variation + + + align:start position:0% +just looking at like the variation +through the years and how it like really + + align:start position:0% +through the years and how it like really + + + align:start position:0% +through the years and how it like really +changes + + align:start position:0% +changes + + + align:start position:0% +changes +um and how a lot of things are like + + align:start position:0% +um and how a lot of things are like + + + align:start position:0% +um and how a lot of things are like +linked with each other in terms of their + + align:start position:0% +linked with each other in terms of their + + + align:start position:0% +linked with each other in terms of their +risk and it can be mitigated by + + align:start position:0% +risk and it can be mitigated by + + + align:start position:0% +risk and it can be mitigated by +um like + + align:start position:0% +um like + + + align:start position:0% +um like +planting different kinds of like plants + + align:start position:0% +planting different kinds of like plants + + + align:start position:0% +planting different kinds of like plants +or like + + align:start position:0% +or like + + + align:start position:0% +or like +um planting like far apart that's + + align:start position:0% +um planting like far apart that's + + + align:start position:0% +um planting like far apart that's +individually in Social diversification + + align:start position:0% +individually in Social diversification + + + align:start position:0% +individually in Social diversification +like giving gifts or transfers + + align:start position:0% +like giving gifts or transfers + + + align:start position:0% +like giving gifts or transfers +come on yeah + + align:start position:0% +come on yeah + + + align:start position:0% +come on yeah +very very good answer + + align:start position:0% +very very good answer + + + align:start position:0% +very very good answer +thank you so + + align:start position:0% +thank you so + + + align:start position:0% +thank you so +yeah we Quantified the risk by the + + align:start position:0% +yeah we Quantified the risk by the + + + align:start position:0% +yeah we Quantified the risk by the +coefficient of variation of a given crop + + align:start position:0% +coefficient of variation of a given crop + + + align:start position:0% +coefficient of variation of a given crop +or a given crop in a certain soil type + + align:start position:0% +or a given crop in a certain soil type + + + align:start position:0% +or a given crop in a certain soil type +or a certain + + align:start position:0% +or a certain + + + align:start position:0% +or a certain +income source + + align:start position:0% +income source + + + align:start position:0% +income source +just to add a few more details your + + align:start position:0% +just to add a few more details your + + + align:start position:0% +just to add a few more details your +answer was fine + + align:start position:0% +answer was fine + + + align:start position:0% +answer was fine +the the covariance across those things + + align:start position:0% +the the covariance across those things + + + align:start position:0% +the the covariance across those things +actually helps mitigate the risk and + + align:start position:0% +actually helps mitigate the risk and + + + align:start position:0% +actually helps mitigate the risk and +that's what you're saying when you to + + align:start position:0% +that's what you're saying when you to + + + align:start position:0% +that's what you're saying when you to +different crops or different spots on + + align:start position:0% +different crops or different spots on + + + align:start position:0% +different crops or different spots on +the field + + align:start position:0% +the field + + + align:start position:0% +the field +those are ex-antees so there's like + + align:start position:0% +those are ex-antees so there's like + + + align:start position:0% +those are ex-antees so there's like +individual + + align:start position:0% +individual + + + align:start position:0% +individual +things that people can do and the expose + + align:start position:0% +things that people can do and the expose + + + align:start position:0% +things that people can do and the expose +social diversification is the gifts + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +next one comparing incomes over + + align:start position:0% +next one comparing incomes over + + + align:start position:0% +next one comparing incomes over +households and time + + align:start position:0% +households and time + + + align:start position:0% +households and time +with consumption over households in time + + align:start position:0% +with consumption over households in time + + + align:start position:0% +with consumption over households in time +what can you infer from the data alone + + align:start position:0% +what can you infer from the data alone + + + align:start position:0% +what can you infer from the data alone +so let me stop there and not read the + + align:start position:0% +so let me stop there and not read the + + + align:start position:0% +so let me stop there and not read the +second part + + align:start position:0% +second part + + + align:start position:0% +second part +let's see who would like to + + align:start position:0% +let's see who would like to + + + align:start position:0% +let's see who would like to +Charles do you want to take a stab at + + align:start position:0% +Charles do you want to take a stab at + + + align:start position:0% +Charles do you want to take a stab at +that are you there yeah + + align:start position:0% +that are you there yeah + + + align:start position:0% +that are you there yeah +um let me think remember correctly is + + align:start position:0% +um let me think remember correctly is + + + align:start position:0% +um let me think remember correctly is +this something like uh you could sort of + + align:start position:0% +this something like uh you could sort of + + + align:start position:0% +this something like uh you could sort of +like compare like the incomes which is + + align:start position:0% +like compare like the incomes which is + + + align:start position:0% +like compare like the incomes which is +basically the part risk and what you end + + align:start position:0% +basically the part risk and what you end + + + align:start position:0% +basically the part risk and what you end +up end of the way you end up receiving + + align:start position:0% +up end of the way you end up receiving + + + align:start position:0% +up end of the way you end up receiving +and like I remember there's like you can + + align:start position:0% +and like I remember there's like you can + + + align:start position:0% +and like I remember there's like you can +you can infer from you can see that it's + + align:start position:0% +you can infer from you can see that it's + + + align:start position:0% +you can infer from you can see that it's +definitely much the the what you end up + + align:start position:0% +definitely much the the what you end up + + + align:start position:0% +definitely much the the what you end up +getting it's much flatter within what + + align:start position:0% +getting it's much flatter within what + + + align:start position:0% +getting it's much flatter within what +then was produced so there's so I guess + + align:start position:0% +then was produced so there's so I guess + + + align:start position:0% +then was produced so there's so I guess +I'm trying to answer the second part of + + align:start position:0% +I'm trying to answer the second part of + + + align:start position:0% +I'm trying to answer the second part of +the question like now but like that that + + align:start position:0% +the question like now but like that that + + + align:start position:0% +the question like now but like that that +sort of like is data that suggested with + + align:start position:0% +sort of like is data that suggested with + + + align:start position:0% +sort of like is data that suggested with +sharing I don't + + align:start position:0% +sharing I don't + + + align:start position:0% +sharing I don't +I don't think that's enough to prove + + align:start position:0% +I don't think that's enough to prove + + + align:start position:0% +I don't think that's enough to prove +causation it was definitely suggestive + + align:start position:0% +causation it was definitely suggestive + + + align:start position:0% +causation it was definitely suggestive +yeah that's good the second part + + align:start position:0% +yeah that's good the second part + + + align:start position:0% +yeah that's good the second part +uh maybe the second sentence helps + + align:start position:0% +uh maybe the second sentence helps + + + align:start position:0% +uh maybe the second sentence helps +if average consumption of households + + align:start position:0% +if average consumption of households + + + align:start position:0% +if average consumption of households +increased when average income of + + align:start position:0% +increased when average income of + + + align:start position:0% +increased when average income of +households increased + + align:start position:0% +households increased + + + align:start position:0% +households increased +would that be consistent with resharing + + align:start position:0% +would that be consistent with resharing + + + align:start position:0% +would that be consistent with resharing +or not + + align:start position:0% + + + + align:start position:0% + +uh for me yeah for you + + align:start position:0% +uh for me yeah for you + + + align:start position:0% +uh for me yeah for you +so okay so if so okay average exception + + align:start position:0% +so okay so if so okay average exception + + + align:start position:0% +so okay so if so okay average exception +of how to increase but + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +I wouldn't like completely like + + align:start position:0% +I wouldn't like completely like + + + align:start position:0% +I wouldn't like completely like +annihilate everything but so like I + + align:start position:0% +annihilate everything but so like I + + + align:start position:0% +annihilate everything but so like I +don't think that would be enough that + + align:start position:0% +don't think that would be enough that + + + align:start position:0% +don't think that would be enough that +would I think that would still be + + align:start position:0% +would I think that would still be + + + align:start position:0% +would I think that would still be +consistent with some level right + + align:start position:0% +consistent with some level right + + + align:start position:0% +consistent with some level right +yeah it's not uh it's actually a + + align:start position:0% +yeah it's not uh it's actually a + + + align:start position:0% +yeah it's not uh it's actually a +sentence is not terribly well worded but + + align:start position:0% +sentence is not terribly well worded but + + + align:start position:0% +sentence is not terribly well worded but +it is + + align:start position:0% +it is + + + align:start position:0% +it is +you know worthwhile to clarify + + align:start position:0% +you know worthwhile to clarify + + + align:start position:0% +you know worthwhile to clarify +you know so the first part that we + + align:start position:0% +you know so the first part that we + + + align:start position:0% +you know so the first part that we +looked at is just the levels of stuff + + align:start position:0% +looked at is just the levels of stuff + + + align:start position:0% +looked at is just the levels of stuff +over households and over time + + align:start position:0% +over households and over time + + + align:start position:0% +over households and over time +we referred to the Rocky Mountain + + align:start position:0% +we referred to the Rocky Mountain + + + align:start position:0% +we referred to the Rocky Mountain +picture as + + align:start position:0% +picture as + + + align:start position:0% +picture as +incomes going up concealing the valley + + align:start position:0% +incomes going up concealing the valley + + + align:start position:0% +incomes going up concealing the valley +behind + + align:start position:0% +behind + + + align:start position:0% +behind +and very uh very Jagged Rocky pictures + + align:start position:0% +and very uh very Jagged Rocky pictures + + + align:start position:0% +and very uh very Jagged Rocky pictures +as opposed to consumption + + align:start position:0% +as opposed to consumption + + + align:start position:0% +as opposed to consumption +which was very flat and we were even + + align:start position:0% +which was very flat and we were even + + + align:start position:0% +which was very flat and we were even +joking around a bit you know very boring + + align:start position:0% +joking around a bit you know very boring + + + align:start position:0% +joking around a bit you know very boring +as in Kansas + + align:start position:0% +as in Kansas + + + align:start position:0% +as in Kansas +so then the issue would be with the + + align:start position:0% +so then the issue would be with the + + + align:start position:0% +so then the issue would be with the +theory that we're about to look at apart + + align:start position:0% +theory that we're about to look at apart + + + align:start position:0% +theory that we're about to look at apart +from the data alone + + align:start position:0% +from the data alone + + + align:start position:0% +from the data alone +would you think household consumption + + align:start position:0% +would you think household consumption + + + align:start position:0% +would you think household consumption +ought to move with household income + + align:start position:0% +ought to move with household income + + + align:start position:0% +ought to move with household income +actually I think there's a question + + align:start position:0% +actually I think there's a question + + + align:start position:0% +actually I think there's a question +below and what's ambiguous about that + + align:start position:0% +below and what's ambiguous about that + + + align:start position:0% +below and what's ambiguous about that +sentence is household consumptions + + align:start position:0% +sentence is household consumptions + + + align:start position:0% +sentence is household consumptions +increase with average household average + + align:start position:0% +increase with average household average + + + align:start position:0% +increase with average household average +income of households + + align:start position:0% +income of households + + + align:start position:0% +income of households +yeah that's very treacherously worded I + + align:start position:0% +yeah that's very treacherously worded I + + + align:start position:0% +yeah that's very treacherously worded I +mean average income meaning overall the + + align:start position:0% +mean average income meaning overall the + + + align:start position:0% +mean average income meaning overall the +dates of a given household that kind of + + align:start position:0% +dates of a given household that kind of + + + align:start position:0% +dates of a given household that kind of +sets the levels of things and maybe you + + align:start position:0% +sets the levels of things and maybe you + + + align:start position:0% +sets the levels of things and maybe you +know that uh my household will hire + + align:start position:0% +know that uh my household will hire + + + align:start position:0% +know that uh my household will hire +average + + align:start position:0% +average + + + align:start position:0% +average +income over time has a higher average + + align:start position:0% +income over time has a higher average + + + align:start position:0% +income over time has a higher average +consumption over time + + align:start position:0% +consumption over time + + + align:start position:0% +consumption over time +and I'll I'll ask for volunteers + + align:start position:0% +and I'll I'll ask for volunteers + + + align:start position:0% +and I'll I'll ask for volunteers +if we we have this regression where we + + align:start position:0% +if we we have this regression where we + + + align:start position:0% +if we we have this regression where we +run household consumption on the left as + + align:start position:0% +run household consumption on the left as + + + align:start position:0% +run household consumption on the left as +a dependent variable onto aggregate + + align:start position:0% +a dependent variable onto aggregate + + + align:start position:0% +a dependent variable onto aggregate +consumption and individual income on the + + align:start position:0% +consumption and individual income on the + + + align:start position:0% +consumption and individual income on the +right throwing in some intercepts so + + align:start position:0% +right throwing in some intercepts so + + + align:start position:0% +right throwing in some intercepts so +what restrictions from the theory are + + align:start position:0% +what restrictions from the theory are + + + align:start position:0% +what restrictions from the theory are +placed on the coefficient + + align:start position:0% +placed on the coefficient + + + align:start position:0% +placed on the coefficient +of individual income + + align:start position:0% +of individual income + + + align:start position:0% +of individual income +and I'll take a volunteer for that + + align:start position:0% +and I'll take a volunteer for that + + + align:start position:0% +and I'll take a volunteer for that +I think the the coefficient individual + + align:start position:0% +I think the the coefficient individual + + + align:start position:0% +I think the the coefficient individual +come should be + + align:start position:0% + + + + align:start position:0% + +suggested really + + align:start position:0% +suggested really + + + align:start position:0% +suggested really +really aggregate consumption aggregate + + align:start position:0% +really aggregate consumption aggregate + + + align:start position:0% +really aggregate consumption aggregate +in average income of the household + + align:start position:0% +in average income of the household + + + align:start position:0% +in average income of the household +and I have a question here is that I + + align:start position:0% +and I have a question here is that I + + + align:start position:0% +and I have a question here is that I +remember in these slides I say that when + + align:start position:0% +remember in these slides I say that when + + + align:start position:0% +remember in these slides I say that when +all the household held the same risk + + align:start position:0% +all the household held the same risk + + + align:start position:0% +all the household held the same risk +aversion then the coefficient between + + align:start position:0% +aversion then the coefficient between + + + align:start position:0% +aversion then the coefficient between +the aggregate + + align:start position:0% + + + + align:start position:0% + +between the aggregate consumption should + + align:start position:0% +between the aggregate consumption should + + + align:start position:0% +between the aggregate consumption should +be one + + align:start position:0% +be one + + + align:start position:0% +be one +yeah but but I why + + align:start position:0% +yeah but but I why + + + align:start position:0% +yeah but but I why +I think the coefficient on the average + + align:start position:0% +I think the coefficient on the average + + + align:start position:0% +I think the coefficient on the average +consumption should be when not the + + align:start position:0% +consumption should be when not the + + + align:start position:0% +consumption should be when not the +aggregate consumption + + align:start position:0% + + + + align:start position:0% + +oh well there's a say a fixed number of + + align:start position:0% +oh well there's a say a fixed number of + + + align:start position:0% +oh well there's a say a fixed number of +households or taking + + align:start position:0% +households or taking + + + align:start position:0% +households or taking +the Aggregate and dividing by the number + + align:start position:0% +the Aggregate and dividing by the number + + + align:start position:0% +the Aggregate and dividing by the number +of households gives you the average + + align:start position:0% +of households gives you the average + + + align:start position:0% +of households gives you the average +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +it's just a re-normalization of the + + align:start position:0% +it's just a re-normalization of the + + + align:start position:0% +it's just a re-normalization of the +units that's all but it's you're right + + align:start position:0% +units that's all but it's you're right + + + align:start position:0% +units that's all but it's you're right +that it's meant to represent the + + align:start position:0% +that it's meant to represent the + + + align:start position:0% +that it's meant to represent the +aggregate + + align:start position:0% +aggregate + + + align:start position:0% +aggregate +um + + align:start position:0% +um + + + align:start position:0% +um +so so you can think of it that way + + align:start position:0% +so so you can think of it that way + + + align:start position:0% +so so you can think of it that way +because the economics makes more sense + + align:start position:0% +because the economics makes more sense + + + align:start position:0% +because the economics makes more sense +the aggregate + + align:start position:0% +the aggregate + + + align:start position:0% +the aggregate +is going up + + align:start position:0% +is going up + + + align:start position:0% +is going up +coming up over all the individuals + + align:start position:0% +coming up over all the individuals + + + align:start position:0% +coming up over all the individuals +and if there's + + align:start position:0% +and if there's + + + align:start position:0% +and if there's +constant absolute risk conversion and + + align:start position:0% +constant absolute risk conversion and + + + align:start position:0% +constant absolute risk conversion and +the same risk aversion for all the + + align:start position:0% +the same risk aversion for all the + + + align:start position:0% +the same risk aversion for all the +households + + align:start position:0% +households + + + align:start position:0% +households +and whenever the aggregate goes up every + + align:start position:0% +and whenever the aggregate goes up every + + + align:start position:0% +and whenever the aggregate goes up every +individual household consumption goes up + + align:start position:0% +individual household consumption goes up + + + align:start position:0% +individual household consumption goes up +one to one yeah yeah which is what you + + align:start position:0% +one to one yeah yeah which is what you + + + align:start position:0% +one to one yeah yeah which is what you +said okay + + align:start position:0% +said okay + + + align:start position:0% +said okay +thank you + + align:start position:0% +thank you + + + align:start position:0% +thank you +yeah and the emphasis here is the + + align:start position:0% +yeah and the emphasis here is the + + + align:start position:0% +yeah and the emphasis here is the +household specific income + + align:start position:0% +household specific income + + + align:start position:0% +household specific income +it has a coefficient of zero that's the + + align:start position:0% +it has a coefficient of zero that's the + + + align:start position:0% +it has a coefficient of zero that's the +kind of salient + + align:start position:0% +kind of salient + + + align:start position:0% +kind of salient +restriction that the theory places on + + align:start position:0% +restriction that the theory places on + + + align:start position:0% +restriction that the theory places on +the data + + align:start position:0% +the data + + + align:start position:0% +the data +as well + + align:start position:0% +as well + + + align:start position:0% +as well +okay and then finally + + align:start position:0% +okay and then finally + + + align:start position:0% +okay and then finally +he looked at the division of land + + align:start position:0% +he looked at the division of land + + + align:start position:0% +he looked at the division of land +in these medieval village + + align:start position:0% +in these medieval village + + + align:start position:0% +in these medieval village +and the question is + + align:start position:0% +and the question is + + + align:start position:0% +and the question is +with scattering of an individual + + align:start position:0% +with scattering of an individual + + + align:start position:0% +with scattering of an individual +households plots across the different + + align:start position:0% +households plots across the different + + + align:start position:0% +households plots across the different +fields + + align:start position:0% +fields + + + align:start position:0% +fields +be enough to achieve an optimal + + align:start position:0% +be enough to achieve an optimal + + + align:start position:0% +be enough to achieve an optimal +allocation of risk bearing Paolo do you + + align:start position:0% +allocation of risk bearing Paolo do you + + + align:start position:0% +allocation of risk bearing Paolo do you +want to take a crack at that + + align:start position:0% +want to take a crack at that + + + align:start position:0% +want to take a crack at that +um sure I think the answer is no just + + align:start position:0% +um sure I think the answer is no just + + + align:start position:0% +um sure I think the answer is no just +because + + align:start position:0% +because + + + align:start position:0% +because +um it's not necessarily that each field + + align:start position:0% +um it's not necessarily that each field + + + align:start position:0% +um it's not necessarily that each field +is a random + + align:start position:0% +is a random + + + align:start position:0% +is a random +um draw you can have correlations like + + align:start position:0% +um draw you can have correlations like + + + align:start position:0% +um draw you can have correlations like +it's just like a trappier and there's + + align:start position:0% +it's just like a trappier and there's + + + align:start position:0% +it's just like a trappier and there's +like no ring anywhere that's a like Risk + + align:start position:0% +like no ring anywhere that's a like Risk + + + align:start position:0% +like no ring anywhere that's a like Risk +which would like be a shock to all of + + align:start position:0% +which would like be a shock to all of + + + align:start position:0% +which would like be a shock to all of +your crops essentially + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +um so it's correct that it's not + + align:start position:0% +um so it's correct that it's not + + + align:start position:0% +um so it's correct that it's not +necessarily enough unless you have very + + align:start position:0% +necessarily enough unless you have very + + + align:start position:0% +necessarily enough unless you have very +special + + align:start position:0% +special + + + align:start position:0% +special +characteristics of those of those plots + + align:start position:0% +characteristics of those of those plots + + + align:start position:0% +characteristics of those of those plots +um + + align:start position:0% +um + + + align:start position:0% +um +how they move with various states of the + + align:start position:0% +how they move with various states of the + + + align:start position:0% +how they move with various states of the +world + + align:start position:0% +world + + + align:start position:0% +world +in the lecture we gave an example + + align:start position:0% +in the lecture we gave an example + + + align:start position:0% +in the lecture we gave an example +um + + align:start position:0% +um + + + align:start position:0% +um +two examples really + + align:start position:0% +two examples really + + + align:start position:0% +two examples really +uh one where there are two types of land + + align:start position:0% +uh one where there are two types of land + + + align:start position:0% +uh one where there are two types of land +and um + + align:start position:0% +and um + + + align:start position:0% +and um +both are increasing as the states + + align:start position:0% +both are increasing as the states + + + align:start position:0% +both are increasing as the states +increase + + align:start position:0% +increase + + + align:start position:0% +increase +um + + align:start position:0% +um + + + align:start position:0% +um +and then + + align:start position:0% +and then + + + align:start position:0% +and then +it would be enough to kind of have each + + align:start position:0% +it would be enough to kind of have each + + + align:start position:0% +it would be enough to kind of have each +household have + + align:start position:0% +household have + + + align:start position:0% +household have +uh a share a constant share over the two + + align:start position:0% +uh a share a constant share over the two + + + align:start position:0% +uh a share a constant share over the two +types of land + + align:start position:0% +types of land + + + align:start position:0% +types of land +that would result in a linear risk + + align:start position:0% +that would result in a linear risk + + + align:start position:0% +that would result in a linear risk +sharing schedule + + align:start position:0% +sharing schedule + + + align:start position:0% +sharing schedule +so for certain utility functions + + align:start position:0% +so for certain utility functions + + + align:start position:0% +so for certain utility functions +including you know + + align:start position:0% +including you know + + + align:start position:0% +including you know +an examination of the slope in the + + align:start position:0% +an examination of the slope in the + + + align:start position:0% +an examination of the slope in the +intercepts that would be enough + + align:start position:0% + + + + align:start position:0% + +so in special cases it might work + + align:start position:0% +so in special cases it might work + + + align:start position:0% +so in special cases it might work +but in general you have two different + + align:start position:0% +but in general you have two different + + + align:start position:0% +but in general you have two different +types of land and output goes up in one + + align:start position:0% +types of land and output goes up in one + + + align:start position:0% +types of land and output goes up in one +it may go down in the other depending on + + align:start position:0% +it may go down in the other depending on + + + align:start position:0% +it may go down in the other depending on +the state of the world + + align:start position:0% +the state of the world + + + align:start position:0% +the state of the world +in which case you know handing out + + align:start position:0% +in which case you know handing out + + + align:start position:0% +in which case you know handing out +shares of each type + + align:start position:0% +shares of each type + + + align:start position:0% +shares of each type +uh is is not going to work necessarily + + align:start position:0% +uh is is not going to work necessarily + + + align:start position:0% +uh is is not going to work necessarily +and we explore that further in the + + align:start position:0% +and we explore that further in the + + + align:start position:0% +and we explore that further in the +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +so that whole lecture kind of culminated + + align:start position:0% +so that whole lecture kind of culminated + + + align:start position:0% +so that whole lecture kind of culminated +at the end + + align:start position:0% +at the end + + + align:start position:0% +at the end +with an example where we had + + align:start position:0% +with an example where we had + + + align:start position:0% +with an example where we had +um + + align:start position:0% +um + + + align:start position:0% +um +more states of the world than we had + + align:start position:0% +more states of the world than we had + + + align:start position:0% +more states of the world than we had +land types + + align:start position:0% +land types + + + align:start position:0% +land types +and uh restricted them to + + align:start position:0% +and uh restricted them to + + + align:start position:0% +and uh restricted them to +having shares of each type + + align:start position:0% +having shares of each type + + + align:start position:0% +having shares of each type +as if they could not transfer stuff + + align:start position:0% +as if they could not transfer stuff + + + align:start position:0% +as if they could not transfer stuff +around and + + align:start position:0% +around and + + + align:start position:0% +around and +it was clear that it was constrained + + align:start position:0% +it was clear that it was constrained + + + align:start position:0% +it was clear that it was constrained +optimal + + align:start position:0% +optimal + + + align:start position:0% +optimal +so taking that allocation of land with + + align:start position:0% +so taking that allocation of land with + + + align:start position:0% +so taking that allocation of land with +the Harvest as given we could do better + + align:start position:0% +the Harvest as given we could do better + + + align:start position:0% +the Harvest as given we could do better +by add to Welfare by having exposed + + align:start position:0% +by add to Welfare by having exposed + + + align:start position:0% +by add to Welfare by having exposed +redistribution of the grain via + + align:start position:0% +redistribution of the grain via + + + align:start position:0% +redistribution of the grain via +transfers okay so that's probably enough + + align:start position:0% +transfers okay so that's probably enough + + + align:start position:0% +transfers okay so that's probably enough +of a review as always there are many + + align:start position:0% +of a review as always there are many + + + align:start position:0% +of a review as always there are many +more questions in the study guide and + + align:start position:0% +more questions in the study guide and + + + align:start position:0% +more questions in the study guide and +probably spent quite a lot of time just + + align:start position:0% +probably spent quite a lot of time just + + + align:start position:0% +probably spent quite a lot of time just +deciding which ones to ask in class you + + align:start position:0% +deciding which ones to ask in class you + + + align:start position:0% +deciding which ones to ask in class you +should look at all of them + + align:start position:0% +should look at all of them + + + align:start position:0% +should look at all of them +and let's get to lecture nine + + align:start position:0% +and let's get to lecture nine + + + align:start position:0% +and let's get to lecture nine +is what we're doing today and this is + + align:start position:0% +is what we're doing today and this is + + + align:start position:0% +is what we're doing today and this is +risk sharing with production three main + + align:start position:0% +risk sharing with production three main + + + align:start position:0% +risk sharing with production three main +topics really risk and return in + + align:start position:0% +topics really risk and return in + + + align:start position:0% +topics really risk and return in +production and that part is continuation + + align:start position:0% +production and that part is continuation + + + align:start position:0% +production and that part is continuation +of some of the themes although we didn't + + align:start position:0% +of some of the themes although we didn't + + + align:start position:0% +of some of the themes although we didn't +really put all the pieces together we + + align:start position:0% +really put all the pieces together we + + + align:start position:0% +really put all the pieces together we +had production in the Dynamics lecture + + align:start position:0% +had production in the Dynamics lecture + + + align:start position:0% +had production in the Dynamics lecture +we had risk as in yields coming from + + align:start position:0% +we had risk as in yields coming from + + + align:start position:0% +we had risk as in yields coming from +land plots but we never talked about + + align:start position:0% +land plots but we never talked about + + + align:start position:0% +land plots but we never talked about +inputs into land plots and Associated + + align:start position:0% +inputs into land plots and Associated + + + align:start position:0% +inputs into land plots and Associated +outputs and so on so we'll put those two + + align:start position:0% +outputs and so on so we'll put those two + + + align:start position:0% +outputs and so on so we'll put those two +pieces together another feature of this + + align:start position:0% +pieces together another feature of this + + + align:start position:0% +pieces together another feature of this +lecture is that we're going to use data + + align:start position:0% +lecture is that we're going to use data + + + align:start position:0% +lecture is that we're going to use data +on production but also on consumption so + + align:start position:0% +on production but also on consumption so + + + align:start position:0% +on production but also on consumption so +both things will be there and this is + + align:start position:0% +both things will be there and this is + + + align:start position:0% +both things will be there and this is +illustrative of how powerful this risk + + align:start position:0% +illustrative of how powerful this risk + + + align:start position:0% +illustrative of how powerful this risk +sharing framework is it extends to more + + align:start position:0% +sharing framework is it extends to more + + + align:start position:0% +sharing framework is it extends to more +and more complicated situations we're + + align:start position:0% +and more complicated situations we're + + + align:start position:0% +and more complicated situations we're +able to do more and more with it and + + align:start position:0% +able to do more and more with it and + + + align:start position:0% +able to do more and more with it and +finally I have some words at the end + + align:start position:0% +finally I have some words at the end + + + align:start position:0% +finally I have some words at the end +about social networks and sharing risk + + align:start position:0% +about social networks and sharing risk + + + align:start position:0% +about social networks and sharing risk +and in particular an example that will + + align:start position:0% +and in particular an example that will + + + align:start position:0% +and in particular an example that will +remind you for better or worse of covid + + align:start position:0% +remind you for better or worse of covid + + + align:start position:0% +remind you for better or worse of covid +and what's going on or when people get + + align:start position:0% +and what's going on or when people get + + + align:start position:0% +and what's going on or when people get +sick with the economics okay so this + + align:start position:0% +sick with the economics okay so this + + + align:start position:0% +sick with the economics okay so this +first starred paper on the reading list + + align:start position:0% +first starred paper on the reading list + + + align:start position:0% +first starred paper on the reading list +with could its alert some pantalach it + + align:start position:0% +with could its alert some pantalach it + + + align:start position:0% +with could its alert some pantalach it +was Thai if you haven't guessed + + align:start position:0% +was Thai if you haven't guessed + + + align:start position:0% +was Thai if you haven't guessed +extensions of the theory project + + align:start position:0% +extensions of the theory project + + + align:start position:0% +extensions of the theory project +selection so we studied a model with + + align:start position:0% +selection so we studied a model with + + + align:start position:0% +selection so we studied a model with +risk and return in productive Assets in + + align:start position:0% +risk and return in productive Assets in + + + align:start position:0% +risk and return in productive Assets in +developing economies namely Thailand + + align:start position:0% +developing economies namely Thailand + + + align:start position:0% +developing economies namely Thailand +we're going to measure idiosyncratic and + + align:start position:0% +we're going to measure idiosyncratic and + + + align:start position:0% +we're going to measure idiosyncratic and +aggregate risk Premia those words + + align:start position:0% +aggregate risk Premia those words + + + align:start position:0% +aggregate risk Premia those words +probably don't make a whole lot of sense + + align:start position:0% +probably don't make a whole lot of sense + + + align:start position:0% +probably don't make a whole lot of sense +although we've been talking about + + align:start position:0% +although we've been talking about + + + align:start position:0% +although we've been talking about +related things just now with the risk + + align:start position:0% +related things just now with the risk + + + align:start position:0% +related things just now with the risk +sharing regression + + align:start position:0% +sharing regression + + + align:start position:0% +sharing regression +idiosyncratic being household specific + + align:start position:0% +idiosyncratic being household specific + + + align:start position:0% +idiosyncratic being household specific +income and aggregate being aggregate + + align:start position:0% +income and aggregate being aggregate + + + align:start position:0% +income and aggregate being aggregate +consumption and we're going to use we're + + align:start position:0% +consumption and we're going to use we're + + + align:start position:0% +consumption and we're going to use we're +going to be able to quantify those two + + align:start position:0% +going to be able to quantify those two + + + align:start position:0% +going to be able to quantify those two +different Premia and analyze what + + align:start position:0% +different Premia and analyze what + + + align:start position:0% +different Premia and analyze what +households are doing how exposed they + + align:start position:0% +households are doing how exposed they + + + align:start position:0% +households are doing how exposed they +are to risk and finally in principle one + + align:start position:0% +are to risk and finally in principle one + + + align:start position:0% +are to risk and finally in principle one +could take not just the straight out + + align:start position:0% +could take not just the straight out + + + align:start position:0% +could take not just the straight out +returns but risk-adjusted returns and + + align:start position:0% +returns but risk-adjusted returns and + + + align:start position:0% +returns but risk-adjusted returns and +look for patterns across households like + + align:start position:0% +look for patterns across households like + + + align:start position:0% +look for patterns across households like +whether poor households are more + + align:start position:0% +whether poor households are more + + + align:start position:0% +whether poor households are more +vulnerable or less vulnerable as + + align:start position:0% +vulnerable or less vulnerable as + + + align:start position:0% +vulnerable or less vulnerable as +education matter and so on so here's the + + align:start position:0% +education matter and so on so here's the + + + align:start position:0% +education matter and so on so here's the +model there are capital J households + + align:start position:0% +model there are capital J households + + + align:start position:0% +model there are capital J households +indexed by J Little J for an individual + + align:start position:0% +indexed by J Little J for an individual + + + align:start position:0% +indexed by J Little J for an individual +J is the number for the aggregate their + + align:start position:0% +J is the number for the aggregate their + + + align:start position:0% +J is the number for the aggregate their +eye production activities little I big I + + align:start position:0% +eye production activities little I big I + + + align:start position:0% +eye production activities little I big I +and you can think of those production + + align:start position:0% +and you can think of those production + + + align:start position:0% +and you can think of those production +activities as production sets or + + align:start position:0% +activities as production sets or + + + align:start position:0% +activities as production sets or +Production Technologies the inputs are + + align:start position:0% +Production Technologies the inputs are + + + align:start position:0% +Production Technologies the inputs are +capital and now say some words in a bit + + align:start position:0% +capital and now say some words in a bit + + + align:start position:0% +capital and now say some words in a bit +later about where labor and materials + + align:start position:0% +later about where labor and materials + + + align:start position:0% +later about where labor and materials +and seed and other things went but for + + align:start position:0% +and seed and other things went but for + + + align:start position:0% +and seed and other things went but for +now just think of being of there being a + + align:start position:0% +now just think of being of there being a + + + align:start position:0% +now just think of being of there being a +single input called capital and the + + align:start position:0% +single input called capital and the + + + align:start position:0% +single input called capital and the +outputs are in the same units of a + + align:start position:0% +outputs are in the same units of a + + + align:start position:0% +outputs are in the same units of a +single consumption good + + align:start position:0% +single consumption good + + + align:start position:0% +single consumption good +so we're going to be looking at a + + align:start position:0% +so we're going to be looking at a + + + align:start position:0% +so we're going to be looking at a +household running a portfolio of Assets + + align:start position:0% +household running a portfolio of Assets + + + align:start position:0% +household running a portfolio of Assets +Now actually the way you think about + + align:start position:0% +Now actually the way you think about + + + align:start position:0% +Now actually the way you think about +this in finance is you want to engage in + + align:start position:0% +this in finance is you want to engage in + + + align:start position:0% +this in finance is you want to engage in +a certain activity you require the + + align:start position:0% +a certain activity you require the + + + align:start position:0% +a certain activity you require the +assets necessary to do that activity and + + align:start position:0% +assets necessary to do that activity and + + + align:start position:0% +assets necessary to do that activity and +a household could be doing one or + + align:start position:0% +a household could be doing one or + + + align:start position:0% +a household could be doing one or +multiple activities this will generate a + + align:start position:0% +multiple activities this will generate a + + + align:start position:0% +multiple activities this will generate a +return so we want to know how well the + + align:start position:0% +return so we want to know how well the + + + align:start position:0% +return so we want to know how well the +project is doing and whether it was + + align:start position:0% +project is doing and whether it was + + + align:start position:0% +project is doing and whether it was +selected properly so you want to compare + + align:start position:0% +selected properly so you want to compare + + + align:start position:0% +selected properly so you want to compare +the rate of return to the best + + align:start position:0% +the rate of return to the best + + + align:start position:0% +the rate of return to the best +alternative use of funds + + align:start position:0% +alternative use of funds + + + align:start position:0% +alternative use of funds +except that here we're going to put risk + + align:start position:0% +except that here we're going to put risk + + + align:start position:0% +except that here we're going to put risk +in so it makes it much more interesting + + align:start position:0% +in so it makes it much more interesting + + + align:start position:0% +in so it makes it much more interesting +in particular these asset returns are + + align:start position:0% +in particular these asset returns are + + + align:start position:0% +in particular these asset returns are +stochastic and they can be correlated + + align:start position:0% +stochastic and they can be correlated + + + align:start position:0% +stochastic and they can be correlated +over activities and correlated over + + align:start position:0% +over activities and correlated over + + + align:start position:0% +over activities and correlated over +households + + align:start position:0% +households + + + align:start position:0% +households +so again you can think about the + + align:start position:0% +so again you can think about the + + + align:start position:0% +so again you can think about the +previous lecture with Village India + + align:start position:0% +previous lecture with Village India + + + align:start position:0% +previous lecture with Village India +although this happens to be Village + + align:start position:0% +although this happens to be Village + + + align:start position:0% +although this happens to be Village +Thailand that is different kinds of + + align:start position:0% +Thailand that is different kinds of + + + align:start position:0% +Thailand that is different kinds of +crops and different soils different + + align:start position:0% +crops and different soils different + + + align:start position:0% +crops and different soils different +income sources and so on so I mentioned + + align:start position:0% +income sources and so on so I mentioned + + + align:start position:0% +income sources and so on so I mentioned +early on in lecture one that we were + + align:start position:0% +early on in lecture one that we were + + + align:start position:0% +early on in lecture one that we were +going to go back and forth between uh + + align:start position:0% +going to go back and forth between uh + + + align:start position:0% +going to go back and forth between uh +actual real agrarian economies and + + align:start position:0% +actual real agrarian economies and + + + align:start position:0% +actual real agrarian economies and +Associated metaphors so we can talk + + align:start position:0% +Associated metaphors so we can talk + + + align:start position:0% +Associated metaphors so we can talk +about trees bearing fruit literally in + + align:start position:0% +about trees bearing fruit literally in + + + align:start position:0% +about trees bearing fruit literally in +the data but we can also talk about a + + align:start position:0% +the data but we can also talk about a + + + align:start position:0% +the data but we can also talk about a +tree as an asset in financial markets + + align:start position:0% +tree as an asset in financial markets + + + align:start position:0% +tree as an asset in financial markets +household sole assets and they pay + + align:start position:0% +household sole assets and they pay + + + align:start position:0% +household sole assets and they pay +dividends and there may be correlations + + align:start position:0% +dividends and there may be correlations + + + align:start position:0% +dividends and there may be correlations +in stock returns so exactly the same + + align:start position:0% +in stock returns so exactly the same + + + align:start position:0% +in stock returns so exactly the same +theory is being applied to two very + + align:start position:0% +theory is being applied to two very + + + align:start position:0% +theory is being applied to two very +different settings and in fact we're + + align:start position:0% +different settings and in fact we're + + + align:start position:0% +different settings and in fact we're +kind of reverse engineering in this + + align:start position:0% +kind of reverse engineering in this + + + align:start position:0% +kind of reverse engineering in this +paper we're taking measures of risk + + align:start position:0% +paper we're taking measures of risk + + + align:start position:0% +paper we're taking measures of risk +reduction and risk Premia that have been + + align:start position:0% +reduction and risk Premia that have been + + + align:start position:0% +reduction and risk Premia that have been +applied to stocks in the New York Stock + + align:start position:0% +applied to stocks in the New York Stock + + + align:start position:0% +applied to stocks in the New York Stock +Exchange and applying it to all these + + align:start position:0% +Exchange and applying it to all these + + + align:start position:0% +Exchange and applying it to all these +activities across various households in + + align:start position:0% +activities across various households in + + + align:start position:0% +activities across various households in +a in a typical Thai Village + + align:start position:0% +a in a typical Thai Village + + + align:start position:0% +a in a typical Thai Village +okay so a little bit more in notation we + + align:start position:0% +okay so a little bit more in notation we + + + align:start position:0% +okay so a little bit more in notation we +have F production function for activity + + align:start position:0% +have F production function for activity + + + align:start position:0% +have F production function for activity +I run by household J and it has as this + + align:start position:0% +I run by household J and it has as this + + + align:start position:0% +I run by household J and it has as this +single input the level at which it's + + align:start position:0% +single input the level at which it's + + + align:start position:0% +single input the level at which it's +capitalized the capital input inactivity + + align:start position:0% +capitalized the capital input inactivity + + + align:start position:0% +capitalized the capital input inactivity +I run by household J so we can sum over + + align:start position:0% +I run by household J so we can sum over + + + align:start position:0% +I run by household J so we can sum over +all activities in some overall + + align:start position:0% +all activities in some overall + + + align:start position:0% +all activities in some overall +households and get an aggregate + + align:start position:0% +households and get an aggregate + + + align:start position:0% +households and get an aggregate +production function so again early on in + + align:start position:0% +production function so again early on in + + + align:start position:0% +production function so again early on in +one of those lectures on production we + + align:start position:0% +one of those lectures on production we + + + align:start position:0% +one of those lectures on production we +talked about aggregating two example + + align:start position:0% +talked about aggregating two example + + + align:start position:0% +talked about aggregating two example +production sets into one so this is a + + align:start position:0% +production sets into one so this is a + + + align:start position:0% +production sets into one so this is a +version of that so the economy starts + + align:start position:0% +version of that so the economy starts + + + align:start position:0% +version of that so the economy starts +out with an aggregate amount of wealth + + align:start position:0% +out with an aggregate amount of wealth + + + align:start position:0% +out with an aggregate amount of wealth +which is coming from two sources + + align:start position:0% +which is coming from two sources + + + align:start position:0% +which is coming from two sources +one the trees and two the fruit now let + + align:start position:0% +one the trees and two the fruit now let + + + align:start position:0% +one the trees and two the fruit now let +me just say that as is standard in a lot + + align:start position:0% +me just say that as is standard in a lot + + + align:start position:0% +me just say that as is standard in a lot +not all but a lot of economic models + + align:start position:0% +not all but a lot of economic models + + + align:start position:0% +not all but a lot of economic models +we're gonna have we're going to call uh + + align:start position:0% +we're gonna have we're going to call uh + + + align:start position:0% +we're gonna have we're going to call uh +Putty Putty meaning that you take the + + align:start position:0% +Putty Putty meaning that you take the + + + align:start position:0% +Putty Putty meaning that you take the +putty in terms of very malleable + + align:start position:0% +putty in terms of very malleable + + + align:start position:0% +putty in terms of very malleable +consumption what could be consumption + + align:start position:0% +consumption what could be consumption + + + align:start position:0% +consumption what could be consumption +and invested into capital and then that + + align:start position:0% +and invested into capital and then that + + + align:start position:0% +and invested into capital and then that +yields a return you can certainly eat + + align:start position:0% +yields a return you can certainly eat + + + align:start position:0% +yields a return you can certainly eat +the fruit but you can also eat the tree + + align:start position:0% +the fruit but you can also eat the tree + + + align:start position:0% +the fruit but you can also eat the tree +so the Putty Putty part you know comes + + align:start position:0% +so the Putty Putty part you know comes + + + align:start position:0% +so the Putty Putty part you know comes +from undoing the tree of course in many + + align:start position:0% +from undoing the tree of course in many + + + align:start position:0% +from undoing the tree of course in many +actual situations you can't eat the + + align:start position:0% +actual situations you can't eat the + + + align:start position:0% +actual situations you can't eat the +machine but it's as if you could sell + + align:start position:0% +machine but it's as if you could sell + + + align:start position:0% +machine but it's as if you could sell +the machine and get the consumption + + align:start position:0% +the machine and get the consumption + + + align:start position:0% +the machine and get the consumption +equivalent if you wanted to eat all of + + align:start position:0% +equivalent if you wanted to eat all of + + + align:start position:0% +equivalent if you wanted to eat all of +it you could and you'll see that right + + align:start position:0% +it you could and you'll see that right + + + align:start position:0% +it you could and you'll see that right +now in the notation + + align:start position:0% +now in the notation + + + align:start position:0% +now in the notation +we're going to have quote unquote a + + align:start position:0% +we're going to have quote unquote a + + + align:start position:0% +we're going to have quote unquote a +social planner but of course you know + + align:start position:0% +social planner but of course you know + + + align:start position:0% +social planner but of course you know +now that's just means that we're going + + align:start position:0% +now that's just means that we're going + + + align:start position:0% +now that's just means that we're going +to have these programming problems for + + align:start position:0% +to have these programming problems for + + + align:start position:0% +to have these programming problems for +the determination of Pareto optimal + + align:start position:0% +the determination of Pareto optimal + + + align:start position:0% +the determination of Pareto optimal +allocation and we're going to act as if + + align:start position:0% +allocation and we're going to act as if + + + align:start position:0% +allocation and we're going to act as if +the planner is doing it but it's really + + align:start position:0% +the planner is doing it but it's really + + + align:start position:0% +the planner is doing it but it's really +a math problem that we can solve to go + + align:start position:0% +a math problem that we can solve to go + + + align:start position:0% +a math problem that we can solve to go +back and forth between solutions to the + + align:start position:0% +back and forth between solutions to the + + + align:start position:0% +back and forth between solutions to the +math problem + + align:start position:0% +math problem + + + align:start position:0% +math problem +and various Pareto optimal allocations + + align:start position:0% +and various Pareto optimal allocations + + + align:start position:0% +and various Pareto optimal allocations +so consumption of household J at a given + + align:start position:0% +so consumption of household J at a given + + + align:start position:0% +so consumption of household J at a given +moment say a year the sources of + + align:start position:0% +moment say a year the sources of + + + align:start position:0% +moment say a year the sources of +potential consumption would be the fruit + + align:start position:0% +potential consumption would be the fruit + + + align:start position:0% +potential consumption would be the fruit +how much activity I is yielding a fruit + + align:start position:0% +how much activity I is yielding a fruit + + + align:start position:0% +how much activity I is yielding a fruit +run by household J as a function of + + align:start position:0% +run by household J as a function of + + + align:start position:0% +run by household J as a function of +previously determined capitalization + + align:start position:0% +previously determined capitalization + + + align:start position:0% +previously determined capitalization +k i j we sum over all I and we have the + + align:start position:0% +k i j we sum over all I and we have the + + + align:start position:0% +k i j we sum over all I and we have the +tree itself which as I've said now would + + align:start position:0% +tree itself which as I've said now would + + + align:start position:0% +tree itself which as I've said now would +be potentially eaten but from these + + align:start position:0% +be potentially eaten but from these + + + align:start position:0% +be potentially eaten but from these +available resources we can subtract off + + align:start position:0% +available resources we can subtract off + + + align:start position:0% +available resources we can subtract off +the capitalization for Next Period Prime + + align:start position:0% +the capitalization for Next Period Prime + + + align:start position:0% +the capitalization for Next Period Prime +means tomorrow or next year and kij is + + align:start position:0% +means tomorrow or next year and kij is + + + align:start position:0% +means tomorrow or next year and kij is +the level of capital carried out from + + align:start position:0% +the level of capital carried out from + + + align:start position:0% +the level of capital carried out from +this year into next year so this is like + + align:start position:0% +this year into next year so this is like + + + align:start position:0% +this year into next year so this is like +storage in that Dynamic medieval village + + align:start position:0% +storage in that Dynamic medieval village + + + align:start position:0% +storage in that Dynamic medieval village +economy it's also like that's one + + align:start position:0% +economy it's also like that's one + + + align:start position:0% +economy it's also like that's one +activity seed planted in the ground is + + align:start position:0% +activity seed planted in the ground is + + + align:start position:0% +activity seed planted in the ground is +another type of activity this is a + + align:start position:0% +another type of activity this is a + + + align:start position:0% +another type of activity this is a +generalization + + align:start position:0% +generalization + + + align:start position:0% +generalization +and finally we have these transfers Tau + + align:start position:0% +and finally we have these transfers Tau + + + align:start position:0% +and finally we have these transfers Tau +these are going to be among other things + + align:start position:0% +these are going to be among other things + + + align:start position:0% +these are going to be among other things +key control variables of the so-called + + align:start position:0% +key control variables of the so-called + + + align:start position:0% +key control variables of the so-called +planner adding potentially to the + + align:start position:0% +planner adding potentially to the + + + align:start position:0% +planner adding potentially to the +resources of the household or if + + align:start position:0% +resources of the household or if + + + align:start position:0% +resources of the household or if +negative taking away + + align:start position:0% +negative taking away + + + align:start position:0% +negative taking away +so then we come to this programming + + align:start position:0% +so then we come to this programming + + + align:start position:0% +so then we come to this programming +problem for the determination of + + align:start position:0% +problem for the determination of + + + align:start position:0% +problem for the determination of +Pareto optimal allocations + + align:start position:0% +Pareto optimal allocations + + + align:start position:0% +Pareto optimal allocations +and despite some heavy looking notation + + align:start position:0% +and despite some heavy looking notation + + + align:start position:0% +and despite some heavy looking notation +you'll probably understand this pretty + + align:start position:0% +you'll probably understand this pretty + + + align:start position:0% +you'll probably understand this pretty +readily first of all here's the utility + + align:start position:0% +readily first of all here's the utility + + + align:start position:0% +readily first of all here's the utility +function of household J + + align:start position:0% +function of household J + + + align:start position:0% +function of household J +and all the slide does is stick into + + align:start position:0% +and all the slide does is stick into + + + align:start position:0% +and all the slide does is stick into +what would be consumption the + + align:start position:0% +what would be consumption the + + + align:start position:0% +what would be consumption the +consumption is defined at the bottom of + + align:start position:0% +consumption is defined at the bottom of + + + align:start position:0% +consumption is defined at the bottom of +the previous slide sort of resources + + align:start position:0% +the previous slide sort of resources + + + align:start position:0% +the previous slide sort of resources +available minus resources utilized for + + align:start position:0% +available minus resources utilized for + + + align:start position:0% +available minus resources utilized for +Next Period here plus the transfer these + + align:start position:0% +Next Period here plus the transfer these + + + align:start position:0% +Next Period here plus the transfer these +lambdas are the Pareto weights we're + + align:start position:0% +lambdas are the Pareto weights we're + + + align:start position:0% +lambdas are the Pareto weights we're +maximizing a Lambda weighted sum of + + align:start position:0% +maximizing a Lambda weighted sum of + + + align:start position:0% +maximizing a Lambda weighted sum of +utilities today + + align:start position:0% +utilities today + + + align:start position:0% +utilities today +and the control variables for the + + align:start position:0% +and the control variables for the + + + align:start position:0% +and the control variables for the +planter are these transfers as I've + + align:start position:0% +planter are these transfers as I've + + + align:start position:0% +planter are these transfers as I've +already said plus the level of + + align:start position:0% +already said plus the level of + + + align:start position:0% +already said plus the level of +capitalization of all the projects so + + align:start position:0% +capitalization of all the projects so + + + align:start position:0% +capitalization of all the projects so +we're trying to find an optimal + + align:start position:0% +we're trying to find an optimal + + + align:start position:0% +we're trying to find an optimal +allocation of capital as well as an + + align:start position:0% +allocation of capital as well as an + + + align:start position:0% +allocation of capital as well as an +optimal allocation of the transfers + + align:start position:0% +optimal allocation of the transfers + + + align:start position:0% +optimal allocation of the transfers +small apology the this apostrophe + + align:start position:0% +small apology the this apostrophe + + + align:start position:0% +small apology the this apostrophe +looking object shouldn't be there and on + + align:start position:0% +looking object shouldn't be there and on + + + align:start position:0% +looking object shouldn't be there and on +top of the towels it's not a prime + + align:start position:0% +top of the towels it's not a prime + + + align:start position:0% +top of the towels it's not a prime +because the transfers are decided today + + align:start position:0% +because the transfers are decided today + + + align:start position:0% +because the transfers are decided today +not next period but there's definitely a + + align:start position:0% +not next period but there's definitely a + + + align:start position:0% +not next period but there's definitely a +Prime on this Capital because the + + align:start position:0% +Prime on this Capital because the + + + align:start position:0% +Prime on this Capital because the +current state is already given the + + align:start position:0% +current state is already given the + + + align:start position:0% +current state is already given the +projects with their capitalizations the + + align:start position:0% +projects with their capitalizations the + + + align:start position:0% +projects with their capitalizations the +thing to be decided upon is how much + + align:start position:0% +thing to be decided upon is how much + + + align:start position:0% +thing to be decided upon is how much +Capital you want to invest in all the + + align:start position:0% +Capital you want to invest in all the + + + align:start position:0% +Capital you want to invest in all the +various possible projects for tomorrow + + align:start position:0% +various possible projects for tomorrow + + + align:start position:0% +various possible projects for tomorrow +um is it is it better to add a + + align:start position:0% +um is it is it better to add a + + + align:start position:0% +um is it is it better to add a +depreciation here because if you if you + + align:start position:0% +depreciation here because if you if you + + + align:start position:0% +depreciation here because if you if you +instead of a tree if you think of a + + align:start position:0% +instead of a tree if you think of a + + + align:start position:0% +instead of a tree if you think of a +machine + + align:start position:0% +machine + + + align:start position:0% +machine +yeah it will definitely depreciate yeah + + align:start position:0% +yeah it will definitely depreciate yeah + + + align:start position:0% +yeah it will definitely depreciate yeah +it's kind of loaded into this uh output + + align:start position:0% +it's kind of loaded into this uh output + + + align:start position:0% +it's kind of loaded into this uh output +so and you'll see this in the data you + + align:start position:0% +so and you'll see this in the data you + + + align:start position:0% +so and you'll see this in the data you +take net profits but you subtract off as + + align:start position:0% +take net profits but you subtract off as + + + align:start position:0% +take net profits but you subtract off as +an expense the depreciation but I mean + + align:start position:0% +an expense the depreciation but I mean + + + align:start position:0% +an expense the depreciation but I mean +it's true it's not there explicitly but + + align:start position:0% +it's true it's not there explicitly but + + + align:start position:0% +it's true it's not there explicitly but +that's where it is + + align:start position:0% +that's where it is + + + align:start position:0% +that's where it is +so yeah it should be and it is included + + align:start position:0% +so yeah it should be and it is included + + + align:start position:0% +so yeah it should be and it is included +okay okay now the other thing that makes + + align:start position:0% +okay okay now the other thing that makes + + + align:start position:0% +okay okay now the other thing that makes +this thing complicated but again you're + + align:start position:0% +this thing complicated but again you're + + + align:start position:0% +this thing complicated but again you're +already tooled up to get this right away + + align:start position:0% +already tooled up to get this right away + + + align:start position:0% +already tooled up to get this right away +these are these value functions + + align:start position:0% +these are these value functions + + + align:start position:0% +these are these value functions +so what what is the state of the world + + align:start position:0% +so what what is the state of the world + + + align:start position:0% +so what what is the state of the world +today it's total wealth that's available + + align:start position:0% +today it's total wealth that's available + + + align:start position:0% +today it's total wealth that's available +at the bottom of the slide summing + + align:start position:0% +at the bottom of the slide summing + + + align:start position:0% +at the bottom of the slide summing +overall activities in households all + + align:start position:0% +overall activities in households all + + + align:start position:0% +overall activities in households all +fruit and all trees this Capital Lambda + + align:start position:0% +fruit and all trees this Capital Lambda + + + align:start position:0% +fruit and all trees this Capital Lambda +is just the individual Pareto weights + + align:start position:0% +is just the individual Pareto weights + + + align:start position:0% +is just the individual Pareto weights +and they're fixed for all time and then + + align:start position:0% +and they're fixed for all time and then + + + align:start position:0% +and they're fixed for all time and then +you decide on these control variables + + align:start position:0% +you decide on these control variables + + + align:start position:0% +you decide on these control variables +how much to eat and how much to save in + + align:start position:0% +how much to eat and how much to save in + + + align:start position:0% +how much to eat and how much to save in +the various Technologies that's going to + + align:start position:0% +the various Technologies that's going to + + + align:start position:0% +the various Technologies that's going to +deliver a state for tomorrow which is + + align:start position:0% +deliver a state for tomorrow which is + + + align:start position:0% +deliver a state for tomorrow which is +wealth tomorrow W it would be W Prime + + align:start position:0% +wealth tomorrow W it would be W Prime + + + align:start position:0% +wealth tomorrow W it would be W Prime +just like w is this period W Prime would + + align:start position:0% +just like w is this period W Prime would + + + align:start position:0% +just like w is this period W Prime would +be for Next Period and you would have a + + align:start position:0% +be for Next Period and you would have a + + + align:start position:0% +be for Next Period and you would have a +Prime on all of these objects you'd have + + align:start position:0% +Prime on all of these objects you'd have + + + align:start position:0% +Prime on all of these objects you'd have +the fruit in the trees Next Period at + + align:start position:0% +the fruit in the trees Next Period at + + + align:start position:0% +the fruit in the trees Next Period at +Prime that's the W Prime this value + + align:start position:0% +Prime that's the W Prime this value + + + align:start position:0% +Prime that's the W Prime this value +function is as if they lived in a + + align:start position:0% +function is as if they lived in a + + + align:start position:0% +function is as if they lived in a +infinite Horizon economy they're + + align:start position:0% +infinite Horizon economy they're + + + align:start position:0% +infinite Horizon economy they're +discounting Next Period by this fee + + align:start position:0% +discounting Next Period by this fee + + + align:start position:0% +discounting Next Period by this fee +usually we use beta but beta in this + + align:start position:0% +usually we use beta but beta in this + + + align:start position:0% +usually we use beta but beta in this +lecture is reserved for something adults + + align:start position:0% +lecture is reserved for something adults + + + align:start position:0% +lecture is reserved for something adults +like a regression coefficient so Phi is + + align:start position:0% +like a regression coefficient so Phi is + + + align:start position:0% +like a regression coefficient so Phi is +the common discount rate across all the + + align:start position:0% +the common discount rate across all the + + + align:start position:0% +the common discount rate across all the +households and you remember how we got + + align:start position:0% +households and you remember how we got + + + align:start position:0% +households and you remember how we got +these V's right we had a slide at the + + align:start position:0% +these V's right we had a slide at the + + + align:start position:0% +these V's right we had a slide at the +end of one of the at the dynamic lecture + + align:start position:0% +end of one of the at the dynamic lecture + + + align:start position:0% +end of one of the at the dynamic lecture +you know act like it's a finite period + + align:start position:0% +you know act like it's a finite period + + + align:start position:0% +you know act like it's a finite period +solve for the optimum which would be you + + align:start position:0% +solve for the optimum which would be you + + + align:start position:0% +solve for the optimum which would be you +know don't fund everything eat + + align:start position:0% +know don't fund everything eat + + + align:start position:0% +know don't fund everything eat +everything in sight and then go to the + + align:start position:0% +everything in sight and then go to the + + + align:start position:0% +everything in sight and then go to the +next to last period and third to last + + align:start position:0% +next to last period and third to last + + + align:start position:0% +next to last period and third to last +period and then keep iterating as far + + align:start position:0% +period and then keep iterating as far + + + align:start position:0% +period and then keep iterating as far +back into the present as possible and + + align:start position:0% +back into the present as possible and + + + align:start position:0% +back into the present as possible and +this value function which would have a t + + align:start position:0% +this value function which would have a t + + + align:start position:0% +this value function which would have a t +on it for the length of the Horizon will + + align:start position:0% +on it for the length of the Horizon will + + + align:start position:0% +on it for the length of the Horizon will +go to something stable as if we had + + align:start position:0% +go to something stable as if we had + + + align:start position:0% +go to something stable as if we had +solved the infinite Horizon problem so + + align:start position:0% +solved the infinite Horizon problem so + + + align:start position:0% +solved the infinite Horizon problem so +that's all loaded up in here too + + align:start position:0% +that's all loaded up in here too + + + align:start position:0% +that's all loaded up in here too +questions about this slide + + align:start position:0% +questions about this slide + + + align:start position:0% +questions about this slide +oh one last thing you can't put negative + + align:start position:0% +oh one last thing you can't put negative + + + align:start position:0% +oh one last thing you can't put negative +Capital into the ground I mean Capital + + align:start position:0% +Capital into the ground I mean Capital + + + align:start position:0% +Capital into the ground I mean Capital +could be zero but in which case you're + + align:start position:0% +could be zero but in which case you're + + + align:start position:0% +could be zero but in which case you're +not doing that activity or it's positive + + align:start position:0% +not doing that activity or it's positive + + + align:start position:0% +not doing that activity or it's positive +in which case you are doing the activity + + align:start position:0% +in which case you are doing the activity + + + align:start position:0% +in which case you are doing the activity +this is true over all projects I and all + + align:start position:0% +this is true over all projects I and all + + + align:start position:0% +this is true over all projects I and all +households J + + align:start position:0% +households J + + + align:start position:0% +households J +you can set that thing up as a + + align:start position:0% +you can set that thing up as a + + + align:start position:0% +you can set that thing up as a +lagrangian with the Shadow prices and + + align:start position:0% +lagrangian with the Shadow prices and + + + align:start position:0% +lagrangian with the Shadow prices and +solve and you'll get kind of a familiar + + align:start position:0% +solve and you'll get kind of a familiar + + + align:start position:0% +solve and you'll get kind of a familiar +condition if you differentiate with + + align:start position:0% +condition if you differentiate with + + + align:start position:0% +condition if you differentiate with +respect to consumptions or the transfers + + align:start position:0% +respect to consumptions or the transfers + + + align:start position:0% +respect to consumptions or the transfers +for that matter uh you will get that + + align:start position:0% +for that matter uh you will get that + + + align:start position:0% +for that matter uh you will get that +these Lambda weighted margin utilities + + align:start position:0% +these Lambda weighted margin utilities + + + align:start position:0% +these Lambda weighted margin utilities +should be the same overall households + + align:start position:0% +should be the same overall households + + + align:start position:0% +should be the same overall households +and equal to a common LaGrange + + align:start position:0% +and equal to a common LaGrange + + + align:start position:0% +and equal to a common LaGrange +multiplier on the current resource + + align:start position:0% +multiplier on the current resource + + + align:start position:0% +multiplier on the current resource +constraint mu so you've actually seen + + align:start position:0% +constraint mu so you've actually seen + + + align:start position:0% +constraint mu so you've actually seen +this before + + align:start position:0% +this before + + + align:start position:0% +this before +it's exactly equal to what we had before + + align:start position:0% +it's exactly equal to what we had before + + + align:start position:0% +it's exactly equal to what we had before +in Village India without consideration + + align:start position:0% +in Village India without consideration + + + align:start position:0% +in Village India without consideration +of production + + align:start position:0% +of production + + + align:start position:0% +of production +but we're going to get something else + + align:start position:0% +but we're going to get something else + + + align:start position:0% +but we're going to get something else +namely when we look at the control + + align:start position:0% +namely when we look at the control + + + align:start position:0% +namely when we look at the control +variable the capital control variables + + align:start position:0% +variable the capital control variables + + + align:start position:0% +variable the capital control variables +we're going to get something that links + + align:start position:0% +we're going to get something that links + + + align:start position:0% +we're going to get something that links +marginal utility today to effectively to + + align:start position:0% +marginal utility today to effectively to + + + align:start position:0% +marginal utility today to effectively to +marginal utility Next Period and that is + + align:start position:0% +marginal utility Next Period and that is + + + align:start position:0% +marginal utility Next Period and that is +that the Lambda weighted margin utility + + align:start position:0% +that the Lambda weighted margin utility + + + align:start position:0% +that the Lambda weighted margin utility +of consumption today for household J If + + align:start position:0% +of consumption today for household J If + + + align:start position:0% +of consumption today for household J If +This Were said equal should be equal to + + align:start position:0% +This Were said equal should be equal to + + + align:start position:0% +This Were said equal should be equal to +the Future margin utility well if you + + align:start position:0% +the Future margin utility well if you + + + align:start position:0% +the Future margin utility well if you +take a unit of resource today + + align:start position:0% +take a unit of resource today + + + align:start position:0% +take a unit of resource today +infinitesimally small and instead of + + align:start position:0% +infinitesimally small and instead of + + + align:start position:0% +infinitesimally small and instead of +eating it you invest it what you'll get + + align:start position:0% +eating it you invest it what you'll get + + + align:start position:0% +eating it you invest it what you'll get +tomorrow would be the derivative of the + + align:start position:0% +tomorrow would be the derivative of the + + + align:start position:0% +tomorrow would be the derivative of the +production function of that investment + + align:start position:0% +production function of that investment + + + align:start position:0% +production function of that investment +plus you get the tree back that one unit + + align:start position:0% +plus you get the tree back that one unit + + + align:start position:0% +plus you get the tree back that one unit +back and that return stream is going to + + align:start position:0% +back and that return stream is going to + + + align:start position:0% +back and that return stream is going to +be evaluated at the margin utility of + + align:start position:0% +be evaluated at the margin utility of + + + align:start position:0% +be evaluated at the margin utility of +wealth which is the derivative of this + + align:start position:0% +wealth which is the derivative of this + + + align:start position:0% +wealth which is the derivative of this +value function at tomorrow's wealth so + + align:start position:0% +value function at tomorrow's wealth so + + + align:start position:0% +value function at tomorrow's wealth so +again we're just taking a derivative of + + align:start position:0% +again we're just taking a derivative of + + + align:start position:0% +again we're just taking a derivative of +this right hand side term + + align:start position:0% +this right hand side term + + + align:start position:0% +this right hand side term +questions so it's written as a weak + + align:start position:0% +questions so it's written as a weak + + + align:start position:0% +questions so it's written as a weak +inequality it could be less than zero if + + align:start position:0% +inequality it could be less than zero if + + + align:start position:0% +inequality it could be less than zero if +it's less than zero let's take the + + align:start position:0% +it's less than zero let's take the + + + align:start position:0% +it's less than zero let's take the +margin utility of consumption today + + align:start position:0% +margin utility of consumption today + + + align:start position:0% +margin utility of consumption today +which is minus on and on the left hand + + align:start position:0% +which is minus on and on the left hand + + + align:start position:0% +which is minus on and on the left hand +side and put it on the right hand side + + align:start position:0% +side and put it on the right hand side + + + align:start position:0% +side and put it on the right hand side +and that would say the weighted margin + + align:start position:0% +and that would say the weighted margin + + + align:start position:0% +and that would say the weighted margin +utility of consumption today is strictly + + align:start position:0% +utility of consumption today is strictly + + + align:start position:0% +utility of consumption today is strictly +greater than the margin utility you + + align:start position:0% +greater than the margin utility you + + + align:start position:0% +greater than the margin utility you +would get tomorrow so they're going to + + align:start position:0% +would get tomorrow so they're going to + + + align:start position:0% +would get tomorrow so they're going to +hit a corner they would like actually + + align:start position:0% +hit a corner they would like actually + + + align:start position:0% +hit a corner they would like actually +the capital level to go negative because + + align:start position:0% +the capital level to go negative because + + + align:start position:0% +the capital level to go negative because +they're kind of desperate to eat today + + align:start position:0% +they're kind of desperate to eat today + + + align:start position:0% +they're kind of desperate to eat today +the marginal utility return today is + + align:start position:0% +the marginal utility return today is + + + align:start position:0% +the marginal utility return today is +higher than it will be next period but + + align:start position:0% +higher than it will be next period but + + + align:start position:0% +higher than it will be next period but +of course we're not allowing them to go + + align:start position:0% +of course we're not allowing them to go + + + align:start position:0% +of course we're not allowing them to go +negative so hence the inequality if if + + align:start position:0% +negative so hence the inequality if if + + + align:start position:0% +negative so hence the inequality if if +to remind you in other contexts we write + + align:start position:0% +to remind you in other contexts we write + + + align:start position:0% +to remind you in other contexts we write +out the full lagrangian program we put + + align:start position:0% +out the full lagrangian program we put + + + align:start position:0% +out the full lagrangian program we put +an extra LaGrange multiplier on these + + align:start position:0% +an extra LaGrange multiplier on these + + + align:start position:0% +an extra LaGrange multiplier on these +non-negativity constraints then this + + align:start position:0% +non-negativity constraints then this + + + align:start position:0% +non-negativity constraints then this +whole thing would be at an equality but + + align:start position:0% +whole thing would be at an equality but + + + align:start position:0% +whole thing would be at an equality but +it would have as well the potentially + + align:start position:0% +it would have as well the potentially + + + align:start position:0% +it would have as well the potentially +positive LaGrange multiplier + + align:start position:0% +positive LaGrange multiplier + + + align:start position:0% +positive LaGrange multiplier +anyway the conclusion is not all + + align:start position:0% +anyway the conclusion is not all + + + align:start position:0% +anyway the conclusion is not all +activities need to be funded you might + + align:start position:0% +activities need to be funded you might + + + align:start position:0% +activities need to be funded you might +actually want to unfund them and draw + + align:start position:0% +actually want to unfund them and draw + + + align:start position:0% +actually want to unfund them and draw +resources out of them that aren't there + + align:start position:0% +resources out of them that aren't there + + + align:start position:0% +resources out of them that aren't there +you can't do that so you set them equal + + align:start position:0% +you can't do that so you set them equal + + + align:start position:0% +you can't do that so you set them equal +to zero others get funded at a positive + + align:start position:0% +to zero others get funded at a positive + + + align:start position:0% +to zero others get funded at a positive +level we will be focusing a lot on the + + align:start position:0% +level we will be focusing a lot on the + + + align:start position:0% +level we will be focusing a lot on the +set of activities over households for + + align:start position:0% +set of activities over households for + + + align:start position:0% +set of activities over households for +which this is equal to zero and those + + align:start position:0% +which this is equal to zero and those + + + align:start position:0% +which this is equal to zero and those +are funded projects okay so it looks + + align:start position:0% +are funded projects okay so it looks + + + align:start position:0% +are funded projects okay so it looks +like this is entirely closed economy but + + align:start position:0% +like this is entirely closed economy but + + + align:start position:0% +like this is entirely closed economy but +as I said these techniques generalize so + + align:start position:0% +as I said these techniques generalize so + + + align:start position:0% +as I said these techniques generalize so +we can think of a village as a small + + align:start position:0% +we can think of a village as a small + + + align:start position:0% +we can think of a village as a small +open economy and maybe they can go to an + + align:start position:0% +open economy and maybe they can go to an + + + align:start position:0% +open economy and maybe they can go to an +outside bank and borrow money in which + + align:start position:0% +outside bank and borrow money in which + + + align:start position:0% +outside bank and borrow money in which +case we'd have to change the wealth + + align:start position:0% +case we'd have to change the wealth + + + align:start position:0% +case we'd have to change the wealth +variable to subtract off the principal + + align:start position:0% +variable to subtract off the principal + + + align:start position:0% +variable to subtract off the principal +and interest that's coming due today but + + align:start position:0% +and interest that's coming due today but + + + align:start position:0% +and interest that's coming due today but +add in the debt that they enter into + + align:start position:0% +add in the debt that they enter into + + + align:start position:0% +add in the debt that they enter into +today that will come due the next period + + align:start position:0% +today that will come due the next period + + + align:start position:0% +today that will come due the next period +nothing changes these first order + + align:start position:0% +nothing changes these first order + + + align:start position:0% +nothing changes these first order +conditions don't change oh it's good for + + align:start position:0% +conditions don't change oh it's good for + + + align:start position:0% +conditions don't change oh it's good for +them in terms of smoothing if the + + align:start position:0% +them in terms of smoothing if the + + + align:start position:0% +them in terms of smoothing if the +village wealth is low The Village as a + + align:start position:0% +village wealth is low The Village as a + + + align:start position:0% +village wealth is low The Village as a +whole might want to borrow that's fine + + align:start position:0% +whole might want to borrow that's fine + + + align:start position:0% +whole might want to borrow that's fine +so the quantitative solution can change + + align:start position:0% +so the quantitative solution can change + + + align:start position:0% +so the quantitative solution can change +but our characterization in terms of + + align:start position:0% +but our characterization in terms of + + + align:start position:0% +but our characterization in terms of +these first order conditions will not + + align:start position:0% +these first order conditions will not + + + align:start position:0% +these first order conditions will not +change but we do not need to assume a + + align:start position:0% +change but we do not need to assume a + + + align:start position:0% +change but we do not need to assume a +closed economy all right so what the + + align:start position:0% +closed economy all right so what the + + + align:start position:0% +closed economy all right so what the +heck is this well + + align:start position:0% +heck is this well + + + align:start position:0% +heck is this well +this mu is the land awaited marketing + + align:start position:0% +this mu is the land awaited marketing + + + align:start position:0% +this mu is the land awaited marketing +utility I substituted that into this + + align:start position:0% +utility I substituted that into this + + + align:start position:0% +utility I substituted that into this +left-hand side of the second expression + + align:start position:0% +left-hand side of the second expression + + + align:start position:0% +left-hand side of the second expression +set it equal to zero + + align:start position:0% +set it equal to zero + + + align:start position:0% +set it equal to zero +and then you've got two terms dividing + + align:start position:0% +and then you've got two terms dividing + + + align:start position:0% +and then you've got two terms dividing +through by this + + align:start position:0% +through by this + + + align:start position:0% +through by this +you would set everything equal to one so + + align:start position:0% +you would set everything equal to one so + + + align:start position:0% +you would set everything equal to one so +it's actually easier to look at the + + align:start position:0% +it's actually easier to look at the + + + align:start position:0% +it's actually easier to look at the +algebra than it is to to say it in words + + align:start position:0% +algebra than it is to to say it in words + + + align:start position:0% +algebra than it is to to say it in words +we take mu here and divide this term by + + align:start position:0% +we take mu here and divide this term by + + + align:start position:0% +we take mu here and divide this term by +mu which makes it equal to Unity and the + + align:start position:0% +mu which makes it equal to Unity and the + + + align:start position:0% +mu which makes it equal to Unity and the +second term by mu which is what is being + + align:start position:0% +second term by mu which is what is being + + + align:start position:0% +second term by mu which is what is being +displayed here + + align:start position:0% +displayed here + + + align:start position:0% +displayed here +and then the rest is algebra although + + align:start position:0% +and then the rest is algebra although + + + align:start position:0% +and then the rest is algebra although +it's kind of revealing that we can take + + align:start position:0% +it's kind of revealing that we can take + + + align:start position:0% +it's kind of revealing that we can take +this expectation operator outside the + + align:start position:0% +this expectation operator outside the + + + align:start position:0% +this expectation operator outside the +whole expression because these returns + + align:start position:0% +whole expression because these returns + + + align:start position:0% +whole expression because these returns +are random I'm not sure I've been + + align:start position:0% +are random I'm not sure I've been + + + align:start position:0% +are random I'm not sure I've been +emphasizing that enough + + align:start position:0% +emphasizing that enough + + + align:start position:0% +emphasizing that enough +it looked like constants because you + + align:start position:0% +it looked like constants because you + + + align:start position:0% +it looked like constants because you +just have the level of capital but the + + align:start position:0% +just have the level of capital but the + + + align:start position:0% +just have the level of capital but the +the return on a unit of capital is + + align:start position:0% +the return on a unit of capital is + + + align:start position:0% +the return on a unit of capital is +random where did that first start to + + align:start position:0% +random where did that first start to + + + align:start position:0% +random where did that first start to +happen + + align:start position:0% +happen + + + align:start position:0% +happen +I should have said it right here when we + + align:start position:0% +I should have said it right here when we + + + align:start position:0% +I should have said it right here when we +had that expectation operator so anyway + + align:start position:0% +had that expectation operator so anyway + + + align:start position:0% +had that expectation operator so anyway +bring the expectation operator out in + + align:start position:0% +bring the expectation operator out in + + + align:start position:0% +bring the expectation operator out in +front of everything and then adopt some + + align:start position:0% +front of everything and then adopt some + + + align:start position:0% +front of everything and then adopt some +very cryptic notation M actually M Prime + + align:start position:0% +very cryptic notation M actually M Prime + + + align:start position:0% +very cryptic notation M actually M Prime +for for this term which is essentially + + align:start position:0% +for for this term which is essentially + + + align:start position:0% +for for this term which is essentially +the discounted LaGrange multiplier Next + + align:start position:0% +the discounted LaGrange multiplier Next + + + align:start position:0% +the discounted LaGrange multiplier Next +Period divided by the LaGrange + + align:start position:0% +Period divided by the LaGrange + + + align:start position:0% +Period divided by the LaGrange +multiplier today + + align:start position:0% +multiplier today + + + align:start position:0% +multiplier today +so that that's like a discount Factor + + align:start position:0% +so that that's like a discount Factor + + + align:start position:0% +so that that's like a discount Factor +call it m Prime and this r capital r is + + align:start position:0% +call it m Prime and this r capital r is + + + align:start position:0% +call it m Prime and this r capital r is +the total return on the project being + + align:start position:0% +the total return on the project being + + + align:start position:0% +the total return on the project being +run the activity I run by household J + + align:start position:0% +run the activity I run by household J + + + align:start position:0% +run the activity I run by household J +the return you get the tree back plus + + align:start position:0% +the return you get the tree back plus + + + align:start position:0% +the return you get the tree back plus +the fruit and this this is a prime here + + align:start position:0% +the fruit and this this is a prime here + + + align:start position:0% +the fruit and this this is a prime here +it's the marginal return obviously + + align:start position:0% +it's the marginal return obviously + + + align:start position:0% +it's the marginal return obviously +because when we looked at the first + + align:start position:0% +because when we looked at the first + + + align:start position:0% +because when we looked at the first +order condition we were varying the + + align:start position:0% +order condition we were varying the + + + align:start position:0% +order condition we were varying the +level of capital so we picked up a + + align:start position:0% +level of capital so we picked up a + + + align:start position:0% +level of capital so we picked up a +derivative in the production function so + + align:start position:0% +derivative in the production function so + + + align:start position:0% +derivative in the production function so +this is just notation but it's very + + align:start position:0% +this is just notation but it's very + + + align:start position:0% +this is just notation but it's very +convenient notation + + align:start position:0% +convenient notation + + + align:start position:0% +convenient notation +so it's saying that for all activities I + + align:start position:0% +so it's saying that for all activities I + + + align:start position:0% +so it's saying that for all activities I +run by households J this product the + + align:start position:0% +run by households J this product the + + + align:start position:0% +run by households J this product the +this expected product is equal to one + + align:start position:0% +this expected product is equal to one + + + align:start position:0% +this expected product is equal to one +furthermore looking at that expected + + align:start position:0% +furthermore looking at that expected + + + align:start position:0% +furthermore looking at that expected +product there's a result in statistics + + align:start position:0% +product there's a result in statistics + + + align:start position:0% +product there's a result in statistics +that we didn't put into the lecture on + + align:start position:0% +that we didn't put into the lecture on + + + align:start position:0% +that we didn't put into the lecture on +uncertainty but it's easy enough to + + align:start position:0% +uncertainty but it's easy enough to + + + align:start position:0% +uncertainty but it's easy enough to +state which is expectation of two random + + align:start position:0% +state which is expectation of two random + + + align:start position:0% +state which is expectation of two random +variables is equal to the product of the + + align:start position:0% +variables is equal to the product of the + + + align:start position:0% +variables is equal to the product of the +expectations adjusted by the covariance + + align:start position:0% +expectations adjusted by the covariance + + + align:start position:0% +expectations adjusted by the covariance +of the two variables if the covariance + + align:start position:0% +of the two variables if the covariance + + + align:start position:0% +of the two variables if the covariance +is zero then these variants these + + align:start position:0% +is zero then these variants these + + + align:start position:0% +is zero then these variants these +individual variables are independent and + + align:start position:0% +individual variables are independent and + + + align:start position:0% +individual variables are independent and +it's just a product of the expectations + + align:start position:0% +it's just a product of the expectations + + + align:start position:0% +it's just a product of the expectations +but the covariance is an easy way to + + align:start position:0% +but the covariance is an easy way to + + + align:start position:0% +but the covariance is an easy way to +adjust if they're not independent so now + + align:start position:0% +adjust if they're not independent so now + + + align:start position:0% +adjust if they're not independent so now +we just substitute in that formula in + + align:start position:0% +we just substitute in that formula in + + + align:start position:0% +we just substitute in that formula in +the previous slide which had this + + align:start position:0% +the previous slide which had this + + + align:start position:0% +the previous slide which had this +expression on the left we now substitute + + align:start position:0% +expression on the left we now substitute + + + align:start position:0% +expression on the left we now substitute +in the expression on the right and + + align:start position:0% +in the expression on the right and + + + align:start position:0% +in the expression on the right and +manipulate by dividing through this + + align:start position:0% +manipulate by dividing through this + + + align:start position:0% +manipulate by dividing through this +expectation of M Prime and we get this + + align:start position:0% +expectation of M Prime and we get this + + + align:start position:0% +expectation of M Prime and we get this +object here so the expected return on + + align:start position:0% +object here so the expected return on + + + align:start position:0% +object here so the expected return on +activity I run by household J + + align:start position:0% +activity I run by household J + + + align:start position:0% +activity I run by household J +expect to return next period as an + + align:start position:0% +expect to return next period as an + + + align:start position:0% +expect to return next period as an +Intercept in some kind of product term + + align:start position:0% +Intercept in some kind of product term + + + align:start position:0% +Intercept in some kind of product term +and I'm about to give you an + + align:start position:0% +and I'm about to give you an + + + align:start position:0% +and I'm about to give you an +interpretation of what these are and in + + align:start position:0% +interpretation of what these are and in + + + align:start position:0% +interpretation of what these are and in +some respects this beta is going to be a + + align:start position:0% +some respects this beta is going to be a + + + align:start position:0% +some respects this beta is going to be a +regression coefficient and the Lambda is + + align:start position:0% +regression coefficient and the Lambda is + + + align:start position:0% +regression coefficient and the Lambda is +going to be a measure of social risk + + align:start position:0% +going to be a measure of social risk + + + align:start position:0% +going to be a measure of social risk +in particular finally + + align:start position:0% +in particular finally + + + align:start position:0% +in particular finally +if we imagine those production functions + + align:start position:0% +if we imagine those production functions + + + align:start position:0% +if we imagine those production functions +are linear + + align:start position:0% +are linear + + + align:start position:0% +are linear +then the return on activity I run by + + align:start position:0% +then the return on activity I run by + + + align:start position:0% +then the return on activity I run by +household J is linear in the capital + + align:start position:0% +household J is linear in the capital + + + align:start position:0% +household J is linear in the capital +constant returns to scale however as I + + align:start position:0% +constant returns to scale however as I + + + align:start position:0% +constant returns to scale however as I +have been trying to say this return this + + align:start position:0% +have been trying to say this return this + + + align:start position:0% +have been trying to say this return this +little r thing is a random variable + + align:start position:0% +little r thing is a random variable + + + align:start position:0% +little r thing is a random variable +anyway the marginal return is that + + align:start position:0% +anyway the marginal return is that + + + align:start position:0% +anyway the marginal return is that +little r so also is the average return + + align:start position:0% +little r so also is the average return + + + align:start position:0% +little r so also is the average return +for that matter and we can talk about + + align:start position:0% +for that matter and we can talk about + + + align:start position:0% +for that matter and we can talk about +the growth rate of return equal one plus + + align:start position:0% +the growth rate of return equal one plus + + + align:start position:0% +the growth rate of return equal one plus +the net rate of return as a definition + + align:start position:0% +the net rate of return as a definition + + + align:start position:0% +the net rate of return as a definition +of capital r just so you might feel a + + align:start position:0% +of capital r just so you might feel a + + + align:start position:0% +of capital r just so you might feel a +bit more comfortable if we have a + + align:start position:0% +bit more comfortable if we have a + + + align:start position:0% +bit more comfortable if we have a +constant returns to scale production + + align:start position:0% +constant returns to scale production + + + align:start position:0% +constant returns to scale production +function actually finally modeling other + + align:start position:0% +function actually finally modeling other + + + align:start position:0% +function actually finally modeling other +inputs like labor and materials and so + + align:start position:0% +inputs like labor and materials and so + + + align:start position:0% +inputs like labor and materials and so +on if you optimize that and put the + + align:start position:0% +on if you optimize that and put the + + + align:start position:0% +on if you optimize that and put the +optimized inputs back into the function + + align:start position:0% +optimized inputs back into the function + + + align:start position:0% +optimized inputs back into the function +you would get this derived function + + align:start position:0% +you would get this derived function + + + align:start position:0% +you would get this derived function +which is linear in the Capital stock so + + align:start position:0% +which is linear in the Capital stock so + + + align:start position:0% +which is linear in the Capital stock so +that's where it's coming from but I + + align:start position:0% +that's where it's coming from but I + + + align:start position:0% +that's where it's coming from but I +didn't give you that algebra secondly + + align:start position:0% +didn't give you that algebra secondly + + + align:start position:0% +didn't give you that algebra secondly +what about preferences let's let the + + align:start position:0% +what about preferences let's let the + + + align:start position:0% +what about preferences let's let the +value function be quadratic so you've + + align:start position:0% +value function be quadratic so you've + + + align:start position:0% +value function be quadratic so you've +seen these before W star is kind of a + + align:start position:0% +seen these before W star is kind of a + + + align:start position:0% +seen these before W star is kind of a +bliss point and W less than W star so + + align:start position:0% +bliss point and W less than W star so + + + align:start position:0% +bliss point and W less than W star so +that the margin utility of wealth is + + align:start position:0% +that the margin utility of wealth is + + + align:start position:0% +that the margin utility of wealth is +always strictly positive so if we go + + align:start position:0% +always strictly positive so if we go + + + align:start position:0% +always strictly positive so if we go +back to this guy here and start + + align:start position:0% +back to this guy here and start + + + align:start position:0% +back to this guy here and start +substituting in what we know about + + align:start position:0% +substituting in what we know about + + + align:start position:0% +substituting in what we know about +assumed about the production function + + align:start position:0% +assumed about the production function + + + align:start position:0% +assumed about the production function +and utility function now we're actually + + align:start position:0% +and utility function now we're actually + + + align:start position:0% +and utility function now we're actually +going to get an expression which says + + align:start position:0% +going to get an expression which says + + + align:start position:0% +going to get an expression which says +the average or expected return on + + align:start position:0% +the average or expected return on + + + align:start position:0% +the average or expected return on +household J's activities less the + + align:start position:0% +household J's activities less the + + + align:start position:0% +household J's activities less the +risk-free rate is equal to Beta J for + + align:start position:0% +risk-free rate is equal to Beta J for + + + align:start position:0% +risk-free rate is equal to Beta J for +household J times the expected return in + + align:start position:0% +household J times the expected return in + + + align:start position:0% +household J times the expected return in +the whole village minus the risk-free + + align:start position:0% +the whole village minus the risk-free + + + align:start position:0% +the whole village minus the risk-free +rate in fact you can put this R Prime F + + align:start position:0% +rate in fact you can put this R Prime F + + + align:start position:0% +rate in fact you can put this R Prime F +the risk-free rate on the right hand + + align:start position:0% +the risk-free rate on the right hand + + + align:start position:0% +the risk-free rate on the right hand +side so that would be the constant so + + align:start position:0% +side so that would be the constant so + + + align:start position:0% +side so that would be the constant so +it's constant plus Theta times this guy + + align:start position:0% +it's constant plus Theta times this guy + + + align:start position:0% +it's constant plus Theta times this guy +and let me Define these terms a little + + align:start position:0% +and let me Define these terms a little + + + align:start position:0% +and let me Define these terms a little +bit R Prime J no longer has an I on it + + align:start position:0% +bit R Prime J no longer has an I on it + + + align:start position:0% +bit R Prime J no longer has an I on it +because it's the weighted return over + + align:start position:0% +because it's the weighted return over + + + align:start position:0% +because it's the weighted return over +all the activities run by household J + + align:start position:0% +all the activities run by household J + + + align:start position:0% +all the activities run by household J +likewise the return for the whole + + align:start position:0% +likewise the return for the whole + + + align:start position:0% +likewise the return for the whole +Village Market if you like m is the + + align:start position:0% +Village Market if you like m is the + + + align:start position:0% +Village Market if you like m is the +weighted average return over all + + align:start position:0% +weighted average return over all + + + align:start position:0% +weighted average return over all +activities and all households so you + + align:start position:0% +activities and all households so you + + + align:start position:0% +activities and all households so you +take the capitalization of activity I + + align:start position:0% +take the capitalization of activity I + + + align:start position:0% +take the capitalization of activity I +run by household Jay look at the return + + align:start position:0% +run by household Jay look at the return + + + align:start position:0% +run by household Jay look at the return +on that as up here activity I run by + + align:start position:0% +on that as up here activity I run by + + + align:start position:0% +on that as up here activity I run by +household J some over for the household + + align:start position:0% +household J some over for the household + + + align:start position:0% +household J some over for the household +all activities I some over all + + align:start position:0% +all activities I some over all + + + align:start position:0% +all activities I some over all +households J you're getting a total + + align:start position:0% +households J you're getting a total + + + align:start position:0% +households J you're getting a total +return over all activities in all + + align:start position:0% +return over all activities in all + + + align:start position:0% +return over all activities in all +households and to get a rate of return + + align:start position:0% +households and to get a rate of return + + + align:start position:0% +households and to get a rate of return +you divide by the level of + + align:start position:0% +you divide by the level of + + + align:start position:0% +you divide by the level of +capitalization and the total level of + + align:start position:0% +capitalization and the total level of + + + align:start position:0% +capitalization and the total level of +capitalization is just the sum of the + + align:start position:0% +capitalization is just the sum of the + + + align:start position:0% +capitalization is just the sum of the +capitals over all activities and + + align:start position:0% +capitals over all activities and + + + align:start position:0% +capitals over all activities and +projects and what is this beta this beta + + align:start position:0% +projects and what is this beta this beta + + + align:start position:0% +projects and what is this beta this beta +is just a covariance divided by a + + align:start position:0% +is just a covariance divided by a + + + align:start position:0% +is just a covariance divided by a +variance as I've said it's going to be a + + align:start position:0% +variance as I've said it's going to be a + + + align:start position:0% +variance as I've said it's going to be a +regression coefficient if you're used to + + align:start position:0% +regression coefficient if you're used to + + + align:start position:0% +regression coefficient if you're used to +ordinary least squares you know that a + + align:start position:0% +ordinary least squares you know that a + + + align:start position:0% +ordinary least squares you know that a +regression coefficient is X Prime X + + align:start position:0% +regression coefficient is X Prime X + + + align:start position:0% +regression coefficient is X Prime X +inverse X Prime y so X must be in the + + align:start position:0% +inverse X Prime y so X must be in the + + + align:start position:0% +inverse X Prime y so X must be in the +denominator here which means that we're + + align:start position:0% +denominator here which means that we're + + + align:start position:0% +denominator here which means that we're +running on the right hand side the total + + align:start position:0% +running on the right hand side the total + + + align:start position:0% +running on the right hand side the total +Market Village return and on the left + + align:start position:0% +Market Village return and on the left + + + align:start position:0% +Market Village return and on the left +hand side the dependent variable is + + align:start position:0% +hand side the dependent variable is + + + align:start position:0% +hand side the dependent variable is +going to be the return of household + + align:start position:0% +going to be the return of household + + + align:start position:0% +going to be the return of household +chain so we're going to regress the + + align:start position:0% +chain so we're going to regress the + + + align:start position:0% +chain so we're going to regress the +return of household J over all the + + align:start position:0% +return of household J over all the + + + align:start position:0% +return of household J over all the +periods of the sample onto the + + align:start position:0% +periods of the sample onto the + + + align:start position:0% +periods of the sample onto the +aggregated village level return and get + + align:start position:0% +aggregated village level return and get + + + align:start position:0% +aggregated village level return and get +a regression coefficient and that's + + align:start position:0% +a regression coefficient and that's + + + align:start position:0% +a regression coefficient and that's +going to be beta J and that's going to + + align:start position:0% +going to be beta J and that's going to + + + align:start position:0% +going to be beta J and that's going to +capture how much the activities run by + + align:start position:0% +capture how much the activities run by + + + align:start position:0% +capture how much the activities run by +household J are covarying with what the + + align:start position:0% +household J are covarying with what the + + + align:start position:0% +household J are covarying with what the +village is doing as a whole + + align:start position:0% +village is doing as a whole + + + align:start position:0% +village is doing as a whole +now this as I think I explained to you + + align:start position:0% +now this as I think I explained to you + + + align:start position:0% +now this as I think I explained to you +last time I could go from here to here + + align:start position:0% +last time I could go from here to here + + + align:start position:0% +last time I could go from here to here +and it would all just look like some + + align:start position:0% +and it would all just look like some + + + align:start position:0% +and it would all just look like some +kind of claim go see the paper if you + + align:start position:0% +kind of claim go see the paper if you + + + align:start position:0% +kind of claim go see the paper if you +don't read the paper it remains + + align:start position:0% +don't read the paper it remains + + + align:start position:0% +don't read the paper it remains +mysterious you have an extra level of + + align:start position:0% +mysterious you have an extra level of + + + align:start position:0% +mysterious you have an extra level of +abstraction you don't believe the + + align:start position:0% +abstraction you don't believe the + + + align:start position:0% +abstraction you don't believe the +results so I actually wrote in the + + align:start position:0% +results so I actually wrote in the + + + align:start position:0% +results so I actually wrote in the +algebra I am not going to go through it + + align:start position:0% +algebra I am not going to go through it + + + align:start position:0% +algebra I am not going to go through it +today because it is nothing other than + + align:start position:0% +today because it is nothing other than + + + align:start position:0% +today because it is nothing other than +algebra + + align:start position:0% +algebra + + + align:start position:0% +algebra +but it's how to take those two + + align:start position:0% +but it's how to take those two + + + align:start position:0% +but it's how to take those two +assumptions about quadratic utility and + + align:start position:0% +assumptions about quadratic utility and + + + align:start position:0% +assumptions about quadratic utility and +production functions and actually + + align:start position:0% +production functions and actually + + + align:start position:0% +production functions and actually +manipulate the equations we already had + + align:start position:0% +manipulate the equations we already had + + + align:start position:0% +manipulate the equations we already had +substituting in these particular + + align:start position:0% +substituting in these particular + + + align:start position:0% +substituting in these particular +expressions and getting at the bottom + + align:start position:0% +expressions and getting at the bottom + + + align:start position:0% +expressions and getting at the bottom +the expression that corresponds to to + + align:start position:0% +the expression that corresponds to to + + + align:start position:0% +the expression that corresponds to to +this okay but I'm going to skip that so + + align:start position:0% +this okay but I'm going to skip that so + + + align:start position:0% +this okay but I'm going to skip that so +again mechanically take the return of + + align:start position:0% +again mechanically take the return of + + + align:start position:0% +again mechanically take the return of +household J at date at er T regress it + + align:start position:0% +household J at date at er T regress it + + + align:start position:0% +household J at date at er T regress it +on to constant and on to the time series + + align:start position:0% +on to constant and on to the time series + + + align:start position:0% +on to constant and on to the time series +of the market return + + align:start position:0% +of the market return + + + align:start position:0% +of the market return +yeah this is actually a prime here we're + + align:start position:0% +yeah this is actually a prime here we're + + + align:start position:0% +yeah this is actually a prime here we're +having trouble editing you know these + + align:start position:0% +having trouble editing you know these + + + align:start position:0% +having trouble editing you know these +latex files I guess so this is a prime + + align:start position:0% +latex files I guess so this is a prime + + + align:start position:0% +latex files I guess so this is a prime +so we have Prime this could be all today + + align:start position:0% +so we have Prime this could be all today + + + align:start position:0% +so we have Prime this could be all today +today or it could be next period next + + align:start position:0% +today or it could be next period next + + + align:start position:0% +today or it could be next period next +period just be consistent about it so + + align:start position:0% +period just be consistent about it so + + + align:start position:0% +period just be consistent about it so +the return of household J at day t + + align:start position:0% +the return of household J at day t + + + align:start position:0% +the return of household J at day t +regressed on to the reach the village + + align:start position:0% +regressed on to the reach the village + + + align:start position:0% +regressed on to the reach the village +level return at dates T running over all + + align:start position:0% +level return at dates T running over all + + + align:start position:0% +level return at dates T running over all +T so the sample could you know I'll show + + align:start position:0% +T so the sample could you know I'll show + + + align:start position:0% +T so the sample could you know I'll show +you in a minute something like 10 years + + align:start position:0% +you in a minute something like 10 years + + + align:start position:0% +you in a minute something like 10 years +of data a bit more + + align:start position:0% +of data a bit more + + + align:start position:0% +of data a bit more +plus an Epsilon is like the error term + + align:start position:0% +plus an Epsilon is like the error term + + + align:start position:0% +plus an Epsilon is like the error term +after you run this regression using the + + align:start position:0% +after you run this regression using the + + + align:start position:0% +after you run this regression using the +time series for each household one at a + + align:start position:0% +time series for each household one at a + + + align:start position:0% +time series for each household one at a +time and having estimated these beta J's + + align:start position:0% +time and having estimated these beta J's + + + align:start position:0% +time and having estimated these beta J's +we now run the next regression which is + + align:start position:0% +we now run the next regression which is + + + align:start position:0% +we now run the next regression which is +entirely cross-sectional regression we + + align:start position:0% +entirely cross-sectional regression we + + + align:start position:0% +entirely cross-sectional regression we +compute for each household the average + + align:start position:0% +compute for each household the average + + + align:start position:0% +compute for each household the average +return over the entire sample which is a + + align:start position:0% +return over the entire sample which is a + + + align:start position:0% +return over the entire sample which is a +proxy for the household's expected + + align:start position:0% +proxy for the household's expected + + + align:start position:0% +proxy for the household's expected +return the data analog to that and we + + align:start position:0% +return the data analog to that and we + + + align:start position:0% +return the data analog to that and we +regress that for each household J onto + + align:start position:0% +regress that for each household J onto + + + align:start position:0% +regress that for each household J onto +its beta J as derived in the first + + align:start position:0% +its beta J as derived in the first + + + align:start position:0% +its beta J as derived in the first +equation step one so the economics here + + align:start position:0% +equation step one so the economics here + + + align:start position:0% +equation step one so the economics here +is the return on the project run by + + align:start position:0% +is the return on the project run by + + + align:start position:0% +is the return on the project run by +household J the expected return should + + align:start position:0% +household J the expected return should + + + align:start position:0% +household J the expected return should +equal say roughly the risk-free rate but + + align:start position:0% +equal say roughly the risk-free rate but + + + align:start position:0% +equal say roughly the risk-free rate but +it has a risk premium first time I've + + align:start position:0% +it has a risk premium first time I've + + + align:start position:0% +it has a risk premium first time I've +used that now with the notation and the + + align:start position:0% +used that now with the notation and the + + + align:start position:0% +used that now with the notation and the +risk premium has to do with the + + align:start position:0% +risk premium has to do with the + + + align:start position:0% +risk premium has to do with the +co-movement of household Jay's activity + + align:start position:0% +co-movement of household Jay's activity + + + align:start position:0% +co-movement of household Jay's activity +with the village aggregate + + align:start position:0% +with the village aggregate + + + align:start position:0% +with the village aggregate +so we talked about diversification at + + align:start position:0% +so we talked about diversification at + + + align:start position:0% +so we talked about diversification at +the beginning of class and the idea here + + align:start position:0% +the beginning of class and the idea here + + + align:start position:0% +the beginning of class and the idea here +is if the things household J is doing + + align:start position:0% +is if the things household J is doing + + + align:start position:0% +is if the things household J is doing +are highly correlated with returns on + + align:start position:0% +are highly correlated with returns on + + + align:start position:0% +are highly correlated with returns on +what other people are doing then + + align:start position:0% +what other people are doing then + + + align:start position:0% +what other people are doing then +household J isn't doing very much + + align:start position:0% +household J isn't doing very much + + + align:start position:0% +household J isn't doing very much +worthwhile Council J is not diversifying + + align:start position:0% +worthwhile Council J is not diversifying + + + align:start position:0% +worthwhile Council J is not diversifying +The Village level risk so in order to + + align:start position:0% +The Village level risk so in order to + + + align:start position:0% +The Village level risk so in order to +justify a set of activities that + + align:start position:0% +justify a set of activities that + + + align:start position:0% +justify a set of activities that +household J is doing we have to bump up + + align:start position:0% +household J is doing we have to bump up + + + align:start position:0% +household J is doing we have to bump up +its expected rate of return in some + + align:start position:0% +its expected rate of return in some + + + align:start position:0% +its expected rate of return in some +sense we use the word risk premium + + align:start position:0% +sense we use the word risk premium + + + align:start position:0% +sense we use the word risk premium +meaning household Jazz activities are + + align:start position:0% +meaning household Jazz activities are + + + align:start position:0% +meaning household Jazz activities are +pretty risky why because they're + + align:start position:0% +pretty risky why because they're + + + align:start position:0% +pretty risky why because they're +correlated with the village average so + + align:start position:0% +correlated with the village average so + + + align:start position:0% +correlated with the village average so +diversification is not and we need to + + align:start position:0% +diversification is not and we need to + + + align:start position:0% +diversification is not and we need to +compensate for that lack of + + align:start position:0% +compensate for that lack of + + + align:start position:0% +compensate for that lack of +diversification the opposite is more + + align:start position:0% +diversification the opposite is more + + + align:start position:0% +diversification the opposite is more +revealing perhaps which is if this + + align:start position:0% +revealing perhaps which is if this + + + align:start position:0% +revealing perhaps which is if this +correlation is low or even zero It's a + + align:start position:0% +correlation is low or even zero It's a + + + align:start position:0% +correlation is low or even zero It's a +Wonderful hedge even if not many + + align:start position:0% +Wonderful hedge even if not many + + + align:start position:0% +Wonderful hedge even if not many +households are doing those things if + + align:start position:0% +households are doing those things if + + + align:start position:0% +households are doing those things if +household J does them and manages to + + align:start position:0% +household J does them and manages to + + + align:start position:0% +household J does them and manages to +produce a return stream which is not so + + align:start position:0% +produce a return stream which is not so + + + align:start position:0% +produce a return stream which is not so +correlated with the return streams of + + align:start position:0% +correlated with the return streams of + + + align:start position:0% +correlated with the return streams of +the other households that's great in + + align:start position:0% +the other households that's great in + + + align:start position:0% +the other households that's great in +which case we don't need to have a high + + align:start position:0% +which case we don't need to have a high + + + align:start position:0% +which case we don't need to have a high +risk premium because actually it's + + align:start position:0% +risk premium because actually it's + + + align:start position:0% +risk premium because actually it's +reducing risk so that's the economics of + + align:start position:0% +reducing risk so that's the economics of + + + align:start position:0% +reducing risk so that's the economics of +it it's all also entirely here in terms + + align:start position:0% +it it's all also entirely here in terms + + + align:start position:0% +it it's all also entirely here in terms +of the equations all right I'm sorry I + + align:start position:0% +of the equations all right I'm sorry I + + + align:start position:0% +of the equations all right I'm sorry I +have a I have a question about a + + align:start position:0% +have a I have a question about a + + + align:start position:0% +have a I have a question about a +previous slide + + align:start position:0% +previous slide + + + align:start position:0% +previous slide +yeah so um is no uh it's more like a + + align:start position:0% +yeah so um is no uh it's more like a + + + align:start position:0% +yeah so um is no uh it's more like a +econometric stuff because um I think + + align:start position:0% +econometric stuff because um I think + + + align:start position:0% +econometric stuff because um I think +there should be some estimation error + + align:start position:0% +there should be some estimation error + + + align:start position:0% +there should be some estimation error +here because + + align:start position:0% +here because + + + align:start position:0% +here because +um the beta is estimated and in step two + + align:start position:0% +um the beta is estimated and in step two + + + align:start position:0% +um the beta is estimated and in step two +you just request you regressive return + + align:start position:0% +you just request you regressive return + + + align:start position:0% +you just request you regressive return +on some estimated beta right + + align:start position:0% +on some estimated beta right + + + align:start position:0% +on some estimated beta right +so + + align:start position:0% +so + + + align:start position:0% +so +I mean + + align:start position:0% +I mean + + + align:start position:0% +I mean +you you just really regrets some some + + align:start position:0% +you you just really regrets some some + + + align:start position:0% +you you just really regrets some some +some true data on some estimated data + + align:start position:0% +some true data on some estimated data + + + align:start position:0% +some true data on some estimated data +and I think the Lambda here will have + + align:start position:0% +and I think the Lambda here will have + + + align:start position:0% +and I think the Lambda here will have +some error right + + align:start position:0% +some error right + + + align:start position:0% +some error right +well there are two things + + align:start position:0% +well there are two things + + + align:start position:0% +well there are two things +to adjust for one this is a a regression + + align:start position:0% +to adjust for one this is a a regression + + + align:start position:0% +to adjust for one this is a a regression +coefficient so it is measured with error + + align:start position:0% +coefficient so it is measured with error + + + align:start position:0% +coefficient so it is measured with error +it has a standard error and we do adjust + + align:start position:0% +it has a standard error and we do adjust + + + align:start position:0% +it has a standard error and we do adjust +the beta that we're using to allow for + + align:start position:0% +the beta that we're using to allow for + + + align:start position:0% +the beta that we're using to allow for +that uncertainty if that's part of what + + align:start position:0% +that uncertainty if that's part of what + + + align:start position:0% +that uncertainty if that's part of what +you're asking + + align:start position:0% +you're asking + + + align:start position:0% +you're asking +is that what you're asking about + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +yeah probably but yeah okay okay yeah + + align:start position:0% +yeah probably but yeah okay okay yeah + + + align:start position:0% +yeah probably but yeah okay okay yeah +I mean the other thing is + + align:start position:0% +I mean the other thing is + + + align:start position:0% +I mean the other thing is +that you know + + align:start position:0% +that you know + + + align:start position:0% +that you know +um + + align:start position:0% +um + + + align:start position:0% +um +here we're regressing an individual J + + align:start position:0% +here we're regressing an individual J + + + align:start position:0% +here we're regressing an individual J +return on the village average so you do + + align:start position:0% +return on the village average so you do + + + align:start position:0% +return on the village average so you do +have to be worried about regressing + + align:start position:0% +have to be worried about regressing + + + align:start position:0% +have to be worried about regressing +dependent variables on the left with + + align:start position:0% +dependent variables on the left with + + + align:start position:0% +dependent variables on the left with +their average on the right + + align:start position:0% +their average on the right + + + align:start position:0% +their average on the right +you know that tends to bias this beta + + align:start position:0% +you know that tends to bias this beta + + + align:start position:0% +you know that tends to bias this beta +toward one + + align:start position:0% +toward one + + + align:start position:0% +toward one +that's another econometric problem + + align:start position:0% +that's another econometric problem + + + align:start position:0% +that's another econometric problem +except that here + + align:start position:0% +except that here + + + align:start position:0% +except that here +we're actually interested in dispersion + + align:start position:0% +we're actually interested in dispersion + + + align:start position:0% +we're actually interested in dispersion +across the different betas + + align:start position:0% +across the different betas + + + align:start position:0% +across the different betas +and so we're okay + + align:start position:0% +and so we're okay + + + align:start position:0% +and so we're okay +uh and this + + align:start position:0% +uh and this + + + align:start position:0% +uh and this +is Fama French + + align:start position:0% +is Fama French + + + align:start position:0% +is Fama French +which I suspect you know + + align:start position:0% +which I suspect you know + + + align:start position:0% +which I suspect you know +yeah I know that yeah yeah so we're just + + align:start position:0% +yeah I know that yeah yeah so we're just + + + align:start position:0% +yeah I know that yeah yeah so we're just +doing + + align:start position:0% +doing + + + align:start position:0% +doing +what they did with the New York stocks + + align:start position:0% +what they did with the New York stocks + + + align:start position:0% +what they did with the New York stocks +we're doing it here in the five villages + + align:start position:0% +we're doing it here in the five villages + + + align:start position:0% +we're doing it here in the five villages +okay + + align:start position:0% +okay + + + align:start position:0% +okay +we started our survey in 1998 with a big + + align:start position:0% +we started our survey in 1998 with a big + + + align:start position:0% +we started our survey in 1998 with a big +Baseline we updated every month + + align:start position:0% +Baseline we updated every month + + + align:start position:0% +Baseline we updated every month +uh thereafter this said at the time we + + align:start position:0% +uh thereafter this said at the time we + + + align:start position:0% +uh thereafter this said at the time we +were writing the paper the survey was + + align:start position:0% +were writing the paper the survey was + + + align:start position:0% +were writing the paper the survey was +still ongoing + + align:start position:0% +still ongoing + + + align:start position:0% +still ongoing +although even then the later months were + + align:start position:0% +although even then the later months were + + + align:start position:0% +although even then the later months were +not ready so we ended up using monthly + + align:start position:0% +not ready so we ended up using monthly + + + align:start position:0% +not ready so we ended up using monthly +data from month five to month 160 of the + + align:start position:0% +data from month five to month 160 of the + + + align:start position:0% +data from month five to month 160 of the +survey now the other thing is misleading + + align:start position:0% +survey now the other thing is misleading + + + align:start position:0% +survey now the other thing is misleading +is not ongoing anymore the project ended + + align:start position:0% +is not ongoing anymore the project ended + + + align:start position:0% +is not ongoing anymore the project ended +about 18 months ago + + align:start position:0% +about 18 months ago + + + align:start position:0% +about 18 months ago +but we did end up with almost 20 years + + align:start position:0% +but we did end up with almost 20 years + + + align:start position:0% +but we did end up with almost 20 years +of monthly data so it's a vast Warehouse + + align:start position:0% +of monthly data so it's a vast Warehouse + + + align:start position:0% +of monthly data so it's a vast Warehouse +of you know potential projects that can + + align:start position:0% +of you know potential projects that can + + + align:start position:0% +of you know potential projects that can +be done with it and I'm happy to tell + + align:start position:0% +be done with it and I'm happy to tell + + + align:start position:0% +be done with it and I'm happy to tell +you more but today I want to focus on + + align:start position:0% +you more but today I want to focus on + + + align:start position:0% +you more but today I want to focus on +this paper so we only included the + + align:start position:0% +this paper so we only included the + + + align:start position:0% +this paper so we only included the +households that were actually in the + + align:start position:0% +households that were actually in the + + + align:start position:0% +households that were actually in the +village for the whole period sometimes + + align:start position:0% +village for the whole period sometimes + + + align:start position:0% +village for the whole period sometimes +entire households pick up stakes and + + align:start position:0% +entire households pick up stakes and + + + align:start position:0% +entire households pick up stakes and +leave + + align:start position:0% +leave + + + align:start position:0% +leave +we excluded them we also are looking + + align:start position:0% +we excluded them we also are looking + + + align:start position:0% +we excluded them we also are looking +only at households with production + + align:start position:0% +only at households with production + + + align:start position:0% +only at households with production +activities Farm is included but also + + align:start position:0% +activities Farm is included but also + + + align:start position:0% +activities Farm is included but also +fish shrimp livestock trade-in + + align:start position:0% +fish shrimp livestock trade-in + + + align:start position:0% +fish shrimp livestock trade-in +handicrafts but not just wage earnings + + align:start position:0% +handicrafts but not just wage earnings + + + align:start position:0% +handicrafts but not just wage earnings +why because with wage earnings they're + + align:start position:0% +why because with wage earnings they're + + + align:start position:0% +why because with wage earnings they're +not really producing anything they're + + align:start position:0% +not really producing anything they're + + + align:start position:0% +not really producing anything they're +earning something by working for others + + align:start position:0% +earning something by working for others + + + align:start position:0% +earning something by working for others +so they're not entrepreneurs so we did + + align:start position:0% +so they're not entrepreneurs so we did + + + align:start position:0% +so they're not entrepreneurs so we did +not include them + + align:start position:0% +not include them + + + align:start position:0% +not include them +and there are extensive networks of + + align:start position:0% +and there are extensive networks of + + + align:start position:0% +and there are extensive networks of +family in these Villages and I'm going + + align:start position:0% +family in these Villages and I'm going + + + align:start position:0% +family in these Villages and I'm going +to come back to that a little bit later + + align:start position:0% +to come back to that a little bit later + + + align:start position:0% +to come back to that a little bit later +toward the end so just to give you a + + align:start position:0% +toward the end so just to give you a + + + align:start position:0% +toward the end so just to give you a +feeling of the the data we've got net + + align:start position:0% +feeling of the the data we've got net + + + align:start position:0% +feeling of the the data we've got net +income which means + + align:start position:0% +income which means + + + align:start position:0% +income which means +income from household Enterprise it's + + align:start position:0% +income from household Enterprise it's + + + align:start position:0% +income from household Enterprise it's +the difference between revenue and costs + + align:start position:0% +the difference between revenue and costs + + + align:start position:0% +the difference between revenue and costs +of all the inputs revenue is realized at + + align:start position:0% +of all the inputs revenue is realized at + + + align:start position:0% +of all the inputs revenue is realized at +the time of sale or it could be if it's + + align:start position:0% +the time of sale or it could be if it's + + + align:start position:0% +the time of sale or it could be if it's +a crop it could be eaten it could be + + align:start position:0% +a crop it could be eaten it could be + + + align:start position:0% +a crop it could be eaten it could be +given as a gift from to others it all + + align:start position:0% +given as a gift from to others it all + + + align:start position:0% +given as a gift from to others it all +counts + + align:start position:0% +counts + + + align:start position:0% +counts +we add them all up uh Revenue even comes + + align:start position:0% +we add them all up uh Revenue even comes + + + align:start position:0% +we add them all up uh Revenue even comes +from renting out assets we include that + + align:start position:0% +from renting out assets we include that + + + align:start position:0% +from renting out assets we include that +costs are all the inputs used in + + align:start position:0% +costs are all the inputs used in + + + align:start position:0% +costs are all the inputs used in +production whether they're acquired in + + align:start position:0% +production whether they're acquired in + + + align:start position:0% +production whether they're acquired in +cash or in kind with credit or gifts + + align:start position:0% +cash or in kind with credit or gifts + + + align:start position:0% +cash or in kind with credit or gifts +we count them all we put a valuation on + + align:start position:0% +we count them all we put a valuation on + + + align:start position:0% +we count them all we put a valuation on +them if it's not acquired in the market + + align:start position:0% +them if it's not acquired in the market + + + align:start position:0% +them if it's not acquired in the market +so we take Revenue minus costs include + + align:start position:0% +so we take Revenue minus costs include + + + align:start position:0% +so we take Revenue minus costs include +depreciation that came up earlier + + align:start position:0% +depreciation that came up earlier + + + align:start position:0% +depreciation that came up earlier +subtracted and we get net income + + align:start position:0% +subtracted and we get net income + + + align:start position:0% +subtracted and we get net income +and these assets we're talking about you + + align:start position:0% +and these assets we're talking about you + + + align:start position:0% +and these assets we're talking about you +know we have agricultural business + + align:start position:0% +know we have agricultural business + + + align:start position:0% +know we have agricultural business +livestock assets we've also got land and + + align:start position:0% +livestock assets we've also got land and + + + align:start position:0% +livestock assets we've also got land and +household assets the agricultural assets + + align:start position:0% +household assets the agricultural assets + + + align:start position:0% +household assets the agricultural assets +to give you an example includes walking + + align:start position:0% +to give you an example includes walking + + + align:start position:0% +to give you an example includes walking +tractors you might remember in the + + align:start position:0% +tractors you might remember in the + + + align:start position:0% +tractors you might remember in the +production lecture I showed you a + + align:start position:0% +production lecture I showed you a + + + align:start position:0% +production lecture I showed you a +picture of that guy walking around with + + align:start position:0% +picture of that guy walking around with + + + align:start position:0% +picture of that guy walking around with +the tractor or larger four-wheel + + align:start position:0% +the tractor or larger four-wheel + + + align:start position:0% +the tractor or larger four-wheel +tractors aerators for ponds machines to + + align:start position:0% +tractors aerators for ponds machines to + + + align:start position:0% +tractors aerators for ponds machines to +put seeds in the ground machines like + + align:start position:0% +put seeds in the ground machines like + + + align:start position:0% +put seeds in the ground machines like +sprinklers + + align:start position:0% +sprinklers + + + align:start position:0% +sprinklers +Etc so you know you're in the village + + align:start position:0% +Etc so you know you're in the village + + + align:start position:0% +Etc so you know you're in the village +now you can imagine living there I think + + align:start position:0% +now you can imagine living there I think + + + align:start position:0% +now you can imagine living there I think +this is the level of detail that we have + + align:start position:0% +this is the level of detail that we have + + + align:start position:0% +this is the level of detail that we have +we did put household assets in that's a + + align:start position:0% +we did put household assets in that's a + + + align:start position:0% +we did put household assets in that's a +decision because some of the things that + + align:start position:0% +decision because some of the things that + + + align:start position:0% +decision because some of the things that +look like a durable good end up being + + align:start position:0% +look like a durable good end up being + + + align:start position:0% +look like a durable good end up being +used in farming like a pickup truck you + + align:start position:0% +used in farming like a pickup truck you + + + align:start position:0% +used in farming like a pickup truck you +know they use it so rather than include + + align:start position:0% +know they use it so rather than include + + + align:start position:0% +know they use it so rather than include +but we've done robustness checks but + + align:start position:0% +but we've done robustness checks but + + + align:start position:0% +but we've done robustness checks but +here we included them all okay so let me + + align:start position:0% +here we included them all okay so let me + + + align:start position:0% +here we included them all okay so let me +just jump here if we look at that beta + + align:start position:0% +just jump here if we look at that beta + + + align:start position:0% +just jump here if we look at that beta +this is the return on assets the + + align:start position:0% +this is the return on assets the + + + align:start position:0% +this is the return on assets the +expected return on household J + + align:start position:0% +expected return on household J + + + align:start position:0% +expected return on household J +each J corresponds to a DOT here and + + align:start position:0% +each J corresponds to a DOT here and + + + align:start position:0% +each J corresponds to a DOT here and +it's just the average return for + + align:start position:0% +it's just the average return for + + + align:start position:0% +it's just the average return for +household J on the y-axis and the beta + + align:start position:0% +household J on the y-axis and the beta + + + align:start position:0% +household J on the y-axis and the beta +the regression coefficient on the + + align:start position:0% +the regression coefficient on the + + + align:start position:0% +the regression coefficient on the +village average is on the x-axis + + align:start position:0% +village average is on the x-axis + + + align:start position:0% +village average is on the x-axis +so you can see that households have that + + align:start position:0% +so you can see that households have that + + + align:start position:0% +so you can see that households have that +have higher returns are households that + + align:start position:0% +have higher returns are households that + + + align:start position:0% +have higher returns are households that +have higher betas + + align:start position:0% +have higher betas + + + align:start position:0% +have higher betas +for three of the four + + align:start position:0% +for three of the four + + + align:start position:0% +for three of the four +potentially all four although Bergeron + + align:start position:0% +potentially all four although Bergeron + + + align:start position:0% +potentially all four although Bergeron +is not not the greatest example + + align:start position:0% +is not not the greatest example + + + align:start position:0% +is not not the greatest example +and I have shown this picture to guys + + align:start position:0% +and I have shown this picture to guys + + + align:start position:0% +and I have shown this picture to guys +working in finance with New York Stock + + align:start position:0% +working in finance with New York Stock + + + align:start position:0% +working in finance with New York Stock +Exchange or Swedish data and they see + + align:start position:0% +Exchange or Swedish data and they see + + + align:start position:0% +Exchange or Swedish data and they see +this degree of correlation and they're + + align:start position:0% +this degree of correlation and they're + + + align:start position:0% +this degree of correlation and they're +like wow that's really amazing so the + + align:start position:0% +like wow that's really amazing so the + + + align:start position:0% +like wow that's really amazing so the +theory is working pretty well + + align:start position:0% +theory is working pretty well + + + align:start position:0% +theory is working pretty well +and this is the regression doesn't + + align:start position:0% +and this is the regression doesn't + + + align:start position:0% +and this is the regression doesn't +really add more this is the regression + + align:start position:0% +really add more this is the regression + + + align:start position:0% +really add more this is the regression +from that step one with the + + align:start position:0% +from that step one with the + + + align:start position:0% +from that step one with the +corresponding sorry step two it is with + + align:start position:0% +corresponding sorry step two it is with + + + align:start position:0% +corresponding sorry step two it is with +the corresponding betas and it's not + + align:start position:0% +the corresponding betas and it's not + + + align:start position:0% +the corresponding betas and it's not +significant number around but it is in + + align:start position:0% +significant number around but it is in + + + align:start position:0% +significant number around but it is in +the other three provinces not sure if + + align:start position:0% +the other three provinces not sure if + + + align:start position:0% +the other three provinces not sure if +I've shown you this map I don't think we + + align:start position:0% +I've shown you this map I don't think we + + + align:start position:0% +I've shown you this map I don't think we +did chachang Sao and lopuri are + + align:start position:0% +did chachang Sao and lopuri are + + + align:start position:0% +did chachang Sao and lopuri are +relatively near to Bangkok + + align:start position:0% +relatively near to Bangkok + + + align:start position:0% +relatively near to Bangkok +and birder rum and sitsakata are out in + + align:start position:0% +and birder rum and sitsakata are out in + + + align:start position:0% +and birder rum and sitsakata are out in +The Agrarian regions of the Northeast so + + align:start position:0% +The Agrarian regions of the Northeast so + + + align:start position:0% +The Agrarian regions of the Northeast so +very different types of sample okay so + + align:start position:0% +very different types of sample okay so + + + align:start position:0% +very different types of sample okay so +let's talk about idiosyncratic risk the + + align:start position:0% +let's talk about idiosyncratic risk the + + + align:start position:0% +let's talk about idiosyncratic risk the +return on household J is determined by + + align:start position:0% +return on household J is determined by + + + align:start position:0% +return on household J is determined by +Beta J that we've been talking about X + + align:start position:0% +Beta J that we've been talking about X + + + align:start position:0% +Beta J that we've been talking about X +is to make the argument more General so + + align:start position:0% +is to make the argument more General so + + + align:start position:0% +is to make the argument more General so +bait regression coefficients times the + + align:start position:0% +bait regression coefficients times the + + + align:start position:0% +bait regression coefficients times the +object + + align:start position:0% +object + + + align:start position:0% +object +and then an error term so if you take + + align:start position:0% +and then an error term so if you take + + + align:start position:0% +and then an error term so if you take +the variance of both sides doing a + + align:start position:0% +the variance of both sides doing a + + + align:start position:0% +the variance of both sides doing a +variance decomposition the variance of + + align:start position:0% +variance decomposition the variance of + + + align:start position:0% +variance decomposition the variance of +the return is the variance explained by + + align:start position:0% +the return is the variance explained by + + + align:start position:0% +the return is the variance explained by +the dependent variable with its + + align:start position:0% +the dependent variable with its + + + align:start position:0% +the dependent variable with its +coefficient plus the variance of the + + align:start position:0% +coefficient plus the variance of the + + + align:start position:0% +coefficient plus the variance of the +error term so when we talk about + + align:start position:0% +error term so when we talk about + + + align:start position:0% +error term so when we talk about +idiosyncratic risk we're talking about + + align:start position:0% +idiosyncratic risk we're talking about + + + align:start position:0% +idiosyncratic risk we're talking about +the error term here + + align:start position:0% +the error term here + + + align:start position:0% +the error term here +as opposed to how much of the variance + + align:start position:0% +as opposed to how much of the variance + + + align:start position:0% +as opposed to how much of the variance +is determined by The Village aggregate + + align:start position:0% +is determined by The Village aggregate + + + align:start position:0% +is determined by The Village aggregate +and so you could just imagine taking + + align:start position:0% +and so you could just imagine taking + + + align:start position:0% +and so you could just imagine taking +this variance term and dividing it + + align:start position:0% +this variance term and dividing it + + + align:start position:0% +this variance term and dividing it +through both sides and then you'll have + + align:start position:0% +through both sides and then you'll have + + + align:start position:0% +through both sides and then you'll have +one like 100 percent is equal to the + + align:start position:0% +one like 100 percent is equal to the + + + align:start position:0% +one like 100 percent is equal to the +contribution of the of the village + + align:start position:0% +contribution of the of the village + + + align:start position:0% +contribution of the of the village +return plus the contribution of the + + align:start position:0% +return plus the contribution of the + + + align:start position:0% +return plus the contribution of the +idiosyncratic variance to the total so + + align:start position:0% +idiosyncratic variance to the total so + + + align:start position:0% +idiosyncratic variance to the total so +this is not a theory this is a way of + + align:start position:0% +this is not a theory this is a way of + + + align:start position:0% +this is not a theory this is a way of +quantifying how much aggregate Village + + align:start position:0% +quantifying how much aggregate Village + + + align:start position:0% +quantifying how much aggregate Village +average risk there is and how much + + align:start position:0% +average risk there is and how much + + + align:start position:0% +average risk there is and how much +idiosyncratic risk there is in an + + align:start position:0% +idiosyncratic risk there is in an + + + align:start position:0% +idiosyncratic risk there is in an +individual J's return + + align:start position:0% +individual J's return + + + align:start position:0% +individual J's return +now the next thing back to the + + align:start position:0% +now the next thing back to the + + + align:start position:0% +now the next thing back to the +regression as I have been saying in the + + align:start position:0% +regression as I have been saying in the + + + align:start position:0% +regression as I have been saying in the +Baseline we're running the average + + align:start position:0% +Baseline we're running the average + + + align:start position:0% +Baseline we're running the average +return on household J onto a constant + + align:start position:0% +return on household J onto a constant + + + align:start position:0% +return on household J onto a constant +plus the beta J coefficient times beta J + + align:start position:0% +plus the beta J coefficient times beta J + + + align:start position:0% +plus the beta J coefficient times beta J +and now we do something extra + + align:start position:0% +and now we do something extra + + + align:start position:0% +and now we do something extra +we add in Sigma J where Sigma J here is + + align:start position:0% +we add in Sigma J where Sigma J here is + + + align:start position:0% +we add in Sigma J where Sigma J here is +the variance of this Epsilon term how + + align:start position:0% +the variance of this Epsilon term how + + + align:start position:0% +the variance of this Epsilon term how +much is it moving well it's right here + + align:start position:0% +much is it moving well it's right here + + + align:start position:0% +much is it moving well it's right here +except that I didn't call it Sigma J + + align:start position:0% +except that I didn't call it Sigma J + + + align:start position:0% +except that I didn't call it Sigma J +here the variance of Epsilon J is Sigma + + align:start position:0% +here the variance of Epsilon J is Sigma + + + align:start position:0% +here the variance of Epsilon J is Sigma +J stick that into this cross-sectional + + align:start position:0% +J stick that into this cross-sectional + + + align:start position:0% +J stick that into this cross-sectional +regression as an extra right-hand side + + align:start position:0% +regression as an extra right-hand side + + + align:start position:0% +regression as an extra right-hand side +variable and get a coefficient on it so + + align:start position:0% +variable and get a coefficient on it so + + + align:start position:0% +variable and get a coefficient on it so +now we can do a similar calculation we + + align:start position:0% +now we can do a similar calculation we + + + align:start position:0% +now we can do a similar calculation we +can take the risk premium which is the + + align:start position:0% +can take the risk premium which is the + + + align:start position:0% +can take the risk premium which is the +sum of both the return over and above + + align:start position:0% +sum of both the return over and above + + + align:start position:0% +sum of both the return over and above +the risk-free rate that's due to the + + align:start position:0% +the risk-free rate that's due to the + + + align:start position:0% +the risk-free rate that's due to the +aggregate return and also due to the + + align:start position:0% +aggregate return and also due to the + + + align:start position:0% +aggregate return and also due to the +idiosyncratic risk and so we can + + align:start position:0% +idiosyncratic risk and so we can + + + align:start position:0% +idiosyncratic risk and so we can +decompose the aggregate risk as a + + align:start position:0% +decompose the aggregate risk as a + + + align:start position:0% +decompose the aggregate risk as a +proportion of the total and likewise the + + align:start position:0% +proportion of the total and likewise the + + + align:start position:0% +proportion of the total and likewise the +idiosyncratic risk as the proportion of + + align:start position:0% +idiosyncratic risk as the proportion of + + + align:start position:0% +idiosyncratic risk as the proportion of +the total + + align:start position:0% +the total + + + align:start position:0% +the total +question + + align:start position:0% +question + + + align:start position:0% +question +so doing that we + + align:start position:0% +so doing that we + + + align:start position:0% +so doing that we +summarize the results the contribution + + align:start position:0% +summarize the results the contribution + + + align:start position:0% +summarize the results the contribution +of idiosyncratic risk to Total risk and + + align:start position:0% +of idiosyncratic risk to Total risk and + + + align:start position:0% +of idiosyncratic risk to Total risk and +the contribution of idiosyncratic risk + + align:start position:0% +the contribution of idiosyncratic risk + + + align:start position:0% +the contribution of idiosyncratic risk +to the risk premium the contribution of + + align:start position:0% +to the risk premium the contribution of + + + align:start position:0% +to the risk premium the contribution of +idiosyncratic risk to the total variance + + align:start position:0% +idiosyncratic risk to the total variance + + + align:start position:0% +idiosyncratic risk to the total variance +is huge + + align:start position:0% +is huge + + + align:start position:0% +is huge +this row here + + align:start position:0% +this row here + + + align:start position:0% +this row here +running across the villages and looking + + align:start position:0% +running across the villages and looking + + + align:start position:0% +running across the villages and looking +at the quartiles including the median he + + align:start position:0% +at the quartiles including the median he + + + align:start position:0% +at the quartiles including the median he +got 98 of it 97 of it 94 of it 65 + + align:start position:0% +got 98 of it 97 of it 94 of it 65 + + + align:start position:0% +got 98 of it 97 of it 94 of it 65 +percent of the risk is coming from the + + align:start position:0% +percent of the risk is coming from the + + + align:start position:0% +percent of the risk is coming from the +idiosyncratic component coming from this + + align:start position:0% +idiosyncratic component coming from this + + + align:start position:0% +idiosyncratic component coming from this +guy + + align:start position:0% +guy + + + align:start position:0% +guy +let me back up coming from this guy + + align:start position:0% +let me back up coming from this guy + + + align:start position:0% +let me back up coming from this guy +second row of this table is the + + align:start position:0% +second row of this table is the + + + align:start position:0% +second row of this table is the +contribution to the risk premium of the + + align:start position:0% +contribution to the risk premium of the + + + align:start position:0% +contribution to the risk premium of the +idiosyncratic risk and it's pretty small + + align:start position:0% +idiosyncratic risk and it's pretty small + + + align:start position:0% +idiosyncratic risk and it's pretty small +two things to note it's almost always + + align:start position:0% +two things to note it's almost always + + + align:start position:0% +two things to note it's almost always +lower than the quantity so the risk + + align:start position:0% +lower than the quantity so the risk + + + align:start position:0% +lower than the quantity so the risk +premium here it's also small here it's + + align:start position:0% +premium here it's also small here it's + + + align:start position:0% +premium here it's also small here it's +21 percent which isn't trivial or even + + align:start position:0% +21 percent which isn't trivial or even + + + align:start position:0% +21 percent which isn't trivial or even +here 45 percent but the 45 percent is + + align:start position:0% +here 45 percent but the 45 percent is + + + align:start position:0% +here 45 percent but the 45 percent is +still less than the 99 so the + + align:start position:0% +still less than the 99 so the + + + align:start position:0% +still less than the 99 so the +contribution to the risk premium in + + align:start position:0% +contribution to the risk premium in + + + align:start position:0% +contribution to the risk premium in +terms of the compensating returns + + align:start position:0% +terms of the compensating returns + + + align:start position:0% +terms of the compensating returns +required for the household to run that + + align:start position:0% +required for the household to run that + + + align:start position:0% +required for the household to run that +those Technologies is always the + + align:start position:0% +those Technologies is always the + + + align:start position:0% +those Technologies is always the +contribution to the total risk is always + + align:start position:0% +contribution to the total risk is always + + + align:start position:0% +contribution to the total risk is always +greater than the risk premium + + align:start position:0% +greater than the risk premium + + + align:start position:0% +greater than the risk premium +except for Iran kind of screws up over + + align:start position:0% +except for Iran kind of screws up over + + + align:start position:0% +except for Iran kind of screws up over +here but as you've seen pretty rum + + align:start position:0% +here but as you've seen pretty rum + + + align:start position:0% +here but as you've seen pretty rum +screws up in other ways and then we do a + + align:start position:0% +screws up in other ways and then we do a + + + align:start position:0% +screws up in other ways and then we do a +robustness check + + align:start position:0% +robustness check + + + align:start position:0% +robustness check +question + + align:start position:0% + + + + align:start position:0% + +okay back to the economics + + align:start position:0% +okay back to the economics + + + align:start position:0% +okay back to the economics +plan the medieval Villages scattered + + align:start position:0% +plan the medieval Villages scattered + + + align:start position:0% +plan the medieval Villages scattered +around random returns + + align:start position:0% +around random returns + + + align:start position:0% +around random returns +you know should they diversify do they + + align:start position:0% +you know should they diversify do they + + + align:start position:0% +you know should they diversify do they +do different activities Etc + + align:start position:0% +do different activities Etc + + + align:start position:0% +do different activities Etc +well that depends on the level of risk + + align:start position:0% +well that depends on the level of risk + + + align:start position:0% +well that depends on the level of risk +and it turns out there's a lot of risk + + align:start position:0% +and it turns out there's a lot of risk + + + align:start position:0% +and it turns out there's a lot of risk +but a lot of it is plot specific or + + align:start position:0% +but a lot of it is plot specific or + + + align:start position:0% +but a lot of it is plot specific or +activity specific + + align:start position:0% +activity specific + + + align:start position:0% +activity specific +most of it is idiosyncratic and not + + align:start position:0% +most of it is idiosyncratic and not + + + align:start position:0% +most of it is idiosyncratic and not +aggregate it is not true that the + + align:start position:0% +aggregate it is not true that the + + + align:start position:0% +aggregate it is not true that the +returns are co-moving much across all + + align:start position:0% +returns are co-moving much across all + + + align:start position:0% +returns are co-moving much across all +these activities + + align:start position:0% +these activities + + + align:start position:0% +these activities +so it's a very risky place as in India + + align:start position:0% +so it's a very risky place as in India + + + align:start position:0% +so it's a very risky place as in India +but there are plenty of diversification + + align:start position:0% +but there are plenty of diversification + + + align:start position:0% +but there are plenty of diversification +possibilities by holding multiple + + align:start position:0% +possibilities by holding multiple + + + align:start position:0% +possibilities by holding multiple +activities + + align:start position:0% +activities + + + align:start position:0% +activities +Etc so we're back to a version of what + + align:start position:0% +Etc so we're back to a version of what + + + align:start position:0% +Etc so we're back to a version of what +we did in medieval Villages right how + + align:start position:0% +we did in medieval Villages right how + + + align:start position:0% +we did in medieval Villages right how +much did they hold different plots here + + align:start position:0% +much did they hold different plots here + + + align:start position:0% +much did they hold different plots here +we are asking how much do they hold + + align:start position:0% +we are asking how much do they hold + + + align:start position:0% +we are asking how much do they hold +different activities and what can be + + align:start position:0% +different activities and what can be + + + align:start position:0% +different activities and what can be +accomplished by doing that and moreover + + align:start position:0% +accomplished by doing that and moreover + + + align:start position:0% +accomplished by doing that and moreover +since it's idiosyncratic you can kind of + + align:start position:0% +since it's idiosyncratic you can kind of + + + align:start position:0% +since it's idiosyncratic you can kind of +hope that it might get the risk premium + + align:start position:0% +hope that it might get the risk premium + + + align:start position:0% +hope that it might get the risk premium +for the idiosyncratic stuff might get + + align:start position:0% +for the idiosyncratic stuff might get + + + align:start position:0% +for the idiosyncratic stuff might get +small anyway all of this is from the + + align:start position:0% +small anyway all of this is from the + + + align:start position:0% +small anyway all of this is from the +production data let's look at the + + align:start position:0% +production data let's look at the + + + align:start position:0% +production data let's look at the +consumption data and in particular look + + align:start position:0% +consumption data and in particular look + + + align:start position:0% +consumption data and in particular look +at the gifts so now we're going from + + align:start position:0% +at the gifts so now we're going from + + + align:start position:0% +at the gifts so now we're going from +medieval Villages so to speak in terms + + align:start position:0% +medieval Villages so to speak in terms + + + align:start position:0% +medieval Villages so to speak in terms +of plots and production to India in + + align:start position:0% +of plots and production to India in + + + align:start position:0% +of plots and production to India in +terms of exposed consumption smoothing + + align:start position:0% +terms of exposed consumption smoothing + + + align:start position:0% +terms of exposed consumption smoothing +the gifts and transfers are the x-post + + align:start position:0% +the gifts and transfers are the x-post + + + align:start position:0% +the gifts and transfers are the x-post +part + + align:start position:0% +part + + + align:start position:0% +part +it's how much they would give money to + + align:start position:0% +it's how much they would give money to + + + align:start position:0% +it's how much they would give money to +each other + + align:start position:0% +each other + + + align:start position:0% +each other +starting from do actually give money to + + align:start position:0% +starting from do actually give money to + + + align:start position:0% +starting from do actually give money to +each other + + align:start position:0% +each other + + + align:start position:0% +each other +starting from the yields on their + + align:start position:0% +starting from the yields on their + + + align:start position:0% +starting from the yields on their +production activities + + align:start position:0% +production activities + + + align:start position:0% +production activities +so if you look back here again + + align:start position:0% +so if you look back here again + + + align:start position:0% +so if you look back here again +you would see these Epsilon so this + + align:start position:0% +you would see these Epsilon so this + + + align:start position:0% +you would see these Epsilon so this +could be high this could be low it's the + + align:start position:0% +could be high this could be low it's the + + + align:start position:0% +could be high this could be low it's the +variance is Big it's moving the returns + + align:start position:0% +variance is Big it's moving the returns + + + align:start position:0% +variance is Big it's moving the returns +around what happens when it's really big + + align:start position:0% +around what happens when it's really big + + + align:start position:0% +around what happens when it's really big +then this household got lucky it had a + + align:start position:0% +then this household got lucky it had a + + + align:start position:0% +then this household got lucky it had a +high return just lucky what does it do + + align:start position:0% +high return just lucky what does it do + + + align:start position:0% +high return just lucky what does it do +it gives stuff away + + align:start position:0% +it gives stuff away + + + align:start position:0% +it gives stuff away +or another version they get unlucky the + + align:start position:0% +or another version they get unlucky the + + + align:start position:0% +or another version they get unlucky the +Epsilon is low what do they do people + + align:start position:0% +Epsilon is low what do they do people + + + align:start position:0% +Epsilon is low what do they do people +give them gifts + + align:start position:0% +give them gifts + + + align:start position:0% +give them gifts +well I haven't actually shown your + + align:start position:0% +well I haven't actually shown your + + + align:start position:0% +well I haven't actually shown your +result but that's exactly what is going + + align:start position:0% +result but that's exactly what is going + + + align:start position:0% +result but that's exactly what is going +on in the data + + align:start position:0% +on in the data + + + align:start position:0% +on in the data +so if you regress those shocks those + + align:start position:0% +so if you regress those shocks those + + + align:start position:0% +so if you regress those shocks those +idiosyncratic shocks and on the right + + align:start position:0% +idiosyncratic shocks and on the right + + + align:start position:0% +idiosyncratic shocks and on the right +hand side onto gifts and net lending Etc + + align:start position:0% +hand side onto gifts and net lending Etc + + + align:start position:0% +hand side onto gifts and net lending Etc +you can see both there is an ultimate + + align:start position:0% +you can see both there is an ultimate + + + align:start position:0% +you can see both there is an ultimate +impact on consumption yes but it's small + + align:start position:0% +impact on consumption yes but it's small + + + align:start position:0% +impact on consumption yes but it's small +relative to the way they're mitigating + + align:start position:0% +relative to the way they're mitigating + + + align:start position:0% +relative to the way they're mitigating +the risk namely when the shock is high + + align:start position:0% +the risk namely when the shock is high + + + align:start position:0% +the risk namely when the shock is high +they're giving stuff away and lending it + + align:start position:0% +they're giving stuff away and lending it + + + align:start position:0% +they're giving stuff away and lending it +out and conversely when the shock is low + + align:start position:0% +out and conversely when the shock is low + + + align:start position:0% +out and conversely when the shock is low +they're getting this stuff in it depends + + align:start position:0% +they're getting this stuff in it depends + + + align:start position:0% +they're getting this stuff in it depends +on the sign this is net gift outflow + + align:start position:0% +on the sign this is net gift outflow + + + align:start position:0% +on the sign this is net gift outflow +when the shock is high it's positive + + align:start position:0% +when the shock is high it's positive + + + align:start position:0% +when the shock is high it's positive +it's statistically significant you can + + align:start position:0% +it's statistically significant you can + + + align:start position:0% +it's statistically significant you can +add up both gifts and borrowing and + + align:start position:0% +add up both gifts and borrowing and + + + align:start position:0% +add up both gifts and borrowing and +lending and get a bigger coefficient + + align:start position:0% +lending and get a bigger coefficient + + + align:start position:0% +lending and get a bigger coefficient +here it's 40. the 40 relative to the + + align:start position:0% +here it's 40. the 40 relative to the + + + align:start position:0% +here it's 40. the 40 relative to the +impact on consumption which is four in + + align:start position:0% +impact on consumption which is four in + + + align:start position:0% +impact on consumption which is four in +other words for every unit of + + align:start position:0% +other words for every unit of + + + align:start position:0% +other words for every unit of +idiosyncratic shock roughly 10 percent + + align:start position:0% +idiosyncratic shock roughly 10 percent + + + align:start position:0% +idiosyncratic shock roughly 10 percent +of it is making its way into consumption + + align:start position:0% +of it is making its way into consumption + + + align:start position:0% +of it is making its way into consumption +which it shouldn't it violates the + + align:start position:0% +which it shouldn't it violates the + + + align:start position:0% +which it shouldn't it violates the +resharing theory but 90 10 of it is + + align:start position:0% +resharing theory but 90 10 of it is + + + align:start position:0% +resharing theory but 90 10 of it is +being pulled away by this Village gift + + align:start position:0% +being pulled away by this Village gift + + + align:start position:0% +being pulled away by this Village gift +giving mechanism + + align:start position:0% +giving mechanism + + + align:start position:0% +giving mechanism +questions + + align:start position:0% + + + + align:start position:0% + +in economics we call this The Smoking + + align:start position:0% +in economics we call this The Smoking + + + align:start position:0% +in economics we call this The Smoking +Gun you kind of theorize a lot you think + + align:start position:0% +Gun you kind of theorize a lot you think + + + align:start position:0% +Gun you kind of theorize a lot you think +you know what happened but what's the + + align:start position:0% +you know what happened but what's the + + + align:start position:0% +you know what happened but what's the +evidence oh they smooth a lot must be + + align:start position:0% +evidence oh they smooth a lot must be + + + align:start position:0% +evidence oh they smooth a lot must be +the gifts okay fine if you think so well + + align:start position:0% +the gifts okay fine if you think so well + + + align:start position:0% +the gifts okay fine if you think so well +here's the evidence they're actually + + align:start position:0% +here's the evidence they're actually + + + align:start position:0% +here's the evidence they're actually +doing it and not only that they openly + + align:start position:0% +doing it and not only that they openly + + + align:start position:0% +doing it and not only that they openly +tell us they're doing it they they are + + align:start position:0% +tell us they're doing it they they are + + + align:start position:0% +tell us they're doing it they they are +very aware that they help each other I I + + align:start position:0% +very aware that they help each other I I + + + align:start position:0% +very aware that they help each other I I +think you might have seen the video by + + align:start position:0% +think you might have seen the video by + + + align:start position:0% +think you might have seen the video by +now my movie so to speak if not take a + + align:start position:0% +now my movie so to speak if not take a + + + align:start position:0% +now my movie so to speak if not take a +look at it because it describes you'll + + align:start position:0% +look at it because it describes you'll + + + align:start position:0% +look at it because it describes you'll +actually see the setting of these Thai + + align:start position:0% +actually see the setting of these Thai + + + align:start position:0% +actually see the setting of these Thai +Villages and how we've gathered the data + + align:start position:0% +Villages and how we've gathered the data + + + align:start position:0% +Villages and how we've gathered the data +and so on Michael is planning to show + + align:start position:0% +and so on Michael is planning to show + + + align:start position:0% +and so on Michael is planning to show +that at one point but it's available + + align:start position:0% +that at one point but it's available + + + align:start position:0% +that at one point but it's available +the 32-minute movie it's not so much of + + align:start position:0% +the 32-minute movie it's not so much of + + + align:start position:0% +the 32-minute movie it's not so much of +a burden + + align:start position:0% +a burden + + + align:start position:0% +a burden +and you'll see how I spend 20 years of + + align:start position:0% +and you'll see how I spend 20 years of + + + align:start position:0% +and you'll see how I spend 20 years of +my life okay + + align:start position:0% +my life okay + + + align:start position:0% +my life okay +so we've talked about this now let's + + align:start position:0% +so we've talked about this now let's + + + align:start position:0% +so we've talked about this now let's +come back to health shocks + + align:start position:0% +come back to health shocks + + + align:start position:0% +come back to health shocks +no it's not covered but it is an illness + + align:start position:0% +no it's not covered but it is an illness + + + align:start position:0% +no it's not covered but it is an illness +experienced by the household and it's + + align:start position:0% +experienced by the household and it's + + + align:start position:0% +experienced by the household and it's +not covered by insurance and the + + align:start position:0% +not covered by insurance and the + + + align:start position:0% +not covered by insurance and the +expenditures go up so this is normalized + + align:start position:0% +expenditures go up so this is normalized + + + align:start position:0% +expenditures go up so this is normalized +so that the event happens here and + + align:start position:0% +so that the event happens here and + + + align:start position:0% +so that the event happens here and +health spending is big and other things + + align:start position:0% +health spending is big and other things + + + align:start position:0% +health spending is big and other things +like they say they're sick they're + + align:start position:0% +like they say they're sick they're + + + align:start position:0% +like they say they're sick they're +reporting symptoms to us we also + + align:start position:0% +reporting symptoms to us we also + + + align:start position:0% +reporting symptoms to us we also +measured that so we're pretty much sure + + align:start position:0% +measured that so we're pretty much sure + + + align:start position:0% +measured that so we're pretty much sure +that we nailed the episode Etc and sick + + align:start position:0% +that we nailed the episode Etc and sick + + + align:start position:0% +that we nailed the episode Etc and sick +days you know it goes up and kind of + + align:start position:0% +days you know it goes up and kind of + + + align:start position:0% +days you know it goes up and kind of +stays up for a while before it comes + + align:start position:0% +stays up for a while before it comes + + + align:start position:0% +stays up for a while before it comes +back down again okay and what happens + + align:start position:0% +back down again okay and what happens + + + align:start position:0% +back down again okay and what happens +there come the gifts + + align:start position:0% +there come the gifts + + + align:start position:0% +there come the gifts +again centered around + + align:start position:0% +again centered around + + + align:start position:0% +again centered around +you know the episode the event as soon + + align:start position:0% +you know the episode the event as soon + + + align:start position:0% +you know the episode the event as soon +as the event happens it's actually minus + + align:start position:0% +as the event happens it's actually minus + + + align:start position:0% +as the event happens it's actually minus +one as soon as the event happens the + + align:start position:0% +one as soon as the event happens the + + + align:start position:0% +one as soon as the event happens the +gifts are positive and statistically + + align:start position:0% +gifts are positive and statistically + + + align:start position:0% +gifts are positive and statistically +different than for households that did + + align:start position:0% +different than for households that did + + + align:start position:0% +different than for households that did +not experience those cell shocks + + align:start position:0% +not experience those cell shocks + + + align:start position:0% +not experience those cell shocks +here we're comparing Placebo households + + align:start position:0% +here we're comparing Placebo households + + + align:start position:0% +here we're comparing Placebo households +if you like which is a dangerous + + align:start position:0% +if you like which is a dangerous + + + align:start position:0% +if you like which is a dangerous +metaphor given the illness part of it + + align:start position:0% +metaphor given the illness part of it + + + align:start position:0% +metaphor given the illness part of it +and the covet we're taking households + + align:start position:0% +and the covet we're taking households + + + align:start position:0% +and the covet we're taking households +pairwise conceptually ones that have + + align:start position:0% +pairwise conceptually ones that have + + + align:start position:0% +pairwise conceptually ones that have +experienced T Cell shocks to ones that + + align:start position:0% +experienced T Cell shocks to ones that + + + align:start position:0% +experienced T Cell shocks to ones that +have not + + align:start position:0% +have not + + + align:start position:0% +have not +and looking at the difference in the + + align:start position:0% +and looking at the difference in the + + + align:start position:0% +and looking at the difference in the +gifts that they get + + align:start position:0% +gifts that they get + + + align:start position:0% +gifts that they get +so if they're sick they're much more + + align:start position:0% +so if they're sick they're much more + + + align:start position:0% +so if they're sick they're much more +likely to be getting gifts than the + + align:start position:0% +likely to be getting gifts than the + + + align:start position:0% +likely to be getting gifts than the +others + + align:start position:0% +others + + + align:start position:0% +others +this is the same setting as what I + + align:start position:0% +this is the same setting as what I + + + align:start position:0% +this is the same setting as what I +showed you when rates of return except + + align:start position:0% +showed you when rates of return except + + + align:start position:0% +showed you when rates of return except +we've changed the subject from shocks to + + align:start position:0% +we've changed the subject from shocks to + + + align:start position:0% +we've changed the subject from shocks to +production to illness shocks now + + align:start position:0% +production to illness shocks now + + + align:start position:0% +production to illness shocks now +actually related they're still producing + + align:start position:0% +actually related they're still producing + + + align:start position:0% +actually related they're still producing +or trying to and the fact that they've + + align:start position:0% +or trying to and the fact that they've + + + align:start position:0% +or trying to and the fact that they've +doubled say their health expenditure is + + align:start position:0% +doubled say their health expenditure is + + + align:start position:0% +doubled say their health expenditure is +a big problem for them because they have + + align:start position:0% +a big problem for them because they have + + + align:start position:0% +a big problem for them because they have +only so much liquidity and they're + + align:start position:0% +only so much liquidity and they're + + + align:start position:0% +only so much liquidity and they're +supposed to be buying inputs and so on + + align:start position:0% +supposed to be buying inputs and so on + + + align:start position:0% +supposed to be buying inputs and so on +to fund their Agriculture and so on so + + align:start position:0% +to fund their Agriculture and so on so + + + align:start position:0% +to fund their Agriculture and so on so +this is a liquidity shock it's not just + + align:start position:0% +this is a liquidity shock it's not just + + + align:start position:0% +this is a liquidity shock it's not just +a health shock in fact sometimes it's an + + align:start position:0% +a health shock in fact sometimes it's an + + + align:start position:0% +a health shock in fact sometimes it's an +elderly person in the household that is + + align:start position:0% +elderly person in the household that is + + + align:start position:0% +elderly person in the household that is +not even contributing to production + + align:start position:0% +not even contributing to production + + + align:start position:0% +not even contributing to production +so we're looking at the economic impact + + align:start position:0% +so we're looking at the economic impact + + + align:start position:0% +so we're looking at the economic impact +of someone taking money away from their + + align:start position:0% +of someone taking money away from their + + + align:start position:0% +of someone taking money away from their +budget essentially + + align:start position:0% +budget essentially + + + align:start position:0% +budget essentially +okay there are various kinds of networks + + align:start position:0% +okay there are various kinds of networks + + + align:start position:0% +okay there are various kinds of networks +in these villages + + align:start position:0% +in these villages + + + align:start position:0% +in these villages +this is the kinship Network who's + + align:start position:0% +this is the kinship Network who's + + + align:start position:0% +this is the kinship Network who's +related to whom this is the financial + + align:start position:0% +related to whom this is the financial + + + align:start position:0% +related to whom this is the financial +Network + + align:start position:0% +Network + + + align:start position:0% +Network +terms of giving gifts to one another + + align:start position:0% +terms of giving gifts to one another + + + align:start position:0% +terms of giving gifts to one another +this is the sales network who they sell + + align:start position:0% +this is the sales network who they sell + + + align:start position:0% +this is the sales network who they sell +to in the village + + align:start position:0% +to in the village + + + align:start position:0% +to in the village +and this is who they hire from + + align:start position:0% +and this is who they hire from + + + align:start position:0% +and this is who they hire from +you know so the way these pictures are + + align:start position:0% +you know so the way these pictures are + + + align:start position:0% +you know so the way these pictures are +produced with the software roughly + + align:start position:0% +produced with the software roughly + + + align:start position:0% +produced with the software roughly +speaking households in the middle you + + align:start position:0% +speaking households in the middle you + + + align:start position:0% +speaking households in the middle you +know are connected to other many other + + align:start position:0% +know are connected to other many other + + + align:start position:0% +know are connected to other many other +households households On The Fringe + + align:start position:0% +households households On The Fringe + + + align:start position:0% +households households On The Fringe +don't have that many connections + + align:start position:0% +don't have that many connections + + + align:start position:0% +don't have that many connections +depending on the variable + + align:start position:0% +depending on the variable + + + align:start position:0% +depending on the variable +and the gift-giving financial network is + + align:start position:0% +and the gift-giving financial network is + + + align:start position:0% +and the gift-giving financial network is +different from the sales and production + + align:start position:0% +different from the sales and production + + + align:start position:0% +different from the sales and production +Network and I'm going to show you what + + align:start position:0% +Network and I'm going to show you what + + + align:start position:0% +Network and I'm going to show you what +happens because of that + + align:start position:0% +happens because of that + + + align:start position:0% +happens because of that +I don't have a slide to show you this + + align:start position:0% +I don't have a slide to show you this + + + align:start position:0% +I don't have a slide to show you this +but if they're in this gift giving + + align:start position:0% +but if they're in this gift giving + + + align:start position:0% +but if they're in this gift giving +Network + + align:start position:0% +Network + + + align:start position:0% +Network +measured by how many times they got + + align:start position:0% +measured by how many times they got + + + align:start position:0% +measured by how many times they got +gifts before the health shock happened + + align:start position:0% +gifts before the health shock happened + + + align:start position:0% +gifts before the health shock happened +then most of the impact of the shock is + + align:start position:0% +then most of the impact of the shock is + + + align:start position:0% +then most of the impact of the shock is +covered by incoming gifts + + align:start position:0% +covered by incoming gifts + + + align:start position:0% +covered by incoming gifts +but what do we have in the U.S you know + + align:start position:0% +but what do we have in the U.S you know + + + align:start position:0% +but what do we have in the U.S you know +this is an issue a household gets sick + + align:start position:0% +this is an issue a household gets sick + + + align:start position:0% +this is an issue a household gets sick +is the government going to be able to + + align:start position:0% +is the government going to be able to + + + align:start position:0% +is the government going to be able to +help them + + align:start position:0% +help them + + + align:start position:0% +help them +we have these PPP paycheck protection + + align:start position:0% +we have these PPP paycheck protection + + + align:start position:0% +we have these PPP paycheck protection +programs and so on + + align:start position:0% +programs and so on + + + align:start position:0% +programs and so on +our relatives helping probably so we + + align:start position:0% +our relatives helping probably so we + + + align:start position:0% +our relatives helping probably so we +don't know the extent of it it's not + + align:start position:0% +don't know the extent of it it's not + + + align:start position:0% +don't know the extent of it it's not +measured we tend to think households are + + align:start position:0% +measured we tend to think households are + + + align:start position:0% +measured we tend to think households are +our Standalone they're vulnerable + + align:start position:0% +our Standalone they're vulnerable + + + align:start position:0% +our Standalone they're vulnerable +households running businesses in + + align:start position:0% +households running businesses in + + + align:start position:0% +households running businesses in +particular get a liquidity shock and + + align:start position:0% +particular get a liquidity shock and + + + align:start position:0% +particular get a liquidity shock and +mainly they don't have sales with covet + + align:start position:0% +mainly they don't have sales with covet + + + align:start position:0% +mainly they don't have sales with covet +or their employees aren't you know able + + align:start position:0% +or their employees aren't you know able + + + align:start position:0% +or their employees aren't you know able +to work + + align:start position:0% +to work + + + align:start position:0% +to work +so they're not generating Revenue + + align:start position:0% +so they're not generating Revenue + + + align:start position:0% +so they're not generating Revenue +well if it were covered with gifts as it + + align:start position:0% +well if it were covered with gifts as it + + + align:start position:0% +well if it were covered with gifts as it +is for some people in Thailand then they + + align:start position:0% +is for some people in Thailand then they + + + align:start position:0% +is for some people in Thailand then they +pool that risk away + + align:start position:0% +pool that risk away + + + align:start position:0% +pool that risk away +great system + + align:start position:0% +great system + + + align:start position:0% +great system +if they're not there are other + + align:start position:0% +if they're not there are other + + + align:start position:0% +if they're not there are other +consequences + + align:start position:0% +consequences + + + align:start position:0% +consequences +so in particular + + align:start position:0% +so in particular + + + align:start position:0% +so in particular +we can look at who's connected to whom + + align:start position:0% +we can look at who's connected to whom + + + align:start position:0% +we can look at who's connected to whom +in terms of the network + + align:start position:0% +in terms of the network + + + align:start position:0% +in terms of the network +households who experience shocks and + + align:start position:0% +households who experience shocks and + + + align:start position:0% +households who experience shocks and +were selling to other households their + + align:start position:0% +were selling to other households their + + + align:start position:0% +were selling to other households their +sales go down + + align:start position:0% +sales go down + + + align:start position:0% +sales go down +it's a bit counterintuitive because you + + align:start position:0% +it's a bit counterintuitive because you + + + align:start position:0% +it's a bit counterintuitive because you +would think they would want the money + + align:start position:0% +would think they would want the money + + + align:start position:0% +would think they would want the money +from the sales + + align:start position:0% +from the sales + + + align:start position:0% +from the sales +but the problem is they had to reduce + + align:start position:0% +but the problem is they had to reduce + + + align:start position:0% +but the problem is they had to reduce +the inputs they had the scale production + + align:start position:0% +the inputs they had the scale production + + + align:start position:0% +the inputs they had the scale production +down and so they have less Revenue as a + + align:start position:0% +down and so they have less Revenue as a + + + align:start position:0% +down and so they have less Revenue as a +result + + align:start position:0% +result + + + align:start position:0% +result +sales are down inventories are up + + align:start position:0% +sales are down inventories are up + + + align:start position:0% +sales are down inventories are up +well I should let me come back and + + align:start position:0% +well I should let me come back and + + + align:start position:0% +well I should let me come back and +clarify these are + + align:start position:0% +clarify these are + + + align:start position:0% +clarify these are +households connected to the household + + align:start position:0% +households connected to the household + + + align:start position:0% +households connected to the household +that has experienced the shock + + align:start position:0% +that has experienced the shock + + + align:start position:0% +that has experienced the shock +these guys were selling I said it wrong + + align:start position:0% +these guys were selling I said it wrong + + + align:start position:0% +these guys were selling I said it wrong +I'm sorry these guys were selling + + align:start position:0% +I'm sorry these guys were selling + + + align:start position:0% +I'm sorry these guys were selling +Revenue to the household that had the + + align:start position:0% +Revenue to the household that had the + + + align:start position:0% +Revenue to the household that had the +shock now they sell less likewise + + align:start position:0% +shock now they sell less likewise + + + align:start position:0% +shock now they sell less likewise +because they sell less they're + + align:start position:0% +because they sell less they're + + + align:start position:0% +because they sell less they're +accumulating inventory and they're + + align:start position:0% +accumulating inventory and they're + + + align:start position:0% +accumulating inventory and they're +holding on to inventory longer this is + + align:start position:0% +holding on to inventory longer this is + + + align:start position:0% +holding on to inventory longer this is +for this inventory turnover ratio + + align:start position:0% +for this inventory turnover ratio + + + align:start position:0% +for this inventory turnover ratio +it's a measure of and when it's high + + align:start position:0% +it's a measure of and when it's high + + + align:start position:0% +it's a measure of and when it's high +it's a measure of inefficiency it's also + + align:start position:0% +it's a measure of inefficiency it's also + + + align:start position:0% +it's a measure of inefficiency it's also +negative with an adverse effect + + align:start position:0% +negative with an adverse effect + + + align:start position:0% +negative with an adverse effect +we do this for all the shocks and do it + + align:start position:0% +we do this for all the shocks and do it + + + align:start position:0% +we do this for all the shocks and do it +for the large shock so now we see the + + align:start position:0% +for the large shock so now we see the + + + align:start position:0% +for the large shock so now we see the +covet connection right which is you know + + align:start position:0% +covet connection right which is you know + + + align:start position:0% +covet connection right which is you know +a household experiences expenses + + align:start position:0% +a household experiences expenses + + + align:start position:0% +a household experiences expenses +associated with the illness even if it's + + align:start position:0% +associated with the illness even if it's + + + align:start position:0% +associated with the illness even if it's +not a working member how do they cover + + align:start position:0% +not a working member how do they cover + + + align:start position:0% +not a working member how do they cover +those expenses they they try to cut back + + align:start position:0% +those expenses they they try to cut back + + + align:start position:0% +those expenses they they try to cut back +they cut back on spending in these + + align:start position:0% +they cut back on spending in these + + + align:start position:0% +they cut back on spending in these +Village economies businesses are + + align:start position:0% +Village economies businesses are + + + align:start position:0% +Village economies businesses are +connected + + align:start position:0% +connected + + + align:start position:0% +connected +they're buying and selling inputs from + + align:start position:0% +they're buying and selling inputs from + + + align:start position:0% +they're buying and selling inputs from +one another and selling output so if + + align:start position:0% +one another and selling output so if + + + align:start position:0% +one another and selling output so if +they have to cut back and they don't + + align:start position:0% +they have to cut back and they don't + + + align:start position:0% +they have to cut back and they don't +have the revenue that they had before + + align:start position:0% +have the revenue that they had before + + + align:start position:0% +have the revenue that they had before +the people who had been buying have been + + align:start position:0% +the people who had been buying have been + + + align:start position:0% +the people who had been buying have been +selling to them you know no longer have + + align:start position:0% +selling to them you know no longer have + + + align:start position:0% +selling to them you know no longer have +the sales just like you know one + + align:start position:0% +the sales just like you know one + + + align:start position:0% +the sales just like you know one +business is connected to another they + + align:start position:0% +business is connected to another they + + + align:start position:0% +business is connected to another they +all go down the supply chain because + + align:start position:0% +all go down the supply chain because + + + align:start position:0% +all go down the supply chain because +they're connected we had a lecture at + + align:start position:0% +they're connected we had a lecture at + + + align:start position:0% +they're connected we had a lecture at +the end on interconnections among + + align:start position:0% +the end on interconnections among + + + align:start position:0% +the end on interconnections among +households we did leonte up we did the + + align:start position:0% +households we did leonte up we did the + + + align:start position:0% +households we did leonte up we did the +input output Matrix I showed you + + align:start position:0% +input output Matrix I showed you + + + align:start position:0% +input output Matrix I showed you +fukujima Shima and the effect of the + + align:start position:0% +fukujima Shima and the effect of the + + + align:start position:0% +fukujima Shima and the effect of the +earthquake there and those were all + + align:start position:0% +earthquake there and those were all + + + align:start position:0% +earthquake there and those were all +Supply chains you know one sector is + + align:start position:0% +Supply chains you know one sector is + + + align:start position:0% +Supply chains you know one sector is +connected to another one firms connected + + align:start position:0% +connected to another one firms connected + + + align:start position:0% +connected to another one firms connected +to another these Thai households are + + align:start position:0% +to another these Thai households are + + + align:start position:0% +to another these Thai households are +connected to another and the more the + + align:start position:0% +connected to another and the more the + + + align:start position:0% +connected to another and the more the +point of this I guess I haven't said + + align:start position:0% +point of this I guess I haven't said + + + align:start position:0% +point of this I guess I haven't said +that is yet the closer they are to the + + align:start position:0% +that is yet the closer they are to the + + + align:start position:0% +that is yet the closer they are to the +adversely impacted household the more + + align:start position:0% +adversely impacted household the more + + + align:start position:0% +adversely impacted household the more +they suffer so you think networks are a + + align:start position:0% +they suffer so you think networks are a + + + align:start position:0% +they suffer so you think networks are a +good thing networks are a good thing + + align:start position:0% +good thing networks are a good thing + + + align:start position:0% +good thing networks are a good thing +when it comes to financial gift giving + + align:start position:0% +when it comes to financial gift giving + + + align:start position:0% +when it comes to financial gift giving +but if gift giving doesn't cover the + + align:start position:0% +but if gift giving doesn't cover the + + + align:start position:0% +but if gift giving doesn't cover the +adverse shock we're actually getting an + + align:start position:0% +adverse shock we're actually getting an + + + align:start position:0% +adverse shock we're actually getting an +amplification in this economy that's + + align:start position:0% +amplification in this economy that's + + + align:start position:0% +amplification in this economy that's +showing up in terms of lost wages and + + align:start position:0% +showing up in terms of lost wages and + + + align:start position:0% +showing up in terms of lost wages and +less production unless sales and finally + + align:start position:0% +less production unless sales and finally + + + align:start position:0% +less production unless sales and finally +this distinction which I've been pushing + + align:start position:0% +this distinction which I've been pushing + + + align:start position:0% +this distinction which I've been pushing +today about Aggregate and idiosyncratic + + align:start position:0% +today about Aggregate and idiosyncratic + + + align:start position:0% +today about Aggregate and idiosyncratic +shocks + + align:start position:0% +shocks + + + align:start position:0% +shocks +go to one of the areas where they have + + align:start position:0% +go to one of the areas where they have + + + align:start position:0% +go to one of the areas where they have +fish ponds shrimp ponds in particular + + align:start position:0% +fish ponds shrimp ponds in particular + + + align:start position:0% +fish ponds shrimp ponds in particular +and it's pretty polluted and they didn't + + align:start position:0% +and it's pretty polluted and they didn't + + + align:start position:0% +and it's pretty polluted and they didn't +have you know Green agriculture so to + + align:start position:0% +have you know Green agriculture so to + + + align:start position:0% +have you know Green agriculture so to +speak and the EU put a ban on the shrimp + + align:start position:0% +speak and the EU put a ban on the shrimp + + + align:start position:0% +speak and the EU put a ban on the shrimp +by the way if you go to Walmart you know + + align:start position:0% +by the way if you go to Walmart you know + + + align:start position:0% +by the way if you go to Walmart you know +you say villagers who cares well anyway + + align:start position:0% +you say villagers who cares well anyway + + + align:start position:0% +you say villagers who cares well anyway +they produce the shrimp that you buy in + + align:start position:0% +they produce the shrimp that you buy in + + + align:start position:0% +they produce the shrimp that you buy in +Walmart but the EU put a ban + + align:start position:0% +Walmart but the EU put a ban + + + align:start position:0% +Walmart but the EU put a ban +on the on the shrimp because they say it + + align:start position:0% +on the on the shrimp because they say it + + + align:start position:0% +on the on the shrimp because they say it +wasn't clean which it wasn't now the + + align:start position:0% +wasn't clean which it wasn't now the + + + align:start position:0% +wasn't clean which it wasn't now the +point is most but not all households are + + align:start position:0% +point is most but not all households are + + + align:start position:0% +point is most but not all households are +doing those shrimp ponds and the ban is + + align:start position:0% +doing those shrimp ponds and the ban is + + + align:start position:0% +doing those shrimp ponds and the ban is +like an aggregate shock so we can + + align:start position:0% +like an aggregate shock so we can + + + align:start position:0% +like an aggregate shock so we can +compare the aggregate shock which is + + align:start position:0% +compare the aggregate shock which is + + + align:start position:0% +compare the aggregate shock which is +most of the households to the + + align:start position:0% +most of the households to the + + + align:start position:0% +most of the households to the +idiosyncratic illness shocks and you can + + align:start position:0% +idiosyncratic illness shocks and you can + + + align:start position:0% +idiosyncratic illness shocks and you can +see that although gifts go up I already + + align:start position:0% +see that although gifts go up I already + + + align:start position:0% +see that although gifts go up I already +showed you that for the idiosyncratic + + align:start position:0% +showed you that for the idiosyncratic + + + align:start position:0% +showed you that for the idiosyncratic +shocks including in this Village there's + + align:start position:0% +shocks including in this Village there's + + + align:start position:0% +shocks including in this Village there's +not that clear picture when it comes to + + align:start position:0% +not that clear picture when it comes to + + + align:start position:0% +not that clear picture when it comes to +the trim shock because it's an aggregate + + align:start position:0% +the trim shock because it's an aggregate + + + align:start position:0% +the trim shock because it's an aggregate +shock there's not a lot of weight excuse + + align:start position:0% +shock there's not a lot of weight excuse + + + align:start position:0% +shock there's not a lot of weight excuse +me to reallocate that risk + + align:start position:0% +me to reallocate that risk + + + align:start position:0% +me to reallocate that risk +and this is the associated decline in + + align:start position:0% +and this is the associated decline in + + + align:start position:0% +and this is the associated decline in +employment which is bigger under the + + align:start position:0% +employment which is bigger under the + + + align:start position:0% +employment which is bigger under the +aggregate shock + + align:start position:0% +aggregate shock + + + align:start position:0% +aggregate shock +okay + + align:start position:0% +okay + + + align:start position:0% +okay +questions + + align:start position:0% + + + + align:start position:0% + +okay so that's what I have for today and + + align:start position:0% +okay so that's what I have for today and + + + align:start position:0% +okay so that's what I have for today and +we'll continue on Thursday thank you for + + align:start position:0% +we'll continue on Thursday thank you for + + + align:start position:0% +we'll continue on Thursday thank you for +coming today talk to you soon \ No newline at end of file diff --git a/RUz-DJz3--I.txt b/RUz-DJz3--I.txt new file mode 100644 index 0000000000000000000000000000000000000000..69f2040e12cc8407c69be9984c5ae39d01c5521e --- /dev/null +++ b/RUz-DJz3--I.txt @@ -0,0 +1,2030 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: So. + +In the meantime, you've started +looking at two phase + +equilibrium. + +So now we're starting +to look at mixtures. + +And so now we have more +than one constituent. + +And we have more than +one phase present. + +Right? + +So you've started to look at +things that look like this, + +where you've got, let's +say, two components. + +Both in the gas phase. + +And now to try to figure +out what the phase + +equilibria look like. + +Of course it's now a little bit +more complicated than what + +you went through before, where +you can get pressure + +temperature phase diagrams with +just a single component. + +Now we want to worry about +what's the composition. + +Of each of the components. + +In each of the phases. + +And what's the temperature +and the pressure. + +Total and partial pressures +and all of that. + +So you can really figure out +everything about both phases. + +And there are all sorts of +important reasons to do that, + +obviously lots of chemistry +happens in liquid mixtures. + +Some in gas mixtures. + +Some where they're +in equilibrium. + +All sorts of chemical +processes. + +Distillation, for example, +takes advantage of the + +properties of liquid +and gas mixtures. + +Where one of them might be +richer, will be richer, and + +the more volatile of +the components. + +That can be used as a basis +for purification. + +You mix ethanol and water +together so you've got a + +liquid with a certain +composition of each. + +The gas is going to be richer +and the more volatile of the + +two, the ethanol. + +So in a distillation, where you +put things up in the gas, + +more of the ethanol comes up. + +You could then collect +that gas, right? + +And re-condense it, and +make a new liquid. + +Which is much richer in ethanol +than the original + +liquid was. + +Then you could make, then you +could put some of them up into + +the gas phase. + +Where it will be still +richer in ethanol. + +And then you could collect that +and repeat the process. + +So the point is that properties +of liquid gas, + +two-component or multi-component +mixtures like + +this can be exploited. + +Basically, the different +volatilities of the different + +components can be exploited for +things like purification. + +Also if you want to calculate +chemical equilibria in the + +liquid and gas phase, of +course, now you've seen + +chemical equilibrium, so the +amount of reaction depends on + +the composition. + +So of course if you want +reactions to go, then this + +also can be exploited by looking +at which phase might + +be richer in one reactant +or another. + +And thereby pushing the +equilibrium toward one + +direction or the other. + +OK. + +So. we've got some total +temperature and pressure. + +And we have compositions. + +So in the gas phase, we've got +mole fractions yA and yB. + +In the liquid phase we've got +mole fractions xA and xB. + +So that's our system. + +One of the things that you +established last time is that, + +so there are the total number +of variables including the + +temperature and the pressure. + +And let's say the mole fraction +of A in each of the + +liquid and gas phases, right? + +But then there are +constraints. + +Because the chemical +potentials have + +to be equal, right? + +Chemical potential of +A has to be equal in + +the liquid and gas. + +Same with B. Those two +constraints reduce the number + +of independent variables. + +So there'll be two in this +case rather than four + +independent variables. + +If you control those, then +everything else will follow. + +What that means is if you've got +a, if you control, if you + +fix the temperature and the +total pressure, everything + +else should be determinable. + +No more free variables. + +And then, what you saw is that +in simple or ideal liquid + +mixtures, a result called +Raoult's law would hold. + +Which just says that the partial +pressure of A is equal + +to the mole fraction of A in the +liquid times the pressure + +of pure A over the liquid. + +And so what this gives +you is a diagram + +that looks like this. + +If we plot this versus xB, this +is mole fraction of B in + +the liquid going from +zero to one. + +Then we could construct a +diagram of this sort. + +So this is the total pressure +of A and B. The partial + +pressures are given +by these lines. + +So this is our pA star +and pB star. + +The pressures over the pure +liquid A and B at the limits + +of mole fraction of B +being zero and one. + +So in this situation, for +example, A is the more + +volatile of the components. + +So it's partial pressure +over its pure liquid. + +At this temperature. + +Is higher than the partial +pressure of B + +over its pure liquid. + +A would be the ethanol, for +example and B the water in + +that mixture. + +OK. + +Then you started looking at both +the gas and the liquid + +phase in the same diagram. + +So this is the mole fraction +of the liquid. + +If you look and see, well, OK +now we should be able to + +determine the mole fraction +in the gas as well. + +Again, if we note total +temperature and pressure, + +everything else must follow. + +And so, you saw this +worked out. + +Relation between p and +yA, for example. + +The result was p is pA star +times pB star over pA star + +plus pB star minus +pA star times yA. + +And the point here is that +unlike this case, where you + +have a linear relationship, the +relationship between the + +pressure and the liquid mole +fraction isn't linear. + +We can still plot +it, of course. + +So if we do that, then we end +up with a diagram that looks + +like the following. + +Now I'm going to keep both mole +fractions, xB and yB, + +I've got some total pressure. + +I still have my linear +relationship. + +And then I have a non-linear +relationship between the + +pressure and the mole fraction +in the gas phase. + +So let's just fill this in. + +Here is pA star still. + +Here's pB star. + +Of course, at the limits they're +still, both mole + +fractions they're zero and one. + +OK. + +I believe this is this is where +you ended up at the end + +of the last lecture. + +But it's probably not so clear +exactly how you read + +something like this. + +And use it. + +It's extremely useful. + +You just have to kind of learn +how to follow what happens in + +a diagram like this. + +And that's what I want to spend +some of today doing. + +Is just, walking through what's +happening physically, + +with a container with a +mixture of the two. + +And how does that correspond +to what gets read off the + +diagram under different +conditions. + +So. + +Let's just start somewhere on +a phase diagram like this. + +Let's start up here at some +point one, so we're in the + +pure - well, not pure, you're +in the all liquid phase. + +It's still a mixture. + +It's not a pure substance. +pA star, pB star. + +There's the gas phase. + +So, if we start at one, and now + +there's some total pressure. + +And now we're going +to reduce it. + +What happens? + +We start with a pure - with +an all-liquid mixture. + +No gas. + +And now we're going to bring +down the pressure. + +Allowing some of the liquid to +go up into the gas phase. + +So, we can do that. + +And once we reach point +two, then we find + +a coexistence curve. + +Now the liquid and gas +are going to coexist. + +So this is the liquid phase. + +And that means that +this must be xB. + +And it's xB at one, but it's +also xB at two, and I want to + +emphasize that. + +So let's put our pressure +for two. + +And if we go over here, this is +telling us about the mole + +fraction in the gas phase. + +That's what these curves +are, remember. + +So this is the one that's +showing us the mole fraction + +in the liquid phase. + +This nonlinear one +in the gas phase. + +So that means just reading off +it, this is xB, that's the + +liquid mole fraction. + +Here's yB. + +The gas mole fraction. + +They're not the same, right, +because of course the + +components have different +volatility. + +A's more volatile. + +So that means that the mole +fraction of B in the liquid + +phase is higher than the +mole fraction of + +B in the gas phase. + +Because A is the more +volatile component. + +So more, relatively more, of A, +the mole fraction of A is + +going to be higher up +in the gas phase. + +Which means the mole +fraction of B is + +lower in the gas phase. + +So, yB less than xB if +A is more volatile. + +OK, so now what's happening +physically? + +Well, we started at a +point where we only + +had the liquid present. + +So at our initial pressure, +we just have all liquid. + +There's some xB at one. + +That's all there is, there +isn't any gas yet. + +Now, what happened here? + +Well, now we lowered +the pressure. + +So you could imagine, well, +we made the box bigger. + +Now, if the liquid was under +pressure, being squeezed by + +the box, right then you +could make the box + +a little bit bigger. + +And there's still no gas. + +That's moving down like this. + +But then you get to a point +where there's just barely any + +pressure on top of the liquid. + +And then you keep expanding +the box. + +Now some gas is going to form. + +So now we're going to +go to our case two. + +We've got a bigger box. + +And now, right around +where this was, this + +is going to be liquid. + +And there's gas up here. + +So up here is yB at +pressure two. + +Here's xB at pressure two. + +Liquid and gas. + +So that's where we are +at point two here. + +Now, what happens if +we keep going? + +Let's lower the pressure +some more. + +Well, we can lower +it and do this. + +But really if we want to see +what's happening in each of + +the phases, we have to stay +on the coexistence curves. + +Those are what tell us what +the pressures are. + +What the partial pressure +are going to be + +in each of the phases. + +In each of the two, in the +liquid and the gas phases. + +So let's say we lower the +pressure a little more. + +What's going to happen +is, then we'll end up + +somewhere over here. + +In the liquid, and that'll +correspond to something over + +here in the gas. + +So here's three. + +So now we're going to have, +that's going to be xB at + +pressure three. + +And over here is going to +be yB at pressure three. + +And all we've done, of +course, is we've just + +expanded this further. + +So now we've got a +still taller box. + +And the liquid is going to be a +little lower because some of + +it has evaporated, formed +the gas phase. + +So here's xB at three. + +Here's yB at three, here's +our gas phase. + +Now we could decrease +even further. + +And this is the sort of +thing that you maybe + +can't do in real life. + +But I can do on a blackboard. + +I'm going to give myself more +room on this curve, to finish + +this illustration. + +There. + +Beautiful. + +So now we can lower a little bit +further, and what I want + +to illustrate is, if we keep +going down, eventually we get + +to a pressure where now if we +look over in the gas phase, + +we're at the same pressure, +mole fraction that we had + +originally in the +liquid phase. + +So let's make four even +lower pressure. + +What does that mean? + +What it means is, we're +running out of liquid. + +So what's supposed to +happen is A is the + +more volatile component. + +So as we start opening up some +room for gas to form, you get + +more of A in the gas phase. + +But of course, and the liquid is +richer in B. But of course, + +eventually you run +out of liquid. + +You make the box pretty big, and +you run out, or you have + +the very last drop of liquid. + +So what's the mole fraction +of B in the gas phase? + +It has to be the same as +what it started in + +in the liquid phase. + +Because after all the total +number of moles of A and B + +hasn't changed any. + +So if you take them all from the +liquid and put them all up + +into the gas phase, it +must be the same. + +So yB of four. + +Once you just have +the last drop. + +So then yB of four is basically +equal to xB of one. + +Because everything's now +up in the gas phase. + +So in principle, there's still +a tiny, tiny bit of xB at + +pressure four. + +Well, we could keep lowering +the pressure. + +We could make the box +a little bigger. + +Then the very last of the liquid +is going to be gone. + +And what'll happen then +is, we're all here. + +There's no more liquid. + +We're not going down on the +coexistence curve any more. + +We don't have a liquid gas +coexistence any more. + +We just have a gas phase. + +Of course, we can continue +to lower the pressure. + +And then what we're doing +is just going down here. + +So there's five. + +And five is the same as +this only bigger. + +And so forth. + +OK, any questions about +how this works? + +It's really important to just +gain facility in reading these + +things and seeing, OK, what is +it that this is telling you. + +And you can see it's not +complicated to do it, but it + +takes a little bit of practice. + +OK. + +Now, of course, we could do +exactly the same thing + +starting from the gas phase. + +And raising the pressure. + +And although you may anticipate +that it's kind of + +pedantic, I really do want to +illustrate something by it. + +So let me just imagine that +we're going to do that. + +Let's start all in +the gas phase. + +Up here's the liquid. +pA star, pB star. + +And now let's start +somewhere here. + +So we're down somewhere in +the gas phase with some + +composition. + +So it's the same story, except +now we're starting here. + +It's all gas. + +And we're going to +start squeezing. + +We're increasing the pressure. + +And eventually here's one, will +reach two, so of course + +here's our yB. + +We started with all +gas, no liquid. + +So this is yB of one. + +It's the same as yB of two, I'm +just raising the pressure + +enough to just reach the +coexistence curve. + +And of course, out here tells +us xB of two, right? + +So what is it saying? + +We've squeezed and started +to form some liquid. + +And the liquid is richer in +component B. Maybe it's + +ethanol water again. + +And we squeeze, and now we've +got more water in the liquid + +phase than in the gas phase. + +Because water's the less +volatile component. + +It's what's going to +condense first. + +So the liquid is rich in the +less volatile of the + +components. + +Now, obviously, we can continue +in doing exactly the + +reverse of what I showed you. + +But all I want to really +illustrate is, this is a + +strategy for purification of the +less volatile component. + +Once you've done this, well now +you've got some liquid. + +Now you could collect that +liquid in a separate vessel. + +So let's collect the liquid +mixture with xB of two. + +So it's got some mole fraction +of B. So we've purified that. + +But now we're going to start, +we've got pure liquid. + +Now let's make the vessel big. + +So it all goes into +the gas phase. + +Then lower p. + +All gas. + +So we start with yB of three, +which equals xB of two. + +In other words, it's the +same mole fraction. + +So let's reconstruct that. + +So here's p of two. + +And now we're going to go +to some new pressure. + +And the point is, now we're +going to start, since the mole + +fraction in the gas phase that +we're starting from is the + +same number as this was. + +So it's around here somewhere. + +That's yB of three +equals xB of two. + +And we're down here. + +In other words, all we've done +is make the container big + +enough so the pressure's low and +it's all in the gas phase. + +That's all we have, +is the gas. + +But the composition is whatever +the composition is + +that we extracted here +from the liquid. + +So this xB, which is the liquid +mole fraction, is now + +yB, the gas mole fraction. + +Of course, the pressure +is different. + +Lower than it was before. + +Great. + +Now let's increase. + +So here's three. + +And now let's increase +the pressure to four. + +And of course what happens, +now we've got coexistence. + +So here's liquid. + +Here's gas. + +So, now we're over here again. + +There's xB at pressure four. + +Pure still in component B. We +can repeat the same procedure. + +Collect it. + +All liquid, put it +in a new vessel. + +Expand it, lower the pressure, +all goes back + +into the gas phase. + +Do it all again. + +And the point is, what you're +doing is walking along here. + +Here to here. + +Then you start down here, and +go from here to here. + +From here to here. + +And you can purify. + +Now, of course, the optimal +procedure, you have to think a + +little bit. + +Because if you really do +precisely what I said, you're + +going to have a mighty little +bit of material + +each time you do that. + +So yes it'll be the little bit +you've gotten at the end is + +going to be really pure, but +there's not a whole lot of it. + +Because, remember, what we +said is let's raise the + +pressure until we just +start being on + +the coexistence curve. + +So we've still got mostly gas. + +Little bit of liquid. + +Now, I could raise the pressure +a bit higher. + +So that in the interest of +having more of the liquid, + +when I do that, though, the +liquid that I have at this + +higher pressure won't be as +enriched as it was down here. + +Now, I could still do +this procedure. + +I could just do more of them. + +So it takes a little bit of +judiciousness to figure out + +how to optimize that. + +In the end, though, you can +continue to walk your way down + +through these coexistence curves +and purify repeatedly + +the component B, the less +volatile of them, and end up + +with some amount of it. + +And there'll be some balance +between the amount that you + +feel like you need to end +up with and how pure + +you need it to be. + +Any questions about +how this works? + +So purification of less +volatile components. + +Now, how much of each of +these quantities in + +each of these phases? + +So, pertinent to this +discussion, of course we need + +to know that. + +If you want to try to optimize +a procedure like that, of + +course it's going to be +crucial to be able to + +understand and calculate for any +pressure that you decide + +to raise to, just how many moles +do you have in each of + +the phases? + +So at the end of the day, you +can figure out, OK, now when I + +reach a certain degree of +purification, here's how much + +of the stuff I end up with. + +Well, that turns out +to be reasonably + +straightforward to do. + +And so what I'll go through +is a simple mathematical + +derivation. + +And it turns out that it allows +you to just read right + +off the diagram how much of each +material you're going to + +end up with. + +So, here's what happens. + +This is something called +the lever rule. + +How much of each component +is there in each phase? + +So let's consider a +case like this. + +Let me draw yet once again, +just to get the numbering + +consistent. + +With how we'll treat this. + +So we're going to start here. + +And I want to draw it right +in the middle, so I've + +got plenty of room. + +And we're going to go +up to some pressure. + +And somewhere out there, +now I can go to + +my coexistence curves. + +Liquid. + +And gas. + +And I can read off my values. + +So this is the liquid xB. + +So I'm going to go up to some +point two, here's xB of two. + +Here's yB of two. + +Great. + +Now let's get these +written in. + +So let's just define terms +a little bit. nA, nB. + +Or just our total number of +moles. ng and n liquid, of + +course, total number of moles. + +In the gas and liquid phases. + +So let's just do the calculation +for each + +of these two cases. + +We'll start with one. + +That's the easier case. + +Because then we have +only the gas. + +So at one, all gas. + +It says pure gas in the notes, +but of course that + +isn't the pure gas. + +It's the mixture of the +two components. + +So. + +How many moles of A? + +Well it's the mole fraction +of A in the gas. + +Times the total number +of moles in the gas. + +Let me put one in here. + +Just to be clear. + +And since we have all gas, the +number of moles in the gas is + +just the total number +of moles. + +So this is just yA at +one times n total. + +Let's just write that in. + +And of course n total is +equal to nA plus nB. + +So now let's look at +condition two. + +Now we have to look a little +more carefully. + +Because we have a liquid +gas mixture. + +So nA is equal to yA +at pressure two. + +Times the number of moles +of gas at pressure two. + +Plus xA, at pressure two, times +the number of moles of + +liquid at pressure two. + +Now, of course, these things +have to be equal. + +The total number of moles of +A didn't change, right? + +So those are equal. + +Then yA of two times +ng of two. + +Plus xA of two times n liquid of +two, that's equal to yA of + +one times n total. + +Which is of course equal to yA +of one times n gas at two plus + +n liquid at two. + +I suppose I could be, +add that equality. + +Of course, it's an +obvious one. + +But let me do it anyway. + +The total number of moles +is equal to nA plus nB. + +But it's also equal to +n liquid plus n gas. + +And that's all I'm taking +advantage of here. + +And now I'm just going to +rearrange the terms. + +So I'm going to write yA at one +minus yA at two, times ng + +at two, is equal to, and I'm +going to take the other terms, + +the xA term. xA of two +minus yA of one + +times n liquid at two. + +So I've just rearranged +the terms. + +And I've done that because +now, I think I omitted + +something here. yA +of one times ng. + +No, I forgot a bracket, is what +I did. yA of one there. + +And I did this because now I +want to do is look at the + +ratio of liquid to gas +at pressure two. + +So, ratio of I'll put it gas +to liquid, that's ng of two + +over n liquid at two. + +And that's just equal to xA of +two minus yA at one minus yA + +at one minus yA at two. + +So what does it mean? + +It's the ratio of these +lever arms. + +That's what it's telling me. + +I can look, so I raise the +pressure up to two. + +And so here's xB at two, +here's yB at two. + +And I'm here somewhere. + +And this little amount and this +little amount, that's + +that difference. + +And it's just telling me that +ratio of those arms is the + +ratio of the total number of +moles of gas to liquid. + +And that's great. + +Because now when I go back to +the problem that we were just + +looking at, where I say, well +I'm going to purify the less + +volatile component by raising +the pressure until I'm at + +coexistence starting +in the gas phase. + +Raise the pressure, I've +got some liquid. + +But I also want some finite +amount of liquid. + +But I don't want to just, when +I get the very, very first + +drop of liquid now collected, of +course it's enriched in the + +less volatile component. + +But there may be a minuscule +amount, right? + +So I'll raise the pressure +a bit more. + +I'll go up in pressure. + +And now, of course, when I do +that the amount of enrichment + +of the liquid isn't as big as it +was if I just raised it up + +enough to barely have +any liquid. + +Then I'd be out here. + +But I've got more material in +the liquid phase to collect. + +And that's what this allows +me to calculate. + +Is how much do I +get in the end. + +So it's very handy. + +You can also see, if I go all +the way to the limit where the + +mole fraction in the liquid at +the end is equal to what it + +was in the gas when I started, +what that says is that there's + +no more gas left any more. + +In other words, these two +things are equal. + +If I go all the way to the point +where I've got all the, + +this is the amount I started +with, in the pure gas phase, + +now I keep raising +it all the way. + +Until I've got the same mole +fraction in the liquid. + +Of course, we know what +that really means. + +That means that I've gone +all the way from + +pure gas to pure liquid. + +And the mole fraction in that +case has to be the same. + +And what this is just telling +us mathematically is, when + +that happens this is zero. + +That means I don't have +any gas left. + +Yeah. + +STUDENT: [INAUDIBLE] + +PROFESSOR: No. + +Because, so it's the mole +fraction in the gas phase. + +But you've started with some +amount that it's only going to + +go down from there. + +STUDENT: [INAUDIBLE] + +PROFESSOR: Yeah. + +Yeah. + +Any other questions? + +OK. + +Well, now what I want to do +is just put up a slightly + +different kind of diagram, but +different in an important way. + +Namely, instead of showing the +mole fractions as a function + +of the pressure. + +And I haven't written it in, +but all of these are at + +constant temperature, right? + +I've assumed the temperature +is constant + +in all these things. + +Now let's consider the other +possibility, the other simple + +possibility, which is, let's +hold the pressure constant and + +vary the temperature. + +Of course, you know in the lab, +that's usually what's + +easiest to do. + +Now, unfortunately, the +arithmetic gets more + +complicated. + +It's not monumentally +complicated, but here in this + +case, where you have one linear +relationship, which is + +very convenient. + +From Raoult's law. + +And then you have one non-linear +relationship there + +for the mole fraction +of the gas. + +In the case of temperature, +they're both, + +neither one is linear. + +Nevertheless, we can just +sketch what the + +diagram looks like. + +And of course it's very useful +to do that, and see how to + +read off it. + +And I should say the derivation +of the curves isn't + +particularly complicated. + +It's not particularly more +complicated than what I think + +you saw last time +to derive this. + +There's no complicated +math involved. + +But the point is, the derivation +doesn't yield a + +linear relationship for either +the gas or the liquid part of + +the coexistence curve. + +OK, so we're going to look at +temperature and mole fraction + +phase diagrams. + +Again, a little more complicated +mathematically but + +more practical in real use. + +And this is T. And here is the, +sort of, form that these + +things take. + +So again, neither +one is linear. + +Up here, now, of course if you +raise the temperatures, that's + +where you end up with gas. + +If you lower the temperature, +you + +condense and get the liquid. + +So, this is TA star. + +TB star. + +So now I want to stick +with A as the + +more volatile component. + +At constant temperature, that +meant that pA star is bigger + +than pB star. + +In other words, the vapor +pressure over pure liquid A is + +higher than the vapor pressure +over pure liquid B. Similarly, + +now I've got constant pressure +and really what I'm looking + +at, let's say I'm at the +limit where I've + +got the pure liquid. + +Or the pure A. And now I'm going +to, let's say, raise the + +temperature until I'm at the +liquid-gas equilibrium. + +That's just the boiling point. + +So if A is the more volatile +component, it has the lower + +boiling point. + +And that's what this reflects. + +So higher pB star A corresponds +to lower TA star + +A. Which is just the boiling +point of pure A. + +So, this is called +the bubble line. + +That's called the dew line. + +All that means is, let's say +I'm at high temperature. + +I've got all gas. + +Right no coexistence, +no liquid yet. + +And I start to cool +things off. + +Just to where I just barely +start to get liquid. + +What you see that as is, +dew starts forming. + +A little bit of condensation. + +If you're outside, it means on +the grass a little bit of dew + +is forming. + +Similarly, if I start at low +temperature, all liquid now I + +start raising the temperature +until I just start to boil. + +I just start to see the +first bubbles forming. + +And so that's why these things +have those names. + +So now let's just follow along +what happens when I do the + +same sort of thing that +I illustrated there. + +I want to start at one point +in this phase diagram. + +And then start changing +the conditions. + +So let's start here. + +So I'm going to start all +in the liquid phase. + +That is, the temperature +is low. + +Here's xB. + +And my original temperature. + +Now I'm going to raise it. + +So if I raise it a little bit, +I reach a point at which I + +first start to boil. + +Start to find some gas +above the liquid. + +And if I look right here, +that'll be my composition. + +Let me raise it a little +farther, now that we've + +already seen the lever +rule and so forth. + +I'll raise it up to here. + +And that means that out here, +I suppose I should do here. + +So, here is the liquid mole +fraction at temperature two. + +xB at temperature two. + +This is yB at temperature two. + +The gas mole fraction. + +So as you should expect, what's +going to happen here is + +that the gas, this is going to +be lower in B. A, that means + +that the mole fraction +of A must be + +higher in the gas phase. + +That's one minus yB. + +So xA is one minus -- yA, which +is one minus yB higher + +in gas phase. + +Than xA, which is +one minus xB. + +In other words, the less +volatile component is enriched + +up in the gas phase. + +Now, what does that mean? + +That means I could follow the +same sort of procedure that I + +indicated before when we looked +at the pressure mole + +fraction phase diagram. + +Namely, I could do this +and now I could + +take the gas phase. + +Which has less of B. It +has more of A. And + +I can collect it. + +And then I can reduce +the temperature. + +So it liquefies. + +So I can condense it, +in other words. + +So now I'm going to start with, +let's say I lower the + +temperature enough so I've got +basically pure liquid. + +But its composition is the +same as the gas here. + +Because of course that's what +that liquid is formed from. + +I collected the gas +and separated it. + +So now I could start +all over again. + +Except instead of being here, +I'll be down here. + +And then I can raise the +temperature again. + +To some place where I choose. + +I could choose here, and +go all the way to hear. + +A great amount of enrichment. + +But I know from the lever rule +that if I do that, I'm going + +to have precious little +material over here. + +So I might prefer to raise the +temperature a little more. + +Still get a substantial +amount of enrichment. + +And now I've got, in the gas +phase, I'll further enriched + +in component A. And again +I can collect the gas. + +Condense it. + +Now I'm out here somewhere, I've +got all liquid and I'll + +raise the temperature again. + +And I can again keep walking +my way over. + +And that's what happens during +an ordinary distillation. + +Each step of the distillation +walks along in the phase + +diagram at some selected +point. + +And of course what you're +doing is, you're always + +condensing the gas. + +And starting with fresh liquid +that now is enriched in more + +volatile of the components. + +So of course if you're really +purifying, say, ethanol from + +an ethanol water mixture, +that's how you do it. + +Ethanol is the more volatile +component. + +So a still is set up. + +It will boil the stuff and +collect the gas and and + +condense it. + +And boil it again, +and so forth. + +And the whole thing can be set +up in a very efficient way. + +So you have essentially +continuous distillation. + +Where you have a whole sequence +of collection and + +condensation and reheating +and so forth events. + +So then, in a practical way, +it's possible to walk quite + +far along the distillation, +the coexistence curve, and + +distill to really a high +degree of purification. + +Any questions about +how that works? + +OK. + +I'll leave till next time the +discussion of the chemical + +potentials. + +But what we'll do, just to +foreshadow a little bit, what + +I'll do at the beginning of the +next lecture is what's at + +the end of your notes here. + +Which is just to say OK, now +if we look at Raoult's law, + +it's straightforward to say what +is the chemical potential + +for each of the substances in +the liquid and the gas phase. + +Of course, it has to be equal. + +Given that, that's for +an ideal solution. + +We can gain some insight +from that. + +And then look at real +solutions, non-ideal + +solutions, and understand a lot +of their behavior as well. + +Just from starting from our +understanding of what the + +chemical potential does even +in a simple ideal mixture. + +So we'll look at the chemical +potentials. + +And then we'll look at +non-ideal solution + +mixtures next time. + +See you then. \ No newline at end of file diff --git a/RWvi4Vx4CDc.txt b/RWvi4Vx4CDc.txt new file mode 100644 index 0000000000000000000000000000000000000000..68924e3d80fea985ca682959ddf20dd57f6321f2 --- /dev/null +++ b/RWvi4Vx4CDc.txt @@ -0,0 +1,6355 @@ +align:start position:0% + +okay good the final class in linear + + align:start position:0% +okay good the final class in linear + + + align:start position:0% +okay good the final class in linear +algebra at MIT this fall is to review + + align:start position:0% +algebra at MIT this fall is to review + + + align:start position:0% +algebra at MIT this fall is to review +the whole course and uh you know the + + align:start position:0% +the whole course and uh you know the + + + align:start position:0% +the whole course and uh you know the +best way I know how to review is to take + + align:start position:0% +best way I know how to review is to take + + + align:start position:0% +best way I know how to review is to take +old + + align:start position:0% +old + + + align:start position:0% +old +exams and just think through the proc + + align:start position:0% +exams and just think through the proc + + + align:start position:0% +exams and just think through the proc +problems so it'll be a three-hour exam + + align:start position:0% +problems so it'll be a three-hour exam + + + align:start position:0% +problems so it'll be a three-hour exam +next + + align:start position:0% +next + + + align:start position:0% +next +Thursday uh anybody who's got I mean + + align:start position:0% +Thursday uh anybody who's got I mean + + + align:start position:0% +Thursday uh anybody who's got I mean +nobody will be able to take an exam + + align:start position:0% +nobody will be able to take an exam + + + align:start position:0% +nobody will be able to take an exam +before Thursday anybody who needs to + + align:start position:0% +before Thursday anybody who needs to + + + align:start position:0% +before Thursday anybody who needs to +take it in some different way after + + align:start position:0% +take it in some different way after + + + align:start position:0% +take it in some different way after +Thursday should see me next Monday I'll + + align:start position:0% +Thursday should see me next Monday I'll + + + align:start position:0% +Thursday should see me next Monday I'll +be in my office Monday + + align:start position:0% +be in my office Monday + + + align:start position:0% +be in my office Monday +okay so may I just read out some + + align:start position:0% +okay so may I just read out some + + + align:start position:0% +okay so may I just read out some +problems and uh I'll let me bring the + + align:start position:0% +problems and uh I'll let me bring the + + + align:start position:0% +problems and uh I'll let me bring the +board down + + align:start position:0% + + + + align:start position:0% + +and let's start + + align:start position:0% +and let's start + + + align:start position:0% +and let's start +okay here's a + + align:start position:0% +okay here's a + + + align:start position:0% +okay here's a +question this is a this is about an a 3 + + align:start position:0% +question this is a this is about an a 3 + + + align:start position:0% +question this is a this is about an a 3 +byn + + align:start position:0% +byn + + + align:start position:0% +byn +Matrix and we're given so we're + + align:start position:0% +Matrix and we're given so we're + + + align:start position:0% +Matrix and we're given so we're +given + + align:start position:0% +given + + + align:start position:0% +given +given ax + + align:start position:0% +given ax + + + align:start position:0% +given ax += 1 0 has no + + align:start position:0% + + + + align:start position:0% + +solution and we're also given ax = 0 one + + align:start position:0% +solution and we're also given ax = 0 one + + + align:start position:0% +solution and we're also given ax = 0 one +Z has exactly one + + align:start position:0% +Z has exactly one + + + align:start position:0% +Z has exactly one +solution + + align:start position:0% +solution + + + align:start position:0% +solution +okay so you can you can probably + + align:start position:0% +okay so you can you can probably + + + align:start position:0% +okay so you can you can probably +anticipate my first question what can + + align:start position:0% +anticipate my first question what can + + + align:start position:0% +anticipate my first question what can +you tell me about M it's it's an M byn + + align:start position:0% +you tell me about M it's it's an M byn + + + align:start position:0% +you tell me about M it's it's an M byn +Matrix of rank r as always what can you + + align:start position:0% +Matrix of rank r as always what can you + + + align:start position:0% +Matrix of rank r as always what can you +tell me about those three numbers so + + align:start position:0% +tell me about those three numbers so + + + align:start position:0% +tell me about those three numbers so +what can we tell me about + + align:start position:0% + + + + align:start position:0% + +M the number of + + align:start position:0% +M the number of + + + align:start position:0% +M the number of +rows n the number of columns and R the + + align:start position:0% +rows n the number of columns and R the + + + align:start position:0% +rows n the number of columns and R the +rank + + align:start position:0% +rank + + + align:start position:0% +rank +okay see do you want to tell me first + + align:start position:0% +okay see do you want to tell me first + + + align:start position:0% +okay see do you want to tell me first +what m is how many rows in this + + align:start position:0% + + + + align:start position:0% + +Matrix must be + + align:start position:0% +Matrix must be + + + align:start position:0% +Matrix must be +three right we can't tell what n is but + + align:start position:0% +three right we can't tell what n is but + + + align:start position:0% +three right we can't tell what n is but +we can certainly tell that m is three + + align:start position:0% +we can certainly tell that m is three + + + align:start position:0% +we can certainly tell that m is three +okay and what do we know + + align:start position:0% +okay and what do we know + + + align:start position:0% +okay and what do we know +about um so what do these things tell us + + align:start position:0% +about um so what do these things tell us + + + align:start position:0% +about um so what do these things tell us +let's take them one at a time when when + + align:start position:0% +let's take them one at a time when when + + + align:start position:0% +let's take them one at a time when when +this when I discover that some equation + + align:start position:0% +this when I discover that some equation + + + align:start position:0% +this when I discover that some equation +has no solution that there's some right + + align:start position:0% +has no solution that there's some right + + + align:start position:0% +has no solution that there's some right +hand side with no answer what does that + + align:start position:0% +hand side with no answer what does that + + + align:start position:0% +hand side with no answer what does that +tell me about the rank + + align:start position:0% +tell me about the rank + + + align:start position:0% +tell me about the rank +rank of the + + align:start position:0% + + + + align:start position:0% + +matrix it's smaller than it's smaller + + align:start position:0% +matrix it's smaller than it's smaller + + + align:start position:0% +matrix it's smaller than it's smaller +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +than m is that right that this if if + + align:start position:0% +than m is that right that this if if + + + align:start position:0% +than m is that right that this if if +there's no solution that tells me that + + align:start position:0% +there's no solution that tells me that + + + align:start position:0% +there's no solution that tells me that +the rank that the that some rows of the + + align:start position:0% +the rank that the that some rows of the + + + align:start position:0% +the rank that the that some rows of the +Matrix are combinations of other + + align:start position:0% +Matrix are combinations of other + + + align:start position:0% +Matrix are combinations of other +rows because if if if I had a pivot in + + align:start position:0% +rows because if if if I had a pivot in + + + align:start position:0% +rows because if if if I had a pivot in +every row + + align:start position:0% + + + + align:start position:0% + +then I would certainly be able to solve + + align:start position:0% +then I would certainly be able to solve + + + align:start position:0% +then I would certainly be able to solve +the system I would have particular + + align:start position:0% +the system I would have particular + + + align:start position:0% +the system I would have particular +Solutions and all all the good stuff so + + align:start position:0% +Solutions and all all the good stuff so + + + align:start position:0% +Solutions and all all the good stuff so +if if anytime that there's a system that + + align:start position:0% +if if anytime that there's a system that + + + align:start position:0% +if if anytime that there's a system that +has with no solutions that tells me that + + align:start position:0% +has with no solutions that tells me that + + + align:start position:0% +has with no solutions that tells me that +R must be below M what about uh the fact + + align:start position:0% +R must be below M what about uh the fact + + + align:start position:0% +R must be below M what about uh the fact +that if when there is a solution there's + + align:start position:0% +that if when there is a solution there's + + + align:start position:0% +that if when there is a solution there's +only one what does that tell + + align:start position:0% +only one what does that tell + + + align:start position:0% +only one what does that tell +me Well normally there'd be one solution + + align:start position:0% +me Well normally there'd be one solution + + + align:start position:0% +me Well normally there'd be one solution +and then we could add in anything in the + + align:start position:0% +and then we could add in anything in the + + + align:start position:0% +and then we could add in anything in the +null space so this is telling me the + + align:start position:0% +null space so this is telling me the + + + align:start position:0% +null space so this is telling me the +null space only has the zero Vector in + + align:start position:0% +null space only has the zero Vector in + + + align:start position:0% +null space only has the zero Vector in +it there's just that there's just one + + align:start position:0% +it there's just that there's just one + + + align:start position:0% +it there's just that there's just one +solution period so what does that tell + + align:start position:0% +solution period so what does that tell + + + align:start position:0% +solution period so what does that tell +me the null space has only the zero + + align:start position:0% +me the null space has only the zero + + + align:start position:0% +me the null space has only the zero +Vector in it that tells me what does + + align:start position:0% +Vector in it that tells me what does + + + align:start position:0% +Vector in it that tells me what does +that tell me about the relation of R to + + align:start position:0% +that tell me about the relation of R to + + + align:start position:0% +that tell me about the relation of R to +n so this is one solution only that + + align:start position:0% +n so this is one solution only that + + + align:start position:0% +n so this is one solution only that +means the null space of the Matrix must + + align:start position:0% +means the null space of the Matrix must + + + align:start position:0% +means the null space of the Matrix must +be just the zero vector and what what + + align:start position:0% +be just the zero vector and what what + + + align:start position:0% +be just the zero vector and what what +does that tell me about R and + + align:start position:0% +does that tell me about R and + + + align:start position:0% +does that tell me about R and +N they're equal The Columns are + + align:start position:0% +N they're equal The Columns are + + + align:start position:0% +N they're equal The Columns are +independent so I've got now r equal n + + align:start position:0% +independent so I've got now r equal n + + + align:start position:0% +independent so I've got now r equal n +and R less than M and now I and I also + + align:start position:0% +and R less than M and now I and I also + + + align:start position:0% +and R less than M and now I and I also +know m is three so those are really the + + align:start position:0% +know m is three so those are really the + + + align:start position:0% +know m is three so those are really the +facts I know n equals + + align:start position:0% +facts I know n equals + + + align:start position:0% +facts I know n equals +R and those numbers are smaller than + + align:start position:0% +R and those numbers are smaller than + + + align:start position:0% +R and those numbers are smaller than +three uh sorry yeah yeah R is smaller + + align:start position:0% +three uh sorry yeah yeah R is smaller + + + align:start position:0% +three uh sorry yeah yeah R is smaller +than + + align:start position:0% +than + + + align:start position:0% +than +M and N of course is also so I guess + + align:start position:0% +M and N of course is also so I guess + + + align:start position:0% +M and N of course is also so I guess +this summarizes what what we can + + align:start position:0% +this summarizes what what we can + + + align:start position:0% +this summarizes what what we can +tell in fact why not give me a + + align:start position:0% +tell in fact why not give me a + + + align:start position:0% +tell in fact why not give me a +matrix because I would often ask for an + + align:start position:0% +matrix because I would often ask for an + + + align:start position:0% +matrix because I would often ask for an +example of such a matrix can you give me + + align:start position:0% +example of such a matrix can you give me + + + align:start position:0% +example of such a matrix can you give me +a matrix a that that's an example that + + align:start position:0% +a matrix a that that's an example that + + + align:start position:0% +a matrix a that that's an example that +shows this shows this possibility that + + align:start position:0% +shows this shows this possibility that + + + align:start position:0% +shows this shows this possibility that +exactly that that that there's no + + align:start position:0% +exactly that that that there's no + + + align:start position:0% +exactly that that that there's no +solution with uh with that right hand + + align:start position:0% +solution with uh with that right hand + + + align:start position:0% +solution with uh with that right hand +side but there's there's exactly one + + align:start position:0% +side but there's there's exactly one + + + align:start position:0% +side but there's there's exactly one +solution with this right hand side + + align:start position:0% +solution with this right hand side + + + align:start position:0% +solution with this right hand side +anybody want to suggest a Matrix that + + align:start position:0% +anybody want to suggest a Matrix that + + + align:start position:0% +anybody want to suggest a Matrix that +that that does + + align:start position:0% +that that does + + + align:start position:0% +that that does +that let's see what do I what Vector do + + align:start position:0% +that let's see what do I what Vector do + + + align:start position:0% +that let's see what do I what Vector do +I want in in the column + + align:start position:0% +I want in in the column + + + align:start position:0% +I want in in the column +space I want 0 one 0 to be in the column + + align:start position:0% +space I want 0 one 0 to be in the column + + + align:start position:0% +space I want 0 one 0 to be in the column +space because I'm I'm able to solve for + + align:start position:0% +space because I'm I'm able to solve for + + + align:start position:0% +space because I'm I'm able to solve for +that so let's put 0 one 0 in the column + + align:start position:0% +that so let's put 0 one 0 in the column + + + align:start position:0% +that so let's put 0 one 0 in the column +space actually I could stop right + + align:start position:0% +space actually I could stop right + + + align:start position:0% +space actually I could stop right +there that would be a matrix with m + + align:start position:0% +there that would be a matrix with m + + + align:start position:0% +there that would be a matrix with m +equal 3 three rows and n and R are both + + align:start position:0% +equal 3 three rows and n and R are both + + + align:start position:0% +equal 3 three rows and n and R are both +both one rank + + align:start position:0% +both one rank + + + align:start position:0% +both one rank +one one + + align:start position:0% +one one + + + align:start position:0% +one one +column + + align:start position:0% +column + + + align:start position:0% +column +and of course there's no solution to + + align:start position:0% +and of course there's no solution to + + + align:start position:0% +and of course there's no solution to +that one so that's perfectly good as it + + align:start position:0% +that one so that's perfectly good as it + + + align:start position:0% +that one so that's perfectly good as it +is or if you kind of have a prejudice + + align:start position:0% +is or if you kind of have a prejudice + + + align:start position:0% +is or if you kind of have a prejudice +against matrices that only have one + + align:start position:0% +against matrices that only have one + + + align:start position:0% +against matrices that only have one +column I'll I'll accept a second column + + align:start position:0% +column I'll I'll accept a second column + + + align:start position:0% +column I'll I'll accept a second column +so what could I include as a second + + align:start position:0% +so what could I include as a second + + + align:start position:0% +so what could I include as a second +column that would just be a different + + align:start position:0% +column that would just be a different + + + align:start position:0% +column that would just be a different +answer but equally good uh I could put + + align:start position:0% +answer but equally good uh I could put + + + align:start position:0% +answer but equally good uh I could put +this Vector in the column space too if I + + align:start position:0% +this Vector in the column space too if I + + + align:start position:0% +this Vector in the column space too if I +wanted that would now be a case with Ral + + align:start position:0% +wanted that would now be a case with Ral + + + align:start position:0% +wanted that would now be a case with Ral +Nal + + align:start position:0% +Nal + + + align:start position:0% +Nal +2 but of course three m m is still three + + align:start position:0% +2 but of course three m m is still three + + + align:start position:0% +2 but of course three m m is still three +and this Vector is not in the column + + align:start position:0% +and this Vector is not in the column + + + align:start position:0% +and this Vector is not in the column +space so you're this is just like + + align:start position:0% +space so you're this is just like + + + align:start position:0% +space so you're this is just like +prompting us to remember all those + + align:start position:0% +prompting us to remember all those + + + align:start position:0% +prompting us to remember all those +things column space null space all that + + align:start position:0% +things column space null space all that + + + align:start position:0% +things column space null space all that +stuff now I probably asked a second + + align:start position:0% +stuff now I probably asked a second + + + align:start position:0% +stuff now I probably asked a second +question about this type of thing + + align:start position:0% + + + + align:start position:0% + +okay oh I even asked write down an + + align:start position:0% +okay oh I even asked write down an + + + align:start position:0% +okay oh I even asked write down an +example of a matrix that fits the + + align:start position:0% +example of a matrix that fits the + + + align:start position:0% +example of a matrix that fits the +description um + + align:start position:0% +description um + + + align:start position:0% +description um +H I guess I haven't learned anything in + + align:start position:0% +H I guess I haven't learned anything in + + + align:start position:0% +H I guess I haven't learned anything in +uh 26 years okay uh cross out all + + align:start position:0% +uh 26 years okay uh cross out all + + + align:start position:0% +uh 26 years okay uh cross out all +statements that are false about any + + align:start position:0% +statements that are false about any + + + align:start position:0% +statements that are false about any +Matrix with these so again these are + + align:start position:0% +Matrix with these so again these are + + + align:start position:0% +Matrix with these so again these are +this is the preliminary State these are + + align:start position:0% +this is the preliminary State these are + + + align:start position:0% +this is the preliminary State these are +the facts about my Matrix this is one + + align:start position:0% +the facts about my Matrix this is one + + + align:start position:0% +the facts about my Matrix this is one +example but of course by having an + + align:start position:0% +example but of course by having an + + + align:start position:0% +example but of course by having an +example it'll be easy to check some of + + align:start position:0% +example it'll be easy to check some of + + + align:start position:0% +example it'll be easy to check some of +these facts or nonfacts let me uh let me + + align:start position:0% +these facts or nonfacts let me uh let me + + + align:start position:0% +these facts or nonfacts let me uh let me +write + + align:start position:0% +write + + + align:start position:0% +write +down some uh facts some some possible + + align:start position:0% +down some uh facts some some possible + + + align:start position:0% +down some uh facts some some possible +facts true so this is really true or + + align:start position:0% +facts true so this is really true or + + + align:start position:0% +facts true so this is really true or +false the + + align:start position:0% +false the + + + align:start position:0% +false the +determinant of this is part one the + + align:start position:0% +determinant of this is part one the + + + align:start position:0% +determinant of this is part one the +determinant of a transpose a is the same + + align:start position:0% +determinant of a transpose a is the same + + + align:start position:0% +determinant of a transpose a is the same +as the determinant of AA transpose is + + align:start position:0% +as the determinant of AA transpose is + + + align:start position:0% +as the determinant of AA transpose is +that true or not second + + align:start position:0% +that true or not second + + + align:start position:0% +that true or not second +one a transpose a is + + align:start position:0% +one a transpose a is + + + align:start position:0% +one a transpose a is +invertible is + + align:start position:0% + + + + align:start position:0% + +invertible third possible fact a a + + align:start position:0% +invertible third possible fact a a + + + align:start position:0% +invertible third possible fact a a +transpose is positive + + align:start position:0% + + + + align:start position:0% + +definite so you see how on an exam + + align:start position:0% +definite so you see how on an exam + + + align:start position:0% +definite so you see how on an exam +question I try to connect the different + + align:start position:0% +question I try to connect the different + + + align:start position:0% +question I try to connect the different +parts of the course so + + align:start position:0% +parts of the course so + + + align:start position:0% +parts of the course so +well I mean the simplest way would be to + + align:start position:0% +well I mean the simplest way would be to + + + align:start position:0% +well I mean the simplest way would be to +try it with that Matrix a as a as a as a + + align:start position:0% +try it with that Matrix a as a as a as a + + + align:start position:0% +try it with that Matrix a as a as a as a +good example uh but maybe we can answer + + align:start position:0% +good example uh but maybe we can answer + + + align:start position:0% +good example uh but maybe we can answer +uh even directly let let me take number + + align:start position:0% +uh even directly let let me take number + + + align:start position:0% +uh even directly let let me take number +two + + align:start position:0% +two + + + align:start position:0% +two +first because + + align:start position:0% +first because + + + align:start position:0% +first because +I'm you know I'm very very fond of that + + align:start position:0% +I'm you know I'm very very fond of that + + + align:start position:0% +I'm you know I'm very very fond of that +Matrix a transpose + + align:start position:0% +Matrix a transpose + + + align:start position:0% +Matrix a transpose +a + + align:start position:0% +a + + + align:start position:0% +a +and when is it invertible + + align:start position:0% +and when is it invertible + + + align:start position:0% +and when is it invertible +when is the Matrix a transpose a + + align:start position:0% + + + + align:start position:0% + +invertible the the great thing is that I + + align:start position:0% +invertible the the great thing is that I + + + align:start position:0% +invertible the the great thing is that I +can tell from the from the rank of a + + align:start position:0% +can tell from the from the rank of a + + + align:start position:0% +can tell from the from the rank of a +that I don't have to multiply out a + + align:start position:0% +that I don't have to multiply out a + + + align:start position:0% +that I don't have to multiply out a +transpose a a transpose a is + + align:start position:0% +transpose a a transpose a is + + + align:start position:0% +transpose a a transpose a is +invertible well if a has a null space + + align:start position:0% +invertible well if a has a null space + + + align:start position:0% +invertible well if a has a null space +other than the zero Vector then it it's + + align:start position:0% +other than the zero Vector then it it's + + + align:start position:0% +other than the zero Vector then it it's +no way it's going to be invertible but + + align:start position:0% +no way it's going to be invertible but + + + align:start position:0% +no way it's going to be invertible but +the beauty is if the null space of a is + + align:start position:0% +the beauty is if the null space of a is + + + align:start position:0% +the beauty is if the null space of a is +just the zero Vector so the fact the key + + align:start position:0% +just the zero Vector so the fact the key + + + align:start position:0% +just the zero Vector so the fact the key +fact is this is invertible if R equals n + + align:start position:0% +fact is this is invertible if R equals n + + + align:start position:0% +fact is this is invertible if R equals n +by which I mean independent + + align:start position:0% + + + + align:start position:0% + +Columns of a in a in The Matrix a if R + + align:start position:0% +Columns of a in a in The Matrix a if R + + + align:start position:0% +Columns of a in a in The Matrix a if R +equals n if the Matrix a has independent + + align:start position:0% +equals n if the Matrix a has independent + + + align:start position:0% +equals n if the Matrix a has independent +columns then this combination a + + align:start position:0% +columns then this combination a + + + align:start position:0% +columns then this combination a +transpose a is square and still that + + align:start position:0% +transpose a is square and still that + + + align:start position:0% +transpose a is square and still that +same space only the zero Vector + + align:start position:0% +same space only the zero Vector + + + align:start position:0% +same space only the zero Vector +independent columns all good and so + + align:start position:0% +independent columns all good and so + + + align:start position:0% +independent columns all good and so +what's the what's the true false is it + + align:start position:0% +what's the what's the true false is it + + + align:start position:0% +what's the what's the true false is it +is this middle one t or F for this in + + align:start position:0% +is this middle one t or F for this in + + + align:start position:0% +is this middle one t or F for this in +this + + align:start position:0% +this + + + align:start position:0% +this +setup well we discovered that we + + align:start position:0% +setup well we discovered that we + + + align:start position:0% +setup well we discovered that we +discovered that that R was n from that + + align:start position:0% +discovered that that R was n from that + + + align:start position:0% +discovered that that R was n from that +second fact so this is a true that's a + + align:start position:0% +second fact so this is a true that's a + + + align:start position:0% +second fact so this is a true that's a +true and of course a transpose a in this + + align:start position:0% +true and of course a transpose a in this + + + align:start position:0% +true and of course a transpose a in this +example would probably be what would a + + align:start position:0% +example would probably be what would a + + + align:start position:0% +example would probably be what would a +transpose a be for that + + align:start position:0% +transpose a be for that + + + align:start position:0% +transpose a be for that +Matrix can you multiply a transpose a + + align:start position:0% +Matrix can you multiply a transpose a + + + align:start position:0% +Matrix can you multiply a transpose a +and see what it looks like for that + + align:start position:0% +and see what it looks like for that + + + align:start position:0% +and see what it looks like for that +Matrix what shape would it + + align:start position:0% +Matrix what shape would it + + + align:start position:0% +Matrix what shape would it +be it'll be 2x two and what Matrix will + + align:start position:0% +be it'll be 2x two and what Matrix will + + + align:start position:0% +be it'll be 2x two and what Matrix will +it + + align:start position:0% +it + + + align:start position:0% +it +be the identity so checks out okay what + + align:start position:0% +be the identity so checks out okay what + + + align:start position:0% +be the identity so checks out okay what +about AA + + align:start position:0% + + + + align:start position:0% + +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +well depending on the shape of a it + + align:start position:0% +well depending on the shape of a it + + + align:start position:0% +well depending on the shape of a it +could be good or not so good it's always + + align:start position:0% +could be good or not so good it's always + + + align:start position:0% +could be good or not so good it's always +symmetric it's always square but what's + + align:start position:0% +symmetric it's always square but what's + + + align:start position:0% +symmetric it's always square but what's +the size now this is 3 by n and this is + + align:start position:0% +the size now this is 3 by n and this is + + + align:start position:0% +the size now this is 3 by n and this is +n + + align:start position:0% +n + + + align:start position:0% +n +by3 so the result is + + align:start position:0% + + + + align:start position:0% + +3x3 is it positive + + align:start position:0% + + + + align:start position:0% + +definite I don't think so + + align:start position:0% +definite I don't think so + + + align:start position:0% +definite I don't think so +false If I multiply that by a transpose + + align:start position:0% +false If I multiply that by a transpose + + + align:start position:0% +false If I multiply that by a transpose +a a transpose + + align:start position:0% +a a transpose + + + align:start position:0% +a a transpose +what would the rank + + align:start position:0% +what would the rank + + + align:start position:0% +what would the rank +be it would be the same as the rank of a + + align:start position:0% +be it would be the same as the rank of a + + + align:start position:0% +be it would be the same as the rank of a +that's that's it would be just rank + + align:start position:0% +that's that's it would be just rank + + + align:start position:0% +that's that's it would be just rank +two and if it's 3x3 and it's only rank + + align:start position:0% +two and if it's 3x3 and it's only rank + + + align:start position:0% +two and if it's 3x3 and it's only rank +two it's certainly not positive definite + + align:start position:0% +two it's certainly not positive definite + + + align:start position:0% +two it's certainly not positive definite +so what's what could I say about AA + + align:start position:0% +so what's what could I say about AA + + + align:start position:0% +so what's what could I say about AA +transpose if I wanted to like say + + align:start position:0% +transpose if I wanted to like say + + + align:start position:0% +transpose if I wanted to like say +something true about + + align:start position:0% +something true about + + + align:start position:0% +something true about +it it's true that it is + + align:start position:0% +it it's true that it is + + + align:start position:0% +it it's true that it is +positive semi-definite if I made this + + align:start position:0% +positive semi-definite if I made this + + + align:start position:0% +positive semi-definite if I made this +semi-definite it would always always be + + align:start position:0% +semi-definite it would always always be + + + align:start position:0% +semi-definite it would always always be +true always but if I'm looking for + + align:start position:0% +true always but if I'm looking for + + + align:start position:0% +true always but if I'm looking for +positive definite then I'm looking at + + align:start position:0% +positive definite then I'm looking at + + + align:start position:0% +positive definite then I'm looking at +the null space of whatever is here and + + align:start position:0% +the null space of whatever is here and + + + align:start position:0% +the null space of whatever is here and +in this case uh it's got a null + + align:start position:0% +in this case uh it's got a null + + + align:start position:0% +in this case uh it's got a null +space so AA so we just figure it out + + align:start position:0% +space so AA so we just figure it out + + + align:start position:0% +space so AA so we just figure it out +here A A transposed for that Matrix will + + align:start position:0% +here A A transposed for that Matrix will + + + align:start position:0% +here A A transposed for that Matrix will +be + + align:start position:0% +be + + + align:start position:0% +be +3x3 if I multiplied a by a transpose + + align:start position:0% +3x3 if I multiplied a by a transpose + + + align:start position:0% +3x3 if I multiplied a by a transpose +what would the first row be + + align:start position:0% + + + + align:start position:0% + +all zeros right first row of AA + + align:start position:0% +all zeros right first row of AA + + + align:start position:0% +all zeros right first row of AA +transposed could only be all + + align:start position:0% +transposed could only be all + + + align:start position:0% +transposed could only be all +zeros so it's probably a one there and a + + align:start position:0% +zeros so it's probably a one there and a + + + align:start position:0% +zeros so it's probably a one there and a +one there something like that but uh I I + + align:start position:0% +one there something like that but uh I I + + + align:start position:0% +one there something like that but uh I I +don't even know if that's right but it's + + align:start position:0% +don't even know if that's right but it's + + + align:start position:0% +don't even know if that's right but it's +all zeros there so it's certainly not + + align:start position:0% +all zeros there so it's certainly not + + + align:start position:0% +all zeros there so it's certainly not +positive definite let me not put up + + align:start position:0% +positive definite let me not put up + + + align:start position:0% +positive definite let me not put up +anything I'm not don't check what about + + align:start position:0% +anything I'm not don't check what about + + + align:start position:0% +anything I'm not don't check what about +this determinant oh well I + + align:start position:0% +this determinant oh well I + + + align:start position:0% +this determinant oh well I +guess that's a sort of tricky + + align:start position:0% +guess that's a sort of tricky + + + align:start position:0% +guess that's a sort of tricky +question is it true or false in this + + align:start position:0% +question is it true or false in this + + + align:start position:0% +question is it true or false in this +case it's false + + align:start position:0% +case it's false + + + align:start position:0% +case it's false +apparently because a transpose a is + + align:start position:0% +apparently because a transpose a is + + + align:start position:0% +apparently because a transpose a is +invertible we just got a true for this + + align:start position:0% +invertible we just got a true for this + + + align:start position:0% +invertible we just got a true for this +one and we got a false we got a we got a + + align:start position:0% +one and we got a false we got a we got a + + + align:start position:0% +one and we got a false we got a we got a +non-invertible one for this one so + + align:start position:0% +non-invertible one for this one so + + + align:start position:0% +non-invertible one for this one so +actually this one is false number + + align:start position:0% +actually this one is false number + + + align:start position:0% +actually this one is false number +one that surprises us actually because + + align:start position:0% +one that surprises us actually because + + + align:start position:0% +one that surprises us actually because +it's I mean why was it tricky because + + align:start position:0% +it's I mean why was it tricky because + + + align:start position:0% +it's I mean why was it tricky because +what is true about determinants + + align:start position:0% +what is true about determinants + + + align:start position:0% +what is true about determinants +this would be true if those matrices + + align:start position:0% +this would be true if those matrices + + + align:start position:0% +this would be true if those matrices +were square if I have two square + + align:start position:0% +were square if I have two square + + + align:start position:0% +were square if I have two square +matrices a and any other Matrix B could + + align:start position:0% +matrices a and any other Matrix B could + + + align:start position:0% +matrices a and any other Matrix B could +be a transpose could be somebody else's + + align:start position:0% +be a transpose could be somebody else's + + + align:start position:0% +be a transpose could be somebody else's +Matrix then it would be true that the + + align:start position:0% +Matrix then it would be true that the + + + align:start position:0% +Matrix then it would be true that the +determinant of ba would equal the + + align:start position:0% +determinant of ba would equal the + + + align:start position:0% +determinant of ba would equal the +determinant of ab but if the matrices + + align:start position:0% +determinant of ab but if the matrices + + + align:start position:0% +determinant of ab but if the matrices +are not + + align:start position:0% +are not + + + align:start position:0% +are not +square and it would actually be true + + align:start position:0% +square and it would actually be true + + + align:start position:0% +square and it would actually be true +that it would be that would equal that + + align:start position:0% +that it would be that would equal that + + + align:start position:0% +that it would be that would equal that +this would equal the determinant of a + + align:start position:0% +this would equal the determinant of a + + + align:start position:0% +this would equal the determinant of a +times the determinant of a transpose we + + align:start position:0% +times the determinant of a transpose we + + + align:start position:0% +times the determinant of a transpose we +could even split up those two separate + + align:start position:0% +could even split up those two separate + + + align:start position:0% +could even split up those two separate +determinants and of course those would + + align:start position:0% +determinants and of course those would + + + align:start position:0% +determinants and of course those would +be equal but only when a is + + align:start position:0% +be equal but only when a is + + + align:start position:0% +be equal but only when a is +square so that's just uh that's a + + align:start position:0% +square so that's just uh that's a + + + align:start position:0% +square so that's just uh that's a +question that rests on the the falseness + + align:start position:0% +question that rests on the the falseness + + + align:start position:0% +question that rests on the the falseness +rests on the fact that the Matrix isn't + + align:start position:0% +rests on the fact that the Matrix isn't + + + align:start position:0% +rests on the fact that the Matrix isn't +Square in the first place okay good um + + align:start position:0% +Square in the first place okay good um + + + align:start position:0% +Square in the first place okay good um +let's + + align:start position:0% +let's + + + align:start position:0% +let's +see uh oh now even asks more prove prove + + align:start position:0% +see uh oh now even asks more prove prove + + + align:start position:0% +see uh oh now even asks more prove prove +that a transpose y equal + + align:start position:0% +that a transpose y equal + + + align:start position:0% +that a transpose y equal +c h God it's this question goes on and + + align:start position:0% +c h God it's this question goes on and + + + align:start position:0% +c h God it's this question goes on and +on + + align:start position:0% +on + + + align:start position:0% +on +um now I ask you about a transpose yals + + align:start position:0% +um now I ask you about a transpose yals + + + align:start position:0% +um now I ask you about a transpose yals +C so I'm asking you about the equation + + align:start position:0% +C so I'm asking you about the equation + + + align:start position:0% +C so I'm asking you about the equation +about the Matrix a transpose and I want + + align:start position:0% +about the Matrix a transpose and I want + + + align:start position:0% +about the Matrix a transpose and I want +you to prove that it has at least one + + align:start position:0% + + + + align:start position:0% + +solution one solution + + align:start position:0% +solution one solution + + + align:start position:0% +solution one solution +for every C every right hand side C and + + align:start position:0% +for every C every right hand side C and + + + align:start position:0% +for every C every right hand side C and +in fact in + + align:start position:0% +in fact in + + + align:start position:0% +in fact in +fact infinitely many + + align:start position:0% + + + + align:start position:0% + +solutions for every + + align:start position:0% +solutions for every + + + align:start position:0% +solutions for every +C okay well none of this is difficult + + align:start position:0% +C okay well none of this is difficult + + + align:start position:0% +C okay well none of this is difficult +but it's been + + align:start position:0% +but it's been + + + align:start position:0% +but it's been +uh a little + + align:start position:0% +uh a little + + + align:start position:0% +uh a little +while so we just have to think again + + align:start position:0% +while so we just have to think again + + + align:start position:0% +while so we just have to think again +when I have a system of + + align:start position:0% +when I have a system of + + + align:start position:0% +when I have a system of +equations this is this Matrix a + + align:start position:0% +equations this is this Matrix a + + + align:start position:0% +equations this is this Matrix a +transposes now instead of + + align:start position:0% +transposes now instead of + + + align:start position:0% +transposes now instead of +being 3x n it's n by3 it's it's n by m + + align:start position:0% +being 3x n it's n by3 it's it's n by m + + + align:start position:0% +being 3x n it's n by3 it's it's n by m +of + + align:start position:0% + + + + align:start position:0% + +course to show that a that a system has + + align:start position:0% +course to show that a that a system has + + + align:start position:0% +course to show that a that a system has +at least one + + align:start position:0% + + + + align:start position:0% + +solution when does this when does the + + align:start position:0% +solution when does this when does the + + + align:start position:0% +solution when does this when does the +system when is the system always + + align:start position:0% +system when is the system always + + + align:start position:0% +system when is the system always +solvable + + align:start position:0% + + + + align:start position:0% + +when it has full row rank when the rows + + align:start position:0% +when it has full row rank when the rows + + + align:start position:0% +when it has full row rank when the rows +are independent here we have n + + align:start position:0% +are independent here we have n + + + align:start position:0% +are independent here we have n +rows and that's the rank so at least one + + align:start position:0% +rows and that's the rank so at least one + + + align:start position:0% +rows and that's the rank so at least one +solution + + align:start position:0% +solution + + + align:start position:0% +solution +because + + align:start position:0% +because + + + align:start position:0% +because +because the number of rows which is n + + align:start position:0% +because the number of rows which is n + + + align:start position:0% +because the number of rows which is n +for the transpose is equal to R the + + align:start position:0% +for the transpose is equal to R the + + + align:start position:0% +for the transpose is equal to R the +rank this this has this a transpose has + + align:start position:0% +rank this this has this a transpose has + + + align:start position:0% +rank this this has this a transpose has +has independent rows because a had + + align:start position:0% +has independent rows because a had + + + align:start position:0% +has independent rows because a had +independent columns + + align:start position:0% +independent columns + + + align:start position:0% +independent columns +right the original a had + + align:start position:0% +right the original a had + + + align:start position:0% +right the original a had +independent + + align:start position:0% +independent + + + align:start position:0% +independent +columns when we transpose it it has + + align:start position:0% +columns when we transpose it it has + + + align:start position:0% +columns when we transpose it it has +independent rows so there's at least one + + align:start position:0% +independent rows so there's at least one + + + align:start position:0% +independent rows so there's at least one +solution but now how do I even know that + + align:start position:0% +solution but now how do I even know that + + + align:start position:0% +solution but now how do I even know that +there are infinitely many solutions oh I + + align:start position:0% +there are infinitely many solutions oh I + + + align:start position:0% +there are infinitely many solutions oh I +I what do I I want to know something + + align:start position:0% +I what do I I want to know something + + + align:start position:0% +I what do I I want to know something +about the null space what's the + + align:start position:0% +about the null space what's the + + + align:start position:0% +about the null space what's the +dimension of the null space of a + + align:start position:0% +dimension of the null space of a + + + align:start position:0% +dimension of the null space of a +transpose so so the answer has got to be + + align:start position:0% +transpose so so the answer has got to be + + + align:start position:0% +transpose so so the answer has got to be +the + + align:start position:0% +the + + + align:start position:0% +the +dimension of the null space of a + + align:start position:0% +dimension of the null space of a + + + align:start position:0% +dimension of the null space of a +transpose what's the general fact if if + + align:start position:0% +transpose what's the general fact if if + + + align:start position:0% +transpose what's the general fact if if +it's an if I have if a is an M byn + + align:start position:0% +it's an if I have if a is an M byn + + + align:start position:0% +it's an if I have if a is an M byn +Matrix of rank R what's the dimension of + + align:start position:0% +Matrix of rank R what's the dimension of + + + align:start position:0% +Matrix of rank R what's the dimension of +a transpose of the null space of a + + align:start position:0% +a transpose of the null space of a + + + align:start position:0% +a transpose of the null space of a +transpose you remember that little + + align:start position:0% +transpose you remember that little + + + align:start position:0% +transpose you remember that little +fourth Subspace that's tagging along + + align:start position:0% +fourth Subspace that's tagging along + + + align:start position:0% +fourth Subspace that's tagging along +down in our big picture its Dimension + + align:start position:0% +down in our big picture its Dimension + + + align:start position:0% +down in our big picture its Dimension +was M minus r + + align:start position:0% + + + + align:start position:0% + +and that's bigger than zero m is bigger + + align:start position:0% +and that's bigger than zero m is bigger + + + align:start position:0% +and that's bigger than zero m is bigger +than + + align:start position:0% +than + + + align:start position:0% +than +R so there's a lot in that n + + align:start position:0% + + + + align:start position:0% + +space so there's always one solution + + align:start position:0% +space so there's always one solution + + + align:start position:0% +space so there's always one solution +because and this is speaking about a + + align:start position:0% + + + + align:start position:0% + +transpose so for a transposed the roles + + align:start position:0% +transpose so for a transposed the roles + + + align:start position:0% +transpose so for a transposed the roles +of M and N are reversed of course so I'm + + align:start position:0% +of M and N are reversed of course so I'm + + + align:start position:0% +of M and N are reversed of course so I'm +keep keep in mind that that this board + + align:start position:0% +keep keep in mind that that this board + + + align:start position:0% +keep keep in mind that that this board +was about a transposed so the rules so + + align:start position:0% +was about a transposed so the rules so + + + align:start position:0% +was about a transposed so the rules so +it's the null space of a transposed and + + align:start position:0% +it's the null space of a transposed and + + + align:start position:0% +it's the null space of a transposed and +there are M minus r free + + align:start position:0% +there are M minus r free + + + align:start position:0% +there are M minus r free +variables okay that's like just some + + align:start position:0% +variables okay that's like just some + + + align:start position:0% +variables okay that's like just some +uh review can I take another problem + + align:start position:0% +uh review can I take another problem + + + align:start position:0% +uh review can I take another problem +that's also sort of + + align:start position:0% +that's also sort of + + + align:start position:0% +that's also sort of +suppose The Matrix a has three columns + + align:start position:0% +suppose The Matrix a has three columns + + + align:start position:0% +suppose The Matrix a has three columns +V1 V2 + + align:start position:0% +V1 V2 + + + align:start position:0% +V1 V2 +V3 those are The Columns of The Matrix + + align:start position:0% +V3 those are The Columns of The Matrix + + + align:start position:0% +V3 those are The Columns of The Matrix +all + + align:start position:0% +all + + + align:start position:0% +all +right question + + align:start position:0% +right question + + + align:start position:0% +right question +a + + align:start position:0% +a + + + align:start position:0% +a +solve a x = V1 - V2 + + + align:start position:0% +solve a x = V1 - V2 + + + + align:start position:0% +solve a x = V1 - V2 + +V3 tell me what x + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +well there you're seeing the most the + + align:start position:0% +well there you're seeing the most the + + + align:start position:0% +well there you're seeing the most the +one absolutely + + align:start position:0% +one absolutely + + + align:start position:0% +one absolutely +essential + + align:start position:0% +essential + + + align:start position:0% +essential +fact about matrix multiplication how + + align:start position:0% +fact about matrix multiplication how + + + align:start position:0% +fact about matrix multiplication how +does it work when it when we do it a + + align:start position:0% +does it work when it when we do it a + + + align:start position:0% +does it work when it when we do it a +column at a time the very very first day + + align:start position:0% +column at a time the very very first day + + + align:start position:0% +column at a time the very very first day +way back in September we did + + align:start position:0% +way back in September we did + + + align:start position:0% +way back in September we did +multiplication a column at a time so + + align:start position:0% +multiplication a column at a time so + + + align:start position:0% +multiplication a column at a time so +what's what's X just tell me one minus + + align:start position:0% +what's what's X just tell me one minus + + + align:start position:0% +what's what's X just tell me one minus +one one thanks okay everybody's got that + + align:start position:0% +one one thanks okay everybody's got that + + + align:start position:0% +one one thanks okay everybody's got that +okay then the next question is suppose + + align:start position:0% +okay then the next question is suppose + + + align:start position:0% +okay then the next question is suppose +that combination is zero oh yeah okay + + align:start position:0% +that combination is zero oh yeah okay + + + align:start position:0% +that combination is zero oh yeah okay +okay so question B + + align:start position:0% +okay so question B + + + align:start position:0% +okay so question B +says Part B + + align:start position:0% +says Part B + + + align:start position:0% +says Part B +says + + align:start position:0% + + + + align:start position:0% + +suppose this + + align:start position:0% +suppose this + + + align:start position:0% +suppose this +thing is + + align:start position:0% +thing is + + + align:start position:0% +thing is +zero suppose that's + + align:start position:0% +zero suppose that's + + + align:start position:0% +zero suppose that's +zero then the solution is not + + align:start position:0% +zero then the solution is not + + + align:start position:0% +zero then the solution is not +unique suppose no so I want true or + + align:start position:0% +unique suppose no so I want true or + + + align:start position:0% +unique suppose no so I want true or +false and and a reason suppose this this + + align:start position:0% +false and and a reason suppose this this + + + align:start position:0% +false and and a reason suppose this this +combination is zero + + align:start position:0% +combination is zero + + + align:start position:0% +combination is zero +V1 minus V2 + + align:start position:0% +V1 minus V2 + + + align:start position:0% +V1 minus V2 +V3 show + + align:start position:0% +V3 show + + + align:start position:0% +V3 show +that what can what does that tell me so + + align:start position:0% +that what can what does that tell me so + + + align:start position:0% +that what can what does that tell me so +it's a separate question maybe I I sort + + align:start position:0% +it's a separate question maybe I I sort + + + align:start position:0% +it's a separate question maybe I I sort +of save time by writing it that way but + + align:start position:0% +of save time by writing it that way but + + + align:start position:0% +of save time by writing it that way but +it's a separate totally separate + + align:start position:0% +it's a separate totally separate + + + align:start position:0% +it's a separate totally separate +question if I know if I have a matrix + + align:start position:0% +question if I know if I have a matrix + + + align:start position:0% +question if I know if I have a matrix +and I know that column 1 minus column 2 + + align:start position:0% +and I know that column 1 minus column 2 + + + align:start position:0% +and I know that column 1 minus column 2 +plus column 3 is + + align:start position:0% +plus column 3 is + + + align:start position:0% +plus column 3 is +zero what does that tell me + + align:start position:0% +zero what does that tell me + + + align:start position:0% +zero what does that tell me +about whether the solution is unique or + + align:start position:0% +about whether the solution is unique or + + + align:start position:0% +about whether the solution is unique or +not + + align:start position:0% + + + + align:start position:0% + +could if is there are there are there is + + align:start position:0% +could if is there are there are there is + + + align:start position:0% +could if is there are there are there is +there more than one + + align:start position:0% +there more than one + + + align:start position:0% +there more than one +solution what what's uniqueness + + align:start position:0% +solution what what's uniqueness + + + align:start position:0% +solution what what's uniqueness +about uniqueness is about is there + + align:start position:0% +about uniqueness is about is there + + + align:start position:0% +about uniqueness is about is there +anything in the null space right the + + align:start position:0% +anything in the null space right the + + + align:start position:0% +anything in the null space right the +solution is unique when there's nobody + + align:start position:0% +solution is unique when there's nobody + + + align:start position:0% +solution is unique when there's nobody +in the null space except the zero vector + + align:start position:0% +in the null space except the zero vector + + + align:start position:0% +in the null space except the zero vector +and if that's + + align:start position:0% +and if that's + + + align:start position:0% +and if that's +zero then this guy would be in the null + + align:start position:0% +zero then this guy would be in the null + + + align:start position:0% +zero then this guy would be in the null +space so so then so if this were zero + + align:start position:0% +space so so then so if this were zero + + + align:start position:0% +space so so then so if this were zero +then then this x is in the null space of + + align:start position:0% +then then this x is in the null space of + + + align:start position:0% +then then this x is in the null space of +a so + + align:start position:0% +a so + + + align:start position:0% +a so +Solutions are + + align:start position:0% +Solutions are + + + align:start position:0% +Solutions are +never + + align:start position:0% + + + + align:start position:0% + +unique because I could always add that + + align:start position:0% +unique because I could always add that + + + align:start position:0% +unique because I could always add that +to any + + align:start position:0% +to any + + + align:start position:0% +to any +solution and it it and ax would wouldn't + + align:start position:0% +solution and it it and ax would wouldn't + + + align:start position:0% +solution and it it and ax would wouldn't +change so uh so always that question is + + align:start position:0% +change so uh so always that question is + + + align:start position:0% +change so uh so always that question is +there somebody in the null space okay + + align:start position:0% +there somebody in the null space okay + + + align:start position:0% +there somebody in the null space okay +third oh now here's a totally different + + align:start position:0% +third oh now here's a totally different + + + align:start position:0% +third oh now here's a totally different +question + + align:start position:0% +question + + + align:start position:0% +question +suppose those three vectors V1 V2 V3 are + + align:start position:0% +suppose those three vectors V1 V2 V3 are + + + align:start position:0% +suppose those three vectors V1 V2 V3 are +orthonormal so that's I mean they this + + align:start position:0% +orthonormal so that's I mean they this + + + align:start position:0% +orthonormal so that's I mean they this +isn't going to happen for orthonormal + + align:start position:0% +isn't going to happen for orthonormal + + + align:start position:0% +isn't going to happen for orthonormal +vectors okay so part C forget Part B C + + align:start position:0% +vectors okay so part C forget Part B C + + + align:start position:0% +vectors okay so part C forget Part B C +if V1 V2 V3 are orth + + align:start position:0% + + + + align:start position:0% + +normal + + align:start position:0% +normal + + + align:start position:0% +normal +orthonormal so that I would usually have + + align:start position:0% +orthonormal so that I would usually have + + + align:start position:0% +orthonormal so that I would usually have +called them q1 Q2 + + align:start position:0% + + + + align:start position:0% + +Q3 now what combination oh here's a nice + + align:start position:0% +Q3 now what combination oh here's a nice + + + align:start position:0% +Q3 now what combination oh here's a nice +question if I say so myself what + + align:start position:0% +question if I say so myself what + + + align:start position:0% +question if I say so myself what +combination of V1 and V2 is closest to + + align:start position:0% +combination of V1 and V2 is closest to + + + align:start position:0% +combination of V1 and V2 is closest to +V3 what point on the plane of V1 and V2 + + align:start position:0% +V3 what point on the plane of V1 and V2 + + + align:start position:0% +V3 what point on the plane of V1 and V2 +is the closest point to V3 if these + + align:start position:0% +is the closest point to V3 if these + + + align:start position:0% +is the closest point to V3 if these +vectors are orthonormal so let me I'll + + align:start position:0% +vectors are orthonormal so let me I'll + + + align:start position:0% +vectors are orthonormal so let me I'll +start the sentence then + + align:start position:0% +start the sentence then + + + align:start position:0% +start the sentence then +the + + align:start position:0% +the + + + align:start position:0% +the +combination something time V1 plus + + align:start position:0% +combination something time V1 plus + + + align:start position:0% +combination something time V1 plus +something * V2 is + + align:start position:0% +something * V2 is + + + align:start position:0% +something * V2 is +closest is the closest combination to + + align:start position:0% +closest is the closest combination to + + + align:start position:0% +closest is the closest combination to +V3 and what's the answer what's the + + align:start position:0% +V3 and what's the answer what's the + + + align:start position:0% +V3 and what's the answer what's the +what's the closest Vector on that plane + + align:start position:0% +what's the closest Vector on that plane + + + align:start position:0% +what's the closest Vector on that plane +to V3 + + align:start position:0% +to V3 + + + align:start position:0% +to V3 +zeros right we just imagine the + + align:start position:0% +zeros right we just imagine the + + + align:start position:0% +zeros right we just imagine the +XYZ X the V V1 V2 V3 could be the + + align:start position:0% +XYZ X the V V1 V2 V3 could be the + + + align:start position:0% +XYZ X the V V1 V2 V3 could be the +standard basis the + + align:start position:0% +standard basis the + + + align:start position:0% +standard basis the +XYZ vectors and of course the point on + + align:start position:0% +XYZ vectors and of course the point on + + + align:start position:0% +XYZ vectors and of course the point on +the XY plane that's closest to the to V3 + + align:start position:0% +the XY plane that's closest to the to V3 + + + align:start position:0% +the XY plane that's closest to the to V3 +on the z-axis is zero so so I if we're + + align:start position:0% +on the z-axis is zero so so I if we're + + + align:start position:0% +on the z-axis is zero so so I if we're +orthonormal then the projection + + align:start position:0% +orthonormal then the projection + + + align:start position:0% +orthonormal then the projection +of V3 onto that plane is it's it's + + align:start position:0% +of V3 onto that plane is it's it's + + + align:start position:0% +of V3 onto that plane is it's it's +perpendicular it hits right at zero okay + + align:start position:0% +perpendicular it hits right at zero okay + + + align:start position:0% +perpendicular it hits right at zero okay +so that's that's like a quick qu you + + align:start position:0% +so that's that's like a quick qu you + + + align:start position:0% +so that's that's like a quick qu you +know easy question but still brings it + + align:start position:0% +know easy question but still brings it + + + align:start position:0% +know easy question but still brings it +out okay um let let me see + + align:start position:0% +out okay um let let me see + + + align:start position:0% +out okay um let let me see +what + + align:start position:0% +what + + + align:start position:0% +what +um shall I write down + + align:start position:0% +um shall I write down + + + align:start position:0% +um shall I write down +a a yeah a Markoff Matrix + + align:start position:0% + + + + align:start position:0% + +tell and I'll I'll ask you for its igen + + align:start position:0% +tell and I'll I'll ask you for its igen + + + align:start position:0% +tell and I'll I'll ask you for its igen +values okay here's a Markoff + + align:start position:0% +values okay here's a Markoff + + + align:start position:0% +values okay here's a Markoff +Matrix this + + align:start position:0% + + + + align:start position:0% + +this and uh tell me it's ion + + align:start position:0% +this and uh tell me it's ion + + + align:start position:0% +this and uh tell me it's ion +values so here I'll call the Matrix a + + align:start position:0% +values so here I'll call the Matrix a + + + align:start position:0% +values so here I'll call the Matrix a +and I'll call the this is + + align:start position:0% + + + + align:start position:0% + +2.4.4 + + align:start position:0% + + + + align:start position:0% + +4.24 3.3.4 + + align:start position:0% + + + + align:start position:0% + +okay let's see it helps out by to notice + + align:start position:0% +okay let's see it helps out by to notice + + + align:start position:0% +okay let's see it helps out by to notice +that column + + align:start position:0% +that column + + + align:start position:0% +that column +1 plus column + + align:start position:0% +1 plus column + + + align:start position:0% +1 plus column +2 what's what what's interesting about + + align:start position:0% +2 what's what what's interesting about + + + align:start position:0% +2 what's what what's interesting about +column 1 plus column + + align:start position:0% +column 1 plus column + + + align:start position:0% +column 1 plus column +2 it's twice as much as column + + align:start position:0% +2 it's twice as much as column + + + align:start position:0% +2 it's twice as much as column +3 so column 1 plus column 2 equals 2 * + + align:start position:0% +3 so column 1 plus column 2 equals 2 * + + + align:start position:0% +3 so column 1 plus column 2 equals 2 * +column 3 I I put that in there column 1 + + align:start position:0% +column 3 I I put that in there column 1 + + + align:start position:0% +column 3 I I put that in there column 1 ++ column 2 equal twice column three + + align:start position:0% ++ column 2 equal twice column three + + + align:start position:0% ++ column 2 equal twice column three +that's a observation okay I want to tell + + align:start position:0% +that's a observation okay I want to tell + + + align:start position:0% +that's a observation okay I want to tell +me the IG values of the + + align:start position:0% + + + + align:start position:0% + +Matrix okay tell me one I + + align:start position:0% +Matrix okay tell me one I + + + align:start position:0% +Matrix okay tell me one I +value + + align:start position:0% +value + + + align:start position:0% +value +zero because the Matrix is singular tell + + align:start position:0% +zero because the Matrix is singular tell + + + align:start position:0% +zero because the Matrix is singular tell +me another ion value one because it's a + + align:start position:0% +me another ion value one because it's a + + + align:start position:0% +me another ion value one because it's a +Markoff + + align:start position:0% +Markoff + + + align:start position:0% +Markoff +Matrix The Columns add to the all ones + + align:start position:0% +Matrix The Columns add to the all ones + + + align:start position:0% +Matrix The Columns add to the all ones +vector and uh that will be a + + align:start position:0% +vector and uh that will be a + + + align:start position:0% +vector and uh that will be a +igen Vector of a transpose and tell me + + align:start position:0% +igen Vector of a transpose and tell me + + + align:start position:0% +igen Vector of a transpose and tell me +the third igen + + align:start position:0% + + + + align:start position:0% + +value let's see to make the trace come + + align:start position:0% +value let's see to make the trace come + + + align:start position:0% +value let's see to make the trace come +out right which is 8 we need minus + + align:start position:0% +out right which is 8 we need minus + + + align:start position:0% +out right which is 8 we need minus +point2 + + align:start position:0% +point2 + + + align:start position:0% +point2 +okay okay and + + align:start position:0% +okay okay and + + + align:start position:0% +okay okay and +now suppose I start the markof + + align:start position:0% +now suppose I start the markof + + + align:start position:0% +now suppose I start the markof +process suppose I start with a a mate + + align:start position:0% +process suppose I start with a a mate + + + align:start position:0% +process suppose I start with a a mate +with U of zero so I'm going to look at + + align:start position:0% +with U of zero so I'm going to look at + + + align:start position:0% +with U of zero so I'm going to look at +the I'm going to look at the powers of a + + align:start position:0% +the I'm going to look at the powers of a + + + align:start position:0% +the I'm going to look at the powers of a +applied to U of Z this is this is UK + + align:start position:0% +applied to U of Z this is this is UK + + + align:start position:0% +applied to U of Z this is this is UK +K and there's my Matrix and I'm going to + + align:start position:0% +K and there's my Matrix and I'm going to + + + align:start position:0% +K and there's my Matrix and I'm going to +let U of0 be this is going to be 010 + + align:start position:0% +let U of0 be this is going to be 010 + + + align:start position:0% +let U of0 be this is going to be 010 +0 and I I want to my question is what + + align:start position:0% +0 and I I want to my question is what + + + align:start position:0% +0 and I I want to my question is what +does that + + align:start position:0% +does that + + + align:start position:0% +does that +approach if if U of zero is equal to + + align:start position:0% +approach if if U of zero is equal to + + + align:start position:0% +approach if if U of zero is equal to +this if there's U of Z shall I write it + + align:start position:0% +this if there's U of Z shall I write it + + + align:start position:0% +this if there's U of Z shall I write it +in maybe I'll just write in U of Z + + align:start position:0% + + + + align:start position:0% + +a to the K starting with + + align:start position:0% +a to the K starting with + + + align:start position:0% +a to the K starting with +10 people in state + + align:start position:0% + + + + align:start position:0% + +two + + align:start position:0% +two + + + align:start position:0% +two +and every step follows the Markoff rule + + align:start position:0% +and every step follows the Markoff rule + + + align:start position:0% +and every step follows the Markoff rule +what's the what's the what what does the + + align:start position:0% +what's the what's the what what does the + + + align:start position:0% +what's the what's the what what does the +solution look like after K steps let me + + align:start position:0% +solution look like after K steps let me + + + align:start position:0% +solution look like after K steps let me +just ask you that and then what happens + + align:start position:0% +just ask you that and then what happens + + + align:start position:0% +just ask you that and then what happens +as K goes to Infinity this is a steady + + align:start position:0% +as K goes to Infinity this is a steady + + + align:start position:0% +as K goes to Infinity this is a steady +state question right I'm looking for the + + align:start position:0% +state question right I'm looking for the + + + align:start position:0% +state question right I'm looking for the +steady state actually the question + + align:start position:0% +steady state actually the question + + + align:start position:0% +steady state actually the question +doesn't ask for the kstep answer it just + + align:start position:0% +doesn't ask for the kstep answer it just + + + align:start position:0% +doesn't ask for the kstep answer it just +jumps right away to Infinity but how + + align:start position:0% +jumps right away to Infinity but how + + + align:start position:0% +jumps right away to Infinity but how +would I express the solution after K + + align:start position:0% +would I express the solution after K + + + align:start position:0% +would I express the solution after K +steps it would be some + + align:start position:0% +steps it would be some + + + align:start position:0% +steps it would be some +multiple of the first igon + + align:start position:0% +multiple of the first igon + + + align:start position:0% +multiple of the first igon +value times the first to the case power + + align:start position:0% +value times the first to the case power + + + align:start position:0% +value times the first to the case power +times the first igon Vector plus some + + align:start position:0% +times the first igon Vector plus some + + + align:start position:0% +times the first igon Vector plus some +other multip Le of the second IG value + + align:start position:0% +other multip Le of the second IG value + + + align:start position:0% +other multip Le of the second IG value +times its IG vector and some multiple of + + align:start position:0% +times its IG vector and some multiple of + + + align:start position:0% +times its IG vector and some multiple of +the third IG value time its igen + + align:start position:0% +the third IG value time its igen + + + align:start position:0% +the third IG value time its igen +Vector okay + + align:start position:0% +Vector okay + + + align:start position:0% +Vector okay +good and these igen values are + + align:start position:0% +good and these igen values are + + + align:start position:0% +good and these igen values are +0 1 and minus + + align:start position:0% + + + + align:start position:0% + +point2 so what happens as K goes to + + align:start position:0% +point2 so what happens as K goes to + + + align:start position:0% +point2 so what happens as K goes to +Infinity + + align:start position:0% + + + + align:start position:0% + +the only thing that survives the steady + + align:start position:0% +the only thing that survives the steady + + + align:start position:0% +the only thing that survives the steady +state so at at U + + align:start position:0% + + + + align:start position:0% + +Infinity this is gone this is gone all + + align:start position:0% +Infinity this is gone this is gone all + + + align:start position:0% +Infinity this is gone this is gone all +that's left is C2 + + align:start position:0% + + + + align:start position:0% + +X2 so I better find + + align:start position:0% +X2 so I better find + + + align:start position:0% +X2 so I better find +X2 I've got to find that igen Vector to + + align:start position:0% +X2 I've got to find that igen Vector to + + + align:start position:0% +X2 I've got to find that igen Vector to +complete the answer what's the IG Vector + + align:start position:0% +complete the answer what's the IG Vector + + + align:start position:0% +complete the answer what's the IG Vector +that corresponds to Lambda equal 1 + + align:start position:0% +that corresponds to Lambda equal 1 + + + align:start position:0% +that corresponds to Lambda equal 1 +that's the the key IG vector in any + + align:start position:0% +that's the the key IG vector in any + + + align:start position:0% +that's the the key IG vector in any +markof process is that igen + + align:start position:0% +markof process is that igen + + + align:start position:0% +markof process is that igen +Vector Lambda equal 1 is an igen value I + + align:start position:0% +Vector Lambda equal 1 is an igen value I + + + align:start position:0% +Vector Lambda equal 1 is an igen value I +need its igen Vector + + align:start position:0% +need its igen Vector + + + align:start position:0% +need its igen Vector +X2 and then I need to know how much of + + align:start position:0% +X2 and then I need to know how much of + + + align:start position:0% +X2 and then I need to know how much of +it is in the starting Vector + + align:start position:0% +it is in the starting Vector + + + align:start position:0% +it is in the starting Vector +U okay so how do I find that igen Vector + + align:start position:0% +U okay so how do I find that igen Vector + + + align:start position:0% +U okay so how do I find that igen Vector +I guess I subtract one from the diagonal + + align:start position:0% +I guess I subtract one from the diagonal + + + align:start position:0% +I guess I subtract one from the diagonal +right so I have + + align:start position:0% +right so I have + + + align:start position:0% +right so I have +minus8 + + align:start position:0% +minus8 + + + align:start position:0% +minus8 +-8 + + align:start position:0% +-8 + + + align:start position:0% +-8 +-.6 and the rest of course is just still + + align:start position:0% +-.6 and the rest of course is just still + + + align:start position:0% +-.6 and the rest of course is just still +4.4 + + align:start position:0% +4.4 + + + align:start position:0% +4.4 +4.4 + + align:start position:0% +4.4 + + + align:start position:0% +4.4 +3.3 and hopefully that's a singular + + align:start position:0% +3.3 and hopefully that's a singular + + + align:start position:0% +3.3 and hopefully that's a singular +Matrix so I'm looking to + + align:start position:0% +Matrix so I'm looking to + + + align:start position:0% +Matrix so I'm looking to +solve a minus I equal + + align:start position:0% +solve a minus I equal + + + align:start position:0% +solve a minus I equal +the a minus i x equals z let's see can + + align:start position:0% +the a minus i x equals z let's see can + + + align:start position:0% +the a minus i x equals z let's see can +anybody spot the solution here I don't + + align:start position:0% +anybody spot the solution here I don't + + + align:start position:0% +anybody spot the solution here I don't +know I didn't make it easy for + + align:start position:0% +know I didn't make it easy for + + + align:start position:0% +know I didn't make it easy for +myself um what do you think + + align:start position:0% +myself um what do you think + + + align:start position:0% +myself um what do you think +there maybe those since those I'm just + + align:start position:0% +there maybe those since those I'm just + + + align:start position:0% +there maybe those since those I'm just +thinking aloud here those first let me + + align:start position:0% +thinking aloud here those first let me + + + align:start position:0% +thinking aloud here those first let me +let me guess those first two entries + + align:start position:0% +let me guess those first two entries + + + align:start position:0% +let me guess those first two entries +might be oh no what do you think any + + align:start position:0% +might be oh no what do you think any + + + align:start position:0% +might be oh no what do you think any +anybody see + + align:start position:0% +anybody see + + + align:start position:0% +anybody see +it we could use elimination if we were + + align:start position:0% +it we could use elimination if we were + + + align:start position:0% +it we could use elimination if we were +desperate are we that + + align:start position:0% +desperate are we that + + + align:start position:0% +desperate are we that +desperate anybody just call out if you + + align:start position:0% +desperate anybody just call out if you + + + align:start position:0% +desperate anybody just call out if you +see the vector here that's in that null + + align:start position:0% +see the vector here that's in that null + + + align:start position:0% +see the vector here that's in that null +space + + align:start position:0% +space + + + align:start position:0% +space +there better be a vector in that null + + align:start position:0% +there better be a vector in that null + + + align:start position:0% +there better be a vector in that null +space or I'm + + align:start position:0% + + + + align:start position:0% + +quitting + + align:start position:0% +quitting + + + align:start position:0% +quitting +uh okay well I guess we could use + + align:start position:0% +uh okay well I guess we could use + + + align:start position:0% +uh okay well I guess we could use +elimination + + align:start position:0% +elimination + + + align:start position:0% +elimination +seems I thought maybe somebody might see + + align:start position:0% +seems I thought maybe somebody might see + + + align:start position:0% +seems I thought maybe somebody might see +it from further away + + align:start position:0% +it from further away + + + align:start position:0% +it from further away +uh you think is there a chance that + + align:start position:0% +uh you think is there a chance that + + + align:start position:0% +uh you think is there a chance that +these guys are could it be that these + + align:start position:0% +these guys are could it be that these + + + align:start position:0% +these guys are could it be that these +these two are equal and this is whatever + + align:start position:0% +these two are equal and this is whatever + + + align:start position:0% +these two are equal and this is whatever +it takes like something like + + align:start position:0% +it takes like something like + + + align:start position:0% +it takes like something like +332 would that possibly work I mean + + align:start position:0% +332 would that possibly work I mean + + + align:start position:0% +332 would that possibly work I mean +that's great for this no it's not that + + align:start position:0% +that's great for this no it's not that + + + align:start position:0% +that's great for this no it's not that +great + + align:start position:0% +great + + + align:start position:0% +great +334 this is uh deeper mathematics you're + + align:start position:0% +334 this is uh deeper mathematics you're + + + align:start position:0% +334 this is uh deeper mathematics you're +watching now 334 that is + + align:start position:0% +watching now 334 that is + + + align:start position:0% +watching now 334 that is +that it works don't don't mess with it + + align:start position:0% +that it works don't don't mess with it + + + align:start position:0% +that it works don't don't mess with it +it + + align:start position:0% +it + + + align:start position:0% +it +works yeah okay it works all right and + + align:start position:0% +works yeah okay it works all right and + + + align:start position:0% +works yeah okay it works all right and +yes okay and uh so that 6 2 + + align:start position:0% + + + + align:start position:0% + +334 and uh how much of that Vector is + + align:start position:0% +334 and uh how much of that Vector is + + + align:start position:0% +334 and uh how much of that Vector is +in is in the starting + + align:start position:0% +in is in the starting + + + align:start position:0% +in is in the starting +Vector well we could go we could go + + align:start position:0% +Vector well we could go we could go + + + align:start position:0% +Vector well we could go we could go +through a complicated process but what's + + align:start position:0% +through a complicated process but what's + + + align:start position:0% +through a complicated process but what's +the beauty of markof things that that + + align:start position:0% +the beauty of markof things that that + + + align:start position:0% +the beauty of markof things that that +the total number of the total population + + align:start position:0% +the total number of the total population + + + align:start position:0% +the total number of the total population +that the the the sum of these doesn't + + align:start position:0% +that the the the sum of these doesn't + + + align:start position:0% +that the the the sum of these doesn't +change the the total number of people + + align:start position:0% +change the the total number of people + + + align:start position:0% +change the the total number of people +they're moving around but they + + align:start position:0% +they're moving around but they + + + align:start position:0% +they're moving around but they +don't get born or or or or get dead so + + align:start position:0% +don't get born or or or or get dead so + + + align:start position:0% +don't get born or or or or get dead so +so there's 10 of them at the start so + + align:start position:0% +so there's 10 of them at the start so + + + align:start position:0% +so there's 10 of them at the start so +there's 10 of them there so C2 is + + align:start position:0% +there's 10 of them there so C2 is + + + align:start position:0% +there's 10 of them there so C2 is +actually one yeah so that would be the + + align:start position:0% +actually one yeah so that would be the + + + align:start position:0% +actually one yeah so that would be the +the correct correct solution okay that + + align:start position:0% +the correct correct solution okay that + + + align:start position:0% +the correct correct solution okay that +would be the U + + align:start position:0% +would be the U + + + align:start position:0% +would be the U +Infinity okay so I use there in that + + align:start position:0% +Infinity okay so I use there in that + + + align:start position:0% +Infinity okay so I use there in that +process sort of the main facts about + + align:start position:0% +process sort of the main facts about + + + align:start position:0% +process sort of the main facts about +Markoff matrices to uh to get a jump on + + align:start position:0% +Markoff matrices to uh to get a jump on + + + align:start position:0% +Markoff matrices to uh to get a jump on +the uh answer + + align:start position:0% +the uh answer + + + align:start position:0% +the uh answer +okay um let's see okay here's some uh + + align:start position:0% +okay um let's see okay here's some uh + + + align:start position:0% +okay um let's see okay here's some uh +kind of quick short + + align:start position:0% +kind of quick short + + + align:start position:0% +kind of quick short +questions uh maybe I I'll move over to + + align:start position:0% +questions uh maybe I I'll move over to + + + align:start position:0% +questions uh maybe I I'll move over to +this board and leave that for the + + align:start position:0% +this board and leave that for the + + + align:start position:0% +this board and leave that for the +moment I'm looking for 2 by two + + align:start position:0% +moment I'm looking for 2 by two + + + align:start position:0% +moment I'm looking for 2 by two +matrices and I'll read out the property + + align:start position:0% +matrices and I'll read out the property + + + align:start position:0% +matrices and I'll read out the property +I want and you give me an example or + + align:start position:0% +I want and you give me an example or + + + align:start position:0% +I want and you give me an example or +tell me there isn't such a + + align:start position:0% +tell me there isn't such a + + + align:start position:0% +tell me there isn't such a +matrix all right here we go first so 2 + + align:start position:0% +matrix all right here we go first so 2 + + + align:start position:0% +matrix all right here we go first so 2 +by tws + + align:start position:0% +by tws + + + align:start position:0% +by tws +first I want to project I want the + + align:start position:0% +first I want to project I want the + + + align:start position:0% +first I want to project I want the +projection projection onto the line + + align:start position:0% +projection projection onto the line + + + align:start position:0% +projection projection onto the line +through a = 4 - + + align:start position:0% + + + + align:start position:0% + +3 so it's a one 1D a one-dimensional + + align:start position:0% +3 so it's a one 1D a one-dimensional + + + align:start position:0% +3 so it's a one 1D a one-dimensional +projection Matrix I'm looking + + align:start position:0% + + + + align:start position:0% + +for and what's the formula for it for + + align:start position:0% +for and what's the formula for it for + + + align:start position:0% +for and what's the formula for it for +what's the formula for the projection + + align:start position:0% +what's the formula for the projection + + + align:start position:0% +what's the formula for the projection +ction Matrix P onto a line through a and + + align:start position:0% +ction Matrix P onto a line through a and + + + align:start position:0% +ction Matrix P onto a line through a and +then we'll just plug in this particular + + align:start position:0% +then we'll just plug in this particular + + + align:start position:0% +then we'll just plug in this particular +a you remember that + + align:start position:0% +a you remember that + + + align:start position:0% +a you remember that +formula there's an A and an a + + align:start position:0% +formula there's an A and an a + + + align:start position:0% +formula there's an A and an a +transpose and we can normally we would + + align:start position:0% +transpose and we can normally we would + + + align:start position:0% +transpose and we can normally we would +have an A transpose a inverse in the + + align:start position:0% +have an A transpose a inverse in the + + + align:start position:0% +have an A transpose a inverse in the +middle but here we just got numbers so + + align:start position:0% +middle but here we just got numbers so + + + align:start position:0% +middle but here we just got numbers so +we just divide by + + align:start position:0% +we just divide by + + + align:start position:0% +we just divide by +it and then plug in a and we've got + + align:start position:0% +it and then plug in a and we've got + + + align:start position:0% +it and then plug in a and we've got +it okay so equals + + align:start position:0% +it okay so equals + + + align:start position:0% +it okay so equals +you can put in the numbers trivial right + + align:start position:0% +you can put in the numbers trivial right + + + align:start position:0% +you can put in the numbers trivial right +okay number two the Matrix + + align:start position:0% +okay number two the Matrix + + + align:start position:0% +okay number two the Matrix +that has igen value zero so this is a + + align:start position:0% +that has igen value zero so this is a + + + align:start position:0% +that has igen value zero so this is a +new problem The Matrix with igen value 0 + + align:start position:0% +new problem The Matrix with igen value 0 + + + align:start position:0% +new problem The Matrix with igen value 0 +and + + align:start position:0% +and + + + align:start position:0% +and +three and I vectors well let me write + + align:start position:0% +three and I vectors well let me write + + + align:start position:0% +three and I vectors well let me write +these down I value zero I Vector one + + align:start position:0% +these down I value zero I Vector one + + + align:start position:0% +these down I value zero I Vector one +two I value three I Vector 2 one + + align:start position:0% + + + + align:start position:0% + +I'm giving you the igen values and IG + + align:start position:0% +I'm giving you the igen values and IG + + + align:start position:0% +I'm giving you the igen values and IG +vectors instead of asking for them now + + align:start position:0% +vectors instead of asking for them now + + + align:start position:0% +vectors instead of asking for them now +I'm asking for the + + align:start position:0% + + + + align:start position:0% + +Matrix what's what's the Matrix then + + align:start position:0% +Matrix what's what's the Matrix then + + + align:start position:0% +Matrix what's what's the Matrix then +what's + + align:start position:0% + + + + align:start position:0% + +a what's here was a formula then we just + + align:start position:0% +a what's here was a formula then we just + + + align:start position:0% +a what's here was a formula then we just +put in some numbers what's the formula + + align:start position:0% +put in some numbers what's the formula + + + align:start position:0% +put in some numbers what's the formula +here into which we'll just put the given + + align:start position:0% +here into which we'll just put the given + + + align:start position:0% +here into which we'll just put the given +numbers it's the s Lambda s inverse + + align:start position:0% +numbers it's the s Lambda s inverse + + + align:start position:0% +numbers it's the s Lambda s inverse +right so it's s which is this IG Vector + + align:start position:0% +right so it's s which is this IG Vector + + + align:start position:0% +right so it's s which is this IG Vector +matrix it's the Lambda which is the IG + + align:start position:0% +matrix it's the Lambda which is the IG + + + align:start position:0% +matrix it's the Lambda which is the IG +value + + align:start position:0% +value + + + align:start position:0% +value +matrix it's the S inverse whatever that + + align:start position:0% +matrix it's the S inverse whatever that + + + align:start position:0% +matrix it's the S inverse whatever that +turns out to be let me just leave it as + + align:start position:0% + + + + align:start position:0% + +inverse that has to be it + + align:start position:0% +inverse that has to be it + + + align:start position:0% +inverse that has to be it +right because if we went in the other + + align:start position:0% +right because if we went in the other + + + align:start position:0% +right because if we went in the other +direction that Matrix S would + + align:start position:0% +direction that Matrix S would + + + align:start position:0% +direction that Matrix S would +diagonalize a to produce Lambda so it's + + align:start position:0% +diagonalize a to produce Lambda so it's + + + align:start position:0% +diagonalize a to produce Lambda so it's +s Lambda s inverse good okay ready for + + align:start position:0% +s Lambda s inverse good okay ready for + + + align:start position:0% +s Lambda s inverse good okay ready for +number three a real Matrix that cannot + + align:start position:0% +number three a real Matrix that cannot + + + align:start position:0% +number three a real Matrix that cannot +be factored + + align:start position:0% +be factored + + + align:start position:0% +be factored +into a I'm looking for a matrix a that + + align:start position:0% +into a I'm looking for a matrix a that + + + align:start position:0% +into a I'm looking for a matrix a that +doesn't that never could equal B + + align:start position:0% +doesn't that never could equal B + + + align:start position:0% +doesn't that never could equal B +transpose B for any + + align:start position:0% + + + + align:start position:0% + +b a 2X two Matrix that could not be + + align:start position:0% +b a 2X two Matrix that could not be + + + align:start position:0% +b a 2X two Matrix that could not be +factored in the form B transpose + + align:start position:0% +factored in the form B transpose + + + align:start position:0% +factored in the form B transpose +B so all you have to do is think well + + align:start position:0% +B so all you have to do is think well + + + align:start position:0% +B so all you have to do is think well +what does B transpose B look like and + + align:start position:0% +what does B transpose B look like and + + + align:start position:0% +what does B transpose B look like and +then pick something + + align:start position:0% +then pick something + + + align:start position:0% +then pick something +different what what do you + + align:start position:0% + + + + align:start position:0% + +suggest uh let's see what what what + + align:start position:0% +suggest uh let's see what what what + + + align:start position:0% +suggest uh let's see what what what +should we take for a matrix that could + + align:start position:0% +should we take for a matrix that could + + + align:start position:0% +should we take for a matrix that could +not be could not have this Form bpos B + + align:start position:0% +not be could not have this Form bpos B + + + align:start position:0% +not be could not have this Form bpos B +well what do we know about bpos B it's + + align:start position:0% +well what do we know about bpos B it's + + + align:start position:0% +well what do we know about bpos B it's +always symmetric so just give me any + + align:start position:0% +always symmetric so just give me any + + + align:start position:0% +always symmetric so just give me any +non-symmetric Matrix it couldn't + + align:start position:0% +non-symmetric Matrix it couldn't + + + align:start position:0% +non-symmetric Matrix it couldn't +possibly have that for form okay and let + + align:start position:0% +possibly have that for form okay and let + + + align:start position:0% +possibly have that for form okay and let +me ask the fourth part of this question + + align:start position:0% +me ask the fourth part of this question + + + align:start position:0% +me ask the fourth part of this question +a matrix that + + align:start position:0% +a matrix that + + + align:start position:0% +a matrix that +has orthogonal igen vectors but it's not + + align:start position:0% +has orthogonal igen vectors but it's not + + + align:start position:0% +has orthogonal igen vectors but it's not +symmetric tell me a matrix How could a + + align:start position:0% +symmetric tell me a matrix How could a + + + align:start position:0% +symmetric tell me a matrix How could a +matrix what matrices have orthogonal ion + + align:start position:0% +matrix what matrices have orthogonal ion + + + align:start position:0% +matrix what matrices have orthogonal ion +vectors but they're not symmetric + + align:start position:0% + + + + align:start position:0% + +matrices what other matrices tell me a + + align:start position:0% +matrices what other matrices tell me a + + + align:start position:0% +matrices what other matrices tell me a +different other families of matrices + + align:start position:0% +different other families of matrices + + + align:start position:0% +different other families of matrices +that have orthogonal ien vectors + + align:start position:0% +that have orthogonal ien vectors + + + align:start position:0% +that have orthogonal ien vectors +we know symmetric matrices do but but + + align:start position:0% +we know symmetric matrices do but but + + + align:start position:0% +we know symmetric matrices do but but +others + + align:start position:0% +others + + + align:start position:0% +others +also so so I'm looking for + + align:start position:0% + + + + align:start position:0% + +orthogonal I can + + align:start position:0% +orthogonal I can + + + align:start position:0% +orthogonal I can +vectors and what do you + + align:start position:0% + + + + align:start position:0% + +suggest uh The Matrix could be skew + + align:start position:0% +suggest uh The Matrix could be skew + + + align:start position:0% +suggest uh The Matrix could be skew +symmetric it could be an orthogonal + + align:start position:0% +symmetric it could be an orthogonal + + + align:start position:0% +symmetric it could be an orthogonal +Matrix so I I it it could be symmetric + + align:start position:0% +Matrix so I I it it could be symmetric + + + align:start position:0% +Matrix so I I it it could be symmetric +but but that was too easy so I Ruled + + align:start position:0% +but but that was too easy so I Ruled + + + align:start position:0% +but but that was too easy so I Ruled +that out it could be skew + + align:start position:0% +that out it could be skew + + + align:start position:0% +that out it could be skew +symmetric + + align:start position:0% +symmetric + + + align:start position:0% +symmetric +like like uh 1 minus one like + + align:start position:0% +like like uh 1 minus one like + + + align:start position:0% +like like uh 1 minus one like +that or it could be an orthogonal + + align:start position:0% +that or it could be an orthogonal + + + align:start position:0% +that or it could be an orthogonal +Matrix it could be an orthogonal Matrix + + align:start position:0% +Matrix it could be an orthogonal Matrix + + + align:start position:0% +Matrix it could be an orthogonal Matrix +like cosine s minus sin cosine all those + + align:start position:0% +like cosine s minus sin cosine all those + + + align:start position:0% +like cosine s minus sin cosine all those +matrices would have + + align:start position:0% +matrices would have + + + align:start position:0% +matrices would have +complex orthogonal + + align:start position:0% +complex orthogonal + + + align:start position:0% +complex orthogonal +igen + + align:start position:0% +igen + + + align:start position:0% +igen +vectors but they would be + + align:start position:0% +vectors but they would be + + + align:start position:0% +vectors but they would be +orthogonal and so those those examples + + align:start position:0% +orthogonal and so those those examples + + + align:start position:0% +orthogonal and so those those examples +are fine okay we can continue a little + + align:start position:0% +are fine okay we can continue a little + + + align:start position:0% +are fine okay we can continue a little +longer if you would like to uh um with + + align:start position:0% +longer if you would like to uh um with + + + align:start position:0% +longer if you would like to uh um with +uh + + align:start position:0% +uh + + + align:start position:0% +uh +um these from this from this exam from + + align:start position:0% +um these from this from this exam from + + + align:start position:0% +um these from this from this exam from +these exams least + + align:start position:0% + + + + align:start position:0% + +squares okay here's a least squares + + align:start position:0% +squares okay here's a least squares + + + align:start position:0% +squares okay here's a least squares +problem in which to make life quick + + align:start position:0% +problem in which to make life quick + + + align:start position:0% +problem in which to make life quick +I've given the answer it's it's like + + align:start position:0% +I've given the answer it's it's like + + + align:start position:0% +I've given the answer it's it's like +Jeopardy right uh I I just give the + + align:start position:0% +Jeopardy right uh I I just give the + + + align:start position:0% +Jeopardy right uh I I just give the +answer and you give the question + + align:start position:0% +answer and you give the question + + + align:start position:0% +answer and you give the question +okay oops + + align:start position:0% +okay oops + + + align:start position:0% +okay oops +we've sorry I'll let's see can I stay + + align:start position:0% +we've sorry I'll let's see can I stay + + + align:start position:0% +we've sorry I'll let's see can I stay +over here for the for the uh next + + align:start position:0% + + + + align:start position:0% + +question okay least Square so I'm I'm + + align:start position:0% +question okay least Square so I'm I'm + + + align:start position:0% +question okay least Square so I'm I'm +giving you the problem 11 1 012 2 + + align:start position:0% +giving you the problem 11 1 012 2 + + + align:start position:0% +giving you the problem 11 1 012 2 +CD equal + + align:start position:0% +CD equal + + + align:start position:0% +CD equal +341 and that's B of course this is axal + + align:start position:0% +341 and that's B of course this is axal + + + align:start position:0% +341 and that's B of course this is axal +B and the least Square solution so may I + + align:start position:0% +B and the least Square solution so may I + + + align:start position:0% +B and the least Square solution so may I +put C hat D hat to emphasize it's not + + align:start position:0% +put C hat D hat to emphasize it's not + + + align:start position:0% +put C hat D hat to emphasize it's not +the true solution has Le so the least + + align:start position:0% +the true solution has Le so the least + + + align:start position:0% +the true solution has Le so the least +Square solution maybe I should the hats + + align:start position:0% +Square solution maybe I should the hats + + + align:start position:0% +Square solution maybe I should the hats +really go here is 11/3 and minus1 + + align:start position:0% +really go here is 11/3 and minus1 + + + align:start position:0% +really go here is 11/3 and minus1 +of course you could have figured that + + align:start position:0% +of course you could have figured that + + + align:start position:0% +of course you could have figured that +out in no time so this year I'll ask you + + align:start position:0% +out in no time so this year I'll ask you + + + align:start position:0% +out in no time so this year I'll ask you +to do it probably but suppose we're + + align:start position:0% +to do it probably but suppose we're + + + align:start position:0% +to do it probably but suppose we're +given the + + align:start position:0% +given the + + + align:start position:0% +given the +answer then let's just remember what + + align:start position:0% +answer then let's just remember what + + + align:start position:0% +answer then let's just remember what +what happened what is the pro okay good + + align:start position:0% +what happened what is the pro okay good + + + align:start position:0% +what happened what is the pro okay good +question what's the projection P of this + + align:start position:0% +question what's the projection P of this + + + align:start position:0% +question what's the projection P of this +Vector onto the column space of that + + align:start position:0% +Vector onto the column space of that + + + align:start position:0% +Vector onto the column space of that +Matrix what's so so I write that + + align:start position:0% +Matrix what's so so I write that + + + align:start position:0% +Matrix what's so so I write that +question down + + align:start position:0% +question down + + + align:start position:0% +question down +one what is p the + + align:start position:0% +one what is p the + + + align:start position:0% +one what is p the +projection the projection of + + align:start position:0% +projection the projection of + + + align:start position:0% +projection the projection of +B + + align:start position:0% +B + + + align:start position:0% +B +onto the column space of + + align:start position:0% +onto the column space of + + + align:start position:0% +onto the column space of +a is + + align:start position:0% + + + + align:start position:0% + +what hopefully that's what the least + + align:start position:0% +what hopefully that's what the least + + + align:start position:0% +what hopefully that's what the least +squares problem + + align:start position:0% +squares problem + + + align:start position:0% +squares problem +solved what is + + align:start position:0% +solved what is + + + align:start position:0% +solved what is +it it's this was the best solution this + + align:start position:0% +it it's this was the best solution this + + + align:start position:0% +it it's this was the best solution this +it it's + + align:start position:0% +it it's + + + align:start position:0% +it it's +11/3 time * column + + align:start position:0% +11/3 time * column + + + align:start position:0% +11/3 time * column +1 plus or rather minus one time column 2 + + align:start position:0% +1 plus or rather minus one time column 2 + + + align:start position:0% +1 plus or rather minus one time column 2 +right that's what these squares did it + + align:start position:0% +right that's what these squares did it + + + align:start position:0% +right that's what these squares did it +found the combination of the columns + + align:start position:0% +found the combination of the columns + + + align:start position:0% +found the combination of the columns +that was as close as possible to be + + align:start position:0% +that was as close as possible to be + + + align:start position:0% +that was as close as possible to be +that's what Le squares was doing it + + align:start position:0% +that's what Le squares was doing it + + + align:start position:0% +that's what Le squares was doing it +found the projection okay + + align:start position:0% +found the projection okay + + + align:start position:0% +found the projection okay +secondly draw the straight line problem + + align:start position:0% +secondly draw the straight line problem + + + align:start position:0% +secondly draw the straight line problem +that corresponds to this system + + align:start position:0% +that corresponds to this system + + + align:start position:0% +that corresponds to this system +so I guess that the straight line + + align:start position:0% +so I guess that the straight line + + + align:start position:0% +so I guess that the straight line +straight line fitting a straight line + + align:start position:0% +straight line fitting a straight line + + + align:start position:0% +straight line fitting a straight line +problem uh we kind of recognize we + + align:start position:0% +problem uh we kind of recognize we + + + align:start position:0% +problem uh we kind of recognize we +recognize these are the Heights and + + align:start position:0% +recognize these are the Heights and + + + align:start position:0% +recognize these are the Heights and +these are the points so at 012 the + + align:start position:0% +these are the points so at 012 the + + + align:start position:0% +these are the points so at 012 the +heights are + + align:start position:0% +heights are + + + align:start position:0% +heights are +three and at at t equal to one the + + align:start position:0% +three and at at t equal to one the + + + align:start position:0% +three and at at t equal to one the +height is 4 1 2 3 4 and tal to 2 the + + align:start position:0% +height is 4 1 2 3 4 and tal to 2 the + + + align:start position:0% +height is 4 1 2 3 4 and tal to 2 the +height is + + align:start position:0% +height is + + + align:start position:0% +height is +one so I'm trying to fix the + + align:start position:0% +one so I'm trying to fix the + + + align:start position:0% +one so I'm trying to fix the +best straight line through those + + align:start position:0% +best straight line through those + + + align:start position:0% +best straight line through those +points + + align:start position:0% +points + + + align:start position:0% +points +God uh I could fit a triangle very well + + align:start position:0% +God uh I could fit a triangle very well + + + align:start position:0% +God uh I could fit a triangle very well +but uh uh where's the best I don't even + + align:start position:0% +but uh uh where's the best I don't even + + + align:start position:0% +but uh uh where's the best I don't even +know which way the best straight line + + align:start position:0% +know which way the best straight line + + + align:start position:0% +know which way the best straight line +goes maybe it goes oh I do know how it + + align:start position:0% +goes maybe it goes oh I do know how it + + + align:start position:0% +goes maybe it goes oh I do know how it +goes because there's the answer yes uh + + align:start position:0% +goes because there's the answer yes uh + + + align:start position:0% +goes because there's the answer yes uh +it it has it has a height + + align:start position:0% +it it has it has a height + + + align:start position:0% +it it has it has a height +11/3 and it has slope minus one so it's + + align:start position:0% +11/3 and it has slope minus one so it's + + + align:start position:0% +11/3 and it has slope minus one so it's +something like that okay great now + + align:start position:0% +something like that okay great now + + + align:start position:0% +something like that okay great now +finally and this completes the + + align:start position:0% +finally and this completes the + + + align:start position:0% +finally and this completes the +course find a vector a different Vector + + align:start position:0% +course find a vector a different Vector + + + align:start position:0% +course find a vector a different Vector +B not all zeros for which the least + + align:start position:0% +B not all zeros for which the least + + + align:start position:0% +B not all zeros for which the least +Square solution would be zero so I want + + align:start position:0% +Square solution would be zero so I want + + + align:start position:0% +Square solution would be zero so I want +you to find a different + + align:start position:0% +you to find a different + + + align:start position:0% +you to find a different +B so that the least Square solution + + align:start position:0% +B so that the least Square solution + + + align:start position:0% +B so that the least Square solution +changes to all zeros + + align:start position:0% + + + + align:start position:0% + +so tell me what I'm really looking for + + align:start position:0% +so tell me what I'm really looking for + + + align:start position:0% +so tell me what I'm really looking for +here I'm looking for a b where the best + + align:start position:0% +here I'm looking for a b where the best + + + align:start position:0% +here I'm looking for a b where the best +combination of these two columns is the + + align:start position:0% +combination of these two columns is the + + + align:start position:0% +combination of these two columns is the +zero + + align:start position:0% +zero + + + align:start position:0% +zero +combination so what kind of a vector B + + align:start position:0% +combination so what kind of a vector B + + + align:start position:0% +combination so what kind of a vector B +am I looking for I'm looking for a + + align:start position:0% +am I looking for I'm looking for a + + + align:start position:0% +am I looking for I'm looking for a +vector B that's orthogonal to those + + align:start position:0% +vector B that's orthogonal to those + + + align:start position:0% +vector B that's orthogonal to those +columns it's orthogonal to those columns + + align:start position:0% +columns it's orthogonal to those columns + + + align:start position:0% +columns it's orthogonal to those columns +it's orthogonal to the column space the + + align:start position:0% +it's orthogonal to the column space the + + + align:start position:0% +it's orthogonal to the column space the +best possible answer is zero so a vector + + align:start position:0% +best possible answer is zero so a vector + + + align:start position:0% +best possible answer is zero so a vector +B that's orth to those columns let's see + + align:start position:0% +B that's orth to those columns let's see + + + align:start position:0% +B that's orth to those columns let's see +maybe maybe uh one of those minus two of + + align:start position:0% +maybe maybe uh one of those minus two of + + + align:start position:0% +maybe maybe uh one of those minus two of +those and one of those that would be + + align:start position:0% +those and one of those that would be + + + align:start position:0% +those and one of those that would be +orthogonal to those columns and the best + + align:start position:0% +orthogonal to those columns and the best + + + align:start position:0% +orthogonal to those columns and the best +Vector would be 0 + + align:start position:0% +Vector would be 0 + + + align:start position:0% +Vector would be 0 +0 okay so that's as many questions as I + + align:start position:0% +0 okay so that's as many questions as I + + + align:start position:0% +0 okay so that's as many questions as I +can do in an hour but you get three + + align:start position:0% +can do in an hour but you get three + + + align:start position:0% +can do in an hour but you get three +hours and uh let me just say as I've + + align:start position:0% +hours and uh let me just say as I've + + + align:start position:0% +hours and uh let me just say as I've +said by + + align:start position:0% +said by + + + align:start position:0% +said by +email um thanks very much for your + + align:start position:0% +email um thanks very much for your + + + align:start position:0% +email um thanks very much for your +patience as this series of lectures was + + align:start position:0% +patience as this series of lectures was + + + align:start position:0% +patience as this series of lectures was +videotaped and um thanks for filling out + + align:start position:0% +videotaped and um thanks for filling out + + + align:start position:0% +videotaped and um thanks for filling out +these forms maybe just leave them on the + + align:start position:0% +these forms maybe just leave them on the + + + align:start position:0% +these forms maybe just leave them on the +table up there as you go out and above + + align:start position:0% +table up there as you go out and above + + + align:start position:0% +table up there as you go out and above +all thanks for taking the course thank + + align:start position:0% +all thanks for taking the course thank + + + align:start position:0% +all thanks for taking the course thank +you thanks \ No newline at end of file diff --git a/RhMdeFIw1rM.txt b/RhMdeFIw1rM.txt new file mode 100644 index 0000000000000000000000000000000000000000..68eca16e4549d0b42b4ab762c2c4061474e3b82c --- /dev/null +++ b/RhMdeFIw1rM.txt @@ -0,0 +1,1299 @@ +align:start position:0% + +so um + + align:start position:0% +so um + + + align:start position:0% +so um +the thing about an expected value value + + align:start position:0% +the thing about an expected value value + + + align:start position:0% +the thing about an expected value value +of information it's an expected value + + align:start position:0% +of information it's an expected value + + + align:start position:0% +of information it's an expected value +that is + + align:start position:0% +that is + + + align:start position:0% +that is +we're we're always dealing expectations + + align:start position:0% +we're we're always dealing expectations + + + align:start position:0% +we're we're always dealing expectations +here in the world of uncertainty so you + + align:start position:0% +here in the world of uncertainty so you + + + align:start position:0% +here in the world of uncertainty so you +may have the information that says it's + + align:start position:0% +may have the information that says it's + + + align:start position:0% +may have the information that says it's +really good and it turns out that it's + + align:start position:0% +really good and it turns out that it's + + + align:start position:0% +really good and it turns out that it's +not so good so you you're you're not + + align:start position:0% +not so good so you you're you're not + + + align:start position:0% +not so good so you you're you're not +something that it's + + align:start position:0% +something that it's + + + align:start position:0% +something that it's +uh absolutely sure but it's an expected + + align:start position:0% +uh absolutely sure but it's an expected + + + align:start position:0% +uh absolutely sure but it's an expected +value + + align:start position:0% +value + + + align:start position:0% +value +so now let me talk about + + align:start position:0% +so now let me talk about + + + align:start position:0% +so now let me talk about +uh the way when we do this in a full + + align:start position:0% +uh the way when we do this in a full + + + align:start position:0% +uh the way when we do this in a full +analysis + + align:start position:0% +analysis + + + align:start position:0% +analysis +and i think it's important as a baseline + + align:start position:0% +and i think it's important as a baseline + + + align:start position:0% +and i think it's important as a baseline +thank you for the uh word it's a + + align:start position:0% +thank you for the uh word it's a + + + align:start position:0% +thank you for the uh word it's a +baseline + + align:start position:0% +baseline + + + align:start position:0% +baseline +for how we think about it so + + align:start position:0% +for how we think about it so + + + align:start position:0% +for how we think about it so +the calculations are complex + + align:start position:0% +the calculations are complex + + + align:start position:0% +the calculations are complex +first of all any test you can have can + + align:start position:0% +first of all any test you can have can + + + align:start position:0% +first of all any test you can have can +many results had to have many different + + align:start position:0% +many results had to have many different + + + align:start position:0% +many results had to have many different +results for example a prototype plan + + align:start position:0% +results for example a prototype plan + + + align:start position:0% +results for example a prototype plan +might work very well well so so poorly + + align:start position:0% +might work very well well so so poorly + + + align:start position:0% +might work very well well so so poorly +failed + + align:start position:0% +failed + + + align:start position:0% +failed +so you don't get necessarily a yes no + + align:start position:0% +so you don't get necessarily a yes no + + + align:start position:0% +so you don't get necessarily a yes no +answer you get a range of answers + + align:start position:0% +answer you get a range of answers + + + align:start position:0% +answer you get a range of answers +now these answers don't prove what will + + align:start position:0% +now these answers don't prove what will + + + align:start position:0% +now these answers don't prove what will +happen + + align:start position:0% +happen + + + align:start position:0% +happen +why is that i've run it i've got a + + align:start position:0% +why is that i've run it i've got a + + + align:start position:0% +why is that i've run it i've got a +result it works well + + align:start position:0% +result it works well + + + align:start position:0% +result it works well +do i know that it's going to work well + + align:start position:0% +do i know that it's going to work well + + + align:start position:0% +do i know that it's going to work well +or don't i + + align:start position:0% + + + + align:start position:0% + +the test results will not prove what + + align:start position:0% +the test results will not prove what + + + align:start position:0% +the test results will not prove what +happens they are samples just like if i + + align:start position:0% +happens they are samples just like if i + + + align:start position:0% +happens they are samples just like if i +go through a + + align:start position:0% +go through a + + + align:start position:0% +go through a +test for tb or + + align:start position:0% +test for tb or + + + align:start position:0% +test for tb or +contemporaneously if i go through a test + + align:start position:0% +contemporaneously if i go through a test + + + align:start position:0% +contemporaneously if i go through a test +for covid and i have a negative result + + align:start position:0% +for covid and i have a negative result + + + align:start position:0% +for covid and i have a negative result +it doesn't necessarily mean + + align:start position:0% +it doesn't necessarily mean + + + align:start position:0% +it doesn't necessarily mean +that the + + align:start position:0% +that the + + + align:start position:0% +that the +uh that i am i'm negative it might be + + align:start position:0% +uh that i am i'm negative it might be + + + align:start position:0% +uh that i am i'm negative it might be +there's a false negative or contrarily + + align:start position:0% +there's a false negative or contrarily + + + align:start position:0% +there's a false negative or contrarily +that's a false positive they thought + + align:start position:0% +that's a false positive they thought + + + align:start position:0% +that's a false positive they thought +they saw something but it's not there + + align:start position:0% +they saw something but it's not there + + + align:start position:0% +they saw something but it's not there +so what the new information does is not + + align:start position:0% +so what the new information does is not + + + align:start position:0% +so what the new information does is not +tell you what was happening you knew + + align:start position:0% +tell you what was happening you knew + + + align:start position:0% +tell you what was happening you knew +this already but i'm emphasizing it + + align:start position:0% +this already but i'm emphasizing it + + + align:start position:0% +this already but i'm emphasizing it +but it says okay + + align:start position:0% +but it says okay + + + align:start position:0% +but it says okay +you thought it was like this you got + + align:start position:0% +you thought it was like this you got + + + align:start position:0% +you thought it was like this you got +some new information + + align:start position:0% +some new information + + + align:start position:0% +some new information +it made you think that it might be + + align:start position:0% +it made you think that it might be + + + align:start position:0% +it made you think that it might be +different so each + + align:start position:0% +different so each + + + align:start position:0% +different so each +piece of new information whether it + + align:start position:0% +piece of new information whether it + + + align:start position:0% +piece of new information whether it +performs well very well poorly so so and + + align:start position:0% +performs well very well poorly so so and + + + align:start position:0% +performs well very well poorly so so and +so on + + align:start position:0% +so on + + + align:start position:0% +so on +uh + + align:start position:0% +uh + + + align:start position:0% +uh +updates the prior estimates + + align:start position:0% +updates the prior estimates + + + align:start position:0% +updates the prior estimates +the technical way to do that is using + + align:start position:0% +the technical way to do that is using + + + align:start position:0% +the technical way to do that is using +something called bayes theorem + + align:start position:0% +something called bayes theorem + + + align:start position:0% +something called bayes theorem +now this is not a particularly uh simple + + align:start position:0% +now this is not a particularly uh simple + + + align:start position:0% +now this is not a particularly uh simple +topic we get to because if i have say + + align:start position:0% +topic we get to because if i have say + + + align:start position:0% +topic we get to because if i have say +five results as i listed before + + align:start position:0% +five results as i listed before + + + align:start position:0% +five results as i listed before +and each test result implies a different + + align:start position:0% +and each test result implies a different + + + align:start position:0% +and each test result implies a different +value of the project each with a + + align:start position:0% +value of the project each with a + + + align:start position:0% +value of the project each with a +different probability that five test + + align:start position:0% +different probability that five test + + + align:start position:0% +different probability that five test +results will give you five different + + align:start position:0% +results will give you five different + + + align:start position:0% +results will give you five different +updates + + align:start position:0% +updates + + + align:start position:0% +updates +for your system and + + align:start position:0% +for your system and + + + align:start position:0% +for your system and +each will have a different set of prior + + align:start position:0% +each will have a different set of prior + + + align:start position:0% +each will have a different set of prior +probabilities that you updated from the + + align:start position:0% +probabilities that you updated from the + + + align:start position:0% +probabilities that you updated from the +priors to the posteriors + + align:start position:0% +priors to the posteriors + + + align:start position:0% +priors to the posteriors +and you have five different solutions so + + align:start position:0% +and you have five different solutions so + + + align:start position:0% +and you have five different solutions so +each + + align:start position:0% +each + + + align:start position:0% +each +so the + + align:start position:0% +so the + + + align:start position:0% +so the +calculation of this + + align:start position:0% +calculation of this + + + align:start position:0% +calculation of this +uh process that is the expected value of + + align:start position:0% +uh process that is the expected value of + + + align:start position:0% +uh process that is the expected value of +sample information is complicated + + align:start position:0% +sample information is complicated + + + align:start position:0% +sample information is complicated +so first of all + + align:start position:0% +so first of all + + + align:start position:0% +so first of all +what's bayes theorem i imagine that many + + align:start position:0% +what's bayes theorem i imagine that many + + + align:start position:0% +what's bayes theorem i imagine that many +of you if not most of you who have + + align:start position:0% +of you if not most of you who have + + + align:start position:0% +of you if not most of you who have +already dealt with this maybe you had in + + align:start position:0% +already dealt with this maybe you had in + + + align:start position:0% +already dealt with this maybe you had in +a course and had to pass quizzes on it + + align:start position:0% +a course and had to pass quizzes on it + + + align:start position:0% +a course and had to pass quizzes on it +and so forth but this is a recall + + align:start position:0% +and so forth but this is a recall + + + align:start position:0% +and so forth but this is a recall +let me + + align:start position:0% +let me + + + align:start position:0% +let me +remind everybody or introduce the others + + align:start position:0% +remind everybody or introduce the others + + + align:start position:0% +remind everybody or introduce the others +to uh what it is + + align:start position:0% +to uh what it is + + + align:start position:0% +to uh what it is +the formula is very simple + + align:start position:0% +the formula is very simple + + + align:start position:0% +the formula is very simple +but i'm arguing for you this is what i'm + + align:start position:0% +but i'm arguing for you this is what i'm + + + align:start position:0% +but i'm arguing for you this is what i'm +talking about because it comes up + + align:start position:0% +talking about because it comes up + + + align:start position:0% +talking about because it comes up +is it's impractical use for a system + + align:start position:0% +is it's impractical use for a system + + + align:start position:0% +is it's impractical use for a system +designed on a regular basis + + align:start position:0% +designed on a regular basis + + + align:start position:0% +designed on a regular basis +but let me tell you what it is and we'll + + align:start position:0% +but let me tell you what it is and we'll + + + align:start position:0% +but let me tell you what it is and we'll +you'll see what i'm i hope you'll see + + align:start position:0% +you'll see what i'm i hope you'll see + + + align:start position:0% +you'll see what i'm i hope you'll see +what i'm coming to + + align:start position:0% +what i'm coming to + + + align:start position:0% +what i'm coming to +so the probability the posterior + + align:start position:0% +so the probability the posterior + + + align:start position:0% +so the probability the posterior +probability of something + + align:start position:0% +probability of something + + + align:start position:0% +probability of something +a + + align:start position:0% +a + + + align:start position:0% +a +say that the market will sell that the + + align:start position:0% +say that the market will sell that the + + + align:start position:0% +say that the market will sell that the +product will sell well + + align:start position:0% +product will sell well + + + align:start position:0% +product will sell well +after the observation b + + align:start position:0% +after the observation b + + + align:start position:0% +after the observation b +call basically called a probability of a + + align:start position:0% +call basically called a probability of a + + + align:start position:0% +call basically called a probability of a +given b that is + + align:start position:0% +given b that is + + + align:start position:0% +given b that is +i had a prior probability maybe 50 + + align:start position:0% +i had a prior probability maybe 50 + + + align:start position:0% +i had a prior probability maybe 50 +percent is going to sell well + + align:start position:0% +percent is going to sell well + + + align:start position:0% +percent is going to sell well +i took my tractor to the state fair + + align:start position:0% +i took my tractor to the state fair + + + align:start position:0% +i took my tractor to the state fair +they gushed over it and made me think ah + + align:start position:0% +they gushed over it and made me think ah + + + align:start position:0% +they gushed over it and made me think ah +it will probably it's more than 50 50 + + align:start position:0% +it will probably it's more than 50 50 + + + align:start position:0% +it will probably it's more than 50 50 +chance it'll maybe a 70 30 chance it'll + + align:start position:0% +chance it'll maybe a 70 30 chance it'll + + + align:start position:0% +chance it'll maybe a 70 30 chance it'll +sell well + + align:start position:0% +sell well + + + align:start position:0% +sell well +so my posterior probability my revised + + align:start position:0% +so my posterior probability my revised + + + align:start position:0% +so my posterior probability my revised +probability + + align:start position:0% +probability + + + align:start position:0% +probability +is a simple formula + + align:start position:0% +is a simple formula + + + align:start position:0% +is a simple formula +it is equal to the probability you had + + align:start position:0% +it is equal to the probability you had + + + align:start position:0% +it is equal to the probability you had +in the beginning + + align:start position:0% +in the beginning + + + align:start position:0% +in the beginning +times a factor + + align:start position:0% +times a factor + + + align:start position:0% +times a factor +now + + align:start position:0% +now + + + align:start position:0% +now +all the devil is under these details + + align:start position:0% +all the devil is under these details + + + align:start position:0% +all the devil is under these details +the factor is + + align:start position:0% +the factor is + + + align:start position:0% +the factor is +the probability that b is correlated + + align:start position:0% +the probability that b is correlated + + + align:start position:0% +the probability that b is correlated +with a that these kinds of responses + + align:start position:0% +with a that these kinds of responses + + + align:start position:0% +with a that these kinds of responses +actually lead to uh the market results + + align:start position:0% +actually lead to uh the market results + + + align:start position:0% +actually lead to uh the market results +divided by the probability of b the + + align:start position:0% +divided by the probability of b the + + + align:start position:0% +divided by the probability of b the +prior probability of b + + align:start position:0% +prior probability of b + + + align:start position:0% +prior probability of b +now + + align:start position:0% +now + + + align:start position:0% +now +the issue is + + align:start position:0% +the issue is + + + align:start position:0% +the issue is +that although the formula is really + + align:start position:0% +that although the formula is really + + + align:start position:0% +that although the formula is really +simple you know it's uh uh + + align:start position:0% +simple you know it's uh uh + + + align:start position:0% +simple you know it's uh uh +your probability times a factor and i + + align:start position:0% +your probability times a factor and i + + + align:start position:0% +your probability times a factor and i +can state the factor is + + align:start position:0% +can state the factor is + + + align:start position:0% +can state the factor is +that the these elements are + + align:start position:0% +that the these elements are + + + align:start position:0% +that the these elements are +unavailable in practice + + align:start position:0% +unavailable in practice + + + align:start position:0% +unavailable in practice +that is how if you're thinking about how + + align:start position:0% +that is how if you're thinking about how + + + align:start position:0% +that is how if you're thinking about how +well + + align:start position:0% +well + + + align:start position:0% +well +the + + align:start position:0% +the + + + align:start position:0% +the +folks at the state fair are responding + + align:start position:0% +folks at the state fair are responding + + + align:start position:0% +folks at the state fair are responding +to my new tractor + + align:start position:0% +to my new tractor + + + align:start position:0% +to my new tractor +um and how does that correlate with the + + align:start position:0% +um and how does that correlate with the + + + align:start position:0% +um and how does that correlate with the +actual sales well that's something you + + align:start position:0% +actual sales well that's something you + + + align:start position:0% +actual sales well that's something you +don't have data on + + align:start position:0% +don't have data on + + + align:start position:0% +don't have data on +and + + align:start position:0% +and + + + align:start position:0% +and +what's the probability of b well you + + align:start position:0% +what's the probability of b well you + + + align:start position:0% +what's the probability of b well you +could think that you you might imagine + + align:start position:0% +could think that you you might imagine + + + align:start position:0% +could think that you you might imagine +some ways of doing this but you don't + + align:start position:0% +some ways of doing this but you don't + + + align:start position:0% +some ways of doing this but you don't +know + + align:start position:0% +know + + + align:start position:0% +know +now if you're doing a repetitive test + + align:start position:0% +now if you're doing a repetitive test + + + align:start position:0% +now if you're doing a repetitive test +and have been doing this + + align:start position:0% +and have been doing this + + + align:start position:0% +and have been doing this +say agricultural sampling or test fields + + align:start position:0% +say agricultural sampling or test fields + + + align:start position:0% +say agricultural sampling or test fields +if you have lots of data and so forth + + align:start position:0% +if you have lots of data and so forth + + + align:start position:0% +if you have lots of data and so forth +you can get these conditional + + align:start position:0% +you can get these conditional + + + align:start position:0% +you can get these conditional +probabilities as they're called + + align:start position:0% +probabilities as they're called + + + align:start position:0% +probabilities as they're called +and + + align:start position:0% +and + + + align:start position:0% +and +you can run the analysis but in general + + align:start position:0% +you can run the analysis but in general + + + align:start position:0% +you can run the analysis but in general +you won't have them + + align:start position:0% +you won't have them + + + align:start position:0% +you won't have them +so that although the formula is really + + align:start position:0% +so that although the formula is really + + + align:start position:0% +so that although the formula is really +simple + + align:start position:0% +simple + + + align:start position:0% +simple +from the point of view of system design + + align:start position:0% +from the point of view of system design + + + align:start position:0% +from the point of view of system design +and management they're really not + + align:start position:0% +and management they're really not + + + align:start position:0% +and management they're really not +available but i want to + + align:start position:0% +available but i want to + + + align:start position:0% +available but i want to +show you how the thing works so that you + + align:start position:0% +show you how the thing works so that you + + + align:start position:0% +show you how the thing works so that you +can appreciate what's going on and why + + align:start position:0% +can appreciate what's going on and why + + + align:start position:0% +can appreciate what's going on and why +there's a another approach + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/Rn9zldxtZko.txt b/Rn9zldxtZko.txt new file mode 100644 index 0000000000000000000000000000000000000000..ee53c0bd4bd153154eb0bf3b72b0119bf0d9f27b --- /dev/null +++ b/Rn9zldxtZko.txt @@ -0,0 +1,82 @@ +PROFESSOR: Hi. + +In this clip, we're going to +discuss the numbering and + +labeling conventions of +RNA and of protein. + +Here we have a nucleoside +triphosphate or NTP. + +This NTP is numbered +on each carbon. + +And we're going to start here +to the right of this oxygen + +and label one prime and proceed +two prime, three + +prime, four prime, and this +last, five prime carbon. + +This means that when we +polymerize two or more of + +these NTP's to get an RNA chain, +it becomes apparent why + +one end is labeled five prime +and the other end is labeled + +three prime. + +On this end, the extending atom +is the five prime carbon. + +And on this side, the other end, +the extending atom is the + +three prime carbon attached +to this oxygen. + +This three prime carbon is where +you would attach another + +NTP if you would wish to +extend this chain. + +And so we label the ends of RNA +five prime to three prime. + +And RNA is always polymerized in +the five prime to the three + +prime direction. + +Now with our amino acid, we +label this end, which is our + +amino terminus, as N and this +end which is our carboxy + +terminus as C. As before, when +we polymerize three amino + +acids into this short protein +chain, I'm going to label this + +end which has a protruding amino +terminus as N and this + +end which has a protruding +carboxy terminus as C. + +So that's how the conventions +are in science to label and + +number amino acids +and proteins. + +Thanks for watching. \ No newline at end of file diff --git a/RsJ1eg7XNVs.txt b/RsJ1eg7XNVs.txt new file mode 100644 index 0000000000000000000000000000000000000000..52ef5f9f8b7dd1ba97e7019c5b0efdb39e766c3d --- /dev/null +++ b/RsJ1eg7XNVs.txt @@ -0,0 +1,1914 @@ +Let's get started. + +Can you hear me back there? +Loud and clear. + +OK. +Let's get started. + +Before I begin, +just a couple of announcements. + +Brad Buren is one of our +students here and he needs a + +note-taker. +It's a paid position. + +So if you are interested you +can stop by after class and see + +him. +He's sitting right here out + +there, OK? +Second, just a reminder that + +6.002 does have prerequisites. +And the prerequisites are 8.02 + +and 18.03. +So with that let me start off + +with the usual. +Do a quick review of what we've + +done so far. +So we started out life looking + +at the laws of physics and +Maxwell's equations and so on. + +And those were way too hard so +we said let's make life easy for + +ourselves. +So we chose to play in this + +playground in which we said we +shall adhere to the lumped + +matter discipline. +OK? + +The LMD. +So we are in that playground. + +So this entire course, +and for that matter large parts + +of EECS are within that +playground, within which the + +lumped matter discipline +applies. + +So as soon as we jumped into +the playground, + +the LMD playground, +we could take Maxwell's + +equations and abstract them out +into two very, + +very simple rules. +And the very simple rules were + +KVL and KCL. +KVL simply said that I can sum + +the voltages in any loop in a +circuit and the result then + +would be zero. +Similarly, I can sum the + +currents that enter or exit any +node and the sum will also be + +zero. +So what you can now do is, + +if you feel like, +you can go around and brag. + +Oh, yeah, we use Maxwell's +equations in everyday life and, + +yeah, it's good stuff. +And the key is that this is + +really an encapsulation of +Maxwell's equations within this + +playground that we are in. +So I talked about the first + +method of circuit analysis in +the last lecture. + +And that method simply took +the, wrote KVL for all the + +loops, wrote KCL for all the +nodes and wrote element vi + +relationships. +And together gave you a big + +bunch of equations. +And you sat down and grunged + +through the equations and you +solved for branch voltages and + +currents. +So we reviewed a second method + +of circuit analysis. +And I'll simply call it circuit + +composition. +The basic idea behind this + +method was to learn some simple +rules of how resistors add and + +conductances add and so on and +so forth and look at a circuit + +and simplify the circuit by +making series simplifications + +when the resistors are in series +and so on and so forth, + +and compose it and play around +with it till we end up with the + +current, the voltages that we +are looking for. + +This is the intuitive method. +And so a section in Chapter 2, + +I believe, of the course notes +discusses several examples using + +this method and attempts to make +a little bit formal the + +intuitive approach that is +applied in this method. + +So we then looked at the node +method. + +And the node method was simply +a particular way of applying KVL + +and KCL. +Node method, + +remember? +We took a ground node. + +Then we labeled the nodes of +the remaining voltages with + +respect to that ground. +Then we wrote KCL for each of + +the nodes. +And when we wrote KCL for each + +of the nodes, +remember, KVL was implicit in + +this expression that we used for +each of the currents that were + +exiting each node. +So if Ej was a node voltage, + +then Ej minus Ei multiplied by +the conductance Gi was the + +current that was going through +one of those, + +I should call it Gij. +This is a conductance that + +connects nodes i and j. +That gave us the KVL that fed + +into the same system. +So these are three methods. + +The node method, +by the way, is sort of the + +workhorse of the 6.002 industry. +And for that matter for all of + +the circuits industry. +When in doubt, + +apply the mode method, +you'll be OK. + +That applies to linear +circuits, nonlinear circuits, + +what have you. +What I'm going to do today is + +go through two more methods. +So notice that the first few + +lectures of this course, +the first three lectures simply + +comprise transitioning you from +the world of physics to the + +world of EECS. +And then two lectures on giving + +you a bag of tricks. +So we start you off with the + +sort of tools, +your mallets and chisels and so + +on and so forth. +And these five methods are your + +tools. +We'll look at two methods + +today. +One method is called the method + +of superposition and the second +method is called the Thevenin + +method. +And these methods apply only to + +linear circuits. +So we look at the subset of + +circuits that are linear, +and these two methods apply to + +only those circuits. +These are methods that combined + +with intuition really enables +you to solve very interesting + +circuits very, +very quickly. + +So let me do an example using a +usual node method. + +And then jump into introducing +the superposition methods and + +Thevenin methods using that same +example. + +So let me draw you an example +circuit here. + +So, again, I'm using this +example, I will use this example + +to introduce the method of +superposition and the Thevenin + +method. +So what I'm going to do is + +start off the usual way and +analyze the circuit using a + +method that you know now, +the node method. + +And what I'll do is write down +the node equations for this by + +applying the node method. +So if you recall the node + +method. +I choose a ground node. + +I'm going to choose this node. +It's got both the voltage + +source connected to it, +and it's also got many other + +edges impinging on it. +So I'm going to choose that as + +my ground node and I'm going to +label the other nodes with their + +voltages. +So this is an unknown. + +I'll label it as e. +I guess we just have one + +unknown e. +And I know the voltage of this + +node, and that is simply V. +Since it's V, + +there's a voltage source +between the ground node and that + +node. +So what I can do next is that I + +can write down the node equation +for this node and then go from + +there. +So let me go ahead and do that. + +So let me sum up the currents +going outside, + +going outwards. +So I have e minus v divide by + +R1, I have e minus zero divide +by R2, and I have minus i equals + +zero. +This is a node equation. + +The first thing I want you to +observe is that this equation is + +linear in V and i. +What I mean by linear is that + +you don't see terms like Vi or +V-squared and things like that. + +It's some constant times V plus +some constant times i equals + +some other constant. +So that's quite nice. + +So I'm going to rearrange the +terms in the following manner. + +I'll move the known sources to +the right-hand side and collect + +the coefficients of e on this +side, so I get one by R1 plus + +one by R2 over here. + +So stare at this for a moment +and notice again here I have e, + +my unknown node voltage, +there is some constant + +multiplier, and that equals some +function of V summed up with + +some function of i. +And, again, notice that this is + +a linear combination of V and i. +No multiplication terms and so + +on and so forth. +This is a pretty standard form + +in which we will represent +equations quite often. + +And just to label it, +this is often labeled G as the + +conductance matrix. +Of course this is e, + +our unknown node voltages, +and this is a linear sum of + +sources. +So this is a very standard way + +that we will represent +equations. + +We did that last week as well, +or rather on Tuesday where I + +took a conductance matrix, +multiplied that by a column + +vector of unknown node voltages +and equated that to some linear + +combination of my source +voltages. + +The reason the circuit is +linear is that I have only + +linear elements in the circuit. +I don't have any nonlinear + +elements. +And because of that I can + +rewrite this in the following +manner. + +I'm just going to express e as +a function of V and i and bring + +it over to this side. +So it's some function of i. + +So I get R1 R2 divide by R1 +plus R2. + +And I bring R1 R2 to this side. +That's what I get. + +So stare at this for a few +seconds, very common form. + +My unknown node voltage is +equal to this stuff on the + +right-hand side. +The stuff on the right-hand + +side has a term multiplying the +source voltage V and some other + +term multiplying the current I. +And if I were to put this in + +sort of symbol-like form my +unknown node voltage is some + +constant times V1 plus some +constant times, + +is of the form constant times +the source current, + +constant times the source +voltage and so on. + +The units of As and Vs are +different because in this case A + +has no units because V is a +voltage. + +And so is e. +In this case V has units of + +resistance. +So that V times i gives me a + +voltage. +So stare at this equation for a + +few seconds and this should help +us build up some insight that + +will allow us to write down the +answer almost by inspection. + +I'm going to show you a method +now, in a few minutes, + +which will allow you to write +down the answer e just by + +starring at the circuit without +having to go through node + +equations and so on. +The more and more methods I + +teach you, the more you will be +able to do a lot of this + +completely by yourselves. +In this particular example it's + +a relatively simple circuit but +these methods would be + +particularly useful when you +have more complicated + +situations. +But before I go on let me spend + +a few minutes pontificating on +linearity. + +So that's a linear circuit. +And this equation gives me the + +unknown node voltage e as a +linear sum of source voltages + +and source currents. +Linearity implies two + +properties, the property of +homogeneity and also gives vice + +to the property of +superposition. + +Let's do homogeneity first. +What this says is if I have a + +circuit, some circuit and I feed +it some sort of inputs, + +A, then let's say my output is +S. + +If you're feeling hungry think +of these as apples and the + +circuit converts them into +applesauce. + +So what homogeneity says is +that what I can do is if I take + +each of my apples and instead of +feeding it an entire apple what + +if I give it three-quarters of +an apple? + +Say I multiple all my inputs by +some constant alpha, + +three-quarters. +What that says is that at the + +output instead of getting one +full bottle of applesauce I'm + +going to get three-quarters of a +bottle of apple sauce. + +So if I proportionately reduce +all the inputs and if this is a + +linear circuit then so shall my +output be reduced in the same + +proportion. +So that's homogeneity. + +Next, let's look at +superposition. + +The property of superposition +says the following. + +The same kind of circuit. +If I feed it apples then I get + +applesauce. +I take the same circuit, + +and this time around if I feed +the circuit a different set of + +inputs, say blueberries. +And let's say my output, + +oops, let me do it this way. +So as my output I get blueberry + +sauce, if such exists. +So apples applesauce, + +blueberries give me blueberry +sauce. + +Then what I'm going to get if I +mix up the two, + +so let's say I take my circuit, +the same circuit with a set of + +inputs and in this example one +output. + +Let's say I mix up my inputs +and some of my inputs in the + +following way, +here I feed an A1 plus B1 and + +here A2 plus B2 and so on then +at the output I am going to get + +a mush of apple sauce and +blueberry sauce. + +All this says is that if I +apply just apples I get + +applesauce. +If I apply just blueberries I + +get blueberry sauce. +Then if I were to figure out + +how this blender would have +worked had I fed in the + +combinations of apples and +blueberries, then for the + +purposes of understanding that +blender all I could have done + +was taken by two outputs and +just mixed them up together + +myself and that's exactly what +I'd get. + +So if I sum up the inputs my +outputs would also be the sum of + +the outputs with the inputs +applied by themselves. + +So let me take this here and +munge around with hit for a few + +seconds and get something +interesting out of it. + +So notice two inputs, +two inputs, outputs. + +In your notes I've given you +another template for the next + +set of scribbles I'm going to +make here. + +So use the next set of +templates on page three. + +What I'm going to do here is +something very simple, + +set one output to zero and feed +a voltage V1. + +So that's feed a voltage V1 and +set the other output to zero. + +And let's say I get Y1 as an +output. + +And in this case I set the +first voltage to zero and feed a + +different voltage V2 on the +second input. + +And let's say my output is Y2. +This is just a particular + +application of the superposition +principle I just outlined. + +Apply V1 set one output to +zero. + +Apply V2 set the original +output to zero. + +Then what I'm going to find is +that the answer will simply look + +like this, just replace for As +and Bs what I just did and we + +get V1 and zero here and we get +zero and V2 here. + +And as my output I'm going to +get exactly the sum Y1 plus Y2. + +This is simply a particular +application of superposition + +where what I'm saying is the +following. + +If you look at this circuit +here effectively what have I + +done? +Effectively what I've done is + +apply the voltage V1 on one +input and a voltage V2 on the + +other input. +V1 here. + +V2 here. +And the output is Y1 plus Y2. + +What I'm saying is look +backwards now. + +What I'm saying is that the +whole components of the output + +Y1 plus Y2 could individually be +derived in the following manner. + +I could get the component Y1 by +simply applying one of the + +voltages and setting the other +to zero. + +I can get the other component +Y2 by setting yet another input + +to zero and applying the voltage +V2 to get Y2. + +And sum then up and that's my +answer. + +This will become a lot clearer +with an example. + +Again, remember if I have a +bunch of inputs applied to a + +circuit, V1, V2 and so on, +and I get some output then what + +this is saying is that I can +alternatively find out the + +answer by applying just one +voltage, setting all the others + +to zero, measuring the output, +apply a second voltage, + +set all inputs to zero, +measure the output and sum of + +applesauce and blueberry sauce +and there you get the answer. + +Let's do an example. +And before we go into that I + +talked about setting voltage +sources and current sources to + +zero. +First of all, + +what does it mean to set a +voltage source to zero? + +This is the same as this. +Setting a voltage source to + +zero is simply replacing the +voltage source with a short, + +and setting a current source to +zero simply implies an open + +circuit. +So when I say zero that source, + +if it's a voltage source short +it, if it's a current source + +open it. + +I can take any two nodes in the +world and measure the potential + +difference across them. +So there may be some potential + +difference across these set by +the circuit that I haven't shown + +you on this side. +There might be some other + +circuit that is controlling the +voltage of these two nodes. + +The same with the short. +What's V going to be? + +But there is a V. +It's zero. + +So that's method four, +method of superposition. + +And this method says that the +output of a circuit -- + +Again, remember I'm focusing on +linear circuits. + +Remember, I have this +playground where LMD applies. + +And within that playground I'm +playing in the south goal area. + +In the south goal area, +in that subset of the + +playground circuits are linear. +So in that part of the + +playground superposition applies +because there circuits are + +linear. +So the output of a circuit is + +determined by summing up the +responses to each source acting + +alone. + +Now, in this statement here +this source stands for + +independent source. +I haven't talked about + +independent versus dependent +sources. + +We'll talk about dependent +sources a few weeks from today. + +And just so you don't get +confused, for dependent sources + +you will be looking at Section +3.3.3 of your course notes to + +see how superposition works with +dependent sources. + +But remember we haven't covered +dependent sources yet. + +We will be covering them about +two weeks from now. + +So let's go back to our example +and apply the method of + +superposition to an example. +So the method says sum up the + +outputs of each of the +sub-circuits where I'm applying + +one source acting alone. +So let me just do this here. + +Let me start with the circuit. +And let me start with shutting + +I off. +So I have voltage V -- + +I have R2. +And I'm shutting I off. + +So I have replaced this with an +open circuit. + +So I is zero. +Let me call the node voltage eV + +to reflect that component of the +node voltage that arises due to + +V acting alone. +And you should look at this + +pattern here and very quickly be +able to write the answer for + +patterns like this voltage, +the two resistors. + +That's called a resistive +divider. + +It will appear again and again +and again. + +And eV is simply V times R2 +divided by R1 plus R2. + +That's still my ground node. +So the voltage here is simply + +this voltage divided by the two +resistors to give you the + +current multiplied by R2 to give +you the voltage across this R. + +Remember this pattern. +You apply voltage divider + +patterns probably more times +than any other pattern that you + +might imagine. +So that's with the V acting + +alone. +Now, let me do I acting alone. + +So for I acting alone -- + +And what I do this time around +is replace this with a short, + +replace the voltage source to +the short. + +And let me call this voltage eI +for the component of the voltage + +due to the current I. +And eI, in this case, + +is simply given by yet another +pattern here, + +the current across a pair or +resistors is simply the + +effective resistance multiplied +by the current so it's i and the + +effective resistance is R1, +R2 or R1 plus R2. + +That's eI. +That's a component that node + +due to the current I. +Now, so the method says that. + +Then take these components, +sum them up and there you have + +the answer. +So E is simply ev plus ei. + +The components of V and I +acting alone, + +just simply V times R2 divided +by R1 plus R2 plus R1, + +R2. +There we go. + +Fortunately, +the fates have been kind to us + +and the answer is the same as +the answer we obtained with the + +node method. +No surprise here. + +So this is actually an +incredibly simple method. + +So you can take a very complex +circuit. + +What have you really done here? +You can take a very complex + +circuit and you can solve a very +complex circuit by breaking it + +down into many simple individual +sub problems. + +You will do this in EECS time +and time and time again. + +Whether it's in software +systems or hardware systems or + +what have you, +you're often times building + +complicated systems. +Remember doom on this side? + +And the way and when you put +these things together, + +let's say a large software +system, is you don't write the + +whole piece of software starting +main and grunge down. + +You build a lot of little +components and tie the + +components together. +In the same manner here you + +take a big circuit and you find +its behavior for each source + +acting alone. +Lots of little inky dinky + +simple little circuits. +And you will see examples in + +your homework where you're given +a big circuit or because it set + +all the Is to zero and the other +Vs to zero the whole circuit + +almost vanishes and all that +you're left with is a little + +resistor or two. +So this is the very, + +very powerful method. +I'd like to do a little + +demonstration for you. +And what I'm going to show you + +is the demo is a vat of water. +Actually, I'll tell you what it + +is in a second. +But assume it is salt water for + +now. +I'll apply two voltages. + +In this case I'm going to apply +a sinusoid. + +That's not very good. +A sinusoid and a triangular + +wave. +And what I'm going to do is + +measure the response at this +site. + +Now, this is a vat of salt +water. + +And I'm going to tell you it +behaves like a linear system. + +If you view each little +particle, or each little + +cubic-centimeter or whatever of +water, it'll behave like little + +resistor. +So this vat of salt water + +behaves like big distributed +resistor in the following + +manner. + +And so on. +This of this big mesh of little + +resistors, but it's all +resistors. + +It's a linear circuit. +So I'm going to apply two + +voltages, a triangular and a +sinusoid, and we're going to + +observe the output. +And what do you expect to see + +there? +You will see the superposition + +of the two, which is you'll see +a sinusoid. + +And then you'll see the jagged +triangular thing articulating + +the sinusoid pattern. +What I'm going to do right now, + +don't put any water yet. +This is the vat of nothing + +right now. +It's all empty. + +Can we show the screen on this +side? + +The oscilloscope screen? + +OK. +Oh, there you go. + +So this is the screen of the +oscilloscope now. + +Notice that I have a sinusoid +and I have a triangular wave and + +the output is zero. +And the reason is there is + +nothing in this vat. +It's empty. + +So previously when I taught +this course I would get + +saltwater and pour saltwater. +Then we discovered a much + +better source of water that +conducted electricity like one + +real mean fluid. +Cambridge water. + +It just works very pleasantly. +It just conducts electricity + +like nothing at all. +And I've been thinking of using + +Charles River water next time +and see what happens, + +although there we'd probably +get some biological organisms + +doing strange things at you. +But go ahead. + +Our friendly demonstration +expert, Lorenzo, + +will pour some water into the +vat. + +And you should begin seeing the +output being a superposition of + +the two. +So as he pours, + +there you go, +do you see that? + +So you do see the sinusoidal +articulation and the jagged wave + +form. +And just to have some more fun, + +what I can do is increase one +of the voltages. + +And you'll see -- + +Now you know what would have +happened if I had used Charles + +River water. +So my output keeps increasing + +as I increase the corresponding +wave form. + +I could do this, +this is fun. + +So let me pause there and go +onto the next topic. + +So that little demonstration +showed you that even something + +as simple as this physical +entity vat of water behaves like + +a linear system, +and we can model that linear + +system as a set of resistors. +Unbeknownst to you, + +right now, in the past ten +seconds I introduced a new + +concept. +It's called subliminal + +advertising. +So one of the things we do in + +EE a lot is model real systems. +So often times if I wanted to + +look at the behavior of salt, +behavior of a vat of water, + +I can model it as a set of +resistors for certain kinds of + +activities. +Just hold that thought for some + +time later in your careers. +All right. + +That's method four, +the superposition method. + +Remember, it is methods like +this that will make your life + +really, really, +really easy. + +If you find that you are having +to do a lot of grunging homework + +or something, +just step back and think + +superposition, +think Thevenin or think + +composition rule. +There must be a simpler way + +usually. +Let's do the next method. + +This is called the Thevenin +method. + +To derive this method let me +start by applying superposition + +to some circuit. +So let's say I have some + +arbitrary network N. +Assume it's a linear network + +and the network has a whole +bunch of goodies in it. + +It has a bunch of resistors, +it has a bunch of voltage + +sources, and it has a bunch of +current sources. + +Many current sources. +Many voltage sources. + +Many resistors. +Some jumbled voltage sources, + +current sources and resistors. +And I look at two nodes in this + +network. +Here are two nodes in the + +network, two points in the +network were elements connect. + +I'm looking at those two nodes +and all I want to do is the + +following. +I want to figure out if I take + +a rinky-dinky little current +source and apply it there, + +all I want to figure out is +what is V and what is I. + +There is this mongo box out +here, a black box of resistors, + +voltage source and current +sources, too many to count. + +I pick two nodes, +apply a current source, + +and all I care about is what is +the voltage that I will measure + +by applying it here. +Notice the current here will be + +I because the current here is I. +And I apply it here. + +I want to measure what the +voltage is. + +Now, with the insight you've +obtained from superposition, + +you should be able to jump up +and state the form of the + +answer. +So by superposition we know the + +following. +We know that the effect of the + +circuit will be the same as the +sum of components being added + +up. +Sum of component, + +sum of component, +a bunch of components added up. + +Each component will be the +response of one source acting + +alone. +So if I can figure out the + +effect of one source acting +alone and put that down here, + +and do the same thing for all +the sources, that's what I will + +get. +So for the source Vm it's a + +linear circuit. +So I know that my answer is + +going to be, in the final answer +is going to be a Vm term and + +it's going to be multiplied by +some alpha M term. + +I know that. +It's a linear circuit so I know + +that the answer shall have a +term Vm multiplied by some + +constant. +Simple, I know that. + +Similarly, the same is true +for, oh, this is the term Vm. + +And what I can do is I can +measure just this effect by + +setting all the other sources to +zero. + +So I can set all the other +current sources to zero and all + +voltage sources, +except for this one, + +and I can get that answer. +So, similarly, + +for every voltage source I am +going to get a term. + +So for every single voltage +source, M1, M2, + +M3 and so on I'm going to get +such a term and they're all + +going to sum up. +Similarly, I'm going to get a + +term for In. +And I know there will be an In + +term, and I know it's going to +be some constant beta + +multiplying In. +In this example of ours here, + +in this example, +remember alpha was this and + +beta was this constant here. +There's some constant beta, + +some constant alpha. +And because I have a whole + +bunch of current sources there's +going to be such a term for each + +one of them. +And each one of these terms, + +Vm, In will be the voltage I +would see here if I set all the + +other Vms to zero and I set all +the other current sources, + +except for that one to zero. +What am I missing? + +Is that it? +The response here, + +V here. +Am I missing anything here? + +Is that it? +Now, don't all yell at once. + +What am I missing? +Current source i, + +exactly. +So if I have a current source i + +then there's an effect of this +current as well. + +And so I write down i there, +too. + +It's going to be some constant +multiplying I. + +And that constant is going to +look like a resistor, + +right, because this circuit +contains current sources, + +voltage sources and resistors. +If I've shorted all my voltage + +sources and opened all my +current sources, + +what's left in here? +Just a whole caboodle full of + +Rs. +It's just going to look like + +some resistance R. +And that's what I get here. + +So this is what V is going to +look like and that's a form. + +So let's take a look at these +components. + +Let's focus on the easy part +first. + +What does this look like? +This component looks like an I, + +it looks like a current and has +some resistance. + +What is that resistance given +by? + +Supposing I gave you this +network and this currency source + +and I asked you tell me R. +How would you measure R? + +What you would do is open all +the current sources, + +short all the voltage sources, +put a ohmmeter in there and + +measure the resistance R. +That's R. + +OK, so we understand this term. +What about this term here? + +Can someone tell me the units +of this term here, + +this big thing here? +Voltage. + +This is a voltage. +This is a voltage. + +iR is a voltage. +So this does behave like a + +voltage. +And it behaves like some + +voltage V. +So notice that as far as this + +current I is concerned the rest +of the universe looks like a + +resistor and a voltage source +behaving in some manner. + +And let me just call it Vth for +now, and you'll know why in a + +second. + +The voltage has a form, +some voltage plus Ri. + +So, in other words, +as far as this I is concerned + +this whole network here N full +of all the nice stuff is + +indistinguishable to this I +here. + +So my I is sitting out there +injecting a current into two + +nodes. +If I am i, I'm looking at this, + +this network looks no different +than a voltage source in series + +with the resistor R. +Notice that the equation for + +this simple circuit is this, +so I is given by V minus Vth + +divided by R. +Just remember. + +It's a circuit. +In other words, + +Agarwal sitting here cannot +tell the difference if I'm + +measuring the voltage here +between a circuit that looks + +like a Vth in series to the +resistor or this huge mess of + +voltage sources and current +sources and so on. + +Now, we will talk about Vth and +R. + +R is called the resistance of +the network as seen from the + +port with all the sources shut +off. + +And similarly Vth, +what is Vth? + +Vth is the open circuit +voltage. + +In other words, +if I apply the voltage here + +this is the response of all the +current sources and all the + +voltage sources acting together. +So it's as if I took this out + +and simply measured my V here as +if I didn't exist, + +correct? +Because this is the component + +of i. +So if I opened i and measured + +V, I would get that big term on +the left-hand side. + +That's my Vth. +So that inspires the next + +method called the Thevenin +method. + +In this method what I'm going +to do is take some circuit, + +I'm on Page 9, +with a mess of stuff. + +It's a big mess of stuff. +And if I care to look at its + +impact on something else that I +add from the outside then as far + +as the outside world is +concerned this is + +indistinguishable from a circuit +that looks like this. + +So what I can do is if I want +to figure out what's happening + +here then, for the purpose of my +analysis, this simple network + +here with R and Vth becomes a +surrogate for this entire mess. + +So for the purpose of finding +out the behavior at this point, + +I can take this huge mess and +replace it with its Thevenin + +surrogate or Thevenin +equivalent. + +This is called the Thevenin +equivalent of this big network. + +Let me do an example that will +make the method completely + +clear. +Again, remember in EECS, + +most of our lives are about how +can we make things so simple as + +being able to be analyzed by +inspection? + +And so this is a method that +takes you further down that + +path. +So let me use the same circuit + +that I've been using before, +my voltage V, + +R1, R2. +This is an R. + +I'm 55 minutes fast so we have +another three or four minutes. + +So this is my circuit. +And let's say all I care about + +is finding out i1. +That's all I care about. + +And what I'm going to do is I'm +going to box this up and see if + +I can replace that with its +Thevenin equivalent. + +So I'm going to box that up. + +What I'm saying is that I'm +going to box it up and replace + +it with this Thevenin +equivalent. + +I don't know what Vth and R are +at this point. + +I'm just calling it Rth for +fun. + +I don't know what these two +values are, but if I knew what + +these two values were I can +determine I really trivially as + +follows. +I can get i1 as simply V minus + +Vth divided by R1 plus Rth. +So if I knew Vth and Rth, + +I can write down i1 by +inspection in that manner. + +So next, finally, +how do I get Vth and Rth? + +You get Rth by looking at this +network and shutting off all the + +voltage sources and measuring +the resistance there. + +So I short my voltage source, +that's R1. + +Oops, wrong way. +I need to look this way. + +So looking this way, +that's what I get. + +So what's Rth? +Rth is simply R2. + +So I have opened my current +source. + +Similarly, for Vth, +remember all I want to do is + +look at the two nodes, +step back, put a voltmeter + +there, measure the voltage, +that's my open circuit voltage. + +So the way I do it is I take +the circuit and simply measure + +the voltage there. +That's R2. + +That's my current capital I. +And I simply want to measure + +the open circuit voltage here, +which is what? + +Just simply if I stand back and +I kind of gingerly measure the + +voltage here without disturbing +anything, I simply get IR2. + +So Vth is IR2 and Rth is R2 and +here is the formula for the + +current in this branch when I +apply a voltage source and a + +resistor R1 to this little +circuit here. + +OK, let's pause and let me +summarize this in about ten + +seconds. +I had this circuit here. + +I wanted to find out i1. +So what I said I'd do is take + +this complicated mess, +well, it's not a complicated + +mess but assume it is, +and replace with it a + +resistance Rth got by turning +off all the sources. + +And the voltage in series, +Vth, which I get simply by + +pulling this thing out, +taking my input, + +this part out and simply +measuring the open circuit + +voltage out there, +Vth. + +And then I replaced the whole +network with this new network + +that they call the Thevenin +network, and voila, + +I get the answer in a second. \ No newline at end of file diff --git a/SFXxjejtsCI.txt b/SFXxjejtsCI.txt new file mode 100644 index 0000000000000000000000000000000000000000..5001d7a0043a0697bb443dc61de7ca43628c141d --- /dev/null +++ b/SFXxjejtsCI.txt @@ -0,0 +1,12587 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided 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position:0% +hundreds of MIT courses visit MIT + + + align:start position:0% +hundreds of MIT courses visit MIT +opencourseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu we're really lucky to have a + + align:start position:0% +ocw.mit.edu we're really lucky to have a + + + align:start position:0% +ocw.mit.edu we're really lucky to have a +guest lecturer uh David TZ today who is + + align:start position:0% +guest lecturer uh David TZ today who is + + + align:start position:0% +guest lecturer uh David TZ today who is +uh + + align:start position:0% +uh + + + align:start position:0% +uh +a very talented and experienced + + align:start position:0% +a very talented and experienced + + + align:start position:0% +a very talented and experienced +videographer and cinematographer with a + + align:start position:0% +videographer and cinematographer with a + + + align:start position:0% +videographer and cinematographer with a +vast array of experience everything from + + align:start position:0% +vast array of experience everything from + + + align:start position:0% +vast array of experience everything from +sort of pioneering Web video through + + align:start position:0% +sort of pioneering Web video through + + + align:start position:0% +sort of pioneering Web video through +feature films uh and in between also + + align:start position:0% +feature films uh and in between also + + + align:start position:0% +feature films uh and in between also +he's a a sort of well-known Tech Guru + + align:start position:0% +he's a a sort of well-known Tech Guru + + + align:start position:0% +he's a a sort of well-known Tech Guru +who has a a well-regarded Blog kino.com + + align:start position:0% +who has a a well-regarded Blog kino.com + + + align:start position:0% +who has a a well-regarded Blog kino.com +uh he's a graduate of uh mit's media lab + + align:start position:0% +uh he's a graduate of uh mit's media lab + + + align:start position:0% +uh he's a graduate of uh mit's media lab +and currently an instructor at Mass art + + align:start position:0% +and currently an instructor at Mass art + + + align:start position:0% +and currently an instructor at Mass art +and he's going to take us through some + + align:start position:0% +and he's going to take us through some + + + align:start position:0% +and he's going to take us through some +of the basics of lighting uh and we're + + align:start position:0% +of the basics of lighting uh and we're + + + align:start position:0% +of the basics of lighting uh and we're +then going to do a demonstration of + + align:start position:0% +then going to do a demonstration of + + + align:start position:0% +then going to do a demonstration of +basic interview three-point lighting + + align:start position:0% +basic interview three-point lighting + + + align:start position:0% +basic interview three-point lighting +which should be a lot of fun so take it + + align:start position:0% +which should be a lot of fun so take it + + + align:start position:0% +which should be a lot of fun so take it +away David well glad to be here thanks + + align:start position:0% +away David well glad to be here thanks + + + align:start position:0% +away David well glad to be here thanks +Chris so as Chris said we're going to + + align:start position:0% +Chris so as Chris said we're going to + + + align:start position:0% +Chris so as Chris said we're going to +talk about basic lighting and we're + + align:start position:0% +talk about basic lighting and we're + + + align:start position:0% +talk about basic lighting and we're +going to use um a simple straightforward + + align:start position:0% +going to use um a simple straightforward + + + align:start position:0% +going to use um a simple straightforward +interview uh as the subject uh of our + + align:start position:0% +interview uh as the subject uh of our + + + align:start position:0% +interview uh as the subject uh of our +lighting discussion um today of course + + align:start position:0% +lighting discussion um today of course + + + align:start position:0% +lighting discussion um today of course +there's a lot of things that we can + + align:start position:0% +there's a lot of things that we can + + + align:start position:0% +there's a lot of things that we can +light uh but basically interview + + align:start position:0% +light uh but basically interview + + + align:start position:0% +light uh but basically interview +lighting um will be will be our + + align:start position:0% +lighting um will be will be our + + + align:start position:0% +lighting um will be will be our +Focus um just just since we're at MIT we + + align:start position:0% +Focus um just just since we're at MIT we + + + align:start position:0% +Focus um just just since we're at MIT we +need to talk a little bit about what + + align:start position:0% +need to talk a little bit about what + + + align:start position:0% +need to talk a little bit about what +light is um it's a tiny sliver of the + + align:start position:0% +light is um it's a tiny sliver of the + + + align:start position:0% +light is um it's a tiny sliver of the +electromagnetic spectrum that our eyes + + align:start position:0% +electromagnetic spectrum that our eyes + + + align:start position:0% +electromagnetic spectrum that our eyes +are sensitive to um as the wavelengths + + align:start position:0% +are sensitive to um as the wavelengths + + + align:start position:0% +are sensitive to um as the wavelengths +get shorter you end up with things like + + align:start position:0% +get shorter you end up with things like + + + align:start position:0% +get shorter you end up with things like +X-rays and gamma rays and um and as the + + align:start position:0% +X-rays and gamma rays and um and as the + + + align:start position:0% +X-rays and gamma rays and um and as the +wavelengths get longer we end up with + + align:start position:0% +wavelengths get longer we end up with + + + align:start position:0% +wavelengths get longer we end up with +radio waves uh just like this wireless + + align:start position:0% +radio waves uh just like this wireless + + + align:start position:0% +radio waves uh just like this wireless +mic um going on here uh but this tiny + + align:start position:0% +mic um going on here uh but this tiny + + + align:start position:0% +mic um going on here uh but this tiny +tiny tiny sliver of the electromagnetic + + align:start position:0% +tiny tiny sliver of the electromagnetic + + + align:start position:0% +tiny tiny sliver of the electromagnetic +spectrum is what our eyes um happen to + + align:start position:0% +spectrum is what our eyes um happen to + + + align:start position:0% +spectrum is what our eyes um happen to +be sensitive to and this is the medium + + align:start position:0% +be sensitive to and this is the medium + + + align:start position:0% +be sensitive to and this is the medium +that we are working with these are our + + align:start position:0% +that we are working with these are our + + + align:start position:0% +that we are working with these are our +materials uh that we work with uh in + + align:start position:0% +materials uh that we work with uh in + + + align:start position:0% +materials uh that we work with uh in +film and video um and of course you know + + align:start position:0% +film and video um and of course you know + + + align:start position:0% +film and video um and of course you know +there's that classic experiment that um + + align:start position:0% +there's that classic experiment that um + + + align:start position:0% +there's that classic experiment that um +Newton did in his I guess it was his + + align:start position:0% +Newton did in his I guess it was his + + + align:start position:0% +Newton did in his I guess it was his +grandmother's barn or something um not + + align:start position:0% +grandmother's barn or something um not + + + align:start position:0% +grandmother's barn or something um not +only did he it was well known at his + + align:start position:0% +only did he it was well known at his + + + align:start position:0% +only did he it was well known at his +time you know that light you could um + + align:start position:0% +time you know that light you could um + + + align:start position:0% +time you know that light you could um +break white light into the constituency + + align:start position:0% +break white light into the constituency + + + align:start position:0% +break white light into the constituency +of the various colors uh of the rainbow + + align:start position:0% +of the various colors uh of the rainbow + + + align:start position:0% +of the various colors uh of the rainbow +uh but he also showed that once you + + align:start position:0% +uh but he also showed that once you + + + align:start position:0% +uh but he also showed that once you +broke it down to those colors you + + align:start position:0% +broke it down to those colors you + + + align:start position:0% +broke it down to those colors you +couldn't break it down any further and + + align:start position:0% +couldn't break it down any further and + + + align:start position:0% +couldn't break it down any further and +that with a second prism you could + + align:start position:0% +that with a second prism you could + + + align:start position:0% +that with a second prism you could +recombine that light back into white + + align:start position:0% +recombine that light back into white + + + align:start position:0% +recombine that light back into white +light so it turns out that working with + + align:start position:0% +light so it turns out that working with + + + align:start position:0% +light so it turns out that working with +any combination of red green and blue + + align:start position:0% +any combination of red green and blue + + + align:start position:0% +any combination of red green and blue +light we can create any of the colors + + align:start position:0% +light we can create any of the colors + + + align:start position:0% +light we can create any of the colors +that we're sensitive to and so + + align:start position:0% +that we're sensitive to and so + + + align:start position:0% +that we're sensitive to and so +interestingly enough uh most of our + + align:start position:0% +interestingly enough uh most of our + + + align:start position:0% +interestingly enough uh most of our +Imaging systems today uh basically work + + align:start position:0% +Imaging systems today uh basically work + + + align:start position:0% +Imaging systems today uh basically work +with red green and blue uh receptors + + align:start position:0% +with red green and blue uh receptors + + + align:start position:0% +with red green and blue uh receptors +which we uh will talk about why red + + align:start position:0% +which we uh will talk about why red + + + align:start position:0% +which we uh will talk about why red +green and blue happens to be sort of the + + align:start position:0% +green and blue happens to be sort of the + + + align:start position:0% +green and blue happens to be sort of the +star colors from which all other colors + + align:start position:0% +star colors from which all other colors + + + align:start position:0% +star colors from which all other colors +uh can be derived and it turns out that + + align:start position:0% +uh can be derived and it turns out that + + + align:start position:0% +uh can be derived and it turns out that +our eyes have receptors sensitive in the + + align:start position:0% +our eyes have receptors sensitive in the + + + align:start position:0% +our eyes have receptors sensitive in the +blue range the green range and the uh + + align:start position:0% +blue range the green range and the uh + + + align:start position:0% +blue range the green range and the uh +red range and we are most sensitive to + + align:start position:0% +red range and we are most sensitive to + + + align:start position:0% +red range and we are most sensitive to +those in the green range perhaps our + + align:start position:0% +those in the green range perhaps our + + + align:start position:0% +those in the green range perhaps our +ancestors um who could see green were + + align:start position:0% +ancestors um who could see green were + + + align:start position:0% +ancestors um who could see green were +more successful uh than our ancestors + + align:start position:0% +more successful uh than our ancestors + + + align:start position:0% +more successful uh than our ancestors +who were primarily sensitive to other + + align:start position:0% +who were primarily sensitive to other + + + align:start position:0% +who were primarily sensitive to other +uh uh frequencies of light who knows + + align:start position:0% +uh uh frequencies of light who knows + + + align:start position:0% +uh uh frequencies of light who knows +about that but enough technical stuff uh + + align:start position:0% +about that but enough technical stuff uh + + + align:start position:0% +about that but enough technical stuff uh +when we talk about light creatively + + align:start position:0% +when we talk about light creatively + + + align:start position:0% +when we talk about light creatively +we're not thinking about wavelengths and + + align:start position:0% +we're not thinking about wavelengths and + + + align:start position:0% +we're not thinking about wavelengths and +and and uh the individual colors that + + align:start position:0% +and and uh the individual colors that + + + align:start position:0% +and and uh the individual colors that +much but we're thinking about certain + + align:start position:0% +much but we're thinking about certain + + + align:start position:0% +much but we're thinking about certain +characteristics um we often talk about + + align:start position:0% +characteristics um we often talk about + + + align:start position:0% +characteristics um we often talk about +intensity how bright is the light and it + + align:start position:0% +intensity how bright is the light and it + + + align:start position:0% +intensity how bright is the light and it +turns out that since most um light + + align:start position:0% +turns out that since most um light + + + align:start position:0% +turns out that since most um light +sources radiate in all directions + + align:start position:0% +sources radiate in all directions + + + align:start position:0% +sources radiate in all directions +there's very very rapid falloff of light + + align:start position:0% +there's very very rapid falloff of light + + + align:start position:0% +there's very very rapid falloff of light +so we call that the inverse Square law + + align:start position:0% +so we call that the inverse Square law + + + align:start position:0% +so we call that the inverse Square law +so if you're by a window and you have a + + align:start position:0% +so if you're by a window and you have a + + + align:start position:0% +so if you're by a window and you have a +really really nice exposure walking away + + align:start position:0% +really really nice exposure walking away + + + align:start position:0% +really really nice exposure walking away +from the window just a little bit is + + align:start position:0% +from the window just a little bit is + + + align:start position:0% +from the window just a little bit is +enough to end up in in in darkness + + align:start position:0% +enough to end up in in in darkness + + + align:start position:0% +enough to end up in in in darkness +because if you double the distance + + align:start position:0% +because if you double the distance + + + align:start position:0% +because if you double the distance +between the light and the subject you + + align:start position:0% +between the light and the subject you + + + align:start position:0% +between the light and the subject you +only have 1/4 of the intensity as before + + align:start position:0% +only have 1/4 of the intensity as before + + + align:start position:0% +only have 1/4 of the intensity as before +so you're always working against the + + align:start position:0% +so you're always working against the + + + align:start position:0% +so you're always working against the +inverse Square law um in terms of the + + align:start position:0% +inverse Square law um in terms of the + + + align:start position:0% +inverse Square law um in terms of the +intensity so if you need your light to + + align:start position:0% +intensity so if you need your light to + + + align:start position:0% +intensity so if you need your light to +be brighter you can always uh move it + + align:start position:0% +be brighter you can always uh move it + + + align:start position:0% +be brighter you can always uh move it +closer to your subject or get a bigger + + align:start position:0% +closer to your subject or get a bigger + + + align:start position:0% +closer to your subject or get a bigger +light we also talk about the quality of + + align:start position:0% +light we also talk about the quality of + + + align:start position:0% +light we also talk about the quality of +light whether it's hard or soft hard + + align:start position:0% +light whether it's hard or soft hard + + + align:start position:0% +light whether it's hard or soft hard +light has bold Shadows crisp textures + + align:start position:0% +light has bold Shadows crisp textures + + + align:start position:0% +light has bold Shadows crisp textures +we'll look at an example in just a + + align:start position:0% +we'll look at an example in just a + + + align:start position:0% +we'll look at an example in just a +moment and soft light has gentle + + align:start position:0% +moment and soft light has gentle + + + align:start position:0% +moment and soft light has gentle +contrast it's more diffused typically + + align:start position:0% +contrast it's more diffused typically + + + align:start position:0% +contrast it's more diffused typically +very soft or or no Shadows we often talk + + align:start position:0% +very soft or or no Shadows we often talk + + + align:start position:0% +very soft or or no Shadows we often talk +about the direction of light where is it + + align:start position:0% +about the direction of light where is it + + + align:start position:0% +about the direction of light where is it +coming from it refers to the path of the + + align:start position:0% +coming from it refers to the path of the + + + align:start position:0% +coming from it refers to the path of the +light from the source of the light to + + align:start position:0% +light from the source of the light to + + + align:start position:0% +light from the source of the light to +our subject is it coming from the front + + align:start position:0% +our subject is it coming from the front + + + align:start position:0% +our subject is it coming from the front +the side the back under light top light + + align:start position:0% +the side the back under light top light + + + align:start position:0% +the side the back under light top light +and we use these terms to describe where + + align:start position:0% +and we use these terms to describe where + + + align:start position:0% +and we use these terms to describe where +the light uh comes from and of course + + align:start position:0% +the light uh comes from and of course + + + align:start position:0% +the light uh comes from and of course +color like we just saw in the previous + + align:start position:0% +color like we just saw in the previous + + + align:start position:0% +color like we just saw in the previous +slide it's the relative mix of + + align:start position:0% +slide it's the relative mix of + + + align:start position:0% +slide it's the relative mix of +wavelengths and color is often motivated + + align:start position:0% +wavelengths and color is often motivated + + + align:start position:0% +wavelengths and color is often motivated +by the light source so if we want to + + align:start position:0% +by the light source so if we want to + + + align:start position:0% +by the light source so if we want to +depict a sunny day we have sort of + + align:start position:0% +depict a sunny day we have sort of + + + align:start position:0% +depict a sunny day we have sort of +we use yellows and and very very light + + align:start position:0% +we use yellows and and very very light + + + align:start position:0% +we use yellows and and very very light +blues and and white uh it can establish + + align:start position:0% +blues and and white uh it can establish + + + align:start position:0% +blues and and white uh it can establish +mood so if we're going to you know + + align:start position:0% +mood so if we're going to you know + + + align:start position:0% +mood so if we're going to you know +typically period pieces that take places + + align:start position:0% +typically period pieces that take places + + + align:start position:0% +typically period pieces that take places +during the Renaissance happen to have + + align:start position:0% +during the Renaissance happen to have + + + align:start position:0% +during the Renaissance happen to have +sort of a kind of an orange glow about + + align:start position:0% +sort of a kind of an orange glow about + + + align:start position:0% +sort of a kind of an orange glow about +them I just just last night I saw goya's + + align:start position:0% +them I just just last night I saw goya's + + + align:start position:0% +them I just just last night I saw goya's +ghost and was reminded of of how we seem + + align:start position:0% +ghost and was reminded of of how we seem + + + align:start position:0% +ghost and was reminded of of how we seem +to depict certain time periods with + + align:start position:0% +to depict certain time periods with + + + align:start position:0% +to depict certain time periods with +certain color pets and perhaps since the + + align:start position:0% +certain color pets and perhaps since the + + + align:start position:0% +certain color pets and perhaps since the +primary light source uh during the + + align:start position:0% +primary light source uh during the + + + align:start position:0% +primary light source uh during the +Renaissance was candles uh instead of uh + + align:start position:0% +Renaissance was candles uh instead of uh + + + align:start position:0% +Renaissance was candles uh instead of uh +HMI daylight balanced lights like we + + align:start position:0% +HMI daylight balanced lights like we + + + align:start position:0% +HMI daylight balanced lights like we +have on film sets today it it makes a + + align:start position:0% +have on film sets today it it makes a + + + align:start position:0% +have on film sets today it it makes a +lot of a lot of sense that you know in + + align:start position:0% +lot of a lot of sense that you know in + + + align:start position:0% +lot of a lot of sense that you know in +the evenings the world was predominantly + + align:start position:0% +the evenings the world was predominantly + + + align:start position:0% +the evenings the world was predominantly +sort of this golden golden yellow just + + align:start position:0% +sort of this golden golden yellow just + + + align:start position:0% +sort of this golden golden yellow just +want to add one quick thing about that + + align:start position:0% +want to add one quick thing about that + + + align:start position:0% +want to add one quick thing about that +as a documentary filmmaker uh who's + + align:start position:0% +as a documentary filmmaker uh who's + + + align:start position:0% +as a documentary filmmaker uh who's +often working in available light just + + align:start position:0% +often working in available light just + + + align:start position:0% +often working in available light just +remember that those uh qualities that + + align:start position:0% +remember that those uh qualities that + + + align:start position:0% +remember that those uh qualities that +David just talked about apply to + + align:start position:0% +David just talked about apply to + + + align:start position:0% +David just talked about apply to +available light just as much as to + + align:start position:0% +available light just as much as to + + + align:start position:0% +available light just as much as to +lights that you might set up so if you + + align:start position:0% +lights that you might set up so if you + + + align:start position:0% +lights that you might set up so if you +think about the lighting in this room + + align:start position:0% +think about the lighting in this room + + + align:start position:0% +think about the lighting in this room +you know it it's really important to get + + align:start position:0% +you know it it's really important to get + + + align:start position:0% +you know it it's really important to get +start getting getting sensitive to those + + align:start position:0% +start getting getting sensitive to those + + + align:start position:0% +start getting getting sensitive to those +exact same situations where's the light + + align:start position:0% +exact same situations where's the light + + + align:start position:0% +exact same situations where's the light +coming from it's coming from overhead + + align:start position:0% +coming from it's coming from overhead + + + align:start position:0% +coming from it's coming from overhead +lights so what does that mean for the + + align:start position:0% +lights so what does that mean for the + + + align:start position:0% +lights so what does that mean for the +way things look what are the colors of + + align:start position:0% +way things look what are the colors of + + + align:start position:0% +way things look what are the colors of +those lights well they're were + + align:start position:0% +those lights well they're were + + + align:start position:0% +those lights well they're were +fluorescent but if you actually look at + + align:start position:0% +fluorescent but if you actually look at + + + align:start position:0% +fluorescent but if you actually look at +the bulbs you see that there are they + + align:start position:0% +the bulbs you see that there are they + + + align:start position:0% +the bulbs you see that there are they +don't even match from from fixture to + + align:start position:0% +don't even match from from fixture to + + + align:start position:0% +don't even match from from fixture to +fix yeah some of these over here are + + align:start position:0% +fix yeah some of these over here are + + + align:start position:0% +fix yeah some of these over here are +yellow and some of these over here are + + align:start position:0% +yellow and some of these over here are + + + align:start position:0% +yellow and some of these over here are +more towards the white white yeah so so + + align:start position:0% +more towards the white white yeah so so + + + align:start position:0% +more towards the white white yeah so so +those are the kinds of things that you + + align:start position:0% +those are the kinds of things that you + + + align:start position:0% +those are the kinds of things that you +start to become sensitive to uh even as + + align:start position:0% +start to become sensitive to uh even as + + + align:start position:0% +start to become sensitive to uh even as +a documentary filmmaker working without + + align:start position:0% +a documentary filmmaker working without + + + align:start position:0% +a documentary filmmaker working without +lights and all of those things whe the + + align:start position:0% +lights and all of those things whe the + + + align:start position:0% +lights and all of those things whe the +heart + + align:start position:0% +heart + + + align:start position:0% +heart +theity of the theity of the light the + + align:start position:0% +theity of the theity of the light the + + + align:start position:0% +theity of the theity of the light the +dire the color are assessments that you + + align:start position:0% +dire the color are assessments that you + + + align:start position:0% +dire the color are assessments that you +need to make even in situations where + + align:start position:0% +need to make even in situations where + + + align:start position:0% +need to make even in situations where +you're not actually controlling the + + align:start position:0% +you're not actually controlling the + + + align:start position:0% +you're not actually controlling the +light with artificial light producing + + align:start position:0% +light with artificial light producing + + + align:start position:0% +light with artificial light producing +instruments like we're going to work + + align:start position:0% +instruments like we're going to work + + + align:start position:0% +instruments like we're going to work +with later yeah I mean even when I go to + + align:start position:0% +with later yeah I mean even when I go to + + + align:start position:0% +with later yeah I mean even when I go to +do an interview and I'm doing sort of a + + align:start position:0% +do an interview and I'm doing sort of a + + + align:start position:0% +do an interview and I'm doing sort of a +prein and talking to the subject I + + align:start position:0% +prein and talking to the subject I + + + align:start position:0% +prein and talking to the subject I +always say can we talk while we're + + align:start position:0% +always say can we talk while we're + + + align:start position:0% +always say can we talk while we're +walking around because I want to sort of + + align:start position:0% +walking around because I want to sort of + + + align:start position:0% +walking around because I want to sort of +look at the light in the environment and + + align:start position:0% +look at the light in the environment and + + + align:start position:0% +look at the light in the environment and +try to start with something natural + + align:start position:0% +try to start with something natural + + + align:start position:0% +try to start with something natural +exactly I mean just this weekend we were + + align:start position:0% +exactly I mean just this weekend we were + + + align:start position:0% +exactly I mean just this weekend we were +on Martha's Vineyard doing an interview + + align:start position:0% +on Martha's Vineyard doing an interview + + + align:start position:0% +on Martha's Vineyard doing an interview +and we we carted the lighting kit you + + align:start position:0% +and we we carted the lighting kit you + + + align:start position:0% +and we we carted the lighting kit you +know in the trunk of the car we carried + + align:start position:0% +know in the trunk of the car we carried + + + align:start position:0% +know in the trunk of the car we carried +it around we took it across the ferry we + + align:start position:0% +it around we took it across the ferry we + + + align:start position:0% +it around we took it across the ferry we +carried this big huge lighting kit with + + align:start position:0% +carried this big huge lighting kit with + + + align:start position:0% +carried this big huge lighting kit with +us wherever we went and I never cracked + + align:start position:0% +us wherever we went and I never cracked + + + align:start position:0% +us wherever we went and I never cracked +it open because we were able to find + + align:start position:0% +it open because we were able to find + + + align:start position:0% +it open because we were able to find +several positions um to do our + + align:start position:0% +several positions um to do our + + + align:start position:0% +several positions um to do our +interviews where the lighting was + + align:start position:0% +interviews where the lighting was + + + align:start position:0% +interviews where the lighting was +perfect and natural however it was very + + align:start position:0% +perfect and natural however it was very + + + align:start position:0% +perfect and natural however it was very +important for me to know that if we + + align:start position:0% +important for me to know that if we + + + align:start position:0% +important for me to know that if we +didn't find a beautiful spot um we could + + align:start position:0% +didn't find a beautiful spot um we could + + + align:start position:0% +didn't find a beautiful spot um we could +accent uh what we had and supplement + + align:start position:0% +accent uh what we had and supplement + + + align:start position:0% +accent uh what we had and supplement +with with additional light so one of the + + align:start position:0% +with with additional light so one of the + + + align:start position:0% +with with additional light so one of the +big takeaways from this uh lecture today + + align:start position:0% +big takeaways from this uh lecture today + + + align:start position:0% +big takeaways from this uh lecture today +isn't just how to set up lights although + + align:start position:0% +isn't just how to set up lights although + + + align:start position:0% +isn't just how to set up lights although +that's very important but it's also how + + align:start position:0% +that's very important but it's also how + + + align:start position:0% +that's very important but it's also how +to assess the light that you have and + + align:start position:0% +to assess the light that you have and + + + align:start position:0% +to assess the light that you have and +how to make choices about where you + + align:start position:0% +how to make choices about where you + + + align:start position:0% +how to make choices about where you +shoot Things based on those that + + align:start position:0% +shoot Things based on those that + + + align:start position:0% +shoot Things based on those that +assessment that's a very important + + align:start position:0% +assessment that's a very important + + + align:start position:0% +assessment that's a very important +Insight + + align:start position:0% +Insight + + + align:start position:0% +Insight +um so uh very briefly and and and by the + + align:start position:0% +um so uh very briefly and and and by the + + + align:start position:0% +um so uh very briefly and and and by the +way um a PDF with the slides and a PDF + + align:start position:0% +way um a PDF with the slides and a PDF + + + align:start position:0% +way um a PDF with the slides and a PDF +with a uh written note to go with each + + align:start position:0% +with a uh written note to go with each + + + align:start position:0% +with a uh written note to go with each +of the slides will be available as part + + align:start position:0% +of the slides will be available as part + + + align:start position:0% +of the slides will be available as part +of this package um so I don't want to go + + align:start position:0% +of this package um so I don't want to go + + + align:start position:0% +of this package um so I don't want to go +into too much detail here but there are + + align:start position:0% +into too much detail here but there are + + + align:start position:0% +into too much detail here but there are +two primary light models that we use + + align:start position:0% +two primary light models that we use + + + align:start position:0% +two primary light models that we use +when we're talking about light um we + + align:start position:0% +when we're talking about light um we + + + align:start position:0% +when we're talking about light um we +often talk about the additive model so + + align:start position:0% +often talk about the additive model so + + + align:start position:0% +often talk about the additive model so +if we I don't know if you've been to the + + align:start position:0% +if we I don't know if you've been to the + + + align:start position:0% +if we I don't know if you've been to the +Museum of Science but they have this + + align:start position:0% +Museum of Science but they have this + + + align:start position:0% +Museum of Science but they have this +great exhibit where they show a three + + align:start position:0% +great exhibit where they show a three + + + align:start position:0% +great exhibit where they show a three +projectors blue red and green light and + + align:start position:0% +projectors blue red and green light and + + + align:start position:0% +projectors blue red and green light and +where those three uh projected light + + align:start position:0% +where those three uh projected light + + + align:start position:0% +where those three uh projected light +beams intersect you end up with white + + align:start position:0% +beams intersect you end up with white + + + align:start position:0% +beams intersect you end up with white +light which I remember at being around 5 + + align:start position:0% +light which I remember at being around 5 + + + align:start position:0% +light which I remember at being around 5 +years old and seeing this for the first + + align:start position:0% +years old and seeing this for the first + + + align:start position:0% +years old and seeing this for the first +time and I just thought that was + + align:start position:0% +time and I just thought that was + + + align:start position:0% +time and I just thought that was +miraculous like how can those three + + align:start position:0% +miraculous like how can those three + + + align:start position:0% +miraculous like how can those three +colors become white because my + + align:start position:0% +colors become white because my + + + align:start position:0% +colors become white because my +experience with paints was so different + + align:start position:0% +experience with paints was so different + + + align:start position:0% +experience with paints was so different +but that's because my real world + + align:start position:0% +but that's because my real world + + + align:start position:0% +but that's because my real world +experience was the other lighting model + + align:start position:0% +experience was the other lighting model + + + align:start position:0% +experience was the other lighting model +which we'll get to in a moment but that + + align:start position:0% +which we'll get to in a moment but that + + + align:start position:0% +which we'll get to in a moment but that +was sort of magical that you could + + align:start position:0% +was sort of magical that you could + + + align:start position:0% +was sort of magical that you could +combine these colors it turns out if you + + align:start position:0% +combine these colors it turns out if you + + + align:start position:0% +combine these colors it turns out if you +combine red light and its complement + + align:start position:0% +combine red light and its complement + + + align:start position:0% +combine red light and its complement +cyan um you end up with white light as + + align:start position:0% +cyan um you end up with white light as + + + align:start position:0% +cyan um you end up with white light as +well because as long as if you have + + align:start position:0% +well because as long as if you have + + + align:start position:0% +well because as long as if you have +equal amounts of red green and blue + + align:start position:0% +equal amounts of red green and blue + + + align:start position:0% +equal amounts of red green and blue +light then we see what we call White uh + + align:start position:0% +light then we see what we call White uh + + + align:start position:0% +light then we see what we call White uh +and so you can I would suggest uh + + align:start position:0% +and so you can I would suggest uh + + + align:start position:0% +and so you can I would suggest uh +visiting the PDF documents for the Gory + + align:start position:0% +visiting the PDF documents for the Gory + + + align:start position:0% +visiting the PDF documents for the Gory +details now when we're working with uh + + align:start position:0% +details now when we're working with uh + + + align:start position:0% +details now when we're working with uh +often we want to change the color of a + + align:start position:0% +often we want to change the color of a + + + align:start position:0% +often we want to change the color of a +light source and we'll put something + + align:start position:0% +light source and we'll put something + + + align:start position:0% +light source and we'll put something +called a gel over that light and when + + align:start position:0% +called a gel over that light and when + + + align:start position:0% +called a gel over that light and when +we're doing that we're using what we + + align:start position:0% +we're doing that we're using what we + + + align:start position:0% +we're doing that we're using what we +call the subtractive light model in + + align:start position:0% +call the subtractive light model in + + + align:start position:0% +call the subtractive light model in +other words we're filtering out some of + + align:start position:0% +other words we're filtering out some of + + + align:start position:0% +other words we're filtering out some of +the wavelengths and not others so it + + align:start position:0% +the wavelengths and not others so it + + + align:start position:0% +the wavelengths and not others so it +turns out that if you put yellow cyan + + align:start position:0% +turns out that if you put yellow cyan + + + align:start position:0% +turns out that if you put yellow cyan +and magenta gels which happen to be the + + align:start position:0% +and magenta gels which happen to be the + + + align:start position:0% +and magenta gels which happen to be the +complements of red green and blue but if + + align:start position:0% +complements of red green and blue but if + + + align:start position:0% +complements of red green and blue but if +you put those three gels over a light + + align:start position:0% +you put those three gels over a light + + + align:start position:0% +you put those three gels over a light +table for example you will see that you + + align:start position:0% +table for example you will see that you + + + align:start position:0% +table for example you will see that you +end up with this muddy Brown Darkness + + align:start position:0% +end up with this muddy Brown Darkness + + + align:start position:0% +end up with this muddy Brown Darkness +where they overlap because you have + + align:start position:0% +where they overlap because you have + + + align:start position:0% +where they overlap because you have +pretty much filtered out all of uh the + + align:start position:0% +pretty much filtered out all of uh the + + + align:start position:0% +pretty much filtered out all of uh the +light sources um they're not perfect + + align:start position:0% +light sources um they're not perfect + + + align:start position:0% +light sources um they're not perfect +filters so that black will never be + + align:start position:0% +filters so that black will never be + + + align:start position:0% +filters so that black will never be +totally black this is why in like fourcc + + align:start position:0% +totally black this is why in like fourcc + + + align:start position:0% +totally black this is why in like fourcc +color printing of like magazines and + + align:start position:0% +color printing of like magazines and + + + align:start position:0% +color printing of like magazines and +newspapers they use Canan magenta um + + align:start position:0% +newspapers they use Canan magenta um + + + align:start position:0% +newspapers they use Canan magenta um +yellow and black ink for that extra + + align:start position:0% +yellow and black ink for that extra + + + align:start position:0% +yellow and black ink for that extra +Blackness so that's also uses the + + align:start position:0% +Blackness so that's also uses the + + + align:start position:0% +Blackness so that's also uses the +subtractive system so you can either use + + align:start position:0% +subtractive system so you can either use + + + align:start position:0% +subtractive system so you can either use +pigments or you can use gels to subtract + + align:start position:0% +pigments or you can use gels to subtract + + + align:start position:0% +pigments or you can use gels to subtract +particular wavelengths so for example if + + align:start position:0% +particular wavelengths so for example if + + + align:start position:0% +particular wavelengths so for example if +my scene was a little too orangey and I + + align:start position:0% +my scene was a little too orangey and I + + + align:start position:0% +my scene was a little too orangey and I +wanted my light sources to be a little + + align:start position:0% +wanted my light sources to be a little + + + align:start position:0% +wanted my light sources to be a little +less orangey I would be putting + + align:start position:0% +less orangey I would be putting + + + align:start position:0% +less orangey I would be putting +different gradiation of blue gels over + + align:start position:0% +different gradiation of blue gels over + + + align:start position:0% +different gradiation of blue gels over +those lights for example so that's the + + align:start position:0% +those lights for example so that's the + + + align:start position:0% +those lights for example so that's the +subtractive model and it's once you uh + + align:start position:0% +subtractive model and it's once you uh + + + align:start position:0% +subtractive model and it's once you uh +get to know this it makes perfect sense + + align:start position:0% +get to know this it makes perfect sense + + + align:start position:0% +get to know this it makes perfect sense +um and we'll talk a little more about + + align:start position:0% +um and we'll talk a little more about + + + align:start position:0% +um and we'll talk a little more about +blue and and orangey correction gels + + align:start position:0% +blue and and orangey correction gels + + + align:start position:0% +blue and and orangey correction gels +which we have a tendency to use a lot in + + align:start position:0% +which we have a tendency to use a lot in + + + align:start position:0% +which we have a tendency to use a lot in +film video work because we're often + + align:start position:0% +film video work because we're often + + + align:start position:0% +film video work because we're often +correcting or changing the light from + + align:start position:0% +correcting or changing the light from + + + align:start position:0% +correcting or changing the light from +the Cool Blues to the warmer orangey + + align:start position:0% +the Cool Blues to the warmer orangey + + + align:start position:0% +the Cool Blues to the warmer orangey +lights but that's the subtractive model + + align:start position:0% +lights but that's the subtractive model + + + align:start position:0% +lights but that's the subtractive model +at + + align:start position:0% +at + + + align:start position:0% +at +work so um it turns out that video + + align:start position:0% +work so um it turns out that video + + + align:start position:0% +work so um it turns out that video +cameras being technical devices um they + + align:start position:0% +cameras being technical devices um they + + + align:start position:0% +cameras being technical devices um they +don't really know what white is some + + align:start position:0% +don't really know what white is some + + + align:start position:0% +don't really know what white is some +combination of red green and blue + + align:start position:0% +combination of red green and blue + + + align:start position:0% +combination of red green and blue +wavelengths is white but your white + + align:start position:0% +wavelengths is white but your white + + + align:start position:0% +wavelengths is white but your white +might be different than my white might + + align:start position:0% +might be different than my white might + + + align:start position:0% +might be different than my white might +be different than that Sony camera's + + align:start position:0% +be different than that Sony camera's + + + align:start position:0% +be different than that Sony camera's +white so what we typically do when we + + align:start position:0% +white so what we typically do when we + + + align:start position:0% +white so what we typically do when we +white balance the camera is we point the + + align:start position:0% +white balance the camera is we point the + + + align:start position:0% +white balance the camera is we point the +camera and hold up a white card and we + + align:start position:0% +camera and hold up a white card and we + + + align:start position:0% +camera and hold up a white card and we +push the white balance button and we're + + align:start position:0% +push the white balance button and we're + + + align:start position:0% +push the white balance button and we're +telling the camera that particular + + align:start position:0% +telling the camera that particular + + + align:start position:0% +telling the camera that particular +combination of red green and blue + + align:start position:0% +combination of red green and blue + + + align:start position:0% +combination of red green and blue +whatever it happens to be that's my + + align:start position:0% +whatever it happens to be that's my + + + align:start position:0% +whatever it happens to be that's my +white reference and now the camera will + + align:start position:0% +white reference and now the camera will + + + align:start position:0% +white reference and now the camera will +display whatever that card is uh as pure + + align:start position:0% +display whatever that card is uh as pure + + + align:start position:0% +display whatever that card is uh as pure +white well it turns out that + + align:start position:0% +white well it turns out that + + + align:start position:0% +white well it turns out that +um the this sort of relative B balance + + align:start position:0% +um the this sort of relative B balance + + + align:start position:0% +um the this sort of relative B balance +of red green and blue uh the camera sees + + align:start position:0% +of red green and blue uh the camera sees + + + align:start position:0% +of red green and blue uh the camera sees +it as a technical problem to solve and + + align:start position:0% +it as a technical problem to solve and + + + align:start position:0% +it as a technical problem to solve and +very often the perfect white balance of + + align:start position:0% +very often the perfect white balance of + + + align:start position:0% +very often the perfect white balance of +a camera is often maybe a little too too + + align:start position:0% +a camera is often maybe a little too too + + + align:start position:0% +a camera is often maybe a little too too +clean too dry too perfect so a trick + + align:start position:0% +clean too dry too perfect so a trick + + + align:start position:0% +clean too dry too perfect so a trick +that I do is I get something called an + + align:start position:0% +that I do is I get something called an + + + align:start position:0% +that I do is I get something called an +eighth blue gel which is like a pale + + align:start position:0% +eighth blue gel which is like a pale + + + align:start position:0% +eighth blue gel which is like a pale +very pale blue gel and when I white + + align:start position:0% +very pale blue gel and when I white + + + align:start position:0% +very pale blue gel and when I white +balance my camera I hold that pale blue + + align:start position:0% +balance my camera I hold that pale blue + + + align:start position:0% +balance my camera I hold that pale blue +gel over the camera lens I press the + + align:start position:0% +gel over the camera lens I press the + + + align:start position:0% +gel over the camera lens I press the +white balance button and I push away the + + align:start position:0% +white balance button and I push away the + + + align:start position:0% +white balance button and I push away the +G gel and what have I + + align:start position:0% +G gel and what have I + + + align:start position:0% +G gel and what have I +done I have fooled the camera into + + align:start position:0% +done I have fooled the camera into + + + align:start position:0% +done I have fooled the camera into +thinking that there's more blue in the + + align:start position:0% +thinking that there's more blue in the + + + align:start position:0% +thinking that there's more blue in the +world and it compensates by making the + + align:start position:0% +world and it compensates by making the + + + align:start position:0% +world and it compensates by making the +image a teeny bit warmer a little more + + align:start position:0% +image a teeny bit warmer a little more + + + align:start position:0% +image a teeny bit warmer a little more +orangey and flesh tones uh look a lot + + align:start position:0% +orangey and flesh tones uh look a lot + + + align:start position:0% +orangey and flesh tones uh look a lot +better with just a little bit of warmth + + align:start position:0% +better with just a little bit of warmth + + + align:start position:0% +better with just a little bit of warmth +added so this is sort of my like you + + align:start position:0% +added so this is sort of my like you + + + align:start position:0% +added so this is sort of my like you +know little bit of Basil in the sauce uh + + align:start position:0% +know little bit of Basil in the sauce uh + + + align:start position:0% +know little bit of Basil in the sauce uh +for a slightly uh tastier + + align:start position:0% +for a slightly uh tastier + + + align:start position:0% +for a slightly uh tastier +image um you will hear a lot of people + + align:start position:0% +image um you will hear a lot of people + + + align:start position:0% +image um you will hear a lot of people +talk about color temperature this is a + + align:start position:0% +talk about color temperature this is a + + + align:start position:0% +talk about color temperature this is a +method that is used to + + align:start position:0% +method that is used to + + + align:start position:0% +method that is used to +describe what the color of a light + + align:start position:0% +describe what the color of a light + + + align:start position:0% +describe what the color of a light +source is we work so often in this sort + + align:start position:0% +source is we work so often in this sort + + + align:start position:0% +source is we work so often in this sort +of orange to Blue to White Dimension uh + + align:start position:0% +of orange to Blue to White Dimension uh + + + align:start position:0% +of orange to Blue to White Dimension uh +simply because so many of our artificial + + align:start position:0% +simply because so many of our artificial + + + align:start position:0% +simply because so many of our artificial +and natural light sources are in that + + align:start position:0% +and natural light sources are in that + + + align:start position:0% +and natural light sources are in that +range for example fire candle matches + + align:start position:0% +range for example fire candle matches + + + align:start position:0% +range for example fire candle matches +they're all kind of orange sunlight is + + align:start position:0% +they're all kind of orange sunlight is + + + align:start position:0% +they're all kind of orange sunlight is +very + + align:start position:0% +very + + + align:start position:0% +very +blue and so it turns out that um color + + align:start position:0% +blue and so it turns out that um color + + + align:start position:0% +blue and so it turns out that um color +temperature is basically + + align:start position:0% +temperature is basically + + + align:start position:0% +temperature is basically +what temperature do you need to heat up + + align:start position:0% +what temperature do you need to heat up + + + align:start position:0% +what temperature do you need to heat up +this theoretical black body Radiator in + + align:start position:0% +this theoretical black body Radiator in + + + align:start position:0% +this theoretical black body Radiator in +order to get that color well it turns + + align:start position:0% +order to get that color well it turns + + + align:start position:0% +order to get that color well it turns +out in in Practical everyday world uh + + align:start position:0% +out in in Practical everyday world uh + + + align:start position:0% +out in in Practical everyday world uh +that black body radiator that you've + + align:start position:0% +that black body radiator that you've + + + align:start position:0% +that black body radiator that you've +read in cinematography books the + + align:start position:0% +read in cinematography books the + + + align:start position:0% +read in cinematography books the +equivalent think of it as a Tungsten + + align:start position:0% +equivalent think of it as a Tungsten + + + align:start position:0% +equivalent think of it as a Tungsten +filament as a light filament the more + + align:start position:0% +filament as a light filament the more + + + align:start position:0% +filament as a light filament the more +juice you put through that filament the + + align:start position:0% +juice you put through that filament the + + + align:start position:0% +juice you put through that filament the +less orangey it is and the more white it + + align:start position:0% +less orangey it is and the more white it + + + align:start position:0% +less orangey it is and the more white it +becomes of course at some point it + + align:start position:0% +becomes of course at some point it + + + align:start position:0% +becomes of course at some point it +explodes because it's handling too much + + align:start position:0% +explodes because it's handling too much + + + align:start position:0% +explodes because it's handling too much +current but in theory if you heated it + + align:start position:0% +current but in theory if you heated it + + + align:start position:0% +current but in theory if you heated it +up to 9,000 + + align:start position:0% +up to 9,000 + + + align:start position:0% +up to 9,000 +uh degrees you would have the same color + + align:start position:0% +uh degrees you would have the same color + + + align:start position:0% +uh degrees you would have the same color +as hazy sunlight which is very very pale + + align:start position:0% +as hazy sunlight which is very very pale + + + align:start position:0% +as hazy sunlight which is very very pale +blue almost white but if you bring the + + align:start position:0% +blue almost white but if you bring the + + + align:start position:0% +blue almost white but if you bring the +temperature down to 1,700 de Kelvin you + + align:start position:0% +temperature down to 1,700 de Kelvin you + + + align:start position:0% +temperature down to 1,700 de Kelvin you +would have the nice orangey color of a + + align:start position:0% +would have the nice orangey color of a + + + align:start position:0% +would have the nice orangey color of a +match flame so this is sort of this + + align:start position:0% +match flame so this is sort of this + + + align:start position:0% +match flame so this is sort of this +temperature scale from orangey on the + + align:start position:0% +temperature scale from orangey on the + + + align:start position:0% +temperature scale from orangey on the +low temperature end to like almost + + align:start position:0% +low temperature end to like almost + + + align:start position:0% +low temperature end to like almost +perfect white with a slight tinge of + + align:start position:0% +perfect white with a slight tinge of + + + align:start position:0% +perfect white with a slight tinge of +blue on the high end there are two magic + + align:start position:0% +blue on the high end there are two magic + + + align:start position:0% +blue on the high end there are two magic +numbers that you hear in the world of + + align:start position:0% +numbers that you hear in the world of + + + align:start position:0% +numbers that you hear in the world of +white balance 3200 de Kelvin which is + + align:start position:0% +white balance 3200 de Kelvin which is + + + align:start position:0% +white balance 3200 de Kelvin which is +the industry standard for Tungsten + + align:start position:0% +the industry standard for Tungsten + + + align:start position:0% +the industry standard for Tungsten +filament incandescent lights it is the + + align:start position:0% +filament incandescent lights it is the + + + align:start position:0% +filament incandescent lights it is the +standard that for almost 100 years well + + align:start position:0% +standard that for almost 100 years well + + + align:start position:0% +standard that for almost 100 years well +maybe 80 years um film emulsions were + + align:start position:0% +maybe 80 years um film emulsions were + + + align:start position:0% +maybe 80 years um film emulsions were +matched to that color temperature so + + align:start position:0% +matched to that color temperature so + + + align:start position:0% +matched to that color temperature so +that something lit under 3200 de Kelvin + + align:start position:0% +that something lit under 3200 de Kelvin + + + align:start position:0% +that something lit under 3200 de Kelvin +light would look white um there's also + + align:start position:0% +light would look white um there's also + + + align:start position:0% +light would look white um there's also +daylight balanced film so consumer film + + align:start position:0% +daylight balanced film so consumer film + + + align:start position:0% +daylight balanced film so consumer film +was usually uh Balan to 5,500 de Kelvin + + align:start position:0% +was usually uh Balan to 5,500 de Kelvin + + + align:start position:0% +was usually uh Balan to 5,500 de Kelvin +and that's called daylight balance so + + align:start position:0% +and that's called daylight balance so + + + align:start position:0% +and that's called daylight balance so +most electronic Flash + + align:start position:0% +most electronic Flash + + + align:start position:0% +most electronic Flash +um is balanced for daylight and consumer + + align:start position:0% +um is balanced for daylight and consumer + + + align:start position:0% +um is balanced for daylight and consumer +film was always mostly balanced for + + align:start position:0% +film was always mostly balanced for + + + align:start position:0% +film was always mostly balanced for +daylight um and of course now in the era + + align:start position:0% +daylight um and of course now in the era + + + align:start position:0% +daylight um and of course now in the era +of video and digital imaging it's sort + + align:start position:0% +of video and digital imaging it's sort + + + align:start position:0% +of video and digital imaging it's sort +of kind of a little bit of a holdover + + align:start position:0% +of kind of a little bit of a holdover + + + align:start position:0% +of kind of a little bit of a holdover +but we still use these terms because + + align:start position:0% +but we still use these terms because + + + align:start position:0% +but we still use these terms because +film lighting is still um comes + + align:start position:0% +film lighting is still um comes + + + align:start position:0% +film lighting is still um comes +primarily in two flavors tungsten + + align:start position:0% +primarily in two flavors tungsten + + + align:start position:0% +primarily in two flavors tungsten +balanced quartz hallogen lamps LED lamps + + align:start position:0% +balanced quartz hallogen lamps LED lamps + + + align:start position:0% +balanced quartz hallogen lamps LED lamps +fluorescent lamps Etc they're all + + align:start position:0% +fluorescent lamps Etc they're all + + + align:start position:0% +fluorescent lamps Etc they're all +available matched perfectly 3200 de + + align:start position:0% +available matched perfectly 3200 de + + + align:start position:0% +available matched perfectly 3200 de +Kelvin and a new generation of HMI + + align:start position:0% +Kelvin and a new generation of HMI + + + align:start position:0% +Kelvin and a new generation of HMI +daylight balance lights daylight Balan + + align:start position:0% +daylight balance lights daylight Balan + + + align:start position:0% +daylight balance lights daylight Balan +fluorescence daylight balanced LEDs + + align:start position:0% +fluorescence daylight balanced LEDs + + + align:start position:0% +fluorescence daylight balanced LEDs +they're available matched perfectly to + + align:start position:0% +they're available matched perfectly to + + + align:start position:0% +they're available matched perfectly to +5,500 de Kelvin and also many cameras uh + + align:start position:0% +5,500 de Kelvin and also many cameras uh + + + align:start position:0% +5,500 de Kelvin and also many cameras uh +that you may use uh have preset white + + align:start position:0% +that you may use uh have preset white + + + align:start position:0% +that you may use uh have preset white +balance settings so there may be one for + + align:start position:0% +balance settings so there may be one for + + + align:start position:0% +balance settings so there may be one for +daylight there may be one for Tungsten + + align:start position:0% +daylight there may be one for Tungsten + + + align:start position:0% +daylight there may be one for Tungsten +and when you click it to one of those + + align:start position:0% +and when you click it to one of those + + + align:start position:0% +and when you click it to one of those +settings rather than create the white + + align:start position:0% +settings rather than create the white + + + align:start position:0% +settings rather than create the white +balance yourself as David just described + + align:start position:0% +balance yourself as David just described + + + align:start position:0% +balance yourself as David just described +essentially what you're doing is the + + align:start position:0% +essentially what you're doing is the + + + align:start position:0% +essentially what you're doing is the +equivalent of of loading your camera + + align:start position:0% +equivalent of of loading your camera + + + align:start position:0% +equivalent of of loading your camera +with an Emulsion that's balanced to one + + align:start position:0% +with an Emulsion that's balanced to one + + + align:start position:0% +with an Emulsion that's balanced to one +of those presets so 3200 is is in theory + + align:start position:0% +of those presets so 3200 is is in theory + + + align:start position:0% +of those presets so 3200 is is in theory +perfectly balanced for Tungsten light + + align:start position:0% +perfectly balanced for Tungsten light + + + align:start position:0% +perfectly balanced for Tungsten light +and the daylight balance is perfectly + + align:start position:0% +and the daylight balance is perfectly + + + align:start position:0% +and the daylight balance is perfectly +balanced in theory for about 5,500 + + align:start position:0% +balanced in theory for about 5,500 + + + align:start position:0% +balanced in theory for about 5,500 +5600 yeah and it's handy right when you + + align:start position:0% +5600 yeah and it's handy right when you + + + align:start position:0% +5600 yeah and it's handy right when you +buy lighting instruments it's kind of + + align:start position:0% +buy lighting instruments it's kind of + + + align:start position:0% +buy lighting instruments it's kind of +nice that they all sort of match for the + + align:start position:0% +nice that they all sort of match for the + + + align:start position:0% +nice that they all sort of match for the +most part right now if we look at these + + align:start position:0% +most part right now if we look at these + + + align:start position:0% +most part right now if we look at these +three little pictures here something to + + align:start position:0% +three little pictures here something to + + + align:start position:0% +three little pictures here something to +think about outdoor Shadows are + + align:start position:0% +think about outdoor Shadows are + + + align:start position:0% +think about outdoor Shadows are +predominant + + align:start position:0% +predominant + + + align:start position:0% +predominant +blue like if you shoot in in Shadow you + + align:start position:0% +blue like if you shoot in in Shadow you + + + align:start position:0% +blue like if you shoot in in Shadow you +get really really bluish images to our + + align:start position:0% +get really really bluish images to our + + + align:start position:0% +get really really bluish images to our +eyes it may look perfectly neutral but + + align:start position:0% +eyes it may look perfectly neutral but + + + align:start position:0% +eyes it may look perfectly neutral but +to the camera it looks really blue why + + align:start position:0% +to the camera it looks really blue why + + + align:start position:0% +to the camera it looks really blue why +because Shadows doesn't have any direct + + align:start position:0% +because Shadows doesn't have any direct + + + align:start position:0% +because Shadows doesn't have any direct +sun all the lighting in the shadow is + + align:start position:0% +sun all the lighting in the shadow is + + + align:start position:0% +sun all the lighting in the shadow is +coming from the sky which is + + align:start position:0% +coming from the sky which is + + + align:start position:0% +coming from the sky which is +predominantly blue due to the way that + + align:start position:0% +predominantly blue due to the way that + + + align:start position:0% +predominantly blue due to the way that +the light waves are scattered the + + align:start position:0% +the light waves are scattered the + + + align:start position:0% +the light waves are scattered the +different wavelengths are scattered a + + align:start position:0% +different wavelengths are scattered a + + + align:start position:0% +different wavelengths are scattered a +different amount and so sky has a + + align:start position:0% +different amount and so sky has a + + + align:start position:0% +different amount and so sky has a +tendency to be very blue in the middle + + align:start position:0% +tendency to be very blue in the middle + + + align:start position:0% +tendency to be very blue in the middle +picture you see here a mixed environment + + align:start position:0% +picture you see here a mixed environment + + + align:start position:0% +picture you see here a mixed environment +the interior lighting in this museum is + + align:start position:0% +the interior lighting in this museum is + + + align:start position:0% +the interior lighting in this museum is +tungsten incandescent lighting but you + + align:start position:0% +tungsten incandescent lighting but you + + + align:start position:0% +tungsten incandescent lighting but you +have blue daylight streaming through the + + align:start position:0% +have blue daylight streaming through the + + + align:start position:0% +have blue daylight streaming through the +Skylight these are the most difficult + + align:start position:0% +Skylight these are the most difficult + + + align:start position:0% +Skylight these are the most difficult +situations to shoot because you + + align:start position:0% +situations to shoot because you + + + align:start position:0% +situations to shoot because you +basically have to split the difference + + align:start position:0% +basically have to split the difference + + + align:start position:0% +basically have to split the difference +or find some happy medium between the + + align:start position:0% +or find some happy medium between the + + + align:start position:0% +or find some happy medium between the +tungsten lighting and the daylight + + align:start position:0% +tungsten lighting and the daylight + + + align:start position:0% +tungsten lighting and the daylight +lighting because there's no way to + + align:start position:0% +lighting because there's no way to + + + align:start position:0% +lighting because there's no way to +reproduce that the way the eye sees it + + align:start position:0% +reproduce that the way the eye sees it + + + align:start position:0% +reproduce that the way the eye sees it +unless you do some trickery in post- + + align:start position:0% +unless you do some trickery in post- + + + align:start position:0% +unless you do some trickery in post- +production so often we're kind of + + align:start position:0% +production so often we're kind of + + + align:start position:0% +production so often we're kind of +splitting the difference between + + align:start position:0% +splitting the difference between + + + align:start position:0% +splitting the difference between +tungsten interior lighting and and + + align:start position:0% +tungsten interior lighting and and + + + align:start position:0% +tungsten interior lighting and and +daylight streaming through Windows um on + + align:start position:0% +daylight streaming through Windows um on + + + align:start position:0% +daylight streaming through Windows um on +a big b you know big Hollywood budget + + align:start position:0% +a big b you know big Hollywood budget + + + align:start position:0% +a big b you know big Hollywood budget +you know you you'd send a crew to maybe + + align:start position:0% +you know you you'd send a crew to maybe + + + align:start position:0% +you know you you'd send a crew to maybe +gel those windows and put orange gel + + align:start position:0% +gel those windows and put orange gel + + + align:start position:0% +gel those windows and put orange gel +over the windows so that now everything + + align:start position:0% +over the windows so that now everything + + + align:start position:0% +over the windows so that now everything +is is perfectly is perfectly balanced uh + + align:start position:0% +is is perfectly is perfectly balanced uh + + + align:start position:0% +is is perfectly is perfectly balanced uh +as documentary makers we typically don't + + align:start position:0% +as documentary makers we typically don't + + + align:start position:0% +as documentary makers we typically don't +have a crew um that can gel windows and + + align:start position:0% +have a crew um that can gel windows and + + + align:start position:0% +have a crew um that can gel windows and +things like that and so we're in some + + align:start position:0% +things like that and so we're in some + + + align:start position:0% +things like that and so we're in some +ways we have to be much more creative in + + align:start position:0% +ways we have to be much more creative in + + + align:start position:0% +ways we have to be much more creative in +terms of how we choose where we're going + + align:start position:0% +terms of how we choose where we're going + + + align:start position:0% +terms of how we choose where we're going +to set the white balance um for our + + align:start position:0% +to set the white balance um for our + + + align:start position:0% +to set the white balance um for our +scene and of course sunsets are + + align:start position:0% +scene and of course sunsets are + + + align:start position:0% +scene and of course sunsets are +extremely warm due to the scattering + + align:start position:0% +extremely warm due to the scattering + + + align:start position:0% +extremely warm due to the scattering +again the way the light rays are + + align:start position:0% +again the way the light rays are + + + align:start position:0% +again the way the light rays are +scattered and they have a tendency to be + + align:start position:0% +scattered and they have a tendency to be + + + align:start position:0% +scattered and they have a tendency to be +very very warm very very orangey uh and + + align:start position:0% +very very warm very very orangey uh and + + + align:start position:0% +very very warm very very orangey uh and +the more you know crap that we put in + + align:start position:0% +the more you know crap that we put in + + + align:start position:0% +the more you know crap that we put in +the atmosphere the more gorgeous sunsets + + align:start position:0% +the atmosphere the more gorgeous sunsets + + + align:start position:0% +the atmosphere the more gorgeous sunsets +we get which is the one thing I do miss + + align:start position:0% +we get which is the one thing I do miss + + + align:start position:0% +we get which is the one thing I do miss +about living in Los Angeles we had + + align:start position:0% +about living in Los Angeles we had + + + align:start position:0% +about living in Los Angeles we had +intense beautiful orange sunsets so the + + align:start position:0% +intense beautiful orange sunsets so the + + + align:start position:0% +intense beautiful orange sunsets so the +smog is good for + + align:start position:0% +smog is good for + + + align:start position:0% +smog is good for +something um let me relate this to the + + align:start position:0% +something um let me relate this to the + + + align:start position:0% +something um let me relate this to the +color correction that you're going to + + align:start position:0% +color correction that you're going to + + + align:start position:0% +color correction that you're going to +see in post we talked about the green + + align:start position:0% +see in post we talked about the green + + + align:start position:0% +see in post we talked about the green +cyan Dimension and the green magenta + + align:start position:0% +cyan Dimension and the green magenta + + + align:start position:0% +cyan Dimension and the green magenta +Dimension and the blue yellow which is + + align:start position:0% +Dimension and the blue yellow which is + + + align:start position:0% +Dimension and the blue yellow which is +the dimension that we're usually working + + align:start position:0% +the dimension that we're usually working + + + align:start position:0% +the dimension that we're usually working +with and when you're correcting images + + align:start position:0% +with and when you're correcting images + + + align:start position:0% +with and when you're correcting images +in post- production it turns out that + + align:start position:0% +in post- production it turns out that + + + align:start position:0% +in post- production it turns out that +those + + align:start position:0% +those + + + align:start position:0% +those +same the same dimensions that we saw in + + align:start position:0% +same the same dimensions that we saw in + + + align:start position:0% +same the same dimensions that we saw in +the additive uh color model uh come come + + align:start position:0% +the additive uh color model uh come come + + + align:start position:0% +the additive uh color model uh come come +to work here as well right because our + + align:start position:0% +to work here as well right because our + + + align:start position:0% +to work here as well right because our +our LCD monitors were looking at red + + align:start position:0% +our LCD monitors were looking at red + + + align:start position:0% +our LCD monitors were looking at red +green and blue pixels with our cameras + + align:start position:0% +green and blue pixels with our cameras + + + align:start position:0% +green and blue pixels with our cameras +we have red green and blue uh sensitive + + align:start position:0% +we have red green and blue uh sensitive + + + align:start position:0% +we have red green and blue uh sensitive +sensors so if our scene is a little too + + align:start position:0% +sensors so if our scene is a little too + + + align:start position:0% +sensors so if our scene is a little too +yellow or a little too blue we can + + align:start position:0% +yellow or a little too blue we can + + + align:start position:0% +yellow or a little too blue we can +simply adjust in our color correction + + align:start position:0% +simply adjust in our color correction + + + align:start position:0% +simply adjust in our color correction +dial so if you can correct in post- + + align:start position:0% +dial so if you can correct in post- + + + align:start position:0% +dial so if you can correct in post- +production these problems with white + + align:start position:0% +production these problems with white + + + align:start position:0% +production these problems with white +balance why do we worry so much about it + + align:start position:0% +balance why do we worry so much about it + + + align:start position:0% +balance why do we worry so much about it +while we're + + align:start position:0% +while we're + + + align:start position:0% +while we're +shooting the reason is you want to get + + align:start position:0% +shooting the reason is you want to get + + + align:start position:0% +shooting the reason is you want to get +the right the white balance right the + + align:start position:0% +the right the white balance right the + + + align:start position:0% +the right the white balance right the +first time when you shoot because if the + + align:start position:0% +first time when you shoot because if the + + + align:start position:0% +first time when you shoot because if the +scene is excessively blue or the scene + + align:start position:0% +scene is excessively blue or the scene + + + align:start position:0% +scene is excessively blue or the scene +is excessively orange what happens is + + align:start position:0% +is excessively orange what happens is + + + align:start position:0% +is excessively orange what happens is +you're going to overexpose the red + + align:start position:0% +you're going to overexpose the red + + + align:start position:0% +you're going to overexpose the red +Channel or overexpose the blue Channel + + align:start position:0% +Channel or overexpose the blue Channel + + + align:start position:0% +Channel or overexpose the blue Channel +um and what happens is once you + + align:start position:0% +um and what happens is once you + + + align:start position:0% +um and what happens is once you +overexpose that color Channel there's no + + align:start position:0% +overexpose that color Channel there's no + + + align:start position:0% +overexpose that color Channel there's no +information or detail to bring back when + + align:start position:0% +information or detail to bring back when + + + align:start position:0% +information or detail to bring back when +you correct so you will always notice + + align:start position:0% +you correct so you will always notice + + + align:start position:0% +you correct so you will always notice +that a properly white balanced scene you + + align:start position:0% +that a properly white balanced scene you + + + align:start position:0% +that a properly white balanced scene you +can fine-tune the color and get a very + + align:start position:0% +can fine-tune the color and get a very + + + align:start position:0% +can fine-tune the color and get a very +rich sensual image but if you shoot the + + align:start position:0% +rich sensual image but if you shoot the + + + align:start position:0% +rich sensual image but if you shoot the +wrong white balance and you go into + + align:start position:0% +wrong white balance and you go into + + + align:start position:0% +wrong white balance and you go into +correct you're going to notice that your + + align:start position:0% +correct you're going to notice that your + + + align:start position:0% +correct you're going to notice that your +detail looks different and your + + align:start position:0% +detail looks different and your + + + align:start position:0% +detail looks different and your +highlights don't have the same texture + + align:start position:0% +highlights don't have the same texture + + + align:start position:0% +highlights don't have the same texture +and detail because if you shot for + + align:start position:0% +and detail because if you shot for + + + align:start position:0% +and detail because if you shot for +example daylight balanced in a Tungsten + + align:start position:0% +example daylight balanced in a Tungsten + + + align:start position:0% +example daylight balanced in a Tungsten +environment you have completely whacked + + align:start position:0% +environment you have completely whacked + + + align:start position:0% +environment you have completely whacked +out the red Channel relative to the + + align:start position:0% +out the red Channel relative to the + + + align:start position:0% +out the red Channel relative to the +green and uh blue channels right so you + + align:start position:0% +green and uh blue channels right so you + + + align:start position:0% +green and uh blue channels right so you +do want to get it right because having + + align:start position:0% +do want to get it right because having + + + align:start position:0% +do want to get it right because having +one channel way + + align:start position:0% +one channel way + + + align:start position:0% +one channel way +Overexposed you that detail is lost + + align:start position:0% +Overexposed you that detail is lost + + + align:start position:0% +Overexposed you that detail is lost +forever so yes you can correct in post + + align:start position:0% +forever so yes you can correct in post + + + align:start position:0% +forever so yes you can correct in post +but get it right the get at least a good + + align:start position:0% +but get it right the get at least a good + + + align:start position:0% +but get it right the get at least a good +middle of the road starting point in in + + align:start position:0% +middle of the road starting point in in + + + align:start position:0% +middle of the road starting point in in +production I want to revisit quality of + + align:start position:0% +production I want to revisit quality of + + + align:start position:0% +production I want to revisit quality of +light um so on the left we have a scene + + align:start position:0% +light um so on the left we have a scene + + + align:start position:0% +light um so on the left we have a scene +that was shot uh on a cloudy day and + + align:start position:0% +that was shot uh on a cloudy day and + + + align:start position:0% +that was shot uh on a cloudy day and +it's raining um and by the way a little + + align:start position:0% +it's raining um and by the way a little + + + align:start position:0% +it's raining um and by the way a little +trick uh on a cloudy day you would never + + align:start position:0% +trick uh on a cloudy day you would never + + + align:start position:0% +trick uh on a cloudy day you would never +see the raindrops on film so we cheated + + align:start position:0% +see the raindrops on film so we cheated + + + align:start position:0% +see the raindrops on film so we cheated +and we put a very bright HMI backlight + + align:start position:0% +and we put a very bright HMI backlight + + + align:start position:0% +and we put a very bright HMI backlight +daylight balance backlight uh behind the + + align:start position:0% +daylight balance backlight uh behind the + + + align:start position:0% +daylight balance backlight uh behind the +actors so that you would see the + + align:start position:0% +actors so that you would see the + + + align:start position:0% +actors so that you would see the +raindrops so otherwise the lighting is + + align:start position:0% +raindrops so otherwise the lighting is + + + align:start position:0% +raindrops so otherwise the lighting is +completely flat and diffused but we + + align:start position:0% +completely flat and diffused but we + + + align:start position:0% +completely flat and diffused but we +cheated by having a little hard hard + + align:start position:0% +cheated by having a little hard hard + + + align:start position:0% +cheated by having a little hard hard +hard backlight that you don't actually + + align:start position:0% +hard backlight that you don't actually + + + align:start position:0% +hard backlight that you don't actually +see and then the raindrops show up but a + + align:start position:0% +see and then the raindrops show up but a + + + align:start position:0% +see and then the raindrops show up but a +typical overcast day has very very soft + + align:start position:0% +typical overcast day has very very soft + + + align:start position:0% +typical overcast day has very very soft +light the light is coming from many many + + align:start position:0% +light the light is coming from many many + + + align:start position:0% +light the light is coming from many many +different directions and so you don't + + align:start position:0% +different directions and so you don't + + + align:start position:0% +different directions and so you don't +see distinct shadows and it has a + + align:start position:0% +see distinct shadows and it has a + + + align:start position:0% +see distinct shadows and it has a +particular uh maybe soft or even maybe + + align:start position:0% +particular uh maybe soft or even maybe + + + align:start position:0% +particular uh maybe soft or even maybe +even a gloomy feel depending on on the + + align:start position:0% +even a gloomy feel depending on on the + + + align:start position:0% +even a gloomy feel depending on on the +context of the scene um notice on the + + align:start position:0% +context of the scene um notice on the + + + align:start position:0% +context of the scene um notice on the +right in with direct sunlight you get + + align:start position:0% +right in with direct sunlight you get + + + align:start position:0% +right in with direct sunlight you get +very very hard crisp distinct Shadows so + + align:start position:0% +very very hard crisp distinct Shadows so + + + align:start position:0% +very very hard crisp distinct Shadows so +it turns out that what determines the + + align:start position:0% +it turns out that what determines the + + + align:start position:0% +it turns out that what determines the +quality of hard light versus soft light + + align:start position:0% +quality of hard light versus soft light + + + align:start position:0% +quality of hard light versus soft light +has a lot to do with the size of the + + align:start position:0% +has a lot to do with the size of the + + + align:start position:0% +has a lot to do with the size of the +light source so even though the sun is + + align:start position:0% +light source so even though the sun is + + + align:start position:0% +light source so even though the sun is +many times larger than the earth because + + align:start position:0% +many times larger than the earth because + + + align:start position:0% +many times larger than the earth because +it's so far away it's effectively a + + align:start position:0% +it's so far away it's effectively a + + + align:start position:0% +it's so far away it's effectively a +point source and a teeny tiny point + + align:start position:0% +point source and a teeny tiny point + + + align:start position:0% +point source and a teeny tiny point +source is going to give us crisp clean + + align:start position:0% +source is going to give us crisp clean + + + align:start position:0% +source is going to give us crisp clean +Shadows whereas on an overcast day the + + align:start position:0% +Shadows whereas on an overcast day the + + + align:start position:0% +Shadows whereas on an overcast day the +entire cloud cover is like Mother + + align:start position:0% +entire cloud cover is like Mother + + + align:start position:0% +entire cloud cover is like Mother +Nature's beautiful silk it's all light + + align:start position:0% +Nature's beautiful silk it's all light + + + align:start position:0% +Nature's beautiful silk it's all light +coming from all sorts of different + + align:start position:0% +coming from all sorts of different + + + align:start position:0% +coming from all sorts of different +directions and it's soft um and you know + + align:start position:0% +directions and it's soft um and you know + + + align:start position:0% +directions and it's soft um and you know +you can't beat the beautiful quality of + + align:start position:0% +you can't beat the beautiful quality of + + + align:start position:0% +you can't beat the beautiful quality of +of light on a cloudy day and then you + + align:start position:0% +of light on a cloudy day and then you + + + align:start position:0% +of light on a cloudy day and then you +can add a small accent light for a + + align:start position:0% +can add a small accent light for a + + + align:start position:0% +can add a small accent light for a +little bit of Dimension and you'll get + + align:start position:0% +little bit of Dimension and you'll get + + + align:start position:0% +little bit of Dimension and you'll get +Beautiful video images but harsh + + align:start position:0% +Beautiful video images but harsh + + + align:start position:0% +Beautiful video images but harsh +sunlight is pretty hard to deal with + + align:start position:0% +sunlight is pretty hard to deal with + + + align:start position:0% +sunlight is pretty hard to deal with +especially with faces but we'll talk + + align:start position:0% +especially with faces but we'll talk + + + align:start position:0% +especially with faces but we'll talk +about when we do the on Hands-On demo + + align:start position:0% +about when we do the on Hands-On demo + + + align:start position:0% +about when we do the on Hands-On demo +we'll talk about how we can deal with + + align:start position:0% +we'll talk about how we can deal with + + + align:start position:0% +we'll talk about how we can deal with +those issues in bright direct + + align:start position:0% +those issues in bright direct + + + align:start position:0% +those issues in bright direct +sunlight so this is sort of a summary in + + align:start position:0% +sunlight so this is sort of a summary in + + + align:start position:0% +sunlight so this is sort of a summary in +in more detail of what I've just talked + + align:start position:0% +in more detail of what I've just talked + + + align:start position:0% +in more detail of what I've just talked +about but I want to point out that in + + align:start position:0% +about but I want to point out that in + + + align:start position:0% +about but I want to point out that in +terms of soft light sources we're + + align:start position:0% +terms of soft light sources we're + + + align:start position:0% +terms of soft light sources we're +looking at things like soft boxes which + + align:start position:0% +looking at things like soft boxes which + + + align:start position:0% +looking at things like soft boxes which +have a large diffusion material in front + + align:start position:0% +have a large diffusion material in front + + + align:start position:0% +have a large diffusion material in front +of a a hard light um or light bouncing + + align:start position:0% +of a a hard light um or light bouncing + + + align:start position:0% +of a a hard light um or light bouncing +off of a white surface this is how you + + align:start position:0% +off of a white surface this is how you + + + align:start position:0% +off of a white surface this is how you +create soft light um because you can't + + align:start position:0% +create soft light um because you can't + + + align:start position:0% +create soft light um because you can't +always order in a cloudy day and cloudy + + align:start position:0% +always order in a cloudy day and cloudy + + + align:start position:0% +always order in a cloudy day and cloudy +days don't always walk into the building + + align:start position:0% +days don't always walk into the building + + + align:start position:0% +days don't always walk into the building +with you so you may have to create that + + align:start position:0% +with you so you may have to create that + + + align:start position:0% +with you so you may have to create that +soft light with an artificial uh unit um + + align:start position:0% +soft light with an artificial uh unit um + + + align:start position:0% +soft light with an artificial uh unit um +hard light typically Al a a direct + + align:start position:0% +hard light typically Al a a direct + + + align:start position:0% +hard light typically Al a a direct +sunlight a Fel instrument uh any kind of + + align:start position:0% +sunlight a Fel instrument uh any kind of + + + align:start position:0% +sunlight a Fel instrument uh any kind of +open face light with a reflector is + + align:start position:0% +open face light with a reflector is + + + align:start position:0% +open face light with a reflector is +going to give you hard light what's nice + + align:start position:0% +going to give you hard light what's nice + + + align:start position:0% +going to give you hard light what's nice +though is you can always soften a hard + + align:start position:0% +though is you can always soften a hard + + + align:start position:0% +though is you can always soften a hard +light by throwing diffusion material in + + align:start position:0% +light by throwing diffusion material in + + + align:start position:0% +light by throwing diffusion material in +front of it which spreads the beam so + + align:start position:0% +front of it which spreads the beam so + + + align:start position:0% +front of it which spreads the beam so +it's always great to have hard lights in + + align:start position:0% +it's always great to have hard lights in + + + align:start position:0% +it's always great to have hard lights in +your kit because you can always soften + + align:start position:0% +your kit because you can always soften + + + align:start position:0% +your kit because you can always soften +them but once a soft light unit there's + + align:start position:0% +them but once a soft light unit there's + + + align:start position:0% +them but once a soft light unit there's +really no practical way to make it hard + + align:start position:0% +really no practical way to make it hard + + + align:start position:0% +really no practical way to make it hard +again now something that we are you know + + align:start position:0% +again now something that we are you know + + + align:start position:0% +again now something that we are you know +we are entering this world of 3D + + align:start position:0% +we are entering this world of 3D + + + align:start position:0% +we are entering this world of 3D +cinematography and and all of that great + + align:start position:0% +cinematography and and all of that great + + + align:start position:0% +cinematography and and all of that great +stuff um but it turns out that for a + + align:start position:0% +stuff um but it turns out that for a + + + align:start position:0% +stuff um but it turns out that for a +zillion years uh photographers + + align:start position:0% +zillion years uh photographers + + + align:start position:0% +zillion years uh photographers +painters um cinematographers have been + + align:start position:0% +painters um cinematographers have been + + + align:start position:0% +painters um cinematographers have been +creating a sense of three dimensions uh + + align:start position:0% +creating a sense of three dimensions uh + + + align:start position:0% +creating a sense of three dimensions uh +without two cameras and two lenses uh + + align:start position:0% +without two cameras and two lenses uh + + + align:start position:0% +without two cameras and two lenses uh +but using light to do it and the trick + + align:start position:0% +but using light to do it and the trick + + + align:start position:0% +but using light to do it and the trick +is to create these alternating areas of + + align:start position:0% +is to create these alternating areas of + + + align:start position:0% +is to create these alternating areas of +light and dark and light and dark in a + + align:start position:0% +light and dark and light and dark in a + + + align:start position:0% +light and dark and light and dark in a +scene and the great great Prince of + + align:start position:0% +scene and the great great Prince of + + + align:start position:0% +scene and the great great Prince of +Karas skuro was Caravaggio Caravaggio + + align:start position:0% +Karas skuro was Caravaggio Caravaggio + + + align:start position:0% +Karas skuro was Caravaggio Caravaggio +basically introduced black into the + + align:start position:0% +basically introduced black into the + + + align:start position:0% +basically introduced black into the +painter's palet um and created these + + align:start position:0% +painter's palet um and created these + + + align:start position:0% +painter's palet um and created these +really dramatic three-dimensional + + align:start position:0% +really dramatic three-dimensional + + + align:start position:0% +really dramatic three-dimensional +Effects by alternating light and dark + + align:start position:0% +Effects by alternating light and dark + + + align:start position:0% +Effects by alternating light and dark +and light and dark um and we often talk + + align:start position:0% +and light and dark um and we often talk + + + align:start position:0% +and light and dark um and we often talk +about rembrand lighting in in + + align:start position:0% +about rembrand lighting in in + + + align:start position:0% +about rembrand lighting in in +portraiture and that little trademark + + align:start position:0% +portraiture and that little trademark + + + align:start position:0% +portraiture and that little trademark +Little Triangle in the opposite in the + + align:start position:0% +Little Triangle in the opposite in the + + + align:start position:0% +Little Triangle in the opposite in the +cheek opposite the light source um is + + align:start position:0% +cheek opposite the light source um is + + + align:start position:0% +cheek opposite the light source um is +one of the trademarks of of rbrand + + align:start position:0% +one of the trademarks of of rbrand + + + align:start position:0% +one of the trademarks of of rbrand +lighting and it's it's not really about + + align:start position:0% +lighting and it's it's not really about + + + align:start position:0% +lighting and it's it's not really about +the triangle but what the triangle means + + align:start position:0% +the triangle but what the triangle means + + + align:start position:0% +the triangle but what the triangle means +is that once again we've created the + + align:start position:0% +is that once again we've created the + + + align:start position:0% +is that once again we've created the +sense of light on the side of the face + + align:start position:0% +sense of light on the side of the face + + + align:start position:0% +sense of light on the side of the face +and then Darkness behind the nose and + + align:start position:0% +and then Darkness behind the nose and + + + align:start position:0% +and then Darkness behind the nose and +then another area of light and then + + align:start position:0% +then another area of light and then + + + align:start position:0% +then another area of light and then +another area of darkness and that sort + + align:start position:0% +another area of darkness and that sort + + + align:start position:0% +another area of darkness and that sort +of those sort of alternating areas of + + align:start position:0% +of those sort of alternating areas of + + + align:start position:0% +of those sort of alternating areas of +light and dark create this sense of + + align:start position:0% +light and dark create this sense of + + + align:start position:0% +light and dark create this sense of +Dimension so by simply moving the + + align:start position:0% +Dimension so by simply moving the + + + align:start position:0% +Dimension so by simply moving the +direction and the quality of your + + align:start position:0% +direction and the quality of your + + + align:start position:0% +direction and the quality of your +primary light source you can go from + + align:start position:0% +primary light source you can go from + + + align:start position:0% +primary light source you can go from +Flat daytime soap opera lighting to + + align:start position:0% +Flat daytime soap opera lighting to + + + align:start position:0% +Flat daytime soap opera lighting to +dimensional dramatic Frontline interview + + align:start position:0% +dimensional dramatic Frontline interview + + + align:start position:0% +dimensional dramatic Frontline interview +or R Brandt portrait um kind of lighting + + align:start position:0% +or R Brandt portrait um kind of lighting + + + align:start position:0% +or R Brandt portrait um kind of lighting +and it's all about the quality of light + + align:start position:0% +and it's all about the quality of light + + + align:start position:0% +and it's all about the quality of light +and what direction it's coming from and + + align:start position:0% +and what direction it's coming from and + + + align:start position:0% +and what direction it's coming from and +rembrand and carvaggio offer a wonderful + + align:start position:0% +rembrand and carvaggio offer a wonderful + + + align:start position:0% +rembrand and carvaggio offer a wonderful +study um in classic Kos guro + + align:start position:0% +study um in classic Kos guro + + + align:start position:0% +study um in classic Kos guro +lighting so let's talk about uh a few + + align:start position:0% +lighting so let's talk about uh a few + + + align:start position:0% +lighting so let's talk about uh a few +practical real world almost run in gun + + align:start position:0% +practical real world almost run in gun + + + align:start position:0% +practical real world almost run in gun +but not quite carrying three lights uh + + align:start position:0% +but not quite carrying three lights uh + + + align:start position:0% +but not quite carrying three lights uh +sort of + + align:start position:0% +sort of + + + align:start position:0% +sort of +interviews um so + + align:start position:0% +interviews um so + + + align:start position:0% +interviews um so +here here's a here's a frame from a film + + align:start position:0% +here here's a here's a frame from a film + + + align:start position:0% +here here's a here's a frame from a film +uh the lighting is a little more + + align:start position:0% +uh the lighting is a little more + + + align:start position:0% +uh the lighting is a little more +dramatic than you usually see I have a + + align:start position:0% +dramatic than you usually see I have a + + + align:start position:0% +dramatic than you usually see I have a +tendency to air on the side of drama uh + + align:start position:0% +tendency to air on the side of drama uh + + + align:start position:0% +tendency to air on the side of drama uh +we sort of have that little rembrand + + align:start position:0% +we sort of have that little rembrand + + + align:start position:0% +we sort of have that little rembrand +triangle on on her cheek and we can see + + align:start position:0% +triangle on on her cheek and we can see + + + align:start position:0% +triangle on on her cheek and we can see +that there's alternating areas of Light + + align:start position:0% +that there's alternating areas of Light + + + align:start position:0% +that there's alternating areas of Light +Dark Light Dark um in this + + align:start position:0% +Dark Light Dark um in this + + + align:start position:0% +Dark Light Dark um in this +Frame so how did we create this what did + + align:start position:0% +Frame so how did we create this what did + + + align:start position:0% +Frame so how did we create this what did +we do so if we look behind the scenes we + + align:start position:0% +we do so if we look behind the scenes we + + + align:start position:0% +we do so if we look behind the scenes we +see that we have a primary light source + + align:start position:0% +see that we have a primary light source + + + align:start position:0% +see that we have a primary light source +a soft box um the primary light source + + align:start position:0% +a soft box um the primary light source + + + align:start position:0% +a soft box um the primary light source +is typically called the key light our + + align:start position:0% +is typically called the key light our + + + align:start position:0% +is typically called the key light our +primary light source it's off to the + + align:start position:0% +primary light source it's off to the + + + align:start position:0% +primary light source it's off to the +side it's creating that sense of + + align:start position:0% +side it's creating that sense of + + + align:start position:0% +side it's creating that sense of +Dimension + + align:start position:0% +Dimension + + + align:start position:0% +Dimension +um we uh to the right we have what's + + align:start position:0% +um we uh to the right we have what's + + + align:start position:0% +um we uh to the right we have what's +called The Fill light whatever light is + + align:start position:0% +called The Fill light whatever light is + + + align:start position:0% +called The Fill light whatever light is +filling in the shadows created by the + + align:start position:0% +filling in the shadows created by the + + + align:start position:0% +filling in the shadows created by the +key light we call that the fill light + + align:start position:0% +key light we call that the fill light + + + align:start position:0% +key light we call that the fill light +and in the case of this example we're + + align:start position:0% +and in the case of this example we're + + + align:start position:0% +and in the case of this example we're +using a reflector it's called a flex + + align:start position:0% +using a reflector it's called a flex + + + align:start position:0% +using a reflector it's called a flex +fill which you'll see in the live demo + + align:start position:0% +fill which you'll see in the live demo + + + align:start position:0% +fill which you'll see in the live demo +portion of our show um we're using a + + align:start position:0% +portion of our show um we're using a + + + align:start position:0% +portion of our show um we're using a +flex fill to reflect some of that key + + align:start position:0% +flex fill to reflect some of that key + + + align:start position:0% +flex fill to reflect some of that key +light back onto the subject so that the + + align:start position:0% +light back onto the subject so that the + + + align:start position:0% +light back onto the subject so that the +dark side of the face doesn't become + + align:start position:0% +dark side of the face doesn't become + + + align:start position:0% +dark side of the face doesn't become +totally dark um and then slightly off + + align:start position:0% +totally dark um and then slightly off + + + align:start position:0% +totally dark um and then slightly off +the top of the frame there we have a + + align:start position:0% +the top of the frame there we have a + + + align:start position:0% +the top of the frame there we have a +backlight and we're using the backlight + + align:start position:0% +backlight and we're using the backlight + + + align:start position:0% +backlight and we're using the backlight +to create a little bit if we go back to + + align:start position:0% +to create a little bit if we go back to + + + align:start position:0% +to create a little bit if we go back to +this image there's a little bit of light + + align:start position:0% +this image there's a little bit of light + + + align:start position:0% +this image there's a little bit of light +on her shoulder and there's a little bit + + align:start position:0% +on her shoulder and there's a little bit + + + align:start position:0% +on her shoulder and there's a little bit +of light on on her hair that's coming + + align:start position:0% +of light on on her hair that's coming + + + align:start position:0% +of light on on her hair that's coming +from behind her so what we did is we + + align:start position:0% +from behind her so what we did is we + + + align:start position:0% +from behind her so what we did is we +have a 300 watt Fel we'll talk a little + + align:start position:0% +have a 300 watt Fel we'll talk a little + + + align:start position:0% +have a 300 watt Fel we'll talk a little +more about frels + + align:start position:0% +more about frels + + + align:start position:0% +more about frels +later um behind her that's just giving a + + align:start position:0% +later um behind her that's just giving a + + + align:start position:0% +later um behind her that's just giving a +little bit of light coming from the back + + align:start position:0% +little bit of light coming from the back + + + align:start position:0% +little bit of light coming from the back +which creates a little bit of additional + + align:start position:0% +which creates a little bit of additional + + + align:start position:0% +which creates a little bit of additional +dimensionality and separation from the + + align:start position:0% +dimensionality and separation from the + + + align:start position:0% +dimensionality and separation from the +background but in this particular frame + + align:start position:0% +background but in this particular frame + + + align:start position:0% +background but in this particular frame +it's very subtle if you overdo the + + align:start position:0% +it's very subtle if you overdo the + + + align:start position:0% +it's very subtle if you overdo the +backlight all of a sudden things start + + align:start position:0% +backlight all of a sudden things start + + + align:start position:0% +backlight all of a sudden things start +to look theatrical we're in the middle + + align:start position:0% +to look theatrical we're in the middle + + + align:start position:0% +to look theatrical we're in the middle +of a play we're not in the middle of a + + align:start position:0% +of a play we're not in the middle of a + + + align:start position:0% +of a play we're not in the middle of a +documentary anymore so you have to be + + align:start position:0% +documentary anymore so you have to be + + + align:start position:0% +documentary anymore so you have to be +careful because the backlight is a very + + align:start position:0% +careful because the backlight is a very + + + align:start position:0% +careful because the backlight is a very +artificial element um but if done subtly + + align:start position:0% +artificial element um but if done subtly + + + align:start position:0% +artificial element um but if done subtly +it can be it can look very much like a + + align:start position:0% +it can be it can look very much like a + + + align:start position:0% +it can be it can look very much like a +natural element and give a little bit of + + align:start position:0% +natural element and give a little bit of + + + align:start position:0% +natural element and give a little bit of +separation and we can see a little bit + + align:start position:0% +separation and we can see a little bit + + + align:start position:0% +separation and we can see a little bit +of shine in the hair uh and then we have + + align:start position:0% +of shine in the hair uh and then we have + + + align:start position:0% +of shine in the hair uh and then we have +a fourth light because remember we've + + align:start position:0% +a fourth light because remember we've + + + align:start position:0% +a fourth light because remember we've +got the key light The Fill light filling + + align:start position:0% +got the key light The Fill light filling + + + align:start position:0% +got the key light The Fill light filling +in the shadows caused by the key light a + + align:start position:0% +in the shadows caused by the key light a + + + align:start position:0% +in the shadows caused by the key light a +back light coming from behind the + + align:start position:0% +back light coming from behind the + + + align:start position:0% +back light coming from behind the +subject offering a little bit of + + align:start position:0% +subject offering a little bit of + + + align:start position:0% +subject offering a little bit of +Dimension and there's a fourth light + + align:start position:0% +Dimension and there's a fourth light + + + align:start position:0% +Dimension and there's a fourth light +that we often talk about and that's the + + align:start position:0% +that we often talk about and that's the + + + align:start position:0% +that we often talk about and that's the +background light not to be confused with + + align:start position:0% +background light not to be confused with + + + align:start position:0% +background light not to be confused with +the backl now the background light in + + align:start position:0% +the backl now the background light in + + + align:start position:0% +the backl now the background light in +this particular scene is being provided + + align:start position:0% +this particular scene is being provided + + + align:start position:0% +this particular scene is being provided +by the window in the upper right hand + + align:start position:0% +by the window in the upper right hand + + + align:start position:0% +by the window in the upper right hand +corner I've covered up part of the + + align:start position:0% +corner I've covered up part of the + + + align:start position:0% +corner I've covered up part of the +window with foam core um but I've left + + align:start position:0% +window with foam core um but I've left + + + align:start position:0% +window with foam core um but I've left +the rest of the window open to kind of + + align:start position:0% +the rest of the window open to kind of + + + align:start position:0% +the rest of the window open to kind of +add this sort of overall light so if we + + align:start position:0% +add this sort of overall light so if we + + + align:start position:0% +add this sort of overall light so if we +go oops if we go back + + align:start position:0% +go oops if we go back + + + align:start position:0% +go oops if we go back +here the overall ambient light that's + + align:start position:0% +here the overall ambient light that's + + + align:start position:0% +here the overall ambient light that's +lighting the back wall is a mixture of + + align:start position:0% +lighting the back wall is a mixture of + + + align:start position:0% +lighting the back wall is a mixture of +what's coming in from the window and + + align:start position:0% +what's coming in from the window and + + + align:start position:0% +what's coming in from the window and +what's coming in from the key light cuz + + align:start position:0% +what's coming in from the key light cuz + + + align:start position:0% +what's coming in from the key light cuz +we don't want the background we want the + + align:start position:0% +we don't want the background we want the + + + align:start position:0% +we don't want the background we want the +background to be a little bit darker + + align:start position:0% +background to be a little bit darker + + + align:start position:0% +background to be a little bit darker +than the subject so the subject kind of + + align:start position:0% +than the subject so the subject kind of + + + align:start position:0% +than the subject so the subject kind of +um pops out as the main element CU you + + align:start position:0% +um pops out as the main element CU you + + + align:start position:0% +um pops out as the main element CU you +know one of the things that we're + + align:start position:0% +know one of the things that we're + + + align:start position:0% +know one of the things that we're +thinking about when we're lighting is + + align:start position:0% +thinking about when we're lighting is + + + align:start position:0% +thinking about when we're lighting is +we're drawing attention we're using + + align:start position:0% +we're drawing attention we're using + + + align:start position:0% +we're drawing attention we're using +lighting to draw the viewer's attention + + align:start position:0% +lighting to draw the viewer's attention + + + align:start position:0% +lighting to draw the viewer's attention +to what the important things are in the + + align:start position:0% +to what the important things are in the + + + align:start position:0% +to what the important things are in the +frame but we don't want to completely + + align:start position:0% +frame but we don't want to completely + + + align:start position:0% +frame but we don't want to completely +obscure the background because while the + + align:start position:0% +obscure the background because while the + + + align:start position:0% +obscure the background because while the +interview subject may be the subject of + + align:start position:0% +interview subject may be the subject of + + + align:start position:0% +interview subject may be the subject of +our image there's also a predicate just + + align:start position:0% +our image there's also a predicate just + + + align:start position:0% +our image there's also a predicate just +like any good sentence and so the + + align:start position:0% +like any good sentence and so the + + + align:start position:0% +like any good sentence and so the +context here is the editing room is the + + align:start position:0% +context here is the editing room is the + + + align:start position:0% +context here is the editing room is the +equipment that's in the room so we want + + align:start position:0% +equipment that's in the room so we want + + + align:start position:0% +equipment that's in the room so we want +to feature that too but we want it to + + align:start position:0% +to feature that too but we want it to + + + align:start position:0% +to feature that too but we want it to +feel like it's part of the background + + align:start position:0% +feel like it's part of the background + + + align:start position:0% +feel like it's part of the background +both in terms of intensity and in terms + + align:start position:0% +both in terms of intensity and in terms + + + align:start position:0% +both in terms of intensity and in terms +of of placement um so a little bit of + + align:start position:0% +of of placement um so a little bit of + + + align:start position:0% +of of placement um so a little bit of +background light is being provided by + + align:start position:0% +background light is being provided by + + + align:start position:0% +background light is being provided by +both spill from the key as well as some + + align:start position:0% +both spill from the key as well as some + + + align:start position:0% +both spill from the key as well as some +of the windows so what we did is we + + align:start position:0% +of the windows so what we did is we + + + align:start position:0% +of the windows so what we did is we +varied that foam core until we had just + + align:start position:0% +varied that foam core until we had just + + + align:start position:0% +varied that foam core until we had just +the right amount of ambient light in the + + align:start position:0% +the right amount of ambient light in the + + + align:start position:0% +the right amount of ambient light in the +room and that's where we placed it so + + align:start position:0% +room and that's where we placed it so + + + align:start position:0% +room and that's where we placed it so +very often you can use nature natural + + align:start position:0% +very often you can use nature natural + + + align:start position:0% +very often you can use nature natural +light as as as one of your light units I + + align:start position:0% +light as as as one of your light units I + + + align:start position:0% +light as as as one of your light units I +like to work with what's natural I knew + + align:start position:0% +like to work with what's natural I knew + + + align:start position:0% +like to work with what's natural I knew +that that was facing in a direction that + + align:start position:0% +that that was facing in a direction that + + + align:start position:0% +that that was facing in a direction that +we wouldn't have direct sun shining in + + align:start position:0% +we wouldn't have direct sun shining in + + + align:start position:0% +we wouldn't have direct sun shining in +the room anytime during the interview so + + align:start position:0% +the room anytime during the interview so + + + align:start position:0% +the room anytime during the interview so +it's always good to know what direction + + align:start position:0% +it's always good to know what direction + + + align:start position:0% +it's always good to know what direction +the sun's going in so we could rely for + + align:start position:0% +the sun's going in so we could rely for + + + align:start position:0% +the sun's going in so we could rely for +two hours that we would have Skylight + + align:start position:0% +two hours that we would have Skylight + + + align:start position:0% +two hours that we would have Skylight +but no direct sunlight to kind of mess + + align:start position:0% +but no direct sunlight to kind of mess + + + align:start position:0% +but no direct sunlight to kind of mess +up our scene so if I can bring Mother + + align:start position:0% +up our scene so if I can bring Mother + + + align:start position:0% +up our scene so if I can bring Mother +Nature into the lighting equation that's + + align:start position:0% +Nature into the lighting equation that's + + + align:start position:0% +Nature into the lighting equation that's +great if I could do this whole setup + + align:start position:0% +great if I could do this whole setup + + + align:start position:0% +great if I could do this whole setup +without any artificial light that would + + align:start position:0% +without any artificial light that would + + + align:start position:0% +without any artificial light that would +be even better um but that doesn't + + align:start position:0% +be even better um but that doesn't + + + align:start position:0% +be even better um but that doesn't +always work out that + + align:start position:0% +always work out that + + + align:start position:0% +always work out that +way so I'm going to basically kind of + + align:start position:0% +way so I'm going to basically kind of + + + align:start position:0% +way so I'm going to basically kind of +review what we just talked about in in + + align:start position:0% +review what we just talked about in in + + + align:start position:0% +review what we just talked about in in +four different environments so a typical + + align:start position:0% +four different environments so a typical + + + align:start position:0% +four different environments so a typical +formal interview is what you just saw in + + align:start position:0% +formal interview is what you just saw in + + + align:start position:0% +formal interview is what you just saw in +this particular uh situation um I saw + + align:start position:0% +this particular uh situation um I saw + + + align:start position:0% +this particular uh situation um I saw +that there were these beautiful French + + align:start position:0% +that there were these beautiful French + + + align:start position:0% +that there were these beautiful French +doors in the room I said aha we're going + + align:start position:0% +doors in the room I said aha we're going + + + align:start position:0% +doors in the room I said aha we're going +to use that um as our background because + + align:start position:0% +to use that um as our background because + + + align:start position:0% +to use that um as our background because +it kind of you know it looks nice it + + align:start position:0% +it kind of you know it looks nice it + + + align:start position:0% +it kind of you know it looks nice it +adds a little bit of Dimension um but I + + align:start position:0% +adds a little bit of Dimension um but I + + + align:start position:0% +adds a little bit of Dimension um but I +want the background to recede and I want + + align:start position:0% +want the background to recede and I want + + + align:start position:0% +want the background to recede and I want +the foreground to move forward well it + + align:start position:0% +the foreground to move forward well it + + + align:start position:0% +the foreground to move forward well it +turns out that your warmer colors have a + + align:start position:0% +turns out that your warmer colors have a + + + align:start position:0% +turns out that your warmer colors have a +tendency to move forward and your cooler + + align:start position:0% +tendency to move forward and your cooler + + + align:start position:0% +tendency to move forward and your cooler +colors like your Blues have a tendency + + align:start position:0% +colors like your Blues have a tendency + + + align:start position:0% +colors like your Blues have a tendency +to kind of fall into the background so + + align:start position:0% +to kind of fall into the background so + + + align:start position:0% +to kind of fall into the background so +what did I do is I put a background + + align:start position:0% +what did I do is I put a background + + + align:start position:0% +what did I do is I put a background +light behind the lace curtains behind + + align:start position:0% +light behind the lace curtains behind + + + align:start position:0% +light behind the lace curtains behind +those French doors with a half blue gel + + align:start position:0% +those French doors with a half blue gel + + + align:start position:0% +those French doors with a half blue gel +so that's giving me the kind of the + + align:start position:0% +so that's giving me the kind of the + + + align:start position:0% +so that's giving me the kind of the +bluish background and of course she's + + align:start position:0% +bluish background and of course she's + + + align:start position:0% +bluish background and of course she's +being lit by a soft box something called + + align:start position:0% +being lit by a soft box something called + + + align:start position:0% +being lit by a soft box something called +a Rea light from l so the primary key in + + align:start position:0% +a Rea light from l so the primary key in + + + align:start position:0% +a Rea light from l so the primary key in +this case is is a you know it's a soft + + align:start position:0% +this case is is a you know it's a soft + + + align:start position:0% +this case is is a you know it's a soft +LGE relatively mediumsized I guess soft + + align:start position:0% +LGE relatively mediumsized I guess soft + + + align:start position:0% +LGE relatively mediumsized I guess soft +light and once again we're using the + + align:start position:0% +light and once again we're using the + + + align:start position:0% +light and once again we're using the +reflector flexfill as our full light + + align:start position:0% +reflector flexfill as our full light + + + align:start position:0% +reflector flexfill as our full light +because you know the less wires and the + + align:start position:0% +because you know the less wires and the + + + align:start position:0% +because you know the less wires and the +less light that I can travel with the + + align:start position:0% +less light that I can travel with the + + + align:start position:0% +less light that I can travel with the +better so we we basically lit this + + align:start position:0% +better so we we basically lit this + + + align:start position:0% +better so we we basically lit this +situation with two lights plus the + + align:start position:0% +situation with two lights plus the + + + align:start position:0% +situation with two lights plus the +ambient spill that was coming from the + + align:start position:0% +ambient spill that was coming from the + + + align:start position:0% +ambient spill that was coming from the +windows in the middle of the day so this + + align:start position:0% +windows in the middle of the day so this + + + align:start position:0% +windows in the middle of the day so this +was once again um a 3point lighting + + align:start position:0% +was once again um a 3point lighting + + + align:start position:0% +was once again um a 3point lighting +setup but we're only using two fixtures + + align:start position:0% +setup but we're only using two fixtures + + + align:start position:0% +setup but we're only using two fixtures +because we're making use of the natural + + align:start position:0% +because we're making use of the natural + + + align:start position:0% +because we're making use of the natural +light that was available in this living + + align:start position:0% +light that was available in this living + + + align:start position:0% +light that was available in this living +room uh at at the time and the key is + + align:start position:0% +room uh at at the time and the key is + + + align:start position:0% +room uh at at the time and the key is +relatively soft and you can tell that by + + align:start position:0% +relatively soft and you can tell that by + + + align:start position:0% +relatively soft and you can tell that by +the way the light wraps around the face + + align:start position:0% +the way the light wraps around the face + + + align:start position:0% +the way the light wraps around the face +so notice how even though that there's a + + align:start position:0% +so notice how even though that there's a + + + align:start position:0% +so notice how even though that there's a +shadow uh where her nose is and there's + + align:start position:0% +shadow uh where her nose is and there's + + + align:start position:0% +shadow uh where her nose is and there's +a shadow on the right hand side of her + + align:start position:0% +a shadow on the right hand side of her + + + align:start position:0% +a shadow on the right hand side of her +face there is a smooth gradient from the + + align:start position:0% +face there is a smooth gradient from the + + + align:start position:0% +face there is a smooth gradient from the +light to the dark area and we call that + + align:start position:0% +light to the dark area and we call that + + + align:start position:0% +light to the dark area and we call that +the way the light wraps around the face + + align:start position:0% +the way the light wraps around the face + + + align:start position:0% +the way the light wraps around the face +um if we had a we'll see now in this + + align:start position:0% +um if we had a we'll see now in this + + + align:start position:0% +um if we had a we'll see now in this +other interview we have a harsh overhead + + align:start position:0% +other interview we have a harsh overhead + + + align:start position:0% +other interview we have a harsh overhead +standard Edison based light bulb 150 W + + align:start position:0% +standard Edison based light bulb 150 W + + + align:start position:0% +standard Edison based light bulb 150 W +screw light bulb in the top of the room + + align:start position:0% +screw light bulb in the top of the room + + + align:start position:0% +screw light bulb in the top of the room +there's also a couple of small quartz + + align:start position:0% +there's also a couple of small quartz + + + align:start position:0% +there's also a couple of small quartz +lights that are lighting the uh the toy + + align:start position:0% +lights that are lighting the uh the toy + + + align:start position:0% +lights that are lighting the uh the toy +collection cabinet behind her um but + + align:start position:0% +collection cabinet behind her um but + + + align:start position:0% +collection cabinet behind her um but +this is basically working under very + + align:start position:0% +this is basically working under very + + + align:start position:0% +this is basically working under very +harsh um nonoptimal lighting conditions + + align:start position:0% +harsh um nonoptimal lighting conditions + + + align:start position:0% +harsh um nonoptimal lighting conditions +um and so it's not at all + + align:start position:0% +um and so it's not at all + + + align:start position:0% +um and so it's not at all +flattering in in some ways um + + align:start position:0% +flattering in in some ways um + + + align:start position:0% +flattering in in some ways um +we're we're not doing our subject + + align:start position:0% +we're we're not doing our subject + + + align:start position:0% +we're we're not doing our subject +justice of course in this film she was + + align:start position:0% +justice of course in this film she was + + + align:start position:0% +justice of course in this film she was +sort of playfully playing the role of + + align:start position:0% +sort of playfully playing the role of + + + align:start position:0% +sort of playfully playing the role of +the bad guy um so the lighting kind of + + align:start position:0% +the bad guy um so the lighting kind of + + + align:start position:0% +the bad guy um so the lighting kind of +worked dramatically for those purposes + + align:start position:0% +worked dramatically for those purposes + + + align:start position:0% +worked dramatically for those purposes +um so I decided to go with it rather + + align:start position:0% +um so I decided to go with it rather + + + align:start position:0% +um so I decided to go with it rather +than bringing the lighting kit out uh + + align:start position:0% +than bringing the lighting kit out uh + + + align:start position:0% +than bringing the lighting kit out uh +because we said it looks okay we want + + align:start position:0% +because we said it looks okay we want + + + align:start position:0% +because we said it looks okay we want +this to kind of be raw and harsh uh once + + align:start position:0% +this to kind of be raw and harsh uh once + + + align:start position:0% +this to kind of be raw and harsh uh once +again it's all about context what does + + align:start position:0% +again it's all about context what does + + + align:start position:0% +again it's all about context what does +the lighting do for your storytelling uh + + align:start position:0% +the lighting do for your storytelling uh + + + align:start position:0% +the lighting do for your storytelling uh +it it was okay uh for a character making + + align:start position:0% +it it was okay uh for a character making + + + align:start position:0% +it it was okay uh for a character making +certain harsh comments to be kind of in + + align:start position:0% +certain harsh comments to be kind of in + + + align:start position:0% +certain harsh comments to be kind of in +slightly harsh uh light at least it + + align:start position:0% +slightly harsh uh light at least it + + + align:start position:0% +slightly harsh uh light at least it +worked uh for me uh creatively in this + + align:start position:0% +worked uh for me uh creatively in this + + + align:start position:0% +worked uh for me uh creatively in this +particular scene but most of the time + + align:start position:0% +particular scene but most of the time + + + align:start position:0% +particular scene but most of the time +that's not what I want here's another + + align:start position:0% +that's not what I want here's another + + + align:start position:0% +that's not what I want here's another +situation which is not at all optimal + + align:start position:0% +situation which is not at all optimal + + + align:start position:0% +situation which is not at all optimal +this is + + align:start position:0% +this is + + + align:start position:0% +this is +handheld um + + align:start position:0% +handheld um + + + align:start position:0% +handheld um +impromptu uh conversation with a + + align:start position:0% +impromptu uh conversation with a + + + align:start position:0% +impromptu uh conversation with a +character in the middle of an art + + align:start position:0% +character in the middle of an art + + + align:start position:0% +character in the middle of an art +opening um it the the the lighting was + + align:start position:0% +opening um it the the the lighting was + + + align:start position:0% +opening um it the the the lighting was +mixed window light dark Corners + + align:start position:0% +mixed window light dark Corners + + + align:start position:0% +mixed window light dark Corners +incandescent lights harsh really really + + align:start position:0% +incandescent lights harsh really really + + + align:start position:0% +incandescent lights harsh really really +difficult I looked around the room and I + + align:start position:0% +difficult I looked around the room and I + + + align:start position:0% +difficult I looked around the room and I +go oh my God what are we going to do um + + align:start position:0% +go oh my God what are we going to do um + + + align:start position:0% +go oh my God what are we going to do um +and then I saw this big window and I + + align:start position:0% +and then I saw this big window and I + + + align:start position:0% +and then I saw this big window and I +said do you mind standing next to the + + align:start position:0% +said do you mind standing next to the + + + align:start position:0% +said do you mind standing next to the +big window so out of the darkness I was + + align:start position:0% +big window so out of the darkness I was + + + align:start position:0% +big window so out of the darkness I was +able to move the subject so that uh she + + align:start position:0% +able to move the subject so that uh she + + + align:start position:0% +able to move the subject so that uh she +was being lit by um window + + align:start position:0% +was being lit by um window + + + align:start position:0% +was being lit by um window +light so here's me no lights no kit + + align:start position:0% +light so here's me no lights no kit + + + align:start position:0% +light so here's me no lights no kit +camera in my right hand microphone in + + align:start position:0% +camera in my right hand microphone in + + + align:start position:0% +camera in my right hand microphone in +the left hand um let's move by the + + align:start position:0% +the left hand um let's move by the + + + align:start position:0% +the left hand um let's move by the +window so sometimes you just got to look + + align:start position:0% +window so sometimes you just got to look + + + align:start position:0% +window so sometimes you just got to look +around and see where the light looks + + align:start position:0% +around and see where the light looks + + + align:start position:0% +around and see where the light looks +best and move your subject into um that + + align:start position:0% +best and move your subject into um that + + + align:start position:0% +best and move your subject into um that +area and it's remembering again to apply + + align:start position:0% +area and it's remembering again to apply + + + align:start position:0% +area and it's remembering again to apply +some of the principles that you're + + align:start position:0% +some of the principles that you're + + + align:start position:0% +some of the principles that you're +talking about in a situation where you + + align:start position:0% +talking about in a situation where you + + + align:start position:0% +talking about in a situation where you +don't have lights uh but still keeping + + align:start position:0% +don't have lights uh but still keeping + + + align:start position:0% +don't have lights uh but still keeping +in mind all of the things that that that + + align:start position:0% +in mind all of the things that that that + + + align:start position:0% +in mind all of the things that that that +were discussing the intensity of the + + align:start position:0% +were discussing the intensity of the + + + align:start position:0% +were discussing the intensity of the +light the direction of the light the the + + align:start position:0% +light the direction of the light the the + + + align:start position:0% +light the direction of the light the the +quality of the light the the + + align:start position:0% +quality of the light the the + + + align:start position:0% +quality of the light the the +um mhm uh color of the light and and + + align:start position:0% +um mhm uh color of the light and and + + + align:start position:0% +um mhm uh color of the light and and +making choices on on where you conduct + + align:start position:0% +making choices on on where you conduct + + + align:start position:0% +making choices on on where you conduct +your interviews or do your shooting + + align:start position:0% +your interviews or do your shooting + + + align:start position:0% +your interviews or do your shooting +exactly based on those principles uh you + + align:start position:0% +exactly based on those principles uh you + + + align:start position:0% +exactly based on those principles uh you +know in fact in this case I didn't even + + align:start position:0% +know in fact in this case I didn't even + + + align:start position:0% +know in fact in this case I didn't even +even have time to do my eighth blue + + align:start position:0% +even have time to do my eighth blue + + + align:start position:0% +even have time to do my eighth blue +trick I just set the preset to Daylight + + align:start position:0% +trick I just set the preset to Daylight + + + align:start position:0% +trick I just set the preset to Daylight +because I knew that + + align:start position:0% +because I knew that + + + align:start position:0% +because I knew that +the window was pretty much daylight and + + align:start position:0% +the window was pretty much daylight and + + + align:start position:0% +the window was pretty much daylight and +of course you're getting the little bit + + align:start position:0% +of course you're getting the little bit + + + align:start position:0% +of course you're getting the little bit +of triangle on the cheek because of her + + align:start position:0% +of triangle on the cheek because of her + + + align:start position:0% +of triangle on the cheek because of her +position relative relative to the light + + align:start position:0% +position relative relative to the light + + + align:start position:0% +position relative relative to the light +so + + align:start position:0% +so + + + align:start position:0% +so +uh that is what I'm always paying + + align:start position:0% +uh that is what I'm always paying + + + align:start position:0% +uh that is what I'm always paying +attention to I watch somebody talking + + align:start position:0% +attention to I watch somebody talking + + + align:start position:0% +attention to I watch somebody talking +and I go am I am I seeing that + + align:start position:0% +and I go am I am I seeing that + + + align:start position:0% +and I go am I am I seeing that +dimensional light sometimes I just and + + align:start position:0% +dimensional light sometimes I just and + + + align:start position:0% +dimensional light sometimes I just and +in fact when I'm doing an impromptu + + align:start position:0% +in fact when I'm doing an impromptu + + + align:start position:0% +in fact when I'm doing an impromptu +interview like this I won't ask the + + align:start position:0% +interview like this I won't ask the + + + align:start position:0% +interview like this I won't ask the +subject to change very often I will + + align:start position:0% +subject to change very often I will + + + align:start position:0% +subject to change very often I will +move and watch how the lighting changes + + align:start position:0% +move and watch how the lighting changes + + + align:start position:0% +move and watch how the lighting changes +on their face because sometimes just + + align:start position:0% +on their face because sometimes just + + + align:start position:0% +on their face because sometimes just +moving to the left a foot and a half or + + align:start position:0% +moving to the left a foot and a half or + + + align:start position:0% +moving to the left a foot and a half or +to the right a foot and a half will + + align:start position:0% +to the right a foot and a half will + + + align:start position:0% +to the right a foot and a half will +completely change the lighting when + + align:start position:0% +completely change the lighting when + + + align:start position:0% +completely change the lighting when +somebody moves their face like this to + + align:start position:0% +somebody moves their face like this to + + + align:start position:0% +somebody moves their face like this to +look at you or like this to look at you + + align:start position:0% +look at you or like this to look at you + + + align:start position:0% +look at you or like this to look at you +so those are the things that you want to + + align:start position:0% +so those are the things that you want to + + + align:start position:0% +so those are the things that you want to +get get in the habit of like always + + align:start position:0% +get get in the habit of like always + + + align:start position:0% +get get in the habit of like always +thinking about it becomes this automatic + + align:start position:0% +thinking about it becomes this automatic + + + align:start position:0% +thinking about it becomes this automatic +background process sort of like you know + + align:start position:0% +background process sort of like you know + + + align:start position:0% +background process sort of like you know +background rendering or whatever um and + + align:start position:0% +background rendering or whatever um and + + + align:start position:0% +background rendering or whatever um and +and of course I I do like dramatic kiar + + align:start position:0% +and of course I I do like dramatic kiar + + + align:start position:0% +and of course I I do like dramatic kiar +skuro sometimes um this was a particular + + align:start position:0% +skuro sometimes um this was a particular + + + align:start position:0% +skuro sometimes um this was a particular +moment where the character is talking + + align:start position:0% +moment where the character is talking + + + align:start position:0% +moment where the character is talking +about how he first came to Boston and he + + align:start position:0% +about how he first came to Boston and he + + + align:start position:0% +about how he first came to Boston and he +found it to be a cool and uninviting + + align:start position:0% +found it to be a cool and uninviting + + + align:start position:0% +found it to be a cool and uninviting +place and people weren't very friendly + + align:start position:0% +place and people weren't very friendly + + + align:start position:0% +place and people weren't very friendly +um and so even though most of the + + align:start position:0% +um and so even though most of the + + + align:start position:0% +um and so even though most of the +interviews in this film are shot in + + align:start position:0% +interviews in this film are shot in + + + align:start position:0% +interviews in this film are shot in +natural light I decided to to to shoot + + align:start position:0% +natural light I decided to to to shoot + + + align:start position:0% +natural light I decided to to to shoot +this one kind of dramatic and dark this + + align:start position:0% +this one kind of dramatic and dark this + + + align:start position:0% +this one kind of dramatic and dark this +is sort of the the this is where the + + align:start position:0% +is sort of the the this is where the + + + align:start position:0% +is sort of the the this is where the +character starts to realize um certain + + align:start position:0% +character starts to realize um certain + + + align:start position:0% +character starts to realize um certain +things and it's a very sort of kind of + + align:start position:0% +things and it's a very sort of kind of + + + align:start position:0% +things and it's a very sort of kind of +personal intimate moment so we said okay + + align:start position:0% +personal intimate moment so we said okay + + + align:start position:0% +personal intimate moment so we said okay +let's let's kind of light uh do the more + + align:start position:0% +let's let's kind of light uh do the more + + + align:start position:0% +let's let's kind of light uh do the more +Kos skuro thing so you have the the + + align:start position:0% +Kos skuro thing so you have the the + + + align:start position:0% +Kos skuro thing so you have the the +light coming from from the side and + + align:start position:0% +light coming from from the side and + + + align:start position:0% +light coming from from the side and +we're using actually pretty relatively + + align:start position:0% +we're using actually pretty relatively + + + align:start position:0% +we're using actually pretty relatively +intense blue backlights U for the + + align:start position:0% +intense blue backlights U for the + + + align:start position:0% +intense blue backlights U for the +background so that the background + + align:start position:0% +background so that the background + + + align:start position:0% +background so that the background +doesn't go totally black but it's it's + + align:start position:0% +doesn't go totally black but it's it's + + + align:start position:0% +doesn't go totally black but it's it's +relatively dark so this is a little more + + align:start position:0% +relatively dark so this is a little more + + + align:start position:0% +relatively dark so this is a little more +along the lines of carvaggio versus + + align:start position:0% +along the lines of carvaggio versus + + + align:start position:0% +along the lines of carvaggio versus +verir and you can also you can also see + + align:start position:0% +verir and you can also you can also see + + + align:start position:0% +verir and you can also you can also see +kind of the theatricality that you were + + align:start position:0% +kind of the theatricality that you were + + + align:start position:0% +kind of the theatricality that you were +talking about before I mean it might + + align:start position:0% +talking about before I mean it might + + + align:start position:0% +talking about before I mean it might +work for the subject in this case it + + align:start position:0% +work for the subject in this case it + + + align:start position:0% +work for the subject in this case it +worked in this case and it's really the + + align:start position:0% +worked in this case and it's really the + + + align:start position:0% +worked in this case and it's really the +only interview in the entire film that's + + align:start position:0% +only interview in the entire film that's + + + align:start position:0% +only interview in the entire film that's +lit this way this was was kind of a + + align:start position:0% +lit this way this was was kind of a + + + align:start position:0% +lit this way this was was kind of a +brief theatrical moment in some respects + + align:start position:0% +brief theatrical moment in some respects + + + align:start position:0% +brief theatrical moment in some respects +but yeah it has that theatricality it's + + align:start position:0% +but yeah it has that theatricality it's + + + align:start position:0% +but yeah it has that theatricality it's +not at all + + align:start position:0% +not at all + + + align:start position:0% +not at all +natural right this was of somebody + + align:start position:0% +natural right this was of somebody + + + align:start position:0% +natural right this was of somebody +feeling like a fish out of water I + + align:start position:0% +feeling like a fish out of water I + + + align:start position:0% +feeling like a fish out of water I +wanted to create an image that didn't + + align:start position:0% +wanted to create an image that didn't + + + align:start position:0% +wanted to create an image that didn't +feel like it fit with the rest of the + + align:start position:0% +feel like it fit with the rest of the + + + align:start position:0% +feel like it fit with the rest of the +film uh + + align:start position:0% +film uh + + + align:start position:0% +film uh +so so these are four different + + align:start position:0% +so so these are four different + + + align:start position:0% +so so these are four different +approaches um to an interview situation + + align:start position:0% +approaches um to an interview situation + + + align:start position:0% +approaches um to an interview situation +and if you take a look at the PDF uh + + align:start position:0% +and if you take a look at the PDF uh + + + align:start position:0% +and if you take a look at the PDF uh +I've kind of synthesized what I have + + align:start position:0% +I've kind of synthesized what I have + + + align:start position:0% +I've kind of synthesized what I have +found from seven or eight different + + align:start position:0% +found from seven or eight different + + + align:start position:0% +found from seven or eight different +sources um there are + + align:start position:0% +sources um there are + + + align:start position:0% +sources um there are +basically as you change the key + + align:start position:0% +basically as you change the key + + + align:start position:0% +basically as you change the key +light as you change the position of the + + align:start position:0% +light as you change the position of the + + + align:start position:0% +light as you change the position of the +key light relative to the subject you + + align:start position:0% +key light relative to the subject you + + + align:start position:0% +key light relative to the subject you +you change you go from this Continuum + + align:start position:0% +you change you go from this Continuum + + + align:start position:0% +you change you go from this Continuum +from glamour Lighting on the left where + + align:start position:0% +from glamour Lighting on the left where + + + align:start position:0% +from glamour Lighting on the left where +the key light and the fill light are + + align:start position:0% +the key light and the fill light are + + + align:start position:0% +the key light and the fill light are +actually directly overhead there's a + + align:start position:0% +actually directly overhead there's a + + + align:start position:0% +actually directly overhead there's a +small little butterfly Shadow under the + + align:start position:0% +small little butterfly Shadow under the + + + align:start position:0% +small little butterfly Shadow under the +nose and there's a fill light filling + + align:start position:0% +nose and there's a fill light filling + + + align:start position:0% +nose and there's a fill light filling +that in so it's not a harsh Shadow under + + align:start position:0% +that in so it's not a harsh Shadow under + + + align:start position:0% +that in so it's not a harsh Shadow under +the nose and it and this kind of + + align:start position:0% +the nose and it and this kind of + + + align:start position:0% +the nose and it and this kind of +Hollywood lighting where the key is + + align:start position:0% +Hollywood lighting where the key is + + + align:start position:0% +Hollywood lighting where the key is +almost in front of the subject gives you + + align:start position:0% +almost in front of the subject gives you + + + align:start position:0% +almost in front of the subject gives you +this very glamorous look especially if + + align:start position:0% +this very glamorous look especially if + + + align:start position:0% +this very glamorous look especially if +you have high + + align:start position:0% +you have high + + + align:start position:0% +you have high +cheekbones uh but it's not at all + + align:start position:0% +cheekbones uh but it's not at all + + + align:start position:0% +cheekbones uh but it's not at all +natural but it is very glamorous um and + + align:start position:0% +natural but it is very glamorous um and + + + align:start position:0% +natural but it is very glamorous um and +then as you move the fill light to the + + align:start position:0% +then as you move the fill light to the + + + align:start position:0% +then as you move the fill light to the +left in the middle here you get to the + + align:start position:0% +left in the middle here you get to the + + + align:start position:0% +left in the middle here you get to the +rembrand style which is kind of my + + align:start position:0% +rembrand style which is kind of my + + + align:start position:0% +rembrand style which is kind of my +tendency I like the light coming from + + align:start position:0% +tendency I like the light coming from + + + align:start position:0% +tendency I like the light coming from +the left I also find in situations where + + align:start position:0% +the left I also find in situations where + + + align:start position:0% +the left I also find in situations where +I'm like using a small handheld LED + + align:start position:0% +I'm like using a small handheld LED + + + align:start position:0% +I'm like using a small handheld LED +light to give a little bit of + + align:start position:0% +light to give a little bit of + + + align:start position:0% +light to give a little bit of +supplemental Lighting in a otherwise + + align:start position:0% +supplemental Lighting in a otherwise + + + align:start position:0% +supplemental Lighting in a otherwise +verit situation if I put light to the + + align:start position:0% +verit situation if I put light to the + + + align:start position:0% +verit situation if I put light to the +left of the subject not only do they + + align:start position:0% +left of the subject not only do they + + + align:start position:0% +left of the subject not only do they +look better and more dimensional but + + align:start position:0% +look better and more dimensional but + + + align:start position:0% +look better and more dimensional but +it's not glaring in their eye and that's + + align:start position:0% +it's not glaring in their eye and that's + + + align:start position:0% +it's not glaring in their eye and that's +actually more + + align:start position:0% +actually more + + + align:start position:0% +actually more +comfortable and then of course profile + + align:start position:0% +comfortable and then of course profile + + + align:start position:0% +comfortable and then of course profile +lighting where you basically the key is + + align:start position:0% +lighting where you basically the key is + + + align:start position:0% +lighting where you basically the key is +is behind the + + align:start position:0% +is behind the + + + align:start position:0% +is behind the +subject and you're emphasizing their + + align:start position:0% +subject and you're emphasizing their + + + align:start position:0% +subject and you're emphasizing their +profile I mean that's really dramatic + + align:start position:0% +profile I mean that's really dramatic + + + align:start position:0% +profile I mean that's really dramatic +you would do that for sort of you know + + align:start position:0% +you would do that for sort of you know + + + align:start position:0% +you would do that for sort of you know +interview with somebody whose identity + + align:start position:0% +interview with somebody whose identity + + + align:start position:0% +interview with somebody whose identity +you want to obscure you kill the you + + align:start position:0% +you want to obscure you kill the you + + + align:start position:0% +you want to obscure you kill the you +kill the fillite + + align:start position:0% +kill the fillite + + + align:start position:0% +kill the fillite +and you have a backlight coming from the + + align:start position:0% +and you have a backlight coming from the + + + align:start position:0% +and you have a backlight coming from the +back and you just see this outline rim + + align:start position:0% +back and you just see this outline rim + + + align:start position:0% +back and you just see this outline rim +of a person so as you you know what this + + align:start position:0% +of a person so as you you know what this + + + align:start position:0% +of a person so as you you know what this +slide is about is to encourage you when + + align:start position:0% +slide is about is to encourage you when + + + align:start position:0% +slide is about is to encourage you when +I've like taught a detailed + + align:start position:0% +I've like taught a detailed + + + align:start position:0% +I've like taught a detailed +cinematography class I actually have the + + align:start position:0% +cinematography class I actually have the + + + align:start position:0% +cinematography class I actually have the +students set all of these up and shoot + + align:start position:0% +students set all of these up and shoot + + + align:start position:0% +students set all of these up and shoot +all these different setups and reflect + + align:start position:0% +all these different setups and reflect + + + align:start position:0% +all these different setups and reflect +on how the how the lighting changes as + + align:start position:0% +on how the how the lighting changes as + + + align:start position:0% +on how the how the lighting changes as +you move the key light around you know + + align:start position:0% +you move the key light around you know + + + align:start position:0% +you move the key light around you know +it' be cool to have like a 3D simulator + + align:start position:0% +it' be cool to have like a 3D simulator + + + align:start position:0% +it' be cool to have like a 3D simulator +environment to kind of try these things + + align:start position:0% +environment to kind of try these things + + + align:start position:0% +environment to kind of try these things +out but there's nothing like going out + + align:start position:0% +out but there's nothing like going out + + + align:start position:0% +out but there's nothing like going out +into the real world with your lighting + + align:start position:0% +into the real world with your lighting + + + align:start position:0% +into the real world with your lighting +kit um and trying these different setups + + align:start position:0% +kit um and trying these different setups + + + align:start position:0% +kit um and trying these different setups +so um we've talked about soft light + + align:start position:0% +so um we've talked about soft light + + + align:start position:0% +so um we've talked about soft light +we've talked about hard lights some + + align:start position:0% +we've talked about hard lights some + + + align:start position:0% +we've talked about hard lights some +common lights that you find available in + + align:start position:0% +common lights that you find available in + + + align:start position:0% +common lights that you find available in +the market today um there's a variety of + + align:start position:0% +the market today um there's a variety of + + + align:start position:0% +the market today um there's a variety of +soft lights they're very popular since + + align:start position:0% +soft lights they're very popular since + + + align:start position:0% +soft lights they're very popular since +if you're going to have if you're going + + align:start position:0% +if you're going to have if you're going + + + align:start position:0% +if you're going to have if you're going +to do a simple quick and dirty interview + + align:start position:0% +to do a simple quick and dirty interview + + + align:start position:0% +to do a simple quick and dirty interview +with a single light typically you'll + + align:start position:0% +with a single light typically you'll + + + align:start position:0% +with a single light typically you'll +just pull out a soft light um a popular + + align:start position:0% +just pull out a soft light um a popular + + + align:start position:0% +just pull out a soft light um a popular +soft light is something called the low + + align:start position:0% +soft light is something called the low + + + align:start position:0% +soft light is something called the low +Rea it kind of Pops open like an + + align:start position:0% +Rea it kind of Pops open like an + + + align:start position:0% +Rea it kind of Pops open like an +umbrella you throw a diffus user on the + + align:start position:0% +umbrella you throw a diffus user on the + + + align:start position:0% +umbrella you throw a diffus user on the +front you hook it up to the stand and it + + align:start position:0% +front you hook it up to the stand and it + + + align:start position:0% +front you hook it up to the stand and it +sets up very quickly and instant soft + + align:start position:0% +sets up very quickly and instant soft + + + align:start position:0% +sets up very quickly and instant soft +light um I prefer although they're a + + align:start position:0% +light um I prefer although they're a + + + align:start position:0% +light um I prefer although they're a +little more expensive I love the kinof + + align:start position:0% +little more expensive I love the kinof + + + align:start position:0% +little more expensive I love the kinof +flow Diva light this is a a fluorescent + + align:start position:0% +flow Diva light this is a a fluorescent + + + align:start position:0% +flow Diva light this is a a fluorescent +lights light fixture that has four or + + align:start position:0% +lights light fixture that has four or + + + align:start position:0% +lights light fixture that has four or +two depending on the size fluorescent + + align:start position:0% +two depending on the size fluorescent + + + align:start position:0% +two depending on the size fluorescent +bulbs and you can pop in either daylight + + align:start position:0% +bulbs and you can pop in either daylight + + + align:start position:0% +bulbs and you can pop in either daylight +balance fluorescent or tungsten balance + + align:start position:0% +balance fluorescent or tungsten balance + + + align:start position:0% +balance fluorescent or tungsten balance +fluoresence I've done a lot of + + align:start position:0% +fluoresence I've done a lot of + + + align:start position:0% +fluoresence I've done a lot of +interviews Outdoors under a tree in the + + align:start position:0% +interviews Outdoors under a tree in the + + + align:start position:0% +interviews Outdoors under a tree in the +shade and brought in the diva with the + + align:start position:0% +shade and brought in the diva with the + + + align:start position:0% +shade and brought in the diva with the +daylight balance light just for a little + + align:start position:0% +daylight balance light just for a little + + + align:start position:0% +daylight balance light just for a little +bit of Sparkle in the eyes just for a + + align:start position:0% +bit of Sparkle in the eyes just for a + + + align:start position:0% +bit of Sparkle in the eyes just for a +little bit of extra definition and all + + align:start position:0% +little bit of extra definition and all + + + align:start position:0% +little bit of extra definition and all +of a sudden it takes something in the + + align:start position:0% +of a sudden it takes something in the + + + align:start position:0% +of a sudden it takes something in the +shade and soft and gives it just a + + align:start position:0% +shade and soft and gives it just a + + + align:start position:0% +shade and soft and gives it just a +little bit of dimensionality and you + + align:start position:0% +little bit of dimensionality and you + + + align:start position:0% +little bit of dimensionality and you +can't do that unless your light source + + align:start position:0% +can't do that unless your light source + + + align:start position:0% +can't do that unless your light source +is daylight balanced and the diva is + + align:start position:0% +is daylight balanced and the diva is + + + align:start position:0% +is daylight balanced and the diva is +just barely bright enough to use in the + + align:start position:0% +just barely bright enough to use in the + + + align:start position:0% +just barely bright enough to use in the +shade no light source is going to work + + align:start position:0% +shade no light source is going to work + + + align:start position:0% +shade no light source is going to work +in the sun unless you have a Hollywood + + align:start position:0% +in the sun unless you have a Hollywood + + + align:start position:0% +in the sun unless you have a Hollywood +grip truck um but for indoor interviews + + align:start position:0% +grip truck um but for indoor interviews + + + align:start position:0% +grip truck um but for indoor interviews +the diva a couple of Divas is just + + align:start position:0% +the diva a couple of Divas is just + + + align:start position:0% +the diva a couple of Divas is just +spectacular in terms of soft light with + + align:start position:0% +spectacular in terms of soft light with + + + align:start position:0% +spectacular in terms of soft light with +just a little bit of + + align:start position:0% +just a little bit of + + + align:start position:0% +just a little bit of +directionality um and the fact that you + + align:start position:0% +directionality um and the fact that you + + + align:start position:0% +directionality um and the fact that you +can pop in and out the fluorescent light + + align:start position:0% +can pop in and out the fluorescent light + + + align:start position:0% +can pop in and out the fluorescent light +tubes for either daylight or tungsten is + + align:start position:0% +tubes for either daylight or tungsten is + + + align:start position:0% +tubes for either daylight or tungsten is +really awesome it comes in a little + + align:start position:0% +really awesome it comes in a little + + + align:start position:0% +really awesome it comes in a little +suitcase with both sets of bulbs um and + + align:start position:0% +suitcase with both sets of bulbs um and + + + align:start position:0% +suitcase with both sets of bulbs um and +off you go uh open face lights are much + + align:start position:0% +off you go uh open face lights are much + + + align:start position:0% +off you go uh open face lights are much +less expensive they're they're they're + + align:start position:0% +less expensive they're they're they're + + + align:start position:0% +less expensive they're they're they're +relatively cheap anything from a $30 + + align:start position:0% +relatively cheap anything from a $30 + + + align:start position:0% +relatively cheap anything from a $30 +work light at Home Depot to a loyal a + + align:start position:0% +work light at Home Depot to a loyal a + + + align:start position:0% +work light at Home Depot to a loyal a +low omn light they come in all sorts of + + align:start position:0% +low omn light they come in all sorts of + + + align:start position:0% +low omn light they come in all sorts of +shapes and sizes typically they have a + + align:start position:0% +shapes and sizes typically they have a + + + align:start position:0% +shapes and sizes typically they have a +parabolic + + align:start position:0% +parabolic + + + align:start position:0% +parabolic +reflector and then we'll talk in a + + align:start position:0% +reflector and then we'll talk in a + + + align:start position:0% +reflector and then we'll talk in a +moment about Fels Fels are a little + + align:start position:0% +moment about Fels Fels are a little + + + align:start position:0% +moment about Fels Fels are a little +fancier they actually have a lens + + align:start position:0% +fancier they actually have a lens + + + align:start position:0% +fancier they actually have a lens +system uh pars and of course what you + + align:start position:0% +system uh pars and of course what you + + + align:start position:0% +system uh pars and of course what you +see here in the picture is a par with a + + align:start position:0% +see here in the picture is a par with a + + + align:start position:0% +see here in the picture is a par with a +soft box on top of it pars are very + + align:start position:0% +soft box on top of it pars are very + + + align:start position:0% +soft box on top of it pars are very +efficient light sources because they + + align:start position:0% +efficient light sources because they + + + align:start position:0% +efficient light sources because they +have this parabolic reflector built into + + align:start position:0% +have this parabolic reflector built into + + + align:start position:0% +have this parabolic reflector built into +the light unit um and they're often + + align:start position:0% +the light unit um and they're often + + + align:start position:0% +the light unit um and they're often +available in this high technology + + align:start position:0% +available in this high technology + + + align:start position:0% +available in this high technology +daylight balanced light called an HMI um + + align:start position:0% +daylight balanced light called an HMI um + + + align:start position:0% +daylight balanced light called an HMI um +small Pars in the 300 watt range are + + align:start position:0% +small Pars in the 300 watt range are + + + align:start position:0% +small Pars in the 300 watt range are +very popular am with documentary Crews + + align:start position:0% +very popular am with documentary Crews + + + align:start position:0% +very popular am with documentary Crews +because you can power them off a small + + align:start position:0% +because you can power them off a small + + + align:start position:0% +because you can power them off a small +battery um they're daylight balance so + + align:start position:0% +battery um they're daylight balance so + + + align:start position:0% +battery um they're daylight balance so +you can use them Outdoors to get rid of + + align:start position:0% +you can use them Outdoors to get rid of + + + align:start position:0% +you can use them Outdoors to get rid of +Shadows and stuff like that uh and then + + align:start position:0% +Shadows and stuff like that uh and then + + + align:start position:0% +Shadows and stuff like that uh and then +if you need to soften them you can + + align:start position:0% +if you need to soften them you can + + + align:start position:0% +if you need to soften them you can +always pop a soft box in the front or if + + align:start position:0% +always pop a soft box in the front or if + + + align:start position:0% +always pop a soft box in the front or if +you need that hard intensity efficiency + + align:start position:0% +you need that hard intensity efficiency + + + align:start position:0% +you need that hard intensity efficiency +of the par unit you can just pull the + + align:start position:0% +of the par unit you can just pull the + + + align:start position:0% +of the par unit you can just pull the +soft box off so they're very versatile + + align:start position:0% +soft box off so they're very versatile + + + align:start position:0% +soft box off so they're very versatile +in that respect and in fact here in + + align:start position:0% +in that respect and in fact here in + + + align:start position:0% +in that respect and in fact here in +Boston um + + align:start position:0% +Boston um + + + align:start position:0% +Boston um +the local rental house rents something + + align:start position:0% +the local rental house rents something + + + align:start position:0% +the local rental house rents something +called the cobal did I say that right + + align:start position:0% +called the cobal did I say that right + + + align:start position:0% +called the cobal did I say that right +cobal um small HMI par uh which is + + align:start position:0% +cobal um small HMI par uh which is + + + align:start position:0% +cobal um small HMI par uh which is +really useful + + align:start position:0% +really useful + + + align:start position:0% +really useful +um but if you're on a tight budget you + + align:start position:0% +um but if you're on a tight budget you + + + align:start position:0% +um but if you're on a tight budget you +don't necessarily have to go out and + + align:start position:0% +don't necessarily have to go out and + + + align:start position:0% +don't necessarily have to go out and +spend thousands of dollars on + + align:start position:0% +spend thousands of dollars on + + + align:start position:0% +spend thousands of dollars on +professional lighting Mother Nature + + align:start position:0% +professional lighting Mother Nature + + + align:start position:0% +professional lighting Mother Nature +usually provides her services for free + + align:start position:0% +usually provides her services for free + + + align:start position:0% +usually provides her services for free +you can use practical household bulbs uh + + align:start position:0% +you can use practical household bulbs uh + + + align:start position:0% +you can use practical household bulbs uh +popular among um some folks or S you + + align:start position:0% +popular among um some folks or S you + + + align:start position:0% +popular among um some folks or S you +know simple photo flood lamps which are + + align:start position:0% +know simple photo flood lamps which are + + + align:start position:0% +know simple photo flood lamps which are +very bright incandescent lamps that you + + align:start position:0% +very bright incandescent lamps that you + + + align:start position:0% +very bright incandescent lamps that you +can put in inexpensive fixtures it turns + + align:start position:0% +can put in inexpensive fixtures it turns + + + align:start position:0% +can put in inexpensive fixtures it turns +out fluorescent utility lights ordinary + + align:start position:0% +out fluorescent utility lights ordinary + + + align:start position:0% +out fluorescent utility lights ordinary +fluorescent lights you can actually go + + align:start position:0% +fluorescent lights you can actually go + + + align:start position:0% +fluorescent lights you can actually go +to your local hardware supply store and + + align:start position:0% +to your local hardware supply store and + + + align:start position:0% +to your local hardware supply store and +buy daylight balanced or um tungsten + + align:start position:0% +buy daylight balanced or um tungsten + + + align:start position:0% +buy daylight balanced or um tungsten +balanced uh fluorescent uh tubes chroma + + align:start position:0% +balanced uh fluorescent uh tubes chroma + + + align:start position:0% +balanced uh fluorescent uh tubes chroma +50s and Ultra 32s I think they're called + + align:start position:0% +50s and Ultra 32s I think they're called + + + align:start position:0% +50s and Ultra 32s I think they're called +um and you can put them in ordinary + + align:start position:0% +um and you can put them in ordinary + + + align:start position:0% +um and you can put them in ordinary +florescent fixtures uh Chinese lanterns + + align:start position:0% +florescent fixtures uh Chinese lanterns + + + align:start position:0% +florescent fixtures uh Chinese lanterns +are awesome these paper little lanterns + + align:start position:0% +are awesome these paper little lanterns + + + align:start position:0% +are awesome these paper little lanterns +but I wouldn't use more than a 60 or + + align:start position:0% +but I wouldn't use more than a 60 or + + + align:start position:0% +but I wouldn't use more than a 60 or +pushing it 100 watt bulb in these paper + + align:start position:0% +pushing it 100 watt bulb in these paper + + + align:start position:0% +pushing it 100 watt bulb in these paper +lanterns and never leave them unattended + + align:start position:0% +lanterns and never leave them unattended + + + align:start position:0% +lanterns and never leave them unattended +um regardless of how flame retardant the + + align:start position:0% +um regardless of how flame retardant the + + + align:start position:0% +um regardless of how flame retardant the +manufacturers say they are I wouldn't + + align:start position:0% +manufacturers say they are I wouldn't + + + align:start position:0% +manufacturers say they are I wouldn't +leave them alone um but they give you + + align:start position:0% +leave them alone um but they give you + + + align:start position:0% +leave them alone um but they give you +this beautiful soft light now there's a + + align:start position:0% +this beautiful soft light now there's a + + + align:start position:0% +this beautiful soft light now there's a +professional version of these lanterns + + align:start position:0% +professional version of these lanterns + + + align:start position:0% +professional version of these lanterns +called Chima lanterns and they're made + + align:start position:0% +called Chima lanterns and they're made + + + align:start position:0% +called Chima lanterns and they're made +of a you know special high heat + + align:start position:0% +of a you know special high heat + + + align:start position:0% +of a you know special high heat +resistant material and you can put a + + align:start position:0% +resistant material and you can put a + + + align:start position:0% +resistant material and you can put a +pretty powerful thousand watt lamp + + align:start position:0% +pretty powerful thousand watt lamp + + + align:start position:0% +pretty powerful thousand watt lamp +inside one of those and get this + + align:start position:0% +inside one of those and get this + + + align:start position:0% +inside one of those and get this +beautiful beautiful soft light um but + + align:start position:0% +beautiful beautiful soft light um but + + + align:start position:0% +beautiful beautiful soft light um but +I've seen a lot of people get a lot of + + align:start position:0% +I've seen a lot of people get a lot of + + + align:start position:0% +I've seen a lot of people get a lot of +mileage out of ordinary um work lights I + + align:start position:0% +mileage out of ordinary um work lights I + + + align:start position:0% +mileage out of ordinary um work lights I +know a lot of Animation folks use + + align:start position:0% +know a lot of Animation folks use + + + align:start position:0% +know a lot of Animation folks use +ordinary hardware store work lights for + + align:start position:0% +ordinary hardware store work lights for + + + align:start position:0% +ordinary hardware store work lights for +their lighting Source you can clip a + + align:start position:0% +their lighting Source you can clip a + + + align:start position:0% +their lighting Source you can clip a +little diffusion in the front if you + + align:start position:0% +little diffusion in the front if you + + + align:start position:0% +little diffusion in the front if you +need to they're cheap the only downside + + align:start position:0% +need to they're cheap the only downside + + + align:start position:0% +need to they're cheap the only downside +is that they don't fold up nicely for + + align:start position:0% +is that they don't fold up nicely for + + + align:start position:0% +is that they don't fold up nicely for +for travel um but if you're doing like + + align:start position:0% +for travel um but if you're doing like + + + align:start position:0% +for travel um but if you're doing like +animation work at home uh those + + align:start position:0% +animation work at home uh those + + + align:start position:0% +animation work at home uh those +inexpensive work lights uh work great + + align:start position:0% +inexpensive work lights uh work great + + + align:start position:0% +inexpensive work lights uh work great +and you can actually buy you know Tong + + align:start position:0% +and you can actually buy you know Tong + + + align:start position:0% +and you can actually buy you know Tong +inbalance 3200 de Kelvin bulbs for them + + align:start position:0% +inbalance 3200 de Kelvin bulbs for them + + + align:start position:0% +inbalance 3200 de Kelvin bulbs for them +so uh on camera lights some people like + + align:start position:0% +so uh on camera lights some people like + + + align:start position:0% +so uh on camera lights some people like +them I personally don't like on camera + + align:start position:0% +them I personally don't like on camera + + + align:start position:0% +them I personally don't like on camera +lights um because I really don't like + + align:start position:0% +lights um because I really don't like + + + align:start position:0% +lights um because I really don't like +the flat look that they create um I + + align:start position:0% +the flat look that they create um I + + + align:start position:0% +the flat look that they create um I +prefer to hold a camera off to the side + + align:start position:0% +prefer to hold a camera off to the side + + + align:start position:0% +prefer to hold a camera off to the side +find an assistant find somebody um to + + align:start position:0% +find an assistant find somebody um to + + + align:start position:0% +find an assistant find somebody um to +kind of hold the light off to the side + + align:start position:0% +kind of hold the light off to the side + + + align:start position:0% +kind of hold the light off to the side +I've even done it myself it you your arm + + align:start position:0% +I've even done it myself it you your arm + + + align:start position:0% +I've even done it myself it you your arm +gets really really really tired but um + + align:start position:0% +gets really really really tired but um + + + align:start position:0% +gets really really really tired but um +it pays off by not having that deer Cott + + align:start position:0% +it pays off by not having that deer Cott + + + align:start position:0% +it pays off by not having that deer Cott +in the headlights look of the light + + align:start position:0% +in the headlights look of the light + + + align:start position:0% +in the headlights look of the light +directly on the camera people don't like + + align:start position:0% +directly on the camera people don't like + + + align:start position:0% +directly on the camera people don't like +being + + align:start position:0% +being + + + align:start position:0% +being +blinded get the light off to the side is + + align:start position:0% +blinded get the light off to the side is + + + align:start position:0% +blinded get the light off to the side is +the moral of the story but these small + + align:start position:0% +the moral of the story but these small + + + align:start position:0% +the moral of the story but these small +battery powered lights especially the + + align:start position:0% +battery powered lights especially the + + + align:start position:0% +battery powered lights especially the +new generation of light emitting diode + + align:start position:0% +new generation of light emitting diode + + + align:start position:0% +new generation of light emitting diode +LED lights are spectacular because I've + + align:start position:0% +LED lights are spectacular because I've + + + align:start position:0% +LED lights are spectacular because I've +been able to like shoot all day with + + align:start position:0% +been able to like shoot all day with + + + align:start position:0% +been able to like shoot all day with +like four camera batteries and a couple + + align:start position:0% +like four camera batteries and a couple + + + align:start position:0% +like four camera batteries and a couple +of LED lights uh not on continuously but + + align:start position:0% +of LED lights uh not on continuously but + + + align:start position:0% +of LED lights uh not on continuously but +it can work um I have a thing for frels + + align:start position:0% +it can work um I have a thing for frels + + + align:start position:0% +it can work um I have a thing for frels +I really like the quality of their light + + align:start position:0% +I really like the quality of their light + + + align:start position:0% +I really like the quality of their light +um they were originally developed by + + align:start position:0% +um they were originally developed by + + + align:start position:0% +um they were originally developed by +Austine Fel who contributed to the + + align:start position:0% +Austine Fel who contributed to the + + + align:start position:0% +Austine Fel who contributed to the +theory of color and Optics and the + + align:start position:0% +theory of color and Optics and the + + + align:start position:0% +theory of color and Optics and the +French Lighthouse commission had a + + align:start position:0% +French Lighthouse commission had a + + + align:start position:0% +French Lighthouse commission had a +problem you know in the early 1800s + + align:start position:0% +problem you know in the early 1800s + + + align:start position:0% +problem you know in the early 1800s +those whale oil lamps weren't very + + align:start position:0% +those whale oil lamps weren't very + + + align:start position:0% +those whale oil lamps weren't very +bright ships are going into rocks a lot + + align:start position:0% +bright ships are going into rocks a lot + + + align:start position:0% +bright ships are going into rocks a lot +of sailors and merchandise was being + + align:start position:0% +of sailors and merchandise was being + + + align:start position:0% +of sailors and merchandise was being +lost at sea um and they commissioned Fel + + align:start position:0% +lost at sea um and they commissioned Fel + + + align:start position:0% +lost at sea um and they commissioned Fel +to solve the lighthouse problem well he + + align:start position:0% +to solve the lighthouse problem well he + + + align:start position:0% +to solve the lighthouse problem well he +realized you know what if we put a whole + + align:start position:0% +realized you know what if we put a whole + + + align:start position:0% +realized you know what if we put a whole +bunch of these triangular pieces of + + align:start position:0% +bunch of these triangular pieces of + + + align:start position:0% +bunch of these triangular pieces of +glass + + align:start position:0% +glass + + + align:start position:0% +glass +in the right arrangement we can take all + + align:start position:0% +in the right arrangement we can take all + + + align:start position:0% +in the right arrangement we can take all +of those light rays that are going + + align:start position:0% +of those light rays that are going + + + align:start position:0% +of those light rays that are going +astray and send them all off single line + + align:start position:0% +astray and send them all off single line + + + align:start position:0% +astray and send them all off single line +out to see and all of a sudden these + + align:start position:0% +out to see and all of a sudden these + + + align:start position:0% +out to see and all of a sudden these +teeny tiny little whale oil powered um + + align:start position:0% +teeny tiny little whale oil powered um + + + align:start position:0% +teeny tiny little whale oil powered um +lamps were super bright CU all of the + + align:start position:0% +lamps were super bright CU all of the + + + align:start position:0% +lamps were super bright CU all of the +light rays are going single file where + + align:start position:0% +light rays are going single file where + + + align:start position:0% +light rays are going single file where +they're supposed to be out to seea + + align:start position:0% +they're supposed to be out to seea + + + align:start position:0% +they're supposed to be out to seea +instead of you know lighting the side of + + align:start position:0% +instead of you know lighting the side of + + + align:start position:0% +instead of you know lighting the side of +the lighthouse who cares about that + + align:start position:0% +the lighthouse who cares about that + + + align:start position:0% +the lighthouse who cares about that +right so what's interesting about Fels + + align:start position:0% +right so what's interesting about Fels + + + align:start position:0% +right so what's interesting about Fels +is that they're very crisp clean Focus + + align:start position:0% +is that they're very crisp clean Focus + + + align:start position:0% +is that they're very crisp clean Focus +lights that cast perfectly clean Shadows + + align:start position:0% +lights that cast perfectly clean Shadows + + + align:start position:0% +lights that cast perfectly clean Shadows +they have the same quality of light as + + align:start position:0% +they have the same quality of light as + + + align:start position:0% +they have the same quality of light as +direct sunlight they're great for back + + align:start position:0% +direct sunlight they're great for back + + + align:start position:0% +direct sunlight they're great for back +lights they're great for when you want + + align:start position:0% +lights they're great for when you want + + + align:start position:0% +lights they're great for when you want +that sort of quality of light coming + + align:start position:0% +that sort of quality of light coming + + + align:start position:0% +that sort of quality of light coming +through window they're a little heavier + + align:start position:0% +through window they're a little heavier + + + align:start position:0% +through window they're a little heavier +and more expensive because they have + + align:start position:0% +and more expensive because they have + + + align:start position:0% +and more expensive because they have +this scalloped Glass lens which you + + align:start position:0% +this scalloped Glass lens which you + + + align:start position:0% +this scalloped Glass lens which you +might recognize the pattern from + + align:start position:0% +might recognize the pattern from + + + align:start position:0% +might recognize the pattern from +lighthouses which we have a lot of here + + align:start position:0% +lighthouses which we have a lot of here + + + align:start position:0% +lighthouses which we have a lot of here +in New England um and so the units are a + + align:start position:0% +in New England um and so the units are a + + + align:start position:0% +in New England um and so the units are a +little heavier but they have a little + + align:start position:0% +little heavier but they have a little + + + align:start position:0% +little heavier but they have a little +knob where you can focus them and uh + + align:start position:0% +knob where you can focus them and uh + + + align:start position:0% +knob where you can focus them and uh +they have that nice crisp quality of + + align:start position:0% +they have that nice crisp quality of + + + align:start position:0% +they have that nice crisp quality of +light so I have a thing for frels I + + align:start position:0% +light so I have a thing for frels I + + + align:start position:0% +light so I have a thing for frels I +really like them I own five myself um + + align:start position:0% +really like them I own five myself um + + + align:start position:0% +really like them I own five myself um +but they are heavy to carry around + + align:start position:0% +but they are heavy to carry around + + + align:start position:0% +but they are heavy to carry around +that's the price you pay they they are + + align:start position:0% +that's the price you pay they they are + + + align:start position:0% +that's the price you pay they they are +physically bigger and physically heavier + + align:start position:0% +physically bigger and physically heavier + + + align:start position:0% +physically bigger and physically heavier +um here's a chart sort of comparing + + align:start position:0% +um here's a chart sort of comparing + + + align:start position:0% +um here's a chart sort of comparing +different lighting technologies because + + align:start position:0% +different lighting technologies because + + + align:start position:0% +different lighting technologies because +not only do we have different + + align:start position:0% +not only do we have different + + + align:start position:0% +not only do we have different +configuration of Lights like openface + + align:start position:0% +configuration of Lights like openface + + + align:start position:0% +configuration of Lights like openface +soft light soft + + align:start position:0% +soft light soft + + + align:start position:0% +soft light soft +um open face Fel soft light Etc in terms + + align:start position:0% +um open face Fel soft light Etc in terms + + + align:start position:0% +um open face Fel soft light Etc in terms +of the physical configuration of the + + align:start position:0% +of the physical configuration of the + + + align:start position:0% +of the physical configuration of the +light source versus you know the lens + + align:start position:0% +light source versus you know the lens + + + align:start position:0% +light source versus you know the lens +unit and things like that but there's + + align:start position:0% +unit and things like that but there's + + + align:start position:0% +unit and things like that but there's +basically four technologies that we use + + align:start position:0% +basically four technologies that we use + + + align:start position:0% +basically four technologies that we use +today in professional lighting uh for + + align:start position:0% +today in professional lighting uh for + + + align:start position:0% +today in professional lighting uh for +providing the source of light typical + + align:start position:0% +providing the source of light typical + + + align:start position:0% +providing the source of light typical +tungston incandescent lamps are the + + align:start position:0% +tungston incandescent lamps are the + + + align:start position:0% +tungston incandescent lamps are the +least expensive but they use up a lot of + + align:start position:0% +least expensive but they use up a lot of + + + align:start position:0% +least expensive but they use up a lot of +energy unfortunately incandescent lights + + align:start position:0% +energy unfortunately incandescent lights + + + align:start position:0% +energy unfortunately incandescent lights +they're actually space heaters that + + align:start position:0% +they're actually space heaters that + + + align:start position:0% +they're actually space heaters that +happen to give a small percentage of + + align:start position:0% +happen to give a small percentage of + + + align:start position:0% +happen to give a small percentage of +their energy out in the light range but + + align:start position:0% +their energy out in the light range but + + + align:start position:0% +their energy out in the light range but +they're you know maybe 30% is light and + + align:start position:0% +they're you know maybe 30% is light and + + + align:start position:0% +they're you know maybe 30% is light and +the rest of the energy is is is heat + + align:start position:0% +the rest of the energy is is is heat + + + align:start position:0% +the rest of the energy is is is heat +they're very hot and on a hot summer day + + align:start position:0% +they're very hot and on a hot summer day + + + align:start position:0% +they're very hot and on a hot summer day +they're just really uncomfortable to be + + align:start position:0% +they're just really uncomfortable to be + + + align:start position:0% +they're just really uncomfortable to be +close to hmis is newer technology + + align:start position:0% +close to hmis is newer technology + + + align:start position:0% +close to hmis is newer technology +daylight balanced very high tech um + + align:start position:0% +daylight balanced very high tech um + + + align:start position:0% +daylight balanced very high tech um +units but they're expensive they require + + align:start position:0% +units but they're expensive they require + + + align:start position:0% +units but they're expensive they require +a lot of electronics they require very + + align:start position:0% +a lot of electronics they require very + + + align:start position:0% +a lot of electronics they require very +sophisticated lamps with rare earth + + align:start position:0% +sophisticated lamps with rare earth + + + align:start position:0% +sophisticated lamps with rare earth +gases and all kinds of fancy stuff uh + + align:start position:0% +gases and all kinds of fancy stuff uh + + + align:start position:0% +gases and all kinds of fancy stuff uh +but they're daylight balanced and + + align:start position:0% +but they're daylight balanced and + + + align:start position:0% +but they're daylight balanced and +they're very bright and very efficient + + align:start position:0% +they're very bright and very efficient + + + align:start position:0% +they're very bright and very efficient +um kind of halfway in between are + + align:start position:0% +um kind of halfway in between are + + + align:start position:0% +um kind of halfway in between are +fluorescents um they make great soft + + align:start position:0% +fluorescents um they make great soft + + + align:start position:0% +fluorescents um they make great soft +lights um they're they run very cool um + + align:start position:0% +lights um they're they run very cool um + + + align:start position:0% +lights um they're they run very cool um +they're not necessarily the best thing + + align:start position:0% +they're not necessarily the best thing + + + align:start position:0% +they're not necessarily the best thing +for the environment but neither are the + + align:start position:0% +for the environment but neither are the + + + align:start position:0% +for the environment but neither are the +other lighting sources uh but they run + + align:start position:0% +other lighting sources uh but they run + + + align:start position:0% +other lighting sources uh but they run +cool and they use less power and the + + align:start position:0% +cool and they use less power and the + + + align:start position:0% +cool and they use less power and the +kinof flow fluorescent lights are just + + align:start position:0% +kinof flow fluorescent lights are just + + + align:start position:0% +kinof flow fluorescent lights are just +awesome and up and coming are LEDs LEDs + + align:start position:0% +awesome and up and coming are LEDs LEDs + + + align:start position:0% +awesome and up and coming are LEDs LEDs +have uh have come a long way in the last + + align:start position:0% +have uh have come a long way in the last + + + align:start position:0% +have uh have come a long way in the last +few years they're available in these + + align:start position:0% +few years they're available in these + + + align:start position:0% +few years they're available in these +like panels of either daylight balanced + + align:start position:0% +like panels of either daylight balanced + + + align:start position:0% +like panels of either daylight balanced +or tungsten balanced uh in fact light + + align:start position:0% +or tungsten balanced uh in fact light + + + align:start position:0% +or tungsten balanced uh in fact light +panels has a really nice grid that's a + + align:start position:0% +panels has a really nice grid that's a + + + align:start position:0% +panels has a really nice grid that's a +by color panel it's a grid of both + + align:start position:0% +by color panel it's a grid of both + + + align:start position:0% +by color panel it's a grid of both +daylight and tungsten balanced uh LEDs + + align:start position:0% +daylight and tungsten balanced uh LEDs + + + align:start position:0% +daylight and tungsten balanced uh LEDs +and you can dial in how much you want of + + align:start position:0% +and you can dial in how much you want of + + + align:start position:0% +and you can dial in how much you want of +each there's also a small version uh + + align:start position:0% +each there's also a small version uh + + + align:start position:0% +each there's also a small version uh +called the blender which actually has a + + align:start position:0% +called the blender which actually has a + + + align:start position:0% +called the blender which actually has a +grid of LED of of daylight and tungsten + + align:start position:0% +grid of LED of of daylight and tungsten + + + align:start position:0% +grid of LED of of daylight and tungsten +balanced LEDs and you can dial in the + + align:start position:0% +balanced LEDs and you can dial in the + + + align:start position:0% +balanced LEDs and you can dial in the +color temperature you want so they're + + align:start position:0% +color temperature you want so they're + + + align:start position:0% +color temperature you want so they're +very expensive compared to other light + + align:start position:0% +very expensive compared to other light + + + align:start position:0% +very expensive compared to other light +sources but they're very versatile the + + align:start position:0% +sources but they're very versatile the + + + align:start position:0% +sources but they're very versatile the +zylight is a model of LED light that you + + align:start position:0% +zylight is a model of LED light that you + + + align:start position:0% +zylight is a model of LED light that you +can dial in any color because it uses a + + align:start position:0% +can dial in any color because it uses a + + + align:start position:0% +can dial in any color because it uses a +red green blue grid of LEDs there's some + + align:start position:0% +red green blue grid of LEDs there's some + + + align:start position:0% +red green blue grid of LEDs there's some +really nice new products in the LED + + align:start position:0% +really nice new products in the LED + + + align:start position:0% +really nice new products in the LED +department and while they're expensive + + align:start position:0% +department and while they're expensive + + + align:start position:0% +department and while they're expensive +their lightness is just awesome you can + + align:start position:0% +their lightness is just awesome you can + + + align:start position:0% +their lightness is just awesome you can +pretty much if you go all LEDs you can + + align:start position:0% +pretty much if you go all LEDs you can + + + align:start position:0% +pretty much if you go all LEDs you can +cut the weight uh and size of your + + align:start position:0% +cut the weight uh and size of your + + + align:start position:0% +cut the weight uh and size of your +lighting kit in half so there's + + align:start position:0% +lighting kit in half so there's + + + align:start position:0% +lighting kit in half so there's +something to be said for for + + align:start position:0% +something to be said for for + + + align:start position:0% +something to be said for for +High-Tech uh if you're just starting out + + align:start position:0% +High-Tech uh if you're just starting out + + + align:start position:0% +High-Tech uh if you're just starting out +you don't have any lighting at all and + + align:start position:0% +you don't have any lighting at all and + + + align:start position:0% +you don't have any lighting at all and +you'd like a little something to start + + align:start position:0% +you'd like a little something to start + + + align:start position:0% +you'd like a little something to start +with uh one suggestion is um an open + + align:start position:0% +with uh one suggestion is um an open + + + align:start position:0% +with uh one suggestion is um an open +face light with an umbrella uh L makes + + align:start position:0% +face light with an umbrella uh L makes + + + align:start position:0% +face light with an umbrella uh L makes +this light called the toal light and + + align:start position:0% +this light called the toal light and + + + align:start position:0% +this light called the toal light and +they also have a newer version called + + align:start position:0% +they also have a newer version called + + + align:start position:0% +they also have a newer version called +The V light which is a little safer uh + + align:start position:0% +The V light which is a little safer uh + + + align:start position:0% +The V light which is a little safer uh +but this is basically just an open face + + align:start position:0% +but this is basically just an open face + + + align:start position:0% +but this is basically just an open face +light unit um and used with an umbrella + + align:start position:0% +light unit um and used with an umbrella + + + align:start position:0% +light unit um and used with an umbrella +bouncing the light you can now have a + + align:start position:0% +bouncing the light you can now have a + + + align:start position:0% +bouncing the light you can now have a +choice between a hard light or a soft + + align:start position:0% +choice between a hard light or a soft + + + align:start position:0% +choice between a hard light or a soft +light and so you can get a very quick + + align:start position:0% +light and so you can get a very quick + + + align:start position:0% +light and so you can get a very quick +and easy lightweight soft Source by + + align:start position:0% +and easy lightweight soft Source by + + + align:start position:0% +and easy lightweight soft Source by +bouncing the TOA off the umbrella and + + align:start position:0% +bouncing the TOA off the umbrella and + + + align:start position:0% +bouncing the TOA off the umbrella and +there's your soft light and you can put + + align:start position:0% +there's your soft light and you can put + + + align:start position:0% +there's your soft light and you can put +this kit together including a small + + align:start position:0% +this kit together including a small + + + align:start position:0% +this kit together including a small +light stand for less than $250 from your + + align:start position:0% +light stand for less than $250 from your + + + align:start position:0% +light stand for less than $250 from your +favorite online equipment retailer or + + align:start position:0% +favorite online equipment retailer or + + + align:start position:0% +favorite online equipment retailer or +your local + + align:start position:0% +your local + + + align:start position:0% +your local +Photoshop um set that sells video and + + align:start position:0% +Photoshop um set that sells video and + + + align:start position:0% +Photoshop um set that sells video and +and lighting equipment uh so this is the + + align:start position:0% +and lighting equipment uh so this is the + + + align:start position:0% +and lighting equipment uh so this is the +low todal or the low V light um as as a + + align:start position:0% +low todal or the low V light um as as a + + + align:start position:0% +low todal or the low V light um as as a +great starter kit you can put this in a + + align:start position:0% +great starter kit you can put this in a + + + align:start position:0% +great starter kit you can put this in a +teeny duffel bag I've often taken + + align:start position:0% +teeny duffel bag I've often taken + + + align:start position:0% +teeny duffel bag I've often taken +something like this with me on the train + + align:start position:0% +something like this with me on the train + + + align:start position:0% +something like this with me on the train +down to New York camera on one shoulder + + align:start position:0% +down to New York camera on one shoulder + + + align:start position:0% +down to New York camera on one shoulder +with sound gear and this in a on the + + align:start position:0% +with sound gear and this in a on the + + + align:start position:0% +with sound gear and this in a on the +other shoulder very light simple + + align:start position:0% +other shoulder very light simple + + + align:start position:0% +other shoulder very light simple +effective then you know over time you + + align:start position:0% +effective then you know over time you + + + align:start position:0% +effective then you know over time you +might want to add you know additional + + align:start position:0% +might want to add you know additional + + + align:start position:0% +might want to add you know additional +units depending on your particular + + align:start position:0% +units depending on your particular + + + align:start position:0% +units depending on your particular +lighting style you know a lot of people + + align:start position:0% +lighting style you know a lot of people + + + align:start position:0% +lighting style you know a lot of people +ask me what lighting kit do you + + align:start position:0% +ask me what lighting kit do you + + + align:start position:0% +ask me what lighting kit do you +recommend well it's really hard for me + + align:start position:0% +recommend well it's really hard for me + + + align:start position:0% +recommend well it's really hard for me +to recommend a lighting kit because it + + align:start position:0% +to recommend a lighting kit because it + + + align:start position:0% +to recommend a lighting kit because it +really depends on what your preferences + + align:start position:0% +really depends on what your preferences + + + align:start position:0% +really depends on what your preferences +are and what you want to accomplish so I + + align:start position:0% +are and what you want to accomplish so I + + + align:start position:0% +are and what you want to accomplish so I +would suggest you know buy one light at + + align:start position:0% +would suggest you know buy one light at + + + align:start position:0% +would suggest you know buy one light at +a time learn it get to know it and + + align:start position:0% +a time learn it get to know it and + + + align:start position:0% +a time learn it get to know it and +figure out what you want next start with + + align:start position:0% +figure out what you want next start with + + + align:start position:0% +figure out what you want next start with +a basic soft light and go from there you + + align:start position:0% +a basic soft light and go from there you + + + align:start position:0% +a basic soft light and go from there you +might want to add some Fels you might + + align:start position:0% +might want to add some Fels you might + + + align:start position:0% +might want to add some Fels you might +want to add some LED lights you might + + align:start position:0% +want to add some LED lights you might + + + align:start position:0% +want to add some LED lights you might +want to add a flex fill reflector which + + align:start position:0% +want to add a flex fill reflector which + + + align:start position:0% +want to add a flex fill reflector which +you'll see in the live demo portion um + + align:start position:0% +you'll see in the live demo portion um + + + align:start position:0% +you'll see in the live demo portion um +so these are various things that you + + align:start position:0% +so these are various things that you + + + align:start position:0% +so these are various things that you +might want to add but you know explore + + align:start position:0% +might want to add but you know explore + + + align:start position:0% +might want to add but you know explore +use it and figure out what you need a + + align:start position:0% +use it and figure out what you need a + + + align:start position:0% +use it and figure out what you need a +lot of a lot of uh towns have rental + + align:start position:0% +lot of a lot of uh towns have rental + + + align:start position:0% +lot of a lot of uh towns have rental +houses that you can rent light kits rent + + align:start position:0% +houses that you can rent light kits rent + + + align:start position:0% +houses that you can rent light kits rent +a kit for a weekend get to know it + + align:start position:0% +a kit for a weekend get to know it + + + align:start position:0% +a kit for a weekend get to know it +decide what you like what works for you + + align:start position:0% +decide what you like what works for you + + + align:start position:0% +decide what you like what works for you +what doesn't work for + + align:start position:0% +what doesn't work for + + + align:start position:0% +what doesn't work for +you um just remember it all starts with + + align:start position:0% +you um just remember it all starts with + + + align:start position:0% +you um just remember it all starts with +a good key light so definitely at some + + align:start position:0% +a good key light so definitely at some + + + align:start position:0% +a good key light so definitely at some +point you want to have something like a + + align:start position:0% +point you want to have something like a + + + align:start position:0% +point you want to have something like a +low Rea light or a diva kinof flow Diva + + align:start position:0% +low Rea light or a diva kinof flow Diva + + + align:start position:0% +low Rea light or a diva kinof flow Diva +light um as as your staple um soft light + + align:start position:0% +light um as as your staple um soft light + + + align:start position:0% +light um as as your staple um soft light +and then we talked about diffusion + + align:start position:0% +and then we talked about diffusion + + + align:start position:0% +and then we talked about diffusion +material that you can get this it sort + + align:start position:0% +material that you can get this it sort + + + align:start position:0% +material that you can get this it sort +of looks like opaque kind of gel that + + align:start position:0% +of looks like opaque kind of gel that + + + align:start position:0% +of looks like opaque kind of gel that +will soften any light that's why it's + + align:start position:0% +will soften any light that's why it's + + + align:start position:0% +will soften any light that's why it's +nice to have a few hard lights because + + align:start position:0% +nice to have a few hard lights because + + + align:start position:0% +nice to have a few hard lights because +you can always soften them with gels uh + + align:start position:0% +you can always soften them with gels uh + + + align:start position:0% +you can always soften them with gels uh +color changing gels there's this whole + + align:start position:0% +color changing gels there's this whole + + + align:start position:0% +color changing gels there's this whole +series called CTB for color temperature + + align:start position:0% +series called CTB for color temperature + + + align:start position:0% +series called CTB for color temperature +blue CTO for color temperature orange + + align:start position:0% +blue CTO for color temperature orange + + + align:start position:0% +blue CTO for color temperature orange +you can use these gels for changing the + + align:start position:0% +you can use these gels for changing the + + + align:start position:0% +you can use these gels for changing the +color of light sources black wrap is an + + align:start position:0% +color of light sources black wrap is an + + + align:start position:0% +color of light sources black wrap is an +interesting material it's aluminum foil + + align:start position:0% +interesting material it's aluminum foil + + + align:start position:0% +interesting material it's aluminum foil +with flame retardant black paint you can + + align:start position:0% +with flame retardant black paint you can + + + align:start position:0% +with flame retardant black paint you can +use that that if if light is spilling + + align:start position:0% +use that that if if light is spilling + + + align:start position:0% +use that that if if light is spilling +from a light unit you use the black wrap + + align:start position:0% +from a light unit you use the black wrap + + + align:start position:0% +from a light unit you use the black wrap +to kind of Kill The Spill off the light + + align:start position:0% +to kind of Kill The Spill off the light + + + align:start position:0% +to kind of Kill The Spill off the light +and you won't start any fires because + + align:start position:0% +and you won't start any fires because + + + align:start position:0% +and you won't start any fires because +it's flame retardant and it's metal foil + + align:start position:0% +it's flame retardant and it's metal foil + + + align:start position:0% +it's flame retardant and it's metal foil +does get hot though and uh several + + align:start position:0% +does get hot though and uh several + + + align:start position:0% +does get hot though and uh several +manufacturers make these great little + + align:start position:0% +manufacturers make these great little + + + align:start position:0% +manufacturers make these great little +wrapping things called jelly rolls that + + align:start position:0% +wrapping things called jelly rolls that + + + align:start position:0% +wrapping things called jelly rolls that +you can roll up your gels in and they + + align:start position:0% +you can roll up your gels in and they + + + align:start position:0% +you can roll up your gels in and they +come in both small and large sizes + + align:start position:0% +come in both small and large sizes + + + align:start position:0% +come in both small and large sizes +dimmers are handy for dimming lights but + + align:start position:0% +dimmers are handy for dimming lights but + + + align:start position:0% +dimmers are handy for dimming lights but +I'll warn you now that they create cycle + + align:start position:0% +I'll warn you now that they create cycle + + + align:start position:0% +I'll warn you now that they create cycle +hum and Buzz and very often light lights + + align:start position:0% +hum and Buzz and very often light lights + + + align:start position:0% +hum and Buzz and very often light lights +will the filament of lights will buzz so + + align:start position:0% +will the filament of lights will buzz so + + + align:start position:0% +will the filament of lights will buzz so +if you carry dimmers on the set uh if + + align:start position:0% +if you carry dimmers on the set uh if + + + align:start position:0% +if you carry dimmers on the set uh if +you're working with a sound person they + + align:start position:0% +you're working with a sound person they + + + align:start position:0% +you're working with a sound person they +will talk to you about it so dimmers are + + align:start position:0% +will talk to you about it so dimmers are + + + align:start position:0% +will talk to you about it so dimmers are +useful but they're tricky because of the + + align:start position:0% +useful but they're tricky because of the + + + align:start position:0% +useful but they're tricky because of the +uh interference problems uh but they can + + align:start position:0% +uh interference problems uh but they can + + + align:start position:0% +uh interference problems uh but they can +you know in some cases they can be + + align:start position:0% +you know in some cases they can be + + + align:start position:0% +you know in some cases they can be +used Cube Taps are useful for turning + + align:start position:0% +used Cube Taps are useful for turning + + + align:start position:0% +used Cube Taps are useful for turning +one Outlet into three want to be careful + + align:start position:0% +one Outlet into three want to be careful + + + align:start position:0% +one Outlet into three want to be careful +with those two prong to three-prong + + align:start position:0% +with those two prong to three-prong + + + align:start position:0% +with those two prong to three-prong +adapters but in a lot of older houses + + align:start position:0% +adapters but in a lot of older houses + + + align:start position:0% +adapters but in a lot of older houses +they don't have three prong plugs my own + + align:start position:0% +they don't have three prong plugs my own + + + align:start position:0% +they don't have three prong plugs my own +included um gloves are handy if you um I + + align:start position:0% +included um gloves are handy if you um I + + + align:start position:0% +included um gloves are handy if you um I +usually handle uh lights without gloves + + align:start position:0% +usually handle uh lights without gloves + + + align:start position:0% +usually handle uh lights without gloves +because I know exactly where the hot + + align:start position:0% +because I know exactly where the hot + + + align:start position:0% +because I know exactly where the hot +parts are and where the hot Parts aren't + + align:start position:0% +parts are and where the hot Parts aren't + + + align:start position:0% +parts are and where the hot Parts aren't +from years of experience but when you're + + align:start position:0% +from years of experience but when you're + + + align:start position:0% +from years of experience but when you're +starting out you might want to use + + align:start position:0% +starting out you might want to use + + + align:start position:0% +starting out you might want to use +gloves um and be careful gaffer tape is + + align:start position:0% +gloves um and be careful gaffer tape is + + + align:start position:0% +gloves um and be careful gaffer tape is +the will solve any problem that the + + align:start position:0% +the will solve any problem that the + + + align:start position:0% +the will solve any problem that the +lighting instruments can't solve in most + + align:start position:0% +lighting instruments can't solve in most + + + align:start position:0% +lighting instruments can't solve in most +cases and I won't go into detail but as + + align:start position:0% +cases and I won't go into detail but as + + + align:start position:0% +cases and I won't go into detail but as +you expand your uh lighting work you + + align:start position:0% +you expand your uh lighting work you + + + align:start position:0% +you expand your uh lighting work you +might want to add things like flags and + + align:start position:0% +might want to add things like flags and + + + align:start position:0% +might want to add things like flags and +Nets for for sculpting light but that's + + align:start position:0% +Nets for for sculpting light but that's + + + align:start position:0% +Nets for for sculpting light but that's +beyond the scope of this talk if you + + align:start position:0% +beyond the scope of this talk if you + + + align:start position:0% +beyond the scope of this talk if you +ever have larger lights you're going to + + align:start position:0% +ever have larger lights you're going to + + + align:start position:0% +ever have larger lights you're going to +need to put sandbags on the stands so + + align:start position:0% +need to put sandbags on the stands so + + + align:start position:0% +need to put sandbags on the stands so +having some portable Beach is very very + + align:start position:0% +having some portable Beach is very very + + + align:start position:0% +having some portable Beach is very very +handy and there's the universal sea + + align:start position:0% +handy and there's the universal sea + + + align:start position:0% +handy and there's the universal sea +stand that's uh can you be used for all + + align:start position:0% +stand that's uh can you be used for all + + + align:start position:0% +stand that's uh can you be used for all +sorts of things hanging sound blankets + + align:start position:0% +sorts of things hanging sound blankets + + + align:start position:0% +sorts of things hanging sound blankets +in addition to holding lights and stuff + + align:start position:0% +in addition to holding lights and stuff + + + align:start position:0% +in addition to holding lights and stuff +and there's a lot of gripy that we're + + align:start position:0% +and there's a lot of gripy that we're + + + align:start position:0% +and there's a lot of gripy that we're +not going to get into today but it's + + align:start position:0% +not going to get into today but it's + + + align:start position:0% +not going to get into today but it's +good to know that there is this whole um + + align:start position:0% +good to know that there is this whole um + + + align:start position:0% +good to know that there is this whole um +collection of gear out + + align:start position:0% +collection of gear out + + + align:start position:0% +collection of gear out +there but some that are useful is if + + align:start position:0% +there but some that are useful is if + + + align:start position:0% +there but some that are useful is if +you're working in an environment with uh + + align:start position:0% +you're working in an environment with uh + + + align:start position:0% +you're working in an environment with uh +drop ceilings these little scissor + + align:start position:0% +drop ceilings these little scissor + + + align:start position:0% +drop ceilings these little scissor +clamps are great which will give you a + + align:start position:0% +clamps are great which will give you a + + + align:start position:0% +clamps are great which will give you a +standard 5/8 inch stud for hanging a + + align:start position:0% +standard 5/8 inch stud for hanging a + + + align:start position:0% +standard 5/8 inch stud for hanging a +small light it's good to have a couple + + align:start position:0% +small light it's good to have a couple + + + align:start position:0% +small light it's good to have a couple +of those in your kit mayfer clamps are + + align:start position:0% +of those in your kit mayfer clamps are + + + align:start position:0% +of those in your kit mayfer clamps are +very handy also known as photo clamps + + align:start position:0% +very handy also known as photo clamps + + + align:start position:0% +very handy also known as photo clamps +depending on who you ask um these are + + align:start position:0% +depending on who you ask um these are + + + align:start position:0% +depending on who you ask um these are +great clamps that you can attach to + + align:start position:0% +great clamps that you can attach to + + + align:start position:0% +great clamps that you can attach to +pipes and all sorts of conduit and + + align:start position:0% +pipes and all sorts of conduit and + + + align:start position:0% +pipes and all sorts of conduit and +things if you need um you'll notice that + + align:start position:0% +things if you need um you'll notice that + + + align:start position:0% +things if you need um you'll notice that +for all small lights the industry + + align:start position:0% +for all small lights the industry + + + align:start position:0% +for all small lights the industry +standard is a 5/8 inch stud it's also + + align:start position:0% +standard is a 5/8 inch stud it's also + + + align:start position:0% +standard is a 5/8 inch stud it's also +known as a baby stud grip Clips are + + align:start position:0% +known as a baby stud grip Clips are + + + align:start position:0% +known as a baby stud grip Clips are +great um you can buy official grip Clips + + align:start position:0% +great um you can buy official grip Clips + + + align:start position:0% +great um you can buy official grip Clips +you can go to the hardware store and buy + + align:start position:0% +you can go to the hardware store and buy + + + align:start position:0% +you can go to the hardware store and buy +the equivalent for a fraction of the + + align:start position:0% +the equivalent for a fraction of the + + + align:start position:0% +the equivalent for a fraction of the +price um I still use a light meter + + align:start position:0% +price um I still use a light meter + + + align:start position:0% +price um I still use a light meter +sometimes when I'm setting up lights but + + align:start position:0% +sometimes when I'm setting up lights but + + + align:start position:0% +sometimes when I'm setting up lights but +that's probably an + + align:start position:0% +that's probably an + + + align:start position:0% +that's probably an +anachronism though it is Handy to have + + align:start position:0% +anachronism though it is Handy to have + + + align:start position:0% +anachronism though it is Handy to have +an 18% gray card white on one side for + + align:start position:0% +an 18% gray card white on one side for + + + align:start position:0% +an 18% gray card white on one side for +white balance gray on the other side uh + + align:start position:0% +white balance gray on the other side uh + + + align:start position:0% +white balance gray on the other side uh +very often if you're color correcting a + + align:start position:0% +very often if you're color correcting a + + + align:start position:0% +very often if you're color correcting a +scene and you put that gray card in the + + align:start position:0% +scene and you put that gray card in the + + + align:start position:0% +scene and you put that gray card in the +scene and now you have a gray reference + + align:start position:0% +scene and now you have a gray reference + + + align:start position:0% +scene and now you have a gray reference +so if you're color obsessed like myself + + align:start position:0% +so if you're color obsessed like myself + + + align:start position:0% +so if you're color obsessed like myself +you might want to carry a gray card in + + align:start position:0% +you might want to carry a gray card in + + + align:start position:0% +you might want to carry a gray card in +your kit but um and there's a list here + + align:start position:0% +your kit but um and there's a list here + + + align:start position:0% +your kit but um and there's a list here +of other things um this is sort of a + + align:start position:0% +of other things um this is sort of a + + + align:start position:0% +of other things um this is sort of a +homework assignment figure out what all + + align:start position:0% +homework assignment figure out what all + + + align:start position:0% +homework assignment figure out what all +these things are it's a good good thing + + align:start position:0% +these things are it's a good good thing + + + align:start position:0% +these things are it's a good good thing +to learn um you know at the end of the + + align:start position:0% +to learn um you know at the end of the + + + align:start position:0% +to learn um you know at the end of the +day just remember there are no rules + + align:start position:0% +day just remember there are no rules + + + align:start position:0% +day just remember there are no rules +about what is good lighting and bad + + align:start position:0% +about what is good lighting and bad + + + align:start position:0% +about what is good lighting and bad +lighting um because one person's bad + + align:start position:0% +lighting um because one person's bad + + + align:start position:0% +lighting um because one person's bad +lighting is another person's dramatic + + align:start position:0% +lighting is another person's dramatic + + + align:start position:0% +lighting is another person's dramatic +lighting um it might be bad if it + + align:start position:0% +lighting um it might be bad if it + + + align:start position:0% +lighting um it might be bad if it +creates the wrong Ambience for the scene + + align:start position:0% +creates the wrong Ambience for the scene + + + align:start position:0% +creates the wrong Ambience for the scene +or produces an unintended unflattering + + align:start position:0% +or produces an unintended unflattering + + + align:start position:0% +or produces an unintended unflattering +effect or it distracts the viewer's + + align:start position:0% +effect or it distracts the viewer's + + + align:start position:0% +effect or it distracts the viewer's +attention remember we were talking about + + align:start position:0% +attention remember we were talking about + + + align:start position:0% +attention remember we were talking about +we use light + + align:start position:0% +we use light + + + align:start position:0% +we use light +to drive the viewer's attention in the + + align:start position:0% +to drive the viewer's attention in the + + + align:start position:0% +to drive the viewer's attention in the +scene but if it's not doing that then + + align:start position:0% +scene but if it's not doing that then + + + align:start position:0% +scene but if it's not doing that then +maybe it is bad lighting does it prevent + + align:start position:0% +maybe it is bad lighting does it prevent + + + align:start position:0% +maybe it is bad lighting does it prevent +the viewer from seeing what's + + align:start position:0% +the viewer from seeing what's + + + align:start position:0% +the viewer from seeing what's +important or is it showing things that + + align:start position:0% +important or is it showing things that + + + align:start position:0% +important or is it showing things that +are irrelevant so one of the biggest + + align:start position:0% +are irrelevant so one of the biggest + + + align:start position:0% +are irrelevant so one of the biggest +problems with point and shoot video is + + align:start position:0% +problems with point and shoot video is + + + align:start position:0% +problems with point and shoot video is +that often times our subject is obscured + + align:start position:0% +that often times our subject is obscured + + + align:start position:0% +that often times our subject is obscured +and something that's completely + + align:start position:0% +and something that's completely + + + align:start position:0% +and something that's completely +unimportant is is staring at you know + + align:start position:0% +unimportant is is staring at you know + + + align:start position:0% +unimportant is is staring at you know +staring us right at the face so think + + align:start position:0% +staring us right at the face so think + + + align:start position:0% +staring us right at the face so think +about what is it doing for you and your + + align:start position:0% +about what is it doing for you and your + + + align:start position:0% +about what is it doing for you and your +own storytelling good lighting allows us + + align:start position:0% +own storytelling good lighting allows us + + + align:start position:0% +own storytelling good lighting allows us +to do many many things I'm not going to + + align:start position:0% +to do many many things I'm not going to + + + align:start position:0% +to do many many things I'm not going to +go through this whole list but once + + align:start position:0% +go through this whole list but once + + + align:start position:0% +go through this whole list but once +again it can help us draw attention to + + align:start position:0% +again it can help us draw attention to + + + align:start position:0% +again it can help us draw attention to +what's important in the scene it can + + align:start position:0% +what's important in the scene it can + + + align:start position:0% +what's important in the scene it can +help isolate the subject it could imply + + align:start position:0% +help isolate the subject it could imply + + + align:start position:0% +help isolate the subject it could imply +a season it could establish a local it + + align:start position:0% +a season it could establish a local it + + + align:start position:0% +a season it could establish a local it +can concentrate attention to a + + align:start position:0% +can concentrate attention to a + + + align:start position:0% +can concentrate attention to a +particular part of the scene it can + + align:start position:0% +particular part of the scene it can + + + align:start position:0% +particular part of the scene it can +emphasize form like we talked about with + + align:start position:0% +emphasize form like we talked about with + + + align:start position:0% +emphasize form like we talked about with +Kos skuro or we can deemphasize form + + align:start position:0% +Kos skuro or we can deemphasize form + + + align:start position:0% +Kos skuro or we can deemphasize form +with flat lighting at the end of the day + + align:start position:0% +with flat lighting at the end of the day + + + align:start position:0% +with flat lighting at the end of the day +it's about altering the viewer's + + align:start position:0% +it's about altering the viewer's + + + align:start position:0% +it's about altering the viewer's +emotional response um and establishing a + + align:start position:0% +emotional response um and establishing a + + + align:start position:0% +emotional response um and establishing a +mood and so here's kind of my laundry + + align:start position:0% +mood and so here's kind of my laundry + + + align:start position:0% +mood and so here's kind of my laundry +list of all the things that lighting can + + align:start position:0% +list of all the things that lighting can + + + align:start position:0% +list of all the things that lighting can +do for you and through experience and + + align:start position:0% +do for you and through experience and + + + align:start position:0% +do for you and through experience and +through practice you will see how what + + align:start position:0% +through practice you will see how what + + + align:start position:0% +through practice you will see how what +you do with lighting has an impact in + + align:start position:0% +you do with lighting has an impact in + + + align:start position:0% +you do with lighting has an impact in +your storytelling um so that's kind of a + + align:start position:0% +your storytelling um so that's kind of a + + + align:start position:0% +your storytelling um so that's kind of a +list of all the things that lighting + + align:start position:0% +list of all the things that lighting + + + align:start position:0% +list of all the things that lighting +lighting can do for you and at the end + + align:start position:0% +lighting can do for you and at the end + + + align:start position:0% +lighting can do for you and at the end +here um there's a there's a a brief + + align:start position:0% +here um there's a there's a a brief + + + align:start position:0% +here um there's a there's a a brief +glossery of terms of Enlightenment uh + + align:start position:0% +glossery of terms of Enlightenment uh + + + align:start position:0% +glossery of terms of Enlightenment uh +which is a word I borrowed from Ross LEL + + align:start position:0% +which is a word I borrowed from Ross LEL + + + align:start position:0% +which is a word I borrowed from Ross LEL +who wrote a wonderful book called + + align:start position:0% +who wrote a wonderful book called + + + align:start position:0% +who wrote a wonderful book called +matters of light and depth which I + + align:start position:0% +matters of light and depth which I + + + align:start position:0% +matters of light and depth which I +highly + + align:start position:0% +highly + + + align:start position:0% +highly +recommend um there's electricity + + align:start position:0% +recommend um there's electricity + + + align:start position:0% +recommend um there's electricity +involved in lighting and you want to be + + align:start position:0% +involved in lighting and you want to be + + + align:start position:0% +involved in lighting and you want to be +very careful + + align:start position:0% +very careful + + + align:start position:0% +very careful +um and treat it with respect and if you + + align:start position:0% +um and treat it with respect and if you + + + align:start position:0% +um and treat it with respect and if you +have frayed wires or anything damaged in + + align:start position:0% +have frayed wires or anything damaged in + + + align:start position:0% +have frayed wires or anything damaged in +your lighting equipment you want to fix + + align:start position:0% +your lighting equipment you want to fix + + + align:start position:0% +your lighting equipment you want to fix +it before you plug it into the wall uh + + align:start position:0% +it before you plug it into the wall uh + + + align:start position:0% +it before you plug it into the wall uh +what you what you have here is a simple + + align:start position:0% +what you what you have here is a simple + + + align:start position:0% +what you what you have here is a simple +calculator for determining do you have + + align:start position:0% +calculator for determining do you have + + + align:start position:0% +calculator for determining do you have +enough power to light to provide the + + align:start position:0% +enough power to light to provide the + + + align:start position:0% +enough power to light to provide the +power for your lighting units so the way + + align:start position:0% +power for your lighting units so the way + + + align:start position:0% +power for your lighting units so the way +to remember it is a 20 amp circuit a 20 + + align:start position:0% +to remember it is a 20 amp circuit a 20 + + + align:start position:0% +to remember it is a 20 amp circuit a 20 +amp household circuit which is pretty + + align:start position:0% +amp household circuit which is pretty + + + align:start position:0% +amp household circuit which is pretty +standard in bathrooms and kitchens in + + align:start position:0% +standard in bathrooms and kitchens in + + + align:start position:0% +standard in bathrooms and kitchens in +contemporary Construction in a lot of + + align:start position:0% +contemporary Construction in a lot of + + + align:start position:0% +contemporary Construction in a lot of +older houses you will find 15 amp + + align:start position:0% +older houses you will find 15 amp + + + align:start position:0% +older houses you will find 15 amp +circuits but the thing to remember a 20 + + align:start position:0% +circuits but the thing to remember a 20 + + + align:start position:0% +circuits but the thing to remember a 20 +amp circuit can support 2,000 Watts + + align:start position:0% +amp circuit can support 2,000 Watts + + + align:start position:0% +amp circuit can support 2,000 Watts +that's the only number you need to + + align:start position:0% +that's the only number you need to + + + align:start position:0% +that's the only number you need to +remember and you can extrapolate from + + align:start position:0% +remember and you can extrapolate from + + + align:start position:0% +remember and you can extrapolate from +there a 20 amp circuit gives you can + + align:start position:0% +there a 20 amp circuit gives you can + + + align:start position:0% +there a 20 amp circuit gives you can +feed two 2,000 Watts because you just + + align:start position:0% +feed two 2,000 Watts because you just + + + align:start position:0% +feed two 2,000 Watts because you just +basically take the amps and + + align:start position:0% +basically take the amps and + + + align:start position:0% +basically take the amps and +multiply by uh 100 right amps + + align:start position:0% +multiply by uh 100 right amps + + + align:start position:0% +multiply by uh 100 right amps +um are basically a measure of how much + + align:start position:0% +um are basically a measure of how much + + + align:start position:0% +um are basically a measure of how much +current how much oomph you're drawing + + align:start position:0% +current how much oomph you're drawing + + + align:start position:0% +current how much oomph you're drawing +from that circuit and the wattage of a + + align:start position:0% +from that circuit and the wattage of a + + + align:start position:0% +from that circuit and the wattage of a +lamp 2,000 Watts 100 watt watts is how + + align:start position:0% +lamp 2,000 Watts 100 watt watts is how + + + align:start position:0% +lamp 2,000 Watts 100 watt watts is how +much energy that lamp is putting to work + + align:start position:0% +much energy that lamp is putting to work + + + align:start position:0% +much energy that lamp is putting to work +so the important thing is is that you + + align:start position:0% +so the important thing is is that you + + + align:start position:0% +so the important thing is is that you +don't want to draw more current from the + + align:start position:0% +don't want to draw more current from the + + + align:start position:0% +don't want to draw more current from the +circuit than it can take because then + + align:start position:0% +circuit than it can take because then + + + align:start position:0% +circuit than it can take because then +you'll pop the circuit breaker so + + align:start position:0% +you'll pop the circuit breaker so + + + align:start position:0% +you'll pop the circuit breaker so +whenever you set up a lighting kit um if + + align:start position:0% +whenever you set up a lighting kit um if + + + align:start position:0% +whenever you set up a lighting kit um if +your total lighting kit uses only uses + + align:start position:0% +your total lighting kit uses only uses + + + align:start position:0% +your total lighting kit uses only uses +1,500 Watts you probably don't have to + + align:start position:0% +1,500 Watts you probably don't have to + + + align:start position:0% +1,500 Watts you probably don't have to +worry about popping an ordinary breaker + + align:start position:0% +worry about popping an ordinary breaker + + + align:start position:0% +worry about popping an ordinary breaker +but you want to know where the breaker + + align:start position:0% +but you want to know where the breaker + + + align:start position:0% +but you want to know where the breaker +box is just in case and whenever I go + + align:start position:0% +box is just in case and whenever I go + + + align:start position:0% +box is just in case and whenever I go +into somebody's home to do an interview + + align:start position:0% +into somebody's home to do an interview + + + align:start position:0% +into somebody's home to do an interview +or whatever I always ask them do you + + align:start position:0% +or whatever I always ask them do you + + + align:start position:0% +or whatever I always ask them do you +have anything plugged in that if the + + align:start position:0% +have anything plugged in that if the + + + align:start position:0% +have anything plugged in that if the +power went out would cause some sort of + + align:start position:0% +power went out would cause some sort of + + + align:start position:0% +power went out would cause some sort of +disaster always ask um there are times + + align:start position:0% +disaster always ask um there are times + + + align:start position:0% +disaster always ask um there are times +for example when I've run extension + + align:start position:0% +for example when I've run extension + + + align:start position:0% +for example when I've run extension +cords into a kitchen to power an + + align:start position:0% +cords into a kitchen to power an + + + align:start position:0% +cords into a kitchen to power an +interview in a living room because + + align:start position:0% +interview in a living room because + + + align:start position:0% +interview in a living room because +somebody had their computer set up and + + align:start position:0% +somebody had their computer set up and + + + align:start position:0% +somebody had their computer set up and +they didn't want to turn it off and + + align:start position:0% +they didn't want to turn it off and + + + align:start position:0% +they didn't want to turn it off and +whatever you just don't want to mess + + align:start position:0% +whatever you just don't want to mess + + + align:start position:0% +whatever you just don't want to mess +with it but the thing is you can in + + align:start position:0% +with it but the thing is you can in + + + align:start position:0% +with it but the thing is you can in +modern construction you can always count + + align:start position:0% +modern construction you can always count + + + align:start position:0% +modern construction you can always count +on a solid 20 amp circuit in a kitchen + + align:start position:0% +on a solid 20 amp circuit in a kitchen + + + align:start position:0% +on a solid 20 amp circuit in a kitchen +or a + + align:start position:0% +or a + + + align:start position:0% +or a +bathroom and usually there's nothing + + align:start position:0% +bathroom and usually there's nothing + + + align:start position:0% +bathroom and usually there's nothing +else plugged into that + + align:start position:0% +else plugged into that + + + align:start position:0% +else plugged into that +circuit um so this will go into some + + align:start position:0% +circuit um so this will go into some + + + align:start position:0% +circuit um so this will go into some +safety tips um common sense that you + + align:start position:0% +safety tips um common sense that you + + + align:start position:0% +safety tips um common sense that you +should + + align:start position:0% +should + + + align:start position:0% +should +read and I mentioned uh a good resource + + align:start position:0% +read and I mentioned uh a good resource + + + align:start position:0% +read and I mentioned uh a good resource +for further study is Ross lel's + + align:start position:0% +for further study is Ross lel's + + + align:start position:0% +for further study is Ross lel's +wonderful book matters of of of light + + align:start position:0% +wonderful book matters of of of light + + + align:start position:0% +wonderful book matters of of of light +and depth to date it's the best book + + align:start position:0% +and depth to date it's the best book + + + align:start position:0% +and depth to date it's the best book +ever written about lighting it's written + + align:start position:0% +ever written about lighting it's written + + + align:start position:0% +ever written about lighting it's written +from the point of view of a lot of + + align:start position:0% +from the point of view of a lot of + + + align:start position:0% +from the point of view of a lot of +experience and what's interesting about + + align:start position:0% +experience and what's interesting about + + + align:start position:0% +experience and what's interesting about +Ross LEL is he has done a lot of + + align:start position:0% +Ross LEL is he has done a lot of + + + align:start position:0% +Ross LEL is he has done a lot of +shooting with a minimal amount of gear + + align:start position:0% +shooting with a minimal amount of gear + + + align:start position:0% +shooting with a minimal amount of gear +and it's written from the point of view + + align:start position:0% +and it's written from the point of view + + + align:start position:0% +and it's written from the point of view +of getting the most out of the least + + align:start position:0% +of getting the most out of the least + + + align:start position:0% +of getting the most out of the least +amount of gear uh in terms of lighting + + align:start position:0% +amount of gear uh in terms of lighting + + + align:start position:0% +amount of gear uh in terms of lighting +and Ross LEL developed a company uh LEL + + align:start position:0% +and Ross LEL developed a company uh LEL + + + align:start position:0% +and Ross LEL developed a company uh LEL +lights um to sell his at the time he + + align:start position:0% +lights um to sell his at the time he + + + align:start position:0% +lights um to sell his at the time he +developed a whole new generation of + + align:start position:0% +developed a whole new generation of + + + align:start position:0% +developed a whole new generation of +lightweight lighting units which were + + align:start position:0% +lightweight lighting units which were + + + align:start position:0% +lightweight lighting units which were +very popular among documentarian who + + align:start position:0% +very popular among documentarian who + + + align:start position:0% +very popular among documentarian who +didn't want to carry around big + + align:start position:0% +didn't want to carry around big + + + align:start position:0% +didn't want to carry around big +equipment cases they wanted to carry + + align:start position:0% +equipment cases they wanted to carry + + + align:start position:0% +equipment cases they wanted to carry +around small equipment cases and it's + + align:start position:0% +around small equipment cases and it's + + + align:start position:0% +around small equipment cases and it's +also written with a wonderful sense of + + align:start position:0% +also written with a wonderful sense of + + + align:start position:0% +also written with a wonderful sense of +humor you will chuckle while you read + + align:start position:0% +humor you will chuckle while you read + + + align:start position:0% +humor you will chuckle while you read +this book so matters of life and death + + align:start position:0% +this book so matters of life and death + + + align:start position:0% +this book so matters of life and death +highly recommended and there's also a + + align:start position:0% +highly recommended and there's also a + + + align:start position:0% +highly recommended and there's also a +lot of wonderful resources online um DV + + align:start position:0% +lot of wonderful resources online um DV + + + align:start position:0% +lot of wonderful resources online um DV +info.net is a wonderful discussion group + + align:start position:0% +info.net is a wonderful discussion group + + + align:start position:0% +info.net is a wonderful discussion group +for matters of of a technical nature and + + align:start position:0% +for matters of of a technical nature and + + + align:start position:0% +for matters of of a technical nature and +self-reliant film.com is a wonderful + + align:start position:0% +self-reliant film.com is a wonderful + + + align:start position:0% +self-reliant film.com is a wonderful +blog about making films do it yourself + + align:start position:0% +blog about making films do it yourself + + + align:start position:0% +blog about making films do it yourself +style which I highly + + align:start position:0% +style which I highly + + + align:start position:0% +style which I highly +recommend and that's + + align:start position:0% +recommend and that's + + + align:start position:0% +recommend and that's +it so just to to wrap up uh the second + + align:start position:0% +it so just to to wrap up uh the second + + + align:start position:0% +it so just to to wrap up uh the second +half after a short break is going to be + + align:start position:0% +half after a short break is going to be + + + align:start position:0% +half after a short break is going to be +uh the demo and a lot of the things that + + align:start position:0% +uh the demo and a lot of the things that + + + align:start position:0% +uh the demo and a lot of the things that +David talked about and showed in the the + + align:start position:0% +David talked about and showed in the the + + + align:start position:0% +David talked about and showed in the the +the PowerPoint will become a little bit + + align:start position:0% +the PowerPoint will become a little bit + + + align:start position:0% +the PowerPoint will become a little bit +clearer as we go through the demo um but + + align:start position:0% +clearer as we go through the demo um but + + + align:start position:0% +clearer as we go through the demo um but +just to to sort of wrap up a a lot of + + align:start position:0% +just to to sort of wrap up a a lot of + + + align:start position:0% +just to to sort of wrap up a a lot of +lighting especially Lighting on on our + + align:start position:0% +lighting especially Lighting on on our + + + align:start position:0% +lighting especially Lighting on on our +level beginning and sort of low no + + align:start position:0% +level beginning and sort of low no + + + align:start position:0% +level beginning and sort of low no +instrument lighting uh boils down to + + align:start position:0% +instrument lighting uh boils down to + + + align:start position:0% +instrument lighting uh boils down to +just learning how to see things and it's + + align:start position:0% +just learning how to see things and it's + + + align:start position:0% +just learning how to see things and it's +so much like other things in in shooting + + align:start position:0% +so much like other things in in shooting + + + align:start position:0% +so much like other things in in shooting +framing learning how to shoot for an + + align:start position:0% +framing learning how to shoot for an + + + align:start position:0% +framing learning how to shoot for an +edit you you really need to practice + + align:start position:0% +edit you you really need to practice + + + align:start position:0% +edit you you really need to practice +seeing what's actually there and + + align:start position:0% +seeing what's actually there and + + + align:start position:0% +seeing what's actually there and +thinking about how that is going to + + align:start position:0% +thinking about how that is going to + + + align:start position:0% +thinking about how that is going to +affect your audience you know you're the + + align:start position:0% +affect your audience you know you're the + + + align:start position:0% +affect your audience you know you're the +first audience for your film so all of + + align:start position:0% +first audience for your film so all of + + + align:start position:0% +first audience for your film so all of +the things that David talked about at + + align:start position:0% +the things that David talked about at + + + align:start position:0% +the things that David talked about at +the end really boil down to seeing + + align:start position:0% +the end really boil down to seeing + + + align:start position:0% +the end really boil down to seeing +what's there and learning how to make a + + align:start position:0% +what's there and learning how to make a + + + align:start position:0% +what's there and learning how to make a +determination about what needs to be + + align:start position:0% +determination about what needs to be + + + align:start position:0% +determination about what needs to be +changed in order to get the image that's + + align:start position:0% +changed in order to get the image that's + + + align:start position:0% +changed in order to get the image that's +going to have the impact that it needs + + align:start position:0% +going to have the impact that it needs + + + align:start position:0% +going to have the impact that it needs +to have + + align:start position:0% +to have + + + align:start position:0% +to have +uh so often and I I think I've said this + + align:start position:0% +uh so often and I I think I've said this + + + align:start position:0% +uh so often and I I think I've said this +before but so often um even people who + + align:start position:0% +before but so often um even people who + + + align:start position:0% +before but so often um even people who +have been doing film for a long time + + align:start position:0% +have been doing film for a long time + + + align:start position:0% +have been doing film for a long time +sometimes fall into the Trap of + + align:start position:0% +sometimes fall into the Trap of + + + align:start position:0% +sometimes fall into the Trap of +forgetting that you can actually make a + + align:start position:0% +forgetting that you can actually make a + + + align:start position:0% +forgetting that you can actually make a +change because it's difficult or you + + align:start position:0% +change because it's difficult or you + + + align:start position:0% +change because it's difficult or you +know it's in position it's problematic + + align:start position:0% +know it's in position it's problematic + + + align:start position:0% +know it's in position it's problematic +for somebody but if it really is + + align:start position:0% +for somebody but if it really is + + + align:start position:0% +for somebody but if it really is +necessary to make some kind of change + + align:start position:0% +necessary to make some kind of change + + + align:start position:0% +necessary to make some kind of change +it's really up to you to do it so if + + align:start position:0% +it's really up to you to do it so if + + + align:start position:0% +it's really up to you to do it so if +you're shooting in a room doing an inter + + align:start position:0% +you're shooting in a room doing an inter + + + align:start position:0% +you're shooting in a room doing an inter +interview in a room or in a location + + align:start position:0% +interview in a room or in a location + + + align:start position:0% +interview in a room or in a location +that's not going to work because the + + align:start position:0% +that's not going to work because the + + + align:start position:0% +that's not going to work because the +lighting just is impossible to to do if + + align:start position:0% +lighting just is impossible to to do if + + + align:start position:0% +lighting just is impossible to to do if +the person standing in a place that it's + + align:start position:0% +the person standing in a place that it's + + + align:start position:0% +the person standing in a place that it's +just going to be a disaster you need to + + align:start position:0% +just going to be a disaster you need to + + + align:start position:0% +just going to be a disaster you need to +make a change you need to ask them to + + align:start position:0% +make a change you need to ask them to + + + align:start position:0% +make a change you need to ask them to +move somewhere else and determining you + + align:start position:0% +move somewhere else and determining you + + + align:start position:0% +move somewhere else and determining you +know using your your experience and your + + align:start position:0% +know using your your experience and your + + + align:start position:0% +know using your your experience and your +sensitivity to what the situation is + + align:start position:0% +sensitivity to what the situation is + + + align:start position:0% +sensitivity to what the situation is +based on some of these things Davis + + align:start position:0% +based on some of these things Davis + + + align:start position:0% +based on some of these things Davis +talked about these basic principles then + + align:start position:0% +talked about these basic principles then + + + align:start position:0% +talked about these basic principles then +determines where you get them to move to + + align:start position:0% +determines where you get them to move to + + + align:start position:0% +determines where you get them to move to +what you actually what change you + + align:start position:0% +what you actually what change you + + + align:start position:0% +what you actually what change you +actually affect in order to get the + + align:start position:0% +actually affect in order to get the + + + align:start position:0% +actually affect in order to get the +image that you need to get um so that's + + align:start position:0% +image that you need to get um so that's + + + align:start position:0% +image that you need to get um so that's +it um I think the second part of this is + + align:start position:0% +it um I think the second part of this is + + + align:start position:0% +it um I think the second part of this is +going to be really fun because we're + + align:start position:0% +going to be really fun because we're + + + align:start position:0% +going to be really fun because we're +going to see some of these principles in + + align:start position:0% +going to see some of these principles in + + + align:start position:0% +going to see some of these principles in +action so thanks a lot \ No newline at end of file diff --git a/Sn-5Dwt_1qw.txt b/Sn-5Dwt_1qw.txt new file mode 100644 index 0000000000000000000000000000000000000000..f4027bf7847641b10c5519f4060dec85d76a32d7 --- /dev/null +++ b/Sn-5Dwt_1qw.txt @@ -0,0 +1,36 @@ +Hello, this is Dimitris. + +This week, our lectures focus +on applications of analytics + +into interesting areas. + +In the first lecture, +we'll describe + +how a Princeton professor +used linear regression + +to predict the quality of wine. + +In the second lecture, +we'll discuss the story + +of Moneyball, and how +data and analytics was + +used to create a +championship team. + +Through these examples, +we will teach you + +the method of linear regression. + +In both lectures, we'll use +data to replicate the models in + +R, and so how simple analytics +can create a significant edge. + +Let's get started. \ No newline at end of file diff --git a/SuOIpJnn888.txt b/SuOIpJnn888.txt new file mode 100644 index 0000000000000000000000000000000000000000..9a35a133a71b4638af13b96827f14ffa965793f0 --- /dev/null +++ b/SuOIpJnn888.txt @@ -0,0 +1,1911 @@ +OPERATOR: The following content +is provided under a + +Creative Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: So let's start. + +I have written a number +on the board here. + +Anyone want to speculate what +that number represents? + +Well, you may recall at the end +of the last lecture, we + +were simulating pi, and I +started up running it with a + +billion darts. + +And when it finally terminated, +this was the + +estimate of pi it gave +me with a billion. + +Not bad, not quite perfect, +but still pretty good. + +In fact when I later ran it with +10 billion darts, which + +took a rather long time to run, +didn't do much better. + +So it's converging very slowly +now near the end. + +When we use an algorithm like +that one to perform a Monte + +Carlo simulation, we're +trusting, as I said, that fate + +will give us an unbiased sample, +a sample that would be + +representative of true +random throws. + +And, indeed in this case, +that's a pretty good + +assumption. + +The random number generator is +not truly random, it's what's + +called pseudo-random, in that if +you start it with the same + +initial conditions, it will +give you the same results. + +But it's close enough for, at +least for government work, and + +other useful projects. + +We do have to think about the +question, how many samples + +should we run? + +Was a billion darts enough? + +Now since we sort of all started +knowing what pi was, + +we could look at it and say, +yeah, pretty good. + +But suppose we had no clue about +the actual value of pi. + +We still have to +think about the + +question of how many samples? + +And also, how accurate do we +believe our result is, given + +the number of samples? + +As you might guess, these two +questions are closely related. + +That, if we know in advance how +much accuracy we want, we + +can sometimes use that +to calculate how + +many samples we need. + +But there's still always +the issue. + +It's never possible +to achieve perfect + +accuracy through sampling. + +Unless you sample the +entire population. + +No matter how many samples you +take, you can never be sure + +that the sample set is typical +until you've checked every + +last element. + +So if I went around MIT and +sampled 100 students to try + +and, for example, guess the +fraction of students at MIT + +who are of Chinese descent. + +Maybe 100 students would be +enough, but maybe I would get + +unlucky and draw +the wrong 100. + +In the sense of, by accident, +100 Chinese descent, or 100 + +non-Chinese descent, +which would give + +me the wrong answer. + +And there would be no way I +could be sure that I had not + +drawn a biased sample, unless +I really did have the whole + +population to look at. + +So we can never know that +our estimate is correct. + +Now maybe I took a billion +darts, and for some reason got + +really unlucky and they +all ended up inside + +or outside the circle. + +But what we can know, is how +likely it is that our answer + +is correct, given +the assumptions. + +And that's the topic we'll spend +the next few lectures + +on, at least one +of the topics. + +It's saying, how can we know +how likely it is that our + +answer is good. + +But it's always given some set +of assumptions, and we have to + +worry a lot about those +assumptions. + +Now in the case of our pi +example, our assumption was + +that the random number generator +was indeed giving us + +random numbers in the +interval 0 to 1. + +So that was our underlying +assumption. + +Then using that, we looked at a +plot, and we saw that after + +time the answer wasn't +changing very much. + +And we use that to say, OK, it +looks like we're actually + +converging on an answer. + +And then I ran it again, with +another trial, and it + +converged again at +the same place. + +And the fact that that happened +several times led me + +to at least have some reason to +believe that I was actually + +finding a good approximation +of pi. + +That's a good thing to do. + +It's a necessary thing to do. + +But it is not sufficient. + +Because errors can creep +into many places. + +So that kind of technique, +and in fact, almost all + +statistical techniques, are good +at establishing, in some + +sense, the reproduce-ability of +the result, and that it is + +statistically valid, and that +there's no error, for example, + +in the way I'm generating +the numbers. + +Or I didn't get very unlucky. + +However, they're other places +other than bad luck where + +errors can creep in. + +So let's look at an +example here. + +I've taken the algorithm we +looked at last time for + +finding pi, and I've +made a change. + +You'll remember that we were +before using 4 as our + +multiplier, and here what I've +done is, just gone in and + +replaced 4 by 2. + +Assuming that I made a +programming error. + +Now let's see what happens +when we run it. + +Well, a bad thing +has happened. + +Sure enough, we ran it and +it converged, started to + +converge, and if I ran 100 +trials each one would converge + +at roughly the same place. + +Any statistical test I would +do, would say that my + +statistics are sound, I've +chosen enough samples, and for + +some accuracy, it's +converting. + +Everything is perfect, +except for what? + +It's the wrong answer. + +The moral here, is that just +because an answer is + +statistically valid, does not +mean it's the right answer. + +And that's really important to +understand, because you see + +this, and we'll see more +examples later, not today, but + +after Thanksgiving, comes +up all the time in the + +newspapers, in scientific +articles, where people do a + +million tests, do all the +statistics right, say here's + +the answer, and it turns out +to be completely wrong. + +And that's because it was some +underlying assumption that + +went into the decision, +that was not true. + +So here, the assumption is, +that I've done my algebra + +right for computing pi based +upon where the darts land. + +And it turns out, if I put 2 +here, my algebra is wrong. + +Now how could I discover this? + +Since I've already told you +no statistical test is + +going to help me. + +What's the obvious thing I +should be doing when I get + +this answer? + +Somebody? + +Yeah? + +STUDENT: [INAUDIBLE] + +PROFESSOR: Exactly. + +Checking against reality. + +I started with the notion that +pi had some relation to the + +area of a circle. + +So I could use this value +of pi, draw a + +circle with a radius. + +Do my best to measure +the area. + +I wouldn't need to get a very +good, accurate measurement, + +and I would say, whoa, this +isn't even close. + +And that would tell me +I have a problem. + +So the moral here is, +to check results + +against physical reality. + +So for example, the current +problem set, you're doing a + +simulation about what +happens to viruses + +when drugs are applied. + +If you were doing this for a +pharmaceutical company, in + +addition to the simulation, +you'd want to run some real + +experiments. + +And make sure that +things matched. + +OK, what this suggests, is that +we often use simulation, + +and other computational +techniques, to try and model + +the real world, or the +physical world, in + +which we all live. + +And we can use data +to do that. + +I now want to go through another +set of examples, and + +we're going to look at the +interplay of three things: + +what happens when you have data, +say from measurements, + +and models that at least claim +to explain the data. + +And then, consequences that +follow from the models. + +This is often the way science +works, its the way engineering + +works, we have some +measurements, we have a theory + +that explains the measurements, +and then we + +write software to explore the +consequences of that theory. + +Including, is it plausible +that it's really true? + +So I want to start, as +an example, with a + +classic chosen from 8.01. + +So I presume, everyone +here has taken 8.01? + +Or in 8.01? + +Anyone here who's not had +an experience with 801? + +All right, well. + +I hope you know about springs, +because we're going to talk + +about springs. + +So if you think about it, I'm +now just talking not about + +springs that have water in them, +but springs that you + +compress, you know, and expand, +and things like that. + +And there's typically something +called the spring + +constant that tells us how stiff +the spring is, how much + +energy it takes to compress +this spring. + +Or equivalently, how much pop +the spring has when you're no + +longer holding it down. + +Some springs are easy to +stretch, they have a small + +spring constant. + +Some strings, for example, +the ones that hold up an + +automobile, suspension, +are much harder + +to stretch and compress. + +There's a theory about them +called Hooke's Law. + +And it's quite simple. + +Force, the amount of force +exerted by a spring, is equal + +to minus some constant times +the distance you have + +compressed the spring. + +It's minus, because the force +is exerted in an opposite + +direction, trying +to spring up. + +So for example, we could +look at it this way. + +We've got a spring, excuse +my art here. + +And we put some weight on the +spring, which has therefore + +compressed it a little bit. + +And the spring is exerting +some upward force. + +And the amount of force it's +exerting is proportional to + +the distance x. + +So, if we believe Hooke's Law, +and I give you a spring, how + +can we find out what +this constant is? + +Well, we can do it by putting a +weight on top of the spring. + +It will compress the spring a +certain amount, and then the + +spring will stop moving. + +Now gravity would normally have +had this weight go all + +the way down to the bottom, +if there was no spring. + +So clearly the spring is +exerting some force in the + +upward direction, to keep that +mass from going down to the + +table, right? + +So we know what that +force is there. + +If we compress the spring to a +bunch of different distances, + +by putting, say, different size +weights on it, we can + +then solve for the spring +constant, just the way, + +before, we solved for pi. + +So it just so happens, not quite +by accident, that I've + +got some data from a spring. + +So let's look at it. + +So here's some data taken +from measuring a spring. + +This is distance and force, +force computed from the mass, + +basically, right? + +Because we know that these +have to be in balance. + +And I'm not going to ask you to +in your head estimate the + +constant from these, but what +you'll see is, the format is, + +there's a distance, and then a +colon, and then the force. + +Yeah? + +STUDENT: [INAUDIBLE] + +PROFESSOR: Ok, right, +yes, thank you. + +All right, want to repeat that +more loudly for everyone? + +STUDENT: [INAUDIBLE] + +PROFESSOR: Right, right, because +the x in the equation + +-- right, here we're getting +an equilibrium. + +OK, so let's look at what +happens when we try and + +examine this. + +We'll look at spring dot pi. + +So it's pretty simple. + +First thing is, I've got a +function that reads in the + +data and parses it. + +You've all done more complicated +parsing of data + +files than this. + +So I won't belabor +the details. + +I called it get data rather than +get spring data, because + +I'm going to use the same +thing for a lot of + +other kinds of data. + +And the only thing I want you +to notice, is that it's + +returning a pair of arrays. + +OK, not lists. + +The usual thing is, I'm building +them up using lists, + +because lists have append and +arrays don't, and then I'm + +converting them to arrays so +I can do matrix kinds of + +operations on them. + +So I'll get the distances +and the forces. + +And then I'm just going to plot +them, and we'll see what + +they look like. + +So let's do that. + +There they are. + +Now, if you believe Hooke's Law, +you could look at this + +data, and maybe you +wouldn't like it. + +Because Hooke's Law implies +that, in fact, these points + +should lie in a straight +line, right? + +If I just plug in values here, +what am I going to get? + +A straight line, right? + +I'm just multiplying +k times x. + +But I don't have a straight +line, I have a little scatter + +of points, kind of it looks +like a straight + +line, but it's not. + +And why do you think +that's true? + +What's going on here? + +What could cause this line +not to be straight? + +Have any you ever done +a physics experiment? + +And when you did it, did your +results actually match the + +theory that your high +school teacher, say, + +explained to you. + +No, and why not. + +Yeah, you have various kinds of +experimental or measurement + +error, right? + +Because, when you're doing these +experiments, at least + +I'm not perfect, and I suspect +at least most of you are not + +perfect, you get mistakes. + +A little bit of error creeps +in inevitably. + +And so, when we acquired this +data, sure enough there was + +measurement error. + +And so the points are +scattered around. + +This is something +to be expected. + +Real data almost never matches +the theory precisely. + +Because there usually is some +sort of experimental error + +that creeps into things. + +So what should we +do about that? + +Well, what usually people do, +when they think about this, is + +they would look at this data +and say, well, let me fit a + +line to this. + +Somehow, say, what would +be the line that best + +approximates these points? + +And then the slope of +that line would give + +me the spring constant. + +So that raises the next +question, what do I mean by + +finding a line that best +fits these points? + +How do we, fit, in this case, +a line, to the data? + +First of all, I should ask the +question, why did I say let's + +fit a line? + +Maybe I should have said, let's +fit a parabola, or let's + +fit a circle? + +Why should I had said +let's fit a line. + +Yeah? + +STUDENT: [INAUDIBLE] + +PROFESSOR: Well, how +do I know that the + +plot is a linear function? + +Pardon? + +Well, so, two things. + +One is, I had a theory. + +You know, I had up there a +model, and my model suggested + +that I expected it +to be linear. + +And so if I'm testing my model, +I should and fit a + +line, my theory, if you will. + +But also when I look at it, it +looks kind of like a line. + +So you know, if I looked at it, +and it didn't look like a + +line, I might have said, well, +my model must be badly broken. + +So let's try and see +if we can fit it. + +Whenever we try and fit +something, we need some sort + +of an objective function +that captures the + +goodness of a fit. + +I'm trying to find, this is an +optimization problem of the + +sort that we've looked +at before. + +I'm trying to find a +line that optimizes + +some objective function. + +So a very simple objective +function here, is called the + +least squares fit. + +I want to find the line that +minimizes the sum of + +observation sub i, the i'th data +point I have, minus what + +the line, the model, predicts +that point should have been, + +and then I'll square it. + +So I want to minimize +this value. + +I want to find the line +that gives me the + +smallest value for this. + +Why do you think I'm squaring +the difference? + +What would happen if I didn't +square the difference? + +Yeah? + +Positive and negative errors +might cancel each other out. + +And in judging the quality of +the fit, I don't really care + +deeply -- you're going to get +very fat the way you're + +collecting candy here -- + +I don't care deeply whether the +error is, which side, it + +is, just that it's wrong. + +And so by squaring it, it's +kind of like taking the + +absolute value of the error, +among other things. + +All right, so if we look +at our example here, + +what would this be? + +I want to minimize, want to find +a line that minimizes it. + +So how do I do that? + +I could easily do it +using successive + +approximation, right? + +I could choose a line, basically +what I am, is I'm + +choosing a slope, here, right? + +And, I could, just like Newton +Raphson, do successive + +approximation for awhile, +and get the best fit. + +That's one way to do +the optimization. + +It turns out that for this +particular optimization + +there's something +more efficient. + +You can actually, there is a +closed form way of attacking + +this, and I could explain +that, but in fact, I'll + +explain something even better. + +It's built into Pylab. + +So Pylab has a function built-in +called polyfit. + +Which, given a set of points, +finds the polynomial that + +gives you the best +least squares + +approximation to those points. + +It's called polynomial because +it isn't necessarily going to + +be first order, that +is to say, a line. + +It can find polynomials +of arbitrary degree. + +So let's look at the example +here, we'll see how it works. + +So let me uncomment it. + +So I'm going to get k and b +equals Pylab dot polyfit here. + +What it's going to do is, think +about a polynomial. + +I give you a polynomial of +degree one, you have all + +learned that it's a x plus b, +b is the constant, and x is + +the single variable. + +And so I multiply a by x and I +add b to it, and as I vary x I + +get new values. + +And so polyfit, in this case, +will take the set of points + +defined by these two arrays and +return me a value for a + +and a value for b. + +Now here I've assigned a to k, +but don't worry about that. + +And then, I'm gonna now generate +the predictions that + +I would get from this k +and b, and plot those. + +So let's look at it. + +So here it said the k is 31.475, +etc., and it's plotted + +the line that it's found. + +Or I've plotted the line. + +You'll note, a lot of the points +don't lie on the line, + +in fact, most of the points +don't lie on the line. + +But it's asserting that +this is the best it + +can do with the line. + +And there's some points, for +example, up here, that are + +kind of outliers, that are +pretty far from the line. + +But it has minimized the error, +if you will, for all of + +the points it has. + +That's quite different from, +say, finding the line that + +touches the most +points, right? + +It's minimizing the +sum of the errors. + +Now, given that I was just +looking for a constant to + +start with, why did I bother +even plotting the data? + +I happen to have known before +I did this that polyfit + +existed, and what I was really +looking for was this line. + +So maybe I should have just +done the polyfit and said + +here's k and I'm done. + +Would that have been +a good idea? + +Yeah? + +STUDENT: You can't know without +seeing the actual data + +how well it's actually +fitting it. + +PROFESSOR: Right. + +Exactly right. + +That says, well how would I know +that it was fitting it + +badly or well, and in fact, +how would I know that my + +notion of the model is sound, +or that my experiment isn't + +completely broken? + +So always, I think, always +look at the real data. + +Don't just, I've seen too many +papers where people show me + +the curve that fits the data, +and don't show me the data, + +and it always makes +me very nervous. + +So always look at the data, +as well as however you're + +choosing to fit it. + +As an example of that, let's +look at another set of inputs. + +This is not a spring. + +It's the same get data function +as before, ignore + +that thing at the top. + +I'm going to analyze it +and we'll look at it. + +So here I'm plotting the speed +of something over time. + +So I plotted it, and I've done +a least squares fit using + +polyfit just as before to get a +line, and I put the line vs. + +the data, and here I'm +a little suspicious. + +Right, I fit a line, but when +I look at it, I don't think + +it's a real good fit +for the data. + +Somehow modeling this data as a +line is probably not right. + +A linear model is not +good for this data. + +This data is derived +from something, a + +more complex process. + +So take a look at it, and tell +me what order were calling of + +polynomial do you think +might fit this data? + +What shape does this +look like to you? + +Pardon? + +STUDENT: Quadratic. + +PROFESSOR: Quadratic, because +the shape is a what? + +It's a parabola. + +Well, I don't know if I +dare try this one all + +the way to the back. + +Ooh, at least I didn't +hurt anybody. + +All right, fortunately it's just +as easy to fit a ravel + +parabola as a line. + +So let's look down here. + +I've done the same thing, but +instead of passing it one, as + +I did up here as the argument, +I'm passing it two. + +Saying, instead of fitting a +polynomial of degree one, fit + +a polynomial of degree two. + +And now let's see what +it looks like. + +Well, my eyes tell me this +is a much better + +fit than the line. + +So again, that's why I wanted +to see the scatter plot, so + +that I could at least look at +it with my eyes, and say, + +yeah, this looks like +a better fit. + +All right, any question about +what's going on here? + +What we've been looking at is +something called linear + +regression. + +It's called linear because the +relationship of the dependent + +variable y to the independent +variables is assumed to be a + +linear function of +the parameters. + +It's not because it has to +be a linear function of + +the value of x, OK? + +Because as you can see, we're +not getting a line, we're + +getting a parabola. + +Don't worry about the details, +the point I want to make is, + +people sometimes see the word +linear regression and think it + +can only be used +to find lines. + +It's not so. + +So when, for example, we did the +quadratic, what we had is + +y equals a x squared +plus b x plus c. + +The graph vs. x will not be a +straight line, right, because + +I'm squaring x. + +But it is, just about, in this +case, the single variable x. + +Now, when I looked at this, I +said, all right, it's clear + +that the yellow curve is a +better fit than the red. + +It's a red line. + +But that was a pretty +informal statement. + +I can actually look at this +much more formally. + +And we're going to look at +something that's the + +statisticians call r squared. + +Which in the case of a linear +regression is the coefficient + +of determination. + +Now, this is a big fancy word +for something that's actually + +pretty simple. + +So what r squared its going +to be, and this is on your + +handout, is 1 minus e e over d +v. So e e is going to be the + +errors in the estimation. + +So I've got some estimated +values, some predicted values, + +if you will, given to me by the +model, either the line or + +the parabola in this case. + +And I've got some real values, +corresponding to each of those + +points, and I can look at the +difference between the 2 And + +that will tell me how much +difference there is between + +the estimated data and the, +well, between the predicted + +data and the measured +data, in this case. + +And then I want to divide that +by the variance in the + +measured data. + +The data variance. + +How broadly scattered the +measured points are. + +And I'll do that by comparing +the mean of the measured data, + +to the measured data. + +So I get the average value of +the measured data, and I look + +at how different the points +I measure are. + +So I just want to give to you, +informally, because I really + +don't care if you understand +all the math. + +What I do want you to +understand, when someone tells + +you, here's the r squared value, +is, informally what it + +really is saying. + +It's attempting to capture the +proportion of the response + +variation explained by the +variables in the model. + +In this case, x. + +So you'll have some amount of +variation that is explained by + +changing the values +of the variables. + +So if, actually, I'm going to +give an example and then come + +back to it more informally. + +So if, for example, r squared +were to equal 0.9, that would + +mean that approximately 90 +percent of the variation in + +the variables can be explained +by the model. + +OK, so we have some amount of +variation in the measured + +data, and if r squared is 0.9, +it says that 90 percent can be + +explained by the models, and the +other 10 percent cannot. + +Now, that other 10 percent could +be experimental error, + +or it could be that, in +fact, you need more + +variables in the model. + +That there are what are called +lurking variables. + +I love this term. + +A lurking variable is something +that actually + +effects the result, but is not +reflected in the model. + +As we'll see a little bit +later, this is a very + +important thing to worry about, +when you're looking at + +experimental data and you're +building models. + +So we see this, for example, +in the medical literature, + +that they will do some +experiment, and they'll say + +that this drug explains +x, or has this affect. + +And the variables they are +looking at are, say, the + +disease the patient has, and +the age of the patient. + +Well, maybe the gender of the +patient is also important, but + +it doesn't happen to +be in the model. + +Now, if when they did a fit, +it came out with 0.9, that + +says at worst case, the +variables we didn't consider + +could cause a 10 +percent error. + +But, that could be big, that +could matter a lot. + +And so as you get farther from +1, you ought to get very + +worried about whether +you actually have + +all the right variables. + +Now you might have the right +variables, and just experiment + +was not conducted well, But it's +usually the case that the + +problem is not that, but that +there are lurking variables. + +And we'll see examples +of that. + +So, easier to read than the +math, at least by me, easier + +to read than the math, is the +implementation of r square. + +So it's measured and estimated +values, I get the diffs, the + +differences, between the +estimated and the measured. + +These are both arrays, so I +subtract 1 array from the + +other, and then I square it. + +Remember, this'll do an +element-wise subtraction, and + +then square each element. + +Then I can get the mean, by +dividing the sum of the array + +measured by the length of it. + +I can get the variance, which is +the measured mean minus the + +measured value, again squared. + +And then I'll return +1 minus this. + +All right? + +So, just to make sure we sort +of understand the code, and + +the theory here as well, what +would we get if we had + +absolutely perfect prediction? + +So if every measured point +actually fit on the curb + +predicted by our model, what +would r square return? + +So in this case, measured and +estimated would be identical. + +What gets return by this? + +Yeah, 1. + +Exactly right. + +Because when I compute it, it +will turn out that these two + +numbers will be the, I'll get +0, 1 minus 0 is 0, right? + +Because the differences +will be zero. + +OK? + +So I can use this, now, to +actually get a notion of how + +good my fit is. + +So let's look at speed dot pi +again here, and now I'm going + +to uncomment these two things, +where I'm going to, after I + +compute the fit, I'm going +to then measure it. + +And you'll see here that the r +squared error for the linear + +fit is 0.896, and for the +quadratic fit is 0.973. + +So indeed, we get a much +better fit here. + +So not only does our eye tell +us we have a better fit, our + +more formal statistical measure +tells us we have a + +better fit, and it tells +us how good it is. + +It's not a perfect fit, +but it's a pretty + +good fit, for sure. + +Now, interestingly enough, it +isn't surprising that the + +quadratic fit is better +than the linear fit. + +In fact, the mathematics of +this should tell us it can + +never be worse. + +How do I know it can +never be worse? + +That's just, never is a +really strong word. + +How do I know that? + +Because, when I do the quadratic +fit, if I had + +perfectly linear data, then this +coefficient, whoops, not + +that coefficient, wrong, this +coefficient, could be 0. + +So if I ask it to do a quadratic +fit to linear data, + +and the a is truly perfectly +linear, this coefficient will + +be 0, and my model will turn +out to be the same as the + +linear model. + +So I will always get at +least as good a fit. + +Now, does this mean that it's +always better to use a higher + +order polynomial? + +The answer is no, and +let's look at why. + +So here what I've done is, I've +taken seven points, and + +I've generated, if you look at +this line here, the y-values, + +for x in x vals, points +dot append x + +plus some random number. + +So basically I've got something +linear in x, but I'm + +perturbing, if you will, my +data by some random value. + +Something between 0 and 1 is +getting added to things. + +And I'm doing this so my +points won't lie on a + +perfectly straight line. + +And then we'll try and +fit a line to it. + +And also, just for fun, we'll +try and fit a fifth order + +polynomial to it. + +And let's see what we get. + +Well, there's my line, and +there's my fifth order + +polynomial. + +Neither is quite perfect, but +which do you think looks like + +a closer fit? + +With your eye. + +Well, I would say the red line, +the red curve, if you + +will, is a better fit, and sure +enough if we look at the + +statistics, we'll see it's 0.99, +as opposed to 0.978. + +So it's clearly a closer fit. + +But that raises the very +important question: does + +closer equal better, or tighter, +which is another word + +for closer? + +And the answer is no. + +It's a tighter fit, but it's not +necessarily better, in the + +sense of more useful. + +Because one of the things I +want to do when I build a + +model like this, is +have something + +with predictive power. + +I don't really necessarily need +a model to tell me where + +the points I've measured lie, +because I have them. + +The whole purpose of the model +is to give me some way to + +predict where unmeasured points +would lie, where future + +points would lie. + +OK, I understand how the spring +works, and I can guess + +where it would be if things +I haven't had the time to + +measure, or the ability +to measure. + +So let's look at that. + +Let's see, where'd +that figure go. + +It's lurking somewhere. + +All right, we'll just +kill this for now. + +So let's generate some more +points, and I'm going to use + +exactly the same algorithm. + +But I'm going to generate +twice as many points. + +But I'm only fitting it +to the first half. + +So if I run this one, +figure one is what + +we looked at before. + +The red line is fitting +them a little better. + +But here's figure two. + +What happens when I extrapolate +the curve to the + +new points? + +Well, you can see, it's +a terrible fit. + +And you would expect that, +because my data was basically + +linear, and I fit in non-linear +curve to it. + +And if you look at it you can +see that, OK, look at this, to + +get from here to here, it +thought I had to take off + +pretty sharply. + +And so sure enough, as I get +new points, the prediction + +will postulate that it's still +going up, much more steeply + +than it really does. + +So you can see it's a +terrible prediction. + +And that's because what I've +done is, I over-fit the data. + +I've taken a very high degree +polynomial, which has given me + +a good close fit, and I can +always get a fit, by the way. + +If I choose a high enough degree +polynomial, I can fit + +lots and lots of data sets. + +But I have reason to +be very suspicious. + +The fact that I took a fifth +order polynomial to get six + +points should make +me very nervous. + +And it's a very important +moral. + +Beware of over-fitting. + +If you have a very complex +model, there's a good chance + +that it's over-fit. + +The larger moral is, beware of +statistics without any theory. + +You're just cranking away, you +get a great r squared, you say + +it's a beautiful fit. + +But there was no real +theory there. + +You can always find a fit. + +As Disraeli is alleged to have +said, there are three kinds of + +lies: lies, damned lies, +and statistics. + +And we'll spend some more time +when we get back from + +Thanksgiving looking at how +to lie with statistics. + +Have a great holiday, +everybody. \ No newline at end of file diff --git a/UCc9q_cAhho.txt b/UCc9q_cAhho.txt new file mode 100644 index 0000000000000000000000000000000000000000..c2fd1f6cc544e4884563911a8dab9f4b9836a7c2 --- /dev/null +++ b/UCc9q_cAhho.txt @@ -0,0 +1,5595 @@ +align:start position:0% + +one and the lecture on symmetric + + align:start position:0% +one and the lecture on symmetric + + + align:start position:0% +one and the lecture on symmetric +matrices so that's the most important + + align:start position:0% +matrices so that's the most important + + + align:start position:0% +matrices so that's the most important +class of matrices symmetric matrices a + + align:start position:0% +class of matrices symmetric matrices a + + + align:start position:0% +class of matrices symmetric matrices a +equals a transpose so the first points + + align:start position:0% +equals a transpose so the first points + + + align:start position:0% +equals a transpose so the first points +the main points of the lecture I'll tell + + align:start position:0% +the main points of the lecture I'll tell + + + align:start position:0% +the main points of the lecture I'll tell +you right away what's special about the + + align:start position:0% +you right away what's special about the + + + align:start position:0% +you right away what's special about the +eigenvalues what's special about the + + align:start position:0% +eigenvalues what's special about the + + + align:start position:0% +eigenvalues what's special about the +eigenvectors this is now that this is + + align:start position:0% +eigenvectors this is now that this is + + + align:start position:0% +eigenvectors this is now that this is +the way we now look at a matrix we want + + align:start position:0% +the way we now look at a matrix we want + + + align:start position:0% +the way we now look at a matrix we want +to know about its eigenvalues and + + align:start position:0% +to know about its eigenvalues and + + + align:start position:0% +to know about its eigenvalues and +eigenvectors and if we have a special + + align:start position:0% +eigenvectors and if we have a special + + + align:start position:0% +eigenvectors and if we have a special +type of matrix that should tell us + + align:start position:0% +type of matrix that should tell us + + + align:start position:0% +type of matrix that should tell us +something about eigenvalues and + + align:start position:0% +something about eigenvalues and + + + align:start position:0% +something about eigenvalues and +eigenvectors like markov matrices they + + align:start position:0% +eigenvectors like markov matrices they + + + align:start position:0% +eigenvectors like markov matrices they +have an eigenvalue equal 1 now symmetric + + align:start position:0% +have an eigenvalue equal 1 now symmetric + + + align:start position:0% +have an eigenvalue equal 1 now symmetric +matrices can I just tell you right off + + align:start position:0% +matrices can I just tell you right off + + + align:start position:0% +matrices can I just tell you right off +what the main facts the two main facts + + align:start position:0% +what the main facts the two main facts + + + align:start position:0% +what the main facts the two main facts +are the eigenvalues of a symmetric + + align:start position:0% +are the eigenvalues of a symmetric + + + align:start position:0% +are the eigenvalues of a symmetric +matrix real this is a real symmetric + + align:start position:0% +matrix real this is a real symmetric + + + align:start position:0% +matrix real this is a real symmetric +matrix we're talking mostly about real + + align:start position:0% +matrix we're talking mostly about real + + + align:start position:0% +matrix we're talking mostly about real +matrices the eigen values are also real + + align:start position:0% + + + + align:start position:0% + +so our examples of rotation matrices + + align:start position:0% +so our examples of rotation matrices + + + align:start position:0% +so our examples of rotation matrices +where where we got I can values that + + align:start position:0% +where where we got I can values that + + + align:start position:0% +where where we got I can values that +were complex that won't happen now for a + + align:start position:0% +were complex that won't happen now for a + + + align:start position:0% +were complex that won't happen now for a +symmetric matrices the eigen values are + + align:start position:0% +symmetric matrices the eigen values are + + + align:start position:0% +symmetric matrices the eigen values are +real and the eigen vectors are also very + + align:start position:0% +real and the eigen vectors are also very + + + align:start position:0% +real and the eigen vectors are also very +special the eigen vectors are + + align:start position:0% +special the eigen vectors are + + + align:start position:0% +special the eigen vectors are +perpendicular orthogonal so which do you + + align:start position:0% +perpendicular orthogonal so which do you + + + align:start position:0% +perpendicular orthogonal so which do you +prefer I'll say perpendicular perp well + + align:start position:0% +prefer I'll say perpendicular perp well + + + align:start position:0% +prefer I'll say perpendicular perp well +they're both long words perp and dick + + align:start position:0% + + + + align:start position:0% + +okay right so I you should say why and + + align:start position:0% +okay right so I you should say why and + + + align:start position:0% +okay right so I you should say why and +I'll at least answer why for case one + + align:start position:0% +I'll at least answer why for case one + + + align:start position:0% +I'll at least answer why for case one +maybe case to the checking the eigen + + align:start position:0% +maybe case to the checking the eigen + + + align:start position:0% +maybe case to the checking the eigen +that the eigen vectors are perpendicular + + align:start position:0% +that the eigen vectors are perpendicular + + + align:start position:0% +that the eigen vectors are perpendicular +I'll leave to the book but let's just + + align:start position:0% +I'll leave to the book but let's just + + + align:start position:0% +I'll leave to the book but let's just +realize what well first I have to say it + + align:start position:0% +realize what well first I have to say it + + + align:start position:0% +realize what well first I have to say it +it could happen like for the identity + + align:start position:0% +it could happen like for the identity + + + align:start position:0% +it could happen like for the identity +matrix there's a symmetric matrix its + + align:start position:0% +matrix there's a symmetric matrix its + + + align:start position:0% +matrix there's a symmetric matrix its +eigenvalues are certainly all real + + align:start position:0% +eigenvalues are certainly all real + + + align:start position:0% +eigenvalues are certainly all real +they're all one for the identity matrix + + align:start position:0% +they're all one for the identity matrix + + + align:start position:0% +they're all one for the identity matrix +what about the eigenvectors well for the + + align:start position:0% +what about the eigenvectors well for the + + + align:start position:0% +what about the eigenvectors well for the +identity every vector is an eigenvector + + align:start position:0% +identity every vector is an eigenvector + + + align:start position:0% +identity every vector is an eigenvector +so how can i say they're perpendicular + + align:start position:0% +so how can i say they're perpendicular + + + align:start position:0% +so how can i say they're perpendicular +what I really mean is the this word are + + align:start position:0% +what I really mean is the this word are + + + align:start position:0% +what I really mean is the this word are +should really be written can be chosen + + align:start position:0% + + + + align:start position:0% + +perpendicular that is if we have it's + + align:start position:0% +perpendicular that is if we have it's + + + align:start position:0% +perpendicular that is if we have it's +the usual case if the eigenvalues are + + align:start position:0% +the usual case if the eigenvalues are + + + align:start position:0% +the usual case if the eigenvalues are +all different then each eigenvalue as + + align:start position:0% +all different then each eigenvalue as + + + align:start position:0% +all different then each eigenvalue as +one line of eigenvectors and those lines + + align:start position:0% +one line of eigenvectors and those lines + + + align:start position:0% +one line of eigenvectors and those lines +are perpendicular here but if an + + align:start position:0% +are perpendicular here but if an + + + align:start position:0% +are perpendicular here but if an +eigenvalue is repeated then there's a + + align:start position:0% +eigenvalue is repeated then there's a + + + align:start position:0% +eigenvalue is repeated then there's a +whole plane of eigenvectors and all I'm + + align:start position:0% +whole plane of eigenvectors and all I'm + + + align:start position:0% +whole plane of eigenvectors and all I'm +saying is that in that plane we can + + align:start position:0% +saying is that in that plane we can + + + align:start position:0% +saying is that in that plane we can +choose perpendicular ones so that's why + + align:start position:0% +choose perpendicular ones so that's why + + + align:start position:0% +choose perpendicular ones so that's why +it's a can be chosen part if this is in + + align:start position:0% +it's a can be chosen part if this is in + + + align:start position:0% +it's a can be chosen part if this is in +the case of a repeated eigenvalue where + + align:start position:0% +the case of a repeated eigenvalue where + + + align:start position:0% +the case of a repeated eigenvalue where +there's some real substantial freedom + + align:start position:0% +there's some real substantial freedom + + + align:start position:0% +there's some real substantial freedom +but the typical case is different + + align:start position:0% +but the typical case is different + + + align:start position:0% +but the typical case is different +eigenvalues all real one-dimensional + + align:start position:0% +eigenvalues all real one-dimensional + + + align:start position:0% +eigenvalues all real one-dimensional +eigen vector spaces eigenspaces and all + + align:start position:0% +eigen vector spaces eigenspaces and all + + + align:start position:0% +eigen vector spaces eigenspaces and all +perpendicular so just let's just see the + + align:start position:0% +perpendicular so just let's just see the + + + align:start position:0% +perpendicular so just let's just see the +conclusion if we accept those as correct + + align:start position:0% +conclusion if we accept those as correct + + + align:start position:0% +conclusion if we accept those as correct +what happens and i also mean that + + align:start position:0% +what happens and i also mean that + + + align:start position:0% +what happens and i also mean that +there's a full set of them i + + align:start position:0% + + + + align:start position:0% + +so that's part of this picture here that + + align:start position:0% +so that's part of this picture here that + + + align:start position:0% +so that's part of this picture here that +there's a complete set of eigenvectors + + align:start position:0% +there's a complete set of eigenvectors + + + align:start position:0% +there's a complete set of eigenvectors +perpendicular ones so having a complete + + align:start position:0% +perpendicular ones so having a complete + + + align:start position:0% +perpendicular ones so having a complete +set of eigenvectors means so normal so + + align:start position:0% +set of eigenvectors means so normal so + + + align:start position:0% +set of eigenvectors means so normal so +the usual maybe I put the usually usual + + align:start position:0% +the usual maybe I put the usually usual + + + align:start position:0% +the usual maybe I put the usually usual +usual case is that the matrix a we can + + align:start position:0% +usual case is that the matrix a we can + + + align:start position:0% +usual case is that the matrix a we can +write in terms of its eigen value matrix + + align:start position:0% +write in terms of its eigen value matrix + + + align:start position:0% +write in terms of its eigen value matrix +and its eigenvector matrix this way + + align:start position:0% +and its eigenvector matrix this way + + + align:start position:0% +and its eigenvector matrix this way +right we can do that in the usual case + + align:start position:0% +right we can do that in the usual case + + + align:start position:0% +right we can do that in the usual case +but now what's special when the matrix + + align:start position:0% +but now what's special when the matrix + + + align:start position:0% +but now what's special when the matrix +is symmetric so this is the usual case + + align:start position:0% +is symmetric so this is the usual case + + + align:start position:0% +is symmetric so this is the usual case +and now let me go to the symmetric case + + align:start position:0% + + + + align:start position:0% + +so in the symmetric case a this this + + align:start position:0% +so in the symmetric case a this this + + + align:start position:0% +so in the symmetric case a this this +should become somehow a little special + + align:start position:0% +should become somehow a little special + + + align:start position:0% +should become somehow a little special +well the lambdas on the diagonal are + + align:start position:0% +well the lambdas on the diagonal are + + + align:start position:0% +well the lambdas on the diagonal are +still on the diagonal there they're real + + align:start position:0% +still on the diagonal there they're real + + + align:start position:0% +still on the diagonal there they're real +but that's where they are what about the + + align:start position:0% +but that's where they are what about the + + + align:start position:0% +but that's where they are what about the +eigenvector matrix so what can I do now + + align:start position:0% +eigenvector matrix so what can I do now + + + align:start position:0% +eigenvector matrix so what can I do now +special about the eigenvector matrix + + align:start position:0% +special about the eigenvector matrix + + + align:start position:0% +special about the eigenvector matrix +when when the a itself is symmetric that + + align:start position:0% +when when the a itself is symmetric that + + + align:start position:0% +when when the a itself is symmetric that +says something good about the + + align:start position:0% +says something good about the + + + align:start position:0% +says something good about the +eigenvector matrix so what is this what + + align:start position:0% +eigenvector matrix so what is this what + + + align:start position:0% +eigenvector matrix so what is this what +does this lead to this these + + align:start position:0% +does this lead to this these + + + align:start position:0% +does this lead to this these +perpendicular eigenvectors I can only I + + align:start position:0% +perpendicular eigenvectors I can only I + + + align:start position:0% +perpendicular eigenvectors I can only I +can not only guarantee they're + + align:start position:0% +can not only guarantee they're + + + align:start position:0% +can not only guarantee they're +perpendicular I could also make them + + align:start position:0% +perpendicular I could also make them + + + align:start position:0% +perpendicular I could also make them +unit vectors no problem just scale their + + align:start position:0% +unit vectors no problem just scale their + + + align:start position:0% +unit vectors no problem just scale their +lengths to one so what do I have I have + + align:start position:0% +lengths to one so what do I have I have + + + align:start position:0% +lengths to one so what do I have I have +orthonormal eigenvectors and what does + + align:start position:0% +orthonormal eigenvectors and what does + + + align:start position:0% +orthonormal eigenvectors and what does +that tell me about the eigenvector + + align:start position:0% +that tell me about the eigenvector + + + align:start position:0% +that tell me about the eigenvector +matrix what what letter should I now use + + align:start position:0% +matrix what what letter should I now use + + + align:start position:0% +matrix what what letter should I now use +in place of s remember s has the + + align:start position:0% +in place of s remember s has the + + + align:start position:0% +in place of s remember s has the +eigenvectors in its columns but now + + align:start position:0% +eigenvectors in its columns but now + + + align:start position:0% +eigenvectors in its columns but now +those columns are orthonormal so the + + align:start position:0% +those columns are orthonormal so the + + + align:start position:0% +those columns are orthonormal so the +right letter to use is q so that's where + + align:start position:0% +right letter to use is q so that's where + + + align:start position:0% +right letter to use is q so that's where +so we've got the letter all set up so + + align:start position:0% +so we've got the letter all set up so + + + align:start position:0% +so we've got the letter all set up so +this should + + align:start position:0% +this should + + + align:start position:0% +this should +Q lambda Q inverse Q standing in our + + align:start position:0% +Q lambda Q inverse Q standing in our + + + align:start position:0% +Q lambda Q inverse Q standing in our +minds always for this matrix in this + + align:start position:0% +minds always for this matrix in this + + + align:start position:0% +minds always for this matrix in this +case its square its its so these are the + + align:start position:0% +case its square its its so these are the + + + align:start position:0% +case its square its its so these are the +columns of Q of course and one more + + align:start position:0% +columns of Q of course and one more + + + align:start position:0% +columns of Q of course and one more +thing what's Q inverse for an + + align:start position:0% +thing what's Q inverse for an + + + align:start position:0% +thing what's Q inverse for an +orthonormal for a matrix that has these + + align:start position:0% +orthonormal for a matrix that has these + + + align:start position:0% +orthonormal for a matrix that has these +orthonormal columns we know that the + + align:start position:0% +orthonormal columns we know that the + + + align:start position:0% +orthonormal columns we know that the +inverse is the same as the transpose so + + align:start position:0% +inverse is the same as the transpose so + + + align:start position:0% +inverse is the same as the transpose so +here is the beautiful there's the the + + align:start position:0% +here is the beautiful there's the the + + + align:start position:0% +here is the beautiful there's the the +great description the factorization of a + + align:start position:0% +great description the factorization of a + + + align:start position:0% +great description the factorization of a +symmetric matrix and this is like one of + + align:start position:0% +symmetric matrix and this is like one of + + + align:start position:0% +symmetric matrix and this is like one of +the famous theorems of linear algebra + + align:start position:0% +the famous theorems of linear algebra + + + align:start position:0% +the famous theorems of linear algebra +that if I have a symmetric matrix it can + + align:start position:0% +that if I have a symmetric matrix it can + + + align:start position:0% +that if I have a symmetric matrix it can +be factored in this form an orthogonal + + align:start position:0% +be factored in this form an orthogonal + + + align:start position:0% +be factored in this form an orthogonal +matrix times diagonal times the + + align:start position:0% +matrix times diagonal times the + + + align:start position:0% +matrix times diagonal times the +transpose of that orthogonal matrix and + + align:start position:0% +transpose of that orthogonal matrix and + + + align:start position:0% +transpose of that orthogonal matrix and +of course everybody immediately says yes + + align:start position:0% +of course everybody immediately says yes + + + align:start position:0% +of course everybody immediately says yes +and if this is possible then that's + + align:start position:0% +and if this is possible then that's + + + align:start position:0% +and if this is possible then that's +clearly symmetric right that take we've + + align:start position:0% +clearly symmetric right that take we've + + + align:start position:0% +clearly symmetric right that take we've +looked at products of three guys like + + align:start position:0% +looked at products of three guys like + + + align:start position:0% +looked at products of three guys like +that and taken their transpose and we + + align:start position:0% +that and taken their transpose and we + + + align:start position:0% +that and taken their transpose and we +got it back again so do you see the + + align:start position:0% +got it back again so do you see the + + + align:start position:0% +got it back again so do you see the +beauty of this of this factorization + + align:start position:0% +beauty of this of this factorization + + + align:start position:0% +beauty of this of this factorization +then it completely displays the + + align:start position:0% +then it completely displays the + + + align:start position:0% +then it completely displays the +eigenvalues and eigenvectors and the + + align:start position:0% +eigenvalues and eigenvectors and the + + + align:start position:0% +eigenvalues and eigenvectors and the +symmetry of the of the whole thing + + align:start position:0% +symmetry of the of the whole thing + + + align:start position:0% +symmetry of the of the whole thing +because that product q times lambda + + align:start position:0% +because that product q times lambda + + + align:start position:0% +because that product q times lambda +times q transpose if I transpose it it + + align:start position:0% +times q transpose if I transpose it it + + + align:start position:0% +times q transpose if I transpose it it +just comes in this position and we get + + align:start position:0% +just comes in this position and we get + + + align:start position:0% +just comes in this position and we get +that matrix back again so that's in + + align:start position:0% +that matrix back again so that's in + + + align:start position:0% +that matrix back again so that's in +mathematics that's called the spectral + + align:start position:0% +mathematics that's called the spectral + + + align:start position:0% +mathematics that's called the spectral +theorem spectrum is the set of + + align:start position:0% +theorem spectrum is the set of + + + align:start position:0% +theorem spectrum is the set of +eigenvalues of a matrix spec + + align:start position:0% +eigenvalues of a matrix spec + + + align:start position:0% +eigenvalues of a matrix spec +it somehow comes from the idea of the + + align:start position:0% +it somehow comes from the idea of the + + + align:start position:0% +it somehow comes from the idea of the +spectrum of light as a combination of + + align:start position:0% +spectrum of light as a combination of + + + align:start position:0% +spectrum of light as a combination of +pure things where our matrix is broken + + align:start position:0% +pure things where our matrix is broken + + + align:start position:0% +pure things where our matrix is broken +down into pure eigenvalues and + + align:start position:0% +down into pure eigenvalues and + + + align:start position:0% +down into pure eigenvalues and +eigenvectors + + align:start position:0% +eigenvectors + + + align:start position:0% +eigenvectors +in mechanic's it's often called the + + align:start position:0% +in mechanic's it's often called the + + + align:start position:0% +in mechanic's it's often called the +principal axis theorem it's very useful + + align:start position:0% +principal axis theorem it's very useful + + + align:start position:0% +principal axis theorem it's very useful +it means that if you have we'll see it + + align:start position:0% +it means that if you have we'll see it + + + align:start position:0% +it means that if you have we'll see it +geometrically it means that if I have + + align:start position:0% +geometrically it means that if I have + + + align:start position:0% +geometrically it means that if I have +some material if I look at the right + + align:start position:0% +some material if I look at the right + + + align:start position:0% +some material if I look at the right +axes it becomes diagonal it becomes the + + align:start position:0% +axes it becomes diagonal it becomes the + + + align:start position:0% +axes it becomes diagonal it becomes the +the directions don't couple together + + align:start position:0% +the directions don't couple together + + + align:start position:0% +the directions don't couple together +okay so that's that's what to remember + + align:start position:0% +okay so that's that's what to remember + + + align:start position:0% +okay so that's that's what to remember +from this lecture now I would like to + + align:start position:0% +from this lecture now I would like to + + + align:start position:0% +from this lecture now I would like to +say why are the eigenvalues real can I + + align:start position:0% +say why are the eigenvalues real can I + + + align:start position:0% +say why are the eigenvalues real can I +do that + + align:start position:0% +do that + + + align:start position:0% +do that +so because something useful comes out so + + align:start position:0% +so because something useful comes out so + + + align:start position:0% +so because something useful comes out so +I'll just come back come to that + + align:start position:0% +I'll just come back come to that + + + align:start position:0% +I'll just come back come to that +question why real eigenvalues okay so I + + align:start position:0% +question why real eigenvalues okay so I + + + align:start position:0% +question why real eigenvalues okay so I +have to start from the only thing we + + align:start position:0% +have to start from the only thing we + + + align:start position:0% +have to start from the only thing we +know ax equal lambda X okay but as far + + align:start position:0% +know ax equal lambda X okay but as far + + + align:start position:0% +know ax equal lambda X okay but as far +as I know at this moment lambda could be + + align:start position:0% +as I know at this moment lambda could be + + + align:start position:0% +as I know at this moment lambda could be +complex I'm going to prove it's not and + + align:start position:0% +complex I'm going to prove it's not and + + + align:start position:0% +complex I'm going to prove it's not and +X could be complex in fact for the + + align:start position:0% +X could be complex in fact for the + + + align:start position:0% +X could be complex in fact for the +moment even a could be we could even + + align:start position:0% +moment even a could be we could even + + + align:start position:0% +moment even a could be we could even +think well what happens if a is complex + + align:start position:0% +think well what happens if a is complex + + + align:start position:0% +think well what happens if a is complex +well one thing we can always do this is + + align:start position:0% +well one thing we can always do this is + + + align:start position:0% +well one thing we can always do this is +this is like always always okay I can if + + align:start position:0% +this is like always always okay I can if + + + align:start position:0% +this is like always always okay I can if +I have an equation I can take the + + align:start position:0% +I have an equation I can take the + + + align:start position:0% +I have an equation I can take the +complex conjugate of everything that's + + align:start position:0% +complex conjugate of everything that's + + + align:start position:0% +complex conjugate of everything that's +no so a conjugate X conjugate equal + + align:start position:0% +no so a conjugate X conjugate equal + + + align:start position:0% +no so a conjugate X conjugate equal +lambda conjugate X conjugate it just + + align:start position:0% +lambda conjugate X conjugate it just + + + align:start position:0% +lambda conjugate X conjugate it just +means that everywhere over here that + + align:start position:0% +means that everywhere over here that + + + align:start position:0% +means that everywhere over here that +there was a an I then here I changed it + + align:start position:0% +there was a an I then here I changed it + + + align:start position:0% +there was a an I then here I changed it +to a minus I that that you know that + + align:start position:0% +to a minus I that that you know that + + + align:start position:0% +to a minus I that that you know that +that step that conjugate business that a + + align:start position:0% +that step that conjugate business that a + + + align:start position:0% +that step that conjugate business that a +plus IB if I conjugated it's a minus IB + + align:start position:0% +plus IB if I conjugated it's a minus IB + + + align:start position:0% +plus IB if I conjugated it's a minus IB +that's the meaning of conjugate and + + align:start position:0% +that's the meaning of conjugate and + + + align:start position:0% +that's the meaning of conjugate and +products behave right I can conjugate + + align:start position:0% +products behave right I can conjugate + + + align:start position:0% +products behave right I can conjugate +every factor so I haven't done anything + + align:start position:0% +every factor so I haven't done anything + + + align:start position:0% +every factor so I haven't done anything +yet except to say what + + align:start position:0% +yet except to say what + + + align:start position:0% +yet except to say what +would be true if X in any case even if X + + align:start position:0% +would be true if X in any case even if X + + + align:start position:0% +would be true if X in any case even if X +and lambda were complex of course our + + align:start position:0% +and lambda were complex of course our + + + align:start position:0% +and lambda were complex of course our +and we're speaking about real matrices a + + align:start position:0% +and we're speaking about real matrices a + + + align:start position:0% +and we're speaking about real matrices a +so I can take that out actually this + + align:start position:0% +so I can take that out actually this + + + align:start position:0% +so I can take that out actually this +already tells me something about real + + align:start position:0% +already tells me something about real + + + align:start position:0% +already tells me something about real +matrices I haven't used any assumption + + align:start position:0% +matrices I haven't used any assumption + + + align:start position:0% +matrices I haven't used any assumption +of a equal a transpose yet symmetry is + + align:start position:0% +of a equal a transpose yet symmetry is + + + align:start position:0% +of a equal a transpose yet symmetry is +waiting in the wings to be used this + + align:start position:0% +waiting in the wings to be used this + + + align:start position:0% +waiting in the wings to be used this +tells me that if a real matrix has an + + align:start position:0% +tells me that if a real matrix has an + + + align:start position:0% +tells me that if a real matrix has an +eigenvalue lambda and an eigenvector x + + align:start position:0% +eigenvalue lambda and an eigenvector x + + + align:start position:0% +eigenvalue lambda and an eigenvector x +it also has another of its eigenvalues + + align:start position:0% +it also has another of its eigenvalues + + + align:start position:0% +it also has another of its eigenvalues +is lambda bar with eigenvector x bar + + align:start position:0% +is lambda bar with eigenvector x bar + + + align:start position:0% +is lambda bar with eigenvector x bar +real matrices the eigen values come in + + align:start position:0% +real matrices the eigen values come in + + + align:start position:0% +real matrices the eigen values come in +lambda lambda bar the complex + + align:start position:0% +lambda lambda bar the complex + + + align:start position:0% +lambda lambda bar the complex +eigenvalues come in lambda and lambda + + align:start position:0% +eigenvalues come in lambda and lambda + + + align:start position:0% +eigenvalues come in lambda and lambda +bar pairs but of course I'm aiming to + + align:start position:0% +bar pairs but of course I'm aiming to + + + align:start position:0% +bar pairs but of course I'm aiming to +show that they're not complex at all + + align:start position:0% +show that they're not complex at all + + + align:start position:0% +show that they're not complex at all +here by getting symmetry in so how am I + + align:start position:0% +here by getting symmetry in so how am I + + + align:start position:0% +here by getting symmetry in so how am I +going to use symmetry I'm going to + + align:start position:0% +going to use symmetry I'm going to + + + align:start position:0% +going to use symmetry I'm going to +transpose this equation to X bar + + align:start position:0% +transpose this equation to X bar + + + align:start position:0% +transpose this equation to X bar +transpose a transpose equals X bar + + align:start position:0% +transpose a transpose equals X bar + + + align:start position:0% +transpose a transpose equals X bar +transpose lambda bar that's just a + + align:start position:0% +transpose lambda bar that's just a + + + align:start position:0% +transpose lambda bar that's just a +number so I don't mind where I put that + + align:start position:0% +number so I don't mind where I put that + + + align:start position:0% +number so I don't mind where I put that +number this is this is then again okay + + align:start position:0% +number this is this is then again okay + + + align:start position:0% +number this is this is then again okay +but now I'm ready to use symmetry I'm + + align:start position:0% +but now I'm ready to use symmetry I'm + + + align:start position:0% +but now I'm ready to use symmetry I'm +ready so this was all just mechanics now + + align:start position:0% +ready so this was all just mechanics now + + + align:start position:0% +ready so this was all just mechanics now +now comes the moment to say okay if the + + align:start position:0% +now comes the moment to say okay if the + + + align:start position:0% +now comes the moment to say okay if the +matrix is symmetric then this a + + align:start position:0% +matrix is symmetric then this a + + + align:start position:0% +matrix is symmetric then this a +transpose is the same as a you see at + + align:start position:0% +transpose is the same as a you see at + + + align:start position:0% +transpose is the same as a you see at +that moment I use the assumption now let + + align:start position:0% +that moment I use the assumption now let + + + align:start position:0% +that moment I use the assumption now let +me finish the discussion here's the way + + align:start position:0% +me finish the discussion here's the way + + + align:start position:0% +me finish the discussion here's the way +I finish I look at this original + + align:start position:0% +I finish I look at this original + + + align:start position:0% +I finish I look at this original +equation and I take the inner product I + + align:start position:0% +equation and I take the inner product I + + + align:start position:0% +equation and I take the inner product I +multiply both sides by oh maybe I'll do + + align:start position:0% +multiply both sides by oh maybe I'll do + + + align:start position:0% +multiply both sides by oh maybe I'll do +it with this one I take I multiply both + + align:start position:0% +it with this one I take I multiply both + + + align:start position:0% +it with this one I take I multiply both +sides by X bar transpose X bar transpose + + align:start position:0% +sides by X bar transpose X bar transpose + + + align:start position:0% +sides by X bar transpose X bar transpose +a + + align:start position:0% +a + + + align:start position:0% +a +spar equals lambda bar X bar transpose X + + align:start position:0% +spar equals lambda bar X bar transpose X + + + align:start position:0% +spar equals lambda bar X bar transpose X +bar okay fine all right now what's the + + align:start position:0% +bar okay fine all right now what's the + + + align:start position:0% +bar okay fine all right now what's the +other one oh the other one I'll probably + + align:start position:0% +other one oh the other one I'll probably + + + align:start position:0% +other one oh the other one I'll probably +use this guy am i happy about this no + + align:start position:0% +use this guy am i happy about this no + + + align:start position:0% +use this guy am i happy about this no +for some reason I'm not I'm I want to + + align:start position:0% +for some reason I'm not I'm I want to + + + align:start position:0% +for some reason I'm not I'm I want to +yeah if I take the inner product of this + + align:start position:0% +yeah if I take the inner product of this + + + align:start position:0% +yeah if I take the inner product of this +from the right with X bar I get X bar + + align:start position:0% +from the right with X bar I get X bar + + + align:start position:0% +from the right with X bar I get X bar +transpose a X bar equals x bar transpose + + align:start position:0% +transpose a X bar equals x bar transpose + + + align:start position:0% +transpose a X bar equals x bar transpose +lambda bar X bar I've done something + + align:start position:0% +lambda bar X bar I've done something + + + align:start position:0% +lambda bar X bar I've done something +dumb because I've got the I haven't + + align:start position:0% +dumb because I've got the I haven't + + + align:start position:0% +dumb because I've got the I haven't +learned anything I've got those two + + align:start position:0% +learned anything I've got those two + + + align:start position:0% +learned anything I've got those two +equations are identical so forgive me + + align:start position:0% +equations are identical so forgive me + + + align:start position:0% +equations are identical so forgive me +for doing such a thing + + align:start position:0% +for doing such a thing + + + align:start position:0% +for doing such a thing +but a look at the book okay so I took + + align:start position:0% +but a look at the book okay so I took + + + align:start position:0% +but a look at the book okay so I took +the dot product yeah somehow it didn't I + + align:start position:0% +the dot product yeah somehow it didn't I + + + align:start position:0% +the dot product yeah somehow it didn't I +should have taken the dot product of + + align:start position:0% +should have taken the dot product of + + + align:start position:0% +should have taken the dot product of +this guy here with that's what I was + + align:start position:0% +this guy here with that's what I was + + + align:start position:0% +this guy here with that's what I was +gonna do a x equals lambda X bar + + align:start position:0% +gonna do a x equals lambda X bar + + + align:start position:0% +gonna do a x equals lambda X bar +transpose X right okay so that that was + + align:start position:0% +transpose X right okay so that that was + + + align:start position:0% +transpose X right okay so that that was +that's fine that comes directly from + + align:start position:0% +that's fine that comes directly from + + + align:start position:0% +that's fine that comes directly from +that multiplying both sides by X bar + + align:start position:0% +that multiplying both sides by X bar + + + align:start position:0% +that multiplying both sides by X bar +transpose but now I'd like to get why do + + align:start position:0% +transpose but now I'd like to get why do + + + align:start position:0% +transpose but now I'd like to get why do +I have X bars over there oh yes forget + + align:start position:0% +I have X bars over there oh yes forget + + + align:start position:0% +I have X bars over there oh yes forget +this okay on this one right on this one + + align:start position:0% +this okay on this one right on this one + + + align:start position:0% +this okay on this one right on this one +I took it like that I multiply on the + + align:start position:0% +I took it like that I multiply on the + + + align:start position:0% +I took it like that I multiply on the +right by X that's the idea okay now why + + align:start position:0% +right by X that's the idea okay now why + + + align:start position:0% +right by X that's the idea okay now why +am i happier with this situation now the + + align:start position:0% +am i happier with this situation now the + + + align:start position:0% +am i happier with this situation now the +proof is coming here because I compare + + align:start position:0% +proof is coming here because I compare + + + align:start position:0% +proof is coming here because I compare +this guy + + align:start position:0% +this guy + + + align:start position:0% +this guy +with this one and they have the same + + align:start position:0% +with this one and they have the same + + + align:start position:0% +with this one and they have the same +left-hand side so they have the same + + align:start position:0% +left-hand side so they have the same + + + align:start position:0% +left-hand side so they have the same +right-hand side so comparing those two + + align:start position:0% +right-hand side so comparing those two + + + align:start position:0% +right-hand side so comparing those two +can I'll raise the board to do this + + align:start position:0% +can I'll raise the board to do this + + + align:start position:0% +can I'll raise the board to do this +comparison this thing lambda X bar + + align:start position:0% +comparison this thing lambda X bar + + + align:start position:0% +comparison this thing lambda X bar +transpose X is equal to lambda bar X bar + + align:start position:0% +transpose X is equal to lambda bar X bar + + + align:start position:0% +transpose X is equal to lambda bar X bar +transpose X okay and the conclusion I'm + + align:start position:0% +transpose X okay and the conclusion I'm + + + align:start position:0% +transpose X okay and the conclusion I'm +going to reach am I am I on the right + + align:start position:0% +going to reach am I am I on the right + + + align:start position:0% +going to reach am I am I on the right +track here the conclusion I'm going to + + align:start position:0% +track here the conclusion I'm going to + + + align:start position:0% +track here the conclusion I'm going to +reach is lambda equal lambda bar I would + + align:start position:0% +reach is lambda equal lambda bar I would + + + align:start position:0% +reach is lambda equal lambda bar I would +have to track down the other possibility + + align:start position:0% +have to track down the other possibility + + + align:start position:0% +have to track down the other possibility +that this this thing is zero but let me + + align:start position:0% +that this this thing is zero but let me + + + align:start position:0% +that this this thing is zero but let me +oh oh yeah that's important it's not + + align:start position:0% +oh oh yeah that's important it's not + + + align:start position:0% +oh oh yeah that's important it's not +zero so once I know that this isn't zero + + align:start position:0% +zero so once I know that this isn't zero + + + align:start position:0% +zero so once I know that this isn't zero +I just cancel it and I learned that + + align:start position:0% +I just cancel it and I learned that + + + align:start position:0% +I just cancel it and I learned that +lambda equals lambda bar and so what can + + align:start position:0% +lambda equals lambda bar and so what can + + + align:start position:0% +lambda equals lambda bar and so what can +you do have you got the reasoning + + align:start position:0% +you do have you got the reasoning + + + align:start position:0% +you do have you got the reasoning +altogether what does this tell us + + align:start position:0% +altogether what does this tell us + + + align:start position:0% +altogether what does this tell us +lambda is an eigenvalue of this + + align:start position:0% +lambda is an eigenvalue of this + + + align:start position:0% +lambda is an eigenvalue of this +symmetric matrix we've just proved that + + align:start position:0% +symmetric matrix we've just proved that + + + align:start position:0% +symmetric matrix we've just proved that +an equaled lambda bar so we have just + + align:start position:0% +an equaled lambda bar so we have just + + + align:start position:0% +an equaled lambda bar so we have just +proved that lambda is real right if if a + + align:start position:0% +proved that lambda is real right if if a + + + align:start position:0% +proved that lambda is real right if if a +number is equal to its own complex + + align:start position:0% +number is equal to its own complex + + + align:start position:0% +number is equal to its own complex +conjugate then there's no imaginary part + + align:start position:0% +conjugate then there's no imaginary part + + + align:start position:0% +conjugate then there's no imaginary part +at all the number is real so lambda is + + align:start position:0% +at all the number is real so lambda is + + + align:start position:0% +at all the number is real so lambda is +real good good + + align:start position:0% +real good good + + + align:start position:0% +real good good +now what but it depended on this little + + align:start position:0% +now what but it depended on this little + + + align:start position:0% +now what but it depended on this little +expression on knowing that that wasn't + + align:start position:0% +expression on knowing that that wasn't + + + align:start position:0% +expression on knowing that that wasn't +zero so that I could cancel it out so + + align:start position:0% +zero so that I could cancel it out so + + + align:start position:0% +zero so that I could cancel it out so +can we just take a second on that one + + align:start position:0% +can we just take a second on that one + + + align:start position:0% +can we just take a second on that one +because it's an important quantity X bar + + align:start position:0% +because it's an important quantity X bar + + + align:start position:0% +because it's an important quantity X bar +transpose X okay now remember as far as + + align:start position:0% +transpose X okay now remember as far as + + + align:start position:0% +transpose X okay now remember as far as +we know X is complex so this is + + align:start position:0% +we know X is complex so this is + + + align:start position:0% +we know X is complex so this is +here X is complex X has these components + + align:start position:0% +here X is complex X has these components + + + align:start position:0% +here X is complex X has these components +X 1 X 2 down 2 X n and X bar transpose + + align:start position:0% +X 1 X 2 down 2 X n and X bar transpose + + + align:start position:0% +X 1 X 2 down 2 X n and X bar transpose +well it's transposed and it's conjugated + + align:start position:0% +well it's transposed and it's conjugated + + + align:start position:0% +well it's transposed and it's conjugated +so that's X 1 conjugated X 2 conjugated + + align:start position:0% +so that's X 1 conjugated X 2 conjugated + + + align:start position:0% +so that's X 1 conjugated X 2 conjugated +up to X and conjugate it I'm really + + align:start position:0% +up to X and conjugate it I'm really + + + align:start position:0% +up to X and conjugate it I'm really +reminding you of crucial facts about + + align:start position:0% +reminding you of crucial facts about + + + align:start position:0% +reminding you of crucial facts about +complex numbers that are going to come + + align:start position:0% +complex numbers that are going to come + + + align:start position:0% +complex numbers that are going to come +into the next lecture as well as this + + align:start position:0% +into the next lecture as well as this + + + align:start position:0% +into the next lecture as well as this +one so what can you tell me about that + + align:start position:0% +one so what can you tell me about that + + + align:start position:0% +one so what can you tell me about that +product I guess what I'm trying to say + + align:start position:0% +product I guess what I'm trying to say + + + align:start position:0% +product I guess what I'm trying to say +is if I had a complex vector this would + + align:start position:0% +is if I had a complex vector this would + + + align:start position:0% +is if I had a complex vector this would +be the quantity I would I would like + + align:start position:0% +be the quantity I would I would like + + + align:start position:0% +be the quantity I would I would like +this is the quantity I like I would take + + align:start position:0% +this is the quantity I like I would take + + + align:start position:0% +this is the quantity I like I would take +the vector times its transpose now what + + align:start position:0% +the vector times its transpose now what + + + align:start position:0% +the vector times its transpose now what +what happens usually if I take a vector + + align:start position:0% +what happens usually if I take a vector + + + align:start position:0% +what happens usually if I take a vector +X transpose X I mean that's a quantity + + align:start position:0% +X transpose X I mean that's a quantity + + + align:start position:0% +X transpose X I mean that's a quantity +we see all the time X transpose X that's + + align:start position:0% +we see all the time X transpose X that's + + + align:start position:0% +we see all the time X transpose X that's +the length of x squared right + + align:start position:0% +the length of x squared right + + + align:start position:0% +the length of x squared right +that's this positive length squared it's + + align:start position:0% +that's this positive length squared it's + + + align:start position:0% +that's this positive length squared it's +Pythagoras it's x1 squared plus x2 + + align:start position:0% +Pythagoras it's x1 squared plus x2 + + + align:start position:0% +Pythagoras it's x1 squared plus x2 +squared and so on + + align:start position:0% +squared and so on + + + align:start position:0% +squared and so on +now our vectors complex and you see the + + align:start position:0% +now our vectors complex and you see the + + + align:start position:0% +now our vectors complex and you see the +effect + + align:start position:0% +effect + + + align:start position:0% +effect +I'm conjugating one of these guys so now + + align:start position:0% +I'm conjugating one of these guys so now + + + align:start position:0% +I'm conjugating one of these guys so now +when I do this multiplication + + align:start position:0% +when I do this multiplication + + + align:start position:0% +when I do this multiplication +I have x1 bar times x1 and x2 bar times + + align:start position:0% +I have x1 bar times x1 and x2 bar times + + + align:start position:0% +I have x1 bar times x1 and x2 bar times +x2 and so on so this is an this is some + + align:start position:0% +x2 and so on so this is an this is some + + + align:start position:0% +x2 and so on so this is an this is some +a plus IB and this is some a minus IB I + + align:start position:0% +a plus IB and this is some a minus IB I + + + align:start position:0% +a plus IB and this is some a minus IB I +mean what's the point here + + align:start position:0% +mean what's the point here + + + align:start position:0% +mean what's the point here +what's the point when I multiply a + + align:start position:0% +what's the point when I multiply a + + + align:start position:0% +what's the point when I multiply a +number by its conjugate a complex number + + align:start position:0% +number by its conjugate a complex number + + + align:start position:0% +number by its conjugate a complex number +by its conjugate what do I get I get up + + align:start position:0% +by its conjugate what do I get I get up + + + align:start position:0% +by its conjugate what do I get I get up +the the imaginary part is gone when I + + align:start position:0% +the the imaginary part is gone when I + + + align:start position:0% +the the imaginary part is gone when I +multiply a plus IB by its conjugate + + align:start position:0% +multiply a plus IB by its conjugate + + + align:start position:0% +multiply a plus IB by its conjugate +what's what's the result of that of each + + align:start position:0% +what's what's the result of that of each + + + align:start position:0% +what's what's the result of that of each +of those separate little multiplications + + align:start position:0% +of those separate little multiplications + + + align:start position:0% +of those separate little multiplications +there's an a squared and and what how + + align:start position:0% +there's an a squared and and what how + + + align:start position:0% +there's an a squared and and what how +many what's B squared it comes in with a + + align:start position:0% +many what's B squared it comes in with a + + + align:start position:0% +many what's B squared it comes in with a +plus or a minus a plus + + align:start position:0% +plus or a minus a plus + + + align:start position:0% +plus or a minus a plus +I times minus I is a plus B squared and + + align:start position:0% +I times minus I is a plus B squared and + + + align:start position:0% +I times minus I is a plus B squared and +what about the imaginary part gone right + + align:start position:0% +what about the imaginary part gone right + + + align:start position:0% +what about the imaginary part gone right +and I a B and a minus I a B so this this + + align:start position:0% +and I a B and a minus I a B so this this + + + align:start position:0% +and I a B and a minus I a B so this this +is the right thing to do if you want a + + align:start position:0% +is the right thing to do if you want a + + + align:start position:0% +is the right thing to do if you want a +decent answer then multiply numbers by + + align:start position:0% +decent answer then multiply numbers by + + + align:start position:0% +decent answer then multiply numbers by +their conjugates multiply vectors by the + + align:start position:0% +their conjugates multiply vectors by the + + + align:start position:0% +their conjugates multiply vectors by the +conjugates of X transpose so this + + align:start position:0% +conjugates of X transpose so this + + + align:start position:0% +conjugates of X transpose so this +quantity is positive this quantity is + + align:start position:0% +quantity is positive this quantity is + + + align:start position:0% +quantity is positive this quantity is +positive the whole thing is positive + + align:start position:0% +positive the whole thing is positive + + + align:start position:0% +positive the whole thing is positive +except for the zero vector and that + + align:start position:0% +except for the zero vector and that + + + align:start position:0% +except for the zero vector and that +allows me to know that this is a + + align:start position:0% +allows me to know that this is a + + + align:start position:0% +allows me to know that this is a +positive number which I safely cancel + + align:start position:0% +positive number which I safely cancel + + + align:start position:0% +positive number which I safely cancel +out and I reach the conclusion so + + align:start position:0% +out and I reach the conclusion so + + + align:start position:0% +out and I reach the conclusion so +actually in this discussion here I've + + align:start position:0% +actually in this discussion here I've + + + align:start position:0% +actually in this discussion here I've +done two things I've reached the + + align:start position:0% +done two things I've reached the + + + align:start position:0% +done two things I've reached the +conclusion that lambdas real which I + + align:start position:0% +conclusion that lambdas real which I + + + align:start position:0% +conclusion that lambdas real which I +wanted to do but at the same time we + + align:start position:0% +wanted to do but at the same time we + + + align:start position:0% +wanted to do but at the same time we +sort of saw what to do if things were + + align:start position:0% +sort of saw what to do if things were + + + align:start position:0% +sort of saw what to do if things were +complex if a vector is complex then it's + + align:start position:0% +complex if a vector is complex then it's + + + align:start position:0% +complex if a vector is complex then it's +X bar transpose X this is its length + + align:start position:0% + + + + align:start position:0% + +squared and as I said the next lecture + + align:start position:0% +squared and as I said the next lecture + + + align:start position:0% +squared and as I said the next lecture +Monday will will repeat that this is the + + align:start position:0% +Monday will will repeat that this is the + + + align:start position:0% +Monday will will repeat that this is the +right thing and then do the right thing + + align:start position:0% +right thing and then do the right thing + + + align:start position:0% +right thing and then do the right thing +for matrices and all other all other + + align:start position:0% +for matrices and all other all other + + + align:start position:0% +for matrices and all other all other +complex possibilities okay but the main + + align:start position:0% +complex possibilities okay but the main + + + align:start position:0% +complex possibilities okay but the main +point then is that the eigenvalues of a + + align:start position:0% +point then is that the eigenvalues of a + + + align:start position:0% +point then is that the eigenvalues of a +symmetric matrix it just where did we + + align:start position:0% +symmetric matrix it just where did we + + + align:start position:0% +symmetric matrix it just where did we +use symmetry by the way we use it here + + align:start position:0% +use symmetry by the way we use it here + + + align:start position:0% +use symmetry by the way we use it here +right + + align:start position:0% +right + + + align:start position:0% +right +can I just suppose a was a complex + + align:start position:0% +can I just suppose a was a complex + + + align:start position:0% +can I just suppose a was a complex +suppose I had been a complex number + + align:start position:0% +suppose I had been a complex number + + + align:start position:0% +suppose I had been a complex number +could could I have made all this work if + + align:start position:0% +could could I have made all this work if + + + align:start position:0% +could could I have made all this work if +a was a complex number but complex + + align:start position:0% +a was a complex number but complex + + + align:start position:0% +a was a complex number but complex +matrix then here I should have written a + + align:start position:0% +matrix then here I should have written a + + + align:start position:0% +matrix then here I should have written a +bar I erased the bar because I assumed a + + align:start position:0% +bar I erased the bar because I assumed a + + + align:start position:0% +bar I erased the bar because I assumed a +was real but now let's + + align:start position:0% +was real but now let's + + + align:start position:0% +was real but now let's +suppose for a moment it's not then when + + align:start position:0% +suppose for a moment it's not then when + + + align:start position:0% +suppose for a moment it's not then when +I took this step what should I have what + + align:start position:0% +I took this step what should I have what + + + align:start position:0% +I took this step what should I have what +did i do on that step I transposed so I + + align:start position:0% +did i do on that step I transposed so I + + + align:start position:0% +did i do on that step I transposed so I +should have a bar transpose in the + + align:start position:0% +should have a bar transpose in the + + + align:start position:0% +should have a bar transpose in the +symmetric case that was a and that's + + align:start position:0% +symmetric case that was a and that's + + + align:start position:0% +symmetric case that was a and that's +what made everything work right this + + align:start position:0% +what made everything work right this + + + align:start position:0% +what made everything work right this +this led immediately to that this one + + align:start position:0% +this led immediately to that this one + + + align:start position:0% +this led immediately to that this one +that immediately to this when the matrix + + align:start position:0% +that immediately to this when the matrix + + + align:start position:0% +that immediately to this when the matrix +was real so that didn't matter + + align:start position:0% +was real so that didn't matter + + + align:start position:0% +was real so that didn't matter +and it was symmetric so that didn't + + align:start position:0% +and it was symmetric so that didn't + + + align:start position:0% +and it was symmetric so that didn't +matter then I got a but so now I just + + align:start position:0% +matter then I got a but so now I just + + + align:start position:0% +matter then I got a but so now I just +get to ask you suppose the matrix had + + align:start position:0% +get to ask you suppose the matrix had + + + align:start position:0% +get to ask you suppose the matrix had +been complex what's the right equivalent + + align:start position:0% +been complex what's the right equivalent + + + align:start position:0% +been complex what's the right equivalent +of symmetry so so so the good matrix so + + align:start position:0% +of symmetry so so so the good matrix so + + + align:start position:0% +of symmetry so so so the good matrix so +here let me say good matrices by good I + + align:start position:0% +here let me say good matrices by good I + + + align:start position:0% +here let me say good matrices by good I +mean real lambdas and perpendicular X's + + align:start position:0% +mean real lambdas and perpendicular X's + + + align:start position:0% +mean real lambdas and perpendicular X's +and tell me now which matrices are good + + align:start position:0% +and tell me now which matrices are good + + + align:start position:0% +and tell me now which matrices are good +if they're submit if they're if they're + + align:start position:0% +if they're submit if they're if they're + + + align:start position:0% +if they're submit if they're if they're +real matrices the good ones are + + align:start position:0% +real matrices the good ones are + + + align:start position:0% +real matrices the good ones are +symmetric because then everything went + + align:start position:0% +symmetric because then everything went + + + align:start position:0% +symmetric because then everything went +through so the so the good the I'm + + align:start position:0% +through so the so the good the I'm + + + align:start position:0% +through so the so the good the I'm +saying now what's good this is this is + + align:start position:0% +saying now what's good this is this is + + + align:start position:0% +saying now what's good this is this is +these are the good matrices they have + + align:start position:0% +these are the good matrices they have + + + align:start position:0% +these are the good matrices they have +real eigenvalues perpendicular + + align:start position:0% +real eigenvalues perpendicular + + + align:start position:0% +real eigenvalues perpendicular +eigenvectors good means a equal a + + align:start position:0% +eigenvectors good means a equal a + + + align:start position:0% +eigenvectors good means a equal a +transpose if real then then that was + + align:start position:0% +transpose if real then then that was + + + align:start position:0% +transpose if real then then that was +what our proof worked but if a is + + align:start position:0% +what our proof worked but if a is + + + align:start position:0% +what our proof worked but if a is +complex all our proof will still work + + align:start position:0% +complex all our proof will still work + + + align:start position:0% +complex all our proof will still work +provided a bar transpose is a do you see + + align:start position:0% +provided a bar transpose is a do you see + + + align:start position:0% +provided a bar transpose is a do you see +that I'm saying + + align:start position:0% +that I'm saying + + + align:start position:0% +that I'm saying +I'm saying if we have complex matrices + + align:start position:0% +I'm saying if we have complex matrices + + + align:start position:0% +I'm saying if we have complex matrices +and we want to say are they are they as + + align:start position:0% +and we want to say are they are they as + + + align:start position:0% +and we want to say are they are they as +good as symmetric matrices then we + + align:start position:0% +good as symmetric matrices then we + + + align:start position:0% +good as symmetric matrices then we +should not only transpose the thing but + + align:start position:0% +should not only transpose the thing but + + + align:start position:0% +should not only transpose the thing but +conjugate it + + align:start position:0% +conjugate it + + + align:start position:0% +conjugate it +those are good matrices and of course + + align:start position:0% +those are good matrices and of course + + + align:start position:0% +those are good matrices and of course +the most + + align:start position:0% +the most + + + align:start position:0% +the most +importance the most important case is + + align:start position:0% +importance the most important case is + + + align:start position:0% +importance the most important case is +when they're real this part doesn't + + align:start position:0% +when they're real this part doesn't + + + align:start position:0% +when they're real this part doesn't +matter and I just have a equal a + + align:start position:0% +matter and I just have a equal a + + + align:start position:0% +matter and I just have a equal a +transpose symmetric I'll just repeat + + align:start position:0% +transpose symmetric I'll just repeat + + + align:start position:0% +transpose symmetric I'll just repeat +that the good matrices if complex are + + align:start position:0% +that the good matrices if complex are + + + align:start position:0% +that the good matrices if complex are +these if real that doesn't make any + + align:start position:0% +these if real that doesn't make any + + + align:start position:0% +these if real that doesn't make any +difference so I'm just saying symmetric + + align:start position:0% +difference so I'm just saying symmetric + + + align:start position:0% +difference so I'm just saying symmetric +and of course 99% of examples and + + align:start position:0% +and of course 99% of examples and + + + align:start position:0% +and of course 99% of examples and +applications the matrices are real and + + align:start position:0% +applications the matrices are real and + + + align:start position:0% +applications the matrices are real and +we don't have that and then symmetric is + + align:start position:0% +we don't have that and then symmetric is + + + align:start position:0% +we don't have that and then symmetric is +the key property ok so that that's these + + align:start position:0% +the key property ok so that that's these + + + align:start position:0% +the key property ok so that that's these +main facts and now let me just let me + + align:start position:0% +main facts and now let me just let me + + + align:start position:0% +main facts and now let me just let me +just so that's this X bar transpose X ok + + align:start position:0% +just so that's this X bar transpose X ok + + + align:start position:0% +just so that's this X bar transpose X ok +so I'll just write it once more in this + + align:start position:0% +so I'll just write it once more in this + + + align:start position:0% +so I'll just write it once more in this +form so perpendicular orthonormal + + align:start position:0% +form so perpendicular orthonormal + + + align:start position:0% +form so perpendicular orthonormal +eigenvectors real eigenvalues transposes + + align:start position:0% +eigenvectors real eigenvalues transposes + + + align:start position:0% +eigenvectors real eigenvalues transposes +of orthonormal eigenvectors + + align:start position:0% +of orthonormal eigenvectors + + + align:start position:0% +of orthonormal eigenvectors +that's the symmetric case a equal a + + align:start position:0% +that's the symmetric case a equal a + + + align:start position:0% +that's the symmetric case a equal a +transpose oh good + + align:start position:0% + + + + align:start position:0% + +actually I'll even take one more step + + align:start position:0% +actually I'll even take one more step + + + align:start position:0% +actually I'll even take one more step +here suppose I can break this down to + + align:start position:0% +here suppose I can break this down to + + + align:start position:0% +here suppose I can break this down to +show you really what that says about a + + align:start position:0% +show you really what that says about a + + + align:start position:0% +show you really what that says about a +symmetric matrix I can break that down + + align:start position:0% +symmetric matrix I can break that down + + + align:start position:0% +symmetric matrix I can break that down +let me here go these eigenvectors i here + + align:start position:0% +let me here go these eigenvectors i here + + + align:start position:0% +let me here go these eigenvectors i here +go these eigenvalues lambda 1 lambda 2 + + align:start position:0% +go these eigenvalues lambda 1 lambda 2 + + + align:start position:0% +go these eigenvalues lambda 1 lambda 2 +and so on here go these eigenvectors + + align:start position:0% +and so on here go these eigenvectors + + + align:start position:0% +and so on here go these eigenvectors +transposed and what happens if i + + align:start position:0% +transposed and what happens if i + + + align:start position:0% +transposed and what happens if i +actually do out that multiplication do + + align:start position:0% +actually do out that multiplication do + + + align:start position:0% +actually do out that multiplication do +you see what will happen + + align:start position:0% +you see what will happen + + + align:start position:0% +you see what will happen +there's lambda 1 times q1 transpose so + + align:start position:0% +there's lambda 1 times q1 transpose so + + + align:start position:0% +there's lambda 1 times q1 transpose so +the first row here is just lambda 1 Q 1 + + align:start position:0% +the first row here is just lambda 1 Q 1 + + + align:start position:0% +the first row here is just lambda 1 Q 1 +transpose if I multiply column times row + + align:start position:0% +transpose if I multiply column times row + + + align:start position:0% +transpose if I multiply column times row +you remember I could do + + align:start position:0% +you remember I could do + + + align:start position:0% +you remember I could do +that when I multiply matrices I can + + align:start position:0% +that when I multiply matrices I can + + + align:start position:0% +that when I multiply matrices I can +multiply columns times rows so what I do + + align:start position:0% +multiply columns times rows so what I do + + + align:start position:0% +multiply columns times rows so what I do +that I get lambda 1 and then the column + + align:start position:0% +that I get lambda 1 and then the column + + + align:start position:0% +that I get lambda 1 and then the column +and then the row and then lambda 2 and + + align:start position:0% +and then the row and then lambda 2 and + + + align:start position:0% +and then the row and then lambda 2 and +the column and the row every symmetric + + align:start position:0% +the column and the row every symmetric + + + align:start position:0% +the column and the row every symmetric +matrix breaks up into these pieces so + + align:start position:0% +matrix breaks up into these pieces so + + + align:start position:0% +matrix breaks up into these pieces so +these pieces have real lambdas and they + + align:start position:0% +these pieces have real lambdas and they + + + align:start position:0% +these pieces have real lambdas and they +have these eigen these orthonormal + + align:start position:0% +have these eigen these orthonormal + + + align:start position:0% +have these eigen these orthonormal +eigenvectors and maybe you even could + + align:start position:0% +eigenvectors and maybe you even could + + + align:start position:0% +eigenvectors and maybe you even could +tell me what kind of a matrix have I got + + align:start position:0% +tell me what kind of a matrix have I got + + + align:start position:0% +tell me what kind of a matrix have I got +there suppose I take a unit vector times + + align:start position:0% +there suppose I take a unit vector times + + + align:start position:0% +there suppose I take a unit vector times +its transpose so column times row I'm + + align:start position:0% +its transpose so column times row I'm + + + align:start position:0% +its transpose so column times row I'm +getting a matrix that's a matrix with a + + align:start position:0% +getting a matrix that's a matrix with a + + + align:start position:0% +getting a matrix that's a matrix with a +special old name what's its what kind of + + align:start position:0% +special old name what's its what kind of + + + align:start position:0% +special old name what's its what kind of +a matrix is it we've seen those matrices + + align:start position:0% +a matrix is it we've seen those matrices + + + align:start position:0% +a matrix is it we've seen those matrices +now in Chapter four it's is a a + + align:start position:0% +now in Chapter four it's is a a + + + align:start position:0% +now in Chapter four it's is a a +transpose with a unit vector so I don't + + align:start position:0% +transpose with a unit vector so I don't + + + align:start position:0% +transpose with a unit vector so I don't +have to divide by a transpose a that + + align:start position:0% +have to divide by a transpose a that + + + align:start position:0% +have to divide by a transpose a that +matrix is a projection matrix that's a + + align:start position:0% +matrix is a projection matrix that's a + + + align:start position:0% +matrix is a projection matrix that's a +projection matrix it's symmetric and if + + align:start position:0% +projection matrix it's symmetric and if + + + align:start position:0% +projection matrix it's symmetric and if +I square it there'll be another there be + + align:start position:0% +I square it there'll be another there be + + + align:start position:0% +I square it there'll be another there be +a q1 transpose Q 1 which is 1 so I'll + + align:start position:0% +a q1 transpose Q 1 which is 1 so I'll + + + align:start position:0% +a q1 transpose Q 1 which is 1 so I'll +get that matrix back again every so + + align:start position:0% +get that matrix back again every so + + + align:start position:0% +get that matrix back again every so +every symmetric matrix every symmetric + + align:start position:0% +every symmetric matrix every symmetric + + + align:start position:0% +every symmetric matrix every symmetric +matrix is a combination of mutually + + align:start position:0% +matrix is a combination of mutually + + + align:start position:0% +matrix is a combination of mutually +perpendicular so perpendicular + + align:start position:0% +perpendicular so perpendicular + + + align:start position:0% +perpendicular so perpendicular +projection matrices projection matrices + + align:start position:0% +projection matrices projection matrices + + + align:start position:0% +projection matrices projection matrices +ok that's another way that people like + + align:start position:0% +ok that's another way that people like + + + align:start position:0% +ok that's another way that people like +to think of the spectral theorem that + + align:start position:0% +to think of the spectral theorem that + + + align:start position:0% +to think of the spectral theorem that +every symmetric matrix can be + + align:start position:0% +every symmetric matrix can be + + + align:start position:0% +every symmetric matrix can be +broken up that way that I guess at this + + align:start position:0% +broken up that way that I guess at this + + + align:start position:0% +broken up that way that I guess at this +moment first I haven't done an example I + + align:start position:0% +moment first I haven't done an example I + + + align:start position:0% +moment first I haven't done an example I +could create a symmetric matrix check + + align:start position:0% +could create a symmetric matrix check + + + align:start position:0% +could create a symmetric matrix check +that it's a find its eigenvalues they + + align:start position:0% +that it's a find its eigenvalues they + + + align:start position:0% +that it's a find its eigenvalues they +would come out real find its + + align:start position:0% +would come out real find its + + + align:start position:0% +would come out real find its +eigenvectors they would come out + + align:start position:0% +eigenvectors they would come out + + + align:start position:0% +eigenvectors they would come out +perpendicular and you would see it in + + align:start position:0% +perpendicular and you would see it in + + + align:start position:0% +perpendicular and you would see it in +numbers but maybe I'll leave it here for + + align:start position:0% +numbers but maybe I'll leave it here for + + + align:start position:0% +numbers but maybe I'll leave it here for +the moment in letters oh maybe I will do + + align:start position:0% +the moment in letters oh maybe I will do + + + align:start position:0% +the moment in letters oh maybe I will do +it with numbers for this reason because + + align:start position:0% +it with numbers for this reason because + + + align:start position:0% +it with numbers for this reason because +there's one more remarkable fact can I + + align:start position:0% +there's one more remarkable fact can I + + + align:start position:0% +there's one more remarkable fact can I +just put this further great fact about + + align:start position:0% +just put this further great fact about + + + align:start position:0% +just put this further great fact about +symmetric matrices on the board when I + + align:start position:0% +symmetric matrices on the board when I + + + align:start position:0% +symmetric matrices on the board when I +have symmetric matrices I know their + + align:start position:0% +have symmetric matrices I know their + + + align:start position:0% +have symmetric matrices I know their +eigenvalues are real so then I can get + + align:start position:0% +eigenvalues are real so then I can get + + + align:start position:0% +eigenvalues are real so then I can get +interested in the question are they + + align:start position:0% +interested in the question are they + + + align:start position:0% +interested in the question are they +positive or negative and you remember + + align:start position:0% +positive or negative and you remember + + + align:start position:0% +positive or negative and you remember +why that's important for differential + + align:start position:0% +why that's important for differential + + + align:start position:0% +why that's important for differential +equations that decides between + + align:start position:0% +equations that decides between + + + align:start position:0% +equations that decides between +instability and stability so I'm after I + + align:start position:0% +instability and stability so I'm after I + + + align:start position:0% +instability and stability so I'm after I +know they're real then the next question + + align:start position:0% +know they're real then the next question + + + align:start position:0% +know they're real then the next question +is are they positive are they negative + + align:start position:0% +is are they positive are they negative + + + align:start position:0% +is are they positive are they negative +and I hate to have to compute those + + align:start position:0% +and I hate to have to compute those + + + align:start position:0% +and I hate to have to compute those +eigenvalues to answer that question + + align:start position:0% +eigenvalues to answer that question + + + align:start position:0% +eigenvalues to answer that question +right because computing the eigenvalues + + align:start position:0% +right because computing the eigenvalues + + + align:start position:0% +right because computing the eigenvalues +of a symmetric matrix of order let's say + + align:start position:0% +of a symmetric matrix of order let's say + + + align:start position:0% +of a symmetric matrix of order let's say +50 compute its 50 eigenvalues is a job I + + align:start position:0% +50 compute its 50 eigenvalues is a job I + + + align:start position:0% +50 compute its 50 eigenvalues is a job I +mean by pencil and paper it's a + + align:start position:0% +mean by pencil and paper it's a + + + align:start position:0% +mean by pencil and paper it's a +lifetime's job I mean which and in fact + + align:start position:0% +lifetime's job I mean which and in fact + + + align:start position:0% +lifetime's job I mean which and in fact +a few years ago well say 20 years ago or + + align:start position:0% +a few years ago well say 20 years ago or + + + align:start position:0% +a few years ago well say 20 years ago or +30 nobody really knew how to do it I + + align:start position:0% +30 nobody really knew how to do it I + + + align:start position:0% +30 nobody really knew how to do it I +mean so like science was stuck on this + + align:start position:0% +mean so like science was stuck on this + + + align:start position:0% +mean so like science was stuck on this +problem if you have a matrix of order 50 + + align:start position:0% +problem if you have a matrix of order 50 + + + align:start position:0% +problem if you have a matrix of order 50 +or 100 how do you find its eigenvalues + + align:start position:0% +or 100 how do you find its eigenvalues + + + align:start position:0% +or 100 how do you find its eigenvalues +numerically now I'm just saying because + + align:start position:0% +numerically now I'm just saying because + + + align:start position:0% +numerically now I'm just saying because +pencil and paper is we're going to run + + align:start position:0% +pencil and paper is we're going to run + + + align:start position:0% +pencil and paper is we're going to run +out of time or paper or something before + + align:start position:0% +out of time or paper or something before + + + align:start position:0% +out of time or paper or something before +we get it well and you might think okay + + align:start position:0% +we get it well and you might think okay + + + align:start position:0% +we get it well and you might think okay +get the get get MATLAB + + align:start position:0% +get the get get MATLAB + + + align:start position:0% +get the get get MATLAB +to compute the determinant of lambda + + align:start position:0% +to compute the determinant of lambda + + + align:start position:0% +to compute the determinant of lambda +minus a a a minus lambda I this + + align:start position:0% +minus a a a minus lambda I this + + + align:start position:0% +minus a a a minus lambda I this +polynomial of 50th degree and then find + + align:start position:0% +polynomial of 50th degree and then find + + + align:start position:0% +polynomial of 50th degree and then find +the roots MATLAB will do it but it will + + align:start position:0% +the roots MATLAB will do it but it will + + + align:start position:0% +the roots MATLAB will do it but it will +complain because it's a very bad way to + + align:start position:0% +complain because it's a very bad way to + + + align:start position:0% +complain because it's a very bad way to +find the eigenvalues I'm sorry to be + + align:start position:0% +find the eigenvalues I'm sorry to be + + + align:start position:0% +find the eigenvalues I'm sorry to be +saying this because it's the way I + + align:start position:0% +saying this because it's the way I + + + align:start position:0% +saying this because it's the way I +taught you to do it right I taught you + + align:start position:0% +taught you to do it right I taught you + + + align:start position:0% +taught you to do it right I taught you +to find the eigenvalues by doing that + + align:start position:0% +to find the eigenvalues by doing that + + + align:start position:0% +to find the eigenvalues by doing that +determinant and taking the roots of that + + align:start position:0% +determinant and taking the roots of that + + + align:start position:0% +determinant and taking the roots of that +polynomial but now I'm saying okay I + + align:start position:0% +polynomial but now I'm saying okay I + + + align:start position:0% +polynomial but now I'm saying okay I +really meant that for two by twos and + + align:start position:0% +really meant that for two by twos and + + + align:start position:0% +really meant that for two by twos and +three by threes but I didn't mean you to + + align:start position:0% +three by threes but I didn't mean you to + + + align:start position:0% +three by threes but I didn't mean you to +do it on a 50 by 50 and you're not too + + align:start position:0% +do it on a 50 by 50 and you're not too + + + align:start position:0% +do it on a 50 by 50 and you're not too +unhappy probably because you didn't want + + align:start position:0% +unhappy probably because you didn't want + + + align:start position:0% +unhappy probably because you didn't want +to do it but good because it would be + + align:start position:0% +to do it but good because it would be + + + align:start position:0% +to do it but good because it would be +very unstable way the aunt the 50 + + align:start position:0% +very unstable way the aunt the 50 + + + align:start position:0% +very unstable way the aunt the 50 +answers that would come out would be + + align:start position:0% +answers that would come out would be + + + align:start position:0% +answers that would come out would be +highly unreliable so new ways are are + + align:start position:0% +highly unreliable so new ways are are + + + align:start position:0% +highly unreliable so new ways are are +much better to find those 50 eigenvalues + + align:start position:0% +much better to find those 50 eigenvalues + + + align:start position:0% +much better to find those 50 eigenvalues +that's a that's a part of numerical + + align:start position:0% +that's a that's a part of numerical + + + align:start position:0% +that's a that's a part of numerical +linear algebra but here's the remarkable + + align:start position:0% +linear algebra but here's the remarkable + + + align:start position:0% +linear algebra but here's the remarkable +fact that MATLAB would quite happily + + align:start position:0% +fact that MATLAB would quite happily + + + align:start position:0% +fact that MATLAB would quite happily +find the 50 pivots right now the pivots + + align:start position:0% +find the 50 pivots right now the pivots + + + align:start position:0% +find the 50 pivots right now the pivots +are not the same as the eigenvalues but + + align:start position:0% +are not the same as the eigenvalues but + + + align:start position:0% +are not the same as the eigenvalues but +here's the great thing if if I had a + + align:start position:0% +here's the great thing if if I had a + + + align:start position:0% +here's the great thing if if I had a +real matrix I could find those 50 pivots + + align:start position:0% +real matrix I could find those 50 pivots + + + align:start position:0% +real matrix I could find those 50 pivots +and I could see maybe 28 of them are + + align:start position:0% +and I could see maybe 28 of them are + + + align:start position:0% +and I could see maybe 28 of them are +positive and 22 or negative pivots and I + + align:start position:0% +positive and 22 or negative pivots and I + + + align:start position:0% +positive and 22 or negative pivots and I +can compute those safely and quickly and + + align:start position:0% +can compute those safely and quickly and + + + align:start position:0% +can compute those safely and quickly and +the great fact is that 28 of the + + align:start position:0% +the great fact is that 28 of the + + + align:start position:0% +the great fact is that 28 of the +eigenvalues would be positive and 22 + + align:start position:0% +eigenvalues would be positive and 22 + + + align:start position:0% +eigenvalues would be positive and 22 +would be negative that the signs of the + + align:start position:0% +would be negative that the signs of the + + + align:start position:0% +would be negative that the signs of the +pivots so this is like just I hope you + + align:start position:0% +pivots so this is like just I hope you + + + align:start position:0% +pivots so this is like just I hope you +think this this is kind of a nice thing + + align:start position:0% +think this this is kind of a nice thing + + + align:start position:0% +think this this is kind of a nice thing +that the signs of the pivots for + + align:start position:0% +that the signs of the pivots for + + + align:start position:0% +that the signs of the pivots for +symmetric I'm always talking about + + align:start position:0% +symmetric I'm always talking about + + + align:start position:0% +symmetric I'm always talking about +symmetric matrices so I really like + + align:start position:0% +symmetric matrices so I really like + + + align:start position:0% +symmetric matrices so I really like +trying to convince you that symmetric + + align:start position:0% +trying to convince you that symmetric + + + align:start position:0% +trying to convince you that symmetric +matrices are better than the rest so the + + align:start position:0% +matrices are better than the rest so the + + + align:start position:0% +matrices are better than the rest so the +signs of the pivots are same as + + align:start position:0% + + + + align:start position:0% + +the signs of the eigenvalues the same + + align:start position:0% +the signs of the eigenvalues the same + + + align:start position:0% +the signs of the eigenvalues the same +number the number of pivots greater than + + align:start position:0% +number the number of pivots greater than + + + align:start position:0% +number the number of pivots greater than +zero + + align:start position:0% +zero + + + align:start position:0% +zero +the number of positive pivots is equal + + align:start position:0% +the number of positive pivots is equal + + + align:start position:0% +the number of positive pivots is equal +to the number of positive eigenvalues so + + align:start position:0% +to the number of positive eigenvalues so + + + align:start position:0% +to the number of positive eigenvalues so +that actually is a very useful that + + align:start position:0% +that actually is a very useful that + + + align:start position:0% +that actually is a very useful that +gives you a good start on a decent way + + align:start position:0% +gives you a good start on a decent way + + + align:start position:0% +gives you a good start on a decent way +to compute eigenvalues because you can + + align:start position:0% +to compute eigenvalues because you can + + + align:start position:0% +to compute eigenvalues because you can +narrow them down you can find out how + + align:start position:0% +narrow them down you can find out how + + + align:start position:0% +narrow them down you can find out how +many are positive how many are negative + + align:start position:0% +many are positive how many are negative + + + align:start position:0% +many are positive how many are negative +then you could shift the matrix by seven + + align:start position:0% +then you could shift the matrix by seven + + + align:start position:0% +then you could shift the matrix by seven +times the identity that would shift all + + align:start position:0% +times the identity that would shift all + + + align:start position:0% +times the identity that would shift all +the eigenvalues by seven then you could + + align:start position:0% +the eigenvalues by seven then you could + + + align:start position:0% +the eigenvalues by seven then you could +take the pivots of that matrix and you + + align:start position:0% +take the pivots of that matrix and you + + + align:start position:0% +take the pivots of that matrix and you +would know how many eigen values of the + + align:start position:0% +would know how many eigen values of the + + + align:start position:0% +would know how many eigen values of the +original were above seven and below + + align:start position:0% +original were above seven and below + + + align:start position:0% +original were above seven and below +seven so this this neat little theorem + + align:start position:0% +seven so this this neat little theorem + + + align:start position:0% +seven so this this neat little theorem +that the symmetric matrices have this + + align:start position:0% +that the symmetric matrices have this + + + align:start position:0% +that the symmetric matrices have this +connection between nobody's mixing up in + + align:start position:0% +connection between nobody's mixing up in + + + align:start position:0% +connection between nobody's mixing up in +thinking the pivots are the eigenvalues + + align:start position:0% +thinking the pivots are the eigenvalues + + + align:start position:0% +thinking the pivots are the eigenvalues +I mean the only thing I can think of is + + align:start position:0% +I mean the only thing I can think of is + + + align:start position:0% +I mean the only thing I can think of is +the product of the pivots equals the + + align:start position:0% +the product of the pivots equals the + + + align:start position:0% +the product of the pivots equals the +product of the eigenvalues why is that + + align:start position:0% +product of the eigenvalues why is that + + + align:start position:0% +product of the eigenvalues why is that +so if I asked you for the reason on that + + align:start position:0% +so if I asked you for the reason on that + + + align:start position:0% +so if I asked you for the reason on that +why is the product of the pivots for a + + align:start position:0% +why is the product of the pivots for a + + + align:start position:0% +why is the product of the pivots for a +symmetric matrix the same as the product + + align:start position:0% +symmetric matrix the same as the product + + + align:start position:0% +symmetric matrix the same as the product +of the eigenvalues because they both + + align:start position:0% +of the eigenvalues because they both + + + align:start position:0% +of the eigenvalues because they both +equal the determinant right the product + + align:start position:0% +equal the determinant right the product + + + align:start position:0% +equal the determinant right the product +of the pivots gives the determinant if + + align:start position:0% +of the pivots gives the determinant if + + + align:start position:0% +of the pivots gives the determinant if +no row exchanges the product of the + + align:start position:0% +no row exchanges the product of the + + + align:start position:0% +no row exchanges the product of the +eigenvalues always gives the determinant + + align:start position:0% +eigenvalues always gives the determinant + + + align:start position:0% +eigenvalues always gives the determinant +so so that products but that doesn't + + align:start position:0% +so so that products but that doesn't + + + align:start position:0% +so so that products but that doesn't +tell you anything about the 50 + + align:start position:0% +tell you anything about the 50 + + + align:start position:0% +tell you anything about the 50 +individual ones which this does okay so + + align:start position:0% +individual ones which this does okay so + + + align:start position:0% +individual ones which this does okay so +that's those are essential facts about + + align:start position:0% +that's those are essential facts about + + + align:start position:0% +that's those are essential facts about +symmetric matrices okay now I said in + + align:start position:0% +symmetric matrices okay now I said in + + + align:start position:0% +symmetric matrices okay now I said in +the in the lecture description that I + + align:start position:0% +the in the lecture description that I + + + align:start position:0% +the in the lecture description that I +would take the last minute + + align:start position:0% +would take the last minute + + + align:start position:0% +would take the last minute +to start on positive definite matrices + + align:start position:0% +to start on positive definite matrices + + + align:start position:0% +to start on positive definite matrices +because we're right there where we're + + align:start position:0% +because we're right there where we're + + + align:start position:0% +because we're right there where we're +we're ready to say what's a positive + + align:start position:0% +we're ready to say what's a positive + + + align:start position:0% +we're ready to say what's a positive +definite matrix it's symmetric first of + + align:start position:0% +definite matrix it's symmetric first of + + + align:start position:0% +definite matrix it's symmetric first of +all I always I will mean symmetric so + + align:start position:0% +all I always I will mean symmetric so + + + align:start position:0% +all I always I will mean symmetric so +this is the this is the next section of + + align:start position:0% +this is the this is the next section of + + + align:start position:0% +this is the this is the next section of +the book it's about this if symmetric + + align:start position:0% +the book it's about this if symmetric + + + align:start position:0% +the book it's about this if symmetric +matrices are good which is like the + + align:start position:0% +matrices are good which is like the + + + align:start position:0% +matrices are good which is like the +point of my lecture so far then positive + + align:start position:0% +point of my lecture so far then positive + + + align:start position:0% +point of my lecture so far then positive +definite matrices are a subclass that + + align:start position:0% +definite matrices are a subclass that + + + align:start position:0% +definite matrices are a subclass that +are excellent ok just the greatest oh so + + align:start position:0% +are excellent ok just the greatest oh so + + + align:start position:0% +are excellent ok just the greatest oh so +what are they they're matrices they're + + align:start position:0% +what are they they're matrices they're + + + align:start position:0% +what are they they're matrices they're +symmetric matrices so all their + + align:start position:0% +symmetric matrices so all their + + + align:start position:0% +symmetric matrices so all their +eigenvalues are real you can guess what + + align:start position:0% +eigenvalues are real you can guess what + + + align:start position:0% +eigenvalues are real you can guess what +they are these are symmetric matrices + + align:start position:0% +they are these are symmetric matrices + + + align:start position:0% +they are these are symmetric matrices +with all the eigenvalues are ok tell me + + align:start position:0% +with all the eigenvalues are ok tell me + + + align:start position:0% +with all the eigenvalues are ok tell me +what to write what well it it's hinted + + align:start position:0% +what to write what well it it's hinted + + + align:start position:0% +what to write what well it it's hinted +of course by the name for these things + + align:start position:0% +of course by the name for these things + + + align:start position:0% +of course by the name for these things +all the eigenvalues are positive ok tell + + align:start position:0% +all the eigenvalues are positive ok tell + + + align:start position:0% +all the eigenvalues are positive ok tell +me about the pivots we can check the + + align:start position:0% +me about the pivots we can check the + + + align:start position:0% +me about the pivots we can check the +eigenvalues or we can check the pivots + + align:start position:0% +eigenvalues or we can check the pivots + + + align:start position:0% +eigenvalues or we can check the pivots +all the pivots are what and then I'll + + align:start position:0% +all the pivots are what and then I'll + + + align:start position:0% +all the pivots are what and then I'll +then I'll finally give an example I feel + + align:start position:0% +then I'll finally give an example I feel + + + align:start position:0% +then I'll finally give an example I feel +awful that I have got to this point in + + align:start position:0% +awful that I have got to this point in + + + align:start position:0% +awful that I have got to this point in +the lecture and I haven't given you a + + align:start position:0% +the lecture and I haven't given you a + + + align:start position:0% +the lecture and I haven't given you a +single example so let me give you 1 5 3 + + align:start position:0% +single example so let me give you 1 5 3 + + + align:start position:0% +single example so let me give you 1 5 3 +2 2 at symmetric fine its eigenvalues + + align:start position:0% +2 2 at symmetric fine its eigenvalues + + + align:start position:0% +2 2 at symmetric fine its eigenvalues +are real for sure but more than that + + align:start position:0% +are real for sure but more than that + + + align:start position:0% +are real for sure but more than that +I know the signs of those eigenvalues + + align:start position:0% +I know the signs of those eigenvalues + + + align:start position:0% +I know the signs of those eigenvalues +and also I know the signs of those + + align:start position:0% +and also I know the signs of those + + + align:start position:0% +and also I know the signs of those +pivots so what's the deal with the + + align:start position:0% +pivots so what's the deal with the + + + align:start position:0% +pivots so what's the deal with the +pivots yeah if the eigenvalues are all + + align:start position:0% +pivots yeah if the eigenvalues are all + + + align:start position:0% +pivots yeah if the eigenvalues are all +positive and if this little fact is true + + align:start position:0% +positive and if this little fact is true + + + align:start position:0% +positive and if this little fact is true +that the pivots and eigenvalues have the + + align:start position:0% +that the pivots and eigenvalues have the + + + align:start position:0% +that the pivots and eigenvalues have the +same signs then this must be true all + + align:start position:0% +same signs then this must be true all + + + align:start position:0% +same signs then this must be true all +the pivots are positive and that's the + + align:start position:0% +the pivots are positive and that's the + + + align:start position:0% +the pivots are positive and that's the +good way to test this is the good test + + align:start position:0% +good way to test this is the good test + + + align:start position:0% +good way to test this is the good test +because I could what are the pivots for + + align:start position:0% +because I could what are the pivots for + + + align:start position:0% +because I could what are the pivots for +that matrix the pivots for that matrix + + align:start position:0% +that matrix the pivots for that matrix + + + align:start position:0% +that matrix the pivots for that matrix +are five so pivots are five and what's + + align:start position:0% +are five so pivots are five and what's + + + align:start position:0% +are five so pivots are five and what's +the second pivot have we like notice the + + align:start position:0% +the second pivot have we like notice the + + + align:start position:0% +the second pivot have we like notice the +formula for the second pivot in a matrix + + align:start position:0% + + + + align:start position:0% + +it doesn't necessarily you know it may + + align:start position:0% +it doesn't necessarily you know it may + + + align:start position:0% +it doesn't necessarily you know it may +come out of fraction for sure but what + + align:start position:0% +come out of fraction for sure but what + + + align:start position:0% +come out of fraction for sure but what +is that fraction can you tell me well + + align:start position:0% +is that fraction can you tell me well + + + align:start position:0% +is that fraction can you tell me well +here the product of the pivots is the + + align:start position:0% +here the product of the pivots is the + + + align:start position:0% +here the product of the pivots is the +determinant what's the determinant of + + align:start position:0% +determinant what's the determinant of + + + align:start position:0% +determinant what's the determinant of +this matrix eleven so the second pivot + + align:start position:0% +this matrix eleven so the second pivot + + + align:start position:0% +this matrix eleven so the second pivot +must be eleven over five so that the + + align:start position:0% +must be eleven over five so that the + + + align:start position:0% +must be eleven over five so that the +product is eleven they're both positive + + align:start position:0% +product is eleven they're both positive + + + align:start position:0% +product is eleven they're both positive +then I know that the eigenvalues of that + + align:start position:0% +then I know that the eigenvalues of that + + + align:start position:0% +then I know that the eigenvalues of that +matrix are both positive what are the + + align:start position:0% +matrix are both positive what are the + + + align:start position:0% +matrix are both positive what are the +eigenvalues well I've got to take the + + align:start position:0% +eigenvalues well I've got to take the + + + align:start position:0% +eigenvalues well I've got to take the +roots of you know do I put in a minus + + align:start position:0% +roots of you know do I put in a minus + + + align:start position:0% +roots of you know do I put in a minus +lambda you mentally do this lambda + + align:start position:0% +lambda you mentally do this lambda + + + align:start position:0% +lambda you mentally do this lambda +squared + + align:start position:0% +squared + + + align:start position:0% +squared +- how many lambdas eight right five and + + align:start position:0% +- how many lambdas eight right five and + + + align:start position:0% +- how many lambdas eight right five and +three the trace comes in there plus what + + align:start position:0% +three the trace comes in there plus what + + + align:start position:0% +three the trace comes in there plus what +number comes here they determinant the + + align:start position:0% +number comes here they determinant the + + + align:start position:0% +number comes here they determinant the +eleven so I set that to zero so the + + align:start position:0% +eleven so I set that to zero so the + + + align:start position:0% +eleven so I set that to zero so the +eigenvalues are let's see half of that + + align:start position:0% +eigenvalues are let's see half of that + + + align:start position:0% +eigenvalues are let's see half of that +is four look at that positive number + + align:start position:0% +is four look at that positive number + + + align:start position:0% +is four look at that positive number +plus or minus the square root of 16 + + align:start position:0% +plus or minus the square root of 16 + + + align:start position:0% +plus or minus the square root of 16 +minus eleven I think five the + + align:start position:0% +minus eleven I think five the + + + align:start position:0% +minus eleven I think five the +eigenvalues well + + align:start position:0% +eigenvalues well + + + align:start position:0% +eigenvalues well +- by - they're not so terrible but + + align:start position:0% +- by - they're not so terrible but + + + align:start position:0% +- by - they're not so terrible but +they're not so + + align:start position:0% +they're not so + + + align:start position:0% +they're not so +perfect pivots are really simple and + + align:start position:0% + + + + align:start position:0% + +this is this is the family of matrices + + align:start position:0% +this is this is the family of matrices + + + align:start position:0% +this is this is the family of matrices +that you really want in differential + + align:start position:0% +that you really want in differential + + + align:start position:0% +that you really want in differential +equations because you know the signs of + + align:start position:0% +equations because you know the signs of + + + align:start position:0% +equations because you know the signs of +the eigenvalues so you know the + + align:start position:0% +the eigenvalues so you know the + + + align:start position:0% +the eigenvalues so you know the +stability or not okay there's one other + + align:start position:0% +stability or not okay there's one other + + + align:start position:0% +stability or not okay there's one other +related fact I can pop in here and in + + align:start position:0% +related fact I can pop in here and in + + + align:start position:0% +related fact I can pop in here and in +the time available for positive definite + + align:start position:0% +the time available for positive definite + + + align:start position:0% +the time available for positive definite +matrices the the related fact is to ask + + align:start position:0% +matrices the the related fact is to ask + + + align:start position:0% +matrices the the related fact is to ask +you about determinants so what's the + + align:start position:0% +you about determinants so what's the + + + align:start position:0% +you about determinants so what's the +determinant what can you tell me if I + + align:start position:0% +determinant what can you tell me if I + + + align:start position:0% +determinant what can you tell me if I +remember positive definite means all + + align:start position:0% +remember positive definite means all + + + align:start position:0% +remember positive definite means all +eigenvalues are positive all pivots are + + align:start position:0% +eigenvalues are positive all pivots are + + + align:start position:0% +eigenvalues are positive all pivots are +positive so what can you tell me about + + align:start position:0% +positive so what can you tell me about + + + align:start position:0% +positive so what can you tell me about +the determinant it's positive too but + + align:start position:0% +the determinant it's positive too but + + + align:start position:0% +the determinant it's positive too but +somehow that that's not quite enough + + align:start position:0% +somehow that that's not quite enough + + + align:start position:0% +somehow that that's not quite enough +here's a matrix minus 1 minus 3 what's + + align:start position:0% +here's a matrix minus 1 minus 3 what's + + + align:start position:0% +here's a matrix minus 1 minus 3 what's +the determinant of that guy it's + + align:start position:0% +the determinant of that guy it's + + + align:start position:0% +the determinant of that guy it's +positive right is this a positive + + align:start position:0% +positive right is this a positive + + + align:start position:0% +positive right is this a positive +definite matrix are the pivots what are + + align:start position:0% +definite matrix are the pivots what are + + + align:start position:0% +definite matrix are the pivots what are +the pivots well negative what are the + + align:start position:0% +the pivots well negative what are the + + + align:start position:0% +the pivots well negative what are the +eigenvalues well they're also the same + + align:start position:0% +eigenvalues well they're also the same + + + align:start position:0% +eigenvalues well they're also the same +so somehow I don't just want the + + align:start position:0% +so somehow I don't just want the + + + align:start position:0% +so somehow I don't just want the +determinant of the whole matrix here is + + align:start position:0% +determinant of the whole matrix here is + + + align:start position:0% +determinant of the whole matrix here is +11 that's great + + align:start position:0% +11 that's great + + + align:start position:0% +11 that's great +here the determinate of the whole matrix + + align:start position:0% +here the determinate of the whole matrix + + + align:start position:0% +here the determinate of the whole matrix +is 3 that's positive I also I've got to + + align:start position:0% +is 3 that's positive I also I've got to + + + align:start position:0% +is 3 that's positive I also I've got to +check like little sub determinants say + + align:start position:0% +check like little sub determinants say + + + align:start position:0% +check like little sub determinants say +maybe coming down from the left so the 1 + + align:start position:0% +maybe coming down from the left so the 1 + + + align:start position:0% +maybe coming down from the left so the 1 +by 1 and the 2 by 2 have to be positive + + align:start position:0% +by 1 and the 2 by 2 have to be positive + + + align:start position:0% +by 1 and the 2 by 2 have to be positive +so there that's where I get the all all + + align:start position:0% +so there that's where I get the all all + + + align:start position:0% +so there that's where I get the all all +can I call them sub determinants or see + + align:start position:0% +can I call them sub determinants or see + + + align:start position:0% +can I call them sub determinants or see +I have to I need to make the thing + + align:start position:0% +I have to I need to make the thing + + + align:start position:0% +I have to I need to make the thing +plural I need to test end things not + + align:start position:0% +plural I need to test end things not + + + align:start position:0% +plural I need to test end things not +just the big determine + + align:start position:0% +just the big determine + + + align:start position:0% +just the big determine +all sub determinants are positive then + + align:start position:0% +all sub determinants are positive then + + + align:start position:0% +all sub determinants are positive then +I'm okay then I'm okay this passes the + + align:start position:0% +I'm okay then I'm okay this passes the + + + align:start position:0% +I'm okay then I'm okay this passes the +test five is positive and eleven is + + align:start position:0% +test five is positive and eleven is + + + align:start position:0% +test five is positive and eleven is +positive this fails the test because + + align:start position:0% +positive this fails the test because + + + align:start position:0% +positive this fails the test because +that minus one there is negative and + + align:start position:0% +that minus one there is negative and + + + align:start position:0% +that minus one there is negative and +then the big determinant is positive + + align:start position:0% +then the big determinant is positive + + + align:start position:0% +then the big determinant is positive +three so this these this fact you see + + align:start position:0% +three so this these this fact you see + + + align:start position:0% +three so this these this fact you see +that actually the course like coming + + align:start position:0% +that actually the course like coming + + + align:start position:0% +that actually the course like coming +together and that's really my point now + + align:start position:0% +together and that's really my point now + + + align:start position:0% +together and that's really my point now +in the next in this lecture and + + align:start position:0% +in the next in this lecture and + + + align:start position:0% +in the next in this lecture and +particularly next Wednesday and Friday + + align:start position:0% +particularly next Wednesday and Friday + + + align:start position:0% +particularly next Wednesday and Friday +the course comes together these pivots + + align:start position:0% +the course comes together these pivots + + + align:start position:0% +the course comes together these pivots +that we met in the first week these + + align:start position:0% +that we met in the first week these + + + align:start position:0% +that we met in the first week these +determinants that we met in the middle + + align:start position:0% +determinants that we met in the middle + + + align:start position:0% +determinants that we met in the middle +of the course these eigenvalues that we + + align:start position:0% +of the course these eigenvalues that we + + + align:start position:0% +of the course these eigenvalues that we +met most recently all matrices are + + align:start position:0% +met most recently all matrices are + + + align:start position:0% +met most recently all matrices are +square here so coming together for + + align:start position:0% +square here so coming together for + + + align:start position:0% +square here so coming together for +square matrices means these three pieces + + align:start position:0% +square matrices means these three pieces + + + align:start position:0% +square matrices means these three pieces +come together and they come together in + + align:start position:0% +come together and they come together in + + + align:start position:0% +come together and they come together in +that beautiful fact that if that all + + align:start position:0% +that beautiful fact that if that all + + + align:start position:0% +that beautiful fact that if that all +that if I have one of these I have the + + align:start position:0% +that if I have one of these I have the + + + align:start position:0% +that if I have one of these I have the +others that if I have but for symmetric + + align:start position:0% +others that if I have but for symmetric + + + align:start position:0% +others that if I have but for symmetric +matrices so that this will be the + + align:start position:0% +matrices so that this will be the + + + align:start position:0% +matrices so that this will be the +positive definite section and then the + + align:start position:0% +positive definite section and then the + + + align:start position:0% +positive definite section and then the +real climax of the course is to make + + align:start position:0% +real climax of the course is to make + + + align:start position:0% +real climax of the course is to make +everything come together for M by n + + align:start position:0% +everything come together for M by n + + + align:start position:0% +everything come together for M by n +matrices not necessarily symmetric bring + + align:start position:0% +matrices not necessarily symmetric bring + + + align:start position:0% +matrices not necessarily symmetric bring +bring everything together there and that + + align:start position:0% +bring everything together there and that + + + align:start position:0% +bring everything together there and that +will be the final thing ok so have a + + align:start position:0% +will be the final thing ok so have a + + + align:start position:0% +will be the final thing ok so have a +great weekend and don't forget symmetric + + align:start position:0% +great weekend and don't forget symmetric + + + align:start position:0% +great weekend and don't forget symmetric +matrices Thanks \ No newline at end of file diff --git a/UGKL1wHouho.txt b/UGKL1wHouho.txt new file mode 100644 index 0000000000000000000000000000000000000000..301736f5aea5fd4990c3398091c023941f1983f5 --- /dev/null +++ b/UGKL1wHouho.txt @@ -0,0 +1,6243 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +hi today we would like to begin our + + align:start position:0% +hi today we would like to begin our + + + align:start position:0% +hi today we would like to begin our +study of calculus of several real + + align:start position:0% +study of calculus of several real + + + align:start position:0% +study of calculus of several real +variables and as I mentioned in our last + + align:start position:0% +variables and as I mentioned in our last + + + align:start position:0% +variables and as I mentioned in our last +lecture I would like to begin it from + + align:start position:0% +lecture I would like to begin it from + + + align:start position:0% +lecture I would like to begin it from +the traditional point of view and I + + align:start position:0% +the traditional point of view and I + + + align:start position:0% +the traditional point of view and I +guess I'd like to make a little bit of a + + align:start position:0% +guess I'd like to make a little bit of a + + + align:start position:0% +guess I'd like to make a little bit of a +short speech even before we begin that + + align:start position:0% +short speech even before we begin that + + + align:start position:0% +short speech even before we begin that +there may be a little bit of danger that + + align:start position:0% +there may be a little bit of danger that + + + align:start position:0% +there may be a little bit of danger that +in the way I've been emphasizing ing the + + align:start position:0% +in the way I've been emphasizing ing the + + + align:start position:0% +in the way I've been emphasizing ing the +modern approach to mathematics that one + + align:start position:0% +modern approach to mathematics that one + + + align:start position:0% +modern approach to mathematics that one +may actually believe that the the + + align:start position:0% +may actually believe that the the + + + align:start position:0% +may actually believe that the the +traditional approach to mathematics left + + align:start position:0% +traditional approach to mathematics left + + + align:start position:0% +traditional approach to mathematics left +very very much to be desired the answer + + align:start position:0% +very very much to be desired the answer + + + align:start position:0% +very very much to be desired the answer +is it didn't really that the role of + + align:start position:0% +is it didn't really that the role of + + + align:start position:0% +is it didn't really that the role of +logic in good traditional mathematics + + align:start position:0% +logic in good traditional mathematics + + + align:start position:0% +logic in good traditional mathematics +was about the same as it is in good + + align:start position:0% +was about the same as it is in good + + + align:start position:0% +was about the same as it is in good +modern mathematics that in fact if we + + align:start position:0% +modern mathematics that in fact if we + + + align:start position:0% +modern mathematics that in fact if we +Define new mathematics as meaning + + align:start position:0% +Define new mathematics as meaning + + + align:start position:0% +Define new mathematics as meaning +meaningful mathematics there really was + + align:start position:0% +meaningful mathematics there really was + + + align:start position:0% +meaningful mathematics there really was +no difference between the two approaches + + align:start position:0% +no difference between the two approaches + + + align:start position:0% +no difference between the two approaches +except for the fact that after you have + + align:start position:0% +except for the fact that after you have + + + align:start position:0% +except for the fact that after you have +a couple of hundred years of hindsight + + align:start position:0% +a couple of hundred years of hindsight + + + align:start position:0% +a couple of hundred years of hindsight +and can take a subject apart from a + + align:start position:0% +and can take a subject apart from a + + + align:start position:0% +and can take a subject apart from a +different point of view then obviously + + align:start position:0% +different point of view then obviously + + + align:start position:0% +different point of view then obviously +it's no great surprise that you can find + + align:start position:0% +it's no great surprise that you can find + + + align:start position:0% +it's no great surprise that you can find +cleaner ways of really presenting the + + align:start position:0% +cleaner ways of really presenting the + + + align:start position:0% +cleaner ways of really presenting the +topic it's the old cliche of hindsight + + align:start position:0% +topic it's the old cliche of hindsight + + + align:start position:0% +topic it's the old cliche of hindsight +being better than foresight by a Don + + align:start position:0% +being better than foresight by a Don + + + align:start position:0% +being better than foresight by a Don +site or some such thing but at any rate + + align:start position:0% +site or some such thing but at any rate + + + align:start position:0% +site or some such thing but at any rate +without further Ado let's actually look + + align:start position:0% +without further Ado let's actually look + + + align:start position:0% +without further Ado let's actually look +at the introduction to calculus of + + align:start position:0% +at the introduction to calculus of + + + align:start position:0% +at the introduction to calculus of +several real variables from a + + align:start position:0% +several real variables from a + + + align:start position:0% +several real variables from a +traditional point of view and I've + + align:start position:0% +traditional point of view and I've + + + align:start position:0% +traditional point of view and I've +abbreviated that title to Simply say + + align:start position:0% +abbreviated that title to Simply say + + + align:start position:0% +abbreviated that title to Simply say +calculus of several variables whereas I + + align:start position:0% +calculus of several variables whereas I + + + align:start position:0% +calculus of several variables whereas I +say that think of two things first of + + align:start position:0% +say that think of two things first of + + + align:start position:0% +say that think of two things first of +all it's an introduction and second of + + align:start position:0% +all it's an introduction and second of + + + align:start position:0% +all it's an introduction and second of +all we're going to be doing this from + + align:start position:0% +all we're going to be doing this from + + + align:start position:0% +all we're going to be doing this from +the traditional point of view now what + + align:start position:0% +the traditional point of view now what + + + align:start position:0% +the traditional point of view now what +we're assuming is remember last time we + + align:start position:0% +we're assuming is remember last time we + + + align:start position:0% +we're assuming is remember last time we +talked about functions of several real + + align:start position:0% +talked about functions of several real + + + align:start position:0% +talked about functions of several real +variables we talked about the limit + + align:start position:0% +variables we talked about the limit + + + align:start position:0% +variables we talked about the limit +concept gave you exercises that drilled + + align:start position:0% +concept gave you exercises that drilled + + + align:start position:0% +concept gave you exercises that drilled +you on what limits meant and the like + + align:start position:0% +you on what limits meant and the like + + + align:start position:0% +you on what limits meant and the like +and as a result it now makes sense to + + align:start position:0% +and as a result it now makes sense to + + + align:start position:0% +and as a result it now makes sense to +talk about uh the calculus the + + align:start position:0% +talk about uh the calculus the + + + align:start position:0% +talk about uh the calculus the +instantaneous rate of change except that + + align:start position:0% +instantaneous rate of change except that + + + align:start position:0% +instantaneous rate of change except that +you have an awful lot of variables in + + align:start position:0% +you have an awful lot of variables in + + + align:start position:0% +you have an awful lot of variables in +here in other words the general case + + align:start position:0% +here in other words the general case + + + align:start position:0% +here in other words the general case +that we'd like to tackle is the case + + align:start position:0% +that we'd like to tackle is the case + + + align:start position:0% +that we'd like to tackle is the case +where we have W being some real number + + align:start position:0% +where we have W being some real number + + + align:start position:0% +where we have W being some real number +being a function of the N independent + + align:start position:0% +being a function of the N independent + + + align:start position:0% +being a function of the N independent +variables X1 up to xn and of course you + + align:start position:0% +variables X1 up to xn and of course you + + + align:start position:0% +variables X1 up to xn and of course you +see the calculus applies to the F the W + + align:start position:0% +see the calculus applies to the F the W + + + align:start position:0% +see the calculus applies to the F the W +Used here is to indicate the fact that + + align:start position:0% +Used here is to indicate the fact that + + + align:start position:0% +Used here is to indicate the fact that +the output is a real number I it's like + + align:start position:0% +the output is a real number I it's like + + + align:start position:0% +the output is a real number I it's like +talking about F ofx versus y equal F ofx + + align:start position:0% +talking about F ofx versus y equal F ofx + + + align:start position:0% +talking about F ofx versus y equal F ofx +in a manner of speaking it's the F ofx + + align:start position:0% +in a manner of speaking it's the F ofx + + + align:start position:0% +in a manner of speaking it's the F ofx +that's important we won't get into that + + align:start position:0% +that's important we won't get into that + + + align:start position:0% +that's important we won't get into that +right now what was important though + + align:start position:0% +right now what was important though + + + align:start position:0% +right now what was important though +about y equals f ofx it indicated a + + align:start position:0% +about y equals f ofx it indicated a + + + align:start position:0% +about y equals f ofx it indicated a +graph graph and because it was a graph + + align:start position:0% +graph graph and because it was a graph + + + align:start position:0% +graph graph and because it was a graph +we could visualize things pictorially + + align:start position:0% +we could visualize things pictorially + + + align:start position:0% +we could visualize things pictorially +that might have been harder to + + align:start position:0% +that might have been harder to + + + align:start position:0% +that might have been harder to +understand analytically for this reason + + align:start position:0% +understand analytically for this reason + + + align:start position:0% +understand analytically for this reason +even though n may be any positive + + align:start position:0% +even though n may be any positive + + + align:start position:0% +even though n may be any positive +integer whatsoever preferably of course + + align:start position:0% +integer whatsoever preferably of course + + + align:start position:0% +integer whatsoever preferably of course +greater than one otherwise we wouldn't + + align:start position:0% +greater than one otherwise we wouldn't + + + align:start position:0% +greater than one otherwise we wouldn't +have a function of several variables + + align:start position:0% +have a function of several variables + + + align:start position:0% +have a function of several variables +fact that's a defition of a function of + + align:start position:0% +fact that's a defition of a function of + + + align:start position:0% +fact that's a defition of a function of +several variables it's an expression of + + align:start position:0% +several variables it's an expression of + + + align:start position:0% +several variables it's an expression of +this type where n is greater than one + + align:start position:0% +this type where n is greater than one + + + align:start position:0% +this type where n is greater than one +but in general and you'll notice this in + + align:start position:0% +but in general and you'll notice this in + + + align:start position:0% +but in general and you'll notice this in +the text as well we begin with the + + align:start position:0% +the text as well we begin with the + + + align:start position:0% +the text as well we begin with the +special case that n equals 2 because you + + align:start position:0% +special case that n equals 2 because you + + + align:start position:0% +special case that n equals 2 because you +see if n is two we need what two degrees + + align:start position:0% +see if n is two we need what two degrees + + + align:start position:0% +see if n is two we need what two degrees +of freedom to plot the independent + + align:start position:0% +of freedom to plot the independent + + + align:start position:0% +of freedom to plot the independent +variables that would be the XY plane for + + align:start position:0% +variables that would be the XY plane for + + + align:start position:0% +variables that would be the XY plane for +example a third degree of Freedom say + + align:start position:0% +example a third degree of Freedom say + + + align:start position:0% +example a third degree of Freedom say +the z-axis often called The W axis + + align:start position:0% +the z-axis often called The W axis + + + align:start position:0% +the z-axis often called The W axis +because of this symbolism in other it in + + align:start position:0% +because of this symbolism in other it in + + + align:start position:0% +because of this symbolism in other it in +the same way that I could graph a real + + align:start position:0% +the same way that I could graph a real + + + align:start position:0% +the same way that I could graph a real +valued function of a single real + + align:start position:0% +valued function of a single real + + + align:start position:0% +valued function of a single real +variable as a curve in the plane I can + + align:start position:0% +variable as a curve in the plane I can + + + align:start position:0% +variable as a curve in the plane I can +graph a real valued function of two real + + align:start position:0% +graph a real valued function of two real + + + align:start position:0% +graph a real valued function of two real +variables as a surface in + + align:start position:0% +variables as a surface in + + + align:start position:0% +variables as a surface in +three-dimensional space and as a result + + align:start position:0% +three-dimensional space and as a result + + + align:start position:0% +three-dimensional space and as a result +when one is adjusting to new language + + align:start position:0% +when one is adjusting to new language + + + align:start position:0% +when one is adjusting to new language +it's nice to take the case n equals 2 + + align:start position:0% +it's nice to take the case n equals 2 + + + align:start position:0% +it's nice to take the case n equals 2 +simply because you can view things + + align:start position:0% +simply because you can view things + + + align:start position:0% +simply because you can view things +pictorially the danger of course with n + + align:start position:0% +pictorially the danger of course with n + + + align:start position:0% +pictorially the danger of course with n +equals 2 is you get so used to the + + align:start position:0% +equals 2 is you get so used to the + + + align:start position:0% +equals 2 is you get so used to the +picture that after a while you forget + + align:start position:0% +picture that after a while you forget + + + align:start position:0% +picture that after a while you forget +that n could have been more than two so + + align:start position:0% +that n could have been more than two so + + + align:start position:0% +that n could have been more than two so +I will try to pay uh homage to both + + align:start position:0% +I will try to pay uh homage to both + + + align:start position:0% +I will try to pay uh homage to both +points of view I will simply mention + + align:start position:0% +points of view I will simply mention + + + align:start position:0% +points of view I will simply mention +here that we will often let N equal 2 to + + align:start position:0% +here that we will often let N equal 2 to + + + align:start position:0% +here that we will often let N equal 2 to +take advantage of geometry when we do + + align:start position:0% +take advantage of geometry when we do + + + align:start position:0% +take advantage of geometry when we do +this the usual notation is to let W + + align:start position:0% +this the usual notation is to let W + + + align:start position:0% +this the usual notation is to let W +equal F of XY where X and Y are + + align:start position:0% +equal F of XY where X and Y are + + + align:start position:0% +equal F of XY where X and Y are +independent and I should mention why + + align:start position:0% +independent and I should mention why + + + align:start position:0% +independent and I should mention why +it's so important to talk about + + align:start position:0% +it's so important to talk about + + + align:start position:0% +it's so important to talk about +independent variables the it'll become + + align:start position:0% +independent variables the it'll become + + + align:start position:0% +independent variables the it'll become +clear in a moment let me just tell you + + align:start position:0% +clear in a moment let me just tell you + + + align:start position:0% +clear in a moment let me just tell you +what independent means and then I'll + + align:start position:0% +what independent means and then I'll + + + align:start position:0% +what independent means and then I'll +show you why it becomes clear in a + + align:start position:0% +show you why it becomes clear in a + + + align:start position:0% +show you why it becomes clear in a +moment to say that X and Y are + + align:start position:0% +moment to say that X and Y are + + + align:start position:0% +moment to say that X and Y are +independent simply means that you can + + align:start position:0% +independent simply means that you can + + + align:start position:0% +independent simply means that you can +choose one of the two variables without + + align:start position:0% +choose one of the two variables without + + + align:start position:0% +choose one of the two variables without +determining the other for example if I + + align:start position:0% +determining the other for example if I + + + align:start position:0% +determining the other for example if I +were to say let y equal 2x then + + align:start position:0% +were to say let y equal 2x then + + + align:start position:0% +were to say let y equal 2x then +certainly Y and X are not independent + + align:start position:0% +certainly Y and X are not independent + + + align:start position:0% +certainly Y and X are not independent +because the choice of X determines the + + align:start position:0% +because the choice of X determines the + + + align:start position:0% +because the choice of X determines the +choice of Y but to say that X and Y are + + align:start position:0% +choice of Y but to say that X and Y are + + + align:start position:0% +choice of Y but to say that X and Y are +independent and that's what we mean by + + align:start position:0% +independent and that's what we mean by + + + align:start position:0% +independent and that's what we mean by +two degrees of freedom is I can take any + + align:start position:0% +two degrees of freedom is I can take any + + + align:start position:0% +two degrees of freedom is I can take any +value of x that I want and not be + + align:start position:0% +value of x that I want and not be + + + align:start position:0% +value of x that I want and not be +impeded as to the choice of Y that I + + align:start position:0% +impeded as to the choice of Y that I + + + align:start position:0% +impeded as to the choice of Y that I +want and that's why we say the domain is + + align:start position:0% +want and that's why we say the domain is + + + align:start position:0% +want and that's why we say the domain is +the XY plane I have two degrees of + + align:start position:0% +the XY plane I have two degrees of + + + align:start position:0% +the XY plane I have two degrees of +freedom I can roam anywhere through the + + align:start position:0% +freedom I can roam anywhere through the + + + align:start position:0% +freedom I can roam anywhere through the +plane this way but the reason that we + + align:start position:0% +plane this way but the reason that we + + + align:start position:0% +plane this way but the reason that we +want this is as follows and this is + + align:start position:0% +want this is as follows and this is + + + align:start position:0% +want this is as follows and this is +where the the traditional mathematics + + align:start position:0% +where the the traditional mathematics + + + align:start position:0% +where the the traditional mathematics +was every bit as logical as the modern + + align:start position:0% +was every bit as logical as the modern + + + align:start position:0% +was every bit as logical as the modern +mathematics let's keep in mind that + + align:start position:0% +mathematics let's keep in mind that + + + align:start position:0% +mathematics let's keep in mind that +logic is the art of taking known + + align:start position:0% +logic is the art of taking known + + + align:start position:0% +logic is the art of taking known +situations that we know how to handle + + align:start position:0% +situations that we know how to handle + + + align:start position:0% +situations that we know how to handle +you see and reducing unfamiliar + + align:start position:0% +you see and reducing unfamiliar + + + align:start position:0% +you see and reducing unfamiliar +situations to these more familiar + + align:start position:0% +situations to these more familiar + + + align:start position:0% +situations to these more familiar +situations the point is that that even + + align:start position:0% +situations the point is that that even + + + align:start position:0% +situations the point is that that even +in traditional mathematics one knew how + + align:start position:0% +in traditional mathematics one knew how + + + align:start position:0% +in traditional mathematics one knew how +to handle the calculus of a single real + + align:start position:0% +to handle the calculus of a single real + + + align:start position:0% +to handle the calculus of a single real +variable so what one said was this given + + align:start position:0% +variable so what one said was this given + + + align:start position:0% +variable so what one said was this given +that W is a function of both X and Y + + align:start position:0% +that W is a function of both X and Y + + + align:start position:0% +that W is a function of both X and Y +let's hold y fixed for example and let X + + align:start position:0% +let's hold y fixed for example and let X + + + align:start position:0% +let's hold y fixed for example and let X +vary you see if I fix Y at some + + align:start position:0% +vary you see if I fix Y at some + + + align:start position:0% +vary you see if I fix Y at some +particular value and let X vary once + + align:start position:0% +particular value and let X vary once + + + align:start position:0% +particular value and let X vary once +I've made that fixed choice of Y I have + + align:start position:0% +I've made that fixed choice of Y I have + + + align:start position:0% +I've made that fixed choice of Y I have +W as a function of X alone and as long + + align:start position:0% +W as a function of X alone and as long + + + align:start position:0% +W as a function of X alone and as long +as W is a function of X alone I already + + align:start position:0% +as W is a function of X alone I already + + + align:start position:0% +as W is a function of X alone I already +know how to take the derivative of w + + align:start position:0% +know how to take the derivative of w + + + align:start position:0% +know how to take the derivative of w +with respect to x and by the way there's + + align:start position:0% +with respect to x and by the way there's + + + align:start position:0% +with respect to x and by the way there's +no favoritism here between X and Y in a + + align:start position:0% +no favoritism here between X and Y in a + + + align:start position:0% +no favoritism here between X and Y in a +similar way if I hold x constant and let + + align:start position:0% +similar way if I hold x constant and let + + + align:start position:0% +similar way if I hold x constant and let +y vary then W is a function of Y alone + + align:start position:0% +y vary then W is a function of Y alone + + + align:start position:0% +y vary then W is a function of Y alone +and I can then find the derivative of w + + align:start position:0% +and I can then find the derivative of w + + + align:start position:0% +and I can then find the derivative of w +with respect to Y and these things were + + align:start position:0% +with respect to Y and these things were + + + align:start position:0% +with respect to Y and these things were +called partial derivatives you see + + align:start position:0% +called partial derivatives you see + + + align:start position:0% +called partial derivatives you see +because it involved holding what all but + + align:start position:0% +because it involved holding what all but + + + align:start position:0% +because it involved holding what all but +one of the variables constant we'll go + + align:start position:0% +one of the variables constant we'll go + + + align:start position:0% +one of the variables constant we'll go +into that in more detail as we go along + + align:start position:0% +into that in more detail as we go along + + + align:start position:0% +into that in more detail as we go along +but the whole idea is what by choosing + + align:start position:0% +but the whole idea is what by choosing + + + align:start position:0% +but the whole idea is what by choosing +the VAR to be independent we can hold + + align:start position:0% +the VAR to be independent we can hold + + + align:start position:0% +the VAR to be independent we can hold +all of them but one at a time constant + + align:start position:0% +all of them but one at a time constant + + + align:start position:0% +all of them but one at a time constant +and as long as we're doing that the + + align:start position:0% +and as long as we're doing that the + + + align:start position:0% +and as long as we're doing that the +resulting function is a function of a + + align:start position:0% +resulting function is a function of a + + + align:start position:0% +resulting function is a function of a +single real variable and this reduces us + + align:start position:0% +single real variable and this reduces us + + + align:start position:0% +single real variable and this reduces us +to part one of our course so at any rate + + align:start position:0% +to part one of our course so at any rate + + + align:start position:0% +to part one of our course so at any rate +what we're saying is fix Y at some + + align:start position:0% +what we're saying is fix Y at some + + + align:start position:0% +what we're saying is fix Y at some +constant value say yal y Sub 0 and we + + align:start position:0% +constant value say yal y Sub 0 and we + + + align:start position:0% +constant value say yal y Sub 0 and we +then let X vary as an ordinary + + align:start position:0% +then let X vary as an ordinary + + + align:start position:0% +then let X vary as an ordinary +one-dimensional calculus between x0 + + align:start position:0% +one-dimensional calculus between x0 + + + align:start position:0% +one-dimensional calculus between x0 +minus the magnitude of Delta X and x0 + + align:start position:0% +minus the magnitude of Delta X and x0 + + + align:start position:0% +minus the magnitude of Delta X and x0 +plus the magnitude of Delta X in other + + align:start position:0% +plus the magnitude of Delta X in other + + + align:start position:0% +plus the magnitude of Delta X in other +words we mark off an interval of + + align:start position:0% +words we mark off an interval of + + + align:start position:0% +words we mark off an interval of +magnitude Delta X on either side of x0 + + align:start position:0% +magnitude Delta X on either side of x0 + + + align:start position:0% +magnitude Delta X on either side of x0 +and let X be any place in here then what + + align:start position:0% +and let X be any place in here then what + + + align:start position:0% +and let X be any place in here then what +we do is remembering that y0 is a + + align:start position:0% +we do is remembering that y0 is a + + + align:start position:0% +we do is remembering that y0 is a +constant and that this function no + + align:start position:0% +constant and that this function no + + + align:start position:0% +constant and that this function no +matter how complicated it looks like is + + align:start position:0% +matter how complicated it looks like is + + + align:start position:0% +matter how complicated it looks like is +a function of just Delta X alone we + + align:start position:0% +a function of just Delta X alone we + + + align:start position:0% +a function of just Delta X alone we +mimic the definition of an ordinary + + align:start position:0% +mimic the definition of an ordinary + + + align:start position:0% +mimic the definition of an ordinary +derivative in other words we take the + + align:start position:0% +derivative in other words we take the + + + align:start position:0% +derivative in other words we take the +limit as Delta X approaches 0 of f of x0 + + align:start position:0% +limit as Delta X approaches 0 of f of x0 + + + align:start position:0% +limit as Delta X approaches 0 of f of x0 ++ Delta X comma y0 minus F of x0 comma + + align:start position:0% ++ Delta X comma y0 minus F of x0 comma + + + align:start position:0% ++ Delta X comma y0 minus F of x0 comma +y0 and divide that by Delta X in other + + align:start position:0% +y0 and divide that by Delta X in other + + + align:start position:0% +y0 and divide that by Delta X in other +words with y0 being treated as a + + align:start position:0% +words with y0 being treated as a + + + align:start position:0% +words with y0 being treated as a +constant notice that essentially this is + + align:start position:0% +constant notice that essentially this is + + + align:start position:0% +constant notice that essentially this is +the change in f as X varies between x0 + + align:start position:0% +the change in f as X varies between x0 + + + align:start position:0% +the change in f as X varies between x0 +and x0 plus Delta x divided by the + + align:start position:0% +and x0 plus Delta x divided by the + + + align:start position:0% +and x0 plus Delta x divided by the +change in X in other words it's the + + align:start position:0% +change in X in other words it's the + + + align:start position:0% +change in X in other words it's the +limit of an average rate of change of f + + align:start position:0% +limit of an average rate of change of f + + + align:start position:0% +limit of an average rate of change of f +ofx with respect to X for a fixed value + + align:start position:0% +ofx with respect to X for a fixed value + + + align:start position:0% +ofx with respect to X for a fixed value +of y0 and to indicate that we write this + + align:start position:0% + + + + align:start position:0% + +analogously I would say to how we write + + align:start position:0% +analogously I would say to how we write + + + align:start position:0% +analogously I would say to how we write +functions of a single real variable in + + align:start position:0% +functions of a single real variable in + + + align:start position:0% +functions of a single real variable in +other words we write F Prime instead of + + align:start position:0% +other words we write F Prime instead of + + + align:start position:0% +other words we write F Prime instead of +f Prime we indicate let me put this way + + align:start position:0% +f Prime we indicate let me put this way + + + align:start position:0% +f Prime we indicate let me put this way +when you had only one real variable was + + align:start position:0% +when you had only one real variable was + + + align:start position:0% +when you had only one real variable was +there any danger of misinterpreting the + + align:start position:0% +there any danger of misinterpreting the + + + align:start position:0% +there any danger of misinterpreting the +prime after all with only one + + align:start position:0% +prime after all with only one + + + align:start position:0% +prime after all with only one +independent variable when you said + + align:start position:0% +independent variable when you said + + + align:start position:0% +independent variable when you said +derivative it was obvious what variable + + align:start position:0% +derivative it was obvious what variable + + + align:start position:0% +derivative it was obvious what variable +you were differentiating with respect to + + align:start position:0% +you were differentiating with respect to + + + align:start position:0% +you were differentiating with respect to +here there are two variables X and Y so + + align:start position:0% +here there are two variables X and Y so + + + align:start position:0% +here there are two variables X and Y so +instead of the Prime as a subscript we + + align:start position:0% +instead of the Prime as a subscript we + + + align:start position:0% +instead of the Prime as a subscript we +write down the variable with respect to + + align:start position:0% +write down the variable with respect to + + + align:start position:0% +write down the variable with respect to +which we're taking the derivative and + + align:start position:0% +which we're taking the derivative and + + + align:start position:0% +which we're taking the derivative and +then we put in the point at which the + + align:start position:0% +then we put in the point at which the + + + align:start position:0% +then we put in the point at which the +derivative is being evaluated you see in + + align:start position:0% +derivative is being evaluated you see in + + + align:start position:0% +derivative is being evaluated you see in +a similar way to have defined F suby of + + align:start position:0% +a similar way to have defined F suby of + + + align:start position:0% +a similar way to have defined F suby of +x0 y0 that would have meant what we hold + + align:start position:0% +x0 y0 that would have meant what we hold + + + align:start position:0% +x0 y0 that would have meant what we hold +x constant at some value + + align:start position:0% +x constant at some value + + + align:start position:0% +x constant at some value +x0 let y vary between y0 and y0 + Delta + + align:start position:0% +x0 let y vary between y0 and y0 + Delta + + + align:start position:0% +x0 let y vary between y0 and y0 + Delta +Y and take the limit of this expression + + align:start position:0% +Y and take the limit of this expression + + + align:start position:0% +Y and take the limit of this expression +F ofx 0a y0 + Delta Yus F of x0 y0 over + + align:start position:0% +F ofx 0a y0 + Delta Yus F of x0 y0 over + + + align:start position:0% +F ofx 0a y0 + Delta Yus F of x0 y0 over +Delta y take the limit of that + + align:start position:0% +Delta y take the limit of that + + + align:start position:0% +Delta y take the limit of that +expression as Delta y approaches zero + + align:start position:0% +expression as Delta y approaches zero + + + align:start position:0% +expression as Delta y approaches zero +you see and we're going to show this + + align:start position:0% +you see and we're going to show this + + + align:start position:0% +you see and we're going to show this +pictorially in a while after all that's + + align:start position:0% +pictorially in a while after all that's + + + align:start position:0% +pictorially in a while after all that's +why we chose the case n equals 2 was so + + align:start position:0% +why we chose the case n equals 2 was so + + + align:start position:0% +why we chose the case n equals 2 was so +that we could eventually illustrate this + + align:start position:0% +that we could eventually illustrate this + + + align:start position:0% +that we could eventually illustrate this +thing pictorially but for the time being + + align:start position:0% +thing pictorially but for the time being + + + align:start position:0% +thing pictorially but for the time being +I prefer not to introduce the picture + + align:start position:0% +I prefer not to introduce the picture + + + align:start position:0% +I prefer not to introduce the picture +because I want you to see that even in + + align:start position:0% +because I want you to see that even in + + + align:start position:0% +because I want you to see that even in +the case where my input consists of an + + align:start position:0% +the case where my input consists of an + + + align:start position:0% +the case where my input consists of an +npple where n is greater than two or + + align:start position:0% +npple where n is greater than two or + + + align:start position:0% +npple where n is greater than two or +three or four whatever you want that do + + align:start position:0% +three or four whatever you want that do + + + align:start position:0% +three or four whatever you want that do +this thing still make sense in other + + align:start position:0% +this thing still make sense in other + + + align:start position:0% +this thing still make sense in other +words in general suppose W is a function + + align:start position:0% +words in general suppose W is a function + + + align:start position:0% +words in general suppose W is a function +of the N independent variables x sub 1 + + align:start position:0% +of the N independent variables x sub 1 + + + align:start position:0% +of the N independent variables x sub 1 +up to X subn and I want to compute f of + + align:start position:0% +up to X subn and I want to compute f of + + + align:start position:0% +up to X subn and I want to compute f of +x sub1 at the point X1 = A1 Etc xn = a n + + align:start position:0% +x sub1 at the point X1 = A1 Etc xn = a n + + + align:start position:0% +x sub1 at the point X1 = A1 Etc xn = a n +by definition what I do is I hold A2 up + + align:start position:0% +by definition what I do is I hold A2 up + + + align:start position:0% +by definition what I do is I hold A2 up +to a n + + align:start position:0% +to a n + + + align:start position:0% +to a n +constant I let X1 vary from A1 to A1 + + + align:start position:0% +constant I let X1 vary from A1 to A1 + + + + align:start position:0% +constant I let X1 vary from A1 to A1 + +Delta x i compute what f F of A1 + Delta + + align:start position:0% +Delta x i compute what f F of A1 + Delta + + + align:start position:0% +Delta x i compute what f F of A1 + Delta +X comma A2 Etc comma a n minus F of A1 + + align:start position:0% +X comma A2 Etc comma a n minus F of A1 + + + align:start position:0% +X comma A2 Etc comma a n minus F of A1 +up to a n noticing that that numerator + + align:start position:0% +up to a n noticing that that numerator + + + align:start position:0% +up to a n noticing that that numerator +is simply the change in + + align:start position:0% +is simply the change in + + + align:start position:0% +is simply the change in +f as X1 varies from A1 to A1 Plus Delta + + align:start position:0% +f as X1 varies from A1 to A1 Plus Delta + + + align:start position:0% +f as X1 varies from A1 to A1 Plus Delta +X1 while all the other variables are + + align:start position:0% +X1 while all the other variables are + + + align:start position:0% +X1 while all the other variables are +being held constant which of course I + + align:start position:0% +being held constant which of course I + + + align:start position:0% +being held constant which of course I +can do if the variables are independent + + align:start position:0% +can do if the variables are independent + + + align:start position:0% +can do if the variables are independent +I then divide that by Delta X1 that's + + align:start position:0% +I then divide that by Delta X1 that's + + + align:start position:0% +I then divide that by Delta X1 that's +the average rate of change then I take + + align:start position:0% +the average rate of change then I take + + + align:start position:0% +the average rate of change then I take +the limit as Delta X1 approaches zero + + align:start position:0% +the limit as Delta X1 approaches zero + + + align:start position:0% +the limit as Delta X1 approaches zero +and this I can do for any number of + + align:start position:0% +and this I can do for any number of + + + align:start position:0% +and this I can do for any number of +variables provided that they're + + align:start position:0% +variables provided that they're + + + align:start position:0% +variables provided that they're +independent keep that in mind if x subn + + align:start position:0% +independent keep that in mind if x subn + + + align:start position:0% +independent keep that in mind if x subn +could be expressed in terms of the + + align:start position:0% +could be expressed in terms of the + + + align:start position:0% +could be expressed in terms of the +remaining X's how can I hold a subn + + align:start position:0% +remaining X's how can I hold a subn + + + align:start position:0% +remaining X's how can I hold a subn +constant while or how can I vary a subn + + align:start position:0% +constant while or how can I vary a subn + + + align:start position:0% +constant while or how can I vary a subn +while I hold the other ones constant in + + align:start position:0% +while I hold the other ones constant in + + + align:start position:0% +while I hold the other ones constant in +other words if the a ends if if one of + + align:start position:0% +other words if the a ends if if one of + + + align:start position:0% +other words if the a ends if if one of +the variables depends on the others they + + align:start position:0% +the variables depends on the others they + + + align:start position:0% +the variables depends on the others they +are related in terms of their motion + + align:start position:0% +are related in terms of their motion + + + align:start position:0% +are related in terms of their motion +keep in mind here I just chose Delta X1 + + align:start position:0% +keep in mind here I just chose Delta X1 + + + align:start position:0% +keep in mind here I just chose Delta X1 +analogous definitions held for f subx + + align:start position:0% +analogous definitions held for f subx + + + align:start position:0% +analogous definitions held for f subx +sub 2 FX sub3 Etc okay I think again + + align:start position:0% +sub 2 FX sub3 Etc okay I think again + + + align:start position:0% +sub 2 FX sub3 Etc okay I think again +that once you see a few examples the + + align:start position:0% +that once you see a few examples the + + + align:start position:0% +that once you see a few examples the +mystery vanishes what this thing says in + + align:start position:0% +mystery vanishes what this thing says in + + + align:start position:0% +mystery vanishes what this thing says in +plain English is that when you have a + + align:start position:0% +plain English is that when you have a + + + align:start position:0% +plain English is that when you have a +function of several variables and you + + align:start position:0% +function of several variables and you + + + align:start position:0% +function of several variables and you +want to take the derivative with respect + + align:start position:0% +want to take the derivative with respect + + + align:start position:0% +want to take the derivative with respect +to one of those variables pretend that + + align:start position:0% +to one of those variables pretend that + + + align:start position:0% +to one of those variables pretend that +every one of the other variables was + + align:start position:0% +every one of the other variables was + + + align:start position:0% +every one of the other variables was +being held constant let me give you an + + align:start position:0% +being held constant let me give you an + + + align:start position:0% +being held constant let me give you an +example let W be F of X1 X2 X3 where + + align:start position:0% +example let W be F of X1 X2 X3 where + + + align:start position:0% +example let W be F of X1 X2 X3 where +where the specific F that I have in mind + + align:start position:0% +where the specific F that I have in mind + + + align:start position:0% +where the specific F that I have in mind +is obtained as follows it's X1 * X2 * X3 + + align:start position:0% +is obtained as follows it's X1 * X2 * X3 + + + align:start position:0% +is obtained as follows it's X1 * X2 * X3 +plus e to the X1 power now to take the + + align:start position:0% +plus e to the X1 power now to take the + + + align:start position:0% +plus e to the X1 power now to take the +derivative of this with respect to X1 + + align:start position:0% +derivative of this with respect to X1 + + + align:start position:0% +derivative of this with respect to X1 +all this says is treat X2 and X3 as if + + align:start position:0% +all this says is treat X2 and X3 as if + + + align:start position:0% +all this says is treat X2 and X3 as if +they were constants well look at if I + + align:start position:0% +they were constants well look at if I + + + align:start position:0% +they were constants well look at if I +treat X2 and X3 as if they were + + align:start position:0% +treat X2 and X3 as if they were + + + align:start position:0% +treat X2 and X3 as if they were +constants if I differentiate this with + + align:start position:0% +constants if I differentiate this with + + + align:start position:0% +constants if I differentiate this with +respect to X1 all I have left is what + + align:start position:0% +respect to X1 all I have left is what + + + align:start position:0% +respect to X1 all I have left is what +this particular constant which is X2 * + + align:start position:0% +this particular constant which is X2 * + + + align:start position:0% +this particular constant which is X2 * +X3 and a derivative of e the X1 is with + + align:start position:0% +X3 and a derivative of e the X1 is with + + + align:start position:0% +X3 and a derivative of e the X1 is with +respect to X1 is e to the X1 therefore F + + align:start position:0% +respect to X1 is e to the X1 therefore F + + + align:start position:0% +respect to X1 is e to the X1 therefore F +subx1 in this case is X2 X3 plus e to + + align:start position:0% +subx1 in this case is X2 X3 plus e to + + + align:start position:0% +subx1 in this case is X2 X3 plus e to +the X1 in particular if I evaluate F + + align:start position:0% +the X1 in particular if I evaluate F + + + align:start position:0% +the X1 in particular if I evaluate F +subx sub1 at the 3le 1 2 3 namely I + + align:start position:0% +subx sub1 at the 3le 1 2 3 namely I + + + align:start position:0% +subx sub1 at the 3le 1 2 3 namely I +replace X1 by 1 X2 by 2 X3 by 3 I obtain + + align:start position:0% +replace X1 by 1 X2 by 2 X3 by 3 I obtain + + + align:start position:0% +replace X1 by 1 X2 by 2 X3 by 3 I obtain +what 2 * 3 + e to the first Power in + + align:start position:0% +what 2 * 3 + e to the first Power in + + + align:start position:0% +what 2 * 3 + e to the first Power in +other words this is just a number 6 + 8 + + align:start position:0% +other words this is just a number 6 + 8 + + + align:start position:0% +other words this is just a number 6 + 8 +on the other hand if I had decided to + + align:start position:0% +on the other hand if I had decided to + + + align:start position:0% +on the other hand if I had decided to +differentiate this with respect to X2 I + + align:start position:0% +differentiate this with respect to X2 I + + + align:start position:0% +differentiate this with respect to X2 I +would have treated X1 and X3 as + + align:start position:0% +would have treated X1 and X3 as + + + align:start position:0% +would have treated X1 and X3 as +constants with X1 and X3 as constants + + align:start position:0% +constants with X1 and X3 as constants + + + align:start position:0% +constants with X1 and X3 as constants +the derivative of this with respect to + + align:start position:0% +the derivative of this with respect to + + + align:start position:0% +the derivative of this with respect to +X2 is just X1 + + align:start position:0% +X2 is just X1 + + + align:start position:0% +X2 is just X1 +X3 treating X1 as a constant the + + align:start position:0% +X3 treating X1 as a constant the + + + align:start position:0% +X3 treating X1 as a constant the +derivative of e to the X1 with respect + + align:start position:0% +derivative of e to the X1 with respect + + + align:start position:0% +derivative of e to the X1 with respect +to the variable X3 is zero because the + + align:start position:0% +to the variable X3 is zero because the + + + align:start position:0% +to the variable X3 is zero because the +derivative of any constant is zero + + align:start position:0% +derivative of any constant is zero + + + align:start position:0% +derivative of any constant is zero +notice that this is not really a + + align:start position:0% +notice that this is not really a + + + align:start position:0% +notice that this is not really a +constant it's a constant once I fixed X1 + + align:start position:0% +constant it's a constant once I fixed X1 + + + align:start position:0% +constant it's a constant once I fixed X1 +at a particular value which is what this + + align:start position:0% +at a particular value which is what this + + + align:start position:0% +at a particular value which is what this +particular definition + + align:start position:0% +particular definition + + + align:start position:0% +particular definition +says in particular F subx sub 2 of 1 2 3 + + align:start position:0% +says in particular F subx sub 2 of 1 2 3 + + + align:start position:0% +says in particular F subx sub 2 of 1 2 3 +is 1 * 3 or three I should also mention + + align:start position:0% +is 1 * 3 or three I should also mention + + + align:start position:0% +is 1 * 3 or three I should also mention +that sometimes instead of writing F ofx + + align:start position:0% +that sometimes instead of writing F ofx + + + align:start position:0% +that sometimes instead of writing F ofx +sub one we write something that looks + + align:start position:0% +sub one we write something that looks + + + align:start position:0% +sub one we write something that looks +like the regular derivative only we make + + align:start position:0% +like the regular derivative only we make + + + align:start position:0% +like the regular derivative only we make +a funny kind of script D instead of an + + align:start position:0% +a funny kind of script D instead of an + + + align:start position:0% +a funny kind of script D instead of an +ordinary D this is read the partial + + align:start position:0% +ordinary D this is read the partial + + + align:start position:0% +ordinary D this is read the partial +derivative of w with respect to X1 and + + align:start position:0% +derivative of w with respect to X1 and + + + align:start position:0% +derivative of w with respect to X1 and +the relationship between these two + + align:start position:0% +the relationship between these two + + + align:start position:0% +the relationship between these two +notations is rather similar to the + + align:start position:0% +notations is rather similar to the + + + align:start position:0% +notations is rather similar to the +relationship that exists between the + + align:start position:0% +relationship that exists between the + + + align:start position:0% +relationship that exists between the +notations Dy DX and frime of X at any + + align:start position:0% +notations Dy DX and frime of X at any + + + align:start position:0% +notations Dy DX and frime of X at any +rate if we have the N independent + + align:start position:0% +rate if we have the N independent + + + align:start position:0% +rate if we have the N independent +variables X1 up to xn and F is a + + align:start position:0% +variables X1 up to xn and F is a + + + align:start position:0% +variables X1 up to xn and F is a +function of those variables F subx sub1 + + align:start position:0% +function of those variables F subx sub1 + + + align:start position:0% +function of those variables F subx sub1 +Etc f subx subn are called the partial + + align:start position:0% +Etc f subx subn are called the partial + + + align:start position:0% +Etc f subx subn are called the partial +derivatives of f with respect to X1 up + + align:start position:0% +derivatives of f with respect to X1 up + + + align:start position:0% +derivatives of f with respect to X1 up +to xn respectively in other words this + + align:start position:0% +to xn respectively in other words this + + + align:start position:0% +to xn respectively in other words this +means what the partial derivative of + + align:start position:0% +means what the partial derivative of + + + align:start position:0% +means what the partial derivative of +with respect to X1 that means what take + + align:start position:0% +with respect to X1 that means what take + + + align:start position:0% +with respect to X1 that means what take +the ordinary derivative as if X1 were + + align:start position:0% +the ordinary derivative as if X1 were + + + align:start position:0% +the ordinary derivative as if X1 were +the only variable this is the partial of + + align:start position:0% +the only variable this is the partial of + + + align:start position:0% +the only variable this is the partial of +f with respect to X subn that means take + + align:start position:0% +f with respect to X subn that means take + + + align:start position:0% +f with respect to X subn that means take +the ordinary derivative of f as if x + + align:start position:0% +the ordinary derivative of f as if x + + + align:start position:0% +the ordinary derivative of f as if x +subn were the only variable and you can + + align:start position:0% +subn were the only variable and you can + + + align:start position:0% +subn were the only variable and you can +always do this provided that your + + align:start position:0% +always do this provided that your + + + align:start position:0% +always do this provided that your +variables are + + align:start position:0% +variables are + + + align:start position:0% +variables are +independent because our definition so + + align:start position:0% +independent because our definition so + + + align:start position:0% +independent because our definition so +closely parallel the structure for what + + align:start position:0% +closely parallel the structure for what + + + align:start position:0% +closely parallel the structure for what +happened in the case of one independent + + align:start position:0% +happened in the case of one independent + + + align:start position:0% +happened in the case of one independent +variable including the limit theorems + + align:start position:0% +variable including the limit theorems + + + align:start position:0% +variable including the limit theorems +the distance formulas and what have you + + align:start position:0% +the distance formulas and what have you + + + align:start position:0% +the distance formulas and what have you +it turns out that the usual derivative + + align:start position:0% +it turns out that the usual derivative + + + align:start position:0% +it turns out that the usual derivative +properties still hold for example if W + + align:start position:0% +properties still hold for example if W + + + align:start position:0% +properties still hold for example if W +happens to be the function of the two + + align:start position:0% +happens to be the function of the two + + + align:start position:0% +happens to be the function of the two +independent variables e to 3x + y * sin + + align:start position:0% +independent variables e to 3x + y * sin + + + align:start position:0% +independent variables e to 3x + y * sin +2x - Y and I want to take the derivative + + align:start position:0% +2x - Y and I want to take the derivative + + + align:start position:0% +2x - Y and I want to take the derivative +of w with respect to X meaning + + align:start position:0% +of w with respect to X meaning + + + align:start position:0% +of w with respect to X meaning +differentiate this treating y as a + + align:start position:0% +differentiate this treating y as a + + + align:start position:0% +differentiate this treating y as a +constant notice that treating y as a + + align:start position:0% +constant notice that treating y as a + + + align:start position:0% +constant notice that treating y as a +constant gives me two + + align:start position:0% +constant gives me two + + + align:start position:0% +constant gives me two +functions of what x in other words I my + + align:start position:0% +functions of what x in other words I my + + + align:start position:0% +functions of what x in other words I my +function is a product of two functions + + align:start position:0% +function is a product of two functions + + + align:start position:0% +function is a product of two functions +Each of which depends on X so I use the + + align:start position:0% +Each of which depends on X so I use the + + + align:start position:0% +Each of which depends on X so I use the +ordinary product rule to differentiate + + align:start position:0% +ordinary product rule to differentiate + + + align:start position:0% +ordinary product rule to differentiate +this namely how do I use the product + + align:start position:0% +this namely how do I use the product + + + align:start position:0% +this namely how do I use the product +rule to take the partial of w respect to + + align:start position:0% +rule to take the partial of w respect to + + + align:start position:0% +rule to take the partial of w respect to +X I treat y as a constant and I + + align:start position:0% +X I treat y as a constant and I + + + align:start position:0% +X I treat y as a constant and I +differentiate as if x is the only + + align:start position:0% +differentiate as if x is the only + + + align:start position:0% +differentiate as if x is the only +variable I say what it's the first + + align:start position:0% +variable I say what it's the first + + + align:start position:0% +variable I say what it's the first +Factor e to 3x + y times the derivative + + align:start position:0% +Factor e to 3x + y times the derivative + + + align:start position:0% +Factor e to 3x + y times the derivative +of the second with respect to X treating + + align:start position:0% +of the second with respect to X treating + + + align:start position:0% +of the second with respect to X treating +y as a constant if I treat y as a + + align:start position:0% +y as a constant if I treat y as a + + + align:start position:0% +y as a constant if I treat y as a +constant the derivative of s of 2x - Y + + align:start position:0% +constant the derivative of s of 2x - Y + + + align:start position:0% +constant the derivative of s of 2x - Y +is cosine 2x - y times the derivative of + + align:start position:0% +is cosine 2x - y times the derivative of + + + align:start position:0% +is cosine 2x - y times the derivative of +what's inside with respect to X and + + align:start position:0% +what's inside with respect to X and + + + align:start position:0% +what's inside with respect to X and +that's just + + align:start position:0% +that's just + + + align:start position:0% +that's just +two plus what the second term times the + + align:start position:0% +two plus what the second term times the + + + align:start position:0% +two plus what the second term times the +derivative of the first and the + + align:start position:0% +derivative of the first and the + + + align:start position:0% +derivative of the first and the +derivative of e to 3x + y with respect + + align:start position:0% +derivative of e to 3x + y with respect + + + align:start position:0% +derivative of e to 3x + y with respect +to X treating y as a constant is e to 3x + + align:start position:0% +to X treating y as a constant is e to 3x + + + align:start position:0% +to X treating y as a constant is e to 3x ++ y times the derivative of 3x + y with + + align:start position:0% ++ y times the derivative of 3x + y with + + + align:start position:0% ++ y times the derivative of 3x + y with +respect to X which is just three and so + + align:start position:0% +respect to X which is just three and so + + + align:start position:0% +respect to X which is just three and so +I have the partial of w with respect to + + align:start position:0% +I have the partial of w with respect to + + + align:start position:0% +I have the partial of w with respect to +X in a similar way I could have found + + align:start position:0% +X in a similar way I could have found + + + align:start position:0% +X in a similar way I could have found +the partial of w with respect to Y + + align:start position:0% +the partial of w with respect to Y + + + align:start position:0% +the partial of w with respect to Y +Etc I should now introduce one little + + align:start position:0% +Etc I should now introduce one little + + + align:start position:0% +Etc I should now introduce one little +problem that will bother you maybe even + + align:start position:0% +problem that will bother you maybe even + + + align:start position:0% +problem that will bother you maybe even +after I help you with this in fact I + + align:start position:0% +after I help you with this in fact I + + + align:start position:0% +after I help you with this in fact I +guess what really crushes me is the + + align:start position:0% +guess what really crushes me is the + + + align:start position:0% +guess what really crushes me is the +student who comes up in a live class you + + align:start position:0% +student who comes up in a live class you + + + align:start position:0% +student who comes up in a live class you +know after class and says I understood + + align:start position:0% +know after class and says I understood + + + align:start position:0% +know after class and says I understood +it until I heard you lecture on it I + + align:start position:0% +it until I heard you lecture on it I + + + align:start position:0% +it until I heard you lecture on it I +hope this doesn't cause that problem but + + align:start position:0% +hope this doesn't cause that problem but + + + align:start position:0% +hope this doesn't cause that problem but +the danger is I tell you look it + + align:start position:0% +the danger is I tell you look it + + + align:start position:0% +the danger is I tell you look it +everything that happened for calculus of + + align:start position:0% +everything that happened for calculus of + + + align:start position:0% +everything that happened for calculus of +a single variable happens for calculus + + align:start position:0% +a single variable happens for calculus + + + align:start position:0% +a single variable happens for calculus +of several variables then all of a + + align:start position:0% +of several variables then all of a + + + align:start position:0% +of several variables then all of a +sudden you'll find in our textbook in + + align:start position:0% +sudden you'll find in our textbook in + + + align:start position:0% +sudden you'll find in our textbook in +every textbook just about they'll say + + align:start position:0% +every textbook just about they'll say + + + align:start position:0% +every textbook just about they'll say +things like look at if you take the + + align:start position:0% +things like look at if you take the + + + align:start position:0% +things like look at if you take the +partial of the variable U with respect + + align:start position:0% +partial of the variable U with respect + + + align:start position:0% +partial of the variable U with respect +to X you do not get the reciprocal of + + align:start position:0% +to X you do not get the reciprocal of + + + align:start position:0% +to X you do not get the reciprocal of +the partial of X with respect to you in + + align:start position:0% +the partial of X with respect to you in + + + align:start position:0% +the partial of X with respect to you in +other words remember for one variable + + align:start position:0% +other words remember for one variable + + + align:start position:0% +other words remember for one variable +dydx right was the reciprocal of DX Dy + + align:start position:0% +dydx right was the reciprocal of DX Dy + + + align:start position:0% +dydx right was the reciprocal of DX Dy +they say it's not true in several + + align:start position:0% +they say it's not true in several + + + align:start position:0% +they say it's not true in several +variables I have written in an + + align:start position:0% +variables I have written in an + + + align:start position:0% +variables I have written in an +accentuated question mark here because I + + align:start position:0% +accentuated question mark here because I + + + align:start position:0% +accentuated question mark here because I +want to explain something very important + + align:start position:0% +want to explain something very important + + + align:start position:0% +want to explain something very important +to you you and by the way if you + + align:start position:0% +to you you and by the way if you + + + align:start position:0% +to you you and by the way if you +understand this you're 90% of the way + + align:start position:0% +understand this you're 90% of the way + + + align:start position:0% +understand this you're 90% of the way +home free as far as understanding how + + align:start position:0% +home free as far as understanding how + + + align:start position:0% +home free as far as understanding how +calculus of several variables is used in + + align:start position:0% +calculus of several variables is used in + + + align:start position:0% +calculus of several variables is used in +most important applications let me take + + align:start position:0% +most important applications let me take + + + align:start position:0% +most important applications let me take +a very simple case let U equal x + y and + + align:start position:0% +a very simple case let U equal x + y and + + + align:start position:0% +a very simple case let U equal x + y and +let V equal xus y now obviously if U + + align:start position:0% +let V equal xus y now obviously if U + + + align:start position:0% +let V equal xus y now obviously if U +equal x + y the partial of U respect to + + align:start position:0% +equal x + y the partial of U respect to + + + align:start position:0% +equal x + y the partial of U respect to +X If We Hold y constant which read X is + + align:start position:0% +X If We Hold y constant which read X is + + + align:start position:0% +X If We Hold y constant which read X is +the only variable is one right the + + align:start position:0% +the only variable is one right the + + + align:start position:0% +the only variable is one right the +partial of view respect to X is one on + + align:start position:0% +partial of view respect to X is one on + + + align:start position:0% +partial of view respect to X is one on +the other hand notice that if I add + + align:start position:0% +the other hand notice that if I add + + + align:start position:0% +the other hand notice that if I add +these two equations the Y term drops out + + align:start position:0% +these two equations the Y term drops out + + + align:start position:0% +these two equations the Y term drops out +I get what 2x = U + V divide through by + + align:start position:0% +I get what 2x = U + V divide through by + + + align:start position:0% +I get what 2x = U + V divide through by +2 that says X is equal to 12 U + 12 V + + align:start position:0% +2 that says X is equal to 12 U + 12 V + + + align:start position:0% +2 that says X is equal to 12 U + 12 V +let me now take the partial of X with + + align:start position:0% +let me now take the partial of X with + + + align:start position:0% +let me now take the partial of X with +respect to U holding V constant treating + + align:start position:0% +respect to U holding V constant treating + + + align:start position:0% +respect to U holding V constant treating +U as the only variable it's easy for me + + align:start position:0% +U as the only variable it's easy for me + + + align:start position:0% +U as the only variable it's easy for me +to see that the partial of X with + + align:start position:0% +to see that the partial of X with + + + align:start position:0% +to see that the partial of X with +respect to U is2 and certainly if I now + + align:start position:0% +respect to U is2 and certainly if I now + + + align:start position:0% +respect to U is2 and certainly if I now +compare these two it should be clear + + align:start position:0% +compare these two it should be clear + + + align:start position:0% +compare these two it should be clear +that this is not the reciprocal of this + + align:start position:0% +that this is not the reciprocal of this + + + align:start position:0% +that this is not the reciprocal of this +or vice versa the point that I wanted to + + align:start position:0% +or vice versa the point that I wanted to + + + align:start position:0% +or vice versa the point that I wanted to +mention though was the following that + + align:start position:0% +mention though was the following that + + + align:start position:0% +mention though was the following that +when here we said take the partial of + + align:start position:0% +when here we said take the partial of + + + align:start position:0% +when here we said take the partial of +you with respect to X we were assuming + + align:start position:0% +you with respect to X we were assuming + + + align:start position:0% +you with respect to X we were assuming +that the independent variables were X + + align:start position:0% +that the independent variables were X + + + align:start position:0% +that the independent variables were X +and Y and when we said here take the + + align:start position:0% +and Y and when we said here take the + + + align:start position:0% +and Y and when we said here take the +partial of X with respect to U what did + + align:start position:0% +partial of X with respect to U what did + + + align:start position:0% +partial of X with respect to U what did +we hold constant we held the constant in + + align:start position:0% +we hold constant we held the constant in + + + align:start position:0% +we hold constant we held the constant in +other words I'm not going to keep this + + align:start position:0% +other words I'm not going to keep this + + + align:start position:0% +other words I'm not going to keep this +habit up very long but just for the time + + align:start position:0% +habit up very long but just for the time + + + align:start position:0% +habit up very long but just for the time +being I would like you to get used to + + align:start position:0% +being I would like you to get used to + + + align:start position:0% +being I would like you to get used to +the idea of putting in as a subscript + + align:start position:0% +the idea of putting in as a subscript + + + align:start position:0% +the idea of putting in as a subscript +the variables that are being held + + align:start position:0% +the variables that are being held + + + align:start position:0% +the variables that are being held +constant you see in the textbook when + + align:start position:0% +constant you see in the textbook when + + + align:start position:0% +constant you see in the textbook when +they say this is the case what they + + align:start position:0% +they say this is the case what they + + + align:start position:0% +they say this is the case what they +really mean is if you differentiate U + + align:start position:0% +really mean is if you differentiate U + + + align:start position:0% +really mean is if you differentiate U +with respect to X holding y constant + + align:start position:0% +with respect to X holding y constant + + + align:start position:0% +with respect to X holding y constant +that in general will not be the + + align:start position:0% +that in general will not be the + + + align:start position:0% +that in general will not be the +reciprocal of the derivative of x with + + align:start position:0% +reciprocal of the derivative of x with + + + align:start position:0% +reciprocal of the derivative of x with +respect to U holding V constant so I can + + align:start position:0% +respect to U holding V constant so I can + + + align:start position:0% +respect to U holding V constant so I can +cross out the the question mark now but + + align:start position:0% +cross out the the question mark now but + + + align:start position:0% +cross out the the question mark now but +the point is notice that the variables + + align:start position:0% +the point is notice that the variables + + + align:start position:0% +the point is notice that the variables +that you're holding constant here are + + align:start position:0% +that you're holding constant here are + + + align:start position:0% +that you're holding constant here are +different you see suppose instead I took + + align:start position:0% +different you see suppose instead I took + + + align:start position:0% +different you see suppose instead I took +the partial of X with respect to U + + align:start position:0% +the partial of X with respect to U + + + align:start position:0% +the partial of X with respect to U +holding y constant in other words + + align:start position:0% +holding y constant in other words + + + align:start position:0% +holding y constant in other words +suppose I solve for x in terms of U and + + align:start position:0% +suppose I solve for x in terms of U and + + + align:start position:0% +suppose I solve for x in terms of U and +Y that happens to be very easy to do + + align:start position:0% +Y that happens to be very easy to do + + + align:start position:0% +Y that happens to be very easy to do +here if given that U equal x + y it + + align:start position:0% +here if given that U equal x + y it + + + align:start position:0% +here if given that U equal x + y it +follows immediately that X is equal to + + align:start position:0% +follows immediately that X is equal to + + + align:start position:0% +follows immediately that X is equal to +uus Y now if I take the partial of X + + align:start position:0% +uus Y now if I take the partial of X + + + align:start position:0% +uus Y now if I take the partial of X +with respect to U treating y as a + + align:start position:0% +with respect to U treating y as a + + + align:start position:0% +with respect to U treating y as a +constant + + align:start position:0% +constant + + + align:start position:0% +constant +so let me do that what do I get for an + + align:start position:0% +so let me do that what do I get for an + + + align:start position:0% +so let me do that what do I get for an +answer I get one for an answer in other + + align:start position:0% +answer I get one for an answer in other + + + align:start position:0% +answer I get one for an answer in other +words the reciprocal of the partial of X + + align:start position:0% +words the reciprocal of the partial of X + + + align:start position:0% +words the reciprocal of the partial of X +with respect to you treating y as a + + align:start position:0% +with respect to you treating y as a + + + align:start position:0% +with respect to you treating y as a +constant as as the other independent + + align:start position:0% +constant as as the other independent + + + align:start position:0% +constant as as the other independent +variable is equal to the partial of U + + align:start position:0% +variable is equal to the partial of U + + + align:start position:0% +variable is equal to the partial of U +respect to X when it's also y That's + + align:start position:0% +respect to X when it's also y That's + + + align:start position:0% +respect to X when it's also y That's +being considered as the other variable + + align:start position:0% +being considered as the other variable + + + align:start position:0% +being considered as the other variable +when the variables outside here match up + + align:start position:0% +when the variables outside here match up + + + align:start position:0% +when the variables outside here match up +the recipes work course that leads to + + align:start position:0% +the recipes work course that leads to + + + align:start position:0% +the recipes work course that leads to +the question then why do the textbooks + + align:start position:0% +the question then why do the textbooks + + + align:start position:0% +the question then why do the textbooks +tell you that this isn't true why do + + align:start position:0% +tell you that this isn't true why do + + + align:start position:0% +tell you that this isn't true why do +they pick this particular representation + + align:start position:0% +they pick this particular representation + + + align:start position:0% +they pick this particular representation +rather than this one and I have a + + align:start position:0% +rather than this one and I have a + + + align:start position:0% +rather than this one and I have a +combination example and explanation here + + align:start position:0% +combination example and explanation here + + + align:start position:0% +combination example and explanation here +and it's simply this let's suppose I was + + align:start position:0% +and it's simply this let's suppose I was + + + align:start position:0% +and it's simply this let's suppose I was +given that wal e to x + y * cosine x - y + + align:start position:0% +given that wal e to x + y * cosine x - y + + + align:start position:0% +given that wal e to x + y * cosine x - y +it seems that since the only way the + + align:start position:0% +it seems that since the only way the + + + align:start position:0% +it seems that since the only way the +variable appears in the first factor is + + align:start position:0% +variable appears in the first factor is + + + align:start position:0% +variable appears in the first factor is +is as x + y and the only way it appears + + align:start position:0% +is as x + y and the only way it appears + + + align:start position:0% +is as x + y and the only way it appears +in the second factor is in the form xus + + align:start position:0% +in the second factor is in the form xus + + + align:start position:0% +in the second factor is in the form xus +y a very natural substitution might be + + align:start position:0% +y a very natural substitution might be + + + align:start position:0% +y a very natural substitution might be +to say let U equal x + y and v = xus y + + align:start position:0% +to say let U equal x + y and v = xus y + + + align:start position:0% +to say let U equal x + y and v = xus y +in other words I could either visualize + + align:start position:0% +in other words I could either visualize + + + align:start position:0% +in other words I could either visualize +W as being a function of X and Y in + + align:start position:0% +W as being a function of X and Y in + + + align:start position:0% +W as being a function of X and Y in +which case it would be e to x + y * + + align:start position:0% +which case it would be e to x + y * + + + align:start position:0% +which case it would be e to x + y * +cosine x - y or I could visualize W as + + align:start position:0% +cosine x - y or I could visualize W as + + + align:start position:0% +cosine x - y or I could visualize W as +being a simpler function of the two new + + align:start position:0% +being a simpler function of the two new + + + align:start position:0% +being a simpler function of the two new +variables u and v with W is then just + + align:start position:0% +variables u and v with W is then just + + + align:start position:0% +variables u and v with W is then just +what e to U * cosine V notice again that + + align:start position:0% +what e to U * cosine V notice again that + + + align:start position:0% +what e to U * cosine V notice again that +this formula here is much simpler than + + align:start position:0% +this formula here is much simpler than + + + align:start position:0% +this formula here is much simpler than +this one this one says what take e to + + align:start position:0% +this one this one says what take e to + + + align:start position:0% +this one this one says what take e to +the sum of these two multipli by the + + align:start position:0% +the sum of these two multipli by the + + + align:start position:0% +the sum of these two multipli by the +cosine of the difference of these two + + align:start position:0% +cosine of the difference of these two + + + align:start position:0% +cosine of the difference of these two +and this one just says what take e to + + align:start position:0% +and this one just says what take e to + + + align:start position:0% +and this one just says what take e to +the 1 times the cosine of the second but + + align:start position:0% +the 1 times the cosine of the second but + + + align:start position:0% +the 1 times the cosine of the second but +the point is that you might make this + + align:start position:0% +the point is that you might make this + + + align:start position:0% +the point is that you might make this +change of variables to simplify your + + align:start position:0% +change of variables to simplify your + + + align:start position:0% +change of variables to simplify your +computations the point is that either we + + align:start position:0% +computations the point is that either we + + + align:start position:0% +computations the point is that either we +would treat W as a function of X and Y + + align:start position:0% +would treat W as a function of X and Y + + + align:start position:0% +would treat W as a function of X and Y +or we would have treated W as a function + + align:start position:0% +or we would have treated W as a function + + + align:start position:0% +or we would have treated W as a function +of u and v and by way notice here my use + + align:start position:0% +of u and v and by way notice here my use + + + align:start position:0% +of u and v and by way notice here my use +of f and g notice that f is a that W is + + align:start position:0% +of f and g notice that f is a that W is + + + align:start position:0% +of f and g notice that f is a that W is +a different function of X and Y than it + + align:start position:0% +a different function of X and Y than it + + + align:start position:0% +a different function of X and Y than it +is of u and v but this notation says + + align:start position:0% +is of u and v but this notation says + + + align:start position:0% +is of u and v but this notation says +what we can consider W either in terms + + align:start position:0% +what we can consider W either in terms + + + align:start position:0% +what we can consider W either in terms +of X and Y or in terms of u and v hardly + + align:start position:0% +of X and Y or in terms of u and v hardly + + + align:start position:0% +of X and Y or in terms of u and v hardly +ever would we consider W as a function + + align:start position:0% +ever would we consider W as a function + + + align:start position:0% +ever would we consider W as a function +of U and Y in other words either we + + align:start position:0% +of U and Y in other words either we + + + align:start position:0% +of U and Y in other words either we +would change the variables or we don't + + align:start position:0% +would change the variables or we don't + + + align:start position:0% +would change the variables or we don't +oh for example in terms of polar versus + + align:start position:0% +oh for example in terms of polar versus + + + align:start position:0% +oh for example in terms of polar versus +cartisian coordinates either we use X + + align:start position:0% +cartisian coordinates either we use X + + + align:start position:0% +cartisian coordinates either we use X +and Y or we use R in Theta we don't + + align:start position:0% +and Y or we use R in Theta we don't + + + align:start position:0% +and Y or we use R in Theta we don't +usually use R in X other words going + + align:start position:0% +usually use R in X other words going + + + align:start position:0% +usually use R in X other words going +back to the textbook example again if we + + align:start position:0% +back to the textbook example again if we + + + align:start position:0% +back to the textbook example again if we +look at this particular situation here + + align:start position:0% +look at this particular situation here + + + align:start position:0% +look at this particular situation here +all the book is saying is look at when + + align:start position:0% +all the book is saying is look at when + + + align:start position:0% +all the book is saying is look at when +you're differentiating with respect to X + + align:start position:0% +you're differentiating with respect to X + + + align:start position:0% +you're differentiating with respect to X +you usually mean that Y is the variable + + align:start position:0% +you usually mean that Y is the variable + + + align:start position:0% +you usually mean that Y is the variable +being held constant when we + + align:start position:0% +being held constant when we + + + align:start position:0% +being held constant when we +differentiate with respect to U you + + align:start position:0% +differentiate with respect to U you + + + align:start position:0% +differentiate with respect to U you +usually mean that V is the variable + + align:start position:0% +usually mean that V is the variable + + + align:start position:0% +usually mean that V is the variable +that's being held constant again more of + + align:start position:0% +that's being held constant again more of + + + align:start position:0% +that's being held constant again more of +this is said in our exercises but for + + align:start position:0% +this is said in our exercises but for + + + align:start position:0% +this is said in our exercises but for +the time being I want you to see how + + align:start position:0% +the time being I want you to see how + + + align:start position:0% +the time being I want you to see how +important it is when you have several + + align:start position:0% +important it is when you have several + + + align:start position:0% +important it is when you have several +variables to keep track of which are the + + align:start position:0% +variables to keep track of which are the + + + align:start position:0% +variables to keep track of which are the +dependent variables which are the + + align:start position:0% +dependent variables which are the + + + align:start position:0% +dependent variables which are the +independent variables and how they're + + align:start position:0% +independent variables and how they're + + + align:start position:0% +independent variables and how they're +coupled I said earlier that one of the + + align:start position:0% +coupled I said earlier that one of the + + + align:start position:0% +coupled I said earlier that one of the +nice things about picking n equals 2 is + + align:start position:0% +nice things about picking n equals 2 is + + + align:start position:0% +nice things about picking n equals 2 is +that you can draw a nice picture of the + + align:start position:0% +that you can draw a nice picture of the + + + align:start position:0% +that you can draw a nice picture of the +situation and what I thought you might + + align:start position:0% +situation and what I thought you might + + + align:start position:0% +situation and what I thought you might +like to see is the following let's + + align:start position:0% +like to see is the following let's + + + align:start position:0% +like to see is the following let's +suppose you have the W is some function + + align:start position:0% +suppose you have the W is some function + + + align:start position:0% +suppose you have the W is some function +of X and Y what that means is we can + + align:start position:0% +of X and Y what that means is we can + + + align:start position:0% +of X and Y what that means is we can +locate for a given value of x and a + + align:start position:0% +locate for a given value of x and a + + + align:start position:0% +locate for a given value of x and a +given value of y in other words for xal + + align:start position:0% +given value of y in other words for xal + + + align:start position:0% +given value of y in other words for xal +x0 yal y0 we you can think of the point + + align:start position:0% +x0 yal y0 we you can think of the point + + + align:start position:0% +x0 yal y0 we you can think of the point +x0 y0 as being in the XY plane W which + + align:start position:0% +x0 y0 as being in the XY plane W which + + + align:start position:0% +x0 y0 as being in the XY plane W which +is f of x0 y0 is just the height to this + + align:start position:0% +is f of x0 y0 is just the height to this + + + align:start position:0% +is f of x0 y0 is just the height to this +particular surface in other words if I + + align:start position:0% +particular surface in other words if I + + + align:start position:0% +particular surface in other words if I +let F of x0 y0 be called w0 notice that + + align:start position:0% +let F of x0 y0 be called w0 notice that + + + align:start position:0% +let F of x0 y0 be called w0 notice that +the function f ofx y at the point x = x0 + + align:start position:0% +the function f ofx y at the point x = x0 + + + align:start position:0% +the function f ofx y at the point x = x0 +y = y0 graphically corresponds to the + + align:start position:0% +y = y0 graphically corresponds to the + + + align:start position:0% +y = y0 graphically corresponds to the +point whose coordinates are x0 y Z and + + align:start position:0% +point whose coordinates are x0 y Z and + + + align:start position:0% +point whose coordinates are x0 y Z and +w0 okay this is now a surface and in the + + align:start position:0% +w0 okay this is now a surface and in the + + + align:start position:0% +w0 okay this is now a surface and in the +same way that we use tangent lines to + + align:start position:0% +same way that we use tangent lines to + + + align:start position:0% +same way that we use tangent lines to +replace curves when we had one + + align:start position:0% +replace curves when we had one + + + align:start position:0% +replace curves when we had one +independent variable in two independent + + align:start position:0% +independent variable in two independent + + + align:start position:0% +independent variable in two independent +variables we use tangent planes to in to + + align:start position:0% +variables we use tangent planes to in to + + + align:start position:0% +variables we use tangent planes to in to +replace surfaces the question that comes + + align:start position:0% +replace surfaces the question that comes + + + align:start position:0% +replace surfaces the question that comes +up is how do you get a tangent plane and + + align:start position:0% +up is how do you get a tangent plane and + + + align:start position:0% +up is how do you get a tangent plane and +what does this have to do with the + + align:start position:0% +what does this have to do with the + + + align:start position:0% +what does this have to do with the +partial derivatives and what I'd like to + + align:start position:0% +partial derivatives and what I'd like to + + + align:start position:0% +partial derivatives and what I'd like to +show you was the following first of all + + align:start position:0% +show you was the following first of all + + + align:start position:0% +show you was the following first of all +one very natural way of intersecting + + align:start position:0% +one very natural way of intersecting + + + align:start position:0% +one very natural way of intersecting +this surface with a plane in other words + + align:start position:0% +this surface with a plane in other words + + + align:start position:0% +this surface with a plane in other words +when you take the partial of w with + + align:start position:0% +when you take the partial of w with + + + align:start position:0% +when you take the partial of w with +respect to Y you holding x constant + + align:start position:0% +respect to Y you holding x constant + + + align:start position:0% +respect to Y you holding x constant +you're saying let x equal x0 notice that + + align:start position:0% +you're saying let x equal x0 notice that + + + align:start position:0% +you're saying let x equal x0 notice that +in three-dimensional space xal x0 is the + + align:start position:0% +in three-dimensional space xal x0 is the + + + align:start position:0% +in three-dimensional space xal x0 is the +equation of this plane and this plane + + align:start position:0% +equation of this plane and this plane + + + align:start position:0% +equation of this plane and this plane +see what is the the plane xal x0 it's + + align:start position:0% +see what is the the plane xal x0 it's + + + align:start position:0% +see what is the the plane xal x0 it's +the plane that goes through the line X = + + align:start position:0% +the plane that goes through the line X = + + + align:start position:0% +the plane that goes through the line X = +x0 parallel to the Wy plane This Plane + + align:start position:0% +x0 parallel to the Wy plane This Plane + + + align:start position:0% +x0 parallel to the Wy plane This Plane +intersects my Surface in a particular + + align:start position:0% +intersects my Surface in a particular + + + align:start position:0% +intersects my Surface in a particular +curve that curve passes through P0 I can + + align:start position:0% +curve that curve passes through P0 I can + + + align:start position:0% +curve that curve passes through P0 I can +talk about the slope of the curve at + + align:start position:0% +talk about the slope of the curve at + + + align:start position:0% +talk about the slope of the curve at +that particular Point okay in a similar + + align:start position:0% +that particular Point okay in a similar + + + align:start position:0% +that particular Point okay in a similar +way I could have sliced this Surface by + + align:start position:0% +way I could have sliced this Surface by + + + align:start position:0% +way I could have sliced this Surface by +a the plane yal y0 in other words hold y + + align:start position:0% +a the plane yal y0 in other words hold y + + + align:start position:0% +a the plane yal y0 in other words hold y +constant where you see to hold y + + align:start position:0% +constant where you see to hold y + + + align:start position:0% +constant where you see to hold y +constant that means I again draw my + + align:start position:0% +constant that means I again draw my + + + align:start position:0% +constant that means I again draw my +plane it intersects the surface in a + + align:start position:0% +plane it intersects the surface in a + + + align:start position:0% +plane it intersects the surface in a +different curve but that curve must also + + align:start position:0% +different curve but that curve must also + + + align:start position:0% +different curve but that curve must also +go through the point p 0 this this the + + align:start position:0% +go through the point p 0 this this the + + + align:start position:0% +go through the point p 0 this this the +same p 0 that's over here because after + + align:start position:0% +same p 0 that's over here because after + + + align:start position:0% +same p 0 that's over here because after +all the point on the surface that is + + align:start position:0% +all the point on the surface that is + + + align:start position:0% +all the point on the surface that is +directly above x0 y0 is p 0 and that + + align:start position:0% +directly above x0 y0 is p 0 and that + + + align:start position:0% +directly above x0 y0 is p 0 and that +point doesn't change no matter what + + align:start position:0% +point doesn't change no matter what + + + align:start position:0% +point doesn't change no matter what +plane you slice this thing with okay and + + align:start position:0% +plane you slice this thing with okay and + + + align:start position:0% +plane you slice this thing with okay and +so again I can talk about the slope of + + align:start position:0% +so again I can talk about the slope of + + + align:start position:0% +so again I can talk about the slope of +the tangent to this particular curve of + + align:start position:0% +the tangent to this particular curve of + + + align:start position:0% +the tangent to this particular curve of +intersection by the way one very brief + + align:start position:0% +intersection by the way one very brief + + + align:start position:0% +intersection by the way one very brief +aside before I continue on with this one + + align:start position:0% +aside before I continue on with this one + + + align:start position:0% +aside before I continue on with this one +of the things that makes functions of + + align:start position:0% +of the things that makes functions of + + + align:start position:0% +of the things that makes functions of +several variables so difficult is I + + align:start position:0% +several variables so difficult is I + + + align:start position:0% +several variables so difficult is I +would like you to observe because this + + align:start position:0% +would like you to observe because this + + + align:start position:0% +would like you to observe because this +will become the backbone of our future + + align:start position:0% +will become the backbone of our future + + + align:start position:0% +will become the backbone of our future +investigations that these two particular + + align:start position:0% +investigations that these two particular + + + align:start position:0% +investigations that these two particular +planes that I drew to intersect my + + align:start position:0% +planes that I drew to intersect my + + + align:start position:0% +planes that I drew to intersect my +Surface were very special planes one of + + align:start position:0% +Surface were very special planes one of + + + align:start position:0% +Surface were very special planes one of +them was par they both went through the + + align:start position:0% +them was par they both went through the + + + align:start position:0% +them was par they both went through the +point x0 y0 but one happened to be + + align:start position:0% +point x0 y0 but one happened to be + + + align:start position:0% +point x0 y0 but one happened to be +parallel to the Wy plane and the other + + align:start position:0% +parallel to the Wy plane and the other + + + align:start position:0% +parallel to the Wy plane and the other +one happened to be parallel to the WX + + align:start position:0% +one happened to be parallel to the WX + + + align:start position:0% +one happened to be parallel to the WX +plane notice that in + + align:start position:0% +plane notice that in + + + align:start position:0% +plane notice that in +general I could have passed infinitely + + align:start position:0% +general I could have passed infinitely + + + align:start position:0% +general I could have passed infinitely +many different planes through x0 y0 Each + + align:start position:0% +many different planes through x0 y0 Each + + + align:start position:0% +many different planes through x0 y0 Each +of which would have intersected the + + align:start position:0% +of which would have intersected the + + + align:start position:0% +of which would have intersected the +surface at a in a different curve and + + align:start position:0% +surface at a in a different curve and + + + align:start position:0% +surface at a in a different curve and +this is what leads later to the more + + align:start position:0% +this is what leads later to the more + + + align:start position:0% +this is what leads later to the more +generalized concept of directional + + align:start position:0% +generalized concept of directional + + + align:start position:0% +generalized concept of directional +derivatives that we will talk about in + + align:start position:0% +derivatives that we will talk about in + + + align:start position:0% +derivatives that we will talk about in +more detail in our future lectures but I + + align:start position:0% +more detail in our future lectures but I + + + align:start position:0% +more detail in our future lectures but I +simply mention the wood now because in + + align:start position:0% +simply mention the wood now because in + + + align:start position:0% +simply mention the wood now because in +the reading material in this assignment + + align:start position:0% +the reading material in this assignment + + + align:start position:0% +the reading material in this assignment +some mention is made of directional + + align:start position:0% +some mention is made of directional + + + align:start position:0% +some mention is made of directional +derivatives in other words uh I want to + + align:start position:0% +derivatives in other words uh I want to + + + align:start position:0% +derivatives in other words uh I want to +point out that to take partial + + align:start position:0% +point out that to take partial + + + align:start position:0% +point out that to take partial +derivatives we are interested in two + + align:start position:0% +derivatives we are interested in two + + + align:start position:0% +derivatives we are interested in two +special directions even though there are + + align:start position:0% +special directions even though there are + + + align:start position:0% +special directions even though there are +other directions the question that comes + + align:start position:0% +other directions the question that comes + + + align:start position:0% +other directions the question that comes +up of course is where do the partials + + align:start position:0% +up of course is where do the partials + + + align:start position:0% +up of course is where do the partials +come in here and secondly knowing where + + align:start position:0% +come in here and secondly knowing where + + + align:start position:0% +come in here and secondly knowing where +the partials come up in here where do + + align:start position:0% +the partials come up in here where do + + + align:start position:0% +the partials come up in here where do +they uh use C how do we find the + + align:start position:0% +they uh use C how do we find the + + + align:start position:0% +they uh use C how do we find the +equation of a tangent plane and all I + + align:start position:0% +equation of a tangent plane and all I + + + align:start position:0% +equation of a tangent plane and all I +would like you to see from here is that + + align:start position:0% +would like you to see from here is that + + + align:start position:0% +would like you to see from here is that +I'm going to use the same old technique + + align:start position:0% +I'm going to use the same old technique + + + align:start position:0% +I'm going to use the same old technique +as always given these two tangent lines + + align:start position:0% +as always given these two tangent lines + + + align:start position:0% +as always given these two tangent lines +I am going to vectorize them I am then + + align:start position:0% +I am going to vectorize them I am then + + + align:start position:0% +I am going to vectorize them I am then +going to find the equation of the plane + + align:start position:0% +going to find the equation of the plane + + + align:start position:0% +going to find the equation of the plane +that passes through those two vectors to + + align:start position:0% +that passes through those two vectors to + + + align:start position:0% +that passes through those two vectors to +do that I'm going to have to find the + + align:start position:0% +do that I'm going to have to find the + + + align:start position:0% +do that I'm going to have to find the +normal to that plane Etc and I'm going + + align:start position:0% +normal to that plane Etc and I'm going + + + align:start position:0% +normal to that plane Etc and I'm going +to wind up with the equation of a + + align:start position:0% +to wind up with the equation of a + + + align:start position:0% +to wind up with the equation of a +tangent plane in more slow motion all + + align:start position:0% +tangent plane in more slow motion all + + + align:start position:0% +tangent plane in more slow motion all +I'm saying is if I now take this picture + + align:start position:0% +I'm saying is if I now take this picture + + + align:start position:0% +I'm saying is if I now take this picture +and draw it over here notice the + + align:start position:0% +and draw it over here notice the + + + align:start position:0% +and draw it over here notice the +representation it looks as if the curve + + align:start position:0% +representation it looks as if the curve + + + align:start position:0% +representation it looks as if the curve +that I get is in the Wy plane it's + + align:start position:0% +that I get is in the Wy plane it's + + + align:start position:0% +that I get is in the Wy plane it's +actually in a plane parallel to the W y + + align:start position:0% +actually in a plane parallel to the W y + + + align:start position:0% +actually in a plane parallel to the W y +plane characterized by x = x Sub 0 and + + align:start position:0% +plane characterized by x = x Sub 0 and + + + align:start position:0% +plane characterized by x = x Sub 0 and +by the way notice even though X = x0 was + + align:start position:0% +by the way notice even though X = x0 was + + + align:start position:0% +by the way notice even though X = x0 was +chosen so that x0 was fixed I hope it's + + align:start position:0% +chosen so that x0 was fixed I hope it's + + + align:start position:0% +chosen so that x0 was fixed I hope it's +clear to you that if I let x sub Z vary + + align:start position:0% +clear to you that if I let x sub Z vary + + + align:start position:0% +clear to you that if I let x sub Z vary +and I pick different values of X Sub 0 + + align:start position:0% +and I pick different values of X Sub 0 + + + align:start position:0% +and I pick different values of X Sub 0 +the curve that I get here will in + + align:start position:0% +the curve that I get here will in + + + align:start position:0% +the curve that I get here will in +general differ you see what I'm saying + + align:start position:0% +general differ you see what I'm saying + + + align:start position:0% +general differ you see what I'm saying +is if I take slices parallel to the Wy + + align:start position:0% +is if I take slices parallel to the Wy + + + align:start position:0% +is if I take slices parallel to the Wy +plane for a particular surface the + + align:start position:0% +plane for a particular surface the + + + align:start position:0% +plane for a particular surface the +slices that I get the shape will depend + + align:start position:0% +slices that I get the shape will depend + + + align:start position:0% +slices that I get the shape will depend +on what the particular value of x0 is + + align:start position:0% +on what the particular value of x0 is + + + align:start position:0% +on what the particular value of x0 is +but that's not the crucial issue right + + align:start position:0% +but that's not the crucial issue right + + + align:start position:0% +but that's not the crucial issue right +now the point that I'm driving at is if + + align:start position:0% +now the point that I'm driving at is if + + + align:start position:0% +now the point that I'm driving at is if +I now call this tangent if I vectorize + + align:start position:0% +I now call this tangent if I vectorize + + + align:start position:0% +I now call this tangent if I vectorize +the tangent line and call that V1 what + + align:start position:0% +the tangent line and call that V1 what + + + align:start position:0% +the tangent line and call that V1 what +does that tangent line look like first + + align:start position:0% +does that tangent line look like first + + + align:start position:0% +does that tangent line look like first +of all let's see what its slope is now + + align:start position:0% +of all let's see what its slope is now + + + align:start position:0% +of all let's see what its slope is now +again if you didn't see this over here + + align:start position:0% +again if you didn't see this over here + + + align:start position:0% +again if you didn't see this over here +and all I showed you was this diagram + + align:start position:0% +and all I showed you was this diagram + + + align:start position:0% +and all I showed you was this diagram +you would say hey that slope is just the + + align:start position:0% +you would say hey that slope is just the + + + align:start position:0% +you would say hey that slope is just the +derivative of w with respect to y but we + + align:start position:0% +derivative of w with respect to y but we + + + align:start position:0% +derivative of w with respect to y but we +write that the partial of w with respect + + align:start position:0% +write that the partial of w with respect + + + align:start position:0% +write that the partial of w with respect +to Y in deference to the fact that W is + + align:start position:0% +to Y in deference to the fact that W is + + + align:start position:0% +to Y in deference to the fact that W is +not a function of Y alone the W depends + + align:start position:0% +not a function of Y alone the W depends + + + align:start position:0% +not a function of Y alone the W depends +on both X and Y and the reason that we + + align:start position:0% +on both X and Y and the reason that we + + + align:start position:0% +on both X and Y and the reason that we +got this curve was that we fixed X at + + align:start position:0% +got this curve was that we fixed X at + + + align:start position:0% +got this curve was that we fixed X at +some particular value so this is really + + align:start position:0% +some particular value so this is really + + + align:start position:0% +some particular value so this is really +what not the not the derivative of w + + align:start position:0% +what not the not the derivative of w + + + align:start position:0% +what not the not the derivative of w +with respect to Y evaluated at yal y0 + + align:start position:0% +with respect to Y evaluated at yal y0 + + + align:start position:0% +with respect to Y evaluated at yal y0 +it's the partial of w with respect to Y + + align:start position:0% +it's the partial of w with respect to Y + + + align:start position:0% +it's the partial of w with respect to Y +evaluated at what x0 comma y0 + + align:start position:0% +evaluated at what x0 comma y0 + + + align:start position:0% +evaluated at what x0 comma y0 +all right at any rate now that we have + + align:start position:0% +all right at any rate now that we have + + + align:start position:0% +all right at any rate now that we have +the slope notice that the slope of a + + align:start position:0% +the slope notice that the slope of a + + + align:start position:0% +the slope notice that the slope of a +vector can always be viewed as the K + + align:start position:0% +vector can always be viewed as the K + + + align:start position:0% +vector can always be viewed as the K +component in this case the K component + + align:start position:0% +component in this case the K component + + + align:start position:0% +component in this case the K component +divided by the J component if I make the + + align:start position:0% +divided by the J component if I make the + + + align:start position:0% +divided by the J component if I make the +J component one the slope will just be + + align:start position:0% +J component one the slope will just be + + + align:start position:0% +J component one the slope will just be +the K component in other words a vector + + align:start position:0% +the K component in other words a vector + + + align:start position:0% +the K component in other words a vector +which is tangent to the curve and one + + align:start position:0% +which is tangent to the curve and one + + + align:start position:0% +which is tangent to the curve and one +that's easy to write down is J plus the + + align:start position:0% +that's easy to write down is J plus the + + + align:start position:0% +that's easy to write down is J plus the +partial of w with respect to Y evaluated + + align:start position:0% +partial of w with respect to Y evaluated + + + align:start position:0% +partial of w with respect to Y evaluated +x0 y0 time K and notice by the way that + + align:start position:0% +x0 y0 time K and notice by the way that + + + align:start position:0% +x0 y0 time K and notice by the way that +this is a + + align:start position:0% +this is a + + + align:start position:0% +this is a +number that once I take the partial + + align:start position:0% +number that once I take the partial + + + align:start position:0% +number that once I take the partial +derivative and evaluated at a point I + + align:start position:0% +derivative and evaluated at a point I + + + align:start position:0% +derivative and evaluated at a point I +have a number so this is what a constant + + align:start position:0% +have a number so this is what a constant + + + align:start position:0% +have a number so this is what a constant +Vector once x0 and y0 are fixed in a + + align:start position:0% +Vector once x0 and y0 are fixed in a + + + align:start position:0% +Vector once x0 and y0 are fixed in a +similar + + align:start position:0% +similar + + + align:start position:0% +similar +way my Vector V2 which is for my curve + + align:start position:0% +way my Vector V2 which is for my curve + + + align:start position:0% +way my Vector V2 which is for my curve +parallel to the WX plane the slope of + + align:start position:0% +parallel to the WX plane the slope of + + + align:start position:0% +parallel to the WX plane the slope of +that curve at the point p 0 is not D wdx + + align:start position:0% +that curve at the point p 0 is not D wdx + + + align:start position:0% +that curve at the point p 0 is not D wdx +it's the partial of w with respect to X + + align:start position:0% +it's the partial of w with respect to X + + + align:start position:0% +it's the partial of w with respect to X +evaluated x0 y0 again why because even + + align:start position:0% +evaluated x0 y0 again why because even + + + align:start position:0% +evaluated x0 y0 again why because even +though this looks like w is a function + + align:start position:0% +though this looks like w is a function + + + align:start position:0% +though this looks like w is a function +of X alone here it was only that way + + align:start position:0% +of X alone here it was only that way + + + align:start position:0% +of X alone here it was only that way +because we took the second variable and + + align:start position:0% +because we took the second variable and + + + align:start position:0% +because we took the second variable and +in a sense froze it at the value y0 at + + align:start position:0% +in a sense froze it at the value y0 at + + + align:start position:0% +in a sense froze it at the value y0 at +any rate in in analogous manner V2 turns + + align:start position:0% +any rate in in analogous manner V2 turns + + + align:start position:0% +any rate in in analogous manner V2 turns +out to be what Vector it's I plus the + + align:start position:0% +out to be what Vector it's I plus the + + + align:start position:0% +out to be what Vector it's I plus the +partial of w respect to X evaluated x0 y + + align:start position:0% +partial of w respect to X evaluated x0 y + + + align:start position:0% +partial of w respect to X evaluated x0 y +z time K in other words the slope is the + + align:start position:0% +z time K in other words the slope is the + + + align:start position:0% +z time K in other words the slope is the +partial of w with respect to X and it's + + align:start position:0% +partial of w with respect to X and it's + + + align:start position:0% +partial of w with respect to X and it's +in the ik plane in other words the xw + + align:start position:0% +in the ik plane in other words the xw + + + align:start position:0% +in the ik plane in other words the xw +plane now that I have my two vectors to + + align:start position:0% +plane now that I have my two vectors to + + + align:start position:0% +plane now that I have my two vectors to +find the plane that passes through them + + align:start position:0% +find the plane that passes through them + + + align:start position:0% +find the plane that passes through them +all I need is what the normal vector and + + align:start position:0% +all I need is what the normal vector and + + + align:start position:0% +all I need is what the normal vector and +a point in the plane well one of the + + align:start position:0% +a point in the plane well one of the + + + align:start position:0% +a point in the plane well one of the +nice things about having studied + + align:start position:0% +nice things about having studied + + + align:start position:0% +nice things about having studied +cartisian the cross product here is that + + align:start position:0% +cartisian the cross product here is that + + + align:start position:0% +cartisian the cross product here is that +I can now take the cross product of V1 + + align:start position:0% +I can now take the cross product of V1 + + + align:start position:0% +I can now take the cross product of V1 +and V2 sparing you the details remember + + align:start position:0% +and V2 sparing you the details remember + + + align:start position:0% +and V2 sparing you the details remember +what I do here I just write down I J K + + align:start position:0% +what I do here I just write down I J K + + + align:start position:0% +what I do here I just write down I J K +V1 has these components V2 has these + + align:start position:0% +V1 has these components V2 has these + + + align:start position:0% +V1 has these components V2 has these +these components I now expand this + + align:start position:0% +these components I now expand this + + + align:start position:0% +these components I now expand this +determinant in the usual way and I get + + align:start position:0% +determinant in the usual way and I get + + + align:start position:0% +determinant in the usual way and I get +what this particular Vector in other + + align:start position:0% +what this particular Vector in other + + + align:start position:0% +what this particular Vector in other +words the I component is the partial of + + align:start position:0% +words the I component is the partial of + + + align:start position:0% +words the I component is the partial of +w respect to X the J component is the + + align:start position:0% +w respect to X the J component is the + + + align:start position:0% +w respect to X the J component is the +partial of w respect to Y both evaluated + + align:start position:0% +partial of w respect to Y both evaluated + + + align:start position:0% +partial of w respect to Y both evaluated +at the point x0 y0 and the K component + + align:start position:0% +at the point x0 y0 and the K component + + + align:start position:0% +at the point x0 y0 and the K component +is minus one now to find the equation of + + align:start position:0% +is minus one now to find the equation of + + + align:start position:0% +is minus one now to find the equation of +a tangent plane all I have to do is what + + align:start position:0% +a tangent plane all I have to do is what + + + align:start position:0% +a tangent plane all I have to do is what +take the standard form of the plane in + + align:start position:0% +take the standard form of the plane in + + + align:start position:0% +take the standard form of the plane in +other words the coefficients will be the + + align:start position:0% +other words the coefficients will be the + + + align:start position:0% +other words the coefficients will be the +and then I take x0 y0 w0 which is a + + align:start position:0% +and then I take x0 y0 w0 which is a + + + align:start position:0% +and then I take x0 y0 w0 which is a +point in my plane and then the equation + + align:start position:0% +point in my plane and then the equation + + + align:start position:0% +point in my plane and then the equation +of the tangent plane becomes quite + + align:start position:0% +of the tangent plane becomes quite + + + align:start position:0% +of the tangent plane becomes quite +simply this expression here and in fact + + align:start position:0% +simply this expression here and in fact + + + align:start position:0% +simply this expression here and in fact +if I rewrite that notice I can transpose + + align:start position:0% +if I rewrite that notice I can transpose + + + align:start position:0% +if I rewrite that notice I can transpose +the wus w0 term that is the change in W + + align:start position:0% +the wus w0 term that is the change in W + + + align:start position:0% +the wus w0 term that is the change in W +but to remind us that we're in a tangent + + align:start position:0% +but to remind us that we're in a tangent + + + align:start position:0% +but to remind us that we're in a tangent +plane we don't write this as Delta w we + + align:start position:0% +plane we don't write this as Delta w we + + + align:start position:0% +plane we don't write this as Delta w we +write it as Delta W sub tan and notice + + align:start position:0% +write it as Delta W sub tan and notice + + + align:start position:0% +write it as Delta W sub tan and notice +that the ch in W to the tangent plane is + + align:start position:0% +that the ch in W to the tangent plane is + + + align:start position:0% +that the ch in W to the tangent plane is +just the partial of w respect to x * + + align:start position:0% +just the partial of w respect to x * + + + align:start position:0% +just the partial of w respect to x * +Delta X plus the partial of w respect to + + align:start position:0% +Delta X plus the partial of w respect to + + + align:start position:0% +Delta X plus the partial of w respect to +y * Delta Y and hopefully this starts to + + align:start position:0% +y * Delta Y and hopefully this starts to + + + align:start position:0% +y * Delta Y and hopefully this starts to +seem familiar to you this should almost + + align:start position:0% +seem familiar to you this should almost + + + align:start position:0% +seem familiar to you this should almost +look like the equation of Delta y tan + + align:start position:0% +look like the equation of Delta y tan + + + align:start position:0% +look like the equation of Delta y tan +only in two Dimensions remember we had + + align:start position:0% +only in two Dimensions remember we had + + + align:start position:0% +only in two Dimensions remember we had +Delta y Tan in part one of the course + + align:start position:0% +Delta y Tan in part one of the course + + + align:start position:0% +Delta y Tan in part one of the course +see what this really says is what this + + align:start position:0% +see what this really says is what this + + + align:start position:0% +see what this really says is what this +is the change in W with respect to X + + align:start position:0% +is the change in W with respect to X + + + align:start position:0% +is the change in W with respect to X +multiplied by the total change in X in + + align:start position:0% +multiplied by the total change in X in + + + align:start position:0% +multiplied by the total change in X in +other words this term is what it's the + + align:start position:0% +other words this term is what it's the + + + align:start position:0% +other words this term is what it's the +change in W due to the change in X alone + + align:start position:0% +change in W due to the change in X alone + + + align:start position:0% +change in W due to the change in X alone +this term is the change in W with + + align:start position:0% +this term is the change in W with + + + align:start position:0% +this term is the change in W with +respect to Y times the total change in y + + align:start position:0% +respect to Y times the total change in y + + + align:start position:0% +respect to Y times the total change in y +so this term tells you the change in W + + align:start position:0% +so this term tells you the change in W + + + align:start position:0% +so this term tells you the change in W +due to the change in y alone and if you + + align:start position:0% +due to the change in y alone and if you + + + align:start position:0% +due to the change in y alone and if you +add these two up since X and Y are + + align:start position:0% +add these two up since X and Y are + + + align:start position:0% +add these two up since X and Y are +independent this should give you the + + align:start position:0% +independent this should give you the + + + align:start position:0% +independent this should give you the +total change in W the reason of course + + align:start position:0% +total change in W the reason of course + + + align:start position:0% +total change in W the reason of course +that you don't get the total change in W + + align:start position:0% +that you don't get the total change in W + + + align:start position:0% +that you don't get the total change in W +but rather Delta W tan is the fact that + + align:start position:0% +but rather Delta W tan is the fact that + + + align:start position:0% +but rather Delta W tan is the fact that +if you if these Expressions here are not + + align:start position:0% +if you if these Expressions here are not + + + align:start position:0% +if you if these Expressions here are not +constant num numbers as Delta X and + + align:start position:0% +constant num numbers as Delta X and + + + align:start position:0% +constant num numbers as Delta X and +Delta y are varying these numbers here + + align:start position:0% +Delta y are varying these numbers here + + + align:start position:0% +Delta y are varying these numbers here +are varying these are variables but you + + align:start position:0% +are varying these are variables but you + + + align:start position:0% +are varying these are variables but you +see once you fix these at these values + + align:start position:0% +see once you fix these at these values + + + align:start position:0% +see once you fix these at these values +these become numbers and now you know + + align:start position:0% +these become numbers and now you know + + + align:start position:0% +these become numbers and now you know +what Delta wtan is now look at in some + + align:start position:0% +what Delta wtan is now look at in some + + + align:start position:0% +what Delta wtan is now look at in some +of the homework problems in the text + + align:start position:0% +of the homework problems in the text + + + align:start position:0% +of the homework problems in the text +what we're going to do is just practice + + align:start position:0% +what we're going to do is just practice + + + align:start position:0% +what we're going to do is just practice +the geometry itself we're going to find + + align:start position:0% +the geometry itself we're going to find + + + align:start position:0% +the geometry itself we're going to find +equations of tangent planes the thing + + align:start position:0% +equations of tangent planes the thing + + + align:start position:0% +equations of tangent planes the thing +that's very important to us in future + + align:start position:0% +that's very important to us in future + + + align:start position:0% +that's very important to us in future +lectures from a structural point of view + + align:start position:0% +lectures from a structural point of view + + + align:start position:0% +lectures from a structural point of view +is that the equation of the tangent + + align:start position:0% +is that the equation of the tangent + + + align:start position:0% +is that the equation of the tangent +plane in other words the equation for + + align:start position:0% +plane in other words the equation for + + + align:start position:0% +plane in other words the equation for +Delta W tan is far more simple to handle + + align:start position:0% +Delta W tan is far more simple to handle + + + align:start position:0% +Delta W tan is far more simple to handle +than the equation for the true Delta W + + align:start position:0% +than the equation for the true Delta W + + + align:start position:0% +than the equation for the true Delta W +you see the equation for Delta W tan + + align:start position:0% +you see the equation for Delta W tan + + + align:start position:0% +you see the equation for Delta W tan +just has Delta X and Delta y appearing + + align:start position:0% +just has Delta X and Delta y appearing + + + align:start position:0% +just has Delta X and Delta y appearing +to the first Power whereas if you try to + + align:start position:0% +to the first Power whereas if you try to + + + align:start position:0% +to the first Power whereas if you try to +find Delta W exactly for an arbitrary + + align:start position:0% +find Delta W exactly for an arbitrary + + + align:start position:0% +find Delta W exactly for an arbitrary +function of X and Y this be can become a + + align:start position:0% +function of X and Y this be can become a + + + align:start position:0% +function of X and Y this be can become a +very very messy thing in short Delta W10 + + align:start position:0% +very very messy thing in short Delta W10 + + + align:start position:0% +very very messy thing in short Delta W10 +will play for two and more independent + + align:start position:0% +will play for two and more independent + + + align:start position:0% +will play for two and more independent +variables the same role that Delta y + + align:start position:0% +variables the same role that Delta y + + + align:start position:0% +variables the same role that Delta y +suban played for us in part one of this + + align:start position:0% +suban played for us in part one of this + + + align:start position:0% +suban played for us in part one of this +course as a + + align:start position:0% +course as a + + + align:start position:0% +course as a +differential and what we'll be + + align:start position:0% +differential and what we'll be + + + align:start position:0% +differential and what we'll be +discussing next or at least trying to + + align:start position:0% +discussing next or at least trying to + + + align:start position:0% +discussing next or at least trying to +get at the root of is just what does + + align:start position:0% +get at the root of is just what does + + + align:start position:0% +get at the root of is just what does +play the role of a differential when + + align:start position:0% +play the role of a differential when + + + align:start position:0% +play the role of a differential when +you're dealing with Calculus of several + + align:start position:0% +you're dealing with Calculus of several + + + align:start position:0% +you're dealing with Calculus of several +variables and what we're going to find + + align:start position:0% +variables and what we're going to find + + + align:start position:0% +variables and what we're going to find +is that again the computations become + + align:start position:0% +is that again the computations become + + + align:start position:0% +is that again the computations become +messy enough so that even though the + + align:start position:0% +messy enough so that even though the + + + align:start position:0% +messy enough so that even though the +structure stays fairly nice there are + + align:start position:0% +structure stays fairly nice there are + + + align:start position:0% +structure stays fairly nice there are +some wrinkles that come out that will + + align:start position:0% +some wrinkles that come out that will + + + align:start position:0% +some wrinkles that come out that will +take us a considerable amount of time to + + align:start position:0% +take us a considerable amount of time to + + + align:start position:0% +take us a considerable amount of time to +untangle but we'll worry about that when + + align:start position:0% +untangle but we'll worry about that when + + + align:start position:0% +untangle but we'll worry about that when +the time comes and so until that time + + align:start position:0% + + + + align:start position:0% + +goodbye funding for the publication of + + align:start position:0% +goodbye funding for the publication of + + + align:start position:0% +goodbye funding for the publication of +this video was provided by the Gabriella + + align:start position:0% +this video was provided by the Gabriella + + + align:start position:0% +this video was provided by the Gabriella +and Paul rosenbom + + align:start position:0% +and Paul rosenbom + + + align:start position:0% +and Paul rosenbom +foundation help ocw continue to provide + + align:start position:0% +foundation help ocw continue to provide + + + align:start position:0% +foundation help ocw continue to provide +free and open access to MIT courses by + + align:start position:0% +free and open access to MIT courses by + + + align:start position:0% +free and open access to MIT courses by +making a donation at + + align:start position:0% + + + + align:start position:0% + +edu donate \ No newline at end of file diff --git a/VSqpYPgxcps.txt b/VSqpYPgxcps.txt new file mode 100644 index 0000000000000000000000000000000000000000..c450d00a2e47f81f5d7ffa88e292609f984d8730 --- /dev/null +++ b/VSqpYPgxcps.txt @@ -0,0 +1,12483 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or to view additional + + align:start position:0% +to make a donation or to view additional + + + align:start position:0% +to make a donation or to view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +hi everyone I'm in a very good mood + + align:start position:0% +hi everyone I'm in a very good mood + + + align:start position:0% +hi everyone I'm in a very good mood +today I nothing to do with the class but + + align:start position:0% +today I nothing to do with the class but + + + align:start position:0% +today I nothing to do with the class but +I'm having a baby so so that's kind of + + align:start position:0% +I'm having a baby so so that's kind of + + + align:start position:0% +I'm having a baby so so that's kind of +exciting + + align:start position:0% +exciting + + + align:start position:0% +exciting +so if I just start giggling you'll know + + align:start position:0% +so if I just start giggling you'll know + + + align:start position:0% +so if I just start giggling you'll know +why and then six months if I just + + align:start position:0% +why and then six months if I just + + + align:start position:0% +why and then six months if I just +weeping it on the ground you'll also + + align:start position:0% +weeping it on the ground you'll also + + + align:start position:0% +weeping it on the ground you'll also +know why so so today we're gonna do two + + align:start position:0% +know why so so today we're gonna do two + + + align:start position:0% +know why so so today we're gonna do two +things the first is we're going I'm + + align:start position:0% +things the first is we're going I'm + + + align:start position:0% +things the first is we're going I'm +gonna give you well the first is review + + align:start position:0% +gonna give you well the first is review + + + align:start position:0% +gonna give you well the first is review +a little bit of practice for the exam + + align:start position:0% +a little bit of practice for the exam + + + align:start position:0% +a little bit of practice for the exam +we're gonna have on Thursday let me tell + + align:start position:0% +we're gonna have on Thursday let me tell + + + align:start position:0% +we're gonna have on Thursday let me tell +you a little bit more about the exam the + + align:start position:0% +you a little bit more about the exam the + + + align:start position:0% +you a little bit more about the exam the +exam by the way has been rescheduled to + + align:start position:0% +exam by the way has been rescheduled to + + + align:start position:0% +exam by the way has been rescheduled to +be in six one twenty not in Walker gym + + align:start position:0% +be in six one twenty not in Walker gym + + + align:start position:0% +be in six one twenty not in Walker gym +so it's gonna be the usual place we're + + align:start position:0% +so it's gonna be the usual place we're + + + align:start position:0% +so it's gonna be the usual place we're +not moving and the reason is I'm + + align:start position:0% +not moving and the reason is I'm + + + align:start position:0% +not moving and the reason is I'm +changing the format on this exam in part + + align:start position:0% +changing the format on this exam in part + + + align:start position:0% +changing the format on this exam in part +to make it a little less of a burden to + + align:start position:0% +to make it a little less of a burden to + + + align:start position:0% +to make it a little less of a burden to +everyone but also in part because I've + + align:start position:0% +everyone but also in part because I've + + + align:start position:0% +everyone but also in part because I've +been struggling with the question of how + + align:start position:0% +been struggling with the question of how + + + align:start position:0% +been struggling with the question of how +to make the exam most useful the purpose + + align:start position:0% +to make the exam most useful the purpose + + + align:start position:0% +to make the exam most useful the purpose +of an exam like this is not to get get + + align:start position:0% +of an exam like this is not to get get + + + align:start position:0% +of an exam like this is not to get get +grades for you guys although that's an + + align:start position:0% +grades for you guys although that's an + + + align:start position:0% +grades for you guys although that's an +incidental by-product the purpose is to + + align:start position:0% +incidental by-product the purpose is to + + + align:start position:0% +incidental by-product the purpose is to +give you some feedback on how you're + + align:start position:0% +give you some feedback on how you're + + + align:start position:0% +give you some feedback on how you're +doing how you're command of the material + + align:start position:0% +doing how you're command of the material + + + align:start position:0% +doing how you're command of the material +has evolved and also to to help you sort + + align:start position:0% +has evolved and also to to help you sort + + + align:start position:0% +has evolved and also to to help you sort +of learn some of the things that you + + align:start position:0% +of learn some of the things that you + + + align:start position:0% +of learn some of the things that you +might not have mastered so the way the + + align:start position:0% +might not have mastered so the way the + + + align:start position:0% +might not have mastered so the way the +exam is gonna be structured it's gonna + + align:start position:0% +exam is gonna be structured it's gonna + + + align:start position:0% +exam is gonna be structured it's gonna +be about 50 minutes of short answer + + align:start position:0% +be about 50 minutes of short answer + + + align:start position:0% +be about 50 minutes of short answer +questions a couple of very short + + align:start position:0% +questions a couple of very short + + + align:start position:0% +questions a couple of very short +computations but mostly short answer + + align:start position:0% +computations but mostly short answer + + + align:start position:0% +computations but mostly short answer +questions on paper you'll hand those + + align:start position:0% +questions on paper you'll hand those + + + align:start position:0% +questions on paper you'll hand those +back and then we'll go over those + + align:start position:0% +back and then we'll go over those + + + align:start position:0% +back and then we'll go over those +questions in class afterwards okay so + + align:start position:0% +questions in class afterwards okay so + + + align:start position:0% +questions in class afterwards okay so +it's a relatively low pressure exam and + + align:start position:0% +it's a relatively low pressure exam and + + + align:start position:0% +it's a relatively low pressure exam and +it's mostly conceptual it will cover + + align:start position:0% +it's mostly conceptual it will cover + + + align:start position:0% +it's mostly conceptual it will cover +everything we've done through this last + + align:start position:0% +everything we've done through this last + + + align:start position:0% +everything we've done through this last +problem set today's the to the degree + + align:start position:0% +problem set today's the to the degree + + + align:start position:0% +problem set today's the to the degree +that we get to the lecture part of today + + align:start position:0% +that we get to the lecture part of today + + + align:start position:0% +that we get to the lecture part of today +after questions today's lecture will not + + align:start position:0% +after questions today's lecture will not + + + align:start position:0% +after questions today's lecture will not +be directly covered however it will be a + + align:start position:0% +be directly covered however it will be a + + + align:start position:0% +be directly covered however it will be a +fair game for the next midterm which + + align:start position:0% +fair game for the next midterm which + + + align:start position:0% +fair game for the next midterm which +would be more of a traditional midterm + + align:start position:0% +would be more of a traditional midterm + + + align:start position:0% +would be more of a traditional midterm +and that's coming in April so the + + align:start position:0% +and that's coming in April so the + + + align:start position:0% +and that's coming in April so the +structure of today is I'm going to give + + align:start position:0% +structure of today is I'm going to give + + + align:start position:0% +structure of today is I'm going to give +you a whole bunch of clicker questions + + align:start position:0% +you a whole bunch of clicker questions + + + align:start position:0% +you a whole bunch of clicker questions +so make sure you've got your clickers + + align:start position:0% +so make sure you've got your clickers + + + align:start position:0% +so make sure you've got your clickers +out and those clicker questions are + + align:start position:0% +out and those clicker questions are + + + align:start position:0% +out and those clicker questions are +going to give you a sense for the level + + align:start position:0% +going to give you a sense for the level + + + align:start position:0% +going to give you a sense for the level +and scope of the exam + + align:start position:0% +and scope of the exam + + + align:start position:0% +and scope of the exam +the exam will be a little harder than + + align:start position:0% +the exam will be a little harder than + + + align:start position:0% +the exam will be a little harder than +the clicker questions but not a whole + + align:start position:0% +the clicker questions but not a whole + + + align:start position:0% +the clicker questions but not a whole +lot and the difference is just that it's + + align:start position:0% +lot and the difference is just that it's + + + align:start position:0% +lot and the difference is just that it's +going to be on paper in front of you + + align:start position:0% +going to be on paper in front of you + + + align:start position:0% +going to be on paper in front of you +instead of you know clicker and thus + + align:start position:0% +instead of you know clicker and thus + + + align:start position:0% +instead of you know clicker and thus +that gives you a little more room to do + + align:start position:0% +that gives you a little more room to do + + + align:start position:0% +that gives you a little more room to do +calculations on a piece of paper short + + align:start position:0% +calculations on a piece of paper short + + + align:start position:0% +calculations on a piece of paper short +short calculations and then after that + + align:start position:0% +short calculations and then after that + + + align:start position:0% +short calculations and then after that +we'll we'll come on to some in some + + align:start position:0% +we'll we'll come on to some in some + + + align:start position:0% +we'll we'll come on to some in some +sense of a review but also an + + align:start position:0% +sense of a review but also an + + + align:start position:0% +sense of a review but also an +introduction to the Drakh bra ket + + align:start position:0% +introduction to the Drakh bra ket + + + align:start position:0% +introduction to the Drakh bra ket +notation that many of our textbooks use + + align:start position:0% +notation that many of our textbooks use + + + align:start position:0% +notation that many of our textbooks use +but that we haven't introduced in + + align:start position:0% +but that we haven't introduced in + + + align:start position:0% +but that we haven't introduced in +lecture so far okay any questions before + + align:start position:0% +lecture so far okay any questions before + + + align:start position:0% +lecture so far okay any questions before +you get started + + align:start position:0% + + + + align:start position:0% + +41 other questions I think there will + + align:start position:0% +41 other questions I think there will + + + align:start position:0% +41 other questions I think there will +probably not be a practice exam because + + align:start position:0% +probably not be a practice exam because + + + align:start position:0% +probably not be a practice exam because +of the shift in format today will + + align:start position:0% +of the shift in format today will + + + align:start position:0% +of the shift in format today will +basically be your practice exam okay if + + align:start position:0% +basically be your practice exam okay if + + + align:start position:0% +basically be your practice exam okay if +I can get my work together and get you + + align:start position:0% +I can get my work together and get you + + + align:start position:0% +I can get my work together and get you +guys a practice exam of the right format + + align:start position:0% +guys a practice exam of the right format + + + align:start position:0% +guys a practice exam of the right format +then maybe but it wouldn't even be all + + align:start position:0% +then maybe but it wouldn't even be all + + + align:start position:0% +then maybe but it wouldn't even be all +that useful is the problem so watch what + + align:start position:0% +that useful is the problem so watch what + + + align:start position:0% +that useful is the problem so watch what +happens today yep I will post the + + align:start position:0% +happens today yep I will post the + + + align:start position:0% +happens today yep I will post the +questions from today on the website yes + + align:start position:0% + + + + align:start position:0% + +I can tell you that but it's not gonna + + align:start position:0% +I can tell you that but it's not gonna + + + align:start position:0% +I can tell you that but it's not gonna +be a time trial okay you're not gonna be + + align:start position:0% +be a time trial okay you're not gonna be + + + align:start position:0% +be a time trial okay you're not gonna be +racing to get the you know it will + + align:start position:0% +racing to get the you know it will + + + align:start position:0% +racing to get the you know it will +because it to my mind part of the reason + + align:start position:0% +because it to my mind part of the reason + + + align:start position:0% +because it to my mind part of the reason +to or to design the exam this way is + + align:start position:0% +to or to design the exam this way is + + + align:start position:0% +to or to design the exam this way is +that it's testing your conceptual + + align:start position:0% +that it's testing your conceptual + + + align:start position:0% +that it's testing your conceptual +understanding which is the important + + align:start position:0% +understanding which is the important + + + align:start position:0% +understanding which is the important +thing so yeah it will be the questions + + align:start position:0% +thing so yeah it will be the questions + + + align:start position:0% +thing so yeah it will be the questions +alright so let's get started with the + + align:start position:0% +alright so let's get started with the + + + align:start position:0% +alright so let's get started with the +clicker part of today so do do we're on + + align:start position:0% +clicker part of today so do do we're on + + + align:start position:0% +clicker part of today so do do we're on +channel 41 okay + + align:start position:0% +channel 41 okay + + + align:start position:0% +channel 41 okay +so consider this eigenvalue equation two + + align:start position:0% +so consider this eigenvalue equation two + + + align:start position:0% +so consider this eigenvalue equation two +derivatives on f it's constant times f + + align:start position:0% +derivatives on f it's constant times f + + + align:start position:0% +derivatives on f it's constant times f +of X how many of these are eigen + + align:start position:0% +of X how many of these are eigen + + + align:start position:0% +of X how many of these are eigen +functions with the corresponding + + align:start position:0% +functions with the corresponding + + + align:start position:0% +functions with the corresponding +eigenvalue + + align:start position:0% + + + + align:start position:0% + +okay I've got about 10 seconds let's go + + align:start position:0% +okay I've got about 10 seconds let's go + + + align:start position:0% +okay I've got about 10 seconds let's go +ahead and put in your clicks + + align:start position:0% + + + + align:start position:0% + +okay and so your whoops oh sorry that + + align:start position:0% +okay and so your whoops oh sorry that + + + align:start position:0% +okay and so your whoops oh sorry that +just cleared your responses + + align:start position:0% +just cleared your responses + + + align:start position:0% +just cleared your responses +unfortunately the durian they're saved + + align:start position:0% +unfortunately the durian they're saved + + + align:start position:0% +unfortunately the durian they're saved +in memory just clear them off my screen + + align:start position:0% +in memory just clear them off my screen + + + align:start position:0% +in memory just clear them off my screen +so the response is here we go that + + align:start position:0% +so the response is here we go that + + + align:start position:0% +so the response is here we go that +didn't work + + align:start position:0% +didn't work + + + align:start position:0% +didn't work +Wow it just totally disappeared how did + + align:start position:0% +Wow it just totally disappeared how did + + + align:start position:0% +Wow it just totally disappeared how did +that happen + + align:start position:0% +that happen + + + align:start position:0% +that happen +wow that's so weird oh no that didn't + + align:start position:0% +wow that's so weird oh no that didn't + + + align:start position:0% +wow that's so weird oh no that didn't +work let's try this + + align:start position:0% +work let's try this + + + align:start position:0% +work let's try this +where did it go ah there it is + + align:start position:0% +where did it go ah there it is + + + align:start position:0% +where did it go ah there it is +whoa this is all very confusing okay + + align:start position:0% +whoa this is all very confusing okay + + + align:start position:0% +whoa this is all very confusing okay +this one so that that was your response + + align:start position:0% +this one so that that was your response + + + align:start position:0% +this one so that that was your response +B and C 63 and 38% so let's go back to + + align:start position:0% +B and C 63 and 38% so let's go back to + + + align:start position:0% +B and C 63 and 38% so let's go back to +this so quickly discuss this with your + + align:start position:0% +this so quickly discuss this with your + + + align:start position:0% +this so quickly discuss this with your +neighbor + + align:start position:0% + + + + align:start position:0% + +okay and now go ahead and click in your + + align:start position:0% +okay and now go ahead and click in your + + + align:start position:0% +okay and now go ahead and click in your +new answers if you you can keep talking + + align:start position:0% +new answers if you you can keep talking + + + align:start position:0% +new answers if you you can keep talking +that's fine + + align:start position:0% + + + + align:start position:0% + +okay another five seconds awesome + + align:start position:0% +okay another five seconds awesome + + + align:start position:0% +okay another five seconds awesome +okay that's it so the answer is B and + + align:start position:0% +okay that's it so the answer is B and + + + align:start position:0% +okay that's it so the answer is B and +99% of y'all got that I suspect someone + + align:start position:0% +99% of y'all got that I suspect someone + + + align:start position:0% +99% of y'all got that I suspect someone +didn't click okay good + + align:start position:0% +didn't click okay good + + + align:start position:0% +didn't click okay good +next question so I want insight to our + + align:start position:0% +next question so I want insight to our + + + align:start position:0% +next question so I want insight to our +two solutions of the Schrodinger + + align:start position:0% +two solutions of the Schrodinger + + + align:start position:0% +two solutions of the Schrodinger +equation is the sum of the two of them + + align:start position:0% +equation is the sum of the two of them + + + align:start position:0% +equation is the sum of the two of them +with coefficients a and B also a + + align:start position:0% +with coefficients a and B also a + + + align:start position:0% +with coefficients a and B also a +solution of the Schrodinger equation oh + + align:start position:0% +solution of the Schrodinger equation oh + + + align:start position:0% +solution of the Schrodinger equation oh +and I forgot to start the clicky thingy + + align:start position:0% +and I forgot to start the clicky thingy + + + align:start position:0% +and I forgot to start the clicky thingy +so click now oh yeah it is supposed to + + align:start position:0% +so click now oh yeah it is supposed to + + + align:start position:0% +so click now oh yeah it is supposed to +say psi 2 it says B Saito on the next + + align:start position:0% +say psi 2 it says B Saito on the next + + + align:start position:0% +say psi 2 it says B Saito on the next +sorry it's a Sai 1 plus psi 1 it should + + align:start position:0% +sorry it's a Sai 1 plus psi 1 it should + + + align:start position:0% +sorry it's a Sai 1 plus psi 1 it should +say Sai 1 plus psi 2 thank you + + align:start position:0% + + + + align:start position:0% + +yeah with the same potential yeah yeah + + align:start position:0% +yeah with the same potential yeah yeah + + + align:start position:0% +yeah with the same potential yeah yeah +[Laughter] + + align:start position:0% +[Laughter] + + + align:start position:0% +[Laughter] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Wow + + align:start position:0% +Wow + + + align:start position:0% +Wow +yeah so you know Einstein said God + + align:start position:0% +yeah so you know Einstein said God + + + align:start position:0% +yeah so you know Einstein said God +didn't play dice and let me paraphrase + + align:start position:0% +didn't play dice and let me paraphrase + + + align:start position:0% +didn't play dice and let me paraphrase +that is God doesn't mess with you and + + align:start position:0% +that is God doesn't mess with you and + + + align:start position:0% +that is God doesn't mess with you and +clicker question yeah okay and and you + + align:start position:0% +clicker question yeah okay and and you + + + align:start position:0% +clicker question yeah okay and and you +guys have effectively universally that + + align:start position:0% +guys have effectively universally that + + + align:start position:0% +guys have effectively universally that +the answer is a yes the superposition + + align:start position:0% +the answer is a yes the superposition + + + align:start position:0% +the answer is a yes the superposition +principle okay next question is going to + + align:start position:0% +principle okay next question is going to + + + align:start position:0% +principle okay next question is going to +be for answer here we go + + align:start position:0% +be for answer here we go + + + align:start position:0% +be for answer here we go +consider an infinite square well with + + align:start position:0% +consider an infinite square well with + + + align:start position:0% +consider an infinite square well with +with a and compared to the infinite + + align:start position:0% +with a and compared to the infinite + + + align:start position:0% +with a and compared to the infinite +square well with with a the ground state + + align:start position:0% +square well with with a the ground state + + + align:start position:0% +square well with with a the ground state +of a finite well is lower higher same + + align:start position:0% +of a finite well is lower higher same + + + align:start position:0% +of a finite well is lower higher same +energy or undetermined + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +you've got ten seconds so continue + + align:start position:0% +you've got ten seconds so continue + + + align:start position:0% +you've got ten seconds so continue +thinking through this five seconds okay + + align:start position:0% +thinking through this five seconds okay + + + align:start position:0% +thinking through this five seconds okay +and you mostly got it but have a quick + + align:start position:0% +and you mostly got it but have a quick + + + align:start position:0% +and you mostly got it but have a quick +chat with the person next to you + + align:start position:0% + + + + align:start position:0% + +all right let's try again it's such a + + align:start position:0% +all right let's try again it's such a + + + align:start position:0% +all right let's try again it's such a +good technique um I read another five + + align:start position:0% +good technique um I read another five + + + align:start position:0% +good technique um I read another five +seconds to put in your answer four three + + align:start position:0% +seconds to put in your answer four three + + + align:start position:0% +seconds to put in your answer four three +two one okay and you virtually all got + + align:start position:0% +two one okay and you virtually all got + + + align:start position:0% +two one okay and you virtually all got +it right they lower energy and let's + + align:start position:0% +it right they lower energy and let's + + + align:start position:0% +it right they lower energy and let's +just think about this intuitively + + align:start position:0% +just think about this intuitively + + + align:start position:0% +just think about this intuitively +intuitively the the gradient of the + + align:start position:0% +intuitively the the gradient of the + + + align:start position:0% +intuitively the the gradient of the +potential is a force right so in the + + align:start position:0% +potential is a force right so in the + + + align:start position:0% +potential is a force right so in the +second case you've got less force + + align:start position:0% +second case you've got less force + + + align:start position:0% +second case you've got less force +cramming the particle inside the box so + + align:start position:0% +cramming the particle inside the box so + + + align:start position:0% +cramming the particle inside the box so +it's being squeezed less tightly more + + align:start position:0% +it's being squeezed less tightly more + + + align:start position:0% +it's being squeezed less tightly more +physically you see that there was an + + align:start position:0% +physically you see that there was an + + + align:start position:0% +physically you see that there was an +evanescent tail on the outside what that + + align:start position:0% +evanescent tail on the outside what that + + + align:start position:0% +evanescent tail on the outside what that +tells you is the wave flux you didn't + + align:start position:0% +tells you is the wave flux you didn't + + + align:start position:0% +tells you is the wave flux you didn't +have to go to zero at the end it just + + align:start position:0% +have to go to zero at the end it just + + + align:start position:0% +have to go to zero at the end it just +had to get small and match on to a dying + + align:start position:0% +had to get small and match on to a dying + + + align:start position:0% +had to get small and match on to a dying +exponential right that's from the + + align:start position:0% +exponential right that's from the + + + align:start position:0% +exponential right that's from the +qualitative analysis of wave functions + + align:start position:0% +qualitative analysis of wave functions + + + align:start position:0% +qualitative analysis of wave functions +but meanwhile what that tells you is it + + align:start position:0% +but meanwhile what that tells you is it + + + align:start position:0% +but meanwhile what that tells you is it +has to curve less inside in order to + + align:start position:0% +has to curve less inside in order to + + + align:start position:0% +has to curve less inside in order to +have to get to zero it just has to get + + align:start position:0% +have to get to zero it just has to get + + + align:start position:0% +have to get to zero it just has to get +to a small value where matches to the + + align:start position:0% +to a small value where matches to the + + + align:start position:0% +to a small value where matches to the +decaying exponential so if the curvature + + align:start position:0% +decaying exponential so if the curvature + + + align:start position:0% +decaying exponential so if the curvature +is less than the energy is less cool + + align:start position:0% +is less than the energy is less cool + + + align:start position:0% +is less than the energy is less cool +okay next question + + align:start position:0% +okay next question + + + align:start position:0% +okay next question +or so any questions on that okay good + + align:start position:0% + + + + align:start position:0% + +time zero wavefunction infinite well + + align:start position:0% +time zero wavefunction infinite well + + + align:start position:0% +time zero wavefunction infinite well +with a is this sine squared with the + + align:start position:0% +with a is this sine squared with the + + + align:start position:0% +with a is this sine squared with the +normalization what's the wave function + + align:start position:0% +normalization what's the wave function + + + align:start position:0% +normalization what's the wave function +at a subsequent time T + + align:start position:0% + + + + align:start position:0% + +and will remind you that you have solved + + align:start position:0% +and will remind you that you have solved + + + align:start position:0% +and will remind you that you have solved +the problem of the infinite square well + + align:start position:0% +the problem of the infinite square well + + + align:start position:0% +the problem of the infinite square well +and you know what the energies the + + align:start position:0% +and you know what the energies the + + + align:start position:0% +and you know what the energies the +eigenenergies and eigenfunctions are of + + align:start position:0% +eigenenergies and eigenfunctions are of + + + align:start position:0% +eigenenergies and eigenfunctions are of +the energy operators energy operator in + + align:start position:0% +the energy operators energy operator in + + + align:start position:0% +the energy operators energy operator in +the infinite square well so remember + + align:start position:0% +the infinite square well so remember + + + align:start position:0% +the infinite square well so remember +back to what those are all right and you + + align:start position:0% +back to what those are all right and you + + + align:start position:0% +back to what those are all right and you +have five seconds okay we are at about + + align:start position:0% +have five seconds okay we are at about + + + align:start position:0% +have five seconds okay we are at about +50/50 correct + + align:start position:0% +50/50 correct + + + align:start position:0% +50/50 correct +so chat with the person next to you + + align:start position:0% + + + + align:start position:0% + +all right and now any moments go ahead + + align:start position:0% +all right and now any moments go ahead + + + align:start position:0% +all right and now any moments go ahead +and vote again good five more seconds + + align:start position:0% +and vote again good five more seconds + + + align:start position:0% +and vote again good five more seconds +and then put in your final vote okay + + align:start position:0% +and then put in your final vote okay + + + align:start position:0% +and then put in your final vote okay +that's it for now so what's the answer D + + align:start position:0% +that's it for now so what's the answer D + + + align:start position:0% +that's it for now so what's the answer D +is the answer but a lot of people so + + align:start position:0% +is the answer but a lot of people so + + + align:start position:0% +is the answer but a lot of people so +it's in doubt so who wants to give an + + align:start position:0% +it's in doubt so who wants to give an + + + align:start position:0% +it's in doubt so who wants to give an +explanation for why it's D excellent + + align:start position:0% +explanation for why it's D excellent + + + align:start position:0% +explanation for why it's D excellent +excellent really okay so I'm gonna + + align:start position:0% +excellent really okay so I'm gonna + + + align:start position:0% +excellent really okay so I'm gonna +restate that that was exactly correct in + + align:start position:0% +restate that that was exactly correct in + + + align:start position:0% +restate that that was exactly correct in +every step so the first thing is that + + align:start position:0% +every step so the first thing is that + + + align:start position:0% +every step so the first thing is that +wave function at time 0 sine squared of + + align:start position:0% +wave function at time 0 sine squared of + + + align:start position:0% +wave function at time 0 sine squared of +X is not an eigenfunction of the energy + + align:start position:0% +X is not an eigenfunction of the energy + + + align:start position:0% +X is not an eigenfunction of the energy +operator for the system in fact we + + align:start position:0% +operator for the system in fact we + + + align:start position:0% +operator for the system in fact we +computed the eigenfunctions for the + + align:start position:0% +computed the eigenfunctions for the + + + align:start position:0% +computed the eigenfunctions for the +energy operator in the infinite square + + align:start position:0% +energy operator in the infinite square + + + align:start position:0% +energy operator in the infinite square +well and their signs where they get a + + align:start position:0% +well and their signs where they get a + + + align:start position:0% +well and their signs where they get a +zero at the ends on the other hand any + + align:start position:0% +zero at the ends on the other hand any + + + align:start position:0% +zero at the ends on the other hand any +function with which satisfying the + + align:start position:0% +function with which satisfying the + + + align:start position:0% +function with which satisfying the +boundary conditions normalizable hits + + align:start position:0% +boundary conditions normalizable hits + + + align:start position:0% +boundary conditions normalizable hits +zero at the boundaries is a + + align:start position:0% +zero at the boundaries is a + + + align:start position:0% +zero at the boundaries is a +superposition of energy eigenfunctions + + align:start position:0% +superposition of energy eigenfunctions + + + align:start position:0% +superposition of energy eigenfunctions +and we can use that to determine the + + align:start position:0% +and we can use that to determine the + + + align:start position:0% +and we can use that to determine the +time evolution we take that + + align:start position:0% +time evolution we take that + + + align:start position:0% +time evolution we take that +superposition and and add on a phase e + + align:start position:0% +superposition and and add on a phase e + + + align:start position:0% +superposition and and add on a phase e +to the minus IET upon h-bar for each of + + align:start position:0% +to the minus IET upon h-bar for each of + + + align:start position:0% +to the minus IET upon h-bar for each of +the energy eigenfunctions and in Part D + + align:start position:0% +the energy eigenfunctions and in Part D + + + align:start position:0% +the energy eigenfunctions and in Part D +we express that wave function as a + + align:start position:0% +we express that wave function as a + + + align:start position:0% +we express that wave function as a +superposition with the coefficient cn + + align:start position:0% +superposition with the coefficient cn + + + align:start position:0% +superposition with the coefficient cn +determined from the overlap of our + + align:start position:0% +determined from the overlap of our + + + align:start position:0% +determined from the overlap of our +original function and the energy + + align:start position:0% +original function and the energy + + + align:start position:0% +original function and the energy +eigenfunctions everyone cool that so + + align:start position:0% +eigenfunctions everyone cool that so + + + align:start position:0% +eigenfunctions everyone cool that so +this is literally just a transcription + + align:start position:0% +this is literally just a transcription + + + align:start position:0% +this is literally just a transcription +of one of our postulates + + align:start position:0% +of one of our postulates + + + align:start position:0% +of one of our postulates +ok questions if you have any questions + + align:start position:0% +ok questions if you have any questions + + + align:start position:0% +ok questions if you have any questions +at all ask them this is the time to ask + + align:start position:0% +at all ask them this is the time to ask + + + align:start position:0% +at all ask them this is the time to ask +yeah + + align:start position:0% + + + + align:start position:0% + +exactly so the way you get CN is by + + align:start position:0% +exactly so the way you get CN is by + + + align:start position:0% +exactly so the way you get CN is by +saying look I have my wave function Phi + + align:start position:0% +saying look I have my wave function Phi + + + align:start position:0% +saying look I have my wave function Phi +of X is equal to sum over n CN Phi n of + + align:start position:0% +of X is equal to sum over n CN Phi n of + + + align:start position:0% +of X is equal to sum over n CN Phi n of +X where these fans are energy + + align:start position:0% +X where these fans are energy + + + align:start position:0% +X where these fans are energy +eigenfunctions e Phi n is equal to e n + + align:start position:0% +eigenfunctions e Phi n is equal to e n + + + align:start position:0% +eigenfunctions e Phi n is equal to e n +Phi n right of X and we also know that + + align:start position:0% +Phi n right of X and we also know that + + + align:start position:0% +Phi n right of X and we also know that +the integral of Phi n complex conjugate + + align:start position:0% +the integral of Phi n complex conjugate + + + align:start position:0% +the integral of Phi n complex conjugate +Phi M is equal to Delta MN right this is + + align:start position:0% +Phi M is equal to Delta MN right this is + + + align:start position:0% +Phi M is equal to Delta MN right this is +the statement that they're orthogonal + + align:start position:0% +the statement that they're orthogonal + + + align:start position:0% +the statement that they're orthogonal +and properly normalized we also write + + align:start position:0% +and properly normalized we also write + + + align:start position:0% +and properly normalized we also write +this as equal to Phi n Phi M and we can + + align:start position:0% +this as equal to Phi n Phi M and we can + + + align:start position:0% +this as equal to Phi n Phi M and we can +use this to determine the CNS the CN is + + align:start position:0% +use this to determine the CNS the CN is + + + align:start position:0% +use this to determine the CNS the CN is +equal to the inner product of Phi n with + + align:start position:0% +equal to the inner product of Phi n with + + + align:start position:0% +equal to the inner product of Phi n with +our wave function this is equal to the + + align:start position:0% +our wave function this is equal to the + + + align:start position:0% +our wave function this is equal to the +integral DX Phi star Phi n star sign + + align:start position:0% +integral DX Phi star Phi n star sign + + + align:start position:0% +integral DX Phi star Phi n star sign +which is equal to the integral DX Phi n + + align:start position:0% +which is equal to the integral DX Phi n + + + align:start position:0% +which is equal to the integral DX Phi n +star sum over m of C M by M but this sum + + align:start position:0% +star sum over m of C M by M but this sum + + + align:start position:0% +star sum over m of C M by M but this sum +over m of C M can be pulled out because + + align:start position:0% +over m of C M can be pulled out because + + + align:start position:0% +over m of C M can be pulled out because +this is just an integral over a sum of + + align:start position:0% +this is just an integral over a sum of + + + align:start position:0% +this is just an integral over a sum of +terms which is the same as a sum over m + + align:start position:0% +terms which is the same as a sum over m + + + align:start position:0% +terms which is the same as a sum over m +cm integral Phi n complex conjugate to + + align:start position:0% +cm integral Phi n complex conjugate to + + + align:start position:0% +cm integral Phi n complex conjugate to +Phi M and that's Delta MN which is 0 + + align:start position:0% +Phi M and that's Delta MN which is 0 + + + align:start position:0% +Phi M and that's Delta MN which is 0 +unless n is equal to M because these + + align:start position:0% +unless n is equal to M because these + + + align:start position:0% +unless n is equal to M because these +guys are orthogonal and properly + + align:start position:0% +guys are orthogonal and properly + + + align:start position:0% +guys are orthogonal and properly +normalized so this is zero unless n is + + align:start position:0% +normalized so this is zero unless n is + + + align:start position:0% +normalized so this is zero unless n is +equal to M so in this sum the only term + + align:start position:0% +equal to M so in this sum the only term + + + align:start position:0% +equal to M so in this sum the only term +that contributes is when M is equal to n + + align:start position:0% +that contributes is when M is equal to n + + + align:start position:0% +that contributes is when M is equal to n +this is equal to CN so CN is given by + + align:start position:0% +this is equal to CN so CN is given by + + + align:start position:0% +this is equal to CN so CN is given by +the overlap of our wave function with + + align:start position:0% +the overlap of our wave function with + + + align:start position:0% +the overlap of our wave function with +the corresponding eigen function this + + align:start position:0% +the corresponding eigen function this + + + align:start position:0% +the corresponding eigen function this +allows us to take our function a known + + align:start position:0% +allows us to take our function a known + + + align:start position:0% +allows us to take our function a known +function for example sine squared and + + align:start position:0% +function for example sine squared and + + + align:start position:0% +function for example sine squared and +express the coefficients in terms of an + + align:start position:0% +express the coefficients in terms of an + + + align:start position:0% +express the coefficients in terms of an +overlap of our wave function sine + + align:start position:0% +overlap of our wave function sine + + + align:start position:0% +overlap of our wave function sine +squared with the wave functions sign and + + align:start position:0% +squared with the wave functions sign and + + + align:start position:0% +squared with the wave functions sign and +that's exactly the expression you see + + align:start position:0% +that's exactly the expression you see + + + align:start position:0% +that's exactly the expression you see +below CN is equal to the integral of + + align:start position:0% +below CN is equal to the integral of + + + align:start position:0% +below CN is equal to the integral of +sine squared our wave function and sine + + align:start position:0% +sine squared our wave function and sine + + + align:start position:0% +sine squared our wave function and sine +which is the energy eigenfunction cool + + align:start position:0% +which is the energy eigenfunction cool + + + align:start position:0% +which is the energy eigenfunction cool +other + + align:start position:0% +other + + + align:start position:0% +other +questions okay great + + align:start position:0% + + + + align:start position:0% + +next problem come to me a computer + + align:start position:0% + + + + align:start position:0% + +I can't it should be written in Python + + align:start position:0% +I can't it should be written in Python + + + align:start position:0% +I can't it should be written in Python +okay I'm good yeah eigenstates Phi n + + align:start position:0% +okay I'm good yeah eigenstates Phi n + + + align:start position:0% +okay I'm good yeah eigenstates Phi n +which we usually call sign but there it + + align:start position:0% +which we usually call sign but there it + + + align:start position:0% +which we usually call sign but there it +is form an orthonormal set meaning + + align:start position:0% +is form an orthonormal set meaning + + + align:start position:0% +is form an orthonormal set meaning +integral of Phi M star Phi n is Delta MN + + align:start position:0% +integral of Phi M star Phi n is Delta MN + + + align:start position:0% +integral of Phi M star Phi n is Delta MN +what is the value of integral Siam + + align:start position:0% +what is the value of integral Siam + + + align:start position:0% +what is the value of integral Siam +against the sum CN Phi n okay you got + + align:start position:0% +against the sum CN Phi n okay you got + + + align:start position:0% +against the sum CN Phi n okay you got +five seconds give you a little extra + + align:start position:0% +five seconds give you a little extra + + + align:start position:0% +five seconds give you a little extra +time because people are clicking away + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +you now have seven seconds because time + + align:start position:0% +you now have seven seconds because time + + + align:start position:0% +you now have seven seconds because time +is nonlinear okay so quickly discuss + + align:start position:0% +is nonlinear okay so quickly discuss + + + align:start position:0% +is nonlinear okay so quickly discuss +because there's still some ambiguity + + align:start position:0% +because there's still some ambiguity + + + align:start position:0% +because there's still some ambiguity +here + + align:start position:0% + + + + align:start position:0% + +all right you have 10 seconds to modify + + align:start position:0% +all right you have 10 seconds to modify + + + align:start position:0% +all right you have 10 seconds to modify +your clicks click alright yes and the + + align:start position:0% +your clicks click alright yes and the + + + align:start position:0% +your clicks click alright yes and the +answer is C excellent okay good right + + align:start position:0% +answer is C excellent okay good right + + + align:start position:0% +answer is C excellent okay good right +because in fact we just did that okay + + align:start position:0% +because in fact we just did that okay + + + align:start position:0% +because in fact we just did that okay +that one happened on the actual exam so + + align:start position:0% +that one happened on the actual exam so + + + align:start position:0% +that one happened on the actual exam so +here's the next question + + align:start position:0% +here's the next question + + + align:start position:0% +here's the next question +let the Hamiltonian on a dagger u n + + align:start position:0% +let the Hamiltonian on a dagger u n + + + align:start position:0% +let the Hamiltonian on a dagger u n +equals y n plus H Omega that should be + + align:start position:0% +equals y n plus H Omega that should be + + + align:start position:0% +equals y n plus H Omega that should be +an H bar a dagger u n what can you say + + align:start position:0% +an H bar a dagger u n what can you say + + + align:start position:0% +an H bar a dagger u n what can you say +about a dagger u n here what we should + + align:start position:0% +about a dagger u n here what we should + + + align:start position:0% +about a dagger u n here what we should +probably say what can one say you know + + align:start position:0% +probably say what can one say you know + + + align:start position:0% +probably say what can one say you know +possible okay what could one say + + align:start position:0% + + + + align:start position:0% + +here the assumption just to say it out + + align:start position:0% +here the assumption just to say it out + + + align:start position:0% +here the assumption just to say it out +loud the assumption is that UN is an + + align:start position:0% +loud the assumption is that UN is an + + + align:start position:0% +loud the assumption is that UN is an +eigenfunction of the energy operator H + + align:start position:0% +eigenfunction of the energy operator H + + + align:start position:0% +eigenfunction of the energy operator H +with eigenvalue en okay you've got five + + align:start position:0% +with eigenvalue en okay you've got five + + + align:start position:0% +with eigenvalue en okay you've got five +seconds all right we are at 5050 so + + align:start position:0% +seconds all right we are at 5050 so + + + align:start position:0% +seconds all right we are at 5050 so +discuss amongst yourselves + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +all right you have okay go ahead and + + align:start position:0% +all right you have okay go ahead and + + + align:start position:0% +all right you have okay go ahead and +enter again enter your modified guesses + + align:start position:0% +enter again enter your modified guesses + + + align:start position:0% +enter again enter your modified guesses +and you have ten seconds to do so wow + + align:start position:0% +and you have ten seconds to do so wow + + + align:start position:0% +and you have ten seconds to do so wow +this is a lot better okay this is great + + align:start position:0% +this is a lot better okay this is great + + + align:start position:0% +this is a lot better okay this is great +so this is one of those really + + align:start position:0% +so this is one of those really + + + align:start position:0% +so this is one of those really +satisfying moments it's improved but + + align:start position:0% +satisfying moments it's improved but + + + align:start position:0% +satisfying moments it's improved but +there's still some real doubt here so I + + align:start position:0% +there's still some real doubt here so I + + + align:start position:0% +there's still some real doubt here so I +would like to get one person to argue + + align:start position:0% +would like to get one person to argue + + + align:start position:0% +would like to get one person to argue +for B and one person to argue for C's + + align:start position:0% +for B and one person to argue for C's + + + align:start position:0% +for B and one person to argue for C's +who who wants to volunteer for each of + + align:start position:0% +who who wants to volunteer for each of + + + align:start position:0% +who who wants to volunteer for each of +those which one you want who's gonna + + align:start position:0% +those which one you want who's gonna + + + align:start position:0% +those which one you want who's gonna +argue for be someone's gonna argue for + + align:start position:0% +argue for be someone's gonna argue for + + + align:start position:0% +argue for be someone's gonna argue for +me come on I'm not gonna argue for you + + align:start position:0% +me come on I'm not gonna argue for you + + + align:start position:0% +me come on I'm not gonna argue for you +I'm not gonna argue for C either that + + align:start position:0% +I'm not gonna argue for C either that + + + align:start position:0% +I'm not gonna argue for C either that +defeat surprised me I have to see this + + align:start position:0% +defeat surprised me I have to see this + + + align:start position:0% +defeat surprised me I have to see this +all the time so who's gonna intervene + + align:start position:0% +all the time so who's gonna intervene + + + align:start position:0% +all the time so who's gonna intervene +okay you argue for me who's gonna argue + + align:start position:0% +okay you argue for me who's gonna argue + + + align:start position:0% +okay you argue for me who's gonna argue +for C all right yeah that worked out + + align:start position:0% +for C all right yeah that worked out + + + align:start position:0% +for C all right yeah that worked out +well + + align:start position:0% +well + + + align:start position:0% +well +great beat are you for me you can do it + + align:start position:0% + + + + align:start position:0% + +so I guess I can do this so originally I + + align:start position:0% +so I guess I can do this so originally I + + + align:start position:0% +so I guess I can do this so originally I +just kind of didn't read the question + + align:start position:0% +just kind of didn't read the question + + + align:start position:0% +just kind of didn't read the question +and I thought since you're acting the + + align:start position:0% +and I thought since you're acting the + + + align:start position:0% +and I thought since you're acting the +ladder operator on the I can say that + + align:start position:0% +ladder operator on the I can say that + + + align:start position:0% +ladder operator on the I can say that +you get a proportionality constant sign + + align:start position:0% +you get a proportionality constant sign + + + align:start position:0% +you get a proportionality constant sign +some eigenstate so that's why that's not + + align:start position:0% +some eigenstate so that's why that's not + + + align:start position:0% +some eigenstate so that's why that's not +the best argument imaginable for B but + + align:start position:0% +the best argument imaginable for B but + + + align:start position:0% +the best argument imaginable for B but +we'll take it we'll take it so you can + + align:start position:0% +we'll take it we'll take it so you can + + + align:start position:0% +we'll take it we'll take it so you can +thank you so I yeah when I put someone + + align:start position:0% +thank you so I yeah when I put someone + + + align:start position:0% +thank you so I yeah when I put someone +in an impossible position to see + + align:start position:0% + + + + align:start position:0% + +and that + + align:start position:0% + + + + align:start position:0% + +fantastic that's exactly right so let me + + align:start position:0% +fantastic that's exactly right so let me + + + align:start position:0% +fantastic that's exactly right so let me +walk through that let me say that out + + align:start position:0% +walk through that let me say that out + + + align:start position:0% +walk through that let me say that out +loud + + align:start position:0% +loud + + + align:start position:0% +loud +so from the first line it is clear that + + align:start position:0% +so from the first line it is clear that + + + align:start position:0% +so from the first line it is clear that +the object a UN is an eigenfunction of + + align:start position:0% +the object a UN is an eigenfunction of + + + align:start position:0% +the object a UN is an eigenfunction of +the energy operator right and it's got + + align:start position:0% +the energy operator right and it's got + + + align:start position:0% +the energy operator right and it's got +egg in value en plus h Omega so it is a + + align:start position:0% +egg in value en plus h Omega so it is a + + + align:start position:0% +egg in value en plus h Omega so it is a +stationary States an eigenfunction of + + align:start position:0% +stationary States an eigenfunction of + + + align:start position:0% +stationary States an eigenfunction of +the energy it is not the same one + + align:start position:0% +the energy it is not the same one + + + align:start position:0% +the energy it is not the same one +because it has a different eigen value + + align:start position:0% +because it has a different eigen value + + + align:start position:0% +because it has a different eigen value +so if what it means to be the same + + align:start position:0% +so if what it means to be the same + + + align:start position:0% +so if what it means to be the same +energy eigenstate as it has the same + + align:start position:0% +energy eigenstate as it has the same + + + align:start position:0% +energy eigenstate as it has the same +eigen value it has a different energy + + align:start position:0% +eigen value it has a different energy + + + align:start position:0% +eigen value it has a different energy +eigenvalue it is a different state and + + align:start position:0% +eigenvalue it is a different state and + + + align:start position:0% +eigenvalue it is a different state and +they're orthogonal we proved this before + + align:start position:0% +they're orthogonal we proved this before + + + align:start position:0% +they're orthogonal we proved this before +two states with different energy + + align:start position:0% +two states with different energy + + + align:start position:0% +two states with different energy +orthogonal so they don't even not only + + align:start position:0% +orthogonal so they don't even not only + + + align:start position:0% +orthogonal so they don't even not only +are they not the same they don't even + + align:start position:0% +are they not the same they don't even + + + align:start position:0% +are they not the same they don't even +have any overlap okay so it is a + + align:start position:0% +have any overlap okay so it is a + + + align:start position:0% +have any overlap okay so it is a +stationary state but it's not + + align:start position:0% +stationary state but it's not + + + align:start position:0% +stationary state but it's not +proportional with the state UN it's an + + align:start position:0% +proportional with the state UN it's an + + + align:start position:0% +proportional with the state UN it's an +important one okay + + align:start position:0% +important one okay + + + align:start position:0% +important one okay +questions about that one before we move + + align:start position:0% +questions about that one before we move + + + align:start position:0% +questions about that one before we move +on to the next if it were proportional + + align:start position:0% +on to the next if it were proportional + + + align:start position:0% +on to the next if it were proportional +to the state UN then it would be some + + align:start position:0% +to the state UN then it would be some + + + align:start position:0% +to the state UN then it would be some +constant times UN that's what we mean by + + align:start position:0% +constant times UN that's what we mean by + + + align:start position:0% +constant times UN that's what we mean by +saying it's proportional but then if we + + align:start position:0% +saying it's proportional but then if we + + + align:start position:0% +saying it's proportional but then if we +acted on it with the energy operator + + align:start position:0% +acted on it with the energy operator + + + align:start position:0% +acted on it with the energy operator +what would the eigenvalue be so let me + + align:start position:0% +what would the eigenvalue be so let me + + + align:start position:0% +what would the eigenvalue be so let me +say this again suppose I have a state UN + + align:start position:0% +say this again suppose I have a state UN + + + align:start position:0% +say this again suppose I have a state UN +which I know that if I act with the + + align:start position:0% +which I know that if I act with the + + + align:start position:0% +which I know that if I act with the +energy operator on it or this is + + align:start position:0% +energy operator on it or this is + + + align:start position:0% +energy operator on it or this is +sometimes called H UN is equal to en un + + align:start position:0% +sometimes called H UN is equal to en un + + + align:start position:0% +sometimes called H UN is equal to en un +okay if I act with e on alpha UN where + + align:start position:0% +okay if I act with e on alpha UN where + + + align:start position:0% +okay if I act with e on alpha UN where +alpha is a constant what is this equal + + align:start position:0% +alpha is a constant what is this equal + + + align:start position:0% +alpha is a constant what is this equal +to alpha en un right so the eigenvalue + + align:start position:0% +to alpha en un right so the eigenvalue + + + align:start position:0% +to alpha en un right so the eigenvalue +is the same it's en right because they + + align:start position:0% +is the same it's en right because they + + + align:start position:0% +is the same it's en right because they +can't divide through by L so so if you + + align:start position:0% +can't divide through by L so so if you + + + align:start position:0% +can't divide through by L so so if you +have the same state meaning proportional + + align:start position:0% +have the same state meaning proportional + + + align:start position:0% +have the same state meaning proportional +to it then will have the same eigen + + align:start position:0% +to it then will have the same eigen + + + align:start position:0% +to it then will have the same eigen +value but this manifestly has a + + align:start position:0% +value but this manifestly has a + + + align:start position:0% +value but this manifestly has a +different eigen value cool awesome + + align:start position:0% +different eigen value cool awesome + + + align:start position:0% +different eigen value cool awesome +okay other questions yeah + + align:start position:0% +okay other questions yeah + + + align:start position:0% +okay other questions yeah +ah good okay so H is another name so + + align:start position:0% +ah good okay so H is another name so + + + align:start position:0% +ah good okay so H is another name so +some books use H and some books use E + + align:start position:0% +some books use H and some books use E + + + align:start position:0% +some books use H and some books use E +and the reason goes back to classical + + align:start position:0% +and the reason goes back to classical + + + align:start position:0% +and the reason goes back to classical +mechanics there's a there's an object + + align:start position:0% +mechanics there's a there's an object + + + align:start position:0% +mechanics there's a there's an object +called the Hamiltonian which it's sort + + align:start position:0% +called the Hamiltonian which it's sort + + + align:start position:0% +called the Hamiltonian which it's sort +of like saying I don't know it's like + + align:start position:0% +of like saying I don't know it's like + + + align:start position:0% +of like saying I don't know it's like +saying look bread and bond are the same + + align:start position:0% +saying look bread and bond are the same + + + align:start position:0% +saying look bread and bond are the same +thing but they evoke different things + + align:start position:0% +thing but they evoke different things + + + align:start position:0% +thing but they evoke different things +right you say bread and you think like + + align:start position:0% +right you say bread and you think like + + + align:start position:0% +right you say bread and you think like +Dixie and you say Ben and you think you + + align:start position:0% +Dixie and you say Ben and you think you + + + align:start position:0% +Dixie and you say Ben and you think you +know the me of some gorgeous baguette + + align:start position:0% +know the me of some gorgeous baguette + + + align:start position:0% +know the me of some gorgeous baguette +right okay it has a different feel it + + align:start position:0% +right okay it has a different feel it + + + align:start position:0% +right okay it has a different feel it +has a different feel so this invokes + + align:start position:0% +has a different feel so this invokes + + + align:start position:0% +has a different feel so this invokes +different things a particular to a + + align:start position:0% +different things a particular to a + + + align:start position:0% +different things a particular to a +classical mechanic the Hamiltonian is + + align:start position:0% +classical mechanic the Hamiltonian is + + + align:start position:0% +classical mechanic the Hamiltonian is +the generator of time translations now + + align:start position:0% +the generator of time translations now + + + align:start position:0% +the generator of time translations now +we don't usually that wasn't the classic + + align:start position:0% +we don't usually that wasn't the classic + + + align:start position:0% +we don't usually that wasn't the classic +way of thinking about the energy + + align:start position:0% +way of thinking about the energy + + + align:start position:0% +way of thinking about the energy +operator in you know say Newton's time + + align:start position:0% +operator in you know say Newton's time + + + align:start position:0% +operator in you know say Newton's time +okay but it is how we think about energy + + align:start position:0% +okay but it is how we think about energy + + + align:start position:0% +okay but it is how we think about energy +now so that's just this is just + + align:start position:0% +now so that's just this is just + + + align:start position:0% +now so that's just this is just +terminology for anyone who didn't get + + align:start position:0% +terminology for anyone who didn't get + + + align:start position:0% +terminology for anyone who didn't get +that sorry about that this is something + + align:start position:0% +that sorry about that this is something + + + align:start position:0% +that sorry about that this is something +that we've run across before but I + + align:start position:0% +that we've run across before but I + + + align:start position:0% +that we've run across before but I +should emphasize so when you hear people + + align:start position:0% +should emphasize so when you hear people + + + align:start position:0% +should emphasize so when you hear people +say the Hamiltonian that means the + + align:start position:0% +say the Hamiltonian that means the + + + align:start position:0% +say the Hamiltonian that means the +energy operator the reason I say energy + + align:start position:0% +energy operator the reason I say energy + + + align:start position:0% +energy operator the reason I say energy +operator rather than saying Hamiltonian + + align:start position:0% +operator rather than saying Hamiltonian + + + align:start position:0% +operator rather than saying Hamiltonian +which is the more common thing in the + + align:start position:0% +which is the more common thing in the + + + align:start position:0% +which is the more common thing in the +lingua franca of quantum mechanics + + align:start position:0% +lingua franca of quantum mechanics + + + align:start position:0% +lingua franca of quantum mechanics +because I want to impress upon you guys + + align:start position:0% +because I want to impress upon you guys + + + align:start position:0% +because I want to impress upon you guys +that it's just energy it is the energy + + align:start position:0% +that it's just energy it is the energy + + + align:start position:0% +that it's just energy it is the energy +it's nothing else it's not some strange + + align:start position:0% +it's nothing else it's not some strange + + + align:start position:0% +it's nothing else it's not some strange +beast it's just energy okay other + + align:start position:0% +beast it's just energy okay other + + + align:start position:0% +beast it's just energy okay other +questions bread + + align:start position:0% + + + + align:start position:0% + +other questions okay for next question + + align:start position:0% +other questions okay for next question + + + align:start position:0% +other questions okay for next question +which of these graphs shows the + + align:start position:0% +which of these graphs shows the + + + align:start position:0% +which of these graphs shows the +curvature of the wave function in a + + align:start position:0% +curvature of the wave function in a + + + align:start position:0% +curvature of the wave function in a +classically allowed region okay five + + align:start position:0% +classically allowed region okay five + + + align:start position:0% +classically allowed region okay five +seconds left all right + + align:start position:0% +seconds left all right + + + align:start position:0% +seconds left all right +fantastic and the answer is a because + + align:start position:0% +fantastic and the answer is a because + + + align:start position:0% +fantastic and the answer is a because +the curvature has to be towards the axis + + align:start position:0% +the curvature has to be towards the axis + + + align:start position:0% +the curvature has to be towards the axis +in a classically allowed reason the wave + + align:start position:0% +in a classically allowed reason the wave + + + align:start position:0% +in a classically allowed reason the wave +function is sinusoidal + + align:start position:0% +function is sinusoidal + + + align:start position:0% +function is sinusoidal +it's oscillatory alright and oops and + + align:start position:0% +it's oscillatory alright and oops and + + + align:start position:0% +it's oscillatory alright and oops and +the partner of that question is what + + align:start position:0% +the partner of that question is what + + + align:start position:0% +the partner of that question is what +about in the classically disallowed + + align:start position:0% +about in the classically disallowed + + + align:start position:0% +about in the classically disallowed +region okay five seconds okay awesome + + align:start position:0% +region okay five seconds okay awesome + + + align:start position:0% +region okay five seconds okay awesome +and basically everyone got this be great + + align:start position:0% +and basically everyone got this be great + + + align:start position:0% +and basically everyone got this be great +questions all right oh yeah sorry + + align:start position:0% +questions all right oh yeah sorry + + + align:start position:0% +questions all right oh yeah sorry +nope no that's a very good question so C + + align:start position:0% +nope no that's a very good question so C + + + align:start position:0% +nope no that's a very good question so C +and D I should say I should let me be a + + align:start position:0% +and D I should say I should let me be a + + + align:start position:0% +and D I should say I should let me be a +little more precise but it's a very + + align:start position:0% +little more precise but it's a very + + + align:start position:0% +little more precise but it's a very +reasonable question so let me give you + + align:start position:0% +reasonable question so let me give you + + + align:start position:0% +reasonable question so let me give you +an answer suppose you saw a wave + + align:start position:0% +an answer suppose you saw a wave + + + align:start position:0% +an answer suppose you saw a wave +function that had the curvature + + align:start position:0% +function that had the curvature + + + align:start position:0% +function that had the curvature +structure of C it was curved oscillatory + + align:start position:0% +structure of C it was curved oscillatory + + + align:start position:0% +structure of C it was curved oscillatory +over there and curved exponential over + + align:start position:0% +over there and curved exponential over + + + align:start position:0% +over there and curved exponential over +there on the right what would you say + + align:start position:0% +there on the right what would you say + + + align:start position:0% +there on the right what would you say +about the potential relative to the + + align:start position:0% +about the potential relative to the + + + align:start position:0% +about the potential relative to the +energy sagan yeah good so on one side + + align:start position:0% +energy sagan yeah good so on one side + + + align:start position:0% +energy sagan yeah good so on one side +were allowed and on the other side were + + align:start position:0% +were allowed and on the other side were + + + align:start position:0% +were allowed and on the other side were +disallowed so if you saw a wave function + + align:start position:0% +disallowed so if you saw a wave function + + + align:start position:0% +disallowed so if you saw a wave function +that had that curvature structure you'd + + align:start position:0% +that had that curvature structure you'd + + + align:start position:0% +that had that curvature structure you'd +immediately know that it was in the loud + + align:start position:0% +immediately know that it was in the loud + + + align:start position:0% +immediately know that it was in the loud +region on the left but then on the right + + align:start position:0% +region on the left but then on the right + + + align:start position:0% +region on the left but then on the right +it was disallowed classically just + + align:start position:0% +it was disallowed classically just + + + align:start position:0% +it was disallowed classically just +because it had curvature away from the + + align:start position:0% +because it had curvature away from the + + + align:start position:0% +because it had curvature away from the +axis that cool so that's something you + + align:start position:0% +axis that cool so that's something you + + + align:start position:0% +axis that cool so that's something you +if you saw a wave function so for + + align:start position:0% +if you saw a wave function so for + + + align:start position:0% +if you saw a wave function so for +example you might say well look you + + align:start position:0% +example you might say well look you + + + align:start position:0% +example you might say well look you +never get a wave function that does this + + align:start position:0% +never get a wave function that does this + + + align:start position:0% +never get a wave function that does this +and and that's not true right you could + + align:start position:0% +and and that's not true right you could + + + align:start position:0% +and and that's not true right you could +do that so this would be classically + + align:start position:0% +do that so this would be classically + + + align:start position:0% +do that so this would be classically +disallowed because it's curvature down + + align:start position:0% +disallowed because it's curvature down + + + align:start position:0% +disallowed because it's curvature down +this would be + + align:start position:0% +this would be + + + align:start position:0% +this would be +classically loud so the potential for + + align:start position:0% +classically loud so the potential for + + + align:start position:0% +classically loud so the potential for +example if this is the energy the + + align:start position:0% +example if this is the energy the + + + align:start position:0% +example if this is the energy the +potential could be do do okay so a + + align:start position:0% +potential could be do do okay so a + + + align:start position:0% +potential could be do do okay so a +potential like this could lead to a wave + + align:start position:0% +potential like this could lead to a wave + + + align:start position:0% +potential like this could lead to a wave +function like this that cool okay so + + align:start position:0% +function like this that cool okay so + + + align:start position:0% +function like this that cool okay so +it's a very good question I'm sorry I + + align:start position:0% +it's a very good question I'm sorry I + + + align:start position:0% +it's a very good question I'm sorry I +should have seen what you were asking + + align:start position:0% +should have seen what you were asking + + + align:start position:0% +should have seen what you were asking +more immediately okay other questions is + + align:start position:0% +more immediately okay other questions is + + + align:start position:0% +more immediately okay other questions is +following up on that anything okay cool + + align:start position:0% + + + + align:start position:0% + +no one ever asked that question before + + align:start position:0% +no one ever asked that question before + + + align:start position:0% +no one ever asked that question before +and I just want to emphasize that you + + align:start position:0% +and I just want to emphasize that you + + + align:start position:0% +and I just want to emphasize that you +guys should just ask questions when you + + align:start position:0% +guys should just ask questions when you + + + align:start position:0% +guys should just ask questions when you +don't when you're confused by something + + align:start position:0% +don't when you're confused by something + + + align:start position:0% +don't when you're confused by something +someone else is gonna be confused by it + + align:start position:0% +someone else is gonna be confused by it + + + align:start position:0% +someone else is gonna be confused by it +I wouldn't even necessarily know that + + align:start position:0% +I wouldn't even necessarily know that + + + align:start position:0% +I wouldn't even necessarily know that +the question is a meaningful question I + + align:start position:0% +the question is a meaningful question I + + + align:start position:0% +the question is a meaningful question I +get questions I've never heard before + + align:start position:0% +get questions I've never heard before + + + align:start position:0% +get questions I've never heard before +all the time in this class just don't + + align:start position:0% +all the time in this class just don't + + + align:start position:0% +all the time in this class just don't +hesitate to ask it's always a good idea + + align:start position:0% +hesitate to ask it's always a good idea + + + align:start position:0% +hesitate to ask it's always a good idea +okay next one wave function Phi has been + + align:start position:0% +okay next one wave function Phi has been + + + align:start position:0% +okay next one wave function Phi has been +expressed as a sum over energy + + align:start position:0% +expressed as a sum over energy + + + align:start position:0% +expressed as a sum over energy +eigenfunctions UN compared to the + + align:start position:0% +eigenfunctions UN compared to the + + + align:start position:0% +eigenfunctions UN compared to the +original wave function as a function of + + align:start position:0% +original wave function as a function of + + + align:start position:0% +original wave function as a function of +X a set of coefficients C 1 dot dot + + align:start position:0% +X a set of coefficients C 1 dot dot + + + align:start position:0% +X a set of coefficients C 1 dot dot +contains more or less same information + + align:start position:0% +contains more or less same information + + + align:start position:0% +contains more or less same information +or cannot be determined or depends + + align:start position:0% +or cannot be determined or depends + + + align:start position:0% +or cannot be determined or depends +all right 5 seconds + + align:start position:0% + + + + align:start position:0% + +all right and the answer is same + + align:start position:0% +all right and the answer is same + + + align:start position:0% +all right and the answer is same +information + + align:start position:0% +information + + + align:start position:0% +information +good questions okay good some of these + + align:start position:0% +good questions okay good some of these + + + align:start position:0% +good questions okay good some of these +you've seen before F and G are wave + + align:start position:0% +you've seen before F and G are wave + + + align:start position:0% +you've seen before F and G are wave +functions and C is a constant then the + + align:start position:0% +functions and C is a constant then the + + + align:start position:0% +functions and C is a constant then the +inner product C F with G is equal to + + align:start position:0% +inner product C F with G is equal to + + + align:start position:0% +inner product C F with G is equal to +click away ten seconds + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +okay you've got about five seconds still + + align:start position:0% +okay you've got about five seconds still + + + align:start position:0% +okay you've got about five seconds still +a lot of fluctuations here wow I'm + + align:start position:0% +a lot of fluctuations here wow I'm + + + align:start position:0% +a lot of fluctuations here wow I'm +surprised by this one all right + + align:start position:0% +surprised by this one all right + + + align:start position:0% +surprised by this one all right +uh yeah question let's come back the + + align:start position:0% +uh yeah question let's come back the + + + align:start position:0% +uh yeah question let's come back the +previous one I have to redo this sir + + align:start position:0% +previous one I have to redo this sir + + + align:start position:0% +previous one I have to redo this sir +thanks but remind me to after we move on + + align:start position:0% +thanks but remind me to after we move on + + + align:start position:0% +thanks but remind me to after we move on +okay so discuss because about a third of + + align:start position:0% +okay so discuss because about a third of + + + align:start position:0% +okay so discuss because about a third of +you got this one wrong + + align:start position:0% +you got this one wrong + + + align:start position:0% +you got this one wrong +so discuss + + align:start position:0% + + + + align:start position:0% + +all right so go ahead and put in your + + align:start position:0% +all right so go ahead and put in your + + + align:start position:0% +all right so go ahead and put in your +answers again good all right another + + align:start position:0% +answers again good all right another + + + align:start position:0% +answers again good all right another +five seconds great okay and the answer + + align:start position:0% +five seconds great okay and the answer + + + align:start position:0% +five seconds great okay and the answer +is good get that complex conjugation + + align:start position:0% +is good get that complex conjugation + + + align:start position:0% +is good get that complex conjugation +right little things like that can cause + + align:start position:0% +right little things like that can cause + + + align:start position:0% +right little things like that can cause +you an infinite amount of trouble + + align:start position:0% +you an infinite amount of trouble + + + align:start position:0% +you an infinite amount of trouble +especially as you'll notice on the + + align:start position:0% +especially as you'll notice on the + + + align:start position:0% +especially as you'll notice on the +problem set when you're computing time + + align:start position:0% +problem set when you're computing time + + + align:start position:0% +problem set when you're computing time +dependence of expectation values getting + + align:start position:0% +dependence of expectation values getting + + + align:start position:0% +dependence of expectation values getting +that complex conjugation right is + + align:start position:0% +that complex conjugation right is + + + align:start position:0% +that complex conjugation right is +essential because you need to see + + align:start position:0% +essential because you need to see + + + align:start position:0% +essential because you need to see +interference terms and without the + + align:start position:0% +interference terms and without the + + + align:start position:0% +interference terms and without the +complex conjugation you will not get the + + align:start position:0% +complex conjugation you will not get the + + + align:start position:0% +complex conjugation you will not get the +right interference terms okay question + + align:start position:0% +right interference terms okay question + + + align:start position:0% +right interference terms okay question +oh yeah it's question from previous + + align:start position:0% +oh yeah it's question from previous + + + align:start position:0% +oh yeah it's question from previous +problem thank you the norm squared gives + + align:start position:0% +problem thank you the norm squared gives + + + align:start position:0% +problem thank you the norm squared gives +you the probabilities but if you know + + align:start position:0% +you the probabilities but if you know + + + align:start position:0% +you the probabilities but if you know +the coefficient so good this is a good + + align:start position:0% +the coefficient so good this is a good + + + align:start position:0% +the coefficient so good this is a good +question so let me rephrase the question + + align:start position:0% +question so let me rephrase the question + + + align:start position:0% +question so let me rephrase the question +so the question is look in the previous + + align:start position:0% +so the question is look in the previous + + + align:start position:0% +so the question is look in the previous +question we said look our wave function + + align:start position:0% +question we said look our wave function + + + align:start position:0% +question we said look our wave function +Phi of X is some function which we could + + align:start position:0% +Phi of X is some function which we could + + + align:start position:0% +Phi of X is some function which we could +draw right so I could represent this in + + align:start position:0% +draw right so I could represent this in + + + align:start position:0% +draw right so I could represent this in +two ways I could have there draw it or I + + align:start position:0% +two ways I could have there draw it or I + + + align:start position:0% +two ways I could have there draw it or I +could represent it as equal the sum over + + align:start position:0% +could represent it as equal the sum over + + + align:start position:0% +could represent it as equal the sum over +n of C n Phi n where Phi n are the known + + align:start position:0% +n of C n Phi n where Phi n are the known + + + align:start position:0% +n of C n Phi n where Phi n are the known +energy eigenfunctions right and the + + align:start position:0% +energy eigenfunctions right and the + + + align:start position:0% +energy eigenfunctions right and the +question is did the CN contain the same + + align:start position:0% +question is did the CN contain the same + + + align:start position:0% +question is did the CN contain the same +information so that's that was a + + align:start position:0% +information so that's that was a + + + align:start position:0% +information so that's that was a +question and the point that's being + + align:start position:0% +question and the point that's being + + + align:start position:0% +question and the point that's being +asked about here is a very good question + + align:start position:0% +asked about here is a very good question + + + align:start position:0% +asked about here is a very good question +the question is look we know what the C + + align:start position:0% +the question is look we know what the C + + + align:start position:0% +the question is look we know what the C +NS mean what the C ends mean is the + + align:start position:0% +NS mean what the C ends mean is the + + + align:start position:0% +NS mean what the C ends mean is the +probability that you measure the energy + + align:start position:0% +probability that you measure the energy + + + align:start position:0% +probability that you measure the energy +given that the state is signed the + + align:start position:0% +given that the state is signed the + + + align:start position:0% +given that the state is signed the +probability usually measure the energy B + + align:start position:0% +probability usually measure the energy B + + + align:start position:0% +probability usually measure the energy B +n is equal to norm CN squared right and + + align:start position:0% +n is equal to norm CN squared right and + + + align:start position:0% +n is equal to norm CN squared right and +so the CNS tell you about probabilities + + align:start position:0% +so the CNS tell you about probabilities + + + align:start position:0% +so the CNS tell you about probabilities +they don't tell you what the state is + + align:start position:0% +they don't tell you what the state is + + + align:start position:0% +they don't tell you what the state is +they just tell you what probability is + + align:start position:0% +they just tell you what probability is + + + align:start position:0% +they just tell you what probability is +that you'll measure a particular energy + + align:start position:0% +that you'll measure a particular energy + + + align:start position:0% +that you'll measure a particular energy +is that right so how can it contain the + + align:start position:0% +is that right so how can it contain the + + + align:start position:0% +is that right so how can it contain the +same information and the there are two + + align:start position:0% +same information and the there are two + + + align:start position:0% +same information and the there are two +important things to say about this first + + align:start position:0% +important things to say about this first + + + align:start position:0% +important things to say about this first +off this is of course true and this does + + align:start position:0% +off this is of course true and this does + + + align:start position:0% +off this is of course true and this does +give you the probability and the + + align:start position:0% +give you the probability and the + + + align:start position:0% +give you the probability and the +probability comes from the norm squared + + align:start position:0% +probability comes from the norm squared + + + align:start position:0% +probability comes from the norm squared +so the co if the phase of CN doesn't + + align:start position:0% +so the co if the phase of CN doesn't + + + align:start position:0% +so the co if the phase of CN doesn't +particularly matter for that however the + + align:start position:0% +particularly matter for that however the + + + align:start position:0% +particularly matter for that however the +claim that I can expand this function at + + align:start position:0% +claim that I can expand this function at + + + align:start position:0% +claim that I can expand this function at +in in a + + align:start position:0% +in in a + + + align:start position:0% +in in a +basis of the energy eigenfunctions in a + + align:start position:0% +basis of the energy eigenfunctions in a + + + align:start position:0% +basis of the energy eigenfunctions in a +basis of other functions is this + + align:start position:0% +basis of other functions is this + + + align:start position:0% +basis of other functions is this +statement if I know these CNS then I + + align:start position:0% +statement if I know these CNS then I + + + align:start position:0% +statement if I know these CNS then I +take C 1 multiplied by Phi 1 C 2 + + align:start position:0% +take C 1 multiplied by Phi 1 C 2 + + + align:start position:0% +take C 1 multiplied by Phi 1 C 2 +multiplied by Phi Q add them all back up + + align:start position:0% +multiplied by Phi Q add them all back up + + + align:start position:0% +multiplied by Phi Q add them all back up +and they get nothing other than this + + align:start position:0% +and they get nothing other than this + + + align:start position:0% +and they get nothing other than this +original function okay so if I know the + + align:start position:0% +original function okay so if I know the + + + align:start position:0% +original function okay so if I know the +C ends I can just construct that + + align:start position:0% +C ends I can just construct that + + + align:start position:0% +C ends I can just construct that +original function explicitly so this + + align:start position:0% +original function explicitly so this + + + align:start position:0% +original function explicitly so this +can't contain any more or any less + + align:start position:0% +can't contain any more or any less + + + align:start position:0% +can't contain any more or any less +information than the list of C NS as + + align:start position:0% +information than the list of C NS as + + + align:start position:0% +information than the list of C NS as +long as I know what basis I'm talking + + align:start position:0% +long as I know what basis I'm talking + + + align:start position:0% +long as I know what basis I'm talking +about okay so here's the disturbing + + align:start position:0% +about okay so here's the disturbing + + + align:start position:0% +about okay so here's the disturbing +thing about that when we say the wave + + align:start position:0% +thing about that when we say the wave + + + align:start position:0% +thing about that when we say the wave +function is the state of the system it + + align:start position:0% +function is the state of the system it + + + align:start position:0% +function is the state of the system it +contains all knowledge you could + + align:start position:0% +contains all knowledge you could + + + align:start position:0% +contains all knowledge you could +possibly have access to and not just + + align:start position:0% +possibly have access to and not just + + + align:start position:0% +possibly have access to and not just +knowledge that you could have access to + + align:start position:0% +knowledge that you could have access to + + + align:start position:0% +knowledge that you could have access to +it contains all of the information of + + align:start position:0% +it contains all of the information of + + + align:start position:0% +it contains all of the information of +the state and then we look at this and + + align:start position:0% +the state and then we look at this and + + + align:start position:0% +the state and then we look at this and +say well look it doesn't give us + + align:start position:0% +say well look it doesn't give us + + + align:start position:0% +say well look it doesn't give us +something deterministic because of + + align:start position:0% +something deterministic because of + + + align:start position:0% +something deterministic because of +something probabilistic it tells us the + + align:start position:0% +something probabilistic it tells us the + + + align:start position:0% +something probabilistic it tells us the +probability distribution for measuring + + align:start position:0% +probability distribution for measuring + + + align:start position:0% +probability distribution for measuring +the various different energies what does + + align:start position:0% +the various different energies what does + + + align:start position:0% +the various different energies what does +that immediately tell you since they're + + align:start position:0% +that immediately tell you since they're + + + align:start position:0% +that immediately tell you since they're +equivalent information this guy tells + + align:start position:0% +equivalent information this guy tells + + + align:start position:0% +equivalent information this guy tells +you nothing more than the probabilities + + align:start position:0% +you nothing more than the probabilities + + + align:start position:0% +you nothing more than the probabilities +I'm imagining it doesn't tell you what + + align:start position:0% +I'm imagining it doesn't tell you what + + + align:start position:0% +I'm imagining it doesn't tell you what +energies you'll measure it tells you the + + align:start position:0% +energies you'll measure it tells you the + + + align:start position:0% +energies you'll measure it tells you the +probabilities with which you will + + align:start position:0% +probabilities with which you will + + + align:start position:0% +probabilities with which you will +measure energies so they're the same + + align:start position:0% +measure energies so they're the same + + + align:start position:0% +measure energies so they're the same +thing it's a very it's a very good + + align:start position:0% +thing it's a very it's a very good + + + align:start position:0% +thing it's a very it's a very good +question and I think the way to take the + + align:start position:0% +question and I think the way to take the + + + align:start position:0% +question and I think the way to take the +sort of discomfort that that I don't + + align:start position:0% +sort of discomfort that that I don't + + + align:start position:0% +sort of discomfort that that I don't +know about you that causes me is just to + + align:start position:0% +know about you that causes me is just to + + + align:start position:0% +know about you that causes me is just to +read that as saying look the wave + + align:start position:0% +read that as saying look the wave + + + align:start position:0% +read that as saying look the wave +function is giving you probabilistic + + align:start position:0% +function is giving you probabilistic + + + align:start position:0% +function is giving you probabilistic +information about measurements + + align:start position:0% + + + + align:start position:0% + +excellent excellent + + align:start position:0% +excellent excellent + + + align:start position:0% +excellent excellent +okay so let me turn this around let me + + align:start position:0% +okay so let me turn this around let me + + + align:start position:0% +okay so let me turn this around let me +phrase it slightly different tell me if + + align:start position:0% +phrase it slightly different tell me if + + + align:start position:0% +phrase it slightly different tell me if +this is getting at the same point if I + + align:start position:0% +this is getting at the same point if I + + + align:start position:0% +this is getting at the same point if I +gave you a list of numbers one fourteen + + align:start position:0% +gave you a list of numbers one fourteen + + + align:start position:0% +gave you a list of numbers one fourteen +twelve does that tell you what function + + align:start position:0% +twelve does that tell you what function + + + align:start position:0% +twelve does that tell you what function +I'm talking about no I have to tell you + + align:start position:0% +I'm talking about no I have to tell you + + + align:start position:0% +I'm talking about no I have to tell you +that there are the expansion + + align:start position:0% +that there are the expansion + + + align:start position:0% +that there are the expansion +coefficients in say sine waves of a + + align:start position:0% +coefficients in say sine waves of a + + + align:start position:0% +coefficients in say sine waves of a +particular wavelength or energy + + align:start position:0% +particular wavelength or energy + + + align:start position:0% +particular wavelength or energy +eigenfunctions in some particular energy + + align:start position:0% +eigenfunctions in some particular energy + + + align:start position:0% +eigenfunctions in some particular energy +operator if I just give you a list of + + align:start position:0% +operator if I just give you a list of + + + align:start position:0% +operator if I just give you a list of +numbers it doesn't tell you what + + align:start position:0% +numbers it doesn't tell you what + + + align:start position:0% +numbers it doesn't tell you what +function is I have to give you a list of + + align:start position:0% +function is I have to give you a list of + + + align:start position:0% +function is I have to give you a list of +numbers and I have to tell you what + + align:start position:0% +numbers and I have to tell you what + + + align:start position:0% +numbers and I have to tell you what +basis I'm talking about if you have the + + align:start position:0% +basis I'm talking about if you have the + + + align:start position:0% +basis I'm talking about if you have the +wave function you don't need to know + + align:start position:0% +wave function you don't need to know + + + align:start position:0% +wave function you don't need to know +what basis you're talking about the wave + + align:start position:0% +what basis you're talking about the wave + + + align:start position:0% +what basis you're talking about the wave +function is basis independent right it's + + align:start position:0% +function is basis independent right it's + + + align:start position:0% +function is basis independent right it's +just a function in a few minutes I'm + + align:start position:0% +just a function in a few minutes I'm + + + align:start position:0% +just a function in a few minutes I'm +gonna come back and subvert what I just + + align:start position:0% +gonna come back and subvert what I just + + + align:start position:0% +gonna come back and subvert what I just +said but so the wave function is just + + align:start position:0% +said but so the wave function is just + + + align:start position:0% +said but so the wave function is just +what the wave function is and if I give + + align:start position:0% +what the wave function is and if I give + + + align:start position:0% +what the wave function is and if I give +you a list of numbers they're only + + align:start position:0% +you a list of numbers they're only + + + align:start position:0% +you a list of numbers they're only +equivalent when you also know the wave + + align:start position:0% +equivalent when you also know the wave + + + align:start position:0% +equivalent when you also know the wave +function so in order for these two + + align:start position:0% +function so in order for these two + + + align:start position:0% +function so in order for these two +things to be equivalent it's important + + align:start position:0% +things to be equivalent it's important + + + align:start position:0% +things to be equivalent it's important +that you know what basis you're talking + + align:start position:0% +that you know what basis you're talking + + + align:start position:0% +that you know what basis you're talking +about in particular it's important that + + align:start position:0% +about in particular it's important that + + + align:start position:0% +about in particular it's important that +you know the energy eigenfunctions is + + align:start position:0% +you know the energy eigenfunctions is + + + align:start position:0% +you know the energy eigenfunctions is +that is that getting it what what's the + + align:start position:0% +that is that getting it what what's the + + + align:start position:0% +that is that getting it what what's the +distinction you're making + + align:start position:0% +distinction you're making + + + align:start position:0% +distinction you're making +okay think more about it and and and and + + align:start position:0% +okay think more about it and and and and + + + align:start position:0% +okay think more about it and and and and +when when the question becomes more + + align:start position:0% +when when the question becomes more + + + align:start position:0% +when when the question becomes more +sharp ask okay other questions yeah + + align:start position:0% + + + + align:start position:0% + +you know the end are we supposed to do + + align:start position:0% + + + + align:start position:0% + +yeah yeah usually I I've I try on + + align:start position:0% +yeah yeah usually I I've I try on + + + align:start position:0% +yeah yeah usually I I've I try on +problem sets and exams to make that + + align:start position:0% +problem sets and exams to make that + + + align:start position:0% +problem sets and exams to make that +distinction clear but that will + + align:start position:0% +distinction clear but that will + + + align:start position:0% +distinction clear but that will +generally be assumed other questions all + + align:start position:0% +generally be assumed other questions all + + + align:start position:0% +generally be assumed other questions all +right I'm gonna come back to this but + + align:start position:0% +right I'm gonna come back to this but + + + align:start position:0% +right I'm gonna come back to this but +well I'm gonna come back to this when we + + align:start position:0% +well I'm gonna come back to this when we + + + align:start position:0% +well I'm gonna come back to this when we +finish with the clicker questions okay + + align:start position:0% +finish with the clicker questions okay + + + align:start position:0% +finish with the clicker questions okay +the next question in the simple harmonic + + align:start position:0% +the next question in the simple harmonic + + + align:start position:0% +the next question in the simple harmonic +oscillator the eigenvalues as we've just + + align:start position:0% +oscillator the eigenvalues as we've just + + + align:start position:0% +oscillator the eigenvalues as we've just +derived twice are en is h-bar n Rho + + align:start position:0% +derived twice are en is h-bar n Rho + + + align:start position:0% +derived twice are en is h-bar n Rho +Omega times n plus 1/2 for an integer N + + align:start position:0% +Omega times n plus 1/2 for an integer N + + + align:start position:0% +Omega times n plus 1/2 for an integer N +and a measurement of energy will always + + align:start position:0% +and a measurement of energy will always + + + align:start position:0% +and a measurement of energy will always +observe one of these values that's from + + align:start position:0% +observe one of these values that's from + + + align:start position:0% +observe one of these values that's from +postulate four three three what can we + + align:start position:0% +postulate four three three what can we + + + align:start position:0% +postulate four three three what can we +say about the expectation value of the + + align:start position:0% +say about the expectation value of the + + + align:start position:0% +say about the expectation value of the +energy in some arbitrary state okay + + align:start position:0% +energy in some arbitrary state okay + + + align:start position:0% +energy in some arbitrary state okay +this one isn't tricky but it's not + + align:start position:0% +this one isn't tricky but it's not + + + align:start position:0% +this one isn't tricky but it's not +trivial so think carefully about it + + align:start position:0% + + + + align:start position:0% + +all right you have five seconds enter + + align:start position:0% +all right you have five seconds enter + + + align:start position:0% +all right you have five seconds enter +your your best guess all right and you + + align:start position:0% +your your best guess all right and you + + + align:start position:0% +your your best guess all right and you +are at complete chance I think we've + + align:start position:0% +are at complete chance I think we've + + + align:start position:0% +are at complete chance I think we've +just put you through a hardness box so + + align:start position:0% +just put you through a hardness box so + + + align:start position:0% +just put you through a hardness box so +so discuss + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +and okay go ahead and start put in your + + align:start position:0% +and okay go ahead and start put in your + + + align:start position:0% +and okay go ahead and start put in your +modified response all right another five + + align:start position:0% +modified response all right another five + + + align:start position:0% +modified response all right another five +seconds or so okay click okay you're + + align:start position:0% +seconds or so okay click okay you're + + + align:start position:0% +seconds or so okay click okay you're +still there's still a lot of + + align:start position:0% +still there's still a lot of + + + align:start position:0% +still there's still a lot of +disagreement here so let's see so who + + align:start position:0% +disagreement here so let's see so who + + + align:start position:0% +disagreement here so let's see so who +would like to argue for C would like to + + align:start position:0% +would like to argue for C would like to + + + align:start position:0% +would like to argue for C would like to +argue for D go ahead excellent excellent + + align:start position:0% +argue for D go ahead excellent excellent + + + align:start position:0% +argue for D go ahead excellent excellent +okay so let me let me restate that so + + align:start position:0% +okay so let me let me restate that so + + + align:start position:0% +okay so let me let me restate that so +the statement if I'm following your + + align:start position:0% +the statement if I'm following your + + + align:start position:0% +the statement if I'm following your +logic thank you so the same uniform your + + align:start position:0% +logic thank you so the same uniform your + + + align:start position:0% +logic thank you so the same uniform your +logic goes something like this + + align:start position:0% +logic goes something like this + + + align:start position:0% +logic goes something like this +look if we had the wave function which + + align:start position:0% +look if we had the wave function which + + + align:start position:0% +look if we had the wave function which +was Phi sub n times some phase some + + align:start position:0% +was Phi sub n times some phase some + + + align:start position:0% +was Phi sub n times some phase some +ridiculous phase let's say the phase is + + align:start position:0% +ridiculous phase let's say the phase is + + + align:start position:0% +ridiculous phase let's say the phase is +one if we had the wave functions Phi sub + + align:start position:0% +one if we had the wave functions Phi sub + + + align:start position:0% +one if we had the wave functions Phi sub +n what will the expectation value of the + + align:start position:0% +n what will the expectation value of the + + + align:start position:0% +n what will the expectation value of the +energy operator be in this state en + + align:start position:0% +energy operator be in this state en + + + align:start position:0% +energy operator be in this state en +right because it's the energy it's the + + align:start position:0% +right because it's the energy it's the + + + align:start position:0% +right because it's the energy it's the +sum over all possible ends of en times + + align:start position:0% +sum over all possible ends of en times + + + align:start position:0% +sum over all possible ends of en times +the probability that we measure en by + + align:start position:0% +the probability that we measure en by + + + align:start position:0% +the probability that we measure en by +definition but this is equal to sum over + + align:start position:0% +definition but this is equal to sum over + + + align:start position:0% +definition but this is equal to sum over +N of en times the expansion coefficient + + align:start position:0% +N of en times the expansion coefficient + + + align:start position:0% +N of en times the expansion coefficient +of our wave function + + align:start position:0% +of our wave function + + + align:start position:0% +of our wave function +in the energy eigenstate basis C N + + align:start position:0% +in the energy eigenstate basis C N + + + align:start position:0% +in the energy eigenstate basis C N +squared now what's the what's the + + align:start position:0% +squared now what's the what's the + + + align:start position:0% +squared now what's the what's the +expansion coefficient in our energy + + align:start position:0% +expansion coefficient in our energy + + + align:start position:0% +expansion coefficient in our energy +eigenbasis here it's one for a + + align:start position:0% +eigenbasis here it's one for a + + + align:start position:0% +eigenbasis here it's one for a +particular value of n and zero for + + align:start position:0% +particular value of n and zero for + + + align:start position:0% +particular value of n and zero for +everything else right so what will our + + align:start position:0% +everything else right so what will our + + + align:start position:0% +everything else right so what will our +answer be it will be zero for everything + + align:start position:0% +answer be it will be zero for everything + + + align:start position:0% +answer be it will be zero for everything +except one for a particular value yen + + align:start position:0% +except one for a particular value yen + + + align:start position:0% +except one for a particular value yen +corresponding to little n I should + + align:start position:0% +corresponding to little n I should + + + align:start position:0% +corresponding to little n I should +really call this mm so you know dummy + + align:start position:0% +really call this mm so you know dummy + + + align:start position:0% +really call this mm so you know dummy +variables that were summing over don't + + align:start position:0% +variables that were summing over don't + + + align:start position:0% +variables that were summing over don't +matter so for this particular case the + + align:start position:0% +matter so for this particular case the + + + align:start position:0% +matter so for this particular case the +expectation value of E is equal to en + + align:start position:0% +expectation value of E is equal to en + + + align:start position:0% +expectation value of E is equal to en +everyone call that so it certainly can + + align:start position:0% +everyone call that so it certainly can + + + align:start position:0% +everyone call that so it certainly can +be en but is this the only way to get in + + align:start position:0% +be en but is this the only way to get in + + + align:start position:0% +be en but is this the only way to get in +no so for example suppose we have Alpha + + align:start position:0% +no so for example suppose we have Alpha + + + align:start position:0% +no so for example suppose we have Alpha +Phi n or v 1 Phi 1 plus beta Phi 3 okay + + align:start position:0% +Phi n or v 1 Phi 1 plus beta Phi 3 okay + + + align:start position:0% +Phi n or v 1 Phi 1 plus beta Phi 3 okay +what will the answer be now first off in + + align:start position:0% +what will the answer be now first off in + + + align:start position:0% +what will the answer be now first off in +order to make this normalizable what is + + align:start position:0% +order to make this normalizable what is + + + align:start position:0% +order to make this normalizable what is +beta have to be it needs to be square of + + align:start position:0% +beta have to be it needs to be square of + + + align:start position:0% +beta have to be it needs to be square of +1 minus alpha norm squared right just so + + align:start position:0% +1 minus alpha norm squared right just so + + + align:start position:0% +1 minus alpha norm squared right just so +that they sum to 1 1 norm squared so + + align:start position:0% +that they sum to 1 1 norm squared so + + + align:start position:0% +that they sum to 1 1 norm squared so +what I want to plot now the expectation + + align:start position:0% +what I want to plot now the expectation + + + align:start position:0% +what I want to plot now the expectation +value of the energy as a function of + + align:start position:0% +value of the energy as a function of + + + align:start position:0% +value of the energy as a function of +alpha when alpha is zero what is the + + align:start position:0% +alpha when alpha is zero what is the + + + align:start position:0% +alpha when alpha is zero what is the +expectation value of the energy III when + + align:start position:0% +expectation value of the energy III when + + + align:start position:0% +expectation value of the energy III when +alpha is 1 which it can't be anything + + align:start position:0% +alpha is 1 which it can't be anything + + + align:start position:0% +alpha is 1 which it can't be anything +greater than well if alpha is 1 what is + + align:start position:0% +greater than well if alpha is 1 what is + + + align:start position:0% +greater than well if alpha is 1 what is +the expectation value of the energy e1 + + align:start position:0% +the expectation value of the energy e1 + + + align:start position:0% +the expectation value of the energy e1 +and how does the expectation value of + + align:start position:0% +and how does the expectation value of + + + align:start position:0% +and how does the expectation value of +the energy vary between these two as a + + align:start position:0% +the energy vary between these two as a + + + align:start position:0% +the energy vary between these two as a +function of alpha + + align:start position:0% +function of alpha + + + align:start position:0% +function of alpha +well it's smooth right and in particular + + align:start position:0% +well it's smooth right and in particular + + + align:start position:0% +well it's smooth right and in particular +it's in particular it's quadratic + + align:start position:0% +it's in particular it's quadratic + + + align:start position:0% +it's in particular it's quadratic +because goes like the square of these + + align:start position:0% +because goes like the square of these + + + align:start position:0% +because goes like the square of these +coefficients so it's something smooth + + align:start position:0% +coefficients so it's something smooth + + + align:start position:0% +coefficients so it's something smooth +that does this and have slope zero at + + align:start position:0% +that does this and have slope zero at + + + align:start position:0% +that does this and have slope zero at +the end ok and somewhere in between it + + align:start position:0% +the end ok and somewhere in between it + + + align:start position:0% +the end ok and somewhere in between it +will hit e to but there is not only is + + align:start position:0% +will hit e to but there is not only is + + + align:start position:0% +will hit e to but there is not only is +this not equal to two it doesn't even + + align:start position:0% +this not equal to two it doesn't even + + + align:start position:0% +this not equal to two it doesn't even +contain e2 as an element of the + + align:start position:0% +contain e2 as an element of the + + + align:start position:0% +contain e2 as an element of the +superposition right so this is a counter + + align:start position:0% +superposition right so this is a counter + + + align:start position:0% +superposition right so this is a counter +example to see every cool this is an + + align:start position:0% +example to see every cool this is an + + + align:start position:0% +example to see every cool this is an +important point now if I let the system + + align:start position:0% +important point now if I let the system + + + align:start position:0% +important point now if I let the system +if I know that at some moment in time + + align:start position:0% +if I know that at some moment in time + + + align:start position:0% +if I know that at some moment in time +the energy expectation value is this + + align:start position:0% +the energy expectation value is this + + + align:start position:0% +the energy expectation value is this +value corresponding say to some + + align:start position:0% +value corresponding say to some + + + align:start position:0% +value corresponding say to some +particular alpha and I let the system + + align:start position:0% +particular alpha and I let the system + + + align:start position:0% +particular alpha and I let the system +evolve in time how does that expectation + + align:start position:0% +evolve in time how does that expectation + + + align:start position:0% +evolve in time how does that expectation +value evolving + + align:start position:0% +value evolving + + + align:start position:0% +value evolving +time how does the expectation value of + + align:start position:0% +time how does the expectation value of + + + align:start position:0% +time how does the expectation value of +the energy change over time it doesn't + + align:start position:0% +the energy change over time it doesn't + + + align:start position:0% +the energy change over time it doesn't +the expectation value of energy is + + align:start position:0% +the expectation value of energy is + + + align:start position:0% +the expectation value of energy is +always time independent yeah + + align:start position:0% +always time independent yeah + + + align:start position:0% +always time independent yeah +does the expectation value of position + + align:start position:0% +does the expectation value of position + + + align:start position:0% +does the expectation value of position +change over time in general yes + + align:start position:0% +change over time in general yes + + + align:start position:0% +change over time in general yes +when does it not change over time in a + + align:start position:0% +when does it not change over time in a + + + align:start position:0% +when does it not change over time in a +stationary state right so this is + + align:start position:0% +stationary state right so this is + + + align:start position:0% +stationary state right so this is +exactly what this is working through + + align:start position:0% +exactly what this is working through + + + align:start position:0% +exactly what this is working through +this is what's on your previous problem + + align:start position:0% +this is what's on your previous problem + + + align:start position:0% +this is what's on your previous problem +set as well as on your current problem + + align:start position:0% +set as well as on your current problem + + + align:start position:0% +set as well as on your current problem +set yeah is this anything like + + align:start position:0% +set yeah is this anything like + + + align:start position:0% +set yeah is this anything like +conservation of energy + + align:start position:0% + + + + align:start position:0% + +excellent it sort of sounds like that + + align:start position:0% +excellent it sort of sounds like that + + + align:start position:0% +excellent it sort of sounds like that +will make a sharp version of that later + + align:start position:0% +will make a sharp version of that later + + + align:start position:0% +will make a sharp version of that later +so you should have that tinkling in the + + align:start position:0% +so you should have that tinkling in the + + + align:start position:0% +so you should have that tinkling in the +back of your head is like oh look we + + align:start position:0% +back of your head is like oh look we + + + align:start position:0% +back of your head is like oh look we +have a time independent potential energy + + align:start position:0% +have a time independent potential energy + + + align:start position:0% +have a time independent potential energy +is conserved that sounds kind of like + + align:start position:0% +is conserved that sounds kind of like + + + align:start position:0% +is conserved that sounds kind of like +the expectation value is constant but we + + align:start position:0% +the expectation value is constant but we + + + align:start position:0% +the expectation value is constant but we +need to make that more precise and we'll + + align:start position:0% +need to make that more precise and we'll + + + align:start position:0% +need to make that more precise and we'll +find a precise version of that statement + + align:start position:0% +find a precise version of that statement + + + align:start position:0% +find a precise version of that statement +later in the semester but it's a very + + align:start position:0% +later in the semester but it's a very + + + align:start position:0% +later in the semester but it's a very +good intuition to have other questions + + align:start position:0% +good intuition to have other questions + + + align:start position:0% +good intuition to have other questions +okay so the answer is D and you guys + + align:start position:0% +okay so the answer is D and you guys + + + align:start position:0% +okay so the answer is D and you guys +were about 4/5 on that at the end but + + align:start position:0% + + + + align:start position:0% + +that was not right okay next one this is + + align:start position:0% +that was not right okay next one this is + + + align:start position:0% +that was not right okay next one this is +a three step question we have observable + + align:start position:0% +a three step question we have observable + + + align:start position:0% +a three step question we have observable +a and B with eigen States i1 its IQ and + + align:start position:0% +a and B with eigen States i1 its IQ and + + + align:start position:0% +a and B with eigen States i1 its IQ and +phi1 and phi2 of a and b and eigen + + align:start position:0% +phi1 and phi2 of a and b and eigen + + + align:start position:0% +phi1 and phi2 of a and b and eigen +values a1 a2 and b1 b2 the eigen states + + align:start position:0% +values a1 a2 and b1 b2 the eigen states + + + align:start position:0% +values a1 a2 and b1 b2 the eigen states +are related in this linear fashion I + + align:start position:0% +are related in this linear fashion I + + + align:start position:0% +are related in this linear fashion I +measure observable a and get the value a + + align:start position:0% +measure observable a and get the value a + + + align:start position:0% +measure observable a and get the value a +1 what's the state immediately after + + align:start position:0% +1 what's the state immediately after + + + align:start position:0% +1 what's the state immediately after +that measurement what is the wave + + align:start position:0% +that measurement what is the wave + + + align:start position:0% +that measurement what is the wave +function + + align:start position:0% + + + + align:start position:0% + +alright five seconds to one-click ways + + align:start position:0% +alright five seconds to one-click ways + + + align:start position:0% +alright five seconds to one-click ways +okay great so there's pretty strong + + align:start position:0% +okay great so there's pretty strong + + + align:start position:0% +okay great so there's pretty strong +agreement among y'all that the answer is + + align:start position:0% +agreement among y'all that the answer is + + + align:start position:0% +agreement among y'all that the answer is +a and that is indeed the answer okay + + align:start position:0% +a and that is indeed the answer okay + + + align:start position:0% +a and that is indeed the answer okay +questions okay good so a slightly less + + align:start position:0% +questions okay good so a slightly less + + + align:start position:0% +questions okay good so a slightly less +obvious one immediately after this + + align:start position:0% +obvious one immediately after this + + + align:start position:0% +obvious one immediately after this +measurement of a the observable B is + + align:start position:0% +measurement of a the observable B is + + + align:start position:0% +measurement of a the observable B is +measured what's the probability that B 1 + + align:start position:0% +measured what's the probability that B 1 + + + align:start position:0% +measured what's the probability that B 1 +is found + + align:start position:0% + + + + align:start position:0% + +well there's some amazing initial + + align:start position:0% +well there's some amazing initial + + + align:start position:0% +well there's some amazing initial +transients there I could use this that + + align:start position:0% +transients there I could use this that + + + align:start position:0% +transients there I could use this that +could use the first couple of seconds as + + align:start position:0% +could use the first couple of seconds as + + + align:start position:0% +could use the first couple of seconds as +a random number generator move around + + align:start position:0% +a random number generator move around + + + align:start position:0% +a random number generator move around +okay that's it and and there's actually + + align:start position:0% +okay that's it and and there's actually + + + align:start position:0% +okay that's it and and there's actually +a third of you disagree with the correct + + align:start position:0% +a third of you disagree with the correct + + + align:start position:0% +a third of you disagree with the correct +answer so I'm gonna invite you to chat + + align:start position:0% +answer so I'm gonna invite you to chat + + + align:start position:0% +answer so I'm gonna invite you to chat +with each other + + align:start position:0% + + + + align:start position:0% + +all right + + align:start position:0% + + + + align:start position:0% + +go ahead and update your answers good + + align:start position:0% +go ahead and update your answers good + + + align:start position:0% +go ahead and update your answers good +okay five more seconds one second okay + + align:start position:0% +okay five more seconds one second okay + + + align:start position:0% +okay five more seconds one second okay +nice excellent you guys went from about + + align:start position:0% +nice excellent you guys went from about + + + align:start position:0% +nice excellent you guys went from about +65 percent to 90 percent so that was + + align:start position:0% +65 percent to 90 percent so that was + + + align:start position:0% +65 percent to 90 percent so that was +great the answer is e it's the norm + + align:start position:0% +great the answer is e it's the norm + + + align:start position:0% +great the answer is e it's the norm +squared of the coefficient of the the + + align:start position:0% +squared of the coefficient of the the + + + align:start position:0% +squared of the coefficient of the the +eigen value or eigen function + + align:start position:0% +eigen value or eigen function + + + align:start position:0% +eigen value or eigen function +corresponding to be one in the original + + align:start position:0% +corresponding to be one in the original + + + align:start position:0% +corresponding to be one in the original +state which was silent + + align:start position:0% +state which was silent + + + align:start position:0% +state which was silent +okay now imagine on the other hand that + + align:start position:0% +okay now imagine on the other hand that + + + align:start position:0% +okay now imagine on the other hand that +the grad student doing the measurement + + align:start position:0% +the grad student doing the measurement + + + align:start position:0% +the grad student doing the measurement +failed to in fact measure the observer + + align:start position:0% +failed to in fact measure the observer + + + align:start position:0% +failed to in fact measure the observer +will be it was a bad day but instead + + align:start position:0% +will be it was a bad day but instead + + + align:start position:0% +will be it was a bad day but instead +measure day again what's the probability + + align:start position:0% +measure day again what's the probability + + + align:start position:0% +measure day again what's the probability +that the second measurement will yield a + + align:start position:0% +that the second measurement will yield a + + + align:start position:0% +that the second measurement will yield a +one trust me on this one there's so many + + align:start position:0% +one trust me on this one there's so many + + + align:start position:0% +one trust me on this one there's so many +ways you know they read the package + + align:start position:0% +ways you know they read the package + + + align:start position:0% +ways you know they read the package +wrong you know they did the wrong + + align:start position:0% +wrong you know they did the wrong + + + align:start position:0% +wrong you know they did the wrong +measurement + + align:start position:0% + + + + align:start position:0% + +sorry thank you thank you thank you no + + align:start position:0% +sorry thank you thank you thank you no + + + align:start position:0% +sorry thank you thank you thank you no +no very good question + + align:start position:0% +no very good question + + + align:start position:0% +no very good question +he accidentally measured thee instead of + + align:start position:0% +he accidentally measured thee instead of + + + align:start position:0% +he accidentally measured thee instead of +a are you need a MBA into the be + + align:start position:0% +a are you need a MBA into the be + + + align:start position:0% +a are you need a MBA into the be +actually live today and see how easy it + + align:start position:0% +actually live today and see how easy it + + + align:start position:0% +actually live today and see how easy it +is to make that mistake the accidentally + + align:start position:0% +is to make that mistake the accidentally + + + align:start position:0% +is to make that mistake the accidentally +measured a instead of B I preached that + + align:start position:0% +measured a instead of B I preached that + + + align:start position:0% +measured a instead of B I preached that +was intentional okay so and we get a + + align:start position:0% +was intentional okay so and we get a + + + align:start position:0% +was intentional okay so and we get a +almost total unanimity the answer is B + + align:start position:0% +almost total unanimity the answer is B + + + align:start position:0% +almost total unanimity the answer is B +yes question great question let's just + + align:start position:0% +yes question great question let's just + + + align:start position:0% +yes question great question let's just +assume it's instantaneous + + align:start position:0% +assume it's instantaneous + + + align:start position:0% +assume it's instantaneous +maybe sloppy but he's very quick okay + + align:start position:0% +maybe sloppy but he's very quick okay + + + align:start position:0% +maybe sloppy but he's very quick okay +next question a system is in a state + + align:start position:0% +next question a system is in a state + + + align:start position:0% +next question a system is in a state +which is a linear superposition of N + + align:start position:0% +which is a linear superposition of N + + + align:start position:0% +which is a linear superposition of N +equals 1 and N equals 2 energy + + align:start position:0% +equals 1 and N equals 2 energy + + + align:start position:0% +equals 1 and N equals 2 energy +eigenstates bla what's the probability + + align:start position:0% +eigenstates bla what's the probability + + + align:start position:0% +eigenstates bla what's the probability +that measurement of the energy will + + align:start position:0% +that measurement of the energy will + + + align:start position:0% +that measurement of the energy will +yield the first energy eigenvalue + + align:start position:0% + + + + align:start position:0% + +another 5 seconds 5 great you guys + + align:start position:0% +another 5 seconds 5 great you guys + + + align:start position:0% +another 5 seconds 5 great you guys +totally agree that the answer is C ok + + align:start position:0% +totally agree that the answer is C ok + + + align:start position:0% +totally agree that the answer is C ok +great ok that's it that's it for that + + align:start position:0% +great ok that's it that's it for that + + + align:start position:0% +great ok that's it that's it for that +clicker questions for today um so here's + + align:start position:0% +clicker questions for today um so here's + + + align:start position:0% +clicker questions for today um so here's +the thing I want to emphasize the first + + align:start position:0% +the thing I want to emphasize the first + + + align:start position:0% +the thing I want to emphasize the first +is that these were totally conceptual + + align:start position:0% +is that these were totally conceptual + + + align:start position:0% +is that these were totally conceptual +they did not involve any computations + + align:start position:0% +they did not involve any computations + + + align:start position:0% +they did not involve any computations +and yet and yet they're they're not + + align:start position:0% +and yet and yet they're they're not + + + align:start position:0% +and yet and yet they're they're not +trivial some of them were really not + + align:start position:0% +trivial some of them were really not + + + align:start position:0% +trivial some of them were really not +some of them got you know 50 percent + + align:start position:0% +some of them got you know 50 percent + + + align:start position:0% +some of them got you know 50 percent +consistently across the class so it's + + align:start position:0% +consistently across the class so it's + + + align:start position:0% +consistently across the class so it's +not just the calculations that are hard + + align:start position:0% +not just the calculations that are hard + + + align:start position:0% +not just the calculations that are hard +just thinking through the the basic + + align:start position:0% +just thinking through the the basic + + + align:start position:0% +just thinking through the the basic +premises the basic postulates is really + + align:start position:0% +premises the basic postulates is really + + + align:start position:0% +premises the basic postulates is really +essential at this point it's more + + align:start position:0% +essential at this point it's more + + + align:start position:0% +essential at this point it's more +important than the computation yeah I + + align:start position:0% +important than the computation yeah I + + + align:start position:0% +important than the computation yeah I +will post these I will post these ok any + + align:start position:0% +will post these I will post these ok any + + + align:start position:0% +will post these I will post these ok any +questions remaining from after this + + align:start position:0% +questions remaining from after this + + + align:start position:0% +questions remaining from after this +little oh shoot you know I missed out on + + align:start position:0% +little oh shoot you know I missed out on + + + align:start position:0% +little oh shoot you know I missed out on +a whole opportunity um I'll do it next + + align:start position:0% +a whole opportunity um I'll do it next + + + align:start position:0% +a whole opportunity um I'll do it next +time + + align:start position:0% +time + + + align:start position:0% +time +whoo any other questions before we move + + align:start position:0% +whoo any other questions before we move + + + align:start position:0% +whoo any other questions before we move +on to the lecture part oh you totally + + align:start position:0% +on to the lecture part oh you totally + + + align:start position:0% +on to the lecture part oh you totally +have to wait + + align:start position:0% +have to wait + + + align:start position:0% +have to wait +and you totally have to wait okay any + + align:start position:0% +and you totally have to wait okay any + + + align:start position:0% +and you totally have to wait okay any +any other questions yeah well that's a + + align:start position:0% +any other questions yeah well that's a + + + align:start position:0% +any other questions yeah well that's a +very good question so the question is + + align:start position:0% +very good question so the question is + + + align:start position:0% +very good question so the question is +can you ever have a potential function + + align:start position:0% +can you ever have a potential function + + + align:start position:0% +can you ever have a potential function +that is odd so for example so let me + + align:start position:0% +that is odd so for example so let me + + + align:start position:0% +that is odd so for example so let me +you're actually asking two questions and + + align:start position:0% +you're actually asking two questions and + + + align:start position:0% +you're actually asking two questions and +let me disentangle them so one question + + align:start position:0% +let me disentangle them so one question + + + align:start position:0% +let me disentangle them so one question +is can I have an energy and then a + + align:start position:0% +is can I have an energy and then a + + + align:start position:0% +is can I have an energy and then a +potential function which is odd in and + + align:start position:0% +potential function which is odd in and + + + align:start position:0% +potential function which is odd in and +linear right + + align:start position:0% +linear right + + + align:start position:0% +linear right +so it just ramps all the way down so + + align:start position:0% +so it just ramps all the way down so + + + align:start position:0% +so it just ramps all the way down so +does that seem physical is the energy + + align:start position:0% +does that seem physical is the energy + + + align:start position:0% +does that seem physical is the energy +bounded from below no okay well that's + + align:start position:0% +bounded from below no okay well that's + + + align:start position:0% +bounded from below no okay well that's +not a terribly good criterion because + + align:start position:0% +not a terribly good criterion because + + + align:start position:0% +not a terribly good criterion because +it's not bounded from below for the + + align:start position:0% +it's not bounded from below for the + + + align:start position:0% +it's not bounded from below for the +Coulomb potential either all right but + + align:start position:0% +Coulomb potential either all right but + + + align:start position:0% +Coulomb potential either all right but +in the case of the Coulomb potential + + align:start position:0% +in the case of the Coulomb potential + + + align:start position:0% +in the case of the Coulomb potential +it's not bounded from below in a little + + align:start position:0% +it's not bounded from below in a little + + + align:start position:0% +it's not bounded from below in a little +tiny region right not you know in a huge + + align:start position:0% +tiny region right not you know in a huge + + + align:start position:0% +tiny region right not you know in a huge +swath so we're gonna need a better + + align:start position:0% +swath so we're gonna need a better + + + align:start position:0% +swath so we're gonna need a better +definition of this but the short answer + + align:start position:0% +definition of this but the short answer + + + align:start position:0% +definition of this but the short answer +to this one is no this is not good okay + + align:start position:0% +to this one is no this is not good okay + + + align:start position:0% +to this one is no this is not good okay +on the other hand it's not the oddness + + align:start position:0% +on the other hand it's not the oddness + + + align:start position:0% +on the other hand it's not the oddness +that's bad it's that the energy is + + align:start position:0% +that's bad it's that the energy is + + + align:start position:0% +that's bad it's that the energy is +continuing to be unbounded from below + + align:start position:0% +continuing to be unbounded from below + + + align:start position:0% +continuing to be unbounded from below +and here's what here so let me be more + + align:start position:0% +and here's what here so let me be more + + + align:start position:0% +and here's what here so let me be more +precise than saying it's not happy what + + align:start position:0% +precise than saying it's not happy what + + + align:start position:0% +precise than saying it's not happy what +is it what's important for an observable + + align:start position:0% +is it what's important for an observable + + + align:start position:0% +is it what's important for an observable +what's important for an observable the + + align:start position:0% +what's important for an observable the + + + align:start position:0% +what's important for an observable the +operator corresponding to an observable + + align:start position:0% +operator corresponding to an observable + + + align:start position:0% +operator corresponding to an observable +in quantum mechanics what property must + + align:start position:0% +in quantum mechanics what property must + + + align:start position:0% +in quantum mechanics what property must +that operator have it has to be + + align:start position:0% +that operator have it has to be + + + align:start position:0% +that operator have it has to be +hermitian right and empty oh that + + align:start position:0% +hermitian right and empty oh that + + + align:start position:0% +hermitian right and empty oh that +implies real eigenvalues it implies that + + align:start position:0% +implies real eigenvalues it implies that + + + align:start position:0% +implies real eigenvalues it implies that +there's a basis of its eigenfunctions + + align:start position:0% +there's a basis of its eigenfunctions + + + align:start position:0% +there's a basis of its eigenfunctions +all these nice things what we will find + + align:start position:0% +all these nice things what we will find + + + align:start position:0% +all these nice things what we will find +is that the Coulomb potential + + align:start position:0% +is that the Coulomb potential + + + align:start position:0% +is that the Coulomb potential +the hydrogen potential gives us a nice + + align:start position:0% +the hydrogen potential gives us a nice + + + align:start position:0% +the hydrogen potential gives us a nice +hermitian energy operator will prove + + align:start position:0% +hermitian energy operator will prove + + + align:start position:0% +hermitian energy operator will prove +that the energy operator self the joint + + align:start position:0% +that the energy operator self the joint + + + align:start position:0% +that the energy operator self the joint +on a problem set however this guy will + + align:start position:0% +on a problem set however this guy will + + + align:start position:0% +on a problem set however this guy will +not okay so we're gonna have a one that + + align:start position:0% +not okay so we're gonna have a one that + + + align:start position:0% +not okay so we're gonna have a one that +is not bounded from below and so while + + align:start position:0% +is not bounded from below and so while + + + align:start position:0% +is not bounded from below and so while +it's there's a sense in which its + + align:start position:0% +it's there's a sense in which its + + + align:start position:0% +it's there's a sense in which its +hermitian there's not a good sense in + + align:start position:0% +hermitian there's not a good sense in + + + align:start position:0% +hermitian there's not a good sense in +which it's it's got problems so but + + align:start position:0% +which it's it's got problems so but + + + align:start position:0% +which it's it's got problems so but +that's a more technical detail however + + align:start position:0% +that's a more technical detail however + + + align:start position:0% +that's a more technical detail however +there's a second part of your question + + align:start position:0% +there's a second part of your question + + + align:start position:0% +there's a second part of your question +which is you could have been asking a + + align:start position:0% +which is you could have been asking a + + + align:start position:0% +which is you could have been asking a +look can you have a potential that's odd + + align:start position:0% +look can you have a potential that's odd + + + align:start position:0% +look can you have a potential that's odd +but literally decide the diverging it + + align:start position:0% +but literally decide the diverging it + + + align:start position:0% +but literally decide the diverging it +and infinity so for example cuz you have + + align:start position:0% +and infinity so for example cuz you have + + + align:start position:0% +and infinity so for example cuz you have +a potential that does this so that it's + + align:start position:0% +a potential that does this so that it's + + + align:start position:0% +a potential that does this so that it's +odd but it it's bounded and that's fine + + align:start position:0% +odd but it it's bounded and that's fine + + + align:start position:0% +odd but it it's bounded and that's fine +nothing wrong with that so odd isn't the + + align:start position:0% +nothing wrong with that so odd isn't the + + + align:start position:0% +nothing wrong with that so odd isn't the +problem the problem is certain ways of + + align:start position:0% +problem the problem is certain ways of + + + align:start position:0% +problem the problem is certain ways of +diverging + + align:start position:0% +diverging + + + align:start position:0% +diverging +yeah so later does that mean so what + + align:start position:0% +yeah so later does that mean so what + + + align:start position:0% +yeah so later does that mean so what +would happen in the case where you did + + align:start position:0% +would happen in the case where you did + + + align:start position:0% +would happen in the case where you did +have some kind of linear potentially get + + align:start position:0% +have some kind of linear potentially get + + + align:start position:0% +have some kind of linear potentially get +a uniform electric field and something + + align:start position:0% +a uniform electric field and something + + + align:start position:0% +a uniform electric field and something +was moving is that like just is it is + + align:start position:0% +was moving is that like just is it is + + + align:start position:0% +was moving is that like just is it is +the problem that that potential + + align:start position:0% +the problem that that potential + + + align:start position:0% +the problem that that potential +technically isn't like a physical + + align:start position:0% +technically isn't like a physical + + + align:start position:0% +technically isn't like a physical +potential because it doesn't go away or + + align:start position:0% +potential because it doesn't go away or + + + align:start position:0% +potential because it doesn't go away or +well how would you ever build a linear + + align:start position:0% +well how would you ever build a linear + + + align:start position:0% +well how would you ever build a linear +potential right so the question here is + + align:start position:0% +potential right so the question here is + + + align:start position:0% +potential right so the question here is +looks I know how to build a linear + + align:start position:0% +looks I know how to build a linear + + + align:start position:0% +looks I know how to build a linear +potential turn on a uniform electric + + align:start position:0% +potential turn on a uniform electric + + + align:start position:0% +potential turn on a uniform electric +field and the electric field is a + + align:start position:0% +field and the electric field is a + + + align:start position:0% +field and the electric field is a +gradient to the electrostatic potential + + align:start position:0% +gradient to the electrostatic potential + + + align:start position:0% +gradient to the electrostatic potential +so that means the electrostatic + + align:start position:0% +so that means the electrostatic + + + align:start position:0% +so that means the electrostatic +potential is linear and the potential + + align:start position:0% +potential is linear and the potential + + + align:start position:0% +potential is linear and the potential +energy of a charged particle with charge + + align:start position:0% +energy of a charged particle with charge + + + align:start position:0% +energy of a charged particle with charge +Q in an electrostatic potential is Q + + align:start position:0% +Q in an electrostatic potential is Q + + + align:start position:0% +Q in an electrostatic potential is Q +times the electrostatic potential so the + + align:start position:0% +times the electrostatic potential so the + + + align:start position:0% +times the electrostatic potential so the +potential energy for that charged + + align:start position:0% +potential energy for that charged + + + align:start position:0% +potential energy for that charged +particle is a linear function so how do + + align:start position:0% +particle is a linear function so how do + + + align:start position:0% +particle is a linear function so how do +I build such thing well I take two + + align:start position:0% +I build such thing well I take two + + + align:start position:0% +I build such thing well I take two +capacitor plates and I dump some charge + + align:start position:0% +capacitor plates and I dump some charge + + + align:start position:0% +capacitor plates and I dump some charge +on this one in the opposite charge on + + align:start position:0% +on this one in the opposite charge on + + + align:start position:0% +on this one in the opposite charge on +this guy and I build up a linear + + align:start position:0% +this guy and I build up a linear + + + align:start position:0% +this guy and I build up a linear +potential well yeah exactly so that's + + align:start position:0% +potential well yeah exactly so that's + + + align:start position:0% +potential well yeah exactly so that's +the problem so can I build make this + + align:start position:0% +the problem so can I build make this + + + align:start position:0% +the problem so can I build make this +linear over an arbitrarily large domain + + align:start position:0% +linear over an arbitrarily large domain + + + align:start position:0% +linear over an arbitrarily large domain +no I need an arbitrarily large amount of + + align:start position:0% +no I need an arbitrarily large amount of + + + align:start position:0% +no I need an arbitrarily large amount of +charge and I need to push them apart + + align:start position:0% +charge and I need to push them apart + + + align:start position:0% +charge and I need to push them apart +from each other arbitrarily far which + + align:start position:0% +from each other arbitrarily far which + + + align:start position:0% +from each other arbitrarily far which +takes an arbitrarily large amount of + + align:start position:0% +takes an arbitrarily large amount of + + + align:start position:0% +takes an arbitrarily large amount of +work that's not terribly physical right + + align:start position:0% +work that's not terribly physical right + + + align:start position:0% +work that's not terribly physical right +your arms are only so big right so so at + + align:start position:0% +your arms are only so big right so so at + + + align:start position:0% +your arms are only so big right so so at +the end of the day we're always going to + + align:start position:0% +the end of the day we're always going to + + + align:start position:0% +the end of the day we're always going to +discover that the pathologies that show + + align:start position:0% +discover that the pathologies that show + + + align:start position:0% +discover that the pathologies that show +up in a potential like is like the + + align:start position:0% +up in a potential like is like the + + + align:start position:0% +up in a potential like is like the +Hamiltonian is not self adjoint and + + align:start position:0% +Hamiltonian is not self adjoint and + + + align:start position:0% +Hamiltonian is not self adjoint and +compactly supported space of complex + + align:start position:0% +compactly supported space of complex + + + align:start position:0% +compactly supported space of complex +supported l2 continuous functions then + + align:start position:0% +supported l2 continuous functions then + + + align:start position:0% +supported l2 continuous functions then +okay that's that's going to always be + + align:start position:0% +okay that's that's going to always be + + + align:start position:0% +okay that's that's going to always be +some mathematical version of your arms + + align:start position:0% +some mathematical version of your arms + + + align:start position:0% +some mathematical version of your arms +are only so big you cannot build an + + align:start position:0% +are only so big you cannot build an + + + align:start position:0% +are only so big you cannot build an +infinitely large apparatus like this so + + align:start position:0% +infinitely large apparatus like this so + + + align:start position:0% +infinitely large apparatus like this so +yes you're exactly right it is not + + align:start position:0% +yes you're exactly right it is not + + + align:start position:0% +yes you're exactly right it is not +physical is it a mathematical problem + + align:start position:0% +physical is it a mathematical problem + + + align:start position:0% +physical is it a mathematical problem +one could analyze yes one could write a + + align:start position:0% +one could analyze yes one could write a + + + align:start position:0% +one could analyze yes one could write a +dissertation on the celerity structure + + align:start position:0% +dissertation on the celerity structure + + + align:start position:0% +dissertation on the celerity structure +of these differential equations but that + + align:start position:0% +of these differential equations but that + + + align:start position:0% +of these differential equations but that +dissertation would never be read by a + + align:start position:0% +dissertation would never be read by a + + + align:start position:0% +dissertation would never be read by a +physicist other questions yeah + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% + + + + align:start position:0% + +excellent question no no so here's what + + align:start position:0% +excellent question no no so here's what + + + align:start position:0% +excellent question no no so here's what +you can do + + align:start position:0% +you can do + + + align:start position:0% +you can do +suppose I have a bunch of energy + + align:start position:0% +suppose I have a bunch of energy + + + align:start position:0% +suppose I have a bunch of energy +eigenstates I have some potential at + + align:start position:0% +eigenstates I have some potential at + + + align:start position:0% +eigenstates I have some potential at +some crease this is the potential + + align:start position:0% +some crease this is the potential + + + align:start position:0% +some crease this is the potential +it's a crazy potential right and it has + + align:start position:0% +it's a crazy potential right and it has + + + align:start position:0% +it's a crazy potential right and it has +some definite energy eigenvalues as + + align:start position:0% +some definite energy eigenvalues as + + + align:start position:0% +some definite energy eigenvalues as +we've shown in 1d we don't her as I've + + align:start position:0% +we've shown in 1d we don't her as I've + + + align:start position:0% +we've shown in 1d we don't her as I've +mentioned and proved in office hours we + + align:start position:0% +mentioned and proved in office hours we + + + align:start position:0% +mentioned and proved in office hours we +can't find degenerate eigen functions in + + align:start position:0% +can't find degenerate eigen functions in + + + align:start position:0% +can't find degenerate eigen functions in +a one dimensional potential so they're + + align:start position:0% +a one dimensional potential so they're + + + align:start position:0% +a one dimensional potential so they're +just they're not degenerate their space + + align:start position:0% +just they're not degenerate their space + + + align:start position:0% +just they're not degenerate their space +to find a distance part four four states + + align:start position:0% +to find a distance part four four states + + + align:start position:0% +to find a distance part four four states +for wave functions that converge it to + + align:start position:0% +for wave functions that converge it to + + + align:start position:0% +for wave functions that converge it to +zero at infinity for a bound States so I + + align:start position:0% +zero at infinity for a bound States so I + + + align:start position:0% +zero at infinity for a bound States so I +could always construct an operator which + + align:start position:0% +could always construct an operator which + + + align:start position:0% +could always construct an operator which +I will simply define in this way a and + + align:start position:0% +I will simply define in this way a and + + + align:start position:0% +I will simply define in this way a and +just for flourish I will put a dagger on + + align:start position:0% +just for flourish I will put a dagger on + + + align:start position:0% +just for flourish I will put a dagger on +it which does the following a dagger is + + align:start position:0% +it which does the following a dagger is + + + align:start position:0% +it which does the following a dagger is +the is defined as the operator that + + align:start position:0% +the is defined as the operator that + + + align:start position:0% +the is defined as the operator that +map's Phi n to Phi M and plus one right + + align:start position:0% +map's Phi n to Phi M and plus one right + + + align:start position:0% +map's Phi n to Phi M and plus one right +so what's the rule it takes this state + + align:start position:0% +so what's the rule it takes this state + + + align:start position:0% +so what's the rule it takes this state +to this state this state to this state + + align:start position:0% +to this state this state to this state + + + align:start position:0% +to this state this state to this state +this state to this a and since we can + + align:start position:0% +this state to this a and since we can + + + align:start position:0% +this state to this a and since we can +extend since these are a basis then that + + align:start position:0% +extend since these are a basis then that + + + align:start position:0% +extend since these are a basis then that +tells us how this acts on an arbitrary + + align:start position:0% +tells us how this acts on an arbitrary + + + align:start position:0% +tells us how this acts on an arbitrary +function because it acts on the + + align:start position:0% +function because it acts on the + + + align:start position:0% +function because it acts on the +superposition as acting on each term so + + align:start position:0% +superposition as acting on each term so + + + align:start position:0% +superposition as acting on each term so +we can define it in this way but here's + + align:start position:0% +we can define it in this way but here's + + + align:start position:0% +we can define it in this way but here's +the question what does it mean for the + + align:start position:0% +the question what does it mean for the + + + align:start position:0% +the question what does it mean for the +raising operator to be the raising + + align:start position:0% +raising operator to be the raising + + + align:start position:0% +raising operator to be the raising +operator it wasn't that it lifted the + + align:start position:0% +operator it wasn't that it lifted the + + + align:start position:0% +operator it wasn't that it lifted the +raise the operator that's not what + + align:start position:0% +raise the operator that's not what + + + align:start position:0% +raise the operator that's not what +started out the whole machinery where + + align:start position:0% +started out the whole machinery where + + + align:start position:0% +started out the whole machinery where +the raising operator got its juice was + + align:start position:0% +the raising operator got its juice was + + + align:start position:0% +the raising operator got its juice was +from this commutation relation a dagger + + align:start position:0% +from this commutation relation a dagger + + + align:start position:0% +from this commutation relation a dagger +with E was equal to H bar Omega a dagger + + align:start position:0% +with E was equal to H bar Omega a dagger + + + align:start position:0% +with E was equal to H bar Omega a dagger +right so can we build an operator a + + align:start position:0% +right so can we build an operator a + + + align:start position:0% +right so can we build an operator a +dagger that raises States and commutes + + align:start position:0% +dagger that raises States and commutes + + + align:start position:0% +dagger that raises States and commutes +with the energy operator in this fashion + + align:start position:0% +with the energy operator in this fashion + + + align:start position:0% +with the energy operator in this fashion +no that depends on the energy operator + + align:start position:0% +no that depends on the energy operator + + + align:start position:0% +no that depends on the energy operator +this is not a general property this is + + align:start position:0% +this is not a general property this is + + + align:start position:0% +this is not a general property this is +not always something we can do okay if + + align:start position:0% +not always something we can do okay if + + + align:start position:0% +not always something we can do okay if +we could then that energy operator would + + align:start position:0% +we could then that energy operator would + + + align:start position:0% +we could then that energy operator would +have evenly spaced energy eigenfunctions + + align:start position:0% +have evenly spaced energy eigenfunctions + + + align:start position:0% +have evenly spaced energy eigenfunctions +on the other hand it's not like it's + + align:start position:0% +on the other hand it's not like it's + + + align:start position:0% +on the other hand it's not like it's +never useful so consider the following + + align:start position:0% +never useful so consider the following + + + align:start position:0% +never useful so consider the following +example and I think this was on your + + align:start position:0% +example and I think this was on your + + + align:start position:0% +example and I think this was on your +promise up in our number so let me just + + align:start position:0% +promise up in our number so let me just + + + align:start position:0% +promise up in our number so let me just +say it + + align:start position:0% +say it + + + align:start position:0% +say it +consider the what if we write um a + + align:start position:0% +consider the what if we write um a + + + align:start position:0% +consider the what if we write um a +dagger a is equal to n right then the + + align:start position:0% +dagger a is equal to n right then the + + + align:start position:0% +dagger a is equal to n right then the +commutation relation for this so the + + align:start position:0% +commutation relation for this so the + + + align:start position:0% +commutation relation for this so the +energy operator for the harmonic + + align:start position:0% +energy operator for the harmonic + + + align:start position:0% +energy operator for the harmonic +oscillator was equal to H bar Omega n + + align:start position:0% +oscillator was equal to H bar Omega n + + + align:start position:0% +oscillator was equal to H bar Omega n +plus 1/2 right that's what we derived + + align:start position:0% +plus 1/2 right that's what we derived + + + align:start position:0% +plus 1/2 right that's what we derived +last time if we drive define a dagger a + + align:start position:0% +last time if we drive define a dagger a + + + align:start position:0% +last time if we drive define a dagger a +is n + + align:start position:0% +is n + + + align:start position:0% +is n +then commutator of n with a dagger is a + + align:start position:0% +then commutator of n with a dagger is a + + + align:start position:0% +then commutator of n with a dagger is a +dagger and the commutator of n with a is + + align:start position:0% +dagger and the commutator of n with a is + + + align:start position:0% +dagger and the commutator of n with a is +equal to minus a suppose the Hamiltonian + + align:start position:0% +equal to minus a suppose the Hamiltonian + + + align:start position:0% +equal to minus a suppose the Hamiltonian +or suppose the energy operator sorry + + align:start position:0% +or suppose the energy operator sorry + + + align:start position:0% +or suppose the energy operator sorry +the French suppose the energy operator + + align:start position:0% +the French suppose the energy operator + + + align:start position:0% +the French suppose the energy operator +is is equal to H bar Omega n plus and + + align:start position:0% +is is equal to H bar Omega n plus and + + + align:start position:0% +is is equal to H bar Omega n plus and +cubed okay does the raising operator + + align:start position:0% +cubed okay does the raising operator + + + align:start position:0% +cubed okay does the raising operator +commute with the energy operator to give + + align:start position:0% +commute with the energy operator to give + + + align:start position:0% +commute with the energy operator to give +you a dagger again no because it's going + + align:start position:0% +you a dagger again no because it's going + + + align:start position:0% +you a dagger again no because it's going +to give you a commutes to give you an a + + align:start position:0% +to give you a commutes to give you an a + + + align:start position:0% +to give you a commutes to give you an a +dagger and commutes with this guy to + + align:start position:0% +dagger and commutes with this guy to + + + align:start position:0% +dagger and commutes with this guy to +give you well a constant times n squared + + align:start position:0% +give you well a constant times n squared + + + align:start position:0% +give you well a constant times n squared +a dagger which is a slightly funny Beast + + align:start position:0% +a dagger which is a slightly funny Beast + + + align:start position:0% +a dagger which is a slightly funny Beast +so this doesn't have the same + + align:start position:0% +so this doesn't have the same + + + align:start position:0% +so this doesn't have the same +commutation relations on the other hand + + align:start position:0% +commutation relations on the other hand + + + align:start position:0% +commutation relations on the other hand +we know how to build the eigenfunctions + + align:start position:0% +we know how to build the eigenfunctions + + + align:start position:0% +we know how to build the eigenfunctions +of the ennop rater because they live in + + align:start position:0% +of the ennop rater because they live in + + + align:start position:0% +of the ennop rater because they live in +a tower by this algebra by this + + align:start position:0% +a tower by this algebra by this + + + align:start position:0% +a tower by this algebra by this +commutator relation they live in a tower + + align:start position:0% +commutator relation they live in a tower + + + align:start position:0% +commutator relation they live in a tower +so I can build the eigenfunctions of n + + align:start position:0% +so I can build the eigenfunctions of n + + + align:start position:0% +so I can build the eigenfunctions of n +and then I can take those eigenfunctions + + align:start position:0% +and then I can take those eigenfunctions + + + align:start position:0% +and then I can take those eigenfunctions +of n act on them with E and we'll + + align:start position:0% +of n act on them with E and we'll + + + align:start position:0% +of n act on them with E and we'll +discover that they're also eigen + + align:start position:0% +discover that they're also eigen + + + align:start position:0% +discover that they're also eigen +functions of e because yakking on them + + align:start position:0% +functions of e because yakking on them + + + align:start position:0% +functions of e because yakking on them +is just n and then cube backing on the + + align:start position:0% +is just n and then cube backing on the + + + align:start position:0% +is just n and then cube backing on the +eigenfunctions of n and then so they're + + align:start position:0% +eigenfunctions of n and then so they're + + + align:start position:0% +eigenfunctions of n and then so they're +high interest so the states with + + align:start position:0% +high interest so the states with + + + align:start position:0% +high interest so the states with +definite n are still eigenfunctions of + + align:start position:0% +definite n are still eigenfunctions of + + + align:start position:0% +definite n are still eigenfunctions of +the energy operator but they're not + + align:start position:0% +the energy operator but they're not + + + align:start position:0% +the energy operator but they're not +evenly spaced now can every potential be + + align:start position:0% +evenly spaced now can every potential be + + + align:start position:0% +evenly spaced now can every potential be +written in terms of this n operator so I + + align:start position:0% +written in terms of this n operator so I + + + align:start position:0% +written in terms of this n operator so I +leave that to you as an exercise the + + align:start position:0% +leave that to you as an exercise the + + + align:start position:0% +leave that to you as an exercise the +answer is no try it + + align:start position:0% + + + + align:start position:0% + +yeah exactly so if there's there's + + align:start position:0% +yeah exactly so if there's there's + + + align:start position:0% +yeah exactly so if there's there's +always something that you can formally + + align:start position:0% +always something that you can formally + + + align:start position:0% +always something that you can formally +define in this fashion it's not always + + align:start position:0% +define in this fashion it's not always + + + align:start position:0% +define in this fashion it's not always +useful to you because it doesn't always + + align:start position:0% +useful to you because it doesn't always + + + align:start position:0% +useful to you because it doesn't always +commute with the energy operator in some + + align:start position:0% +commute with the energy operator in some + + + align:start position:0% +commute with the energy operator in some +nice way right so now you can ask are + + align:start position:0% +nice way right so now you can ask are + + + align:start position:0% +nice way right so now you can ask are +there think properties that are nice + + align:start position:0% +there think properties that are nice + + + align:start position:0% +there think properties that are nice +about this well there's something called + + align:start position:0% +about this well there's something called + + + align:start position:0% +about this well there's something called +the super symmetric method in 1d quantum + + align:start position:0% +the super symmetric method in 1d quantum + + + align:start position:0% +the super symmetric method in 1d quantum +mechanics but that's sort of beyond the + + align:start position:0% +mechanics but that's sort of beyond the + + + align:start position:0% +mechanics but that's sort of beyond the +scope come to my office hours and ask me + + align:start position:0% +scope come to my office hours and ask me + + + align:start position:0% +scope come to my office hours and ask me +this question again this is a miracle of + + align:start position:0% +this question again this is a miracle of + + + align:start position:0% +this question again this is a miracle of +the harmonic oscillator other questions + + align:start position:0% +the harmonic oscillator other questions + + + align:start position:0% +the harmonic oscillator other questions +yeah to construct the ground state we + + align:start position:0% +yeah to construct the ground state we + + + align:start position:0% +yeah to construct the ground state we +use a condition that a five zero is zero + + align:start position:0% +use a condition that a five zero is zero + + + align:start position:0% +use a condition that a five zero is zero +yes did we like so how did we call them + + align:start position:0% +yes did we like so how did we call them + + + align:start position:0% +yes did we like so how did we call them +did we demand that on physical grounds + + align:start position:0% +did we demand that on physical grounds + + + align:start position:0% +did we demand that on physical grounds +that it had to be zero yes we did so + + align:start position:0% +that it had to be zero yes we did so + + + align:start position:0% +that it had to be zero yes we did so +excellent question so the question is + + align:start position:0% +excellent question so the question is + + + align:start position:0% +excellent question so the question is +this when we constructed using the + + align:start position:0% +this when we constructed using the + + + align:start position:0% +this when we constructed using the +operator method for the harmonic + + align:start position:0% +operator method for the harmonic + + + align:start position:0% +operator method for the harmonic +oscillator when we constructed the + + align:start position:0% +oscillator when we constructed the + + + align:start position:0% +oscillator when we constructed the +ground state we said the ground state by + + align:start position:0% +ground state we said the ground state by + + + align:start position:0% +ground state we said the ground state by +zero is that state which is annihilated + + align:start position:0% +zero is that state which is annihilated + + + align:start position:0% +zero is that state which is annihilated +by the lowering operator AFI zero is + + align:start position:0% +by the lowering operator AFI zero is + + + align:start position:0% +by the lowering operator AFI zero is +equal to zero so where did that come + + align:start position:0% +equal to zero so where did that come + + + align:start position:0% +equal to zero so where did that come +from why were we fortunate enough for + + align:start position:0% +from why were we fortunate enough for + + + align:start position:0% +from why were we fortunate enough for +physical reasons for mathematical + + align:start position:0% +physical reasons for mathematical + + + align:start position:0% +physical reasons for mathematical +reasons what was it what was the reason + + align:start position:0% +reasons what was it what was the reason + + + align:start position:0% +reasons what was it what was the reason +so this was room this was very important + + align:start position:0% +so this was room this was very important + + + align:start position:0% +so this was room this was very important +so let's go through it slowly so + + align:start position:0% +so let's go through it slowly so + + + align:start position:0% +so let's go through it slowly so +remember the step that came immediately + + align:start position:0% +remember the step that came immediately + + + align:start position:0% +remember the step that came immediately +before this step immediately before this + + align:start position:0% +before this step immediately before this + + + align:start position:0% +before this step immediately before this +step we said look the expectation value + + align:start position:0% +step we said look the expectation value + + + align:start position:0% +step we said look the expectation value +of energy can always be written as a + + align:start position:0% +of energy can always be written as a + + + align:start position:0% +of energy can always be written as a +strictly positive thing it's equal to + + align:start position:0% +strictly positive thing it's equal to + + + align:start position:0% +strictly positive thing it's equal to +the integral and you should derive this + + align:start position:0% +the integral and you should derive this + + + align:start position:0% +the integral and you should derive this +for yourself I didn't derive it but this + + align:start position:0% +for yourself I didn't derive it but this + + + align:start position:0% +for yourself I didn't derive it but this +is a good thing to derive for yourself + + align:start position:0% +is a good thing to derive for yourself + + + align:start position:0% +is a good thing to derive for yourself +it takes only a couple of steps integral + + align:start position:0% +it takes only a couple of steps integral + + + align:start position:0% +it takes only a couple of steps integral +over all momentum of sigh tilde of P + + align:start position:0% +over all momentum of sigh tilde of P + + + align:start position:0% +over all momentum of sigh tilde of P +before ei transformed norm squared this + + align:start position:0% +before ei transformed norm squared this + + + align:start position:0% +before ei transformed norm squared this +is the probability that you have given + + align:start position:0% +is the probability that you have given + + + align:start position:0% +is the probability that you have given +the state sign this is the probability + + align:start position:0% +the state sign this is the probability + + + align:start position:0% +the state sign this is the probability +density that you have momentum P P + + align:start position:0% +density that you have momentum P P + + + align:start position:0% +density that you have momentum P P +squared upon 2m plus the integral of DX + + align:start position:0% +squared upon 2m plus the integral of DX + + + align:start position:0% +squared upon 2m plus the integral of DX +Phi of X norm squared M Omega squared + + align:start position:0% +Phi of X norm squared M Omega squared + + + align:start position:0% +Phi of X norm squared M Omega squared +upon 2 x squared right it's the + + align:start position:0% +upon 2 x squared right it's the + + + align:start position:0% +upon 2 x squared right it's the +probability that you're at position x + + align:start position:0% +probability that you're at position x + + + align:start position:0% +probability that you're at position x +given the wave function X movements the + + align:start position:0% +given the wave function X movements the + + + align:start position:0% +given the wave function X movements the +value of the potential now this is a + + align:start position:0% +value of the potential now this is a + + + align:start position:0% +value of the potential now this is a +strictly positive quantity as is this + + align:start position:0% +strictly positive quantity as is this + + + align:start position:0% +strictly positive quantity as is this +strictly positive as is this that is a + + align:start position:0% +strictly positive as is this that is a + + + align:start position:0% +strictly positive as is this that is a +plus this quantity must always be + + align:start position:0% +plus this quantity must always be + + + align:start position:0% +plus this quantity must always be +greater than or equal to zero correct + + align:start position:0% +greater than or equal to zero correct + + + align:start position:0% +greater than or equal to zero correct +however we derive from the operator + + align:start position:0% +however we derive from the operator + + + align:start position:0% +however we derive from the operator +relations that if we take a wave + + align:start position:0% +relations that if we take a wave + + + align:start position:0% +relations that if we take a wave +function Phi sub n sorry Phi sub E and + + align:start position:0% +function Phi sub n sorry Phi sub E and + + + align:start position:0% +function Phi sub n sorry Phi sub E and +we act on it with the lowering operator + + align:start position:0% +we act on it with the lowering operator + + + align:start position:0% +we act on it with the lowering operator +a this defines a new state which up to + + align:start position:0% +a this defines a new state which up to + + + align:start position:0% +a this defines a new state which up to +some + + align:start position:0% +some + + + align:start position:0% +some +Malaysian is is an eigenfunction of the + + align:start position:0% +Malaysian is is an eigenfunction of the + + + align:start position:0% +Malaysian is is an eigenfunction of the +energy operator with energy e minus + + align:start position:0% +energy operator with energy e minus + + + align:start position:0% +energy operator with energy e minus +h-bar Omega and we show this by showing + + align:start position:0% +h-bar Omega and we show this by showing + + + align:start position:0% +h-bar Omega and we show this by showing +that the energy eigenfunction acting on + + align:start position:0% +that the energy eigenfunction acting on + + + align:start position:0% +that the energy eigenfunction acting on +this gives exactly this coefficient + + align:start position:0% +this gives exactly this coefficient + + + align:start position:0% +this gives exactly this coefficient +times this back + + align:start position:0% +times this back + + + align:start position:0% +times this back +it's an eigenfunction we just showed + + align:start position:0% +it's an eigenfunction we just showed + + + align:start position:0% +it's an eigenfunction we just showed +explicit it's an eigenfunction so this + + align:start position:0% +explicit it's an eigenfunction so this + + + align:start position:0% +explicit it's an eigenfunction so this +suggests that if you have a state with + + align:start position:0% +suggests that if you have a state with + + + align:start position:0% +suggests that if you have a state with +energy e you can also build a state with + + align:start position:0% +energy e you can also build a state with + + + align:start position:0% +energy e you can also build a state with +energy e minus h-bar Omega and thus we + + align:start position:0% +energy e minus h-bar Omega and thus we + + + align:start position:0% +energy e minus h-bar Omega and thus we +can repeat a minus 2 H bar Omega and + + align:start position:0% +can repeat a minus 2 H bar Omega and + + + align:start position:0% +can repeat a minus 2 H bar Omega and +it's Turtles all the way down the + + align:start position:0% +it's Turtles all the way down the + + + align:start position:0% +it's Turtles all the way down the +problem is for any finite value of e + + align:start position:0% +problem is for any finite value of e + + + align:start position:0% +problem is for any finite value of e +eventually this tower will get negative + + align:start position:0% +eventually this tower will get negative + + + align:start position:0% +eventually this tower will get negative +here zero but the energy expectation + + align:start position:0% +here zero but the energy expectation + + + align:start position:0% +here zero but the energy expectation +value cannot be less than zero it's got + + align:start position:0% +value cannot be less than zero it's got + + + align:start position:0% +value cannot be less than zero it's got +to be strictly greater than zero but if + + align:start position:0% +to be strictly greater than zero but if + + + align:start position:0% +to be strictly greater than zero but if +we were in this energy eigenstate and we + + align:start position:0% +we were in this energy eigenstate and we + + + align:start position:0% +we were in this energy eigenstate and we +measured the expectation value of energy + + align:start position:0% +measured the expectation value of energy + + + align:start position:0% +measured the expectation value of energy +this is the value we would get which + + align:start position:0% +this is the value we would get which + + + align:start position:0% +this is the value we would get which +would be negative + + align:start position:0% +would be negative + + + align:start position:0% +would be negative +oops that's a 2 so something is amiss + + align:start position:0% +oops that's a 2 so something is amiss + + + align:start position:0% +oops that's a 2 so something is amiss +how can this possibly make sense and the + + align:start position:0% +how can this possibly make sense and the + + + align:start position:0% +how can this possibly make sense and the +answer we came up with was well look + + align:start position:0% +answer we came up with was well look + + + align:start position:0% +answer we came up with was well look +it's inescapable that acting was a on + + align:start position:0% +it's inescapable that acting was a on + + + align:start position:0% +it's inescapable that acting was a on +Phi gives us something that's an + + align:start position:0% +Phi gives us something that's an + + + align:start position:0% +Phi gives us something that's an +eigenfunction of the energy + + align:start position:0% +eigenfunction of the energy + + + align:start position:0% +eigenfunction of the energy +it's possible that this I can that this + + align:start position:0% +it's possible that this I can that this + + + align:start position:0% +it's possible that this I can that this +function happens to be the zero function + + align:start position:0% +function happens to be the zero function + + + align:start position:0% +function happens to be the zero function +non zero energy just zero not a function + + align:start position:0% +non zero energy just zero not a function + + + align:start position:0% +non zero energy just zero not a function +is zero normalizable no the integral of + + align:start position:0% +is zero normalizable no the integral of + + + align:start position:0% +is zero normalizable no the integral of +zero squared is zero no coefficient + + align:start position:0% +zero squared is zero no coefficient + + + align:start position:0% +zero squared is zero no coefficient +times that is a finite number is one so + + align:start position:0% +times that is a finite number is one so + + + align:start position:0% +times that is a finite number is one so +the only way so what must happen is it + + align:start position:0% +the only way so what must happen is it + + + align:start position:0% +the only way so what must happen is it +must be true that at some point we can't + + align:start position:0% +must be true that at some point we can't + + + align:start position:0% +must be true that at some point we can't +lower anymore but we can always act with + + align:start position:0% +lower anymore but we can always act with + + + align:start position:0% +lower anymore but we can always act with +a so we can always try to lower the only + + align:start position:0% +a so we can always try to lower the only + + + align:start position:0% +a so we can always try to lower the only +out is if when we lower one particular + + align:start position:0% +out is if when we lower one particular + + + align:start position:0% +out is if when we lower one particular +guy which I will call Phi zero the only + + align:start position:0% +guy which I will call Phi zero the only + + + align:start position:0% +guy which I will call Phi zero the only +out is if we try to lower Phi zero we + + align:start position:0% +out is if we try to lower Phi zero we + + + align:start position:0% +out is if we try to lower Phi zero we +don't get another state which we assumed + + align:start position:0% +don't get another state which we assumed + + + align:start position:0% +don't get another state which we assumed +we did here we don't get another state + + align:start position:0% +we did here we don't get another state + + + align:start position:0% +we did here we don't get another state +instead we just get zero we get no state + + align:start position:0% +instead we just get zero we get no state + + + align:start position:0% +instead we just get zero we get no state +not energy zero zero the function is 0 + + align:start position:0% +not energy zero zero the function is 0 + + + align:start position:0% +not energy zero zero the function is 0 +identically vanishing this does not + + align:start position:0% +identically vanishing this does not + + + align:start position:0% +identically vanishing this does not +describe the configuration of a particle + + align:start position:0% +describe the configuration of a particle + + + align:start position:0% +describe the configuration of a particle +probability of it being anywhere is zero + + align:start position:0% +probability of it being anywhere is zero + + + align:start position:0% +probability of it being anywhere is zero +that's bad + + align:start position:0% + + + + align:start position:0% + +so in order for the tower to end in + + align:start position:0% +so in order for the tower to end in + + + align:start position:0% +so in order for the tower to end in +order for the energy to be bounded from + + align:start position:0% +order for the energy to be bounded from + + + align:start position:0% +order for the energy to be bounded from +below as the potential is we need that + + align:start position:0% +below as the potential is we need that + + + align:start position:0% +below as the potential is we need that +there's a lowest state in the tower that + + align:start position:0% +there's a lowest state in the tower that + + + align:start position:0% +there's a lowest state in the tower that +answer your question + + align:start position:0% +answer your question + + + align:start position:0% +answer your question +great yeah very good question you're + + align:start position:0% +great yeah very good question you're + + + align:start position:0% +great yeah very good question you're +gonna show this on the problem set if + + align:start position:0% +gonna show this on the problem set if + + + align:start position:0% +gonna show this on the problem set if +you haven't already I thought you did + + align:start position:0% +you haven't already I thought you did + + + align:start position:0% +you haven't already I thought you did +but maybe not um the energy + + align:start position:0% +but maybe not um the energy + + + align:start position:0% +but maybe not um the energy +eigenfunctions for the energy + + align:start position:0% +eigenfunctions for the energy + + + align:start position:0% +eigenfunctions for the energy +eigenfunctions cannot wait for for + + align:start position:0% +eigenfunctions cannot wait for for + + + align:start position:0% +eigenfunctions cannot wait for for +potentials with only bound states can + + align:start position:0% +potentials with only bound states can + + + align:start position:0% +potentials with only bound states can +always be expressed as purely real or a + + align:start position:0% +always be expressed as purely real or a + + + align:start position:0% +always be expressed as purely real or a +purely imaginary you can always + + align:start position:0% +purely imaginary you can always + + + align:start position:0% +purely imaginary you can always +decompose them in terms of purely real + + align:start position:0% +decompose them in terms of purely real + + + align:start position:0% +decompose them in terms of purely real +and purely imaginary proving that will + + align:start position:0% +and purely imaginary proving that will + + + align:start position:0% +and purely imaginary proving that will +be a problem on one of your problem sets + + align:start position:0% +be a problem on one of your problem sets + + + align:start position:0% +be a problem on one of your problem sets +but for the moment let me just say that + + align:start position:0% +but for the moment let me just say that + + + align:start position:0% +but for the moment let me just say that +yes you can always show that the the + + align:start position:0% +yes you can always show that the the + + + align:start position:0% +yes you can always show that the the +energy eigenfunctions and for 1d + + align:start position:0% +energy eigenfunctions and for 1d + + + align:start position:0% +energy eigenfunctions and for 1d +potential can always be expressed as + + align:start position:0% +potential can always be expressed as + + + align:start position:0% +potential can always be expressed as +purely real loop I need that bound state + + align:start position:0% +purely real loop I need that bound state + + + align:start position:0% +purely real loop I need that bound state +condition as we'll see later in the + + align:start position:0% +condition as we'll see later in the + + + align:start position:0% +condition as we'll see later in the +course yeah + + align:start position:0% + + + + align:start position:0% + +hu make it sorry no no no this sorry no + + align:start position:0% +hu make it sorry no no no this sorry no + + + align:start position:0% +hu make it sorry no no no this sorry no +good good good so what this says is + + align:start position:0% +good good good so what this says is + + + align:start position:0% +good good good so what this says is +given some state with energy e when we + + align:start position:0% +given some state with energy e when we + + + align:start position:0% +given some state with energy e when we +lower we get h-bar Omega less that + + align:start position:0% +lower we get h-bar Omega less that + + + align:start position:0% +lower we get h-bar Omega less that +doesn't tell you what he is good other + + align:start position:0% +doesn't tell you what he is good other + + + align:start position:0% +doesn't tell you what he is good other +questions yeah expand on that slowly if + + align:start position:0% +questions yeah expand on that slowly if + + + align:start position:0% +questions yeah expand on that slowly if +you get this zero function that doesn't + + align:start position:0% +you get this zero function that doesn't + + + align:start position:0% +you get this zero function that doesn't +actually correspond to any energy + + align:start position:0% +actually correspond to any energy + + + align:start position:0% +actually correspond to any energy +eigenvalue current little on zero + + align:start position:0% +eigenvalue current little on zero + + + align:start position:0% +eigenvalue current little on zero +Cranky's say any correct zero the + + align:start position:0% +Cranky's say any correct zero the + + + align:start position:0% +Cranky's say any correct zero the +function zero is an eigenfunction of + + align:start position:0% +function zero is an eigenfunction of + + + align:start position:0% +function zero is an eigenfunction of +every operator but it's a stupid + + align:start position:0% +every operator but it's a stupid + + + align:start position:0% +every operator but it's a stupid +eigenfunction of every operator in + + align:start position:0% +eigenfunction of every operator in + + + align:start position:0% +eigenfunction of every operator in +particular it has nothing to do with the + + align:start position:0% +particular it has nothing to do with the + + + align:start position:0% +particular it has nothing to do with the +states we're interested in we are + + align:start position:0% +states we're interested in we are + + + align:start position:0% +states we're interested in we are +interested in normalizable states right + + align:start position:0% +interested in normalizable states right + + + align:start position:0% +interested in normalizable states right +and that is an auto normalizable state + + align:start position:0% +and that is an auto normalizable state + + + align:start position:0% +and that is an auto normalizable state +you can't multiply by any finite + + align:start position:0% +you can't multiply by any finite + + + align:start position:0% +you can't multiply by any finite +coefficient and get one when you square + + align:start position:0% +coefficient and get one when you square + + + align:start position:0% +coefficient and get one when you square +integrate it okay yep one last question + + align:start position:0% + + + + align:start position:0% + +well you we need to add more words that + + align:start position:0% +well you we need to add more words that + + + align:start position:0% +well you we need to add more words that +so the question is does that mean that + + align:start position:0% +so the question is does that mean that + + + align:start position:0% +so the question is does that mean that +the that the only particle that could + + align:start position:0% +the that the only particle that could + + + align:start position:0% +the that the only particle that could +really have zero energy is some + + align:start position:0% +really have zero energy is some + + + align:start position:0% +really have zero energy is some +imaginary particle that doesn't exist + + align:start position:0% +imaginary particle that doesn't exist + + + align:start position:0% +imaginary particle that doesn't exist +first off imaginary particles may exist + + align:start position:0% +first off imaginary particles may exist + + + align:start position:0% +first off imaginary particles may exist +and we just haven't seen them I mean + + align:start position:0% + + + + align:start position:0% + +right okay so so I need to say two + + align:start position:0% +right okay so so I need to say two + + + align:start position:0% +right okay so so I need to say two +things about this so there's a technical + + align:start position:0% +things about this so there's a technical + + + align:start position:0% +things about this so there's a technical +complaint I need to make about your + + align:start position:0% +complaint I need to make about your + + + align:start position:0% +complaint I need to make about your +question which is a very fair question + + align:start position:0% +question which is a very fair question + + + align:start position:0% +question which is a very fair question +but I need to make it all the same and + + align:start position:0% +but I need to make it all the same and + + + align:start position:0% +but I need to make it all the same and +the second is a more physical answer so + + align:start position:0% +the second is a more physical answer so + + + align:start position:0% +the second is a more physical answer so +the technical complaint is what do you + + align:start position:0% +the technical complaint is what do you + + + align:start position:0% +the technical complaint is what do you +mean by zero energy + + align:start position:0% +mean by zero energy + + + align:start position:0% +mean by zero energy +do you ever measure an energy directly + + align:start position:0% +do you ever measure an energy directly + + + align:start position:0% +do you ever measure an energy directly +and you measure energy differences right + + align:start position:0% +and you measure energy differences right + + + align:start position:0% +and you measure energy differences right +so relative to what we have to decide + + align:start position:0% +so relative to what we have to decide + + + align:start position:0% +so relative to what we have to decide +relative to what so for example in the + + align:start position:0% +relative to what so for example in the + + + align:start position:0% +relative to what so for example in the +harmonic oscillator what we mean when we + + align:start position:0% +harmonic oscillator what we mean when we + + + align:start position:0% +harmonic oscillator what we mean when we +say that grad student energy is nonzero + + align:start position:0% +say that grad student energy is nonzero + + + align:start position:0% +say that grad student energy is nonzero +is if we draw the potential and we call + + align:start position:0% +is if we draw the potential and we call + + + align:start position:0% +is if we draw the potential and we call +the minimum of the potential is zero + + align:start position:0% +the minimum of the potential is zero + + + align:start position:0% +the minimum of the potential is zero +classically a zero then what we discover + + align:start position:0% +classically a zero then what we discover + + + align:start position:0% +classically a zero then what we discover +is that the energy of the quantum + + align:start position:0% +is that the energy of the quantum + + + align:start position:0% +is that the energy of the quantum +mechanical ground state is one-half H + + align:start position:0% +mechanical ground state is one-half H + + + align:start position:0% +mechanical ground state is one-half H +bar Omega right above zero so is there + + align:start position:0% +bar Omega right above zero so is there + + + align:start position:0% +bar Omega right above zero so is there +any state of the harmonic oscillator + + align:start position:0% +any state of the harmonic oscillator + + + align:start position:0% +any state of the harmonic oscillator +with energy zero no okay now if we have + + align:start position:0% +with energy zero no okay now if we have + + + align:start position:0% +with energy zero no okay now if we have +a free particle is there is there a + + align:start position:0% +a free particle is there is there a + + + align:start position:0% +a free particle is there is there a +configuration with energy zero wow + + align:start position:0% +configuration with energy zero wow + + + align:start position:0% +configuration with energy zero wow +that's an interesting question so what + + align:start position:0% +that's an interesting question so what + + + align:start position:0% +that's an interesting question so what +are the ground what are the eigenstates + + align:start position:0% +are the ground what are the eigenstates + + + align:start position:0% +are the ground what are the eigenstates +e to the ikx okay when the energy is + + align:start position:0% +e to the ikx okay when the energy is + + + align:start position:0% +e to the ikx okay when the energy is +zero + + align:start position:0% +zero + + + align:start position:0% +zero +so and the energy is because it's just P + + align:start position:0% +so and the energy is because it's just P + + + align:start position:0% +so and the energy is because it's just P +squared upon 2m which is H bar squared K + + align:start position:0% +squared upon 2m which is H bar squared K + + + align:start position:0% +squared upon 2m which is H bar squared K +squared upon 2m the energy is H bar + + align:start position:0% +squared upon 2m the energy is H bar + + + align:start position:0% +squared upon 2m the energy is H bar +squared K squared upon 2m for a free + + align:start position:0% +squared K squared upon 2m for a free + + + align:start position:0% +squared K squared upon 2m for a free +particle no potential and by zeroing the + + align:start position:0% +particle no potential and by zeroing the + + + align:start position:0% +particle no potential and by zeroing the +asymptotic energy u equals zero can you + + align:start position:0% +asymptotic energy u equals zero can you + + + align:start position:0% +asymptotic energy u equals zero can you +have a state with energy zero this one's + + align:start position:0% +have a state with energy zero this one's + + + align:start position:0% +have a state with energy zero this one's +a little subtle because if we take the + + align:start position:0% +a little subtle because if we take the + + + align:start position:0% +a little subtle because if we take the +energy zero what must K be zero okay + + align:start position:0% +energy zero what must K be zero okay + + + align:start position:0% +energy zero what must K be zero okay +great so what's the wave function + + align:start position:0% +great so what's the wave function + + + align:start position:0% +great so what's the wave function +constant is that normalizable not so + + align:start position:0% +constant is that normalizable not so + + + align:start position:0% +constant is that normalizable not so +much so can you build a wave packet with + + align:start position:0% +much so can you build a wave packet with + + + align:start position:0% +much so can you build a wave packet with +energy zero carica sorry let me not say + + align:start position:0% +energy zero carica sorry let me not say + + + align:start position:0% +energy zero carica sorry let me not say +that can you put a single particle in a + + align:start position:0% +that can you put a single particle in a + + + align:start position:0% +that can you put a single particle in a +state with energy zero no that would not + + align:start position:0% +state with energy zero no that would not + + + align:start position:0% +state with energy zero no that would not +seem to be possible because that would + + align:start position:0% +seem to be possible because that would + + + align:start position:0% +seem to be possible because that would +be non-normalizable state well you say + + align:start position:0% +be non-normalizable state well you say + + + align:start position:0% +be non-normalizable state well you say +we deal with these Exponential's all the + + align:start position:0% +we deal with these Exponential's all the + + + align:start position:0% +we deal with these Exponential's all the +time + + align:start position:0% +time + + + align:start position:0% +time +we know how to deal with that we don't + + align:start position:0% +we know how to deal with that we don't + + + align:start position:0% +we know how to deal with that we don't +use a single wave plane wave we use a + + align:start position:0% +use a single wave plane wave we use a + + + align:start position:0% +use a single wave plane wave we use a +wave packet with some width right so I + + align:start position:0% +wave packet with some width right so I + + + align:start position:0% +wave packet with some width right so I +can build a wave packet with you know + + align:start position:0% +can build a wave packet with you know + + + align:start position:0% +can build a wave packet with you know +some average width but will that average + + align:start position:0% +some average width but will that average + + + align:start position:0% +some average width but will that average +width ever have expectation value of K + + align:start position:0% +width ever have expectation value of K + + + align:start position:0% +width ever have expectation value of K +equals zero + + align:start position:0% +equals zero + + + align:start position:0% +equals zero +no because we'll always have + + align:start position:0% +no because we'll always have + + + align:start position:0% +no because we'll always have +contributions from K naught equals zero + + align:start position:0% +contributions from K naught equals zero + + + align:start position:0% +contributions from K naught equals zero +so that it's localized so that it + + align:start position:0% +so that it's localized so that it + + + align:start position:0% +so that it's localized so that it +spatially localized so can you build a + + align:start position:0% +spatially localized so can you build a + + + align:start position:0% +spatially localized so can you build a +normalizable state with energies here + + align:start position:0% +normalizable state with energies here + + + align:start position:0% +normalizable state with energies here +which is an eigenfunction of the energy + + align:start position:0% +which is an eigenfunction of the energy + + + align:start position:0% +which is an eigenfunction of the energy +theorem no not in this case either so + + align:start position:0% +theorem no not in this case either so + + + align:start position:0% +theorem no not in this case either so +there's the technical complaint that you + + align:start position:0% +there's the technical complaint that you + + + align:start position:0% +there's the technical complaint that you +need to talk about what you mean + + align:start position:0% +need to talk about what you mean + + + align:start position:0% +need to talk about what you mean +relative to what that was about your + + align:start position:0% +relative to what that was about your + + + align:start position:0% +relative to what that was about your +question and the second of can you ever + + align:start position:0% +question and the second of can you ever + + + align:start position:0% +question and the second of can you ever +have an energy eigenstate which is that + + align:start position:0% +have an energy eigenstate which is that + + + align:start position:0% +have an energy eigenstate which is that +the minimum of the potential and that's + + align:start position:0% +the minimum of the potential and that's + + + align:start position:0% +the minimum of the potential and that's +also zero that's also no you'll actually + + align:start position:0% +also zero that's also no you'll actually + + + align:start position:0% +also zero that's also no you'll actually +prove that on a later problem set okay + + align:start position:0% +prove that on a later problem set okay + + + align:start position:0% +prove that on a later problem set okay +so um with all that said we now have a + + align:start position:0% +so um with all that said we now have a + + + align:start position:0% +so um with all that said we now have a +mirror that's awesome 15 minutes for a + + align:start position:0% +mirror that's awesome 15 minutes for a + + + align:start position:0% +mirror that's awesome 15 minutes for a +14 page lecture so can I do this fast no + + align:start position:0% +14 page lecture so can I do this fast no + + + align:start position:0% +14 page lecture so can I do this fast no +I'm kidding um I won't do that to you so + + align:start position:0% +I'm kidding um I won't do that to you so + + + align:start position:0% +I'm kidding um I won't do that to you so +I want to just instead of going through + + align:start position:0% +I want to just instead of going through + + + align:start position:0% +I want to just instead of going through +so this was not directly relevant for + + align:start position:0% +so this was not directly relevant for + + + align:start position:0% +so this was not directly relevant for +the exam and it's also um yeah this can + + align:start position:0% +the exam and it's also um yeah this can + + + align:start position:0% +the exam and it's also um yeah this can +come a little bit later so let me let me + + align:start position:0% +come a little bit later so let me let me + + + align:start position:0% +come a little bit later so let me let me +just do a couple let me show you a + + align:start position:0% +just do a couple let me show you a + + + align:start position:0% +just do a couple let me show you a +couple of quick things so the notes are + + align:start position:0% +couple of quick things so the notes are + + + align:start position:0% +couple of quick things so the notes are +posted online look at them I'll go over + + align:start position:0% +posted online look at them I'll go over + + + align:start position:0% +posted online look at them I'll go over +them again in the future what do I want + + align:start position:0% +them again in the future what do I want + + + align:start position:0% +them again in the future what do I want +to do so I want to introduce to you two + + align:start position:0% +to do so I want to introduce to you two + + + align:start position:0% +to do so I want to introduce to you two +ideas one is direct notation and this is + + align:start position:0% +ideas one is direct notation and this is + + + align:start position:0% +ideas one is direct notation and this is +harkening back to basics of vector + + align:start position:0% +harkening back to basics of vector + + + align:start position:0% +harkening back to basics of vector +spaces and the second is i want to tell + + align:start position:0% +spaces and the second is i want to tell + + + align:start position:0% +spaces and the second is i want to tell +you something about what the commutator + + align:start position:0% +you something about what the commutator + + + align:start position:0% +you something about what the commutator +means so first off let me ask you guys a + + align:start position:0% +means so first off let me ask you guys a + + + align:start position:0% +means so first off let me ask you guys a +question now I can use I have one more + + align:start position:0% +question now I can use I have one more + + + align:start position:0% +question now I can use I have one more +clicker question for you + + align:start position:0% + + + + align:start position:0% + +all right y'all ready everyone up with + + align:start position:0% +all right y'all ready everyone up with + + + align:start position:0% +all right y'all ready everyone up with +ya okay everyone everyone up with the + + align:start position:0% +ya okay everyone everyone up with the + + + align:start position:0% +ya okay everyone everyone up with the +clickers okay here is a question + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +when you go ahead and start clicking now + + align:start position:0% +when you go ahead and start clicking now + + + align:start position:0% +when you go ahead and start clicking now +[Music] + + align:start position:0% + + + + align:start position:0% + +Sigma is the uncertainty sorry Sigma is + + align:start position:0% +Sigma is the uncertainty sorry Sigma is + + + align:start position:0% +Sigma is the uncertainty sorry Sigma is +young certainty this is awesome I swear + + align:start position:0% +young certainty this is awesome I swear + + + align:start position:0% +young certainty this is awesome I swear +the clicks are going in beat with the + + align:start position:0% +the clicks are going in beat with the + + + align:start position:0% +the clicks are going in beat with the +music okay so at the moment so let me + + align:start position:0% +music okay so at the moment so let me + + + align:start position:0% +music okay so at the moment so let me +give you three more seconds one two + + align:start position:0% +give you three more seconds one two + + + align:start position:0% +give you three more seconds one two +three okay this is awesome you guys are + + align:start position:0% +three okay this is awesome you guys are + + + align:start position:0% +three okay this is awesome you guys are +totally at chance you have even + + align:start position:0% +totally at chance you have even + + + align:start position:0% +totally at chance you have even +probability distribution across the + + align:start position:0% +probability distribution across the + + + align:start position:0% +probability distribution across the +three so this is good because we haven't + + align:start position:0% +three so this is good because we haven't + + + align:start position:0% +three so this is good because we haven't +actually introduced this idea yet in a + + align:start position:0% +actually introduced this idea yet in a + + + align:start position:0% +actually introduced this idea yet in a +you know four so let me quickly talk you + + align:start position:0% +you know four so let me quickly talk you + + + align:start position:0% +you know four so let me quickly talk you +through this okay so yeah we've it off + + align:start position:0% +through this okay so yeah we've it off + + + align:start position:0% +through this okay so yeah we've it off +so so let me quickly quickly talk you + + align:start position:0% +so so let me quickly quickly talk you + + + align:start position:0% +so so let me quickly quickly talk you +through this and this is important this + + align:start position:0% +through this and this is important this + + + align:start position:0% +through this and this is important this +is going to give you some intuition for + + align:start position:0% +is going to give you some intuition for + + + align:start position:0% +is going to give you some intuition for +what on what uncertainty means and it's + + align:start position:0% +what on what uncertainty means and it's + + + align:start position:0% +what on what uncertainty means and it's +also going to give you some intuition + + align:start position:0% +also going to give you some intuition + + + align:start position:0% +also going to give you some intuition +for what the commutator means okay so + + align:start position:0% +for what the commutator means okay so + + + align:start position:0% +for what the commutator means okay so +this is a little more experience a + + align:start position:0% +this is a little more experience a + + + align:start position:0% +this is a little more experience a +little more practice with operators and + + align:start position:0% +little more practice with operators and + + + align:start position:0% +little more practice with operators and +we'll pick up on the direct notation and + + align:start position:0% +we'll pick up on the direct notation and + + + align:start position:0% +we'll pick up on the direct notation and +everything I think next time because I + + align:start position:0% +everything I think next time because I + + + align:start position:0% +everything I think next time because I +just want to get through this physics so + + align:start position:0% +just want to get through this physics so + + + align:start position:0% +just want to get through this physics so +consider two operators a and B so a and + + align:start position:0% +consider two operators a and B so a and + + + align:start position:0% +consider two operators a and B so a and +B are my two operators they have hats he + + align:start position:0% +B are my two operators they have hats he + + + align:start position:0% +B are my two operators they have hats he +has a top hat so we have you've got to + + align:start position:0% +has a top hat so we have you've got to + + + align:start position:0% +has a top hat so we have you've got to +make this stuff a little more + + align:start position:0% +make this stuff a little more + + + align:start position:0% +make this stuff a little more +lighthearted so we have two operators a + + align:start position:0% +lighthearted so we have two operators a + + + align:start position:0% +lighthearted so we have two operators a +and B and I want to ask is it possible + + align:start position:0% +and B and I want to ask is it possible + + + align:start position:0% +and B and I want to ask is it possible +for there to be a function by little a + + align:start position:0% +for there to be a function by little a + + + align:start position:0% +for there to be a function by little a +little B which is simultaneously an + + align:start position:0% +little B which is simultaneously an + + + align:start position:0% +little B which is simultaneously an +eigenfunction of a and an eigenfunction + + align:start position:0% +eigenfunction of a and an eigenfunction + + + align:start position:0% +eigenfunction of a and an eigenfunction +of B so now we're just this is a pure + + align:start position:0% +of B so now we're just this is a pure + + + align:start position:0% +of B so now we're just this is a pure +math question given two operators a and + + align:start position:0% +math question given two operators a and + + + align:start position:0% +math question given two operators a and +B can you build a function which is + + align:start position:0% +B can you build a function which is + + + align:start position:0% +B can you build a function which is +simultaneously an eigenfunction of a and + + align:start position:0% +simultaneously an eigenfunction of a and + + + align:start position:0% +simultaneously an eigenfunction of a and +an eigenfunction of b I will call this + + align:start position:0% +an eigenfunction of b I will call this + + + align:start position:0% +an eigenfunction of b I will call this +Phi baby yo why not okay so Phi sub a B + + align:start position:0% +Phi baby yo why not okay so Phi sub a B + + + align:start position:0% +Phi baby yo why not okay so Phi sub a B +has this property a on Phi a B is equal + + align:start position:0% +has this property a on Phi a B is equal + + + align:start position:0% +has this property a on Phi a B is equal +to a Phi B why not and B on Phi a B is a + + align:start position:0% +to a Phi B why not and B on Phi a B is a + + + align:start position:0% +to a Phi B why not and B on Phi a B is a +little beyond Phi B you can't stop me I + + align:start position:0% +little beyond Phi B you can't stop me I + + + align:start position:0% +little beyond Phi B you can't stop me I +have now created this OP this object + + align:start position:0% +have now created this OP this object + + + align:start position:0% +have now created this OP this object +what from the existence of this state + + align:start position:0% +what from the existence of this state + + + align:start position:0% +what from the existence of this state +what can you deduce about the operators + + align:start position:0% +what can you deduce about the operators + + + align:start position:0% +what can you deduce about the operators +a and B and if you've already seen this + + align:start position:0% +a and B and if you've already seen this + + + align:start position:0% +a and B and if you've already seen this +before that's cheating so don't raise + + align:start position:0% +before that's cheating so don't raise + + + align:start position:0% +before that's cheating so don't raise +your hand but if you haven't seen this + + align:start position:0% +your hand but if you haven't seen this + + + align:start position:0% +your hand but if you haven't seen this +before just think through what what what + + align:start position:0% +before just think through what what what + + + align:start position:0% +before just think through what what what +does this tell you about the operators a + + align:start position:0% +does this tell you about the operators a + + + align:start position:0% +does this tell you about the operators a +and B + + align:start position:0% + + + + align:start position:0% + +great + + align:start position:0% +great + + + align:start position:0% +great +that's a nice guess I like that guess so + + align:start position:0% +that's a nice guess I like that guess so + + + align:start position:0% +that's a nice guess I like that guess so +so let's check okay so what would it + + align:start position:0% +so let's check okay so what would it + + + align:start position:0% +so let's check okay so what would it +mean for the commutator of a and B to be + + align:start position:0% +mean for the commutator of a and B to be + + + align:start position:0% +mean for the commutator of a and B to be +0 so if so a B is some so this is equal + + align:start position:0% +0 so if so a B is some so this is equal + + + align:start position:0% +0 so if so a B is some so this is equal +to a B minus B a and what the commutator + + align:start position:0% +to a B minus B a and what the commutator + + + align:start position:0% +to a B minus B a and what the commutator +does is it takes two operators and it + + align:start position:0% +does is it takes two operators and it + + + align:start position:0% +does is it takes two operators and it +gives you a new operator called bracket + + align:start position:0% +gives you a new operator called bracket + + + align:start position:0% +gives you a new operator called bracket +a B sometimes it's useful to call it C + + align:start position:0% +a B sometimes it's useful to call it C + + + align:start position:0% +a B sometimes it's useful to call it C +for commutator so it gives you a new + + align:start position:0% +for commutator so it gives you a new + + + align:start position:0% +for commutator so it gives you a new +operator giving two operators you build + + align:start position:0% +operator giving two operators you build + + + align:start position:0% +operator giving two operators you build +a new operator and saying that this so + + align:start position:0% +a new operator and saying that this so + + + align:start position:0% +a new operator and saying that this so +good and suppose now that we have a + + align:start position:0% +good and suppose now that we have a + + + align:start position:0% +good and suppose now that we have a +common eigen function of a and B what + + align:start position:0% +common eigen function of a and B what + + + align:start position:0% +common eigen function of a and B what +does it tell you well let's take the + + align:start position:0% +does it tell you well let's take the + + + align:start position:0% +does it tell you well let's take the +commutator a B and let's take it and act + + align:start position:0% +commutator a B and let's take it and act + + + align:start position:0% +commutator a B and let's take it and act +on five sub a B on this common + + align:start position:0% +on five sub a B on this common + + + align:start position:0% +on five sub a B on this common +eigenstate so what is this equal to this + + align:start position:0% +eigenstate so what is this equal to this + + + align:start position:0% +eigenstate so what is this equal to this +is equal to a B minus B a 5e which I can + + align:start position:0% +is equal to a B minus B a 5e which I can + + + align:start position:0% +is equal to a B minus B a 5e which I can +write as a B by B minus B a 5e by + + align:start position:0% +write as a B by B minus B a 5e by + + + align:start position:0% +write as a B by B minus B a 5e by +linearity by addition really okay but be + + align:start position:0% +linearity by addition really okay but be + + + align:start position:0% +linearity by addition really okay but be +acting on Phi B gives me by hypothesis + + align:start position:0% +acting on Phi B gives me by hypothesis + + + align:start position:0% +acting on Phi B gives me by hypothesis +little B Phi V and then a acting on a + + align:start position:0% +little B Phi V and then a acting on a + + + align:start position:0% +little B Phi V and then a acting on a +constant times Phi B gives me a little a + + align:start position:0% +constant times Phi B gives me a little a + + + align:start position:0% +constant times Phi B gives me a little a +times that constant okay - now here a + + align:start position:0% +times that constant okay - now here a + + + align:start position:0% +times that constant okay - now here a +acting on Phi B gives me a little a Phi + + align:start position:0% +acting on Phi B gives me a little a Phi + + + align:start position:0% +acting on Phi B gives me a little a Phi +B and then B acting are constant times + + align:start position:0% +B and then B acting are constant times + + + align:start position:0% +B and then B acting are constant times +Phi B gives me a little B and now I can + + align:start position:0% +Phi B gives me a little B and now I can + + + align:start position:0% +Phi B gives me a little B and now I can +join these together this is equal to + + align:start position:0% +join these together this is equal to + + + align:start position:0% +join these together this is equal to +good a B little a B minus B a Phi B but + + align:start position:0% +good a B little a B minus B a Phi B but + + + align:start position:0% +good a B little a B minus B a Phi B but +little a and little B our numbers if you + + align:start position:0% +little a and little B our numbers if you + + + align:start position:0% +little a and little B our numbers if you +take seven times five and five times + + align:start position:0% +take seven times five and five times + + + align:start position:0% +take seven times five and five times +seven and you subtract them what do you + + align:start position:0% +seven and you subtract them what do you + + + align:start position:0% +seven and you subtract them what do you +get zero so in order for a and B to + + align:start position:0% +get zero so in order for a and B to + + + align:start position:0% +get zero so in order for a and B to +share a single eigenfunction phi a be + + align:start position:0% +share a single eigenfunction phi a be + + + align:start position:0% +share a single eigenfunction phi a be +what must be true of their commutator + + align:start position:0% +what must be true of their commutator + + + align:start position:0% + +it must have a nonzero kernel exactly it + + align:start position:0% +it must have a nonzero kernel exactly it + + + align:start position:0% +it must have a nonzero kernel exactly it +must the commutator must annihilate that + + align:start position:0% +must the commutator must annihilate that + + + align:start position:0% +must the commutator must annihilate that +particular function that common + + align:start position:0% +particular function that common + + + align:start position:0% +particular function that common +eigenfunction okay does it tell you that + + align:start position:0% +eigenfunction okay does it tell you that + + + align:start position:0% +eigenfunction okay does it tell you that +it kills every eigenfunction no but it + + align:start position:0% +it kills every eigenfunction no but it + + + align:start position:0% +it kills every eigenfunction no but it +must at the very least annihilate the + + align:start position:0% +must at the very least annihilate the + + + align:start position:0% +must at the very least annihilate the +shared eigenfunction true consider two + + align:start position:0% +shared eigenfunction true consider two + + + align:start position:0% +shared eigenfunction true consider two +operators of the following form consider + + align:start position:0% +operators of the following form consider + + + align:start position:0% +operators of the following form consider +two operators who commutator a b is + + align:start position:0% +two operators who commutator a b is + + + align:start position:0% +two operators who commutator a b is +equal to the identity times a constant + + align:start position:0% + + + + align:start position:0% + +okay do these operators share any common + + align:start position:0% +okay do these operators share any common + + + align:start position:0% +okay do these operators share any common +eigenfunctions they can't because the + + align:start position:0% +eigenfunctions they can't because the + + + align:start position:0% +eigenfunctions they can't because the +commutator the identity doesn't + + align:start position:0% +commutator the identity doesn't + + + align:start position:0% +commutator the identity doesn't +annihilate any wave functions any + + align:start position:0% +annihilate any wave functions any + + + align:start position:0% +annihilate any wave functions any +functions nothing is 0 when acted upon + + align:start position:0% +functions nothing is 0 when acted upon + + + align:start position:0% +functions nothing is 0 when acted upon +by the identity that's the definition of + + align:start position:0% +by the identity that's the definition of + + + align:start position:0% +by the identity that's the definition of +the identity right the identity takes + + align:start position:0% +the identity right the identity takes + + + align:start position:0% +the identity right the identity takes +any function gives it that function back + + align:start position:0% +any function gives it that function back + + + align:start position:0% +any function gives it that function back +cool do a and B share any common + + align:start position:0% +cool do a and B share any common + + + align:start position:0% +cool do a and B share any common +eigenfunctions now let's think about + + align:start position:0% +eigenfunctions now let's think about + + + align:start position:0% +eigenfunctions now let's think about +what that means in terms of what single + + align:start position:0% +what that means in terms of what single + + + align:start position:0% +what that means in terms of what single +with that term but what that means in + + align:start position:0% +with that term but what that means in + + + align:start position:0% +with that term but what that means in +terms of observables observables are + + align:start position:0% +terms of observables observables are + + + align:start position:0% +terms of observables observables are +represented by operators what are the + + align:start position:0% +represented by operators what are the + + + align:start position:0% +represented by operators what are the +eigen function what is the meaning of + + align:start position:0% +eigen function what is the meaning of + + + align:start position:0% +eigen function what is the meaning of +the eigenfunctions of those operators it + + align:start position:0% +the eigenfunctions of those operators it + + + align:start position:0% +the eigenfunctions of those operators it +corresponds to the state with a definite + + align:start position:0% +corresponds to the state with a definite + + + align:start position:0% +corresponds to the state with a definite +value of that observable and the value + + align:start position:0% +value of that observable and the value + + + align:start position:0% +value of that observable and the value +is the corresponding eigen function I + + align:start position:0% +is the corresponding eigen function I + + + align:start position:0% +is the corresponding eigen function I +can value yeah so the eigen function of + + align:start position:0% +can value yeah so the eigen function of + + + align:start position:0% +can value yeah so the eigen function of +an operator of an observable operator is + + align:start position:0% +an operator of an observable operator is + + + align:start position:0% +an operator of an observable operator is +a possible state with a definite value + + align:start position:0% +a possible state with a definite value + + + align:start position:0% +a possible state with a definite value +of that operator if I tell you that I + + align:start position:0% +of that operator if I tell you that I + + + align:start position:0% +of that operator if I tell you that I +have a state which is an energy + + align:start position:0% +have a state which is an energy + + + align:start position:0% +have a state which is an energy +eigenfunction then that means it is a + + align:start position:0% +eigenfunction then that means it is a + + + align:start position:0% +eigenfunction then that means it is a +state with a definite value of the + + align:start position:0% +state with a definite value of the + + + align:start position:0% +state with a definite value of the +energy if I measure that under general + + align:start position:0% +energy if I measure that under general + + + align:start position:0% +energy if I measure that under general +exactly what I will get cool if these + + align:start position:0% +exactly what I will get cool if these + + + align:start position:0% +exactly what I will get cool if these +are two observables that a and B are two + + align:start position:0% +are two observables that a and B are two + + + align:start position:0% +are two observables that a and B are two +observables and their commutator is + + align:start position:0% +observables and their commutator is + + + align:start position:0% +observables and their commutator is +proportional to the identity is it + + align:start position:0% +proportional to the identity is it + + + align:start position:0% +proportional to the identity is it +possible that there is a state with a + + align:start position:0% +possible that there is a state with a + + + align:start position:0% +possible that there is a state with a +definite value of a and a definite value + + align:start position:0% +definite value of a and a definite value + + + align:start position:0% +definite value of a and a definite value +of B simultaneously no because I stay + + align:start position:0% +of B simultaneously no because I stay + + + align:start position:0% +of B simultaneously no because I stay +with the definite value of an a would be + + align:start position:0% +with the definite value of an a would be + + + align:start position:0% +with the definite value of an a would be +an eigenfunction of a + + align:start position:0% +an eigenfunction of a + + + align:start position:0% +an eigenfunction of a +the state with the definite value of B + + align:start position:0% +the state with the definite value of B + + + align:start position:0% +the state with the definite value of B +would be a eigenfunction of B and there + + align:start position:0% +would be a eigenfunction of B and there + + + align:start position:0% +would be a eigenfunction of B and there +are no common States no common + + align:start position:0% +are no common States no common + + + align:start position:0% +are no common States no common +eigenfunctions of a and B because the + + align:start position:0% +eigenfunctions of a and B because the + + + align:start position:0% +eigenfunctions of a and B because the +commutator never kills a state and it + + align:start position:0% +commutator never kills a state and it + + + align:start position:0% +commutator never kills a state and it +has no zeros what is the commutator of X + + align:start position:0% +has no zeros what is the commutator of X + + + align:start position:0% +has no zeros what is the commutator of X +and P commit this memory IH bar now when + + align:start position:0% +and P commit this memory IH bar now when + + + align:start position:0% +and P commit this memory IH bar now when +we write a H bar this is not really an + + align:start position:0% +we write a H bar this is not really an + + + align:start position:0% +we write a H bar this is not really an +opera that's a number what's the + + align:start position:0% +opera that's a number what's the + + + align:start position:0% +opera that's a number what's the +operator the identity are there any + + align:start position:0% +operator the identity are there any + + + align:start position:0% +operator the identity are there any +states which are simultaneously + + align:start position:0% +states which are simultaneously + + + align:start position:0% +states which are simultaneously +eigenfunctions of X the operator X + + align:start position:0% +eigenfunctions of X the operator X + + + align:start position:0% +eigenfunctions of X the operator X +intimate and eigenfunctions of P are + + align:start position:0% +intimate and eigenfunctions of P are + + + align:start position:0% +intimate and eigenfunctions of P are +there any states that have a definite + + align:start position:0% +there any states that have a definite + + + align:start position:0% +there any states that have a definite +position and a definite momentum + + align:start position:0% +position and a definite momentum + + + align:start position:0% +position and a definite momentum +simultaneously is that because we're + + align:start position:0% +simultaneously is that because we're + + + align:start position:0% +simultaneously is that because we're +ignorant are we ignorant yes okay good + + align:start position:0% +ignorant are we ignorant yes okay good + + + align:start position:0% +ignorant are we ignorant yes okay good +so it is not it is because the kinds of + + align:start position:0% +so it is not it is because the kinds of + + + align:start position:0% +so it is not it is because the kinds of +things that position and momentum are + + align:start position:0% +things that position and momentum are + + + align:start position:0% +things that position and momentum are +forbid the existence of a state with a + + align:start position:0% +forbid the existence of a state with a + + + align:start position:0% +forbid the existence of a state with a +definite value of x and with a definite + + align:start position:0% +definite value of x and with a definite + + + align:start position:0% +definite value of x and with a definite +value of P simultaneously there's veter + + align:start position:0% +value of P simultaneously there's veter + + + align:start position:0% +value of P simultaneously there's veter +here and we're there nor pose nor + + align:start position:0% +here and we're there nor pose nor + + + align:start position:0% +here and we're there nor pose nor +neither okay so this tells us something + + align:start position:0% +neither okay so this tells us something + + + align:start position:0% +neither okay so this tells us something +very lovely this tells us that if we're + + align:start position:0% +very lovely this tells us that if we're + + + align:start position:0% +very lovely this tells us that if we're +in a state with a definite value of X + + align:start position:0% +in a state with a definite value of X + + + align:start position:0% +in a state with a definite value of X +what must be true of our uncertainty in + + align:start position:0% +what must be true of our uncertainty in + + + align:start position:0% +what must be true of our uncertainty in +the value of P it can't be zero + + align:start position:0% +the value of P it can't be zero + + + align:start position:0% +the value of P it can't be zero +because if it were zero for uncertainty + + align:start position:0% +because if it were zero for uncertainty + + + align:start position:0% +because if it were zero for uncertainty +in the knowledge P were zero that would + + align:start position:0% +in the knowledge P were zero that would + + + align:start position:0% +in the knowledge P were zero that would +mean we're in a P I can say we would + + align:start position:0% +mean we're in a P I can say we would + + + align:start position:0% +mean we're in a P I can say we would +have a definite value of P so if Delta X + + align:start position:0% +have a definite value of P so if Delta X + + + align:start position:0% +have a definite value of P so if Delta X +is zero Delta P cannot be zero for sure + + align:start position:0% +is zero Delta P cannot be zero for sure + + + align:start position:0% +is zero Delta P cannot be zero for sure +now how big does it have to be could it + + align:start position:0% +now how big does it have to be could it + + + align:start position:0% +now how big does it have to be could it +be arbitrarily small so here's a + + align:start position:0% +be arbitrarily small so here's a + + + align:start position:0% +be arbitrarily small so here's a +commutation relation you will prove the + + align:start position:0% +commutation relation you will prove the + + + align:start position:0% +commutation relation you will prove the +following relation later on in the + + align:start position:0% +following relation later on in the + + + align:start position:0% +following relation later on in the +course but I want to tell you now + + align:start position:0% +course but I want to tell you now + + + align:start position:0% +course but I want to tell you now +because I want to give you some + + align:start position:0% +because I want to give you some + + + align:start position:0% +because I want to give you some +intuition for what the commutator is + + align:start position:0% +intuition for what the commutator is + + + align:start position:0% +intuition for what the commutator is +what it means what the physics of it is + + align:start position:0% +what it means what the physics of it is + + + align:start position:0% +what it means what the physics of it is +if I take two operators a and B with + + align:start position:0% +if I take two operators a and B with + + + align:start position:0% +if I take two operators a and B with +which have a commutator which is a + + align:start position:0% +which have a commutator which is a + + + align:start position:0% +which have a commutator which is a +constant times the identity then the + + align:start position:0% +constant times the identity then the + + + align:start position:0% +constant times the identity then the +uncertainty in any state a sasai of a + + align:start position:0% +uncertainty in any state a sasai of a + + + align:start position:0% +uncertainty in any state a sasai of a +times the uncertainty in a States I the + + align:start position:0% +times the uncertainty in a States I the + + + align:start position:0% +times the uncertainty in a States I the +same States I of B must be greater than + + align:start position:0% +same States I of B must be greater than + + + align:start position:0% +same States I of B must be greater than +or equal to one-half + + align:start position:0% +or equal to one-half + + + align:start position:0% +or equal to one-half +the absolute value of the expectation + + align:start position:0% +the absolute value of the expectation + + + align:start position:0% +the absolute value of the expectation +value of the commutator that's an + + align:start position:0% +value of the commutator that's an + + + align:start position:0% +value of the commutator that's an +amazing set of symbols of a with B okay + + align:start position:0% + + + + align:start position:0% + +square root I gotta take a squirt thank + + align:start position:0% +square root I gotta take a squirt thank + + + align:start position:0% +square root I gotta take a squirt thank +you + + align:start position:0% +you + + + align:start position:0% +you +so the easier way through these are file + + align:start position:0% +so the easier way through these are file + + + align:start position:0% +so the easier way through these are file +let's see a B let's just make sure I'm + + align:start position:0% +let's see a B let's just make sure I'm + + + align:start position:0% +let's see a B let's just make sure I'm +getting this right + + align:start position:0% +getting this right + + + align:start position:0% +getting this right +I'm commentator of a and B it's oh no no + + align:start position:0% +I'm commentator of a and B it's oh no no + + + align:start position:0% +I'm commentator of a and B it's oh no no +there's no square root sorry why are you + + align:start position:0% +there's no square root sorry why are you + + + align:start position:0% +there's no square root sorry why are you +messing with me + + align:start position:0% + + + + align:start position:0% + +expectation value of a and B Delta a + + align:start position:0% +expectation value of a and B Delta a + + + align:start position:0% +expectation value of a and B Delta a +delta P H bar um yes good okay so in + + align:start position:0% +delta P H bar um yes good okay so in + + + align:start position:0% +delta P H bar um yes good okay so in +particular this expectation value should + + align:start position:0% +particular this expectation value should + + + align:start position:0% +particular this expectation value should +be taken with the states I sorry late + + align:start position:0% +be taken with the states I sorry late + + + align:start position:0% +be taken with the states I sorry late +and I'm tired + + align:start position:0% +and I'm tired + + + align:start position:0% +and I'm tired +sorry and this should be taken in the + + align:start position:0% +sorry and this should be taken in the + + + align:start position:0% +sorry and this should be taken in the +states I okay so we compute the + + align:start position:0% +states I okay so we compute the + + + align:start position:0% +states I okay so we compute the +commutator we take the expectation value + + align:start position:0% +commutator we take the expectation value + + + align:start position:0% +commutator we take the expectation value +in our state we take the norm multiplied + + align:start position:0% +in our state we take the norm multiplied + + + align:start position:0% +in our state we take the norm multiplied +by 1/2 and this is the bound this is the + + align:start position:0% +by 1/2 and this is the bound this is the + + + align:start position:0% +by 1/2 and this is the bound this is the +claim so let's check this in the case of + + align:start position:0% +claim so let's check this in the case of + + + align:start position:0% +claim so let's check this in the case of +X and P and we'll derive this using just + + align:start position:0% +X and P and we'll derive this using just + + + align:start position:0% +X and P and we'll derive this using just +math this will come from just linear + + align:start position:0% +math this will come from just linear + + + align:start position:0% +math this will come from just linear +algebra so let's check this in the case + + align:start position:0% +algebra so let's check this in the case + + + align:start position:0% +algebra so let's check this in the case +of X in P and X and P what's the + + align:start position:0% +of X in P and X and P what's the + + + align:start position:0% +of X in P and X and P what's the +expectation so what's the expectation + + align:start position:0% +expectation so what's the expectation + + + align:start position:0% +expectation so what's the expectation +value in a state sigh of I h-bar times + + align:start position:0% +value in a state sigh of I h-bar times + + + align:start position:0% +value in a state sigh of I h-bar times +the operator one saw its IH bar IH bar + + align:start position:0% +the operator one saw its IH bar IH bar + + + align:start position:0% +the operator one saw its IH bar IH bar +great so what happens over here what do + + align:start position:0% +great so what happens over here what do + + + align:start position:0% +great so what happens over here what do +we get for Delta X into the states I + + align:start position:0% +we get for Delta X into the states I + + + align:start position:0% +we get for Delta X into the states I +times Delta P in the state's I whoops in + + align:start position:0% +times Delta P in the state's I whoops in + + + align:start position:0% +times Delta P in the state's I whoops in +the states I P this must be greater than + + align:start position:0% +the states I P this must be greater than + + + align:start position:0% +the states I P this must be greater than +or equal to 1/2 times the act of the + + align:start position:0% +or equal to 1/2 times the act of the + + + align:start position:0% +or equal to 1/2 times the act of the +absolute value of the expectation value + + align:start position:0% +absolute value of the expectation value + + + align:start position:0% +absolute value of the expectation value +of the commutator but the expectation + + align:start position:0% +of the commutator but the expectation + + + align:start position:0% +of the commutator but the expectation +value of the commutator is IH bar and + + align:start position:0% +value of the commutator is IH bar and + + + align:start position:0% +value of the commutator is IH bar and +the norm of that is just H bar this is + + align:start position:0% +the norm of that is just H bar this is + + + align:start position:0% +the norm of that is just H bar this is +the uncertainty relation so given some + + align:start position:0% +the uncertainty relation so given some + + + align:start position:0% +the uncertainty relation so given some +uncertainty in Delta X this tells us how + + align:start position:0% +uncertainty in Delta X this tells us how + + + align:start position:0% +uncertainty in Delta X this tells us how +much Delta P is now how does this + + align:start position:0% +much Delta P is now how does this + + + align:start position:0% +much Delta P is now how does this +right-hand side depend on the weight + + align:start position:0% +right-hand side depend on the weight + + + align:start position:0% +right-hand side depend on the weight +and sigh well it turns out it doesn't + + align:start position:0% +and sigh well it turns out it doesn't + + + align:start position:0% +and sigh well it turns out it doesn't +right it's explicitly independent of the + + align:start position:0% +right it's explicitly independent of the + + + align:start position:0% +right it's explicitly independent of the +particular wavefunction we're interested + + align:start position:0% +particular wavefunction we're interested + + + align:start position:0% +particular wavefunction we're interested +in for any wave function mm-hmm + + align:start position:0% +in for any wave function mm-hmm + + + align:start position:0% +in for any wave function mm-hmm +for any wave function whatsoever the + + align:start position:0% +for any wave function whatsoever the + + + align:start position:0% +for any wave function whatsoever the +uncertainty in X times the uncertainty + + align:start position:0% +uncertainty in X times the uncertainty + + + align:start position:0% +uncertainty in X times the uncertainty +in P must be greater than or equal to + + align:start position:0% +in P must be greater than or equal to + + + align:start position:0% +in P must be greater than or equal to +1/2 H bar and this is a consequence of + + align:start position:0% +1/2 H bar and this is a consequence of + + + align:start position:0% +1/2 H bar and this is a consequence of +the commutation and more importantly the + + align:start position:0% +the commutation and more importantly the + + + align:start position:0% +the commutation and more importantly the +failure of X and P to commute because + + align:start position:0% +failure of X and P to commute because + + + align:start position:0% +failure of X and P to commute because +the ability to commute and get 0 is + + align:start position:0% +the ability to commute and get 0 is + + + align:start position:0% +the ability to commute and get 0 is +necessary for there to be common + + align:start position:0% +necessary for there to be common + + + align:start position:0% +necessary for there to be common +eigenstates now imagine in this case a + + align:start position:0% +eigenstates now imagine in this case a + + + align:start position:0% +eigenstates now imagine in this case a +and B are that a and B that in fact do + + align:start position:0% +and B are that a and B that in fact do + + + align:start position:0% +and B are that a and B that in fact do +share a common eigenstate so let's take + + align:start position:0% +share a common eigenstate so let's take + + + align:start position:0% +share a common eigenstate so let's take +compute the expectation value R the + + align:start position:0% +compute the expectation value R the + + + align:start position:0% +compute the expectation value R the +uncertainty of a in the state Phi so + + align:start position:0% +uncertainty of a in the state Phi so + + + align:start position:0% +uncertainty of a in the state Phi so +maybe by some baby + + align:start position:0% +maybe by some baby + + + align:start position:0% +maybe by some baby +Phi baby vise baby and what is this + + align:start position:0% +Phi baby vise baby and what is this + + + align:start position:0% +Phi baby vise baby and what is this +equal to well what's the commutator + + align:start position:0% +equal to well what's the commutator + + + align:start position:0% +equal to well what's the commutator +acting on the state Phi sub a B 0 so + + align:start position:0% +acting on the state Phi sub a B 0 so + + + align:start position:0% +acting on the state Phi sub a B 0 so +this is greater than or equal to 0 + + align:start position:0% +this is greater than or equal to 0 + + + align:start position:0% +this is greater than or equal to 0 +and in fact you can just check by going + + align:start position:0% +and in fact you can just check by going + + + align:start position:0% +and in fact you can just check by going +through the proof of this that is just + + align:start position:0% +through the proof of this that is just + + + align:start position:0% +through the proof of this that is just +equal to 0 so what's the uncertainty of + + align:start position:0% +equal to 0 so what's the uncertainty of + + + align:start position:0% +equal to 0 so what's the uncertainty of +a well we know it's in the state with + + align:start position:0% +a well we know it's in the state with + + + align:start position:0% +a well we know it's in the state with +definite value of a it's 0 uncertainty + + align:start position:0% +definite value of a it's 0 uncertainty + + + align:start position:0% +definite value of a it's 0 uncertainty +and B in the state what's the + + align:start position:0% +and B in the state what's the + + + align:start position:0% +and B in the state what's the +uncertainty 0 we know that it's in an + + align:start position:0% +uncertainty 0 we know that it's in an + + + align:start position:0% +uncertainty 0 we know that it's in an +eigenstate of B so 0 is indeed greater + + align:start position:0% +eigenstate of B so 0 is indeed greater + + + align:start position:0% +eigenstate of B so 0 is indeed greater +than or equal to 0 so it satisfies the + + align:start position:0% +than or equal to 0 so it satisfies the + + + align:start position:0% +than or equal to 0 so it satisfies the +uncertainty relation commuting is + + align:start position:0% +uncertainty relation commuting is + + + align:start position:0% +uncertainty relation commuting is +telling you about the possibility of the + + align:start position:0% +telling you about the possibility of the + + + align:start position:0% +telling you about the possibility of the +state having definite values of both + + align:start position:0% +state having definite values of both + + + align:start position:0% +state having definite values of both +operators simultaneously and this is + + align:start position:0% +operators simultaneously and this is + + + align:start position:0% +operators simultaneously and this is +going to turn out to be enormously + + align:start position:0% +going to turn out to be enormously + + + align:start position:0% +going to turn out to be enormously +valuable when we talk about angular + + align:start position:0% +valuable when we talk about angular + + + align:start position:0% +valuable when we talk about angular +momentum which is coming in a couple of + + align:start position:0% +momentum which is coming in a couple of + + + align:start position:0% +momentum which is coming in a couple of +weeks ok see you guys on Thursday here + + align:start position:0% +weeks ok see you guys on Thursday here + + + align:start position:0% +weeks ok see you guys on Thursday here +for the midterm + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/WaCXmcVVduI.txt b/WaCXmcVVduI.txt new file mode 100644 index 0000000000000000000000000000000000000000..de9d42f122391fec5026b60c3e1fcc0f0c8bd673 --- /dev/null +++ b/WaCXmcVVduI.txt @@ -0,0 +1,4507 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu uh chemical properties so + + align:start position:0% +ocw.mit.edu uh chemical properties so + + + align:start position:0% +ocw.mit.edu uh chemical properties so +let's uh let's put something up as a + + align:start position:0% +let's uh let's put something up as a + + + align:start position:0% +let's uh let's put something up as a +hypothesis let's say well uh maybe it + + align:start position:0% +hypothesis let's say well uh maybe it + + + align:start position:0% +hypothesis let's say well uh maybe it +has to do with the + + align:start position:0% + + + + align:start position:0% + +energy that it takes to remove electrons + + align:start position:0% +energy that it takes to remove electrons + + + align:start position:0% +energy that it takes to remove electrons +and note one other thing that I + + align:start position:0% +and note one other thing that I + + + align:start position:0% +and note one other thing that I +uh failed to point out if you take a + + align:start position:0% +uh failed to point out if you take a + + + align:start position:0% +uh failed to point out if you take a +look at the energies associated with the + + align:start position:0% +look at the energies associated with the + + + align:start position:0% +look at the energies associated with the +outermost electrons in this case lithium + + align:start position:0% +outermost electrons in this case lithium + + + align:start position:0% +outermost electrons in this case lithium +you see it's um .5 megga per mole and + + align:start position:0% +you see it's um .5 megga per mole and + + + align:start position:0% +you see it's um .5 megga per mole and +then what's the 6.26 that's associated + + align:start position:0% +then what's the 6.26 that's associated + + + align:start position:0% +then what's the 6.26 that's associated +with one n equals 1 inner shell there's + + align:start position:0% +with one n equals 1 inner shell there's + + + align:start position:0% +with one n equals 1 inner shell there's +a huge difference between the energies + + align:start position:0% +a huge difference between the energies + + + align:start position:0% +a huge difference between the energies +and the outermost shell shell and the + + align:start position:0% +and the outermost shell shell and the + + + align:start position:0% +and the outermost shell shell and the +inner shells which tells you that it's + + align:start position:0% +inner shells which tells you that it's + + + align:start position:0% +inner shells which tells you that it's +unlikely that any electrons except those + + align:start position:0% +unlikely that any electrons except those + + + align:start position:0% +unlikely that any electrons except those +in the outermost shell are going to be + + align:start position:0% +in the outermost shell are going to be + + + align:start position:0% +in the outermost shell are going to be +active the inner electrons are so + + align:start position:0% +active the inner electrons are so + + + align:start position:0% +active the inner electrons are so +tightly bound that they're for + + align:start position:0% +tightly bound that they're for + + + align:start position:0% +tightly bound that they're for +all intents and purposes immobilized + + align:start position:0% +all intents and purposes immobilized + + + align:start position:0% +all intents and purposes immobilized +when it comes to reactivity again Boron + + align:start position:0% +when it comes to reactivity again Boron + + + align:start position:0% +when it comes to reactivity again Boron +is a good example look 8 1.36 this is 2p + + align:start position:0% +is a good example look 8 1.36 this is 2p + + + align:start position:0% +is a good example look 8 1.36 this is 2p +this is 2s yeah they're different but + + align:start position:0% +this is 2s yeah they're different but + + + align:start position:0% +this is 2s yeah they're different but +they're roughly on the order of about 1 + + align:start position:0% +they're roughly on the order of about 1 + + + align:start position:0% +they're roughly on the order of about 1 +megga per mole if you go down to 1s it's + + align:start position:0% +megga per mole if you go down to 1s it's + + + align:start position:0% +megga per mole if you go down to 1s it's +20 Mega per mole so the chances of + + align:start position:0% +20 Mega per mole so the chances of + + + align:start position:0% +20 Mega per mole so the chances of +getting any activity from these inner + + align:start position:0% +getting any activity from these inner + + + align:start position:0% +getting any activity from these inner +shell electrons are vanishingly small so + + align:start position:0% +shell electrons are vanishingly small so + + + align:start position:0% +shell electrons are vanishingly small so +let's focus on the outer shell electrons + + align:start position:0% +let's focus on the outer shell electrons + + + align:start position:0% +let's focus on the outer shell electrons +and these outer shell electrons are + + align:start position:0% +and these outer shell electrons are + + + align:start position:0% +and these outer shell electrons are +termed veence electrons so let's + + align:start position:0% +termed veence electrons so let's + + + align:start position:0% +termed veence electrons so let's +construct let's construct a uh a model + + align:start position:0% +construct let's construct a uh a model + + + align:start position:0% +construct let's construct a uh a model +here that suggests that chemical + + align:start position:0% +here that suggests that chemical + + + align:start position:0% +here that suggests that chemical +reactivity is somehow related + + align:start position:0% +reactivity is somehow related + + + align:start position:0% +reactivity is somehow related +to chemical + + align:start position:0% +to chemical + + + align:start position:0% +to chemical +reactivity is somehow related to the + + align:start position:0% +reactivity is somehow related to the + + + align:start position:0% +reactivity is somehow related to the +electron binding energies electron + + align:start position:0% +electron binding energies electron + + + align:start position:0% +electron binding energies electron +binding + + align:start position:0% +binding + + + align:start position:0% +binding +energies of the outermost + + align:start position:0% +energies of the outermost + + + align:start position:0% +energies of the outermost +electrons of the outermost + + align:start position:0% +electrons of the outermost + + + align:start position:0% +electrons of the outermost +shell and this outermost shell is termed + + align:start position:0% +shell and this outermost shell is termed + + + align:start position:0% +shell and this outermost shell is termed +the + + align:start position:0% +the + + + align:start position:0% +the +veence the veence shell so in a first + + align:start position:0% +veence the veence shell so in a first + + + align:start position:0% +veence the veence shell so in a first +blush you might say well why don't we + + align:start position:0% +blush you might say well why don't we + + + align:start position:0% +blush you might say well why don't we +just take the first ionization energy + + align:start position:0% +just take the first ionization energy + + + align:start position:0% +just take the first ionization energy +and that's not a bad first guess but we + + align:start position:0% +and that's not a bad first guess but we + + + align:start position:0% +and that's not a bad first guess but we +know for example that magnesium when it + + align:start position:0% +know for example that magnesium when it + + + align:start position:0% +know for example that magnesium when it +reacts it reacts with both of its + + align:start position:0% +reacts it reacts with both of its + + + align:start position:0% +reacts it reacts with both of its +electrons not just one of its electrons + + align:start position:0% +electrons not just one of its electrons + + + align:start position:0% +electrons not just one of its electrons +so taking just the outermost electron + + align:start position:0% +so taking just the outermost electron + + + align:start position:0% +so taking just the outermost electron +might give us um some false reading so + + align:start position:0% +might give us um some false reading so + + + align:start position:0% +might give us um some false reading so +what if we capture all of the veence + + align:start position:0% +what if we capture all of the veence + + + align:start position:0% +what if we capture all of the veence +electrons is there some way of of + + align:start position:0% +electrons is there some way of of + + + align:start position:0% +electrons is there some way of of +handling that because that'll take care + + align:start position:0% +handling that because that'll take care + + + align:start position:0% +handling that because that'll take care +of all of the electrons that are capable + + align:start position:0% +of all of the electrons that are capable + + + align:start position:0% +of all of the electrons that are capable +of reacting none of the inner shell + + align:start position:0% +of reacting none of the inner shell + + + align:start position:0% +of reacting none of the inner shell +electrons and we do so by a + + align:start position:0% +electrons and we do so by a + + + align:start position:0% +electrons and we do so by a +uh a quantity called the + + align:start position:0% +uh a quantity called the + + + align:start position:0% +uh a quantity called the +average veence electron energy it's in + + align:start position:0% +average veence electron energy it's in + + + align:start position:0% +average veence electron energy it's in +other words it's the average energy of + + align:start position:0% +other words it's the average energy of + + + align:start position:0% +other words it's the average energy of +all the veence + + align:start position:0% +all the veence + + + align:start position:0% +all the veence +electrons so let's take a look at a an + + align:start position:0% +electrons so let's take a look at a an + + + align:start position:0% +electrons so let's take a look at a an +example an example of that might be um + + align:start position:0% +example an example of that might be um + + + align:start position:0% +example an example of that might be um +oh let's look at something + + align:start position:0% +oh let's look at something + + + align:start position:0% +oh let's look at something +like oxygen if you look at oxygen oxygen + + align:start position:0% +like oxygen if you look at oxygen oxygen + + + align:start position:0% +like oxygen if you look at oxygen oxygen +is 1 S2 which is an inshell electron I'm + + align:start position:0% +is 1 S2 which is an inshell electron I'm + + + align:start position:0% +is 1 S2 which is an inshell electron I'm +just putting it up for completeness 2s2 + + align:start position:0% +just putting it up for completeness 2s2 + + + align:start position:0% +just putting it up for completeness 2s2 +and 2 + + align:start position:0% +and 2 + + + align:start position:0% +and 2 +P4 and um so here's the veent shell if I + + align:start position:0% +P4 and um so here's the veent shell if I + + + align:start position:0% +P4 and um so here's the veent shell if I +want to take the average energy of all + + align:start position:0% +want to take the average energy of all + + + align:start position:0% +want to take the average energy of all +of those what I can do is go over to my + + align:start position:0% +of those what I can do is go over to my + + + align:start position:0% +of those what I can do is go over to my +data set here's a data set there's + + align:start position:0% +data set here's a data set there's + + + align:start position:0% +data set here's a data set there's +oxygen the 2p is 1.31 the 2s is + + align:start position:0% +oxygen the 2p is 1.31 the 2s is + + + align:start position:0% +oxygen the 2p is 1.31 the 2s is +3.12 so then I could say that the + + align:start position:0% +3.12 so then I could say that the + + + align:start position:0% +3.12 so then I could say that the +average veence electron energy for + + align:start position:0% +average veence electron energy for + + + align:start position:0% +average veence electron energy for +oxygen would then be I've got two uh s + + align:start position:0% +oxygen would then be I've got two uh s + + + align:start position:0% +oxygen would then be I've got two uh s +electrons so it's 2 * + + align:start position:0% +electrons so it's 2 * + + + align:start position:0% +electrons so it's 2 * +3.12 plus 4 * + + align:start position:0% +3.12 plus 4 * + + + align:start position:0% +3.12 plus 4 * +what is it uh + + align:start position:0% +what is it uh + + + align:start position:0% +what is it uh +1.31 all divided by six I'm averaging it + + align:start position:0% +1.31 all divided by six I'm averaging it + + + align:start position:0% +1.31 all divided by six I'm averaging it +over the entire set of valence electrons + + align:start position:0% +over the entire set of valence electrons + + + align:start position:0% +over the entire set of valence electrons +which gives me + + align:start position:0% +which gives me + + + align:start position:0% +which gives me +1.91 megga per mole or uh in my favorite + + align:start position:0% +1.91 megga per mole or uh in my favorite + + + align:start position:0% +1.91 megga per mole or uh in my favorite +unit 19.8 electron volts this is + + align:start position:0% +unit 19.8 electron volts this is + + + align:start position:0% +unit 19.8 electron volts this is +electron volts per per + + align:start position:0% +electron volts per per + + + align:start position:0% +electron volts per per +atom so how does average veence electron + + align:start position:0% +atom so how does average veence electron + + + align:start position:0% +atom so how does average veence electron +energy uh vary across the periodic table + + align:start position:0% +energy uh vary across the periodic table + + + align:start position:0% +energy uh vary across the periodic table +let's take a look at + + align:start position:0% + + + + align:start position:0% + +that so we see it here we see that it + + align:start position:0% +that so we see it here we see that it + + + align:start position:0% +that so we see it here we see that it +varies uh monotonically from left to + + align:start position:0% +varies uh monotonically from left to + + + align:start position:0% +varies uh monotonically from left to +right as we move along a row so this is + + align:start position:0% +right as we move along a row so this is + + + align:start position:0% +right as we move along a row so this is +a constant n number within a constant + + align:start position:0% +a constant n number within a constant + + + align:start position:0% +a constant n number within a constant +shell it varies from left to right + + align:start position:0% +shell it varies from left to right + + + align:start position:0% +shell it varies from left to right +maximally uh taking value at the right + + align:start position:0% +maximally uh taking value at the right + + + align:start position:0% +maximally uh taking value at the right +extreme and within a column it decreases + + align:start position:0% +extreme and within a column it decreases + + + align:start position:0% +extreme and within a column it decreases +down a column it rises up a row it + + align:start position:0% +down a column it rises up a row it + + + align:start position:0% +down a column it rises up a row it +decreases down a + + align:start position:0% +decreases down a + + + align:start position:0% +decreases down a +column and the values that it takes uh + + align:start position:0% +column and the values that it takes uh + + + align:start position:0% +column and the values that it takes uh +can be broken into three groups over + + align:start position:0% +can be broken into three groups over + + + align:start position:0% +can be broken into three groups over +here in the uh in the lower left corner + + align:start position:0% +here in the uh in the lower left corner + + + align:start position:0% +here in the uh in the lower left corner +we have elements that as a group have + + align:start position:0% +we have elements that as a group have + + + align:start position:0% +we have elements that as a group have +very low values of average veence + + align:start position:0% +very low values of average veence + + + align:start position:0% +very low values of average veence +electron energy these are elements + + align:start position:0% +electron energy these are elements + + + align:start position:0% +electron energy these are elements +that are good electron donors they're + + align:start position:0% +that are good electron donors they're + + + align:start position:0% +that are good electron donors they're +good electron donors because the + + align:start position:0% +good electron donors because the + + + align:start position:0% +good electron donors because the +electrons aren't tightly baled + + align:start position:0% +electrons aren't tightly baled + + + align:start position:0% +electrons aren't tightly baled +okay elements with low average valence + + align:start position:0% +okay elements with low average valence + + + align:start position:0% +okay elements with low average valence +electron energy and here I'm + + align:start position:0% +electron energy and here I'm + + + align:start position:0% +electron energy and here I'm +saying below 11 electron volts these are + + align:start position:0% +saying below 11 electron volts these are + + + align:start position:0% +saying below 11 electron volts these are +good electron + + align:start position:0% +good electron + + + align:start position:0% +good electron +donors good electron donors and we call + + align:start position:0% +donors good electron donors and we call + + + align:start position:0% +donors good electron donors and we call +these in simple English Metals these are + + align:start position:0% +these in simple English Metals these are + + + align:start position:0% +these in simple English Metals these are +metals and it turns out that about 75% + + align:start position:0% +metals and it turns out that about 75% + + + align:start position:0% +metals and it turns out that about 75% +of the periodic table 75% of the + + align:start position:0% +of the periodic table 75% of the + + + align:start position:0% +of the periodic table 75% of the +periodic table falls into this C + + align:start position:0% +periodic table falls into this C + + + align:start position:0% +periodic table falls into this C +category so the vast majority of + + align:start position:0% +category so the vast majority of + + + align:start position:0% +category so the vast majority of +elements on the periodic table are uh + + align:start position:0% +elements on the periodic table are uh + + + align:start position:0% +elements on the periodic table are uh +metals and at The Other Extreme we have + + align:start position:0% +metals and at The Other Extreme we have + + + align:start position:0% +metals and at The Other Extreme we have +elements with very high + + align:start position:0% +elements with very high + + + align:start position:0% +elements with very high +value elements with high average veence + + align:start position:0% +value elements with high average veence + + + align:start position:0% +value elements with high average veence +electron + + align:start position:0% +electron + + + align:start position:0% +electron +energy we just did the calculation for + + align:start position:0% +energy we just did the calculation for + + + align:start position:0% +energy we just did the calculation for +oxygen this almost 20 EV High average + + align:start position:0% +oxygen this almost 20 EV High average + + + align:start position:0% +oxygen this almost 20 EV High average +veence electron energy greater than 13 + + align:start position:0% +veence electron energy greater than 13 + + + align:start position:0% +veence electron energy greater than 13 +electron volts so that means the + + align:start position:0% +electron volts so that means the + + + align:start position:0% +electron volts so that means the +electrons are tightly bound so these are + + align:start position:0% +electrons are tightly bound so these are + + + align:start position:0% +electrons are tightly bound so these are +poor electron donors and in fact if any + + align:start position:0% +poor electron donors and in fact if any + + + align:start position:0% +poor electron donors and in fact if any +electron comes in their midst they'll + + align:start position:0% +electron comes in their midst they'll + + + align:start position:0% +electron comes in their midst they'll +capture it because the binding energy is + + align:start position:0% +capture it because the binding energy is + + + align:start position:0% +capture it because the binding energy is +so high so these are + + align:start position:0% +so high so these are + + + align:start position:0% +so high so these are +poor electron donors but also good + + align:start position:0% +poor electron donors but also good + + + align:start position:0% +poor electron donors but also good +electron + + align:start position:0% +electron + + + align:start position:0% +electron +acceptors + + align:start position:0% +acceptors + + + align:start position:0% +acceptors +good electronic + + align:start position:0% +good electronic + + + align:start position:0% +good electronic +acceptors and we call these + + align:start position:0% + + + + align:start position:0% + +non-metals and you see those and then + + align:start position:0% +non-metals and you see those and then + + + align:start position:0% +non-metals and you see those and then +there's this group of about a half a + + align:start position:0% +there's this group of about a half a + + + align:start position:0% +there's this group of about a half a +dozen right down the diagonal middle and + + align:start position:0% +dozen right down the diagonal middle and + + + align:start position:0% +dozen right down the diagonal middle and +they have intermediate values so when + + align:start position:0% +they have intermediate values so when + + + align:start position:0% +they have intermediate values so when +the when the value of the average veence + + align:start position:0% +the when the value of the average veence + + + align:start position:0% +the when the value of the average veence +electron energy lies + + align:start position:0% +electron energy lies + + + align:start position:0% +electron energy lies +between 11 EV and 13 EV we have these + + align:start position:0% +between 11 EV and 13 EV we have these + + + align:start position:0% +between 11 EV and 13 EV we have these +elements that are neither fish or foul + + align:start position:0% +elements that are neither fish or foul + + + align:start position:0% +elements that are neither fish or foul +and you'll see a a little bit they're uh + + align:start position:0% +and you'll see a a little bit they're uh + + + align:start position:0% +and you'll see a a little bit they're uh +unique uh electrical properties and + + align:start position:0% +unique uh electrical properties and + + + align:start position:0% +unique uh electrical properties and +these are called semi + + align:start position:0% +these are called semi + + + align:start position:0% +these are called semi +Metals semi metals or + + align:start position:0% +Metals semi metals or + + + align:start position:0% +Metals semi metals or +metalloids and in some instan es they + + align:start position:0% +metalloids and in some instan es they + + + align:start position:0% +metalloids and in some instan es they +can be made to behave more nearly + + align:start position:0% +can be made to behave more nearly + + + align:start position:0% +can be made to behave more nearly +metallic and in other cases they behave + + align:start position:0% +metallic and in other cases they behave + + + align:start position:0% +metallic and in other cases they behave +more nearly uh as + + align:start position:0% +more nearly uh as + + + align:start position:0% +more nearly uh as +insulators so now with this framework I + + align:start position:0% +insulators so now with this framework I + + + align:start position:0% +insulators so now with this framework I +said that talking about these veence + + align:start position:0% +said that talking about these veence + + + align:start position:0% +said that talking about these veence +electrons might give us some insight + + align:start position:0% +electrons might give us some insight + + + align:start position:0% +electrons might give us some insight +into uh chemical reactivity what can we + + align:start position:0% +into uh chemical reactivity what can we + + + align:start position:0% +into uh chemical reactivity what can we +say about chemical reactivity well um + + align:start position:0% +say about chemical reactivity well um + + + align:start position:0% +say about chemical reactivity well um +what do we know about extremes of + + align:start position:0% +what do we know about extremes of + + + align:start position:0% +what do we know about extremes of +chemical reactivity see if we can grab + + align:start position:0% +chemical reactivity see if we can grab + + + align:start position:0% +chemical reactivity see if we can grab +on to something we know that um at one + + align:start position:0% +on to something we know that um at one + + + align:start position:0% +on to something we know that um at one +extreme we have no chemical reactivity + + align:start position:0% +extreme we have no chemical reactivity + + + align:start position:0% +extreme we have no chemical reactivity +we have elements that are totally inert + + align:start position:0% +we have elements that are totally inert + + + align:start position:0% +we have elements that are totally inert +and we have examples of this the noble + + align:start position:0% +and we have examples of this the noble + + + align:start position:0% +and we have examples of this the noble +gases dominantly inert once I know + + align:start position:0% +gases dominantly inert once I know + + + align:start position:0% +gases dominantly inert once I know +there's it's possible to induce chemical + + align:start position:0% +there's it's possible to induce chemical + + + align:start position:0% +there's it's possible to induce chemical +reactions but these are exceptions this + + align:start position:0% +reactions but these are exceptions this + + + align:start position:0% +reactions but these are exceptions this +is not the norm so we have inertness and + + align:start position:0% +is not the norm so we have inertness and + + + align:start position:0% +is not the norm so we have inertness and +at the other end we have + + align:start position:0% +at the other end we have + + + align:start position:0% +at the other end we have +explosive explosive reaction okay so do + + align:start position:0% +explosive explosive reaction okay so do + + + align:start position:0% +explosive explosive reaction okay so do +we know anything so far that we can p + + align:start position:0% +we know anything so far that we can p + + + align:start position:0% +we know anything so far that we can p +point to that would give us uh a + + align:start position:0% +point to that would give us uh a + + + align:start position:0% +point to that would give us uh a +departure and the answer is yes we know + + align:start position:0% +departure and the answer is yes we know + + + align:start position:0% +departure and the answer is yes we know +something about the noble gases we know + + align:start position:0% +something about the noble gases we know + + + align:start position:0% +something about the noble gases we know +something about the noble gases what do + + align:start position:0% +something about the noble gases what do + + + align:start position:0% +something about the noble gases what do +we know about the noble gases they're + + align:start position:0% +we know about the noble gases they're + + + align:start position:0% +we know about the noble gases they're +chemically inert they have the highest + + align:start position:0% +chemically inert they have the highest + + + align:start position:0% +chemically inert they have the highest +values they have the highest average + + align:start position:0% +values they have the highest average + + + align:start position:0% +values they have the highest average +veence electron energy in any + + align:start position:0% +veence electron energy in any + + + align:start position:0% +veence electron energy in any +shell and the electron configuration is + + align:start position:0% +shell and the electron configuration is + + + align:start position:0% +shell and the electron configuration is +always n + + align:start position:0% +always n + + + align:start position:0% +always n +S2 + + align:start position:0% +S2 + + + align:start position:0% +S2 +P6 whatever the N number is with the + + align:start position:0% +P6 whatever the N number is with the + + + align:start position:0% +P6 whatever the N number is with the +exception of helium helium is the Oddity + + align:start position:0% +exception of helium helium is the Oddity + + + align:start position:0% +exception of helium helium is the Oddity +because there's only two uh elements in + + align:start position:0% +because there's only two uh elements in + + + align:start position:0% +because there's only two uh elements in +n equals one shell but once you get + + align:start position:0% +n equals one shell but once you get + + + align:start position:0% +n equals one shell but once you get +Beyond n equals 1 it's always 2 S2 2 P6 + + align:start position:0% +Beyond n equals 1 it's always 2 S2 2 P6 + + + align:start position:0% +Beyond n equals 1 it's always 2 S2 2 P6 +3 S2 3 P6 so we have an octet an octet + + align:start position:0% +3 S2 3 P6 so we have an octet an octet + + + align:start position:0% +3 S2 3 P6 so we have an octet an octet +of electrons that seems to be associated + + align:start position:0% +of electrons that seems to be associated + + + align:start position:0% +of electrons that seems to be associated +with chemical + + align:start position:0% +with chemical + + + align:start position:0% +with chemical +inertness + + align:start position:0% +inertness + + + align:start position:0% +inertness +octet stability is the term applied to + + align:start position:0% +octet stability is the term applied to + + + align:start position:0% +octet stability is the term applied to +this feature so all right so let's go + + align:start position:0% +this feature so all right so let's go + + + align:start position:0% +this feature so all right so let's go +with this let's say well um suppose + + align:start position:0% +with this let's say well um suppose + + + align:start position:0% +with this let's say well um suppose +we hypothesize that an octet of + + align:start position:0% +we hypothesize that an octet of + + + align:start position:0% +we hypothesize that an octet of +electrons is going to lead to stability + + align:start position:0% +electrons is going to lead to stability + + + align:start position:0% +electrons is going to lead to stability +is is there someplace we can go next + + align:start position:0% +is is there someplace we can go next + + + align:start position:0% +is is there someplace we can go next +with this and I say well let's look at + + align:start position:0% +with this and I say well let's look at + + + align:start position:0% +with this and I say well let's look at +something like sodium let's look at + + align:start position:0% +something like sodium let's look at + + + align:start position:0% +something like sodium let's look at +sodium sodium has the electronic + + align:start position:0% +sodium sodium has the electronic + + + align:start position:0% +sodium sodium has the electronic +structure 1 S2 uh 2 S2 2 P6 3 S1 now + + align:start position:0% +structure 1 S2 uh 2 S2 2 P6 3 S1 now + + + align:start position:0% +structure 1 S2 uh 2 S2 2 P6 3 S1 now +that's not an Octan set but it's not + + align:start position:0% +that's not an Octan set but it's not + + + align:start position:0% +that's not an Octan set but it's not +far this is the electronic structure of + + align:start position:0% +far this is the electronic structure of + + + align:start position:0% +far this is the electronic structure of +neon so it's really sodium you can think + + align:start position:0% +neon so it's really sodium you can think + + + align:start position:0% +neon so it's really sodium you can think +of electronically as neon plus the 3s1 + + align:start position:0% +of electronically as neon plus the 3s1 + + + align:start position:0% +of electronically as neon plus the 3s1 +electron it's so close and I also know + + align:start position:0% +electron it's so close and I also know + + + align:start position:0% +electron it's so close and I also know +something else about sodium it's got a + + align:start position:0% +something else about sodium it's got a + + + align:start position:0% +something else about sodium it's got a +very low average veence electron energy + + align:start position:0% +very low average veence electron energy + + + align:start position:0% +very low average veence electron energy +its average veence electron energy is + + align:start position:0% +its average veence electron energy is + + + align:start position:0% +its average veence electron energy is +5.2 electron volts which is a heck of a + + align:start position:0% +5.2 electron volts which is a heck of a + + + align:start position:0% +5.2 electron volts which is a heck of a +lot less than 11 so this is a good metal + + align:start position:0% +lot less than 11 so this is a good metal + + + align:start position:0% +lot less than 11 so this is a good metal +it's a good electron + + align:start position:0% +it's a good electron + + + align:start position:0% +it's a good electron +donor Okay so so I've got something + + align:start position:0% +donor Okay so so I've got something + + + align:start position:0% +donor Okay so so I've got something +that's one electron away from the + + align:start position:0% +that's one electron away from the + + + align:start position:0% +that's one electron away from the +electronic structure of neon it's a good + + align:start position:0% +electronic structure of neon it's a good + + + align:start position:0% +electronic structure of neon it's a good +electron donor if it could only ditch + + align:start position:0% +electron donor if it could only ditch + + + align:start position:0% +electron donor if it could only ditch +this + + align:start position:0% +this + + + align:start position:0% +this +electron it could have the same + + align:start position:0% +electron it could have the same + + + align:start position:0% +electron it could have the same +electronic structure as neon but you + + align:start position:0% +electronic structure as neon but you + + + align:start position:0% +electronic structure as neon but you +can't just ditch an electron charge + + align:start position:0% +can't just ditch an electron charge + + + align:start position:0% +can't just ditch an electron charge +neutrality won't allow for it if you + + align:start position:0% +neutrality won't allow for it if you + + + align:start position:0% +neutrality won't allow for it if you +want to lose an electron you have to + + align:start position:0% +want to lose an electron you have to + + + align:start position:0% +want to lose an electron you have to +find some place for that electron to go + + align:start position:0% +find some place for that electron to go + + + align:start position:0% +find some place for that electron to go +another words for an electron donor to + + align:start position:0% +another words for an electron donor to + + + align:start position:0% +another words for an electron donor to +give up its electron the electron donor + + align:start position:0% +give up its electron the electron donor + + + align:start position:0% +give up its electron the electron donor +needs to have an electron sceptor so + + align:start position:0% +needs to have an electron sceptor so + + + align:start position:0% +needs to have an electron sceptor so +that's sort of half the story now let's + + align:start position:0% +that's sort of half the story now let's + + + align:start position:0% +that's sort of half the story now let's +go over to the other side let's look at + + align:start position:0% +go over to the other side let's look at + + + align:start position:0% +go over to the other side let's look at +chlorine chlorine is S2 2 S2 2 + + align:start position:0% +chlorine chlorine is S2 2 S2 2 + + + align:start position:0% +chlorine chlorine is S2 2 S2 2 +P6 3 S2 3 + + align:start position:0% +P6 3 S2 3 + + + align:start position:0% +P6 3 S2 3 +P5 and + + align:start position:0% +P5 and + + + align:start position:0% +P5 and +chlorine it's uh it's not an octet here + + align:start position:0% +chlorine it's uh it's not an octet here + + + align:start position:0% +chlorine it's uh it's not an octet here +this is 5 + 2 is seven but when I went + + align:start position:0% +this is 5 + 2 is seven but when I went + + + align:start position:0% +this is 5 + 2 is seven but when I went +to school seven was only one less than + + align:start position:0% +to school seven was only one less than + + + align:start position:0% +to school seven was only one less than +eight so this needs only one more + + align:start position:0% +eight so this needs only one more + + + align:start position:0% +eight so this needs only one more +electron if it could gain one more + + align:start position:0% +electron if it could gain one more + + + align:start position:0% +electron if it could gain one more +electron then chlorine would be ISO + + align:start position:0% +electron then chlorine would be ISO + + + align:start position:0% +electron then chlorine would be ISO +electronic with argon so it would + + align:start position:0% +electronic with argon so it would + + + align:start position:0% +electronic with argon so it would +achieve octet + + align:start position:0% +achieve octet + + + align:start position:0% +achieve octet +stability and we know that chlorine is + + align:start position:0% +stability and we know that chlorine is + + + align:start position:0% +stability and we know that chlorine is +very aggressive when it comes to + + align:start position:0% +very aggressive when it comes to + + + align:start position:0% +very aggressive when it comes to +electrons it's got an average veence + + align:start position:0% +electrons it's got an average veence + + + align:start position:0% +electrons it's got an average veence +electron energy of about 16 + + align:start position:0% +electron energy of about 16 + + + align:start position:0% +electron energy of about 16 +EV 16.5 EV which is a lot greater than + + align:start position:0% +EV 16.5 EV which is a lot greater than + + + align:start position:0% +EV 16.5 EV which is a lot greater than +11 so what if we were to put the two of + + align:start position:0% +11 so what if we were to put the two of + + + align:start position:0% +11 so what if we were to put the two of +these in the same room you've got an + + align:start position:0% +these in the same room you've got an + + + align:start position:0% +these in the same room you've got an +electron donor with a powerful urge to + + align:start position:0% +electron donor with a powerful urge to + + + align:start position:0% +electron donor with a powerful urge to +become neon likee you got an electronic + + align:start position:0% +become neon likee you got an electronic + + + align:start position:0% +become neon likee you got an electronic +sepor with a powerful urge to become + + align:start position:0% +sepor with a powerful urge to become + + + align:start position:0% +sepor with a powerful urge to become +argon likee what if we were to take this + + align:start position:0% +argon likee what if we were to take this + + + align:start position:0% +argon likee what if we were to take this +electron and send it over to + + align:start position:0% +electron and send it over to + + + align:start position:0% +electron and send it over to +here in other words engage in electron + + align:start position:0% +here in other words engage in electron + + + align:start position:0% +here in other words engage in electron +transfer electron transfer what would we + + align:start position:0% +transfer electron transfer what would we + + + align:start position:0% +transfer electron transfer what would we +achieve sodium would become sodium plus + + align:start position:0% +achieve sodium would become sodium plus + + + align:start position:0% +achieve sodium would become sodium plus +chlorine would become chlorine + + align:start position:0% +chlorine would become chlorine + + + align:start position:0% +chlorine would become chlorine +minus so I've got ion pair formation + + align:start position:0% + + + + align:start position:0% + +and I've got a huge decrease in + + align:start position:0% + + + + align:start position:0% + +energy because a donor is able to + + align:start position:0% +energy because a donor is able to + + + align:start position:0% +energy because a donor is able to +express that urge an acceptor is able to + + align:start position:0% +express that urge an acceptor is able to + + + align:start position:0% +express that urge an acceptor is able to +express that urge and I've achieved + + align:start position:0% +express that urge and I've achieved + + + align:start position:0% +express that urge and I've achieved +octet stability in a new way but there's + + align:start position:0% +octet stability in a new way but there's + + + align:start position:0% +octet stability in a new way but there's +more because now I've got pluses and + + align:start position:0% +more because now I've got pluses and + + + align:start position:0% +more because now I've got pluses and +minuses this is all gas phase all right + + align:start position:0% +minuses this is all gas phase all right + + + align:start position:0% +minuses this is all gas phase all right +it's all gas phase so what happens if I + + align:start position:0% +it's all gas phase so what happens if I + + + align:start position:0% +it's all gas phase so what happens if I +put pluses and minuses in a gas phase + + align:start position:0% +put pluses and minuses in a gas phase + + + align:start position:0% +put pluses and minuses in a gas phase +face there's a colic force of attraction + + align:start position:0% +face there's a colic force of attraction + + + align:start position:0% +face there's a colic force of attraction +there's a colic force of attraction so + + align:start position:0% +there's a colic force of attraction so + + + align:start position:0% +there's a colic force of attraction so +the + + align:start position:0% +the + + + align:start position:0% +the +sodium over here and the chlorine over + + align:start position:0% +sodium over here and the chlorine over + + + align:start position:0% +sodium over here and the chlorine over +here they'll be attracted to one + + align:start position:0% + + + + align:start position:0% + +another so let's start so + + align:start position:0% +another so let's start so + + + align:start position:0% +another so let's start so +sodium chlorine + + align:start position:0% +sodium chlorine + + + align:start position:0% +sodium chlorine +attaches um but there's more sodiums + + align:start position:0% +attaches um but there's more sodiums + + + align:start position:0% +attaches um but there's more sodiums +there's more chlorine so maybe another + + align:start position:0% +there's more chlorine so maybe another + + + align:start position:0% +there's more chlorine so maybe another +sodium will + + align:start position:0% +sodium will + + + align:start position:0% +sodium will +attach maybe another chlorine will + + align:start position:0% +attach maybe another chlorine will + + + align:start position:0% +attach maybe another chlorine will +attach and then this will go on and on + + align:start position:0% +attach and then this will go on and on + + + align:start position:0% +attach and then this will go on and on +and on without limit so what's the + + align:start position:0% +and on without limit so what's the + + + align:start position:0% +and on without limit so what's the +consequence of forming these gas ions + + align:start position:0% +consequence of forming these gas ions + + + align:start position:0% +consequence of forming these gas ions +these gas ions if you take gas + + align:start position:0% +these gas ions if you take gas + + + align:start position:0% +these gas ions if you take gas +ions gas ions of opposite + + align:start position:0% +ions gas ions of opposite + + + align:start position:0% +ions gas ions of opposite +charge will + + align:start position:0% +charge will + + + align:start position:0% +charge will +necessarily agglomerate without + + align:start position:0% +necessarily agglomerate without + + + align:start position:0% +necessarily agglomerate without +limit agglomerate without limit and what + + align:start position:0% +limit agglomerate without limit and what + + + align:start position:0% +limit agglomerate without limit and what +happens if I put a gazillion of these + + align:start position:0% +happens if I put a gazillion of these + + + align:start position:0% +happens if I put a gazillion of these +things together what's the what's the + + align:start position:0% +things together what's the what's the + + + align:start position:0% +things together what's the what's the +resulting form the resulting form is is + + align:start position:0% +resulting form the resulting form is is + + + align:start position:0% +resulting form the resulting form is is +a solid a solid will form so if you + + align:start position:0% +a solid a solid will form so if you + + + align:start position:0% +a solid a solid will form so if you +start with sodium vapor and chlorine gas + + align:start position:0% +start with sodium vapor and chlorine gas + + + align:start position:0% +start with sodium vapor and chlorine gas +electron transfer will occur and you + + align:start position:0% +electron transfer will occur and you + + + align:start position:0% +electron transfer will occur and you +will form a crystal of sodium chloride + + align:start position:0% +will form a crystal of sodium chloride + + + align:start position:0% +will form a crystal of sodium chloride +as a result of + + align:start position:0% + + + + align:start position:0% + +this need to + + align:start position:0% +this need to + + + align:start position:0% +this need to +form + + align:start position:0% + + + + align:start position:0% + +uh Crystal expressed through the kulms + + align:start position:0% +uh Crystal expressed through the kulms + + + align:start position:0% +uh Crystal expressed through the kulms +law so now I want to take a look at the + + align:start position:0% +law so now I want to take a look at the + + + align:start position:0% +law so now I want to take a look at the +energetics of that let's look at the + + align:start position:0% +energetics of that let's look at the + + + align:start position:0% +energetics of that let's look at the +energetics of uh kum's law I want to + + align:start position:0% +energetics of uh kum's law I want to + + + align:start position:0% +energetics of uh kum's law I want to +talk a little bit uh sort of at a + + align:start position:0% +talk a little bit uh sort of at a + + + align:start position:0% +talk a little bit uh sort of at a +general level about modeling how would I + + align:start position:0% +general level about modeling how would I + + + align:start position:0% +general level about modeling how would I +model this system well there's levels of + + align:start position:0% +model this system well there's levels of + + + align:start position:0% +model this system well there's levels of +models and the bottom line in modeling + + align:start position:0% +models and the bottom line in modeling + + + align:start position:0% +models and the bottom line in modeling +is make it as only as complex as you + + align:start position:0% +is make it as only as complex as you + + + align:start position:0% +is make it as only as complex as you +need to don't put in extra bells and + + align:start position:0% +need to don't put in extra bells and + + + align:start position:0% +need to don't put in extra bells and +whistles if it's not necessary so for + + align:start position:0% +whistles if it's not necessary so for + + + align:start position:0% +whistles if it's not necessary so for +example if I have a sodium ion over here + + align:start position:0% +example if I have a sodium ion over here + + + align:start position:0% +example if I have a sodium ion over here +and I have a chloride ion over + + align:start position:0% +and I have a chloride ion over + + + align:start position:0% +and I have a chloride ion over +here where the distance the distance + + align:start position:0% +here where the distance the distance + + + align:start position:0% +here where the distance the distance +from Center to + + align:start position:0% +from Center to + + + align:start position:0% +from Center to +Center I'm denoting as R this is a + + align:start position:0% +Center I'm denoting as R this is a + + + align:start position:0% +Center I'm denoting as R this is a +nucleus to nucleus separation and let's + + align:start position:0% +nucleus to nucleus separation and let's + + + align:start position:0% +nucleus to nucleus separation and let's +say that sodium + + align:start position:0% +say that sodium + + + align:start position:0% +say that sodium +has a radius + + align:start position:0% +has a radius + + + align:start position:0% +has a radius +r+ and chlorine has a radius R minus + + align:start position:0% +r+ and chlorine has a radius R minus + + + align:start position:0% +r+ and chlorine has a radius R minus +when R when R is very large in + + align:start position:0% +when R when R is very large in + + + align:start position:0% +when R when R is very large in +comparison to the radi of + + align:start position:0% +comparison to the radi of + + + align:start position:0% +comparison to the radi of +the ions I don't need to draw them this + + align:start position:0% +the ions I don't need to draw them this + + + align:start position:0% +the ions I don't need to draw them this +way I can model this whole thing it's + + align:start position:0% +way I can model this whole thing it's + + + align:start position:0% +way I can model this whole thing it's +point charges I could model it as point + + align:start position:0% +point charges I could model it as point + + + align:start position:0% +point charges I could model it as point +charges this is a point that's negative + + align:start position:0% +charges this is a point that's negative + + + align:start position:0% +charges this is a point that's negative +and this is a point that's positive and + + align:start position:0% +and this is a point that's positive and + + + align:start position:0% +and this is a point that's positive and +that's all we need to do and a lot of + + align:start position:0% +that's all we need to do and a lot of + + + align:start position:0% +that's all we need to do and a lot of +the derivations you'll see in physics + + align:start position:0% +the derivations you'll see in physics + + + align:start position:0% +the derivations you'll see in physics +rely on this being able to model as + + align:start position:0% +rely on this being able to model as + + + align:start position:0% +rely on this being able to model as +point charges but what happens when + + align:start position:0% +point charges but what happens when + + + align:start position:0% +point charges but what happens when +these two start to get really close + + align:start position:0% +these two start to get really close + + + align:start position:0% +these two start to get really close +together when they start getting close + + align:start position:0% +together when they start getting close + + + align:start position:0% +together when they start getting close +together there's more + + align:start position:0% +together there's more + + + align:start position:0% +together there's more +complexity complexity takes on this form + + align:start position:0% + + + + align:start position:0% + +so now let's get a + + align:start position:0% +so now let's get a + + + align:start position:0% +so now let's get a +sodium here and the chloride ion next to + + align:start position:0% +sodium here and the chloride ion next to + + + align:start position:0% +sodium here and the chloride ion next to +it to the point where they're touching + + align:start position:0% +it to the point where they're touching + + + align:start position:0% +it to the point where they're touching +so now I'm going to show some fine + + align:start position:0% +so now I'm going to show some fine + + + align:start position:0% +so now I'm going to show some fine +structure yeah this is net + + align:start position:0% +structure yeah this is net + + + align:start position:0% +structure yeah this is net +positive the sodium is net + + align:start position:0% +positive the sodium is net + + + align:start position:0% +positive the sodium is net +positive and the + + align:start position:0% +positive and the + + + align:start position:0% +positive and the +chloride is net + + align:start position:0% + + + + align:start position:0% + +negative and so there's an attractive + + align:start position:0% +negative and so there's an attractive + + + align:start position:0% +negative and so there's an attractive +force between the two of them positive + + align:start position:0% +force between the two of them positive + + + align:start position:0% +force between the two of them positive +and the negative but let's look more + + align:start position:0% +and the negative but let's look more + + + align:start position:0% +and the negative but let's look more +carefully this is uh sodium is net + + align:start position:0% +carefully this is uh sodium is net + + + align:start position:0% +carefully this is uh sodium is net +positive but I've got a nucleus with 11 + + align:start position:0% +positive but I've got a nucleus with 11 + + + align:start position:0% +positive but I've got a nucleus with 11 +protons in it and I've got 10 electrons + + align:start position:0% +protons in it and I've got 10 electrons + + + align:start position:0% +protons in it and I've got 10 electrons +around + + align:start position:0% +around + + + align:start position:0% +around +it and here I've got 17 protons in the + + align:start position:0% +it and here I've got 17 protons in the + + + align:start position:0% +it and here I've got 17 protons in the +nucleus and I've got 18 electrons around + + align:start position:0% +nucleus and I've got 18 electrons around + + + align:start position:0% +nucleus and I've got 18 electrons around +it so when we get really close together + + align:start position:0% +it so when we get really close together + + + align:start position:0% +it so when we get really close together +granted there's a net positive negative + + align:start position:0% +granted there's a net positive negative + + + align:start position:0% +granted there's a net positive negative +charge with a colic Force of Attraction + + align:start position:0% +charge with a colic Force of Attraction + + + align:start position:0% +charge with a colic Force of Attraction +but can you see that as you get really + + align:start position:0% +but can you see that as you get really + + + align:start position:0% +but can you see that as you get really +close together the negative electronic + + align:start position:0% +close together the negative electronic + + + align:start position:0% +close together the negative electronic +clouds surrounding the two ions start to + + align:start position:0% +clouds surrounding the two ions start to + + + align:start position:0% +clouds surrounding the two ions start to +sense one another and there's a mutual + + align:start position:0% +sense one another and there's a mutual + + + align:start position:0% +sense one another and there's a mutual +repulsive Force here there's a repulsive + + align:start position:0% +repulsive Force here there's a repulsive + + + align:start position:0% +repulsive Force here there's a repulsive +Force the attractive force between ions + + align:start position:0% +Force the attractive force between ions + + + align:start position:0% +Force the attractive force between ions +of opposite charge is offset by a + + align:start position:0% +of opposite charge is offset by a + + + align:start position:0% +of opposite charge is offset by a +repulsive repulsive force due to + + align:start position:0% +repulsive repulsive force due to + + + align:start position:0% +repulsive repulsive force due to +electron cloud + + align:start position:0% +electron cloud + + + align:start position:0% +electron cloud +interactions this is the clouds are the + + align:start position:0% +interactions this is the clouds are the + + + align:start position:0% +interactions this is the clouds are the +orbitals electron cloud + + align:start position:0% +orbitals electron cloud + + + align:start position:0% +orbitals electron cloud +interactions and this is what prevents + + align:start position:0% +interactions and this is what prevents + + + align:start position:0% +interactions and this is what prevents +them from collapsing into one another + + align:start position:0% +them from collapsing into one another + + + align:start position:0% +them from collapsing into one another +they reach a certain + + align:start position:0% +they reach a certain + + + align:start position:0% +they reach a certain +equilibrium so what we're going to do + + align:start position:0% +equilibrium so what we're going to do + + + align:start position:0% +equilibrium so what we're going to do +now is look at the energetics associated + + align:start position:0% +now is look at the energetics associated + + + align:start position:0% +now is look at the energetics associated +with that that's given as follows I want + + align:start position:0% +with that that's given as follows I want + + + align:start position:0% +with that that's given as follows I want +to plot energy in this system as a + + align:start position:0% +to plot energy in this system as a + + + align:start position:0% +to plot energy in this system as a +function of interatomic + + align:start position:0% +function of interatomic + + + align:start position:0% +function of interatomic +spacing + + align:start position:0% +spacing + + + align:start position:0% +spacing +so the xaxis is inter Atomic spacing and + + align:start position:0% +so the xaxis is inter Atomic spacing and + + + align:start position:0% +so the xaxis is inter Atomic spacing and +the Y AIS is + + align:start position:0% +the Y AIS is + + + align:start position:0% +the Y AIS is +energy positive energy is + + align:start position:0% +energy positive energy is + + + align:start position:0% +energy positive energy is +repulsive and negative energy is + + align:start position:0% + + + + align:start position:0% + +attractive and I'm going to put the + + align:start position:0% +attractive and I'm going to put the + + + align:start position:0% +attractive and I'm going to put the +sodium atom at the uh at the + + align:start position:0% +sodium atom at the uh at the + + + align:start position:0% +sodium atom at the uh at the +center so here's + + align:start position:0% +center so here's + + + align:start position:0% +center so here's +sodium and I'm going to ask what happens + + align:start position:0% +sodium and I'm going to ask what happens + + + align:start position:0% +sodium and I'm going to ask what happens +when when chlorine comes in so I'll put + + align:start position:0% +when when chlorine comes in so I'll put + + + align:start position:0% +when when chlorine comes in so I'll put +chlorine over here + + align:start position:0% + + + + align:start position:0% + +so this the chloride ion it's over here + + align:start position:0% +so this the chloride ion it's over here + + + align:start position:0% +so this the chloride ion it's over here +and we're going to look at what happens + + align:start position:0% +and we're going to look at what happens + + + align:start position:0% +and we're going to look at what happens +as the chloride ion moves from Infinity + + align:start position:0% +as the chloride ion moves from Infinity + + + align:start position:0% +as the chloride ion moves from Infinity +in towards the positive ion so let's + + align:start position:0% +in towards the positive ion so let's + + + align:start position:0% +in towards the positive ion so let's +first go with the attractive because you + + align:start position:0% +first go with the attractive because you + + + align:start position:0% +first go with the attractive because you +know this already the attractive uh + + align:start position:0% +know this already the attractive uh + + + align:start position:0% +know this already the attractive uh +energy is just a potential energy cumic + + align:start position:0% +energy is just a potential energy cumic + + + align:start position:0% +energy is just a potential energy cumic +potential that's simply q1 Q2 over 4 Pi + + align:start position:0% +potential that's simply q1 Q2 over 4 Pi + + + align:start position:0% +potential that's simply q1 Q2 over 4 Pi +Epsilon 0r and q1 is equal to the charge + + align:start position:0% +Epsilon 0r and q1 is equal to the charge + + + align:start position:0% +Epsilon 0r and q1 is equal to the charge +on sodium Q2 is the charge on chlorine + + align:start position:0% +on sodium Q2 is the charge on chlorine + + + align:start position:0% +on sodium Q2 is the charge on chlorine +so this is uh positive e on the sodium + + align:start position:0% +so this is uh positive e on the sodium + + + align:start position:0% +so this is uh positive e on the sodium +negative e on the chlorine over 4 pi + + align:start position:0% +negative e on the chlorine over 4 pi + + + align:start position:0% +negative e on the chlorine over 4 pi +epsilon0 r which is going to give us + + align:start position:0% +epsilon0 r which is going to give us + + + align:start position:0% +epsilon0 r which is going to give us +minus e^2 over 4 pi epsilon0 r and this + + align:start position:0% +minus e^2 over 4 pi epsilon0 r and this + + + align:start position:0% +minus e^2 over 4 pi epsilon0 r and this +is just a uh + + align:start position:0% +is just a uh + + + align:start position:0% +is just a uh +rectangular uh hyperbola and it's going + + align:start position:0% +rectangular uh hyperbola and it's going + + + align:start position:0% +rectangular uh hyperbola and it's going +to look like + + align:start position:0% +to look like + + + align:start position:0% +to look like +this so this is the E + + align:start position:0% +this so this is the E + + + align:start position:0% +this so this is the E +attractive and infinity there's no + + align:start position:0% +attractive and infinity there's no + + + align:start position:0% +attractive and infinity there's no +stored potential energy and it drops off + + align:start position:0% +stored potential energy and it drops off + + + align:start position:0% +stored potential energy and it drops off +more and more negative as 1 / + + align:start position:0% +more and more negative as 1 / + + + align:start position:0% +more and more negative as 1 / +R now how about this repulsion between + + align:start position:0% +R now how about this repulsion between + + + align:start position:0% +R now how about this repulsion between +electrons this is not a cumic force it's + + align:start position:0% +electrons this is not a cumic force it's + + + align:start position:0% +electrons this is not a cumic force it's +very different the repulsive term the + + align:start position:0% +very different the repulsive term the + + + align:start position:0% +very different the repulsive term the +repulsive term goes as some constant + + align:start position:0% +repulsive term goes as some constant + + + align:start position:0% +repulsive term goes as some constant +lowercase b divided by R to the n n is + + align:start position:0% +lowercase b divided by R to the n n is + + + align:start position:0% +lowercase b divided by R to the n n is +not the quantum number N is a is a power + + align:start position:0% +not the quantum number N is a is a power + + + align:start position:0% +not the quantum number N is a is a power +law factor in here and it's given by + + align:start position:0% +law factor in here and it's given by + + + align:start position:0% +law factor in here and it's given by +what is called the born exponent the + + align:start position:0% +what is called the born exponent the + + + align:start position:0% +what is called the born exponent the +born exponent and it's a very high + + align:start position:0% +born exponent and it's a very high + + + align:start position:0% +born exponent and it's a very high +number why is it a high number because + + align:start position:0% +number why is it a high number because + + + align:start position:0% +number why is it a high number because +it has to drop off precipitously when + + align:start position:0% +it has to drop off precipitously when + + + align:start position:0% +it has to drop off precipitously when +you get one over R you get a gradual + + align:start position:0% +you get one over R you get a gradual + + + align:start position:0% +you get one over R you get a gradual +fall if you get one over R squar it'll + + align:start position:0% +fall if you get one over R squar it'll + + + align:start position:0% +fall if you get one over R squar it'll +be a little steeper 1 / R to the 6 will + + align:start position:0% +be a little steeper 1 / R to the 6 will + + + align:start position:0% +be a little steeper 1 / R to the 6 will +come in and then jump off precipitously + + align:start position:0% +come in and then jump off precipitously + + + align:start position:0% +come in and then jump off precipitously +and that's what you want because the + + align:start position:0% +and that's what you want because the + + + align:start position:0% +and that's what you want because the +electron electron repulsion is only felt + + align:start position:0% +electron electron repulsion is only felt + + + align:start position:0% +electron electron repulsion is only felt +which you when you're in really really + + align:start position:0% +which you when you're in really really + + + align:start position:0% +which you when you're in really really +close and then it for all intents and + + align:start position:0% +close and then it for all intents and + + + align:start position:0% +close and then it for all intents and +purposes Falls to zero so the born + + align:start position:0% +purposes Falls to zero so the born + + + align:start position:0% +purposes Falls to zero so the born +exponent typically takes values of + + align:start position:0% +exponent typically takes values of + + + align:start position:0% +exponent typically takes values of +between 6 and 12 and B is some constant + + align:start position:0% +between 6 and 12 and B is some constant + + + align:start position:0% +between 6 and 12 and B is some constant +that we have to determine so what's uh 1 + + align:start position:0% +that we have to determine so what's uh 1 + + + align:start position:0% +that we have to determine so what's uh 1 +/ R to the 8th going to look like on + + align:start position:0% +/ R to the 8th going to look like on + + + align:start position:0% +/ R to the 8th going to look like on +this scale it's going to look like this + + align:start position:0% +this scale it's going to look like this + + + align:start position:0% +this scale it's going to look like this +it's going to hug the x axis until it + + align:start position:0% +it's going to hug the x axis until it + + + align:start position:0% +it's going to hug the x axis until it +gets in very very close and then it's + + align:start position:0% +gets in very very close and then it's + + + align:start position:0% +gets in very very close and then it's +going to take off like a shot so this is + + align:start position:0% +going to take off like a shot so this is + + + align:start position:0% +going to take off like a shot so this is +the the repulsive energy turn and so + + align:start position:0% +the the repulsive energy turn and so + + + align:start position:0% +the the repulsive energy turn and so +what's the net energy the net energy is + + align:start position:0% +what's the net energy the net energy is + + + align:start position:0% +what's the net energy the net energy is +the sum of the repulsive and the + + align:start position:0% +the sum of the repulsive and the + + + align:start position:0% +the sum of the repulsive and the +attractive and see out at very very high + + align:start position:0% +attractive and see out at very very high + + + align:start position:0% +attractive and see out at very very high +separation ation it's essentially all + + align:start position:0% +separation ation it's essentially all + + + align:start position:0% +separation ation it's essentially all +repulsive excuse me all attractive and + + align:start position:0% +repulsive excuse me all attractive and + + + align:start position:0% +repulsive excuse me all attractive and +at very very low separations it's all + + align:start position:0% +at very very low separations it's all + + + align:start position:0% +at very very low separations it's all +repulsive and in between it goes through + + align:start position:0% +repulsive and in between it goes through + + + align:start position:0% +repulsive and in between it goes through +a minimum and this minimum here is what + + align:start position:0% +a minimum and this minimum here is what + + + align:start position:0% +a minimum and this minimum here is what +gives us the value of the inter + + align:start position:0% +gives us the value of the inter + + + align:start position:0% +gives us the value of the inter +electrode separation the inter ion + + align:start position:0% +electrode separation the inter ion + + + align:start position:0% +electrode separation the inter ion +separation and so I need to I need to + + align:start position:0% +separation and so I need to I need to + + + align:start position:0% +separation and so I need to I need to +cheat a little bit on the drawing and + + align:start position:0% +cheat a little bit on the drawing and + + + align:start position:0% +cheat a little bit on the drawing and +make sure that this minimum + + align:start position:0% +make sure that this minimum + + + align:start position:0% +make sure that this minimum +occurs right + + align:start position:0% +occurs right + + + align:start position:0% +occurs right +here okay so our minimum + + align:start position:0% +here okay so our minimum + + + align:start position:0% +here okay so our minimum +the minimum uh separation occurs when + + align:start position:0% +the minimum uh separation occurs when + + + align:start position:0% +the minimum uh separation occurs when +the energy is at its minimum and that's + + align:start position:0% +the energy is at its minimum and that's + + + align:start position:0% +the energy is at its minimum and that's +given by the balance between the + + align:start position:0% +given by the balance between the + + + align:start position:0% +given by the balance between the +attractive force of the ions offset by + + align:start position:0% +attractive force of the ions offset by + + + align:start position:0% +attractive force of the ions offset by +the repulsive force in the electronic + + align:start position:0% +the repulsive force in the electronic + + + align:start position:0% +the repulsive force in the electronic +shells and what we'll do next day is + + align:start position:0% +shells and what we'll do next day is + + + align:start position:0% +shells and what we'll do next day is +we'll uh look at the consequences of + + align:start position:0% +we'll uh look at the consequences of + + + align:start position:0% +we'll uh look at the consequences of +such an energetic uh setup and + + align:start position:0% +such an energetic uh setup and + + + align:start position:0% +such an energetic uh setup and +rationalize that when ions form + + align:start position:0% +rationalize that when ions form + + + align:start position:0% +rationalize that when ions form +by necessity we must form ionic + + align:start position:0% +by necessity we must form ionic + + + align:start position:0% +by necessity we must form ionic +crystals so I think with that I'll shift + + align:start position:0% +crystals so I think with that I'll shift + + + align:start position:0% +crystals so I think with that I'll shift +over + + align:start position:0% +over + + + align:start position:0% +over +to uh some external matters uh we've + + align:start position:0% +to uh some external matters uh we've + + + align:start position:0% +to uh some external matters uh we've +seen so far that we can have a neutral + + align:start position:0% +seen so far that we can have a neutral + + + align:start position:0% +seen so far that we can have a neutral +plus neutral sodium plus chlorine goes + + align:start position:0% +plus neutral sodium plus chlorine goes + + + align:start position:0% +plus neutral sodium plus chlorine goes +to cation plus anion that's what we've + + align:start position:0% +to cation plus anion that's what we've + + + align:start position:0% +to cation plus anion that's what we've +just been looking at and this occurs in + + align:start position:0% +just been looking at and this occurs in + + + align:start position:0% +just been looking at and this occurs in +order to achieve octet stability well + + align:start position:0% +order to achieve octet stability well + + + align:start position:0% +order to achieve octet stability well +it's possible to reverse this it's Poss + + align:start position:0% +it's possible to reverse this it's Poss + + + align:start position:0% +it's possible to reverse this it's Poss +possible to take the cation and anion + + align:start position:0% +possible to take the cation and anion + + + align:start position:0% +possible to take the cation and anion +and restore them to their neutral States + + align:start position:0% +and restore them to their neutral States + + + align:start position:0% +and restore them to their neutral States +so for example in an electrochemical + + align:start position:0% +so for example in an electrochemical + + + align:start position:0% +so for example in an electrochemical +cell it would be possible to take the + + align:start position:0% +cell it would be possible to take the + + + align:start position:0% +cell it would be possible to take the +sodium ion give back its electron and + + align:start position:0% +sodium ion give back its electron and + + + align:start position:0% +sodium ion give back its electron and +convert it into metallic sodium take the + + align:start position:0% +convert it into metallic sodium take the + + + align:start position:0% +convert it into metallic sodium take the +chloride ion remove its electron and + + align:start position:0% +chloride ion remove its electron and + + + align:start position:0% +chloride ion remove its electron and +restore chlorine gas so this is what + + align:start position:0% +restore chlorine gas so this is what + + + align:start position:0% +restore chlorine gas so this is what +goes on in electrolysis cell and it + + align:start position:0% +goes on in electrolysis cell and it + + + align:start position:0% +goes on in electrolysis cell and it +works thanks to input energy from a + + align:start position:0% +works thanks to input energy from a + + + align:start position:0% +works thanks to input energy from a +power supply shown here so that's Point + + align:start position:0% +power supply shown here so that's Point + + + align:start position:0% +power supply shown here so that's Point +number one point number two is that + + align:start position:0% +number one point number two is that + + + align:start position:0% +number one point number two is that +ionic solids at high temperatures make + + align:start position:0% +ionic solids at high temperatures make + + + align:start position:0% +ionic solids at high temperatures make +ionic liquids so one such ionic liquid + + align:start position:0% +ionic liquids so one such ionic liquid + + + align:start position:0% +ionic liquids so one such ionic liquid +is magnesium chloride magnesium chloride + + align:start position:0% +is magnesium chloride magnesium chloride + + + align:start position:0% +is magnesium chloride magnesium chloride +is + + align:start position:0% +is + + + align:start position:0% +is +the raw material for the production of + + align:start position:0% +the raw material for the production of + + + align:start position:0% +the raw material for the production of +magnesium this is Magnesium it's the + + align:start position:0% +magnesium this is Magnesium it's the + + + align:start position:0% +magnesium this is Magnesium it's the +lightest of the con structural Metals + + align:start position:0% +lightest of the con structural Metals + + + align:start position:0% +lightest of the con structural Metals +it's got a density of about 1.76 at room + + align:start position:0% +it's got a density of about 1.76 at room + + + align:start position:0% +it's got a density of about 1.76 at room +temperature uh for comparison aluminum + + align:start position:0% +temperature uh for comparison aluminum + + + align:start position:0% +temperature uh for comparison aluminum +is + + align:start position:0% +is + + + align:start position:0% +is +2.7 so this is about aluminum is about + + align:start position:0% +2.7 so this is about aluminum is about + + + align:start position:0% +2.7 so this is about aluminum is about +50% denser than magnesium steel is 7.87 + + align:start position:0% +50% denser than magnesium steel is 7.87 + + + align:start position:0% +50% denser than magnesium steel is 7.87 +so this is about a quarter the density + + align:start position:0% +so this is about a quarter the density + + + align:start position:0% +so this is about a quarter the density +of Steel so if you could make + + align:start position:0% +of Steel so if you could make + + + align:start position:0% +of Steel so if you could make +automobiles with a high magnesium + + align:start position:0% +automobiles with a high magnesium + + + align:start position:0% +automobiles with a high magnesium +content you would reduce the mass reduce + + align:start position:0% +content you would reduce the mass reduce + + + align:start position:0% +content you would reduce the mass reduce +the energy required and thereby reduce + + align:start position:0% +the energy required and thereby reduce + + + align:start position:0% +the energy required and thereby reduce +the environmental impact clearly if I + + align:start position:0% +the environmental impact clearly if I + + + align:start position:0% +the environmental impact clearly if I +did nothing more but I took every car + + align:start position:0% +did nothing more but I took every car + + + align:start position:0% +did nothing more but I took every car +doubled its fuel economy its emissions + + align:start position:0% +doubled its fuel economy its emissions + + + align:start position:0% +doubled its fuel economy its emissions +would go to 50% of what they are now no + + align:start position:0% +would go to 50% of what they are now no + + + align:start position:0% +would go to 50% of what they are now no +other changes being made so fuel economy + + align:start position:0% +other changes being made so fuel economy + + + align:start position:0% +other changes being made so fuel economy +and environmental Conservancy make a lot + + align:start position:0% +and environmental Conservancy make a lot + + + align:start position:0% +and environmental Conservancy make a lot +of sense if you care about such things + + align:start position:0% +of sense if you care about such things + + + align:start position:0% +of sense if you care about such things +of course so here's magnesium it's very + + align:start position:0% +of course so here's magnesium it's very + + + align:start position:0% +of course so here's magnesium it's very +light takes energy and this is how it's + + align:start position:0% +light takes energy and this is how it's + + + align:start position:0% +light takes energy and this is how it's +made electrolysis of of magnesium + + align:start position:0% +made electrolysis of of magnesium + + + align:start position:0% +made electrolysis of of magnesium +chloride in a Cell where the one + + align:start position:0% +chloride in a Cell where the one + + + align:start position:0% +chloride in a Cell where the one +electrode we make magnesium the other + + align:start position:0% +electrode we make magnesium the other + + + align:start position:0% +electrode we make magnesium the other +electrode we make chlorine gas and so + + align:start position:0% +electrode we make chlorine gas and so + + + align:start position:0% +electrode we make chlorine gas and so +the question becomes well what are the + + align:start position:0% +the question becomes well what are the + + + align:start position:0% +the question becomes well what are the +resources for magnesium do we have + + align:start position:0% +resources for magnesium do we have + + + align:start position:0% +resources for magnesium do we have +magnesium to do this so I went to the + + align:start position:0% +magnesium to do this so I went to the + + + align:start position:0% +magnesium to do this so I went to the +library and I looked up uh advances in + + align:start position:0% +library and I looked up uh advances in + + + align:start position:0% +library and I looked up uh advances in +molten salt chemistry volume 6 because + + align:start position:0% +molten salt chemistry volume 6 because + + + align:start position:0% +molten salt chemistry volume 6 because +there's an article in there about the + + align:start position:0% +there's an article in there about the + + + align:start position:0% +there's an article in there about the +chemistry and electrochemistry of + + align:start position:0% +chemistry and electrochemistry of + + + align:start position:0% +chemistry and electrochemistry of +magnesium production so I went I went to + + align:start position:0% +magnesium production so I went I went to + + + align:start position:0% +magnesium production so I went I went to +look up the the authoritative Source on + + align:start position:0% +look up the the authoritative Source on + + + align:start position:0% +look up the the authoritative Source on +this and uh so I uh I looked at I looked + + align:start position:0% +this and uh so I uh I looked at I looked + + + align:start position:0% +this and uh so I uh I looked at I looked +this up and and I want to give you a + + align:start position:0% +this up and and I want to give you a + + + align:start position:0% +this up and and I want to give you a +sense of of what the truth is people + + align:start position:0% +sense of of what the truth is people + + + align:start position:0% +sense of of what the truth is people +tell you that we're resource + + align:start position:0% +tell you that we're resource + + + align:start position:0% +tell you that we're resource +constrainted that we're running out of + + align:start position:0% +constrainted that we're running out of + + + align:start position:0% +constrainted that we're running out of +resources well think about this where + + align:start position:0% +resources well think about this where + + + align:start position:0% +resources well think about this where +are the data a cubic kilometer of + + align:start position:0% +are the data a cubic kilometer of + + + align:start position:0% +are the data a cubic kilometer of +seawater that's a go into the ocean and + + align:start position:0% +seawater that's a go into the ocean and + + + align:start position:0% +seawater that's a go into the ocean and +imagine a box 1 kilometer by 1 kilm by 1 + + align:start position:0% +imagine a box 1 kilometer by 1 kilm by 1 + + + align:start position:0% +imagine a box 1 kilometer by 1 kilm by 1 +kilm that's a cubic kilometer contains a + + align:start position:0% +kilm that's a cubic kilometer contains a + + + align:start position:0% +kilm that's a cubic kilometer contains a +million tons of magnesium a million tons + + align:start position:0% +million tons of magnesium a million tons + + + align:start position:0% +million tons of magnesium a million tons +which is more than has ever been + + align:start position:0% +which is more than has ever been + + + align:start position:0% +which is more than has ever been +produced in one year by all the + + align:start position:0% +produced in one year by all the + + + align:start position:0% +produced in one year by all the +Magnesium plants in the world annual + + align:start position:0% +Magnesium plants in the world annual + + + align:start position:0% +Magnesium plants in the world annual +production of magnesium is about 600,000 + + align:start position:0% +production of magnesium is about 600,000 + + + align:start position:0% +production of magnesium is about 600,000 +tons per year you get that out of 1 + + align:start position:0% +tons per year you get that out of 1 + + + align:start position:0% +tons per year you get that out of 1 +cubic kilometer of + + align:start position:0% +cubic kilometer of + + + align:start position:0% +cubic kilometer of +seawater and seawat contains only 3.7% + + align:start position:0% +seawater and seawat contains only 3.7% + + + align:start position:0% +seawater and seawat contains only 3.7% +of the total magnesium present in the + + align:start position:0% +of the total magnesium present in the + + + align:start position:0% +of the total magnesium present in the +Earth's + + align:start position:0% +Earth's + + + align:start position:0% +Earth's +crust so clearly magnesium resource are + + align:start position:0% +crust so clearly magnesium resource are + + + align:start position:0% +crust so clearly magnesium resource are +ubiquitous and virtually inexhaustible + + align:start position:0% +ubiquitous and virtually inexhaustible + + + align:start position:0% +ubiquitous and virtually inexhaustible +there's lots of + + align:start position:0% +there's lots of + + + align:start position:0% +there's lots of +magnesium there's lots of magnesium so + + align:start position:0% +magnesium there's lots of magnesium so + + + align:start position:0% +magnesium there's lots of magnesium so +if magnesium is so + + align:start position:0% +if magnesium is so + + + align:start position:0% +if magnesium is so +abundant why is it so expensive steel is + + align:start position:0% +abundant why is it so expensive steel is + + + align:start position:0% +abundant why is it so expensive steel is +about 10 cents a pound aluminum is about + + align:start position:0% +about 10 cents a pound aluminum is about + + + align:start position:0% +about 10 cents a pound aluminum is about +70 cents a pound and magnesium is over a + + align:start position:0% +70 cents a pound and magnesium is over a + + + align:start position:0% +70 cents a pound and magnesium is over a +dollar a pound why is it so expensive + + align:start position:0% +dollar a pound why is it so expensive + + + align:start position:0% +dollar a pound why is it so expensive +it's not because of scarcity it's + + align:start position:0% +it's not because of scarcity it's + + + align:start position:0% +it's not because of scarcity it's +expensive because the process by which + + align:start position:0% +expensive because the process by which + + + align:start position:0% +expensive because the process by which +we produce it is energy intensive and + + align:start position:0% +we produce it is energy intensive and + + + align:start position:0% +we produce it is energy intensive and +resource intensive so if we want to get + + align:start position:0% +resource intensive so if we want to get + + + align:start position:0% +resource intensive so if we want to get +more magnesium into the marketplace at + + align:start position:0% +more magnesium into the marketplace at + + + align:start position:0% +more magnesium into the marketplace at +an affordable price not by government + + align:start position:0% +an affordable price not by government + + + align:start position:0% +an affordable price not by government +edict what do we have to do we have to + + align:start position:0% +edict what do we have to do we have to + + + align:start position:0% +edict what do we have to do we have to +invent a process a chemical extraction + + align:start position:0% +invent a process a chemical extraction + + + align:start position:0% +invent a process a chemical extraction +process that will make the production of + + align:start position:0% +process that will make the production of + + + align:start position:0% +process that will make the production of +magnesium cheaper so that we will have + + align:start position:0% +magnesium cheaper so that we will have + + + align:start position:0% +magnesium cheaper so that we will have +the opportunity to Avail ourselves of + + align:start position:0% +the opportunity to Avail ourselves of + + + align:start position:0% +the opportunity to Avail ourselves of +energy efficient materials and so maybe + + align:start position:0% +energy efficient materials and so maybe + + + align:start position:0% +energy efficient materials and so maybe +somebody in this room + + align:start position:0% +somebody in this room + + + align:start position:0% +somebody in this room +working with me will invent such a + + align:start position:0% +working with me will invent such a + + + align:start position:0% +working with me will invent such a +process all right I'll see you on Friday \ No newline at end of file diff --git a/WacNWdXhvVM.txt b/WacNWdXhvVM.txt new file mode 100644 index 0000000000000000000000000000000000000000..c459c94a034a8e8322f5a3bf3a842ecef1508865 --- /dev/null +++ b/WacNWdXhvVM.txt @@ -0,0 +1,995 @@ +align:start position:0% + +today's lecture is a story of Moneyball + + align:start position:0% +today's lecture is a story of Moneyball + + + align:start position:0% +today's lecture is a story of Moneyball +a book my Michael Lewis in 2003 and a + + align:start position:0% +a book my Michael Lewis in 2003 and a + + + align:start position:0% +a book my Michael Lewis in 2003 and a +movie in 2011 starring Brad Pitt + + align:start position:0% +movie in 2011 starring Brad Pitt + + + align:start position:0% +movie in 2011 starring Brad Pitt +Moneyball discusses how Sports analytics + + align:start position:0% +Moneyball discusses how Sports analytics + + + align:start position:0% +Moneyball discusses how Sports analytics +changed baseball Moneyball tells the + + align:start position:0% +changed baseball Moneyball tells the + + + align:start position:0% +changed baseball Moneyball tells the +story of the oakland a's the a's is a + + align:start position:0% +story of the oakland a's the a's is a + + + align:start position:0% +story of the oakland a's the a's is a +team near san francisco california they + + align:start position:0% +team near san francisco california they + + + align:start position:0% +team near san francisco california they +were once a rich team but the team was + + align:start position:0% +were once a rich team but the team was + + + align:start position:0% +were once a rich team but the team was +purchased in 1995 by owners who enforce + + align:start position:0% +purchased in 1995 by owners who enforce + + + align:start position:0% +purchased in 1995 by owners who enforce +strict budget cuts despite this they + + align:start position:0% +strict budget cuts despite this they + + + align:start position:0% +strict budget cuts despite this they +were improving over the years 1997 to + + align:start position:0% +were improving over the years 1997 to + + + align:start position:0% +were improving over the years 1997 to +2001 in the table you can see that the + + align:start position:0% +2001 in the table you can see that the + + + align:start position:0% +2001 in the table you can see that the +percentage of wins was increasing in + + align:start position:0% +percentage of wins was increasing in + + + align:start position:0% +percentage of wins was increasing in +each and every year this was puzzling + + align:start position:0% +each and every year this was puzzling + + + align:start position:0% +each and every year this was puzzling +and many baseball experts thought it was + + align:start position:0% +and many baseball experts thought it was + + + align:start position:0% +and many baseball experts thought it was +just luck in 2002 the A's lost three key + + align:start position:0% +just luck in 2002 the A's lost three key + + + align:start position:0% +just luck in 2002 the A's lost three key +players the key question could they + + align:start position:0% +players the key question could they + + + align:start position:0% +players the key question could they +continue winning without them so what is + + align:start position:0% +continue winning without them so what is + + + align:start position:0% +continue winning without them so what is +the key problem let us discuss the graph + + align:start position:0% +the key problem let us discuss the graph + + + align:start position:0% +the key problem let us discuss the graph +on the left of the screen the horizontal + + align:start position:0% +on the left of the screen the horizontal + + + align:start position:0% +on the left of the screen the horizontal +axis so the average payroll during the + + align:start position:0% +axis so the average payroll during the + + + align:start position:0% +axis so the average payroll during the +years 1998 to 2001 the vertical axis + + align:start position:0% +years 1998 to 2001 the vertical axis + + + align:start position:0% +years 1998 to 2001 the vertical axis +shows the average yearly wins over the + + align:start position:0% +shows the average yearly wins over the + + + align:start position:0% +shows the average yearly wins over the +same years so let's look at some of the + + align:start position:0% +same years so let's look at some of the + + + align:start position:0% +same years so let's look at some of the +teams in this graph so which one is this + + align:start position:0% +teams in this graph so which one is this + + + align:start position:0% +teams in this graph so which one is this +team this is a team that won about a + + align:start position:0% +team this is a team that won about a + + + align:start position:0% +team this is a team that won about a +hundred games and spent roughly ninety + + align:start position:0% +hundred games and spent roughly ninety + + + align:start position:0% +hundred games and spent roughly ninety +million during this period so this is + + align:start position:0% +million during this period so this is + + + align:start position:0% +million during this period so this is +the New York Yankees let's look at this + + align:start position:0% +the New York Yankees let's look at this + + + align:start position:0% +the New York Yankees let's look at this +team this team spent about eighty + + align:start position:0% +team this team spent about eighty + + + align:start position:0% +team this team spent about eighty +million and and won about 90 games this + + align:start position:0% +million and and won about 90 games this + + + align:start position:0% +million and and won about 90 games this +is the Red Sox + + align:start position:0% + + + + align:start position:0% + +where are the oakland a's the a's are + + align:start position:0% +where are the oakland a's the a's are + + + align:start position:0% +where are the oakland a's the a's are +here they won about 90 games and they + + align:start position:0% +here they won about 90 games and they + + + align:start position:0% +here they won about 90 games and they +spend under 30 million if you compare it + + align:start position:0% +spend under 30 million if you compare it + + + align:start position:0% +spend under 30 million if you compare it +with the Red Sox they won about the same + + align:start position:0% +with the Red Sox they won about the same + + + align:start position:0% +with the Red Sox they won about the same +number of games during this period but + + align:start position:0% +number of games during this period but + + + align:start position:0% +number of games during this period but +the Red Sox spent about 50 million more + + align:start position:0% +the Red Sox spent about 50 million more + + + align:start position:0% +the Red Sox spent about 50 million more +per year than the A's clearly rich teams + + align:start position:0% +per year than the A's clearly rich teams + + + align:start position:0% +per year than the A's clearly rich teams +like the Yankees and the Red Sox can + + align:start position:0% +like the Yankees and the Red Sox can + + + align:start position:0% +like the Yankees and the Red Sox can +afford the all-star players but please + + align:start position:0% +afford the all-star players but please + + + align:start position:0% +afford the all-star players but please +observe how efficient the A's are as I + + align:start position:0% +observe how efficient the A's are as I + + + align:start position:0% +observe how efficient the A's are as I +mentioned they won 90 games and their + + align:start position:0% +mentioned they won 90 games and their + + + align:start position:0% +mentioned they won 90 games and their +payroll was under 30 million compared to + + align:start position:0% +payroll was under 30 million compared to + + + align:start position:0% +payroll was under 30 million compared to +the Yankees who spent almost three to + + align:start position:0% +the Yankees who spent almost three to + + + align:start position:0% +the Yankees who spent almost three to +four times as much and they won of + + align:start position:0% +four times as much and they won of + + + align:start position:0% +four times as much and they won of +course more than more games but not that + + align:start position:0% +course more than more games but not that + + + align:start position:0% +course more than more games but not that +much more so rich teams as I mentioned + + align:start position:0% +much more so rich teams as I mentioned + + + align:start position:0% +much more so rich teams as I mentioned +have three to four times the payroll of + + align:start position:0% +have three to four times the payroll of + + + align:start position:0% +have three to four times the payroll of +poor teams yet the aides made the + + align:start position:0% +poor teams yet the aides made the + + + align:start position:0% +poor teams yet the aides made the +payroll every year made the play of + + align:start position:0% +payroll every year made the play of + + + align:start position:0% +payroll every year made the play of +cement every year how do they do this + + align:start position:0% +cement every year how do they do this + + + align:start position:0% +cement every year how do they do this +and what we will see in this lecture is + + align:start position:0% +and what we will see in this lecture is + + + align:start position:0% +and what we will see in this lecture is +that by taking a quantitative approach + + align:start position:0% +that by taking a quantitative approach + + + align:start position:0% +that by taking a quantitative approach +an analytics approach they were able to + + align:start position:0% +an analytics approach they were able to + + + align:start position:0% +an analytics approach they were able to +find undervalued players and form teams + + align:start position:0% +find undervalued players and form teams + + + align:start position:0% +find undervalued players and form teams +that were very efficient so V Hayes + + align:start position:0% +that were very efficient so V Hayes + + + align:start position:0% +that were very efficient so V Hayes +started using a different method to + + align:start position:0% +started using a different method to + + + align:start position:0% +started using a different method to +select players the traditional way of + + align:start position:0% +select players the traditional way of + + + align:start position:0% +select players the traditional way of +selecting players was through scouting + + align:start position:0% +selecting players was through scouting + + + align:start position:0% +selecting players was through scouting +Scouts would watch high school and + + align:start position:0% +Scouts would watch high school and + + + align:start position:0% +Scouts would watch high school and +college players and they would report + + align:start position:0% +college players and they would report + + + align:start position:0% +college players and they would report +back about their skills especially + + align:start position:0% +back about their skills especially + + + align:start position:0% +back about their skills especially +discussing their speed and their + + align:start position:0% +discussing their speed and their + + + align:start position:0% +discussing their speed and their +athletic build the ACE however selected + + align:start position:0% +athletic build the ACE however selected + + + align:start position:0% +athletic build the ACE however selected +players based on their statistics not on + + align:start position:0% +players based on their statistics not on + + + align:start position:0% +players based on their statistics not on +their looks + + align:start position:0% +their looks + + + align:start position:0% +their looks +the following are quotes from the book + + align:start position:0% +the following are quotes from the book + + + align:start position:0% +the following are quotes from the book +Moneyball the statistics enable you to + + align:start position:0% +Moneyball the statistics enable you to + + + align:start position:0% +Moneyball the statistics enable you to +find your way past all sorts of site + + align:start position:0% +find your way past all sorts of site + + + align:start position:0% +find your way past all sorts of site +based scouting prejudiced in a direct + + align:start position:0% +based scouting prejudiced in a direct + + + align:start position:0% +based scouting prejudiced in a direct +quote from Billy Beane the manager + + align:start position:0% +quote from Billy Beane the manager + + + align:start position:0% +quote from Billy Beane the manager +of the Oakland A's in the architect of + + align:start position:0% +of the Oakland A's in the architect of + + + align:start position:0% +of the Oakland A's in the architect of +this approach with we are not selling + + align:start position:0% +this approach with we are not selling + + + align:start position:0% +this approach with we are not selling +jeans here let us construct contrast how + + align:start position:0% +jeans here let us construct contrast how + + + align:start position:0% +jeans here let us construct contrast how +the aides selected players versus the + + align:start position:0% +the aides selected players versus the + + + align:start position:0% +the aides selected players versus the +Yankees on the left you see a catcher + + align:start position:0% +Yankees on the left you see a catcher + + + align:start position:0% +Yankees on the left you see a catcher +Scott Hatteberg that he a selected who + + align:start position:0% +Scott Hatteberg that he a selected who + + + align:start position:0% +Scott Hatteberg that he a selected who +would not throw particularly well but + + align:start position:0% +would not throw particularly well but + + + align:start position:0% +would not throw particularly well but +got on base a lot on the right you see + + align:start position:0% +got on base a lot on the right you see + + + align:start position:0% +got on base a lot on the right you see +Derek Jeter one of the top players in + + align:start position:0% +Derek Jeter one of the top players in + + + align:start position:0% +Derek Jeter one of the top players in +baseball a consistent sore top shortstop + + align:start position:0% +baseball a consistent sore top shortstop + + + align:start position:0% +baseball a consistent sore top shortstop +and the leader in hits and stolen bases + + align:start position:0% + + + + align:start position:0% + +let us look into pictures on the left + + align:start position:0% +let us look into pictures on the left + + + align:start position:0% +let us look into pictures on the left +you see Chad Bradford a pitcher for the + + align:start position:0% +you see Chad Bradford a pitcher for the + + + align:start position:0% +you see Chad Bradford a pitcher for the +A's a submariner who used the + + align:start position:0% +A's a submariner who used the + + + align:start position:0% +A's a submariner who used the +non-conventional delivery and slow speed + + align:start position:0% +non-conventional delivery and slow speed + + + align:start position:0% +non-conventional delivery and slow speed +on the right you see Roger Clemens one + + align:start position:0% +on the right you see Roger Clemens one + + + align:start position:0% +on the right you see Roger Clemens one +of the best pitchers in the game that + + align:start position:0% +of the best pitchers in the game that + + + align:start position:0% +of the best pitchers in the game that +use conventional delivery and fast speed + + align:start position:0% +use conventional delivery and fast speed + + + align:start position:0% +use conventional delivery and fast speed +Billy Beane was the manager of the + + align:start position:0% +Billy Beane was the manager of the + + + align:start position:0% +Billy Beane was the manager of the +Oakland A's since 1997 he played major + + align:start position:0% +Oakland A's since 1997 he played major + + + align:start position:0% +Oakland A's since 1997 he played major +league baseball but he was not a great + + align:start position:0% +league baseball but he was not a great + + + align:start position:0% +league baseball but he was not a great +player in fact he sees himself as a + + align:start position:0% +player in fact he sees himself as a + + + align:start position:0% +player in fact he sees himself as a +typical scouting error in the 1980s and + + align:start position:0% +typical scouting error in the 1980s and + + + align:start position:0% +typical scouting error in the 1980s and +1990s analysts were hired by baseball + + align:start position:0% +1990s analysts were hired by baseball + + + align:start position:0% +1990s analysts were hired by baseball +teams but none of them had enough power + + align:start position:0% +teams but none of them had enough power + + + align:start position:0% +teams but none of them had enough power +to affect anything important as I + + align:start position:0% +to affect anything important as I + + + align:start position:0% +to affect anything important as I +mentioned Billy Beane became the general + + align:start position:0% +mentioned Billy Beane became the general + + + align:start position:0% +mentioned Billy Beane became the general +manager of the Oakland A's in 1997 and + + align:start position:0% +manager of the Oakland A's in 1997 and + + + align:start position:0% +manager of the Oakland A's in 1997 and +he was given another small budget he + + align:start position:0% +he was given another small budget he + + + align:start position:0% +he was given another small budget he +understood the importance of analytics + + align:start position:0% +understood the importance of analytics + + + align:start position:0% +understood the importance of analytics +but during this period most general + + align:start position:0% +but during this period most general + + + align:start position:0% +but during this period most general +managers knew little about statistics + + align:start position:0% +managers knew little about statistics + + + align:start position:0% +managers knew little about statistics +and based decisions primarily on + + align:start position:0% +and based decisions primarily on + + + align:start position:0% +and based decisions primarily on +feelings + + align:start position:0% +feelings + + + align:start position:0% +feelings +in contrast Billy Beane hired Paul + + align:start position:0% +in contrast Billy Beane hired Paul + + + align:start position:0% +in contrast Billy Beane hired Paul +DePodesta a - gradual as his assistant + + align:start position:0% +DePodesta a - gradual as his assistant + + + align:start position:0% +DePodesta a - gradual as his assistant +furthermore he was not afraid to + + align:start position:0% +furthermore he was not afraid to + + + align:start position:0% +furthermore he was not afraid to +eliminate Scouts managers and players if + + align:start position:0% +eliminate Scouts managers and players if + + + align:start position:0% +eliminate Scouts managers and players if +the quantity + + align:start position:0% +the quantity + + + align:start position:0% +the quantity +approach suggested decisions that were + + align:start position:0% +approach suggested decisions that were + + + align:start position:0% +approach suggested decisions that were +different than the scouts or the + + align:start position:0% +different than the scouts or the + + + align:start position:0% +different than the scouts or the +managers or the players suggested an + + align:start position:0% +managers or the players suggested an + + + align:start position:0% +managers or the players suggested an +important player and an important player + + align:start position:0% +important player and an important player + + + align:start position:0% +important player and an important player +in this in a story in spaulder Podesta a + + align:start position:0% +in this in a story in spaulder Podesta a + + + align:start position:0% +in this in a story in spaulder Podesta a +Harvard graduate Paul spent a lot of + + align:start position:0% +Harvard graduate Paul spent a lot of + + + align:start position:0% +Harvard graduate Paul spent a lot of +time looking at the data the analysis + + align:start position:0% +time looking at the data the analysis + + + align:start position:0% +time looking at the data the analysis +suggested that some skills were + + align:start position:0% +suggested that some skills were + + + align:start position:0% +suggested that some skills were +undervalued and some skills were + + align:start position:0% +undervalued and some skills were + + + align:start position:0% +undervalued and some skills were +overvalued the key premise of the + + align:start position:0% +overvalued the key premise of the + + + align:start position:0% +overvalued the key premise of the +Oakland A's is that if they could detect + + align:start position:0% +Oakland A's is that if they could detect + + + align:start position:0% +Oakland A's is that if they could detect +the undervalued skills they could find + + align:start position:0% +the undervalued skills they could find + + + align:start position:0% +the undervalued skills they could find +players at a bargain + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/WsEPhUu8kKU.txt b/WsEPhUu8kKU.txt new file mode 100644 index 0000000000000000000000000000000000000000..5ae5a63c76c179895d7aceabc0aa4f6b53dbb442 --- /dev/null +++ b/WsEPhUu8kKU.txt @@ -0,0 +1,8371 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit mitop courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu we make a transition now to + + align:start position:0% +ocw.mit.edu we make a transition now to + + + align:start position:0% +ocw.mit.edu we make a transition now to +the final segment of our course in which + + align:start position:0% +the final segment of our course in which + + + align:start position:0% +the final segment of our course in which +we uh and and and this transition always + + align:start position:0% +we uh and and and this transition always + + + align:start position:0% +we uh and and and this transition always +induces uh a a kind of guilt in me a + + align:start position:0% +induces uh a a kind of guilt in me a + + + align:start position:0% +induces uh a a kind of guilt in me a +kind of deep ambivalence and + + align:start position:0% +kind of deep ambivalence and + + + align:start position:0% +kind of deep ambivalence and +disappointment and awareness of the + + align:start position:0% +disappointment and awareness of the + + + align:start position:0% +disappointment and awareness of the +simplifications and reductions that are + + align:start position:0% +simplifications and reductions that are + + + align:start position:0% +simplifications and reductions that are +embedded in all syllabi and in all + + align:start position:0% +embedded in all syllabi and in all + + + align:start position:0% +embedded in all syllabi and in all +curricula and it's a good opportunity + + align:start position:0% +curricula and it's a good opportunity + + + align:start position:0% +curricula and it's a good opportunity +for me to remind you that even the + + align:start position:0% +for me to remind you that even the + + + align:start position:0% +for me to remind you that even the +primary emphasis of our course which is + + align:start position:0% +primary emphasis of our course which is + + + align:start position:0% +primary emphasis of our course which is +on certain forms of American Film is + + align:start position:0% +on certain forms of American Film is + + + align:start position:0% +on certain forms of American Film is +itself highly selective and simplified + + align:start position:0% +itself highly selective and simplified + + + align:start position:0% +itself highly selective and simplified +and reductive as you as told you they + + align:start position:0% +and reductive as you as told you they + + + align:start position:0% +and reductive as you as told you they +were in the Hollywood System they were + + align:start position:0% +were in the Hollywood System they were + + + align:start position:0% +were in the Hollywood System they were +making 500 films a year think of the + + align:start position:0% +making 500 films a year think of the + + + align:start position:0% +making 500 films a year think of the +small number we've actually seen right + + align:start position:0% +small number we've actually seen right + + + align:start position:0% +small number we've actually seen right +it's the tinest sampling of what's + + align:start position:0% +it's the tinest sampling of what's + + + align:start position:0% +it's the tinest sampling of what's +actually available and what I've tried + + align:start position:0% +actually available and what I've tried + + + align:start position:0% +actually available and what I've tried +to do is give you a kind of taste of + + align:start position:0% +to do is give you a kind of taste of + + + align:start position:0% +to do is give you a kind of taste of +what that uh U uh phenomenon of the + + align:start position:0% +what that uh U uh phenomenon of the + + + align:start position:0% +what that uh U uh phenomenon of the +Hollywood film was like without trying + + align:start position:0% +Hollywood film was like without trying + + + align:start position:0% +Hollywood film was like without trying +to pretend at all that I was coming + + align:start position:0% +to pretend at all that I was coming + + + align:start position:0% +to pretend at all that I was coming +anything close to not not just couldn't + + align:start position:0% +anything close to not not just couldn't + + + align:start position:0% +anything close to not not just couldn't +be exhaustive we couldn't even be uh uh + + align:start position:0% +be exhaustive we couldn't even be uh uh + + + align:start position:0% +be exhaustive we couldn't even be uh uh +extensive or or mildly serious ious + + align:start position:0% +extensive or or mildly serious ious + + + align:start position:0% +extensive or or mildly serious ious +about about trying to do justice to the + + align:start position:0% +about about trying to do justice to the + + + align:start position:0% +about about trying to do justice to the +complexity of that body of material uh + + align:start position:0% +complexity of that body of material uh + + + align:start position:0% +complexity of that body of material uh +and that's even truer of course in this + + align:start position:0% +and that's even truer of course in this + + + align:start position:0% +and that's even truer of course in this +moment uh in this Final in these final + + align:start position:0% +moment uh in this Final in these final + + + align:start position:0% +moment uh in this Final in these final +moments of the course where I try to do + + align:start position:0% +moments of the course where I try to do + + + align:start position:0% +moments of the course where I try to do +sort of a a brief acknowledgement of the + + align:start position:0% +sort of a a brief acknowledgement of the + + + align:start position:0% +sort of a a brief acknowledgement of the +fact that there are profound and + + align:start position:0% +fact that there are profound and + + + align:start position:0% +fact that there are profound and +Powerful traditions of Cinema outside + + align:start position:0% +Powerful traditions of Cinema outside + + + align:start position:0% +Powerful traditions of Cinema outside +the United States in fact some more + + align:start position:0% +the United States in fact some more + + + align:start position:0% +the United States in fact some more +profound or at least as profound and + + align:start position:0% +profound or at least as profound and + + + align:start position:0% +profound or at least as profound and +some more powerful on many people would + + align:start position:0% +some more powerful on many people would + + + align:start position:0% +some more powerful on many people would +say than than the achievement of + + align:start position:0% +say than than the achievement of + + + align:start position:0% +say than than the achievement of +American Cinema the achievements of + + align:start position:0% +American Cinema the achievements of + + + align:start position:0% +American Cinema the achievements of +American Cinema and perhaps the + + align:start position:0% +American Cinema and perhaps the + + + align:start position:0% +American Cinema and perhaps the +strongest example of that the most + + align:start position:0% +strongest example of that the most + + + align:start position:0% +strongest example of that the most +dramatic example of that is French film + + align:start position:0% +dramatic example of that is French film + + + align:start position:0% +dramatic example of that is French film +it has a kind of parallel history at + + align:start position:0% +it has a kind of parallel history at + + + align:start position:0% +it has a kind of parallel history at +virtually every stage of the history of + + align:start position:0% +virtually every stage of the history of + + + align:start position:0% +virtually every stage of the history of +French of American Film you can find a + + align:start position:0% +French of American Film you can find a + + + align:start position:0% +French of American Film you can find a +kind of counterpart story in French film + + align:start position:0% +kind of counterpart story in French film + + + align:start position:0% +kind of counterpart story in French film +as if it's almost as it and in fact + + align:start position:0% +as if it's almost as it and in fact + + + align:start position:0% +as if it's almost as it and in fact +there have been historians who have + + align:start position:0% +there have been historians who have + + + align:start position:0% +there have been historians who have +tried to argue about the priority who + + align:start position:0% +tried to argue about the priority who + + + align:start position:0% +tried to argue about the priority who +invented film were were the French more + + align:start position:0% +invented film were were the French more + + + align:start position:0% +invented film were were the French more +advanced than the Americans uh who first + + align:start position:0% +advanced than the Americans uh who first + + + align:start position:0% +advanced than the Americans uh who first +developed forms of serial movies who + + align:start position:0% +developed forms of serial movies who + + + align:start position:0% +developed forms of serial movies who +first developed forms of of of of the of + + align:start position:0% +first developed forms of of of of the of + + + align:start position:0% +first developed forms of of of of the of +the chase of the comic chase film in the + + align:start position:0% +the chase of the comic chase film in the + + + align:start position:0% +the chase of the comic chase film in the +early silent era and so forth and and uh + + align:start position:0% +early silent era and so forth and and uh + + + align:start position:0% +early silent era and so forth and and uh +I think these arguments are not very + + align:start position:0% +I think these arguments are not very + + + align:start position:0% +I think these arguments are not very +helpful about priority but it is very + + align:start position:0% +helpful about priority but it is very + + + align:start position:0% +helpful about priority but it is very +important to remind you that the uh + + align:start position:0% +important to remind you that the uh + + + align:start position:0% +important to remind you that the uh +history of of of uh other National + + align:start position:0% +history of of of uh other National + + + align:start position:0% +history of of of uh other National +Cinemas and most especially the + + align:start position:0% +Cinemas and most especially the + + + align:start position:0% +Cinemas and most especially the +histories of the history of French + + align:start position:0% +histories of the history of French + + + align:start position:0% +histories of the history of French +Cinema has the same complexity Nuance + + align:start position:0% +Cinema has the same complexity Nuance + + + align:start position:0% +Cinema has the same complexity Nuance +detail that American that American film + + align:start position:0% +detail that American that American film + + + align:start position:0% +detail that American that American film +has we can speak and just let me very + + align:start position:0% +has we can speak and just let me very + + + align:start position:0% +has we can speak and just let me very +quickly remind you uh I I've asked I + + align:start position:0% +quickly remind you uh I I've asked I + + + align:start position:0% +quickly remind you uh I I've asked I +asked you to read a chapter from David + + align:start position:0% +asked you to read a chapter from David + + + align:start position:0% +asked you to read a chapter from David +Cook's history of narrative film that + + align:start position:0% +Cook's history of narrative film that + + + align:start position:0% +Cook's history of narrative film that +deals with the complex achievements of + + align:start position:0% +deals with the complex achievements of + + + align:start position:0% +deals with the complex achievements of +French film in both the silent and in + + align:start position:0% +French film in both the silent and in + + + align:start position:0% +French film in both the silent and in +the sound era and I hope you read those + + align:start position:0% +the sound era and I hope you read those + + + align:start position:0% +the sound era and I hope you read those +chapters and reread those chapters + + align:start position:0% +chapters and reread those chapters + + + align:start position:0% +chapters and reread those chapters +closely and think about them just as a + + align:start position:0% +closely and think about them just as a + + + align:start position:0% +closely and think about them just as a +reminder however uh we you know there + + align:start position:0% +reminder however uh we you know there + + + align:start position:0% +reminder however uh we you know there +are arguments just as just as Edison and + + align:start position:0% +are arguments just as just as Edison and + + + align:start position:0% +are arguments just as just as Edison and +and the um the uh earliest films that + + align:start position:0% +and the um the uh earliest films that + + + align:start position:0% +and the um the uh earliest films that +were made in the United States are + + align:start position:0% +were made in the United States are + + + align:start position:0% +were made in the United States are +associated with the Edison Company so + + align:start position:0% +associated with the Edison Company so + + + align:start position:0% +associated with the Edison Company so +the same kind of thing is true for the + + align:start position:0% +the same kind of thing is true for the + + + align:start position:0% +the same kind of thing is true for the +Lumiere films that were developed in the + + align:start position:0% +Lumiere films that were developed in the + + + align:start position:0% +Lumiere films that were developed in the +1890s in France and of course just as + + align:start position:0% +1890s in France and of course just as + + + align:start position:0% +1890s in France and of course just as +there were pioneering uh directors who + + align:start position:0% +there were pioneering uh directors who + + + align:start position:0% +there were pioneering uh directors who +explored and the nature of Cinema the + + align:start position:0% +explored and the nature of Cinema the + + + align:start position:0% +explored and the nature of Cinema the +possibilities of of this new of this new + + align:start position:0% +possibilities of of this new of this new + + + align:start position:0% +possibilities of of this new of this new +medium in the United States an identical + + align:start position:0% +medium in the United States an identical + + + align:start position:0% +medium in the United States an identical +uh activity was taking place in France + + align:start position:0% +uh activity was taking place in France + + + align:start position:0% +uh activity was taking place in France +and some of you of course know about the + + align:start position:0% +and some of you of course know about the + + + align:start position:0% +and some of you of course know about the +entral contribution of the uh early + + align:start position:0% +entral contribution of the uh early + + + align:start position:0% +entral contribution of the uh early +pioneering director meler uh um who cook + + align:start position:0% +pioneering director meler uh um who cook + + + align:start position:0% +pioneering director meler uh um who cook +talks extensive ly about him in in the + + align:start position:0% +talks extensive ly about him in in the + + + align:start position:0% +talks extensive ly about him in in the +chapter I asked you to read the the man + + align:start position:0% +chapter I asked you to read the the man + + + align:start position:0% +chapter I asked you to read the the man +who in effect invented the science + + align:start position:0% +who in effect invented the science + + + align:start position:0% +who in effect invented the science +fiction movie in the film a trip to the + + align:start position:0% +fiction movie in the film a trip to the + + + align:start position:0% +fiction movie in the film a trip to the +moon and did so many other uh uh uh + + align:start position:0% +moon and did so many other uh uh uh + + + align:start position:0% +moon and did so many other uh uh uh +early uh experiments with for with with + + align:start position:0% +early uh experiments with for with with + + + align:start position:0% +early uh experiments with for with with +combining uh uh the reality of film with + + align:start position:0% +combining uh uh the reality of film with + + + align:start position:0% +combining uh uh the reality of film with +certain forms of surrealist imagination + + align:start position:0% +certain forms of surrealist imagination + + + align:start position:0% +certain forms of surrealist imagination +the tradition of discourse about film in + + align:start position:0% +the tradition of discourse about film in + + + align:start position:0% +the tradition of discourse about film in +France probably is deeper and has a + + align:start position:0% +France probably is deeper and has a + + + align:start position:0% +France probably is deeper and has a +longer life than in any other society + + align:start position:0% +longer life than in any other society + + + align:start position:0% +longer life than in any other society +and many people would say that along + + align:start position:0% +and many people would say that along + + + align:start position:0% +and many people would say that along +with eisenstein the great Russian + + align:start position:0% +with eisenstein the great Russian + + + align:start position:0% +with eisenstein the great Russian +director it's the French who elaborated + + align:start position:0% +director it's the French who elaborated + + + align:start position:0% +director it's the French who elaborated +the first systematic forms of film + + align:start position:0% +the first systematic forms of film + + + align:start position:0% +the first systematic forms of film +Theory uh and there were in the in the + + align:start position:0% +Theory uh and there were in the in the + + + align:start position:0% +Theory uh and there were in the in the +in the in the in the silent era and in + + align:start position:0% +in the in the in the silent era and in + + + align:start position:0% +in the in the in the silent era and in +the 20s uh uh in France uh a series of + + align:start position:0% +the 20s uh uh in France uh a series of + + + align:start position:0% +the 20s uh uh in France uh a series of +developments that encouraged a + + align:start position:0% +developments that encouraged a + + + align:start position:0% +developments that encouraged a +systematic kind of theoretical approach + + align:start position:0% +systematic kind of theoretical approach + + + align:start position:0% +systematic kind of theoretical approach +to film I won't mention names here or + + align:start position:0% +to film I won't mention names here or + + + align:start position:0% +to film I won't mention names here or +particular or particular uh uh theorists + + align:start position:0% +particular or particular uh uh theorists + + + align:start position:0% +particular or particular uh uh theorists +simply acknowledging the fact that that + + align:start position:0% +simply acknowledging the fact that that + + + align:start position:0% +simply acknowledging the fact that that +the French tradition of of discussion + + align:start position:0% +the French tradition of of discussion + + + align:start position:0% +the French tradition of of discussion +about film and in the creation of film + + align:start position:0% +about film and in the creation of film + + + align:start position:0% +about film and in the creation of film +is at least as rich as that of any other + + align:start position:0% +is at least as rich as that of any other + + + align:start position:0% +is at least as rich as that of any other +Society I say this because making uh um + + align:start position:0% +Society I say this because making uh um + + + align:start position:0% +Society I say this because making uh um +je Renoir stand for this whole Rich + + align:start position:0% +je Renoir stand for this whole Rich + + + align:start position:0% +je Renoir stand for this whole Rich +tradition is unfair even to so + + align:start position:0% +tradition is unfair even to so + + + align:start position:0% +tradition is unfair even to so +remarkable and influential director as + + align:start position:0% +remarkable and influential director as + + + align:start position:0% +remarkable and influential director as +Jean Renoir but having made that basic + + align:start position:0% +Jean Renoir but having made that basic + + + align:start position:0% +Jean Renoir but having made that basic +apology let me now make my transition to + + align:start position:0% +apology let me now make my transition to + + + align:start position:0% +apology let me now make my transition to +Renoir himself um um some of you will + + align:start position:0% +Renoir himself um um some of you will + + + align:start position:0% +Renoir himself um um some of you will +recognize of of uh renoir's name I hope + + align:start position:0% +recognize of of uh renoir's name I hope + + + align:start position:0% +recognize of of uh renoir's name I hope +he's the Second Son of the great U uh um + + align:start position:0% +he's the Second Son of the great U uh um + + + align:start position:0% +he's the Second Son of the great U uh um +impressionist painter August Renoir and + + align:start position:0% +impressionist painter August Renoir and + + + align:start position:0% +impressionist painter August Renoir and +in fact you can uh he was himself a uh a + + align:start position:0% +in fact you can uh he was himself a uh a + + + align:start position:0% +in fact you can uh he was himself a uh a +a subject of his father's paintings + + align:start position:0% +a subject of his father's paintings + + + align:start position:0% +a subject of his father's paintings +there's the there there's the young + + align:start position:0% +there's the there there's the young + + + align:start position:0% +there's the there there's the young +Renoir with blonde reddish hair as he + + align:start position:0% +Renoir with blonde reddish hair as he + + + align:start position:0% +Renoir with blonde reddish hair as he +appears in one of his father's paintings + + align:start position:0% +appears in one of his father's paintings + + + align:start position:0% +appears in one of his father's paintings +in the period 1895 to 1899 when the when + + align:start position:0% +in the period 1895 to 1899 when the when + + + align:start position:0% +in the period 1895 to 1899 when the when +young Jean appeared in a series of + + align:start position:0% +young Jean appeared in a series of + + + align:start position:0% +young Jean appeared in a series of +paintings in some of the p in some of + + align:start position:0% +paintings in some of the p in some of + + + align:start position:0% +paintings in some of the p in some of +the paintings his his tier is very + + align:start position:0% +the paintings his his tier is very + + + align:start position:0% +the paintings his his tier is very +ambiguous he looks not just that he has + + align:start position:0% +ambiguous he looks not just that he has + + + align:start position:0% +ambiguous he looks not just that he has +long hair but even seems dressed in a in + + align:start position:0% +long hair but even seems dressed in a in + + + align:start position:0% +long hair but even seems dressed in a in +a kind of girly way and he's sometimes + + align:start position:0% +a kind of girly way and he's sometimes + + + align:start position:0% +a kind of girly way and he's sometimes +mistaken for a girl when people look at + + align:start position:0% +mistaken for a girl when people look at + + + align:start position:0% +mistaken for a girl when people look at +the at the images but isn't it + + align:start position:0% +the at the images but isn't it + + + align:start position:0% +the at the images but isn't it +interesting that this great film artist + + align:start position:0% +interesting that this great film artist + + + align:start position:0% +interesting that this great film artist +is himself uh in a series of or is is + + align:start position:0% +is himself uh in a series of or is is + + + align:start position:0% +is himself uh in a series of or is is +already in a series of IM Immortal works + + align:start position:0% +already in a series of IM Immortal works + + + align:start position:0% +already in a series of IM Immortal works +of art created created by his father + + align:start position:0% +of art created created by his father + + + align:start position:0% +of art created created by his father +Jean Renoir grew up in a in in an + + align:start position:0% +Jean Renoir grew up in a in in an + + + align:start position:0% +Jean Renoir grew up in a in in an +atmosphere of avanguard uh almost + + align:start position:0% +atmosphere of avanguard uh almost + + + align:start position:0% +atmosphere of avanguard uh almost +avangard frenzy in a a uh uh many of the + + align:start position:0% +avangard frenzy in a a uh uh many of the + + + align:start position:0% +avangard frenzy in a a uh uh many of the +most distinguished artists and + + align:start position:0% +most distinguished artists and + + + align:start position:0% +most distinguished artists and +performers of the day were regulars in + + align:start position:0% +performers of the day were regulars in + + + align:start position:0% +performers of the day were regulars in +his household because his father by the + + align:start position:0% +his household because his father by the + + + align:start position:0% +his household because his father by the +he was born late in his very late in his + + align:start position:0% +he was born late in his very late in his + + + align:start position:0% +he was born late in his very late in his +father's life and his father was already + + align:start position:0% +father's life and his father was already + + + align:start position:0% +father's life and his father was already +a very famous painter by the time uh U + + align:start position:0% +a very famous painter by the time uh U + + + align:start position:0% +a very famous painter by the time uh U +Jean was born when he grew to adulthood + + align:start position:0% +Jean was born when he grew to adulthood + + + align:start position:0% +Jean was born when he grew to adulthood +he uh uh around the time of the first + + align:start position:0% +he uh uh around the time of the first + + + align:start position:0% +he uh uh around the time of the first +World War uh he served first in the + + align:start position:0% +World War uh he served first in the + + + align:start position:0% +World War uh he served first in the +Cavalry in 1913 uh very briefly uh um + + align:start position:0% +Cavalry in 1913 uh very briefly uh um + + + align:start position:0% +Cavalry in 1913 uh very briefly uh um +was actually injured he was kicked by an + + align:start position:0% +was actually injured he was kicked by an + + + align:start position:0% +was actually injured he was kicked by an +animal I think a horse or a mule kicked + + align:start position:0% +animal I think a horse or a mule kicked + + + align:start position:0% +animal I think a horse or a mule kicked +him and he was laid up then he + + align:start position:0% +him and he was laid up then he + + + align:start position:0% +him and he was laid up then he +reenlisted in the Infantry where he was + + align:start position:0% +reenlisted in the Infantry where he was + + + align:start position:0% +reenlisted in the Infantry where he was +wounded and he and finally this is very + + align:start position:0% +wounded and he and finally this is very + + + align:start position:0% +wounded and he and finally this is very +rare in the first World War uh uh he + + align:start position:0% +rare in the first World War uh uh he + + + align:start position:0% +rare in the first World War uh uh he +ended up serving also in the Air Force + + align:start position:0% +ended up serving also in the Air Force + + + align:start position:0% +ended up serving also in the Air Force +and he was briefly a pilot in the French + + align:start position:0% +and he was briefly a pilot in the French + + + align:start position:0% +and he was briefly a pilot in the French +Air Force so he served in all three + + align:start position:0% +Air Force so he served in all three + + + align:start position:0% +Air Force so he served in all three +branches of the + + align:start position:0% + + + + align:start position:0% + +French first world war and the film + + align:start position:0% +French first world war and the film + + + align:start position:0% +French first world war and the film +you're going to see tonight The Great + + align:start position:0% +you're going to see tonight The Great + + + align:start position:0% +you're going to see tonight The Great +Masterpiece so such the great + + align:start position:0% +Masterpiece so such the great + + + align:start position:0% +Masterpiece so such the great +influential deeply influential film + + align:start position:0% +influential deeply influential film + + + align:start position:0% +influential deeply influential film +Grand Illusion is a war film of a + + align:start position:0% +Grand Illusion is a war film of a + + + align:start position:0% +Grand Illusion is a war film of a +certain Renoir sort as you'll see this + + align:start position:0% +certain Renoir sort as you'll see this + + + align:start position:0% +certain Renoir sort as you'll see this +evening um uh + + align:start position:0% +evening um uh + + + align:start position:0% +evening um uh +he uh was he also served briefly uh in + + align:start position:0% +he uh was he also served briefly uh in + + + align:start position:0% +he uh was he also served briefly uh in +as a prisoner of war during the uh first + + align:start position:0% +as a prisoner of war during the uh first + + + align:start position:0% +as a prisoner of war during the uh first +world war and and uh that experience of + + align:start position:0% +world war and and uh that experience of + + + align:start position:0% +world war and and uh that experience of +course in some degree in in some Central + + align:start position:0% +course in some degree in in some Central + + + align:start position:0% +course in some degree in in some Central +Way informs the story and the experience + + align:start position:0% +Way informs the story and the experience + + + align:start position:0% +Way informs the story and the experience +of grand delusion which is also a story + + align:start position:0% +of grand delusion which is also a story + + + align:start position:0% +of grand delusion which is also a story +about a film about prisoners of War + + align:start position:0% +about a film about prisoners of War + + + align:start position:0% +about a film about prisoners of War +during wartime + + align:start position:0% + + + + align:start position:0% + +uh you can get some sense of of do we + + align:start position:0% +uh you can get some sense of of do we + + + align:start position:0% +uh you can get some sense of of do we +have some pictures of of his of his + + align:start position:0% +have some pictures of of his of his + + + align:start position:0% +have some pictures of of his of his +father's paintings let me just get these + + align:start position:0% +father's paintings let me just get these + + + align:start position:0% +father's paintings let me just get these +are just of course among some of uh uh + + align:start position:0% +are just of course among some of uh uh + + + align:start position:0% +are just of course among some of uh uh +uh Renoir pe's most famous paintings I + + align:start position:0% +uh Renoir pe's most famous paintings I + + + align:start position:0% +uh Renoir pe's most famous paintings I +thought that it would be you would be + + align:start position:0% +thought that it would be you would be + + + align:start position:0% +thought that it would be you would be +interested to see them to get some sense + + align:start position:0% +interested to see them to get some sense + + + align:start position:0% +interested to see them to get some sense +of of of of uh uh to remind you of what + + align:start position:0% +of of of of uh uh to remind you of what + + + align:start position:0% +of of of of uh uh to remind you of what +of of of the importance of his father's + + align:start position:0% +of of of the importance of his father's + + + align:start position:0% +of of of the importance of his father's +art uh and of the the uh asking you and + + align:start position:0% +art uh and of the the uh asking you and + + + align:start position:0% +art uh and of the the uh asking you and +also as a way of encouraging you to + + align:start position:0% +also as a way of encouraging you to + + + align:start position:0% +also as a way of encouraging you to +imagine what the impact might have been + + align:start position:0% +imagine what the impact might have been + + + align:start position:0% +imagine what the impact might have been +on the Young on the young boy to have + + align:start position:0% +on the Young on the young boy to have + + + align:start position:0% +on the Young on the young boy to have +grown up in an environment in an + + align:start position:0% +grown up in an environment in an + + + align:start position:0% +grown up in an environment in an +environment like this I don't know that + + align:start position:0% +environment like this I don't know that + + + align:start position:0% +environment like this I don't know that +that does look like Jean maybe it is + + align:start position:0% +that does look like Jean maybe it is + + + align:start position:0% +that does look like Jean maybe it is +another picture of Jean uh um he had + + align:start position:0% +another picture of Jean uh um he had + + + align:start position:0% +another picture of Jean uh um he had +kind of a jowly face and that may be + + align:start position:0% +kind of a jowly face and that may be + + + align:start position:0% +kind of a jowly face and that may be +among the oldest images of him + + align:start position:0% +among the oldest images of him + + + align:start position:0% +among the oldest images of him +that him at the oldest age that his + + align:start position:0% +that him at the oldest age that his + + + align:start position:0% +that him at the oldest age that his +father painted him + + align:start position:0% +father painted him + + + align:start position:0% +father painted him +um he + + align:start position:0% +um he + + + align:start position:0% +um he +um worked on his first after he emerged + + align:start position:0% +um worked on his first after he emerged + + + align:start position:0% +um worked on his first after he emerged +from the first World War War he he had + + align:start position:0% +from the first World War War he he had + + + align:start position:0% +from the first World War War he he had +uh uh conflicting Ambitions but he moved + + align:start position:0% +uh uh conflicting Ambitions but he moved + + + align:start position:0% +uh uh conflicting Ambitions but he moved +into into film uh fairly soon he wrote a + + align:start position:0% +into into film uh fairly soon he wrote a + + + align:start position:0% +into into film uh fairly soon he wrote a +script in + + align:start position:0% +script in + + + align:start position:0% +script in +1924 uh he began to make uh uh his own + + align:start position:0% +1924 uh he began to make uh uh his own + + + align:start position:0% +1924 uh he began to make uh uh his own +movies around the same time I have a + + align:start position:0% +movies around the same time I have a + + + align:start position:0% +movies around the same time I have a +very brief list of some of his films + + align:start position:0% +very brief list of some of his films + + + align:start position:0% +very brief list of some of his films +would you put those up uh I want to talk + + align:start position:0% +would you put those up uh I want to talk + + + align:start position:0% +would you put those up uh I want to talk +very quickly about a couple of his films + + align:start position:0% +very quickly about a couple of his films + + + align:start position:0% +very quickly about a couple of his films +and then turn to certain other uh + + align:start position:0% +and then turn to certain other uh + + + align:start position:0% +and then turn to certain other uh +important matters but the most important + + align:start position:0% +important matters but the most important + + + align:start position:0% +important matters but the most important +thing to say about renoir's gen renoir's + + align:start position:0% +thing to say about renoir's gen renoir's + + + align:start position:0% +thing to say about renoir's gen renoir's +career is that like some important + + align:start position:0% +career is that like some important + + + align:start position:0% +career is that like some important +American directors his career spans both + + align:start position:0% +American directors his career spans both + + + align:start position:0% +American directors his career spans both +the silent and the sound era uh uh and + + align:start position:0% +the silent and the sound era uh uh and + + + align:start position:0% +the silent and the sound era uh uh and +he made some significant experimental + + align:start position:0% +he made some significant experimental + + + align:start position:0% +he made some significant experimental +silent films of which um uh the most + + align:start position:0% +silent films of which um uh the most + + + align:start position:0% +silent films of which um uh the most +wellknown in in terms of experiment is + + align:start position:0% +wellknown in in terms of experiment is + + + align:start position:0% +wellknown in in terms of experiment is +the film The Little Match Girl based on + + align:start position:0% +the film The Little Match Girl based on + + + align:start position:0% +the film The Little Match Girl based on +a Hans Christian Anderson story and it + + align:start position:0% +a Hans Christian Anderson story and it + + + align:start position:0% +a Hans Christian Anderson story and it +uses certain kinds of surreal imagery + + align:start position:0% +uses certain kinds of surreal imagery + + + align:start position:0% +uses certain kinds of surreal imagery +that's very surprising especially in a + + align:start position:0% +that's very surprising especially in a + + + align:start position:0% +that's very surprising especially in a +in a silent film and uh and I I + + align:start position:0% +in a silent film and uh and I I + + + align:start position:0% +in a silent film and uh and I I +mentioned + + align:start position:0% +mentioned + + + align:start position:0% +mentioned +the that he made a silent version of a + + align:start position:0% +the that he made a silent version of a + + + align:start position:0% +the that he made a silent version of a +novel by zolah Nana Nana as a way of + + align:start position:0% +novel by zolah Nana Nana as a way of + + + align:start position:0% +novel by zolah Nana Nana as a way of +simply also reminding you from a very + + align:start position:0% +simply also reminding you from a very + + + align:start position:0% +simply also reminding you from a very +early stage Renoir understood that the + + align:start position:0% +early stage Renoir understood that the + + + align:start position:0% +early stage Renoir understood that the +movies were were a form that could + + align:start position:0% +movies were were a form that could + + + align:start position:0% +movies were were a form that could +sustain the most ambitious kind of + + align:start position:0% +sustain the most ambitious kind of + + + align:start position:0% +sustain the most ambitious kind of +artistic act um uh uh aims and and uh um + + align:start position:0% +artistic act um uh uh aims and and uh um + + + align:start position:0% +artistic act um uh uh aims and and uh um +in uh it's a measure of his sense of + + align:start position:0% +in uh it's a measure of his sense of + + + align:start position:0% +in uh it's a measure of his sense of +that that he would adapt even during the + + align:start position:0% +that that he would adapt even during the + + + align:start position:0% +that that he would adapt even during the +silent era a film by one of France by + + align:start position:0% +silent era a film by one of France by + + + align:start position:0% +silent era a film by one of France by +one by a classic French author um but + + align:start position:0% +one by a classic French author um but + + + align:start position:0% +one by a classic French author um but +his most but his really significant work + + align:start position:0% +his most but his really significant work + + + align:start position:0% +his most but his really significant work +begins in the sound era and in what's + + align:start position:0% +begins in the sound era and in what's + + + align:start position:0% +begins in the sound era and in what's +often called his French period and the + + align:start position:0% +often called his French period and the + + + align:start position:0% +often called his French period and the +films I've listed between 31 and 39 not + + align:start position:0% +films I've listed between 31 and 39 not + + + align:start position:0% +films I've listed between 31 and 39 not +a complete list of his films this is a + + align:start position:0% +a complete list of his films this is a + + + align:start position:0% +a complete list of his films this is a +very selected list but it's a list of + + align:start position:0% +very selected list but it's a list of + + + align:start position:0% +very selected list but it's a list of +his Mo of some of his most significant + + align:start position:0% +his Mo of some of his most significant + + + align:start position:0% +his Mo of some of his most significant +all of his most among his most + + align:start position:0% +all of his most among his most + + + align:start position:0% +all of his most among his most +significant films for sure no really + + align:start position:0% +significant films for sure no really + + + align:start position:0% +significant films for sure no really +important title is missing although + + align:start position:0% +important title is missing although + + + align:start position:0% +important title is missing although +there are many other interesting films + + align:start position:0% +there are many other interesting films + + + align:start position:0% +there are many other interesting films +that he made and it's the period between + + align:start position:0% +that he made and it's the period between + + + align:start position:0% +that he made and it's the period between +31 and 39 he left France after rules of + + align:start position:0% +31 and 39 he left France after rules of + + + align:start position:0% +31 and 39 he left France after rules of +the game while when the second world war + + align:start position:0% +the game while when the second world war + + + align:start position:0% +the game while when the second world war +was imminent came to the United States + + align:start position:0% +was imminent came to the United States + + + align:start position:0% +was imminent came to the United States +the films of the 40s that I've listed + + align:start position:0% +the films of the 40s that I've listed + + + align:start position:0% +the films of the 40s that I've listed +there were made in Hollywood and he was + + align:start position:0% +there were made in Hollywood and he was + + + align:start position:0% +there were made in Hollywood and he was +very welcomed in Hollywood and there are + + align:start position:0% +very welcomed in Hollywood and there are + + + align:start position:0% +very welcomed in Hollywood and there are +people who uh film Scholars who are + + align:start position:0% +people who uh film Scholars who are + + + align:start position:0% +people who uh film Scholars who are +great fans of these three films these + + align:start position:0% +great fans of these three films these + + + align:start position:0% +great fans of these three films these +three titles that he made in the United + + align:start position:0% +three titles that he made in the United + + + align:start position:0% +three titles that he made in the United +States uh then he left the United States + + align:start position:0% +States uh then he left the United States + + + align:start position:0% +States uh then he left the United States +the the film The River which many uh uh + + align:start position:0% +the the film The River which many uh uh + + + align:start position:0% +the the film The River which many uh uh +Renoir Buffs love as much as his primary + + align:start position:0% +Renoir Buffs love as much as his primary + + + align:start position:0% +Renoir Buffs love as much as his primary +films although I find it a much slower + + align:start position:0% +films although I find it a much slower + + + align:start position:0% +films although I find it a much slower +less powerful film although visually + + align:start position:0% +less powerful film although visually + + + align:start position:0% +less powerful film although visually +incredibly beautiful it's set in India + + align:start position:0% +incredibly beautiful it's set in India + + + align:start position:0% +incredibly beautiful it's set in India +and and the river is the Ganges uh and + + align:start position:0% +and and the river is the Ganges uh and + + + align:start position:0% +and and the river is the Ganges uh and +it's a very very remarkable uh uh + + align:start position:0% +it's a very very remarkable uh uh + + + align:start position:0% +it's a very very remarkable uh uh +meditation on the power of place uh in + + align:start position:0% +meditation on the power of place uh in + + + align:start position:0% +meditation on the power of place uh in +in societ but his Central achievement + + align:start position:0% +in societ but his Central achievement + + + align:start position:0% +in societ but his Central achievement +are the films of his French period uh + + align:start position:0% +are the films of his French period uh + + + align:start position:0% +are the films of his French period uh +running through the 1930s uh and I I + + align:start position:0% +running through the 1930s uh and I I + + + align:start position:0% +running through the 1930s uh and I I +want to say a word about some of these + + align:start position:0% +want to say a word about some of these + + + align:start position:0% +want to say a word about some of these +uh uh um one of them lashen uh Stars + + align:start position:0% +uh uh um one of them lashen uh Stars + + + align:start position:0% +uh uh um one of them lashen uh Stars +the same character who stars in budoo + + align:start position:0% +the same character who stars in budoo + + + align:start position:0% +the same character who stars in budoo +save from drowning and you're going to + + align:start position:0% +save from drowning and you're going to + + + align:start position:0% +save from drowning and you're going to +see a clip from that uh uh U film in a + + align:start position:0% +see a clip from that uh uh U film in a + + + align:start position:0% +see a clip from that uh uh U film in a +moment uh uh Michelle Simone uh and uh + + align:start position:0% +moment uh uh Michelle Simone uh and uh + + + align:start position:0% +moment uh uh Michelle Simone uh and uh +lashen announced a kind of complexity + + align:start position:0% +lashen announced a kind of complexity + + + align:start position:0% +lashen announced a kind of complexity +and ambitiousness in in uh uh renoir's + + align:start position:0% +and ambitiousness in in uh uh renoir's + + + align:start position:0% +and ambitiousness in in uh uh renoir's +work that that uh was deeply significant + + align:start position:0% +work that that uh was deeply significant + + + align:start position:0% +work that that uh was deeply significant +it it had a kind of moral or political + + align:start position:0% +it it had a kind of moral or political + + + align:start position:0% +it it had a kind of moral or political +uh uh claim it was a film uh set in the + + align:start position:0% +uh uh claim it was a film uh set in the + + + align:start position:0% +uh uh claim it was a film uh set in the +in the slums and it was about a uh a an + + align:start position:0% +in the slums and it was about a uh a an + + + align:start position:0% +in the slums and it was about a uh a an +aborted or an abortive or tragic love + + align:start position:0% +aborted or an abortive or tragic love + + + align:start position:0% +aborted or an abortive or tragic love +affair between a working a working man + + align:start position:0% +affair between a working a working man + + + align:start position:0% +affair between a working a working man +played by a proletarian played by + + align:start position:0% +played by a proletarian played by + + + align:start position:0% +played by a proletarian played by +Michelle Simone and a prostitute who is + + align:start position:0% +Michelle Simone and a prostitute who is + + + align:start position:0% +Michelle Simone and a prostitute who is +unkind to him at the end and and and and + + align:start position:0% +unkind to him at the end and and and and + + + align:start position:0% +unkind to him at the end and and and and +uh throws him over at the end uh and uh + + align:start position:0% +uh throws him over at the end uh and uh + + + align:start position:0% +uh throws him over at the end uh and uh +the the film's in the film's interest in + + align:start position:0% +the the film's in the film's interest in + + + align:start position:0% +the the film's in the film's interest in +the life of the low in the lives and + + align:start position:0% +the life of the low in the lives and + + + align:start position:0% +the life of the low in the lives and +circumstances of the lower social orders + + align:start position:0% +circumstances of the lower social orders + + + align:start position:0% +circumstances of the lower social orders +was a was was especially significant + + align:start position:0% +was a was was especially significant + + + align:start position:0% +was a was was especially significant +significant and Michelle Simone's uh + + align:start position:0% +significant and Michelle Simone's uh + + + align:start position:0% +significant and Michelle Simone's uh +mely powerful uh uh uh physical + + align:start position:0% +mely powerful uh uh uh physical + + + align:start position:0% +mely powerful uh uh uh physical +performance uh was uh also memorable and + + align:start position:0% +performance uh was uh also memorable and + + + align:start position:0% +performance uh was uh also memorable and +you'll see a version of that in a moment + + align:start position:0% +you'll see a version of that in a moment + + + align:start position:0% +you'll see a version of that in a moment +in in the following year he made what + + align:start position:0% +in in the following year he made what + + + align:start position:0% +in in the following year he made what +many people call his first Great + + align:start position:0% +many people call his first Great + + + align:start position:0% +many people call his first Great +Masterpiece a film called budoo save + + align:start position:0% +Masterpiece a film called budoo save + + + align:start position:0% +Masterpiece a film called budoo save +from drowning it's the French title is + + align:start position:0% +from drowning it's the French title is + + + align:start position:0% +from drowning it's the French title is +budo so Deo saved from the waters Deo + + align:start position:0% +budo so Deo saved from the waters Deo + + + align:start position:0% +budo so Deo saved from the waters Deo +the the waters plural uh and the French + + align:start position:0% +the the waters plural uh and the French + + + align:start position:0% +the the waters plural uh and the French +title is a little better as I'll try to + + align:start position:0% +title is a little better as I'll try to + + + align:start position:0% +title is a little better as I'll try to +say in a moment U uh he made I mentioned + + align:start position:0% +say in a moment U uh he made I mentioned + + + align:start position:0% +say in a moment U uh he made I mentioned +The Madame Bou partly again to show you + + align:start position:0% +The Madame Bou partly again to show you + + + align:start position:0% +The Madame Bou partly again to show you +something about his ambition he's trying + + align:start position:0% +something about his ambition he's trying + + + align:start position:0% +something about his ambition he's trying +to say in effect look the film is an + + align:start position:0% +to say in effect look the film is an + + + align:start position:0% +to say in effect look the film is an +equivalent art form to the great novels + + align:start position:0% +equivalent art form to the great novels + + + align:start position:0% +equivalent art form to the great novels +of our past uh uh in 1935 he made a film + + align:start position:0% +of our past uh uh in 1935 he made a film + + + align:start position:0% +of our past uh uh in 1935 he made a film +that many uh identify as a + + align:start position:0% +that many uh identify as a + + + align:start position:0% +that many uh identify as a +forerunner of of uh Italian neorealism + + align:start position:0% +forerunner of of uh Italian neorealism + + + align:start position:0% +forerunner of of uh Italian neorealism +the movement we'll be studying next week + + align:start position:0% +the movement we'll be studying next week + + + align:start position:0% +the movement we'll be studying next week +and I talk a bit about Tony in next + + align:start position:0% +and I talk a bit about Tony in next + + + align:start position:0% +and I talk a bit about Tony in next +week's lecture uh it's a film uh uh very + + align:start position:0% +week's lecture uh it's a film uh uh very + + + align:start position:0% +week's lecture uh it's a film uh uh very +experimental in certain ways it uses a + + align:start position:0% +experimental in certain ways it uses a + + + align:start position:0% +experimental in certain ways it uses a +lot of nonprofessional actors uh um uh + + align:start position:0% +lot of nonprofessional actors uh um uh + + + align:start position:0% +lot of nonprofessional actors uh um uh +and and again it's + + align:start position:0% +and and again it's + + + align:start position:0% +and and again it's +about the circumstances of of the + + align:start position:0% +about the circumstances of of the + + + align:start position:0% +about the circumstances of of the +working class in some way it's about + + align:start position:0% +working class in some way it's about + + + align:start position:0% +working class in some way it's about +it's about uh um French Quarry worker + + align:start position:0% +it's about uh um French Quarry worker + + + align:start position:0% +it's about uh um French Quarry worker +workers who are treated with a kind of + + align:start position:0% +workers who are treated with a kind of + + + align:start position:0% +workers who are treated with a kind of +with with a kind of with a kind of + + align:start position:0% +with with a kind of with a kind of + + + align:start position:0% +with with a kind of with a kind of +clarity and and attentiveness that that + + align:start position:0% +clarity and and attentiveness that that + + + align:start position:0% +clarity and and attentiveness that that +uh previous films had had not had had + + align:start position:0% +uh previous films had had not had had + + + align:start position:0% +uh previous films had had not had had +rarely granted to members of the uh not + + align:start position:0% +rarely granted to members of the uh not + + + align:start position:0% +rarely granted to members of the uh not +only the lower social orders but here + + align:start position:0% +only the lower social orders but here + + + align:start position:0% +only the lower social orders but here +immigrants not even not not not even + + align:start position:0% +immigrants not even not not not even + + + align:start position:0% +immigrants not even not not not even +natives uh his two masterpieces come uh + + align:start position:0% +natives uh his two masterpieces come uh + + + align:start position:0% +natives uh his two masterpieces come uh +in 37 and 39 n again remember I've left + + align:start position:0% +in 37 and 39 n again remember I've left + + + align:start position:0% +in 37 and 39 n again remember I've left +out a number of titles here this is a + + align:start position:0% +out a number of titles here this is a + + + align:start position:0% +out a number of titles here this is a +selected list uh the film you'll see + + align:start position:0% +selected list uh the film you'll see + + + align:start position:0% +selected list uh the film you'll see +tonight Grand Illusion and uh what many + + align:start position:0% +tonight Grand Illusion and uh what many + + + align:start position:0% +tonight Grand Illusion and uh what many +people think of as his greatest film a + + align:start position:0% +people think of as his greatest film a + + + align:start position:0% +people think of as his greatest film a +deep complex satire on contemporary + + align:start position:0% +deep complex satire on contemporary + + + align:start position:0% +deep complex satire on contemporary +French life in the pre in just before + + align:start position:0% +French life in the pre in just before + + + align:start position:0% +French life in the pre in just before +the war called rules of the game the + + align:start position:0% +the war called rules of the game the + + + align:start position:0% +the war called rules of the game the +primary label that's attached to Jean + + align:start position:0% +primary label that's attached to Jean + + + align:start position:0% +primary label that's attached to Jean +renoir's work is that of poetic realism + + align:start position:0% +renoir's work is that of poetic realism + + + align:start position:0% +renoir's work is that of poetic realism +and it's a it's a way of trying to + + align:start position:0% +and it's a it's a way of trying to + + + align:start position:0% +and it's a it's a way of trying to +distinguish a form of movie making that + + align:start position:0% +distinguish a form of movie making that + + + align:start position:0% +distinguish a form of movie making that +emerges of which uh Renoir is the most + + align:start position:0% +emerges of which uh Renoir is the most + + + align:start position:0% +emerges of which uh Renoir is the most +dramatic and Powerful Exemplar but there + + align:start position:0% +dramatic and Powerful Exemplar but there + + + align:start position:0% +dramatic and Powerful Exemplar but there +were many other examples in in in in in + + align:start position:0% +were many other examples in in in in in + + + align:start position:0% +were many other examples in in in in in +uh in French Cinema and and it's worth + + align:start position:0% +uh in French Cinema and and it's worth + + + align:start position:0% +uh in French Cinema and and it's worth +talking a little bit about a t + + align:start position:0% +talking a little bit about a t + + + align:start position:0% +talking a little bit about a t +Forerunner to the tradition of poetic + + align:start position:0% +Forerunner to the tradition of poetic + + + align:start position:0% +Forerunner to the tradition of poetic +realism a director named Jean Vio who + + align:start position:0% +realism a director named Jean Vio who + + + align:start position:0% +realism a director named Jean Vio who +died tragically young as you can see + + align:start position:0% +died tragically young as you can see + + + align:start position:0% +died tragically young as you can see +from his dates who made uh uh the three + + align:start position:0% +from his dates who made uh uh the three + + + align:start position:0% +from his dates who made uh uh the three +films three titles I've listed there uh + + align:start position:0% +films three titles I've listed there uh + + + align:start position:0% +films three titles I've listed there uh +and these these films had an immense uh + + align:start position:0% +and these these films had an immense uh + + + align:start position:0% +and these these films had an immense uh +uh influence on later filmmakers uh zero + + align:start position:0% +uh influence on later filmmakers uh zero + + + align:start position:0% +uh influence on later filmmakers uh zero +for conduct is a is a a film set in a it + + align:start position:0% +for conduct is a is a a film set in a it + + + align:start position:0% +for conduct is a is a a film set in a it +has surreal elements and it's it's it's + + align:start position:0% +has surreal elements and it's it's it's + + + align:start position:0% +has surreal elements and it's it's it's +it's plot it's hard to follow but it + + align:start position:0% +it's plot it's hard to follow but it + + + align:start position:0% +it's plot it's hard to follow but it +essentially it tells the story of + + align:start position:0% +essentially it tells the story of + + + align:start position:0% +essentially it tells the story of +children going back to school it's a + + align:start position:0% +children going back to school it's a + + + align:start position:0% +children going back to school it's a +it's a it's a and following them once + + align:start position:0% +it's a it's a and following them once + + + align:start position:0% +it's a it's a and following them once +they get into a kind of boarding school + + align:start position:0% +they get into a kind of boarding school + + + align:start position:0% +they get into a kind of boarding school +and rebel against their house masters + + align:start position:0% +and rebel against their house masters + + + align:start position:0% +and rebel against their house masters +and the there's a sort of comic element + + align:start position:0% +and the there's a sort of comic element + + + align:start position:0% +and the there's a sort of comic element +in the film and there's also an element + + align:start position:0% +in the film and there's also an element + + + align:start position:0% +in the film and there's also an element +that might be called an Impulse toward + + align:start position:0% +that might be called an Impulse toward + + + align:start position:0% +that might be called an Impulse toward +lyric retardation by which I mean the + + align:start position:0% +lyric retardation by which I mean the + + + align:start position:0% +lyric retardation by which I mean the +the retarding is the retarding of the + + align:start position:0% +the retarding is the retarding of the + + + align:start position:0% +the retarding is the retarding of the +plot I don't mean mental right + + align:start position:0% +plot I don't mean mental right + + + align:start position:0% +plot I don't mean mental right +there's a kind of lyric impulse to + + align:start position:0% +there's a kind of lyric impulse to + + + align:start position:0% +there's a kind of lyric impulse to +celebrate what's going on right in front + + align:start position:0% +celebrate what's going on right in front + + + align:start position:0% +celebrate what's going on right in front +of you at the expense of the plot as if + + align:start position:0% +of you at the expense of the plot as if + + + align:start position:0% +of you at the expense of the plot as if +as if as if the story almost stops + + align:start position:0% +as if as if the story almost stops + + + align:start position:0% +as if as if the story almost stops +moving at a certain point while the + + align:start position:0% +moving at a certain point while the + + + align:start position:0% +moving at a certain point while the +camera and the and the and the and the + + align:start position:0% +camera and the and the and the and the + + + align:start position:0% +camera and the and the and the and the +uh well the camera itself sort of + + align:start position:0% +uh well the camera itself sort of + + + align:start position:0% +uh well the camera itself sort of +indulges in in a in in in in witnessing + + align:start position:0% +indulges in in a in in in in witnessing + + + align:start position:0% +indulges in in a in in in in witnessing +a spectacle so intrinsically interesting + + align:start position:0% +a spectacle so intrinsically interesting + + + align:start position:0% +a spectacle so intrinsically interesting +in itself that it seems to lose interest + + align:start position:0% +in itself that it seems to lose interest + + + align:start position:0% +in itself that it seems to lose interest +in the ongoing story so there's this + + align:start position:0% +in the ongoing story so there's this + + + align:start position:0% +in the ongoing story so there's this +tension in vigo's films from the very + + align:start position:0% +tension in vigo's films from the very + + + align:start position:0% +tension in vigo's films from the very +beginning in what some Scholars have + + align:start position:0% +beginning in what some Scholars have + + + align:start position:0% +beginning in what some Scholars have +seen a tension between denotation and + + align:start position:0% +seen a tension between denotation and + + + align:start position:0% +seen a tension between denotation and +connotation between the denotation being + + align:start position:0% +connotation between the denotation being + + + align:start position:0% +connotation between the denotation being +the simple realism the ongoing story + + align:start position:0% +the simple realism the ongoing story + + + align:start position:0% +the simple realism the ongoing story +right and the connotation being the + + align:start position:0% +right and the connotation being the + + + align:start position:0% +right and the connotation being the +poetic or lyrical impulse of the film to + + align:start position:0% +poetic or lyrical impulse of the film to + + + align:start position:0% +poetic or lyrical impulse of the film to +sort of Celebrate life in its complexity + + align:start position:0% +sort of Celebrate life in its complexity + + + align:start position:0% +sort of Celebrate life in its complexity +and its Nuance without any interference + + align:start position:0% +and its Nuance without any interference + + + align:start position:0% +and its Nuance without any interference +from the demand that you follow a story + + align:start position:0% +from the demand that you follow a story + + + align:start position:0% +from the demand that you follow a story +and this tension uh is is a fundamental + + align:start position:0% +and this tension uh is is a fundamental + + + align:start position:0% +and this tension uh is is a fundamental +element not only in in uh uh po realism + + align:start position:0% +element not only in in uh uh po realism + + + align:start position:0% +element not only in in uh uh po realism +but as you'll see in the Italian form of + + align:start position:0% +but as you'll see in the Italian form of + + + align:start position:0% +but as you'll see in the Italian form of +this called neorealism that emerges out + + align:start position:0% +this called neorealism that emerges out + + + align:start position:0% +this called neorealism that emerges out +of it and is somewhat of a grittier and + + align:start position:0% +of it and is somewhat of a grittier and + + + align:start position:0% +of it and is somewhat of a grittier and +more historically um um uh politically + + align:start position:0% +more historically um um uh politically + + + align:start position:0% +more historically um um uh politically +engaged kind of kind of uh drama even + + align:start position:0% +engaged kind of kind of uh drama even + + + align:start position:0% +engaged kind of kind of uh drama even +kind of kind of film even though it's a + + align:start position:0% +kind of kind of film even though it's a + + + align:start position:0% +kind of kind of film even though it's a +direct outgrowth of the kind of thing + + align:start position:0% +direct outgrowth of the kind of thing + + + align:start position:0% +direct outgrowth of the kind of thing +we're saying about poetic realism and in + + align:start position:0% +we're saying about poetic realism and in + + + align:start position:0% +we're saying about poetic realism and in +both forms in both kinds of film there + + align:start position:0% +both forms in both kinds of film there + + + align:start position:0% +both forms in both kinds of film there +is this retarding impulse this lyric + + align:start position:0% +is this retarding impulse this lyric + + + align:start position:0% +is this retarding impulse this lyric +impulse in which in which the story's + + align:start position:0% +impulse in which in which the story's + + + align:start position:0% +impulse in which in which the story's +desire to get on with itself is + + align:start position:0% +desire to get on with itself is + + + align:start position:0% +desire to get on with itself is +sometimes in conflict with the Cam's + + align:start position:0% +sometimes in conflict with the Cam's + + + align:start position:0% +sometimes in conflict with the Cam's +desire to look at what it sees to to to + + align:start position:0% +desire to look at what it sees to to to + + + align:start position:0% +desire to look at what it sees to to to +to to to Riel in what it in what it + + align:start position:0% +to to to Riel in what it in what it + + + align:start position:0% +to to to Riel in what it in what it +wants to look at um and uh uh um so so + + align:start position:0% +wants to look at um and uh uh um so so + + + align:start position:0% +wants to look at um and uh uh um so so +Jean Vigo uh partly indeed because of + + align:start position:0% +Jean Vigo uh partly indeed because of + + + align:start position:0% +Jean Vigo uh partly indeed because of +his tragic life short life uh and and + + align:start position:0% +his tragic life short life uh and and + + + align:start position:0% +his tragic life short life uh and and +partly because of he was the son of an + + align:start position:0% +partly because of he was the son of an + + + align:start position:0% +partly because of he was the son of an +anarchist of a political Anarchist a + + align:start position:0% +anarchist of a political Anarchist a + + + align:start position:0% +anarchist of a political Anarchist a +serious Anarchist who who wrote about + + align:start position:0% +serious Anarchist who who wrote about + + + align:start position:0% +serious Anarchist who who wrote about +theories of an of of Anar anarchism as a + + align:start position:0% +theories of an of of Anar anarchism as a + + + align:start position:0% +theories of an of of Anar anarchism as a +political movement and he himself was + + align:start position:0% +political movement and he himself was + + + align:start position:0% +political movement and he himself was +very very hostile to Authority Jean Vio + + align:start position:0% +very very hostile to Authority Jean Vio + + + align:start position:0% +very very hostile to Authority Jean Vio +and his films animate a kind of uh + + align:start position:0% +and his films animate a kind of uh + + + align:start position:0% +and his films animate a kind of uh +anarchic + + align:start position:0% + + + + align:start position:0% + +antiestablishmentarianism uh that is + + align:start position:0% +antiestablishmentarianism uh that is + + + align:start position:0% +antiestablishmentarianism uh that is +that is that is very distinctive he's + + align:start position:0% +that is that is very distinctive he's + + + align:start position:0% +that is that is very distinctive he's +almost always on the side of the of the + + align:start position:0% +almost always on the side of the of the + + + align:start position:0% +almost always on the side of the of the +weak and the + + align:start position:0% +weak and the + + + align:start position:0% +weak and the +powerless um let me say a few words + + align:start position:0% +powerless um let me say a few words + + + align:start position:0% +powerless um let me say a few words +about the key what we might call the key + + align:start position:0% +about the key what we might call the key + + + align:start position:0% +about the key what we might call the key +features of neorealism one of the most + + align:start position:0% +features of neorealism one of the most + + + align:start position:0% +features of neorealism one of the most +fundamental elements of neorealism is + + align:start position:0% +fundamental elements of neorealism is + + + align:start position:0% +fundamental elements of neorealism is +what could be called a Misa nonsense + + align:start position:0% +what could be called a Misa nonsense + + + align:start position:0% +what could be called a Misa nonsense +style that is to say it's committed to + + align:start position:0% +style that is to say it's committed to + + + align:start position:0% +style that is to say it's committed to +long takes the poetic realism is + + align:start position:0% +long takes the poetic realism is + + + align:start position:0% +long takes the poetic realism is +interested in the external world and in + + align:start position:0% +interested in the external world and in + + + align:start position:0% +interested in the external world and in +the relation between characters and the + + align:start position:0% +the relation between characters and the + + + align:start position:0% +the relation between characters and the +outer world and and and although it will + + align:start position:0% +outer world and and and although it will + + + align:start position:0% +outer world and and and although it will +use abrupt cuts of various kinds it + + align:start position:0% +use abrupt cuts of various kinds it + + + align:start position:0% +use abrupt cuts of various kinds it +won't do so at the expense of your + + align:start position:0% +won't do so at the expense of your + + + align:start position:0% +won't do so at the expense of your +experience of the outer World it wants + + align:start position:0% +experience of the outer World it wants + + + align:start position:0% +experience of the outer World it wants +the audience to take in uh what it sees + + align:start position:0% +the audience to take in uh what it sees + + + align:start position:0% +the audience to take in uh what it sees +and to make judgments about it it + + align:start position:0% +and to make judgments about it it + + + align:start position:0% +and to make judgments about it it +doesn't try to in the in the way that + + align:start position:0% +doesn't try to in the in the way that + + + align:start position:0% +doesn't try to in the in the way that +certain other kinds of styles might do + + align:start position:0% +certain other kinds of styles might do + + + align:start position:0% +certain other kinds of styles might do +to manipulate your respon in quite the + + align:start position:0% +to manipulate your respon in quite the + + + align:start position:0% +to manipulate your respon in quite the +in in in in so dramatic a way uh and + + align:start position:0% +in in in in so dramatic a way uh and + + + align:start position:0% +in in in in so dramatic a way uh and +what follows from this Mison sense style + + align:start position:0% +what follows from this Mison sense style + + + align:start position:0% +what follows from this Mison sense style +is what some Scholars have called in + + align:start position:0% +is what some Scholars have called in + + + align:start position:0% +is what some Scholars have called in +camera editing because what's going on + + align:start position:0% +camera editing because what's going on + + + align:start position:0% +camera editing because what's going on +is because the camera the T because the + + align:start position:0% +is because the camera the T because the + + + align:start position:0% +is because the camera the T because the +camera uh is the style is committed to + + align:start position:0% +camera uh is the style is committed to + + + align:start position:0% +camera uh is the style is committed to +long takes what will happen is the + + align:start position:0% +long takes what will happen is the + + + align:start position:0% +long takes what will happen is the +camera will alter its focal length its + + align:start position:0% +camera will alter its focal length its + + + align:start position:0% +camera will alter its focal length its +depth of field uh or it will simply move + + align:start position:0% +depth of field uh or it will simply move + + + align:start position:0% +depth of field uh or it will simply move +and change its it's uh the the the um + + align:start position:0% +and change its it's uh the the the um + + + align:start position:0% +and change its it's uh the the the um +object of its gaze uh while it is in + + align:start position:0% +object of its gaze uh while it is in + + + align:start position:0% +object of its gaze uh while it is in +operation so that it's instead of a + + align:start position:0% +operation so that it's instead of a + + + align:start position:0% +operation so that it's instead of a +series of cuts that are made in the + + align:start position:0% +series of cuts that are made in the + + + align:start position:0% +series of cuts that are made in the +editing room in it's the cameraman + + align:start position:0% +editing room in it's the cameraman + + + align:start position:0% +editing room in it's the cameraman +working the camera who's making certain + + align:start position:0% +working the camera who's making certain + + + align:start position:0% +working the camera who's making certain +decisions that in another kind of film + + align:start position:0% +decisions that in another kind of film + + + align:start position:0% +decisions that in another kind of film +would be made by a film editor after the + + align:start position:0% +would be made by a film editor after the + + + align:start position:0% +would be made by a film editor after the +fact and this creates an effect of not + + align:start position:0% +fact and this creates an effect of not + + + align:start position:0% +fact and this creates an effect of not +exactly improvisation but an effect of + + align:start position:0% +exactly improvisation but an effect of + + + align:start position:0% +exactly improvisation but an effect of +uh an effect that creates the impression + + align:start position:0% +uh an effect that creates the impression + + + align:start position:0% +uh an effect that creates the impression +that there's a sometimes that it's most + + align:start position:0% +that there's a sometimes that it's most + + + align:start position:0% +that there's a sometimes that it's most +powerful or compelling moments as if the + + align:start position:0% +powerful or compelling moments as if the + + + align:start position:0% +powerful or compelling moments as if the +camera is actually uh almost a living + + align:start position:0% +camera is actually uh almost a living + + + align:start position:0% +camera is actually uh almost a living +witness to what seeing and it's and + + align:start position:0% +witness to what seeing and it's and + + + align:start position:0% +witness to what seeing and it's and +responding in very nuanced and sometimes + + align:start position:0% +responding in very nuanced and sometimes + + + align:start position:0% +responding in very nuanced and sometimes +very uh uh abrupt ways to what it sees + + align:start position:0% +very uh uh abrupt ways to what it sees + + + align:start position:0% +very uh uh abrupt ways to what it sees +and hears so there's sometimes moments + + align:start position:0% +and hears so there's sometimes moments + + + align:start position:0% +and hears so there's sometimes moments +in in in both poetic realist films and + + align:start position:0% +in in in both poetic realist films and + + + align:start position:0% +in in in both poetic realist films and +in Italian neorealist films in which a + + align:start position:0% +in Italian neorealist films in which a + + + align:start position:0% +in Italian neorealist films in which a +noise will occur and you'll suddenly see + + align:start position:0% +noise will occur and you'll suddenly see + + + align:start position:0% +noise will occur and you'll suddenly see +the camera turn to find out what the + + align:start position:0% +the camera turn to find out what the + + + align:start position:0% +the camera turn to find out what the +noise is as if it as if the camera is + + align:start position:0% +noise is as if it as if the camera is + + + align:start position:0% +noise is as if it as if the camera is +humanized in this kind of and what + + align:start position:0% +humanized in this kind of and what + + + align:start position:0% +humanized in this kind of and what +follows from that is the camera is all + + align:start position:0% +follows from that is the camera is all + + + align:start position:0% +follows from that is the camera is all +not always but usually set at eye level + + align:start position:0% +not always but usually set at eye level + + + align:start position:0% +not always but usually set at eye level +it does not give a lot of fantastic uh + + align:start position:0% +it does not give a lot of fantastic uh + + + align:start position:0% +it does not give a lot of fantastic uh +distorting uh angle a vision because + + align:start position:0% +distorting uh angle a vision because + + + align:start position:0% +distorting uh angle a vision because +it's not interested in that kind of uh U + + align:start position:0% +it's not interested in that kind of uh U + + + align:start position:0% +it's not interested in that kind of uh U +surreal or expressionist uh + + align:start position:0% +surreal or expressionist uh + + + align:start position:0% +surreal or expressionist uh +representation um uh so misen style in + + align:start position:0% +representation um uh so misen style in + + + align:start position:0% +representation um uh so misen style in +camera editing a second fundamental + + align:start position:0% +camera editing a second fundamental + + + align:start position:0% +camera editing a second fundamental +feature would be filming on location + + align:start position:0% +feature would be filming on location + + + align:start position:0% +feature would be filming on location +right no more in studio there's a kind + + align:start position:0% +right no more in studio there's a kind + + + align:start position:0% +right no more in studio there's a kind +of there's a kind of gross fundamental + + align:start position:0% +of there's a kind of gross fundamental + + + align:start position:0% +of there's a kind of gross fundamental +realism to these kinds of films because + + align:start position:0% +realism to these kinds of films because + + + align:start position:0% +realism to these kinds of films because +they because they use natural lighting + + align:start position:0% +they because they use natural lighting + + + align:start position:0% +they because they use natural lighting +they they in they in they insist or try + + align:start position:0% +they they in they in they insist or try + + + align:start position:0% +they they in they in they insist or try +to insist on them on themselves as as + + align:start position:0% +to insist on them on themselves as as + + + align:start position:0% +to insist on them on themselves as as +actual photographing a world you + + align:start position:0% +actual photographing a world you + + + align:start position:0% +actual photographing a world you +recognize as real not a world that has + + align:start position:0% +recognize as real not a world that has + + + align:start position:0% +recognize as real not a world that has +been artificially constructed in a + + align:start position:0% +been artificially constructed in a + + + align:start position:0% +been artificially constructed in a +studio uh in a studio space um uh uh + + align:start position:0% +studio uh in a studio space um uh uh + + + align:start position:0% +studio uh in a studio space um uh uh +what follows also from the location + + align:start position:0% +what follows also from the location + + + align:start position:0% +what follows also from the location +filming is a commitment to what might be + + align:start position:0% +filming is a commitment to what might be + + + align:start position:0% +filming is a commitment to what might be +called True light and sound right it's + + align:start position:0% +called True light and sound right it's + + + align:start position:0% +called True light and sound right it's +very rare in these kinds of films to + + align:start position:0% +very rare in these kinds of films to + + + align:start position:0% +very rare in these kinds of films to +have external sound the sound even the + + align:start position:0% +have external sound the sound even the + + + align:start position:0% +have external sound the sound even the +music that comes up in many of these in + + align:start position:0% +music that comes up in many of these in + + + align:start position:0% +music that comes up in many of these in +most of these films this is a wonderful + + align:start position:0% +most of these films this is a wonderful + + + align:start position:0% +most of these films this is a wonderful +habit of uh Renoir himself uh the + + align:start position:0% +habit of uh Renoir himself uh the + + + align:start position:0% +habit of uh Renoir himself uh the +sometimes you actually think the music + + align:start position:0% +sometimes you actually think the music + + + align:start position:0% +sometimes you actually think the music +is not a part of the drama but then you + + align:start position:0% +is not a part of the drama but then you + + + align:start position:0% +is not a part of the drama but then you +discover it is almost all the music in + + align:start position:0% +discover it is almost all the music in + + + align:start position:0% +discover it is almost all the music in +renoir's films is is part of the + + align:start position:0% +renoir's films is is part of the + + + align:start position:0% +renoir's films is is part of the +dramatic texture it's not imposed from + + align:start position:0% +dramatic texture it's not imposed from + + + align:start position:0% +dramatic texture it's not imposed from +the outside it's not it's not a + + align:start position:0% +the outside it's not it's not a + + + align:start position:0% +the outside it's not it's not a +soundtrack that doesn't grow out of the + + align:start position:0% +soundtrack that doesn't grow out of the + + + align:start position:0% +soundtrack that doesn't grow out of the +action so if you hear music in a Run + + align:start position:0% +action so if you hear music in a Run + + + align:start position:0% +action so if you hear music in a Run +film I'll show you an example of it in a + + align:start position:0% +film I'll show you an example of it in a + + + align:start position:0% +film I'll show you an example of it in a +moment from budoo uh it turns out that + + align:start position:0% +moment from budoo uh it turns out that + + + align:start position:0% +moment from budoo uh it turns out that +the music is being played by characters + + align:start position:0% +the music is being played by characters + + + align:start position:0% +the music is being played by characters +in the film and you actually end up + + align:start position:0% +in the film and you actually end up + + + align:start position:0% +in the film and you actually end up +seeing them with their instruments uh so + + align:start position:0% +seeing them with their instruments uh so + + + align:start position:0% +seeing them with their instruments uh so +true light and sound and and and and + + align:start position:0% +true light and sound and and and and + + + align:start position:0% +true light and sound and and and and +that what that also means is sometimes + + align:start position:0% +that what that also means is sometimes + + + align:start position:0% +that what that also means is sometimes +sound is obscure + + align:start position:0% +sound is obscure + + + align:start position:0% +sound is obscure +sometimes sound is is uh is overlapped + + align:start position:0% +sometimes sound is is uh is overlapped + + + align:start position:0% +sometimes sound is is uh is overlapped +with other noises sometimes dialogue is + + align:start position:0% +with other noises sometimes dialogue is + + + align:start position:0% +with other noises sometimes dialogue is +hard to hear because there are noises in + + align:start position:0% +hard to hear because there are noises in + + + align:start position:0% +hard to hear because there are noises in +in in in the real world we I I noted + + align:start position:0% +in in in the real world we I I noted + + + align:start position:0% +in in in the real world we I I noted +that this was an aspect of a number of + + align:start position:0% +that this was an aspect of a number of + + + align:start position:0% +that this was an aspect of a number of +American directors in the in the post + + align:start position:0% +American directors in the in the post + + + align:start position:0% +American directors in the in the post +Studio era uh and especially in a film + + align:start position:0% +Studio era uh and especially in a film + + + align:start position:0% +Studio era uh and especially in a film +like mcab where ultman does this kind of + + align:start position:0% +like mcab where ultman does this kind of + + + align:start position:0% +like mcab where ultman does this kind of +thing and I think I think that it uh + + align:start position:0% +thing and I think I think that it uh + + + align:start position:0% +thing and I think I think that it uh +it's it's it's very probable even though + + align:start position:0% +it's it's it's very probable even though + + + align:start position:0% +it's it's it's very probable even though +I don't know this for certain that Alman + + align:start position:0% +I don't know this for certain that Alman + + + align:start position:0% +I don't know this for certain that Alman +himself went to school on these films + + align:start position:0% +himself went to school on these films + + + align:start position:0% +himself went to school on these films +and knew uh the experiments with sound + + align:start position:0% +and knew uh the experiments with sound + + + align:start position:0% +and knew uh the experiments with sound +or the treat M of sound that was + + align:start position:0% +or the treat M of sound that was + + + align:start position:0% +or the treat M of sound that was +characteristic of renoir's U uh of + + align:start position:0% +characteristic of renoir's U uh of + + + align:start position:0% +characteristic of renoir's U uh of +renoir's films and other forms of it of + + align:start position:0% +renoir's films and other forms of it of + + + align:start position:0% +renoir's films and other forms of it of +both French and uh and Italian forms of + + align:start position:0% +both French and uh and Italian forms of + + + align:start position:0% +both French and uh and Italian forms of +of realism what what was called realism + + align:start position:0% +of realism what what was called realism + + + align:start position:0% +of realism what what was called realism +so uh uh and then and then uh two other + + align:start position:0% +so uh uh and then and then uh two other + + + align:start position:0% +so uh uh and then and then uh two other +features one already implied in what I + + align:start position:0% +features one already implied in what I + + + align:start position:0% +features one already implied in what I +was saying a camera that's very fluid in + + align:start position:0% +was saying a camera that's very fluid in + + + align:start position:0% +was saying a camera that's very fluid in +MO in motion uh not in gigantic motion + + align:start position:0% +MO in motion uh not in gigantic motion + + + align:start position:0% +MO in motion uh not in gigantic motion +but very subtle kinds of motions and if + + align:start position:0% +but very subtle kinds of motions and if + + + align:start position:0% +but very subtle kinds of motions and if +you watch Ren War's camera you'll see + + align:start position:0% +you watch Ren War's camera you'll see + + + align:start position:0% +you watch Ren War's camera you'll see +that it's almost constantly making these + + align:start position:0% +that it's almost constantly making these + + + align:start position:0% +that it's almost constantly making these +minute adjustments to what it's looking + + align:start position:0% +minute adjustments to what it's looking + + + align:start position:0% +minute adjustments to what it's looking +at or to what it to or to what it wants + + align:start position:0% +at or to what it to or to what it wants + + + align:start position:0% +at or to what it to or to what it wants +to see and then and then finally + + align:start position:0% +to see and then and then finally + + + align:start position:0% +to see and then and then finally +something I've already said uh there's a + + align:start position:0% +something I've already said uh there's a + + + align:start position:0% +something I've already said uh there's a +great emphasis on what could be called + + align:start position:0% +great emphasis on what could be called + + + align:start position:0% +great emphasis on what could be called +depth of field that is to say you're + + align:start position:0% +depth of field that is to say you're + + + align:start position:0% +depth of field that is to say you're +aware of the dimensionality of the + + align:start position:0% +aware of the dimensionality of the + + + align:start position:0% +aware of the dimensionality of the +images you're looking at so there's a + + align:start position:0% +images you're looking at so there's a + + + align:start position:0% +images you're looking at so there's a +background a middle ground and a + + align:start position:0% +background a middle ground and a + + + align:start position:0% +background a middle ground and a +foreground and uh um very often you'll + + align:start position:0% +foreground and uh um very often you'll + + + align:start position:0% +foreground and uh um very often you'll +see the camera change its focal uh uh + + align:start position:0% +see the camera change its focal uh uh + + + align:start position:0% +see the camera change its focal uh uh +length uh and what will if the + + align:start position:0% +length uh and what will if the + + + align:start position:0% +length uh and what will if the +foreground was in in in Focus you you'll + + align:start position:0% +foreground was in in in Focus you you'll + + + align:start position:0% +foreground was in in in Focus you you'll +actually experience the camera shifting + + align:start position:0% +actually experience the camera shifting + + + align:start position:0% +actually experience the camera shifting +its uh its focus bringing in the + + align:start position:0% +its uh its focus bringing in the + + + align:start position:0% +its uh its focus bringing in the +background that had been out of focus + + align:start position:0% +background that had been out of focus + + + align:start position:0% +background that had been out of focus +before and the effect of this while it + + align:start position:0% +before and the effect of this while it + + + align:start position:0% +before and the effect of this while it +because it takes place within your + + align:start position:0% +because it takes place within your + + + align:start position:0% +because it takes place within your +experience of viewing it doesn't take + + align:start position:0% +experience of viewing it doesn't take + + + align:start position:0% +experience of viewing it doesn't take +place hidden behind behind edits is to + + align:start position:0% +place hidden behind behind edits is to + + + align:start position:0% +place hidden behind behind edits is to +make you part of the process in some + + align:start position:0% +make you part of the process in some + + + align:start position:0% +make you part of the process in some +sense again to make you feel that the + + align:start position:0% +sense again to make you feel that the + + + align:start position:0% +sense again to make you feel that the +camera's behavior is a uh is a part of + + align:start position:0% +camera's behavior is a uh is a part of + + + align:start position:0% +camera's behavior is a uh is a part of +your experience of the film that you're + + align:start position:0% +your experience of the film that you're + + + align:start position:0% +your experience of the film that you're +experiencing the film through a a medium + + align:start position:0% +experiencing the film through a a medium + + + align:start position:0% +experiencing the film through a a medium +that has a kind of immense sensitivity + + align:start position:0% +that has a kind of immense sensitivity + + + align:start position:0% +that has a kind of immense sensitivity +to what it's looking at an immense + + align:start position:0% +to what it's looking at an immense + + + align:start position:0% +to what it's looking at an immense +respect for what it's looking at well uh + + align:start position:0% +respect for what it's looking at well uh + + + align:start position:0% +respect for what it's looking at well uh +so key features let me just summarize + + align:start position:0% +so key features let me just summarize + + + align:start position:0% +so key features let me just summarize +them again amen style which means in + + align:start position:0% +them again amen style which means in + + + align:start position:0% +them again amen style which means in +camera editing uh especially uh filming + + align:start position:0% +camera editing uh especially uh filming + + + align:start position:0% +camera editing uh especially uh filming +on location commitment to True light and + + align:start position:0% +on location commitment to True light and + + + align:start position:0% +on location commitment to True light and +sound a fluid moving camera commitment + + align:start position:0% +sound a fluid moving camera commitment + + + align:start position:0% +sound a fluid moving camera commitment +to depth of field what we might call + + align:start position:0% +to depth of field what we might call + + + align:start position:0% +to depth of field what we might call +again creating this tension between a + + align:start position:0% +again creating this tension between a + + + align:start position:0% +again creating this tension between a +kind of lyrical impulse uh a kind of a + + align:start position:0% +kind of lyrical impulse uh a kind of a + + + align:start position:0% +kind of lyrical impulse uh a kind of a +kind of celebratory or a poetic impulse + + align:start position:0% +kind of celebratory or a poetic impulse + + + align:start position:0% +kind of celebratory or a poetic impulse +as some people have said uh and a and an + + align:start position:0% +as some people have said uh and a and an + + + align:start position:0% +as some people have said uh and a and an +Impulse simply to to denote the world to + + align:start position:0% +Impulse simply to to denote the world to + + + align:start position:0% +Impulse simply to to denote the world to +capture the world to describe or to to + + align:start position:0% +capture the world to describe or to to + + + align:start position:0% +capture the world to describe or to to +dramatize the world fully well I I think + + align:start position:0% +dramatize the world fully well I I think + + + align:start position:0% +dramatize the world fully well I I think +I can show you or or dramatize these + + align:start position:0% +I can show you or or dramatize these + + + align:start position:0% +I can show you or or dramatize these +principles uh more fully for you um uh + + align:start position:0% +principles uh more fully for you um uh + + + align:start position:0% +principles uh more fully for you um uh +if I give you some examples but uh as a + + align:start position:0% +if I give you some examples but uh as a + + + align:start position:0% +if I give you some examples but uh as a +as a way of introducing this I want to + + align:start position:0% +as a way of introducing this I want to + + + align:start position:0% +as a way of introducing this I want to +talk uh very + + align:start position:0% +talk uh very + + + align:start position:0% +talk uh very +quickly about one formulation uh + + align:start position:0% +quickly about one formulation uh + + + align:start position:0% +quickly about one formulation uh +immensely influential formulation about + + align:start position:0% +immensely influential formulation about + + + align:start position:0% +immensely influential formulation about +Renoir that I think you'll find helpful + + align:start position:0% +Renoir that I think you'll find helpful + + + align:start position:0% +Renoir that I think you'll find helpful +and interesting and these are lines that + + align:start position:0% +and interesting and these are lines that + + + align:start position:0% +and interesting and these are lines that +have been written about by the great uh + + align:start position:0% +have been written about by the great uh + + + align:start position:0% +have been written about by the great uh +uh critic Andre Baza who was a great + + align:start position:0% +uh critic Andre Baza who was a great + + + align:start position:0% +uh critic Andre Baza who was a great +champion of renoir's work also a great + + align:start position:0% +champion of renoir's work also a great + + + align:start position:0% +champion of renoir's work also a great +champion of Italian neoism and one of + + align:start position:0% +champion of Italian neoism and one of + + + align:start position:0% +champion of Italian neoism and one of +the great theorists of of the of of the + + align:start position:0% +the great theorists of of the of of the + + + align:start position:0% +the great theorists of of the of of the +cinema uh and uh um we can capture I + + align:start position:0% +cinema uh and uh um we can capture I + + + align:start position:0% +cinema uh and uh um we can capture I +think Ren I think that bazan captured + + align:start position:0% +think Ren I think that bazan captured + + + align:start position:0% +think Ren I think that bazan captured +something of renoir's importance in + + align:start position:0% +something of renoir's importance in + + + align:start position:0% +something of renoir's importance in +these passages from his book titled Jean + + align:start position:0% +these passages from his book titled Jean + + + align:start position:0% +these passages from his book titled Jean +Renoir published in 1971 no one has + + align:start position:0% +Renoir published in 1971 no one has + + + align:start position:0% +Renoir published in 1971 no one has +grasped the true nature of the screen + + align:start position:0% +grasped the true nature of the screen + + + align:start position:0% +grasped the true nature of the screen +better than Ren are so wrote bazan no + + align:start position:0% +better than Ren are so wrote bazan no + + + align:start position:0% +better than Ren are so wrote bazan no +one has more successfully rid it of the + + align:start position:0% +one has more successfully rid it of the + + + align:start position:0% +one has more successfully rid it of the +equivocal of equivocal analogies with + + align:start position:0% +equivocal of equivocal analogies with + + + align:start position:0% +equivocal of equivocal analogies with +painting and the theater plastically the + + align:start position:0% +painting and the theater plastically the + + + align:start position:0% +painting and the theater plastically the +screen is most often made to conform to + + align:start position:0% +screen is most often made to conform to + + + align:start position:0% +screen is most often made to conform to +the limits of the canvas and + + align:start position:0% +the limits of the canvas and + + + align:start position:0% +the limits of the canvas and +dramatically it's modeled on the stage + + align:start position:0% +dramatically it's modeled on the stage + + + align:start position:0% +dramatically it's modeled on the stage +you see what he what bazan is saying is + + align:start position:0% +you see what he what bazan is saying is + + + align:start position:0% +you see what he what bazan is saying is +he's reminding us that when a new + + align:start position:0% +he's reminding us that when a new + + + align:start position:0% +he's reminding us that when a new +technology emerges uh old habits are so + + align:start position:0% +technology emerges uh old habits are so + + + align:start position:0% +technology emerges uh old habits are so +deeply embedded that it's very hard to + + align:start position:0% +deeply embedded that it's very hard to + + + align:start position:0% +deeply embedded that it's very hard to +free oneself from them even though + + align:start position:0% +free oneself from them even though + + + align:start position:0% +free oneself from them even though +there's nothing inherent in the new + + align:start position:0% +there's nothing inherent in the new + + + align:start position:0% +there's nothing inherent in the new +technology that requires you to see the + + align:start position:0% +technology that requires you to see the + + + align:start position:0% +technology that requires you to see the +world in the ways that the older systems + + align:start position:0% +world in the ways that the older systems + + + align:start position:0% +world in the ways that the older systems +did and then there's a period of + + align:start position:0% +did and then there's a period of + + + align:start position:0% +did and then there's a period of +transition that's involved period of + + align:start position:0% +transition that's involved period of + + + align:start position:0% +transition that's involved period of +experiment and Discovery what bazan is + + align:start position:0% +experiment and Discovery what bazan is + + + align:start position:0% +experiment and Discovery what bazan is +saying here is that Renoir is one of the + + align:start position:0% +saying here is that Renoir is one of the + + + align:start position:0% +saying here is that Renoir is one of the +great pioneering discoverers right + + align:start position:0% +great pioneering discoverers right + + + align:start position:0% +great pioneering discoverers right +because with these two traditional + + align:start position:0% +because with these two traditional + + + align:start position:0% +because with these two traditional +references in mind directors have + + align:start position:0% +references in mind directors have + + + align:start position:0% +references in mind directors have +conceived their images as boxed within a + + align:start position:0% +conceived their images as boxed within a + + + align:start position:0% +conceived their images as boxed within a +rectangle as do the painter and the + + align:start position:0% +rectangle as do the painter and the + + + align:start position:0% +rectangle as do the painter and the +stage director and in fact this still + + align:start position:0% +stage director and in fact this still + + + align:start position:0% +stage director and in fact this still +happens today with lazy or foolish + + align:start position:0% +happens today with lazy or foolish + + + align:start position:0% +happens today with lazy or foolish +directors right + + align:start position:0% +directors right + + + align:start position:0% +directors right +war on the other hand understands that + + align:start position:0% +war on the other hand understands that + + + align:start position:0% +war on the other hand understands that +the screen is not a simple rectangle but + + align:start position:0% +the screen is not a simple rectangle but + + + align:start position:0% +the screen is not a simple rectangle but +rather the surface of the viewfinder of + + align:start position:0% +rather the surface of the viewfinder of + + + align:start position:0% +rather the surface of the viewfinder of +his camera it is the opposite of a frame + + align:start position:0% +his camera it is the opposite of a frame + + + align:start position:0% +his camera it is the opposite of a frame +right there's stuff that goes on outside + + align:start position:0% +right there's stuff that goes on outside + + + align:start position:0% +right there's stuff that goes on outside +the frame if it's look right this is a + + align:start position:0% +the frame if it's look right this is a + + + align:start position:0% +the frame if it's look right this is a +brilliant piece of writing I think + + align:start position:0% +brilliant piece of writing I think + + + align:start position:0% +brilliant piece of writing I think +technically this conception of the + + align:start position:0% +technically this conception of the + + + align:start position:0% +technically this conception of the +screen assumes what I bazan shall call + + align:start position:0% +screen assumes what I bazan shall call + + + align:start position:0% +screen assumes what I bazan shall call +lateral depth of field lateral depth of + + align:start position:0% +lateral depth of field lateral depth of + + + align:start position:0% +lateral depth of field lateral depth of +field that is but it's a oxoboron i gu + + align:start position:0% +field that is but it's a oxoboron i gu + + + align:start position:0% +field that is but it's a oxoboron i gu +or a contradiction but right how could + + align:start position:0% +or a contradiction but right how could + + + align:start position:0% +or a contradiction but right how could +there be a lateral but what he means is + + align:start position:0% +there be a lateral but what he means is + + + align:start position:0% +there be a lateral but what he means is +that you become aware of things going on + + align:start position:0% +that you become aware of things going on + + + align:start position:0% +that you become aware of things going on +on the margins of the of the of the + + align:start position:0% +on the margins of the of the of the + + + align:start position:0% +on the margins of the of the of the +visual of the visual field even outside + + align:start position:0% +visual of the visual field even outside + + + align:start position:0% +visual of the visual field even outside +of what you can actually see um um since + + align:start position:0% +of what you can actually see um um since + + + align:start position:0% +of what you can actually see um um since +what we are shown is only significant in + + align:start position:0% +what we are shown is only significant in + + + align:start position:0% +what we are shown is only significant in +terms of what is hidden from us and + + align:start position:0% +terms of what is hidden from us and + + + align:start position:0% +terms of what is hidden from us and +since the value of what we see is + + align:start position:0% +since the value of what we see is + + + align:start position:0% +since the value of what we see is +therefore continually threatened the + + align:start position:0% +therefore continually threatened the + + + align:start position:0% +therefore continually threatened the +misen right what is put in the scene + + align:start position:0% +misen right what is put in the scene + + + align:start position:0% +misen right what is put in the scene +right the Misan sen cannot Li limit + + align:start position:0% +right the Misan sen cannot Li limit + + + align:start position:0% +right the Misan sen cannot Li limit +itself to what is presented on the + + align:start position:0% +itself to what is presented on the + + + align:start position:0% +itself to what is presented on the +screen the rest of the scene while + + align:start position:0% +screen the rest of the scene while + + + align:start position:0% +screen the rest of the scene while +effectively hidden should not cease to + + align:start position:0% +effectively hidden should not cease to + + + align:start position:0% +effectively hidden should not cease to +exist the action is not bounded by the + + align:start position:0% +exist the action is not bounded by the + + + align:start position:0% +exist the action is not bounded by the +screen but merely passes through it and + + align:start position:0% +screen but merely passes through it and + + + align:start position:0% +screen but merely passes through it and +a person who enters the camera's field + + align:start position:0% +a person who enters the camera's field + + + align:start position:0% +a person who enters the camera's field +of vision is coming from other areas of + + align:start position:0% +of vision is coming from other areas of + + + align:start position:0% +of vision is coming from other areas of +the action and not from some limbo or + + align:start position:0% +the action and not from some limbo or + + + align:start position:0% +the action and not from some limbo or +some from imaginary backstage you get + + align:start position:0% +some from imaginary backstage you get + + + align:start position:0% +some from imaginary backstage you get +this think how exciting this is what a + + align:start position:0% +this think how exciting this is what a + + + align:start position:0% +this think how exciting this is what a +what a fundamental Insight it is into + + align:start position:0% +what a fundamental Insight it is into + + + align:start position:0% +what a fundamental Insight it is into +the way a film can become compelling and + + align:start position:0% +the way a film can become compelling and + + + align:start position:0% +the way a film can become compelling and +why it is that so many films might seem + + align:start position:0% +why it is that so many films might seem + + + align:start position:0% +why it is that so many films might seem +factitious to us despite the gross + + align:start position:0% +factitious to us despite the gross + + + align:start position:0% +factitious to us despite the gross +reality of the Cinematic image likewise + + align:start position:0% +reality of the Cinematic image likewise + + + align:start position:0% +reality of the Cinematic image likewise +the camera should be able to spin + + align:start position:0% +the camera should be able to spin + + + align:start position:0% +the camera should be able to spin +suddenly Renoir is full of moments in + + align:start position:0% +suddenly Renoir is full of moments in + + + align:start position:0% +suddenly Renoir is full of moments in +which the camera will make wide SWAT + + align:start position:0% +which the camera will make wide SWAT + + + align:start position:0% +which the camera will make wide SWAT +sometimes sometimes 360 degree uh uh + + align:start position:0% +sometimes sometimes 360 degree uh uh + + + align:start position:0% +sometimes sometimes 360 degree uh uh +circles sometimes 180 degree turns in + + align:start position:0% +circles sometimes 180 degree turns in + + + align:start position:0% +circles sometimes 180 degree turns in +order to remind us of what has not been + + align:start position:0% +order to remind us of what has not been + + + align:start position:0% +order to remind us of what has not been +in the frame of what is on the margins + + align:start position:0% +in the frame of what is on the margins + + + align:start position:0% +in the frame of what is on the margins +of the frame so the camera should be + + align:start position:0% +of the frame so the camera should be + + + align:start position:0% +of the frame so the camera should be +able to spin suddenly without picking up + + align:start position:0% +able to spin suddenly without picking up + + + align:start position:0% +able to spin suddenly without picking up +any holes or dead spots in the action + + align:start position:0% +any holes or dead spots in the action + + + align:start position:0% +any holes or dead spots in the action +well I want to give you two examples of + + align:start position:0% +well I want to give you two examples of + + + align:start position:0% +well I want to give you two examples of +this which are among other things + + align:start position:0% +this which are among other things + + + align:start position:0% +this which are among other things +instances of what I call put my outline + + align:start position:0% +instances of what I call put my outline + + + align:start position:0% +instances of what I call put my outline +back up uh instance of instances of what + + align:start position:0% +back up uh instance of instances of what + + + align:start position:0% +back up uh instance of instances of what +I call Visual style as moral vision and + + align:start position:0% +I call Visual style as moral vision and + + + align:start position:0% +I call Visual style as moral vision and +I'll hopefully be explaining that uh + + align:start position:0% +I'll hopefully be explaining that uh + + + align:start position:0% +I'll hopefully be explaining that uh +term as we as we look at it so so the + + align:start position:0% +term as we as we look at it so so the + + + align:start position:0% +term as we as we look at it so so the +first clip I want to show you uh is from + + align:start position:0% +first clip I want to show you uh is from + + + align:start position:0% +first clip I want to show you uh is from +the film you're going to see tonight and + + align:start position:0% +the film you're going to see tonight and + + + align:start position:0% +the film you're going to see tonight and +it's a way of alerting you to qualities + + align:start position:0% +it's a way of alerting you to qualities + + + align:start position:0% +it's a way of alerting you to qualities +not just in this scene but elsewhere in + + align:start position:0% +not just in this scene but elsewhere in + + + align:start position:0% +not just in this scene but elsewhere in +the film that I hope you'll become much + + align:start position:0% +the film that I hope you'll become much + + + align:start position:0% +the film that I hope you'll become much +more attentive to because we're taking + + align:start position:0% +more attentive to because we're taking + + + align:start position:0% +more attentive to because we're taking +the time to single them out now so here + + align:start position:0% +the time to single them out now so here + + + align:start position:0% +the time to single them out now so here +is a a scene from are we ready grandus + + align:start position:0% +is a a scene from are we ready grandus + + + align:start position:0% +is a a scene from are we ready grandus +uh from from uh um + + align:start position:0% +uh from from uh um + + + align:start position:0% +uh from from uh um +um Grand Illusion uh from relatively + + align:start position:0% +um Grand Illusion uh from relatively + + + align:start position:0% +um Grand Illusion uh from relatively +early in this in the in the + + align:start position:0% + + + + align:start position:0% + +film now U as I've told you this the + + align:start position:0% +film now U as I've told you this the + + + align:start position:0% +film now U as I've told you this the +film is about prisoner French prisoners + + align:start position:0% +film is about prisoner French prisoners + + + align:start position:0% +film is about prisoner French prisoners +of War so here's a scene uh the French + + align:start position:0% +of War so here's a scene uh the French + + + align:start position:0% +of War so here's a scene uh the French +they these are prisoners but it's first + + align:start position:0% +they these are prisoners but it's first + + + align:start position:0% +they these are prisoners but it's first +world war they're allowed to receive + + align:start position:0% +world war they're allowed to receive + + + align:start position:0% +world war they're allowed to receive +packages from their from from from uh in + + align:start position:0% +packages from their from from from uh in + + + align:start position:0% +packages from their from from from uh in +the mail and what and what people in + + align:start position:0% +the mail and what and what people in + + + align:start position:0% +the mail and what and what people in +what people their relatives and friends + + align:start position:0% +what people their relatives and friends + + + align:start position:0% +what people their relatives and friends +send them is food very often all right + + align:start position:0% +send them is food very often all right + + + align:start position:0% +send them is food very often all right +all + + align:start position:0% +all + + + align:start position:0% +all +right can you make it a little louder + + align:start position:0% +right can you make it a little louder + + + align:start position:0% +right can you make it a little louder +not that it really + + align:start position:0% + + + + align:start position:0% + +matters now watch the camera's Behavior + + align:start position:0% +matters now watch the camera's Behavior + + + align:start position:0% +matters now watch the camera's Behavior +what can you freeze it one second look + + align:start position:0% +what can you freeze it one second look + + + align:start position:0% +what can you freeze it one second look +at look at the window there why is that + + align:start position:0% +at look at the window there why is that + + + align:start position:0% +at look at the window there why is that +significant what do you notice in the + + align:start position:0% +significant what do you notice in the + + + align:start position:0% +significant what do you notice in the +window already movement right right and + + align:start position:0% +window already movement right right and + + + align:start position:0% +window already movement right right and +do you see how and and the way the scene + + align:start position:0% +do you see how and and the way the scene + + + align:start position:0% +do you see how and and the way the scene +began we know where that character has + + align:start position:0% +began we know where that character has + + + align:start position:0% +began we know where that character has +come from even though these two + + align:start position:0% +come from even though these two + + + align:start position:0% +come from even though these two +characters are in confrontation and + + align:start position:0% +characters are in confrontation and + + + align:start position:0% +characters are in confrontation and +talking to each other we're aware of + + align:start position:0% +talking to each other we're aware of + + + align:start position:0% +talking to each other we're aware of +activity in the window behind them we're + + align:start position:0% +activity in the window behind them we're + + + align:start position:0% +activity in the window behind them we're +aware of other people in the room it + + align:start position:0% +aware of other people in the room it + + + align:start position:0% +aware of other people in the room it +actually may seem as if it's very easy + + align:start position:0% +actually may seem as if it's very easy + + + align:start position:0% +actually may seem as if it's very easy +to create this effect but of course it's + + align:start position:0% +to create this effect but of course it's + + + align:start position:0% +to create this effect but of course it's +profoundly difficult and and Renoir is + + align:start position:0% +profoundly difficult and and Renoir is + + + align:start position:0% +profoundly difficult and and Renoir is +the Pioneer uh in creating these these + + align:start position:0% +the Pioneer uh in creating these these + + + align:start position:0% +the Pioneer uh in creating these these +kinds of effects how fluid the camera is + + align:start position:0% +kinds of effects how fluid the camera is + + + align:start position:0% +kinds of effects how fluid the camera is +how that's what I want you to watch for + + align:start position:0% +how that's what I want you to watch for + + + align:start position:0% +how that's what I want you to watch for +your awareness of the fact of action + + align:start position:0% +your awareness of the fact of action + + + align:start position:0% +your awareness of the fact of action +that's going on partly outside the + + align:start position:0% +that's going on partly outside the + + + align:start position:0% +that's going on partly outside the +frame all right + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +continue the man at the head table is + + align:start position:0% +continue the man at the head table is + + + align:start position:0% +continue the man at the head table is +the wealthiest of the prisoners and he + + align:start position:0% +the wealthiest of the prisoners and he + + + align:start position:0% +the wealthiest of the prisoners and he +gets the best food so he shares it with + + align:start position:0% +gets the best food so he shares it with + + + align:start position:0% +gets the best food so he shares it with +his + + align:start position:0% + + + + align:start position:0% + +comrades it's a tremendously good meal + + align:start position:0% +comrades it's a tremendously good meal + + + align:start position:0% +comrades it's a tremendously good meal +for + + align:start position:0% +for + + + align:start position:0% +for +prisoners this is the least violent war + + align:start position:0% +prisoners this is the least violent war + + + align:start position:0% +prisoners this is the least violent war +movie ever made + + align:start position:0% + + + + align:start position:0% + +are you beginning to notice how each of + + align:start position:0% +are you beginning to notice how each of + + + align:start position:0% +are you beginning to notice how each of +the characters is individuated in this + + align:start position:0% +the characters is individuated in this + + + align:start position:0% +the characters is individuated in this +scene I don't have time to talk about + + align:start position:0% +scene I don't have time to talk about + + + align:start position:0% +scene I don't have time to talk about +this watch it tonight maybe I'll say a + + align:start position:0% +this watch it tonight maybe I'll say a + + + align:start position:0% +this watch it tonight maybe I'll say a +bit about it tonight when I introduced + + align:start position:0% +bit about it tonight when I introduced + + + align:start position:0% +bit about it tonight when I introduced +the fil but each one of them we can + + align:start position:0% +the fil but each one of them we can + + + align:start position:0% +the fil but each one of them we can +almost we can tell what social class + + align:start position:0% +almost we can tell what social class + + + align:start position:0% +almost we can tell what social class +they belong to from their dress from + + align:start position:0% +they belong to from their dress from + + + align:start position:0% +they belong to from their dress from +their mode of + + align:start position:0% + + + + align:start position:0% + +speech you see how quietly but complexly + + align:start position:0% +speech you see how quietly but complexly + + + align:start position:0% +speech you see how quietly but complexly +the camera + + align:start position:0% +the camera + + + align:start position:0% +the camera +examines the + + align:start position:0% + + + + align:start position:0% + +space and that's J gaban one of the + + align:start position:0% +space and that's J gaban one of the + + + align:start position:0% +space and that's J gaban one of the +great one of the central + + align:start position:0% + + + + align:start position:0% + +characters and one of the great French + + align:start position:0% + + + + align:start position:0% + +actors all right we have to stop this + + align:start position:0% +actors all right we have to stop this + + + align:start position:0% +actors all right we have to stop this +because I'm sorry I have to cut this + + align:start position:0% +because I'm sorry I have to cut this + + + align:start position:0% +because I'm sorry I have to cut this +short it's a brilliant scene watch for + + align:start position:0% +short it's a brilliant scene watch for + + + align:start position:0% +short it's a brilliant scene watch for +it tonight comes fairly early in the + + align:start position:0% +it tonight comes fairly early in the + + + align:start position:0% +it tonight comes fairly early in the +film watch how each of the characters is + + align:start position:0% +film watch how each of the characters is + + + align:start position:0% +film watch how each of the characters is +individuated as the scene goes on how + + align:start position:0% +individuated as the scene goes on how + + + align:start position:0% +individuated as the scene goes on how +crowded the scene is in one sense how + + align:start position:0% +crowded the scene is in one sense how + + + align:start position:0% +crowded the scene is in one sense how +how how you're aware of activities and + + align:start position:0% +how how you're aware of activities and + + + align:start position:0% +how how you're aware of activities and +even conversations that are taking place + + align:start position:0% +even conversations that are taking place + + + align:start position:0% +even conversations that are taking place +outside the uh uh frame of the of the of + + align:start position:0% +outside the uh uh frame of the of the of + + + align:start position:0% +outside the uh uh frame of the of the of +the camera itself and when the camera + + align:start position:0% +the camera itself and when the camera + + + align:start position:0% +the camera itself and when the camera +shifts over to one set of characters + + align:start position:0% +shifts over to one set of characters + + + align:start position:0% +shifts over to one set of characters +you're aware of other conversations that + + align:start position:0% +you're aware of other conversations that + + + align:start position:0% +you're aware of other conversations that +that are ongoing other words the sense + + align:start position:0% +that are ongoing other words the sense + + + align:start position:0% +that are ongoing other words the sense +of reality that this style creates is + + align:start position:0% +of reality that this style creates is + + + align:start position:0% +of reality that this style creates is +profound and compelling it seems to me + + align:start position:0% +profound and compelling it seems to me + + + align:start position:0% +profound and compelling it seems to me +um powerful but I want to show you + + align:start position:0% +um powerful but I want to show you + + + align:start position:0% +um powerful but I want to show you +another and even more dramatic clip uh + + align:start position:0% +another and even more dramatic clip uh + + + align:start position:0% +another and even more dramatic clip uh +because partly because it comes from a + + align:start position:0% +because partly because it comes from a + + + align:start position:0% +because partly because it comes from a +film you've not seen because and because + + align:start position:0% +film you've not seen because and because + + + align:start position:0% +film you've not seen because and because +it captures certain other qualities in + + align:start position:0% +it captures certain other qualities in + + + align:start position:0% +it captures certain other qualities in +in uh renoir's R in renoir's work and + + align:start position:0% +in uh renoir's R in renoir's work and + + + align:start position:0% +in uh renoir's R in renoir's work and +this is this is the famous ending of + + align:start position:0% +this is this is the famous ending of + + + align:start position:0% +this is this is the famous ending of +budo save from drowning let me set the + + align:start position:0% +budo save from drowning let me set the + + + align:start position:0% +budo save from drowning let me set the +scene for you while uh Kristen's getting + + align:start position:0% +scene for you while uh Kristen's getting + + + align:start position:0% +scene for you while uh Kristen's getting +it up uh in this scene uh this comes at + + align:start position:0% +it up uh in this scene uh this comes at + + + align:start position:0% +it up uh in this scene uh this comes at +the very end of the film uh it's a the + + align:start position:0% +the very end of the film uh it's a the + + + align:start position:0% +the very end of the film uh it's a the +film is a satire and budoo is a bum a + + align:start position:0% +film is a satire and budoo is a bum a + + + align:start position:0% +film is a satire and budoo is a bum a +clar of whom there were tens of there + + align:start position:0% +clar of whom there were tens of there + + + align:start position:0% +clar of whom there were tens of there +were thousands if not tens of thousands + + align:start position:0% +were thousands if not tens of thousands + + + align:start position:0% +were thousands if not tens of thousands +living in Paris during the era when the + + align:start position:0% +living in Paris during the era when the + + + align:start position:0% +living in Paris during the era when the +film was made uh a kind of uh uh + + align:start position:0% +film was made uh a kind of uh uh + + + align:start position:0% +film was made uh a kind of uh uh +like like like the character that the + + align:start position:0% +like like like the character that the + + + align:start position:0% +like like like the character that the +chaplain figure plays in the American + + align:start position:0% +chaplain figure plays in the American + + + align:start position:0% +chaplain figure plays in the American +films although Michelle Simone is a much + + align:start position:0% +films although Michelle Simone is a much + + + align:start position:0% +films although Michelle Simone is a much +more massive figure than chaplain and uh + + align:start position:0% +more massive figure than chaplain and uh + + + align:start position:0% +more massive figure than chaplain and uh +in the very beginning of the film he + + align:start position:0% +in the very beginning of the film he + + + align:start position:0% +in the very beginning of the film he +plays this he seems to try he jumps into + + align:start position:0% +plays this he seems to try he jumps into + + + align:start position:0% +plays this he seems to try he jumps into +the river to try to commit suicide + + align:start position:0% +the river to try to commit suicide + + + align:start position:0% +the river to try to commit suicide +because he's lost his beloved dog he's a + + align:start position:0% +because he's lost his beloved dog he's a + + + align:start position:0% +because he's lost his beloved dog he's a +figure of Despair and a middle class + + align:start position:0% +figure of Despair and a middle class + + + align:start position:0% +figure of Despair and a middle class +book seller named leting Gua spying him + + align:start position:0% +book seller named leting Gua spying him + + + align:start position:0% +book seller named leting Gua spying him +through his spy glasses he's looking out + + align:start position:0% +through his spy glasses he's looking out + + + align:start position:0% +through his spy glasses he's looking out +of the out of his uh book out of the + + align:start position:0% +of the out of his uh book out of the + + + align:start position:0% +of the out of his uh book out of the +windows of his book of his book shop + + align:start position:0% +windows of his book of his book shop + + + align:start position:0% +windows of his book of his book shop +sees this bum at first he look Oh What A + + align:start position:0% +sees this bum at first he look Oh What A + + + align:start position:0% +sees this bum at first he look Oh What A +Perfect Bum he thinks to himself what a + + align:start position:0% +Perfect Bum he thinks to himself what a + + + align:start position:0% +Perfect Bum he thinks to himself what a +perfect embodiment of what a is + + align:start position:0% +perfect embodiment of what a is + + + align:start position:0% +perfect embodiment of what a is +and then he becomes upset when he sees + + align:start position:0% +and then he becomes upset when he sees + + + align:start position:0% +and then he becomes upset when he sees +the guy jump into the river and he runs + + align:start position:0% +the guy jump into the river and he runs + + + align:start position:0% +the guy jump into the river and he runs +out he dives into the river to save him + + align:start position:0% +out he dives into the river to save him + + + align:start position:0% +out he dives into the river to save him +and it turns into a kind of comic scene + + align:start position:0% +and it turns into a kind of comic scene + + + align:start position:0% +and it turns into a kind of comic scene +of saving people gather on the bridge + + align:start position:0% +of saving people gather on the bridge + + + align:start position:0% +of saving people gather on the bridge +and look down and so forth he pulls him + + align:start position:0% +and look down and so forth he pulls him + + + align:start position:0% +and look down and so forth he pulls him +out brings him into his home his wife is + + align:start position:0% +out brings him into his home his wife is + + + align:start position:0% +out brings him into his home his wife is +is very resentful of it but eventually + + align:start position:0% +is very resentful of it but eventually + + + align:start position:0% +is very resentful of it but eventually +she adapts and he moves into the uh + + align:start position:0% +she adapts and he moves into the uh + + + align:start position:0% +she adapts and he moves into the uh +middle class book seller's home and of + + align:start position:0% +middle class book seller's home and of + + + align:start position:0% +middle class book seller's home and of +course he WS Havoc there because he + + align:start position:0% +course he WS Havoc there because he + + + align:start position:0% +course he WS Havoc there because he +stands for nature itself he can't be + + align:start position:0% +stands for nature itself he can't be + + + align:start position:0% +stands for nature itself he can't be +civilized or tamed right he's buddo so + + align:start position:0% +civilized or tamed right he's buddo so + + + align:start position:0% +civilized or tamed right he's buddo so +saved from the waters right so he saved + + align:start position:0% +saved from the waters right so he saved + + + align:start position:0% +saved from the waters right so he saved +from The Waters at the end but as you'll + + align:start position:0% +from The Waters at the end but as you'll + + + align:start position:0% +from The Waters at the end but as you'll +see at the at the beginning but as + + align:start position:0% +see at the at the beginning but as + + + align:start position:0% +see at the at the beginning but as +you'll see at the end of the film he's + + align:start position:0% +you'll see at the end of the film he's + + + align:start position:0% +you'll see at the end of the film he's +back to the waters so here so what + + align:start position:0% +back to the waters so here so what + + + align:start position:0% +back to the waters so here so what +happens essentially is among other + + align:start position:0% +happens essentially is among other + + + align:start position:0% +happens essentially is among other +things in the course of the story this + + align:start position:0% +things in the course of the story this + + + align:start position:0% +things in the course of the story this +this uh figure of raw nature turns out + + align:start position:0% +this uh figure of raw nature turns out + + + align:start position:0% +this uh figure of raw nature turns out +that he can't quite be civilized one of + + align:start position:0% +that he can't quite be civilized one of + + + align:start position:0% +that he can't quite be civilized one of +the things he does is he manages to have + + align:start position:0% +the things he does is he manages to have + + + align:start position:0% +the things he does is he manages to have +a love affair or to or to seduce I could + + align:start position:0% +a love affair or to or to seduce I could + + + align:start position:0% +a love affair or to or to seduce I could +shouldn't call it a love affair both + + align:start position:0% +shouldn't call it a love affair both + + + align:start position:0% +shouldn't call it a love affair both +leting gu's mistress a young maid who + + align:start position:0% +leting gu's mistress a young maid who + + + align:start position:0% +leting gu's mistress a young maid who +works in his house and his + + align:start position:0% +works in his house and his + + + align:start position:0% +works in his house and his +wife and a kind of semis Scandal occurs + + align:start position:0% +wife and a kind of semis Scandal occurs + + + align:start position:0% +wife and a kind of semis Scandal occurs +in which F uh in which the uh uh um in + + align:start position:0% +in which F uh in which the uh uh um in + + + align:start position:0% +in which F uh in which the uh uh um in +which the character play played by + + align:start position:0% +which the character play played by + + + align:start position:0% +which the character play played by +Michelle Simon wins the lottery and + + align:start position:0% +Michelle Simon wins the lottery and + + + align:start position:0% +Michelle Simon wins the lottery and +becomes very rich so he then very a + + align:start position:0% +becomes very rich so he then very a + + + align:start position:0% +becomes very rich so he then very a +marriage of convenience is arranged and + + align:start position:0% +marriage of convenience is arranged and + + + align:start position:0% +marriage of convenience is arranged and +he's going to marry the maid that had + + align:start position:0% +he's going to marry the maid that had + + + align:start position:0% +he's going to marry the maid that had +been the book seller's mistress and this + + align:start position:0% +been the book seller's mistress and this + + + align:start position:0% +been the book seller's mistress and this +sort of straightens everything out + + align:start position:0% +sort of straightens everything out + + + align:start position:0% +sort of straightens everything out +because there had been a kind of Scandal + + align:start position:0% +because there had been a kind of Scandal + + + align:start position:0% +because there had been a kind of Scandal +brewing and in the and the final scene + + align:start position:0% +brewing and in the and the final scene + + + align:start position:0% +brewing and in the and the final scene +of the film is the wedding party in + + align:start position:0% +of the film is the wedding party in + + + align:start position:0% +of the film is the wedding party in +which in which in which uh budo his new + + align:start position:0% +which in which in which uh budo his new + + + align:start position:0% +which in which in which uh budo his new +bride the book seller and his wife are + + align:start position:0% +bride the book seller and his wife are + + + align:start position:0% +bride the book seller and his wife are +in a boat together celebrating the + + align:start position:0% + + + + align:start position:0% + +wedding and and of course these images + + align:start position:0% +wedding and and of course these images + + + align:start position:0% +wedding and and of course these images +would have invoked Renoir Pear's films + + align:start position:0% +would have invoked Renoir Pear's films + + + align:start position:0% +would have invoked Renoir Pear's films +paintings very powerfully as + + align:start position:0% +paintings very powerfully as + + + align:start position:0% +paintings very powerfully as +[Music] + + align:start position:0% + + + + align:start position:0% + +well many of Jean renoir's treatment uh + + align:start position:0% +well many of Jean renoir's treatment uh + + + align:start position:0% +well many of Jean renoir's treatment uh +films said in nature are said to have + + align:start position:0% +films said in nature are said to have + + + align:start position:0% +films said in nature are said to have +been influenced in some ways by his + + align:start position:0% +been influenced in some ways by his + + + align:start position:0% +been influenced in some ways by his +father's paintings there's Michelle + + align:start position:0% +father's paintings there's Michelle + + + align:start position:0% +father's paintings there's Michelle +Simone in his new + + align:start position:0% +Simone in his new + + + align:start position:0% +Simone in his new +bride you see how there's music but it's + + align:start position:0% +bride you see how there's music but it's + + + align:start position:0% +bride you see how there's music but it's +coming from Source inside the story + + align:start position:0% + + + + align:start position:0% + +that's the book seller in the back with + + align:start position:0% +that's the book seller in the back with + + + align:start position:0% +that's the book seller in the back with +a white hat everything looks + + align:start position:0% + + + + align:start position:0% + +wonderful one thing I think one reason I + + align:start position:0% +wonderful one thing I think one reason I + + + align:start position:0% +wonderful one thing I think one reason I +wanted you to see this is look how + + align:start position:0% +wanted you to see this is look how + + + align:start position:0% +wanted you to see this is look how +leisurely this is even I mean it was + + align:start position:0% +leisurely this is even I mean it was + + + align:start position:0% +leisurely this is even I mean it was +where is it going we're at the end of + + align:start position:0% +where is it going we're at the end of + + + align:start position:0% +where is it going we're at the end of +the movie yet now and yet look how how + + align:start position:0% +the movie yet now and yet look how how + + + align:start position:0% +the movie yet now and yet look how how +the film sort of almost as if it doesn't + + align:start position:0% +the film sort of almost as if it doesn't + + + align:start position:0% +the film sort of almost as if it doesn't +even at this stage doesn't want to end + + align:start position:0% +even at this stage doesn't want to end + + + align:start position:0% +even at this stage doesn't want to end +doesn't want to move + + align:start position:0% + + + + align:start position:0% + +forward all right he reaches for the + + align:start position:0% +forward all right he reaches for the + + + align:start position:0% +forward all right he reaches for the +flower + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +he + + align:start position:0% +he + + + align:start position:0% +he +[Music] + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% + + + + align:start position:0% + +now remember he's just been married + + align:start position:0% +now remember he's just been married + + + align:start position:0% +now remember he's just been married +what's happening to him where's he + + align:start position:0% + + + + align:start position:0% + +going you know often when I show this to + + align:start position:0% +going you know often when I show this to + + + align:start position:0% +going you know often when I show this to +my classes because I'm always worried + + align:start position:0% +my classes because I'm always worried + + + align:start position:0% +my classes because I'm always worried +about time I get impatient here but in + + align:start position:0% +about time I get impatient here but in + + + align:start position:0% +about time I get impatient here but in +fact it's a bad reaction because the + + align:start position:0% +fact it's a bad reaction because the + + + align:start position:0% +fact it's a bad reaction because the +film wants us to savor what it's doing + + align:start position:0% +film wants us to savor what it's doing + + + align:start position:0% +film wants us to savor what it's doing +right it can you feel the sort of + + align:start position:0% +right it can you feel the sort of + + + align:start position:0% +right it can you feel the sort of +lyrical tendency just to sort of look at + + align:start position:0% +lyrical tendency just to sort of look at + + + align:start position:0% +lyrical tendency just to sort of look at +the world in its beauty + + align:start position:0% +the world in its beauty + + + align:start position:0% +the world in its beauty +as if the impulse to tell a story and + + align:start position:0% +as if the impulse to tell a story and + + + align:start position:0% +as if the impulse to tell a story and +the impulse to photograph the world are + + align:start position:0% +the impulse to photograph the world are + + + align:start position:0% +the impulse to photograph the world are +in some degree in conflict because the + + align:start position:0% +in some degree in conflict because the + + + align:start position:0% +in some degree in conflict because the +world keeps resisting the categories you + + align:start position:0% +world keeps resisting the categories you + + + align:start position:0% +world keeps resisting the categories you +put it in the camera keeps discovering + + align:start position:0% +put it in the camera keeps discovering + + + align:start position:0% +put it in the camera keeps discovering +new things to look at so here budo comes + + align:start position:0% +new things to look at so here budo comes + + + align:start position:0% +new things to look at so here budo comes +ashore think of how anarchic this vision + + align:start position:0% +ashore think of how anarchic this vision + + + align:start position:0% +ashore think of how anarchic this vision +of life is because he's just deserted + + align:start position:0% +of life is because he's just deserted + + + align:start position:0% +of life is because he's just deserted +his new bride and his new wedding and + + align:start position:0% +his new bride and his new wedding and + + + align:start position:0% +his new bride and his new wedding and +all the right doesn't seem to matter he + + align:start position:0% +all the right doesn't seem to matter he + + + align:start position:0% +all the right doesn't seem to matter he +gets up on + + align:start position:0% +gets up on + + + align:start position:0% +gets up on +shore he's still wearing his wet clothes + + align:start position:0% +shore he's still wearing his wet clothes + + + align:start position:0% +shore he's still wearing his wet clothes +and this becomes then a highly symbolic + + align:start position:0% +and this becomes then a highly symbolic + + + align:start position:0% +and this becomes then a highly symbolic +[Music] + + align:start position:0% + + + + align:start position:0% + +moment he sees a + + align:start position:0% +moment he sees a + + + align:start position:0% +moment he sees a +scarecrow now he's going to shed his + + align:start position:0% +scarecrow now he's going to shed his + + + align:start position:0% +scarecrow now he's going to shed his +middle class + + align:start position:0% +middle class + + + align:start position:0% +middle class +identity by changing clothes with it + + align:start position:0% +identity by changing clothes with it + + + align:start position:0% +identity by changing clothes with it +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +[Music] + + align:start position:0% + + + + align:start position:0% + +I suppose one fundamental aspect of the + + align:start position:0% +I suppose one fundamental aspect of the + + + align:start position:0% +I suppose one fundamental aspect of the +satire is what the film is saying is + + align:start position:0% +satire is what the film is saying is + + + align:start position:0% +satire is what the film is saying is +look nature is always more untamed and + + align:start position:0% +look nature is always more untamed and + + + align:start position:0% +look nature is always more untamed and +difficult than middle class uh Romantics + + align:start position:0% +difficult than middle class uh Romantics + + + align:start position:0% +difficult than middle class uh Romantics +imagine right it's not a table thing + + align:start position:0% +imagine right it's not a table thing + + + align:start position:0% +imagine right it's not a table thing +well here he comes eating his bread + + align:start position:0% +well here he comes eating his bread + + + align:start position:0% +well here he comes eating his bread +newly free again + + align:start position:0% +newly free again + + + align:start position:0% +newly free again +right identifies with the goat shares + + align:start position:0% +right identifies with the goat shares + + + align:start position:0% +right identifies with the goat shares +his food with the goat + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% + + + + align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +pay attention to the + + align:start position:0% + + + + align:start position:0% + +camera for + + align:start position:0% + + + + align:start position:0% + +okay shut it off at one point in his + + align:start position:0% +okay shut it off at one point in his + + + align:start position:0% +okay shut it off at one point in his +book on bazan bazan's book on Renoir he + + align:start position:0% +book on bazan bazan's book on Renoir he + + + align:start position:0% +book on bazan bazan's book on Renoir he +talks about this sequence and I want to + + align:start position:0% +talks about this sequence and I want to + + + align:start position:0% +talks about this sequence and I want to +remind you that he talks about this + + align:start position:0% +remind you that he talks about this + + + align:start position:0% +remind you that he talks about this +sequence in an era before it was + + align:start position:0% +sequence in an era before it was + + + align:start position:0% +sequence in an era before it was +possible to easily repl movies right it + + align:start position:0% +possible to easily repl movies right it + + + align:start position:0% +possible to easily repl movies right it +was an ERA long before videotape long + + align:start position:0% +was an ERA long before videotape long + + + align:start position:0% +was an ERA long before videotape long +before television actually uh and when + + align:start position:0% +before television actually uh and when + + + align:start position:0% +before television actually uh and when +when you wanted to watch a movie again + + align:start position:0% +when you wanted to watch a movie again + + + align:start position:0% +when you wanted to watch a movie again +you had to get projectors and show them + + align:start position:0% +you had to get projectors and show them + + + align:start position:0% +you had to get projectors and show them +so very often when bazan was writing + + align:start position:0% +so very often when bazan was writing + + + align:start position:0% +so very often when bazan was writing +about his films he was working for + + align:start position:0% +about his films he was working for + + + align:start position:0% +about his films he was working for +memory and he makes some technical + + align:start position:0% +memory and he makes some technical + + + align:start position:0% +memory and he makes some technical +mistakes but he gets the essence of the + + align:start position:0% +mistakes but he gets the essence of the + + + align:start position:0% +mistakes but he gets the essence of the +scene right listen to this he says + + align:start position:0% +scene right listen to this he says + + + align:start position:0% +scene right listen to this he says +Renoir the moralist is also the most + + align:start position:0% +Renoir the moralist is also the most + + + align:start position:0% +Renoir the moralist is also the most +realistic of filmmakers sacrificing + + align:start position:0% +realistic of filmmakers sacrificing + + + align:start position:0% +realistic of filmmakers sacrificing +reality as little as possible to the + + align:start position:0% +reality as little as possible to the + + + align:start position:0% +reality as little as possible to the +thrust of his message the last scenes + + align:start position:0% +thrust of his message the last scenes + + + align:start position:0% +thrust of his message the last scenes +from budo could serve as an epigraph to + + align:start position:0% +from budo could serve as an epigraph to + + + align:start position:0% +from budo could serve as an epigraph to +all of renoir's French work budo newly + + align:start position:0% +all of renoir's French work budo newly + + + align:start position:0% +all of renoir's French work budo newly +wed throws himself into the water not + + align:start position:0% +wed throws himself into the water not + + + align:start position:0% +wed throws himself into the water not +exactly it's an accident it's important + + align:start position:0% +exactly it's an accident it's important + + + align:start position:0% +exactly it's an accident it's important +that it's an accident it's not like he + + align:start position:0% +that it's an accident it's not like he + + + align:start position:0% +that it's an accident it's not like he +was planning his Escape right because + + align:start position:0% +was planning his Escape right because + + + align:start position:0% +was planning his Escape right because +he's nature he doesn't he doesn't think + + align:start position:0% +he's nature he doesn't he doesn't think + + + align:start position:0% +he's nature he doesn't he doesn't think +he stands for the natural right uh but + + align:start position:0% +he stands for the natural right uh but + + + align:start position:0% +he stands for the natural right uh but +but by accident the book the the the + + align:start position:0% +but by accident the book the the the + + + align:start position:0% +but by accident the book the the the +boat overturns and budo makes his his + + align:start position:0% +boat overturns and budo makes his his + + + align:start position:0% +boat overturns and budo makes his his +Escape because it's possible to do so + + align:start position:0% +Escape because it's possible to do so + + + align:start position:0% +Escape because it's possible to do so +it's not as if it's premeditated that's + + align:start position:0% +it's not as if it's premeditated that's + + + align:start position:0% +it's not as if it's premeditated that's +important and um uh dramatic or + + align:start position:0% +important and um uh dramatic or + + + align:start position:0% +important and um uh dramatic or +psychological logic would demand that + + align:start position:0% +psychological logic would demand that + + + align:start position:0% +psychological logic would demand that +such an act have a precise meaning is it + + align:start position:0% +such an act have a precise meaning is it + + + align:start position:0% +such an act have a precise meaning is it +despair or suicide no it's not at all in + + align:start position:0% +despair or suicide no it's not at all in + + + align:start position:0% +despair or suicide no it's not at all in +fact it's just an accident uh um budo is + + align:start position:0% +fact it's just an accident uh um budo is + + + align:start position:0% +fact it's just an accident uh um budo is +uh budo without maybe even fully + + align:start position:0% +uh budo without maybe even fully + + + align:start position:0% +uh budo without maybe even fully +realizing it is trying to flee the + + align:start position:0% +realizing it is trying to flee the + + + align:start position:0% +realizing it is trying to flee the +chains of a Bourgeois marriage + + align:start position:0% +chains of a Bourgeois marriage + + + align:start position:0% +chains of a Bourgeois marriage +um Renoir like his character forgets the + + align:start position:0% +um Renoir like his character forgets the + + + align:start position:0% +um Renoir like his character forgets the +act in favor of the fact and the true + + align:start position:0% +act in favor of the fact and the true + + + align:start position:0% +act in favor of the fact and the true +object of the scene ceases gradually to + + align:start position:0% +object of the scene ceases gradually to + + + align:start position:0% +object of the scene ceases gradually to +be what budo intends right what is budo + + align:start position:0% +be what budo intends right what is budo + + + align:start position:0% +be what budo intends right what is budo +up to why is he doing this I don't even + + align:start position:0% +up to why is he doing this I don't even + + + align:start position:0% +up to why is he doing this I don't even +think he's bazan is right to even raise + + align:start position:0% +think he's bazan is right to even raise + + + align:start position:0% +think he's bazan is right to even raise +the question because what we think he's + + align:start position:0% +the question because what we think he's + + + align:start position:0% +the question because what we think he's +doing is just enjoying himself self + + align:start position:0% +doing is just enjoying himself self + + + align:start position:0% +doing is just enjoying himself self +right then it occurs to him when he gets + + align:start position:0% +right then it occurs to him when he gets + + + align:start position:0% +right then it occurs to him when he gets +on land that he's free of his marriage + + align:start position:0% +on land that he's free of his marriage + + + align:start position:0% +on land that he's free of his marriage +right um uh + + align:start position:0% + + + + align:start position:0% + +um Renoir like his character forgets the + + align:start position:0% +um Renoir like his character forgets the + + + align:start position:0% +um Renoir like his character forgets the +act in favor of the fact and the true + + align:start position:0% +act in favor of the fact and the true + + + align:start position:0% +act in favor of the fact and the true +object of the scene ceases to be Bud's + + align:start position:0% +object of the scene ceases to be Bud's + + + align:start position:0% +object of the scene ceases to be Bud's +intentions and becomes the spectacle of + + align:start position:0% +intentions and becomes the spectacle of + + + align:start position:0% +intentions and becomes the spectacle of +his pleasure and by extension the + + align:start position:0% +his pleasure and by extension the + + + align:start position:0% +his pleasure and by extension the +enjoyment that Renoir derives or we as + + align:start position:0% +enjoyment that Renoir derives or we as + + + align:start position:0% +enjoyment that Renoir derives or we as +viewers derive from the antics of his + + align:start position:0% +viewers derive from the antics of his + + + align:start position:0% +viewers derive from the antics of his +hero the water is no longer water but + + align:start position:0% +hero the water is no longer water but + + + align:start position:0% +hero the water is no longer water but +more specifically the water of the marn + + align:start position:0% +more specifically the water of the marn + + + align:start position:0% +more specifically the water of the marn +a tributary of the sen in in uh August + + align:start position:0% +a tributary of the sen in in uh August + + + align:start position:0% +a tributary of the sen in in uh August +Michelle Simone floats on it turns over + + align:start position:0% +Michelle Simone floats on it turns over + + + align:start position:0% +Michelle Simone floats on it turns over +sprays like a seal and as he plays we + + align:start position:0% +sprays like a seal and as he plays we + + + align:start position:0% +sprays like a seal and as he plays we +begin to perceive the depth quality and + + align:start position:0% +begin to perceive the depth quality and + + + align:start position:0% +begin to perceive the depth quality and +even the tepid warmth of the water when + + align:start position:0% +even the tepid warmth of the water when + + + align:start position:0% +even the tepid warmth of the water when +he comes up on the bank an extraordinary + + align:start position:0% +he comes up on the bank an extraordinary + + + align:start position:0% +he comes up on the bank an extraordinary +slow he calls it a 360 degree pan + + align:start position:0% +slow he calls it a 360 degree pan + + + align:start position:0% +slow he calls it a 360 degree pan +remember that final move the camera but + + align:start position:0% +remember that final move the camera but + + + align:start position:0% +remember that final move the camera but +it's probably 180° he's remembering it + + align:start position:0% +it's probably 180° he's remembering it + + + align:start position:0% +it's probably 180° he's remembering it +imperfectly shows us the countryside he + + align:start position:0% +imperfectly shows us the countryside he + + + align:start position:0% +imperfectly shows us the countryside he +sees before him the world he sees before + + align:start position:0% +sees before him the world he sees before + + + align:start position:0% +sees before him the world he sees before +him but this effect by Nature + + align:start position:0% +him but this effect by Nature + + + align:start position:0% +him but this effect by Nature +descriptive which could indicate space + + align:start position:0% +descriptive which could indicate space + + + align:start position:0% +descriptive which could indicate space +and Liberty regained is of unequal + + align:start position:0% +and Liberty regained is of unequal + + + align:start position:0% +and Liberty regained is of unequal +poetry because what moves us is not the + + align:start position:0% +poetry because what moves us is not the + + + align:start position:0% +poetry because what moves us is not the +fact that this Countryside is once more + + align:start position:0% +fact that this Countryside is once more + + + align:start position:0% +fact that this Countryside is once more +again bdo's domain although that is one + + align:start position:0% +again bdo's domain although that is one + + + align:start position:0% +again bdo's domain although that is one +effect of it budoo is free and the + + align:start position:0% +effect of it budoo is free and the + + + align:start position:0% +effect of it budoo is free and the +camera shows the beauty and freedom of + + align:start position:0% +camera shows the beauty and freedom of + + + align:start position:0% +camera shows the beauty and freedom of +the world in that in that 180 degree pan + + align:start position:0% +the world in that in that 180 degree pan + + + align:start position:0% +the world in that in that 180 degree pan +but that the banks of the m and all + + align:start position:0% +but that the banks of the m and all + + + align:start position:0% +but that the banks of the m and all +their richness of detail are + + align:start position:0% +their richness of detail are + + + align:start position:0% +their richness of detail are +intrinsically beautiful and you're aware + + align:start position:0% +intrinsically beautiful and you're aware + + + align:start position:0% +intrinsically beautiful and you're aware +of that aren't you at the end of the pan + + align:start position:0% +of that aren't you at the end of the pan + + + align:start position:0% +of that aren't you at the end of the pan +the camera picks up a bit of grass or + + align:start position:0% +the camera picks up a bit of grass or + + + align:start position:0% +the camera picks up a bit of grass or +where in closeup one one can see the + + align:start position:0% +where in closeup one one can see the + + + align:start position:0% +where in closeup one one can see the +dust uh that the Heat and the wind have + + align:start position:0% +dust uh that the Heat and the wind have + + + align:start position:0% +dust uh that the Heat and the wind have +lifted From the Path one can almost feel + + align:start position:0% +lifted From the Path one can almost feel + + + align:start position:0% +lifted From the Path one can almost feel +it between one's fingers if I were + + align:start position:0% +it between one's fingers if I were + + + align:start position:0% +it between one's fingers if I were +deprived of the pleasure of seeing budo + + align:start position:0% +deprived of the pleasure of seeing budo + + + align:start position:0% +deprived of the pleasure of seeing budo +again for the rest of my days I remember + + align:start position:0% +again for the rest of my days I remember + + + align:start position:0% +again for the rest of my days I remember +the first time I read those lines and I + + align:start position:0% +the first time I read those lines and I + + + align:start position:0% +the first time I read those lines and I +realized what it meant to be a movie + + align:start position:0% +realized what it meant to be a movie + + + align:start position:0% +realized what it meant to be a movie +critic or a literary critic think of + + align:start position:0% +critic or a literary critic think of + + + align:start position:0% +critic or a literary critic think of +what what what's implied by that if I + + align:start position:0% +what what what's implied by that if I + + + align:start position:0% +what what what's implied by that if I +were deprived + + align:start position:0% +were deprived + + + align:start position:0% +were deprived +of the pleasure of seeing budoo again + + align:start position:0% +of the pleasure of seeing budoo again + + + align:start position:0% +of the pleasure of seeing budoo again +for the rest of my life as if this would + + align:start position:0% +for the rest of my life as if this would + + + align:start position:0% +for the rest of my life as if this would +be a deprivation too horrible to + + align:start position:0% +be a deprivation too horrible to + + + align:start position:0% +be a deprivation too horrible to +contemplate right it made me realize my + + align:start position:0% +contemplate right it made me realize my + + + align:start position:0% +contemplate right it made me realize my +own vocation in a way uh if I were + + align:start position:0% +own vocation in a way uh if I were + + + align:start position:0% +own vocation in a way uh if I were +deprived of the pleasure of seeing budoo + + align:start position:0% +deprived of the pleasure of seeing budoo + + + align:start position:0% +deprived of the pleasure of seeing budoo +again for the rest of my days I would + + align:start position:0% +again for the rest of my days I would + + + align:start position:0% +again for the rest of my days I would +never forget that grass that dust and + + align:start position:0% +never forget that grass that dust and + + + align:start position:0% +never forget that grass that dust and +their relationship to the liberty of a + + align:start position:0% +their relationship to the liberty of a + + + align:start position:0% +their relationship to the liberty of a + the point of this exercise is to + + align:start position:0% + the point of this exercise is to + + + align:start position:0% + the point of this exercise is to +remind you of the immense power the + + align:start position:0% +remind you of the immense power the + + + align:start position:0% +remind you of the immense power the +potency of even a single camera move + + align:start position:0% +potency of even a single camera move + + + align:start position:0% +potency of even a single camera move +think what that 180 degree pan suggests + + align:start position:0% +think what that 180 degree pan suggests + + + align:start position:0% +think what that 180 degree pan suggests +as bazan brilliantly uh uh argues for us + + align:start position:0% +as bazan brilliantly uh uh argues for us + + + align:start position:0% +as bazan brilliantly uh uh argues for us +so the conclusion then is that the + + align:start position:0% +so the conclusion then is that the + + + align:start position:0% +so the conclusion then is that the +visual style of a film over certain + + align:start position:0% +visual style of a film over certain + + + align:start position:0% +visual style of a film over certain +films anyway can express a moral vision + + align:start position:0% +films anyway can express a moral vision + + + align:start position:0% +films anyway can express a moral vision +and by moral Vision I don't mean + + align:start position:0% +and by moral Vision I don't mean + + + align:start position:0% +and by moral Vision I don't mean +moralistic what's Mo what's what's + + align:start position:0% +moralistic what's Mo what's what's + + + align:start position:0% +moralistic what's Mo what's what's +didactically right and wrong but a + + align:start position:0% +didactically right and wrong but a + + + align:start position:0% +didactically right and wrong but a +vision having to do with the values and + + align:start position:0% +vision having to do with the values and + + + align:start position:0% +vision having to do with the values and +assumptions you make about the nature of + + align:start position:0% +assumptions you make about the nature of + + + align:start position:0% +assumptions you make about the nature of +the world there's a moral Vision + + align:start position:0% +the world there's a moral Vision + + + align:start position:0% +the world there's a moral Vision +implicit in the tentativeness the + + align:start position:0% +implicit in the tentativeness the + + + align:start position:0% +implicit in the tentativeness the +hesitancy the retarding impulse to to + + align:start position:0% +hesitancy the retarding impulse to to + + + align:start position:0% +hesitancy the retarding impulse to to +dwell and Linger on things in in the in + + align:start position:0% +dwell and Linger on things in in the in + + + align:start position:0% +dwell and Linger on things in in the in +renoir's camera and in the basic habits + + align:start position:0% +renoir's camera and in the basic habits + + + align:start position:0% +renoir's camera and in the basic habits +of of poetic realism that you will see + + align:start position:0% +of of poetic realism that you will see + + + align:start position:0% +of of poetic realism that you will see +brilliantly embodied in the film you're + + align:start position:0% +brilliantly embodied in the film you're + + + align:start position:0% +brilliantly embodied in the film you're +going to watch tonight Grand delusion \ No newline at end of file diff --git a/X2GJVlLC8bc.txt b/X2GJVlLC8bc.txt new file mode 100644 index 0000000000000000000000000000000000000000..6a94d5a1f80c0011112b0113f48627aa3d633d95 --- /dev/null +++ b/X2GJVlLC8bc.txt @@ -0,0 +1,219 @@ +align:start position:0% + +this in mind What technological + + align:start position:0% +this in mind What technological + + + align:start position:0% +this in mind What technological +responses do we have as Hughes mentioned + + align:start position:0% +responses do we have as Hughes mentioned + + + align:start position:0% +responses do we have as Hughes mentioned +um they're fairly limited um I have my + + align:start position:0% +um they're fairly limited um I have my + + + align:start position:0% +um they're fairly limited um I have my +research has been on vaccines and I've + + align:start position:0% +research has been on vaccines and I've + + + align:start position:0% +research has been on vaccines and I've +determined that they are not a first + + align:start position:0% +determined that they are not a first + + + align:start position:0% +determined that they are not a first +line of defense particularly for + + align:start position:0% +line of defense particularly for + + + align:start position:0% +line of defense particularly for +civilian populations they are useful uh + + align:start position:0% +civilian populations they are useful uh + + + align:start position:0% +civilian populations they are useful uh +to stabilize a situation after a attack + + align:start position:0% +to stabilize a situation after a attack + + + align:start position:0% +to stabilize a situation after a attack +has occurred for example once an agent + + align:start position:0% +has occurred for example once an agent + + + align:start position:0% +has occurred for example once an agent +has been identified it can be used a + + align:start position:0% +has been identified it can be used a + + + align:start position:0% +has been identified it can be used a +vaccine can be used to stem SE second + + align:start position:0% +vaccine can be used to stem SE second + + + align:start position:0% +vaccine can be used to stem SE second +waves of infection vaccines can be used + + align:start position:0% +waves of infection vaccines can be used + + + align:start position:0% +waves of infection vaccines can be used +to protect First Responders such as + + align:start position:0% +to protect First Responders such as + + + align:start position:0% +to protect First Responders such as +doctors nurses and emergency EMTs um + + align:start position:0% +doctors nurses and emergency EMTs um + + + align:start position:0% +doctors nurses and emergency EMTs um +this will allow the medical system to + + align:start position:0% +this will allow the medical system to + + + align:start position:0% +this will allow the medical system to +continue to function uh vaccines can + + align:start position:0% +continue to function uh vaccines can + + + align:start position:0% +continue to function uh vaccines can +also be used to permit re-entry of + + align:start position:0% +also be used to permit re-entry of + + + align:start position:0% +also be used to permit re-entry of +residents into an infected city um of + + align:start position:0% +residents into an infected city um of + + + align:start position:0% +residents into an infected city um of +course a successful biod defense program + + align:start position:0% +course a successful biod defense program + + + align:start position:0% +course a successful biod defense program +using vaccines is predicated on the + + align:start position:0% +using vaccines is predicated on the + + + align:start position:0% +using vaccines is predicated on the +availability of vaccines um and my + + align:start position:0% +availability of vaccines um and my + + + align:start position:0% +availability of vaccines um and my +research has demonstrated that we've had + + align:start position:0% +research has demonstrated that we've had + + + align:start position:0% +research has demonstrated that we've had +a lot of problems with vaccine Supply + + align:start position:0% +a lot of problems with vaccine Supply + + + align:start position:0% +a lot of problems with vaccine Supply +and Innovation particularly over the + + align:start position:0% +and Innovation particularly over the + + + align:start position:0% +and Innovation particularly over the +past 20 years and particularly for + + align:start position:0% +past 20 years and particularly for + + + align:start position:0% +past 20 years and particularly for +limited use vaccines which would be such + + align:start position:0% +limited use vaccines which would be such + + + align:start position:0% +limited use vaccines which would be such +as Anthrax and smallpox which is what we + + align:start position:0% +as Anthrax and smallpox which is what we + + + align:start position:0% +as Anthrax and smallpox which is what we +would need to mitigate an attack \ No newline at end of file diff --git a/X_HvnH9Mlwc.txt b/X_HvnH9Mlwc.txt new file mode 100644 index 0000000000000000000000000000000000000000..10e754d2be1484e42ed45cbc7a4bc37f5fe3cc7b --- /dev/null +++ b/X_HvnH9Mlwc.txt @@ -0,0 +1,7603 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +open courseware under a Creative Commons + + align:start position:0% +open courseware under a Creative Commons + + + align:start position:0% +open courseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu all right so uh we're in the + + align:start position:0% +ocw.mit.edu all right so uh we're in the + + + align:start position:0% +ocw.mit.edu all right so uh we're in the +middle of acids and + + align:start position:0% +middle of acids and + + + align:start position:0% +middle of acids and +bases and we're going to just finish up + + align:start position:0% +bases and we're going to just finish up + + + align:start position:0% +bases and we're going to just finish up +the handout from Monday starting uh + + align:start position:0% +the handout from Monday starting uh + + + align:start position:0% +the handout from Monday starting uh +first + + align:start position:0% + + + + align:start position:0% + +and we're talking about relative + + align:start position:0% +and we're talking about relative + + + align:start position:0% +and we're talking about relative +strengths of + + align:start position:0% + + + + align:start position:0% + +acids so if you have an equation such as + + align:start position:0% +acids so if you have an equation such as + + + align:start position:0% +acids so if you have an equation such as +this there is acid base chemistry going + + align:start position:0% +this there is acid base chemistry going + + + align:start position:0% +this there is acid base chemistry going +on in both + + align:start position:0% +on in both + + + align:start position:0% +on in both +directions so in the forward direction + + align:start position:0% +directions so in the forward direction + + + align:start position:0% +directions so in the forward direction +hno3 is acting as the acid it's giving + + align:start position:0% +hno3 is acting as the acid it's giving + + + align:start position:0% +hno3 is acting as the acid it's giving +up its hydrogen ion or proton to + + align:start position:0% +up its hydrogen ion or proton to + + + align:start position:0% +up its hydrogen ion or proton to +NH3 and when it gives it up it's forming + + align:start position:0% +NH3 and when it gives it up it's forming + + + align:start position:0% +NH3 and when it gives it up it's forming +its conjugate NH3 minus and when NH3 + + align:start position:0% +its conjugate NH3 minus and when NH3 + + + align:start position:0% +its conjugate NH3 minus and when NH3 +accepts a hydrogen atom or proton it's + + align:start position:0% +accepts a hydrogen atom or proton it's + + + align:start position:0% +accepts a hydrogen atom or proton it's +forming its conjugate acid + + align:start position:0% +forming its conjugate acid + + + align:start position:0% +forming its conjugate acid +nh4+ so that's what's happening in the + + align:start position:0% +nh4+ so that's what's happening in the + + + align:start position:0% +nh4+ so that's what's happening in the +forward direction of this reaction in + + align:start position:0% +forward direction of this reaction in + + + align:start position:0% +forward direction of this reaction in +the reverse direction of this reaction + + align:start position:0% +the reverse direction of this reaction + + + align:start position:0% +the reverse direction of this reaction +nh4+ is acting as the acid it's giving + + align:start position:0% +nh4+ is acting as the acid it's giving + + + align:start position:0% +nh4+ is acting as the acid it's giving +up a proton to NH3 minus when it gives + + align:start position:0% +up a proton to NH3 minus when it gives + + + align:start position:0% +up a proton to NH3 minus when it gives +up the proton it's forming NH3 the + + align:start position:0% +up the proton it's forming NH3 the + + + align:start position:0% +up the proton it's forming NH3 the +conjugate and when this accepts the + + align:start position:0% +conjugate and when this accepts the + + + align:start position:0% +conjugate and when this accepts the +hydrogen ion or proton it's forming its + + align:start position:0% +hydrogen ion or proton it's forming its + + + align:start position:0% +hydrogen ion or proton it's forming its +conjugate acid so in this direction this + + align:start position:0% +conjugate acid so in this direction this + + + align:start position:0% +conjugate acid so in this direction this +is the acid and in the reverse Direction + + align:start position:0% +is the acid and in the reverse Direction + + + align:start position:0% +is the acid and in the reverse Direction +This is the acid so you can predict + + align:start position:0% +This is the acid so you can predict + + + align:start position:0% +This is the acid so you can predict +something about the where the + + align:start position:0% +something about the where the + + + align:start position:0% +something about the where the +equilibrium lies whether it's to the + + align:start position:0% +equilibrium lies whether it's to the + + + align:start position:0% +equilibrium lies whether it's to the +right or the left if you have a big k or + + align:start position:0% +right or the left if you have a big k or + + + align:start position:0% +right or the left if you have a big k or +a small k for this reaction based on + + align:start position:0% +a small k for this reaction based on + + + align:start position:0% +a small k for this reaction based on +whether this is the stronger acid or + + align:start position:0% +whether this is the stronger acid or + + + align:start position:0% +whether this is the stronger acid or +this is the stronger acid so if this is + + align:start position:0% +this is the stronger acid so if this is + + + align:start position:0% +this is the stronger acid so if this is +a stronger acid the equilibrium will lie + + align:start position:0% +a stronger acid the equilibrium will lie + + + align:start position:0% +a stronger acid the equilibrium will lie +to the right if this is a stronger acid + + align:start position:0% +to the right if this is a stronger acid + + + align:start position:0% +to the right if this is a stronger acid +the equilibrium will lie to the left and + + align:start position:0% +the equilibrium will lie to the left and + + + align:start position:0% +the equilibrium will lie to the left and +so we can take a look at this and work + + align:start position:0% +so we can take a look at this and work + + + align:start position:0% +so we can take a look at this and work +out which is the stronger acid and where + + align:start position:0% +out which is the stronger acid and where + + + align:start position:0% +out which is the stronger acid and where +the equilibrium + + align:start position:0% +the equilibrium + + + align:start position:0% +the equilibrium +lies so here's the equilibrium constant + + align:start position:0% +lies so here's the equilibrium constant + + + align:start position:0% +lies so here's the equilibrium constant +for this reaction again it would be + + align:start position:0% +for this reaction again it would be + + + align:start position:0% +for this reaction again it would be +product + + align:start position:0% +product + + + align:start position:0% +product +over + + align:start position:0% +over + + + align:start position:0% +over +reactants and so to find this number we + + align:start position:0% +reactants and so to find this number we + + + align:start position:0% +reactants and so to find this number we +can work through it by getting + + align:start position:0% +can work through it by getting + + + align:start position:0% +can work through it by getting +information about the KA or acid + + align:start position:0% +information about the KA or acid + + + align:start position:0% +information about the KA or acid +ionization constant for this acid and + + align:start position:0% +ionization constant for this acid and + + + align:start position:0% +ionization constant for this acid and +for this + + align:start position:0% +for this + + + align:start position:0% +for this +acid so we can consider the reaction + + align:start position:0% +acid so we can consider the reaction + + + align:start position:0% +acid so we can consider the reaction +separately we can consider this acting + + align:start position:0% +separately we can consider this acting + + + align:start position:0% +separately we can consider this acting +as an acid and also this one so let's + + align:start position:0% +as an acid and also this one so let's + + + align:start position:0% +as an acid and also this one so let's +start here and consider the forward + + align:start position:0% +start here and consider the forward + + + align:start position:0% +start here and consider the forward +direction of the of the reaction and + + align:start position:0% +direction of the of the reaction and + + + align:start position:0% +direction of the of the reaction and +consider how good an acid NH uh n hno3 + + align:start position:0% + + + + align:start position:0% + +is so you all should be able to write + + align:start position:0% +is so you all should be able to write + + + align:start position:0% +is so you all should be able to write +reactions of acid in water or bases in + + align:start position:0% +reactions of acid in water or bases in + + + align:start position:0% +reactions of acid in water or bases in +water and figure out what the products + + align:start position:0% +water and figure out what the products + + + align:start position:0% +water and figure out what the products +are going to be of that so if we have + + align:start position:0% +are going to be of that so if we have + + + align:start position:0% +are going to be of that so if we have +NH3 in + + align:start position:0% +NH3 in + + + align:start position:0% +NH3 in +water then we're going to be forming + + align:start position:0% +water then we're going to be forming + + + align:start position:0% +water then we're going to be forming +hydronium ion and the conjugate base of + + align:start position:0% +hydronium ion and the conjugate base of + + + align:start position:0% +hydronium ion and the conjugate base of +this conjugate acid here + + align:start position:0% +this conjugate acid here + + + align:start position:0% +this conjugate acid here +and then we can write a Ka and it's a Ka + + align:start position:0% +and then we can write a Ka and it's a Ka + + + align:start position:0% +and then we can write a Ka and it's a Ka +because we're talking about an acid in + + align:start position:0% +because we're talking about an acid in + + + align:start position:0% +because we're talking about an acid in +water so the KA is going to be equal to + + align:start position:0% +water so the KA is going to be equal to + + + align:start position:0% +water so the KA is going to be equal to +the products over the reactants and here + + align:start position:0% +the products over the reactants and here + + + align:start position:0% +the products over the reactants and here +water isn't included because it's the + + align:start position:0% +water isn't included because it's the + + + align:start position:0% +water isn't included because it's the +solvent and its concentration really + + align:start position:0% +solvent and its concentration really + + + align:start position:0% +solvent and its concentration really +isn't changing through the course of + + align:start position:0% +isn't changing through the course of + + + align:start position:0% +isn't changing through the course of +this reaction and we can look up uh an + + align:start position:0% +this reaction and we can look up uh an + + + align:start position:0% +this reaction and we can look up uh an +equilibrium uh constant for this acid + + align:start position:0% +equilibrium uh constant for this acid + + + align:start position:0% +equilibrium uh constant for this acid +and that's 20 so is that a strong acid + + align:start position:0% +and that's 20 so is that a strong acid + + + align:start position:0% +and that's 20 so is that a strong acid +or a weak acid + + align:start position:0% + + + + align:start position:0% + +how did we Define strong acid last + + align:start position:0% +how did we Define strong acid last + + + align:start position:0% +how did we Define strong acid last +time it was a Ka if is greater than one + + align:start position:0% +time it was a Ka if is greater than one + + + align:start position:0% +time it was a Ka if is greater than one +so 20 is greater than one so this is a + + align:start position:0% +so 20 is greater than one so this is a + + + align:start position:0% +so 20 is greater than one so this is a +strong + + align:start position:0% + + + + align:start position:0% + +acid now we can do the same thing for + + align:start position:0% +acid now we can do the same thing for + + + align:start position:0% +acid now we can do the same thing for +the reverse Direction in the reverse + + align:start position:0% +the reverse Direction in the reverse + + + align:start position:0% +the reverse Direction in the reverse +Direction the acid is + + align:start position:0% +Direction the acid is + + + align:start position:0% +Direction the acid is +nh4+ so we can write + + align:start position:0% +nh4+ so we can write + + + align:start position:0% +nh4+ so we can write +nh4+ in water and that would go to + + align:start position:0% +nh4+ in water and that would go to + + + align:start position:0% +nh4+ in water and that would go to +hydronium ions and the conjugate of this + + align:start position:0% +hydronium ions and the conjugate of this + + + align:start position:0% +hydronium ions and the conjugate of this +acid which is + + align:start position:0% +acid which is + + + align:start position:0% +acid which is +NH3 we can write out a Ka expression for + + align:start position:0% +NH3 we can write out a Ka expression for + + + align:start position:0% +NH3 we can write out a Ka expression for +this again it would be pro products over + + align:start position:0% +this again it would be pro products over + + + align:start position:0% +this again it would be pro products over +reactants and here the KA which could be + + align:start position:0% +reactants and here the KA which could be + + + align:start position:0% +reactants and here the KA which could be +looked up is 5.6 * 10us 10 so is that a + + align:start position:0% +looked up is 5.6 * 10us 10 so is that a + + + align:start position:0% +looked up is 5.6 * 10us 10 so is that a +strong or weak + + align:start position:0% +strong or weak + + + align:start position:0% +strong or weak +acid that's a weak acid so the KA is + + align:start position:0% +acid that's a weak acid so the KA is + + + align:start position:0% +acid that's a weak acid so the KA is +quite a bit less than one so already we + + align:start position:0% +quite a bit less than one so already we + + + align:start position:0% +quite a bit less than one so already we +can predict that for this over all + + align:start position:0% +can predict that for this over all + + + align:start position:0% +can predict that for this over all +reaction it will lie to the right this + + align:start position:0% +reaction it will lie to the right this + + + align:start position:0% +reaction it will lie to the right this +is a much stronger acid than this one + + align:start position:0% +is a much stronger acid than this one + + + align:start position:0% +is a much stronger acid than this one +but we can prove that that's true by + + align:start position:0% +but we can prove that that's true by + + + align:start position:0% +but we can prove that that's true by +using these two Ka values to get the + + align:start position:0% +using these two Ka values to get the + + + align:start position:0% +using these two Ka values to get the +overall equilibrium constant for this + + align:start position:0% +overall equilibrium constant for this + + + align:start position:0% +overall equilibrium constant for this +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +here so if we took those two individual + + align:start position:0% +here so if we took those two individual + + + align:start position:0% +here so if we took those two individual +reactions that we wrote out and uh + + align:start position:0% +reactions that we wrote out and uh + + + align:start position:0% +reactions that we wrote out and uh +subtract them we can get our overall + + align:start position:0% +subtract them we can get our overall + + + align:start position:0% +subtract them we can get our overall +expression uh for the reaction and if we + + align:start position:0% +expression uh for the reaction and if we + + + align:start position:0% +expression uh for the reaction and if we +subtract them then we can come up with + + align:start position:0% +subtract them then we can come up with + + + align:start position:0% +subtract them then we can come up with +the K by dividing the uh the KA from + + align:start position:0% +the K by dividing the uh the KA from + + + align:start position:0% +the K by dividing the uh the KA from +each other so remember we talked about K + + align:start position:0% +each other so remember we talked about K + + + align:start position:0% +each other so remember we talked about K +if you add together you multiply if you + + align:start position:0% +if you add together you multiply if you + + + align:start position:0% +if you add together you multiply if you +subtract reactions you can divide and so + + align:start position:0% +subtract reactions you can divide and so + + + align:start position:0% +subtract reactions you can divide and so +we can prove that this is true that if + + align:start position:0% +we can prove that this is true that if + + + align:start position:0% +we can prove that this is true that if +we have the KA up here and the K down + + align:start position:0% +we have the KA up here and the K down + + + align:start position:0% +we have the KA up here and the K down +here it will cancel to form uh the + + align:start position:0% +here it will cancel to form uh the + + + align:start position:0% +here it will cancel to form uh the +equilibrium expression for the overall + + align:start position:0% +equilibrium expression for the overall + + + align:start position:0% +equilibrium expression for the overall +reaction and we can substitute our ka's + + align:start position:0% +reaction and we can substitute our ka's + + + align:start position:0% +reaction and we can substitute our ka's +in 20 over 5.6 * + + align:start position:0% +in 20 over 5.6 * + + + align:start position:0% +in 20 over 5.6 * +10-10 and we get a k for the overall + + align:start position:0% +10-10 and we get a k for the overall + + + align:start position:0% +10-10 and we get a k for the overall +reaction of 3.6 * 10 10 which is an + + align:start position:0% +reaction of 3.6 * 10 10 which is an + + + align:start position:0% +reaction of 3.6 * 10 10 which is an +enormous number and so this would lie + + align:start position:0% +enormous number and so this would lie + + + align:start position:0% +enormous number and so this would lie +very very far to the right this is a + + align:start position:0% +very very far to the right this is a + + + align:start position:0% +very very far to the right this is a +much much stronger acid than + + align:start position:0% +much much stronger acid than + + + align:start position:0% +much much stronger acid than +nh4+ so if you know something if you + + align:start position:0% +nh4+ so if you know something if you + + + align:start position:0% +nh4+ so if you know something if you +have acid base on both sides of the + + align:start position:0% +have acid base on both sides of the + + + align:start position:0% +have acid base on both sides of the +equilibrium you know about the strengths + + align:start position:0% +equilibrium you know about the strengths + + + align:start position:0% +equilibrium you know about the strengths +you could predict where the equilibrium + + align:start position:0% +you could predict where the equilibrium + + + align:start position:0% +you could predict where the equilibrium +of an overall reaction is going to + + align:start position:0% + + + + align:start position:0% + +lie all right + + align:start position:0% +lie all right + + + align:start position:0% +lie all right +so this is still on the handout from + + align:start position:0% +so this is still on the handout from + + + align:start position:0% +so this is still on the handout from +from Monday and mentioned that there are + + align:start position:0% +from Monday and mentioned that there are + + + align:start position:0% +from Monday and mentioned that there are +five different types of acid-based + + align:start position:0% +five different types of acid-based + + + align:start position:0% +five different types of acid-based +problems that you're going to encounter + + align:start position:0% +problems that you're going to encounter + + + align:start position:0% +problems that you're going to encounter +in this unit and there uh there's + + align:start position:0% +in this unit and there uh there's + + + align:start position:0% +in this unit and there uh there's +problems of salt and water which we're + + align:start position:0% +problems of salt and water which we're + + + align:start position:0% +problems of salt and water which we're +going to see today break down to a weak + + align:start position:0% +going to see today break down to a weak + + + align:start position:0% +going to see today break down to a weak +acid or a weak base in water problem so + + align:start position:0% +acid or a weak base in water problem so + + + align:start position:0% +acid or a weak base in water problem so +it's really not a different type of + + align:start position:0% +it's really not a different type of + + + align:start position:0% +it's really not a different type of +problem at all so there's weak acid and + + align:start position:0% +problem at all so there's weak acid and + + + align:start position:0% +problem at all so there's weak acid and +water weak base strong acid strong base + + align:start position:0% +water weak base strong acid strong base + + + align:start position:0% +water weak base strong acid strong base +and they're buffer problems and when we + + align:start position:0% +and they're buffer problems and when we + + + align:start position:0% +and they're buffer problems and when we +do titrations it'll seem like that's a + + align:start position:0% +do titrations it'll seem like that's a + + + align:start position:0% +do titrations it'll seem like that's a +different kind but it also breaks down + + align:start position:0% +different kind but it also breaks down + + + align:start position:0% +different kind but it also breaks down +into these categories so one trick that + + align:start position:0% +into these categories so one trick that + + + align:start position:0% +into these categories so one trick that +I've learned from teaching this a number + + align:start position:0% +I've learned from teaching this a number + + + align:start position:0% +I've learned from teaching this a number +of years is to get people starting to + + align:start position:0% +of years is to get people starting to + + + align:start position:0% +of years is to get people starting to +think about what type of problem it is + + align:start position:0% +think about what type of problem it is + + + align:start position:0% +think about what type of problem it is +whenever they see it and figuring out + + align:start position:0% +whenever they see it and figuring out + + + align:start position:0% +whenever they see it and figuring out +then they know how to address that + + align:start position:0% +then they know how to address that + + + align:start position:0% +then they know how to address that +problem so always be thinking about what + + align:start position:0% +problem so always be thinking about what + + + align:start position:0% +problem so always be thinking about what +type of problem is this and so how do I + + align:start position:0% +type of problem is this and so how do I + + + align:start position:0% +type of problem is this and so how do I +go about solving it so we're going to + + align:start position:0% +go about solving it so we're going to + + + align:start position:0% +go about solving it so we're going to +look at the first number one here a week + + align:start position:0% +look at the first number one here a week + + + align:start position:0% +look at the first number one here a week +acid and water + + align:start position:0% +acid and water + + + align:start position:0% +acid and water +problem and the weak acid that I pick to + + align:start position:0% +problem and the weak acid that I pick to + + + align:start position:0% +problem and the weak acid that I pick to +look at is Vitamin C so in this + + align:start position:0% +look at is Vitamin C so in this + + + align:start position:0% +look at is Vitamin C so in this +particular problem we are going to ask + + align:start position:0% +particular problem we are going to ask + + + align:start position:0% +particular problem we are going to ask +um what the pH would be if I take this + + align:start position:0% +um what the pH would be if I take this + + + align:start position:0% +um what the pH would be if I take this +vitamin C tablet and it's a 50 mgram + + align:start position:0% +vitamin C tablet and it's a 50 mgram + + + align:start position:0% +vitamin C tablet and it's a 50 mgram +tablet and put it into uh 100 + + align:start position:0% +tablet and put it into uh 100 + + + align:start position:0% +tablet and put it into uh 100 +milliliters uh of water + + align:start position:0% +milliliters uh of water + + + align:start position:0% +milliliters uh of water +and usually when you try to swallow + + align:start position:0% +and usually when you try to swallow + + + align:start position:0% +and usually when you try to swallow +vitamin tablets you try not to dissolve + + align:start position:0% +vitamin tablets you try not to dissolve + + + align:start position:0% +vitamin tablets you try not to dissolve +them um but if we did then we could look + + align:start position:0% +them um but if we did then we could look + + + align:start position:0% +them um but if we did then we could look +at the pH I've discovered though I + + align:start position:0% +at the pH I've discovered though I + + + align:start position:0% +at the pH I've discovered though I +actually tried to do the calculations + + align:start position:0% +actually tried to do the calculations + + + align:start position:0% +actually tried to do the calculations +and do the actual experiment one year + + align:start position:0% +and do the actual experiment one year + + + align:start position:0% +and do the actual experiment one year +and discovered that these vitamin C + + align:start position:0% +and discovered that these vitamin C + + + align:start position:0% +and discovered that these vitamin C +tablets are coated really well you + + align:start position:0% +tablets are coated really well you + + + align:start position:0% +tablets are coated really well you +cannot get them to dissolve very easily + + align:start position:0% +cannot get them to dissolve very easily + + + align:start position:0% +cannot get them to dissolve very easily +and so uh that's because you don't want + + align:start position:0% +and so uh that's because you don't want + + + align:start position:0% +and so uh that's because you don't want +the bad taste in your mouth so Nature's + + align:start position:0% +the bad taste in your mouth so Nature's + + + align:start position:0% +the bad taste in your mouth so Nature's +Bounty if you don't want this tablet to + + align:start position:0% +Bounty if you don't want this tablet to + + + align:start position:0% +Bounty if you don't want this tablet to +dissolve in your mouth before you + + align:start position:0% +dissolve in your mouth before you + + + align:start position:0% +dissolve in your mouth before you +swallow it I guarantee it won't you have + + align:start position:0% +swallow it I guarantee it won't you have + + + align:start position:0% +swallow it I guarantee it won't you have +to go to extreme lengths to get this to + + align:start position:0% +to go to extreme lengths to get this to + + + align:start position:0% +to go to extreme lengths to get this to +dissolve in your mouth so we can't + + align:start position:0% +dissolve in your mouth so we can't + + + align:start position:0% +dissolve in your mouth so we can't +actually measure the pH of this because + + align:start position:0% +actually measure the pH of this because + + + align:start position:0% +actually measure the pH of this because +it's not going to uh dissolve the cating + + align:start position:0% +it's not going to uh dissolve the cating + + + align:start position:0% +it's not going to uh dissolve the cating +is pretty good but we can do the + + align:start position:0% +is pretty good but we can do the + + + align:start position:0% +is pretty good but we can do the +calculations if the coding was less good + + align:start position:0% +calculations if the coding was less good + + + align:start position:0% +calculations if the coding was less good +uh What the pH of that would be all + + align:start position:0% + + + + align:start position:0% + +right so the first thing we need to know + + align:start position:0% +right so the first thing we need to know + + + align:start position:0% +right so the first thing we need to know +is marity + + align:start position:0% + + + + align:start position:0% + +and so you can do this uh + + align:start position:0% +and so you can do this uh + + + align:start position:0% +and so you can do this uh +calculation you uh know the number of + + align:start position:0% +calculation you uh know the number of + + + align:start position:0% +calculation you uh know the number of +milligrams convert to grams look up the + + align:start position:0% +milligrams convert to grams look up the + + + align:start position:0% +milligrams convert to grams look up the +molecular weight uh calculate how many + + align:start position:0% +molecular weight uh calculate how many + + + align:start position:0% +molecular weight uh calculate how many +moles that is and then that number of + + align:start position:0% +moles that is and then that number of + + + align:start position:0% +moles that is and then that number of +moles in your uh 0.1 lers or 100 + + align:start position:0% +moles in your uh 0.1 lers or 100 + + + align:start position:0% +moles in your uh 0.1 lers or 100 +milligrams and you can get the marity of + + align:start position:0% +milligrams and you can get the marity of + + + align:start position:0% +milligrams and you can get the marity of +a vitamin C tablet in uh in 100 + + align:start position:0% +a vitamin C tablet in uh in 100 + + + align:start position:0% +a vitamin C tablet in uh in 100 +milliliters of + + align:start position:0% +milliliters of + + + align:start position:0% +milliliters of +water then you would need to write the + + align:start position:0% +water then you would need to write the + + + align:start position:0% +water then you would need to write the +equation for a weak acid in water + + align:start position:0% +equation for a weak acid in water + + + align:start position:0% +equation for a weak acid in water +problem and so here's our weak acid in + + align:start position:0% +problem and so here's our weak acid in + + + align:start position:0% +problem and so here's our weak acid in +water it's forming hydronium ions and a + + align:start position:0% +water it's forming hydronium ions and a + + + align:start position:0% +water it's forming hydronium ions and a +conjugate + + align:start position:0% + + + + align:start position:0% + +base so then you can set this up and + + align:start position:0% +base so then you can set this up and + + + align:start position:0% +base so then you can set this up and +figure out what happens as uh initially + + align:start position:0% +figure out what happens as uh initially + + + align:start position:0% +figure out what happens as uh initially +the change and then what the + + align:start position:0% +the change and then what the + + + align:start position:0% +the change and then what the +concentration would be at equilibrium so + + align:start position:0% +concentration would be at equilibrium so + + + align:start position:0% +concentration would be at equilibrium so +in the beginning you just have this + + align:start position:0% +in the beginning you just have this + + + align:start position:0% +in the beginning you just have this +marity the point + + align:start position:0% +marity the point + + + align:start position:0% +marity the point +0284 molar solution and you don't have + + align:start position:0% +0284 molar solution and you don't have + + + align:start position:0% +0284 molar solution and you don't have +any of these initially the change would + + align:start position:0% +any of these initially the change would + + + align:start position:0% +any of these initially the change would +be minus X and then plus X Plus X so at + + align:start position:0% +be minus X and then plus X Plus X so at + + + align:start position:0% +be minus X and then plus X Plus X so at +equilibrium we're + + align:start position:0% +equilibrium we're + + + align:start position:0% +equilibrium we're +0284 - x and again plus + + align:start position:0% +0284 - x and again plus + + + align:start position:0% +0284 - x and again plus +X so now to solve for x which is what we + + align:start position:0% +X so now to solve for x which is what we + + + align:start position:0% +X so now to solve for x which is what we +want to solve we want to find out pH and + + align:start position:0% +want to solve we want to find out pH and + + + align:start position:0% +want to solve we want to find out pH and +pH is the minus log of the hydronium ion + + align:start position:0% +pH is the minus log of the hydronium ion + + + align:start position:0% +pH is the minus log of the hydronium ion +concentration + + align:start position:0% +concentration + + + align:start position:0% +concentration +so we need to find X to be able to find + + align:start position:0% +so we need to find X to be able to find + + + align:start position:0% +so we need to find X to be able to find +pH and to get X we can do that if we + + align:start position:0% +pH and to get X we can do that if we + + + align:start position:0% +pH and to get X we can do that if we +know the KA for the solution write out + + align:start position:0% +know the KA for the solution write out + + + align:start position:0% +know the KA for the solution write out +the expression hydronium ion conjugate + + align:start position:0% +the expression hydronium ion conjugate + + + align:start position:0% +the expression hydronium ion conjugate +base over acid we're leaving out the + + align:start position:0% +base over acid we're leaving out the + + + align:start position:0% +base over acid we're leaving out the +water again so that would be equal to + + align:start position:0% +water again so that would be equal to + + + align:start position:0% +water again so that would be equal to +x^2 + + align:start position:0% +x^2 + + + align:start position:0% +x^2 +0284 - + + align:start position:0% + + + + align:start position:0% + +x so now we can try an assumption and + + align:start position:0% +x so now we can try an assumption and + + + align:start position:0% +x so now we can try an assumption and +and this will be useful to you on exams + + align:start position:0% +and this will be useful to you on exams + + + align:start position:0% +and this will be useful to you on exams +so first you can try to say what if x + + align:start position:0% +so first you can try to say what if x + + + align:start position:0% +so first you can try to say what if x +was really small what if x was much much + + align:start position:0% +was really small what if x was much much + + + align:start position:0% +was really small what if x was much much +smaller than this + + align:start position:0% +smaller than this + + + align:start position:0% +smaller than this +0284 then this term just collapses into + + align:start position:0% +0284 then this term just collapses into + + + align:start position:0% +0284 then this term just collapses into +the number so you can make that + + align:start position:0% +the number so you can make that + + + align:start position:0% +the number so you can make that +assumption and try it and see if it + + align:start position:0% +assumption and try it and see if it + + + align:start position:0% +assumption and try it and see if it +works and I'll tell you what the rule + + align:start position:0% +works and I'll tell you what the rule + + + align:start position:0% +works and I'll tell you what the rule +will be to check that out so if we try + + align:start position:0% +will be to check that out so if we try + + + align:start position:0% +will be to check that out so if we try +the Assumption then uh we have just X + + align:start position:0% +the Assumption then uh we have just X + + + align:start position:0% +the Assumption then uh we have just X +squar over this number that's easier to + + align:start position:0% +squar over this number that's easier to + + + align:start position:0% +squar over this number that's easier to +solve + + align:start position:0% +solve + + + align:start position:0% +solve +and we can solve for + + align:start position:0% +and we can solve for + + + align:start position:0% +and we can solve for +x and here x is + + align:start position:0% +x and here x is + + + align:start position:0% +x and here x is +0.151 and I'm carrying an extra + + align:start position:0% +0.151 and I'm carrying an extra + + + align:start position:0% +0.151 and I'm carrying an extra +significant + + align:start position:0% +significant + + + align:start position:0% +significant +figure and then we can go and check is + + align:start position:0% +figure and then we can go and check is + + + align:start position:0% +figure and then we can go and check is +this true that that is in fact much + + align:start position:0% +this true that that is in fact much + + + align:start position:0% +this true that that is in fact much +smaller than this and the rule that + + align:start position:0% +smaller than this and the rule that + + + align:start position:0% +smaller than this and the rule that +we'll use is 5% so you can uh calculate + + align:start position:0% +we'll use is 5% so you can uh calculate + + + align:start position:0% +we'll use is 5% so you can uh calculate +whether the number is 5% take X over + + align:start position:0% +whether the number is 5% take X over + + + align:start position:0% +whether the number is 5% take X over +your initial number times 100 % in this + + align:start position:0% +your initial number times 100 % in this + + + align:start position:0% +your initial number times 100 % in this +case it was + + align:start position:0% +case it was + + + align:start position:0% +case it was +5.3% which is more than five and so you + + align:start position:0% +5.3% which is more than five and so you + + + align:start position:0% +5.3% which is more than five and so you +should use the quadratic equation to + + align:start position:0% +should use the quadratic equation to + + + align:start position:0% +should use the quadratic equation to +solve for x so most of you normally use + + align:start position:0% +solve for x so most of you normally use + + + align:start position:0% +solve for x so most of you normally use +calculators which there's no problem in + + align:start position:0% +calculators which there's no problem in + + + align:start position:0% +calculators which there's no problem in +doing quadratic but of course the + + align:start position:0% +doing quadratic but of course the + + + align:start position:0% +doing quadratic but of course the +calculators we use on the exams uh are + + align:start position:0% +calculators we use on the exams uh are + + + align:start position:0% +calculators we use on the exams uh are +not so amenable to doing this so I + + align:start position:0% +not so amenable to doing this so I + + + align:start position:0% +not so amenable to doing this so I +suggest on an exam you always try the + + align:start position:0% +suggest on an exam you always try the + + + align:start position:0% +suggest on an exam you always try the +assumption that you can make it a + + align:start position:0% +assumption that you can make it a + + + align:start position:0% +assumption that you can make it a +simpler problem to save yourself time + + align:start position:0% +simpler problem to save yourself time + + + align:start position:0% +simpler problem to save yourself time +so the rule is 5% has to be less than + + align:start position:0% +so the rule is 5% has to be less than + + + align:start position:0% +so the rule is 5% has to be less than +5% so I'll just mention that the book + + align:start position:0% +5% so I'll just mention that the book + + + align:start position:0% +5% so I'll just mention that the book +talks about this expression and refers + + align:start position:0% +talks about this expression and refers + + + align:start position:0% +talks about this expression and refers +to a percent ionized or percent T + + align:start position:0% +to a percent ionized or percent T + + + align:start position:0% +to a percent ionized or percent T +protonated So this equation which is + + align:start position:0% +protonated So this equation which is + + + align:start position:0% +protonated So this equation which is +really X over the uh the number minus + + align:start position:0% +really X over the uh the number minus + + + align:start position:0% +really X over the uh the number minus +the initial marity minus X is how much + + align:start position:0% +the initial marity minus X is how much + + + align:start position:0% +the initial marity minus X is how much +you've gone to that side of the equation + + align:start position:0% +you've gone to that side of the equation + + + align:start position:0% +you've gone to that side of the equation +how much you've deprotonated what the + + align:start position:0% +how much you've deprotonated what the + + + align:start position:0% +how much you've deprotonated what the +percent ionization is so you'll see + + align:start position:0% +percent ionization is so you'll see + + + align:start position:0% +percent ionization is so you'll see +those terms uh in the problem set and + + align:start position:0% +those terms uh in the problem set and + + + align:start position:0% +those terms uh in the problem set and +and in the + + align:start position:0% +and in the + + + align:start position:0% +and in the +book so if you use the quadratic + + align:start position:0% +book so if you use the quadratic + + + align:start position:0% +book so if you use the quadratic +equation then you get + + align:start position:0% + + + + align:start position:0% + +0.147 and uh we're still carrying an + + align:start position:0% +0.147 and uh we're still carrying an + + + align:start position:0% +0.147 and uh we're still carrying an +extra significant figure that's really + + align:start position:0% +extra significant figure that's really + + + align:start position:0% +extra significant figure that's really +two significant figures the KA just had + + align:start position:0% +two significant figures the KA just had + + + align:start position:0% +two significant figures the KA just had +two significant figures that was given + + align:start position:0% +two significant figures that was given + + + align:start position:0% +two significant figures that was given +and so if we uh now solve so this is x + + align:start position:0% +and so if we uh now solve so this is x + + + align:start position:0% +and so if we uh now solve so this is x +when X was the hydronium ion + + align:start position:0% +when X was the hydronium ion + + + align:start position:0% +when X was the hydronium ion +concentration so pH is minus log of the + + align:start position:0% +concentration so pH is minus log of the + + + align:start position:0% +concentration so pH is minus log of the +hydronium ion concentration which would + + align:start position:0% +hydronium ion concentration which would + + + align:start position:0% +hydronium ion concentration which would +be 2. uh + + align:start position:0% +be 2. uh + + + align:start position:0% +be 2. uh +83 and since this was really two + + align:start position:0% +83 and since this was really two + + + align:start position:0% +83 and since this was really two +significant figures now you have two + + align:start position:0% +significant figures now you have two + + + align:start position:0% +significant figures now you have two +significant figures after the decimal + + align:start position:0% +significant figures after the decimal + + + align:start position:0% +significant figures after the decimal +point so uh that would be the correct + + align:start position:0% +point so uh that would be the correct + + + align:start position:0% +point so uh that would be the correct +significant figure uh number for this so + + align:start position:0% +significant figure uh number for this so + + + align:start position:0% +significant figure uh number for this so +remember this 5% rule to make your life + + align:start position:0% +remember this 5% rule to make your life + + + align:start position:0% +remember this 5% rule to make your life +easier and also in all of these problems + + align:start position:0% +easier and also in all of these problems + + + align:start position:0% +easier and also in all of these problems +you want to pay attention to the + + align:start position:0% +you want to pay attention to the + + + align:start position:0% +you want to pay attention to the +significant figures again the rules for + + align:start position:0% +significant figures again the rules for + + + align:start position:0% +significant figures again the rules for +logs and significant figures + + align:start position:0% +logs and significant figures + + + align:start position:0% +logs and significant figures +uh are are a little complicated and and + + align:start position:0% +uh are are a little complicated and and + + + align:start position:0% +uh are are a little complicated and and +require some some + + align:start position:0% +require some some + + + align:start position:0% +require some some +thought all right so that's that's weak + + align:start position:0% +thought all right so that's that's weak + + + align:start position:0% +thought all right so that's that's weak +acid in water type problem and the weak + + align:start position:0% +acid in water type problem and the weak + + + align:start position:0% +acid in water type problem and the weak +base is going to be very very similar to + + align:start position:0% +base is going to be very very similar to + + + align:start position:0% +base is going to be very very similar to +that and so today we're going to be + + align:start position:0% +that and so today we're going to be + + + align:start position:0% +that and so today we're going to be +going on and talking about weak bases + + align:start position:0% +going on and talking about weak bases + + + align:start position:0% +going on and talking about weak bases +we're going to talk about Salt Solutions + + align:start position:0% +we're going to talk about Salt Solutions + + + align:start position:0% +we're going to talk about Salt Solutions +and I'll try to prove to you that salt + + align:start position:0% +and I'll try to prove to you that salt + + + align:start position:0% +and I'll try to prove to you that salt +solution problems just break down to + + align:start position:0% +solution problems just break down to + + + align:start position:0% +solution problems just break down to +weak acid problems and weak base + + align:start position:0% +weak acid problems and weak base + + + align:start position:0% +weak acid problems and weak base +problems + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +C no that's the same + + align:start position:0% + + + + align:start position:0% + +X it's just smaller than it's just a + + align:start position:0% +X it's just smaller than it's just a + + + align:start position:0% +X it's just smaller than it's just a +question of is it's smaller than the + + align:start position:0% +question of is it's smaller than the + + + align:start position:0% +question of is it's smaller than the +number so back here it's not that it's + + align:start position:0% +number so back here it's not that it's + + + align:start position:0% +number so back here it's not that it's +it's incredibly small number it's just + + align:start position:0% +it's incredibly small number it's just + + + align:start position:0% +it's incredibly small number it's just +within the significant figures smaller + + align:start position:0% +within the significant figures smaller + + + align:start position:0% +within the significant figures smaller +than this number so that if you + + align:start position:0% +than this number so that if you + + + align:start position:0% +than this number so that if you +subtracted it from that number it + + align:start position:0% +subtracted it from that number it + + + align:start position:0% +subtracted it from that number it +wouldn't really make any + + align:start position:0% + + + + align:start position:0% + +difference this + + align:start position:0% + + + + align:start position:0% + +one yeah so th this is the the + + align:start position:0% +one yeah so th this is the the + + + align:start position:0% +one yeah so th this is the the +assumption that X the number X is going + + align:start position:0% +assumption that X the number X is going + + + align:start position:0% +assumption that X the number X is going +to be enough smaller than 028 + + align:start position:0% +to be enough smaller than 028 + + + align:start position:0% +to be enough smaller than 028 +that if you subtracted X from that + + align:start position:0% +that if you subtracted X from that + + + align:start position:0% +that if you subtracted X from that +number you'd still get that + + align:start position:0% + + + + align:start position:0% + +number yeah so here you're getting plus + + align:start position:0% +number yeah so here you're getting plus + + + align:start position:0% +number yeah so here you're getting plus +X you're forming this amount of + + align:start position:0% +X you're forming this amount of + + + align:start position:0% +X you're forming this amount of +hydronium ion this amount of the + + align:start position:0% +hydronium ion this amount of the + + + align:start position:0% +hydronium ion this amount of the +conjugate and that's the same amount + + align:start position:0% +conjugate and that's the same amount + + + align:start position:0% +conjugate and that's the same amount +that's forming here that what you're + + align:start position:0% +that's forming here that what you're + + + align:start position:0% +that's forming here that what you're +taking away from your initial over here + + align:start position:0% +taking away from your initial over here + + + align:start position:0% +taking away from your initial over here +so it is the same X so you're not you're + + align:start position:0% +so it is the same X so you're not you're + + + align:start position:0% +so it is the same X so you're not you're +not really saying that this is infantes + + align:start position:0% +not really saying that this is infantes + + + align:start position:0% +not really saying that this is infantes +small number you're just saying that + + align:start position:0% +small number you're just saying that + + + align:start position:0% +small number you're just saying that +it's + + align:start position:0% +it's + + + align:start position:0% +it's +smaller than this to to the degree that + + align:start position:0% +smaller than this to to the degree that + + + align:start position:0% +smaller than this to to the degree that +it's not playing a big it's not changing + + align:start position:0% +it's not playing a big it's not changing + + + align:start position:0% +it's not playing a big it's not changing +this very much so you don't have to + + align:start position:0% +this very much so you don't have to + + + align:start position:0% +this very much so you don't have to +actually do that subtraction and so the + + align:start position:0% +actually do that subtraction and so the + + + align:start position:0% +actually do that subtraction and so the +rule we use for that is + + align:start position:0% + + + + align:start position:0% + +5% okay so again there are these types + + align:start position:0% +5% okay so again there are these types + + + align:start position:0% +5% okay so again there are these types +of problems and now we're going to look + + align:start position:0% +of problems and now we're going to look + + + align:start position:0% +of problems and now we're going to look +at a weak base + + align:start position:0% + + + + align:start position:0% + +problem okay so let's look at a weak + + align:start position:0% +problem okay so let's look at a weak + + + align:start position:0% +problem okay so let's look at a weak +based problem I need better chalk than + + align:start position:0% + + + + align:start position:0% + +that all right so weak base in + + align:start position:0% + + + + align:start position:0% + +water so if we have + + align:start position:0% +water so if we have + + + align:start position:0% +water so if we have +NH3 plus + + align:start position:0% +NH3 plus + + + align:start position:0% +NH3 plus +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +water it will go to the conjugate of NH3 + + align:start position:0% +water it will go to the conjugate of NH3 + + + align:start position:0% +water it will go to the conjugate of NH3 +which is NH + + align:start position:0% + + + + align:start position:0% + +4+ and hydroxide + + align:start position:0% + + + + align:start position:0% + +ion so if you're talking about a weak + + align:start position:0% +ion so if you're talking about a weak + + + align:start position:0% +ion so if you're talking about a weak +base in water + + align:start position:0% +base in water + + + align:start position:0% +base in water +problem you're going to expect to see + + align:start position:0% +problem you're going to expect to see + + + align:start position:0% +problem you're going to expect to see +hydronium ion on the other side and this + + align:start position:0% +hydronium ion on the other side and this + + + align:start position:0% +hydronium ion on the other side and this +is just a check that you want to make + + align:start position:0% +is just a check that you want to make + + + align:start position:0% +is just a check that you want to make +sure you're asking yourself as you're + + align:start position:0% +sure you're asking yourself as you're + + + align:start position:0% +sure you're asking yourself as you're +doing these problems if you write the + + align:start position:0% +doing these problems if you write the + + + align:start position:0% +doing these problems if you write the +equation wrong you're going to be in a + + align:start position:0% +equation wrong you're going to be in a + + + align:start position:0% +equation wrong you're going to be in a +lot of trouble weak base should yield a + + align:start position:0% +lot of trouble weak base should yield a + + + align:start position:0% +lot of trouble weak base should yield a +basic solution so you should be getting + + align:start position:0% +basic solution so you should be getting + + + align:start position:0% +basic solution so you should be getting +hydroxide ions + + align:start position:0% +hydroxide ions + + + align:start position:0% +hydroxide ions +out all right so if we look at this + + align:start position:0% +out all right so if we look at this + + + align:start position:0% +out all right so if we look at this +problem we have an initial + + align:start position:0% +problem we have an initial + + + align:start position:0% +problem we have an initial +concentration of + + align:start position:0% +concentration of + + + align:start position:0% +concentration of +.15 + + align:start position:0% +.15 + + + align:start position:0% +.15 +molar and we don't have any of this and + + align:start position:0% +molar and we don't have any of this and + + + align:start position:0% +molar and we don't have any of this and +we don't have any of + + align:start position:0% +we don't have any of + + + align:start position:0% +we don't have any of +that the change is going to be - + + align:start position:0% +that the change is going to be - + + + align:start position:0% +that the change is going to be - +X Plus + + align:start position:0% +X Plus + + + align:start position:0% +X Plus +X and plus X + + align:start position:0% +X and plus X + + + align:start position:0% +X and plus X +then at + + align:start position:0% +then at + + + align:start position:0% +then at +equilibrium we'll have 05 - x and we'll + + align:start position:0% +equilibrium we'll have 05 - x and we'll + + + align:start position:0% +equilibrium we'll have 05 - x and we'll +have x and + + align:start position:0% + + + + align:start position:0% + +x so now it's a weak base in water so + + align:start position:0% +x so now it's a weak base in water so + + + align:start position:0% +x so now it's a weak base in water so +we're going to talk about a + + align:start position:0% + + + + align:start position:0% + +KB and so KB is the base ionization + + align:start position:0% +KB and so KB is the base ionization + + + align:start position:0% +KB and so KB is the base ionization +constant so KB is also going to be equal + + align:start position:0% +constant so KB is also going to be equal + + + align:start position:0% +constant so KB is also going to be equal +to the products because it is an + + align:start position:0% +to the products because it is an + + + align:start position:0% +to the products because it is an +equilibrium constant + + align:start position:0% +equilibrium constant + + + align:start position:0% +equilibrium constant +products over + + align:start position:0% +products over + + + align:start position:0% +products over +reactants and we're not including water + + align:start position:0% +reactants and we're not including water + + + align:start position:0% +reactants and we're not including water +because it's the + + align:start position:0% +because it's the + + + align:start position:0% +because it's the +solvent so this will be equal + + align:start position:0% +solvent so this will be equal + + + align:start position:0% +solvent so this will be equal +to X2 over + + align:start position:0% + + + + align:start position:0% + +1.15 minus + + align:start position:0% +1.15 minus + + + align:start position:0% +1.15 minus +X and we can try try this assumption + + align:start position:0% +X and we can try try this assumption + + + align:start position:0% +X and we can try try this assumption +again that that might be equal to x^2 + + align:start position:0% +again that that might be equal to x^2 + + + align:start position:0% +again that that might be equal to x^2 +over + + align:start position:0% + + + + align:start position:0% + +.15 so the + + align:start position:0% +.15 so the + + + align:start position:0% +.15 so the +KB is given and for a lot of the + + align:start position:0% +KB is given and for a lot of the + + + align:start position:0% +KB is given and for a lot of the +problems you'll be able to look this up + + align:start position:0% +problems you'll be able to look this up + + + align:start position:0% +problems you'll be able to look this up +in your book of 1.8 * 10us 5 so again + + align:start position:0% +in your book of 1.8 * 10us 5 so again + + + align:start position:0% +in your book of 1.8 * 10us 5 so again +it's a weak base it's less than one it + + align:start position:0% +it's a weak base it's less than one it + + + align:start position:0% +it's a weak base it's less than one it +has a a KB less uh a KB that's less than + + align:start position:0% +has a a KB less uh a KB that's less than + + + align:start position:0% +has a a KB less uh a KB that's less than +one one and so if we solve for x here we + + align:start position:0% +one one and so if we solve for x here we + + + align:start position:0% +one one and so if we solve for x here we +get X as + + align:start position:0% + + + + align:start position:0% + +0.0 + + align:start position:0% + + + + align:start position:0% + +0.164 and now we can check our + + align:start position:0% +0.164 and now we can check our + + + align:start position:0% +0.164 and now we can check our +assumption that that is okay using the + + align:start position:0% +assumption that that is okay using the + + + align:start position:0% +assumption that that is okay using the +5% rule + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +164 over + + align:start position:0% +164 over + + + align:start position:0% +164 over +.15 * 100 gives you + + align:start position:0% +.15 * 100 gives you + + + align:start position:0% +.15 * 100 gives you +1.1% so you are checking the Assumption + + align:start position:0% +1.1% so you are checking the Assumption + + + align:start position:0% +1.1% so you are checking the Assumption +and the assumption is okay it's less + + align:start position:0% +and the assumption is okay it's less + + + align:start position:0% +and the assumption is okay it's less +than five so we can use use that + + align:start position:0% + + + + align:start position:0% + +number all right so now we want to find + + align:start position:0% +number all right so now we want to find + + + align:start position:0% +number all right so now we want to find +out the pH of of this mixture at + + align:start position:0% +out the pH of of this mixture at + + + align:start position:0% +out the pH of of this mixture at +equilibrium and we have x x is equal to + + align:start position:0% +equilibrium and we have x x is equal to + + + align:start position:0% +equilibrium and we have x x is equal to +the hydroxide ion concentration + + align:start position:0% +the hydroxide ion concentration + + + align:start position:0% +the hydroxide ion concentration +so we can calculate first + + align:start position:0% +so we can calculate first + + + align:start position:0% +so we can calculate first +P minus log of the hydroxide ion + + align:start position:0% +P minus log of the hydroxide ion + + + align:start position:0% +P minus log of the hydroxide ion +concentration and so we have minus log + + align:start position:0% +concentration and so we have minus log + + + align:start position:0% +concentration and so we have minus log +of + + align:start position:0% + + + + align:start position:0% + +0.164 and we get + + align:start position:0% +0.164 and we get + + + align:start position:0% +0.164 and we get +2.79 so this only had two real + + align:start position:0% +2.79 so this only had two real + + + align:start position:0% +2.79 so this only had two real +significant figures we're carrying an + + align:start position:0% +significant figures we're carrying an + + + align:start position:0% +significant figures we're carrying an +extra one we only had 0.15 we only had + + align:start position:0% +extra one we only had 0.15 we only had + + + align:start position:0% +extra one we only had 0.15 we only had +had two significant figures here so this + + align:start position:0% +had two significant figures here so this + + + align:start position:0% +had two significant figures here so this +is going to get two after the decimal + + align:start position:0% +is going to get two after the decimal + + + align:start position:0% +is going to get two after the decimal +point so our number would since we have + + align:start position:0% +point so our number would since we have + + + align:start position:0% +point so our number would since we have +two + + align:start position:0% +two + + + align:start position:0% +two +here we get two sigfigs after + + align:start position:0% + + + + align:start position:0% + +decimal so now we have P how do we get + + align:start position:0% + + + + align:start position:0% + +pH yeah we we can subtract from 14 so + + align:start position:0% +pH yeah we we can subtract from 14 so + + + align:start position:0% +pH yeah we we can subtract from 14 so +the pH is going to equal + + align:start position:0% +the pH is going to equal + + + align:start position:0% +the pH is going to equal +14.00 minus + + align:start position:0% +14.00 minus + + + align:start position:0% +14.00 minus +2.79 and it'll be + + align:start position:0% +2.79 and it'll be + + + align:start position:0% +2.79 and it'll be +11.21 will be the + + align:start position:0% +11.21 will be the + + + align:start position:0% +11.21 will be the +ph and I just want to remind people + + align:start position:0% +ph and I just want to remind people + + + align:start position:0% +ph and I just want to remind people +sometimes when you're in a hurry on a + + align:start position:0% +sometimes when you're in a hurry on a + + + align:start position:0% +sometimes when you're in a hurry on a +test and you get to this point and have + + align:start position:0% +test and you get to this point and have + + + align:start position:0% +test and you get to this point and have +this number of 2.79 and you say oh I'm + + align:start position:0% +this number of 2.79 and you say oh I'm + + + align:start position:0% +this number of 2.79 and you say oh I'm +done but that's the p and if you think + + align:start position:0% +done but that's the p and if you think + + + align:start position:0% +done but that's the p and if you think +about it for a minute a weak base in + + align:start position:0% +about it for a minute a weak base in + + + align:start position:0% +about it for a minute a weak base in +water a base in water should give rise + + align:start position:0% +water a base in water should give rise + + + align:start position:0% +water a base in water should give rise +to a basic pH I.E a pH greater than + + align:start position:0% +to a basic pH I.E a pH greater than + + + align:start position:0% +to a basic pH I.E a pH greater than +seven so below seven is acidic above + + align:start position:0% +seven so below seven is acidic above + + + align:start position:0% +seven so below seven is acidic above +seven is basic so you have to remember + + align:start position:0% +seven is basic so you have to remember + + + align:start position:0% +seven is basic so you have to remember +to convert to pH the pH should be a + + align:start position:0% +to convert to pH the pH should be a + + + align:start position:0% +to convert to pH the pH should be a +basic number so just keep it in mind as + + align:start position:0% +basic number so just keep it in mind as + + + align:start position:0% +basic number so just keep it in mind as +you're doing these problems think about + + align:start position:0% +you're doing these problems think about + + + align:start position:0% +you're doing these problems think about +what the problem was oh it's a weak base + + align:start position:0% +what the problem was oh it's a weak base + + + align:start position:0% +what the problem was oh it's a weak base +in water does my answer make sense to + + align:start position:0% +in water does my answer make sense to + + + align:start position:0% +in water does my answer make sense to +kind of double check that you've gone + + align:start position:0% +kind of double check that you've gone + + + align:start position:0% +kind of double check that you've gone +you've gone the full Direction + + align:start position:0% + + + + align:start position:0% + +okay so that's weak base now we're going + + align:start position:0% +okay so that's weak base now we're going + + + align:start position:0% +okay so that's weak base now we're going +to talk about uh salts in in solution + + align:start position:0% +to talk about uh salts in in solution + + + align:start position:0% +to talk about uh salts in in solution +for a minute and salts and solution are + + align:start position:0% +for a minute and salts and solution are + + + align:start position:0% +for a minute and salts and solution are +going to break down into weak acid and + + align:start position:0% +going to break down into weak acid and + + + align:start position:0% +going to break down into weak acid and +weak base + + align:start position:0% +weak base + + + align:start position:0% +weak base +problems so if you have a a salt a salt + + align:start position:0% +problems so if you have a a salt a salt + + + align:start position:0% +problems so if you have a a salt a salt +can be formed by mixing an acid and a + + align:start position:0% +can be formed by mixing an acid and a + + + align:start position:0% +can be formed by mixing an acid and a +base as shown up here but the pH of salt + + align:start position:0% +base as shown up here but the pH of salt + + + align:start position:0% +base as shown up here but the pH of salt +water is not always going to be + + align:start position:0% +water is not always going to be + + + align:start position:0% +water is not always going to be +neutral so if if the salt + + align:start position:0% +neutral so if if the salt + + + align:start position:0% +neutral so if if the salt +contains for example the conjugate acid + + align:start position:0% +contains for example the conjugate acid + + + align:start position:0% +contains for example the conjugate acid +of a weak base then it contains a + + align:start position:0% +of a weak base then it contains a + + + align:start position:0% +of a weak base then it contains a +conjugate acid so it'll produce an + + align:start position:0% +conjugate acid so it'll produce an + + + align:start position:0% +conjugate acid so it'll produce an +acidic solution also salts that contain + + align:start position:0% +acidic solution also salts that contain + + + align:start position:0% +acidic solution also salts that contain +uh High some small highly charged metals + + align:start position:0% +uh High some small highly charged metals + + + align:start position:0% +uh High some small highly charged metals +like iron uh 3+ will also affect the + + align:start position:0% +like iron uh 3+ will also affect the + + + align:start position:0% +like iron uh 3+ will also affect the +pH this is something that that you + + align:start position:0% +pH this is something that that you + + + align:start position:0% +pH this is something that that you +should remember group one and group two + + align:start position:0% +should remember group one and group two + + + align:start position:0% +should remember group one and group two +metals um or metal cations with charges + + align:start position:0% +metals um or metal cations with charges + + + align:start position:0% +metals um or metal cations with charges +of plus one and we have Li I calcium + + align:start position:0% +of plus one and we have Li I calcium + + + align:start position:0% +of plus one and we have Li I calcium +plus 2 a silver what plus one these are + + align:start position:0% +plus 2 a silver what plus one these are + + + align:start position:0% +plus 2 a silver what plus one these are +all going to be neutral but other things + + align:start position:0% +all going to be neutral but other things + + + align:start position:0% +all going to be neutral but other things +like iron 3+ will not be or if you have + + align:start position:0% +like iron 3+ will not be or if you have + + + align:start position:0% +like iron 3+ will not be or if you have +a salt that contains a conjugate base of + + align:start position:0% +a salt that contains a conjugate base of + + + align:start position:0% +a salt that contains a conjugate base of +a weak acid it's a conjugate base so it + + align:start position:0% +a weak acid it's a conjugate base so it + + + align:start position:0% +a weak acid it's a conjugate base so it +can produce a basic + + align:start position:0% +can produce a basic + + + align:start position:0% +can produce a basic +solution so uh if you remember on Monday + + align:start position:0% +solution so uh if you remember on Monday + + + align:start position:0% +solution so uh if you remember on Monday +we measured the pH of MIT tap water and + + align:start position:0% +we measured the pH of MIT tap water and + + + align:start position:0% +we measured the pH of MIT tap water and +found that it was not neutral it was ph6 + + align:start position:0% +found that it was not neutral it was ph6 + + + align:start position:0% +found that it was not neutral it was ph6 +rather than seven so that would suggest + + align:start position:0% +rather than seven so that would suggest + + + align:start position:0% +rather than seven so that would suggest +that there was some salt in that tap + + align:start position:0% +that there was some salt in that tap + + + align:start position:0% +that there was some salt in that tap +water that was giving rise to a + + align:start position:0% +water that was giving rise to a + + + align:start position:0% +water that was giving rise to a +non-neutral + + align:start position:0% + + + + align:start position:0% + +pH so in terms this is also a review + + align:start position:0% +pH so in terms this is also a review + + + align:start position:0% +pH so in terms this is also a review +from last + + align:start position:0% +from last + + + align:start position:0% +from last +time there's this relationship between + + align:start position:0% +time there's this relationship between + + + align:start position:0% +time there's this relationship between +the conjugate acids and bases this isn't + + align:start position:0% +the conjugate acids and bases this isn't + + + align:start position:0% +the conjugate acids and bases this isn't +in your handout but uh just to to remind + + align:start position:0% +in your handout but uh just to to remind + + + align:start position:0% +in your handout but uh just to to remind +you what we were talking about if you + + align:start position:0% +you what we were talking about if you + + + align:start position:0% +you what we were talking about if you +have a strong acid its conjugate is + + align:start position:0% +have a strong acid its conjugate is + + + align:start position:0% +have a strong acid its conjugate is +ineffective as a base if you have an + + align:start position:0% +ineffective as a base if you have an + + + align:start position:0% +ineffective as a base if you have an +acid that's moderately weak to weak then + + align:start position:0% +acid that's moderately weak to weak then + + + align:start position:0% +acid that's moderately weak to weak then +it will have a conjugate base that's + + align:start position:0% +it will have a conjugate base that's + + + align:start position:0% +it will have a conjugate base that's +also moderately weak to very weak and if + + align:start position:0% +also moderately weak to very weak and if + + + align:start position:0% +also moderately weak to very weak and if +you have a really strong base then its + + align:start position:0% +you have a really strong base then its + + + align:start position:0% +you have a really strong base then its +conjugate will be ineffective as an acid + + align:start position:0% +conjugate will be ineffective as an acid + + + align:start position:0% +conjugate will be ineffective as an acid +so there's this uh this + + align:start position:0% +so there's this uh this + + + align:start position:0% +so there's this uh this +relationship all right so let's take a + + align:start position:0% +relationship all right so let's take a + + + align:start position:0% +relationship all right so let's take a +look at some examples of + + align:start position:0% + + + + align:start position:0% + +salts so if we have uh + + align:start position:0% +salts so if we have uh + + + align:start position:0% +salts so if we have uh +nh4 CL + + align:start position:0% +nh4 CL + + + align:start position:0% +nh4 CL +if you're asked whether putting some + + align:start position:0% +if you're asked whether putting some + + + align:start position:0% +if you're asked whether putting some +amount of this in water will lead to an + + align:start position:0% +amount of this in water will lead to an + + + align:start position:0% +amount of this in water will lead to an +acidic solution or a basic solution or a + + align:start position:0% +acidic solution or a basic solution or a + + + align:start position:0% +acidic solution or a basic solution or a +neutral solution this is how you would + + align:start position:0% +neutral solution this is how you would + + + align:start position:0% +neutral solution this is how you would +approach the problem first you're going + + align:start position:0% +approach the problem first you're going + + + align:start position:0% +approach the problem first you're going +to break this compound through the + + align:start position:0% +to break this compound through the + + + align:start position:0% +to break this compound through the +middle and consider two + + align:start position:0% +middle and consider two + + + align:start position:0% +middle and consider two +sides you'll say this salt would be + + align:start position:0% +sides you'll say this salt would be + + + align:start position:0% +sides you'll say this salt would be +composed of nh4 + + align:start position:0% +composed of nh4 + + + align:start position:0% +composed of nh4 +plus and cl + + align:start position:0% + + + + align:start position:0% + +minus then you're going to ask whether + + align:start position:0% +minus then you're going to ask whether + + + align:start position:0% +minus then you're going to ask whether +this is a conjugate acid of a weak + + align:start position:0% +this is a conjugate acid of a weak + + + align:start position:0% +this is a conjugate acid of a weak +base so is this a conjugate acid + + align:start position:0% +base so is this a conjugate acid + + + align:start position:0% +base so is this a conjugate acid +of a weak base if it is a conjugate acid + + align:start position:0% +of a weak base if it is a conjugate acid + + + align:start position:0% +of a weak base if it is a conjugate acid +of a weak base then that will affect the + + align:start position:0% +of a weak base then that will affect the + + + align:start position:0% +of a weak base then that will affect the +pH of the + + align:start position:0% +pH of the + + + align:start position:0% +pH of the +solution so what's the conjugate of + + align:start position:0% +solution so what's the conjugate of + + + align:start position:0% +solution so what's the conjugate of +Na + + align:start position:0% +Na + + + align:start position:0% +Na +nh4 Plus + + align:start position:0% + + + + align:start position:0% + +so the conjugate of this is + + align:start position:0% +so the conjugate of this is + + + align:start position:0% +so the conjugate of this is +ammonia so the con the weak base if you + + align:start position:0% +ammonia so the con the weak base if you + + + align:start position:0% +ammonia so the con the weak base if you +take the weak base so the conjugate the + + align:start position:0% +take the weak base so the conjugate the + + + align:start position:0% +take the weak base so the conjugate the +weak + + align:start position:0% + + + + align:start position:0% + +base is + + align:start position:0% +base is + + + align:start position:0% +base is +NH3 and if you added a proton to this + + align:start position:0% +NH3 and if you added a proton to this + + + align:start position:0% +NH3 and if you added a proton to this +you get the conjugate acid NH H4 plus so + + align:start position:0% +you get the conjugate acid NH H4 plus so + + + align:start position:0% +you get the conjugate acid NH H4 plus so +this is a weak base so the answer to + + align:start position:0% +this is a weak base so the answer to + + + align:start position:0% +this is a weak base so the answer to +that question was yes you could look it + + align:start position:0% +that question was yes you could look it + + + align:start position:0% +that question was yes you could look it +up in the table here's ammonia it has a + + align:start position:0% +up in the table here's ammonia it has a + + + align:start position:0% +up in the table here's ammonia it has a +KB + + align:start position:0% +KB + + + align:start position:0% +KB +that's uh fairly small so it is a weak + + align:start position:0% +that's uh fairly small so it is a weak + + + align:start position:0% +that's uh fairly small so it is a weak +base and we also had it on this this + + align:start position:0% +base and we also had it on this this + + + align:start position:0% +base and we also had it on this this +chart you had NH uh + + align:start position:0% +chart you had NH uh + + + align:start position:0% +chart you had NH uh +3 over here and so you could see that it + + align:start position:0% +3 over here and so you could see that it + + + align:start position:0% +3 over here and so you could see that it +is in fact a weak a weak + + align:start position:0% +is in fact a weak a weak + + + align:start position:0% +is in fact a weak a weak +base and we can look up the uh the KB + + align:start position:0% +base and we can look up the uh the KB + + + align:start position:0% +base and we can look up the uh the KB +for + + align:start position:0% + + + + align:start position:0% + +that and so the + + align:start position:0% + + + + align:start position:0% + +KB is 1 Point 8 * + + align:start position:0% +KB is 1 Point 8 * + + + align:start position:0% +KB is 1 Point 8 * +10-5 so that's a weak base so because + + align:start position:0% +10-5 so that's a weak base so because + + + align:start position:0% +10-5 so that's a weak base so because +the conjugate is a weak base that means + + align:start position:0% +the conjugate is a weak base that means + + + align:start position:0% +the conjugate is a weak base that means +that the conjugate acid is also a weak + + align:start position:0% +that the conjugate acid is also a weak + + + align:start position:0% +that the conjugate acid is also a weak +acid and so this should be acidic in + + align:start position:0% + + + + align:start position:0% + +solution so that should be acidic in + + align:start position:0% +solution so that should be acidic in + + + align:start position:0% +solution so that should be acidic in +solution and let's just write that out + + align:start position:0% +solution and let's just write that out + + + align:start position:0% +solution and let's just write that out +over here so if we have + + align:start position:0% +over here so if we have + + + align:start position:0% +over here so if we have +nh4+ and that's got to be a weak acid + + align:start position:0% +nh4+ and that's got to be a weak acid + + + align:start position:0% +nh4+ and that's got to be a weak acid +because its conjugate is a weak base and + + align:start position:0% +because its conjugate is a weak base and + + + align:start position:0% +because its conjugate is a weak base and +we put the weak acid in + + align:start position:0% +we put the weak acid in + + + align:start position:0% +we put the weak acid in +water we should get the conjugate base + + align:start position:0% +water we should get the conjugate base + + + align:start position:0% +water we should get the conjugate base +back plus hydronium ion and the presence + + align:start position:0% +back plus hydronium ion and the presence + + + align:start position:0% +back plus hydronium ion and the presence +of the hydronium ion is going to make + + align:start position:0% +of the hydronium ion is going to make + + + align:start position:0% +of the hydronium ion is going to make +that + + align:start position:0% +that + + + align:start position:0% +that +acidic and so this is a weak weak base + + align:start position:0% +acidic and so this is a weak weak base + + + align:start position:0% +acidic and so this is a weak weak base +over here it's conjugate is a weak base + + align:start position:0% +over here it's conjugate is a weak base + + + align:start position:0% +over here it's conjugate is a weak base +and we can look up a Ka number for it + + align:start position:0% +and we can look up a Ka number for it + + + align:start position:0% +and we can look up a Ka number for it +5.6 * + + align:start position:0% +5.6 * + + + align:start position:0% +5.6 * +10-1 so that is in fact a weak + + align:start position:0% + + + + align:start position:0% + +acid and so here it is on this table we + + align:start position:0% +acid and so here it is on this table we + + + align:start position:0% +acid and so here it is on this table we +can look it up and it is a weak it's + + align:start position:0% +can look it up and it is a weak it's + + + align:start position:0% +can look it up and it is a weak it's +less than one it's definitely a weak + + align:start position:0% +less than one it's definitely a weak + + + align:start position:0% +less than one it's definitely a weak +acid so this part on this side of the uh + + align:start position:0% +acid so this part on this side of the uh + + + align:start position:0% +acid so this part on this side of the uh +compound we have something that's going + + align:start position:0% +compound we have something that's going + + + align:start position:0% +compound we have something that's going +to produce an acidic solution U so now + + align:start position:0% +to produce an acidic solution U so now + + + align:start position:0% +to produce an acidic solution U so now +we have to ask what about this side over + + align:start position:0% +we have to ask what about this side over + + + align:start position:0% +we have to ask what about this side over +here and so we would ask is this a + + align:start position:0% +here and so we would ask is this a + + + align:start position:0% +here and so we would ask is this a +conjugate + + align:start position:0% +conjugate + + + align:start position:0% +conjugate +base of a + + align:start position:0% +base of a + + + align:start position:0% +base of a +weak + + align:start position:0% + + + + align:start position:0% + +acid is CL minus a conjugate base of a + + align:start position:0% +acid is CL minus a conjugate base of a + + + align:start position:0% +acid is CL minus a conjugate base of a +weak acid what would be the acid the + + align:start position:0% +weak acid what would be the acid the + + + align:start position:0% +weak acid what would be the acid the +conjugate acid of Cl + + align:start position:0% +conjugate acid of Cl + + + align:start position:0% +conjugate acid of Cl +minus HCL + + align:start position:0% +minus HCL + + + align:start position:0% +minus HCL +so the conjugate is HCl is that + + align:start position:0% +so the conjugate is HCl is that + + + align:start position:0% +so the conjugate is HCl is that +weak no so this is a + + align:start position:0% +weak no so this is a + + + align:start position:0% +weak no so this is a +strong a strong acid and that's one that + + align:start position:0% +strong a strong acid and that's one that + + + align:start position:0% +strong a strong acid and that's one that +you'll encounter a bunch so you'll + + align:start position:0% +you'll encounter a bunch so you'll + + + align:start position:0% +you'll encounter a bunch so you'll +definitely have uh that that memorized + + align:start position:0% +definitely have uh that that memorized + + + align:start position:0% +definitely have uh that that memorized +by the time you get through the problems + + align:start position:0% +by the time you get through the problems + + + align:start position:0% +by the time you get through the problems +so it has a Ka over here of 10 to the + + align:start position:0% +so it has a Ka over here of 10 to the + + + align:start position:0% +so it has a Ka over here of 10 to the +7th so if you put that in in water if + + align:start position:0% +7th so if you put that in in water if + + + align:start position:0% +7th so if you put that in in water if +you had + + align:start position:0% +you had + + + align:start position:0% +you had +HCL in water it's a really strong + + align:start position:0% +HCL in water it's a really strong + + + align:start position:0% +HCL in water it's a really strong +acid Ka 10 the 7th and + + align:start position:0% +acid Ka 10 the 7th and + + + align:start position:0% +acid Ka 10 the 7th and +so it would go pretty much all the way + + align:start position:0% +so it would go pretty much all the way + + + align:start position:0% +so it would go pretty much all the way +to completion so that means that this + + align:start position:0% +to completion so that means that this + + + align:start position:0% +to completion so that means that this +would be + + align:start position:0% +would be + + + align:start position:0% +would be +ineffective as a + + align:start position:0% +ineffective as a + + + align:start position:0% +ineffective as a +base if you have a strong + + align:start position:0% + + + + align:start position:0% + +acid again there's these relationships + + align:start position:0% +acid again there's these relationships + + + align:start position:0% +acid again there's these relationships +that we talked about um if something is + + align:start position:0% +that we talked about um if something is + + + align:start position:0% +that we talked about um if something is +a really strong acid up here then its + + align:start position:0% +a really strong acid up here then its + + + align:start position:0% +a really strong acid up here then its +conjugate is completely ineffective as a + + align:start position:0% +conjugate is completely ineffective as a + + + align:start position:0% +conjugate is completely ineffective as a +base so this then is going to be + + align:start position:0% + + + + align:start position:0% + +neutral so because this is not going to + + align:start position:0% +neutral so because this is not going to + + + align:start position:0% +neutral so because this is not going to +change the pH anymore it's ineffective + + align:start position:0% +change the pH anymore it's ineffective + + + align:start position:0% +change the pH anymore it's ineffective +it is base it's not going to make the + + align:start position:0% +it is base it's not going to make the + + + align:start position:0% +it is base it's not going to make the +solution basic at all whereas on the + + align:start position:0% +solution basic at all whereas on the + + + align:start position:0% +solution basic at all whereas on the +other side nh4 plus is a conjugate acid + + align:start position:0% +other side nh4 plus is a conjugate acid + + + align:start position:0% +other side nh4 plus is a conjugate acid +of a weak base so it will produce an + + align:start position:0% +of a weak base so it will produce an + + + align:start position:0% +of a weak base so it will produce an +acidic solution so the answer is that + + align:start position:0% +acidic solution so the answer is that + + + align:start position:0% +acidic solution so the answer is that +this salt in water will be + + align:start position:0% + + + + align:start position:0% + +acidic so if you were given an amount of + + align:start position:0% +acidic so if you were given an amount of + + + align:start position:0% +acidic so if you were given an amount of +this compound if you + + align:start position:0% +this compound if you + + + align:start position:0% +this compound if you +said5 molar for example what is the pH + + align:start position:0% +said5 molar for example what is the pH + + + align:start position:0% +said5 molar for example what is the pH +you could work that out by just doing a + + align:start position:0% +you could work that out by just doing a + + + align:start position:0% +you could work that out by just doing a +weak acid type problem and solving for x + + align:start position:0% +weak acid type problem and solving for x + + + align:start position:0% +weak acid type problem and solving for x +here and calculating pH so this + + align:start position:0% +here and calculating pH so this + + + align:start position:0% +here and calculating pH so this +particular salt in water problem is just + + align:start position:0% +particular salt in water problem is just + + + align:start position:0% +particular salt in water problem is just +a weak acid in water + + align:start position:0% + + + + align:start position:0% + +problem okay let's look at another + + align:start position:0% + + + + align:start position:0% + +example okay again we're going to take + + align:start position:0% +example okay again we're going to take + + + align:start position:0% +example okay again we're going to take +take this compound and break it + + align:start position:0% +take this compound and break it + + + align:start position:0% +take this compound and break it +up and we form + + align:start position:0% +up and we form + + + align:start position:0% +up and we form +na+ and ch3 + + align:start position:0% +na+ and ch3 + + + align:start position:0% +na+ and ch3 +Co + + align:start position:0% + + + + align:start position:0% + +minus so then we ask is + + align:start position:0% +minus so then we ask is + + + align:start position:0% +minus so then we ask is +this a conjugate + + align:start position:0% +this a conjugate + + + align:start position:0% +this a conjugate +acid of a + + align:start position:0% +acid of a + + + align:start position:0% +acid of a +weak + + align:start position:0% +weak + + + align:start position:0% +weak +base and what's the + + align:start position:0% +base and what's the + + + align:start position:0% +base and what's the +answer where do you think it probably + + align:start position:0% +answer where do you think it probably + + + align:start position:0% +answer where do you think it probably +came + + align:start position:0% +came + + + align:start position:0% +came +from yeah it probably came from NaOH so + + align:start position:0% +from yeah it probably came from NaOH so + + + align:start position:0% +from yeah it probably came from NaOH so +this one the answer here is + + align:start position:0% +this one the answer here is + + + align:start position:0% +this one the answer here is +no and we talked about rules that all + + align:start position:0% +no and we talked about rules that all + + + align:start position:0% +no and we talked about rules that all +group one and group two um are + + align:start position:0% +group one and group two um are + + + align:start position:0% +group one and group two um are +neutral group one ions are neutral group + + align:start position:0% +neutral group one ions are neutral group + + + align:start position:0% +neutral group one ions are neutral group +one and group two are + + align:start position:0% +one and group two are + + + align:start position:0% +one and group two are +neutral so this in + + align:start position:0% +neutral so this in + + + align:start position:0% +neutral so this in +solution will be neutral + + align:start position:0% + + + + align:start position:0% + +all right so let's look at the other + + align:start position:0% +all right so let's look at the other + + + align:start position:0% +all right so let's look at the other +side and ask so is this the conjugate + + align:start position:0% +side and ask so is this the conjugate + + + align:start position:0% +side and ask so is this the conjugate +base of a + + align:start position:0% +base of a + + + align:start position:0% +base of a +weak + + align:start position:0% +weak + + + align:start position:0% +weak +acid and what would be the acid + + align:start position:0% +acid and what would be the acid + + + align:start position:0% +acid and what would be the acid +here yeah atic acid so we have ch3 + + align:start position:0% +here yeah atic acid so we have ch3 + + + align:start position:0% +here yeah atic acid so we have ch3 +Co and we can look to see if that is a + + align:start position:0% +Co and we can look to see if that is a + + + align:start position:0% +Co and we can look to see if that is a +weak + + align:start position:0% +weak + + + align:start position:0% +weak +acid and we can look it up here here and + + align:start position:0% +acid and we can look it up here here and + + + align:start position:0% +acid and we can look it up here here and +so we have um you get the right get the + + align:start position:0% +so we have um you get the right get the + + + align:start position:0% +so we have um you get the right get the +right line 1.76 * 10us 5 so is that a + + align:start position:0% +right line 1.76 * 10us 5 so is that a + + + align:start position:0% +right line 1.76 * 10us 5 so is that a +weak + + align:start position:0% + + + + align:start position:0% + +acid is that a weak acid + + align:start position:0% +acid is that a weak acid + + + align:start position:0% +acid is that a weak acid +yes so if it's a conjugate base of a + + align:start position:0% +yes so if it's a conjugate base of a + + + align:start position:0% +yes so if it's a conjugate base of a +weak acid then in + + align:start position:0% +weak acid then in + + + align:start position:0% +weak acid then in +solution it's going to be basic + + align:start position:0% + + + + align:start position:0% + +and we can work that out if we wrote it + + align:start position:0% +and we can work that out if we wrote it + + + align:start position:0% +and we can work that out if we wrote it +out we have ch3 Co minus in + + align:start position:0% +out we have ch3 Co minus in + + + align:start position:0% +out we have ch3 Co minus in +water is going to yield hydroxide + + align:start position:0% +water is going to yield hydroxide + + + align:start position:0% +water is going to yield hydroxide +ions and the conjugate acid over here + + align:start position:0% +ions and the conjugate acid over here + + + align:start position:0% +ions and the conjugate acid over here +and the presence of this will make of + + align:start position:0% +and the presence of this will make of + + + align:start position:0% +and the presence of this will make of +the hydroxide ion will make the solution + + align:start position:0% +the hydroxide ion will make the solution + + + align:start position:0% +the hydroxide ion will make the solution +basic so this is a weak a weak base on + + align:start position:0% +basic so this is a weak a weak base on + + + align:start position:0% +basic so this is a weak a weak base on +this side and so if if you were asked + + align:start position:0% +this side and so if if you were asked + + + align:start position:0% +this side and so if if you were asked +given an amount you could solve the + + align:start position:0% +given an amount you could solve the + + + align:start position:0% +given an amount you could solve the +problem using the KB of the weak base + + align:start position:0% +problem using the KB of the weak base + + + align:start position:0% +problem using the KB of the weak base +solving for o minus finding Po and then + + align:start position:0% +solving for o minus finding Po and then + + + align:start position:0% +solving for o minus finding Po and then +pH so overall this salt in solution will + + align:start position:0% +pH so overall this salt in solution will + + + align:start position:0% +pH so overall this salt in solution will +give rise + + align:start position:0% +give rise + + + align:start position:0% +give rise +to a basic solution so you'd have a + + align:start position:0% +to a basic solution so you'd have a + + + align:start position:0% +to a basic solution so you'd have a +should have a pH greater than seven so + + align:start position:0% +should have a pH greater than seven so + + + align:start position:0% +should have a pH greater than seven so +this salt and water would give rise to a + + align:start position:0% +this salt and water would give rise to a + + + align:start position:0% +this salt and water would give rise to a +basic solution and this salt and water + + align:start position:0% +basic solution and this salt and water + + + align:start position:0% +basic solution and this salt and water +problem breaks down into a weak base in + + align:start position:0% +problem breaks down into a weak base in + + + align:start position:0% +problem breaks down into a weak base in +water + + align:start position:0% + + + + align:start position:0% + +problem so let's just do the uh + + align:start position:0% + + + + align:start position:0% + +generic the generic type of problem so + + align:start position:0% +generic the generic type of problem so + + + align:start position:0% +generic the generic type of problem so +in the + + align:start position:0% +in the + + + align:start position:0% +in the +general the general + + align:start position:0% +general the general + + + align:start position:0% +general the general +case if we have made up compound + + align:start position:0% +case if we have made up compound + + + align:start position:0% +case if we have made up compound +XZ madeup compound XZ will break down + + align:start position:0% +XZ madeup compound XZ will break down + + + align:start position:0% +XZ madeup compound XZ will break down +into + + align:start position:0% +into + + + align:start position:0% +into +X+ and Z + + align:start position:0% +X+ and Z + + + align:start position:0% +X+ and Z +minus and you're going to + + align:start position:0% +minus and you're going to + + + align:start position:0% +minus and you're going to +ask is this a + + align:start position:0% +ask is this a + + + align:start position:0% +ask is this a +conjugate + + align:start position:0% +conjugate + + + align:start position:0% +conjugate +acid of weak + + align:start position:0% + + + + align:start position:0% + +base and + + align:start position:0% +base and + + + align:start position:0% +base and +um or you're asking basically is this + + align:start position:0% +um or you're asking basically is this + + + align:start position:0% +um or you're asking basically is this +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +acidic so if the answer is yes if you + + align:start position:0% +acidic so if the answer is yes if you + + + align:start position:0% +acidic so if the answer is yes if you +have a conjugate of a weak base which is + + align:start position:0% +have a conjugate of a weak base which is + + + align:start position:0% +have a conjugate of a weak base which is +a weak acid you will have an acidic + + align:start position:0% +a weak acid you will have an acidic + + + align:start position:0% +a weak acid you will have an acidic +solution if the answer is no you will + + align:start position:0% +solution if the answer is no you will + + + align:start position:0% +solution if the answer is no you will +have a neutral at least in terms of the + + align:start position:0% +have a neutral at least in terms of the + + + align:start position:0% +have a neutral at least in terms of the +X on the other side for the Z minus + + align:start position:0% +X on the other side for the Z minus + + + align:start position:0% +X on the other side for the Z minus +you're asking the + + align:start position:0% +you're asking the + + + align:start position:0% +you're asking the +question is this a + + align:start position:0% +question is this a + + + align:start position:0% +question is this a +conjugate + + align:start position:0% +conjugate + + + align:start position:0% +conjugate +base of a weak acid + + align:start position:0% + + + + align:start position:0% + +if it is a conjugate base of a weak acid + + align:start position:0% +if it is a conjugate base of a weak acid + + + align:start position:0% +if it is a conjugate base of a weak acid +then it's going to be basic it will be a + + align:start position:0% +then it's going to be basic it will be a + + + align:start position:0% +then it's going to be basic it will be a +weak base and so the answer is yes + + align:start position:0% +weak base and so the answer is yes + + + align:start position:0% +weak base and so the answer is yes +you're going to get a basic solution if + + align:start position:0% +you're going to get a basic solution if + + + align:start position:0% +you're going to get a basic solution if +the answer is no here it will be + + align:start position:0% +the answer is no here it will be + + + align:start position:0% +the answer is no here it will be +neutral and in these problems in the + + align:start position:0% +neutral and in these problems in the + + + align:start position:0% +neutral and in these problems in the +short answer type format here you're not + + align:start position:0% +short answer type format here you're not + + + align:start position:0% +short answer type format here you're not +going to be given a case where one side + + align:start position:0% +going to be given a case where one side + + + align:start position:0% +going to be given a case where one side +will be acidic and the other side will + + align:start position:0% +will be acidic and the other side will + + + align:start position:0% +will be acidic and the other side will +be basic because then you can't give a + + align:start position:0% +be basic because then you can't give a + + + align:start position:0% +be basic because then you can't give a +short answer to that problem you'd have + + align:start position:0% +short answer to that problem you'd have + + + align:start position:0% +short answer to that problem you'd have +to figure out which one is more acidic + + align:start position:0% +to figure out which one is more acidic + + + align:start position:0% +to figure out which one is more acidic +and which one was more basic uh so in + + align:start position:0% +and which one was more basic uh so in + + + align:start position:0% +and which one was more basic uh so in +these types of problems one side will + + align:start position:0% +these types of problems one side will + + + align:start position:0% +these types of problems one side will +always be neutral or they could both be + + align:start position:0% +always be neutral or they could both be + + + align:start position:0% +always be neutral or they could both be +neutral you will see examples where both + + align:start position:0% +neutral you will see examples where both + + + align:start position:0% +neutral you will see examples where both +of them are neutral but you're looking + + align:start position:0% +of them are neutral but you're looking + + + align:start position:0% +of them are neutral but you're looking +at each side and asking a question about + + align:start position:0% +at each side and asking a question about + + + align:start position:0% +at each side and asking a question about +it so that's how you go about doing + + align:start position:0% +it so that's how you go about doing + + + align:start position:0% +it so that's how you go about doing +these salt and and water problems + + align:start position:0% + + + + align:start position:0% + +all right so this leads us right into + + align:start position:0% +all right so this leads us right into + + + align:start position:0% +all right so this leads us right into +buffers + + align:start position:0% + + + + align:start position:0% + +so buffers this is another type of + + align:start position:0% +so buffers this is another type of + + + align:start position:0% +so buffers this is another type of +problem that that we will have and again + + align:start position:0% +problem that that we will have and again + + + align:start position:0% +problem that that we will have and again +you're talking about weak acids and weak + + align:start position:0% +you're talking about weak acids and weak + + + align:start position:0% +you're talking about weak acids and weak +bases here so a buffer is any solution + + align:start position:0% +bases here so a buffer is any solution + + + align:start position:0% +bases here so a buffer is any solution +that maintains pretty much a constant pH + + align:start position:0% +that maintains pretty much a constant pH + + + align:start position:0% +that maintains pretty much a constant pH +despite the addition of small amount of + + align:start position:0% +despite the addition of small amount of + + + align:start position:0% +despite the addition of small amount of +acids and bases so buffering is all + + align:start position:0% +acids and bases so buffering is all + + + align:start position:0% +acids and bases so buffering is all +about about constant + + align:start position:0% +about about constant + + + align:start position:0% +about about constant +pH an acidic buffer is just a buffer + + align:start position:0% +pH an acidic buffer is just a buffer + + + align:start position:0% +pH an acidic buffer is just a buffer +that's going to pH or stay sort of a + + align:start position:0% +that's going to pH or stay sort of a + + + align:start position:0% +that's going to pH or stay sort of a +constant pH in the acidic range so the + + align:start position:0% +constant pH in the acidic range so the + + + align:start position:0% +constant pH in the acidic range so the +acidic side of neutral and it would + + align:start position:0% +acidic side of neutral and it would + + + align:start position:0% +acidic side of neutral and it would +consist of a weak acid and its conjugate + + align:start position:0% +consist of a weak acid and its conjugate + + + align:start position:0% +consist of a weak acid and its conjugate +base supplied as a salt a basic buffer + + align:start position:0% +base supplied as a salt a basic buffer + + + align:start position:0% +base supplied as a salt a basic buffer +will have a weak base and its conjugate + + align:start position:0% +will have a weak base and its conjugate + + + align:start position:0% +will have a weak base and its conjugate +acid supplied as a salt and it's going + + align:start position:0% +acid supplied as a salt and it's going + + + align:start position:0% +acid supplied as a salt and it's going +to buffer on the basic side of neutral + + align:start position:0% +to buffer on the basic side of neutral + + + align:start position:0% +to buffer on the basic side of neutral +so that that Mak makes a lot of + + align:start position:0% +so that that Mak makes a lot of + + + align:start position:0% +so that that Mak makes a lot of +sense all right so let's look at a + + align:start position:0% +sense all right so let's look at a + + + align:start position:0% +sense all right so let's look at a +buffer example so in all buffers you're + + align:start position:0% +buffer example so in all buffers you're + + + align:start position:0% +buffer example so in all buffers you're +going to have an acid mixed with its + + align:start position:0% +going to have an acid mixed with its + + + align:start position:0% +going to have an acid mixed with its +conjugate as in the form of a salt to + + align:start position:0% +conjugate as in the form of a salt to + + + align:start position:0% +conjugate as in the form of a salt to +get a dynamic + + align:start position:0% +get a dynamic + + + align:start position:0% +get a dynamic +equilibrium and so if we have this we + + align:start position:0% +equilibrium and so if we have this we + + + align:start position:0% +equilibrium and so if we have this we +have the acid and it's conjugate added + + align:start position:0% +have the acid and it's conjugate added + + + align:start position:0% +have the acid and it's conjugate added +here and we ask what happens if you add + + align:start position:0% +here and we ask what happens if you add + + + align:start position:0% +here and we ask what happens if you add +a strong acid to this + + align:start position:0% +a strong acid to this + + + align:start position:0% +a strong acid to this +solution and because again what we want + + align:start position:0% +solution and because again what we want + + + align:start position:0% +solution and because again what we want +to have a buffer do is maintain a + + align:start position:0% +to have a buffer do is maintain a + + + align:start position:0% +to have a buffer do is maintain a +constant + + align:start position:0% +constant + + + align:start position:0% +constant +pH so you need to have about the same + + align:start position:0% +pH so you need to have about the same + + + align:start position:0% +pH so you need to have about the same +amount of this guy as this guy for that + + align:start position:0% +amount of this guy as this guy for that + + + align:start position:0% +amount of this guy as this guy for that +to be + + align:start position:0% +to be + + + align:start position:0% +to be +true so if you added strong acid and you + + align:start position:0% +true so if you added strong acid and you + + + align:start position:0% +true so if you added strong acid and you +had some of this and some of this the + + align:start position:0% +had some of this and some of this the + + + align:start position:0% +had some of this and some of this the +acid is going to react with the + + align:start position:0% +acid is going to react with the + + + align:start position:0% +acid is going to react with the +conjugate base and drive it in this + + align:start position:0% +conjugate base and drive it in this + + + align:start position:0% +conjugate base and drive it in this +direction using up the amount of strong + + align:start position:0% +direction using up the amount of strong + + + align:start position:0% +direction using up the amount of strong +acid that was added so the added uh acid + + align:start position:0% +acid that was added so the added uh acid + + + align:start position:0% +acid that was added so the added uh acid +hydronium ions are affective itively + + align:start position:0% +hydronium ions are affective itively + + + align:start position:0% +hydronium ions are affective itively +removed and the pH stays pretty much + + align:start position:0% + + + + align:start position:0% + +constant now what happens if you add a + + align:start position:0% +constant now what happens if you add a + + + align:start position:0% +constant now what happens if you add a +strong base well strong base is going to + + align:start position:0% +strong base well strong base is going to + + + align:start position:0% +strong base well strong base is going to +react with the weak acid over here and + + align:start position:0% +react with the weak acid over here and + + + align:start position:0% +react with the weak acid over here and +it will also be + + align:start position:0% +it will also be + + + align:start position:0% +it will also be +consumed and so you you are taking uh + + align:start position:0% +consumed and so you you are taking uh + + + align:start position:0% +consumed and so you you are taking uh +the uh the O here is removing a proton + + align:start position:0% +the uh the O here is removing a proton + + + align:start position:0% +the uh the O here is removing a proton +it's reacting with the weak acid and + + align:start position:0% +it's reacting with the weak acid and + + + align:start position:0% +it's reacting with the weak acid and +it'll form more conjugate base and it'll + + align:start position:0% +it'll form more conjugate base and it'll + + + align:start position:0% +it'll form more conjugate base and it'll +also form water so again it's + + align:start position:0% +also form water so again it's + + + align:start position:0% +also form water so again it's +effectively removed and the pH stays + + align:start position:0% +effectively removed and the pH stays + + + align:start position:0% +effectively removed and the pH stays +pretty much constant so a buffer should + + align:start position:0% +pretty much constant so a buffer should + + + align:start position:0% +pretty much constant so a buffer should +be a source uh a source in a sync for um + + align:start position:0% +be a source uh a source in a sync for um + + + align:start position:0% +be a source uh a source in a sync for um +added uh problems to the reaction it's + + align:start position:0% +added uh problems to the reaction it's + + + align:start position:0% +added uh problems to the reaction it's +going to use up either the acid or the + + align:start position:0% +going to use up either the acid or the + + + align:start position:0% +going to use up either the acid or the +base that's added and keep keep the uh + + align:start position:0% +base that's added and keep keep the uh + + + align:start position:0% +base that's added and keep keep the uh +pH pretty much constant so again what's + + align:start position:0% +pH pretty much constant so again what's + + + align:start position:0% +pH pretty much constant so again what's +happening is that the weak acid that you + + align:start position:0% +happening is that the weak acid that you + + + align:start position:0% +happening is that the weak acid that you +use and you can have anyone there is + + align:start position:0% +use and you can have anyone there is + + + align:start position:0% +use and you can have anyone there is +going to transfer protons to this and + + align:start position:0% +going to transfer protons to this and + + + align:start position:0% +going to transfer protons to this and +that will uh cause the reaction to + + align:start position:0% +that will uh cause the reaction to + + + align:start position:0% +that will uh cause the reaction to +happen use up the H hydroxide ion a + + align:start position:0% +happen use up the H hydroxide ion a + + + align:start position:0% +happen use up the H hydroxide ion a +conjugate base that's added to the as a + + align:start position:0% +conjugate base that's added to the as a + + + align:start position:0% +conjugate base that's added to the as a +form of a salt um it would would then be + + align:start position:0% +form of a salt um it would would then be + + + align:start position:0% +form of a salt um it would would then be +able to accept protons from any acid + + align:start position:0% +able to accept protons from any acid + + + align:start position:0% +able to accept protons from any acid +that's used so you need both the weak + + align:start position:0% +that's used so you need both the weak + + + align:start position:0% +that's used so you need both the weak +acid and the conjugate base added in the + + align:start position:0% +acid and the conjugate base added in the + + + align:start position:0% +acid and the conjugate base added in the +form of salt one will react if you add + + align:start position:0% +form of salt one will react if you add + + + align:start position:0% +form of salt one will react if you add +extra acid one will react if you add + + align:start position:0% +extra acid one will react if you add + + + align:start position:0% +extra acid one will react if you add +excess + + align:start position:0% +excess + + + align:start position:0% +excess +base so why wouldn't a strong strong + + align:start position:0% +base so why wouldn't a strong strong + + + align:start position:0% +base so why wouldn't a strong strong +acid and the conjugate base of that + + align:start position:0% +acid and the conjugate base of that + + + align:start position:0% +acid and the conjugate base of that +strong acid why wouldn't that make a + + align:start position:0% +strong acid why wouldn't that make a + + + align:start position:0% +strong acid why wouldn't that make a +good + + align:start position:0% + + + + align:start position:0% + +buffer + + align:start position:0% + + + + align:start position:0% + +yeah yeah right because the conjugate + + align:start position:0% +yeah yeah right because the conjugate + + + align:start position:0% +yeah yeah right because the conjugate +base would be ineffective as a base and + + align:start position:0% +base would be ineffective as a base and + + + align:start position:0% +base would be ineffective as a base and +so the strong acid would go to + + align:start position:0% +so the strong acid would go to + + + align:start position:0% +so the strong acid would go to +completion will drive to the right this + + align:start position:0% +completion will drive to the right this + + + align:start position:0% +completion will drive to the right this +is ineffective as a base you're not + + align:start position:0% +is ineffective as a base you're not + + + align:start position:0% +is ineffective as a base you're not +going to push it back the other way so + + align:start position:0% +going to push it back the other way so + + + align:start position:0% +going to push it back the other way so +you're only going to have a good + + align:start position:0% +you're only going to have a good + + + align:start position:0% +you're only going to have a good +buffering system with a weak something + + align:start position:0% +buffering system with a weak something + + + align:start position:0% +buffering system with a weak something +and it's conjugate that's also a weak + + align:start position:0% +and it's conjugate that's also a weak + + + align:start position:0% +and it's conjugate that's also a weak +something so a weak acid and it's + + align:start position:0% +something so a weak acid and it's + + + align:start position:0% +something so a weak acid and it's +conjugate weak base a weak base and it's + + align:start position:0% +conjugate weak base a weak base and it's + + + align:start position:0% +conjugate weak base a weak base and it's +conjugate weak acid that will buffer + + align:start position:0% +conjugate weak acid that will buffer + + + align:start position:0% +conjugate weak acid that will buffer +because it'll go both directions so both + + align:start position:0% +because it'll go both directions so both + + + align:start position:0% +because it'll go both directions so both +conjugates have to work as an acid or a + + align:start position:0% +conjugates have to work as an acid or a + + + align:start position:0% +conjugates have to work as an acid or a +base if you have a strong acid then its + + align:start position:0% +base if you have a strong acid then its + + + align:start position:0% +base if you have a strong acid then its +conjugate is ineffective as a base it + + align:start position:0% +conjugate is ineffective as a base it + + + align:start position:0% +conjugate is ineffective as a base it +won't work if you have a strong base + + align:start position:0% +won't work if you have a strong base + + + align:start position:0% +won't work if you have a strong base +then its conjugate is ineffective as an + + align:start position:0% +then its conjugate is ineffective as an + + + align:start position:0% +then its conjugate is ineffective as an +acid and it won't + + align:start position:0% + + + + align:start position:0% + +work all right so base buffering example + + align:start position:0% +work all right so base buffering example + + + align:start position:0% +work all right so base buffering example +same same stuff applies here so um if + + align:start position:0% +same same stuff applies here so um if + + + align:start position:0% +same same stuff applies here so um if +you add a strong acid it will react with + + align:start position:0% +you add a strong acid it will react with + + + align:start position:0% +you add a strong acid it will react with +the base the base will accept the + + align:start position:0% +the base the base will accept the + + + align:start position:0% +the base the base will accept the +protons and uh make more of the nh4 and + + align:start position:0% +protons and uh make more of the nh4 and + + + align:start position:0% +protons and uh make more of the nh4 and +it'll use up the strong + + align:start position:0% +it'll use up the strong + + + align:start position:0% +it'll use up the strong +acid when a strong base is added it'll + + align:start position:0% +acid when a strong base is added it'll + + + align:start position:0% +acid when a strong base is added it'll +react with a conjugate acid and go the + + align:start position:0% +react with a conjugate acid and go the + + + align:start position:0% +react with a conjugate acid and go the +other direction and so you'll form more + + align:start position:0% +other direction and so you'll form more + + + align:start position:0% +other direction and so you'll form more +of the conjugate base in water again the + + align:start position:0% +of the conjugate base in water again the + + + align:start position:0% +of the conjugate base in water again the +pH is staying the same you're using up + + align:start position:0% +pH is staying the same you're using up + + + align:start position:0% +pH is staying the same you're using up +the strong base that's that's + + align:start position:0% +the strong base that's that's + + + align:start position:0% +the strong base that's that's +added so in a in a buffer action you + + align:start position:0% +added so in a in a buffer action you + + + align:start position:0% +added so in a in a buffer action you +have a weak base accepting protons + + align:start position:0% +have a weak base accepting protons + + + align:start position:0% +have a weak base accepting protons +supplied by the strong acid and you have + + align:start position:0% +supplied by the strong acid and you have + + + align:start position:0% +supplied by the strong acid and you have +the conjugate acid of the weak base + + align:start position:0% +the conjugate acid of the weak base + + + align:start position:0% +the conjugate acid of the weak base +transferring protons to the hydroxide + + align:start position:0% +transferring protons to the hydroxide + + + align:start position:0% +transferring protons to the hydroxide +the strong base that's added using that + + align:start position:0% +the strong base that's added using that + + + align:start position:0% +the strong base that's added using that +up as well so again it's about going + + align:start position:0% +up as well so again it's about going + + + align:start position:0% +up as well so again it's about going +both directions of the reaction that + + align:start position:0% +both directions of the reaction that + + + align:start position:0% +both directions of the reaction that +makes something a good buffer so a + + align:start position:0% +makes something a good buffer so a + + + align:start position:0% +makes something a good buffer so a +buffer mixture of weak conjugate acids + + align:start position:0% +buffer mixture of weak conjugate acids + + + align:start position:0% +buffer mixture of weak conjugate acids +and base stabilize the pH of a solution + + align:start position:0% +and base stabilize the pH of a solution + + + align:start position:0% +and base stabilize the pH of a solution +by providing a source or sync for the + + align:start position:0% +by providing a source or sync for the + + + align:start position:0% +by providing a source or sync for the +protons so either um they're they're + + align:start position:0% +protons so either um they're they're + + + align:start position:0% +protons so either um they're they're +providing a source to neutralize the O + + align:start position:0% +providing a source to neutralize the O + + + align:start position:0% +providing a source to neutralize the O +that's minus or a zinc for the protons + + align:start position:0% +that's minus or a zinc for the protons + + + align:start position:0% +that's minus or a zinc for the protons +that are added in the form of acid so + + align:start position:0% +that are added in the form of acid so + + + align:start position:0% +that are added in the form of acid so +the pH stays pretty much the same so you + + align:start position:0% +the pH stays pretty much the same so you + + + align:start position:0% +the pH stays pretty much the same so you +need something that can do this dynamic + + align:start position:0% +need something that can do this dynamic + + + align:start position:0% +need something that can do this dynamic +equilibrium to be a good buffer all + + align:start position:0% +equilibrium to be a good buffer all + + + align:start position:0% +equilibrium to be a good buffer all +right so let me just give you um last + + align:start position:0% +right so let me just give you um last + + + align:start position:0% +right so let me just give you um last +couple minutes an example + + align:start position:0% +couple minutes an example + + + align:start position:0% +couple minutes an example +of why buffering is important from a + + align:start position:0% +of why buffering is important from a + + + align:start position:0% +of why buffering is important from a +human health + + align:start position:0% +human health + + + align:start position:0% +human health +perspective all right so your blood is + + align:start position:0% +perspective all right so your blood is + + + align:start position:0% +perspective all right so your blood is +buffered around a neutral + + align:start position:0% +buffered around a neutral + + + align:start position:0% +buffered around a neutral +range and the buffering agents are shown + + align:start position:0% +range and the buffering agents are shown + + + align:start position:0% +range and the buffering agents are shown +here carbonic acid and bicarbonate are + + align:start position:0% +here carbonic acid and bicarbonate are + + + align:start position:0% +here carbonic acid and bicarbonate are +effective as buffering agents so they + + align:start position:0% +effective as buffering agents so they + + + align:start position:0% +effective as buffering agents so they +can be provide the source or sink for + + align:start position:0% +can be provide the source or sink for + + + align:start position:0% +can be provide the source or sink for +added uh added stress to the system for + + align:start position:0% +added uh added stress to the system for + + + align:start position:0% +added uh added stress to the system for +added acid or added added base so your + + align:start position:0% +added acid or added added base so your + + + align:start position:0% +added acid or added added base so your +blood is buffered and this is really + + align:start position:0% +blood is buffered and this is really + + + align:start position:0% +blood is buffered and this is really +important if your blood if your blood pH + + align:start position:0% +important if your blood if your blood pH + + + align:start position:0% +important if your blood if your blood pH +changes enzymes are designed to work at + + align:start position:0% +changes enzymes are designed to work at + + + align:start position:0% +changes enzymes are designed to work at +particular ph's molecules are not + + align:start position:0% +particular ph's molecules are not + + + align:start position:0% +particular ph's molecules are not +necessarily stable at certain phes so + + align:start position:0% +necessarily stable at certain phes so + + + align:start position:0% +necessarily stable at certain phes so +our body would not work well if it was + + align:start position:0% +our body would not work well if it was + + + align:start position:0% +our body would not work well if it was +not appropriately appropriately buffered + + align:start position:0% +not appropriately appropriately buffered + + + align:start position:0% +not appropriately appropriately buffered +so let me give you an example of a + + align:start position:0% +so let me give you an example of a + + + align:start position:0% +so let me give you an example of a +genetic defect that leads it overwhelms + + align:start position:0% +genetic defect that leads it overwhelms + + + align:start position:0% +genetic defect that leads it overwhelms +the buffering capacity of the blood and + + align:start position:0% +the buffering capacity of the blood and + + + align:start position:0% +the buffering capacity of the blood and +leads to a condition so this is uh an + + align:start position:0% +leads to a condition so this is uh an + + + align:start position:0% +leads to a condition so this is uh an +enzyme that you have in your body it's + + align:start position:0% +enzyme that you have in your body it's + + + align:start position:0% +enzyme that you have in your body it's +in your + + align:start position:0% +in your + + + align:start position:0% +in your +mitochondria and it requires vitamin + + align:start position:0% +mitochondria and it requires vitamin + + + align:start position:0% +mitochondria and it requires vitamin +B12 and this is what the enzyme is + + align:start position:0% +B12 and this is what the enzyme is + + + align:start position:0% +B12 and this is what the enzyme is +involved in it's involved in breaking + + align:start position:0% +involved in it's involved in breaking + + + align:start position:0% +involved in it's involved in breaking +down fatty acids to form energy so most + + align:start position:0% +down fatty acids to form energy so most + + + align:start position:0% +down fatty acids to form energy so most +people like this enzyme they're very + + align:start position:0% +people like this enzyme they're very + + + align:start position:0% +people like this enzyme they're very +happy with this enzyme most people want + + align:start position:0% +happy with this enzyme most people want + + + align:start position:0% +happy with this enzyme most people want +their fat converted to energy and so + + align:start position:0% +their fat converted to energy and so + + + align:start position:0% +their fat converted to energy and so +this enzyme helps out with that going on + + align:start position:0% +this enzyme helps out with that going on + + + align:start position:0% +this enzyme helps out with that going on +all right so what happens if you have a + + align:start position:0% +all right so what happens if you have a + + + align:start position:0% +all right so what happens if you have a +genetic defect or if you don't have + + align:start position:0% +genetic defect or if you don't have + + + align:start position:0% +genetic defect or if you don't have +enough vitamin B12 but in this case + + align:start position:0% +enough vitamin B12 but in this case + + + align:start position:0% +enough vitamin B12 but in this case +we're talking about a genetic defect + + align:start position:0% +we're talking about a genetic defect + + + align:start position:0% +we're talking about a genetic defect +this step is blocked so your body is + + align:start position:0% +this step is blocked so your body is + + + align:start position:0% +this step is blocked so your body is +making a lot of methyl malinal COA and + + align:start position:0% +making a lot of methyl malinal COA and + + + align:start position:0% +making a lot of methyl malinal COA and +it doesn't know what to do with it it's + + align:start position:0% +it doesn't know what to do with it it's + + + align:start position:0% +it doesn't know what to do with it it's +a huge amount and so it actually gets + + align:start position:0% +a huge amount and so it actually gets + + + align:start position:0% +a huge amount and so it actually gets +excreted from the body in the form of an + + align:start position:0% +excreted from the body in the form of an + + + align:start position:0% +excreted from the body in the form of an +acid and so this leads to a condition + + align:start position:0% +acid and so this leads to a condition + + + align:start position:0% +acid and so this leads to a condition +known as methylmalonic aciduria so + + align:start position:0% +known as methylmalonic aciduria so + + + align:start position:0% +known as methylmalonic aciduria so +there's so much of this made you're + + align:start position:0% +there's so much of this made you're + + + align:start position:0% +there's so much of this made you're +excreting like a gram of this acid every + + align:start position:0% +excreting like a gram of this acid every + + + align:start position:0% +excreting like a gram of this acid every +day the blood is overwhelmed it can't + + align:start position:0% +day the blood is overwhelmed it can't + + + align:start position:0% +day the blood is overwhelmed it can't +handle that much acid it's buffering + + align:start position:0% +handle that much acid it's buffering + + + align:start position:0% +handle that much acid it's buffering +capacity isn't that that good all right + + align:start position:0% +capacity isn't that that good all right + + + align:start position:0% +capacity isn't that that good all right +so what causes this problem um so I'll + + align:start position:0% +so what causes this problem um so I'll + + + align:start position:0% +so what causes this problem um so I'll +tell you that this now is the amino acid + + align:start position:0% +tell you that this now is the amino acid + + + align:start position:0% +tell you that this now is the amino acid +sequence of the enzyme so enzymes are + + align:start position:0% +sequence of the enzyme so enzymes are + + + align:start position:0% +sequence of the enzyme so enzymes are +made up of multiple amino acids strung + + align:start position:0% +made up of multiple amino acids strung + + + align:start position:0% +made up of multiple amino acids strung +together in a polypeptide chain and down + + align:start position:0% +together in a polypeptide chain and down + + + align:start position:0% +together in a polypeptide chain and down +here's the number + + align:start position:0% +here's the number + + + align:start position:0% +here's the number +721 so this is a lot of amino acids and + + align:start position:0% +721 so this is a lot of amino acids and + + + align:start position:0% +721 so this is a lot of amino acids and +at the time there were these babies born + + align:start position:0% +at the time there were these babies born + + + align:start position:0% +at the time there were these babies born +with this condition and the doctors + + align:start position:0% +with this condition and the doctors + + + align:start position:0% +with this condition and the doctors +didn't know what to do to treat them and + + align:start position:0% +didn't know what to do to treat them and + + + align:start position:0% +didn't know what to do to treat them and +a lot of the babies died so a number of + + align:start position:0% +a lot of the babies died so a number of + + + align:start position:0% +a lot of the babies died so a number of +them got together and they tried to + + align:start position:0% +them got together and they tried to + + + align:start position:0% +them got together and they tried to +sequence the gene now of course there's + + align:start position:0% +sequence the gene now of course there's + + + align:start position:0% +sequence the gene now of course there's +a Human Genome Project so we know a lot + + align:start position:0% +a Human Genome Project so we know a lot + + + align:start position:0% +a Human Genome Project so we know a lot +of the sequences of genes but the + + align:start position:0% +of the sequences of genes but the + + + align:start position:0% +of the sequences of genes but the +doctors sequenced this Gene and they sat + + align:start position:0% +doctors sequenced this Gene and they sat + + + align:start position:0% +doctors sequenced this Gene and they sat +down with the parents and said okay + + align:start position:0% +down with the parents and said okay + + + align:start position:0% +down with the parents and said okay +there's a mistake right here where that + + align:start position:0% +there's a mistake right here where that + + + align:start position:0% +there's a mistake right here where that +red arrow is it should be a glycine + + align:start position:0% +red arrow is it should be a glycine + + + align:start position:0% +red arrow is it should be a glycine +residue but it's something else all + + align:start position:0% +residue but it's something else all + + + align:start position:0% +residue but it's something else all +right so imagine you're a parent you + + align:start position:0% +right so imagine you're a parent you + + + align:start position:0% +right so imagine you're a parent you +have a kid and the doctor tells you ah + + align:start position:0% +have a kid and the doctor tells you ah + + + align:start position:0% +have a kid and the doctor tells you ah +there's a mistake right here + + align:start position:0% +there's a mistake right here + + + align:start position:0% +there's a mistake right here +okay well that's fantastic what are you + + align:start position:0% +okay well that's fantastic what are you + + + align:start position:0% +okay well that's fantastic what are you +going to do about it well at the time + + align:start position:0% +going to do about it well at the time + + + align:start position:0% +going to do about it well at the time +the doctors had no idea what to do about + + align:start position:0% +the doctors had no idea what to do about + + + align:start position:0% +the doctors had no idea what to do about +it because they didn't really know what + + align:start position:0% +it because they didn't really know what + + + align:start position:0% +it because they didn't really know what +was going on here so um this answer + + align:start position:0% +was going on here so um this answer + + + align:start position:0% +was going on here so um this answer +partly came uh through uh structure + + align:start position:0% +partly came uh through uh structure + + + align:start position:0% +partly came uh through uh structure +determination and they found that + + align:start position:0% +determination and they found that + + + align:start position:0% +determination and they found that +vitamin B12 changes shape when it binds + + align:start position:0% +vitamin B12 changes shape when it binds + + + align:start position:0% +vitamin B12 changes shape when it binds +to a protein so here's vitamin B12 it + + align:start position:0% +to a protein so here's vitamin B12 it + + + align:start position:0% +to a protein so here's vitamin B12 it +has this group uh up attached to the + + align:start position:0% +has this group uh up attached to the + + + align:start position:0% +has this group uh up attached to the +Cobalt when it's free uh when it's bound + + align:start position:0% +Cobalt when it's free uh when it's bound + + + align:start position:0% +Cobalt when it's free uh when it's bound +to the protein it looks like this this + + align:start position:0% +to the protein it looks like this this + + + align:start position:0% +to the protein it looks like this this +long group is extended into the core of + + align:start position:0% +long group is extended into the core of + + + align:start position:0% +long group is extended into the core of +the protein so the protein needs a big + + align:start position:0% +the protein so the protein needs a big + + + align:start position:0% +the protein so the protein needs a big +hole to put this group and so this is a + + align:start position:0% +hole to put this group and so this is a + + + align:start position:0% +hole to put this group and so this is a +model of what the protein looked like + + align:start position:0% +model of what the protein looked like + + + align:start position:0% +model of what the protein looked like +and here's a model of vitamin B12 so we + + align:start position:0% +and here's a model of vitamin B12 so we + + + align:start position:0% +and here's a model of vitamin B12 so we +discovered that it fits like this it's + + align:start position:0% +discovered that it fits like this it's + + + align:start position:0% +discovered that it fits like this it's +fantastic there's a huge hole in the + + align:start position:0% +fantastic there's a huge hole in the + + + align:start position:0% +fantastic there's a huge hole in the +protein into which you can put the + + align:start position:0% +protein into which you can put the + + + align:start position:0% +protein into which you can put the +vitamin so how did nature create a hole + + align:start position:0% +vitamin so how did nature create a hole + + + align:start position:0% +vitamin so how did nature create a hole +how did it make this space for the + + align:start position:0% +how did it make this space for the + + + align:start position:0% +how did it make this space for the +Vitamin to fit and then with the vitamin + + align:start position:0% +Vitamin to fit and then with the vitamin + + + align:start position:0% +Vitamin to fit and then with the vitamin +Bal it's active so what it did was it + + align:start position:0% +Bal it's active so what it did was it + + + align:start position:0% +Bal it's active so what it did was it +put the smallest amino acids it could + + align:start position:0% +put the smallest amino acids it could + + + align:start position:0% +put the smallest amino acids it could +find over + + align:start position:0% +find over + + + align:start position:0% +find over +here now what happens in this mutant + + align:start position:0% +here now what happens in this mutant + + + align:start position:0% +here now what happens in this mutant +protein is that one of those small amino + + align:start position:0% +protein is that one of those small amino + + + align:start position:0% +protein is that one of those small amino +acids was converted to something larger + + align:start position:0% +acids was converted to something larger + + + align:start position:0% +acids was converted to something larger +in the dark blue so this was the protein + + align:start position:0% +in the dark blue so this was the protein + + + align:start position:0% +in the dark blue so this was the protein +that these babies had and the doctors + + align:start position:0% +that these babies had and the doctors + + + align:start position:0% +that these babies had and the doctors +kept giving them more B12 more B12 more + + align:start position:0% +kept giving them more B12 more B12 more + + + align:start position:0% +kept giving them more B12 more B12 more +B12 and it didn't do any good at all + + align:start position:0% +B12 and it didn't do any good at all + + + align:start position:0% +B12 and it didn't do any good at all +because no matter how much you gave you + + align:start position:0% +because no matter how much you gave you + + + align:start position:0% +because no matter how much you gave you +it couldn't bump it was blocked The + + align:start position:0% +it couldn't bump it was blocked The + + + align:start position:0% +it couldn't bump it was blocked The +Binding was blocked so this suggested to + + align:start position:0% +Binding was blocked so this suggested to + + + align:start position:0% +Binding was blocked so this suggested to +doctors that instead of giving them the + + align:start position:0% +doctors that instead of giving them the + + + align:start position:0% +doctors that instead of giving them the +full vitamin B12 and basically take a + + align:start position:0% +full vitamin B12 and basically take a + + + align:start position:0% +full vitamin B12 and basically take a +pair of scissors and chop off part of it + + align:start position:0% +pair of scissors and chop off part of it + + + align:start position:0% +pair of scissors and chop off part of it +and create something that looked more + + align:start position:0% +and create something that looked more + + + align:start position:0% +and create something that looked more +like this and then uh try to see if that + + align:start position:0% +like this and then uh try to see if that + + + align:start position:0% +like this and then uh try to see if that +would then bind to the mutated protein + + align:start position:0% +would then bind to the mutated protein + + + align:start position:0% +would then bind to the mutated protein +so that's the kind of thing that they + + align:start position:0% +so that's the kind of thing that they + + + align:start position:0% +so that's the kind of thing that they +were were looking at trying to alleviate + + align:start position:0% +were were looking at trying to alleviate + + + align:start position:0% +were were looking at trying to alleviate +this particular condition because the + + align:start position:0% +this particular condition because the + + + align:start position:0% +this particular condition because the +buffering of the blood is pretty good if + + align:start position:0% +buffering of the blood is pretty good if + + + align:start position:0% +buffering of the blood is pretty good if +you could restore some activity get rid + + align:start position:0% +you could restore some activity get rid + + + align:start position:0% +you could restore some activity get rid +of some of the acid you might be able to + + align:start position:0% +of some of the acid you might be able to + + + align:start position:0% +of some of the acid you might be able to +have a more normal pH okay have a good + + align:start position:0% +have a more normal pH okay have a good + + + align:start position:0% +have a more normal pH okay have a good +weekend \ No newline at end of file diff --git a/YulNobAZgkA.txt b/YulNobAZgkA.txt new file mode 100644 index 0000000000000000000000000000000000000000..800c328b0f627253a8512e5ac1e10cf41fa5bbfe --- /dev/null +++ b/YulNobAZgkA.txt @@ -0,0 +1,1123 @@ +align:start position:0% + +so Adam light interactions so we will + + align:start position:0% +so Adam light interactions so we will + + + align:start position:0% +so Adam light interactions so we will +focus just on the electric field e field + + align:start position:0% + + + + align:start position:0% + +magnetic field effects are suppressed by + + align:start position:0% +magnetic field effects are suppressed by + + + align:start position:0% +magnetic field effects are suppressed by +the velocity of the electrons divided by + + align:start position:0% +the velocity of the electrons divided by + + + align:start position:0% +the velocity of the electrons divided by +C and that you know is the + + align:start position:0% +C and that you know is the + + + align:start position:0% +C and that you know is the +fine-structure constant so magnetic + + align:start position:0% +fine-structure constant so magnetic + + + align:start position:0% +fine-structure constant so magnetic +field effects are suppressed ignore + + align:start position:0% + + + + align:start position:0% + +magnetic v over c Corrections with v + + align:start position:0% +magnetic v over c Corrections with v + + + align:start position:0% +magnetic v over c Corrections with v +over c again of the order of the + + align:start position:0% +over c again of the order of the + + + align:start position:0% +over c again of the order of the +fine-structure constant we will also + + align:start position:0% +fine-structure constant we will also + + + align:start position:0% +fine-structure constant we will also +think of optical typically optical + + align:start position:0% +think of optical typically optical + + + align:start position:0% +think of optical typically optical +frequencies lambda in the optical range + + align:start position:0% +frequencies lambda in the optical range + + + align:start position:0% +frequencies lambda in the optical range +so from about 4,000 to 8,000 angstroms + + align:start position:0% +so from about 4,000 to 8,000 angstroms + + + align:start position:0% +so from about 4,000 to 8,000 angstroms +and that's much much bigger than a zero + + align:start position:0% +and that's much much bigger than a zero + + + align:start position:0% +and that's much much bigger than a zero +which is about 0.5 angstroms and that's + + align:start position:0% +which is about 0.5 angstroms and that's + + + align:start position:0% +which is about 0.5 angstroms and that's +good for our approximation that the wave + + align:start position:0% +good for our approximation that the wave + + + align:start position:0% +good for our approximation that the wave +is relatively constant being the + + align:start position:0% +is relatively constant being the + + + align:start position:0% +is relatively constant being the +wavelength so large is constant over the + + align:start position:0% +wavelength so large is constant over the + + + align:start position:0% +wavelength so large is constant over the +extent of the atom so we will think of + + align:start position:0% +extent of the atom so we will think of + + + align:start position:0% +extent of the atom so we will think of +the electric field at the atom II at the + + align:start position:0% +the electric field at the atom II at the + + + align:start position:0% +the electric field at the atom II at the +atom + + align:start position:0% + + + + align:start position:0% + +our electric field a lot a bit of + + align:start position:0% +our electric field a lot a bit of + + + align:start position:0% +our electric field a lot a bit of +notation will depend on time and it will + + align:start position:0% +notation will depend on time and it will + + + align:start position:0% +notation will depend on time and it will +be a real function of time times a unit + + align:start position:0% +be a real function of time times a unit + + + align:start position:0% +be a real function of time times a unit +vector to begin with this will get more + + align:start position:0% +vector to begin with this will get more + + + align:start position:0% +vector to begin with this will get more +interesting because we're going to be + + align:start position:0% +interesting because we're going to be + + + align:start position:0% +interesting because we're going to be +dealing with thermal radiation so + + align:start position:0% +dealing with thermal radiation so + + + align:start position:0% +dealing with thermal radiation so +eventually this vector n will be + + align:start position:0% +eventually this vector n will be + + + align:start position:0% +eventually this vector n will be +pointing I will average it over all + + align:start position:0% +pointing I will average it over all + + + align:start position:0% +pointing I will average it over all +directions because thermal radiation + + align:start position:0% +directions because thermal radiation + + + align:start position:0% +directions because thermal radiation +comes with all polarizations and in all + + align:start position:0% +comes with all polarizations and in all + + + align:start position:0% +comes with all polarizations and in all +directions so there will be a little bit + + align:start position:0% +directions so there will be a little bit + + + align:start position:0% +directions so there will be a little bit +of averaging necessary for that that + + align:start position:0% +of averaging necessary for that that + + + align:start position:0% +of averaging necessary for that that +will happen next time as we wrap up this + + align:start position:0% +will happen next time as we wrap up this + + + align:start position:0% +will happen next time as we wrap up this +discussion so this picture is of an atom + + align:start position:0% +discussion so this picture is of an atom + + + align:start position:0% +discussion so this picture is of an atom +sitting here in particular its electron + + align:start position:0% +sitting here in particular its electron + + + align:start position:0% +sitting here in particular its electron +which is the particle that reacts the + + align:start position:0% +which is the particle that reacts the + + + align:start position:0% +which is the particle that reacts the +most of the electric field and there's a + + align:start position:0% +most of the electric field and there's a + + + align:start position:0% +most of the electric field and there's a +unit vector and and there's P of T here + + align:start position:0% + + + + align:start position:0% + +so the electric field E of T is - e not + + align:start position:0% +so the electric field E of T is - e not + + + align:start position:0% +so the electric field E of T is - e not +in our conventions cosine Omega T times + + align:start position:0% +in our conventions cosine Omega T times + + + align:start position:0% +in our conventions cosine Omega T times +the vector n so what is the vector and + + align:start position:0% +the vector n so what is the vector and + + + align:start position:0% +the vector n so what is the vector and +the scalar potential RT is minus R times + + align:start position:0% +the scalar potential RT is minus R times + + + align:start position:0% +the scalar potential RT is minus R times +e of T this is the formula that gives + + align:start position:0% +e of T this is the formula that gives + + + align:start position:0% +e of T this is the formula that gives +you a as minus the gradient of Phi this + + align:start position:0% +you a as minus the gradient of Phi this + + + align:start position:0% +you a as minus the gradient of Phi this +formula is not true in the presence of + + align:start position:0% +formula is not true in the presence of + + + align:start position:0% +formula is not true in the presence of +magnetic fields in general there's a + + align:start position:0% +magnetic fields in general there's a + + + align:start position:0% +magnetic fields in general there's a +time derivative of the vector potential + + align:start position:0% +time derivative of the vector potential + + + align:start position:0% +time derivative of the vector potential +but again we're ignoring magnetic + + align:start position:0% +but again we're ignoring magnetic + + + align:start position:0% +but again we're ignoring magnetic +effects so this is good enough for us if + + align:start position:0% +effects so this is good enough for us if + + + align:start position:0% +effects so this is good enough for us if +you take the gradient of this formula + + align:start position:0% +you take the gradient of this formula + + + align:start position:0% +you take the gradient of this formula +the only are the pen + + align:start position:0% +the only are the pen + + + align:start position:0% +the only are the pen +is here there's no our dependence in + + align:start position:0% +is here there's no our dependence in + + + align:start position:0% +is here there's no our dependence in +this electric field and particular we + + align:start position:0% +this electric field and particular we + + + align:start position:0% +this electric field and particular we +considered the wavelengths to be very + + align:start position:0% +considered the wavelengths to be very + + + align:start position:0% +considered the wavelengths to be very +big and this is good enough so what is + + align:start position:0% +big and this is good enough so what is + + + align:start position:0% +big and this is good enough so what is +the perturbing Hamiltonian due to the + + align:start position:0% +the perturbing Hamiltonian due to the + + + align:start position:0% +the perturbing Hamiltonian due to the +coupling of the electric field to the + + align:start position:0% +coupling of the electric field to the + + + align:start position:0% +coupling of the electric field to the +charge particle and we'll say atom and + + align:start position:0% +charge particle and we'll say atom and + + + align:start position:0% +charge particle and we'll say atom and +we'll put an electron or something and + + align:start position:0% +we'll put an electron or something and + + + align:start position:0% +we'll put an electron or something and +we'll say the charge is Q eventually it + + align:start position:0% +we'll say the charge is Q eventually it + + + align:start position:0% +we'll say the charge is Q eventually it +will be minus e for the electron but + + align:start position:0% +will be minus e for the electron but + + + align:start position:0% +will be minus e for the electron but +let's keep it at Q Delta H is Q times + + align:start position:0% +let's keep it at Q Delta H is Q times + + + align:start position:0% +let's keep it at Q Delta H is Q times +Phi of R and T so this is minus Q times + + align:start position:0% +Phi of R and T so this is minus Q times + + + align:start position:0% +Phi of R and T so this is minus Q times +R times T of T vector or minus Q times R + + align:start position:0% +R times T of T vector or minus Q times R + + + align:start position:0% +R times T of T vector or minus Q times R +times n times e of T so so far simple + + align:start position:0% +times n times e of T so so far simple + + + align:start position:0% +times n times e of T so so far simple +things we're just considering the + + align:start position:0% +things we're just considering the + + + align:start position:0% +things we're just considering the +electric field and how it acts on a + + align:start position:0% +electric field and how it acts on a + + + align:start position:0% +electric field and how it acts on a +charged particle this is of course the + + align:start position:0% +charged particle this is of course the + + + align:start position:0% +charged particle this is of course the +simplest situation we will be + + align:start position:0% +simplest situation we will be + + + align:start position:0% +simplest situation we will be +considering in this course soon in fact + + align:start position:0% +considering in this course soon in fact + + + align:start position:0% +considering in this course soon in fact +starting next lecture the general + + align:start position:0% +starting next lecture the general + + + align:start position:0% +starting next lecture the general +interaction of charged particles with + + align:start position:0% +interaction of charged particles with + + + align:start position:0% +interaction of charged particles with +electromagnetic fields but for the time + + align:start position:0% +electromagnetic fields but for the time + + + align:start position:0% +electromagnetic fields but for the time +being and in this approximation this is + + align:start position:0% +being and in this approximation this is + + + align:start position:0% +being and in this approximation this is +enough and we will define now a dipole + + align:start position:0% +enough and we will define now a dipole + + + align:start position:0% +enough and we will define now a dipole +operator it's something you should keep + + align:start position:0% +operator it's something you should keep + + + align:start position:0% +operator it's something you should keep +in mind it's a the usual thing when you + + align:start position:0% +in mind it's a the usual thing when you + + + align:start position:0% +in mind it's a the usual thing when you +define dipoles if you sum or integrate + + align:start position:0% +define dipoles if you sum or integrate + + + align:start position:0% +define dipoles if you sum or integrate +over charges and position vectors so + + align:start position:0% +over charges and position vectors so + + + align:start position:0% +over charges and position vectors so +this is a dipole operator + + align:start position:0% + + + + align:start position:0% + +operator and emphasize the operator + + align:start position:0% +operator and emphasize the operator + + + align:start position:0% +operator and emphasize the operator +because of the are when you have matrix + + align:start position:0% +because of the are when you have matrix + + + align:start position:0% +because of the are when you have matrix +elements transitions between states + + align:start position:0% +elements transitions between states + + + align:start position:0% +elements transitions between states +everything we will have to deal with + + align:start position:0% +everything we will have to deal with + + + align:start position:0% +everything we will have to deal with +those matrix elements of our and that's + + align:start position:0% +those matrix elements of our and that's + + + align:start position:0% +those matrix elements of our and that's +why we'll have a dipole term there so + + align:start position:0% +why we'll have a dipole term there so + + + align:start position:0% +why we'll have a dipole term there so +Delta H at this moment has become what - + + align:start position:0% +Delta H at this moment has become what - + + + align:start position:0% +Delta H at this moment has become what - +the dipole times the electric field so + + align:start position:0% + + + + align:start position:0% + +so let's do this - the dipole I'll do it + + align:start position:0% +so let's do this - the dipole I'll do it + + + align:start position:0% +so let's do this - the dipole I'll do it +here + + align:start position:0% + + + + align:start position:0% + +mine is the dipole dotted with the + + align:start position:0% +mine is the dipole dotted with the + + + align:start position:0% +mine is the dipole dotted with the +electric field vector or minus B dot and + + align:start position:0% + + + + align:start position:0% + +with - in times the magnitude of the + + align:start position:0% +with - in times the magnitude of the + + + align:start position:0% +with - in times the magnitude of the +electric field or minus B dot and x 2 e + + align:start position:0% +electric field or minus B dot and x 2 e + + + align:start position:0% +electric field or minus B dot and x 2 e +naught cosine of Omega T you know + + align:start position:0% +naught cosine of Omega T you know + + + align:start position:0% +naught cosine of Omega T you know +factors of 2 keep us busy always and we + + align:start position:0% +factors of 2 keep us busy always and we + + + align:start position:0% +factors of 2 keep us busy always and we +have to get them right remember when we + + align:start position:0% +have to get them right remember when we + + + align:start position:0% +have to get them right remember when we +did our definition of perturbed + + align:start position:0% +did our definition of perturbed + + + align:start position:0% +did our definition of perturbed +hamiltonians we said that Delta H was + + align:start position:0% +hamiltonians we said that Delta H was + + + align:start position:0% +hamiltonians we said that Delta H was +going to be equal to 2 H prime cosine of + + align:start position:0% +going to be equal to 2 H prime cosine of + + + align:start position:0% +going to be equal to 2 H prime cosine of +Omega T and our transition amplitude and + + align:start position:0% +Omega T and our transition amplitude and + + + align:start position:0% +Omega T and our transition amplitude and +everything were written in terms of H + + align:start position:0% +everything were written in terms of H + + + align:start position:0% +everything were written in terms of H +prime so this was our definition so at + + align:start position:0% +prime so this was our definition so at + + + align:start position:0% +prime so this was our definition so at +this moment we can isolate H prime here + + align:start position:0% +this moment we can isolate H prime here + + + align:start position:0% +this moment we can isolate H prime here +so H prime is everything except for the + + align:start position:0% +so H prime is everything except for the + + + align:start position:0% +so H prime is everything except for the +2 and the cosine of Omega T so H prime + + align:start position:0% +2 and the cosine of Omega T so H prime + + + align:start position:0% +2 and the cosine of Omega T so H prime +for our problem of atoms in + + align:start position:0% +for our problem of atoms in + + + align:start position:0% +for our problem of atoms in +acting with electromagnetic fields is a + + align:start position:0% +acting with electromagnetic fields is a + + + align:start position:0% +acting with electromagnetic fields is a +dipole interaction and it's given by + + align:start position:0% +dipole interaction and it's given by + + + align:start position:0% +dipole interaction and it's given by +this nice simple formula that's our kind + + align:start position:0% +this nice simple formula that's our kind + + + align:start position:0% +this nice simple formula that's our kind +of important and result so if we have + + align:start position:0% +of important and result so if we have + + + align:start position:0% +of important and result so if we have +this Hamiltonian we have calculated the + + align:start position:0% +this Hamiltonian we have calculated the + + + align:start position:0% +this Hamiltonian we have calculated the +transition rates for or actually more + + align:start position:0% +transition rates for or actually more + + + align:start position:0% +transition rates for or actually more +not the transition rates the probability + + align:start position:0% +not the transition rates the probability + + + align:start position:0% +not the transition rates the probability +for transitions for example from B to a + + align:start position:0% +for transitions for example from B to a + + + align:start position:0% +for transitions for example from B to a +as a function of time when we have a + + align:start position:0% +as a function of time when we have a + + + align:start position:0% +as a function of time when we have a +harmonic perturbation coupled to a + + align:start position:0% +harmonic perturbation coupled to a + + + align:start position:0% +harmonic perturbation coupled to a +two-level system we have a probability + + align:start position:0% +two-level system we have a probability + + + align:start position:0% +two-level system we have a probability +we don't have yet a rate we just have a + + align:start position:0% +we don't have yet a rate we just have a + + + align:start position:0% +we don't have yet a rate we just have a +probability and this is equal to the + + align:start position:0% +probability and this is equal to the + + + align:start position:0% +probability and this is equal to the +other one - the reverse one its 4-h a B + + align:start position:0% +other one - the reverse one its 4-h a B + + + align:start position:0% +other one - the reverse one its 4-h a B +prime squared over H squared sine + + align:start position:0% +prime squared over H squared sine + + + align:start position:0% +prime squared over H squared sine +squared of Omega B a minus Omega over 2t + + align:start position:0% +squared of Omega B a minus Omega over 2t + + + align:start position:0% +squared of Omega B a minus Omega over 2t +over Omega B a minus Omega squared that + + align:start position:0% +over Omega B a minus Omega squared that + + + align:start position:0% +over Omega B a minus Omega squared that +was the formula we had in our case now H + + align:start position:0% +was the formula we had in our case now H + + + align:start position:0% +was the formula we had in our case now H +prime a/b is that so we'll get the + + align:start position:0% +prime a/b is that so we'll get the + + + align:start position:0% +prime a/b is that so we'll get the +following for e zero squared the e zero + + align:start position:0% +following for e zero squared the e zero + + + align:start position:0% +following for e zero squared the e zero +factor here goes out and then we will + + align:start position:0% +factor here goes out and then we will + + + align:start position:0% +factor here goes out and then we will +have the matrix elements of the dipole + + align:start position:0% +have the matrix elements of the dipole + + + align:start position:0% +have the matrix elements of the dipole +operator V dot n a B so it will all be + + align:start position:0% +operator V dot n a B so it will all be + + + align:start position:0% +operator V dot n a B so it will all be +matter of the dipole operator H squared + + align:start position:0% +matter of the dipole operator H squared + + + align:start position:0% +matter of the dipole operator H squared +and the same factor sine squared Omega B + + align:start position:0% +and the same factor sine squared Omega B + + + align:start position:0% +and the same factor sine squared Omega B +a minus Omega over 2t over Omega B a + + align:start position:0% +a minus Omega over 2t over Omega B a + + + align:start position:0% +a minus Omega over 2t over Omega B a +minus Omega squared so this is the + + align:start position:0% +minus Omega squared so this is the + + + align:start position:0% +minus Omega squared so this is the +transition probability + + align:start position:0% +transition probability + + + align:start position:0% +transition probability +don't have a rate but the rate will come + + align:start position:0% +don't have a rate but the rate will come + + + align:start position:0% +don't have a rate but the rate will come +when we integrate over all the photons + + align:start position:0% +when we integrate over all the photons + + + align:start position:0% +when we integrate over all the photons +that contribute to this process and + + align:start position:0% +that contribute to this process and + + + align:start position:0% +that contribute to this process and +we'll get an exact analog of a Fermi + + align:start position:0% +we'll get an exact analog of a Fermi + + + align:start position:0% +we'll get an exact analog of a Fermi +golden rule so that will be next time \ No newline at end of file diff --git a/_62YvNU_yOM.txt b/_62YvNU_yOM.txt new file mode 100644 index 0000000000000000000000000000000000000000..160063ae1cacb1a417d0454ef373fede1087d5ed --- /dev/null +++ b/_62YvNU_yOM.txt @@ -0,0 +1,291 @@ +align:start position:0% + +advice that I would give to educators + + align:start position:0% +advice that I would give to educators + + + align:start position:0% +advice that I would give to educators +also planning or hoping to teach the + + align:start position:0% +also planning or hoping to teach the + + + align:start position:0% +also planning or hoping to teach the +same kind of course material or subject + + align:start position:0% +same kind of course material or subject + + + align:start position:0% +same kind of course material or subject +would be to have somebody of the + + align:start position:0% +would be to have somebody of the + + + align:start position:0% +would be to have somebody of the +diaspora or somebody who can relate to + + align:start position:0% +diaspora or somebody who can relate to + + + align:start position:0% +diaspora or somebody who can relate to +the diaspora teach it it's important to + + align:start position:0% +the diaspora teach it it's important to + + + align:start position:0% +the diaspora teach it it's important to +have people of the background or of the + + align:start position:0% +have people of the background or of the + + + align:start position:0% +have people of the background or of the +diaspora educating it's like who better + + align:start position:0% +diaspora educating it's like who better + + + align:start position:0% +diaspora educating it's like who better +to educate than those that have + + align:start position:0% +to educate than those that have + + + align:start position:0% +to educate than those that have +experienced it themselves or those that + + align:start position:0% +experienced it themselves or those that + + + align:start position:0% +experienced it themselves or those that +you know like come from that area so I + + align:start position:0% +you know like come from that area so I + + + align:start position:0% +you know like come from that area so I +feel like that's probably the biggest + + align:start position:0% +feel like that's probably the biggest + + + align:start position:0% +feel like that's probably the biggest +advice I would give I think maybe other + + align:start position:0% +advice I would give I think maybe other + + + align:start position:0% +advice I would give I think maybe other +advice would be really making sure to + + align:start position:0% +advice would be really making sure to + + + align:start position:0% +advice would be really making sure to +create safe spaces for students to have + + align:start position:0% +create safe spaces for students to have + + + align:start position:0% +create safe spaces for students to have +conversations because I feel like we had + + align:start position:0% +conversations because I feel like we had + + + align:start position:0% +conversations because I feel like we had +that in this class and that you can have + + align:start position:0% +that in this class and that you can have + + + align:start position:0% +that in this class and that you can have +a curriculum that can be very diverse + + align:start position:0% +a curriculum that can be very diverse + + + align:start position:0% +a curriculum that can be very diverse +and like can be very open but if you + + align:start position:0% +and like can be very open but if you + + + align:start position:0% +and like can be very open but if you +don't create an environment and we're + + align:start position:0% +don't create an environment and we're + + + align:start position:0% +don't create an environment and we're +like in which students can like openly + + align:start position:0% +like in which students can like openly + + + align:start position:0% +like in which students can like openly +speak about things and openly talk about + + align:start position:0% +speak about things and openly talk about + + + align:start position:0% +speak about things and openly talk about +things like it's not gonna matter and I + + align:start position:0% +things like it's not gonna matter and I + + + align:start position:0% +things like it's not gonna matter and I +feel like it limits the kinds of + + align:start position:0% +feel like it limits the kinds of + + + align:start position:0% +feel like it limits the kinds of +discussions you have and I feel like + + align:start position:0% +discussions you have and I feel like + + + align:start position:0% +discussions you have and I feel like +we've had a lot of great discussions in + + align:start position:0% +we've had a lot of great discussions in + + + align:start position:0% +we've had a lot of great discussions in +this class because the environment has + + align:start position:0% +this class because the environment has + + + align:start position:0% +this class because the environment has +been it's been a safe environment you + + align:start position:0% +been it's been a safe environment you + + + align:start position:0% +been it's been a safe environment you +know when people can voice their + + align:start position:0% +know when people can voice their + + + align:start position:0% +know when people can voice their +opinions and things have gotten very + + align:start position:0% +opinions and things have gotten very + + + align:start position:0% +opinions and things have gotten very +personal in this class sometimes you + + align:start position:0% +personal in this class sometimes you + + + align:start position:0% +personal in this class sometimes you +know there have been one or two + + align:start position:0% +know there have been one or two + + + align:start position:0% +know there have been one or two +instances where students that have been + + align:start position:0% +instances where students that have been + + + align:start position:0% +instances where students that have been +left you know because they were so + + align:start position:0% +left you know because they were so + + + align:start position:0% +left you know because they were so +emotional and so like yeah it's not it's + + align:start position:0% +emotional and so like yeah it's not it's + + + align:start position:0% +emotional and so like yeah it's not it's +not just about the curriculum - it's + + align:start position:0% +not just about the curriculum - it's + + + align:start position:0% +not just about the curriculum - it's +also about the space that you create \ No newline at end of file diff --git a/_jz3HWBmruo.txt b/_jz3HWBmruo.txt new file mode 100644 index 0000000000000000000000000000000000000000..6a07b44aa470a30105423491c5bcf43b96f09dea --- /dev/null +++ b/_jz3HWBmruo.txt @@ -0,0 +1,2531 @@ +align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +in most of our calculations of safety + + align:start position:0% +in most of our calculations of safety + + + align:start position:0% +in most of our calculations of safety +we're going to be interested in the + + align:start position:0% +we're going to be interested in the + + + align:start position:0% +we're going to be interested in the +steady state average transmission rate + + align:start position:0% +steady state average transmission rate + + + align:start position:0% +steady state average transmission rate +between individuals in a room + + align:start position:0% +between individuals in a room + + + align:start position:0% +between individuals in a room +after the aerosol particles have built + + align:start position:0% +after the aerosol particles have built + + + align:start position:0% +after the aerosol particles have built +up to a steady state + + align:start position:0% +up to a steady state + + + align:start position:0% +up to a steady state +but let's briefly talk about the + + align:start position:0% +but let's briefly talk about the + + + align:start position:0% +but let's briefly talk about the +transient buildup and how to take that + + align:start position:0% +transient buildup and how to take that + + + align:start position:0% +transient buildup and how to take that +into account + + align:start position:0% +into account + + + align:start position:0% +into account +just as an aside in this board here so + + align:start position:0% +just as an aside in this board here so + + + align:start position:0% +just as an aside in this board here so +here + + align:start position:0% +here + + + align:start position:0% +here +is the general expression for the + + align:start position:0% +is the general expression for the + + + align:start position:0% +is the general expression for the +transmission rate that we described + + align:start position:0% +transmission rate that we described + + + align:start position:0% +transmission rate that we described +which depends on the breathing rate + + align:start position:0% +which depends on the breathing rate + + + align:start position:0% +which depends on the breathing rate +squared uh the + + align:start position:0% +squared uh the + + + align:start position:0% +squared uh the +the volume of the room it's an integral + + align:start position:0% +the volume of the room it's an integral + + + align:start position:0% +the volume of the room it's an integral +over all the different drop sizes + + align:start position:0% +over all the different drop sizes + + + align:start position:0% +over all the different drop sizes +where nq is a lumped distribution + + align:start position:0% +where nq is a lumped distribution + + + align:start position:0% +where nq is a lumped distribution +of the number of infection quanta per + + align:start position:0% +of the number of infection quanta per + + + align:start position:0% +of the number of infection quanta per +volume + + align:start position:0% +volume + + + align:start position:0% +volume +per per radius + + align:start position:0% +per per radius + + + align:start position:0% +per per radius +and then pm is the mass transmission + + align:start position:0% +and then pm is the mass transmission + + + align:start position:0% +and then pm is the mass transmission +factor which depends on radius + + align:start position:0% +factor which depends on radius + + + align:start position:0% +factor which depends on radius +and lambda c is the total relaxation + + align:start position:0% +and lambda c is the total relaxation + + + align:start position:0% +and lambda c is the total relaxation +rate involving sedimentation + + align:start position:0% +rate involving sedimentation + + + align:start position:0% +rate involving sedimentation +and or settling and + + align:start position:0% +and or settling and + + + align:start position:0% +and or settling and +viral deactivation and filtration and + + align:start position:0% +viral deactivation and filtration and + + + align:start position:0% +viral deactivation and filtration and +that also depends of course on r and + + align:start position:0% +that also depends of course on r and + + + align:start position:0% +that also depends of course on r and +that + + align:start position:0% +that + + + align:start position:0% +that +lambda c of r also ends up in the + + align:start position:0% +lambda c of r also ends up in the + + + align:start position:0% +lambda c of r also ends up in the +exponent here so that actually + + align:start position:0% +exponent here so that actually + + + align:start position:0% +exponent here so that actually +that that rate of relaxation of the + + align:start position:0% +that that rate of relaxation of the + + + align:start position:0% +that that rate of relaxation of the +concentration in the air + + align:start position:0% +concentration in the air + + + align:start position:0% +concentration in the air +is also setting the time scale lambda c + + align:start position:0% +is also setting the time scale lambda c + + + align:start position:0% +is also setting the time scale lambda c +inverse for the buildup of those aerosol + + align:start position:0% +inverse for the buildup of those aerosol + + + align:start position:0% +inverse for the buildup of those aerosol +droplets in the air and so that's this + + align:start position:0% +droplets in the air and so that's this + + + align:start position:0% +droplets in the air and so that's this +factor here this is basically the + + align:start position:0% +factor here this is basically the + + + align:start position:0% +factor here this is basically the +the transient term + + align:start position:0% +the transient term + + + align:start position:0% +the transient term +is this term and then this term + + align:start position:0% +is this term and then this term + + + align:start position:0% +is this term and then this term +the one is the steady term okay + + align:start position:0% +the one is the steady term okay + + + align:start position:0% +the one is the steady term okay +so we're interested now what's the + + align:start position:0% +so we're interested now what's the + + + align:start position:0% +so we're interested now what's the +effect of the transient now before we + + align:start position:0% +effect of the transient now before we + + + align:start position:0% +effect of the transient now before we +get to that + + align:start position:0% +get to that + + + align:start position:0% +get to that +if we forget about the transient now we + + align:start position:0% +if we forget about the transient now we + + + align:start position:0% +if we forget about the transient now we +just have the steady state + + align:start position:0% +just have the steady state + + + align:start position:0% +just have the steady state +then we have introduced beta bar as the + + align:start position:0% +then we have introduced beta bar as the + + + align:start position:0% +then we have introduced beta bar as the +sort of constant + + align:start position:0% +sort of constant + + + align:start position:0% +sort of constant +steady state value transmission and + + align:start position:0% +steady state value transmission and + + + align:start position:0% +steady state value transmission and +through this definition here by doing + + align:start position:0% +through this definition here by doing + + + align:start position:0% +through this definition here by doing +these integrals we have defined an + + align:start position:0% +these integrals we have defined an + + + align:start position:0% +these integrals we have defined an +effective + + align:start position:0% +effective + + + align:start position:0% +effective +radius r bar which is sort of + + align:start position:0% +radius r bar which is sort of + + + align:start position:0% +radius r bar which is sort of +where you evaluate the mass transmission + + align:start position:0% +where you evaluate the mass transmission + + + align:start position:0% +where you evaluate the mass transmission +factor and also the + + align:start position:0% +factor and also the + + + align:start position:0% +factor and also the +filtration or the relaxation rate in + + align:start position:0% +filtration or the relaxation rate in + + + align:start position:0% +filtration or the relaxation rate in +order to make these two + + align:start position:0% +order to make these two + + + align:start position:0% +order to make these two +uh values equal so that's actually our + + align:start position:0% +uh values equal so that's actually our + + + align:start position:0% +uh values equal so that's actually our +definition of effective radius + + align:start position:0% +definition of effective radius + + + align:start position:0% +definition of effective radius +and so now looking at the uh at the + + align:start position:0% +and so now looking at the uh at the + + + align:start position:0% +and so now looking at the uh at the +transient term + + align:start position:0% +transient term + + + align:start position:0% +transient term +uh let's ask ourselves what is the + + align:start position:0% +uh let's ask ourselves what is the + + + align:start position:0% +uh let's ask ourselves what is the +average transmission rate up to a + + align:start position:0% +average transmission rate up to a + + + align:start position:0% +average transmission rate up to a +certain time + + align:start position:0% +certain time + + + align:start position:0% +certain time +tau so that would be we divide by a time + + align:start position:0% +tau so that would be we divide by a time + + + align:start position:0% +tau so that would be we divide by a time +tau + + align:start position:0% +tau + + + align:start position:0% +tau +and we ask ourselves up to that time you + + align:start position:0% +and we ask ourselves up to that time you + + + align:start position:0% +and we ask ourselves up to that time you +know what is the + + align:start position:0% +know what is the + + + align:start position:0% +know what is the +average transmission rate so we + + align:start position:0% +average transmission rate so we + + + align:start position:0% +average transmission rate so we +integrate beta dt from 0 to tau + + align:start position:0% +integrate beta dt from 0 to tau + + + align:start position:0% +integrate beta dt from 0 to tau +and then divide by divide by tau so what + + align:start position:0% +and then divide by divide by tau so what + + + align:start position:0% +and then divide by divide by tau so what +would that be + + align:start position:0% +would that be + + + align:start position:0% +would that be +well we can take this time integral and + + align:start position:0% +well we can take this time integral and + + + align:start position:0% +well we can take this time integral and +bring it inside the + + align:start position:0% +bring it inside the + + + align:start position:0% +bring it inside the +radius integral and write this as + + align:start position:0% +radius integral and write this as + + + align:start position:0% +radius integral and write this as +qb squared over v integral + + align:start position:0% +qb squared over v integral + + + align:start position:0% +qb squared over v integral +0 to infinity of pm + + align:start position:0% +0 to infinity of pm + + + align:start position:0% +0 to infinity of pm +squared and q of lambda c keep in mind + + align:start position:0% +squared and q of lambda c keep in mind + + + align:start position:0% +squared and q of lambda c keep in mind +all those + + align:start position:0% +all those + + + align:start position:0% +all those +factors depend on r times + + align:start position:0% +factors depend on r times + + + align:start position:0% +factors depend on r times +now an integral from 0 to tau and i'll + + align:start position:0% +now an integral from 0 to tau and i'll + + + align:start position:0% +now an integral from 0 to tau and i'll +put this in brackets + + align:start position:0% +put this in brackets + + + align:start position:0% +put this in brackets +of 1 minus e to the minus lambda c + + align:start position:0% +of 1 minus e to the minus lambda c + + + align:start position:0% +of 1 minus e to the minus lambda c +which depends on r times t + + align:start position:0% + + + + align:start position:0% + +divided by divided by + + align:start position:0% +divided by divided by + + + align:start position:0% +divided by divided by +tau dt + + align:start position:0% + + + + align:start position:0% + +and then dr so switching the order of + + align:start position:0% +and then dr so switching the order of + + + align:start position:0% +and then dr so switching the order of +integration where we're going to do + + align:start position:0% +integration where we're going to do + + + align:start position:0% +integration where we're going to do +the time integral first okay + + align:start position:0% +the time integral first okay + + + align:start position:0% +the time integral first okay +and so what we have here if we just look + + align:start position:0% +and so what we have here if we just look + + + align:start position:0% +and so what we have here if we just look +only at this expression right here + + align:start position:0% + + + + align:start position:0% + +we can write this as a sum of a steady + + align:start position:0% +we can write this as a sum of a steady + + + align:start position:0% +we can write this as a sum of a steady +state term + + align:start position:0% +state term + + + align:start position:0% +state term +so when it's just one this is the + + align:start position:0% +so when it's just one this is the + + + align:start position:0% +so when it's just one this is the +integral of one over tau you know from + + align:start position:0% +integral of one over tau you know from + + + align:start position:0% +integral of one over tau you know from +zero to tau so that's just + + align:start position:0% +zero to tau so that's just + + + align:start position:0% +zero to tau so that's just +one so that's the steady state + + align:start position:0% +one so that's the steady state + + + align:start position:0% +one so that's the steady state +contribution + + align:start position:0% + + + + align:start position:0% + +one plus and there's a transient + + align:start position:0% +one plus and there's a transient + + + align:start position:0% +one plus and there's a transient +contribution we have to do this integral + + align:start position:0% +contribution we have to do this integral + + + align:start position:0% +contribution we have to do this integral +here + + align:start position:0% +here + + + align:start position:0% +here +so that's e to the minus lambda c + + align:start position:0% +so that's e to the minus lambda c + + + align:start position:0% +so that's e to the minus lambda c +of t over lambda c + + align:start position:0% +of t over lambda c + + + align:start position:0% +of t over lambda c +tau evaluated from zero + + align:start position:0% +tau evaluated from zero + + + align:start position:0% +tau evaluated from zero +to tau and so we'll come back to this in + + align:start position:0% +to tau and so we'll come back to this in + + + align:start position:0% +to tau and so we'll come back to this in +just a moment and evaluate that + + align:start position:0% +just a moment and evaluate that + + + align:start position:0% +just a moment and evaluate that +but just to draw a picture maybe first + + align:start position:0% +but just to draw a picture maybe first + + + align:start position:0% +but just to draw a picture maybe first +of what we're looking at here + + align:start position:0% +of what we're looking at here + + + align:start position:0% +of what we're looking at here +the average transmission rate + + align:start position:0% + + + + align:start position:0% + +as a function of this averaging time tau + + align:start position:0% +as a function of this averaging time tau + + + align:start position:0% +as a function of this averaging time tau +well eventually of course it tends to + + align:start position:0% +well eventually of course it tends to + + + align:start position:0% +well eventually of course it tends to +the steady state value + + align:start position:0% + + + + align:start position:0% + +but it does so in a certain way we're + + align:start position:0% +but it does so in a certain way we're + + + align:start position:0% +but it does so in a certain way we're +going to calculate like that + + align:start position:0% +going to calculate like that + + + align:start position:0% +going to calculate like that +where the time for that transmission or + + align:start position:0% +where the time for that transmission or + + + align:start position:0% +where the time for that transmission or +for that transition is the inverse of + + align:start position:0% +for that transition is the inverse of + + + align:start position:0% +for that transition is the inverse of +the relaxation time + + align:start position:0% +the relaxation time + + + align:start position:0% +the relaxation time +although there's not a precise value of + + align:start position:0% +although there's not a precise value of + + + align:start position:0% +although there's not a precise value of +that but if we want to keep actually a + + align:start position:0% +that but if we want to keep actually a + + + align:start position:0% +that but if we want to keep actually a +scale for it it's going to be evaluate + + align:start position:0% +scale for it it's going to be evaluate + + + align:start position:0% +scale for it it's going to be evaluate +that value + + align:start position:0% +that value + + + align:start position:0% +that value +r bar that i mentioned that gives you a + + align:start position:0% +r bar that i mentioned that gives you a + + + align:start position:0% +r bar that i mentioned that gives you a +rough sense of the overall location so + + align:start position:0% +rough sense of the overall location so + + + align:start position:0% +rough sense of the overall location so +this is this build up of the aerosol + + align:start position:0% +this is this build up of the aerosol + + + align:start position:0% +this is this build up of the aerosol +concentration in the room once the + + align:start position:0% +concentration in the room once the + + + align:start position:0% +concentration in the room once the +infected person is entered and + + align:start position:0% +infected person is entered and + + + align:start position:0% +infected person is entered and +eventually they serve a steady + + align:start position:0% +eventually they serve a steady + + + align:start position:0% +eventually they serve a steady +transmission rate to everyone else in + + align:start position:0% +transmission rate to everyone else in + + + align:start position:0% +transmission rate to everyone else in +the room + + align:start position:0% +the room + + + align:start position:0% +the room +so let's let's continue calculating this + + align:start position:0% +so let's let's continue calculating this + + + align:start position:0% +so let's let's continue calculating this +right here now + + align:start position:0% +right here now + + + align:start position:0% +right here now +so this is the transient + + align:start position:0% + + + + align:start position:0% + +and i can write this as 1 + + align:start position:0% +and i can write this as 1 + + + align:start position:0% +and i can write this as 1 +um and if i evaluate here i can put it + + align:start position:0% +um and if i evaluate here i can put it + + + align:start position:0% +um and if i evaluate here i can put it +this way as minus and then i evaluate + + align:start position:0% +this way as minus and then i evaluate + + + align:start position:0% +this way as minus and then i evaluate +first to the lower limit which gives me + + align:start position:0% +first to the lower limit which gives me + + + align:start position:0% +first to the lower limit which gives me +another one + + align:start position:0% +another one + + + align:start position:0% +another one +minus and then evaluate the upper limit + + align:start position:0% +minus and then evaluate the upper limit + + + align:start position:0% +minus and then evaluate the upper limit +is tau e to the minus + + align:start position:0% +is tau e to the minus + + + align:start position:0% +is tau e to the minus +lambda c tau over lambda c + + align:start position:0% +lambda c tau over lambda c + + + align:start position:0% +lambda c tau over lambda c +tau okay and now i'll use + + align:start position:0% +tau okay and now i'll use + + + align:start position:0% +tau okay and now i'll use +an approximation that helps me get a + + align:start position:0% +an approximation that helps me get a + + + align:start position:0% +an approximation that helps me get a +simple analytical result so i should + + align:start position:0% +simple analytical result so i should + + + align:start position:0% +simple analytical result so i should +mention + + align:start position:0% +mention + + + align:start position:0% +mention +as soon as we have exponentials and + + align:start position:0% +as soon as we have exponentials and + + + align:start position:0% +as soon as we have exponentials and +polynomial factors it can be difficult + + align:start position:0% +polynomial factors it can be difficult + + + align:start position:0% +polynomial factors it can be difficult +to solve equations for for example what + + align:start position:0% +to solve equations for for example what + + + align:start position:0% +to solve equations for for example what +is the bound + + align:start position:0% +is the bound + + + align:start position:0% +is the bound +on the occupancy or the time in the room + + align:start position:0% +on the occupancy or the time in the room + + + align:start position:0% +on the occupancy or the time in the room +you know or the ventilation + + align:start position:0% +you know or the ventilation + + + align:start position:0% +you know or the ventilation +we'd like to get a simple formula and so + + align:start position:0% +we'd like to get a simple formula and so + + + align:start position:0% +we'd like to get a simple formula and so +uh there's a nice approximation i can + + align:start position:0% +uh there's a nice approximation i can + + + align:start position:0% +uh there's a nice approximation i can +make + + align:start position:0% +make + + + align:start position:0% +make +which is that 1 minus e to the minus + + align:start position:0% +which is that 1 minus e to the minus + + + align:start position:0% +which is that 1 minus e to the minus +x over x is not + + align:start position:0% +x over x is not + + + align:start position:0% +x over x is not +too far off from 1 over 1 plus + + align:start position:0% +too far off from 1 over 1 plus + + + align:start position:0% +too far off from 1 over 1 plus +x it turns out so it's not a perfect + + align:start position:0% +x it turns out so it's not a perfect + + + align:start position:0% +x it turns out so it's not a perfect +match you can try plotting these two + + align:start position:0% +match you can try plotting these two + + + align:start position:0% +match you can try plotting these two +functions + + align:start position:0% +functions + + + align:start position:0% +functions +but it's it's it's a reasonable + + align:start position:0% +but it's it's it's a reasonable + + + align:start position:0% +but it's it's it's a reasonable +approximation given that everything + + align:start position:0% +approximation given that everything + + + align:start position:0% +approximation given that everything +we're doing in this calculation + + align:start position:0% +we're doing in this calculation + + + align:start position:0% +we're doing in this calculation +when applied to a real situation is + + align:start position:0% +when applied to a real situation is + + + align:start position:0% +when applied to a real situation is +going to be off you know by some + + align:start position:0% +going to be off you know by some + + + align:start position:0% +going to be off you know by some +uh uncertainty which could be you know + + align:start position:0% +uh uncertainty which could be you know + + + align:start position:0% +uh uncertainty which could be you know +factor of two or three + + align:start position:0% +factor of two or three + + + align:start position:0% +factor of two or three +uh this is actually going to be more + + align:start position:0% +uh this is actually going to be more + + + align:start position:0% +uh this is actually going to be more +than good enough of our approximation + + align:start position:0% +than good enough of our approximation + + + align:start position:0% +than good enough of our approximation +for us + + align:start position:0% +for us + + + align:start position:0% +for us +so if i make that approximation then + + align:start position:0% +so if i make that approximation then + + + align:start position:0% +so if i make that approximation then +what i have here + + align:start position:0% +what i have here + + + align:start position:0% +what i have here +is that this thing is 1 over 1 + + align:start position:0% +is that this thing is 1 over 1 + + + align:start position:0% +is that this thing is 1 over 1 +plus 1 plus + + align:start position:0% +plus 1 plus + + + align:start position:0% +plus 1 plus +x here and so we end up with + + align:start position:0% +x here and so we end up with + + + align:start position:0% +x here and so we end up with +1 minus 1 over 1 plus lambda c + + align:start position:0% +1 minus 1 over 1 plus lambda c + + + align:start position:0% +1 minus 1 over 1 plus lambda c +tau and when i combine those two terms i + + align:start position:0% +tau and when i combine those two terms i + + + align:start position:0% +tau and when i combine those two terms i +end up with lambda c + + align:start position:0% +end up with lambda c + + + align:start position:0% +end up with lambda c +tau over one plus lambda c + + align:start position:0% +tau over one plus lambda c + + + align:start position:0% +tau over one plus lambda c +tau okay so that's + + align:start position:0% +tau okay so that's + + + align:start position:0% +tau okay so that's +uh this is my approximation in fact i + + align:start position:0% +uh this is my approximation in fact i + + + align:start position:0% +uh this is my approximation in fact i +can further then + + align:start position:0% +can further then + + + align:start position:0% +can further then +write that as 1 over 1 plus + + align:start position:0% +write that as 1 over 1 plus + + + align:start position:0% +write that as 1 over 1 plus +lambda c tau inverse dividing the + + align:start position:0% +lambda c tau inverse dividing the + + + align:start position:0% +lambda c tau inverse dividing the +numerator denominator by lambda c + + align:start position:0% +numerator denominator by lambda c + + + align:start position:0% +numerator denominator by lambda c +tau okay so i'm just making some + + align:start position:0% +tau okay so i'm just making some + + + align:start position:0% +tau okay so i'm just making some +approximations here that allow me to get + + align:start position:0% +approximations here that allow me to get + + + align:start position:0% +approximations here that allow me to get +a very simple expression in the end + + align:start position:0% +a very simple expression in the end + + + align:start position:0% +a very simple expression in the end +for my my safety guideline + + align:start position:0% +for my my safety guideline + + + align:start position:0% +for my my safety guideline +taking into account this transient build + + align:start position:0% +taking into account this transient build + + + align:start position:0% +taking into account this transient build +up here + + align:start position:0% +up here + + + align:start position:0% +up here +so remember that the bound we have is + + align:start position:0% +so remember that the bound we have is + + + align:start position:0% +so remember that the bound we have is +on the indoor reproductive number which + + align:start position:0% +on the indoor reproductive number which + + + align:start position:0% +on the indoor reproductive number which +is + + align:start position:0% +is + + + align:start position:0% +is +n minus 1 times the integral + + align:start position:0% +n minus 1 times the integral + + + align:start position:0% +n minus 1 times the integral +of to tau of beta + + align:start position:0% +of to tau of beta + + + align:start position:0% +of to tau of beta +dt so what is that that's just + + align:start position:0% +dt so what is that that's just + + + align:start position:0% +dt so what is that that's just +the sort of time average beta times + + align:start position:0% +the sort of time average beta times + + + align:start position:0% +the sort of time average beta times +tau okay so this bound is actually n + + align:start position:0% +tau okay so this bound is actually n + + + align:start position:0% +tau okay so this bound is actually n +minus one time average beta times tau + + align:start position:0% +minus one time average beta times tau + + + align:start position:0% +minus one time average beta times tau +and then our guideline of course is to + + align:start position:0% +and then our guideline of course is to + + + align:start position:0% +and then our guideline of course is to +make this less + + align:start position:0% +make this less + + + align:start position:0% +make this less +than our tolerance epsilon okay + + align:start position:0% +than our tolerance epsilon okay + + + align:start position:0% +than our tolerance epsilon okay +and so what that means then is using + + align:start position:0% +and so what that means then is using + + + align:start position:0% +and so what that means then is using +this result you can see that + + align:start position:0% +this result you can see that + + + align:start position:0% +this result you can see that +i just get the rest so if i look at the + + align:start position:0% +i just get the rest so if i look at the + + + align:start position:0% +i just get the rest so if i look at the +expression for beta + + align:start position:0% +expression for beta + + + align:start position:0% +expression for beta +bracket is just the steady state + + align:start position:0% +bracket is just the steady state + + + align:start position:0% +bracket is just the steady state +expression + + align:start position:0% +expression + + + align:start position:0% +expression +times this factor so basically this is + + align:start position:0% +times this factor so basically this is + + + align:start position:0% +times this factor so basically this is +kind of the the factor that corrects for + + align:start position:0% +kind of the the factor that corrects for + + + align:start position:0% +kind of the the factor that corrects for +transient effects + + align:start position:0% +transient effects + + + align:start position:0% +transient effects +again with just a simple approximation + + align:start position:0% +again with just a simple approximation + + + align:start position:0% +again with just a simple approximation +so i can then write that my guideline + + align:start position:0% +so i can then write that my guideline + + + align:start position:0% +so i can then write that my guideline +now has a modified form which is that + + align:start position:0% +now has a modified form which is that + + + align:start position:0% +now has a modified form which is that +n minus 1 times tau + + align:start position:0% +n minus 1 times tau + + + align:start position:0% +n minus 1 times tau +is less than epsilon over the + + align:start position:0% +is less than epsilon over the + + + align:start position:0% +is less than epsilon over the +time average beta up to time tau + + align:start position:0% +time average beta up to time tau + + + align:start position:0% +time average beta up to time tau +and this is approximately equal to + + align:start position:0% +and this is approximately equal to + + + align:start position:0% +and this is approximately equal to +epsilon over beta steady state + + align:start position:0% +epsilon over beta steady state + + + align:start position:0% +epsilon over beta steady state +times this factor here if i multiply + + align:start position:0% +times this factor here if i multiply + + + align:start position:0% +times this factor here if i multiply +that to the other side + + align:start position:0% +that to the other side + + + align:start position:0% +that to the other side +um i just get 1 plus 1 + + align:start position:0% +um i just get 1 plus 1 + + + align:start position:0% +um i just get 1 plus 1 +over is lambda c of r bar tau + + align:start position:0% +over is lambda c of r bar tau + + + align:start position:0% +over is lambda c of r bar tau +so + + align:start position:0% + + + + align:start position:0% + +so basically this right here + + align:start position:0% +so basically this right here + + + align:start position:0% +so basically this right here +is the transient + + align:start position:0% + + + + align:start position:0% + +correction or modification + + align:start position:0% +correction or modification + + + align:start position:0% +correction or modification +and this + + align:start position:0% +and this + + + align:start position:0% +and this +is the steady state formula which we + + align:start position:0% +is the steady state formula which we + + + align:start position:0% +is the steady state formula which we +will more typically + + align:start position:0% +will more typically + + + align:start position:0% +will more typically +be using now why do we care about the + + align:start position:0% +be using now why do we care about the + + + align:start position:0% +be using now why do we care about the +transient + + align:start position:0% +transient + + + align:start position:0% +transient +well first of all you can see that the + + align:start position:0% +well first of all you can see that the + + + align:start position:0% +well first of all you can see that the +by using the transient we are being + + align:start position:0% +by using the transient we are being + + + align:start position:0% +by using the transient we are being +uh less conservative so if we want to be + + align:start position:0% +uh less conservative so if we want to be + + + align:start position:0% +uh less conservative so if we want to be +very conservative we can say you know + + align:start position:0% +very conservative we can say you know + + + align:start position:0% +very conservative we can say you know +what + + align:start position:0% +what + + + align:start position:0% +what +let's just assume the second that the + + align:start position:0% +let's just assume the second that the + + + align:start position:0% +let's just assume the second that the +affected person enters the room + + align:start position:0% +affected person enters the room + + + align:start position:0% +affected person enters the room +boom the transition rate goes right to + + align:start position:0% +boom the transition rate goes right to + + + align:start position:0% +boom the transition rate goes right to +the maximum value + + align:start position:0% +the maximum value + + + align:start position:0% +the maximum value +that's the most conservative so + + align:start position:0% +that's the most conservative so + + + align:start position:0% +that's the most conservative so +generally using the steady state + + align:start position:0% +generally using the steady state + + + align:start position:0% +generally using the steady state +is more conservative + + align:start position:0% +is more conservative + + + align:start position:0% +is more conservative +so that's one reason we like to use it + + align:start position:0% +so that's one reason we like to use it + + + align:start position:0% +so that's one reason we like to use it +also it gives you a simpler formula why + + align:start position:0% +also it gives you a simpler formula why + + + align:start position:0% +also it gives you a simpler formula why +add a bunch of factors to a formula that + + align:start position:0% +add a bunch of factors to a formula that + + + align:start position:0% +add a bunch of factors to a formula that +only make it less conservative + + align:start position:0% +only make it less conservative + + + align:start position:0% +only make it less conservative +and you know we've made a lot of + + align:start position:0% +and you know we've made a lot of + + + align:start position:0% +and you know we've made a lot of +assumptions in this model so it makes + + align:start position:0% +assumptions in this model so it makes + + + align:start position:0% +assumptions in this model so it makes +sense maybe let's not worry about it + + align:start position:0% +sense maybe let's not worry about it + + + align:start position:0% +sense maybe let's not worry about it +however i do actually like to include it + + align:start position:0% +however i do actually like to include it + + + align:start position:0% +however i do actually like to include it +for certain examples + + align:start position:0% +for certain examples + + + align:start position:0% +for certain examples +because it allows you to capture the + + align:start position:0% +because it allows you to capture the + + + align:start position:0% +because it allows you to capture the +intuition we all have + + align:start position:0% +intuition we all have + + + align:start position:0% +intuition we all have +that when the time goes to zero the risk + + align:start position:0% +that when the time goes to zero the risk + + + align:start position:0% +that when the time goes to zero the risk +also has to go to zero + + align:start position:0% +also has to go to zero + + + align:start position:0% +also has to go to zero +which you don't get from steady state + + align:start position:0% +which you don't get from steady state + + + align:start position:0% +which you don't get from steady state +right if this bumps up right away then + + align:start position:0% +right if this bumps up right away then + + + align:start position:0% +right if this bumps up right away then +you could be spending like two seconds + + align:start position:0% +you could be spending like two seconds + + + align:start position:0% +you could be spending like two seconds +in a room and you have + + align:start position:0% +in a room and you have + + + align:start position:0% +in a room and you have +a chance in fact a chance of getting + + align:start position:0% +a chance in fact a chance of getting + + + align:start position:0% +a chance in fact a chance of getting +infected right away which is actually + + align:start position:0% +infected right away which is actually + + + align:start position:0% +infected right away which is actually +not right there has to be some time + + align:start position:0% +not right there has to be some time + + + align:start position:0% +not right there has to be some time +physically for transmission to happen + + align:start position:0% +physically for transmission to happen + + + align:start position:0% +physically for transmission to happen +through these droplets from one person + + align:start position:0% +through these droplets from one person + + + align:start position:0% +through these droplets from one person +to another + + align:start position:0% +to another + + + align:start position:0% +to another +so the effect of the transient + + align:start position:0% +so the effect of the transient + + + align:start position:0% +so the effect of the transient +correction as you can see here is + + align:start position:0% +correction as you can see here is + + + align:start position:0% +correction as you can see here is +when when lambda c tau is + + align:start position:0% +when when lambda c tau is + + + align:start position:0% +when when lambda c tau is +larger than one so that's times that are + + align:start position:0% +larger than one so that's times that are + + + align:start position:0% +larger than one so that's times that are +kind of out here that term is gone + + align:start position:0% +kind of out here that term is gone + + + align:start position:0% +kind of out here that term is gone +but when you get to these earlier times + + align:start position:0% +but when you get to these earlier times + + + align:start position:0% +but when you get to these earlier times +or very short times where there hasn't + + align:start position:0% +or very short times where there hasn't + + + align:start position:0% +or very short times where there hasn't +been time yet for the build up + + align:start position:0% +been time yet for the build up + + + align:start position:0% +been time yet for the build up +of the airborne concentration + + align:start position:0% +of the airborne concentration + + + align:start position:0% +of the airborne concentration +then as you see as tau goes to zero + + align:start position:0% +then as you see as tau goes to zero + + + align:start position:0% +then as you see as tau goes to zero +actually this term diverges + + align:start position:0% +actually this term diverges + + + align:start position:0% +actually this term diverges +so what actually happens is that if i + + align:start position:0% +so what actually happens is that if i + + + align:start position:0% +so what actually happens is that if i +calculate sort of you know + + align:start position:0% +calculate sort of you know + + + align:start position:0% +calculate sort of you know +for example what they get from this + + align:start position:0% +for example what they get from this + + + align:start position:0% +for example what they get from this +guideline is + + align:start position:0% +guideline is + + + align:start position:0% +guideline is +what is the uh + + align:start position:0% +what is the uh + + + align:start position:0% +what is the uh +sort of sort of maximum occupancy + + align:start position:0% +sort of sort of maximum occupancy + + + align:start position:0% +sort of sort of maximum occupancy +or versus time or it's sort of the + + align:start position:0% +or versus time or it's sort of the + + + align:start position:0% +or versus time or it's sort of the +maximum time in the room for a given + + align:start position:0% +maximum time in the room for a given + + + align:start position:0% +maximum time in the room for a given +occupancy we're going to be looking at + + align:start position:0% +occupancy we're going to be looking at + + + align:start position:0% +occupancy we're going to be looking at +lots of plots like this + + align:start position:0% +lots of plots like this + + + align:start position:0% +lots of plots like this +um i would have something that might + + align:start position:0% +um i would have something that might + + + align:start position:0% +um i would have something that might +look + + align:start position:0% +look + + + align:start position:0% +look +like this for steady transmission + + align:start position:0% +like this for steady transmission + + + align:start position:0% +like this for steady transmission +okay and when this time + + align:start position:0% +okay and when this time + + + align:start position:0% +okay and when this time +gets larger than + + align:start position:0% +gets larger than + + + align:start position:0% +gets larger than +lambda c of r bar inverse + + align:start position:0% +lambda c of r bar inverse + + + align:start position:0% +lambda c of r bar inverse +okay there's some critical time scale + + align:start position:0% +okay there's some critical time scale + + + align:start position:0% +okay there's some critical time scale +there which is this one right here + + align:start position:0% +there which is this one right here + + + align:start position:0% +there which is this one right here +then when you're past that time so + + align:start position:0% +then when you're past that time so + + + align:start position:0% +then when you're past that time so +you've got the steady state but if you + + align:start position:0% +you've got the steady state but if you + + + align:start position:0% +you've got the steady state but if you +go to smaller times + + align:start position:0% +go to smaller times + + + align:start position:0% +go to smaller times +then what happens that this thing can + + align:start position:0% +then what happens that this thing can + + + align:start position:0% +then what happens that this thing can +sort of blow up a lot + + align:start position:0% +sort of blow up a lot + + + align:start position:0% +sort of blow up a lot +faster so so what it kind of + + align:start position:0% +faster so so what it kind of + + + align:start position:0% +faster so so what it kind of +helps to capture is again this intuition + + align:start position:0% +helps to capture is again this intuition + + + align:start position:0% +helps to capture is again this intuition +that if i put in like tau is + + align:start position:0% +that if i put in like tau is + + + align:start position:0% +that if i put in like tau is +you know extremely small then of course + + align:start position:0% +you know extremely small then of course + + + align:start position:0% +you know extremely small then of course +the risk goes away and i can have larger + + align:start position:0% +the risk goes away and i can have larger + + + align:start position:0% +the risk goes away and i can have larger +numbers of people in the room or i can + + align:start position:0% +numbers of people in the room or i can + + + align:start position:0% +numbers of people in the room or i can +tolerate smaller times and actually be + + align:start position:0% +tolerate smaller times and actually be + + + align:start position:0% +tolerate smaller times and actually be +safe + + align:start position:0% +safe + + + align:start position:0% +safe +so anyway that's one reason + + align:start position:0% +so anyway that's one reason + + + align:start position:0% +so anyway that's one reason +we do that on the other hand for a + + align:start position:0% +we do that on the other hand for a + + + align:start position:0% +we do that on the other hand for a +conservative guideline and the most + + align:start position:0% +conservative guideline and the most + + + align:start position:0% +conservative guideline and the most +important message of this course + + align:start position:0% +important message of this course + + + align:start position:0% +important message of this course +really is to think about that steady + + align:start position:0% +really is to think about that steady + + + align:start position:0% +really is to think about that steady +state transmission rate which we will + + align:start position:0% +state transmission rate which we will + + + align:start position:0% +state transmission rate which we will +mainly be focusing on in all of our + + align:start position:0% + + + + align:start position:0% + +examples \ No newline at end of file diff --git a/_qTVDxXBK5A.txt b/_qTVDxXBK5A.txt new file mode 100644 index 0000000000000000000000000000000000000000..df2c4c12b920d3258dd4abb87c4fcf92684e56a0 --- /dev/null +++ b/_qTVDxXBK5A.txt @@ -0,0 +1,635 @@ +align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +I'm Nick chinii I'm finishing my PhD in + + align:start position:0% +I'm Nick chinii I'm finishing my PhD in + + + align:start position:0% +I'm Nick chinii I'm finishing my PhD in +computational biology at Cornell + + align:start position:0% +computational biology at Cornell + + + align:start position:0% +computational biology at Cornell +University Gabriel criman and I are + + align:start position:0% +University Gabriel criman and I are + + + align:start position:0% +University Gabriel criman and I are +interested in seeing how deep networks + + align:start position:0% +interested in seeing how deep networks + + + align:start position:0% +interested in seeing how deep networks +respond to neuroplasticity so in the + + align:start position:0% +respond to neuroplasticity so in the + + + align:start position:0% +respond to neuroplasticity so in the +brain we know that the brain's + + align:start position:0% +brain we know that the brain's + + + align:start position:0% +brain we know that the brain's +constantly in flux and neurons are + + align:start position:0% +constantly in flux and neurons are + + + align:start position:0% +constantly in flux and neurons are +growing and dying weights are changing + + align:start position:0% +growing and dying weights are changing + + + align:start position:0% +growing and dying weights are changing +in response to stimuli but most of the + + align:start position:0% +in response to stimuli but most of the + + + align:start position:0% +in response to stimuli but most of the +time in machine learning what we do is + + align:start position:0% +time in machine learning what we do is + + + align:start position:0% +time in machine learning what we do is +pre-train a network on some training set + + align:start position:0% +pre-train a network on some training set + + + align:start position:0% +pre-train a network on some training set +but then we want to use it for real we + + align:start position:0% +but then we want to use it for real we + + + align:start position:0% +but then we want to use it for real we +freeze it um and keep it in some static + + align:start position:0% +freeze it um and keep it in some static + + + align:start position:0% +freeze it um and keep it in some static +form there's been a lot more emphasis + + align:start position:0% +form there's been a lot more emphasis + + + align:start position:0% +form there's been a lot more emphasis +lately on more online learning so that + + align:start position:0% +lately on more online learning so that + + + align:start position:0% +lately on more online learning so that +you learn as you're working on a data + + align:start position:0% +you learn as you're working on a data + + + align:start position:0% +you learn as you're working on a data +set and in those kind of environments we + + align:start position:0% +set and in those kind of environments we + + + align:start position:0% +set and in those kind of environments we +think that the network will be changing + + align:start position:0% +think that the network will be changing + + + align:start position:0% +think that the network will be changing +quite a bit so we're looking at how uh + + align:start position:0% +quite a bit so we're looking at how uh + + + align:start position:0% +quite a bit so we're looking at how uh +that Network could be robust to those + + align:start position:0% +that Network could be robust to those + + + align:start position:0% +that Network could be robust to those +kind of changes uh much like the bra is + + align:start position:0% +kind of changes uh much like the bra is + + + align:start position:0% +kind of changes uh much like the bra is +to Everyday stimuli and actions and sees + + align:start position:0% +to Everyday stimuli and actions and sees + + + align:start position:0% +to Everyday stimuli and actions and sees +to start out um just doing a a very + + align:start position:0% +to start out um just doing a a very + + + align:start position:0% +to start out um just doing a a very +simple test uh looking at perturbations + + align:start position:0% +simple test uh looking at perturbations + + + align:start position:0% +simple test uh looking at perturbations +of the network so just throwing random + + align:start position:0% +of the network so just throwing random + + + align:start position:0% +of the network so just throwing random +changes at the weights uh that make up + + align:start position:0% +changes at the weights uh that make up + + + align:start position:0% +changes at the weights uh that make up +this network um and seeing how that + + align:start position:0% +this network um and seeing how that + + + align:start position:0% +this network um and seeing how that +affects its ability to classify images + + align:start position:0% +affects its ability to classify images + + + align:start position:0% +affects its ability to classify images +after that we're looking at how + + align:start position:0% +after that we're looking at how + + + align:start position:0% +after that we're looking at how +different parts of the network respond + + align:start position:0% +different parts of the network respond + + + align:start position:0% +different parts of the network respond +differently to these kind of changes and + + align:start position:0% +differently to these kind of changes and + + + align:start position:0% +differently to these kind of changes and +then ideally we'd like to have some kind + + align:start position:0% +then ideally we'd like to have some kind + + + align:start position:0% +then ideally we'd like to have some kind +of rule that uh doesn't affect the + + align:start position:0% +of rule that uh doesn't affect the + + + align:start position:0% +of rule that uh doesn't affect the +performance of the network that much and + + align:start position:0% +performance of the network that much and + + + align:start position:0% +performance of the network that much and +it's able to maintain its ability to + + align:start position:0% +it's able to maintain its ability to + + + align:start position:0% +it's able to maintain its ability to +classify throughout seeing a number of + + align:start position:0% +classify throughout seeing a number of + + + align:start position:0% +classify throughout seeing a number of +stimuli so we know that the brain has + + align:start position:0% +stimuli so we know that the brain has + + + align:start position:0% +stimuli so we know that the brain has +certain learning rules like tb's rule um + + align:start position:0% +certain learning rules like tb's rule um + + + align:start position:0% +certain learning rules like tb's rule um +in which neurons that fire one after + + align:start position:0% +in which neurons that fire one after + + + align:start position:0% +in which neurons that fire one after +another end up strengthening their + + align:start position:0% +another end up strengthening their + + + align:start position:0% +another end up strengthening their +connections or uh conversely weakening + + align:start position:0% +connections or uh conversely weakening + + + align:start position:0% +connections or uh conversely weakening +their reactions and we're see going to + + align:start position:0% +their reactions and we're see going to + + + align:start position:0% +their reactions and we're see going to +see if rules like that uh end up + + align:start position:0% +see if rules like that uh end up + + + align:start position:0% +see if rules like that uh end up +providing stable perturbations where the + + align:start position:0% +providing stable perturbations where the + + + align:start position:0% +providing stable perturbations where the +network can easily recover um and + + align:start position:0% +network can easily recover um and + + + align:start position:0% +network can easily recover um and +maintain what it's doing or unstable + + align:start position:0% +maintain what it's doing or unstable + + + align:start position:0% +maintain what it's doing or unstable +ones where we're going to go down on + + align:start position:0% +ones where we're going to go down on + + + align:start position:0% +ones where we're going to go down on +track or we know that deep networks act + + align:start position:0% +track or we know that deep networks act + + + align:start position:0% +track or we know that deep networks act +uh similar to how the brain works uh Jim + + align:start position:0% +uh similar to how the brain works uh Jim + + + align:start position:0% +uh similar to how the brain works uh Jim +D Carlo came great gave a great talk + + align:start position:0% +D Carlo came great gave a great talk + + + align:start position:0% +D Carlo came great gave a great talk +about um how the features we see in deep + + align:start position:0% +about um how the features we see in deep + + + align:start position:0% +about um how the features we see in deep +networks are similar to the features in + + align:start position:0% +networks are similar to the features in + + + align:start position:0% +networks are similar to the features in +the brain we know that the brain's + + align:start position:0% +the brain we know that the brain's + + + align:start position:0% +the brain we know that the brain's +constantly undergoing these kind of + + align:start position:0% +constantly undergoing these kind of + + + align:start position:0% +constantly undergoing these kind of +changes so uh it's we're curious + + align:start position:0% +changes so uh it's we're curious + + + align:start position:0% +changes so uh it's we're curious +scientifically to see how these computer + + align:start position:0% +scientifically to see how these computer + + + align:start position:0% +scientifically to see how these computer +models respond um in understanding how + + align:start position:0% +models respond um in understanding how + + + align:start position:0% +models respond um in understanding how +these two systems are the same or + + align:start position:0% +these two systems are the same or + + + align:start position:0% +these two systems are the same or +different uh but also from an + + align:start position:0% +different uh but also from an + + + align:start position:0% +different uh but also from an +engineering context uh online learning + + align:start position:0% +engineering context uh online learning + + + align:start position:0% +engineering context uh online learning +where the network is changing uh while + + align:start position:0% +where the network is changing uh while + + + align:start position:0% +where the network is changing uh while +it's learning is going to be I think a + + align:start position:0% +it's learning is going to be I think a + + + align:start position:0% +it's learning is going to be I think a +much larger part of the use of machine + + align:start position:0% +much larger part of the use of machine + + + align:start position:0% +much larger part of the use of machine +learning going forward so understanding + + align:start position:0% +learning going forward so understanding + + + align:start position:0% +learning going forward so understanding +how stable these things are uh to + + align:start position:0% +how stable these things are uh to + + + align:start position:0% +how stable these things are uh to +constantly changing parameters I think + + align:start position:0% +constantly changing parameters I think + + + align:start position:0% +constantly changing parameters I think +will be quite informative for those kind + + align:start position:0% +will be quite informative for those kind + + + align:start position:0% +will be quite informative for those kind +of studies being able to + + align:start position:0% +of studies being able to + + + align:start position:0% +of studies being able to +explore uh new types of M materials and + + align:start position:0% +explore uh new types of M materials and + + + align:start position:0% +explore uh new types of M materials and +uh learn a lot about both computer + + align:start position:0% +uh learn a lot about both computer + + + align:start position:0% +uh learn a lot about both computer +vision and Neuroscience has been a lot + + align:start position:0% +vision and Neuroscience has been a lot + + + align:start position:0% +vision and Neuroscience has been a lot +of fun um and certainly informative deep + + align:start position:0% +of fun um and certainly informative deep + + + align:start position:0% +of fun um and certainly informative deep +learning is is a very hot topic right + + align:start position:0% +learning is is a very hot topic right + + + align:start position:0% +learning is is a very hot topic right +now so being able to dive hands in a + + align:start position:0% +now so being able to dive hands in a + + + align:start position:0% +now so being able to dive hands in a +little bit um and get some experience + + align:start position:0% +little bit um and get some experience + + + align:start position:0% +little bit um and get some experience +working with these models and some of + + align:start position:0% +working with these models and some of + + + align:start position:0% +working with these models and some of +the the latest uh software packages I + + align:start position:0% +the the latest uh software packages I + + + align:start position:0% +the the latest uh software packages I +think will be useful going forwards too + + align:start position:0% + + + + align:start position:0% + +[Music] \ No newline at end of file diff --git a/bAkuNXtgrLA.txt b/bAkuNXtgrLA.txt new file mode 100644 index 0000000000000000000000000000000000000000..5598e2f7413d14cd914c2fa5d24ee68f94a37378 --- /dev/null +++ b/bAkuNXtgrLA.txt @@ -0,0 +1,11619 @@ +align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +seeing where animals are going so you + + align:start position:0% +seeing where animals are going so you + + + align:start position:0% +seeing where animals are going so you +can avoid them if they're coming after + + align:start position:0% +can avoid them if they're coming after + + + align:start position:0% +can avoid them if they're coming after +you or if you can catch them if you're + + align:start position:0% +you or if you can catch them if you're + + + align:start position:0% +you or if you can catch them if you're +going after them right one of the + + align:start position:0% +going after them right one of the + + + align:start position:0% +going after them right one of the +arguably + + align:start position:0% +arguably + + + align:start position:0% +arguably +uniquely human abilities is precision + + align:start position:0% +uniquely human abilities is precision + + + align:start position:0% +uniquely human abilities is precision +throwing right no other animal can do + + align:start position:0% +throwing right no other animal can do + + + align:start position:0% +throwing right no other animal can do +that that's a very human thing + + align:start position:0% +that that's a very human thing + + + align:start position:0% +that that's a very human thing +although visual motion is shared with + + align:start position:0% +although visual motion is shared with + + + align:start position:0% +although visual motion is shared with +lots of ability to see motion is shared + + align:start position:0% +lots of ability to see motion is shared + + + align:start position:0% +lots of ability to see motion is shared +with lots of animals what else did you + + align:start position:0% +with lots of animals what else did you + + + align:start position:0% +with lots of animals what else did you +notice + + align:start position:0% +notice + + + align:start position:0% +notice +what else seemed funny or or + + align:start position:0% +what else seemed funny or or + + + align:start position:0% +what else seemed funny or or +you know harder to discern with stop + + align:start position:0% +you know harder to discern with stop + + + align:start position:0% +you know harder to discern with stop +motion yeah + + align:start position:0% +motion yeah + + + align:start position:0% +motion yeah +we care about small details like the + + align:start position:0% +we care about small details like the + + + align:start position:0% +we care about small details like the +movement to + + align:start position:0% +movement to + + + align:start position:0% +movement to +understand what your person is saying + + align:start position:0% +understand what your person is saying + + + align:start position:0% +understand what your person is saying +yeah yeah so + + align:start position:0% +yeah yeah so + + + align:start position:0% +yeah yeah so +um + + align:start position:0% +um + + + align:start position:0% +um +i was making notes to self i haven't + + align:start position:0% +i was making notes to self i haven't + + + align:start position:0% +i was making notes to self i haven't +done that demo before but in future it + + align:start position:0% +done that demo before but in future it + + + align:start position:0% +done that demo before but in future it +would be really good to have the audio + + align:start position:0% +would be really good to have the audio + + + align:start position:0% +would be really good to have the audio +quality terrible because if the audio + + align:start position:0% +quality terrible because if the audio + + + align:start position:0% +quality terrible because if the audio +quality is terrible you would lean more + + align:start position:0% +quality is terrible you would lean more + + + align:start position:0% +quality is terrible you would lean more +on lip reading and we might have noticed + + align:start position:0% +on lip reading and we might have noticed + + + align:start position:0% +on lip reading and we might have noticed +more that it's really hard to do that + + align:start position:0% +more that it's really hard to do that + + + align:start position:0% +more that it's really hard to do that +probably even at relatively fast flicker + + align:start position:0% +probably even at relatively fast flicker + + + align:start position:0% +probably even at relatively fast flicker +rates because that motion information is + + align:start position:0% +rates because that motion information is + + + align:start position:0% +rates because that motion information is +important absolutely what else + + align:start position:0% + + + + align:start position:0% + +how about beyond just lip reading what + + align:start position:0% +how about beyond just lip reading what + + + align:start position:0% +how about beyond just lip reading what +else did you notice about the faces mine + + align:start position:0% +else did you notice about the faces mine + + + align:start position:0% +else did you notice about the faces mine +or gems + + align:start position:0% + + + + align:start position:0% + +could you yeah they were static so it + + align:start position:0% +could you yeah they were static so it + + + align:start position:0% +could you yeah they were static so it +was kind of hard to tell like emotion + + align:start position:0% +was kind of hard to tell like emotion + + + align:start position:0% +was kind of hard to tell like emotion +because like a lot of our um the ways we + + align:start position:0% +because like a lot of our um the ways we + + + align:start position:0% +because like a lot of our um the ways we +express emotion is very nuanced exactly + + align:start position:0% +express emotion is very nuanced exactly + + + align:start position:0% +express emotion is very nuanced exactly +exactly facial expressions are + + align:start position:0% +exactly facial expressions are + + + align:start position:0% +exactly facial expressions are +incredibly subtle like little micro + + align:start position:0% +incredibly subtle like little micro + + + align:start position:0% +incredibly subtle like little micro +expressions flicker across the face in a + + align:start position:0% +expressions flicker across the face in a + + + align:start position:0% +expressions flicker across the face in a +tenth of a second and go away and you + + align:start position:0% +tenth of a second and go away and you + + + align:start position:0% +tenth of a second and go away and you +guys detect them like we're we're very + + align:start position:0% +guys detect them like we're we're very + + + align:start position:0% +guys detect them like we're we're very +very sensitive to those things you know + + align:start position:0% +very sensitive to those things you know + + + align:start position:0% +very sensitive to those things you know +if somebody you know sometimes if you + + align:start position:0% +if somebody you know sometimes if you + + + align:start position:0% +if somebody you know sometimes if you +see somebody in a hallway and + + align:start position:0% +see somebody in a hallway and + + + align:start position:0% +see somebody in a hallway and +for a moment there's an expression that + + align:start position:0% +for a moment there's an expression that + + + align:start position:0% +for a moment there's an expression that +flickers across their face and then they + + align:start position:0% +flickers across their face and then they + + + align:start position:0% +flickers across their face and then they +give you like a normal smile but you can + + align:start position:0% +give you like a normal smile but you can + + + align:start position:0% +give you like a normal smile but you can +tell from that expression that actually + + align:start position:0% +tell from that expression that actually + + + align:start position:0% +tell from that expression that actually +they didn't want to see you for whatever + + align:start position:0% +they didn't want to see you for whatever + + + align:start position:0% +they didn't want to see you for whatever +reason right we catch those things we're + + align:start position:0% +reason right we catch those things we're + + + align:start position:0% +reason right we catch those things we're +really really good at catching those + + align:start position:0% +really really good at catching those + + + align:start position:0% +really really good at catching those +little fleeting expressions and those + + align:start position:0% +little fleeting expressions and those + + + align:start position:0% +little fleeting expressions and those +probably have to do with not just + + align:start position:0% +probably have to do with not just + + + align:start position:0% +probably have to do with not just +sampling with fine temporal frequency + + align:start position:0% +sampling with fine temporal frequency + + + align:start position:0% +sampling with fine temporal frequency +but probably seeing the direction of + + align:start position:0% +but probably seeing the direction of + + + align:start position:0% +but probably seeing the direction of +motion of each little part of the face + + align:start position:0% +motion of each little part of the face + + + align:start position:0% +motion of each little part of the face +okay + + align:start position:0% +okay + + + align:start position:0% +okay +okay so this is just common sense + + align:start position:0% +okay so this is just common sense + + + align:start position:0% +okay so this is just common sense +reasoning about what we might have + + align:start position:0% +reasoning about what we might have + + + align:start position:0% +reasoning about what we might have +motion for okay and so you guys got all + + align:start position:0% +motion for okay and so you guys got all + + + align:start position:0% +motion for okay and so you guys got all +the things that i had in mind okay so + + align:start position:0% +the things that i had in mind okay so + + + align:start position:0% +the things that i had in mind okay so +now next question just kind of thought a + + align:start position:0% +now next question just kind of thought a + + + align:start position:0% +now next question just kind of thought a +thought question speculation question + + align:start position:0% +thought question speculation question + + + align:start position:0% +thought question speculation question +given the these many different things + + align:start position:0% +given the these many different things + + + align:start position:0% +given the these many different things +that make motion important to us uh + + align:start position:0% +that make motion important to us uh + + + align:start position:0% +that make motion important to us uh +biologically ecologically in our daily + + align:start position:0% +biologically ecologically in our daily + + + align:start position:0% +biologically ecologically in our daily +lives + + align:start position:0% +lives + + + align:start position:0% +lives +maybe that's important enough that we + + align:start position:0% +maybe that's important enough that we + + + align:start position:0% +maybe that's important enough that we +might allocate special brain machinery + + align:start position:0% +might allocate special brain machinery + + + align:start position:0% +might allocate special brain machinery +to processing motion + + align:start position:0% +to processing motion + + + align:start position:0% +to processing motion +what do you think + + align:start position:0% +what do you think + + + align:start position:0% +what do you think +important enough could you get by if you + + align:start position:0% +important enough could you get by if you + + + align:start position:0% +important enough could you get by if you +lived in a strobe world all the time + + align:start position:0% +lived in a strobe world all the time + + + align:start position:0% +lived in a strobe world all the time +could you survive just fine + + align:start position:0% + + + + align:start position:0% + +hard to say right might be hard i mean + + align:start position:0% +hard to say right might be hard i mean + + + align:start position:0% +hard to say right might be hard i mean +we probably don't need to go hunting + + align:start position:0% +we probably don't need to go hunting + + + align:start position:0% +we probably don't need to go hunting +down predators but um you know you walk + + align:start position:0% +down predators but um you know you walk + + + align:start position:0% +down predators but um you know you walk +across vassar street and there's some + + align:start position:0% +across vassar street and there's some + + + align:start position:0% +across vassar street and there's some +pretty dangerous predators coming down + + align:start position:0% +pretty dangerous predators coming down + + + align:start position:0% +pretty dangerous predators coming down +vassar street in the way of cars right + + align:start position:0% +vassar street in the way of cars right + + + align:start position:0% +vassar street in the way of cars right +you need to know where they're going and + + align:start position:0% +you need to know where they're going and + + + align:start position:0% +you need to know where they're going and +whether you can cross in front of them + + align:start position:0% +whether you can cross in front of them + + + align:start position:0% +whether you can cross in front of them +so it's actually pretty hard + + align:start position:0% +so it's actually pretty hard + + + align:start position:0% +so it's actually pretty hard +to live life without being able to see + + align:start position:0% +to live life without being able to see + + + align:start position:0% +to live life without being able to see +motion and i'll tell you about a woman + + align:start position:0% +motion and i'll tell you about a woman + + + align:start position:0% +motion and i'll tell you about a woman +who has that experience later in the + + align:start position:0% +who has that experience later in the + + + align:start position:0% +who has that experience later in the +lecture + + align:start position:0% +lecture + + + align:start position:0% +lecture +okay + + align:start position:0% +okay + + + align:start position:0% +okay +next question + + align:start position:0% +next question + + + align:start position:0% +next question +just think about this i'm not going to + + align:start position:0% +just think about this i'm not going to + + + align:start position:0% +just think about this i'm not going to +test you on it or anything it's not the + + align:start position:0% +test you on it or anything it's not the + + + align:start position:0% +test you on it or anything it's not the +topic of this course but it's a + + align:start position:0% +topic of this course but it's a + + + align:start position:0% +topic of this course but it's a +perspective you should take imagine + + align:start position:0% +perspective you should take imagine + + + align:start position:0% +perspective you should take imagine +that this were a cs course and i gave + + align:start position:0% +that this were a cs course and i gave + + + align:start position:0% +that this were a cs course and i gave +you a segment of video + + align:start position:0% +you a segment of video + + + align:start position:0% +you a segment of video +and your task was to take some to write + + align:start position:0% +and your task was to take some to write + + + align:start position:0% +and your task was to take some to write +some code that takes that video input + + align:start position:0% +some code that takes that video input + + + align:start position:0% +some code that takes that video input +and says whether objects are moving in + + align:start position:0% +and says whether objects are moving in + + + align:start position:0% +and says whether objects are moving in +that movie or says which objects are + + align:start position:0% +that movie or says which objects are + + + align:start position:0% +that movie or says which objects are +moving or how much they're moving or + + align:start position:0% +moving or how much they're moving or + + + align:start position:0% +moving or how much they're moving or +what direction they're moving what kind + + align:start position:0% +what direction they're moving what kind + + + align:start position:0% +what direction they're moving what kind +of code would you have to write to take + + align:start position:0% +of code would you have to write to take + + + align:start position:0% +of code would you have to write to take +that video input to try to figure that + + align:start position:0% +that video input to try to figure that + + + align:start position:0% +that video input to try to figure that +out + + align:start position:0% +out + + + align:start position:0% +out +okay so just think about that we're not + + align:start position:0% +okay so just think about that we're not + + + align:start position:0% +okay so just think about that we're not +going to be writing code in this class + + align:start position:0% +going to be writing code in this class + + + align:start position:0% +going to be writing code in this class +but a lot of what we're going to be + + align:start position:0% +but a lot of what we're going to be + + + align:start position:0% +but a lot of what we're going to be +doing is thinking about + + align:start position:0% +doing is thinking about + + + align:start position:0% +doing is thinking about +how do you + + align:start position:0% +how do you + + + align:start position:0% +how do you +take this kind of perceptual input and + + align:start position:0% +take this kind of perceptual input and + + + align:start position:0% +take this kind of perceptual input and +come out with that kind of perceptual + + align:start position:0% +come out with that kind of perceptual + + + align:start position:0% +come out with that kind of perceptual +inference + + align:start position:0% +inference + + + align:start position:0% +inference +and what kinds of computations would + + align:start position:0% +and what kinds of computations would + + + align:start position:0% +and what kinds of computations would +have to go on in between + + align:start position:0% +have to go on in between + + + align:start position:0% +have to go on in between +whether those computations are going on + + align:start position:0% +whether those computations are going on + + + align:start position:0% +whether those computations are going on +in code that you guys write or in a + + align:start position:0% +in code that you guys write or in a + + + align:start position:0% +in code that you guys write or in a +piece of brain that's doing that + + align:start position:0% +piece of brain that's doing that + + + align:start position:0% +piece of brain that's doing that +computation + + align:start position:0% +computation + + + align:start position:0% +computation +and thinking about how you might might + + align:start position:0% +and thinking about how you might might + + + align:start position:0% +and thinking about how you might might +write the code gives you really + + align:start position:0% +write the code gives you really + + + align:start position:0% +write the code gives you really +important insights about what the brain + + align:start position:0% +important insights about what the brain + + + align:start position:0% +important insights about what the brain +might be doing okay + + align:start position:0% +might be doing okay + + + align:start position:0% +might be doing okay +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so that's the point of all of that the + + align:start position:0% +so that's the point of all of that the + + + align:start position:0% +so that's the point of all of that the +the mar reading talks about all of this + + align:start position:0% +the mar reading talks about all of this + + + align:start position:0% +the mar reading talks about all of this +and the key point we're trying to get + + align:start position:0% +and the key point we're trying to get + + + align:start position:0% +and the key point we're trying to get +here is that you can't understand + + align:start position:0% +here is that you can't understand + + + align:start position:0% +here is that you can't understand +perception + + align:start position:0% +perception + + + align:start position:0% +perception +without thinking about what each + + align:start position:0% +without thinking about what each + + + align:start position:0% +without thinking about what each +perceptual inference is necessary for + + align:start position:0% +perceptual inference is necessary for + + + align:start position:0% +perceptual inference is necessary for +ecologically in daily lives + + align:start position:0% +ecologically in daily lives + + + align:start position:0% +ecologically in daily lives +and about the computational challenges + + align:start position:0% +and about the computational challenges + + + align:start position:0% +and about the computational challenges +involved in making that inference okay + + align:start position:0% +involved in making that inference okay + + + align:start position:0% +involved in making that inference okay +so we'll get back to all that + + align:start position:0% +so we'll get back to all that + + + align:start position:0% +so we'll get back to all that +but + + align:start position:0% +but + + + align:start position:0% +but +next week and beyond but meanwhile + + align:start position:0% +next week and beyond but meanwhile + + + align:start position:0% +next week and beyond but meanwhile +here's the agenda for today so here's + + align:start position:0% +here's the agenda for today so here's + + + align:start position:0% +here's the agenda for today so here's +the agenda we just did the demo we're + + align:start position:0% +the agenda we just did the demo we're + + + align:start position:0% +the agenda we just did the demo we're +now going to skip and do some + + align:start position:0% +now going to skip and do some + + + align:start position:0% +now going to skip and do some +neuroanatomy absolutely bear basics + + align:start position:0% +neuroanatomy absolutely bear basics + + + align:start position:0% +neuroanatomy absolutely bear basics +because on wednesday we have this + + align:start position:0% +because on wednesday we have this + + + align:start position:0% +because on wednesday we have this +amazing opportunity to have one of the + + align:start position:0% +amazing opportunity to have one of the + + + align:start position:0% +amazing opportunity to have one of the +most kind of famous neuroscientists in + + align:start position:0% +most kind of famous neuroscientists in + + + align:start position:0% +most kind of famous neuroscientists in +the world do a dissection of a real + + align:start position:0% +the world do a dissection of a real + + + align:start position:0% +the world do a dissection of a real +human brain right here right in front of + + align:start position:0% +human brain right here right in front of + + + align:start position:0% +human brain right here right in front of +you it's going to be awesome + + align:start position:0% +you it's going to be awesome + + + align:start position:0% +you it's going to be awesome +and i don't want to + + align:start position:0% +and i don't want to + + + align:start position:0% +and i don't want to +waste that opportunity + + align:start position:0% +waste that opportunity + + + align:start position:0% +waste that opportunity +or + + align:start position:0% +or + + + align:start position:0% +or +embarrass ourselves by having people not + + align:start position:0% +embarrass ourselves by having people not + + + align:start position:0% +embarrass ourselves by having people not +know the bare basics so we're going to + + align:start position:0% +know the bare basics so we're going to + + + align:start position:0% +know the bare basics so we're going to +do the bare basics it's all stuff you + + align:start position:0% +do the bare basics it's all stuff you + + + align:start position:0% +do the bare basics it's all stuff you +should know from 900 and 901 and i'm + + align:start position:0% +should know from 900 and 901 and i'm + + + align:start position:0% +should know from 900 and 901 and i'm +going to whip through it fast so we can + + align:start position:0% +going to whip through it fast so we can + + + align:start position:0% +going to whip through it fast so we can +get to more interesting stuff and get + + align:start position:0% +get to more interesting stuff and get + + + align:start position:0% +get to more interesting stuff and get +back to visual motion okay + + align:start position:0% +back to visual motion okay + + + align:start position:0% +back to visual motion okay +that's the agenda + + align:start position:0% +that's the agenda + + + align:start position:0% +that's the agenda +all right so some absolute bare basics + + align:start position:0% +all right so some absolute bare basics + + + align:start position:0% +all right so some absolute bare basics +of the brain + + align:start position:0% +of the brain + + + align:start position:0% +of the brain +the human brain contains about 100 + + align:start position:0% +the human brain contains about 100 + + + align:start position:0% +the human brain contains about 100 +billion 10 to the 11th neurons and + + align:start position:0% +billion 10 to the 11th neurons and + + + align:start position:0% +billion 10 to the 11th neurons and +that's a very big number that's such a + + align:start position:0% +that's a very big number that's such a + + + align:start position:0% +that's a very big number that's such a +big number it's approximately jeff bezos + + align:start position:0% +big number it's approximately jeff bezos + + + align:start position:0% +big number it's approximately jeff bezos +is worth well it was until mackenzie got + + align:start position:0% +is worth well it was until mackenzie got + + + align:start position:0% +is worth well it was until mackenzie got +into the picture so we'll see + + align:start position:0% +into the picture so we'll see + + + align:start position:0% +into the picture so we'll see +no you don't need to remember this + + align:start position:0% +no you don't need to remember this + + + align:start position:0% +no you don't need to remember this +number just know it's a really big + + align:start position:0% +number just know it's a really big + + + align:start position:0% +number just know it's a really big +number + + align:start position:0% +number + + + align:start position:0% +number +basics of a neuron here's a neuron a + + align:start position:0% +basics of a neuron here's a neuron a + + + align:start position:0% +basics of a neuron here's a neuron a +neuron is a cell like any other cell in + + align:start position:0% +neuron is a cell like any other cell in + + + align:start position:0% +neuron is a cell like any other cell in +the body it's got a cell body and a + + align:start position:0% +the body it's got a cell body and a + + + align:start position:0% +the body it's got a cell body and a +nucleus just like any other cell in your + + align:start position:0% +nucleus just like any other cell in your + + + align:start position:0% +nucleus just like any other cell in your +body but the thing that's distinctive + + align:start position:0% +body but the thing that's distinctive + + + align:start position:0% +body but the thing that's distinctive +about a neuron is has a big long process + + align:start position:0% +about a neuron is has a big long process + + + align:start position:0% +about a neuron is has a big long process +called an axon it's got a bunch of + + align:start position:0% +called an axon it's got a bunch of + + + align:start position:0% +called an axon it's got a bunch of +dendrites the little processes little + + align:start position:0% +dendrites the little processes little + + + align:start position:0% +dendrites the little processes little +thingies + + align:start position:0% +thingies + + + align:start position:0% +thingies +near the cell body and out at the tip of + + align:start position:0% +near the cell body and out at the tip of + + + align:start position:0% +near the cell body and out at the tip of +the axon + + align:start position:0% +the axon + + + align:start position:0% +the axon +that's your classic neuron many neurons + + align:start position:0% +that's your classic neuron many neurons + + + align:start position:0% +that's your classic neuron many neurons +have a myelin sheath a layer of rolled + + align:start position:0% +have a myelin sheath a layer of rolled + + + align:start position:0% +have a myelin sheath a layer of rolled +up fat around the axon + + align:start position:0% +up fat around the axon + + + align:start position:0% +up fat around the axon +made up of other cells that makes axon + + align:start position:0% +made up of other cells that makes axon + + + align:start position:0% +made up of other cells that makes axon +conduct neural signals faster okay you + + align:start position:0% +conduct neural signals faster okay you + + + align:start position:0% +conduct neural signals faster okay you +should know all that i'm not trying to + + align:start position:0% +should know all that i'm not trying to + + + align:start position:0% +should know all that i'm not trying to +insult your intelligence i'm just trying + + align:start position:0% +insult your intelligence i'm just trying + + + align:start position:0% +insult your intelligence i'm just trying +to make sure everybody's with the + + align:start position:0% +to make sure everybody's with the + + + align:start position:0% +to make sure everybody's with the +program here okay so you have thousands + + align:start position:0% +program here okay so you have thousands + + + align:start position:0% +program here okay so you have thousands +of synapses on each neuron and that + + align:start position:0% +of synapses on each neuron and that + + + align:start position:0% +of synapses on each neuron and that +means you have to put a technically a + + align:start position:0% +means you have to put a technically a + + + align:start position:0% +means you have to put a technically a +shitload of synapses in your brain okay + + align:start position:0% +shitload of synapses in your brain okay + + + align:start position:0% +shitload of synapses in your brain okay +another important point um the brain + + align:start position:0% +another important point um the brain + + + align:start position:0% +another important point um the brain +runs on a mere 20 watts and if you're + + align:start position:0% +runs on a mere 20 watts and if you're + + + align:start position:0% +runs on a mere 20 watts and if you're +not impressed with that + + align:start position:0% +not impressed with that + + + align:start position:0% +not impressed with that +reflect on the fact that ibm's watson + + align:start position:0% +reflect on the fact that ibm's watson + + + align:start position:0% +reflect on the fact that ibm's watson +runs on 20 000 watts so one of the cool + + align:start position:0% +runs on 20 000 watts so one of the cool + + + align:start position:0% +runs on 20 000 watts so one of the cool +things about the human brain is not just + + align:start position:0% +things about the human brain is not just + + + align:start position:0% +things about the human brain is not just +all the awesome stuff that we can do + + align:start position:0% +all the awesome stuff that we can do + + + align:start position:0% +all the awesome stuff that we can do +that still no computer can do that i + + align:start position:0% +that still no computer can do that i + + + align:start position:0% +that still no computer can do that i +talked about last time but also how + + align:start position:0% +talked about last time but also how + + + align:start position:0% +talked about last time but also how +incredibly energetically efficiently we + + align:start position:0% +incredibly energetically efficiently we + + + align:start position:0% +incredibly energetically efficiently we +do it with our human brains + + align:start position:0% +do it with our human brains + + + align:start position:0% +do it with our human brains +so most of this course is going to talk + + align:start position:0% +so most of this course is going to talk + + + align:start position:0% +so most of this course is going to talk +about the cortex that's all the stuff on + + align:start position:0% +about the cortex that's all the stuff on + + + align:start position:0% +about the cortex that's all the stuff on +the outside of the brain it's a sheet + + align:start position:0% +the outside of the brain it's a sheet + + + align:start position:0% +the outside of the brain it's a sheet +wrapping around the outside of the brain + + align:start position:0% + + + + align:start position:0% + +that folded outer surface + + align:start position:0% +that folded outer surface + + + align:start position:0% +that folded outer surface +it's approx approximately the size and + + align:start position:0% +it's approx approximately the size and + + + align:start position:0% +it's approx approximately the size and +area of a large pizza + + align:start position:0% +area of a large pizza + + + align:start position:0% +area of a large pizza +but there are lots of other important + + align:start position:0% +but there are lots of other important + + + align:start position:0% +but there are lots of other important +bits too and i'm going to just do + + align:start position:0% +bits too and i'm going to just do + + + align:start position:0% +bits too and i'm going to just do +whirlwind tour of those other bits + + align:start position:0% +whirlwind tour of those other bits + + + align:start position:0% +whirlwind tour of those other bits +now okay so you can think of the brain + + align:start position:0% +now okay so you can think of the brain + + + align:start position:0% +now okay so you can think of the brain +as composed of four major kinds of + + align:start position:0% +as composed of four major kinds of + + + align:start position:0% +as composed of four major kinds of +components + + align:start position:0% +components + + + align:start position:0% +components +deep down in the bottom of the brain you + + align:start position:0% +deep down in the bottom of the brain you + + + align:start position:0% +deep down in the bottom of the brain you +have the brain stem where the spinal + + align:start position:0% +have the brain stem where the spinal + + + align:start position:0% +have the brain stem where the spinal +cord comes in here and the rest of the + + align:start position:0% +cord comes in here and the rest of the + + + align:start position:0% +cord comes in here and the rest of the +brain is up there and the brain stem is + + align:start position:0% +brain is up there and the brain stem is + + + align:start position:0% +brain is up there and the brain stem is +right down here and the cerebellum this + + align:start position:0% +right down here and the cerebellum this + + + align:start position:0% +right down here and the cerebellum this +little cauliflower-like thing that sits + + align:start position:0% +little cauliflower-like thing that sits + + + align:start position:0% +little cauliflower-like thing that sits +out right back there + + align:start position:0% +out right back there + + + align:start position:0% +out right back there +and + + align:start position:0% +and + + + align:start position:0% +and +in the middle of the brain you have the + + align:start position:0% +in the middle of the brain you have the + + + align:start position:0% +in the middle of the brain you have the +limbic system with a whole bunch of + + align:start position:0% +limbic system with a whole bunch of + + + align:start position:0% +limbic system with a whole bunch of +subcortical regions and we'll talk about + + align:start position:0% +subcortical regions and we'll talk about + + + align:start position:0% +subcortical regions and we'll talk about +a few of those in a moment + + align:start position:0% +a few of those in a moment + + + align:start position:0% +a few of those in a moment +and you have white matter all the cables + + align:start position:0% +and you have white matter all the cables + + + align:start position:0% +and you have white matter all the cables +and connections that go from one part of + + align:start position:0% +and connections that go from one part of + + + align:start position:0% +and connections that go from one part of +the brain to another part this is an + + align:start position:0% +the brain to another part this is an + + + align:start position:0% +the brain to another part this is an +actual dissected human brain and all + + align:start position:0% +actual dissected human brain and all + + + align:start position:0% +actual dissected human brain and all +those kind of weird fibrous things are + + align:start position:0% +those kind of weird fibrous things are + + + align:start position:0% +those kind of weird fibrous things are +bundles of axons connecting remote parts + + align:start position:0% +bundles of axons connecting remote parts + + + align:start position:0% +bundles of axons connecting remote parts +of the brain to each other you can see + + align:start position:0% +of the brain to each other you can see + + + align:start position:0% +of the brain to each other you can see +them in gross dissection okay + + align:start position:0% +them in gross dissection okay + + + align:start position:0% +them in gross dissection okay +and of course you have the cortex okay + + align:start position:0% +and of course you have the cortex okay + + + align:start position:0% +and of course you have the cortex okay +so these are just four major things to + + align:start position:0% +so these are just four major things to + + + align:start position:0% +so these are just four major things to +think about and before we spend the rest + + align:start position:0% +think about and before we spend the rest + + + align:start position:0% +think about and before we spend the rest +of the course on that we're going to do + + align:start position:0% +of the course on that we're going to do + + + align:start position:0% +of the course on that we're going to do +just a teeny little bit on the other + + align:start position:0% +just a teeny little bit on the other + + + align:start position:0% +just a teeny little bit on the other +major bits + + align:start position:0% +major bits + + + align:start position:0% +major bits +okay and i'm going fast so just stop me + + align:start position:0% +okay and i'm going fast so just stop me + + + align:start position:0% +okay and i'm going fast so just stop me +if any of this isn't clear + + align:start position:0% +if any of this isn't clear + + + align:start position:0% +if any of this isn't clear +all right + + align:start position:0% +all right + + + align:start position:0% +all right +so the reason we're doing this in part + + align:start position:0% +so the reason we're doing this in part + + + align:start position:0% +so the reason we're doing this in part +is that with a dissection of a brain + + align:start position:0% +is that with a dissection of a brain + + + align:start position:0% +is that with a dissection of a brain +some of the main things you see are + + align:start position:0% +some of the main things you see are + + + align:start position:0% +some of the main things you see are +those subcortical structures right and + + align:start position:0% +those subcortical structures right and + + + align:start position:0% +those subcortical structures right and +so even though the course is going to + + align:start position:0% +so even though the course is going to + + + align:start position:0% +so even though the course is going to +focus on the cortex each little + + align:start position:0% +focus on the cortex each little + + + align:start position:0% +focus on the cortex each little +different bit of the cortex to the naked + + align:start position:0% +different bit of the cortex to the naked + + + align:start position:0% +different bit of the cortex to the naked +eye looks like any other bit of the + + align:start position:0% +eye looks like any other bit of the + + + align:start position:0% +eye looks like any other bit of the +cortex it's the subcortical stuff that + + align:start position:0% +cortex it's the subcortical stuff that + + + align:start position:0% +cortex it's the subcortical stuff that +looks different right + + align:start position:0% +looks different right + + + align:start position:0% +looks different right +so that's why we're doing this okay bear + + align:start position:0% +so that's why we're doing this okay bear + + + align:start position:0% +so that's why we're doing this okay bear +basics on the brain stem + + align:start position:0% +basics on the brain stem + + + align:start position:0% +basics on the brain stem +you can think of it as a bunch of relays + + align:start position:0% +you can think of it as a bunch of relays + + + align:start position:0% +you can think of it as a bunch of relays +in here different uh centers that + + align:start position:0% +in here different uh centers that + + + align:start position:0% +in here different uh centers that +connect information coming up from the + + align:start position:0% +connect information coming up from the + + + align:start position:0% +connect information coming up from the +spinal cord and send it through into the + + align:start position:0% +spinal cord and send it through into the + + + align:start position:0% +spinal cord and send it through into the +cerebellum + + align:start position:0% +cerebellum + + + align:start position:0% +cerebellum +so it's in many ways the most primitive + + align:start position:0% +so it's in many ways the most primitive + + + align:start position:0% +so it's in many ways the most primitive +part of the brain that means it's shared + + align:start position:0% +part of the brain that means it's shared + + + align:start position:0% +part of the brain that means it's shared +with animals very that branched off from + + align:start position:0% +with animals very that branched off from + + + align:start position:0% +with animals very that branched off from +us very far back in in mammalian + + align:start position:0% +us very far back in in mammalian + + + align:start position:0% +us very far back in in mammalian +evolution + + align:start position:0% +evolution + + + align:start position:0% +evolution +but it's also essential to life okay so + + align:start position:0% +but it's also essential to life okay so + + + align:start position:0% +but it's also essential to life okay so +you can get by with most of your cortex + + align:start position:0% +you can get by with most of your cortex + + + align:start position:0% +you can get by with most of your cortex +gone like you may not have a lot of fun + + align:start position:0% +gone like you may not have a lot of fun + + + align:start position:0% +gone like you may not have a lot of fun +you may not really know what's going on + + align:start position:0% +you may not really know what's going on + + + align:start position:0% +you may not really know what's going on +but you will stay alive but you can't + + align:start position:0% +but you will stay alive but you can't + + + align:start position:0% +but you will stay alive but you can't +get by without your brain stem right + + align:start position:0% +get by without your brain stem right + + + align:start position:0% +get by without your brain stem right +it's a it controls all kinds of basic + + align:start position:0% +it's a it controls all kinds of basic + + + align:start position:0% +it's a it controls all kinds of basic +crucial bodily functions like breathing + + align:start position:0% +crucial bodily functions like breathing + + + align:start position:0% +crucial bodily functions like breathing +consciousness temporary temperature + + align:start position:0% +consciousness temporary temperature + + + align:start position:0% +consciousness temporary temperature +regulation etc so it's not interesting + + align:start position:0% +regulation etc so it's not interesting + + + align:start position:0% +regulation etc so it's not interesting +cognitively but it's crucial for life + + align:start position:0% +cognitively but it's crucial for life + + + align:start position:0% +cognitively but it's crucial for life +cerebellum this beautiful thing here + + align:start position:0% +cerebellum this beautiful thing here + + + align:start position:0% +cerebellum this beautiful thing here +it's basically involved in motor + + align:start position:0% +it's basically involved in motor + + + align:start position:0% +it's basically involved in motor +coordination + + align:start position:0% +coordination + + + align:start position:0% +coordination +but from there on out there's a huge + + align:start position:0% +but from there on out there's a huge + + + align:start position:0% +but from there on out there's a huge +debate about its possible role in + + align:start position:0% +debate about its possible role in + + + align:start position:0% +debate about its possible role in +cognition and so there's lots of brain + + align:start position:0% +cognition and so there's lots of brain + + + align:start position:0% +cognition and so there's lots of brain +imaging studies where people find that + + align:start position:0% +imaging studies where people find that + + + align:start position:0% +imaging studies where people find that +the cerebellum is engaged in all kinds + + align:start position:0% +the cerebellum is engaged in all kinds + + + align:start position:0% +the cerebellum is engaged in all kinds +of things from aspects of perception up + + align:start position:0% +of things from aspects of perception up + + + align:start position:0% +of things from aspects of perception up +through aspects of language + + align:start position:0% +through aspects of language + + + align:start position:0% +through aspects of language +understanding you can find activations + + align:start position:0% +understanding you can find activations + + + align:start position:0% +understanding you can find activations +um in brain imaging studies + + align:start position:0% +um in brain imaging studies + + + align:start position:0% +um in brain imaging studies +nonetheless the best guess is that you + + align:start position:0% +nonetheless the best guess is that you + + + align:start position:0% +nonetheless the best guess is that you +actually don't need a cerebellum uh for + + align:start position:0% +actually don't need a cerebellum uh for + + + align:start position:0% +actually don't need a cerebellum uh for +any of this + + align:start position:0% +any of this + + + align:start position:0% +any of this +so there's if anybody's interested i'm + + align:start position:0% +so there's if anybody's interested i'm + + + align:start position:0% +so there's if anybody's interested i'm +going to actually try to remember to put + + align:start position:0% +going to actually try to remember to put + + + align:start position:0% +going to actually try to remember to put +it up as an optional reading on the site + + align:start position:0% +it up as an optional reading on the site + + + align:start position:0% +it up as an optional reading on the site +there's a recent article in the atlantic + + align:start position:0% +there's a recent article in the atlantic + + + align:start position:0% +there's a recent article in the atlantic +or the new yorker + + align:start position:0% +or the new yorker + + + align:start position:0% +or the new yorker +about a kid who had no cerebellum + + align:start position:0% +about a kid who had no cerebellum + + + align:start position:0% +about a kid who had no cerebellum +and he learned to walk late and slow + + align:start position:0% +and he learned to walk late and slow + + + align:start position:0% +and he learned to walk late and slow +nobody knew what his problem was but he + + align:start position:0% +nobody knew what his problem was but he + + + align:start position:0% +nobody knew what his problem was but he +learned to do pretty much everything + + align:start position:0% +learned to do pretty much everything + + + align:start position:0% +learned to do pretty much everything +like he's pretty much fine his motor + + align:start position:0% +like he's pretty much fine his motor + + + align:start position:0% +like he's pretty much fine his motor +coordination isn't great but he's fine + + align:start position:0% +coordination isn't great but he's fine + + + align:start position:0% +coordination isn't great but he's fine +yeah how are you defining consciousness + + align:start position:0% +yeah how are you defining consciousness + + + align:start position:0% +yeah how are you defining consciousness +in this context oh that's a good + + align:start position:0% +in this context oh that's a good + + + align:start position:0% +in this context oh that's a good +question and it's a big question and + + align:start position:0% +question and it's a big question and + + + align:start position:0% +question and it's a big question and +it's a question that nobody knows how to + + align:start position:0% +it's a question that nobody knows how to + + + align:start position:0% +it's a question that nobody knows how to +answer not just me + + align:start position:0% +answer not just me + + + align:start position:0% +answer not just me +so christoph koh who does more of work + + align:start position:0% +so christoph koh who does more of work + + + align:start position:0% +so christoph koh who does more of work +on the neural basis of consciousness + + align:start position:0% +on the neural basis of consciousness + + + align:start position:0% +on the neural basis of consciousness +than just about anybody has been going + + align:start position:0% +than just about anybody has been going + + + align:start position:0% +than just about anybody has been going +around saying for about 15 years + + align:start position:0% +around saying for about 15 years + + + align:start position:0% +around saying for about 15 years +we must not get stuck on a premature + + align:start position:0% +we must not get stuck on a premature + + + align:start position:0% +we must not get stuck on a premature +definition of consciousness because we + + align:start position:0% +definition of consciousness because we + + + align:start position:0% +definition of consciousness because we +don't know what that thing is that we're + + align:start position:0% +don't know what that thing is that we're + + + align:start position:0% +don't know what that thing is that we're +trying to understand so i'll hide behind + + align:start position:0% +trying to understand so i'll hide behind + + + align:start position:0% +trying to understand so i'll hide behind +kristoff's uh perry of that question + + align:start position:0% +kristoff's uh perry of that question + + + align:start position:0% +kristoff's uh perry of that question +and say we'll talk about it later in the + + align:start position:0% +and say we'll talk about it later in the + + + align:start position:0% +and say we'll talk about it later in the +course but it's there are many different + + align:start position:0% +course but it's there are many different + + + align:start position:0% +course but it's there are many different +kind of ways of defining it from the + + align:start position:0% +kind of ways of defining it from the + + + align:start position:0% +kind of ways of defining it from the +difference of difference between being + + align:start position:0% +difference of difference between being + + + align:start position:0% +difference of difference between being +awake versus asleep which is some of the + + align:start position:0% +awake versus asleep which is some of the + + + align:start position:0% +awake versus asleep which is some of the +functions that go on here the difference + + align:start position:0% +functions that go on here the difference + + + align:start position:0% +functions that go on here the difference +between + + align:start position:0% +between + + + align:start position:0% +between +being kind of knocked out and completely + + align:start position:0% +being kind of knocked out and completely + + + align:start position:0% +being kind of knocked out and completely +unconscious under general anesthesia + + align:start position:0% +unconscious under general anesthesia + + + align:start position:0% +unconscious under general anesthesia +which is different from being asleep + + align:start position:0% +which is different from being asleep + + + align:start position:0% +which is different from being asleep +those kind of states of consciousness + + align:start position:0% +those kind of states of consciousness + + + align:start position:0% +those kind of states of consciousness +are regulated in part in here yeah + + align:start position:0% +are regulated in part in here yeah + + + align:start position:0% +are regulated in part in here yeah +okay so you can get by without a + + align:start position:0% +okay so you can get by without a + + + align:start position:0% +okay so you can get by without a +cerebellum but it's not recommended + + align:start position:0% +cerebellum but it's not recommended + + + align:start position:0% +cerebellum but it's not recommended +um moving right along all those + + align:start position:0% +um moving right along all those + + + align:start position:0% +um moving right along all those +subcortical bits we're just going to + + align:start position:0% +subcortical bits we're just going to + + + align:start position:0% +subcortical bits we're just going to +talk about three of the most important + + align:start position:0% +talk about three of the most important + + + align:start position:0% +talk about three of the most important +ones the thalamus this big guy right + + align:start position:0% +ones the thalamus this big guy right + + + align:start position:0% +ones the thalamus this big guy right +smack in the middle of the brain very + + align:start position:0% +smack in the middle of the brain very + + + align:start position:0% +smack in the middle of the brain very +large structure + + align:start position:0% +large structure + + + align:start position:0% +large structure +the hippocampus and the amygdala okay + + align:start position:0% +the hippocampus and the amygdala okay + + + align:start position:0% +the hippocampus and the amygdala okay +let's talk about the thalamus + + align:start position:0% +let's talk about the thalamus + + + align:start position:0% +let's talk about the thalamus +think about the thalamus as a grand + + align:start position:0% +think about the thalamus as a grand + + + align:start position:0% +think about the thalamus as a grand +central station of the brain okay with + + align:start position:0% +central station of the brain okay with + + + align:start position:0% +central station of the brain okay with +all of these connections going to all + + align:start position:0% +all of these connections going to all + + + align:start position:0% +all of these connections going to all +those parts of cortex coming in and out + + align:start position:0% +those parts of cortex coming in and out + + + align:start position:0% +those parts of cortex coming in and out +of the thalamus like that okay + + align:start position:0% +of the thalamus like that okay + + + align:start position:0% +of the thalamus like that okay +so one of the key things about the + + align:start position:0% +so one of the key things about the + + + align:start position:0% +so one of the key things about the +thalamus + + align:start position:0% +thalamus + + + align:start position:0% +thalamus +is that most of the incoming sensory + + align:start position:0% +is that most of the incoming sensory + + + align:start position:0% +is that most of the incoming sensory +information goes by way of the thalamus + + align:start position:0% +information goes by way of the thalamus + + + align:start position:0% +information goes by way of the thalamus +on route to the cortex + + align:start position:0% +on route to the cortex + + + align:start position:0% +on route to the cortex +okay so if you start with your ear + + align:start position:0% +okay so if you start with your ear + + + align:start position:0% +okay so if you start with your ear +there's sensory endings in your ear that + + align:start position:0% +there's sensory endings in your ear that + + + align:start position:0% +there's sensory endings in your ear that +we'll talk about later in the term and + + align:start position:0% +we'll talk about later in the term and + + + align:start position:0% +we'll talk about later in the term and +they send + + align:start position:0% +they send + + + align:start position:0% +they send +neurons into this thalamus here this + + align:start position:0% +neurons into this thalamus here this + + + align:start position:0% +neurons into this thalamus here this +yellow thing + + align:start position:0% +yellow thing + + + align:start position:0% +yellow thing +through a bunch of different stages they + + align:start position:0% +through a bunch of different stages they + + + align:start position:0% +through a bunch of different stages they +make a stop in the thalamus and then + + align:start position:0% +make a stop in the thalamus and then + + + align:start position:0% +make a stop in the thalamus and then +they come up here to this green patch + + align:start position:0% +they come up here to this green patch + + + align:start position:0% +they come up here to this green patch +which is auditory cortex + + align:start position:0% +which is auditory cortex + + + align:start position:0% +which is auditory cortex +okay + + align:start position:0% +okay + + + align:start position:0% +okay +similarly + + align:start position:0% +similarly + + + align:start position:0% +similarly +somatosensory endings touch sensors in + + align:start position:0% +somatosensory endings touch sensors in + + + align:start position:0% +somatosensory endings touch sensors in +your skin that enable you to feel when + + align:start position:0% +your skin that enable you to feel when + + + align:start position:0% +your skin that enable you to feel when +you're being touched + + align:start position:0% +you're being touched + + + align:start position:0% +you're being touched +come in through the skin + + align:start position:0% +come in through the skin + + + align:start position:0% +come in through the skin +and they make a stop in the thalamus and + + align:start position:0% +and they make a stop in the thalamus and + + + align:start position:0% +and they make a stop in the thalamus and +then they go up to somatosensory cortex + + align:start position:0% +then they go up to somatosensory cortex + + + align:start position:0% +then they go up to somatosensory cortex +up there + + align:start position:0% +up there + + + align:start position:0% +up there +okay + + align:start position:0% +okay + + + align:start position:0% +okay +similarly + + align:start position:0% +similarly + + + align:start position:0% +similarly +signals that come in from your eyes + + align:start position:0% +signals that come in from your eyes + + + align:start position:0% +signals that come in from your eyes +make a stop in the thalamus + + align:start position:0% +make a stop in the thalamus + + + align:start position:0% +make a stop in the thalamus +and then go up to visual cortex + + align:start position:0% +and then go up to visual cortex + + + align:start position:0% +and then go up to visual cortex +okay what's the name of the structure in + + align:start position:0% +okay what's the name of the structure in + + + align:start position:0% +okay what's the name of the structure in +the thalamus that those axons make a + + align:start position:0% +the thalamus that those axons make a + + + align:start position:0% +the thalamus that those axons make a +synapse in coming up from the eyes you + + align:start position:0% +synapse in coming up from the eyes you + + + align:start position:0% +synapse in coming up from the eyes you +make a synapse here and you go up oops + + align:start position:0% +make a synapse here and you go up oops + + + align:start position:0% +make a synapse here and you go up oops +you go up to visual cortex + + align:start position:0% +you go up to visual cortex + + + align:start position:0% +you go up to visual cortex +lgn perfect what does it stand for + + align:start position:0% +lgn perfect what does it stand for + + + align:start position:0% +lgn perfect what does it stand for +perfect okay you should know that it's + + align:start position:0% +perfect okay you should know that it's + + + align:start position:0% +perfect okay you should know that it's +this is review from + + align:start position:0% +this is review from + + + align:start position:0% +this is review from +900 901 okay + + align:start position:0% +900 901 okay + + + align:start position:0% +900 901 okay +um yes sorry okay + + align:start position:0% +um yes sorry okay + + + align:start position:0% +um yes sorry okay +which sensory modality does not go + + align:start position:0% +which sensory modality does not go + + + align:start position:0% +which sensory modality does not go +through the thalamus on route to cortex + + align:start position:0% +through the thalamus on route to cortex + + + align:start position:0% +through the thalamus on route to cortex +between the sensory nerve endings and + + align:start position:0% +between the sensory nerve endings and + + + align:start position:0% +between the sensory nerve endings and +the cortex + + align:start position:0% + + + + align:start position:0% + +sorry + + align:start position:0% +sorry + + + align:start position:0% +sorry +yes yes you guys are on the ball yes + + align:start position:0% +yes yes you guys are on the ball yes + + + align:start position:0% +yes yes you guys are on the ball yes +olfactory system is the one sensory + + align:start position:0% +olfactory system is the one sensory + + + align:start position:0% +olfactory system is the one sensory +modality that doesn't make a stop in the + + align:start position:0% +modality that doesn't make a stop in the + + + align:start position:0% +modality that doesn't make a stop in the +cortex + + align:start position:0% +cortex + + + align:start position:0% +cortex +you can sort of see that here from the + + align:start position:0% +you can sort of see that here from the + + + align:start position:0% +you can sort of see that here from the +nose it goes straight up into + + align:start position:0% +nose it goes straight up into + + + align:start position:0% +nose it goes straight up into +olfactory cortex right there + + align:start position:0% +olfactory cortex right there + + + align:start position:0% +olfactory cortex right there +all right so that's the um + + align:start position:0% +all right so that's the um + + + align:start position:0% +all right so that's the um +standard view of the thalamus as this + + align:start position:0% +standard view of the thalamus as this + + + align:start position:0% +standard view of the thalamus as this +kind of like relay station where all the + + align:start position:0% +kind of like relay station where all the + + + align:start position:0% +kind of like relay station where all the +external sensory information comes in + + align:start position:0% +external sensory information comes in + + + align:start position:0% +external sensory information comes in +there makes a stop and then goes up to + + align:start position:0% +there makes a stop and then goes up to + + + align:start position:0% +there makes a stop and then goes up to +cortex okay + + align:start position:0% +cortex okay + + + align:start position:0% +cortex okay +that's my thalamus act boom like that + + align:start position:0% +that's my thalamus act boom like that + + + align:start position:0% +that's my thalamus act boom like that +right okay + + align:start position:0% +right okay + + + align:start position:0% +right okay +but + + align:start position:0% +but + + + align:start position:0% +but +uh increasingly there's evidence that + + align:start position:0% +uh increasingly there's evidence that + + + align:start position:0% +uh increasingly there's evidence that +the thalamus is much more than a relay + + align:start position:0% +the thalamus is much more than a relay + + + align:start position:0% +the thalamus is much more than a relay +station and why would you bother with a + + align:start position:0% +station and why would you bother with a + + + align:start position:0% +station and why would you bother with a +relay anyway kind of doesn't mean + + align:start position:0% +relay anyway kind of doesn't mean + + + align:start position:0% +relay anyway kind of doesn't mean +anything kind of means like we don't + + align:start position:0% +anything kind of means like we don't + + + align:start position:0% +anything kind of means like we don't +know what's going on here because you + + align:start position:0% +know what's going on here because you + + + align:start position:0% +know what's going on here because you +wouldn't just make a synapse for no + + align:start position:0% +wouldn't just make a synapse for no + + + align:start position:0% +wouldn't just make a synapse for no +reason right um okay and so the first + + align:start position:0% +reason right um okay and so the first + + + align:start position:0% +reason right um okay and so the first +thing to note is there are lots of + + align:start position:0% +thing to note is there are lots of + + + align:start position:0% +thing to note is there are lots of +connections that go back down the other + + align:start position:0% +connections that go back down the other + + + align:start position:0% +connections that go back down the other +way there are ten times as many + + align:start position:0% +way there are ten times as many + + + align:start position:0% +way there are ten times as many +connections that go from primary visual + + align:start position:0% +connections that go from primary visual + + + align:start position:0% +connections that go from primary visual +cortex right here in me + + align:start position:0% +cortex right here in me + + + align:start position:0% +cortex right here in me +right here in the sky in red there are + + align:start position:0% +right here in the sky in red there are + + + align:start position:0% +right here in the sky in red there are +ten times as many that go backwards + + align:start position:0% +ten times as many that go backwards + + + align:start position:0% +ten times as many that go backwards +down to the thalamus + + align:start position:0% +down to the thalamus + + + align:start position:0% +down to the thalamus +as go forwards + + align:start position:0% +as go forwards + + + align:start position:0% +as go forwards +that's mind-blowing right information + + align:start position:0% +that's mind-blowing right information + + + align:start position:0% +that's mind-blowing right information +comes from the eyes up into the brain + + align:start position:0% +comes from the eyes up into the brain + + + align:start position:0% +comes from the eyes up into the brain +what the hell are those things doing + + align:start position:0% +what the hell are those things doing + + + align:start position:0% +what the hell are those things doing +going backwards okay + + align:start position:0% +going backwards okay + + + align:start position:0% +going backwards okay +well they're doing all kinds of + + align:start position:0% +well they're doing all kinds of + + + align:start position:0% +well they're doing all kinds of +interesting things so that's the first + + align:start position:0% +interesting things so that's the first + + + align:start position:0% +interesting things so that's the first +indication that the thalamus isn't just + + align:start position:0% +indication that the thalamus isn't just + + + align:start position:0% +indication that the thalamus isn't just +relaying stuff in a stupid passive way + + align:start position:0% +relaying stuff in a stupid passive way + + + align:start position:0% +relaying stuff in a stupid passive way +and the second whole line of work which + + align:start position:0% +and the second whole line of work which + + + align:start position:0% +and the second whole line of work which +many people are working on but i think + + align:start position:0% +many people are working on but i think + + + align:start position:0% +many people are working on but i think +some of the most awesome work on this + + align:start position:0% +some of the most awesome work on this + + + align:start position:0% +some of the most awesome work on this +topic is done by our own mike halasa in + + align:start position:0% +topic is done by our own mike halasa in + + + align:start position:0% +topic is done by our own mike halasa in +this department + + align:start position:0% +this department + + + align:start position:0% +this department +and he does these incredible studies + + align:start position:0% +and he does these incredible studies + + + align:start position:0% +and he does these incredible studies +that you can do in mice with these + + align:start position:0% +that you can do in mice with these + + + align:start position:0% +that you can do in mice with these +spectacular methods that we can't use in + + align:start position:0% +spectacular methods that we can't use in + + + align:start position:0% +spectacular methods that we can't use in +humans + + align:start position:0% +humans + + + align:start position:0% +humans +where he can really take apart the + + align:start position:0% +where he can really take apart the + + + align:start position:0% +where he can really take apart the +circuit in magnificent detail + + align:start position:0% +circuit in magnificent detail + + + align:start position:0% +circuit in magnificent detail +and he's showing that the thalamus is + + align:start position:0% +and he's showing that the thalamus is + + + align:start position:0% +and he's showing that the thalamus is +involved in all kinds of high-level + + align:start position:0% +involved in all kinds of high-level + + + align:start position:0% +involved in all kinds of high-level +cognitive computations in mice it's + + align:start position:0% +cognitive computations in mice it's + + + align:start position:0% +cognitive computations in mice it's +really stunning work when the mice have + + align:start position:0% +really stunning work when the mice have + + + align:start position:0% +really stunning work when the mice have +to switch from doing one task to another + + align:start position:0% +to switch from doing one task to another + + + align:start position:0% +to switch from doing one task to another +the thalamus plays a key role in gating + + align:start position:0% +the thalamus plays a key role in gating + + + align:start position:0% +the thalamus plays a key role in gating +the flow of information from one + + align:start position:0% +the flow of information from one + + + align:start position:0% +the flow of information from one +cortical region to another + + align:start position:0% +cortical region to another + + + align:start position:0% +cortical region to another +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right moving along they hit the + + align:start position:0% +all right moving along they hit the + + + align:start position:0% +all right moving along they hit the +campus i know you guys all learn about + + align:start position:0% +campus i know you guys all learn about + + + align:start position:0% +campus i know you guys all learn about +this the number one gripe in this + + align:start position:0% +this the number one gripe in this + + + align:start position:0% +this the number one gripe in this +department is we learn about hm in every + + align:start position:0% +department is we learn about hm in every + + + align:start position:0% +department is we learn about hm in every +course so that's going to happen here + + align:start position:0% +course so that's going to happen here + + + align:start position:0% +course so that's going to happen here +but it's going to last about 20 seconds + + align:start position:0% +but it's going to last about 20 seconds + + + align:start position:0% +but it's going to last about 20 seconds +so here it goes that's a normal slice of + + align:start position:0% +so here it goes that's a normal slice of + + + align:start position:0% +so here it goes that's a normal slice of +the brain like this here's the + + align:start position:0% +the brain like this here's the + + + align:start position:0% +the brain like this here's the +hippocampus on either side it's like a + + align:start position:0% +hippocampus on either side it's like a + + + align:start position:0% +hippocampus on either side it's like a +whole curled up deal right there and + + align:start position:0% +whole curled up deal right there and + + + align:start position:0% +whole curled up deal right there and +right there + + align:start position:0% +right there + + + align:start position:0% +right there +and here is hm's brain the famous hm who + + align:start position:0% +and here is hm's brain the famous hm who + + + align:start position:0% +and here is hm's brain the famous hm who +had surgery to remove his hippocampus on + + align:start position:0% +had surgery to remove his hippocampus on + + + align:start position:0% +had surgery to remove his hippocampus on +both sides and completely lost his + + align:start position:0% +both sides and completely lost his + + + align:start position:0% +both sides and completely lost his +episodic memory for anything that + + align:start position:0% +episodic memory for anything that + + + align:start position:0% +episodic memory for anything that +happened after his surgery okay you all + + align:start position:0% +happened after his surgery okay you all + + + align:start position:0% +happened after his surgery okay you all +remember that right + + align:start position:0% +remember that right + + + align:start position:0% +remember that right +if anybody hasn't heard of hm send me an + + align:start position:0% +if anybody hasn't heard of hm send me an + + + align:start position:0% +if anybody hasn't heard of hm send me an +email i'll give you some background + + align:start position:0% +email i'll give you some background + + + align:start position:0% +email i'll give you some background +reading + + align:start position:0% +reading + + + align:start position:0% +reading +okay so very loosely the hippocampus + + align:start position:0% +okay so very loosely the hippocampus + + + align:start position:0% +okay so very loosely the hippocampus +involved both in this kind of long-term + + align:start position:0% +involved both in this kind of long-term + + + align:start position:0% +involved both in this kind of long-term +episodic memory that hm lost and it also + + align:start position:0% +episodic memory that hm lost and it also + + + align:start position:0% +episodic memory that hm lost and it also +plays a key role in navigation which + + align:start position:0% +plays a key role in navigation which + + + align:start position:0% +plays a key role in navigation which +we'll talk about in + + align:start position:0% +we'll talk about in + + + align:start position:0% +we'll talk about in +great detail in a few weeks + + align:start position:0% +great detail in a few weeks + + + align:start position:0% +great detail in a few weeks +and i just want to say that some cases + + align:start position:0% +and i just want to say that some cases + + + align:start position:0% +and i just want to say that some cases +are even more extreme than hm + + align:start position:0% +are even more extreme than hm + + + align:start position:0% +are even more extreme than hm +so there's a case of lonnie sue johnson + + align:start position:0% +so there's a case of lonnie sue johnson + + + align:start position:0% +so there's a case of lonnie sue johnson +and i am trying to get you guys a video + + align:start position:0% +and i am trying to get you guys a video + + + align:start position:0% +and i am trying to get you guys a video +and i didn't get it in time but i'll + + align:start position:0% +and i didn't get it in time but i'll + + + align:start position:0% +and i didn't get it in time but i'll +show it to you later in the term if + + align:start position:0% +show it to you later in the term if + + + align:start position:0% +show it to you later in the term if +you're interested + + align:start position:0% +you're interested + + + align:start position:0% +you're interested +lonnie sue johnson had a viral infection + + align:start position:0% +lonnie sue johnson had a viral infection + + + align:start position:0% +lonnie sue johnson had a viral infection +that went up into her brain she was an + + align:start position:0% +that went up into her brain she was an + + + align:start position:0% +that went up into her brain she was an +extremely accomplished person she did + + align:start position:0% +extremely accomplished person she did + + + align:start position:0% +extremely accomplished person she did +illustrations on the cover of the new + + align:start position:0% +illustrations on the cover of the new + + + align:start position:0% +illustrations on the cover of the new +yorker she was a pilot she had her own + + align:start position:0% +yorker she was a pilot she had her own + + + align:start position:0% +yorker she was a pilot she had her own +farm when she raised you know lots of + + align:start position:0% +farm when she raised you know lots of + + + align:start position:0% +farm when she raised you know lots of +lots of stuff + + align:start position:0% +lots of stuff + + + align:start position:0% +lots of stuff +a very smart interesting multi-talented + + align:start position:0% +a very smart interesting multi-talented + + + align:start position:0% +a very smart interesting multi-talented +woman who had this + + align:start position:0% +woman who had this + + + align:start position:0% +woman who had this +terrible tragedy of getting viral + + align:start position:0% +terrible tragedy of getting viral + + + align:start position:0% +terrible tragedy of getting viral +encephalitis at i don't know what age + + align:start position:0% +encephalitis at i don't know what age + + + align:start position:0% +encephalitis at i don't know what age +but middle age + + align:start position:0% +but middle age + + + align:start position:0% +but middle age +and she now does not remember a single + + align:start position:0% +and she now does not remember a single + + + align:start position:0% +and she now does not remember a single +event in her life + + align:start position:0% +event in her life + + + align:start position:0% +event in her life +she's smart she's funny her personality + + align:start position:0% +she's smart she's funny her personality + + + align:start position:0% +she's smart she's funny her personality +is totally intact + + align:start position:0% +is totally intact + + + align:start position:0% +is totally intact +she can answer questions she can paint + + align:start position:0% +she can answer questions she can paint + + + align:start position:0% +she can answer questions she can paint +she can do all kinds of things but she + + align:start position:0% +she can do all kinds of things but she + + + align:start position:0% +she can do all kinds of things but she +does not remember a single event in her + + align:start position:0% +does not remember a single event in her + + + align:start position:0% +does not remember a single event in her +life + + align:start position:0% +life + + + align:start position:0% +life +that's pretty astonishing + + align:start position:0% +that's pretty astonishing + + + align:start position:0% +that's pretty astonishing +reflect on what it means to have a sense + + align:start position:0% +reflect on what it means to have a sense + + + align:start position:0% +reflect on what it means to have a sense +of self if you don't remember anything + + align:start position:0% +of self if you don't remember anything + + + align:start position:0% +of self if you don't remember anything +in your life yeah she remember her again + + align:start position:0% +in your life yeah she remember her again + + + align:start position:0% +in your life yeah she remember her again +that's a good question i'm not sure she + + align:start position:0% +that's a good question i'm not sure she + + + align:start position:0% +that's a good question i'm not sure she +might know her yes she does know her + + align:start position:0% +might know her yes she does know her + + + align:start position:0% +might know her yes she does know her +name actually it is evident in this + + align:start position:0% +name actually it is evident in this + + + align:start position:0% +name actually it is evident in this +video but the video well so you know she + + align:start position:0% +video but the video well so you know she + + + align:start position:0% +video but the video well so you know she +doesn't remember at one point in this + + align:start position:0% +doesn't remember at one point in this + + + align:start position:0% +doesn't remember at one point in this +video she's asked were you ever married + + align:start position:0% +video she's asked were you ever married + + + align:start position:0% +video she's asked were you ever married +and she's lovely and sweet and gentle + + align:start position:0% +and she's lovely and sweet and gentle + + + align:start position:0% +and she's lovely and sweet and gentle +and kind of low-key and she's like you + + align:start position:0% +and kind of low-key and she's like you + + + align:start position:0% +and kind of low-key and she's like you +know + + align:start position:0% +know + + + align:start position:0% +know +just don't remember i might have been i + + align:start position:0% +just don't remember i might have been i + + + align:start position:0% +just don't remember i might have been i +might have been she was married for 10 + + align:start position:0% +might have been she was married for 10 + + + align:start position:0% +might have been she was married for 10 +years + + align:start position:0% +years + + + align:start position:0% +years +so uh that's the hippocampus important + + align:start position:0% +so uh that's the hippocampus important + + + align:start position:0% +so uh that's the hippocampus important +you don't want to lose that one yeah + + align:start position:0% +you don't want to lose that one yeah + + + align:start position:0% +you don't want to lose that one yeah +about each other if the campus is using + + align:start position:0% +about each other if the campus is using + + + align:start position:0% +about each other if the campus is using +long-term memory why is it that it being + + align:start position:0% +long-term memory why is it that it being + + + align:start position:0% +long-term memory why is it that it being +removed causing to not form new memories + + align:start position:0% +removed causing to not form new memories + + + align:start position:0% +removed causing to not form new memories +well so long-term memory means you know + + align:start position:0% +well so long-term memory means you know + + + align:start position:0% +well so long-term memory means you know +it's a vague term it means the formation + + align:start position:0% +it's a vague term it means the formation + + + align:start position:0% +it's a vague term it means the formation +rich and retrieval of memories that are + + align:start position:0% +rich and retrieval of memories that are + + + align:start position:0% +rich and retrieval of memories that are +going to last a long time + + align:start position:0% +going to last a long time + + + align:start position:0% +going to last a long time +so in hm's case he can access a lot of + + align:start position:0% +so in hm's case he can access a lot of + + + align:start position:0% +so in hm's case he can access a lot of +the memories from before his injury + + align:start position:0% +the memories from before his injury + + + align:start position:0% +the memories from before his injury +in lonnie sue's case she can't do even + + align:start position:0% +in lonnie sue's case she can't do even + + + align:start position:0% +in lonnie sue's case she can't do even +that + + align:start position:0% +that + + + align:start position:0% +that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right + + align:start position:0% +all right + + + align:start position:0% +all right +amygdala + + align:start position:0% +amygdala + + + align:start position:0% +amygdala +okay amygdala is a greek word that means + + align:start position:0% +okay amygdala is a greek word that means + + + align:start position:0% +okay amygdala is a greek word that means +almond because the amygdala is the size + + align:start position:0% +almond because the amygdala is the size + + + align:start position:0% +almond because the amygdala is the size +and shape of an almond + + align:start position:0% +and shape of an almond + + + align:start position:0% +and shape of an almond +and so + + align:start position:0% +and so + + + align:start position:0% +and so +just for fun we're passing on her own my + + align:start position:0% +just for fun we're passing on her own my + + + align:start position:0% +just for fun we're passing on her own my +favorite kind have some almonds and pass + + align:start position:0% +favorite kind have some almonds and pass + + + align:start position:0% +favorite kind have some almonds and pass +them around all right + + align:start position:0% +them around all right + + + align:start position:0% +them around all right +um + + align:start position:0% +um + + + align:start position:0% +um +okay so the amygdala is involved in + + align:start position:0% +okay so the amygdala is involved in + + + align:start position:0% +okay so the amygdala is involved in +experiencing and recognizing emotions + + align:start position:0% +experiencing and recognizing emotions + + + align:start position:0% +experiencing and recognizing emotions +especially fear + + align:start position:0% +especially fear + + + align:start position:0% +especially fear +the simple statement that you should + + align:start position:0% +the simple statement that you should + + + align:start position:0% +the simple statement that you should +remember about what the amygdala does + + align:start position:0% +remember about what the amygdala does + + + align:start position:0% +remember about what the amygdala does +is just remember the four f's you guys + + align:start position:0% +is just remember the four f's you guys + + + align:start position:0% +is just remember the four f's you guys +all know about the four f's + + align:start position:0% +all know about the four f's + + + align:start position:0% +all know about the four f's +fighting fleeing feeding and mating + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% +okay + + + align:start position:0% +okay +patient sm + + align:start position:0% +patient sm + + + align:start position:0% +patient sm +lost her amygdala on both sides + + align:start position:0% +lost her amygdala on both sides + + + align:start position:0% +lost her amygdala on both sides +okay + + align:start position:0% +okay + + + align:start position:0% +okay +she cannot experience fear + + align:start position:0% +she cannot experience fear + + + align:start position:0% +she cannot experience fear +she doesn't recognize fear on facial + + align:start position:0% +she doesn't recognize fear on facial + + + align:start position:0% +she doesn't recognize fear on facial +expressions of other people and she + + align:start position:0% +expressions of other people and she + + + align:start position:0% +expressions of other people and she +doesn't experience fear herself + + align:start position:0% +doesn't experience fear herself + + + align:start position:0% +doesn't experience fear herself +okay and so that's a the striking um + + align:start position:0% +okay and so that's a the striking um + + + align:start position:0% +okay and so that's a the striking um +piece of evidence on what the amygdala + + align:start position:0% +piece of evidence on what the amygdala + + + align:start position:0% +piece of evidence on what the amygdala +does her face recognition is normal + + align:start position:0% +does her face recognition is normal + + + align:start position:0% +does her face recognition is normal +recognizing identities + + align:start position:0% +recognizing identities + + + align:start position:0% +recognizing identities +her iq is normal + + align:start position:0% +her iq is normal + + + align:start position:0% +her iq is normal +she's overly trusting of other people + + align:start position:0% +she's overly trusting of other people + + + align:start position:0% +she's overly trusting of other people +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um okay so that's all you need to know + + align:start position:0% +um okay so that's all you need to know + + + align:start position:0% +um okay so that's all you need to know +about the amygdala for now + + align:start position:0% +about the amygdala for now + + + align:start position:0% +about the amygdala for now +um okay let's talk about white matter + + align:start position:0% +um okay let's talk about white matter + + + align:start position:0% +um okay let's talk about white matter +just brief review here's a here's a kind + + align:start position:0% +just brief review here's a here's a kind + + + align:start position:0% +just brief review here's a here's a kind +of tunnel through a piece of cortex okay + + align:start position:0% +of tunnel through a piece of cortex okay + + + align:start position:0% +of tunnel through a piece of cortex okay +so my brain cortex is wrapping around + + align:start position:0% +so my brain cortex is wrapping around + + + align:start position:0% +so my brain cortex is wrapping around +like that if we took a piece like this + + align:start position:0% +like that if we took a piece like this + + + align:start position:0% +like that if we took a piece like this +just took a segment out like that this + + align:start position:0% +just took a segment out like that this + + + align:start position:0% +just took a segment out like that this +is the outside of the brain up there + + align:start position:0% +is the outside of the brain up there + + + align:start position:0% +is the outside of the brain up there +cortex runs like this + + align:start position:0% +cortex runs like this + + + align:start position:0% +cortex runs like this +and gray matter is the stuff on the + + align:start position:0% +and gray matter is the stuff on the + + + align:start position:0% +and gray matter is the stuff on the +outer surface that's full of cell bodies + + align:start position:0% +outer surface that's full of cell bodies + + + align:start position:0% +outer surface that's full of cell bodies +okay + + align:start position:0% +okay + + + align:start position:0% +okay +white matter + + align:start position:0% +white matter + + + align:start position:0% +white matter +are the axons the processes that come + + align:start position:0% +are the axons the processes that come + + + align:start position:0% +are the axons the processes that come +out of those cell bodies and travel + + align:start position:0% +out of those cell bodies and travel + + + align:start position:0% +out of those cell bodies and travel +elsewhere in the brain + + align:start position:0% +elsewhere in the brain + + + align:start position:0% +elsewhere in the brain +okay everybody clear on that okay so + + align:start position:0% +okay everybody clear on that okay so + + + align:start position:0% +okay everybody clear on that okay so +we've got gray matter up here and white + + align:start position:0% +we've got gray matter up here and white + + + align:start position:0% +we've got gray matter up here and white +matter down there + + align:start position:0% +matter down there + + + align:start position:0% +matter down there +mostly myelinated axons that have that + + align:start position:0% +mostly myelinated axons that have that + + + align:start position:0% +mostly myelinated axons that have that +layer of fat to make them conduct fast + + align:start position:0% +layer of fat to make them conduct fast + + + align:start position:0% +layer of fat to make them conduct fast +and so you'll see bundles of white + + align:start position:0% +and so you'll see bundles of white + + + align:start position:0% +and so you'll see bundles of white +matter in the dissection + + align:start position:0% +matter in the dissection + + + align:start position:0% +matter in the dissection +and so here's an actual picture + + align:start position:0% +and so here's an actual picture + + + align:start position:0% +and so here's an actual picture +photograph of the slice through a brain + + align:start position:0% +photograph of the slice through a brain + + + align:start position:0% +photograph of the slice through a brain +so all that white stuff up there is + + align:start position:0% +so all that white stuff up there is + + + align:start position:0% +so all that white stuff up there is +white matter okay + + align:start position:0% +white matter okay + + + align:start position:0% +white matter okay +and so you might say well it's just a + + align:start position:0% +and so you might say well it's just a + + + align:start position:0% +and so you might say well it's just a +big bunch of wires + + align:start position:0% +big bunch of wires + + + align:start position:0% +big bunch of wires +who cares about that + + align:start position:0% +who cares about that + + + align:start position:0% +who cares about that +it's a good question but actually the + + align:start position:0% +it's a good question but actually the + + + align:start position:0% +it's a good question but actually the +wires are pretty damn interesting and + + align:start position:0% +wires are pretty damn interesting and + + + align:start position:0% +wires are pretty damn interesting and +pretty fundamental + + align:start position:0% +pretty fundamental + + + align:start position:0% +pretty fundamental +and so i'll just give you a few reasons + + align:start position:0% +and so i'll just give you a few reasons + + + align:start position:0% +and so i'll just give you a few reasons +and you don't need to memorize every one + + align:start position:0% +and you don't need to memorize every one + + + align:start position:0% +and you don't need to memorize every one +of these i'm just trying to give you a + + align:start position:0% +of these i'm just trying to give you a + + + align:start position:0% +of these i'm just trying to give you a +gist of why we might care about this and + + align:start position:0% +gist of why we might care about this and + + + align:start position:0% +gist of why we might care about this and +there will be a whole other lecture on + + align:start position:0% +there will be a whole other lecture on + + + align:start position:0% +there will be a whole other lecture on +networks and connectivity later in the + + align:start position:0% +networks and connectivity later in the + + + align:start position:0% +networks and connectivity later in the +course well first of all white matter is + + align:start position:0% +course well first of all white matter is + + + align:start position:0% +course well first of all white matter is +45 of the human brain + + align:start position:0% +45 of the human brain + + + align:start position:0% +45 of the human brain +okay so takes up a lot of space all + + align:start position:0% +okay so takes up a lot of space all + + + align:start position:0% +okay so takes up a lot of space all +those wires connecting one bit to + + align:start position:0% +those wires connecting one bit to + + + align:start position:0% +those wires connecting one bit to +another bit + + align:start position:0% +another bit + + + align:start position:0% +another bit +and i would say we cannot possibly + + align:start position:0% +and i would say we cannot possibly + + + align:start position:0% +and i would say we cannot possibly +understand the cortex and how it works + + align:start position:0% +understand the cortex and how it works + + + align:start position:0% +understand the cortex and how it works +or any little piece of it without + + align:start position:0% +or any little piece of it without + + + align:start position:0% +or any little piece of it without +knowing the connectivity of each piece + + align:start position:0% +knowing the connectivity of each piece + + + align:start position:0% +knowing the connectivity of each piece +to each other bit of the cortex right + + align:start position:0% +to each other bit of the cortex right + + + align:start position:0% +to each other bit of the cortex right +imagine trying to understand a computer + + align:start position:0% +imagine trying to understand a computer + + + align:start position:0% +imagine trying to understand a computer +or a circuit without being able to see + + align:start position:0% +or a circuit without being able to see + + + align:start position:0% +or a circuit without being able to see +the connections between the bits like it + + align:start position:0% +the connections between the bits like it + + + align:start position:0% +the connections between the bits like it +would drive you crazy that's a situation + + align:start position:0% +would drive you crazy that's a situation + + + align:start position:0% +would drive you crazy that's a situation +we're in now in human cognitive + + align:start position:0% +we're in now in human cognitive + + + align:start position:0% +we're in now in human cognitive +neuroscience it frankly drives me insane + + align:start position:0% +neuroscience it frankly drives me insane + + + align:start position:0% +neuroscience it frankly drives me insane +but that's where we are + + align:start position:0% +but that's where we are + + + align:start position:0% +but that's where we are +um + + align:start position:0% +um + + + align:start position:0% +um +next thing + + align:start position:0% +next thing + + + align:start position:0% +next thing +the long-range connectivity of each + + align:start position:0% +the long-range connectivity of each + + + align:start position:0% +the long-range connectivity of each +little bit of cortex some little bit + + align:start position:0% +little bit of cortex some little bit + + + align:start position:0% +little bit of cortex some little bit +right there in my brain is connected to + + align:start position:0% +right there in my brain is connected to + + + align:start position:0% +right there in my brain is connected to +some bunch of other remote regions in my + + align:start position:0% +some bunch of other remote regions in my + + + align:start position:0% +some bunch of other remote regions in my +brain and that particular set of + + align:start position:0% +brain and that particular set of + + + align:start position:0% +brain and that particular set of +connections is distinctive for that + + align:start position:0% +connections is distinctive for that + + + align:start position:0% +connections is distinctive for that +patch of cortex + + align:start position:0% +patch of cortex + + + align:start position:0% +patch of cortex +so you can think of it as a connectivity + + align:start position:0% +so you can think of it as a connectivity + + + align:start position:0% +so you can think of it as a connectivity +fingerprint of a patch of cortex + + align:start position:0% +fingerprint of a patch of cortex + + + align:start position:0% +fingerprint of a patch of cortex +okay so one of the ways that the + + align:start position:0% +okay so one of the ways that the + + + align:start position:0% +okay so one of the ways that the +different bits differ from each other is + + align:start position:0% +different bits differ from each other is + + + align:start position:0% +different bits differ from each other is +by way of their connectivity + + align:start position:0% +by way of their connectivity + + + align:start position:0% +by way of their connectivity +fingerprints + + align:start position:0% +fingerprints + + + align:start position:0% +fingerprints +and i'm going to skip the rest of these + + align:start position:0% +and i'm going to skip the rest of these + + + align:start position:0% +and i'm going to skip the rest of these +because we're going to get back to them + + align:start position:0% +because we're going to get back to them + + + align:start position:0% +because we're going to get back to them +later + + align:start position:0% +later + + + align:start position:0% +later +and i'm going to run out of time i'm + + align:start position:0% +and i'm going to run out of time i'm + + + align:start position:0% +and i'm going to run out of time i'm +going to assign the tas to sound the + + align:start position:0% +going to assign the tas to sound the + + + align:start position:0% +going to assign the tas to sound the +gong at 12 15. okay good + + align:start position:0% +gong at 12 15. okay good + + + align:start position:0% +gong at 12 15. okay good +all right + + align:start position:0% +all right + + + align:start position:0% +all right +now we're up to the cortex this is + + align:start position:0% +now we're up to the cortex this is + + + align:start position:0% +now we're up to the cortex this is +really laughably + + align:start position:0% +really laughably + + + align:start position:0% +really laughably +shallow but whatever that's what we're + + align:start position:0% +shallow but whatever that's what we're + + + align:start position:0% +shallow but whatever that's what we're +doing here + + align:start position:0% +doing here + + + align:start position:0% +doing here +so here's this cortex and as i mentioned + + align:start position:0% +so here's this cortex and as i mentioned + + + align:start position:0% +so here's this cortex and as i mentioned +it's a whole big sheet and the different + + align:start position:0% +it's a whole big sheet and the different + + + align:start position:0% +it's a whole big sheet and the different +bits look really similar if you just + + align:start position:0% +bits look really similar if you just + + + align:start position:0% +bits look really similar if you just +look at them or slice them up + + align:start position:0% +look at them or slice them up + + + align:start position:0% +look at them or slice them up +so how are we going to figure out how + + align:start position:0% +so how are we going to figure out how + + + align:start position:0% +so how are we going to figure out how +this thing is organized + + align:start position:0% +this thing is organized + + + align:start position:0% +this thing is organized +well + + align:start position:0% +well + + + align:start position:0% +well +okay now we're up here talking about + + align:start position:0% +okay now we're up here talking about + + + align:start position:0% +okay now we're up here talking about +cortex all right let's start with the + + align:start position:0% +cortex all right let's start with the + + + align:start position:0% +cortex all right let's start with the +easy parts which you've already seen + + align:start position:0% +easy parts which you've already seen + + + align:start position:0% +easy parts which you've already seen +you've already seen this up here these + + align:start position:0% +you've already seen this up here these + + + align:start position:0% +you've already seen this up here these +colored bits visual cortex auditory + + align:start position:0% +colored bits visual cortex auditory + + + align:start position:0% +colored bits visual cortex auditory +cortex + + align:start position:0% +cortex + + + align:start position:0% +cortex +um + + align:start position:0% +um + + + align:start position:0% +um +somatosensory cortex + + align:start position:0% +somatosensory cortex + + + align:start position:0% +somatosensory cortex +gustatory taste cortex + + align:start position:0% +gustatory taste cortex + + + align:start position:0% +gustatory taste cortex +those bits + + align:start position:0% +those bits + + + align:start position:0% +those bits +are like the easy parts of cortex those + + align:start position:0% +are like the easy parts of cortex those + + + align:start position:0% +are like the easy parts of cortex those +are called primary sensory regions + + align:start position:0% +are called primary sensory regions + + + align:start position:0% +are called primary sensory regions +there's also motor cortex right in front + + align:start position:0% +there's also motor cortex right in front + + + align:start position:0% +there's also motor cortex right in front +of sensory cortex so those are the + + align:start position:0% +of sensory cortex so those are the + + + align:start position:0% +of sensory cortex so those are the +primary regions + + align:start position:0% +primary regions + + + align:start position:0% +primary regions +their primary in the sense of this is + + align:start position:0% +their primary in the sense of this is + + + align:start position:0% +their primary in the sense of this is +the first place that sensory information + + align:start position:0% +the first place that sensory information + + + align:start position:0% +the first place that sensory information +lands up at the cortex coming up from + + align:start position:0% +lands up at the cortex coming up from + + + align:start position:0% +lands up at the cortex coming up from +the senses right + + align:start position:0% +the senses right + + + align:start position:0% +the senses right +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +and all of that input is wired through + + align:start position:0% +and all of that input is wired through + + + align:start position:0% +and all of that input is wired through +what structure + + align:start position:0% + + + + align:start position:0% + +yes thank you + + align:start position:0% +yes thank you + + + align:start position:0% +yes thank you +um so how are these regions organized + + align:start position:0% +um so how are these regions organized + + + align:start position:0% +um so how are these regions organized +um well they have maps every one of + + align:start position:0% +um well they have maps every one of + + + align:start position:0% +um well they have maps every one of +these regions has a map + + align:start position:0% +these regions has a map + + + align:start position:0% +these regions has a map +and each of them has a map of a + + align:start position:0% +and each of them has a map of a + + + align:start position:0% +and each of them has a map of a +different thing so let's start with + + align:start position:0% +different thing so let's start with + + + align:start position:0% +different thing so let's start with +visual cortex + + align:start position:0% +visual cortex + + + align:start position:0% +visual cortex +and we're going to talk about the map + + align:start position:0% +and we're going to talk about the map + + + align:start position:0% +and we're going to talk about the map +that lives in visual cortex but the + + align:start position:0% +that lives in visual cortex but the + + + align:start position:0% +that lives in visual cortex but the +prior condition for understanding that + + align:start position:0% +prior condition for understanding that + + + align:start position:0% +prior condition for understanding that +map is to understand the concept of + + align:start position:0% +map is to understand the concept of + + + align:start position:0% +map is to understand the concept of +receptive field which you should know so + + align:start position:0% +receptive field which you should know so + + + align:start position:0% +receptive field which you should know so +i'm going to whip through it quickly + + align:start position:0% +i'm going to whip through it quickly + + + align:start position:0% +i'm going to whip through it quickly +okay so here is how you map the + + align:start position:0% +okay so here is how you map the + + + align:start position:0% +okay so here is how you map the +receptive field as a property of an + + align:start position:0% +receptive field as a property of an + + + align:start position:0% +receptive field as a property of an +individual cell + + align:start position:0% +individual cell + + + align:start position:0% +individual cell +in a brain okay so the classic way in + + align:start position:0% +in a brain okay so the classic way in + + + align:start position:0% +in a brain okay so the classic way in +animal neuroscience is you place an + + align:start position:0% +animal neuroscience is you place an + + + align:start position:0% +animal neuroscience is you place an +electrode in the brain next to a neuron + + align:start position:0% +electrode in the brain next to a neuron + + + align:start position:0% +electrode in the brain next to a neuron +in monkey visual cortex + + align:start position:0% +in monkey visual cortex + + + align:start position:0% +in monkey visual cortex +okay so here's this monkey's gun + + align:start position:0% +okay so here's this monkey's gun + + + align:start position:0% +okay so here's this monkey's gun +electrode right in his brain right next + + align:start position:0% +electrode right in his brain right next + + + align:start position:0% +electrode right in his brain right next +to a neuron and visual cortex and every + + align:start position:0% +to a neuron and visual cortex and every + + + align:start position:0% +to a neuron and visual cortex and every +time that neuron fires + + align:start position:0% +time that neuron fires + + + align:start position:0% +time that neuron fires +you get a spike you hear a spike okay + + align:start position:0% +you get a spike you hear a spike okay + + + align:start position:0% +you get a spike you hear a spike okay +now you train the monkey to stare at a + + align:start position:0% +now you train the monkey to stare at a + + + align:start position:0% +now you train the monkey to stare at a +fixation spot without moving its eyes + + align:start position:0% +fixation spot without moving its eyes + + + align:start position:0% +fixation spot without moving its eyes +okay i can do this with humans without + + align:start position:0% +okay i can do this with humans without + + + align:start position:0% +okay i can do this with humans without +training you i can just tell you look at + + align:start position:0% +training you i can just tell you look at + + + align:start position:0% +training you i can just tell you look at +the tip of my nose okay so keep your + + align:start position:0% +the tip of my nose okay so keep your + + + align:start position:0% +the tip of my nose okay so keep your +eyes on the tip of my nose i can see if + + align:start position:0% +eyes on the tip of my nose i can see if + + + align:start position:0% +eyes on the tip of my nose i can see if +you're looking elsewhere so look at the + + align:start position:0% +you're looking elsewhere so look at the + + + align:start position:0% +you're looking elsewhere so look at the +tip of my nose okay okay so you train a + + align:start position:0% +tip of my nose okay okay so you train a + + + align:start position:0% +tip of my nose okay okay so you train a +monkey to do that that takes a few + + align:start position:0% +monkey to do that that takes a few + + + align:start position:0% +monkey to do that that takes a few +months and then they can do that + + align:start position:0% +months and then they can do that + + + align:start position:0% +months and then they can do that +and then while recording from neurons in + + align:start position:0% +and then while recording from neurons in + + + align:start position:0% +and then while recording from neurons in +his brain you put stimuli over here put + + align:start position:0% +his brain you put stimuli over here put + + + align:start position:0% +his brain you put stimuli over here put +a flash over there or a flash over here + + align:start position:0% +a flash over there or a flash over here + + + align:start position:0% +a flash over there or a flash over here +or a flash over here or flash over here + + align:start position:0% +or a flash over here or flash over here + + + align:start position:0% +or a flash over here or flash over here +okay you can stop looking at my nose + + align:start position:0% +okay you can stop looking at my nose + + + align:start position:0% +okay you can stop looking at my nose +it's not all that fabulous knows i + + align:start position:0% +it's not all that fabulous knows i + + + align:start position:0% +it's not all that fabulous knows i +realize okay + + align:start position:0% +realize okay + + + align:start position:0% +realize okay +so a receptive field + + align:start position:0% +so a receptive field + + + align:start position:0% +so a receptive field +is the place in the visual world that + + align:start position:0% +is the place in the visual world that + + + align:start position:0% +is the place in the visual world that +makes a given neuron fire + + align:start position:0% +makes a given neuron fire + + + align:start position:0% +makes a given neuron fire +okay so if there's a neuron in your + + align:start position:0% +okay so if there's a neuron in your + + + align:start position:0% +okay so if there's a neuron in your +brain that responds to a flash here but + + align:start position:0% +brain that responds to a flash here but + + + align:start position:0% +brain that responds to a flash here but +not a flash here or here or here or here + + align:start position:0% +not a flash here or here or here or here + + + align:start position:0% +not a flash here or here or here or here +the receptive field of that neuron is + + align:start position:0% +the receptive field of that neuron is + + + align:start position:0% +the receptive field of that neuron is +right there everybody got that idea + + align:start position:0% +right there everybody got that idea + + + align:start position:0% +right there everybody got that idea +okay so in visual cortex neurons have + + align:start position:0% +okay so in visual cortex neurons have + + + align:start position:0% +okay so in visual cortex neurons have +restricted receptive fields they don't + + align:start position:0% +restricted receptive fields they don't + + + align:start position:0% +restricted receptive fields they don't +respond to anything anywhere in the + + align:start position:0% +respond to anything anywhere in the + + + align:start position:0% +respond to anything anywhere in the +visual field they respond to a + + align:start position:0% +visual field they respond to a + + + align:start position:0% +visual field they respond to a +particular place in space + + align:start position:0% +particular place in space + + + align:start position:0% +particular place in space +okay if that's confusing at all ask a + + align:start position:0% +okay if that's confusing at all ask a + + + align:start position:0% +okay if that's confusing at all ask a +question because it will come up again + + align:start position:0% +question because it will come up again + + + align:start position:0% +question because it will come up again +and again + + align:start position:0% +and again + + + align:start position:0% +and again +all right so that's what the rest of + + align:start position:0% +all right so that's what the rest of + + + align:start position:0% +all right so that's what the rest of +this slide says what i just said blah + + align:start position:0% +this slide says what i just said blah + + + align:start position:0% +this slide says what i just said blah +blah blah doesn't matter that's a + + align:start position:0% +blah blah doesn't matter that's a + + + align:start position:0% +blah blah doesn't matter that's a +receptive field different visual neurons + + align:start position:0% +receptive field different visual neurons + + + align:start position:0% +receptive field different visual neurons +have different receptive fields + + align:start position:0% +have different receptive fields + + + align:start position:0% +have different receptive fields +for different parts of space + + align:start position:0% +for different parts of space + + + align:start position:0% +for different parts of space +now here comes the important idea in + + align:start position:0% +now here comes the important idea in + + + align:start position:0% +now here comes the important idea in +visual cortex two neurons that are next + + align:start position:0% +visual cortex two neurons that are next + + + align:start position:0% +visual cortex two neurons that are next +to each other in visual cortex have + + align:start position:0% +to each other in visual cortex have + + + align:start position:0% +to each other in visual cortex have +nearby receptive fields + + align:start position:0% +nearby receptive fields + + + align:start position:0% +nearby receptive fields +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that's the concept of retina topi + + align:start position:0% +so that's the concept of retina topi + + + align:start position:0% +so that's the concept of retina topi +or the map in visual cortex so you + + align:start position:0% +or the map in visual cortex so you + + + align:start position:0% +or the map in visual cortex so you +basically have a map of the visual world + + align:start position:0% +basically have a map of the visual world + + + align:start position:0% +basically have a map of the visual world +in your visual cortex because there's + + align:start position:0% +in your visual cortex because there's + + + align:start position:0% +in your visual cortex because there's +this systematic layout just like you + + align:start position:0% +this systematic layout just like you + + + align:start position:0% +this systematic layout just like you +have in your retina in your retina + + align:start position:0% +have in your retina in your retina + + + align:start position:0% +have in your retina in your retina +visual information comes in and because + + align:start position:0% +visual information comes in and because + + + align:start position:0% +visual information comes in and because +of optics different parts of your retina + + align:start position:0% +of optics different parts of your retina + + + align:start position:0% +of optics different parts of your retina +respond to different parts of the image + + align:start position:0% +respond to different parts of the image + + + align:start position:0% +respond to different parts of the image +but that information is propagated back + + align:start position:0% +but that information is propagated back + + + align:start position:0% +but that information is propagated back +through the lgn up to primary visual + + align:start position:0% +through the lgn up to primary visual + + + align:start position:0% +through the lgn up to primary visual +cortex where you still have a map of the + + align:start position:0% +cortex where you still have a map of the + + + align:start position:0% +cortex where you still have a map of the +visual space up in primary visual cortex + + align:start position:0% +visual space up in primary visual cortex + + + align:start position:0% +visual space up in primary visual cortex +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that map is called retinotopic in + + align:start position:0% +so that map is called retinotopic in + + + align:start position:0% +so that map is called retinotopic in +visual cortex because it's + + align:start position:0% +visual cortex because it's + + + align:start position:0% +visual cortex because it's +oriented like the retina + + align:start position:0% +oriented like the retina + + + align:start position:0% +oriented like the retina +and so here's a particularly kind of + + align:start position:0% +and so here's a particularly kind of + + + align:start position:0% +and so here's a particularly kind of +gruesome but very literal depiction of + + align:start position:0% +gruesome but very literal depiction of + + + align:start position:0% +gruesome but very literal depiction of +this property of retina topi + + align:start position:0% +this property of retina topi + + + align:start position:0% +this property of retina topi +in a monkey brain this is an experiment + + align:start position:0% +in a monkey brain this is an experiment + + + align:start position:0% +in a monkey brain this is an experiment +done very long ago by roger tutel + + align:start position:0% +done very long ago by roger tutel + + + align:start position:0% +done very long ago by roger tutel +and what he did was um + + align:start position:0% +and what he did was um + + + align:start position:0% +and what he did was um +he used a method called deoxyglucose and + + align:start position:0% +he used a method called deoxyglucose and + + + align:start position:0% +he used a method called deoxyglucose and +so what deoxyglucose + + align:start position:0% +so what deoxyglucose + + + align:start position:0% +so what deoxyglucose +is a molecule that's a whole lot like + + align:start position:0% +is a molecule that's a whole lot like + + + align:start position:0% +is a molecule that's a whole lot like +glucose + + align:start position:0% +glucose + + + align:start position:0% +glucose +but it's got one little change in the + + align:start position:0% +but it's got one little change in the + + + align:start position:0% +but it's got one little change in the +molecule which means it gets stuck on + + align:start position:0% +molecule which means it gets stuck on + + + align:start position:0% +molecule which means it gets stuck on +the metabolic chain and so it gets taken + + align:start position:0% +the metabolic chain and so it gets taken + + + align:start position:0% +the metabolic chain and so it gets taken +up by cells that want to take up glucose + + align:start position:0% +up by cells that want to take up glucose + + + align:start position:0% +up by cells that want to take up glucose +and then it gets stuck in there and + + align:start position:0% +and then it gets stuck in there and + + + align:start position:0% +and then it gets stuck in there and +can't be broken down so it builds up in + + align:start position:0% +can't be broken down so it builds up in + + + align:start position:0% +can't be broken down so it builds up in +cells that are metabolically active + + align:start position:0% +cells that are metabolically active + + + align:start position:0% +cells that are metabolically active +okay so you can put a little radioactive + + align:start position:0% +okay so you can put a little radioactive + + + align:start position:0% +okay so you can put a little radioactive +tracer on deoxyglucose + + align:start position:0% +tracer on deoxyglucose + + + align:start position:0% +tracer on deoxyglucose +inject it into a person or an animal and + + align:start position:0% +inject it into a person or an animal and + + + align:start position:0% +inject it into a person or an animal and +what happens is it builds up with this + + align:start position:0% +what happens is it builds up with this + + + align:start position:0% +what happens is it builds up with this +radioactive tag on all the cells that + + align:start position:0% +radioactive tag on all the cells that + + + align:start position:0% +radioactive tag on all the cells that +were active makes sense + + align:start position:0% +were active makes sense + + + align:start position:0% +were active makes sense +okay so tutel did an experiment where + + align:start position:0% +okay so tutel did an experiment where + + + align:start position:0% +okay so tutel did an experiment where +he had the monkey fixate on a spot + + align:start position:0% +he had the monkey fixate on a spot + + + align:start position:0% +he had the monkey fixate on a spot +and he presented this stimulus here so + + align:start position:0% +and he presented this stimulus here so + + + align:start position:0% +and he presented this stimulus here so +the monkey's fixating right there and + + align:start position:0% +the monkey's fixating right there and + + + align:start position:0% +the monkey's fixating right there and +the stimulus is flashing on and off + + align:start position:0% +the stimulus is flashing on and off + + + align:start position:0% +the stimulus is flashing on and off +he injects the radioactive deoxyglucose + + align:start position:0% +he injects the radioactive deoxyglucose + + + align:start position:0% +he injects the radioactive deoxyglucose +into the monkey while the monkey's + + align:start position:0% +into the monkey while the monkey's + + + align:start position:0% +into the monkey while the monkey's +looking at this + + align:start position:0% +looking at this + + + align:start position:0% +looking at this +and then i'm sorry to say he killed the + + align:start position:0% +and then i'm sorry to say he killed the + + + align:start position:0% +and then i'm sorry to say he killed the +monkey + + align:start position:0% +monkey + + + align:start position:0% +monkey +rolled out visual cortex into a sheet + + align:start position:0% +rolled out visual cortex into a sheet + + + align:start position:0% +rolled out visual cortex into a sheet +and there it is + + align:start position:0% +and there it is + + + align:start position:0% +and there it is +and you can see the bullseye pattern + + align:start position:0% +and you can see the bullseye pattern + + + align:start position:0% +and you can see the bullseye pattern +that the monkey was looking at across + + align:start position:0% +that the monkey was looking at across + + + align:start position:0% +that the monkey was looking at across +the surface of visual cortex + + align:start position:0% +the surface of visual cortex + + + align:start position:0% +the surface of visual cortex +does everybody get that + + align:start position:0% +does everybody get that + + + align:start position:0% +does everybody get that +okay so that shows you very literally + + align:start position:0% +okay so that shows you very literally + + + align:start position:0% +okay so that shows you very literally +what a retinotopic map is in the brain + + align:start position:0% +what a retinotopic map is in the brain + + + align:start position:0% +what a retinotopic map is in the brain +it's just like the map of the visual + + align:start position:0% +it's just like the map of the visual + + + align:start position:0% +it's just like the map of the visual +world in the retina but there it is up + + align:start position:0% +world in the retina but there it is up + + + align:start position:0% +world in the retina but there it is up +in the back of the brain and humans have + + align:start position:0% +in the back of the brain and humans have + + + align:start position:0% +in the back of the brain and humans have +this too + + align:start position:0% +this too + + + align:start position:0% +this too +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and so this can be shown in humans with + + align:start position:0% +and so this can be shown in humans with + + + align:start position:0% +and so this can be shown in humans with +functional mri we'll talk later more + + align:start position:0% +functional mri we'll talk later more + + + align:start position:0% +functional mri we'll talk later more +about the methods of functional mri but + + align:start position:0% +about the methods of functional mri but + + + align:start position:0% +about the methods of functional mri but +here's a very high resolution functional + + align:start position:0% +here's a very high resolution functional + + + align:start position:0% +here's a very high resolution functional +mri experiment done by some people over + + align:start position:0% +mri experiment done by some people over + + + align:start position:0% +mri experiment done by some people over +at mgh charlestown by the way when i + + align:start position:0% +at mgh charlestown by the way when i + + + align:start position:0% +at mgh charlestown by the way when i +have names on slides + + align:start position:0% +have names on slides + + + align:start position:0% +have names on slides +it's just because in science we don't + + align:start position:0% +it's just because in science we don't + + + align:start position:0% +it's just because in science we don't +get paid that much and so our credit for + + align:start position:0% +get paid that much and so our credit for + + + align:start position:0% +get paid that much and so our credit for +our cool data is kind of all we have and + + align:start position:0% +our cool data is kind of all we have and + + + align:start position:0% +our cool data is kind of all we have and +so i can't stand to talk about other + + align:start position:0% +so i can't stand to talk about other + + + align:start position:0% +so i can't stand to talk about other +people's cool experiments without giving + + align:start position:0% +people's cool experiments without giving + + + align:start position:0% +people's cool experiments without giving +them credit i do not expect you to learn + + align:start position:0% +them credit i do not expect you to learn + + + align:start position:0% +them credit i do not expect you to learn +the names it's just my little personal + + align:start position:0% +the names it's just my little personal + + + align:start position:0% +the names it's just my little personal +tic that i need to have their name there + + align:start position:0% +tic that i need to have their name there + + + align:start position:0% +tic that i need to have their name there +to give them credit even though you + + align:start position:0% +to give them credit even though you + + + align:start position:0% +to give them credit even though you +don't know who they are okay + + align:start position:0% +don't know who they are okay + + + align:start position:0% +don't know who they are okay +okay so what this guy john palomani did + + align:start position:0% +okay so what this guy john palomani did + + + align:start position:0% +okay so what this guy john palomani did +was show human subjects this stimulus + + align:start position:0% +was show human subjects this stimulus + + + align:start position:0% +was show human subjects this stimulus +here they were fixating right there and + + align:start position:0% +here they were fixating right there and + + + align:start position:0% +here they were fixating right there and +the stimulus is flickering with the dots + + align:start position:0% +the stimulus is flickering with the dots + + + align:start position:0% +the stimulus is flickering with the dots +kind of dancing around + + align:start position:0% +kind of dancing around + + + align:start position:0% +kind of dancing around +and then he looked on the back in visual + + align:start position:0% +and then he looked on the back in visual + + + align:start position:0% +and then he looked on the back in visual +cortex on the surface of the brain + + align:start position:0% +cortex on the surface of the brain + + + align:start position:0% +cortex on the surface of the brain +and he sees an n there + + align:start position:0% +and he sees an n there + + + align:start position:0% +and he sees an n there +it's the same stimulus it's just flipped + + align:start position:0% +it's the same stimulus it's just flipped + + + align:start position:0% +it's the same stimulus it's just flipped +upside down which is not deeper + + align:start position:0% +upside down which is not deeper + + + align:start position:0% +upside down which is not deeper +interesting the cortex has to be + + align:start position:0% +interesting the cortex has to be + + + align:start position:0% +interesting the cortex has to be +oriented one way or another the brain + + align:start position:0% +oriented one way or another the brain + + + align:start position:0% +oriented one way or another the brain +doesn't care whether you turn it around + + align:start position:0% +doesn't care whether you turn it around + + + align:start position:0% +doesn't care whether you turn it around +right and your map of visual space is + + align:start position:0% +right and your map of visual space is + + + align:start position:0% +right and your map of visual space is +upside down in the back of the head + + align:start position:0% +upside down in the back of the head + + + align:start position:0% +upside down in the back of the head +and you see that m + + align:start position:0% +and you see that m + + + align:start position:0% +and you see that m +does everybody get how that also shows + + align:start position:0% +does everybody get how that also shows + + + align:start position:0% +does everybody get how that also shows +retinotopic properties in the brain + + align:start position:0% +retinotopic properties in the brain + + + align:start position:0% +retinotopic properties in the brain +in human visual cortex + + align:start position:0% +in human visual cortex + + + align:start position:0% +in human visual cortex +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right so the key idea of retina + + align:start position:0% +all right so the key idea of retina + + + align:start position:0% +all right so the key idea of retina +toppy is that adjacent parts of the + + align:start position:0% +toppy is that adjacent parts of the + + + align:start position:0% +toppy is that adjacent parts of the +visual seal field are mapped to adjacent + + align:start position:0% +visual seal field are mapped to adjacent + + + align:start position:0% +visual seal field are mapped to adjacent +parts of the cortex + + align:start position:0% +parts of the cortex + + + align:start position:0% +parts of the cortex +all right + + align:start position:0% +all right + + + align:start position:0% +all right +okay a little bit of terminology just + + align:start position:0% +okay a little bit of terminology just + + + align:start position:0% +okay a little bit of terminology just +because + + align:start position:0% +because + + + align:start position:0% +because +people are fast and loose with these + + align:start position:0% +people are fast and loose with these + + + align:start position:0% +people are fast and loose with these +things i've already referred to v1 and + + align:start position:0% +things i've already referred to v1 and + + + align:start position:0% +things i've already referred to v1 and +primary visual cortex it's also + + align:start position:0% +primary visual cortex it's also + + + align:start position:0% +primary visual cortex it's also +sometimes called striat cortex it's all + + align:start position:0% +sometimes called striat cortex it's all + + + align:start position:0% +sometimes called striat cortex it's all +the same thing it's the part of the + + align:start position:0% +the same thing it's the part of the + + + align:start position:0% +the same thing it's the part of the +visual cortex where the information + + align:start position:0% +visual cortex where the information + + + align:start position:0% +visual cortex where the information +first comes up from the lgn right back + + align:start position:0% +first comes up from the lgn right back + + + align:start position:0% +first comes up from the lgn right back +here + + align:start position:0% +here + + + align:start position:0% +here +so in me it's right there most of it is + + align:start position:0% +so in me it's right there most of it is + + + align:start position:0% +so in me it's right there most of it is +in the space between the two hemispheres + + align:start position:0% +in the space between the two hemispheres + + + align:start position:0% +in the space between the two hemispheres +but a little bit sticks out on the side + + align:start position:0% +but a little bit sticks out on the side + + + align:start position:0% +but a little bit sticks out on the side +so in this person that yellowy orange + + align:start position:0% +so in this person that yellowy orange + + + align:start position:0% +so in this person that yellowy orange +stuff that's primary visual cortex which + + align:start position:0% +stuff that's primary visual cortex which + + + align:start position:0% +stuff that's primary visual cortex which +is the same as v1 and striat cortex okay + + align:start position:0% +is the same as v1 and striat cortex okay + + + align:start position:0% +is the same as v1 and striat cortex okay +that's just terminology + + align:start position:0% +that's just terminology + + + align:start position:0% +that's just terminology +all right just as we have maps for + + align:start position:0% +all right just as we have maps for + + + align:start position:0% +all right just as we have maps for +visual space we have maps for touch + + align:start position:0% +visual space we have maps for touch + + + align:start position:0% +visual space we have maps for touch +space and so you've probably seen this + + align:start position:0% +space and so you've probably seen this + + + align:start position:0% +space and so you've probably seen this +diagram here of the map of touch space + + align:start position:0% +diagram here of the map of touch space + + + align:start position:0% +diagram here of the map of touch space +going across somatosensory cortex like + + align:start position:0% +going across somatosensory cortex like + + + align:start position:0% +going across somatosensory cortex like +this so this is a picture of a slice + + align:start position:0% +this so this is a picture of a slice + + + align:start position:0% +this so this is a picture of a slice +like that showing you which parts of the + + align:start position:0% +like that showing you which parts of the + + + align:start position:0% +like that showing you which parts of the +body are mapped out to which parts of + + align:start position:0% +body are mapped out to which parts of + + + align:start position:0% +body are mapped out to which parts of +space + + align:start position:0% +space + + + align:start position:0% +space +and you can see that particularly + + align:start position:0% +and you can see that particularly + + + align:start position:0% +and you can see that particularly +important parts of the body get bigger + + align:start position:0% +important parts of the body get bigger + + + align:start position:0% +important parts of the body get bigger +bits of cortex + + align:start position:0% +bits of cortex + + + align:start position:0% +bits of cortex +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +okay + + align:start position:0% +okay + + + align:start position:0% +okay +just as we have visual maps and touch + + align:start position:0% +just as we have visual maps and touch + + + align:start position:0% +just as we have visual maps and touch +maps we have auditory maps in auditory + + align:start position:0% +maps we have auditory maps in auditory + + + align:start position:0% +maps we have auditory maps in auditory +cortex which is right on the top of the + + align:start position:0% +cortex which is right on the top of the + + + align:start position:0% +cortex which is right on the top of the +temporal lobe right in here + + align:start position:0% +temporal lobe right in here + + + align:start position:0% +temporal lobe right in here +and which is what's mapped out in + + align:start position:0% +and which is what's mapped out in + + + align:start position:0% +and which is what's mapped out in +auditory cortex is auditory frequency + + align:start position:0% +auditory cortex is auditory frequency + + + align:start position:0% +auditory cortex is auditory frequency +high versus low versus high + + align:start position:0% +high versus low versus high + + + align:start position:0% +high versus low versus high +frequencies of sound and so you see that + + align:start position:0% +frequencies of sound and so you see that + + + align:start position:0% +frequencies of sound and so you see that +here's a piece of auditory cortex in one + + align:start position:0% +here's a piece of auditory cortex in one + + + align:start position:0% +here's a piece of auditory cortex in one +subject showing you + + align:start position:0% +subject showing you + + + align:start position:0% +subject showing you +regions that respond to high frequencies + + align:start position:0% +regions that respond to high frequencies + + + align:start position:0% +regions that respond to high frequencies +low frequencies high frequencies here it + + align:start position:0% +low frequencies high frequencies here it + + + align:start position:0% +low frequencies high frequencies here it +is another subject high low high another + + align:start position:0% +is another subject high low high another + + + align:start position:0% +is another subject high low high another +subject high low high + + align:start position:0% +subject high low high + + + align:start position:0% +subject high low high +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so the point of all of this + + align:start position:0% +so the point of all of this + + + align:start position:0% +so the point of all of this +is that primary sensory cortex has maps + + align:start position:0% +is that primary sensory cortex has maps + + + align:start position:0% +is that primary sensory cortex has maps +everybody clear on this the different + + align:start position:0% +everybody clear on this the different + + + align:start position:0% +everybody clear on this the different +sensory modalities map different + + align:start position:0% +sensory modalities map different + + + align:start position:0% +sensory modalities map different +dimensions + + align:start position:0% +dimensions + + + align:start position:0% +dimensions +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so what about the rest of cortex like + + align:start position:0% +so what about the rest of cortex like + + + align:start position:0% +so what about the rest of cortex like +you can see most of the cortex is not + + align:start position:0% +you can see most of the cortex is not + + + align:start position:0% +you can see most of the cortex is not +primary sensory cortex + + align:start position:0% +primary sensory cortex + + + align:start position:0% +primary sensory cortex +is the rest of cortex just mush or are + + align:start position:0% +is the rest of cortex just mush or are + + + align:start position:0% +is the rest of cortex just mush or are +there separate bits like primary sensory + + align:start position:0% +there separate bits like primary sensory + + + align:start position:0% +there separate bits like primary sensory +areas + + align:start position:0% + + + + align:start position:0% + +and if so do those other bits have maps + + align:start position:0% +and if so do those other bits have maps + + + align:start position:0% +and if so do those other bits have maps +and if so + + align:start position:0% +and if so + + + align:start position:0% +and if so +what are those maps of + + align:start position:0% +what are those maps of + + + align:start position:0% +what are those maps of +okay we just took you from 100 years ago + + align:start position:0% +okay we just took you from 100 years ago + + + align:start position:0% +okay we just took you from 100 years ago +to the cutting edge of the field is + + align:start position:0% +to the cutting edge of the field is + + + align:start position:0% +to the cutting edge of the field is +asking this question in lots of + + align:start position:0% +asking this question in lots of + + + align:start position:0% +asking this question in lots of +different ways right now + + align:start position:0% +different ways right now + + + align:start position:0% +different ways right now +okay + + align:start position:0% + + + + align:start position:0% + +okay let's back up and ask what counts + + align:start position:0% +okay let's back up and ask what counts + + + align:start position:0% +okay let's back up and ask what counts +as a cortical area anyway i just posited + + align:start position:0% +as a cortical area anyway i just posited + + + align:start position:0% +as a cortical area anyway i just posited +that these primary sensory regions count + + align:start position:0% +that these primary sensory regions count + + + align:start position:0% +that these primary sensory regions count +as distinct things they're like the + + align:start position:0% +as distinct things they're like the + + + align:start position:0% +as distinct things they're like the +things right they're separate things in + + align:start position:0% +things right they're separate things in + + + align:start position:0% +things right they're separate things in +the brain okay and if for no other + + align:start position:0% +the brain okay and if for no other + + + align:start position:0% +the brain okay and if for no other +reason then they get direct input from + + align:start position:0% +reason then they get direct input from + + + align:start position:0% +reason then they get direct input from +the thalamus + + align:start position:0% +the thalamus + + + align:start position:0% +the thalamus +right + + align:start position:0% +right + + + align:start position:0% +right +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +but let's back up and ask what exactly + + align:start position:0% +but let's back up and ask what exactly + + + align:start position:0% +but let's back up and ask what exactly +is a cortical area + + align:start position:0% +is a cortical area + + + align:start position:0% +is a cortical area +and we're going to consider this + + align:start position:0% +and we're going to consider this + + + align:start position:0% +and we're going to consider this +question + + align:start position:0% +question + + + align:start position:0% +question +um + + align:start position:0% +um + + + align:start position:0% +um +by considering the three key criteria + + align:start position:0% +by considering the three key criteria + + + align:start position:0% +by considering the three key criteria +for what counts as a cortical area + + align:start position:0% +for what counts as a cortical area + + + align:start position:0% +for what counts as a cortical area +okay the first one + + align:start position:0% +okay the first one + + + align:start position:0% +okay the first one +is that that region of cortex is + + align:start position:0% +is that that region of cortex is + + + align:start position:0% +is that that region of cortex is +distinct from its neighbors in function + + align:start position:0% +distinct from its neighbors in function + + + align:start position:0% +distinct from its neighbors in function +neurons their fire in response to + + align:start position:0% +neurons their fire in response to + + + align:start position:0% +neurons their fire in response to +something different from the neurons in + + align:start position:0% +something different from the neurons in + + + align:start position:0% +something different from the neurons in +the neighboring region okay that's very + + align:start position:0% +the neighboring region okay that's very + + + align:start position:0% +the neighboring region okay that's very +vague right now but we'll illustrate + + align:start position:0% +vague right now but we'll illustrate + + + align:start position:0% +vague right now but we'll illustrate +that + + align:start position:0% +that + + + align:start position:0% +that +the next one as i mentioned this before + + align:start position:0% +the next one as i mentioned this before + + + align:start position:0% +the next one as i mentioned this before +each distinct + + align:start position:0% +each distinct + + + align:start position:0% +each distinct +region of cortex has a different set of + + align:start position:0% +region of cortex has a different set of + + + align:start position:0% +region of cortex has a different set of +connections to other parts of the brain + + align:start position:0% +connections to other parts of the brain + + + align:start position:0% +connections to other parts of the brain +it has a distinct connectivity + + align:start position:0% +it has a distinct connectivity + + + align:start position:0% +it has a distinct connectivity +fingerprint + + align:start position:0% +fingerprint + + + align:start position:0% +fingerprint +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and the third thing is + + align:start position:0% +and the third thing is + + + align:start position:0% +and the third thing is +for at least some regions of the cortex + + align:start position:0% +for at least some regions of the cortex + + + align:start position:0% +for at least some regions of the cortex +they're physically different if you + + align:start position:0% +they're physically different if you + + + align:start position:0% +they're physically different if you +slice them up and stain them and look at + + align:start position:0% +slice them up and stain them and look at + + + align:start position:0% +slice them up and stain them and look at +them really carefully they might look a + + align:start position:0% +them really carefully they might look a + + + align:start position:0% +them really carefully they might look a +little different than other bits of the + + align:start position:0% +little different than other bits of the + + + align:start position:0% +little different than other bits of the +cortex + + align:start position:0% +cortex + + + align:start position:0% +cortex +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so those are three of the key criteria + + align:start position:0% +so those are three of the key criteria + + + align:start position:0% +so those are three of the key criteria +that have been used to say this bit of + + align:start position:0% +that have been used to say this bit of + + + align:start position:0% +that have been used to say this bit of +cortex it's a thing right it's distinct + + align:start position:0% +cortex it's a thing right it's distinct + + + align:start position:0% +cortex it's a thing right it's distinct +right + + align:start position:0% +right + + + align:start position:0% +right +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so let's look at the classic example + + align:start position:0% +so let's look at the classic example + + + align:start position:0% +so let's look at the classic example +beyond those primary regions those are + + align:start position:0% +beyond those primary regions those are + + + align:start position:0% +beyond those primary regions those are +the most classic regions the primary + + align:start position:0% +the most classic regions the primary + + + align:start position:0% +the most classic regions the primary +regions we've already talked about those + + align:start position:0% +regions we've already talked about those + + + align:start position:0% +regions we've already talked about those +are the ones nobody would fight you on + + align:start position:0% +are the ones nobody would fight you on + + + align:start position:0% +are the ones nobody would fight you on +that this one is next in line nobody + + align:start position:0% +that this one is next in line nobody + + + align:start position:0% +that this one is next in line nobody +will fight you of say if you say visual + + align:start position:0% +will fight you of say if you say visual + + + align:start position:0% +will fight you of say if you say visual +area mt + + align:start position:0% +area mt + + + align:start position:0% +area mt +that's an area well they might but most + + align:start position:0% +that's an area well they might but most + + + align:start position:0% +that's an area well they might but most +people wouldn't okay and then from there + + align:start position:0% +people wouldn't okay and then from there + + + align:start position:0% +people wouldn't okay and then from there +on out it's all fighting all the time + + align:start position:0% +on out it's all fighting all the time + + + align:start position:0% +on out it's all fighting all the time +okay so let's talk about visual area mt + + align:start position:0% +okay so let's talk about visual area mt + + + align:start position:0% +okay so let's talk about visual area mt +it's a little patch of the cortex and a + + align:start position:0% +it's a little patch of the cortex and a + + + align:start position:0% +it's a little patch of the cortex and a +monkey brain this is a side view of a + + align:start position:0% +monkey brain this is a side view of a + + + align:start position:0% +monkey brain this is a side view of a +monkey brain + + align:start position:0% +monkey brain + + + align:start position:0% +monkey brain +and in this human brain it's that little + + align:start position:0% +and in this human brain it's that little + + + align:start position:0% +and in this human brain it's that little +patch right there + + align:start position:0% +patch right there + + + align:start position:0% +patch right there +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +this region meets all the criteria to be + + align:start position:0% +this region meets all the criteria to be + + + align:start position:0% +this region meets all the criteria to be +a distinct visual area + + align:start position:0% +a distinct visual area + + + align:start position:0% +a distinct visual area +so how do we know this + + align:start position:0% +so how do we know this + + + align:start position:0% +so how do we know this +well we know this from lots and lots of + + align:start position:0% +well we know this from lots and lots of + + + align:start position:0% +well we know this from lots and lots of +different methods so i'm going to whip + + align:start position:0% +different methods so i'm going to whip + + + align:start position:0% +different methods so i'm going to whip +through a few of those to give you a + + align:start position:0% +through a few of those to give you a + + + align:start position:0% +through a few of those to give you a +gist of how we can find evidence that + + align:start position:0% +gist of how we can find evidence that + + + align:start position:0% +gist of how we can find evidence that +that region is distinct in function + + align:start position:0% +that region is distinct in function + + + align:start position:0% +that region is distinct in function +connectivity and + + align:start position:0% +connectivity and + + + align:start position:0% +connectivity and +the physical stuff sometimes called cyto + + align:start position:0% +the physical stuff sometimes called cyto + + + align:start position:0% +the physical stuff sometimes called cyto +architecture + + align:start position:0% +architecture + + + align:start position:0% +architecture +okay + + align:start position:0% +okay + + + align:start position:0% +okay +all right + + align:start position:0% +all right + + + align:start position:0% +all right +function how would we know that region + + align:start position:0% +function how would we know that region + + + align:start position:0% +function how would we know that region +respon has a different function + + align:start position:0% +respon has a different function + + + align:start position:0% +respon has a different function +well one way the classic way is to + + align:start position:0% +well one way the classic way is to + + + align:start position:0% +well one way the classic way is to +record from individual neurons in monkey + + align:start position:0% +record from individual neurons in monkey + + + align:start position:0% +record from individual neurons in monkey +brains + + align:start position:0% +brains + + + align:start position:0% +brains +so if you stick a neuron into monkey + + align:start position:0% +so if you stick a neuron into monkey + + + align:start position:0% +so if you stick a neuron into monkey +visual cortex while the monkey is + + align:start position:0% +visual cortex while the monkey is + + + align:start position:0% +visual cortex while the monkey is +looking at the stimulus + + align:start position:0% +looking at the stimulus + + + align:start position:0% +looking at the stimulus +that i'll show you in a second you'll + + align:start position:0% +that i'll show you in a second you'll + + + align:start position:0% +that i'll show you in a second you'll +hear the responses of an individual + + align:start position:0% +hear the responses of an individual + + + align:start position:0% +hear the responses of an individual +neuron each clique will be the response + + align:start position:0% +neuron each clique will be the response + + + align:start position:0% +neuron each clique will be the response +of an individual neuron to the stimulus + + align:start position:0% +of an individual neuron to the stimulus + + + align:start position:0% +of an individual neuron to the stimulus +so let's play this thing + + align:start position:0% +so let's play this thing + + + align:start position:0% +so let's play this thing +except it's not making any sound chris + + align:start position:0% +except it's not making any sound chris + + + align:start position:0% +except it's not making any sound chris +can you help me + + align:start position:0% + + + + align:start position:0% + +oh right + + align:start position:0% +oh right + + + align:start position:0% +oh right +duh + + align:start position:0% + + + + align:start position:0% + +that part + + align:start position:0% +that part + + + align:start position:0% +that part +okay see when the bar of light moves + + align:start position:0% +okay see when the bar of light moves + + + align:start position:0% +okay see when the bar of light moves +this way it makes a lot of firing + + align:start position:0% +this way it makes a lot of firing + + + align:start position:0% +this way it makes a lot of firing +and not when it moves the other way + + align:start position:0% +and not when it moves the other way + + + align:start position:0% +and not when it moves the other way +let's watch it for a second watch the + + align:start position:0% +let's watch it for a second watch the + + + align:start position:0% +let's watch it for a second watch the +bar move again + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +so he responds less when it's moving in + + align:start position:0% +so he responds less when it's moving in + + + align:start position:0% +so he responds less when it's moving in +a different direction ready got that + + align:start position:0% + + + + align:start position:0% + +what is this area right there called + + align:start position:0% + + + + align:start position:0% + +yeah this area right here in the middle + + align:start position:0% + + + + align:start position:0% + +exactly that's a receptive field that's + + align:start position:0% +exactly that's a receptive field that's + + + align:start position:0% +exactly that's a receptive field that's +a part of visual space that makes this + + align:start position:0% +a part of visual space that makes this + + + align:start position:0% +a part of visual space that makes this +neuron fire + + align:start position:0% + + + + align:start position:0% + +okay this neuron also has a property + + align:start position:0% +okay this neuron also has a property + + + align:start position:0% +okay this neuron also has a property +called direction it's sensitive to + + align:start position:0% +called direction it's sensitive to + + + align:start position:0% +called direction it's sensitive to +motion as you see but it's also + + align:start position:0% +motion as you see but it's also + + + align:start position:0% +motion as you see but it's also +specific to specific directions of + + align:start position:0% +specific to specific directions of + + + align:start position:0% +specific to specific directions of +motion everybody see that + + align:start position:0% +motion everybody see that + + + align:start position:0% +motion everybody see that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that's a direction selective neuron + + align:start position:0% +so that's a direction selective neuron + + + align:start position:0% +so that's a direction selective neuron +in monkey area mt + + align:start position:0% +in monkey area mt + + + align:start position:0% +in monkey area mt +and here's a way of showing with data + + align:start position:0% +and here's a way of showing with data + + + align:start position:0% +and here's a way of showing with data +what you guys just saw + + align:start position:0% +what you guys just saw + + + align:start position:0% +what you guys just saw +this is a map of different directions in + + align:start position:0% +this is a map of different directions in + + + align:start position:0% +this is a map of different directions in +polar coordinates and this shows you how + + align:start position:0% +polar coordinates and this shows you how + + + align:start position:0% +polar coordinates and this shows you how +much + + align:start position:0% +much + + + align:start position:0% +much +this is a this is a single cell being + + align:start position:0% +this is a this is a single cell being + + + align:start position:0% +this is a this is a single cell being +described here this is the direction + + align:start position:0% +described here this is the direction + + + align:start position:0% +described here this is the direction +selectivity of that cell showing you + + align:start position:0% +selectivity of that cell showing you + + + align:start position:0% +selectivity of that cell showing you +that when motion moves when the stimulus + + align:start position:0% +that when motion moves when the stimulus + + + align:start position:0% +that when motion moves when the stimulus +moves in this direction you get a lot of + + align:start position:0% +moves in this direction you get a lot of + + + align:start position:0% +moves in this direction you get a lot of +firing when it moves in this direction + + align:start position:0% +firing when it moves in this direction + + + align:start position:0% +firing when it moves in this direction +you get less firing and can everybody + + align:start position:0% +you get less firing and can everybody + + + align:start position:0% +you get less firing and can everybody +see how this plot shows you the + + align:start position:0% +see how this plot shows you the + + + align:start position:0% +see how this plot shows you the +direction selectivity of that cell makes + + align:start position:0% +direction selectivity of that cell makes + + + align:start position:0% +direction selectivity of that cell makes +sense + + align:start position:0% +sense + + + align:start position:0% +sense +right + + align:start position:0% +right + + + align:start position:0% +right +okay so that shows you what you just saw + + align:start position:0% +okay so that shows you what you just saw + + + align:start position:0% +okay so that shows you what you just saw +in the movie + + align:start position:0% +in the movie + + + align:start position:0% +in the movie +so this is one way to establish the + + align:start position:0% +so this is one way to establish the + + + align:start position:0% +so this is one way to establish the +function + + align:start position:0% +function + + + align:start position:0% +function +of visual area mt is stick electrodes in + + align:start position:0% +of visual area mt is stick electrodes in + + + align:start position:0% +of visual area mt is stick electrodes in +there and record directly from them + + align:start position:0% +there and record directly from them + + + align:start position:0% +there and record directly from them +when a monkey looks at different kinds + + align:start position:0% +when a monkey looks at different kinds + + + align:start position:0% +when a monkey looks at different kinds +of stimuli and you see direction + + align:start position:0% +of stimuli and you see direction + + + align:start position:0% +of stimuli and you see direction +selectivity when you do that + + align:start position:0% +selectivity when you do that + + + align:start position:0% +selectivity when you do that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +further + + align:start position:0% +further + + + align:start position:0% +further +if you actually do this systematically + + align:start position:0% +if you actually do this systematically + + + align:start position:0% +if you actually do this systematically +moving across next door bits + + align:start position:0% +moving across next door bits + + + align:start position:0% +moving across next door bits +of + + align:start position:0% +of + + + align:start position:0% +of +monkey area mt + + align:start position:0% +monkey area mt + + + align:start position:0% +monkey area mt +what you find is that as we said before + + align:start position:0% +what you find is that as we said before + + + align:start position:0% +what you find is that as we said before +nearby bits of cortex respond to similar + + align:start position:0% +nearby bits of cortex respond to similar + + + align:start position:0% +nearby bits of cortex respond to similar +things in this case to similar + + align:start position:0% +things in this case to similar + + + align:start position:0% +things in this case to similar +directions of motion so here's a little + + align:start position:0% +directions of motion so here's a little + + + align:start position:0% +directions of motion so here's a little +diagram as you move across the cortex + + align:start position:0% +diagram as you move across the cortex + + + align:start position:0% +diagram as you move across the cortex +you see a systematic change in the + + align:start position:0% +you see a systematic change in the + + + align:start position:0% +you see a systematic change in the +direction selectivity of neurons as you + + align:start position:0% +direction selectivity of neurons as you + + + align:start position:0% +direction selectivity of neurons as you +move across the cortex + + align:start position:0% +move across the cortex + + + align:start position:0% +move across the cortex +so in mt + + align:start position:0% +so in mt + + + align:start position:0% +so in mt +we have a map of direction preference + + align:start position:0% +we have a map of direction preference + + + align:start position:0% +we have a map of direction preference +just as we had a map of + + align:start position:0% +just as we had a map of + + + align:start position:0% +just as we had a map of +spatial location in primary visual + + align:start position:0% +spatial location in primary visual + + + align:start position:0% +spatial location in primary visual +cortex make sense + + align:start position:0% +cortex make sense + + + align:start position:0% +cortex make sense +okay now because those neurons are + + align:start position:0% +okay now because those neurons are + + + align:start position:0% +okay now because those neurons are +clustered like that + + align:start position:0% +clustered like that + + + align:start position:0% +clustered like that +i forget what my next point was no never + + align:start position:0% +i forget what my next point was no never + + + align:start position:0% +i forget what my next point was no never +mind we'll get that in a second okay + + align:start position:0% +mind we'll get that in a second okay + + + align:start position:0% +mind we'll get that in a second okay +what about humans okay so here's a + + align:start position:0% +what about humans okay so here's a + + + align:start position:0% +what about humans okay so here's a +monkey brain here's a neuron and a + + align:start position:0% +monkey brain here's a neuron and a + + + align:start position:0% +monkey brain here's a neuron and a +monkey brain what about humans can we + + align:start position:0% +monkey brain what about humans can we + + + align:start position:0% +monkey brain what about humans can we +record from single neurons in humans + + align:start position:0% +record from single neurons in humans + + + align:start position:0% +record from single neurons in humans +what do you think + + align:start position:0% + + + + align:start position:0% + +do we ever get to do that + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% + + + + align:start position:0% + +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +neurosurgeons very occasionally enable + + align:start position:0% +neurosurgeons very occasionally enable + + + align:start position:0% +neurosurgeons very occasionally enable +us to record from individual neurons in + + align:start position:0% +us to record from individual neurons in + + + align:start position:0% +us to record from individual neurons in +human brains it's the most awesome data + + align:start position:0% +human brains it's the most awesome data + + + align:start position:0% +human brains it's the most awesome data +ever + + align:start position:0% +ever + + + align:start position:0% +ever +of course we only do it when the + + align:start position:0% +of course we only do it when the + + + align:start position:0% +of course we only do it when the +neurosurgeons have decided for clinical + + align:start position:0% +neurosurgeons have decided for clinical + + + align:start position:0% +neurosurgeons have decided for clinical +reasons to put electrodes in human + + align:start position:0% +reasons to put electrodes in human + + + align:start position:0% +reasons to put electrodes in human +brains they need to do this to map out + + align:start position:0% +brains they need to do this to map out + + + align:start position:0% +brains they need to do this to map out +epilepsy before surgery and sometimes + + align:start position:0% +epilepsy before surgery and sometimes + + + align:start position:0% +epilepsy before surgery and sometimes +those patients are super nice and say + + align:start position:0% +those patients are super nice and say + + + align:start position:0% +those patients are super nice and say +yes i'll look at your stimuli or listen + + align:start position:0% +yes i'll look at your stimuli or listen + + + align:start position:0% +yes i'll look at your stimuli or listen +to your stimuli while you record from my + + align:start position:0% +to your stimuli while you record from my + + + align:start position:0% +to your stimuli while you record from my +neurons and then we get the most awesome + + align:start position:0% +neurons and then we get the most awesome + + + align:start position:0% +neurons and then we get the most awesome +data ever but it's very very rare i + + align:start position:0% +data ever but it's very very rare i + + + align:start position:0% +data ever but it's very very rare i +don't know of any data where people have + + align:start position:0% +don't know of any data where people have + + + align:start position:0% +don't know of any data where people have +reported individual neurons in area mt + + align:start position:0% +reported individual neurons in area mt + + + align:start position:0% +reported individual neurons in area mt +in humans yeah so how powerful should an + + align:start position:0% +in humans yeah so how powerful should an + + + align:start position:0% +in humans yeah so how powerful should an +fmri be to be able to ignore such + + align:start position:0% +fmri be to be able to ignore such + + + align:start position:0% +fmri be to be able to ignore such +information oh we're getting there + + align:start position:0% +information oh we're getting there + + + align:start position:0% +information oh we're getting there +okay so given that we very rarely + + align:start position:0% +okay so given that we very rarely + + + align:start position:0% +okay so given that we very rarely +uh get uh get to record from individual + + align:start position:0% +uh get uh get to record from individual + + + align:start position:0% +uh get uh get to record from individual +neurons in humans and we want to know + + align:start position:0% +neurons in humans and we want to know + + + align:start position:0% +neurons in humans and we want to know +more generally + + align:start position:0% +more generally + + + align:start position:0% +more generally +if there is an mt in humans what do we + + align:start position:0% +if there is an mt in humans what do we + + + align:start position:0% +if there is an mt in humans what do we +do + + align:start position:0% +do + + + align:start position:0% +do +we pop subjects in an mri scanner + + align:start position:0% +we pop subjects in an mri scanner + + + align:start position:0% +we pop subjects in an mri scanner +and we show them moving dots or + + align:start position:0% +and we show them moving dots or + + + align:start position:0% +and we show them moving dots or +stationary dots + + align:start position:0% +stationary dots + + + align:start position:0% +stationary dots +and we scan them with functional mri + + align:start position:0% +and we scan them with functional mri + + + align:start position:0% +and we scan them with functional mri +we'll go through the details of how this + + align:start position:0% +we'll go through the details of how this + + + align:start position:0% +we'll go through the details of how this +works more in future lectures but what + + align:start position:0% +works more in future lectures but what + + + align:start position:0% +works more in future lectures but what +you see basically is this is a slice + + align:start position:0% +you see basically is this is a slice + + + align:start position:0% +you see basically is this is a slice +through the brain like this + + align:start position:0% +through the brain like this + + + align:start position:0% +through the brain like this +and you see this region right here + + align:start position:0% +and you see this region right here + + + align:start position:0% +and you see this region right here +responds more + + align:start position:0% +responds more + + + align:start position:0% +responds more +to the moving dots this is the response + + align:start position:0% +to the moving dots this is the response + + + align:start position:0% +to the moving dots this is the response +to the time here this is when the moving + + align:start position:0% +to the time here this is when the moving + + + align:start position:0% +to the time here this is when the moving +dots are on high response and then what + + align:start position:0% +dots are on high response and then what + + + align:start position:0% +dots are on high response and then what +switches to stationary dots + + align:start position:0% +switches to stationary dots + + + align:start position:0% +switches to stationary dots +the response drops + + align:start position:0% +the response drops + + + align:start position:0% +the response drops +okay so with functional mri you can also + + align:start position:0% +okay so with functional mri you can also + + + align:start position:0% +okay so with functional mri you can also +find visual area mt by the higher + + align:start position:0% +find visual area mt by the higher + + + align:start position:0% +find visual area mt by the higher +response to moving than stationary dots + + align:start position:0% +response to moving than stationary dots + + + align:start position:0% +response to moving than stationary dots +does that make sense more or less i mean + + align:start position:0% +does that make sense more or less i mean + + + align:start position:0% +does that make sense more or less i mean +i'm not giving you any of the details + + align:start position:0% +i'm not giving you any of the details + + + align:start position:0% +i'm not giving you any of the details +but for now they don't really matter + + align:start position:0% +but for now they don't really matter + + + align:start position:0% +but for now they don't really matter +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so that's cool + + align:start position:0% +so that's cool + + + align:start position:0% +so that's cool +but does that tell us + + align:start position:0% +but does that tell us + + + align:start position:0% +but does that tell us +that neurons in human mt are specific + + align:start position:0% +that neurons in human mt are specific + + + align:start position:0% +that neurons in human mt are specific +for the direction of motion + + align:start position:0% + + + + align:start position:0% + +yes + + align:start position:0% +yes + + + align:start position:0% +yes +moving in a specific motion removing in + + align:start position:0% +moving in a specific motion removing in + + + align:start position:0% +moving in a specific motion removing in +all the directions you see here + + align:start position:0% + + + + align:start position:0% + +no it doesn't + + align:start position:0% +no it doesn't + + + align:start position:0% +no it doesn't +it tells us it's sensitive to the + + align:start position:0% +it tells us it's sensitive to the + + + align:start position:0% +it tells us it's sensitive to the +presence of motion but not the direction + + align:start position:0% +presence of motion but not the direction + + + align:start position:0% +presence of motion but not the direction +of motion + + align:start position:0% +of motion + + + align:start position:0% +of motion +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so if if we want to really know is human + + align:start position:0% +so if if we want to really know is human + + + align:start position:0% +so if if we want to really know is human +mt like monkey empty or is this really + + align:start position:0% +mt like monkey empty or is this really + + + align:start position:0% +mt like monkey empty or is this really +human empty we want to know are the + + align:start position:0% +human empty we want to know are the + + + align:start position:0% +human empty we want to know are the +neurons in there not just responsive to + + align:start position:0% +neurons in there not just responsive to + + + align:start position:0% +neurons in there not just responsive to +motion but are neurons specific for + + align:start position:0% +motion but are neurons specific for + + + align:start position:0% +motion but are neurons specific for +particular directions of motion + + align:start position:0% +particular directions of motion + + + align:start position:0% +particular directions of motion +okay + + align:start position:0% +okay + + + align:start position:0% +okay +so + + align:start position:0% +so + + + align:start position:0% +so +how would we do that okay + + align:start position:0% +how would we do that okay + + + align:start position:0% +how would we do that okay +uh well there's lots of ways of doing + + align:start position:0% +uh well there's lots of ways of doing + + + align:start position:0% +uh well there's lots of ways of doing +that but actually one of the charming + + align:start position:0% +that but actually one of the charming + + + align:start position:0% +that but actually one of the charming +things is you can do that without an mri + + align:start position:0% +things is you can do that without an mri + + + align:start position:0% +things is you can do that without an mri +scanner that is it won't tell you + + align:start position:0% +scanner that is it won't tell you + + + align:start position:0% +scanner that is it won't tell you +whether it's empty you're looking at but + + align:start position:0% +whether it's empty you're looking at but + + + align:start position:0% +whether it's empty you're looking at but +we can ask the question of whether your + + align:start position:0% +we can ask the question of whether your + + + align:start position:0% +we can ask the question of whether your +brains have neurons that are tuned for + + align:start position:0% +brains have neurons that are tuned for + + + align:start position:0% +brains have neurons that are tuned for +particular directions + + align:start position:0% +particular directions + + + align:start position:0% +particular directions +so for this demo i want you to + + align:start position:0% +so for this demo i want you to + + + align:start position:0% +so for this demo i want you to +fixate right in the center and do not + + align:start position:0% +fixate right in the center and do not + + + align:start position:0% +fixate right in the center and do not +move your eyes from that dot + + align:start position:0% +move your eyes from that dot + + + align:start position:0% +move your eyes from that dot +and i'm going to keep talking for a + + align:start position:0% +and i'm going to keep talking for a + + + align:start position:0% +and i'm going to keep talking for a +while while you keep fixating right on + + align:start position:0% +while while you keep fixating right on + + + align:start position:0% +while while you keep fixating right on +that dot + + align:start position:0% +that dot + + + align:start position:0% +that dot +and so what we're going to what i'm + + align:start position:0% +and so what we're going to what i'm + + + align:start position:0% +and so what we're going to what i'm +going to show you is something called an + + align:start position:0% +going to show you is something called an + + + align:start position:0% +going to show you is something called an +after effect this is also known as the + + align:start position:0% +after effect this is also known as the + + + align:start position:0% +after effect this is also known as the +psychophysicist's electrode + + align:start position:0% +psychophysicist's electrode + + + align:start position:0% +psychophysicist's electrode +psychophysicists are people who just + + align:start position:0% +psychophysicists are people who just + + + align:start position:0% +psychophysicists are people who just +measure behavior and from behavior they + + align:start position:0% +measure behavior and from behavior they + + + align:start position:0% +measure behavior and from behavior they +can infer how individual neurons work + + align:start position:0% +can infer how individual neurons work + + + align:start position:0% +can infer how individual neurons work +and that is about as awesome as it gets + + align:start position:0% +and that is about as awesome as it gets + + + align:start position:0% +and that is about as awesome as it gets +that's much more impressive than just + + align:start position:0% +that's much more impressive than just + + + align:start position:0% +that's much more impressive than just +recording from the damn neuron inferring + + align:start position:0% +recording from the damn neuron inferring + + + align:start position:0% +recording from the damn neuron inferring +from very indirect data how the neuron + + align:start position:0% +from very indirect data how the neuron + + + align:start position:0% +from very indirect data how the neuron +works from behavior now that is pretty + + align:start position:0% +works from behavior now that is pretty + + + align:start position:0% +works from behavior now that is pretty +oops okay sorry look directly at my face + + align:start position:0% +oops okay sorry look directly at my face + + + align:start position:0% +oops okay sorry look directly at my face +you see anything i didn't see it stop oh + + align:start position:0% +you see anything i didn't see it stop oh + + + align:start position:0% +you see anything i didn't see it stop oh +crap we're gonna oh here we go + + align:start position:0% +crap we're gonna oh here we go + + + align:start position:0% +crap we're gonna oh here we go +uh oh right okay just fixate on the + + align:start position:0% +uh oh right okay just fixate on the + + + align:start position:0% +uh oh right okay just fixate on the +center again sorry i forgot this guy was + + align:start position:0% +center again sorry i forgot this guy was + + + align:start position:0% +center again sorry i forgot this guy was +going to stop + + align:start position:0% +going to stop + + + align:start position:0% +going to stop +so keep looking at the center + + align:start position:0% +so keep looking at the center + + + align:start position:0% +so keep looking at the center +and then when it stops in a little bit + + align:start position:0% +and then when it stops in a little bit + + + align:start position:0% +and then when it stops in a little bit +then keep your eyes right on that dot + + align:start position:0% +then keep your eyes right on that dot + + + align:start position:0% +then keep your eyes right on that dot +and you can see what happens + + align:start position:0% +and you can see what happens + + + align:start position:0% +and you can see what happens +oh that's right good point yes right now + + align:start position:0% +oh that's right good point yes right now + + + align:start position:0% +oh that's right good point yes right now +it's alternating nothing's gonna happen + + align:start position:0% +it's alternating nothing's gonna happen + + + align:start position:0% +it's alternating nothing's gonna happen +but that's okay we're gonna have the + + align:start position:0% +but that's okay we're gonna have the + + + align:start position:0% +but that's okay we're gonna have the +whole experience keep fixating on the + + align:start position:0% +whole experience keep fixating on the + + + align:start position:0% +whole experience keep fixating on the +dot + + align:start position:0% +dot + + + align:start position:0% +dot +it's good the tas are on the ball + + align:start position:0% +it's good the tas are on the ball + + + align:start position:0% +it's good the tas are on the ball +okay fix it on the dot + + align:start position:0% +okay fix it on the dot + + + align:start position:0% +okay fix it on the dot +anybody see anything + + align:start position:0% +anybody see anything + + + align:start position:0% +anybody see anything +not really + + align:start position:0% +not really + + + align:start position:0% +not really +that's okay you're not supposed to + + align:start position:0% +that's okay you're not supposed to + + + align:start position:0% +that's okay you're not supposed to +that's the control condition it was + + align:start position:0% +that's the control condition it was + + + align:start position:0% +that's the control condition it was +alternating directions okay so i think + + align:start position:0% +alternating directions okay so i think + + + align:start position:0% +alternating directions okay so i think +it's going to start moving again + + align:start position:0% +it's going to start moving again + + + align:start position:0% +it's going to start moving again +i'm not sure let's go back let's just + + align:start position:0% +i'm not sure let's go back let's just + + + align:start position:0% +i'm not sure let's go back let's just +start it again okay sorry i blew it the + + align:start position:0% +start it again okay sorry i blew it the + + + align:start position:0% +start it again okay sorry i blew it the +first time but let's just get this right + + align:start position:0% +first time but let's just get this right + + + align:start position:0% +first time but let's just get this right +okay fixate on the center + + align:start position:0% +okay fixate on the center + + + align:start position:0% +okay fixate on the center +and just keep your eyes right on that + + align:start position:0% +and just keep your eyes right on that + + + align:start position:0% +and just keep your eyes right on that +center + + align:start position:0% +center + + + align:start position:0% +center +so this one it's not alternating + + align:start position:0% +so this one it's not alternating + + + align:start position:0% +so this one it's not alternating +and it's going to do this for around 30 + + align:start position:0% +and it's going to do this for around 30 + + + align:start position:0% +and it's going to do this for around 30 +seconds + + align:start position:0% +seconds + + + align:start position:0% +seconds +and so the whole point of this is this + + align:start position:0% +and so the whole point of this is this + + + align:start position:0% +and so the whole point of this is this +is a way with behavior to ask the + + align:start position:0% +is a way with behavior to ask the + + + align:start position:0% +is a way with behavior to ask the +question of whether you have neurons in + + align:start position:0% +question of whether you have neurons in + + + align:start position:0% +question of whether you have neurons in +your brain tuned to specific directions + + align:start position:0% +your brain tuned to specific directions + + + align:start position:0% +your brain tuned to specific directions +of motion + + align:start position:0% +of motion + + + align:start position:0% +of motion +and something as low-tech and simple as + + align:start position:0% +and something as low-tech and simple as + + + align:start position:0% +and something as low-tech and simple as +an after effect can tell you that + + align:start position:0% + + + + align:start position:0% + +keep looking + + align:start position:0% + + + + align:start position:0% + +did you guys see anything + + align:start position:0% +did you guys see anything + + + align:start position:0% +did you guys see anything +what'd you see + + align:start position:0% +what'd you see + + + align:start position:0% +what'd you see +what happened + + align:start position:0% +what happened + + + align:start position:0% +what happened +it wasn't even exactly something they + + align:start position:0% +it wasn't even exactly something they + + + align:start position:0% +it wasn't even exactly something they +kind of like + + align:start position:0% + + + + align:start position:0% + +did it well it actually should + + align:start position:0% +did it well it actually should + + + align:start position:0% +did it well it actually should +well now it's doing something else but + + align:start position:0% +well now it's doing something else but + + + align:start position:0% +well now it's doing something else but +it should shrink at the end did you guys + + align:start position:0% +it should shrink at the end did you guys + + + align:start position:0% +it should shrink at the end did you guys +see it shrink + + align:start position:0% +see it shrink + + + align:start position:0% +see it shrink +okay so that's an after effect and the + + align:start position:0% +okay so that's an after effect and the + + + align:start position:0% +okay so that's an after effect and the +simple version of the story is that you + + align:start position:0% +simple version of the story is that you + + + align:start position:0% +simple version of the story is that you +are tiring out your neurons that are + + align:start position:0% +are tiring out your neurons that are + + + align:start position:0% +are tiring out your neurons that are +sensitive to outward motion while you + + align:start position:0% +sensitive to outward motion while you + + + align:start position:0% +sensitive to outward motion while you +stare at all that outward motion and + + align:start position:0% +stare at all that outward motion and + + + align:start position:0% +stare at all that outward motion and +after you kind of burn them out and + + align:start position:0% +after you kind of burn them out and + + + align:start position:0% +after you kind of burn them out and +exhaust them + + align:start position:0% +exhaust them + + + align:start position:0% +exhaust them +then when you look at something + + align:start position:0% +then when you look at something + + + align:start position:0% +then when you look at something +stationary it looks like it's going + + align:start position:0% +stationary it looks like it's going + + + align:start position:0% +stationary it looks like it's going +inward + + align:start position:0% +inward + + + align:start position:0% +inward +okay + + align:start position:0% +okay + + + align:start position:0% +okay +and the general idea is you have pools + + align:start position:0% +and the general idea is you have pools + + + align:start position:0% +and the general idea is you have pools +of neurons that the the easiest way to + + align:start position:0% +of neurons that the the easiest way to + + + align:start position:0% +of neurons that the the easiest way to +account for that is you have pools of + + align:start position:0% +account for that is you have pools of + + + align:start position:0% +account for that is you have pools of +neurons tuned for different directions + + align:start position:0% +neurons tuned for different directions + + + align:start position:0% +neurons tuned for different directions +and that's why if you tire out one batch + + align:start position:0% +and that's why if you tire out one batch + + + align:start position:0% +and that's why if you tire out one batch +you have a net signal in the other + + align:start position:0% +you have a net signal in the other + + + align:start position:0% +you have a net signal in the other +direction does that make sense + + align:start position:0% +direction does that make sense + + + align:start position:0% +direction does that make sense +this is all very relevant to your + + align:start position:0% +this is all very relevant to your + + + align:start position:0% +this is all very relevant to your +assignment which is due tomorrow night + + align:start position:0% +assignment which is due tomorrow night + + + align:start position:0% +assignment which is due tomorrow night +at 6. + + align:start position:0% +at 6. + + + align:start position:0% +at 6. +this phenomenon was used in the scanner + + align:start position:0% +this phenomenon was used in the scanner + + + align:start position:0% +this phenomenon was used in the scanner +for that experiment and you can think + + align:start position:0% +for that experiment and you can think + + + align:start position:0% +for that experiment and you can think +about + + align:start position:0% +about + + + align:start position:0% +about +um how you would use this phenomenon + + align:start position:0% +um how you would use this phenomenon + + + align:start position:0% +um how you would use this phenomenon +um to ask whether there's direction + + align:start position:0% +um to ask whether there's direction + + + align:start position:0% +um to ask whether there's direction +selectivity not just responses to motion + + align:start position:0% +selectivity not just responses to motion + + + align:start position:0% +selectivity not just responses to motion +in human mt + + align:start position:0% +in human mt + + + align:start position:0% +in human mt +yeah wait uh i'm just a little bit + + align:start position:0% +yeah wait uh i'm just a little bit + + + align:start position:0% +yeah wait uh i'm just a little bit +confused so even when an image is like + + align:start position:0% +confused so even when an image is like + + + align:start position:0% +confused so even when an image is like +completely still like even if you're not + + align:start position:0% +completely still like even if you're not + + + align:start position:0% +completely still like even if you're not +detecting motion those neurons are still + + align:start position:0% +detecting motion those neurons are still + + + align:start position:0% +detecting motion those neurons are still +firing + + align:start position:0% +firing + + + align:start position:0% +firing +ah + + align:start position:0% +ah + + + align:start position:0% +ah +um that's a good question but but most + + align:start position:0% +um that's a good question but but most + + + align:start position:0% +um that's a good question but but most +likely it's the simple cases + + align:start position:0% +likely it's the simple cases + + + align:start position:0% +likely it's the simple cases +if this may have not worked beautifully + + align:start position:0% +if this may have not worked beautifully + + + align:start position:0% +if this may have not worked beautifully +in part because i screwed it up and + + align:start position:0% +in part because i screwed it up and + + + align:start position:0% +in part because i screwed it up and +didn't notice when it stopped + + align:start position:0% +didn't notice when it stopped + + + align:start position:0% +didn't notice when it stopped +but if it works well you should get a + + align:start position:0% +but if it works well you should get a + + + align:start position:0% +but if it works well you should get a +pretty powerful sense that after you see + + align:start position:0% +pretty powerful sense that after you see + + + align:start position:0% +pretty powerful sense that after you see +it expanding then when it's still it + + align:start position:0% +it expanding then when it's still it + + + align:start position:0% +it expanding then when it's still it +should seem to be contracting + + align:start position:0% +should seem to be contracting + + + align:start position:0% +should seem to be contracting +so when that happens + + align:start position:0% +so when that happens + + + align:start position:0% +so when that happens +the reading assigned for today tomorrow + + align:start position:0% +the reading assigned for today tomorrow + + + align:start position:0% +the reading assigned for today tomorrow +tomorrow night tells you what happens in + + align:start position:0% +tomorrow night tells you what happens in + + + align:start position:0% +tomorrow night tells you what happens in +your brain during that time when you are + + align:start position:0% +your brain during that time when you are + + + align:start position:0% +your brain during that time when you are +looking at stationary stimuli but + + align:start position:0% +looking at stationary stimuli but + + + align:start position:0% +looking at stationary stimuli but +experiencing motion + + align:start position:0% +experiencing motion + + + align:start position:0% +experiencing motion +so there's no motion in the stimulus but + + align:start position:0% +so there's no motion in the stimulus but + + + align:start position:0% +so there's no motion in the stimulus but +there's motion in your percept + + align:start position:0% +there's motion in your percept + + + align:start position:0% +there's motion in your percept +okay so that's the question + + align:start position:0% +okay so that's the question + + + align:start position:0% +okay so that's the question +right so read the paper and find out + + align:start position:0% +right so read the paper and find out + + + align:start position:0% +right so read the paper and find out +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +all right + + align:start position:0% + + + + align:start position:0% + +all right so all of that + + align:start position:0% +all right so all of that + + + align:start position:0% +all right so all of that +tells us just that there are neurons + + align:start position:0% +tells us just that there are neurons + + + align:start position:0% +tells us just that there are neurons +some place in your brain that are + + align:start position:0% +some place in your brain that are + + + align:start position:0% +some place in your brain that are +sensitive to the direction of motion + + align:start position:0% +sensitive to the direction of motion + + + align:start position:0% +sensitive to the direction of motion +it doesn't tell us that they're in mt in + + align:start position:0% +it doesn't tell us that they're in mt in + + + align:start position:0% +it doesn't tell us that they're in mt in +particular + + align:start position:0% +particular + + + align:start position:0% +particular +but the assigned reading will talk about + + align:start position:0% +but the assigned reading will talk about + + + align:start position:0% +but the assigned reading will talk about +that + + align:start position:0% +that + + + align:start position:0% +that +okay + + align:start position:0% +okay + + + align:start position:0% +okay +right a further bit of evidence + + align:start position:0% +right a further bit of evidence + + + align:start position:0% +right a further bit of evidence +is remember i said how in monkeys next + + align:start position:0% +is remember i said how in monkeys next + + + align:start position:0% +is remember i said how in monkeys next +door bits in mt have have have similar + + align:start position:0% +door bits in mt have have have similar + + + align:start position:0% +door bits in mt have have have similar +direction selectivity + + align:start position:0% +direction selectivity + + + align:start position:0% +direction selectivity +that means you can also inject an + + align:start position:0% +that means you can also inject an + + + align:start position:0% +that means you can also inject an +electrical signal in a little patch of + + align:start position:0% +electrical signal in a little patch of + + + align:start position:0% +electrical signal in a little patch of +mt + + align:start position:0% +mt + + + align:start position:0% +mt +and give the monkey a net percept of a + + align:start position:0% +and give the monkey a net percept of a + + + align:start position:0% +and give the monkey a net percept of a +direction of motion + + align:start position:0% +direction of motion + + + align:start position:0% +direction of motion +okay + + align:start position:0% +okay + + + align:start position:0% +okay +if all the neurons were scrambled around + + align:start position:0% +if all the neurons were scrambled around + + + align:start position:0% +if all the neurons were scrambled around +spatially so that there was no + + align:start position:0% +spatially so that there was no + + + align:start position:0% +spatially so that there was no +clustering of neurons sensitive to say + + align:start position:0% +clustering of neurons sensitive to say + + + align:start position:0% +clustering of neurons sensitive to say +this direction of motion then + + align:start position:0% +this direction of motion then + + + align:start position:0% +this direction of motion then +stimulation wouldn't do anything + + align:start position:0% +stimulation wouldn't do anything + + + align:start position:0% +stimulation wouldn't do anything +but if you train a monkey to tell you + + align:start position:0% +but if you train a monkey to tell you + + + align:start position:0% +but if you train a monkey to tell you +what direction of motion he's seeing and + + align:start position:0% +what direction of motion he's seeing and + + + align:start position:0% +what direction of motion he's seeing and +you show them just random dots that + + align:start position:0% +you show them just random dots that + + + align:start position:0% +you show them just random dots that +aren't moving in any direction and you + + align:start position:0% +aren't moving in any direction and you + + + align:start position:0% +aren't moving in any direction and you +stimulate one little patch + + align:start position:0% +stimulate one little patch + + + align:start position:0% +stimulate one little patch +it'll tell you the direction of motion + + align:start position:0% +it'll tell you the direction of motion + + + align:start position:0% +it'll tell you the direction of motion +of the neurons in that little patch + + align:start position:0% +of the neurons in that little patch + + + align:start position:0% +of the neurons in that little patch +and that is much more powerful evidence + + align:start position:0% +and that is much more powerful evidence + + + align:start position:0% +and that is much more powerful evidence +that that region + + align:start position:0% +that that region + + + align:start position:0% +that that region +is not only responsive to motion but + + align:start position:0% +is not only responsive to motion but + + + align:start position:0% +is not only responsive to motion but +causally involved in your perception of + + align:start position:0% +causally involved in your perception of + + + align:start position:0% +causally involved in your perception of +motion + + align:start position:0% +motion + + + align:start position:0% +motion +okay i'm a little obsessed with this + + align:start position:0% +okay i'm a little obsessed with this + + + align:start position:0% +okay i'm a little obsessed with this +distinction between + + align:start position:0% +distinction between + + + align:start position:0% +distinction between +you know recording responses and + + align:start position:0% +you know recording responses and + + + align:start position:0% +you know recording responses and +establishing causality so we'll go over + + align:start position:0% +establishing causality so we'll go over + + + align:start position:0% +establishing causality so we'll go over +this in more detail later but i want you + + align:start position:0% +this in more detail later but i want you + + + align:start position:0% +this in more detail later but i want you +to start getting used to that idea + + align:start position:0% +to start getting used to that idea + + + align:start position:0% +to start getting used to that idea +another way to test the causal role of + + align:start position:0% +another way to test the causal role of + + + align:start position:0% +another way to test the causal role of +area mt + + align:start position:0% +area mt + + + align:start position:0% +area mt +in + + align:start position:0% +in + + + align:start position:0% +in +motion is + + align:start position:0% +motion is + + + align:start position:0% +motion is +with patients with brain damage and area + + align:start position:0% +with patients with brain damage and area + + + align:start position:0% +with patients with brain damage and area +mt + + align:start position:0% +mt + + + align:start position:0% +mt +so there's one famous patient who had + + align:start position:0% +so there's one famous patient who had + + + align:start position:0% +so there's one famous patient who had +brain damage right there + + align:start position:0% +brain damage right there + + + align:start position:0% +brain damage right there +which is right where mt usually is + + align:start position:0% +which is right where mt usually is + + + align:start position:0% +which is right where mt usually is +and she could not see motion and she + + align:start position:0% +and she could not see motion and she + + + align:start position:0% +and she could not see motion and she +reports all kinds of things like + + align:start position:0% +reports all kinds of things like + + + align:start position:0% +reports all kinds of things like +difficulty crossing the street + + align:start position:0% +difficulty crossing the street + + + align:start position:0% +difficulty crossing the street +difficulty catching balls + + align:start position:0% +difficulty catching balls + + + align:start position:0% +difficulty catching balls +difficulty pouring water into a cup + + align:start position:0% +difficulty pouring water into a cup + + + align:start position:0% +difficulty pouring water into a cup +okay just as you guys saw earlier that's + + align:start position:0% +okay just as you guys saw earlier that's + + + align:start position:0% +okay just as you guys saw earlier that's +called akinatopsia + + align:start position:0% +called akinatopsia + + + align:start position:0% +called akinatopsia +right can it like kinetics motion a not + + align:start position:0% +right can it like kinetics motion a not + + + align:start position:0% +right can it like kinetics motion a not +motion right opsia eyes + + align:start position:0% +motion right opsia eyes + + + align:start position:0% +motion right opsia eyes +okay + + align:start position:0% +okay + + + align:start position:0% +okay +um + + align:start position:0% +um + + + align:start position:0% +um +all right so i started with these + + align:start position:0% +all right so i started with these + + + align:start position:0% +all right so i started with these +criteria for what makes something a + + align:start position:0% +criteria for what makes something a + + + align:start position:0% +criteria for what makes something a +visual a + + align:start position:0% +visual a + + + align:start position:0% +visual a +distinct area and one piece of evidence + + align:start position:0% +distinct area and one piece of evidence + + + align:start position:0% +distinct area and one piece of evidence +is function and i just gave you a whole + + align:start position:0% +is function and i just gave you a whole + + + align:start position:0% +is function and i just gave you a whole +bunch of different kinds of evidence for + + align:start position:0% +bunch of different kinds of evidence for + + + align:start position:0% +bunch of different kinds of evidence for +distinct function and visual area mt + + align:start position:0% +distinct function and visual area mt + + + align:start position:0% +distinct function and visual area mt +that it's specifically involved in + + align:start position:0% +that it's specifically involved in + + + align:start position:0% +that it's specifically involved in +motion + + align:start position:0% +motion + + + align:start position:0% +motion +processing + + align:start position:0% +processing + + + align:start position:0% +processing +and the two other criteria which are + + align:start position:0% +and the two other criteria which are + + + align:start position:0% +and the two other criteria which are +getting short shrift but i'll just toss + + align:start position:0% +getting short shrift but i'll just toss + + + align:start position:0% +getting short shrift but i'll just toss +them off and we'll return to them + + align:start position:0% +them off and we'll return to them + + + align:start position:0% +them off and we'll return to them +one is the distinct connectivity of that + + align:start position:0% +one is the distinct connectivity of that + + + align:start position:0% +one is the distinct connectivity of that +region + + align:start position:0% +region + + + align:start position:0% +region +okay so you may have seen this horrific + + align:start position:0% +okay so you may have seen this horrific + + + align:start position:0% +okay so you may have seen this horrific +wiring diagram of visual cortex in + + align:start position:0% +wiring diagram of visual cortex in + + + align:start position:0% +wiring diagram of visual cortex in +monkeys i think it comes up in like half + + align:start position:0% +monkeys i think it comes up in like half + + + align:start position:0% +monkeys i think it comes up in like half +the talks and classes in in my field + + align:start position:0% +the talks and classes in in my field + + + align:start position:0% +the talks and classes in in my field +this is the one down here and so there's + + align:start position:0% +this is the one down here and so there's + + + align:start position:0% +this is the one down here and so there's +lots and lots of different visual areas + + align:start position:0% +lots and lots of different visual areas + + + align:start position:0% +lots and lots of different visual areas +and there's a whole fancy wiring diagram + + align:start position:0% +and there's a whole fancy wiring diagram + + + align:start position:0% +and there's a whole fancy wiring diagram +and smack in the middle of this diagram + + align:start position:0% +and smack in the middle of this diagram + + + align:start position:0% +and smack in the middle of this diagram +that's visual area mt and if you blow + + align:start position:0% +that's visual area mt and if you blow + + + align:start position:0% +that's visual area mt and if you blow +this up and stare at it you'll see that + + align:start position:0% +this up and stare at it you'll see that + + + align:start position:0% +this up and stare at it you'll see that +mt has a particular set of connections + + align:start position:0% +mt has a particular set of connections + + + align:start position:0% +mt has a particular set of connections +to other visual regions and cortex and + + align:start position:0% +to other visual regions and cortex and + + + align:start position:0% +to other visual regions and cortex and +its particular set of connections are + + align:start position:0% +its particular set of connections are + + + align:start position:0% +its particular set of connections are +different from the connections of any of + + align:start position:0% +different from the connections of any of + + + align:start position:0% +different from the connections of any of +those other regions it's part of its + + align:start position:0% +those other regions it's part of its + + + align:start position:0% +those other regions it's part of its +connectivity fingerprint or signature + + align:start position:0% +connectivity fingerprint or signature + + + align:start position:0% +connectivity fingerprint or signature +and that's another piece of evidence + + align:start position:0% +and that's another piece of evidence + + + align:start position:0% +and that's another piece of evidence +that it's a thing + + align:start position:0% +that it's a thing + + + align:start position:0% +that it's a thing +okay it's not just another like + + align:start position:0% +okay it's not just another like + + + align:start position:0% +okay it's not just another like +amorphous bit of cortex it's a + + align:start position:0% +amorphous bit of cortex it's a + + + align:start position:0% +amorphous bit of cortex it's a +particular thing in the brain + + align:start position:0% + + + + align:start position:0% + +and finally you might wonder is that bit + + align:start position:0% +and finally you might wonder is that bit + + + align:start position:0% +and finally you might wonder is that bit +of cortex physically different are the + + align:start position:0% +of cortex physically different are the + + + align:start position:0% +of cortex physically different are the +cells in there different are the layers + + align:start position:0% +cells in there different are the layers + + + align:start position:0% +cells in there different are the layers +of cortex different + + align:start position:0% +of cortex different + + + align:start position:0% +of cortex different +um in any way + + align:start position:0% +um in any way + + + align:start position:0% +um in any way +and from + + align:start position:0% +and from + + + align:start position:0% +and from +and you may remember from probably 900 + + align:start position:0% +and you may remember from probably 900 + + + align:start position:0% +and you may remember from probably 900 +about brodman areas like this dude + + align:start position:0% +about brodman areas like this dude + + + align:start position:0% +about brodman areas like this dude +corbinian brodeman + + align:start position:0% +corbinian brodeman + + + align:start position:0% +corbinian brodeman +sliced up lots of dead brains looked at + + align:start position:0% +sliced up lots of dead brains looked at + + + align:start position:0% +sliced up lots of dead brains looked at +them under a microscope and argued that + + align:start position:0% +them under a microscope and argued that + + + align:start position:0% +them under a microscope and argued that +were there were 52 different parts just + + align:start position:0% +were there were 52 different parts just + + + align:start position:0% +were there were 52 different parts just +from what it looked like if you slice + + align:start position:0% +from what it looked like if you slice + + + align:start position:0% +from what it looked like if you slice +them up under a microscope okay so we + + align:start position:0% +them up under a microscope okay so we + + + align:start position:0% +them up under a microscope okay so we +called those brodman areas and area 17 + + align:start position:0% +called those brodman areas and area 17 + + + align:start position:0% +called those brodman areas and area 17 +this primary visual cortex comes from + + align:start position:0% +this primary visual cortex comes from + + + align:start position:0% +this primary visual cortex comes from +brodman's terminology + + align:start position:0% +brodman's terminology + + + align:start position:0% +brodman's terminology +um + + align:start position:0% +um + + + align:start position:0% +um +and so he argued that there he thought + + align:start position:0% +and so he argued that there he thought + + + align:start position:0% +and so he argued that there he thought +these were distinct organs in the brain + + align:start position:0% +these were distinct organs in the brain + + + align:start position:0% +these were distinct organs in the brain +and he even inferred the specific + + align:start position:0% +and he even inferred the specific + + + align:start position:0% +and he even inferred the specific +histological differentiation of the + + align:start position:0% +histological differentiation of the + + + align:start position:0% +histological differentiation of the +cortical areas proves irrefutably their + + align:start position:0% +cortical areas proves irrefutably their + + + align:start position:0% +cortical areas proves irrefutably their +specific functional differentiation well + + align:start position:0% +specific functional differentiation well + + + align:start position:0% +specific functional differentiation well +it doesn't but never mind kind of + + align:start position:0% +it doesn't but never mind kind of + + + align:start position:0% +it doesn't but never mind kind of +sounded good + + align:start position:0% +sounded good + + + align:start position:0% +sounded good +anyway that was his idea + + align:start position:0% +anyway that was his idea + + + align:start position:0% +anyway that was his idea +and these kinds of distinct + + align:start position:0% +and these kinds of distinct + + + align:start position:0% +and these kinds of distinct +kind of cellular physical anatomical + + align:start position:0% +kind of cellular physical anatomical + + + align:start position:0% +kind of cellular physical anatomical +differences are very salient for primary + + align:start position:0% +differences are very salient for primary + + + align:start position:0% +differences are very salient for primary +cortical areas + + align:start position:0% +cortical areas + + + align:start position:0% +cortical areas +for vision and audition and touch + + align:start position:0% +for vision and audition and touch + + + align:start position:0% +for vision and audition and touch +and motor cortex but they're much + + align:start position:0% +and motor cortex but they're much + + + align:start position:0% +and motor cortex but they're much +muckier for lots of other areas + + align:start position:0% +muckier for lots of other areas + + + align:start position:0% +muckier for lots of other areas +one important exception which is why we + + align:start position:0% +one important exception which is why we + + + align:start position:0% +one important exception which is why we +chose this is area mt + + align:start position:0% +chose this is area mt + + + align:start position:0% +chose this is area mt +and so i'll end in one minute but just + + align:start position:0% +and so i'll end in one minute but just + + + align:start position:0% +and so i'll end in one minute but just +to tell you where this is going this is + + align:start position:0% +to tell you where this is going this is + + + align:start position:0% +to tell you where this is going this is +a flattened piece of monkey cortex + + align:start position:0% +a flattened piece of monkey cortex + + + align:start position:0% +a flattened piece of monkey cortex +rolled out like with a baking roller no + + align:start position:0% +rolled out like with a baking roller no + + + align:start position:0% +rolled out like with a baking roller no +i don't know some something like that so + + align:start position:0% +i don't know some something like that so + + + align:start position:0% +i don't know some something like that so +here's monkey cortex and there's v1 and + + align:start position:0% +here's monkey cortex and there's v1 and + + + align:start position:0% +here's monkey cortex and there's v1 and +v2 and it's a big mess but that big dark + + align:start position:0% +v2 and it's a big mess but that big dark + + + align:start position:0% +v2 and it's a big mess but that big dark +blob this bit of cortex is stained with + + align:start position:0% +blob this bit of cortex is stained with + + + align:start position:0% +blob this bit of cortex is stained with +something called cytochrome oxidase + + align:start position:0% +something called cytochrome oxidase + + + align:start position:0% +something called cytochrome oxidase +and that indicates metabolic activity + + align:start position:0% +and that indicates metabolic activity + + + align:start position:0% +and that indicates metabolic activity +mt neurons are very highly metabolically + + align:start position:0% +mt neurons are very highly metabolically + + + align:start position:0% +mt neurons are very highly metabolically +active and so here's a map + + align:start position:0% +active and so here's a map + + + align:start position:0% +active and so here's a map +of visual cortex and that exactly is + + align:start position:0% +of visual cortex and that exactly is + + + align:start position:0% +of visual cortex and that exactly is +area mt + + align:start position:0% +area mt + + + align:start position:0% +area mt +so area mt actually is + + align:start position:0% +so area mt actually is + + + align:start position:0% +so area mt actually is +histologically or + + align:start position:0% +histologically or + + + align:start position:0% +histologically or +psychoarchitectonically + + align:start position:0% +psychoarchitectonically + + + align:start position:0% +psychoarchitectonically +different from its neighbors + + align:start position:0% +different from its neighbors + + + align:start position:0% +different from its neighbors +and hence fits all of the criteria for a + + align:start position:0% +and hence fits all of the criteria for a + + + align:start position:0% +and hence fits all of the criteria for a +cortical area + + align:start position:0% +cortical area + + + align:start position:0% +cortical area +okay i went one minute over i realize i + + align:start position:0% +okay i went one minute over i realize i + + + align:start position:0% +okay i went one minute over i realize i +threw out a lot of terminology i don't + + align:start position:0% +threw out a lot of terminology i don't + + + align:start position:0% +threw out a lot of terminology i don't +want you to memorize too much so i made + + align:start position:0% +want you to memorize too much so i made + + + align:start position:0% +want you to memorize too much so i made +a list of the kinds of things that you + + align:start position:0% +a list of the kinds of things that you + + + align:start position:0% +a list of the kinds of things that you +should understand from this lecture the + + align:start position:0% +should understand from this lecture the + + + align:start position:0% +should understand from this lecture the +things that i think are important + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/bbh5AQTX8r4.txt b/bbh5AQTX8r4.txt new file mode 100644 index 0000000000000000000000000000000000000000..1a78074bf646cd48a5a797a01cea4db109981978 --- /dev/null +++ b/bbh5AQTX8r4.txt @@ -0,0 +1,10187 @@ +align:start position:0% + +the following content is provided by MIT + + align:start position:0% +the following content is provided by MIT + + + align:start position:0% +the following content is provided by MIT +opencourseware under a Creative Commons + + align:start position:0% +opencourseware under a Creative Commons + + + align:start position:0% +opencourseware under a Creative Commons +license additional information about our + + align:start position:0% +license additional information about our + + + align:start position:0% +license additional information about our +license and MIT open courseware in + + align:start position:0% +license and MIT open courseware in + + + align:start position:0% +license and MIT open courseware in +general is available at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +good morning class nice to see you again + + align:start position:0% +good morning class nice to see you again + + + align:start position:0% +good morning class nice to see you again +hope you had a a great weekend + + align:start position:0% +hope you had a a great weekend + + + align:start position:0% +hope you had a a great weekend +if you didn't it wasn't because of the + + align:start position:0% +if you didn't it wasn't because of the + + + align:start position:0% +if you didn't it wasn't because of the +weather + + align:start position:0% +weather + + + align:start position:0% +weather +so here I am once again a member of the + + align:start position:0% +so here I am once again a member of the + + + align:start position:0% +so here I am once again a member of the +walking wounded and we're talking about + + align:start position:0% +walking wounded and we're talking about + + + align:start position:0% +walking wounded and we're talking about +carbohydrates today as you may recall at + + align:start position:0% +carbohydrates today as you may recall at + + + align:start position:0% +carbohydrates today as you may recall at +least we were at the end of our + + align:start position:0% +least we were at the end of our + + + align:start position:0% +least we were at the end of our +discussion last time + + align:start position:0% +discussion last time + + + align:start position:0% +discussion last time +and we made the point that uh + + align:start position:0% +and we made the point that uh + + + align:start position:0% +and we made the point that uh +these multiple hydroxyl groups on the + + align:start position:0% +these multiple hydroxyl groups on the + + + align:start position:0% +these multiple hydroxyl groups on the +carbohydrates on the one hand determine + + align:start position:0% +carbohydrates on the one hand determine + + + align:start position:0% +carbohydrates on the one hand determine +the identity of a various kinds of uh + + align:start position:0% +the identity of a various kinds of uh + + + align:start position:0% +the identity of a various kinds of uh +sugars just the orientation the + + align:start position:0% +sugars just the orientation the + + + align:start position:0% +sugars just the orientation the +three-dimensional orientation of them + + align:start position:0% +three-dimensional orientation of them + + + align:start position:0% +three-dimensional orientation of them +uh for one thing and uh for another that + + align:start position:0% +uh for one thing and uh for another that + + + align:start position:0% +uh for one thing and uh for another that +these multiple hydroxyl groups + + align:start position:0% +these multiple hydroxyl groups + + + align:start position:0% +these multiple hydroxyl groups +represented the opportunity for forming + + align:start position:0% +represented the opportunity for forming + + + align:start position:0% +represented the opportunity for forming +covalent bonds with other + + align:start position:0% +covalent bonds with other + + + align:start position:0% +covalent bonds with other +monosaccharides as is indicated here in + + align:start position:0% +monosaccharides as is indicated here in + + + align:start position:0% +monosaccharides as is indicated here in +these disaccharides or covalent bonds + + align:start position:0% +these disaccharides or covalent bonds + + + align:start position:0% +these disaccharides or covalent bonds +end to end to create large molecules + + align:start position:0% +end to end to create large molecules + + + align:start position:0% +end to end to create large molecules +which will increasingly be the theme of + + align:start position:0% +which will increasingly be the theme of + + + align:start position:0% +which will increasingly be the theme of +our discussion today + + align:start position:0% +our discussion today + + + align:start position:0% +our discussion today +I.E when I talk about large molecules we + + align:start position:0% +I.E when I talk about large molecules we + + + align:start position:0% +I.E when I talk about large molecules we +just use the phrase generically of + + align:start position:0% +just use the phrase generically of + + + align:start position:0% +just use the phrase generically of +macromolecules + + align:start position:0% +macromolecules + + + align:start position:0% +macromolecules +since in principle uh these end-to-end + + align:start position:0% +since in principle uh these end-to-end + + + align:start position:0% +since in principle uh these end-to-end +joinings of molecules which involve the + + align:start position:0% +joinings of molecules which involve the + + + align:start position:0% +joinings of molecules which involve the +dehydration and the formation of these + + align:start position:0% +dehydration and the formation of these + + + align:start position:0% +dehydration and the formation of these +covalent bonds like right here can + + align:start position:0% +covalent bonds like right here can + + + align:start position:0% +covalent bonds like right here can +create molecules that are hundreds + + align:start position:0% +create molecules that are hundreds + + + align:start position:0% +create molecules that are hundreds +indeed even thousands of subunits long + + align:start position:0% +indeed even thousands of subunits long + + + align:start position:0% +indeed even thousands of subunits long +so here if we're talking about a polymer + + align:start position:0% +so here if we're talking about a polymer + + + align:start position:0% +so here if we're talking about a polymer +we refer to each one of these uh + + align:start position:0% +we refer to each one of these uh + + + align:start position:0% +we refer to each one of these uh +subunits of the polymer as being a + + align:start position:0% +subunits of the polymer as being a + + + align:start position:0% +subunits of the polymer as being a +monomer and the aggregate as a whole as + + align:start position:0% +monomer and the aggregate as a whole as + + + align:start position:0% +monomer and the aggregate as a whole as +being a polymer + + align:start position:0% +being a polymer + + + align:start position:0% +being a polymer +here we uh uh we touched upon the fact + + align:start position:0% +here we uh uh we touched upon the fact + + + align:start position:0% +here we uh uh we touched upon the fact +toward the end of last lecture in fact + + align:start position:0% +toward the end of last lecture in fact + + + align:start position:0% +toward the end of last lecture in fact +at the very end + + align:start position:0% +at the very end + + + align:start position:0% +at the very end +that um one can array one can cross-link + + align:start position:0% +that um one can array one can cross-link + + + align:start position:0% +that um one can array one can cross-link +these long linear chains of + + align:start position:0% +these long linear chains of + + + align:start position:0% +these long linear chains of +carbohydrates and here we see the fact + + align:start position:0% +carbohydrates and here we see the fact + + + align:start position:0% +carbohydrates and here we see the fact +that glycogen which is a form + + align:start position:0% +that glycogen which is a form + + + align:start position:0% +that glycogen which is a form +of glucose that is stored in our liver + + align:start position:0% +of glucose that is stored in our liver + + + align:start position:0% +of glucose that is stored in our liver +largely into a small extent in the + + align:start position:0% +largely into a small extent in the + + + align:start position:0% +largely into a small extent in the +muscles actually is is um + + align:start position:0% +muscles actually is is um + + + align:start position:0% +muscles actually is is um +it's cross Branch so if one looks at a + + align:start position:0% +it's cross Branch so if one looks at a + + + align:start position:0% +it's cross Branch so if one looks at a +if one draws on a much smaller scale a + + align:start position:0% +if one draws on a much smaller scale a + + + align:start position:0% +if one draws on a much smaller scale a +glycogen molecule one might draw a + + align:start position:0% +glycogen molecule one might draw a + + + align:start position:0% +glycogen molecule one might draw a +picture that looks like this + + align:start position:0% +picture that looks like this + + + align:start position:0% +picture that looks like this +then it looks almost like a Christmas + + align:start position:0% +then it looks almost like a Christmas + + + align:start position:0% +then it looks almost like a Christmas +tree with multiple branches and the + + align:start position:0% +tree with multiple branches and the + + + align:start position:0% +tree with multiple branches and the +purpose of this is actually to sequester + + align:start position:0% +purpose of this is actually to sequester + + + align:start position:0% +purpose of this is actually to sequester +the glucose to store the glucose in a + + align:start position:0% +the glucose to store the glucose in a + + + align:start position:0% +the glucose to store the glucose in a +metabolically inactive form until the + + align:start position:0% +metabolically inactive form until the + + + align:start position:0% +metabolically inactive form until the +time comes that the organism needs once + + align:start position:0% +time comes that the organism needs once + + + align:start position:0% +time comes that the organism needs once +again the energy that is stored in the + + align:start position:0% +again the energy that is stored in the + + + align:start position:0% +again the energy that is stored in the +glucose upon which occasion these bonds + + align:start position:0% +glucose upon which occasion these bonds + + + align:start position:0% +glucose upon which occasion these bonds +are rapidly broken down and the glucose + + align:start position:0% +are rapidly broken down and the glucose + + + align:start position:0% +are rapidly broken down and the glucose +is mobilized and put into the + + align:start position:0% +is mobilized and put into the + + + align:start position:0% +is mobilized and put into the +circulation for eventual disposition and + + align:start position:0% +circulation for eventual disposition and + + + align:start position:0% +circulation for eventual disposition and +use in certain specific tissues + + align:start position:0% +use in certain specific tissues + + + align:start position:0% +use in certain specific tissues +while it's encumbered in these high + + align:start position:0% +while it's encumbered in these high + + + align:start position:0% +while it's encumbered in these high +molecular weight polymers the glucose is + + align:start position:0% +molecular weight polymers the glucose is + + + align:start position:0% +molecular weight polymers the glucose is +essentially metabolically inactive the + + align:start position:0% +essentially metabolically inactive the + + + align:start position:0% +essentially metabolically inactive the +body doesn't realize it's there + + align:start position:0% +body doesn't realize it's there + + + align:start position:0% +body doesn't realize it's there +and we can as a consequence store large + + align:start position:0% +and we can as a consequence store large + + + align:start position:0% +and we can as a consequence store large +amounts of energy in these glycogen + + align:start position:0% +amounts of energy in these glycogen + + + align:start position:0% +amounts of energy in these glycogen +molecules and it can be stored there + + align:start position:0% +molecules and it can be stored there + + + align:start position:0% +molecules and it can be stored there +indefinitely + + align:start position:0% +indefinitely + + + align:start position:0% +indefinitely +now the fact is that uh this this idea + + align:start position:0% +now the fact is that uh this this idea + + + align:start position:0% +now the fact is that uh this this idea +of end-to-end polymerization that I just + + align:start position:0% +of end-to-end polymerization that I just + + + align:start position:0% +of end-to-end polymerization that I just +mentioned can be extended to other + + align:start position:0% +mentioned can be extended to other + + + align:start position:0% +mentioned can be extended to other +macromolecules which also become linked + + align:start position:0% +macromolecules which also become linked + + + align:start position:0% +macromolecules which also become linked +end to end in specific kinds of polymers + + align:start position:0% +end to end in specific kinds of polymers + + + align:start position:0% +end to end in specific kinds of polymers +and here we are moving now into the into + + align:start position:0% +and here we are moving now into the into + + + align:start position:0% +and here we are moving now into the into +the notion of talking about amino acids + + align:start position:0% +the notion of talking about amino acids + + + align:start position:0% +the notion of talking about amino acids +and we're talking about proteins if we + + align:start position:0% +and we're talking about proteins if we + + + align:start position:0% +and we're talking about proteins if we +look at an amino acid what we see is it + + align:start position:0% +look at an amino acid what we see is it + + + align:start position:0% +look at an amino acid what we see is it +has an important + + align:start position:0% +has an important + + + align:start position:0% +has an important +structure like this here's a central + + align:start position:0% +structure like this here's a central + + + align:start position:0% +structure like this here's a central +carbon and for in principle distinct + + align:start position:0% +carbon and for in principle distinct + + + align:start position:0% +carbon and for in principle distinct +side chains where R represents some side + + align:start position:0% +side chains where R represents some side + + + align:start position:0% +side chains where R represents some side +chain that can be any one of as we'll + + align:start position:0% +chain that can be any one of as we'll + + + align:start position:0% +chain that can be any one of as we'll +see shortly any one of 20 distinct + + align:start position:0% +see shortly any one of 20 distinct + + + align:start position:0% +see shortly any one of 20 distinct +identities + + align:start position:0% +identities + + + align:start position:0% +identities +but the old amino acids share in common + + align:start position:0% +but the old amino acids share in common + + + align:start position:0% +but the old amino acids share in common +the property that they have this overall + + align:start position:0% +the property that they have this overall + + + align:start position:0% +the property that they have this overall +structure and as you may recall from our + + align:start position:0% +structure and as you may recall from our + + + align:start position:0% +structure and as you may recall from our +discussion + + align:start position:0% +discussion + + + align:start position:0% +discussion +of discussions of last week at neutral + + align:start position:0% +of discussions of last week at neutral + + + align:start position:0% +of discussions of last week at neutral +pH it wouldn't a an amino acid of this + + align:start position:0% +pH it wouldn't a an amino acid of this + + + align:start position:0% +pH it wouldn't a an amino acid of this +sort whatever Aries wouldn't look like + + align:start position:0% +sort whatever Aries wouldn't look like + + + align:start position:0% +sort whatever Aries wouldn't look like +this at all + + align:start position:0% +this at all + + + align:start position:0% +this at all +because the amine group would attract an + + align:start position:0% +because the amine group would attract an + + + align:start position:0% +because the amine group would attract an +extra proton causing it to become + + align:start position:0% +extra proton causing it to become + + + align:start position:0% +extra proton causing it to become +positively charged and the carboxyl + + align:start position:0% +positively charged and the carboxyl + + + align:start position:0% +positively charged and the carboxyl +group would release a proton causing it + + align:start position:0% +group would release a proton causing it + + + align:start position:0% +group would release a proton causing it +to become negatively charged + + align:start position:0% +to become negatively charged + + + align:start position:0% +to become negatively charged +and as you might deduce from this at + + align:start position:0% +and as you might deduce from this at + + + align:start position:0% +and as you might deduce from this at +very low PH due to the greatly increased + + align:start position:0% +very low PH due to the greatly increased + + + align:start position:0% +very low PH due to the greatly increased +concentration of protons free protons in + + align:start position:0% +concentration of protons free protons in + + + align:start position:0% +concentration of protons free protons in +the solution the equilibrium will be + + align:start position:0% +the solution the equilibrium will be + + + align:start position:0% +the solution the equilibrium will be +would be driven more in favor of + + align:start position:0% +would be driven more in favor of + + + align:start position:0% +would be driven more in favor of +reattaching a proton to the carboxyl + + align:start position:0% +reattaching a proton to the carboxyl + + + align:start position:0% +reattaching a proton to the carboxyl +group just because there are so many of + + align:start position:0% +group just because there are so many of + + + align:start position:0% +group just because there are so many of +these protons around + + align:start position:0% +these protons around + + + align:start position:0% +these protons around +conversely at very high pH where the + + align:start position:0% +conversely at very high pH where the + + + align:start position:0% +conversely at very high pH where the +hydroxyl ions are in in the predominance + + align:start position:0% +hydroxyl ions are in in the predominance + + + align:start position:0% +hydroxyl ions are in in the predominance +they obviously tend to scavenge protons + + align:start position:0% +they obviously tend to scavenge protons + + + align:start position:0% +they obviously tend to scavenge protons +reducing the level of protons to very + + align:start position:0% +reducing the level of protons to very + + + align:start position:0% +reducing the level of protons to very +low level in in the water and under very + + align:start position:0% +low level in in the water and under very + + + align:start position:0% +low level in in the water and under very +high pH conditions this proton would be + + align:start position:0% +high pH conditions this proton would be + + + align:start position:0% +high pH conditions this proton would be +released and pulled away by the hydroxyl + + align:start position:0% +released and pulled away by the hydroxyl + + + align:start position:0% +released and pulled away by the hydroxyl +ions causing this amine group once again + + align:start position:0% +ions causing this amine group once again + + + align:start position:0% +ions causing this amine group once again +to return to its negative charge state + + align:start position:0% +to return to its negative charge state + + + align:start position:0% +to return to its negative charge state +now the fact of the matter is that uh + + align:start position:0% +now the fact of the matter is that uh + + + align:start position:0% +now the fact of the matter is that uh +these amino acids are + + align:start position:0% +these amino acids are + + + align:start position:0% +these amino acids are +exist in a very specific + + align:start position:0% +exist in a very specific + + + align:start position:0% +exist in a very specific +three-dimensional configuration and + + align:start position:0% +three-dimensional configuration and + + + align:start position:0% +three-dimensional configuration and +that's Illustrated much more nicely here + + align:start position:0% +that's Illustrated much more nicely here + + + align:start position:0% +that's Illustrated much more nicely here +than I could possibly draw on the board + + align:start position:0% +than I could possibly draw on the board + + + align:start position:0% +than I could possibly draw on the board +which in any case would be hopeless + + align:start position:0% +which in any case would be hopeless + + + align:start position:0% +which in any case would be hopeless +um which is that you can see in + + align:start position:0% +um which is that you can see in + + + align:start position:0% +um which is that you can see in +principle that once you have four + + align:start position:0% +principle that once you have four + + + align:start position:0% +principle that once you have four +distinct + + align:start position:0% +distinct + + + align:start position:0% +distinct +side groups coming off of a carbon that + + align:start position:0% +side groups coming off of a carbon that + + + align:start position:0% +side groups coming off of a carbon that +there is in principle two different ways + + align:start position:0% +there is in principle two different ways + + + align:start position:0% +there is in principle two different ways +to um to create them and this is + + align:start position:0% +to um to create them and this is + + + align:start position:0% +to um to create them and this is +sometimes called chirality chiral you + + align:start position:0% +sometimes called chirality chiral you + + + align:start position:0% +sometimes called chirality chiral you +see is the form right here the hands are + + align:start position:0% +see is the form right here the hands are + + + align:start position:0% +see is the form right here the hands are +chiral if I try as much as I will to + + align:start position:0% +chiral if I try as much as I will to + + + align:start position:0% +chiral if I try as much as I will to +superimpose one hand on top of another + + align:start position:0% +superimpose one hand on top of another + + + align:start position:0% +superimpose one hand on top of another +it doesn't work because there are mirror + + align:start position:0% +it doesn't work because there are mirror + + + align:start position:0% +it doesn't work because there are mirror +images of one another which are + + align:start position:0% +images of one another which are + + + align:start position:0% +images of one another which are +asymmetrical and as a consequence we see + + align:start position:0% +asymmetrical and as a consequence we see + + + align:start position:0% +asymmetrical and as a consequence we see +a similar kind of relationship occurring + + align:start position:0% +a similar kind of relationship occurring + + + align:start position:0% +a similar kind of relationship occurring +here + + align:start position:0% +here + + + align:start position:0% +here +um + + align:start position:0% +um + + + align:start position:0% +um +where we see that these two forms of + + align:start position:0% +where we see that these two forms of + + + align:start position:0% +where we see that these two forms of +amino acids could in principle exist and + + align:start position:0% +amino acids could in principle exist and + + + align:start position:0% +amino acids could in principle exist and +they're not interchangeable unless one + + align:start position:0% +they're not interchangeable unless one + + + align:start position:0% +they're not interchangeable unless one +breaks one of the bonds and reforms it + + align:start position:0% +breaks one of the bonds and reforms it + + + align:start position:0% +breaks one of the bonds and reforms it +these two forms are called the L and the + + align:start position:0% +these two forms are called the L and the + + + align:start position:0% +these two forms are called the L and the +D and it turns out that the L form is + + align:start position:0% +D and it turns out that the L form is + + + align:start position:0% +D and it turns out that the L form is +the one that's uh used by virtually all + + align:start position:0% +the one that's uh used by virtually all + + + align:start position:0% +the one that's uh used by virtually all +life forms on the planet I.E there was + + align:start position:0% +life forms on the planet I.E there was + + + align:start position:0% +life forms on the planet I.E there was +an arbitrary Choice made sometime about + + align:start position:0% +an arbitrary Choice made sometime about + + + align:start position:0% +an arbitrary Choice made sometime about +three billion years ago and more to use + + align:start position:0% +three billion years ago and more to use + + + align:start position:0% +three billion years ago and more to use +one of the two + + align:start position:0% +one of the two + + + align:start position:0% +one of the two +um three-dimensional configurations and + + align:start position:0% +um three-dimensional configurations and + + + align:start position:0% +um three-dimensional configurations and +not to use the other the other is found + + align:start position:0% +not to use the other the other is found + + + align:start position:0% +not to use the other the other is found +in certain rare exceptions but virtually + + align:start position:0% +in certain rare exceptions but virtually + + + align:start position:0% +in certain rare exceptions but virtually +I all life forms on this planet use the + + align:start position:0% +I all life forms on this planet use the + + + align:start position:0% +I all life forms on this planet use the +L form that said by the way this begins + + align:start position:0% +L form that said by the way this begins + + + align:start position:0% +L form that said by the way this begins +to indicate some of the arbitrary + + align:start position:0% +to indicate some of the arbitrary + + + align:start position:0% +to indicate some of the arbitrary +decisions that were made early during + + align:start position:0% +decisions that were made early during + + + align:start position:0% +decisions that were made early during +Evolution because we could imagine on + + align:start position:0% +Evolution because we could imagine on + + + align:start position:0% +Evolution because we could imagine on +another planet if life were to exist + + align:start position:0% +another planet if life were to exist + + + align:start position:0% +another planet if life were to exist +there and if it were to depend on amino + + align:start position:0% +there and if it were to depend on amino + + + align:start position:0% +there and if it were to depend on amino +acids that that evolutionary system + + align:start position:0% +acids that that evolutionary system + + + align:start position:0% +acids that that evolutionary system +might have chosen the D form so this is + + align:start position:0% +might have chosen the D form so this is + + + align:start position:0% +might have chosen the D form so this is +sort of a luck of the draw this is + + align:start position:0% +sort of a luck of the draw this is + + + align:start position:0% +sort of a luck of the draw this is +actually the way things evolved here + + align:start position:0% +actually the way things evolved here + + + align:start position:0% +actually the way things evolved here +and what we begin to see now is if we + + align:start position:0% +and what we begin to see now is if we + + + align:start position:0% +and what we begin to see now is if we +talk about proteins or uh if we want to + + align:start position:0% +talk about proteins or uh if we want to + + + align:start position:0% +talk about proteins or uh if we want to +be more specific and use the more + + align:start position:0% +be more specific and use the more + + + align:start position:0% +be more specific and use the more +biochemical term polypeptide + + align:start position:0% +biochemical term polypeptide + + + align:start position:0% +biochemical term polypeptide +we see once again we have an end-to-end + + align:start position:0% +we see once again we have an end-to-end + + + align:start position:0% +we see once again we have an end-to-end +joining system + + align:start position:0% +joining system + + + align:start position:0% +joining system +which is a bit different from that which + + align:start position:0% +which is a bit different from that which + + + align:start position:0% +which is a bit different from that which +the mono saccharides employee to create + + align:start position:0% +the mono saccharides employee to create + + + align:start position:0% +the mono saccharides employee to create +long chains of of glycogen or of starch + + align:start position:0% +long chains of of glycogen or of starch + + + align:start position:0% +long chains of of glycogen or of starch +because here we see once again a + + align:start position:0% +because here we see once again a + + + align:start position:0% +because here we see once again a +dehydration reaction + + align:start position:0% +dehydration reaction + + + align:start position:0% +dehydration reaction +where in a mean group and a carboxyl + + align:start position:0% +where in a mean group and a carboxyl + + + align:start position:0% +where in a mean group and a carboxyl +group are caused to uh shed the hydroxyl + + align:start position:0% +group are caused to uh shed the hydroxyl + + + align:start position:0% +group are caused to uh shed the hydroxyl +and the proton + + align:start position:0% +and the proton + + + align:start position:0% +and the proton +causing the formation of a peptide bond + + align:start position:0% +causing the formation of a peptide bond + + + align:start position:0% +causing the formation of a peptide bond +and here we see this important very + + align:start position:0% +and here we see this important very + + + align:start position:0% +and here we see this important very +important biochemical entity a peptide + + align:start position:0% +important biochemical entity a peptide + + + align:start position:0% +important biochemical entity a peptide +bond consisting here of this carbonyl + + align:start position:0% +bond consisting here of this carbonyl + + + align:start position:0% +bond consisting here of this carbonyl +and this nitrogen + + align:start position:0% +and this nitrogen + + + align:start position:0% +and this nitrogen +fused in this specific way + + align:start position:0% +fused in this specific way + + + align:start position:0% +fused in this specific way +and of course if you recognize this as + + align:start position:0% +and of course if you recognize this as + + + align:start position:0% +and of course if you recognize this as +being a peptide bond then you can + + align:start position:0% +being a peptide bond then you can + + + align:start position:0% +being a peptide bond then you can +understand why proteins are sometimes + + align:start position:0% +understand why proteins are sometimes + + + align:start position:0% +understand why proteins are sometimes +given the term polypeptide + + align:start position:0% +given the term polypeptide + + + align:start position:0% +given the term polypeptide +in some cases if one has very short + + align:start position:0% +in some cases if one has very short + + + align:start position:0% +in some cases if one has very short +stretches of amino acids linked end to + + align:start position:0% +stretches of amino acids linked end to + + + align:start position:0% +stretches of amino acids linked end to +end like this we talk about these being + + align:start position:0% +end like this we talk about these being + + + align:start position:0% +end like this we talk about these being +oligopeptides where oligo is the general + + align:start position:0% +oligopeptides where oligo is the general + + + align:start position:0% +oligopeptides where oligo is the general +term used in biology to refer to a small + + align:start position:0% +term used in biology to refer to a small + + + align:start position:0% +term used in biology to refer to a small +number of things rather than a large + + align:start position:0% +number of things rather than a large + + + align:start position:0% +number of things rather than a large +number of of things + + align:start position:0% +number of of things + + + align:start position:0% +number of of things +and once again we have here the + + align:start position:0% +and once again we have here the + + + align:start position:0% +and once again we have here the +possibility + + align:start position:0% +possibility + + + align:start position:0% +possibility +infinitely there are no constraints in + + align:start position:0% +infinitely there are no constraints in + + + align:start position:0% +infinitely there are no constraints in +principle on making this 500 a thousand + + align:start position:0% +principle on making this 500 a thousand + + + align:start position:0% +principle on making this 500 a thousand +even two thousand amino acids long + + align:start position:0% +even two thousand amino acids long + + + align:start position:0% +even two thousand amino acids long +where each of these once again is an + + align:start position:0% +where each of these once again is an + + + align:start position:0% +where each of these once again is an +amino acid and we're once again I'm + + align:start position:0% +amino acid and we're once again I'm + + + align:start position:0% +amino acid and we're once again I'm +being very Coy about the identities of + + align:start position:0% +being very Coy about the identities of + + + align:start position:0% +being very Coy about the identities of +R1 and R2 which as I will indicate very + + align:start position:0% +R1 and R2 which as I will indicate very + + + align:start position:0% +R1 and R2 which as I will indicate very +shortly can be one of 20 distinct + + align:start position:0% +shortly can be one of 20 distinct + + + align:start position:0% +shortly can be one of 20 distinct +alternatives here you see uh that we're + + align:start position:0% +alternatives here you see uh that we're + + + align:start position:0% +alternatives here you see uh that we're +continuing this process of peptide bond + + align:start position:0% +continuing this process of peptide bond + + + align:start position:0% +continuing this process of peptide bond +formation + + align:start position:0% +formation + + + align:start position:0% +formation +and most importantly here is the + + align:start position:0% +and most importantly here is the + + + align:start position:0% +and most importantly here is the +realization that there is a polarity of + + align:start position:0% +realization that there is a polarity of + + + align:start position:0% +realization that there is a polarity of +elongation here it doesn't move with + + align:start position:0% +elongation here it doesn't move with + + + align:start position:0% +elongation here it doesn't move with +equal probability left to right or right + + align:start position:0% +equal probability left to right or right + + + align:start position:0% +equal probability left to right or right +to left we start at the amino end here + + align:start position:0% +to left we start at the amino end here + + + align:start position:0% +to left we start at the amino end here +this is the amino end and this is the + + align:start position:0% +this is the amino end and this is the + + + align:start position:0% +this is the amino end and this is the +carboxyl end the amino end and the + + align:start position:0% +carboxyl end the amino end and the + + + align:start position:0% +carboxyl end the amino end and the +carboxyl end and invariably again + + align:start position:0% +carboxyl end and invariably again + + + align:start position:0% +carboxyl end and invariably again +because of the way life has evolved on + + align:start position:0% +because of the way life has evolved on + + + align:start position:0% +because of the way life has evolved on +this planet + + align:start position:0% +this planet + + + align:start position:0% +this planet +the new amino acid is added on the + + align:start position:0% +the new amino acid is added on the + + + align:start position:0% +the new amino acid is added on the +carboxyl end and so when one often talks + + align:start position:0% +carboxyl end and so when one often talks + + + align:start position:0% +carboxyl end and so when one often talks +about uh proteins one refers to their + + align:start position:0% +about uh proteins one refers to their + + + align:start position:0% +about uh proteins one refers to their +n-terminal + + align:start position:0% +n-terminal + + + align:start position:0% +n-terminal +and to their C terminal ends + + align:start position:0% +and to their C terminal ends + + + align:start position:0% +and to their C terminal ends +these referring obviously to the amino + + align:start position:0% +these referring obviously to the amino + + + align:start position:0% +these referring obviously to the amino +group at one end and the carboxyl in at + + align:start position:0% +group at one end and the carboxyl in at + + + align:start position:0% +group at one end and the carboxyl in at +the other end so the polarity is always + + align:start position:0% +the other end so the polarity is always + + + align:start position:0% +the other end so the polarity is always +a a directed synthesis adding it on the + + align:start position:0% +a a directed synthesis adding it on the + + + align:start position:0% +a a directed synthesis adding it on the +c-terminal end in other words to use a a + + align:start position:0% +c-terminal end in other words to use a a + + + align:start position:0% +c-terminal end in other words to use a a +shorthand notation we think about + + align:start position:0% +shorthand notation we think about + + + align:start position:0% +shorthand notation we think about +um proteins is going in this with this + + align:start position:0% +um proteins is going in this with this + + + align:start position:0% +um proteins is going in this with this +polarity and towards C things are + + align:start position:0% +polarity and towards C things are + + + align:start position:0% +polarity and towards C things are +growing at the c-terminal and + + align:start position:0% +growing at the c-terminal and + + + align:start position:0% +growing at the c-terminal and +progressively + + align:start position:0% +progressively + + + align:start position:0% +progressively +and each time + + align:start position:0% +and each time + + + align:start position:0% +and each time +one can imagine the addition of an amino + + align:start position:0% +one can imagine the addition of an amino + + + align:start position:0% +one can imagine the addition of an amino +acid on the end of it so again it can be + + align:start position:0% +acid on the end of it so again it can be + + + align:start position:0% +acid on the end of it so again it can be +extended in principle indefinitely + + align:start position:0% +extended in principle indefinitely + + + align:start position:0% +extended in principle indefinitely +keep in mind as well something that's + + align:start position:0% +keep in mind as well something that's + + + align:start position:0% +keep in mind as well something that's +implicit in everything I'm telling you + + align:start position:0% +implicit in everything I'm telling you + + + align:start position:0% +implicit in everything I'm telling you +but I won't always mention it explicitly + + align:start position:0% +but I won't always mention it explicitly + + + align:start position:0% +but I won't always mention it explicitly +and that is virtually every biochemical + + align:start position:0% +and that is virtually every biochemical + + + align:start position:0% +and that is virtually every biochemical +reaction is reversible + + align:start position:0% +reaction is reversible + + + align:start position:0% +reaction is reversible +and therefore if one is able to form a + + align:start position:0% +and therefore if one is able to form a + + + align:start position:0% +and therefore if one is able to form a +peptide bond + + align:start position:0% +peptide bond + + + align:start position:0% +peptide bond +one is able to break it down by + + align:start position:0% +one is able to break it down by + + + align:start position:0% +one is able to break it down by +biological means as well I.E by + + align:start position:0% +biological means as well I.E by + + + align:start position:0% +biological means as well I.E by +introducing a water molecule back in and + + align:start position:0% +introducing a water molecule back in and + + + align:start position:0% +introducing a water molecule back in and +thereby using the process of hydrolysis + + align:start position:0% +thereby using the process of hydrolysis + + + align:start position:0% +thereby using the process of hydrolysis +which is the breakdown of a bond through + + align:start position:0% +which is the breakdown of a bond through + + + align:start position:0% +which is the breakdown of a bond through +the introduction of a water molecule + + align:start position:0% +the introduction of a water molecule + + + align:start position:0% +the introduction of a water molecule +to destroy the previously created Bond + + align:start position:0% +to destroy the previously created Bond + + + align:start position:0% +to destroy the previously created Bond +to use an MIT phrase the reversibility + + align:start position:0% +to use an MIT phrase the reversibility + + + align:start position:0% +to use an MIT phrase the reversibility +is intuitively obvious because if you + + align:start position:0% +is intuitively obvious because if you + + + align:start position:0% +is intuitively obvious because if you +were able to make a + + align:start position:0% +were able to make a + + + align:start position:0% +were able to make a +well + + align:start position:0% +well + + + align:start position:0% +well +I don't know it's still used but it was + + align:start position:0% +I don't know it's still used but it was + + + align:start position:0% +I don't know it's still used but it was +used in the late Stone Age around here + + align:start position:0% +used in the late Stone Age around here + + + align:start position:0% +used in the late Stone Age around here +anyhow so + + align:start position:0% +anyhow so + + + align:start position:0% +anyhow so +any biochemical action must be + + align:start position:0% +any biochemical action must be + + + align:start position:0% +any biochemical action must be +reversible because if for example this + + align:start position:0% +reversible because if for example this + + + align:start position:0% +reversible because if for example this +polymerization were irreversible + + align:start position:0% +polymerization were irreversible + + + align:start position:0% +polymerization were irreversible +then all the protein that was ever + + align:start position:0% +then all the protein that was ever + + + align:start position:0% +then all the protein that was ever +synthesized on the surface of the planet + + align:start position:0% +synthesized on the surface of the planet + + + align:start position:0% +synthesized on the surface of the planet +over the last three and a half billion + + align:start position:0% +over the last three and a half billion + + + align:start position:0% +over the last three and a half billion +years would accumulate progressively and + + align:start position:0% +years would accumulate progressively and + + + align:start position:0% +years would accumulate progressively and +obviously that doesn't happen and + + align:start position:0% +obviously that doesn't happen and + + + align:start position:0% +obviously that doesn't happen and +therefore macromolecular synthesis do + + align:start position:0% +therefore macromolecular synthesis do + + + align:start position:0% +therefore macromolecular synthesis do +the excessive proceeds forward obviously + + align:start position:0% +the excessive proceeds forward obviously + + + align:start position:0% +the excessive proceeds forward obviously +must go in the other direction as well + + align:start position:0% +must go in the other direction as well + + + align:start position:0% +must go in the other direction as well +and the resulting concentration of a + + align:start position:0% +and the resulting concentration of a + + + align:start position:0% +and the resulting concentration of a +complete protein is known as its steady + + align:start position:0% +complete protein is known as its steady + + + align:start position:0% +complete protein is known as its steady +state so we might make a protein + + align:start position:0% +state so we might make a protein + + + align:start position:0% +state so we might make a protein +at at one rate and break it down at the + + align:start position:0% +at at one rate and break it down at the + + + align:start position:0% +at at one rate and break it down at the +same rate and it's steady state + + align:start position:0% +same rate and it's steady state + + + align:start position:0% +same rate and it's steady state +concentration represents the compromise + + align:start position:0% +concentration represents the compromise + + + align:start position:0% +concentration represents the compromise +between these two I.E the concentration + + align:start position:0% +between these two I.E the concentration + + + align:start position:0% +between these two I.E the concentration +of such a protein that we might observe + + align:start position:0% +of such a protein that we might observe + + + align:start position:0% +of such a protein that we might observe +at any one point in time + + align:start position:0% +at any one point in time + + + align:start position:0% +at any one point in time +indeed the term steady state could be + + align:start position:0% +indeed the term steady state could be + + + align:start position:0% +indeed the term steady state could be +expanded to you to any process in which + + align:start position:0% +expanded to you to any process in which + + + align:start position:0% +expanded to you to any process in which +there's a synthesis and there's a + + align:start position:0% +there's a synthesis and there's a + + + align:start position:0% +there's a synthesis and there's a +breakdown of something and the + + align:start position:0% +breakdown of something and the + + + align:start position:0% +breakdown of something and the +equilibrium concentration which results + + align:start position:0% +equilibrium concentration which results + + + align:start position:0% +equilibrium concentration which results +is once again called the steady state + + align:start position:0% +is once again called the steady state + + + align:start position:0% +is once again called the steady state +um of that molecule now let's get down + + align:start position:0% +um of that molecule now let's get down + + + align:start position:0% +um of that molecule now let's get down +to the nitty-gritty which is obviously + + align:start position:0% +to the nitty-gritty which is obviously + + + align:start position:0% +to the nitty-gritty which is obviously +something which we can't avoid for very + + align:start position:0% +something which we can't avoid for very + + + align:start position:0% +something which we can't avoid for very +long which is to say the R's I.E the + + align:start position:0% +long which is to say the R's I.E the + + + align:start position:0% +long which is to say the R's I.E the +side chains + + align:start position:0% +side chains + + + align:start position:0% +side chains +once again here we see an arbitrary + + align:start position:0% +once again here we see an arbitrary + + + align:start position:0% +once again here we see an arbitrary +artifact of very early evolution in the + + align:start position:0% +artifact of very early evolution in the + + + align:start position:0% +artifact of very early evolution in the +biosphere because there are in effect 20 + + align:start position:0% +biosphere because there are in effect 20 + + + align:start position:0% +biosphere because there are in effect 20 +different side chains creating set 20 + + align:start position:0% +different side chains creating set 20 + + + align:start position:0% +different side chains creating set 20 +distinct amino acids + + align:start position:0% +distinct amino acids + + + align:start position:0% +distinct amino acids +which are used in proteins by all + + align:start position:0% +which are used in proteins by all + + + align:start position:0% +which are used in proteins by all +organisms on this planet + + align:start position:0% +organisms on this planet + + + align:start position:0% +organisms on this planet +again there are rare exceptions certain + + align:start position:0% +again there are rare exceptions certain + + + align:start position:0% +again there are rare exceptions certain +uh fungi and certain bacteria are able + + align:start position:0% +uh fungi and certain bacteria are able + + + align:start position:0% +uh fungi and certain bacteria are able +to make unusual amino acids but these + + align:start position:0% +to make unusual amino acids but these + + + align:start position:0% +to make unusual amino acids but these +are the basic building blocks of + + align:start position:0% +are the basic building blocks of + + + align:start position:0% +are the basic building blocks of +virtually all life forms on the planet + + align:start position:0% +virtually all life forms on the planet + + + align:start position:0% +virtually all life forms on the planet +99.99 of all the protein that is created + + align:start position:0% +99.99 of all the protein that is created + + + align:start position:0% +99.99 of all the protein that is created +is is synthesized through the + + align:start position:0% +is is synthesized through the + + + align:start position:0% +is is synthesized through the +polymerization of these 20 amino acids + + align:start position:0% +polymerization of these 20 amino acids + + + align:start position:0% +polymerization of these 20 amino acids +um and by the way uh one of the amino + + align:start position:0% +um and by the way uh one of the amino + + + align:start position:0% +um and by the way uh one of the amino +acids glycine over here you see it right + + align:start position:0% +acids glycine over here you see it right + + + align:start position:0% +acids glycine over here you see it right +here violates this rule of chirality and + + align:start position:0% +here violates this rule of chirality and + + + align:start position:0% +here violates this rule of chirality and +and you will recall before I said that + + align:start position:0% +and you will recall before I said that + + + align:start position:0% +and you will recall before I said that +because there are four distinct amino + + align:start position:0% +because there are four distinct amino + + + align:start position:0% +because there are four distinct amino +acids um + + align:start position:0% +acids um + + + align:start position:0% +acids um +uh four distinct side chains around a + + align:start position:0% +uh four distinct side chains around a + + + align:start position:0% +uh four distinct side chains around a +central carbon sometimes called the + + align:start position:0% +central carbon sometimes called the + + + align:start position:0% +central carbon sometimes called the +alpha carbon you always have a + + align:start position:0% +alpha carbon you always have a + + + align:start position:0% +alpha carbon you always have a +handedness of amino acids but in the + + align:start position:0% +handedness of amino acids but in the + + + align:start position:0% +handedness of amino acids but in the +case this cannot this uh notion cannot + + align:start position:0% +case this cannot this uh notion cannot + + + align:start position:0% +case this cannot this uh notion cannot +be respected in the case of glycine seen + + align:start position:0% +be respected in the case of glycine seen + + + align:start position:0% +be respected in the case of glycine seen +up here + + align:start position:0% +up here + + + align:start position:0% +up here +simply because we don't have four + + align:start position:0% +simply because we don't have four + + + align:start position:0% +simply because we don't have four +distinct here's the central carbon where + + align:start position:0% +distinct here's the central carbon where + + + align:start position:0% +distinct here's the central carbon where +I'm pointing with the red and here these + + align:start position:0% +I'm pointing with the red and here these + + + align:start position:0% +I'm pointing with the red and here these +two hydrogens are equivalent to one + + align:start position:0% +two hydrogens are equivalent to one + + + align:start position:0% +two hydrogens are equivalent to one +another they're not four distinct chains + + align:start position:0% +another they're not four distinct chains + + + align:start position:0% +another they're not four distinct chains +there's only three distinct chains here + + align:start position:0% +there's only three distinct chains here + + + align:start position:0% +there's only three distinct chains here +so glycine violates this rule of + + align:start position:0% +so glycine violates this rule of + + + align:start position:0% +so glycine violates this rule of +chirality of left and right handedness + + align:start position:0% +chirality of left and right handedness + + + align:start position:0% +chirality of left and right handedness +and here by the way the side chain which + + align:start position:0% +and here by the way the side chain which + + + align:start position:0% +and here by the way the side chain which +in all of these cases is depicted as + + align:start position:0% +in all of these cases is depicted as + + + align:start position:0% +in all of these cases is depicted as +extending off to the right of each amino + + align:start position:0% +extending off to the right of each amino + + + align:start position:0% +extending off to the right of each amino +acid the side chain is simply an H + + align:start position:0% +acid the side chain is simply an H + + + align:start position:0% +acid the side chain is simply an H +simply a proton a hydrogen atom + + align:start position:0% +simply a proton a hydrogen atom + + + align:start position:0% +simply a proton a hydrogen atom +in fact what we see about these um amino + + align:start position:0% +in fact what we see about these um amino + + + align:start position:0% +in fact what we see about these um amino +acids is is that the side chains have + + align:start position:0% +acids is is that the side chains have + + + align:start position:0% +acids is is that the side chains have +quite distinct biochemical properties + + align:start position:0% +quite distinct biochemical properties + + + align:start position:0% +quite distinct biochemical properties +and that begins to impress us with the + + align:start position:0% +and that begins to impress us with the + + + align:start position:0% +and that begins to impress us with the +notion that proteins and their + + align:start position:0% +notion that proteins and their + + + align:start position:0% +notion that proteins and their +biochemical attributes can be dictated + + align:start position:0% +biochemical attributes can be dictated + + + align:start position:0% +biochemical attributes can be dictated +by the identities of the amino acids + + align:start position:0% +by the identities of the amino acids + + + align:start position:0% +by the identities of the amino acids +that are used to construct them + + align:start position:0% +that are used to construct them + + + align:start position:0% +that are used to construct them +we can talk about the notion of nonpolar + + align:start position:0% +we can talk about the notion of nonpolar + + + align:start position:0% +we can talk about the notion of nonpolar +versus polar amino acids I.E amino acids + + align:start position:0% +versus polar amino acids I.E amino acids + + + align:start position:0% +versus polar amino acids I.E amino acids +which have poor affinity for water they + + align:start position:0% +which have poor affinity for water they + + + align:start position:0% +which have poor affinity for water they +don't have a separation of plus and + + align:start position:0% +don't have a separation of plus and + + + align:start position:0% +don't have a separation of plus and +minus uh charges + + align:start position:0% +minus uh charges + + + align:start position:0% +minus uh charges +and as a consequence they're they're a + + align:start position:0% +and as a consequence they're they're a + + + align:start position:0% +and as a consequence they're they're a +little bit or quite a bit hydrophobic + + align:start position:0% +little bit or quite a bit hydrophobic + + + align:start position:0% +little bit or quite a bit hydrophobic +now you will say well how can they be + + align:start position:0% +now you will say well how can they be + + + align:start position:0% +now you will say well how can they be +hydrophobic because here this oxygen is + + align:start position:0% +hydrophobic because here this oxygen is + + + align:start position:0% +hydrophobic because here this oxygen is +charged and here this Amino this amine + + align:start position:0% +charged and here this Amino this amine + + + align:start position:0% +charged and here this Amino this amine +group is charged that would make it + + align:start position:0% +group is charged that would make it + + + align:start position:0% +group is charged that would make it +highly hydrophilic + + align:start position:0% +highly hydrophilic + + + align:start position:0% +highly hydrophilic +but keep in mind when I'm talking about + + align:start position:0% +but keep in mind when I'm talking about + + + align:start position:0% +but keep in mind when I'm talking about +these amino acids I'm not talking about + + align:start position:0% +these amino acids I'm not talking about + + + align:start position:0% +these amino acids I'm not talking about +them when they're in a single amino acid + + align:start position:0% +them when they're in a single amino acid + + + align:start position:0% +them when they're in a single amino acid +form I'm talking about their properties + + align:start position:0% +form I'm talking about their properties + + + align:start position:0% +form I'm talking about their properties +once they have been polymerized into a + + align:start position:0% +once they have been polymerized into a + + + align:start position:0% +once they have been polymerized into a +state like this and once they're + + align:start position:0% +state like this and once they're + + + align:start position:0% +state like this and once they're +polymerized into a state like this + + align:start position:0% +polymerized into a state like this + + + align:start position:0% +polymerized into a state like this +the the nh2 and Co charging that is the + + align:start position:0% +the the nh2 and Co charging that is the + + + align:start position:0% +the the nh2 and Co charging that is the +charge here and the charge here become + + align:start position:0% +charge here and the charge here become + + + align:start position:0% +charge here and the charge here become +irrelevant because this oxygen and this + + align:start position:0% +irrelevant because this oxygen and this + + + align:start position:0% +irrelevant because this oxygen and this +amine group are both tied up in covalent + + align:start position:0% +amine group are both tied up in covalent + + + align:start position:0% +amine group are both tied up in covalent +bonds and this acquisition of a proton + + align:start position:0% +bonds and this acquisition of a proton + + + align:start position:0% +bonds and this acquisition of a proton +and this shedding of an elect of a + + align:start position:0% +and this shedding of an elect of a + + + align:start position:0% +and this shedding of an elect of a +proton over here cannot occur because + + align:start position:0% +proton over here cannot occur because + + + align:start position:0% +proton over here cannot occur because +both of these atoms o and and N are + + align:start position:0% +both of these atoms o and and N are + + + align:start position:0% +both of these atoms o and and N are +involved in covalent bonds so therefore + + align:start position:0% +involved in covalent bonds so therefore + + + align:start position:0% +involved in covalent bonds so therefore +when we talk about uh um nonpolar and + + align:start position:0% +when we talk about uh um nonpolar and + + + align:start position:0% +when we talk about uh um nonpolar and +and polar amino acids keep in mind we're + + align:start position:0% +and polar amino acids keep in mind we're + + + align:start position:0% +and polar amino acids keep in mind we're +focusing on the biochemical properties + + align:start position:0% +focusing on the biochemical properties + + + align:start position:0% +focusing on the biochemical properties +of the side chain because the central + + align:start position:0% +of the side chain because the central + + + align:start position:0% +of the side chain because the central +backbone of the of the polypeptide and + + align:start position:0% +backbone of the of the polypeptide and + + + align:start position:0% +backbone of the of the polypeptide and +the central backbone is defined quite + + align:start position:0% +the central backbone is defined quite + + + align:start position:0% +the central backbone is defined quite +clearly here here's the central backbone + + align:start position:0% +clearly here here's the central backbone + + + align:start position:0% +clearly here here's the central backbone +and you see it has a a quite repeating + + align:start position:0% +and you see it has a a quite repeating + + + align:start position:0% +and you see it has a a quite repeating +structure NCC + + align:start position:0% +structure NCC + + + align:start position:0% +structure NCC +nccncc this is invariant + + align:start position:0% +nccncc this is invariant + + + align:start position:0% +nccncc this is invariant +what what changes and what defines the + + align:start position:0% +what what changes and what defines the + + + align:start position:0% +what what changes and what defines the +biochemical attributes of this + + align:start position:0% +biochemical attributes of this + + + align:start position:0% +biochemical attributes of this +oligopeptide or a polypeptide are the + + align:start position:0% +oligopeptide or a polypeptide are the + + + align:start position:0% +oligopeptide or a polypeptide are the +identities of these Sky chains which + + align:start position:0% +identities of these Sky chains which + + + align:start position:0% +identities of these Sky chains which +again are are plotted on this particular + + align:start position:0% +again are are plotted on this particular + + + align:start position:0% +again are are plotted on this particular +graph and you have a different version + + align:start position:0% +graph and you have a different version + + + align:start position:0% +graph and you have a different version +in your book off to the right + + align:start position:0% +in your book off to the right + + + align:start position:0% +in your book off to the right +here you see we have a proton a methyl + + align:start position:0% +here you see we have a proton a methyl + + + align:start position:0% +here you see we have a proton a methyl +group a valine + + align:start position:0% +group a valine + + + align:start position:0% +group a valine +a leucine and isoleucine and the + + align:start position:0% +a leucine and isoleucine and the + + + align:start position:0% +a leucine and isoleucine and the +differences between this suggests these + + align:start position:0% +differences between this suggests these + + + align:start position:0% +differences between this suggests these +are all quite + + align:start position:0% +are all quite + + + align:start position:0% +are all quite +aliphatic uh + + align:start position:0% +aliphatic uh + + + align:start position:0% +aliphatic uh +quite similar to the propane and and the + + align:start position:0% +quite similar to the propane and and the + + + align:start position:0% +quite similar to the propane and and the +um that we talked about last time or the + + align:start position:0% +um that we talked about last time or the + + + align:start position:0% +um that we talked about last time or the +hexane that is to say these are quite + + align:start position:0% +hexane that is to say these are quite + + + align:start position:0% +hexane that is to say these are quite +hydrophobic side groups and as such if + + align:start position:0% +hydrophobic side groups and as such if + + + align:start position:0% +hydrophobic side groups and as such if +there were a polypeptide we can imagine + + align:start position:0% +there were a polypeptide we can imagine + + + align:start position:0% +there were a polypeptide we can imagine +and you put the polypeptide in water you + + align:start position:0% +and you put the polypeptide in water you + + + align:start position:0% +and you put the polypeptide in water you +can imagine that these amino acids would + + align:start position:0% +can imagine that these amino acids would + + + align:start position:0% +can imagine that these amino acids would +not like to be directly confronting the + + align:start position:0% +not like to be directly confronting the + + + align:start position:0% +not like to be directly confronting the +water because of the fact that they're + + align:start position:0% +water because of the fact that they're + + + align:start position:0% +water because of the fact that they're +hydrophobic + + align:start position:0% +hydrophobic + + + align:start position:0% +hydrophobic +methionine is also a bit hydrophobic + + align:start position:0% +methionine is also a bit hydrophobic + + + align:start position:0% +methionine is also a bit hydrophobic +it's I I I'm I'm + + align:start position:0% +it's I I I'm I'm + + + align:start position:0% +it's I I I'm I'm +equivocating there because the S has a + + align:start position:0% +equivocating there because the S has a + + + align:start position:0% +equivocating there because the S has a +slight degree of hydrophilicity uh has a + + align:start position:0% +slight degree of hydrophilicity uh has a + + + align:start position:0% +slight degree of hydrophilicity uh has a +slight uh degree of polarity but not + + align:start position:0% +slight uh degree of polarity but not + + + align:start position:0% +slight uh degree of polarity but not +really that much and these aromatic side + + align:start position:0% +really that much and these aromatic side + + + align:start position:0% +really that much and these aromatic side +chains here because they have these + + align:start position:0% +chains here because they have these + + + align:start position:0% +chains here because they have these +Benzene rings and then they're + + align:start position:0% +Benzene rings and then they're + + + align:start position:0% +Benzene rings and then they're +consequently called aromatic these are + + align:start position:0% +consequently called aromatic these are + + + align:start position:0% +consequently called aromatic these are +quite High strongly hydrophobic so they + + align:start position:0% +quite High strongly hydrophobic so they + + + align:start position:0% +quite High strongly hydrophobic so they +really hate to be in the uh in Intimate + + align:start position:0% +really hate to be in the uh in Intimate + + + align:start position:0% +really hate to be in the uh in Intimate +contact with water + + align:start position:0% +contact with water + + + align:start position:0% +contact with water +here on the other hand let's look at + + align:start position:0% +here on the other hand let's look at + + + align:start position:0% +here on the other hand let's look at +these side chains because + + align:start position:0% +these side chains because + + + align:start position:0% +these side chains because +here we have uh strongly uh polar + + align:start position:0% +here we have uh strongly uh polar + + + align:start position:0% +here we have uh strongly uh polar +molecules side chains again keep in mind + + align:start position:0% +molecules side chains again keep in mind + + + align:start position:0% +molecules side chains again keep in mind +we're focusing on the side chains here + + align:start position:0% +we're focusing on the side chains here + + + align:start position:0% +we're focusing on the side chains here +we see searing with a hydroxyl group + + align:start position:0% +we see searing with a hydroxyl group + + + align:start position:0% +we see searing with a hydroxyl group +that can form hydrogen bonds with the + + align:start position:0% +that can form hydrogen bonds with the + + + align:start position:0% +that can form hydrogen bonds with the +water threonine which has its own + + align:start position:0% +water threonine which has its own + + + align:start position:0% +water threonine which has its own +hydroxyl group + + align:start position:0% +hydroxyl group + + + align:start position:0% +hydroxyl group +asparagine which has two atoms here this + + align:start position:0% +asparagine which has two atoms here this + + + align:start position:0% +asparagine which has two atoms here this +carbonyl and the nh2 both of which can + + align:start position:0% +carbonyl and the nh2 both of which can + + + align:start position:0% +carbonyl and the nh2 both of which can +form hydrogen bonds uh to the with the + + align:start position:0% +form hydrogen bonds uh to the with the + + + align:start position:0% +form hydrogen bonds uh to the with the +water as can glutamine + + align:start position:0% +water as can glutamine + + + align:start position:0% +water as can glutamine +so these are quite hydrophilic they're + + align:start position:0% +so these are quite hydrophilic they're + + + align:start position:0% +so these are quite hydrophilic they're +not as + + align:start position:0% +not as + + + align:start position:0% +not as +fanatically hydrophilic as these charge + + align:start position:0% +fanatically hydrophilic as these charge + + + align:start position:0% +fanatically hydrophilic as these charge +molecules where the side chains are not + + align:start position:0% +molecules where the side chains are not + + + align:start position:0% +molecules where the side chains are not +just capable of forming hydrogen bonds + + align:start position:0% +just capable of forming hydrogen bonds + + + align:start position:0% +just capable of forming hydrogen bonds +in this lower group here the side chains + + align:start position:0% +in this lower group here the side chains + + + align:start position:0% +in this lower group here the side chains +are capable of undergoing ionization so + + align:start position:0% +are capable of undergoing ionization so + + + align:start position:0% +are capable of undergoing ionization so +they're actually strongly charged and + + align:start position:0% +they're actually strongly charged and + + + align:start position:0% +they're actually strongly charged and +here we see uh here the carboxyl group + + align:start position:0% +here we see uh here the carboxyl group + + + align:start position:0% +here we see uh here the carboxyl group +and the glue in this group in our + + align:start position:0% +and the glue in this group in our + + + align:start position:0% +and the glue in this group in our +spartic and glutamic acid has actually + + align:start position:0% +spartic and glutamic acid has actually + + + align:start position:0% +spartic and glutamic acid has actually +discharged its proton becoming + + align:start position:0% +discharged its proton becoming + + + align:start position:0% +discharged its proton becoming +negatively charged + + align:start position:0% +negatively charged + + + align:start position:0% +negatively charged +these are acidic amino acids by virtue + + align:start position:0% +these are acidic amino acids by virtue + + + align:start position:0% +these are acidic amino acids by virtue +of the carboxyl groups they have basic + + align:start position:0% +of the carboxyl groups they have basic + + + align:start position:0% +of the carboxyl groups they have basic +amino acids here um arginine lysine and + + align:start position:0% +amino acids here um arginine lysine and + + + align:start position:0% +amino acids here um arginine lysine and +histidine all acquire a positively + + align:start position:0% +histidine all acquire a positively + + + align:start position:0% +histidine all acquire a positively +charged side Chain by virtue of these + + align:start position:0% +charged side Chain by virtue of these + + + align:start position:0% +charged side Chain by virtue of these +nitrogens here which have a strong + + align:start position:0% +nitrogens here which have a strong + + + align:start position:0% +nitrogens here which have a strong +affinity for pulling away protons for + + align:start position:0% +affinity for pulling away protons for + + + align:start position:0% +affinity for pulling away protons for +abstracting protons from the aqueous + + align:start position:0% +abstracting protons from the aqueous + + + align:start position:0% +abstracting protons from the aqueous +solvent + + align:start position:0% +solvent + + + align:start position:0% +solvent +and so we have a whole gradient of + + align:start position:0% +and so we have a whole gradient of + + + align:start position:0% +and so we have a whole gradient of +of hydrophilicity down to + + align:start position:0% +of hydrophilicity down to + + + align:start position:0% +of hydrophilicity down to +hydrophobicity and here we have + + align:start position:0% +hydrophobicity and here we have + + + align:start position:0% +hydrophobicity and here we have +intermediate structures + + align:start position:0% +intermediate structures + + + align:start position:0% +intermediate structures +we also have some very special + + align:start position:0% +we also have some very special + + + align:start position:0% +we also have some very special +idiosyncratic kinds of amino acids here + + align:start position:0% +idiosyncratic kinds of amino acids here + + + align:start position:0% +idiosyncratic kinds of amino acids here +is tyrosine and tyrosine is a little bit + + align:start position:0% +is tyrosine and tyrosine is a little bit + + + align:start position:0% +is tyrosine and tyrosine is a little bit +schizophrenic again it has this highly + + align:start position:0% +schizophrenic again it has this highly + + + align:start position:0% +schizophrenic again it has this highly +hydrophobic aromatic group here the + + align:start position:0% +hydrophobic aromatic group here the + + + align:start position:0% +hydrophobic aromatic group here the +Benzene ring which hates to be in water + + align:start position:0% +Benzene ring which hates to be in water + + + align:start position:0% +Benzene ring which hates to be in water +and the hydroxyl group which actually is + + align:start position:0% +and the hydroxyl group which actually is + + + align:start position:0% +and the hydroxyl group which actually is +a friend of water so here we have + + align:start position:0% +a friend of water so here we have + + + align:start position:0% +a friend of water so here we have +something where its role is is quite + + align:start position:0% +something where its role is is quite + + + align:start position:0% +something where its role is is quite +equivocal + + align:start position:0% +equivocal + + + align:start position:0% +equivocal +here we have cysteine as indicated here + + align:start position:0% +here we have cysteine as indicated here + + + align:start position:0% +here we have cysteine as indicated here +and what's interesting about the + + align:start position:0% +and what's interesting about the + + + align:start position:0% +and what's interesting about the +cysteine group in this case is the sh + + align:start position:0% +cysteine group in this case is the sh + + + align:start position:0% +cysteine group in this case is the sh +group the side chain the sh group + + align:start position:0% +group the side chain the sh group + + + align:start position:0% +group the side chain the sh group +because this sh group is able to form uh + + align:start position:0% +because this sh group is able to form uh + + + align:start position:0% +because this sh group is able to form uh +bonds with yet other sh groups from + + align:start position:0% +bonds with yet other sh groups from + + + align:start position:0% +bonds with yet other sh groups from +other cysteines + + align:start position:0% +other cysteines + + + align:start position:0% +other cysteines +so let's just look at this cysteine here + + align:start position:0% +so let's just look at this cysteine here + + + align:start position:0% +so let's just look at this cysteine here +for a moment you see there's a ch2 and + + align:start position:0% +for a moment you see there's a ch2 and + + + align:start position:0% +for a moment you see there's a ch2 and +then there's an sh so let's imagine I'm + + align:start position:0% +then there's an sh so let's imagine I'm + + + align:start position:0% +then there's an sh so let's imagine I'm +not going to draw all the atoms here but + + align:start position:0% +not going to draw all the atoms here but + + + align:start position:0% +not going to draw all the atoms here but +let's imagine here we have the ch2 group + + align:start position:0% +let's imagine here we have the ch2 group + + + align:start position:0% +let's imagine here we have the ch2 group +I'm not drawing the backbone sh over + + align:start position:0% +I'm not drawing the backbone sh over + + + align:start position:0% +I'm not drawing the backbone sh over +here and we could imagine another + + align:start position:0% +here and we could imagine another + + + align:start position:0% +here and we could imagine another +protein chain another polypeptide chain + + align:start position:0% +protein chain another polypeptide chain + + + align:start position:0% +protein chain another polypeptide chain +down here again I'm not drawing the + + align:start position:0% +down here again I'm not drawing the + + + align:start position:0% +down here again I'm not drawing the +backbone + + align:start position:0% +backbone + + + align:start position:0% +backbone +but I'm drawing another sh like this + + align:start position:0% +but I'm drawing another sh like this + + + align:start position:0% +but I'm drawing another sh like this +and the fact is under the conditions of + + align:start position:0% +and the fact is under the conditions of + + + align:start position:0% +and the fact is under the conditions of +oxidation and reduction that operate in + + align:start position:0% +oxidation and reduction that operate in + + + align:start position:0% +oxidation and reduction that operate in +the at least in the extracellular space + + align:start position:0% +the at least in the extracellular space + + + align:start position:0% +the at least in the extracellular space +one can oxidize this these two resulting + + align:start position:0% +one can oxidize this these two resulting + + + align:start position:0% +one can oxidize this these two resulting +in the formation of what is known as a + + align:start position:0% +in the formation of what is known as a + + + align:start position:0% +in the formation of what is known as a +disulfide bond + + align:start position:0% + + + + align:start position:0% + +so here we have now for the first notion + + align:start position:0% +so here we have now for the first notion + + + align:start position:0% +so here we have now for the first notion +uh idea at the time the notion that + + align:start position:0% +uh idea at the time the notion that + + + align:start position:0% +uh idea at the time the notion that +polypeptide chains can be covalently + + align:start position:0% +polypeptide chains can be covalently + + + align:start position:0% +polypeptide chains can be covalently +linked one another through these + + align:start position:0% +linked one another through these + + + align:start position:0% +linked one another through these +cross-linked crosslinks as indicated + + align:start position:0% +cross-linked crosslinks as indicated + + + align:start position:0% +cross-linked crosslinks as indicated +here + + align:start position:0% +here + + + align:start position:0% +here +conversely if you add a reducing agent + + align:start position:0% +conversely if you add a reducing agent + + + align:start position:0% +conversely if you add a reducing agent +that will add protons back to this and + + align:start position:0% +that will add protons back to this and + + + align:start position:0% +that will add protons back to this and +reduce the oxidation state of the + + align:start position:0% +reduce the oxidation state of the + + + align:start position:0% +reduce the oxidation state of the +sulfurs once again causing the disulfide + + align:start position:0% +sulfurs once again causing the disulfide + + + align:start position:0% +sulfurs once again causing the disulfide +bond to fall apart + + align:start position:0% +bond to fall apart + + + align:start position:0% +bond to fall apart +now in principle these disulfide bonds + + align:start position:0% +now in principle these disulfide bonds + + + align:start position:0% +now in principle these disulfide bonds +could be used to link two proteins + + align:start position:0% +could be used to link two proteins + + + align:start position:0% +could be used to link two proteins +together + + align:start position:0% +together + + + align:start position:0% +together +but more often than not if you look at + + align:start position:0% +but more often than not if you look at + + + align:start position:0% +but more often than not if you look at +the structure of a of a single protein + + align:start position:0% +the structure of a of a single protein + + + align:start position:0% +the structure of a of a single protein +protein here's the structure of a single + + align:start position:0% +protein here's the structure of a single + + + align:start position:0% +protein here's the structure of a single +protein and often there are + + align:start position:0% +protein and often there are + + + align:start position:0% +protein and often there are +intramolecular + + align:start position:0% + + + + align:start position:0% + +bonds disulfide bonds High e bonds from + + align:start position:0% +bonds disulfide bonds High e bonds from + + + align:start position:0% +bonds disulfide bonds High e bonds from +one domain of the protein to another + + align:start position:0% +one domain of the protein to another + + + align:start position:0% +one domain of the protein to another +from one part of the protein to the + + align:start position:0% +from one part of the protein to the + + + align:start position:0% +from one part of the protein to the +other I'll draw them in right here here + + align:start position:0% +other I'll draw them in right here here + + + align:start position:0% +other I'll draw them in right here here +might be a disulfide bond here might be + + align:start position:0% +might be a disulfide bond here might be + + + align:start position:0% +might be a disulfide bond here might be +adult sulfide Bond and I could go on and + + align:start position:0% +adult sulfide Bond and I could go on and + + + align:start position:0% +adult sulfide Bond and I could go on and +on there might be another one over here + + align:start position:0% +on there might be another one over here + + + align:start position:0% +on there might be another one over here +why do we have these disulfide bonds + + align:start position:0% +why do we have these disulfide bonds + + + align:start position:0% +why do we have these disulfide bonds +because as we'll indicate very shortly + + align:start position:0% +because as we'll indicate very shortly + + + align:start position:0% +because as we'll indicate very shortly +the three-dimensional structure of a + + align:start position:0% +the three-dimensional structure of a + + + align:start position:0% +the three-dimensional structure of a +protein is very specifically determined + + align:start position:0% +protein is very specifically determined + + + align:start position:0% +protein is very specifically determined +a protein can only function when it + + align:start position:0% +a protein can only function when it + + + align:start position:0% +a protein can only function when it +assumes a certain three-dimensional + + align:start position:0% +assumes a certain three-dimensional + + + align:start position:0% +assumes a certain three-dimensional +configuration when it assumes assumes a + + align:start position:0% +configuration when it assumes assumes a + + + align:start position:0% +configuration when it assumes assumes a +certain three-dimensional uh + + align:start position:0% +certain three-dimensional uh + + + align:start position:0% +certain three-dimensional uh +stereochemical + + align:start position:0% +stereochemical + + + align:start position:0% +stereochemical +configuration + + align:start position:0% +configuration + + + align:start position:0% +configuration +when we talk about stereochemistry we're + + align:start position:0% +when we talk about stereochemistry we're + + + align:start position:0% +when we talk about stereochemistry we're +talking about the three-dimensional + + align:start position:0% +talking about the three-dimensional + + + align:start position:0% +talking about the three-dimensional +structures of molecules small and large + + align:start position:0% +structures of molecules small and large + + + align:start position:0% +structures of molecules small and large +and here we begin to touch on a theme of + + align:start position:0% +and here we begin to touch on a theme of + + + align:start position:0% +and here we begin to touch on a theme of +how these complex polypeptide chains are + + align:start position:0% +how these complex polypeptide chains are + + + align:start position:0% +how these complex polypeptide chains are +able to create proteins that have very + + align:start position:0% +able to create proteins that have very + + + align:start position:0% +able to create proteins that have very +specific often very rigid structures in + + align:start position:0% +specific often very rigid structures in + + + align:start position:0% +specific often very rigid structures in +three-dimensional space + + align:start position:0% +three-dimensional space + + + align:start position:0% +three-dimensional space +part of this structural rigidity is + + align:start position:0% +part of this structural rigidity is + + + align:start position:0% +part of this structural rigidity is +maintained by these covalent + + align:start position:0% +maintained by these covalent + + + align:start position:0% +maintained by these covalent +disulfide bonds which link tightly link + + align:start position:0% +disulfide bonds which link tightly link + + + align:start position:0% +disulfide bonds which link tightly link +neighboring regions or even not so + + align:start position:0% +neighboring regions or even not so + + + align:start position:0% +neighboring regions or even not so +neighboring regions of a single + + align:start position:0% +neighboring regions of a single + + + align:start position:0% +neighboring regions of a single +polypeptide chain these intramolecular + + align:start position:0% +polypeptide chain these intramolecular + + + align:start position:0% +polypeptide chain these intramolecular +links this doesn't preclude they're + + align:start position:0% +links this doesn't preclude they're + + + align:start position:0% +links this doesn't preclude they're +being intermolecular links between two + + align:start position:0% +being intermolecular links between two + + + align:start position:0% +being intermolecular links between two +polypeptide chains that are mediated as + + align:start position:0% +polypeptide chains that are mediated as + + + align:start position:0% +polypeptide chains that are mediated as +well by the disulfide bonds here's + + align:start position:0% +well by the disulfide bonds here's + + + align:start position:0% +well by the disulfide bonds here's +another very peculiar amino acid + + align:start position:0% +another very peculiar amino acid + + + align:start position:0% +another very peculiar amino acid +because what you see here is that the + + align:start position:0% +because what you see here is that the + + + align:start position:0% +because what you see here is that the +side chain which is ch2 ch2ch2 is + + align:start position:0% +side chain which is ch2 ch2ch2 is + + + align:start position:0% +side chain which is ch2 ch2ch2 is +hydrogen bonded here to the amine group + + align:start position:0% +hydrogen bonded here to the amine group + + + align:start position:0% +hydrogen bonded here to the amine group +it's not swinging out in free space it's + + align:start position:0% +it's not swinging out in free space it's + + + align:start position:0% +it's not swinging out in free space it's +I'm + + align:start position:0% +I'm + + + align:start position:0% +I'm +I misspoke + + align:start position:0% +I misspoke + + + align:start position:0% +I misspoke +what we see here is ch2ch2a is + + align:start position:0% +what we see here is ch2ch2a is + + + align:start position:0% +what we see here is ch2ch2a is +covalently bonded to the amine group you + + align:start position:0% +covalently bonded to the amine group you + + + align:start position:0% +covalently bonded to the amine group you +pick that up right + + align:start position:0% +pick that up right + + + align:start position:0% +pick that up right +I was just testing you sure I was okay + + align:start position:0% +I was just testing you sure I was okay + + + align:start position:0% +I was just testing you sure I was okay +so here we see a five-membered ring + + align:start position:0% +so here we see a five-membered ring + + + align:start position:0% +so here we see a five-membered ring +that's created + + align:start position:0% +that's created + + + align:start position:0% +that's created +so here this thing is not free swing out + + align:start position:0% +so here this thing is not free swing out + + + align:start position:0% +so here this thing is not free swing out +in free space it creates a five-membered + + align:start position:0% +in free space it creates a five-membered + + + align:start position:0% +in free space it creates a five-membered +ring coat where the end of the side + + align:start position:0% +ring coat where the end of the side + + + align:start position:0% +ring coat where the end of the side +chain is actually covalently linked to + + align:start position:0% +chain is actually covalently linked to + + + align:start position:0% +chain is actually covalently linked to +the amino group and that also has + + align:start position:0% +the amino group and that also has + + + align:start position:0% +the amino group and that also has +implications for the structure of + + align:start position:0% +implications for the structure of + + + align:start position:0% +implications for the structure of +proteins because this particular amino + + align:start position:0% +proteins because this particular amino + + + align:start position:0% +proteins because this particular amino +acid whenever it occurs within a + + align:start position:0% +acid whenever it occurs within a + + + align:start position:0% +acid whenever it occurs within a +polypeptide chain doesn't have the + + align:start position:0% +polypeptide chain doesn't have the + + + align:start position:0% +polypeptide chain doesn't have the +flexibility of assuming certain + + align:start position:0% +flexibility of assuming certain + + + align:start position:0% +flexibility of assuming certain +configurations that the other ones have + + align:start position:0% +configurations that the other ones have + + + align:start position:0% +configurations that the other ones have +who's whose four side chains are not so + + align:start position:0% +who's whose four side chains are not so + + + align:start position:0% +who's whose four side chains are not so +encumbered + + align:start position:0% +encumbered + + + align:start position:0% +encumbered +none of them has total flexibility but + + align:start position:0% +none of them has total flexibility but + + + align:start position:0% +none of them has total flexibility but +this one is far more encumbered in the + + align:start position:0% +this one is far more encumbered in the + + + align:start position:0% +this one is far more encumbered in the +in the kinds of three-dimensional + + align:start position:0% +in the kinds of three-dimensional + + + align:start position:0% +in the kinds of three-dimensional +structures that it can assume + + align:start position:0% +structures that it can assume + + + align:start position:0% +structures that it can assume +and um with that in mind we begin to ask + + align:start position:0% +and um with that in mind we begin to ask + + + align:start position:0% +and um with that in mind we begin to ask +questions about how uh polypeptide + + align:start position:0% +questions about how uh polypeptide + + + align:start position:0% +questions about how uh polypeptide +chains assume three-dimensional + + align:start position:0% +chains assume three-dimensional + + + align:start position:0% +chains assume three-dimensional +structure uh if we talk about a + + align:start position:0% +structure uh if we talk about a + + + align:start position:0% +structure uh if we talk about a +polypeptide chain + + align:start position:0% +polypeptide chain + + + align:start position:0% +polypeptide chain +in our minds + + align:start position:0% +in our minds + + + align:start position:0% +in our minds +hopefully + + align:start position:0% +hopefully + + + align:start position:0% +hopefully +there's only 28 combinations + + align:start position:0% + + + + align:start position:0% + +oh am I good or what okay anyhow + + align:start position:0% +oh am I good or what okay anyhow + + + align:start position:0% +oh am I good or what okay anyhow +all right so look here and here you see + + align:start position:0% +all right so look here and here you see + + + align:start position:0% +all right so look here and here you see +this is a typical polypeptide chain + + align:start position:0% +this is a typical polypeptide chain + + + align:start position:0% +this is a typical polypeptide chain +here we have a three a three letter code + + align:start position:0% +here we have a three a three letter code + + + align:start position:0% +here we have a three a three letter code +in truth there's a there's a single + + align:start position:0% +in truth there's a there's a single + + + align:start position:0% +in truth there's a there's a single +letter code which was introduced around + + align:start position:0% +letter code which was introduced around + + + align:start position:0% +letter code which was introduced around +1965 so each each of the 20 amino acids + + align:start position:0% +1965 so each each of the 20 amino acids + + + align:start position:0% +1965 so each each of the 20 amino acids +has its own single letter code + + align:start position:0% +has its own single letter code + + + align:start position:0% +has its own single letter code +and to make a Frank + + align:start position:0% +and to make a Frank + + + align:start position:0% +and to make a Frank +and + + align:start position:0% +and + + + align:start position:0% +and +depressing admission + + align:start position:0% +depressing admission + + + align:start position:0% +depressing admission +35 years 40 years after the single amino + + align:start position:0% +35 years 40 years after the single amino + + + align:start position:0% +35 years 40 years after the single amino +acid letter code was instituted I still + + align:start position:0% +acid letter code was instituted I still + + + align:start position:0% +acid letter code was instituted I still +haven't learned it + + align:start position:0% +haven't learned it + + + align:start position:0% +haven't learned it +but we can learn these three letter + + align:start position:0% +but we can learn these three letter + + + align:start position:0% +but we can learn these three letter +codes which fortunately are present here + + align:start position:0% +codes which fortunately are present here + + + align:start position:0% +codes which fortunately are present here +where in the single letter code L is + + align:start position:0% +where in the single letter code L is + + + align:start position:0% +where in the single letter code L is +leucine and uh a is art a is alanine see + + align:start position:0% +leucine and uh a is art a is alanine see + + + align:start position:0% +leucine and uh a is art a is alanine see +they know it + + align:start position:0% +they know it + + + align:start position:0% +they know it +this is another example of not being + + align:start position:0% +this is another example of not being + + + align:start position:0% +this is another example of not being +able to teach Old Dogs new tricks anyhow + + align:start position:0% +able to teach Old Dogs new tricks anyhow + + + align:start position:0% +able to teach Old Dogs new tricks anyhow +so here we see uh the way One Way by + + align:start position:0% +so here we see uh the way One Way by + + + align:start position:0% +so here we see uh the way One Way by +which one might depict enemies or amino + + align:start position:0% +which one might depict enemies or amino + + + align:start position:0% +which one might depict enemies or amino +acid and keeping amino acid chain a + + align:start position:0% +acid and keeping amino acid chain a + + + align:start position:0% +acid and keeping amino acid chain a +polypeptide chain and keep in mind this + + align:start position:0% +polypeptide chain and keep in mind this + + + align:start position:0% +polypeptide chain and keep in mind this +can go on indefinitely + + align:start position:0% +can go on indefinitely + + + align:start position:0% +can go on indefinitely +as we begin to wrestle with the + + align:start position:0% +as we begin to wrestle with the + + + align:start position:0% +as we begin to wrestle with the +three-dimensional structure of the chain + + align:start position:0% +three-dimensional structure of the chain + + + align:start position:0% +three-dimensional structure of the chain +we begin to realize the following and + + align:start position:0% +we begin to realize the following and + + + align:start position:0% +we begin to realize the following and +that is that after the chain is + + align:start position:0% +that is that after the chain is + + + align:start position:0% +that is that after the chain is +initially synthesized it's initially + + align:start position:0% +initially synthesized it's initially + + + align:start position:0% +initially synthesized it's initially +chaotic and as it extends it + + align:start position:0% +chaotic and as it extends it + + + align:start position:0% +chaotic and as it extends it +increasingly begins to assume a very + + align:start position:0% +increasingly begins to assume a very + + + align:start position:0% +increasingly begins to assume a very +specific + + align:start position:0% +specific + + + align:start position:0% +specific +uh molecular three-dimensional molecular + + align:start position:0% +uh molecular three-dimensional molecular + + + align:start position:0% +uh molecular three-dimensional molecular +configuration which is indicated down + + align:start position:0% +configuration which is indicated down + + + align:start position:0% +configuration which is indicated down +here so the chaos that operates uh + + align:start position:0% +here so the chaos that operates uh + + + align:start position:0% +here so the chaos that operates uh +initially will eventually result in a a + + align:start position:0% +initially will eventually result in a a + + + align:start position:0% +initially will eventually result in a a +native configuration over here which in + + align:start position:0% +native configuration over here which in + + + align:start position:0% +native configuration over here which in +many respects often represents the + + align:start position:0% +many respects often represents the + + + align:start position:0% +many respects often represents the +lowest free energy state + + align:start position:0% +lowest free energy state + + + align:start position:0% +lowest free energy state +since for the last 40 years people have + + align:start position:0% +since for the last 40 years people have + + + align:start position:0% +since for the last 40 years people have +been able to have been trying to figure + + align:start position:0% +been able to have been trying to figure + + + align:start position:0% +been able to have been trying to figure +out if you knew the amino acid sequence + + align:start position:0% +out if you knew the amino acid sequence + + + align:start position:0% +out if you knew the amino acid sequence +of this primary polypeptide here if you + + align:start position:0% +of this primary polypeptide here if you + + + align:start position:0% +of this primary polypeptide here if you +knew its primary structure and when I + + align:start position:0% +knew its primary structure and when I + + + align:start position:0% +knew its primary structure and when I +say primary structure what I mean is the + + align:start position:0% +say primary structure what I mean is the + + + align:start position:0% +say primary structure what I mean is the +sequence of the amino acids so if you + + align:start position:0% +sequence of the amino acids so if you + + + align:start position:0% +sequence of the amino acids so if you +knew the primary structure of the amino + + align:start position:0% +knew the primary structure of the amino + + + align:start position:0% +knew the primary structure of the amino +acids you should in principle be able to + + align:start position:0% +acids you should in principle be able to + + + align:start position:0% +acids you should in principle be able to +develop a computer algorithm that would + + align:start position:0% +develop a computer algorithm that would + + + align:start position:0% +develop a computer algorithm that would +predict the three-dimensional + + align:start position:0% +predict the three-dimensional + + + align:start position:0% +predict the three-dimensional +configuration which is shown here in a + + align:start position:0% +configuration which is shown here in a + + + align:start position:0% +configuration which is shown here in a +very schematic way and which we'll + + align:start position:0% +very schematic way and which we'll + + + align:start position:0% +very schematic way and which we'll +discuss in much greater detail shortly + + align:start position:0% +discuss in much greater detail shortly + + + align:start position:0% +discuss in much greater detail shortly +and the fact is after 40 Years of trying + + align:start position:0% +and the fact is after 40 Years of trying + + + align:start position:0% +and the fact is after 40 Years of trying +one still is unable to do that I.E if I + + align:start position:0% +one still is unable to do that I.E if I + + + align:start position:0% +one still is unable to do that I.E if I +were to give the three the primary amino + + align:start position:0% +were to give the three the primary amino + + + align:start position:0% +were to give the three the primary amino +acid sequence of a polypeptide to the + + align:start position:0% +acid sequence of a polypeptide to the + + + align:start position:0% +acid sequence of a polypeptide to the +smartest biochemist in the world and + + align:start position:0% +smartest biochemist in the world and + + + align:start position:0% +smartest biochemist in the world and +there are some very smart ones he or she + + align:start position:0% +there are some very smart ones he or she + + + align:start position:0% +there are some very smart ones he or she +could still not tell me what the + + align:start position:0% +could still not tell me what the + + + align:start position:0% +could still not tell me what the +three-dimensional structure of this + + align:start position:0% +three-dimensional structure of this + + + align:start position:0% +three-dimensional structure of this +protein with uh total certainly would be + + align:start position:0% +protein with uh total certainly would be + + + align:start position:0% +protein with uh total certainly would be +uh why because there's an almost + + align:start position:0% +uh why because there's an almost + + + align:start position:0% +uh why because there's an almost +infinite number of intramolecular + + align:start position:0% +infinite number of intramolecular + + + align:start position:0% +infinite number of intramolecular +interactions that greatly complicate + + align:start position:0% +interactions that greatly complicate + + + align:start position:0% +interactions that greatly complicate +how the protein assumes this structure + + align:start position:0% +how the protein assumes this structure + + + align:start position:0% +how the protein assumes this structure +moreover if we talk at this as the + + align:start position:0% +moreover if we talk at this as the + + + align:start position:0% +moreover if we talk at this as the +native state of the protein we can + + align:start position:0% +native state of the protein we can + + + align:start position:0% +native state of the protein we can +imagine that there's ways of disrupting + + align:start position:0% +imagine that there's ways of disrupting + + + align:start position:0% +imagine that there's ways of disrupting +that because much of this native state + + align:start position:0% +that because much of this native state + + + align:start position:0% +that because much of this native state +is created by intramolecular hydrogen + + align:start position:0% +is created by intramolecular hydrogen + + + align:start position:0% +is created by intramolecular hydrogen +bonds remember the hydrogen bonds are + + align:start position:0% +bonds remember the hydrogen bonds are + + + align:start position:0% +bonds remember the hydrogen bonds are +relatively weak and if we heat up the um + + align:start position:0% +relatively weak and if we heat up the um + + + align:start position:0% +relatively weak and if we heat up the um +the the temperature then we can break + + align:start position:0% +the the temperature then we can break + + + align:start position:0% +the the temperature then we can break +hydrogen bonds and therefore every time + + align:start position:0% +hydrogen bonds and therefore every time + + + align:start position:0% +hydrogen bonds and therefore every time +we uh we fry an egg for example if we + + align:start position:0% +we uh we fry an egg for example if we + + + align:start position:0% +we uh we fry an egg for example if we +want to get down to earth we denature we + + align:start position:0% +want to get down to earth we denature we + + + align:start position:0% +want to get down to earth we denature we +break up the three-dimensional the + + align:start position:0% +break up the three-dimensional the + + + align:start position:0% +break up the three-dimensional the +native three-dimensional structure of + + align:start position:0% +native three-dimensional structure of + + + align:start position:0% +native three-dimensional structure of +the albumin molecules that constitute + + align:start position:0% +the albumin molecules that constitute + + + align:start position:0% +the albumin molecules that constitute +the egg white and so when everything + + align:start position:0% +the egg white and so when everything + + + align:start position:0% +the egg white and so when everything +turns white what we've done is to take a + + align:start position:0% +turns white what we've done is to take a + + + align:start position:0% +turns white what we've done is to take a +native molecule like this + + align:start position:0% +native molecule like this + + + align:start position:0% +native molecule like this +heated it up to temperatures where the + + align:start position:0% +heated it up to temperatures where the + + + align:start position:0% +heated it up to temperatures where the +intramolecular bonds no longer stabilize + + align:start position:0% +intramolecular bonds no longer stabilize + + + align:start position:0% +intramolecular bonds no longer stabilize +notably hydrogen bonds no longer + + align:start position:0% +notably hydrogen bonds no longer + + + align:start position:0% +notably hydrogen bonds no longer +stabilize this three-dimensional + + align:start position:0% +stabilize this three-dimensional + + + align:start position:0% +stabilize this three-dimensional +configuration and we put it into a + + align:start position:0% +configuration and we put it into a + + + align:start position:0% +configuration and we put it into a +denatured state which might be all the + + align:start position:0% +denatured state which might be all the + + + align:start position:0% +denatured state which might be all the +way up here + + align:start position:0% +way up here + + + align:start position:0% +way up here +and therefore it this acquisition of a + + align:start position:0% +and therefore it this acquisition of a + + + align:start position:0% +and therefore it this acquisition of a +native configuration or a native state + + align:start position:0% +native configuration or a native state + + + align:start position:0% +native configuration or a native state +native representing the natural state + + align:start position:0% +native representing the natural state + + + align:start position:0% +native representing the natural state +is also reversible in many molecules + + align:start position:0% +is also reversible in many molecules + + + align:start position:0% +is also reversible in many molecules +simply by heating them up there are to + + align:start position:0% +simply by heating them up there are to + + + align:start position:0% +simply by heating them up there are to +be sure yet other molecules which are + + align:start position:0% +be sure yet other molecules which are + + + align:start position:0% +be sure yet other molecules which are +different from egg white from the + + align:start position:0% +different from egg white from the + + + align:start position:0% +different from egg white from the +albumin in egg white where if you cool + + align:start position:0% +albumin in egg white where if you cool + + + align:start position:0% +albumin in egg white where if you cool +them back down they'll spontaneously + + align:start position:0% +them back down they'll spontaneously + + + align:start position:0% +them back down they'll spontaneously +reassume their native structure many + + align:start position:0% +reassume their native structure many + + + align:start position:0% +reassume their native structure many +proteins most will not do so + + align:start position:0% +proteins most will not do so + + + align:start position:0% +proteins most will not do so +well how again let's go back to this + + align:start position:0% +well how again let's go back to this + + + align:start position:0% +well how again let's go back to this +issue of the acquisition of complex + + align:start position:0% +issue of the acquisition of complex + + + align:start position:0% +issue of the acquisition of complex +three-dimensional structure and here we + + align:start position:0% +three-dimensional structure and here we + + + align:start position:0% +three-dimensional structure and here we +begin to see how some of this + + align:start position:0% +begin to see how some of this + + + align:start position:0% +begin to see how some of this +um + + align:start position:0% +um + + + align:start position:0% +um +structure is acquired and stabilized + + align:start position:0% +structure is acquired and stabilized + + + align:start position:0% +structure is acquired and stabilized +through these intramolecular hydrogen + + align:start position:0% +through these intramolecular hydrogen + + + align:start position:0% +through these intramolecular hydrogen +bonds and there are many opportunities + + align:start position:0% +bonds and there are many opportunities + + + align:start position:0% +bonds and there are many opportunities +for these intramolecular hydrogen bonds + + align:start position:0% +for these intramolecular hydrogen bonds + + + align:start position:0% +for these intramolecular hydrogen bonds +because here we see one polypeptide + + align:start position:0% +because here we see one polypeptide + + + align:start position:0% +because here we see one polypeptide +chain here we see another + + align:start position:0% +chain here we see another + + + align:start position:0% +chain here we see another +and we see that the nh2 group right here + + align:start position:0% +and we see that the nh2 group right here + + + align:start position:0% +and we see that the nh2 group right here +I'm sorry the the nitrogen group here + + align:start position:0% +I'm sorry the the nitrogen group here + + + align:start position:0% +I'm sorry the the nitrogen group here +with with the proton side chain + + align:start position:0% +with with the proton side chain + + + align:start position:0% +with with the proton side chain +and the carbonyl group here with the + + align:start position:0% +and the carbonyl group here with the + + + align:start position:0% +and the carbonyl group here with the +oxygen are not encumbered they are in + + align:start position:0% +oxygen are not encumbered they are in + + + align:start position:0% +oxygen are not encumbered they are in +principle available to form hydrogen + + align:start position:0% +principle available to form hydrogen + + + align:start position:0% +principle available to form hydrogen +bonds with a polypeptide chain somewhere + + align:start position:0% +bonds with a polypeptide chain somewhere + + + align:start position:0% +bonds with a polypeptide chain somewhere +else now this other polypeptide chain + + align:start position:0% +else now this other polypeptide chain + + + align:start position:0% +else now this other polypeptide chain +could once again be from another protein + + align:start position:0% +could once again be from another protein + + + align:start position:0% +could once again be from another protein +from another polypeptide + + align:start position:0% +from another polypeptide + + + align:start position:0% +from another polypeptide +but more often than not we're once again + + align:start position:0% +but more often than not we're once again + + + align:start position:0% +but more often than not we're once again +dealing with intramolecular + + align:start position:0% +dealing with intramolecular + + + align:start position:0% +dealing with intramolecular +crosslinks but in this case the + + align:start position:0% +crosslinks but in this case the + + + align:start position:0% +crosslinks but in this case the +intramolecular crosslinks are not + + align:start position:0% +intramolecular crosslinks are not + + + align:start position:0% +intramolecular crosslinks are not +disulfide Bonds which are covalent and + + align:start position:0% +disulfide Bonds which are covalent and + + + align:start position:0% +disulfide Bonds which are covalent and +hard as stable as a rock in the absence + + align:start position:0% +hard as stable as a rock in the absence + + + align:start position:0% +hard as stable as a rock in the absence +of reducing agents here we're talking + + align:start position:0% +of reducing agents here we're talking + + + align:start position:0% +of reducing agents here we're talking +about much weaker bonds hydrogen bonds + + align:start position:0% +about much weaker bonds hydrogen bonds + + + align:start position:0% +about much weaker bonds hydrogen bonds +which also act between + + align:start position:0% +which also act between + + + align:start position:0% +which also act between +different Loops of the protein and serve + + align:start position:0% +different Loops of the protein and serve + + + align:start position:0% +different Loops of the protein and serve +once again to stabilize the + + align:start position:0% +once again to stabilize the + + + align:start position:0% +once again to stabilize the +three-dimensional structure of the + + align:start position:0% +three-dimensional structure of the + + + align:start position:0% +three-dimensional structure of the +native state of the protein + + align:start position:0% +native state of the protein + + + align:start position:0% +native state of the protein +and you can see how these these + + align:start position:0% +and you can see how these these + + + align:start position:0% +and you can see how these these +opportunities for forming multiple + + align:start position:0% +opportunities for forming multiple + + + align:start position:0% +opportunities for forming multiple +hydrogen bonds can create an enormous + + align:start position:0% +hydrogen bonds can create an enormous + + + align:start position:0% +hydrogen bonds can create an enormous +degree of stability + + align:start position:0% +degree of stability + + + align:start position:0% +degree of stability +and here are some examples of what we + + align:start position:0% +and here are some examples of what we + + + align:start position:0% +and here are some examples of what we +now call the secondary structure of the + + align:start position:0% +now call the secondary structure of the + + + align:start position:0% +now call the secondary structure of the +protein + + align:start position:0% +protein + + + align:start position:0% +protein +just a second ago or several minutes ago + + align:start position:0% +just a second ago or several minutes ago + + + align:start position:0% +just a second ago or several minutes ago +to be honest and I'm always honest with + + align:start position:0% +to be honest and I'm always honest with + + + align:start position:0% +to be honest and I'm always honest with +you class + + align:start position:0% +you class + + + align:start position:0% +you class +the primary structure is the amino acid + + align:start position:0% +the primary structure is the amino acid + + + align:start position:0% +the primary structure is the amino acid +sequence the secondary structure + + align:start position:0% +sequence the secondary structure + + + align:start position:0% +sequence the secondary structure +represents configurations like this here + + align:start position:0% +represents configurations like this here + + + align:start position:0% +represents configurations like this here +is an alpha helix + + align:start position:0% +is an alpha helix + + + align:start position:0% +is an alpha helix +here is a beta pleated sheet and what we + + align:start position:0% +here is a beta pleated sheet and what we + + + align:start position:0% +here is a beta pleated sheet and what we +see here in this Alpha Helix is we have + + align:start position:0% +see here in this Alpha Helix is we have + + + align:start position:0% +see here in this Alpha Helix is we have +a helical structure where the amine + + align:start position:0% +a helical structure where the amine + + + align:start position:0% +a helical structure where the amine +group down here the NH hydrogen bonds + + align:start position:0% +group down here the NH hydrogen bonds + + + align:start position:0% +group down here the NH hydrogen bonds +with a residue which is I think three + + align:start position:0% +with a residue which is I think three + + + align:start position:0% +with a residue which is I think three +and a half residues Upstream one two + + align:start position:0% +and a half residues Upstream one two + + + align:start position:0% +and a half residues Upstream one two +there's an amine down there so with a + + align:start position:0% +there's an amine down there so with a + + + align:start position:0% +there's an amine down there so with a +carbonyl group that's three and a half + + align:start position:0% +carbonyl group that's three and a half + + + align:start position:0% +carbonyl group that's three and a half +residues uh Upstream of it this one once + + align:start position:0% +residues uh Upstream of it this one once + + + align:start position:0% +residues uh Upstream of it this one once +again reaches three and a half uh + + align:start position:0% +again reaches three and a half uh + + + align:start position:0% +again reaches three and a half uh +residues Upstream not all the hydrogen + + align:start position:0% +residues Upstream not all the hydrogen + + + align:start position:0% +residues Upstream not all the hydrogen +bonds are shown in the background only + + align:start position:0% +bonds are shown in the background only + + + align:start position:0% +bonds are shown in the background only +the ones on on our side of the Helix are + + align:start position:0% +the ones on on our side of the Helix are + + + align:start position:0% +the ones on on our side of the Helix are +shown on the front side of the Helix but + + align:start position:0% +shown on the front side of the Helix but + + + align:start position:0% +shown on the front side of the Helix but +you can imagine that this can perpetuate + + align:start position:0% +you can imagine that this can perpetuate + + + align:start position:0% +you can imagine that this can perpetuate +itself and each of these carbonyls May + + align:start position:0% +itself and each of these carbonyls May + + + align:start position:0% +itself and each of these carbonyls May +associate with a proton + + align:start position:0% +associate with a proton + + + align:start position:0% +associate with a proton +from an NH group that's either above or + + align:start position:0% +from an NH group that's either above or + + + align:start position:0% +from an NH group that's either above or +below that particular residue and this + + align:start position:0% +below that particular residue and this + + + align:start position:0% +below that particular residue and this +in turn can create a helical structure + + align:start position:0% +in turn can create a helical structure + + + align:start position:0% +in turn can create a helical structure +by the way Proline doesn't fit well in + + align:start position:0% +by the way Proline doesn't fit well in + + + align:start position:0% +by the way Proline doesn't fit well in +in this if you add a ProLine in here + + align:start position:0% +in this if you add a ProLine in here + + + align:start position:0% +in this if you add a ProLine in here +Proline is known in the trade as a helix + + align:start position:0% +Proline is known in the trade as a helix + + + align:start position:0% +Proline is known in the trade as a helix +breaker + + align:start position:0% +breaker + + + align:start position:0% +breaker +why because it cannot twist itself + + align:start position:0% +why because it cannot twist itself + + + align:start position:0% +why because it cannot twist itself +around to form an alpha Helix and so if + + align:start position:0% +around to form an alpha Helix and so if + + + align:start position:0% +around to form an alpha Helix and so if +the primary amino acid were to dictate + + align:start position:0% +the primary amino acid were to dictate + + + align:start position:0% +the primary amino acid were to dictate +that a ProLine would be inserted right + + align:start position:0% +that a ProLine would be inserted right + + + align:start position:0% +that a ProLine would be inserted right +here for example then this Helix might + + align:start position:0% +here for example then this Helix might + + + align:start position:0% +here for example then this Helix might +exist down below and up above but it + + align:start position:0% +exist down below and up above but it + + + align:start position:0% +exist down below and up above but it +would not be continuous because the + + align:start position:0% +would not be continuous because the + + + align:start position:0% +would not be continuous because the +presence of a ProLine is highly + + align:start position:0% +presence of a ProLine is highly + + + align:start position:0% +presence of a ProLine is highly +disruptive of the formation of + + align:start position:0% +disruptive of the formation of + + + align:start position:0% +disruptive of the formation of +and Alpha helix this means that in + + align:start position:0% +and Alpha helix this means that in + + + align:start position:0% +and Alpha helix this means that in +principle you can make some predictions + + align:start position:0% +principle you can make some predictions + + + align:start position:0% +principle you can make some predictions +about the localized structure of a + + align:start position:0% +about the localized structure of a + + + align:start position:0% +about the localized structure of a +polypeptide by knowing whether or not + + align:start position:0% +polypeptide by knowing whether or not + + + align:start position:0% +polypeptide by knowing whether or not +Proline is present for example but that + + align:start position:0% +Proline is present for example but that + + + align:start position:0% +Proline is present for example but that +still doesn't give you the power to + + align:start position:0% +still doesn't give you the power to + + + align:start position:0% +still doesn't give you the power to +predict the entire three-dimensional + + align:start position:0% +predict the entire three-dimensional + + + align:start position:0% +predict the entire three-dimensional +structure of the finished protein itself + + align:start position:0% +structure of the finished protein itself + + + align:start position:0% +structure of the finished protein itself +now let's uh agree that this is the + + align:start position:0% +now let's uh agree that this is the + + + align:start position:0% +now let's uh agree that this is the +secondary structure of the protein I.E + + align:start position:0% +secondary structure of the protein I.E + + + align:start position:0% +secondary structure of the protein I.E +the various domains which often form + + align:start position:0% +the various domains which often form + + + align:start position:0% +the various domains which often form +Alpha helices within a certain segment + + align:start position:0% +Alpha helices within a certain segment + + + align:start position:0% +Alpha helices within a certain segment +of the protein or a certain segment of + + align:start position:0% +of the protein or a certain segment of + + + align:start position:0% +of the protein or a certain segment of +the protein will form beta pleated + + align:start position:0% +the protein will form beta pleated + + + align:start position:0% +the protein will form beta pleated +sheets and there's several are several + + align:start position:0% +sheets and there's several are several + + + align:start position:0% +sheets and there's several are several +other less common kinds of of a + + align:start position:0% +other less common kinds of of a + + + align:start position:0% +other less common kinds of of a +secondary structure and here we deal + + align:start position:0% +secondary structure and here we deal + + + align:start position:0% +secondary structure and here we deal +with tertiary structure now we're + + align:start position:0% +with tertiary structure now we're + + + align:start position:0% +with tertiary structure now we're +getting really interesting or maybe you + + align:start position:0% +getting really interesting or maybe you + + + align:start position:0% +getting really interesting or maybe you +don't like it but some people say it's + + align:start position:0% +don't like it but some people say it's + + + align:start position:0% +don't like it but some people say it's +really interesting because here are the + + align:start position:0% +really interesting because here are the + + + align:start position:0% +really interesting because here are the +tertiary structures of some arbitrarily + + align:start position:0% +tertiary structures of some arbitrarily + + + align:start position:0% +tertiary structures of some arbitrarily +chosen proteins + + align:start position:0% +chosen proteins + + + align:start position:0% +chosen proteins +here the tertiary structure of this + + align:start position:0% +here the tertiary structure of this + + + align:start position:0% +here the tertiary structure of this +particular protein and there and the + + align:start position:0% +particular protein and there and the + + + align:start position:0% +particular protein and there and the +identities have not are these are not + + align:start position:0% +identities have not are these are not + + + align:start position:0% +identities have not are these are not +given in our textbook and I'm sure if we + + align:start position:0% +given in our textbook and I'm sure if we + + + align:start position:0% +given in our textbook and I'm sure if we +spent two or three weeks we could find + + align:start position:0% +spent two or three weeks we could find + + + align:start position:0% +spent two or three weeks we could find +out what they were but anyhow here is a + + align:start position:0% +out what they were but anyhow here is a + + + align:start position:0% +out what they were but anyhow here is a +protein a three-dimensional structure of + + align:start position:0% +protein a three-dimensional structure of + + + align:start position:0% +protein a three-dimensional structure of +a protein + + align:start position:0% +a protein + + + align:start position:0% +a protein +where which is composed of four Alpha + + align:start position:0% +where which is composed of four Alpha + + + align:start position:0% +where which is composed of four Alpha +helices which go up another Alfie + + align:start position:0% +helices which go up another Alfie + + + align:start position:0% +helices which go up another Alfie +Alpha Helix Alpha Helix Alpha Helix + + align:start position:0% +Alpha Helix Alpha Helix Alpha Helix + + + align:start position:0% +Alpha Helix Alpha Helix Alpha Helix +Alpha Helix they're depicted here + + align:start position:0% +Alpha Helix they're depicted here + + + align:start position:0% +Alpha Helix they're depicted here +fortunately in four different colors + + align:start position:0% +fortunately in four different colors + + + align:start position:0% +fortunately in four different colors +and so we see that when we talk about + + align:start position:0% +and so we see that when we talk about + + + align:start position:0% +and so we see that when we talk about +tertiary structure we're talking about + + align:start position:0% +tertiary structure we're talking about + + + align:start position:0% +tertiary structure we're talking about +how the alpha helices are disposed with + + align:start position:0% +how the alpha helices are disposed with + + + align:start position:0% +how the alpha helices are disposed with +respect to one another + + align:start position:0% +respect to one another + + + align:start position:0% +respect to one another +the primary structures the amino acid + + align:start position:0% +the primary structures the amino acid + + + align:start position:0% +the primary structures the amino acid +sequence is not shown here the secondary + + align:start position:0% +sequence is not shown here the secondary + + + align:start position:0% +sequence is not shown here the secondary +structure represents these individual + + align:start position:0% +structure represents these individual + + + align:start position:0% +structure represents these individual +Alpha helices and the tertiary structure + + align:start position:0% +Alpha helices and the tertiary structure + + + align:start position:0% +Alpha helices and the tertiary structure +represents how these Alpha helices are + + align:start position:0% +represents how these Alpha helices are + + + align:start position:0% +represents how these Alpha helices are +arranged vis-a-vis one another here is a + + align:start position:0% +arranged vis-a-vis one another here is a + + + align:start position:0% +arranged vis-a-vis one another here is a +a protein which is structured much + + align:start position:0% +a protein which is structured much + + + align:start position:0% +a protein which is structured much +differently um + + align:start position:0% +differently um + + + align:start position:0% +differently um +here this is is uh + + align:start position:0% +here this is is uh + + + align:start position:0% +here this is is uh +is formed of many beta-plated sheets we + + align:start position:0% +is formed of many beta-plated sheets we + + + align:start position:0% +is formed of many beta-plated sheets we +saw them in the in the last figure in + + align:start position:0% +saw them in the in the last figure in + + + align:start position:0% +saw them in the in the last figure in +the last overhead you see it has a quite + + align:start position:0% +the last overhead you see it has a quite + + + align:start position:0% +the last overhead you see it has a quite +different uh overall three-dimensional + + align:start position:0% +different uh overall three-dimensional + + + align:start position:0% +different uh overall three-dimensional +structure + + align:start position:0% +structure + + + align:start position:0% +structure +this could be the beginning of an alpha + + align:start position:0% +this could be the beginning of an alpha + + + align:start position:0% +this could be the beginning of an alpha +Helix down here although that's quite + + align:start position:0% +Helix down here although that's quite + + + align:start position:0% +Helix down here although that's quite +equivocal + + align:start position:0% +equivocal + + + align:start position:0% +equivocal +and here we see yet another point and + + align:start position:0% +and here we see yet another point and + + + align:start position:0% +and here we see yet another point and +that is that as we said before the + + align:start position:0% +that is that as we said before the + + + align:start position:0% +that is that as we said before the +tertiary structure independent of these + + align:start position:0% +tertiary structure independent of these + + + align:start position:0% +tertiary structure independent of these +Alpha and beta Alpha helices and beta + + align:start position:0% +Alpha and beta Alpha helices and beta + + + align:start position:0% +Alpha and beta Alpha helices and beta +pleated Chase may be stabilized by these + + align:start position:0% +pleated Chase may be stabilized by these + + + align:start position:0% +pleated Chase may be stabilized by these +covalent inter strand crosslinks formed + + align:start position:0% +covalent inter strand crosslinks formed + + + align:start position:0% +covalent inter strand crosslinks formed +by the uh cysteines + + align:start position:0% +by the uh cysteines + + + align:start position:0% +by the uh cysteines +and in the end if we put all that + + align:start position:0% +and in the end if we put all that + + + align:start position:0% +and in the end if we put all that +together then we come to the realization + + align:start position:0% +together then we come to the realization + + + align:start position:0% +together then we come to the realization +that the three-dimensional structure of + + align:start position:0% +that the three-dimensional structure of + + + align:start position:0% +that the three-dimensional structure of +a protein as determined by the art of + + align:start position:0% +a protein as determined by the art of + + + align:start position:0% +a protein as determined by the art of +x-ray + + align:start position:0% + + + + align:start position:0% + +there we go + + align:start position:0% +there we go + + + align:start position:0% +there we go +I'm not actually dyslexic + + align:start position:0% +I'm not actually dyslexic + + + align:start position:0% +I'm not actually dyslexic +I actually have a cousin who I won't + + align:start position:0% +I actually have a cousin who I won't + + + align:start position:0% +I actually have a cousin who I won't +mention whose son was so dyslexic that + + align:start position:0% +mention whose son was so dyslexic that + + + align:start position:0% +mention whose son was so dyslexic that +when he came to stairways he didn't know + + align:start position:0% +when he came to stairways he didn't know + + + align:start position:0% +when he came to stairways he didn't know +whether to put his foot up or down now + + align:start position:0% +whether to put his foot up or down now + + + align:start position:0% +whether to put his foot up or down now +that's difficulty this is + + align:start position:0% +that's difficulty this is + + + align:start position:0% +that's difficulty this is +this is not so bad okay anyhow + + align:start position:0% +this is not so bad okay anyhow + + + align:start position:0% +this is not so bad okay anyhow +because I solved it within less than two + + align:start position:0% +because I solved it within less than two + + + align:start position:0% +because I solved it within less than two +minutes time all right so here we see + + align:start position:0% +minutes time all right so here we see + + + align:start position:0% +minutes time all right so here we see +this is what the three-dimensional + + align:start position:0% +this is what the three-dimensional + + + align:start position:0% +this is what the three-dimensional +structure of a protein looks like this + + align:start position:0% +structure of a protein looks like this + + + align:start position:0% +structure of a protein looks like this +is called a space filling model because + + align:start position:0% +is called a space filling model because + + + align:start position:0% +is called a space filling model because +here one draws in as determined by x-ray + + align:start position:0% +here one draws in as determined by x-ray + + + align:start position:0% +here one draws in as determined by x-ray +crystallography what the ACT if we could + + align:start position:0% +crystallography what the ACT if we could + + + align:start position:0% +crystallography what the ACT if we could +see what a protein looks like what it + + align:start position:0% +see what a protein looks like what it + + + align:start position:0% +see what a protein looks like what it +actually must look like where each of + + align:start position:0% +actually must look like where each of + + + align:start position:0% +actually must look like where each of +the the atoms in including these side + + align:start position:0% +the the atoms in including these side + + + align:start position:0% +the the atoms in including these side +chains is actually depicted before when + + align:start position:0% +chains is actually depicted before when + + + align:start position:0% +chains is actually depicted before when +we use these far more schematic + + align:start position:0% +we use these far more schematic + + + align:start position:0% +we use these far more schematic +descriptions like here we were just + + align:start position:0% +descriptions like here we were just + + + align:start position:0% +descriptions like here we were just +talking about the overall structure of + + align:start position:0% +talking about the overall structure of + + + align:start position:0% +talking about the overall structure of +the backbone we weren't really + + align:start position:0% +the backbone we weren't really + + + align:start position:0% +the backbone we weren't really +indicating where the side chains were + + align:start position:0% +indicating where the side chains were + + + align:start position:0% +indicating where the side chains were +and what space they would fill up and if + + align:start position:0% +and what space they would fill up and if + + + align:start position:0% +and what space they would fill up and if +we give them the chance if we put in all + + align:start position:0% +we give them the chance if we put in all + + + align:start position:0% +we give them the chance if we put in all +of the um other atoms the side chains + + align:start position:0% +of the um other atoms the side chains + + + align:start position:0% +of the um other atoms the side chains +and we create a space filling molecule a + + align:start position:0% +and we create a space filling molecule a + + + align:start position:0% +and we create a space filling molecule a +model where the the actual atoms are + + align:start position:0% +model where the the actual atoms are + + + align:start position:0% +model where the the actual atoms are +shown this is what the protein would + + align:start position:0% +shown this is what the protein would + + + align:start position:0% +shown this is what the protein would +look like and the fact of the matter is + + align:start position:0% +look like and the fact of the matter is + + + align:start position:0% +look like and the fact of the matter is +that virtually all proteins have very + + align:start position:0% +that virtually all proteins have very + + + align:start position:0% +that virtually all proteins have very +specific structures it's not as if they + + align:start position:0% +specific structures it's not as if they + + + align:start position:0% +specific structures it's not as if they +can shift from one structure to another + + align:start position:0% +can shift from one structure to another + + + align:start position:0% +can shift from one structure to another +once they leave their normal native + + align:start position:0% +once they leave their normal native + + + align:start position:0% +once they leave their normal native +structure they will lose their ability + + align:start position:0% +structure they will lose their ability + + + align:start position:0% +structure they will lose their ability +to um to do what Their normal jobs are + + align:start position:0% +to um to do what Their normal jobs are + + + align:start position:0% +to um to do what Their normal jobs are +and this particular uh overhead happens + + align:start position:0% +and this particular uh overhead happens + + + align:start position:0% +and this particular uh overhead happens +to bring in yet another theme that we're + + align:start position:0% +to bring in yet another theme that we're + + + align:start position:0% +to bring in yet another theme that we're +going to focus on increasingly which is + + align:start position:0% +going to focus on increasingly which is + + + align:start position:0% +going to focus on increasingly which is +what do proteins do in cells I'm glad I + + align:start position:0% +what do proteins do in cells I'm glad I + + + align:start position:0% +what do proteins do in cells I'm glad I +asked that question one of the things + + align:start position:0% +asked that question one of the things + + + align:start position:0% +asked that question one of the things +they do is they act as catalysts IES + + align:start position:0% +they do is they act as catalysts IES + + + align:start position:0% +they do is they act as catalysts IES +enzymes + + align:start position:0% +enzymes + + + align:start position:0% +enzymes +the fact is as we'll discuss later + + align:start position:0% +the fact is as we'll discuss later + + + align:start position:0% +the fact is as we'll discuss later +virtually all biochemical reactions + + align:start position:0% +virtually all biochemical reactions + + + align:start position:0% +virtually all biochemical reactions +require an enzyme Catalyst in order to + + align:start position:0% +require an enzyme Catalyst in order to + + + align:start position:0% +require an enzyme Catalyst in order to +propel them forward that is to say if + + align:start position:0% +propel them forward that is to say if + + + align:start position:0% +propel them forward that is to say if +there's a biochemical reaction to occur + + align:start position:0% +there's a biochemical reaction to occur + + + align:start position:0% +there's a biochemical reaction to occur +almost always it will not occur + + align:start position:0% +almost always it will not occur + + + align:start position:0% +almost always it will not occur +spontaneously the same way that a + + align:start position:0% +spontaneously the same way that a + + + align:start position:0% +spontaneously the same way that a +hydroxyl ion and a hydrogen will join + + align:start position:0% +hydroxyl ion and a hydrogen will join + + + align:start position:0% +hydroxyl ion and a hydrogen will join +together spontaneously in water almost + + align:start position:0% +together spontaneously in water almost + + + align:start position:0% +together spontaneously in water almost +all biochemical reactions require the + + align:start position:0% +all biochemical reactions require the + + + align:start position:0% +all biochemical reactions require the +mediation of an enzyme + + align:start position:0% +mediation of an enzyme + + + align:start position:0% +mediation of an enzyme +which is a biological catalyst in order + + align:start position:0% +which is a biological catalyst in order + + + align:start position:0% +which is a biological catalyst in order +to encourage this to happen and this + + align:start position:0% +to encourage this to happen and this + + + align:start position:0% +to encourage this to happen and this +biological and almost all catalysts in + + align:start position:0% +biological and almost all catalysts in + + + align:start position:0% +biological and almost all catalysts in +in our cells are proteins + + align:start position:0% +in our cells are proteins + + + align:start position:0% +in our cells are proteins +so if you have uh 4 326 distinct + + align:start position:0% +so if you have uh 4 326 distinct + + + align:start position:0% +so if you have uh 4 326 distinct +biochemical uh reactions occurring in + + align:start position:0% +biochemical uh reactions occurring in + + + align:start position:0% +biochemical uh reactions occurring in +the cell that means that there's + + align:start position:0% +the cell that means that there's + + + align:start position:0% +the cell that means that there's +probably almost as many distinct enzymes + + align:start position:0% +probably almost as many distinct enzymes + + + align:start position:0% +probably almost as many distinct enzymes +each one of which is assigned to mediate + + align:start position:0% +each one of which is assigned to mediate + + + align:start position:0% +each one of which is assigned to mediate +one or another of those distinct uh + + align:start position:0% +one or another of those distinct uh + + + align:start position:0% +one or another of those distinct uh +biochemical reactions and here we see + + align:start position:0% +biochemical reactions and here we see + + + align:start position:0% +biochemical reactions and here we see +the fact this is an um an enzyme which + + align:start position:0% +the fact this is an um an enzyme which + + + align:start position:0% +the fact this is an um an enzyme which +happens to be called hexokinase recall + + align:start position:0% +happens to be called hexokinase recall + + + align:start position:0% +happens to be called hexokinase recall +that the ASE suffix at the end dictates + + align:start position:0% +that the ASE suffix at the end dictates + + + align:start position:0% +that the ASE suffix at the end dictates +uh that this is already an enzyme rather + + align:start position:0% +uh that this is already an enzyme rather + + + align:start position:0% +uh that this is already an enzyme rather +than a than a carbohydrate and this + + align:start position:0% +than a than a carbohydrate and this + + + align:start position:0% +than a than a carbohydrate and this +attaches uh in fact a phosphate group + + align:start position:0% +attaches uh in fact a phosphate group + + + align:start position:0% +attaches uh in fact a phosphate group +onto glucose and what happens is is that + + align:start position:0% +onto glucose and what happens is is that + + + align:start position:0% +onto glucose and what happens is is that +the glucose which is the substrate which + + align:start position:0% +the glucose which is the substrate which + + + align:start position:0% +the glucose which is the substrate which +is acted upon by the catalyst is pulled + + align:start position:0% +is acted upon by the catalyst is pulled + + + align:start position:0% +is acted upon by the catalyst is pulled +into this site + + align:start position:0% +into this site + + + align:start position:0% +into this site +in the protein which is highly + + align:start position:0% +in the protein which is highly + + + align:start position:0% +in the protein which is highly +specialized to mediate the enzymatic + + align:start position:0% +specialized to mediate the enzymatic + + + align:start position:0% +specialized to mediate the enzymatic +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +almost all of the business of this + + align:start position:0% +almost all of the business of this + + + align:start position:0% +almost all of the business of this +complex enzyme is carried out right here + + align:start position:0% +complex enzyme is carried out right here + + + align:start position:0% +complex enzyme is carried out right here +and somehow a lot of the other amino + + align:start position:0% +and somehow a lot of the other amino + + + align:start position:0% +and somehow a lot of the other amino +acids that are located at a distance are + + align:start position:0% +acids that are located at a distance are + + + align:start position:0% +acids that are located at a distance are +doing other things like regulating the + + align:start position:0% +doing other things like regulating the + + + align:start position:0% +doing other things like regulating the +activity of the enzyme but the actual + + align:start position:0% +activity of the enzyme but the actual + + + align:start position:0% +activity of the enzyme but the actual +business end of the enzyme is present in + + align:start position:0% +business end of the enzyme is present in + + + align:start position:0% +business end of the enzyme is present in +what is called a catalytic cleft an + + align:start position:0% +what is called a catalytic cleft an + + + align:start position:0% +what is called a catalytic cleft an +active site of this enzyme in which the + + align:start position:0% +active site of this enzyme in which the + + + align:start position:0% +active site of this enzyme in which the +substrates are pulled in and are + + align:start position:0% +substrates are pulled in and are + + + align:start position:0% +substrates are pulled in and are +manipulated and changed chemically by + + align:start position:0% +manipulated and changed chemically by + + + align:start position:0% +manipulated and changed chemically by +the actions of of this particular enzyme + + align:start position:0% +the actions of of this particular enzyme + + + align:start position:0% +the actions of of this particular enzyme +now in saying that that virtually all + + align:start position:0% +now in saying that that virtually all + + + align:start position:0% +now in saying that that virtually all +catalysts but not all are proteins + + align:start position:0% +catalysts but not all are proteins + + + align:start position:0% +catalysts but not all are proteins +I also mean to say that proteins have a + + align:start position:0% +I also mean to say that proteins have a + + + align:start position:0% +I also mean to say that proteins have a +second major function in the body the + + align:start position:0% +second major function in the body the + + + align:start position:0% +second major function in the body the +first major function is to act as + + align:start position:0% +first major function is to act as + + + align:start position:0% +first major function is to act as +enzymes and catalysts the second major + + align:start position:0% +enzymes and catalysts the second major + + + align:start position:0% +enzymes and catalysts the second major +function is to create biochemical + + align:start position:0% +function is to create biochemical + + + align:start position:0% +function is to create biochemical +structures I.E structures of different + + align:start position:0% +structures I.E structures of different + + + align:start position:0% +structures I.E structures of different +cytoskeleton proteins such as I showed + + align:start position:0% +cytoskeleton proteins such as I showed + + + align:start position:0% +cytoskeleton proteins such as I showed +you uh uh two lectures ago and so we're + + align:start position:0% +you uh uh two lectures ago and so we're + + + align:start position:0% +you uh uh two lectures ago and so we're +going to come repeatedly to situations + + align:start position:0% +going to come repeatedly to situations + + + align:start position:0% +going to come repeatedly to situations +where uh complex structural entities in + + align:start position:0% +where uh complex structural entities in + + + align:start position:0% +where uh complex structural entities in +the cell are composed of different + + align:start position:0% +the cell are composed of different + + + align:start position:0% +the cell are composed of different +structural proteins again this is just a + + align:start position:0% +structural proteins again this is just a + + + align:start position:0% +structural proteins again this is just a +Prelude to be talking about these in + + align:start position:0% +Prelude to be talking about these in + + + align:start position:0% +Prelude to be talking about these in +Greater details these two major + + align:start position:0% +Greater details these two major + + + align:start position:0% +Greater details these two major +functions of enzymatic catalysis on the + + align:start position:0% +functions of enzymatic catalysis on the + + + align:start position:0% +functions of enzymatic catalysis on the +one hand and creating structure on the + + align:start position:0% +one hand and creating structure on the + + + align:start position:0% +one hand and creating structure on the +other + + align:start position:0% +other + + + align:start position:0% +other +and so now we get to really four + + align:start position:0% +and so now we get to really four + + + align:start position:0% +and so now we get to really four +hierarchical levels of protein structure + + align:start position:0% +hierarchical levels of protein structure + + + align:start position:0% +hierarchical levels of protein structure +the primary uh + + align:start position:0% +the primary uh + + + align:start position:0% +the primary uh +the primary structure is the amino acid + + align:start position:0% +the primary structure is the amino acid + + + align:start position:0% +the primary structure is the amino acid +sequence + + align:start position:0% +sequence + + + align:start position:0% +sequence +and if we dwell for a second on this + + align:start position:0% +and if we dwell for a second on this + + + align:start position:0% +and if we dwell for a second on this +amino acid sequence let's realize that + + align:start position:0% +amino acid sequence let's realize that + + + align:start position:0% +amino acid sequence let's realize that +any single amino acid can follow any + + align:start position:0% +any single amino acid can follow any + + + align:start position:0% +any single amino acid can follow any +other amino acid so what that means is + + align:start position:0% +other amino acid so what that means is + + + align:start position:0% +other amino acid so what that means is +that if glycine is the first amino acid + + align:start position:0% +that if glycine is the first amino acid + + + align:start position:0% +that if glycine is the first amino acid +as it happens to be here serine is only + + align:start position:0% +as it happens to be here serine is only + + + align:start position:0% +as it happens to be here serine is only +one of 20 different possible second + + align:start position:0% +one of 20 different possible second + + + align:start position:0% +one of 20 different possible second +amino acids + + align:start position:0% +amino acids + + + align:start position:0% +amino acids +Spar aspartic acid is only um + + align:start position:0% +Spar aspartic acid is only um + + + align:start position:0% +Spar aspartic acid is only um +one of 20 different third amino acids as + + align:start position:0% +one of 20 different third amino acids as + + + align:start position:0% +one of 20 different third amino acids as +the third residue we often call these + + align:start position:0% +the third residue we often call these + + + align:start position:0% +the third residue we often call these +different residues the first residue + + align:start position:0% +different residues the first residue + + + align:start position:0% +different residues the first residue +second residue third residue fourth + + align:start position:0% +second residue third residue fourth + + + align:start position:0% +second residue third residue fourth +residue and fourth and so forth and keep + + align:start position:0% +residue and fourth and so forth and keep + + + align:start position:0% +residue and fourth and so forth and keep +in mind if we think about the + + align:start position:0% +in mind if we think about the + + + align:start position:0% +in mind if we think about the +combinatorial implications of that + + align:start position:0% +combinatorial implications of that + + + align:start position:0% +combinatorial implications of that +the first amino acid residue can have 20 + + align:start position:0% +the first amino acid residue can have 20 + + + align:start position:0% +the first amino acid residue can have 20 +different ones the second can have 20 + + align:start position:0% +different ones the second can have 20 + + + align:start position:0% +different ones the second can have 20 +different identities the third can have + + align:start position:0% +different identities the third can have + + + align:start position:0% +different identities the third can have +20 different identities that means if we + + align:start position:0% +20 different identities that means if we + + + align:start position:0% +20 different identities that means if we +make a + + align:start position:0% +make a + + + align:start position:0% +make a +a tripeptide a tripeptide has three + + align:start position:0% +a tripeptide a tripeptide has three + + + align:start position:0% +a tripeptide a tripeptide has three +amino acids in it that means we can make + + align:start position:0% +amino acids in it that means we can make + + + align:start position:0% +amino acids in it that means we can make +400 dipeptides + + align:start position:0% +400 dipeptides + + + align:start position:0% +400 dipeptides +400 distinct dipeptides with uh and we + + align:start position:0% +400 distinct dipeptides with uh and we + + + align:start position:0% +400 distinct dipeptides with uh and we +can make eight thousand distinct + + align:start position:0% +can make eight thousand distinct + + + align:start position:0% +can make eight thousand distinct +tripeptides + + align:start position:0% +tripeptides + + + align:start position:0% +tripeptides +now if you imagine that um there are + + align:start position:0% +now if you imagine that um there are + + + align:start position:0% +now if you imagine that um there are +that the average amino acid uh the the + + align:start position:0% +that the average amino acid uh the the + + + align:start position:0% +that the average amino acid uh the the +average protein in a cell is let's say + + align:start position:0% +average protein in a cell is let's say + + + align:start position:0% +average protein in a cell is let's say +150 amino acid residues long + + align:start position:0% +150 amino acid residues long + + + align:start position:0% +150 amino acid residues long +that means that in principle one could + + align:start position:0% +that means that in principle one could + + + align:start position:0% +that means that in principle one could +make + + align:start position:0% +make + + + align:start position:0% +make +uh 20 to the 150th power + + align:start position:0% +uh 20 to the 150th power + + + align:start position:0% +uh 20 to the 150th power +distinct + + align:start position:0% +distinct + + + align:start position:0% +distinct +amino acid sequences because of these + + align:start position:0% +amino acid sequences because of these + + + align:start position:0% +amino acid sequences because of these +absence of any constraints of what which + + align:start position:0% +absence of any constraints of what which + + + align:start position:0% +absence of any constraints of what which +amino acid will follow which other amino + + align:start position:0% +amino acid will follow which other amino + + + align:start position:0% +amino acid will follow which other amino +acids + + align:start position:0% +acids + + + align:start position:0% +acids +in other words if the average + + align:start position:0% +in other words if the average + + + align:start position:0% +in other words if the average +uh polypeptide has this many residues + + align:start position:0% +uh polypeptide has this many residues + + + align:start position:0% +uh polypeptide has this many residues +this is the number of distinct 150 amino + + align:start position:0% +this is the number of distinct 150 amino + + + align:start position:0% +this is the number of distinct 150 amino +acid residue long proteins that one + + align:start position:0% +acid residue long proteins that one + + + align:start position:0% +acid residue long proteins that one +could in principle synthesize + + align:start position:0% +could in principle synthesize + + + align:start position:0% +could in principle synthesize +I'm not saying all of them have ever + + align:start position:0% +I'm not saying all of them have ever + + + align:start position:0% +I'm not saying all of them have ever +been synthesized since the formation of + + align:start position:0% +been synthesized since the formation of + + + align:start position:0% +been synthesized since the formation of +Life on this planet indeed uh since some + + align:start position:0% +Life on this planet indeed uh since some + + + align:start position:0% +Life on this planet indeed uh since some +amino acid chains are 4 5 600 even 2 000 + + align:start position:0% +amino acid chains are 4 5 600 even 2 000 + + + align:start position:0% +amino acid chains are 4 5 600 even 2 000 +amino acid uh residues long I think the + + align:start position:0% +amino acid uh residues long I think the + + + align:start position:0% +amino acid uh residues long I think the +one that is affected in muscular + + align:start position:0% +one that is affected in muscular + + + align:start position:0% +one that is affected in muscular +dystrophy is more than 2 000 amino acids + + align:start position:0% +dystrophy is more than 2 000 amino acids + + + align:start position:0% +dystrophy is more than 2 000 amino acids +dystrophin does anybody know here it's + + align:start position:0% +dystrophin does anybody know here it's + + + align:start position:0% +dystrophin does anybody know here it's +big anyhow imagine the number of + + align:start position:0% +big anyhow imagine the number of + + + align:start position:0% +big anyhow imagine the number of +possibilities so combinatorially life + + align:start position:0% +possibilities so combinatorially life + + + align:start position:0% +possibilities so combinatorially life +can make almost whatever types of amino + + align:start position:0% +can make almost whatever types of amino + + + align:start position:0% +can make almost whatever types of amino +acids it would like by dictating the + + align:start position:0% +acids it would like by dictating the + + + align:start position:0% +acids it would like by dictating the +sequence of amino acids now + + align:start position:0% +sequence of amino acids now + + + align:start position:0% +sequence of amino acids now +let's just go and look here again + + align:start position:0% +let's just go and look here again + + + align:start position:0% +let's just go and look here again +there's a secondary structure the + + align:start position:0% +there's a secondary structure the + + + align:start position:0% +there's a secondary structure the +tertiary structure is the way in which + + align:start position:0% +tertiary structure is the way in which + + + align:start position:0% +tertiary structure is the way in which +the different Alpha helices here or beta + + align:start position:0% +the different Alpha helices here or beta + + + align:start position:0% +the different Alpha helices here or beta +pleated sheets are disposed + + align:start position:0% +pleated sheets are disposed + + + align:start position:0% +pleated sheets are disposed +three-dimensionally with respect to one + + align:start position:0% +three-dimensionally with respect to one + + + align:start position:0% +three-dimensionally with respect to one +another + + align:start position:0% +another + + + align:start position:0% +another +and the quaternary structure + + align:start position:0% +and the quaternary structure + + + align:start position:0% +and the quaternary structure +represents how different single + + align:start position:0% +represents how different single + + + align:start position:0% +represents how different single +polypeptides are associated one with the + + align:start position:0% +polypeptides are associated one with the + + + align:start position:0% +polypeptides are associated one with the +other so for example hemoglobin is a + + align:start position:0% +other so for example hemoglobin is a + + + align:start position:0% +other so for example hemoglobin is a +tetramer + + align:start position:0% +tetramer + + + align:start position:0% +tetramer +hemoglobin doesn't exist as a monomeric + + align:start position:0% +hemoglobin doesn't exist as a monomeric + + + align:start position:0% +hemoglobin doesn't exist as a monomeric +protein in solution exists as a tetramer + + align:start position:0% +protein in solution exists as a tetramer + + + align:start position:0% +protein in solution exists as a tetramer +and there's two kinds of globin chains + + align:start position:0% +and there's two kinds of globin chains + + + align:start position:0% +and there's two kinds of globin chains +there's an alpha alpha kind and a beta + + align:start position:0% +there's an alpha alpha kind and a beta + + + align:start position:0% +there's an alpha alpha kind and a beta +kind and if we look in a very rough and + + align:start position:0% +kind and if we look in a very rough and + + + align:start position:0% +kind and if we look in a very rough and +schematic way at the way that a + + align:start position:0% +schematic way at the way that a + + + align:start position:0% +schematic way at the way that a +hemoglobin tetramer is arranged there + + align:start position:0% +hemoglobin tetramer is arranged there + + + align:start position:0% +hemoglobin tetramer is arranged there +are two alpha polypeptide chains and two + + align:start position:0% +are two alpha polypeptide chains and two + + + align:start position:0% +are two alpha polypeptide chains and two +beta polypeptide chains they're not + + align:start position:0% +beta polypeptide chains they're not + + + align:start position:0% +beta polypeptide chains they're not +covalently attached to one another + + align:start position:0% +covalently attached to one another + + + align:start position:0% +covalently attached to one another +they're associated with one another via + + align:start position:0% +they're associated with one another via + + + align:start position:0% +they're associated with one another via +hydrogen bonds and hydrophobic + + align:start position:0% +hydrogen bonds and hydrophobic + + + align:start position:0% +hydrogen bonds and hydrophobic +interactions and this is the actual + + align:start position:0% +interactions and this is the actual + + + align:start position:0% +interactions and this is the actual +native configuration of globin to Alpha + + align:start position:0% +native configuration of globin to Alpha + + + align:start position:0% +native configuration of globin to Alpha +and two beta chains it doesn't exist as + + align:start position:0% +and two beta chains it doesn't exist as + + + align:start position:0% +and two beta chains it doesn't exist as +a single amino acid in solution it + + align:start position:0% +a single amino acid in solution it + + + align:start position:0% +a single amino acid in solution it +exists as a tetramer and indeed most or + + align:start position:0% +exists as a tetramer and indeed most or + + + align:start position:0% +exists as a tetramer and indeed most or +I shouldn't say most but very many + + align:start position:0% +I shouldn't say most but very many + + + align:start position:0% +I shouldn't say most but very many +proteins exist in these um + + align:start position:0% +proteins exist in these um + + + align:start position:0% +proteins exist in these um +configurations where the where the + + align:start position:0% +configurations where the where the + + + align:start position:0% +configurations where the where the +tertiary structure represents uh four + + align:start position:0% +tertiary structure represents uh four + + + align:start position:0% +tertiary structure represents uh four +different amino acid chains + + align:start position:0% +different amino acid chains + + + align:start position:0% +different amino acid chains +so these are each of these has an n and + + align:start position:0% +so these are each of these has an n and + + + align:start position:0% +so these are each of these has an n and +C terminal each of these is chemically + + align:start position:0% +C terminal each of these is chemically + + + align:start position:0% +C terminal each of these is chemically +distinct these four could probably be + + align:start position:0% +distinct these four could probably be + + + align:start position:0% +distinct these four could probably be +taken apart from one another simply by + + align:start position:0% +taken apart from one another simply by + + + align:start position:0% +taken apart from one another simply by +raising the temperature and they + + align:start position:0% +raising the temperature and they + + + align:start position:0% +raising the temperature and they +associate like this and in in the + + align:start position:0% +associate like this and in in the + + + align:start position:0% +associate like this and in in the +absence of this Association if you just + + align:start position:0% +absence of this Association if you just + + + align:start position:0% +absence of this Association if you just +had one of these Alphas or one of these + + align:start position:0% +had one of these Alphas or one of these + + + align:start position:0% +had one of these Alphas or one of these +betas it wouldn't function well at all + + align:start position:0% +betas it wouldn't function well at all + + + align:start position:0% +betas it wouldn't function well at all +in fact it might be totally + + align:start position:0% +in fact it might be totally + + + align:start position:0% +in fact it might be totally +dysfunctional + + align:start position:0% +dysfunctional + + + align:start position:0% +dysfunctional +one other thing that may be implicit to + + align:start position:0% +one other thing that may be implicit to + + + align:start position:0% +one other thing that may be implicit to +you but I haven't said but that is very + + align:start position:0% +you but I haven't said but that is very + + + align:start position:0% +you but I haven't said but that is very +important to realize is the following + + align:start position:0% +important to realize is the following + + + align:start position:0% +important to realize is the following +let's imagine that this is the + + align:start position:0% +let's imagine that this is the + + + align:start position:0% +let's imagine that this is the +three-dimensional structure of a protein + + align:start position:0% +three-dimensional structure of a protein + + + align:start position:0% +three-dimensional structure of a protein +as it may well be + + align:start position:0% +as it may well be + + + align:start position:0% +as it may well be +let's now think about hydrophobic and + + align:start position:0% +let's now think about hydrophobic and + + + align:start position:0% +let's now think about hydrophobic and +hydrophilic amino acids + + align:start position:0% +hydrophilic amino acids + + + align:start position:0% +hydrophilic amino acids +the hydrophobic amino acids hate to be + + align:start position:0% +the hydrophobic amino acids hate to be + + + align:start position:0% +the hydrophobic amino acids hate to be +present in water and therefore they are + + align:start position:0% +present in water and therefore they are + + + align:start position:0% +present in water and therefore they are +we can imagine in this case correctly + + align:start position:0% +we can imagine in this case correctly + + + align:start position:0% +we can imagine in this case correctly +tucked away inside the interstices of + + align:start position:0% +tucked away inside the interstices of + + + align:start position:0% +tucked away inside the interstices of +the protein far away from the surface + + align:start position:0% +the protein far away from the surface + + + align:start position:0% +the protein far away from the surface +they don't have any contact with water + + align:start position:0% +they don't have any contact with water + + + align:start position:0% +they don't have any contact with water +conversely the highly charged + + align:start position:0% +conversely the highly charged + + + align:start position:0% +conversely the highly charged +hydrophilic amino acids are actually + + align:start position:0% +hydrophilic amino acids are actually + + + align:start position:0% +hydrophilic amino acids are actually +sticking out at the surface + + align:start position:0% +sticking out at the surface + + + align:start position:0% +sticking out at the surface +and this begins to yield yet another + + align:start position:0% +and this begins to yield yet another + + + align:start position:0% +and this begins to yield yet another +insight into how the three-dimensional + + align:start position:0% +insight into how the three-dimensional + + + align:start position:0% +insight into how the three-dimensional +stereochemistry of proteins is + + align:start position:0% +stereochemistry of proteins is + + + align:start position:0% +stereochemistry of proteins is +maintained and dictated + + align:start position:0% +maintained and dictated + + + align:start position:0% +maintained and dictated +because the hydrophobic amino acids + + align:start position:0% +because the hydrophobic amino acids + + + align:start position:0% +because the hydrophobic amino acids +through hydrophobic interactions + + align:start position:0% +through hydrophobic interactions + + + align:start position:0% +through hydrophobic interactions +stabilize the inner core of the protein + + align:start position:0% +stabilize the inner core of the protein + + + align:start position:0% +stabilize the inner core of the protein +that is that is well shielded from the + + align:start position:0% +that is that is well shielded from the + + + align:start position:0% +that is that is well shielded from the +aqueous solvent the hydrophilic amino + + align:start position:0% +aqueous solvent the hydrophilic amino + + + align:start position:0% +aqueous solvent the hydrophilic amino +acids are on the outside they like to be + + align:start position:0% +acids are on the outside they like to be + + + align:start position:0% +acids are on the outside they like to be +in Intimate contact with the water + + align:start position:0% +in Intimate contact with the water + + + align:start position:0% +in Intimate contact with the water +so we can we already now have talked + + align:start position:0% +so we can we already now have talked + + + align:start position:0% +so we can we already now have talked +about a number of distinct different uh + + align:start position:0% +about a number of distinct different uh + + + align:start position:0% +about a number of distinct different uh +interactions that are responsible for + + align:start position:0% +interactions that are responsible for + + + align:start position:0% +interactions that are responsible for +creating the three-dimensional + + align:start position:0% +creating the three-dimensional + + + align:start position:0% +creating the three-dimensional +stereochemistry of the protein + + align:start position:0% +stereochemistry of the protein + + + align:start position:0% +stereochemistry of the protein +first of all there are the um the + + align:start position:0% +first of all there are the um the + + + align:start position:0% +first of all there are the um the +disulfide bonds which create chain to + + align:start position:0% +disulfide bonds which create chain to + + + align:start position:0% +disulfide bonds which create chain to +chain uh covalent interactions there are + + align:start position:0% +chain uh covalent interactions there are + + + align:start position:0% +chain uh covalent interactions there are +the hydrogen bonds which in which + + align:start position:0% +the hydrogen bonds which in which + + + align:start position:0% +the hydrogen bonds which in which +different side chains can uh different + + align:start position:0% +different side chains can uh different + + + align:start position:0% +different side chains can uh different +uh chains can interact with one another + + align:start position:0% +uh chains can interact with one another + + + align:start position:0% +uh chains can interact with one another +and there are these hydrophobic and + + align:start position:0% +and there are these hydrophobic and + + + align:start position:0% +and there are these hydrophobic and +hydrophilic interactions + + align:start position:0% +hydrophilic interactions + + + align:start position:0% +hydrophilic interactions +and there are some relatively + + align:start position:0% +and there are some relatively + + + align:start position:0% +and there are some relatively +inconsequential Van Der waals + + align:start position:0% +inconsequential Van Der waals + + + align:start position:0% +inconsequential Van Der waals +interactions which are really not worth + + align:start position:0% +interactions which are really not worth + + + align:start position:0% +interactions which are really not worth +discussing although some people get + + align:start position:0% +discussing although some people get + + + align:start position:0% +discussing although some people get +really excited about them but we won't + + align:start position:0% +really excited about them but we won't + + + align:start position:0% +really excited about them but we won't +so here we now begin to see that we have + + align:start position:0% +so here we now begin to see that we have + + + align:start position:0% +so here we now begin to see that we have +really interesting polypeptides unlike + + align:start position:0% +really interesting polypeptides unlike + + + align:start position:0% +really interesting polypeptides unlike +the boring polypeptides that are + + align:start position:0% +the boring polypeptides that are + + + align:start position:0% +the boring polypeptides that are +ultimately + + align:start position:0% +ultimately + + + align:start position:0% +ultimately +um uh is the way one must judge + + align:start position:0% +um uh is the way one must judge + + + align:start position:0% +um uh is the way one must judge +um + + align:start position:0% +um + + + align:start position:0% +um +carbohydrates some people think + + align:start position:0% +carbohydrates some people think + + + align:start position:0% +carbohydrates some people think +carbohydrate chemistry is really + + align:start position:0% +carbohydrate chemistry is really + + + align:start position:0% +carbohydrate chemistry is really +interesting but entrepreneur it really + + align:start position:0% +interesting but entrepreneur it really + + + align:start position:0% +interesting but entrepreneur it really +isn't that interesting because you just + + align:start position:0% +isn't that interesting because you just + + + align:start position:0% +isn't that interesting because you just +have the same monomer + + align:start position:0% +have the same monomer + + + align:start position:0% +have the same monomer +in a 100 or 500 scratches here a protein + + align:start position:0% +in a 100 or 500 scratches here a protein + + + align:start position:0% +in a 100 or 500 scratches here a protein +is much more interesting because this of + + align:start position:0% +is much more interesting because this of + + + align:start position:0% +is much more interesting because this of +this enormous variability in amino acid + + align:start position:0% +this enormous variability in amino acid + + + align:start position:0% +this enormous variability in amino acid +sequence + + align:start position:0% + + + + align:start position:0% + +kinds of + + align:start position:0% +kinds of + + + align:start position:0% +kinds of +chemical reactivity + + align:start position:0% +chemical reactivity + + + align:start position:0% +chemical reactivity +features + + align:start position:0% +features + + + align:start position:0% +features +because of these these 20 different + + align:start position:0% +because of these these 20 different + + + align:start position:0% +because of these these 20 different +amino acids + + align:start position:0% +amino acids + + + align:start position:0% +amino acids +if you were to imagine life on another + + align:start position:0% +if you were to imagine life on another + + + align:start position:0% +if you were to imagine life on another +planet and we imagine that there were + + align:start position:0% +planet and we imagine that there were + + + align:start position:0% +planet and we imagine that there were +let's say amino acid likes uh molecules + + align:start position:0% +let's say amino acid likes uh molecules + + + align:start position:0% +let's say amino acid likes uh molecules +that were part of life + + align:start position:0% +that were part of life + + + align:start position:0% +that were part of life +maybe that other life wouldn't have + + align:start position:0% +maybe that other life wouldn't have + + + align:start position:0% +maybe that other life wouldn't have +exactly the same 20 amino acids as we do + + align:start position:0% +exactly the same 20 amino acids as we do + + + align:start position:0% +exactly the same 20 amino acids as we do +it almost certainly would be a + + align:start position:0% +it almost certainly would be a + + + align:start position:0% +it almost certainly would be a +water-based the way we are + + align:start position:0% +water-based the way we are + + + align:start position:0% +water-based the way we are +um but it would also rely on on hydrogen + + align:start position:0% +um but it would also rely on on hydrogen + + + align:start position:0% +um but it would also rely on on hydrogen +bonds and and and + + align:start position:0% +bonds and and and + + + align:start position:0% +bonds and and and +um hydrophilicity and hydrophobicity + + align:start position:0% +um hydrophilicity and hydrophobicity + + + align:start position:0% +um hydrophilicity and hydrophobicity +interactions uh in order to dictate the + + align:start position:0% +interactions uh in order to dictate the + + + align:start position:0% +interactions uh in order to dictate the +three-dimensional structure + + align:start position:0% +three-dimensional structure + + + align:start position:0% +three-dimensional structure +in the absence of this very specific + + align:start position:0% +in the absence of this very specific + + + align:start position:0% +in the absence of this very specific +three-dimensional structure I will tell + + align:start position:0% +three-dimensional structure I will tell + + + align:start position:0% +three-dimensional structure I will tell +you that this enzyme could not function + + align:start position:0% +you that this enzyme could not function + + + align:start position:0% +you that this enzyme could not function +and if you were to take this enzyme if + + align:start position:0% +and if you were to take this enzyme if + + + align:start position:0% +and if you were to take this enzyme if +it were a typical enzyme and you were to + + align:start position:0% +it were a typical enzyme and you were to + + + align:start position:0% +it were a typical enzyme and you were to +heat it up briefly uh even often + + align:start position:0% +heat it up briefly uh even often + + + align:start position:0% +heat it up briefly uh even often +slightly above normal body temperature + + align:start position:0% +slightly above normal body temperature + + + align:start position:0% +slightly above normal body temperature +it might denature I.E it might lose its + + align:start position:0% +it might denature I.E it might lose its + + + align:start position:0% +it might denature I.E it might lose its +its three-dimensional + + align:start position:0% +its three-dimensional + + + align:start position:0% +its three-dimensional +um structure irreversibly and once it + + align:start position:0% +um structure irreversibly and once it + + + align:start position:0% +um structure irreversibly and once it +were denatured once it was denatured + + align:start position:0% +were denatured once it was denatured + + + align:start position:0% +were denatured once it was denatured +this process of denaturation it might + + align:start position:0% +this process of denaturation it might + + + align:start position:0% +this process of denaturation it might +not be able to spontaneously reassume + + align:start position:0% +not be able to spontaneously reassume + + + align:start position:0% +not be able to spontaneously reassume +that pre-existing three-dimensional + + align:start position:0% +that pre-existing three-dimensional + + + align:start position:0% +that pre-existing three-dimensional +configuration and therefore would + + align:start position:0% +configuration and therefore would + + + align:start position:0% +configuration and therefore would +forever be inactive + + align:start position:0% +forever be inactive + + + align:start position:0% +forever be inactive +that means to say very explicitly that + + align:start position:0% +that means to say very explicitly that + + + align:start position:0% +that means to say very explicitly that +even though the amino acids that are + + align:start position:0% +even though the amino acids that are + + + align:start position:0% +even though the amino acids that are +creating that active catalytic site + + align:start position:0% +creating that active catalytic site + + + align:start position:0% +creating that active catalytic site +remain there + + align:start position:0% +remain there + + + align:start position:0% +remain there +they're highly specific + + align:start position:0% +they're highly specific + + + align:start position:0% +they're highly specific +three-dimensional uh disposition is + + align:start position:0% +three-dimensional uh disposition is + + + align:start position:0% +three-dimensional uh disposition is +critical for the continued actions of + + align:start position:0% +critical for the continued actions of + + + align:start position:0% +critical for the continued actions of +this enzyme and once they're + + align:start position:0% +this enzyme and once they're + + + align:start position:0% +this enzyme and once they're +three-dimensional + + align:start position:0% +three-dimensional + + + align:start position:0% +three-dimensional +dispositions are shifted around through + + align:start position:0% +dispositions are shifted around through + + + align:start position:0% +dispositions are shifted around through +the process of interactions then uh we + + align:start position:0% +the process of interactions then uh we + + + align:start position:0% +the process of interactions then uh we +have a trouble because the enzyme can no + + align:start position:0% +have a trouble because the enzyme can no + + + align:start position:0% +have a trouble because the enzyme can no +longer do its assigned task + + align:start position:0% +longer do its assigned task + + + align:start position:0% +longer do its assigned task +we're going to go now to uh an even + + align:start position:0% +we're going to go now to uh an even + + + align:start position:0% +we're going to go now to uh an even +higher order of complexity in one sense + + align:start position:0% +higher order of complexity in one sense + + + align:start position:0% +higher order of complexity in one sense +we're going to you go to the the royalty + + align:start position:0% +we're going to you go to the the royalty + + + align:start position:0% +we're going to you go to the the royalty +of the macromolecules which are the + + align:start position:0% +of the macromolecules which are the + + + align:start position:0% +of the macromolecules which are the +nucleic acids of course protein chemists + + align:start position:0% +nucleic acids of course protein chemists + + + align:start position:0% +nucleic acids of course protein chemists +would take great umbrage at the very + + align:start position:0% +would take great umbrage at the very + + + align:start position:0% +would take great umbrage at the very +notion that uh there are things better + + align:start position:0% +notion that uh there are things better + + + align:start position:0% +notion that uh there are things better +than proteins but the fact of the matter + + align:start position:0% +than proteins but the fact of the matter + + + align:start position:0% +than proteins but the fact of the matter +is entrepreneur uh there are I can't + + align:start position:0% +is entrepreneur uh there are I can't + + + align:start position:0% +is entrepreneur uh there are I can't +show you that overhead because it's from + + align:start position:0% +show you that overhead because it's from + + + align:start position:0% +show you that overhead because it's from +the other textbook + + align:start position:0% +the other textbook + + + align:start position:0% +the other textbook +which is copyright and we're being + + align:start position:0% +which is copyright and we're being + + + align:start position:0% +which is copyright and we're being +filmed + + align:start position:0% +filmed + + + align:start position:0% +filmed +how many people have had the backs of + + align:start position:0% +how many people have had the backs of + + + align:start position:0% +how many people have had the backs of +their heads immortalized on these videos + + align:start position:0% +their heads immortalized on these videos + + + align:start position:0% +their heads immortalized on these videos +did you call home and ask anybody to + + align:start position:0% +did you call home and ask anybody to + + + align:start position:0% +did you call home and ask anybody to +identify you + + align:start position:0% +identify you + + + align:start position:0% +identify you +I don't know but soon you'll be uh + + align:start position:0% +I don't know but soon you'll be uh + + + align:start position:0% +I don't know but soon you'll be uh +you'll have your 50 each of us is in has + + align:start position:0% +you'll have your 50 each of us is in has + + + align:start position:0% +you'll have your 50 each of us is in has +the Limelight for 15 minutes in a + + align:start position:0% +the Limelight for 15 minutes in a + + + align:start position:0% +the Limelight for 15 minutes in a +Lifetime right so you'll have your 15 + + align:start position:0% +Lifetime right so you'll have your 15 + + + align:start position:0% +Lifetime right so you'll have your 15 +minutes okay here are here are some + + align:start position:0% +minutes okay here are here are some + + + align:start position:0% +minutes okay here are here are some +nucleic acids and let's look at these + + align:start position:0% +nucleic acids and let's look at these + + + align:start position:0% +nucleic acids and let's look at these +nucleic acids and the way they're put + + align:start position:0% +nucleic acids and the way they're put + + + align:start position:0% +nucleic acids and the way they're put +together + + align:start position:0% +together + + + align:start position:0% +together +keep in mind to anticipate what we're + + align:start position:0% +keep in mind to anticipate what we're + + + align:start position:0% +keep in mind to anticipate what we're +going to say next time once again we + + align:start position:0% +going to say next time once again we + + + align:start position:0% +going to say next time once again we +want to make end-to-end Aggregates we + + align:start position:0% +want to make end-to-end Aggregates we + + + align:start position:0% +want to make end-to-end Aggregates we +want to polymerize molecules + + align:start position:0% +want to polymerize molecules + + + align:start position:0% +want to polymerize molecules +um and in this case we want to do so + + align:start position:0% +um and in this case we want to do so + + + align:start position:0% +um and in this case we want to do so +once again through a dehydration + + align:start position:0% +once again through a dehydration + + + align:start position:0% +once again through a dehydration +reaction + + align:start position:0% +reaction + + + align:start position:0% +reaction +and moreover just to look at the + + align:start position:0% +and moreover just to look at the + + + align:start position:0% +and moreover just to look at the +building blocks of nucleic acids we + + align:start position:0% +building blocks of nucleic acids we + + + align:start position:0% +building blocks of nucleic acids we +start again in this case with two + + align:start position:0% +start again in this case with two + + + align:start position:0% +start again in this case with two +pentoses recall that they have four + + align:start position:0% +pentoses recall that they have four + + + align:start position:0% +pentoses recall that they have four +carbons one two three four no did I say + + align:start position:0% +carbons one two three four no did I say + + + align:start position:0% +carbons one two three four no did I say +four you know I meant five + + align:start position:0% +four you know I meant five + + + align:start position:0% +four you know I meant five +one two three four five so whenever I + + align:start position:0% +one two three four five so whenever I + + + align:start position:0% +one two three four five so whenever I +say four from now on I mean + + align:start position:0% + + + + align:start position:0% + +or whenever I say four I may also mean + + align:start position:0% +or whenever I say four I may also mean + + + align:start position:0% +or whenever I say four I may also mean +four okay one two three four five + + align:start position:0% +four okay one two three four five + + + align:start position:0% +four okay one two three four five +um and and let's look at the Two basic + + align:start position:0% +um and and let's look at the Two basic + + + align:start position:0% +um and and let's look at the Two basic +kinds of pentose molecules that are uh + + align:start position:0% +kinds of pentose molecules that are uh + + + align:start position:0% +kinds of pentose molecules that are uh +present in nucleic acid because they + + align:start position:0% +present in nucleic acid because they + + + align:start position:0% +present in nucleic acid because they +Define the essential difference between + + align:start position:0% +Define the essential difference between + + + align:start position:0% +Define the essential difference between +DNA and RNA + + align:start position:0% +DNA and RNA + + + align:start position:0% +DNA and RNA +here's a regular old rather familiar + + align:start position:0% +here's a regular old rather familiar + + + align:start position:0% +here's a regular old rather familiar +kind of pentose with five carbons + + align:start position:0% +kind of pentose with five carbons + + + align:start position:0% +kind of pentose with five carbons +and here's an unfamiliar kind of pentose + + align:start position:0% +and here's an unfamiliar kind of pentose + + + align:start position:0% +and here's an unfamiliar kind of pentose +which we call deoxyribose why because if + + align:start position:0% +which we call deoxyribose why because if + + + align:start position:0% +which we call deoxyribose why because if +you look really carefully you see that + + align:start position:0% +you look really carefully you see that + + + align:start position:0% +you look really carefully you see that +the hydroxyl group here which should be + + align:start position:0% +the hydroxyl group here which should be + + + align:start position:0% +the hydroxyl group here which should be +present in any self-respecting pentose + + align:start position:0% +present in any self-respecting pentose + + + align:start position:0% +present in any self-respecting pentose +is missing and is replaced simply by a + + align:start position:0% +is missing and is replaced simply by a + + + align:start position:0% +is missing and is replaced simply by a +hydrogen group I.E it's lost it's oxygen + + align:start position:0% +hydrogen group I.E it's lost it's oxygen + + + align:start position:0% +hydrogen group I.E it's lost it's oxygen +whence come with the word + + align:start position:0% +whence come with the word + + + align:start position:0% +whence come with the word +deoxyribose and ultimately clearly the + + align:start position:0% +deoxyribose and ultimately clearly the + + + align:start position:0% +deoxyribose and ultimately clearly the +word deoxyribose nucleic acid + + align:start position:0% +word deoxyribose nucleic acid + + + align:start position:0% +word deoxyribose nucleic acid +and one of the attributes one of the + + align:start position:0% +and one of the attributes one of the + + + align:start position:0% +and one of the attributes one of the +virtues of carbohydrates as we discussed + + align:start position:0% +virtues of carbohydrates as we discussed + + + align:start position:0% +virtues of carbohydrates as we discussed +last time were these numerous hydroxyl + + align:start position:0% +last time were these numerous hydroxyl + + + align:start position:0% +last time were these numerous hydroxyl +groups which represent opportunities for + + align:start position:0% +groups which represent opportunities for + + + align:start position:0% +groups which represent opportunities for +all kinds of dehydration reactions which + + align:start position:0% +all kinds of dehydration reactions which + + + align:start position:0% +all kinds of dehydration reactions which +can enable one to build much more + + align:start position:0% +can enable one to build much more + + + align:start position:0% +can enable one to build much more +complex molecules and here we see uh the + + align:start position:0% +complex molecules and here we see uh the + + + align:start position:0% +complex molecules and here we see uh the +structure of for example a + + align:start position:0% +structure of for example a + + + align:start position:0% +structure of for example a +deoxyribonucleotide whose detailed + + align:start position:0% +deoxyribonucleotide whose detailed + + + align:start position:0% +deoxyribonucleotide whose detailed +structure will will get into next time + + align:start position:0% +structure will will get into next time + + + align:start position:0% +structure will will get into next time +but just let's look at how these + + align:start position:0% +but just let's look at how these + + + align:start position:0% +but just let's look at how these +hydroxyl groups have been used the + + align:start position:0% +hydroxyl groups have been used the + + + align:start position:0% +hydroxyl groups have been used the +hydroxyl group in this case in DNA and + + align:start position:0% +hydroxyl group in this case in DNA and + + + align:start position:0% +hydroxyl group in this case in DNA and +by the way it notice notice that the + + align:start position:0% +by the way it notice notice that the + + + align:start position:0% +by the way it notice notice that the +structure I've shown here + + align:start position:0% +structure I've shown here + + + align:start position:0% +structure I've shown here +there's a side chain attached here and a + + align:start position:0% +there's a side chain attached here and a + + + align:start position:0% +there's a side chain attached here and a +side chain attached here and neither of + + align:start position:0% +side chain attached here and neither of + + + align:start position:0% +side chain attached here and neither of +those depends on whether or not there's + + align:start position:0% +those depends on whether or not there's + + + align:start position:0% +those depends on whether or not there's +a hydrogen or a hydroxyl right here + + align:start position:0% +a hydrogen or a hydroxyl right here + + + align:start position:0% +a hydrogen or a hydroxyl right here +and look what what's happened here here + + align:start position:0% +and look what what's happened here here + + + align:start position:0% +and look what what's happened here here +we have this hydroxyl + + align:start position:0% +we have this hydroxyl + + + align:start position:0% +we have this hydroxyl +over here to which a base has been + + align:start position:0% +over here to which a base has been + + + align:start position:0% +over here to which a base has been +attached covalently once again by a + + align:start position:0% +attached covalently once again by a + + + align:start position:0% +attached covalently once again by a +dehydration reaction and here we have a + + align:start position:0% +dehydration reaction and here we have a + + + align:start position:0% +dehydration reaction and here we have a +situation where actually three phosphate + + align:start position:0% +situation where actually three phosphate + + + align:start position:0% +situation where actually three phosphate +groups have been attached to the + + align:start position:0% +groups have been attached to the + + + align:start position:0% +groups have been attached to the +hydroxyl group in this direction + + align:start position:0% +hydroxyl group in this direction + + + align:start position:0% +hydroxyl group in this direction +and this represents the basic building + + align:start position:0% +and this represents the basic building + + + align:start position:0% +and this represents the basic building +blocks of nucleic acids now one of the + + align:start position:0% +blocks of nucleic acids now one of the + + + align:start position:0% +blocks of nucleic acids now one of the +things that's going to be really + + align:start position:0% +things that's going to be really + + + align:start position:0% +things that's going to be really +important and that you're going to have + + align:start position:0% +important and that you're going to have + + + align:start position:0% +important and that you're going to have +to memorize I told you you weren't going + + align:start position:0% +to memorize I told you you weren't going + + + align:start position:0% +to memorize I told you you weren't going +to have to memorize anything + + align:start position:0% +to have to memorize anything + + + align:start position:0% +to have to memorize anything +but you didn't believe me did you + + align:start position:0% +but you didn't believe me did you + + + align:start position:0% +but you didn't believe me did you +good okay one of the things you're gonna + + align:start position:0% +good okay one of the things you're gonna + + + align:start position:0% +good okay one of the things you're gonna +have to memorize is the numbering system + + align:start position:0% +have to memorize is the numbering system + + + align:start position:0% +have to memorize is the numbering system +here this is number one two three four + + align:start position:0% +here this is number one two three four + + + align:start position:0% +here this is number one two three four +five or to be totally Frank and you know + + align:start position:0% +five or to be totally Frank and you know + + + align:start position:0% +five or to be totally Frank and you know +I'm always that one prime two prime + + align:start position:0% +I'm always that one prime two prime + + + align:start position:0% +I'm always that one prime two prime +three prime four Prime five Prime + + align:start position:0% +three prime four Prime five Prime + + + align:start position:0% +three prime four Prime five Prime +and that numbering system it turns out + + align:start position:0% +and that numbering system it turns out + + + align:start position:0% +and that numbering system it turns out +is going to be very important for our + + align:start position:0% +is going to be very important for our + + + align:start position:0% +is going to be very important for our +subsequent discussions + + align:start position:0% +subsequent discussions + + + align:start position:0% +subsequent discussions +notice here that for example it's it's + + align:start position:0% +notice here that for example it's it's + + + align:start position:0% +notice here that for example it's it's +here at the two prime position that this + + align:start position:0% +here at the two prime position that this + + + align:start position:0% +here at the two prime position that this +deoxyribose is lacking the the oxygen + + align:start position:0% +deoxyribose is lacking the the oxygen + + + align:start position:0% +deoxyribose is lacking the the oxygen +that is present normally in um + + align:start position:0% +that is present normally in um + + + align:start position:0% +that is present normally in um +in in in RNA and with all this in mind + + align:start position:0% +in in in RNA and with all this in mind + + + align:start position:0% +in in in RNA and with all this in mind +we will wait in great suspense until + + align:start position:0% +we will wait in great suspense until + + + align:start position:0% +we will wait in great suspense until +Wednesday when we actually talk about + + align:start position:0% +Wednesday when we actually talk about + + + align:start position:0% +Wednesday when we actually talk about +how this is exploited to make highly uh + + align:start position:0% +how this is exploited to make highly uh + + + align:start position:0% +how this is exploited to make highly uh +complex polymers have a good two days + + align:start position:0% +complex polymers have a good two days + + + align:start position:0% +complex polymers have a good two days +see you Wednesday at 10. + + align:start position:0% + + + + align:start position:0% + +[Applause] \ No newline at end of file diff --git a/cQtCpJyl77o.txt b/cQtCpJyl77o.txt new file mode 100644 index 0000000000000000000000000000000000000000..4973022fe65b80e0439ca37554de16c11f924972 --- /dev/null +++ b/cQtCpJyl77o.txt @@ -0,0 +1,523 @@ +align:start position:0% + +all right so let us revisit the example + + align:start position:0% +all right so let us revisit the example + + + align:start position:0% +all right so let us revisit the example +from last lecture so we have a Markov + + align:start position:0% +from last lecture so we have a Markov + + + align:start position:0% +from last lecture so we have a Markov +chain with two states 1 & 2 and this + + align:start position:0% +chain with two states 1 & 2 and this + + + align:start position:0% +chain with two states 1 & 2 and this +Markov chain as a single recurrent class + + align:start position:0% +Markov chain as a single recurrent class + + + align:start position:0% +Markov chain as a single recurrent class +right and then also it's not very thick + + align:start position:0% +right and then also it's not very thick + + + align:start position:0% +right and then also it's not very thick +right because we have Sal transition of + + align:start position:0% +right because we have Sal transition of + + + align:start position:0% +right because we have Sal transition of +this type so as a result this is well + + align:start position:0% +this type so as a result this is well + + + align:start position:0% +this type so as a result this is well +defined and this steady state + + align:start position:0% +defined and this steady state + + + align:start position:0% +defined and this steady state +probabilities from 1 to M in that case + + align:start position:0% +probabilities from 1 to M in that case + + + align:start position:0% +probabilities from 1 to M in that case +for us M equals 2 right so let us write + + align:start position:0% +for us M equals 2 right so let us write + + + align:start position:0% +for us M equals 2 right so let us write +this system and solve the system of + + align:start position:0% +this system and solve the system of + + + align:start position:0% +this system and solve the system of +linear equation for this example here so + + align:start position:0% +linear equation for this example here so + + + align:start position:0% +linear equation for this example here so +what we have is PI 1 equals PI 1 times + + align:start position:0% +what we have is PI 1 equals PI 1 times + + + align:start position:0% +what we have is PI 1 equals PI 1 times +0.5 plus PI 2 times 0.2 so that's the + + align:start position:0% +0.5 plus PI 2 times 0.2 so that's the + + + align:start position:0% +0.5 plus PI 2 times 0.2 so that's the +first equation the correspond to J + + align:start position:0% +first equation the correspond to J + + + align:start position:0% +first equation the correspond to J +equals 1 now for J equals 2 pi 2 equals + + align:start position:0% +equals 1 now for J equals 2 pi 2 equals + + + align:start position:0% +equals 1 now for J equals 2 pi 2 equals +PI 1 times 0.5 plus pi 2 times 0.8 so we + + align:start position:0% +PI 1 times 0.5 plus pi 2 times 0.8 so we + + + align:start position:0% +PI 1 times 0.5 plus pi 2 times 0.8 so we +have a system of two equations with two + + align:start position:0% +have a system of two equations with two + + + align:start position:0% +have a system of two equations with two +unknowns PI 1 and PI 2 let's rewrite + + align:start position:0% +unknowns PI 1 and PI 2 let's rewrite + + + align:start position:0% +unknowns PI 1 and PI 2 let's rewrite +them can I pass this one on this side + + align:start position:0% +them can I pass this one on this side + + + align:start position:0% +them can I pass this one on this side +and this one on this side so we get PI 1 + + align:start position:0% +and this one on this side so we get PI 1 + + + align:start position:0% +and this one on this side so we get PI 1 +times 1 minus 0.5 0.5 equals pi 2 times + + align:start position:0% +times 1 minus 0.5 0.5 equals pi 2 times + + + align:start position:0% +times 1 minus 0.5 0.5 equals pi 2 times +0.2 and this 1 PI 2 times 1 minus 0.8 is + + align:start position:0% +0.2 and this 1 PI 2 times 1 minus 0.8 is + + + align:start position:0% +0.2 and this 1 PI 2 times 1 minus 0.8 is +zero point 2 equals PI 1 times 0.5 I we + + align:start position:0% +zero point 2 equals PI 1 times 0.5 I we + + + align:start position:0% +zero point 2 equals PI 1 times 0.5 I we +realize that these two happen to be the + + align:start position:0% +realize that these two happen to be the + + + align:start position:0% +realize that these two happen to be the +same + + align:start position:0% +same + + + align:start position:0% +same +so they are not enough to define a + + align:start position:0% +so they are not enough to define a + + + align:start position:0% +so they are not enough to define a +unique solution so we have to add + + align:start position:0% +unique solution so we have to add + + + align:start position:0% +unique solution so we have to add +another equations and we know that these + + align:start position:0% +another equations and we know that these + + + align:start position:0% +another equations and we know that these +are probabilities so PI 1 plus PI 2 have + + align:start position:0% +are probabilities so PI 1 plus PI 2 have + + + align:start position:0% +are probabilities so PI 1 plus PI 2 have +to be 1 and so now we're going to keep + + align:start position:0% +to be 1 and so now we're going to keep + + + align:start position:0% +to be 1 and so now we're going to keep +one of these two let's say this one I'm + + align:start position:0% +one of these two let's say this one I'm + + + align:start position:0% +one of these two let's say this one I'm +gonna write it here and we can rewrite + + align:start position:0% +gonna write it here and we can rewrite + + + align:start position:0% +gonna write it here and we can rewrite +it by saying that PI 1 times 1 over 2 + + align:start position:0% +it by saying that PI 1 times 1 over 2 + + + align:start position:0% +it by saying that PI 1 times 1 over 2 +equals PI 2 times 1 over 5 so now we're + + align:start position:0% +equals PI 2 times 1 over 5 so now we're + + + align:start position:0% +equals PI 2 times 1 over 5 so now we're +gonna take that replace PI 1 equals 2/5 + + align:start position:0% +gonna take that replace PI 1 equals 2/5 + + + align:start position:0% +gonna take that replace PI 1 equals 2/5 +of Pi to see the result of that and + + align:start position:0% +of Pi to see the result of that and + + + align:start position:0% +of Pi to see the result of that and +we're gonna use that PI 1 and replace it + + align:start position:0% +we're gonna use that PI 1 and replace it + + + align:start position:0% +we're gonna use that PI 1 and replace it +here so we end up by 2 times 2/5 plus 1 + + align:start position:0% +here so we end up by 2 times 2/5 plus 1 + + + align:start position:0% +here so we end up by 2 times 2/5 plus 1 +equals 1 which means that from here we + + align:start position:0% +equals 1 which means that from here we + + + align:start position:0% +equals 1 which means that from here we +get that pi 2 equals 5 plus 2/7 so 5 + + align:start position:0% +get that pi 2 equals 5 plus 2/7 so 5 + + + align:start position:0% +get that pi 2 equals 5 plus 2/7 so 5 +over 7 and then we use that replace it + + align:start position:0% +over 7 and then we use that replace it + + + align:start position:0% +over 7 and then we use that replace it +here and we end up adding PI 1 equals + + align:start position:0% +here and we end up adding PI 1 equals + + + align:start position:0% +here and we end up adding PI 1 equals +2/5 times 5 7 equals 2 7 and we check 5 + + align:start position:0% +2/5 times 5 7 equals 2 7 and we check 5 + + + align:start position:0% +2/5 times 5 7 equals 2 7 and we check 5 +plus 2 equals 7 so these are real + + align:start position:0% +plus 2 equals 7 so these are real + + + align:start position:0% +plus 2 equals 7 so these are real +probabilities so the priority that you + + align:start position:0% +probabilities so the priority that you + + + align:start position:0% +probabilities so the priority that you +find yourself at state 1 at time 1 + + align:start position:0% +find yourself at state 1 at time 1 + + + align:start position:0% +find yourself at state 1 at time 1 +trillion will be approximately 2 over 7 + + align:start position:0% +trillion will be approximately 2 over 7 + + + align:start position:0% +trillion will be approximately 2 over 7 +the priority that you find yourself at + + align:start position:0% +the priority that you find yourself at + + + align:start position:0% +the priority that you find yourself at +state 1 at time to trillions is again + + align:start position:0% +state 1 at time to trillions is again + + + align:start position:0% +state 1 at time to trillions is again +approximately 2 over 7 so essentially + + align:start position:0% +approximately 2 over 7 so essentially + + + align:start position:0% +approximately 2 over 7 so essentially +what we have here is the probability of + + align:start position:0% +what we have here is the probability of + + + align:start position:0% +what we have here is the probability of +being in that state 1 settles in a + + align:start position:0% +being in that state 1 settles in a + + + align:start position:0% +being in that state 1 settles in a +steady value that's what the + + align:start position:0% +steady value that's what the + + + align:start position:0% +steady value that's what the +steady-state convergence means it's + + align:start position:0% +steady-state convergence means it's + + + align:start position:0% +steady-state convergence means it's +convergence of probabilities not + + align:start position:0% +convergence of probabilities not + + + align:start position:0% +convergence of probabilities not +convergence of the process itself again + + align:start position:0% +convergence of the process itself again + + + align:start position:0% +convergence of the process itself again +the process will keep jumping back and + + align:start position:0% +the process will keep jumping back and + + + align:start position:0% +the process will keep jumping back and +forth but the steady state priority will + + align:start position:0% +forth but the steady state priority will + + + align:start position:0% +forth but the steady state priority will +settle to a given value here in 1 that + + align:start position:0% +settle to a given value here in 1 that + + + align:start position:0% +settle to a given value here in 1 that +will be 2 over 7 and the steady state + + align:start position:0% +will be 2 over 7 and the steady state + + + align:start position:0% +will be 2 over 7 and the steady state +priority in being in 2 will settle to 5 + + align:start position:0% +priority in being in 2 will settle to 5 + + + align:start position:0% +priority in being in 2 will settle to 5 +over 7 and finally in this example and + + align:start position:0% +over 7 and finally in this example and + + + align:start position:0% +over 7 and finally in this example and +marginally when we have a single class + + align:start position:0% +marginally when we have a single class + + + align:start position:0% +marginally when we have a single class +and no periodicity the initial state + + align:start position:0% +and no periodicity the initial state + + + align:start position:0% +and no periodicity the initial state +does not matter \ No newline at end of file diff --git a/czAWbZLxFNM.txt b/czAWbZLxFNM.txt new file mode 100644 index 0000000000000000000000000000000000000000..46d3485644fc8b6052e55851045600bbce29e6f3 --- /dev/null +++ b/czAWbZLxFNM.txt @@ -0,0 +1,3177 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high-quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: OK, OK, OK. + +Let's settle down. + +Weekend is over. + +Tomorrow, weekly quiz. + +Today I'll have office +hours 3:00 to 4:00. + +I have to go down to Washington, +so I've got to + +leave a little bit earlier +than normal. + +So I will be available +from 3:00 to 4:00 + +The lecture has started and +there's still way too much + +talking in here. + +Way too much. + +You know how much is too much? + +Any. + +Any. + +So last day, we started talking +about oxide glasses, + +and we reasoned that we could +have control of the properties + +by control of the composition. + +We started with a network +former, which is some oxide + +that has the capacity for +forming covalent bonds through + +a bridging oxygen. + +And then we wanted to drop the +processing temperature, and we + +did so by adding modifiers. + +Intermediates, we haven't talked +about and we're going + +to do that in just a moment. + +So if you look in the readings, +this is from + +archival notes that were written +by my predecessor, + +Professor Witt, these +are compositions of + +some typical glasses. + +I don't expect you know these +from memory, but I would + +expect you, if I gave you the +composition, explain to me why + +the various constituents +are there. + +So let's try few examples. + +The first one is soda-lime +glass. + +And you see it contains +silica, which + +is the network former. + +It contains sodium oxide, +calcium oxide, + +and magnesium oxide. + +And these are alkaline earth +oxides that are ionic, and so + +these are acting as network +modifiers because they're + +donating oxide anions +that go in and break + +the silicate chains. + +And then there's this Al203 and +that's sort of halfway in + +between, isn't it? + +Silica is Group 4, or +14, if you want to + +use the modern notation. + +Sodium is Group 1. + +Calcium, magnesium, Group 2. + +Alumina is Group 3, and it's +sort of halfway in between. + +It's amphoteric. + +It can either be a former +or a modifier. + +And in these instances, +depending on how much modifier + +is present, alumina can act +as an intermediate. + +And what's an intermediate do? + +An intermediate is +a covalent oxide. + +It's a covalent oxide, or an +oxide that can act as both + +covalent and ionic. + +But in this instance, it's +acting covalent oxide with a + +different coordination number. + +And what does that mean? + +Different coordination number? + +It coordinates-- + +remember last day I +showed you B2O3? + +Borate glasses? + +So they have a coordination +of three, whereas + +silicates have four. + +And what that means +is that there's + +going to be a mismatch. + +There's still strong covalent +bonds, but they don't fit + +quite right. + +And that's going to give +even more free volume. + +And that excess free volume, +through covalent bonds, gives + +you the ability to endure +thermal shock. + +So if you want to impart thermal +shock resistance in a + +glass, you give it lots of free +volume so it can take the + +rapid change in temperature. + +So it's a covalent oxide with +different coordination number. + +That is, nearest neighbors, in a +covalent sense, from that of + +the network former. + +So you can add a borate or +aluminate, what have you. + +And that'll give you thermal +shock resistance. + +And so alumina here is acting +as an intermediate. + +Let's go down here. + +There's borosilicate. + +borosilicate is the generic +term for Pyrex. + +So Pyrex is a trade name. + +Pyrex was invented by Corning, +and it contains silica as the + +network former. + +There's some sodium oxide, +potassium oxide-- + +in rather small amounts. + +You can see this isn't a heavily +modified network, but + +look at this. + +13% B2O3 and 2% alumina. + +That's the modifier. + +And what was the hallmark +of Pyrex? + +It had thermal shock +resistance. + +So you could take it out of the +oven and put it under cold + +water and it didn't shatter. + +And we have the same analogous +behavior for glass ware in the + +laboratory. + +For all room temperature and +low temperature work in the + +laboratory, we use Pyrex that +has this resistance to + +chemicals and resistance +to heat. + +This is the big one, here. + +And that gave birth to +functional crockery in the + +kitchen, where you could work in +glass instead of in metal. + +And down here we see glass-- + +let's see, well, here's one. + +Light flint optical. + +See, that's 54%. + +It's down to 54% silica. + +And look at this-- boatloads +of lead oxide. + +And the lead oxide is acting as +a modifier and also changes + +the index of refraction. + +It modifies so much that we +have almost down to the + +orthosilicate. + +So that the chains are modified +to the point where + +they're almost all terminals. + +There's very little of this, +and most of it is just + +terminal oxygens. + +And that means that it's more +nearly crystalline, and + +therefore, you can cut it. + +And this is the lead crystal. + +Lead crystal has that +high value. + +So you can see how +that comes out. + +And this is also taken +from the reading. + +It's a plot of viscosity +versus temperature. + +Only it's a logarithmic plot. + +And what do you see? + +Here's pure silica. + +That's SiO2. + +And if I want to take it down +to the point where, if the + +viscosity goes down, you +have the ability to + +work with the glass. + +So if I want to melt silica, +I've got to way, way up here. + +Over 2,000 Centigrade. + +So if I want to make bottles, if +I want to make cookware, I + +don't want to run a lehr +at this temperature. + +Lehr. + +L E H R. + +It's where you melt glass. + +Lehr. + +I don't want to run a lehr +at this temperature. + +But you can see if I add +modifier, the more modifier + +that I add, the more I +break the network. + +So increasing modifier +decreases network + +connectivity, and that means I +can go to a lower temperature + +and get the same level +of fluidity. + +So there's a whole bunch of +definitions here that I'm not + +going to go over. + +You'll have this slide. + +But basically, it's just +different points in + +processing. + +So if you go up here. + +Strain and annealing. + +I mean, these are very, very-- + +you're especially working with +solid, whereas softening + +point, you start getting +the glass to flow. + +And the working point, that's +the viscosity that + +you have to get below. + +Otherwise, the glass is going +to be to resistant to flow. + +You want to get the glass tacky +so that you can put it + +into an injection mold, shape +it, as they do with bottles. + +They take a blob of glass and +boom, they just throw it into + +a mold and it sprays out. + +And if you've got the right mass +and the right spinning, + +it makes the wall thickness +proper. + +But you can imagine, if the +glass is really, really + +viscous, it's not going +to flow well enough. + +If it's too fluid, it'll +drip all over. + +So there's an optimum +in there. + +And this is telling you +how to figure out what + +that optimum is. + +And you can see that as you +change the composition, here's + +the working value. + +This is the viscosity that you +have to get below which in + +order to work. + +And you can see that as you add +more and more modifier, + +you can take the temperature +and get it way, way down. + +So to work with silica you have +to be about around 2,000. + +With soda-lime you can +be down around 800. + +So that's going to cut your +energy costs, isn't it? + +And it's going to make +it easier to recycle. + +What's the point of recycling if +you consume as much energy + +to recycle as if you started +with virgin material? + +At least with virgin material +you can guarantee the quality + +of the feeds stock. + +So there's got to be +some big saving. + +All right. + +So that gives you a some sense +as to what we can do + +technologically with glasses. + +I want to show you one last +thing with glasses, and then + +we're going to move on +to another topic. + +You know, new week, new +day, new topic. + +So I want to go back +to this curve. + +So what am I showing you here? + +I'm showing you that as we +change the cooling rate, we + +change the amount of quenched-in +excess volume. + +So fast cooling quenches in more +of the liquid free volume + +than slow cooling does. + +That's why this V excess is +small here, whereas V excess + +is large here for +the other one. + +I'm going to use that in +glass strengthening. + +So I want to strengthen. + +Strengthening glasses. + +We're talking about silicates +or borates. + +Strengthening oxide glasses. + +Glass is a fantastic material. + +It's really good in compression, +but it's no good + +in tensions. + +You know this. + +If you try to bend glass, +it'll break. + +Why? + +Not because it doesn't +have dislocations. + +It's got strong covalent +bonds. + +But you know, suppose you want +to strengthen the windshield + +of your car so that +when a stone hits + +it, it doesn't shatter. + +What can we do to give +it added strength? + +So I'm going to show you two +ways, and both of them operate + +under this principle that +the yield stress-- + +this is the stress that will +break the glass, and I'm going + +to say the effective yield +stress, what you + +experience in life-- + +is equal to the sum of what I'm +going to call the natural + +yield stress, which is the basic +property of the glass. + +Plus, I'm going to increase +the surface stress. + +What I'm going to do is I'm +going to modify the surface, + +and I'm going to put an +additive stress at the + +surface, and that's going to +be a compressive stress. + +So that means now the effective +stress that I need + +to break the glass is going +to be greater than it + +otherwise would be. + +So the whole gambit here is +surface strengthening. + +Service strengthening, which +means surface modification. + +And I'm going to show you two +ways to modify the surface to + +bring the strength +of the glass up. + +The first way is thermal. + +Thermal treatment. + +And the thermal treatment is +to strengthen the glass. + +Well, let's see. + +Let's keep it in the context +of the windshield. + +The technical term +for this, the + +technological term is tempering. + +So what I'm going to show you +was how we can look at that + +volume versus temperature curve +and understand how we + +make tempered glass for +windshields and so. + +So I'm going to show you +a slab of glass. + +Here's a slab of glass. + +And we just got below the +softening point-- so T just + +less than T softening. + +So now this thing's going to +start, it's continuing to + +become more and more viscous and +getting closer and closer + +to glass transition +temperature. + +And what we're going to do is +we're going to introduce air + +jets at the surface +of the glass. + +What that's going to do +is it's going to cause + +accelerated cooling +at the surface. + +And the same thing happens on +both surfaces, so I'm going to + +cut this piece of glass in half, +and we're just going to + +look at the upper surface. + +The same thing happens +in a lower surface. + +So let's now blow this up. + +I'm just going to look at the +upper-half surface and I'm + +going to divide it +into two zones. + +This is the first level, +most primitive + +finite element analysis. + +Finite element analysis. + +I'm going to divide it in two, +and I'm going to say, this has + +got two zones. + +Two cooling zones. + +Here is the zone of +the center, OK? + +This is the center. + +And I'm going to call this +the inner portion. + +And then there's the +outer portion. + +Well, take a look at +this curve here. + +Which is going to have +slower cooling? + +In the center or near +the free surface? + +The slower cooling is in the +center and according to this + +graph, the slow cooling has +a smaller residual volume. + +I've written, V-interior. + +That's the green line. + +And then the upper one +is a yellow line. + +So the upper one where it's high +cooling, it's going to + +have a higher volume. + +So this is the second piece +of finite element. + +So I'm going to model +this one like so. + +So this is outer. + +And the same thing happens +on the other side, OK? + +So it's happening on +the bottom as well. + +But we're just looking +at the top because + +there's symmetry here. + +So you see what I've done? + +This is longer because that +graph says it wants to be + +occupying a larger volume. + +Problem is the glass +can't do this. + +I can do this with a piece of +chalk, but the glass isn't + +going to look like that. + +The glass is going to +have a flat edge. + +And how can it have +a flat edge? + +Because the bottom, here-- this +is not to scale, let's + +make it more to scale-- + +the top is a narrow zone and +the bottom is a big, thick + +zone, isn't it? + +So this big, thick zone, which +has a small volume, is going + +to pull on the thin upper +zone, which has a large + +volume, and pull it in. + +Can you see that? + +And it's going to cause +the introduction + +of compressive stresses. + +So we got to compressive +stresses simply using that + +graph and a little bit of air. + +So you take that graph, put +differential cooling, and now + +you've introduced compressive +stress. + +And that's all tempered +glass is. + +So the V-excess of the outer +layer is greater than V-excess + +of the inner layer, or the +interior, if you like. + +And why? + +Because the cooling rate, the +change of temperature with + +time of the outer zone, is +greater than the cooling rate + +of the inner or interior. + +And there it is. + +That's the beginning. + +And so now to fracture you have +to apply a greater stress + +then you would have otherwise. + +So that's good, and that +saves a lot of lives. + +There's another way. + +There's another way to surface +strengthen, and that's a + +chemical treatment. + +And again, what am +I trying to do? + +I'm trying to introduce a +compressive stress, but I'm + +going to use a chemical means. + +And this one is called +ion exchange. + +And this is used in +technology, too. + +So now I'm going to take +a piece of glass here. + +This is solid glass and let's +put some components in here. + +So I'm going to put some silica +as my network former. + +I'm going to put some +sodium oxide. + +And I'm going to put some +modifier, B2O3. + +So I got all three here. + +Former, modifier, +intermediate. + +And just to put a little skin +on the bones here, I want to + +show what the sodium oxide +actually looks like. + +Sodium oxide goes in as sodium +cations, and oxide anions. + +The oxide anions go in +and they break some + +of the silica chains. + +But the sodiums don't get +involved in that. + +They just sit around +as spectators. + +Now what I'm going to do is +I'm going to put this, I'm + +going to soak this +in molten salt. + +Soak in molten salt. + +This is huge area of +my own research. + +And the molten salt, one example +might be I'm going to + +take potassium chloride. + +Remember, we talked about making +aluminum or magnesium? + +This is one of the constituents +of the melt in + +which we make electrolytic +magnesium. + +Potassium chloride. + +And it exists as potassium +cations and chloride anions. + +Chlorine is green, +except we know-- + +you know, this is the way +chemistry books write it, but + +that's stupid because this is +isoelectronic with argon. + +And it's not green. + +I know. + +I've looked at this stuff. + +It's clear, colorless, +and transparent. + +The chloride ion has to be +clear and colorless. + +It's got a complete shell, +but the chemistry books + +will make it green. + +Anyway, here's the potassium +ion here. + +And there's a lot of +potassium ion here. + +There's no potassium ion +inside the glass. + +There's sodium ion in the glass, +there's no sodium ion + +in the molten salt. + +But these are both media +in which ions live. + +So can you see this is sort of +like the perfume bottle? + +Things move from high +concentration to low + +concentration. + +Some sodium wants to leave +and enter the melt. + +And some potassium wants +to leave the melt + +and enter the glass. + +And where's the potassium +going to go? + +It has to go where there +used to be sodium. + +What's the relative size +of potassium ion + +versus sodium ion? + +Potassium ion is bigger. + +So potassium ion goes and +occupies a site formerly + +occupied by sodium and causes +compressive stress, because + +you get all these big ions +jamming in there and that's + +going to lead to compressive +stress through ion exchange. + +So through ion exchange we +can raised the temp. + +Since r, the radius of potassium +is greater than the + +radius of the sodium, we get a +force fit, and this is how we + +got solution hardening. + +Hardening is the metallurgical +term for raising the strength. + +Hardening is equal to +strength going up. + +So we get hardening +by solution. + +So this is solution hardening. + +Solution hardening because the +potassium ion is in there. + +So we have surface. + +And this gives a lot +of strength. + +We do the same thing +metallurgically if you + +carburize the surface +of a piece of steel. + +Tool steels, for example, +surface carburized. + +So we get hard surfaces +that can cut. + +You say, well, why don't you +just put the carbon in all the + +way through? + +Well, then the tool bit +will be brittle. + +So you want something that's got +toughness in the center so + +it can take the impact, +but it's got surface + +hardness so it'll cut. + +And that's an engineered +material. + +We've got one set of properties +at the surface, and + +we've got another set of +properties in the bulk. + +And it's all brought to you +by control of chemistry. + +And then that's also control +of chemistry. + +OK. + +So I mean, I could talk more +and more and more. + +Glasses are just fascinating +things. + +But we've got to get moving. + +So we're going to move +to a new topic. + +We're going to move to +a new topic today. + +We're going to start talking +about kinetics. + +Kinetics. + +And what is kinetics? + +Kinetics is the topic that we +put into 3.091, because it's + +important, of course, but it's +all about the study of + +reaction rates. + +It's the study of reaction +rates and mechanism. + +So why do we study? + +Well, we study it because +I think it belongs here. + +But first of all, kinetics is +related to productivity and + +resource utilization. + +You've got two factories. + +One produces 200 units per time, +the other produces 100 + +units per time. + +The one that's producing 100 +units per time probably isn't + +going to be in business +that much longer. + +And it's all about understanding +how to get more + +throughput per unit time, and +that leads to competitiveness. + +So if you're interested in +international competitiveness, + +you've got to know something +about kinetics. + +The two go hand in glove. + +Second thing is energy +and the environment. + +A number of you have come to +talk to me after class, sent + +emails because you're interested +in energy and the + +environment. + +Efficient use of energy involves +understanding the + +kinetics so you can force +chemical change with the least + +amount of energy utilization and +do so in a way because its + +mechanism-- + +if there's two mechanisms that +allow you to get to the same + +end product, choose the one +that has the least toxic + +impact on the environment. + +Otherwise, you're going to have +to spend money to avoid + +the effluents, which then gets +you back up to number one. + +Your cost of doing business is +higher than the other guy. + +Guess what? + +You're creamed in +the marketplace. + +And lastly, societal. + +And this is one that excites +me, is kinetics leads to + +productivity, which keeps +factories open, which keeps + +people working. + +So through understanding +kinetics. + +You go and you look at places +in the United States where + +factories have closed. + +In many, many instances it was +because the technology lagged. + +If you could just keep +things going faster. + +You've got to make things-- you +know how fast you've got + +to make them go? + +You've got to make them go so +fast that even if the foreign + +workers are paid zero, you can +still beat them in the + +marketplace. + +That's your standard. + +So that's how you design +your processes. + +You design your processes so +that you can produce at very, + +very low cost. + +And there's a huge range +in reaction rates. + +You know, you can start +the range of + +rates, rates of reaction. + +At the one that you have +very, very slow. + +And way over here you have very, +very fast, all right? + +So on the slow end, you +have stuff that's + +sort of cosmic scale. + +Geological. + +And then over here, +what do we have? + +We have explosions. + +You might say, well, explosions +are usually bad, + +aren't they? + +Well, no. + +I can give you an example of +where explosion is used to + +your advantage. + +The airbag in the automobile. + +There is no pump, no mechanical +pump fast enough to + +inflate an airbag on demand. + +So how do we make those +airbags work? + +And I hope none of us ever +has to be present at the + +deployment of those airbags. + +But you know, just academically +let's talk about + +how they work. + +There's like an explosion that +occurs when you're driving. + +There's an accelerometer and +this is a key piece. + +The accelerometer has to make +a decision whether you're + +applying the brakes just because +you've lost focus and + +you're, you know, whoops! + +You've had that jerky brake. + +Or maybe this is one of those +holy-mackerel moments, and + +your jamming on the +brakes, and we'd + +better deploy the airbags. + +Once the accelerometer decides +that this is one of those holy + +you-know-what moments, it sends +an electric current + +through a wire, which then +raises the temperature to 300 + +degrees C and causes this +reaction to take place. + +When this reaction takes +place, this is a solid, + +nitrogen is a gas. + +So the gas has a much, much +higher volume than the solid + +and within milliseconds +you get inflation. + +Well, that's good and that +inflates the bag and prevents + +you from hitting the hard +parts of the car. + +But you see the other +byproduct? + +That's sodium. + +And if you look on your Periodic +Table, elemental + +sodium is liquid above +98 degrees Celsius. + +So now you've got +liquid sodium. + +There's no point preserving the +safety of the occupants of + +the car just to cover them +with liquid sodium. + +So we better do something +about that. + +So being chemists, what we do +is we add potassium nitrate + +inside the bag, as well. + +so. + +That that sodium is mopped up +with potassium nitrate, which + +converts it to sodium oxide, +potassium oxide, and a little + +more nitrogen. + +[BLOWING SOUND EFFECT] + +Keep the bag nice and firm. + +But now what happens when the +Fires show up and they + +[SOUND EFFECT], + +you know, they start pouring +water on it. + +This turns into caustic. + +So now you're going to get +covered and wet lye. + +So that's probably not +too good, either. + +Just remember, you've been +physically saved from smashing + +your skull on the tempered +windshield. + +So it's so far, so good. + +So now what? + +You want a mechanical, you +want a Newtonian death? + +Or do you want a Coulombic +death? + +I guess that's the +question, here. + +And so we're going to keep doing +some chemistry here and + +we're going to add silica. + +And what happens if we add +silica to sodium oxide + +potassium oxide? + +Well that's a network former, +these are network modifiers. + +We'll make an alkaline silicate +glass and that's OK + +because we put food +and beverages in + +alkaline silicate glasses. + +So everybody is happy. + +So that's all the chemistry that +goes on inside an airbag. + +And we've got to understand +the kinetics. + +So I hope I've whet +your appetite. + +OK, that's enough of that. + +Now let's get to +the real stuff. + +So let's write a general +chemical reaction. + +The general reaction. + +What's the formalism if we want +to set up the metrics? + +So I'm going to write just +a plain, old equation. + +This is the classical +P-Chem stuff. + +Little a moles of A, plus little +b moles of B go to + +little c moles of C plus +little d moles of D. + +So this could have +been lecture two. + +Just a straight chemical +reaction. + +Remember we were studying +stoichiometry? + +So the constituents of the left +side of the equation are + +called the reactants, whereas +on the right side of the + +equation we have the products. + +And what kinetics gives us, +kinetics tells us the rate of + +conversion. + +Or the rate of reaction. + +I'm using all these terms +so you understand their + +equivalent. + +So we can write something like +this where the conservation of + +mass kicks in. + +So I can't make products +any faster + +than I consume reactants. + +There's no sources +or sinks here. + +When I lose reactants, +I make products. + +So I'm going to say, the rate of +change of the total mass of + +the reactants-- this +is summation sign-- + +I'm just saying the rate of +change of the sum of all of + +the reactions must equal +the rate of change. + +So the loss rate of reactants +must equal the gain rate of + +all of the products. + +That's just simple +stoichiometry. + +Or some people call this +conservation of mass or Law of + +Mass Action, what have you. + +And then we count by +concentration, usually. + +Just reminder. + +This is lowercase c. + +So this is the concentration +of species i + +goes as the mole number. + +n is mole number divided by +the volume of the reactor. + +So this would be in moles +per meter cubed if + +we were in SI units. + +So therefore the rate of change, +the ci by dt, is + +really the rate of change of +mole number, isn't it? + +It's moles of i disappearing, +but the volume + +doesn't change, typically. + +And then the last thing is we +can use this idea up here that + +concentration of products can +only equal the loss rate of + +the reactant. + +So I can write, term by term, +the normalized rate loss of + +the concentration of a divided +by its stoichiometric + +coefficient, for example, would +equal the normalized + +weight gain, or pardon me, the +concentration gain of the + +concentration of d. + +So this is just saying a +disappears no faster than d + +appears, mediated by the +stoichiometric coefficients. + +So this is just Law of Mass +Action, which is stoichiometry + +in motion, isn't it? + +That's all it is. + +Now here comes the cool +thing kinetic theory. + +We look at any reaction, I can +tell you right now what it + +looks like. + +If I applied concentration of +i as a function of time, I + +start off with some value c +naught, some initial value, + +and it just attenuates. + +We know that's going to happen +as we consume the-- it falls + +and there's some +curvature here. + +What we're trying to do next is +to give some mathematical + +representation to this. + +Can we come up with a +mathematical formulation of + +the shape of that curve? + +And we can, and here's +the central + +tenet kinetic of theory. + +Kinetic theory says that the +reaction rate can be expressed + +in terms of a driving force. + +And that driving force is the +instant concentration. + +OK. + +These are lofty words. + +I'll show you what it means +with illustration. + +So that's the overall idea. + +So now let's say that the rate +of change, the instant rate of + +change of concentration ci, is +proportional to the instant + +value of the concentration. + +And you know, the concentration + +is changing, right? + +As the concentration +decreases, the + +rate of change decreases. + +So just this alone, this idea +alone would rationalize a + +curve like that. + +As the concentration falls, +the rate of change falls, + +which means the concentration +falls, which means-- + +and raised to some power-- + +it's not linear, necessarily-- + +raised to some power. + +There's a power law +at work here. + +So now let's do this +one more time. + +I'm going to write it +mathematically. + +But I want you to first see +the word, concepts. + +So let's write it +mathematically. + +That means minus dci by dt-- + +so this is time rate a change of +concentration i, the minus + +means it's falling-- + +is equal to the concentration +of i raised to some power n. + +This is order reaction. + +It's not mole number +over there. + +You've got to be pluralistic +today. + +n is going to be used +in different ways. + +So this is called order +of reaction. + +And there's a constant. + +See up there? + +It's a proportionality. + +Here it's an equal sign, +thanks to the constant. + +And this is called the +rate constant. + +And this what all I need +for plant design. + +Suppose I'm running a chemical +plant and I'm taking a plus b + +and making c plus d and the +management says, we want to + +double the rate of +productivity. + +So you go, I know what to do. + +We'll increase the +concentration. + +They say, by how much? + +Well, this allows you, if you +know the value of k and n, you + +want to double this? + +Then you know what to do here. + +It's not necessarily double +the concentration, Because + +this is a 1.5 power. + +By the way, this doesn't +have to be an integer. + +Could be anything. + +Could be not necessarily integer +and must be determined + +by experiment. + +You can't look at an equation +and say, oh, that's going to + +be second order because +there's a + +two in front of something. + +So here we are, plant +designers. + +And the management wants +to know, how do + +we make things happen? + +So I'm going to go back to that +equation over there and + +I'll say that most generally, +the rate of change of + +concentration of a will then go +as rate constant times the + +concentration of a. + +See, the rate of change +goes as something + +to the power alpha. + +But it could also be +influenced by b. + +So I'm going to put-- this +is the most general form. + +Then once you make your +measurements, a lot + +of these fall out. + +I'm even going to put c +I'm going to put d. + +Everything was in +that equation. + +You might say, well, +wait a minute. + +How can the rate of consumption +of a be influenced + +by the concentration of d? + +d is a product. + +I'll give you two examples. + +One is that d, when I'm making +d, d happens to have some + +catalytic value. + +So when I start making a convert +to d, d catalyzes the + +reaction, which makes it go +faster, which makes more d, + +which makes the reaction go +faster, in which case this is + +going to have a profound +effect. + +And unfortunately, there are +some other situations where a + +converts to d and d retards +the reaction. + +And so I start off with pretty +decent conversion efficiency, + +but as I make more and more d, +the d chokes the reaction, in + +which case the value here is +going to have negative + +implications. + +So that's why you write it most +generally, and then you + +go and you make some +measurements in an experiment, + +and you figure out +what these are. + +Some of them might be zeroes, +and away you go. + +So I'll give you an +example of one. + +Here's one. + +It's Monday after Halloween, +so we'll get + +something kind of toxic. + +This was the manufacture of +phosgene that was banned by + +international convention. + +It was used as one of the toxic +gases for trench warfare + +in World War I. + +So it's made by the +reaction of carbon + +monoxide and chlorine. + +COCL2. + +This is called phosgene. + +It's very bad stuff. + +I used it, actually, +in my research. + +It has really good dehydration +properties for salts. + +If you've got any moisture in +potassium chloride, this'll go + +after it and turn the water into +carbon dioxide and HCl. + +But you've got to be really, +really careful with this. + +Gas leaks lead to a bad +day at the lab. + +All right, this was banned. + +It's still use by tyrants +throughout the world, and + +that's why we have international +war tribunals. + +So here's the kinetics of it. + +Here's the kinetics of it. + +dc by dt. + +So this is the rate of +consumption of carbon monoxide + +determined by experiment goes as +the concentration of carbon + +monoxide and the concentration +of chlorine raised + +to the power 3/2. + +So what I've done +is mimic here. + +So in this case, gamma +and delta are 0. + +Gamma equals delta equals 0, and +it looks like beta equals + +1.5 and alpha equals 1. + +So I would say that this +reaction is first order in + +carbon monoxide of order +1.5 in chlorine, or + +overall, of order 2.5. + +Because, right? + +This is the order of reaction. + +This is c to the power +1, isn't it? + +We don't write the 1. + +This is great. + +So we know, to increase the rate +of reaction we increase + +the concentration. + +There's another way to increase +the rate of reaction. + +What else can we do to increase +the rate of reaction? + +Increase the temperature. + +Things go faster at higher +temperatures. + +Again, how? + +How much? + +Suppose I said, I want to double +the rate of reaction. + +Do I double the temperature? + +Do I raise the temperature +by 10 degrees? + +How do I do that? + +So to increase rate of reaction, +we can increase + +temperature. + +But how? + +And by the way, where +is temperature here? + +I don't see temperature. + +I don't see temperature +in this rate equation. + +You could say, well, if you +increase the temperature + +you're going to increase +the gas volume. + +But that's piddling +effect, right? + +If I double the temperature, +I double the gas volume. + +It doesn't change +the mole number. + +The temperatures in here. + +That's where the temperature. + +Increase temperature, +which then + +operates on the rate constant. + +That's the only place left +in that formalism. + +But what's the quantitative +value? + +Quantitative value was +annunciated to us in 1889 by + +the Swedish chemist Arrhenius. + +And what Arrhenius found, he +found that the rate constant + +varied with temperature in +the following manner. + +Rate constant goes as the +exponential of the ratio of + +minus some quantity call the +activation energy e sub a-- + +I'm going to tell you what +that means in a minute-- + +divided by the ratio of the +product of the Boltzmann + +constant and temperature. + +And there's a constant of +proportionality which we + +denote A in honor +of Arrhenius. + +Or another way to write this +is A times exponential-- + +are you familiar with this? + +Instead of writing e to the +something, if there's a messy + +argument up here you +can write it exp. + +This is the same as this minus +ea over the ratio of Boltzmann + +constant and temperature. + +So what's in here? + +What's in here? + +Boltzmann constant temperature, + +we've seen that already. + +What's the Boltzmann constant +temperature product? + +That's the environment. + +That's the energy of +the environment. + +So this is the final +environment. + +And this thing up on top, +ea, is a barrier. + +It's a barrier. + +Remember we saw the band gap? + +Same idea. + +Those ideas go all through +physical chemistry. + +You got thermal energy that +allows you to do this 10 + +trillion times a second. + +Everybody in this room +is doing this 10 + +trillion times a second. + +That's what kT is. + +And then there's a +barrier energy. + +Every once in a while +something happens. + +Sometimes one in a million, +sometimes one in a billion. + +Whatever. + +What Arrhenius found was this +relationship, which means we + +could plot the variation +of the rate constant. + +This is a mess, right? + +This is an exponential-- + +look, the eye can only +see straight lines. + +What if I show you this? + +What's that mean? + +I don't know. + +Is that first order? + +Second order? + +Is that Lagrangian? + +Is that exponential? + +I don't know. + +I know it's a curve. + +But what's this? + +I know what that is. + +And you know what that is. + +And you can tell goodness +of fit. + +This is what science +is all about. + +Forget all the other stuff. + +You know, all that UROP stuff. + +You're going to work in a +lab and discover stuff. + +Forget that. + +This is what it's about. + +You got data. + +Data are all over the map. + +Here's the thing-- + +I need to come up with some +f function here versus a g + +function here that linearize +my data. + +That's all science is about. + +And how do I get to f and g? + +Well, there's two ways. + +One is trial and error. + +The other way is physical +understanding. + +And this is what Arrhenius +taught us. + +Arrhenius taught us that the f +function for how k varies with + +temperature, right? + +The problem, I'm trying +to say, k versus t. + +That's what I'm trying to do. + +And if I plot k versus +t I get a curve. + +No good. + +Instead, if I plot some f of +k versus g of t, I get a + +straight line. + +And this is all science. + +So what's f of k? + +The natural logarithm +of k, right? + +If I've got k equals a +exponential, I take the + +natural log of this, and the +natural log of an exponential + +is just the argument. + +And what's in the argument? + +What's the T function? + +1 over T. + +So if I plot the natural log of +k versus the reciprocal of + +the absolute temperature, I get +a straight line and its + +slope is minus ea, forgive me, +minus ea over k-Boltzmann. + +Minus ea over k-Boltzmann. + +So now it's linearized and I can +look at that and within an + +instant, anybody in this room +can look at and say, the data + +conform or they don't. + +They don't. + +So now let's think about this. + +We say well, what's the +value of this barrier? + +It's called activation energy. + +This barrier energy is called +activation energy. + +ea is called the activation +energy. + +And it typically, it varies, +but it has values-- + +just to give you a sense-- +about 1 electron volt. + +1 electron volt, which you +know now is about 100 + +kilojoules per mole, isn't it? + +I hear the chorus of yesses. + +1 electron volt. + +What is thermal energy? + +What's kT? + +kT at room temperature, +k-Boltzmann at room + +temperature is about 1/40 +of an electron volt. + +Now, we are chemical machines. + +This conversation is occurring +because all sorts of chemical + +processes are at work +in me and you. + +And how's that happening? + +When all we've got to suck out +of the environment is 1/40 of + +an electron volt and we need on +the order one electron volt + +to drive certain processes. + +I guess we're all dead. + +Any ideas? + +Ay yay, yay. + +You guys need-- + +what's that thing? + +You've got to call your +lifeline or something? + +Come on. + +How does anything happen? + +How do we get-- + +Why does anything happen +in this world? + +Why should anything happen in a +world with an environment of + +1/40 of an electron volt? + +AUDIENCE: Catalysts. + +PROFESSOR: Oh, catalysts. + +Catalysts. + +Yeah, yeah. + +I just went to the catalyst +store and I got catalysts. + +Come on. + +AUDIENCE: Potential energy. + +PROFESSOR: Oh, potential +energy. + +Jeez, this is good. + +Who can give me the +wackiest answer? + +Can anybody give me +the right answer? + +How come anything +is happening? + +Over here. + +Again? + +AUDIENCE: Distribution +of temperature. + +PROFESSOR: Thank you. + +Thank you. + +For a moment I thought +we were all dead. + +At some level we were. + +So, yeah, it's +Maxwell-Boltzmann. + +It's this, isn't it? + +And here's room temperature. + +And here is 1 electron volt. + +And this is it. + +And if you use this and you put +it back to there, pretty + +soon you derive the Arrhenius +equation. + +And if you increase +the temperature + +you know what happens. + +After you increase the +temperature, this. + +Time to use a hot +color or chalk. + +So now this is T2 +greater than T1. + +That's what's going on. + +That's what's going on. + +So now what is this +activation energy? + +What is the meaning of it? + +You know, I've told you there's +a barrier energy. + +What does it mean? + +Well, you go to the textbook, +you see goofy stuff like this. + +And this is not a slam +against the textbook. + +This is a slam against all +chemistry textbooks, because + +they all write this +stupid stuff. + +You see? a plus b goes c plus +d, the energy falls and you + +have to go over this +activated complex. + +You memorize it, and I ask you +to repeat, it and we leave the + +room and we think, wow, we +know physical chemistry. + +There's nothing here. + +This is nothing. + +This is stupid. + +Now this is a little +bit better. + +Can you see this? + +This is the Maxwell-Boltzmann. + +This is actually a beautiful +graph up to a point. + +See the Maxwell-Boltzmann? + +Low temperature, high +temperature. + +Only they've turned this +thing on its side. + +See? + +And there's the energy +you need to get over + +the activated complex. + +You see what's wrong +with this graph? + +What's wrong with it? + +AUDIENCE: The product. + +PROFESSOR: Yeah, the product +is at a higher + +level than the reactants. + +I looked at that and +I thought, whoa! + +I guess you'll activate them, +but they won't go anywhere. + +Anyway, so this is all stupid. + +What can we do? + +What can we do? + +So I decided to give you +a mechanical analogy. + +So imagine this is +the loudspeaker. + +Can you say the x? + +People in the back, +can you see the x? + +Give me a thumbs up. + +Great eyes. + +All right. + +So what do we see here? + +The center of mass, I've +indicated here. + +All right. + +So this is in a certain +energy state. + +Let's get the right +graph up there. + +This is awful. + +All right. + +So this is a plus b. + +Now this is c plus d. + +You see, the center +of mass fell. + +It's lower. + +It's closer to the table +than it is here. + +Can you see when I go like +this, the photon goes? + +Watch this. + +Yeah, only I can see it. + +Your eyes don't go to that +end of the spectrum. + +All right. + +But what's wrong with it? + +So why does the box +not fall over? + +Why does it not fall over? + +We agreed that this is a lower +energy state, and it is. + +You're correct. + +So why does the box manage to +stay here and not fall over? + +AUDIENCE: [INAUDIBLE PHRASE] + +PROFESSOR: Exactly. + +This is the box at 0 Kelvin. + +Now we start raising the energy +of the box, it starts + +doing this. + +Because above 0 Kelvin, +it vibrates. + +The higher the temperature, +the greater the vibration. + +But we're still in trouble here, +you see, because you've + +only got 1/40 of an +electron volt. + +So now we invoke distribution. + +I don't know what's happening +with any box. + +Heisenberg tells me that. + +I don't know what's happening +to any box. + +But if I take Avogadro's number +of boxes I'll get this + +distribution. + +And some boxes will vibrate +very little. + +And some boxes will +vibrate a lot. + +And what's the critical +level of vibration? + +It's to get to here. + +Because once it gets to here +it's downhill all the way. + +And that would be the +activation energy. + +And the fraction of boxes that +get to the value of activation + +energy tip over and then I +restore the distribution, + +because now this one's out of +the game and now I distribute + +that energy over the +remaining ones. + +And as I increase the +temperature, the amplitude of + +the vibration increases, the +average increases, the + +fraction in that red zone +increases, and at some + +temperature it's so, so hot that +they actually do this, in + +which case I have equilibrium. + +The two states are +in equilibrium. + +So that's it. + +This is what's going on. + +So in three space, you can't go +from here to here without + +going to here. + +You can try going this way so +you-- no, you have to do this. + +It still has to be mechanically +activated so we + +can show that this is what +activation means. + +So we can plot-- + +this deserves it's own board-- + +so we will plot something +like this. + +And now you'll see this. + +Sometimes they write +this in the books. + +It's kind of goofy. + +But they write stuff +like this. + +This is some kind of an +energy coordinate. + +This is an energy coordinate. + +And this is called a reaction +coordinate. + +OR sometimes they write +extent of reaction. + +Again, some P-Chem term. + +They usually use Greek C just +to make it lofty, but it's + +meaningless. + +And then so you write like +this-- reactants here, + +products here, and this is +exactly what we're seeing. + +What do we see? + +We see this. + +Here we have the box +sitting like so. + +And then over here we have +the box sitting like so. + +And right here we have +the box up like so. + +And so now you have, here's +the initial energy. + +This is the energy +of the reactants. + +E of the reactants. + +This is E of the products. + +So then this distance +here must be + +delta E of the reaction. + +And what's this? + +That's the activation energy. + +I have to come up with this; +otherwise, I can't make the + +box fall over. + +So this is ea to go from here +up onto the corner. + +And now you understand what +all this stuff means. + +So that's here. + +And this is the activated +complex. + +What's an activated complex? + +It's a box on its edge +ready to fall over. + +That's what it is. + +All right. + +I think we're out of time, so +let's cut to the end here. + +What've we got. + +Oh, just some plots. + +We'll get to that next day. + +All right. + +So I want to show +you a little bit + +about first-order reactions. + +This is radiocarbon dating. + +n equals 1. + +And strictly speaking, this is +not a chemical reaction, but + +it is first order. + +So I'll lump it in here. + +So this is a nuclear reaction. + +And what happens in the +upper atmosphere? + +Radioactive carbon produced by +cosmic rays, which generate + +neutrons in the upper atmosphere +and then those + +neutrons attack nitrogen +to make carbon 14. + +That's the radioactive +form of carbon. + +Remember? + +It's present in one part per +trillion, if you look on your + +Periodic Table for +the isotopes. + +Now carbon 14 enters +the carbon cycle. + +And so in all of us and in all +living organisms the ratio of + +carbon 14 to carbon 12 is +one part per trillion. + +And carbon 13 is also present. + +I don't know. + +What is it? + +1 point something percent? + +The thing is, the carbon +14 is radioactive. + +And it decays. + +Like this. + +But what happens after +somebody dies? + +Well, they stop exchanging +nutrients with the + +surroundings. + +They stop breathing, so their +carbon level is pegged as it + +was at the time of death. + +And now it's a one0way street. + +It's just carbon decay. + +And it turns out you can measure +the ratio of carbon 14 + +to carbon 12 to determine the +age, which is given by 5,730 + +years, which is the inverse +of the rate constant. + +Now, you can't use this for +crime scene investigations, + +but certainly you can start +dating things hundreds of + +years old, not hundreds +of minutes old. + +So there's a whole bunch of +other things that can be used, + +not just carbon. + +So this is radiochemical +dating. + +And these are used in trying to +nail down art forgeries and + +all sorts of things. + +All right. + +So here, you can see these. + +These have all been +radiocarbon dated. + +You know, the Dead Sea Scrolls +were radiocarbon dated and + +they look like they're from +about 2,000 years ago. + +Makes sense. + +You go out over here. + +They they found these Indian +sandals from Oregon, and then + +they looked on an electron +microscope, and they found + +something on the sandals that +looks a little bit like that. + +That's a Nike swoosh. + +I don't know. + +You people are so-- + +All right. + +So now I want to show you +the Shroud of Turin. + +The Shroud of Turin, as you may +know, for a long time was + +reputed to be the burial shroud +of Jesus Christ. And + +this is taken from the National +Geographic back in + +the late '80s. + +Back in the late '80s, they +did a major study on it. + +So this is the artist rendition +of how the shroud + +might have been wrapped +around a body. + +The question is, what's +the date of this? + +So we can use radiocarbon +dating. + +And so here's the formation +of carbon 14. + +Carbon 14 exchanges with +carbon 12 in flax. + +So it's got one part +per trillion. + +When the flax is harvested the +carbon 14 starts to decay. + +And then we look at +the weaving of the + +shroud and so on. + +And they had three different +labs, they took samples from + +the shroud. + +And they concluded +that the shroud + +dates from this period-- + +1260 to 1390. + +And the first time it was +mentioned in the literature + +was around 1354. + +So everything seems to make +sense that this is not the + +burial shroud of Jesus Christ. +It's something that has + +importance to certain members of +the Roman Church, but it's + +scientifically not. + +You know, this stirs up +a lot of passion. + +So people started saying, +wait a minute. + +Wait a minute. + +There was a fire in 1532 and +people repaired the shroud and + +they were using candlelight +and maybe the paraffin and + +mold and so on covered +the fibers. + +So now, are we looking at +the surface effect? + +How do we know what +really happened? + +The only way to know is to take +the whole shroud, put in + +a big Cuisinart and break +open the interior. + +Well, in point of fact, what +they did was take fibers and + +look inside. + +And I think as of the late '90s, +the Roman Church says, + +it's not the burial shroud +of Jesus, but it is + +an object of reverence. + +And I think it's a good +example of how science + +sometimes comes up against +spirituality, and we have to + +be careful how we handle it. + +It's a delicate matter. \ No newline at end of file diff --git a/dTGVt1enLlc.txt b/dTGVt1enLlc.txt new file mode 100644 index 0000000000000000000000000000000000000000..6707c27c87907572020d58cd1acea107bc2395a4 --- /dev/null +++ b/dTGVt1enLlc.txt @@ -0,0 +1,4875 @@ +align:start position:0% + +oh + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +anna jason + + align:start position:0% + + + + align:start position:0% + +she's a nutritionist from mit magical + + align:start position:0% +she's a nutritionist from mit magical + + + align:start position:0% +she's a nutritionist from mit magical +wow and she also has the origins + + align:start position:0% +wow and she also has the origins + + + align:start position:0% +wow and she also has the origins +wow + + align:start position:0% + + + + align:start position:0% + +can you say that again + + align:start position:0% + + + + align:start position:0% + +okay so i'm going to + + align:start position:0% +okay so i'm going to + + + align:start position:0% +okay so i'm going to +talk about mediterranean diet + + align:start position:0% + + + + align:start position:0% + +so you can get the sequel okay what is + + align:start position:0% +so you can get the sequel okay what is + + + align:start position:0% +so you can get the sequel okay what is +it + + align:start position:0% +it + + + align:start position:0% +it +what is this mediterranean diet that you + + align:start position:0% +what is this mediterranean diet that you + + + align:start position:0% +what is this mediterranean diet that you +hear so much about okay so there's no + + align:start position:0% +hear so much about okay so there's no + + + align:start position:0% +hear so much about okay so there's no +one particular official mediterranean + + align:start position:0% +one particular official mediterranean + + + align:start position:0% +one particular official mediterranean +diet people think it is but it's not + + align:start position:0% +diet people think it is but it's not + + + align:start position:0% +diet people think it is but it's not +it's really a food pattern that is + + align:start position:0% +it's really a food pattern that is + + + align:start position:0% +it's really a food pattern that is +shared by countries that room the + + align:start position:0% +shared by countries that room the + + + align:start position:0% +shared by countries that room the +mediterranean sea and you could put more + + align:start position:0% +mediterranean sea and you could put more + + + align:start position:0% +mediterranean sea and you could put more +countries here i didn't go crazy um you + + align:start position:0% +countries here i didn't go crazy um you + + + align:start position:0% +countries here i didn't go crazy um you +know you could add cyprus and you could + + align:start position:0% +know you could add cyprus and you could + + + align:start position:0% +know you could add cyprus and you could +add it i don't know if that's not a + + align:start position:0% +add it i don't know if that's not a + + + align:start position:0% +add it i don't know if that's not a +country but + + align:start position:0% +country but + + + align:start position:0% +country but +it's a region i'll say region so that's + + align:start position:0% +it's a region i'll say region so that's + + + align:start position:0% +it's a region i'll say region so that's +what we consider to be mediterranean + + align:start position:0% +what we consider to be mediterranean + + + align:start position:0% +what we consider to be mediterranean +that i'm going to get into the more + + align:start position:0% +that i'm going to get into the more + + + align:start position:0% +that i'm going to get into the more +specifics later + + align:start position:0% +specifics later + + + align:start position:0% +specifics later +long time ago 1958 ansel keys organized + + align:start position:0% +long time ago 1958 ansel keys organized + + + align:start position:0% +long time ago 1958 ansel keys organized +a seven-country study and those were the + + align:start position:0% +a seven-country study and those were the + + + align:start position:0% +a seven-country study and those were the +countries that were in his study and he + + align:start position:0% +countries that were in his study and he + + + align:start position:0% +countries that were in his study and he +had a hypothesis that + + align:start position:0% +had a hypothesis that + + + align:start position:0% +had a hypothesis that +a diet was very related to heart disease + + align:start position:0% +a diet was very related to heart disease + + + align:start position:0% +a diet was very related to heart disease +so he studied this for decades and then + + align:start position:0% +so he studied this for decades and then + + + align:start position:0% +so he studied this for decades and then +it did show that there was a lower + + align:start position:0% +it did show that there was a lower + + + align:start position:0% +it did show that there was a lower +prevalence of hypercholesterolemia + + align:start position:0% +prevalence of hypercholesterolemia + + + align:start position:0% +prevalence of hypercholesterolemia +that's high blood cholesterol and heart + + align:start position:0% +that's high blood cholesterol and heart + + + align:start position:0% +that's high blood cholesterol and heart +disease in populations of greece and + + align:start position:0% +disease in populations of greece and + + + align:start position:0% +disease in populations of greece and +italy especially greek island of crete + + align:start position:0% +italy especially greek island of crete + + + align:start position:0% +italy especially greek island of crete +and he attributed that to diet + + align:start position:0% +and he attributed that to diet + + + align:start position:0% +and he attributed that to diet +the cretins had like a 90 + + align:start position:0% +the cretins had like a 90 + + + align:start position:0% +the cretins had like a 90 +less + + align:start position:0% +less + + + align:start position:0% +less +heart attack or heart + + align:start position:0% +heart attack or heart + + + align:start position:0% +heart attack or heart +problems which is huge huge yeah so he + + align:start position:0% +problems which is huge huge yeah so he + + + align:start position:0% +problems which is huge huge yeah so he +thought oh it's their diet and what + + align:start position:0% +thought oh it's their diet and what + + + align:start position:0% +thought oh it's their diet and what +about their diet um he thought it was + + align:start position:0% +about their diet um he thought it was + + + align:start position:0% +about their diet um he thought it was +the fact yeah since then right there + + align:start position:0% +the fact yeah since then right there + + + align:start position:0% +the fact yeah since then right there +have been many more studies that have + + align:start position:0% +have been many more studies that have + + + align:start position:0% +have been many more studies that have +looked at this hypothesis we had the + + align:start position:0% +looked at this hypothesis we had the + + + align:start position:0% +looked at this hypothesis we had the +framingham heart study which was done + + align:start position:0% +framingham heart study which was done + + + align:start position:0% +framingham heart study which was done +here in massachusetts nurses health + + align:start position:0% +here in massachusetts nurses health + + + align:start position:0% +here in massachusetts nurses health +study i think that was still going on + + align:start position:0% +study i think that was still going on + + + align:start position:0% +study i think that was still going on +women's health initiative the + + align:start position:0% +women's health initiative the + + + align:start position:0% +women's health initiative the +conclusions and the discussion from all + + align:start position:0% +conclusions and the discussion from all + + + align:start position:0% +conclusions and the discussion from all +the studies in the papers + + align:start position:0% +the studies in the papers + + + align:start position:0% +the studies in the papers +are that plants plant fats + + align:start position:0% +are that plants plant fats + + + align:start position:0% +are that plants plant fats +yield better cardiovascular health than + + align:start position:0% +yield better cardiovascular health than + + + align:start position:0% +yield better cardiovascular health than +animal fats so it's the same thing + + align:start position:0% +animal fats so it's the same thing + + + align:start position:0% +animal fats so it's the same thing +that ansel keys discover to say that + + align:start position:0% +that ansel keys discover to say that + + + align:start position:0% +that ansel keys discover to say that +animal fats in the abundance that + + align:start position:0% +animal fats in the abundance that + + + align:start position:0% +animal fats in the abundance that +americans ate them not a good thing + + align:start position:0% +americans ate them not a good thing + + + align:start position:0% +americans ate them not a good thing +as i was looking at all the studies you + + align:start position:0% +as i was looking at all the studies you + + + align:start position:0% +as i was looking at all the studies you +know preparing for this + + align:start position:0% +know preparing for this + + + align:start position:0% +know preparing for this +i was amazed + + align:start position:0% +i was amazed + + + align:start position:0% +i was amazed +that i was amazed that + + align:start position:0% +that i was amazed that + + + align:start position:0% +that i was amazed that +hundreds and hundreds and hundreds of + + align:start position:0% +hundreds and hundreds and hundreds of + + + align:start position:0% +hundreds and hundreds and hundreds of +studies not one of them said oh + + align:start position:0% +studies not one of them said oh + + + align:start position:0% +studies not one of them said oh +my mediterranean diet is not good + + align:start position:0% +my mediterranean diet is not good + + + align:start position:0% +my mediterranean diet is not good +since 204 i looked at 13 studies + + align:start position:0% +since 204 i looked at 13 studies + + + align:start position:0% +since 204 i looked at 13 studies +there is strong evidence and these are + + align:start position:0% +there is strong evidence and these are + + + align:start position:0% +there is strong evidence and these are +from the studies themselves the kaboom + + align:start position:0% +from the studies themselves the kaboom + + + align:start position:0% +from the studies themselves the kaboom +the researcher's conclusion strong + + align:start position:0% +the researcher's conclusion strong + + + align:start position:0% +the researcher's conclusion strong +evidence that replacing saturated fats + + align:start position:0% +evidence that replacing saturated fats + + + align:start position:0% +evidence that replacing saturated fats +with monounsaturated fats is associated + + align:start position:0% +with monounsaturated fats is associated + + + align:start position:0% +with monounsaturated fats is associated +with reducing cardiovascular mortalities + + align:start position:0% +with reducing cardiovascular mortalities + + + align:start position:0% +with reducing cardiovascular mortalities +or illnesses around heart disease and + + align:start position:0% +or illnesses around heart disease and + + + align:start position:0% +or illnesses around heart disease and +how does it do that how how does + + align:start position:0% +how does it do that how how does + + + align:start position:0% +how does it do that how how does +the switching of the fats + + align:start position:0% +the switching of the fats + + + align:start position:0% +the switching of the fats +reducing bad cholesterol that's ldl + + align:start position:0% +reducing bad cholesterol that's ldl + + + align:start position:0% +reducing bad cholesterol that's ldl +cholesterol decreasing blood + + align:start position:0% +cholesterol decreasing blood + + + align:start position:0% +cholesterol decreasing blood +triglycerides and reducing inflammation + + align:start position:0% +triglycerides and reducing inflammation + + + align:start position:0% +triglycerides and reducing inflammation +those are some of the mechanisms that + + align:start position:0% +those are some of the mechanisms that + + + align:start position:0% +those are some of the mechanisms that +help + + align:start position:0% +help + + + align:start position:0% +help +reduce cardiovascular risk + + align:start position:0% +reduce cardiovascular risk + + + align:start position:0% +reduce cardiovascular risk +and also more recently you know diabetes + + align:start position:0% +and also more recently you know diabetes + + + align:start position:0% +and also more recently you know diabetes +has really become the prevalence in + + align:start position:0% +has really become the prevalence in + + + align:start position:0% +has really become the prevalence in +america and the world + + align:start position:0% +america and the world + + + align:start position:0% +america and the world +strong evidence that monounsaturated + + align:start position:0% +strong evidence that monounsaturated + + + align:start position:0% +strong evidence that monounsaturated +fatty acids + + align:start position:0% +fatty acids + + + align:start position:0% +fatty acids +are associated with improving type 2 + + align:start position:0% +are associated with improving type 2 + + + align:start position:0% +are associated with improving type 2 +diabetes it makes people less insulin + + align:start position:0% +diabetes it makes people less insulin + + + align:start position:0% +diabetes it makes people less insulin +systems so there's + + align:start position:0% +systems so there's + + + align:start position:0% +systems so there's +more health benefits + + align:start position:0% +more health benefits + + + align:start position:0% +more health benefits +it's not just cardiovascular health + + align:start position:0% +it's not just cardiovascular health + + + align:start position:0% +it's not just cardiovascular health +mediterranean diet + + align:start position:0% +mediterranean diet + + + align:start position:0% +mediterranean diet +has been + + align:start position:0% +has been + + + align:start position:0% +has been +reducing alzheimer's it's been shown to + + align:start position:0% +reducing alzheimer's it's been shown to + + + align:start position:0% +reducing alzheimer's it's been shown to +reduce parkinson's disease + + align:start position:0% +reduce parkinson's disease + + + align:start position:0% +reduce parkinson's disease +reduce the risk of depression reduce the + + align:start position:0% +reduce the risk of depression reduce the + + + align:start position:0% +reduce the risk of depression reduce the +risk of diabetes studies to show that + + align:start position:0% +risk of diabetes studies to show that + + + align:start position:0% +risk of diabetes studies to show that +mediterranean diet improves brain + + align:start position:0% +mediterranean diet improves brain + + + align:start position:0% +mediterranean diet improves brain +cognition so you think better which is + + align:start position:0% +cognition so you think better which is + + + align:start position:0% +cognition so you think better which is +good you remember things better so + + align:start position:0% +good you remember things better so + + + align:start position:0% +good you remember things better so +participating to the seminars yeah + + align:start position:0% +participating to the seminars yeah + + + align:start position:0% +participating to the seminars yeah +you're gonna be smarter tomorrow + + align:start position:0% +you're gonna be smarter tomorrow + + + align:start position:0% +you're gonna be smarter tomorrow +mediterranean diet has been shown to + + align:start position:0% +mediterranean diet has been shown to + + + align:start position:0% +mediterranean diet has been shown to +protect against some cancer's breasts + + align:start position:0% +protect against some cancer's breasts + + + align:start position:0% +protect against some cancer's breasts +and that should say prostate oh my god i + + align:start position:0% +and that should say prostate oh my god i + + + align:start position:0% +and that should say prostate oh my god i +said free state see what happens with + + align:start position:0% +said free state see what happens with + + + align:start position:0% +said free state see what happens with +spell check yeah okay + + align:start position:0% +spell check yeah okay + + + align:start position:0% +spell check yeah okay +so yeah um and living longer which is + + align:start position:0% +so yeah um and living longer which is + + + align:start position:0% +so yeah um and living longer which is +amazing there was one study that said + + align:start position:0% +amazing there was one study that said + + + align:start position:0% +amazing there was one study that said +people who follow meditate you know live + + align:start position:0% +people who follow meditate you know live + + + align:start position:0% +people who follow meditate you know live +like three years longer so + + align:start position:0% +like three years longer so + + + align:start position:0% +like three years longer so +oh and weight loss + + align:start position:0% +oh and weight loss + + + align:start position:0% +oh and weight loss +yeah weight management people who follow + + align:start position:0% +yeah weight management people who follow + + + align:start position:0% +yeah weight management people who follow +a more mediterranean style can be more + + align:start position:0% +a more mediterranean style can be more + + + align:start position:0% +a more mediterranean style can be more +successful at managing their weight than + + align:start position:0% +successful at managing their weight than + + + align:start position:0% +successful at managing their weight than +a low fat diet for instance + + align:start position:0% +a low fat diet for instance + + + align:start position:0% +a low fat diet for instance +okay so this is just a study just to + + align:start position:0% +okay so this is just a study just to + + + align:start position:0% +okay so this is just a study just to +show you that they there are hundreds of + + align:start position:0% +show you that they there are hundreds of + + + align:start position:0% +show you that they there are hundreds of +them that exist this is uh from + + align:start position:0% +them that exist this is uh from + + + align:start position:0% +them that exist this is uh from +nutrition journal it's recent + + align:start position:0% +nutrition journal it's recent + + + align:start position:0% +nutrition journal it's recent +people were following a mediterranean + + align:start position:0% +people were following a mediterranean + + + align:start position:0% +people were following a mediterranean +diet the people that found that followed + + align:start position:0% +diet the people that found that followed + + + align:start position:0% +diet the people that found that followed +the mediterranean diet more had less + + align:start position:0% +the mediterranean diet more had less + + + align:start position:0% +the mediterranean diet more had less +inflammation which is involved in + + align:start position:0% +inflammation which is involved in + + + align:start position:0% +inflammation which is involved in +disease + + align:start position:0% +disease + + + align:start position:0% +disease +reduce oxidative stress you know the + + align:start position:0% +reduce oxidative stress you know the + + + align:start position:0% +reduce oxidative stress you know the +free radicals higher circulating levels + + align:start position:0% +free radicals higher circulating levels + + + align:start position:0% +free radicals higher circulating levels +of antioxidants all which are associated + + align:start position:0% +of antioxidants all which are associated + + + align:start position:0% +of antioxidants all which are associated +with reduced risk of disease in general + + align:start position:0% +with reduced risk of disease in general + + + align:start position:0% +with reduced risk of disease in general +so that's one study with the mid diet + + align:start position:0% +so that's one study with the mid diet + + + align:start position:0% +so that's one study with the mid diet +here's the prostate cancer + + align:start position:0% +here's the prostate cancer + + + align:start position:0% +here's the prostate cancer +this was done in spain + + align:start position:0% +this was done in spain + + + align:start position:0% +this was done in spain +they looked at meta-analysis and they + + align:start position:0% +they looked at meta-analysis and they + + + align:start position:0% +they looked at meta-analysis and they +looked at a lot of studies and said here + + align:start position:0% +looked at a lot of studies and said here + + + align:start position:0% +looked at a lot of studies and said here +that they cited several characteristics + + align:start position:0% +that they cited several characteristics + + + align:start position:0% +that they cited several characteristics +of meta diet including highly data + + align:start position:0% +of meta diet including highly data + + + align:start position:0% +of meta diet including highly data +consumption of fruits vegetables grains + + align:start position:0% +consumption of fruits vegetables grains + + + align:start position:0% +consumption of fruits vegetables grains +tubers legumes olive oil is the main + + align:start position:0% +tubers legumes olive oil is the main + + + align:start position:0% +tubers legumes olive oil is the main +source of fats + + align:start position:0% +source of fats + + + align:start position:0% +source of fats +low intake of animal products + + align:start position:0% +low intake of animal products + + + align:start position:0% +low intake of animal products +and regular consumption of small fish so + + align:start position:0% +and regular consumption of small fish so + + + align:start position:0% +and regular consumption of small fish so +another study + + align:start position:0% +another study + + + align:start position:0% +another study +eating a diet with omega-3 fatty acids + + align:start position:0% +eating a diet with omega-3 fatty acids + + + align:start position:0% +eating a diet with omega-3 fatty acids +can improve insulin sensitivity and + + align:start position:0% +can improve insulin sensitivity and + + + align:start position:0% +can improve insulin sensitivity and +that's got to do with diabetes again + + align:start position:0% +that's got to do with diabetes again + + + align:start position:0% +that's got to do with diabetes again +here's another study adherence to + + align:start position:0% +here's another study adherence to + + + align:start position:0% +here's another study adherence to +mediterranean diet is associated with + + align:start position:0% +mediterranean diet is associated with + + + align:start position:0% +mediterranean diet is associated with +the risk of diabetes separate from the + + align:start position:0% +the risk of diabetes separate from the + + + align:start position:0% +the risk of diabetes separate from the +insulin eating a mediterranean-style + + align:start position:0% +insulin eating a mediterranean-style + + + align:start position:0% +insulin eating a mediterranean-style +diet rich in olive oil whole grains fish + + align:start position:0% +diet rich in olive oil whole grains fish + + + align:start position:0% +diet rich in olive oil whole grains fish +fruit may protect aging brains from + + align:start position:0% +fruit may protect aging brains from + + + align:start position:0% +fruit may protect aging brains from +damage associated with cognitive + + align:start position:0% +damage associated with cognitive + + + align:start position:0% +damage associated with cognitive +problems + + align:start position:0% +problems + + + align:start position:0% +problems +and so here's just a quick excerpt after + + align:start position:0% +and so here's just a quick excerpt after + + + align:start position:0% +and so here's just a quick excerpt after +reviewing the brain mris + + align:start position:0% +reviewing the brain mris + + + align:start position:0% +reviewing the brain mris +of the older people they found that + + align:start position:0% +of the older people they found that + + + align:start position:0% +of the older people they found that +people who followed the mediterranean + + align:start position:0% +people who followed the mediterranean + + + align:start position:0% +people who followed the mediterranean +diet more closely were up to 36 percent + + align:start position:0% +diet more closely were up to 36 percent + + + align:start position:0% +diet more closely were up to 36 percent +less likely to show brand damages + + align:start position:0% +less likely to show brand damages + + + align:start position:0% +less likely to show brand damages +here's another study + + align:start position:0% +here's another study + + + align:start position:0% +here's another study +from neurology and they're recent so + + align:start position:0% +from neurology and they're recent so + + + align:start position:0% +from neurology and they're recent so +again this was protecting against + + align:start position:0% +again this was protecting against + + + align:start position:0% +again this was protecting against +strokes + + align:start position:0% +strokes + + + align:start position:0% +strokes +so what is it about this mediterranean + + align:start position:0% +so what is it about this mediterranean + + + align:start position:0% +so what is it about this mediterranean +diet that can do it sounds like a + + align:start position:0% +diet that can do it sounds like a + + + align:start position:0% +diet that can do it sounds like a +miracle diet so the first thing the + + align:start position:0% +miracle diet so the first thing the + + + align:start position:0% +miracle diet so the first thing the +first big characteristic and i think + + align:start position:0% +first big characteristic and i think + + + align:start position:0% +first big characteristic and i think +everybody knows is the fact that the fat + + align:start position:0% +everybody knows is the fact that the fat + + + align:start position:0% +everybody knows is the fact that the fat +source is different in the mediterranean + + align:start position:0% +source is different in the mediterranean + + + align:start position:0% +source is different in the mediterranean +compared to us and western diets and it + + align:start position:0% +compared to us and western diets and it + + + align:start position:0% +compared to us and western diets and it +is olive oil and it's lots of olive oil + + align:start position:0% +is olive oil and it's lots of olive oil + + + align:start position:0% +is olive oil and it's lots of olive oil +mediterranean diets can be up to 40 + + align:start position:0% +mediterranean diets can be up to 40 + + + align:start position:0% +mediterranean diets can be up to 40 +50 calories from fat + + align:start position:0% +50 calories from fat + + + align:start position:0% +50 calories from fat +so it's a lot of fat that's not a + + align:start position:0% +so it's a lot of fat that's not a + + + align:start position:0% +so it's a lot of fat that's not a +low-fat diet but they're not fat you see + + align:start position:0% +low-fat diet but they're not fat you see + + + align:start position:0% +low-fat diet but they're not fat you see +so fat doesn't make you fat the big + + align:start position:0% +so fat doesn't make you fat the big + + + align:start position:0% +so fat doesn't make you fat the big +characteristic here and what ansel keys + + align:start position:0% +characteristic here and what ansel keys + + + align:start position:0% +characteristic here and what ansel keys +discovered + + align:start position:0% +discovered + + + align:start position:0% +discovered +was + + align:start position:0% +was + + + align:start position:0% +was +that or what his hypothesis was that it + + align:start position:0% +that or what his hypothesis was that it + + + align:start position:0% +that or what his hypothesis was that it +was + + align:start position:0% +was + + + align:start position:0% +was +this kind of fat that had healthy + + align:start position:0% +this kind of fat that had healthy + + + align:start position:0% +this kind of fat that had healthy +benefits + + align:start position:0% +benefits + + + align:start position:0% +benefits +and just so you know that's an omega + + align:start position:0% +and just so you know that's an omega + + + align:start position:0% +and just so you know that's an omega +omega-9 + + align:start position:0% +omega-9 + + + align:start position:0% +omega-9 +and i can also tell you that's pretty + + align:start position:0% +and i can also tell you that's pretty + + + align:start position:0% +and i can also tell you that's pretty +small but i just wanted to remind myself + + align:start position:0% +small but i just wanted to remind myself + + + align:start position:0% +small but i just wanted to remind myself +there's there's many other compounds in + + align:start position:0% +there's there's many other compounds in + + + align:start position:0% +there's there's many other compounds in +olive oil + + align:start position:0% +olive oil + + + align:start position:0% +olive oil +think of olive oil as like a fresh fruit + + align:start position:0% +think of olive oil as like a fresh fruit + + + align:start position:0% +think of olive oil as like a fresh fruit +nectar this is not an + + align:start position:0% +nectar this is not an + + + align:start position:0% +nectar this is not an +an oil that has been highly processed to + + align:start position:0% +an oil that has been highly processed to + + + align:start position:0% +an oil that has been highly processed to +get its fat like sesames and soy and + + align:start position:0% +get its fat like sesames and soy and + + + align:start position:0% +get its fat like sesames and soy and +those are made differently this is just + + align:start position:0% +those are made differently this is just + + + align:start position:0% +those are made differently this is just +the fruit and i have to mechanically get + + align:start position:0% +the fruit and i have to mechanically get + + + align:start position:0% +the fruit and i have to mechanically get +it out it's not with chemicals it + + align:start position:0% +it out it's not with chemicals it + + + align:start position:0% +it out it's not with chemicals it +shouldn't be anyone + + align:start position:0% +shouldn't be anyone + + + align:start position:0% +shouldn't be anyone +but so it's so it's got a lot of fresh + + align:start position:0% +but so it's so it's got a lot of fresh + + + align:start position:0% +but so it's so it's got a lot of fresh +compounds in there the fresher the + + align:start position:0% +compounds in there the fresher the + + + align:start position:0% +compounds in there the fresher the +better there were studies that say if + + align:start position:0% +better there were studies that say if + + + align:start position:0% +better there were studies that say if +you have fresh olive oil + + align:start position:0% +you have fresh olive oil + + + align:start position:0% +you have fresh olive oil +it's healthier for you than not so good + + align:start position:0% +it's healthier for you than not so good + + + align:start position:0% +it's healthier for you than not so good +quality olive oil okay so then + + align:start position:0% +quality olive oil okay so then + + + align:start position:0% +quality olive oil okay so then +mediterranean diets also have other fats + + align:start position:0% +mediterranean diets also have other fats + + + align:start position:0% +mediterranean diets also have other fats +in their diet they're not from olive oil + + align:start position:0% +in their diet they're not from olive oil + + + align:start position:0% +in their diet they're not from olive oil +they're not omega-9 they're omega-6 i + + align:start position:0% +they're not omega-9 they're omega-6 i + + + align:start position:0% +they're not omega-9 they're omega-6 i +know you've heard that and we never + + align:start position:0% +know you've heard that and we never + + + align:start position:0% +know you've heard that and we never +refer to this we always call this + + align:start position:0% +refer to this we always call this + + + align:start position:0% +refer to this we always call this +monounsaturated nuts and seeds sesames + + align:start position:0% +monounsaturated nuts and seeds sesames + + + align:start position:0% +monounsaturated nuts and seeds sesames +cashews walnuts + + align:start position:0% +cashews walnuts + + + align:start position:0% +cashews walnuts +those + + align:start position:0% +those + + + align:start position:0% +those +are considered polyunsaturated fats + + align:start position:0% +are considered polyunsaturated fats + + + align:start position:0% +are considered polyunsaturated fats +there's other fats in the diet fish + + align:start position:0% +there's other fats in the diet fish + + + align:start position:0% +there's other fats in the diet fish +those in the omega-3 polyunsaturated + + align:start position:0% +those in the omega-3 polyunsaturated + + + align:start position:0% +those in the omega-3 polyunsaturated +these are mono and these are + + align:start position:0% +these are mono and these are + + + align:start position:0% +these are mono and these are +polyunsaturated + + align:start position:0% +polyunsaturated + + + align:start position:0% +polyunsaturated +so fish is also very prominent in the + + align:start position:0% +so fish is also very prominent in the + + + align:start position:0% +so fish is also very prominent in the +mediterranean diet okay the other + + align:start position:0% +mediterranean diet okay the other + + + align:start position:0% +mediterranean diet okay the other +characteristic fresh fruits and + + align:start position:0% +characteristic fresh fruits and + + + align:start position:0% +characteristic fresh fruits and +vegetables are prominent they are not an + + align:start position:0% +vegetables are prominent they are not an + + + align:start position:0% +vegetables are prominent they are not an +afterthought the vegetables are the + + align:start position:0% +afterthought the vegetables are the + + + align:start position:0% +afterthought the vegetables are the +highlight + + align:start position:0% +highlight + + + align:start position:0% +highlight +of many meals + + align:start position:0% +of many meals + + + align:start position:0% +of many meals +there is meat in the mood training diet + + align:start position:0% +there is meat in the mood training diet + + + align:start position:0% +there is meat in the mood training diet +the portion is smaller + + align:start position:0% +the portion is smaller + + + align:start position:0% +the portion is smaller +it's just not always there living + + align:start position:0% +it's just not always there living + + + align:start position:0% +it's just not always there living +vegetarian meals + + align:start position:0% +vegetarian meals + + + align:start position:0% +vegetarian meals +so fresh fruits and vegetables are very + + align:start position:0% +so fresh fruits and vegetables are very + + + align:start position:0% +so fresh fruits and vegetables are very +very high and again this is part of the + + align:start position:0% +very high and again this is part of the + + + align:start position:0% +very high and again this is part of the +health benefits it's not just the fats + + align:start position:0% +health benefits it's not just the fats + + + align:start position:0% +health benefits it's not just the fats +so legumes uh and i by legumes i dried + + align:start position:0% +so legumes uh and i by legumes i dried + + + align:start position:0% +so legumes uh and i by legumes i dried +peas + + align:start position:0% +peas + + + align:start position:0% +peas +lentils beans + + align:start position:0% +lentils beans + + + align:start position:0% +lentils beans +the other thing that is left out of many + + align:start position:0% +the other thing that is left out of many + + + align:start position:0% +the other thing that is left out of many +much of the literature of fresh herbs + + align:start position:0% +much of the literature of fresh herbs + + + align:start position:0% +much of the literature of fresh herbs +and spices and i'll show you later that + + align:start position:0% +and spices and i'll show you later that + + + align:start position:0% +and spices and i'll show you later that +there are compounds in here there's + + align:start position:0% +there are compounds in here there's + + + align:start position:0% +there are compounds in here there's +vitamins there's minerals and i think + + align:start position:0% +vitamins there's minerals and i think + + + align:start position:0% +vitamins there's minerals and i think +that the key to the mediterranean diet + + align:start position:0% +that the key to the mediterranean diet + + + align:start position:0% +that the key to the mediterranean diet +is that + + align:start position:0% +is that + + + align:start position:0% +is that +all the foods there works + + align:start position:0% +all the foods there works + + + align:start position:0% +all the foods there works +synergistically oh and then there's the + + align:start position:0% +synergistically oh and then there's the + + + align:start position:0% +synergistically oh and then there's the +plain yogurt + + align:start position:0% +plain yogurt + + + align:start position:0% +plain yogurt +and cheese and those are fermented + + align:start position:0% +and cheese and those are fermented + + + align:start position:0% +and cheese and those are fermented +products i wouldn't say there's a lot of + + align:start position:0% +products i wouldn't say there's a lot of + + + align:start position:0% +products i wouldn't say there's a lot of +milk milk i do not see a lot of whole + + align:start position:0% +milk milk i do not see a lot of whole + + + align:start position:0% +milk milk i do not see a lot of whole +grains but it's there because of the + + align:start position:0% +grains but it's there because of the + + + align:start position:0% +grains but it's there because of the +literature and i think that other + + align:start position:0% +literature and i think that other + + + align:start position:0% +literature and i think that other +cultures use more like when you get more + + align:start position:0% +cultures use more like when you get more + + + align:start position:0% +cultures use more like when you get more +middle eastern turkey there's boulder + + align:start position:0% +middle eastern turkey there's boulder + + + align:start position:0% +middle eastern turkey there's boulder +etc but in greece italy we don't use + + align:start position:0% +etc but in greece italy we don't use + + + align:start position:0% +etc but in greece italy we don't use +whole grains they do now because they + + align:start position:0% +whole grains they do now because they + + + align:start position:0% +whole grains they do now because they +know it's supposed to be good but that's + + align:start position:0% +know it's supposed to be good but that's + + + align:start position:0% +know it's supposed to be good but that's +not i don't think that's i don't know if + + align:start position:0% +not i don't think that's i don't know if + + + align:start position:0% +not i don't think that's i don't know if +they were eating that in the 1950s maybe + + align:start position:0% +they were eating that in the 1950s maybe + + + align:start position:0% +they were eating that in the 1950s maybe +they were + + align:start position:0% +they were + + + align:start position:0% +they were +red wine is part of the mediterranean + + align:start position:0% +red wine is part of the mediterranean + + + align:start position:0% +red wine is part of the mediterranean +diet the big difference is + + align:start position:0% +diet the big difference is + + + align:start position:0% +diet the big difference is +they have much less saturated fat + + align:start position:0% +they have much less saturated fat + + + align:start position:0% +they have much less saturated fat +because they use foods and how do they + + align:start position:0% +because they use foods and how do they + + + align:start position:0% +because they use foods and how do they +get it it's because they don't eat a lot + + align:start position:0% +get it it's because they don't eat a lot + + + align:start position:0% +get it it's because they don't eat a lot +of meat their portion is small and they + + align:start position:0% +of meat their portion is small and they + + + align:start position:0% +of meat their portion is small and they +don't have it frequently like every day + + align:start position:0% +don't have it frequently like every day + + + align:start position:0% +don't have it frequently like every day +the other difference right is less salty + + align:start position:0% +the other difference right is less salty + + + align:start position:0% +the other difference right is less salty +and sweet processed foods america has + + align:start position:0% +and sweet processed foods america has + + + align:start position:0% +and sweet processed foods america has +lots of these cheeses potato chips + + align:start position:0% +lots of these cheeses potato chips + + + align:start position:0% +lots of these cheeses potato chips +pretzels just again i think that these + + align:start position:0% +pretzels just again i think that these + + + align:start position:0% +pretzels just again i think that these +and studies have shown + + align:start position:0% +and studies have shown + + + align:start position:0% +and studies have shown +these all of these fresh herbs and + + align:start position:0% +these all of these fresh herbs and + + + align:start position:0% +these all of these fresh herbs and +spices have health benefits they're not + + align:start position:0% +spices have health benefits they're not + + + align:start position:0% +spices have health benefits they're not +there just for flavor when you think + + align:start position:0% +there just for flavor when you think + + + align:start position:0% +there just for flavor when you think +about parsley lots of vitamin c vitamin + + align:start position:0% +about parsley lots of vitamin c vitamin + + + align:start position:0% +about parsley lots of vitamin c vitamin +a + + align:start position:0% +a + + + align:start position:0% +a +flavonoids + + align:start position:0% +flavonoids + + + align:start position:0% +flavonoids +these are compounds in foods that have + + align:start position:0% +these are compounds in foods that have + + + align:start position:0% +these are compounds in foods that have +health benefits and fresh garlic another + + align:start position:0% +health benefits and fresh garlic another + + + align:start position:0% +health benefits and fresh garlic another +very common thing it's not chopped + + align:start position:0% +very common thing it's not chopped + + + align:start position:0% +very common thing it's not chopped +already and it's not garlic powder like + + align:start position:0% +already and it's not garlic powder like + + + align:start position:0% +already and it's not garlic powder like +we would do here in the mediterranean + + align:start position:0% +we would do here in the mediterranean + + + align:start position:0% +we would do here in the mediterranean +diet these are all fish and there are + + align:start position:0% +diet these are all fish and there are + + + align:start position:0% +diet these are all fish and there are +dep sulphur compounds are helpful so in + + align:start position:0% +dep sulphur compounds are helpful so in + + + align:start position:0% +dep sulphur compounds are helpful so in +1992 the mediterranean diet you know we + + align:start position:0% +1992 the mediterranean diet you know we + + + align:start position:0% +1992 the mediterranean diet you know we +had our pyramid here then + + align:start position:0% +had our pyramid here then + + + align:start position:0% +had our pyramid here then +a group came out with a mediterranean + + align:start position:0% +a group came out with a mediterranean + + + align:start position:0% +a group came out with a mediterranean +diet pyramid so for those of you who + + align:start position:0% +diet pyramid so for those of you who + + + align:start position:0% +diet pyramid so for those of you who +like + + align:start position:0% +like + + + align:start position:0% +like +visuals this is the mediterranean diet + + align:start position:0% +visuals this is the mediterranean diet + + + align:start position:0% +visuals this is the mediterranean diet +on the bottom you know we're supposed to + + align:start position:0% +on the bottom you know we're supposed to + + + align:start position:0% +on the bottom you know we're supposed to +have the most of our foods come from + + align:start position:0% +have the most of our foods come from + + + align:start position:0% +have the most of our foods come from +here + + align:start position:0% +here + + + align:start position:0% +here +fresh vegetables grains + + align:start position:0% +fresh vegetables grains + + + align:start position:0% +fresh vegetables grains +olive oil they're grouped all together + + align:start position:0% +olive oil they're grouped all together + + + align:start position:0% +olive oil they're grouped all together +and then less protein + + align:start position:0% +and then less protein + + + align:start position:0% +and then less protein +less dairy and then + + align:start position:0% +less dairy and then + + + align:start position:0% +less dairy and then +meats and sweets are put in the same + + align:start position:0% +meats and sweets are put in the same + + + align:start position:0% +meats and sweets are put in the same +category which will feed very little + + align:start position:0% +category which will feed very little + + + align:start position:0% +category which will feed very little +yeah don't forget they have all this + + align:start position:0% +yeah don't forget they have all this + + + align:start position:0% +yeah don't forget they have all this +activity here too + + align:start position:0% +activity here too + + + align:start position:0% +activity here too +so this these are some mediterranean + + align:start position:0% +so this these are some mediterranean + + + align:start position:0% +so this these are some mediterranean +lifestyle and behaviors that i noticed + + align:start position:0% +lifestyle and behaviors that i noticed + + + align:start position:0% +lifestyle and behaviors that i noticed +myself when i go to greece all the time + + align:start position:0% +myself when i go to greece all the time + + + align:start position:0% +myself when i go to greece all the time +there's no such thing as eating in front + + align:start position:0% +there's no such thing as eating in front + + + align:start position:0% +there's no such thing as eating in front +of the tv or snacking that's not a + + align:start position:0% +of the tv or snacking that's not a + + + align:start position:0% +of the tv or snacking that's not a +concept i don't know if that's india in + + align:start position:0% +concept i don't know if that's india in + + + align:start position:0% +concept i don't know if that's india in +italy no you have your meals and you're + + align:start position:0% +italy no you have your meals and you're + + + align:start position:0% +italy no you have your meals and you're +done there's no + + align:start position:0% +done there's no + + + align:start position:0% +done there's no +no concept of that like oh well + + align:start position:0% +no concept of that like oh well + + + align:start position:0% +no concept of that like oh well +i in my practice here at medical that's + + align:start position:0% +i in my practice here at medical that's + + + align:start position:0% +i in my practice here at medical that's +a huge issue for us americans we're like + + align:start position:0% +a huge issue for us americans we're like + + + align:start position:0% +a huge issue for us americans we're like +oh what do i snack on at night people + + align:start position:0% +oh what do i snack on at night people + + + align:start position:0% +oh what do i snack on at night people +say + + align:start position:0% +say + + + align:start position:0% +say +i say well if you're not helping me + + align:start position:0% +i say well if you're not helping me + + + align:start position:0% +i say well if you're not helping me +don't stop uh they're sharing plates a + + align:start position:0% +don't stop uh they're sharing plates a + + + align:start position:0% +don't stop uh they're sharing plates a +lot of sharing it's not always common + + align:start position:0% +lot of sharing it's not always common + + + align:start position:0% +lot of sharing it's not always common +that everybody gets their own plate like + + align:start position:0% +that everybody gets their own plate like + + + align:start position:0% +that everybody gets their own plate like +we do a group goes out they've had their + + align:start position:0% +we do a group goes out they've had their + + + align:start position:0% +we do a group goes out they've had their +main meal in the daytime + + align:start position:0% +main meal in the daytime + + + align:start position:0% +main meal in the daytime +so the nighttime is kind of on less food + + align:start position:0% +so the nighttime is kind of on less food + + + align:start position:0% +so the nighttime is kind of on less food +and they share so the portions are + + align:start position:0% +and they share so the portions are + + + align:start position:0% +and they share so the portions are +smaller + + align:start position:0% +smaller + + + align:start position:0% +smaller +they have smaller plates + + align:start position:0% +they have smaller plates + + + align:start position:0% +they have smaller plates +they have their main uh meal in the + + align:start position:0% +they have their main uh meal in the + + + align:start position:0% +they have their main uh meal in the +middle of the day and there's always a + + align:start position:0% +middle of the day and there's always a + + + align:start position:0% +middle of the day and there's always a +nap + + align:start position:0% +nap + + + align:start position:0% +nap +which is my favorite part + + align:start position:0% +which is my favorite part + + + align:start position:0% +which is my favorite part +and there's also lots of walking this is + + align:start position:0% +and there's also lots of walking this is + + + align:start position:0% +and there's also lots of walking this is +another thing i notice people are + + align:start position:0% +another thing i notice people are + + + align:start position:0% +another thing i notice people are +walking like in most european cities or + + align:start position:0% +walking like in most european cities or + + + align:start position:0% +walking like in most european cities or +any big city lots of walking + + align:start position:0% +any big city lots of walking + + + align:start position:0% +any big city lots of walking +okay so i'm going to show you some + + align:start position:0% +okay so i'm going to show you some + + + align:start position:0% +okay so i'm going to show you some +common food patterns of greece + + align:start position:0% +common food patterns of greece + + + align:start position:0% +common food patterns of greece +real food there's no convenience process + + align:start position:0% +real food there's no convenience process + + + align:start position:0% +real food there's no convenience process +thing garlic in a jar and cheetos in a + + align:start position:0% +thing garlic in a jar and cheetos in a + + + align:start position:0% +thing garlic in a jar and cheetos in a +bag and frozen dinner not common at all + + align:start position:0% +bag and frozen dinner not common at all + + + align:start position:0% +bag and frozen dinner not common at all +no snack foods like bars we're obsessed + + align:start position:0% +no snack foods like bars we're obsessed + + + align:start position:0% +no snack foods like bars we're obsessed +with + + align:start position:0% +with + + + align:start position:0% +with +this doesn't exist it's fruit it's + + align:start position:0% +this doesn't exist it's fruit it's + + + align:start position:0% +this doesn't exist it's fruit it's +vegetable + + align:start position:0% +vegetable + + + align:start position:0% +vegetable +you know meat cheese done + + align:start position:0% +you know meat cheese done + + + align:start position:0% +you know meat cheese done +but no one knows not good may meals eat + + align:start position:0% +but no one knows not good may meals eat + + + align:start position:0% +but no one knows not good may meals eat +it too i think i said that + + align:start position:0% +it too i think i said that + + + align:start position:0% +it too i think i said that +meat is a much smaller part of the meal + + align:start position:0% +meat is a much smaller part of the meal + + + align:start position:0% +meat is a much smaller part of the meal +if it's present it's a small portion + + align:start position:0% +if it's present it's a small portion + + + align:start position:0% +if it's present it's a small portion +like three four ounces which is like a + + align:start position:0% +like three four ounces which is like a + + + align:start position:0% +like three four ounces which is like a +deck of cards which is what we say + + align:start position:0% +deck of cards which is what we say + + + align:start position:0% +deck of cards which is what we say +should be here in this country + + align:start position:0% +should be here in this country + + + align:start position:0% +should be here in this country +then a lot of one pot meals they have + + align:start position:0% +then a lot of one pot meals they have + + + align:start position:0% +then a lot of one pot meals they have +lots of vegetable dishes and i have + + align:start position:0% +lots of vegetable dishes and i have + + + align:start position:0% +lots of vegetable dishes and i have +pictures to show you that are in olive + + align:start position:0% +pictures to show you that are in olive + + + align:start position:0% +pictures to show you that are in olive +oil and it's the main entree it's not a + + align:start position:0% +oil and it's the main entree it's not a + + + align:start position:0% +oil and it's the main entree it's not a +side dish you will see + + align:start position:0% +side dish you will see + + + align:start position:0% +side dish you will see +i hope it looks good yeah fruit is a dis + + align:start position:0% +i hope it looks good yeah fruit is a dis + + + align:start position:0% +i hope it looks good yeah fruit is a dis +is fruit is the dessert + + align:start position:0% +is fruit is the dessert + + + align:start position:0% +is fruit is the dessert +greeks never have desserts after the + + align:start position:0% +greeks never have desserts after the + + + align:start position:0% +greeks never have desserts after the +meal and i don't know about italians + + align:start position:0% +meal and i don't know about italians + + + align:start position:0% +meal and i don't know about italians +but not every day not every day when + + align:start position:0% +but not every day not every day when + + + align:start position:0% +but not every day not every day when +sunday + + align:start position:0% +sunday + + + align:start position:0% +sunday +okay + + align:start position:0% +okay + + + align:start position:0% +okay +desserts are a special time for greeks + + align:start position:0% +desserts are a special time for greeks + + + align:start position:0% +desserts are a special time for greeks +and they're eating alone like oh i'll + + align:start position:0% +and they're eating alone like oh i'll + + + align:start position:0% +and they're eating alone like oh i'll +have a coffee and a dessert for the + + align:start position:0% +have a coffee and a dessert for the + + + align:start position:0% +have a coffee and a dessert for the +other day + + align:start position:0% +other day + + + align:start position:0% +other day +it's it's an event there's no dessert oh + + align:start position:0% +it's it's an event there's no dessert oh + + + align:start position:0% +it's it's an event there's no dessert oh +like we do here it's all fruit is always + + align:start position:0% +like we do here it's all fruit is always + + + align:start position:0% +like we do here it's all fruit is always +served at the meal so it's not a snack + + align:start position:0% +served at the meal so it's not a snack + + + align:start position:0% +served at the meal so it's not a snack +and it's there + + align:start position:0% +and it's there + + + align:start position:0% +and it's there +and then that's my business about the + + align:start position:0% +and then that's my business about the + + + align:start position:0% +and then that's my business about the +sweets are eaten at a separate time so + + align:start position:0% +sweets are eaten at a separate time so + + + align:start position:0% +sweets are eaten at a separate time so +these are some common foods i don't know + + align:start position:0% +these are some common foods i don't know + + + align:start position:0% +these are some common foods i don't know +if you've ever heard of these who has + + align:start position:0% +if you've ever heard of these who has + + + align:start position:0% +if you've ever heard of these who has +been to whole foods you see giant beans + + align:start position:0% +been to whole foods you see giant beans + + + align:start position:0% +been to whole foods you see giant beans +in the salad bar have you seen those + + align:start position:0% +in the salad bar have you seen those + + + align:start position:0% +in the salad bar have you seen those +okay i have some of those that you're + + align:start position:0% +okay i have some of those that you're + + + align:start position:0% +okay i have some of those that you're +going to see + + align:start position:0% +going to see + + + align:start position:0% +going to see +those are usually cooked in a big oil + + align:start position:0% +those are usually cooked in a big oil + + + align:start position:0% +those are usually cooked in a big oil +dish + + align:start position:0% +dish + + + align:start position:0% +dish +stewed green beans is an is an entree + + align:start position:0% +stewed green beans is an is an entree + + + align:start position:0% +stewed green beans is an is an entree +you eat with a salad + + align:start position:0% +you eat with a salad + + + align:start position:0% +you eat with a salad +a piece of bread you're done + + align:start position:0% +a piece of bread you're done + + + align:start position:0% +a piece of bread you're done +uh bean soup you'll see i have stuff + + align:start position:0% +uh bean soup you'll see i have stuff + + + align:start position:0% +uh bean soup you'll see i have stuff +everybody knows what stuffed grapefruit + + align:start position:0% +everybody knows what stuffed grapefruit + + + align:start position:0% +everybody knows what stuffed grapefruit +is it's a great leaf a big leaf so it's + + align:start position:0% +is it's a great leaf a big leaf so it's + + + align:start position:0% +is it's a great leaf a big leaf so it's +a green leafy vegetable and then you + + align:start position:0% +a green leafy vegetable and then you + + + align:start position:0% +a green leafy vegetable and then you +stop it you take rice with lots of oil + + align:start position:0% +stop it you take rice with lots of oil + + + align:start position:0% +stop it you take rice with lots of oil +fresh spices maybe pine nuts maybe + + align:start position:0% +fresh spices maybe pine nuts maybe + + + align:start position:0% +fresh spices maybe pine nuts maybe +raisins + + align:start position:0% +raisins + + + align:start position:0% +raisins +put it on the leaf you roll the leaf and + + align:start position:0% +put it on the leaf you roll the leaf and + + + align:start position:0% +put it on the leaf you roll the leaf and +then you cook it these are also very + + align:start position:0% +then you cook it these are also very + + + align:start position:0% +then you cook it these are also very +common in grapefruit boiled greens you + + align:start position:0% +common in grapefruit boiled greens you + + + align:start position:0% +common in grapefruit boiled greens you +take beet greens you take not spinach + + align:start position:0% +take beet greens you take not spinach + + + align:start position:0% +take beet greens you take not spinach +you take + + align:start position:0% +you take + + + align:start position:0% +you take +swiss chard you just steam it or boil it + + align:start position:0% +swiss chard you just steam it or boil it + + + align:start position:0% +swiss chard you just steam it or boil it +put oil and lemon on it and that's the + + align:start position:0% +put oil and lemon on it and that's the + + + align:start position:0% +put oil and lemon on it and that's the +vegetables + + align:start position:0% +vegetables + + + align:start position:0% +vegetables +yeah lentil soup and the famous spinach + + align:start position:0% +yeah lentil soup and the famous spinach + + + align:start position:0% +yeah lentil soup and the famous spinach +pie yeah + + align:start position:0% +pie yeah + + + align:start position:0% +pie yeah +here we make it in america that is + + align:start position:0% +here we make it in america that is + + + align:start position:0% +here we make it in america that is +usually with butter in between the filo + + align:start position:0% +usually with butter in between the filo + + + align:start position:0% +usually with butter in between the filo +in grease it's often + + align:start position:0% +in grease it's often + + + align:start position:0% +in grease it's often +olive oil + + align:start position:0% +olive oil + + + align:start position:0% +olive oil +okay these are these are mine + + align:start position:0% + + + + align:start position:0% + +i made those and i had them for dinner + + align:start position:0% +i made those and i had them for dinner + + + align:start position:0% +i made those and i had them for dinner +for lunch actually that's my little dog + + align:start position:0% +for lunch actually that's my little dog + + + align:start position:0% +for lunch actually that's my little dog +dish i didn't have time to make it look + + align:start position:0% +dish i didn't have time to make it look + + + align:start position:0% +dish i didn't have time to make it look +good but those are those giant beans + + align:start position:0% +good but those are those giant beans + + + align:start position:0% +good but those are those giant beans +and this is spinach carrots garlic + + align:start position:0% +and this is spinach carrots garlic + + + align:start position:0% +and this is spinach carrots garlic +they're huge yeah + + align:start position:0% +they're huge yeah + + + align:start position:0% +they're huge yeah +yeah they're like giant lima beans in a + + align:start position:0% +yeah they're like giant lima beans in a + + + align:start position:0% +yeah they're like giant lima beans in a +tomato and there's oil there if this was + + align:start position:0% +tomato and there's oil there if this was + + + align:start position:0% +tomato and there's oil there if this was +a if this was a more greek greek dish + + align:start position:0% +a if this was a more greek greek dish + + + align:start position:0% +a if this was a more greek greek dish +you would see the oil seeping out and i + + align:start position:0% +you would see the oil seeping out and i + + + align:start position:0% +you would see the oil seeping out and i +try and make it look calorie because + + align:start position:0% +try and make it look calorie because + + + align:start position:0% +try and make it look calorie because +you know i gotta worry about those + + align:start position:0% +you know i gotta worry about those + + + align:start position:0% +you know i gotta worry about those +things and then these i got this from + + align:start position:0% +things and then these i got this from + + + align:start position:0% +things and then these i got this from +the internet i thought that was a good + + align:start position:0% +the internet i thought that was a good + + + align:start position:0% +the internet i thought that was a good +picture these are those string beans + + align:start position:0% +picture these are those string beans + + + align:start position:0% +picture these are those string beans +this is a main dish it's not a side + + align:start position:0% +this is a main dish it's not a side + + + align:start position:0% +this is a main dish it's not a side +again it's oil tomato onion garlic + + align:start position:0% +again it's oil tomato onion garlic + + + align:start position:0% +again it's oil tomato onion garlic +this doesn't have a lot of oil but the + + align:start position:0% +this doesn't have a lot of oil but the + + + align:start position:0% +this doesn't have a lot of oil but the +next photo is my mother-in-law's who + + align:start position:0% +next photo is my mother-in-law's who + + + align:start position:0% +next photo is my mother-in-law's who +lives in greece and you can see big + + align:start position:0% +lives in greece and you can see big + + + align:start position:0% +lives in greece and you can see big +difference you see there's a lot of oil + + align:start position:0% +difference you see there's a lot of oil + + + align:start position:0% +difference you see there's a lot of oil +out there + + align:start position:0% +out there + + + align:start position:0% +out there +lots and she used to put more + + align:start position:0% +lots and she used to put more + + + align:start position:0% +lots and she used to put more +that was how don't forget oil and fat at + + align:start position:0% +that was how don't forget oil and fat at + + + align:start position:0% +that was how don't forget oil and fat at +a meal keeps us full + + align:start position:0% +a meal keeps us full + + + align:start position:0% +a meal keeps us full +fat when you when you have a no fat day + + align:start position:0% +fat when you when you have a no fat day + + + align:start position:0% +fat when you when you have a no fat day +no fat food you're going to be hungry + + align:start position:0% +no fat food you're going to be hungry + + + align:start position:0% +no fat food you're going to be hungry +and you're going to want to overeat + + align:start position:0% +and you're going to want to overeat + + + align:start position:0% +and you're going to want to overeat +usually carbohydrates + + align:start position:0% +usually carbohydrates + + + align:start position:0% +usually carbohydrates +yeah so these are stuffed grape leaves + + align:start position:0% +yeah so these are stuffed grape leaves + + + align:start position:0% +yeah so these are stuffed grape leaves +and squash blossoms + + align:start position:0% +and squash blossoms + + + align:start position:0% +and squash blossoms +so again i call this like real + + align:start position:0% +so again i call this like real + + + align:start position:0% +so again i call this like real +vegetarian food not isolated soy protein + + align:start position:0% +vegetarian food not isolated soy protein + + + align:start position:0% +vegetarian food not isolated soy protein +here's a greek salad a real greek salad + + align:start position:0% +here's a greek salad a real greek salad + + + align:start position:0% +here's a greek salad a real greek salad +what's different about this + + align:start position:0% +what's different about this + + + align:start position:0% +what's different about this +yes there's no lettuce + + align:start position:0% +yes there's no lettuce + + + align:start position:0% +yes there's no lettuce +anything else + + align:start position:0% +anything else + + + align:start position:0% +anything else +there's not half a pound of feta cheese + + align:start position:0% +there's not half a pound of feta cheese + + + align:start position:0% +there's not half a pound of feta cheese +on here + + align:start position:0% +on here + + + align:start position:0% +on here +and that creamy greek dressing which is + + align:start position:0% +and that creamy greek dressing which is + + + align:start position:0% +and that creamy greek dressing which is +not great + + align:start position:0% + + + + align:start position:0% + +just tomato + + align:start position:0% + + + + align:start position:0% + +which is divine i love it + + align:start position:0% + + + + align:start position:0% + +okay so now i have my famous tips of how + + align:start position:0% +okay so now i have my famous tips of how + + + align:start position:0% +okay so now i have my famous tips of how +you're gonna get a mediterranean diet + + align:start position:0% +you're gonna get a mediterranean diet + + + align:start position:0% +you're gonna get a mediterranean diet +here in america and by the way there was + + align:start position:0% +here in america and by the way there was + + + align:start position:0% +here in america and by the way there was +a study i didn't put in here but it was + + align:start position:0% +a study i didn't put in here but it was + + + align:start position:0% +a study i didn't put in here but it was +talking about how + + align:start position:0% +talking about how + + + align:start position:0% +talking about how +transporting can you transport the + + align:start position:0% +transporting can you transport the + + + align:start position:0% +transporting can you transport the +mediterranean diet to other countries + + align:start position:0% +mediterranean diet to other countries + + + align:start position:0% +mediterranean diet to other countries +like australia and america and the study + + align:start position:0% +like australia and america and the study + + + align:start position:0% +like australia and america and the study +said yes you can so there's hope for us + + align:start position:0% +said yes you can so there's hope for us + + + align:start position:0% +said yes you can so there's hope for us +okay so you're gonna do it cook and eat + + align:start position:0% +okay so you're gonna do it cook and eat + + + align:start position:0% +okay so you're gonna do it cook and eat +home more often because you know what + + align:start position:0% +home more often because you know what + + + align:start position:0% +home more often because you know what +you're doing you have a chance to eat + + align:start position:0% +you're doing you have a chance to eat + + + align:start position:0% +you're doing you have a chance to eat +healthier eating out all the time is not + + align:start position:0% +healthier eating out all the time is not + + + align:start position:0% +healthier eating out all the time is not +a healthy activity + + align:start position:0% +a healthy activity + + + align:start position:0% +a healthy activity +okay so in your cooking eat vegetarian + + align:start position:0% +okay so in your cooking eat vegetarian + + + align:start position:0% +okay so in your cooking eat vegetarian +one or two times a week as much as you + + align:start position:0% +one or two times a week as much as you + + + align:start position:0% +one or two times a week as much as you +want most people who are not vegetarians + + align:start position:0% +want most people who are not vegetarians + + + align:start position:0% +want most people who are not vegetarians +never have just a vegan meal that + + align:start position:0% +never have just a vegan meal that + + + align:start position:0% +never have just a vegan meal that +doesn't have this + + align:start position:0% +doesn't have this + + + align:start position:0% +doesn't have this +which is not the healthiest thing all + + align:start position:0% +which is not the healthiest thing all + + + align:start position:0% +which is not the healthiest thing all +those tofu + + align:start position:0% +those tofu + + + align:start position:0% +those tofu +i mean tofu by itself is much healthier + + align:start position:0% +i mean tofu by itself is much healthier + + + align:start position:0% +i mean tofu by itself is much healthier +than the isolated soy protein burgers + + align:start position:0% +than the isolated soy protein burgers + + + align:start position:0% +than the isolated soy protein burgers +and tofu dogs and + + align:start position:0% +and tofu dogs and + + + align:start position:0% +and tofu dogs and +all of that so so that's one way for you + + align:start position:0% +all of that so so that's one way for you + + + align:start position:0% +all of that so so that's one way for you +to get a mediterranean diet is try a + + align:start position:0% +to get a mediterranean diet is try a + + + align:start position:0% +to get a mediterranean diet is try a +more mediterranean vegetarian + + align:start position:0% +more mediterranean vegetarian + + + align:start position:0% +more mediterranean vegetarian +meal + + align:start position:0% +meal + + + align:start position:0% +meal +um okay so some of those are i didn't + + align:start position:0% +um okay so some of those are i didn't + + + align:start position:0% +um okay so some of those are i didn't +have pictures of falafel or hummus but + + align:start position:0% +have pictures of falafel or hummus but + + + align:start position:0% +have pictures of falafel or hummus but +those are also mediterranean very + + align:start position:0% +those are also mediterranean very + + + align:start position:0% +those are also mediterranean very +healthy dishes chickpeas tahini again + + align:start position:0% +healthy dishes chickpeas tahini again + + + align:start position:0% +healthy dishes chickpeas tahini again +the same + + align:start position:0% +the same + + + align:start position:0% +the same +yeah + + align:start position:0% +yeah + + + align:start position:0% +yeah +sesame seeds yeah good fats + + align:start position:0% +sesame seeds yeah good fats + + + align:start position:0% +sesame seeds yeah good fats +yeah uh use extra virgin olive oil for + + align:start position:0% +yeah uh use extra virgin olive oil for + + + align:start position:0% +yeah uh use extra virgin olive oil for +cooking salad for your cooking add that + + align:start position:0% +cooking salad for your cooking add that + + + align:start position:0% +cooking salad for your cooking add that +to salads don't use salad dressing which + + align:start position:0% +to salads don't use salad dressing which + + + align:start position:0% +to salads don't use salad dressing which +i think is my next tip because you don't + + align:start position:0% +i think is my next tip because you don't + + + align:start position:0% +i think is my next tip because you don't +get a good oil in a salad dressing and + + align:start position:0% +get a good oil in a salad dressing and + + + align:start position:0% +get a good oil in a salad dressing and +you get sugar and you get thickener and + + align:start position:0% +you get sugar and you get thickener and + + + align:start position:0% +you get sugar and you get thickener and +you get + + align:start position:0% +you get + + + align:start position:0% +you get +tons of salt and you get sugar and + + align:start position:0% +tons of salt and you get sugar and + + + align:start position:0% +tons of salt and you get sugar and +if you can get yourself a good olive oil + + align:start position:0% +if you can get yourself a good olive oil + + + align:start position:0% +if you can get yourself a good olive oil +put your own oil and vinegar or lemon + + align:start position:0% +put your own oil and vinegar or lemon + + + align:start position:0% +put your own oil and vinegar or lemon +you'll be healthier and you'll be + + align:start position:0% +you'll be healthier and you'll be + + + align:start position:0% +you'll be healthier and you'll be +getting + + align:start position:0% +getting + + + align:start position:0% +getting +the flavonoids and all those wonderful + + align:start position:0% +the flavonoids and all those wonderful + + + align:start position:0% +the flavonoids and all those wonderful +ingredients + + align:start position:0% +ingredients + + + align:start position:0% +ingredients +and it tastes better at first you you + + align:start position:0% +and it tastes better at first you you + + + align:start position:0% +and it tastes better at first you you +might not if you're used to salad + + align:start position:0% +might not if you're used to salad + + + align:start position:0% +might not if you're used to salad +dressing when i was growing up we had + + align:start position:0% +dressing when i was growing up we had + + + align:start position:0% +dressing when i was growing up we had +salad dressing that was what we had and + + align:start position:0% +salad dressing that was what we had and + + + align:start position:0% +salad dressing that was what we had and +we loved it my brother and i we shunned + + align:start position:0% +we loved it my brother and i we shunned + + + align:start position:0% +we loved it my brother and i we shunned +the olive oil and said well it's motor + + align:start position:0% +the olive oil and said well it's motor + + + align:start position:0% +the olive oil and said well it's motor +oil oh we didn't like it + + align:start position:0% +oil oh we didn't like it + + + align:start position:0% +oil oh we didn't like it +because this italian dressing was so + + align:start position:0% +because this italian dressing was so + + + align:start position:0% +because this italian dressing was so +sweet and + + align:start position:0% +sweet and + + + align:start position:0% +sweet and +sugar and spicy it's not 380 but it's + + align:start position:0% +sugar and spicy it's not 380 but it's + + + align:start position:0% +sugar and spicy it's not 380 but it's +not it's + + align:start position:0% +not it's + + + align:start position:0% +not it's +just like the greek dressing is not + + align:start position:0% +just like the greek dressing is not + + + align:start position:0% +just like the greek dressing is not +there's no dressing in greece it's just + + align:start position:0% +there's no dressing in greece it's just + + + align:start position:0% +there's no dressing in greece it's just +same yeah it's the same yeah and it's + + align:start position:0% +same yeah it's the same yeah and it's + + + align:start position:0% +same yeah it's the same yeah and it's +healthier + + align:start position:0% +healthier + + + align:start position:0% +healthier +so that's one way you can do it yes so i + + align:start position:0% +so that's one way you can do it yes so i + + + align:start position:0% +so that's one way you can do it yes so i +think i've really heard the support but + + align:start position:0% +think i've really heard the support but + + + align:start position:0% +think i've really heard the support but +what's the difference between the + + align:start position:0% +what's the difference between the + + + align:start position:0% +what's the difference between the +extroversion the version the mod version + + align:start position:0% +extroversion the version the mod version + + + align:start position:0% +extroversion the version the mod version +so + + align:start position:0% +so + + + align:start position:0% +so +oh good it's written there yeah extra + + align:start position:0% +oh good it's written there yeah extra + + + align:start position:0% +oh good it's written there yeah extra +virgin would be the first pressing + + align:start position:0% +virgin would be the first pressing + + + align:start position:0% +virgin would be the first pressing +and it would not be + + align:start position:0% +and it would not be + + + align:start position:0% +and it would not be +over acidic and over like have foul + + align:start position:0% +over acidic and over like have foul + + + align:start position:0% +over acidic and over like have foul +tasting + + align:start position:0% +tasting + + + align:start position:0% +tasting +foul flavors in it so it has to do with + + align:start position:0% +foul flavors in it so it has to do with + + + align:start position:0% +foul flavors in it so it has to do with +the quality and like the first pressing + + align:start position:0% +the quality and like the first pressing + + + align:start position:0% +the quality and like the first pressing +as opposed to because you can + + align:start position:0% +as opposed to because you can + + + align:start position:0% +as opposed to because you can +keep pressing this you know get the + + align:start position:0% +keep pressing this you know get the + + + align:start position:0% +keep pressing this you know get the +first extraction then keep pressing and + + align:start position:0% +first extraction then keep pressing and + + + align:start position:0% +first extraction then keep pressing and +then you get not so good olive oil and + + align:start position:0% +then you get not so good olive oil and + + + align:start position:0% +then you get not so good olive oil and +then you can have it mixed there was a + + align:start position:0% +then you can have it mixed there was a + + + align:start position:0% +then you can have it mixed there was a +big scandal i was telling you about that + + align:start position:0% +big scandal i was telling you about that + + + align:start position:0% +big scandal i was telling you about that +in a book i read big scandal with olive + + align:start position:0% +in a book i read big scandal with olive + + + align:start position:0% +in a book i read big scandal with olive +oil + + align:start position:0% +oil + + + align:start position:0% +oil +they mix soya oil in it because it's + + align:start position:0% +they mix soya oil in it because it's + + + align:start position:0% +they mix soya oil in it because it's +very profitable et cetera et cetera so + + align:start position:0% +very profitable et cetera et cetera so + + + align:start position:0% +very profitable et cetera et cetera so +that's the question yeah if it says pure + + align:start position:0% +that's the question yeah if it says pure + + + align:start position:0% +that's the question yeah if it says pure +or if it says blended i wouldn't buy it + + align:start position:0% +or if it says blended i wouldn't buy it + + + align:start position:0% +or if it says blended i wouldn't buy it +because they do sometimes they think + + align:start position:0% +because they do sometimes they think + + + align:start position:0% +because they do sometimes they think +that's cute it's not bad pure is not + + align:start position:0% +that's cute it's not bad pure is not + + + align:start position:0% +that's cute it's not bad pure is not +good pure is like the one of the last + + align:start position:0% +good pure is like the one of the last + + + align:start position:0% +good pure is like the one of the last +qualities + + align:start position:0% +qualities + + + align:start position:0% +qualities +correct + + align:start position:0% +correct + + + align:start position:0% +correct +pure is inferior to extra + + align:start position:0% +pure is inferior to extra + + + align:start position:0% +pure is inferior to extra +so it's the first pressing the extra + + align:start position:0% +so it's the first pressing the extra + + + align:start position:0% +so it's the first pressing the extra +version is the best + + align:start position:0% +version is the best + + + align:start position:0% +version is the best +and it's it's more expensive but um it's + + align:start position:0% +and it's it's more expensive but um it's + + + align:start position:0% +and it's it's more expensive but um it's +also the most it should be the most + + align:start position:0% +also the most it should be the most + + + align:start position:0% +also the most it should be the most +healthy one + + align:start position:0% +healthy one + + + align:start position:0% +healthy one +the other ones are not as healthy as + + align:start position:0% +the other ones are not as healthy as + + + align:start position:0% +the other ones are not as healthy as +this one so this is yeah + + align:start position:0% +this one so this is yeah + + + align:start position:0% +this one so this is yeah +so another way you can do is steam your + + align:start position:0% +so another way you can do is steam your + + + align:start position:0% +so another way you can do is steam your +leafy green vegetables branch out get + + align:start position:0% +leafy green vegetables branch out get + + + align:start position:0% +leafy green vegetables branch out get +some escarole + + align:start position:0% +some escarole + + + align:start position:0% +some escarole +you put it in your soups you can i boil + + align:start position:0% +you put it in your soups you can i boil + + + align:start position:0% +you put it in your soups you can i boil +mine boil i steam it and i put oil and + + align:start position:0% +mine boil i steam it and i put oil and + + + align:start position:0% +mine boil i steam it and i put oil and +lemon that's my side with a piece of + + align:start position:0% +lemon that's my side with a piece of + + + align:start position:0% +lemon that's my side with a piece of +chicken and i might have something else + + align:start position:0% +chicken and i might have something else + + + align:start position:0% +chicken and i might have something else +with it and that's my meal otherwise i + + align:start position:0% +with it and that's my meal otherwise i + + + align:start position:0% +with it and that's my meal otherwise i +don't get lippy green vegetables but + + align:start position:0% +don't get lippy green vegetables but + + + align:start position:0% +don't get lippy green vegetables but +this way is easy + + align:start position:0% +this way is easy + + + align:start position:0% +this way is easy +you also can then + + align:start position:0% +you also can then + + + align:start position:0% +you also can then +put lots of garlic and lots of oil in + + align:start position:0% +put lots of garlic and lots of oil in + + + align:start position:0% +put lots of garlic and lots of oil in +the frying pan and cook it that way + + align:start position:0% +the frying pan and cook it that way + + + align:start position:0% +the frying pan and cook it that way +you could do that too make your own + + align:start position:0% +you could do that too make your own + + + align:start position:0% +you could do that too make your own +salad dressing with real + + align:start position:0% +salad dressing with real + + + align:start position:0% +salad dressing with real +extra virgin olive oil so you don't use + + align:start position:0% +extra virgin olive oil so you don't use + + + align:start position:0% +extra virgin olive oil so you don't use +salad dressings because there's nothing + + align:start position:0% +salad dressings because there's nothing + + + align:start position:0% +salad dressings because there's nothing +healthy about the salad dressings we buy + + align:start position:0% +healthy about the salad dressings we buy + + + align:start position:0% +healthy about the salad dressings we buy +nothing they're wicked salty look at + + align:start position:0% +nothing they're wicked salty look at + + + align:start position:0% +nothing they're wicked salty look at +sugar + + align:start position:0% +sugar + + + align:start position:0% +sugar +reduce your intake of desserts put some + + align:start position:0% +reduce your intake of desserts put some + + + align:start position:0% +reduce your intake of desserts put some +parameters you know um around desserts + + align:start position:0% +parameters you know um around desserts + + + align:start position:0% +parameters you know um around desserts +so that you have it maybe on the weekend + + align:start position:0% +so that you have it maybe on the weekend + + + align:start position:0% +so that you have it maybe on the weekend +you have it twice a week you don't have + + align:start position:0% +you have it twice a week you don't have + + + align:start position:0% +you have it twice a week you don't have +cookies every single day or just because + + align:start position:0% +cookies every single day or just because + + + align:start position:0% +cookies every single day or just because +it's thursday night at nine o'clock i'm + + align:start position:0% +it's thursday night at nine o'clock i'm + + + align:start position:0% +it's thursday night at nine o'clock i'm +having cookies in front of the tv + + align:start position:0% +having cookies in front of the tv + + + align:start position:0% +having cookies in front of the tv +that's another thing we as americans + + align:start position:0% +that's another thing we as americans + + + align:start position:0% +that's another thing we as americans +struggle with that we want sweets all + + align:start position:0% +struggle with that we want sweets all + + + align:start position:0% +struggle with that we want sweets all +the time for no reason i think in these + + align:start position:0% +the time for no reason i think in these + + + align:start position:0% +the time for no reason i think in these +cultures it's used more for a + + align:start position:0% +cultures it's used more for a + + + align:start position:0% +cultures it's used more for a +celebration oh it's a holiday it's a + + align:start position:0% +celebration oh it's a holiday it's a + + + align:start position:0% +celebration oh it's a holiday it's a +special time it isn't just three o'clock + + align:start position:0% +special time it isn't just three o'clock + + + align:start position:0% +special time it isn't just three o'clock +on tuesday and i'll have a huge + + align:start position:0% +on tuesday and i'll have a huge + + + align:start position:0% +on tuesday and i'll have a huge +rebecca's cookie like this + + align:start position:0% +rebecca's cookie like this + + + align:start position:0% +rebecca's cookie like this +that's like a 600 calorie investment + + align:start position:0% +that's like a 600 calorie investment + + + align:start position:0% +that's like a 600 calorie investment +there with butter cookies are made with + + align:start position:0% +there with butter cookies are made with + + + align:start position:0% +there with butter cookies are made with +butter um here another way eat plain + + align:start position:0% +butter um here another way eat plain + + + align:start position:0% +butter um here another way eat plain +yogurt yolk and put your own fruit + + align:start position:0% +yogurt yolk and put your own fruit + + + align:start position:0% +yogurt yolk and put your own fruit +and maybe a drizzle the plain there's + + align:start position:0% +and maybe a drizzle the plain there's + + + align:start position:0% +and maybe a drizzle the plain there's +another classic greek food greek night + + align:start position:0% +another classic greek food greek night + + + align:start position:0% +another classic greek food greek night +honey + + align:start position:0% +honey + + + align:start position:0% +honey +nuts could go here too as opposed to + + align:start position:0% +nuts could go here too as opposed to + + + align:start position:0% +nuts could go here too as opposed to +those yogurts that have a lot of sugar + + align:start position:0% +those yogurts that have a lot of sugar + + + align:start position:0% +those yogurts that have a lot of sugar +added to them we like sweet foods here + + align:start position:0% +added to them we like sweet foods here + + + align:start position:0% +added to them we like sweet foods here +yes okay um have meat be a small part of + + align:start position:0% +yes okay um have meat be a small part of + + + align:start position:0% +yes okay um have meat be a small part of +the meal fine we said that + + align:start position:0% +the meal fine we said that + + + align:start position:0% +the meal fine we said that +eat fish with small bones enjoy smell + + align:start position:0% +eat fish with small bones enjoy smell + + + align:start position:0% +eat fish with small bones enjoy smell +sardines necklace on packaged foods + + align:start position:0% +sardines necklace on packaged foods + + + align:start position:0% +sardines necklace on packaged foods +boxed foods have this instead and then i + + align:start position:0% +boxed foods have this instead and then i + + + align:start position:0% +boxed foods have this instead and then i +think that's it i have one slide that + + align:start position:0% +think that's it i have one slide that + + + align:start position:0% +think that's it i have one slide that +says i'm gonna challenge you all what + + align:start position:0% +says i'm gonna challenge you all what + + + align:start position:0% +says i'm gonna challenge you all what +can you do now so after tonight after + + align:start position:0% +can you do now so after tonight after + + + align:start position:0% +can you do now so after tonight after +you listen to me and you know your diets + + align:start position:0% +you listen to me and you know your diets + + + align:start position:0% +you listen to me and you know your diets +what can you do now + + align:start position:0% +what can you do now + + + align:start position:0% +what can you do now +think of one item that you'd like to + + align:start position:0% +think of one item that you'd like to + + + align:start position:0% +think of one item that you'd like to +change about your diet + + align:start position:0% +change about your diet + + + align:start position:0% +change about your diet +that would lead you closer to a + + align:start position:0% +that would lead you closer to a + + + align:start position:0% +that would lead you closer to a +mediterranean diet you're not going to + + align:start position:0% +mediterranean diet you're not going to + + + align:start position:0% +mediterranean diet you're not going to +revamp your diet in a night but maybe + + align:start position:0% +revamp your diet in a night but maybe + + + align:start position:0% +revamp your diet in a night but maybe +you could do one thing + + align:start position:0% +you could do one thing + + + align:start position:0% +you could do one thing +you could try a little bit closer + + align:start position:0% +you could try a little bit closer + + + align:start position:0% +you could try a little bit closer +so that's it + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/eXf2Zak-s0o.txt b/eXf2Zak-s0o.txt new file mode 100644 index 0000000000000000000000000000000000000000..d8d3f65eb23f8bb355d3e371efd8a23af41ac5b9 --- /dev/null +++ b/eXf2Zak-s0o.txt @@ -0,0 +1,195 @@ +align:start position:0% + +in this lecture we start our discussion + + align:start position:0% +in this lecture we start our discussion + + + align:start position:0% +in this lecture we start our discussion +of continuous random variables we will + + align:start position:0% +of continuous random variables we will + + + align:start position:0% +of continuous random variables we will +focus on the case of a single continuous + + align:start position:0% +focus on the case of a single continuous + + + align:start position:0% +focus on the case of a single continuous +random variable and will describe its + + align:start position:0% +random variable and will describe its + + + align:start position:0% +random variable and will describe its +distribution using a so called + + align:start position:0% +distribution using a so called + + + align:start position:0% +distribution using a so called +probability density function an object + + align:start position:0% +probability density function an object + + + align:start position:0% +probability density function an object +that will replace the PMF s from the + + align:start position:0% +that will replace the PMF s from the + + + align:start position:0% +that will replace the PMF s from the +discrete case we will then proceed to + + align:start position:0% +discrete case we will then proceed to + + + align:start position:0% +discrete case we will then proceed to +define the expectation and the variance + + align:start position:0% +define the expectation and the variance + + + align:start position:0% +define the expectation and the variance +of a continuous random variable and will + + align:start position:0% +of a continuous random variable and will + + + align:start position:0% +of a continuous random variable and will +see that their basic properties remain + + align:start position:0% +see that their basic properties remain + + + align:start position:0% +see that their basic properties remain +unchanged there will be one new concept + + align:start position:0% +unchanged there will be one new concept + + + align:start position:0% +unchanged there will be one new concept +the cumulative distribution function + + align:start position:0% +the cumulative distribution function + + + align:start position:0% +the cumulative distribution function +which will allow us to describe in a + + align:start position:0% +which will allow us to describe in a + + + align:start position:0% +which will allow us to describe in a +unified manner both discrete and + + align:start position:0% +unified manner both discrete and + + + align:start position:0% +unified manner both discrete and +continuous random variables even + + align:start position:0% +continuous random variables even + + + align:start position:0% +continuous random variables even +so-called mixed random variables that + + align:start position:0% +so-called mixed random variables that + + + align:start position:0% +so-called mixed random variables that +have both a discrete and the continuous + + align:start position:0% +have both a discrete and the continuous + + + align:start position:0% +have both a discrete and the continuous +component in the course of this lecture + + align:start position:0% +component in the course of this lecture + + + align:start position:0% +component in the course of this lecture +we will also introduce some of the most + + align:start position:0% +we will also introduce some of the most + + + align:start position:0% +we will also introduce some of the most +common continuous random variables + + align:start position:0% +common continuous random variables + + + align:start position:0% +common continuous random variables +uniform exponential and normal we will + + align:start position:0% +uniform exponential and normal we will + + + align:start position:0% +uniform exponential and normal we will +pay special attention to the normal + + align:start position:0% +pay special attention to the normal + + + align:start position:0% +pay special attention to the normal +distribution and the ways that we can + + align:start position:0% +distribution and the ways that we can + + + align:start position:0% +distribution and the ways that we can +calculate the Associated probabilities \ No newline at end of file diff --git a/fK9AGvLf3yw.txt b/fK9AGvLf3yw.txt new file mode 100644 index 0000000000000000000000000000000000000000..7c1473ac6908c7e3d6ce919913c804367aeaa782 --- /dev/null +++ b/fK9AGvLf3yw.txt @@ -0,0 +1,12688 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so we'll start with we'll + + align:start position:0% +ocw.mit.edu so we'll start with we'll + + + align:start position:0% +ocw.mit.edu so we'll start with we'll +start quickly going over the concept + + align:start position:0% +start quickly going over the concept + + + align:start position:0% +start quickly going over the concept +questions for the homework this + + align:start position:0% +questions for the homework this + + + align:start position:0% +questions for the homework this +week so you have a + + align:start position:0% + + + + align:start position:0% + +two rotor + + align:start position:0% + + + + align:start position:0% + +system it says if you give it a + + align:start position:0% +system it says if you give it a + + + align:start position:0% +system it says if you give it a +deflection exactly the mode shape of + + align:start position:0% +deflection exactly the mode shape of + + + align:start position:0% +deflection exactly the mode shape of +mode + + align:start position:0% +mode + + + align:start position:0% +mode +two what frequency components do you + + align:start position:0% +two what frequency components do you + + + align:start position:0% +two what frequency components do you +expect the transient response to + + align:start position:0% +expect the transient response to + + + align:start position:0% +expect the transient response to +have so some people most people said + + align:start position:0% +have so some people most people said + + + align:start position:0% +have so some people most people said +only Omega 2 but quite a few people said + + align:start position:0% +only Omega 2 but quite a few people said + + + align:start position:0% +only Omega 2 but quite a few people said +both so + + align:start position:0% + + + + align:start position:0% + +this introduction to vibration that we + + align:start position:0% +this introduction to vibration that we + + + align:start position:0% +this introduction to vibration that we +have been doing for the last few + + align:start position:0% +have been doing for the last few + + + align:start position:0% +have been doing for the last few +lectures my goal in it is to have you + + align:start position:0% +lectures my goal in it is to have you + + + align:start position:0% +lectures my goal in it is to have you +folks go away with a pretty good + + align:start position:0% +folks go away with a pretty good + + + align:start position:0% +folks go away with a pretty good +conceptual understanding of the basics + + align:start position:0% +conceptual understanding of the basics + + + align:start position:0% +conceptual understanding of the basics +of vibration and on the the final exam + + align:start position:0% +of vibration and on the the final exam + + + align:start position:0% +of vibration and on the the final exam +I'm not going to have you derive + + align:start position:0% +I'm not going to have you derive + + + align:start position:0% +I'm not going to have you derive +anything you know + + align:start position:0% +anything you know + + + align:start position:0% +anything you know +like finding the natural frequencies of + + align:start position:0% +like finding the natural frequencies of + + + align:start position:0% +like finding the natural frequencies of +a 3X 3 degree Freedom system you know + + align:start position:0% +a 3X 3 degree Freedom system you know + + + align:start position:0% +a 3X 3 degree Freedom system you know +solving a sixth order system in Omega + + align:start position:0% +solving a sixth order system in Omega + + + align:start position:0% +solving a sixth order system in Omega +squar but I won't do that kind of thing + + align:start position:0% +squar but I won't do that kind of thing + + + align:start position:0% +squar but I won't do that kind of thing +to you but questions like this are + + align:start position:0% +to you but questions like this are + + + align:start position:0% +to you but questions like this are +really fair game so if uh we did this + + align:start position:0% +really fair game so if uh we did this + + + align:start position:0% +really fair game so if uh we did this +business by modal analysis and we did an + + align:start position:0% +business by modal analysis and we did an + + + align:start position:0% +business by modal analysis and we did an +example the other day where you where + + align:start position:0% +example the other day where you where + + + align:start position:0% +example the other day where you where +with the system we had here if you + + align:start position:0% +with the system we had here if you + + + align:start position:0% +with the system we had here if you +deflect it in exactly the shape of one + + align:start position:0% +deflect it in exactly the shape of one + + + align:start position:0% +deflect it in exactly the shape of one +mode what kind of response do you + + align:start position:0% + + + + align:start position:0% + +get initial conditions that are shaped + + align:start position:0% +get initial conditions that are shaped + + + align:start position:0% +get initial conditions that are shaped +exactly like one of the mode + + align:start position:0% +exactly like one of the mode + + + align:start position:0% +exactly like one of the mode +shapes it has exactly that + + align:start position:0% +shapes it has exactly that + + + align:start position:0% +shapes it has exactly that +natural frequency well not only have + + align:start position:0% +natural frequency well not only have + + + align:start position:0% +natural frequency well not only have +only that natural frequency in it but + + align:start position:0% +only that natural frequency in it but + + + align:start position:0% +only that natural frequency in it but +the if you deflect it initially in the + + align:start position:0% +the if you deflect it initially in the + + + align:start position:0% +the if you deflect it initially in the +mode shape what will the responding + + align:start position:0% +mode shape what will the responding + + + align:start position:0% +mode shape what will the responding +motion look like just like the mode + + align:start position:0% +motion look like just like the mode + + + align:start position:0% +motion look like just like the mode +shape just like the mode shape and if + + align:start position:0% +shape just like the mode shape and if + + + align:start position:0% +shape just like the mode shape and if +the motion is in a particular mode shape + + align:start position:0% +the motion is in a particular mode shape + + + align:start position:0% +the motion is in a particular mode shape +it will be at this is Transit vibration + + align:start position:0% +it will be at this is Transit vibration + + + align:start position:0% +it will be at this is Transit vibration +no external Force you deflect it and let + + align:start position:0% +no external Force you deflect it and let + + + align:start position:0% +no external Force you deflect it and let +it go you will see only Motion in that + + align:start position:0% +it go you will see only Motion in that + + + align:start position:0% +it go you will see only Motion in that +mode if it's if you give it an initial + + align:start position:0% +mode if it's if you give it an initial + + + align:start position:0% +mode if it's if you give it an initial +deflections exactly in that mode shape + + align:start position:0% +deflections exactly in that mode shape + + + align:start position:0% +deflections exactly in that mode shape +if you did if you went to the other mode + + align:start position:0% +if you did if you went to the other mode + + + align:start position:0% +if you did if you went to the other mode +and deflected it that way and let go it + + align:start position:0% +and deflected it that way and let go it + + + align:start position:0% +and deflected it that way and let go it +would change frequency and would vibrate + + align:start position:0% +would change frequency and would vibrate + + + align:start position:0% +would change frequency and would vibrate +only in that shape and anything else in + + align:start position:0% +only in that shape and anything else in + + + align:start position:0% +only in that shape and anything else in +be any other combination of motions is + + align:start position:0% +be any other combination of motions is + + + align:start position:0% +be any other combination of motions is +some linear sum of those two mode shapes + + align:start position:0% +some linear sum of those two mode shapes + + + align:start position:0% +some linear sum of those two mode shapes +any other allowable motion of the system + + align:start position:0% +any other allowable motion of the system + + + align:start position:0% +any other allowable motion of the system +can be made up of some weighted sum of + + align:start position:0% +can be made up of some weighted sum of + + + align:start position:0% +can be made up of some weighted sum of +the two mode shapes right and that's the + + align:start position:0% +the two mode shapes right and that's the + + + align:start position:0% +the two mode shapes right and that's the +amount of each mode that you get is the + + align:start position:0% +amount of each mode that you get is the + + + align:start position:0% +amount of each mode that you get is the +weighted sum what are the the weightings + + align:start position:0% +weighted sum what are the the weightings + + + align:start position:0% +weighted sum what are the the weightings +but the weightings are there one zero + + align:start position:0% +but the weightings are there one zero + + + align:start position:0% +but the weightings are there one zero +then it's all one mode not of another if + + align:start position:0% +then it's all one mode not of another if + + + align:start position:0% +then it's all one mode not of another if +it takes some of each mode to give you + + align:start position:0% +it takes some of each mode to give you + + + align:start position:0% +it takes some of each mode to give you +the initial deflected shape that's how + + align:start position:0% +the initial deflected shape that's how + + + align:start position:0% +the initial deflected shape that's how +much of each mode you get so the answer + + align:start position:0% +much of each mode you get so the answer + + + align:start position:0% +much of each mode you get so the answer +to this question + + align:start position:0% + + + + align:start position:0% + +is only mode two okay + + align:start position:0% + + + + align:start position:0% + +next I forget what you were given online + + align:start position:0% +next I forget what you were given online + + + align:start position:0% +next I forget what you were given online +apply the concept which modor is likely + + align:start position:0% +apply the concept which modor is likely + + + align:start position:0% +apply the concept which modor is likely +to dominate the steady state response + + align:start position:0% +to dominate the steady state response + + + align:start position:0% +to dominate the steady state response +for the exitation of + + align:start position:0% +for the exitation of + + + align:start position:0% +for the exitation of +Part D so it was probably being excited + + align:start position:0% +Part D so it was probably being excited + + + align:start position:0% +Part D so it was probably being excited +harmonically at the natural frequency of + + align:start position:0% +harmonically at the natural frequency of + + + align:start position:0% +harmonically at the natural frequency of +mode two so what do you which mode so + + align:start position:0% +mode two so what do you which mode so + + + align:start position:0% +mode two so what do you which mode so +harmonic excitation which mode do you + + align:start position:0% +harmonic excitation which mode do you + + + align:start position:0% +harmonic excitation which mode do you +expect to respond the most when you + + align:start position:0% +expect to respond the most when you + + + align:start position:0% +expect to respond the most when you +excited at one of the natural + + align:start position:0% +excited at one of the natural + + + align:start position:0% +excited at one of the natural +frequencies at that natural frequency + + align:start position:0% +frequencies at that natural frequency + + + align:start position:0% +frequencies at that natural frequency +why why + + align:start position:0% + + + + align:start position:0% + +well there's an igen value there but now + + align:start position:0% +well there's an igen value there but now + + + align:start position:0% +well there's an igen value there but now +we're talking about steady state + + align:start position:0% +we're talking about steady state + + + align:start position:0% +we're talking about steady state +response what's the transfer function of + + align:start position:0% +response what's the transfer function of + + + align:start position:0% +response what's the transfer function of +a single degree of Freedom system look + + align:start position:0% +a single degree of Freedom system look + + + align:start position:0% +a single degree of Freedom system look +like just trace it in the + + align:start position:0% + + + + align:start position:0% + +air right this is the response per unit + + align:start position:0% +air right this is the response per unit + + + align:start position:0% +air right this is the response per unit +input and where does it go way up high + + align:start position:0% +input and where does it go way up high + + + align:start position:0% +input and where does it go way up high +at the resonance and so if you have a + + align:start position:0% +at the resonance and so if you have a + + + align:start position:0% +at the resonance and so if you have a +two degree Freedom system how many + + align:start position:0% +two degree Freedom system how many + + + align:start position:0% +two degree Freedom system how many +resonances do you have what do you think + + align:start position:0% +resonances do you have what do you think + + + align:start position:0% +resonances do you have what do you think +the transfer function is going to look + + align:start position:0% +the transfer function is going to look + + + align:start position:0% +the transfer function is going to look +like for a two degree of Freedom system + + align:start position:0% +like for a two degree of Freedom system + + + align:start position:0% +like for a two degree of Freedom system +if you just plotted it just as plot as a + + align:start position:0% +if you just plotted it just as plot as a + + + align:start position:0% +if you just plotted it just as plot as a +function + + align:start position:0% +function + + + align:start position:0% +function +frequency double Peak so the transfer + + align:start position:0% +frequency double Peak so the transfer + + + align:start position:0% +frequency double Peak so the transfer +function is likely to do that at one + + align:start position:0% +function is likely to do that at one + + + align:start position:0% +function is likely to do that at one +frequency and that at the next natural + + align:start position:0% +frequency and that at the next natural + + + align:start position:0% +frequency and that at the next natural +frequency okay and that's what we're + + align:start position:0% +frequency okay and that's what we're + + + align:start position:0% +frequency okay and that's what we're +going to talk about today in fact okay + + align:start position:0% +going to talk about today in fact okay + + + align:start position:0% +going to talk about today in fact okay +so if you excited the second natural + + align:start position:0% +so if you excited the second natural + + + align:start position:0% +so if you excited the second natural +frequency and it's lightly damped it's + + align:start position:0% +frequency and it's lightly damped it's + + + align:start position:0% +frequency and it's lightly damped it's +likely to be dominated by the second + + align:start position:0% +likely to be dominated by the second + + + align:start position:0% +likely to be dominated by the second +natur by the by that uh modal response + + align:start position:0% +natur by the by that uh modal response + + + align:start position:0% +natur by the by that uh modal response +is in that question if you is it + + align:start position:0% +is in that question if you is it + + + align:start position:0% +is in that question if you is it +guaranteed to be only that mode + + align:start position:0% +guaranteed to be only that mode + + + align:start position:0% +guaranteed to be only that mode +responding even if you drive it at the + + align:start position:0% +responding even if you drive it at the + + + align:start position:0% +responding even if you drive it at the +natural + + align:start position:0% +natural + + + align:start position:0% +natural +frequency another way to saying this + + align:start position:0% +frequency another way to saying this + + + align:start position:0% +frequency another way to saying this +question can the first mode have some + + align:start position:0% +question can the first mode have some + + + align:start position:0% +question can the first mode have some +response at any frequency you excite the + + align:start position:0% +response at any frequency you excite the + + + align:start position:0% +response at any frequency you excite the +system at sure it has transfer function + + align:start position:0% +system at sure it has transfer function + + + align:start position:0% +system at sure it has transfer function +it's continuous and frequency it just + + align:start position:0% +it's continuous and frequency it just + + + align:start position:0% +it's continuous and frequency it just +won't be very big okay + + align:start position:0% + + + + align:start position:0% + +next ah what the value for what value is + + align:start position:0% +next ah what the value for what value is + + + align:start position:0% +next ah what the value for what value is +a makeover megaan is the force + + align:start position:0% +a makeover megaan is the force + + + align:start position:0% +a makeover megaan is the force +transmitted to the wall going to be the + + align:start position:0% +transmitted to the wall going to be the + + + align:start position:0% +transmitted to the wall going to be the +greatest + + align:start position:0% +greatest + + + align:start position:0% +greatest +so this is when we make this this this + + align:start position:0% +so this is when we make this this this + + + align:start position:0% +so this is when we make this this this +is now we're doing + + align:start position:0% +is now we're doing + + + align:start position:0% +is now we're doing +the it's rotating around okay so this + + align:start position:0% +the it's rotating around okay so this + + + align:start position:0% +the it's rotating around okay so this +thing has rotating + + align:start position:0% +thing has rotating + + + align:start position:0% +thing has rotating +mass now at a constant frequency so it's + + align:start position:0% +mass now at a constant frequency so it's + + + align:start position:0% +mass now at a constant frequency so it's +got you know a static + + align:start position:0% +got you know a static + + + align:start position:0% +got you know a static +unbalance and at what frequency would + + align:start position:0% +unbalance and at what frequency would + + + align:start position:0% +unbalance and at what frequency would +you expect the force transmitted to the + + align:start position:0% +you expect the force transmitted to the + + + align:start position:0% +you expect the force transmitted to the +wall would be the greatest + + align:start position:0% + + + + align:start position:0% + +at resonance because that's when you get + + align:start position:0% +at resonance because that's when you get + + + align:start position:0% +at resonance because that's when you get +the + + align:start position:0% +the + + + align:start position:0% +the +most response greatest response and the + + align:start position:0% +most response greatest response and the + + + align:start position:0% +most response greatest response and the +force transmitted to the wall is through + + align:start position:0% +force transmitted to the wall is through + + + align:start position:0% +force transmitted to the wall is through +the spring and through the dashbot and + + align:start position:0% +the spring and through the dashbot and + + + align:start position:0% +the spring and through the dashbot and +the bigger the Motions the bigger those + + align:start position:0% +the bigger the Motions the bigger those + + + align:start position:0% +the bigger the Motions the bigger those +forces are going to be okay + + align:start position:0% +forces are going to be okay + + + align:start position:0% +forces are going to be okay +next and so this is now if you account + + align:start position:0% +next and so this is now if you account + + + align:start position:0% +next and so this is now if you account +for the spring do you expect accounting + + align:start position:0% +for the spring do you expect accounting + + + align:start position:0% +for the spring do you expect accounting +for the mass of the spring to increase + + align:start position:0% +for the mass of the spring to increase + + + align:start position:0% +for the mass of the spring to increase +the predicted natural frequency or + + align:start position:0% +the predicted natural frequency or + + + align:start position:0% +the predicted natural frequency or +decrease it + + align:start position:0% + + + + align:start position:0% + +decrease I mean natural frequencies + + align:start position:0% +decrease I mean natural frequencies + + + align:start position:0% +decrease I mean natural frequencies +behave like square root of K Over M kind + + align:start position:0% +behave like square root of K Over M kind + + + align:start position:0% +behave like square root of K Over M kind +of thing right if you do anything that + + align:start position:0% +of thing right if you do anything that + + + align:start position:0% +of thing right if you do anything that +drives up the M natural frequency is + + align:start position:0% +drives up the M natural frequency is + + + align:start position:0% +drives up the M natural frequency is +going to go down another way of asking + + align:start position:0% +going to go down another way of asking + + + align:start position:0% +going to go down another way of asking +the same question is if you neglect Mass + + align:start position:0% +the same question is if you neglect Mass + + + align:start position:0% +the same question is if you neglect Mass +when you're estimating the natural + + align:start position:0% +when you're estimating the natural + + + align:start position:0% +when you're estimating the natural +frequency of a system how which way are + + align:start position:0% +frequency of a system how which way are + + + align:start position:0% +frequency of a system how which way are +you likely to be in + + align:start position:0% +you likely to be in + + + align:start position:0% +you likely to be in +error so when you this system normally + + align:start position:0% +error so when you this system normally + + + align:start position:0% +error so when you this system normally +we just ignore the mass of the springs + + align:start position:0% +we just ignore the mass of the springs + + + align:start position:0% +we just ignore the mass of the springs +and we calculate the natural frequency + + align:start position:0% +and we calculate the natural frequency + + + align:start position:0% +and we calculate the natural frequency +ofun of K Over m and we're almost + + align:start position:0% +ofun of K Over m and we're almost + + + align:start position:0% +ofun of K Over m and we're almost +certain to be predict what too high or + + align:start position:0% +certain to be predict what too high or + + + align:start position:0% +certain to be predict what too high or +too + + align:start position:0% +too + + + align:start position:0% +too +low too high because we've ignored some + + align:start position:0% +low too high because we've ignored some + + + align:start position:0% +low too high because we've ignored some +mass in the system okay next I think + + align:start position:0% +mass in the system okay next I think + + + align:start position:0% +mass in the system okay next I think +that's + + align:start position:0% +that's + + + align:start position:0% +that's +it I want to get on with today's lecture + + align:start position:0% +it I want to get on with today's lecture + + + align:start position:0% +it I want to get on with today's lecture +we + + align:start position:0% +we + + + align:start position:0% +we +have done vibration from the point of + + align:start position:0% +have done vibration from the point of + + + align:start position:0% +have done vibration from the point of +view of single deegree Freedom systems + + align:start position:0% +view of single deegree Freedom systems + + + align:start position:0% +view of single deegree Freedom systems +transient response and steady state + + align:start position:0% +transient response and steady state + + + align:start position:0% +transient response and steady state +response and then we've started looking + + align:start position:0% +response and then we've started looking + + + align:start position:0% +response and then we've started looking +at multiple degree of Freedom systems + + align:start position:0% +at multiple degree of Freedom systems + + + align:start position:0% +at multiple degree of Freedom systems +but we actually started it from the + + align:start position:0% +but we actually started it from the + + + align:start position:0% +but we actually started it from the +point of view of modal analysis and we + + align:start position:0% +point of view of modal analysis and we + + + align:start position:0% +point of view of modal analysis and we +looked at two degree Freedom systems and + + align:start position:0% +looked at two degree Freedom systems and + + + align:start position:0% +looked at two degree Freedom systems and +found out found the modal contributions + + align:start position:0% +found out found the modal contributions + + + align:start position:0% +found out found the modal contributions +of each of the modes and sort of did + + align:start position:0% +of each of the modes and sort of did + + + align:start position:0% +of each of the modes and sort of did +them one at a time so is there another + + align:start position:0% +them one at a time so is there another + + + align:start position:0% +them one at a time so is there another +way one some one of you asked me after + + align:start position:0% +way one some one of you asked me after + + + align:start position:0% +way one some one of you asked me after +class last time well can't you just + + align:start position:0% +class last time well can't you just + + + align:start position:0% +class last time well can't you just +solve the equation the differential + + align:start position:0% +solve the equation the differential + + + align:start position:0% +solve the equation the differential +equations directly and not bother with + + align:start position:0% +equations directly and not bother with + + + align:start position:0% +equations directly and not bother with +separating the modes out and figuring + + align:start position:0% +separating the modes out and figuring + + + align:start position:0% +separating the modes out and figuring +out the modal contributions the answer + + align:start position:0% +out the modal contributions the answer + + + align:start position:0% +out the modal contributions the answer +is yes and you do it by a transfer + + align:start position:0% +is yes and you do it by a transfer + + + align:start position:0% +is yes and you do it by a transfer +functions except now you will need more + + align:start position:0% +functions except now you will need more + + + align:start position:0% +functions except now you will need more +than one if you have more than one + + align:start position:0% +than one if you have more than one + + + align:start position:0% +than one if you have more than one +degree of Freedom + + align:start position:0% +degree of Freedom + + + align:start position:0% +degree of Freedom +so that's we're going that's what we'll + + align:start position:0% +so that's we're going that's what we'll + + + align:start position:0% +so that's we're going that's what we'll +uh focus on + + align:start position:0% + + + + align:start position:0% + +today and we're going to do it + + align:start position:0% +today and we're going to do it + + + align:start position:0% +today and we're going to do it +by thinking about the + + align:start position:0% +by thinking about the + + + align:start position:0% +by thinking about the +example actually from the homework so in + + align:start position:0% +example actually from the homework so in + + + align:start position:0% +example actually from the homework so in +the homework you have this problem of + + align:start position:0% +the homework you have this problem of + + + align:start position:0% +the homework you have this problem of +this + + align:start position:0% + + + + align:start position:0% + +cart with the uh p with the + + align:start position:0% +cart with the uh p with the + + + align:start position:0% +cart with the uh p with the +this pendulum hanging off of + + align:start position:0% +this pendulum hanging off of + + + align:start position:0% +this pendulum hanging off of +it and we in problem three I think it is + + align:start position:0% +it and we in problem three I think it is + + + align:start position:0% +it and we in problem three I think it is +to say okay now the pendulum is going to + + align:start position:0% +to say okay now the pendulum is going to + + + align:start position:0% +to say okay now the pendulum is going to +around go around a constant rate and + + align:start position:0% +around go around a constant rate and + + + align:start position:0% +around go around a constant rate and +it's going to turn this into a rotating + + align:start position:0% +it's going to turn this into a rotating + + + align:start position:0% +it's going to turn this into a rotating +imbalance problem and I short and the I + + align:start position:0% +imbalance problem and I short and the I + + + align:start position:0% +imbalance problem and I short and the I +shorten it up so it's just a little Mass + + align:start position:0% +shorten it up so it's just a little Mass + + + align:start position:0% +shorten it up so it's just a little Mass +spinning + + align:start position:0% +spinning + + + align:start position:0% +spinning +around you have + + align:start position:0% +around you have + + + align:start position:0% +around you have +K1 + + align:start position:0% + + + + align:start position:0% + +C1 X1 here + + align:start position:0% +C1 X1 here + + + align:start position:0% +C1 X1 here +and I think it's drawn there as + + align:start position:0% +and I think it's drawn there as + + + align:start position:0% +and I think it's drawn there as +Theta this is point a about which it + + align:start position:0% + + + + align:start position:0% + +spins and you know the nonlinear + + align:start position:0% +spins and you know the nonlinear + + + align:start position:0% +spins and you know the nonlinear +equations of motion when for treating + + align:start position:0% +equations of motion when for treating + + + align:start position:0% +equations of motion when for treating +this as a simp as a two degree of + + align:start position:0% +this as a simp as a two degree of + + + align:start position:0% +this as a simp as a two degree of +Freedom system just a pendulum on a + + align:start position:0% + + + + align:start position:0% + +cart and that nonlinear + + align:start position:0% + + + + align:start position:0% + +equation of + + align:start position:0% + + + + align:start position:0% + +motion and I'm going to put subscripts + + align:start position:0% +motion and I'm going to put subscripts + + + align:start position:0% +motion and I'm going to put subscripts +here now I'm going to call this + + align:start position:0% +here now I'm going to call this + + + align:start position:0% +here now I'm going to call this +coordinate X1 because we're going to + + align:start position:0% +coordinate X1 because we're going to + + + align:start position:0% +coordinate X1 because we're going to +need a second second + + align:start position:0% +need a second second + + + align:start position:0% +need a second second +coordinate + + align:start position:0% +coordinate + + + align:start position:0% +coordinate +uh actually do we what am I saying we + + align:start position:0% +uh actually do we what am I saying we + + + align:start position:0% +uh actually do we what am I saying we +don't need to do + + align:start position:0% +don't need to do + + + align:start position:0% +don't need to do +that just X will do + + align:start position:0% + + + + align:start position:0% + +we do need the M1 and M2 though and so + + align:start position:0% +we do need the M1 and M2 though and so + + + align:start position:0% +we do need the M1 and M2 though and so +that is all I'm going to move the + + align:start position:0% +that is all I'm going to move the + + + align:start position:0% +that is all I'm going to move the +remaining stuff to the right hand side + + align:start position:0% +remaining stuff to the right hand side + + + align:start position:0% +remaining stuff to the right hand side +so this is your + + align:start position:0% + + + + align:start position:0% + +nonlinear + + align:start position:0% +nonlinear + + + align:start position:0% +nonlinear +M2 + + align:start position:0% +M2 + + + align:start position:0% +M2 +L Theta dble + + align:start position:0% +L Theta dble + + + align:start position:0% +L Theta dble +dot cos + + align:start position:0% +dot cos + + + align:start position:0% +dot cos +Theta minus Theta do^ + + align:start position:0% +Theta minus Theta do^ + + + align:start position:0% +Theta minus Theta do^ +SAR s sin + + align:start position:0% + + + + align:start position:0% + +Theta on the right hand + + align:start position:0% +Theta on the right hand + + + align:start position:0% +Theta on the right hand +side and I think I need a minus if I do + + align:start position:0% +side and I think I need a minus if I do + + + align:start position:0% +side and I think I need a minus if I do +that now what I do in this problem I + + align:start position:0% +that now what I do in this problem I + + + align:start position:0% +that now what I do in this problem I +said let's let Theta dot equal Omega and + + align:start position:0% +said let's let Theta dot equal Omega and + + + align:start position:0% +said let's let Theta dot equal Omega and +that's a + + align:start position:0% + + + + align:start position:0% + +constant and so that says Theta double + + align:start position:0% +constant and so that says Theta double + + + align:start position:0% +constant and so that says Theta double +dot is zero when you do that then this + + align:start position:0% +dot is zero when you do that then this + + + align:start position:0% +dot is zero when you do that then this +term goes away and this becomes Omega s + + align:start position:0% +term goes away and this becomes Omega s + + + align:start position:0% +term goes away and this becomes Omega s +s minus * a minus this equals + + align:start position:0% +s minus * a minus this equals + + + align:start position:0% +s minus * a minus this equals + + align:start position:0% + + + align:start position:0% +M2 + + align:start position:0% +M2 + + + align:start position:0% +M2 +L Omega + + align:start position:0% +L Omega + + + align:start position:0% +L Omega +squar + + align:start position:0% +squar + + + align:start position:0% +squar +s and Theta is just Omega + + align:start position:0% + + + + align:start position:0% + +T So by + + align:start position:0% +T So by + + + align:start position:0% +T So by +forcing what was previously a unknown + + align:start position:0% +forcing what was previously a unknown + + + align:start position:0% +forcing what was previously a unknown +variable that you had to solve in this + + align:start position:0% +variable that you had to solve in this + + + align:start position:0% +variable that you had to solve in this +two for you had two equations and two + + align:start position:0% +two for you had two equations and two + + + align:start position:0% +two for you had two equations and two +unknown because you had two generalized + + align:start position:0% +unknown because you had two generalized + + + align:start position:0% +unknown because you had two generalized +coordinates that took to describe the + + align:start position:0% +coordinates that took to describe the + + + align:start position:0% +coordinates that took to describe the +motion of this thing X and Theta now + + align:start position:0% +motion of this thing X and Theta now + + + align:start position:0% +motion of this thing X and Theta now +once you prescribe Theta and it's given + + align:start position:0% +once you prescribe Theta and it's given + + + align:start position:0% +once you prescribe Theta and it's given +it's no longer a variable it's no longer + + align:start position:0% +it's no longer a variable it's no longer + + + align:start position:0% +it's no longer a variable it's no longer +a coordinate in your generalized in your + + align:start position:0% +a coordinate in your generalized in your + + + align:start position:0% +a coordinate in your generalized in your +equations of motion you have to solve + + align:start position:0% +equations of motion you have to solve + + + align:start position:0% +equations of motion you have to solve +for and it reduces this first dis + + align:start position:0% +for and it reduces this first dis + + + align:start position:0% +for and it reduces this first dis +equation to the equation of a single + + align:start position:0% +equation to the equation of a single + + + align:start position:0% +equation to the equation of a single +degree Freedom system on the left hand + + align:start position:0% +degree Freedom system on the left hand + + + align:start position:0% +degree Freedom system on the left hand +side is the response quantities just + + align:start position:0% +side is the response quantities just + + + align:start position:0% +side is the response quantities just +like usual MX do plus CX do plus KX and + + align:start position:0% +like usual MX do plus CX do plus KX and + + + align:start position:0% +like usual MX do plus CX do plus KX and +on the right hand side is a harmonic + + align:start position:0% +on the right hand side is a harmonic + + + align:start position:0% +on the right hand side is a harmonic +excitation and that's this unbalanced + + align:start position:0% +excitation and that's this unbalanced + + + align:start position:0% +excitation and that's this unbalanced +Mass going round and + + align:start position:0% +Mass going round and + + + align:start position:0% +Mass going round and +round so this has the form here this is + + align:start position:0% +round so this has the form here this is + + + align:start position:0% +round so this has the form here this is +some if you want to think of it this way + + align:start position:0% +some if you want to think of it this way + + + align:start position:0% +some if you want to think of it this way +this is some f + + align:start position:0% + + + + align:start position:0% + +KN and it looks like sin Omega T so this + + align:start position:0% +KN and it looks like sin Omega T so this + + + align:start position:0% +KN and it looks like sin Omega T so this +is just a single degree Freedom system + + align:start position:0% +is just a single degree Freedom system + + + align:start position:0% +is just a single degree Freedom system +excited by harmonic excitation and you + + align:start position:0% +excited by harmonic excitation and you + + + align:start position:0% +excited by harmonic excitation and you +know what it has a transfer function and + + align:start position:0% +know what it has a transfer function and + + + align:start position:0% +know what it has a transfer function and +you know know that there's going to be a + + align:start position:0% +you know know that there's going to be a + + + align:start position:0% +you know know that there's going to be a +resonance at the natural frequency of + + align:start position:0% +resonance at the natural frequency of + + + align:start position:0% +resonance at the natural frequency of +the + + align:start position:0% + + + + align:start position:0% + +system and if you don't like working + + align:start position:0% +system and if you don't like working + + + align:start position:0% +system and if you don't like working +with s Omega T you know you could say + + align:start position:0% +with s Omega T you know you could say + + + align:start position:0% +with s Omega T you know you could say +well let's measure Omega Theta from here + + align:start position:0% +well let's measure Omega Theta from here + + + align:start position:0% +well let's measure Omega Theta from here +if you wanted to and now that's cosine + + align:start position:0% +if you wanted to and now that's cosine + + + align:start position:0% +if you wanted to and now that's cosine +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +t Okay + + align:start position:0% + + + + align:start position:0% + +so that's sort of the setup + + align:start position:0% + + + + align:start position:0% + +let me say one if I ask you to solve for + + align:start position:0% +let me say one if I ask you to solve for + + + align:start position:0% +let me say one if I ask you to solve for +the magnitude of the + + align:start position:0% +the magnitude of the + + + align:start position:0% +the magnitude of the +response X1 + + align:start position:0% + + + + align:start position:0% + +here how would you do + + align:start position:0% + + + + align:start position:0% + +it so this is now single degree Freedom + + align:start position:0% +it so this is now single degree Freedom + + + align:start position:0% +it so this is now single degree Freedom +system excited by harmonic excitation + + align:start position:0% +system excited by harmonic excitation + + + align:start position:0% +system excited by harmonic excitation +steady state response how do you do + + align:start position:0% + + + + align:start position:0% + +it this you do have to + + align:start position:0% + + + + align:start position:0% + +know transfer function use a transfer + + align:start position:0% +know transfer function use a transfer + + + align:start position:0% +know transfer function use a transfer +function right so this is going to be + + align:start position:0% +function right so this is going to be + + + align:start position:0% +function right so this is going to be +the magnitude of the force times the + + align:start position:0% +the magnitude of the force times the + + + align:start position:0% +the magnitude of the force times the +magnitude of the + + align:start position:0% +magnitude of the + + + align:start position:0% +magnitude of the +HX F of Omega transfer + + align:start position:0% +HX F of Omega transfer + + + align:start position:0% +HX F of Omega transfer +function and that's how You' get the + + align:start position:0% +function and that's how You' get the + + + align:start position:0% +function and that's how You' get the +magnitude of the response and it + + align:start position:0% +magnitude of the response and it + + + align:start position:0% +magnitude of the response and it +happened to be at resonance then you + + align:start position:0% +happened to be at resonance then you + + + align:start position:0% +happened to be at resonance then you +know you'd be at the peak and if you're + + align:start position:0% +know you'd be at the peak and if you're + + + align:start position:0% +know you'd be at the peak and if you're +not at resonance wherever you happen to + + align:start position:0% +not at resonance wherever you happen to + + + align:start position:0% +not at resonance wherever you happen to +be in frequency is where you would + + align:start position:0% +be in frequency is where you would + + + align:start position:0% +be in frequency is where you would +evaluate this and there's your + + align:start position:0% +evaluate this and there's your + + + align:start position:0% +evaluate this and there's your +response + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +now a few years + + align:start position:0% +now a few years + + + align:start position:0% +now a few years +ago we every year twice a year in fact + + align:start position:0% +ago we every year twice a year in fact + + + align:start position:0% +ago we every year twice a year in fact +in they coming up in January we have + + align:start position:0% +in they coming up in January we have + + + align:start position:0% +in they coming up in January we have +doctoral exams for students who want to + + align:start position:0% +doctoral exams for students who want to + + + align:start position:0% +doctoral exams for students who want to +do phds in mechanical engineering and + + align:start position:0% +do phds in mechanical engineering and + + + align:start position:0% +do phds in mechanical engineering and +most departments at MIT have these also + + align:start position:0% +most departments at MIT have these also + + + align:start position:0% +most departments at MIT have these also +and in there's an in the Dynamics + + align:start position:0% +and in there's an in the Dynamics + + + align:start position:0% +and in there's an in the Dynamics +portion there's an oral exam part + + align:start position:0% +portion there's an oral exam part + + + align:start position:0% +portion there's an oral exam part +there's a written exam also but in the + + align:start position:0% +there's a written exam also but in the + + + align:start position:0% +there's a written exam also but in the +oral exam in + + align:start position:0% +oral exam in + + + align:start position:0% +oral exam in +this in this particular + + align:start position:0% +this in this particular + + + align:start position:0% +this in this particular +year gave a single degree Freedom system + + align:start position:0% + + + + align:start position:0% + +and we posed and we all know that if we + + align:start position:0% +and we posed and we all know that if we + + + align:start position:0% +and we posed and we all know that if we +excite this thing with + + align:start position:0% +excite this thing with + + + align:start position:0% +excite this thing with +a harmonic excitation some + + align:start position:0% +a harmonic excitation some + + + align:start position:0% +a harmonic excitation some +F1 + + align:start position:0% +F1 + + + align:start position:0% +F1 +cosine and I will I'll use complex + + align:start position:0% +cosine and I will I'll use complex + + + align:start position:0% +cosine and I will I'll use complex +notation because we're going to need it + + align:start position:0% +notation because we're going to need it + + + align:start position:0% +notation because we're going to need it +in a minute some fub1 e to the I Omega T + + align:start position:0% +in a minute some fub1 e to the I Omega T + + + align:start position:0% +in a minute some fub1 e to the I Omega T +that's the excitation we know what the + + align:start position:0% +that's the excitation we know what the + + + align:start position:0% +that's the excitation we know what the +steady state response to this looks like + + align:start position:0% +steady state response to this looks like + + + align:start position:0% +steady state response to this looks like +the magnitude looks like looks like that + + align:start position:0% +the magnitude looks like looks like that + + + align:start position:0% +the magnitude looks like looks like that +transfer function + + align:start position:0% +transfer function + + + align:start position:0% +transfer function +right but we Poe so most doctoral + + align:start position:0% +right but we Poe so most doctoral + + + align:start position:0% +right but we Poe so most doctoral +students would be doctoral students + + align:start position:0% +students would be doctoral students + + + align:start position:0% +students would be doctoral students +would know all about a single degree of + + align:start position:0% +would know all about a single degree of + + + align:start position:0% +would know all about a single degree of +Freedom system so we POS the following + + align:start position:0% +Freedom system so we POS the following + + + align:start position:0% +Freedom system so we POS the following +question well we know that the response + + align:start position:0% +question well we know that the response + + + align:start position:0% +question well we know that the response +of this is going to you know do + + align:start position:0% +of this is going to you know do + + + align:start position:0% +of this is going to you know do +something like + + align:start position:0% +something like + + + align:start position:0% +something like +that and and you evaluate this at + + align:start position:0% +that and and you evaluate this at + + + align:start position:0% +that and and you evaluate this at +Whatever frequency you're interested in + + align:start position:0% +Whatever frequency you're interested in + + + align:start position:0% +Whatever frequency you're interested in +including right at + + align:start position:0% +including right at + + + align:start position:0% +including right at +resonance and the question we ask is it + + align:start position:0% +resonance and the question we ask is it + + + align:start position:0% +resonance and the question we ask is it +possible to add a second spring + + align:start position:0% +possible to add a second spring + + + align:start position:0% +possible to add a second spring +and a second Mass + + align:start position:0% +and a second Mass + + + align:start position:0% +and a second Mass +M2 and + + align:start position:0% +M2 and + + + align:start position:0% +M2 and +K2 such + + align:start position:0% + + + + align:start position:0% + +that so is it possible to pick a K2 and + + align:start position:0% +that so is it possible to pick a K2 and + + + align:start position:0% +that so is it possible to pick a K2 and +an M2 such that with this excitation on + + align:start position:0% +an M2 such that with this excitation on + + + align:start position:0% +an M2 such that with this excitation on +here the motion of that thing will be + + align:start position:0% +here the motion of that thing will be + + + align:start position:0% +here the motion of that thing will be +zero okay and in order to solve this + + align:start position:0% +zero okay and in order to solve this + + + align:start position:0% +zero okay and in order to solve this +problem as soon as you put this on here + + align:start position:0% +problem as soon as you put this on here + + + align:start position:0% +problem as soon as you put this on here +and assume it's it's you know sliding + + align:start position:0% +and assume it's it's you know sliding + + + align:start position:0% +and assume it's it's you know sliding +along it's not can't fall it only has + + align:start position:0% +along it's not can't fall it only has + + + align:start position:0% +along it's not can't fall it only has +horizontal possible motion and we'd give + + align:start position:0% +horizontal possible motion and we'd give + + + align:start position:0% +horizontal possible motion and we'd give +it some coordinate describing it motion + + align:start position:0% +it some coordinate describing it motion + + + align:start position:0% +it some coordinate describing it motion +X2 so now how many degrees of freedom + + align:start position:0% +X2 so now how many degrees of freedom + + + align:start position:0% +X2 so now how many degrees of freedom +does this problem + + align:start position:0% +does this problem + + + align:start position:0% +does this problem +have two how many equations of motion do + + align:start position:0% +have two how many equations of motion do + + + align:start position:0% +have two how many equations of motion do +you + + align:start position:0% +you + + + align:start position:0% +you +expect okay how many peaks in this in a + + align:start position:0% +expect okay how many peaks in this in a + + + align:start position:0% +expect okay how many peaks in this in a +transfer function would you expect to + + align:start position:0% +transfer function would you expect to + + + align:start position:0% +transfer function would you expect to +see two resonances okay so now we need + + align:start position:0% +see two resonances okay so now we need + + + align:start position:0% +see two resonances okay so now we need +to know we need to know how to find + + align:start position:0% +to know we need to know how to find + + + align:start position:0% +to know we need to know how to find +transfer functions for a multiple degree + + align:start position:0% +transfer functions for a multiple degree + + + align:start position:0% +transfer functions for a multiple degree +Freedom system so in in everything I've + + align:start position:0% +Freedom system so in in everything I've + + + align:start position:0% +Freedom system so in in everything I've +said about two degree of Freedom systems + + align:start position:0% +said about two degree of Freedom systems + + + align:start position:0% +said about two degree of Freedom systems +I've + + align:start position:0% +I've + + + align:start position:0% +I've +been every is everything is + + align:start position:0% +been every is everything is + + + align:start position:0% +been every is everything is +generalizable to end degrees of freedom + + align:start position:0% +generalizable to end degrees of freedom + + + align:start position:0% +generalizable to end degrees of freedom +so what I'm going to show you now is how + + align:start position:0% +so what I'm going to show you now is how + + + align:start position:0% +so what I'm going to show you now is how +to do transfer function funs for multi- + + align:start position:0% +to do transfer function funs for multi- + + + align:start position:0% +to do transfer function funs for multi- +deegree Freedom systems and I'm going to + + align:start position:0% +deegree Freedom systems and I'm going to + + + align:start position:0% +deegree Freedom systems and I'm going to +do it by way of example of a two degree + + align:start position:0% +do it by way of example of a two degree + + + align:start position:0% +do it by way of example of a two degree +Freedom one but just keep in mind that + + align:start position:0% +Freedom one but just keep in mind that + + + align:start position:0% +Freedom one but just keep in mind that +you can General completely generalize + + align:start position:0% +you can General completely generalize + + + align:start position:0% +you can General completely generalize +this so + + align:start position:0% +this so + + + align:start position:0% +this so +here's there's my system two masses two + + align:start position:0% +here's there's my system two masses two + + + align:start position:0% +here's there's my system two masses two +Springs and I could even have dashbot in + + align:start position:0% +Springs and I could even have dashbot in + + + align:start position:0% +Springs and I could even have dashbot in +here a C1 and I might have a + + align:start position:0% + + + + align:start position:0% + +C2 okay + + align:start position:0% + + + + align:start position:0% + +and I could even in general additionally + + align:start position:0% +and I could even in general additionally + + + align:start position:0% +and I could even in general additionally +have a force acting on the second Mass + + align:start position:0% +have a force acting on the second Mass + + + align:start position:0% +have a force acting on the second Mass +which I'll call F2 e to the I Omega T so + + align:start position:0% +which I'll call F2 e to the I Omega T so + + + align:start position:0% +which I'll call F2 e to the I Omega T so +that's kind of that's a completely + + align:start position:0% +that's kind of that's a completely + + + align:start position:0% +that's kind of that's a completely +General problem + + align:start position:0% + + + + align:start position:0% + +now now the equations of + + align:start position:0% + + + + align:start position:0% + +motion for this system you could write + + align:start position:0% +motion for this system you could write + + + align:start position:0% +motion for this system you could write +down I'm we've done it many times now + + align:start position:0% +down I'm we've done it many times now + + + align:start position:0% +down I'm we've done it many times now +this particular system even but we could + + align:start position:0% +this particular system even but we could + + + align:start position:0% +this particular system even but we could +write them in Matrix form as + + align:start position:0% +write them in Matrix form as + + + align:start position:0% +write them in Matrix form as +m xou dot plus c x dot plus a + + align:start position:0% +m xou dot plus c x dot plus a + + + align:start position:0% +m xou dot plus c x dot plus a +k stiffness Matrix x + + align:start position:0% +k stiffness Matrix x + + + align:start position:0% +k stiffness Matrix x +equals an excite the excitation in this + + align:start position:0% +equals an excite the excitation in this + + + align:start position:0% +equals an excite the excitation in this +two degree well I'll just keep this + + align:start position:0% +two degree well I'll just keep this + + + align:start position:0% +two degree well I'll just keep this +completely General this is any in in + + align:start position:0% +completely General this is any in in + + + align:start position:0% +completely General this is any in in +degree of Freedom system some f e to the + + align:start position:0% +degree of Freedom system some f e to the + + + align:start position:0% +degree of Freedom system some f e to the +I Omega + + align:start position:0% +I Omega + + + align:start position:0% +I Omega +T so here's kind of an important + + align:start position:0% +T so here's kind of an important + + + align:start position:0% +T so here's kind of an important +point we write out a set of we solve for + + align:start position:0% +point we write out a set of we solve for + + + align:start position:0% +point we write out a set of we solve for +the motion of a multiple degree Freedom + + align:start position:0% +the motion of a multiple degree Freedom + + + align:start position:0% +the motion of a multiple degree Freedom +system to a harmonic input we do it one + + align:start position:0% +system to a harmonic input we do it one + + + align:start position:0% +system to a harmonic input we do it one +frequency at a time so this doesn't mean + + align:start position:0% +frequency at a time so this doesn't mean + + + align:start position:0% +frequency at a time so this doesn't mean +that I could have force on the first + + align:start position:0% +that I could have force on the first + + + align:start position:0% +that I could have force on the first +mass at Omega one or make or at any at + + align:start position:0% +mass at Omega one or make or at any at + + + align:start position:0% +mass at Omega one or make or at any at +some omega and force of the second mass + + align:start position:0% +some omega and force of the second mass + + + align:start position:0% +some omega and force of the second mass +at some other Omega I'd never do that at + + align:start position:0% +at some other Omega I'd never do that at + + + align:start position:0% +at some other Omega I'd never do that at +the same time it's a linear system + + align:start position:0% +the same time it's a linear system + + + align:start position:0% +the same time it's a linear system +superposition holds you do things one + + align:start position:0% +superposition holds you do things one + + + align:start position:0% +superposition holds you do things one +frequency at a time get the answer and + + align:start position:0% +frequency at a time get the answer and + + + align:start position:0% +frequency at a time get the answer and +if you have another frequency part you + + align:start position:0% +if you have another frequency part you + + + align:start position:0% +if you have another frequency part you +do that separately then add the two + + align:start position:0% +do that separately then add the two + + + align:start position:0% +do that separately then add the two +answers so this is assumed all the + + align:start position:0% +answers so this is assumed all the + + + align:start position:0% +answers so this is assumed all the +forces acting on the masses are assumed + + align:start position:0% +forces acting on the masses are assumed + + + align:start position:0% +forces acting on the masses are assumed +to occur at one frequency but you can + + align:start position:0% +to occur at one frequency but you can + + + align:start position:0% +to occur at one frequency but you can +have different amplitudes on the + + align:start position:0% +have different amplitudes on the + + + align:start position:0% +have different amplitudes on the +different + + align:start position:0% +different + + + align:start position:0% +different +masses so that's what that + + align:start position:0% + + + + align:start position:0% + +means so this then for the two degree of + + align:start position:0% +means so this then for the two degree of + + + align:start position:0% +means so this then for the two degree of +Freedom system + + align:start position:0% + + + + align:start position:0% + +f for example F of + + align:start position:0% +f for example F of + + + align:start position:0% +f for example F of +T would be some constant F1 another + + align:start position:0% +T would be some constant F1 another + + + align:start position:0% +T would be some constant F1 another +constant magnitude FS2 e to the I Omega + + align:start position:0% +constant magnitude FS2 e to the I Omega + + + align:start position:0% +constant magnitude FS2 e to the I Omega +T that's what we mean by + + align:start position:0% +T that's what we mean by + + + align:start position:0% +T that's what we mean by +that so in this system and then what do + + align:start position:0% +that so in this system and then what do + + + align:start position:0% +that so in this system and then what do +we what's actually if you do that if + + align:start position:0% +we what's actually if you do that if + + + align:start position:0% +we what's actually if you do that if +these are just constants it's some + + align:start position:0% +these are just constants it's some + + + align:start position:0% +these are just constants it's some +constant force Vector appli it at a + + align:start position:0% +constant force Vector appli it at a + + + align:start position:0% +constant force Vector appli it at a +single + + align:start position:0% +single + + + align:start position:0% +single +frequency what frequency do you expect + + align:start position:0% +frequency what frequency do you expect + + + align:start position:0% +frequency what frequency do you expect +to see in the response of the system + + align:start position:0% +to see in the response of the system + + + align:start position:0% +to see in the response of the system +steady state + + align:start position:0% + + + + align:start position:0% + +response right it's a linear system one + + align:start position:0% +response right it's a linear system one + + + align:start position:0% +response right it's a linear system one +of the lessons you really got want to go + + align:start position:0% +of the lessons you really got want to go + + + align:start position:0% +of the lessons you really got want to go +away with this is an intro to linear + + align:start position:0% +away with this is an intro to linear + + + align:start position:0% +away with this is an intro to linear +system steady state response of a linear + + align:start position:0% +system steady state response of a linear + + + align:start position:0% +system steady state response of a linear +system the frequency in is the frequency + + align:start position:0% +system the frequency in is the frequency + + + align:start position:0% +system the frequency in is the frequency +out + + align:start position:0% +out + + + align:start position:0% +out +okay all always true so we expect to see + + align:start position:0% +okay all always true so we expect to see + + + align:start position:0% +okay all always true so we expect to see +a solution + + align:start position:0% + + + + align:start position:0% + +we're going to get a solution of the + + align:start position:0% +we're going to get a solution of the + + + align:start position:0% +we're going to get a solution of the +form + + align:start position:0% +form + + + align:start position:0% +form +x equals some + + align:start position:0% +x equals some + + + align:start position:0% +x equals some +magnitude Vector times an e to the I + + align:start position:0% +magnitude Vector times an e to the I + + + align:start position:0% +magnitude Vector times an e to the I +Omega T also and the magnitude might be + + align:start position:0% +Omega T also and the magnitude might be + + + align:start position:0% +Omega T also and the magnitude might be +complex because there could be phase + + align:start position:0% +complex because there could be phase + + + align:start position:0% +complex because there could be phase +angle in there due to damping and so + + align:start position:0% +angle in there due to damping and so + + + align:start position:0% +angle in there due to damping and so +forth but they nonetheless they're + + align:start position:0% +forth but they nonetheless they're + + + align:start position:0% +forth but they nonetheless they're +constant what this part is a constant + + align:start position:0% +constant what this part is a constant + + + align:start position:0% +constant what this part is a constant +vector and that's its frequency + + align:start position:0% +vector and that's its frequency + + + align:start position:0% +vector and that's its frequency +dependence and if we know that is true + + align:start position:0% +dependence and if we know that is true + + + align:start position:0% +dependence and if we know that is true +then we can say well take the time + + align:start position:0% +then we can say well take the time + + + align:start position:0% +then we can say well take the time +derivative of that the only time + + align:start position:0% +derivative of that the only time + + + align:start position:0% +derivative of that the only time +dependent part is the e to the I Omega T + + align:start position:0% +dependent part is the e to the I Omega T + + + align:start position:0% +dependent part is the e to the I Omega T +So X do becomes I + + align:start position:0% +So X do becomes I + + + align:start position:0% +So X do becomes I +Omega + + align:start position:0% +Omega + + + align:start position:0% +Omega +x e to the I Omega T and X double dot + + align:start position:0% +x e to the I Omega T and X double dot + + + align:start position:0% +x e to the I Omega T and X double dot +becomes minus Omega + + align:start position:0% +becomes minus Omega + + + align:start position:0% +becomes minus Omega +SAR x e to the I Omega + + align:start position:0% +SAR x e to the I Omega + + + align:start position:0% +SAR x e to the I Omega +T so we can substitute this this and + + align:start position:0% +T so we can substitute this this and + + + align:start position:0% +T so we can substitute this this and +this into this + + align:start position:0% +this into this + + + align:start position:0% +this into this +equation this is these are Matrix + + align:start position:0% + + + + align:start position:0% + +equation and when you do + + align:start position:0% +equation and when you do + + + align:start position:0% +equation and when you do +that minus Omega 2 * the mass + + align:start position:0% +that minus Omega 2 * the mass + + + align:start position:0% +that minus Omega 2 * the mass +Matrix I Omega * the C Matrix plus k + + align:start position:0% +Matrix I Omega * the C Matrix plus k + + + align:start position:0% +Matrix I Omega * the C Matrix plus k +k + + align:start position:0% + + + + align:start position:0% + +x e to the I Omega T + + align:start position:0% +x e to the I Omega T + + + align:start position:0% +x e to the I Omega T +equals Fe e to the I Omega + + align:start position:0% +equals Fe e to the I Omega + + + align:start position:0% +equals Fe e to the I Omega +T you can get rid of these and now you + + align:start position:0% +T you can get rid of these and now you + + + align:start position:0% +T you can get rid of these and now you +have a algebraic equation it's no longer + + align:start position:0% +have a algebraic equation it's no longer + + + align:start position:0% +have a algebraic equation it's no longer +a function of + + align:start position:0% +a function of + + + align:start position:0% +a function of +time function of your original Mass + + align:start position:0% +time function of your original Mass + + + align:start position:0% +time function of your original Mass +stamping and stiffness matrices and it's + + align:start position:0% +stamping and stiffness matrices and it's + + + align:start position:0% +stamping and stiffness matrices and it's +certainly a function of frequency and if + + align:start position:0% +certainly a function of frequency and if + + + align:start position:0% +certainly a function of frequency and if +you think back this is how how we derive + + align:start position:0% +you think back this is how how we derive + + + align:start position:0% +you think back this is how how we derive +the transfer function for a single + + align:start position:0% +the transfer function for a single + + + align:start position:0% +the transfer function for a single +degree Freedom system and this statement + + align:start position:0% +degree Freedom system and this statement + + + align:start position:0% +degree Freedom system and this statement +is true for single degree Freedom too if + + align:start position:0% +is true for single degree Freedom too if + + + align:start position:0% +is true for single degree Freedom too if +it was single degree Freedom that's just + + align:start position:0% +it was single degree Freedom that's just + + + align:start position:0% +it was single degree Freedom that's just +the mass that's just the damping that's + + align:start position:0% +the mass that's just the damping that's + + + align:start position:0% +the mass that's just the damping that's +just the + + align:start position:0% +just the + + + align:start position:0% +just the +stiffness and you could solve directly + + align:start position:0% +stiffness and you could solve directly + + + align:start position:0% +stiffness and you could solve directly +for the HX over F transfer function but + + align:start position:0% +for the HX over F transfer function but + + + align:start position:0% +for the HX over F transfer function but +with multiple degrees of freedom we + + align:start position:0% +with multiple degrees of freedom we + + + align:start position:0% +with multiple degrees of freedom we +can't just divide this quite divide this + + align:start position:0% +can't just divide this quite divide this + + + align:start position:0% +can't just divide this quite divide this +out this piece + + align:start position:0% +out this piece + + + align:start position:0% +out this piece +Here is known as the I'll write it as Z + + align:start position:0% +Here is known as the I'll write it as Z + + + align:start position:0% +Here is known as the I'll write it as Z +Omega Z of Omega this is known as the + + align:start position:0% +Omega Z of Omega this is known as the + + + align:start position:0% +Omega Z of Omega this is known as the +impedance + + align:start position:0% + + + + align:start position:0% + +Matrix and if I want to solve I'm + + align:start position:0% +Matrix and if I want to solve I'm + + + align:start position:0% +Matrix and if I want to solve I'm +looking for X I want to know my solution + + align:start position:0% +looking for X I want to know my solution + + + align:start position:0% +looking for X I want to know my solution +X so this is essentially of the form + + align:start position:0% +X so this is essentially of the form + + + align:start position:0% +X so this is essentially of the form +Z it's a matrix time x a vector equals f + + align:start position:0% +Z it's a matrix time x a vector equals f + + + align:start position:0% +Z it's a matrix time x a vector equals f +a + + align:start position:0% +a + + + align:start position:0% +a +vector and just using what you know + + align:start position:0% +vector and just using what you know + + + align:start position:0% +vector and just using what you know +about linear algebra to solve for x you + + align:start position:0% +about linear algebra to solve for x you + + + align:start position:0% +about linear algebra to solve for x you +just multiply through by Z + + align:start position:0% +just multiply through by Z + + + align:start position:0% +just multiply through by Z +inverse so + + align:start position:0% +inverse so + + + align:start position:0% +inverse so +x equals z inverse + + align:start position:0% + + + + align:start position:0% + +F + + align:start position:0% +F + + + align:start position:0% +F +right and Z is a for a two degree + + align:start position:0% +right and Z is a for a two degree + + + align:start position:0% +right and Z is a for a two degree +Freedom system Z is a 2X two Matrix with + + align:start position:0% +Freedom system Z is a 2X two Matrix with + + + align:start position:0% +Freedom system Z is a 2X two Matrix with +frequency and everything in it but it's + + align:start position:0% +frequency and everything in it but it's + + + align:start position:0% +frequency and everything in it but it's +a 2X two so Z inverse will be a 2X two + + align:start position:0% +a 2X two so Z inverse will be a 2X two + + + align:start position:0% +a 2X two so Z inverse will be a 2X two +and for 2 x two we can just write down + + align:start position:0% +and for 2 x two we can just write down + + + align:start position:0% +and for 2 x two we can just write down +the + + align:start position:0% +the + + + align:start position:0% +the +answer but let's see I'll write out Z of + + align:start position:0% +answer but let's see I'll write out Z of + + + align:start position:0% +answer but let's see I'll write out Z of +Omega + + align:start position:0% + + + + align:start position:0% + +here so just to be clear about what all + + align:start position:0% +here so just to be clear about what all + + + align:start position:0% +here so just to be clear about what all +this is z of Omega is this and in this + + align:start position:0% +this is z of Omega is this and in this + + + align:start position:0% +this is z of Omega is this and in this +problem that's minus Omega s + + align:start position:0% +problem that's minus Omega s + + + align:start position:0% +problem that's minus Omega s +times a mass Matrix which looks like M1 + + align:start position:0% +times a mass Matrix which looks like M1 + + + align:start position:0% +times a mass Matrix which looks like M1 +0 0 + + align:start position:0% +0 0 + + + align:start position:0% +0 0 +M2 and you add to that a damping Matrix + + align:start position:0% +M2 and you add to that a damping Matrix + + + align:start position:0% +M2 and you add to that a damping Matrix +I Omega time C and the C from the + + align:start position:0% +I Omega time C and the C from the + + + align:start position:0% +I Omega time C and the C from the +equations of motion C1 + + + align:start position:0% +equations of motion C1 + + + + align:start position:0% +equations of motion C1 + +C2 minus C2 minus C2 + + align:start position:0% + + + + align:start position:0% + +C2 and plus r k Matrix + + align:start position:0% + + + + align:start position:0% + +K1 + + + align:start position:0% +K1 + + + + align:start position:0% +K1 + +K2 minus + + align:start position:0% +K2 minus + + + align:start position:0% +K2 minus +K2 minus + + align:start position:0% +K2 minus + + + align:start position:0% +K2 minus +K2 + + align:start position:0% +K2 + + + align:start position:0% +K2 +K2 so that's what the ZM of Omega + + align:start position:0% +K2 so that's what the ZM of Omega + + + align:start position:0% +K2 so that's what the ZM of Omega +actually looks + + align:start position:0% +actually looks + + + align:start position:0% +actually looks +like and so you would collect so the it + + align:start position:0% +like and so you would collect so the it + + + align:start position:0% +like and so you would collect so the it +it's a 2X two Matrix and its F upper + + align:start position:0% +it's a 2X two Matrix and its F upper + + + align:start position:0% +it's a 2X two Matrix and its F upper +left term is- Omega 2 M1 plus I Omega + + align:start position:0% +left term is- Omega 2 M1 plus I Omega + + + align:start position:0% +left term is- Omega 2 M1 plus I Omega +time this plus that collect them all + + align:start position:0% +time this plus that collect them all + + + align:start position:0% +time this plus that collect them all +together and this has a + + align:start position:0% +together and this has a + + + align:start position:0% +together and this has a +form this collects together in a form we + + align:start position:0% +form this collects together in a form we + + + align:start position:0% +form this collects together in a form we +have called + + align:start position:0% +have called + + + align:start position:0% +have called +z11 + + align:start position:0% +z11 + + + align:start position:0% +z11 +z12 + + align:start position:0% +z12 + + + align:start position:0% +z12 +z21 + + align:start position:0% + + + + align:start position:0% + +z22 and very often z12 and z21 are + + align:start position:0% +z22 and very often z12 and z21 are + + + align:start position:0% +z22 and very often z12 and z21 are +symmetric not always the kind of + + align:start position:0% +symmetric not always the kind of + + + align:start position:0% +symmetric not always the kind of +problems we generally do here they will + + align:start position:0% +problems we generally do here they will + + + align:start position:0% +problems we generally do here they will +be and they will be generally symmetric + + align:start position:0% +be and they will be generally symmetric + + + align:start position:0% +be and they will be generally symmetric +if your coordinate system is measured + + align:start position:0% +if your coordinate system is measured + + + align:start position:0% +if your coordinate system is measured +from a stable measured from a static + + align:start position:0% +from a stable measured from a static + + + align:start position:0% +from a stable measured from a static +equilibrium position so if you've been + + align:start position:0% +equilibrium position so if you've been + + + align:start position:0% +equilibrium position so if you've been +doing two1 there's a thing called + + align:start position:0% +doing two1 there's a thing called + + + align:start position:0% +doing two1 there's a thing called +Maxwell's reciprocal theorem which for + + align:start position:0% +Maxwell's reciprocal theorem which for + + + align:start position:0% +Maxwell's reciprocal theorem which for +which proves this for the stiffness + + align:start position:0% +which proves this for the stiffness + + + align:start position:0% +which proves this for the stiffness +Matrix but they essentially need to be + + align:start position:0% +Matrix but they essentially need to be + + + align:start position:0% +Matrix but they essentially need to be +measured from static equilibrium + + align:start position:0% +measured from static equilibrium + + + align:start position:0% +measured from static equilibrium +positions but for today's example this + + align:start position:0% +positions but for today's example this + + + align:start position:0% +positions but for today's example this +is indeed symmetric minus C2 minus C2 + + align:start position:0% +is indeed symmetric minus C2 minus C2 + + + align:start position:0% +is indeed symmetric minus C2 minus C2 +minus K2 minus K2 0 0 everything + + align:start position:0% +minus K2 minus K2 0 0 everything + + + align:start position:0% +minus K2 minus K2 0 0 everything +symmetric so we'll take advantage of + + align:start position:0% +symmetric so we'll take advantage of + + + align:start position:0% +symmetric so we'll take advantage of +that and I'll write out one of the + + align:start position:0% +that and I'll write out one of the + + + align:start position:0% +that and I'll write out one of the +components here z11 for example when you + + align:start position:0% +components here z11 for example when you + + + align:start position:0% +components here z11 for example when you +collect the terms + + align:start position:0% + + + + align:start position:0% + +together + + align:start position:0% +together + + + align:start position:0% +together +is in general it' be minus Omega + + align:start position:0% +is in general it' be minus Omega + + + align:start position:0% +is in general it' be minus Omega +SAR + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +M11 + I Omega C1 11 1 plus k11 the + + align:start position:0% +M11 + I Omega C1 11 1 plus k11 the + + + align:start position:0% +M11 + I Omega C1 11 1 plus k11 the +corner elements of these three + + align:start position:0% +corner elements of these three + + + align:start position:0% +corner elements of these three +pieces + + align:start position:0% + + + + align:start position:0% + +and in this problem that's + + align:start position:0% +and in this problem that's + + + align:start position:0% +and in this problem that's +minus Omega SAR + + align:start position:0% +minus Omega SAR + + + align:start position:0% +minus Omega SAR +M1 + + align:start position:0% +M1 + + + align:start position:0% +M1 +plus I + + align:start position:0% +plus I + + + align:start position:0% +plus I +Omega C1 + C2 + + align:start position:0% + + + + align:start position:0% + +plus K1 + + align:start position:0% +plus K1 + + + align:start position:0% +plus K1 ++ K2 you just substitute it + + align:start position:0% ++ K2 you just substitute it + + + align:start position:0% ++ K2 you just substitute it +in this this and this so that's z11 for + + align:start position:0% +in this this and this so that's z11 for + + + align:start position:0% +in this this and this so that's z11 for +example and the other ones you can + + align:start position:0% +example and the other ones you can + + + align:start position:0% +example and the other ones you can +figure out what each of the other terms + + align:start position:0% +figure out what each of the other terms + + + align:start position:0% +figure out what each of the other terms +would be + + align:start position:0% + + + + align:start position:0% + +all right so we've said that we're + + align:start position:0% +all right so we've said that we're + + + align:start position:0% +all right so we've said that we're +looking we want to know what the X's + + align:start position:0% +looking we want to know what the X's + + + align:start position:0% +looking we want to know what the X's +are and we know that we can get that by + + align:start position:0% +are and we know that we can get that by + + + align:start position:0% +are and we know that we can get that by +doing Z inverse time + + align:start position:0% +doing Z inverse time + + + align:start position:0% +doing Z inverse time +F and this is going this gives us our + + align:start position:0% +F and this is going this gives us our + + + align:start position:0% +F and this is going this gives us our +definition this Z inverse is our + + align:start position:0% +definition this Z inverse is our + + + align:start position:0% +definition this Z inverse is our +H our transfer function Matrix + + align:start position:0% +H our transfer function Matrix + + + align:start position:0% +H our transfer function Matrix +times F so just by getting Z inverse we + + align:start position:0% +times F so just by getting Z inverse we + + + align:start position:0% +times F so just by getting Z inverse we +get this little set of trans four + + align:start position:0% +get this little set of trans four + + + align:start position:0% +get this little set of trans four +transfer functions that we're interested + + align:start position:0% +transfer functions that we're interested + + + align:start position:0% +transfer functions that we're interested +in so + + align:start position:0% +in so + + + align:start position:0% +in so +H is an N + + align:start position:0% +H is an N + + + align:start position:0% +H is an N +byn + + align:start position:0% + + + + align:start position:0% + +Matrix of transfer + + align:start position:0% + + + + align:start position:0% + +functions + + align:start position:0% +functions + + + align:start position:0% +functions +okay so in the 2 by two + + align:start position:0% +okay so in the 2 by two + + + align:start position:0% +okay so in the 2 by two +for the or for the 2x two case or n + + align:start position:0% +for the or for the 2x two case or n + + + align:start position:0% +for the or for the 2x two case or n +equals + + align:start position:0% +equals + + + align:start position:0% +equals +2 we know we can write out directly what + + align:start position:0% +2 we know we can write out directly what + + + align:start position:0% +2 we know we can write out directly what +Z inverse + + align:start position:0% +Z inverse + + + align:start position:0% +Z inverse +is and Z + + align:start position:0% + + + + align:start position:0% + +inverse + + align:start position:0% + + + + align:start position:0% + +z22 minus + + align:start position:0% +z22 minus + + + align:start position:0% +z22 minus +z12 minus z12 when it's + + align:start position:0% +z12 minus z12 when it's + + + align:start position:0% +z12 minus z12 when it's +symmetric z11 + + align:start position:0% +symmetric z11 + + + align:start position:0% +symmetric z11 +all + + align:start position:0% + + + + align:start position:0% + +over I write it all over the + + align:start position:0% +over I write it all over the + + + align:start position:0% +over I write it all over the +determinant of Z so this is the + + align:start position:0% + + + + align:start position:0% + +determinant so the determinant of Z I + + align:start position:0% +determinant so the determinant of Z I + + + align:start position:0% +determinant so the determinant of Z I +just do with these double bars so the + + align:start position:0% +just do with these double bars so the + + + align:start position:0% +just do with these double bars so the +whole this over the determinant of Z is + + align:start position:0% +whole this over the determinant of Z is + + + align:start position:0% +whole this over the determinant of Z is +the inverse of that + + align:start position:0% +the inverse of that + + + align:start position:0% +the inverse of that +Matrix and this gives you a new result + + align:start position:0% +Matrix and this gives you a new result + + + align:start position:0% +Matrix and this gives you a new result +which is + + align:start position:0% +which is + + + align:start position:0% +which is +h11 + + align:start position:0% +h11 + + + align:start position:0% +h11 +h12 + + align:start position:0% +h12 + + + align:start position:0% +h12 +h12 + + align:start position:0% + + + + align:start position:0% + +H22 where + + align:start position:0% +H22 where + + + align:start position:0% +H22 where +H I + + align:start position:0% +H I + + + align:start position:0% +H I +J this is the + + align:start position:0% + + + + align:start position:0% + +response at + + align:start position:0% +response at + + + align:start position:0% +response at +I + + align:start position:0% +I + + + align:start position:0% +I +per + + align:start position:0% +per + + + align:start position:0% +per +unit Force at + + align:start position:0% +unit Force at + + + align:start position:0% +unit Force at +J and I made this I I took advantage of + + align:start position:0% +J and I made this I I took advantage of + + + align:start position:0% +J and I made this I I took advantage of +the Symmetry here but this one would + + align:start position:0% +the Symmetry here but this one would + + + align:start position:0% +the Symmetry here but this one would +normally be called 2 one so this is + + align:start position:0% +normally be called 2 one so this is + + + align:start position:0% +normally be called 2 one so this is +response at one caused by the force at + + align:start position:0% +response at one caused by the force at + + + align:start position:0% +response at one caused by the force at +one so we + + align:start position:0% +one so we + + + align:start position:0% +one so we +have forces in our problem one is the + + align:start position:0% +have forces in our problem one is the + + + align:start position:0% +have forces in our problem one is the +force on the main Mass so how much + + align:start position:0% +force on the main Mass so how much + + + align:start position:0% +force on the main Mass so how much +response do you get at the main first + + align:start position:0% +response do you get at the main first + + + align:start position:0% +response do you get at the main first +mass due to the force on the first mass + + align:start position:0% +mass due to the force on the first mass + + + align:start position:0% +mass due to the force on the first mass +this is how much response you get on the + + align:start position:0% +this is how much response you get on the + + + align:start position:0% +this is how much response you get on the +first mass due to the excitation on the + + align:start position:0% +first mass due to the excitation on the + + + align:start position:0% +first mass due to the excitation on the +second Mass response on the second Mass + + align:start position:0% +second Mass response on the second Mass + + + align:start position:0% +second Mass response on the second Mass +due to the excitation on the first + + align:start position:0% +due to the excitation on the first + + + align:start position:0% +due to the excitation on the first +response on the second Mass due to the + + align:start position:0% +response on the second Mass due to the + + + align:start position:0% +response on the second Mass due to the +excitation on the second Mass so you get + + align:start position:0% +excitation on the second Mass so you get + + + align:start position:0% +excitation on the second Mass so you get +four possible contributions + + align:start position:0% +four possible contributions + + + align:start position:0% +four possible contributions +here + + align:start position:0% +here + + + align:start position:0% +here +okay and the determinant to + + align:start position:0% + + + + align:start position:0% + +Z for 2x two is also very + + align:start position:0% +Z for 2x two is also very + + + align:start position:0% +Z for 2x two is also very +straightforward + + align:start position:0% +straightforward + + + align:start position:0% +straightforward +z11 + + align:start position:0% +z11 + + + align:start position:0% +z11 +z22 minus Z1 2 + + align:start position:0% +z22 minus Z1 2 + + + align:start position:0% +z22 minus Z1 2 +squared so we can actually so we can and + + align:start position:0% +squared so we can actually so we can and + + + align:start position:0% +squared so we can actually so we can and +will work out uh exactly what the + + align:start position:0% +will work out uh exactly what the + + + align:start position:0% +will work out uh exactly what the +algebra tells us for this 2 by two + + align:start position:0% +algebra tells us for this 2 by two + + + align:start position:0% +algebra tells us for this 2 by two +case so we've already been discussing it + + align:start position:0% +case so we've already been discussing it + + + align:start position:0% +case so we've already been discussing it +but what do you expect let's say let's + + align:start position:0% +but what do you expect let's say let's + + + align:start position:0% +but what do you expect let's say let's +look at this one what do you suppose the + + align:start position:0% +look at this one what do you suppose the + + + align:start position:0% +look at this one what do you suppose the +response at one due to a harmonic + + align:start position:0% + + + + align:start position:0% + +excitation at one what + + align:start position:0% +excitation at one what + + + align:start position:0% +excitation at one what +how what do you think the sketch of the + + align:start position:0% +how what do you think the sketch of the + + + align:start position:0% +how what do you think the sketch of the +magnitude of + + align:start position:0% +magnitude of + + + align:start position:0% +magnitude of +h11 of Omega would look like as a + + align:start position:0% +h11 of Omega would look like as a + + + align:start position:0% +h11 of Omega would look like as a +function of + + align:start position:0% + + + + align:start position:0% + +frequency + + align:start position:0% +frequency + + + align:start position:0% +frequency +no but for the kind of problems we do + + align:start position:0% +no but for the kind of problems we do + + + align:start position:0% +no but for the kind of problems we do +probably and if it's simple beams or + + align:start position:0% +probably and if it's simple beams or + + + align:start position:0% +probably and if it's simple beams or +masses connected by strings by Springs + + align:start position:0% +masses connected by strings by Springs + + + align:start position:0% +masses connected by strings by Springs +if you choose your generalized + + align:start position:0% +if you choose your generalized + + + align:start position:0% +if you choose your generalized +coordinates in a way that is for example + + align:start position:0% +coordinates in a way that is for example + + + align:start position:0% +coordinates in a way that is for example +measuring the displacement of each Mass + + align:start position:0% +measuring the displacement of each Mass + + + align:start position:0% +measuring the displacement of each Mass +from an inertial static equilibrium + + align:start position:0% +from an inertial static equilibrium + + + align:start position:0% +from an inertial static equilibrium +starting point it'll be + + align:start position:0% +starting point it'll be + + + align:start position:0% +starting point it'll be +symmetric but if you if you measure the + + align:start position:0% +symmetric but if you if you measure the + + + align:start position:0% +symmetric but if you if you measure the +even in this two degree freedom I can + + align:start position:0% +even in this two degree freedom I can + + + align:start position:0% +even in this two degree freedom I can +make it non-symmetric just by choosing + + align:start position:0% +make it non-symmetric just by choosing + + + align:start position:0% +make it non-symmetric just by choosing +the coordinate for the second mass as to + + align:start position:0% +the coordinate for the second mass as to + + + align:start position:0% +the coordinate for the second mass as to +be relative to the first mass as soon as + + align:start position:0% +be relative to the first mass as soon as + + + align:start position:0% +be relative to the first mass as soon as +you do that it makes it non-symmetric + + align:start position:0% +you do that it makes it non-symmetric + + + align:start position:0% +you do that it makes it non-symmetric +you can still solve for transfer + + align:start position:0% +you can still solve for transfer + + + align:start position:0% +you can still solve for transfer +function to everything but it's mess it + + align:start position:0% +function to everything but it's mess it + + + align:start position:0% +function to everything but it's mess it +get gets Messier so notice I picked + + align:start position:0% +get gets Messier so notice I picked + + + align:start position:0% +get gets Messier so notice I picked +coordinates X1 relative to the inertial + + align:start position:0% +coordinates X1 relative to the inertial + + + align:start position:0% +coordinates X1 relative to the inertial +frame X2 relative to the same inertial + + align:start position:0% +frame X2 relative to the same inertial + + + align:start position:0% +frame X2 relative to the same inertial +frame and they're both measuring + + align:start position:0% +frame and they're both measuring + + + align:start position:0% +frame and they're both measuring +displacement from a static equilibrium + + align:start position:0% +displacement from a static equilibrium + + + align:start position:0% +displacement from a static equilibrium +position then then they are symmetric so + + align:start position:0% +position then then they are symmetric so + + + align:start position:0% +position then then they are symmetric so +and there's the determinant we need and + + align:start position:0% +and there's the determinant we need and + + + align:start position:0% +and there's the determinant we need and +this determinant see this is divided + + align:start position:0% +this determinant see this is divided + + + align:start position:0% +this determinant see this is divided +into all four of these + + align:start position:0% +into all four of these + + + align:start position:0% +into all four of these +terms so these four transfer functions + + align:start position:0% +terms so these four transfer functions + + + align:start position:0% +terms so these four transfer functions +all share the same denominator + + align:start position:0% + + + + align:start position:0% + +okay they all have the same denominator + + align:start position:0% +okay they all have the same denominator + + + align:start position:0% +okay they all have the same denominator +so I just want you to tell me use your + + align:start position:0% +so I just want you to tell me use your + + + align:start position:0% +so I just want you to tell me use your +intuition tell me what this is going to + + align:start position:0% +intuition tell me what this is going to + + + align:start position:0% +intuition tell me what this is going to +look + + align:start position:0% + + + + align:start position:0% + +like what's it look like for a single + + align:start position:0% +like what's it look like for a single + + + align:start position:0% +like what's it look like for a single +degree Freedom + + align:start position:0% +degree Freedom + + + align:start position:0% +degree Freedom +system it's hxf for a single degree fre + + align:start position:0% +system it's hxf for a single degree fre + + + align:start position:0% +system it's hxf for a single degree fre +it's h11 for a single degree Freedom + + align:start position:0% +it's h11 for a single degree Freedom + + + align:start position:0% +it's h11 for a single degree Freedom +system is a response of the system to a + + align:start position:0% +system is a response of the system to a + + + align:start position:0% +system is a response of the system to a +harmonic force on that single mass and + + align:start position:0% +harmonic force on that single mass and + + + align:start position:0% +harmonic force on that single mass and +that looks like what + + align:start position:0% +that looks like what + + + align:start position:0% +that looks like what +Peak right okay this one what do you + + align:start position:0% +Peak right okay this one what do you + + + align:start position:0% +Peak right okay this one what do you +think it's going to look + + align:start position:0% + + + + align:start position:0% + +like show me + + align:start position:0% +like show me + + + align:start position:0% +like show me +again okay but I see one Peak how many + + align:start position:0% +again okay but I see one Peak how many + + + align:start position:0% +again okay but I see one Peak how many +Peaks + + align:start position:0% +Peaks + + + align:start position:0% +Peaks +why two different natural frequencies + + align:start position:0% +why two different natural frequencies + + + align:start position:0% +why two different natural frequencies +right this thing is going to look + + align:start position:0% +right this thing is going to look + + + align:start position:0% +right this thing is going to look +something like + + align:start position:0% +something like + + + align:start position:0% +something like +this and I don't know quite how it + + align:start position:0% +this and I don't know quite how it + + + align:start position:0% +this and I don't know quite how it +behaves in here but it's going to do + + align:start position:0% +behaves in here but it's going to do + + + align:start position:0% +behaves in here but it's going to do +that for sure it's going to have two + + align:start position:0% +that for sure it's going to have two + + + align:start position:0% +that for sure it's going to have two +resonances this one and Omega 1 this + + align:start position:0% +resonances this one and Omega 1 this + + + align:start position:0% +resonances this one and Omega 1 this +wanted Omega 2 we already know that + + align:start position:0% +wanted Omega 2 we already know that + + + align:start position:0% +wanted Omega 2 we already know that +because we did it by modal analysis we + + align:start position:0% +because we did it by modal analysis we + + + align:start position:0% +because we did it by modal analysis we +know each mode is going to have a + + align:start position:0% +know each mode is going to have a + + + align:start position:0% +know each mode is going to have a +resonance in it okay so let's let's + + align:start position:0% +resonance in it okay so let's let's + + + align:start position:0% +resonance in it okay so let's let's +figure let's find out exactly what it + + align:start position:0% +figure let's find out exactly what it + + + align:start position:0% +figure let's find out exactly what it +looks + + align:start position:0% + + + + align:start position:0% + +like so for this TW degree Freedom + + align:start position:0% +like so for this TW degree Freedom + + + align:start position:0% +like so for this TW degree Freedom +system there's an F1 and an + + align:start position:0% +system there's an F1 and an + + + align:start position:0% +system there's an F1 and an +F2 and we're looking for X1 + + align:start position:0% +F2 and we're looking for X1 + + + align:start position:0% +F2 and we're looking for X1 +so X1 X2 + + align:start position:0% +so X1 X2 + + + align:start position:0% +so X1 X2 +here + + align:start position:0% +here + + + align:start position:0% +here +equals + + align:start position:0% +equals + + + align:start position:0% +equals +h11 + + align:start position:0% +h11 + + + align:start position:0% +h11 +h12 + + align:start position:0% +h12 + + + align:start position:0% +h12 +h12 + + align:start position:0% +h12 + + + align:start position:0% +h12 +H22 + + align:start position:0% +H22 + + + align:start position:0% +H22 +times fub1 + + align:start position:0% +times fub1 + + + align:start position:0% +times fub1 +FS2 so if I want to solve for + + align:start position:0% +FS2 so if I want to solve for + + + align:start position:0% +FS2 so if I want to solve for +X1 it's + + align:start position:0% +X1 it's + + + align:start position:0% +X1 it's +h11 F1 Plus h12 + + align:start position:0% + + + + align:start position:0% + +F2 and for the problem I'm going to + + align:start position:0% +F2 and for the problem I'm going to + + + align:start position:0% +F2 and for the problem I'm going to +solve today I'm going to + + align:start position:0% +solve today I'm going to + + + align:start position:0% +solve today I'm going to +let FS2 be zero just to just to keep it + + align:start position:0% +let FS2 be zero just to just to keep it + + + align:start position:0% +let FS2 be zero just to just to keep it +simple but also to address the original + + align:start position:0% +simple but also to address the original + + + align:start position:0% +simple but also to address the original +question that we asked the doctoral + + align:start position:0% +question that we asked the doctoral + + + align:start position:0% +question that we asked the doctoral +students you have a force on the first + + align:start position:0% +students you have a force on the first + + + align:start position:0% +students you have a force on the first +mass can I add a mass and a spring to it + + align:start position:0% +mass can I add a mass and a spring to it + + + align:start position:0% +mass can I add a mass and a spring to it +and in such a way that I can make the + + align:start position:0% +and in such a way that I can make the + + + align:start position:0% +and in such a way that I can make the +response of the first mass go to zero so + + align:start position:0% +response of the first mass go to zero so + + + align:start position:0% +response of the first mass go to zero so +there is no second Force there's only a + + align:start position:0% +there is no second Force there's only a + + + align:start position:0% +there is no second Force there's only a +first for and so this term goes + + align:start position:0% +first for and so this term goes + + + align:start position:0% +first for and so this term goes +away and so this problem X1 is + + align:start position:0% +away and so this problem X1 is + + + align:start position:0% +away and so this problem X1 is +h11 + + align:start position:0% +h11 + + + align:start position:0% +h11 +F1 and we need therefore we need to know + + align:start position:0% +F1 and we need therefore we need to know + + + align:start position:0% +F1 and we need therefore we need to know +what + + align:start position:0% +what + + + align:start position:0% +what +uh h11 looks + + align:start position:0% + + + + align:start position:0% + +like so + + align:start position:0% +like so + + + align:start position:0% +like so +h11 is going to be + + align:start position:0% +h11 is going to be + + + align:start position:0% +h11 is going to be +z22 divided by the determinant + + align:start position:0% +z22 divided by the determinant + + + align:start position:0% +z22 divided by the determinant +so X1 is going to be + + align:start position:0% +so X1 is going to be + + + align:start position:0% +so X1 is going to be +z22 + + align:start position:0% +z22 + + + align:start position:0% +z22 +over z11 + + align:start position:0% +over z11 + + + align:start position:0% +over z11 +z22 minus z12 + + align:start position:0% +z22 minus z12 + + + align:start position:0% +z22 minus z12 +2ar times + + align:start position:0% + + + + align:start position:0% + +fub1 all right + + align:start position:0% + + + + align:start position:0% + +and actually I can do + + align:start position:0% +and actually I can do + + + align:start position:0% +and actually I can do +this + + align:start position:0% + + + + align:start position:0% + +so and I'm going to let for + + align:start position:0% + + + + align:start position:0% + +now damping be zero because it also just + + align:start position:0% +now damping be zero because it also just + + + align:start position:0% +now damping be zero because it also just +simplifies it for the purposes of + + align:start position:0% +simplifies it for the purposes of + + + align:start position:0% +simplifies it for the purposes of +illustration today and that's how it was + + align:start position:0% +illustration today and that's how it was + + + align:start position:0% +illustration today and that's how it was +posed to the doctoral student didn't + + align:start position:0% +posed to the doctoral student didn't + + + align:start position:0% +posed to the doctoral student didn't +even show any damping it was just a + + align:start position:0% +even show any damping it was just a + + + align:start position:0% +even show any damping it was just a +simple system a string and a + + align:start position:0% +simple system a string and a + + + align:start position:0% +simple system a string and a +mass how can you do this so we'll let + + align:start position:0% +mass how can you do this so we'll let + + + align:start position:0% +mass how can you do this so we'll let +the be zero and it considerably + + align:start position:0% +the be zero and it considerably + + + align:start position:0% +the be zero and it considerably +simplifies things then so + + align:start position:0% +simplifies things then so + + + align:start position:0% +simplifies things then so +um where's + + align:start position:0% + + + + align:start position:0% + +my so + + align:start position:0% + + + + align:start position:0% + +z11 is minus Omega 2ar M1 + + align:start position:0% + + + + align:start position:0% + +plus K1 + + + align:start position:0% + + + + align:start position:0% + +K2 + + align:start position:0% + + + + align:start position:0% + +z22 minus Omega 2 + + align:start position:0% +z22 minus Omega 2 + + + align:start position:0% +z22 minus Omega 2 +M2 plus + + align:start position:0% + + + + align:start position:0% + +K2 and + + align:start position:0% +K2 and + + + align:start position:0% +K2 and +z12 run out of room + + align:start position:0% + + + + align:start position:0% + +just minus + + align:start position:0% +just minus + + + align:start position:0% +just minus +K2 so now they're these are pretty + + align:start position:0% +K2 so now they're these are pretty + + + align:start position:0% +K2 so now they're these are pretty +simple expressions and all I have to do + + align:start position:0% +simple expressions and all I have to do + + + align:start position:0% +simple expressions and all I have to do +is plug them in here and notice what's + + align:start position:0% +is plug them in here and notice what's + + + align:start position:0% +is plug them in here and notice what's +going to happen z11 * + + align:start position:0% +going to happen z11 * + + + align:start position:0% +going to happen z11 * +z22 that's something involving aega SAR + + align:start position:0% +z22 that's something involving aega SAR + + + align:start position:0% +z22 that's something involving aega SAR +times another term involving Omega squar + + align:start position:0% +times another term involving Omega squar + + + align:start position:0% +times another term involving Omega squar +it's going to give you some a polinomial + + align:start position:0% +it's going to give you some a polinomial + + + align:start position:0% +it's going to give you some a polinomial +and Omega to the 4th this is a + + align:start position:0% +and Omega to the 4th this is a + + + align:start position:0% +and Omega to the 4th this is a +polinomial that has two roots and the + + align:start position:0% +polinomial that has two roots and the + + + align:start position:0% +polinomial that has two roots and the +two roots are + + align:start position:0% + + + + align:start position:0% + +yeah natural frequencies it's the same + + align:start position:0% +yeah natural frequencies it's the same + + + align:start position:0% +yeah natural frequencies it's the same +the determinant of this of the Z Matrix + + align:start position:0% +the determinant of this of the Z Matrix + + + align:start position:0% +the determinant of this of the Z Matrix +is the same problem you solve when you + + align:start position:0% +is the same problem you solve when you + + + align:start position:0% +is the same problem you solve when you +found the roots of the uh characteristic + + align:start position:0% +found the roots of the uh characteristic + + + align:start position:0% +found the roots of the uh characteristic +equation it is the characteristic + + align:start position:0% +equation it is the characteristic + + + align:start position:0% +equation it is the characteristic +equation for the system the denominator + + align:start position:0% +equation for the system the denominator + + + align:start position:0% +equation for the system the denominator +the determinant of the Z Matrix + + align:start position:0% +the determinant of the Z Matrix + + + align:start position:0% +the determinant of the Z Matrix +therefore it's going to be a fourth + + align:start position:0% +therefore it's going to be a fourth + + + align:start position:0% +therefore it's going to be a fourth +order equation Omega it'll give you two + + align:start position:0% +order equation Omega it'll give you two + + + align:start position:0% +order equation Omega it'll give you two +roots for Omega squar they're your two + + align:start position:0% +roots for Omega squar they're your two + + + align:start position:0% +roots for Omega squar they're your two +un damp natural frequencies when we + + align:start position:0% +un damp natural frequencies when we + + + align:start position:0% +un damp natural frequencies when we +leave damping out of this expression and + + align:start position:0% +leave damping out of this expression and + + + align:start position:0% +leave damping out of this expression and +they'd be damped the damped Expressions + + align:start position:0% +they'd be damped the damped Expressions + + + align:start position:0% +they'd be damped the damped Expressions +they'd have complex stuff in them if you + + align:start position:0% +they'd have complex stuff in them if you + + + align:start position:0% +they'd have complex stuff in them if you +leave in the damping but they give us + + align:start position:0% +leave in the damping but they give us + + + align:start position:0% +leave in the damping but they give us +our two roots and they go in the + + align:start position:0% +our two roots and they go in the + + + align:start position:0% +our two roots and they go in the +denominator yeah the + + align:start position:0% + + + + align:start position:0% + +denominator yeah yeah yeah this is that + + align:start position:0% +denominator yeah yeah yeah this is that + + + align:start position:0% +denominator yeah yeah yeah this is that +that denominator is the characteristic + + align:start position:0% +that denominator is the characteristic + + + align:start position:0% +that denominator is the characteristic +equation that we did when we set it up + + align:start position:0% +equation that we did when we set it up + + + align:start position:0% +equation that we did when we set it up +to do the natural + + align:start position:0% +to do the natural + + + align:start position:0% +to do the natural +frequencies same equation + + align:start position:0% +frequencies same equation + + + align:start position:0% +frequencies same equation +so we know that this thing has two Roots + + align:start position:0% +so we know that this thing has two Roots + + + align:start position:0% +so we know that this thing has two Roots +one at each of the natural frequencies + + align:start position:0% +one at each of the natural frequencies + + + align:start position:0% +one at each of the natural frequencies +and when you are when Omega is at a + + align:start position:0% +and when you are when Omega is at a + + + align:start position:0% +and when you are when Omega is at a +natural frequency what is the value of + + align:start position:0% +natural frequency what is the value of + + + align:start position:0% +natural frequency what is the value of +this characteristic + + align:start position:0% + + + + align:start position:0% + +equation well no the characterist + + align:start position:0% +equation well no the characterist + + + align:start position:0% +equation well no the characterist +equation thing in the + + align:start position:0% +equation thing in the + + + align:start position:0% +equation thing in the +denominator at a root that expression + + align:start position:0% +denominator at a root that expression + + + align:start position:0% +denominator at a root that expression +goes to zero so you're dividing by zero + + align:start position:0% +goes to zero so you're dividing by zero + + + align:start position:0% +goes to zero so you're dividing by zero +that's what causes the Peaks that's + + align:start position:0% +that's what causes the Peaks that's + + + align:start position:0% +that's what causes the Peaks that's +where the Peaks come from is where these + + align:start position:0% +where the Peaks come from is where these + + + align:start position:0% +where the Peaks come from is where these +that denominator goes to zero and that's + + align:start position:0% +that denominator goes to zero and that's + + + align:start position:0% +that denominator goes to zero and that's +at the natural + + align:start position:0% +at the natural + + + align:start position:0% +at the natural +frequencies + + align:start position:0% +frequencies + + + align:start position:0% +frequencies +okay + + align:start position:0% + + + + align:start position:0% + +so X1 for this problem equals + + align:start position:0% +so X1 for this problem equals + + + align:start position:0% +so X1 for this problem equals +h11 F1 and now we can just write it out + + align:start position:0% +h11 F1 and now we can just write it out + + + align:start position:0% +h11 F1 and now we can just write it out +h11 is minus Omega + + align:start position:0% +h11 is minus Omega + + + align:start position:0% +h11 is minus Omega +SAR + + align:start position:0% +SAR + + + align:start position:0% +SAR +M2 plus K2 + + align:start position:0% +M2 plus K2 + + + align:start position:0% +M2 plus K2 +time + + align:start position:0% +time + + + align:start position:0% +time +fub1 and the denominator the + + align:start position:0% +fub1 and the denominator the + + + align:start position:0% +fub1 and the denominator the +characteristic + + align:start position:0% +characteristic + + + align:start position:0% +characteristic +equation is minus Omega + + align:start position:0% +equation is minus Omega + + + align:start position:0% +equation is minus Omega +2ar M1 + + align:start position:0% +2ar M1 + + + align:start position:0% +2ar M1 ++ K1 + + + align:start position:0% ++ K1 + + + + align:start position:0% ++ K1 + +K2 * - Omega + + align:start position:0% +K2 * - Omega + + + align:start position:0% +K2 * - Omega +2ar + + align:start position:0% +2ar + + + align:start position:0% +2ar +M2 + + + align:start position:0% + + + + align:start position:0% + +K2 minus K2 + + align:start position:0% +K2 minus K2 + + + align:start position:0% +K2 minus K2 +2ar so so this whole thing down here + + align:start position:0% +2ar so so this whole thing down here + + + align:start position:0% +2ar so so this whole thing down here +there's your characteristic equation you + + align:start position:0% +there's your characteristic equation you + + + align:start position:0% +there's your characteristic equation you +multiply it out you get your fourth + + align:start position:0% +multiply it out you get your fourth + + + align:start position:0% +multiply it out you get your fourth +order polinomial solve it you get two + + align:start position:0% +order polinomial solve it you get two + + + align:start position:0% +order polinomial solve it you get two +Roots but this is now a total expression + + align:start position:0% +Roots but this is now a total expression + + + align:start position:0% +Roots but this is now a total expression +for the response we were looking + + align:start position:0% + + + + align:start position:0% + +for so this right right away this gives + + align:start position:0% +for so this right right away this gives + + + align:start position:0% +for so this right right away this gives +me the answer to the question that was + + align:start position:0% +me the answer to the question that was + + + align:start position:0% +me the answer to the question that was +posed to the doctoral + + align:start position:0% +posed to the doctoral + + + align:start position:0% +posed to the doctoral +students so as there a + + align:start position:0% +students so as there a + + + align:start position:0% +students so as there a +value can you set K2 and M2 such that + + align:start position:0% +value can you set K2 and M2 such that + + + align:start position:0% +value can you set K2 and M2 such that +you can make the response of the system + + align:start position:0% +you can make the response of the system + + + align:start position:0% +you can make the response of the system +zero at a at a particular + + align:start position:0% + + + + align:start position:0% + +Omega all you have to do is make the + + align:start position:0% +Omega all you have to do is make the + + + align:start position:0% +Omega all you have to do is make the +numerator go to zero right + + align:start position:0% +numerator go to zero right + + + align:start position:0% +numerator go to zero right +so if if you make this go to zero X goes + + align:start position:0% +so if if you make this go to zero X goes + + + align:start position:0% +so if if you make this go to zero X goes +to zero so X1 equals 0 + + align:start position:0% + + + + align:start position:0% + +when minus Omega SAR + + align:start position:0% +when minus Omega SAR + + + align:start position:0% +when minus Omega SAR +M2 + K2 equal Z and that happens when K2 + + align:start position:0% +M2 + K2 equal Z and that happens when K2 + + + align:start position:0% +M2 + K2 equal Z and that happens when K2 +over + + align:start position:0% +over + + + align:start position:0% +over +M2 equal Omega + + align:start position:0% + + + + align:start position:0% + +2 but so how many once you set K2 and + + align:start position:0% +2 but so how many once you set K2 and + + + align:start position:0% +2 but so how many once you set K2 and +M2 how many + + align:start position:0% +M2 how many + + + align:start position:0% +M2 how many +frequencies will does this happen + + align:start position:0% +frequencies will does this happen + + + align:start position:0% +frequencies will does this happen +at at how many different operating + + align:start position:0% +at at how many different operating + + + align:start position:0% +at at how many different operating +points can you make the response of that + + align:start position:0% +points can you make the response of that + + + align:start position:0% +points can you make the response of that +main Mass go to + + align:start position:0% + + + + align:start position:0% + +zero well just one once you choose k q + + align:start position:0% +zero well just one once you choose k q + + + align:start position:0% +zero well just one once you choose k q +and M2 whatever you've chosen to be they + + align:start position:0% +and M2 whatever you've chosen to be they + + + align:start position:0% +and M2 whatever you've chosen to be they +give you some value of Omega and when I + + align:start position:0% +give you some value of Omega and when I + + + align:start position:0% +give you some value of Omega and when I +said I was kind of vague about what + + align:start position:0% +said I was kind of vague about what + + + align:start position:0% +said I was kind of vague about what +happens here this is + + align:start position:0% + + + + align:start position:0% + +h11 looks like that and right here + + align:start position:0% +h11 looks like that and right here + + + align:start position:0% +h11 looks like that and right here +right here is + + align:start position:0% +right here is + + + align:start position:0% +right here is +when Omega 2ar = K2 + + align:start position:0% +when Omega 2ar = K2 + + + align:start position:0% +when Omega 2ar = K2 +over + + align:start position:0% + + + + align:start position:0% + +M2 theator Zer no no because look at the + + align:start position:0% +M2 theator Zer no no because look at the + + + align:start position:0% +M2 theator Zer no no because look at the +picture here where are the two natural + + align:start position:0% +picture here where are the two natural + + + align:start position:0% +picture here where are the two natural +frequencies of the + + align:start position:0% + + + + align:start position:0% + +system there's one here and there's one + + align:start position:0% +system there's one here and there's one + + + align:start position:0% +system there's one here and there's one +here and that's when the denominator + + align:start position:0% +here and that's when the denominator + + + align:start position:0% +here and that's when the denominator +goes to zero when the denominator goes + + align:start position:0% +goes to zero when the denominator goes + + + align:start position:0% +goes to zero when the denominator goes +to zero the response goes to Infinity + + align:start position:0% +to zero the response goes to Infinity + + + align:start position:0% +to zero the response goes to Infinity +with no damping so the system has two + + align:start position:0% +with no damping so the system has two + + + align:start position:0% +with no damping so the system has two +natural frequencies one to either side + + align:start position:0% +natural frequencies one to either side + + + align:start position:0% +natural frequencies one to either side +at this + + align:start position:0% + + + + align:start position:0% + +point so I've used I made the + + align:start position:0% +point so I've used I made the + + + align:start position:0% +point so I've used I made the +um I've picked kind of a particular + + align:start position:0% +um I've picked kind of a particular + + + align:start position:0% +um I've picked kind of a particular +example to illustrate the use of a + + align:start position:0% +example to illustrate the use of a + + + align:start position:0% +example to illustrate the use of a +transfer function and the fact that you + + align:start position:0% +transfer function and the fact that you + + + align:start position:0% +transfer function and the fact that you +can have transfer functions for multiple + + align:start position:0% +can have transfer functions for multiple + + + align:start position:0% +can have transfer functions for multiple +degree Freedom systems and they + + align:start position:0% +degree Freedom systems and they + + + align:start position:0% +degree Freedom systems and they +essentially become transfer function + + align:start position:0% +essentially become transfer function + + + align:start position:0% +essentially become transfer function +matrices and you use which what what you + + align:start position:0% +matrices and you use which what what you + + + align:start position:0% +matrices and you use which what what you +need and for this problem we needed + + align:start position:0% +need and for this problem we needed + + + align:start position:0% +need and for this problem we needed +h11 worked it out there it is this this + + align:start position:0% +h11 worked it out there it is this this + + + align:start position:0% +h11 worked it out there it is this this +is a complete equation that describes + + align:start position:0% +is a complete equation that describes + + + align:start position:0% +is a complete equation that describes +for me the behavior of mass one per unit + + align:start position:0% +for me the behavior of mass one per unit + + + align:start position:0% +for me the behavior of mass one per unit +input force as a function frequency and + + align:start position:0% +input force as a function frequency and + + + align:start position:0% +input force as a function frequency and +it will always have a point right there + + align:start position:0% +it will always have a point right there + + + align:start position:0% +it will always have a point right there +that it goes to + + align:start position:0% + + + + align:start position:0% + +zero okay and if we we don't have any + + align:start position:0% +zero okay and if we we don't have any + + + align:start position:0% +zero okay and if we we don't have any +damping in here right so intuitively + + align:start position:0% +damping in here right so intuitively + + + align:start position:0% +damping in here right so intuitively +what do you think damping will do to + + align:start position:0% +what do you think damping will do to + + + align:start position:0% +what do you think damping will do to +this + + align:start position:0% + + + + align:start position:0% + +plot what's first thing it does to the + + align:start position:0% +plot what's first thing it does to the + + + align:start position:0% +plot what's first thing it does to the +Peaks + + align:start position:0% +Peaks + + + align:start position:0% +Peaks +what they + + align:start position:0% +what they + + + align:start position:0% +what they +become finite right and so the small + + align:start position:0% +become finite right and so the small + + + align:start position:0% +become finite right and so the small +damping they going to have very high + + align:start position:0% +damping they going to have very high + + + align:start position:0% +damping they going to have very high +tops more damping they're going to be + + align:start position:0% +tops more damping they're going to be + + + align:start position:0% +tops more damping they're going to be +low + + align:start position:0% +low + + + align:start position:0% +low +so damping especially affects the Peaks + + align:start position:0% +so damping especially affects the Peaks + + + align:start position:0% +so damping especially affects the Peaks +damping will also pull this off the + + align:start position:0% +damping will also pull this off the + + + align:start position:0% +damping will also pull this off the +bottom a little bit it won't perfectly + + align:start position:0% +bottom a little bit it won't perfectly + + + align:start position:0% +bottom a little bit it won't perfectly +go to zero + + align:start position:0% + + + + align:start position:0% + +right so I'm going to do I want to do a + + align:start position:0% +right so I'm going to do I want to do a + + + align:start position:0% +right so I'm going to do I want to do a +very particular case so an obvious one + + align:start position:0% +very particular case so an obvious one + + + align:start position:0% +very particular case so an obvious one +is your original system it might be you + + align:start position:0% +is your original system it might be you + + + align:start position:0% +is your original system it might be you +know just a mass spring with a rotor in + + align:start position:0% +know just a mass spring with a rotor in + + + align:start position:0% +know just a mass spring with a rotor in +it that's unbalanced and it's running + + align:start position:0% +it that's unbalanced and it's running + + + align:start position:0% +it that's unbalanced and it's running +near reson and it's vibrating like crazy + + align:start position:0% +near reson and it's vibrating like crazy + + + align:start position:0% +near reson and it's vibrating like crazy +a single degree Freedom system vibrating + + align:start position:0% +a single degree Freedom system vibrating + + + align:start position:0% +a single degree Freedom system vibrating +like crazy can I put on a second Mass + + align:start position:0% +like crazy can I put on a second Mass + + + align:start position:0% +like crazy can I put on a second Mass +spring and stop the motion well look we + + align:start position:0% +spring and stop the motion well look we + + + align:start position:0% +spring and stop the motion well look we +can theoretically and we'll do we'll + + align:start position:0% +can theoretically and we'll do we'll + + + align:start position:0% +can theoretically and we'll do we'll +just say let's let the problem we're + + align:start position:0% +just say let's let the problem we're + + + align:start position:0% +just say let's let the problem we're +trying to solve that first system had a + + align:start position:0% +trying to solve that first system had a + + + align:start position:0% +trying to solve that first system had a +natural frequency I'll call it cap Omega + + align:start position:0% +natural frequency I'll call it cap Omega + + + align:start position:0% +natural frequency I'll call it cap Omega +n that was the square root of K1 over + + align:start position:0% +n that was the square root of K1 over + + + align:start position:0% +n that was the square root of K1 over +M1 and I'm going to let that be equal + + align:start position:0% +M1 and I'm going to let that be equal + + + align:start position:0% +M1 and I'm going to let that be equal +toare < TK of K2 over M2 so I've now + + align:start position:0% +toare < TK of K2 over M2 so I've now + + + align:start position:0% +toare < TK of K2 over M2 so I've now +chosen K2 and M2 such they're exactly at + + align:start position:0% +chosen K2 and M2 such they're exactly at + + + align:start position:0% +chosen K2 and M2 such they're exactly at +the natural frequency of the original + + align:start position:0% +the natural frequency of the original + + + align:start position:0% +the natural frequency of the original +single degree Freedom + + align:start position:0% +single degree Freedom + + + align:start position:0% +single degree Freedom +system so this is the original system + + align:start position:0% +system so this is the original system + + + align:start position:0% +system so this is the original system +K1 M1 and it has that natural frequency + + align:start position:0% +K1 M1 and it has that natural frequency + + + align:start position:0% +K1 M1 and it has that natural frequency +and now I'm going to stick on a second + + align:start position:0% +and now I'm going to stick on a second + + + align:start position:0% +and now I'm going to stick on a second +Mass K2 M2 but the value of K2 over M2 + + align:start position:0% +Mass K2 M2 but the value of K2 over M2 + + + align:start position:0% +Mass K2 M2 but the value of K2 over M2 +of the second little system by itself it + + align:start position:0% +of the second little system by itself it + + + align:start position:0% +of the second little system by itself it +has the same natural frequency as the + + align:start position:0% +has the same natural frequency as the + + + align:start position:0% +has the same natural frequency as the +first if you want to think of it that + + align:start position:0% +first if you want to think of it that + + + align:start position:0% +first if you want to think of it that +way if I make this fixed what's the + + align:start position:0% +way if I make this fixed what's the + + + align:start position:0% +way if I make this fixed what's the +natural frequency of that mass and + + align:start position:0% +natural frequency of that mass and + + + align:start position:0% +natural frequency of that mass and +spring same same natural frequency I'm + + align:start position:0% +spring same same natural frequency I'm + + + align:start position:0% +spring same same natural frequency I'm +just making it that way so this is now + + align:start position:0% +just making it that way so this is now + + + align:start position:0% +just making it that way so this is now +my system that's the that's the that's + + align:start position:0% +my system that's the that's the that's + + + align:start position:0% +my system that's the that's the that's +the parameters and now we can + + align:start position:0% +the parameters and now we can + + + align:start position:0% +the parameters and now we can +uh we can I'm going to plot give you a + + align:start position:0% +uh we can I'm going to plot give you a + + + align:start position:0% +uh we can I'm going to plot give you a +plot of the response of that particular + + align:start position:0% + + + + align:start position:0% + +system + + align:start position:0% + + + + align:start position:0% + +okay I'm going you know how we + + align:start position:0% +okay I'm going you know how we + + + align:start position:0% +okay I'm going you know how we +non-dimensionalize the transfer the + + align:start position:0% +non-dimensionalize the transfer the + + + align:start position:0% +non-dimensionalize the transfer the +single degree of Freedom transfer + + align:start position:0% +single degree of Freedom transfer + + + align:start position:0% +single degree of Freedom transfer +function we said X divided by the static + + align:start position:0% +function we said X divided by the static + + + align:start position:0% +function we said X divided by the static +motion I want to do that again here so + + align:start position:0% +motion I want to do that again here so + + + align:start position:0% +motion I want to do that again here so +let's let's look at this + + align:start position:0% +let's let's look at this + + + align:start position:0% +let's let's look at this +system it's a two degree Freedom + + align:start position:0% +system it's a two degree Freedom + + + align:start position:0% +system it's a two degree Freedom +system has a force F1 on + + align:start position:0% +system has a force F1 on + + + align:start position:0% +system has a force F1 on +it and as the frequency goes to zero and + + align:start position:0% +it and as the frequency goes to zero and + + + align:start position:0% +it and as the frequency goes to zero and +has displacement X1 and X2 so at Omega = + + align:start position:0% +has displacement X1 and X2 so at Omega = + + + align:start position:0% +has displacement X1 and X2 so at Omega = +0 X1 = X1 s I'll call it X1 static and + + align:start position:0% +0 X1 = X1 s I'll call it X1 static and + + + align:start position:0% +0 X1 = X1 s I'll call it X1 static and +how much is + + align:start position:0% +how much is + + + align:start position:0% +how much is +it so what's the static displacement at + + align:start position:0% +it so what's the static displacement at + + + align:start position:0% +it so what's the static displacement at +zero frequency of this system to that + + align:start position:0% + + + + align:start position:0% + +Force come on it's just a spring in a m + + align:start position:0% +Force come on it's just a spring in a m + + + align:start position:0% +Force come on it's just a spring in a m +just a spring in a + + align:start position:0% +just a spring in a + + + align:start position:0% +just a spring in a +force how much will that string spring + + align:start position:0% +force how much will that string spring + + + align:start position:0% +force how much will that string spring +stretch when you put a force F1 on + + align:start position:0% +stretch when you put a force F1 on + + + align:start position:0% +stretch when you put a force F1 on +it F1 over K so X1 static equals F1 over + + align:start position:0% +it F1 over K so X1 static equals F1 over + + + align:start position:0% +it F1 over K so X1 static equals F1 over +K1 and how and F2 is zero there's no F2 + + align:start position:0% +K1 and how and F2 is zero there's no F2 + + + align:start position:0% +K1 and how and F2 is zero there's no F2 +Force so how much is X2 + + align:start position:0% +Force so how much is X2 + + + align:start position:0% +Force so how much is X2 +static there's no forces on F on the + + align:start position:0% +static there's no forces on F on the + + + align:start position:0% +static there's no forces on F on the +second Mass how much will it + + align:start position:0% + + + + align:start position:0% + +move just moves the same amount as the + + align:start position:0% +move just moves the same amount as the + + + align:start position:0% +move just moves the same amount as the +first mass right so this is also this is + + align:start position:0% +first mass right so this is also this is + + + align:start position:0% +first mass right so this is also this is +X2 + + align:start position:0% + + + + align:start position:0% + +static because the forces on the system + + align:start position:0% +static because the forces on the system + + + align:start position:0% +static because the forces on the system +are F1 and zero there's no Force in this + + align:start position:0% +are F1 and zero there's no Force in this + + + align:start position:0% +are F1 and zero there's no Force in this +it's not going to do anything to that + + align:start position:0% +it's not going to do anything to that + + + align:start position:0% +it's not going to do anything to that +spring it'll just move with the whole + + align:start position:0% +spring it'll just move with the whole + + + align:start position:0% +spring it'll just move with the whole +system + + align:start position:0% + + + + align:start position:0% + +okay so I want to plot X1 over X1 + + align:start position:0% +okay so I want to plot X1 over X1 + + + align:start position:0% +okay so I want to plot X1 over X1 +static well X1 is in general X1 is a + + align:start position:0% +static well X1 is in general X1 is a + + + align:start position:0% +static well X1 is in general X1 is a +function of frequency is F1 times and + + align:start position:0% +function of frequency is F1 times and + + + align:start position:0% +function of frequency is F1 times and +I'm going to do the magnitudes here here + + align:start position:0% +I'm going to do the magnitudes here here + + + align:start position:0% +I'm going to do the magnitudes here here +times the magnitude of + + align:start position:0% + + + + align:start position:0% + +h11 and I'm going to divide that + + align:start position:0% +h11 and I'm going to divide that + + + align:start position:0% +h11 and I'm going to divide that +by fub1 + + align:start position:0% +by fub1 + + + align:start position:0% +by fub1 +over K1 so the f1s go away K1 comes in + + align:start position:0% +over K1 so the f1s go away K1 comes in + + + align:start position:0% +over K1 so the f1s go away K1 comes in +the numerator this looks like K1 + + align:start position:0% +the numerator this looks like K1 + + + align:start position:0% +the numerator this looks like K1 +H1 + + align:start position:0% +H1 + + + align:start position:0% +H1 +one so a + + align:start position:0% +one so a + + + align:start position:0% +one so a +plot + + align:start position:0% + + + + align:start position:0% + +of K1 + + align:start position:0% +of K1 + + + align:start position:0% +of K1 +magnitude + + align:start position:0% +magnitude + + + align:start position:0% +magnitude +h11 we know what roughly what it's going + + align:start position:0% +h11 we know what roughly what it's going + + + align:start position:0% +h11 we know what roughly what it's going +to look + + align:start position:0% +to look + + + align:start position:0% +to look +like as a + + align:start position:0% +like as a + + + align:start position:0% +like as a +peak has a + + align:start position:0% +peak has a + + + align:start position:0% +peak has a +zero another + + align:start position:0% + + + + align:start position:0% + +Peak over here this plot goes to one as + + align:start position:0% +Peak over here this plot goes to one as + + + align:start position:0% +Peak over here this plot goes to one as +X1 over this is also X1 over X1 static + + align:start position:0% +X1 over this is also X1 over X1 static + + + align:start position:0% +X1 over this is also X1 over X1 static +same thing it goes to one + + align:start position:0% +same thing it goes to one + + + align:start position:0% +same thing it goes to one +here it goes to + + align:start position:0% +here it goes to + + + align:start position:0% +here it goes to +zero here is Omega + + align:start position:0% +zero here is Omega + + + align:start position:0% +zero here is Omega +1 here's Omega + + align:start position:0% +1 here's Omega + + + align:start position:0% +1 here's Omega +2 and right here you're at the original + + align:start position:0% +2 and right here you're at the original + + + align:start position:0% +2 and right here you're at the original +cap Omega + + align:start position:0% +cap Omega + + + align:start position:0% +cap Omega +n because that's the way we've designed + + align:start position:0% +n because that's the way we've designed + + + align:start position:0% +n because that's the way we've designed +this thing and we know this is the way + + align:start position:0% +this thing and we know this is the way + + + align:start position:0% +this thing and we know this is the way +h11 behaves it goes to zero at the value + + align:start position:0% +h11 behaves it goes to zero at the value + + + align:start position:0% +h11 behaves it goes to zero at the value +we've chosen for square root of K2 over + + align:start position:0% +we've chosen for square root of K2 over + + + align:start position:0% +we've chosen for square root of K2 over +M2 so we started out with an original + + align:start position:0% +M2 so we started out with an original + + + align:start position:0% +M2 so we started out with an original +system that had a natural frequency here + + align:start position:0% +system that had a natural frequency here + + + align:start position:0% +system that had a natural frequency here +okay one over M1 was right here we stuck + + align:start position:0% +okay one over M1 was right here we stuck + + + align:start position:0% +okay one over M1 was right here we stuck +on this second little + + align:start position:0% +on this second little + + + align:start position:0% +on this second little +mass and it made it into a two degree + + align:start position:0% +mass and it made it into a two degree + + + align:start position:0% +mass and it made it into a two degree +Freedom system it no longer has a + + align:start position:0% +Freedom system it no longer has a + + + align:start position:0% +Freedom system it no longer has a +natural frequency there has a natural + + align:start position:0% +natural frequency there has a natural + + + align:start position:0% +natural frequency there has a natural +frequency below it and a natural + + align:start position:0% +frequency below it and a natural + + + align:start position:0% +frequency below it and a natural +frequency above it and it's zero right + + align:start position:0% +frequency above it and it's zero right + + + align:start position:0% +frequency above it and it's zero right +where the original natural frequency + + align:start position:0% + + + + align:start position:0% + +was okay now the uh + + align:start position:0% +was okay now the uh + + + align:start position:0% +was okay now the uh +so you've got imagine what's going on in + + align:start position:0% +so you've got imagine what's going on in + + + align:start position:0% +so you've got imagine what's going on in +the system you've got this Force being + + align:start position:0% +the system you've got this Force being + + + align:start position:0% +the system you've got this Force being +applied to the first mass and the first + + align:start position:0% +applied to the first mass and the first + + + align:start position:0% +applied to the first mass and the first +mass isn't + + align:start position:0% +mass isn't + + + align:start position:0% +mass isn't +moving do you think the second mass is + + align:start position:0% + + + + align:start position:0% + +moving think about the free body diagram + + align:start position:0% +moving think about the free body diagram + + + align:start position:0% +moving think about the free body diagram +of the first mass f equals + + align:start position:0% +of the first mass f equals + + + align:start position:0% +of the first mass f equals +ma there's a force on that first mass F1 + + align:start position:0% +ma there's a force on that first mass F1 + + + align:start position:0% +ma there's a force on that first mass F1 +cosine Omega T and it's not moving MX + + align:start position:0% +cosine Omega T and it's not moving MX + + + align:start position:0% +cosine Omega T and it's not moving MX +double mx1 double dot is + + align:start position:0% +double mx1 double dot is + + + align:start position:0% +double mx1 double dot is +zero so in order for the thing not to + + align:start position:0% +zero so in order for the thing not to + + + align:start position:0% +zero so in order for the thing not to +move there's a force on it there must be + + align:start position:0% +move there's a force on it there must be + + + align:start position:0% +move there's a force on it there must be +some other Force exactly canceling + + align:start position:0% +some other Force exactly canceling + + + align:start position:0% +some other Force exactly canceling +it right where's it come + + align:start position:0% +it right where's it come + + + align:start position:0% +it right where's it come +from Mass 2 through the spring right + + align:start position:0% +from Mass 2 through the spring right + + + align:start position:0% +from Mass 2 through the spring right +okay so I'd also like to know uh what's + + align:start position:0% +okay so I'd also like to know uh what's + + + align:start position:0% +okay so I'd also like to know uh what's +the mo what is + + align:start position:0% + + + + align:start position:0% + +X2 well + + align:start position:0% +X2 well + + + align:start position:0% +X2 well +X2 is from our transfer function Matrix + + align:start position:0% +X2 is from our transfer function Matrix + + + align:start position:0% +X2 is from our transfer function Matrix +is the response of two + + align:start position:0% +is the response of two + + + align:start position:0% +is the response of two +due to a force at 1 * fub1 plus a + + align:start position:0% +due to a force at 1 * fub1 plus a + + + align:start position:0% +due to a force at 1 * fub1 plus a +response at two due to a force at 2 * F2 + + align:start position:0% +response at two due to a force at 2 * F2 + + + align:start position:0% +response at two due to a force at 2 * F2 +but that second term is zero because F2 + + align:start position:0% +but that second term is zero because F2 + + + align:start position:0% +but that second term is zero because F2 +is + + align:start position:0% +is + + + align:start position:0% +is +zero that's a one- term + + align:start position:0% +zero that's a one- term + + + align:start position:0% +zero that's a one- term +expression and H1 + + align:start position:0% + + + + align:start position:0% + +h21 + + align:start position:0% +h21 + + + align:start position:0% +h21 +is z11 over the denominator and z11 + + align:start position:0% + + + + align:start position:0% + +so X2 is going to look like that + + align:start position:0% + + + + align:start position:0% + +I did wrote that + + align:start position:0% +I did wrote that + + + align:start position:0% +I did wrote that +wrong this is not + + align:start position:0% +wrong this is not + + + align:start position:0% +wrong this is not +z11 it is z minus z12 + + align:start position:0% +z11 it is z minus z12 + + + align:start position:0% +z11 it is z minus z12 +right like + + align:start position:0% + + + + align:start position:0% + +that and if you work that out it's + + align:start position:0% +that and if you work that out it's + + + align:start position:0% +that and if you work that out it's +fub1 time + + align:start position:0% +fub1 time + + + align:start position:0% +fub1 time +K2 + + align:start position:0% +K2 + + + align:start position:0% +K2 +over the same denominator + + align:start position:0% +over the same denominator + + + align:start position:0% +over the same denominator +but let's evaluate i' let let's evaluate + + align:start position:0% +but let's evaluate i' let let's evaluate + + + align:start position:0% +but let's evaluate i' let let's evaluate +here's our this is a frequency we've + + align:start position:0% +here's our this is a frequency we've + + + align:start position:0% +here's our this is a frequency we've +been interested in let's evaluate the + + align:start position:0% +been interested in let's evaluate the + + + align:start position:0% +been interested in let's evaluate the +response of + + align:start position:0% +response of + + + align:start position:0% +response of +X2 right at this operating + + align:start position:0% +X2 right at this operating + + + align:start position:0% +X2 right at this operating +point so this's evaluate this at Omega + + align:start position:0% +point so this's evaluate this at Omega + + + align:start position:0% +point so this's evaluate this at Omega +equals cap Omega + + align:start position:0% +equals cap Omega + + + align:start position:0% +equals cap Omega +n okay so that's + + align:start position:0% +n okay so that's + + + align:start position:0% +n okay so that's +K2 down + + align:start position:0% +K2 down + + + align:start position:0% +K2 down +here minus Omega SAR M1 + + align:start position:0% +here minus Omega SAR M1 + + + align:start position:0% +here minus Omega SAR M1 +1 + K1 + K2 it's the same denominator as + + align:start position:0% + + + + align:start position:0% + +always + + align:start position:0% + + + + align:start position:0% + +K2 I'm not going to write it all out + + align:start position:0% +K2 I'm not going to write it all out + + + align:start position:0% +K2 I'm not going to write it all out +it's exactly the same thing as before + + align:start position:0% +it's exactly the same thing as before + + + align:start position:0% +it's exactly the same thing as before +but I want to plug in to this + + align:start position:0% +but I want to plug in to this + + + align:start position:0% +but I want to plug in to this +denominator the operating + + align:start position:0% +denominator the operating + + + align:start position:0% +denominator the operating +frequency you know we're going to + + align:start position:0% +frequency you know we're going to + + + align:start position:0% +frequency you know we're going to +operate at cap Omega n which is k1 over + + align:start position:0% +operate at cap Omega n which is k1 over + + + align:start position:0% +operate at cap Omega n which is k1 over +M1 square square otk of K1 over M1 or + + align:start position:0% +M1 square square otk of K1 over M1 or + + + align:start position:0% +M1 square square otk of K1 over M1 or +Square otk of K2 over M2 I'm going to + + align:start position:0% +Square otk of K2 over M2 I'm going to + + + align:start position:0% +Square otk of K2 over M2 I'm going to +plug in in this and let's see what we + + align:start position:0% +plug in in this and let's see what we + + + align:start position:0% +plug in in this and let's see what we +get + + align:start position:0% + + + + align:start position:0% + +and I'm going to eval + + align:start position:0% +and I'm going to eval + + + align:start position:0% +and I'm going to eval +let Omega + + align:start position:0% +let Omega + + + align:start position:0% +let Omega +equal + + align:start position:0% +equal + + + align:start position:0% +equal +K1 over M1 or K2 over M2 it's the same + + align:start position:0% +K1 over M1 or K2 over M2 it's the same + + + align:start position:0% +K1 over M1 or K2 over M2 it's the same +thing I going to plug them in whatever + + align:start position:0% +thing I going to plug them in whatever + + + align:start position:0% +thing I going to plug them in whatever +is convenient so here I'm going to put + + align:start position:0% +is convenient so here I'm going to put + + + align:start position:0% +is convenient so here I'm going to put +K1 over + + align:start position:0% +K1 over + + + align:start position:0% +K1 over +M1 and the m1's are going to cancel I'll + + align:start position:0% +M1 and the m1's are going to cancel I'll + + + align:start position:0% +M1 and the m1's are going to cancel I'll +be left with a + + align:start position:0% + + + + align:start position:0% + +K1 F1 over K2 and down in denominator + + align:start position:0% +K1 F1 over K2 and down in denominator + + + align:start position:0% +K1 F1 over K2 and down in denominator +this is this term turns into K1 over M1 + + align:start position:0% +this is this term turns into K1 over M1 + + + align:start position:0% +this is this term turns into K1 over M1 +so that's minus K1 + K1 plus + + align:start position:0% +so that's minus K1 + K1 plus + + + align:start position:0% +so that's minus K1 + K1 plus +K2 those two cancel I just get a K2 over + + align:start position:0% +K2 those two cancel I just get a K2 over + + + align:start position:0% +K2 those two cancel I just get a K2 over +here I'll use minus K2 over + + align:start position:0% +here I'll use minus K2 over + + + align:start position:0% +here I'll use minus K2 over +M2 * M2 + + + align:start position:0% +M2 * M2 + + + + align:start position:0% +M2 * M2 + +K2 and that gives me a minus K2 plus K2 + + align:start position:0% +K2 and that gives me a minus K2 plus K2 + + + align:start position:0% +K2 and that gives me a minus K2 plus K2 +ooh this whole thing goes to + + align:start position:0% +ooh this whole thing goes to + + + align:start position:0% +ooh this whole thing goes to +zero and I'm left with + + align:start position:0% +zero and I'm left with + + + align:start position:0% +zero and I'm left with +minus K2 2ar and in the denominator a + + align:start position:0% +minus K2 2ar and in the denominator a + + + align:start position:0% +minus K2 2ar and in the denominator a +K2 this whole thing turns into fub1 over + + align:start position:0% + + + + align:start position:0% + +K2 so the total response of that second + + align:start position:0% +K2 so the total response of that second + + + align:start position:0% +K2 so the total response of that second +mass at this operating frequency is just + + align:start position:0% +mass at this operating frequency is just + + + align:start position:0% +mass at this operating frequency is just +F1 over + + align:start position:0% +F1 over + + + align:start position:0% +F1 over +K2 and I would like to plot it as what + + align:start position:0% +K2 and I would like to plot it as what + + + align:start position:0% +K2 and I would like to plot it as what +does + + align:start position:0% + + + + align:start position:0% + +X2 + + align:start position:0% +X2 + + + align:start position:0% +X2 +over + + align:start position:0% +over + + + align:start position:0% +over +X One static and X1 static and and X2 + + align:start position:0% +X One static and X1 static and and X2 + + + align:start position:0% +X One static and X1 static and and X2 +static are the + + align:start position:0% + + + + align:start position:0% + +same well that + + align:start position:0% + + + + align:start position:0% + +is fub1 over + + align:start position:0% +is fub1 over + + + align:start position:0% +is fub1 over +K2 over fub1 over + + align:start position:0% +K2 over fub1 over + + + align:start position:0% +K2 over fub1 over +K1 the f1s go away and I get K1 over K2 + + align:start position:0% +K1 the f1s go away and I get K1 over K2 + + + align:start position:0% +K1 the f1s go away and I get K1 over K2 +that also happens to be M1 over M2 and + + align:start position:0% +that also happens to be M1 over M2 and + + + align:start position:0% +that also happens to be M1 over M2 and +it's a quantity we call one over + + align:start position:0% +it's a quantity we call one over + + + align:start position:0% +it's a quantity we call one over +mu and this we have just + + align:start position:0% +mu and this we have just + + + align:start position:0% +mu and this we have just +designed what's called a dynamic + + align:start position:0% +designed what's called a dynamic + + + align:start position:0% +designed what's called a dynamic +absorber and a dynamic absorber is a + + align:start position:0% +absorber and a dynamic absorber is a + + + align:start position:0% +absorber and a dynamic absorber is a +little we little device you can use to + + align:start position:0% +little we little device you can use to + + + align:start position:0% +little we little device you can use to +stop + + align:start position:0% +stop + + + align:start position:0% +stop +vibration so when we were talking about + + align:start position:0% +vibration so when we were talking about + + + align:start position:0% +vibration so when we were talking about +vibration isolation and vibration + + align:start position:0% +vibration isolation and vibration + + + align:start position:0% +vibration isolation and vibration +mitigation a few days ago and I said + + align:start position:0% +mitigation a few days ago and I said + + + align:start position:0% +mitigation a few days ago and I said +you've got some rotating imbalance + + align:start position:0% +you've got some rotating imbalance + + + align:start position:0% +you've got some rotating imbalance +causing your something to shake will + + align:start position:0% +causing your something to shake will + + + align:start position:0% +causing your something to shake will +give me three ways of solving it he said + + align:start position:0% +give me three ways of solving it he said + + + align:start position:0% +give me three ways of solving it he said +balance the rotor what were the other + + align:start position:0% +balance the rotor what were the other + + + align:start position:0% +balance the rotor what were the other +two ways of perhaps reducing the + + align:start position:0% + + + + align:start position:0% + +vibration + + align:start position:0% +vibration + + + align:start position:0% +vibration +pardon yeah but we also you know if you + + align:start position:0% +pardon yeah but we also you know if you + + + align:start position:0% +pardon yeah but we also you know if you +got something that's shaking like crazy + + align:start position:0% +got something that's shaking like crazy + + + align:start position:0% +got something that's shaking like crazy +and it's putting vibration into the + + align:start position:0% +and it's putting vibration into the + + + align:start position:0% +and it's putting vibration into the +floor or into the the table you can + + align:start position:0% +floor or into the the table you can + + + align:start position:0% +floor or into the the table you can +isolate it with a mass and a spring or + + align:start position:0% +isolate it with a mass and a spring or + + + align:start position:0% +isolate it with a mass and a spring or +the microscope over here that's + + align:start position:0% +the microscope over here that's + + + align:start position:0% +the microscope over here that's +vibrating like crazy you can isolate it + + align:start position:0% +vibrating like crazy you can isolate it + + + align:start position:0% +vibrating like crazy you can isolate it +with a mass or a spring so this is this + + align:start position:0% +with a mass or a spring so this is this + + + align:start position:0% +with a mass or a spring so this is this +topic of vibration isolation which is + + align:start position:0% +topic of vibration isolation which is + + + align:start position:0% +topic of vibration isolation which is +guaranteed to be on the + + align:start position:0% +guaranteed to be on the + + + align:start position:0% +guaranteed to be on the +final simple practical applications of + + align:start position:0% +final simple practical applications of + + + align:start position:0% +final simple practical applications of +single degre Freedom stuff so have three + + align:start position:0% +single degre Freedom stuff so have three + + + align:start position:0% +single degre Freedom stuff so have three +ways fix the rotor isolate it with a + + align:start position:0% +ways fix the rotor isolate it with a + + + align:start position:0% +ways fix the rotor isolate it with a +mass in a spring isolate the sensitive + + align:start position:0% +mass in a spring isolate the sensitive + + + align:start position:0% +mass in a spring isolate the sensitive +instrument mass of the spring now you + + align:start position:0% +instrument mass of the spring now you + + + align:start position:0% +instrument mass of the spring now you +have a fourth way if it's a particular + + align:start position:0% +have a fourth way if it's a particular + + + align:start position:0% +have a fourth way if it's a particular +operating frequency we can make it + + align:start position:0% +operating frequency we can make it + + + align:start position:0% +operating frequency we can make it +operate right here with this thing + + align:start position:0% +operate right here with this thing + + + align:start position:0% +operate right here with this thing +called the dynamic absorber this mu + + align:start position:0% +called the dynamic absorber this mu + + + align:start position:0% +called the dynamic absorber this mu +quantity is called the mass + + align:start position:0% + + + + align:start position:0% + +ratio and + + align:start position:0% +ratio and + + + align:start position:0% +ratio and +um that's M it's it's M2 over + + align:start position:0% +um that's M it's it's M2 over + + + align:start position:0% +um that's M it's it's M2 over +M1 basically these things are real + + align:start position:0% +M1 basically these things are real + + + align:start position:0% +M1 basically these things are real +they're actually used in real machines + + align:start position:0% +they're actually used in real machines + + + align:start position:0% +they're actually used in real machines +and usually you can't the this Dynamic + + align:start position:0% +and usually you can't the this Dynamic + + + align:start position:0% +and usually you can't the this Dynamic +resor thing you stick on there can't be + + align:start position:0% +resor thing you stick on there can't be + + + align:start position:0% +resor thing you stick on there can't be +as big as the original system it's going + + align:start position:0% +as big as the original system it's going + + + align:start position:0% +as big as the original system it's going +to be some small fraction the original + + align:start position:0% +to be some small fraction the original + + + align:start position:0% +to be some small fraction the original +system size five or 10% if you're lucky + + align:start position:0% +system size five or 10% if you're lucky + + + align:start position:0% +system size five or 10% if you're lucky +so the bigger this thing is you'll find + + align:start position:0% +so the bigger this thing is you'll find + + + align:start position:0% +so the bigger this thing is you'll find +out the better it works so what's how + + align:start position:0% +out the better it works so what's how + + + align:start position:0% +out the better it works so what's how +how how much is this little second Mass + + align:start position:0% +how how much is this little second Mass + + + align:start position:0% +how how much is this little second Mass +bouncing around well it's bouncing + + align:start position:0% +bouncing around well it's bouncing + + + align:start position:0% +bouncing around well it's bouncing +around compared to X1 static in the + + align:start position:0% +around compared to X1 static in the + + + align:start position:0% +around compared to X1 static in the +ratio of K1 to K2 which is this one over + + align:start position:0% +ratio of K1 to K2 which is this one over + + + align:start position:0% +ratio of K1 to K2 which is this one over +mu quantity so if mu is 10% if you've + + align:start position:0% +mu quantity so if mu is 10% if you've + + + align:start position:0% +mu quantity so if mu is 10% if you've +added the second mass is 10% the size of + + align:start position:0% +added the second mass is 10% the size of + + + align:start position:0% +added the second mass is 10% the size of +the first one one over mu is a factor of + + align:start position:0% +the first one one over mu is a factor of + + + align:start position:0% +the first one one over mu is a factor of +10 Okay so the this transfer function + + align:start position:0% +10 Okay so the this transfer function + + + align:start position:0% +10 Okay so the this transfer function +basically looks do I have something + + align:start position:0% + + + + align:start position:0% + +colored so the X2 over X1 transfer + + align:start position:0% +colored so the X2 over X1 transfer + + + align:start position:0% +colored so the X2 over X1 transfer +function basically behaves the same way + + align:start position:0% +function basically behaves the same way + + + align:start position:0% +function basically behaves the same way +here and pretty much the same way out + + align:start position:0% +here and pretty much the same way out + + + align:start position:0% +here and pretty much the same way out +here and in here comes down like this + + align:start position:0% +here and in here comes down like this + + + align:start position:0% +here and in here comes down like this +and comes back up and this height right + + align:start position:0% +and comes back up and this height right + + + align:start position:0% +and comes back up and this height right +right + + align:start position:0% +right + + + align:start position:0% +right +here is 1 over + + align:start position:0% +here is 1 over + + + align:start position:0% +here is 1 over +mu so the smaller you make this thing + + align:start position:0% +mu so the smaller you make this thing + + + align:start position:0% +mu so the smaller you make this thing +the tinier you make it the more it has + + align:start position:0% +the tinier you make it the more it has + + + align:start position:0% +the tinier you make it the more it has +to + + align:start position:0% +to + + + align:start position:0% +to +shake to force the first mass to go to + + align:start position:0% +shake to force the first mass to go to + + + align:start position:0% +shake to force the first mass to go to +zero and so basically the way reason + + align:start position:0% +zero and so basically the way reason + + + align:start position:0% +zero and so basically the way reason +this thing works the free body diagram + + align:start position:0% +this thing works the free body diagram + + + align:start position:0% +this thing works the free body diagram +on the + + align:start position:0% +on the + + + align:start position:0% +on the +uh at this oper at this zero point the + + align:start position:0% +uh at this oper at this zero point the + + + align:start position:0% +uh at this oper at this zero point the +main Mass + + align:start position:0% +main Mass + + + align:start position:0% +main Mass +M1 X1 equals z here it's not moving it's + + align:start position:0% +M1 X1 equals z here it's not moving it's + + + align:start position:0% +M1 X1 equals z here it's not moving it's +got a force acting on it that is some + + align:start position:0% +got a force acting on it that is some + + + align:start position:0% +got a force acting on it that is some +fub1 cosine Omega T it's got a spring + + align:start position:0% +fub1 cosine Omega T it's got a spring + + + align:start position:0% +fub1 cosine Omega T it's got a spring +force acting on it from this second Mass + + align:start position:0% +force acting on it from this second Mass + + + align:start position:0% +force acting on it from this second Mass +going here's M2 over here and it's going + + align:start position:0% +going here's M2 over here and it's going + + + align:start position:0% +going here's M2 over here and it's going +back and forth like + + align:start position:0% +back and forth like + + + align:start position:0% +back and forth like +crazy putting Force through this spring + + align:start position:0% +crazy putting Force through this spring + + + align:start position:0% +crazy putting Force through this spring +and the spring Force had better be + + align:start position:0% +and the spring Force had better be + + + align:start position:0% +and the spring Force had better be +exactly equal to + + align:start position:0% +exactly equal to + + + align:start position:0% +exactly equal to +that so the F spring is going to be + + align:start position:0% +that so the F spring is going to be + + + align:start position:0% +that so the F spring is going to be +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +minus + + align:start position:0% +minus + + + align:start position:0% +minus +fub1 and that will be equal to X2 * + + align:start position:0% +fub1 and that will be equal to X2 * + + + align:start position:0% +fub1 and that will be equal to X2 * +kx2 this the second Mass has to move + + align:start position:0% +kx2 this the second Mass has to move + + + align:start position:0% +kx2 this the second Mass has to move +enough that it'll compress the spring + + align:start position:0% +enough that it'll compress the spring + + + align:start position:0% +enough that it'll compress the spring +enough that it's provides a force equal + + align:start position:0% +enough that it's provides a force equal + + + align:start position:0% +enough that it's provides a force equal +and opposite to this one so that it's in + + align:start position:0% +and opposite to this one so that it's in + + + align:start position:0% +and opposite to this one so that it's in +stat it's in equilibrium and doesn't + + align:start position:0% +stat it's in equilibrium and doesn't + + + align:start position:0% +stat it's in equilibrium and doesn't +move all + + align:start position:0% +move all + + + align:start position:0% +move all +right yeah + + align:start position:0% + + + + align:start position:0% + +that who asking a question yeah so the + + align:start position:0% +that who asking a question yeah so the + + + align:start position:0% +that who asking a question yeah so the +building um if you want the masses to be + + align:start position:0% +building um if you want the masses to be + + + align:start position:0% +building um if you want the masses to be +fairly equal to each other how's going + + align:start position:0% +fairly equal to each other how's going + + + align:start position:0% +fairly equal to each other how's going +to happen no so I mean not usually in + + align:start position:0% +to happen no so I mean not usually in + + + align:start position:0% +to happen no so I mean not usually in +real when people when Dynam Dynamic + + align:start position:0% +real when people when Dynam Dynamic + + + align:start position:0% +real when people when Dynam Dynamic +absorbers are are used in real things + + align:start position:0% +absorbers are are used in real things + + + align:start position:0% +absorbers are are used in real things +like the Handcock building and they're + + align:start position:0% +like the Handcock building and they're + + + align:start position:0% +like the Handcock building and they're +used in + + align:start position:0% +used in + + + align:start position:0% +used in +engines they're used in all sorts of + + align:start position:0% +engines they're used in all sorts of + + + align:start position:0% +engines they're used in all sorts of +little devices that you don't know where + + align:start position:0% +little devices that you don't know where + + + align:start position:0% +little devices that you don't know where +that they're there + + align:start position:0% +that they're there + + + align:start position:0% +that they're there +um and and you have to usually hide them + + align:start position:0% +um and and you have to usually hide them + + + align:start position:0% +um and and you have to usually hide them +inside the footprint of the original + + align:start position:0% +inside the footprint of the original + + + align:start position:0% +inside the footprint of the original +device so you don't want them you know + + align:start position:0% +device so you don't want them you know + + + align:start position:0% +device so you don't want them you know +for a real thing you don't want to have + + align:start position:0% +for a real thing you don't want to have + + + align:start position:0% +for a real thing you don't want to have +a pump you know with this huge appendage + + align:start position:0% +a pump you know with this huge appendage + + + align:start position:0% +a pump you know with this huge appendage +on it right it's just not practical so + + align:start position:0% +on it right it's just not practical so + + + align:start position:0% +on it right it's just not practical so +they tend to be small and so they as a + + align:start position:0% +they tend to be small and so they as a + + + align:start position:0% +they tend to be small and so they as a +consequence in order to make them work + + align:start position:0% +consequence in order to make them work + + + align:start position:0% +consequence in order to make them work +at this particular frequency they have + + align:start position:0% +at this particular frequency they have + + + align:start position:0% +at this particular frequency they have +to vibrate like crazy so the design cost + + align:start position:0% +to vibrate like crazy so the design cost + + + align:start position:0% +to vibrate like crazy so the design cost +of one of these things is you have to + + align:start position:0% +of one of these things is you have to + + + align:start position:0% +of one of these things is you have to +design it to be able to allow this + + align:start position:0% +design it to be able to allow this + + + align:start position:0% +design it to be able to allow this +second Mass to shake like I'll get out + + align:start position:0% +second Mass to shake like I'll get out + + + align:start position:0% +second Mass to shake like I'll get out +now how many frequenc quencies does this + + align:start position:0% +now how many frequenc quencies does this + + + align:start position:0% +now how many frequenc quencies does this +work + + align:start position:0% +work + + + align:start position:0% +work +at once you've designed it it only works + + align:start position:0% +at once you've designed it it only works + + + align:start position:0% +at once you've designed it it only works +at one frequency so this is only useful + + align:start position:0% +at one frequency so this is only useful + + + align:start position:0% +at one frequency so this is only useful +for something it has a a fixed operating + + align:start position:0% +for something it has a a fixed operating + + + align:start position:0% +for something it has a a fixed operating +frequency like a synchronous motor you + + align:start position:0% +frequency like a synchronous motor you + + + align:start position:0% +frequency like a synchronous motor you +won't this isn't a good good thing for + + align:start position:0% +won't this isn't a good good thing for + + + align:start position:0% +won't this isn't a good good thing for +something that has uh a range of + + align:start position:0% +something that has uh a range of + + + align:start position:0% +something that has uh a range of +frequencies over which it can work but + + align:start position:0% +frequencies over which it can work but + + + align:start position:0% +frequencies over which it can work but +there's a different more complicated + + align:start position:0% +there's a different more complicated + + + align:start position:0% +there's a different more complicated +Theory call of that there's a type of + + align:start position:0% +Theory call of that there's a type of + + + align:start position:0% +Theory call of that there's a type of +dynamic absorber that you can make work + + align:start position:0% +dynamic absorber that you can make work + + + align:start position:0% +dynamic absorber that you can make work +over a wide range of frequencies need to + + align:start position:0% +over a wide range of frequencies need to + + + align:start position:0% +over a wide range of frequencies need to +tell you one other thing when we put + + align:start position:0% +tell you one other thing when we put + + + align:start position:0% +tell you one other thing when we put +this thing on the original natural + + align:start position:0% +this thing on the original natural + + + align:start position:0% +this thing on the original natural +frequency of the first system was here + + align:start position:0% +frequency of the first system was here + + + align:start position:0% +frequency of the first system was here +and it created two new ones right you + + align:start position:0% +and it created two new ones right you + + + align:start position:0% +and it created two new ones right you +got a further + + align:start position:0% +got a further + + + align:start position:0% +got a further +question so how is making a VI vibrant + + align:start position:0% +question so how is making a VI vibrant + + + align:start position:0% +question so how is making a VI vibrant +like bad Health it's only going to work + + align:start position:0% +like bad Health it's only going to work + + + align:start position:0% +like bad Health it's only going to work +at that one frequency and you're always + + align:start position:0% +at that one frequency and you're always + + + align:start position:0% +at that one frequency and you're always +going to have that Gap so making you + + align:start position:0% +going to have that Gap so making you + + + align:start position:0% +going to have that Gap so making you +Library really fast how how would that + + align:start position:0% +Library really fast how how would that + + + align:start position:0% +Library really fast how how would that +help at all well it stops if the if for + + align:start position:0% +help at all well it stops if the if for + + + align:start position:0% +help at all well it stops if the if for +some reason you really don't want that + + align:start position:0% +some reason you really don't want that + + + align:start position:0% +some reason you really don't want that +first thing to shake this makes it stop + + align:start position:0% +first thing to shake this makes it stop + + + align:start position:0% +first thing to shake this makes it stop +shaking at that + + align:start position:0% +shaking at that + + + align:start position:0% +shaking at that +frequency so for example Le there's an + + align:start position:0% +frequency so for example Le there's an + + + align:start position:0% +frequency so for example Le there's an +one of the first one of the widest + + align:start position:0% +one of the first one of the widest + + + align:start position:0% +one of the first one of the widest +distributed textbooks in the world was + + align:start position:0% +distributed textbooks in the world was + + + align:start position:0% +distributed textbooks in the world was +written by an MIT Professor named den + + align:start position:0% +written by an MIT Professor named den + + + align:start position:0% +written by an MIT Professor named den +harthog and it's called mechanical + + align:start position:0% +harthog and it's called mechanical + + + align:start position:0% +harthog and it's called mechanical +vibration written in the 1930s it's got + + align:start position:0% +vibration written in the 1930s it's got + + + align:start position:0% +vibration written in the 1930s it's got +a wonderful chapter on Dynamic absorbers + + align:start position:0% +a wonderful chapter on Dynamic absorbers + + + align:start position:0% +a wonderful chapter on Dynamic absorbers +in it and the example that he gives of a + + align:start position:0% +in it and the example that he gives of a + + + align:start position:0% +in it and the example that he gives of a +real device that actually uses one was + + align:start position:0% +real device that actually uses one was + + + align:start position:0% +real device that actually uses one was +the kind was an electric uh hair clipper + + align:start position:0% +the kind was an electric uh hair clipper + + + align:start position:0% +the kind was an electric uh hair clipper +that you know barara uses now you know + + align:start position:0% +that you know barara uses now you know + + + align:start position:0% +that you know barara uses now you know +the head on a hair clipper it's got it + + align:start position:0% +the head on a hair clipper it's got it + + + align:start position:0% +the head on a hair clipper it's got it +it has to go back and forth like this + + align:start position:0% +it has to go back and forth like this + + + align:start position:0% +it has to go back and forth like this +you know to cut the hair right that is + + align:start position:0% +you know to cut the hair right that is + + + align:start position:0% +you know to cut the hair right that is +an oscillating mass and you're going to + + align:start position:0% +an oscillating mass and you're going to + + + align:start position:0% +an oscillating mass and you're going to +feel it that's an essentially you know + + align:start position:0% +feel it that's an essentially you know + + + align:start position:0% +feel it that's an essentially you know +you're going to feel the mass times the + + align:start position:0% +you're going to feel the mass times the + + + align:start position:0% +you're going to feel the mass times the +acceleration the m a Omega squar + + align:start position:0% +acceleration the m a Omega squar + + + align:start position:0% +acceleration the m a Omega squar +acceleration at the frequency it runs + + align:start position:0% +acceleration at the frequency it runs + + + align:start position:0% +acceleration at the frequency it runs +that so they did a clever thing they + + align:start position:0% +that so they did a clever thing they + + + align:start position:0% +that so they did a clever thing they +built inside the case of this thing a + + align:start position:0% +built inside the case of this thing a + + + align:start position:0% +built inside the case of this thing a +little second mass in a spring and so + + align:start position:0% +little second mass in a spring and so + + + align:start position:0% +little second mass in a spring and so +the when you're holding the razor the + + align:start position:0% +the when you're holding the razor the + + + align:start position:0% +the when you're holding the razor the +Clippers it didn't feel like + + align:start position:0% +Clippers it didn't feel like + + + align:start position:0% +Clippers it didn't feel like +it's okay so that's an ex was an example + + align:start position:0% +it's okay so that's an ex was an example + + + align:start position:0% +it's okay so that's an ex was an example +actually a great example in this 1938 + + align:start position:0% +actually a great example in this 1938 + + + align:start position:0% +actually a great example in this 1938 +textbook okay and you just so you know I + + align:start position:0% +textbook okay and you just so you know I + + + align:start position:0% +textbook okay and you just so you know I +mean you really do have two natural + + align:start position:0% +mean you really do have two natural + + + align:start position:0% +mean you really do have two natural +frequencies when you do this and I'll + + align:start position:0% +frequencies when you do this and I'll + + + align:start position:0% +frequencies when you do this and I'll +write them like this Omega 1^ 2 and + + align:start position:0% +write them like this Omega 1^ 2 and + + + align:start position:0% +write them like this Omega 1^ 2 and +Omega 2^ 2 are the original frequency + + align:start position:0% +Omega 2^ 2 are the original frequency + + + align:start position:0% +Omega 2^ 2 are the original frequency +squared Time 1 + mu / + + align:start position:0% +squared Time 1 + mu / + + + align:start position:0% +squared Time 1 + mu / +2 plus or + + align:start position:0% +2 plus or + + + align:start position:0% +2 plus or +minus mu + mu^ + + align:start position:0% +minus mu + mu^ + + + align:start position:0% +minus mu + mu^ +2 over 4 + + align:start position:0% +2 over 4 + + + align:start position:0% +2 over 4 +square + + align:start position:0% +square + + + align:start position:0% +square +root so as your mass ratio gets + + align:start position:0% +root so as your mass ratio gets + + + align:start position:0% +root so as your mass ratio gets +bigger the two frequencies move further + + align:start position:0% +bigger the two frequencies move further + + + align:start position:0% +bigger the two frequencies move further +and further apart when the mass ratio is + + align:start position:0% +and further apart when the mass ratio is + + + align:start position:0% +and further apart when the mass ratio is +zero this quantity the two natural + + align:start position:0% +zero this quantity the two natural + + + align:start position:0% +zero this quantity the two natural +frequenc the only it goes to one natural + + align:start position:0% +frequenc the only it goes to one natural + + + align:start position:0% +frequenc the only it goes to one natural +frequency it's a single degree Freedom + + align:start position:0% +frequency it's a single degree Freedom + + + align:start position:0% +frequency it's a single degree Freedom +system and it's at the original value as + + align:start position:0% +system and it's at the original value as + + + align:start position:0% +system and it's at the original value as +the mass ratio gets bigger and bigger + + align:start position:0% +the mass ratio gets bigger and bigger + + + align:start position:0% +the mass ratio gets bigger and bigger +these two Roots this one and this + + align:start position:0% +these two Roots this one and this + + + align:start position:0% +these two Roots this one and this +one as you add Mass to that second + + align:start position:0% +one as you add Mass to that second + + + align:start position:0% +one as you add Mass to that second +system they spread apart and the bigger + + align:start position:0% +system they spread apart and the bigger + + + align:start position:0% +system they spread apart and the bigger +the the mass ratio the further apart the + + align:start position:0% +the the mass ratio the further apart the + + + align:start position:0% +the the mass ratio the further apart the +two natural frequencies + + align:start position:0% +two natural frequencies + + + align:start position:0% +two natural frequencies +become so we got 10 minutes left and I + + align:start position:0% +become so we got 10 minutes left and I + + + align:start position:0% +become so we got 10 minutes left and I +have a demo which is illustrates this + + align:start position:0% +have a demo which is illustrates this + + + align:start position:0% +have a demo which is illustrates this +thing it's a little delicate to make it + + align:start position:0% +thing it's a little delicate to make it + + + align:start position:0% +thing it's a little delicate to make it +work so uh because actually it was + + align:start position:0% +work so uh because actually it was + + + align:start position:0% +work so uh because actually it was +really frustrating I had it all set up + + align:start position:0% +really frustrating I had it all set up + + + align:start position:0% +really frustrating I had it all set up +it worked great in my + + align:start position:0% +it worked great in my + + + align:start position:0% +it worked great in my +office came in 10 minutes early today to + + align:start position:0% +office came in 10 minutes early today to + + + align:start position:0% +office came in 10 minutes early today to +set it up and the table in here is so + + align:start position:0% +set it up and the table in here is so + + + align:start position:0% +set it up and the table in here is so +flexible I can't make it behave like a + + align:start position:0% +flexible I can't make it behave like a + + + align:start position:0% +flexible I can't make it behave like a +fixed surface + + align:start position:0% +fixed surface + + + align:start position:0% +fixed surface +so I tweaked it and I think I've got it + + align:start position:0% +so I tweaked it and I think I've got it + + + align:start position:0% +so I tweaked it and I think I've got it +running now but now what what it is is a + + align:start position:0% +running now but now what what it is is a + + + align:start position:0% +running now but now what what it is is a +beam with my pen on it my little + + align:start position:0% +beam with my pen on it my little + + + align:start position:0% +beam with my pen on it my little +squiggle pen and you've seen this before + + align:start position:0% +squiggle pen and you've seen this before + + + align:start position:0% +squiggle pen and you've seen this before +it's it's a rotating Mass it's a static + + align:start position:0% +it's it's a rotating Mass it's a static + + + align:start position:0% +it's it's a rotating Mass it's a static +imbalance it shakes this beam okay and + + align:start position:0% +imbalance it shakes this beam okay and + + + align:start position:0% +imbalance it shakes this beam okay and +I've added to it a second little beam + + align:start position:0% +I've added to it a second little beam + + + align:start position:0% +I've added to it a second little beam +it's a little blade of Steel with a + + align:start position:0% +it's a little blade of Steel with a + + + align:start position:0% +it's a little blade of Steel with a +heavy magnet on it that's my M2 this is + + align:start position:0% +heavy magnet on it that's my M2 this is + + + align:start position:0% +heavy magnet on it that's my M2 this is +my K2 is this little beam this is the + + align:start position:0% +my K2 is this little beam this is the + + + align:start position:0% +my K2 is this little beam this is the +original system a mass it's at it close + + align:start position:0% +original system a mass it's at it close + + + align:start position:0% +original system a mass it's at it close +to a natural frequency and the rotation + + align:start position:0% +to a natural frequency and the rotation + + + align:start position:0% +to a natural frequency and the rotation +rate of the The Eccentric mass is right + + align:start position:0% +rate of the The Eccentric mass is right + + + align:start position:0% +rate of the The Eccentric mass is right +at the natural frequency of this beam so + + align:start position:0% +at the natural frequency of this beam so + + + align:start position:0% +at the natural frequency of this beam so +because it's delicate to set up I got to + + align:start position:0% +because it's delicate to set up I got to + + + align:start position:0% +because it's delicate to set up I got to +show you the system first with the + + align:start position:0% +show you the system first with the + + + align:start position:0% +show you the system first with the +second Mass attached to it and I think + + align:start position:0% +second Mass attached to it and I think + + + align:start position:0% +second Mass attached to it and I think +I've got it tweaked so that it'll sit + + align:start position:0% +I've got it tweaked so that it'll sit + + + align:start position:0% +I've got it tweaked so that it'll sit +there it's right at the operating point + + align:start position:0% +there it's right at the operating point + + + align:start position:0% +there it's right at the operating point +and you ought to see the second Mass + + align:start position:0% +and you ought to see the second Mass + + + align:start position:0% +and you ought to see the second Mass +moving like crazy and the the original + + align:start position:0% +moving like crazy and the the original + + + align:start position:0% +moving like crazy and the the original +Mass The Beam not moving much at all + + align:start position:0% +Mass The Beam not moving much at all + + + align:start position:0% +Mass The Beam not moving much at all +so let's see if we can make it + + align:start position:0% +so let's see if we can make it + + + align:start position:0% +so let's see if we can make it +work we're going to need to kill the + + align:start position:0% + + + + align:start position:0% + +lights and you can see in + + align:start position:0% +lights and you can see in + + + align:start position:0% +lights and you can see in +here you can see the rotating Mass going + + align:start position:0% +here you can see the rotating Mass going + + + align:start position:0% +here you can see the rotating Mass going +around and around and so I have the + + align:start position:0% +around and around and so I have the + + + align:start position:0% +around and around and so I have the +strobe light detuned just a little bit + + align:start position:0% +strobe light detuned just a little bit + + + align:start position:0% +strobe light detuned just a little bit +so that you can see the system it's not + + align:start position:0% +so that you can see the system it's not + + + align:start position:0% +so that you can see the system it's not +quite synchronous you can watch this + + align:start position:0% +quite synchronous you can watch this + + + align:start position:0% +quite synchronous you can watch this +little white blob out here you see it + + align:start position:0% +little white blob out here you see it + + + align:start position:0% +little white blob out here you see it +going up and + + align:start position:0% +going up and + + + align:start position:0% +going up and +down that's your second mass and does + + align:start position:0% +down that's your second mass and does + + + align:start position:0% +down that's your second mass and does +the is the main beam it's moving a + + align:start position:0% +the is the main beam it's moving a + + + align:start position:0% +the is the main beam it's moving a +little bit but not + + align:start position:0% +little bit but not + + + align:start position:0% +little bit but not +much got a little damping and so it + + align:start position:0% +much got a little damping and so it + + + align:start position:0% +much got a little damping and so it +isn't perfectly down at that null point + + align:start position:0% +isn't perfectly down at that null point + + + align:start position:0% +isn't perfectly down at that null point +but very close so this is the system + + align:start position:0% +but very close so this is the system + + + align:start position:0% +but very close so this is the system +operating close to that n point so now + + align:start position:0% +operating close to that n point so now + + + align:start position:0% +operating close to that n point so now +if I + + align:start position:0% +if I + + + align:start position:0% +if I +remove the + + align:start position:0% +remove the + + + align:start position:0% +remove the +Dynamic absorber the second little Mass + + align:start position:0% +Dynamic absorber the second little Mass + + + align:start position:0% +Dynamic absorber the second little Mass +spring system then the main mass and the + + align:start position:0% +spring system then the main mass and the + + + align:start position:0% +spring system then the main mass and the +beam a of shake like + + align:start position:0% + + + + align:start position:0% + +crazy + + align:start position:0% + + + + align:start position:0% + +okay just changing the tuning a little + + align:start position:0% +okay just changing the tuning a little + + + align:start position:0% +okay just changing the tuning a little +here + + align:start position:0% + + + + align:start position:0% + +okay so + + align:start position:0% + + + + align:start position:0% + +now I'm going to + + align:start position:0% +now I'm going to + + + align:start position:0% +now I'm going to +remove the + + align:start position:0% + + + + align:start position:0% + +absorber all + + align:start position:0% +absorber all + + + align:start position:0% +absorber all +right and now + + align:start position:0% +right and now + + + align:start position:0% +right and now +it's going like + + align:start position:0% + + + + align:start position:0% + +crazy so that's an + + align:start position:0% +crazy so that's an + + + align:start position:0% +crazy so that's an +illustration you come up the + + align:start position:0% + + + + align:start position:0% + +lights now you hear it + + align:start position:0% + + + + align:start position:0% + +beating this little pen this little + + align:start position:0% +beating this little pen this little + + + align:start position:0% +beating this little pen this little +rotor in here is driven by a little DC + + align:start position:0% +rotor in here is driven by a little DC + + + align:start position:0% +rotor in here is driven by a little DC +motor and a single doua + + align:start position:0% +motor and a single doua + + + align:start position:0% +motor and a single doua +battery and it's not feedback controlled + + align:start position:0% +battery and it's not feedback controlled + + + align:start position:0% +battery and it's not feedback controlled +its frequency can vary and it isn't that + + align:start position:0% +its frequency can vary and it isn't that + + + align:start position:0% +its frequency can vary and it isn't that +powerful so this thing starts moving up + + align:start position:0% +powerful so this thing starts moving up + + + align:start position:0% +powerful so this thing starts moving up +and down it actually takes real torque + + align:start position:0% +and down it actually takes real torque + + + align:start position:0% +and down it actually takes real torque +to make that weight go around while this + + align:start position:0% +to make that weight go around while this + + + align:start position:0% +to make that weight go around while this +whole system is accelerating up and down + + align:start position:0% +whole system is accelerating up and down + + + align:start position:0% +whole system is accelerating up and down +and the motor just isn't up to it just + + align:start position:0% +and the motor just isn't up to it just + + + align:start position:0% +and the motor just isn't up to it just +isn't powerful enough so the speed + + align:start position:0% +isn't powerful enough so the speed + + + align:start position:0% +isn't powerful enough so the speed +changes so this isn't an this thing + + align:start position:0% +changes so this isn't an this thing + + + align:start position:0% +changes so this isn't an this thing +can't hold constant frequency anyway + + align:start position:0% +can't hold constant frequency anyway + + + align:start position:0% +can't hold constant frequency anyway +that's the uh so that's the demo + + align:start position:0% + + + + align:start position:0% + +questions so we've kind of embedded in + + align:start position:0% +questions so we've kind of embedded in + + + align:start position:0% +questions so we've kind of embedded in +this lecture this lecture was to + + align:start position:0% +this lecture this lecture was to + + + align:start position:0% +this lecture this lecture was to +introduce you to the idea that there are + + align:start position:0% +introduce you to the idea that there are + + + align:start position:0% +introduce you to the idea that there are +you can write a transfer function for a + + align:start position:0% +you can write a transfer function for a + + + align:start position:0% +you can write a transfer function for a +multiple degree of Freedom system has + + align:start position:0% +multiple degree of Freedom system has + + + align:start position:0% +multiple degree of Freedom system has +embedded in it all the natural + + align:start position:0% +embedded in it all the natural + + + align:start position:0% +embedded in it all the natural +frequencies of the system when you use a + + align:start position:0% +frequencies of the system when you use a + + + align:start position:0% +frequencies of the system when you use a +transfer function to calculate the + + align:start position:0% +transfer function to calculate the + + + align:start position:0% +transfer function to calculate the +response of the system you are getting + + align:start position:0% +response of the system you are getting + + + align:start position:0% +response of the system you are getting +the contributions of all the modes at + + align:start position:0% +the contributions of all the modes at + + + align:start position:0% +the contributions of all the modes at +once so you've essentially solve the + + align:start position:0% +once so you've essentially solve the + + + align:start position:0% +once so you've essentially solve the +equations of motion + + align:start position:0% +equations of motion + + + align:start position:0% +equations of motion +directly so you now have seen there's + + align:start position:0% +directly so you now have seen there's + + + align:start position:0% +directly so you now have seen there's +two ways to go about analyzing multiple + + align:start position:0% +two ways to go about analyzing multiple + + + align:start position:0% +two ways to go about analyzing multiple +degree of Freedom systems the technique + + align:start position:0% +degree of Freedom systems the technique + + + align:start position:0% +degree of Freedom systems the technique +known as modal analysis one mode at a + + align:start position:0% +known as modal analysis one mode at a + + + align:start position:0% +known as modal analysis one mode at a +time then add it together there or like + + align:start position:0% +time then add it together there or like + + + align:start position:0% +time then add it together there or like +with transfer functions where you're + + align:start position:0% +with transfer functions where you're + + + align:start position:0% +with transfer functions where you're +just solving the whole thing at once and + + align:start position:0% +just solving the whole thing at once and + + + align:start position:0% +just solving the whole thing at once and +each transfer function has in it all of + + align:start position:0% +each transfer function has in it all of + + + align:start position:0% +each transfer function has in it all of +the information about all of the modes + + align:start position:0% +the information about all of the modes + + + align:start position:0% +the information about all of the modes +of the system so if it's five degree + + align:start position:0% +of the system so if it's five degree + + + align:start position:0% +of the system so if it's five degree +Freedom system you're going to see five + + align:start position:0% +Freedom system you're going to see five + + + align:start position:0% +Freedom system you're going to see five +Peaks out + + align:start position:0% +Peaks out + + + align:start position:0% +Peaks out +here all right + + align:start position:0% + + + + align:start position:0% + +questions long run stuff but initially + + align:start position:0% +questions long run stuff but initially + + + align:start position:0% +questions long run stuff but initially +since you have a force on mass one does + + align:start position:0% +since you have a force on mass one does + + + align:start position:0% +since you have a force on mass one does +it have to out moving to get into moving + + align:start position:0% +it have to out moving to get into moving + + + align:start position:0% +it have to out moving to get into moving +and then it + + align:start position:0% +and then it + + + align:start position:0% +and then it +stops so there's going to be a transient + + align:start position:0% +stops so there's going to be a transient + + + align:start position:0% +stops so there's going to be a transient +phase sure when you any any system when + + align:start position:0% +phase sure when you any any system when + + + align:start position:0% +phase sure when you any any system when +you start it up is going to have + + align:start position:0% +you start it up is going to have + + + align:start position:0% +you start it up is going to have +transients and the + + align:start position:0% +transients and the + + + align:start position:0% +transients and the +transients are the equivalent of initial + + align:start position:0% +transients are the equivalent of initial + + + align:start position:0% +transients are the equivalent of initial +conditions so on displacement and + + align:start position:0% +conditions so on displacement and + + + align:start position:0% +conditions so on displacement and +velocity and the response of + + align:start position:0% +velocity and the response of + + + align:start position:0% +velocity and the response of +a linear system that vibrates that has + + align:start position:0% +a linear system that vibrates that has + + + align:start position:0% +a linear system that vibrates that has +natural frequencies to a set of initial + + align:start position:0% +natural frequencies to a set of initial + + + align:start position:0% +natural frequencies to a set of initial +conditions is vibration at what + + align:start position:0% + + + + align:start position:0% + +frequencies do you know how they + + align:start position:0% +frequencies do you know how they + + + align:start position:0% +frequencies do you know how they +overcome this in helicopters like the + + align:start position:0% +overcome this in helicopters like the + + + align:start position:0% +overcome this in helicopters like the +chin that we saw at the beginning of the + + align:start position:0% +chin that we saw at the beginning of the + + + align:start position:0% +chin that we saw at the beginning of the +year uh yeah the helicopter so I went to + + align:start position:0% +year uh yeah the helicopter so I went to + + + align:start position:0% +year uh yeah the helicopter so I went to +answer the question response to that + + align:start position:0% +answer the question response to that + + + align:start position:0% +answer the question response to that +transients is at the natural frequencies + + align:start position:0% +transients is at the natural frequencies + + + align:start position:0% +transients is at the natural frequencies +of the system maybe some combination the + + align:start position:0% +of the system maybe some combination the + + + align:start position:0% +of the system maybe some combination the +original displacement requires + + align:start position:0% +original displacement requires + + + align:start position:0% +original displacement requires +contributions of several modes you'll + + align:start position:0% +contributions of several modes you'll + + + align:start position:0% +contributions of several modes you'll +get Decay contributions at each of the + + align:start position:0% +get Decay contributions at each of the + + + align:start position:0% +get Decay contributions at each of the +natural frequencies and once they've + + align:start position:0% +natural frequencies and once they've + + + align:start position:0% +natural frequencies and once they've +died out this motor is started up the + + align:start position:0% +died out this motor is started up the + + + align:start position:0% +died out this motor is started up the +thing will settle into we call steady + + align:start position:0% +thing will settle into we call steady + + + align:start position:0% +thing will settle into we call steady +state response and it'll only be at the + + align:start position:0% +state response and it'll only be at the + + + align:start position:0% +state response and it'll only be at the +excitation frequency and I haven't shown + + align:start position:0% +excitation frequency and I haven't shown + + + align:start position:0% +excitation frequency and I haven't shown +you anything about you can can you solve + + align:start position:0% +you anything about you can can you solve + + + align:start position:0% +you anything about you can can you solve +the equations of motion from start up at + + align:start position:0% +the equations of motion from start up at + + + align:start position:0% +the equations of motion from start up at +time zero through the whole messy + + align:start position:0% +time zero through the whole messy + + + align:start position:0% +time zero through the whole messy +transient phase to steady state sure and + + align:start position:0% +transient phase to steady state sure and + + + align:start position:0% +transient phase to steady state sure and +we haven't talked at all about that and + + align:start position:0% +we haven't talked at all about that and + + + align:start position:0% +we haven't talked at all about that and +actually for for most vibration stuff it + + align:start position:0% +actually for for most vibration stuff it + + + align:start position:0% +actually for for most vibration stuff it +isn't very important steady St answer is + + align:start position:0% +isn't very important steady St answer is + + + align:start position:0% +isn't very important steady St answer is +important the transient answer is pretty + + align:start position:0% +important the transient answer is pretty + + + align:start position:0% +important the transient answer is pretty +important and for you to have a feeling + + align:start position:0% +important and for you to have a feeling + + + align:start position:0% +important and for you to have a feeling +for that you actually know quite a fair + + align:start position:0% +for that you actually know quite a fair + + + align:start position:0% +for that you actually know quite a fair +amount about the basic concept of how + + align:start position:0% +amount about the basic concept of how + + + align:start position:0% +amount about the basic concept of how +things vibrate now now your question + + align:start position:0% +things vibrate now now your question + + + align:start position:0% +things vibrate now now your question +about the helicopter so if you have a + + align:start position:0% +about the helicopter so if you have a + + + align:start position:0% +about the helicopter so if you have a +uniform helicopter blade I mean they + + align:start position:0% +uniform helicopter blade I mean they + + + align:start position:0% +uniform helicopter blade I mean they +they rigged that to do what it did they + + align:start position:0% +they rigged that to do what it did they + + + align:start position:0% +they rigged that to do what it did they +were I don't know what they're + + align:start position:0% +were I don't know what they're + + + align:start position:0% +were I don't know what they're +experimenting with but if you do there's + + align:start position:0% +experimenting with but if you do there's + + + align:start position:0% +experimenting with but if you do there's +a a problem that I've actually given in + + align:start position:0% +a a problem that I've actually given in + + + align:start position:0% +a a problem that I've actually given in +a vibration course if you design a + + align:start position:0% +a vibration course if you design a + + + align:start position:0% +a vibration course if you design a +really simple helicopter that has a + + align:start position:0% +really simple helicopter that has a + + + align:start position:0% +really simple helicopter that has a +uniform blade you know it's a uniform + + align:start position:0% +uniform blade you know it's a uniform + + + align:start position:0% +uniform blade you know it's a uniform +rod + + align:start position:0% +rod + + + align:start position:0% +rod +and it's pivoted at the center and you + + align:start position:0% +and it's pivoted at the center and you + + + align:start position:0% +and it's pivoted at the center and you +spin it up and if you spin it fast + + align:start position:0% +spin it up and if you spin it fast + + + align:start position:0% +spin it up and if you spin it fast +enough you know if you spin it slowly + + align:start position:0% +enough you know if you spin it slowly + + + align:start position:0% +enough you know if you spin it slowly +it'll droop because of gravity but if + + align:start position:0% +it'll droop because of gravity but if + + + align:start position:0% +it'll droop because of gravity but if +you spin it fast enough R Omega squar is + + align:start position:0% +you spin it fast enough R Omega squar is + + + align:start position:0% +you spin it fast enough R Omega squar is +a lot bigger than G and the thing + + align:start position:0% +a lot bigger than G and the thing + + + align:start position:0% +a lot bigger than G and the thing +flattens out and the blades are going + + align:start position:0% +flattens out and the blades are going + + + align:start position:0% +flattens out and the blades are going +round and round right the natural + + align:start position:0% +round and round right the natural + + + align:start position:0% +round and round right the natural +frequency of that system is exactly the + + align:start position:0% +frequency of that system is exactly the + + + align:start position:0% +frequency of that system is exactly the +rotation + + align:start position:0% +rotation + + + align:start position:0% +rotation +rate a uniform blade pivot at the center + + align:start position:0% +rate a uniform blade pivot at the center + + + align:start position:0% +rate a uniform blade pivot at the center +going around fast has a natural + + align:start position:0% +going around fast has a natural + + + align:start position:0% +going around fast has a natural +frequency like this it Happ s to be + + align:start position:0% +frequency like this it Happ s to be + + + align:start position:0% +frequency like this it Happ s to be +exactly at the rate of rotation so it is + + align:start position:0% +exactly at the rate of rotation so it is + + + align:start position:0% +exactly at the rate of rotation so it is +at any perturbation will start it doing + + align:start position:0% +at any perturbation will start it doing + + + align:start position:0% +at any perturbation will start it doing +bad things helicopters never ever + + align:start position:0% +bad things helicopters never ever + + + align:start position:0% +bad things helicopters never ever +designed like + + align:start position:0% +designed like + + + align:start position:0% +designed like +that the helicopter has a the rotor disc + + align:start position:0% +that the helicopter has a the rotor disc + + + align:start position:0% +that the helicopter has a the rotor disc +in here has a finite radius before the + + align:start position:0% +in here has a finite radius before the + + + align:start position:0% +in here has a finite radius before the +pin and then the blades are out + + align:start position:0% +pin and then the blades are out + + + align:start position:0% +pin and then the blades are out +here the pin around which and that + + align:start position:0% +here the pin around which and that + + + align:start position:0% +here the pin around which and that +changes the resonance frequency and of + + align:start position:0% +changes the resonance frequency and of + + + align:start position:0% +changes the resonance frequency and of +course you can change the mass + + align:start position:0% +course you can change the mass + + + align:start position:0% +course you can change the mass +distribution in the blade and so forth + + align:start position:0% +distribution in the blade and so forth + + + align:start position:0% +distribution in the blade and so forth +so + + align:start position:0% +so + + + align:start position:0% +so +uh you know what they had done in that + + align:start position:0% +uh you know what they had done in that + + + align:start position:0% +uh you know what they had done in that +that want that case to rig it so the + + align:start position:0% +that want that case to rig it so the + + + align:start position:0% +that want that case to rig it so the +thing beat itself to death I don't know + + align:start position:0% +thing beat itself to death I don't know + + + align:start position:0% +thing beat itself to death I don't know +but they there's good design practices + + align:start position:0% +but they there's good design practices + + + align:start position:0% +but they there's good design practices +with helicopters so that the the blade + + align:start position:0% +with helicopters so that the the blade + + + align:start position:0% +with helicopters so that the the blade +frequency is not at the rotation rate + + align:start position:0% +frequency is not at the rotation rate + + + align:start position:0% +frequency is not at the rotation rate +because at rotation rate you're going to + + align:start position:0% +because at rotation rate you're going to + + + align:start position:0% +because at rotation rate you're going to +a lot of excitation right hitting + + align:start position:0% +a lot of excitation right hitting + + + align:start position:0% +a lot of excitation right hitting +turbulence in the air and so + + align:start position:0% + + + + align:start position:0% + +forth Yeah you mentioned that they use + + align:start position:0% +forth Yeah you mentioned that they use + + + align:start position:0% +forth Yeah you mentioned that they use +um something like this in a Handcock + + align:start position:0% +um something like this in a Handcock + + + align:start position:0% +um something like this in a Handcock +building I imagine that the wind force + + align:start position:0% +building I imagine that the wind force + + + align:start position:0% +building I imagine that the wind force +on the Handcock building does not have a + + align:start position:0% +on the Handcock building does not have a + + + align:start position:0% +on the Handcock building does not have a +uniform frequency all right is the idea + + align:start position:0% +uniform frequency all right is the idea + + + align:start position:0% +uniform frequency all right is the idea +that you know this will control + + align:start position:0% +that you know this will control + + + align:start position:0% +that you know this will control +basically the resonant + + align:start position:0% + + + + align:start position:0% + +frequency so the uh D the I've forgotten + + align:start position:0% +frequency so the uh D the I've forgotten + + + align:start position:0% +frequency so the uh D the I've forgotten +the correct name now even know I've used + + align:start position:0% +the correct name now even know I've used + + + align:start position:0% +the correct name now even know I've used +these many times now the uh optimally + + align:start position:0% +these many times now the uh optimally + + + align:start position:0% +these many times now the uh optimally +tuned and damped Dynamic absorber is + + align:start position:0% +tuned and damped Dynamic absorber is + + + align:start position:0% +tuned and damped Dynamic absorber is +sort of the second level of of uh this + + align:start position:0% +sort of the second level of of uh this + + + align:start position:0% +sort of the second level of of uh this +is of gradu of U Dynamic absorber + + align:start position:0% +is of gradu of U Dynamic absorber + + + align:start position:0% +is of gradu of U Dynamic absorber +design typically a two degree Freedom + + align:start position:0% +design typically a two degree Freedom + + + align:start position:0% +design typically a two degree Freedom +system looks like that if it's lightly + + align:start position:0% +system looks like that if it's lightly + + + align:start position:0% +system looks like that if it's lightly +damped but you can design that second + + align:start position:0% +damped but you can design that second + + + align:start position:0% +damped but you can design that second +Mass spring and a damper so that you can + + align:start position:0% +Mass spring and a damper so that you can + + + align:start position:0% +Mass spring and a damper so that you can +make the response the transfer function + + align:start position:0% +make the response the transfer function + + + align:start position:0% +make the response the transfer function +h11 here look like + + align:start position:0% +h11 here look like + + + align:start position:0% +h11 here look like +this where you get the two height the + + align:start position:0% +this where you get the two height the + + + align:start position:0% +this where you get the two height the +two peaks are of equal height and the + + align:start position:0% +two peaks are of equal height and the + + + align:start position:0% +two peaks are of equal height and the +worst you you can design them so that + + align:start position:0% +worst you you can design them so that + + + align:start position:0% +worst you you can design them so that +the worst case amplitude response over + + align:start position:0% +the worst case amplitude response over + + + align:start position:0% +the worst case amplitude response over +here is pretty low it's + + align:start position:0% +here is pretty low it's + + + align:start position:0% +here is pretty low it's +uh X1 static is + + align:start position:0% +uh X1 static is + + + align:start position:0% +uh X1 static is +like square otk of 1 + + align:start position:0% +like square otk of 1 + + + align:start position:0% +like square otk of 1 +over 1 + mu or something like that so + + align:start position:0% +over 1 + mu or something like that so + + + align:start position:0% +over 1 + mu or something like that so +and the bigger you make this the better + + align:start position:0% +and the bigger you make this the better + + + align:start position:0% +and the bigger you make this the better +the performance so and but you have to + + align:start position:0% +the performance so and but you have to + + + align:start position:0% +the performance so and but you have to +have a you have to have Optimum damping + + align:start position:0% +have a you have to have Optimum damping + + + align:start position:0% +have a you have to have Optimum damping +and you have to have Optimum tuning and + + align:start position:0% +and you have to have Optimum tuning and + + + align:start position:0% +and you have to have Optimum tuning and +your tuning means if the the + + align:start position:0% +your tuning means if the the + + + align:start position:0% +your tuning means if the the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +the we tune this thing so that K2 over + + align:start position:0% +the we tune this thing so that K2 over + + + align:start position:0% +the we tune this thing so that K2 over +M2 was exactly equal to a particular + + align:start position:0% +M2 was exactly equal to a particular + + + align:start position:0% +M2 was exactly equal to a particular +frequency in this case K1 over M1 but + + align:start position:0% +frequency in this case K1 over M1 but + + + align:start position:0% +frequency in this case K1 over M1 but +for the optimally tuned and damp Dynamic + + align:start position:0% +for the optimally tuned and damp Dynamic + + + align:start position:0% +for the optimally tuned and damp Dynamic +absorber you actually tune things it's + + align:start position:0% +absorber you actually tune things it's + + + align:start position:0% +absorber you actually tune things it's +tuned a little differently you put + + align:start position:0% +tuned a little differently you put + + + align:start position:0% +tuned a little differently you put +damping in it and you make it behave + + align:start position:0% +damping in it and you make it behave + + + align:start position:0% +damping in it and you make it behave +pretty well over the entire frequency + + align:start position:0% +pretty well over the entire frequency + + + align:start position:0% +pretty well over the entire frequency +range rather than + + align:start position:0% +range rather than + + + align:start position:0% +range rather than +almost perfect at one frequency and the + + align:start position:0% +almost perfect at one frequency and the + + + align:start position:0% +almost perfect at one frequency and the +Hancock Building had uh its transfer + + align:start position:0% +Hancock Building had uh its transfer + + + align:start position:0% +Hancock Building had uh its transfer +function so to speak without the dynamic + + align:start position:0% +function so to speak without the dynamic + + + align:start position:0% +function so to speak without the dynamic +absorber it had it has many many Peaks + + align:start position:0% +absorber it had it has many many Peaks + + + align:start position:0% +absorber it had it has many many Peaks +but it had two problematic ones that + + align:start position:0% +but it had two problematic ones that + + + align:start position:0% +but it had two problematic ones that +were very close together and they were + + align:start position:0% +were very close together and they were + + + align:start position:0% +were very close together and they were +at about + + align:start position:0% + + + + align:start position:0% + +uh8 radians per second or and like 081 + + align:start position:0% +uh8 radians per second or and like 081 + + + align:start position:0% +uh8 radians per second or and like 081 +or something and this was + + align:start position:0% +or something and this was + + + align:start position:0% +or something and this was +bending and this was + + align:start position:0% + + + + align:start position:0% + +torsion it had these two resonances and + + align:start position:0% +torsion it had these two resonances and + + + align:start position:0% +torsion it had these two resonances and +the wind would come along and it excite + + align:start position:0% +the wind would come along and it excite + + + align:start position:0% +the wind would come along and it excite +both of them and the one resonance was + + align:start position:0% +both of them and the one resonance was + + + align:start position:0% +both of them and the one resonance was +just the same as this thing it just + + align:start position:0% +just the same as this thing it just + + + align:start position:0% +just the same as this thing it just +bends on the other resonance was the + + align:start position:0% +bends on the other resonance was the + + + align:start position:0% +bends on the other resonance was the +first mode in torsion so the if you were + + align:start position:0% +first mode in torsion so the if you were + + + align:start position:0% +first mode in torsion so the if you were +standing on one and building + + align:start position:0% +standing on one and building + + + align:start position:0% +standing on one and building +crosssection is a funny Hancock + + align:start position:0% +crosssection is a funny Hancock + + + align:start position:0% +crosssection is a funny Hancock +buildings looks kind of like that in + + align:start position:0% +buildings looks kind of like that in + + + align:start position:0% +buildings looks kind of like that in +cross-section and so it would it would + + align:start position:0% +cross-section and so it would it would + + + align:start position:0% +cross-section and so it would it would +rotate in torsion and deflect in bending + + align:start position:0% +rotate in torsion and deflect in bending + + + align:start position:0% +rotate in torsion and deflect in bending +so it would be rotating and + + align:start position:0% +so it would be rotating and + + + align:start position:0% +so it would be rotating and +deflecting and if they were in equal + + align:start position:0% +deflecting and if they were in equal + + + align:start position:0% +deflecting and if they were in equal +amounts and in close they're close in + + align:start position:0% +amounts and in close they're close in + + + align:start position:0% +amounts and in close they're close in +frequency if you were standing up there + + align:start position:0% +frequency if you were standing up there + + + align:start position:0% +frequency if you were standing up there +what would you + + align:start position:0% +what would you + + + align:start position:0% +what would you +feel they would beat the motion would + + align:start position:0% +feel they would beat the motion would + + + align:start position:0% +feel they would beat the motion would +beat you'd get a lot of motion because + + align:start position:0% +beat you'd get a lot of motion because + + + align:start position:0% +beat you'd get a lot of motion because +the if you were on one end of the + + align:start position:0% +the if you were on one end of the + + + align:start position:0% +the if you were on one end of the +building you'd get a lot of torsional + + align:start position:0% +building you'd get a lot of torsional + + + align:start position:0% +building you'd get a lot of torsional +motion out here combined with the + + align:start position:0% +motion out here combined with the + + + align:start position:0% +motion out here combined with the +bending motion + + align:start position:0% +bending motion + + + align:start position:0% +bending motion +and then they would cancel and then the + + align:start position:0% +and then they would cancel and then the + + + align:start position:0% +and then they would cancel and then the +beat would build up again and so that + + align:start position:0% +beat would build up again and so that + + + align:start position:0% +beat would build up again and so that +was what was happening in the building + + align:start position:0% +was what was happening in the building + + + align:start position:0% +was what was happening in the building +the uh and they put in + + align:start position:0% +the uh and they put in + + + align:start position:0% +the uh and they put in +two so on the 58th + + align:start position:0% +two so on the 58th + + + align:start position:0% +two so on the 58th +floor on each + + align:start position:0% +floor on each + + + align:start position:0% +floor on each +end they put in a mass spring + + align:start position:0% +end they put in a mass spring + + + align:start position:0% +end they put in a mass spring +system over here another + + align:start position:0% +system over here another + + + align:start position:0% +system over here another +one so that they would resist the + + align:start position:0% +one so that they would resist the + + + align:start position:0% +one so that they would resist the +torsion actually they really I Lin them + + align:start position:0% +torsion actually they really I Lin them + + + align:start position:0% +torsion actually they really I Lin them +up the wrong way they line up this way + + align:start position:0% +up the wrong way they line up this way + + + align:start position:0% +up the wrong way they line up this way +so it has two of them they can resist + + align:start position:0% +so it has two of them they can resist + + + align:start position:0% +so it has two of them they can resist +both the bending and the torsion that + + align:start position:0% +both the bending and the torsion that + + + align:start position:0% +both the bending and the torsion that +each weigh 300 tons and they were it was + + align:start position:0% +each weigh 300 tons and they were it was + + + align:start position:0% +each weigh 300 tons and they were it was +comb it's a box with 50 filled up with + + align:start position:0% +comb it's a box with 50 filled up with + + + align:start position:0% +comb it's a box with 50 filled up with +50 PB lead bricks and the box is about I + + align:start position:0% +50 PB lead bricks and the box is about I + + + align:start position:0% +50 PB lead bricks and the box is about I +it's been 20 years since I was up there + + align:start position:0% +it's been 20 years since I was up there + + + align:start position:0% +it's been 20 years since I was up there +but my recall is it's like 8 by 10 feet + + align:start position:0% +but my recall is it's like 8 by 10 feet + + + align:start position:0% +but my recall is it's like 8 by 10 feet +and yay tall and it slides on a + + align:start position:0% +and yay tall and it slides on a + + + align:start position:0% +and yay tall and it slides on a +pressurized oil film and the spring + + align:start position:0% +pressurized oil film and the spring + + + align:start position:0% +pressurized oil film and the spring +spring on it is a big pneumatic spring + + align:start position:0% +spring on it is a big pneumatic spring + + + align:start position:0% +spring on it is a big pneumatic spring +big air spring and a computer runs the + + align:start position:0% +big air spring and a computer runs the + + + align:start position:0% +big air spring and a computer runs the +whole system it's shut down till the + + align:start position:0% +whole system it's shut down till the + + + align:start position:0% +whole system it's shut down till the +wind gets above 40 m hour and then it + + align:start position:0% +wind gets above 40 m hour and then it + + + align:start position:0% +wind gets above 40 m hour and then it +turns it on and it's actually kind of + + align:start position:0% +turns it on and it's actually kind of + + + align:start position:0% +turns it on and it's actually kind of +self-tuning it can optimize itself and + + align:start position:0% +self-tuning it can optimize itself and + + + align:start position:0% +self-tuning it can optimize itself and +then it'll sit there and it's designed + + align:start position:0% +then it'll sit there and it's designed + + + align:start position:0% +then it'll sit there and it's designed +to do this because this building has + + align:start position:0% +to do this because this building has + + + align:start position:0% +to do this because this building has +these two problem + + align:start position:0% +these two problem + + + align:start position:0% +these two problem +frequencies and so it has been designed + + align:start position:0% +frequencies and so it has been designed + + + align:start position:0% +frequencies and so it has been designed +to uh address both of + + align:start position:0% +to uh address both of + + + align:start position:0% +to uh address both of +them yeah all right I think uh we I have + + align:start position:0% +them yeah all right I think uh we I have + + + align:start position:0% +them yeah all right I think uh we I have +to get out of here for the next class + + align:start position:0% +to get out of here for the next class + + + align:start position:0% +to get out of here for the next class +see you next Tuesday last lecture \ No newline at end of file diff --git a/h5KiY9lvHc4.txt b/h5KiY9lvHc4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b36fc8c2a468521d2307d6a4aa4d1ec8fdb1d2cf --- /dev/null +++ b/h5KiY9lvHc4.txt @@ -0,0 +1,8392 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +to view additional materials from + + align:start position:0% +to view additional materials from + + + align:start position:0% +to view additional materials from +hundreds of MIT courses visit MIT open + + align:start position:0% +hundreds of MIT courses visit MIT open + + + align:start position:0% +hundreds of MIT courses visit MIT open +courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu okay shall we start okay so + + align:start position:0% +ocw.mit.edu okay shall we start okay so + + + align:start position:0% +ocw.mit.edu okay shall we start okay so +um the the main job of today is igen + + align:start position:0% +um the the main job of today is igen + + + align:start position:0% +um the the main job of today is igen +values and igen vectors + + align:start position:0% +values and igen vectors + + + align:start position:0% +values and igen vectors +the next section in the book and a very + + align:start position:0% +the next section in the book and a very + + + align:start position:0% +the next section in the book and a very +big topic and things to say about it um + + align:start position:0% +big topic and things to say about it um + + + align:start position:0% +big topic and things to say about it um +I do want to begin with a recap of what + + align:start position:0% +I do want to begin with a recap of what + + + align:start position:0% +I do want to begin with a recap of what +I didn't quite finish last time uh so + + align:start position:0% +I didn't quite finish last time uh so + + + align:start position:0% +I didn't quite finish last time uh so +what we did was solve this very + + align:start position:0% +what we did was solve this very + + + align:start position:0% +what we did was solve this very +straightforward equation straightforward + + align:start position:0% +straightforward equation straightforward + + + align:start position:0% +straightforward equation straightforward +except that it has a point source a + + align:start position:0% +except that it has a point source a + + + align:start position:0% +except that it has a point source a +Delta function and we solved it both the + + align:start position:0% +Delta function and we solved it both the + + + align:start position:0% +Delta function and we solved it both the +fixed fixed case when uh straight line + + align:start position:0% +fixed fixed case when uh straight line + + + align:start position:0% +fixed fixed case when uh straight line +went up and back down and in the freef + + align:start position:0% +went up and back down and in the freef + + + align:start position:0% +went up and back down and in the freef +fixed case when it was a horizontal line + + align:start position:0% +fixed case when it was a horizontal line + + + align:start position:0% +fixed case when it was a horizontal line +and then down with slope minus one and + + align:start position:0% +and then down with slope minus one and + + + align:start position:0% +and then down with slope minus one and +and looking there are different ways to + + align:start position:0% +and looking there are different ways to + + + align:start position:0% +and looking there are different ways to +get to this answer but once you have it + + align:start position:0% +get to this answer but once you have it + + + align:start position:0% +get to this answer but once you have it +you can look at it and say well is it + + align:start position:0% +you can look at it and say well is it + + + align:start position:0% +you can look at it and say well is it +right certainly the boundary conditions + + align:start position:0% +right certainly the boundary conditions + + + align:start position:0% +right certainly the boundary conditions +are correct zero slope went through zero + + align:start position:0% +are correct zero slope went through zero + + + align:start position:0% +are correct zero slope went through zero +that's good and then the only thing you + + align:start position:0% +that's good and then the only thing you + + + align:start position:0% +that's good and then the only thing you +really have to check is does the slope + + align:start position:0% +really have to check is does the slope + + + align:start position:0% +really have to check is does the slope +drop by one at the point of the impulse + + align:start position:0% +drop by one at the point of the impulse + + + align:start position:0% +drop by one at the point of the impulse +because that's what this is forcing us + + align:start position:0% +because that's what this is forcing us + + + align:start position:0% +because that's what this is forcing us +to do it's saying the slope should drop + + align:start position:0% +to do it's saying the slope should drop + + + align:start position:0% +to do it's saying the slope should drop +by one and here the slope is 1 minus a + + align:start position:0% +by one and here the slope is 1 minus a + + + align:start position:0% +by one and here the slope is 1 minus a +going up and if I take the derivative + + align:start position:0% +going up and if I take the derivative + + + align:start position:0% +going up and if I take the derivative +it's minus a going + + align:start position:0% +it's minus a going + + + align:start position:0% +it's minus a going +down 1 minus a dropped to minus a good + + align:start position:0% +down 1 minus a dropped to minus a good + + + align:start position:0% +down 1 minus a dropped to minus a good +here the slope was zero here the slope + + align:start position:0% +here the slope was zero here the slope + + + align:start position:0% +here the slope was zero here the slope +was minus1 good okay so those are the + + align:start position:0% +was minus1 good okay so those are the + + + align:start position:0% +was minus1 good okay so those are the +right answers and that's + + align:start position:0% +right answers and that's + + + align:start position:0% +right answers and that's +a this is a simple but really uh great + + align:start position:0% +a this is a simple but really uh great + + + align:start position:0% +a this is a simple but really uh great +example and then what I wanted to do + + align:start position:0% +example and then what I wanted to do + + + align:start position:0% +example and then what I wanted to do +was catch the same thing for the + + align:start position:0% +was catch the same thing for the + + + align:start position:0% +was catch the same thing for the +matrices so those + + align:start position:0% +matrices so those + + + align:start position:0% +matrices so those +matrices uh we all know what K is and + + align:start position:0% +matrices uh we all know what K is and + + + align:start position:0% +matrices uh we all know what K is and +what T is so I'm solving I'm really + + align:start position:0% +what T is so I'm solving I'm really + + + align:start position:0% +what T is so I'm solving I'm really +solving + + align:start position:0% +solving + + + align:start position:0% +solving +k k inverse equal identity that's that's + + align:start position:0% +k k inverse equal identity that's that's + + + align:start position:0% +k k inverse equal identity that's that's +the equation I'm solving so I'm looking + + align:start position:0% +the equation I'm solving so I'm looking + + + align:start position:0% +the equation I'm solving so I'm looking +for K inverse and trying to get The + + align:start position:0% +for K inverse and trying to get The + + + align:start position:0% +for K inverse and trying to get The +Columns of the + + align:start position:0% +Columns of the + + + align:start position:0% +Columns of the +identity and you realize The Columns of + + align:start position:0% +identity and you realize The Columns of + + + align:start position:0% +identity and you realize The Columns of +the identity are just like Delta vectors + + align:start position:0% +the identity are just like Delta vectors + + + align:start position:0% +the identity are just like Delta vectors +they've got a one in one spot they're a + + align:start position:0% +they've got a one in one spot they're a + + + align:start position:0% +they've got a one in one spot they're a +point load just like this thing okay so + + align:start position:0% +point load just like this thing okay so + + + align:start position:0% +point load just like this thing okay so +can I just say how I get how I remember + + align:start position:0% +can I just say how I get how I remember + + + align:start position:0% +can I just say how I get how I remember +K inverse I finally you know again there + + align:start position:0% +K inverse I finally you know again there + + + align:start position:0% +K inverse I finally you know again there +are different ways to get to to + + align:start position:0% +are different ways to get to to + + + align:start position:0% +are different ways to get to to +it one way is matl just do it but + + align:start position:0% +it one way is matl just do it but + + + align:start position:0% +it one way is matl just do it but +uh I guess maybe the whole point is the + + align:start position:0% +uh I guess maybe the whole point is the + + + align:start position:0% +uh I guess maybe the whole point is the +whole point of + + align:start position:0% +whole point of + + + align:start position:0% +whole point of +these and and the igen values that are + + align:start position:0% +these and and the igen values that are + + + align:start position:0% +these and and the igen values that are +coming to is this + + align:start position:0% +coming to is this + + + align:start position:0% +coming to is this +that we have here the chance to see + + align:start position:0% +that we have here the chance to see + + + align:start position:0% +that we have here the chance to see +important special cases that work out + + align:start position:0% +important special cases that work out + + + align:start position:0% +important special cases that work out +normally we don't find the inverse print + + align:start position:0% +normally we don't find the inverse print + + + align:start position:0% +normally we don't find the inverse print +out the inverse of a matrix it's not + + align:start position:0% +out the inverse of a matrix it's not + + + align:start position:0% +out the inverse of a matrix it's not +nice normally we just let I find the + + align:start position:0% +nice normally we just let I find the + + + align:start position:0% +nice normally we just let I find the +igen values because that's a even worse + + align:start position:0% +igen values because that's a even worse + + + align:start position:0% +igen values because that's a even worse +calculation to find igen values in + + align:start position:0% +calculation to find igen values in + + + align:start position:0% +calculation to find igen values in +general for I'm talking here about our + + align:start position:0% +general for I'm talking here about our + + + align:start position:0% +general for I'm talking here about our +matrices of all sizes n byn nobody finds + + align:start position:0% +matrices of all sizes n byn nobody finds + + + align:start position:0% +matrices of all sizes n byn nobody finds +the igen values by hand of n byn + + align:start position:0% +the igen values by hand of n byn + + + align:start position:0% +the igen values by hand of n byn +matrices but these have terrific igen + + align:start position:0% +matrices but these have terrific igen + + + align:start position:0% +matrices but these have terrific igen +values and especially igen vectors so uh + + align:start position:0% +values and especially igen vectors so uh + + + align:start position:0% +values and especially igen vectors so uh +in a way this is a little bit like + + align:start position:0% +in a way this is a little bit like + + + align:start position:0% +in a way this is a little bit like +typical of math that you ask about + + align:start position:0% +typical of math that you ask about + + + align:start position:0% +typical of math that you ask about +General stuff where you write the + + align:start position:0% +General stuff where you write the + + + align:start position:0% +General stuff where you write the +equation with a with a matrix + + align:start position:0% +equation with a with a matrix + + + align:start position:0% +equation with a with a matrix +a and so that's the general information + + align:start position:0% +a and so that's the general information + + + align:start position:0% +a and so that's the general information +and then there's the specific special + + align:start position:0% +and then there's the specific special + + + align:start position:0% +and then there's the specific special +guys with special functions and here + + align:start position:0% +guys with special functions and here + + + align:start position:0% +guys with special functions and here +they'll be signs and cosiness and + + align:start position:0% +they'll be signs and cosiness and + + + align:start position:0% +they'll be signs and cosiness and +exponentials other places in applied + + align:start position:0% +exponentials other places in applied + + + align:start position:0% +exponentials other places in applied +math they're Bessel functions and the + + align:start position:0% +math they're Bessel functions and the + + + align:start position:0% +math they're Bessel functions and the +genre functions special guys so here + + align:start position:0% +genre functions special guys so here + + + align:start position:0% +genre functions special guys so here +these are special then and how how do I + + align:start position:0% +these are special then and how how do I + + + align:start position:0% +these are special then and how how do I +complete K inverse so this 432 1 well + + align:start position:0% +complete K inverse so this 432 1 well + + + align:start position:0% +complete K inverse so this 432 1 well +I'm let me let me complete T inverse you + + align:start position:0% +I'm let me let me complete T inverse you + + + align:start position:0% +I'm let me let me complete T inverse you +probably know T inverse already so T + + align:start position:0% +probably know T inverse already so T + + + align:start position:0% +probably know T inverse already so T +this is 4321 is when the when the load + + align:start position:0% +this is 4321 is when the when the load + + + align:start position:0% +this is 4321 is when the when the load +is way over at the far left and and it's + + align:start position:0% +is way over at the far left and and it's + + + align:start position:0% +is way over at the far left and and it's +just descending and now now I'm going to + + align:start position:0% +just descending and now now I'm going to + + + align:start position:0% +just descending and now now I'm going to +let me show you how I write it in so I I + + align:start position:0% +let me show you how I write it in so I I + + + align:start position:0% +let me show you how I write it in so I I +pay attention here to the diagonal so + + align:start position:0% +pay attention here to the diagonal so + + + align:start position:0% +pay attention here to the diagonal so +this will be + + align:start position:0% + + + + align:start position:0% + +33 2 + + align:start position:0% +33 2 + + + align:start position:0% +33 2 +1 do you see that the this is the this + + align:start position:0% +1 do you see that the this is the this + + + align:start position:0% +1 do you see that the this is the this +is that's the solution that's sort of + + align:start position:0% +is that's the solution that's sort of + + + align:start position:0% +is that's the solution that's sort of +like this + + align:start position:0% +like this + + + align:start position:0% +like this +one that's the second column of the + + align:start position:0% +one that's the second column of the + + + align:start position:0% +one that's the second column of the +inverse so it's solving I'm solving TT + + align:start position:0% +inverse so it's solving I'm solving TT + + + align:start position:0% +inverse so it's solving I'm solving TT +inverse equal I here it's the the second + + align:start position:0% +inverse equal I here it's the the second + + + align:start position:0% +inverse equal I here it's the the second +column is the guy with a one in the + + align:start position:0% +column is the guy with a one in the + + + align:start position:0% +column is the guy with a one in the +second place so it's so that's where the + + align:start position:0% +second place so it's so that's where the + + + align:start position:0% +second place so it's so that's where the +load is in position number two so I'm + + align:start position:0% +load is in position number two so I'm + + + align:start position:0% +load is in position number two so I'm +level 33 up to that load and then I'm + + align:start position:0% +level 33 up to that load and then I'm + + + align:start position:0% +level 33 up to that load and then I'm +dropping at I'm dropping after the load + + align:start position:0% +dropping at I'm dropping after the load + + + align:start position:0% +dropping at I'm dropping after the load +okay what's the what's the third column + + align:start position:0% +okay what's the what's the third column + + + align:start position:0% +okay what's the what's the third column +of T + + align:start position:0% +of T + + + align:start position:0% +of T +inverse so the third column I started + + align:start position:0% +inverse so the third column I started + + + align:start position:0% +inverse so the third column I started +with that First Column and I knew that + + align:start position:0% +with that First Column and I knew that + + + align:start position:0% +with that First Column and I knew that +the answer would be symmetric because T + + align:start position:0% +the answer would be symmetric because T + + + align:start position:0% +the answer would be symmetric because T +is symmetric so that allowed me to write + + align:start position:0% +is symmetric so that allowed me to write + + + align:start position:0% +is symmetric so that allowed me to write +the first row and now we can fill in the + + align:start position:0% +the first row and now we can fill in the + + + align:start position:0% +the first row and now we can fill in the +rest so what do you think if the point + + align:start position:0% +rest so what do you think if the point + + + align:start position:0% +rest so what do you think if the point +load is now I'm looking at the third + + align:start position:0% +load is now I'm looking at the third + + + align:start position:0% +load is now I'm looking at the third +column third column of the identity the + + align:start position:0% +column third column of the identity the + + + align:start position:0% +column third column of the identity the +load is moved down to position number + + align:start position:0% +load is moved down to position number + + + align:start position:0% +load is moved down to position number +three so what do I have there and there + + align:start position:0% +three so what do I have there and there + + + align:start position:0% +three so what do I have there and there +two and two and what do I have + + align:start position:0% +two and two and what do I have + + + align:start position:0% +two and two and what do I have +last one it's dropping to zero you could + + align:start position:0% +last one it's dropping to zero you could + + + align:start position:0% +last one it's dropping to zero you could +put zero and green here if you wanted + + align:start position:0% +put zero and green here if you wanted + + + align:start position:0% +put zero and green here if you wanted +zero is the is the + + align:start position:0% +zero is the is the + + + align:start position:0% +zero is the is the +Unseen last boundary you know a row at + + align:start position:0% +Unseen last boundary you know a row at + + + align:start position:0% +Unseen last boundary you know a row at +at at this end okay and finally What's + + align:start position:0% +at at this end okay and finally What's + + + align:start position:0% +at at this end okay and finally What's +Happening Here what what do I get from + + align:start position:0% +Happening Here what what do I get from + + + align:start position:0% +Happening Here what what do I get from +from + + align:start position:0% +from + + + align:start position:0% +from +that all one one one to the diagonal and + + align:start position:0% +that all one one one to the diagonal and + + + align:start position:0% +that all one one one to the diagonal and +then sure enough it drops to zero so + + align:start position:0% +then sure enough it drops to zero so + + + align:start position:0% +then sure enough it drops to zero so +this would be a case where the load is + + align:start position:0% +this would be a case where the load is + + + align:start position:0% +this would be a case where the load is +there it would be one one one one and + + align:start position:0% +there it would be one one one one and + + + align:start position:0% +there it would be one one one one and +then + + align:start position:0% +then + + + align:start position:0% +then +boom no it wouldn't be it'd be more like + + align:start position:0% +boom no it wouldn't be it'd be more like + + + align:start position:0% +boom no it wouldn't be it'd be more like +this one one one one and then down to Z + + align:start position:0% +this one one one one and then down to Z + + + align:start position:0% +this one one one one and then down to Z +to to + + align:start position:0% +to to + + + align:start position:0% +to to +okay that's a pretty clean in + + align:start position:0% +okay that's a pretty clean in + + + align:start position:0% +okay that's a pretty clean in +inverse that's a very beautiful + + align:start position:0% +inverse that's a very beautiful + + + align:start position:0% +inverse that's a very beautiful +Matrix don't you admire that Matrix I + + align:start position:0% +Matrix don't you admire that Matrix I + + + align:start position:0% +Matrix don't you admire that Matrix I +mean if they were all like that gee this + + align:start position:0% +mean if they were all like that gee this + + + align:start position:0% +mean if they were all like that gee this +would be a great world uh but uh uh of + + align:start position:0% +would be a great world uh but uh uh of + + + align:start position:0% +would be a great world uh but uh uh of +course um it's not + + align:start position:0% +course um it's not + + + align:start position:0% +course um it's not +sparse and and you have to face the + + align:start position:0% +sparse and and you have to face the + + + align:start position:0% +sparse and and you have to face the +that's why we don't often use the + + align:start position:0% +that's why we don't often use the + + + align:start position:0% +that's why we don't often use the +inverse because we had a sparse Matrix T + + align:start position:0% +inverse because we had a sparse Matrix T + + + align:start position:0% +inverse because we had a sparse Matrix T +that was really fast to compute with and + + align:start position:0% +that was really fast to compute with and + + + align:start position:0% +that was really fast to compute with and +here if I if you tell me the inverse + + align:start position:0% +here if I if you tell me the inverse + + + align:start position:0% +here if I if you tell me the inverse +you've actually slowed me down because + + align:start position:0% +you've actually slowed me down because + + + align:start position:0% +you've actually slowed me down because +I've I you've given me now a a dense + + align:start position:0% +I've I you've given me now a a dense + + + align:start position:0% +I've I you've given me now a a dense +Matrix no zeros even and uh uh U + + align:start position:0% +Matrix no zeros even and uh uh U + + + align:start position:0% +Matrix no zeros even and uh uh U +multiplying T inverse times the right + + align:start position:0% +multiplying T inverse times the right + + + align:start position:0% +multiplying T inverse times the right +side would be slower than just doing + + align:start position:0% +side would be slower than just doing + + + align:start position:0% +side would be slower than just doing +elimination okay now this is the kind of + + align:start position:0% +elimination okay now this is the kind of + + + align:start position:0% +elimination okay now this is the kind of +more interesting one because this is the + + align:start position:0% +more interesting one because this is the + + + align:start position:0% +more interesting one because this is the +one that has to go up to the diagonal + + align:start position:0% +one that has to go up to the diagonal + + + align:start position:0% +one that has to go up to the diagonal +and then down so so let me can I fill + + align:start position:0% +and then down so so let me can I fill + + + align:start position:0% +and then down so so let me can I fill +fill in what I think this the way this + + align:start position:0% +fill in what I think this the way this + + + align:start position:0% +fill in what I think this the way this +one goes I'm going upwards to the + + align:start position:0% +one goes I'm going upwards to the + + + align:start position:0% +one goes I'm going upwards to the +diagonal and then I'm coming down to + + align:start position:0% +diagonal and then I'm coming down to + + + align:start position:0% +diagonal and then I'm coming down to +zero remember that I'm coming down to + + align:start position:0% +zero remember that I'm coming down to + + + align:start position:0% +zero remember that I'm coming down to +zero on this K so 0 0 z0 is kind of the + + align:start position:0% +zero on this K so 0 0 z0 is kind of the + + + align:start position:0% +zero on this K so 0 0 z0 is kind of the +row number if that's row number zero + + align:start position:0% +row number if that's row number zero + + + align:start position:0% +row number if that's row number zero +here's one two three four the real + + align:start position:0% +here's one two three four the real + + + align:start position:0% +here's one two three four the real +things and then row five is is uh + + align:start position:0% +things and then row five is is uh + + + align:start position:0% +things and then row five is is uh +getting back to zero again okay so what + + align:start position:0% +getting back to zero again okay so what + + + align:start position:0% +getting back to zero again okay so what +do you think finish the rest of that + + align:start position:0% +do you think finish the rest of that + + + align:start position:0% +do you think finish the rest of that +column so you're telling me now the + + align:start position:0% +column so you're telling me now the + + + align:start position:0% +column so you're telling me now the +response to the load in position two so + + align:start position:0% +response to the load in position two so + + + align:start position:0% +response to the load in position two so +it's going to look like this + + align:start position:0% +it's going to look like this + + + align:start position:0% +it's going to look like this +in fact it's going to look very like + + align:start position:0% +in fact it's going to look very like + + + align:start position:0% +in fact it's going to look very like +this it'll be there's the three and then + + align:start position:0% +this it'll be there's the three and then + + + align:start position:0% +this it'll be there's the three and then +this is in position two and then I'm + + align:start position:0% +this is in position two and then I'm + + + align:start position:0% +this is in position two and then I'm +going to have something here and + + align:start position:0% +going to have something here and + + + align:start position:0% +going to have something here and +something here and it'll drop to + + align:start position:0% +something here and it'll drop to + + + align:start position:0% +something here and it'll drop to +zero what do I get + + align:start position:0% +zero what do I get + + + align:start position:0% +zero what do I get +42 6 4 2 zero it's dropping to zero okay + + align:start position:0% +42 6 4 2 zero it's dropping to zero okay + + + align:start position:0% +42 6 4 2 zero it's dropping to zero okay +I'm going to finish this in but then I'm + + align:start position:0% +I'm going to finish this in but then I'm + + + align:start position:0% +I'm going to finish this in but then I'm +going to look back and see have I have I + + align:start position:0% +going to look back and see have I have I + + + align:start position:0% +going to look back and see have I have I +really got it right okay how does this + + align:start position:0% +really got it right okay how does this + + + align:start position:0% +really got it right okay how does this +how does this go now two + + align:start position:0% +how does this go now two + + + align:start position:0% +how does this go now two +let's see it's now it's going up from 0 + + align:start position:0% +let's see it's now it's going up from 0 + + + align:start position:0% +let's see it's now it's going up from 0 +to two to four to six that's on the + + align:start position:0% +to two to four to six that's on the + + + align:start position:0% +to two to four to six that's on the +diagonal now it starts down it's got to + + align:start position:0% +diagonal now it starts down it's got to + + + align:start position:0% +diagonal now it starts down it's got to +get to zero so that'll be a + + align:start position:0% +get to zero so that'll be a + + + align:start position:0% +get to zero so that'll be a +three here's a one going up two to three + + align:start position:0% +three here's a one going up two to three + + + align:start position:0% +three here's a one going up two to three +to four is that right and then drop fast + + align:start position:0% +to four is that right and then drop fast + + + align:start position:0% +to four is that right and then drop fast +to zero is that + + align:start position:0% +to zero is that + + + align:start position:0% +to zero is that +correct I think so yep + + align:start position:0% +correct I think so yep + + + align:start position:0% +correct I think so yep +except what wait a minute now okay we + + align:start position:0% +except what wait a minute now okay we + + + align:start position:0% +except what wait a minute now okay we +we've got the right overall picture + + align:start position:0% +we've got the right overall picture + + + align:start position:0% +we've got the right overall picture +climbing up dropping down climbing up + + align:start position:0% +climbing up dropping down climbing up + + + align:start position:0% +climbing up dropping down climbing up +dropping down climbing up dropping down + + align:start position:0% +dropping down climbing up dropping down + + + align:start position:0% +dropping down climbing up dropping down +all good + + align:start position:0% + + + + align:start position:0% + +but we haven't yet got we haven't + + align:start position:0% +but we haven't yet got we haven't + + + align:start position:0% +but we haven't yet got we haven't +checked yet that the change in the + + align:start position:0% +checked yet that the change in the + + + align:start position:0% +checked yet that the change in the +slope was is supposed to be + + align:start position:0% +slope was is supposed to be + + + align:start position:0% +slope was is supposed to be +one and it's not here the slope is like + + align:start position:0% +one and it's not here the slope is like + + + align:start position:0% +one and it's not here the slope is like +three it's going up by threes and and + + align:start position:0% +three it's going up by threes and and + + + align:start position:0% +three it's going up by threes and and +then it's going down by + + align:start position:0% + + + + align:start position:0% + +twos so we we we've gone from going up + + align:start position:0% +twos so we we we've gone from going up + + + align:start position:0% +twos so we we we've gone from going up +at a slope of three to down to a slope + + align:start position:0% +at a slope of three to down to a slope + + + align:start position:0% +at a slope of three to down to a slope +of two like up three down just like this + + align:start position:0% +of two like up three down just like this + + + align:start position:0% +of two like up three down just like this +but that would be a change in slope of + + align:start position:0% +but that would be a change in slope of + + + align:start position:0% +but that would be a change in slope of +five therefore there's a + + align:start position:0% +five therefore there's a + + + align:start position:0% +five therefore there's a +1 so this is going up with a slope of + + align:start position:0% +1 so this is going up with a slope of + + + align:start position:0% +1 so this is going up with a slope of +four and down with a slope of one four + + align:start position:0% +four and down with a slope of one four + + + align:start position:0% +four and down with a slope of one four +dropping to one when I divide by the + + align:start position:0% +dropping to one when I divide by the + + + align:start position:0% +dropping to one when I divide by the +five that's what I like here's up by + + align:start position:0% +five that's what I like here's up by + + + align:start position:0% +five that's what I like here's up by +twos down by threes again it's a change + + align:start position:0% +twos down by threes again it's a change + + + align:start position:0% +twos down by threes again it's a change +of five so I need the five up by ones + + align:start position:0% +of five so I need the five up by ones + + + align:start position:0% +of five so I need the five up by ones +down by four sudden that's a fast drop + + align:start position:0% +down by four sudden that's a fast drop + + + align:start position:0% +down by four sudden that's a fast drop +of four again the slope Changed by five + + align:start position:0% +of four again the slope Changed by five + + + align:start position:0% +of four again the slope Changed by five +dividing by five that's got it so that's + + align:start position:0% +dividing by five that's got it so that's + + + align:start position:0% +dividing by five that's got it so that's +my picture you could now create K + + align:start position:0% +my picture you could now create K + + + align:start position:0% +my picture you could now create K +inverse for any size and more than that + + align:start position:0% +inverse for any size and more than that + + + align:start position:0% +inverse for any size and more than that +sort of C into the into K inverse + + align:start position:0% +sort of C into the into K inverse + + + align:start position:0% +sort of C into the into K inverse +what's you know what what those numbers + + align:start position:0% +what's you know what what those numbers + + + align:start position:0% +what's you know what what those numbers +are because if I wrote the 5x5 or + + align:start position:0% +are because if I wrote the 5x5 or + + + align:start position:0% +are because if I wrote the 5x5 or +6x6 uh without uh doing at a column at a + + align:start position:0% +6x6 uh without uh doing at a column at a + + + align:start position:0% +6x6 uh without uh doing at a column at a +time it would look like a bunch of + + align:start position:0% +time it would look like a bunch of + + + align:start position:0% +time it would look like a bunch of +numbers but uh you you see it now do you + + align:start position:0% +numbers but uh you you see it now do you + + + align:start position:0% +numbers but uh you you see it now do you +see the you see the pattern right okay + + align:start position:0% +see the you see the pattern right okay + + + align:start position:0% +see the you see the pattern right okay +uh so that's what I I I that this is one + + align:start position:0% +uh so that's what I I I that this is one + + + align:start position:0% +uh so that's what I I I that this is one +way to get to those inverses and + + align:start position:0% +way to get to those inverses and + + + align:start position:0% +way to get to those inverses and +homework problems are offering other + + align:start position:0% +homework problems are offering other + + + align:start position:0% +homework problems are offering other +ways T in particular is + + align:start position:0% +ways T in particular is + + + align:start position:0% +ways T in particular is +quite easy to + + align:start position:0% +quite easy to + + + align:start position:0% +quite easy to +invert okay do I have any other comment + + align:start position:0% +invert okay do I have any other comment + + + align:start position:0% +invert okay do I have any other comment +on inverses before the lecture on igen + + align:start position:0% +on inverses before the lecture on igen + + + align:start position:0% +on inverses before the lecture on igen +values really starts maybe I do have one + + align:start position:0% +values really starts maybe I do have one + + + align:start position:0% +values really starts maybe I do have one +comment one important + + align:start position:0% +comment one important + + + align:start position:0% +comment one important +comment it's this and I won't develop it + + align:start position:0% +comment it's this and I won't develop it + + + align:start position:0% +comment it's this and I won't develop it +in full but let let's just say + + align:start position:0% +in full but let let's just say + + + align:start position:0% +in full but let let's just say +it what if the load is not a Delta + + align:start position:0% +it what if the load is not a Delta + + + align:start position:0% +it what if the load is not a Delta +function what if have other loads uh + + align:start position:0% +function what if have other loads uh + + + align:start position:0% +function what if have other loads uh +like the uniform load of all ones or any + + align:start position:0% +like the uniform load of all ones or any + + + align:start position:0% +like the uniform load of all ones or any +other load what if the discret load here + + align:start position:0% +other load what if the discret load here + + + align:start position:0% +other load what if the discret load here +is not a Delta Vector is not I now know + + align:start position:0% +is not a Delta Vector is not I now know + + + align:start position:0% +is not a Delta Vector is not I now know +the response yeah here here's it way I + + align:start position:0% +the response yeah here here's it way I + + + align:start position:0% +the response yeah here here's it way I +now know the responses to each column of + + align:start position:0% +now know the responses to each column of + + + align:start position:0% +now know the responses to each column of +the identity right if I put a load in + + align:start position:0% +the identity right if I put a load in + + + align:start position:0% +the identity right if I put a load in +position one there's the response if I + + align:start position:0% +position one there's the response if I + + + align:start position:0% +position one there's the response if I +put a load in position two there's the + + align:start position:0% +put a load in position two there's the + + + align:start position:0% +put a load in position two there's the +response now what if I have other + + align:start position:0% +response now what if I have other + + + align:start position:0% +response now what if I have other +loads what if let me take a typical load + + align:start position:0% +loads what if let me take a typical load + + + align:start position:0% +loads what if let me take a typical load +what if the load was well the one we + + align:start position:0% +what if the load was well the one we + + + align:start position:0% +what if the load was well the one we +looked at before if the load was 11 one1 + + align:start position:0% +looked at before if the load was 11 one1 + + + align:start position:0% +looked at before if the load was 11 one1 +so that I had + + align:start position:0% +so that I had + + + align:start position:0% +so that I had +um the the bar was hanging by its own + + align:start position:0% +um the the bar was hanging by its own + + + align:start position:0% +um the the bar was hanging by its own +weight let's say uh + + align:start position:0% +weight let's say uh + + + align:start position:0% +weight let's say uh +so in in other words could I could I + + align:start position:0% +so in in other words could I could I + + + align:start position:0% +so in in other words could I could I +solve could I solve all problems by + + align:start position:0% +solve could I solve all problems by + + + align:start position:0% +solve could I solve all problems by +knowing these answers that that's the + + align:start position:0% +knowing these answers that that's the + + + align:start position:0% +knowing these answers that that's the +what I'm trying to get to if I know + + align:start position:0% +what I'm trying to get to if I know + + + align:start position:0% +what I'm trying to get to if I know +these special Delta loads then can I get + + align:start position:0% +these special Delta loads then can I get + + + align:start position:0% +these special Delta loads then can I get +the solution for every + + align:start position:0% +the solution for every + + + align:start position:0% +the solution for every +load yes no what do you think yes right + + align:start position:0% +load yes no what do you think yes right + + + align:start position:0% +load yes no what do you think yes right +okay now with this matrix it's kind of + + align:start position:0% +okay now with this matrix it's kind of + + + align:start position:0% +okay now with this matrix it's kind of +easy to see because if you know the + + align:start position:0% +easy to see because if you know the + + + align:start position:0% +easy to see because if you know the +inverse Matrix well you're obviously in + + align:start position:0% +inverse Matrix well you're obviously in + + + align:start position:0% +inverse Matrix well you're obviously in +business if I had another + + align:start position:0% +business if I had another + + + align:start position:0% +business if I had another +load say another load f for load + + align:start position:0% +load say another load f for load + + + align:start position:0% +load say another load f for load +I would just multiply by K inverse no + + align:start position:0% +I would just multiply by K inverse no + + + align:start position:0% +I would just multiply by K inverse no +problem but I want to look a little + + align:start position:0% +problem but I want to look a little + + + align:start position:0% +problem but I want to look a little +deeper because how I mean if I had other + + align:start position:0% +deeper because how I mean if I had other + + + align:start position:0% +deeper because how I mean if I had other +loads here than a Delta function if I + + align:start position:0% +loads here than a Delta function if I + + + align:start position:0% +loads here than a Delta function if I +had obviously if I had two Delta + + align:start position:0% +had obviously if I had two Delta + + + align:start position:0% +had obviously if I had two Delta +functions I could just combine the two + + align:start position:0% +functions I could just combine the two + + + align:start position:0% +functions I could just combine the two +solutions that's linearity that we're + + align:start position:0% +solutions that's linearity that we're + + + align:start position:0% +solutions that's linearity that we're +using all the time if I had 10 Delta + + align:start position:0% +using all the time if I had 10 Delta + + + align:start position:0% +using all the time if I had 10 Delta +functions I could combine them but then + + align:start position:0% +functions I could combine them but then + + + align:start position:0% +functions I could combine them but then +suppose I had a uh instead of a bunch of + + align:start position:0% +suppose I had a uh instead of a bunch of + + + align:start position:0% +suppose I had a uh instead of a bunch of +spikes it's a bunch of Point loads I had + + align:start position:0% +spikes it's a bunch of Point loads I had + + + align:start position:0% +spikes it's a bunch of Point loads I had +a distributed load like all ones how + + align:start position:0% +a distributed load like all ones how + + + align:start position:0% +a distributed load like all ones how +could I do it okay main point is I could + + align:start position:0% +could I do it okay main point is I could + + + align:start position:0% +could I do it okay main point is I could +right if I know these answers I know all + + align:start position:0% +right if I know these answers I know all + + + align:start position:0% +right if I know these answers I know all +answers if I know the response at to a + + align:start position:0% +answers if I know the response at to a + + + align:start position:0% +answers if I know the response at to a +load at each point then okay come back + + align:start position:0% +load at each point then okay come back + + + align:start position:0% +load at each point then okay come back +to the discrete one how would you what + + align:start position:0% +to the discrete one how would you what + + + align:start position:0% +to the discrete one how would you what +would be the answer if the load was one + + align:start position:0% +would be the answer if the load was one + + + align:start position:0% +would be the answer if the load was one +one one suppose suppose I now tried to + + align:start position:0% +one one suppose suppose I now tried to + + + align:start position:0% +one one suppose suppose I now tried to +solve the equation k u equal ones of + + align:start position:0% +solve the equation k u equal ones of + + + align:start position:0% +solve the equation k u equal ones of +four ones of four and one so so all + + align:start position:0% +four ones of four and one so so all + + + align:start position:0% +four ones of four and one so so all +ones what would be the answer how would + + align:start position:0% +ones what would be the answer how would + + + align:start position:0% +ones what would be the answer how would +I get + + align:start position:0% +I get + + + align:start position:0% +I get +it I would just add the + + align:start position:0% +it I would just add the + + + align:start position:0% +it I would just add the +columns now why would I do + + align:start position:0% + + + + align:start position:0% + +that right because this the right hand + + align:start position:0% +that right because this the right hand + + + align:start position:0% +that right because this the right hand +side the input is the sum of the four + + align:start position:0% +side the input is the sum of the four + + + align:start position:0% +side the input is the sum of the four +columns the four special inputs so the + + align:start position:0% +columns the four special inputs so the + + + align:start position:0% +columns the four special inputs so the +output is the sum of the four outputs + + align:start position:0% +output is the sum of the four outputs + + + align:start position:0% +output is the sum of the four outputs +right in other words as you saw we must + + align:start position:0% +right in other words as you saw we must + + + align:start position:0% +right in other words as you saw we must +know everything and that's the way we + + align:start position:0% +know everything and that's the way we + + + align:start position:0% +know everything and that's the way we +really know it from by linearity if the + + align:start position:0% +really know it from by linearity if the + + + align:start position:0% +really know it from by linearity if the +input is a combination of these the + + align:start position:0% +input is a combination of these the + + + align:start position:0% +input is a combination of these the +output is the same combination of those + + align:start position:0% +output is the same combination of those + + + align:start position:0% +output is the same combination of those +right so for example in this T case if + + align:start position:0% +right so for example in this T case if + + + align:start position:0% +right so for example in this T case if +the input was if I did tuu equal that + + align:start position:0% +the input was if I did tuu equal that + + + align:start position:0% +the input was if I did tuu equal that +ones + + align:start position:0% +ones + + + align:start position:0% +ones +I would just add those and the output + + align:start position:0% +I would just add those and the output + + + align:start position:0% +I would just add those and the output +would be + + align:start position:0% +would be + + + align:start position:0% +would be + + align:start position:0% + + + align:start position:0% +74 that would be the output from + + align:start position:0% +74 that would be the output from + + + align:start position:0% +74 that would be the output from +1111 and now oh + + align:start position:0% +1111 and now oh + + + align:start position:0% +1111 and now oh +boy + + align:start position:0% +boy + + + align:start position:0% +boy +uh yeah I may I + + align:start position:0% + + + + align:start position:0% + +may actually let me just say let me just + + align:start position:0% +may actually let me just say let me just + + + align:start position:0% +may actually let me just say let me just +introduce a guy's name for this for + + align:start position:0% +introduce a guy's name for this for + + + align:start position:0% +introduce a guy's name for this for +these Solutions and not today + + align:start position:0% +these Solutions and not today + + + align:start position:0% +these Solutions and not today +show you you you have the idea of course + + align:start position:0% +show you you you have the idea of course + + + align:start position:0% +show you you you have the idea of course +here we added because everything was + + align:start position:0% +here we added because everything was + + + align:start position:0% +here we added because everything was +discreet so you know what we're going to + + align:start position:0% +discreet so you know what we're going to + + + align:start position:0% +discreet so you know what we're going to +do over here we'll take integrals right + + align:start position:0% +do over here we'll take integrals right + + + align:start position:0% +do over here we'll take integrals right +if if a general load will be an integral + + align:start position:0% +if if a general load will be an integral + + + align:start position:0% +if if a general load will be an integral +over Point + + align:start position:0% +over Point + + + align:start position:0% +over Point +loads that's the that's the idea a + + align:start position:0% +loads that's the that's the idea a + + + align:start position:0% +loads that's the that's the idea a +fundamental idea that some other + + align:start position:0% +fundamental idea that some other + + + align:start position:0% +fundamental idea that some other +load f ofx is an inte + + align:start position:0% +load f ofx is an inte + + + align:start position:0% +load f ofx is an inte +of these guys so that the solution will + + align:start position:0% +of these guys so that the solution will + + + align:start position:0% +of these guys so that the solution will +be the same integral of these guys let + + align:start position:0% +be the same integral of these guys let + + + align:start position:0% +be the same integral of these guys let +me not go there except to tell you the + + align:start position:0% +me not go there except to tell you the + + + align:start position:0% +me not go there except to tell you the +name because it's a very famous name + + align:start position:0% +name because it's a very famous name + + + align:start position:0% +name because it's a very famous name +this solution U with the Delta function + + align:start position:0% +this solution U with the Delta function + + + align:start position:0% +this solution U with the Delta function +is called the greens function so I've + + align:start position:0% +is called the greens function so I've + + + align:start position:0% +is called the greens function so I've +now introduced the idea this this is the + + align:start position:0% +now introduced the idea this this is the + + + align:start position:0% +now introduced the idea this this is the +greens function this guy is the greens + + align:start position:0% +greens function this guy is the greens + + + align:start position:0% +greens function this guy is the greens +function for the fix fixed problem + + align:start position:0% + + + + align:start position:0% + +and this sky is the green function for + + align:start position:0% +and this sky is the green function for + + + align:start position:0% +and this sky is the green function for +the freefix + + align:start position:0% +the freefix + + + align:start position:0% +the freefix +problem and the whole point is maybe + + align:start position:0% +problem and the whole point is maybe + + + align:start position:0% +problem and the whole point is maybe +this is the one point I want you to sort + + align:start position:0% +this is the one point I want you to sort + + + align:start position:0% +this is the one point I want you to sort +of see Always by analogy the green + + align:start position:0% +of see Always by analogy the green + + + align:start position:0% +of see Always by analogy the green +function is just like the inverse + + align:start position:0% +function is just like the inverse + + + align:start position:0% +function is just like the inverse +knowing the green function is what is + + align:start position:0% +knowing the green function is what is + + + align:start position:0% +knowing the green function is what is +the green function the green function is + + align:start position:0% +the green function the green function is + + + align:start position:0% +the green function the green function is +the response at X to a the U at X when + + align:start position:0% +the response at X to a the U at X when + + + align:start position:0% +the response at X to a the U at X when +the input when the impulse is at a so it + + align:start position:0% +the input when the impulse is at a so it + + + align:start position:0% +the input when the impulse is at a so it +sort of depends on two things it depends + + align:start position:0% +sort of depends on two things it depends + + + align:start position:0% +sort of depends on two things it depends +on the position a of the input and it + + align:start position:0% +on the position a of the input and it + + + align:start position:0% +on the position a of the input and it +tells you the response at position X so + + align:start position:0% +tells you the response at position X so + + + align:start position:0% +tells you the response at position X so +the green function has and and often we + + align:start position:0% +the green function has and and often we + + + align:start position:0% +the green function has and and often we +would use the word the letter G for + + align:start position:0% +would use the word the letter G for + + + align:start position:0% +would use the word the letter G for +green okay so it it's a it it it depends + + align:start position:0% +green okay so it it's a it it it depends + + + align:start position:0% +green okay so it it's a it it it depends +on X and A and maybe I'm happy if you + + align:start position:0% +on X and A and maybe I'm happy if you + + + align:start position:0% +on X and A and maybe I'm happy if you +just sort of see yeah in some way + + align:start position:0% +just sort of see yeah in some way + + + align:start position:0% +just sort of see yeah in some way +what we did there is just like what we + + align:start position:0% +what we did there is just like what we + + + align:start position:0% +what we did there is just like what we +did here and therefore the greens + + align:start position:0% +did here and therefore the greens + + + align:start position:0% +did here and therefore the greens +function must be just the + + align:start position:0% +function must be just the + + + align:start position:0% +function must be just the +differential continuous version of a + + align:start position:0% +differential continuous version of a + + + align:start position:0% +differential continuous version of a +inverse + + align:start position:0% +inverse + + + align:start position:0% +inverse +Matrix I'm I'm let's let's uh move on to + + align:start position:0% +Matrix I'm I'm let's let's uh move on to + + + align:start position:0% +Matrix I'm I'm let's let's uh move on to +Icon values with this with that point + + align:start position:0% +Icon values with this with that point + + + align:start position:0% +Icon values with this with that point +sort of made but not driven home by many + + align:start position:0% +sort of made but not driven home by many + + + align:start position:0% +sort of made but not driven home by many +many examples okay + + align:start position:0% +many examples okay + + + align:start position:0% +many examples okay +question I'll take a question sure + + align:start position:0% + + + + align:start position:0% + +yeah y why did why did I increase 036 + + align:start position:0% +yeah y why did why did I increase 036 + + + align:start position:0% +yeah y why did why did I increase 036 +and then decrease + + align:start position:0% +and then decrease + + + align:start position:0% +and then decrease +six well it it's it's intuitively it's + + align:start position:0% +six well it it's it's intuitively it's + + + align:start position:0% +six well it it's it's intuitively it's +because this is copying this + + align:start position:0% +because this is copying this + + + align:start position:0% +because this is copying this +what's wonderful is that it's a perfect + + align:start position:0% +what's wonderful is that it's a perfect + + + align:start position:0% +what's wonderful is that it's a perfect +cup I mean intuitively the solution to + + align:start position:0% +cup I mean intuitively the solution to + + + align:start position:0% +cup I mean intuitively the solution to +our to our difference equation should be + + align:start position:0% +our to our difference equation should be + + + align:start position:0% +our to our difference equation should be +like the solution to our differential + + align:start position:0% +like the solution to our differential + + + align:start position:0% +like the solution to our differential +equation that's why + + align:start position:0% +equation that's why + + + align:start position:0% +equation that's why +we if we have some computation or some + + align:start position:0% +we if we have some computation or some + + + align:start position:0% +we if we have some computation or some +differential equation that we can't + + align:start position:0% +differential equation that we can't + + + align:start position:0% +differential equation that we can't +solve which would be much more typical + + align:start position:0% +solve which would be much more typical + + + align:start position:0% +solve which would be much more typical +than this one that we couldn't solve it + + align:start position:0% +than this one that we couldn't solve it + + + align:start position:0% +than this one that we couldn't solve it +exactly by pencil and paper we would go + + align:start position:0% +exactly by pencil and paper we would go + + + align:start position:0% +exactly by pencil and paper we would go +to we would replace derivatives by + + align:start position:0% +to we would replace derivatives by + + + align:start position:0% +to we would replace derivatives by +differences and go over here and we + + align:start position:0% +differences and go over here and we + + + align:start position:0% +differences and go over here and we +would hope that they were like you know + + align:start position:0% +would hope that they were like you know + + + align:start position:0% +would hope that they were like you know +pretty close here they're right they're + + align:start position:0% +pretty close here they're right they're + + + align:start position:0% +pretty close here they're right they're +the same + + align:start position:0% + + + + align:start position:0% + +yeah oh the other columns absolutely + + align:start position:0% +yeah oh the other columns absolutely + + + align:start position:0% +yeah oh the other columns absolutely +these guys yeah + + align:start position:0% +these guys yeah + + + align:start position:0% +these guys yeah +0246 going up 630 coming back yeah yeah + + align:start position:0% +0246 going up 630 coming back yeah yeah + + + align:start position:0% +0246 going up 630 coming back yeah yeah +so that's a that's a a discret thing of + + align:start position:0% +so that's a that's a a discret thing of + + + align:start position:0% +so that's a that's a a discret thing of +of one like that and then the next guy + + align:start position:0% +of one like that and then the next guy + + + align:start position:0% +of one like that and then the next guy +and the last guy would be a going up 1 2 + + align:start position:0% +and the last guy would be a going up 1 2 + + + align:start position:0% +and the last guy would be a going up 1 2 +3 4 and then sudden + + align:start position:0% +3 4 and then sudden + + + align:start position:0% +3 4 and then sudden +drop yeah so that's that was thanks for + + align:start position:0% +drop yeah so that's that was thanks for + + + align:start position:0% +drop yeah so that's that was thanks for +all questions I mean this sort of by + + align:start position:0% +all questions I mean this sort of by + + + align:start position:0% +all questions I mean this sort of by +adding these guys in the first one + + align:start position:0% +adding these guys in the first one + + + align:start position:0% +adding these guys in the first one +actually went up that way you see the + + align:start position:0% +actually went up that way you see the + + + align:start position:0% +actually went up that way you see the +greens + + align:start position:0% +greens + + + align:start position:0% +greens +functions but of course this has a + + align:start position:0% +functions but of course this has a + + + align:start position:0% +functions but of course this has a +greens function for every a and you know + + align:start position:0% +greens function for every a and you know + + + align:start position:0% +greens function for every a and you know +X and A are running all the way from + + align:start position:0% +X and A are running all the way from + + + align:start position:0% +X and A are running all the way from +zero to one here they're just discrete + + align:start position:0% +zero to one here they're just discrete + + + align:start position:0% +zero to one here they're just discrete +positions + + align:start position:0% +positions + + + align:start position:0% +positions +thanks other points yeah yeah so so + + align:start position:0% +thanks other points yeah yeah so so + + + align:start position:0% +thanks other points yeah yeah so so +playing with these Delta functions and + + align:start position:0% +playing with these Delta functions and + + + align:start position:0% +playing with these Delta functions and +coming up with this + + align:start position:0% +coming up with this + + + align:start position:0% +coming up with this +solution well as I say different ways to + + align:start position:0% +solution well as I say different ways to + + + align:start position:0% +solution well as I say different ways to +do it uh I work through one way in class + + align:start position:0% +do it uh I work through one way in class + + + align:start position:0% +do it uh I work through one way in class +last time uh it takes practice so that's + + align:start position:0% +last time uh it takes practice so that's + + + align:start position:0% +last time uh it takes practice so that's +what the homework's really for is you + + align:start position:0% +what the homework's really for is you + + + align:start position:0% +what the homework's really for is you +know you can see me come up with this + + align:start position:0% +know you can see me come up with this + + + align:start position:0% +know you can see me come up with this +thing then you can in with Leisure you + + align:start position:0% +thing then you can in with Leisure you + + + align:start position:0% +thing then you can in with Leisure you +can follow those step St but you got to + + align:start position:0% +can follow those step St but you got to + + + align:start position:0% +can follow those step St but you got to +do it yourself to see + + align:start position:0% +do it yourself to see + + + align:start position:0% +do it yourself to see +okay I + + align:start position:0% +okay I + + + align:start position:0% +okay I +values and of course igen vectors we + + align:start position:0% +values and of course igen vectors we + + + align:start position:0% +values and of course igen vectors we +have to give them a fair shot + + align:start position:0% + + + + align:start position:0% + +here + + align:start position:0% +here + + + align:start position:0% +here +okay all right Square + + align:start position:0% +okay all right Square + + + align:start position:0% +okay all right Square +Matrix now so I'm talking about general + + align:start position:0% +Matrix now so I'm talking about general + + + align:start position:0% +Matrix now so I'm talking about general +what IG vectors and igen values are and + + align:start position:0% +what IG vectors and igen values are and + + + align:start position:0% +what IG vectors and igen values are and +why do we want them I'm always trying to + + align:start position:0% +why do we want them I'm always trying to + + + align:start position:0% +why do we want them I'm always trying to +say what's the purpose you know I'm not + + align:start position:0% +say what's the purpose you know I'm not + + + align:start position:0% +say what's the purpose you know I'm not +doing this just for uh abstract L + + align:start position:0% +doing this just for uh abstract L + + + align:start position:0% +doing this just for uh abstract L +algebra that we do this we look for + + align:start position:0% +algebra that we do this we look for + + + align:start position:0% +algebra that we do this we look for +these things because they tremendously + + align:start position:0% +these things because they tremendously + + + align:start position:0% +these things because they tremendously +simplify a problem if we can find + + align:start position:0% +simplify a problem if we can find + + + align:start position:0% +simplify a problem if we can find +them so what's an igen Vector an the + + align:start position:0% +them so what's an igen Vector an the + + + align:start position:0% +them so what's an igen Vector an the +igen value is this number Lambda and the + + align:start position:0% +igen value is this number Lambda and the + + + align:start position:0% +igen value is this number Lambda and the +I Vector is this Vector Y and now how do + + align:start position:0% +I Vector is this Vector Y and now how do + + + align:start position:0% +I Vector is this Vector Y and now how do +you how do I do I think about + + align:start position:0% +you how do I do I think about + + + align:start position:0% +you how do I do I think about +those + + align:start position:0% +those + + + align:start position:0% +those +well suppose I take a vector and I + + align:start position:0% +well suppose I take a vector and I + + + align:start position:0% +well suppose I take a vector and I +multiply by a so the vectors headed off + + align:start position:0% +multiply by a so the vectors headed off + + + align:start position:0% +multiply by a so the vectors headed off +in some direction okay Vector there's a + + align:start position:0% +in some direction okay Vector there's a + + + align:start position:0% +in some direction okay Vector there's a +vector v If I multiply and I'm given + + align:start position:0% +vector v If I multiply and I'm given + + + align:start position:0% +vector v If I multiply and I'm given +this Matrix so I'm given the Matrix + + align:start position:0% +this Matrix so I'm given the Matrix + + + align:start position:0% +this Matrix so I'm given the Matrix +whatever my Matrix + + align:start position:0% +whatever my Matrix + + + align:start position:0% +whatever my Matrix +is could be one of those matrices any + + align:start position:0% +is could be one of those matrices any + + + align:start position:0% +is could be one of those matrices any +other Matrix If I multiply that by V I + + align:start position:0% +other Matrix If I multiply that by V I + + + align:start position:0% +other Matrix If I multiply that by V I +get some result AV + + align:start position:0% +get some result AV + + + align:start position:0% +get some result AV +okay what do I do I I look at that and I + + align:start position:0% +okay what do I do I I look at that and I + + + align:start position:0% +okay what do I do I I look at that and I +say that V was not an igen + + align:start position:0% +say that V was not an igen + + + align:start position:0% +say that V was not an igen +Vector I vectors are the special vectors + + align:start position:0% +Vector I vectors are the special vectors + + + align:start position:0% +Vector I vectors are the special vectors +which come out in the same direction AV + + align:start position:0% +which come out in the same direction AV + + + align:start position:0% +which come out in the same direction AV +comes out parallel to V so this was not + + align:start position:0% +comes out parallel to V so this was not + + + align:start position:0% +comes out parallel to V so this was not +an igen Vector that very few vectors are + + align:start position:0% +an igen Vector that very few vectors are + + + align:start position:0% +an igen Vector that very few vectors are +igen vectors they're they're very + + align:start position:0% +igen vectors they're they're very + + + align:start position:0% +igen vectors they're they're very +special most vectors that'll be a + + align:start position:0% +special most vectors that'll be a + + + align:start position:0% +special most vectors that'll be a +typical picture but there's a few of + + align:start position:0% +typical picture but there's a few of + + + align:start position:0% +typical picture but there's a few of +them + + align:start position:0% +them + + + align:start position:0% +them +where I have a vector Y and I multiply + + align:start position:0% +where I have a vector Y and I multiply + + + align:start position:0% +where I have a vector Y and I multiply +by a and then what's the point a y is in + + align:start position:0% +by a and then what's the point a y is in + + + align:start position:0% +by a and then what's the point a y is in +the same direction it's on that same + + align:start position:0% +the same direction it's on that same + + + align:start position:0% +the same direction it's on that same +line as y it could be might it might be + + align:start position:0% +line as y it could be might it might be + + + align:start position:0% +line as y it could be might it might be +twice as far out that would be a yal 2 y + + align:start position:0% +twice as far out that would be a yal 2 y + + + align:start position:0% +twice as far out that would be a yal 2 y +it might go backwards this would be a a + + align:start position:0% +it might go backwards this would be a a + + + align:start position:0% +it might go backwards this would be a a +possibility a y equal minus y + + align:start position:0% +possibility a y equal minus y + + + align:start position:0% +possibility a y equal minus y +it could be just uh halfway it could be + + align:start position:0% +it could be just uh halfway it could be + + + align:start position:0% +it could be just uh halfway it could be +not move at all yeah that's even a + + align:start position:0% +not move at all yeah that's even a + + + align:start position:0% +not move at all yeah that's even a +possibility a y equal z y count that + + align:start position:0% +possibility a y equal z y count that + + + align:start position:0% +possibility a y equal z y count that +those are those those y's and are igen + + align:start position:0% +those are those those y's and are igen + + + align:start position:0% +those are those those y's and are igen +vectors and the igen value is + + align:start position:0% +vectors and the igen value is + + + align:start position:0% +vectors and the igen value is +just from this point of view the I value + + align:start position:0% +just from this point of view the I value + + + align:start position:0% +just from this point of view the I value +is coming second because it's so y was a + + align:start position:0% +is coming second because it's so y was a + + + align:start position:0% +is coming second because it's so y was a +special Vector that kept its direction + + align:start position:0% +special Vector that kept its direction + + + align:start position:0% +special Vector that kept its direction +and then Lambda was just is just the + + align:start position:0% +and then Lambda was just is just the + + + align:start position:0% +and then Lambda was just is just the +number the two the zero the minus1 the2 + + align:start position:0% +number the two the zero the minus1 the2 + + + align:start position:0% +number the two the zero the minus1 the2 +that tells + + align:start position:0% +that tells + + + align:start position:0% +that tells +you um stretching shrinking reversing + + align:start position:0% +you um stretching shrinking reversing + + + align:start position:0% +you um stretching shrinking reversing +whatever that's the number but Y is the + + align:start position:0% +whatever that's the number but Y is the + + + align:start position:0% +whatever that's the number but Y is the +vector and notice that we this you know + + align:start position:0% +vector and notice that we this you know + + + align:start position:0% +vector and notice that we this you know +if I knew + + align:start position:0% +if I knew + + + align:start position:0% +if I knew +why and and I knew it was an igen Vector + + align:start position:0% +why and and I knew it was an igen Vector + + + align:start position:0% +why and and I knew it was an igen Vector +then of course if I multiply by a I'll + + align:start position:0% +then of course if I multiply by a I'll + + + align:start position:0% +then of course if I multiply by a I'll +learn the igen value + + align:start position:0% +learn the igen value + + + align:start position:0% +learn the igen value +and if I knew an igen value you'll see + + align:start position:0% +and if I knew an igen value you'll see + + + align:start position:0% +and if I knew an igen value you'll see +how I could find the igen vector problem + + align:start position:0% +how I could find the igen vector problem + + + align:start position:0% +how I could find the igen vector problem +is you have to find them both and they + + align:start position:0% +is you have to find them both and they + + + align:start position:0% +is you have to find them both and they +multiply each other so we're not talking + + align:start position:0% +multiply each other so we're not talking + + + align:start position:0% +multiply each other so we're not talking +about linear equations anymore because + + align:start position:0% +about linear equations anymore because + + + align:start position:0% +about linear equations anymore because +one unknown is multiplying another but + + align:start position:0% +one unknown is multiplying another but + + + align:start position:0% +one unknown is multiplying another but +we'll find a way to look to discover I + + align:start position:0% +we'll find a way to look to discover I + + + align:start position:0% +we'll find a way to look to discover I +vectors and igen values you see the now + + align:start position:0% +vectors and igen values you see the now + + + align:start position:0% +vectors and igen values you see the now +here's I I said I would try to make + + align:start position:0% +here's I I said I would try to make + + + align:start position:0% +here's I I said I would try to make +clear what's the purpose the purpose + + align:start position:0% +clear what's the purpose the purpose + + + align:start position:0% +clear what's the purpose the purpose +is that in this + + align:start position:0% +is that in this + + + align:start position:0% +is that in this +direction on this y line line of + + align:start position:0% +direction on this y line line of + + + align:start position:0% +direction on this y line line of +multiples of y a is just acting like a + + align:start position:0% +multiples of y a is just acting like a + + + align:start position:0% +multiples of y a is just acting like a +number a is some big n byn thousand by + + align:start position:0% +number a is some big n byn thousand by + + + align:start position:0% +number a is some big n byn thousand by +thousand + + align:start position:0% +thousand + + + align:start position:0% +thousand +Matrix so a Million numbers but on this + + align:start position:0% +Matrix so a Million numbers but on this + + + align:start position:0% +Matrix so a Million numbers but on this +line once if we find it if we find a AN + + align:start position:0% +line once if we find it if we find a AN + + + align:start position:0% +line once if we find it if we find a AN +igen line you could say an igen + + align:start position:0% +igen line you could say an igen + + + align:start position:0% +igen line you could say an igen +Direction on that in that direction a + + align:start position:0% +Direction on that in that direction a + + + align:start position:0% +Direction on that in that direction a +all the complications of a are gone it's + + align:start position:0% +all the complications of a are gone it's + + + align:start position:0% +all the complications of a are gone it's +just acting like a number so in + + align:start position:0% +just acting like a number so in + + + align:start position:0% +just acting like a number so in +particular we could solve a thousand + + align:start position:0% +particular we could solve a thousand + + + align:start position:0% +particular we could solve a thousand +differential + + align:start position:0% +differential + + + align:start position:0% +differential +equations with a thousand unknown U's + + align:start position:0% +equations with a thousand unknown U's + + + align:start position:0% +equations with a thousand unknown U's +with this thousand by, + + align:start position:0% +with this thousand by, + + + align:start position:0% +with this thousand by, +Matrix we could find a solution one we + + align:start position:0% +Matrix we could find a solution one we + + + align:start position:0% +Matrix we could find a solution one we +can find a solution and that's this is + + align:start position:0% +can find a solution and that's this is + + + align:start position:0% +can find a solution and that's this is +where I the igen vector + + align:start position:0% +where I the igen vector + + + align:start position:0% +where I the igen vector +nigen value are going to pay off in for + + align:start position:0% +nigen value are going to pay off in for + + + align:start position:0% +nigen value are going to pay off in for +this this you recognize this Matrix a is + + align:start position:0% +this this you recognize this Matrix a is + + + align:start position:0% +this this you recognize this Matrix a is +a size a thousand so this is and U is a + + align:start position:0% +a size a thousand so this is and U is a + + + align:start position:0% +a size a thousand so this is and U is a +vector of a thousand unknowns so that's + + align:start position:0% +vector of a thousand unknowns so that's + + + align:start position:0% +vector of a thousand unknowns so that's +a system of a thousand equation but if + + align:start position:0% +a system of a thousand equation but if + + + align:start position:0% +a system of a thousand equation but if +we have found an igen vector and it's + + align:start position:0% +we have found an igen vector and it's + + + align:start position:0% +we have found an igen vector and it's +igen value + + align:start position:0% +igen value + + + align:start position:0% +igen value +then the equation will if it starts in + + align:start position:0% +then the equation will if it starts in + + + align:start position:0% +then the equation will if it starts in +that direction it'll stay in that + + align:start position:0% +that direction it'll stay in that + + + align:start position:0% +that direction it'll stay in that +direction and the Matrix will just be + + align:start position:0% +direction and the Matrix will just be + + + align:start position:0% +direction and the Matrix will just be +acting like a number and we know how to + + align:start position:0% +acting like a number and we know how to + + + align:start position:0% +acting like a number and we know how to +solve U Prime equal Lambda U right that + + align:start position:0% +solve U Prime equal Lambda U right that + + + align:start position:0% +solve U Prime equal Lambda U right that +one by one scalar problem we know how to + + align:start position:0% +one by one scalar problem we know how to + + + align:start position:0% +one by one scalar problem we know how to +solve the solution to that is e to the + + align:start position:0% +solve the solution to that is e to the + + + align:start position:0% +solve the solution to that is e to the +Lambda + + align:start position:0% + + + + align:start position:0% + +T and of course it could have a constant + + align:start position:0% +T and of course it could have a constant + + + align:start position:0% +T and of course it could have a constant +in it don't don't forget that that the + + align:start position:0% +in it don't don't forget that that the + + + align:start position:0% +in it don't don't forget that that the +these equations are linear uh If I + + align:start position:0% +these equations are linear uh If I + + + align:start position:0% +these equations are linear uh If I +multiply if I take two e to the Lambda T + + align:start position:0% +multiply if I take two e to the Lambda T + + + align:start position:0% +multiply if I take two e to the Lambda T +I have a two here and a two here and + + align:start position:0% +I have a two here and a two here and + + + align:start position:0% +I have a two here and a two here and +it's just as good so I better allow that + + align:start position:0% +it's just as good so I better allow that + + + align:start position:0% +it's just as good so I better allow that +as + + align:start position:0% + + + + align:start position:0% + +well a constant times e Lambda T * y + + align:start position:0% +well a constant times e Lambda T * y + + + align:start position:0% +well a constant times e Lambda T * y +notice this is a vector it's a number + + align:start position:0% +notice this is a vector it's a number + + + align:start position:0% +notice this is a vector it's a number +times the number the growth so the + + align:start position:0% +times the number the growth so the + + + align:start position:0% +times the number the growth so the +Lambda is now for the differential + + align:start position:0% +Lambda is now for the differential + + + align:start position:0% +Lambda is now for the differential +equation the Lambda this this number + + align:start position:0% +equation the Lambda this this number + + + align:start position:0% +equation the Lambda this this number +Lambda is crucial it's telling us + + align:start position:0% +Lambda is crucial it's telling us + + + align:start position:0% +Lambda is crucial it's telling us +whether the solution grows whether it + + align:start position:0% +whether the solution grows whether it + + + align:start position:0% +whether the solution grows whether it +decays whether it oscillates and we're + + align:start position:0% +decays whether it oscillates and we're + + + align:start position:0% +decays whether it oscillates and we're +just looking at this one normal mode you + + align:start position:0% +just looking at this one normal mode you + + + align:start position:0% +just looking at this one normal mode you +could say normal mode for igen Vector + + align:start position:0% +could say normal mode for igen Vector + + + align:start position:0% +could say normal mode for igen Vector +why we certainly have not + + align:start position:0% +why we certainly have not + + + align:start position:0% +why we certainly have not +found all all possible solutions our uh + + align:start position:0% +found all all possible solutions our uh + + + align:start position:0% +found all all possible solutions our uh +this but this is we found if we if we + + align:start position:0% +this but this is we found if we if we + + + align:start position:0% +this but this is we found if we if we +have an igen Vector we found that one + + align:start position:0% +have an igen Vector we found that one + + + align:start position:0% +have an igen Vector we found that one +okay well so uh and just other uses but + + align:start position:0% +okay well so uh and just other uses but + + + align:start position:0% +okay well so uh and just other uses but +and then let me other uses what so let + + align:start position:0% +and then let me other uses what so let + + + align:start position:0% +and then let me other uses what so let +me write again the fundamental equation + + align:start position:0% +me write again the fundamental equation + + + align:start position:0% +me write again the fundamental equation +a yal Lambda y suppose so that was a + + align:start position:0% +a yal Lambda y suppose so that was a + + + align:start position:0% +a yal Lambda y suppose so that was a +differential + + align:start position:0% +differential + + + align:start position:0% +differential +equation going forward in time now uh if + + align:start position:0% +equation going forward in time now uh if + + + align:start position:0% +equation going forward in time now uh if +we go forward in steps we might multiply + + align:start position:0% +we go forward in steps we might multiply + + + align:start position:0% +we go forward in steps we might multiply +by a at every + + align:start position:0% +by a at every + + + align:start position:0% +by a at every +step so what tell me + + align:start position:0% +step so what tell me + + + align:start position:0% +step so what tell me +what tell me an igon Vector of a s + + align:start position:0% +what tell me an igon Vector of a s + + + align:start position:0% +what tell me an igon Vector of a s +I I'm looking for a vector that doesn't + + align:start position:0% +I I'm looking for a vector that doesn't + + + align:start position:0% +I I'm looking for a vector that doesn't +change direction when I multiply twice + + align:start position:0% +change direction when I multiply twice + + + align:start position:0% +change direction when I multiply twice +by + + align:start position:0% +by + + + align:start position:0% +by +a you're going to tell me it's why why + + align:start position:0% +a you're going to tell me it's why why + + + align:start position:0% +a you're going to tell me it's why why +will work if I multiply once by a I get + + align:start position:0% +will work if I multiply once by a I get + + + align:start position:0% +will work if I multiply once by a I get +Lambda time y when I multiply Again by a + + align:start position:0% +Lambda time y when I multiply Again by a + + + align:start position:0% +Lambda time y when I multiply Again by a +I get Lambda squ time y you see I + + align:start position:0% +I get Lambda squ time y you see I + + + align:start position:0% +I get Lambda squ time y you see I +values are + + align:start position:0% +values are + + + align:start position:0% +values are +great for powers of a matrix for + + align:start position:0% +great for powers of a matrix for + + + align:start position:0% +great for powers of a matrix for +differential + + align:start position:0% +differential + + + align:start position:0% +differential +equations the N power will just take the + + align:start position:0% +equations the N power will just take the + + + align:start position:0% +equations the N power will just take the +igon value to the N the nth power of a + + align:start position:0% +igon value to the N the nth power of a + + + align:start position:0% +igon value to the N the nth power of a +we'll just have Lambda to the nth + + align:start position:0% +we'll just have Lambda to the nth + + + align:start position:0% +we'll just have Lambda to the nth +there uh you know the + + align:start position:0% +there uh you know the + + + align:start position:0% +there uh you know the +pivots of a matrix are all messed up + + align:start position:0% +pivots of a matrix are all messed up + + + align:start position:0% +pivots of a matrix are all messed up +when when I Square it I I can't see + + align:start position:0% +when when I Square it I I can't see + + + align:start position:0% +when when I Square it I I can't see +what's happening with the pivots the + + align:start position:0% +what's happening with the pivots the + + + align:start position:0% +what's happening with the pivots the +igen values are a different way to look + + align:start position:0% +igen values are a different way to look + + + align:start position:0% +igen values are a different way to look +at a matrix the pivots are critical + + align:start position:0% +at a matrix the pivots are critical + + + align:start position:0% +at a matrix the pivots are critical +numbers for steady state problems the + + align:start position:0% +numbers for steady state problems the + + + align:start position:0% +numbers for steady state problems the +igen values are the critical numbers + + align:start position:0% +igen values are the critical numbers + + + align:start position:0% +igen values are the critical numbers +for moving problems dynamic problems + + align:start position:0% +for moving problems dynamic problems + + + align:start position:0% +for moving problems dynamic problems +things are oscillating or growing or + + align:start position:0% +things are oscillating or growing or + + + align:start position:0% +things are oscillating or growing or +decaying okay and by the way let's just + + align:start position:0% +decaying okay and by the way let's just + + + align:start position:0% +decaying okay and by the way let's just +recognize since this is the is the only + + align:start position:0% +recognize since this is the is the only + + + align:start position:0% +recognize since this is the is the only +is the thing that's changing in time + + align:start position:0% +is the thing that's changing in time + + + align:start position:0% +is the thing that's changing in time +what would be the + + align:start position:0% +what would be the + + + align:start position:0% +what would be the +uh I'll just go down here e to the + + align:start position:0% +uh I'll just go down here e to the + + + align:start position:0% +uh I'll just go down here e to the +Lambda T let's just look and see when + + align:start position:0% +Lambda T let's just look and see when + + + align:start position:0% +Lambda T let's just look and see when +would I have + + align:start position:0% +would I have + + + align:start position:0% +would I have +Decay which you might want to call + + align:start position:0% +Decay which you might want to call + + + align:start position:0% +Decay which you might want to call +stability a stable + + align:start position:0% +stability a stable + + + align:start position:0% +stability a stable +problem what would be the condition on + + align:start position:0% +problem what would be the condition on + + + align:start position:0% +problem what would be the condition on +Lambda to get for this to + + align:start position:0% +Lambda to get for this to + + + align:start position:0% +Lambda to get for this to +Decay Lambda less than zero now there's + + align:start position:0% +Decay Lambda less than zero now there's + + + align:start position:0% +Decay Lambda less than zero now there's +one little bit of bad news Lambda could + + align:start position:0% +one little bit of bad news Lambda could + + + align:start position:0% +one little bit of bad news Lambda could +be + + align:start position:0% +be + + + align:start position:0% +be +complex Lambda could + + align:start position:0% +complex Lambda could + + + align:start position:0% +complex Lambda could +be three + 4 + + align:start position:0% +be three + 4 + + + align:start position:0% +be three + 4 +I it it can it can be a complex number + + align:start position:0% +I it it can it can be a complex number + + + align:start position:0% +I it it can it can be a complex number +these I values even + + align:start position:0% +these I values even + + + align:start position:0% +these I values even +if a is + + align:start position:0% +if a is + + + align:start position:0% +if a is +real oh you'll say how' that happen let + + align:start position:0% +real oh you'll say how' that happen let + + + align:start position:0% +real oh you'll say how' that happen let +me see better + + align:start position:0% +me see better + + + align:start position:0% +me see better +think well let me finish this thought + + align:start position:0% +think well let me finish this thought + + + align:start position:0% +think well let me finish this thought +suppose Lambda was 3 + 4 I what would be + + align:start position:0% +suppose Lambda was 3 + 4 I what would be + + + align:start position:0% +suppose Lambda was 3 + 4 I what would be +would it then so I'm thinking about what + + align:start position:0% +would it then so I'm thinking about what + + + align:start position:0% +would it then so I'm thinking about what +would e to the Lambda T do in that case + + align:start position:0% +would e to the Lambda T do in that case + + + align:start position:0% +would e to the Lambda T do in that case +so so this is small example e if if I + + align:start position:0% +so so this is small example e if if I + + + align:start position:0% +so so this is small example e if if I +had Lambda is 3 + 4 i t how what does + + align:start position:0% +had Lambda is 3 + 4 i t how what does + + + align:start position:0% +had Lambda is 3 + 4 i t how what does +that do as time + + align:start position:0% +that do as time + + + align:start position:0% +that do as time +grows it's going to grow and oscillate + + align:start position:0% +grows it's going to grow and oscillate + + + align:start position:0% +grows it's going to grow and oscillate +and what decides the + + align:start position:0% +and what decides the + + + align:start position:0% +and what decides the +growth the real part so it's really the + + align:start position:0% +growth the real part so it's really the + + + align:start position:0% +growth the real part so it's really the +Decay or growth is decided by the real + + align:start position:0% +Decay or growth is decided by the real + + + align:start position:0% +Decay or growth is decided by the real +part the three e to the 3 T that would + + align:start position:0% +part the three e to the 3 T that would + + + align:start position:0% +part the three e to the 3 T that would +be a growth so let me put growth + + align:start position:0% +be a growth so let me put growth + + + align:start position:0% +be a growth so let me put growth +and that would be of course + + align:start position:0% +and that would be of course + + + align:start position:0% +and that would be of course +unstable and that's a problem when I + + align:start position:0% +unstable and that's a problem when I + + + align:start position:0% +unstable and that's a problem when I +have a real part of Lambda bigger than + + align:start position:0% +have a real part of Lambda bigger than + + + align:start position:0% +have a real part of Lambda bigger than +zero and then if if Lambda is has a zero + + align:start position:0% +zero and then if if Lambda is has a zero + + + align:start position:0% +zero and then if if Lambda is has a zero +real part so it's pure oscillation let + + align:start position:0% +real part so it's pure oscillation let + + + align:start position:0% +real part so it's pure oscillation let +me just take a case like that so e to + + align:start position:0% +me just take a case like that so e to + + + align:start position:0% +me just take a case like that so e to +the 4 i + + align:start position:0% +the 4 i + + + align:start position:0% +the 4 i +t so that would be oscillating right + + align:start position:0% +t so that would be oscillating right + + + align:start position:0% +t so that would be oscillating right +yeah it's cos 4T plus I sin 4T it's just + + align:start position:0% +yeah it's cos 4T plus I sin 4T it's just + + + align:start position:0% +yeah it's cos 4T plus I sin 4T it's just +oscillate + + align:start position:0% +oscillate + + + align:start position:0% +oscillate +okay all right so in in this discussion + + align:start position:0% +okay all right so in in this discussion + + + align:start position:0% +okay all right so in in this discussion +we seen uh growth and Decay + + align:start position:0% +we seen uh growth and Decay + + + align:start position:0% +we seen uh growth and Decay +oh tell me the parallels because I'm + + align:start position:0% +oh tell me the parallels because I'm + + + align:start position:0% +oh tell me the parallels because I'm +always shooting for the parallels what + + align:start position:0% +always shooting for the parallels what + + + align:start position:0% +always shooting for the parallels what +about the growth of a what + + align:start position:0% +about the growth of a what + + + align:start position:0% +about the growth of a what +matrices + + align:start position:0% +matrices + + + align:start position:0% +matrices +yeah what how can I recognize a matrix + + align:start position:0% +yeah what how can I recognize a matrix + + + align:start position:0% +yeah what how can I recognize a matrix +whose powers + + align:start position:0% +whose powers + + + align:start position:0% +whose powers +grow how can I recognize a Matrix whose + + align:start position:0% +grow how can I recognize a Matrix whose + + + align:start position:0% +grow how can I recognize a Matrix whose +Powers go to zero so that would be the + + align:start position:0% +Powers go to zero so that would be the + + + align:start position:0% +Powers go to zero so that would be the +I'm asking you for Powers here over + + align:start position:0% +I'm asking you for Powers here over + + + align:start position:0% +I'm asking you for Powers here over +there for exponentials somehow so so + + align:start position:0% +there for exponentials somehow so so + + + align:start position:0% +there for exponentials somehow so so +here would be a a to higher and higher + + align:start position:0% +here would be a a to higher and higher + + + align:start position:0% +here would be a a to higher and higher +Powers goes to zero the zero Matrix in + + align:start position:0% +Powers goes to zero the zero Matrix in + + + align:start position:0% +Powers goes to zero the zero Matrix in +other words when I multiply multiply + + align:start position:0% +other words when I multiply multiply + + + align:start position:0% +other words when I multiply multiply +multiply by that Matrix I get smaller + + align:start position:0% +multiply by that Matrix I get smaller + + + align:start position:0% +multiply by that Matrix I get smaller +and smaller and smaller matrices zero in + + align:start position:0% +and smaller and smaller matrices zero in + + + align:start position:0% +and smaller and smaller matrices zero in +the limit what do you think's the test + + align:start position:0% +the limit what do you think's the test + + + align:start position:0% +the limit what do you think's the test +on the lambdas + + align:start position:0% +on the lambdas + + + align:start position:0% +on the lambdas +now so here's so what are the igen + + align:start position:0% +now so here's so what are the igen + + + align:start position:0% +now so here's so what are the igen +values of a to the + + align:start position:0% +values of a to the + + + align:start position:0% +values of a to the +K let's see if a had IG values Lambda a + + align:start position:0% +K let's see if a had IG values Lambda a + + + align:start position:0% +K let's see if a had IG values Lambda a +s will have IG values Lambda squar a cub + + align:start position:0% +s will have IG values Lambda squar a cub + + + align:start position:0% +s will have IG values Lambda squar a cub +will have IG values Lambda cubed a to + + align:start position:0% +will have IG values Lambda cubed a to + + + align:start position:0% +will have IG values Lambda cubed a to +the thousandth will have I values Lambda + + align:start position:0% +the thousandth will have I values Lambda + + + align:start position:0% +the thousandth will have I values Lambda +to the thousandth and what's the test + + align:start position:0% +to the thousandth and what's the test + + + align:start position:0% +to the thousandth and what's the test +for that to G be getting + + align:start position:0% +for that to G be getting + + + align:start position:0% +for that to G be getting +small Lambda below Lambda less than one + + align:start position:0% +small Lambda below Lambda less than one + + + align:start position:0% +small Lambda below Lambda less than one +so the test for stability will be in the + + align:start position:0% +so the test for stability will be in the + + + align:start position:0% +so the test for stability will be in the +discrete case it won't be the real it + + align:start position:0% +discrete case it won't be the real it + + + align:start position:0% +discrete case it won't be the real it +won't be the real part of Lambda it'll + + align:start position:0% +won't be the real part of Lambda it'll + + + align:start position:0% +won't be the real part of Lambda it'll +be the size of Lambda less than one and + + align:start position:0% +be the size of Lambda less than one and + + + align:start position:0% +be the size of Lambda less than one and +growth would be the size of Lambda + + align:start position:0% +growth would be the size of Lambda + + + align:start position:0% +growth would be the size of Lambda +greater than one yeah so and and and + + align:start position:0% +greater than one yeah so and and and + + + align:start position:0% +greater than one yeah so and and and +again there'll be this borderline case + + align:start position:0% +again there'll be this borderline case + + + align:start position:0% +again there'll be this borderline case +when the igen value has magnitude + + align:start position:0% +when the igen value has magnitude + + + align:start position:0% +when the igen value has magnitude +exactly what okay so you're + + align:start position:0% +exactly what okay so you're + + + align:start position:0% +exactly what okay so you're +seeing uh here and and also here the + + align:start position:0% +seeing uh here and and also here the + + + align:start position:0% +seeing uh here and and also here the +idea that we may have to deal with + + align:start position:0% +idea that we may have to deal with + + + align:start position:0% +idea that we may have to deal with +complex numbers + + align:start position:0% +complex numbers + + + align:start position:0% +complex numbers +here we don't have to deal with the + + align:start position:0% +here we don't have to deal with the + + + align:start position:0% +here we don't have to deal with the +whole world of complex functions and and + + align:start position:0% +whole world of complex functions and and + + + align:start position:0% +whole world of complex functions and and +everything but but it's possible for + + align:start position:0% +everything but but it's possible for + + + align:start position:0% +everything but but it's possible for +complex numbers to come + + align:start position:0% +complex numbers to come + + + align:start position:0% +complex numbers to come +in well while I'm saying that why don't + + align:start position:0% +in well while I'm saying that why don't + + + align:start position:0% +in well while I'm saying that why don't +I say give an example where it would + + align:start position:0% +I say give an example where it would + + + align:start position:0% +I say give an example where it would +come in suppose I so this is so this is + + align:start position:0% +come in suppose I so this is so this is + + + align:start position:0% +come in suppose I so this is so this is +a like a + + align:start position:0% +a like a + + + align:start position:0% +a like a +this is going to be a real + + align:start position:0% +this is going to be a real + + + align:start position:0% +this is going to be a real +Matrix with complex I + + align:start position:0% +Matrix with complex I + + + align:start position:0% +Matrix with complex I +values complex + + align:start position:0% +values complex + + + align:start position:0% +values complex +lambdas okay this is it'll be an + + align:start position:0% +lambdas okay this is it'll be an + + + align:start position:0% +lambdas okay this is it'll be an +example + + align:start position:0% +example + + + align:start position:0% +example +and + + align:start position:0% + + + + align:start position:0% + +okay so I guess I'm looking for a + + align:start position:0% +okay so I guess I'm looking for a + + + align:start position:0% +okay so I guess I'm looking for a +matrix + + align:start position:0% +matrix + + + align:start position:0% +matrix +where Y and ay never come out in the + + align:start position:0% +where Y and ay never come out in the + + + align:start position:0% +where Y and ay never come out in the +same direction for real + + align:start position:0% +same direction for real + + + align:start position:0% +same direction for real +wise I know okay here's a good Matrix + + align:start position:0% +wise I know okay here's a good Matrix + + + align:start position:0% +wise I know okay here's a good Matrix +take the Matrix that rotates every + + align:start position:0% +take the Matrix that rotates every + + + align:start position:0% +take the Matrix that rotates every +vector by 90 + + align:start position:0% + + + + align:start position:0% + +degrees or or by Theta by Theta but + + align:start position:0% +degrees or or by Theta by Theta but + + + align:start position:0% +degrees or or by Theta by Theta but +let's let's say here here's a matrix + + align:start position:0% +let's let's say here here's a matrix + + + align:start position:0% +let's let's say here here's a matrix +that rotates every vector by 90 + + align:start position:0% + + + + align:start position:0% + +Dees I'm going to raise this board and + + align:start position:0% +Dees I'm going to raise this board and + + + align:start position:0% +Dees I'm going to raise this board and +hide it behind there in a minute I just + + align:start position:0% +hide it behind there in a minute I just + + + align:start position:0% +hide it behind there in a minute I just +wanted to just to open up this this + + align:start position:0% +wanted to just to open up this this + + + align:start position:0% +wanted to just to open up this this +thought that we do we will have to face + + align:start position:0% +thought that we do we will have to face + + + align:start position:0% +thought that we do we will have to face +complex numbers I'm I'm you probably + + align:start position:0% +complex numbers I'm I'm you probably + + + align:start position:0% +complex numbers I'm I'm you probably +have you know if you know how to + + align:start position:0% +have you know if you know how to + + + align:start position:0% +have you know if you know how to +multiply two complex numbers and add + + align:start position:0% +multiply two complex numbers and add + + + align:start position:0% +multiply two complex numbers and add +them + + align:start position:0% +them + + + align:start position:0% +them +uh you're okay this isn't going to turn + + align:start position:0% +uh you're okay this isn't going to turn + + + align:start position:0% +uh you're okay this isn't going to turn +into a big deal but let's just realize + + align:start position:0% +into a big deal but let's just realize + + + align:start position:0% +into a big deal but let's just realize +that suppose that Matrix if I put in a + + align:start position:0% +that suppose that Matrix if I put in a + + + align:start position:0% +that suppose that Matrix if I put in a +vector y + + align:start position:0% +vector y + + + align:start position:0% +vector y +and I multiply by that Matrix it'll turn + + align:start position:0% +and I multiply by that Matrix it'll turn + + + align:start position:0% +and I multiply by that Matrix it'll turn +it through 90 + + align:start position:0% +it through 90 + + + align:start position:0% +it through 90 +de so it so y couldn't be an igen Vector + + align:start position:0% +de so it so y couldn't be an igen Vector + + + align:start position:0% +de so it so y couldn't be an igen Vector +that's the point I'm trying to make no + + align:start position:0% +that's the point I'm trying to make no + + + align:start position:0% +that's the point I'm trying to make no +real Vector of a ro could be the igen + + align:start position:0% +real Vector of a ro could be the igen + + + align:start position:0% +real Vector of a ro could be the igen +vector of a rotation Matrix because + + align:start position:0% +vector of a rotation Matrix because + + + align:start position:0% +vector of a rotation Matrix because +every Vector gets + + align:start position:0% +every Vector gets + + + align:start position:0% +every Vector gets +turned so that's an example where you'd + + align:start position:0% +turned so that's an example where you'd + + + align:start position:0% +turned so that's an example where you'd +have to go + + align:start position:0% +have to go + + + align:start position:0% +have to go +to complex vectors and I think if I + + align:start position:0% +to complex vectors and I think if I + + + align:start position:0% +to complex vectors and I think if I +tried if I tried the vector one 1 I so + + align:start position:0% +tried if I tried the vector one 1 I so + + + align:start position:0% +tried if I tried the vector one 1 I so +I'm letting the sare root of minus1 into + + align:start position:0% +I'm letting the sare root of minus1 into + + + align:start position:0% +I'm letting the sare root of minus1 into +here then I think it would come out uh + + align:start position:0% +here then I think it would come out uh + + + align:start position:0% +here then I think it would come out uh +let see if I do that multiplication I + + align:start position:0% +let see if I do that multiplication I + + + align:start position:0% +let see if I do that multiplication I +get minus I and I get one and I think + + align:start position:0% +get minus I and I get one and I think + + + align:start position:0% +get minus I and I get one and I think +that this + + align:start position:0% +that this + + + align:start position:0% +that this +is what is it this is probably minus I + + align:start position:0% +is what is it this is probably minus I + + + align:start position:0% +is what is it this is probably minus I +times that so this is minus I times the + + align:start position:0% +times that so this is minus I times the + + + align:start position:0% +times that so this is minus I times the +input + + align:start position:0% + + + + align:start position:0% + +no big deal that that was like you can + + align:start position:0% +no big deal that that was like you can + + + align:start position:0% +no big deal that that was like you can +forget that it's + + align:start position:0% +forget that it's + + + align:start position:0% +forget that it's +just complex numbers can come in right + + align:start position:0% +just complex numbers can come in right + + + align:start position:0% +just complex numbers can come in right +okay okay now let me come back to the + + align:start position:0% +okay okay now let me come back to the + + + align:start position:0% +okay okay now let me come back to the +main point about igen vectors okay okay + + align:start position:0% +main point about igen vectors okay okay + + + align:start position:0% +main point about igen vectors okay okay +all right so they they things can be + + align:start position:0% +all right so they they things can be + + + align:start position:0% +all right so they they things can be +complex all right + + align:start position:0% +complex all right + + + align:start position:0% +complex all right +so the main point is how do we use them + + align:start position:0% +so the main point is how do we use them + + + align:start position:0% +so the main point is how do we use them +and how many are + + align:start position:0% + + + + align:start position:0% + +there + + align:start position:0% +there + + + align:start position:0% +there +well the here's the key that a typical + + align:start position:0% +well the here's the key that a typical + + + align:start position:0% +well the here's the key that a typical +good Matrix which includes every + + align:start position:0% +good Matrix which includes every + + + align:start position:0% +good Matrix which includes every +symmetric Matrix so it includes all of + + align:start position:0% +symmetric Matrix so it includes all of + + + align:start position:0% +symmetric Matrix so it includes all of +our examples and more if it's of size a + + align:start position:0% +our examples and more if it's of size a + + + align:start position:0% +our examples and more if it's of size a +thousand it will have a thousand + + align:start position:0% +thousand it will have a thousand + + + align:start position:0% +thousand it will have a thousand +different igen + + align:start position:0% +different igen + + + align:start position:0% +different igen +vectors and for our let me just say for + + align:start position:0% +vectors and for our let me just say for + + + align:start position:0% +vectors and for our let me just say for +our symmetric + + align:start position:0% +our symmetric + + + align:start position:0% +our symmetric +matrices those igen vectors will all be + + align:start position:0% +matrices those igen vectors will all be + + + align:start position:0% +matrices those igen vectors will all be +real they're they're great the igen + + align:start position:0% +real they're they're great the igen + + + align:start position:0% +real they're they're great the igen +vectors of symmetric matrices oh let me + + align:start position:0% +vectors of symmetric matrices oh let me + + + align:start position:0% +vectors of symmetric matrices oh let me +find them for one particular symmetric + + align:start position:0% +find them for one particular symmetric + + + align:start position:0% +find them for one particular symmetric +Matrix say this + + align:start position:0% + + + + align:start position:0% + +guy so that's a matrix 2 by two how many + + align:start position:0% +guy so that's a matrix 2 by two how many + + + align:start position:0% +guy so that's a matrix 2 by two how many +ion vectors am I now looking + + align:start position:0% +ion vectors am I now looking + + + align:start position:0% +ion vectors am I now looking +for + + align:start position:0% +for + + + align:start position:0% +for +two you could say how do I find + + align:start position:0% +two you could say how do I find + + + align:start position:0% +two you could say how do I find +them maybe with that 2 by two I can even + + align:start position:0% +them maybe with that 2 by two I can even + + + align:start position:0% +them maybe with that 2 by two I can even +just like uh wing it uh you you we can + + align:start position:0% +just like uh wing it uh you you we can + + + align:start position:0% +just like uh wing it uh you you we can +come up with a vector that that is an + + align:start position:0% +come up with a vector that that is an + + + align:start position:0% +come up with a vector that that is an +igen Vector that's that's not a that's + + align:start position:0% +igen Vector that's that's not a that's + + + align:start position:0% +igen Vector that's that's not a that's +actually that's what we're going to do + + align:start position:0% +actually that's what we're going to do + + + align:start position:0% +actually that's what we're going to do +here is we're going to guess the igen + + align:start position:0% +here is we're going to guess the igen + + + align:start position:0% +here is we're going to guess the igen +vectors and then we're going to show + + align:start position:0% +vectors and then we're going to show + + + align:start position:0% +vectors and then we're going to show +that they really are igen vectors and + + align:start position:0% +that they really are igen vectors and + + + align:start position:0% +that they really are igen vectors and +we'll know the igen values and it's + + align:start position:0% +we'll know the igen values and it's + + + align:start position:0% +we'll know the igen values and it's +fantastic so like let's start here with + + align:start position:0% +fantastic so like let's start here with + + + align:start position:0% +fantastic so like let's start here with +the 2 by two + + align:start position:0% +the 2 by two + + + align:start position:0% +the 2 by two +case anybody spot an igen Vector is one + + align:start position:0% +case anybody spot an igen Vector is one + + + align:start position:0% +case anybody spot an igen Vector is one +zero an igen Vector try one Zer what + + align:start position:0% +zero an igen Vector try one Zer what + + + align:start position:0% +zero an igen Vector try one Zer what +comes out of one + + align:start position:0% +comes out of one + + + align:start position:0% +comes out of one +zero well that picks the First Column + + align:start position:0% +zero well that picks the First Column + + + align:start position:0% +zero well that picks the First Column +right that's how I see multiplying by + + align:start position:0% +right that's how I see multiplying by + + + align:start position:0% +right that's how I see multiplying by +one zero that says take one of the First + + align:start position:0% +one zero that says take one of the First + + + align:start position:0% +one zero that says take one of the First +Column and is it an igen + + align:start position:0% +Column and is it an igen + + + align:start position:0% +Column and is it an igen +Vector yes no + + align:start position:0% +Vector yes no + + + align:start position:0% +Vector yes no +no this Vector is not in the same + + align:start position:0% +no this Vector is not in the same + + + align:start position:0% +no this Vector is not in the same +direction as that one no good okay now + + align:start position:0% +direction as that one no good okay now + + + align:start position:0% +direction as that one no good okay now +can you tell me one that + + align:start position:0% + + + + align:start position:0% + +is you're going to guess it one one try + + align:start position:0% +is you're going to guess it one one try + + + align:start position:0% +is you're going to guess it one one try +one + + align:start position:0% +one + + + align:start position:0% +one +one do the multiplication and what do + + align:start position:0% +one do the multiplication and what do + + + align:start position:0% +one do the multiplication and what do +you + + align:start position:0% + + + + align:start position:0% + +get right what do I get from if I input + + align:start position:0% +get right what do I get from if I input + + + align:start position:0% +get right what do I get from if I input +this Vector Y what do I get get + + align:start position:0% +this Vector Y what do I get get + + + align:start position:0% +this Vector Y what do I get get +out actually I get y + + align:start position:0% + + + + align:start position:0% + +itself right so so I get the point is it + + align:start position:0% +itself right so so I get the point is it + + + align:start position:0% +itself right so so I get the point is it +didn't change direction and it didn't + + align:start position:0% +didn't change direction and it didn't + + + align:start position:0% +didn't change direction and it didn't +even change length so what's the igen + + align:start position:0% +even change length so what's the igen + + + align:start position:0% +even change length so what's the igen +value for that so I've got one IG value + + align:start position:0% +value for that so I've got one IG value + + + align:start position:0% +value for that so I've got one IG value +now one igen vector one one and I've got + + align:start position:0% +now one igen vector one one and I've got + + + align:start position:0% +now one igen vector one one and I've got +the IG value uh so here are the vectors + + align:start position:0% +the IG value uh so here are the vectors + + + align:start position:0% +the IG value uh so here are the vectors +the Y's and here are the lambdas and + + align:start position:0% +the Y's and here are the lambdas and + + + align:start position:0% +the Y's and here are the lambdas and +I've got one of them and it's one + + align:start position:0% +I've got one of them and it's one + + + align:start position:0% +I've got one of them and it's one +right would you like to guess the other + + align:start position:0% +right would you like to guess the other + + + align:start position:0% +right would you like to guess the other +one I'm only looking for two because + + align:start position:0% +one I'm only looking for two because + + + align:start position:0% +one I'm only looking for two because +it's a 2X two Matrix so let me Erase + + align:start position:0% +it's a 2X two Matrix so let me Erase + + + align:start position:0% +it's a 2X two Matrix so let me Erase +here hope that you'll come up with + + align:start position:0% +here hope that you'll come up with + + + align:start position:0% +here hope that you'll come up with +another + + align:start position:0% +another + + + align:start position:0% +another +one one negative one is certainly worth + + align:start position:0% +one one negative one is certainly worth + + + align:start position:0% +one one negative one is certainly worth +a + + align:start position:0% +a + + + align:start position:0% +a +try let's test it is if it's an igen + + align:start position:0% +try let's test it is if it's an igen + + + align:start position:0% +try let's test it is if it's an igen +Vector then it should come out in the + + align:start position:0% +Vector then it should come out in the + + + align:start position:0% +Vector then it should come out in the +same direction what do I get when I do + + align:start position:0% +same direction what do I get when I do + + + align:start position:0% +same direction what do I get when I do +that if I do that multiplic + + align:start position:0% +that if I do that multiplic + + + align:start position:0% +that if I do that multiplic +three and I get three and minus three so + + align:start position:0% +three and I get three and minus three so + + + align:start position:0% +three and I get three and minus three so +have we got an igen Vector yep and and + + align:start position:0% +have we got an igen Vector yep and and + + + align:start position:0% +have we got an igen Vector yep and and +what's so if this was Y what is this + + align:start position:0% +what's so if this was Y what is this + + + align:start position:0% +what's so if this was Y what is this +Vector 3 y so there's the other igen + + align:start position:0% +Vector 3 y so there's the other igen + + + align:start position:0% +Vector 3 y so there's the other igen +Vector is one minus one and the other IG + + align:start position:0% +Vector is one minus one and the other IG + + + align:start position:0% +Vector is one minus one and the other IG +value is + + align:start position:0% + + + + align:start position:0% + +three okay so we did it by spotting it + + align:start position:0% +three okay so we did it by spotting it + + + align:start position:0% +three okay so we did it by spotting it +here that's you know mad lab can't do it + + align:start position:0% +here that's you know mad lab can't do it + + + align:start position:0% +here that's you know mad lab can't do it +that way it's got to figure it out but + + align:start position:0% +that way it's got to figure it out but + + + align:start position:0% +that way it's got to figure it out but +we're ahead of mad lab this time okay + + align:start position:0% +we're ahead of mad lab this time okay + + + align:start position:0% +we're ahead of mad lab this time okay +all right so what do I notice what do I + + align:start position:0% +all right so what do I notice what do I + + + align:start position:0% +all right so what do I notice what do I +notice what do I notice about this + + align:start position:0% +notice what do I notice about this + + + align:start position:0% +notice what do I notice about this +Matrix it was + + align:start position:0% +Matrix it was + + + align:start position:0% +Matrix it was +symmetric and what do I notice about the + + align:start position:0% +symmetric and what do I notice about the + + + align:start position:0% +symmetric and what do I notice about the +igen + + align:start position:0% +igen + + + align:start position:0% +igen +vectors if I if I show you those two + + align:start position:0% +vectors if I if I show you those two + + + align:start position:0% +vectors if I if I show you those two +vectors 1 one and 1 minus + + align:start position:0% +vectors 1 one and 1 minus + + + align:start position:0% +vectors 1 one and 1 minus +one what do you see there they're + + align:start position:0% +one what do you see there they're + + + align:start position:0% +one what do you see there they're +orthogonal 1 + + align:start position:0% +orthogonal 1 + + + align:start position:0% +orthogonal 1 +one is orthogonal to one minus + + align:start position:0% +one is orthogonal to one minus + + + align:start position:0% +one is orthogonal to one minus +perpendicular is the same as orthogonal + + align:start position:0% +perpendicular is the same as orthogonal + + + align:start position:0% +perpendicular is the same as orthogonal +the these are + + align:start position:0% +the these are + + + align:start position:0% +the these are +orthogonal perpendicular and and and + + align:start position:0% +orthogonal perpendicular and and and + + + align:start position:0% +orthogonal perpendicular and and and +what let's + + align:start position:0% + + + + align:start position:0% + +see I can draw them of course and see + + align:start position:0% +see I can draw them of course and see + + + align:start position:0% +see I can draw them of course and see +that one one will go here's if this is + + align:start position:0% +that one one will go here's if this is + + + align:start position:0% +that one one will go here's if this is +one it'll go here and one so that's 1 + + align:start position:0% +one it'll go here and one so that's 1 + + + align:start position:0% +one it'll go here and one so that's 1 +one and 1 minus one will go there will + + align:start position:0% +one and 1 minus one will go there will + + + align:start position:0% +one and 1 minus one will go there will +go down this will be the other one one + + align:start position:0% +go down this will be the other one one + + + align:start position:0% +go down this will be the other one one +minus one so there's y1 there's Y 2 and + + align:start position:0% +minus one so there's y1 there's Y 2 and + + + align:start position:0% +minus one so there's y1 there's Y 2 and +they are + + align:start position:0% +they are + + + align:start position:0% +they are +perpendicular but of course I don't draw + + align:start position:0% +perpendicular but of course I don't draw + + + align:start position:0% +perpendicular but of course I don't draw +pictures all the time what how do I + + align:start position:0% +pictures all the time what how do I + + + align:start position:0% +pictures all the time what how do I +test what's the test for two vectors + + align:start position:0% +test what's the test for two vectors + + + align:start position:0% +test what's the test for two vectors +being + + align:start position:0% +being + + + align:start position:0% +being +orthogonal the dot product the dot + + align:start position:0% +orthogonal the dot product the dot + + + align:start position:0% +orthogonal the dot product the dot +product the inner product y transpose y1 + + align:start position:0% +product the inner product y transpose y1 + + + align:start position:0% +product the inner product y transpose y1 +transpose + + align:start position:0% +transpose + + + align:start position:0% +transpose +Y2 or do you prefer to write it as y1 + + align:start position:0% +Y2 or do you prefer to write it as y1 + + + align:start position:0% +Y2 or do you prefer to write it as y1 +with a DOT Y + + align:start position:0% +with a DOT Y + + + align:start position:0% +with a DOT Y +2 this one this is maybe better because + + align:start position:0% +2 this one this is maybe better because + + + align:start position:0% +2 this one this is maybe better because +it's Matrix notation and the point is + + align:start position:0% +it's Matrix notation and the point is + + + align:start position:0% +it's Matrix notation and the point is +orthogonal the dotproduct + + align:start position:0% +orthogonal the dotproduct + + + align:start position:0% +orthogonal the dotproduct +is zero right zero okay so that's good + + align:start position:0% +is zero right zero okay so that's good + + + align:start position:0% +is zero right zero okay so that's good +very good in + + align:start position:0% +very good in + + + align:start position:0% +very good in +fact symmet so here's a + + align:start position:0% +fact symmet so here's a + + + align:start position:0% +fact symmet so here's a +very important fact symmetric matrices + + align:start position:0% +very important fact symmetric matrices + + + align:start position:0% +very important fact symmetric matrices +have orthogonal IG + + align:start position:0% +have orthogonal IG + + + align:start position:0% +have orthogonal IG +vectors Sim so igen vectors what I'm + + align:start position:0% +vectors Sim so igen vectors what I'm + + + align:start position:0% +vectors Sim so igen vectors what I'm +trying to say is igen vectors and igen + + align:start position:0% +trying to say is igen vectors and igen + + + align:start position:0% +trying to say is igen vectors and igen +values are like a new way to look at a + + align:start position:0% +values are like a new way to look at a + + + align:start position:0% +values are like a new way to look at a +matrix a new way to see into + + align:start position:0% +matrix a new way to see into + + + align:start position:0% +matrix a new way to see into +it and when the Matrix is symmetric what + + align:start position:0% +it and when the Matrix is symmetric what + + + align:start position:0% +it and when the Matrix is symmetric what +we see is perpendicular igen vectors and + + align:start position:0% +we see is perpendicular igen vectors and + + + align:start position:0% +we see is perpendicular igen vectors and +what comment do you have about the + + align:start position:0% +what comment do you have about the + + + align:start position:0% +what comment do you have about the +values of this symmetric + + align:start position:0% +values of this symmetric + + + align:start position:0% +values of this symmetric +Matrix having remembering what + + align:start position:0% +Matrix having remembering what + + + align:start position:0% +Matrix having remembering what +was on the board for this anti-symmetric + + align:start position:0% +was on the board for this anti-symmetric + + + align:start position:0% +was on the board for this anti-symmetric +Matrix this anti what was the point + + align:start position:0% +Matrix this anti what was the point + + + align:start position:0% +Matrix this anti what was the point +about that anti-symmetric + + align:start position:0% +about that anti-symmetric + + + align:start position:0% +about that anti-symmetric +Matrix its igen values + + align:start position:0% +Matrix its igen values + + + align:start position:0% +Matrix its igen values +were imaginary actually an i there okay + + align:start position:0% +were imaginary actually an i there okay + + + align:start position:0% +were imaginary actually an i there okay +here's the opposite what's the what's + + align:start position:0% +here's the opposite what's the what's + + + align:start position:0% +here's the opposite what's the what's +the property of the igen values for for + + align:start position:0% +the property of the igen values for for + + + align:start position:0% +the property of the igen values for for +a symmetric Matrix that you would just + + align:start position:0% +a symmetric Matrix that you would just + + + align:start position:0% +a symmetric Matrix that you would just +guess they're real they're real + + align:start position:0% +guess they're real they're real + + + align:start position:0% +guess they're real they're real +symmetric matrices are great because + + align:start position:0% +symmetric matrices are great because + + + align:start position:0% +symmetric matrices are great because +they have real igen + + align:start position:0% +they have real igen + + + align:start position:0% +they have real igen +values and they have perpendicular igen + + align:start position:0% + + + + align:start position:0% + +vectors + + align:start position:0% + + + + align:start position:0% + +and uh and actually probably if a matrix + + align:start position:0% +and uh and actually probably if a matrix + + + align:start position:0% +and uh and actually probably if a matrix +has real igen values and perpendicular + + align:start position:0% +has real igen values and perpendicular + + + align:start position:0% +has real igen values and perpendicular +igen vectors it's going to be symmetric + + align:start position:0% +igen vectors it's going to be symmetric + + + align:start position:0% +igen vectors it's going to be symmetric +so s symmetry is a great property and it + + align:start position:0% +so s symmetry is a great property and it + + + align:start position:0% +so s symmetry is a great property and it +shows up in a great way in this real I + + align:start position:0% +shows up in a great way in this real I + + + align:start position:0% +shows up in a great way in this real I +Val real lambdas and orthogonal y's + + align:start position:0% +Val real lambdas and orthogonal y's + + + align:start position:0% +Val real lambdas and orthogonal y's +shows up perfectly in the igen + + align:start position:0% +shows up perfectly in the igen + + + align:start position:0% +shows up perfectly in the igen +picture and let's see I was going to say + + align:start position:0% +picture and let's see I was going to say + + + align:start position:0% +picture and let's see I was going to say +oh yeah another here here's a handy + + align:start position:0% +oh yeah another here here's a handy + + + align:start position:0% +oh yeah another here here's a handy +little check on the igen values to see + + align:start position:0% +little check on the igen values to see + + + align:start position:0% +little check on the igen values to see +if we got it right of course we did I + + align:start position:0% +if we got it right of course we did I + + + align:start position:0% +if we got it right of course we did I +mean that's one and three we can get but + + align:start position:0% +mean that's one and three we can get but + + + align:start position:0% +mean that's one and three we can get but +let me let me just show you two two + + align:start position:0% +let me let me just show you two two + + + align:start position:0% +let me let me just show you two two +useful checks if you haven't seen igen + + align:start position:0% +useful checks if you haven't seen igen + + + align:start position:0% +useful checks if you haven't seen igen +values before if I add the igen + + align:start position:0% +values before if I add the igen + + + align:start position:0% +values before if I add the igen +values what do I get + + align:start position:0% +values what do I get + + + align:start position:0% +values what do I get +four and I compare that with adding down + + align:start position:0% +four and I compare that with adding down + + + align:start position:0% +four and I compare that with adding down +the diagonal of the Matrix two and two + + align:start position:0% +the diagonal of the Matrix two and two + + + align:start position:0% +the diagonal of the Matrix two and two +four and that check always works the sum + + align:start position:0% +four and that check always works the sum + + + align:start position:0% +four and that check always works the sum +of the igen values matches the sum down + + align:start position:0% +of the igen values matches the sum down + + + align:start position:0% +of the igen values matches the sum down +the diagonal so that that's it's like if + + align:start position:0% +the diagonal so that that's it's like if + + + align:start position:0% +the diagonal so that that's it's like if +you only had one if you got all the IG + + align:start position:0% +you only had one if you got all the IG + + + align:start position:0% +you only had one if you got all the IG +values but one that would tell you the + + align:start position:0% +values but one that would tell you the + + + align:start position:0% +values but one that would tell you the +last one because uh the some of the igen + + align:start position:0% +last one because uh the some of the igen + + + align:start position:0% +last one because uh the some of the igen +values matches the sum down the diagonal + + align:start position:0% +values matches the sum down the diagonal + + + align:start position:0% +values matches the sum down the diagonal +that's that's sort of you have no clue + + align:start position:0% +that's that's sort of you have no clue + + + align:start position:0% +that's that's sort of you have no clue +where that comes from but it it's true + + align:start position:0% +where that comes from but it it's true + + + align:start position:0% +where that comes from but it it's true +and + + align:start position:0% +and + + + align:start position:0% +and +another another useful fact if I + + align:start position:0% +another another useful fact if I + + + align:start position:0% +another another useful fact if I +multiply the I values what do I get + + align:start position:0% +multiply the I values what do I get + + + align:start position:0% +multiply the I values what do I get +three and now where do you see a three + + align:start position:0% +three and now where do you see a three + + + align:start position:0% +three and now where do you see a three +over here + + align:start position:0% +over here + + + align:start position:0% +over here +the + + align:start position:0% +the + + + align:start position:0% +the +determinant 4 minus one 3 so let me can + + align:start position:0% +determinant 4 minus one 3 so let me can + + + align:start position:0% +determinant 4 minus one 3 so let me can +I just write those two facts with no + + align:start position:0% +I just write those two facts with no + + + align:start position:0% +I just write those two facts with no +with no idea of proof the sum of the + + align:start position:0% +with no idea of proof the sum of the + + + align:start position:0% +with no idea of proof the sum of the +lambdas can I just I could write + + align:start position:0% +lambdas can I just I could write + + + align:start position:0% +lambdas can I just I could write +suum sum of this is for any Matrix the + + align:start position:0% +suum sum of this is for any Matrix the + + + align:start position:0% +suum sum of this is for any Matrix the +sum of the lambdas is equal to this the + + align:start position:0% +sum of the lambdas is equal to this the + + + align:start position:0% +sum of the lambdas is equal to this the +the it's called the trace of the + + align:start position:0% +the it's called the trace of the + + + align:start position:0% +the it's called the trace of the +Matrix the trace of the Matrix is the + + align:start position:0% +Matrix the trace of the Matrix is the + + + align:start position:0% +Matrix the trace of the Matrix is the +sum down the + + align:start position:0% +sum down the + + + align:start position:0% +sum down the +diagonal and the product of the + + align:start position:0% +diagonal and the product of the + + + align:start position:0% +diagonal and the product of the +lambdas L Lambda 1 * Lambda 2 is the + + align:start position:0% +lambdas L Lambda 1 * Lambda 2 is the + + + align:start position:0% +lambdas L Lambda 1 * Lambda 2 is the +determinant of the Matrix or if I had 10 + + align:start position:0% +determinant of the Matrix or if I had 10 + + + align:start position:0% +determinant of the Matrix or if I had 10 +IG values I would multiply all 10 and + + align:start position:0% +IG values I would multiply all 10 and + + + align:start position:0% +IG values I would multiply all 10 and +I'd get the determinant + + align:start position:0% +I'd get the determinant + + + align:start position:0% +I'd get the determinant +okay okay so that's + + align:start position:0% +okay okay so that's + + + align:start position:0% +okay okay so that's +some facts about I values there's more + + align:start position:0% +some facts about I values there's more + + + align:start position:0% +some facts about I values there's more +of course in section + + align:start position:0% +of course in section + + + align:start position:0% +of course in section +1.5 uh about how you would find I values + + align:start position:0% +1.5 uh about how you would find I values + + + align:start position:0% +1.5 uh about how you would find I values +and how you would use + + align:start position:0% +and how you would use + + + align:start position:0% +and how you would use +them yeah yeah all right so we've got + + align:start position:0% +them yeah yeah all right so we've got + + + align:start position:0% +them yeah yeah all right so we've got +that's of course the key point is how + + align:start position:0% +that's of course the key point is how + + + align:start position:0% +that's of course the key point is how +would we use them oh let me let me uh + + align:start position:0% +would we use them oh let me let me uh + + + align:start position:0% +would we use them oh let me let me uh +say something more about that how to use + + align:start position:0% +say something more about that how to use + + + align:start position:0% +say something more about that how to use +I okay suppose I have this system of a + + align:start position:0% +I okay suppose I have this system of a + + + align:start position:0% +I okay suppose I have this system of a +thousand differential + + align:start position:0% + + + + align:start position:0% + +equations okay linear constant + + align:start position:0% +equations okay linear constant + + + align:start position:0% +equations okay linear constant +coefficients starts from some + + align:start position:0% +coefficients starts from some + + + align:start position:0% +coefficients starts from some +U of + + align:start position:0% +U of + + + align:start position:0% +U of +zero okay all + + align:start position:0% +zero okay all + + + align:start position:0% +zero okay all +right how can how do igen values and IG + + align:start position:0% +right how can how do igen values and IG + + + align:start position:0% +right how can how do igen values and IG +vectors help well first I have to find + + align:start position:0% +vectors help well first I have to find + + + align:start position:0% +vectors help well first I have to find +them that's the job so suppose I find a + + align:start position:0% +them that's the job so suppose I find a + + + align:start position:0% +them that's the job so suppose I find a +th igen values and I vectors A + + align:start position:0% +th igen values and I vectors A + + + align:start position:0% +th igen values and I vectors A +times I Vector number I is I value + + align:start position:0% +times I Vector number I is I value + + + align:start position:0% +times I Vector number I is I value +number I times I Vector number I so + + align:start position:0% +number I times I Vector number I so + + + align:start position:0% +number I times I Vector number I so +these y1 to Y a000 so y1 to Y a000 are + + align:start position:0% +these y1 to Y a000 so y1 to Y a000 are + + + align:start position:0% +these y1 to Y a000 so y1 to Y a000 are +the igen + + align:start position:0% +the igen + + + align:start position:0% +the igen +vectors and each one has its own igen + + align:start position:0% +vectors and each one has its own igen + + + align:start position:0% +vectors and each one has its own igen +value Lambda 1 to Lambda + + align:start position:0% +value Lambda 1 to Lambda + + + align:start position:0% +value Lambda 1 to Lambda +th000 and + + align:start position:0% +th000 and + + + align:start position:0% +th000 and +now if I did that work sort of like in + + align:start position:0% +now if I did that work sort of like in + + + align:start position:0% +now if I did that work sort of like in +advance now I come to the differential + + align:start position:0% +advance now I come to the differential + + + align:start position:0% +advance now I come to the differential +equation how could I use + + align:start position:0% +equation how could I use + + + align:start position:0% +equation how could I use +this it's it's a the probably this is + + align:start position:0% +this it's it's a the probably this is + + + align:start position:0% +this it's it's a the probably this is +now going to be the most the the + + align:start position:0% +now going to be the most the the + + + align:start position:0% +now going to be the most the the +constant three step it's it's three + + align:start position:0% +constant three step it's it's three + + + align:start position:0% +constant three step it's it's three +steps to use it three steps to use these + + align:start position:0% +steps to use it three steps to use these + + + align:start position:0% +steps to use it three steps to use these +to get the + + align:start position:0% +to get the + + + align:start position:0% +to get the +answer okay ready for step one step one + + align:start position:0% +answer okay ready for step one step one + + + align:start position:0% +answer okay ready for step one step one +is Step One is break you not into igen + + align:start position:0% +is Step One is break you not into igen + + + align:start position:0% +is Step One is break you not into igen +vectors split separate write Express U + + align:start position:0% +vectors split separate write Express U + + + align:start position:0% +vectors split separate write Express U +of zero as a combination of igen vectors + + align:start position:0% + + + + align:start position:0% + +okay now step + + align:start position:0% +okay now step + + + align:start position:0% +okay now step +two what happens to each igen Vector so + + align:start position:0% +two what happens to each igen Vector so + + + align:start position:0% +two what happens to each igen Vector so +this is where the differential equation + + align:start position:0% +this is where the differential equation + + + align:start position:0% +this is where the differential equation +starts from this is the the initial + + align:start position:0% +starts from this is the the initial + + + align:start position:0% +starts from this is the the initial +condition a th components of U at the + + align:start position:0% +condition a th components of U at the + + + align:start position:0% +condition a th components of U at the +start and it's separated into a + + align:start position:0% +start and it's separated into a + + + align:start position:0% +start and it's separated into a +thousand igen Vector pieces now step two + + align:start position:0% +thousand igen Vector pieces now step two + + + align:start position:0% +thousand igen Vector pieces now step two +is watch each h p separately so step two + + align:start position:0% +is watch each h p separately so step two + + + align:start position:0% +is watch each h p separately so step two +will be + + align:start position:0% + + + + align:start position:0% + +multiply say + + align:start position:0% + + + + align:start position:0% + +C1 by e to the Lambda 1 T by its its + + align:start position:0% +C1 by e to the Lambda 1 T by its its + + + align:start position:0% +C1 by e to the Lambda 1 T by its its +growth this is following igen Vector + + align:start position:0% +growth this is following igen Vector + + + align:start position:0% +growth this is following igen Vector +number one and in general I would + + align:start position:0% +number one and in general I would + + + align:start position:0% +number one and in general I would +multiply every one of the C's by e to + + align:start position:0% +multiply every one of the C's by e to + + + align:start position:0% +multiply every one of the C's by e to +the those guys so what would I have now + + align:start position:0% +the those guys so what would I have now + + + align:start position:0% +the those guys so what would I have now +this is where this is this is one piece + + align:start position:0% +this is where this is this is one piece + + + align:start position:0% +this is where this is this is one piece +of the start and that gives me one piece + + align:start position:0% +of the start and that gives me one piece + + + align:start position:0% +of the start and that gives me one piece +of the of the finish so the FI the + + align:start position:0% +of the of the finish so the FI the + + + align:start position:0% +of the of the finish so the FI the +Finish is the + + align:start position:0% +Finish is the + + + align:start position:0% +Finish is the +answer is to add + + align:start position:0% +answer is to add + + + align:start position:0% +answer is to add +up the thousand + + align:start position:0% +up the thousand + + + align:start position:0% +up the thousand +pieces and if you're with me you see + + align:start position:0% +pieces and if you're with me you see + + + align:start position:0% +pieces and if you're with me you see +what those thousand pieces + + align:start position:0% +what those thousand pieces + + + align:start position:0% +what those thousand pieces +are here's a piece some multiple of the + + align:start position:0% +are here's a piece some multiple of the + + + align:start position:0% +are here's a piece some multiple of the +first igen Vector now if we only were + + align:start position:0% +first igen Vector now if we only were + + + align:start position:0% +first igen Vector now if we only were +working with that piece we follow it in + + align:start position:0% +working with that piece we follow it in + + + align:start position:0% +working with that piece we follow it in +time by multiplying it by e to the + + align:start position:0% +time by multiplying it by e to the + + + align:start position:0% +time by multiplying it by e to the +Lambda 1 T and what do we have at a + + align:start position:0% +Lambda 1 T and what do we have at a + + + align:start position:0% +Lambda 1 T and what do we have at a +later + + align:start position:0% +later + + + align:start position:0% +later +time C1 e to the Lambda 1 T y1 that's + + align:start position:0% +time C1 e to the Lambda 1 T y1 that's + + + align:start position:0% +time C1 e to the Lambda 1 T y1 that's +what this piece has this piece has grown + + align:start position:0% +what this piece has this piece has grown + + + align:start position:0% +what this piece has this piece has grown +into + + align:start position:0% +into + + + align:start position:0% +into +that and other pieces have grown into + + align:start position:0% +that and other pieces have grown into + + + align:start position:0% +that and other pieces have grown into +other things and what about the last + + align:start position:0% +other things and what about the last + + + align:start position:0% +other things and what about the last +piece so what does + + align:start position:0% +piece so what does + + + align:start position:0% +piece so what does +this what is it that I have to add up + + align:start position:0% +this what is it that I have to add up + + + align:start position:0% +this what is it that I have to add up +tell me what to write here c1000 + + align:start position:0% +tell me what to write here c1000 + + + align:start position:0% +tell me what to write here c1000 +whatever that Co however much of igen + + align:start position:0% +whatever that Co however much of igen + + + align:start position:0% +whatever that Co however much of igen +vector 1,000 was in + + align:start position:0% +vector 1,000 was in + + + align:start position:0% +vector 1,000 was in +there and then + + align:start position:0% +there and then + + + align:start position:0% +there and then +finally never written left-handed + + align:start position:0% + + + + align:start position:0% + +before e to the e to the + + align:start position:0% +before e to the e to the + + + align:start position:0% +before e to the e to the +who Lambda number 1,000 not 1,000 itself + + align:start position:0% +who Lambda number 1,000 not 1,000 itself + + + align:start position:0% +who Lambda number 1,000 not 1,000 itself +but the one its igen value + + align:start position:0% + + + + align:start position:0% + +1,t this is just splitting this is + + align:start position:0% +1,t this is just splitting this is + + + align:start position:0% +1,t this is just splitting this is +constantly constantly uh the method the + + align:start position:0% +constantly constantly uh the method the + + + align:start position:0% +constantly constantly uh the method the +way to use igen values and igen vectors + + align:start position:0% +way to use igen values and igen vectors + + + align:start position:0% +way to use igen values and igen vectors +split the split the problem into the + + align:start position:0% +split the split the problem into the + + + align:start position:0% +split the split the problem into the +pieces that go that that are I vectors + + align:start position:0% +pieces that go that that are I vectors + + + align:start position:0% +pieces that go that that are I vectors +watch each piece add up the add up the + + align:start position:0% +watch each piece add up the add up the + + + align:start position:0% +watch each piece add up the add up the +pieces yeah that that's the that's why + + align:start position:0% +pieces yeah that that's the that's why + + + align:start position:0% +pieces yeah that that's the that's why +ion vectors are so important + + align:start position:0% + + + + align:start position:0% + +yeah yes + + align:start position:0% +yeah yes + + + align:start position:0% +yeah yes +right well now very good + + align:start position:0% +right well now very good + + + align:start position:0% +right well now very good +question + + align:start position:0% +question + + + align:start position:0% +question +um let's see well the first thing we + + align:start position:0% +um let's see well the first thing we + + + align:start position:0% +um let's see well the first thing we +have to know is that we do find a + + align:start position:0% +have to know is that we do find a + + + align:start position:0% +have to know is that we do find a +thousand I + + align:start position:0% +thousand I + + + align:start position:0% +thousand I +vectors and So my answer is going to be + + align:start position:0% +vectors and So my answer is going to be + + + align:start position:0% +vectors and So my answer is going to be +for symmetric matrices everything always + + align:start position:0% +for symmetric matrices everything always + + + align:start position:0% +for symmetric matrices everything always +works for symmetric matrices if they + + align:start position:0% +works for symmetric matrices if they + + + align:start position:0% +works for symmetric matrices if they +size is a th000 they have a th000 i + + align:start position:0% +size is a th000 they have a th000 i + + + align:start position:0% +size is a th000 they have a th000 i +vector + + align:start position:0% +vector + + + align:start position:0% +vector +and next time we'll have a shot at some + + align:start position:0% +and next time we'll have a shot at some + + + align:start position:0% +and next time we'll have a shot at some +of these some what some of them are for + + align:start position:0% +of these some what some of them are for + + + align:start position:0% +of these some what some of them are for +these special + + align:start position:0% +these special + + + align:start position:0% +these special +matrices so this method always works if + + align:start position:0% +matrices so this method always works if + + + align:start position:0% +matrices so this method always works if +I've got a full family of independent + + align:start position:0% +I've got a full family of independent + + + align:start position:0% +I've got a full family of independent +igen vectors if it's of size a thousand + + align:start position:0% +igen vectors if it's of size a thousand + + + align:start position:0% +igen vectors if it's of size a thousand +I need you're right exactly right to see + + align:start position:0% +I need you're right exactly right to see + + + align:start position:0% +I need you're right exactly right to see +that this was the this was the the the + + align:start position:0% +that this was the this was the the the + + + align:start position:0% +that this was the this was the the the +questionable step if I haven't got a + + align:start position:0% +questionable step if I haven't got a + + + align:start position:0% +questionable step if I haven't got a +thousand I vectors I I'm not going to be + + align:start position:0% +thousand I vectors I I'm not going to be + + + align:start position:0% +thousand I vectors I I'm not going to be +able to take take that step and it + + align:start position:0% +able to take take that step and it + + + align:start position:0% +able to take take that step and it +happens I am sad to report that some + + align:start position:0% +happens I am sad to report that some + + + align:start position:0% +happens I am sad to report that some +matricies haven't got enough ion vectors + + align:start position:0% +matricies haven't got enough ion vectors + + + align:start position:0% +matricies haven't got enough ion vectors +some + + align:start position:0% +some + + + align:start position:0% +some +matrices they they get collapse you know + + align:start position:0% +matrices they they get collapse you know + + + align:start position:0% +matrices they they get collapse you know +this often always happens in in math + + align:start position:0% +this often always happens in in math + + + align:start position:0% +this often always happens in in math +somehow two igen vectors collapse into + + align:start position:0% +somehow two igen vectors collapse into + + + align:start position:0% +somehow two igen vectors collapse into +one and the Matrix is + + align:start position:0% +one and the Matrix is + + + align:start position:0% +one and the Matrix is +defective like it's a loser okay so now + + align:start position:0% +defective like it's a loser okay so now + + + align:start position:0% +defective like it's a loser okay so now +you have to of course this the equation + + align:start position:0% +you have to of course this the equation + + + align:start position:0% +you have to of course this the equation +still has a + + align:start position:0% +still has a + + + align:start position:0% +still has a +solution so there has to be something + + align:start position:0% +solution so there has to be something + + + align:start position:0% +solution so there has to be something +there but the IG ve the pure igen Vector + + align:start position:0% +there but the IG ve the pure igen Vector + + + align:start position:0% +there but the IG ve the pure igen Vector +method is not going to make it on those + + align:start position:0% +method is not going to make it on those + + + align:start position:0% +method is not going to make it on those +special matrices I could write down one + + align:start position:0% +special matrices I could write down one + + + align:start position:0% +special matrices I could write down one +but why should we give space to a loser + + align:start position:0% +but why should we give space to a loser + + + align:start position:0% +but why should we give space to a loser +okay so but what what what happens in + + align:start position:0% +okay so but what what what happens in + + + align:start position:0% +okay so but what what what happens in +that + + align:start position:0% +that + + + align:start position:0% +that +case you might remember from + + align:start position:0% +case you might remember from + + + align:start position:0% +case you might remember from +differential equations when two of these + + align:start position:0% +differential equations when two of these + + + align:start position:0% +differential equations when two of these +roots + + align:start position:0% +roots + + + align:start position:0% +roots +these are like Roots these lambdas are + + align:start position:0% +these are like Roots these lambdas are + + + align:start position:0% +these are like Roots these lambdas are +like roots that you found in solving a + + align:start position:0% +like roots that you found in solving a + + + align:start position:0% +like roots that you found in solving a +differential equation when two of them + + align:start position:0% +differential equation when two of them + + + align:start position:0% +differential equation when two of them +come together that's when the danger is + + align:start position:0% +come together that's when the danger is + + + align:start position:0% +come together that's when the danger is +when when I have a double ion value then + + align:start position:0% +when when I have a double ion value then + + + align:start position:0% +when when I have a double ion value then +there's a high risk that I've only got + + align:start position:0% +there's a high risk that I've only got + + + align:start position:0% +there's a high risk that I've only got +one IG vector and I I'll just put in + + align:start position:0% +one IG vector and I I'll just put in + + + align:start position:0% +one IG vector and I I'll just put in +this little thing what what the other so + + align:start position:0% +this little thing what what the other so + + + align:start position:0% +this little thing what what the other so +the e to the Lambda 1 T is fine but if + + align:start position:0% +the e to the Lambda 1 T is fine but if + + + align:start position:0% +the e to the Lambda 1 T is fine but if +that y1 is like + + align:start position:0% +that y1 is like + + + align:start position:0% +that y1 is like +if the Lambda one's in there twice I + + align:start position:0% +if the Lambda one's in there twice I + + + align:start position:0% +if the Lambda one's in there twice I +need something new and the new one you + + align:start position:0% +need something new and the new one you + + + align:start position:0% +need something new and the new one you +the new thing turns out to be t e the + + align:start position:0% +the new thing turns out to be t e the + + + align:start position:0% +the new thing turns out to be t e the +Lambda + + align:start position:0% +Lambda + + + align:start position:0% +Lambda +T does I don't know if anybody remembers + + align:start position:0% +T does I don't know if anybody remembers + + + align:start position:0% +T does I don't know if anybody remembers +this was probably hammered back in + + align:start position:0% +this was probably hammered back in + + + align:start position:0% +this was probably hammered back in +differential equations that if you had + + align:start position:0% +differential equations that if you had + + + align:start position:0% +differential equations that if you had +repeated something or other then this + + align:start position:0% +repeated something or other then this + + + align:start position:0% +repeated something or other then this +you you didn't get pure e to the Lambda + + align:start position:0% +you you didn't get pure e to the Lambda + + + align:start position:0% +you you didn't get pure e to the Lambda +T's you got also a t to the Lambda T + + align:start position:0% +T's you got also a t to the Lambda T + + + align:start position:0% +T's you got also a t to the Lambda T +anyway that's the answer that's that if + + align:start position:0% +anyway that's the answer that's that if + + + align:start position:0% +anyway that's the answer that's that if +we're short I vectors and it can happen + + align:start position:0% +we're short I vectors and it can happen + + + align:start position:0% +we're short I vectors and it can happen +but it won't for our good matrices okay + + align:start position:0% +but it won't for our good matrices okay + + + align:start position:0% +but it won't for our good matrices okay +so Monday I've got lots to + + align:start position:0% +so Monday I've got lots to + + + align:start position:0% +so Monday I've got lots to +do special Ian values and vectors and + + align:start position:0% +do special Ian values and vectors and + + + align:start position:0% +do special Ian values and vectors and +then positive definite \ No newline at end of file diff --git a/hBG7nMXTOcw.txt b/hBG7nMXTOcw.txt new file mode 100644 index 0000000000000000000000000000000000000000..529039eec5febd11d2052ef3a38632be49efe51f --- /dev/null +++ b/hBG7nMXTOcw.txt @@ -0,0 +1,11427 @@ +align:start position:0% + +just the last year the sharp projection + + align:start position:0% +just the last year the sharp projection + + + align:start position:0% +just the last year the sharp projection +theorem in R2 was was proven and um the + + align:start position:0% +theorem in R2 was was proven and um the + + + align:start position:0% +theorem in R2 was was proven and um the +proof is is fairly big. It's fairly + + align:start position:0% +proof is is fairly big. It's fairly + + + align:start position:0% +proof is is fairly big. It's fairly +complicated but for the last three + + align:start position:0% +complicated but for the last three + + + align:start position:0% +complicated but for the last three +classes um I'm going to want to circle + + align:start position:0% +classes um I'm going to want to circle + + + align:start position:0% +classes um I'm going to want to circle +back to that and talk about the new + + align:start position:0% +back to that and talk about the new + + + align:start position:0% +back to that and talk about the new +ideas in that proof. + + align:start position:0% +ideas in that proof. + + + align:start position:0% +ideas in that proof. +So it's been a while since we talked + + align:start position:0% +So it's been a while since we talked + + + align:start position:0% +So it's been a while since we talked +about it. So I thought we could start by + + align:start position:0% +about it. So I thought we could start by + + + align:start position:0% +about it. So I thought we could start by +by we'll start just by writing down what + + align:start position:0% +by we'll start just by writing down what + + + align:start position:0% +by we'll start just by writing down what +is the statement. + + align:start position:0% +is the statement. + + + align:start position:0% +is the statement. +Um okay so this projection theory I I + + align:start position:0% +Um okay so this projection theory I I + + + align:start position:0% +Um okay so this projection theory I I +like to think of it as a um geometric + + align:start position:0% +like to think of it as a um geometric + + + align:start position:0% +like to think of it as a um geometric +measure theory analog of the sum troder + + align:start position:0% +measure theory analog of the sum troder + + + align:start position:0% +measure theory analog of the sum troder +theorem. So I'm going to start by + + align:start position:0% +theorem. So I'm going to start by + + + align:start position:0% +theorem. So I'm going to start by +writing down the summary TH + + align:start position:0% + + + + align:start position:0% + +start by writing down summary try + + align:start position:0% +start by writing down summary try + + + align:start position:0% +start by writing down summary try +and there are a bunch of different + + align:start position:0% +and there are a bunch of different + + + align:start position:0% +and there are a bunch of different +versions and we have I've picked out a + + align:start position:0% +versions and we have I've picked out a + + + align:start position:0% +versions and we have I've picked out a +particular version that sort of fits + + align:start position:0% +particular version that sort of fits + + + align:start position:0% +particular version that sort of fits +into the way the proof is going to go + + align:start position:0% +into the way the proof is going to go + + + align:start position:0% +into the way the proof is going to go +for this sharp projection theorem. Um + + align:start position:0% +for this sharp projection theorem. Um + + + align:start position:0% +for this sharp projection theorem. Um +okay so it says the following thing. So + + align:start position:0% +okay so it says the following thing. So + + + align:start position:0% +okay so it says the following thing. So +if E is a finite subset of R2 + + align:start position:0% +if E is a finite subset of R2 + + + align:start position:0% +if E is a finite subset of R2 +um and then L is a set of lines + + align:start position:0% + + + + align:start position:0% + +or let's say it this way for every X in + + align:start position:0% +or let's say it this way for every X in + + + align:start position:0% +or let's say it this way for every X in +E we'll have L X E is a set of S lines + + align:start position:0% +E we'll have L X E is a set of S lines + + + align:start position:0% +E we'll have L X E is a set of S lines +that go through X and L uh is the union + + align:start position:0% +that go through X and L uh is the union + + + align:start position:0% +that go through X and L uh is the union +over x + + align:start position:0% + + + + align:start position:0% + +we don't need this. + + align:start position:0% +we don't need this. + + + align:start position:0% +we don't need this. +So this set of lines L there's at least + + align:start position:0% +So this set of lines L there's at least + + + align:start position:0% +So this set of lines L there's at least +s of them through every point of e. + + align:start position:0% +s of them through every point of e. + + + align:start position:0% +s of them through every point of e. +Okay. Um so then conclusion is that the + + align:start position:0% +Okay. Um so then conclusion is that the + + + align:start position:0% +Okay. Um so then conclusion is that the +number of lines is at least the minimum + + align:start position:0% +number of lines is at least the minimum + + + align:start position:0% +number of lines is at least the minimum +of a couple of options. There's the size + + align:start position:0% +of a couple of options. There's the size + + + align:start position:0% +of a couple of options. There's the size +of E time S or there's the size of E to + + align:start position:0% +of E time S or there's the size of E to + + + align:start position:0% +of E time S or there's the size of E to +the 12 S to the three halfves. We'll + + align:start position:0% +the 12 S to the three halfves. We'll + + + align:start position:0% +the 12 S to the three halfves. We'll +call this um option A and option B. + + align:start position:0% + + + + align:start position:0% + +Okay, option A. It's very simple to + + align:start position:0% +Okay, option A. It's very simple to + + + align:start position:0% +Okay, option A. It's very simple to +imagine how this could arise. I have a + + align:start position:0% +imagine how this could arise. I have a + + + align:start position:0% +imagine how this could arise. I have a +bunch of points I set E and for each + + align:start position:0% +bunch of points I set E and for each + + + align:start position:0% +bunch of points I set E and for each +point I have S lines through it and + + align:start position:0% +point I have S lines through it and + + + align:start position:0% +point I have S lines through it and +they're just all different from each + + align:start position:0% +they're just all different from each + + + align:start position:0% +they're just all different from each +other. So I get E * S lex. + + align:start position:0% +other. So I get E * S lex. + + + align:start position:0% +other. So I get E * S lex. +Okay, option B + + align:start position:0% +Okay, option B + + + align:start position:0% +Okay, option B +is more more special, more remarkable, + + align:start position:0% +is more more special, more remarkable, + + + align:start position:0% +is more more special, more remarkable, +although not not that complicated. It's + + align:start position:0% +although not not that complicated. It's + + + align:start position:0% +although not not that complicated. It's +an integer grid and we talked about it a + + align:start position:0% +an integer grid and we talked about it a + + + align:start position:0% +an integer grid and we talked about it a +couple times in the beginning of the + + align:start position:0% +couple times in the beginning of the + + + align:start position:0% +couple times in the beginning of the +class. + + align:start position:0% + + + + align:start position:0% + +Okay. So in the integer grid + + align:start position:0% +Okay. So in the integer grid + + + align:start position:0% +Okay. So in the integer grid +that + + align:start position:0% +that + + + align:start position:0% +that +some sense. + + align:start position:0% + + + + align:start position:0% + +So we might have a lot of lines through + + align:start position:0% +So we might have a lot of lines through + + + align:start position:0% +So we might have a lot of lines through +each point but still each line is going + + align:start position:0% +each point but still each line is going + + + align:start position:0% +each point but still each line is going +through many points. So the total number + + align:start position:0% +through many points. So the total number + + + align:start position:0% +through many points. So the total number +of lines is a lot less than E * S. And + + align:start position:0% +of lines is a lot less than E * S. And + + + align:start position:0% +of lines is a lot less than E * S. And +if you work it out you get this. + + align:start position:0% + + + + align:start position:0% + +Okay. So that's the semir trotder + + align:start position:0% +Okay. So that's the semir trotder + + + align:start position:0% +Okay. So that's the semir trotder +theorem. Um, we saw early on that it + + align:start position:0% +theorem. Um, we saw early on that it + + + align:start position:0% +theorem. Um, we saw early on that it +implies a sharp projection theorem for + + align:start position:0% +implies a sharp projection theorem for + + + align:start position:0% +implies a sharp projection theorem for +finite sets in R2. And we're going to + + align:start position:0% +finite sets in R2. And we're going to + + + align:start position:0% +finite sets in R2. And we're going to +try to do some analog for like delta + + align:start position:0% +try to do some analog for like delta + + + align:start position:0% +try to do some analog for like delta +balls in R2. + + align:start position:0% +balls in R2. + + + align:start position:0% +balls in R2. +Okay, when we talk about delta balls, it + + align:start position:0% +Okay, when we talk about delta balls, it + + + align:start position:0% +Okay, when we talk about delta balls, it +matters how they're spaced. And the + + align:start position:0% +matters how they're spaced. And the + + + align:start position:0% +matters how they're spaced. And the +spacing condition we're going to talk + + align:start position:0% +spacing condition we're going to talk + + + align:start position:0% +spacing condition we're going to talk +about is the one that Pablo introduced, + + align:start position:0% +about is the one that Pablo introduced, + + + align:start position:0% +about is the one that Pablo introduced, +the delta SC condition. So I make a + + align:start position:0% +the delta SC condition. So I make a + + + align:start position:0% +the delta SC condition. So I make a +definition. + + align:start position:0% +definition. + + + align:start position:0% +definition. +So uh, if um, E is a subset of R to the + + align:start position:0% +So uh, if um, E is a subset of R to the + + + align:start position:0% +So uh, if um, E is a subset of R to the +D Let me say that E is delta S C F. Um, + + align:start position:0% +D Let me say that E is delta S C F. Um, + + + align:start position:0% +D Let me say that E is delta S C F. Um, +okay. So, first of all, I'm going to + + align:start position:0% +okay. So, first of all, I'm going to + + + align:start position:0% +okay. So, first of all, I'm going to +imagine here that E is contained in a + + align:start position:0% +imagine here that E is contained in a + + + align:start position:0% +imagine here that E is contained in a +unit ball + + align:start position:0% + + + + align:start position:0% + +or almost unit ball. Okay. And then um + + align:start position:0% +or almost unit ball. Okay. And then um + + + align:start position:0% +or almost unit ball. Okay. And then um +if you take E and you intersect it with + + align:start position:0% +if you take E and you intersect it with + + + align:start position:0% +if you take E and you intersect it with +a smaller ball, + + align:start position:0% + + + + align:start position:0% + +it's basically a new ball. If you take E + + align:start position:0% +it's basically a new ball. If you take E + + + align:start position:0% +it's basically a new ball. If you take E +and you intersect it with a smaller ball + + align:start position:0% +and you intersect it with a smaller ball + + + align:start position:0% +and you intersect it with a smaller ball +and take the delta covering number of + + align:start position:0% +and take the delta covering number of + + + align:start position:0% +and take the delta covering number of +that then that should be smaller than C + + align:start position:0% +that then that should be smaller than C + + + align:start position:0% +that then that should be smaller than C +* little R to the S times the delta + + align:start position:0% +* little R to the S times the delta + + + align:start position:0% +* little R to the S times the delta +covering number of the whole set. + + align:start position:0% +covering number of the whole set. + + + align:start position:0% +covering number of the whole set. +Um so for any X and for any R which + + align:start position:0% +Um so for any X and for any R which + + + align:start position:0% +Um so for any X and for any R which +should be at least delta + + align:start position:0% +should be at least delta + + + align:start position:0% +should be at least delta +so that's a delta SC it's a sort of a + + align:start position:0% +so that's a delta SC it's a sort of a + + + align:start position:0% +so that's a delta SC it's a sort of a +spacing condition on the set E that says + + align:start position:0% +spacing condition on the set E that says + + + align:start position:0% +spacing condition on the set E that says +that it's not too concentrated into any + + align:start position:0% +that it's not too concentrated into any + + + align:start position:0% +that it's not too concentrated into any +small + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +so here is the statement of the sharp + + align:start position:0% +so here is the statement of the sharp + + + align:start position:0% +so here is the statement of the sharp +projection theorem + + align:start position:0% +projection theorem + + + align:start position:0% +projection theorem +theorem of Orpinan Schmurkin Ren Wong + + align:start position:0% +theorem of Orpinan Schmurkin Ren Wong + + + align:start position:0% +theorem of Orpinan Schmurkin Ren Wong +from 2024. + + align:start position:0% +from 2024. + + + align:start position:0% +from 2024. +All right. So if E in R2 is a delta SC + + align:start position:0% +All right. So if E in R2 is a delta SC + + + align:start position:0% +All right. So if E in R2 is a delta SC +set + + align:start position:0% + + + + align:start position:0% + +then um every X in E will have a set of + + align:start position:0% +then um every X in E will have a set of + + + align:start position:0% +then um every X in E will have a set of +tubes T subX. + + align:start position:0% +tubes T subX. + + + align:start position:0% +tubes T subX. +This is a set of delta twos + + align:start position:0% + + + + align:start position:0% + +through x. + + align:start position:0% +through x. + + + align:start position:0% +through x. +Um, and sorry, E is going to be this is + + align:start position:0% +Um, and sorry, E is going to be this is + + + align:start position:0% +Um, and sorry, E is going to be this is +it's just a notation choice, but if I + + align:start position:0% +it's just a notation choice, but if I + + + align:start position:0% +it's just a notation choice, but if I +don't match my notes, I'll go bananas. + + align:start position:0% +don't match my notes, I'll go bananas. + + + align:start position:0% +don't match my notes, I'll go bananas. +It's a delta TC set. + + align:start position:0% +It's a delta TC set. + + + align:start position:0% +It's a delta TC set. +Uh, okay. And so for each point, there's + + align:start position:0% +Uh, okay. And so for each point, there's + + + align:start position:0% +Uh, okay. And so for each point, there's +a set of tubes through it. And this set + + align:start position:0% +a set of tubes through it. And this set + + + align:start position:0% +a set of tubes through it. And this set +of tubes + + align:start position:0% +of tubes + + + align:start position:0% +of tubes +is a delta S C set + + align:start position:0% +is a delta S C set + + + align:start position:0% +is a delta S C set +um in in S1. So let's make a picture. So + + align:start position:0% +um in in S1. So let's make a picture. So + + + align:start position:0% +um in in S1. So let's make a picture. So +we have a set E which um you may as well + + align:start position:0% +we have a set E which um you may as well + + + align:start position:0% +we have a set E which um you may as well +think of as a as a set of delta balls. + + align:start position:0% +think of as a as a set of delta balls. + + + align:start position:0% +think of as a as a set of delta balls. +So there's E. And then for each of these + + align:start position:0% +So there's E. And then for each of these + + + align:start position:0% +So there's E. And then for each of these +delta balls, it lies in a bunch of + + align:start position:0% +delta balls, it lies in a bunch of + + + align:start position:0% +delta balls, it lies in a bunch of +tubes. + + align:start position:0% + + + + align:start position:0% + +Okay. And we'll repeat for all of these + + align:start position:0% +Okay. And we'll repeat for all of these + + + align:start position:0% +Okay. And we'll repeat for all of these +other guys. Maybe this tube keeps going + + align:start position:0% +other guys. Maybe this tube keeps going + + + align:start position:0% +other guys. Maybe this tube keeps going +and goes through there and tube there. + + align:start position:0% +and goes through there and tube there. + + + align:start position:0% +and goes through there and tube there. +Okay. But so if this is x, those tubes + + align:start position:0% +Okay. But so if this is x, those tubes + + + align:start position:0% +Okay. But so if this is x, those tubes +there, that's TX + + align:start position:0% +there, that's TX + + + align:start position:0% +there, that's TX +and they point in different directions. + + align:start position:0% +and they point in different directions. + + + align:start position:0% +and they point in different directions. +We can think of the directions as being + + align:start position:0% +We can think of the directions as being + + + align:start position:0% +We can think of the directions as being +parameterized by S1. + + align:start position:0% +parameterized by S1. + + + align:start position:0% +parameterized by S1. +And they are a delta SC set in S1. Yeah. + + align:start position:0% +And they are a delta SC set in S1. Yeah. + + + align:start position:0% +And they are a delta SC set in S1. Yeah. +What if you multiple tubes that are in + + align:start position:0% +What if you multiple tubes that are in + + + align:start position:0% +What if you multiple tubes that are in +the same direction of being offset from + + align:start position:0% +the same direction of being offset from + + + align:start position:0% +the same direction of being offset from +each other that I guess delta contain + + align:start position:0% +each other that I guess delta contain + + + align:start position:0% +each other that I guess delta contain +the same point? How does that + + align:start position:0% +the same point? How does that + + + align:start position:0% +the same point? How does that +>> Yeah. So if you Right. So if I had this + + align:start position:0% +>> Yeah. So if you Right. So if I had this + + + align:start position:0% +>> Yeah. So if you Right. So if I had this +point and then I had + + align:start position:0% +point and then I had + + + align:start position:0% +point and then I had +those Oh, I see. Um yeah, we'll think of + + align:start position:0% +those Oh, I see. Um yeah, we'll think of + + + align:start position:0% +those Oh, I see. Um yeah, we'll think of +those as the same tube. + + align:start position:0% + + + + align:start position:0% + +Okay. Um, + + align:start position:0% +Okay. Um, + + + align:start position:0% +Okay. Um, +so the the question was, you know, if I + + align:start position:0% +so the the question was, you know, if I + + + align:start position:0% +so the the question was, you know, if I +have my delta ball, could I have two + + align:start position:0% +have my delta ball, could I have two + + + align:start position:0% +have my delta ball, could I have two +delta tubes going through it that are + + align:start position:0% +delta tubes going through it that are + + + align:start position:0% +delta tubes going through it that are +going in the same direction or within an + + align:start position:0% +going in the same direction or within an + + + align:start position:0% +going in the same direction or within an +angle delta of each other? And I'm going + + align:start position:0% +angle delta of each other? And I'm going + + + align:start position:0% +angle delta of each other? And I'm going +to think of those as being basically the + + align:start position:0% +to think of those as being basically the + + + align:start position:0% +to think of those as being basically the +same tube. + + align:start position:0% +same tube. + + + align:start position:0% +same tube. +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +Um, all right. Then t is the union overx + + align:start position:0% +Um, all right. Then t is the union overx + + + align:start position:0% +Um, all right. Then t is the union overx +tx + + align:start position:0% +tx + + + align:start position:0% +tx +which could be smaller than the sum of + + align:start position:0% +which could be smaller than the sum of + + + align:start position:0% +which could be smaller than the sum of +them because one tube might be in tx for + + align:start position:0% +them because one tube might be in tx for + + + align:start position:0% +them because one tube might be in tx for +two different x's. + + align:start position:0% +two different x's. + + + align:start position:0% +two different x's. +And the question is uh in terms of s and + + align:start position:0% +And the question is uh in terms of s and + + + align:start position:0% +And the question is uh in terms of s and +t how how big does this need to be? + + align:start position:0% +t how how big does this need to be? + + + align:start position:0% +t how how big does this need to be? +Okay. Um + + align:start position:0% +Okay. Um + + + align:start position:0% +Okay. Um +cool. Okay. So then the conclusion is + + align:start position:0% +cool. Okay. So then the conclusion is + + + align:start position:0% +cool. Okay. So then the conclusion is +that the size of t is bigger than okay + + align:start position:0% +that the size of t is bigger than okay + + + align:start position:0% +that the size of t is bigger than okay +there's a little complicated stuff + + align:start position:0% +there's a little complicated stuff + + + align:start position:0% +there's a little complicated stuff +cepsilon delta to the epsilon big c to + + align:start position:0% +cepsilon delta to the epsilon big c to + + + align:start position:0% +cepsilon delta to the epsilon big c to +the minus order of 1 + + align:start position:0% +the minus order of 1 + + + align:start position:0% +the minus order of 1 +um and then + + align:start position:0% +um and then + + + align:start position:0% +um and then +there's the minimum of okay so the e * s + + align:start position:0% +there's the minimum of okay so the e * s + + + align:start position:0% +there's the minimum of okay so the e * s +corresponds to delta to the minus t + + align:start position:0% +corresponds to delta to the minus t + + + align:start position:0% +corresponds to delta to the minus t +delta to the minus s the so this is this + + align:start position:0% +delta to the minus s the so this is this + + + align:start position:0% +delta to the minus s the so this is this +corresponds to There's somebody that + + align:start position:0% +corresponds to There's somebody that + + + align:start position:0% +corresponds to There's somebody that +corresponds to B. DeltaUS T / 2 Delta + + align:start position:0% +corresponds to B. DeltaUS T / 2 Delta + + + align:start position:0% +corresponds to B. DeltaUS T / 2 Delta +-3t / 2 that corresponds to B. And there + + align:start position:0% +-3t / 2 that corresponds to B. And there + + + align:start position:0% +-3t / 2 that corresponds to B. And there +is a new thing delta to the minus1 minus + + align:start position:0% +is a new thing delta to the minus1 minus + + + align:start position:0% +is a new thing delta to the minus1 minus +S that corresponds to C. Well, sorry + + align:start position:0% +S that corresponds to C. Well, sorry + + + align:start position:0% +S that corresponds to C. Well, sorry +that doesn't correspond to anything. + + align:start position:0% +that doesn't correspond to anything. + + + align:start position:0% +that doesn't correspond to anything. +There was no C up there. I will call it + + align:start position:0% +There was no C up there. I will call it + + + align:start position:0% +There was no C up there. I will call it +C. + + align:start position:0% +C. + + + align:start position:0% +C. +Okay. Who So who is C? + + align:start position:0% +Okay. Who So who is C? + + + align:start position:0% +Okay. Who So who is C? +Um, + + align:start position:0% + + + + align:start position:0% + +so C is a new phenomenon that has to do + + align:start position:0% +so C is a new phenomenon that has to do + + + align:start position:0% +so C is a new phenomenon that has to do +with the fact that these tubes and balls + + align:start position:0% +with the fact that these tubes and balls + + + align:start position:0% +with the fact that these tubes and balls +have a thickness which we didn't have up + + align:start position:0% +have a thickness which we didn't have up + + + align:start position:0% +have a thickness which we didn't have up +there. So here E could just be a could + + align:start position:0% +there. So here E could just be a could + + + align:start position:0% +there. So here E could just be a could +be any set + + align:start position:0% + + + + align:start position:0% + +and then T is a random set + + align:start position:0% +and then T is a random set + + + align:start position:0% +and then T is a random set +of delta to the minus1 minus S or so + + align:start position:0% +of delta to the minus1 minus S or so + + + align:start position:0% +of delta to the minus1 minus S or so +tubes. + + align:start position:0% +tubes. + + + align:start position:0% +tubes. +And the probability that a delta tube + + align:start position:0% +And the probability that a delta tube + + + align:start position:0% +And the probability that a delta tube +goes through a given point is delta. So + + align:start position:0% +goes through a given point is delta. So + + + align:start position:0% +goes through a given point is delta. So +a typical point TX would would + + align:start position:0% +a typical point TX would would + + + align:start position:0% +a typical point TX would would +essentially be a random + + align:start position:0% +essentially be a random + + + align:start position:0% +essentially be a random +set of around delta to the minus s tubes + + align:start position:0% +set of around delta to the minus s tubes + + + align:start position:0% +set of around delta to the minus s tubes +and a random set there might be a couple + + align:start position:0% +and a random set there might be a couple + + + align:start position:0% +and a random set there might be a couple +that are close together but on the whole + + align:start position:0% +that are close together but on the whole + + + align:start position:0% +that are close together but on the whole +that would be that would be a delta s + + align:start position:0% +that would be that would be a delta s + + + align:start position:0% +that would be that would be a delta s +set of tubes. + + align:start position:0% +set of tubes. + + + align:start position:0% +set of tubes. +Okay so that's where this new option + + align:start position:0% +Okay so that's where this new option + + + align:start position:0% +Okay so that's where this new option +comes from. Cool. Okay. Yeah. and option + + align:start position:0% +comes from. Cool. Okay. Yeah. and option + + + align:start position:0% +comes from. Cool. Okay. Yeah. and option +B or is one of the exponents supposed to + + align:start position:0% +B or is one of the exponents supposed to + + + align:start position:0% +B or is one of the exponents supposed to +be an S fun? + + align:start position:0% +be an S fun? + + + align:start position:0% +be an S fun? +>> Yes, thank you. + + align:start position:0% +>> Yes, thank you. + + + align:start position:0% +>> Yes, thank you. +That's supposed to be an S, + + align:start position:0% +That's supposed to be an S, + + + align:start position:0% +That's supposed to be an S, +right? Okay, so let's put these on top + + align:start position:0% +right? Okay, so let's put these on top + + + align:start position:0% +right? Okay, so let's put these on top +of each other for a second. + + align:start position:0% +of each other for a second. + + + align:start position:0% +of each other for a second. +So the size of E corresponds to the + + align:start position:0% +So the size of E corresponds to the + + + align:start position:0% +So the size of E corresponds to the +delta to the minus T and big S + + align:start position:0% +delta to the minus T and big S + + + align:start position:0% +delta to the minus T and big S +corresponds to delta to the minus little + + align:start position:0% +corresponds to delta to the minus little + + + align:start position:0% +corresponds to delta to the minus little +S. And so so those match up + + align:start position:0% +S. And so so those match up + + + align:start position:0% +S. And so so those match up +and then C is something new. + + align:start position:0% + + + + align:start position:0% + +Okay, good. Now, I realized I forgot one + + align:start position:0% +Okay, good. Now, I realized I forgot one + + + align:start position:0% +Okay, good. Now, I realized I forgot one +hypothesis that I'm going to add and + + align:start position:0% +hypothesis that I'm going to add and + + + align:start position:0% +hypothesis that I'm going to add and +then we'll pause and you can look at + + align:start position:0% +then we'll pause and you can look at + + + align:start position:0% +then we'll pause and you can look at +these statements. + + align:start position:0% +these statements. + + + align:start position:0% +these statements. +Okay, so + + align:start position:0% +Okay, so + + + align:start position:0% +Okay, so +we needed one more hypothesis in our + + align:start position:0% +we needed one more hypothesis in our + + + align:start position:0% +we needed one more hypothesis in our +list of hypotheses, which is that this S + + align:start position:0% +list of hypotheses, which is that this S + + + align:start position:0% +list of hypotheses, which is that this S +should be bigger than one. + + align:start position:0% +should be bigger than one. + + + align:start position:0% +should be bigger than one. +You see, if I just had one line going + + align:start position:0% +You see, if I just had one line going + + + align:start position:0% +You see, if I just had one line going +through each of these points, then I + + align:start position:0% +through each of these points, then I + + + align:start position:0% +through each of these points, then I +could just have one line and a bunch of + + align:start position:0% +could just have one line and a bunch of + + + align:start position:0% +could just have one line and a bunch of +points on it and one is not bigger than + + align:start position:0% +points on it and one is not bigger than + + + align:start position:0% +points on it and one is not bigger than +this. + + align:start position:0% +this. + + + align:start position:0% +this. +Okay, so that's a special case. And + + align:start position:0% +Okay, so that's a special case. And + + + align:start position:0% +Okay, so that's a special case. And +there is an analogous condition here in + + align:start position:0% +there is an analogous condition here in + + + align:start position:0% +there is an analogous condition here in +our list of hypotheses. We need little s + + align:start position:0% +our list of hypotheses. We need little s + + + align:start position:0% +our list of hypotheses. We need little s +to be bigger than zero. This corresponds + + align:start position:0% +to be bigger than zero. This corresponds + + + align:start position:0% +to be bigger than zero. This corresponds +to having not just one tube through each + + align:start position:0% +to having not just one tube through each + + + align:start position:0% +to having not just one tube through each +of these points, but pretty many. + + align:start position:0% + + + + align:start position:0% + +Okay, so that's the statement of summary + + align:start position:0% +Okay, so that's the statement of summary + + + align:start position:0% +Okay, so that's the statement of summary +trotder and the parallel statement of + + align:start position:0% +trotder and the parallel statement of + + + align:start position:0% +trotder and the parallel statement of +this is the firstenberg set conjecture + + align:start position:0% +this is the firstenberg set conjecture + + + align:start position:0% +this is the firstenberg set conjecture +um proven just recently. + + align:start position:0% +um proven just recently. + + + align:start position:0% +um proven just recently. +So let's pause there to digest and see + + align:start position:0% +So let's pause there to digest and see + + + align:start position:0% +So let's pause there to digest and see +if there are questions or comments about + + align:start position:0% +if there are questions or comments about + + + align:start position:0% +if there are questions or comments about +the statement of this theorem. + + align:start position:0% + + + + align:start position:0% + +Yeah, + + align:start position:0% +Yeah, + + + align:start position:0% +Yeah, +>> I'm still having a hard time + + align:start position:0% +>> I'm still having a hard time + + + align:start position:0% +>> I'm still having a hard time +understanding what's going on in + + align:start position:0% +understanding what's going on in + + + align:start position:0% +understanding what's going on in +case C. Would it be possible to draw a + + align:start position:0% +case C. Would it be possible to draw a + + + align:start position:0% +case C. Would it be possible to draw a +typical example? + + align:start position:0% +typical example? + + + align:start position:0% +typical example? +>> Yeah, let's draw case C. Okay, so E + + align:start position:0% +>> Yeah, let's draw case C. Okay, so E + + + align:start position:0% +>> Yeah, let's draw case C. Okay, so E +could go anywhere + + align:start position:0% + + + + align:start position:0% + +and then + + align:start position:0% +and then + + + align:start position:0% +and then +um I'm going to draw a random set of + + align:start position:0% +um I'm going to draw a random set of + + + align:start position:0% +um I'm going to draw a random set of +delt of of of tubes a bunch of them. So + + align:start position:0% +delt of of of tubes a bunch of them. So + + + align:start position:0% +delt of of of tubes a bunch of them. So +um okay, so here I go. + + align:start position:0% + + + + align:start position:0% + +So I I drew these tubes + + align:start position:0% +So I I drew these tubes + + + align:start position:0% +So I I drew these tubes +or I tried to do it without thinking at + + align:start position:0% +or I tried to do it without thinking at + + + align:start position:0% +or I tried to do it without thinking at +all about where the points are. There + + align:start position:0% +all about where the points are. There + + + align:start position:0% +all about where the points are. There +was nothing clever going on. + + align:start position:0% +was nothing clever going on. + + + align:start position:0% +was nothing clever going on. +Um but uh I drew a whole lot of them and + + align:start position:0% +Um but uh I drew a whole lot of them and + + + align:start position:0% +Um but uh I drew a whole lot of them and +uh one over a delta fraction if if I + + align:start position:0% +uh one over a delta fraction if if I + + + align:start position:0% +uh one over a delta fraction if if I +draw a random tube the probability that + + align:start position:0% +draw a random tube the probability that + + + align:start position:0% +draw a random tube the probability that +goes through here is delta. So if I draw + + align:start position:0% +goes through here is delta. So if I draw + + + align:start position:0% +goes through here is delta. So if I draw +uh m o times 1 over delta random tubes, + + align:start position:0% +uh m o times 1 over delta random tubes, + + + align:start position:0% +uh m o times 1 over delta random tubes, +I'll have about m of them going through + + align:start position:0% +I'll have about m of them going through + + + align:start position:0% +I'll have about m of them going through +this point. So let's say I do that. So I + + align:start position:0% +this point. So let's say I do that. So I + + + align:start position:0% +this point. So let's say I do that. So I +have about m tubes going through this + + align:start position:0% +have about m tubes going through this + + + align:start position:0% +have about m tubes going through this +point. Now what directions will they + + align:start position:0% +point. Now what directions will they + + + align:start position:0% +point. Now what directions will they +point in? Well, they'll point in random + + align:start position:0% +point in? Well, they'll point in random + + + align:start position:0% +point in? Well, they'll point in random +directions. And a random direction, a + + align:start position:0% +directions. And a random direction, a + + + align:start position:0% +directions. And a random direction, a +random set is a is a delta SC c set + + align:start position:0% +random set is a is a delta SC c set + + + align:start position:0% +random set is a is a delta SC c set +where s where delta to the minus s is + + align:start position:0% +where s where delta to the minus s is + + + align:start position:0% +where s where delta to the minus s is +the number of points. + + align:start position:0% +the number of points. + + + align:start position:0% +the number of points. +So so that's that's why we have this + + align:start position:0% + + + + align:start position:0% + +Okay, other questions or comments? + + align:start position:0% + + + + align:start position:0% + +Okay, so now let's start talk about the + + align:start position:0% +Okay, so now let's start talk about the + + + align:start position:0% +Okay, so now let's start talk about the +history of work on this problem. + + align:start position:0% +history of work on this problem. + + + align:start position:0% +history of work on this problem. +Um, and the going through the history of + + align:start position:0% +Um, and the going through the history of + + + align:start position:0% +Um, and the going through the history of +work on the problem will also be an + + align:start position:0% +work on the problem will also be an + + + align:start position:0% +work on the problem will also be an +excuse to kind of recap a big section + + align:start position:0% +excuse to kind of recap a big section + + + align:start position:0% +excuse to kind of recap a big section +big chunks of our class. + + align:start position:0% +big chunks of our class. + + + align:start position:0% +big chunks of our class. +So + + align:start position:0% +So + + + align:start position:0% +So +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +history of work slash + + align:start position:0% +history of work slash + + + align:start position:0% +history of work slash +recap of the class. + + align:start position:0% +recap of the class. + + + align:start position:0% +recap of the class. +Okay. So first I'll do what I'll call + + align:start position:0% +Okay. So first I'll do what I'll call + + + align:start position:0% +Okay. So first I'll do what I'll call +classical bounds which are uh + + align:start position:0% +classical bounds which are uh + + + align:start position:0% +classical bounds which are uh +essentially due to calfman and falconer + + align:start position:0% + + + + align:start position:0% + +and they were sort of written up in the + + align:start position:0% +and they were sort of written up in the + + + align:start position:0% +and they were sort of written up in the +context of this theorem. Calfman and + + align:start position:0% +context of this theorem. Calfman and + + + align:start position:0% +context of this theorem. Calfman and +falconer were talking about projection + + align:start position:0% +falconer were talking about projection + + + align:start position:0% +falconer were talking about projection +theory. This is a little bit more + + align:start position:0% +theory. This is a little bit more + + + align:start position:0% +theory. This is a little bit more +general um but they were written up. So + + align:start position:0% +general um but they were written up. So + + + align:start position:0% +general um but they were written up. So +this kofman kman and falconer were in + + align:start position:0% +this kofman kman and falconer were in + + + align:start position:0% +this kofman kman and falconer were in +the 60s and 70s. a pretty long time ago + + align:start position:0% +the 60s and 70s. a pretty long time ago + + + align:start position:0% +the 60s and 70s. a pretty long time ago +and then um adapted a bit by Wolf. + + align:start position:0% +and then um adapted a bit by Wolf. + + + align:start position:0% +and then um adapted a bit by Wolf. +Okay, the first classical argument is + + align:start position:0% +Okay, the first classical argument is + + + align:start position:0% +Okay, the first classical argument is +double counting. + + align:start position:0% + + + + align:start position:0% + +There actually two slightly different + + align:start position:0% +There actually two slightly different + + + align:start position:0% +There actually two slightly different +ways of dueling double counting and I'll + + align:start position:0% +ways of dueling double counting and I'll + + + align:start position:0% +ways of dueling double counting and I'll +tell you what they give. The first way + + align:start position:0% +tell you what they give. The first way + + + align:start position:0% +tell you what they give. The first way +gives that if s is at least t + + align:start position:0% +gives that if s is at least t + + + align:start position:0% +gives that if s is at least t +um then um the number of tubes is at + + align:start position:0% +um then um the number of tubes is at + + + align:start position:0% +um then um the number of tubes is at +least option a + + align:start position:0% +least option a + + + align:start position:0% +least option a +and this is sharp. + + align:start position:0% +and this is sharp. + + + align:start position:0% +and this is sharp. +Okay. So let's think about what it + + align:start position:0% +Okay. So let's think about what it + + + align:start position:0% +Okay. So let's think about what it +means. + + align:start position:0% +means. + + + align:start position:0% +means. +So s is at least t. That means that the + + align:start position:0% +So s is at least t. That means that the + + + align:start position:0% +So s is at least t. That means that the +number of directions through each point + + align:start position:0% +number of directions through each point + + + align:start position:0% +number of directions through each point +is bigger than the number of points. + + align:start position:0% +is bigger than the number of points. + + + align:start position:0% +is bigger than the number of points. +So um draw a little picture to the side + + align:start position:0% +So um draw a little picture to the side + + + align:start position:0% +So um draw a little picture to the side +here. + + align:start position:0% +here. + + + align:start position:0% +here. +So I have a few points, not very many. + + align:start position:0% +So I have a few points, not very many. + + + align:start position:0% +So I have a few points, not very many. +And then through each tube I'm going to + + align:start position:0% +And then through each tube I'm going to + + + align:start position:0% +And then through each tube I'm going to +draw through each point I'm going to + + align:start position:0% +draw through each point I'm going to + + + align:start position:0% +draw through each point I'm going to +draw a bunch of tubes. And the number of + + align:start position:0% +draw a bunch of tubes. And the number of + + + align:start position:0% +draw a bunch of tubes. And the number of +directions is bigger than the number of + + align:start position:0% +directions is bigger than the number of + + + align:start position:0% +directions is bigger than the number of +points. So I have a picture like this. + + align:start position:0% +points. So I have a picture like this. + + + align:start position:0% +points. So I have a picture like this. +So what you see is that most of these + + align:start position:0% +So what you see is that most of these + + + align:start position:0% +So what you see is that most of these +tubes don't go through any other point + + align:start position:0% +tubes don't go through any other point + + + align:start position:0% +tubes don't go through any other point +besides the initial point. + + align:start position:0% +besides the initial point. + + + align:start position:0% +besides the initial point. +Uh and that gives an easy estimate for + + align:start position:0% +Uh and that gives an easy estimate for + + + align:start position:0% +Uh and that gives an easy estimate for +the number of tubes + + align:start position:0% +the number of tubes + + + align:start position:0% +the number of tubes +has to be at least the number of points + + align:start position:0% +has to be at least the number of points + + + align:start position:0% +has to be at least the number of points +times you know the number of tubes + + align:start position:0% +times you know the number of tubes + + + align:start position:0% +times you know the number of tubes +through. + + align:start position:0% +through. + + + align:start position:0% +through. +Okay. There is another way to do double + + align:start position:0% +Okay. There is another way to do double + + + align:start position:0% +Okay. There is another way to do double +counting and it says that in general so + + align:start position:0% +counting and it says that in general so + + + align:start position:0% +counting and it says that in general so +just if s is bigger than zero which + + align:start position:0% +just if s is bigger than zero which + + + align:start position:0% +just if s is bigger than zero which +we've been assuming then the number of + + align:start position:0% +we've been assuming then the number of + + + align:start position:0% +we've been assuming then the number of +tubes is at least delta to the minus 2s. + + align:start position:0% + + + + align:start position:0% + +Um + + align:start position:0% + + + + align:start position:0% + +um so + + align:start position:0% + + + + align:start position:0% + +let me just let me just leave this one + + align:start position:0% +let me just let me just leave this one + + + align:start position:0% +let me just let me just leave this one +as an exercise. We've done we've done + + align:start position:0% +as an exercise. We've done we've done + + + align:start position:0% +as an exercise. We've done we've done +some double counting. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Um then there was a forier method + + align:start position:0% + + + + align:start position:0% + +um that we did in in class and the + + align:start position:0% +um that we did in in class and the + + + align:start position:0% +um that we did in in class and the +forier method showed that t was bigger + + align:start position:0% +forier method showed that t was bigger + + + align:start position:0% +forier method showed that t was bigger +than the minimum of two things. One of + + align:start position:0% +than the minimum of two things. One of + + + align:start position:0% +than the minimum of two things. One of +them is option C and the other one is + + align:start position:0% +them is option C and the other one is + + + align:start position:0% +them is option C and the other one is +delta to the 1 - S times option A. + + align:start position:0% + + + + align:start position:0% + +And um so this number is smaller than + + align:start position:0% +And um so this number is smaller than + + + align:start position:0% +And um so this number is smaller than +one. So this is smaller than A. So this + + align:start position:0% +one. So this is smaller than A. So this + + + align:start position:0% +one. So this is smaller than A. So this +isn't sharp uh unless we're so lucky + + align:start position:0% +isn't sharp uh unless we're so lucky + + + align:start position:0% +isn't sharp uh unless we're so lucky +that S is equal to one in which case + + align:start position:0% +that S is equal to one in which case + + + align:start position:0% +that S is equal to one in which case +this is the minimum of A and C. And + + align:start position:0% +this is the minimum of A and C. And + + + align:start position:0% +this is the minimum of A and C. And +that's that's good. So this is sharp + + align:start position:0% +that's that's good. So this is sharp + + + align:start position:0% +that's that's good. So this is sharp +if s is equal to one. + + align:start position:0% + + + + align:start position:0% + +Okay. So I won't redo this one but this + + align:start position:0% +Okay. So I won't redo this one but this + + + align:start position:0% +Okay. So I won't redo this one but this +is uh just the forier method that we did + + align:start position:0% +is uh just the forier method that we did + + + align:start position:0% +is uh just the forier method that we did +in the in the third week of of our + + align:start position:0% +in the in the third week of of our + + + align:start position:0% +in the in the third week of of our +class. + + align:start position:0% +class. + + + align:start position:0% +class. +Okay. So the classical methods are + + align:start position:0% +Okay. So the classical methods are + + + align:start position:0% +Okay. So the classical methods are +occasionally sharp but usually not + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +um and um okay so another comment about + + align:start position:0% +um and um okay so another comment about + + + align:start position:0% +um and um okay so another comment about +this story that about why why why this + + align:start position:0% +this story that about why why why this + + + align:start position:0% +this story that about why why why this +is difficult is that some of these + + align:start position:0% +is difficult is that some of these + + + align:start position:0% +is difficult is that some of these +statements are fields dependent. They're + + align:start position:0% +statements are fields dependent. They're + + + align:start position:0% +statements are fields dependent. They're +true over R, but they're false over C. + + align:start position:0% +true over R, but they're false over C. + + + align:start position:0% +true over R, but they're false over C. +But others others uh are true in all + + align:start position:0% +But others others uh are true in all + + + align:start position:0% +But others others uh are true in all +fields. Um so if we go back to the + + align:start position:0% +fields. Um so if we go back to the + + + align:start position:0% +fields. Um so if we go back to the +beginning, + + align:start position:0% +beginning, + + + align:start position:0% +beginning, +the summary detrader theorem is true in + + align:start position:0% +the summary detrader theorem is true in + + + align:start position:0% +the summary detrader theorem is true in +both R and C although it's not true in + + align:start position:0% +both R and C although it's not true in + + + align:start position:0% +both R and C although it's not true in +all fields + + align:start position:0% + + + + align:start position:0% + +and is + + align:start position:0% +and is + + + align:start position:0% +and is +all C in some in some finite fields. + + align:start position:0% +all C in some in some finite fields. + + + align:start position:0% +all C in some in some finite fields. +Well, it's really it's false in all + + align:start position:0% +Well, it's really it's false in all + + + align:start position:0% +Well, it's really it's false in all +kinds of things. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +this theorem here is uh true r but it is + + align:start position:0% +this theorem here is uh true r but it is + + + align:start position:0% +this theorem here is uh true r but it is +false over + + align:start position:0% +false over + + + align:start position:0% +false over +and that counter examples kind of + + align:start position:0% +and that counter examples kind of + + + align:start position:0% +and that counter examples kind of +haunted all of us who have been working + + align:start position:0% +haunted all of us who have been working + + + align:start position:0% +haunted all of us who have been working +on this. + + align:start position:0% +on this. + + + align:start position:0% +on this. +And one feature of these classical + + align:start position:0% +And one feature of these classical + + + align:start position:0% +And one feature of these classical +methods is that they don't distinguish. + + align:start position:0% +methods is that they don't distinguish. + + + align:start position:0% +methods is that they don't distinguish. +um they work + + align:start position:0% +um they work + + + align:start position:0% +um they work +over R or C. + + align:start position:0% + + + + align:start position:0% + +Okay. Um okay. So to prove this theorem + + align:start position:0% +Okay. Um okay. So to prove this theorem + + + align:start position:0% +Okay. Um okay. So to prove this theorem +we have to distinguish R and C. So we'll + + align:start position:0% +we have to distinguish R and C. So we'll + + + align:start position:0% +we have to distinguish R and C. So we'll +have to do something which in some way + + align:start position:0% +have to do something which in some way + + + align:start position:0% +have to do something which in some way +is different from these. Um and the next + + align:start position:0% +is different from these. Um and the next + + + align:start position:0% +is different from these. Um and the next +phase in the history is begins with Bans + + align:start position:0% +phase in the history is begins with Bans + + + align:start position:0% +phase in the history is begins with Bans +projection theorem. And I it's a phase + + align:start position:0% +projection theorem. And I it's a phase + + + align:start position:0% +projection theorem. And I it's a phase +that I'll label as epsilon improvements. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +So for quite a while actually there + + align:start position:0% +So for quite a while actually there + + + align:start position:0% +So for quite a while actually there +really was no progress on these + + align:start position:0% +really was no progress on these + + + align:start position:0% +really was no progress on these +classical methods. These ma classical + + align:start position:0% +classical methods. These ma classical + + + align:start position:0% +classical methods. These ma classical +methods are from the 60s and 70s. Wolf + + align:start position:0% +methods are from the 60s and 70s. Wolf + + + align:start position:0% +methods are from the 60s and 70s. Wolf +adapted them to slightly more general + + align:start position:0% +adapted them to slightly more general + + + align:start position:0% +adapted them to slightly more general +setting but um but basically there was + + align:start position:0% +setting but um but basically there was + + + align:start position:0% +setting but um but basically there was +no progress for a long time. And phase + + align:start position:0% +no progress for a long time. And phase + + + align:start position:0% +no progress for a long time. And phase +two is the phase of epsilon + + align:start position:0% +two is the phase of epsilon + + + align:start position:0% +two is the phase of epsilon +improvements. + + align:start position:0% + + + + align:start position:0% + +And the dates of this phase are from + + align:start position:0% +And the dates of this phase are from + + + align:start position:0% +And the dates of this phase are from +around 2000 to very recently. + + align:start position:0% +around 2000 to very recently. + + + align:start position:0% +around 2000 to very recently. +Um, okay. Where is the Borgan projection + + align:start position:0% +Um, okay. Where is the Borgan projection + + + align:start position:0% +Um, okay. Where is the Borgan projection +theorem? + + align:start position:0% + + + + align:start position:0% + +And it implies with a little work but + + align:start position:0% +And it implies with a little work but + + + align:start position:0% +And it implies with a little work but +not that much work an improvement over + + align:start position:0% +not that much work an improvement over + + + align:start position:0% +not that much work an improvement over +the classical methods in a very + + align:start position:0% +the classical methods in a very + + + align:start position:0% +the classical methods in a very +particular situation. + + align:start position:0% +particular situation. + + + align:start position:0% +particular situation. +So it says if t is one and s is 12 + + align:start position:0% +So it says if t is one and s is 12 + + + align:start position:0% +So it says if t is one and s is 12 +then + + align:start position:0% +then + + + align:start position:0% +then +this number of tubes is at least delta + + align:start position:0% +this number of tubes is at least delta + + + align:start position:0% +this number of tubes is at least delta +to the minus1 + + align:start position:0% +to the minus1 + + + align:start position:0% +to the minus1 +minus some epsilon we're g + + align:start position:0% +minus some epsilon we're g + + + align:start position:0% +minus some epsilon we're g +um so if you just plug in the classical + + align:start position:0% +um so if you just plug in the classical + + + align:start position:0% +um so if you just plug in the classical +bounds up there it would give this and + + align:start position:0% +bounds up there it would give this and + + + align:start position:0% +bounds up there it would give this and +there's an improvement although only for + + align:start position:0% +there's an improvement although only for + + + align:start position:0% +there's an improvement although only for +a rather particular for one particular + + align:start position:0% +a rather particular for one particular + + + align:start position:0% +a rather particular for one particular +choice of the parameters. + + align:start position:0% + + + + align:start position:0% + +Okay. Um so that was uh in 2000 + + align:start position:0% +Okay. Um so that was uh in 2000 + + + align:start position:0% +Okay. Um so that was uh in 2000 +and the next improvement + + align:start position:0% +and the next improvement + + + align:start position:0% +and the next improvement +is a theorem of Orphin and Schmurkin + + align:start position:0% +is a theorem of Orphin and Schmurkin + + + align:start position:0% +is a theorem of Orphin and Schmurkin +from 2021. + + align:start position:0% +from 2021. + + + align:start position:0% +from 2021. +And you could think of it as a + + align:start position:0% +And you could think of it as a + + + align:start position:0% +And you could think of it as a +generalization of this. It gives an + + align:start position:0% +generalization of this. It gives an + + + align:start position:0% +generalization of this. It gives an +epsilon improvement but in not just for + + align:start position:0% +epsilon improvement but in not just for + + + align:start position:0% +epsilon improvement but in not just for +this special value of the parameters but + + align:start position:0% +this special value of the parameters but + + + align:start position:0% +this special value of the parameters but +for lots of values of the parameters. So + + align:start position:0% +for lots of values of the parameters. So + + + align:start position:0% +for lots of values of the parameters. So +they proved that if t is bigger than s + + align:start position:0% +they proved that if t is bigger than s + + + align:start position:0% +they proved that if t is bigger than s +uh which is bigger than zero + + align:start position:0% +uh which is bigger than zero + + + align:start position:0% +uh which is bigger than zero +then + + align:start position:0% +then + + + align:start position:0% +then +the number of tubes is at least delta to + + align:start position:0% +the number of tubes is at least delta to + + + align:start position:0% +the number of tubes is at least delta to +the minus 2s minus epsilon. + + align:start position:0% +the minus 2s minus epsilon. + + + align:start position:0% +the minus 2s minus epsilon. +So delta to the minus 2s is what you + + align:start position:0% +So delta to the minus 2s is what you + + + align:start position:0% +So delta to the minus 2s is what you +would get classically by double + + align:start position:0% +would get classically by double + + + align:start position:0% +would get classically by double +counting. It takes half a page and then + + align:start position:0% +counting. It takes half a page and then + + + align:start position:0% +counting. It takes half a page and then +uh after 50 years and 50 pages you can + + align:start position:0% +uh after 50 years and 50 pages you can + + + align:start position:0% +uh after 50 years and 50 pages you can +get this. + + align:start position:0% + + + + align:start position:0% + +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +So in our class we + + align:start position:0% + + + + align:start position:0% + +said a lot about the proof of the BADN + + align:start position:0% +said a lot about the proof of the BADN + + + align:start position:0% +said a lot about the proof of the BADN +projection theorem. I don't I wouldn't + + align:start position:0% +projection theorem. I don't I wouldn't + + + align:start position:0% +projection theorem. I don't I wouldn't +actually wouldn't say that we proved + + align:start position:0% +actually wouldn't say that we proved + + + align:start position:0% +actually wouldn't say that we proved +every did every step every detail and um + + align:start position:0% +every did every step every detail and um + + + align:start position:0% +every did every step every detail and um +uh this one. Okay, let me say so we + + align:start position:0% +uh this one. Okay, let me say so we + + + align:start position:0% +uh this one. Okay, let me say so we +haven't proven this in but let me just + + align:start position:0% +haven't proven this in but let me just + + + align:start position:0% +haven't proven this in but let me just +say something about the proof. So this + + align:start position:0% +say something about the proof. So this + + + align:start position:0% +say something about the proof. So this +is based on reg projection theorem + + align:start position:0% +is based on reg projection theorem + + + align:start position:0% +is based on reg projection theorem +um plus a bunch of ideas. + + align:start position:0% + + + + align:start position:0% + +Okay. And so an emotional reaction that + + align:start position:0% +Okay. And so an emotional reaction that + + + align:start position:0% +Okay. And so an emotional reaction that +I had to to learning this and going + + align:start position:0% +I had to to learning this and going + + + align:start position:0% +I had to to learning this and going +through it with you is that it is it's + + align:start position:0% +through it with you is that it is it's + + + align:start position:0% +through it with you is that it is it's +hard work + + align:start position:0% + + + + align:start position:0% + +and also epsilon is really tiny. seems + + align:start position:0% +and also epsilon is really tiny. seems + + + align:start position:0% +and also epsilon is really tiny. seems +like you know the harder the clever we + + align:start position:0% +like you know the harder the clever we + + + align:start position:0% +like you know the harder the clever we +are the harder we work we keep making + + align:start position:0% +are the harder we work we keep making + + + align:start position:0% +are the harder we work we keep making +epsilon smaller + + align:start position:0% + + + + align:start position:0% + +okay so this was the second phase of the + + align:start position:0% +okay so this was the second phase of the + + + align:start position:0% +okay so this was the second phase of the +history where people were able to make + + align:start position:0% +history where people were able to make + + + align:start position:0% +history where people were able to make +epsilon improvements I could also + + align:start position:0% +epsilon improvements I could also + + + align:start position:0% +epsilon improvements I could also +mention other theorems not about this + + align:start position:0% +mention other theorems not about this + + + align:start position:0% +mention other theorems not about this +exact problem but but in a similar + + align:start position:0% +exact problem but but in a similar + + + align:start position:0% +exact problem but but in a similar +spirit so for many different problems it + + align:start position:0% +spirit so for many different problems it + + + align:start position:0% +spirit so for many different problems it +was possible to make an epsilon + + align:start position:0% +was possible to make an epsilon + + + align:start position:0% +was possible to make an epsilon +improvement um by using burgans's + + align:start position:0% +improvement um by using burgans's + + + align:start position:0% +improvement um by using burgans's +projection theorem and by using and + + align:start position:0% +projection theorem and by using and + + + align:start position:0% +projection theorem and by using and +developing ideas related to the ones we + + align:start position:0% +developing ideas related to the ones we + + + align:start position:0% +developing ideas related to the ones we +put there. Uh okay, so it was hard work. + + align:start position:0% +put there. Uh okay, so it was hard work. + + + align:start position:0% +put there. Uh okay, so it was hard work. +Epsilon was really tiny. But one + + align:start position:0% +Epsilon was really tiny. But one + + + align:start position:0% +Epsilon was really tiny. But one +positive thing about it is that it did + + align:start position:0% +positive thing about it is that it did + + + align:start position:0% +positive thing about it is that it did +distinguish uh R from C. So both of + + align:start position:0% +distinguish uh R from C. So both of + + + align:start position:0% +distinguish uh R from C. So both of +these theorems are false over C. So we + + align:start position:0% +these theorems are false over C. So we + + + align:start position:0% +these theorems are false over C. So we +did start to do that. + + align:start position:0% +did start to do that. + + + align:start position:0% +did start to do that. +Okay. Um cool. So this theorem + + align:start position:0% +Okay. Um cool. So this theorem + + + align:start position:0% +Okay. Um cool. So this theorem +represents a third stage in the history + + align:start position:0% +represents a third stage in the history + + + align:start position:0% +represents a third stage in the history +where we didn't just improve by an + + align:start position:0% +where we didn't just improve by an + + + align:start position:0% +where we didn't just improve by an +epsilon over the classical results but + + align:start position:0% +epsilon over the classical results but + + + align:start position:0% +epsilon over the classical results but +we improved substantially and in fact + + align:start position:0% +we improved substantially and in fact + + + align:start position:0% +we improved substantially and in fact +proved people proved the sharp result. + + align:start position:0% +proved people proved the sharp result. + + + align:start position:0% +proved people proved the sharp result. +This is so so I should mention this. + + align:start position:0% +This is so so I should mention this. + + + align:start position:0% +This is so so I should mention this. +This is sharp. + + align:start position:0% + + + + align:start position:0% + +This is sharp + + align:start position:0% +This is sharp + + + align:start position:0% +This is sharp +for any essence. + + align:start position:0% + + + + align:start position:0% + +>> Yeah. + + align:start position:0% +>> Yeah. + + + align:start position:0% +>> Yeah. +>> Is that delicac + + align:start position:0% + + + + align:start position:0% + +or + + align:start position:0% +or + + + align:start position:0% +or +>> Yeah, it's sharp up to this. So + + align:start position:0% +>> Yeah, it's sharp up to this. So + + + align:start position:0% +>> Yeah, it's sharp up to this. So +sharp up to the delta to the epsilon. + + align:start position:0% +sharp up to the delta to the epsilon. + + + align:start position:0% +sharp up to the delta to the epsilon. +In future I'm going to abbreviate that + + align:start position:0% +In future I'm going to abbreviate that + + + align:start position:0% +In future I'm going to abbreviate that +mess by this. we won't be at the level + + align:start position:0% +mess by this. we won't be at the level + + + align:start position:0% +mess by this. we won't be at the level +of detail to have all of this in. + + align:start position:0% + + + + align:start position:0% + +Okay. So, um so this this the story I + + align:start position:0% +Okay. So, um so this this the story I + + + align:start position:0% +Okay. So, um so this this the story I +wanted to try to tell to explore over + + align:start position:0% +wanted to try to tell to explore over + + + align:start position:0% +wanted to try to tell to explore over +the last three classes is how is it + + align:start position:0% +the last three classes is how is it + + + align:start position:0% +the last three classes is how is it +possible to get from these epsilon + + align:start position:0% +possible to get from these epsilon + + + align:start position:0% +possible to get from these epsilon +improvements to sharp theorems. That's + + align:start position:0% +improvements to sharp theorems. That's + + + align:start position:0% +improvements to sharp theorems. That's +that's our our theme for the rest of the + + align:start position:0% +that's our our theme for the rest of the + + + align:start position:0% +that's our our theme for the rest of the +class. Um, and if I had to say it in a + + align:start position:0% +class. Um, and if I had to say it in a + + + align:start position:0% +class. Um, and if I had to say it in a +couple of sentences, + + align:start position:0% +couple of sentences, + + + align:start position:0% +couple of sentences, +what happened was people found a way + + align:start position:0% +what happened was people found a way + + + align:start position:0% +what happened was people found a way +where you can use an epsilon improvement + + align:start position:0% +where you can use an epsilon improvement + + + align:start position:0% +where you can use an epsilon improvement +theorem and you can use it over and over + + align:start position:0% +theorem and you can use it over and over + + + align:start position:0% +theorem and you can use it over and over +again and sort of each time you use it, + + align:start position:0% +again and sort of each time you use it, + + + align:start position:0% +again and sort of each time you use it, +you improve a little bit the exponent in + + align:start position:0% +you improve a little bit the exponent in + + + align:start position:0% +you improve a little bit the exponent in +your bound until you bring the exponent + + align:start position:0% +your bound until you bring the exponent + + + align:start position:0% +your bound until you bring the exponent +up to the sharp value. + + align:start position:0% +up to the sharp value. + + + align:start position:0% +up to the sharp value. +Okay? Now, it's not at all obvious how + + align:start position:0% +Okay? Now, it's not at all obvious how + + + align:start position:0% +Okay? Now, it's not at all obvious how +to do that, and that's what we're we're + + align:start position:0% +to do that, and that's what we're we're + + + align:start position:0% +to do that, and that's what we're we're +going to try to explain. uh um not with + + align:start position:0% +going to try to explain. uh um not with + + + align:start position:0% +going to try to explain. uh um not with +all details but to to make it seem like + + align:start position:0% +all details but to to make it seem like + + + align:start position:0% +all details but to to make it seem like +a plausible approach that you could that + + align:start position:0% +a plausible approach that you could that + + + align:start position:0% +a plausible approach that you could that +you could carry. + + align:start position:0% +you could carry. + + + align:start position:0% +you could carry. +Cool. Okay. So any questions or comments + + align:start position:0% +Cool. Okay. So any questions or comments + + + align:start position:0% +Cool. Okay. So any questions or comments +before we start? Yeah. + + align:start position:0% +before we start? Yeah. + + + align:start position:0% +before we start? Yeah. +>> Does doing that process make the like C + + align:start position:0% +>> Does doing that process make the like C + + + align:start position:0% +>> Does doing that process make the like C +to the O one constant kind of + + align:start position:0% +to the O one constant kind of + + + align:start position:0% +to the O one constant kind of +corresponding way I guess tiny compared + + align:start position:0% +corresponding way I guess tiny compared + + + align:start position:0% +corresponding way I guess tiny compared +to the epsilon constant? + + align:start position:0% +to the epsilon constant? + + + align:start position:0% +to the epsilon constant? +>> Um yeah. So I think the question is as + + align:start position:0% +>> Um yeah. So I think the question is as + + + align:start position:0% +>> Um yeah. So I think the question is as +as we as we use our epsilon improvement + + align:start position:0% +as we as we use our epsilon improvement + + + align:start position:0% +as we as we use our epsilon improvement +theorem many times does that cause this + + align:start position:0% +theorem many times does that cause this + + + align:start position:0% +theorem many times does that cause this +to become remarkably bad? + + align:start position:0% +to become remarkably bad? + + + align:start position:0% +to become remarkably bad? +I think it does. Okay. I think that this + + align:start position:0% +I think it does. Okay. I think that this + + + align:start position:0% +I think it does. Okay. I think that this +is remarkably bad. + + align:start position:0% +is remarkably bad. + + + align:start position:0% +is remarkably bad. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Okay. Great. So today I my first goal is + + align:start position:0% +Okay. Great. So today I my first goal is + + + align:start position:0% +Okay. Great. So today I my first goal is +I want to describe the simplest example + + align:start position:0% +I want to describe the simplest example + + + align:start position:0% +I want to describe the simplest example +where you can get where you can use an + + align:start position:0% +where you can get where you can use an + + + align:start position:0% +where you can get where you can use an +epsilon improvement theorem to prove a + + align:start position:0% +epsilon improvement theorem to prove a + + + align:start position:0% +epsilon improvement theorem to prove a +sharp theorem. + + align:start position:0% +sharp theorem. + + + align:start position:0% +sharp theorem. +And then after that if we have time I + + align:start position:0% +And then after that if we have time I + + + align:start position:0% +And then after that if we have time I +will outline the proof of the big thing. + + align:start position:0% +will outline the proof of the big thing. + + + align:start position:0% +will outline the proof of the big thing. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +[Applause] + + align:start position:0% + + + + align:start position:0% + +Okay. So, simplest + + align:start position:0% +Okay. So, simplest + + + align:start position:0% +Okay. So, simplest +example + + align:start position:0% + + + + align:start position:0% + +where + + align:start position:0% +where + + + align:start position:0% +where +epsilon improvement + + align:start position:0% + + + + align:start position:0% + +leads to sharp out. + + align:start position:0% + + + + align:start position:0% + +Okay, so this is a theorem of Beck from + + align:start position:0% +Okay, so this is a theorem of Beck from + + + align:start position:0% +Okay, so this is a theorem of Beck from +around 1980 + + align:start position:0% +around 1980 + + + align:start position:0% +around 1980 +which is about the incidences of points + + align:start position:0% +which is about the incidences of points + + + align:start position:0% +which is about the incidences of points +and lines. So it's in the setting of the + + align:start position:0% +and lines. So it's in the setting of the + + + align:start position:0% +and lines. So it's in the setting of the +summary troder theorem. + + align:start position:0% +summary troder theorem. + + + align:start position:0% +summary troder theorem. +It says if E is a subset of R2 and it's + + align:start position:0% +It says if E is a subset of R2 and it's + + + align:start position:0% +It says if E is a subset of R2 and it's +not all on a line and in fact I'll say + + align:start position:0% +not all on a line and in fact I'll say + + + align:start position:0% +not all on a line and in fact I'll say +at most half of it is on a line. So for + + align:start position:0% +at most half of it is on a line. So for + + + align:start position:0% +at most half of it is on a line. So for +any line L + + align:start position:0% +any line L + + + align:start position:0% +any line L +L intersect E is at most half of it. + + align:start position:0% +L intersect E is at most half of it. + + + align:start position:0% +L intersect E is at most half of it. +Then the conclusion is there exists some + + align:start position:0% +Then the conclusion is there exists some + + + align:start position:0% +Then the conclusion is there exists some +point X in E. So that uh all right so + + align:start position:0% +point X in E. So that uh all right so + + + align:start position:0% +point X in E. So that uh all right so +let me make a definition. So I I'll draw + + align:start position:0% +let me make a definition. So I I'll draw + + + align:start position:0% +let me make a definition. So I I'll draw +a picture. So this is E. + + align:start position:0% + + + + align:start position:0% + +Here's our set E. Here's a point X. + + align:start position:0% +Here's our set E. Here's a point X. + + + align:start position:0% +Here's our set E. Here's a point X. +Starting at X, I will draw all the lines + + align:start position:0% +Starting at X, I will draw all the lines + + + align:start position:0% +Starting at X, I will draw all the lines +that start at X and go through some + + align:start position:0% +that start at X and go through some + + + align:start position:0% +that start at X and go through some +other points at E. + + align:start position:0% + + + + align:start position:0% + +Okay. So what's that set? So I'll call + + align:start position:0% +Okay. So what's that set? So I'll call + + + align:start position:0% +Okay. So what's that set? So I'll call +it L XE. This is the set of lines. So + + align:start position:0% +it L XE. This is the set of lines. So + + + align:start position:0% +it L XE. This is the set of lines. So +that lines L. So that X is in L and L + + align:start position:0% +that lines L. So that X is in L and L + + + align:start position:0% +that lines L. So that X is in L and L +intersect E is not just X. So it has + + align:start position:0% +intersect E is not just X. So it has + + + align:start position:0% +intersect E is not just X. So it has +size at least two. + + align:start position:0% + + + + align:start position:0% + +Now the conclusion is there is a point + + align:start position:0% +Now the conclusion is there is a point + + + align:start position:0% +Now the conclusion is there is a point +in E so that the size of LXE is + + align:start position:0% +in E so that the size of LXE is + + + align:start position:0% +in E so that the size of LXE is +comparable to the size of E. + + align:start position:0% + + + + align:start position:0% + +This is clearly a sharp theorem because + + align:start position:0% +This is clearly a sharp theorem because + + + align:start position:0% +This is clearly a sharp theorem because +the largest possible size that this + + align:start position:0% +the largest possible size that this + + + align:start position:0% +the largest possible size that this +could be is the size of + + align:start position:0% +could be is the size of + + + align:start position:0% +could be is the size of +all right. Um let me do a proof sketch. + + align:start position:0% + + + + align:start position:0% + +Um and we'll so we'll see that this + + align:start position:0% +Um and we'll so we'll see that this + + + align:start position:0% +Um and we'll so we'll see that this +follows from sem ready troder. Um but + + align:start position:0% +follows from sem ready troder. Um but + + + align:start position:0% +follows from sem ready troder. Um but +we'll also see that we don't really need + + align:start position:0% +we'll also see that we don't really need + + + align:start position:0% +we'll also see that we don't really need +the sharp exponents in semi troder. We + + align:start position:0% +the sharp exponents in semi troder. We + + + align:start position:0% +the sharp exponents in semi troder. We +just need to have something that's an + + align:start position:0% +just need to have something that's an + + + align:start position:0% +just need to have something that's an +epsilon better than um uh than a than a + + align:start position:0% +epsilon better than um uh than a than a + + + align:start position:0% +epsilon better than um uh than a than a +simple bound. That's why I've erased it + + align:start position:0% +simple bound. That's why I've erased it + + + align:start position:0% +simple bound. That's why I've erased it +but than the double counting kind of + + align:start position:0% +but than the double counting kind of + + + align:start position:0% +but than the double counting kind of +bound. + + align:start position:0% +bound. + + + align:start position:0% +bound. +Okay. So here we go. So the sketchy part + + align:start position:0% +Okay. So here we go. So the sketchy part + + + align:start position:0% +Okay. So here we go. So the sketchy part +of my proof sketch is that I will + + align:start position:0% +of my proof sketch is that I will + + + align:start position:0% +of my proof sketch is that I will +suppose that we are in the uniform case. + + align:start position:0% +suppose that we are in the uniform case. + + + align:start position:0% +suppose that we are in the uniform case. +Namely for every x in E, I will suppose + + align:start position:0% +Namely for every x in E, I will suppose + + + align:start position:0% +Namely for every x in E, I will suppose +that lx of E has size around S. + + align:start position:0% +that lx of E has size around S. + + + align:start position:0% +that lx of E has size around S. +So it's not really the case that they + + align:start position:0% +So it's not really the case that they + + + align:start position:0% +So it's not really the case that they +would all be comparable, but I'll just + + align:start position:0% +would all be comparable, but I'll just + + + align:start position:0% +would all be comparable, but I'll just +explain that special case. + + align:start position:0% +explain that special case. + + + align:start position:0% +explain that special case. +Okay. So now um how many lines are there + + align:start position:0% +Okay. So now um how many lines are there + + + align:start position:0% +Okay. So now um how many lines are there +in total? We can do a double count to + + align:start position:0% +in total? We can do a double count to + + + align:start position:0% +in total? We can do a double count to +find the total number of lines. So we're + + align:start position:0% +find the total number of lines. So we're + + + align:start position:0% +find the total number of lines. So we're +going to double count pairs um x l where + + align:start position:0% +going to double count pairs um x l where + + + align:start position:0% +going to double count pairs um x l where +x is in uh e + + align:start position:0% +x is in uh e + + + align:start position:0% +x is in uh e +and l is in our set of lines. + + align:start position:0% +and l is in our set of lines. + + + align:start position:0% +and l is in our set of lines. +So our total set of lines is going to be + + align:start position:0% + + + + align:start position:0% + +let's do this. + + align:start position:0% + + + + align:start position:0% + +Okay. So how big is le? Um well we could + + align:start position:0% +Okay. So how big is le? Um well we could + + + align:start position:0% +Okay. So how big is le? Um well we could +count the number of these pairs in two + + align:start position:0% +count the number of these pairs in two + + + align:start position:0% +count the number of these pairs in two +ways. We could count okay look at all + + align:start position:0% +ways. We could count okay look at all + + + align:start position:0% +ways. We could count okay look at all +the points of E and each of them is in S + + align:start position:0% +the points of E and each of them is in S + + + align:start position:0% +the points of E and each of them is in S +lines + + align:start position:0% +lines + + + align:start position:0% +lines +or we could say look at each of these + + align:start position:0% +or we could say look at each of these + + + align:start position:0% +or we could say look at each of these +lines + + align:start position:0% +lines + + + align:start position:0% +lines +and um how many points are in each line? + + align:start position:0% +and um how many points are in each line? + + + align:start position:0% +and um how many points are in each line? +Well, + + align:start position:0% +Well, + + + align:start position:0% +Well, +the number of the size of + + align:start position:0% +the number of the size of + + + align:start position:0% +the number of the size of +uh S the size of E intersect L + + align:start position:0% +uh S the size of E intersect L + + + align:start position:0% +uh S the size of E intersect L +for a typical L and L XE would be the + + align:start position:0% +for a typical L and L XE would be the + + + align:start position:0% +for a typical L and L XE would be the +size of E divided by the size of L XE. + + align:start position:0% +size of E divided by the size of L XE. + + + align:start position:0% +size of E divided by the size of L XE. +Right? Because I have all the points in + + align:start position:0% +Right? Because I have all the points in + + + align:start position:0% +Right? Because I have all the points in +E. They are divided among the lines of + + align:start position:0% +E. They are divided among the lines of + + + align:start position:0% +E. They are divided among the lines of +LXE. Again, assuming it's uniform, they + + align:start position:0% +LXE. Again, assuming it's uniform, they + + + align:start position:0% +LXE. Again, assuming it's uniform, they +would all have around this size. + + align:start position:0% + + + + align:start position:0% + +E over L XC + + align:start position:0% +E over L XC + + + align:start position:0% +E over L XC +which is S. + + align:start position:0% + + + + align:start position:0% + +Okay. So this is the number of points + + align:start position:0% +Okay. So this is the number of points + + + align:start position:0% +Okay. So this is the number of points +times they're each in S lines versus the + + align:start position:0% +times they're each in S lines versus the + + + align:start position:0% +times they're each in S lines versus the +number of lines times they each have + + align:start position:0% +number of lines times they each have + + + align:start position:0% +number of lines times they each have +this many points. + + align:start position:0% +this many points. + + + align:start position:0% +this many points. +Okay. So when we solve we see that the E + + align:start position:0% +Okay. So when we solve we see that the E + + + align:start position:0% +Okay. So when we solve we see that the E +actually drops out and we conclude that + + align:start position:0% +actually drops out and we conclude that + + + align:start position:0% +actually drops out and we conclude that +LE is around S squ. + + align:start position:0% + + + + align:start position:0% + +Okay. So um our goal is to have a lower + + align:start position:0% +Okay. So um our goal is to have a lower + + + align:start position:0% +Okay. So um our goal is to have a lower +bound on on S. So we want to have a + + align:start position:0% +bound on on S. So we want to have a + + + align:start position:0% +bound on on S. So we want to have a +lower bound on LE and the semi trder + + align:start position:0% +lower bound on LE and the semi trder + + + align:start position:0% +lower bound on LE and the semi trder +theorem exactly gives us a lower bound + + align:start position:0% +theorem exactly gives us a lower bound + + + align:start position:0% +theorem exactly gives us a lower bound +on LE. So we can use it. So the semi + + align:start position:0% +on LE. So we can use it. So the semi + + + align:start position:0% +on LE. So we can use it. So the semi +trider theorem tells us that L + + align:start position:0% +trider theorem tells us that L + + + align:start position:0% +trider theorem tells us that L +is at least the minimum of S * E and S + + align:start position:0% +is at least the minimum of S * E and S + + + align:start position:0% +is at least the minimum of S * E and S +to the three * E to the 12. Okay, but + + align:start position:0% +to the three * E to the 12. Okay, but + + + align:start position:0% +to the three * E to the 12. Okay, but +this L E is is S squ. So if you compare + + align:start position:0% +this L E is is S squ. So if you compare + + + align:start position:0% +this L E is is S squ. So if you compare +these we can get a lower bound for S. + + align:start position:0% +these we can get a lower bound for S. + + + align:start position:0% +these we can get a lower bound for S. +In in this case we would have S^ squ is + + align:start position:0% +In in this case we would have S^ squ is + + + align:start position:0% +In in this case we would have S^ squ is +bigger than SE. So s is bigger than e + + align:start position:0% +bigger than SE. So s is bigger than e + + + align:start position:0% +bigger than SE. So s is bigger than e +and in this case we would have s^ squ is + + align:start position:0% +and in this case we would have s^ squ is + + + align:start position:0% +and in this case we would have s^ squ is +bigger than s^ 3 e to the 12 and with a + + align:start position:0% +bigger than s^ 3 e to the 12 and with a + + + align:start position:0% +bigger than s^ 3 e to the 12 and with a +little algebra that is again s bigger + + align:start position:0% +little algebra that is again s bigger + + + align:start position:0% +little algebra that is again s bigger +than e. + + align:start position:0% +than e. + + + align:start position:0% +than e. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Um so + + align:start position:0% +Um so + + + align:start position:0% +Um so +right. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Right. + + align:start position:0% +Right. + + + align:start position:0% +Right. +Now, + + align:start position:0% + + + + align:start position:0% + +now I claim that we didn't need to have + + align:start position:0% +now I claim that we didn't need to have + + + align:start position:0% +now I claim that we didn't need to have +this exact formula here. Let me write + + align:start position:0% +this exact formula here. Let me write + + + align:start position:0% +this exact formula here. Let me write +down all that we needed to to know. + + align:start position:0% +down all that we needed to to know. + + + align:start position:0% +down all that we needed to to know. +So what we needed to know + + align:start position:0% + + + + align:start position:0% + +is just that if E is much bigger than S + + align:start position:0% +is just that if E is much bigger than S + + + align:start position:0% +is just that if E is much bigger than S +um then the size of L E is much bigger + + align:start position:0% +um then the size of L E is much bigger + + + align:start position:0% +um then the size of L E is much bigger +than S squ. + + align:start position:0% + + + + align:start position:0% + +So that's a feature you can read off of + + align:start position:0% +So that's a feature you can read off of + + + align:start position:0% +So that's a feature you can read off of +this formula. If E is much bigger than + + align:start position:0% +this formula. If E is much bigger than + + + align:start position:0% +this formula. If E is much bigger than +S, then either one of these is much + + align:start position:0% +S, then either one of these is much + + + align:start position:0% +S, then either one of these is much +bigger than S^ squ. And that's all we + + align:start position:0% +bigger than S^ squ. And that's all we + + + align:start position:0% +bigger than S^ squ. And that's all we +needed to know because we know that L E + + align:start position:0% +needed to know because we know that L E + + + align:start position:0% +needed to know because we know that L E +is only S squ. So by the contraositive + + align:start position:0% +is only S squ. So by the contraositive + + + align:start position:0% +is only S squ. So by the contraositive +we could see that E + + align:start position:0% +we could see that E + + + align:start position:0% +we could see that E +S is not much smaller than E S should be + + align:start position:0% +S is not much smaller than E S should be + + + align:start position:0% +S is not much smaller than E S should be +at least around E. + + align:start position:0% +at least around E. + + + align:start position:0% +at least around E. +Okay. So this thing that we needed to + + align:start position:0% +Okay. So this thing that we needed to + + + align:start position:0% +Okay. So this thing that we needed to +know + + align:start position:0% +know + + + align:start position:0% +know +is very similar to the Orpin and + + align:start position:0% +is very similar to the Orpin and + + + align:start position:0% +is very similar to the Orpin and +Schmurkin theorem. + + align:start position:0% + + + + align:start position:0% + +E is much bigger. So now let's look up + + align:start position:0% +E is much bigger. So now let's look up + + + align:start position:0% +E is much bigger. So now let's look up +at that Orpin and Schmurkin theorem says + + align:start position:0% +at that Orpin and Schmurkin theorem says + + + align:start position:0% +at that Orpin and Schmurkin theorem says +if T is bigger than S just bigger than + + align:start position:0% +if T is bigger than S just bigger than + + + align:start position:0% +if T is bigger than S just bigger than +zero. + + align:start position:0% +zero. + + + align:start position:0% +zero. +So T is measuring the size of our set E + + align:start position:0% +So T is measuring the size of our set E + + + align:start position:0% +So T is measuring the size of our set E +and little S corresponds to big S. + + align:start position:0% +and little S corresponds to big S. + + + align:start position:0% +and little S corresponds to big S. +So that first hypothesis is saying that + + align:start position:0% +So that first hypothesis is saying that + + + align:start position:0% +So that first hypothesis is saying that +the set is much bigger than the number + + align:start position:0% +the set is much bigger than the number + + + align:start position:0% +the set is much bigger than the number +of directions. + + align:start position:0% +of directions. + + + align:start position:0% +of directions. +And then the conclusion is that the + + align:start position:0% +And then the conclusion is that the + + + align:start position:0% +And then the conclusion is that the +number of lines is much bigger than S^ + + align:start position:0% +number of lines is much bigger than S^ + + + align:start position:0% +number of lines is much bigger than S^ +squ. that thing is this. + + align:start position:0% + + + + align:start position:0% + +Okay. So this matches + + align:start position:0% +Okay. So this matches + + + align:start position:0% +Okay. So this matches +the theorem of Orpin and Schmurkin the + + align:start position:0% +the theorem of Orpin and Schmurkin the + + + align:start position:0% +the theorem of Orpin and Schmurkin the +epsilon improvement theorem. + + align:start position:0% + + + + align:start position:0% + +Okay. So that suggests an idea that we + + align:start position:0% +Okay. So that suggests an idea that we + + + align:start position:0% +Okay. So that suggests an idea that we +could use that epsilon improvement + + align:start position:0% +could use that epsilon improvement + + + align:start position:0% +could use that epsilon improvement +theorem by Orpin and Schmurkin and put + + align:start position:0% +theorem by Orpin and Schmurkin and put + + + align:start position:0% +theorem by Orpin and Schmurkin and put +it into an argument like this one and + + align:start position:0% +it into an argument like this one and + + + align:start position:0% +it into an argument like this one and +prove some kind of generalization of + + align:start position:0% +prove some kind of generalization of + + + align:start position:0% +prove some kind of generalization of +Beck's theorem that might have a sharp + + align:start position:0% +Beck's theorem that might have a sharp + + + align:start position:0% +Beck's theorem that might have a sharp +conclusion even though we stuck into it + + align:start position:0% +conclusion even though we stuck into it + + + align:start position:0% +conclusion even though we stuck into it +just a epsilon improvement + + align:start position:0% +just a epsilon improvement + + + align:start position:0% +just a epsilon improvement +and that actually works. So I'm going to + + align:start position:0% +and that actually works. So I'm going to + + + align:start position:0% +and that actually works. So I'm going to +write it down now for us. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So this is called the continuum + + align:start position:0% +So this is called the continuum + + + align:start position:0% +So this is called the continuum +or we could call it in our class the + + align:start position:0% +or we could call it in our class the + + + align:start position:0% +or we could call it in our class the +delta ball version of back theory. + + align:start position:0% + + + + align:start position:0% + +Okay. So this is a theorem of merkin and + + align:start position:0% +Okay. So this is a theorem of merkin and + + + align:start position:0% +Okay. So this is a theorem of merkin and +wong in 23 I think. + + align:start position:0% +wong in 23 I think. + + + align:start position:0% +wong in 23 I think. +All right. So we're going to translate + + align:start position:0% +All right. So we're going to translate + + + align:start position:0% +All right. So we're going to translate +this theorem into the language of delta + + align:start position:0% +this theorem into the language of delta + + + align:start position:0% +this theorem into the language of delta +SC sets. + + align:start position:0% +SC sets. + + + align:start position:0% +SC sets. +So we're going to say if E is a deltaU + + align:start position:0% +So we're going to say if E is a deltaU + + + align:start position:0% +So we're going to say if E is a deltaU +set, I'm going to leave out the C. Uh + + align:start position:0% +set, I'm going to leave out the C. Uh + + + align:start position:0% +set, I'm going to leave out the C. Uh +things will depend on C, but E is a + + align:start position:0% +things will depend on C, but E is a + + + align:start position:0% +things will depend on C, but E is a +deltaU set. Okay, so that's our set. Now + + align:start position:0% +deltaU set. Okay, so that's our set. Now + + + align:start position:0% +deltaU set. Okay, so that's our set. Now +I need an analog of this hypothesis that + + align:start position:0% +I need an analog of this hypothesis that + + + align:start position:0% +I need an analog of this hypothesis that +E is not too much in the line. And the + + align:start position:0% +E is not too much in the line. And the + + + align:start position:0% +E is not too much in the line. And the +analog says that E will be not too much + + align:start position:0% +analog says that E will be not too much + + + align:start position:0% +analog says that E will be not too much +in any thin rectangle. + + align:start position:0% +in any thin rectangle. + + + align:start position:0% +in any thin rectangle. +So we'll say if R is a row by one + + align:start position:0% +So we'll say if R is a row by one + + + align:start position:0% +So we'll say if R is a row by one +rectangle + + align:start position:0% +rectangle + + + align:start position:0% +rectangle +um then + + align:start position:0% +um then + + + align:start position:0% +um then +if you take E and you intersect it with + + align:start position:0% +if you take E and you intersect it with + + + align:start position:0% +if you take E and you intersect it with +R take the delta covering number of that + + align:start position:0% + + + + align:start position:0% + +should be kind of smaller than the total + + align:start position:0% +should be kind of smaller than the total + + + align:start position:0% +should be kind of smaller than the total +delta covering number. + + align:start position:0% +delta covering number. + + + align:start position:0% +delta covering number. +Okay so it should be row to the ADA + + align:start position:0% +Okay so it should be row to the ADA + + + align:start position:0% +Okay so it should be row to the ADA +smaller than constant row to the ADA is + + align:start position:0% +smaller than constant row to the ADA is + + + align:start position:0% +smaller than constant row to the ADA is +smaller than the total delta covering + + align:start position:0% +smaller than the total delta covering + + + align:start position:0% +smaller than the total delta covering +number. Maybe we can we can put the C + + align:start position:0% +number. Maybe we can we can put the C + + + align:start position:0% +number. Maybe we can we can put the C +back here also. So who is ADA? At the + + align:start position:0% +back here also. So who is ADA? At the + + + align:start position:0% +back here also. So who is ADA? At the +very beginning of the story, we'll say + + align:start position:0% +very beginning of the story, we'll say + + + align:start position:0% +very beginning of the story, we'll say +for every + + align:start position:0% +for every + + + align:start position:0% +for every +ADA bigger than zero. So ADA should be a + + align:start position:0% +ADA bigger than zero. So ADA should be a + + + align:start position:0% +ADA bigger than zero. So ADA should be a +positive number. Okay. So this is a not + + align:start position:0% +positive number. Okay. So this is a not + + + align:start position:0% +positive number. Okay. So this is a not +super strong condition, but it's saying + + align:start position:0% +super strong condition, but it's saying + + + align:start position:0% +super strong condition, but it's saying +that E is not heavily concentrated into + + align:start position:0% +that E is not heavily concentrated into + + + align:start position:0% +that E is not heavily concentrated into +a thin rectangle. + + align:start position:0% +a thin rectangle. + + + align:start position:0% +a thin rectangle. +Okay. And then the conclusion is um + + align:start position:0% +Okay. And then the conclusion is um + + + align:start position:0% +Okay. And then the conclusion is um +there exists an x in e s so that + + align:start position:0% +there exists an x in e s so that + + + align:start position:0% +there exists an x in e s so that +um the size of lxe + + align:start position:0% +um the size of lxe + + + align:start position:0% +um the size of lxe +is greater than um + + align:start position:0% +is greater than um + + + align:start position:0% +is greater than um +uh the minimum + + align:start position:0% +uh the minimum + + + align:start position:0% +uh the minimum +of delta to the minus u and one. So this + + align:start position:0% +of delta to the minus u and one. So this + + + align:start position:0% +of delta to the minus u and one. So this +would be and sorry not one delta to the + + align:start position:0% +would be and sorry not one delta to the + + + align:start position:0% +would be and sorry not one delta to the +minus one. + + align:start position:0% +minus one. + + + align:start position:0% +minus one. +Okay. So what's going on here? The our + + align:start position:0% +Okay. So what's going on here? The our + + + align:start position:0% +Okay. So what's going on here? The our +original theorem would say that lxe e is + + align:start position:0% +original theorem would say that lxe e is + + + align:start position:0% +original theorem would say that lxe e is +at least the size of e and that's the + + align:start position:0% +at least the size of e and that's the + + + align:start position:0% +at least the size of e and that's the +size of so that's what it's doing here. + + align:start position:0% +size of so that's what it's doing here. + + + align:start position:0% +size of so that's what it's doing here. +On the other hand if I had every delta + + align:start position:0% +On the other hand if I had every delta + + + align:start position:0% +On the other hand if I had every delta +tube if lxe consisted of all the delta + + align:start position:0% +tube if lxe consisted of all the delta + + + align:start position:0% +tube if lxe consisted of all the delta +tubes through x there would only be + + align:start position:0% +tubes through x there would only be + + + align:start position:0% +tubes through x there would only be +delta inverse of them. So it couldn't + + align:start position:0% +delta inverse of them. So it couldn't + + + align:start position:0% +delta inverse of them. So it couldn't +possibly be bigger than this. So we have + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Um cool. So that's the statement of the + + align:start position:0% +Um cool. So that's the statement of the + + + align:start position:0% +Um cool. So that's the statement of the +theorem and it is again uh sharp because + + align:start position:0% +theorem and it is again uh sharp because + + + align:start position:0% +theorem and it is again uh sharp because +as we just explained this couldn't + + align:start position:0% +as we just explained this couldn't + + + align:start position:0% +as we just explained this couldn't +possibly be bigger than this and it also + + align:start position:0% +possibly be bigger than this and it also + + + align:start position:0% +possibly be bigger than this and it also +couldn't possibly be bigger than this. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Um + + align:start position:0% + + + + align:start position:0% + +correct. + + align:start position:0% +correct. + + + align:start position:0% +correct. +So this theorem is sharp. It's also + + align:start position:0% +So this theorem is sharp. It's also + + + align:start position:0% +So this theorem is sharp. It's also +false over C. + + align:start position:0% + + + + align:start position:0% + +Right? So the example over C would be + + align:start position:0% +Right? So the example over C would be + + + align:start position:0% +Right? So the example over C would be +that the set E + + align:start position:0% +that the set E + + + align:start position:0% +that the set E +could be uh R2 which is sitting in C2. + + align:start position:0% +could be uh R2 which is sitting in C2. + + + align:start position:0% +could be uh R2 which is sitting in C2. +And if you imagine R2, if you take any + + align:start position:0% +And if you imagine R2, if you take any + + + align:start position:0% +And if you imagine R2, if you take any +point in R2 and look at all of the + + align:start position:0% +point in R2 and look at all of the + + + align:start position:0% +point in R2 and look at all of the +lines, complex lines that um go through + + align:start position:0% +lines, complex lines that um go through + + + align:start position:0% +lines, complex lines that um go through +that point, um there aren't the the each + + align:start position:0% +that point, um there aren't the the each + + + align:start position:0% +that point, um there aren't the the each +one of them goes through many of the + + align:start position:0% +one of them goes through many of the + + + align:start position:0% +one of them goes through many of the +points of R2 and um and the number there + + align:start position:0% +points of R2 and um and the number there + + + align:start position:0% +points of R2 and um and the number there +aren't that many of them. It would + + align:start position:0% +aren't that many of them. It would + + + align:start position:0% +aren't that many of them. It would +violate this. + + align:start position:0% + + + + align:start position:0% + +Okay, so this theorem is uh in the + + align:start position:0% +Okay, so this theorem is uh in the + + + align:start position:0% +Okay, so this theorem is uh in the +general spirit of projection theory. um + + align:start position:0% +general spirit of projection theory. um + + + align:start position:0% +general spirit of projection theory. um +it is a sharp theorem and it + + align:start position:0% +it is a sharp theorem and it + + + align:start position:0% +it is a sharp theorem and it +distinguishes R from C and I believe it + + align:start position:0% +distinguishes R from C and I believe it + + + align:start position:0% +distinguishes R from C and I believe it +is the first such theorem in the + + align:start position:0% +is the first such theorem in the + + + align:start position:0% +is the first such theorem in the +literature. So we were trying for 20 + + align:start position:0% +literature. So we were trying for 20 + + + align:start position:0% +literature. So we were trying for 20 +plus years to distinguish R from C. For + + align:start position:0% +plus years to distinguish R from C. For + + + align:start position:0% +plus years to distinguish R from C. For +a long time we could only do it with + + align:start position:0% +a long time we could only do it with + + + align:start position:0% +a long time we could only do it with +epsilon improvements. But this is not + + align:start position:0% +epsilon improvements. But this is not + + + align:start position:0% +epsilon improvements. But this is not +just an epsilon improvement on what was + + align:start position:0% +just an epsilon improvement on what was + + + align:start position:0% +just an epsilon improvement on what was +known before. It's not just an epsilon + + align:start position:0% +known before. It's not just an epsilon + + + align:start position:0% +known before. It's not just an epsilon +improvement on what's true over over C. + + align:start position:0% +improvement on what's true over over C. + + + align:start position:0% +improvement on what's true over over C. +And it's a sharp theorem. + + align:start position:0% +And it's a sharp theorem. + + + align:start position:0% +And it's a sharp theorem. +Okay. Any questions or comments about + + align:start position:0% +Okay. Any questions or comments about + + + align:start position:0% +Okay. Any questions or comments about +the statement? + + align:start position:0% +the statement? + + + align:start position:0% +the statement? +So the problem depends on + + align:start position:0% +So the problem depends on + + + align:start position:0% +So the problem depends on +>> yeah so if you unpack this it must + + align:start position:0% +>> yeah so if you unpack this it must + + + align:start position:0% +>> yeah so if you unpack this it must +depend on ADA. Uh I think it is a + + align:start position:0% +depend on ADA. Uh I think it is a + + + align:start position:0% +depend on ADA. Uh I think it is a +constant depending on epsilon and ada + + align:start position:0% +constant depending on epsilon and ada + + + align:start position:0% +constant depending on epsilon and ada +delta to the epsilon and big c to the + + align:start position:0% +delta to the epsilon and big c to the + + + align:start position:0% +delta to the epsilon and big c to the +minus big. + + align:start position:0% +minus big. + + + align:start position:0% +minus big. +So it depends on it depends on aa + + align:start position:0% + + + + align:start position:0% + +it's conceivable that this depends on + + align:start position:0% +it's conceivable that this depends on + + + align:start position:0% +it's conceivable that this depends on +ada. I'm not sure about that. + + align:start position:0% + + + + align:start position:0% + +Other questions or comments? + + align:start position:0% + + + + align:start position:0% + +Okay. Okay. So the the idea in the first + + align:start position:0% +Okay. Okay. So the the idea in the first + + + align:start position:0% +Okay. Okay. So the the idea in the first +place is to imitate this proof of Beex + + align:start position:0% +place is to imitate this proof of Beex + + + align:start position:0% +place is to imitate this proof of Beex +theorem proof that converts um a uh + + align:start position:0% +theorem proof that converts um a uh + + + align:start position:0% +theorem proof that converts um a uh +a an epsilon improvement on some simple + + align:start position:0% +a an epsilon improvement on some simple + + + align:start position:0% +a an epsilon improvement on some simple +estimate for sem ready troder into a + + align:start position:0% +estimate for sem ready troder into a + + + align:start position:0% +estimate for sem ready troder into a +sharp estimate for this beck kind of + + align:start position:0% +sharp estimate for this beck kind of + + + align:start position:0% +sharp estimate for this beck kind of +thing. Um but when we try to do that we + + align:start position:0% +thing. Um but when we try to do that we + + + align:start position:0% +thing. Um but when we try to do that we +will see that there is an issue with it. + + align:start position:0% +will see that there is an issue with it. + + + align:start position:0% +will see that there is an issue with it. +Um and and when we flesh out the proof a + + align:start position:0% +Um and and when we flesh out the proof a + + + align:start position:0% +Um and and when we flesh out the proof a +little more, it will involve using the + + align:start position:0% +little more, it will involve using the + + + align:start position:0% +little more, it will involve using the +Orpin and Schmurkin theorem not just + + align:start position:0% +Orpin and Schmurkin theorem not just + + + align:start position:0% +Orpin and Schmurkin theorem not just +once but many times at many different + + align:start position:0% +once but many times at many different + + + align:start position:0% +once but many times at many different +scales. + + align:start position:0% + + + + align:start position:0% + +All right. So let's sketch the proof. + + align:start position:0% + + + + align:start position:0% + +So first plan + + align:start position:0% + + + + align:start position:0% + +is to imitate + + align:start position:0% +is to imitate + + + align:start position:0% +is to imitate +the proof of uh of Beck. + + align:start position:0% +the proof of uh of Beck. + + + align:start position:0% +the proof of uh of Beck. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Um okay. So let's carry that out over + + align:start position:0% +Um okay. So let's carry that out over + + + align:start position:0% +Um okay. So let's carry that out over +here. I'll put the beex proof up. + + align:start position:0% +here. I'll put the beex proof up. + + + align:start position:0% +here. I'll put the beex proof up. +[Applause] + + align:start position:0% + + + + align:start position:0% + +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +So attempt attempt one. + + align:start position:0% +So attempt attempt one. + + + align:start position:0% +So attempt attempt one. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +All right. So let's say that lxe + + align:start position:0% +All right. So let's say that lxe + + + align:start position:0% +All right. So let's say that lxe +is a delta SC + + align:start position:0% +is a delta SC + + + align:start position:0% +is a delta SC +set. + + align:start position:0% + + + + align:start position:0% + +Now that's related to the cardality of + + align:start position:0% +Now that's related to the cardality of + + + align:start position:0% +Now that's related to the cardality of +LXE. This is a theorem about the + + align:start position:0% +LXE. This is a theorem about the + + + align:start position:0% +LXE. This is a theorem about the +cardality of LXE. What is the + + align:start position:0% +cardality of LXE. What is the + + + align:start position:0% +cardality of LXE. What is the +relationship? Well, it implies that the + + align:start position:0% +relationship? Well, it implies that the + + + align:start position:0% +relationship? Well, it implies that the +cardality of lexe is at least uh around + + align:start position:0% +cardality of lexe is at least uh around + + + align:start position:0% +cardality of lexe is at least uh around +delta to the minus s, but it could be + + align:start position:0% +delta to the minus s, but it could be + + + align:start position:0% +delta to the minus s, but it could be +much bigger. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Okay, so an example where these would be + + align:start position:0% +Okay, so an example where these would be + + + align:start position:0% +Okay, so an example where these would be +about the same is if lxe was sort of + + align:start position:0% +about the same is if lxe was sort of + + + align:start position:0% +about the same is if lxe was sort of +like an s-dimensional caner set. An + + align:start position:0% +like an s-dimensional caner set. An + + + align:start position:0% +like an s-dimensional caner set. An +example where they would be very + + align:start position:0% +example where they would be very + + + align:start position:0% +example where they would be very +different is uh if is if LXE was very + + align:start position:0% +different is uh if is if LXE was very + + + align:start position:0% +different is uh if is if LXE was very +clumped. So here's a piece of S1 and + + align:start position:0% +clumped. So here's a piece of S1 and + + + align:start position:0% +clumped. So here's a piece of S1 and +maybe LXE + + align:start position:0% +maybe LXE + + + align:start position:0% +maybe LXE +is clumped like that. So these dots + + align:start position:0% +is clumped like that. So these dots + + + align:start position:0% +is clumped like that. So these dots +represent Lexi. + + align:start position:0% + + + + align:start position:0% + +So if it was if if Lex was really + + align:start position:0% +So if it was if if Lex was really + + + align:start position:0% +So if it was if if Lex was really +clumped into a much smaller interval + + align:start position:0% +clumped into a much smaller interval + + + align:start position:0% +clumped into a much smaller interval +then um S would actually have to be + + align:start position:0% +then um S would actually have to be + + + align:start position:0% +then um S would actually have to be +zero. + + align:start position:0% +zero. + + + align:start position:0% +zero. +This is not a delta SC set except for S + + align:start position:0% +This is not a delta SC set except for S + + + align:start position:0% +This is not a delta SC set except for S +equals Z. + + align:start position:0% +equals Z. + + + align:start position:0% +equals Z. +On the other hand, the cardality of LXC + + align:start position:0% +On the other hand, the cardality of LXC + + + align:start position:0% +On the other hand, the cardality of LXC +in this picture is is is large and in + + align:start position:0% +in this picture is is is large and in + + + align:start position:0% +in this picture is is is large and in +particular, it's much larger than delta + + align:start position:0% +particular, it's much larger than delta + + + align:start position:0% +particular, it's much larger than delta +to the minus0. + + align:start position:0% + + + + align:start position:0% + +Okay, so this S is some non-conentration + + align:start position:0% +Okay, so this S is some non-conentration + + + align:start position:0% +Okay, so this S is some non-conentration +condition and non-conentration forces + + align:start position:0% +condition and non-conentration forces + + + align:start position:0% +condition and non-conentration forces +our set to be pretty big. But it could + + align:start position:0% +our set to be pretty big. But it could + + + align:start position:0% +our set to be pretty big. But it could +also be much bigger than that if it was + + align:start position:0% +also be much bigger than that if it was + + + align:start position:0% +also be much bigger than that if it was +kind of clumped. + + align:start position:0% + + + + align:start position:0% + +Okay. So let's uh let's try to imitate + + align:start position:0% +Okay. So let's uh let's try to imitate + + + align:start position:0% +Okay. So let's uh let's try to imitate +our proof. Uh I'm going to suppose that + + align:start position:0% +our proof. Uh I'm going to suppose that + + + align:start position:0% +our proof. Uh I'm going to suppose that +we're in the uniform case. + + align:start position:0% +we're in the uniform case. + + + align:start position:0% +we're in the uniform case. +So all of the lxe have the same s + + align:start position:0% +So all of the lxe have the same s + + + align:start position:0% +So all of the lxe have the same s +and the same size of lx. + + align:start position:0% + + + + align:start position:0% + +Okay, we can do our same double + + align:start position:0% +Okay, we can do our same double + + + align:start position:0% +Okay, we can do our same double +counting. + + align:start position:0% + + + + align:start position:0% + +That part doesn't change at all. And it + + align:start position:0% +That part doesn't change at all. And it + + + align:start position:0% +That part doesn't change at all. And it +has it gives us L E is at least + + align:start position:0% +has it gives us L E is at least + + + align:start position:0% +has it gives us L E is at least +L XE^2. + + align:start position:0% + + + + align:start position:0% + +Okay, sorry, is approximately LXE squ. + + align:start position:0% + + + + align:start position:0% + +And so to get a lower bound on LXE, it + + align:start position:0% +And so to get a lower bound on LXE, it + + + align:start position:0% +And so to get a lower bound on LXE, it +suffices to get a lower bound on LE. + + align:start position:0% + + + + align:start position:0% + +What happens here? Um so now we can + + align:start position:0% +What happens here? Um so now we can + + + align:start position:0% +What happens here? Um so now we can +apply the uh theorem of Orpin and + + align:start position:0% +apply the uh theorem of Orpin and + + + align:start position:0% +apply the uh theorem of Orpin and +Schmurkin epsilon improvement + + align:start position:0% +Schmurkin epsilon improvement + + + align:start position:0% +Schmurkin epsilon improvement +which I just erased in a suboptimal use + + align:start position:0% +which I just erased in a suboptimal use + + + align:start position:0% +which I just erased in a suboptimal use +of blackboards. Um but uh what it says + + align:start position:0% +of blackboards. Um but uh what it says + + + align:start position:0% +of blackboards. Um but uh what it says +in this case is uh that if u if s is + + align:start position:0% +in this case is uh that if u if s is + + + align:start position:0% +in this case is uh that if u if s is +smaller than the minimum of u and one + + align:start position:0% +smaller than the minimum of u and one + + + align:start position:0% +smaller than the minimum of u and one +but bigger than zero + + align:start position:0% +but bigger than zero + + + align:start position:0% +but bigger than zero +then we get + + align:start position:0% +then we get + + + align:start position:0% +then we get +le e is at least delta the minus 2s + + align:start position:0% +le e is at least delta the minus 2s + + + align:start position:0% +le e is at least delta the minus 2s +minus epsilon. So that this would be the + + align:start position:0% +minus epsilon. So that this would be the + + + align:start position:0% +minus epsilon. So that this would be the +classical bound + + align:start position:0% +classical bound + + + align:start position:0% +classical bound +and then we have this. + + align:start position:0% + + + + align:start position:0% + +Okay. And then we're interested in lxe. + + align:start position:0% +Okay. And then we're interested in lxe. + + + align:start position:0% +Okay. And then we're interested in lxe. +That tells us that lxe + + align:start position:0% +That tells us that lxe + + + align:start position:0% +That tells us that lxe +is at least delta to the minus s minus + + align:start position:0% +is at least delta to the minus s minus + + + align:start position:0% +is at least delta to the minus s minus +epsilon. + + align:start position:0% + + + + align:start position:0% + +Okay, so let's take stock. + + align:start position:0% +Okay, so let's take stock. + + + align:start position:0% +Okay, so let's take stock. +If S were equal to the minimum of U and + + align:start position:0% +If S were equal to the minimum of U and + + + align:start position:0% +If S were equal to the minimum of U and +one, then LXE would be at least delta to + + align:start position:0% +one, then LXE would be at least delta to + + + align:start position:0% +one, then LXE would be at least delta to +the minus S. That would be the bound we + + align:start position:0% +the minus S. That would be the bound we + + + align:start position:0% +the minus S. That would be the bound we +want to prove. So in that case, we would + + align:start position:0% +want to prove. So in that case, we would + + + align:start position:0% +want to prove. So in that case, we would +be very happy. + + align:start position:0% +be very happy. + + + align:start position:0% +be very happy. +Okay. Now suppose S is in this range. + + align:start position:0% +Okay. Now suppose S is in this range. + + + align:start position:0% +Okay. Now suppose S is in this range. +Well, then we get this bound. + + align:start position:0% +Well, then we get this bound. + + + align:start position:0% +Well, then we get this bound. +This bound is a tiny bit better than + + align:start position:0% +This bound is a tiny bit better than + + + align:start position:0% +This bound is a tiny bit better than +this bound, + + align:start position:0% + + + + align:start position:0% + +but that's all. + + align:start position:0% + + + + align:start position:0% + +This argument didn't work so nicely as + + align:start position:0% +This argument didn't work so nicely as + + + align:start position:0% +This argument didn't work so nicely as +that argument because in that case there + + align:start position:0% +that argument because in that case there + + + align:start position:0% +that argument because in that case there +was no distinction between cardality and + + align:start position:0% +was no distinction between cardality and + + + align:start position:0% +was no distinction between cardality and +the value of s. In that case this was + + align:start position:0% +the value of s. In that case this was + + + align:start position:0% +the value of s. In that case this was +the same as this. So we would get a + + align:start position:0% +the same as this. So we would get a + + + align:start position:0% +the same as this. So we would get a +contradiction at this moment and we + + align:start position:0% +contradiction at this moment and we + + + align:start position:0% +contradiction at this moment and we +could we could conclude that actually s + + align:start position:0% +could we could conclude that actually s + + + align:start position:0% +could we could conclude that actually s +is the minimum of u and one. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +Um so we did learn something. Um + + align:start position:0% +Um so we did learn something. Um + + + align:start position:0% +Um so we did learn something. Um +you know if if lxe were kind of spread + + align:start position:0% +you know if if lxe were kind of spread + + + align:start position:0% +you know if if lxe were kind of spread +out you then you might hope that the + + align:start position:0% +out you then you might hope that the + + + align:start position:0% +out you then you might hope that the +cardality would be about delta to the + + align:start position:0% +cardality would be about delta to the + + + align:start position:0% +cardality would be about delta to the +minus s and in that spread out case then + + align:start position:0% +minus s and in that spread out case then + + + align:start position:0% +minus s and in that spread out case then +we could get we would follow that that s + + align:start position:0% +we could get we would follow that that s + + + align:start position:0% +we could get we would follow that that s +was the minimum of u and one. + + align:start position:0% +was the minimum of u and one. + + + align:start position:0% +was the minimum of u and one. +So we see so we see this correlary + + align:start position:0% +So we see so we see this correlary + + + align:start position:0% +So we see so we see this correlary +if um + + align:start position:0% +if um + + + align:start position:0% +if um +lxe is a delta s set + + align:start position:0% +lxe is a delta s set + + + align:start position:0% +lxe is a delta s set +and the size of lxe + + align:start position:0% +and the size of lxe + + + align:start position:0% +and the size of lxe +is around delta to the minus s then we + + align:start position:0% +is around delta to the minus s then we + + + align:start position:0% +is around delta to the minus s then we +would get that the size of lxe is + + align:start position:0% +would get that the size of lxe is + + + align:start position:0% +would get that the size of lxe is +greater than around the minimum of delta + + align:start position:0% +greater than around the minimum of delta + + + align:start position:0% +greater than around the minimum of delta +to the minus u and delta to the minus1 + + align:start position:0% +to the minus u and delta to the minus1 + + + align:start position:0% +to the minus u and delta to the minus1 +and we would be happy. + + align:start position:0% +and we would be happy. + + + align:start position:0% +and we would be happy. +But it's a big if and we don't + + align:start position:0% +But it's a big if and we don't + + + align:start position:0% +But it's a big if and we don't +understand yet very well what might + + align:start position:0% +understand yet very well what might + + + align:start position:0% +understand yet very well what might +happen if these sets were a little more + + align:start position:0% +happen if these sets were a little more + + + align:start position:0% +happen if these sets were a little more +clumped. + + align:start position:0% + + + + align:start position:0% + +Okay. Cool. + + align:start position:0% + + + + align:start position:0% + +All right. So um let me put up a summary + + align:start position:0% +All right. So um let me put up a summary + + + align:start position:0% +All right. So um let me put up a summary +of what we've learned so far. So lama + + align:start position:0% + + + + align:start position:0% + +if s is bigger than zero and a typical + + align:start position:0% +if s is bigger than zero and a typical + + + align:start position:0% +if s is bigger than zero and a typical +lxe + + align:start position:0% +lxe + + + align:start position:0% +lxe +is delta sc. + + align:start position:0% +is delta sc. + + + align:start position:0% +is delta sc. +Um then + + align:start position:0% +Um then + + + align:start position:0% +Um then +size of typical lxe is at least delta to + + align:start position:0% +size of typical lxe is at least delta to + + + align:start position:0% +size of typical lxe is at least delta to +the minus s minus epsilon or sorry yeah + + align:start position:0% +the minus s minus epsilon or sorry yeah + + + align:start position:0% +the minus s minus epsilon or sorry yeah +if + + align:start position:0% +if + + + align:start position:0% +if +0 is less than s is less than the + + align:start position:0% +0 is less than s is less than the + + + align:start position:0% +0 is less than s is less than the +minimum of + + align:start position:0% + + + + align:start position:0% + +okay so the proof of this theorem we + + align:start position:0% +okay so the proof of this theorem we + + + align:start position:0% +okay so the proof of this theorem we +don't have it yet we have this lema um + + align:start position:0% +don't have it yet we have this lema um + + + align:start position:0% +don't have it yet we have this lema um +the proof of this theorem is by + + align:start position:0% +the proof of this theorem is by + + + align:start position:0% +the proof of this theorem is by +bootstrapping this lema using it many + + align:start position:0% +bootstrapping this lema using it many + + + align:start position:0% +bootstrapping this lema using it many +times at different scales and locations. + + align:start position:0% +times at different scales and locations. + + + align:start position:0% +times at different scales and locations. +So we are effectively using the epsilon + + align:start position:0% +So we are effectively using the epsilon + + + align:start position:0% +So we are effectively using the epsilon +improvement many times not just once and + + align:start position:0% +improvement many times not just once and + + + align:start position:0% +improvement many times not just once and +at many scales. + + align:start position:0% + + + + align:start position:0% + +about it. + + align:start position:0% +about it. + + + align:start position:0% +about it. +[Applause] + + align:start position:0% + + + + align:start position:0% + +All right. So, let's do a sketch of this + + align:start position:0% +All right. So, let's do a sketch of this + + + align:start position:0% +All right. So, let's do a sketch of this +bootstrap iteration. + + align:start position:0% + + + + align:start position:0% + +Okay. Um so we're going to suppose + + align:start position:0% +Okay. Um so we're going to suppose + + + align:start position:0% +Okay. Um so we're going to suppose +that lxe first of all is uniform + + align:start position:0% + + + + align:start position:0% + +and also that it is delta sc for some s + + align:start position:0% +and also that it is delta sc for some s + + + align:start position:0% +and also that it is delta sc for some s +which is bigger than zero. It's the + + align:start position:0% +which is bigger than zero. It's the + + + align:start position:0% +which is bigger than zero. It's the +start of our bootstrap. + + align:start position:0% + + + + align:start position:0% + +So because it's uniform and it's a delta + + align:start position:0% +So because it's uniform and it's a delta + + + align:start position:0% +So because it's uniform and it's a delta +SC set then it follows that if you take + + align:start position:0% +SC set then it follows that if you take + + + align:start position:0% +SC set then it follows that if you take +its sort of its row neighborhood then + + align:start position:0% +its sort of its row neighborhood then + + + align:start position:0% +its sort of its row neighborhood then +this is a row SC set + + align:start position:0% +this is a row SC set + + + align:start position:0% +this is a row SC set +for every row. + + align:start position:0% +for every row. + + + align:start position:0% +for every row. +And now we can apply our lema. + + align:start position:0% +And now we can apply our lema. + + + align:start position:0% +And now we can apply our lema. +And the lema tells us that the cardality + + align:start position:0% +And the lema tells us that the cardality + + + align:start position:0% +And the lema tells us that the cardality +of lxe the row covering number of lxe + + align:start position:0% +of lxe the row covering number of lxe + + + align:start position:0% +of lxe the row covering number of lxe +is at least + + align:start position:0% +is at least + + + align:start position:0% +is at least +row to the minus s minus epsilon. So row + + align:start position:0% +row to the minus s minus epsilon. So row + + + align:start position:0% +row to the minus s minus epsilon. So row +to the minus s is what we get just from + + align:start position:0% +to the minus s is what we get just from + + + align:start position:0% +to the minus s is what we get just from +being a row sc set. But actually has to + + align:start position:0% +being a row sc set. But actually has to + + + align:start position:0% +being a row sc set. But actually has to +be a little bit bigger than that by our + + align:start position:0% +be a little bit bigger than that by our + + + align:start position:0% +be a little bit bigger than that by our +lema. + + align:start position:0% +lema. + + + align:start position:0% +lema. +And that's true for every row. + + align:start position:0% +And that's true for every row. + + + align:start position:0% +And that's true for every row. +And now since since we have a uniform + + align:start position:0% +And now since since we have a uniform + + + align:start position:0% +And now since since we have a uniform +set + + align:start position:0% + + + + align:start position:0% + +and since these row covering numbers are + + align:start position:0% +and since these row covering numbers are + + + align:start position:0% +and since these row covering numbers are +a little bit bigger than expected tells + + align:start position:0% +a little bit bigger than expected tells + + + align:start position:0% +a little bit bigger than expected tells +us that lxe + + align:start position:0% +us that lxe + + + align:start position:0% +us that lxe +is a delta s plus epsilon c set. + + align:start position:0% + + + + align:start position:0% + +Yeah, actually I should here I needed to + + align:start position:0% +Yeah, actually I should here I needed to + + + align:start position:0% +Yeah, actually I should here I needed to +put 0 is less than s is less than the + + align:start position:0% +put 0 is less than s is less than the + + + align:start position:0% +put 0 is less than s is less than the +minimum of e1. + + align:start position:0% +minimum of e1. + + + align:start position:0% +minimum of e1. +We used all of these are hypotheses of + + align:start position:0% +We used all of these are hypotheses of + + + align:start position:0% +We used all of these are hypotheses of +our lema. So we use them here. + + align:start position:0% +our lema. So we use them here. + + + align:start position:0% +our lema. So we use them here. +Okay. Now this is our starting + + align:start position:0% +Okay. Now this is our starting + + + align:start position:0% +Okay. Now this is our starting +hypothesis. So now we can iterate. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +So s keeps getting bigger and bigger as + + align:start position:0% +So s keeps getting bigger and bigger as + + + align:start position:0% +So s keeps getting bigger and bigger as +long as it's smaller than the minimum of + + align:start position:0% +long as it's smaller than the minimum of + + + align:start position:0% +long as it's smaller than the minimum of +u and one. And so it will approach the + + align:start position:0% +u and one. And so it will approach the + + + align:start position:0% +u and one. And so it will approach the +minimum of u and one + + align:start position:0% + + + + align:start position:0% + +and then we're happy. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So unlike in the proof of beex theorem + + align:start position:0% +So unlike in the proof of beex theorem + + + align:start position:0% +So unlike in the proof of beex theorem +we had to use this lama many times. We + + align:start position:0% +we had to use this lama many times. We + + + align:start position:0% +we had to use this lama many times. We +used it at many different scales and + + align:start position:0% +used it at many different scales and + + + align:start position:0% +used it at many different scales and +also we had to use it over and over + + align:start position:0% +also we had to use it over and over + + + align:start position:0% +also we had to use it over and over +again and each time we used it we + + align:start position:0% +again and each time we used it we + + + align:start position:0% +again and each time we used it we +improved this exponent a little bit + + align:start position:0% +improved this exponent a little bit + + + align:start position:0% +improved this exponent a little bit +until the exponent approached the + + align:start position:0% +until the exponent approached the + + + align:start position:0% +until the exponent approached the +exponent that we had in the classical + + align:start position:0% +exponent that we had in the classical + + + align:start position:0% +exponent that we had in the classical +vest. + + align:start position:0% +vest. + + + align:start position:0% +vest. +And so this is sort of typical of this + + align:start position:0% +And so this is sort of typical of this + + + align:start position:0% +And so this is sort of typical of this +new paradigm that you can take an + + align:start position:0% +new paradigm that you can take an + + + align:start position:0% +new paradigm that you can take an +epsilon improvement result and use it + + align:start position:0% +epsilon improvement result and use it + + + align:start position:0% +epsilon improvement result and use it +over and over again to keep epsilon + + align:start position:0% +over and over again to keep epsilon + + + align:start position:0% +over and over again to keep epsilon +improving something until the thing + + align:start position:0% +improving something until the thing + + + align:start position:0% +improving something until the thing +reaches the sharp value. + + align:start position:0% +reaches the sharp value. + + + align:start position:0% +reaches the sharp value. +Okay. Now you might be wondering how we + + align:start position:0% +Okay. Now you might be wondering how we + + + align:start position:0% +Okay. Now you might be wondering how we +started this argument. We needed to + + align:start position:0% +started this argument. We needed to + + + align:start position:0% +started this argument. We needed to +start with an S that was bigger than + + align:start position:0% +start with an S that was bigger than + + + align:start position:0% +start with an S that was bigger than +zero. And not every set is a delta SC c + + align:start position:0% +zero. And not every set is a delta SC c + + + align:start position:0% +zero. And not every set is a delta SC c +set for any s. + + align:start position:0% +set for any s. + + + align:start position:0% +set for any s. +Um so to start the argument + + align:start position:0% +Um so to start the argument + + + align:start position:0% +Um so to start the argument +we observe um that we had this + + align:start position:0% +we observe um that we had this + + + align:start position:0% +we observe um that we had this +non-conentration in rectangles + + align:start position:0% +non-conentration in rectangles + + + align:start position:0% +non-conentration in rectangles +condition. + + align:start position:0% +condition. + + + align:start position:0% +condition. +on concentration and rectangles + + align:start position:0% +on concentration and rectangles + + + align:start position:0% +on concentration and rectangles +condition here that our set is not too + + align:start position:0% +condition here that our set is not too + + + align:start position:0% +condition here that our set is not too +much in any rectangle. + + align:start position:0% +much in any rectangle. + + + align:start position:0% +much in any rectangle. +We haven't mentioned that hypothesis + + align:start position:0% +We haven't mentioned that hypothesis + + + align:start position:0% +We haven't mentioned that hypothesis +yet. We use it here to get started. So + + align:start position:0% +yet. We use it here to get started. So + + + align:start position:0% +yet. We use it here to get started. So +to start with + + align:start position:0% +to start with + + + align:start position:0% +to start with +non-conentration in rectangles uh easily + + align:start position:0% +non-conentration in rectangles uh easily + + + align:start position:0% +non-conentration in rectangles uh easily +implies that lxe is a delta ad set. + + align:start position:0% +implies that lxe is a delta ad set. + + + align:start position:0% +implies that lxe is a delta ad set. +[Applause] + + align:start position:0% + + + + align:start position:0% + +Um because so if E looks like so there's + + align:start position:0% +Um because so if E looks like so there's + + + align:start position:0% +Um because so if E looks like so there's +not too much of E in any rectangle + + align:start position:0% +not too much of E in any rectangle + + + align:start position:0% +not too much of E in any rectangle +is our X. Therefore there aren't too + + align:start position:0% +is our X. Therefore there aren't too + + + align:start position:0% +is our X. Therefore there aren't too +many of these rectangles too much. You + + align:start position:0% +many of these rectangles too much. You + + + align:start position:0% +many of these rectangles too much. You +can't have if you had a lot of lxe in a + + align:start position:0% +can't have if you had a lot of lxe in a + + + align:start position:0% +can't have if you had a lot of lxe in a +small angular range it would mean you + + align:start position:0% +small angular range it would mean you + + + align:start position:0% +small angular range it would mean you +had a lot of E in a small rectangle. And + + align:start position:0% +had a lot of E in a small rectangle. And + + + align:start position:0% +had a lot of E in a small rectangle. And +that says this doesn't happen. + + align:start position:0% + + + + align:start position:0% + +Okay cool. So now we have sketched the + + align:start position:0% +Okay cool. So now we have sketched the + + + align:start position:0% +Okay cool. So now we have sketched the +proof of the continuum beex theorem the + + align:start position:0% +proof of the continuum beex theorem the + + + align:start position:0% +proof of the continuum beex theorem the +first sharp theorem in projection theory + + align:start position:0% +first sharp theorem in projection theory + + + align:start position:0% +first sharp theorem in projection theory +distinguishing R from C. So let's take a + + align:start position:0% +distinguishing R from C. So let's take a + + + align:start position:0% +distinguishing R from C. So let's take a +take a couple minutes to digest see if + + align:start position:0% +take a couple minutes to digest see if + + + align:start position:0% +take a couple minutes to digest see if +you have questions or comments. + + align:start position:0% + + + + align:start position:0% + +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +>> On the uh I guess kind of the second + + align:start position:0% +>> On the uh I guess kind of the second + + + align:start position:0% +>> On the uh I guess kind of the second +step of proof would be Lexe row is that + + align:start position:0% +step of proof would be Lexe row is that + + + align:start position:0% +step of proof would be Lexe row is that +the intersection of LXE with a kind of + + align:start position:0% +the intersection of LXE with a kind of + + + align:start position:0% +the intersection of LXE with a kind of +row radius ball or + + align:start position:0% +row radius ball or + + + align:start position:0% +row radius ball or +>> sorry. Um so lxe e row is the row + + align:start position:0% +>> sorry. Um so lxe e row is the row + + + align:start position:0% +>> sorry. Um so lxe e row is the row +neighborhood + + align:start position:0% +neighborhood + + + align:start position:0% +neighborhood +of lx. Actually you can also you can + + align:start position:0% +of lx. Actually you can also you can + + + align:start position:0% +of lx. Actually you can also you can +also erase the row. Maybe that's the + + align:start position:0% +also erase the row. Maybe that's the + + + align:start position:0% +also erase the row. Maybe that's the +best thing to do. + + align:start position:0% +best thing to do. + + + align:start position:0% +best thing to do. +Okay. So lxe is a delta SC set and if + + align:start position:0% +Okay. So lxe is a delta SC set and if + + + align:start position:0% +Okay. So lxe is a delta SC set and if +it's uniform it's also a row SC set for + + align:start position:0% +it's uniform it's also a row SC set for + + + align:start position:0% +it's uniform it's also a row SC set for +all the bigger rows for row delta + + align:start position:0% +all the bigger rows for row delta + + + align:start position:0% +all the bigger rows for row delta +>> for yeah for all row. Yeah. + + align:start position:0% +>> for yeah for all row. Yeah. + + + align:start position:0% +>> for yeah for all row. Yeah. +Yeah. Thank you. Thank you. + + align:start position:0% +Yeah. Thank you. Thank you. + + + align:start position:0% +Yeah. Thank you. Thank you. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Okay. Yeah. So, so recap. So, we don't + + align:start position:0% +Okay. Yeah. So, so recap. So, we don't + + + align:start position:0% +Okay. Yeah. So, so recap. So, we don't +so we don't Yeah. We don't we don't need + + align:start position:0% +so we don't Yeah. We don't we don't need + + + align:start position:0% +so we don't Yeah. We don't we don't need +to mention the right. So, so say it + + align:start position:0% +to mention the right. So, so say it + + + align:start position:0% +to mention the right. So, so say it +again. So, LXE is is uniform set. If + + align:start position:0% +again. So, LXE is is uniform set. If + + + align:start position:0% +again. So, LXE is is uniform set. If +it's delta SC, then it's also row SC for + + align:start position:0% +it's delta SC, then it's also row SC for + + + align:start position:0% +it's delta SC, then it's also row SC for +all the bigger rows. And so, then we get + + align:start position:0% +all the bigger rows. And so, then we get + + + align:start position:0% +all the bigger rows. And so, then we get +these covering numbers and then get + + align:start position:0% +these covering numbers and then get + + + align:start position:0% +these covering numbers and then get +okay. Okay. So let me share a personal + + align:start position:0% +okay. Okay. So let me share a personal + + + align:start position:0% +okay. Okay. So let me share a personal +reaction. So when this paper came out + + align:start position:0% +reaction. So when this paper came out + + + align:start position:0% +reaction. So when this paper came out +first of all I was very impressed + + align:start position:0% +first of all I was very impressed + + + align:start position:0% +first of all I was very impressed +because it was you know I had been + + align:start position:0% +because it was you know I had been + + + align:start position:0% +because it was you know I had been +wondering about this for many years and + + align:start position:0% +wondering about this for many years and + + + align:start position:0% +wondering about this for many years and +it's the first sharp projection type + + align:start position:0% +it's the first sharp projection type + + + align:start position:0% +it's the first sharp projection type +theorem which distinguishes R from C. + + align:start position:0% +theorem which distinguishes R from C. + + + align:start position:0% +theorem which distinguishes R from C. +But I also + + align:start position:0% +But I also + + + align:start position:0% +But I also +felt kind of unsure whether this would + + align:start position:0% +felt kind of unsure whether this would + + + align:start position:0% +felt kind of unsure whether this would +open the door to prove sharp results for + + align:start position:0% +open the door to prove sharp results for + + + align:start position:0% +open the door to prove sharp results for +things like the first set problem. Uh + + align:start position:0% +things like the first set problem. Uh + + + align:start position:0% +things like the first set problem. Uh +maybe it's a sharp result but maybe it's + + align:start position:0% +maybe it's a sharp result but maybe it's + + + align:start position:0% +maybe it's a sharp result but maybe it's +about a kind of thing that somehow is + + align:start position:0% +about a kind of thing that somehow is + + + align:start position:0% +about a kind of thing that somehow is +more approachable. It was well known + + align:start position:0% +more approachable. It was well known + + + align:start position:0% +more approachable. It was well known +classically that a epsilon improvement + + align:start position:0% +classically that a epsilon improvement + + + align:start position:0% +classically that a epsilon improvement +of something implied a sharp version of + + align:start position:0% +of something implied a sharp version of + + + align:start position:0% +of something implied a sharp version of +the class of the incidence geometry + + align:start position:0% +the class of the incidence geometry + + + align:start position:0% +the class of the incidence geometry +something here and that's just not the + + align:start position:0% +something here and that's just not the + + + align:start position:0% +something here and that's just not the +case for semary trotder. Sem ready + + align:start position:0% +case for semary trotder. Sem ready + + + align:start position:0% +case for semary trotder. Sem ready +trotder is not known to follow from an + + align:start position:0% +trotder is not known to follow from an + + + align:start position:0% +trotder is not known to follow from an +epsilon improvement on on some classical + + align:start position:0% +epsilon improvement on on some classical + + + align:start position:0% +epsilon improvement on on some classical +thing. Um and so it wasn't clear to me + + align:start position:0% +thing. Um and so it wasn't clear to me + + + align:start position:0% +thing. Um and so it wasn't clear to me +if this would open the door to prove + + align:start position:0% +if this would open the door to prove + + + align:start position:0% +if this would open the door to prove +sharp theorems about all the things we + + align:start position:0% +sharp theorems about all the things we + + + align:start position:0% +sharp theorems about all the things we +most cared about. + + align:start position:0% +most cared about. + + + align:start position:0% +most cared about. +All right. Um so in the rest of this + + align:start position:0% +All right. Um so in the rest of this + + + align:start position:0% +All right. Um so in the rest of this +class what I want to do is to uh give a + + align:start position:0% +class what I want to do is to uh give a + + + align:start position:0% +class what I want to do is to uh give a +give a outline of the proof of the of + + align:start position:0% +give a outline of the proof of the of + + + align:start position:0% +give a outline of the proof of the of +the of the first set conjecture and the + + align:start position:0% +the of the first set conjecture and the + + + align:start position:0% +the of the first set conjecture and the +different ingredients that go into it of + + align:start position:0% +different ingredients that go into it of + + + align:start position:0% +different ingredients that go into it of +which this will turn out to be an + + align:start position:0% +which this will turn out to be an + + + align:start position:0% +which this will turn out to be an +important one. + + align:start position:0% +important one. + + + align:start position:0% +important one. +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +cool. So the the first thing to say is + + align:start position:0% +cool. So the the first thing to say is + + + align:start position:0% +cool. So the the first thing to say is +that this proof breaks into cases + + align:start position:0% +that this proof breaks into cases + + + align:start position:0% +that this proof breaks into cases +according to the way the the set E is + + align:start position:0% +according to the way the the set E is + + + align:start position:0% +according to the way the the set E is +spaced that this del this delta TC set + + align:start position:0% +spaced that this del this delta TC set + + + align:start position:0% +spaced that this del this delta TC set +that definition on the one hand it's a + + align:start position:0% +that definition on the one hand it's a + + + align:start position:0% +that definition on the one hand it's a +good definition but under the umbrella + + align:start position:0% +good definition but under the umbrella + + + align:start position:0% +good definition but under the umbrella +of delta TC sets there are several diff + + align:start position:0% +of delta TC sets there are several diff + + + align:start position:0% +of delta TC sets there are several diff +quite different ways that the set E + + align:start position:0% +quite different ways that the set E + + + align:start position:0% +quite different ways that the set E +could be spaced and we have to pay + + align:start position:0% +could be spaced and we have to pay + + + align:start position:0% +could be spaced and we have to pay +attention to them and we have to treat + + align:start position:0% +attention to them and we have to treat + + + align:start position:0% +attention to them and we have to treat +them in different ways. + + align:start position:0% +them in different ways. + + + align:start position:0% +them in different ways. +All right. So, let's explain that. + + align:start position:0% + + + + align:start position:0% + +So, we're going to split into cases + + align:start position:0% +So, we're going to split into cases + + + align:start position:0% +So, we're going to split into cases +according + + align:start position:0% + + + + align:start position:0% + +to how + + align:start position:0% +to how + + + align:start position:0% +to how +E is spaced. + + align:start position:0% + + + + align:start position:0% + +All right. So first of all, let's assume + + align:start position:0% +All right. So first of all, let's assume + + + align:start position:0% +All right. So first of all, let's assume +that E is uniform. + + align:start position:0% +that E is uniform. + + + align:start position:0% +that E is uniform. +And I'll now I mentioned the word + + align:start position:0% +And I'll now I mentioned the word + + + align:start position:0% +And I'll now I mentioned the word +uniform above, but now I'll remember + + align:start position:0% +uniform above, but now I'll remember + + + align:start position:0% +uniform above, but now I'll remember +recall exactly what is uniform. + + align:start position:0% +recall exactly what is uniform. + + + align:start position:0% +recall exactly what is uniform. +Okay. So first of all, our delta is + + align:start position:0% +Okay. So first of all, our delta is + + + align:start position:0% +Okay. So first of all, our delta is +going to be + + align:start position:0% +going to be + + + align:start position:0% +going to be +capital delta to the M where M is a + + align:start position:0% +capital delta to the M where M is a + + + align:start position:0% +capital delta to the M where M is a +large number. + + align:start position:0% +large number. + + + align:start position:0% +large number. +And uniform means that for every J going + + align:start position:0% +And uniform means that for every J going + + + align:start position:0% +And uniform means that for every J going +from one up to M and for every Q which + + align:start position:0% +from one up to M and for every Q which + + + align:start position:0% +from one up to M and for every Q which +is a delta to the J cub. + + align:start position:0% +is a delta to the J cub. + + + align:start position:0% +is a delta to the J cub. +Then when I take my set and I intersect + + align:start position:0% +Then when I take my set and I intersect + + + align:start position:0% +Then when I take my set and I intersect +it with Q and I cover it with cubes or + + align:start position:0% +it with Q and I cover it with cubes or + + + align:start position:0% +it with Q and I cover it with cubes or +balls at the next smaller scale delta to + + align:start position:0% +balls at the next smaller scale delta to + + + align:start position:0% +balls at the next smaller scale delta to +the J + one. Um that is is around RJ. So + + align:start position:0% +the J + one. Um that is is around RJ. So + + + align:start position:0% +the J + one. Um that is is around RJ. So +um + + align:start position:0% + + + + align:start position:0% + +so I'll draw some pictures in a moment. + + align:start position:0% +so I'll draw some pictures in a moment. + + + align:start position:0% +so I'll draw some pictures in a moment. +The smallest this RJ could be is one and + + align:start position:0% +The smallest this RJ could be is one and + + + align:start position:0% +The smallest this RJ could be is one and +the biggest it could be is big delta to + + align:start position:0% +the biggest it could be is big delta to + + + align:start position:0% +the biggest it could be is big delta to +the minus2. + + align:start position:0% +the minus2. + + + align:start position:0% +the minus2. +Oh + + align:start position:0% +Oh + + + align:start position:0% +Oh +um + + align:start position:0% + + + + align:start position:0% + +actually yeah let me say a little bit + + align:start position:0% +actually yeah let me say a little bit + + + align:start position:0% +actually yeah let me say a little bit +more. So the delta covering number of v + + align:start position:0% +more. So the delta covering number of v + + + align:start position:0% +more. So the delta covering number of v +that's going to be the product j = 1 to + + align:start position:0% +that's going to be the product j = 1 to + + + align:start position:0% +that's going to be the product j = 1 to +m of rj. + + align:start position:0% + + + + align:start position:0% + +Um and another thing we we can say is if + + align:start position:0% +Um and another thing we we can say is if + + + align:start position:0% +Um and another thing we we can say is if +I if I were to take the product J equals + + align:start position:0% +I if I were to take the product J equals + + + align:start position:0% +I if I were to take the product J equals +1 to capital J of RJ that would be the + + align:start position:0% +1 to capital J of RJ that would be the + + + align:start position:0% +1 to capital J of RJ that would be the +covering number of E at scale delta to + + align:start position:0% +covering number of E at scale delta to + + + align:start position:0% +covering number of E at scale delta to +the capital J + + align:start position:0% +the capital J + + + align:start position:0% +the capital J +and that should be so + + align:start position:0% +and that should be so + + + align:start position:0% +and that should be so +um let's say so + + align:start position:0% +um let's say so + + + align:start position:0% +um let's say so +so if E is a deltat TC + + align:start position:0% +so if E is a deltat TC + + + align:start position:0% +so if E is a deltat TC +Then this should be at least 1 / C um + + align:start position:0% +Then this should be at least 1 / C um + + + align:start position:0% +Then this should be at least 1 / C um +delta J to the minus. + + align:start position:0% +delta J to the minus. + + + align:start position:0% +delta J to the minus. +So that gives some information about + + align:start position:0% +So that gives some information about + + + align:start position:0% +So that gives some information about +these products and + + align:start position:0% +these products and + + + align:start position:0% +these products and +being a delta TC set is equivalent to + + align:start position:0% +being a delta TC set is equivalent to + + + align:start position:0% +being a delta TC set is equivalent to +this information about these products. + + align:start position:0% +this information about these products. + + + align:start position:0% +this information about these products. +And so there are many ways that they + + align:start position:0% +And so there are many ways that they + + + align:start position:0% +And so there are many ways that they +could look. + + align:start position:0% +could look. + + + align:start position:0% +could look. +Okay, let me put up a couple of examples + + align:start position:0% +Okay, let me put up a couple of examples + + + align:start position:0% +Okay, let me put up a couple of examples +which also should hopefully clarify + + align:start position:0% +which also should hopefully clarify + + + align:start position:0% +which also should hopefully clarify +everything on this board and then we + + align:start position:0% +everything on this board and then we + + + align:start position:0% +everything on this board and then we +pause for questions. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +All right. + + align:start position:0% + + + + align:start position:0% + +Okay. So the first example that I want + + align:start position:0% +Okay. So the first example that I want + + + align:start position:0% +Okay. So the first example that I want +to put up + + align:start position:0% +to put up + + + align:start position:0% +to put up +is that all the RJs are the same. So RJ + + align:start position:0% +is that all the RJs are the same. So RJ + + + align:start position:0% +is that all the RJs are the same. So RJ +is delta to the minus T for every J. + + align:start position:0% +is delta to the minus T for every J. + + + align:start position:0% +is delta to the minus T for every J. +Okay. And then you'll + + align:start position:0% +Okay. And then you'll + + + align:start position:0% +Okay. And then you'll +see that this this will be okay. + + align:start position:0% + + + + align:start position:0% + +Um all right. And I'd like to visualize + + align:start position:0% +Um all right. And I'd like to visualize + + + align:start position:0% +Um all right. And I'd like to visualize +this in two ways. + + align:start position:0% + + + + align:start position:0% + +So the first way I'd like to visualize + + align:start position:0% +So the first way I'd like to visualize + + + align:start position:0% +So the first way I'd like to visualize +is as a tree. Um so oh in my + + align:start position:0% +is as a tree. Um so oh in my + + + align:start position:0% +is as a tree. Um so oh in my +visualization I picked that delta is + + align:start position:0% +visualization I picked that delta is + + + align:start position:0% +visualization I picked that delta is +four. Delt no delta is uh 16. Um and no + + align:start position:0% +four. Delt no delta is uh 16. Um and no + + + align:start position:0% +four. Delt no delta is uh 16. Um and no +sorry del sorry delta is one pointer and + + align:start position:0% +sorry del sorry delta is one pointer and + + + align:start position:0% +sorry del sorry delta is one pointer and +we and t is going to be one. + + align:start position:0% +we and t is going to be one. + + + align:start position:0% +we and t is going to be one. +Okay. So in in my visualization delta to + + align:start position:0% +Okay. So in in my visualization delta to + + + align:start position:0% +Okay. So in in my visualization delta to +the minus one is going to be four. I'm + + align:start position:0% +the minus one is going to be four. I'm + + + align:start position:0% +the minus one is going to be four. I'm +going to have tree. So that be r1 guys + + align:start position:0% +going to have tree. So that be r1 guys + + + align:start position:0% +going to have tree. So that be r1 guys +coming out of it. And then each of these + + align:start position:0% +coming out of it. And then each of these + + + align:start position:0% +coming out of it. And then each of these +have r2 which is also four uh uh + + align:start position:0% +have r2 which is also four uh uh + + + align:start position:0% +have r2 which is also four uh uh +branches coming out. I won't draw that + + align:start position:0% +branches coming out. I won't draw that + + + align:start position:0% +branches coming out. I won't draw that +but they're all the same. + + align:start position:0% +but they're all the same. + + + align:start position:0% +but they're all the same. +Okay. Now let's do the next stage of our + + align:start position:0% +Okay. Now let's do the next stage of our + + + align:start position:0% +Okay. Now let's do the next stage of our +visualization. We started with a square. + + align:start position:0% +visualization. We started with a square. + + + align:start position:0% +visualization. We started with a square. +and we cut it into smaller squares of + + align:start position:0% +and we cut it into smaller squares of + + + align:start position:0% +and we cut it into smaller squares of +side length delta. So that looked like + + align:start position:0% +side length delta. So that looked like + + + align:start position:0% +side length delta. So that looked like +this. + + align:start position:0% +this. + + + align:start position:0% +this. +This is stage one + + align:start position:0% +This is stage one + + + align:start position:0% +This is stage one +and r sub one is four. So we took four. + + align:start position:0% +and r sub one is four. So we took four. + + + align:start position:0% +and r sub one is four. So we took four. +So maybe this one. + + align:start position:0% + + + + align:start position:0% + +Okay. Stage two. + + align:start position:0% +Okay. Stage two. + + + align:start position:0% +Okay. Stage two. +inside of each of those four squares. + + align:start position:0% + + + + align:start position:0% + +I took each of them and I cut them into + + align:start position:0% +I took each of them and I cut them into + + + align:start position:0% +I took each of them and I cut them into +a 4x4 grid of smaller squares. And I + + align:start position:0% +a 4x4 grid of smaller squares. And I + + + align:start position:0% +a 4x4 grid of smaller squares. And I +took four of them. So I'll do the + + align:start position:0% +took four of them. So I'll do the + + + align:start position:0% +took four of them. So I'll do the +cutting carefully here. Right. So maybe + + align:start position:0% +cutting carefully here. Right. So maybe + + + align:start position:0% +cutting carefully here. Right. So maybe +I took + + align:start position:0% +I took + + + align:start position:0% +I took +those four and then down here I took + + align:start position:0% +those four and then down here I took + + + align:start position:0% +those four and then down here I took +four + + align:start position:0% +four + + + align:start position:0% +four +and over here I took four and over here + + align:start position:0% +and over here I took four and over here + + + align:start position:0% +and over here I took four and over here +I took four. + + align:start position:0% + + + + align:start position:0% + +So our set looks something like that at + + align:start position:0% +So our set looks something like that at + + + align:start position:0% +So our set looks something like that at +stage two in a new + + align:start position:0% +stage two in a new + + + align:start position:0% +stage two in a new +All right. So this is the first example. + + align:start position:0% +All right. So this is the first example. + + + align:start position:0% +All right. So this is the first example. +It's called the ad regular example. + + align:start position:0% +It's called the ad regular example. + + + align:start position:0% +It's called the ad regular example. +Alforce devided regular. Alforce and + + align:start position:0% +Alforce devided regular. Alforce and + + + align:start position:0% +Alforce devided regular. Alforce and +Devid are two people who worked on stuff + + align:start position:0% +Devid are two people who worked on stuff + + + align:start position:0% +Devid are two people who worked on stuff +that is related to this. And the word + + align:start position:0% +that is related to this. And the word + + + align:start position:0% +that is related to this. And the word +regular I think here refers to the fact + + align:start position:0% +regular I think here refers to the fact + + + align:start position:0% +regular I think here refers to the fact +that all the scales are the same as each + + align:start position:0% +that all the scales are the same as each + + + align:start position:0% +that all the scales are the same as each +other. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now let me show you an opposite extreme. + + align:start position:0% + + + + align:start position:0% + +Okay. So this one is called the well + + align:start position:0% +Okay. So this one is called the well + + + align:start position:0% +Okay. So this one is called the well +spaced example. + + align:start position:0% +spaced example. + + + align:start position:0% +spaced example. +So in the well spaced example, RJ is as + + align:start position:0% +So in the well spaced example, RJ is as + + + align:start position:0% +So in the well spaced example, RJ is as +big as it could be its maximum value for + + align:start position:0% +big as it could be its maximum value for + + + align:start position:0% +big as it could be its maximum value for +some range of J + + align:start position:0% +some range of J + + + align:start position:0% +some range of J +and then RJ is one for larger of J. + + align:start position:0% + + + + align:start position:0% + +Okay. So as a picture it would look like + + align:start position:0% +Okay. So as a picture it would look like + + + align:start position:0% +Okay. So as a picture it would look like +this. So we're going to visualize + + align:start position:0% +this. So we're going to visualize + + + align:start position:0% +this. So we're going to visualize +with uh big J is one, big F is two like + + align:start position:0% +with uh big J is one, big F is two like + + + align:start position:0% +with uh big J is one, big F is two like +over there. So we'll have two stages. + + align:start position:0% +over there. So we'll have two stages. + + + align:start position:0% +over there. So we'll have two stages. +And so our first stage is that R1 is 16. + + align:start position:0% +And so our first stage is that R1 is 16. + + + align:start position:0% +And so our first stage is that R1 is 16. +Draw it off. And then R2 is one. So from + + align:start position:0% +Draw it off. And then R2 is one. So from + + + align:start position:0% +Draw it off. And then R2 is one. So from +each uh point here, we have just one + + align:start position:0% +each uh point here, we have just one + + + align:start position:0% +each uh point here, we have just one +going down. + + align:start position:0% +going down. + + + align:start position:0% +going down. +So the tree looks like this instead of + + align:start position:0% +So the tree looks like this instead of + + + align:start position:0% +So the tree looks like this instead of +like that. A lot of branching at the + + align:start position:0% +like that. A lot of branching at the + + + align:start position:0% +like that. A lot of branching at the +beginning and then no branching after + + align:start position:0% +beginning and then no branching after + + + align:start position:0% +beginning and then no branching after +that. + + align:start position:0% +that. + + + align:start position:0% +that. +Okay. What does it mean? Our set looks + + align:start position:0% +Okay. What does it mean? Our set looks + + + align:start position:0% +Okay. What does it mean? Our set looks +like in space. Well, first stage one, I + + align:start position:0% +like in space. Well, first stage one, I + + + align:start position:0% +like in space. Well, first stage one, I +take my square and I break it into 16 + + align:start position:0% +take my square and I break it into 16 + + + align:start position:0% +take my square and I break it into 16 +squares of side length a quarter. + + align:start position:0% +squares of side length a quarter. + + + align:start position:0% +squares of side length a quarter. +And at stage one, I select all 16 of + + align:start position:0% +And at stage one, I select all 16 of + + + align:start position:0% +And at stage one, I select all 16 of +them. So the picture looks like this. + + align:start position:0% + + + + align:start position:0% + +Okay, now at stage two. + + align:start position:0% + + + + align:start position:0% + +So I have cut my square into 16 squares + + align:start position:0% +So I have cut my square into 16 squares + + + align:start position:0% +So I have cut my square into 16 squares +of side length a quarter and I look + + align:start position:0% +of side length a quarter and I look + + + align:start position:0% +of side length a quarter and I look +inside each one of them. I cut that into + + align:start position:0% +inside each one of them. I cut that into + + + align:start position:0% +inside each one of them. I cut that into +16 squares a smaller size and I pick one + + align:start position:0% +16 squares a smaller size and I pick one + + + align:start position:0% +16 squares a smaller size and I pick one +of them + + align:start position:0% +of them + + + align:start position:0% +of them +and I do that in all in all the ones I + + align:start position:0% +and I do that in all in all the ones I + + + align:start position:0% +and I do that in all in all the ones I +selected at stage one which is all of + + align:start position:0% +selected at stage one which is all of + + + align:start position:0% +selected at stage one which is all of +them. So this set looks like this. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +so this is called the well spaced set. + + align:start position:0% +so this is called the well spaced set. + + + align:start position:0% +so this is called the well spaced set. +So I could fix a t. I can make a delta t + + align:start position:0% +So I could fix a t. I can make a delta t + + + align:start position:0% +So I could fix a t. I can make a delta t +well spaced. I can fix t and delta. I + + align:start position:0% +well spaced. I can fix t and delta. I + + + align:start position:0% +well spaced. I can fix t and delta. I +can make a delta t wellspace set or I + + align:start position:0% +can make a delta t wellspace set or I + + + align:start position:0% +can make a delta t wellspace set or I +can make a delta t alph4's regular set. + + align:start position:0% +can make a delta t alph4's regular set. + + + align:start position:0% +can make a delta t alph4's regular set. +And they look rather different from each + + align:start position:0% +And they look rather different from each + + + align:start position:0% +And they look rather different from each +other. And there's also a gray area in + + align:start position:0% +other. And there's also a gray area in + + + align:start position:0% +other. And there's also a gray area in +between. + + align:start position:0% +between. + + + align:start position:0% +between. +Um so this one is distinguished by + + align:start position:0% +Um so this one is distinguished by + + + align:start position:0% +Um so this one is distinguished by +saying that the points + + align:start position:0% +saying that the points + + + align:start position:0% +saying that the points +are the most separated. + + align:start position:0% + + + + align:start position:0% + +So if these points were like electrons + + align:start position:0% +So if these points were like electrons + + + align:start position:0% +So if these points were like electrons +that were sitting in this ball and they + + align:start position:0% +that were sitting in this ball and they + + + align:start position:0% +that were sitting in this ball and they +repel each other, they would come to a + + align:start position:0% +repel each other, they would come to a + + + align:start position:0% +repel each other, they would come to a +position that's sort of like this. It + + align:start position:0% +position that's sort of like this. It + + + align:start position:0% +position that's sort of like this. It +would be well spaced. + + align:start position:0% +would be well spaced. + + + align:start position:0% +would be well spaced. +And this one is distinguished by being + + align:start position:0% +And this one is distinguished by being + + + align:start position:0% +And this one is distinguished by being +this is the most clumped + + align:start position:0% +this is the most clumped + + + align:start position:0% +this is the most clumped +which is allowed + + align:start position:0% +which is allowed + + + align:start position:0% +which is allowed +for a delta t set. + + align:start position:0% +for a delta t set. + + + align:start position:0% +for a delta t set. +So this isn't the most clumped possible + + align:start position:0% +So this isn't the most clumped possible + + + align:start position:0% +So this isn't the most clumped possible +set. I could take these delta balls. I + + align:start position:0% +set. I could take these delta balls. I + + + align:start position:0% +set. I could take these delta balls. I +could smoosh them all there. That would + + align:start position:0% +could smoosh them all there. That would + + + align:start position:0% +could smoosh them all there. That would +be more clumped. But if it's a delta t + + align:start position:0% +be more clumped. But if it's a delta t + + + align:start position:0% +be more clumped. But if it's a delta t +set, it's not allowed to do that. And + + align:start position:0% +set, it's not allowed to do that. And + + + align:start position:0% +set, it's not allowed to do that. And +this is the most clumped that it could + + align:start position:0% +this is the most clumped that it could + + + align:start position:0% +this is the most clumped that it could +be. + + align:start position:0% +be. + + + align:start position:0% +be. +subject to the definition of a delta t + + align:start position:0% +subject to the definition of a delta t + + + align:start position:0% +subject to the definition of a delta t +sub. + + align:start position:0% + + + + align:start position:0% + +Okay, cool. So, + + align:start position:0% +Okay, cool. So, + + + align:start position:0% +Okay, cool. So, +so there's a range of spacing conditions + + align:start position:0% +so there's a range of spacing conditions + + + align:start position:0% +so there's a range of spacing conditions +um and and this hopefully gives a sample + + align:start position:0% +um and and this hopefully gives a sample + + + align:start position:0% +um and and this hopefully gives a sample +of Yeah. + + align:start position:0% +of Yeah. + + + align:start position:0% +of Yeah. +>> Is there some sort of like energy + + align:start position:0% +>> Is there some sort of like energy + + + align:start position:0% +>> Is there some sort of like energy +condition or kind of quantitative + + align:start position:0% +condition or kind of quantitative + + + align:start position:0% +condition or kind of quantitative +measure of the clumping that would kind + + align:start position:0% +measure of the clumping that would kind + + + align:start position:0% +measure of the clumping that would kind +of allow you to separate the two cases + + align:start position:0% +of allow you to separate the two cases + + + align:start position:0% +of allow you to separate the two cases +because they're both delta SC, + + align:start position:0% +because they're both delta SC, + + + align:start position:0% +because they're both delta SC, +>> right? So the question is there is there + + align:start position:0% +>> right? So the question is there is there + + + align:start position:0% +>> right? So the question is there is there +a quantitative measure of clumping or + + align:start position:0% +a quantitative measure of clumping or + + + align:start position:0% +a quantitative measure of clumping or +concentrating or spacing that would + + align:start position:0% +concentrating or spacing that would + + + align:start position:0% +concentrating or spacing that would +allow us to distinguish them? Um I I + + align:start position:0% +allow us to distinguish them? Um I I + + + align:start position:0% +allow us to distinguish them? Um I I +think the nicest way to do that is this + + align:start position:0% +think the nicest way to do that is this + + + align:start position:0% +think the nicest way to do that is this +list of RJS or perhaps this list of uh + + align:start position:0% +list of RJS or perhaps this list of uh + + + align:start position:0% +list of RJS or perhaps this list of uh +this list of these numbers here. Yeah. + + align:start position:0% +this list of these numbers here. Yeah. + + + align:start position:0% +this list of these numbers here. Yeah. +So it's not just a single number, but it + + align:start position:0% +So it's not just a single number, but it + + + align:start position:0% +So it's not just a single number, but it +is quantitative. And if you're willing + + align:start position:0% +is quantitative. And if you're willing + + + align:start position:0% +is quantitative. And if you're willing +to have, you know, like a a list of + + align:start position:0% +to have, you know, like a a list of + + + align:start position:0% +to have, you know, like a a list of +numbers describing your set, then it + + align:start position:0% +numbers describing your set, then it + + + align:start position:0% +numbers describing your set, then it +does quite a good job. + + align:start position:0% +does quite a good job. + + + align:start position:0% +does quite a good job. +Um, it's really a modern innovation to + + align:start position:0% +Um, it's really a modern innovation to + + + align:start position:0% +Um, it's really a modern innovation to +focus on that. In in previous times, + + align:start position:0% +focus on that. In in previous times, + + + align:start position:0% +focus on that. In in previous times, +people wanted to describe the spacing of + + align:start position:0% +people wanted to describe the spacing of + + + align:start position:0% +people wanted to describe the spacing of +their set with one number, which would + + align:start position:0% +their set with one number, which would + + + align:start position:0% +their set with one number, which would +be like the dimension of the set or the + + align:start position:0% +be like the dimension of the set or the + + + align:start position:0% +be like the dimension of the set or the +energy or something. Um, and when they + + align:start position:0% +energy or something. Um, and when they + + + align:start position:0% +energy or something. Um, and when they +were describing with just one number, + + align:start position:0% +were describing with just one number, + + + align:start position:0% +were describing with just one number, +then it was lumping together these two + + align:start position:0% +then it was lumping together these two + + + align:start position:0% +then it was lumping together these two +rather different behaviors. And it turns + + align:start position:0% +rather different behaviors. And it turns + + + align:start position:0% +rather different behaviors. And it turns +out to be important to unlump them um + + align:start position:0% +out to be important to unlump them um + + + align:start position:0% +out to be important to unlump them um +for to prove this theorem at least with + + align:start position:0% +for to prove this theorem at least with + + + align:start position:0% +for to prove this theorem at least with +the proof that we have. + + align:start position:0% + + + + align:start position:0% + +Okay, good. Uh, okay. So now I can write + + align:start position:0% +Okay, good. Uh, okay. So now I can write + + + align:start position:0% +Okay, good. Uh, okay. So now I can write +down the outline of the proof. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +so here is the outline of the proof of + + align:start position:0% +so here is the outline of the proof of + + + align:start position:0% +so here is the outline of the proof of +the main theorem or let me say of the + + align:start position:0% +the main theorem or let me say of the + + + align:start position:0% +the main theorem or let me say of the +first conjecture + + align:start position:0% + + + + align:start position:0% + +first. + + align:start position:0% + + + + align:start position:0% + +Okay, + + align:start position:0% +Okay, + + + align:start position:0% +Okay, +so first main ingredient + + align:start position:0% +so first main ingredient + + + align:start position:0% +so first main ingredient +is a theorem of Borpin and a Schwarin + + align:start position:0% +is a theorem of Borpin and a Schwarin + + + align:start position:0% +is a theorem of Borpin and a Schwarin +from 24 + + align:start position:0% +from 24 + + + align:start position:0% +from 24 +and they proved that the Fenberg + + align:start position:0% +and they proved that the Fenberg + + + align:start position:0% +and they proved that the Fenberg +conjecture holds in the ad regular case. + + align:start position:0% + + + + align:start position:0% + +Okay, so this is based on it builds on + + align:start position:0% +Okay, so this is based on it builds on + + + align:start position:0% +Okay, so this is based on it builds on +the stuff builds on the stuff we talked + + align:start position:0% +the stuff builds on the stuff we talked + + + align:start position:0% +the stuff builds on the stuff we talked +about today. So it builds on the + + align:start position:0% +about today. So it builds on the + + + align:start position:0% +about today. So it builds on the +continuum bec theorem of OSW which in + + align:start position:0% +continuum bec theorem of OSW which in + + + align:start position:0% +continuum bec theorem of OSW which in +turn built on the epsilon improvement + + align:start position:0% +turn built on the epsilon improvement + + + align:start position:0% +turn built on the epsilon improvement +of uh or OS which in turn built on the + + align:start position:0% +of uh or OS which in turn built on the + + + align:start position:0% +of uh or OS which in turn built on the +BAN projection theorem. + + align:start position:0% + + + + align:start position:0% + +All right, it's not at all obvious given + + align:start position:0% +All right, it's not at all obvious given + + + align:start position:0% +All right, it's not at all obvious given +the Beck theorem, just an ingredient. + + align:start position:0% +the Beck theorem, just an ingredient. + + + align:start position:0% +the Beck theorem, just an ingredient. +Um, and um, so there also some great + + align:start position:0% +Um, and um, so there also some great + + + align:start position:0% +Um, and um, so there also some great +ideas in that that we'll talk about next + + align:start position:0% +ideas in that that we'll talk about next + + + align:start position:0% +ideas in that that we'll talk about next +time. But also it involves some special + + align:start position:0% +time. But also it involves some special + + + align:start position:0% +time. But also it involves some special +structure + + align:start position:0% +structure + + + align:start position:0% +structure +of the AD regular case. + + align:start position:0% + + + + align:start position:0% + +Okay, we'll talk about that a lot uh on + + align:start position:0% +Okay, we'll talk about that a lot uh on + + + align:start position:0% +Okay, we'll talk about that a lot uh on +Thursday. + + align:start position:0% +Thursday. + + + align:start position:0% +Thursday. +All right, the second ingredient is a + + align:start position:0% +All right, the second ingredient is a + + + align:start position:0% +All right, the second ingredient is a +theorem of Guth Solomon Wong. So I was + + align:start position:0% +theorem of Guth Solomon Wong. So I was + + + align:start position:0% +theorem of Guth Solomon Wong. So I was +involved a little bit. This a slightly + + align:start position:0% +involved a little bit. This a slightly + + + align:start position:0% +involved a little bit. This a slightly +older theorem. It's from 2019 + + align:start position:0% +older theorem. It's from 2019 + + + align:start position:0% +older theorem. It's from 2019 +and we proved that the first invert + + align:start position:0% +and we proved that the first invert + + + align:start position:0% +and we proved that the first invert +conjecture holds in the well spaced + + align:start position:0% +conjecture holds in the well spaced + + + align:start position:0% +conjecture holds in the well spaced +case. + + align:start position:0% + + + + align:start position:0% + +Okay. And it's based on the forier + + align:start position:0% +Okay. And it's based on the forier + + + align:start position:0% +Okay. And it's based on the forier +method. + + align:start position:0% + + + + align:start position:0% + +Okay, this is much less difficult than + + align:start position:0% +Okay, this is much less difficult than + + + align:start position:0% +Okay, this is much less difficult than +this. It's the 4A method that we + + align:start position:0% +this. It's the 4A method that we + + + align:start position:0% +this. It's the 4A method that we +explored for a while with a little bit + + align:start position:0% +explored for a while with a little bit + + + align:start position:0% +explored for a while with a little bit +of extra something something. How do you + + align:start position:0% +of extra something something. How do you + + + align:start position:0% +of extra something something. How do you +take advantage of being really well + + align:start position:0% +take advantage of being really well + + + align:start position:0% +take advantage of being really well +spaced instead of just ad regular + + align:start position:0% +spaced instead of just ad regular + + + align:start position:0% +spaced instead of just ad regular +okay + + align:start position:0% +okay + + + align:start position:0% +okay +good. All right. So now um + + align:start position:0% + + + + align:start position:0% + +when I presented these two possibilities + + align:start position:0% +when I presented these two possibilities + + + align:start position:0% +when I presented these two possibilities +it the way I had thought about them is + + align:start position:0% +it the way I had thought about them is + + + align:start position:0% +it the way I had thought about them is +that these are just two opposite ends of + + align:start position:0% +that these are just two opposite ends of + + + align:start position:0% +that these are just two opposite ends of +a whole gray spectrum. + + align:start position:0% +a whole gray spectrum. + + + align:start position:0% +a whole gray spectrum. +And so if you have a method that works + + align:start position:0% +And so if you have a method that works + + + align:start position:0% +And so if you have a method that works +in one end and you have a method that + + align:start position:0% +in one end and you have a method that + + + align:start position:0% +in one end and you have a method that +works on the other end, + + align:start position:0% +works on the other end, + + + align:start position:0% +works on the other end, +I guess you might hope to have a general + + align:start position:0% +I guess you might hope to have a general + + + align:start position:0% +I guess you might hope to have a general +thing that sort of combines them both + + align:start position:0% +thing that sort of combines them both + + + align:start position:0% +thing that sort of combines them both +and and works for everything. But um but + + align:start position:0% +and and works for everything. But um but + + + align:start position:0% +and and works for everything. But um but +there's still all this stuff in the + + align:start position:0% +there's still all this stuff in the + + + align:start position:0% +there's still all this stuff in the +middle. + + align:start position:0% +middle. + + + align:start position:0% +middle. +Um and it turns out I think this is + + align:start position:0% +Um and it turns out I think this is + + + align:start position:0% +Um and it turns out I think this is +surprising and important in its own + + align:start position:0% +surprising and important in its own + + + align:start position:0% +surprising and important in its own +right that the proof of the theorem + + align:start position:0% +right that the proof of the theorem + + + align:start position:0% +right that the proof of the theorem +actually reduces to just those two cases + + align:start position:0% +actually reduces to just those two cases + + + align:start position:0% +actually reduces to just those two cases +or or um so the third ingredient + + align:start position:0% +or or um so the third ingredient + + + align:start position:0% +or or um so the third ingredient +is a multiscale argument + + align:start position:0% + + + + align:start position:0% + +which shows that the first conjecture + + align:start position:0% +which shows that the first conjecture + + + align:start position:0% +which shows that the first conjecture +actually reduces to + + align:start position:0% +actually reduces to + + + align:start position:0% +actually reduces to +the ad regular case and the what they + + align:start position:0% +the ad regular case and the what they + + + align:start position:0% +the ad regular case and the what they +call the semi wellspaced case. + + align:start position:0% +call the semi wellspaced case. + + + align:start position:0% +call the semi wellspaced case. +So this is a small generalization of + + align:start position:0% +So this is a small generalization of + + + align:start position:0% +So this is a small generalization of +this case that can be handled by more or + + align:start position:0% +this case that can be handled by more or + + + align:start position:0% +this case that can be handled by more or +less the same methods using for + + align:start position:0% +less the same methods using for + + + align:start position:0% +less the same methods using for +analysis. + + align:start position:0% + + + + align:start position:0% + +Okay. Um + + align:start position:0% +Okay. Um + + + align:start position:0% +Okay. Um +cool. + + align:start position:0% + + + + align:start position:0% + +Okay. So in in each of these I think + + align:start position:0% +Okay. So in in each of these I think + + + align:start position:0% +Okay. So in in each of these I think +there is something worth talking about + + align:start position:0% +there is something worth talking about + + + align:start position:0% +there is something worth talking about +and worth worth remembering an idea that + + align:start position:0% +and worth worth remembering an idea that + + + align:start position:0% +and worth worth remembering an idea that +could be useful in other in other pro + + align:start position:0% +could be useful in other in other pro + + + align:start position:0% +could be useful in other in other pro +certainly in other problems in this + + align:start position:0% +certainly in other problems in this + + + align:start position:0% +certainly in other problems in this +field and maybe in other parts of math. + + align:start position:0% +field and maybe in other parts of math. + + + align:start position:0% +field and maybe in other parts of math. +Uh we have two more classes so I'll + + align:start position:0% +Uh we have two more classes so I'll + + + align:start position:0% +Uh we have two more classes so I'll +vigil and wiggle and so my goal is in + + align:start position:0% +vigil and wiggle and so my goal is in + + + align:start position:0% +vigil and wiggle and so my goal is in +the two classes to say something + + align:start position:0% +the two classes to say something + + + align:start position:0% +the two classes to say something +substantial about each of these three + + align:start position:0% +substantial about each of these three + + + align:start position:0% +substantial about each of these three +ideas which fit together to prove the + + align:start position:0% +ideas which fit together to prove the + + + align:start position:0% +ideas which fit together to prove the +first and third conjecture. + + align:start position:0% + + + + align:start position:0% + +Okay, good. Any question la last + + align:start position:0% +Okay, good. Any question la last + + + align:start position:0% +Okay, good. Any question la last +questions or comments? + + align:start position:0% + + + + align:start position:0% + +>> Mhm. + + align:start position:0% +>> Mhm. + + + align:start position:0% +>> Mhm. +>> Within kind of each of these individual + + align:start position:0% +>> Within kind of each of these individual + + + align:start position:0% +>> Within kind of each of these individual +cases like how kind of much variation is + + align:start position:0% +cases like how kind of much variation is + + + align:start position:0% +cases like how kind of much variation is +there in the structure of the sets? Like + + align:start position:0% +there in the structure of the sets? Like + + + align:start position:0% +there in the structure of the sets? Like +I guess it's not going to be kind of + + align:start position:0% +I guess it's not going to be kind of + + + align:start position:0% +I guess it's not going to be kind of +rearranging kind of certain points + + align:start position:0% +rearranging kind of certain points + + + align:start position:0% +rearranging kind of certain points +within kind of one of the boxes does a + + align:start position:0% +within kind of one of the boxes does a + + + align:start position:0% +within kind of one of the boxes does a +lot or does a little + + align:start position:0% +lot or does a little + + + align:start position:0% +lot or does a little +Yeah. Okay. So the question is we've t + + align:start position:0% +Yeah. Okay. So the question is we've t + + + align:start position:0% +Yeah. Okay. So the question is we've t +so we've taken all the delta t sets we + + align:start position:0% +so we've taken all the delta t sets we + + + align:start position:0% +so we've taken all the delta t sets we +have then divided them according to + + align:start position:0% +have then divided them according to + + + align:start position:0% +have then divided them according to +their branching function and one extreme + + align:start position:0% +their branching function and one extreme + + + align:start position:0% +their branching function and one extreme +is the ad regular and one extreme is the + + align:start position:0% +is the ad regular and one extreme is the + + + align:start position:0% +is the ad regular and one extreme is the +wellspaced + + align:start position:0% +wellspaced + + + align:start position:0% +wellspaced +and then the question is if you look + + align:start position:0% +and then the question is if you look + + + align:start position:0% +and then the question is if you look +among different sets with the same + + align:start position:0% +among different sets with the same + + + align:start position:0% +among different sets with the same +branching function like among different + + align:start position:0% +branching function like among different + + + align:start position:0% +branching function like among different +ad regular sets how different are they + + align:start position:0% +ad regular sets how different are they + + + align:start position:0% +ad regular sets how different are they +from each other? Um + + align:start position:0% +from each other? Um + + + align:start position:0% +from each other? Um +well + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +uh I will try to sort of answer that by + + align:start position:0% +uh I will try to sort of answer that by + + + align:start position:0% +uh I will try to sort of answer that by +drawing a second ad regular set in blue + + align:start position:0% +drawing a second ad regular set in blue + + + align:start position:0% +drawing a second ad regular set in blue +that we can compare to the one in white. + + align:start position:0% +that we can compare to the one in white. + + + align:start position:0% +that we can compare to the one in white. +So I should pick four uh big squares and + + align:start position:0% +So I should pick four uh big squares and + + + align:start position:0% +So I should pick four uh big squares and +in each of them I'll draw four dots. + + align:start position:0% + + + + align:start position:0% + +Um + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +I would say that the sort of + + align:start position:0% +I would say that the sort of + + + align:start position:0% +I would say that the sort of +spacing feel of these dots is is the + + align:start position:0% +spacing feel of these dots is is the + + + align:start position:0% +spacing feel of these dots is is the +same in all the examples that are ad + + align:start position:0% +same in all the examples that are ad + + + align:start position:0% +same in all the examples that are ad +regular. Um on the other hand actually + + align:start position:0% +regular. Um on the other hand actually + + + align:start position:0% +regular. Um on the other hand actually +let me draw another example. So this + + align:start position:0% +let me draw another example. So this + + + align:start position:0% +let me draw another example. So this +this would be here's another example. + + align:start position:0% + + + + align:start position:0% + +So + + align:start position:0% + + + + align:start position:0% + +something else is a little different + + align:start position:0% +something else is a little different + + + align:start position:0% +something else is a little different +about this example. Um and so yeah, so + + align:start position:0% +about this example. Um and so yeah, so + + + align:start position:0% +about this example. Um and so yeah, so +there are some more delicate things that + + align:start position:0% +there are some more delicate things that + + + align:start position:0% +there are some more delicate things that +could be different about the different + + align:start position:0% +could be different about the different + + + align:start position:0% +could be different about the different +ad regular examples. Even though so so + + align:start position:0% +ad regular examples. Even though so so + + + align:start position:0% +ad regular examples. Even though so so +what's the same about them is you give + + align:start position:0% +what's the same about them is you give + + + align:start position:0% +what's the same about them is you give +me a radius your favorite radius you + + align:start position:0% +me a radius your favorite radius you + + + align:start position:0% +me a radius your favorite radius you +stick down a ball of that radius and + + align:start position:0% +stick down a ball of that radius and + + + align:start position:0% +stick down a ball of that radius and +count how many points are in there that + + align:start position:0% +count how many points are in there that + + + align:start position:0% +count how many points are in there that +will be the same for any a dregular set + + align:start position:0% + + + + align:start position:0% + +but there are delicate things actually + + align:start position:0% +but there are delicate things actually + + + align:start position:0% +but there are delicate things actually +another very important delicate thing + + align:start position:0% +another very important delicate thing + + + align:start position:0% +another very important delicate thing +that would be different is so for let's + + align:start position:0% +that would be different is so for let's + + + align:start position:0% +that would be different is so for let's +now think about the well spaced set an + + align:start position:0% +now think about the well spaced set an + + + align:start position:0% +now think about the well spaced set an +example of a well spaced set is an + + align:start position:0% +example of a well spaced set is an + + + align:start position:0% +example of a well spaced set is an +integer grid + + align:start position:0% + + + + align:start position:0% + +that has some special properties. It has + + align:start position:0% +that has some special properties. It has + + + align:start position:0% +that has some special properties. It has +like translation symmetry and stuff like + + align:start position:0% +like translation symmetry and stuff like + + + align:start position:0% +like translation symmetry and stuff like +that. A typical well spaced set will + + align:start position:0% +that. A typical well spaced set will + + + align:start position:0% +that. A typical well spaced set will +still have one point in each of these + + align:start position:0% +still have one point in each of these + + + align:start position:0% +still have one point in each of these +boxes, but it won't have additive + + align:start position:0% +boxes, but it won't have additive + + + align:start position:0% +boxes, but it won't have additive +structure. It won't have translation + + align:start position:0% +structure. It won't have translation + + + align:start position:0% +structure. It won't have translation +symmetry. It won't have and it won't + + align:start position:0% +symmetry. It won't have and it won't + + + align:start position:0% +symmetry. It won't have and it won't +have uh you know very many lines that go + + align:start position:0% +have uh you know very many lines that go + + + align:start position:0% +have uh you know very many lines that go +through many points. So those kinds of + + align:start position:0% +through many points. So those kinds of + + + align:start position:0% +through many points. So those kinds of +things are different among the different + + align:start position:0% +things are different among the different + + + align:start position:0% +things are different among the different +sets with the same spacing condition. + + align:start position:0% + + + + align:start position:0% + +Uh okay. Well, let's stop there for + + align:start position:0% +Uh okay. Well, let's stop there for + + + align:start position:0% +Uh okay. Well, let's stop there for +today and we'll talk more about these + + align:start position:0% +today and we'll talk more about these + + + align:start position:0% +today and we'll talk more about these +things on our last two classes. \ No newline at end of file diff --git a/hRHzPaDpgu0.txt b/hRHzPaDpgu0.txt new file mode 100644 index 0000000000000000000000000000000000000000..9cd46d3fc76b37da141bc60a63466e6752f9b3f7 --- /dev/null +++ b/hRHzPaDpgu0.txt @@ -0,0 +1,2900 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high-quality +educational resources for free. + +To make a donation, or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: Particles +in quantum mechanics. + +In particular, the ones that are +identical and non-interacting. + +So basically, we were focusing +on a type of Hamiltonian + +for a system of N +particles, which + +could be written as the sum of +contributions that correspond + +respectively to particle +1, particle 2, particle N. + +So essentially, a sum of +terms that are all the same. + +And one-particle +terms is sufficient + +because we don't +have interactions. + +So if we look at one of +these H's-- so one of these + +one-particle Hamiltonians, we +said that we could find some + +kind of basis for it. + +In particular, typically we +were interested in particles + +in the box. + +We would label them +with some wave number k. + +And there was an associated +one-particle energy, + +which for the case of +one-particle in box + +was h bar squared +k squared over 2m. + +But in general, for the +one-particle system, + +we can think of a ladder of +possible values of energies. + +So there will be some +k1, k2, k3, et cetera. + +They may be distributed in any +particular way corresponding + +to different energies. + +Basically, you +would have a number + +of possible states +for one particle. + +So for the case of the particle +in the box, the wave functions + +and coordinate space that we +had x, k were of the form e + +to the i k dot x divided +by square root of V. + +We allowed the energies where h +bar squared k squared over 2m. + +And this discretization +was because the values of k + +were multiples of 2 pi over +l with integers in the three + +different directions. + +Assuming periodic +boundary conditions + +or appropriate discretization +for closed boundary conditions, + +or whatever you have. + +So that's the +one-particle state. + +If the Hamiltonian +is of this form, + +it is clear that we can +multiply a bunch of these states + +and form another +eigenstate for HN. + +Those we were calling +product states. + +So you basically pick a +bunch of these k's and you + +multiply them. + +So you have k1, k2, kN. + +And essentially, that +would correspond, + +let's say, in coordinate +representation + +to taking a bunch of x's and +the corresponding k's and having + +a wave function of the form e to +the i k alp-- sum over alpha k + +alpha x alpha, and then +divided by V to the N over 2. + +So in this procedure, +what did we do? + +We had a number of possibilities +for the one-particle state. + +And in order to, let's say, +make a two-particle state, + +we would pick two of +these k's and multiply + +the corresponding +wave functions. + +If you had three particles, +we could pick another one. + +If you had four particles, +we could potentially + +pick a second one +twice, et cetera. + +So in general, +basically we would + +put N of these crosses on +these one-particle states + +that we've selected. + +Problem was that +this was not allowed + +by quantum mechanics +for identical particles. + +Because if we took one +of these wave functions + +and exchanged two of +the labels, x1 and x2, + +we could potentially get +a different wave function. + +And in quantum mechanics, we +said that the wave function + +has to be either symmetric or +anti-symmetric with respect + +to exchange of a +pair of particles. + +And also, whatever it implied +for repeating this exchange + +many times to look at all +possible permutations. + +So what we saw was that +product states are good + +as long as you +are thinking about + +distinguishable particles. + +But if you have +identical particles, + +you had to appropriately +symmetrize or anti-symmetrize + +these states. + +So what we ended up was +a wabe of, for example, + +symmetrizing things for +the case of fermions. + +So we could take a bunch +of these k-values again. + +And a fermionic, or +anti-symmetrized version, + +was then constructed by +summing over all permutations. + +And for N particle, there would +be N factorial permutations. + +Basically, doing a +permutation of all of these + +indices k1, k2, et cetera, +that we had selected for this. + +And for the case +of fermions, we had + +to multiply each +permutation with a sign that + +was plus for even permutations, +minus for odd permutations. + +And this would give +us N factorial terms. + +And the appropriate +normalization + +was 1 over square +root of N factorial. + +So this was for the +case of fermions. + +And this was actually minus. + +I should have put +in a minus here. + +And this would have +been minus to the P. + +For the case of +bosons, we basically + +dispensed with this factor +of minus 1 to the P. + +So we had a Pk. + +Now, the corresponding +normalization that we had here + +was slightly different. + +The point was that +if we were doing + +this computation for +the case of fermions, + +we could not allow +a state where there + +is a double occupation of one +of the one-particle state. + +Under exchange of +the particles that + +would correspond +to these k-values, + +I would get the same state back, +but the exchange would give me + +a minus 1 and it +would give me 0. + +So the fermionic wave function +that I have constructed + +here, appropriately +anti-symmetrized, + +exists only as long as +there are no repeats. + +Whereas, for the case of bosons, +I could put 2 over same place. + +I could put 3 somewhere else, +any number that I liked, + +and there would be +no problem with this. + +Except that the normalization +would be more complicated. + +And we saw that +appropriate normalization + +was a product over +k nk factorial. + +So this was for fermions. + +This is for bosons. + +And the two I can +submerge into one formula + +by writing a symmetrized +or anti-symmetrized state, + +respectively indicated by eta, +where we have eta is minus 1 + +for fermions and eta +is plus 1 for bosons, + +which is 1 over square +root of N factorial product + +over k nk factorials. + +And then the sum over all +N factorial permutations. + +This phase factor for fermions +and nothing for bosons + +of the appropriately +permuted set of k's. + +And in this way +of noting things, + +I have to assign values nk which +are either 0 or 1 for fermions. + +Because as we said, multiple +occupations are not allowed. + +But there is no +restriction for bosons. + +Except of course, that +in this perspective, + +as I go along this k-axis, +I have 0, 1, 0, 2, 1, 3, 0, + +0 for the occupations. + +Of course, what I +need to construct + +whether I am dealing +with bosons or fermions + +is that the sum over k nk is +the total number of particles + +that I have. + +Now, the other thing to note +is that once I have given you + +a picture such as this in terms +of which one-particle states + +I want to look at, or which +set of occupation numbers + +I have nk, then +there is one and only + +one symmetrized or +anti-symmetrized state. + +So over here, I +could have permuted + +the k's in a number +of possible ways. + +But as a result +of symmetrization, + +anti-symmetrization, +various ways + +of permuting the +labels here ultimately + +come to the same set +of occupation numbers. + +So it is possible to actually +label the state rather than + +by the set of k's. + +By the set of nk's. + +It is kind of a more appropriate +way of representing the system. + +So that's essentially +the kinds of states + +that we are going to be using. + +Again, in talking about +identical particles, + +which could be either +bosons or fermions. + +Let's take a step back, +remind you of something + +that we did before that +had only one particle. + +Because I will soon +go to many particles. + +But before that, +let's remind you + +what the one particle +in a box looked like. + +So indeed, in this case, +the single-particle states + +were the ones that +I told you before, + +2 pi over l some +set of integers. + +Epsilon k, that was h bar +squared k squared over 2m. + +If I want to calculate +the partition function + +for one particle in the box, +I have to do a trace of e + +to the minus beta +h for one particle. + +The trace I can very +easily calculate + +in the basis in which +this is diagonal. + +That's the basis +that is parameterized + +by these k-values. + +So I do a sum over k of +e to the minus beta h + +bar squared k squared over 2m. + +And then in the limit +of very large box, + +we saw that the sum +over k I can replace + +with V integral +over k 2 pi cubed. + +This was the density +of states in k. + +e to the minus beta h bar +squared k squared over 2m. + +And this was three +Gaussian integrals + +that gave us the usual formula +of V over lambda cubed, where + +lambda was this thermal +[INAUDIBLE] wavelength + +h root 2 pi mk. + +But we said that the essence +of statistical mechanics + +is to tell you +about probabilities + +of various micro-states, various +positions of the particle + +in the box, which in +the quantum perspective + +is probability becomes +a density matrix. + +And we evaluated +this density matrix + +in the coordinate +representation. + +And in the coordinate +representation, + +essentially what +we had to do was + +to go into the basis in +which rho is diagonal. + +So we had x prime k. + +In the k basis, the density +matrix is just this formula. + +It's the Boltzmann weight +appropriately normalized by Z1. + +And then we go kx. + +And basically, +again replacing this + +with V integral d cubed k 2 pi +cubed e to the minus beta h bar + +squared k squared over 2m. + +These two factors of xk and x +prime k gave us a factor of e + +to the kx, xk I have as +ik dot x prime minus x. + +Completing the square. + +Actually, I had to divide by Z1. + +There is a factor of 1 over +V from the normalization + +of these things. + +The two V's here cancel, +but Z1 is proportional to V. + +The lambda cubes +cancel and so what + +we have is 1 over +V e to the minus x + +minus x prime squared +pi over lambda squared. + +So basically, what +you have here is + +that we have a box +of volume V. There + +is a particle inside +at some location x. + +And the probability +to find it at location + +x is the diagonal +element of this entity. + +It's just 1 over +V. But this entity + +has off-diagonal elements +reflecting the fact + +that the best that you can do +to localize something in quantum + +mechanics is to make some +kind of a wave packet. + +OK. + +So this we did last time. + +What we want to do now is +to go from one particle + +to the case of N particles. + +So rather than +having 1x prime, I + +will have a whole bunch of x +primes labeled 1 through N. + +And I want to calculate the N +particle density matrix that + +connects me from set of points +x to another set of points + +x prime. + +So if you like in +the previous picture, + +this would have been +x1 and x1 prime, + +and then I now have x2 and x2 +prime, x3 and x3 prime, xN and + +xN prime. + +I have a bunch of +different coordinates + +and I'd like to calculate that. + +OK. + +Once more, we know that rho +is diagonal in the basis that + +is represented by +these occupations + +of one-particle states. + +And so what I can +do is I can sum over + +a whole bunch of plane waves. + +And I have to pick N factors +of k out of this list + +in order to make one of these +symmetrized or anti-symmetrized + +wave functions. + +But then I have to +remember, as I said, + +that I should not over-count +distinct set of k-values + +because permutations +of these list of k's + +that I have over here, +because of symmetrization + +or anti-symmetrization, +will give me the same state. + +So I have to be +careful about that. + +Then, I go from x prime to k. + +Now, the density matrix +in the k-basis I know. + +It is simply e to the minus +beta, the energy which + +is sum over alpha h bar squared +k alpha squared over 2m. + +So I sum over the +list of k alphas + +that appear in this series. + +There will be n of them. + +I have to +appropriately normalize + +that by the N-particle partition +function, which we have yet + +to calculate. + +And then I go back from k to x. + +Now, let's do this. + +The first thing that +I mentioned last time + +is that I would, +in principle, like + +to sum over k1 going +over the entire list, + +k2 going the entire list, k3 +going over the entire list. + +That is, I would like to make +the sum over k's unrestricted. + +But then I have to +take into account + +the over-counting that I have. + +If I am looking at the case +where all of the k's are + +distinct-- they don't show +any double occupancy-- then + +I have over-counted by the +number of permutations. + +Because any permutation would +have given me the same number. + +So I have to divide by +the number of permutations + +to avoid the over-counting +due to symmetrization here. + +Now, when I have +something like this, + +which is a multiple occupancy, +I have overdone this division. + +I have to multiply +by this factor, + +and that's the correct number +of over-countings that I have. + +And as I said, this was a good +thing because the quantity + +that I had the hardest +time for, and comes + +in the normalizations +that occurs here, + +is this factor of 1 +over nk factorial. + +Naturally, again, +all of these things + +do depend on the symmetry. + +So I better make sure +I indicate the index. + +Whether I'm calculating this +density matrix for fermions + +or bosons, it is important. + +In either case-- well, +what I need to do + +is to do a summation over P +here for this one and P prime + +here or P prime here and P here. + +It doesn't matter, there's +two sets of permutations + +that I have to do. + +In each case, I have to +take care of this eta P, + +eta P prime. + +And then the normalization. + +So I divide by twice, or the +square of the square root. + +I get the N factorial +product over k nk factorial. + +And very nicely, the +over-counting factor + +here cancels the +normalization factor + +that I would have had here. + +So we got that. + +Now, what do we have? + +We have P prime permutation +of these objects going to x, + +and then we have +here P permutation + +of these k numbers going to x. + +I guess the first +one I got wrong. + +I start with x prime. + +Go through P prime to k. + +And again, symmetries are +already taken into account. + +I don't need to write that. + +And I have the factor +of e to the minus beta h + +bar squared sum over +alpha k alpha squared + +over 2m divided by ZN. + +OK, so let's bring all of the +denominator factors out front. + +I have a ZN. + +I have an N factorial squared. + +Two factors of N factorial. + +I have a sum over two sets of +permutations P and P prime. + +The product of the associated +phase factor of their parities, + +and then I have this +integration over k's. + +Now, unrestricted. + +Since it is unrestricted, I +can integrate independently + +over each one of the k's, or +sum over each one of them. + +When I sum, the sum +becomes the integral + +over d cubed k alpha divided +by 2 pi-- yeah, 2 pi cubed V. + +Basically, the density in +replacing the sum over k + +alpha with the +corresponding integration. + +So basically, this +set of factors + +is what happened to that. + +OK, what do we have here? + +We have e to the i x-- +well, let's be careful here. + +I have e to the i x prime alpha +acting on k of p prime alpha + +because I permuted +the k-label that + +went with, say, the alpha +component here with p prime. + +From here, I would +have minus because it's + +the complex conjugate. + +I have x alpha k p alpha, +because I permuted this by k. + +I have one of these factors for +each V. With each one of them, + +there is a normalization +of square root of V. + +So the two of them together will +give me V. But that's only one + +of the N-particle So +there are N of them. + +So if I want, I can +extend this product + +to also encompass this term. + +And then having done so, I can +also write here e to the minus + +beta h bar squared +k alpha squared + +over 2m within the product. + +AUDIENCE: [INAUDIBLE] after +this-- is it quantity xk minus + +[INAUDIBLE]. + +PROFESSOR: I forgot an a here. + +What else did I miss out? + +AUDIENCE: [INAUDIBLE] quantity. + +PROFESSOR: So I forgot the i. + +OK, good? + +So the V's cancel out. + +All right, so that's fine. + +What do we have? + +We have 1 over ZN N +factorial squared. + +Two sets of permutations +summed over, p and p prime. + +Corresponding parities +eta p eta of p prime. + +And then, I have a product +of these integrations + +that I have to do that are +three-dimensional Gaussians + +for each k alpha. + +What do I get? + +Well, first of all, +if I didn't have this, + +if I just was doing +the integration of e + +to the minus beta h bar +squared k squared over 2m, + +I did that already. + +I get a 1 over lambda cubed. + +So basically, from each +one of them I will get a 1 + +over lambda cubed. + +But the integration is +shifted by this amount. + +Actually, I already did the +shifted integration here also + +for one particle. + +So I get the corresponding +factor of e to the minus-- ah. + +I have to be a little +bit careful over here + +because what I am integrating +is over k alpha squared. + +Whereas, in the way that +I have the list over here, + +I have x prime +alpha and x alpha, + +but a different k +playing around with each. + +What should I do? + +I really want this +integration over k + +alpha to look like +what I have over here. + +Well, as I sum over +all possibilities + +in each one of these terms, I +am bound to encounter k alpha. + +Essentially, I have permuted +all of the k's that I originally + +had. + +So the k alpha has now been +sent to some other location. + +But as I sum over all possible +alpha, I will hit that. + +When I hit that, I will +find that the thing that + +was multiplying k alpha is the +inverse permutation of alpha. + +And the thing that was +multiplying k alpha here + +is the inverse permutation of p. + +So then I can do the +integration over k alpha easily. + +And so what do I have? + +I have x prime of +p prime inverse + +alpha-- the inverse +permutation-- minus x + +of p inverse alpha squared +pi over lambda squared. + +Now, this is still +inconvenient because I + +am summing over two N +factorial sets of permutations. + +And I expect that since +the sum only involves + +comparison of things that +are occurring N times, + +as I go over the list of N +factorial permutation squared, + +I will get the same +thing appearing twice. + +So it is very much like when we +are doing an integration over x + +and x prime, but +the function only + +depends on x minus x prime. + +We get a factor of volume. + +Here, it is easy to +see that one of these + +sums I can very easily do +because it is just repetition + +of all of the results +that I have previously. + +And there will be N +factorial such terms. + +So doing that, I can get rid +of one of the N factorials. + +And I will have only +one permutation left, + +Q. And what will appear here +would be the parity of this Q + +that is the combination, +or if you like, + +the relative of these +two permutations. + +And I have an +exponential of minus sum + +over alpha x alpha minus +x prime Q alpha squared + +pi over lambda squared. + +And I think I forgot a factor +of lambda to the 3 [INAUDIBLE]. + +This factor of lambda 3. + +So this is actually +the final result. + +And let's see what +that precisely + +means for two particles. + +So let's look at two particles. + +So for two particle,s I will +have on one side coordinates + +of 1 prime and 2 prime. + +On the right-hand side, I +have coordinates 1 and 2. + +And let's see what this +density matrix tells us. + +It tells us that to go from x1 +prime x2 prime, a two particle + +density matrix connecting +to x1 x2 on the other side, + +I have 1 over the two-particle +partition function + +that i haven't yet calculated. + +Lambda to the sixth. + +N factorial in this case is 2. + +And then for two things, +there are two permutations. + +So the identity +maps 1 to 1, 2 to 2. + +And therefore, what +I will get here + +would be exponential of minus +x1' minus x1 prime squared + +pi over lambda squared minus +x2 minus x2 prime squared pi + +over lambda squared. + +So that's Q being +identity and identity + +has essentially 0 parity. + +It's an even permutation. + +The next thing is when +I exchange 1 and 2. + +That would have odd parity. + +So I would get minus 1 for +fermions, plus for bosons. + +And what I would get here +is exponential of minus x1' + +minus x2 prime squared pi +over lambda squared minus x2 + +minus x1 prime squared +pi over lambda squared. + +So essentially, one of +the terms-- the first term + +is just the square of what I +had before for one particle. + +I take the one-particle result, +going from 1 to 1 prime, + +going from 2 to 2 prime +and multiply them together. + +But then you say, I can't tell +apart 2 prime and 1 prime. + +Maybe the thing that +you are calling 1 prime + +is really 2 prime +and vice versa. + +So I have to allow +for the possibility + +that rather than +x1 prime here, I + +should put x2 prime and +the other way around. + +And this also corresponds +to a permutation + +that is an exchange. + +It's an odd parity and will +give you something like that. + +Say OK, I have no +idea what that means. + +I'll tell you, OK, you were +happy when I put x prime and x + +here because that +was the probability + +to find the particle somewhere. + +So let me look at +the diagonal term + +here, which is a probability. + +This should give +me the probability + +to find one particle +at position x1, + +one particle at position x2. + +Because the particles +were non-interacting, + +one particle-- it +could be anywhere. + +I had the 1 over V. +Is it 1 over V squared + +or something like that? + +Well, we find that +there is factor + +out front that we +haven't yet evaluated. + +It turns out that this +factor will give me a 1 + +over V squared. + +And if I set x1 +prime to x1, x2 prime + +to x2, which is what I've done +here, this factor becomes 1. + +But then the other factor will +give me eta e to the minus 2 + +pi over lambda squared +x1 minus x2 squared. + +So the physical probability +to find one particle-- or more + +correctly, a wave packet +here and a wave package there + +is not 1 over V squared. + +It's some function of the +separation between these two + +particles. + +So that separation +is contained here. + +If I really call that +separation to be r, + +this is an additional +weight that depends on r. + +This is r squared. + +So you can think of this +as an interaction, which + +is because solely of +quantum statistics. + +And what is this interaction? + +This interaction V of r +would be minus kT log of 1 + +plus eta e to the minus 2 pi +r squared over lambda squared. + +I will plot out for you +what this V or r looks + +like as a function of how far +apart the centers of these two + +wave packets are. + +You can see that the +result depends on eta. + +If eta is minus 1, which is +for the case of fermions, + +this is 1 minus something. + +It's something that +is less than 1. + +[INAUDIBLE] would be negative. + +So the whole potential would +be positive, or repulsive. + +At large distances, indeed it +would be exponentially going + +to 0 because I can expand +the log at large distances. + +So here I have a term +that is minus 2 pi + +r squared over lambda squared. + +As I go towards r equals +to 0, actually things + +become very bad because r +goes to 0 I will get 1 minus 1 + +and the log will diverge. + +So basically, there is, if you +like, an effective potential + +that says you +can't put these two + +fermions on top of each other. + +So there is a +statistical potential. + +So this is for eta +minus 1, or fermions. + +For the case of +bosons, eta plus 1. + +It is log of 1 plus +something, so it's + +a positive number +inside the log. + +The potential will +be attractive. + +And it will actually saturate +to a value of kT log 2 + +when r goes to 0. + +So this is again, eta of plus +1 for the case of bosons. + +So the one thing that this +formula does not have yet + +is the value for this +partition function ZN. + +It gives you the qualitative +behavior in either case. + +And let's calculate what ZN is. + +Well, basically, that +would come from noting + +that the trace of +rho has to be 1. + +So ZN is trace of e +to the minus beta H. + +And essentially, I can take +this ZN to the other side + +and evaluate this as x +e to the minus beta H x. + +That is, I can calculate +the diagonal elements + +of this matrix that +I have calculated-- + +that I have over there. + +So there is an +overall factor of 1 + +over lambda cubed to the power +of N. I have N factorial. + +And then I have a sum over +permutations Q eta of Q. + +The diagonal element +is obtained by putting + +x prime to be the same as x. + +So I have exponential of minus +x-- sum over alpha x alpha + +minus x of Q alpha. + +I set x prime to +be the same as x. + +Squared. + +And then there's an overall +pi over lambda squared. + +And if I am taking the trace, +it means that I have to do + +integration over all x's. + +So I'm evaluating this trace +in coordinate basis, which + +means that I should +put x and x prime to be + +the same for the +trace, and then I + +have to sum or integrate over +all possible values of x. + +So let's do this. + +I have 1 over N factorial lambda +cubed raised to the power of N. + +OK. + +Now I have to make +a choice because I + +have a whole bunch of terms +because of these permutations. + +Let's do them one by one. + +Let's first do the case +where Q is identity. + +That is, I map +everybody to themselves. + +Actually, let me write down +the integrations first. + +I will do the integrations +over all pairs + +of coordinates of +these Gaussians. + +These Gaussians I will evaluate +for different permutations. + +Let's look at the case +where Q is identity. + +When Q is identity, essentially +I will put all of the x prime + +to be the same as x. + +It is like what I did here +for two particles and I got 1. + +I do the same thing for +more than one particle. + +I will still get 1. + +Then, I will do the same +thing that I did over here. + +Here, the next term that I +did was to exchange 1 and 2. + +So this became x1 minus x2. + +I'll do the same thing here. + +I look at the case +where Q corresponds + +to exchange of +particles 1 and 2. + +And then that will +give me a factor which + +is e to the minus pi over lambda +squared x1 minus x2 squared. + +There are two of these making +together 2 pi over lambda + +squared, which I hope +I had there, too. + +But then there was a whole bunch +of other terms that I can do. + +I can exchange, +let's say, 7 and 9. + +And then I will get +here 2 pi over lambda + +squared x7 minus x9 squared. + +And there's a whole +bunch of such exchanges + +that I can make in +which I just switch + +between two particles +in this whole story. + +And clearly, the number of +exchanges that I can make + +is the number of pairs, +N N minus 1 over 2. + +Once I am done with +all of the exchanges, + +then I have to go to +the next thing that + +doesn't have an analog +here for two particles. + +But if I take three +particles, I can permute them + +like a triangle. + +So presumably there +would be next set + +of terms, which is a permutation +that is like 1, 2, 3, 2, 3, 1. + +There's a bunch of things that +involve two permutations, four + +permutations, and so forth. + +So there is a whole +list of things + +that would go to here where +these two-particle exchanges + +are the simplest class. + +Now, as we shall see, +there is a systematic way + +of looking at things where +the two-particle exchanges are + +the first correction +due to quantum effects. + +Three-particle exchanges would +be higher-order corrections. + +And we can systematically +do them in order. + +So let's see what happens if +we compare the case where there + +is no exchange and the case +where there is one exchange. + +When there is no +exchange, I am essentially + +integrating over each +position over the volume. + +So what I would get is V +raised to the power of N. + +The next term? + +Well, I have to do +the integrations. + +The integrations over x3, x4, +x5, all the way to x to the N, + +there is no factors. + +So they will give me factors +of V. And there are N minus 2 + +of them. + +And then I have to do the +integration over x1 and x2 + +of this factor, but +it's only a function + +of the relative coordinate. + +So there is one +other integration + +that I can trivially do, which +is the center of mass gives me + +a factor of V. +And then I am left + +with the integral over the +relative coordinate of e + +to the minus 2 pi r squared +over lambda squared. + +And I forgot-- it's +very important. + +This will carry a factor of eta +because any exchange is odd. + +And so there will be +a factor of eta here. + +And I said that I would +get the same expression + +for any of my N N minus +1 over 2 exchanges. + +So the result of all of +these exchange calculations + +would be the same thing. + +And then there would +be the contribution + +from three-body +exchange and so forth. + +So let's re-organize this. + +I can pull out the factor +of V to the N outside. + +So I would have V over lambda +cubed to the power of N. + +So the first term is 1. + +The next term has +the parity factor + +that distinguishes +bosons and fermions, goes + +with a multiplicity of pairs +which is N N minus 1 over 2. + +Since I already pulled +out a factor of V to the N + +and I really had V to +the N minus 1 here, + +I better put a factor +of 1 over V here. + +And then I just am +left with having + +to evaluate these +Gaussian integrals. + +Each Gaussian +integral will give me + +2 pi times the +variance, which is + +lambda squared divided by 2 pi. + +And then there's +actually a factor of 2. + +And there are three of +them, so I will have 3/2. + +So what I get here is lambda +cubed divided by 2 to the 3/2. + +Now, you can see that +any time I go further + +in this series of +exchanges, I will + +have more of these +Gaussian factors. + +And whenever I have +a Gaussian factor, + +I have an additional +integration to do + +that has an x minus +something squared in it. + +I will lose a factor of V. I +don't have that factor of V. + +And so subsequent terms will +be even smaller in powers of V. + +And presumably, compensated by +corresponding factors of lambda + +squared-- lambda cubed. + +Now, first thing to note is +that in the very, very high + +temperature limit, +lambda goes to 0. + +So I can forget even +this correction. + +What do I get? + +I get 1 over N factorial V over +lambda cubed to the power of N. + +Remember that many, many +lectures back we introduced + +by hand the factor of 1 over +N factorial for measuring + +phase spaces of +identical particles. + +And I promise to you +that we would get it + +when we did identical +particles in quantum mechanics, + +so here it is. + +So automatically, we +did the calculation, + +keeping track of +identity of particles + +at the level of quantum states. + +Went through the calculation and +in the high temperature limit, + +we get this 1 over N +factorial emerging. + +Secondly, we see that the +corrections to ideal gas + +behavior emerge as a series in +powers of lambda cubed over V. + +And for example, if I were to +take the log of the partition + +function, I would +get log of what + +I would have had classically, +which is this V over lambda + +cubed to the power of N +divided by N factorial. + +And then the log +of this expression. + +And this I'm going to +replace with N squared. + +There is not that +much difference. + +And since I'm regarding this +as a correction, log of 1 + +plus something, I will +replace with the something + +eta N squared 2V lambda cubed +2 to the 3/2 plus higher order. + +What does this mean? + +Once we have the +partition function, + +we can calculate pressure. + +Reminding you that beta +p was the log Z by dV. + +The first part is +the ideal gas that we + +had looked at classically. + +So once I go to the appropriate +large-end limit of this, + +what this gives me is +the density n over V. + +And then when I look +at the derivative here, + +the derivative of 1/V will give +me a minus 1 over V squared. + +So I will get minus eta. + +N over V, the whole +thing squared. + +So I will have n squared +lambda cubed 2 to the 5/2, + +and so forth. + +So I see that the +pressure of this ideal gas + +with no interactions +is already different + +from the classical result +that we had calculated + +by a factor that actually +reflects the statistics. + +For fermions eta of minus 1, +you get an additional pressure + +because of the kind of repulsion +that we have over here. + +Whereas, for bosons +you get an attraction. + +You can see that also the +thing that determines this-- + +so basically, this +corresponds to a second Virial + +coefficient, which is minus +eta lambda cubed 2 to the 5/2, + +is the volume of +these wave packets. + +So essentially, +the corrections are + +of the order of n +lambda cubed that + +is within one of these wave +packets how many particles + +you will encounter. + +As you go to high temperature, +the wave packets shrink. + +As you go to low temperature, +the wave packets expand. + +If you like, the interactions +become more important + +and you get corrections +to ideal gas wave. + +AUDIENCE: You assume that +we can use perturbation, + +but the higher terms actually +had a factor [INAUDIBLE]. + +And you can't really use +perturbation in that. + +PROFESSOR: OK. + +So what you are worried +about is the story here, + +that I took log of 1 +plus something here + +and I'm interested in the +limit of n going to infinity, + +that finite density n over +V. So already in that limit, + +you would say that +this factor really + +is overwhelmingly +larger than that. + +And as you say, the next +factor will be even larger. + +So what is the justification +in all of this? + +We have already encountered +this same problem + +when we were doing +these perturbations + +due to interactions. + +And the answer is that what +you really want to ensure + +is that not log Z, +but Z has a form + +that is e to the N something. + +And that something +will have corrections, + +potentially that are powers +of N, the density, which + +is N over V. And if you try to +force it into a perturbation + +series such as this, naturally +things like this happen. + +What does that really mean? + +That really means that the +correct thing that you should + +be expanding is, +indeed, log Z. If you + +were to do the kind of +hand-waving that I did here + +and do the expansion for Z, if +you also try to do it over here + +you will generate +terms that look + +kind of at the wrong order. + +But higher order terms +that you would get + +would naturally conspire so +that when you evaluate log Z, + +they come out right. + +You have to do this correctly. + +And once you have +done it correctly, + +then you can rely +on the calculation + +that you did before +as an example. + +And we did it correctly when +we were doing these cluster + +expansions and the +corresponding calculation we + +did for Q. We saw how the +different diagrams were + +appearing in both +Q and the log Q, + +and how they could be +summed over in log Q. + +But indeed, this +mathematically looks awkward + +and I kind of jumped a +step in writing log of 1 + +plus something that is huge +as if it was a small number. + +All right. + +So we have a problem. + +We want to calculate +the simplest + +system, which is the ideal gas. + +So classically, we did +all of our calculations + +first for the ideal gas. + +We had exact results. + +Then, let's say we +had interactions. + +We did perturbations around +that and all of that. + +And we saw that having to do +things for interacting systems + +is very difficult. + +Now, when we start to do +calculations for the quantum + +problem, at least in the way +that I set it up for you, + +it seems that quantum +problems are inherently + +interacting problems. + +I showed you that even at +the level of two particles, + +it is like having an interaction +between bosons and fermions. + +For three particles, +it becomes even worse + +because it's not only the +two-particle interaction. + +Because of the +three-particle exchanges, + +you would get an additional +three-particle interaction, + +four-particle interaction, +all of these things emerge. + +So really, if you +want to look at this + +from the perspective of +a partition function, + +we already see that +the exchange term + +involved having to +do a calculation that + +is equivalent to calculating +the second Virial + +coefficient for an +interacting system. + +The next one, for the +third Virial coefficient, + +I would need to look at +the three-body exchanges, + +kind of like the point +clusters, four-point clusters, + +all kinds of other +things are there. + +So is there any hope? + +And the answer is that it is +all a matter of perspective. + +And somehow it is true +that these particles + +in quantum mechanics +because of the statistics + +are subject to all kinds of +complicated interactions. + +But also, the +underlying Hamiltonian + +is simple and non-interacting. + +We can enumerate all +of the wave functions. + +Everything is simple. + +So by looking at things +in the right basis, + +we should be able to calculate +everything that we need. + +So here, I was kind of looking +at calculating the partition + +function in the coordinate +basis, which is the worst case + +scenario because the Hamiltonian +is diagonal in the momentum + +basis. + +So let's calculate ZN trace +of e to the minus beta H + +in the basis in +which H is diagonal. + +So what are the eigenvalues +and eigenfunctions? + +Well, the eigenfunctions are +the symmetrized/anti-symmetrized + +quantities. + +The eigenvalues are simply +e to the minus beta H + +bar squared k alpha +squared over 2m. + +So this is basically +the thing that I + +could write as the set +of k's appropriately + +symmetrized or anti-symmetrized +e to the minus beta + +sum over alpha H bar squared +k alpha squared over 2m k eta. + +Actually, I'm going to-- rather +than go through this procedure + +that we have up there +in which I wrote + +these, what I need to do +here is a sum over all k + +in order to evaluate the trace. + +So this is inherently a +sum over all sets of k's. + +But this sum is +restricted, just like what + +I had indicated for you before. + +Rather than trying +to do it that way, + +I note that these +k's I could also + +write in terms of these +occupation numbers. + +So equivalently, +my basis would be + +the set of occupation +numbers times the energy. + +The energy is then e to the +minus beta sum over k epsilon k + +nk, where epsilon +k is this beta H + +bar squared k alpha +squared over 2m. + +But I could do this in +principle for any epsilon k + +that I have over here. + +So the result that I am writing +for you is more general. + +Then I sandwich it +again, since I'm + +calculating the trace, +with the same state. + +Now, the states have +this restriction + +that I have over there. + +That is, for the case of +fermions, my nk can be 0 or 1. + +But there is no restriction +for nk on the bosons. + +Except, of course, that there +is this overall restriction + +that the sum over +k nk has to be N + +because I am looking +at N-particle states. + +Actually, I can remove +this because in this basis, + +e to the minus +beta H is diagonal. + +So I can, basically, +remove these entities. + +And I'm just summing a +bunch of exponentials. + +So that is good because I +should be able to do for each nk + +a sum of e to something nk. + +Well, the problem is this +that I can't sum over + +each nk independently. + +Essentially in the picture +that I have over here, + +I have some n1 here. + +I have some n2 here. + +Some n3 here, which are +the occupation numbers + +of these things. + +And for that +partition function, I + +have to do the sum of +these exponentials e + +to the minus epsilon 1 n1, +e to the minus epsilon 2 n2. + +But the sum of all of these +n's is kind of maxed out by N. + +I cannot independently sum +over them going over the entire + +range. + +But we've seen previously +how those constraints can + +be removed in +statistical mechanics. + +So our usual trick. + +We go to the ensemble in +which n can take any value. + +So we go to the grand +canonical prescription. + +We remove this constraint on n +by evaluating a grand partition + +function Q, which is a sum over +all N of e to the beta mu N ZN. + +So we do, essentially, +a Laplace transform. + +We exchange our n with +the chemical potential mu. + +Then, this constraint no +longer we need to worry about. + +So now I can sum over all +of the nk's without worrying + +about any constraint, provided +that I multiply with e + +to the beta mu n, which +is a sum over k nk. + +And then, the factor +that I have here, + +which is e to the minus beta +sum over k epsilon of k nk. + +So essentially for each +k, I can independently + +sum over its nk of e to the +beta mu minus epsilon of k nk. + +Now, the symmetry issues remain. + +This answer still +depends on whether or not + +I am calculating things +for bosons or fermions + +because these sums are +differently constrained + +whether I'm dealing +with fermions. + +In which case, nk +is only 0 or 1. + +Or bosons, in which case +there is no constraint. + +So what do I get? + +For the case of fermions, +I have a Q minus, + +which is product over all k. + +And for each k, the nk +takes either 0 or 1. + +So if it takes 0, I will +write e to the 0, which is 1. + +Or it takes 1. + +It is e to the beta +mu minus epsilon of k. + +For the case of bosons, +I have a Q plus. + +Q plus is, again, a product +over Q. In this case, + +nk going from 0 to infinity, I +am summing a geometric series + +that starts as 1, and +then the subsequent terms + +are smaller by a factor of +beta mu minus epsilon of k. + +Actually, for future +reference note + +that I would be able to +do this geometric sum + +provided that this combination +beta mu minus epsilon of k + +is negative. + +So that the subsequent terms +in this series are decaying. + +Typically, we would be +interested in things + +like partition functions, +grand partition functions. + +So we have something like log of +Q, which would be a sum over k. + +And I would have either +the log of this quantity + +or the log of this +quantity with a minus sign. + +I can combine the +two results together + +by putting a factor of minus +eta because in taking the log, + +over here for the bosons I +would pick a factor of minus 1 + +because the thing is +in the denominator. + +And then I would +write the log of 1. + +And then I have in both +cases, a factor which + +is e to the beta mu +minus epsilon of k. + +But occurring with +different signs + +for the bosons and +fermions, which again I + +can combine into a single +expression by putting a minus + +eta here. + +So this is a general +result for any Hamiltonian + +that has the characteristic +that we wrote over here. + +So this does not have to +be particles in a box. + +It could be particles in +a harmonic oscillator. + +These could be energy levels +of a harmonic oscillator. + +All you need to do is to +make the appropriate sum + +over the one-particle +levels harmonic oscillator, + +or whatever else you have, +of these factors that + +depend on the +individual energy levels + +of the one-particle system. + +Now, one of the things +that we will encounter + +having made this transition +from canonical, where we knew + +how many particles we had, to +grand canonical, where we only + +know the chemical potential, +is that we would ultimately + +want to express things in terms +of the number of particles. + +So it makes sense to +calculate how many particles + +you have given that you have +fixed the chemical potential. + +So for that we +note the following. + +That essentially, we were able +to do this calculation for Q + +because it was a +product of contributions + +that we had for the individual +one-particle states. + +So clearly, as far as this +normalization is concerned, + +the individual one-particle +states are independent. + +And indeed, what we can say +is that in this ensemble, + +there is a classical probability +for a set of occupation numbers + +of one particle +states, which is simply + +a product over the different +one-particle states of e + +to the beta mu minus epsilon +k nk appropriately normalized. + +And again, the +restriction on n's + +being 0 or 1 for +fermions or anything + +for bosons would be +implicit in either case. + +But in either case, essentially +the occupation numbers + +are independently taken +from distributions + +that I've discussed [INAUDIBLE]. + +So you can, in +fact, independently + +calculate the average +occupation number + +that you have for each one of +these single-particle states. + +And it's clear that you could +get that by, for example, + +bringing down a +factor of nk here. + +And you can bring +down a factor of nk + +by taking a derivative of Q +with respect to beta epsilon k + +with a minus sign +and normalizing it, + +so you would have log. + +So you would have an +expression such as this. + +So you basically would +need to calculate, + +since you are taking +derivative with respect + +to epsilon k the corresponding +log for which epsilon + +k appears. + +Actually, for the +case of fermions, + +really there are +two possibilities. + +n is either 0 or 1. + +So you would say that the +expectation value would + +be when it is 1, you have e to +the beta epsilon of k minus mu. + +Oops. + +e to the beta mu +minus epsilon of k. + +The two possibilities +are 1 plus e + +to the beta mu +minus epsilon of k. + +So when I look at +some particular state, + +it is either empty. + +In which case, contributes 0. + +Or, it is occupied. + +In which case, it +contributes this weight, + +which has to be +appropriately normalized. + +If I do the same thing +for the case of bosons, + +it is a bit more +complicated because I + +have to look at this series +rather than geometric 1 + +plus x plus x squared +plus x cubed is + +1 plus x plus 2x squared plus +3x cubed, which can be obtained + +by taking the derivative +of the appropriate log. + +Or you can fall back +on your calculations + +of geometric series +and convince yourself + +that it is essentially the same +thing with a factor of minus + +here. + +So this is fermions +and this is bosons. + +And indeed, I can put the +two expressions together + +by dividing through this +factor in both of them + +and write it as 1 +over Z inverse e + +to the beta epsilon +of k minus eta, + +where for convenience +I have introduced + +Z to be the contribution +e to the beta. + +So for this system of +non-interacting particles + +that are identical, +we have expressions + +for log of the grand partition +function, the grand potential. + +And for the average +number of particles, + +which is an appropriate +derivative of this, + +expressed in terms of the +single-particle energy + +levels and the +chemical potential. + +So next time, what +we will do is we + +will start this +with this expression + +for the case of the +particles in a box + +to get the pressure of +the ideal quantum gas + +as a function of mu. + +But we want to +write the pressure + +as a function of density, so +we will invert this expression + +to get density as a +function of-- chemical + +potential as a function of +density [INAUDIBLE] here. + +And therefore, get the +expression for pressure + +as a function of density. \ No newline at end of file diff --git a/iJvEgQkLjow.txt b/iJvEgQkLjow.txt new file mode 100644 index 0000000000000000000000000000000000000000..125bb5994519f64ece15aec7c2d0d6614db5bfb4 --- /dev/null +++ b/iJvEgQkLjow.txt @@ -0,0 +1,1243 @@ +align:start position:0% + +in this video we'll build a cart model + + align:start position:0% +in this video we'll build a cart model + + + align:start position:0% +in this video we'll build a cart model +to predict healthcare cost + + align:start position:0% +to predict healthcare cost + + + align:start position:0% +to predict healthcare cost +first let's make sure the packages are + + align:start position:0% +first let's make sure the packages are + + + align:start position:0% +first let's make sure the packages are +part and are part plot are loaded with + + align:start position:0% +part and are part plot are loaded with + + + align:start position:0% +part and are part plot are loaded with +the library function you should have + + align:start position:0% +the library function you should have + + + align:start position:0% +the library function you should have +already installed them in the previous + + align:start position:0% +already installed them in the previous + + + align:start position:0% +already installed them in the previous +lecture on predicting Supreme Court + + align:start position:0% +lecture on predicting Supreme Court + + + align:start position:0% +lecture on predicting Supreme Court +decisions now let's build our cart model + + align:start position:0% +decisions now let's build our cart model + + + align:start position:0% +decisions now let's build our cart model +will call it claims tree and we'll use + + align:start position:0% +will call it claims tree and we'll use + + + align:start position:0% +will call it claims tree and we'll use +the our part function to predict bucket + + align:start position:0% +the our part function to predict bucket + + + align:start position:0% +the our part function to predict bucket +2009 using as independent variables age + + align:start position:0% + + + + align:start position:0% + +arthritis Alzheimer's cancer COPD + + align:start position:0% + + + + align:start position:0% + +depression diabetes heart failure ihd + + align:start position:0% + + + + align:start position:0% + +kidney osteoporosis and stroke we'll + + align:start position:0% +kidney osteoporosis and stroke we'll + + + align:start position:0% +kidney osteoporosis and stroke we'll +also use bucket 2008 and reimbursement + + align:start position:0% +also use bucket 2008 and reimbursement + + + align:start position:0% +also use bucket 2008 and reimbursement +2008 the dataset will use to build our + + align:start position:0% +2008 the dataset will use to build our + + + align:start position:0% +2008 the dataset will use to build our +model is claims trained + + align:start position:0% +model is claims trained + + + align:start position:0% +model is claims trained +and then we'll add the arguments method + + align:start position:0% +and then we'll add the arguments method + + + align:start position:0% +and then we'll add the arguments method +equals class since we have a + + align:start position:0% +equals class since we have a + + + align:start position:0% +equals class since we have a +classification problem here and CP + + align:start position:0% +classification problem here and CP + + + align:start position:0% +classification problem here and CP +equals zero point zero zero zero zero + + align:start position:0% +equals zero point zero zero zero zero + + + align:start position:0% +equals zero point zero zero zero zero +five note that even though we have a + + align:start position:0% +five note that even though we have a + + + align:start position:0% +five note that even though we have a +multi-class classification problem here + + align:start position:0% +multi-class classification problem here + + + align:start position:0% +multi-class classification problem here +we built our tree in the same way as a + + align:start position:0% +we built our tree in the same way as a + + + align:start position:0% +we built our tree in the same way as a +binary classification problem so go + + align:start position:0% +binary classification problem so go + + + align:start position:0% +binary classification problem so go +ahead and hit enter the CP value we're + + align:start position:0% +ahead and hit enter the CP value we're + + + align:start position:0% +ahead and hit enter the CP value we're +using here was selected through + + align:start position:0% +using here was selected through + + + align:start position:0% +using here was selected through +cross-validation on the training set we + + align:start position:0% +cross-validation on the training set we + + + align:start position:0% +cross-validation on the training set we +won't perform the cross-validation here + + align:start position:0% +won't perform the cross-validation here + + + align:start position:0% +won't perform the cross-validation here +because it takes a significant amount of + + align:start position:0% +because it takes a significant amount of + + + align:start position:0% +because it takes a significant amount of +time on a data set of this size remember + + align:start position:0% +time on a data set of this size remember + + + align:start position:0% +time on a data set of this size remember +that we have almost two hundred and + + align:start position:0% +that we have almost two hundred and + + + align:start position:0% +that we have almost two hundred and +seventy-five thousand observations in + + align:start position:0% +seventy-five thousand observations in + + + align:start position:0% +seventy-five thousand observations in +our training set but keep in mind that + + align:start position:0% +our training set but keep in mind that + + + align:start position:0% +our training set but keep in mind that +the R commands needed for + + align:start position:0% +the R commands needed for + + + align:start position:0% +the R commands needed for +cross-validation here are the same as + + align:start position:0% +cross-validation here are the same as + + + align:start position:0% +cross-validation here are the same as +those used in the previous lecture on + + align:start position:0% +those used in the previous lecture on + + + align:start position:0% +those used in the previous lecture on +predicting Supreme Court decisions so + + align:start position:0% +predicting Supreme Court decisions so + + + align:start position:0% +predicting Supreme Court decisions so +now that our models done let's take a + + align:start position:0% +now that our models done let's take a + + + align:start position:0% +now that our models done let's take a +look at our tree with the PRP function + + align:start position:0% + + + + align:start position:0% + +it might take a while to load because we + + align:start position:0% +it might take a while to load because we + + + align:start position:0% +it might take a while to load because we +have a huge tree here this makes sense + + align:start position:0% +have a huge tree here this makes sense + + + align:start position:0% +have a huge tree here this makes sense +for a few reasons + + align:start position:0% +for a few reasons + + + align:start position:0% +for a few reasons +one is the large number of observations + + align:start position:0% +one is the large number of observations + + + align:start position:0% +one is the large number of observations +in our training set another is that we + + align:start position:0% +in our training set another is that we + + + align:start position:0% +in our training set another is that we +have a 5 class classification problem so + + align:start position:0% +have a 5 class classification problem so + + + align:start position:0% +have a 5 class classification problem so +that classification is more complex than + + align:start position:0% +that classification is more complex than + + + align:start position:0% +that classification is more complex than +a binary classification case like the + + align:start position:0% +a binary classification case like the + + + align:start position:0% +a binary classification case like the +one we saw in the previous lecture the + + align:start position:0% +one we saw in the previous lecture the + + + align:start position:0% +one we saw in the previous lecture the +trees used by D to Hawkeye were also + + align:start position:0% +trees used by D to Hawkeye were also + + + align:start position:0% +trees used by D to Hawkeye were also +very large car trees while this hurts + + align:start position:0% +very large car trees while this hurts + + + align:start position:0% +very large car trees while this hurts +the interpret ability of the model it's + + align:start position:0% +the interpret ability of the model it's + + + align:start position:0% +the interpret ability of the model it's +still possible to describe each of the + + align:start position:0% +still possible to describe each of the + + + align:start position:0% +still possible to describe each of the +buckets of the tree according to the + + align:start position:0% +buckets of the tree according to the + + + align:start position:0% +buckets of the tree according to the +splits so now let's make predictions on + + align:start position:0% +splits so now let's make predictions on + + + align:start position:0% +splits so now let's make predictions on +the test set so go back to your R + + align:start position:0% +the test set so go back to your R + + + align:start position:0% +the test set so go back to your R +console and we'll call our predictions + + align:start position:0% +console and we'll call our predictions + + + align:start position:0% +console and we'll call our predictions +predict test + + align:start position:0% +predict test + + + align:start position:0% +predict test +where we'll use the predict function for + + align:start position:0% +where we'll use the predict function for + + + align:start position:0% +where we'll use the predict function for +our model claims tree and our new data + + align:start position:0% +our model claims tree and our new data + + + align:start position:0% +our model claims tree and our new data +is claims test and we want to add type + + align:start position:0% +is claims test and we want to add type + + + align:start position:0% +is claims test and we want to add type +equals class to get class predictions + + align:start position:0% +equals class to get class predictions + + + align:start position:0% +equals class to get class predictions +and we can make our classification + + align:start position:0% +and we can make our classification + + + align:start position:0% +and we can make our classification +matrix on the test set to compute the + + align:start position:0% +matrix on the test set to compute the + + + align:start position:0% +matrix on the test set to compute the +accuracy so we'll use the table function + + align:start position:0% +accuracy so we'll use the table function + + + align:start position:0% +accuracy so we'll use the table function +where the actual outcomes are claims + + align:start position:0% +where the actual outcomes are claims + + + align:start position:0% +where the actual outcomes are claims +test bucket 2009 and our predictions are + + align:start position:0% +test bucket 2009 and our predictions are + + + align:start position:0% +test bucket 2009 and our predictions are +predict tests so to compute the accuracy + + align:start position:0% +predict tests so to compute the accuracy + + + align:start position:0% +predict tests so to compute the accuracy +we need to add up the numbers on the + + align:start position:0% +we need to add up the numbers on the + + + align:start position:0% +we need to add up the numbers on the +diagonal and divide by the total number + + align:start position:0% +diagonal and divide by the total number + + + align:start position:0% +diagonal and divide by the total number +of observations in our test set so we + + align:start position:0% +of observations in our test set so we + + + align:start position:0% +of observations in our test set so we +have one hundred and fourteen thousand + + align:start position:0% +have one hundred and fourteen thousand + + + align:start position:0% +have one hundred and fourteen thousand +one hundred and forty-one plus sixteen + + align:start position:0% +one hundred and forty-one plus sixteen + + + align:start position:0% +one hundred and forty-one plus sixteen +thousand one hundred and two plus one + + align:start position:0% +thousand one hundred and two plus one + + + align:start position:0% +thousand one hundred and two plus one +hundred and eighteen plus two hundred + + align:start position:0% +hundred and eighteen plus two hundred + + + align:start position:0% +hundred and eighteen plus two hundred +and one plus zero and we'll divide by + + align:start position:0% +and one plus zero and we'll divide by + + + align:start position:0% +and one plus zero and we'll divide by +the number of rows in claims test so the + + align:start position:0% +the number of rows in claims test so the + + + align:start position:0% +the number of rows in claims test so the +accuracy of our model is point seven one + + align:start position:0% +accuracy of our model is point seven one + + + align:start position:0% +accuracy of our model is point seven one +three for the penalty error we can use + + align:start position:0% +three for the penalty error we can use + + + align:start position:0% +three for the penalty error we can use +our penalty matrix like we did in the + + align:start position:0% +our penalty matrix like we did in the + + + align:start position:0% +our penalty matrix like we did in the +previous video so scroll up to the + + align:start position:0% +previous video so scroll up to the + + + align:start position:0% +previous video so scroll up to the +classification matrix command and + + align:start position:0% +classification matrix command and + + + align:start position:0% +classification matrix command and +surround the table function by the as + + align:start position:0% +surround the table function by the as + + + align:start position:0% +surround the table function by the as +dot matrix function and then we'll + + align:start position:0% +dot matrix function and then we'll + + + align:start position:0% +dot matrix function and then we'll +multiply by penalty matrix so remember + + align:start position:0% +multiply by penalty matrix so remember + + + align:start position:0% +multiply by penalty matrix so remember +that this takes each entry in our + + align:start position:0% +that this takes each entry in our + + + align:start position:0% +that this takes each entry in our +classification matrix and multiplies it + + align:start position:0% +classification matrix and multiplies it + + + align:start position:0% +classification matrix and multiplies it +by the corresponding number in the + + align:start position:0% +by the corresponding number in the + + + align:start position:0% +by the corresponding number in the +penalty matrix so now we just need to + + align:start position:0% +penalty matrix so now we just need to + + + align:start position:0% +penalty matrix so now we just need to +add up all of the numbers in this matrix + + align:start position:0% +add up all of the numbers in this matrix + + + align:start position:0% +add up all of the numbers in this matrix +by surrounding it by the sum function + + align:start position:0% +by surrounding it by the sum function + + + align:start position:0% +by surrounding it by the sum function +and then dividing by the total number of + + align:start position:0% +and then dividing by the total number of + + + align:start position:0% +and then dividing by the total number of +observations in our test set or n row + + align:start position:0% +observations in our test set or n row + + + align:start position:0% +observations in our test set or n row +claims test so our penalty err is 0.75 + + align:start position:0% +claims test so our penalty err is 0.75 + + + align:start position:0% +claims test so our penalty err is 0.75 +in the previous video we saw that our + + align:start position:0% +in the previous video we saw that our + + + align:start position:0% +in the previous video we saw that our +baseline method had an accuracy of 68% + + align:start position:0% +baseline method had an accuracy of 68% + + + align:start position:0% +baseline method had an accuracy of 68% +and a penalty err of 0.7 for so while we + + align:start position:0% +and a penalty err of 0.7 for so while we + + + align:start position:0% +and a penalty err of 0.7 for so while we +increase the accuracy the penalty air + + align:start position:0% +increase the accuracy the penalty air + + + align:start position:0% +increase the accuracy the penalty air +also went up why by default our part + + align:start position:0% +also went up why by default our part + + + align:start position:0% +also went up why by default our part +will try to maximize the overall + + align:start position:0% +will try to maximize the overall + + + align:start position:0% +will try to maximize the overall +accuracy and every type of error is seen + + align:start position:0% +accuracy and every type of error is seen + + + align:start position:0% +accuracy and every type of error is seen +as having a penalty of 1 our current + + align:start position:0% +as having a penalty of 1 our current + + + align:start position:0% +as having a penalty of 1 our current +model predicts 3 4 and 5 so rarely + + align:start position:0% +model predicts 3 4 and 5 so rarely + + + align:start position:0% +model predicts 3 4 and 5 so rarely +because there are very few observations + + align:start position:0% +because there are very few observations + + + align:start position:0% +because there are very few observations +in these classes so we don't really + + align:start position:0% +in these classes so we don't really + + + align:start position:0% +in these classes so we don't really +expect this model to do better on the + + align:start position:0% +expect this model to do better on the + + + align:start position:0% +expect this model to do better on the +penalty air than the baseline method so + + align:start position:0% +penalty air than the baseline method so + + + align:start position:0% +penalty air than the baseline method so +how can we fix this the armed part + + align:start position:0% +how can we fix this the armed part + + + align:start position:0% +how can we fix this the armed part +function allows us to specify a + + align:start position:0% +function allows us to specify a + + + align:start position:0% +function allows us to specify a +parameter called loss this is the + + align:start position:0% +parameter called loss this is the + + + align:start position:0% +parameter called loss this is the +penalty matrix we want to use when + + align:start position:0% +penalty matrix we want to use when + + + align:start position:0% +penalty matrix we want to use when +building our model so let's scroll back + + align:start position:0% +building our model so let's scroll back + + + align:start position:0% +building our model so let's scroll back +up to where we built our carp model at + + align:start position:0% +up to where we built our carp model at + + + align:start position:0% +up to where we built our carp model at +the end of the our part function will + + align:start position:0% +the end of the our part function will + + + align:start position:0% +the end of the our part function will +add the argument params equals list and + + align:start position:0% +add the argument params equals list and + + + align:start position:0% +add the argument params equals list and +then in parentheses loss equals penalty + + align:start position:0% +then in parentheses loss equals penalty + + + align:start position:0% +then in parentheses loss equals penalty +matrix this is the name of the penalty + + align:start position:0% +matrix this is the name of the penalty + + + align:start position:0% +matrix this is the name of the penalty +matrix we created close the parentheses + + align:start position:0% +matrix we created close the parentheses + + + align:start position:0% +matrix we created close the parentheses +and hit enter so why our while our model + + align:start position:0% +and hit enter so why our while our model + + + align:start position:0% +and hit enter so why our while our model +is being built let's think about what we + + align:start position:0% +is being built let's think about what we + + + align:start position:0% +is being built let's think about what we +expect to happen if the armed part + + align:start position:0% +expect to happen if the armed part + + + align:start position:0% +expect to happen if the armed part +function knows that will be giving a + + align:start position:0% +function knows that will be giving a + + + align:start position:0% +function knows that will be giving a +higher penalty to some types of errors + + align:start position:0% +higher penalty to some types of errors + + + align:start position:0% +higher penalty to some types of errors +over others it might choose different + + align:start position:0% +over others it might choose different + + + align:start position:0% +over others it might choose different +splits when building the model to + + align:start position:0% +splits when building the model to + + + align:start position:0% +splits when building the model to +minimize the worst types of errors we'll + + align:start position:0% +minimize the worst types of errors we'll + + + align:start position:0% +minimize the worst types of errors we'll +probably get a lower overall accuracy + + align:start position:0% +probably get a lower overall accuracy + + + align:start position:0% +probably get a lower overall accuracy +with this new model but hopefully the + + align:start position:0% +with this new model but hopefully the + + + align:start position:0% +with this new model but hopefully the +penalty error will be much lower too so + + align:start position:0% +penalty error will be much lower too so + + + align:start position:0% +penalty error will be much lower too so +now that our model is done let's + + align:start position:0% +now that our model is done let's + + + align:start position:0% +now that our model is done let's +regenerate our test set predictions by + + align:start position:0% +regenerate our test set predictions by + + + align:start position:0% +regenerate our test set predictions by +scrolling up to where we created predict + + align:start position:0% +scrolling up to where we created predict + + + align:start position:0% +scrolling up to where we created predict +test and hitting Enter and then + + align:start position:0% +test and hitting Enter and then + + + align:start position:0% +test and hitting Enter and then +recreating our classification matrix by + + align:start position:0% +recreating our classification matrix by + + + align:start position:0% +recreating our classification matrix by +scrolling up to the table function and + + align:start position:0% +scrolling up to the table function and + + + align:start position:0% +scrolling up to the table function and +hitting Enter again + + align:start position:0% +hitting Enter again + + + align:start position:0% +hitting Enter again +now let's add up the numbers on the + + align:start position:0% +now let's add up the numbers on the + + + align:start position:0% +now let's add up the numbers on the +diagonal 94 3 10 + 18 9 42 + 4690 2 + 6 + + align:start position:0% +diagonal 94 3 10 + 18 9 42 + 4690 2 + 6 + + + align:start position:0% +diagonal 94 3 10 + 18 9 42 + 4690 2 + 6 +36 + 2 and divide by the number of rows + + align:start position:0% +36 + 2 and divide by the number of rows + + + align:start position:0% +36 + 2 and divide by the number of rows +in claims test and hit enter so the + + align:start position:0% +in claims test and hit enter so the + + + align:start position:0% +in claims test and hit enter so the +accuracy of this model is 0.6 4 7 and we + + align:start position:0% +accuracy of this model is 0.6 4 7 and we + + + align:start position:0% +accuracy of this model is 0.6 4 7 and we +can scroll up and can you compute the + + align:start position:0% +can scroll up and can you compute the + + + align:start position:0% +can scroll up and can you compute the +penalty air here by going back to the + + align:start position:0% +penalty air here by going back to the + + + align:start position:0% +penalty air here by going back to the +sum command and hitting Enter + + align:start position:0% +sum command and hitting Enter + + + align:start position:0% +sum command and hitting Enter +so the penalty of our new model is 0.64 + + align:start position:0% +so the penalty of our new model is 0.64 + + + align:start position:0% +so the penalty of our new model is 0.64 +to our accuracy is now lower than the + + align:start position:0% +to our accuracy is now lower than the + + + align:start position:0% +to our accuracy is now lower than the +baseline method but our penalty air is + + align:start position:0% +baseline method but our penalty air is + + + align:start position:0% +baseline method but our penalty air is +also much lower note that we have + + align:start position:0% +also much lower note that we have + + + align:start position:0% +also much lower note that we have +significantly fewer independent + + align:start position:0% +significantly fewer independent + + + align:start position:0% +significantly fewer independent +variables than d2 hawk I had if we had + + align:start position:0% +variables than d2 hawk I had if we had + + + align:start position:0% +variables than d2 hawk I had if we had +the hundreds of codes and risk factors + + align:start position:0% +the hundreds of codes and risk factors + + + align:start position:0% +the hundreds of codes and risk factors +available to d2 Hawkeye we would + + align:start position:0% +available to d2 Hawkeye we would + + + align:start position:0% +available to d2 Hawkeye we would +hopefully do even better in the next + + align:start position:0% +hopefully do even better in the next + + + align:start position:0% +hopefully do even better in the next +video we'll discuss the accuracy of the + + align:start position:0% +video we'll discuss the accuracy of the + + + align:start position:0% +video we'll discuss the accuracy of the +models used by d2 Hawkeye and how + + align:start position:0% +models used by d2 Hawkeye and how + + + align:start position:0% +models used by d2 Hawkeye and how +analytics can provide an edge \ No newline at end of file diff --git a/ipSdsosGJBs.txt b/ipSdsosGJBs.txt new file mode 100644 index 0000000000000000000000000000000000000000..07180d68cd274a2ea6544d2f7c09c5902fbfac1d --- /dev/null +++ b/ipSdsosGJBs.txt @@ -0,0 +1,1131 @@ +align:start position:0% + +we have presented the complete solution + + align:start position:0% +we have presented the complete solution + + + align:start position:0% +we have presented the complete solution +to the linear list mean squares + + align:start position:0% +to the linear list mean squares + + + align:start position:0% +to the linear list mean squares +estimation problem when we want to + + align:start position:0% +estimation problem when we want to + + + align:start position:0% +estimation problem when we want to +estimate a certain unknown random + + align:start position:0% +estimate a certain unknown random + + + align:start position:0% +estimate a certain unknown random +variable on the basis of a different + + align:start position:0% +variable on the basis of a different + + + align:start position:0% +variable on the basis of a different +random variable X that we get to observe + + align:start position:0% +random variable X that we get to observe + + + align:start position:0% +random variable X that we get to observe +but what if we have multiple + + align:start position:0% +but what if we have multiple + + + align:start position:0% +but what if we have multiple +observations what would be the analogous + + align:start position:0% +observations what would be the analogous + + + align:start position:0% +observations what would be the analogous +formulation of the problem here is the + + align:start position:0% +formulation of the problem here is the + + + align:start position:0% +formulation of the problem here is the +idea once more we restrict ourselves to + + align:start position:0% +idea once more we restrict ourselves to + + + align:start position:0% +idea once more we restrict ourselves to +estimators that are linear functions of + + align:start position:0% +estimators that are linear functions of + + + align:start position:0% +estimators that are linear functions of +the data linear functions of the + + align:start position:0% +the data linear functions of the + + + align:start position:0% +the data linear functions of the +observations that we have and then we + + align:start position:0% +observations that we have and then we + + + align:start position:0% +observations that we have and then we +pose the problem on finding the best + + align:start position:0% +pose the problem on finding the best + + + align:start position:0% +pose the problem on finding the best +choices of these coefficients a 1 up to + + align:start position:0% +choices of these coefficients a 1 up to + + + align:start position:0% +choices of these coefficients a 1 up to +a n and B what does it mean to find the + + align:start position:0% +a n and B what does it mean to find the + + + align:start position:0% +a n and B what does it mean to find the +best choices it means that if we fix + + align:start position:0% +best choices it means that if we fix + + + align:start position:0% +best choices it means that if we fix +certain choices we obtain an estimator + + align:start position:0% +certain choices we obtain an estimator + + + align:start position:0% +certain choices we obtain an estimator +we look at the difference between the + + align:start position:0% +we look at the difference between the + + + align:start position:0% +we look at the difference between the +estimator and that quantity were trying + + align:start position:0% +estimator and that quantity were trying + + + align:start position:0% +estimator and that quantity were trying +to estimate take the square and then + + align:start position:0% +to estimate take the square and then + + + align:start position:0% +to estimate take the square and then +take the expectation so once more we're + + align:start position:0% +take the expectation so once more we're + + + align:start position:0% +take the expectation so once more we're +looking at the mean squared error of our + + align:start position:0% +looking at the mean squared error of our + + + align:start position:0% +looking at the mean squared error of our +estimator and we try to make it as small + + align:start position:0% +estimator and we try to make it as small + + + align:start position:0% +estimator and we try to make it as small +as possible so this is a well-defined + + align:start position:0% +as possible so this is a well-defined + + + align:start position:0% +as possible so this is a well-defined +optimization problem we have a quantity + + align:start position:0% +optimization problem we have a quantity + + + align:start position:0% +optimization problem we have a quantity +which is a function of certain + + align:start position:0% +which is a function of certain + + + align:start position:0% +which is a function of certain +parameters and we wish to find the + + align:start position:0% +parameters and we wish to find the + + + align:start position:0% +parameters and we wish to find the +choices for those parameters or those + + align:start position:0% +choices for those parameters or those + + + align:start position:0% +choices for those parameters or those +coefficients that will make this + + align:start position:0% +coefficients that will make this + + + align:start position:0% +coefficients that will make this +quantity as small as possible one first + + align:start position:0% +quantity as small as possible one first + + + align:start position:0% +quantity as small as possible one first +comment is similar to the case where we + + align:start position:0% +comment is similar to the case where we + + + align:start position:0% +comment is similar to the case where we +had a single measurement is the + + align:start position:0% +had a single measurement is the + + + align:start position:0% +had a single measurement is the +following + + align:start position:0% +following + + + align:start position:0% +following +if it turns out the conditional + + align:start position:0% +if it turns out the conditional + + + align:start position:0% +if it turns out the conditional +expectation of theta given all the data + + align:start position:0% +expectation of theta given all the data + + + align:start position:0% +expectation of theta given all the data +that we have is linear in X if it is of + + align:start position:0% +that we have is linear in X if it is of + + + align:start position:0% +that we have is linear in X if it is of +this form then what happens we know that + + align:start position:0% +this form then what happens we know that + + + align:start position:0% +this form then what happens we know that +this is the best possible estimator if + + align:start position:0% +this is the best possible estimator if + + + align:start position:0% +this is the best possible estimator if +it is also linear then it is the best + + align:start position:0% +it is also linear then it is the best + + + align:start position:0% +it is also linear then it is the best +estimator within the class of linear + + align:start position:0% +estimator within the class of linear + + + align:start position:0% +estimator within the class of linear +estimators as well and therefore the + + align:start position:0% +estimators as well and therefore the + + + align:start position:0% +estimators as well and therefore the +linear least mean squares estimator is + + align:start position:0% +linear least mean squares estimator is + + + align:start position:0% +linear least mean squares estimator is +the same as the general least mean + + align:start position:0% +the same as the general least mean + + + align:start position:0% +the same as the general least mean +squares estimator so if for some + + align:start position:0% +squares estimator so if for some + + + align:start position:0% +squares estimator so if for some +problems it turns out that this is + + align:start position:0% +problems it turns out that this is + + + align:start position:0% +problems it turns out that this is +linear then we automatically also have + + align:start position:0% +linear then we automatically also have + + + align:start position:0% +linear then we automatically also have +the optimal linear + + align:start position:0% +the optimal linear + + + align:start position:0% +the optimal linear +estimator and this is going to be the + + align:start position:0% +estimator and this is going to be the + + + align:start position:0% +estimator and this is going to be the +case once more for certain normal + + align:start position:0% +case once more for certain normal + + + align:start position:0% +case once more for certain normal +problems with a linear structure of the + + align:start position:0% +problems with a linear structure of the + + + align:start position:0% +problems with a linear structure of the +type that we have studied earlier now + + align:start position:0% +type that we have studied earlier now + + + align:start position:0% +type that we have studied earlier now +let us look into what it takes to carry + + align:start position:0% +let us look into what it takes to carry + + + align:start position:0% +let us look into what it takes to carry +out this optimization if we had a single + + align:start position:0% +out this optimization if we had a single + + + align:start position:0% +out this optimization if we had a single +observation then we have seen a closed + + align:start position:0% +observation then we have seen a closed + + + align:start position:0% +observation then we have seen a closed +form formula a fairly simple formula + + align:start position:0% +form formula a fairly simple formula + + + align:start position:0% +form formula a fairly simple formula +that tells us what the coefficients + + align:start position:0% +that tells us what the coefficients + + + align:start position:0% +that tells us what the coefficients +should be for the more general case + + align:start position:0% +should be for the more general case + + + align:start position:0% +should be for the more general case +formulas would not be as simple but we + + align:start position:0% +formulas would not be as simple but we + + + align:start position:0% +formulas would not be as simple but we +can make the following observations if + + align:start position:0% +can make the following observations if + + + align:start position:0% +can make the following observations if +you take this expression and expand it + + align:start position:0% +you take this expression and expand it + + + align:start position:0% +you take this expression and expand it +it's going to have a bunch of terms for + + align:start position:0% +it's going to have a bunch of terms for + + + align:start position:0% +it's going to have a bunch of terms for +example it's going to have a term of the + + align:start position:0% +example it's going to have a term of the + + + align:start position:0% +example it's going to have a term of the +form a1 squared times the expected value + + align:start position:0% +form a1 squared times the expected value + + + align:start position:0% +form a1 squared times the expected value +of x1 squared it's going to have a term + + align:start position:0% +of x1 squared it's going to have a term + + + align:start position:0% +of x1 squared it's going to have a term +such as twice a1 a2 times the expected + + align:start position:0% +such as twice a1 a2 times the expected + + + align:start position:0% +such as twice a1 a2 times the expected +value of x1 x2 and then there's going to + + align:start position:0% +value of x1 x2 and then there's going to + + + align:start position:0% +value of x1 x2 and then there's going to +be many more terms + + align:start position:0% +be many more terms + + + align:start position:0% +be many more terms +some of them will also involve products + + align:start position:0% +some of them will also involve products + + + align:start position:0% +some of them will also involve products +of theta with this so we might see that + + align:start position:0% +of theta with this so we might see that + + + align:start position:0% +of theta with this so we might see that +we have a term of the form a1 expected + + align:start position:0% +we have a term of the form a1 expected + + + align:start position:0% +we have a term of the form a1 expected +value of x1 theta and then there's going + + align:start position:0% +value of x1 theta and then there's going + + + align:start position:0% +value of x1 theta and then there's going +to be many many more terms what's the + + align:start position:0% +to be many many more terms what's the + + + align:start position:0% +to be many many more terms what's the +important thing to notice that this + + align:start position:0% +important thing to notice that this + + + align:start position:0% +important thing to notice that this +expression as a function of the + + align:start position:0% +expression as a function of the + + + align:start position:0% +expression as a function of the +coefficient involves terms either of + + align:start position:0% +coefficient involves terms either of + + + align:start position:0% +coefficient involves terms either of +this kind or of this kind or of that + + align:start position:0% +this kind or of this kind or of that + + + align:start position:0% +this kind or of this kind or of that +kind first-order or second-order terms + + align:start position:0% +kind first-order or second-order terms + + + align:start position:0% +kind first-order or second-order terms +to minimize this expression we're going + + align:start position:0% +to minimize this expression we're going + + + align:start position:0% +to minimize this expression we're going +to take the derivative of this and set + + align:start position:0% +to take the derivative of this and set + + + align:start position:0% +to take the derivative of this and set +it equal to 0 + + align:start position:0% +it equal to 0 + + + align:start position:0% +it equal to 0 +when you take the derivative of a + + align:start position:0% +when you take the derivative of a + + + align:start position:0% +when you take the derivative of a +function that involves only quadratic + + align:start position:0% +function that involves only quadratic + + + align:start position:0% +function that involves only quadratic +and linear terms you get something + + align:start position:0% +and linear terms you get something + + + align:start position:0% +and linear terms you get something +that's linear in the coefficients the + + align:start position:0% +that's linear in the coefficients the + + + align:start position:0% +that's linear in the coefficients the +conclusion out of all this discussion is + + align:start position:0% +conclusion out of all this discussion is + + + align:start position:0% +conclusion out of all this discussion is +that when you actually go and carry out + + align:start position:0% +that when you actually go and carry out + + + align:start position:0% +that when you actually go and carry out +this minimization by setting the + + align:start position:0% +this minimization by setting the + + + align:start position:0% +this minimization by setting the +riveters to zero what you will end up + + align:start position:0% +riveters to zero what you will end up + + + align:start position:0% +riveters to zero what you will end up +doing is + + align:start position:0% +doing is + + + align:start position:0% +doing is +solving a system of linear equations in + + align:start position:0% +solving a system of linear equations in + + + align:start position:0% +solving a system of linear equations in +the coefficients that you are trying to + + align:start position:0% +the coefficients that you are trying to + + + align:start position:0% +the coefficients that you are trying to +determine and why is this interesting + + align:start position:0% +determine and why is this interesting + + + align:start position:0% +determine and why is this interesting +well it is because if you actually want + + align:start position:0% +well it is because if you actually want + + + align:start position:0% +well it is because if you actually want +to carry out this minimization all you + + align:start position:0% +to carry out this minimization all you + + + align:start position:0% +to carry out this minimization all you +need to do is to solve a linear system + + align:start position:0% +need to do is to solve a linear system + + + align:start position:0% +need to do is to solve a linear system +which is easily done on a computer the + + align:start position:0% +which is easily done on a computer the + + + align:start position:0% +which is easily done on a computer the +next observation is that this expression + + align:start position:0% +next observation is that this expression + + + align:start position:0% +next observation is that this expression +only involves expectations of various + + align:start position:0% +only involves expectations of various + + + align:start position:0% +only involves expectations of various +terms that are second-order in the + + align:start position:0% +terms that are second-order in the + + + align:start position:0% +terms that are second-order in the +random variables involved so it involves + + align:start position:0% +random variables involved so it involves + + + align:start position:0% +random variables involved so it involves +the expected value of x1 squared it + + align:start position:0% +the expected value of x1 squared it + + + align:start position:0% +the expected value of x1 squared it +involves this term which has something + + align:start position:0% +involves this term which has something + + + align:start position:0% +involves this term which has something +to do with the covariance of X 1 and X 2 + + align:start position:0% +to do with the covariance of X 1 and X 2 + + + align:start position:0% +to do with the covariance of X 1 and X 2 +this term that has something to do with + + align:start position:0% +this term that has something to do with + + + align:start position:0% +this term that has something to do with +the covariance of X 1 with theta but + + align:start position:0% +the covariance of X 1 with theta but + + + align:start position:0% +the covariance of X 1 with theta but +these are all the only terms out of the + + align:start position:0% +these are all the only terms out of the + + + align:start position:0% +these are all the only terms out of the +distribution of the XS and the Thetas + + align:start position:0% +distribution of the XS and the Thetas + + + align:start position:0% +distribution of the XS and the Thetas +that will matter so similar to the case + + align:start position:0% +that will matter so similar to the case + + + align:start position:0% +that will matter so similar to the case +where we had a single observation in + + align:start position:0% +where we had a single observation in + + + align:start position:0% +where we had a single observation in +order to solve this problem we do not + + align:start position:0% +order to solve this problem we do not + + + align:start position:0% +order to solve this problem we do not +need to know the complete distribution + + align:start position:0% +need to know the complete distribution + + + align:start position:0% +need to know the complete distribution +of the x's and of theta it is enough to + + align:start position:0% +of the x's and of theta it is enough to + + + align:start position:0% +of the x's and of theta it is enough to +know all the means variances and + + align:start position:0% +know all the means variances and + + + align:start position:0% +know all the means variances and +covariances of the random variables that + + align:start position:0% +covariances of the random variables that + + + align:start position:0% +covariances of the random variables that +are involved and once more this makes + + align:start position:0% +are involved and once more this makes + + + align:start position:0% +are involved and once more this makes +this approach to estimation a practical + + align:start position:0% +this approach to estimation a practical + + + align:start position:0% +this approach to estimation a practical +one because we do not need to model in + + align:start position:0% +one because we do not need to model in + + + align:start position:0% +one because we do not need to model in +complete detail the distribution of the + + align:start position:0% +complete detail the distribution of the + + + align:start position:0% +complete detail the distribution of the +different random variables finally if we + + align:start position:0% +different random variables finally if we + + + align:start position:0% +different random variables finally if we +do not have just one unknown random + + align:start position:0% +do not have just one unknown random + + + align:start position:0% +do not have just one unknown random +variable but we have multiple random + + align:start position:0% +variable but we have multiple random + + + align:start position:0% +variable but we have multiple random +variables that we want to estimate what + + align:start position:0% +variables that we want to estimate what + + + align:start position:0% +variables that we want to estimate what +should we do + + align:start position:0% +should we do + + + align:start position:0% +should we do +well this is pretty simple you just + + align:start position:0% +well this is pretty simple you just + + + align:start position:0% +well this is pretty simple you just +apply this estimation methodology to + + align:start position:0% +apply this estimation methodology to + + + align:start position:0% +apply this estimation methodology to +each one of the unknown random variables + + align:start position:0% +each one of the unknown random variables + + + align:start position:0% +each one of the unknown random variables +separately to conclude this linear + + align:start position:0% +separately to conclude this linear + + + align:start position:0% +separately to conclude this linear +estimation methodology applies also to + + align:start position:0% +estimation methodology applies also to + + + align:start position:0% +estimation methodology applies also to +the case where you have multiple + + align:start position:0% +the case where you have multiple + + + align:start position:0% +the case where you have multiple +observations you need to solve a certain + + align:start position:0% +observations you need to solve a certain + + + align:start position:0% +observations you need to solve a certain +computational problem in order to find + + align:start position:0% +computational problem in order to find + + + align:start position:0% +computational problem in order to find +the structure of the best linear + + align:start position:0% +the structure of the best linear + + + align:start position:0% +the structure of the best linear +estimator but it is not a very difficult + + align:start position:0% +estimator but it is not a very difficult + + + align:start position:0% +estimator but it is not a very difficult +computational problem because all that + + align:start position:0% +computational problem because all that + + + align:start position:0% +computational problem because all that +it involves is to minimize a quadratic + + align:start position:0% +it involves is to minimize a quadratic + + + align:start position:0% +it involves is to minimize a quadratic +function of the coefficients that you're + + align:start position:0% +function of the coefficients that you're + + + align:start position:0% +function of the coefficients that you're +trying to determine and this leads us to + + align:start position:0% +trying to determine and this leads us to + + + align:start position:0% +trying to determine and this leads us to +having to solve a system of linear + + align:start position:0% +having to solve a system of linear + + + align:start position:0% +having to solve a system of linear +equations for all these reasons linear + + align:start position:0% +equations for all these reasons linear + + + align:start position:0% +equations for all these reasons linear +estimation or estimation using linear + + align:start position:0% +estimation or estimation using linear + + + align:start position:0% +estimation or estimation using linear +estimators is quite practical \ No newline at end of file diff --git a/jd4es6Bo600.txt b/jd4es6Bo600.txt new file mode 100644 index 0000000000000000000000000000000000000000..c3f3486422fdb54ebb91fefd669acaf251439884 --- /dev/null +++ b/jd4es6Bo600.txt @@ -0,0 +1,1171 @@ +align:start position:0% + +to find our spinal solution we just have + + align:start position:0% +to find our spinal solution we just have + + + align:start position:0% +to find our spinal solution we just have +to match the equation so sorry + + align:start position:0% +to match the equation so sorry + + + align:start position:0% +to match the equation so sorry +continuous at x equals a and what do we + + align:start position:0% +continuous at x equals a and what do we + + + align:start position:0% +continuous at x equals a and what do we +have well from 2 you have cosine of K a + + align:start position:0% +have well from 2 you have cosine of K a + + + align:start position:0% +have well from 2 you have cosine of K a +and from 4 you would have a equal e to + + align:start position:0% +and from 4 you would have a equal e to + + + align:start position:0% +and from 4 you would have a equal e to +the minus K a this is the value of this + + align:start position:0% +the minus K a this is the value of this + + + align:start position:0% +the minus K a this is the value of this +so the interior solution at X equal a + + align:start position:0% +so the interior solution at X equal a + + + align:start position:0% +so the interior solution at X equal a +must match the value of the exterior + + align:start position:0% +must match the value of the exterior + + + align:start position:0% +must match the value of the exterior +solution category sorry Prime must be + + align:start position:0% +solution category sorry Prime must be + + + align:start position:0% +solution category sorry Prime must be +continuous at x equals a as well well + + align:start position:0% +continuous at x equals a as well well + + + align:start position:0% +continuous at x equals a as well well +what is the derivative of this function + + align:start position:0% +what is the derivative of this function + + + align:start position:0% +what is the derivative of this function +is minus the sine of this is minus K + + align:start position:0% +is minus the sine of this is minus K + + + align:start position:0% +is minus the sine of this is minus K +sine of KX that becomes K a is equal to + + align:start position:0% +sine of KX that becomes K a is equal to + + + align:start position:0% +sine of KX that becomes K a is equal to +the derivative of that one which is + + align:start position:0% +the derivative of that one which is + + + align:start position:0% +the derivative of that one which is +minus Kappa a e to the minus Kappa will + + align:start position:0% +minus Kappa a e to the minus Kappa will + + + align:start position:0% +minus Kappa a e to the minus Kappa will +a two equations and how many unknowns + + align:start position:0% +a two equations and how many unknowns + + + align:start position:0% +a two equations and how many unknowns +well of there's a and some information + + align:start position:0% +well of there's a and some information + + + align:start position:0% +well of there's a and some information +about Kappa K and the easiest way to + + align:start position:0% +about Kappa K and the easiest way to + + + align:start position:0% +about Kappa K and the easiest way to +eliminate that is to divide them so you + + align:start position:0% +eliminate that is to divide them so you + + + align:start position:0% +eliminate that is to divide them so you +divide the bottom equation by this + + align:start position:0% +divide the bottom equation by this + + + align:start position:0% +divide the bottom equation by this +equation so what do we get + + align:start position:0% +equation so what do we get + + + align:start position:0% +equation so what do we get +divide the bottom by the top minus K and + + align:start position:0% +divide the bottom by the top minus K and + + + align:start position:0% +divide the bottom by the top minus K and +the - the minuses cancel we can cancel + + align:start position:0% +the - the minuses cancel we can cancel + + + align:start position:0% +the - the minuses cancel we can cancel +those minus sign and get K 10 K a is + + align:start position:0% +those minus sign and get K 10 K a is + + + align:start position:0% +those minus sign and get K 10 K a is +equal to minus Kappa but + + align:start position:0% +equal to minus Kappa but + + + align:start position:0% +equal to minus Kappa but +you're ready are convinced I hope on the + + align:start position:0% +you're ready are convinced I hope on the + + + align:start position:0% +you're ready are convinced I hope on the +idea that we should not use equations + + align:start position:0% +idea that we should not use equations + + + align:start position:0% +idea that we should not use equations +that have units so I will multiply by + + align:start position:0% +that have units so I will multiply by + + + align:start position:0% +that have units so I will multiply by +little a and little a to get a decent + + align:start position:0% +little a and little a to get a decent + + + align:start position:0% +little a and little a to get a decent +size and therefore that right-hand side + + align:start position:0% +size and therefore that right-hand side + + + align:start position:0% +size and therefore that right-hand side +becomes sy equals and the left-hand side + + align:start position:0% +becomes sy equals and the left-hand side + + + align:start position:0% +becomes sy equals and the left-hand side +becomes a de tan ADA + + align:start position:0% + + + + align:start position:0% + +okay I want to make a little comment + + align:start position:0% +okay I want to make a little comment + + + align:start position:0% +okay I want to make a little comment +about this quantities already so all the + + align:start position:0% +about this quantities already so all the + + + align:start position:0% +about this quantities already so all the +problem has turned out into the + + align:start position:0% +problem has turned out into the + + + align:start position:0% +problem has turned out into the +following you were given a potential + + align:start position:0% +following you were given a potential + + + align:start position:0% +following you were given a potential +that determines a number Z naught if you + + align:start position:0% +that determines a number Z naught if you + + + align:start position:0% +that determines a number Z naught if you +know the width and everything you know Z + + align:start position:0% +know the width and everything you know Z + + + align:start position:0% +know the width and everything you know Z +naught now you have to calculate 8 and + + align:start position:0% +naught now you have to calculate 8 and + + + align:start position:0% +naught now you have to calculate 8 and +sy if you know either a top or side you + + align:start position:0% +sy if you know either a top or side you + + + align:start position:0% +sy if you know either a top or side you +know Kappa or K and if you know either K + + align:start position:0% +know Kappa or K and if you know either K + + + align:start position:0% +know Kappa or K and if you know either K +or Kappa since you know V naught you + + align:start position:0% +or Kappa since you know V naught you + + + align:start position:0% +or Kappa since you know V naught you +will know the energy so it it kind of + + align:start position:0% +will know the energy so it it kind of + + + align:start position:0% +will know the energy so it it kind of +neat to express this more clearly and I + + align:start position:0% +neat to express this more clearly and I + + + align:start position:0% +neat to express this more clearly and I +think it's maybe easier if one uses X I + + align:start position:0% +think it's maybe easier if one uses X I + + + align:start position:0% +think it's maybe easier if one uses X I +and look at size squared is Kappa + + align:start position:0% +and look at size squared is Kappa + + + align:start position:0% +and look at size squared is Kappa +squared times a squared and what is + + align:start position:0% +squared times a squared and what is + + + align:start position:0% +squared times a squared and what is +Kappa squared is over there to M + + align:start position:0% +Kappa squared is over there to M + + + align:start position:0% +Kappa squared is over there to M +absolute value of a squared over H bar + + align:start position:0% +absolute value of a squared over H bar + + + align:start position:0% +absolute value of a squared over H bar +squared now you want to find e you're + + align:start position:0% +squared now you want to find e you're + + + align:start position:0% +squared now you want to find e you're +gonna get it in some units even is nice + + align:start position:0% +gonna get it in some units even is nice + + + align:start position:0% +gonna get it in some units even is nice +to have it without units so I will + + align:start position:0% +to have it without units so I will + + + align:start position:0% +to have it without units so I will +multiply and divide by V naught 2 m + + align:start position:0% +multiply and divide by V naught 2 m + + + align:start position:0% +multiply and divide by V naught 2 m +v-not a squared over H squared absolute + + align:start position:0% +v-not a squared over H squared absolute + + + align:start position:0% +v-not a squared over H squared absolute +value of e over V not after all you + + align:start position:0% +value of e over V not after all you + + + align:start position:0% +value of e over V not after all you +probably prefer to know I over V naught + + align:start position:0% +probably prefer to know I over V naught + + + align:start position:0% +probably prefer to know I over V naught +which tells you how proportional the + + align:start position:0% +which tells you how proportional the + + + align:start position:0% +which tells you how proportional the +energy is to the depth of the potential + + align:start position:0% +energy is to the depth of the potential + + + align:start position:0% +energy is to the depth of the potential +and this is your famous constant Z + + align:start position:0% +and this is your famous constant Z + + + align:start position:0% +and this is your famous constant Z +naught so e over V naught is actually + + align:start position:0% +naught so e over V naught is actually + + + align:start position:0% +naught so e over V naught is actually +equal to X I over Z naught squared and + + align:start position:0% +equal to X I over Z naught squared and + + + align:start position:0% +equal to X I over Z naught squared and +this is something just to keep in mind + + align:start position:0% +this is something just to keep in mind + + + align:start position:0% +this is something just to keep in mind +if you know sy you certainly must know + + align:start position:0% +if you know sy you certainly must know + + + align:start position:0% +if you know sy you certainly must know +Zeno + + align:start position:0% +Zeno + + + align:start position:0% +Zeno +because that's not your potential and + + align:start position:0% +because that's not your potential and + + + align:start position:0% +because that's not your potential and +then you know how much is the energy all + + align:start position:0% +then you know how much is the energy all + + + align:start position:0% +then you know how much is the energy all +very convenient things so punchline for + + align:start position:0% +very convenient things so punchline for + + + align:start position:0% +very convenient things so punchline for +solutions + + align:start position:0% + + + + align:start position:0% + +so what do we have we have two equations + + align:start position:0% +so what do we have we have two equations + + + align:start position:0% +so what do we have we have two equations +this equation maybe should be given a + + align:start position:0% +this equation maybe should be given a + + + align:start position:0% +this equation maybe should be given a +number sy equal eight at an ADA and ADA + + align:start position:0% +number sy equal eight at an ADA and ADA + + + align:start position:0% +number sy equal eight at an ADA and ADA +an X I squared will giving you Z squared + + align:start position:0% +an X I squared will giving you Z squared + + + align:start position:0% +an X I squared will giving you Z squared +so how do we solve it we solve it + + align:start position:0% +so how do we solve it we solve it + + + align:start position:0% +so how do we solve it we solve it +graphically we have side Anita and then + + align:start position:0% +graphically we have side Anita and then + + + align:start position:0% +graphically we have side Anita and then +we say oh let's try to plot the two + + align:start position:0% +we say oh let's try to plot the two + + + align:start position:0% +we say oh let's try to plot the two +equations well this is a circle in a + + align:start position:0% +equations well this is a circle in a + + + align:start position:0% +equations well this is a circle in a +square plus I squared now cyanate that + + align:start position:0% +square plus I squared now cyanate that + + + align:start position:0% +square plus I squared now cyanate that +must be positive so we look at solution + + align:start position:0% +must be positive so we look at solution + + + align:start position:0% +must be positive so we look at solution +just in this quadrant let's put here PI + + align:start position:0% +just in this quadrant let's put here PI + + + align:start position:0% +just in this quadrant let's put here PI +over 2 pi 3 PI over 2 2 pi + + align:start position:0% +over 2 pi 3 PI over 2 2 pi + + + align:start position:0% +over 2 pi 3 PI over 2 2 pi +and here is a 2 and there is sorry well + + align:start position:0% +and here is a 2 and there is sorry well + + + align:start position:0% +and here is a 2 and there is sorry well +this is a circle as we said but let's + + align:start position:0% +this is a circle as we said but let's + + + align:start position:0% +this is a circle as we said but let's +look at this sign equal in Turton ADA + + align:start position:0% +look at this sign equal in Turton ADA + + + align:start position:0% +look at this sign equal in Turton ADA +that vanishes as a that goes to 0 and + + align:start position:0% +that vanishes as a that goes to 0 and + + + align:start position:0% +that vanishes as a that goes to 0 and +will diverge at ETA equal PI over 2 so + + align:start position:0% +will diverge at ETA equal PI over 2 so + + + align:start position:0% +will diverge at ETA equal PI over 2 so +this part at least look like this and + + align:start position:0% +this part at least look like this and + + + align:start position:0% +this part at least look like this and +then it will go negative which we don't + + align:start position:0% +then it will go negative which we don't + + + align:start position:0% +then it will go negative which we don't +care from this region and then reach + + align:start position:0% +care from this region and then reach + + + align:start position:0% +care from this region and then reach +here at PI and after pi it will go + + align:start position:0% +here at PI and after pi it will go + + + align:start position:0% +here at PI and after pi it will go +positive again and it will reach another + + align:start position:0% +positive again and it will reach another + + + align:start position:0% +positive again and it will reach another +infinity here and then our at 3 pi a 2 + + align:start position:0% +infinity here and then our at 3 pi a 2 + + + align:start position:0% +infinity here and then our at 3 pi a 2 +pi it will go again and reach another so + + align:start position:0% +pi it will go again and reach another so + + + align:start position:0% +pi it will go again and reach another so +these are this curves and the other + + align:start position:0% +these are this curves and the other + + + align:start position:0% +these are this curves and the other +curve the circle is just a circle here + + align:start position:0% +curve the circle is just a circle here + + + align:start position:0% +curve the circle is just a circle here +so for example I could have + + align:start position:0% +so for example I could have + + + align:start position:0% +so for example I could have +a circle like this so the radius of this + + align:start position:0% +a circle like this so the radius of this + + + align:start position:0% +a circle like this so the radius of this +circle is radius V naught and there you + + align:start position:0% +circle is radius V naught and there you + + + align:start position:0% +circle is radius V naught and there you +go you've solved the problem at least + + align:start position:0% +go you've solved the problem at least + + + align:start position:0% +go you've solved the problem at least +intuitively you'd know the answer and + + align:start position:0% +intuitively you'd know the answer and + + + align:start position:0% +intuitively you'd know the answer and +there's a lot of things that come out of + + align:start position:0% +there's a lot of things that come out of + + + align:start position:0% +there's a lot of things that come out of +this calculation if the radius Z naught + + align:start position:0% +this calculation if the radius Z naught + + + align:start position:0% +this calculation if the radius Z naught +is 3 PI over 2 for example and the + + align:start position:0% +is 3 PI over 2 for example and the + + + align:start position:0% +is 3 PI over 2 for example and the +radius Li not represents some potential + + align:start position:0% +radius Li not represents some potential + + + align:start position:0% +radius Li not represents some potential +of some depth and width there will be + + align:start position:0% +of some depth and width there will be + + + align:start position:0% +of some depth and width there will be +just two solutions these are these + + align:start position:0% +just two solutions these are these + + + align:start position:0% +just two solutions these are these +solutions this points represent values + + align:start position:0% +solutions this points represent values + + + align:start position:0% +solutions this points represent values +of sy and values of ADA from which you + + align:start position:0% +of sy and values of ADA from which you + + + align:start position:0% +of sy and values of ADA from which you +can read the energy in fact you can look + + align:start position:0% +can read the energy in fact you can look + + + align:start position:0% +can read the energy in fact you can look +at this state and say that's a state of + + align:start position:0% +at this state and say that's a state of + + + align:start position:0% +at this state and say that's a state of +largest song sy and therefore it's the + + align:start position:0% +largest song sy and therefore it's the + + + align:start position:0% +largest song sy and therefore it's the +state of largest absolute value of the + + align:start position:0% +state of largest absolute value of the + + + align:start position:0% +state of largest absolute value of the +energy it's the most deeply bound state + + align:start position:0% +energy it's the most deeply bound state + + + align:start position:0% +energy it's the most deeply bound state +then this is the next neatly bouncing + + align:start position:0% +then this is the next neatly bouncing + + + align:start position:0% +then this is the next neatly bouncing +there's two bound States in this case + + align:start position:0% +there's two bound States in this case + + + align:start position:0% +there's two bound States in this case +interestingly however shallow this + + align:start position:0% +interestingly however shallow this + + + align:start position:0% +interestingly however shallow this +potential might be however small Z + + align:start position:0% +potential might be however small Z + + + align:start position:0% +potential might be however small Z +naught the circle will always have one + + align:start position:0% +naught the circle will always have one + + + align:start position:0% +naught the circle will always have one +intersection so there will always be at + + align:start position:0% +intersection so there will always be at + + + align:start position:0% +intersection so there will always be at +least one solution that's the end of + + align:start position:0% +least one solution that's the end of + + + align:start position:0% +least one solution that's the end of +that story let me say that for the odd + + align:start position:0% +that story let me say that for the odd + + + align:start position:0% +that story let me say that for the odd +case of solutions + + align:start position:0% +case of solutions + + + align:start position:0% +case of solutions +I will not solve it it's a good thing to + + align:start position:0% +I will not solve it it's a good thing to + + + align:start position:0% +I will not solve it it's a good thing to +do in recitation or as part of the + + align:start position:0% +do in recitation or as part of the + + + align:start position:0% +do in recitation or as part of the +homework as well the answer for the odd + + align:start position:0% +homework as well the answer for the odd + + + align:start position:0% +homework as well the answer for the odd +case is that X I is equal to minus 8 + + align:start position:0% +case is that X I is equal to minus 8 + + + align:start position:0% +case is that X I is equal to minus 8 +that cop ADA and in that case I'll give + + align:start position:0% +that cop ADA and in that case I'll give + + + align:start position:0% +that cop ADA and in that case I'll give +you a little preview of how this cut + + align:start position:0% +you a little preview of how this cut + + + align:start position:0% +you a little preview of how this cut +looks it looks like this and then there + + align:start position:0% +looks it looks like this and then there + + + align:start position:0% +looks it looks like this and then there +more branches + + align:start position:0% +more branches + + + align:start position:0% + +so for the odd solution you have this + + align:start position:0% +so for the odd solution you have this + + + align:start position:0% +so for the odd solution you have this +curves and if you have a circle + + align:start position:0% +curves and if you have a circle + + + align:start position:0% +curves and if you have a circle +sometimes you don't have a solution no + + align:start position:0% +sometimes you don't have a solution no + + + align:start position:0% +sometimes you don't have a solution no +it doesn't intersect this so this are + + align:start position:0% +it doesn't intersect this so this are + + + align:start position:0% +it doesn't intersect this so this are +solutions you will see and try to + + align:start position:0% +solutions you will see and try to + + + align:start position:0% +solutions you will see and try to +understand they don't always success you + + align:start position:0% +understand they don't always success you + + + align:start position:0% +understand they don't always success you +need a potentially sufficiently deep to + + align:start position:0% +need a potentially sufficiently deep to + + + align:start position:0% +need a potentially sufficiently deep to +get an art solution and then the odds + + align:start position:0% +get an art solution and then the odds + + + align:start position:0% +get an art solution and then the odds +and even solutions will interweave each + + align:start position:0% +and even solutions will interweave each + + + align:start position:0% +and even solutions will interweave each +other and there will be a nice story + + align:start position:0% +other and there will be a nice story + + + align:start position:0% +other and there will be a nice story +that you will explore in a lot of detail + + align:start position:0% +that you will explore in a lot of detail + + + align:start position:0% +that you will explore in a lot of detail +but the lesson is if we use the problem + + align:start position:0% +but the lesson is if we use the problem + + + align:start position:0% +but the lesson is if we use the problem +the unique free calculation in which you + + align:start position:0% +the unique free calculation in which you + + + align:start position:0% +the unique free calculation in which you +can get the nutrition of when solutions + + align:start position:0% +can get the nutrition of when solutions + + + align:start position:0% +can get the nutrition of when solutions +exist and when they don't but solving + + align:start position:0% +exist and when they don't but solving + + + align:start position:0% +exist and when they don't but solving +for the particular numbers are + + align:start position:0% +for the particular numbers are + + + align:start position:0% +for the particular numbers are +transcendental equations and you need a + + align:start position:0% +transcendental equations and you need a + + + align:start position:0% +transcendental equations and you need a +computer to solve \ No newline at end of file diff --git a/kAv5pahIevE.txt b/kAv5pahIevE.txt new file mode 100644 index 0000000000000000000000000000000000000000..8744ffd63e94971047a22717fb1ceec07292aaaa --- /dev/null +++ b/kAv5pahIevE.txt @@ -0,0 +1,1451 @@ +PROFESSOR: OK. + +I promised a video about +limits and continuous + +functions and here it is. + +So I'll begin with the most +basic idea and with a picture + +instead of definition in symbols +first. So the most + +basic idea is that I have +a bunch of numbers-- + +let's make them positive +numbers-- + +and I want to know, what +does it mean for them + +to approach a limit-- + +capital A-- + +as I go out this sequence of +numbers, a1, a2, a3, a4. + +And let me say right away, the +first four numbers, the first + +million numbers, make no +difference about the limit. + +So here's what it means. + +For example, there's a +equals 7, let's say. + +What does it mean for these +numbers to approach 7? + +It means that if I take any thin +little space around a, + +above and below, the numbers +can start out whatever. + +They can go in there, they could +go out, they could come + +back, whatever, they could +grow way big, way small. + +But in the end, beyond some +point, eventually, they have + +to get in that slit +and stay in there. + +And the slit, then, +could be smaller. + +And then they would have to get +into that smaller slit and + +stay there. + +So that's what it means for +the numbers to approach A, + +that eventually after any number +of jogs around, they + +get inside and they stay +there, however + +thin that slit is. + +A slight difference when +a is 0, because + +the numbers are positive. + +They're coming down, +they get in. + +And again, they must stay in. + +And then, again, I'm going to +make the band tighter, and + +they have to get into +that and stay there. + +And what does it mean for the +numbers to approach infinity? + +That means that whatever-- + +so this is often +called epsilon. + +I'll use that Greek +letter epsilon as + +a very small number. + +So this would be A minus +epsilon, and this would be A + +plus epsilon. + +And then the epsilon could +be made smaller. + +And now here is some +big number, + +like even 1 over epsilon. + +So that's a giant number. + +And the limit is infinity if, +again, they can dodge around + +for a while, they can go +down, they can go up. + +But eventually, they +must get above that + +line and stay there. + +And if I move the line up +further, they have to get + +above that line for me to +say that the limit is-- + +so I have these possible +limits. + +Infinite, some positive, +ordinary number, and 0. + +Those are possible limits. + +But of course many sequences +have no limit at all, like + +sine of n, it will just bounce +around, cosine n-- + +many, many things. + +OK. + +So I think that the way to get +the idea, use the idea, is to + +ask some questions +about limits. + +And we'll see that usually the +answer is yes, OK, no problem. + +But once in a while, for certain +limits are dangerous. + +So really always mathematicians +are looking for + +what's special, what unusual +thing could happen? + +Because the truth is, limits are +ordinarily rather boring. + +If the an's approach 7 and the +bn's approach 4, so the a's + +get close to 7 and the b's get +close to 4, then their + +differences will get +close to 7 minus 4. + +But is there any case in +which that could fail? + +Is there any case among these +in which we could not know + +what the limit was, and it might +not exist, or it might + +be like any number? + +And I think that can happen +in this, so I've got four + +different questions +here, getting more + +interesting as we go down. + +In the first one, I can +see only one problem. + +If the a's approach infinity, so +they get very big, and the + +b's also approach infinity, get +very big, so capital A and + +capital B become formally +infinity minus infinity, and + +we don't know the +answer there. + +That has no meaning. + +So this'll be my little +list of danger. + +I mean, it's not like +skydiving, but for a + +mathematician this +is high risk. + +OK, so how could this happen? + +Well, the an might +be n squared. + +And the bn might be only n. + +Right? + +So they're both going to +infinity, n squared and n. + +But n squared is going faster. + +It's like a race. + +n squared will win, and the +difference between them will + +actually grow faster +and faster. + +Or they could go to +infinity together. + +an and bn could both be n, +both headed for infinity. + +The differences would be +0 all along, n minus n. + +So the limit of the difference +would be 0 minus 0. + +So this could be 0, but it could +be infinity, it could be + +minus infinity, it could +be anything. + +Any limit is possible there. + +Do you see that there +is a case-- + +it's sort of a special case, +because it only happens when + +these limits are infinite-- + +but now it's sort of OK +to look at each-- + +let me look at number two. + +How about multiplication? + +If I multiply a bunch of numbers +that are headed for 7 + +and a bunch of numbers that +are headed for 4, their + +product is going +to head for 28. + +This will be true. + +When could it fail? + +Well, again, it's going to be +extreme cases, because if I + +have ordinary numbers for +A and B like 7 and + +4, there's no doubt. + +But look at the extreme +case of when A + +is 0 and B is infinite. + +So the an's are headed for 0. + +The bn's are getting bigger +and bigger, the an's are + +getting small as we +go far enough out. + +OK. + +In that case, well, +again it's a race. + +The an's might be 1 over +n squared, and the + +bn's might be n. + +So this would be n over +n squared, and + +that would go to 0. + +But if I reverse those I could +have n squared times 1 over n. + +The product could get bigger, +or the product could-- + +all possibilities. + +All possibilities there. + +So I cannot know what +that one is. + +0 times infinity +is meaningless. + +OK. + +What about number three? + +The danger increases as soon +as we start dividing. + +I made the b's positive, +but I don't know if + +capital B is positive. + +So the danger-- + +and, in fact, the most important +case for calculus-- + +is 0 over 0. + +If the a's go to 0 and the b's +go to 0, I can't tell what + +their ratio goes to, because it +depends how fast they go. + +If the a's go quickly to 0 and +the b's are rather slow + +getting there-- + +in other words the b's would be +a lot bigger than the a's + +even though both are +going to 0-- + +then that fraction +would be small. + +But if I reverse them, the +fraction would be large. + +So I think 0 over +0 is a danger. + +I think there's another +danger here. + +Yeah, maybe infinity +over infinity. + +Again, that's a race that we +can't tell, until we know + +details about the sequences, +who's going to win. + +If they an's go off to infinity +and the bn's go off + +to infinity, ah, a very +important case. + +The ratio could be +1 all along. + +The a's and b's could be the +same, headed for infinity. + +Or the an's might be squaring +the b's and going up faster, + +or the square root of the +b's and going slower. + +So again, infinity over +infinity, we can't-- + +0 over infinity, if the a's are +headed for 0 and the b's + +are headed big, then that ratio +is going to be small and + +head for 0. + +0 over infinity, I'm OK with. + +Call it 0. + +Well, I don't know if +that's legal, but + +anyway, let me do it. + +All right, last one of +this kind, just for + +practice about limits. + +Again, you see what I'm +constantly doing is thinking + +of examples that simply +show that I can't + +be sure of the limit. + +So here normally I could be +sure, if this is headed for 7 + +to the fourth, that'll be the +limit, whatever that is, 49 + +squared, 2401, or something. + +But if-- + +now when could it go wrong? + +Here's an interesting case. + +So this is my list of danger, +and I think I'm in danger if + +they both go to 0. + +0 to the 0-th power, I don't +know what that is. + +And actually, I don't know all +the possibilities here. + +I can see one way would be let's +suppose the b's were + +actually 0, or practically. + +Then things to the +0 power are 1. + +So I could get the answer 1 here +by fixing the b's at 0 + +and letting these guys, they +would all be to the 0 power, + +so they would all be 1. + +And in the limit, +I would have 1. + +But I could also do +it differently. + +I could fix these at 0 and let +these guys get smaller. + +Then I would have 0 to powers. + +And zero to any power is 0. + +You see my little +problem here? + +Let me write my little +problem here. + +My problem is that a to the 0 +power would be 1, but 0 to the + +a-th power would be 0, or 0 to +the b-th, maybe I should say. + +So if I'm in this situation and +the a is shrinking to 0, I + +still have a limit of 1's. + +But if I'm in this situation and +the b's are headed for 0, + +I have a limit of 0's. + +And maybe you could get +1/2, I don't know how. + +And you have to allow me-- +because I have to finish this + +list, and I only have one +more to tell you-- + +that another case, a very +interesting type of calculus + +case is the case where +the a's go to 1 and + +the b's go to infinity. + +I don't know if you remember +that this actually happened in + +the lecture on e, the number +that comes in e to the x, the + +great number of calculus. + +Do you remember that? + +So I'm going to talk a little +bit about the a's going to 1 + +and the b's blowing up. + +So I'm getting things that are +very near 1, but I'm taking + +many, many more of them. + +And I believe that I can +get all kinds of + +different limits there. + +I believe I can get all kinds +of different limits. + +Do you just-- + +maybe on this next board. + +And then I promise to come +back to the heart of the + +subject of limits and continuous +functions. + +But I just think that one, the +famous case of this one, was 1 + +plus 1 over n. + +That's the a's, and that +approaches what limit? + +One. + +The b's I'm going +to take as n. + +So the b's are going +to infinity. + +So I'm discussing +this case here. + +So that's a case where +this goes to 1, + +this goes to infinity. + +I had an email this week saying, +wait a minute, I've + +got a little problem here, +because I know 1 to the + +infinity is e. + +1 to the infinity is 3. + +Well, that's because it's true +that that number approaches e. + +That's one of the many +remarkable ways to produce the + +number e, the 2.7-something. + +But that's because the race +between this and this was so + +evenly balanced. + +If I took these closer and +closer to 1, like n squared, + +what would happen then? + +Then I'm taking numbers very, +very near 1, I'm taking a + +power, but these are sort of +near, those would approach-- + +would you like to guess? + +One. + +These are so close to 1 that +taking the nth power doesn't + +move them far. + +And you can guess that I could +get infinity too, by taking n + +not still close to 1 +and taking some big + +power like n squared. + +Now I have things close to 1, +but I'm taking so many of them + +that it would blow up. + +So again i think--So those are +all cases where in the limit, + +I have 1, in the limit, +I have infinity. + +But that combination 1 to the +increasingly high powers can + +do different things. + +This was my little idea to +show you the risky cases. + +OK. + +But actually, 0 over 0, that's +what calculus is + +always doing, right? + +Because that's exactly what we +have when we have a delta f + +over a delta x, a delta +y over a delta x. + +They're both approaching 0 and +we get a definite slope when + +the ratio goes to +a good number. + +OK. + +So can I discuss 0 over 0? + +All right, phooey on this one. + +OK. + +So I now want to speak +about the case when f + +of x goes to 0. + +Let's say f of x goes +to 0 as x goes to 0. + +So there'll be an if here. + +I have to say what that means. + +And then I'm also going to have +some g of x going to 0 as + +x goes to 0. + +OK, so both functions +are decreasing. + +And my question, let me ask the +question first, what about + +f of x over g of x? + +What does that do? + +And of course, just as I said +up there, I can't tell yet. + +I have to know the +f and the g. + +It's a race to 0, and I have to +know who's the winner and + +by how much. + +But first, I'd better say what +does it mean for a function to + +go to 0 as x goes to 0. + +Well, you know. + +Let me draw a graph +of this function. + +OK, I'll just draw it. + +So f of x is going to 0. + +So here is x, and I'm going to +graph f of x, and here is 0. + +So as x is coming down to 0, my +f of x is also coming to 0. + +So it could come like so. + +That's a pretty sensible, +smooth, nice approach to 0. + +That could be my f of x. + +And it may be a g of x is +smaller, but also approaching + +0 in a nice, smooth way. + +This is a case where +you can see those, + +as x goes that way-- + +maybe the arrow should be going +that way, because x is + +going to 0-- + +my f of x is getting smaller, my +g of x is getting smaller. + +And I'll say exactly what +that means, but you + +know what it means. + +It means that if I put a little, +like these lines, if I + +put a little band there, +it gets into that band. + +Actually, g will get into +the band sooner. + +But then f will safely +get into the band. + +Now, the question is what about +f of x over g of x? + +OK. + +Can we say? + +Now, I'm going to suppose +that f of x has a + +definite slope, s. + +And this one has a definite +slope, t. + +In other words, I am +going to suppose-- + +Here look, this is called, +named after a French guy, + +L'Hopital, the hospital rule. + +OK, so it's just a little trick, +because this comes up + +of what's happening +in this race to 0. + +And the natural idea is that f +of x is really, since f is 0 + +there, and I'm really just +going a little way. + +So maybe I call that delta x, +just to emphasize that I'm + +looking really near 0. + +And that f of x is really +going to be delta f. + +And that g of x is really going +to be delta g, because + +let me draw the picture, +delta f is that height. + +Here is delta x, and +here is the height. + +It's because that +point is 0, 0. + +So the differences I'm taking, +the f of x in the delta, the f + +of x plus delta x is just f at +delta x, just that height. + +And g is this smaller one. + +Do you have an idea of what +this answer's going to be? + +If I look at that ratio of this + +function to this function-- + +here the ratio, I don't know +what, 3 or something. + +Here it's, I don't know, +maybe 4, maybe more. + +As I'm getting closer and +closer, this height is + +controlled by the slope. + +And this height, the g of x, +is controlled by its slope. + +Look, here is the +way to see it. + +Just divide top and +bottom by delta x. + +Same thing. + +So I haven't changed +anything yet. + +I divided the top and the +bottom by delta x, just + +because now I'll let everything +go to 0, delta x + +will go to 0, the delta f will +go to 0, so the delta + +g will go to 0. + +But I know what this +approaches. + +Delta f over delta x approaches +the slope, s. + +And delta g over delta x +approaches the other slope, t. + +So you see, this is L'Hopital's +rule, that if f + +goes to 0, and if g goes to 0, +and if they have nice slopes, + +then the ratio of f to g, which +looks like 0 over 0, we + +can actually tell what it is by +looking at the derivative, + +by looking at those slopes. + +It's the ratio of the slopes. + +OK, that takes a little +thought and, of + +course, some practices. + +It also takes some examples to +show what else could happen. + +Can I just draw another f, +and you tell me what + +about f over g. + +I'm sorry to give you all these +questions, but it's + +example, answer, that you +get the hang of slopes. + +Suppose f goes much steeper. + +I mean, f could be the +square root of x. + +There's f equal the +square root of x. + +Square root of x has an +infinite slope at 0. + +It's a good function to know, +the square root of x, because + +this is x to the 1/2 power. + +And its derivative, its slope, +we know will be 1/2 x to the + +minus 1/2 power. + +And then as x goes to +0, that blows up the + +way the picture shows. + +Now, what would f over g, so +this is a case where f hasn't + +got a slope. + +The slope is infinite now. +s is now infinite. + +And that ratio is going +to blow up. + +This one is getting +to 0 but slowly. + +This f is staying much bigger +than the g, and the ratio + +would be infinite. + +So there's a case where +L'Hopital can't help because + +f, this slope s, which was fine +for this nice function, + +is not fine for this function. + +The slope is infinite for that +square root function. + +OK, a bunch of examples that +begin to show what can happen + +and the need, really, for a +little bit of care on what + +does it mean? + +What would I say about that +square root function? + +So I'll even write +that down here. + +f of x equals square root +of x at x equals 0. + +What would I say about +that function that + +we know it's picture? + +I would say it has +infinite slope. + +Or if you prefer, its slope +is not defined. + +We don't have a good number +there for its slope. + +But I would still say the +function is continuous because + +the darn thing does get +below any band. + +If I draw a little band here, +the function does get into + +that band and stay inside. + +It just took a long time. + +It stayed out of that band as +long as it could and then + +finally fell in just +at the last minute. + +OK, so I would say this function +has the slope not + +defined, not OK at x equals 0. + +But f of x is continuous +at x equals 0. + +So I'm trying to make the +distinction between asking for + +the function to be continuous +is not asking as much. + +If a function's got a nice +slope, like g, that function's + +got to be continuous. + +And more, it has to have +this good slope. + +This f of x, this square root +function will be continuous. + +And now I have to tell you +what continuous means. + +It's not asking for so much as +a slope, because the slope + +could come down infinitely +at the last minute. + +All right, so what's a +continuous function? + +Continuous function means-- + +a continuous function, f of x, +at some point-- maybe here it + +was 0, I'd better allow +any old point. + +So in words, it means f of +x approaches f of a as x + +approaches a. + +That's what it means to be +continuous at that point. + +It means that there is +a number, a value + +for f at that point. + +And we approach that value as +we get near that point. + +That seems such a +natural idea. + +That's what it means for a +function to be continuous. + +And with this piece of chalk +or with your pen, it means + +that I can draw the function +without lifting my pen. + +Of course, it could do +some weird stuff. + +OK, let me just draw here. + +So here's a point, a, and here +is my function, f, and + +there is f of a. + +So I'm saying that the function +could come along, it + +could come down pretty steeply, +but it will get to + +that point. + +It might go on, steeper below, +or it might turn back. + +Or it might be level. + +But I can draw the whole +thing continuously. + +But now that description +with a piece of + +chalk isn't quite enough. + +And there's a formal definition + +that I have to explain. + +And it involves this same +idea of epsilon, this + +same idea of a strip. + +It means that if I take a little +strip around f of a-- + +so here's f of a plus a little +bit, and here's f of a minus a + +little bit-- + +then that's continuous. + +That function is continuous, +because-- + +now, remember, epsilon could +be smaller than I drew it, + +smaller than I can draw it, +but still positive. + +Then the requirement is that it +has to get near a, it has + +to get inside that band +and stay there. + +It can bounce all +over the place. + +But near the point, it's +got to get close. + +And now, how do I express that +in terms of epsilon? + +OK, well, there's a famous +description. + +Yeah, what do I mean by get in +there and stay in there? + +Ah! + +Can I just make a story? + +I'm going to use two Greek +letters, epsilon and delta, + +hated by all calculus students +and professors + +too, if they're truthful. + +OK, so the story goes, +we choose a band. + +Ah, since their Greek letters, +Socrates chooses epsilon. + +OK. + +So he's going to make it hard. + +He's going to make a +narrow band there. + +And then the function has got to +get into that band and stay + +there, close to a. + +OK, so what do I mean +by close to a? + +Well, that's where +delta comes in. + +That's, let's say, Socrates's +student, Plato. + +Then Plato can pick his number, +delta, which will be + +the width-- + +see, he says, OK, if you get +really close, I've got you. + +So he's trying to +please Socrates. + +So he says, woo, sorry, a had +better be in there somewhere. + +Now these bands are getting so +close, my a is, of course-- + +this is really a plus delta, and +this guy is a minus delta. + +Are you kind of with me? + +The logic goes, for any epsilon +chosen by Socrates, + +Plato can find a positive +delta-- + +epsilon, of course, was some +positive number, delta might + +be an extremely small +positive number-- + +so that if the distance +to a is smaller + +than Plato's distance-- + +so if we're in that +vertical band-- + +then we're in Socrates's +horizontal band. + +Then this f of x minus f +of a is below epsilon. + +So Socrates sets up any tough +requirement, any horizontal + +band, and then Plato meets +that requirement, if the + +function is continuous, by +choosing a vertical band that + +keeps everything inside +Socrates's band. + +Do you see that? + +Well, it takes some thought. + +It takes some practice, and as +always, it's not usually very + +hard to tell if a function +is continuous. + +Let me show you one +that isn't. + +A famous function that +is not continuous. + +Here's the sine of 1 over +x as x going to 0. + +What happens to the sine of +1 over x when x goes to 0? + +Well, the sine, we know, +oscillates minus 1, plus 1, + +minus 1, plus 1. + +But when it's a sine of 1 over +x, that oscillation really + +takes off, because if x gets +small, 1 over x is quickly + +getting larger. + +You're running along the sine +curve in a faster and faster + +and faster way. + +I can't draw it. + +Here's 0. + +But it's not staying +inside a band. + +Even with epsilon equalling 1/2, +Socrates has got Plato. + +Plato can't keep it in a band of +1/2 up and 1/2 down because + +the sine doesn't stay there. + +So there's a function that's +not continuous. + +I could make it continuous by +changing the function a + +little, maybe x times +sine of 1 over x. + +That would bring the +oscillations down and work. + +So there you go. + +That's epsilon and delta. + +And it takes a little +practice. + +And I just have to remember-- + +when you feel that the whole +thing is a bad experience-- + +some pity for a Socrates, who +actually took poison. + +Not because Plato gave him one +that he couldn't do, for some + +completely different reason. + +But this is the meaning of a +continuous function, and by + +getting that meaning which took +hundreds of years to see. + +And it takes some time to get +these two different things, to + +get the logic straight. + +If x is close to a, then f +of x is close to f of a. + +That's what this means, f +of x approaching f of a. + +That's what Socrates and Plato +together had to explain. + +OK, thank you. + +ANNOUNCER: This has been +a production of MIT + +OpenCourseWare and +Gilbert Strang. + +Funding for this video was +provided by the Lord + +Foundation. + +To help OCW continue to provide +free and open access + +to MIT courses, please +make a donation at + +ocw.mit.edu/donate. \ No newline at end of file diff --git a/kUN6rJ21Hno.txt b/kUN6rJ21Hno.txt new file mode 100644 index 0000000000000000000000000000000000000000..04f349bc60d11265337224f215dbb8879a4a527a --- /dev/null +++ b/kUN6rJ21Hno.txt @@ -0,0 +1,4317 @@ +The following +content is provided + +under a Creative +Commons license. + +Your support will help MIT +OpenCourseWare continue + +to offer high quality +educational resources for free. + +To make a donation or +view additional materials + +from hundreds of MIT courses, +visit MIT OpenCourseWare + +at ocw.mit.edu. + +PROFESSOR: All right. + +We should probably get started. + +So RNA plays important +regulatory and catalytic roles + +in biology, and so it's +important to understand + +its function. + +And so that's going to be the +main theme of today's lecture. + +But before we get +to that, I wanted + +to briefly review what +we went over last time. + +So we talked about hidden +Markov models, some + +of the terminology, thinking +of them as generative models, + +terminology of the different +types of parameters, + +the initiation probabilities +and transition probabilities + +and so forth. + +And Viterbi algorithm, just +sort of the core algorithm + +used whenever you apply HMMs. + +Essentially, you always +use the Viterbi algorithm. + +And then we gave as an +example the CpG Island HMM, + +which is admittedly a +bit of a toy example. + +It's not really +used in practice, + +that illustrates the principles. + +And then today we're going +to talk about a couple + +of real world HMMs. + +But before we get +to that, I just + +wanted to-- sort +of toward the end, + +we talked about the +computational complexity + +of the algorithm, and concluded +that if you have a case state + +HMM run on a sequence of length +L, it's order k squared L. + +And this diagram is helpful +to many people in sort + +of thinking about that. + +So you can have transitions +from any state-- + +for example, from this state-- +to any of the other five + +states, and there's +five-state HMM. + +And when you're +doing the Viterbi, + +you have to maximize over the +five possible input transitions + +into each state. + +And so the full +set of computations + +that you have to do from going +from position i to i plus 1 + +is k squared. + +Does that make sense? + +And then there's L different +transitions you have to do, + +so it's k squared L. + +Any questions about that? + +OK. + +All right and, so the example +that we gave is shown here. + +And what we did was to take an +example sort of where you could + +sort of see the answer-- +not immediately see it, + +but if we're thinking about it +a little, figure out the answer. + +And then we talked about how +the Viterbi algorithm actually + +works, and why it makes the +transitions at the right place. + +It seems to intuitively like it +would make a transition later, + +but actually transitions +at the right place. + +And one way to +think about that is + +that these are not hard and +fast decisions because you're + +optimizing two different paths. + +At every state, you're +considering two possibilities. + +And so you explore the +possibility of-- the first time + +you hit a c, you explore the +possibility of transitioning + +from genome to +island, but you're not + +confirming whether you're going +to do that yet until you get + +to the end and see whether that +path ends up having a higher + +probability at the end of the +sequence than the alternative. + +So that's sort of one way +of thinking about that. + +Any questions about +this sort of thing, + +how to understand when a +transition will be made? + +And I want to emphasize, +for this simple HMM, + +we talked about +you can kind of see + +what the answer's going to be. + +But if you have any HMM, any +sort of interesting real world + +HMM with multiple +states, there's + +no way you're going +to be able to see it. + +Maybe you could guess +what the answer might be, + +but you're not going to be able +to be confident of what that + +is, which is why you have +to actually implement it. + +All right, good. + +Let's talk about a couple +of real world HMMs. + +So I mentioned gene finding. + +That's been a popular +application of HMMs, + +both in prokaryotes +and eukaryotes. + +There's some examples +discussed in the text. + +Another very popular application +are so-called profile HMMs. + +And so this is a +hidden Markov model + +that's made based on a multiple +alignment of proteins which + +have a related function +or share a common domain. + +For example, there's +a database called + +Pfam, which includes +profile HMMs for hundreds + +of different types +of protein domains. + +And so once you have many +dozens or hundreds or thousands + +of examples of a +protein domain, you + +can learn lots of +things about it-- + +not just what the +frequencies of each residue + +are in each position, +but how likely + +you are to have an +insertion at each position. + +And if you do have +an insertion, what + +types of amino acid residues +are likely to be inserted + +in that position, +and how often you + +are likely to have a +deletion at each position + +in the multiple alignment. + +And so the challenge then +is to take a query protein + +and to thread it through all +of these profile HMMs and ask, + +does it have a significant +match to any of them? + +And so that's basically +how Pfam works. + +And the nice thing about +HMMs is that they allow you + +to-- if you want to have +the same probability + +of an insertion at each position +in your multiple alignment, + +you can do that. + +But if you have enough data +to observe that there's + +a five-fold higher likelihood of +having an insertion at position + +three in a multiple alignment +than there is at position two, + +you can put that in. + +You just change +those probabilities. + +So in this HMM, each +of the hidden states + +is either an M state, which is +a match state, or an I state, + +or an insert state. + +And so those will emit +actual amino acid residues. + +Or it could be a +delete state, which + +is thought of as emitting +a dash, a placeholder + +in the multiple alignment. + +So these are also widely used. + +And then one of my favorite +examples-- it's fairly simple, + +but it turns out to +be quite useful-- + +is the so-called +TMHMM for prediction + +of transmembrane +helices in protein. + +So we know that many, +especially eukaryotic proteins, + +are embedded in membranes. + +And there's one famous family +of seven transmembrane helix + +proteins, and there +are others that + +have one or a few +transmembrane helices. + +And knowing that a protein +has at least one transmembrane + +helix is very useful in terms +of predicting its function. + +You predict it's localization. + +And knowing that it's a seven +transmembrane helix protein + +is also useful. + +And so you want to predict +whether the protein has + +transmembrane helices and +what their orientation is. + +That is, proteins can +have their end terminus + +either inside the cell +or outside the cell. + +And then of course, where +exactly those helices are. + +And this program has +about a 97% accuracy, + +according to [? the author. ?] +So it works very well. + +So what properties +do you think-- + +we said before that +you have to have + +strongly different +emission probabilities + +in the different hidden states +to have a chance of being + +able to predict +things accurately. + +So what properties do +you think are captured + +in a model of +transmembrane helices? + +What types of +emission probabilities + +would you when you have for the +different states in this model? + +Anyone? + +So for this protein, +what kind of residues + +would you have in here? + +Oops, sorry. + +I'm having trouble +with this thing. + +All right, here in the +middle of the membrane, + +what kind of residues are +you going to see there? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Those are +going to be hydrophobic. + +Exactly. + +And what about right +where the helix emerges + +from the membrane? + +[INAUDIBLE] charge residue's +there to kind of anchor + +it and prevent it from +sliding back into membrane. + +And then in general, both on +the exterior and interior, + +you'll tend to have more +hydrophilic residues. + +So that's sort of +the basis of TMHMM. + +So this is the structure. + +And you'll notice that these are +not exactly the hidden states + +that correspond to individual +amino acid residues. + +These are like meta +states, just to illustrate + +the overall structure. + +I'll show you the actual +states on the next slide. + +But these were the +types of states + +that the author, Anders +[? Crow ?], decided to model. + +So he has sort of a-- focuses +here on the helix core. + +There's also a cytoplasmic +cap and a non-cytoplasmic cap. + +Oops, didn't mean that. + +And then there's sort of a +globular domain on each side-- + +both on the cytoplasmic +side, or you + +could have one on the +non-cytoplasmic side. + +OK, so there's going to be +different compositions in each + +of these regions. + +Now one of the things we +talked about with HMMs + +is that if you were-- now let's +think about the helix core. + +The simplest model +you might think of + +would be to have sort +of a helix state, + +and then to allow that +state to recur to itself. + +OK, so this type of thing where +you then have some transition + +to some sort of cap state +after, this would allow you + +to model helices of any length. + +But now how long are +transmembrane helices? + +What does that +distribution look like? + +Anyone have an idea? + +There's a certain +physical dimension. + +[INAUDIBLE] + +It takes a certain number +residues to get across here, + +and then that number +is about 20-ish. + +So transmembrane helices +tend to be sort of + +on the order of 20 +plus or minus a few. + +And so it's totally unrealistic +to have a transmembrane helix + +that's, like, five +residues long. + +So if you run this algorithm +in generative mode, + +what distribution of helix +lengths will you produce? + +We're running in +generative mode where + +we're going to let, +remember, to generate + +a series of hidden +states and then + +associated amino acid sequences. + +It's coming from some, +let's say-- I don't know. + +What kind of states are there +here? [INAUDIBLE] plasmic. + +Let's say goes into +helix, hangs out here. + +I'm sorry, is there an +answer to this question? + +Anyone? + +I don't know how +long-- if I let it run, + +it'll generate a random number. + +It depends on what this +probability is here. + +Let's call this probability +p, and then this + +would be 1 minus p. + +OK, so obviously if +1 minus p is bigger, + +it'll tend to produce +longer helices. + +But in general, +what is the shape + +of the distribution there of +consecutive helical states + +that this model will generate? + +AUDIENCE: Binomial. + +PROFESSOR: Binomial. + +OK, can you explain why? + +AUDIENCE: Because +the helix would + +have to have probable-- +the helix of length n + +would occur 1 minus +p to the n power. + +PROFESSOR: OK, so a helix of +length 10 with a probability + +of then, say, let's call it L, +for the length of the helix, + +equals n is 1 minus +p to the n, right? + +Is that binomial? + +Someone else? + +AUDIENCE: Yeah. + +Is it a negative binomial? + +PROFESSOR: Negative binomial. + +OK. + +AUDIENCE: [INAUDIBLE] states and +a helix state before moving out + +[INAUDIBLE]. + +PROFESSOR: Yeah. + +So the distribution is +going to be like that. + +You have to stay in here +for n and then leave. + +So this is the +simplest-- you can + +have special cases of binomial +and negative binomial. + +But in general, +this distribution + +is called the +geometric distribution. + +Or a continuous version would +be the exponential distribution. + +So what is the shape +of this distribution? + +If I were to plot n down here on +this axis, and the probability + +that L equals n on this +axis, what kind of shape-- + +could someone draw in the air? + +So you had up and then down? + +OK, so actually, it's +going to be just down. + +Like that, right? + +Because as n increases, +this goes down + +because 1 minus +p is less than 1. + +So it just steadily goes down. + +And what is the mean +of this distribution? + +Anyone remember this? + +Yeah, so there's sort +of two versions of this + +that you'll see. + +One of them is the 1 minus p +n minus 1 p, and one of them + +is this. + +And so this is the number of +failures before a success, + +if you will. + +Successes lead to the helix. + +And this is the number of +trials till the first success. + +So one of them has +a mean that's 1/p, + +and the other has a mean +that's 1 minus p over p. + +So usually, p is small, and +so those are about the same. + +So 1/p. + +You could think that +1/p is roughly right. + +And so if we were to model +transmembrane helices, + +and if transmembrane +heresies are about-- + +I said about 20 +residues long-- you + +would set p to what value +to get the right mean? + +AUDIENCE: 0.05. + +PROFESSOR: Yeah. + +0.05. + +1/20, so that 1 over that +will be about 20, right? + +And then 1 minus p +would, of course, be 0.9. + +So if I were to do that, +I would get a distribution + +that looks about like +this with a mean of 20. + +But if I were to then look +at real transmembrane helices + +and look at their +distribution, I + +would see something +totally different. + +It would probably +look like that. + +It would have a mean around 20. + +But the probability of anything +less than 15 would be 0. + +That's too short. + +It can't go across the membrane. + +And then again, you don't +have ones that are 40. + +They don't kind of wiggle around +in there and then come out. + +They tend to just +go straight across. + +So there's a problem here. + +You can see that if you want +to make a more accurate model, + +you want to not only get the +right emission probabilities + +with the right probabilities of +hydrophobics and hydrophilics + +and the different +states, but you also + +want to get the length right. + +And so the trick that-- +well, actually, yeah. + +Can anyone think of tricks +to get the right length + +distribution here? + +How do we do better than this? + +Basically, hidden +Markov models where + +you have a state that +will recur to itself, + +it will always be a +geometric distribution. + +The only choice you have is +what is that probability. + +And so you can get +any mean you want, + +but you always get this shape. + +So if you want a +more general shape, + +what are some tricks +that you could do? + +How could you change the model? + +any ideas? + +Yeah, go ahead. + +AUDIENCE: [INAUDIBLE] have +multiple helix states. + +PROFESSOR: Multiple +helix states. + +OK. + +How many? + +AUDIENCE: Proportional to the +length we want, [INAUDIBLE]. + +PROFESSOR: Like one for +each possible length. + +AUDIENCE: It'd be +less than one length. + +PROFESSOR: Or less than one. + +OK. + +So you could have +something like-- I mean, + +let's say you have like this. + +Helix begin-- or, +helix 1, helix 2. + +You allow each of these +to recur to themselves. + +What does that get you? + +This actually gets you +something a little bit better. + +It gives you a little bit +about of-- it's more like that. + +So that's better. + +But if I want to get the exact +distribution, then actually + +one-- so this is the solution +that the authors actually used. + +They made essentially 25 +different helix states, + +and then they allowed various +different transitions here. + +So it's a larger +arbitrary here, but they + +have this special state three +that can kind of take a jump. + +So it can just +continue on to four, + +and that'll make your +maximum length helix core. + +Or it can skip one, go +to five, and that'll + +make a helix core that's one +residue shorter than that, + +or it can skip +two, and so forth. + +And you can set +any probabilities + +you want on these transitions. + +As so you can fit basically +an arbitrary distribution + +within a fixed range +of lengths that's + +determined by how +many states you have. + +OK, so they really wanted to get +the length distribution right, + +and that's what they did. + +What's the cost of this? + +What's the downside? + +Simona? + +AUDIENCE: I was +just going to ask, + +it looks like from +this your minimum helix + +length could be four. + +PROFESSOR: Yeah. + +That's a good question. + +Well, we don't know what +the probabilities-- they say + +said on that. + +Well, did they really mean that? + +And also, that's only the core, +and maybe these cap things + +can be-- yeah, that seems +a little short to me. + +So yeah, I agree. + +I'm not sure. + +It could just be for the +sake of illustration, + +but they don't +actually use those. + +But anyway, I'll probably +have to read the paper. + +I haven't read this +paper for many years + +so I don't remember +exactly the answer to that. + +But I have a citation. + +You can look it up +if you're curious. + +But the main point I +wanted to make with this + +is just that by setting an +arbitrary number of states + +and putting in possible +transitions between them, + +you can actually construct +any length of distribution + +you want. + +But there is a downside, +and what is that downside? + +AUDIENCE: Computational cost. + +PROFESSOR: Yeah, the +computational cost. + +Instead of having +one helix state, + +now we've got 25 or something. + +So and the time goes up by the +square of the number of states, + +so it's going to run slower. + +And you also have to estimate +all these parameters. + +OK, so here's an example +of the output of the TMHMM + +program for a mouse +chloride channel gene, CLC6. + +So the program +predicts that there + +are seven transmembrane +helices, as shown + +by these little red blocks here. + +You can see they're all about +the same-- about 20 or so-- + +and that the program starts +outside and ends inside. + +So let's say you were going +to do some experiments + +on this protein to +test this prediction. + +So one of the types of +experiments people do + +is they put some +sort of modifiable + +or modified residue +into one of the spaces + +between the +transmembrane helices. + +And then you can test, +by modifying this cell + +with something that's a +non-permeable chemical, + +can you modify that protein? + +So only if that stretches +on the outside of the cell + +will you be able to predict it. + +So that's a way of +testing the topology. + +So if you were doing those +types of experiments, + +you might actually-- like +maybe you're not sure + +if every transmembrane +helix is correct. + +There could be some +where the boundaries were + +a little off, or +even a wrong helix. + +And so one of the +things that you often + +want with a +prediction is not only + +to know what is the optimal +or most likely prediction, + +but also how confident +is the algorithm in each + +of the parts of its prediction. + +How confident is it in the +location of transmembrane helix + +three or the probability +that actually there + +is a transmembrane helix three. + +And so the way that this program +does that is using something + +called the +forward-backward algorithm. + +So those of you who read +the Rabener tutorial, + +it's described +pretty well there. + +The basic idea is +that I mentioned + +that this Po-- the probability +of the observable sequence + +summing over all +possible HMM structures + +or all possible sequences +of hidden states-- + +that is possible to calculate. + +And the way that +you do it is you + +run an algorithm that's +similar to the Viterbi, + +but instead of taking +the maximum entering + +each hidden state at +intermediate positions, + +you sum those inputs. + +So you just do the +sum at every point. + +And it turns out that will +calculate the sum of the two + +values at the end-- or +the k values at the end + +will be equal to the sum of +the probabilities of generating + +the observable sequence +over all possible sequences + +of hidden states. + +OK, so that's useful. + +And then you can also +run it backwards. + +There's no reason it has to be +only going in one direction. + +And so what you do is you run +these sort of summing versions + +of the Viterbi in both +the forward direction + +and also run one in +the backward direction. + +And then you take a +particular position here-- + +like let's say this is your +helix state, for example. + +And we're interested +in this position + +somewhere in the +middle of the protein. + +Is that a helix or not? + +And so basically +you take the value + +that you get here +from the forward + +in your forward +algorithm and the value + +that you get here in +the backward algorithm, + +and multiply those two +together, and divide by this Po. + +And that gives you +the probability. + +So that ends up being +a way of calculating + +the sum of all +the parses that go + +through this particular +position i in the sequence + +in that particular state. + +I mean, I realize that may +not have been totally clear, + +and I don't want to take more +time to totally go into it, + +but it is pretty well +described and Rabener. + +And I'll just give +you an example. + +So if you're motivated, +please take a look at that. + +And if you have +further questions, + +I'd be happy to discuss +during office hours next week. + +And this is what it looks like +for this particular protein. + +So you get something called the +posterior probability, which + +is the sum of the probabilities +of all the parses. + +And they've plotted it for +the particular state that + +is in the Viterbi path, that +is in the optimal parse-- + +so for example, in blue here. + +Well, actually, they've done +it for all the different states + +here. + +So blue is the probability +that you're outside. + +OK, so it's very, very +confident that the end terminus + +of the protein is +outside the cell. + +It's very, very confident +in the locations + +of transmembrane +helices one and two. + +It actually more +often than not thinks + +there's actually a +third helix right here, + +but that didn't make it +in the optional parse. + +That actually occurs in +the majority of parses, + +but not in the optimal. + +And it's probably because it +would then cause other things + +to be flipped later on if you +had transmembrane helix there. + +It's not sure whether +there's a helix there or not, + +but then it's +confident in this one. + +OK, so this gives you an idea. + +Now if you wanted to do some +sort of test of the prediction, + +you want to test probably +first the higher confidence + +predictions, so you might +do something right here. + +Or if maybe from +experience you know + +that when it has a +probability that's that high, + +it's always right, so +there's no point testing it. + +So you should test one of these +kind of less confident regions. + +So this actually makes the +prediction much more useful + +to have some degree +of confidence assigned + +to each part of the prediction. + +So for the remainder +of today, I want + +to turn to the topic of +RNA secondary structure. + +So at the beginning, +I will sort of + +get through some nomenclature. + +And then to motivate the topic, +give some biological examples + +of RNA structure. + +Gives me an excuse to show some +pretty pictures of structure. + +And then we'll talk about +two approaches which + +are two of the most widely used +approaches toward predicting + +structure. + +So using evolution +to predict structure + +by method of co-variations, +which works well when you + +have many homologous sequences. + +And then using sort +of first principles + +thermodynamics to predict +secondary structure + +by energy minimization +where obviously you + +don't need to have a +homologous sequence present. + +And the nature +biotechnology primer + +on RNA folding +that I recommended + +is a good intro to the +energy minimization approach. + +So what is RNA +secondary structure? + +So you all know that +RNAs, like proteins, + +have a three-dimensional +tertiary fold structure that, + +in many cases, determines +their function. + +But there's also sort of +a simpler representation + +of this structure where you just +describe which pairs of bases + +are hydrogen bonded +to one other. + +OK, and so for RNA-- so +it's a famous example + +of an RNA structure, this +sort of clover leaf structure + +that all tRNAs have. + +The secondary structure of the +tRNA is the set of base pairs. + +So it's this base pair +here between the first base + +and this one toward +the end, and then + +base right here, and so forth. + +And so if you specify +all those base pairs, + +then you can then draw a picture +like this, which gives you + +a good idea of what parts of +the RNA molecule are accessible. + +So for example, +it won't tell you + +where the anticodon +loop is, which + +is sort of the business +end of the tRNA. + +But it narrows it down +to three possibilities. + +You might consider that, +or that, or down here. + +It's unlikely to be +something in here + +because these bases +are already paired. + +They can't pair to message. + +So it gives you sort of a first +approximation toward the 3D + +structure, and so +it's quite useful. + +So how do we represent +secondary structure? + +So there's a few different +common representations + +that you'll see. + +So one is-- and this is sort +of a computer-friendly but not + +terribly human-friendly +representation, + +I would say-- is +this sort of dot + +in parentheses notation here. + +So the dot is an unpaired +base and the parenthesis + +is a paired base. + +And how do you know-- chalk +is sort of non-uniformly + +distributed here-- so if you +have a structure like this + +and you have these +three parentheses, what + +are they paired to? + +Well, you don't know yet +until you get further down. + +And then each left +parenthesis has + +to have a right +parenthesis somewhere. + +So now if we see +this, then we know + +that there are two +unpaired bases here, + +and then there's +going to be three + +in a row that are +paired-- these guys. + +We don't know what +they're paired to yet. + +Then there's going to be a +five base pair loop, maybe + +a little pentagon type thing. + +Two, three, four-- +oops-- four, five. + +And this one would be +the right parentheses + +that pair with the left +parentheses over here. + +I should probably +draw this coming out + +to make it clearer +that it's not paired. + +So this notation you +can convert to this. + +So after a while, it's +relatively easy to do this, + +except when they're super long. + +So that's what the left part +of that would look like. + +So what about the right part? + +So the right part, we have +something like one, two, three, + +four, bunch of dots, and then +we have two, and then a dot, + +and then two. + +What does that thing look like? + +So that's going to look like +four bases here in a stem. + +Big loop, and then there's +going to be two bases that + +are paired, and then +a bulge, and then + +two more that are paired. + +These things happen +in real structures. + +OK and then the +arced notation is + +a little more human-friendly. + +It actually draws an +arc between each pair + +of bases that are +hydrogen bonded. + +So I'm sure you can imagine +what those structures would + +look like. + +And it turns out that the +arcs are very important. + +Like whether those +arcs cross each other + +or not is sort of a fundamental +classification of RNA + +secondary structures, into +the ones that are tractable + +and the ones that +are really difficult. + +So pretty pictures of RNA. + +So this is a lower +resolution cryo-EM structure + +of the bacterial ribosomes. + +Remember, ribosomes have two +sub-units-- a large sub-unit, + +50S, and a small sub-unit, 30S. + +And if you crack it open-- +OK, so you basically split. + +You sort of break the ribosome +like that, and you look inside, + +they're full of tRNAs. + +So there are three +pockets that are normally + +distinguished within ribosomes. + +The A site-- this +is the site where + +the tRNA enters +that's going to add + +a new amino acid to the +growing peptide chain. + +The P site, which is +this tRNA will have it + +[INAUDIBLE] with the +actual growing peptide. + +And then the exit tunnel where +this tRNA will eventually-- + +the exit, the E site, +which is the one that + +was added a couple +of residues ago. + +So people often think +of RNA structure + +just in terms of these +secondary structures + +because they're much +easier to generate + +than tertiary structures, and +they give you-- like for tRNA, + +it gives you some pretty good +information about how it works. + +But for a large and complex +structure like the ribosome, + +it turns out that +RNA is actually not + +bad at building +complex structures. + +I would say it's not +as good as protein, + +but it is capable of +constructing something + +like a long tube. + +And in fact, in +the ribosome, you + +find such a long +tube right here. + +That is where the peptide +that's been synthesized + +exits the ribosome. + +And you'll notice it's not +a large cavity in which + +the protein might start folding. + +It's a skinny tube that is thin +enough that the polypeptide has + +to remain linear, cannot +start folding back on itself. + +So you sort of +extrude the protein + +in a linear, unfolded +confirmation, + +and let it fold outside +of the ribosome. + +If it could fold inside +that, that might clog it up. + +That's probably one reason why +it's not designed that way. + +I'm sure that was tried +bye evolution and rejected. + +So if you look at the +ribosome-- now remember, + +the ribosome is composed +of both RNA and protein-- + +you'll see that it's much +more of one than the other. + +And so it's really much more +of the fettuccine, which + +is the RNA part, than the +linguini of the protein. + +And if you also look +at the distribution + +of the proteins on +the ribosome, you'll + +see that they're +not in the core. + +They're kind of decorated +around the edges. + +It really looks like something +that was originally made out + +of RNA, and then you sort of +added proteins as accessories + +later. + +And that's probably +what happened. + +This is based on +the structures that + +were solved a few years ago. + +If you then look at where +the nearest proteins are + +to the active site-- actual +catalytic site-- remember, + +the ribosome catalyzes peptide +in addition to an amino acid + +to a growing peptide, so +peptide bond formation-- + +you'll find that the +nearest proteins are around + +18 to 20 angstroms away. + +And this is too far +to do any chemistry, + +so the active site +residues or molecules + +need to be within +a few angstroms + +to do any useful chemistry. + +And so this basically +proves that the ribosome. + +Is a ribozyme. + +That is, it's an RNA enzyme. + +RNAs is [INAUDIBLE]. + +So here is the +structure of a ribosome. + +It's very kind of beautiful, +and it's impressive + +that somebody can actually +solve the structure of something + +this big. + +But what is actually +the practical use + +of this structure? + +Turns out there's quite an +important practical application + +of knowing the structure. + +Any ideas? + +AUDIENCE: Antibiotics. + +PROFESSOR: Antibiotics. + +Exactly. + +So many antibiotics work by +taking advantage of differences + +between the prokaryotic +ribosome structure + +and eukaryotic +ribosome structure. + +So if you can make +a small molecule-- + +these are some examples-- +that will inhibit + +prokaryotic ribosomes +but hopefully not + +inhibit eukaryotic +ribosome, then + +you can kill bacteria that +might be infecting you. + +So non-coding RNA. + +So there's many different +families of non-coding RNAs, + +and I'm going to list +some in a moment. + +And I'm going to +actually challenge + +you, see if you can +come up with any more + +families of non-coding RNAs. + +But they're receiving +increasing interest, + +I would say, ever since +micro RNA's were discovered. + +Sort of a boom in looking +at different types + +of non-coding RNAs. + +Link RNA is also important and +interesting, as well as many + +of the classical RNA's like +tRNAs and rRNAs and snoRNAs. + +There may be new aspects of +their regulation and function + +that will be interesting. + +And so when you're +studying a non RNA, + +it's very, very helpful +to know its structure. + +If it's going to base pair in +trans with some other RNA-- + +as tRNAs do, as micro RNA's +do, for example, or snRNAs + +and snoRNAs-- then +you want to know + +which parts of the +molecule are free + +and which are +internally based paired. + +And if you want to predict +non RNAs genes in a genome, + +you may want to look +for regions that + +are under selection for +conservation of RNA structure, + +for conservation +of the potential + +to base pair at some distance. + +If you see that, +it's much more likely + +that that region of the genome +encodes a non-coding RNA + +than it codes, for example-- +there's a coding axon + +or that it's a +transcription factor binding + +site or something like that +that functions at the DNA level. + +So having this +notion of structure-- + +even just secondary structure-- +is helpful for that application + +as well, and predicting +functions as well, + +as I mentioned. + +So co-variation. + +So let's take a look +at these sequences. + +So imagine you've discovered a +new class of mini micro RNA's. + +They're only eight bases +long, and you've sequence five + +homologues from your +five favorite mammals. + +And these are the +sequences that you get. + +And you know that +they're homologous + +by [? a centimeter ?], +they're in the same place + +in the genome, and they seem +to have the same function. + +What could you say about +their secondary structure + +based on this +multiple alignment? + +You have to stare at it a +little bit to see the pattern. + +There's a pattern here. + +Any ideas? + +Anyone have a guess about +what the structure is? + +Yeah, go ahead. + +AUDIENCE: There's a two +base pair stem, and then + +a four base loop. + +PROFESSOR: Two base pair +stem, four base loop, + +and you have of the stem. + +So how do you know that? + +AUDIENCE: So if you +look at the first two + +and last two bases +of each sequence, + +the first and the +eighths nucleotide + +can pair with each other, and so +can the second and the seventh. + +PROFESSOR: Yeah. + +Everyone see that? + +So in the first +column you have AUACG, + +and that's +complementary to UAUGC. + +Each base is complementary. + +And the second position is +CAGGU complementary to GUCUA. + +There's one slight +exception there. + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Yeah. + +Well, it turns out that that +RNA-- although the Watson Crick + +pairs GC and AU are the +most stable-- GU pairs + +are only a little bit +less stable than AU pairs, + +and they occur in +natural RNA molecules. + +So GU is allowed in RNA +even though you would never + +see that in DNA. + +OK, so everyone see that? + +So the structure is-- +I think I have it here. + +This would be co-variation +You're changing the bases, + +but preserving the +ability to pair. + +So when one base change-- when +the first base changes from A + +to U, the last base +changes from U to A + +in order to preserve +that pairing. + +You wouldn't know that if +you just had two sequences, + +but once you get +several sequences, + +it can be pretty +compelling and allow + +you to make a pretty +strong inference that that + +is the structure +of that molecule. + +So how would you do this? + +So imagine you had a more +realistic example where + +you've got a non-coding RNA +that's 100 or a few hundred + +bases long, and you might have +a multiple alignment of 50 + +homologous sequences. + +You want something, +you're not going + +to be able to see it by eye. + +You need sort of a more +objective criterion. + +So one method +that's commonly used + +is this statistic IX +mutual information. + +So if you look in your +multiple alignment-- + +I'll just draw this here. + +You have many sequences. + +You consider every +pair of columns-- + +this is a multiple alignment, +so this column and this column-- + +and you calculate +what we're going + +to call-- what are we +going to call it? f ix. + +That would be the frequency +of a nucleotide x. + +You're in column i, so you just +count how many A's, C's, G's, + +and T's there are. + +And similarly, f jy for +all the possible values + +of x and all the +possible values of y. + +So these are the base +frequencies in each column. + +And then you calculate the +dinucleotide frequencies xy + +at each pair of columns. + +So in this colony, you say if +there's an A here and a C here, + +and then there's +another AC down here, + +and there's a total of one, +two, three, four, five, six, + +seven sequences, +then f AC ij is 2/7. + +So you just calculate the +frequency of each dinucleotide. + +These are no longer consecutive +dinucleotides in a sequence + +necessarily there. + +They can be in +arbitrary spacing. + +OK, so you calculate +those and then + +you throw them +into this formula, + +and out comes a number. + +So what does this +formula remind of? + +Have you seen a +similar formula before? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Someone said +[INAUDIBLE] Yeah, go ahead. + +AUDIENCE: It reminds me of the +Shannon entropy [INAUDIBLE]. + +PROFESSOR: Yeah, it looks +like Shannon entropy, + +but there's a log +of a ratio in there, + +so it's not exactly +Shannon entropy. + +So what other formula has +a log of a ratio in it? + +AUDIENCE: [INAUDIBLE] + +PROFESSOR: Relative. + +So it actually looks +like relative entropy. + +So relative entropy +of what versus what? + +Who can sort of say more +precisely if it's-- we'll say + +it's relative entropy of +something versus a p versus q. + +And what is p and what is q? + +Yeah, in the back. + +AUDIENCE: Is it relative +entropy of co-occurrence + +versus independent occurrence? + +PROFESSOR: Good. + +Yeah. co-occurence-- +everyone get that? + +Co-occurrence of a pair of +nucleotide xy at positions ij. + +Versus q is an +independent occurrence. + +So if x and y occurred +independently, + +they would have this frequency. + +So if you think about it, +you calculate the frequency + +of each base at each column +in the multiple alignment. + +And this is like +your null hypothesis. + +You're going to assume, what if +they're evolving independently? + +So if it's not a folded +RNA-- or if it's a folded RNA + +but those two columns +don't happen to interact-- + +there's no reason to suspect +that those bases would + +have any relationship +to each other. + +So this is like +your expected value + +of the frequency of +xy in position ij. + +And then this p is +your observed value. + +So you're taking relative +entropy of basically observed + +over expected. + +And so relative entropy +has-- I haven't proved this, + +but it's non-negative. + +It can be 0, and then it +goes up to some maximum, + +a positive value, but +it's never negative. + +And what would it be if, +in fact, p were equal to q? + +What would this formula give? + +This is where we're +saying suppose. + +Suppose this. + +In general, this won't +be sure, but suppose + +it was equal to that. + +We've got mi ij equals +summation of what? + +That log of this, +which is equal to this, + +so it's fx i fy j +over the same thing-- + +hope you can see that-- log +of-- log of 1 is 0, right? + +So it's just 0. + +So if the nucleotides +of the two columns + +occur completely independently, +mutual information is 0. + +And that's one reason it's +called mutual information. + +There's no information. + +Knowing what's in +column i gives you + +no information about column j. + +So remember, relative entities +are measures of information, + +not entropy. + +And what is the maximum value +that the mutual information + +could have? + +Any ideas on that? + +Any guesses? + +Joe, yeah. + +AUDIENCE: You could have +log base 2 log over f sub x, + +f sub y. + +PROFESSOR: Of 1? + +OK, so you're saying if one of +the particular dinucleotides + +had a frequency of 1? + +AUDIENCE: Yeah. + +So if they're always the same +whenever there's-- like an A, + +there's always going to be a T. + +PROFESSOR: Right. + +So whenever there's an A, +there's always a G or a T. + +AUDIENCE: So then you'd +get a 1 in the numerator, + +and they're relative +probably in the bottom, which + +would be maximized if +they were all even. + +PROFESSOR: If they were all? + +[INTERPOSING VOICES] + +PROFESSOR: If they were uniform. + +Yeah. + +So did everyone get that? + +So the maximum occurs if fx i +and j-- they're both uniform, + +so they're a quarter for +every base at both positions. + +That's the maximum entropy in +the background distribution. + +But then if fx y ij equals +1/4, for example, x equals y-- + +or in our case, we're +not interested in that. + +We're interested in x +equals complement of y. + +C of y is going to be +the complement of y. + +And 0 otherwise for x not +equal complement of y. + +OK, so for example, if we have +only the dinucleotides AT, + +CG, GC, and TA occur, +and each of them + +occurs with a +frequency of 1/4, then + +you'll have four terms in +the sum because, remember, + +the 0 log 0 is 0. + +So you'll have four terms +in the sum, and each of them + +will look like 1/4 log +1/4 over a 1/4 times 1/4. + +And so this will be 4, +so log 2 of 4 4 is 2. + +And so you have four terms +that are each 1/4 times 2. + +And so you'll get 2. + +Well, this is not a sum. + +These are the four terms. + +These are the individual +nonzero terms in that sum. + +Does that make sense? + +Everyone get this? + +So that's why this is a useful +measure of co-variation. + +If what's in one +column really strongly + +influences what's +in the other column, + +and there's a lot of +variation in the two columns, + +and so you can really see +that co-variation well, + +then mutual information +is maximized. + +And that's basically +what we just said, + +is written down here. + +So it's maximal. + +They don't have to +be complementary. + +It would achieve this maximum +of 2 if they are complementary, + +but it would be also if they +had some other very specific + +relationship between +the nucleotides. + +So if you're going to use +this, the way you would use it + +is take your multiple +alignment, calculate + +the mutual information +of each pair of columns-- + +so you actually have to +make a table, i versus j, + +all possible pairs +of columns-- and then + +you're going to look for +the really high values. + +And then when you find +those high values, when + +you look at what actual bases +are tending to occur together, + +you'll want to see +that they're bases + +that are complementary +to one another. + +And another thing +that you'd want to see + +is you'd want to see that +consecutive positions in one + +part of the alignment +are co-varying + +with consecutive positions in +another part of the alignment + +in the right way, in this sort +of inverse complementary way + +that RNA likes to pair. + +Does that make sense? + +So in a sort of nested way +in your multiple alignment, + +if you saw that this +one co-varied with that, + +and then you also saw that +the next base co-varied + +with the base right +before this one, + +and this one co-varies +with that one, + +that starts to look like a stem. + +It's much more likely that +you have a three-base stem + +than that you just +have some isolated base + +pair out in the +middle of nowhere. + +It turns out it takes +a few bases to make + +a good thermodynamically +stable stem, + +and so you want to look +for blocks of these things. + +And so this works pretty well. + +Yeah, actually, one point +I want to make first + +is that mutual +information is nice + +because it's kind +of a useful concept + +and it also relates to some +of the entropy and relative + +entropy that we've been talking +about in the course before. + +But it's not the only statistic +that would work in practice. + +You can use any measure of +basically non-independence + +between distributions. + +A chi square statistic +would probably + +work equally well in practice. + +And so here is a +multiple alignment + +of a bunch of sequences. + +And what I've done is +put boxes around columns + +that have significant + +mutual information with +other sets of columns. + +So for example, this set of +columns here at the left-- the + +far left-- has significant +mutual information + +with the ones at the far right. + +And these ones, +these four positions + +co-vary with these +four, and so forth. + +So can you tell, +based on looking + +at this pattern of +co-variation, what + +the structure is going to be? + +OK, let's say we start up here. + +The first is going to +pair with the last, + +with something at the end. + +Then we're going +to have something + +here in the middle that pairs +with something else nearby. + +Then we have something +here that pairs + +with something else nearby, +then we have another like that. + +Does that make sense? + +So that there's these +three pairs of columns + +in the middle-- these two, these +two, and these two-- and then + +they're surrounded +by this thing, + +the first pairing with the last. + +And so it's a clover +leaf, so that's tRNA. + +Yeah? + +AUDIENCE: So with that previous +slide, this table here, + +you could create a +co-variation matrix. + +How would that-- or, +and it could be-- + +PROFESSOR: How does that +co-variations matrix-- + +how do you convert it +to this representations? + +AUDIENCE: I'm just wondering +how this would go up. + +Like let's say you took +the co-variation matrix-- + +PROFESSOR: Oh, what +would it look like? + +AUDIENCE: --and visualized +it as a heat map-- + +PROFESSOR: In the +co-variation matrix. + +AUDIENCE: Yeah. + +What would it look like in +this particular example? + +PROFESSOR: Yeah, +that's a good question. + +OK, let's do that. + +I haven't thought +about that before, + +so you'll have to +help me on this. + +So here's the beginning. + +We're going to write +the sequence from 1 + +to n in both dimensions. + +And so here's the beginning, +and it co-varies with the end. + +So this first would have a +co-variation with the last, + +and then the second would +co-vary with the second + +to last, and so forth. + +So you get a little +diagonal down here. + +That's this top stem here. + +And then what about +the second stem? + +So then you have +something down here + +that's going to co-vary with +something kind of near by it. + +So block two is going to +co-vary with block three. + +And again, it's going to be +this inverse complementary kind + +of thing like that. + +It's symmetrical, so +you get this with that. + +But you only have +to do one half, + +so you can just do +this upper half here. + +So you get that. + +So it would look +something like that. + +AUDIENCE: So with the +diagonal line orthogonal + +to the diagonal of the matrix-- + +PROFESSOR: Yeah, that's because +they're inverse complementary. + +AUDIENCE: OK. + +PROFESSOR: That make sense? + +Good question. + +But we'll see an +example like that later + +actually, as it turns out. + +All right, so here's +my question for you. + +You're setting this +non-coding RNA. + +It has some length. + +You have some +number of sequences. + +They might have some structure. + +Is this method going to +work for you, or is it not? + +What is required for it to work? + +For example, would +I want to isolate + +this gene-- this +non-coding RNA gene-- + +just from primates, from +like human, gorilla, + +chimp, orangutan, and +do that alignment? + +Or would I want to go further? + +Would I want to go back to +the rodents and dog, horse-- + +how far do you want to go? + +Yeah, question. + +AUDIENCE: I think we a need a +very strong sequence alignment + +for this, so we +cannot go very far, + +because if you don't have +a high percentage homology, + +then you will see all +sorts of false positives. + +PROFESSOR: Absolutely. + +So if you go too far, your +alignment will suffer, + +and you need an +alignment in order + +to identify the +corresponding columns. + +So that puts an upper limit +on how far you can go. + +But excellent point. + +Is there a lower limit? + +Do you want to go as +close as possible, + +like this example I gave +with human, chimp, orangutan? + +Or is that too close? + +Why is too close bad? + +Tim? + +AUDIENCE: Maybe if +you're too close, + +then the sequence is +having to [INAUDIBLE] + +to give you enough +information [INAUDIBLE]. + +PROFESSOR: Yeah, exactly. + +They're all the same. + +Actually, you'll +get 1 times 1 over 1 + +in that mutual information +statistic, which log of that + +is going to be 0. + +There's zero mutual information +if they're all the same. + +So there has to +be some variation, + +and the structure +has to be conserved. + +That's key. + +You have to assume that the +structure is well conserved + +and you have to have +a good alignment + +and there has to +be some variation, + +a certain amount of variation. + +Those are basically +the three keys. + +Secondary structure has a more +highly conserved sequence. + +Sufficient divergence so that +you have these variations, + +and sufficient number of +homologues you have to get good + +statistics, and not so far +they your alignment is bad. + +Sorry about that. + +Sally? + +AUDIENCE: It seems +like another thing + +that we assume here is that +you can project it onto a plane + +and it will lie flat. + +So if you have some very +important, weird folding + +that allows you to, say, +crisscross the rainbow thing. + +PROFESSOR: Yeah, +crisscross the rainbow. + +Yeah, very good question. + +So in the example +of tRNA, if you + +were to do that arc +diagram for tRNA, + +it would look like +another big arc-- + +that's the first and +last-- and then you + +have these three nested arcs. + +Nothing crisscrossing. + +What if I saw-- [INAUDIBLE]-- +two blocks of sequence that + +have a relationship like that? + +Is that OK? + +With this method, the +co-variation, that's OK. + +There's no problem there. + +What does this +structure look like? + +So [INAUDIBLE] you have a +stem, then you have a loop, + +and then a stem. + +So this is 1 pairs with 3. + +That's 1. + +That's 3. + +Then you've got 2 up +here, but 2 pairs with 4. + +So here's 4 over +here, so 4 is going + +to have to come back up +here and pair with 2. + +This is 2 over here. + +So that is called a pseudoknot. + +It's not really a knot +because this thing doesn't + +go through the +loop, but it kind of + +behaves like a +knot in some ways. + +And so do these actually +occur in natural RNAs? + +Yes, Tim is nodding. + +And are they important? + +Can you give me an example +where they are important + +biologically? + +AUDIENCE: [INAUDIBLE] + +[INTERPOSING VOICES] + +PROFESSOR: Riboswitches. + +We're going to come +to what riboswitches + +are in a moment for +those not familiar. + +And I think I have +an example later + +of a pseudoknot +that's important. + +So that's a good question. + +I think I should have added +to this list the point + +that you made in +the back that they + +have to be close enough that +you can get a good alignment. + +I should add that to this last. + +Thanks. + +It's a good point. + +All right, so classes +of non-coding RNAs. + +As promised, my +favorites listed here. + +Everyone knows tRNAs, rRNAs. + +You can think of UTRs +as being non RNAs. + +They often have +structure that can + +be involved in +regulating the message. + +snRNAs involved splicing. + +snoRNAs-- small +nucleolar RNAs-- are + +involved in directing +modification + +of other RNAs, such as ribosomal +RNAs and snRNAs, for example. + +Terminators of +transcription in prokaryotes + +are like little stem +loop structures. + +RNaseP is an important enzyme. + +SRP is involved in targeting +proteins with signal peptides + +to the export machinery. + +We won't go into tmRNA. + +micro RNAs and link +RNAs, you probably + +know, and riboswitches. + +So Tim, can you tell us +what a riboswitch is? + +AUDIENCE: A riboswitch +is any RNA structure + +that changes +confirmation according + +to some stimulus [INAUDIBLE] +or something in the cell. + +It could be an ion, critical +changes in the structure. + +[INAUDIBLE] + +PROFESSOR: Yeah, that was great. + +So just for those that +may not have heard, + +I'll just say it again. + +So a riboswitch is +any RNA that can + +have multiple confirmations, +and changes confirmation + +in response to some stimulus-- +temperature, binding + +of some ligand, small molecules, +something like that, et cetera. + +And often, one of +those structures + +will block a particular +regulatory element. + +I'll show an +example in a moment. + +And so when it's in +one confirmation, + +the gene will be repressed. + +And when it's in +the other, it'll + +be on. so it's a way of using +RNA's secondary structure + +to sense what's +going on in the cell + +and to appropriately +regulate gene expression. + +All right, so now we're going +to talk about a second approach. + +So this would be the approach. + +You've got some RNA. + +It may not do something, +and maybe you can't find any + +homologues. + +It might be some newly +evolved species-specific RNA, + +or your studying +some obscure species + +where you don't have a lot +of genomic sequence around. + +So you want to use the +first principles, approach, + +the energy +minimization approach. + +Or maybe you have +the homologues, + +but you don't trust +your alignment. + +You want a second +opinion on what + +the structure is going to be. + +So just in the way +that protein folding-- + +you could think of +an equilibrium model + +where it's determined +by folding free energy, + +and enthalpy will +favor base pairing. + +You get gain some enthalpy +when you form a hydrogen bond, + +and entropy will tend +to favor unfolding. + +So an RNA molecule +that's linear has + +all this confirmational +flexibility, + +and lose some of that +when you form a stem. + +It forms a helix. + +Those things don't have +as much flexibility. + +And even the nucleotides in +the loop are a little bit + +confirmationally-- +they're not as flexible + +as they were when it was linear. + +So that means that +at high temperatures, + +it'll favor unfolding. + +So the earliest +approaches were approaches + +that sought to maximize +the number of base pairs. + +So they basically ignore entropy +and focus on the enthalpy + +that you gain from +forming base pairs. + +And so Ruth Nussinov +described the first algorithm + +to figure out what is the +maximum number of base pairs + +that you can form in an RNA. + +And so a way to +think about this is + +imagine you've +got this sequence. + +What is the largest +number of base pairs + +I can form with this sequence? + +I could just draw all +possible base pairs. + +That A can pair with that T. +This A can pair with that T. + +They can't both pair +simultaneously, right? + +And this C can pair with that G. +So if we don't allow crossing, + +which-- coming back +to Sally's point-- + +this would cross this, right? + +So we're not going +to allow that. + +So the best you could do be to +have this A pair with this C + +and this C pair with this G +and form this little structure. + +This is not realistic because +RNA loops can't be one base. + +They minimum is about three. + +But just for the +sake of argument, + +you can list all these +out, but imagine now + +you've got 100 bases here. + +Every base will on +average potentially + +be able to pair with +24 or 25 other bases. + +So you're just going to have +just an incredible mishmash + +of possible lines +all crisscrossing. + +So how do you figure out how +to maximize that pairing? + +Any ideas? + +Don, yeah? + +AUDIENCE: You look for +sections of homology. + +PROFESSOR: We're +not using homology. + +We're doing [INAUDIBLE] + +AUDIENCE: I'm sorry, not +homology, but sections where-- + +PROFESSOR: Complementary? + +AUDIENCE: Complementary. + +Yeah, that's the +word I was thinking. + +PROFESSOR: The blocks +are complementary. + +AUDIENCE: And then so-- + +PROFESSOR: You could blast +the sequence against inverse + +complements itself and +look for little blocks. + +You could do that. + +That's not what +people generally do, + +mostly because the blocks of +complementarity in real RNA + +structures are really short. + +They can be two, +three, four, bases. + +Sally, yeah? + +AUDIENCE: Could you use +[INAUDIBLE] approach + +where you just start with a +very small case and build up? + +PROFESSOR: So we've seen that +work for protein sequence + +alignment. + +We've seen it work for +the Viterbi algorithm. + +So that is sort of the go-to +approach in bioinfomatics, + +is to use some sort of +dynamic programming. + +Now this one for RNA +secondary structure + +that Nussinov came up +with is a little bit + +different than the others. + +So you'll see it has a +kind of different flavor. + +It turns out to be +actually it's a little hard + +to get your head around +at the beginning, + +but it's actually +easier to do by hand. + +So let's take a look at that. + +OK, so recursive +maximization of base pairing. + +Now the thing about +base pairing that's + +different from +these other problems + +is that the first +base in the sequence + +can base pair with the last. + +How do you chop up a sequence? + +Remember with Needleman-Wunsch +and with Viterbi + +we go from the +beginning to the end, + +and that's a logical order. + +But with base pairing, that's +actually not a logical order. + +You can't really do it that way. + +So instead, you go +from the inside out. + +You start in the +middle of a sequence + +and work your way outwards +in both directions. + +Or another way to think about +it is you start with you write + +the sequence from 1 +to n on both axes, + +and then actually we'll see that +we initiate the diagonal all + +to 0's. + +And then we think about +these positions here next. + +So 1 versus 2. + +Could 1 pair with 2? + +And could 2 pair with 3? + +Those are like little +bits of possible RNA + +secondary structure. + +Again, we're ignoring +this fact that loops + +have to be certain minimum. + +This is sort of a +simplified case. + +And then you build outwards. + +So you conclude that base 4 +here could pair with base 5, + +so we're going to put a 1 there. + +And then we're going +to build outward + +from that toward the +beginning of the sequence + +and toward the end, adding +additional base pairs + +when we can. + +That's basically the way +the [INAUDIBLE] works. + +And so that's one +key idea, that we + +go from sort of +close sequences, work + +outward, to faraway sequences. + +And the second key idea +is that the relationship + +that, as you add more bases +on the outside of what you've + +already got, that the optimal +structure in that larger + +portion of sequence +space is related + +to the optimal structures +of smaller portions of it + +in one of four different ways. + +And these are the four ways. + +So let's look at these. + +So the first one is +probably the simplest + +where if you're doing this, +you're here somewhere, + +meaning you've compared +sequences from position, + +let's say, i minus +1 to j minus 1 here. + +And then we're going to +consider adding-- actually, + +it depends how you +number your sequence. + +Let me see how this is done. + +Sorry. i plus 1. + +i plus 1 to j minus 1. + +We figured out what the +optimal structure is in here, + +let's suppose. + +And now we're going to +consider adding one more + +base on either end. + +We're going to add j +down here, and we're + +going to ask if it pairs with i. + +And if so, we're going to take +whatever the optimal structure + +was in here and we're +going to add one base pair, + +and we're going to +add plus 1 because now + +it's got one additional. + +We're counting base pairs. + +So that's that first case there. + +And then the second case is +you could also consider just + +adding one unpaired base onto +whatever structure you had, + +and then you don't add one. + +And you could go in +either direction. + +You can go sort of toward of +the beginning of the sequence + +or toward the end +of the sequence. + +And then the third +one is the tricky one, + +is what's called a bifurcation. + +You could consider +that actually i and j + +are both paired, but +not with each other. + +That i pairs with something +that was inside here + +and j pairs with something +that was inside here. + +So your optimal parse +from i to j, if you will, + +is not going to come from the +optimal parse from i plus 1 + +to j minus 1. + +It's going to come from +rethinking this and doing + +the optimal parse from here +to here and from here to here, + +and combining those two. + +So you're probably +confused by now, + +so let me try to do an example. + +And then I have an analogy +that will confuse you further. + +So ask me for that one. + +This was the simplest +one I could come up + +with that has this property. + +OK, so we said before that +if you were doing the optimal + +from 1 to 5, that it would be +the AC pairing with the GT. + +We do that one. + +And now if you notice, this guy +is kind of a similar sequence. + +I just added a T at the +beginning and an A at the end. + +And so you can probably imagine +that the best structure of this + +is here, those three. + +You've got three pairs of +this sub-sequence here. + +That's as good as you +can do with seven bases. + +You can only get three pairs. + +And this is as good as +you can do with five, + +so these are clearly optimal. + +So the issue comes that if +you're starting from somewhere + +in the middle here-- let's +say you are-- let's see, + +so how would you be doing this? + +You start here. + +Let's suppose the first two +you consider are these two. + +You consider pairing +that T with that A. + +You can see this is +not going to go well. + +You might end up with that +as your optimal substructure + +of this region. + +Remember, you're working +from the inside out, + +so you're going from here to +here, and you end up with that. + +And what do you do here? + +You don't have a G +to pair the C to, + +so you add another +unpaired base. + +Now you've got this +optimal substructure + +of a sequence that's +almost the whole sequence. + +It's just missing the +first and last bases, + +but it only has +three base pairs. + +So when you go to add +this, you can say, + +oh, I can't add any more base +pairs, so I've only got three. + +But you should consider +that we've already + +solved the optimal +structure of that, + +and we had two nice pairs here. + +We had that pair and +that pair, and we already + +solved the substructure +of the optimal structure + +of this portion here, and +you had those three pairs. + +And so you can combine those +two and all of a sudden + +you can do much better. + +So that's what that +bifurcation thing is about. + +So this is the +recursion working out, + +and you can see that's +the base pairing one. + +You can add one, or you can +just add an unpaired base + +and you don't add anything. + +Or you consider all +the possible locations + +of bifurcations in-between the +two positions you're adding, + +i and j, and you consider +all the possible pairs. + +And you just sum up each +pair and go-- I'm sorry, + +you don't sum them up. + +You consider them all, and +then you take the maximum. + +All right, so the algorithm +is to take an n by n matrix, + +initialize the diagonal to 0, +and initialize the sub-diagonal + +to 0 also. + +Just don't think +too much about that. + +Just do it. + +And then fill in this +matrix recursively + +from the diagonal +up and to the right. + +And it actually doesn't matter +what order you fill it in + +as long as you're kind +of working your way up + +into the right. + +You have to have the thing +to the left and the thing + +below already filled in if +you're going to fill in a box. + +And then you keep track of +the optimal score, which + +is going to be the +sum of base pairs. + +And then you also keep +track of how you got there. + +What base pair did you add +so that you can trace back? + +And then when you get +up to the upper right + +corner of this matrix, +you then trace back. + +So here is a partially +filled in this matrix. + +This is from that the +Nature Biotechnology Review. + +And the 0's are filled in. + +So here's what I want +you to do at home, + +is print out, photocopy or +whatever-- make this matrix, + +or make a bigger +version of it perhaps-- + +and look at the sequence +and fill in this matrix, + +and fill in the little arrows +every time you add a base pair. + +It's actually not that hard. + +There are no bifurcations in +this, so that's the tricky one. + +Ignore that one. + +You'll just be +adding base pairs. + +It'll be pretty easy. + +And then you can +reconstruct the sequence. + +So here it is filled in. + +And the answer is given, +so you can check yourself. + +But do it without +looking at the answer. + +And then you go to the +upper right corner. + +That means that the +optimal structure + +from the beginning of the +sequence to the end-- which, + +of course, was our +goal all along. + +And then you trace +back and you can + +see whenever you're +moving diagonally here, + +you're adding a base pair. + +Remember, you add +one on each end, + +and so you're moving diagonally +and adding the base pair, + +and you get this +little structure here. + +So computational complexity +of the algorithm. + +You could think about this +but I'll just tell you. + +It's memory n squared +because you've + +got to fill in this +matrix, so square + +of the length of the sequence. + +Time n cubed. + +This is bad now. + +And why is it n cubed? + +It's n cubed because you have to +fill in a matrix that's n by n. + +And then when you do +that maximization step, + +that check for bifurcations, +that's sort of of order n, + +as well. + +So n cubed-- so this means +that RNA folding is slow. + +And in fact, some +of the servers won't + +allow you to fold anything +more than a thousand + +bases because they'll take +forever or something like that. + +And it cannot +handle pseudoknots. + +If you think through +the recursion, + +pseudoknots will be a problem. + +I'm going to just +show you-- yeah, + +I'll get to this-- that +these are from the viruses. + +Real viruses, some of +them have pseudoknots + +like these ones shown +here, and some even + +have these kissing loops, +which is another type where + +the two stem loops, +the loops interact. + +And the pseudoknots +in particular + +are important in the +viral life cycle. + +They can actually cause +programmed ribosomal frame + +shifting. + +When the ribosomes +hits one of the things, + +normally it just denatures +RNA secondary structure. + +When it hits a +pseudoknot, it'll actually + +get knocked back by +one and will start + +translating in a +different frame. + +And that's actually +useful to the virus + +to do that under +certain circumstances. + +That's how HIV makes the +replicated polymerase, + +is by doing a frame shift on +the ribosome using a pseudoknot. + +So these things are important. + +And there's fancier +methods that use + +more sophisticated +thermodynamic models where + +GC counts more than AU. + +And I won't go into +the details, but I just + +wanted to show you some +pretty pictures here + +that the Zuker +algorithm-- this is + +a real world RNA folding +algorithm-- calculates not only + +the minimum energy fold, +but also sub-optimal folds, + +and the probabilities of +particular base pairs, + +summing over all the possible +structures that RNA could form, + +weighted by their free energy. + +So it's the full +partition function. + +It's not perfectly accurate. + +It gets about 70% of +base pairs correct, + +which means it usually +gets things right, + +but occasionally totally wrong. + +And there's a website for the +Mfold server, which is actually + +one of the most beautiful +websites in bioinfomatics, + +I would say. + +And also if you want +to run it locally, + +you should download the +Vienna RNAfold package, + +which has a very +similar algorithm. + +And I just wanted to show +you one or two examples. + +So this is the U5 snRNA. + +This is the output of Mfold. + +It predicts this structure. + +And then this what's called +the energy dot plot, which + +shows the bases in the optimal +structure down below here + +and then sort of these +suboptimal structures here. + +And you can see +there's no ambiguity. + +It's totally confident +in this structure. + +Then I ran the lysine +riboswitch through this program, + +and I got this. + +I got the minimum +for energy structure + +down in the lower left. + +And then you see there's a +lot of other colored dots. + +Those are from the +suboptimal structures. + +So it looks like this thing +has multiple structures, which + +of course it does. + +So the way that this one works +is, in the absence of lysine, + +it forms this structure +where the ribosome binding + +sequences-- this is +prokaryotic-- is exposed. + +And so the ribosome +can enter and translate + +these lysine +biosynthetic enzymes. + +But then when lysine +accumulates to a certain level, + +it can interact with the +RNA and shift it's structure + +so that you now form +this stem, which + +sequesters the ribosome +binding sequence + +and blocks lysine biosynthesis. + +So a very clever system. + +And it turns out +that there's dozens + +of these things in +bacterial genomes, + +and they control a +lot of metabolism. + +So they're very important. + +And there may be some +in eukaryotes, too, + +and that would be good. + +If anyone's looking for +a product, not happy + +with their current +project, you might + +think about looking +for more riboswitches. + +So I'm going to +have to end there. + +And thank you guys +for your attention, + +and good luck on the midterm. \ No newline at end of file diff --git a/lE217O9ZGws.txt b/lE217O9ZGws.txt new file mode 100644 index 0000000000000000000000000000000000000000..249139deebd1b2e7d98f646171bc9c5863b9f56f --- /dev/null +++ b/lE217O9ZGws.txt @@ -0,0 +1,1635 @@ +align:start position:0% + +during this course when we've had the + + align:start position:0% +during this course when we've had the + + + align:start position:0% +during this course when we've had the +need to plot a map we use the code that + + align:start position:0% +need to plot a map we use the code that + + + align:start position:0% +need to plot a map we use the code that +is provided by default by R uh but there + + align:start position:0% +is provided by default by R uh but there + + + align:start position:0% +is provided by default by R uh but there +are other ways to plot maps and make + + align:start position:0% +are other ways to plot maps and make + + + align:start position:0% +are other ways to plot maps and make +them easy to be tuned according on our + + align:start position:0% +them easy to be tuned according on our + + + align:start position:0% +them easy to be tuned according on our +taste so now I'm going to show you how + + align:start position:0% +taste so now I'm going to show you how + + + align:start position:0% +taste so now I'm going to show you how +to display nice map + + align:start position:0% +to display nice map + + + align:start position:0% +to display nice map +um that are easy to tune using ggplot + + align:start position:0% +um that are easy to tune using ggplot + + + align:start position:0% +um that are easy to tune using ggplot +and to do that I'm going to charge the + + align:start position:0% +and to do that I'm going to charge the + + + align:start position:0% +and to do that I'm going to charge the +map that we've been using our friend + + align:start position:0% +map that we've been using our friend + + + align:start position:0% +map that we've been using our friend +this temperature map um also to make the + + align:start position:0% +this temperature map um also to make the + + + align:start position:0% +this temperature map um also to make the +process easier or faster for R I'm going + + align:start position:0% +process easier or faster for R I'm going + + + align:start position:0% +process easier or faster for R I'm going +to aggregate this map to make it coarser + + align:start position:0% +to aggregate this map to make it coarser + + + align:start position:0% +to aggregate this map to make it coarser +uh in this case I'm going to use a + + align:start position:0% +uh in this case I'm going to use a + + + align:start position:0% +uh in this case I'm going to use a +factor of five so it means that from + + align:start position:0% +factor of five so it means that from + + + align:start position:0% +factor of five so it means that from +each five pixels I'm just creating one + + align:start position:0% +each five pixels I'm just creating one + + + align:start position:0% +each five pixels I'm just creating one +uh that's going to affect it's going to + + align:start position:0% +uh that's going to affect it's going to + + + align:start position:0% +uh that's going to affect it's going to +affect the result in this case it's + + align:start position:0% +affect the result in this case it's + + + align:start position:0% +affect the result in this case it's +going to + + align:start position:0% +going to + + + align:start position:0% +going to +make the image to be um less defined but + + align:start position:0% +make the image to be um less defined but + + + align:start position:0% +make the image to be um less defined but +this is just because we aggregated the + + align:start position:0% +this is just because we aggregated the + + + align:start position:0% +this is just because we aggregated the +data and we also need to transform this + + align:start position:0% +data and we also need to transform this + + + align:start position:0% +data and we also need to transform this +map into a data frame this is a + + align:start position:0% +map into a data frame this is a + + + align:start position:0% +map into a data frame this is a +requirement to be able to plot it with + + align:start position:0% +requirement to be able to plot it with + + + align:start position:0% +requirement to be able to plot it with +uh + + align:start position:0% +uh + + + align:start position:0% +uh +ggplot um so that's what I'm doing here + + align:start position:0% +ggplot um so that's what I'm doing here + + + align:start position:0% +ggplot um so that's what I'm doing here +as data frame by default this command is + + align:start position:0% +as data frame by default this command is + + + align:start position:0% +as data frame by default this command is +not included so this means that when + + align:start position:0% +not included so this means that when + + + align:start position:0% +not included so this means that when +transforming the map into a data frame + + align:start position:0% +transforming the map into a data frame + + + align:start position:0% +transforming the map into a data frame +we are maintaining latitude and + + align:start position:0% +we are maintaining latitude and + + + align:start position:0% +we are maintaining latitude and +longitude as a variable by default this + + align:start position:0% +longitude as a variable by default this + + + align:start position:0% +longitude as a variable by default this +is false so it wouldn't be well I'm just + + align:start position:0% +is false so it wouldn't be well I'm just + + + align:start position:0% +is false so it wouldn't be well I'm just +going to show you how it how it is by + + align:start position:0% +going to show you how it how it is by + + + align:start position:0% +going to show you how it how it is by +default see we only have one variable + + align:start position:0% +default see we only have one variable + + + align:start position:0% +default see we only have one variable +but in this case if we would give this + + align:start position:0% +but in this case if we would give this + + + align:start position:0% +but in this case if we would give this +to ggplot um that wouldn't be able to + + align:start position:0% +to ggplot um that wouldn't be able to + + + align:start position:0% +to ggplot um that wouldn't be able to +provide us a map because X and Y would + + align:start position:0% +provide us a map because X and Y would + + + align:start position:0% +provide us a map because X and Y would +be lacking so we need to include this + + align:start position:0% +be lacking so we need to include this + + + align:start position:0% +be lacking so we need to include this +chunk of code here that's going to give + + align:start position:0% +chunk of code here that's going to give + + + align:start position:0% +chunk of code here that's going to give +us the latitude to longitude ude so now + + align:start position:0% +us the latitude to longitude ude so now + + + align:start position:0% +us the latitude to longitude ude so now +we have three variables instead of one + + align:start position:0% +we have three variables instead of one + + + align:start position:0% +we have three variables instead of one +and if we click on here we have the X + + align:start position:0% +and if we click on here we have the X + + + align:start position:0% +and if we click on here we have the X +the Y and that's the name of the map + + align:start position:0% +the Y and that's the name of the map + + + align:start position:0% +the Y and that's the name of the map +that we've used just because it's very + + align:start position:0% +that we've used just because it's very + + + align:start position:0% +that we've used just because it's very +long and not easy to work with I decided + + align:start position:0% +long and not easy to work with I decided + + + align:start position:0% +long and not easy to work with I decided +to change that name into temp of + + align:start position:0% +to change that name into temp of + + + align:start position:0% +to change that name into temp of +temperature so that's what I'm doing + + align:start position:0% +temperature so that's what I'm doing + + + align:start position:0% +temperature so that's what I'm doing +here and I'm going to charge the + + align:start position:0% +here and I'm going to charge the + + + align:start position:0% +here and I'm going to charge the +packages we're going to need to do this + + align:start position:0% +packages we're going to need to do this + + + align:start position:0% +packages we're going to need to do this +process which is the map tools that is + + align:start position:0% +process which is the map tools that is + + + align:start position:0% +process which is the map tools that is +related to working with maps then we + + align:start position:0% +related to working with maps then we + + + align:start position:0% +related to working with maps then we +have the G plot 2 which um + + align:start position:0% +have the G plot 2 which um + + + align:start position:0% +have the G plot 2 which um +is the main package we're going to be + + align:start position:0% +is the main package we're going to be + + + align:start position:0% +is the main package we're going to be +using here and then we have this bis + + align:start position:0% +using here and then we have this bis + + + align:start position:0% +using here and then we have this bis +that is about the color palette we're + + align:start position:0% +that is about the color palette we're + + + align:start position:0% +that is about the color palette we're +going to use to create the + + align:start position:0% +going to use to create the + + + align:start position:0% +going to use to create the +map and I'm going to also charge this + + align:start position:0% +map and I'm going to also charge this + + + align:start position:0% +map and I'm going to also charge this +map that we've been using which is the + + align:start position:0% +map that we've been using which is the + + + align:start position:0% +map that we've been using which is the +one that separates um the water bodies + + align:start position:0% +one that separates um the water bodies + + + align:start position:0% +one that separates um the water bodies +so it's the shape of the + + align:start position:0% +so it's the shape of the + + + align:start position:0% +so it's the shape of the +ground and this would be the most + + align:start position:0% +ground and this would be the most + + + align:start position:0% +ground and this would be the most +simple code that would give us a map + + align:start position:0% +simple code that would give us a map + + + align:start position:0% +simple code that would give us a map +using ggplot so the this part here would + + align:start position:0% +using ggplot so the this part here would + + + align:start position:0% +using ggplot so the this part here would +not be necessary we could erase it but + + align:start position:0% +not be necessary we could erase it but + + + align:start position:0% +not be necessary we could erase it but +in this case I I am storing this code + + align:start position:0% +in this case I I am storing this code + + + align:start position:0% +in this case I I am storing this code +into this + + align:start position:0% +into this + + + align:start position:0% +into this +object um so I am saying R to r that I'm + + align:start position:0% +object um so I am saying R to r that I'm + + + align:start position:0% +object um so I am saying R to r that I'm +going to be using ggplot and our base + + align:start position:0% +going to be using ggplot and our base + + + align:start position:0% +going to be using ggplot and our base +it's going to be this data frame I'm + + align:start position:0% +it's going to be this data frame I'm + + + align:start position:0% +it's going to be this data frame I'm +going to add a plus I'm going to say to + + align:start position:0% +going to add a plus I'm going to say to + + + align:start position:0% +going to add a plus I'm going to say to +ggplot what do I want + + align:start position:0% +ggplot what do I want + + + align:start position:0% +ggplot what do I want +me why do I want GG plot to provide in + + align:start position:0% +me why do I want GG plot to provide in + + + align:start position:0% +me why do I want GG plot to provide in +this case I want to have a Gom raster so + + align:start position:0% +this case I want to have a Gom raster so + + + align:start position:0% +this case I want to have a Gom raster so +I want gplot to give me a raster based + + align:start position:0% +I want gplot to give me a raster based + + + align:start position:0% +I want gplot to give me a raster based +on this as an X this as a y so we could + + align:start position:0% +on this as an X this as a y so we could + + + align:start position:0% +on this as an X this as a y so we could +we could type it here and it would work + + align:start position:0% +we could type it here and it would work + + + align:start position:0% +we could type it here and it would work +equal way just if x or y would have + + align:start position:0% +equal way just if x or y would have + + + align:start position:0% +equal way just if x or y would have +different names it would have to specify + + align:start position:0% +different names it would have to specify + + + align:start position:0% +different names it would have to specify +these names right here and then in fill + + align:start position:0% +these names right here and then in fill + + + align:start position:0% +these names right here and then in fill +um I want ggplot to fill this X and Y + + align:start position:0% +um I want ggplot to fill this X and Y + + + align:start position:0% +um I want ggplot to fill this X and Y +with the temperature which is the third + + align:start position:0% +with the temperature which is the third + + + align:start position:0% +with the temperature which is the third +column that we have in that data frame + + align:start position:0% +column that we have in that data frame + + + align:start position:0% +column that we have in that data frame +so let's just run this piece of + + align:start position:0% +so let's just run this piece of + + + align:start position:0% +so let's just run this piece of +coat and see how it looks + + align:start position:0% + + + + align:start position:0% + +like okay this is clearly not the most + + align:start position:0% +like okay this is clearly not the most + + + align:start position:0% +like okay this is clearly not the most +beautiful plot you could have ever seen + + align:start position:0% +beautiful plot you could have ever seen + + + align:start position:0% +beautiful plot you could have ever seen +so but this is just the basic and we're + + align:start position:0% +so but this is just the basic and we're + + + align:start position:0% +so but this is just the basic and we're +going to keep improving this map line by + + align:start position:0% +going to keep improving this map line by + + + align:start position:0% +going to keep improving this map line by +line so you can see how each piece of + + align:start position:0% +line so you can see how each piece of + + + align:start position:0% +line so you can see how each piece of +code changes the result of the map we're + + align:start position:0% +code changes the result of the map we're + + + align:start position:0% +code changes the result of the map we're +going to + + align:start position:0% +going to + + + align:start position:0% +going to +have um first of all what I want to + + align:start position:0% +have um first of all what I want to + + + align:start position:0% +have um first of all what I want to +include here is the shape of the Earth + + align:start position:0% +include here is the shape of the Earth + + + align:start position:0% +include here is the shape of the Earth +so I want to include that map that we + + align:start position:0% +so I want to include that map that we + + + align:start position:0% +so I want to include that map that we +just uploaded on top of this one um to + + align:start position:0% +just uploaded on top of this one um to + + + align:start position:0% +just uploaded on top of this one um to +make a good differentiation between + + align:start position:0% +make a good differentiation between + + + align:start position:0% +make a good differentiation between +what's what's the C and what's not um so + + align:start position:0% +what's what's the C and what's not um so + + + align:start position:0% +what's what's the C and what's not um so +that's why I included this piece of code + + align:start position:0% +that's why I included this piece of code + + + align:start position:0% +that's why I included this piece of code +here I'm going to erase this plus to + + align:start position:0% +here I'm going to erase this plus to + + + align:start position:0% +here I'm going to erase this plus to +make the code to stop right here and see + + align:start position:0% +make the code to stop right here and see + + + align:start position:0% +make the code to stop right here and see +how that looks + + align:start position:0% + + + + align:start position:0% + +like okay now we has this we have this + + align:start position:0% +like okay now we has this we have this + + + align:start position:0% +like okay now we has this we have this +nice black line + + align:start position:0% +nice black line + + + align:start position:0% +nice black line +around um but now it turns out that I + + align:start position:0% +around um but now it turns out that I + + + align:start position:0% +around um but now it turns out that I +don't + + align:start position:0% +don't + + + align:start position:0% +don't +want this black shape here and I want to + + align:start position:0% +want this black shape here and I want to + + + align:start position:0% +want this black shape here and I want to +change the color palette so to do that + + align:start position:0% +change the color palette so to do that + + + align:start position:0% +change the color palette so to do that +I'm going to include this piece of coat + + align:start position:0% +I'm going to include this piece of coat + + + align:start position:0% +I'm going to include this piece of coat +as + + align:start position:0% + + + + align:start position:0% + +well right here and I'm saying that the + + align:start position:0% +well right here and I'm saying that the + + + align:start position:0% +well right here and I'm saying that the +na values are going to be na so I'm + + align:start position:0% +na values are going to be na so I'm + + + align:start position:0% +na values are going to be na so I'm +asking this code not to show me the Naas + + align:start position:0% +asking this code not to show me the Naas + + + align:start position:0% +asking this code not to show me the Naas +so that's going to erase this gray area + + align:start position:0% +so that's going to erase this gray area + + + align:start position:0% +so that's going to erase this gray area +here here also I'm going to change the + + align:start position:0% +here here also I'm going to change the + + + align:start position:0% +here here also I'm going to change the +direction of the color palette meaning + + align:start position:0% +direction of the color palette meaning + + + align:start position:0% +direction of the color palette meaning +that now the the + + align:start position:0% +that now the the + + + align:start position:0% +that now the the +black the black color is related to + + align:start position:0% +black the black color is related to + + + align:start position:0% +black the black color is related to +lower temperatures and I want it the + + align:start position:0% +lower temperatures and I want it the + + + align:start position:0% +lower temperatures and I want it the +other way around and also I am changing + + align:start position:0% +other way around and also I am changing + + + align:start position:0% +other way around and also I am changing +the color palette to have this shape if + + align:start position:0% +the color palette to have this shape if + + + align:start position:0% +the color palette to have this shape if +we go to the help with FN and F1 here we + + align:start position:0% +we go to the help with FN and F1 here we + + + align:start position:0% +we go to the help with FN and F1 here we +see that this the + + align:start position:0% +see that this the + + + align:start position:0% +see that this the +beginning of the help section + + align:start position:0% +beginning of the help section + + + align:start position:0% +beginning of the help section +if we scroll down we get to the + + align:start position:0% +if we scroll down we get to the + + + align:start position:0% +if we scroll down we get to the +different options we have for color + + align:start position:0% +different options we have for color + + + align:start position:0% +different options we have for color +palette these are the different options + + align:start position:0% +palette these are the different options + + + align:start position:0% +palette these are the different options +we have so if instead of this letter + + align:start position:0% +we have so if instead of this letter + + + align:start position:0% +we have so if instead of this letter +here I put an a b or c we would have + + align:start position:0% +here I put an a b or c we would have + + + align:start position:0% +here I put an a b or c we would have +different color palettes as an outcome I + + align:start position:0% +different color palettes as an outcome I + + + align:start position:0% +different color palettes as an outcome I +chose this one just + + align:start position:0% + + + + align:start position:0% + +because this is how our + + align:start position:0% +because this is how our + + + align:start position:0% +because this is how our +map has + + align:start position:0% + + + + align:start position:0% + +changed + + align:start position:0% +changed + + + align:start position:0% +changed +oh I have to run it first of + + align:start position:0% + + + + align:start position:0% + +course and I have to put a plus because + + align:start position:0% +course and I have to put a plus because + + + align:start position:0% +course and I have to put a plus because +otherwise it wouldn't read this new line + + align:start position:0% +otherwise it wouldn't read this new line + + + align:start position:0% +otherwise it wouldn't read this new line +that I + + align:start position:0% + + + + align:start position:0% + +added okay I have changed the direction + + align:start position:0% +added okay I have changed the direction + + + align:start position:0% +added okay I have changed the direction +of the color palette as you can see now + + align:start position:0% +of the color palette as you can see now + + + align:start position:0% +of the color palette as you can see now +this gray area around has + + align:start position:0% +this gray area around has + + + align:start position:0% +this gray area around has +disappeared and the color palette also + + align:start position:0% +disappeared and the color palette also + + + align:start position:0% +disappeared and the color palette also +has changed I still want to keep + + align:start position:0% +has changed I still want to keep + + + align:start position:0% +has changed I still want to keep +improving this map because I don't like + + align:start position:0% +improving this map because I don't like + + + align:start position:0% +improving this map because I don't like +this background here that's something + + align:start position:0% +this background here that's something + + + align:start position:0% +this background here that's something +called the theme of the map uh you can + + align:start position:0% +called the theme of the map uh you can + + + align:start position:0% +called the theme of the map uh you can +change the theme um and in this case I + + align:start position:0% +change the theme um and in this case I + + + align:start position:0% +change the theme um and in this case I +want the theme + + align:start position:0% +want the theme + + + align:start position:0% +want the theme +minimal and I also don't like this chunk + + align:start position:0% +minimal and I also don't like this chunk + + + align:start position:0% +minimal and I also don't like this chunk +to be displayed so I decided to reduce + + align:start position:0% +to be displayed so I decided to reduce + + + align:start position:0% +to be displayed so I decided to reduce +the Y limits of the Y AIS and instead of + + align:start position:0% +the Y limits of the Y AIS and instead of + + + align:start position:0% +the Y limits of the Y AIS and instead of +being their total extent I'm just going + + align:start position:0% +being their total extent I'm just going + + + align:start position:0% +being their total extent I'm just going +to cut it at minus 60 so it's going to + + align:start position:0% +to cut it at minus 60 so it's going to + + + align:start position:0% +to cut it at minus 60 so it's going to +be cut somewhere like here um to do so + + align:start position:0% +be cut somewhere like here um to do so + + + align:start position:0% +be cut somewhere like here um to do so +just going to CP them + + align:start position:0% +just going to CP them + + + align:start position:0% +just going to CP them +plus this + + align:start position:0% +plus this + + + align:start position:0% +plus this +out make it nicer and + + align:start position:0% +out make it nicer and + + + align:start position:0% +out make it nicer and +close just run it and see how these + + align:start position:0% +close just run it and see how these + + + align:start position:0% +close just run it and see how these +affect our + + align:start position:0% + + + + align:start position:0% + +map okay now we + + align:start position:0% +map okay now we + + + align:start position:0% +map okay now we +changed that great area we had in the + + align:start position:0% +changed that great area we had in the + + + align:start position:0% +changed that great area we had in the +background as well and we are no longer + + align:start position:0% +background as well and we are no longer + + + align:start position:0% +background as well and we are no longer +displaying the southern + + align:start position:0% +displaying the southern + + + align:start position:0% +displaying the southern +latitudes um now I want + + align:start position:0% +latitudes um now I want + + + align:start position:0% +latitudes um now I want +this to + + align:start position:0% +this to + + + align:start position:0% +this to +have a title and I want this to have + + align:start position:0% +have a title and I want this to have + + + align:start position:0% +have a title and I want this to have +also like not display this or + + align:start position:0% +also like not display this or + + + align:start position:0% +also like not display this or +that and I want to change the legend + + align:start position:0% +that and I want to change the legend + + + align:start position:0% +that and I want to change the legend +position instead of being on the right I + + align:start position:0% +position instead of being on the right I + + + align:start position:0% +position instead of being on the right I +want it to be on the left so all these + + align:start position:0% +want it to be on the left so all these + + + align:start position:0% +want it to be on the left so all these +changes are the ones that are + + align:start position:0% +changes are the ones that are + + + align:start position:0% +changes are the ones that are +implemented here this is not displaying + + align:start position:0% +implemented here this is not displaying + + + align:start position:0% +implemented here this is not displaying +X and Y um laps + + align:start position:0% +X and Y um laps + + + align:start position:0% +X and Y um laps +here this is going to be to change the + + align:start position:0% +here this is going to be to change the + + + align:start position:0% +here this is going to be to change the +position of the Legend um this is the + + align:start position:0% +position of the Legend um this is the + + + align:start position:0% +position of the Legend um this is the +title and this is going to + + align:start position:0% +title and this is going to + + + align:start position:0% +title and this is going to +change this here instead of temp I + + align:start position:0% +change this here instead of temp I + + + align:start position:0% +change this here instead of temp I +wanted to explain that it's the jary + + align:start position:0% +wanted to explain that it's the jary + + + align:start position:0% +wanted to explain that it's the jary +temperature so I'm going to include them + + align:start position:0% +temperature so I'm going to include them + + + align:start position:0% +temperature so I'm going to include them +all + + align:start position:0% + + + + align:start position:0% + +together + + align:start position:0% + + + + align:start position:0% + +and this is an example of how we + + align:start position:0% +and this is an example of how we + + + align:start position:0% +and this is an example of how we +can create and tune outcomes in a nice + + align:start position:0% +can create and tune outcomes in a nice + + + align:start position:0% +can create and tune outcomes in a nice +way uh so we can use this outcome as a a + + align:start position:0% +way uh so we can use this outcome as a a + + + align:start position:0% +way uh so we can use this outcome as a a +graphic representation in our uh + + align:start position:0% +graphic representation in our uh + + + align:start position:0% +graphic representation in our uh +scientific + + align:start position:0% +scientific + + + align:start position:0% +scientific +projects um okay this looks kind of nice + + align:start position:0% +projects um okay this looks kind of nice + + + align:start position:0% +projects um okay this looks kind of nice +and tidy here but what if we want to + + align:start position:0% +and tidy here but what if we want to + + + align:start position:0% +and tidy here but what if we want to +extract this image and store it in our + + align:start position:0% +extract this image and store it in our + + + align:start position:0% +extract this image and store it in our +computer a nice way to do it is using + + align:start position:0% +computer a nice way to do it is using + + + align:start position:0% +computer a nice way to do it is using +Tif extension uh what I have to do is + + align:start position:0% +Tif extension uh what I have to do is + + + align:start position:0% +Tif extension uh what I have to do is +just to write Tif write the file name + + align:start position:0% +just to write Tif write the file name + + + align:start position:0% +just to write Tif write the file name +where I want to um create or generate um + + align:start position:0% +where I want to um create or generate um + + + align:start position:0% +where I want to um create or generate um +this outcome the how big I want this + + align:start position:0% +this outcome the how big I want this + + + align:start position:0% +this outcome the how big I want this +image to be the resolution by default is + + align:start position:0% +image to be the resolution by default is + + + align:start position:0% +image to be the resolution by default is +100 I just put 200 here to make + + align:start position:0% +100 I just put 200 here to make + + + align:start position:0% +100 I just put 200 here to make +everything appear + + align:start position:0% +everything appear + + + align:start position:0% +everything appear +bigger and then you have to include here + + align:start position:0% +bigger and then you have to include here + + + align:start position:0% +bigger and then you have to include here +what's the object you want to store in + + align:start position:0% +what's the object you want to store in + + + align:start position:0% +what's the object you want to store in +that um object you just created and then + + align:start position:0% +that um object you just created and then + + + align:start position:0% +that um object you just created and then +click + + align:start position:0% +click + + + align:start position:0% +click +on this part which is giving the order + + align:start position:0% +on this part which is giving the order + + + align:start position:0% +on this part which is giving the order +to our to close that file and give it as + + align:start position:0% +to our to close that file and give it as + + + align:start position:0% +to our to close that file and give it as +a as an outcome so you can consult in + + align:start position:0% +a as an outcome so you can consult in + + + align:start position:0% +a as an outcome so you can consult in +your computer and use it um uh at your + + align:start position:0% + + + + align:start position:0% + +convenience \ No newline at end of file diff --git a/lwhXMAu0SnI.txt b/lwhXMAu0SnI.txt new file mode 100644 index 0000000000000000000000000000000000000000..ffeceda72605fedc36df5c66a45883bc5c12d283 --- /dev/null +++ b/lwhXMAu0SnI.txt @@ -0,0 +1,15723 @@ +align:start position:0% + +okay uh let me go ahead and get started + + align:start position:0% +okay uh let me go ahead and get started + + + align:start position:0% +okay uh let me go ahead and get started +so um uh you know today's topic um is + + align:start position:0% +so um uh you know today's topic um is + + + align:start position:0% +so um uh you know today's topic um is +going to be um entry and you know I + + align:start position:0% +going to be um entry and you know I + + + align:start position:0% +going to be um entry and you know I +think entry is an incredibly important + + align:start position:0% +think entry is an incredibly important + + + align:start position:0% +think entry is an incredibly important +topic in Iowa in fact you like one of + + align:start position:0% +topic in Iowa in fact you like one of + + + align:start position:0% +topic in Iowa in fact you like one of +the messages I'm going to talk about + + align:start position:0% +the messages I'm going to talk about + + + align:start position:0% +the messages I'm going to talk about +today is in some sense just about + + align:start position:0% +today is in some sense just about + + + align:start position:0% +today is in some sense just about +everything we've done in this semester + + align:start position:0% +everything we've done in this semester + + + align:start position:0% +everything we've done in this semester +so far is kind of like rounding error + + align:start position:0% +so far is kind of like rounding error + + + align:start position:0% +so far is kind of like rounding error +compared to what what we do now so um + + align:start position:0% +compared to what what we do now so um + + + align:start position:0% +compared to what what we do now so um +you know how do I think about entry um + + align:start position:0% +you know how do I think about entry um + + + align:start position:0% +you know how do I think about entry um +so you know so far we've talked about a + + align:start position:0% +so you know so far we've talked about a + + + align:start position:0% +so you know so far we've talked about a +lot of models that have uh the number of + + align:start position:0% +lot of models that have uh the number of + + + align:start position:0% +lot of models that have uh the number of +firms fixed and I've talked about lots + + align:start position:0% +firms fixed and I've talked about lots + + + align:start position:0% +firms fixed and I've talked about lots +of things about factors that affect + + align:start position:0% +of things about factors that affect + + + align:start position:0% +of things about factors that affect +pricing with the number of firms fixed + + align:start position:0% +pricing with the number of firms fixed + + + align:start position:0% +pricing with the number of firms fixed +you know Monopoly pricing if you have + + align:start position:0% +you know Monopoly pricing if you have + + + align:start position:0% +you know Monopoly pricing if you have +one firm how does that what what do they + + align:start position:0% +one firm how does that what what do they + + + align:start position:0% +one firm how does that what what do they +do and then you know static competition + + align:start position:0% +do and then you know static competition + + + align:start position:0% +do and then you know static competition +with vertical differentiation or + + align:start position:0% +with vertical differentiation or + + + align:start position:0% +with vertical differentiation or +horizontal differentiation or search + + align:start position:0% +horizontal differentiation or search + + + align:start position:0% +horizontal differentiation or search +costs or other things and it's always + + align:start position:0% +costs or other things and it's always + + + align:start position:0% +costs or other things and it's always +sort of the nature of the market is + + align:start position:0% +sort of the nature of the market is + + + align:start position:0% +sort of the nature of the market is +determining what's the level of markups + + align:start position:0% +determining what's the level of markups + + + align:start position:0% +determining what's the level of markups +and what inefficiencies there might + + align:start position:0% +and what inefficiencies there might + + + align:start position:0% +and what inefficiencies there might +be um but that's all taking Market + + align:start position:0% +be um but that's all taking Market + + + align:start position:0% +be um but that's all taking Market +structure is fixed and so you know + + align:start position:0% +structure is fixed and so you know + + + align:start position:0% +structure is fixed and so you know +starting today I'm going to think about + + align:start position:0% +starting today I'm going to think about + + + align:start position:0% +starting today I'm going to think about +like what happens if you allow the + + align:start position:0% +like what happens if you allow the + + + align:start position:0% +like what happens if you allow the +number of firms to change and so the + + align:start position:0% +number of firms to change and so the + + + align:start position:0% +number of firms to change and so the +simplest way to think about this is + + align:start position:0% +simplest way to think about this is + + + align:start position:0% +simplest way to think about this is +let's look at a two-stage models I'm + + align:start position:0% +let's look at a two-stage models I'm + + + align:start position:0% +let's look at a two-stage models I'm +going to start with the case of + + align:start position:0% +going to start with the case of + + + align:start position:0% +going to start with the case of +homogeneous Goods you can think of this + + align:start position:0% +homogeneous Goods you can think of this + + + align:start position:0% +homogeneous Goods you can think of this +as you know old-fashioned steel plants + + align:start position:0% +as you know old-fashioned steel plants + + + align:start position:0% +as you know old-fashioned steel plants +entering and each producing cold rolled + + align:start position:0% +entering and each producing cold rolled + + + align:start position:0% +entering and each producing cold rolled +steel or aluminum plants or S some + + align:start position:0% +steel or aluminum plants or S some + + + align:start position:0% +steel or aluminum plants or S some +industry that has a small number of + + align:start position:0% +industry that has a small number of + + + align:start position:0% +industry that has a small number of +firms because they're big sort of fixed + + align:start position:0% +firms because they're big sort of fixed + + + align:start position:0% +firms because they're big sort of fixed +cost of setting up plants and then they + + align:start position:0% +cost of setting up plants and then they + + + align:start position:0% +cost of setting up plants and then they +compete with each other so stage one we + + align:start position:0% +compete with each other so stage one we + + + align:start position:0% +compete with each other so stage one we +have a large number of potential + + align:start position:0% +have a large number of potential + + + align:start position:0% +have a large number of potential +entrance the potential entrance choose + + align:start position:0% +entrance the potential entrance choose + + + align:start position:0% +entrance the potential entrance choose +in or out if they decide to come in they + + align:start position:0% +in or out if they decide to come in they + + + align:start position:0% +in or out if they decide to come in they +pay some fixed entry cost K and I'm + + align:start position:0% +pay some fixed entry cost K and I'm + + + align:start position:0% +pay some fixed entry cost K and I'm +going to think about this as the most of + + align:start position:0% +going to think about this as the most of + + + align:start position:0% +going to think about this as the most of +the lecture is a sunk cost that is like + + align:start position:0% +the lecture is a sunk cost that is like + + + align:start position:0% +the lecture is a sunk cost that is like +once you build a steel plant it's a + + align:start position:0% +once you build a steel plant it's a + + + align:start position:0% +once you build a steel plant it's a +steel plant you can't use it for + + align:start position:0% +steel plant you can't use it for + + + align:start position:0% +steel plant you can't use it for +anything else you're not going to be + + align:start position:0% +anything else you're not going to be + + + align:start position:0% +anything else you're not going to be +able to sell it to somebody else to do + + align:start position:0% +able to sell it to somebody else to do + + + align:start position:0% +able to sell it to somebody else to do +something else with it um firms that + + align:start position:0% +something else with it um firms that + + + align:start position:0% +something else with it um firms that +choose to enter Then play some game like + + align:start position:0% +choose to enter Then play some game like + + + align:start position:0% +choose to enter Then play some game like +betran competition Cordo competition + + align:start position:0% +betran competition Cordo competition + + + align:start position:0% +betran competition Cordo competition +price competition with search Etc and + + align:start position:0% +price competition with search Etc and + + + align:start position:0% +price competition with search Etc and +assume firms have some variable costs um + + align:start position:0% +assume firms have some variable costs um + + + align:start position:0% +assume firms have some variable costs um +C of Q and then so how you going to + + align:start position:0% +C of Q and then so how you going to + + + align:start position:0% +C of Q and then so how you going to +solve this model I'm going to solve this + + align:start position:0% +solve this model I'm going to solve this + + + align:start position:0% +solve this model I'm going to solve this +model by backward induction you know I + + align:start position:0% +model by backward induction you know I + + + align:start position:0% +model by backward induction you know I +first start with the second stage in the + + align:start position:0% +first start with the second stage in the + + + align:start position:0% +first start with the second stage in the +second + + align:start position:0% +second + + + align:start position:0% +second +stage if they're n firms there going to + + align:start position:0% +stage if they're n firms there going to + + + align:start position:0% +stage if they're n firms there going to +be some equal ibrium price is p star of + + align:start position:0% +be some equal ibrium price is p star of + + + align:start position:0% +be some equal ibrium price is p star of +n um P star of n * qar of n minus C of + + align:start position:0% +n um P star of n * qar of n minus C of + + + align:start position:0% +n um P star of n * qar of n minus C of +qar of n is going to be the variable + + align:start position:0% +qar of n is going to be the variable + + + align:start position:0% +qar of n is going to be the variable +profits of the firms good if they enter + + align:start position:0% +profits of the firms good if they enter + + + align:start position:0% +profits of the firms good if they enter +and then you find the number of + + align:start position:0% +and then you find the number of + + + align:start position:0% +and then you find the number of +equilibrium entrance by looking at the + + align:start position:0% +equilibrium entrance by looking at the + + + align:start position:0% +equilibrium entrance by looking at the +first + + align:start position:0% +first + + + align:start position:0% +first +stage + + align:start position:0% +stage + + + align:start position:0% +stage +right and what's that going to be um + + align:start position:0% +right and what's that going to be um + + + align:start position:0% +right and what's that going to be um +okay first comment I guess these slides + + align:start position:0% +okay first comment I guess these slides + + + align:start position:0% +okay first comment I guess these slides +were made up in the co era where I would + + align:start position:0% +were made up in the co era where I would + + + align:start position:0% +were made up in the co era where I would +write on + + align:start position:0% +write on + + + align:start position:0% +write on +them uh write on my iPad but let me go + + align:start position:0% +them uh write on my iPad but let me go + + + align:start position:0% +them uh write on my iPad but let me go +ahead and do this on the board Bo + + align:start position:0% +ahead and do this on the board Bo + + + align:start position:0% +ahead and do this on the board Bo +so you know let me + + align:start position:0% +so you know let me + + + align:start position:0% +so you know let me +graph um what a profits look like as a + + align:start position:0% +graph um what a profits look like as a + + + align:start position:0% +graph um what a profits look like as a +function of the number of firms the + + align:start position:0% +function of the number of firms the + + + align:start position:0% +function of the number of firms the +easiest one to graph uh is + + align:start position:0% +easiest one to graph uh is + + + align:start position:0% +easiest one to graph uh is +Bertrand so one two three four five um + + align:start position:0% +Bertrand so one two three four five um + + + align:start position:0% +Bertrand so one two three four five um +you know betran + + align:start position:0% +you know betran + + + align:start position:0% +you know betran +competition you have this level of + + align:start position:0% +competition you have this level of + + + align:start position:0% +competition you have this level of +um profits PM if you have one firm uh + + align:start position:0% +um profits PM if you have one firm uh + + + align:start position:0% +um profits PM if you have one firm uh +and then as soon as you have two + + align:start position:0% +and then as soon as you have two + + + align:start position:0% +and then as soon as you have two +firms uh profits drop to zero another + + align:start position:0% +firms uh profits drop to zero another + + + align:start position:0% +firms uh profits drop to zero another +thing you could have is Coro + + align:start position:0% +thing you could have is Coro + + + align:start position:0% +thing you could have is Coro +competition uh if you have Coro + + align:start position:0% +competition uh if you have Coro + + + align:start position:0% +competition uh if you have Coro +competition you get exactly the same + + align:start position:0% +competition you get exactly the same + + + align:start position:0% +competition you get exactly the same +outcome when n equals + + align:start position:0% +outcome when n equals + + + align:start position:0% +outcome when n equals +1 uh but then profits sort of + + align:start position:0% +1 uh but then profits sort of + + + align:start position:0% +1 uh but then profits sort of +drop when you add two + + align:start position:0% +drop when you add two + + + align:start position:0% +drop when you add two +three four five whatever firms right if + + align:start position:0% +three four five whatever firms right if + + + align:start position:0% +three four five whatever firms right if +you think about like right if we did + + align:start position:0% +you think about like right if we did + + + align:start position:0% +you think about like right if we did +Coro with linear demand like Coro with + + align:start position:0% +Coro with linear demand like Coro with + + + align:start position:0% +Coro with linear demand like Coro with +linear demand you were getting like uh P + + align:start position:0% +linear demand you were getting like uh P + + + align:start position:0% +linear demand you were getting like uh P +star is approximately + + align:start position:0% +star is approximately + + + align:start position:0% +star is approximately +C+ one over or like simplest case um + + align:start position:0% +C+ one over or like simplest case um + + + align:start position:0% +C+ one over or like simplest case um +uh simplest case where Kuno was um uh n + + align:start position:0% +uh simplest case where Kuno was um uh n + + + align:start position:0% +uh simplest case where Kuno was um uh n +firms demand D ofp is one one over p and + + align:start position:0% +firms demand D ofp is one one over p and + + + align:start position:0% +firms demand D ofp is one one over p and +then I think in that model it was P star + + align:start position:0% +then I think in that model it was P star + + + align:start position:0% +then I think in that model it was P star +was equal to 1/ n + one and qar was + + align:start position:0% +was equal to 1/ n + one and qar was + + + align:start position:0% +was equal to 1/ n + one and qar was +equal to 1/ n + 1 so profits were like 1 + + align:start position:0% +equal to 1/ n + 1 so profits were like 1 + + + align:start position:0% +equal to 1/ n + 1 so profits were like 1 +over n^ + + align:start position:0% +over n^ + + + align:start position:0% +over n^ +SAR right so in Corno no profits + + align:start position:0% +SAR right so in Corno no profits + + + align:start position:0% +SAR right so in Corno no profits +approximately 1 over n s or 1 over n + + align:start position:0% +approximately 1 over n s or 1 over n + + + align:start position:0% +approximately 1 over n s or 1 over n +plus 1 squar whatever + + align:start position:0% +plus 1 squar whatever + + + align:start position:0% +plus 1 squar whatever +um you know another model I did was um + + align:start position:0% +um you know another model I did was um + + + align:start position:0% +um you know another model I did was um +uh model with search like in a model + + align:start position:0% +uh model with search like in a model + + + align:start position:0% +uh model with search like in a model +with search if you remember there was + + align:start position:0% +with search if you remember there was + + + align:start position:0% +with search if you remember there was +like the like the stall model you would + + align:start position:0% +like the like the stall model you would + + + align:start position:0% +like the like the stall model you would +always have the upper bound of the + + align:start position:0% +always have the upper bound of the + + + align:start position:0% +always have the upper bound of the +distribution always gave you the + + align:start position:0% +distribution always gave you the + + + align:start position:0% +distribution always gave you the +Monopoly profits uh as long as the + + align:start position:0% +Monopoly profits uh as long as the + + + align:start position:0% +Monopoly profits uh as long as the +search cost were an appropriate range uh + + align:start position:0% +search cost were an appropriate range uh + + + align:start position:0% +search cost were an appropriate range uh +and so that one you know declines + + align:start position:0% +and so that one you know declines + + + align:start position:0% +and so that one you know declines +something it's if you think about that + + align:start position:0% +something it's if you think about that + + + align:start position:0% +something it's if you think about that +that means it sort of declines + + align:start position:0% +that means it sort of declines + + + align:start position:0% +that means it sort of declines +slower because you know the firms are + + align:start position:0% +slower because you know the firms are + + + align:start position:0% +slower because you know the firms are +serving the nonshoppers + + align:start position:0% +serving the nonshoppers + + + align:start position:0% +serving the nonshoppers +uh so in the search model you're serving + + align:start position:0% +uh so in the search model you're serving + + + align:start position:0% +uh so in the search model you're serving +the non-shoppers you're always + + align:start position:0% +the non-shoppers you're always + + + align:start position:0% +the non-shoppers you're always +indifferent to charging the Monopoly + + align:start position:0% +indifferent to charging the Monopoly + + + align:start position:0% +indifferent to charging the Monopoly +price and so you get the Monopoly price + + align:start position:0% +price and so you get the Monopoly price + + + align:start position:0% +price and so you get the Monopoly price +divided by n plus divided by n you know + + align:start position:0% +divided by n plus divided by n you know + + + align:start position:0% +divided by n plus divided by n you know +times 1 minus mu is the profit so they + + align:start position:0% +times 1 minus mu is the profit so they + + + align:start position:0% +times 1 minus mu is the profit so they +go down like one over + + align:start position:0% +go down like one over + + + align:start position:0% +go down like one over +n um but whatever you have you know + + align:start position:0% +n um but whatever you have you know + + + align:start position:0% +n um but whatever you have you know +what's going to happen in this model in + + align:start position:0% +what's going to happen in this model in + + + align:start position:0% +what's going to happen in this model in +the first stage so if you have some + + align:start position:0% +the first stage so if you have some + + + align:start position:0% +the first stage so if you have some +level of fix let me sort of focus on + + align:start position:0% +level of fix let me sort of focus on + + + align:start position:0% +level of fix let me sort of focus on +Corno um let's suppose you do Corno and + + align:start position:0% +Corno um let's suppose you do Corno and + + + align:start position:0% +Corno um let's suppose you do Corno and +you have some fixed uh level of Entry + + align:start position:0% +you have some fixed uh level of Entry + + + align:start position:0% +you have some fixed uh level of Entry +cost k then in equilibrium you're going + + align:start position:0% +cost k then in equilibrium you're going + + + align:start position:0% +cost k then in equilibrium you're going +to have exactly two firms enter Because + + align:start position:0% +to have exactly two firms enter Because + + + align:start position:0% +to have exactly two firms enter Because +when two firms enter the firm's profits + + align:start position:0% +when two firms enter the firm's profits + + + align:start position:0% +when two firms enter the firm's profits +are above K if you had three firms in + + align:start position:0% +are above K if you had three firms in + + + align:start position:0% +are above K if you had three firms in +the market the profits would be below K + + align:start position:0% +the market the profits would be below K + + + align:start position:0% +the market the profits would be below K +so n equals 2 and so you know the number + + align:start position:0% +so n equals 2 and so you know the number + + + align:start position:0% +so n equals 2 and so you know the number +of firms it's it's locally invariant to + + align:start position:0% +of firms it's it's locally invariant to + + + align:start position:0% +of firms it's it's locally invariant to +K you know because you can sort of raise + + align:start position:0% +K you know because you can sort of raise + + + align:start position:0% +K you know because you can sort of raise +or lower costs and it doesn't effect + + align:start position:0% +or lower costs and it doesn't effect + + + align:start position:0% +or lower costs and it doesn't effect +things obviously if K drops then the + + align:start position:0% +things obviously if K drops then the + + + align:start position:0% +things obviously if K drops then the +third firm + + align:start position:0% +third firm + + + align:start position:0% +third firm +enters a ter piece of talk + + align:start position:0% +enters a ter piece of talk + + + align:start position:0% +enters a ter piece of talk +um okay um you could also think of a + + align:start position:0% +um okay um you could also think of a + + + align:start position:0% +um okay um you could also think of a +mixed strategy equilibrium solution like + + align:start position:0% +mixed strategy equilibrium solution like + + + align:start position:0% +mixed strategy equilibrium solution like +if if there's some large but finite + + align:start position:0% +if if there's some large but finite + + + align:start position:0% +if if there's some large but finite +number you know if there's some number + + align:start position:0% +number you know if there's some number + + + align:start position:0% +number you know if there's some number +of M of potential + + align:start position:0% + + + + align:start position:0% + +entrance uh where you know m is much + + align:start position:0% +entrance uh where you know m is much + + + align:start position:0% +entrance uh where you know m is much +bigger than n star you could also think + + align:start position:0% +bigger than n star you could also think + + + align:start position:0% +bigger than n star you could also think +of sort of M firms each mixing in or out + + align:start position:0% +of sort of M firms each mixing in or out + + + align:start position:0% +of sort of M firms each mixing in or out +uh and then you get a mixed strategy + + align:start position:0% +uh and then you get a mixed strategy + + + align:start position:0% +uh and then you get a mixed strategy +equilibrium in the mixed strategy + + align:start position:0% +equilibrium in the mixed strategy + + + align:start position:0% +equilibrium in the mixed strategy +equilibrium all the firms that are + + align:start position:0% +equilibrium all the firms that are + + + align:start position:0% +equilibrium all the firms that are +mixing are going to have to have + + align:start position:0% +mixing are going to have to have + + + align:start position:0% +mixing are going to have to have +expected profits exactly equal to K and + + align:start position:0% +expected profits exactly equal to K and + + + align:start position:0% +expected profits exactly equal to K and +so in that model all the firms that are + + align:start position:0% +so in that model all the firms that are + + + align:start position:0% +so in that model all the firms that are +mixing have expected profits exactly + + align:start position:0% +mixing have expected profits exactly + + + align:start position:0% +mixing have expected profits exactly +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +k um therefore you know here you can + + align:start position:0% +k um therefore you know here you can + + + align:start position:0% +k um therefore you know here you can +think of it as you're know you're going + + align:start position:0% +think of it as you're know you're going + + + align:start position:0% +think of it as you're know you're going +to expect to get two plus firms between + + align:start position:0% +to expect to get two plus firms between + + + align:start position:0% +to expect to get two plus firms between +two and three firms in the market but if + + align:start position:0% +two and three firms in the market but if + + + align:start position:0% +two and three firms in the market but if +it's obviously if it's like you know + + align:start position:0% +it's obviously if it's like you know + + + align:start position:0% +it's obviously if it's like you know +plus on draws sometimes you'll get one + + align:start position:0% +plus on draws sometimes you'll get one + + + align:start position:0% +plus on draws sometimes you'll get one +two three four five or more um you know + + align:start position:0% +two three four five or more um you know + + + align:start position:0% +two three four five or more um you know +in models like a procurement auction + + align:start position:0% +in models like a procurement auction + + + align:start position:0% +in models like a procurement auction +where there's one date on which everyone + + align:start position:0% +where there's one date on which everyone + + + align:start position:0% +where there's one date on which everyone +has to submit sealed bids and no one + + align:start position:0% +has to submit sealed bids and no one + + + align:start position:0% +has to submit sealed bids and no one +knows how many other biders there are + + align:start position:0% +knows how many other biders there are + + + align:start position:0% +knows how many other biders there are +the sort of expected you know Pi of n + + align:start position:0% +the sort of expected you know Pi of n + + + align:start position:0% +the sort of expected you know Pi of n +equals K is probably the right approach + + align:start position:0% +equals K is probably the right approach + + + align:start position:0% +equals K is probably the right approach +if you have models like you know the + + align:start position:0% +if you have models like you know the + + + align:start position:0% +if you have models like you know the +steel plants where the firms are not + + align:start position:0% +steel plants where the firms are not + + + align:start position:0% +steel plants where the firms are not +entering simultaneously they're entering + + align:start position:0% +entering simultaneously they're entering + + + align:start position:0% +entering simultaneously they're entering +sequentially then it's probably like the + + align:start position:0% +sequentially then it's probably like the + + + align:start position:0% +sequentially then it's probably like the +pure strategy equilibrium is the one you + + align:start position:0% +pure strategy equilibrium is the one you + + + align:start position:0% +pure strategy equilibrium is the one you +want to focus on because you know no + + align:start position:0% +want to focus on because you know no + + + align:start position:0% +want to focus on because you know no +one's going to open a third Steel plant + + align:start position:0% +one's going to open a third Steel plant + + + align:start position:0% +one's going to open a third Steel plant +if the third steel plant's going to + + align:start position:0% +if the third steel plant's going to + + + align:start position:0% +if the third steel plant's going to +drive prices below where you need to + + align:start position:0% +drive prices below where you need to + + + align:start position:0% +drive prices below where you need to +cover the fixed costs + + align:start position:0% +cover the fixed costs + + + align:start position:0% +cover the fixed costs +okay + + align:start position:0% + + + + align:start position:0% + +um so observations um you know fixed + + align:start position:0% +um so observations um you know fixed + + + align:start position:0% +um so observations um you know fixed +costs and competition determine the + + align:start position:0% +costs and competition determine the + + + align:start position:0% +costs and competition determine the +number of entries deter number of + + align:start position:0% +number of entries deter number of + + + align:start position:0% +number of entries deter number of +entrance but with lower fixed costs we + + align:start position:0% +entrance but with lower fixed costs we + + + align:start position:0% +entrance but with lower fixed costs we +get more + + align:start position:0% +get more + + + align:start position:0% +get more +entry uh in many models the number of + + align:start position:0% +entry uh in many models the number of + + + align:start position:0% +entry uh in many models the number of +firms goes to Infinity as the fixed + + align:start position:0% +firms goes to Infinity as the fixed + + + align:start position:0% +firms goes to Infinity as the fixed +costs of Entry go to zero the only time + + align:start position:0% +costs of Entry go to zero the only time + + + align:start position:0% +costs of Entry go to zero the only time +that's not going to happen is if you had + + align:start position:0% +that's not going to happen is if you had + + + align:start position:0% +that's not going to happen is if you had +you know I you know like I talked about + + align:start position:0% +you know I you know like I talked about + + + align:start position:0% +you know I you know like I talked about +the low at demand models where price + + align:start position:0% +the low at demand models where price + + + align:start position:0% +the low at demand models where price +asmp tootes to a positive um no it's + + align:start position:0% +asmp tootes to a positive um no it's + + + align:start position:0% +asmp tootes to a positive um no it's +still going to work um so where are you + + align:start position:0% +still going to work um so where are you + + + align:start position:0% +still going to work um so where are you +not going to get in Star + + align:start position:0% +not going to get in Star + + + align:start position:0% +not going to get in Star +um + + align:start position:0% +um + + + align:start position:0% +um +uh you know you're not going to get + + align:start position:0% +uh you know you're not going to get + + + align:start position:0% +uh you know you're not going to get +NSTAR goes to Infinity like in in Coro + + align:start position:0% +NSTAR goes to Infinity like in in Coro + + + align:start position:0% +NSTAR goes to Infinity like in in Coro +you don't get NSTAR goes to Infinity + + align:start position:0% +you don't get NSTAR goes to Infinity + + + align:start position:0% +you don't get NSTAR goes to Infinity +because in Coro in fact you get NSTAR is + + align:start position:0% +because in Coro in fact you get NSTAR is + + + align:start position:0% +because in Coro in fact you get NSTAR is +one so if profits hit zero at some point + + align:start position:0% +one so if profits hit zero at some point + + + align:start position:0% +one so if profits hit zero at some point +before when n gets large and even with + + align:start position:0% +before when n gets large and even with + + + align:start position:0% +before when n gets large and even with +like no entry costs you can still get or + + align:start position:0% +like no entry costs you can still get or + + + align:start position:0% +like no entry costs you can still get or +small POS of Entry C you can still get + + align:start position:0% +small POS of Entry C you can still get + + + align:start position:0% +small POS of Entry C you can still get +finite entry um you know profits are in + + align:start position:0% +finite entry um you know profits are in + + + align:start position:0% +finite entry um you know profits are in +this model are rounding error and we + + align:start position:0% +this model are rounding error and we + + + align:start position:0% +this model are rounding error and we +spent all this time working on markups + + align:start position:0% +spent all this time working on markups + + + align:start position:0% +spent all this time working on markups +but you know here the profits are just + + align:start position:0% +but you know here the profits are just + + + align:start position:0% +but you know here the profits are just +if this happens to be the fixed cost you + + align:start position:0% +if this happens to be the fixed cost you + + + align:start position:0% +if this happens to be the fixed cost you +get pretty big profits if this was the + + align:start position:0% +get pretty big profits if this was the + + + align:start position:0% +get pretty big profits if this was the +fixed cost you get very little profits + + align:start position:0% +fixed cost you get very little profits + + + align:start position:0% +fixed cost you get very little profits +if the fixed costs um you know drop to + + align:start position:0% +if the fixed costs um you know drop to + + + align:start position:0% +if the fixed costs um you know drop to +here you get even higher profits when + + align:start position:0% +here you get even higher profits when + + + align:start position:0% +here you get even higher profits when +they drop more you get + + align:start position:0% +they drop more you get + + + align:start position:0% +they drop more you get +hardly any profits at all so you know + + align:start position:0% +hardly any profits at all so you know + + + align:start position:0% +hardly any profits at all so you know +equilibrium profits that we + + align:start position:0% +equilibrium profits that we + + + align:start position:0% +equilibrium profits that we +observed really don't have to be related + + align:start position:0% +observed really don't have to be related + + + align:start position:0% +observed really don't have to be related +to anything we've talked about so far + + align:start position:0% +to anything we've talked about so far + + + align:start position:0% +to anything we've talked about so far +because all that matters is like how + + align:start position:0% +because all that matters is like how + + + align:start position:0% +because all that matters is like how +many firms fit in the market and then + + align:start position:0% +many firms fit in the market and then + + + align:start position:0% +many firms fit in the market and then +everything else just determines where + + align:start position:0% +everything else just determines where + + + align:start position:0% +everything else just determines where +you are in between the profits with two + + align:start position:0% +you are in between the profits with two + + + align:start position:0% +you are in between the profits with two +firms or three firms or three firms and + + align:start position:0% +firms or three firms or three firms and + + + align:start position:0% +firms or three firms or three firms and +four firms and so profits just become + + align:start position:0% +four firms and so profits just become + + + align:start position:0% +four firms and so profits just become +this rounding eror that's just + + align:start position:0% +this rounding eror that's just + + + align:start position:0% +this rounding eror that's just +Coincidence of where entry costs big + + align:start position:0% +Coincidence of where entry costs big + + + align:start position:0% +Coincidence of where entry costs big +enough that like the last firm just + + align:start position:0% +enough that like the last firm just + + + align:start position:0% +enough that like the last firm just +barely gets in now that's um you know + + align:start position:0% +barely gets in now that's um you know + + + align:start position:0% +barely gets in now that's um you know +that + + align:start position:0% +that + + + align:start position:0% +that +is equilibrium profits taking the fixed + + align:start position:0% +is equilibrium profits taking the fixed + + + align:start position:0% +is equilibrium profits taking the fixed +cost of entry into account you know it's + + align:start position:0% +cost of entry into account you know it's + + + align:start position:0% +cost of entry into account you know it's +still the case that the markups are + + align:start position:0% +still the case that the markups are + + + align:start position:0% +still the case that the markups are +higher when you have smaller numbers of + + align:start position:0% +higher when you have smaller numbers of + + + align:start position:0% +higher when you have smaller numbers of +firms the markups are higher but it's + + align:start position:0% +firms the markups are higher but it's + + + align:start position:0% +firms the markups are higher but it's +just the markups just offset the fixed + + align:start position:0% +just the markups just offset the fixed + + + align:start position:0% +just the markups just offset the fixed +cost the firms are + + align:start position:0% +cost the firms are + + + align:start position:0% +cost the firms are +incurring + + align:start position:0% +incurring + + + align:start position:0% +incurring +um in many models the equilibrium firm + + align:start position:0% +um in many models the equilibrium firm + + + align:start position:0% +um in many models the equilibrium firm +size increases when the market size + + align:start position:0% +size increases when the market size + + + align:start position:0% +size increases when the market size +increases so I I give the you know Coro + + align:start position:0% +increases so I I give the you know Coro + + + align:start position:0% +increases so I I give the you know Coro +example here you in the Coro example + + align:start position:0% +example here you in the Coro example + + + align:start position:0% +example here you in the Coro example +suppose you have + + align:start position:0% +suppose you have + + + align:start position:0% +suppose you have +Little M consumers in the market and so + + align:start position:0% +Little M consumers in the market and so + + + align:start position:0% +Little M consumers in the market and so +demand becomes M time D of + + align:start position:0% +demand becomes M time D of + + + align:start position:0% +demand becomes M time D of +P let's suppose we double the market + + align:start position:0% +P let's suppose we double the market + + + align:start position:0% +P let's suppose we double the market +size if you double the market size and + + align:start position:0% +size if you double the market size and + + + align:start position:0% +size if you double the market size and +you double the number of firms then the + + align:start position:0% +you double the number of firms then the + + + align:start position:0% +you double the number of firms then the +number of customers per firm would be + + align:start position:0% +number of customers per firm would be + + + align:start position:0% +number of customers per firm would be +the same but there's a second effect of + + align:start position:0% +the same but there's a second effect of + + + align:start position:0% +the same but there's a second effect of +the prices decreasing and so if the + + align:start position:0% +the prices decreasing and so if the + + + align:start position:0% +the prices decreasing and so if the +prices + + align:start position:0% +prices + + + align:start position:0% +prices +decrease um you know the prices decrease + + align:start position:0% +decrease um you know the prices decrease + + + align:start position:0% +decrease um you know the prices decrease +then the firms are worse off um so like + + align:start position:0% +then the firms are worse off um so like + + + align:start position:0% +then the firms are worse off um so like +you know in Coro in some sense it's like + + align:start position:0% +you know in Coro in some sense it's like + + + align:start position:0% +you know in Coro in some sense it's like +the price profits are going down like + + align:start position:0% +the price profits are going down like + + + align:start position:0% +the price profits are going down like +one N squared uh with n firms profits + + align:start position:0% +one N squared uh with n firms profits + + + align:start position:0% +one N squared uh with n firms profits +are going up proportional to M if there + + align:start position:0% +are going up proportional to M if there + + + align:start position:0% +are going up proportional to M if there +if the number of customers goes up so + + align:start position:0% +if the number of customers goes up so + + + align:start position:0% +if the number of customers goes up so +it's you're going to get like you know + + align:start position:0% +it's you're going to get like you know + + + align:start position:0% +it's you're going to get like you know +firm growth is going to be like square + + align:start position:0% +firm growth is going to be like square + + + align:start position:0% +firm growth is going to be like square +root of the number of customers so as + + align:start position:0% +root of the number of customers so as + + + align:start position:0% +root of the number of customers so as +the firm as the like Market increases + + align:start position:0% +the firm as the like Market increases + + + align:start position:0% +the firm as the like Market increases +firms go up like square root of the + + align:start position:0% +firms go up like square root of the + + + align:start position:0% +firms go up like square root of the +number of customers goes up so like firm + + align:start position:0% +number of customers goes up so like firm + + + align:start position:0% +number of customers goes up so like firm +size goes up like square root of the + + align:start position:0% +size goes up like square root of the + + + align:start position:0% +size goes up like square root of the +number of + + align:start position:0% + + + + align:start position:0% + +customers any questions on these simple + + align:start position:0% +customers any questions on these simple + + + align:start position:0% +customers any questions on these simple +observations + + align:start position:0% +observations + + + align:start position:0% +observations +okay um you know first substantial topic + + align:start position:0% +okay um you know first substantial topic + + + align:start position:0% +okay um you know first substantial topic +I want to talk about today is um what's + + align:start position:0% +I want to talk about today is um what's + + + align:start position:0% +I want to talk about today is um what's +the efficiency of Entry do we get more + + align:start position:0% +the efficiency of Entry do we get more + + + align:start position:0% +the efficiency of Entry do we get more +firms in markets than we want do we get + + align:start position:0% +firms in markets than we want do we get + + + align:start position:0% +firms in markets than we want do we get +fewer firms in markets than we want and + + align:start position:0% +fewer firms in markets than we want and + + + align:start position:0% +fewer firms in markets than we want and +and you know this is an important + + align:start position:0% +and you know this is an important + + + align:start position:0% +and you know this is an important +practical question you know there are + + align:start position:0% +practical question you know there are + + + align:start position:0% +practical question you know there are +many many Industries in many many + + align:start position:0% +many many Industries in many many + + + align:start position:0% +many many Industries in many many +countries where the firms have gotten + + align:start position:0% +countries where the firms have gotten + + + align:start position:0% +countries where the firms have gotten +together and have some kind of + + align:start position:0% +together and have some kind of + + + align:start position:0% +together and have some kind of +government sanctioned uh entry uh + + align:start position:0% +government sanctioned uh entry uh + + + align:start position:0% +government sanctioned uh entry uh +limitations you know right there's a + + align:start position:0% +limitations you know right there's a + + + align:start position:0% +limitations you know right there's a +question of the Massachusetts ballot + + align:start position:0% +question of the Massachusetts ballot + + + align:start position:0% +question of the Massachusetts ballot +about should um should liquor stores or + + align:start position:0% +about should um should liquor stores or + + + align:start position:0% +about should um should liquor stores or +should firms be able to sell beer in + + align:start position:0% +should firms be able to sell beer in + + + align:start position:0% +should firms be able to sell beer in +more than nine stores in the state of + + align:start position:0% +more than nine stores in the state of + + + align:start position:0% +more than nine stores in the state of +Massachusetts you know for for many + + align:start position:0% +Massachusetts you know for for many + + + align:start position:0% +Massachusetts you know for for many +years you only allowed to sell beer I + + align:start position:0% +years you only allowed to sell beer I + + + align:start position:0% +years you only allowed to sell beer I +think in one store in the state of + + align:start position:0% +think in one store in the state of + + + align:start position:0% +think in one store in the state of +Massachusetts so like all the + + align:start position:0% +Massachusetts so like all the + + + align:start position:0% +Massachusetts so like all the +supermarkets you notice I don't know if + + align:start position:0% +supermarkets you notice I don't know if + + + align:start position:0% +supermarkets you notice I don't know if +those you here you know like you notice + + align:start position:0% +those you here you know like you notice + + + align:start position:0% +those you here you know like you notice +you go to supermarkets in other states + + align:start position:0% +you go to supermarkets in other states + + + align:start position:0% +you go to supermarkets in other states +have beer um supermarkets in + + align:start position:0% +have beer um supermarkets in + + + align:start position:0% +have beer um supermarkets in +Massachusetts typically didn't have beer + + align:start position:0% +Massachusetts typically didn't have beer + + + align:start position:0% +Massachusetts typically didn't have beer +because there was a law that said you + + align:start position:0% +because there was a law that said you + + + align:start position:0% +because there was a law that said you +could only sell beer in one one of your + + align:start position:0% +could only sell beer in one one of your + + + align:start position:0% +could only sell beer in one one of your +stores in the entire state of + + align:start position:0% +stores in the entire state of + + + align:start position:0% +stores in the entire state of +Massachusetts and so you know Star + + align:start position:0% +Massachusetts and so you know Star + + + align:start position:0% +Massachusetts and so you know Star +Market could had to pick one Star Market + + align:start position:0% +Market could had to pick one Star Market + + + align:start position:0% +Market could had to pick one Star Market +to have beer you know now there are now + + align:start position:0% +to have beer you know now there are now + + + align:start position:0% +to have beer you know now there are now +you can sell beer in nine star markets + + align:start position:0% +you can sell beer in nine star markets + + + align:start position:0% +you can sell beer in nine star markets +and they're sort of thinking of + + align:start position:0% +and they're sort of thinking of + + + align:start position:0% +and they're sort of thinking of +increasing that level but you + + align:start position:0% +increasing that level but you + + + align:start position:0% +increasing that level but you +know why do we get these entry laws well + + align:start position:0% +know why do we get these entry laws well + + + align:start position:0% +know why do we get these entry laws well +the firms that are in the market always + + align:start position:0% +the firms that are in the market always + + + align:start position:0% +the firms that are in the market always +argue that you know competi entry is + + align:start position:0% +argue that you know competi entry is + + + align:start position:0% +argue that you know competi entry is +wasteful and we need to save the mom and + + align:start position:0% +wasteful and we need to save the mom and + + + align:start position:0% +wasteful and we need to save the mom and +pop stores and the small businesses and + + align:start position:0% +pop stores and the small businesses and + + + align:start position:0% +pop stores and the small businesses and +protect them from quote excessive entry + + align:start position:0% +protect them from quote excessive entry + + + align:start position:0% +protect them from quote excessive entry +so anyway here's a discussion of do we + + align:start position:0% +so anyway here's a discussion of do we + + + align:start position:0% +so anyway here's a discussion of do we +think entry should or shouldn't would or + + align:start position:0% +think entry should or shouldn't would or + + + align:start position:0% +think entry should or shouldn't would or +would not be excessive in markets um + + align:start position:0% +would not be excessive in markets um + + + align:start position:0% +would not be excessive in markets um +what's the first best here I'm going to + + align:start position:0% +what's the first best here I'm going to + + + align:start position:0% +what's the first best here I'm going to +do the homogeneous case first you know + + align:start position:0% +do the homogeneous case first you know + + + align:start position:0% +do the homogeneous case first you know +homogeneous Goods there's no + + align:start position:0% +homogeneous Goods there's no + + + align:start position:0% +homogeneous Goods there's no +idiosyncratic preferences the first best + + align:start position:0% +idiosyncratic preferences the first best + + + align:start position:0% +idiosyncratic preferences the first best +is just one firm have that one firm + + align:start position:0% +is just one firm have that one firm + + + align:start position:0% +is just one firm have that one firm +price at marginal cost um that's + + align:start position:0% +price at marginal cost um that's + + + align:start position:0% +price at marginal cost um that's +typically not feasible because You' need + + align:start position:0% +typically not feasible because You' need + + + align:start position:0% +typically not feasible because You' need +price regulation to force the monopolis + + align:start position:0% +price regulation to force the monopolis + + + align:start position:0% +price regulation to force the monopolis +price at marginal cost so what we often + + align:start position:0% +price at marginal cost so what we often + + + align:start position:0% +price at marginal cost so what we often +compare it to is this second best where + + align:start position:0% +compare it to is this second best where + + + align:start position:0% +compare it to is this second best where +the second best you take P star of n as + + align:start position:0% +the second best you take P star of n as + + + align:start position:0% +the second best you take P star of n as +given you can't affect the nature of the + + align:start position:0% +given you can't affect the nature of the + + + align:start position:0% +given you can't affect the nature of the +competition and you just sort of say + + align:start position:0% +competition and you just sort of say + + + align:start position:0% +competition and you just sort of say +what would be the optimal number of + + align:start position:0% +what would be the optimal number of + + + align:start position:0% +what would be the optimal number of +firms and + + align:start position:0% +firms and + + + align:start position:0% +firms and +given that you know P star of ends can + + align:start position:0% +given that you know P star of ends can + + + align:start position:0% +given that you know P star of ends can +be determined in equilibrium and so this + + align:start position:0% +be determined in equilibrium and so this + + + align:start position:0% +be determined in equilibrium and so this +would be our welfare + + align:start position:0% +would be our welfare + + + align:start position:0% +would be our welfare +calculation uh the welfare with n + + align:start position:0% +calculation uh the welfare with n + + + align:start position:0% +calculation uh the welfare with n +firms it's equal to the + + align:start position:0% +firms it's equal to the + + + align:start position:0% +firms it's equal to the +integral 0 to n we do big or little Q + + align:start position:0% +integral 0 to n we do big or little Q + + + align:start position:0% +integral 0 to n we do big or little Q +little Q + + align:start position:0% + + + + align:start position:0% + +okay so if you have n firms this is the + + align:start position:0% +okay so if you have n firms this is the + + + align:start position:0% +okay so if you have n firms this is the +gross Surplus produced by um firms + + align:start position:0% +gross Surplus produced by um firms + + + align:start position:0% +gross Surplus produced by um firms +producing total quantity n qar of + + align:start position:0% +producing total quantity n qar of + + + align:start position:0% +producing total quantity n qar of +n um this is the total production cost + + align:start position:0% +n um this is the total production cost + + + align:start position:0% +n um this is the total production cost +incurred when each of n firms produces + + align:start position:0% +incurred when each of n firms produces + + + align:start position:0% +incurred when each of n firms produces +quantity qar of N and these are the + + align:start position:0% +quantity qar of N and these are the + + + align:start position:0% +quantity qar of N and these are the +fixed costs okay so we want to maximize + + align:start position:0% +fixed costs okay so we want to maximize + + + align:start position:0% +fixed costs okay so we want to maximize +that um so the first theorem is that in + + align:start position:0% +that um so the first theorem is that in + + + align:start position:0% +that um so the first theorem is that in +this model with homogeneous Goods entry + + align:start position:0% +this model with homogeneous Goods entry + + + align:start position:0% +this model with homogeneous Goods entry +is always accessible so we do get too + + align:start position:0% +is always accessible so we do get too + + + align:start position:0% +is always accessible so we do get too +many firms in markets and we would like + + align:start position:0% +many firms in markets and we would like + + + align:start position:0% +many firms in markets and we would like +to restrict it why and here's a theorem + + align:start position:0% +to restrict it why and here's a theorem + + + align:start position:0% +to restrict it why and here's a theorem +um + + align:start position:0% +um + + + align:start position:0% +um +so you know suppos that this welfare + + align:start position:0% +so you know suppos that this welfare + + + align:start position:0% +so you know suppos that this welfare +function is concave I know I've talked + + align:start position:0% +function is concave I know I've talked + + + align:start position:0% +function is concave I know I've talked +about how things are often not concave + + align:start position:0% +about how things are often not concave + + + align:start position:0% +about how things are often not concave +welfare functions here would be concave + + align:start position:0% +welfare functions here would be concave + + + align:start position:0% +welfare functions here would be concave +because as you get you know as you get + + align:start position:0% +because as you get you know as you get + + + align:start position:0% +because as you get you know as you get +lots of firms you just ASM toote to line + + align:start position:0% +lots of firms you just ASM toote to line + + + align:start position:0% +lots of firms you just ASM toote to line +of slope K just it's in inefficient to + + align:start position:0% +of slope K just it's in inefficient to + + + align:start position:0% +of slope K just it's in inefficient to +keep paying these fixed entry costs over + + align:start position:0% +keep paying these fixed entry costs over + + + align:start position:0% +keep paying these fixed entry costs over +and over and over again um so suppose + + align:start position:0% +and over and over again um so suppose + + + align:start position:0% +and over and over again um so suppose +the welfare function is concave suppose + + align:start position:0% +the welfare function is concave suppose + + + align:start position:0% +the welfare function is concave suppose +the variable profits are decreasing in + + align:start position:0% +the variable profits are decreasing in + + + align:start position:0% +the variable profits are decreasing in +number of firms + + align:start position:0% +number of firms + + + align:start position:0% +number of firms +n and suppose that the equilibrium price + + align:start position:0% +n and suppose that the equilibrium price + + + align:start position:0% +n and suppose that the equilibrium price +and per firm quantities can be extended + + align:start position:0% +and per firm quantities can be extended + + + align:start position:0% +and per firm quantities can be extended +to differentiable functions that have + + align:start position:0% +to differentiable functions that have + + + align:start position:0% +to differentiable functions that have +these natural properties uh as the + + align:start position:0% +these natural properties uh as the + + + align:start position:0% +these natural properties uh as the +number of firms increases total output + + align:start position:0% +number of firms increases total output + + + align:start position:0% +number of firms increases total output +goes + + align:start position:0% +goes + + + align:start position:0% +goes +up uh as the number of firms goes up + + align:start position:0% +up uh as the number of firms goes up + + + align:start position:0% +up uh as the number of firms goes up +each individual firm's output goes + + align:start position:0% +each individual firm's output goes + + + align:start position:0% +each individual firm's output goes +down and at the equilibrium number of + + align:start position:0% +down and at the equilibrium number of + + + align:start position:0% +down and at the equilibrium number of +firms um uh price minus marginal cost is + + align:start position:0% +firms um uh price minus marginal cost is + + + align:start position:0% +firms um uh price minus marginal cost is +positive which it always should be or + + align:start position:0% +positive which it always should be or + + + align:start position:0% +positive which it always should be or +sorry this is given any number of firms + + align:start position:0% +sorry this is given any number of firms + + + align:start position:0% +sorry this is given any number of firms +given any number of firms n the + + align:start position:0% +given any number of firms n the + + + align:start position:0% +given any number of firms n the +resulting price would be above marginal + + align:start position:0% +resulting price would be above marginal + + + align:start position:0% +resulting price would be above marginal +cost uh the theorem is that then n is at + + align:start position:0% +cost uh the theorem is that then n is at + + + align:start position:0% +cost uh the theorem is that then n is at +least n second best minus one so it's + + align:start position:0% +least n second best minus one so it's + + + align:start position:0% +least n second best minus one so it's +it's entry is excessive although it can + + align:start position:0% +it's entry is excessive although it can + + + align:start position:0% +it's entry is excessive although it can +due to rounding errors be one too few um + + align:start position:0% +due to rounding errors be one too few um + + + align:start position:0% +due to rounding errors be one too few um +Bertrand is a case where it's one too + + align:start position:0% +Bertrand is a case where it's one too + + + align:start position:0% +Bertrand is a case where it's one too +few sometimes you'd like two firms you + + align:start position:0% +few sometimes you'd like two firms you + + + align:start position:0% +few sometimes you'd like two firms you +only get one uh but the general result + + align:start position:0% +only get one uh but the general result + + + align:start position:0% +only get one uh but the general result +is that you you get too many firms and + + align:start position:0% +is that you you get too many firms and + + + align:start position:0% +is that you you get too many firms and +and other than this possible rounding + + align:start position:0% +and other than this possible rounding + + + align:start position:0% +and other than this possible rounding +error + + align:start position:0% +error + + + align:start position:0% +error +issue + + align:start position:0% +issue + + + align:start position:0% +issue +um so proof um so first you know we've + + align:start position:0% +um so proof um so first you know we've + + + align:start position:0% +um so proof um so first you know we've +got this welfare function right the + + align:start position:0% +got this welfare function right the + + + align:start position:0% +got this welfare function right the +welfare function is naturally described + + align:start position:0% +welfare function is naturally described + + + align:start position:0% +welfare function is naturally described +only at a set of integer + + align:start position:0% + + + + align:start position:0% + +points okay but you know in many of + + align:start position:0% +points okay but you know in many of + + + align:start position:0% +points okay but you know in many of +these models like Corno over there right + + align:start position:0% +these models like Corno over there right + + + align:start position:0% +these models like Corno over there right +you know you have like you know P star + + align:start position:0% +you know you have like you know P star + + + align:start position:0% +you know you have like you know P star +and + + align:start position:0% +and + + + align:start position:0% +and +P star of n = 1 n + 1 qar of + + align:start position:0% +P star of n = 1 n + 1 qar of + + + align:start position:0% +P star of n = 1 n + 1 qar of +n = 1 n + 1 so you can just naturally + + align:start position:0% +n = 1 n + 1 so you can just naturally + + + align:start position:0% +n = 1 n + 1 so you can just naturally +think treat this as a continuous + + align:start position:0% +think treat this as a continuous + + + align:start position:0% +think treat this as a continuous +function when n's a + + align:start position:0% +function when n's a + + + align:start position:0% +function when n's a +continuous variable like use a function + + align:start position:0% +continuous variable like use a function + + + align:start position:0% +continuous variable like use a function +qar of X = 1x + 1 and by doing that you + + align:start position:0% +qar of X = 1x + 1 and by doing that you + + + align:start position:0% +qar of X = 1x + 1 and by doing that you +sort of extend the welfare you just sort + + align:start position:0% +sort of extend the welfare you just sort + + + align:start position:0% +sort of extend the welfare you just sort +of draw a + + align:start position:0% +of draw a + + + align:start position:0% +of draw a +smooth curve through those welfare + + align:start position:0% + + + + align:start position:0% + +points um I'm going to let n hat second + + align:start position:0% +points um I'm going to let n hat second + + + align:start position:0% +points um I'm going to let n hat second +best be the solution to where this + + align:start position:0% +best be the solution to where this + + + align:start position:0% +best be the solution to where this +thing's first order condition is zero um + + align:start position:0% +thing's first order condition is zero um + + + align:start position:0% +thing's first order condition is zero um +so that would be right here + + align:start position:0% + + + + align:start position:0% + +so n hat second best so I Define n hat + + align:start position:0% +so n hat second best so I Define n hat + + + align:start position:0% +so n hat second best so I Define n hat +second best to be the maximizer of the + + align:start position:0% +second best to be the maximizer of the + + + align:start position:0% +second best to be the maximizer of the +smooth + + align:start position:0% +smooth + + + align:start position:0% +smooth +curve um you know the second best is + + align:start position:0% +curve um you know the second best is + + + align:start position:0% +curve um you know the second best is +always going to be either if you know W + + align:start position:0% +always going to be either if you know W + + + align:start position:0% +always going to be either if you know W +is a concave function it's either going + + align:start position:0% +is a concave function it's either going + + + align:start position:0% +is a concave function it's either going +to be this point or this point so the + + align:start position:0% +to be this point or this point so the + + + align:start position:0% +to be this point or this point so the +optimal number of firms is always at + + align:start position:0% +optimal number of firms is always at + + + align:start position:0% +optimal number of firms is always at +most and what you get optim number of + + align:start position:0% +most and what you get optim number of + + + align:start position:0% +most and what you get optim number of +First is always at most what you get by + + align:start position:0% +First is always at most what you get by + + + align:start position:0% +First is always at most what you get by +just rounding up this point n hat second + + align:start position:0% +just rounding up this point n hat second + + + align:start position:0% +just rounding up this point n hat second +best um so what is the first order + + align:start position:0% +best um so what is the first order + + + align:start position:0% +best um so what is the first order +condition defining n hat second best + + align:start position:0% +condition defining n hat second best + + + align:start position:0% +condition defining n hat second best +well it's just you know the first order + + align:start position:0% +well it's just you know the first order + + + align:start position:0% +well it's just you know the first order +condition is DW of + + align:start position:0% +condition is DW of + + + align:start position:0% +condition is DW of +n + + align:start position:0% +n + + + align:start position:0% +n +DN equals evaluated at n hat second best + + align:start position:0% +DN equals evaluated at n hat second best + + + align:start position:0% +DN equals evaluated at n hat second best +equals + + align:start position:0% +equals + + + align:start position:0% +equals +zero right that's what determines this + + align:start position:0% +zero right that's what determines this + + + align:start position:0% +zero right that's what determines this +point + + align:start position:0% +point + + + align:start position:0% +point +here um what does that derivative look + + align:start position:0% +here um what does that derivative look + + + align:start position:0% +here um what does that derivative look +like so I differentiate this expression + + align:start position:0% +like so I differentiate this expression + + + align:start position:0% +like so I differentiate this expression +with respect to n the first term only + + align:start position:0% +with respect to n the first term only + + + align:start position:0% +with respect to n the first term only +depends on N through the upper limit of + + align:start position:0% +depends on N through the upper limit of + + + align:start position:0% +depends on N through the upper limit of +integration um so the derivative of this + + align:start position:0% +integration um so the derivative of this + + + align:start position:0% +integration um so the derivative of this +with respect to n is just um the value + + align:start position:0% +with respect to n is just um the value + + + align:start position:0% +with respect to n is just um the value +of this evaluated at n qar of n p of NQ + + align:start position:0% +of this evaluated at n qar of n p of NQ + + + align:start position:0% +of this evaluated at n qar of n p of NQ +star of n times the amount by which the + + align:start position:0% +star of n times the amount by which the + + + align:start position:0% +star of n times the amount by which the +the upper limit moves when n changes so + + align:start position:0% +the upper limit moves when n changes so + + + align:start position:0% +the upper limit moves when n changes so +the derivative of this with respect to n + + align:start position:0% +the derivative of this with respect to n + + + align:start position:0% +the derivative of this with respect to n +is what I wrote down + + align:start position:0% + + + + align:start position:0% + +here okay the second effect of n on + + align:start position:0% +here okay the second effect of n on + + + align:start position:0% +here okay the second effect of n on +welfare is this term changes n c of qar + + align:start position:0% +welfare is this term changes n c of qar + + + align:start position:0% +welfare is this term changes n c of qar +of n so the derivative of that with + + align:start position:0% +of n so the derivative of that with + + + align:start position:0% +of n so the derivative of that with +respect to n is C of qar of n plus n c + + align:start position:0% +respect to n is C of qar of n plus n c + + + align:start position:0% +respect to n is C of qar of n plus n c +Prime at qar of n qar Prime at n + + align:start position:0% + + + + align:start position:0% + +so that's the derivative of the second + + align:start position:0% +so that's the derivative of the second + + + align:start position:0% +so that's the derivative of the second +term and then the derivative of the + + align:start position:0% +term and then the derivative of the + + + align:start position:0% +term and then the derivative of the +third term with respect to n is just + + align:start position:0% +third term with respect to n is just + + + align:start position:0% +third term with respect to n is just +K so I just differentiate this + + align:start position:0% +K so I just differentiate this + + + align:start position:0% +K so I just differentiate this +expression with respect to N I say that + + align:start position:0% +expression with respect to N I say that + + + align:start position:0% +expression with respect to N I say that +evaluated at n hat second best is going + + align:start position:0% +evaluated at n hat second best is going + + + align:start position:0% +evaluated at n hat second best is going +to be equal to + + align:start position:0% +to be equal to + + + align:start position:0% +to be equal to +zero and then I'm going to start + + align:start position:0% +zero and then I'm going to start + + + align:start position:0% +zero and then I'm going to start +grouping + + align:start position:0% +grouping + + + align:start position:0% +grouping +terms uh first term I pull together + + align:start position:0% +terms uh first term I pull together + + + align:start position:0% +terms uh first term I pull together +are um P * Q minus C of Q and so I'm + + align:start position:0% +are um P * Q minus C of Q and so I'm + + + align:start position:0% +are um P * Q minus C of Q and so I'm +going to take this term times this minus + + align:start position:0% +going to take this term times this minus + + + align:start position:0% +going to take this term times this minus +this and call that the variable profit + + align:start position:0% +this and call that the variable profit + + + align:start position:0% +this and call that the variable profit +so that's Pi V Star of + + align:start position:0% +so that's Pi V Star of + + + align:start position:0% +so that's Pi V Star of +n um what's left over everything that's + + align:start position:0% +n um what's left over everything that's + + + align:start position:0% +n um what's left over everything that's +left over has an N qar Prime of n well + + align:start position:0% +left over has an N qar Prime of n well + + + align:start position:0% +left over has an N qar Prime of n well +there are two terms left over this times + + align:start position:0% +there are two terms left over this times + + + align:start position:0% +there are two terms left over this times +this and this that have an N qar Prime + + align:start position:0% +this and this that have an N qar Prime + + + align:start position:0% +this and this that have an N qar Prime +at n and those become n qar Prime at n * + + align:start position:0% +at n and those become n qar Prime at n * + + + align:start position:0% +at n and those become n qar Prime at n * +price minus marginal + + align:start position:0% +price minus marginal + + + align:start position:0% +price minus marginal +cost and then the third thing that's + + align:start position:0% +cost and then the third thing that's + + + align:start position:0% +cost and then the third thing that's +left over is the K at the + + align:start position:0% + + + + align:start position:0% + +end and then under this assumption that + + align:start position:0% +end and then under this assumption that + + + align:start position:0% +end and then under this assumption that +I made that um uh price minus marginal + + align:start position:0% +I made that um uh price minus marginal + + + align:start position:0% +I made that um uh price minus marginal +cost is always positive at the + + align:start position:0% +cost is always positive at the + + + align:start position:0% +cost is always positive at the +equilibrium prices this is a positive + + align:start position:0% +equilibrium prices this is a positive + + + align:start position:0% +equilibrium prices this is a positive +number and so what that means is that + + align:start position:0% +number and so what that means is that + + + align:start position:0% +number and so what that means is that +um uh if you evaluate this at n hat + + align:start position:0% +um uh if you evaluate this at n hat + + + align:start position:0% +um uh if you evaluate this at n hat +second best I get um variable profit + + align:start position:0% +second best I get um variable profit + + + align:start position:0% +second best I get um variable profit +uh minus K plus this uh equals Zer is + + align:start position:0% +uh minus K plus this uh equals Zer is + + + align:start position:0% +uh minus K plus this uh equals Zer is +that tells me that the variable profit + + align:start position:0% +that tells me that the variable profit + + + align:start position:0% +that tells me that the variable profit +evaluated n second best minus K is + + align:start position:0% +evaluated n second best minus K is + + + align:start position:0% +evaluated n second best minus K is +strictly positive which means that One X + + align:start position:0% +strictly positive which means that One X + + + align:start position:0% +strictly positive which means that One X +you know at at n hat second + + align:start position:0% +you know at at n hat second + + + align:start position:0% +you know at at n hat second +best variable profit is is bigger than K + + align:start position:0% +best variable profit is is bigger than K + + + align:start position:0% +best variable profit is is bigger than K +so it means other firms would like to + + align:start position:0% +so it means other firms would like to + + + align:start position:0% +so it means other firms would like to +come in so you know if we had exactly + + align:start position:0% +come in so you know if we had exactly + + + align:start position:0% +come in so you know if we had exactly +this many firms not that this is an + + align:start position:0% +this many firms not that this is an + + + align:start position:0% +this many firms not that this is an +integer the next firm always wants to + + align:start position:0% +integer the next firm always wants to + + + align:start position:0% +integer the next firm always wants to +come in so that means the equilibrium + + align:start position:0% +come in so that means the equilibrium + + + align:start position:0% +come in so that means the equilibrium +entry + + align:start position:0% +entry + + + align:start position:0% +entry +uh equilibrium entry + + align:start position:0% +uh equilibrium entry + + + align:start position:0% +uh equilibrium entry +oops um so equilibrium entry is at least + + align:start position:0% +oops um so equilibrium entry is at least + + + align:start position:0% +oops um so equilibrium entry is at least +um + + align:start position:0% +um + + + align:start position:0% +um +here because at you know at this point + + align:start position:0% +here because at you know at this point + + + align:start position:0% +here because at you know at this point +we know a firm wants to come in at this + + align:start position:0% +we know a firm wants to come in at this + + + align:start position:0% +we know a firm wants to come in at this +point we don't know but if you're if + + align:start position:0% +point we don't know but if you're if + + + align:start position:0% +point we don't know but if you're if +you're less then you definitely want to + + align:start position:0% +you're less then you definitely want to + + + align:start position:0% +you're less then you definitely want to +come in because Pi V Star is a + + align:start position:0% +come in because Pi V Star is a + + + align:start position:0% +come in because Pi V Star is a +decreasing function so Pi V Star is + + align:start position:0% +decreasing function so Pi V Star is + + + align:start position:0% +decreasing function so Pi V Star is +bigger than k at this point so Pi V Star + + align:start position:0% +bigger than k at this point so Pi V Star + + + align:start position:0% +bigger than k at this point so Pi V Star +is also bigger than k at this point so n + + align:start position:0% +is also bigger than k at this point so n + + + align:start position:0% +is also bigger than k at this point so n +star you know is somewhere out + + align:start position:0% + + + + align:start position:0% + +here so Nar is at least what you get is + + align:start position:0% +here so Nar is at least what you get is + + + align:start position:0% +here so Nar is at least what you get is +at least here uh and what did I say I + + align:start position:0% +at least here uh and what did I say I + + + align:start position:0% +at least here uh and what did I say I +said that you know the first + + align:start position:0% +said that you know the first + + + align:start position:0% +said that you know the first +best um and second + + align:start position:0% +best um and second + + + align:start position:0% +best um and second +best is one of these so if n second best + + align:start position:0% +best is one of these so if n second best + + + align:start position:0% +best is one of these so if n second best +is either this point or this point the + + align:start position:0% +is either this point or this point the + + + align:start position:0% +is either this point or this point the +equilibrium number is somewhere this + + align:start position:0% +equilibrium number is somewhere this + + + align:start position:0% +equilibrium number is somewhere this +point or higher we're always getting too + + align:start position:0% +point or higher we're always getting too + + + align:start position:0% +point or higher we're always getting too +many firms + + align:start position:0% + + + + align:start position:0% + +in is that is that okay + + align:start position:0% +in is that is that okay + + + align:start position:0% +in is that is that okay +you know maybe I have the next page just + + align:start position:0% +you know maybe I have the next page just + + + align:start position:0% +you know maybe I have the next page just +sort of easier maybe simpler + + align:start position:0% +sort of easier maybe simpler + + + align:start position:0% +sort of easier maybe simpler +intuition you know in a homogeneous good + + align:start position:0% +intuition you know in a homogeneous good + + + align:start position:0% +intuition you know in a homogeneous good +model the only benefit that anyone gets + + align:start position:0% +model the only benefit that anyone gets + + + align:start position:0% +model the only benefit that anyone gets +from entry is that we reduce the dead + + align:start position:0% +from entry is that we reduce the dead + + + align:start position:0% +from entry is that we reduce the dead +weight loss we get quantity + + align:start position:0% +weight loss we get quantity + + + align:start position:0% +weight loss we get quantity +increases right so what are the total + + align:start position:0% +increases right so what are the total + + + align:start position:0% +increases right so what are the total +gross Surplus you know total consumer + + align:start position:0% +gross Surplus you know total consumer + + + align:start position:0% +gross Surplus you know total consumer +and and firm benefits from the extra + + align:start position:0% +and and firm benefits from the extra + + + align:start position:0% +and and firm benefits from the extra +entry it's just the extra quantity that + + align:start position:0% +entry it's just the extra quantity that + + + align:start position:0% +entry it's just the extra quantity that +gets produced times P star minus C where + + align:start position:0% +gets produced times P star minus C where + + + align:start position:0% +gets produced times P star minus C where +P star is like the equilibrium profit + + align:start position:0% +P star is like the equilibrium profit + + + align:start position:0% +P star is like the equilibrium profit +you get at the equilibrium number of + + align:start position:0% +you get at the equilibrium number of + + + align:start position:0% +you get at the equilibrium number of +firms so we LD in more firms the welfare + + align:start position:0% +firms so we LD in more firms the welfare + + + align:start position:0% +firms so we LD in more firms the welfare +benefit is just how much did quantity go + + align:start position:0% +benefit is just how much did quantity go + + + align:start position:0% +benefit is just how much did quantity go +up times P star minus C okay + + align:start position:0% +up times P star minus C okay + + + align:start position:0% +up times P star minus C okay +um what does the entering firm get the + + align:start position:0% +um what does the entering firm get the + + + align:start position:0% +um what does the entering firm get the +entering firm gets much more than this + + align:start position:0% +entering firm gets much more than this + + + align:start position:0% +entering firm gets much more than this +because it's not the entering firm is + + align:start position:0% +because it's not the entering firm is + + + align:start position:0% +because it's not the entering firm is +not just selling the amount by which + + align:start position:0% +not just selling the amount by which + + + align:start position:0% +not just selling the amount by which +quantity has gone up the entering firm + + align:start position:0% +quantity has gone up the entering firm + + + align:start position:0% +quantity has gone up the entering firm +is getting that Quant it's getting you + + align:start position:0% +is getting that Quant it's getting you + + + align:start position:0% +is getting that Quant it's getting you +know the extra quantity but it's also + + align:start position:0% +know the extra quantity but it's also + + + align:start position:0% +know the extra quantity but it's also +stealing some quantity away from all the + + align:start position:0% +stealing some quantity away from all the + + + align:start position:0% +stealing some quantity away from all the +other firms that were there before and + + align:start position:0% +other firms that were there before and + + + align:start position:0% +other firms that were there before and +so people call that the sort of business + + align:start position:0% +so people call that the sort of business + + + align:start position:0% +so people call that the sort of business +dealing effect that the amount by which + + align:start position:0% +dealing effect that the amount by which + + + align:start position:0% +dealing effect that the amount by which +quantity goes up which is the welfare + + align:start position:0% +quantity goes up which is the welfare + + + align:start position:0% +quantity goes up which is the welfare +gain is much smaller than the amount by + + align:start position:0% +gain is much smaller than the amount by + + + align:start position:0% +gain is much smaller than the amount by +which sales go up for the last firm that + + align:start position:0% +which sales go up for the last firm that + + + align:start position:0% +which sales go up for the last firm that +comes in so the last firm's profits you + + align:start position:0% +comes in so the last firm's profits you + + + align:start position:0% +comes in so the last firm's profits you +know the the social cost of it coming in + + align:start position:0% +know the the social cost of it coming in + + + align:start position:0% +know the the social cost of it coming in +is + + align:start position:0% +is + + + align:start position:0% +is +k um the social benefit of it coming in + + align:start position:0% +k um the social benefit of it coming in + + + align:start position:0% +k um the social benefit of it coming in +is like Delta Q * P minus C but its + + align:start position:0% +is like Delta Q * P minus C but its + + + align:start position:0% +is like Delta Q * P minus C but its +profits are much bigger than its + + align:start position:0% +profits are much bigger than its + + + align:start position:0% +profits are much bigger than its +variable profits are much bigger than + + align:start position:0% +variable profits are much bigger than + + + align:start position:0% +variable profits are much bigger than +Delta Q * P minus C because it's getting + + align:start position:0% +Delta Q * P minus C because it's getting + + + align:start position:0% +Delta Q * P minus C because it's getting +all the profits on all the other units + + align:start position:0% +all the profits on all the other units + + + align:start position:0% +all the profits on all the other units +it's taken away from other firms instead + + align:start position:0% +it's taken away from other firms instead + + + align:start position:0% +it's taken away from other firms instead +and so that's the business stealing + + align:start position:0% +and so that's the business stealing + + + align:start position:0% +and so that's the business stealing +effect and in this um homogeneous good + + align:start position:0% +effect and in this um homogeneous good + + + align:start position:0% +effect and in this um homogeneous good +model right that business dealing effect + + align:start position:0% +model right that business dealing effect + + + align:start position:0% +model right that business dealing effect +is positive therefore you get too much + + align:start position:0% +is positive therefore you get too much + + + align:start position:0% +is positive therefore you get too much +entry other than this possible rounding + + align:start position:0% +entry other than this possible rounding + + + align:start position:0% +entry other than this possible rounding +error question okay um you know as I + + align:start position:0% +error question okay um you know as I + + + align:start position:0% +error question okay um you know as I +said it's true up to a rounding error + + align:start position:0% +said it's true up to a rounding error + + + align:start position:0% +said it's true up to a rounding error +but if you do numerical examples you + + align:start position:0% +but if you do numerical examples you + + + align:start position:0% +but if you do numerical examples you +find that you often get many many more + + align:start position:0% +find that you often get many many more + + + align:start position:0% +find that you often get many many more +firms than the soci than than you want + + align:start position:0% +firms than the soci than than you want + + + align:start position:0% +firms than the soci than than you want +um socially uh and the reason is that + + align:start position:0% +um socially uh and the reason is that + + + align:start position:0% +um socially uh and the reason is that +you know it's not just some of the + + align:start position:0% +you know it's not just some of the + + + align:start position:0% +you know it's not just some of the +demand is is business dealing most of + + align:start position:0% +demand is is business dealing most of + + + align:start position:0% +demand is is business dealing most of +the demand is business dealing so like + + align:start position:0% +the demand is business dealing so like + + + align:start position:0% +the demand is business dealing so like +in this Kuno example D of p is 1 minus P + + align:start position:0% +in this Kuno example D of p is 1 minus P + + + align:start position:0% +in this Kuno example D of p is 1 minus P +qar of n is 1 over n + + + align:start position:0% +qar of n is 1 over n + + + + align:start position:0% +qar of n is 1 over n + +one so what do you get from adding an + + align:start position:0% +one so what do you get from adding an + + + align:start position:0% +one so what do you get from adding an +nth firm you know demand when you have n + + align:start position:0% +nth firm you know demand when you have n + + + align:start position:0% +nth firm you know demand when you have n +firms production goes up to n/ n plus 1 + + align:start position:0% +firms production goes up to n/ n plus 1 + + + align:start position:0% +firms production goes up to n/ n plus 1 +where it used to be n minus one over n + + align:start position:0% +where it used to be n minus one over n + + + align:start position:0% +where it used to be n minus one over n +and so that difference is 1/ n * n + + + align:start position:0% + + + + align:start position:0% + +1 the nth firm is producing 1/ n + one + + align:start position:0% +1 the nth firm is producing 1/ n + one + + + align:start position:0% +1 the nth firm is producing 1/ n + one +so like 1/n fraction of its output is + + align:start position:0% +so like 1/n fraction of its output is + + + align:start position:0% +so like 1/n fraction of its output is +actual added output n minus one over n + + align:start position:0% +actual added output n minus one over n + + + align:start position:0% +actual added output n minus one over n +of its output is business dealing output + + align:start position:0% +of its output is business dealing output + + + align:start position:0% +of its output is business dealing output +and so in some sense the incentive that + + align:start position:0% +and so in some sense the incentive that + + + align:start position:0% +and so in some sense the incentive that +it has to enter is n times too large + + align:start position:0% +it has to enter is n times too large + + + align:start position:0% +it has to enter is n times too large +because it's it's sort of treating one + + align:start position:0% +because it's it's sort of treating one + + + align:start position:0% +because it's it's sort of treating one +over n plus one as it's as the benefit + + align:start position:0% +over n plus one as it's as the benefit + + + align:start position:0% +over n plus one as it's as the benefit +it's getting whereas one over n times + + align:start position:0% +it's getting whereas one over n times + + + align:start position:0% +it's getting whereas one over n times +that is actually the social benefit that + + align:start position:0% +that is actually the social benefit that + + + align:start position:0% +that is actually the social benefit that +it's producing okay and so you know + + align:start position:0% +it's producing okay and so you know + + + align:start position:0% +it's producing okay and so you know +because you know private benefit is n + + align:start position:0% +because you know private benefit is n + + + align:start position:0% +because you know private benefit is n +times the social benefit when private + + align:start position:0% +times the social benefit when private + + + align:start position:0% +times the social benefit when private +benefit is end times a social benefit + + align:start position:0% +benefit is end times a social benefit + + + align:start position:0% +benefit is end times a social benefit +you can get way way too many firms into + + align:start position:0% +you can get way way too many firms into + + + align:start position:0% +you can get way way too many firms into +the + + align:start position:0% +the + + + align:start position:0% +the +market + + align:start position:0% +market + + + align:start position:0% +market +okay okay so now let me think about you + + align:start position:0% +okay okay so now let me think about you + + + align:start position:0% +okay okay so now let me think about you +know that was entry when you have + + align:start position:0% +know that was entry when you have + + + align:start position:0% +know that was entry when you have +homogeneous Goods what happens when you + + align:start position:0% +homogeneous Goods what happens when you + + + align:start position:0% +homogeneous Goods what happens when you +get away from homog genous Goods when + + align:start position:0% +get away from homog genous Goods when + + + align:start position:0% +get away from homog genous Goods when +you get away from homogeneous Goods + + align:start position:0% +you get away from homogeneous Goods + + + align:start position:0% +you get away from homogeneous Goods +entry can be too high or too low okay + + align:start position:0% +entry can be too high or too low okay + + + align:start position:0% +entry can be too high or too low okay +and why is that well set General setup + + align:start position:0% +and why is that well set General setup + + + align:start position:0% +and why is that well set General setup +welfare when you have n firms it's going + + align:start position:0% +welfare when you have n firms it's going + + + align:start position:0% +welfare when you have n firms it's going +to be the sum of all the firms in the + + align:start position:0% +to be the sum of all the firms in the + + + align:start position:0% +to be the sum of all the firms in the +market of their variable + + align:start position:0% +market of their variable + + + align:start position:0% +market of their variable +profits plus the total consumer surplus + + align:start position:0% +profits plus the total consumer surplus + + + align:start position:0% +profits plus the total consumer surplus +in the market minus the fixed + + align:start position:0% + + + + align:start position:0% + +costs if I add an N plus first firm um I + + align:start position:0% +costs if I add an N plus first firm um I + + + align:start position:0% +costs if I add an N plus first firm um I +get the sum Over N plus one firms + + align:start position:0% +get the sum Over N plus one firms + + + align:start position:0% +get the sum Over N plus one firms +instead of n firms of the variable + + align:start position:0% +instead of n firms of the variable + + + align:start position:0% +instead of n firms of the variable +profits I now get consumer surplus when + + align:start position:0% +profits I now get consumer surplus when + + + align:start position:0% +profits I now get consumer surplus when +you have n plus1 firms but I pay higher + + align:start position:0% +you have n plus1 firms but I pay higher + + + align:start position:0% +you have n plus1 firms but I pay higher +fixed + + align:start position:0% +fixed + + + align:start position:0% +fixed +costs so what's the change in welfare + + align:start position:0% +costs so what's the change in welfare + + + align:start position:0% +costs so what's the change in welfare +from the last + + align:start position:0% +from the last + + + align:start position:0% +from the last +entrant um first let me group together + + align:start position:0% +entrant um first let me group together + + + align:start position:0% +entrant um first let me group together +the firm that's here that wasn't in this + + align:start position:0% +the firm that's here that wasn't in this + + + align:start position:0% +the firm that's here that wasn't in this +sum the N firm n plus one I get the + + align:start position:0% +sum the N firm n plus one I get the + + + align:start position:0% +sum the N firm n plus one I get the +variable profit of firm n plus one minus + + align:start position:0% +variable profit of firm n plus one minus + + + align:start position:0% +variable profit of firm n plus one minus +its fixed cost that's a difference + + align:start position:0% +its fixed cost that's a difference + + + align:start position:0% +its fixed cost that's a difference +here and then I get two other terms the + + align:start position:0% +here and then I get two other terms the + + + align:start position:0% +here and then I get two other terms the +first is subtracting the corresponding + + align:start position:0% +first is subtracting the corresponding + + + align:start position:0% +first is subtracting the corresponding +I's here I get sum IAL 1 to n variable + + align:start position:0% +I's here I get sum IAL 1 to n variable + + + align:start position:0% +I's here I get sum IAL 1 to n variable +profits of firm I with n plus one versus + + align:start position:0% +profits of firm I with n plus one versus + + + align:start position:0% +profits of firm I with n plus one versus +n firms and then I get the consumer + + align:start position:0% +n firms and then I get the consumer + + + align:start position:0% +n firms and then I get the consumer +surplus with n plus one minus n + + align:start position:0% +surplus with n plus one minus n + + + align:start position:0% +surplus with n plus one minus n +firms + + align:start position:0% +firms + + + align:start position:0% +firms +um so when I when I wrote here entry is + + align:start position:0% +um so when I when I wrote here entry is + + + align:start position:0% +um so when I when I wrote here entry is +socially optimal I probably should have + + align:start position:0% +socially optimal I probably should have + + + align:start position:0% +socially optimal I probably should have +said entry of firm n plus one is + + align:start position:0% +said entry of firm n plus one is + + + align:start position:0% +said entry of firm n plus one is +socially optimal if this Delta W is + + align:start position:0% +socially optimal if this Delta W is + + + align:start position:0% +socially optimal if this Delta W is +positive um + + align:start position:0% +positive um + + + align:start position:0% +positive um +why might free entry you know so what we + + align:start position:0% +why might free entry you know so what we + + + align:start position:0% +why might free entry you know so what we +want is if this is positive we want firm + + align:start position:0% +want is if this is positive we want firm + + + align:start position:0% +want is if this is positive we want firm +n plus one to come in and if firm if + + align:start position:0% +n plus one to come in and if firm if + + + align:start position:0% +n plus one to come in and if firm if +Delta W was negative we don't want firm + + align:start position:0% +Delta W was negative we don't want firm + + + align:start position:0% +Delta W was negative we don't want firm +n plus one to come + + align:start position:0% +n plus one to come + + + align:start position:0% +n plus one to come +in okay so first of all why might entry + + align:start position:0% +in okay so first of all why might entry + + + align:start position:0% +in okay so first of all why might entry +be excessive so entry would be excessive + + align:start position:0% +be excessive so entry would be excessive + + + align:start position:0% +be excessive so entry would be excessive +if this was positive but this was + + align:start position:0% +if this was positive but this was + + + align:start position:0% +if this was positive but this was +negative why could this be positive and + + align:start position:0% +negative why could this be positive and + + + align:start position:0% +negative why could this be positive and +this be negative well you know if this + + align:start position:0% +this be negative well you know if this + + + align:start position:0% +this be negative well you know if this +is positive to make a but small to make + + align:start position:0% +is positive to make a but small to make + + + align:start position:0% +is positive to make a but small to make +a firm want to come in + + align:start position:0% +a firm want to come in + + + align:start position:0% +a firm want to come in +but this is a big negative number and + + align:start position:0% +but this is a big negative number and + + + align:start position:0% +but this is a big negative number and +why could this be a big negative number + + align:start position:0% +why could this be a big negative number + + + align:start position:0% +why could this be a big negative number +you know this is how every other firm's + + align:start position:0% +you know this is how every other firm's + + + align:start position:0% +you know this is how every other firm's +profits are affected by me coming in if + + align:start position:0% +profits are affected by me coming in if + + + align:start position:0% +profits are affected by me coming in if +I drive down prices and I take quantity + + align:start position:0% +I drive down prices and I take quantity + + + align:start position:0% +I drive down prices and I take quantity +away from the other firms you know they + + align:start position:0% +away from the other firms you know they + + + align:start position:0% +away from the other firms you know they +suffer both because the profits they + + align:start position:0% +suffer both because the profits they + + + align:start position:0% +suffer both because the profits they +earn on the units they still sell go + + align:start position:0% +earn on the units they still sell go + + + align:start position:0% +earn on the units they still sell go +down and because that they don't sell + + align:start position:0% +down and because that they don't sell + + + align:start position:0% +down and because that they don't sell +some units and they don't own P star + + align:start position:0% +some units and they don't own P star + + + align:start position:0% +some units and they don't own P star +minus C so this is what we call again + + align:start position:0% +minus C so this is what we call again + + + align:start position:0% +minus C so this is what we call again +this is the business stealing effect if + + align:start position:0% +this is the business stealing effect if + + + align:start position:0% +this is the business stealing effect if +this business stealing number is NE is + + align:start position:0% +this business stealing number is NE is + + + align:start position:0% +this business stealing number is NE is +is always negative if it's a big + + align:start position:0% +is always negative if it's a big + + + align:start position:0% +is always negative if it's a big +negative number and this is a small + + align:start position:0% +negative number and this is a small + + + align:start position:0% +negative number and this is a small +positive number we can get the entrant + + align:start position:0% +positive number we can get the entrant + + + align:start position:0% +positive number we can get the entrant +coming in even though this business + + align:start position:0% +coming in even though this business + + + align:start position:0% +coming in even though this business +stealing term is + + align:start position:0% + + + + align:start position:0% + +negative um but then you know the second + + align:start position:0% +negative um but then you know the second + + + align:start position:0% +negative um but then you know the second +effect is that we could have firm n + + align:start position:0% +effect is that we could have firm n + + + align:start position:0% +effect is that we could have firm n +doesn't come in because this is + + align:start position:0% +doesn't come in because this is + + + align:start position:0% +doesn't come in because this is +negative uh and this is negative but + + align:start position:0% +negative uh and this is negative but + + + align:start position:0% +negative uh and this is negative but +Delta W is positive because there's a + + align:start position:0% +Delta W is positive because there's a + + + align:start position:0% +Delta W is positive because there's a +big increase in consumer surplus + + align:start position:0% + + + + align:start position:0% + +and you know I showed in the homogeneous + + align:start position:0% +and you know I showed in the homogeneous + + + align:start position:0% +and you know I showed in the homogeneous +good model this doesn't happen except + + align:start position:0% +good model this doesn't happen except + + + align:start position:0% +good model this doesn't happen except +with that ra into that rounding error + + align:start position:0% +with that ra into that rounding error + + + align:start position:0% +with that ra into that rounding error +effect but once you get to heterogeneous + + align:start position:0% +effect but once you get to heterogeneous + + + align:start position:0% +effect but once you get to heterogeneous +Goods like it could be that when you get + + align:start position:0% +Goods like it could be that when you get + + + align:start position:0% +Goods like it could be that when you get +more Goods in the market consumer + + align:start position:0% +more Goods in the market consumer + + + align:start position:0% +more Goods in the market consumer +surplus goes up by more than prices go + + align:start position:0% +surplus goes up by more than prices go + + + align:start position:0% +surplus goes up by more than prices go +down because consumers get a good that's + + align:start position:0% +down because consumers get a good that's + + + align:start position:0% +down because consumers get a good that's +better matched to their tastes and + + align:start position:0% +better matched to their tastes and + + + align:start position:0% +better matched to their tastes and +because the good new good is better + + align:start position:0% +because the good new good is better + + + align:start position:0% +because the good new good is better +matched to their tastes there's a big + + align:start position:0% +matched to their tastes there's a big + + + align:start position:0% +matched to their tastes there's a big +increase in consumer surplus that isn't + + align:start position:0% +increase in consumer surplus that isn't + + + align:start position:0% +increase in consumer surplus that isn't +just the loss and profits and so if the + + align:start position:0% +just the loss and profits and so if the + + + align:start position:0% +just the loss and profits and so if the +increase in consumer surplus is coming + + align:start position:0% +increase in consumer surplus is coming + + + align:start position:0% +increase in consumer surplus is coming +from other channels like match quality + + align:start position:0% +from other channels like match quality + + + align:start position:0% +from other channels like match quality +rather than just from prices going down + + align:start position:0% +rather than just from prices going down + + + align:start position:0% +rather than just from prices going down +then this term can outweigh the business + + align:start position:0% +then this term can outweigh the business + + + align:start position:0% +then this term can outweigh the business +dealing effect and you could have too + + align:start position:0% +dealing effect and you could have too + + + align:start position:0% +dealing effect and you could have too +few firms in a market okay because firms + + align:start position:0% +few firms in a market okay because firms + + + align:start position:0% +few firms in a market okay because firms +just firms don't inter you know like I + + align:start position:0% +just firms don't inter you know like I + + + align:start position:0% +just firms don't inter you know like I +mean firms not internalizing cons + + align:start position:0% +mean firms not internalizing cons + + + align:start position:0% +mean firms not internalizing cons +consumer surplus is why you get too few + + align:start position:0% +consumer surplus is why you get too few + + + align:start position:0% +consumer surplus is why you get too few +firms in the Bertrand model in the + + align:start position:0% +firms in the Bertrand model in the + + + align:start position:0% +firms in the Bertrand model in the +Bertrand model firms don't realize I + + align:start position:0% +Bertrand model firms don't realize I + + + align:start position:0% +Bertrand model firms don't realize I +come in yes I lose some money but all + + align:start position:0% +come in yes I lose some money but all + + + align:start position:0% +come in yes I lose some money but all +those consumers are way better off um + + align:start position:0% +those consumers are way better off um + + + align:start position:0% +those consumers are way better off um +because the consumer the price drops so + + align:start position:0% +because the consumer the price drops so + + + align:start position:0% +because the consumer the price drops so +much uh but in another model it's the + + align:start position:0% +much uh but in another model it's the + + + align:start position:0% +much uh but in another model it's the +consumers don't realize the firms don't + + align:start position:0% +consumers don't realize the firms don't + + + align:start position:0% +consumers don't realize the firms don't +realize that like I come in I don't make + + align:start position:0% +realize that like I come in I don't make + + + align:start position:0% +realize that like I come in I don't make +that much money but consumers are so + + align:start position:0% +that much money but consumers are so + + + align:start position:0% +that much money but consumers are so +happy to have my product that that + + align:start position:0% +happy to have my product that that + + + align:start position:0% +happy to have my product that that +social welfare is + + align:start position:0% + + + + align:start position:0% + +better + + align:start position:0% +better + + + align:start position:0% +better +um okay any questions but so you know in + + align:start position:0% +um okay any questions but so you know in + + + align:start position:0% +um okay any questions but so you know in +a general model the most General + + align:start position:0% +a general model the most General + + + align:start position:0% +a general model the most General +conclusion is that entry can be too high + + align:start position:0% +conclusion is that entry can be too high + + + align:start position:0% +conclusion is that entry can be too high +or too low socially and it depends on + + align:start position:0% +or too low socially and it depends on + + + align:start position:0% +or too low socially and it depends on +just which of these effects is more + + align:start position:0% +just which of these effects is more + + + align:start position:0% +just which of these effects is more +important the social welfare effect or + + align:start position:0% +important the social welfare effect or + + + align:start position:0% +important the social welfare effect or +the business stealing effect um prices + + align:start position:0% +the business stealing effect um prices + + + align:start position:0% +the business stealing effect um prices +going down alone is not enough is not + + align:start position:0% +going down alone is not enough is not + + + align:start position:0% +going down alone is not enough is not +enough to do it you have got to have + + align:start position:0% +enough to do it you have got to have + + + align:start position:0% +enough to do it you have got to have +other channels of the consumer surplus + + align:start position:0% +other channels of the consumer surplus + + + align:start position:0% +other channels of the consumer surplus +going + + align:start position:0% +going + + + align:start position:0% +going +up okay + + align:start position:0% + + + + align:start position:0% + +um I just sort of figured I'd put in one + + align:start position:0% +um I just sort of figured I'd put in one + + + align:start position:0% +um I just sort of figured I'd put in one +slide of what happens if I actually + + align:start position:0% +slide of what happens if I actually + + + align:start position:0% +slide of what happens if I actually +compute these things I I would say that + + align:start position:0% +compute these things I I would say that + + + align:start position:0% +compute these things I I would say that +if you write down the most obvious + + align:start position:0% +if you write down the most obvious + + + align:start position:0% +if you write down the most obvious +models you're going to write down to try + + align:start position:0% +models you're going to write down to try + + + align:start position:0% +models you're going to write down to try +to compute these things while this + + align:start position:0% +to compute these things while this + + + align:start position:0% +to compute these things while this +consumer Surplus effect means that + + align:start position:0% +consumer Surplus effect means that + + + align:start position:0% +consumer Surplus effect means that +welfare can we can get too few firms + + align:start position:0% +welfare can we can get too few firms + + + align:start position:0% +welfare can we can get too few firms +most models you write down if you're not + + align:start position:0% +most models you write down if you're not + + + align:start position:0% +most models you write down if you're not +thinking about writing down something to + + align:start position:0% +thinking about writing down something to + + + align:start position:0% +thinking about writing down something to +get it to happen you're going to also + + align:start position:0% +get it to happen you're going to also + + + align:start position:0% +get it to happen you're going to also +conclude that there's still way too many + + align:start position:0% +conclude that there's still way too many + + + align:start position:0% +conclude that there's still way too many +firms in markets so I I do an example + + align:start position:0% +firms in markets so I I do an example + + + align:start position:0% +firms in markets so I I do an example +here so you know consider a hoteling + + align:start position:0% +here so you know consider a hoteling + + + align:start position:0% +here so you know consider a hoteling +like model where you have a mass m of + + align:start position:0% +like model where you have a mass m of + + + align:start position:0% +like model where you have a mass m of +consumers and can I write over here so + + align:start position:0% +consumers and can I write over here so + + + align:start position:0% +consumers and can I write over here so +let's think + + align:start position:0% +let's think + + + align:start position:0% +let's think +about uh hotelling Circle so this is a + + align:start position:0% +about uh hotelling Circle so this is a + + + align:start position:0% +about uh hotelling Circle so this is a +um ice cream stand locating around like + + align:start position:0% +um ice cream stand locating around like + + + align:start position:0% +um ice cream stand locating around like +a Hawaiian island that has just beaches + + align:start position:0% +a Hawaiian island that has just beaches + + + align:start position:0% +a Hawaiian island that has just beaches +around the entire perimeter and so if + + align:start position:0% +around the entire perimeter and so if + + + align:start position:0% +around the entire perimeter and so if +you get n + + align:start position:0% + + + + align:start position:0% + +firms you know they they suppose you get + + align:start position:0% +firms you know they they suppose you get + + + align:start position:0% +firms you know they they suppose you get +n firms they locate themselves evenly + + align:start position:0% +n firms they locate themselves evenly + + + align:start position:0% +n firms they locate themselves evenly +around the + + align:start position:0% +around the + + + align:start position:0% +around the +circle + + align:start position:0% + + + + align:start position:0% + +um you know in this C+ T model like + + align:start position:0% +um you know in this C+ T model like + + + align:start position:0% +um you know in this C+ T model like +let's if you have n firms the dis the + + align:start position:0% +let's if you have n firms the dis the + + + align:start position:0% +let's if you have n firms the dis the +transportation cost distance between + + align:start position:0% +transportation cost distance between + + + align:start position:0% +transportation cost distance between +here and here is only going to be T Over + + align:start position:0% +here and here is only going to be T Over + + + align:start position:0% +here and here is only going to be T Over +N when you have n firms and so if the if + + align:start position:0% +N when you have n firms and so if the if + + + align:start position:0% +N when you have n firms and so if the if +it's t to walk the whole perimeter of + + align:start position:0% +it's t to walk the whole perimeter of + + + align:start position:0% +it's t to walk the whole perimeter of +the island it's t Over N when you put n + + align:start position:0% +the island it's t Over N when you put n + + + align:start position:0% +the island it's t Over N when you put n +firms around the + + align:start position:0% +firms around the + + + align:start position:0% +firms around the +perimeter okay so if you get n firms + + align:start position:0% +perimeter okay so if you get n firms + + + align:start position:0% +perimeter okay so if you get n firms +that are arranged evenly what you + + align:start position:0% +that are arranged evenly what you + + + align:start position:0% +that are arranged evenly what you +basically get is you know each firm here + + align:start position:0% +basically get is you know each firm here + + + align:start position:0% +basically get is you know each firm here +is just competing with the firm on its + + align:start position:0% +is just competing with the firm on its + + + align:start position:0% +is just competing with the firm on its +right and the firm on its left I didn't + + align:start position:0% +right and the firm on its left I didn't + + + align:start position:0% +right and the firm on its left I didn't +draw those so evenly but let's assume + + align:start position:0% +draw those so evenly but let's assume + + + align:start position:0% +draw those so evenly but let's assume +this distance is T Over N this distance + + align:start position:0% +this distance is T Over N this distance + + + align:start position:0% +this distance is T Over N this distance +is T Over N so it's just like I'm + + align:start position:0% +is T Over N so it's just like I'm + + + align:start position:0% +is T Over N so it's just like I'm +playing two simultaneous hoteling games + + align:start position:0% +playing two simultaneous hoteling games + + + align:start position:0% +playing two simultaneous hoteling games +one against this firm one against this + + align:start position:0% +one against this firm one against this + + + align:start position:0% +one against this firm one against this +firm term so the equilibrium becomes P + + align:start position:0% +firm term so the equilibrium becomes P + + + align:start position:0% +firm term so the equilibrium becomes P +staral C + t + + align:start position:0% +staral C + t + + + align:start position:0% +staral C + t +n uh what's the variable profit uh if + + align:start position:0% +n uh what's the variable profit uh if + + + align:start position:0% +n uh what's the variable profit uh if +there are M consumers on the beach um I + + align:start position:0% +there are M consumers on the beach um I + + + align:start position:0% +there are M consumers on the beach um I +get a fraction one over n of them in + + align:start position:0% +get a fraction one over n of them in + + + align:start position:0% +get a fraction one over n of them in +equilibrium and my markup is T Over N + + align:start position:0% +equilibrium and my markup is T Over N + + + align:start position:0% +equilibrium and my markup is T Over N +so my profits are + + align:start position:0% +so my profits are + + + align:start position:0% +so my profits are +M uh T over + + align:start position:0% +M uh T over + + + align:start position:0% +M uh T over +n^2 I set that equal to K a and then it + + align:start position:0% +n^2 I set that equal to K a and then it + + + align:start position:0% +n^2 I set that equal to K a and then it +just becomes Nal < TK of M * t k so + + align:start position:0% +just becomes Nal < TK of M * t k so + + + align:start position:0% +just becomes Nal < TK of M * t k so +that's you know again as I said you know + + align:start position:0% +that's you know again as I said you know + + + align:start position:0% +that's you know again as I said you know +this is a again larger firms theorem + + align:start position:0% +this is a again larger firms theorem + + + align:start position:0% +this is a again larger firms theorem +that says as the market size goes up the + + align:start position:0% +that says as the market size goes up the + + + align:start position:0% +that says as the market size goes up the +number of firms goes up in this model + + align:start position:0% +number of firms goes up in this model + + + align:start position:0% +number of firms goes up in this model +also like the square root of the number + + align:start position:0% +also like the square root of the number + + + align:start position:0% +also like the square root of the number +of + + align:start position:0% + + + + align:start position:0% + +customers okay um what's the social + + align:start position:0% +customers okay um what's the social + + + align:start position:0% +customers okay um what's the social +welfare um they M + + align:start position:0% +welfare um they M + + + align:start position:0% +welfare um they M +consumers um + + align:start position:0% +consumers um + + + align:start position:0% +consumers um +you know so suppose we're in this model + + align:start position:0% +you know so suppose we're in this model + + + align:start position:0% +you know so suppose we're in this model +and these things are both T Over + + align:start position:0% +and these things are both T Over + + + align:start position:0% +and these things are both T Over +N social welfare is just total gross + + align:start position:0% +N social welfare is just total gross + + + align:start position:0% +N social welfare is just total gross +Surplus received minus costs of + + align:start position:0% +Surplus received minus costs of + + + align:start position:0% +Surplus received minus costs of +production minus average mismatch + + align:start position:0% +production minus average mismatch + + + align:start position:0% +production minus average mismatch +disutility or or Transportation cost + + align:start position:0% +disutility or or Transportation cost + + + align:start position:0% +disutility or or Transportation cost +disutility you know this guy here sells + + align:start position:0% +disutility you know this guy here sells + + + align:start position:0% +disutility you know this guy here sells +to customers who are within distance T + + align:start position:0% +to customers who are within distance T + + + align:start position:0% +to customers who are within distance T +over 2N to the left + + align:start position:0% +over 2N to the left + + + align:start position:0% +over 2N to the left +and customers within T over 2N to the + + align:start position:0% +and customers within T over 2N to the + + + align:start position:0% +and customers within T over 2N to the +right so he's selling to customers who + + align:start position:0% +right so he's selling to customers who + + + align:start position:0% +right so he's selling to customers who +are you know T Over N is his distance so + + align:start position:0% +are you know T Over N is his distance so + + + align:start position:0% +are you know T Over N is his distance so +everybody equid distant between him and + + align:start position:0% +everybody equid distant between him and + + + align:start position:0% +everybody equid distant between him and +the next firm over buys from him if you + + align:start position:0% +the next firm over buys from him if you + + + align:start position:0% +the next firm over buys from him if you +sell to customers whose distance ranges + + align:start position:0% +sell to customers whose distance ranges + + + align:start position:0% +sell to customers whose distance ranges +from0 to T over 2N the average distance + + align:start position:0% +from0 to T over 2N the average distance + + + align:start position:0% +from0 to T over 2N the average distance +of that people have to travel is T over + + align:start position:0% +of that people have to travel is T over + + + align:start position:0% +of that people have to travel is T over +4N so this is the extra welfare increase + + align:start position:0% +4N so this is the extra welfare increase + + + align:start position:0% +4N so this is the extra welfare increase +that I mentioned that as n increases the + + align:start position:0% +that I mentioned that as n increases the + + + align:start position:0% +that I mentioned that as n increases the +distance traveled goes down down that + + align:start position:0% +distance traveled goes down down that + + + align:start position:0% +distance traveled goes down down that +causes a consumer surplus increase + + align:start position:0% +causes a consumer surplus increase + + + align:start position:0% +causes a consumer surplus increase +that's separate from the one that comes + + align:start position:0% +that's separate from the one that comes + + + align:start position:0% +that's separate from the one that comes +from the price is dropping okay anyway + + align:start position:0% +from the price is dropping okay anyway + + + align:start position:0% +from the price is dropping okay anyway +so in this model total social welfare is + + align:start position:0% +so in this model total social welfare is + + + align:start position:0% +so in this model total social welfare is +M * V minus M * cus M * T 4N minus + + align:start position:0% +M * V minus M * cus M * T 4N minus + + + align:start position:0% +M * V minus M * cus M * T 4N minus +NK uh notice that M * V minus C is + + align:start position:0% +NK uh notice that M * V minus C is + + + align:start position:0% +NK uh notice that M * V minus C is +completely independent of n in in you + + align:start position:0% +completely independent of n in in you + + + align:start position:0% +completely independent of n in in you +know the hoteling model you know + + align:start position:0% +know the hoteling model you know + + + align:start position:0% +know the hoteling model you know +assuming V is large everybody buys all + + align:start position:0% +assuming V is large everybody buys all + + + align:start position:0% +assuming V is large everybody buys all +the time so what we get is uh + + align:start position:0% +the time so what we get is uh + + + align:start position:0% +the time so what we get is uh +differentiating this with respect to n + + align:start position:0% +differentiating this with respect to n + + + align:start position:0% +differentiating this with respect to n +derivative of this with respect to n is + + align:start position:0% +derivative of this with respect to n is + + + align:start position:0% +derivative of this with respect to n is +Mt over 4 * 1 n^ 2 derivative of this + + align:start position:0% +Mt over 4 * 1 n^ 2 derivative of this + + + align:start position:0% +Mt over 4 * 1 n^ 2 derivative of this +with respect to n is just + + align:start position:0% +with respect to n is just + + + align:start position:0% +with respect to n is just +K and so what I get is that Mt over 4 * + + align:start position:0% +K and so what I get is that Mt over 4 * + + + align:start position:0% +K and so what I get is that Mt over 4 * +1 n^2 minus k evalate n second best + + align:start position:0% +1 n^2 minus k evalate n second best + + + align:start position:0% +1 n^2 minus k evalate n second best +equals + + align:start position:0% +equals + + + align:start position:0% +equals +zero n second best is square root of Mt + + align:start position:0% +zero n second best is square root of Mt + + + align:start position:0% +zero n second best is square root of Mt +over + + align:start position:0% +over + + + align:start position:0% +over +4K which is exactly half of uh + + align:start position:0% +4K which is exactly half of uh + + + align:start position:0% +4K which is exactly half of uh +Nar so this is saying in some sense in + + align:start position:0% +Nar so this is saying in some sense in + + + align:start position:0% +Nar so this is saying in some sense in +equilibrium you get exactly twice as + + align:start position:0% +equilibrium you get exactly twice as + + + align:start position:0% +equilibrium you get exactly twice as +many firms as you would + + align:start position:0% +many firms as you would + + + align:start position:0% +many firms as you would +like um and this is just you know it's + + align:start position:0% +like um and this is just you know it's + + + align:start position:0% +like um and this is just you know it's +another case that in this model um you + + align:start position:0% +another case that in this model um you + + + align:start position:0% +another case that in this model um you +know maybe this so this model has the + + align:start position:0% +know maybe this so this model has the + + + align:start position:0% +know maybe this so this model has the +welfare benefit of people getting better + + align:start position:0% +welfare benefit of people getting better + + + align:start position:0% +welfare benefit of people getting better +matches um this model has no Market + + align:start position:0% +matches um this model has no Market + + + align:start position:0% +matches um this model has no Market +expansion effect whatsoever right when + + align:start position:0% +expansion effect whatsoever right when + + + align:start position:0% +expansion effect whatsoever right when +you put in an nth firm it's 100% + + align:start position:0% +you put in an nth firm it's 100% + + + align:start position:0% +you put in an nth firm it's 100% +business dealing and so it turns out + + align:start position:0% +business dealing and so it turns out + + + align:start position:0% +business dealing and so it turns out +that because the extra Market expansion + + align:start position:0% +that because the extra Market expansion + + + align:start position:0% +that because the extra Market expansion +is 100% business dealing so business + + align:start position:0% +is 100% business dealing so business + + + align:start position:0% +is 100% business dealing so business +dealing is a big deal this extra benefit + + align:start position:0% +dealing is a big deal this extra benefit + + + align:start position:0% +dealing is a big deal this extra benefit +that you get from extra match quality + + align:start position:0% +that you get from extra match quality + + + align:start position:0% +that you get from extra match quality +isn't nearly large enough to overcome + + align:start position:0% +isn't nearly large enough to overcome + + + align:start position:0% +isn't nearly large enough to overcome +the business dealing uh negative and + + align:start position:0% +the business dealing uh negative and + + + align:start position:0% +the business dealing uh negative and +you're getting twice as many firms and + + align:start position:0% +you're getting twice as many firms and + + + align:start position:0% +you're getting twice as many firms and +you know and I think you know in some + + align:start position:0% +you know and I think you know in some + + + align:start position:0% +you know and I think you know in some +sense I Al view this as a important + + align:start position:0% +sense I Al view this as a important + + + align:start position:0% +sense I Al view this as a important +question you like you're going to write + + align:start position:0% +question you like you're going to write + + + align:start position:0% +question you like you're going to write +down models with low at demand and + + align:start position:0% +down models with low at demand and + + + align:start position:0% +down models with low at demand and +estimate how many firms you're going to + + align:start position:0% +estimate how many firms you're going to + + + align:start position:0% +estimate how many firms you're going to +get and how many firms you think are + + align:start position:0% +get and how many firms you think are + + + align:start position:0% +get and how many firms you think are +optimal or whatever you know a lot of + + align:start position:0% +optimal or whatever you know a lot of + + + align:start position:0% +optimal or whatever you know a lot of +models like this are are set up you know + + align:start position:0% +models like this are are set up you know + + + align:start position:0% +models like this are are set up you know +again I could have done this model and I + + align:start position:0% +again I could have done this model and I + + + align:start position:0% +again I could have done this model and I +could have sort of said I'm estimating + + align:start position:0% +could have sort of said I'm estimating + + + align:start position:0% +could have sort of said I'm estimating +Demand elasticities by estimating + + align:start position:0% +Demand elasticities by estimating + + + align:start position:0% +Demand elasticities by estimating +T but whatever whatever value of t i + + align:start position:0% +T but whatever whatever value of t i + + + align:start position:0% +T but whatever whatever value of t i +estimated when I estimated this model my + + align:start position:0% +estimated when I estimated this model my + + + align:start position:0% +estimated when I estimated this model my +my model I do my counterfactual and say + + align:start position:0% +my model I do my counterfactual and say + + + align:start position:0% +my model I do my counterfactual and say +how many firms would be socially optimal + + align:start position:0% +how many firms would be socially optimal + + + align:start position:0% +how many firms would be socially optimal +and socially optimal would be exactly + + align:start position:0% +and socially optimal would be exactly + + + align:start position:0% +and socially optimal would be exactly +half the number that are observed um so + + align:start position:0% +half the number that are observed um so + + + align:start position:0% +half the number that are observed um so +it it's just important to be aware of do + + align:start position:0% +it it's just important to be aware of do + + + align:start position:0% +it it's just important to be aware of do +models have built in answers as to + + align:start position:0% +models have built in answers as to + + + align:start position:0% +models have built in answers as to +whether the consumer surplus effect is + + align:start position:0% +whether the consumer surplus effect is + + + align:start position:0% +whether the consumer surplus effect is +going to outweigh the business dealing + + align:start position:0% +going to outweigh the business dealing + + + align:start position:0% +going to outweigh the business dealing +effect or not and this one it's totally + + align:start position:0% +effect or not and this one it's totally + + + align:start position:0% +effect or not and this one it's totally +built in and the answer is it's a factor + + align:start position:0% +built in and the answer is it's a factor + + + align:start position:0% +built in and the answer is it's a factor +of two um but I think you know it's + + align:start position:0% +of two um but I think you know it's + + + align:start position:0% +of two um but I think you know it's +generally true you know most models you + + align:start position:0% +generally true you know most models you + + + align:start position:0% +generally true you know most models you +write down you are going to get like a + + align:start position:0% +write down you are going to get like a + + + align:start position:0% +write down you are going to get like a +fact you know you are going to find that + + align:start position:0% +fact you know you are going to find that + + + align:start position:0% +fact you know you are going to find that +there are way too many firms and I don't + + align:start position:0% +there are way too many firms and I don't + + + align:start position:0% +there are way too many firms and I don't +know if + + align:start position:0% +know if + + + align:start position:0% +know if +I maybe I believe that you know how + + align:start position:0% +I maybe I believe that you know how + + + align:start position:0% +I maybe I believe that you know how +would you get + + align:start position:0% +would you get + + + align:start position:0% +would you get +um you know how would you get um bigger + + align:start position:0% +um you know how would you get um bigger + + + align:start position:0% +um you know how would you get um bigger +social welfare benefits you know there's + + align:start position:0% +social welfare benefits you know there's + + + align:start position:0% +social welfare benefits you know there's +sort of two ways you would get bigger + + align:start position:0% +sort of two ways you would get bigger + + + align:start position:0% +sort of two ways you would get bigger +social welfare benefits the first is you + + align:start position:0% +social welfare benefits the first is you + + + align:start position:0% +social welfare benefits the first is you +in this model people's utility for + + align:start position:0% +in this model people's utility for + + + align:start position:0% +in this model people's utility for +getting a product that's not IDE deal + + align:start position:0% +getting a product that's not IDE deal + + + align:start position:0% +getting a product that's not IDE deal +just goes down + + align:start position:0% +just goes down + + + align:start position:0% +just goes down +linearly if you imagine people's utility + + align:start position:0% +linearly if you imagine people's utility + + + align:start position:0% +linearly if you imagine people's utility +looked more like this so you know there + + align:start position:0% +looked more like this so you know there + + + align:start position:0% +looked more like this so you know there +are people who really really like having + + align:start position:0% +are people who really really like having + + + align:start position:0% +are people who really really like having +a product that's very close to + + align:start position:0% +a product that's very close to + + + align:start position:0% +a product that's very close to +their um very close to their ideal point + + align:start position:0% +their um very close to their ideal point + + + align:start position:0% +their um very close to their ideal point +so when you add an extra and have three + + align:start position:0% +so when you add an extra and have three + + + align:start position:0% +so when you add an extra and have three +ideal points instead of two you're + + align:start position:0% +ideal points instead of two you're + + + align:start position:0% +ideal points instead of two you're +giving some people lots and lots of + + align:start position:0% +giving some people lots and lots of + + + align:start position:0% +giving some people lots and lots of +extra utility so having something like + + align:start position:0% +extra utility so having something like + + + align:start position:0% +extra utility so having something like +this you know people who like things + + align:start position:0% +this you know people who like things + + + align:start position:0% +this you know people who like things +very close to their ideal point would be + + align:start position:0% +very close to their ideal point would be + + + align:start position:0% +very close to their ideal point would be +would be one way to get uh ex entry to + + align:start position:0% +would be one way to get uh ex entry to + + + align:start position:0% +would be one way to get uh ex entry to +be not too high um obviously you can + + align:start position:0% +be not too high um obviously you can + + + align:start position:0% +be not too high um obviously you can +only go so high here before the firm is + + align:start position:0% +only go so high here before the firm is + + + align:start position:0% +only go so high here before the firm is +going to give up on serving everyone and + + align:start position:0% +going to give up on serving everyone and + + + align:start position:0% +going to give up on serving everyone and +just serve the people who like its + + align:start position:0% +just serve the people who like its + + + align:start position:0% +just serve the people who like its +product a lot at a really high price um + + align:start position:0% +product a lot at a really high price um + + + align:start position:0% +product a lot at a really high price um +so that's going to be kind of like those + + align:start position:0% +so that's going to be kind of like those + + + align:start position:0% +so that's going to be kind of like those +information design things where you can + + align:start position:0% +information design things where you can + + + align:start position:0% +information design things where you can +only make the curve go up so much and + + align:start position:0% +only make the curve go up so much and + + + align:start position:0% +only make the curve go up so much and +have the firm still sell to everybody uh + + align:start position:0% +have the firm still sell to everybody uh + + + align:start position:0% +have the firm still sell to everybody uh +and then the other effect is you know + + align:start position:0% +and then the other effect is you know + + + align:start position:0% +and then the other effect is you know +here again 100% of your demand is + + align:start position:0% +here again 100% of your demand is + + + align:start position:0% +here again 100% of your demand is +business stealing if you think of like + + align:start position:0% +business stealing if you think of like + + + align:start position:0% +business stealing if you think of like +an infinite dimensional space where most + + align:start position:0% +an infinite dimensional space where most + + + align:start position:0% +an infinite dimensional space where most +people are not buying any product at all + + align:start position:0% +people are not buying any product at all + + + align:start position:0% +people are not buying any product at all +all so every new firm that comes in is + + align:start position:0% +all so every new firm that comes in is + + + align:start position:0% +all so every new firm that comes in is +mostly serving new customers you know so + + align:start position:0% +mostly serving new customers you know so + + + align:start position:0% +mostly serving new customers you know so +if you can make the business dealing + + align:start position:0% +if you can make the business dealing + + + align:start position:0% +if you can make the business dealing +effect small and make this consumer + + align:start position:0% +effect small and make this consumer + + + align:start position:0% +effect small and make this consumer +surplus large for people who get close + + align:start position:0% +surplus large for people who get close + + + align:start position:0% +surplus large for people who get close +matches those are the things that are + + align:start position:0% +matches those are the things that are + + + align:start position:0% +matches those are the things that are +going to make entry be insufficient in + + align:start position:0% + + + + align:start position:0% + +practice and I but I think if you want + + align:start position:0% +practice and I but I think if you want + + + align:start position:0% +practice and I but I think if you want +to do an empirical study you'd really + + align:start position:0% +to do an empirical study you'd really + + + align:start position:0% +to do an empirical study you'd really +want to think about do I have free + + align:start position:0% +want to think about do I have free + + + align:start position:0% +want to think about do I have free +parameters to capture what this Surplus + + align:start position:0% +parameters to capture what this Surplus + + + align:start position:0% +parameters to capture what this Surplus +looks like and do I have a free cap + + align:start position:0% +looks like and do I have a free cap + + + align:start position:0% +looks like and do I have a free cap +parameter to capture how much of the + + align:start position:0% +parameter to capture how much of the + + + align:start position:0% +parameter to capture how much of the +people are being added um to the model + + align:start position:0% +people are being added um to the model + + + align:start position:0% +people are being added um to the model +versus how many people are just business + + align:start position:0% +versus how many people are just business + + + align:start position:0% +versus how many people are just business +being business St for another + + align:start position:0% + + + + align:start position:0% + +firm you know for instance like the + + align:start position:0% +firm you know for instance like the + + + align:start position:0% +firm you know for instance like the +nested loit has that extra parameter + + align:start position:0% +nested loit has that extra parameter + + + align:start position:0% +nested loit has that extra parameter +that substitution to the outside good is + + align:start position:0% +that substitution to the outside good is + + + align:start position:0% +that substitution to the outside good is +different from substitution to the + + align:start position:0% +different from substitution to the + + + align:start position:0% +different from substitution to the +inside Goods um and a pure loia with no + + align:start position:0% +inside Goods um and a pure loia with no + + + align:start position:0% +inside Goods um and a pure loia with no +outside good is a 100% business dealing + + align:start position:0% +outside good is a 100% business dealing + + + align:start position:0% +outside good is a 100% business dealing +model + + align:start position:0% +model + + + align:start position:0% +model +questions okay um entry with vertical + + align:start position:0% +questions okay um entry with vertical + + + align:start position:0% +questions okay um entry with vertical +differentiation + + align:start position:0% + + + + align:start position:0% + +okay so let's go back again review of + + align:start position:0% +okay so let's go back again review of + + + align:start position:0% +okay so let's go back again review of +our classic um vertical differentiation + + align:start position:0% +our classic um vertical differentiation + + + align:start position:0% +our classic um vertical differentiation +model you have consumers that have these + + align:start position:0% +model you have consumers that have these + + + align:start position:0% +model you have consumers that have these +vertical types Theta uh they have unit + + align:start position:0% +vertical types Theta uh they have unit + + + align:start position:0% +vertical types Theta uh they have unit +demands where you your utility is Theta + + align:start position:0% +demands where you your utility is Theta + + + align:start position:0% +demands where you your utility is Theta +times the quality of the good minus + + align:start position:0% +times the quality of the good minus + + + align:start position:0% +times the quality of the good minus +p uh let's assume that firms have fixed + + align:start position:0% +p uh let's assume that firms have fixed + + + align:start position:0% +p uh let's assume that firms have fixed +entry cost K and then they have constant + + align:start position:0% +entry cost K and then they have constant + + + align:start position:0% +entry cost K and then they have constant +marginal cost C ofs where the higher + + align:start position:0% +marginal cost C ofs where the higher + + + align:start position:0% +marginal cost C ofs where the higher +quality products are more expensive to + + align:start position:0% +quality products are more expensive to + + + align:start position:0% +quality products are more expensive to +produce so consider a two-stage game the + + align:start position:0% +produce so consider a two-stage game the + + + align:start position:0% +produce so consider a two-stage game the +first the firms are simultaneously + + align:start position:0% +first the firms are simultaneously + + + align:start position:0% +first the firms are simultaneously +choosing whether to enter and if they + + align:start position:0% +choosing whether to enter and if they + + + align:start position:0% +choosing whether to enter and if they +enter they're going to choose which + + align:start position:0% +enter they're going to choose which + + + align:start position:0% +enter they're going to choose which +quality level to + + align:start position:0% +quality level to + + + align:start position:0% +quality level to +produce uh and then once they've done + + align:start position:0% +produce uh and then once they've done + + + align:start position:0% +produce uh and then once they've done +that they compete in prices according to + + align:start position:0% +that they compete in prices according to + + + align:start position:0% +that they compete in prices according to +the vertical differentiation + + align:start position:0% +the vertical differentiation + + + align:start position:0% +the vertical differentiation +model and you know shacket and suton + + align:start position:0% +model and you know shacket and suton + + + align:start position:0% +model and you know shacket and suton +have this classic paper that shows that + + align:start position:0% +have this classic paper that shows that + + + align:start position:0% +have this classic paper that shows that +um you can get two different types of + + align:start position:0% +um you can get two different types of + + + align:start position:0% +um you can get two different types of +outcomes in this um first one is what + + align:start position:0% +outcomes in this um first one is what + + + align:start position:0% +outcomes in this um first one is what +they call the sort of natural lopoly + + align:start position:0% + + + + align:start position:0% + +case so imagine that + + align:start position:0% +case so imagine that + + + align:start position:0% +case so imagine that +um if I put s on this axis and I put + + align:start position:0% +um if I put s on this axis and I put + + + align:start position:0% +um if I put s on this axis and I put +uh what am I going to do + + align:start position:0% +uh what am I going to do + + + align:start position:0% +uh what am I going to do +um you know uh either the value that + + align:start position:0% +um you know uh either the value that + + + align:start position:0% +um you know uh either the value that +they get from s Theta s minus p on this + + align:start position:0% +they get from s Theta s minus p on this + + + align:start position:0% +they get from s Theta s minus p on this +Axis or I put C of s on this axis + + align:start position:0% +Axis or I put C of s on this axis + + + align:start position:0% +Axis or I put C of s on this axis +um so imagine that um + + align:start position:0% + + + + align:start position:0% + +you imagine that you have relatively + + align:start position:0% +you imagine that you have relatively + + + align:start position:0% +you imagine that you have relatively +flat marginal cost curves so imagine + + align:start position:0% +flat marginal cost curves so imagine + + + align:start position:0% +flat marginal cost curves so imagine +that marginal cost um C of s looks like + + align:start position:0% +that marginal cost um C of s looks like + + + align:start position:0% +that marginal cost um C of s looks like +this that there's just not that much + + align:start position:0% +this that there's just not that much + + + align:start position:0% +this that there's just not that much +cost to producing high quality goods and + + align:start position:0% +cost to producing high quality goods and + + + align:start position:0% +cost to producing high quality goods and +suppose that you have like you know + + align:start position:0% +suppose that you have like you know + + + align:start position:0% +suppose that you have like you know +Theta lower bar um Time s looks like + + align:start position:0% +Theta lower bar um Time s looks like + + + align:start position:0% +Theta lower bar um Time s looks like +this + + align:start position:0% +this + + + align:start position:0% +this +and Theta upper bar + + align:start position:0% +and Theta upper bar + + + align:start position:0% +and Theta upper bar +s minus P looks like that okay so we + + align:start position:0% +s minus P looks like that okay so we + + + align:start position:0% +s minus P looks like that okay so we +have a model where everybody even the + + align:start position:0% +have a model where everybody even the + + + align:start position:0% +have a model where everybody even the +lowest possible types value quality more + + align:start position:0% +lowest possible types value quality more + + + align:start position:0% +lowest possible types value quality more +than it cost to produce the extra units + + align:start position:0% +than it cost to produce the extra units + + + align:start position:0% +than it cost to produce the extra units +of + + align:start position:0% +of + + + align:start position:0% +of +quality okay and there's some range here + + align:start position:0% +quality okay and there's some range here + + + align:start position:0% +quality okay and there's some range here +oops uh s lower bar s uper bar of the + + align:start position:0% +oops uh s lower bar s uper bar of the + + + align:start position:0% +oops uh s lower bar s uper bar of the +qualities that are available to be + + align:start position:0% +qualities that are available to be + + + align:start position:0% +qualities that are available to be +produced + + align:start position:0% +produced + + + align:start position:0% +produced +okay in a model like this what they call + + align:start position:0% +okay in a model like this what they call + + + align:start position:0% +okay in a model like this what they call +the natural oligopoly case + + align:start position:0% +the natural oligopoly case + + + align:start position:0% +the natural oligopoly case +everybody should efficient in an + + align:start position:0% +everybody should efficient in an + + + align:start position:0% +everybody should efficient in an +efficient market everyone should be + + align:start position:0% +efficient market everyone should be + + + align:start position:0% +efficient market everyone should be +buying the highest possible + + align:start position:0% + + + + align:start position:0% + +quality and so if you imagine what + + align:start position:0% +quality and so if you imagine what + + + align:start position:0% +quality and so if you imagine what +happened suppose you + + align:start position:0% +happened suppose you + + + align:start position:0% +happened suppose you +have firms lots of firms entering and + + align:start position:0% +have firms lots of firms entering and + + + align:start position:0% +have firms lots of firms entering and +producing different qualities and then + + align:start position:0% +producing different qualities and then + + + align:start position:0% +producing different qualities and then +what are they going to set their prices + + align:start position:0% +what are they going to set their prices + + + align:start position:0% +what are they going to set their prices +at okay well if you have lots of firms + + align:start position:0% +at okay well if you have lots of firms + + + align:start position:0% +at okay well if you have lots of firms +in the market the prices are going to + + align:start position:0% +in the market the prices are going to + + + align:start position:0% +in the market the prices are going to +fall you know these are prices I'm + + align:start position:0% +fall you know these are prices I'm + + + align:start position:0% +fall you know these are prices I'm +putting dots in here you know the prices + + align:start position:0% +putting dots in here you know the prices + + + align:start position:0% +putting dots in here you know the prices +are going to have to fall towards cost + + align:start position:0% +are going to have to fall towards cost + + + align:start position:0% +are going to have to fall towards cost +as n goes to as the number of firms into + + align:start position:0% +as n goes to as the number of firms into + + + align:start position:0% +as n goes to as the number of firms into +this finite product space goes to + + align:start position:0% +this finite product space goes to + + + align:start position:0% +this finite product space goes to +Infinity but then if the prices fall + + align:start position:0% +Infinity but then if the prices fall + + + align:start position:0% +Infinity but then if the prices fall +towards cost everyone is going to buy + + align:start position:0% +towards cost everyone is going to buy + + + align:start position:0% +towards cost everyone is going to buy +from the highest quality + + align:start position:0% +from the highest quality + + + align:start position:0% +from the highest quality +firm and so you just can't have prices + + align:start position:0% +firm and so you just can't have prices + + + align:start position:0% +firm and so you just can't have prices +falling to cost because if prices fall + + align:start position:0% +falling to cost because if prices fall + + + align:start position:0% +falling to cost because if prices fall +to cost all these firms make zero sales + + align:start position:0% +to cost all these firms make zero sales + + + align:start position:0% +to cost all these firms make zero sales +and then they are negative profits after + + align:start position:0% +and then they are negative profits after + + + align:start position:0% +and then they are negative profits after +paying their fixed cost + + align:start position:0% +paying their fixed cost + + + align:start position:0% +paying their fixed cost +K so if you have have this case where + + align:start position:0% +K so if you have have this case where + + + align:start position:0% +K so if you have have this case where +everybody should buy the same product + + align:start position:0% +everybody should buy the same product + + + align:start position:0% +everybody should buy the same product +there's only a finite number of firms in + + align:start position:0% +there's only a finite number of firms in + + + align:start position:0% +there's only a finite number of firms in +the market again this isn't an end goes + + align:start position:0% +the market again this isn't an end goes + + + align:start position:0% +the market again this isn't an end goes +to Infinity as K goes to zero for you + + align:start position:0% +to Infinity as K goes to zero for you + + + align:start position:0% +to Infinity as K goes to zero for you +know as K goes to zero you still get a + + align:start position:0% +know as K goes to zero you still get a + + + align:start position:0% +know as K goes to zero you still get a +finite number of firms it may be this + + align:start position:0% +finite number of firms it may be this + + + align:start position:0% +finite number of firms it may be this +Market can fit three firms or five or + + align:start position:0% +Market can fit three firms or five or + + + align:start position:0% +Market can fit three firms or five or +sixs or whatever but there's a finite + + align:start position:0% +sixs or whatever but there's a finite + + + align:start position:0% +sixs or whatever but there's a finite +amount of Entry that can ever + + align:start position:0% +amount of Entry that can ever + + + align:start position:0% +amount of Entry that can ever +occur uh if the same product is + + align:start position:0% +occur uh if the same product is + + + align:start position:0% +occur uh if the same product is +efficient for everyone to + + align:start position:0% + + + + align:start position:0% + +buy and then the second case they talk + + align:start position:0% +buy and then the second case they talk + + + align:start position:0% +buy and then the second case they talk +about is this specialization case um the + + align:start position:0% +about is this specialization case um the + + + align:start position:0% +about is this specialization case um the +specialization case would be if you have + + align:start position:0% +specialization case would be if you have + + + align:start position:0% +specialization case would be if you have +marginal + + align:start position:0% +marginal + + + align:start position:0% +marginal +costs that look like this you know + + align:start position:0% +costs that look like this you know + + + align:start position:0% +costs that look like this you know +marginal costs are initially + + align:start position:0% +marginal costs are initially + + + align:start position:0% +marginal costs are initially +low + + align:start position:0% +low + + + align:start position:0% +low +um uh but then they shoot up like + + align:start position:0% + + + + align:start position:0% + +that okay if the marginal cost look like + + align:start position:0% +that okay if the marginal cost look like + + + align:start position:0% +that okay if the marginal cost look like +this right what's efficient for the + + align:start position:0% +this right what's efficient for the + + + align:start position:0% +this right what's efficient for the +Theta lower bar types the Theta lower + + align:start position:0% +Theta lower bar types the Theta lower + + + align:start position:0% +Theta lower bar types the Theta lower +bar types you know would + + align:start position:0% +bar types you know would + + + align:start position:0% +bar types you know would +pick the point you know right what's + + align:start position:0% +pick the point you know right what's + + + align:start position:0% +pick the point you know right what's +sufficient for them to do is where the + + align:start position:0% +sufficient for them to do is where the + + + align:start position:0% +sufficient for them to do is where the +marginal cost of producing extra quality + + align:start position:0% +marginal cost of producing extra quality + + + align:start position:0% +marginal cost of producing extra quality +is equal to the marginal benefit that + + align:start position:0% +is equal to the marginal benefit that + + + align:start position:0% +is equal to the marginal benefit that +they receive so the Theta lower bar + + align:start position:0% +they receive so the Theta lower bar + + + align:start position:0% +they receive so the Theta lower bar +types so this would be you know s star + + align:start position:0% +types so this would be you know s star + + + align:start position:0% +types so this would be you know s star +optimal uh for the Theta lower bar types + + align:start position:0% +optimal uh for the Theta lower bar types + + + align:start position:0% +optimal uh for the Theta lower bar types +they want to produce where the they + + align:start position:0% +they want to produce where the they + + + align:start position:0% +they want to produce where the they +should be buying the good where the + + align:start position:0% +should be buying the good where the + + + align:start position:0% +should be buying the good where the +marginal value of increase in quality is + + align:start position:0% +marginal value of increase in quality is + + + align:start position:0% +marginal value of increase in quality is +exactly equal to their willingness to + + align:start position:0% +exactly equal to their willingness to + + + align:start position:0% +exactly equal to their willingness to +pay and the Theta upper bar types maybe + + align:start position:0% +pay and the Theta upper bar types maybe + + + align:start position:0% +pay and the Theta upper bar types maybe +I should have made this steeper + + align:start position:0% +I should have made this steeper + + + align:start position:0% +I should have made this steeper +let me make Theta upper bar even steeper + + align:start position:0% +let me make Theta upper bar even steeper + + + align:start position:0% +let me make Theta upper bar even steeper +you know the Theta upper bar types are + + align:start position:0% +you know the Theta upper bar types are + + + align:start position:0% +you know the Theta upper bar types are +going to have a point where again + + align:start position:0% +going to have a point where again + + + align:start position:0% +going to have a point where again +they're going to buy up here where it + + align:start position:0% +they're going to buy up here where it + + + align:start position:0% +they're going to buy up here where it +has this greater slope so the SAR uh + + align:start position:0% +has this greater slope so the SAR uh + + + align:start position:0% +has this greater slope so the SAR uh +Theta upper bar they should be buying + + align:start position:0% +Theta upper bar they should be buying + + + align:start position:0% +Theta upper bar they should be buying +this + + align:start position:0% +this + + + align:start position:0% +this +product and everybody with a Theta in + + align:start position:0% +product and everybody with a Theta in + + + align:start position:0% +product and everybody with a Theta in +between should be buying something in + + align:start position:0% +between should be buying something in + + + align:start position:0% +between should be buying something in +between everybody should be picking the + + align:start position:0% +between everybody should be picking the + + + align:start position:0% +between everybody should be picking the +optimal product for everybody is the + + align:start position:0% +optimal product for everybody is the + + + align:start position:0% +optimal product for everybody is the +point on that curve that where + + align:start position:0% +point on that curve that where + + + align:start position:0% +point on that curve that where +you know it's efficient quality for them + + align:start position:0% +you know it's efficient quality for them + + + align:start position:0% +you know it's efficient quality for them +okay so if you have a model like this + + align:start position:0% +okay so if you have a model like this + + + align:start position:0% +okay so if you have a model like this +where efficient + + align:start position:0% +where efficient + + + align:start position:0% +where efficient +quality you know some people everybody + + align:start position:0% +quality you know some people everybody + + + align:start position:0% +quality you know some people everybody +has a different efficient quality then + + align:start position:0% +has a different efficient quality then + + + align:start position:0% +has a different efficient quality then +as then goes to Infinity you are going + + align:start position:0% +as then goes to Infinity you are going + + + align:start position:0% +as then goes to Infinity you are going +to get an infinitely divided model so + + align:start position:0% +to get an infinitely divided model so + + + align:start position:0% +to get an infinitely divided model so +every product is efficient for someone + + align:start position:0% +every product is efficient for someone + + + align:start position:0% +every product is efficient for someone +so the number of customers is large + + align:start position:0% +so the number of customers is large + + + align:start position:0% +so the number of customers is large +every all those products get produced + + align:start position:0% +every all those products get produced + + + align:start position:0% +every all those products get produced +they all sell to one over n of the + + align:start position:0% +they all sell to one over n of the + + + align:start position:0% +they all sell to one over n of the +people they sell to the people whose + + align:start position:0% +people they sell to the people whose + + + align:start position:0% +people they sell to the people whose +prices are whose values are marginal + + align:start position:0% +prices are whose values are marginal + + + align:start position:0% +prices are whose values are marginal +values are close to their marginal yes + + align:start position:0% +values are close to their marginal yes + + + align:start position:0% +values are close to their marginal yes +whose optimal qualities are close to + + align:start position:0% +whose optimal qualities are close to + + + align:start position:0% +whose optimal qualities are close to +their quality and and prices do fall + + align:start position:0% +their quality and and prices do fall + + + align:start position:0% +their quality and and prices do fall +towards marginal cost but even though + + align:start position:0% +towards marginal cost but even though + + + align:start position:0% +towards marginal cost but even though +prices fall to marginal cost everybody + + align:start position:0% +prices fall to marginal cost everybody + + + align:start position:0% +prices fall to marginal cost everybody +still buys a from a different + + align:start position:0% +still buys a from a different + + + align:start position:0% +still buys a from a different +firm so what happens with vertical + + align:start position:0% +firm so what happens with vertical + + + align:start position:0% +firm so what happens with vertical +differentiation is sometimes you only + + align:start position:0% +differentiation is sometimes you only + + + align:start position:0% +differentiation is sometimes you only +you can't get a lot of firms but + + align:start position:0% +you can't get a lot of firms but + + + align:start position:0% +you can't get a lot of firms but +sometimes you get the specialization and + + align:start position:0% +sometimes you get the specialization and + + + align:start position:0% +sometimes you get the specialization and +it all depends on whether different + + align:start position:0% +it all depends on whether different + + + align:start position:0% +it all depends on whether different +products are optimal for a different + + align:start position:0% +products are optimal for a different + + + align:start position:0% +products are optimal for a different +people + + align:start position:0% + + + + align:start position:0% + +questions okay um so next thing next set + + align:start position:0% +questions okay um so next thing next set + + + align:start position:0% +questions okay um so next thing next set +of paper I want next paper I want to + + align:start position:0% +of paper I want next paper I want to + + + align:start position:0% +of paper I want next paper I want to +discuss is you know this paper is + + align:start position:0% +discuss is you know this paper is + + + align:start position:0% +discuss is you know this paper is +motivated by um there's a large + + align:start position:0% +motivated by um there's a large + + + align:start position:0% +motivated by um there's a large +literature on firm Dynamics and entry + + align:start position:0% +literature on firm Dynamics and entry + + + align:start position:0% +literature on firm Dynamics and entry +and exit uh that's generated by people + + align:start position:0% +and exit uh that's generated by people + + + align:start position:0% +and exit uh that's generated by people +looking at Census Data um so you know if + + align:start position:0% +looking at Census Data um so you know if + + + align:start position:0% +looking at Census Data um so you know if +um I don't know if I mentioned I think I + + align:start position:0% +um I don't know if I mentioned I think I + + + align:start position:0% +um I don't know if I mentioned I think I +mentioned this earlier in the semester + + align:start position:0% +mentioned this earlier in the semester + + + align:start position:0% +mentioned this earlier in the semester +so you know there's this great resource + + align:start position:0% +so you know there's this great resource + + + align:start position:0% +so you know there's this great resource +for Io Economist which is called the um + + align:start position:0% +for Io Economist which is called the um + + + align:start position:0% +for Io Economist which is called the um +uh you know sense to + + align:start position:0% +uh you know sense to + + + align:start position:0% +uh you know sense to +manufacturers so + + align:start position:0% + + + + align:start position:0% + +the you the sense of Manufacturers is + + align:start position:0% +the you the sense of Manufacturers is + + + align:start position:0% +the you the sense of Manufacturers is +conducted by the US Census Bureau every + + align:start position:0% +conducted by the US Census Bureau every + + + align:start position:0% +conducted by the US Census Bureau every +five years um all the years that end in + + align:start position:0% +five years um all the years that end in + + + align:start position:0% +five years um all the years that end in +twos and sevens + + align:start position:0% +twos and sevens + + + align:start position:0% +twos and sevens +um sens of Manufacturers it's a complete + + align:start position:0% +um sens of Manufacturers it's a complete + + + align:start position:0% +um sens of Manufacturers it's a complete +census of every manufacturing firm in + + align:start position:0% +census of every manufacturing firm in + + + align:start position:0% +census of every manufacturing firm in +the United + + align:start position:0% +the United + + + align:start position:0% +the United +States uh in addition there census does + + align:start position:0% +States uh in addition there census does + + + align:start position:0% +States uh in addition there census does +something called the annual survey of + + align:start position:0% +something called the annual survey of + + + align:start position:0% +something called the annual survey of +Manufacturers it takes a subset of this + + align:start position:0% +Manufacturers it takes a subset of this + + + align:start position:0% +Manufacturers it takes a subset of this +and samples them to produce annual data + + align:start position:0% +and samples them to produce annual data + + + align:start position:0% +and samples them to produce annual data +instead of every fiveyear data um but + + align:start position:0% +instead of every fiveyear data um but + + + align:start position:0% +instead of every fiveyear data um but +anyway they sort + + align:start position:0% +anyway they sort + + + align:start position:0% +anyway they sort +of send out census forms to all + + align:start position:0% +of send out census forms to all + + + align:start position:0% +of send out census forms to all +manufacturing firms every five years + + align:start position:0% +manufacturing firms every five years + + + align:start position:0% +manufacturing firms every five years +asking them lots and lots of questions + + align:start position:0% +asking them lots and lots of questions + + + align:start position:0% +asking them lots and lots of questions +you know what do they produce how many + + align:start position:0% +you know what do they produce how many + + + align:start position:0% +you know what do they produce how many +you know how much do they sell of every + + align:start position:0% +you know how much do they sell of every + + + align:start position:0% +you know how much do they sell of every +different you know narrowly defined + + align:start position:0% +different you know narrowly defined + + + align:start position:0% +different you know narrowly defined +product how many employees do you have + + align:start position:0% +product how many employees do you have + + + align:start position:0% +product how many employees do you have +what's the value of your plant and + + align:start position:0% +what's the value of your plant and + + + align:start position:0% +what's the value of your plant and +Equipment how much electricity do you + + align:start position:0% +Equipment how much electricity do you + + + align:start position:0% +Equipment how much electricity do you +use so you get lots of data on these + + align:start position:0% +use so you get lots of data on these + + + align:start position:0% +use so you get lots of data on these +firms sometimes you know the accounting + + align:start position:0% +firms sometimes you know the accounting + + + align:start position:0% +firms sometimes you know the accounting +data of what are all their costs are + + align:start position:0% +data of what are all their costs are + + + align:start position:0% +data of what are all their costs are +hard to believe but one thing that's + + align:start position:0% +hard to believe but one thing that's + + + align:start position:0% +hard to believe but one thing that's +very good in that data is do you exist + + align:start position:0% +very good in that data is do you exist + + + align:start position:0% +very good in that data is do you exist +what's your address uh how many + + align:start position:0% +what's your address uh how many + + + align:start position:0% +what's your address uh how many +employees do you have um and so you know + + align:start position:0% +employees do you have um and so you know + + + align:start position:0% +employees do you have um and so you know +this lets you sort of if you want to + + align:start position:0% +this lets you sort of if you want to + + + align:start position:0% +this lets you sort of if you want to +study entry and exit that you can just + + align:start position:0% +study entry and exit that you can just + + + align:start position:0% +study entry and exit that you can just +you know there's a windowless room at + + align:start position:0% +you know there's a windowless room at + + + align:start position:0% +you know there's a windowless room at +the NBR where one can access census data + + align:start position:0% +the NBR where one can access census data + + + align:start position:0% +the NBR where one can access census data +now as a graduate student one of the + + align:start position:0% +now as a graduate student one of the + + + align:start position:0% +now as a graduate student one of the +difficulties is that um you try to + + align:start position:0% +difficulties is that um you try to + + + align:start position:0% +difficulties is that um you try to +access it through the NBR and there's + + align:start position:0% +access it through the NBR and there's + + + align:start position:0% +access it through the NBR and there's +like a two-year application process to + + align:start position:0% +like a two-year application process to + + + align:start position:0% +like a two-year application process to +be approved as a special sworn employee + + align:start position:0% +be approved as a special sworn employee + + + align:start position:0% +be approved as a special sworn employee +of the census and you know two years is + + align:start position:0% +of the census and you know two years is + + + align:start position:0% +of the census and you know two years is +a long time for a graduate student I + + align:start position:0% +a long time for a graduate student I + + + align:start position:0% +a long time for a graduate student I +don't know if I should say this on + + align:start position:0% +don't know if I should say this on + + + align:start position:0% +don't know if I should say this on +camera you know I think what people + + align:start position:0% +camera you know I think what people + + + align:start position:0% +camera you know I think what people +often do if they want to access census + + align:start position:0% +often do if they want to access census + + + align:start position:0% +often do if they want to access census +data is they get a ra job working with + + align:start position:0% +data is they get a ra job working with + + + align:start position:0% +data is they get a ra job working with +someone who has access to the Census + + align:start position:0% +someone who has access to the Census + + + align:start position:0% +someone who has access to the Census +Data learn the Census Data well enough + + align:start position:0% +Data learn the Census Data well enough + + + align:start position:0% +Data learn the Census Data well enough +that they can describe all of the + + align:start position:0% +that they can describe all of the + + + align:start position:0% +that they can describe all of the +regressions and code that they will run + + align:start position:0% +regressions and code that they will run + + + align:start position:0% +regressions and code that they will run +when they get access to the census data + + align:start position:0% +when they get access to the census data + + + align:start position:0% +when they get access to the census data +and then they have all the programs + + align:start position:0% +and then they have all the programs + + + align:start position:0% +and then they have all the programs +entirely written to just push the Run + + align:start position:0% +entirely written to just push the Run + + + align:start position:0% +entirely written to just push the Run +button when their access is eventually + + align:start position:0% +button when their access is eventually + + + align:start position:0% +button when their access is eventually +approved two years later and then they + + align:start position:0% +approved two years later and then they + + + align:start position:0% +approved two years later and then they +you know can write their paper using the + + align:start position:0% +you know can write their paper using the + + + align:start position:0% +you know can write their paper using the +Sens of manufacturer data um but anyway + + align:start position:0% +Sens of manufacturer data um but anyway + + + align:start position:0% +Sens of manufacturer data um but anyway +it's you know one thing that's very good + + align:start position:0% +it's you know one thing that's very good + + + align:start position:0% +it's you know one thing that's very good +to a Sensi data is you can get very good + + align:start position:0% +to a Sensi data is you can get very good + + + align:start position:0% +to a Sensi data is you can get very good +statistics on + + align:start position:0% +statistics on + + + align:start position:0% +statistics on +um you know how many firms enter every 5 + + align:start position:0% +um you know how many firms enter every 5 + + + align:start position:0% +um you know how many firms enter every 5 +years how many firms grow like you know + + align:start position:0% +years how many firms grow like you know + + + align:start position:0% +years how many firms grow like you know +of firms that enter in in a 5year period + + align:start position:0% +of firms that enter in in a 5year period + + + align:start position:0% +of firms that enter in in a 5year period +how many of them uh are still there five + + align:start position:0% +how many of them uh are still there five + + + align:start position:0% +how many of them uh are still there five +years later of the ones that are still + + align:start position:0% +years later of the ones that are still + + + align:start position:0% +years later of the ones that are still +there five years later how many of them + + align:start position:0% +there five years later how many of them + + + align:start position:0% +there five years later how many of them +have grown how many of them have + + align:start position:0% +have grown how many of them have + + + align:start position:0% +have grown how many of them have +shrunk what's what's the relative + + align:start position:0% +shrunk what's what's the relative + + + align:start position:0% +shrunk what's what's the relative +profitability of the new firms versus + + align:start position:0% +profitability of the new firms versus + + + align:start position:0% +profitability of the new firms versus +the old firms um so there's a set of old + + align:start position:0% +the old firms um so there's a set of old + + + align:start position:0% +the old firms um so there's a set of old +papers I used to um teach here um you + + align:start position:0% +papers I used to um teach here um you + + + align:start position:0% +papers I used to um teach here um you +know obviously uh the you know classic + + align:start position:0% +know obviously uh the you know classic + + + align:start position:0% +know obviously uh the you know classic +one that's on my still on my syllabus is + + align:start position:0% +one that's on my still on my syllabus is + + + align:start position:0% +one that's on my still on my syllabus is +uh dun Roberts and + + align:start position:0% +uh dun Roberts and + + + align:start position:0% +uh dun Roberts and +Samuelson uh from the + + align:start position:0% +Samuelson uh from the + + + align:start position:0% +Samuelson uh from the +1970s that has first sort of just wrote + + align:start position:0% +1970s that has first sort of just wrote + + + align:start position:0% +1970s that has first sort of just wrote +lots and lots of statistics on what this + + align:start position:0% +lots and lots of statistics on what this + + + align:start position:0% +lots and lots of statistics on what this +sort of entry and exit looked like in + + align:start position:0% +sort of entry and exit looked like in + + + align:start position:0% +sort of entry and exit looked like in +the Census Data but you could sort of + + align:start position:0% +the Census Data but you could sort of + + + align:start position:0% +the Census Data but you could sort of +search for things that have cited to + + align:start position:0% +search for things that have cited to + + + align:start position:0% +search for things that have cited to +find many updates since then but let me + + align:start position:0% +find many updates since then but let me + + + align:start position:0% +find many updates since then but let me +say you know some of this sort of + + align:start position:0% +say you know some of this sort of + + + align:start position:0% +say you know some of this sort of +stylized facts here is that according to + + align:start position:0% +stylized facts here is that according to + + + align:start position:0% +stylized facts here is that according to +the census dat at least there's a lot of + + align:start position:0% +the census dat at least there's a lot of + + + align:start position:0% +the census dat at least there's a lot of +entry and exit uh and I think you know I + + align:start position:0% +entry and exit uh and I think you know I + + + align:start position:0% +entry and exit uh and I think you know I +think in some Industries we we know this + + align:start position:0% +think in some Industries we we know this + + + align:start position:0% +think in some Industries we we know this +like if you watch restaurants or + + align:start position:0% +like if you watch restaurants or + + + align:start position:0% +like if you watch restaurants or +something like that you're just aware + + align:start position:0% +something like that you're just aware + + + align:start position:0% +something like that you're just aware +that new restaurants are born all the + + align:start position:0% +that new restaurants are born all the + + + align:start position:0% +that new restaurants are born all the +time restaurants die all the time + + align:start position:0% +time restaurants die all the time + + + align:start position:0% +time restaurants die all the time +there's a tremendous amount of entry and + + align:start position:0% +there's a tremendous amount of entry and + + + align:start position:0% +there's a tremendous amount of entry and +exit into the restaurant business well + + align:start position:0% +exit into the restaurant business well + + + align:start position:0% +exit into the restaurant business well +the sort of surprising result from dun + + align:start position:0% +the sort of surprising result from dun + + + align:start position:0% +the sort of surprising result from dun +Roberts and Samson is that lots of other + + align:start position:0% +Roberts and Samson is that lots of other + + + align:start position:0% +Roberts and Samson is that lots of other +businesses seem to look like that too um + + align:start position:0% +businesses seem to look like that too um + + + align:start position:0% +businesses seem to look like that too um +now it you know it's not the case that + + align:start position:0% +now it you know it's not the case that + + + align:start position:0% +now it you know it's not the case that +there's a tremendous number of new + + align:start position:0% +there's a tremendous number of new + + + align:start position:0% +there's a tremendous number of new +apples and Samsungs every five years um + + align:start position:0% +apples and Samsungs every five years um + + + align:start position:0% +apples and Samsungs every five years um +but if you look at the firms that are + + align:start position:0% +but if you look at the firms that are + + + align:start position:0% +but if you look at the firms that are +classified into many narrowly defined + + align:start position:0% +classified into many narrowly defined + + + align:start position:0% +classified into many narrowly defined +businesses it seems like many more are + + align:start position:0% +businesses it seems like many more are + + + align:start position:0% +businesses it seems like many more are +like the um many more are like the + + align:start position:0% +like the um many more are like the + + + align:start position:0% +like the um many more are like the +restaurants than like the Apple and + + align:start position:0% +restaurants than like the Apple and + + + align:start position:0% +restaurants than like the Apple and +Samsung phone + + align:start position:0% +Samsung phone + + + align:start position:0% +Samsung phone +producers um anyway so what you know + + align:start position:0% +producers um anyway so what you know + + + align:start position:0% +producers um anyway so what you know +jovovich's paper is about trying to + + align:start position:0% +jovovich's paper is about trying to + + + align:start position:0% +jovovich's paper is about trying to +discuss you know just basic framework + + align:start position:0% +discuss you know just basic framework + + + align:start position:0% +discuss you know just basic framework +for how do we think about entry and exit + + align:start position:0% +for how do we think about entry and exit + + + align:start position:0% +for how do we think about entry and exit +in a way that would explain what all + + align:start position:0% +in a way that would explain what all + + + align:start position:0% +in a way that would explain what all +what's going on in the census data when + + align:start position:0% +what's going on in the census data when + + + align:start position:0% +what's going on in the census data when +all these new firms are coming in all + + align:start position:0% +all these new firms are coming in all + + + align:start position:0% +all these new firms are coming in all +these firms are EX visiting and and + + align:start position:0% +these firms are EX visiting and and + + + align:start position:0% +these firms are EX visiting and and +growth patterns and so on + + align:start position:0% +growth patterns and so on + + + align:start position:0% +growth patterns and so on +um so this is you know classic Model + + align:start position:0% +um so this is you know classic Model + + + align:start position:0% +um so this is you know classic Model +javanovich it's a macro is paper so + + align:start position:0% +javanovich it's a macro is paper so + + + align:start position:0% +javanovich it's a macro is paper so +there's a lot of this assuming Continuum + + align:start position:0% +there's a lot of this assuming Continuum + + + align:start position:0% +there's a lot of this assuming Continuum +of firms and whatever and assuming that + + align:start position:0% +of firms and whatever and assuming that + + + align:start position:0% +of firms and whatever and assuming that +everything works out evenly but all so + + align:start position:0% +everything works out evenly but all so + + + align:start position:0% +everything works out evenly but all so +looks a little different from IO but I I + + align:start position:0% +looks a little different from IO but I I + + + align:start position:0% +looks a little different from IO but I I +wanted to cover it so uh so we start in + + align:start position:0% +wanted to cover it so uh so we start in + + + align:start position:0% +wanted to cover it so uh so we start in +this model imagine we have a Continuum + + align:start position:0% +this model imagine we have a Continuum + + + align:start position:0% +this model imagine we have a Continuum +of small potential entrance that are out + + align:start position:0% +of small potential entrance that are out + + + align:start position:0% +of small potential entrance that are out +there and the these firms are going to + + align:start position:0% +there and the these firms are going to + + + align:start position:0% +there and the these firms are going to +have some fixed cost K of entering the + + align:start position:0% +have some fixed cost K of entering the + + + align:start position:0% +have some fixed cost K of entering the +industry and then if they enter the + + align:start position:0% +industry and then if they enter the + + + align:start position:0% +industry and then if they enter the +industry and then they decide to leave + + align:start position:0% +industry and then they decide to leave + + + align:start position:0% +industry and then they decide to leave +they're going to have some liquidation + + align:start position:0% +they're going to have some liquidation + + + align:start position:0% +they're going to have some liquidation +value W that's less than K so you're a + + align:start position:0% +value W that's less than K so you're a + + + align:start position:0% +value W that's less than K so you're a +restaurant you enter you pay K to set up + + align:start position:0% +restaurant you enter you pay K to set up + + + align:start position:0% +restaurant you enter you pay K to set up +your restaurant when you're done you + + align:start position:0% +your restaurant when you're done you + + + align:start position:0% +your restaurant when you're done you +know you can uh sell all your tables and + + align:start position:0% +know you can uh sell all your tables and + + + align:start position:0% +know you can uh sell all your tables and +your cooking equipment and the leases + + align:start position:0% +your cooking equipment and the leases + + + align:start position:0% +your cooking equipment and the leases +and whatever all the money you spent on + + align:start position:0% +and whatever all the money you spent on + + + align:start position:0% +and whatever all the money you spent on +advertising and other things that's sunk + + align:start position:0% +advertising and other things that's sunk + + + align:start position:0% +advertising and other things that's sunk +but there's some fraction of you know + + align:start position:0% +but there's some fraction of you know + + + align:start position:0% +but there's some fraction of you know +there's some amount W that you can get + + align:start position:0% +there's some amount W that you can get + + + align:start position:0% +there's some amount W that you can get +back when you close up + + align:start position:0% +back when you close up + + + align:start position:0% +back when you close up +okay uh janov assume that these firms + + align:start position:0% +okay uh janov assume that these firms + + + align:start position:0% +okay uh janov assume that these firms +have unknown types Theta I you can think + + align:start position:0% +have unknown types Theta I you can think + + + align:start position:0% +have unknown types Theta I you can think +of theta I as well it's it's like the + + align:start position:0% +of theta I as well it's it's like the + + + align:start position:0% +of theta I as well it's it's like the +inverse of their + + align:start position:0% +inverse of their + + + align:start position:0% +inverse of their +productivity um so Theta I is + + align:start position:0% +productivity um so Theta I is + + + align:start position:0% +productivity um so Theta I is +distributed normal zero um Sigma Theta + + align:start position:0% +distributed normal zero um Sigma Theta + + + align:start position:0% +distributed normal zero um Sigma Theta +squared this is like how good of a firm + + align:start position:0% +squared this is like how good of a firm + + + align:start position:0% +squared this is like how good of a firm +you are you could think of it as like in + + align:start position:0% +you are you could think of it as like in + + + align:start position:0% +you are you could think of it as like in +the restaurant + + align:start position:0% +the restaurant + + + align:start position:0% +the restaurant +case everybody thinks they have a have + + align:start position:0% +case everybody thinks they have a have + + + align:start position:0% +case everybody thinks they have a have +have food that people are going to like + + align:start position:0% +have food that people are going to like + + + align:start position:0% +have food that people are going to like +the taste of but you never know until + + align:start position:0% +the taste of but you never know until + + + align:start position:0% +the taste of but you never know until +you open your restaurant you see how + + align:start position:0% +you open your restaurant you see how + + + align:start position:0% +you open your restaurant you see how +popular it is so all these firms they + + align:start position:0% +popular it is so all these firms they + + + align:start position:0% +popular it is so all these firms they +all have some prior well in fact they + + align:start position:0% +all have some prior well in fact they + + + align:start position:0% +all have some prior well in fact they +all have in this model they all have + + align:start position:0% +all have in this model they all have + + + align:start position:0% +all have in this model they all have +exactly the same prior they all have the + + align:start position:0% +exactly the same prior they all have the + + + align:start position:0% +exactly the same prior they all have the +prior that my Theta I is drawn from this + + align:start position:0% +prior that my Theta I is drawn from this + + + align:start position:0% +prior that my Theta I is drawn from this +distribution but the only way to learn + + align:start position:0% +distribution but the only way to learn + + + align:start position:0% +distribution but the only way to learn +whether my Theta I is low in which I'm + + align:start position:0% +whether my Theta I is low in which I'm + + + align:start position:0% +whether my Theta I is low in which I'm +I'm going to be a very profitable firm + + align:start position:0% +I'm going to be a very profitable firm + + + align:start position:0% +I'm going to be a very profitable firm +or high in which I'm going to be a very + + align:start position:0% +or high in which I'm going to be a very + + + align:start position:0% +or high in which I'm going to be a very +unprofitable firm is to enter start + + align:start position:0% +unprofitable firm is to enter start + + + align:start position:0% +unprofitable firm is to enter start +selling some open my Restaurant start + + align:start position:0% +selling some open my Restaurant start + + + align:start position:0% +selling some open my Restaurant start +selling to customers see if people come + + align:start position:0% +selling to customers see if people come + + + align:start position:0% +selling to customers see if people come +and are willing to pay my prices and I I + + align:start position:0% +and are willing to pay my prices and I I + + + align:start position:0% +and are willing to pay my prices and I I +sell out or + + align:start position:0% +sell out or + + + align:start position:0% +sell out or +not so um he does this with the sort of + + align:start position:0% +not so um he does this with the sort of + + + align:start position:0% +not so um he does this with the sort of +thetas rather than like quality of the + + align:start position:0% +thetas rather than like quality of the + + + align:start position:0% +thetas rather than like quality of the +food he does this by your cost of + + align:start position:0% +food he does this by your cost of + + + align:start position:0% +food he does this by your cost of +producing as if it's your you know + + align:start position:0% +producing as if it's your you know + + + align:start position:0% +producing as if it's your you know +everyone's trying to come in they're all + + align:start position:0% +everyone's trying to come in they're all + + + align:start position:0% +everyone's trying to come in they're all +going to try to produce um you know some + + align:start position:0% +going to try to produce um you know some + + + align:start position:0% +going to try to produce um you know some +kind of Steel and then some of them end + + align:start position:0% +kind of Steel and then some of them end + + + align:start position:0% +kind of Steel and then some of them end +up being high cost producers some end up + + align:start position:0% +up being high cost producers some end up + + + align:start position:0% +up being high cost producers some end up +being lowc cost producers and and they + + align:start position:0% +being lowc cost producers and and they + + + align:start position:0% +being lowc cost producers and and they +that that's what determines their + + align:start position:0% +that that's what determines their + + + align:start position:0% +that that's what determines their +profitability so fiz period T costs + + align:start position:0% +profitability so fiz period T costs + + + align:start position:0% +profitability so fiz period T costs +there's this some common function C of + + align:start position:0% +there's this some common function C of + + + align:start position:0% +there's this some common function C of +Qi that applies to + + align:start position:0% +Qi that applies to + + + align:start position:0% +Qi that applies to +everyone but then it's multiplied by F + + align:start position:0% +everyone but then it's multiplied by F + + + align:start position:0% +everyone but then it's multiplied by F +of thet I plus Epsilon i t where Theta I + + align:start position:0% +of thet I plus Epsilon i t where Theta I + + + align:start position:0% +of thet I plus Epsilon i t where Theta I +is your permanent type and Epsilon i t + + align:start position:0% +is your permanent type and Epsilon i t + + + align:start position:0% +is your permanent type and Epsilon i t +is a + + align:start position:0% +is a + + + align:start position:0% +is a +shock um and what he's imagining is + + align:start position:0% +shock um and what he's imagining is + + + align:start position:0% +shock um and what he's imagining is +that F might be some function that looks + + align:start position:0% +that F might be some function that looks + + + align:start position:0% +that F might be some function that looks +like this + + align:start position:0% + + + + align:start position:0% + +um um + + align:start position:0% + + + + align:start position:0% + +so we make this + + align:start position:0% +so we make this + + + align:start position:0% +so we make this +one so if my type is exactly zero then + + align:start position:0% +one so if my type is exactly zero then + + + align:start position:0% +one so if my type is exactly zero then +uh or when I make this + + align:start position:0% + + + + align:start position:0% + +uh there are extra parameters in this + + align:start position:0% +uh there are extra parameters in this + + + align:start position:0% +uh there are extra parameters in this +model that probably shouldn't be there + + align:start position:0% +model that probably shouldn't be there + + + align:start position:0% +model that probably shouldn't be there +so um let's call this theta0 so if my + + align:start position:0% +so um let's call this theta0 so if my + + + align:start position:0% +so um let's call this theta0 so if my +type is exactly Theta 0 + + align:start position:0% +type is exactly Theta 0 + + + align:start position:0% +type is exactly Theta 0 +um my cost is C of + + align:start position:0% +um my cost is C of + + + align:start position:0% +um my cost is C of +Q uh if my Theta is like negative + + align:start position:0% +Q uh if my Theta is like negative + + + align:start position:0% +Q uh if my Theta is like negative +Infinity then my cost is like 12 C of Q + + align:start position:0% +Infinity then my cost is like 12 C of Q + + + align:start position:0% +Infinity then my cost is like 12 C of Q +and if my Theta is like positive + + align:start position:0% +and if my Theta is like positive + + + align:start position:0% +and if my Theta is like positive +Infinity um so I'm graphing f ofx um + + align:start position:0% +Infinity um so I'm graphing f ofx um + + + align:start position:0% +Infinity um so I'm graphing f ofx um +maybe my cost is twice C of Q and so + + align:start position:0% +maybe my cost is twice C of Q and so + + + align:start position:0% +maybe my cost is twice C of Q and so +with these firms are entering if their + + align:start position:0% +with these firms are entering if their + + + align:start position:0% +with these firms are entering if their +costs are low they're going to earn + + align:start position:0% +costs are low they're going to earn + + + align:start position:0% +costs are low they're going to earn +positive profits High profits if their + + align:start position:0% +positive profits High profits if their + + + align:start position:0% +positive profits High profits if their +costs are high they're going to earn + + align:start position:0% +costs are high they're going to earn + + + align:start position:0% +costs are high they're going to earn +negative + + align:start position:0% +negative + + + align:start position:0% +negative +profits but he adds this random shock in + + align:start position:0% +profits but he adds this random shock in + + + align:start position:0% +profits but he adds this random shock in +you know so there's this random period + + align:start position:0% +you know so there's this random period + + + align:start position:0% +you know so there's this random period +by period shock so I enter I try to + + align:start position:0% +by period shock so I enter I try to + + + align:start position:0% +by period shock so I enter I try to +produce this period I turned out that I + + align:start position:0% +produce this period I turned out that I + + + align:start position:0% +produce this period I turned out that I +had high costs I don't know am I a high + + align:start position:0% +had high costs I don't know am I a high + + + align:start position:0% +had high costs I don't know am I a high +Theta type or was I just unlucky so + + align:start position:0% +Theta type or was I just unlucky so + + + align:start position:0% +Theta type or was I just unlucky so +again if you think about on the on the + + align:start position:0% +again if you think about on the on the + + + align:start position:0% +again if you think about on the on the +quality side you know I enter enter I + + align:start position:0% +quality side you know I enter enter I + + + align:start position:0% +quality side you know I enter enter I +start selling either this there's nobody + + align:start position:0% +start selling either this there's nobody + + + align:start position:0% +start selling either this there's nobody +at my restaurant is it that my quality + + align:start position:0% +at my restaurant is it that my quality + + + align:start position:0% +at my restaurant is it that my quality +is low or did I just have a bad shock + + align:start position:0% +is low or did I just have a bad shock + + + align:start position:0% +is low or did I just have a bad shock +that a bad random draw that week + + align:start position:0% +that a bad random draw that week + + + align:start position:0% +that a bad random draw that week +okay and so firms you know are symmet + + align:start position:0% +okay and so firms you know are symmet + + + align:start position:0% +okay and so firms you know are symmet +are you know it's symmetric information + + align:start position:0% +are you know it's symmetric information + + + align:start position:0% +are you know it's symmetric information +model firms don't know their types but + + align:start position:0% +model firms don't know their types but + + + align:start position:0% +model firms don't know their types but +every time they produce they get a + + align:start position:0% +every time they produce they get a + + + align:start position:0% +every time they produce they get a +signal about what their type is they + + align:start position:0% +signal about what their type is they + + + align:start position:0% +signal about what their type is they +update their beliefs and then by + + align:start position:0% +update their beliefs and then by + + + align:start position:0% +update their beliefs and then by +updating their beliefs you know they're + + align:start position:0% +updating their beliefs you know they're + + + align:start position:0% +updating their beliefs you know they're +going to sort of uh they're going to + + align:start position:0% +going to sort of uh they're going to + + + align:start position:0% +going to sort of uh they're going to +change two things um you know C is + + align:start position:0% +change two things um you know C is + + + align:start position:0% +change two things um you know C is +convex in this + + align:start position:0% +convex in this + + + align:start position:0% +convex in this +model so if I think my cost is low I'm + + align:start position:0% +model so if I think my cost is low I'm + + + align:start position:0% +model so if I think my cost is low I'm +going to produce a lot and continue + + align:start position:0% +going to produce a lot and continue + + + align:start position:0% +going to produce a lot and continue +going because I'm like I can produce a + + align:start position:0% +going because I'm like I can produce a + + + align:start position:0% +going because I'm like I can produce a +lot and earn positive profits at the + + align:start position:0% +lot and earn positive profits at the + + + align:start position:0% +lot and earn positive profits at the +equilibrium level P star if my cost is + + align:start position:0% +equilibrium level P star if my cost is + + + align:start position:0% +equilibrium level P star if my cost is +high I'm only going to produce a little + + align:start position:0% +high I'm only going to produce a little + + + align:start position:0% +high I'm only going to produce a little +because I want to get the signal and + + align:start position:0% +because I want to get the signal and + + + align:start position:0% +because I want to get the signal and +find out if I'm good or not but I'm only + + align:start position:0% +find out if I'm good or not but I'm only + + + align:start position:0% +find out if I'm good or not but I'm only +going to produce a little bit because + + align:start position:0% +going to produce a little bit because + + + align:start position:0% +going to produce a little bit because +I'm probably going to lose money on + + align:start position:0% +I'm probably going to lose money on + + + align:start position:0% +I'm probably going to lose money on +everything I produce + + align:start position:0% +everything I produce + + + align:start position:0% +everything I produce +okay so anyway he treats the entrance as + + align:start position:0% +okay so anyway he treats the entrance as + + + align:start position:0% +okay so anyway he treats the entrance as +a continuum per period And so with this + + align:start position:0% +a continuum per period And so with this + + + align:start position:0% +a continuum per period And so with this +Continuum of + + align:start position:0% +Continuum of + + + align:start position:0% +Continuum of +entrance you get a deterministic price + + align:start position:0% +entrance you get a deterministic price + + + align:start position:0% +entrance you get a deterministic price +sequence P1 P2 P3 and he also assumes + + align:start position:0% +sequence P1 P2 P3 and he also assumes + + + align:start position:0% +sequence P1 P2 P3 and he also assumes +that the firms are all price takers and + + align:start position:0% +that the firms are all price takers and + + + align:start position:0% +that the firms are all price takers and +they're just choosing Q to maximize the + + align:start position:0% +they're just choosing Q to maximize the + + + align:start position:0% +they're just choosing Q to maximize the +expectation over Theta I of the profits + + align:start position:0% +expectation over Theta I of the profits + + + align:start position:0% +expectation over Theta I of the profits +I'm going to get this period which is PT + + align:start position:0% +I'm going to get this period which is PT + + + align:start position:0% +I'm going to get this period which is PT +which I know times Q minus my cost of + + align:start position:0% +which I know times Q minus my cost of + + + align:start position:0% +which I know times Q minus my cost of +production C of Q F of theta I plus + + align:start position:0% +production C of Q F of theta I plus + + + align:start position:0% +production C of Q F of theta I plus +Epsilon i t and again there's + + align:start position:0% +Epsilon i t and again there's + + + align:start position:0% +Epsilon i t and again there's +expectation here because I don't know + + align:start position:0% +expectation here because I don't know + + + align:start position:0% +expectation here because I don't know +Theta I and actually also there's going + + align:start position:0% +Theta I and actually also there's going + + + align:start position:0% +Theta I and actually also there's going +to be an Epsilon I is also going to be + + align:start position:0% +to be an Epsilon I is also going to be + + + align:start position:0% +to be an Epsilon I is also going to be +random shock so I guess this really + + align:start position:0% +random shock so I guess this really + + + align:start position:0% +random shock so I guess this really +should be expectation over Theta I and + + align:start position:0% +should be expectation over Theta I and + + + align:start position:0% +should be expectation over Theta I and +Epsilon + + align:start position:0% + + + + align:start position:0% + +it okay so then + + align:start position:0% +it okay so then + + + align:start position:0% +it okay so then +um what's the optimal behavior for a + + align:start position:0% +um what's the optimal behavior for a + + + align:start position:0% +um what's the optimal behavior for a +firm um you know suppose that you think + + align:start position:0% +firm um you know suppose that you think + + + align:start position:0% +firm um you know suppose that you think +Theta is very low if you think Theta is + + align:start position:0% +Theta is very low if you think Theta is + + + align:start position:0% +Theta is very low if you think Theta is +very low then you think your costs are + + align:start position:0% +very low then you think your costs are + + + align:start position:0% +very low then you think your costs are +going to be very low you know that the + + align:start position:0% +going to be very low you know that the + + + align:start position:0% +going to be very low you know that the +prices are so you produce a very high + + align:start position:0% +prices are so you produce a very high + + + align:start position:0% +prices are so you produce a very high +quantity because you can produce a very + + align:start position:0% +quantity because you can produce a very + + + align:start position:0% +quantity because you can produce a very +high quantity with the increasing costs + + align:start position:0% +high quantity with the increasing costs + + + align:start position:0% +high quantity with the increasing costs +and still make a profit right so this is + + align:start position:0% +and still make a profit right so this is + + + align:start position:0% +and still make a profit right so this is +not a constant marginal cost model this + + align:start position:0% +not a constant marginal cost model this + + + align:start position:0% +not a constant marginal cost model this +is a marginal cost uh you know this is C + + align:start position:0% +is a marginal cost uh you know this is C + + + align:start position:0% +is a marginal cost uh you know this is C +of Q that's increasing in + + align:start position:0% +of Q that's increasing in + + + align:start position:0% +of Q that's increasing in +Q um if I have a + + align:start position:0% +Q um if I have a + + + align:start position:0% +Q um if I have a +medium uh expectation of theta then I'm + + align:start position:0% +medium uh expectation of theta then I'm + + + align:start position:0% +medium uh expectation of theta then I'm +going to produce some low quantity I'm + + align:start position:0% +going to produce some low quantity I'm + + + align:start position:0% +going to produce some low quantity I'm +going going to hope that I'm I'm better + + align:start position:0% +going going to hope that I'm I'm better + + + align:start position:0% +going going to hope that I'm I'm better +than I think I am but I'm just going to + + align:start position:0% +than I think I am but I'm just going to + + + align:start position:0% +than I think I am but I'm just going to +produce the units I can produce cheaply + + align:start position:0% +produce the units I can produce cheaply + + + align:start position:0% +produce the units I can produce cheaply +uh produce my initial cheap units and + + align:start position:0% +uh produce my initial cheap units and + + + align:start position:0% +uh produce my initial cheap units and +then leave it at that and then hope that + + align:start position:0% +then leave it at that and then hope that + + + align:start position:0% +then leave it at that and then hope that +I find out I'm better but at least make + + align:start position:0% +I find out I'm better but at least make + + + align:start position:0% +I find out I'm better but at least make +a profit on the ones I + + align:start position:0% +a profit on the ones I + + + align:start position:0% +a profit on the ones I +produce um if I have a high + + align:start position:0% +produce um if I have a high + + + align:start position:0% +produce um if I have a high +Theta uh if I have a high expectation of + + align:start position:0% +Theta uh if I have a high expectation of + + + align:start position:0% +Theta uh if I have a high expectation of +theta I think I'm a bad firm uh but I'm + + align:start position:0% +theta I think I'm a bad firm uh but I'm + + + align:start position:0% +theta I think I'm a bad firm uh but I'm +uncertain about how how bad I am then + + align:start position:0% +uncertain about how how bad I am then + + + align:start position:0% +uncertain about how how bad I am then +I'm going to produce a low qit and stay + + align:start position:0% +I'm going to produce a low qit and stay + + + align:start position:0% +I'm going to produce a low qit and stay +in the market and I'm just going to + + align:start position:0% +in the market and I'm just going to + + + align:start position:0% +in the market and I'm just going to +produce these very few units and sell + + align:start position:0% +produce these very few units and sell + + + align:start position:0% +produce these very few units and sell +try to sell those and hope that I'm + + align:start position:0% +try to sell those and hope that I'm + + + align:start position:0% +try to sell those and hope that I'm +better than I think I am uh but if I'm + + align:start position:0% +better than I think I am uh but if I'm + + + align:start position:0% +better than I think I am uh but if I'm +high uh Theta and I'm have low + + align:start position:0% +high uh Theta and I'm have low + + + align:start position:0% +high uh Theta and I'm have low +uncertainty then I'm just going to take + + align:start position:0% +uncertainty then I'm just going to take + + + align:start position:0% +uncertainty then I'm just going to take +the liquidation value W and get out of + + align:start position:0% +the liquidation value W and get out of + + + align:start position:0% +the liquidation value W and get out of +the + + align:start position:0% +the + + + align:start position:0% +the +market okay so firms are making this uh + + align:start position:0% +market okay so firms are making this uh + + + align:start position:0% +market okay so firms are making this uh +you know endogenously choosing both what + + align:start position:0% +you know endogenously choosing both what + + + align:start position:0% +you know endogenously choosing both what +quantity do I produce and um what qu do + + align:start position:0% +quantity do I produce and um what qu do + + + align:start position:0% +quantity do I produce and um what qu do +I produce and do I exit or not um and + + align:start position:0% +I produce and do I exit or not um and + + + align:start position:0% +I produce and do I exit or not um and +and you know he separates these things + + align:start position:0% +and you know he separates these things + + + align:start position:0% +and you know he separates these things +so the amount I learn doesn't depend on + + align:start position:0% +so the amount I learn doesn't depend on + + + align:start position:0% +so the amount I learn doesn't depend on +the amount that I produced and so if I + + align:start position:0% +the amount that I produced and so if I + + + align:start position:0% +the amount that I produced and so if I +produce I'm going to produce the sort of + + align:start position:0% +produce I'm going to produce the sort of + + + align:start position:0% +produce I'm going to produce the sort of +static optimal + + align:start position:0% + + + + align:start position:0% + +quantity yes so someone's like believe + + align:start position:0% +quantity yes so someone's like believe + + + align:start position:0% +quantity yes so someone's like believe +their expectation data I just based on + + align:start position:0% +their expectation data I just based on + + + align:start position:0% +their expectation data I just based on +their previous observations of Thea it's + + align:start position:0% +their previous observations of Thea it's + + + align:start position:0% +their previous observations of Thea it's +based on their previous obser like every + + align:start position:0% +based on their previous obser like every + + + align:start position:0% +based on their previous obser like every +period you get an observation of theta I + + align:start position:0% +period you get an observation of theta I + + + align:start position:0% +period you get an observation of theta I +plus Epsilon it and so you have a you + + align:start position:0% +plus Epsilon it and so you have a you + + + align:start position:0% +plus Epsilon it and so you have a you +have a you it's a normal learning model + + align:start position:0% +have a you it's a normal learning model + + + align:start position:0% +have a you it's a normal learning model +I have a prior that it's normal zero + + align:start position:0% +I have a prior that it's normal zero + + + align:start position:0% +I have a prior that it's normal zero +Theta these epsilons are also normal so + + align:start position:0% +Theta these epsilons are also normal so + + + align:start position:0% +Theta these epsilons are also normal so +every time I enter I get a normal signal + + align:start position:0% +every time I enter I get a normal signal + + + align:start position:0% +every time I enter I get a normal signal +and then I just beige and update up and + + align:start position:0% +and then I just beige and update up and + + + align:start position:0% +and then I just beige and update up and +down and the number of signals that I + + align:start position:0% +down and the number of signals that I + + + align:start position:0% +down and the number of signals that I +get determines whether my posterior is + + align:start position:0% +get determines whether my posterior is + + + align:start position:0% +get determines whether my posterior is +diffuse or narrow or + + align:start position:0% +diffuse or narrow or + + + align:start position:0% +diffuse or narrow or +tight right so some sense the older I am + + align:start position:0% +tight right so some sense the older I am + + + align:start position:0% +tight right so some sense the older I am +the less uncertainty I have in like in + + align:start position:0% +the less uncertainty I have in like in + + + align:start position:0% +the less uncertainty I have in like in +nor with normal distributions it's just + + align:start position:0% +nor with normal distributions it's just + + + align:start position:0% +nor with normal distributions it's just +a purely one over + + align:start position:0% +a purely one over + + + align:start position:0% +a purely one over +n uncertainty diminishes like one over + + align:start position:0% +n uncertainty diminishes like one over + + + align:start position:0% +n uncertainty diminishes like one over +an like Get N observations + + align:start position:0% + + + + align:start position:0% + +okay uh and so you know what he notes + + align:start position:0% +okay uh and so you know what he notes + + + align:start position:0% +okay uh and so you know what he notes +that a basic model like this uh makes a + + align:start position:0% +that a basic model like this uh makes a + + + align:start position:0% +that a basic model like this uh makes a +number of predictions about firm + + align:start position:0% +number of predictions about firm + + + align:start position:0% +number of predictions about firm +dynamics that seem to fit with what the + + align:start position:0% +dynamics that seem to fit with what the + + + align:start position:0% +dynamics that seem to fit with what the +basic census data on firm Dynamics look + + align:start position:0% +basic census data on firm Dynamics look + + + align:start position:0% +basic census data on firm Dynamics look +like so some + + align:start position:0% +like so some + + + align:start position:0% +like so some +observations um small firms grow faster + + align:start position:0% +observations um small firms grow faster + + + align:start position:0% +observations um small firms grow faster +and fail more often um why is that well + + align:start position:0% +and fail more often um why is that well + + + align:start position:0% +and fail more often um why is that well +a lot of the small firms are um you + + align:start position:0% +a lot of the small firms are um you + + + align:start position:0% +a lot of the small firms are um you +know a lot of the small firms are these + + align:start position:0% +know a lot of the small firms are these + + + align:start position:0% +know a lot of the small firms are these +people with high + + align:start position:0% +people with high + + + align:start position:0% +people with high +uncertainty right the small firms are + + align:start position:0% +uncertainty right the small firms are + + + align:start position:0% +uncertainty right the small firms are +new firms that come in or firms that + + align:start position:0% +new firms that come in or firms that + + + align:start position:0% +new firms that come in or firms that +have come in and gotten one bad + + align:start position:0% +have come in and gotten one bad + + + align:start position:0% +have come in and gotten one bad +draw they think their Theta is high but + + align:start position:0% +draw they think their Theta is high but + + + align:start position:0% +draw they think their Theta is high but +they're very uncertain about their Theta + + align:start position:0% +they're very uncertain about their Theta + + + align:start position:0% +they're very uncertain about their Theta +so they're producing small quantities if + + align:start position:0% +so they're producing small quantities if + + + align:start position:0% +so they're producing small quantities if +they find out that they're better firms + + align:start position:0% +they find out that they're better firms + + + align:start position:0% +they find out that they're better firms +they grow very + + align:start position:0% +they grow very + + + align:start position:0% +they grow very +quickly okay these guys the only way you + + align:start position:0% +quickly okay these guys the only way you + + + align:start position:0% +quickly okay these guys the only way you +can have a low expectation of theta is + + align:start position:0% +can have a low expectation of theta is + + + align:start position:0% +can have a low expectation of theta is +if you've gotten a lot of data and all + + align:start position:0% +if you've gotten a lot of data and all + + + align:start position:0% +if you've gotten a lot of data and all +the data says that your quantity is low + + align:start position:0% +the data says that your quantity is low + + + align:start position:0% +the data says that your quantity is low +your your costs are low therefore you're + + align:start position:0% +your your costs are low therefore you're + + + align:start position:0% +your your costs are low therefore you're +not going to grow very fast because + + align:start position:0% +not going to grow very fast because + + + align:start position:0% +not going to grow very fast because +you've already got a lot of data you're + + align:start position:0% +you've already got a lot of data you're + + + align:start position:0% +you've already got a lot of data you're +going to continue to think that your + + align:start position:0% +going to continue to think that your + + + align:start position:0% +going to continue to think that your +costs are low and you're going to sort + + align:start position:0% +costs are low and you're going to sort + + + align:start position:0% +costs are low and you're going to sort +of have roughly the same output but so + + align:start position:0% +of have roughly the same output but so + + + align:start position:0% +of have roughly the same output but so +this sort of small firms small firms are + + align:start position:0% +this sort of small firms small firms are + + + align:start position:0% +this sort of small firms small firms are +firms who have a lot of uncertainty but + + align:start position:0% +firms who have a lot of uncertainty but + + + align:start position:0% +firms who have a lot of uncertainty but +think their costs are relatively High + + align:start position:0% +think their costs are relatively High + + + align:start position:0% +think their costs are relatively High +therefore they grow fast if they stay in + + align:start position:0% +therefore they grow fast if they stay in + + + align:start position:0% +therefore they grow fast if they stay in +the market but they also just exit and + + align:start position:0% +the market but they also just exit and + + + align:start position:0% +the market but they also just exit and +fail fail much more + + align:start position:0% +fail fail much more + + + align:start position:0% +fail fail much more +often okay + + align:start position:0% +often okay + + + align:start position:0% +often okay +um bigger firms have higher profits so + + align:start position:0% +um bigger firms have higher profits so + + + align:start position:0% +um bigger firms have higher profits so +you know profits are quite different + + align:start position:0% +you know profits are quite different + + + align:start position:0% +you know profits are quite different +across firms the high-profit firms are + + align:start position:0% +across firms the high-profit firms are + + + align:start position:0% +across firms the high-profit firms are +the people who've been around for a + + align:start position:0% +the people who've been around for a + + + align:start position:0% +the people who've been around for a +while they've learned that their Theta + + align:start position:0% +while they've learned that their Theta + + + align:start position:0% +while they've learned that their Theta +is very low therefore they can produce + + align:start position:0% +is very low therefore they can produce + + + align:start position:0% +is very low therefore they can produce +way out here on their cost curve and + + align:start position:0% +way out here on their cost curve and + + + align:start position:0% +way out here on their cost curve and +still make a profit and they're making + + align:start position:0% +still make a profit and they're making + + + align:start position:0% +still make a profit and they're making +all these profits on the infam marginal + + align:start position:0% +all these profits on the infam marginal + + + align:start position:0% +all these profits on the infam marginal +units so the big firms are the big firms + + align:start position:0% +units so the big firms are the big firms + + + align:start position:0% +units so the big firms are the big firms +are the profitable firms um and they're + + align:start position:0% +are the profitable firms um and they're + + + align:start position:0% +are the profitable firms um and they're +profitable because they just are more + + align:start position:0% +profitable because they just are more + + + align:start position:0% +profitable because they just are more +efficient cost-wise than the other + + align:start position:0% +efficient cost-wise than the other + + + align:start position:0% +efficient cost-wise than the other +firms + + align:start position:0% +firms + + + align:start position:0% +firms +um if you think about you know is + + align:start position:0% +um if you think about you know is + + + align:start position:0% +um if you think about you know is +um how are industry concentration and + + align:start position:0% +um how are industry concentration and + + + align:start position:0% +um how are industry concentration and +profits related you know and right we + + align:start position:0% +profits related you know and right we + + + align:start position:0% +profits related you know and right we +have the sort of standard view that + + align:start position:0% +have the sort of standard view that + + + align:start position:0% +have the sort of standard view that +industry concentration profits are + + align:start position:0% +industry concentration profits are + + + align:start position:0% +industry concentration profits are +related because we put more firms into a + + align:start position:0% +related because we put more firms into a + + + align:start position:0% +related because we put more firms into a +Coro model or more firms into a a + + align:start position:0% +Coro model or more firms into a a + + + align:start position:0% +Coro model or more firms into a a +hoteling circle model markups + + align:start position:0% +hoteling circle model markups + + + align:start position:0% +hoteling circle model markups +drop um here um you know this is like + + align:start position:0% +drop um here um you know this is like + + + align:start position:0% +drop um here um you know this is like +this is a you know this is like a a + + align:start position:0% +this is a you know this is like a a + + + align:start position:0% +this is a you know this is like a a +perfect competition model it's but in + + align:start position:0% +perfect competition model it's but in + + + align:start position:0% +perfect competition model it's but in +equilibrium industry concentration is + + align:start position:0% +equilibrium industry concentration is + + + align:start position:0% +equilibrium industry concentration is +correlated in the cross section with + + align:start position:0% +correlated in the cross section with + + + align:start position:0% +correlated in the cross section with +high profits because an industry that + + align:start position:0% +high profits because an industry that + + + align:start position:0% +high profits because an industry that +happens to have a few very lowcost firms + + align:start position:0% +happens to have a few very lowcost firms + + + align:start position:0% +happens to have a few very lowcost firms +in it those firms will earn very high + + align:start position:0% +in it those firms will earn very high + + + align:start position:0% +in it those firms will earn very high +profits whereas if another industry all + + align:start position:0% +profits whereas if another industry all + + + align:start position:0% +profits whereas if another industry all +the firms have very similar costs then + + align:start position:0% +the firms have very similar costs then + + + align:start position:0% +the firms have very similar costs then +you're just going to have a large number + + align:start position:0% +you're just going to have a large number + + + align:start position:0% +you're just going to have a large number +of firms each earning individually low + + align:start position:0% +of firms each earning individually low + + + align:start position:0% +of firms each earning individually low +profits and so the firms that are going + + align:start position:0% +profits and so the firms that are going + + + align:start position:0% +profits and so the firms that are going +to look like the high profit Industries + + align:start position:0% +to look like the high profit Industries + + + align:start position:0% +to look like the high profit Industries +they're concentrated because they're the + + align:start position:0% +they're concentrated because they're the + + + align:start position:0% +they're concentrated because they're the +firms that just have a few firms that + + align:start position:0% +firms that just have a few firms that + + + align:start position:0% +firms that just have a few firms that +have Theta draws much lower than + + align:start position:0% +have Theta draws much lower than + + + align:start position:0% +have Theta draws much lower than +everybody else's Theta draw and so you + + align:start position:0% +everybody else's Theta draw and so you + + + align:start position:0% +everybody else's Theta draw and so you +get this correlation between profits and + + align:start position:0% +get this correlation between profits and + + + align:start position:0% +get this correlation between profits and +concentration that comes from the + + align:start position:0% +concentration that comes from the + + + align:start position:0% +concentration that comes from the +distribution of realized + + align:start position:0% +distribution of realized + + + align:start position:0% +distribution of realized +costs okay so we get a profit + + align:start position:0% +costs okay so we get a profit + + + align:start position:0% +costs okay so we get a profit +concentration cross-section but it's + + align:start position:0% +concentration cross-section but it's + + + align:start position:0% +concentration cross-section but it's +caused by a correlation with the omitted + + align:start position:0% +caused by a correlation with the omitted + + + align:start position:0% +caused by a correlation with the omitted +variable of distribution of firm costs + + align:start position:0% +variable of distribution of firm costs + + + align:start position:0% +variable of distribution of firm costs +rather than caused by competition of + + align:start position:0% +rather than caused by competition of + + + align:start position:0% +rather than caused by competition of +cost caal + + align:start position:0% + + + + align:start position:0% + +effect + + align:start position:0% +effect + + + align:start position:0% +effect +um industry concentration is also + + align:start position:0% +um industry concentration is also + + + align:start position:0% +um industry concentration is also +correlated with cross-sectional variance + + align:start position:0% +correlated with cross-sectional variance + + + align:start position:0% +correlated with cross-sectional variance +and profits so again if you have a + + align:start position:0% +and profits so again if you have a + + + align:start position:0% +and profits so again if you have a +industry that has if I do histograms of + + align:start position:0% +industry that has if I do histograms of + + + align:start position:0% +industry that has if I do histograms of +costs if I have a an industry that has + + align:start position:0% +costs if I have a an industry that has + + + align:start position:0% +costs if I have a an industry that has +like a mass of firms that have very low + + align:start position:0% +like a mass of firms that have very low + + + align:start position:0% +like a mass of firms that have very low +costs and then some firms that have + + align:start position:0% +costs and then some firms that have + + + align:start position:0% +costs and then some firms that have +higher + + align:start position:0% +higher + + + align:start position:0% +higher +costs this industry is going to end up + + align:start position:0% +costs this industry is going to end up + + + align:start position:0% +costs this industry is going to end up +very concentrated because the lowcost + + align:start position:0% +very concentrated because the lowcost + + + align:start position:0% +very concentrated because the lowcost +firms are going to produce a ton all + + align:start position:0% +firms are going to produce a ton all + + + align:start position:0% +firms are going to produce a ton all +these firms are going to produce small + + align:start position:0% +these firms are going to produce small + + + align:start position:0% +these firms are going to produce small +amounts and so we're going to see highly + + align:start position:0% +amounts and so we're going to see highly + + + align:start position:0% +amounts and so we're going to see highly +profitable firms and very non-profitable + + align:start position:0% +profitable firms and very non-profitable + + + align:start position:0% +profitable firms and very non-profitable +firms if you're going to have an + + align:start position:0% +firms if you're going to have an + + + align:start position:0% +firms if you're going to have an +industry that's not concentrated an + + align:start position:0% +industry that's not concentrated an + + + align:start position:0% +industry that's not concentrated an +industry that's not concentrated is one + + align:start position:0% +industry that's not concentrated is one + + + align:start position:0% +industry that's not concentrated is one +that + + align:start position:0% +that + + + align:start position:0% +that +has much less cost + + align:start position:0% +has much less cost + + + align:start position:0% +has much less cost +heterogenity and so if it's got much + + align:start position:0% +heterogenity and so if it's got much + + + align:start position:0% +heterogenity and so if it's got much +less cost heterogenity no one produces a + + align:start position:0% +less cost heterogenity no one produces a + + + align:start position:0% +less cost heterogenity no one produces a +large quantity and that also means that + + align:start position:0% +large quantity and that also means that + + + align:start position:0% +large quantity and that also means that +everyone's getting similar profits to + + align:start position:0% +everyone's getting similar profits to + + + align:start position:0% +everyone's getting similar profits to +everybody else because their costs are + + align:start position:0% +everybody else because their costs are + + + align:start position:0% +everybody else because their costs are +all similar to everybody else okay + + align:start position:0% +all similar to everybody else okay + + + align:start position:0% +all similar to everybody else okay +not note that like these guys are all + + align:start position:0% +not note that like these guys are all + + + align:start position:0% +not note that like these guys are all +making essentially zero profits and so + + align:start position:0% +making essentially zero profits and so + + + align:start position:0% +making essentially zero profits and so +it's sort of like small numbers and zero + + align:start position:0% +it's sort of like small numbers and zero + + + align:start position:0% +it's sort of like small numbers and zero +but small numbers and zero are not so + + align:start position:0% +but small numbers and zero are not so + + + align:start position:0% +but small numbers and zero are not so +different in this model um so anyway you + + align:start position:0% +different in this model um so anyway you + + + align:start position:0% +different in this model um so anyway you +get + + align:start position:0% +get + + + align:start position:0% +get +this concentration is both correlated + + align:start position:0% +this concentration is both correlated + + + align:start position:0% +this concentration is both correlated +with levels of profits and with + + align:start position:0% +with levels of profits and with + + + align:start position:0% +with levels of profits and with +cross-sectional variance and + + align:start position:0% +cross-sectional variance and + + + align:start position:0% +cross-sectional variance and +profits uh anyway so there's a you + + align:start position:0% + + + + align:start position:0% + +know large large literature on on the + + align:start position:0% +know large large literature on on the + + + align:start position:0% +know large large literature on on the +empirics of Entry that sort of bears out + + align:start position:0% +empirics of Entry that sort of bears out + + + align:start position:0% +empirics of Entry that sort of bears out +that many of these things seem to be + + align:start position:0% +that many of these things seem to be + + + align:start position:0% +that many of these things seem to be +true and I I guess this is sort of the + + align:start position:0% +true and I I guess this is sort of the + + + align:start position:0% +true and I I guess this is sort of the +way we often think about we make sense + + align:start position:0% +way we often think about we make sense + + + align:start position:0% +way we often think about we make sense +of that data is that it's not that all + + align:start position:0% +of that data is that it's not that all + + + align:start position:0% +of that data is that it's not that all +firms have the same technology some + + align:start position:0% +firms have the same technology some + + + align:start position:0% +firms have the same technology some +firms are just more efficient than + + align:start position:0% +firms are just more efficient than + + + align:start position:0% +firms are just more efficient than +others you know for no observable reason + + align:start position:0% +others you know for no observable reason + + + align:start position:0% +others you know for no observable reason +for no observable + + align:start position:0% + + + + align:start position:0% + +reason okay any any questions on this + + align:start position:0% +reason okay any any questions on this + + + align:start position:0% +reason okay any any questions on this +framework I think that's all I had to + + align:start position:0% +framework I think that's all I had to + + + align:start position:0% +framework I think that's all I had to +say on it um yep so you know and what I + + align:start position:0% +say on it um yep so you know and what I + + + align:start position:0% +say on it um yep so you know and what I +want to do in this lecture and I covered + + align:start position:0% +want to do in this lecture and I covered + + + align:start position:0% +want to do in this lecture and I covered +this I I don't always teach jovanovich + + align:start position:0% +this I I don't always teach jovanovich + + + align:start position:0% +this I I don't always teach jovanovich +but um I want to you know I like to sort + + align:start position:0% +but um I want to you know I like to sort + + + align:start position:0% +but um I want to you know I like to sort +of have some recent uh recent + + align:start position:0% +of have some recent uh recent + + + align:start position:0% +of have some recent uh recent +theoretical papers in the class um so + + align:start position:0% +theoretical papers in the class um so + + + align:start position:0% +theoretical papers in the class um so +anyway this this is a paper by um nikil + + align:start position:0% +anyway this this is a paper by um nikil + + + align:start position:0% +anyway this this is a paper by um nikil +V who's an assistant professor in Paris + + align:start position:0% +V who's an assistant professor in Paris + + + align:start position:0% +V who's an assistant professor in Paris +um anyway so basically what VOD has done + + align:start position:0% +um anyway so basically what VOD has done + + + align:start position:0% +um anyway so basically what VOD has done +in this paper is gone back to jovanovich + + align:start position:0% +in this paper is gone back to jovanovich + + + align:start position:0% +in this paper is gone back to jovanovich +1982 and use jovanovich 1982 to think + + align:start position:0% +1982 and use jovanovich 1982 to think + + + align:start position:0% +1982 and use jovanovich 1982 to think +about um the effects of rating + + align:start position:0% +about um the effects of rating + + + align:start position:0% +about um the effects of rating +intermediaries and what types of + + align:start position:0% +intermediaries and what types of + + + align:start position:0% +intermediaries and what types of +policies rating we we want rating + + align:start position:0% +policies rating we we want rating + + + align:start position:0% +policies rating we we want rating +intermediaries to have or what effects + + align:start position:0% +intermediaries to have or what effects + + + align:start position:0% +intermediaries to have or what effects +rating intermediaries have so the by + + align:start position:0% +rating intermediaries have so the by + + + align:start position:0% +rating intermediaries have so the by +rating intermediaries he has like um + + align:start position:0% +rating intermediaries he has like um + + + align:start position:0% +rating intermediaries he has like um +thinking about like firms like Amazon + + align:start position:0% +thinking about like firms like Amazon + + + align:start position:0% +thinking about like firms like Amazon +and Yelp where sort of like on Amazon + + align:start position:0% +and Yelp where sort of like on Amazon + + + align:start position:0% +and Yelp where sort of like on Amazon +you can leave feedback like you know + + align:start position:0% +you can leave feedback like you know + + + align:start position:0% +you can leave feedback like you know +Amazon majority of the merchandise on + + align:start position:0% +Amazon majority of the merchandise on + + + align:start position:0% +Amazon majority of the merchandise on +Amazon is not actually sold by it's not + + align:start position:0% +Amazon is not actually sold by it's not + + + align:start position:0% +Amazon is not actually sold by it's not +by Amazon itself it's sold by Third + + align:start position:0% +by Amazon itself it's sold by Third + + + align:start position:0% +by Amazon itself it's sold by Third +parties selling on Amazon Amazon you + + align:start position:0% +parties selling on Amazon Amazon you + + + align:start position:0% +parties selling on Amazon Amazon you +know there are lots of you want to buy + + align:start position:0% +know there are lots of you want to buy + + + align:start position:0% +know there are lots of you want to buy +an umbrella on Amazon you go there and + + align:start position:0% +an umbrella on Amazon you go there and + + + align:start position:0% +an umbrella on Amazon you go there and +you sort of look at the reviews of that + + align:start position:0% +you sort of look at the reviews of that + + + align:start position:0% +you sort of look at the reviews of that +umbrella and and whether people say that + + align:start position:0% +umbrella and and whether people say that + + + align:start position:0% +umbrella and and whether people say that +umbrella is good or bad and then you buy + + align:start position:0% +umbrella is good or bad and then you buy + + + align:start position:0% +umbrella is good or bad and then you buy +it or not you know you get Yelp or trip + + align:start position:0% +it or not you know you get Yelp or trip + + + align:start position:0% +it or not you know you get Yelp or trip +advisor or whomever that has lots of + + align:start position:0% +advisor or whomever that has lots of + + + align:start position:0% +advisor or whomever that has lots of +reviews of restaurants and tells you is + + align:start position:0% +reviews of restaurants and tells you is + + + align:start position:0% +reviews of restaurants and tells you is +this a good restaurant is this a bad + + align:start position:0% +this a good restaurant is this a bad + + + align:start position:0% +this a good restaurant is this a bad +restaurant consumers use that to learn + + align:start position:0% +restaurant consumers use that to learn + + + align:start position:0% +restaurant consumers use that to learn +about product + + align:start position:0% +about product + + + align:start position:0% +about product +quality + + align:start position:0% +quality + + + align:start position:0% +quality +um and so you know what there's this + + align:start position:0% +um and so you know what there's this + + + align:start position:0% +um and so you know what there's this +sort of challenge in coming up with + + align:start position:0% +sort of challenge in coming up with + + + align:start position:0% +sort of challenge in coming up with +these in in this business model is that + + align:start position:0% +these in in this business model is that + + + align:start position:0% +these in in this business model is that +um you know + + align:start position:0% +um you know + + + align:start position:0% +um you know +there are big firms that everybody buys + + align:start position:0% +there are big firms that everybody buys + + + align:start position:0% +there are big firms that everybody buys +from on the big firms everybody buys + + align:start position:0% +from on the big firms everybody buys + + + align:start position:0% +from on the big firms everybody buys +from there going to be a zillion reviews + + align:start position:0% +from there going to be a zillion reviews + + + align:start position:0% +from there going to be a zillion reviews +and people are going to be able to find + + align:start position:0% +and people are going to be able to find + + + align:start position:0% +and people are going to be able to find +out the quality of those firms but you + + align:start position:0% +out the quality of those firms but you + + + align:start position:0% +out the quality of those firms but you +have many many small entrance and many + + align:start position:0% +have many many small entrance and many + + + align:start position:0% +have many many small entrance and many +many new entrance all the time into + + align:start position:0% +many new entrance all the time into + + + align:start position:0% +many new entrance all the time into +these models and it's the new entrance + + align:start position:0% +these models and it's the new entrance + + + align:start position:0% +these models and it's the new entrance +that people really want to know about + + align:start position:0% +that people really want to know about + + + align:start position:0% +that people really want to know about +and learn about whether their quality is + + align:start position:0% +and learn about whether their quality is + + + align:start position:0% +and learn about whether their quality is +good or bad but there's this effect of + + align:start position:0% +good or bad but there's this effect of + + + align:start position:0% +good or bad but there's this effect of +if you have new firms people are + + align:start position:0% +if you have new firms people are + + + align:start position:0% +if you have new firms people are +hesitant to buy from them because + + align:start position:0% +hesitant to buy from them because + + + align:start position:0% +hesitant to buy from them because +they're new and because people are + + align:start position:0% +they're new and because people are + + + align:start position:0% +they're new and because people are +hesitant to buy from them because + + align:start position:0% +hesitant to buy from them because + + + align:start position:0% +hesitant to buy from them because +they're new there are very few reviews + + align:start position:0% +they're new there are very few reviews + + + align:start position:0% +they're new there are very few reviews +and therefore they very few reviews + + align:start position:0% +and therefore they very few reviews + + + align:start position:0% +and therefore they very few reviews +therefore people can't learn about them + + align:start position:0% +therefore people can't learn about them + + + align:start position:0% +therefore people can't learn about them +and so he wants to think about is what + + align:start position:0% +and so he wants to think about is what + + + align:start position:0% +and so he wants to think about is what +would be the optimal um design for a + + align:start position:0% +would be the optimal um design for a + + + align:start position:0% +would be the optimal um design for a +rating + + align:start position:0% +rating + + + align:start position:0% +rating +intermediary that wanted to uh you know + + align:start position:0% +intermediary that wanted to uh you know + + + align:start position:0% +intermediary that wanted to uh you know +promote an efficient level of + + align:start position:0% +promote an efficient level of + + + align:start position:0% +promote an efficient level of +competition in some sense we we think + + align:start position:0% +competition in some sense we we think + + + align:start position:0% +competition in some sense we we think +there could be you know I I why could + + align:start position:0% +there could be you know I I why could + + + align:start position:0% +there could be you know I I why could +there be too little entry in models + + align:start position:0% +there be too little entry in models + + + align:start position:0% +there be too little entry in models +there could be too little entry here + + align:start position:0% +there could be too little entry here + + + align:start position:0% +there could be too little entry here +another reason I didn't put my theory in + + align:start position:0% +another reason I didn't put my theory in + + + align:start position:0% +another reason I didn't put my theory in +my first part was there' be too little + + align:start position:0% +my first part was there' be too little + + + align:start position:0% +my first part was there' be too little +entry because people don't know the + + align:start position:0% +entry because people don't know the + + + align:start position:0% +entry because people don't know the +quality of new firms and therefore they + + align:start position:0% +quality of new firms and therefore they + + + align:start position:0% +quality of new firms and therefore they +won't buy from new firms and therefore + + align:start position:0% +won't buy from new firms and therefore + + + align:start position:0% +won't buy from new firms and therefore +no one will enter and sort of have any + + align:start position:0% +no one will enter and sort of have any + + + align:start position:0% +no one will enter and sort of have any +people learn about their quality you + + align:start position:0% +people learn about their quality you + + + align:start position:0% +people learn about their quality you +know um jovanovich it was very + + align:start position:0% +know um jovanovich it was very + + + align:start position:0% +know um jovanovich it was very +convenient that the firms could enter + + align:start position:0% +convenient that the firms could enter + + + align:start position:0% +convenient that the firms could enter +and then produce these tiny quantities + + align:start position:0% +and then produce these tiny quantities + + + align:start position:0% +and then produce these tiny quantities +and get in highly informative signals + + align:start position:0% +and get in highly informative signals + + + align:start position:0% +and get in highly informative signals +about their quality and know whether to + + align:start position:0% +about their quality and know whether to + + + align:start position:0% +about their quality and know whether to +start producing more in practice you + + align:start position:0% +start producing more in practice you + + + align:start position:0% +start producing more in practice you +know that's not something restaurants + + align:start position:0% +know that's not something restaurants + + + align:start position:0% +know that's not something restaurants +can do is come in and produce a tiny + + align:start position:0% +can do is come in and produce a tiny + + + align:start position:0% +can do is come in and produce a tiny +quantity and get a lot of reviews on + + align:start position:0% +quantity and get a lot of reviews on + + + align:start position:0% +quantity and get a lot of reviews on +Yelp + + align:start position:0% +Yelp + + + align:start position:0% +Yelp +um okay so anyway models got a Continuum + + align:start position:0% +um okay so anyway models got a Continuum + + + align:start position:0% +um okay so anyway models got a Continuum +of small potential entrance so these + + align:start position:0% +of small potential entrance so these + + + align:start position:0% +of small potential entrance so these +think of these as new restaurants or new + + align:start position:0% +think of these as new restaurants or new + + + align:start position:0% +think of these as new restaurants or new +guys just trying to sell black f holding + + align:start position:0% +guys just trying to sell black f holding + + + align:start position:0% +guys just trying to sell black f holding +umbrellas on Amazon um they have a fixed + + align:start position:0% +umbrellas on Amazon um they have a fixed + + + align:start position:0% +umbrellas on Amazon um they have a fixed +cost K of + + align:start position:0% +cost K of + + + align:start position:0% +cost K of +entering um they're going to have some + + align:start position:0% +entering um they're going to have some + + + align:start position:0% +entering um they're going to have some +flow cost of operation I didn't put a + + align:start position:0% +flow cost of operation I didn't put a + + + align:start position:0% +flow cost of operation I didn't put a +letter down here maybe this is C but + + align:start position:0% +letter down here maybe this is C but + + + align:start position:0% +letter down here maybe this is C but +every period that I'm continuing to + + align:start position:0% +every period that I'm continuing to + + + align:start position:0% +every period that I'm continuing to +operate I have to pay some flow cost um + + align:start position:0% +operate I have to pay some flow cost um + + + align:start position:0% +operate I have to pay some flow cost um +just to make the model have a steady + + align:start position:0% +just to make the model have a steady + + + align:start position:0% +just to make the model have a steady +state equilibrium he has some exogenous + + align:start position:0% +state equilibrium he has some exogenous + + + align:start position:0% +state equilibrium he has some exogenous +death rate Delta so every firm with some + + align:start position:0% +death rate Delta so every firm with some + + + align:start position:0% +death rate Delta so every firm with some +probability just disappears in each + + align:start position:0% +probability just disappears in each + + + align:start position:0% +probability just disappears in each +period um and then uh firms have some + + align:start position:0% +period um and then uh firms have some + + + align:start position:0% +period um and then uh firms have some +discount rate + + align:start position:0% +discount rate + + + align:start position:0% +discount rate +row uh in his + + align:start position:0% +row uh in his + + + align:start position:0% +row uh in his +model simplest you know simplifying the + + align:start position:0% +model simplest you know simplifying the + + + align:start position:0% +model simplest you know simplifying the +theory by assuming that it's a discrete + + align:start position:0% +theory by assuming that it's a discrete + + + align:start position:0% +theory by assuming that it's a discrete +type model all restaurants have either + + align:start position:0% +type model all restaurants have either + + + align:start position:0% +type model all restaurants have either +quality zero or quality one so it's just + + align:start position:0% +quality zero or quality one so it's just + + + align:start position:0% +quality zero or quality one so it's just +a pure bimodal + + align:start position:0% +a pure bimodal + + + align:start position:0% +a pure bimodal +distribution uh again like in jovanovich + + align:start position:0% +distribution uh again like in jovanovich + + + align:start position:0% +distribution uh again like in jovanovich +it's a symmetric information model + + align:start position:0% +it's a symmetric information model + + + align:start position:0% +it's a symmetric information model +there's prior mean P0 that the firm has + + align:start position:0% +there's prior mean P0 that the firm has + + + align:start position:0% +there's prior mean P0 that the firm has +quality one and that information is + + align:start position:0% +quality one and that information is + + + align:start position:0% +quality one and that information is +symmetric among everyone in the market + + align:start position:0% +symmetric among everyone in the market + + + align:start position:0% +symmetric among everyone in the market +no one knows but everyone knows new + + align:start position:0% +no one knows but everyone knows new + + + align:start position:0% +no one knows but everyone knows new +restaurants there's probability P0 that + + align:start position:0% +restaurants there's probability P0 that + + + align:start position:0% +restaurants there's probability P0 that +their food is good probability one minus + + align:start position:0% +their food is good probability one minus + + + align:start position:0% +their food is good probability one minus +P0 that their food is bad okay uh every + + align:start position:0% +P0 that their food is bad okay uh every + + + align:start position:0% +P0 that their food is bad okay uh every +firm has exactly one + + align:start position:0% +firm has exactly one + + + align:start position:0% +firm has exactly one +table and the firms can do is set prices + + align:start position:0% +table and the firms can do is set prices + + + align:start position:0% +table and the firms can do is set prices +um qit for their table at time + + align:start position:0% + + + + align:start position:0% + +T um what he assumes is that the you + + align:start position:0% +T um what he assumes is that the you + + + align:start position:0% +T um what he assumes is that the you +have this prior P knot and then you have + + align:start position:0% +have this prior P knot and then you have + + + align:start position:0% +have this prior P knot and then you have +a posterior every period um if somebody + + align:start position:0% +a posterior every period um if somebody + + + align:start position:0% +a posterior every period um if somebody +you know if you're + + align:start position:0% +you know if you're + + + align:start position:0% +you know if you're +operating then reviews arrive according + + align:start position:0% +operating then reviews arrive according + + + align:start position:0% +operating then reviews arrive according +to a passon process and those reviews + + align:start position:0% +to a passon process and those reviews + + + align:start position:0% +to a passon process and those reviews +are going to like make the quality the + + align:start position:0% +are going to like make the quality the + + + align:start position:0% +are going to like make the quality the +poster your quality go up or down + + align:start position:0% +poster your quality go up or down + + + align:start position:0% +poster your quality go up or down +whether it's a good review or a bad + + align:start position:0% +whether it's a good review or a bad + + + align:start position:0% +whether it's a good review or a bad +review he goes with this sort of + + align:start position:0% +review he goes with this sort of + + + align:start position:0% +review he goes with this sort of +continuous uh continuous time Brownie + + align:start position:0% +continuous uh continuous time Brownie + + + align:start position:0% +continuous uh continuous time Brownie +and motion learning process where my + + align:start position:0% +and motion learning process where my + + + align:start position:0% +and motion learning process where my +posterior pit of olves according to + + align:start position:0% +posterior pit of olves according to + + + align:start position:0% +posterior pit of olves according to +dpit + + align:start position:0% +dpit + + + align:start position:0% +dpit +equal < TK of Lambda it t pit 1us pit + + align:start position:0% +equal < TK of Lambda it t pit 1us pit + + + align:start position:0% +equal < TK of Lambda it t pit 1us pit +time DZ where zit is a brownie in motion + + align:start position:0% +time DZ where zit is a brownie in motion + + + align:start position:0% +time DZ where zit is a brownie in motion +um but you can roughly think of this as + + align:start position:0% +um but you can roughly think of this as + + + align:start position:0% +um but you can roughly think of this as +Lambda it is the review arrival rate and + + align:start position:0% +Lambda it is the review arrival rate and + + + align:start position:0% +Lambda it is the review arrival rate and +each of these is like a normal signal + + align:start position:0% +each of these is like a normal signal + + + align:start position:0% +each of these is like a normal signal +and so if it's a normal signal I'm going + + align:start position:0% +and so if it's a normal signal I'm going + + + align:start position:0% +and so if it's a normal signal I'm going +to get information that either pushes me + + align:start position:0% +to get information that either pushes me + + + align:start position:0% +to get information that either pushes me +to the right or left you know and sort + + align:start position:0% +to the right or left you know and sort + + + align:start position:0% +to the right or left you know and sort +of the uh variance of you know like + + align:start position:0% +of the uh variance of you know like + + + align:start position:0% +of the uh variance of you know like +since I have a brou quality the variance + + align:start position:0% +since I have a brou quality the variance + + + align:start position:0% +since I have a brou quality the variance +of my distribution is just pit1 minus + + align:start position:0% +of my distribution is just pit1 minus + + + align:start position:0% +of my distribution is just pit1 minus +pit if it's beri probability P so anyway + + align:start position:0% +pit if it's beri probability P so anyway + + + align:start position:0% +pit if it's beri probability P so anyway +the the new information is arriving with + + align:start position:0% +the the new information is arriving with + + + align:start position:0% +the the new information is arriving with +and and the and I'm getting square root + + align:start position:0% +and and the and I'm getting square root + + + align:start position:0% +and and the and I'm getting square root +of Lambda it is how much the standard + + align:start position:0% +of Lambda it is how much the standard + + + align:start position:0% +of Lambda it is how much the standard +deviation changes when you have Lambda + + align:start position:0% +deviation changes when you have Lambda + + + align:start position:0% +deviation changes when you have Lambda +it reviews and then DZ is a brownie in + + align:start position:0% +it reviews and then DZ is a brownie in + + + align:start position:0% +it reviews and then DZ is a brownie in +motion that's just positive or negative + + align:start position:0% +motion that's just positive or negative + + + align:start position:0% +motion that's just positive or negative +so you can think of it as the limit as + + align:start position:0% +so you can think of it as the limit as + + + align:start position:0% +so you can think of it as the limit as +you get just a number of a number of + + align:start position:0% +you get just a number of a number of + + + align:start position:0% +you get just a number of a number of +normally distributed signals saying this + + align:start position:0% +normally distributed signals saying this + + + align:start position:0% +normally distributed signals saying this +one was good this one was bad you know + + align:start position:0% +one was good this one was bad you know + + + align:start position:0% +one was good this one was bad you know +this good this bad this good this bad + + align:start position:0% +this good this bad this good this bad + + + align:start position:0% +this good this bad this good this bad +that pushes you back and forth in like a + + align:start position:0% +that pushes you back and forth in like a + + + align:start position:0% +that pushes you back and forth in like a +brownie and motion process you know + + align:start position:0% +brownie and motion process you know + + + align:start position:0% +brownie and motion process you know +um and you know why is he doing this in + + align:start position:0% +um and you know why is he doing this in + + + align:start position:0% +um and you know why is he doing this in +continuous time you know he's doing this + + align:start position:0% +continuous time you know he's doing this + + + align:start position:0% +continuous time you know he's doing this +in continuous time instead of in + + align:start position:0% +in continuous time instead of in + + + align:start position:0% +in continuous time instead of in +discreete time because you know it's + + align:start position:0% +discreete time because you know it's + + + align:start position:0% +discreete time because you know it's +sort of a state-of-the-art thing but + + align:start position:0% +sort of a state-of-the-art thing but + + + align:start position:0% +sort of a state-of-the-art thing but +it's just also the sometimes continuous + + align:start position:0% +it's just also the sometimes continuous + + + align:start position:0% +it's just also the sometimes continuous +models are easier to solve than discrete + + align:start position:0% +models are easier to solve than discrete + + + align:start position:0% +models are easier to solve than discrete +models you have to keep track of what + + align:start position:0% +models you have to keep track of what + + + align:start position:0% +models you have to keep track of what +your posterior could be if you've had + + align:start position:0% +your posterior could be if you've had + + + align:start position:0% +your posterior could be if you've had +three and four and five and seven + + align:start position:0% +three and four and five and seven + + + align:start position:0% +three and four and five and seven +signals The Continuous model easier to + + align:start position:0% +signals The Continuous model easier to + + + align:start position:0% +signals The Continuous model easier to +solve um so every consumer in each + + align:start position:0% +solve um so every consumer in each + + + align:start position:0% +solve um so every consumer in each +period um decides which so every + + align:start position:0% +period um decides which so every + + + align:start position:0% +period um decides which so every +consumer goes to exactly one restaurant + + align:start position:0% +consumer goes to exactly one restaurant + + + align:start position:0% +consumer goes to exactly one restaurant +they decide which um firm to visit if + + align:start position:0% +they decide which um firm to visit if + + + align:start position:0% +they decide which um firm to visit if +excess consumers visit any type of firm + + align:start position:0% +excess consumers visit any type of firm + + + align:start position:0% +excess consumers visit any type of firm +any firm then Services ration there's a + + align:start position:0% +any firm then Services ration there's a + + + align:start position:0% +any firm then Services ration there's a +line outside and only some of the people + + align:start position:0% +line outside and only some of the people + + + align:start position:0% +line outside and only some of the people +go in um consumers get utility Theta I + + align:start position:0% +go in um consumers get utility Theta I + + + align:start position:0% +go in um consumers get utility Theta I +plus Epsilon i j uh if they're served by + + align:start position:0% +plus Epsilon i j uh if they're served by + + + align:start position:0% +plus Epsilon i j uh if they're served by +restaurant I + + align:start position:0% + + + + align:start position:0% + +uh okay so given that all the firms + + align:start position:0% +uh okay so given that all the firms + + + align:start position:0% +uh okay so given that all the firms +priors are common knowledge in + + align:start position:0% +priors are common knowledge in + + + align:start position:0% +priors are common knowledge in +equilibrium everyone's going to get + + align:start position:0% +equilibrium everyone's going to get + + + align:start position:0% +equilibrium everyone's going to get +served with probability one at firms + + align:start position:0% +served with probability one at firms + + + align:start position:0% +served with probability one at firms +that have a rating of at least p p Tilda + + align:start position:0% +that have a rating of at least p p Tilda + + + align:start position:0% +that have a rating of at least p p Tilda +and you know if if your prior is like + + align:start position:0% +and you know if if your prior is like + + + align:start position:0% +and you know if if your prior is like +you know you have one table so it's + + align:start position:0% +you know you have one table so it's + + + align:start position:0% +you know you have one table so it's +going to be like a you're going to clear + + align:start position:0% +going to be like a you're going to clear + + + align:start position:0% +going to be like a you're going to clear +the market if your quality is high + + align:start position:0% +the market if your quality is high + + + align:start position:0% +the market if your quality is high +enough you're going to price at some you + + align:start position:0% +enough you're going to price at some you + + + align:start position:0% +enough you're going to price at some you +if your quality is at least ptil you're + + align:start position:0% +if your quality is at least ptil you're + + + align:start position:0% +if your quality is at least ptil you're +going to price at some equal ibrium + + align:start position:0% +going to price at some equal ibrium + + + align:start position:0% +going to price at some equal ibrium +price that gets people to come to your + + align:start position:0% +price that gets people to come to your + + + align:start position:0% +price that gets people to come to your +restaurant and you're going to price + + align:start position:0% +restaurant and you're going to price + + + align:start position:0% +restaurant and you're going to price +that exactly one customer comes if your + + align:start position:0% +that exactly one customer comes if your + + + align:start position:0% +that exactly one customer comes if your +price is attracting multiple customers + + align:start position:0% +price is attracting multiple customers + + + align:start position:0% +price is attracting multiple customers +you should be raising your price and + + align:start position:0% +you should be raising your price and + + + align:start position:0% +you should be raising your price and +getting fewer customers till you fill + + align:start position:0% +getting fewer customers till you fill + + + align:start position:0% +getting fewer customers till you fill +your + + align:start position:0% +your + + + align:start position:0% +your +capacity um at all higher + + align:start position:0% +capacity um at all higher + + + align:start position:0% +capacity um at all higher +prices everyone is going to be um yeah + + align:start position:0% +prices everyone is going to be um yeah + + + align:start position:0% +prices everyone is going to be um yeah +so you you can tell nil is a theorist + + align:start position:0% +so you you can tell nil is a theorist + + + align:start position:0% +so you you can tell nil is a theorist +not an Iowa Economist he's using Q for + + align:start position:0% +not an Iowa Economist he's using Q for + + + align:start position:0% +not an Iowa Economist he's using Q for +prices and P for qualities rather than P + + align:start position:0% +prices and P for qualities rather than P + + + align:start position:0% +prices and P for qualities rather than P +for prices and S for qualities so anyway + + align:start position:0% +for prices and S for qualities so anyway + + + align:start position:0% +for prices and S for qualities so anyway +the are setting these prices Q in + + align:start position:0% +the are setting these prices Q in + + + align:start position:0% +the are setting these prices Q in +equilibrium the prices are just P minus + + align:start position:0% +equilibrium the prices are just P minus + + + align:start position:0% +equilibrium the prices are just P minus +a constant uh and that makes consumers + + align:start position:0% +a constant uh and that makes consumers + + + align:start position:0% +a constant uh and that makes consumers +indifferent to going to all high quality + + align:start position:0% +indifferent to going to all high quality + + + align:start position:0% +indifferent to going to all high quality +restaurants and has all high quality + + align:start position:0% +restaurants and has all high quality + + + align:start position:0% +restaurants and has all high quality +restaurants attracting exactly one + + align:start position:0% +restaurants attracting exactly one + + + align:start position:0% +restaurants attracting exactly one +customer you know why you price it P + + align:start position:0% +customer you know why you price it P + + + align:start position:0% +customer you know why you price it P +minus W it's because there are + + align:start position:0% +minus W it's because there are + + + align:start position:0% +minus W it's because there are +lowquality restaurants that people + + align:start position:0% +lowquality restaurants that people + + + align:start position:0% +lowquality restaurants that people +aren't going to want to go to that are + + align:start position:0% +aren't going to want to go to that are + + + align:start position:0% +aren't going to want to go to that are +willing to sell it a loss because they + + align:start position:0% +willing to sell it a loss because they + + + align:start position:0% +willing to sell it a loss because they +sell at a loss they get people to come + + align:start position:0% +sell at a loss they get people to come + + + align:start position:0% +sell at a loss they get people to come +and review + + align:start position:0% +and review + + + align:start position:0% +and review +them okay so in his model the basically + + align:start position:0% +them okay so in his model the basically + + + align:start position:0% +them okay so in his model the basically +the Lambda it the review arrival rate is + + align:start position:0% +the Lambda it the review arrival rate is + + + align:start position:0% +the Lambda it the review arrival rate is +going to be a sum of two terms it's + + align:start position:0% +going to be a sum of two terms it's + + + align:start position:0% +going to be a sum of two terms it's +going to be a sum Lambda is going to be + + align:start position:0% +going to be a sum Lambda is going to be + + + align:start position:0% +going to be a sum Lambda is going to be +the number of customers who visit your + + align:start position:0% +the number of customers who visit your + + + align:start position:0% +the number of customers who visit your +restaurant um because it's optimal to do + + align:start position:0% +restaurant um because it's optimal to do + + + align:start position:0% +restaurant um because it's optimal to do +so plus Epsilon so there's this Epsilon + + align:start position:0% +so plus Epsilon so there's this Epsilon + + + align:start position:0% +so plus Epsilon so there's this Epsilon +background rate of arrivals of we'll + + align:start position:0% +background rate of arrivals of we'll + + + align:start position:0% +background rate of arrivals of we'll +call them tourists from out of town who + + align:start position:0% +call them tourists from out of town who + + + align:start position:0% +call them tourists from out of town who +have no idea what the qualities are and + + align:start position:0% +have no idea what the qualities are and + + + align:start position:0% +have no idea what the qualities are and +just show up randomly at your restaurant + + align:start position:0% +just show up randomly at your restaurant + + + align:start position:0% +just show up randomly at your restaurant +so most reviews come from the one one + + align:start position:0% +so most reviews come from the one one + + + align:start position:0% +so most reviews come from the one one +person who buy who knows your quality + + align:start position:0% +person who buy who knows your quality + + + align:start position:0% +person who buy who knows your quality +and buys it but there is this Epsilon + + align:start position:0% +and buys it but there is this Epsilon + + + align:start position:0% +and buys it but there is this Epsilon +arrival rate + + align:start position:0% +arrival rate + + + align:start position:0% +arrival rate +okay um the firms that are hanging + + align:start position:0% +okay um the firms that are hanging + + + align:start position:0% +okay um the firms that are hanging +around that have low quality they would + + align:start position:0% +around that have low quality they would + + + align:start position:0% +around that have low quality they would +like people to come to their restaurant + + align:start position:0% +like people to come to their restaurant + + + align:start position:0% +like people to come to their restaurant +and review it so they can learn if their + + align:start position:0% +and review it so they can learn if their + + + align:start position:0% +and review it so they can learn if their +quality is high and they can start + + align:start position:0% +quality is high and they can start + + + align:start position:0% +quality is high and they can start +charging more money for their restaurant + + align:start position:0% +charging more money for their restaurant + + + align:start position:0% +charging more money for their restaurant +if it's high or exit if their quality is + + align:start position:0% +if it's high or exit if their quality is + + + align:start position:0% +if it's high or exit if their quality is +low uh but there's only so much they're + + align:start position:0% +low uh but there's only so much they're + + + align:start position:0% +low uh but there's only so much they're +willing to pay to you know like so + + align:start position:0% +willing to pay to you know like so + + + align:start position:0% +willing to pay to you know like so +they're willing to sort of price below + + align:start position:0% +they're willing to sort of price below + + + align:start position:0% +they're willing to sort of price below +cost to get people to come to their + + align:start position:0% +cost to get people to come to their + + + align:start position:0% +cost to get people to come to their +restaurant there's only so much you're + + align:start position:0% +restaurant there's only so much you're + + + align:start position:0% +restaurant there's only so much you're +willing to do that because at some point + + align:start position:0% +willing to do that because at some point + + + align:start position:0% +willing to do that because at some point +you're just better off exiting okay + + align:start position:0% +you're just better off exiting okay + + + align:start position:0% +you're just better off exiting okay +anyway so that that's why you have this + + align:start position:0% +anyway so that that's why you have this + + + align:start position:0% +anyway so that that's why you have this +sort of positive W that is everybody is + + align:start position:0% +sort of positive W that is everybody is + + + align:start position:0% +sort of positive W that is everybody is +everybody is giving consumers some + + align:start position:0% +everybody is giving consumers some + + + align:start position:0% +everybody is giving consumers some +Surplus because the guys who are on the + + align:start position:0% +Surplus because the guys who are on the + + + align:start position:0% +Surplus because the guys who are on the +outside looking in are going to give the + + align:start position:0% +outside looking in are going to give the + + + align:start position:0% +outside looking in are going to give the +consumer some Surplus to try to get the + + align:start position:0% +consumer some Surplus to try to get the + + + align:start position:0% +consumer some Surplus to try to get the +customers to + + align:start position:0% +customers to + + + align:start position:0% +customers to +come okay so I'm going to write V of P + + align:start position:0% +come okay so I'm going to write V of P + + + align:start position:0% +come okay so I'm going to write V of P +for the value function of a firm that + + align:start position:0% +for the value function of a firm that + + + align:start position:0% +for the value function of a firm that +has posterior p uh free entry implies + + align:start position:0% +has posterior p uh free entry implies + + + align:start position:0% +has posterior p uh free entry implies +that V of P not equals K when the firms + + align:start position:0% +that V of P not equals K when the firms + + + align:start position:0% +that V of P not equals K when the firms +are entering it must be that their + + align:start position:0% +are entering it must be that their + + + align:start position:0% +are entering it must be that their +lifetime expected discounted value of + + align:start position:0% +lifetime expected discounted value of + + + align:start position:0% +lifetime expected discounted value of +profits is exactly equal to the fixed + + align:start position:0% +profits is exactly equal to the fixed + + + align:start position:0% +profits is exactly equal to the fixed +costs um and then exit occurs when your + + align:start position:0% +costs um and then exit occurs when your + + + align:start position:0% +costs um and then exit occurs when your +posterior gets down to P lower bar where + + align:start position:0% +posterior gets down to P lower bar where + + + align:start position:0% +posterior gets down to P lower bar where +V of P lower bar is zero and V of P + + align:start position:0% +V of P lower bar is zero and V of P + + + align:start position:0% +V of P lower bar is zero and V of P +lower bar is zero in this model without + + align:start position:0% +lower bar is zero in this model without + + + align:start position:0% +lower bar is zero in this model without +the scrappage because there's this flow + + align:start position:0% +the scrappage because there's this flow + + + align:start position:0% +the scrappage because there's this flow +cost of + + align:start position:0% + + + + align:start position:0% + +operation you know a complicated model + + align:start position:0% +operation you know a complicated model + + + align:start position:0% +operation you know a complicated model +but I sort of thought what I would do is + + align:start position:0% +but I sort of thought what I would do is + + + align:start position:0% +but I sort of thought what I would do is +here just sort of show you a couple of + + align:start position:0% +here just sort of show you a couple of + + + align:start position:0% +here just sort of show you a couple of +the graphs and talk through uh when what + + align:start position:0% +the graphs and talk through uh when what + + + align:start position:0% +the graphs and talk through uh when what +ends up happening so first observation + + align:start position:0% +ends up happening so first observation + + + align:start position:0% +ends up happening so first observation +um so it's not yeah so if you're a new + + align:start position:0% +um so it's not yeah so if you're a new + + + align:start position:0% +um so it's not yeah so if you're a new +firm um and people you know you're not + + align:start position:0% +firm um and people you know you're not + + + align:start position:0% +firm um and people you know you're not +like there's some sense + + align:start position:0% +like there's some sense + + + align:start position:0% +like there's some sense +um in equilibrium like if if the number + + align:start position:0% +um in equilibrium like if if the number + + + align:start position:0% +um in equilibrium like if if the number +of customers is is X the X best + + align:start position:0% +of customers is is X the X best + + + align:start position:0% +of customers is is X the X best +restaurants are going to all get one + + align:start position:0% +restaurants are going to all get one + + + align:start position:0% +restaurants are going to all get one +customer each and every restaurant below + + align:start position:0% +customer each and every restaurant below + + + align:start position:0% +customer each and every restaurant below +X is going to get no + + align:start position:0% +X is going to get no + + + align:start position:0% +X is going to get no +customers other than the randomly + + align:start position:0% +customers other than the randomly + + + align:start position:0% +customers other than the randomly +arriving tourists um but firms if you're + + align:start position:0% +arriving tourists um but firms if you're + + + align:start position:0% +arriving tourists um but firms if you're +just on the outside looking in so if + + align:start position:0% +just on the outside looking in so if + + + align:start position:0% +just on the outside looking in so if +like you know if we have this sort of uh + + align:start position:0% +like you know if we have this sort of uh + + + align:start position:0% +like you know if we have this sort of uh +posterior on my quality I think it is + + align:start position:0% +posterior on my quality I think it is + + + align:start position:0% +posterior on my quality I think it is +Pete tild I called it so everybody up + + align:start position:0% +Pete tild I called it so everybody up + + + align:start position:0% +Pete tild I called it so everybody up +here fills their restaurant everybody + + align:start position:0% +here fills their restaurant everybody + + + align:start position:0% +here fills their restaurant everybody +else here only gets the Epsilon flow of + + align:start position:0% +else here only gets the Epsilon flow of + + + align:start position:0% +else here only gets the Epsilon flow of +tourists um if your quality is right + + align:start position:0% +tourists um if your quality is right + + + align:start position:0% +tourists um if your quality is right +here you're willing to lose some money + + align:start position:0% +here you're willing to lose some money + + + align:start position:0% +here you're willing to lose some money +in order to get the customers to visit + + align:start position:0% +in order to get the customers to visit + + + align:start position:0% +in order to get the customers to visit +your restaurant to find out whether your + + align:start position:0% +your restaurant to find out whether your + + + align:start position:0% +your restaurant to find out whether your +restaurant is Goods you can get in or + + align:start position:0% +restaurant is Goods you can get in or + + + align:start position:0% +restaurant is Goods you can get in or +out of the + + align:start position:0% +out of the + + + align:start position:0% +out of the +market so anyway firms pric somewhat + + align:start position:0% +market so anyway firms pric somewhat + + + align:start position:0% +market so anyway firms pric somewhat +below cost to attract customers you know + + align:start position:0% +below cost to attract customers you know + + + align:start position:0% +below cost to attract customers you know +because this guy is is selling at a this + + align:start position:0% +because this guy is is selling at a this + + + align:start position:0% +because this guy is is selling at a this +guy's willing to sell at a loss + + align:start position:0% +guy's willing to sell at a loss + + + align:start position:0% +guy's willing to sell at a loss +everybody else has they can everybody + + align:start position:0% +everybody else has they can everybody + + + align:start position:0% +everybody else has they can everybody +else can only charge their sort of + + align:start position:0% +else can only charge their sort of + + + align:start position:0% +else can only charge their sort of +marginal value above this guy um their + + align:start position:0% +marginal value above this guy um their + + + align:start position:0% +marginal value above this guy um their +marginal quality above that guy so + + align:start position:0% +marginal quality above that guy so + + + align:start position:0% +marginal quality above that guy so +consumers get you know consumers get + + align:start position:0% +consumers get you know consumers get + + + align:start position:0% +consumers get you know consumers get +some profit what what what is the + + align:start position:0% +some profit what what what is the + + + align:start position:0% +some profit what what what is the +consumer surplus the consumer surplus + + align:start position:0% +consumer surplus the consumer surplus + + + align:start position:0% +consumer surplus the consumer surplus +here is the amount of money this guy's + + align:start position:0% +here is the amount of money this guy's + + + align:start position:0% +here is the amount of money this guy's +willing to lose because the amount of + + align:start position:0% +willing to lose because the amount of + + + align:start position:0% +willing to lose because the amount of +money that this guy is willing to lose + + align:start position:0% +money that this guy is willing to lose + + + align:start position:0% +money that this guy is willing to lose +is uh the the W is then whatever what + + align:start position:0% +is uh the the W is then whatever what + + + align:start position:0% +is uh the the W is then whatever what +you get at all higher quality restaurant + + align:start position:0% +you get at all higher quality restaurant + + + align:start position:0% +you get at all higher quality restaurant +um with full information uh learning + + align:start position:0% +um with full information uh learning + + + align:start position:0% +um with full information uh learning +about new entrance is very slow uh and + + align:start position:0% +about new entrance is very slow uh and + + + align:start position:0% +about new entrance is very slow uh and +firms exit after they just get some bad + + align:start position:0% +firms exit after they just get some bad + + + align:start position:0% +firms exit after they just get some bad +news so here is his + + align:start position:0% +news so here is his + + + align:start position:0% +news so here is his +um you know this is an example where um + + align:start position:0% +um you know this is an example where um + + + align:start position:0% +um you know this is an example where um +peot the prior is in the range where + + align:start position:0% +peot the prior is in the range where + + + align:start position:0% +peot the prior is in the range where +you're not in in the money on on + + align:start position:0% +you're not in in the money on on + + + align:start position:0% +you're not in in the money on on +customers so at a peot restaurant + + align:start position:0% +customers so at a peot restaurant + + + align:start position:0% +customers so at a peot restaurant +uh you're not you're not getting very + + align:start position:0% +uh you're not you're not getting very + + + align:start position:0% +uh you're not you're not getting very +many you're not you're you're out of the + + align:start position:0% +many you're not you're you're out of the + + + align:start position:0% +many you're not you're you're out of the +money customers are not coming to you + + align:start position:0% +money customers are not coming to you + + + align:start position:0% +money customers are not coming to you +and so what we get is there's a lot of + + align:start position:0% +and so what we get is there's a lot of + + + align:start position:0% +and so what we get is there's a lot of +firms who just entered about who the + + align:start position:0% +firms who just entered about who the + + + align:start position:0% +firms who just entered about who the +prior quality is p not and only Epsilon + + align:start position:0% +prior quality is p not and only Epsilon + + + align:start position:0% +prior quality is p not and only Epsilon +people go to them and so we get a lot of + + align:start position:0% +people go to them and so we get a lot of + + + align:start position:0% +people go to them and so we get a lot of +mass there because when they're only + + align:start position:0% +mass there because when they're only + + + align:start position:0% +mass there because when they're only +Epsilon customers people don't learn + + align:start position:0% +Epsilon customers people don't learn + + + align:start position:0% +Epsilon customers people don't learn +much and your posterior about their + + align:start position:0% +much and your posterior about their + + + align:start position:0% +much and your posterior about their +quality doesn't move very fast if you + + align:start position:0% +quality doesn't move very fast if you + + + align:start position:0% +quality doesn't move very fast if you +get one or two bad + + align:start position:0% +get one or two bad + + + align:start position:0% +get one or two bad +reviews then you just you just exit so + + align:start position:0% +reviews then you just you just exit so + + + align:start position:0% +reviews then you just you just exit so +bad you know like you your start here + + align:start position:0% +bad you know like you your start here + + + align:start position:0% +bad you know like you your start here +you get a bad review or two you just + + align:start position:0% +you get a bad review or two you just + + + align:start position:0% +you get a bad review or two you just +exit the market and then Al so there + + align:start position:0% +exit the market and then Al so there + + + align:start position:0% +exit the market and then Al so there +aren't many firms down here with these + + align:start position:0% +aren't many firms down here with these + + + align:start position:0% +aren't many firms down here with these +qualities because two bad reviews you + + align:start position:0% +qualities because two bad reviews you + + + align:start position:0% +qualities because two bad reviews you +leave and then even if you would have + + align:start position:0% +leave and then even if you would have + + + align:start position:0% +leave and then even if you would have +gotten a third review coming back up + + align:start position:0% +gotten a third review coming back up + + + align:start position:0% +gotten a third review coming back up +you're not there + + align:start position:0% +you're not there + + + align:start position:0% +you're not there +anymore + + align:start position:0% +anymore + + + align:start position:0% +anymore +um then there are fewer firms with + + align:start position:0% +um then there are fewer firms with + + + align:start position:0% +um then there are fewer firms with +qualities here because once your quality + + align:start position:0% +qualities here because once your quality + + + align:start position:0% +qualities here because once your quality +your posterior gets above P upper bar + + align:start position:0% +your posterior gets above P upper bar + + + align:start position:0% +your posterior gets above P upper bar +people learn about you very quickly + + align:start position:0% +people learn about you very quickly + + + align:start position:0% +people learn about you very quickly +people learn about you very quickly your + + align:start position:0% +people learn about you very quickly your + + + align:start position:0% +people learn about you very quickly your +distribution moves and either moves back + + align:start position:0% +distribution moves and either moves back + + + align:start position:0% +distribution moves and either moves back +to this range where no one's coming to + + align:start position:0% +to this range where no one's coming to + + + align:start position:0% +to this range where no one's coming to +your restaurant or it moves up and and + + align:start position:0% +your restaurant or it moves up and and + + + align:start position:0% +your restaurant or it moves up and and +people learn it's good and you know in + + align:start position:0% +people learn it's good and you know in + + + align:start position:0% +people learn it's good and you know in +this model everyone's either zero or one + + align:start position:0% +this model everyone's either zero or one + + + align:start position:0% +this model everyone's either zero or one +so very quickly people learn that you're + + align:start position:0% +so very quickly people learn that you're + + + align:start position:0% +so very quickly people learn that you're +a quality One + + align:start position:0% +a quality One + + + align:start position:0% +a quality One +Restaurant okay so we get this sort of + + align:start position:0% +Restaurant okay so we get this sort of + + + align:start position:0% +Restaurant okay so we get this sort of +distribution of firm qualities where + + align:start position:0% +distribution of firm qualities where + + + align:start position:0% +distribution of firm qualities where +there are a lot of firms that are having + + align:start position:0% +there are a lot of firms that are having + + + align:start position:0% +there are a lot of firms that are having +trouble attracting anyone reviews they + + align:start position:0% +trouble attracting anyone reviews they + + + align:start position:0% +trouble attracting anyone reviews they +stay hang out here and their their + + align:start position:0% +stay hang out here and their their + + + align:start position:0% +stay hang out here and their their +poster don't move much and then once you + + align:start position:0% +poster don't move much and then once you + + + align:start position:0% +poster don't move much and then once you +get a some threshold you move very + + align:start position:0% +get a some threshold you move very + + + align:start position:0% +get a some threshold you move very +quickly either back into the range where + + align:start position:0% +quickly either back into the range where + + + align:start position:0% +quickly either back into the range where +you don't learn much or into the year + + align:start position:0% +you don't learn much or into the year + + + align:start position:0% +you don't learn much or into the year +quality is one and then people all start + + align:start position:0% +quality is one and then people all start + + + align:start position:0% +quality is one and then people all start +going + + align:start position:0% + + + + align:start position:0% + +you + + align:start position:0% +you + + + align:start position:0% +you +um you know consumer welfare under any + + align:start position:0% +um you know consumer welfare under any + + + align:start position:0% +um you know consumer welfare under any +policy is the W that arises given the + + align:start position:0% +policy is the W that arises given the + + + align:start position:0% +policy is the W that arises given the +policy so consumer + + align:start position:0% +policy so consumer + + + align:start position:0% +policy so consumer +optimality like what's best for + + align:start position:0% +optimality like what's best for + + + align:start position:0% +optimality like what's best for +consumers if like you're trying to if + + align:start position:0% +consumers if like you're trying to if + + + align:start position:0% +consumers if like you're trying to if +you're Yelp and you're trying to design + + align:start position:0% +you're Yelp and you're trying to design + + + align:start position:0% +you're Yelp and you're trying to design +my platform to be consumer optimal so + + align:start position:0% +my platform to be consumer optimal so + + + align:start position:0% +my platform to be consumer optimal so +people will continue to use Yelp what's + + align:start position:0% +people will continue to use Yelp what's + + + align:start position:0% +people will continue to use Yelp what's +optimal for the firm to do is to give + + align:start position:0% +optimal for the firm to do is to give + + + align:start position:0% +optimal for the firm to do is to give +firms an incentive to be willing to + + align:start position:0% +firms an incentive to be willing to + + + align:start position:0% +firms an incentive to be willing to +price Billow cost to have firms learn + + align:start position:0% +price Billow cost to have firms learn + + + align:start position:0% +price Billow cost to have firms learn +about + + align:start position:0% +about + + + align:start position:0% +about +them and so then what do you get about + + align:start position:0% +them and so then what do you get about + + + align:start position:0% +them and so then what do you get about +what would be the optimal policy if + + align:start position:0% +what would be the optimal policy if + + + align:start position:0% +what would be the optimal policy if +you're trying to get these guys to be + + align:start position:0% +you're trying to get these guys to be + + + align:start position:0% +you're trying to get these guys to be +willing to pay a lot to get more + + align:start position:0% +willing to pay a lot to get more + + + align:start position:0% +willing to pay a lot to get more +reviews um and it turns out that one of + + align:start position:0% +reviews um and it turns out that one of + + + align:start position:0% +reviews um and it turns out that one of +the answer is that you want to have a + + align:start position:0% +the answer is that you want to have a + + + align:start position:0% +the answer is that you want to have a +partially revealing customer policy + + align:start position:0% +partially revealing customer policy + + + align:start position:0% +partially revealing customer policy +where you don't um publish all the + + align:start position:0% +where you don't um publish all the + + + align:start position:0% +where you don't um publish all the +reviews about high quality firms what + + align:start position:0% +reviews about high quality firms what + + + align:start position:0% +reviews about high quality firms what +you want to do is in some sense as soon + + align:start position:0% +you want to do is in some sense as soon + + + align:start position:0% +you want to do is in some sense as soon +soon as a firm's posterior passes P + + align:start position:0% +soon as a firm's posterior passes P + + + align:start position:0% +soon as a firm's posterior passes P +Tilda you want to stop publishing any + + align:start position:0% +Tilda you want to stop publishing any + + + align:start position:0% +Tilda you want to stop publishing any +reviews about them + + align:start position:0% +reviews about them + + + align:start position:0% +reviews about them +whatsoever and you do that because that + + align:start position:0% +whatsoever and you do that because that + + + align:start position:0% +whatsoever and you do that because that +way you know by having sort of a flat + + align:start position:0% +way you know by having sort of a flat + + + align:start position:0% +way you know by having sort of a flat +benefit from being quality P Tilda or + + align:start position:0% +benefit from being quality P Tilda or + + + align:start position:0% +benefit from being quality P Tilda or +all the way up to here when you have + + align:start position:0% +all the way up to here when you have + + + align:start position:0% +all the way up to here when you have +sort of a flatter benefit from high + + align:start position:0% +sort of a flatter benefit from high + + + align:start position:0% +sort of a flatter benefit from high +quality there's greater incentive to + + align:start position:0% +quality there's greater incentive to + + + align:start position:0% +quality there's greater incentive to +make the jump from here up to + + align:start position:0% +make the jump from here up to + + + align:start position:0% +make the jump from here up to +here um and therefore these firms are + + align:start position:0% +here um and therefore these firms are + + + align:start position:0% +here um and therefore these firms are +willing to price further below cost in + + align:start position:0% +willing to price further below cost in + + + align:start position:0% +willing to price further below cost in +order to make that jump and then you + + align:start position:0% +order to make that jump and then you + + + align:start position:0% +order to make that jump and then you +know you are disadvantaging some firms + + align:start position:0% +know you are disadvantaging some firms + + + align:start position:0% +know you are disadvantaging some firms +you're hurting firms up here helping + + align:start position:0% +you're hurting firms up here helping + + + align:start position:0% +you're hurting firms up here helping +firms down here by not promoting qu + + align:start position:0% +firms down here by not promoting qu + + + align:start position:0% +firms down here by not promoting qu +providing quality information on them + + align:start position:0% +providing quality information on them + + + align:start position:0% +providing quality information on them +that lets them show that they're really + + align:start position:0% +that lets them show that they're really + + + align:start position:0% +that lets them show that they're really +good um but since new firms are much + + align:start position:0% +good um but since new firms are much + + + align:start position:0% +good um but since new firms are much +more likely to be here than they are to + + align:start position:0% +more likely to be here than they are to + + + align:start position:0% +more likely to be here than they are to +be here when you're here you're willing + + align:start position:0% +be here when you're here you're willing + + + align:start position:0% +be here when you're here you're willing +to pay more to get up if you sort of + + align:start position:0% +to pay more to get up if you sort of + + + align:start position:0% +to pay more to get up if you sort of +take some of the Surplus away from the + + align:start position:0% +take some of the Surplus away from the + + + align:start position:0% +take some of the Surplus away from the +really successful firms and give it to + + align:start position:0% +really successful firms and give it to + + + align:start position:0% +really successful firms and give it to +the moderately successful firms that + + align:start position:0% +the moderately successful firms that + + + align:start position:0% +the moderately successful firms that +raises the incentive to price in that + + align:start position:0% +raises the incentive to price in that + + + align:start position:0% +raises the incentive to price in that +way so so what he argues is that you + + align:start position:0% +way so so what he argues is that you + + + align:start position:0% +way so so what he argues is that you +know what what a platform would like to + + align:start position:0% +know what what a platform would like to + + + align:start position:0% +know what what a platform would like to +do in in this model is to actually give + + align:start position:0% +do in in this model is to actually give + + + align:start position:0% +do in in this model is to actually give +incomplete information about restaurants + + align:start position:0% +incomplete information about restaurants + + + align:start position:0% +incomplete information about restaurants +and to sort of selectively give + + align:start position:0% +and to sort of selectively give + + + align:start position:0% +and to sort of selectively give +information where uh we restrict + + align:start position:0% +information where uh we restrict + + + align:start position:0% +information where uh we restrict +information about the good products so + + align:start position:0% +information about the good products so + + + align:start position:0% +information about the good products so +that we have + + align:start position:0% +that we have + + + align:start position:0% +that we have +more so that there's more of a benefit + + align:start position:0% +more so that there's more of a benefit + + + align:start position:0% +more so that there's more of a benefit +to having a pretty good reputation so + + align:start position:0% +to having a pretty good reputation so + + + align:start position:0% +to having a pretty good reputation so +that new firms will then invest more in + + align:start position:0% +that new firms will then invest more in + + + align:start position:0% +that new firms will then invest more in +trying to get the pretty good reputation + + align:start position:0% +trying to get the pretty good reputation + + + align:start position:0% +trying to get the pretty good reputation +and then obviously all the other firms + + align:start position:0% +and then obviously all the other firms + + + align:start position:0% +and then obviously all the other firms +are pricing you know off have to price + + align:start position:0% +are pricing you know off have to price + + + align:start position:0% +are pricing you know off have to price +to out compete those guys + + align:start position:0% +to out compete those guys + + + align:start position:0% +to out compete those guys +okay okay that is it I that's what I had + + align:start position:0% +okay okay that is it I that's what I had + + + align:start position:0% +okay okay that is it I that's what I had +for today so uh Wednesday I'm going to + + align:start position:0% +for today so uh Wednesday I'm going to + + + align:start position:0% +for today so uh Wednesday I'm going to +talk about uh empirical work on Entry uh + + align:start position:0% +talk about uh empirical work on Entry uh + + + align:start position:0% +talk about uh empirical work on Entry uh +I would say you know breast Nan Reese is + + align:start position:0% +I would say you know breast Nan Reese is + + + align:start position:0% +I would say you know breast Nan Reese is +really a be is really the classic paper + + align:start position:0% +really a be is really the classic paper + + + align:start position:0% +really a be is really the classic paper +on Entry again breast and hand Reese is + + align:start position:0% +on Entry again breast and hand Reese is + + + align:start position:0% +on Entry again breast and hand Reese is +a little old by now so I would say that + + align:start position:0% +a little old by now so I would say that + + + align:start position:0% +a little old by now so I would say that +if you want to read things you know I + + align:start position:0% +if you want to read things you know I + + + align:start position:0% +if you want to read things you know I +will tell you what's in breast and Han + + align:start position:0% +will tell you what's in breast and Han + + + align:start position:0% +will tell you what's in breast and Han +and Reese with slightly more modern + + align:start position:0% +and Reese with slightly more modern + + + align:start position:0% +and Reese with slightly more modern +econometrics or what would be in it and + + align:start position:0% +econometrics or what would be in it and + + + align:start position:0% +econometrics or what would be in it and +then maybe read uh Barry W Fogle or look + + align:start position:0% +then maybe read uh Barry W Fogle or look + + + align:start position:0% +then maybe read uh Barry W Fogle or look +at like one of the bronen maybe brenberg + + align:start position:0% +at like one of the bronen maybe brenberg + + + align:start position:0% +at like one of the bronen maybe brenberg +D dubet or whatever but sort of talk + + align:start position:0% +D dubet or whatever but sort of talk + + + align:start position:0% +D dubet or whatever but sort of talk +about those four papers \ No newline at end of file diff --git a/lyR4HQ01nos.txt b/lyR4HQ01nos.txt new file mode 100644 index 0000000000000000000000000000000000000000..ece608243e54fa1b30e93eccc13549719c09a8c8 --- /dev/null +++ b/lyR4HQ01nos.txt @@ -0,0 +1,643 @@ +align:start position:0% + +um the students spend about six hours in + + align:start position:0% +um the students spend about six hours in + + + align:start position:0% +um the students spend about six hours in +class uh each week and right at the + + align:start position:0% +class uh each week and right at the + + + align:start position:0% +class uh each week and right at the +beginning of the semester most of those + + align:start position:0% +beginning of the semester most of those + + + align:start position:0% +beginning of the semester most of those +six hours are either lectures or uh + + align:start position:0% +six hours are either lectures or uh + + + align:start position:0% +six hours are either lectures or uh +activities or workshops that we have + + align:start position:0% +activities or workshops that we have + + + align:start position:0% +activities or workshops that we have +planned to have inside the the class is + + align:start position:0% +planned to have inside the the class is + + + align:start position:0% +planned to have inside the the class is +very very tightly programmed um this may + + align:start position:0% +very very tightly programmed um this may + + + align:start position:0% +very very tightly programmed um this may +involve say brainstorming for the the + + align:start position:0% +involve say brainstorming for the the + + + align:start position:0% +involve say brainstorming for the the +team projects or forming up with teams + + align:start position:0% +team projects or forming up with teams + + + align:start position:0% +team projects or forming up with teams +uh going through the project uh + + align:start position:0% +uh going through the project uh + + + align:start position:0% +uh going through the project uh +constraints teaching them the techniques + + align:start position:0% +constraints teaching them the techniques + + + align:start position:0% +constraints teaching them the techniques +that we want them to learn near the end + + align:start position:0% +that we want them to learn near the end + + + align:start position:0% +that we want them to learn near the end +of the semester we heavily scale back + + align:start position:0% +of the semester we heavily scale back + + + align:start position:0% +of the semester we heavily scale back +the programmed content we uh give + + align:start position:0% +the programmed content we uh give + + + align:start position:0% +the programmed content we uh give +students a lot of class time just to + + align:start position:0% +students a lot of class time just to + + + align:start position:0% +students a lot of class time just to +meet up with the teams because for many + + align:start position:0% +meet up with the teams because for many + + + align:start position:0% +meet up with the teams because for many +many teams it's difficult enough to + + align:start position:0% +many teams it's difficult enough to + + + align:start position:0% +many teams it's difficult enough to +gather you know six people uh in the + + align:start position:0% +gather you know six people uh in the + + + align:start position:0% +gather you know six people uh in the +same room at the same place at the same + + align:start position:0% +same room at the same place at the same + + + align:start position:0% +same room at the same place at the same +time to get eight of them in the same + + align:start position:0% +time to get eight of them in the same + + + align:start position:0% +time to get eight of them in the same +room well if you're doing it during + + align:start position:0% +room well if you're doing it during + + + align:start position:0% +room well if you're doing it during +class time at least you know everybody's + + align:start position:0% +class time at least you know everybody's + + + align:start position:0% +class time at least you know everybody's +going to be there so uh so we try to + + align:start position:0% +going to be there so uh so we try to + + + align:start position:0% +going to be there so uh so we try to +give as much time as possible later in + + align:start position:0% +give as much time as possible later in + + + align:start position:0% +give as much time as possible later in +the semester for teams to actually work + + align:start position:0% +the semester for teams to actually work + + + align:start position:0% +the semester for teams to actually work +on their project but sometimes that is + + align:start position:0% +on their project but sometimes that is + + + align:start position:0% +on their project but sometimes that is +planned out like play test sessions for + + align:start position:0% +planned out like play test sessions for + + + align:start position:0% +planned out like play test sessions for +instance where um students play each + + align:start position:0% +instance where um students play each + + + align:start position:0% +instance where um students play each +other's + + align:start position:0% + + + + align:start position:0% + +games yeah the first um half of the + + align:start position:0% +games yeah the first um half of the + + + align:start position:0% +games yeah the first um half of the +semester is all the lecture and the + + align:start position:0% +semester is all the lecture and the + + + align:start position:0% +semester is all the lecture and the +workshops are are given by by the staff + + align:start position:0% +workshops are are given by by the staff + + + align:start position:0% +workshops are are given by by the staff +um but by the second half of the + + align:start position:0% +um but by the second half of the + + + align:start position:0% +um but by the second half of the +semester we're getting them to see other + + align:start position:0% +semester we're getting them to see other + + + align:start position:0% +semester we're getting them to see other +aspects of game development So within M + + align:start position:0% +aspects of game development So within M + + + align:start position:0% +aspects of game development So within M +students um and actually this year a few + + align:start position:0% +students um and actually this year a few + + + align:start position:0% +students um and actually this year a few +Wellsley students most of our students + + align:start position:0% +Wellsley students most of our students + + + align:start position:0% +Wellsley students most of our students +are going to be coming to to us with a + + align:start position:0% +are going to be coming to to us with a + + + align:start position:0% +are going to be coming to to us with a +programming background a few might have + + align:start position:0% +programming background a few might have + + + align:start position:0% +programming background a few might have +some design um classes under the belt + + align:start position:0% +some design um classes under the belt + + + align:start position:0% +some design um classes under the belt +maybe they've taken one of our game + + align:start position:0% +maybe they've taken one of our game + + + align:start position:0% +maybe they've taken one of our game +design classes or another design class + + align:start position:0% +design classes or another design class + + + align:start position:0% +design classes or another design class +offered at M some of the students are + + align:start position:0% +offered at M some of the students are + + + align:start position:0% +offered at M some of the students are +going to have some art aptitude like + + align:start position:0% +going to have some art aptitude like + + + align:start position:0% +going to have some art aptitude like +visual art aptitude some a little bit + + align:start position:0% +visual art aptitude some a little bit + + + align:start position:0% +visual art aptitude some a little bit +more um uh sound design or music + + align:start position:0% +more um uh sound design or music + + + align:start position:0% +more um uh sound design or music +composition aptitude but for the most + + align:start position:0% +composition aptitude but for the most + + + align:start position:0% +composition aptitude but for the most +part they don't know what it's like to + + align:start position:0% +part they don't know what it's like to + + + align:start position:0% +part they don't know what it's like to +be an artist they don't know what it's + + align:start position:0% +be an artist they don't know what it's + + + align:start position:0% +be an artist they don't know what it's +like to be a sound designer on a game + + align:start position:0% +like to be a sound designer on a game + + + align:start position:0% +like to be a sound designer on a game +development project um and they might + + align:start position:0% +development project um and they might + + + align:start position:0% +development project um and they might +actually not know anything about the + + align:start position:0% +actually not know anything about the + + + align:start position:0% +actually not know anything about the +business of games so the last half of + + align:start position:0% +business of games so the last half of + + + align:start position:0% +business of games so the last half of +the semester is bringing in guest + + align:start position:0% +the semester is bringing in guest + + + align:start position:0% +the semester is bringing in guest +lectures from the industry um we've got + + align:start position:0% +lectures from the industry um we've got + + + align:start position:0% +lectures from the industry um we've got +a great Network here in Boston um an + + align:start position:0% +a great Network here in Boston um an + + + align:start position:0% +a great Network here in Boston um an +independent game developer Network um + + align:start position:0% +independent game developer Network um + + + align:start position:0% +independent game developer Network um +also um quite a few of the AAA larger + + align:start position:0% +also um quite a few of the AAA larger + + + align:start position:0% +also um quite a few of the AAA larger +studios are here so we we mine our + + align:start position:0% +studios are here so we we mine our + + + align:start position:0% +studios are here so we we mine our +Network and each year we get new um + + align:start position:0% +Network and each year we get new um + + + align:start position:0% +Network and each year we get new um +speakers to come talk to them about how + + align:start position:0% +speakers to come talk to them about how + + + align:start position:0% +speakers to come talk to them about how +to work with an artist how to work with + + align:start position:0% +to work with an artist how to work with + + + align:start position:0% +to work with an artist how to work with +a sound designer what it actually means + + align:start position:0% +a sound designer what it actually means + + + align:start position:0% +a sound designer what it actually means +to be an art director in a in a game + + align:start position:0% +to be an art director in a in a game + + + align:start position:0% +to be an art director in a in a game +company or what it actually doesn't mean + + align:start position:0% +company or what it actually doesn't mean + + + align:start position:0% +company or what it actually doesn't mean +to even be a level designer um on a on a + + align:start position:0% +to even be a level designer um on a on a + + + align:start position:0% +to even be a level designer um on a on a +large project um but then Al we're + + align:start position:0% +large project um but then Al we're + + + align:start position:0% +large project um but then Al we're +bringing people in to talk about + + align:start position:0% +bringing people in to talk about + + + align:start position:0% +bringing people in to talk about +business models um Kickstarter is often + + align:start position:0% +business models um Kickstarter is often + + + align:start position:0% +business models um Kickstarter is often +an interesting topic for the students + + align:start position:0% +an interesting topic for the students + + + align:start position:0% +an interesting topic for the students +things we try to balance it between + + align:start position:0% +things we try to balance it between + + + align:start position:0% +things we try to balance it between +here's what the industry looks like and + + align:start position:0% +here's what the industry looks like and + + + align:start position:0% +here's what the industry looks like and +here's the things are going to help you + + align:start position:0% +here's the things are going to help you + + + align:start position:0% +here's the things are going to help you +right now with the the the game that + + align:start position:0% +right now with the the the game that + + + align:start position:0% +right now with the the the game that +you're working on now and if you wanted + + align:start position:0% +you're working on now and if you wanted + + + align:start position:0% +you're working on now and if you wanted +to take the game a little bit further + + align:start position:0% +to take the game a little bit further + + + align:start position:0% +to take the game a little bit further +after the course here's the things that + + align:start position:0% +after the course here's the things that + + + align:start position:0% +after the course here's the things that +you could do um things like fundraising + + align:start position:0% +you could do um things like fundraising + + + align:start position:0% +you could do um things like fundraising +um submitting it to festivals um + + align:start position:0% +um submitting it to festivals um + + + align:start position:0% +um submitting it to festivals um +marketing it and things and just getting + + align:start position:0% +marketing it and things and just getting + + + align:start position:0% +marketing it and things and just getting +other people to play it \ No newline at end of file diff --git a/mrvBnZIEsZY.txt b/mrvBnZIEsZY.txt new file mode 100644 index 0000000000000000000000000000000000000000..2403fa6e1b2855474db091fded1975bfba08fc2c --- /dev/null +++ b/mrvBnZIEsZY.txt @@ -0,0 +1,323 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT open courseware continue + + align:start position:0% +will help MIT open courseware continue + + + align:start position:0% +will help MIT open courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free to make a donation or + + align:start position:0% +resources for free to make a donation or + + + align:start position:0% +resources for free to make a donation or +view additional materials from hundreds + + align:start position:0% +view additional materials from hundreds + + + align:start position:0% +view additional materials from hundreds +of MIT courses visit MIT opencourseware + + align:start position:0% +of MIT courses visit MIT opencourseware + + + align:start position:0% +of MIT courses visit MIT opencourseware +at + + align:start position:0% + + + + align:start position:0% + +ocw.mit.edu so now we have this this + + align:start position:0% +ocw.mit.edu so now we have this this + + + align:start position:0% +ocw.mit.edu so now we have this this +last + + align:start position:0% +last + + + align:start position:0% +last +exercise I'm creating a my sum I'm going + + align:start position:0% +exercise I'm creating a my sum I'm going + + + align:start position:0% +exercise I'm creating a my sum I'm going +to go through all of these values and + + align:start position:0% +to go through all of these values and + + + align:start position:0% +to go through all of these values and +you guys have already told me what + + align:start position:0% +you guys have already told me what + + + align:start position:0% +you guys have already told me what +values these are 5 7 9 not + + align:start position:0% +values these are 5 7 9 not + + + align:start position:0% +values these are 5 7 9 not +11 and I'm going to add to my sum so I'm + + align:start position:0% +11 and I'm going to add to my sum so I'm + + + align:start position:0% +11 and I'm going to add to my sum so I'm +going to keep a running sum adding all + + align:start position:0% +going to keep a running sum adding all + + + align:start position:0% +going to keep a running sum adding all +of these values together + + align:start position:0% +of these values together + + + align:start position:0% +of these values together +okay so the very first time through the + + align:start position:0% +okay so the very first time through the + + + align:start position:0% +okay so the very first time through the +loop my sum gets the value of + + align:start position:0% +loop my sum gets the value of + + + align:start position:0% +loop my sum gets the value of +five okay that's this line here the next + + align:start position:0% +five okay that's this line here the next + + + align:start position:0% +five okay that's this line here the next +thing I'm I see inside this Loop is an + + align:start position:0% +thing I'm I see inside this Loop is an + + + align:start position:0% +thing I'm I see inside this Loop is an +if statement if my sum is equal to five + + align:start position:0% +if statement if my sum is equal to five + + + align:start position:0% +if statement if my sum is equal to five +that's + + align:start position:0% +that's + + + align:start position:0% +that's +true so I'm going to go inside this if + + align:start position:0% +true so I'm going to go inside this if + + + align:start position:0% +true so I'm going to go inside this if +statement the next thing I see is a + + align:start position:0% + + + + align:start position:0% + +break if I see this break am I + + align:start position:0% +break if I see this break am I + + + align:start position:0% +break if I see this break am I +evaluating this am I evaluating this + + align:start position:0% +evaluating this am I evaluating this + + + align:start position:0% +evaluating this am I evaluating this +line or + + align:start position:0% +line or + + + align:start position:0% +line or +not no exactly because when whenever + + align:start position:0% +not no exactly because when whenever + + + align:start position:0% +not no exactly because when whenever +python sees break it's going to say I'm + + align:start position:0% +python sees break it's going to say I'm + + + align:start position:0% +python sees break it's going to say I'm +going to stop right here exit out of the + + align:start position:0% +going to stop right here exit out of the + + + align:start position:0% +going to stop right here exit out of the +loop that I'm currently in and go to the + + align:start position:0% +loop that I'm currently in and go to the + + + align:start position:0% +loop that I'm currently in and go to the +statement that's immediately right after + + align:start position:0% +statement that's immediately right after + + + align:start position:0% +statement that's immediately right after +it so what this is going to print is my + + align:start position:0% +it so what this is going to print is my + + + align:start position:0% +it so what this is going to print is my +sum and that's the exercise we were + + align:start position:0% +sum and that's the exercise we were + + + align:start position:0% +sum and that's the exercise we were +looking at let's see how the class + + align:start position:0% +looking at let's see how the class + + + align:start position:0% +looking at let's see how the class +did pretty + + align:start position:0% + + + + align:start position:0% + +good hopefully if you answered one of + + align:start position:0% +good hopefully if you answered one of + + + align:start position:0% +good hopefully if you answered one of +these um the explanation was was all + + align:start position:0% +these um the explanation was was all + + + align:start position:0% +these um the explanation was was all +right if not just go back and try to + + align:start position:0% +right if not just go back and try to + + + align:start position:0% +right if not just go back and try to +work through it step by step \ No newline at end of file diff --git a/nwZ9FbZtOv0.txt b/nwZ9FbZtOv0.txt new file mode 100644 index 0000000000000000000000000000000000000000..085a988b51bdc4383cf1aa1767dd19897d11c93c --- /dev/null +++ b/nwZ9FbZtOv0.txt @@ -0,0 +1,3024 @@ +align:start position:0% + +n2o5 is a reagent that was used to + + align:start position:0% +n2o5 is a reagent that was used to + + + align:start position:0% +n2o5 is a reagent that was used to +synthesize explosives like tnt + + align:start position:0% +synthesize explosives like tnt + + + align:start position:0% +synthesize explosives like tnt +unfortunately it decomposes relatively + + align:start position:0% +unfortunately it decomposes relatively + + + align:start position:0% +unfortunately it decomposes relatively +quickly at or above room temperature + + align:start position:0% +quickly at or above room temperature + + + align:start position:0% +quickly at or above room temperature +so if you accidentally leave a bottle of + + align:start position:0% +so if you accidentally leave a bottle of + + + align:start position:0% +so if you accidentally leave a bottle of +it out on the counter you could be in + + align:start position:0% +it out on the counter you could be in + + + align:start position:0% +it out on the counter you could be in +trouble + + align:start position:0% +trouble + + + align:start position:0% +trouble +in this video we'll approximate the + + align:start position:0% +in this video we'll approximate the + + + align:start position:0% +in this video we'll approximate the +decomposition rate equation + + align:start position:0% +decomposition rate equation + + + align:start position:0% +decomposition rate equation +to figure out whether a batch of n2o5 + + align:start position:0% +to figure out whether a batch of n2o5 + + + align:start position:0% +to figure out whether a batch of n2o5 +that you left at room temperature can + + align:start position:0% +that you left at room temperature can + + + align:start position:0% +that you left at room temperature can +still be used + + align:start position:0% +still be used + + + align:start position:0% +still be used +we'll also determine under what + + align:start position:0% +we'll also determine under what + + + align:start position:0% +we'll also determine under what +conditions our approximation + + align:start position:0% +conditions our approximation + + + align:start position:0% +conditions our approximation +is valid this video is part of the + + align:start position:0% +is valid this video is part of the + + + align:start position:0% +is valid this video is part of the +linearity video series + + align:start position:0% +linearity video series + + + align:start position:0% +linearity video series +many complex systems are modeled or + + align:start position:0% +many complex systems are modeled or + + + align:start position:0% +many complex systems are modeled or +approximated linearly because of the + + align:start position:0% +approximated linearly because of the + + + align:start position:0% +approximated linearly because of the +mathematical advantages + + align:start position:0% +mathematical advantages + + + align:start position:0% +mathematical advantages +hi my name is ben brubacher and i'm a + + align:start position:0% +hi my name is ben brubacher and i'm a + + + align:start position:0% +hi my name is ben brubacher and i'm a +professor in the department of + + align:start position:0% +professor in the department of + + + align:start position:0% +professor in the department of +mathematics at mit + + align:start position:0% +mathematics at mit + + + align:start position:0% +mathematics at mit +today we'll be talking about linear + + align:start position:0% +today we'll be talking about linear + + + align:start position:0% +today we'll be talking about linear +approximations + + align:start position:0% +approximations + + + align:start position:0% +approximations +in mathematical terms this is just + + align:start position:0% +in mathematical terms this is just + + + align:start position:0% +in mathematical terms this is just +another name for the tangent line to a + + align:start position:0% +another name for the tangent line to a + + + align:start position:0% +another name for the tangent line to a +function + + align:start position:0% +function + + + align:start position:0% +function +but the name suggests more linear + + align:start position:0% +but the name suggests more linear + + + align:start position:0% +but the name suggests more linear +approximations can be used to simplify + + align:start position:0% +approximations can be used to simplify + + + align:start position:0% +approximations can be used to simplify +mathematical models that are not + + align:start position:0% +mathematical models that are not + + + align:start position:0% +mathematical models that are not +analytically solvable + + align:start position:0% +analytically solvable + + + align:start position:0% +analytically solvable +the approximated model will have a + + align:start position:0% +the approximated model will have a + + + align:start position:0% +the approximated model will have a +solution that is only acceptable under + + align:start position:0% +solution that is only acceptable under + + + align:start position:0% +solution that is only acceptable under +suitable conditions + + align:start position:0% +suitable conditions + + + align:start position:0% +suitable conditions +however it can still illuminate the + + align:start position:0% +however it can still illuminate the + + + align:start position:0% +however it can still illuminate the +behavior of a system + + align:start position:0% +behavior of a system + + + align:start position:0% +behavior of a system +within a certain acceptable range + + align:start position:0% +within a certain acceptable range + + + align:start position:0% +within a certain acceptable range +before watching this video you should + + align:start position:0% +before watching this video you should + + + align:start position:0% +before watching this video you should +know the definition of the derivative + + align:start position:0% +know the definition of the derivative + + + align:start position:0% +know the definition of the derivative +and how to write the equation of a line + + align:start position:0% +and how to write the equation of a line + + + align:start position:0% +and how to write the equation of a line +with a given slope that passes through a + + align:start position:0% +with a given slope that passes through a + + + align:start position:0% +with a given slope that passes through a +given point + + align:start position:0% +given point + + + align:start position:0% +given point +after watching this video you should be + + align:start position:0% +after watching this video you should be + + + align:start position:0% +after watching this video you should be +able to recognize the linear + + align:start position:0% +able to recognize the linear + + + align:start position:0% +able to recognize the linear +approximation of a function + + align:start position:0% +approximation of a function + + + align:start position:0% +approximation of a function +as the tangent line to the function + + align:start position:0% +as the tangent line to the function + + + align:start position:0% +as the tangent line to the function +apply linear approximations to solve + + align:start position:0% +apply linear approximations to solve + + + align:start position:0% +apply linear approximations to solve +simple differential equations + + align:start position:0% +simple differential equations + + + align:start position:0% +simple differential equations +and explain the limitations of linear + + align:start position:0% +and explain the limitations of linear + + + align:start position:0% +and explain the limitations of linear +approximations both mathematically and + + align:start position:0% +approximations both mathematically and + + + align:start position:0% +approximations both mathematically and +graphically + + align:start position:0% +graphically + + + align:start position:0% +graphically +let's begin by defining the linear + + align:start position:0% +let's begin by defining the linear + + + align:start position:0% +let's begin by defining the linear +approximation + + align:start position:0% + + + + align:start position:0% + +recall that if a function is + + align:start position:0% +recall that if a function is + + + align:start position:0% +recall that if a function is +differentiable at a point c + + align:start position:0% +differentiable at a point c + + + align:start position:0% +differentiable at a point c +then when we zoom in on the point c the + + align:start position:0% +then when we zoom in on the point c the + + + align:start position:0% +then when we zoom in on the point c the +function begins to look more and more + + align:start position:0% +function begins to look more and more + + + align:start position:0% +function begins to look more and more +like a line + + align:start position:0% +like a line + + + align:start position:0% +like a line +this only works when the function is + + align:start position:0% +this only works when the function is + + + align:start position:0% +this only works when the function is +smooth it doesn't have any kinks + + align:start position:0% +smooth it doesn't have any kinks + + + align:start position:0% +smooth it doesn't have any kinks +corners or discontinuities + + align:start position:0% +corners or discontinuities + + + align:start position:0% +corners or discontinuities +given a function f of x which is + + align:start position:0% +given a function f of x which is + + + align:start position:0% +given a function f of x which is +differentiable at the point c + + align:start position:0% +differentiable at the point c + + + align:start position:0% +differentiable at the point c +we define the linear approximation to be + + align:start position:0% +we define the linear approximation to be + + + align:start position:0% +we define the linear approximation to be +the tangent line to the function at c + + align:start position:0% +the tangent line to the function at c + + + align:start position:0% +the tangent line to the function at c +this is the line whose slope + + align:start position:0% +this is the line whose slope + + + align:start position:0% +this is the line whose slope +equals f prime of c the derivative of f + + align:start position:0% +equals f prime of c the derivative of f + + + align:start position:0% +equals f prime of c the derivative of f +at c + + align:start position:0% +at c + + + align:start position:0% +at c +as an example let's look at the + + align:start position:0% +as an example let's look at the + + + align:start position:0% +as an example let's look at the +following cubic equation + + align:start position:0% +following cubic equation + + + align:start position:0% +following cubic equation +f of x is 1 30th x + + align:start position:0% +f of x is 1 30th x + + + align:start position:0% +f of x is 1 30th x +times x minus 2 times x plus 5. + + align:start position:0% +times x minus 2 times x plus 5. + + + align:start position:0% +times x minus 2 times x plus 5. +this function is differentiable + + align:start position:0% +this function is differentiable + + + align:start position:0% +this function is differentiable +everywhere and so in particular + + align:start position:0% +everywhere and so in particular + + + align:start position:0% +everywhere and so in particular +it's differentiable at the point x + + align:start position:0% +it's differentiable at the point x + + + align:start position:0% +it's differentiable at the point x +equals 3. + + align:start position:0% +equals 3. + + + align:start position:0% +equals 3. +find the equation of the tangent line to + + align:start position:0% +find the equation of the tangent line to + + + align:start position:0% +find the equation of the tangent line to +this cubic equation + + align:start position:0% +this cubic equation + + + align:start position:0% +this cubic equation +at x equals 3 for yourself + + align:start position:0% + + + + align:start position:0% + +in the meanwhile we've also found the + + align:start position:0% +in the meanwhile we've also found the + + + align:start position:0% +in the meanwhile we've also found the +equation for the tangent line + + align:start position:0% +equation for the tangent line + + + align:start position:0% +equation for the tangent line +to do this we found the value of the + + align:start position:0% +to do this we found the value of the + + + align:start position:0% +to do this we found the value of the +function at 3 which we found to be + + align:start position:0% +function at 3 which we found to be + + + align:start position:0% +function at 3 which we found to be +four-fifths + + align:start position:0% +four-fifths + + + align:start position:0% +four-fifths +and then we computed the derivative and + + align:start position:0% +and then we computed the derivative and + + + align:start position:0% +and then we computed the derivative and +evaluated it at x + + align:start position:0% +evaluated it at x + + + align:start position:0% +evaluated it at x +equals 3 which we found to be 7 6. + + align:start position:0% +equals 3 which we found to be 7 6. + + + align:start position:0% +equals 3 which we found to be 7 6. +we'll write the tangent line as t sub 3 + + align:start position:0% +we'll write the tangent line as t sub 3 + + + align:start position:0% +we'll write the tangent line as t sub 3 +of x to remind + + align:start position:0% +of x to remind + + + align:start position:0% +of x to remind +us that we are finding the tangent to + + align:start position:0% +us that we are finding the tangent to + + + align:start position:0% +us that we are finding the tangent to +our function at the point three + + align:start position:0% +our function at the point three + + + align:start position:0% +our function at the point three +then the equation for the line can be + + align:start position:0% +then the equation for the line can be + + + align:start position:0% +then the equation for the line can be +written as t sub three of x + + align:start position:0% +written as t sub three of x + + + align:start position:0% +written as t sub three of x +equals four fifths plus seven sixths + + align:start position:0% +equals four fifths plus seven sixths + + + align:start position:0% +equals four fifths plus seven sixths +times x minus three + + align:start position:0% +times x minus three + + + align:start position:0% +times x minus three +let's take a look at the graphs of f of + + align:start position:0% +let's take a look at the graphs of f of + + + align:start position:0% +let's take a look at the graphs of f of +x and t sub 3 of x + + align:start position:0% +x and t sub 3 of x + + + align:start position:0% +x and t sub 3 of x +the function f x is graphed in red the + + align:start position:0% +the function f x is graphed in red the + + + align:start position:0% +the function f x is graphed in red the +further we zoom into the graph at x + + align:start position:0% +further we zoom into the graph at x + + + align:start position:0% +further we zoom into the graph at x +equals 3 the more it begins to resemble + + align:start position:0% +equals 3 the more it begins to resemble + + + align:start position:0% +equals 3 the more it begins to resemble +a straight line + + align:start position:0% +a straight line + + + align:start position:0% +a straight line +the slope of the line approaches the + + align:start position:0% +the slope of the line approaches the + + + align:start position:0% +the slope of the line approaches the +value of the slope at the tangent line + + align:start position:0% +value of the slope at the tangent line + + + align:start position:0% +value of the slope at the tangent line +at 3 + + align:start position:0% +at 3 + + + align:start position:0% +at 3 +which is drawn in blue + + align:start position:0% + + + + align:start position:0% + +the tangent line certainly seems to be a + + align:start position:0% +the tangent line certainly seems to be a + + + align:start position:0% +the tangent line certainly seems to be a +good approximation to our function when + + align:start position:0% +good approximation to our function when + + + align:start position:0% +good approximation to our function when +we are close to x equals 3 + + align:start position:0% +we are close to x equals 3 + + + align:start position:0% +we are close to x equals 3 +but what about when we zoom out is it + + align:start position:0% +but what about when we zoom out is it + + + align:start position:0% +but what about when we zoom out is it +still a good approximation + + align:start position:0% +still a good approximation + + + align:start position:0% +still a good approximation +let's give a mathematical justification + + align:start position:0% +let's give a mathematical justification + + + align:start position:0% +let's give a mathematical justification +that the tangent line + + align:start position:0% +that the tangent line + + + align:start position:0% +that the tangent line +is a good approximation our function is + + align:start position:0% +is a good approximation our function is + + + align:start position:0% +is a good approximation our function is +differentiable at a point say + + align:start position:0% +differentiable at a point say + + + align:start position:0% +differentiable at a point say +x equals 3. this is equivalent to the + + align:start position:0% +x equals 3. this is equivalent to the + + + align:start position:0% +x equals 3. this is equivalent to the +statement that when x is near 3 + + align:start position:0% +statement that when x is near 3 + + + align:start position:0% +statement that when x is near 3 +the slope of the secant line is + + align:start position:0% +the slope of the secant line is + + + align:start position:0% +the slope of the secant line is +approximately equal + + align:start position:0% +approximately equal + + + align:start position:0% +approximately equal +to the slope of the tangent line that is + + align:start position:0% +to the slope of the tangent line that is + + + align:start position:0% +to the slope of the tangent line that is +for x near 3 f of x minus f of 3 + + align:start position:0% +for x near 3 f of x minus f of 3 + + + align:start position:0% +for x near 3 f of x minus f of 3 +divided by x minus 3 is approximately + + align:start position:0% +divided by x minus 3 is approximately + + + align:start position:0% +divided by x minus 3 is approximately +equal to the value of the derivative at + + align:start position:0% +equal to the value of the derivative at + + + align:start position:0% +equal to the value of the derivative at +3. + + align:start position:0% +3. + + + align:start position:0% +3. +in order to see why these statements are + + align:start position:0% +in order to see why these statements are + + + align:start position:0% +in order to see why these statements are +equivalent we need to explain + + align:start position:0% +equivalent we need to explain + + + align:start position:0% +equivalent we need to explain +what we mean by approximately equal to + + align:start position:0% +what we mean by approximately equal to + + + align:start position:0% +what we mean by approximately equal to +this means that we can make the + + align:start position:0% +this means that we can make the + + + align:start position:0% +this means that we can make the +difference between these two sides as + + align:start position:0% +difference between these two sides as + + + align:start position:0% +difference between these two sides as +small as any error bound we choose + + align:start position:0% +small as any error bound we choose + + + align:start position:0% +small as any error bound we choose +provided that we choose x close enough + + align:start position:0% +provided that we choose x close enough + + + align:start position:0% +provided that we choose x close enough +to three + + align:start position:0% + + + + align:start position:0% + +and this is exactly the definition of + + align:start position:0% +and this is exactly the definition of + + + align:start position:0% +and this is exactly the definition of +differentiability at the point three + + align:start position:0% + + + + align:start position:0% + +to relate all of this to linear + + align:start position:0% +to relate all of this to linear + + + align:start position:0% +to relate all of this to linear +approximations we use a bit of algebra + + align:start position:0% +approximations we use a bit of algebra + + + align:start position:0% +approximations we use a bit of algebra +first we multiply both sides by x minus + + align:start position:0% +first we multiply both sides by x minus + + + align:start position:0% +first we multiply both sides by x minus + + align:start position:0% + + + align:start position:0% +and we get f of x minus f of 3 + + align:start position:0% +and we get f of x minus f of 3 + + + align:start position:0% +and we get f of x minus f of 3 +approximately equal to f prime of 3 + + align:start position:0% +approximately equal to f prime of 3 + + + align:start position:0% +approximately equal to f prime of 3 +times x minus 3. + + align:start position:0% +times x minus 3. + + + align:start position:0% +times x minus 3. +adding f of 3 to both sides we get that + + align:start position:0% +adding f of 3 to both sides we get that + + + align:start position:0% +adding f of 3 to both sides we get that +f of x is approximately equal to f + + align:start position:0% +f of x is approximately equal to f + + + align:start position:0% +f of x is approximately equal to f +of 3 plus f prime of 3 times + + align:start position:0% +of 3 plus f prime of 3 times + + + align:start position:0% +of 3 plus f prime of 3 times +x minus 3. and this right hand side + + align:start position:0% +x minus 3. and this right hand side + + + align:start position:0% +x minus 3. and this right hand side +is then the equation for the tangent + + align:start position:0% +is then the equation for the tangent + + + align:start position:0% +is then the equation for the tangent +line at three + + align:start position:0% +line at three + + + align:start position:0% +line at three +so indeed the tangent line closely + + align:start position:0% +so indeed the tangent line closely + + + align:start position:0% +so indeed the tangent line closely +approximates the function + + align:start position:0% +approximates the function + + + align:start position:0% +approximates the function +as long as x is close to three + + align:start position:0% + + + + align:start position:0% + +here we see the tangent line drawn in + + align:start position:0% +here we see the tangent line drawn in + + + align:start position:0% +here we see the tangent line drawn in +blue the function drawn in red the + + align:start position:0% +blue the function drawn in red the + + + align:start position:0% +blue the function drawn in red the +graphs demonstrate our mathematical + + align:start position:0% +graphs demonstrate our mathematical + + + align:start position:0% +graphs demonstrate our mathematical +proof + + align:start position:0% +proof + + + align:start position:0% +proof +that a tangent line is a good + + align:start position:0% +that a tangent line is a good + + + align:start position:0% +that a tangent line is a good +approximation near x equals three + + align:start position:0% +approximation near x equals three + + + align:start position:0% +approximation near x equals three +but the further we get from x equals + + align:start position:0% +but the further we get from x equals + + + align:start position:0% +but the further we get from x equals +three the worse the approximation + + align:start position:0% +three the worse the approximation + + + align:start position:0% +three the worse the approximation +seems you might have noticed that the + + align:start position:0% +seems you might have noticed that the + + + align:start position:0% +seems you might have noticed that the +function and the tangent line intersect + + align:start position:0% +function and the tangent line intersect + + + align:start position:0% +function and the tangent line intersect +at x equals minus nine + + align:start position:0% +at x equals minus nine + + + align:start position:0% +at x equals minus nine +is the tangent line a good approximation + + align:start position:0% +is the tangent line a good approximation + + + align:start position:0% +is the tangent line a good approximation +for the function near x + + align:start position:0% +for the function near x + + + align:start position:0% +for the function near x +equals minus nine + + align:start position:0% + + + + align:start position:0% + +no it isn't if we move a small distance + + align:start position:0% +no it isn't if we move a small distance + + + align:start position:0% +no it isn't if we move a small distance +along the tangent line away from x + + align:start position:0% +along the tangent line away from x + + + align:start position:0% +along the tangent line away from x +equals minus nine + + align:start position:0% +equals minus nine + + + align:start position:0% +equals minus nine +this does not model the behavior of the + + align:start position:0% +this does not model the behavior of the + + + align:start position:0% +this does not model the behavior of the +function near x equals minus nine + + align:start position:0% +function near x equals minus nine + + + align:start position:0% +function near x equals minus nine +this property is extremely important in + + align:start position:0% +this property is extremely important in + + + align:start position:0% +this property is extremely important in +applications + + align:start position:0% +applications + + + align:start position:0% +applications +no measurement or observed quantity is + + align:start position:0% +no measurement or observed quantity is + + + align:start position:0% +no measurement or observed quantity is +ever given exactly + + align:start position:0% +ever given exactly + + + align:start position:0% +ever given exactly +the linearization of a function that is + + align:start position:0% +the linearization of a function that is + + + align:start position:0% +the linearization of a function that is +differentiable at x + + align:start position:0% +differentiable at x + + + align:start position:0% +differentiable at x +equals c is just another name for the + + align:start position:0% +equals c is just another name for the + + + align:start position:0% +equals c is just another name for the +tangent line through c + + align:start position:0% +tangent line through c + + + align:start position:0% +tangent line through c +the key properties of this tangent line + + align:start position:0% +the key properties of this tangent line + + + align:start position:0% +the key properties of this tangent line +are that it shares the same value + + align:start position:0% +are that it shares the same value + + + align:start position:0% +are that it shares the same value +as the function and the same first + + align:start position:0% +as the function and the same first + + + align:start position:0% +as the function and the same first +derivative of the function at x equals c + + align:start position:0% +derivative of the function at x equals c + + + align:start position:0% +derivative of the function at x equals c +and we've seen through both graphical + + align:start position:0% +and we've seen through both graphical + + + align:start position:0% +and we've seen through both graphical +intuition and the definition of the + + align:start position:0% +intuition and the definition of the + + + align:start position:0% +intuition and the definition of the +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +that this linearization closely + + align:start position:0% +that this linearization closely + + + align:start position:0% +that this linearization closely +approximates the function for points x + + align:start position:0% +approximates the function for points x + + + align:start position:0% +approximates the function for points x +sufficiently close to c let's see how we + + align:start position:0% +sufficiently close to c let's see how we + + + align:start position:0% +sufficiently close to c let's see how we +can apply a linear approximation + + align:start position:0% +can apply a linear approximation + + + align:start position:0% +can apply a linear approximation +to simplify a problem + + align:start position:0% +to simplify a problem + + + align:start position:0% +to simplify a problem +let's suppose you are participating in + + align:start position:0% +let's suppose you are participating in + + + align:start position:0% +let's suppose you are participating in +undergraduate research + + align:start position:0% +undergraduate research + + + align:start position:0% +undergraduate research +in a chemistry lab you've been using a + + align:start position:0% +in a chemistry lab you've been using a + + + align:start position:0% +in a chemistry lab you've been using a +.01 molar solution of n2o5 + + align:start position:0% +.01 molar solution of n2o5 + + + align:start position:0% +.01 molar solution of n2o5 +and you bring it out of the refrigerator + + align:start position:0% +and you bring it out of the refrigerator + + + align:start position:0% +and you bring it out of the refrigerator +at 9 00 am monday morning + + align:start position:0% +at 9 00 am monday morning + + + align:start position:0% +at 9 00 am monday morning +and promptly forget about it leaving it + + align:start position:0% +and promptly forget about it leaving it + + + align:start position:0% +and promptly forget about it leaving it +on the counter in the lab + + align:start position:0% +on the counter in the lab + + + align:start position:0% +on the counter in the lab +which is 25 degrees celsius when you + + align:start position:0% +which is 25 degrees celsius when you + + + align:start position:0% +which is 25 degrees celsius when you +realize you left the solution out + + align:start position:0% +realize you left the solution out + + + align:start position:0% +realize you left the solution out +one hour has passed you panic + + align:start position:0% +one hour has passed you panic + + + align:start position:0% +one hour has passed you panic +the problem is that n2o5 decomposes into + + align:start position:0% +the problem is that n2o5 decomposes into + + + align:start position:0% +the problem is that n2o5 decomposes into +no2 + + align:start position:0% +no2 + + + align:start position:0% +no2 +and o2 at room temperature if the + + align:start position:0% +and o2 at room temperature if the + + + align:start position:0% +and o2 at room temperature if the +molarity of the solution has changed + + align:start position:0% +molarity of the solution has changed + + + align:start position:0% +molarity of the solution has changed +significantly + + align:start position:0% +significantly + + + align:start position:0% +significantly +it might ruin your experiments + + align:start position:0% +it might ruin your experiments + + + align:start position:0% +it might ruin your experiments +experiments have shown that the rate of + + align:start position:0% +experiments have shown that the rate of + + + align:start position:0% +experiments have shown that the rate of +decomposition follows first order + + align:start position:0% +decomposition follows first order + + + align:start position:0% +decomposition follows first order +kinetics + + align:start position:0% +kinetics + + + align:start position:0% +kinetics +this means that the instantaneous rate + + align:start position:0% +this means that the instantaneous rate + + + align:start position:0% +this means that the instantaneous rate +of change in concentration of n2o5 + + align:start position:0% +of change in concentration of n2o5 + + + align:start position:0% +of change in concentration of n2o5 +is proportional to the concentration of + + align:start position:0% +is proportional to the concentration of + + + align:start position:0% +is proportional to the concentration of +n2o5 + + align:start position:0% +n2o5 + + + align:start position:0% +n2o5 +the constant of proportionality k has + + align:start position:0% +the constant of proportionality k has + + + align:start position:0% +the constant of proportionality k has +been found experimentally + + align:start position:0% +been found experimentally + + + align:start position:0% +been found experimentally +to be 1.72 times 10 to the negative + + align:start position:0% +to be 1.72 times 10 to the negative + + + align:start position:0% +to be 1.72 times 10 to the negative +5 inverse seconds + + align:start position:0% + + + + align:start position:0% + +because you're panicking you're having a + + align:start position:0% +because you're panicking you're having a + + + align:start position:0% +because you're panicking you're having a +hard time solving this differential + + align:start position:0% +hard time solving this differential + + + align:start position:0% +hard time solving this differential +equation + + align:start position:0% +equation + + + align:start position:0% +equation +instead find the approximate + + align:start position:0% +instead find the approximate + + + align:start position:0% +instead find the approximate +decomposition in the n2o5 + + align:start position:0% +decomposition in the n2o5 + + + align:start position:0% +decomposition in the n2o5 +solution after one hour using a linear + + align:start position:0% +solution after one hour using a linear + + + align:start position:0% +solution after one hour using a linear +approximation at time + + align:start position:0% +approximation at time + + + align:start position:0% +approximation at time +t equals zero note that because the + + align:start position:0% +t equals zero note that because the + + + align:start position:0% +t equals zero note that because the +reaction constant has units of inverse + + align:start position:0% +reaction constant has units of inverse + + + align:start position:0% +reaction constant has units of inverse +seconds + + align:start position:0% +seconds + + + align:start position:0% +seconds +the variable t must have units of + + align:start position:0% +the variable t must have units of + + + align:start position:0% +the variable t must have units of +seconds + + align:start position:0% + + + + align:start position:0% + +in order to produce a linear + + align:start position:0% +in order to produce a linear + + + align:start position:0% +in order to produce a linear +approximation at t equals zero + + align:start position:0% +approximation at t equals zero + + + align:start position:0% +approximation at t equals zero +we need two ingredients the + + align:start position:0% +we need two ingredients the + + + align:start position:0% +we need two ingredients the +concentration + + align:start position:0% +concentration + + + align:start position:0% +concentration +at time zero and the value of the + + align:start position:0% +at time zero and the value of the + + + align:start position:0% +at time zero and the value of the +derivative at time + + align:start position:0% +derivative at time + + + align:start position:0% +derivative at time +0. the initial concentration + + align:start position:0% +0. the initial concentration + + + align:start position:0% +0. the initial concentration +was .01 molar to find the value of the + + align:start position:0% +was .01 molar to find the value of the + + + align:start position:0% +was .01 molar to find the value of the +derivative + + align:start position:0% +derivative + + + align:start position:0% +derivative +we use our differential equation and we + + align:start position:0% +we use our differential equation and we + + + align:start position:0% +we use our differential equation and we +find that the value of the derivative + + align:start position:0% +find that the value of the derivative + + + align:start position:0% +find that the value of the derivative +at time t equals 0 is just minus k + + align:start position:0% +at time t equals 0 is just minus k + + + align:start position:0% +at time t equals 0 is just minus k +times the initial concentration at t + + align:start position:0% +times the initial concentration at t + + + align:start position:0% +times the initial concentration at t +equals 0 + + align:start position:0% +equals 0 + + + align:start position:0% +equals 0 +or negative k times 0.01 molar + + align:start position:0% +or negative k times 0.01 molar + + + align:start position:0% +or negative k times 0.01 molar +remember that k has units of inverse + + align:start position:0% +remember that k has units of inverse + + + align:start position:0% +remember that k has units of inverse +seconds + + align:start position:0% +seconds + + + align:start position:0% +seconds +putting this all together into the + + align:start position:0% +putting this all together into the + + + align:start position:0% +putting this all together into the +formula for the tangent line at 0 + + align:start position:0% +formula for the tangent line at 0 + + + align:start position:0% +formula for the tangent line at 0 +we see that the linear approximation is + + align:start position:0% +we see that the linear approximation is + + + align:start position:0% +we see that the linear approximation is +given by + + align:start position:0% +given by + + + align:start position:0% +given by +t 0 of t is .01 molar times + + align:start position:0% +t 0 of t is .01 molar times + + + align:start position:0% +t 0 of t is .01 molar times +1 minus kt + + align:start position:0% + + + + align:start position:0% + +now we're interested in approximating + + align:start position:0% +now we're interested in approximating + + + align:start position:0% +now we're interested in approximating +the value at 1 hour or + + align:start position:0% +the value at 1 hour or + + + align:start position:0% +the value at 1 hour or +3 600 seconds plugging in the value for + + align:start position:0% +3 600 seconds plugging in the value for + + + align:start position:0% +3 600 seconds plugging in the value for +k + + align:start position:0% +k + + + align:start position:0% +k +we find that to two significant figures + + align:start position:0% +we find that to two significant figures + + + align:start position:0% +we find that to two significant figures +t + + align:start position:0% +t + + + align:start position:0% +t +zero at thirty six hundred seconds + + align:start position:0% +zero at thirty six hundred seconds + + + align:start position:0% +zero at thirty six hundred seconds +equals point zero zero + + align:start position:0% +equals point zero zero + + + align:start position:0% +equals point zero zero +nine four molar so the molarity is not + + align:start position:0% +nine four molar so the molarity is not + + + align:start position:0% +nine four molar so the molarity is not +so different + + align:start position:0% +so different + + + align:start position:0% +so different +now you are feeling relieved so when you + + align:start position:0% +now you are feeling relieved so when you + + + align:start position:0% +now you are feeling relieved so when you +look back at the reaction rate + + align:start position:0% +look back at the reaction rate + + + align:start position:0% +look back at the reaction rate +you realize that in fact a first order + + align:start position:0% +you realize that in fact a first order + + + align:start position:0% +you realize that in fact a first order +reaction rate is telling you + + align:start position:0% +reaction rate is telling you + + + align:start position:0% +reaction rate is telling you +that the concentration is some function + + align:start position:0% +that the concentration is some function + + + align:start position:0% +that the concentration is some function +of time whose derivative is proportional + + align:start position:0% +of time whose derivative is proportional + + + align:start position:0% +of time whose derivative is proportional +to itself + + align:start position:0% + + + + align:start position:0% + +the function with this property is the + + align:start position:0% +the function with this property is the + + + align:start position:0% +the function with this property is the +exponential function + + align:start position:0% +exponential function + + + align:start position:0% +exponential function +so the concentration function is equal + + align:start position:0% +so the concentration function is equal + + + align:start position:0% +so the concentration function is equal +to some constant + + align:start position:0% +to some constant + + + align:start position:0% +to some constant +times e to the negative kt + + align:start position:0% +times e to the negative kt + + + align:start position:0% +times e to the negative kt +the constant must be the initial + + align:start position:0% +the constant must be the initial + + + align:start position:0% +the constant must be the initial +concentration which is 0.01 molar + + align:start position:0% +concentration which is 0.01 molar + + + align:start position:0% +concentration which is 0.01 molar +so the concentration of n2o5 at time t + + align:start position:0% +so the concentration of n2o5 at time t + + + align:start position:0% +so the concentration of n2o5 at time t +is equal to 0.01 times e to the negative + + align:start position:0% +is equal to 0.01 times e to the negative + + + align:start position:0% +is equal to 0.01 times e to the negative +kt + + align:start position:0% +kt + + + align:start position:0% +kt +evaluating this expression at time t + + align:start position:0% +evaluating this expression at time t + + + align:start position:0% +evaluating this expression at time t +equals 3600 + + align:start position:0% +equals 3600 + + + align:start position:0% +equals 3600 +we find that the exact concentration is + + align:start position:0% +we find that the exact concentration is + + + align:start position:0% +we find that the exact concentration is +also + + align:start position:0% +also + + + align:start position:0% +also +.0094 molar to two significant figures + + align:start position:0% +.0094 molar to two significant figures + + + align:start position:0% +.0094 molar to two significant figures +to be more precise we can look at the + + align:start position:0% +to be more precise we can look at the + + + align:start position:0% +to be more precise we can look at the +error which is the absolute value of the + + align:start position:0% +error which is the absolute value of the + + + align:start position:0% +error which is the absolute value of the +exact solution minus the approximate + + align:start position:0% +exact solution minus the approximate + + + align:start position:0% +exact solution minus the approximate +solution + + align:start position:0% +solution + + + align:start position:0% +solution +all divided by the value of the exact + + align:start position:0% +all divided by the value of the exact + + + align:start position:0% +all divided by the value of the exact +solution + + align:start position:0% +solution + + + align:start position:0% +solution +the error at time t equals 3 600 seconds + + align:start position:0% +the error at time t equals 3 600 seconds + + + align:start position:0% +the error at time t equals 3 600 seconds +is .002 or 0.2 percent + + align:start position:0% +is .002 or 0.2 percent + + + align:start position:0% +is .002 or 0.2 percent +this is really quite good generally + + align:start position:0% +this is really quite good generally + + + align:start position:0% +this is really quite good generally +speaking + + align:start position:0% +speaking + + + align:start position:0% +speaking +we might consider an error of less than + + align:start position:0% +we might consider an error of less than + + + align:start position:0% +we might consider an error of less than +five percent to be acceptable + + align:start position:0% + + + + align:start position:0% + +so our linear approximation was + + align:start position:0% +so our linear approximation was + + + align:start position:0% +so our linear approximation was +definitely within the acceptable range + + align:start position:0% +definitely within the acceptable range + + + align:start position:0% +definitely within the acceptable range +one hour later but now it's tuesday + + align:start position:0% +one hour later but now it's tuesday + + + align:start position:0% +one hour later but now it's tuesday +you leave the n205 on the counter for a + + align:start position:0% +you leave the n205 on the counter for a + + + align:start position:0% +you leave the n205 on the counter for a +full 10 hours + + align:start position:0% +full 10 hours + + + align:start position:0% +full 10 hours +curses we know that the exact solution + + align:start position:0% +curses we know that the exact solution + + + align:start position:0% +curses we know that the exact solution +is an exponential decay + + align:start position:0% + + + + align:start position:0% + +so do you think that the linear + + align:start position:0% +so do you think that the linear + + + align:start position:0% +so do you think that the linear +approximation will be an overestimate + + align:start position:0% +approximation will be an overestimate + + + align:start position:0% +approximation will be an overestimate +an underestimate or equal to the exact + + align:start position:0% +an underestimate or equal to the exact + + + align:start position:0% +an underestimate or equal to the exact +solution + + align:start position:0% +solution + + + align:start position:0% +solution +after 10 hours + + align:start position:0% + + + + align:start position:0% + +the linear approximation of the + + align:start position:0% +the linear approximation of the + + + align:start position:0% +the linear approximation of the +concentration after 10 hours + + align:start position:0% +concentration after 10 hours + + + align:start position:0% +concentration after 10 hours +at room temperature is t 0 of + + align:start position:0% +at room temperature is t 0 of + + + align:start position:0% +at room temperature is t 0 of +36 000 seconds equal to .0038 molar + + align:start position:0% +36 000 seconds equal to .0038 molar + + + align:start position:0% +36 000 seconds equal to .0038 molar +the exact solution of the concentration + + align:start position:0% +the exact solution of the concentration + + + align:start position:0% +the exact solution of the concentration +after 10 hours + + align:start position:0% +after 10 hours + + + align:start position:0% +after 10 hours +is .0054 molar + + align:start position:0% +is .0054 molar + + + align:start position:0% +is .0054 molar +comparing these two solutions we see + + align:start position:0% +comparing these two solutions we see + + + align:start position:0% +comparing these two solutions we see +that the linear approximation + + align:start position:0% +that the linear approximation + + + align:start position:0% +that the linear approximation +is an underestimate as we would expect + + align:start position:0% + + + + align:start position:0% + +the error is 0.29 or 29 percent + + align:start position:0% +the error is 0.29 or 29 percent + + + align:start position:0% +the error is 0.29 or 29 percent +so a linear approximation is definitely + + align:start position:0% +so a linear approximation is definitely + + + align:start position:0% +so a linear approximation is definitely +not acceptable + + align:start position:0% +not acceptable + + + align:start position:0% +not acceptable +for this time range + + align:start position:0% + + + + align:start position:0% + +but now you begin to wonder for what + + align:start position:0% +but now you begin to wonder for what + + + align:start position:0% +but now you begin to wonder for what +times is the linear approximation at t + + align:start position:0% +times is the linear approximation at t + + + align:start position:0% +times is the linear approximation at t +equals 0 within the 5 percent error of + + align:start position:0% +equals 0 within the 5 percent error of + + + align:start position:0% +equals 0 within the 5 percent error of +the exact solution + + align:start position:0% + + + + align:start position:0% + +because we are only interested in + + align:start position:0% +because we are only interested in + + + align:start position:0% +because we are only interested in +positive time values + + align:start position:0% +positive time values + + + align:start position:0% +positive time values +you should have found that the + + align:start position:0% +you should have found that the + + + align:start position:0% +you should have found that the +approximation is acceptable for positive + + align:start position:0% +approximation is acceptable for positive + + + align:start position:0% +approximation is acceptable for positive +times + + align:start position:0% +times + + + align:start position:0% +times +t less than 16 700 seconds which is + + align:start position:0% +t less than 16 700 seconds which is + + + align:start position:0% +t less than 16 700 seconds which is +about + + align:start position:0% +about + + + align:start position:0% +about +4.5 hours now that you've carefully + + align:start position:0% +4.5 hours now that you've carefully + + + align:start position:0% +4.5 hours now that you've carefully +examined this problem using linear + + align:start position:0% +examined this problem using linear + + + align:start position:0% +examined this problem using linear +approximation + + align:start position:0% +approximation + + + align:start position:0% +approximation +it's probably time to tell your graduate + + align:start position:0% +it's probably time to tell your graduate + + + align:start position:0% +it's probably time to tell your graduate +student advisor + + align:start position:0% +student advisor + + + align:start position:0% +student advisor +that you need to order a new batch of + + align:start position:0% +that you need to order a new batch of + + + align:start position:0% +that you need to order a new batch of +0.01 molar n2o5 + + align:start position:0% + + + + align:start position:0% + +let's review the linear approximation to + + align:start position:0% +let's review the linear approximation to + + + align:start position:0% +let's review the linear approximation to +a function at a point c + + align:start position:0% +a function at a point c + + + align:start position:0% +a function at a point c +is the tangent line of a function at c + + align:start position:0% +is the tangent line of a function at c + + + align:start position:0% +is the tangent line of a function at c +this linear approximation + + align:start position:0% +this linear approximation + + + align:start position:0% +this linear approximation +only accurately models the function for + + align:start position:0% +only accurately models the function for + + + align:start position:0% +only accurately models the function for +points sufficiently close to c + + align:start position:0% +points sufficiently close to c + + + align:start position:0% +points sufficiently close to c +it is easy to read off the derivative at + + align:start position:0% +it is easy to read off the derivative at + + + align:start position:0% +it is easy to read off the derivative at +a point + + align:start position:0% +a point + + + align:start position:0% +a point +from a differential equation and thus + + align:start position:0% +from a differential equation and thus + + + align:start position:0% +from a differential equation and thus +give a linear approximation to the + + align:start position:0% +give a linear approximation to the + + + align:start position:0% +give a linear approximation to the +solution + + align:start position:0% +solution + + + align:start position:0% +solution +in our example with the concentration of + + align:start position:0% +in our example with the concentration of + + + align:start position:0% +in our example with the concentration of +n2o5 + + align:start position:0% +n2o5 + + + align:start position:0% +n2o5 +we could also solve the differential + + align:start position:0% +we could also solve the differential + + + align:start position:0% +we could also solve the differential +equation exactly + + align:start position:0% +equation exactly + + + align:start position:0% +equation exactly +and demonstrate that the approximation + + align:start position:0% +and demonstrate that the approximation + + + align:start position:0% +and demonstrate that the approximation +was acceptable + + align:start position:0% +was acceptable + + + align:start position:0% +was acceptable +near the point of approximation t equals + + align:start position:0% +near the point of approximation t equals + + + align:start position:0% +near the point of approximation t equals +zero + + align:start position:0% +zero + + + align:start position:0% +zero +but not so for larger time intervals + + align:start position:0% +but not so for larger time intervals + + + align:start position:0% +but not so for larger time intervals +notice that we used this simple example + + align:start position:0% +notice that we used this simple example + + + align:start position:0% +notice that we used this simple example +to illustrate linear approximation + + align:start position:0% +to illustrate linear approximation + + + align:start position:0% +to illustrate linear approximation +because we could also solve it exactly + + align:start position:0% +because we could also solve it exactly + + + align:start position:0% +because we could also solve it exactly +and use the exact solution to determine + + align:start position:0% +and use the exact solution to determine + + + align:start position:0% +and use the exact solution to determine +the error + + align:start position:0% +the error + + + align:start position:0% +the error +this is somewhat misleading since we + + align:start position:0% +this is somewhat misleading since we + + + align:start position:0% +this is somewhat misleading since we +often want to use linear approximation + + align:start position:0% +often want to use linear approximation + + + align:start position:0% +often want to use linear approximation +precisely when the differential equation + + align:start position:0% +precisely when the differential equation + + + align:start position:0% +precisely when the differential equation +that describes our physical situation + + align:start position:0% +that describes our physical situation + + + align:start position:0% +that describes our physical situation +does not have an analytic solution + + align:start position:0% +does not have an analytic solution + + + align:start position:0% +does not have an analytic solution +so you may wonder is there any way to + + align:start position:0% +so you may wonder is there any way to + + + align:start position:0% +so you may wonder is there any way to +estimate the error in a linear + + align:start position:0% +estimate the error in a linear + + + align:start position:0% +estimate the error in a linear +approximation without knowing the exact + + align:start position:0% +approximation without knowing the exact + + + align:start position:0% +approximation without knowing the exact +solution + + align:start position:0% +solution + + + align:start position:0% +solution +the answer is yes however it involves + + align:start position:0% +the answer is yes however it involves + + + align:start position:0% +the answer is yes however it involves +taylor's remainder theorem + + align:start position:0% +taylor's remainder theorem + + + align:start position:0% +taylor's remainder theorem +which finds an acceptable range in terms + + align:start position:0% +which finds an acceptable range in terms + + + align:start position:0% +which finds an acceptable range in terms +of higher order derivatives + + align:start position:0% +of higher order derivatives + + + align:start position:0% +of higher order derivatives +and is beyond the scope of this video + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/p_10lgn2BiI.txt b/p_10lgn2BiI.txt new file mode 100644 index 0000000000000000000000000000000000000000..307ce3a2fbb115dd77699134cdbcd073106ce776 --- /dev/null +++ b/p_10lgn2BiI.txt @@ -0,0 +1,11699 @@ +align:start position:0% + +so in the lectures are going to record + + align:start position:0% +so in the lectures are going to record + + + align:start position:0% +so in the lectures are going to record +today we're going to conclude cosmology + + align:start position:0% +today we're going to conclude cosmology + + + align:start position:0% +today we're going to conclude cosmology +and then we're going to begin talking + + align:start position:0% +and then we're going to begin talking + + + align:start position:0% +and then we're going to begin talking +about another system in which we solve + + align:start position:0% +about another system in which we solve + + + align:start position:0% +about another system in which we solve +the Einstein field equations using a + + align:start position:0% +the Einstein field equations using a + + + align:start position:0% +the Einstein field equations using a +symmetry so this is one where we will + + align:start position:0% +symmetry so this is one where we will + + + align:start position:0% +symmetry so this is one where we will +again consider systems that are + + align:start position:0% +again consider systems that are + + + align:start position:0% +again consider systems that are +spherically symmetric but we're gonna + + align:start position:0% +spherically symmetric but we're gonna + + + align:start position:0% +spherically symmetric but we're gonna +consider them to be compact ok in other + + align:start position:0% +consider them to be compact ok in other + + + align:start position:0% +consider them to be compact ok in other +words things that are sort of rather + + align:start position:0% +words things that are sort of rather + + + align:start position:0% +words things that are sort of rather +than filling the whole universe the + + align:start position:0% +than filling the whole universe the + + + align:start position:0% +than filling the whole universe the +space-time that arises from a source + + align:start position:0% +space-time that arises from a source + + + align:start position:0% +space-time that arises from a source +that's localized in some particular + + align:start position:0% +that's localized in some particular + + + align:start position:0% +that's localized in some particular +region in space so let me just do a + + align:start position:0% +region in space so let me just do a + + + align:start position:0% +region in space so let me just do a +quick recap of what we did in the + + align:start position:0% +quick recap of what we did in the + + + align:start position:0% +quick recap of what we did in the +previous lectures previous lecture that + + align:start position:0% +previous lectures previous lecture that + + + align:start position:0% +previous lectures previous lecture that +I recorded so by arguing solely from the + + align:start position:0% +I recorded so by arguing solely from the + + + align:start position:0% +I recorded so by arguing solely from the +basis of how to make a space-time that + + align:start position:0% +basis of how to make a space-time that + + + align:start position:0% +basis of how to make a space-time that +is as symmetric as possible in space but + + align:start position:0% +is as symmetric as possible in space but + + + align:start position:0% +is as symmetric as possible in space but +has a time asymmetry so the past and the + + align:start position:0% +has a time asymmetry so the past and the + + + align:start position:0% +has a time asymmetry so the past and the +future looked different we came up with + + align:start position:0% +future looked different we came up with + + + align:start position:0% +future looked different we came up with +the robertson-walker metric okay which i + + align:start position:0% +the robertson-walker metric okay which i + + + align:start position:0% +the robertson-walker metric okay which i +will call the r:w metric which has the + + align:start position:0% +will call the r:w metric which has the + + + align:start position:0% +will call the r:w metric which has the +form i've written there on the top line + + align:start position:0% +form i've written there on the top line + + + align:start position:0% +form i've written there on the top line +there were actually several forms for + + align:start position:0% +there were actually several forms for + + + align:start position:0% +there were actually several forms for +this I've actually written down two + + align:start position:0% +this I've actually written down two + + + align:start position:0% +this I've actually written down two +variants of it on the board here key + + align:start position:0% +variants of it on the board here key + + + align:start position:0% +variants of it on the board here key +things which I want to highlight is that + + align:start position:0% +things which I want to highlight is that + + + align:start position:0% +things which I want to highlight is that +there is in the way I've written it on + + align:start position:0% +there is in the way I've written it on + + + align:start position:0% +there is in the way I've written it on +the first line there's a hidden scale + + align:start position:0% +the first line there's a hidden scale + + + align:start position:0% +the first line there's a hidden scale +and there are zero which you can think + + align:start position:0% +and there are zero which you can think + + + align:start position:0% +and there are zero which you can think +of as essentially setting an overall + + align:start position:0% +of as essentially setting an overall + + + align:start position:0% +of as essentially setting an overall +length scale to everything that could be + + align:start position:0% +length scale to everything that could be + + + align:start position:0% +length scale to everything that could be +measured there is a parameter either K + + align:start position:0% +measured there is a parameter either K + + + align:start position:0% +measured there is a parameter either K +or Kappa K is either minus one zero or + + align:start position:0% +or Kappa K is either minus one zero or + + + align:start position:0% +or Kappa K is either minus one zero or +one Kappa is just K with a factor of + + align:start position:0% +one Kappa is just K with a factor of + + + align:start position:0% +one Kappa is just K with a factor of +that length scale squared thrown in + + align:start position:0% +that length scale squared thrown in + + + align:start position:0% +that length scale squared thrown in +there we define the overall scale factor + + align:start position:0% +there we define the overall scale factor + + + align:start position:0% +there we define the overall scale factor +to be it's just a it's a number and we + + align:start position:0% +to be it's just a it's a number and we + + + align:start position:0% +to be it's just a it's a number and we +define it so that its value is one right + + align:start position:0% +define it so that its value is one right + + + align:start position:0% +define it so that its value is one right +now and then everything is scaled to the + + align:start position:0% +now and then everything is scaled to the + + + align:start position:0% +now and then everything is scaled to the +way distances look at the present time a + + align:start position:0% +way distances look at the present time a + + + align:start position:0% +way distances look at the present time a +second form of that to me which is + + align:start position:0% +second form of that to me which is + + + align:start position:0% +second form of that to me which is +essentially that's a change of variables + + align:start position:0% +essentially that's a change of variables + + + align:start position:0% +essentially that's a change of variables +as you change your you change your + + align:start position:0% +as you change your you change your + + + align:start position:0% +as you change your you change your +radial coordinates to this parameter KY + + align:start position:0% +radial coordinates to this parameter KY + + + align:start position:0% +radial coordinates to this parameter KY +and depending on the value of K what you + + align:start position:0% +and depending on the value of K what you + + + align:start position:0% +and depending on the value of K what you +find then is that the relationship + + align:start position:0% +find then is that the relationship + + + align:start position:0% +find then is that the relationship +between the radius R and the coordinate + + align:start position:0% +between the radius R and the coordinate + + + align:start position:0% +between the radius R and the coordinate +Chi if K + + align:start position:0% +Chi if K + + + align:start position:0% +Chi if K +equals one you have what we call a + + align:start position:0% +equals one you have what we call a + + + align:start position:0% +equals one you have what we call a +closed universe and the radius is equal + + align:start position:0% +closed universe and the radius is equal + + + align:start position:0% +closed universe and the radius is equal +to sign you sign the parameter Chi if + + align:start position:0% +to sign you sign the parameter Chi if + + + align:start position:0% +to sign you sign the parameter Chi if +you have an open universe K equals minus + + align:start position:0% +you have an open universe K equals minus + + + align:start position:0% +you have an open universe K equals minus +1 then the radius is the Cinch of that + + align:start position:0% +1 then the radius is the Cinch of that + + + align:start position:0% +1 then the radius is the Cinch of that +parameter chi and for a flat universe k + + align:start position:0% +parameter chi and for a flat universe k + + + align:start position:0% +parameter chi and for a flat universe k +equals 0 + + align:start position:0% +equals 0 + + + align:start position:0% +equals 0 +they are simply 1 is just the other + + align:start position:0% +they are simply 1 is just the other + + + align:start position:0% +they are simply 1 is just the other +modulo a choice of units with the r 0 + + align:start position:0% +modulo a choice of units with the r 0 + + + align:start position:0% +modulo a choice of units with the r 0 +there all this is just geometry ok so I + + align:start position:0% +there all this is just geometry ok so I + + + align:start position:0% +there all this is just geometry ok so I +when you write this down you're agnostic + + align:start position:0% +when you write this down you're agnostic + + + align:start position:0% +when you write this down you're agnostic +about the form of a and you have no + + align:start position:0% +about the form of a and you have no + + + align:start position:0% +about the form of a and you have no +information about the value of K so to + + align:start position:0% +information about the value of K so to + + + align:start position:0% +information about the value of K so to +get more insight into what's going on + + align:start position:0% +get more insight into what's going on + + + align:start position:0% +get more insight into what's going on +you need a couple this to your source + + align:start position:0% +you need a couple this to your source + + + align:start position:0% +you need a couple this to your source +and so we take these things and using + + align:start position:0% +and so we take these things and using + + + align:start position:0% +and so we take these things and using +the Einstein field equations you equate + + align:start position:0% +the Einstein field equations you equate + + + align:start position:0% +the Einstein field equations you equate +these two a perfect fluid stress energy + + align:start position:0% +these two a perfect fluid stress energy + + + align:start position:0% +these two a perfect fluid stress energy +tensor what you what pops out of that + + align:start position:0% +tensor what you what pops out of that + + + align:start position:0% +tensor what you what pops out of that +are a pair of equations that arise from + + align:start position:0% +are a pair of equations that arise from + + + align:start position:0% +are a pair of equations that arise from +the Einstein field equations I call + + align:start position:0% +the Einstein field equations I call + + + align:start position:0% +the Einstein field equations I call +these f1 and f2 these are the two + + align:start position:0% +these f1 and f2 these are the two + + + align:start position:0% +these f1 and f2 these are the two +Friedmann equations f1 tells me about + + align:start position:0% +Friedmann equations f1 tells me about + + + align:start position:0% +Friedmann equations f1 tells me about +the velocity associate at that expansion + + align:start position:0% +the velocity associate at that expansion + + + align:start position:0% +the velocity associate at that expansion +parameter this is an a dot divided by a + + align:start position:0% +parameter this is an a dot divided by a + + + align:start position:0% +parameter this is an a dot divided by a +squared we call that the Hubble + + align:start position:0% +squared we call that the Hubble + + + align:start position:0% +squared we call that the Hubble +parameter H of a squared and it's + + align:start position:0% +parameter H of a squared and it's + + + align:start position:0% +parameter H of a squared and it's +related to the density of the source of + + align:start position:0% +related to the density of the source of + + + align:start position:0% +related to the density of the source of +your universe as well as this Kappa term + + align:start position:0% +your universe as well as this Kappa term + + + align:start position:0% +your universe as well as this Kappa term +ok and as we saw last time we can get + + align:start position:0% +ok and as we saw last time we can get + + + align:start position:0% +ok and as we saw last time we can get +some information about Kappa from this + + align:start position:0% +some information about Kappa from this + + + align:start position:0% +some information about Kappa from this +equation the second Freedman equation + + align:start position:0% +equation the second Freedman equation + + + align:start position:0% +equation the second Freedman equation +relates the acceleration of this + + align:start position:0% +relates the acceleration of this + + + align:start position:0% +relates the acceleration of this +expansion term a double dot dot by the + + align:start position:0% +expansion term a double dot dot by the + + + align:start position:0% +expansion term a double dot dot by the +way is d by DT a double dot divided by a + + align:start position:0% +way is d by DT a double dot divided by a + + + align:start position:0% +way is d by DT a double dot divided by a +is simply related to a quantity that is + + align:start position:0% +is simply related to a quantity that is + + + align:start position:0% +is simply related to a quantity that is +the density plus 3 times the pressure of + + align:start position:0% +the density plus 3 times the pressure of + + + align:start position:0% +the density plus 3 times the pressure of +this perfect fluid that makes up our + + align:start position:0% +this perfect fluid that makes up our + + + align:start position:0% +this perfect fluid that makes up our +universe we also find by requiring that + + align:start position:0% +universe we also find by requiring that + + + align:start position:0% +universe we also find by requiring that +local energy conservation be held in + + align:start position:0% +local energy conservation be held in + + + align:start position:0% +local energy conservation be held in +other words that your stress energy + + align:start position:0% +other words that your stress energy + + + align:start position:0% +other words that your stress energy +tensor be divergence free we have a + + align:start position:0% +tensor be divergence free we have a + + + align:start position:0% +tensor be divergence free we have a +constraint that relates the amount of + + align:start position:0% +constraint that relates the amount of + + + align:start position:0% +constraint that relates the amount of +energy the rate of change of energy and + + align:start position:0% +energy the rate of change of energy and + + + align:start position:0% +energy the rate of change of energy and +a fiducial volume to the negative of + + align:start position:0% +a fiducial volume to the negative of + + + align:start position:0% +a fiducial volume to the negative of +pressure times the rate of change of + + align:start position:0% +pressure times the rate of change of + + + align:start position:0% +pressure times the rate of change of +that fiducial volume and this as I + + align:start position:0% +that fiducial volume and this as I + + + align:start position:0% +that fiducial volume and this as I +discussed in the last lecture is + + align:start position:0% +discussed in the last lecture is + + + align:start position:0% +discussed in the last lecture is +essentially nothing more than the first + + align:start position:0% +essentially nothing more than the first + + + align:start position:0% +essentially nothing more than the first +law of thermodynamics + + align:start position:0% +law of thermodynamics + + + align:start position:0% +law of thermodynamics +sort of written up in fancy language + + align:start position:0% +sort of written up in fancy language + + + align:start position:0% +sort of written up in fancy language +appropriate to a cosmological space-time + + align:start position:0% +appropriate to a cosmological space-time + + + align:start position:0% +appropriate to a cosmological space-time +as we move forward we find it useful to + + align:start position:0% +as we move forward we find it useful to + + + align:start position:0% +as we move forward we find it useful to +make a couple of definitions so if you + + align:start position:0% +make a couple of definitions so if you + + + align:start position:0% +make a couple of definitions so if you +divide the Hubble parameter squared by + + align:start position:0% +divide the Hubble parameter squared by + + + align:start position:0% +divide the Hubble parameter squared by +Newton's gravitational constant that's + + align:start position:0% +Newton's gravitational constant that's + + + align:start position:0% +Newton's gravitational constant that's +got the dimensions of density and so + + align:start position:0% +got the dimensions of density and so + + + align:start position:0% +got the dimensions of density and so +we're gonna define a critical density to + + align:start position:0% +we're gonna define a critical density to + + + align:start position:0% +we're gonna define a critical density to +be three H squared over 8 pi J and we're + + align:start position:0% +be three H squared over 8 pi J and we're + + + align:start position:0% +be three H squared over 8 pi J and we're +going to define sort of density + + align:start position:0% +going to define sort of density + + + align:start position:0% +going to define sort of density +parameters Omega as the actual physical + + align:start position:0% +parameters Omega as the actual physical + + + align:start position:0% +parameters Omega as the actual physical +densities normalized to that critical + + align:start position:0% +densities normalized to that critical + + + align:start position:0% +densities normalized to that critical +density and when you do this you find + + align:start position:0% +density and when you do this you find + + + align:start position:0% +density and when you do this you find +that the critical assuming you know the + + align:start position:0% +that the critical assuming you know the + + + align:start position:0% +that the critical assuming you know the +first Fremont equation can be written as + + align:start position:0% +first Fremont equation can be written as + + + align:start position:0% +first Fremont equation can be written as +Omega plus a typo Omega plus Omega + + align:start position:0% +Omega plus a typo Omega plus Omega + + + align:start position:0% +Omega plus a typo Omega plus Omega +curvature equals one where Omega + + align:start position:0% +curvature equals one where Omega + + + align:start position:0% +curvature equals one where Omega +curvature pardon the typo here Omega + + align:start position:0% +curvature pardon the typo here Omega + + + align:start position:0% +curvature pardon the typo here Omega +curvature is not actually related to a + + align:start position:0% +curvature is not actually related to a + + + align:start position:0% +curvature is not actually related to a +density but it sort of plays 1 in this + + align:start position:0% +density but it sort of plays 1 in this + + + align:start position:0% +density but it sort of plays 1 in this +equation it is just a that has the + + align:start position:0% +equation it is just a that has the + + + align:start position:0% +equation it is just a that has the +proper dimensions to do what it's + + align:start position:0% +proper dimensions to do what it's + + + align:start position:0% +proper dimensions to do what it's +necessary to fit this equation and it's + + align:start position:0% +necessary to fit this equation and it's + + + align:start position:0% +necessary to fit this equation and it's +it only depends on what the curvature + + align:start position:0% +it only depends on what the curvature + + + align:start position:0% +it only depends on what the curvature +parameter is so remember that this Kappa + + align:start position:0% +parameter is so remember that this Kappa + + + align:start position:0% +parameter is so remember that this Kappa +is essentially minus 1 0 or 1 modulo a + + align:start position:0% +is essentially minus 1 0 or 1 modulo a + + + align:start position:0% +is essentially minus 1 0 or 1 modulo a +factor of my overall scale so this is + + align:start position:0% +factor of my overall scale so this is + + + align:start position:0% +factor of my overall scale so this is +either a positive number 0 or a negative + + align:start position:0% +either a positive number 0 or a negative + + + align:start position:0% +either a positive number 0 or a negative +number all right so let's carry things + + align:start position:0% +number all right so let's carry things + + + align:start position:0% +number all right so let's carry things +forward from here mute my computer so + + align:start position:0% +forward from here mute my computer so + + + align:start position:0% +forward from here mute my computer so +I'm not distracted by things coming in + + align:start position:0% + + + + align:start position:0% + +we now have everything we need using + + align:start position:0% +we now have everything we need using + + + align:start position:0% +we now have everything we need using +this framework to build a universe so + + align:start position:0% +this framework to build a universe so + + + align:start position:0% +this framework to build a universe so +let's write down the recipe to build a + + align:start position:0% +let's write down the recipe to build a + + + align:start position:0% +let's write down the recipe to build a +universe or I should say to build a + + align:start position:0% +universe or I should say to build a + + + align:start position:0% +universe or I should say to build a +model of the universe + + align:start position:0% + + + + align:start position:0% + +so first thing you do is pick your + + align:start position:0% +so first thing you do is pick your + + + align:start position:0% +so first thing you do is pick your +spatial curvature so pick the parameter + + align:start position:0% +spatial curvature so pick the parameter + + + align:start position:0% +spatial curvature so pick the parameter +K to the -1 0 or 1 pick a mixture of + + align:start position:0% +K to the -1 0 or 1 pick a mixture of + + + align:start position:0% +K to the -1 0 or 1 pick a mixture of +species that contributes to the energy + + align:start position:0% +species that contributes to the energy + + + align:start position:0% +species that contributes to the energy +density budget of your model universe so + + align:start position:0% +density budget of your model universe so + + + align:start position:0% +density budget of your model universe so +what you would say is that the total + + align:start position:0% +what you would say is that the total + + + align:start position:0% +what you would say is that the total +density of things in your universe it's + + align:start position:0% +density of things in your universe it's + + + align:start position:0% +density of things in your universe it's +a sum over whatever mixture of stuff is + + align:start position:0% +a sum over whatever mixture of stuff is + + + align:start position:0% +a sum over whatever mixture of stuff is +in your universe you will find it + + align:start position:0% +in your universe you will find it + + + align:start position:0% +in your universe you will find it +helpful to specify an equation of state + + align:start position:0% +helpful to specify an equation of state + + + align:start position:0% +helpful to specify an equation of state +for each species cosmologists typically + + align:start position:0% +for each species cosmologists typically + + + align:start position:0% +for each species cosmologists typically +choose an equation of state that has the + + align:start position:0% +choose an equation of state that has the + + + align:start position:0% +choose an equation of state that has the +following form okay so you require your + + align:start position:0% +following form okay so you require your + + + align:start position:0% +following form okay so you require your +species if you follow this model that + + align:start position:0% +species if you follow this model that + + + align:start position:0% +species if you follow this model that +most cosmologists use each species will + + align:start position:0% +most cosmologists use each species will + + + align:start position:0% +most cosmologists use each species will +have a pressure that is linear in the + + align:start position:0% +have a pressure that is linear in the + + + align:start position:0% +have a pressure that is linear in the +density + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +if you do choose that form then when you + + align:start position:0% +if you do choose that form then when you + + + align:start position:0% +if you do choose that form then when you +enforce local conservation of energy + + align:start position:0% +enforce local conservation of energy + + + align:start position:0% +enforce local conservation of energy +what you will then find is that for + + align:start position:0% +what you will then find is that for + + + align:start position:0% +what you will then find is that for +every one of your species + + align:start position:0% + + + + align:start position:0% + +there is a simple relationship there's a + + align:start position:0% +there is a simple relationship there's a + + + align:start position:0% +there is a simple relationship there's a +simple differential equation that + + align:start position:0% +simple differential equation that + + + align:start position:0% +simple differential equation that +governs how that species evolves as the + + align:start position:0% +governs how that species evolves as the + + + align:start position:0% +governs how that species evolves as the +scale factor changes this can be + + align:start position:0% +scale factor changes this can be + + + align:start position:0% +scale factor changes this can be +immediately integrated up to find that + + align:start position:0% +immediately integrated up to find that + + + align:start position:0% +immediately integrated up to find that +the amount of at some particular moment + + align:start position:0% +the amount of at some particular moment + + + align:start position:0% +the amount of at some particular moment +the density of species I depends on how + + align:start position:0% +the density of species I depends on how + + + align:start position:0% +the density of species I depends on how +it looks and so with zero again denotes + + align:start position:0% +it looks and so with zero again denotes + + + align:start position:0% +it looks and so with zero again denotes +now it is simply proportional to some + + align:start position:0% +now it is simply proportional to some + + + align:start position:0% +now it is simply proportional to some +power of the scale factor where the + + align:start position:0% +power of the scale factor where the + + + align:start position:0% +power of the scale factor where the +power that enters here give me simply + + align:start position:0% +power that enters here give me simply + + + align:start position:0% +power that enters here give me simply +calculated given that equation of state + + align:start position:0% +calculated given that equation of state + + + align:start position:0% +calculated given that equation of state +parameter once you have these things + + align:start position:0% +parameter once you have these things + + + align:start position:0% +parameter once you have these things +together you're ready to roll okay you + + align:start position:0% +together you're ready to roll okay you + + + align:start position:0% +together you're ready to roll okay you +got your frémont equations you've got + + align:start position:0% +got your frémont equations you've got + + + align:start position:0% +got your frémont equations you've got +all the constraints and information you + + align:start position:0% +all the constraints and information you + + + align:start position:0% +all the constraints and information you +need to dig into these equations sit + + align:start position:0% +need to dig into these equations sit + + + align:start position:0% +need to dig into these equations sit +down make your models have a party now + + align:start position:0% +down make your models have a party now + + + align:start position:0% +down make your models have a party now +what we really want to do okay we are + + align:start position:0% +what we really want to do okay we are + + + align:start position:0% +what we really want to do okay we are +physicists and our goal in doing these + + align:start position:0% +physicists and our goal in doing these + + + align:start position:0% +physicists and our goal in doing these +models is to come up with some kind of a + + align:start position:0% +models is to come up with some kind of a + + + align:start position:0% +models is to come up with some kind of a +description of the universe and compare + + align:start position:0% +description of the universe and compare + + + align:start position:0% +description of the universe and compare +it with our data so that we can see what + + align:start position:0% +it with our data so that we can see what + + + align:start position:0% +it with our data so that we can see what +is the nature of the universe that we + + align:start position:0% +is the nature of the universe that we + + + align:start position:0% +is the nature of the universe that we +actually live in okay so what is of + + align:start position:0% +actually live in okay so what is of + + + align:start position:0% +actually live in okay so what is of +interest to us is how does varying all + + align:start position:0% +interest to us is how does varying all + + + align:start position:0% +interest to us is how does varying all +these different terms + + align:start position:0% + + + + align:start position:0% + +change what we're going to talk about + + align:start position:0% +change what we're going to talk about + + + align:start position:0% +change what we're going to talk about +various observables but really if you + + align:start position:0% +various observables but really if you + + + align:start position:0% +various observables but really if you +think about this model how does it + + align:start position:0% +think about this model how does it + + + align:start position:0% +think about this model how does it +change the evolution of the scale factor + + align:start position:0% + + + + align:start position:0% + +everything is bound up in that that is + + align:start position:0% +everything is bound up in that that is + + + align:start position:0% +everything is bound up in that that is +the key thing okay so if I can make a + + align:start position:0% +the key thing okay so if I can make a + + + align:start position:0% +the key thing okay so if I can make a +mathematical model that describes a + + align:start position:0% +mathematical model that describes a + + + align:start position:0% +mathematical model that describes a +universe with all these various + + align:start position:0% +universe with all these various + + + align:start position:0% +universe with all these various +different kinds of ingredients I can sit + + align:start position:0% +different kinds of ingredients I can sit + + + align:start position:0% +different kinds of ingredients I can sit +down and make if I make a really + + align:start position:0% +down and make if I make a really + + + align:start position:0% +down and make if I make a really +complicated thing I probably can't do + + align:start position:0% +complicated thing I probably can't do + + + align:start position:0% +complicated thing I probably can't do +this analytically so that's fine I will + + align:start position:0% +this analytically so that's fine I will + + + align:start position:0% +this analytically so that's fine I will +make a differential equation integrator + + align:start position:0% +make a differential equation integrator + + + align:start position:0% +make a differential equation integrator +that solves all these couple + + align:start position:0% +that solves all these couple + + + align:start position:0% +that solves all these couple +differential equations and I will then + + align:start position:0% +differential equations and I will then + + + align:start position:0% +differential equations and I will then +make predictions for how a of T evolves + + align:start position:0% +make predictions for how a of T evolves + + + align:start position:0% +make predictions for how a of T evolves +depending upon what the different + + align:start position:0% +depending upon what the different + + + align:start position:0% +depending upon what the different +mixtures of species are what the Kircher + + align:start position:0% +mixtures of species are what the Kircher + + + align:start position:0% +mixtures of species are what the Kircher +term is equal to all those together and + + align:start position:0% +term is equal to all those together and + + + align:start position:0% +term is equal to all those together and +make my model but I goal as a physicist + + align:start position:0% +make my model but I goal as a physicist + + + align:start position:0% +make my model but I goal as a physicist +is then to compare this two data and so + + align:start position:0% +is then to compare this two data and so + + + align:start position:0% +is then to compare this two data and so +what I need to do is to come up with + + align:start position:0% +what I need to do is to come up with + + + align:start position:0% +what I need to do is to come up with +some kind of a way this will then be + + align:start position:0% +some kind of a way this will then be + + + align:start position:0% +some kind of a way this will then be +useful we then need some kind of an + + align:start position:0% +useful we then need some kind of an + + + align:start position:0% +useful we then need some kind of an +observational surrogate + + align:start position:0% + + + + align:start position:0% + +for a of t okay what I would like to do + + align:start position:0% +for a of t okay what I would like to do + + + align:start position:0% +for a of t okay what I would like to do +is say great model a predicts the + + align:start position:0% +is say great model a predicts the + + + align:start position:0% +is say great model a predicts the +following evolution of the scale factor + + align:start position:0% +following evolution of the scale factor + + + align:start position:0% +following evolution of the scale factor +model B predicts this machine for the + + align:start position:0% +model B predicts this machine for the + + + align:start position:0% +model B predicts this machine for the +scale factor can I look at the universe + + align:start position:0% +scale factor can I look at the universe + + + align:start position:0% +scale factor can I look at the universe +and deduce whether we are closer to + + align:start position:0% +and deduce whether we are closer to + + + align:start position:0% +and deduce whether we are closer to +model a or closer to model B and in + + align:start position:0% +model a or closer to model B and in + + + align:start position:0% +model a or closer to model B and in +order to do that I need to know how do I + + align:start position:0% +order to do that I need to know how do I + + + align:start position:0% +order to do that I need to know how do I +measure a of T and as we're going to see + + align:start position:0% +measure a of T and as we're going to see + + + align:start position:0% +measure a of T and as we're going to see +this really boils down to two things I + + align:start position:0% +this really boils down to two things I + + + align:start position:0% +this really boils down to two things I +need to be able to deduce if I look at + + align:start position:0% +need to be able to deduce if I look at + + + align:start position:0% +need to be able to deduce if I look at +some event in the universe if I look at + + align:start position:0% +some event in the universe if I look at + + + align:start position:0% +some event in the universe if I look at +something I want to know what scale + + align:start position:0% +something I want to know what scale + + + align:start position:0% +something I want to know what scale +factor to associate with that I need to + + align:start position:0% +factor to associate with that I need to + + + align:start position:0% +factor to associate with that I need to +measure a and I need to know what T to + + align:start position:0% +measure a and I need to know what T to + + + align:start position:0% +measure a and I need to know what T to +label that a with so you know this is + + align:start position:0% +label that a with so you know this is + + + align:start position:0% +label that a with so you know this is +kind of sounds like I'm you know reading + + align:start position:0% +kind of sounds like I'm you know reading + + + align:start position:0% +kind of sounds like I'm you know reading +from the the Journal of duh but if I + + align:start position:0% +from the the Journal of duh but if I + + + align:start position:0% +from the the Journal of duh but if I +want to do this what it basically boils + + align:start position:0% +want to do this what it basically boils + + + align:start position:0% +want to do this what it basically boils +down to is I need to know how to + + align:start position:0% +down to is I need to know how to + + + align:start position:0% +down to is I need to know how to +associate an A with things that I + + align:start position:0% +associate an A with things that I + + + align:start position:0% +associate an A with things that I +measure and how to associate the T with + + align:start position:0% +measure and how to associate the T with + + + align:start position:0% +measure and how to associate the T with +the things that I measure that's what + + align:start position:0% +the things that I measure that's what + + + align:start position:0% +the things that I measure that's what +we're going to talk about today what are + + align:start position:0% +we're going to talk about today what are + + + align:start position:0% +we're going to talk about today what are +the actual observational surrogates the + + align:start position:0% +the actual observational surrogates the + + + align:start position:0% +the actual observational surrogates the +ways in which we can go out point + + align:start position:0% +ways in which we can go out point + + + align:start position:0% +ways in which we can go out point +telescopes and other instruments at + + align:start position:0% +telescopes and other instruments at + + + align:start position:0% +telescopes and other instruments at +things in the sky and deduce what a of T + + align:start position:0% +things in the sky and deduce what a of T + + + align:start position:0% +things in the sky and deduce what a of T +is for the kind of events the kind of + + align:start position:0% +is for the kind of events the kind of + + + align:start position:0% +is for the kind of events the kind of +things that we are going to measure + + align:start position:0% + + + + align:start position:0% + +let's talk about how I can measure the + + align:start position:0% +let's talk about how I can measure the + + + align:start position:0% +let's talk about how I can measure the +scale factor first + + align:start position:0% +scale factor first + + + align:start position:0% +scale factor first +okay so let's ignore the fact that the T + + align:start position:0% +okay so let's ignore the fact that the T + + + align:start position:0% +okay so let's ignore the fact that the T +in here how can I measure a we saw a + + align:start position:0% +in here how can I measure a we saw a + + + align:start position:0% +in here how can I measure a we saw a +hint of this in the previous lecture + + align:start position:0% +hint of this in the previous lecture + + + align:start position:0% +hint of this in the previous lecture +that I recorded so recall + + align:start position:0% +that I recorded so recall + + + align:start position:0% +that I recorded so recall +pardon me I've got a bit of extra junk + + align:start position:0% +pardon me I've got a bit of extra junk + + + align:start position:0% +pardon me I've got a bit of extra junk +here in my notes + + align:start position:0% +here in my notes + + + align:start position:0% +here in my notes +recall that in my previous lecture we + + align:start position:0% +recall that in my previous lecture we + + + align:start position:0% +recall that in my previous lecture we +looked at the way different kinds of + + align:start position:0% +looked at the way different kinds of + + + align:start position:0% +looked at the way different kinds of +densities behave but that got the result + + align:start position:0% +densities behave but that got the result + + + align:start position:0% +densities behave but that got the result +right here for matter which had a an + + align:start position:0% +right here for matter which had a an + + + align:start position:0% +right here for matter which had a an +equation state parameter of 0 what we + + align:start position:0% +equation state parameter of 0 what we + + + align:start position:0% +equation state parameter of 0 what we +found was that the density that the + + align:start position:0% +found was that the density that the + + + align:start position:0% +found was that the density that the +density associated with that matter it + + align:start position:0% +density associated with that matter it + + + align:start position:0% +density associated with that matter it +just fell as the scale factor to the + + align:start position:0% +just fell as the scale factor to the + + + align:start position:0% +just fell as the scale factor to the +inverse third power that's essentially + + align:start position:0% +inverse third power that's essentially + + + align:start position:0% +inverse third power that's essentially +saying that the number of particles of + + align:start position:0% +saying that the number of particles of + + + align:start position:0% +saying that the number of particles of +stuff is + + align:start position:0% +stuff is + + + align:start position:0% +stuff is +constant and so as the universe expands + + align:start position:0% +constant and so as the universe expands + + + align:start position:0% +constant and so as the universe expands +it just goes with the volume of the + + align:start position:0% +it just goes with the volume of the + + + align:start position:0% +it just goes with the volume of the +universe if it was radiation we found it + + align:start position:0% +universe if it was radiation we found it + + + align:start position:0% +universe if it was radiation we found it +went as a scale factor to the inverse + + align:start position:0% +went as a scale factor to the inverse + + + align:start position:0% +went as a scale factor to the inverse +force power and that's consistent with + + align:start position:0% +force power and that's consistent with + + + align:start position:0% +force power and that's consistent with +sort of diluting the density as the + + align:start position:0% +sort of diluting the density as the + + + align:start position:0% +sort of diluting the density as the +volume gets larger provided we also + + align:start position:0% +volume gets larger provided we also + + + align:start position:0% +volume gets larger provided we also +decreased the energy per particle of + + align:start position:0% +decreased the energy per particle of + + + align:start position:0% +decreased the energy per particle of +radiation per photon per graviton per + + align:start position:0% +radiation per photon per graviton per + + + align:start position:0% +radiation per photon per graviton per +whatever on if I require that that the + + align:start position:0% +whatever on if I require that that the + + + align:start position:0% +whatever on if I require that that the +energy per sort of quantum of radiation + + align:start position:0% +energy per sort of quantum of radiation + + + align:start position:0% +energy per sort of quantum of radiation +is redshifted with this thing that that + + align:start position:0% +is redshifted with this thing that that + + + align:start position:0% +is redshifted with this thing that that +explains the density fall-off law that + + align:start position:0% +explains the density fall-off law that + + + align:start position:0% +explains the density fall-off law that +we found for radiation and so that sort + + align:start position:0% +we found for radiation and so that sort + + + align:start position:0% +we found for radiation and so that sort +of suggests that what we're gonna find + + align:start position:0% +of suggests that what we're gonna find + + + align:start position:0% +of suggests that what we're gonna find +is that the scale factor is directly + + align:start position:0% +is that the scale factor is directly + + + align:start position:0% +is that the scale factor is directly +tied to a redshift measure okay um I + + align:start position:0% +tied to a redshift measure okay um I + + + align:start position:0% +tied to a redshift measure okay um I +just realized what this page of notes + + align:start position:0% +just realized what this page of notes + + + align:start position:0% +just realized what this page of notes +was my apologies I'm getting myself + + align:start position:0% +was my apologies I'm getting myself + + + align:start position:0% +was my apologies I'm getting myself +organized here let's make that a little + + align:start position:0% +organized here let's make that a little + + + align:start position:0% +organized here let's make that a little +bit more rigorous now okay so that's + + align:start position:0% +bit more rigorous now okay so that's + + + align:start position:0% +bit more rigorous now okay so that's +argument on the basis of how the density + + align:start position:0% +argument on the basis of how the density + + + align:start position:0% +argument on the basis of how the density +of radiation behaves it's not a bad one + + align:start position:0% +of radiation behaves it's not a bad one + + + align:start position:0% +of radiation behaves it's not a bad one +as a first passed it is quite indicative + + align:start position:0% +as a first passed it is quite indicative + + + align:start position:0% +as a first passed it is quite indicative +but let's come at it from another point + + align:start position:0% +but let's come at it from another point + + + align:start position:0% +but let's come at it from another point +of view and this allows me to introduce + + align:start position:0% + + + + align:start position:0% + +in a brief aside a topic that it's quite + + align:start position:0% +in a brief aside a topic that it's quite + + + align:start position:0% +in a brief aside a topic that it's quite +useful here so we talked about killing + + align:start position:0% +useful here so we talked about killing + + + align:start position:0% +useful here so we talked about killing +vectors a couple of weeks ago let's now + + align:start position:0% +vectors a couple of weeks ago let's now + + + align:start position:0% +vectors a couple of weeks ago let's now +talk about a generalization of this + + align:start position:0% +talk about a generalization of this + + + align:start position:0% +talk about a generalization of this +known as killing tensors so we call that + + align:start position:0% +known as killing tensors so we call that + + + align:start position:0% +known as killing tensors so we call that +a killing vector was defined as a + + align:start position:0% +a killing vector was defined as a + + + align:start position:0% +a killing vector was defined as a +particular vector in my space-time + + align:start position:0% +particular vector in my space-time + + + align:start position:0% +particular vector in my space-time +manifold such that if I Lee transports + + align:start position:0% +manifold such that if I Lee transports + + + align:start position:0% +manifold such that if I Lee transports +the metric along that killing vector I + + align:start position:0% +the metric along that killing vector I + + + align:start position:0% +the metric along that killing vector I +get zero this then leads to the + + align:start position:0% +get zero this then leads to the + + + align:start position:0% +get zero this then leads to the +statements that if I put together the + + align:start position:0% +statements that if I put together the + + + align:start position:0% +statements that if I put together the +symmetrized covariant gradient of the + + align:start position:0% +symmetrized covariant gradient of the + + + align:start position:0% +symmetrized covariant gradient of the +killing factor I get zero another way to + + align:start position:0% +killing factor I get zero another way to + + + align:start position:0% +killing factor I get zero another way to +write this is to use this notation + + align:start position:0% +write this is to use this notation + + + align:start position:0% +write this is to use this notation +whoops + + align:start position:0% + + + + align:start position:0% + +okay so these are equations that tell us + + align:start position:0% +okay so these are equations that tell us + + + align:start position:0% +okay so these are equations that tell us +about the way that killing vectors + + align:start position:0% +about the way that killing vectors + + + align:start position:0% +about the way that killing vectors +behave a killing tensor is just a + + align:start position:0% +behave a killing tensor is just a + + + align:start position:0% +behave a killing tensor is just a +generalization of this idea to an object + + align:start position:0% +generalization of this idea to an object + + + align:start position:0% +generalization of this idea to an object +that has more than one index on it okay + + align:start position:0% +that has more than one index on it okay + + + align:start position:0% +that has more than one index on it okay +to a more to a higher rank tensor II + + align:start position:0% +to a more to a higher rank tensor II + + + align:start position:0% +to a more to a higher rank tensor II +object so we consider this to be a rank + + align:start position:0% +object so we consider this to be a rank + + + align:start position:0% +object so we consider this to be a rank +one killing tensor a rank n killing + + align:start position:0% +one killing tensor a rank n killing + + + align:start position:0% +one killing tensor a rank n killing +tensor satisfies so let's say K is my + + align:start position:0% +tensor satisfies so let's say K is my + + + align:start position:0% +tensor satisfies so let's say K is my +killing tensor so imagine I have n + + align:start position:0% +killing tensor so imagine I have n + + + align:start position:0% +killing tensor so imagine I have n +indices here if I take the covariant + + align:start position:0% +indices here if I take the covariant + + + align:start position:0% +indices here if I take the covariant +gradient of that killing tensor and I + + align:start position:0% +gradient of that killing tensor and I + + + align:start position:0% +gradient of that killing tensor and I +symmetrize over all n indices that gives + + align:start position:0% +symmetrize over all n indices that gives + + + align:start position:0% +symmetrize over all n indices that gives +me zero this defines a killing tensor + + align:start position:0% +me zero this defines a killing tensor + + + align:start position:0% +me zero this defines a killing tensor +[Applause] + + align:start position:0% + + + + align:start position:0% + +starting with this definition it's not + + align:start position:0% +starting with this definition it's not + + + align:start position:0% +starting with this definition it's not +at all hard to show that if I define a + + align:start position:0% +at all hard to show that if I define a + + + align:start position:0% +at all hard to show that if I define a +parameter K + + align:start position:0% + + + + align:start position:0% + +which is what I get when I contract the + + align:start position:0% +which is what I get when I contract the + + + align:start position:0% +which is what I get when I contract the +killing tensor every one of its indices + + align:start position:0% +killing tensor every one of its indices + + + align:start position:0% +killing tensor every one of its indices +with the four velocity of a Judy's ik + + align:start position:0% + + + + align:start position:0% + +okay so if my you satisfy is the G DS + + align:start position:0% +okay so if my you satisfy is the G DS + + + align:start position:0% +okay so if my you satisfy is the G DS +equation or this could be you know what + + align:start position:0% +equation or this could be you know what + + + align:start position:0% +equation or this could be you know what +this right this has a momentum well what + + align:start position:0% +this right this has a momentum well what + + + align:start position:0% +this right this has a momentum well what +you say is the tangents to a world line + + align:start position:0% +you say is the tangents to a world line + + + align:start position:0% +you say is the tangents to a world line +could be either a velocity or a momentum + + align:start position:0% + + + + align:start position:0% + +so if I define the scalar K by + + align:start position:0% +so if I define the scalar K by + + + align:start position:0% +so if I define the scalar K by +contracting my killing tensor with and + + align:start position:0% +contracting my killing tensor with and + + + align:start position:0% +contracting my killing tensor with and +copies of the tangent of the world Y and + + align:start position:0% +copies of the tangent of the world Y and + + + align:start position:0% +copies of the tangent of the world Y and +that thing satisfies a Judy's equation + + align:start position:0% + + + + align:start position:0% + +then the following is true okay you guys + + align:start position:0% +then the following is true okay you guys + + + align:start position:0% +then the following is true okay you guys +did this on a homework exercise for when + + align:start position:0% +did this on a homework exercise for when + + + align:start position:0% +did this on a homework exercise for when +we thought about a space time you did + + align:start position:0% +we thought about a space time you did + + + align:start position:0% +we thought about a space time you did +something that's similar to this I + + align:start position:0% +something that's similar to this I + + + align:start position:0% +something that's similar to this I +should say for a spacetime containing an + + align:start position:0% +should say for a spacetime containing an + + + align:start position:0% +should say for a spacetime containing an +electromagnetic field we talked about + + align:start position:0% +electromagnetic field we talked about + + + align:start position:0% +electromagnetic field we talked about +how this works for the case of a killing + + align:start position:0% +how this works for the case of a killing + + + align:start position:0% +how this works for the case of a killing +vector hopefully you can kind of see the + + align:start position:0% +vector hopefully you can kind of see the + + + align:start position:0% +vector hopefully you can kind of see the +way you would do this calculation at + + align:start position:0% +way you would do this calculation at + + + align:start position:0% +way you would do this calculation at +this point now the reason I'm doing this + + align:start position:0% +this point now the reason I'm doing this + + + align:start position:0% +this point now the reason I'm doing this +aside is that if you have a free bin' + + align:start position:0% +aside is that if you have a free bin' + + + align:start position:0% +aside is that if you have a free bin' +robertson-walker space-time such space + + align:start position:0% +robertson-walker space-time such space + + + align:start position:0% +robertson-walker space-time such space +times actually have a very useful + + align:start position:0% +times actually have a very useful + + + align:start position:0% +times actually have a very useful +killing tensor + + align:start position:0% + + + + align:start position:0% + +so let's define okay two indices mu nu + + align:start position:0% +so let's define okay two indices mu nu + + + align:start position:0% +so let's define okay two indices mu nu +and this is just given by the scale + + align:start position:0% +and this is just given by the scale + + + align:start position:0% +and this is just given by the scale +factor multiplying the metric you move + + align:start position:0% +factor multiplying the metric you move + + + align:start position:0% +factor multiplying the metric you move +you mu you new okay where this you comes + + align:start position:0% +you mu you new okay where this you comes + + + align:start position:0% +you mu you new okay where this you comes +from the for velocity of a co moving + + align:start position:0% +from the for velocity of a co moving + + + align:start position:0% +from the for velocity of a co moving +fluid element so this is the for + + align:start position:0% +fluid element so this is the for + + + align:start position:0% +fluid element so this is the for +velocity that we use to construct the + + align:start position:0% +velocity that we use to construct the + + + align:start position:0% +velocity that we use to construct the +stress energy tensor that is the source + + align:start position:0% +stress energy tensor that is the source + + + align:start position:0% +stress energy tensor that is the source +of our Friedmann equations so here's how + + align:start position:0% +of our Friedmann equations so here's how + + + align:start position:0% +of our Friedmann equations so here's how +we're gonna use this let's look at what + + align:start position:0% +we're gonna use this let's look at what + + + align:start position:0% +we're gonna use this let's look at what +we get for this killing vector CB this + + align:start position:0% +we get for this killing vector CB this + + + align:start position:0% +we get for this killing vector CB this +killing tensor when I consider it along + + align:start position:0% +killing tensor when I consider it along + + + align:start position:0% +killing tensor when I consider it along +a null Judy's ik we're gonna want to + + align:start position:0% +a null Judy's ik we're gonna want to + + + align:start position:0% +a null Judy's ik we're gonna want to +think about null Judy's it's a lot + + align:start position:0% +think about null Judy's it's a lot + + + align:start position:0% +think about null Judy's it's a lot +because the way that we are going to + + align:start position:0% +because the way that we are going to + + + align:start position:0% +because the way that we are going to +probe our universe is with radiation + + align:start position:0% +probe our universe is with radiation + + + align:start position:0% +probe our universe is with radiation +we're going to look at it with these + + align:start position:0% +we're going to look at it with these + + + align:start position:0% +we're going to look at it with these +like telescopes these days people are + + align:start position:0% +like telescopes these days people are + + + align:start position:0% +like telescopes these days people are +starting to probe it with things like + + align:start position:0% +starting to probe it with things like + + + align:start position:0% +starting to probe it with things like +gravitational wave detectors all things + + align:start position:0% +gravitational wave detectors all things + + + align:start position:0% +gravitational wave detectors all things +that involve radiation that moves on + + align:start position:0% +that involve radiation that moves on + + + align:start position:0% +that involve radiation that moves on +null geodesics so let's examine the + + align:start position:0% +null geodesics so let's examine the + + + align:start position:0% +null geodesics so let's examine the +Associated conserved quantity + + align:start position:0% + + + + align:start position:0% + +and is associated with a null Judaism so + + align:start position:0% +and is associated with a null Judaism so + + + align:start position:0% +and is associated with a null Judaism so +let's say V what's making a P actually + + align:start position:0% +let's say V what's making a P actually + + + align:start position:0% +let's say V what's making a P actually +so it's me a null geodesic so we're + + align:start position:0% +so it's me a null geodesic so we're + + + align:start position:0% +so it's me a null geodesic so we're +gonna imagine it's radiation that is + + align:start position:0% +gonna imagine it's radiation that is + + + align:start position:0% +gonna imagine it's radiation that is +following it has a four momentum P mu + + align:start position:0% +following it has a four momentum P mu + + + align:start position:0% +following it has a four momentum P mu +and let's define K k sub ng for my null + + align:start position:0% +and let's define K k sub ng for my null + + + align:start position:0% +and let's define K k sub ng for my null +dude is ik that is going to be came u nu + + align:start position:0% +dude is ik that is going to be came u nu + + + align:start position:0% +dude is ik that is going to be came u nu +P mu P nu let's plug in the definition + + align:start position:0% +P mu P nu let's plug in the definition + + + align:start position:0% +P mu P nu let's plug in the definition +of my killing tensor so this is a + + align:start position:0% +of my killing tensor so this is a + + + align:start position:0% +of my killing tensor so this is a +squared of T G mu nu P mu P nu this is + + align:start position:0% +squared of T G mu nu P mu P nu this is + + + align:start position:0% +squared of T G mu nu P mu P nu this is +zero its analgesic + + align:start position:0% + + + + align:start position:0% + +then I get u mu P nu u nu p nu now + + align:start position:0% +then I get u mu P nu u nu p nu now + + + align:start position:0% +then I get u mu P nu u nu p nu now +remind you of something this + + align:start position:0% + + + + align:start position:0% + +go back to a nice little Easter egg an + + align:start position:0% +go back to a nice little Easter egg an + + + align:start position:0% +go back to a nice little Easter egg an +exercise you guys did a long time ago if + + align:start position:0% +exercise you guys did a long time ago if + + + align:start position:0% +exercise you guys did a long time ago if +I look at the dot product of a for + + align:start position:0% +I look at the dot product of a for + + + align:start position:0% +I look at the dot product of a for +momentum and a for velocity what I get + + align:start position:0% +momentum and a for velocity what I get + + + align:start position:0% +momentum and a for velocity what I get +is the energy associated with that for + + align:start position:0% +is the energy associated with that for + + + align:start position:0% +is the energy associated with that for +momentum as measured by the observer + + align:start position:0% +momentum as measured by the observer + + + align:start position:0% +momentum as measured by the observer +who's for velocity is U so what we get + + align:start position:0% +who's for velocity is U so what we get + + + align:start position:0% +who's for velocity is U so what we get +here is two copies of the energy of that + + align:start position:0% +here is two copies of the energy of that + + + align:start position:0% +here is two copies of the energy of that +null geodesic as measured by the + + align:start position:0% +null geodesic as measured by the + + + align:start position:0% +null geodesic as measured by the +observer who is Co moving so what this + + align:start position:0% +observer who is Co moving so what this + + + align:start position:0% +observer who is Co moving so what this +null geodesic with this quantity + + align:start position:0% +null geodesic with this quantity + + + align:start position:0% +null geodesic with this quantity +associate this null to DS ik is is two + + align:start position:0% +associate this null to DS ik is is two + + + align:start position:0% +associate this null to DS ik is is two +factors two powers of the scale factor + + align:start position:0% +factors two powers of the scale factor + + + align:start position:0% +factors two powers of the scale factor +times the energy that would be measured + + align:start position:0% +times the energy that would be measured + + + align:start position:0% +times the energy that would be measured +by someone who is Co moving with the + + align:start position:0% +by someone who is Co moving with the + + + align:start position:0% +by someone who is Co moving with the +fluid that fills my universe + + align:start position:0% + + + + align:start position:0% + +okay energy of pmu as measured by ummul + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +and remember this is a constant so as + + align:start position:0% +and remember this is a constant so as + + + align:start position:0% +and remember this is a constant so as +this radiation travels across the + + align:start position:0% +this radiation travels across the + + + align:start position:0% +this radiation travels across the +universe you know as its radiation + + align:start position:0% +universe you know as its radiation + + + align:start position:0% +universe you know as its radiation +travels across the universe the product + + align:start position:0% +travels across the universe the product + + + align:start position:0% +travels across the universe the product +of the scale factor and the energy + + align:start position:0% +of the scale factor and the energy + + + align:start position:0% +of the scale factor and the energy +associate that radiation as measured by + + align:start position:0% +associate that radiation as measured by + + + align:start position:0% +associate that radiation as measured by +comoving observers is a constant + + align:start position:0% + + + + align:start position:0% + +so this is telling us that the energy as + + align:start position:0% +so this is telling us that the energy as + + + align:start position:0% +so this is telling us that the energy as +measured by a comoving observer let's + + align:start position:0% +measured by a comoving observer let's + + + align:start position:0% +measured by a comoving observer let's +say it is emitted at some time with a + + align:start position:0% +say it is emitted at some time with a + + + align:start position:0% +say it is emitted at some time with a +scale factor is a when it propagates to + + align:start position:0% +scale factor is a when it propagates to + + + align:start position:0% +scale factor is a when it propagates to +us we define our scale factor as one the + + align:start position:0% +us we define our scale factor as one the + + + align:start position:0% +us we define our scale factor as one the +energy will have fallen down by a factor + + align:start position:0% +energy will have fallen down by a factor + + + align:start position:0% +energy will have fallen down by a factor +of one over a okay so this makes a + + align:start position:0% +of one over a okay so this makes a + + + align:start position:0% +of one over a okay so this makes a +little bit more rigorous that's + + align:start position:0% +little bit more rigorous that's + + + align:start position:0% +little bit more rigorous that's +intuitive argument that we saw from + + align:start position:0% +intuitive argument that we saw from + + + align:start position:0% +intuitive argument that we saw from +considering how the density of radiation + + align:start position:0% +considering how the density of radiation + + + align:start position:0% +considering how the density of radiation +fell off what we see is the energy is + + align:start position:0% +fell off what we see is the energy is + + + align:start position:0% +fell off what we see is the energy is +indeed redshifting with the scale factor + + align:start position:0% +indeed redshifting with the scale factor + + + align:start position:0% +indeed redshifting with the scale factor +so if I use the fact that the energy + + align:start position:0% +so if I use the fact that the energy + + + align:start position:0% +so if I use the fact that the energy +that I observe by me if I'm measuring + + align:start position:0% +that I observe by me if I'm measuring + + + align:start position:0% +that I observe by me if I'm measuring +light light has a frequency of Omega + + align:start position:0% + + + + align:start position:0% + +what I see is the Omega that I observe + + align:start position:0% +what I see is the Omega that I observe + + + align:start position:0% +what I see is the Omega that I observe +at my scale factor which I define to be + + align:start position:0% +at my scale factor which I define to be + + + align:start position:0% +at my scale factor which I define to be +one normalized to that when it was + + align:start position:0% +one normalized to that when it was + + + align:start position:0% +one normalized to that when it was +emitted it looks like the scale factor + + align:start position:0% +emitted it looks like the scale factor + + + align:start position:0% +emitted it looks like the scale factor +when it was emitted divided by a now a + + align:start position:0% +when it was emitted divided by a now a + + + align:start position:0% +when it was emitted divided by a now a +observed I call this one I can flip this + + align:start position:0% +observed I call this one I can flip this + + + align:start position:0% +observed I call this one I can flip this +over another way of saying this is that + + align:start position:0% +over another way of saying this is that + + + align:start position:0% +over another way of saying this is that +if I write it in terms of wavelengths of + + align:start position:0% +if I write it in terms of wavelengths of + + + align:start position:0% +if I write it in terms of wavelengths of +the radiation the wavelength of the + + align:start position:0% +the radiation the wavelength of the + + + align:start position:0% +the radiation the wavelength of the +radiation and when it was emitted versus + + align:start position:0% +radiation and when it was emitted versus + + + align:start position:0% +radiation and when it was emitted versus +the wavelength that we observe it tells + + align:start position:0% +the wavelength that we observe it tells + + + align:start position:0% +the wavelength that we observe it tells +me about the scale factor when the + + align:start position:0% +me about the scale factor when the + + + align:start position:0% +me about the scale factor when the +radiation was emitted + + align:start position:0% + + + + align:start position:0% + +astronomers like to work with redshift + + align:start position:0% +astronomers like to work with redshift + + + align:start position:0% +astronomers like to work with redshift +when they study things like zoom but + + align:start position:0% +when they study things like zoom but + + + align:start position:0% +when they study things like zoom but +they'd like to work with lave length + + align:start position:0% +they'd like to work with lave length + + + align:start position:0% +they'd like to work with lave length +when they study things like the spectra + + align:start position:0% +when they study things like the spectra + + + align:start position:0% +when they study things like the spectra +of distant astronomical objects and they + + align:start position:0% +of distant astronomical objects and they + + + align:start position:0% +of distant astronomical objects and they +use it to define a notion of redshift so + + align:start position:0% +use it to define a notion of redshift so + + + align:start position:0% +use it to define a notion of redshift so +we define the redshift Z to be the + + align:start position:0% +we define the redshift Z to be the + + + align:start position:0% +we define the redshift Z to be the +wavelength that we observe minus the + + align:start position:0% +wavelength that we observe minus the + + + align:start position:0% +wavelength that we observe minus the +wavelength at the radiation net when it + + align:start position:0% +wavelength at the radiation net when it + + + align:start position:0% +wavelength at the radiation net when it +is emitted divided by the wavelength + + align:start position:0% +is emitted divided by the wavelength + + + align:start position:0% +is emitted divided by the wavelength +when it was emitted put all of these + + align:start position:0% +when it was emitted put all of these + + + align:start position:0% +when it was emitted put all of these +definitions together and what this tells + + align:start position:0% +definitions together and what this tells + + + align:start position:0% +definitions together and what this tells +me is that the scale factor at which the + + align:start position:0% +me is that the scale factor at which the + + + align:start position:0% +me is that the scale factor at which the +radiation was emitted + + align:start position:0% +radiation was emitted + + + align:start position:0% +radiation was emitted +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +it's simply related to the redshift that + + align:start position:0% +it's simply related to the redshift that + + + align:start position:0% +it's simply related to the redshift that +we observe so this at last gives us a + + align:start position:0% +we observe so this at last gives us a + + + align:start position:0% +we observe so this at last gives us a +direct and not terribly difficult to use + + align:start position:0% +direct and not terribly difficult to use + + + align:start position:0% +direct and not terribly difficult to use +observational proxy that directly + + align:start position:0% +observational proxy that directly + + + align:start position:0% +observational proxy that directly +encodes the scale factor of our universe + + align:start position:0% +encodes the scale factor of our universe + + + align:start position:0% +encodes the scale factor of our universe +suppose we measure the spectrum of + + align:start position:0% +suppose we measure the spectrum of + + + align:start position:0% +suppose we measure the spectrum of +radiation from some source and we see + + align:start position:0% +radiation from some source and we see + + + align:start position:0% +radiation from some source and we see +the the distinct sort of fingerprint + + align:start position:0% +the the distinct sort of fingerprint + + + align:start position:0% +the the distinct sort of fingerprint +associated with emission from a + + align:start position:0% +associated with emission from a + + + align:start position:0% +associated with emission from a +particular set of atomic transitions + + align:start position:0% + + + + align:start position:0% + +what we generally find is from + + align:start position:0% +what we generally find is from + + + align:start position:0% +what we generally find is from +well-known fingerprints of well + + align:start position:0% +well-known fingerprints of well + + + align:start position:0% +well-known fingerprints of well +characterized transitions + + align:start position:0% + + + + align:start position:0% + +but in general they are stretched by + + align:start position:0% +but in general they are stretched by + + + align:start position:0% +but in general they are stretched by +some factor that we call the redshift Z + + align:start position:0% +some factor that we call the redshift Z + + + align:start position:0% +some factor that we call the redshift Z +actually usually stretch by when you go + + align:start position:0% +actually usually stretch by when you go + + + align:start position:0% +actually usually stretch by when you go +through this you'll find that what you + + align:start position:0% +through this you'll find that what you + + + align:start position:0% +through this you'll find that what you +measure is actually stretched by one + + align:start position:0% +measure is actually stretched by one + + + align:start position:0% +measure is actually stretched by one +plus C you measure that you have + + align:start position:0% +plus C you measure that you have + + + align:start position:0% +plus C you measure that you have +measured the scale factor at which this + + align:start position:0% +measured the scale factor at which this + + + align:start position:0% +measured the scale factor at which this +radiation was measured was emitted so + + align:start position:0% +radiation was measured was emitted so + + + align:start position:0% +radiation was measured was emitted so +this is beautiful this is a way in which + + align:start position:0% +this is beautiful this is a way in which + + + align:start position:0% +this is beautiful this is a way in which +the universe hands us the tool by which + + align:start position:0% +the universe hands us the tool by which + + + align:start position:0% +the universe hands us the tool by which +we can directly characterize the sum of + + align:start position:0% +we can directly characterize the sum of + + + align:start position:0% +we can directly characterize the sum of +the geometry of the universe at which + + align:start position:0% +the geometry of the universe at which + + + align:start position:0% +the geometry of the universe at which +light has been emitted okay this is + + align:start position:0% +light has been emitted okay this is + + + align:start position:0% +light has been emitted okay this is +actually one of the reasons why a lot of + + align:start position:0% +actually one of the reasons why a lot of + + + align:start position:0% +actually one of the reasons why a lot of +people who do cosmology observational + + align:start position:0% +people who do cosmology observational + + + align:start position:0% +people who do cosmology observational +cosmology also happen to be expert + + align:start position:0% +cosmology also happen to be expert + + + align:start position:0% +cosmology also happen to be expert +atomic spectroscopy okay because you + + align:start position:0% +atomic spectroscopy okay because you + + + align:start position:0% +atomic spectroscopy okay because you +want to know to very high precision what + + align:start position:0% +want to know to very high precision what + + + align:start position:0% +want to know to very high precision what +is the characteristics of the hydrogen + + align:start position:0% +is the characteristics of the hydrogen + + + align:start position:0% +is the characteristics of the hydrogen +embalmer lines some of the most + + align:start position:0% +embalmer lines some of the most + + + align:start position:0% +embalmer lines some of the most +important sources for doing these tend + + align:start position:0% +important sources for doing these tend + + + align:start position:0% +important sources for doing these tend +to be galaxies in which there's a lot of + + align:start position:0% +to be galaxies in which there's a lot of + + + align:start position:0% +to be galaxies in which there's a lot of +matter falling on to black holes some of + + align:start position:0% +matter falling on to black holes some of + + + align:start position:0% +matter falling on to black holes some of +the topics we'll be talking about in an + + align:start position:0% +the topics we'll be talking about in an + + + align:start position:0% +the topics we'll be talking about in an +upcoming video as that material falls in + + align:start position:0% +upcoming video as that material falls in + + + align:start position:0% +upcoming video as that material falls in +it gets hot it generates a lot of + + align:start position:0% +it gets hot it generates a lot of + + + align:start position:0% +it gets hot it generates a lot of +radiation and you'll see things like + + align:start position:0% +radiation and you'll see things like + + + align:start position:0% +radiation and you'll see things like +transition lines associated with carbon + + align:start position:0% +transition lines associated with carbon + + + align:start position:0% +transition lines associated with carbon +and iron but often all reddened by a + + align:start position:0% +and iron but often all reddened by a + + + align:start position:0% +and iron but often all reddened by a +factor of several when you sort of go oh + + align:start position:0% +factor of several when you sort of go oh + + + align:start position:0% +factor of several when you sort of go oh +look at that carbon falling on to a + + align:start position:0% +look at that carbon falling on to a + + + align:start position:0% +look at that carbon falling on to a +black hole at redshift 4.8 that is + + align:start position:0% +black hole at redshift 4.8 that is + + + align:start position:0% +black hole at redshift 4.8 that is +happening at a time when the scale + + align:start position:0% +happening at a time when the scale + + + align:start position:0% +happening at a time when the scale +factor the universe was 1 over 4.8 or + + align:start position:0% +factor the universe was 1 over 4.8 or + + + align:start position:0% +factor the universe was 1 over 4.8 or +one number 5.8 forgot to my factor of 1 + + align:start position:0% +one number 5.8 forgot to my factor of 1 + + + align:start position:0% +one number 5.8 forgot to my factor of 1 +plus there + + align:start position:0% + + + + align:start position:0% + +so you measure the redshift and you have + + align:start position:0% +so you measure the redshift and you have + + + align:start position:0% +so you measure the redshift and you have +measured the scale factor but you don't + + align:start position:0% +measured the scale factor but you don't + + + align:start position:0% +measured the scale factor but you don't +know when that light was emitted we need + + align:start position:0% +know when that light was emitted we need + + + align:start position:0% +know when that light was emitted we need +to connect the scale factor that we can + + align:start position:0% +to connect the scale factor that we can + + + align:start position:0% +to connect the scale factor that we can +measure so directly in so beautifully to + + align:start position:0% +measure so directly in so beautifully to + + + align:start position:0% +measure so directly in so beautifully to +the time at which it was emitted okay we + + align:start position:0% +the time at which it was emitted okay we + + + align:start position:0% +the time at which it was emitted okay we +now have a way of determining a but we + + align:start position:0% +now have a way of determining a but we + + + align:start position:0% +now have a way of determining a but we +need a as a function of T okay and in + + align:start position:0% +need a as a function of T okay and in + + + align:start position:0% +need a as a function of T okay and in +truth we do this kind of via a surrogate + + align:start position:0% +truth we do this kind of via a surrogate + + + align:start position:0% +truth we do this kind of via a surrogate +because we are using radiation as our + + align:start position:0% +because we are using radiation as our + + + align:start position:0% +because we are using radiation as our +tool for probing the scale factor we + + align:start position:0% +tool for probing the scale factor we + + + align:start position:0% +tool for probing the scale factor we +really don't measure T directly okay + + align:start position:0% +really don't measure T directly okay + + + align:start position:0% +really don't measure T directly okay +when we look at light and it's coming to + + align:start position:0% +when we look at light and it's coming to + + + align:start position:0% +when we look at light and it's coming to +us it doesn't say I was emitted on March + + align:start position:0% +us it doesn't say I was emitted on March + + + align:start position:0% +us it doesn't say I was emitted on March +27th of the year negative six point + + align:start position:0% +27th of the year negative six point + + + align:start position:0% +27th of the year negative six point +eight billion BC or something like that + + align:start position:0% +eight billion BC or something like that + + + align:start position:0% +eight billion BC or something like that +we do know though that it traveled + + align:start position:0% +we do know though that it traveled + + + align:start position:0% +we do know though that it traveled +towards us at the speed of light on a + + align:start position:0% +towards us at the speed of light on a + + + align:start position:0% +towards us at the speed of light on a +null geodesic and because it's a null + + align:start position:0% +null geodesic and because it's a null + + + align:start position:0% +null geodesic and because it's a null +geodesic there's a very simple simple a + + align:start position:0% +geodesic there's a very simple simple a + + + align:start position:0% +geodesic there's a very simple simple a +little bit of an overstatement but there + + align:start position:0% +little bit of an overstatement but there + + + align:start position:0% +little bit of an overstatement but there +is at least a calculable connection + + align:start position:0% +is at least a calculable connection + + + align:start position:0% +is at least a calculable connection +because it's moving at the speed of + + align:start position:0% +because it's moving at the speed of + + + align:start position:0% +because it's moving at the speed of +light we can simply should stop using + + align:start position:0% +light we can simply should stop using + + + align:start position:0% +light we can simply should stop using +that word + + align:start position:0% +that word + + + align:start position:0% +that word +we can connect time to space and so + + align:start position:0% +we can connect time to space and so + + + align:start position:0% +we can connect time to space and so +rather than directly determining the + + align:start position:0% +rather than directly determining the + + + align:start position:0% +rather than directly determining the +time at which the radiation was emitted + + align:start position:0% +time at which the radiation was emitted + + + align:start position:0% +time at which the radiation was emitted +we want to calculate the distance of the + + align:start position:0% +we want to calculate the distance of the + + + align:start position:0% +we want to calculate the distance of the +source from us that emitted it + + align:start position:0% + + + + align:start position:0% + +so rather than directly building up a of + + align:start position:0% +so rather than directly building up a of + + + align:start position:0% +so rather than directly building up a of +tea we're going to build up an a of D + + align:start position:0% +tea we're going to build up an a of D + + + align:start position:0% +tea we're going to build up an a of D +okay where D is the distance of the + + align:start position:0% +okay where D is the distance of the + + + align:start position:0% +okay where D is the distance of the +source and if you're used to working in + + align:start position:0% +source and if you're used to working in + + + align:start position:0% +source and if you're used to working in +sort of Euclidean geometry so we go ah + + align:start position:0% +sort of Euclidean geometry so we go ah + + + align:start position:0% +sort of Euclidean geometry so we go ah +okay great I know that light travels at + + align:start position:0% +okay great I know that light travels at + + + align:start position:0% +okay great I know that light travels at +the speed of light so all I need to do + + align:start position:0% +the speed of light so all I need to do + + + align:start position:0% +the speed of light so all I need to do +is divide the distance by C and I've got + + align:start position:0% +is divide the distance by C and I've got + + + align:start position:0% +is divide the distance by C and I've got +the time and I build a of T conceptually + + align:start position:0% +the time and I build a of T conceptually + + + align:start position:0% +the time and I build a of T conceptually +that is roughly right and that gives at + + align:start position:0% +that is roughly right and that gives at + + + align:start position:0% +that is roughly right and that gives at +least a cartoon or the idea that's going + + align:start position:0% +least a cartoon or the idea that's going + + + align:start position:0% +least a cartoon or the idea that's going +on here but we have to be a little bit + + align:start position:0% +on here but we have to be a little bit + + + align:start position:0% +on here but we have to be a little bit +careful okay because it turns out when + + align:start position:0% +careful okay because it turns out when + + + align:start position:0% +careful okay because it turns out when +you are making measurements in a curved + + align:start position:0% +you are making measurements in a curved + + + align:start position:0% +you are making measurements in a curved +space-time the notion of distance that + + align:start position:0% +space-time the notion of distance that + + + align:start position:0% +space-time the notion of distance that +you use depends on how you make the + + align:start position:0% +you use depends on how you make the + + + align:start position:0% +you use depends on how you make the +distance measurement so this leads us + + align:start position:0% +distance measurement so this leads us + + + align:start position:0% +distance measurement so this leads us +now to our discussion of distance + + align:start position:0% +now to our discussion of distance + + + align:start position:0% +now to our discussion of distance +measures in cosmological spacetimes + + align:start position:0% + + + + align:start position:0% + +so just to get a little bit of intuition + + align:start position:0% +so just to get a little bit of intuition + + + align:start position:0% +so just to get a little bit of intuition +as to what's needed or look at the kind + + align:start position:0% +as to what's needed or look at the kind + + + align:start position:0% +as to what's needed or look at the kind +of calculation we're going to need to do + + align:start position:0% +of calculation we're going to need to do + + + align:start position:0% +of calculation we're going to need to do +let me describe one distance measure + + align:start position:0% +let me describe one distance measure + + + align:start position:0% +let me describe one distance measure +that is observation it's just about + + align:start position:0% +that is observation it's just about + + + align:start position:0% +that is observation it's just about +useless but it's not a bad thing to at + + align:start position:0% +useless but it's not a bad thing to at + + + align:start position:0% +useless but it's not a bad thing to at +least you know begin to get a get a + + align:start position:0% +least you know begin to get a get a + + + align:start position:0% +least you know begin to get a get a +handle on the way different the way + + align:start position:0% +handle on the way different the way + + + align:start position:0% +handle on the way different the way +different parameters of the space-time + + align:start position:0% +different parameters of the space-time + + + align:start position:0% +different parameters of the space-time +come in and influence what the distance + + align:start position:0% +come in and influence what the distance + + + align:start position:0% +come in and influence what the distance +measure means so let's just think about + + align:start position:0% +measure means so let's just think about + + + align:start position:0% +measure means so let's just think about +the proper distance from us to a source + + align:start position:0% + + + + align:start position:0% + +so let's see let's imagine that let's + + align:start position:0% +so let's see let's imagine that let's + + + align:start position:0% +so let's see let's imagine that let's +just begin by first let's write down my + + align:start position:0% +just begin by first let's write down my + + + align:start position:0% +just begin by first let's write down my +line element and here's the form that + + align:start position:0% +line element and here's the form that + + + align:start position:0% +line element and here's the form that +I'm going to use okay so here's my line + + align:start position:0% +I'm going to use okay so here's my line + + + align:start position:0% +I'm going to use okay so here's my line +element this is my differential + + align:start position:0% +element this is my differential + + + align:start position:0% +element this is my differential +connection between two events spaced + + align:start position:0% +connection between two events spaced + + + align:start position:0% +connection between two events spaced +between one another by DT D KY D theta D + + align:start position:0% +between one another by DT D KY D theta D + + + align:start position:0% +between one another by DT D KY D theta D +Phi all hidden in that angular angular + + align:start position:0% +Phi all hidden in that angular angular + + + align:start position:0% +Phi all hidden in that angular angular +element D Omega so let's imagine that we + + align:start position:0% +element D Omega so let's imagine that we + + + align:start position:0% +element D Omega so let's imagine that we +want to consider two sources that are + + align:start position:0% +want to consider two sources that are + + + align:start position:0% +want to consider two sources that are +separated purely in the radial direction + + align:start position:0% + + + + align:start position:0% + +so my angular displacement machine the + + align:start position:0% +so my angular displacement machine the + + + align:start position:0% +so my angular displacement machine the +two events it's going to be zero so the + + align:start position:0% +two events it's going to be zero so the + + + align:start position:0% +two events it's going to be zero so the +only thing I need to care about is D Chi + + align:start position:0% +only thing I need to care about is D Chi + + + align:start position:0% +only thing I need to care about is D Chi +and let's imagine that I determine the + + align:start position:0% +and let's imagine that I determine the + + + align:start position:0% +and let's imagine that I determine the +distance between these two at some + + align:start position:0% +distance between these two at some + + + align:start position:0% +distance between these two at some +instant okay so then you just get DS + + align:start position:0% +instant okay so then you just get DS + + + align:start position:0% +instant okay so then you just get DS +squared equals a squared r0 squared D KY + + align:start position:0% +squared equals a squared r0 squared D KY + + + align:start position:0% +squared equals a squared r0 squared D KY +squared and you can integrate this up + + align:start position:0% +squared and you can integrate this up + + + align:start position:0% +squared and you can integrate this up +and you get our first distance measure D + + align:start position:0% +and you get our first distance measure D + + + align:start position:0% +and you get our first distance measure D +sub P equals scale factor your overall + + align:start position:0% +sub P equals scale factor your overall + + + align:start position:0% +sub P equals scale factor your overall +distance scale are 0 and Chi so Carol's + + align:start position:0% +distance scale are 0 and Chi so Carol's + + + align:start position:0% +distance scale are 0 and Chi so Carol's +textbook calls this the instantaneous + + align:start position:0% +textbook calls this the instantaneous + + + align:start position:0% +textbook calls this the instantaneous +physical distance + + align:start position:0% + + + + align:start position:0% + +let's think about what this means if you + + align:start position:0% +let's think about what this means if you + + + align:start position:0% +let's think about what this means if you +do this this is basically the distance + + align:start position:0% +do this this is basically the distance + + + align:start position:0% +do this this is basically the distance +you would get if you took a yardstick + + align:start position:0% +you would get if you took a yardstick + + + align:start position:0% +you would get if you took a yardstick +you put one end at yourself you're gonna + + align:start position:0% +you put one end at yourself you're gonna + + + align:start position:0% +you put one end at yourself you're gonna +call yourself Chi equals zero you put + + align:start position:0% +call yourself Chi equals zero you put + + + align:start position:0% +call yourself Chi equals zero you put +the other end of the yardstick at the + + align:start position:0% +the other end of the yardstick at the + + + align:start position:0% +the other end of the yardstick at the +object in your universe at some of some + + align:start position:0% +object in your universe at some of some + + + align:start position:0% +object in your universe at some of some +distance Chi in these coordinates and + + align:start position:0% +distance Chi in these coordinates and + + + align:start position:0% +distance Chi in these coordinates and +that's the distance D sub P is the + + align:start position:0% +that's the distance D sub P is the + + + align:start position:0% +that's the distance D sub P is the +distance that you measure it is done + + align:start position:0% +distance that you measure it is done + + + align:start position:0% +distance that you measure it is done +you're sort of imagining that both of + + align:start position:0% +you're sort of imagining that both of + + + align:start position:0% +you're sort of imagining that both of +the events at the end of this yardstick + + align:start position:0% +the events at the end of this yardstick + + + align:start position:0% +the events at the end of this yardstick +you're sort of ascertaining their + + align:start position:0% +you're sort of ascertaining their + + + align:start position:0% +you're sort of ascertaining their +position at exactly the same instant + + align:start position:0% +position at exactly the same instant + + + align:start position:0% +position at exactly the same instant +hence the term instantaneous and you get + + align:start position:0% +hence the term instantaneous and you get + + + align:start position:0% +hence the term instantaneous and you get +something out of it that encodes some + + align:start position:0% +something out of it that encodes some + + + align:start position:0% +something out of it that encodes some +important aspects of how we think about + + align:start position:0% +important aspects of how we think about + + + align:start position:0% +important aspects of how we think about +distances in cosmology so notice + + align:start position:0% +distances in cosmology so notice + + + align:start position:0% +distances in cosmology so notice +everything scales with the overall + + align:start position:0% +everything scales with the overall + + + align:start position:0% +everything scales with the overall +length scale that we associate it with + + align:start position:0% +length scale that we associate it with + + + align:start position:0% +length scale that we associate it with +our spatial slices with our spatial + + align:start position:0% +our spatial slices with our spatial + + + align:start position:0% +our spatial slices with our spatial +sector of this metric the are zero + + align:start position:0% +sector of this metric the are zero + + + align:start position:0% +sector of this metric the are zero +notice that whatever is going on with + + align:start position:0% +notice that whatever is going on with + + + align:start position:0% +notice that whatever is going on with +your scale factor your a your distance + + align:start position:0% +your scale factor your a your distance + + + align:start position:0% +your scale factor your a your distance +is going to track that as a consequence + + align:start position:0% +is going to track that as a consequence + + + align:start position:0% +is going to track that as a consequence +of this two objects that are sitting in + + align:start position:0% +of this two objects that are sitting in + + + align:start position:0% +of this two objects that are sitting in +what we call the Hubble flow in other + + align:start position:0% +what we call the Hubble flow in other + + + align:start position:0% +what we call the Hubble flow in other +words two objects that are Co moving + + align:start position:0% +words two objects that are Co moving + + + align:start position:0% +words two objects that are Co moving +with the the fluid that makes up the + + align:start position:0% +with the the fluid that makes up the + + + align:start position:0% +with the the fluid that makes up the +source of our universe they have an + + align:start position:0% +source of our universe they have an + + + align:start position:0% +source of our universe they have an +apparent motion with respect to each + + align:start position:0% +apparent motion with respect to each + + + align:start position:0% +apparent motion with respect to each +other + + align:start position:0% + + + + align:start position:0% + +I take the time derivative of this via + + align:start position:0% +I take the time derivative of this via + + + align:start position:0% +I take the time derivative of this via +parent + + align:start position:0% + + + + align:start position:0% + +yes the apparent is just a dot R zero + + align:start position:0% +yes the apparent is just a dot R zero + + + align:start position:0% +yes the apparent is just a dot R zero +Chi which is equal to the Hubble + + align:start position:0% +Chi which is equal to the Hubble + + + align:start position:0% +Chi which is equal to the Hubble +parameter times DP okay recall that the + + align:start position:0% +parameter times DP okay recall that the + + + align:start position:0% +parameter times DP okay recall that the +Hubble parameter it is a dot over a and + + align:start position:0% +Hubble parameter it is a dot over a and + + + align:start position:0% +Hubble parameter it is a dot over a and +if I'm doing this right now that's the + + align:start position:0% +if I'm doing this right now that's the + + + align:start position:0% +if I'm doing this right now that's the +Hubble value of the Hubble parameter now + + align:start position:0% +Hubble value of the Hubble parameter now + + + align:start position:0% +Hubble value of the Hubble parameter now +so this is the Hubble expansion laws a + + align:start position:0% +so this is the Hubble expansion laws a + + + align:start position:0% +so this is the Hubble expansion laws a +very famous Hubble expansion law okay so + + align:start position:0% +very famous Hubble expansion law okay so + + + align:start position:0% +very famous Hubble expansion law okay so +we can see it hidden in this not even + + align:start position:0% +we can see it hidden in this not even + + + align:start position:0% +we can see it hidden in this not even +really hidden that's quite apparent in + + align:start position:0% +really hidden that's quite apparent in + + + align:start position:0% +really hidden that's quite apparent in +this notion of an instantaneous physical + + align:start position:0% +this notion of an instantaneous physical + + + align:start position:0% +this notion of an instantaneous physical +distance let me just finally emphasize + + align:start position:0% +distance let me just finally emphasize + + + align:start position:0% +distance let me just finally emphasize +though that the instance in a'ti that is + + align:start position:0% +though that the instance in a'ti that is + + + align:start position:0% +though that the instance in a'ti that is +part of this objects name instantaneous + + align:start position:0% +part of this objects name instantaneous + + + align:start position:0% +part of this objects name instantaneous +measurements are not done okay so i as i + + align:start position:0% +measurements are not done okay so i as i + + + align:start position:0% +measurements are not done okay so i as i +said i mean this is it sounds like i'm + + align:start position:0% +said i mean this is it sounds like i'm + + + align:start position:0% +said i mean this is it sounds like i'm +being slightly facetious but it's not + + align:start position:0% +being slightly facetious but it's not + + + align:start position:0% +being slightly facetious but it's not +the meaning of this distance measure is + + align:start position:0% +the meaning of this distance measure is + + + align:start position:0% +the meaning of this distance measure is +like I said it's a yardstick where I + + align:start position:0% +like I said it's a yardstick where I + + + align:start position:0% +like I said it's a yardstick where I +have an event at me the other end of my + + align:start position:0% +have an event at me the other end of my + + + align:start position:0% +have an event at me the other end of my +yardstick is at my cosmological event + + align:start position:0% +yardstick is at my cosmological event + + + align:start position:0% +yardstick is at my cosmological event +those are typically separated by + + align:start position:0% +those are typically separated by + + + align:start position:0% +those are typically separated by +millions billions of light years okay + + align:start position:0% +millions billions of light years okay + + + align:start position:0% +millions billions of light years okay +even if you could okay + + align:start position:0% +even if you could okay + + + align:start position:0% +even if you could okay +the facetious bit was imagining this a + + align:start position:0% +the facetious bit was imagining this a + + + align:start position:0% +the facetious bit was imagining this a +yardstick but the non facetious point I + + align:start position:0% +yardstick but the non facetious point I + + + align:start position:0% +yardstick but the non facetious point I +want to make is we do not make + + align:start position:0% +want to make is we do not make + + + align:start position:0% +want to make is we do not make +instantaneous measurements with that + + align:start position:0% +instantaneous measurements with that + + + align:start position:0% +instantaneous measurements with that +okay when I measure an event that is + + align:start position:0% +okay when I measure an event that is + + + align:start position:0% +okay when I measure an event that is +billions of light years away I am of + + align:start position:0% +billions of light years away I am of + + + align:start position:0% +billions of light years away I am of +course measuring it using lights and I'm + + align:start position:0% +course measuring it using lights and I'm + + + align:start position:0% +course measuring it using lights and I'm +seeing light that was emitted billions + + align:start position:0% +seeing light that was emitted billions + + + align:start position:0% +seeing light that was emitted billions +of years ago so we need to think a + + align:start position:0% +of years ago so we need to think a + + + align:start position:0% +of years ago so we need to think a +little bit more carefully about how to + + align:start position:0% +little bit more carefully about how to + + + align:start position:0% +little bit more carefully about how to +define distance in terms of quantities + + align:start position:0% +define distance in terms of quantities + + + align:start position:0% +define distance in terms of quantities +that really correspond to measurements + + align:start position:0% +that really correspond to measurements + + + align:start position:0% +that really correspond to measurements +we can make + + align:start position:0% + + + + align:start position:0% + +and to get a little intuition here are + + align:start position:0% +and to get a little intuition here are + + + align:start position:0% +and to get a little intuition here are +three ways where if you were living in + + align:start position:0% +three ways where if you were living in + + + align:start position:0% +three ways where if you were living in +Euclidean space and you were looking at + + align:start position:0% +Euclidean space and you were looking at + + + align:start position:0% +Euclidean space and you were looking at +light from distant objects here are + + align:start position:0% +light from distant objects here are + + + align:start position:0% +light from distant objects here are +three ways that you could define + + align:start position:0% +three ways that you could define + + + align:start position:0% +three ways that you could define +distance so if space-time were that of + + align:start position:0% +distance so if space-time were that of + + + align:start position:0% +distance so if space-time were that of +special relativity well let's just say + + align:start position:0% +special relativity well let's just say + + + align:start position:0% +special relativity well let's just say +if space were purely Euclidean let's + + align:start position:0% +if space were purely Euclidean let's + + + align:start position:0% +if space were purely Euclidean let's +just leave it like that + + align:start position:0% + + + + align:start position:0% + +here are three notions that we could use + + align:start position:0% +here are three notions that we could use + + + align:start position:0% +here are three notions that we could use +what imagine there was some source of + + align:start position:0% +what imagine there was some source of + + + align:start position:0% +what imagine there was some source of +radiation in the universe that you + + align:start position:0% +radiation in the universe that you + + + align:start position:0% +radiation in the universe that you +understood so well that you knew its + + align:start position:0% +understood so well that you knew its + + + align:start position:0% +understood so well that you knew its +intrinsic luminosity what you could do + + align:start position:0% +intrinsic luminosity what you could do + + + align:start position:0% +intrinsic luminosity what you could do +is compare the intrinsic luminosity of a + + align:start position:0% +is compare the intrinsic luminosity of a + + + align:start position:0% +is compare the intrinsic luminosity of a +source to its apparent brightness + + align:start position:0% + + + + align:start position:0% + +so let's let f be the flux we measure + + align:start position:0% +so let's let f be the flux we measure + + + align:start position:0% +so let's let f be the flux we measure +from this source this will be related to + + align:start position:0% +from this source this will be related to + + + align:start position:0% +from this source this will be related to +L the luminosity which suspend disbelief + + align:start position:0% +L the luminosity which suspend disbelief + + + align:start position:0% +L the luminosity which suspend disbelief +for a moment want to sort of imagine + + align:start position:0% +for a moment want to sort of imagine + + + align:start position:0% +for a moment want to sort of imagine +that we know it for some reason and if + + align:start position:0% +that we know it for some reason and if + + + align:start position:0% +that we know it for some reason and if +we imagine this is an isotropic emitter + + align:start position:0% +we imagine this is an isotropic emitter + + + align:start position:0% +we imagine this is an isotropic emitter +this will be related by a factor of four + + align:start position:0% +this will be related by a factor of four + + + align:start position:0% +this will be related by a factor of four +pi and the distance between us and that + + align:start position:0% +pi and the distance between us and that + + + align:start position:0% +pi and the distance between us and that +source let's call this D sub L this is a + + align:start position:0% +source let's call this D sub L this is a + + + align:start position:0% +source let's call this D sub L this is a +luminosity distance it is a distance it + + align:start position:0% +luminosity distance it is a distance it + + + align:start position:0% +luminosity distance it is a distance it +is a distance that we measure by + + align:start position:0% +is a distance that we measure by + + + align:start position:0% +is a distance that we measure by +inferring the behavior of luminosity of + + align:start position:0% +inferring the behavior of luminosity of + + + align:start position:0% +inferring the behavior of luminosity of +a distant object now it turns out and + + align:start position:0% +a distant object now it turns out and + + + align:start position:0% +a distant object now it turns out and +this is a subject for a different class + + align:start position:0% +this is a subject for a different class + + + align:start position:0% +this is a subject for a different class +but nature actually gives us some + + align:start position:0% +but nature actually gives us some + + + align:start position:0% +but nature actually gives us some +objects whose luminosity is known or at + + align:start position:0% +objects whose luminosity is known or at + + + align:start position:0% +objects whose luminosity is known or at +least can be calibrated in the case of + + align:start position:0% +least can be calibrated in the case of + + + align:start position:0% +least can be calibrated in the case of +much of what is done in cosmology today + + align:start position:0% +much of what is done in cosmology today + + + align:start position:0% +much of what is done in cosmology today +we can take advantage of the behavior of + + align:start position:0% +we can take advantage of the behavior of + + + align:start position:0% +we can take advantage of the behavior of +certain stars whose luminosity is + + align:start position:0% +certain stars whose luminosity is + + + align:start position:0% +certain stars whose luminosity is +strongly correlated to the way that they + + align:start position:0% +strongly correlated to the way that they + + + align:start position:0% +strongly correlated to the way that they +that their these are stars whose + + align:start position:0% +that their these are stars whose + + + align:start position:0% +that their these are stars whose +luminosity is variable and we can use + + align:start position:0% +luminosity is variable and we can use + + + align:start position:0% +luminosity is variable and we can use +the fact that their variability is + + align:start position:0% +the fact that their variability is + + + align:start position:0% +the fact that their variability is +correlated to the luminosity to infer + + align:start position:0% +correlated to the luminosity to infer + + + align:start position:0% +correlated to the luminosity to infer +what their absolute luminosity actually + + align:start position:0% +what their absolute luminosity actually + + + align:start position:0% +what their absolute luminosity actually +is there are other supernova events + + align:start position:0% +is there are other supernova events + + + align:start position:0% +is there are other supernova events +whose luminosity likewise + + align:start position:0% +whose luminosity likewise + + + align:start position:0% +whose luminosity likewise +appears to follow a universal law it's + + align:start position:0% +appears to follow a universal law it's + + + align:start position:0% +appears to follow a universal law it's +related to the fact that the explosions + + align:start position:0% +related to the fact that the explosions + + + align:start position:0% +related to the fact that the explosions +of these objects are the properties of + + align:start position:0% +of these objects are the properties of + + + align:start position:0% +of these objects are the properties of +those explosions are actually set by the + + align:start position:0% +those explosions are actually set by the + + + align:start position:0% +those explosions are actually set by the +micro physics of the stars that set them + + align:start position:0% +micro physics of the stars that set them + + + align:start position:0% +micro physics of the stars that set them +more recently we've been able to exploit + + align:start position:0% +more recently we've been able to exploit + + + align:start position:0% +more recently we've been able to exploit +the fact that gravitational wave sources + + align:start position:0% +the fact that gravitational wave sources + + + align:start position:0% +the fact that gravitational wave sources +have an intrinsic luminosity in + + align:start position:0% +have an intrinsic luminosity in + + + align:start position:0% +have an intrinsic luminosity in +gravitational waves that the EDT + + align:start position:0% +gravitational waves that the EDT + + + align:start position:0% +gravitational waves that the EDT +associate the gravitation waves that + + align:start position:0% +associate the gravitation waves that + + + align:start position:0% +associate the gravitation waves that +they emit which depends on the source + + align:start position:0% +they emit which depends on the source + + + align:start position:0% +they emit which depends on the source +gravitational physics in a very simple + + align:start position:0% +gravitational physics in a very simple + + + align:start position:0% +gravitational physics in a very simple +predictable way that doesn't depend on + + align:start position:0% +predictable way that doesn't depend on + + + align:start position:0% +predictable way that doesn't depend on +very many parameters my she did a little + + align:start position:0% +very many parameters my she did a little + + + align:start position:0% +very many parameters my she did a little +bit of + + align:start position:0% +bit of + + + align:start position:0% +bit of +work on that over the course of my + + align:start position:0% +work on that over the course of my + + + align:start position:0% +work on that over the course of my +career and it's a very exciting + + align:start position:0% +career and it's a very exciting + + + align:start position:0% +career and it's a very exciting +development that we can now use these + + align:start position:0% +development that we can now use these + + + align:start position:0% +development that we can now use these +the way of setting sort of the intrinsic + + align:start position:0% +the way of setting sort of the intrinsic + + + align:start position:0% +the way of setting sort of the intrinsic +luminosity of certain sources at a rate + + align:start position:0% +luminosity of certain sources at a rate + + + align:start position:0% +luminosity of certain sources at a rate +if you can take advantage of these + + align:start position:0% +if you can take advantage of these + + + align:start position:0% +if you can take advantage of these +objects that have a known luminosity and + + align:start position:0% +objects that have a known luminosity and + + + align:start position:0% +objects that have a known luminosity and +you can then measure the flux of + + align:start position:0% +you can then measure the flux of + + + align:start position:0% +you can then measure the flux of +radiation in your detector from these + + align:start position:0% +radiation in your detector from these + + + align:start position:0% +radiation in your detector from these +things you have learned the distance at + + align:start position:0% +things you have learned the distance at + + + align:start position:0% +things you have learned the distance at +least you have learned this particular + + align:start position:0% +least you have learned this particular + + + align:start position:0% +least you have learned this particular +measure of the distance let's measure + + align:start position:0% +measure of the distance let's measure + + + align:start position:0% +measure of the distance let's measure +one + + align:start position:0% + + + + align:start position:0% + +measure to is compare imagining of some + + align:start position:0% +measure to is compare imagining of some + + + align:start position:0% +measure to is compare imagining of some +object in the sky that has a particular + + align:start position:0% +object in the sky that has a particular + + + align:start position:0% +object in the sky that has a particular +intrinsic size associated with it okay + + align:start position:0% +intrinsic size associated with it okay + + + align:start position:0% +intrinsic size associated with it okay +you can sort of think of the objects + + align:start position:0% +you can sort of think of the objects + + + align:start position:0% +you can sort of think of the objects +whose luminosity you know about as + + align:start position:0% +whose luminosity you know about as + + + align:start position:0% +whose luminosity you know about as +standard candles imagine if nature + + align:start position:0% +standard candles imagine if nature + + + align:start position:0% +standard candles imagine if nature +builds standard yard sticks there's some + + align:start position:0% +builds standard yard sticks there's some + + + align:start position:0% +builds standard yard sticks there's some +object whose size you always know well + + align:start position:0% +object whose size you always know well + + + align:start position:0% +object whose size you always know well +let's compare that physical size to the + + align:start position:0% +let's compare that physical size to the + + + align:start position:0% +let's compare that physical size to the +angular size that you measure the angle + + align:start position:0% +angular size that you measure the angle + + + align:start position:0% +angular size that you measure the angle +that the object sub tends in the sky is + + align:start position:0% +that the object sub tends in the sky is + + + align:start position:0% +that the object sub tends in the sky is +going to be that intrinsic size Delta L + + align:start position:0% + + + + align:start position:0% + +divided by the distance we'll call this + + align:start position:0% +divided by the distance we'll call this + + + align:start position:0% +divided by the distance we'll call this +distance D sub a for the angular + + align:start position:0% +distance D sub a for the angular + + + align:start position:0% +distance D sub a for the angular +diameter distance + + align:start position:0% + + + + align:start position:0% + +and believe it or not nature in fact + + align:start position:0% +and believe it or not nature in fact + + + align:start position:0% +and believe it or not nature in fact +provides standard yardstick for the type + + align:start position:0% +provides standard yardstick for the type + + + align:start position:0% +provides standard yardstick for the type +so that we can we can actually do this + + align:start position:0% + + + + align:start position:0% + +finally at least as a matter of + + align:start position:0% +finally at least as a matter of + + + align:start position:0% +finally at least as a matter of +principle + + align:start position:0% +principle + + + align:start position:0% +principle +imagine you add some objects that's + + align:start position:0% +imagine you add some objects that's + + + align:start position:0% +imagine you add some objects that's +moving across the sky with a speed that + + align:start position:0% +moving across the sky with a speed that + + + align:start position:0% +moving across the sky with a speed that +you know you could compare that + + align:start position:0% + + + + align:start position:0% + +transverse speed to an apparent angular + + align:start position:0% +transverse speed to an apparent angular + + + align:start position:0% +transverse speed to an apparent angular +speed so the theta dot the angular speed + + align:start position:0% +speed so the theta dot the angular speed + + + align:start position:0% +speed so the theta dot the angular speed +that you measure that would be the + + align:start position:0% +that you measure that would be the + + + align:start position:0% +that you measure that would be the +velocity perpendicular to your + + align:start position:0% +velocity perpendicular to your + + + align:start position:0% +velocity perpendicular to your +line-of-sight divided by the distance + + align:start position:0% +line-of-sight divided by the distance + + + align:start position:0% +line-of-sight divided by the distance +we'll call this D sub M the proper + + align:start position:0% +we'll call this D sub M the proper + + + align:start position:0% +we'll call this D sub M the proper +motion distance + + align:start position:0% + + + + align:start position:0% + +so if our universe were Euclidean not + + align:start position:0% +so if our universe were Euclidean not + + + align:start position:0% +so if our universe were Euclidean not +only would it be easy for us to use + + align:start position:0% +only would it be easy for us to use + + + align:start position:0% +only would it be easy for us to use +these three bit measures of distance all + + align:start position:0% +these three bit measures of distance all + + + align:start position:0% +these three bit measures of distance all +three of them would give the same result + + align:start position:0% + + + + align:start position:0% + +this is all jazz geometry turns out when + + align:start position:0% +this is all jazz geometry turns out when + + + align:start position:0% +this is all jazz geometry turns out when +you study these notions of distance in + + align:start position:0% +you study these notions of distance in + + + align:start position:0% +you study these notions of distance in +an f RW spacetime there's some variation + + align:start position:0% +an f RW spacetime there's some variation + + + align:start position:0% +an f RW spacetime there's some variation +that enters let me just emphasize here + + align:start position:0% +that enters let me just emphasize here + + + align:start position:0% +that enters let me just emphasize here +that there is an excellent summary on + + align:start position:0% +that there is an excellent summary on + + + align:start position:0% +that there is an excellent summary on +this stuff I can't remember Phi the link + + align:start position:0% +this stuff I can't remember Phi the link + + + align:start position:0% +this stuff I can't remember Phi the link +this to the course website or not I + + align:start position:0% +this to the course website or not I + + + align:start position:0% +this to the course website or not I +shouldn't I shall an excellent summary + + align:start position:0% +shouldn't I shall an excellent summary + + + align:start position:0% +shouldn't I shall an excellent summary +of all this are really emphasizing + + align:start position:0% +of all this are really emphasizing + + + align:start position:0% +of all this are really emphasizing +observational e significant aspects of + + align:start position:0% +observational e significant aspects of + + + align:start position:0% +observational e significant aspects of +these things comes from the article that + + align:start position:0% +these things comes from the article that + + + align:start position:0% +these things comes from the article that +is on the archive called + + align:start position:0% +is on the archive called + + + align:start position:0% +is on the archive called +whoops distance measures in cosmology by + + align:start position:0% +whoops distance measures in cosmology by + + + align:start position:0% +whoops distance measures in cosmology by +David Hogg colleague at New York + + align:start position:0% +David Hogg colleague at New York + + + align:start position:0% +David Hogg colleague at New York +University you can find this on the + + align:start position:0% +University you can find this on the + + + align:start position:0% +University you can find this on the +astra ph archive 9905 + + align:start position:0% +astra ph archive 9905 + + + align:start position:0% +astra ph archive 9905 +one one six hard for me to believe this + + align:start position:0% +one one six hard for me to believe this + + + align:start position:0% +one one six hard for me to believe this +is almost twenty one twenty one years + + align:start position:0% +is almost twenty one twenty one years + + + align:start position:0% +is almost twenty one twenty one years +old now this is a gem of a paper hog + + align:start position:0% +old now this is a gem of a paper hog + + + align:start position:0% +old now this is a gem of a paper hog +never submitted to any journal just + + align:start position:0% +never submitted to any journal just + + + align:start position:0% +never submitted to any journal just +posted on the archive so that the + + align:start position:0% +posted on the archive so that the + + + align:start position:0% +posted on the archive so that the +community could take advantage of it um + + align:start position:0% +community could take advantage of it um + + + align:start position:0% +community could take advantage of it um +what we're going to do so the text book + + align:start position:0% +what we're going to do so the text book + + + align:start position:0% +what we're going to do so the text book +by carol goes through the calculation of + + align:start position:0% +by carol goes through the calculation of + + + align:start position:0% +by carol goes through the calculation of +d sub l on a problem set you will do d + + align:start position:0% +d sub l on a problem set you will do d + + + align:start position:0% +d sub l on a problem set you will do d +sub m we're going to go through d sub + + align:start position:0% +sub m we're going to go through d sub + + + align:start position:0% +sub m we're going to go through d sub +act just so you can see some of the the + + align:start position:0% +act just so you can see some of the the + + + align:start position:0% +act just so you can see some of the the +way that this works let me emphasize one + + align:start position:0% +way that this works let me emphasize one + + + align:start position:0% +way that this works let me emphasize one +thing all of these measures + + align:start position:0% + + + + align:start position:0% + +use the first Friedman equation okay so + + align:start position:0% +use the first Friedman equation okay so + + + align:start position:0% +use the first Friedman equation okay so +writing your Friedman equation like so I + + align:start position:0% +writing your Friedman equation like so I + + + align:start position:0% +writing your Friedman equation like so I +is a sum of all the different species of + + align:start position:0% +is a sum of all the different species of + + + align:start position:0% +is a sum of all the different species of +things that can contribute including + + align:start position:0% +things that can contribute including + + + align:start position:0% +things that can contribute including +curvature so recall that even though + + align:start position:0% +curvature so recall that even though + + + align:start position:0% +curvature so recall that even though +curvature isn't really a density you can + + align:start position:0% +curvature isn't really a density you can + + + align:start position:0% +curvature isn't really a density you can +combine enough factors to make it act as + + align:start position:0% +combine enough factors to make it act as + + + align:start position:0% +combine enough factors to make it act as +though it were a density you assume a + + align:start position:0% +though it were a density you assume a + + + align:start position:0% +though it were a density you assume a +parallel so this n sub I is related to + + align:start position:0% +parallel so this n sub I is related to + + + align:start position:0% +parallel so this n sub I is related to +the equation state parameter for each + + align:start position:0% +the equation state parameter for each + + + align:start position:0% +the equation state parameter for each +one of these species and let's now take + + align:start position:0% +one of these species and let's now take + + + align:start position:0% +one of these species and let's now take +advantage of the fact that we know the + + align:start position:0% +advantage of the fact that we know the + + + align:start position:0% +advantage of the fact that we know the +scale factor directly ties to redshift I + + align:start position:0% +scale factor directly ties to redshift I + + + align:start position:0% +scale factor directly ties to redshift I +can rewrite this as how the density of + + align:start position:0% +can rewrite this as how the density of + + + align:start position:0% +can rewrite this as how the density of +all's of the function of redshift so + + align:start position:0% +all's of the function of redshift so + + + align:start position:0% +all's of the function of redshift so +when you put all of this together + + align:start position:0% +when you put all of this together + + + align:start position:0% +when you put all of this together +this allows us to write H of a as H of Z + + align:start position:0% + + + + align:start position:0% + +this is given by the Hubble parameter + + align:start position:0% +this is given by the Hubble parameter + + + align:start position:0% +this is given by the Hubble parameter +now times some function e of Z + + align:start position:0% + + + + align:start position:0% + +and that is simply you sort of divide + + align:start position:0% +and that is simply you sort of divide + + + align:start position:0% +and that is simply you sort of divide +everything out to normalize to the + + align:start position:0% +everything out to normalize to the + + + align:start position:0% +everything out to normalize to the +critical density and that is a sum over + + align:start position:0% +critical density and that is a sum over + + + align:start position:0% +critical density and that is a sum over +all these densities with the with the + + align:start position:0% +all these densities with the with the + + + align:start position:0% +all these densities with the with the +redshift weighting like some so let me + + align:start position:0% +redshift weighting like some so let me + + + align:start position:0% +redshift weighting like some so let me +do an example like I said so if you read + + align:start position:0% +do an example like I said so if you read + + + align:start position:0% +do an example like I said so if you read +Carroll you will see the calculation of + + align:start position:0% +Carroll you will see the calculation of + + + align:start position:0% +Carroll you will see the calculation of +the luminosity distance if you do the + + align:start position:0% +the luminosity distance if you do the + + + align:start position:0% +the luminosity distance if you do the +cosmology problem sets that will be + + align:start position:0% +cosmology problem sets that will be + + + align:start position:0% +cosmology problem sets that will be +believe it's pset 8 you will explore the + + align:start position:0% +believe it's pset 8 you will explore the + + + align:start position:0% +believe it's pset 8 you will explore the +proper motion distance so let's do the + + align:start position:0% +proper motion distance so let's do the + + + align:start position:0% +proper motion distance so let's do the +angular diameter distance seeing someone + + align:start position:0% +angular diameter distance seeing someone + + + align:start position:0% +angular diameter distance seeing someone +work through this I think it's probably + + align:start position:0% +work through this I think it's probably + + + align:start position:0% +work through this I think it's probably +useful for helping to solidify the way + + align:start position:0% +useful for helping to solidify the way + + + align:start position:0% +useful for helping to solidify the way +in which these distance measures work + + align:start position:0% +in which these distance measures work + + + align:start position:0% +in which these distance measures work +and how how it is that one can tie + + align:start position:0% +and how how it is that one can tie + + + align:start position:0% +and how how it is that one can tie +together important observables so let's + + align:start position:0% +together important observables so let's + + + align:start position:0% +together important observables so let's +consider some source that we observe + + align:start position:0% +consider some source that we observe + + + align:start position:0% +consider some source that we observe +that according to us subtends an angle + + align:start position:0% +that according to us subtends an angle + + + align:start position:0% +that according to us subtends an angle +Delta Phi + + align:start position:0% + + + + align:start position:0% + +every spatial sector is spherically + + align:start position:0% +every spatial sector is spherically + + + align:start position:0% +every spatial sector is spherically +symmetric on and so we can orient our + + align:start position:0% +symmetric on and so we can orient our + + + align:start position:0% +symmetric on and so we can orient our +coordinate system so that this thing you + + align:start position:0% +coordinate system so that this thing you + + + align:start position:0% +coordinate system so that this thing you +know we're sort of a standard ruler what + + align:start position:0% +know we're sort of a standard ruler what + + + align:start position:0% +know we're sort of a standard ruler what +we're going to do is orient our + + align:start position:0% +we're going to do is orient our + + + align:start position:0% +we're going to do is orient our +coordinate systems so that that object + + align:start position:0% +coordinate systems so that that object + + + align:start position:0% +coordinate systems so that that object +lies in the theta equals PI over 2 plane + + align:start position:0% + + + + align:start position:0% + +ok the proper size of that source okay + + align:start position:0% +ok the proper size of that source okay + + + align:start position:0% +ok the proper size of that source okay +so this thing is just it's sitting in + + align:start position:0% +so this thing is just it's sitting in + + + align:start position:0% +so this thing is just it's sitting in +the sky there the proper size of the + + align:start position:0% +the sky there the proper size of the + + + align:start position:0% +the sky there the proper size of the +source you can get this in the line + + align:start position:0% +source you can get this in the line + + + align:start position:0% +source you can get this in the line +element the Delta L of the source will + + align:start position:0% +element the Delta L of the source will + + + align:start position:0% +element the Delta L of the source will +be the scale factor at the time at which + + align:start position:0% +be the scale factor at the time at which + + + align:start position:0% +be the scale factor at the time at which +it is emitted are zero okay so this is + + align:start position:0% +it is emitted are zero okay so this is + + + align:start position:0% +it is emitted are zero okay so this is +using one of the forms of the frw line + + align:start position:0% +using one of the forms of the frw line + + + align:start position:0% +using one of the forms of the frw line +elements I Pro it down the beginning of + + align:start position:0% +elements I Pro it down the beginning of + + + align:start position:0% +elements I Pro it down the beginning of +this lecture and so the angular diameter + + align:start position:0% +this lecture and so the angular diameter + + + align:start position:0% +this lecture and so the angular diameter +distance it's a quantity that I've + + align:start position:0% +distance it's a quantity that I've + + + align:start position:0% +distance it's a quantity that I've +defined over here it's just the ratio of + + align:start position:0% +defined over here it's just the ratio of + + + align:start position:0% +defined over here it's just the ratio of +this length to that angle + + align:start position:0% + + + + align:start position:0% + +okay let's rewrite this using the + + align:start position:0% +okay let's rewrite this using the + + + align:start position:0% +okay let's rewrite this using the +redshift redshift is something that I + + align:start position:0% +redshift redshift is something that I + + + align:start position:0% +redshift redshift is something that I +actually directly observe so there we go + + align:start position:0% + + + + align:start position:0% + +this is not wrong but it's flawed so + + align:start position:0% +this is not wrong but it's flawed so + + + align:start position:0% +this is not wrong but it's flawed so +this is true this is absolutely true + + align:start position:0% +this is true this is absolutely true + + + align:start position:0% +this is true this is absolutely true +here's the problem I don't know the + + align:start position:0% +here's the problem I don't know the + + + align:start position:0% +here's the problem I don't know the +overall scale of my universe and this + + align:start position:0% +overall scale of my universe and this + + + align:start position:0% +overall scale of my universe and this +coordinate chi doesn't really have an + + align:start position:0% +coordinate chi doesn't really have an + + + align:start position:0% +coordinate chi doesn't really have an +observable meaning to it okay it's how I + + align:start position:0% +observable meaning to it okay it's how I + + + align:start position:0% +observable meaning to it okay it's how I +label events but I look at some quasar + + align:start position:0% +label events but I look at some quasar + + + align:start position:0% +label events but I look at some quasar +in the sky and I'm like what's your chi + + align:start position:0% +in the sky and I'm like what's your chi + + + align:start position:0% +in the sky and I'm like what's your chi +so what we need to do is reformulate the + + align:start position:0% +so what we need to do is reformulate the + + + align:start position:0% +so what we need to do is reformulate the +numerator of this expression in such a + + align:start position:0% +numerator of this expression in such a + + + align:start position:0% +numerator of this expression in such a +way as to get rid of that chi and then + + align:start position:0% +way as to get rid of that chi and then + + + align:start position:0% +way as to get rid of that chi and then +see what happens see if we have a way to + + align:start position:0% +see what happens see if we have a way to + + + align:start position:0% +see what happens see if we have a way to +get rid of that r0 let's worry about Chi + + align:start position:0% +get rid of that r0 let's worry about Chi + + + align:start position:0% +get rid of that r0 let's worry about Chi +first we're going to eliminate it by + + align:start position:0% +first we're going to eliminate it by + + + align:start position:0% +first we're going to eliminate it by +taking advantage of the fact that the + + align:start position:0% +taking advantage of the fact that the + + + align:start position:0% +taking advantage of the fact that the +radiation I am measuring comes to me on + + align:start position:0% +radiation I am measuring comes to me on + + + align:start position:0% +radiation I am measuring comes to me on +a null path + + align:start position:0% + + + + align:start position:0% + +not to say anything all paths I'm gonna + + align:start position:0% +not to say anything all paths I'm gonna + + + align:start position:0% +not to say anything all paths I'm gonna +imagine it's a radial one okay we are + + align:start position:0% +imagine it's a radial one okay we are + + + align:start position:0% +imagine it's a radial one okay we are +allowed to be somewhat self-centered and + + align:start position:0% +allowed to be somewhat self-centered and + + + align:start position:0% +allowed to be somewhat self-centered and +defying the frw cosmology we put + + align:start position:0% +defying the frw cosmology we put + + + align:start position:0% +defying the frw cosmology we put +ourselves at the origin so any light + + align:start position:0% +ourselves at the origin so any light + + + align:start position:0% +ourselves at the origin so any light +that reaches us moves on a purely radial + + align:start position:0% +that reaches us moves on a purely radial + + + align:start position:0% +that reaches us moves on a purely radial +trajectory from its source to us so + + align:start position:0% +trajectory from its source to us so + + + align:start position:0% +trajectory from its source to us so +looking at how the time and the radial + + align:start position:0% +looking at how the time and the radial + + + align:start position:0% +looking at how the time and the radial +coordinate chi are related for a radial + + align:start position:0% +coordinate chi are related for a radial + + + align:start position:0% +coordinate chi are related for a radial +null path we go into my frw metric I get + + align:start position:0% +null path we go into my frw metric I get + + + align:start position:0% +null path we go into my frw metric I get +this so I can integrate this up to + + align:start position:0% +this so I can integrate this up to + + + align:start position:0% +this so I can integrate this up to +figure out what K is so this is right + + align:start position:0% +figure out what K is so this is right + + + align:start position:0% +figure out what K is so this is right +let's massage it a little bit to put it + + align:start position:0% +let's massage it a little bit to put it + + + align:start position:0% +let's massage it a little bit to put it +in a form it's a little bit more useful + + align:start position:0% +in a form it's a little bit more useful + + + align:start position:0% +in a form it's a little bit more useful +to us let's change our variable change + + align:start position:0% +to us let's change our variable change + + + align:start position:0% +to us let's change our variable change +our variable of integration from time to + + align:start position:0% +our variable of integration from time to + + + align:start position:0% +our variable of integration from time to +a so this will be an integral from the + + align:start position:0% +a so this will be an integral from the + + + align:start position:0% +a so this will be an integral from the +scale factor at which the radiation is + + align:start position:0% +scale factor at which the radiation is + + + align:start position:0% +scale factor at which the radiation is +emitted to the scale factor which we + + align:start position:0% +emitted to the scale factor which we + + + align:start position:0% +emitted to the scale factor which we +observe it ie now and we do that change + + align:start position:0% +observe it ie now and we do that change + + + align:start position:0% +observe it ie now and we do that change +of variables your integrals changes like + + align:start position:0% +of variables your integrals changes like + + + align:start position:0% +of variables your integrals changes like +so let's rewrite this once more to + + align:start position:0% +so let's rewrite this once more to + + + align:start position:0% +so let's rewrite this once more to +insert my Hubble parameter + + align:start position:0% + + + + align:start position:0% + +and let's change variables once more + + align:start position:0% +and let's change variables once more + + + align:start position:0% +and let's change variables once more +we're gonna use the fact that our direct + + align:start position:0% +we're gonna use the fact that our direct + + + align:start position:0% +we're gonna use the fact that our direct +measurable is redshift and so if we use + + align:start position:0% +measurable is redshift and so if we use + + + align:start position:0% +measurable is redshift and so if we use +a equals 1 over 1 plus C I can further + + align:start position:0% +a equals 1 over 1 plus C I can further + + + align:start position:0% +a equals 1 over 1 plus C I can further +write this as an integral over redshift + + align:start position:0% + + + + align:start position:0% + +like so and that h0 can come out of my + + align:start position:0% +like so and that h0 can come out of my + + + align:start position:0% +like so and that h0 can come out of my +integral so this is a form that is now + + align:start position:0% +integral so this is a form that is now + + + align:start position:0% +integral so this is a form that is now +finally formulated in terms of an + + align:start position:0% +finally formulated in terms of an + + + align:start position:0% +finally formulated in terms of an +observable redshift and my model + + align:start position:0% +observable redshift and my model + + + align:start position:0% +observable redshift and my model +dependent parameters + + align:start position:0% +dependent parameters + + + align:start position:0% +dependent parameters +okay the various omegas that when I + + align:start position:0% +okay the various omegas that when I + + + align:start position:0% +okay the various omegas that when I +construct my universe model I am free to + + align:start position:0% +construct my universe model I am free to + + + align:start position:0% +construct my universe model I am free to +set or if I am a phenomenologist that + + align:start position:0% +set or if I am a phenomenologist that + + + align:start position:0% +set or if I am a phenomenologist that +are going to be knobs that I turn to try + + align:start position:0% +are going to be knobs that I turn to try + + + align:start position:0% +are going to be knobs that I turn to try +to design a model universe that matches + + align:start position:0% +to design a model universe that matches + + + align:start position:0% +to design a model universe that matches +the data that I am measuring are zero + + align:start position:0% +the data that I am measuring are zero + + + align:start position:0% +the data that I am measuring are zero +though is still kind of annoying we + + align:start position:0% +though is still kind of annoying we + + + align:start position:0% +though is still kind of annoying we +don't know what this guy is so what we + + align:start position:0% +don't know what this guy is so what we + + + align:start position:0% +don't know what this guy is so what we +do is eliminate our 0 in favor of a + + align:start position:0% +do is eliminate our 0 in favor of a + + + align:start position:0% +do is eliminate our 0 in favor of a +curve curvature density parameter so + + align:start position:0% +curve curvature density parameter so + + + align:start position:0% +curve curvature density parameter so +using the fact that Omega curvature go + + align:start position:0% +using the fact that Omega curvature go + + + align:start position:0% +using the fact that Omega curvature go +back to how this was originally defined + + align:start position:0% +back to how this was originally defined + + + align:start position:0% +back to how this was originally defined +it was negative Kappa over H zero + + align:start position:0% +it was negative Kappa over H zero + + + align:start position:0% +it was negative Kappa over H zero +squared and that's negative K over r0 + + align:start position:0% +squared and that's negative K over r0 + + + align:start position:0% +squared and that's negative K over r0 +squared H zero squared + + align:start position:0% + + + + align:start position:0% + +that tells me that r0 is the Hubble + + align:start position:0% +that tells me that r0 is the Hubble + + + align:start position:0% +that tells me that r0 is the Hubble +constant now divided by the square root + + align:start position:0% +constant now divided by the square root + + + align:start position:0% +constant now divided by the square root +of the absolute value of the curvature + + align:start position:0% +of the absolute value of the curvature + + + align:start position:0% +of the absolute value of the curvature +at least if K equals plus or minus one + + align:start position:0% +at least if K equals plus or minus one + + + align:start position:0% +at least if K equals plus or minus one +what happens when it's not plus or minus + + align:start position:0% +what happens when it's not plus or minus + + + align:start position:0% +what happens when it's not plus or minus +one okay if it's equal to zero well hold + + align:start position:0% +one okay if it's equal to zero well hold + + + align:start position:0% +one okay if it's equal to zero well hold +that thought okay so let's put all these + + align:start position:0% +that thought okay so let's put all these + + + align:start position:0% +that thought okay so let's put all these +pieces together so assembling all the + + align:start position:0% +pieces together so assembling all the + + + align:start position:0% +pieces together so assembling all the +ingredients I have here what we find is + + align:start position:0% +ingredients I have here what we find is + + + align:start position:0% +ingredients I have here what we find is +the angular diameter distance there's a + + align:start position:0% +the angular diameter distance there's a + + + align:start position:0% +the angular diameter distance there's a +factor of 1 over 1 plus c1 over the + + align:start position:0% +factor of 1 over 1 plus c1 over the + + + align:start position:0% +factor of 1 over 1 plus c1 over the +Hubble constant remember Hubble has + + align:start position:0% +Hubble constant remember Hubble has + + + align:start position:0% +Hubble constant remember Hubble has +units of 1 over length excuse me 1 over + + align:start position:0% +units of 1 over length excuse me 1 over + + + align:start position:0% +units of 1 over length excuse me 1 over +time and with the factor of the speed of + + align:start position:0% +time and with the factor of the speed of + + + align:start position:0% +time and with the factor of the speed of +light that is a 1 over length so 1 over + + align:start position:0% +light that is a 1 over length so 1 over + + + align:start position:0% +light that is a 1 over length so 1 over +the Hubble parameter now is essentially + + align:start position:0% +the Hubble parameter now is essentially + + + align:start position:0% +the Hubble parameter now is essentially +a kind of fiducial overall distance + + align:start position:0% +a kind of fiducial overall distance + + + align:start position:0% +a kind of fiducial overall distance +scale and then our solution breaks up + + align:start position:0% +scale and then our solution breaks up + + + align:start position:0% +scale and then our solution breaks up +into three branches depending upon what + + align:start position:0% +into three branches depending upon what + + + align:start position:0% +into three branches depending upon what +the weather K equals minus 1 0 or 1 so + + align:start position:0% +the weather K equals minus 1 0 or 1 so + + + align:start position:0% +the weather K equals minus 1 0 or 1 so +you get one term where it involves minus + + align:start position:0% +you get one term where it involves minus + + + align:start position:0% +you get one term where it involves minus +square root the absolute value of the + + align:start position:0% +square root the absolute value of the + + + align:start position:0% +square root the absolute value of the +curvature parameter times sine of that + + align:start position:0% +curvature parameter times sine of that + + + align:start position:0% +curvature parameter times sine of that +same absolute value of the curvature + + align:start position:0% +same absolute value of the curvature + + + align:start position:0% +same absolute value of the curvature +parameters square root + + align:start position:0% + + + + align:start position:0% + +so here's your K equals +1 branch for + + align:start position:0% +so here's your K equals +1 branch for + + + align:start position:0% +so here's your K equals +1 branch for +your k equals zero branch basically what + + align:start position:0% +your k equals zero branch basically what + + + align:start position:0% +your k equals zero branch basically what +you'll find when you plug in your s of K + + align:start position:0% +you'll find when you plug in your s of K + + + align:start position:0% +you'll find when you plug in your s of K +is that r0 cancels out okay so that ends + + align:start position:0% +is that r0 cancels out okay so that ends + + + align:start position:0% +is that r0 cancels out okay so that ends +up being a parameter you do not need to + + align:start position:0% +up being a parameter you do not need to + + + align:start position:0% +up being a parameter you do not need to +worry about and I suggest you just work + + align:start position:0% +worry about and I suggest you just work + + + align:start position:0% +worry about and I suggest you just work +through the algebra and you'll find it + + align:start position:0% +through the algebra and you'll find it + + + align:start position:0% +through the algebra and you'll find it +in for K equals zero it simply looks + + align:start position:0% +in for K equals zero it simply looks + + + align:start position:0% +in for K equals zero it simply looks +like this and then finally if you are in + + align:start position:0% +like this and then finally if you are in + + + align:start position:0% +like this and then finally if you are in +an open universe supposed to be + + align:start position:0% +an open universe supposed to be + + + align:start position:0% +an open universe supposed to be +curvature + + align:start position:0% + + + + align:start position:0% + +what we get is this so this is a + + align:start position:0% +what we get is this so this is a + + + align:start position:0% +what we get is this so this is a +distance measure that tells me how + + align:start position:0% +distance measure that tells me how + + + align:start position:0% +distance measure that tells me how +angular diameter distance it depends on + + align:start position:0% +angular diameter distance it depends on + + + align:start position:0% +angular diameter distance it depends on +observable parameters Hubble is + + align:start position:0% +observable parameters Hubble is + + + align:start position:0% +observable parameters Hubble is +something that we can measure redshift + + align:start position:0% +something that we can measure redshift + + + align:start position:0% +something that we can measure redshift +is something we can measure and it + + align:start position:0% +is something we can measure and it + + + align:start position:0% +is something we can measure and it +depends on model parameters the + + align:start position:0% +depends on model parameters the + + + align:start position:0% +depends on model parameters the +different densities that go into e of Z + + align:start position:0% +different densities that go into e of Z + + + align:start position:0% +different densities that go into e of Z +and which I have on the board right here + + align:start position:0% + + + + align:start position:0% + +the different densities to go into e of + + align:start position:0% +the different densities to go into e of + + + align:start position:0% +the different densities to go into e of +Z my apologies I left out that H o there + + align:start position:0% +Z my apologies I left out that H o there + + + align:start position:0% +Z my apologies I left out that H o there +and your choice of the curvature when + + align:start position:0% +and your choice of the curvature when + + + align:start position:0% +and your choice of the curvature when +you analyze these three distances here's + + align:start position:0% +you analyze these three distances here's + + + align:start position:0% +you analyze these three distances here's +what you find + + align:start position:0% + + + + align:start position:0% + +and find that the luminosity distance is + + align:start position:0% +and find that the luminosity distance is + + + align:start position:0% +and find that the luminosity distance is +related to the proper motion distance by + + align:start position:0% +related to the proper motion distance by + + + align:start position:0% +related to the proper motion distance by +a factor of 1 plus Z and that's related + + align:start position:0% +a factor of 1 plus Z and that's related + + + align:start position:0% +a factor of 1 plus Z and that's related +to the angular diameter distance by a + + align:start position:0% +to the angular diameter distance by a + + + align:start position:0% +to the angular diameter distance by a +factor of 1 plus Z squared + + align:start position:0% +factor of 1 plus Z squared + + + align:start position:0% +factor of 1 plus Z squared +so when you read Carroll you will find + + align:start position:0% +so when you read Carroll you will find + + + align:start position:0% +so when you read Carroll you will find +that that 1 plus Z factor there that + + align:start position:0% +that that 1 plus Z factor there that + + + align:start position:0% +that that 1 plus Z factor there that +sumi 1 plus Z to the minus 1 power turns + + align:start position:0% +sumi 1 plus Z to the minus 1 power turns + + + align:start position:0% +sumi 1 plus Z to the minus 1 power turns +into a 1 plus Z so that camp that 1 plus + + align:start position:0% +into a 1 plus Z so that camp that 1 plus + + + align:start position:0% +into a 1 plus Z so that camp that 1 plus +Z 1 over 1 plus e turns into a 1 plus Z + + align:start position:0% +Z 1 over 1 plus e turns into a 1 plus Z + + + align:start position:0% +Z 1 over 1 plus e turns into a 1 plus Z +and when you do it on the pset you do + + align:start position:0% +and when you do it on the pset you do + + + align:start position:0% +and when you do it on the pset you do +the proper motion distance there will + + align:start position:0% +the proper motion distance there will + + + align:start position:0% +the proper motion distance there will +just be no 1 plus Z factor in front of + + align:start position:0% +just be no 1 plus Z factor in front of + + + align:start position:0% +just be no 1 plus Z factor in front of +everything so the name of the game when + + align:start position:0% +everything so the name of the game when + + + align:start position:0% +everything so the name of the game when +one is doing cosmology as a physicist is + + align:start position:0% +one is doing cosmology as a physicist is + + + align:start position:0% +one is doing cosmology as a physicist is +to find quantities that you can measure + + align:start position:0% +to find quantities that you can measure + + + align:start position:0% +to find quantities that you can measure +that allow you to determine luminosity + + align:start position:0% +that allow you to determine luminosity + + + align:start position:0% +that allow you to determine luminosity +distances angular diameter distances + + align:start position:0% +distances angular diameter distances + + + align:start position:0% +distances angular diameter distances +proper motion distances now it turns out + + align:start position:0% +proper motion distances now it turns out + + + align:start position:0% +proper motion distances now it turns out +that the proper motion distance is not a + + align:start position:0% +that the proper motion distance is not a + + + align:start position:0% +that the proper motion distance is not a +very practical one for most for + + align:start position:0% +very practical one for most for + + + align:start position:0% +very practical one for most for +basically any cosmological interesting + + align:start position:0% +basically any cosmological interesting + + + align:start position:0% +basically any cosmological interesting +source they are simply so far away that + + align:start position:0% +source they are simply so far away that + + + align:start position:0% +source they are simply so far away that +even for a source moving essentially at + + align:start position:0% +even for a source moving essentially at + + + align:start position:0% +even for a source moving essentially at +the speed of light the amount of angular + + align:start position:0% +the speed of light the amount of angular + + + align:start position:0% +the speed of light the amount of angular +motion that can be seen over essentially + + align:start position:0% +motion that can be seen over essentially + + + align:start position:0% +motion that can be seen over essentially +a human lifetime is negligible so this + + align:start position:0% +a human lifetime is negligible so this + + + align:start position:0% +a human lifetime is negligible so this +turns into something that high that's + + align:start position:0% +turns into something that high that's + + + align:start position:0% +turns into something that high that's +okay yeah I'm doing some pre recording + + align:start position:0% +okay yeah I'm doing some pre recording + + + align:start position:0% +okay yeah I'm doing some pre recording +of lectures no I was warned you guys + + align:start position:0% +of lectures no I was warned you guys + + + align:start position:0% +of lectures no I was warned you guys +might come by I have my ID with me and + + align:start position:0% +might come by I have my ID with me and + + + align:start position:0% +might come by I have my ID with me and +things like that so appreciate it so + + align:start position:0% +things like that so appreciate it so + + + align:start position:0% +things like that so appreciate it so +those of you watching the video at home + + align:start position:0% +those of you watching the video at home + + + align:start position:0% +those of you watching the video at home +as you can see the MIT police is keeping + + align:start position:0% +as you can see the MIT police is keeping + + + align:start position:0% +as you can see the MIT police is keeping +us safe ah scared the crap out of me for + + align:start position:0% +us safe ah scared the crap out of me for + + + align:start position:0% +us safe ah scared the crap out of me for +a second there but it's all good all + + align:start position:0% +a second there but it's all good all + + + align:start position:0% +a second there but it's all good all +right so let's go back to this for a + + align:start position:0% +right so let's go back to this for a + + + align:start position:0% +right so let's go back to this for a +second so the proper motion distance is + + align:start position:0% +second so the proper motion distance is + + + align:start position:0% +second so the proper motion distance is +something that is not particularly + + align:start position:0% +something that is not particularly + + + align:start position:0% +something that is not particularly +practical because as I said even if you + + align:start position:0% +practical because as I said even if you + + + align:start position:0% +practical because as I said even if you +have an object that is moving close to + + align:start position:0% +have an object that is moving close to + + + align:start position:0% +have an object that is moving close to +the speed of light + + align:start position:0% +the speed of light + + + align:start position:0% +the speed of light +this is not something that even over the + + align:start position:0% +this is not something that even over the + + + align:start position:0% +this is not something that even over the +course of a human lifetime you are + + align:start position:0% +course of a human lifetime you are + + + align:start position:0% +course of a human lifetime you are +likely to see a significant angular + + align:start position:0% +likely to see a significant angular + + + align:start position:0% +likely to see a significant angular +motion so this is gently not used but + + align:start position:0% +motion so this is gently not used but + + + align:start position:0% +motion so this is gently not used but +luminosity distances and angular + + align:start position:0% +luminosity distances and angular + + + align:start position:0% +luminosity distances and angular +diameter distances that is in fact + + align:start position:0% +diameter distances that is in fact + + + align:start position:0% +diameter distances that is in fact +extremely important and a lot of + + align:start position:0% +extremely important and a lot of + + + align:start position:0% +extremely important and a lot of +cosmology is based on looking for well + + align:start position:0% +cosmology is based on looking for well + + + align:start position:0% +cosmology is based on looking for well +understood well understood objects where + + align:start position:0% +understood well understood objects where + + + align:start position:0% +understood well understood objects where +we can calibrate the physical size and + + align:start position:0% +we can calibrate the physical size and + + + align:start position:0% +we can calibrate the physical size and +infer the angular diameter distance or + + align:start position:0% +infer the angular diameter distance or + + + align:start position:0% +infer the angular diameter distance or +we know the intrinsic brightness and we + + align:start position:0% +we know the intrinsic brightness and we + + + align:start position:0% +we know the intrinsic brightness and we +can determine the luminosity distance so + + align:start position:0% +can determine the luminosity distance so + + + align:start position:0% +can determine the luminosity distance so +let me just give a a quick snapshot of + + align:start position:0% +let me just give a a quick snapshot of + + + align:start position:0% +let me just give a a quick snapshot of +where the measurements come from in + + align:start position:0% +where the measurements come from in + + + align:start position:0% +where the measurements come from in +modern cosmology that are driving our + + align:start position:0% +modern cosmology that are driving our + + + align:start position:0% +modern cosmology that are driving our +cosmological model so one of the most + + align:start position:0% +cosmological model so one of the most + + + align:start position:0% +cosmological model so one of the most +important is the Cosmic Microwave + + align:start position:0% +important is the Cosmic Microwave + + + align:start position:0% +important is the Cosmic Microwave +Background so vastly oversimplifying + + align:start position:0% +Background so vastly oversimplifying + + + align:start position:0% +Background so vastly oversimplifying +when we look at the Cosmic Microwave + + align:start position:0% +when we look at the Cosmic Microwave + + + align:start position:0% +when we look at the Cosmic Microwave +Background after sort of removing + + align:start position:0% +Background after sort of removing + + + align:start position:0% +Background after sort of removing +removing things like the the flow of our + + align:start position:0% +removing things like the the flow of our + + + align:start position:0% +removing things like the the flow of our +solar system with respect to the the + + align:start position:0% +solar system with respect to the the + + + align:start position:0% +solar system with respect to the the +rest frame of to meet the the comoving + + align:start position:0% +rest frame of to meet the the comoving + + + align:start position:0% +rest frame of to meet the the comoving +reference frame of the cause of the the + + align:start position:0% +reference frame of the cause of the the + + + align:start position:0% +reference frame of the cause of the the +fluid that makes up our universe the + + align:start position:0% +fluid that makes up our universe the + + + align:start position:0% +fluid that makes up our universe the +size of hot and cold spots is a standard + + align:start position:0% +size of hot and cold spots is a standard + + + align:start position:0% +size of hot and cold spots is a standard +ruler + + align:start position:0% + + + + align:start position:0% + +by looking at the distribution of sizes + + align:start position:0% +by looking at the distribution of sizes + + + align:start position:0% +by looking at the distribution of sizes +that we see from these things we can + + align:start position:0% +that we see from these things we can + + + align:start position:0% +that we see from these things we can +determine the angular diameter distance + + align:start position:0% +determine the angular diameter distance + + + align:start position:0% +determine the angular diameter distance +to the Cosmic Microwave Background with + + align:start position:0% +to the Cosmic Microwave Background with + + + align:start position:0% +to the Cosmic Microwave Background with +very high precision this ends up being + + align:start position:0% +very high precision this ends up being + + + align:start position:0% +very high precision this ends up being +one of the most important constraints on + + align:start position:0% +one of the most important constraints on + + + align:start position:0% +one of the most important constraints on +determining what the curvature parameter + + align:start position:0% +determining what the curvature parameter + + + align:start position:0% +determining what the curvature parameter +actually is and it is largely thanks to + + align:start position:0% +actually is and it is largely thanks to + + + align:start position:0% +actually is and it is largely thanks to +the Cosmic Microwave Background that + + align:start position:0% +the Cosmic Microwave Background that + + + align:start position:0% +the Cosmic Microwave Background that +current prejudice I would say the + + align:start position:0% +current prejudice I would say the + + + align:start position:0% +current prejudice I would say the +current best wisdom choose your your + + align:start position:0% +current best wisdom choose your your + + + align:start position:0% +current best wisdom choose your your +descriptor as you wish is that K equals + + align:start position:0% +descriptor as you wish is that K equals + + + align:start position:0% +descriptor as you wish is that K equals +zero in our universe is in fact + + align:start position:0% +zero in our universe is in fact + + + align:start position:0% +zero in our universe is in fact +spatially flat second one is what are + + align:start position:0% +spatially flat second one is what are + + + align:start position:0% +spatially flat second one is what are +called type 1a supernovae these are + + align:start position:0% +called type 1a supernovae these are + + + align:start position:0% +called type 1a supernovae these are +essentially the the thermo nuclear + + align:start position:0% +essentially the the thermo nuclear + + + align:start position:0% +essentially the the thermo nuclear +detonations of white dwarfs it's not + + align:start position:0% +detonations of white dwarfs it's not + + + align:start position:0% +detonations of white dwarfs it's not +even released thermonuclear it's just my + + align:start position:0% +even released thermonuclear it's just my + + + align:start position:0% +even released thermonuclear it's just my +apologies I'm confusing a different + + align:start position:0% +apologies I'm confusing a different + + + align:start position:0% +apologies I'm confusing a different +event that involves white dwarfs the + + align:start position:0% +event that involves white dwarfs the + + + align:start position:0% +event that involves white dwarfs the +type 1 days are not the thermonuclear + + align:start position:0% +type 1 days are not the thermonuclear + + + align:start position:0% +type 1 days are not the thermonuclear +explosions of these things this is + + align:start position:0% +explosions of these things this is + + + align:start position:0% +explosions of these things this is +actually the core collapse of a white + + align:start position:0% +actually the core collapse of a white + + + align:start position:0% +actually the core collapse of a white +dwarf star so this is what happens when + + align:start position:0% +dwarf star so this is what happens when + + + align:start position:0% +dwarf star so this is what happens when +a white dwarf it creats or in some way + + align:start position:0% +a white dwarf it creats or in some way + + + align:start position:0% +a white dwarf it creats or in some way +accumulates enough mass such that it can + + align:start position:0% +accumulates enough mass such that it can + + + align:start position:0% +accumulates enough mass such that it can +no longer electron degeneracy pressure + + align:start position:0% +no longer electron degeneracy pressure + + + align:start position:0% +no longer electron degeneracy pressure +is no longer sufficient to hold it + + align:start position:0% +is no longer sufficient to hold it + + + align:start position:0% +is no longer sufficient to hold it +against gravitational collapse and the + + align:start position:0% +against gravitational collapse and the + + + align:start position:0% +against gravitational collapse and the +whole thing basically collapses into a + + align:start position:0% +whole thing basically collapses into a + + + align:start position:0% +whole thing basically collapses into a +neutron star that happens at a defined + + align:start position:0% +neutron star that happens at a defined + + + align:start position:0% +neutron star that happens at a defined +mass the Chandrasekar mass named after + + align:start position:0% +mass the Chandrasekar mass named after + + + align:start position:0% +mass the Chandrasekar mass named after +one of my scientific heroes Subramanya + + align:start position:0% +one of my scientific heroes Subramanya + + + align:start position:0% +one of my scientific heroes Subramanya +and Chandra Sekhar and because it sort + + align:start position:0% +and Chandra Sekhar and because it sort + + + align:start position:0% +and Chandra Sekhar and because it sort +of has a defined mass associated with it + + align:start position:0% +of has a defined mass associated with it + + + align:start position:0% +of has a defined mass associated with it +every event basically has the same + + align:start position:0% +every event basically has the same + + + align:start position:0% +every event basically has the same +amount of matter participating this is a + + align:start position:0% +amount of matter participating this is a + + + align:start position:0% +amount of matter participating this is a +standard candle + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +let's see so there's a couple others and + + align:start position:0% +let's see so there's a couple others and + + + align:start position:0% +let's see so there's a couple others and +I'm not gonna talk about in too much + + align:start position:0% +I'm not gonna talk about in too much + + + align:start position:0% +I'm not gonna talk about in too much +detail here while I'm erasing the board + + align:start position:0% +detail here while I'm erasing the board + + + align:start position:0% +detail here while I'm erasing the board +I would just mention them so by looking + + align:start position:0% +I would just mention them so by looking + + + align:start position:0% +I would just mention them so by looking +at things like the clustering of + + align:start position:0% +at things like the clustering of + + + align:start position:0% +at things like the clustering of +galaxies we can measure the distribution + + align:start position:0% +galaxies we can measure the distribution + + + align:start position:0% +galaxies we can measure the distribution +of mass in the universe that allows us + + align:start position:0% +of mass in the universe that allows us + + + align:start position:0% +of mass in the universe that allows us +to determine the Omega M parameter + + align:start position:0% +to determine the Omega M parameter + + + align:start position:0% +to determine the Omega M parameter +that's one of the bits of information + + align:start position:0% +that's one of the bits of information + + + align:start position:0% +that's one of the bits of information +that tells us that much of the universe + + align:start position:0% +that tells us that much of the universe + + + align:start position:0% +that tells us that much of the universe +is made of matter that apparently does + + align:start position:0% +is made of matter that apparently does + + + align:start position:0% +is made of matter that apparently does +not participate in standard model + + align:start position:0% +not participate in standard model + + + align:start position:0% +not participate in standard model +processes as we know them today the + + align:start position:0% +processes as we know them today the + + + align:start position:0% +processes as we know them today the +so-called Dark Matter problem we can + + align:start position:0% +so-called Dark Matter problem we can + + + align:start position:0% +so-called Dark Matter problem we can +look at chemical abundances which tells + + align:start position:0% +look at chemical abundances which tells + + + align:start position:0% +look at chemical abundances which tells +us about the behavior of nuclear + + align:start position:0% +us about the behavior of nuclear + + + align:start position:0% +us about the behavior of nuclear +processes in the very early universe and + + align:start position:0% +processes in the very early universe and + + + align:start position:0% +processes in the very early universe and +the last ones I will mention here is we + + align:start position:0% +the last ones I will mention here is we + + + align:start position:0% +the last ones I will mention here is we +can look at nearby + + align:start position:0% +can look at nearby + + + align:start position:0% +can look at nearby +standard candles and nearby standard + + align:start position:0% +standard candles and nearby standard + + + align:start position:0% +standard candles and nearby standard +candles allow us to probe the local + + align:start position:0% +candles allow us to probe the local + + + align:start position:0% +candles allow us to probe the local +Hubble law and determine h0 combined + + align:start position:0% +Hubble law and determine h0 combined + + + align:start position:0% +Hubble law and determine h0 combined +probe and hubble probe okay and when I + + align:start position:0% +probe and hubble probe okay and when I + + + align:start position:0% +probe and hubble probe okay and when I +say nearby that usually means events + + align:start position:0% +say nearby that usually means events + + + align:start position:0% +say nearby that usually means events +that are merely a few tens of millions + + align:start position:0% +that are merely a few tens of millions + + + align:start position:0% +that are merely a few tens of millions +of light years away it's worth noting + + align:start position:0% +of light years away it's worth noting + + + align:start position:0% +of light years away it's worth noting +that all of these various techniques all + + align:start position:0% +that all of these various techniques all + + + align:start position:0% +that all of these various techniques all +of these different things you can kind + + align:start position:0% +of these different things you can kind + + + align:start position:0% +of these different things you can kind +of even see it when you think about the + + align:start position:0% +of even see it when you think about the + + + align:start position:0% +of even see it when you think about the +mathematical form of everything that + + align:start position:0% +mathematical form of everything that + + + align:start position:0% +mathematical form of everything that +went into our distance measures they're + + align:start position:0% +went into our distance measures they're + + + align:start position:0% +went into our distance measures they're +all highly entangled with each other and + + align:start position:0% +all highly entangled with each other and + + + align:start position:0% +all highly entangled with each other and +so to do this kind of thing properly you + + align:start position:0% +so to do this kind of thing properly you + + + align:start position:0% +so to do this kind of thing properly you +need to take just a crapload of data + + align:start position:0% +need to take just a crapload of data + + + align:start position:0% +need to take just a crapload of data +combine all of your data sets and do a + + align:start position:0% +combine all of your data sets and do a + + + align:start position:0% +combine all of your data sets and do a +joint analysis of everything looking at + + align:start position:0% +joint analysis of everything looking at + + + align:start position:0% +joint analysis of everything looking at +the way varying the parameters and all + + align:start position:0% +the way varying the parameters and all + + + align:start position:0% +the way varying the parameters and all +the different models affects the outcome + + align:start position:0% +the different models affects the outcome + + + align:start position:0% +the different models affects the outcome +of your observables + + align:start position:0% + + + + align:start position:0% + +you also have to carefully take into + + align:start position:0% +you also have to carefully take into + + + align:start position:0% +you also have to carefully take into +account the fact that when you measure + + align:start position:0% +account the fact that when you measure + + + align:start position:0% +account the fact that when you measure +something you measure it with errors and + + align:start position:0% +something you measure it with errors and + + + align:start position:0% +something you measure it with errors and +so you know many of these things are not + + align:start position:0% +so you know many of these things are not + + + align:start position:0% +so you know many of these things are not +known turns out you can usually measure + + align:start position:0% +known turns out you can usually measure + + + align:start position:0% +known turns out you can usually measure +redshift quite precisely but these + + align:start position:0% +redshift quite precisely but these + + + align:start position:0% +redshift quite precisely but these +distances always come with some error + + align:start position:0% +distances always come with some error + + + align:start position:0% +distances always come with some error +bar associated with them and so that + + align:start position:0% +bar associated with them and so that + + + align:start position:0% +bar associated with them and so that +means that the distance you associate + + align:start position:0% +means that the distance you associate + + + align:start position:0% +means that the distance you associate +with a particular redshift which is + + align:start position:0% +with a particular redshift which is + + + align:start position:0% +with a particular redshift which is +equivalent to associating a time with a + + align:start position:0% +equivalent to associating a time with a + + + align:start position:0% +equivalent to associating a time with a +redshift you know there's some error bar + + align:start position:0% +redshift you know there's some error bar + + + align:start position:0% +redshift you know there's some error bar +on that and that can lead to significant + + align:start position:0% +on that and that can lead to significant + + + align:start position:0% +on that and that can lead to significant +skew and what you determined from things + + align:start position:0% +skew and what you determined from things + + + align:start position:0% +skew and what you determined from things +so there's a lot more we could say but + + align:start position:0% +so there's a lot more we could say but + + + align:start position:0% +so there's a lot more we could say but +time is finite and we need to change + + align:start position:0% +time is finite and we need to change + + + align:start position:0% +time is finite and we need to change +topic so I'm going to conclude this + + align:start position:0% +topic so I'm going to conclude this + + + align:start position:0% +topic so I'm going to conclude this +lecture by talking about two mysteries + + align:start position:0% +lecture by talking about two mysteries + + + align:start position:0% +lecture by talking about two mysteries +in the cosmological model that have been + + align:start position:0% +in the cosmological model that have been + + + align:start position:0% +in the cosmological model that have been +the focus of a lot of research attention + + align:start position:0% +the focus of a lot of research attention + + + align:start position:0% +the focus of a lot of research attention +over the past several decades so two + + align:start position:0% +over the past several decades so two + + + align:start position:0% +over the past several decades so two +mysteries one why is it that our + + align:start position:0% +mysteries one why is it that our + + + align:start position:0% +mysteries one why is it that our +universe appears to be flat spatially + + align:start position:0% +universe appears to be flat spatially + + + align:start position:0% +universe appears to be flat spatially +flat + + align:start position:0% + + + + align:start position:0% + +so the frame why this is a bit of a + + align:start position:0% +so the frame why this is a bit of a + + + align:start position:0% +so the frame why this is a bit of a +mystery if you didn't sort of go come on + + align:start position:0% +mystery if you didn't sort of go come on + + + align:start position:0% +mystery if you didn't sort of go come on +you know you just you've got three + + align:start position:0% +you know you just you've got three + + + align:start position:0% +you know you just you've got three +choices for the parameter you got zero + + align:start position:0% +choices for the parameter you got zero + + + align:start position:0% +choices for the parameter you got zero +well let's begin by thinking about the + + align:start position:0% +well let's begin by thinking about the + + + align:start position:0% +well let's begin by thinking about the +first Freedman equation I can write this + + align:start position:0% +first Freedman equation I can write this + + + align:start position:0% +first Freedman equation I can write this +like so or I can use this form where I + + align:start position:0% +like so or I can use this form where I + + + align:start position:0% +like so or I can use this form where I +say Omega plus Omega curvature I'm just + + align:start position:0% +say Omega plus Omega curvature I'm just + + + align:start position:0% +say Omega plus Omega curvature I'm just +gonna call that Omega C for now that + + align:start position:0% +gonna call that Omega C for now that + + + align:start position:0% +gonna call that Omega C for now that +equals one the expectation had long been + + align:start position:0% +equals one the expectation had long been + + + align:start position:0% +equals one the expectation had long been +that our universe would basically be + + align:start position:0% +that our universe would basically be + + + align:start position:0% +that our universe would basically be +dominated by various species of matter + + align:start position:0% +dominated by various species of matter + + + align:start position:0% +dominated by various species of matter +and radiation for much of its history + + align:start position:0% +and radiation for much of its history + + + align:start position:0% +and radiation for much of its history +especially in the early universe + + align:start position:0% + + + + align:start position:0% + +it's awful was radiation-dominated you + + align:start position:0% +it's awful was radiation-dominated you + + + align:start position:0% +it's awful was radiation-dominated you +would expect it's the density to go as a + + align:start position:0% +would expect it's the density to go as a + + + align:start position:0% +would expect it's the density to go as a +to the minus four and if it's + + align:start position:0% +to the minus four and if it's + + + align:start position:0% +to the minus four and if it's +matter-dominated you expected to go is a + + align:start position:0% +matter-dominated you expected to go is a + + + align:start position:0% +matter-dominated you expected to go is a +to the minus three now your curvature + + align:start position:0% +to the minus three now your curvature + + + align:start position:0% +to the minus three now your curvature +density goes as a to the minus two + + align:start position:0% + + + + align:start position:0% + +and so what this means that is that if + + align:start position:0% +and so what this means that is that if + + + align:start position:0% +and so what this means that is that if +you look at the ratio of Omega curvature + + align:start position:0% +you look at the ratio of Omega curvature + + + align:start position:0% +you look at the ratio of Omega curvature +to Omega this will be proportional to a + + align:start position:0% + + + + align:start position:0% + +formatter a squared for radiation if + + align:start position:0% +formatter a squared for radiation if + + + align:start position:0% +formatter a squared for radiation if +your universe it just you know in some + + align:start position:0% +your universe it just you know in some + + + align:start position:0% +your universe it just you know in some +sense looking at these parameter K of + + align:start position:0% +sense looking at these parameter K of + + + align:start position:0% +sense looking at these parameter K of +the minus 1 0 1 that's a little bit + + align:start position:0% +the minus 1 0 1 that's a little bit + + + align:start position:0% +the minus 1 0 1 that's a little bit +misleading it's probably a little bit + + align:start position:0% +misleading it's probably a little bit + + + align:start position:0% +misleading it's probably a little bit +more useful to think about things in + + align:start position:0% +more useful to think about things in + + + align:start position:0% +more useful to think about things in +terms of the Kappa parameter and when + + align:start position:0% +terms of the Kappa parameter and when + + + align:start position:0% +terms of the Kappa parameter and when +you look at that your flat universe is a + + align:start position:0% +you look at that your flat universe is a + + + align:start position:0% +you look at that your flat universe is a +set of measure 0 in the set of all + + align:start position:0% +set of measure 0 in the set of all + + + align:start position:0% +set of measure 0 in the set of all +possible curvature parameters that you + + align:start position:0% +possible curvature parameters that you + + + align:start position:0% +possible curvature parameters that you +could have and physicists tend to get + + align:start position:0% +could have and physicists tend to get + + + align:start position:0% +could have and physicists tend to get +suspicious when something that you know + + align:start position:0% +suspicious when something that you know + + + align:start position:0% +suspicious when something that you know +could take on any range of possible + + align:start position:0% +could take on any range of possible + + + align:start position:0% +could take on any range of possible +random values between minus infinity and + + align:start position:0% +random values between minus infinity and + + + align:start position:0% +random values between minus infinity and +infinity picks out 0 that tends to tell + + align:start position:0% +infinity picks out 0 that tends to tell + + + align:start position:0% +infinity picks out 0 that tends to tell +us that there may be some principle at + + align:start position:0% +us that there may be some principle at + + + align:start position:0% +us that there may be some principle at +play that actually drives things to + + align:start position:0% +play that actually drives things to + + + align:start position:0% +play that actually drives things to +being 0 looking at it this way imagine + + align:start position:0% +being 0 looking at it this way imagine + + + align:start position:0% +being 0 looking at it this way imagine +you have a universe that at early 10th + + align:start position:0% +you have a universe that at early 10th + + + align:start position:0% +you have a universe that at early 10th +at early times is very close to being + + align:start position:0% +at early times is very close to being + + + align:start position:0% +at early times is very close to being +flat but not quite any slight deviation + + align:start position:0% +flat but not quite any slight deviation + + + align:start position:0% +flat but not quite any slight deviation +from flatness + + align:start position:0% + + + + align:start position:0% + +grows as the universe expands that's + + align:start position:0% +grows as the universe expands that's + + + align:start position:0% +grows as the universe expands that's +mystery one mystery - why is the Cosmic + + align:start position:0% +mystery one mystery - why is the Cosmic + + + align:start position:0% +mystery one mystery - why is the Cosmic +Microwave Background so homogeneous so + + align:start position:0% +Microwave Background so homogeneous so + + + align:start position:0% +Microwave Background so homogeneous so +when we look at the Cosmic Microwave + + align:start position:0% +when we look at the Cosmic Microwave + + + align:start position:0% +when we look at the Cosmic Microwave +Background we see that it has the same + + align:start position:0% +Background we see that it has the same + + + align:start position:0% +Background we see that it has the same +properties the light has the same + + align:start position:0% +properties the light has the same + + + align:start position:0% +properties the light has the same +brightness it has the same temperature + + align:start position:0% +brightness it has the same temperature + + + align:start position:0% +brightness it has the same temperature +associated with it - it's in a part in a + + align:start position:0% +associated with it - it's in a part in a + + + align:start position:0% +associated with it - it's in a part in a +hundred thousand now the standard model + + align:start position:0% +hundred thousand now the standard model + + + align:start position:0% +hundred thousand now the standard model +of our universe tells us that at very + + align:start position:0% +of our universe tells us that at very + + + align:start position:0% +of our universe tells us that at very +early times the universe was essentially + + align:start position:0% +early times the universe was essentially + + + align:start position:0% +early times the universe was essentially +a dense hot plasma this thing cooled as + + align:start position:0% +a dense hot plasma this thing cooled as + + + align:start position:0% +a dense hot plasma this thing cooled as +the universe expanded much the same way + + align:start position:0% +the universe expanded much the same way + + + align:start position:0% +the universe expanded much the same way +that if you have a bag of gas you + + align:start position:0% +that if you have a bag of gas you + + + align:start position:0% +that if you have a bag of gas you +squeeze it very rapidly it will get hot + + align:start position:0% +squeeze it very rapidly it will get hot + + + align:start position:0% +squeeze it very rapidly it will get hot +you stretch it very rapidly it will cool + + align:start position:0% + + + + align:start position:0% + +so when we as a few more details of this + + align:start position:0% +so when we as a few more details of this + + + align:start position:0% +so when we as a few more details of this +in my notes but when we look at this one + + align:start position:0% +in my notes but when we look at this one + + + align:start position:0% +in my notes but when we look at this one +of the things that we see is that in a + + align:start position:0% +of the things that we see is that in a + + + align:start position:0% +of the things that we see is that in a +universe that is only only driven by + + align:start position:0% +universe that is only only driven by + + + align:start position:0% +universe that is only only driven by +matter or by radiation + + align:start position:0% + + + + align:start position:0% + +so sort of the matter-dominated and + + align:start position:0% +so sort of the matter-dominated and + + + align:start position:0% +so sort of the matter-dominated and +radiation dominated picture it shows us + + align:start position:0% +radiation dominated picture it shows us + + + align:start position:0% +radiation dominated picture it shows us +that points on opposite sides of the sky + + align:start position:0% + + + + align:start position:0% + +we're actually out of causal contact + + align:start position:0% +we're actually out of causal contact + + + align:start position:0% +we're actually out of causal contact +with each other in the earliest moments + + align:start position:0% +with each other in the earliest moments + + + align:start position:0% +with each other in the earliest moments +of the universe in other words I look at + + align:start position:0% +of the universe in other words I look at + + + align:start position:0% +of the universe in other words I look at +the sky and the patch of sky over here + + align:start position:0% +the sky and the patch of sky over here + + + align:start position:0% +the sky and the patch of sky over here +was out of causal contact with a patch + + align:start position:0% +was out of causal contact with a patch + + + align:start position:0% +was out of causal contact with a patch +of sky over here in the earliest days of + + align:start position:0% +of sky over here in the earliest days of + + + align:start position:0% +of sky over here in the earliest days of +the universe + + align:start position:0% +the universe + + + align:start position:0% +the universe +and yet they had the same temperature + + align:start position:0% +and yet they had the same temperature + + + align:start position:0% +and yet they had the same temperature +which suggests that they were in thermal + + align:start position:0% +which suggests that they were in thermal + + + align:start position:0% +which suggests that they were in thermal +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +how can two disparate unconnected patch + + align:start position:0% +how can two disparate unconnected patch + + + align:start position:0% +how can two disparate unconnected patch +of the sky have the same temperature if + + align:start position:0% +of the sky have the same temperature if + + + align:start position:0% +of the sky have the same temperature if +they cannot exchange information okay + + align:start position:0% +they cannot exchange information okay + + + align:start position:0% +they cannot exchange information okay +you can imagine it being a coincidence + + align:start position:0% +you can imagine it being a coincidence + + + align:start position:0% +you can imagine it being a coincidence +if one little bit of the sky has the + + align:start position:0% +if one little bit of the sky has the + + + align:start position:0% +if one little bit of the sky has the +same temperature as a bit on the other + + align:start position:0% +same temperature as a bit on the other + + + align:start position:0% +same temperature as a bit on the other +bit of another piece but in fact when + + align:start position:0% +bit of another piece but in fact when + + + align:start position:0% +bit of another piece but in fact when +you do this calculation you find huge + + align:start position:0% +you do this calculation you find huge + + + align:start position:0% +you do this calculation you find huge +patch of the sky could not communicate + + align:start position:0% +patch of the sky could not communicate + + + align:start position:0% +patch of the sky could not communicate +with any other um and so how then is it + + align:start position:0% +with any other um and so how then is it + + + align:start position:0% +with any other um and so how then is it +that the entire sky that we can observe + + align:start position:0% +that the entire sky that we can observe + + + align:start position:0% +that the entire sky that we can observe +has the same temperature at the earliest + + align:start position:0% +has the same temperature at the earliest + + + align:start position:0% +has the same temperature at the earliest +times to within a part in a hundred + + align:start position:0% +times to within a part in a hundred + + + align:start position:0% +times to within a part in a hundred +thousand you guys will explore this on I + + align:start position:0% +thousand you guys will explore this on I + + + align:start position:0% +thousand you guys will explore this on I +believe it's problem set eight the + + align:start position:0% +believe it's problem set eight the + + + align:start position:0% +believe it's problem set eight the +solution to both of these problems that + + align:start position:0% +solution to both of these problems that + + + align:start position:0% +solution to both of these problems that +has been proposed + + align:start position:0% + + + + align:start position:0% + +it's cosmic inflation so what you do is + + align:start position:0% +it's cosmic inflation so what you do is + + + align:start position:0% +it's cosmic inflation so what you do is +imagine that at some earlier moment in + + align:start position:0% +imagine that at some earlier moment in + + + align:start position:0% +imagine that at some earlier moment in +the universe our universe was filled + + align:start position:0% +the universe our universe was filled + + + align:start position:0% +the universe our universe was filled +with some strange field and I'll + + align:start position:0% +with some strange field and I'll + + + align:start position:0% +with some strange field and I'll +describe the properties of that field in + + align:start position:0% +describe the properties of that field in + + + align:start position:0% +describe the properties of that field in +just a moment such that it acted like it + + align:start position:0% +just a moment such that it acted like it + + + align:start position:0% +just a moment such that it acted like it +had a cosmological constant in such an + + align:start position:0% +had a cosmological constant in such an + + + align:start position:0% +had a cosmological constant in such an +epic the scale factor of the universe + + align:start position:0% +epic the scale factor of the universe + + + align:start position:0% +epic the scale factor of the universe +goes as exponentially with the square + + align:start position:0% +goes as exponentially with the square + + + align:start position:0% +goes as exponentially with the square +root of the sides of the cosmological + + align:start position:0% +root of the sides of the cosmological + + + align:start position:0% +root of the sides of the cosmological +constant what you find when you look at + + align:start position:0% +constant what you find when you look at + + + align:start position:0% +constant what you find when you look at +this is that this it's still of course + + align:start position:0% +this is that this it's still of course + + + align:start position:0% +this is that this it's still of course +goes there's a to the minus two but a to + + align:start position:0% +goes there's a to the minus two but a to + + + align:start position:0% +goes there's a to the minus two but a to +the minus will so sorry way back up for + + align:start position:0% +the minus will so sorry way back up for + + + align:start position:0% +the minus will so sorry way back up for +a second so my scale factor in this case + + align:start position:0% +a second so my scale factor in this case + + + align:start position:0% +a second so my scale factor in this case +you'll find goes as a to the minus two + + align:start position:0% + + + + align:start position:0% + +and that's because the density + + align:start position:0% +and that's because the density + + + align:start position:0% +and that's because the density +associated cosmological constant remains + + align:start position:0% +associated cosmological constant remains + + + align:start position:0% +associated cosmological constant remains +constant + + align:start position:0% + + + + align:start position:0% + +so even if you start in the early + + align:start position:0% +so even if you start in the early + + + align:start position:0% +so even if you start in the early +universe with some random value for the + + align:start position:0% +universe with some random value for the + + + align:start position:0% +universe with some random value for the +curvature if you are in this epoch of + + align:start position:0% +curvature if you are in this epoch of + + + align:start position:0% +curvature if you are in this epoch of +exponential inflation just for you know + + align:start position:0% +exponential inflation just for you know + + + align:start position:0% +exponential inflation just for you know +you have to worry about timescales a + + align:start position:0% +you have to worry about timescales a + + + align:start position:0% +you have to worry about timescales a +little bit but if you do it long enough + + align:start position:0% +little bit but if you do it long enough + + + align:start position:0% +little bit but if you do it long enough +you can drive this very very close to + + align:start position:0% +you can drive this very very close to + + + align:start position:0% +you can drive this very very close to +zero so much so that when you then move + + align:start position:0% +zero so much so that when you then move + + + align:start position:0% +zero so much so that when you then move +forward let's say you come out of this + + align:start position:0% +forward let's say you come out of this + + + align:start position:0% +forward let's say you come out of this +period of cosmic inflation and you enter + + align:start position:0% +period of cosmic inflation and you enter + + + align:start position:0% +period of cosmic inflation and you enter +a universe that is radiation dominated + + align:start position:0% +a universe that is radiation dominated + + + align:start position:0% +a universe that is radiation dominated +or matter-dominated it will then begin + + align:start position:0% +or matter-dominated it will then begin + + + align:start position:0% +or matter-dominated it will then begin +to grow but if you drive it sufficiently + + align:start position:0% +to grow but if you drive it sufficiently + + + align:start position:0% +to grow but if you drive it sufficiently +close to zero doesn't matter you're + + align:start position:0% +close to zero doesn't matter you're + + + align:start position:0% +close to zero doesn't matter you're +never going to catch up with what + + align:start position:0% +never going to catch up with what + + + align:start position:0% +never going to catch up with what +inflation did to you on the piece that + + align:start position:0% +inflation did to you on the piece that + + + align:start position:0% +inflation did to you on the piece that +you will also show that if you have a + + align:start position:0% +you will also show that if you have a + + + align:start position:0% +you will also show that if you have a +period of inflation like this then what + + align:start position:0% +period of inflation like this then what + + + align:start position:0% +period of inflation like this then what +that also cures the problem of peace of + + align:start position:0% +that also cures the problem of peace of + + + align:start position:0% +that also cures the problem of peace of +the sky being out of causal contact so + + align:start position:0% +the sky being out of causal contact so + + + align:start position:0% +the sky being out of causal contact so +when you do that what you find is that + + align:start position:0% +when you do that what you find is that + + + align:start position:0% +when you do that what you find is that +essentially everything is in causal + + align:start position:0% +essentially everything is in causal + + + align:start position:0% +essentially everything is in causal +contact early on it may sort of come out + + align:start position:0% +contact early on it may sort of come out + + + align:start position:0% +contact early on it may sort of come out +of causal contact after inflation has + + align:start position:0% +of causal contact after inflation has + + + align:start position:0% +of causal contact after inflation has +ended more on that in just a moment and + + align:start position:0% +ended more on that in just a moment and + + + align:start position:0% +ended more on that in just a moment and +then you know things sort of changed as + + align:start position:0% +then you know things sort of changed as + + + align:start position:0% +then you know things sort of changed as +the universe can use to evolve okay so + + align:start position:0% +the universe can use to evolve okay so + + + align:start position:0% +the universe can use to evolve okay so +it looks like recording is back on my + + align:start position:0% +it looks like recording is back on my + + + align:start position:0% +it looks like recording is back on my +apologies everyone so as I was in the + + align:start position:0% +apologies everyone so as I was in the + + + align:start position:0% +apologies everyone so as I was in the +middle of talk I talked a little bit too + + align:start position:0% +middle of talk I talked a little bit too + + + align:start position:0% +middle of talk I talked a little bit too +long in this this particular lecture so + + align:start position:0% +long in this this particular lecture so + + + align:start position:0% +long in this this particular lecture so +we're gonna spill over into a little bit + + align:start position:0% +we're gonna spill over into a little bit + + + align:start position:0% +we're gonna spill over into a little bit +of an addendum just a five ish minute + + align:start position:0% +of an addendum just a five ish minute + + + align:start position:0% +of an addendum just a five ish minute +piece that goes a bit beyond this doing + + align:start position:0% +piece that goes a bit beyond this doing + + + align:start position:0% +piece that goes a bit beyond this doing +this by myself is a little bit weird I'm + + align:start position:0% +this by myself is a little bit weird I'm + + + align:start position:0% +this by myself is a little bit weird I'm +tired and I will confess I got a little + + align:start position:0% +tired and I will confess I got a little + + + align:start position:0% +tired and I will confess I got a little +bit rattled when the police came in to + + align:start position:0% +bit rattled when the police came in to + + + align:start position:0% +bit rattled when the police came in to +check in on me let's back up for a + + align:start position:0% +check in on me let's back up for a + + + align:start position:0% +check in on me let's back up for a +second so I was talking about two + + align:start position:0% +second so I was talking about two + + + align:start position:0% +second so I was talking about two +mysteries of the modern cosmological + + align:start position:0% +mysteries of the modern cosmological + + + align:start position:0% +mysteries of the modern cosmological +model one of them is this question of + + align:start position:0% +model one of them is this question of + + + align:start position:0% +model one of them is this question of +why the universe is so apparently flat + + align:start position:0% +why the universe is so apparently flat + + + align:start position:0% +why the universe is so apparently flat +the spatial sector the universe appears + + align:start position:0% +the spatial sector the universe appears + + + align:start position:0% +the spatial sector the universe appears +to be flat and we have this expectation + + align:start position:0% +to be flat and we have this expectation + + + align:start position:0% +to be flat and we have this expectation +that the universe is either radiation + + align:start position:0% +that the universe is either radiation + + + align:start position:0% +that the universe is either radiation +dominated or matter dominated + + align:start position:0% +dominated or matter dominated + + + align:start position:0% +dominated or matter dominated +which would give us that the density + + align:start position:0% +which would give us that the density + + + align:start position:0% +which would give us that the density +associated with radiation if it's + + align:start position:0% +associated with radiation if it's + + + align:start position:0% +associated with radiation if it's +radiation dominated then the density of + + align:start position:0% +radiation dominated then the density of + + + align:start position:0% +radiation dominated then the density of +stuff in our universe would fall off + + align:start position:0% +stuff in our universe would fall off + + + align:start position:0% +stuff in our universe would fall off +there's the scale factor to the fourth + + align:start position:0% +there's the scale factor to the fourth + + + align:start position:0% +there's the scale factor to the fourth +power if it's matter dominant it's scale + + align:start position:0% +power if it's matter dominant it's scale + + + align:start position:0% +power if it's matter dominant it's scale +factor to the third power when you + + align:start position:0% +factor to the third power when you + + + align:start position:0% +factor to the third power when you +define a density associate with the + + align:start position:0% +define a density associate with the + + + align:start position:0% +define a density associate with the +curvature it falls off as a scale factor + + align:start position:0% +curvature it falls off as a scale factor + + + align:start position:0% +curvature it falls off as a scale factor +to the second power and so if we look at + + align:start position:0% +to the second power and so if we look at + + + align:start position:0% +to the second power and so if we look at +the ratio of the curvature density to + + align:start position:0% +the ratio of the curvature density to + + + align:start position:0% +the ratio of the curvature density to +any other kind of density it grows as + + align:start position:0% +any other kind of density it grows as + + + align:start position:0% +any other kind of density it grows as +the universe expands so any slight + + align:start position:0% +the universe expands so any slight + + + align:start position:0% +the universe expands so any slight +deviation from flatness we would expect + + align:start position:0% +deviation from flatness we would expect + + + align:start position:0% +deviation from flatness we would expect +to grow okay and that's just confusing + + align:start position:0% +to grow okay and that's just confusing + + + align:start position:0% +to grow okay and that's just confusing +why is it when we make the various + + align:start position:0% +why is it when we make the various + + + align:start position:0% +why is it when we make the various +measurements that we have been making + + align:start position:0% +measurements that we have been making + + + align:start position:0% +measurements that we have been making +for the past several decades all the + + align:start position:0% +for the past several decades all the + + + align:start position:0% +for the past several decades all the +evidence is pointing to a universe that + + align:start position:0% +evidence is pointing to a universe that + + + align:start position:0% +evidence is pointing to a universe that +has a flatness of zero okay but any + + align:start position:0% +has a flatness of zero okay but any + + + align:start position:0% +has a flatness of zero okay but any +slave if you sort of imagined that the + + align:start position:0% +slave if you sort of imagined that the + + + align:start position:0% +slave if you sort of imagined that the +parameter Kappa can be any number + + align:start position:0% +parameter Kappa can be any number + + + align:start position:0% +parameter Kappa can be any number +between minus infinity to infinity + + align:start position:0% +between minus infinity to infinity + + + align:start position:0% +between minus infinity to infinity +why is nature picking out zero another + + align:start position:0% +why is nature picking out zero another + + + align:start position:0% +why is nature picking out zero another +mystery is why is the Cosmic Microwave + + align:start position:0% +mystery is why is the Cosmic Microwave + + + align:start position:0% +mystery is why is the Cosmic Microwave +Background so Huma homogeneous we + + align:start position:0% +Background so Huma homogeneous we + + + align:start position:0% +Background so Huma homogeneous we +believed that the universe was a very + + align:start position:0% +believed that the universe was a very + + + align:start position:0% +believed that the universe was a very +hot dense plasma at very early times it + + align:start position:0% +hot dense plasma at very early times it + + + align:start position:0% +hot dense plasma at very early times it +cooled as the universe expanded and when + + align:start position:0% +cooled as the universe expanded and when + + + align:start position:0% +cooled as the universe expanded and when +we we measure the radiation from that + + align:start position:0% +we we measure the radiation from that + + + align:start position:0% +we we measure the radiation from that +that cooling expanding ball of clouds no + + align:start position:0% +that cooling expanding ball of clouds no + + + align:start position:0% +that cooling expanding ball of clouds no +what we find is that it has the same + + align:start position:0% +what we find is that it has the same + + + align:start position:0% +what we find is that it has the same +temperature at every point on the sky to + + align:start position:0% +temperature at every point on the sky to + + + align:start position:0% +temperature at every point on the sky to +within a part in a hundred thousand but + + align:start position:0% +within a part in a hundred thousand but + + + align:start position:0% +within a part in a hundred thousand but +when one looks at the behavior of of how + + align:start position:0% +when one looks at the behavior of of how + + + align:start position:0% +when one looks at the behavior of of how +how light moves around in the early + + align:start position:0% +how light moves around in the early + + + align:start position:0% +how light moves around in the early +universe if the universe is mad or + + align:start position:0% +universe if the universe is mad or + + + align:start position:0% +universe if the universe is mad or +dominated or radiation dominated what + + align:start position:0% +dominated or radiation dominated what + + + align:start position:0% +dominated or radiation dominated what +you find is that a piece of the sky over + + align:start position:0% +you find is that a piece of the sky over + + + align:start position:0% +you find is that a piece of the sky over +here cannot communicate with a piece of + + align:start position:0% +here cannot communicate with a piece of + + + align:start position:0% +here cannot communicate with a piece of +sky over here we're over here over here + + align:start position:0% +sky over here we're over here over here + + + align:start position:0% +sky over here we're over here over here +you actually find that the size of the + + align:start position:0% +you actually find that the size of the + + + align:start position:0% +you actually find that the size of the +sky that came that if I look at a piece + + align:start position:0% +sky that came that if I look at a piece + + + align:start position:0% +sky that came that if I look at a piece +of sky over here how much the universe + + align:start position:0% +of sky over here how much the universe + + + align:start position:0% +of sky over here how much the universe +could have talked to it's surprisingly + + align:start position:0% +could have talked to it's surprisingly + + + align:start position:0% +could have talked to it's surprisingly +small so how is it that the entire + + align:start position:0% +small so how is it that the entire + + + align:start position:0% +small so how is it that the entire +universe has the same temperature how is + + align:start position:0% +universe has the same temperature how is + + + align:start position:0% +universe has the same temperature how is +that they are apparently in thermal + + align:start position:0% +that they are apparently in thermal + + + align:start position:0% +that they are apparently in thermal +equilibrium even if they cannot exchange + + align:start position:0% +equilibrium even if they cannot exchange + + + align:start position:0% +equilibrium even if they cannot exchange +information so I spend some while + + align:start position:0% +information so I spend some while + + + align:start position:0% +information so I spend some while +talking to myself after the cameras went + + align:start position:0% +talking to myself after the cameras went + + + align:start position:0% +talking to myself after the cameras went +out + + align:start position:0% +out + + + align:start position:0% +out +so I just sketch what I wrote down a + + align:start position:0% +so I just sketch what I wrote down a + + + align:start position:0% +so I just sketch what I wrote down a +proposed solution to this to both of + + align:start position:0% +proposed solution to this to both of + + + align:start position:0% +proposed solution to this to both of +these mysteries is when it's known as + + align:start position:0% +these mysteries is when it's known as + + + align:start position:0% +these mysteries is when it's known as +cosmic inflation something that our own + + align:start position:0% +cosmic inflation something that our own + + + align:start position:0% +cosmic inflation something that our own +Alan Guth shares a lot of the credit for + + align:start position:0% +Alan Guth shares a lot of the credit for + + + align:start position:0% +Alan Guth shares a lot of the credit for +helping to develop so recall if we have + + align:start position:0% +helping to develop so recall if we have + + + align:start position:0% +helping to develop so recall if we have +a cosmological constant then the scale + + align:start position:0% +a cosmological constant then the scale + + + align:start position:0% +a cosmological constant then the scale +factor grows exponentially and the + + align:start position:0% +factor grows exponentially and the + + + align:start position:0% +factor grows exponentially and the +density of stuff associate that + + align:start position:0% +density of stuff associate that + + + align:start position:0% +density of stuff associate that +cosmological constant is constant okay + + align:start position:0% +cosmological constant is constant okay + + + align:start position:0% +cosmological constant is constant okay +as the universe expands the density the + + align:start position:0% +as the universe expands the density the + + + align:start position:0% +as the universe expands the density the +energy density associated that + + align:start position:0% +energy density associated that + + + align:start position:0% +energy density associated that +cosmological constant does not change if + + align:start position:0% +cosmological constant does not change if + + + align:start position:0% +cosmological constant does not change if +our universe is dominated by such a + + align:start position:0% +our universe is dominated by such a + + + align:start position:0% +our universe is dominated by such a +constant then the ratio of density is + + align:start position:0% +constant then the ratio of density is + + + align:start position:0% +constant then the ratio of density is +associate with curvature the densities + + align:start position:0% +associate with curvature the densities + + + align:start position:0% +associate with curvature the densities +associated cosmological constant + + align:start position:0% +associated cosmological constant + + + align:start position:0% +associated cosmological constant +actually falls off inversely with the + + align:start position:0% +actually falls off inversely with the + + + align:start position:0% +actually falls off inversely with the +curvature scale squared and the + + align:start position:0% +curvature scale squared and the + + + align:start position:0% +curvature scale squared and the +curvature scale is growing exponentially + + align:start position:0% +curvature scale is growing exponentially + + + align:start position:0% +curvature scale is growing exponentially +it means that Omega C is being driven to + + align:start position:0% +it means that Omega C is being driven to + + + align:start position:0% +it means that Omega C is being driven to +zero relative to the density in + + align:start position:0% +zero relative to the density in + + + align:start position:0% +zero relative to the density in +cosmological constant as e to the e to a + + align:start position:0% +cosmological constant as e to the e to a + + + align:start position:0% +cosmological constant as e to the e to a +factor like this it's being + + align:start position:0% +factor like this it's being + + + align:start position:0% +factor like this it's being +exponentially driven close to zero to do + + align:start position:0% +exponentially driven close to zero to do + + + align:start position:0% +exponentially driven close to zero to do +a little bit of work to figure out what + + align:start position:0% +a little bit of work to figure out what + + + align:start position:0% +a little bit of work to figure out what +the timescales associate this are but + + align:start position:0% +the timescales associate this are but + + + align:start position:0% +the timescales associate this are but +this sort of suggests that if you can + + align:start position:0% +this sort of suggests that if you can + + + align:start position:0% +this sort of suggests that if you can +put the universe in a state where it + + align:start position:0% +put the universe in a state where it + + + align:start position:0% +put the universe in a state where it +looks like a cause much more constant + + align:start position:0% +looks like a cause much more constant + + + align:start position:0% +looks like a cause much more constant +you can drive the density associate with + + align:start position:0% +you can drive the density associate with + + + align:start position:0% +you can drive the density associate with +curvature as close to zero as you want + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +recall that a cosmological constant is + + align:start position:0% +recall that a cosmological constant is + + + align:start position:0% +recall that a cosmological constant is +actually equivalent to there being a + + align:start position:0% +actually equivalent to there being a + + + align:start position:0% +actually equivalent to there being a +vacuum energy if we think about the + + align:start position:0% +vacuum energy if we think about the + + + align:start position:0% +vacuum energy if we think about the +universe being filled with some kind of + + align:start position:0% +universe being filled with some kind of + + + align:start position:0% +universe being filled with some kind of +a scalar field at early times it can + + align:start position:0% +a scalar field at early times it can + + + align:start position:0% +a scalar field at early times it can +play the role of such a vacuum energy + + align:start position:0% +play the role of such a vacuum energy + + + align:start position:0% +play the role of such a vacuum energy +without going into the details one finds + + align:start position:0% +without going into the details one finds + + + align:start position:0% +without going into the details one finds +that in an expanding universe there is + + align:start position:0% +that in an expanding universe there is + + + align:start position:0% +that in an expanding universe there is +an equation of motion for that scalar + + align:start position:0% +an equation of motion for that scalar + + + align:start position:0% +an equation of motion for that scalar +field how the field itself behaves as + + align:start position:0% +field how the field itself behaves as + + + align:start position:0% +field how the field itself behaves as +driven by a differential equation looks + + align:start position:0% +driven by a differential equation looks + + + align:start position:0% +driven by a differential equation looks +like this here's your Hubble parameter + + align:start position:0% +like this here's your Hubble parameter + + + align:start position:0% +like this here's your Hubble parameter +so this has to do with the scale factor + + align:start position:0% +so this has to do with the scale factor + + + align:start position:0% +so this has to do with the scale factor +in here V is a potential for this scalar + + align:start position:0% +in here V is a potential for this scalar + + + align:start position:0% +in here V is a potential for this scalar +field which I'm not going to say too + + align:start position:0% +field which I'm not going to say too + + + align:start position:0% +field which I'm not going to say too +much about take this guy couple it to + + align:start position:0% +much about take this guy couple it to + + + align:start position:0% +much about take this guy couple it to +your Fremont equations and the one + + align:start position:0% +your Fremont equations and the one + + + align:start position:0% +your Fremont equations and the one +that's most important is the first + + align:start position:0% +that's most important is the first + + + align:start position:0% +that's most important is the first +Freeman equation what you see is that V + + align:start position:0% +Freeman equation what you see is that V + + + align:start position:0% +Freeman equation what you see is that V +of Phi is playing the role of a of a + + align:start position:0% +of Phi is playing the role of a of a + + + align:start position:0% +of Phi is playing the role of a of a +cosmological constants playing the role + + align:start position:0% +cosmological constants playing the role + + + align:start position:0% +cosmological constants playing the role +of a density so if we can put the + + align:start position:0% +of a density so if we can put the + + + align:start position:0% +of a density so if we can put the +universe + + align:start position:0% +universe + + + align:start position:0% +universe +into a state where it is in fact being + + align:start position:0% +into a state where it is in fact being + + + align:start position:0% +into a state where it is in fact being +dominated by this scalar field by the + + align:start position:0% +dominated by this scalar field by the + + + align:start position:0% +dominated by this scalar field by the +potential associate with the scalar + + align:start position:0% +potential associate with the scalar + + + align:start position:0% +potential associate with the scalar +field it will inflate okay a lot of the + + align:start position:0% +field it will inflate okay a lot of the + + + align:start position:0% +field it will inflate okay a lot of the +research in early universe physics that + + align:start position:0% +research in early universe physics that + + + align:start position:0% +research in early universe physics that +was going on over the past couple + + align:start position:0% +was going on over the past couple + + + align:start position:0% +was going on over the past couple +decades has gone into understanding what + + align:start position:0% +decades has gone into understanding what + + + align:start position:0% +decades has gone into understanding what +are the consequences of such a such a + + align:start position:0% +are the consequences of such a such a + + + align:start position:0% +are the consequences of such a such a +potential can we make such a potential + + align:start position:0% +potential can we make such a potential + + + align:start position:0% +potential can we make such a potential +do the laws of physics ferment something + + align:start position:0% +do the laws of physics ferment something + + + align:start position:0% +do the laws of physics ferment something +like this to exist if the universe is in + + align:start position:0% +like this to exist if the universe is in + + + align:start position:0% +like this to exist if the universe is in +this state early on what changed how is + + align:start position:0% +this state early on what changed how is + + + align:start position:0% +this state early on what changed how is +it that this thing evolves there's an + + align:start position:0% +it that this thing evolves there's an + + + align:start position:0% +it that this thing evolves there's an +equation of motion here so this scalar + + align:start position:0% +equation of motion here so this scalar + + + align:start position:0% +equation of motion here so this scalar +field is presumably evolving in some + + align:start position:0% +field is presumably evolving in some + + + align:start position:0% +field is presumably evolving in some +kind of a way is there a potential is + + align:start position:0% +kind of a way is there a potential is + + + align:start position:0% +kind of a way is there a potential is +this nature permit us to have a field of + + align:start position:0% +this nature permit us to have a field of + + + align:start position:0% +this nature permit us to have a field of +the sort with a potential that sort of + + align:start position:0% +the sort with a potential that sort of + + + align:start position:0% +the sort with a potential that sort of +goes away after some time once it goes + + align:start position:0% +goes away after some time once it goes + + + align:start position:0% +goes away after some time once it goes +away what happens to that field is there + + align:start position:0% +away what happens to that field is there + + + align:start position:0% +away what happens to that field is there +any smoking gun associate as this you + + align:start position:0% +any smoking gun associate as this you + + + align:start position:0% +any smoking gun associate as this you +know we look at the universe and this is + + align:start position:0% +know we look at the universe and this is + + + align:start position:0% +know we look at the universe and this is +a plausible explanation for why the + + align:start position:0% +a plausible explanation for why the + + + align:start position:0% +a plausible explanation for why the +universe appears to be spatially flat + + align:start position:0% +universe appears to be spatially flat + + + align:start position:0% +universe appears to be spatially flat +and why the Cosmic Microwave Background + + align:start position:0% +and why the Cosmic Microwave Background + + + align:start position:0% +and why the Cosmic Microwave Background +is so humid genius is there anything + + align:start position:0% +is so humid genius is there anything + + + align:start position:0% +is so humid genius is there anything +else that we can look at that would + + align:start position:0% +else that we can look at that would + + + align:start position:0% +else that we can look at that would +basically say yes the universe did in + + align:start position:0% +basically say yes the universe did in + + + align:start position:0% +basically say yes the universe did in +fact have this kind of an expansion + + align:start position:0% +fact have this kind of an expansion + + + align:start position:0% +fact have this kind of an expansion +without getting into the weeds too much + + align:start position:0% +without getting into the weeds too much + + + align:start position:0% +without getting into the weeds too much +it turns out that if the universe + + align:start position:0% +it turns out that if the universe + + + align:start position:0% +it turns out that if the universe +expanded like this we would expect there + + align:start position:0% +expanded like this we would expect there + + + align:start position:0% +expanded like this we would expect there +to be a primordial background of + + align:start position:0% +to be a primordial background of + + + align:start position:0% +to be a primordial background of +gravitational waves very low-frequency + + align:start position:0% +gravitational waves very low-frequency + + + align:start position:0% +gravitational waves very low-frequency +gravitational waves sort of a moaning + + align:start position:0% +gravitational waves sort of a moaning + + + align:start position:0% +gravitational waves sort of a moaning +background filling the universe and so + + align:start position:0% +background filling the universe and so + + + align:start position:0% +background filling the universe and so +there's a lot of experiments looking for + + align:start position:0% +there's a lot of experiments looking for + + + align:start position:0% +there's a lot of experiments looking for +the imprints of such gravitational waves + + align:start position:0% +the imprints of such gravitational waves + + + align:start position:0% +the imprints of such gravitational waves +on our universe if it is measured it + + align:start position:0% +on our universe if it is measured it + + + align:start position:0% +on our universe if it is measured it +would allow us to directly probe what + + align:start position:0% +would allow us to directly probe what + + + align:start position:0% +would allow us to directly probe what +this inflationary potential actually is + + align:start position:0% +this inflationary potential actually is + + + align:start position:0% +this inflationary potential actually is +I'm going to conclude our discussion of + + align:start position:0% +I'm going to conclude our discussion of + + + align:start position:0% +I'm going to conclude our discussion of +cosmology here so some of these some of + + align:start position:0% +cosmology here so some of these some of + + + align:start position:0% +cosmology here so some of these some of +the quantitative details the way in + + align:start position:0% +the quantitative details the way in + + + align:start position:0% +the quantitative details the way in +which inflation can cure the flatness + + align:start position:0% +which inflation can cure the flatness + + + align:start position:0% +which inflation can cure the flatness +problem and cure the homogeneity problem + + align:start position:0% +problem and cure the homogeneity problem + + + align:start position:0% +problem and cure the homogeneity problem +you'll explore on problem set seven + + align:start position:0% +you'll explore on problem set seven + + + align:start position:0% +you'll explore on problem set seven +going into the weeds of how one makes + + align:start position:0% +going into the weeds of how one makes + + + align:start position:0% +going into the weeds of how one makes +with the scalar field designs of + + align:start position:0% +with the scalar field designs of + + + align:start position:0% +with the scalar field designs of +potential and does things like this + + align:start position:0% +potential and does things like this + + + align:start position:0% +potential and does things like this +beyond the scope of eight 962 there are + + align:start position:0% +beyond the scope of eight 962 there are + + + align:start position:0% +beyond the scope of eight 962 there are +courses like this and I would not be + + align:start position:0% +courses like this and I would not be + + + align:start position:0% +courses like this and I would not be +surprised if some of the people in this + + align:start position:0% +surprised if some of the people in this + + + align:start position:0% +surprised if some of the people in this +class spend a lot more time studying + + align:start position:0% +class spend a lot more time studying + + + align:start position:0% +class spend a lot more time studying +this in their futures than I have in my + + align:start position:0% +this in their futures than I have in my + + + align:start position:0% +this in their futures than I have in my +life all right so that is where we will + + align:start position:0% +life all right so that is where we will + + + align:start position:0% +life all right so that is where we will +conclude our discussion of cosmology \ No newline at end of file diff --git a/plrrHK_cNtM.txt b/plrrHK_cNtM.txt new file mode 100644 index 0000000000000000000000000000000000000000..f38644cde94c9852a464d0a647b2182e2605d63e --- /dev/null +++ b/plrrHK_cNtM.txt @@ -0,0 +1,595 @@ +align:start position:0% + +the fields of a circular cylindrical + + align:start position:0% +the fields of a circular cylindrical + + + align:start position:0% +the fields of a circular cylindrical +solenoid can be found using the + + align:start position:0% +solenoid can be found using the + + + align:start position:0% +solenoid can be found using the +biot-savart law if these plain parallel + + align:start position:0% +biot-savart law if these plain parallel + + + align:start position:0% +biot-savart law if these plain parallel +plates were of infinite extent an + + align:start position:0% +plates were of infinite extent an + + + align:start position:0% +plates were of infinite extent an +applied voltage would give an electric + + align:start position:0% +applied voltage would give an electric + + + align:start position:0% +applied voltage would give an electric +field that is uniform what this plane + + align:start position:0% +field that is uniform what this plane + + + align:start position:0% +field that is uniform what this plane +parallel capacitor is two electric + + align:start position:0% +parallel capacitor is two electric + + + align:start position:0% +parallel capacitor is two electric +fields and infinitely long solenoid is + + align:start position:0% +fields and infinitely long solenoid is + + + align:start position:0% +fields and infinitely long solenoid is +to magnetic fields that is if this + + align:start position:0% +to magnetic fields that is if this + + + align:start position:0% +to magnetic fields that is if this +solenoid were infinitely long a current + + align:start position:0% +solenoid were infinitely long a current + + + align:start position:0% +solenoid were infinitely long a current +in the winding would produce a magnetic + + align:start position:0% +in the winding would produce a magnetic + + + align:start position:0% +in the winding would produce a magnetic +field intensity that is essentially + + align:start position:0% +field intensity that is essentially + + + align:start position:0% +field intensity that is essentially +uniform inside and equal to the surface + + align:start position:0% +uniform inside and equal to the surface + + + align:start position:0% +uniform inside and equal to the surface +current density outside the field would + + align:start position:0% +current density outside the field would + + + align:start position:0% +current density outside the field would +be essentially zero this solenoid is + + align:start position:0% +be essentially zero this solenoid is + + + align:start position:0% +be essentially zero this solenoid is +large enough that we can poke around in + + align:start position:0% +large enough that we can poke around in + + + align:start position:0% +large enough that we can poke around in +it with a magnetometer probe and see how + + align:start position:0% +it with a magnetometer probe and see how + + + align:start position:0% +it with a magnetometer probe and see how +the magnetic field is actually + + align:start position:0% +the magnetic field is actually + + + align:start position:0% +the magnetic field is actually +distributed when the length is finite + + align:start position:0% + + + + align:start position:0% + +this axial whole probe shows us the + + align:start position:0% +this axial whole probe shows us the + + + align:start position:0% +this axial whole probe shows us the +magnitude and direction of the field the + + align:start position:0% +magnitude and direction of the field the + + + align:start position:0% +magnitude and direction of the field the +probe measures the field along its axis + + align:start position:0% +probe measures the field along its axis + + + align:start position:0% +probe measures the field along its axis +the lower scope trace records the pro + + align:start position:0% +the lower scope trace records the pro + + + align:start position:0% +the lower scope trace records the pro +back put the upper scope trace shows the + + align:start position:0% +back put the upper scope trace shows the + + + align:start position:0% +back put the upper scope trace shows the +coil current when the probe is oriented + + align:start position:0% +coil current when the probe is oriented + + + align:start position:0% +coil current when the probe is oriented +this way the axial component of magnetic + + align:start position:0% +this way the axial component of magnetic + + + align:start position:0% +this way the axial component of magnetic +field is measured when the probe is + + align:start position:0% +field is measured when the probe is + + + align:start position:0% +field is measured when the probe is +oriented this way the radial component + + align:start position:0% +oriented this way the radial component + + + align:start position:0% +oriented this way the radial component +of magnetic field is measured let's + + align:start position:0% +of magnetic field is measured let's + + + align:start position:0% +of magnetic field is measured let's +measure the axial magnetic field + + align:start position:0% +measure the axial magnetic field + + + align:start position:0% +measure the axial magnetic field +component along the axis of the cylinder + + align:start position:0% + + + + align:start position:0% + +on the axis the radial component is of + + align:start position:0% +on the axis the radial component is of + + + align:start position:0% +on the axis the radial component is of +course zero because of symmetry well + + align:start position:0% +course zero because of symmetry well + + + align:start position:0% +course zero because of symmetry well +inside the solenoid the field intensity + + align:start position:0% +inside the solenoid the field intensity + + + align:start position:0% +inside the solenoid the field intensity +in the Z Direction tends to be uniform + + align:start position:0% +in the Z Direction tends to be uniform + + + align:start position:0% +in the Z Direction tends to be uniform +everywhere + + align:start position:0% + + + + align:start position:0% + +the infinitely long solenoid can be + + align:start position:0% +the infinitely long solenoid can be + + + align:start position:0% +the infinitely long solenoid can be +regarded as the analog for mqs systems + + align:start position:0% +regarded as the analog for mqs systems + + + align:start position:0% +regarded as the analog for mqs systems +of the eqs plane parallel plate + + align:start position:0% +of the eqs plane parallel plate + + + align:start position:0% +of the eqs plane parallel plate +capacitor let's measure the magnetic + + align:start position:0% +capacitor let's measure the magnetic + + + align:start position:0% +capacitor let's measure the magnetic +field well inside the solenoid we + + align:start position:0% +field well inside the solenoid we + + + align:start position:0% +field well inside the solenoid we +measure about 2.3 gals just inside the + + align:start position:0% +measure about 2.3 gals just inside the + + + align:start position:0% +measure about 2.3 gals just inside the +winding as compared to the prediction of + + align:start position:0% +winding as compared to the prediction of + + + align:start position:0% +winding as compared to the prediction of +two and a half Gauss let's see what the + + align:start position:0% +two and a half Gauss let's see what the + + + align:start position:0% +two and a half Gauss let's see what the +tangential flux density is just outside + + align:start position:0% +tangential flux density is just outside + + + align:start position:0% +tangential flux density is just outside +at the same axial location just outside + + align:start position:0% +at the same axial location just outside + + + align:start position:0% +at the same axial location just outside +the flux density forwards by more than a + + align:start position:0% +the flux density forwards by more than a + + + align:start position:0% +the flux density forwards by more than a +factor of 10 to 0.15 Gauss just as the + + align:start position:0% +factor of 10 to 0.15 Gauss just as the + + + align:start position:0% +factor of 10 to 0.15 Gauss just as the +capacitor can be constructed to create a + + align:start position:0% +capacitor can be constructed to create a + + + align:start position:0% +capacitor can be constructed to create a +uniform electric field between the + + align:start position:0% +uniform electric field between the + + + align:start position:0% +uniform electric field between the +plates with zero field outside the + + align:start position:0% +plates with zero field outside the + + + align:start position:0% +plates with zero field outside the +region bounded by the plates so to you + + align:start position:0% +region bounded by the plates so to you + + + align:start position:0% +region bounded by the plates so to you +the long solenoid gives rise to a + + align:start position:0% +the long solenoid gives rise to a + + + align:start position:0% +the long solenoid gives rise to a +uniform magnetic field throughout the + + align:start position:0% +uniform magnetic field throughout the + + + align:start position:0% +uniform magnetic field throughout the +interior region all solenoid length is + + align:start position:0% +interior region all solenoid length is + + + align:start position:0% +interior region all solenoid length is +finite so the field inside is only + + align:start position:0% +finite so the field inside is only + + + align:start position:0% +finite so the field inside is only +approximately uniform + + align:start position:0% + + + + align:start position:0% + +and the exterior field is only + + align:start position:0% +and the exterior field is only + + + align:start position:0% +and the exterior field is only +approximately zero + + align:start position:0% + + + + align:start position:0% + +another way to demonstrate the + + align:start position:0% +another way to demonstrate the + + + align:start position:0% +another way to demonstrate the +discontinuity in magnetic field between + + align:start position:0% +discontinuity in magnetic field between + + + align:start position:0% +discontinuity in magnetic field between +inside and outside the solenoid is to + + align:start position:0% +inside and outside the solenoid is to + + + align:start position:0% +inside and outside the solenoid is to +use this transverse probe this probe + + align:start position:0% +use this transverse probe this probe + + + align:start position:0% +use this transverse probe this probe +measures magnetic fields transverse to + + align:start position:0% +measures magnetic fields transverse to + + + align:start position:0% +measures magnetic fields transverse to +its flat surface here for example is the + + align:start position:0% +its flat surface here for example is the + + + align:start position:0% +its flat surface here for example is the +on-axis field turning the probe by 90 + + align:start position:0% +on-axis field turning the probe by 90 + + + align:start position:0% +on-axis field turning the probe by 90 +degrees gives a zero signal which shows + + align:start position:0% +degrees gives a zero signal which shows + + + align:start position:0% +degrees gives a zero signal which shows +the field is purely axial we now place + + align:start position:0% +the field is purely axial we now place + + + align:start position:0% +the field is purely axial we now place +this probe just outside the solenoid in + + align:start position:0% +this probe just outside the solenoid in + + + align:start position:0% +this probe just outside the solenoid in +the orientation to measure the small + + align:start position:0% +the orientation to measure the small + + + align:start position:0% +the orientation to measure the small +tangential field component as the probe + + align:start position:0% +tangential field component as the probe + + + align:start position:0% +tangential field component as the probe +passes through the current carrying + + align:start position:0% +passes through the current carrying + + + align:start position:0% +passes through the current carrying +winding the magnetic field abruptly + + align:start position:0% +winding the magnetic field abruptly + + + align:start position:0% +winding the magnetic field abruptly +rises to the interior field value + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/pmI0Bl3ozWU.txt b/pmI0Bl3ozWU.txt new file mode 100644 index 0000000000000000000000000000000000000000..7e764a3a52b02611e767d62def4d0027ca9d2359 --- /dev/null +++ b/pmI0Bl3ozWU.txt @@ -0,0 +1,27 @@ +align:start position:0% + +[Music] + + align:start position:0% + + + + align:start position:0% + +um + + align:start position:0% +um + + + align:start position:0% +um +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +you \ No newline at end of file diff --git a/pqFskmxJZCo.txt b/pqFskmxJZCo.txt new file mode 100644 index 0000000000000000000000000000000000000000..6c390e41b52af6b14f1656c90789d0b1dbdc4679 --- /dev/null +++ b/pqFskmxJZCo.txt @@ -0,0 +1,1995 @@ +align:start position:0% + +just informal + + align:start position:0% +just informal + + + align:start position:0% +just informal +if you want to be a little bit more + + align:start position:0% +if you want to be a little bit more + + + align:start position:0% +if you want to be a little bit more +formal you can say + + align:start position:0% +formal you can say + + + align:start position:0% +formal you can say +what well we're not going to bed yet + + align:start position:0% +what well we're not going to bed yet + + + align:start position:0% +what well we're not going to bed yet +you're saying you're going to die + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +today is an important day in italy + + align:start position:0% +today is an important day in italy + + + align:start position:0% +today is an important day in italy +because it's the beginning + + align:start position:0% +because it's the beginning + + + align:start position:0% +because it's the beginning +of carne vale + + align:start position:0% +of carne vale + + + align:start position:0% +of carne vale +carnevales is carnival i think you are + + align:start position:0% +carnevales is carnival i think you are + + + align:start position:0% +carnevales is carnival i think you are +familiar + + align:start position:0% +familiar + + + align:start position:0% +familiar +originally italy the celebration of + + align:start position:0% +originally italy the celebration of + + + align:start position:0% +originally italy the celebration of +carnival was the celebration + + align:start position:0% +carnival was the celebration + + + align:start position:0% +carnival was the celebration +of the end of the winter and the + + align:start position:0% +of the end of the winter and the + + + align:start position:0% +of the end of the winter and the +beginning of the spring + + align:start position:0% +beginning of the spring + + + align:start position:0% +beginning of the spring +it should be much later here in boston + + align:start position:0% +it should be much later here in boston + + + align:start position:0% +it should be much later here in boston +it's not usually february + + align:start position:0% +it's not usually february + + + align:start position:0% +it's not usually february +in italy usually middle of february is a + + align:start position:0% +in italy usually middle of february is a + + + align:start position:0% +in italy usually middle of february is a +good time when it starts to get warmer + + align:start position:0% +good time when it starts to get warmer + + + align:start position:0% +good time when it starts to get warmer +and + + align:start position:0% +and + + + align:start position:0% +and +it's not spring but it's the beginning + + align:start position:0% +it's not spring but it's the beginning + + + align:start position:0% +it's not spring but it's the beginning +so carne vale is carnival + + align:start position:0% +so carne vale is carnival + + + align:start position:0% +so carne vale is carnival +it starts today and it will end on + + align:start position:0% +it starts today and it will end on + + + align:start position:0% +it starts today and it will end on +tuesday + + align:start position:0% +tuesday + + + align:start position:0% +tuesday +next tuesday tuesday is + + align:start position:0% +next tuesday tuesday is + + + align:start position:0% +next tuesday tuesday is +martini today and we call + + align:start position:0% +martini today and we call + + + align:start position:0% +martini today and we call +this specific tuesday + + align:start position:0% + + + + align:start position:0% + +means fats + + align:start position:0% + + + + align:start position:0% + +yeah it's fat tuesday so why is fat + + align:start position:0% +yeah it's fat tuesday so why is fat + + + align:start position:0% +yeah it's fat tuesday so why is fat +tuesday + + align:start position:0% +tuesday + + + align:start position:0% +tuesday +well because typically we would eat very + + align:start position:0% +well because typically we would eat very + + + align:start position:0% +well because typically we would eat very +very fat + + align:start position:0% +very fat + + + align:start position:0% +very fat +food and you have some examples + + align:start position:0% +food and you have some examples + + + align:start position:0% +food and you have some examples +here these are some typical sweets that + + align:start position:0% +here these are some typical sweets that + + + align:start position:0% +here these are some typical sweets that +we eat for carnevale + + align:start position:0% + + + + align:start position:0% + +they're both deep fried so we're not + + align:start position:0% +they're both deep fried so we're not + + + align:start position:0% +they're both deep fried so we're not +going to do them they're not + + align:start position:0% +going to do them they're not + + + align:start position:0% +going to do them they're not +particularly healthy + + align:start position:0% +particularly healthy + + + align:start position:0% +particularly healthy +but if you want the recipe i need you + + align:start position:0% +but if you want the recipe i need you + + + align:start position:0% +but if you want the recipe i need you +the recipe anyway + + align:start position:0% +the recipe anyway + + + align:start position:0% +the recipe anyway +they're very very tasty the idea is that + + align:start position:0% +they're very very tasty the idea is that + + + align:start position:0% +they're very very tasty the idea is that +this celebration was initially a pagan + + align:start position:0% +this celebration was initially a pagan + + + align:start position:0% +this celebration was initially a pagan +celebration + + align:start position:0% +celebration + + + align:start position:0% +celebration +and then it became a christian + + align:start position:0% +and then it became a christian + + + align:start position:0% +and then it became a christian +celebration + + align:start position:0% +celebration + + + align:start position:0% +celebration +like a huge party where everything + + align:start position:0% +like a huge party where everything + + + align:start position:0% +like a huge party where everything +or almost everything is allowed + + align:start position:0% +or almost everything is allowed + + + align:start position:0% +or almost everything is allowed +before the beginning of juarez + + align:start position:0% +before the beginning of juarez + + + align:start position:0% +before the beginning of juarez +had lent that is a period where + + align:start position:0% +had lent that is a period where + + + align:start position:0% +had lent that is a period where +period more of any turns a period where + + align:start position:0% +period more of any turns a period where + + + align:start position:0% +period more of any turns a period where +many + + align:start position:0% +many + + + align:start position:0% +many +many people decide for example to let go + + align:start position:0% +many people decide for example to let go + + + align:start position:0% +many people decide for example to let go +of some luxuries of some things they + + align:start position:0% +of some luxuries of some things they + + + align:start position:0% +of some luxuries of some things they +like + + align:start position:0% +like + + + align:start position:0% +like +so it's like the last huge party you can + + align:start position:0% +so it's like the last huge party you can + + + align:start position:0% +so it's like the last huge party you can +eat everything in fact and afterwards + + align:start position:0% +eat everything in fact and afterwards + + + align:start position:0% +eat everything in fact and afterwards +maybe you decide oh + + align:start position:0% +maybe you decide oh + + + align:start position:0% +maybe you decide oh +i'm gonna diet i'm not going to eat + + align:start position:0% +i'm gonna diet i'm not going to eat + + + align:start position:0% +i'm gonna diet i'm not going to eat +anything so for carnivale + + align:start position:0% +anything so for carnivale + + + align:start position:0% +anything so for carnivale +carnival people usually wear costumes + + align:start position:0% +carnival people usually wear costumes + + + align:start position:0% +carnival people usually wear costumes +kind of like halloween here and mostly + + align:start position:0% +kind of like halloween here and mostly + + + align:start position:0% +kind of like halloween here and mostly +kids + + align:start position:0% +kids + + + align:start position:0% +kids +like it's very unusual that you walk + + align:start position:0% +like it's very unusual that you walk + + + align:start position:0% +like it's very unusual that you walk +anywhere in italy and you find everybody + + align:start position:0% +anywhere in italy and you find everybody + + + align:start position:0% +anywhere in italy and you find everybody +in costume + + align:start position:0% +in costume + + + align:start position:0% +in costume +but well there are like kids especially + + align:start position:0% +but well there are like kids especially + + + align:start position:0% +but well there are like kids especially +and there are some parties and + + align:start position:0% + + + + align:start position:0% + +there are some i'm sorry for the quality + + align:start position:0% +there are some i'm sorry for the quality + + + align:start position:0% +there are some i'm sorry for the quality +but you have a printout actually of the + + align:start position:0% +but you have a printout actually of the + + + align:start position:0% +but you have a printout actually of the +macbook + + align:start position:0% +macbook + + + align:start position:0% +macbook +and there are some huge huge + + align:start position:0% +and there are some huge huge + + + align:start position:0% +and there are some huge huge +celebrations + + align:start position:0% +celebrations + + + align:start position:0% +celebrations +the most famous are the carnivale of + + align:start position:0% +the most famous are the carnivale of + + + align:start position:0% +the most famous are the carnivale of +diarrhea girl is in tuscany + + align:start position:0% +diarrhea girl is in tuscany + + + align:start position:0% +diarrhea girl is in tuscany +there is carnevale ibrea + + align:start position:0% +there is carnevale ibrea + + + align:start position:0% +there is carnevale ibrea +ibrea is in + + align:start position:0% + + + + align:start position:0% + +and for the carnivale of the apart from + + align:start position:0% +and for the carnivale of the apart from + + + align:start position:0% +and for the carnivale of the apart from +wearing costumes there is also a very + + align:start position:0% +wearing costumes there is also a very + + + align:start position:0% +wearing costumes there is also a very +famous + + align:start position:0% +famous + + + align:start position:0% +famous +bottle with oranges people throw + + align:start position:0% +bottle with oranges people throw + + + align:start position:0% +bottle with oranges people throw +oranges if you google it you see the + + align:start position:0% +oranges if you google it you see the + + + align:start position:0% +oranges if you google it you see the +images is really really + + align:start position:0% +images is really really + + + align:start position:0% +images is really really +something and then probably the most + + align:start position:0% +something and then probably the most + + + align:start position:0% +something and then probably the most +famous carnival + + align:start position:0% +famous carnival + + + align:start position:0% +famous carnival +in italy is incarnate venezia + + align:start position:0% +in italy is incarnate venezia + + + align:start position:0% +in italy is incarnate venezia +venice there it is + + align:start position:0% +venice there it is + + + align:start position:0% +venice there it is +so in venezuela + + align:start position:0% + + + + align:start position:0% + +there are a lot of parades and there are + + align:start position:0% +there are a lot of parades and there are + + + align:start position:0% +there are a lot of parades and there are +some + + align:start position:0% +some + + + align:start position:0% +some +characteristic costumes traditional + + align:start position:0% +characteristic costumes traditional + + + align:start position:0% +characteristic costumes traditional +costumes so you should enjoy carnevale + + align:start position:0% +costumes so you should enjoy carnevale + + + align:start position:0% +costumes so you should enjoy carnevale +during the weekend you have a long + + align:start position:0% +during the weekend you have a long + + + align:start position:0% +during the weekend you have a long +weekend for a different reason + + align:start position:0% +weekend for a different reason + + + align:start position:0% +weekend for a different reason +but okay enjoy nevada until + + align:start position:0% +but okay enjoy nevada until + + + align:start position:0% +but okay enjoy nevada until +tuesday until because afterwards + + align:start position:0% +tuesday until because afterwards + + + align:start position:0% +tuesday until because afterwards +we can't celebrate anymore so let's try + + align:start position:0% +we can't celebrate anymore so let's try + + + align:start position:0% +we can't celebrate anymore so let's try +to + + align:start position:0% +to + + + align:start position:0% +to +review what you did the idea is this + + align:start position:0% +review what you did the idea is this + + + align:start position:0% +review what you did the idea is this +each of you can stand up + + align:start position:0% +each of you can stand up + + + align:start position:0% +each of you can stand up +look at the others and say ciao + + align:start position:0% +look at the others and say ciao + + + align:start position:0% +look at the others and say ciao +you say your name and then just + + align:start position:0% +you say your name and then just + + + align:start position:0% +you say your name and then just +tell us something that you remember from + + align:start position:0% +tell us something that you remember from + + + align:start position:0% +tell us something that you remember from +last week + + align:start position:0% +last week + + + align:start position:0% +last week +it can be anything that could it can be + + align:start position:0% +it can be anything that could it can be + + + align:start position:0% +it can be anything that could it can be +another sentence + + align:start position:0% +another sentence + + + align:start position:0% +another sentence +it could be even just the way that you + + align:start position:0% +it could be even just the way that you + + + align:start position:0% +it could be even just the way that you +pronounce the letter a + + align:start position:0% +pronounce the letter a + + + align:start position:0% +pronounce the letter a +that's uh okay you can come here and say + + align:start position:0% +that's uh okay you can come here and say + + + align:start position:0% +that's uh okay you can come here and say +hey ciao + + align:start position:0% + + + + align:start position:0% + +we say oh + + align:start position:0% +we say oh + + + align:start position:0% +we say oh +the vowels + + align:start position:0% + + + + align:start position:0% + +ciao michael mcclara + + align:start position:0% + + + + align:start position:0% + +uh + + align:start position:0% + + + + align:start position:0% + +our second lesson and + + align:start position:0% +our second lesson and + + + align:start position:0% +our second lesson and +i can ask each of you + + align:start position:0% + + + + align:start position:0% + +let's do it one word at a time you + + align:start position:0% +let's do it one word at a time you + + + align:start position:0% +let's do it one word at a time you +remember + + align:start position:0% +remember + + + align:start position:0% +remember +omit the subject too because it's not + + align:start position:0% +omit the subject too because it's not + + + align:start position:0% +omit the subject too because it's not +that important + + align:start position:0% +that important + + + align:start position:0% +that important +unless i really want to emphasize then i + + align:start position:0% +unless i really want to emphasize then i + + + align:start position:0% +unless i really want to emphasize then i +would i would say so i start from here + + align:start position:0% + + + + align:start position:0% + +let's do another round we can ask + + align:start position:0% +let's do another round we can ask + + + align:start position:0% +let's do another round we can ask +each other where do we come from and you + + align:start position:0% +each other where do we come from and you + + + align:start position:0% +each other where do we come from and you +can say i come from + + align:start position:0% +can say i come from + + + align:start position:0% +can say i come from +wherever you come from i said milano i'm + + align:start position:0% +wherever you come from i said milano i'm + + + align:start position:0% +wherever you come from i said milano i'm +not exactly from + + align:start position:0% +not exactly from + + + align:start position:0% +not exactly from +milan i'm from a small town close to + + align:start position:0% +milan i'm from a small town close to + + + align:start position:0% +milan i'm from a small town close to +milan + + align:start position:0% +milan + + + align:start position:0% +milan +on big lake that's the largest lake in + + align:start position:0% +on big lake that's the largest lake in + + + align:start position:0% +on big lake that's the largest lake in +italy + + align:start position:0% +italy + + + align:start position:0% +italy +named lake + + align:start position:0% + + + + align:start position:0% + +lagos + + align:start position:0% + + + + align:start position:0% + +but i think that most of you come from + + align:start position:0% +but i think that most of you come from + + + align:start position:0% +but i think that most of you come from +this unity + + align:start position:0% + + + + align:start position:0% + +let's say + + align:start position:0% + + + + align:start position:0% + +that would + + align:start position:0% + + + + align:start position:0% + +if you have a feminine it could be + + align:start position:0% + + + + align:start position:0% + +so texas is not a city + + align:start position:0% +so texas is not a city + + + align:start position:0% +so texas is not a city +it's a state so you put the article and + + align:start position:0% +it's a state so you put the article and + + + align:start position:0% +it's a state so you put the article and +you say + + align:start position:0% +you say + + + align:start position:0% +you say +vengo dal texas + + align:start position:0% + + + + align:start position:0% + +texas + + align:start position:0% +texas + + + align:start position:0% +texas +yeah so now you know how to introduce + + align:start position:0% +yeah so now you know how to introduce + + + align:start position:0% +yeah so now you know how to introduce +yourself + + align:start position:0% +yourself + + + align:start position:0% +yourself +how to say where you come from + + align:start position:0% + + + + align:start position:0% + +let me look around + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% + + + + align:start position:0% + +yeah so we are trying to learn + + align:start position:0% +yeah so we are trying to learn + + + align:start position:0% +yeah so we are trying to learn +demonstrative objectives so in english + + align:start position:0% +demonstrative objectives so in english + + + align:start position:0% +demonstrative objectives so in english +you have this that these + + align:start position:0% +you have this that these + + + align:start position:0% +you have this that these +those let's start with the singular + + align:start position:0% +those let's start with the singular + + + align:start position:0% +those let's start with the singular +in italian we have questo + + align:start position:0% + + + + align:start position:0% + +code + + align:start position:0% + + + + align:start position:0% + +okay you see they all end with an o so + + align:start position:0% +okay you see they all end with an o so + + + align:start position:0% +okay you see they all end with an o so +that's + + align:start position:0% +that's + + + align:start position:0% +that's +masculine how come that we have three + + align:start position:0% +masculine how come that we have three + + + align:start position:0% +masculine how come that we have three +choices + + align:start position:0% +choices + + + align:start position:0% +choices +instead of just two this and that well + + align:start position:0% +instead of just two this and that well + + + align:start position:0% +instead of just two this and that well +questo means this and it's something + + align:start position:0% +questo means this and it's something + + + align:start position:0% +questo means this and it's something +that is close to me + + align:start position:0% +that is close to me + + + align:start position:0% +that is close to me +when i'm talking about something that's + + align:start position:0% +when i'm talking about something that's + + + align:start position:0% +when i'm talking about something that's +close to me + + align:start position:0% + + + + align:start position:0% + +is something that is far from me but is + + align:start position:0% +is something that is far from me but is + + + align:start position:0% +is something that is far from me but is +close to you it's not really very common + + align:start position:0% +close to you it's not really very common + + + align:start position:0% +close to you it's not really very common +you won't hear it when you talk to the + + align:start position:0% +you won't hear it when you talk to the + + + align:start position:0% +you won't hear it when you talk to the +other + + align:start position:0% +other + + + align:start position:0% +other +italian unless he or he comes from + + align:start position:0% +italian unless he or he comes from + + + align:start position:0% +italian unless he or he comes from +tuscany + + align:start position:0% +tuscany + + + align:start position:0% +tuscany +then there is a chance that they will + + align:start position:0% +then there is a chance that they will + + + align:start position:0% +then there is a chance that they will +use podesta + + align:start position:0% +use podesta + + + align:start position:0% +use podesta +but from now on we will just stick to + + align:start position:0% +but from now on we will just stick to + + + align:start position:0% +but from now on we will just stick to +cuesto + + align:start position:0% + + + + align:start position:0% + +for that so in principle is when it's + + align:start position:0% +for that so in principle is when it's + + + align:start position:0% +for that so in principle is when it's +far from + + align:start position:0% +far from + + + align:start position:0% +far from +both of us so as i told you already last + + align:start position:0% +both of us so as i told you already last + + + align:start position:0% +both of us so as i told you already last +time + + align:start position:0% +time + + + align:start position:0% +time +in italian we conjugate everything so + + align:start position:0% +in italian we conjugate everything so + + + align:start position:0% +in italian we conjugate everything so +if an adjective refers to a noun that's + + align:start position:0% +if an adjective refers to a noun that's + + + align:start position:0% +if an adjective refers to a noun that's +feminine + + align:start position:0% +feminine + + + align:start position:0% +feminine +or masculine the ending changes + + align:start position:0% +or masculine the ending changes + + + align:start position:0% +or masculine the ending changes +so in english you would say + + align:start position:0% +so in english you would say + + + align:start position:0% +so in english you would say +this onion and + + align:start position:0% +this onion and + + + align:start position:0% +this onion and +this book + + align:start position:0% + + + + align:start position:0% + +in italian i would say questo + + align:start position:0% + + + + align:start position:0% + +foreign + + align:start position:0% + + + + align:start position:0% + +if it's masculine it becomes questi + + align:start position:0% + + + + align:start position:0% + +and if it's feminine it becomes quest + + align:start position:0% + + + + align:start position:0% + +question + + align:start position:0% + + + + align:start position:0% + +and now you can try to read without me + + align:start position:0% +and now you can try to read without me + + + align:start position:0% +and now you can try to read without me +what's going on + + align:start position:0% +what's going on + + + align:start position:0% +what's going on +with that and those + + align:start position:0% + + + + align:start position:0% + +so let's see what i told you earlier + + align:start position:0% +so let's see what i told you earlier + + + align:start position:0% +so let's see what i told you earlier +questa questions + + align:start position:0% + + + + align:start position:0% + +i forgot + + align:start position:0% + + + + align:start position:0% + +adjective similar + + align:start position:0% + + + + align:start position:0% + +okay + + align:start position:0% + + + + align:start position:0% + +is bigger + + align:start position:0% + + + + align:start position:0% + +d that would be + + align:start position:0% + + + + align:start position:0% + +then + + align:start position:0% + + + + align:start position:0% + +what + + align:start position:0% + + + + align:start position:0% + +itself + + align:start position:0% + + + + align:start position:0% + +since we want to go ahead and learn + + align:start position:0% +since we want to go ahead and learn + + + align:start position:0% +since we want to go ahead and learn +how to say la let's see + + align:start position:0% +how to say la let's see + + + align:start position:0% +how to say la let's see +exactly where this word come from sulla + + align:start position:0% +exactly where this word come from sulla + + + align:start position:0% +exactly where this word come from sulla +is a composition of + + align:start position:0% +is a composition of + + + align:start position:0% +is a composition of +soup that means on + + align:start position:0% +soup that means on + + + align:start position:0% +soup that means on +and + + align:start position:0% + + + + align:start position:0% + +that would be the article + + align:start position:0% + + + + align:start position:0% + +and then we just put them together and + + align:start position:0% +and then we just put them together and + + + align:start position:0% +and then we just put them together and +it becomes + + align:start position:0% +it becomes + + + align:start position:0% +it becomes +okay so take it some time and try you + + align:start position:0% +okay so take it some time and try you + + + align:start position:0% +okay so take it some time and try you +can discuss you can do this together + + align:start position:0% +can discuss you can do this together + + + align:start position:0% +can discuss you can do this together +try to come out with some new ten + + align:start position:0% +try to come out with some new ten + + + align:start position:0% +try to come out with some new ten +sentences involving + + align:start position:0% +sentences involving + + + align:start position:0% +sentences involving +the adjectivity and some of the words + + align:start position:0% +the adjectivity and some of the words + + + align:start position:0% +the adjectivity and some of the words +that you already know + + align:start position:0% + + + + align:start position:0% + +let me write it down + + align:start position:0% + + + + align:start position:0% + +people look at you like where do you + + align:start position:0% +people look at you like where do you + + + align:start position:0% +people look at you like where do you +come from + + align:start position:0% +come from + + + align:start position:0% +come from +united states + + align:start position:0% + + + + align:start position:0% + +we put an apostrophe that little sign is + + align:start position:0% +we put an apostrophe that little sign is + + + align:start position:0% +we put an apostrophe that little sign is +an apostrophe + + align:start position:0% + + + + align:start position:0% + +you can say questions + + align:start position:0% + + + + align:start position:0% + +so yeah one way to refer to apples and + + align:start position:0% +so yeah one way to refer to apples and + + + align:start position:0% +so yeah one way to refer to apples and +pears + + align:start position:0% +pears + + + align:start position:0% +pears +is to call them homie + + align:start position:0% + + + + align:start position:0% + +typically if you are talking about this + + align:start position:0% +typically if you are talking about this + + + align:start position:0% +typically if you are talking about this +fruit + + align:start position:0% +fruit + + + align:start position:0% +fruit +then you say you call it milan + + align:start position:0% + + + + align:start position:0% + +so this fruit is mela + + align:start position:0% + + + + align:start position:0% + +and i can say mela + + align:start position:0% + + + + align:start position:0% + +with me + + align:start position:0% +with me + + + align:start position:0% +with me +well i actually have two oh + + align:start position:0% +well i actually have two oh + + + align:start position:0% +well i actually have two oh +yeah so it was questa now i have two + + align:start position:0% + + + + align:start position:0% + +questions + + align:start position:0% + + + + align:start position:0% + +when we have only one cuesta + + align:start position:0% + + + + align:start position:0% + +who wants to write the nest + + align:start position:0% + + + + align:start position:0% + +very good + + align:start position:0% + + + + align:start position:0% + +so you see we don't add an s like in + + align:start position:0% +so you see we don't add an s like in + + + align:start position:0% +so you see we don't add an s like in +english to make the plural + + align:start position:0% +english to make the plural + + + align:start position:0% +english to make the plural +we change the ending of the word + + align:start position:0% + + + + align:start position:0% + +we also + + align:start position:0% + + + + align:start position:0% + +next time we will actually conjugate the + + align:start position:0% +next time we will actually conjugate the + + + align:start position:0% +next time we will actually conjugate the +whole verb to be + + align:start position:0% +whole verb to be + + + align:start position:0% +whole verb to be +in the present okay + + align:start position:0% + + + + align:start position:0% + +good + + align:start position:0% + + + + align:start position:0% + +so tonight we're going to cook a dish + + align:start position:0% +so tonight we're going to cook a dish + + + align:start position:0% +so tonight we're going to cook a dish +that's typical from northern italy + + align:start position:0% +that's typical from northern italy + + + align:start position:0% +that's typical from northern italy +it's called risotto + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/qdbkvD4N-us.txt b/qdbkvD4N-us.txt new file mode 100644 index 0000000000000000000000000000000000000000..2cdbaa274de926365b44c88f25c426726503b322 --- /dev/null +++ b/qdbkvD4N-us.txt @@ -0,0 +1,7992 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at + + align:start position:0% + + + + align:start position:0% + +ocw.mmit.edu. So far, we had a function + + align:start position:0% +ocw.mmit.edu. So far, we had a function + + + align:start position:0% +ocw.mmit.edu. So far, we had a function +and then we differentiated to get an + + align:start position:0% +and then we differentiated to get an + + + align:start position:0% +and then we differentiated to get an +equation of this type. But now we're + + align:start position:0% +equation of this type. But now we're + + + align:start position:0% +equation of this type. But now we're +given this equation and we want to go + + align:start position:0% +given this equation and we want to go + + + align:start position:0% +given this equation and we want to go +backwards. Want to find the stochastic + + align:start position:0% +backwards. Want to find the stochastic + + + align:start position:0% +backwards. Want to find the stochastic +process that satisfies this equation. So + + align:start position:0% +process that satisfies this equation. So + + + align:start position:0% +process that satisfies this equation. So +goal is to find a stochastic + + align:start position:0% + + + + align:start position:0% + +process XT satisfying this + + align:start position:0% + + + + align:start position:0% + +equation. Okay. In other words, we want + + align:start position:0% +equation. Okay. In other words, we want + + + align:start position:0% +equation. Okay. In other words, we want +x of t to be the integral of + + align:start position:0% + + + + align:start position:0% + +mu ds plus + + align:start position:0% +mu ds plus + + + align:start position:0% +mu ds plus +sigma d + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +s. The goal is clear. We want + + align:start position:0% + + + + align:start position:0% + +that. + + align:start position:0% +that. + + + align:start position:0% +that. +And so these type of equations are + + align:start position:0% +And so these type of equations are + + + align:start position:0% +And so these type of equations are +called differential equations. I hope + + align:start position:0% +called differential equations. I hope + + + align:start position:0% +called differential equations. I hope +you already know + + align:start position:0% +you already know + + + align:start position:0% +you already know +that also for PTE partial differential + + align:start position:0% +that also for PTE partial differential + + + align:start position:0% +that also for PTE partial differential +equations. So even when it's not + + align:start position:0% +equations. So even when it's not + + + align:start position:0% +equations. So even when it's not +stochastic these are not easy + + align:start position:0% +stochastic these are not easy + + + align:start position:0% +stochastic these are not easy +problems at least not easy in the sense + + align:start position:0% +problems at least not easy in the sense + + + align:start position:0% +problems at least not easy in the sense +that if you're given an equation + + align:start position:0% +that if you're given an equation + + + align:start position:0% +that if you're given an equation +typically you don't expect to have a + + align:start position:0% +typically you don't expect to have a + + + align:start position:0% +typically you don't expect to have a +closed form solution. So even if you + + align:start position:0% +closed form solution. So even if you + + + align:start position:0% +closed form solution. So even if you +find this x most of the times it's not + + align:start position:0% +find this x most of the times it's not + + + align:start position:0% +find this x most of the times it's not +in a very good form. + + align:start position:0% +in a very good form. + + + align:start position:0% +in a very good form. +Still a very important result that you + + align:start position:0% +Still a very important result that you + + + align:start position:0% +Still a very important result that you +should first know before trying to solve + + align:start position:0% +should first know before trying to solve + + + align:start position:0% +should first know before trying to solve +any of the differential equation is + + align:start position:0% +any of the differential equation is + + + align:start position:0% +any of the differential equation is +that as long as mu and sigma are + + align:start position:0% +that as long as mu and sigma are + + + align:start position:0% +that as long as mu and sigma are +reasonable functions there does exist a + + align:start position:0% +reasonable functions there does exist a + + + align:start position:0% +reasonable functions there does exist a +solution and it's + + align:start position:0% +solution and it's + + + align:start position:0% +solution and it's +unique. So we have the same + + align:start position:0% +unique. So we have the same + + + align:start position:0% +unique. So we have the same +correspondence with this PD. they're + + align:start position:0% +correspondence with this PD. they're + + + align:start position:0% +correspondence with this PD. they're +given a PD given a differential equation + + align:start position:0% +given a PD given a differential equation + + + align:start position:0% +given a PD given a differential equation +not a stoastic differential equation you + + align:start position:0% +not a stoastic differential equation you + + + align:start position:0% +not a stoastic differential equation you +know that if you're given a reasonable + + align:start position:0% +know that if you're given a reasonable + + + align:start position:0% +know that if you're given a reasonable +differential equation then you have a + + align:start position:0% +differential equation then you have a + + + align:start position:0% +differential equation then you have a +unique a solution exists and it's unique + + align:start position:0% +unique a solution exists and it's unique + + + align:start position:0% +unique a solution exists and it's unique +so the same principle holds in stoastic + + align:start position:0% +so the same principle holds in stoastic + + + align:start position:0% +so the same principle holds in stoastic +world let me state it + + align:start position:0% + + + + align:start position:0% + +formally this stoastic equation + + align:start position:0% +formally this stoastic equation + + + align:start position:0% +formally this stoastic equation +star + + align:start position:0% +star + + + align:start position:0% +star +has a solution + + align:start position:0% + + + + align:start position:0% + +uh that is + + align:start position:0% +uh that is + + + align:start position:0% +uh that is +unique. Okay. Uh, of course with + + align:start position:0% +unique. Okay. Uh, of course with + + + align:start position:0% +unique. Okay. Uh, of course with +boundary + + align:start position:0% +boundary + + + align:start position:0% +boundary +condition has a + + align:start position:0% +condition has a + + + align:start position:0% +condition has a +solution + + align:start position:0% +solution + + + align:start position:0% +solution +and given the initial points + + align:start position:0% + + + + align:start position:0% + +X. Oh yeah. So if you're given the + + align:start position:0% +X. Oh yeah. So if you're given the + + + align:start position:0% +X. Oh yeah. So if you're given the +initial point of the stoastic process, + + align:start position:0% +initial point of the stoastic process, + + + align:start position:0% +initial point of the stoastic process, +then the solution is + + align:start position:0% + + + + align:start position:0% + +unique. Just + + align:start position:0% +unique. Just + + + align:start position:0% +unique. Just +check. Yes. + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +As long + + align:start position:0% +As long + + + align:start position:0% +As long +as mu and sigma are + + align:start position:0% + + + + align:start position:0% + +reasonable. One way can be reasonable if + + align:start position:0% +reasonable. One way can be reasonable if + + + align:start position:0% +reasonable. One way can be reasonable if +it satisfies this conditions. + + align:start position:0% + + + + align:start position:0% + +So these are very technical conditions + + align:start position:0% +So these are very technical conditions + + + align:start position:0% +So these are very technical conditions +but at least let me parse to you what + + align:start position:0% +but at least let me parse to you what + + + align:start position:0% +but at least let me parse to you what +they are. They say if you fix a time + + align:start position:0% +they are. They say if you fix a time + + + align:start position:0% +they are. They say if you fix a time +coordinate and you change x, you look at + + align:start position:0% +coordinate and you change x, you look at + + + align:start position:0% +coordinate and you change x, you look at +the difference between the values of mu + + align:start position:0% +the difference between the values of mu + + + align:start position:0% +the difference between the values of mu +when you change the second variable and + + align:start position:0% +when you change the second variable and + + + align:start position:0% +when you change the second variable and +the + + align:start position:0% +the + + + align:start position:0% +the +sigma. Then the change in your function + + align:start position:0% +sigma. Then the change in your function + + + align:start position:0% +sigma. Then the change in your function +is bounded by the distance between the + + align:start position:0% +is bounded by the distance between the + + + align:start position:0% +is bounded by the distance between the +two points by some constant k. Okay. So + + align:start position:0% +two points by some constant k. Okay. So + + + align:start position:0% +two points by some constant k. Okay. So +mu and sigma cannot change too much when + + align:start position:0% +mu and sigma cannot change too much when + + + align:start position:0% +mu and sigma cannot change too much when +you change your space variable a little + + align:start position:0% +you change your space variable a little + + + align:start position:0% +you change your space variable a little +bit. It can only change up to the + + align:start position:0% +bit. It can only change up to the + + + align:start position:0% +bit. It can only change up to the +distance of how much you change the + + align:start position:0% +distance of how much you change the + + + align:start position:0% +distance of how much you change the +coordinate. So that's the first + + align:start position:0% +coordinate. So that's the first + + + align:start position:0% +coordinate. So that's the first +condition. Second condition + + align:start position:0% +condition. Second condition + + + align:start position:0% +condition. Second condition +says yeah when you grow your + + align:start position:0% +says yeah when you grow your + + + align:start position:0% +says yeah when you grow your +x it's very similar condition + + align:start position:0% +x it's very similar condition + + + align:start position:0% +x it's very similar condition +essentially says it cannot blow up too + + align:start position:0% +essentially says it cannot blow up too + + + align:start position:0% +essentially says it cannot blow up too +fast the whole thing. This one is + + align:start position:0% +fast the whole thing. This one is + + + align:start position:0% +fast the whole thing. This one is +something about the difference between + + align:start position:0% +something about the difference between + + + align:start position:0% +something about the difference between +two values. This one is about how it + + align:start position:0% +two values. This one is about how it + + + align:start position:0% +two values. This one is about how it +expands as your space variable + + align:start position:0% +expands as your space variable + + + align:start position:0% +expands as your space variable +grows. These are technical conditions + + align:start position:0% +grows. These are technical conditions + + + align:start position:0% +grows. These are technical conditions +and many + + align:start position:0% +and many + + + align:start position:0% +and many +cases + + align:start position:0% +cases + + + align:start position:0% +cases +just they will hold. Don't worry too + + align:start position:0% +just they will hold. Don't worry too + + + align:start position:0% +just they will hold. Don't worry too +much about the technical + + align:start position:0% +much about the technical + + + align:start position:0% +much about the technical +conditions. Important thing here is that + + align:start position:0% +conditions. Important thing here is that + + + align:start position:0% +conditions. Important thing here is that +given a given a differential equation + + align:start position:0% +given a given a differential equation + + + align:start position:0% +given a given a differential equation +you don't expect to have a good form + + align:start position:0% +you don't expect to have a good form + + + align:start position:0% +you don't expect to have a good form +closed form but you do expect to have a + + align:start position:0% +closed form but you do expect to have a + + + align:start position:0% +closed form but you do expect to have a +solution of some form. + + align:start position:0% + + + + align:start position:0% + +Okay. So, let's work out some + + align:start position:0% + + + + align:start position:0% + +examples. Here is one of the few + + align:start position:0% +examples. Here is one of the few + + + align:start position:0% +examples. Here is one of the few +different stoastic differential + + align:start position:0% +different stoastic differential + + + align:start position:0% +different stoastic differential +equations that can be + + align:start position:0% + + + + align:start position:0% + +solved. This one can be solved. and you + + align:start position:0% +solved. This one can be solved. and you + + + align:start position:0% +solved. This one can be solved. and you +already know what like what x + + align:start position:0% +already know what like what x + + + align:start position:0% +already know what like what x +is but let's pretend you don't know how + + align:start position:0% +is but let's pretend you don't know how + + + align:start position:0% +is but let's pretend you don't know how +to you don't know what x is and let's + + align:start position:0% +to you don't know what x is and let's + + + align:start position:0% +to you don't know what x is and let's +try to solve it this doesn't this + + align:start position:0% +try to solve it this doesn't this + + + align:start position:0% +try to solve it this doesn't this +approach I will show you an approach + + align:start position:0% +approach I will show you an approach + + + align:start position:0% +approach I will show you an approach +where which can solve some differential + + align:start position:0% +where which can solve some differential + + + align:start position:0% +where which can solve some differential +equations some some sdes but this really + + align:start position:0% +equations some some sdes but this really + + + align:start position:0% +equations some some sdes but this really +it won't happen that much still it's + + align:start position:0% +it won't happen that much still it's + + + align:start position:0% +it won't happen that much still it's +like a starting + + align:start position:0% +like a starting + + + align:start position:0% +like a starting +point okay there's that set that and + + align:start position:0% +point okay there's that set that and + + + align:start position:0% +point okay there's that set that and +assume x0 + + align:start position:0% + + + + align:start position:0% + +Z and mu sigma are + + align:start position:0% + + + + align:start position:0% + +constants. Just like when solving + + align:start position:0% +constants. Just like when solving + + + align:start position:0% +constants. Just like when solving +differential equations, first thing + + align:start position:0% +differential equations, first thing + + + align:start position:0% +differential equations, first thing +you'll do is just guess. Suppose guess + + align:start position:0% + + + + align:start position:0% + +If you want this to happen, + + align:start position:0% +If you want this to happen, + + + align:start position:0% +If you want this to happen, +then d of x of + + align:start position:0% +then d of x of + + + align:start position:0% +then d of x of +t + + align:start position:0% + + + + align:start position:0% + +is. Okay. + + align:start position:0% + + + + align:start position:0% + +X is just the second + + align:start position:0% +X is just the second + + + align:start position:0% +X is just the second +variable and then these two have to + + align:start position:0% +variable and then these two have to + + + align:start position:0% +variable and then these two have to +match. That has to be equal to that. + + align:start position:0% +match. That has to be equal to that. + + + align:start position:0% +match. That has to be equal to that. +That has to be equal to that. So we know + + align:start position:0% +That has to be equal to that. So we know + + + align:start position:0% +That has to be equal to that. So we know +that del F over D + + align:start position:0% +that del F over D + + + align:start position:0% +that del F over D +X + + align:start position:0% + + + + align:start position:0% + +T mu of X of + + align:start position:0% + + + + align:start position:0% + +T= mu of X. + + align:start position:0% + + + + align:start position:0% + +Okay, so we assume that this is a + + align:start position:0% +Okay, so we assume that this is a + + + align:start position:0% +Okay, so we assume that this is a +solution then differentiated that and + + align:start position:0% +solution then differentiated that and + + + align:start position:0% +solution then differentiated that and +then if that's a solution these all have + + align:start position:0% +then if that's a solution these all have + + + align:start position:0% +then if that's a solution these all have +to match. You get this equation. Now if + + align:start position:0% +to match. You get this equation. Now if + + + align:start position:0% +to match. You get this equation. Now if +you look at that that tells you that f + + align:start position:0% +you look at that that tells you that f + + + align:start position:0% +you look at that that tells you that f +is an exponential function in the x + + align:start position:0% +is an exponential function in the x + + + align:start position:0% +is an exponential function in the x +variable. So it's e to the sigma x * + + align:start position:0% +variable. So it's e to the sigma x * + + + align:start position:0% +variable. So it's e to the sigma x * +x and then we have a constant term plus + + align:start position:0% +x and then we have a constant term plus + + + align:start position:0% +x and then we have a constant term plus +some a times a function of + + align:start position:0% + + + + align:start position:0% + +t. The only way we can happen is if it's + + align:start position:0% +t. The only way we can happen is if it's + + + align:start position:0% +t. The only way we can happen is if it's +in this form. So it's exponential + + align:start position:0% +in this form. So it's exponential + + + align:start position:0% +in this form. So it's exponential +function in x and in the second uh in + + align:start position:0% +function in x and in the second uh in + + + align:start position:0% +function in x and in the second uh in +the time + + align:start position:0% +the time + + + align:start position:0% +the time +variable it's just some constant. when + + align:start position:0% +variable it's just some constant. when + + + align:start position:0% +variable it's just some constant. when +you fix a t it's a constant and when + + align:start position:0% +you fix a t it's a constant and when + + + align:start position:0% +you fix a t it's a constant and when +when you fix a t and change x it has to + + align:start position:0% +when you fix a t and change x it has to + + + align:start position:0% +when you fix a t and change x it has to +look like exponential function but it + + align:start position:0% +look like exponential function but it + + + align:start position:0% +look like exponential function but it +has to be in this form just by the + + align:start position:0% +has to be in this form just by the + + + align:start position:0% +has to be in this form just by the +second + + align:start position:0% +second + + + align:start position:0% +second +equation. Now go back to the this + + align:start position:0% +equation. Now go back to the this + + + align:start position:0% +equation. Now go back to the this +equation you get is partial f over + + align:start position:0% +equation you get is partial f over + + + align:start position:0% +equation you get is partial f over +partial t is + + align:start position:0% + + + + align:start position:0% + +now a * g prime of + + align:start position:0% +now a * g prime of + + + align:start position:0% +now a * g prime of +t. So + + align:start position:0% + + + + align:start position:0% + +f + + align:start position:0% + + + + align:start position:0% + +Excuse me. Mhm. U that one in second + + align:start position:0% +Excuse me. Mhm. U that one in second + + + align:start position:0% +Excuse me. Mhm. U that one in second +last line. Uh yeah. So why is it minus + + align:start position:0% +last line. Uh yeah. So why is it minus + + + align:start position:0% +last line. Uh yeah. So why is it minus +muf at the end? Are you + + align:start position:0% + + + + align:start position:0% + +okay? Okay. And then let's plug it in. + + align:start position:0% +okay? Okay. And then let's plug it in. + + + align:start position:0% +okay? Okay. And then let's plug it in. +So we have a of g prime t + + align:start position:0% +So we have a of g prime t + + + align:start position:0% +So we have a of g prime t +ff plus 12 of sigma square + + align:start position:0% + + + + align:start position:0% + +f. In other words, a of g prime of t is + + align:start position:0% +f. In other words, a of g prime of t is + + + align:start position:0% +f. In other words, a of g prime of t is +u + + align:start position:0% + + + + align:start position:0% + +-² + + align:start position:0% +-² + + + align:start position:0% +-² +gt is u + + align:start position:0% +gt is u + + + align:start position:0% +gt is u +* some constant c1 + + + align:start position:0% + + + + align:start position:0% + +c2. Okay. And then what we got is + + align:start position:0% +c2. Okay. And then what we got is + + + align:start position:0% +c2. Okay. And then what we got is +original function f of t of x is e to + + align:start position:0% +original function f of t of x is e to + + + align:start position:0% +original function f of t of x is e to +the sigma x + mu - 1 /2 sigma^ 2 t plus + + align:start position:0% +the sigma x + mu - 1 /2 sigma^ 2 t plus + + + align:start position:0% +the sigma x + mu - 1 /2 sigma^ 2 t plus +some + + align:start position:0% +some + + + align:start position:0% +some +constant and that + + align:start position:0% +constant and that + + + align:start position:0% +constant and that +constant can be chosen because we have + + align:start position:0% +constant can be chosen because we have + + + align:start position:0% +constant can be chosen because we have +the initial condition x of + + align:start position:0% + + + + align:start position:0% + +0 equals + + align:start position:0% +0 equals + + + align:start position:0% +0 equals +z. That means if t is equal to z, f0 of + + align:start position:0% +z. That means if t is equal to z, f0 of + + + align:start position:0% +z. That means if t is equal to z, f0 of +0 is equal to e to the c. That has to be + + align:start position:0% +0 is equal to e to the c. That has to be + + + align:start position:0% +0 is equal to e to the c. That has to be +x0. In different words, this is just x0 + + align:start position:0% +x0. In different words, this is just x0 + + + align:start position:0% +x0. In different words, this is just x0 +* e sigma x + mu - 4 sigma square t. + + align:start position:0% +* e sigma x + mu - 4 sigma square t. + + + align:start position:0% +* e sigma x + mu - 4 sigma square t. +Just as we expected, we got + + align:start position:0% + + + + align:start position:0% + +this. Okay. So, some stoastic difference + + align:start position:0% +this. Okay. So, some stoastic difference + + + align:start position:0% +this. Okay. So, some stoastic difference +different differential equations can be + + align:start position:0% +different differential equations can be + + + align:start position:0% +different differential equations can be +solved + + align:start position:0% +solved + + + align:start position:0% +solved +by analyzing it. But I'm not necessarily + + align:start position:0% +by analyzing it. But I'm not necessarily + + + align:start position:0% +by analyzing it. But I'm not necessarily +saying that this is a better way to do + + align:start position:0% +saying that this is a better way to do + + + align:start position:0% +saying that this is a better way to do +it than just guessing. Just looking at + + align:start position:0% +it than just guessing. Just looking at + + + align:start position:0% +it than just guessing. Just looking at +it and you know okay it has to be a + + align:start position:0% +it and you know okay it has to be a + + + align:start position:0% +it and you know okay it has to be a +different uh exponential function. You + + align:start position:0% +different uh exponential function. You + + + align:start position:0% +different uh exponential function. You +know what I'll just change figure out + + align:start position:0% +know what I'll just change figure out + + + align:start position:0% +know what I'll just change figure out +what these are and I will come up with + + align:start position:0% +what these are and I will come up with + + + align:start position:0% +what these are and I will come up with +this formula without going through all + + align:start position:0% +this formula without going through all + + + align:start position:0% +this formula without going through all +those + + align:start position:0% +those + + + align:start position:0% +those +analysis. I'm not saying that's the + + align:start position:0% +analysis. I'm not saying that's the + + + align:start position:0% +analysis. I'm not saying that's the +worst way than actually going through + + align:start position:0% +worst way than actually going through + + + align:start position:0% +worst way than actually going through +the analysis because in fact what we did + + align:start position:0% +the analysis because in fact what we did + + + align:start position:0% +the analysis because in fact what we did +is we kind of already knew the answer + + align:start position:0% +is we kind of already knew the answer + + + align:start position:0% +is we kind of already knew the answer +was fit and was and are fitting into + + align:start position:0% +was fit and was and are fitting into + + + align:start position:0% +was fit and was and are fitting into +that answer right now. + + align:start position:0% + + + + align:start position:0% + +Still, it can be one approach where you + + align:start position:0% +Still, it can be one approach where you + + + align:start position:0% +Still, it can be one approach where you +don't have a reasonable guess of what + + align:start position:0% +don't have a reasonable guess of what + + + align:start position:0% +don't have a reasonable guess of what +the xt has to be. Maybe try to break it + + align:start position:0% +the xt has to be. Maybe try to break it + + + align:start position:0% +the xt has to be. Maybe try to break it +down into pieces like this and backtrack + + align:start position:0% +down into pieces like this and backtrack + + + align:start position:0% +down into pieces like this and backtrack +to figure out the function. Let me give + + align:start position:0% +to figure out the function. Let me give + + + align:start position:0% +to figure out the function. Let me give +you one more example where we do have an + + align:start position:0% +you one more example where we do have an + + + align:start position:0% +you one more example where we do have an +explicit solution and then I'll move on + + align:start position:0% +explicit solution and then I'll move on + + + align:start position:0% +explicit solution and then I'll move on +and to and show you how to do when there + + align:start position:0% +and to and show you how to do when there + + + align:start position:0% +and to and show you how to do when there +is no explicit solution or when you + + align:start position:0% +is no explicit solution or when you + + + align:start position:0% +is no explicit solution or when you +don't know how to find an explicit + + align:start position:0% +don't know how to find an explicit + + + align:start position:0% +don't know how to find an explicit +solution. + + align:start position:0% + + + + align:start position:0% + +Maybe let's keep that + + align:start position:0% + + + + align:start position:0% + +there. + + align:start position:0% + + + + align:start position:0% + +Okay, second equation. Let's call + + align:start position:0% + + + + align:start position:0% + +this. What's the difference? The only + + align:start position:0% +this. What's the difference? The only + + + align:start position:0% +this. What's the difference? The only +difference is that you don't have an x + + align:start position:0% +difference is that you don't have an x + + + align:start position:0% +difference is that you don't have an x +here. + + align:start position:0% +here. + + + align:start position:0% +here. +So + + align:start position:0% +So + + + align:start position:0% +So +previously our main drift term also was + + align:start position:0% +previously our main drift term also was + + + align:start position:0% +previously our main drift term also was +proportional to the current value and + + align:start position:0% +proportional to the current value and + + + align:start position:0% +proportional to the current value and +the error was also uh dependent on the + + align:start position:0% +the error was also uh dependent on the + + + align:start position:0% +the error was also uh dependent on the +current value uh what is it proportional + + align:start position:0% +current value uh what is it proportional + + + align:start position:0% +current value uh what is it proportional +to the current value. But here now the + + align:start position:0% +to the current value. But here now the + + + align:start position:0% +to the current value. But here now the +drift term is something like an + + align:start position:0% +drift term is something like an + + + align:start position:0% +drift term is something like an +exponential minus + + align:start position:0% +exponential minus + + + align:start position:0% +exponential minus +exponential but still it's proportional + + align:start position:0% +exponential but still it's proportional + + + align:start position:0% +exponential but still it's proportional +to the current value but the error term + + align:start position:0% +to the current value but the error term + + + align:start position:0% +to the current value but the error term +is just some noise just irrelevant of + + align:start position:0% +is just some noise just irrelevant of + + + align:start position:0% +is just some noise just irrelevant of +what the value is. This has the same + + align:start position:0% +what the value is. This has the same + + + align:start position:0% +what the value is. This has the same +variance the error. So it's a slightly + + align:start position:0% +variance the error. So it's a slightly + + + align:start position:0% +variance the error. So it's a slightly +different + + align:start position:0% +different + + + align:start position:0% +different +uh what is it? It's a slightly different + + align:start position:0% +uh what is it? It's a slightly different + + + align:start position:0% +uh what is it? It's a slightly different +process and it's known as + + align:start position:0% + + + + align:start position:0% + +orange + + align:start position:0% + + + + align:start position:0% + +process + + align:start position:0% +process + + + align:start position:0% +process +lens + + align:start position:0% + + + + align:start position:0% + +process. Okay. And this is used to model + + align:start position:0% +process. Okay. And this is used to model + + + align:start position:0% +process. Okay. And this is used to model +a mean reverting stoastic process for + + align:start position:0% +a mean reverting stoastic process for + + + align:start position:0% +a mean reverting stoastic process for +alpha greater than zero. Notice that if + + align:start position:0% +alpha greater than zero. Notice that if + + + align:start position:0% +alpha greater than zero. Notice that if +x deviates from zero, this gives a force + + align:start position:0% +x deviates from zero, this gives a force + + + align:start position:0% +x deviates from zero, this gives a force +that drives the stoastic process back to + + align:start position:0% +that drives the stoastic process back to + + + align:start position:0% +that drives the stoastic process back to +zero. Okay, this negatively proportional + + align:start position:0% +zero. Okay, this negatively proportional + + + align:start position:0% +zero. Okay, this negatively proportional +to your current + + align:start position:0% + + + + align:start position:0% + +value. So yeah, this is used to model + + align:start position:0% +value. So yeah, this is used to model + + + align:start position:0% +value. So yeah, this is used to model +some mean reverting stoastic processes. + + align:start position:0% +some mean reverting stoastic processes. + + + align:start position:0% +some mean reverting stoastic processes. +and they first used it to what's it to + + align:start position:0% +and they first used it to what's it to + + + align:start position:0% +and they first used it to what's it to +study the behavior of + + align:start position:0% +study the behavior of + + + align:start position:0% +study the behavior of +gases. + + align:start position:0% +gases. + + + align:start position:0% +gases. +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +Okay, I don't exactly see why, but + + align:start position:0% +Okay, I don't exactly see why, but + + + align:start position:0% +Okay, I don't exactly see why, but +that's what they say. + + align:start position:0% +that's what they say. + + + align:start position:0% +that's what they say. +So anyway, so this is another thing that + + align:start position:0% +So anyway, so this is another thing that + + + align:start position:0% +So anyway, so this is another thing that +can be solved by doing similar + + align:start position:0% + + + + align:start position:0% + +analysis, but if you try the same + + align:start position:0% +analysis, but if you try the same + + + align:start position:0% +analysis, but if you try the same +method, it will + + align:start position:0% +method, it will + + + align:start position:0% +method, it will +fail. So it's a test function your guess + + align:start position:0% +fail. So it's a test function your guess + + + align:start position:0% +fail. So it's a test function your guess +initial guess will + + align:start position:0% + + + + align:start position:0% + +be a 0 is equal + + align:start position:0% + + + + align:start position:0% + +to so honestly I don't know how to come + + align:start position:0% +to so honestly I don't know how to come + + + align:start position:0% +to so honestly I don't know how to come +up with this + + align:start position:0% + + + + align:start position:0% + +Yes, probably if you're really + + align:start position:0% +Yes, probably if you're really + + + align:start position:0% +Yes, probably if you're really +experienced with the stoastic + + align:start position:0% +experienced with the stoastic + + + align:start position:0% +experienced with the stoastic +differential equations, you'll + + align:start position:0% +differential equations, you'll + + + align:start position:0% +differential equations, you'll +see like some form like you'll have some + + align:start position:0% +see like some form like you'll have some + + + align:start position:0% +see like some form like you'll have some +feeling on like how the process will + + align:start position:0% +feeling on like how the process will + + + align:start position:0% +feeling on like how the process will +look like and then try this, try that + + align:start position:0% +look like and then try this, try that + + + align:start position:0% +look like and then try this, try that +and eventually something might succeed. + + align:start position:0% +and eventually something might succeed. + + + align:start position:0% +and eventually something might succeed. +So that's the best explanation I can + + align:start position:0% +So that's the best explanation I can + + + align:start position:0% +So that's the best explanation I can +give. I can't really give you an + + align:start position:0% +give. I can't really give you an + + + align:start position:0% +give. I can't really give you an +intuition why that's the right guess + + align:start position:0% +intuition why that's the right guess + + + align:start position:0% +intuition why that's the right guess +given some stoastic differential + + align:start position:0% +given some stoastic differential + + + align:start position:0% +given some stoastic differential +equation. I don't know how to say that + + align:start position:0% +equation. I don't know how to say that + + + align:start position:0% +equation. I don't know how to say that +you should start with this kind of + + align:start position:0% +you should start with this kind of + + + align:start position:0% +you should start with this kind of +function this kind of function. Okay. + + align:start position:0% +function this kind of function. Okay. + + + align:start position:0% +function this kind of function. Okay. +And it was the same when if you remember + + align:start position:0% +And it was the same when if you remember + + + align:start position:0% +And it was the same when if you remember +how you solve like ordinary differential + + align:start position:0% +how you solve like ordinary differential + + + align:start position:0% +how you solve like ordinary differential +equations or partial differential + + align:start position:0% +equations or partial differential + + + align:start position:0% +equations or partial differential +equations. Most of the times there is no + + align:start position:0% +equations. Most of the times there is no + + + align:start position:0% +equations. Most of the times there is no +good guess. It's only when your given + + align:start position:0% +good guess. It's only when your given + + + align:start position:0% +good guess. It's only when your given +formula has some specific form such a + + align:start position:0% +formula has some specific form such a + + + align:start position:0% +formula has some specific form such a +thing + + align:start position:0% +thing + + + align:start position:0% +thing +happens. So let's see what happens here. + + align:start position:0% +happens. So let's see what happens here. + + + align:start position:0% +happens. So let's see what happens here. +that was + + align:start position:0% +that was + + + align:start position:0% +that was +given. Now let's do exactly the same as + + align:start position:0% +given. Now let's do exactly the same as + + + align:start position:0% +given. Now let's do exactly the same as +before. Differentiate + + align:start position:0% +before. Differentiate + + + align:start position:0% +before. Differentiate +it and let me go slow. So we have a + + align:start position:0% +it and let me go slow. So we have a + + + align:start position:0% +it and let me go slow. So we have a +prime of t by chain rule a prime of t + + align:start position:0% +prime of t by chain rule a prime of t + + + align:start position:0% +prime of t by chain rule a prime of t +and that + + align:start position:0% +and that + + + align:start position:0% +and that +value that part will be equal to xt over + + align:start position:0% +value that part will be equal to xt over + + + align:start position:0% +value that part will be equal to xt over +a + + align:start position:0% +a + + + align:start position:0% +a +t. This is chain rule. So I + + align:start position:0% +t. This is chain rule. So I + + + align:start position:0% +t. This is chain rule. So I +differentiate that to get a prime t. + + align:start position:0% +differentiate that to get a prime t. + + + align:start position:0% +differentiate that to get a prime t. +That stays just as it was. But that can + + align:start position:0% +That stays just as it was. But that can + + + align:start position:0% +That stays just as it was. But that can +be rewritten as xt / a t and then plus a + + align:start position:0% +be rewritten as xt / a t and then plus a + + + align:start position:0% +be rewritten as xt / a t and then plus a +t * the differential of that + + align:start position:0% +t * the differential of that + + + align:start position:0% +t * the differential of that +one. And that is just b t dbt. + + align:start position:0% + + + + align:start position:0% + +You don't have to differentiate that + + align:start position:0% +You don't have to differentiate that + + + align:start position:0% +You don't have to differentiate that +once more even though it's stochastic + + align:start position:0% +once more even though it's stochastic + + + align:start position:0% +once more even though it's stochastic +calculus because now that's a very + + align:start position:0% +calculus because now that's a very + + + align:start position:0% +calculus because now that's a very +subtle point and there's also one + + align:start position:0% +subtle point and there's also one + + + align:start position:0% +subtle point and there's also one +exercise about it in your homework. But + + align:start position:0% +exercise about it in your homework. But + + + align:start position:0% +exercise about it in your homework. But +when you're inte when you have a given + + align:start position:0% +when you're inte when you have a given + + + align:start position:0% +when you're inte when you have a given +stoastic process written already in this + + align:start position:0% +stoastic process written already in this + + + align:start position:0% +stoastic process written already in this +integral + + align:start position:0% +integral + + + align:start position:0% +integral +form if you remember the definition of + + align:start position:0% +form if you remember the definition of + + + align:start position:0% +form if you remember the definition of +an integral at least how I defined it is + + align:start position:0% +an integral at least how I defined it is + + + align:start position:0% +an integral at least how I defined it is +that it was an inverse operation of a + + align:start position:0% +that it was an inverse operation of a + + + align:start position:0% +that it was an inverse operation of a +differential. So when you differentiate + + align:start position:0% +differential. So when you differentiate + + + align:start position:0% +differential. So when you differentiate +this you just get that term. What I'm + + align:start position:0% +this you just get that term. What I'm + + + align:start position:0% +this you just get that term. What I'm +trying to say is there is no term no + + align:start position:0% +trying to say is there is no term no + + + align:start position:0% +trying to say is there is no term no +term where you have to differentiate + + align:start position:0% +term where you have to differentiate + + + align:start position:0% +term where you have to differentiate +this one + + align:start position:0% + + + + align:start position:0% + +more prime + + align:start position:0% +more prime + + + align:start position:0% +more prime +dt something like that you don't have + + align:start position:0% +dt something like that you don't have + + + align:start position:0% +dt something like that you don't have +this + + align:start position:0% + + + + align:start position:0% + +term. This can be confusing but think + + align:start position:0% +term. This can be confusing but think + + + align:start position:0% +term. This can be confusing but think +about it. + + align:start position:0% + + + + align:start position:0% + +Yeah. Okay. Now we laid it + + align:start position:0% +Yeah. Okay. Now we laid it + + + align:start position:0% +Yeah. Okay. Now we laid it +out and just compare. So minus alpha of + + align:start position:0% +out and just compare. So minus alpha of + + + align:start position:0% +out and just compare. So minus alpha of +x of t is equal to a prime t / a + + align:start position:0% +x of t is equal to a prime t / a + + + align:start position:0% +x of t is equal to a prime t / a +t + + align:start position:0% +t + + + align:start position:0% +t +xt. And your second term a uh sigma dbt + + align:start position:0% +xt. And your second term a uh sigma dbt + + + align:start position:0% +xt. And your second term a uh sigma dbt +is equal to a t * + + align:start position:0% + + + + align:start position:0% + +bt. Okay. But these two + + align:start position:0% +bt. Okay. But these two + + + align:start position:0% +bt. Okay. But these two +cancel and we see that uh a t has to + + align:start position:0% +cancel and we see that uh a t has to + + + align:start position:0% +cancel and we see that uh a t has to +be e to the minus alpha + + align:start position:0% + + + + align:start position:0% + +tus. This says that it's an + + align:start position:0% +tus. This says that it's an + + + align:start position:0% +tus. This says that it's an +exponential. Now plug it in here. you + + align:start position:0% +exponential. Now plug it in here. you + + + align:start position:0% +exponential. Now plug it in here. you +get + + align:start position:0% + + + + align:start position:0% + +BT. That's it. So plug it back in. X of + + align:start position:0% +BT. That's it. So plug it back in. X of + + + align:start position:0% +BT. That's it. So plug it back in. X of +t is e to the minus alpha t of x + + align:start position:0% +t is e to the minus alpha t of x + + + align:start position:0% +t is e to the minus alpha t of x +of0 plus 0 to + + align:start position:0% +of0 plus 0 to + + + align:start position:0% +of0 plus 0 to +t sigma to the alpha s + + align:start position:0% + + + + align:start position:0% + +Okay, so this is a variance expectation + + align:start position:0% +Okay, so this is a variance expectation + + + align:start position:0% +Okay, so this is a variance expectation +is + + align:start position:0% +is + + + align:start position:0% +is +zero because that's a brownian motion. + + align:start position:0% +zero because that's a brownian motion. + + + align:start position:0% +zero because that's a brownian motion. +This term as we expected as time passes + + align:start position:0% +This term as we expected as time passes + + + align:start position:0% +This term as we expected as time passes +goes to + + align:start position:0% +goes to + + + align:start position:0% +goes to +zero. Okay, exponential + + align:start position:0% +zero. Okay, exponential + + + align:start position:0% +zero. Okay, exponential +decay and that is kind of hinted by this + + align:start position:0% +decay and that is kind of hinted by this + + + align:start position:0% +decay and that is kind of hinted by this +fact the mean reversion. So if you start + + align:start position:0% +fact the mean reversion. So if you start + + + align:start position:0% +fact the mean reversion. So if you start +from some value at least the drift term + + align:start position:0% +from some value at least the drift term + + + align:start position:0% +from some value at least the drift term +will go to zero quite + + align:start position:0% +will go to zero quite + + + align:start position:0% +will go to zero quite +quickly and then the important term will + + align:start position:0% +quickly and then the important term will + + + align:start position:0% +quickly and then the important term will +be the noise term or the variance + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +term. Any + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +questions? + + align:start position:0% +questions? + + + align:start position:0% +questions? +Okay. And I'm really emphasizing a a lot + + align:start position:0% +Okay. And I'm really emphasizing a a lot + + + align:start position:0% +Okay. And I'm really emphasizing a a lot +of times this a lot of times today or + + align:start position:0% +of times this a lot of times today or + + + align:start position:0% +of times this a lot of times today or +really you can forget about what I did + + align:start position:0% +really you can forget about what I did + + + align:start position:0% +really you can forget about what I did +in the past two boards this board and + + align:start position:0% +in the past two boards this board and + + + align:start position:0% +in the past two boards this board and +the previous board because most of the + + align:start position:0% +the previous board because most of the + + + align:start position:0% +the previous board because most of the +times it will be + + align:start position:0% +times it will be + + + align:start position:0% +times it will be +useless. And so now I will describe what + + align:start position:0% +useless. And so now I will describe what + + + align:start position:0% +useless. And so now I will describe what +you will do if you're given a stoastic + + align:start position:0% +you will do if you're given a stoastic + + + align:start position:0% +you will do if you're given a stoastic +differential equation and you have a + + align:start position:0% +differential equation and you have a + + + align:start position:0% +differential equation and you have a +computer in front of you. + + align:start position:0% + + + + align:start position:0% + +What if such method + + align:start position:0% + + + + align:start position:0% + +fails? And it will fail most of the + + align:start position:0% + + + + align:start position:0% + +times. + + align:start position:0% +times. + + + align:start position:0% +times. +Okay, that's when we use these + + align:start position:0% +Okay, that's when we use these + + + align:start position:0% +Okay, that's when we use these +techniques called finite difference + + align:start position:0% +techniques called finite difference + + + align:start position:0% +techniques called finite difference +method. + + align:start position:0% + + + + align:start position:0% + +Monte Carlo + + align:start position:0% + + + + align:start position:0% + +simulation our tree + + align:start position:0% +simulation our tree + + + align:start position:0% +simulation our tree +method. + + align:start position:0% +method. + + + align:start position:0% +method. +[Applause] + + align:start position:0% + + + + align:start position:0% + +Yes, the finite difference method. You + + align:start position:0% +Yes, the finite difference method. You + + + align:start position:0% +Yes, the finite difference method. You +probably already saw it if you saw uh + + align:start position:0% +probably already saw it if you saw uh + + + align:start position:0% +probably already saw it if you saw uh +took a differential equation course, but + + align:start position:0% +took a differential equation course, but + + + align:start position:0% +took a differential equation course, but +let me review + + align:start position:0% + + + + align:start position:0% + +it. This is for + + align:start position:0% +it. This is for + + + align:start position:0% +it. This is for +PDEs or ODS for OD PD not stoastic + + align:start position:0% +PDEs or ODS for OD PD not stoastic + + + align:start position:0% +PDEs or ODS for OD PD not stoastic +differential equations but it can be + + align:start position:0% +differential equations but it can be + + + align:start position:0% +differential equations but it can be +adapted to work for stoastic + + align:start position:0% +adapted to work for stoastic + + + align:start position:0% +adapted to work for stoastic +differential equations. So I I'll work + + align:start position:0% +differential equations. So I I'll work + + + align:start position:0% +differential equations. So I I'll work +with an + + align:start position:0% + + + + align:start position:0% + +example. Let U of T be U prime of + + align:start position:0% +example. Let U of T be U prime of + + + align:start position:0% +example. Let U of T be U prime of +T + + + align:start position:0% + + + + align:start position:0% + +2. Huh? U prime of T be U + + align:start position:0% +2. Huh? U prime of T be U + + + align:start position:0% +2. Huh? U prime of T be U +T + 2. U Z is equal to + + align:start position:0% +T + 2. U Z is equal to + + + align:start position:0% +T + 2. U Z is equal to +Z. Now this has an exact solution, but + + align:start position:0% +Z. Now this has an exact solution, but + + + align:start position:0% +Z. Now this has an exact solution, but +let's pretend that there is no exact + + align:start position:0% +let's pretend that there is no exact + + + align:start position:0% +let's pretend that there is no exact +solution. And if you want to do it + + align:start position:0% + + + + align:start position:0% + +numerically, you want to find the value + + align:start position:0% +numerically, you want to find the value + + + align:start position:0% +numerically, you want to find the value +of u = u1 + + align:start position:0% + + + + align:start position:0% + +numerically. Here's what you're going to + + align:start position:0% +numerically. Here's what you're going to + + + align:start position:0% +numerically. Here's what you're going to +do. You're going to chop up the interval + + align:start position:0% +do. You're going to chop up the interval + + + align:start position:0% +do. You're going to chop up the interval +from 0 to one into very fine pieces. So + + align:start position:0% +from 0 to one into very fine pieces. So + + + align:start position:0% +from 0 to one into very fine pieces. So +from 0 to + + align:start position:0% +from 0 to + + + align:start position:0% +from 0 to +one, chop it down into tiny + + align:start position:0% + + + + align:start position:0% + +pieces. And since I'm in front of a + + align:start position:0% +pieces. And since I'm in front of a + + + align:start position:0% +pieces. And since I'm in front of a +blackboard, my tiny piece will be one + + align:start position:0% +blackboard, my tiny piece will be one + + + align:start position:0% +blackboard, my tiny piece will be one +over two and one. I'll just take two + + align:start position:0% +over two and one. I'll just take two + + + align:start position:0% +over two and one. I'll just take two +steps. + + align:start position:0% +steps. + + + align:start position:0% +steps. +But you should think of it as really + + align:start position:0% +But you should think of it as really + + + align:start position:0% +But you should think of it as really +repeating this a lot of + + align:start position:0% +repeating this a lot of + + + align:start position:0% +repeating this a lot of +times. I'll call my step to be h. So in + + align:start position:0% +times. I'll call my step to be h. So in + + + align:start position:0% +times. I'll call my step to be h. So in +my case, I'm increasing my steps by one + + align:start position:0% +my case, I'm increasing my steps by one + + + align:start position:0% +my case, I'm increasing my steps by one +over two at each + + align:start position:0% +over two at each + + + align:start position:0% +over two at each +time. So what is u of 1 + + align:start position:0% +time. So what is u of 1 + + + align:start position:0% +time. So what is u of 1 +/2? Approximately by Taylor's formula, + + align:start position:0% +/2? Approximately by Taylor's formula, + + + align:start position:0% +/2? Approximately by Taylor's formula, +it's + + align:start position:0% +it's + + + align:start position:0% +it's +u0 + + align:start position:0% +u0 + + + align:start position:0% +u0 +plus 12 * u prime of 0. That's + + align:start position:0% +plus 12 * u prime of 0. That's + + + align:start position:0% +plus 12 * u prime of 0. That's +approximation. + + align:start position:0% +approximation. + + + align:start position:0% +approximation. +Okay, U0 we already know is given to be + + align:start position:0% +Okay, U0 we already know is given to be + + + align:start position:0% +Okay, U0 we already know is given to be +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +zero. U prime of 0 on the other hand is + + align:start position:0% +zero. U prime of 0 on the other hand is + + + align:start position:0% +zero. U prime of 0 on the other hand is +given by this differential + + align:start position:0% +given by this differential + + + align:start position:0% +given by this differential +equation. So it's 1 / 2 * 5 * u 0 + 2 u0 + + align:start position:0% +equation. So it's 1 / 2 * 5 * u 0 + 2 u0 + + + align:start position:0% +equation. So it's 1 / 2 * 5 * u 0 + 2 u0 +is 0. So we get equal to + + align:start position:0% + + + + align:start position:0% + +one like we have this value equal to one + + align:start position:0% +one like we have this value equal to one + + + align:start position:0% +one like we have this value equal to one +approximately I don't know what happens + + align:start position:0% +approximately I don't know what happens + + + align:start position:0% +approximately I don't know what happens +but it will be close to one and then for + + align:start position:0% +but it will be close to one and then for + + + align:start position:0% +but it will be close to one and then for +the next thing + + align:start position:0% +the next thing + + + align:start position:0% +the next thing +u1 this one is again by tailaylor + + align:start position:0% +u1 this one is again by tailaylor + + + align:start position:0% +u1 this one is again by tailaylor +approximation it's u of 1 + + align:start position:0% +approximation it's u of 1 + + + align:start position:0% +approximation it's u of 1 +/2 plus 1 /2 u prime of 1 + + align:start position:0% + + + + align:start position:0% + +/2 and now you know the value of u of 1 + + align:start position:0% +/2 and now you know the value of u of 1 + + + align:start position:0% +/2 and now you know the value of u of 1 +/2 approximate value by this so plug it + + align:start position:0% +/2 approximate value by this so plug it + + + align:start position:0% +/2 approximate value by this so plug it +in you have 1 + 1 /2 and again 5 * u1 /2 + + align:start position:0% +in you have 1 + 1 /2 and again 5 * u1 /2 + + + align:start position:0% +in you have 1 + 1 /2 and again 5 * u1 /2 ++ 2 which when you do the computation it + + align:start position:0% ++ 2 which when you do the computation it + + + align:start position:0% ++ 2 which when you do the computation it +should give 9 + + align:start position:0% + + + + align:start position:0% + +/2. It's really + + align:start position:0% +/2. It's really + + + align:start position:0% +/2. It's really +simple. The key idea here is just u + + align:start position:0% +simple. The key idea here is just u + + + align:start position:0% +simple. The key idea here is just u +prime is given by an + + align:start position:0% +prime is given by an + + + align:start position:0% +prime is given by an +equation this equation. So you can + + align:start position:0% +equation this equation. So you can + + + align:start position:0% +equation this equation. So you can +compute it once you know the value of u + + align:start position:0% +compute it once you know the value of u + + + align:start position:0% +compute it once you know the value of u +at that point. Okay. And basically the + + align:start position:0% +at that point. Okay. And basically the + + + align:start position:0% +at that point. Okay. And basically the +method is saying take H to be very small + + align:start position:0% +method is saying take H to be very small + + + align:start position:0% +method is saying take H to be very small +like one over 100. Then you just repeat + + align:start position:0% +like one over 100. Then you just repeat + + + align:start position:0% +like one over 100. Then you just repeat +it one over 100 times. So the equation + + align:start position:0% +it one over 100 times. So the equation + + + align:start position:0% +it one over 100 times. So the equation +is the I + one step value can be + + align:start position:0% +is the I + one step value can be + + + align:start position:0% +is the I + one step value can be +approximated from the ice + + align:start position:0% +approximated from the ice + + + align:start position:0% +approximated from the ice +value plus uh H * U prime by + + align:start position:0% +value plus uh H * U prime by + + + align:start position:0% +value plus uh H * U prime by +H and repeat it and repeat it and you + + align:start position:0% +H and repeat it and repeat it and you + + + align:start position:0% +H and repeat it and repeat it and you +reach U of one. And there's a theorem + + align:start position:0% +reach U of one. And there's a theorem + + + align:start position:0% +reach U of one. And there's a theorem +saying again if u is a reasonable fun if + + align:start position:0% +saying again if u is a reasonable fun if + + + align:start position:0% +saying again if u is a reasonable fun if +the differential equation is reasonable + + align:start position:0% +the differential equation is reasonable + + + align:start position:0% +the differential equation is reasonable +then that will approach the true value + + align:start position:0% +then that will approach the true value + + + align:start position:0% +then that will approach the true value +as you take h to be smaller and smaller. + + align:start position:0% +as you take h to be smaller and smaller. + + + align:start position:0% +as you take h to be smaller and smaller. +Okay that's called the finite difference + + align:start position:0% +Okay that's called the finite difference + + + align:start position:0% +Okay that's called the finite difference +method for differential + + align:start position:0% +method for differential + + + align:start position:0% +method for differential +equations. And you can do the exact same + + align:start position:0% +equations. And you can do the exact same + + + align:start position:0% +equations. And you can do the exact same +thing for two variables. Let's + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +see. And what we showed was for one + + align:start position:0% +see. And what we showed was for one + + + align:start position:0% +see. And what we showed was for one +variable finite difference + + align:start position:0% + + + + align:start position:0% + +method. We want to find the value of u + + align:start position:0% +method. We want to find the value of u + + + align:start position:0% +method. We want to find the value of u +function u of + + align:start position:0% +function u of + + + align:start position:0% +function u of +t. We took values of 0 h 2 h 3 h. using + + align:start position:0% +t. We took values of 0 h 2 h 3 h. using + + + align:start position:0% +t. We took values of 0 h 2 h 3 h. using +that we did some approximation like that + + align:start position:0% +that we did some approximation like that + + + align:start position:0% +that we did some approximation like that +and found the + + align:start position:0% +and found the + + + align:start position:0% +and found the +value. Now suppose we want to find + + align:start position:0% +value. Now suppose we want to find + + + align:start position:0% +value. Now suppose we want to find +similarly a two variable function let's + + align:start position:0% +similarly a two variable function let's + + + align:start position:0% +similarly a two variable function let's +say v of t and + + align:start position:0% +say v of t and + + + align:start position:0% +say v of t and +x and we want to find the value of v of + + align:start position:0% +x and we want to find the value of v of + + + align:start position:0% +x and we want to find the value of v of + + align:start position:0% + + + align:start position:0% +one now the boundary conditions are + + align:start position:0% +one now the boundary conditions are + + + align:start position:0% +one now the boundary conditions are +these we already know these + + align:start position:0% + + + + align:start position:0% + +values I won't really show you by + + align:start position:0% +values I won't really show you by + + + align:start position:0% +values I won't really show you by +example but what we're going to do now + + align:start position:0% +example but what we're going to do now + + + align:start position:0% +example but what we're going to do now +is compute this value based on these two + + align:start position:0% +is compute this value based on these two + + + align:start position:0% +is compute this value based on these two +variable okay so it's Just the same + + align:start position:0% +variable okay so it's Just the same + + + align:start position:0% +variable okay so it's Just the same +tailor expansion for two variables will + + align:start position:0% +tailor expansion for two variables will + + + align:start position:0% +tailor expansion for two variables will +allow you to compute this value from + + align:start position:0% +allow you to compute this value from + + + align:start position:0% +allow you to compute this value from +these two variable values. Then compute + + align:start position:0% +these two variable values. Then compute + + + align:start position:0% +these two variable values. Then compute +this from these two. That's from these + + align:start position:0% +this from these two. That's from these + + + align:start position:0% +this from these two. That's from these +two. Just fill out the whole grid like + + align:start position:0% +two. Just fill out the whole grid like + + + align:start position:0% +two. Just fill out the whole grid like +that. Just fill out layer by + + align:start position:0% +that. Just fill out layer by + + + align:start position:0% +that. Just fill out layer by +layer. At some point you're going to + + align:start position:0% +layer. At some point you're going to + + + align:start position:0% +layer. At some point you're going to +reach this and then you'll have an + + align:start position:0% +reach this and then you'll have an + + + align:start position:0% +reach this and then you'll have an +approximate value of that. Okay? So you + + align:start position:0% +approximate value of that. Okay? So you + + + align:start position:0% +approximate value of that. Okay? So you +chop up your domain into fine + + align:start position:0% +chop up your domain into fine + + + align:start position:0% +chop up your domain into fine +pieces and then take the limit and most + + align:start position:0% +pieces and then take the limit and most + + + align:start position:0% +pieces and then take the limit and most +cases it will work. + + align:start position:0% +cases it will work. + + + align:start position:0% +cases it will work. +Okay, why does it not work for stokastic + + align:start position:0% +Okay, why does it not work for stokastic + + + align:start position:0% +Okay, why does it not work for stokastic +differential + + align:start position:0% + + + + align:start position:0% + +equations kind of works but the only + + align:start position:0% +equations kind of works but the only + + + align:start position:0% +equations kind of works but the only +problem is we don't know which value + + align:start position:0% +problem is we don't know which value + + + align:start position:0% +problem is we don't know which value +we're looking at. we want we're + + align:start position:0% +we're looking at. we want we're + + + align:start position:0% +we're looking at. we want we're +interested + + align:start position:0% +interested + + + align:start position:0% +interested +in. So let me phrase it a little + + align:start position:0% +in. So let me phrase it a little + + + align:start position:0% +in. So let me phrase it a little +bit + + align:start position:0% + + + + align:start position:0% + +differently. You're given a differential + + align:start position:0% +differently. You're given a differential + + + align:start position:0% +differently. You're given a differential +equation of the form dx= mud dt plus + + align:start position:0% + + + + align:start position:0% + +t dv of + + align:start position:0% +t dv of + + + align:start position:0% +t dv of +t. Okay. + + align:start position:0% + + + + align:start position:0% + +and time + + align:start position:0% +and time + + + align:start position:0% +and time +variable and space variable. + + align:start position:0% +variable and space variable. + + + align:start position:0% +variable and space variable. +So if you want to compute your value at + + align:start position:0% +So if you want to compute your value at + + + align:start position:0% +So if you want to compute your value at +time uh h 2 h based on value + + align:start position:0% + + + + align:start position:0% + +h in this picture I told you that this + + align:start position:0% +h in this picture I told you that this + + + align:start position:0% +h in this picture I told you that this +point came from these two + + align:start position:0% +point came from these two + + + align:start position:0% +point came from these two +points but when it's + + align:start position:0% + + + + align:start position:0% + +stochastic it could depend on everything + + align:start position:0% +stochastic it could depend on everything + + + align:start position:0% +stochastic it could depend on everything +you don't know where it came from. This + + align:start position:0% +you don't know where it came from. This + + + align:start position:0% +you don't know where it came from. This +point could have come from here. It + + align:start position:0% +point could have come from here. It + + + align:start position:0% +point could have come from here. It +could have came from here. It could have + + align:start position:0% +could have came from here. It could have + + + align:start position:0% +could have came from here. It could have +came from here. Came from here. You + + align:start position:0% +came from here. Came from here. You + + + align:start position:0% +came from here. Came from here. You +don't really know. But what you know is + + align:start position:0% +don't really know. But what you know is + + + align:start position:0% +don't really know. But what you know is +you have a probability + + align:start position:0% +you have a probability + + + align:start position:0% +you have a probability +distribution. + + align:start position:0% + + + + align:start position:0% + +So yeah, what what I'm trying to say is + + align:start position:0% +So yeah, what what I'm trying to say is + + + align:start position:0% +So yeah, what what I'm trying to say is +now if you want to adapt this method, + + align:start position:0% +now if you want to adapt this method, + + + align:start position:0% +now if you want to adapt this method, +what you're going to do is + + align:start position:0% +what you're going to do is + + + align:start position:0% +what you're going to do is +take a sample brownian motion + + align:start position:0% + + + + align:start position:0% + +path. That means just according to the + + align:start position:0% +path. That means just according to the + + + align:start position:0% +path. That means just according to the +rand uh distribution of the brownian + + align:start position:0% +rand uh distribution of the brownian + + + align:start position:0% +rand uh distribution of the brownian +motion take one + + align:start position:0% +motion take one + + + align:start position:0% +motion take one +pass and use that pass. Once we fix a + + align:start position:0% +pass and use that pass. Once we fix a + + + align:start position:0% +pass and use that pass. Once we fix a +pass once a pass is + + align:start position:0% + + + + align:start position:0% + +fixed we can exactly know where each + + align:start position:0% +fixed we can exactly know where each + + + align:start position:0% +fixed we can exactly know where each +value comes from. We + + align:start position:0% +value comes from. We + + + align:start position:0% +value comes from. We +know how to + + align:start position:0% + + + + align:start position:0% + +backtrack. That means instead of all + + align:start position:0% +backtrack. That means instead of all + + + align:start position:0% +backtrack. That means instead of all +these possibilities, we have one fixed + + align:start position:0% +these possibilities, we have one fixed + + + align:start position:0% +these possibilities, we have one fixed +possibility like + + align:start position:0% +possibility like + + + align:start position:0% +possibility like +that. + + align:start position:0% +that. + + + align:start position:0% +that. +Okay. So just use that finite difference + + align:start position:0% +Okay. So just use that finite difference + + + align:start position:0% +Okay. So just use that finite difference +method. What's that fixed + + align:start position:0% +method. What's that fixed + + + align:start position:0% +method. What's that fixed +pass? That will be the idea. + + align:start position:0% + + + + align:start position:0% + +Let me do it a little bit more + + align:start position:0% + + + + align:start position:0% + +formally. So here is how it + + align:start position:0% +formally. So here is how it + + + align:start position:0% +formally. So here is how it +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +works. + + align:start position:0% +works. + + + align:start position:0% +works. +If we have a + + align:start position:0% + + + + align:start position:0% + +fixed sample pass for bound + + align:start position:0% +fixed sample pass for bound + + + align:start position:0% +fixed sample pass for bound +motion of + + align:start position:0% +motion of + + + align:start position:0% +motion of +BT, + + align:start position:0% +BT, + + + align:start position:0% +BT, +then X at time I + 1 of + + align:start position:0% +then X at time I + 1 of + + + align:start position:0% +then X at time I + 1 of +H is equal to approximately equal to X + + align:start position:0% +H is equal to approximately equal to X + + + align:start position:0% +H is equal to approximately equal to X +at time A of H. + + align:start position:0% + + + + align:start position:0% + +plus h * + + align:start position:0% +plus h * + + + align:start position:0% +plus h * +dx at that time a + + align:start position:0% +dx at that time a + + + align:start position:0% +dx at that time a +ih just by the exact same uh scalar + + align:start position:0% +ih just by the exact same uh scalar + + + align:start position:0% +ih just by the exact same uh scalar +expression and then d of x we know to + + align:start position:0% + + + + align:start position:0% + +be that is equal to + + align:start position:0% +be that is equal to + + + align:start position:0% +be that is equal to +mu of + + align:start position:0% +mu of + + + align:start position:0% +mu of +dt + + align:start position:0% + + + + align:start position:0% + +plus oh mu of dt is h. So let me write + + align:start position:0% +plus oh mu of dt is h. So let me write + + + align:start position:0% +plus oh mu of dt is h. So let me write +it like that. Sigma time d of x + + align:start position:0% + + + + align:start position:0% + +db and these mu depend on their passes + + align:start position:0% + + + + align:start position:0% + +right x at i of + + align:start position:0% +right x at i of + + + align:start position:0% +right x at i of +h + + align:start position:0% +h + + + align:start position:0% +h +dt sigma + + align:start position:0% + + + + align:start position:0% + +So that here to here is tailor + + align:start position:0% +So that here to here is tailor + + + align:start position:0% +So that here to here is tailor +expansion. Here to here I'm going to use + + align:start position:0% +expansion. Here to here I'm going to use + + + align:start position:0% +expansion. Here to here I'm going to use +the differential equation. D of x is + + align:start position:0% +the differential equation. D of x is + + + align:start position:0% +the differential equation. D of x is +equal to mud dt plus sigma dbt. Yes. Do + + align:start position:0% +equal to mud dt plus sigma dbt. Yes. Do + + + align:start position:0% +equal to mud dt plus sigma dbt. Yes. Do +we need that before? No we don't + + align:start position:0% +we need that before? No we don't + + + align:start position:0% +we need that before? No we don't +actually. Oh yeah I was. Thank you very + + align:start position:0% +actually. Oh yeah I was. Thank you very + + + align:start position:0% +actually. Oh yeah I was. Thank you very +much. That was what confused + + align:start position:0% +much. That was what confused + + + align:start position:0% +much. That was what confused +me. Yes, thank you very much. And now we + + align:start position:0% +me. Yes, thank you very much. And now we + + + align:start position:0% +me. Yes, thank you very much. And now we +can compute everything. This one we're + + align:start position:0% +can compute everything. This one we're + + + align:start position:0% +can compute everything. This one we're +assuming that we know the + + align:start position:0% +assuming that we know the + + + align:start position:0% +assuming that we know the +value. That one can be computed from + + align:start position:0% +value. That one can be computed from + + + align:start position:0% +value. That one can be computed from +these two coordinates because we we now + + align:start position:0% +these two coordinates because we we now + + + align:start position:0% +these two coordinates because we we now +have a fixed fixed path x. We know what + + align:start position:0% +have a fixed fixed path x. We know what + + + align:start position:0% +have a fixed fixed path x. We know what +x of ih is dt. We take it to be h + + align:start position:0% +x of ih is dt. We take it to be h + + + align:start position:0% +x of ih is dt. We take it to be h +approximated as h or time difference. + + align:start position:0% +approximated as h or time difference. + + + align:start position:0% +approximated as h or time difference. +Again sigma can be computed DB now can + + align:start position:0% +Again sigma can be computed DB now can + + + align:start position:0% +Again sigma can be computed DB now can +be computed from BT because we have a + + align:start position:0% +be computed from BT because we have a + + + align:start position:0% +be computed from BT because we have a +fixed path again we know that is equal + + align:start position:0% +fixed path again we know that is equal + + + align:start position:0% +fixed path again we know that is equal +to B of I + 1 of H minus B of I of + + align:start position:0% +to B of I + 1 of H minus B of I of + + + align:start position:0% +to B of I + 1 of H minus B of I of +H where's this fixed path they're + + align:start position:0% +H where's this fixed path they're + + + align:start position:0% +H where's this fixed path they're +basically exactly the same if you have a + + align:start position:0% +basically exactly the same if you have a + + + align:start position:0% +basically exactly the same if you have a +fixed path + + align:start position:0% +fixed path + + + align:start position:0% +fixed path +B the problem is we don't have a fixed + + align:start position:0% +B the problem is we don't have a fixed + + + align:start position:0% +B the problem is we don't have a fixed +path B that's where Monte Carlo + + align:start position:0% +path B that's where Monte Carlo + + + align:start position:0% +path B that's where Monte Carlo +simulation comes + + align:start position:0% + + + + align:start position:0% + +Okay, so Monte Carlo simulation is just + + align:start position:0% +Okay, so Monte Carlo simulation is just + + + align:start position:0% +Okay, so Monte Carlo simulation is just +a way to draw from some uh probability + + align:start position:0% +a way to draw from some uh probability + + + align:start position:0% +a way to draw from some uh probability +distribution a lot of samples. So if you + + align:start position:0% +distribution a lot of samples. So if you + + + align:start position:0% +distribution a lot of samples. So if you +know now if you know can know how to + + align:start position:0% +know now if you know can know how to + + + align:start position:0% +know now if you know can know how to +draw samples from the brownian motions + + align:start position:0% +draw samples from the brownian motions + + + align:start position:0% +draw samples from the brownian motions +and what you're going to do is draw a + + align:start position:0% +and what you're going to do is draw a + + + align:start position:0% +and what you're going to do is draw a +lot of samples for each sample do this + + align:start position:0% +lot of samples for each sample do this + + + align:start position:0% +lot of samples for each sample do this +to compute the value of x0 can + + align:start position:0% +to compute the value of x0 can + + + align:start position:0% +to compute the value of x0 can +compute x of + + align:start position:0% +compute x of + + + align:start position:0% +compute x of +one. So according to a different B + + align:start position:0% +one. So according to a different B + + + align:start position:0% +one. So according to a different B +you'll get a different value and in the + + align:start position:0% +you'll get a different value and in the + + + align:start position:0% +you'll get a different value and in the +end you'll have obtain a probability + + align:start position:0% +end you'll have obtain a probability + + + align:start position:0% +end you'll have obtain a probability +distribution. So by repeating the + + align:start position:0% + + + + align:start position:0% + +experiment + + align:start position:0% +experiment + + + align:start position:0% +experiment +experiment that means just redraw the + + align:start position:0% +experiment that means just redraw the + + + align:start position:0% +experiment that means just redraw the +path again and again you'll get + + align:start position:0% +path again and again you'll get + + + align:start position:0% +path again and again you'll get +different values of x sub1 that means + + align:start position:0% +different values of x sub1 that means + + + align:start position:0% +different values of x sub1 that means +you get a distribution of x of one + + align:start position:0% +you get a distribution of x of one + + + align:start position:0% +you get a distribution of x of one +obtain + + align:start position:0% +obtain + + + align:start position:0% +obtain +distribution of x + + align:start position:0% +distribution of x + + + align:start position:0% +distribution of x +sub1 and that's + + align:start position:0% +sub1 and that's + + + align:start position:0% +sub1 and that's +it and that will approach the real + + align:start position:0% +it and that will approach the real + + + align:start position:0% +it and that will approach the real +distribution of x sub1. + + align:start position:0% + + + + align:start position:0% + +So that's how you numerically solve a + + align:start position:0% +So that's how you numerically solve a + + + align:start position:0% +So that's how you numerically solve a +stoastic differential + + align:start position:0% +stoastic differential + + + align:start position:0% +stoastic differential +equation. Again there's this finite + + align:start position:0% +equation. Again there's this finite + + + align:start position:0% +equation. Again there's this finite +difference method that can be used to + + align:start position:0% +difference method that can be used to + + + align:start position:0% +difference method that can be used to +solve differential + + align:start position:0% +solve differential + + + align:start position:0% +solve differential +equations. But the reason it doesn't + + align:start position:0% +equations. But the reason it doesn't + + + align:start position:0% +equations. But the reason it doesn't +apply to stoastic differential equations + + align:start position:0% +apply to stoastic differential equations + + + align:start position:0% +apply to stoastic differential equations +is because there's underlying + + align:start position:0% +is because there's underlying + + + align:start position:0% +is because there's underlying +uncertainty that coming from Brownian + + align:start position:0% +uncertainty that coming from Brownian + + + align:start position:0% +uncertainty that coming from Brownian +motion. However, once you fix a brownian + + align:start position:0% +motion. However, once you fix a brownian + + + align:start position:0% +motion. However, once you fix a brownian +motion, then you can use that finite + + align:start position:0% +motion, then you can use that finite + + + align:start position:0% +motion, then you can use that finite +difference method to compute X of one. + + align:start position:0% +difference method to compute X of one. + + + align:start position:0% +difference method to compute X of one. +So based on that idea, you just draw a + + align:start position:0% +So based on that idea, you just draw a + + + align:start position:0% +So based on that idea, you just draw a +lot of samples of the Brownian + + align:start position:0% +lot of samples of the Brownian + + + align:start position:0% +lot of samples of the Brownian +pass draw uh compute a lot of values X + + align:start position:0% +pass draw uh compute a lot of values X + + + align:start position:0% +pass draw uh compute a lot of values X +of one and obtain a probability + + align:start position:0% +of one and obtain a probability + + + align:start position:0% +of one and obtain a probability +distribution of X of one. + + align:start position:0% +distribution of X of one. + + + align:start position:0% +distribution of X of one. +Okay, that's the underlying + + align:start position:0% +Okay, that's the underlying + + + align:start position:0% +Okay, that's the underlying +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +principle. And of course, you can't do + + align:start position:0% +principle. And of course, you can't do + + + align:start position:0% +principle. And of course, you can't do +it by hand, so you need a computer. + + align:start position:0% + + + + align:start position:0% + +Then what is tree + + align:start position:0% +Then what is tree + + + align:start position:0% +Then what is tree +method? That's + + align:start position:0% +method? That's + + + align:start position:0% +method? That's +cool. Tree method is based on this idea. + + align:start position:0% +cool. Tree method is based on this idea. + + + align:start position:0% +cool. Tree method is based on this idea. +If you remember boundarian + + align:start position:0% + + + + align:start position:0% + +motion is a + + align:start position:0% + + + + align:start position:0% + +limit + + align:start position:0% +limit + + + align:start position:0% +limit +of simple random + + align:start position:0% + + + + align:start position:0% + +walk. + + align:start position:0% +walk. + + + align:start position:0% +walk. +Okay, th this gives you a kind of + + align:start position:0% +Okay, th this gives you a kind of + + + align:start position:0% +Okay, th this gives you a kind of +approximate way to draw brown motions. + + align:start position:0% +approximate way to draw brown motions. + + + align:start position:0% +approximate way to draw brown motions. +Draw a sample from Brownium motions. How + + align:start position:0% +Draw a sample from Brownium motions. How + + + align:start position:0% +Draw a sample from Brownium motions. How +do you do + + align:start position:0% + + + + align:start position:0% + +that? At time zero, you have zero. At + + align:start position:0% +that? At time zero, you have zero. At + + + align:start position:0% +that? At time zero, you have zero. At +time really time uh tiny + + align:start position:0% +time really time uh tiny + + + align:start position:0% +time really time uh tiny +h you'll have + one or minus one with + + align:start position:0% +h you'll have + one or minus one with + + + align:start position:0% +h you'll have + one or minus one with +same probability. + + align:start position:0% +same probability. + + + align:start position:0% +same probability. +Then it goes up or down again, up or + + align:start position:0% +Then it goes up or down again, up or + + + align:start position:0% +Then it goes up or down again, up or +down + + align:start position:0% + + + + align:start position:0% + +again and so + + align:start position:0% +again and so + + + align:start position:0% +again and so +on. And you know exactly the probability + + align:start position:0% + + + + align:start position:0% + +distribution. So the probability that it + + align:start position:0% +distribution. So the probability that it + + + align:start position:0% +distribution. So the probability that it +ends up here is half ends up here is + + align:start position:0% +ends up here is half ends up here is + + + align:start position:0% +ends up here is half ends up here is +half + + align:start position:0% +half + + + align:start position:0% +half +1/4 and so on. So instead of drawing + + align:start position:0% +1/4 and so on. So instead of drawing + + + align:start position:0% +1/4 and so on. So instead of drawing +from this sample path, what you're going + + align:start position:0% +from this sample path, what you're going + + + align:start position:0% +from this sample path, what you're going +to do is just compute every val compute + + align:start position:0% +to do is just compute every val compute + + + align:start position:0% +to do is just compute every val compute +the value of our function at these + + align:start position:0% +the value of our function at these + + + align:start position:0% +the value of our function at these +points. + + align:start position:0% + + + + align:start position:0% + +But then the probability distribution + + align:start position:0% +But then the probability distribution + + + align:start position:0% +But then the probability distribution +because we know the probability + + align:start position:0% +because we know the probability + + + align:start position:0% +because we know the probability +distribution that the path will end up + + align:start position:0% +distribution that the path will end up + + + align:start position:0% +distribution that the path will end up +at these points. Suppose + + align:start position:0% + + + + align:start position:0% + +that you computed all these values + + align:start position:0% + + + + align:start position:0% + +here then I draw too many 1 2 3 4 5 this + + align:start position:0% +here then I draw too many 1 2 3 4 5 this + + + align:start position:0% +here then I draw too many 1 2 3 4 5 this +1 over 32 probability here 5 choose 1 5 + + align:start position:0% +1 over 32 probability here 5 choose 1 5 + + + align:start position:0% +1 over 32 probability here 5 choose 1 5 +over + + align:start position:0% +over + + + align:start position:0% +over +32 5 choose 2 is 5 4 10 over + + align:start position:0% + + + + align:start position:0% + +32 suppose that some stoastic process + + align:start position:0% +32 suppose that some stoastic process + + + align:start position:0% +32 suppose that some stoastic process +after following this has value one here, + + align:start position:0% +after following this has value one here, + + + align:start position:0% +after following this has value one here, +two here, three here, four, five and six + + align:start position:0% +two here, three here, four, five and six + + + align:start position:0% +two here, three here, four, five and six +here. And + + align:start position:0% +here. And + + + align:start position:0% +here. And +approximately if you take a brown + + align:start position:0% +approximately if you take a brown + + + align:start position:0% +approximately if you take a brown +motion, it will have one with + + align:start position:0% +motion, it will have one with + + + align:start position:0% +motion, it will have one with +probability 1 over 32, two with + + align:start position:0% +probability 1 over 32, two with + + + align:start position:0% +probability 1 over 32, two with +probability 5 over 32 and so on. + + align:start position:0% +probability 5 over 32 and so on. + + + align:start position:0% +probability 5 over 32 and so on. +Okay, maybe I didn't explain that well, + + align:start position:0% +Okay, maybe I didn't explain that well, + + + align:start position:0% +Okay, maybe I didn't explain that well, +but basically tree method just says you + + align:start position:0% +but basically tree method just says you + + + align:start position:0% +but basically tree method just says you +can discretise the outcome of the + + align:start position:0% +can discretise the outcome of the + + + align:start position:0% +can discretise the outcome of the +brownian + + align:start position:0% +brownian + + + align:start position:0% +brownian +motion based on the fact that it's a + + align:start position:0% +motion based on the fact that it's a + + + align:start position:0% +motion based on the fact that it's a +limit of simple random + + align:start position:0% +limit of simple random + + + align:start position:0% +limit of simple random +walk. So just do the exact same method + + align:start position:0% +walk. So just do the exact same method + + + align:start position:0% +walk. So just do the exact same method +for a simple random walk instead of + + align:start position:0% +for a simple random walk instead of + + + align:start position:0% +for a simple random walk instead of +browning motion and then take it to the + + align:start position:0% +browning motion and then take it to the + + + align:start position:0% +browning motion and then take it to the +limit. That's the + + align:start position:0% + + + + align:start position:0% + +principle. + + align:start position:0% +principle. + + + align:start position:0% +principle. +Yeah. But yeah, I don't know what's + + align:start position:0% +Yeah. But yeah, I don't know what's + + + align:start position:0% +Yeah. But yeah, I don't know what's +being used in practice, but it seems + + align:start position:0% +being used in practice, but it seems + + + align:start position:0% +being used in practice, but it seems +like these two are the more important + + align:start position:0% +like these two are the more important + + + align:start position:0% +like these two are the more important +ones. This is more like if you want to + + align:start position:0% +ones. This is more like if you want to + + + align:start position:0% +ones. This is more like if you want to +do it by hand because you can't really + + align:start position:0% +do it by hand because you can't really + + + align:start position:0% +do it by hand because you can't really +do every single possibility that makes + + align:start position:0% +do every single possibility that makes + + + align:start position:0% +do every single possibility that makes +you only a finite + + align:start position:0% +you only a finite + + + align:start position:0% +you only a finite +possibility. So + + align:start position:0% +possibility. So + + + align:start position:0% +possibility. So +any questions? + + align:start position:0% +any questions? + + + align:start position:0% +any questions? +Yeah. So uh here you said we get u by + + align:start position:0% +Yeah. So uh here you said we get u by + + + align:start position:0% +Yeah. So uh here you said we get u by +repeating the experiment we get uh kind + + align:start position:0% +repeating the experiment we get uh kind + + + align:start position:0% +repeating the experiment we get uh kind +of a distribution for x1. Mhm. Uh I was + + align:start position:0% +of a distribution for x1. Mhm. Uh I was + + + align:start position:0% +of a distribution for x1. Mhm. Uh I was +wondering we could also get the + + align:start position:0% +wondering we could also get the + + + align:start position:0% +wondering we could also get the +distribution for not just x1 but also + + align:start position:0% +distribution for not just x1 but also + + + align:start position:0% +distribution for not just x1 but also +for x ih all the intermediate values. + + align:start position:0% +for x ih all the intermediate values. + + + align:start position:0% +for x ih all the intermediate values. +Yeah. Yeah. But the problem is we're + + align:start position:0% +Yeah. Yeah. But the problem is we're + + + align:start position:0% +Yeah. Yeah. But the problem is we're +taking different values of h. H will be + + align:start position:0% +taking different values of h. H will be + + + align:start position:0% +taking different values of h. H will be +smaller and smaller but for those values + + align:start position:0% +smaller and smaller but for those values + + + align:start position:0% +smaller and smaller but for those values +we took Yeah. We will get some + + align:start position:0% +we took Yeah. We will get some + + + align:start position:0% +we took Yeah. We will get some +distribution right. So we might have + + align:start position:0% +distribution right. So we might have + + + align:start position:0% +distribution right. So we might have +distributions for x of t for many + + align:start position:0% +distributions for x of t for many + + + align:start position:0% +distributions for x of t for many +different points. Right. Yeah. Yeah. So + + align:start position:0% +different points. Right. Yeah. Yeah. So + + + align:start position:0% +different points. Right. Yeah. Yeah. So +maybe we could uh + + align:start position:0% + + + + align:start position:0% + +right but one thing you have to be + + align:start position:0% +right but one thing you have to be + + + align:start position:0% +right but one thing you have to be +careful is let's suppose you take h= one + + align:start position:0% +careful is let's suppose you take h= one + + + align:start position:0% +careful is let's suppose you take h= one +over + + align:start position:0% +over + + + align:start position:0% +over +100 then this will give you a pretty + + align:start position:0% +100 then this will give you a pretty + + + align:start position:0% +100 then this will give you a pretty +fairly good approximation for x of one + + align:start position:0% +fairly good approximation for x of one + + + align:start position:0% +fairly good approximation for x of one +but it won't give you a good + + align:start position:0% +but it won't give you a good + + + align:start position:0% +but it won't give you a good +approximation for x of 1 over 50. Yeah. + + align:start position:0% +approximation for x of 1 over 50. Yeah. + + + align:start position:0% +approximation for x of 1 over 50. Yeah. +So probably you can also get + + align:start position:0% +So probably you can also get + + + align:start position:0% +So probably you can also get +distribution where it's so 1 over 3 1 + + align:start position:0% +distribution where it's so 1 over 3 1 + + + align:start position:0% +distribution where it's so 1 over 3 1 +over 4 but at some point the uh + + align:start position:0% +over 4 but at some point the uh + + + align:start position:0% +over 4 but at some point the uh +approximation will be very very + + align:start position:0% +approximation will be very very + + + align:start position:0% +approximation will be very very +bad. So the key is to choose the right h + + align:start position:0% +bad. So the key is to choose the right h + + + align:start position:0% +bad. So the key is to choose the right h +because if you pick h to be too small + + align:start position:0% +because if you pick h to be too small + + + align:start position:0% +because if you pick h to be too small +you'll have have a very good + + align:start position:0% +you'll have have a very good + + + align:start position:0% +you'll have have a very good +approximation to your distribution but + + align:start position:0% +approximation to your distribution but + + + align:start position:0% +approximation to your distribution but +at the same time it'll take too much + + align:start position:0% +at the same time it'll take too much + + + align:start position:0% +at the same time it'll take too much +time to compute it. + + align:start position:0% + + + + align:start position:0% + +So any remarks from the more practical + + align:start position:0% + + + + align:start position:0% + +side? Okay. So that's actually all all I + + align:start position:0% +side? Okay. So that's actually all all I + + + align:start position:0% +side? Okay. So that's actually all all I +wanted to say about stoastic + + align:start position:0% +wanted to say about stoastic + + + align:start position:0% +wanted to say about stoastic +differential equations. Really uh the + + align:start position:0% +differential equations. Really uh the + + + align:start position:0% +differential equations. Really uh the +basic principle is there is such thing + + align:start position:0% +basic principle is there is such thing + + + align:start position:0% +basic principle is there is such thing +called stoastic differential equation. + + align:start position:0% +called stoastic differential equation. + + + align:start position:0% +called stoastic differential equation. +It can be solved but most of the times + + align:start position:0% +It can be solved but most of the times + + + align:start position:0% +It can be solved but most of the times +it won't have a closed form formula. And + + align:start position:0% +it won't have a closed form formula. And + + + align:start position:0% +it won't have a closed form formula. And +if you want to do it numerically here + + align:start position:0% +if you want to do it numerically here + + + align:start position:0% +if you want to do it numerically here +are some possibilities. Okay, but I + + align:start position:0% +are some possibilities. Okay, but I + + + align:start position:0% +are some possibilities. Okay, but I +won't go any further any deeper + + align:start position:0% +won't go any further any deeper + + + align:start position:0% +won't go any further any deeper +inside. So the last meth math lecture I + + align:start position:0% +inside. So the last meth math lecture I + + + align:start position:0% +inside. So the last meth math lecture I +will conclude with heat equation. + + align:start position:0% +will conclude with heat equation. + + + align:start position:0% +will conclude with heat equation. +[Applause] + + align:start position:0% + + + + align:start position:0% + +Yeah, computations of various prices. + + align:start position:0% +Yeah, computations of various prices. + + + align:start position:0% +Yeah, computations of various prices. +Some some of the derivatives are sort of + + align:start position:0% +Some some of the derivatives are sort of + + + align:start position:0% +Some some of the derivatives are sort of +path independent or have path + + align:start position:0% +path independent or have path + + + align:start position:0% +path independent or have path +independent solutions. So that you know + + align:start position:0% +independent solutions. So that you know + + + align:start position:0% +independent solutions. So that you know +you you basically are looking at say the + + align:start position:0% +you you basically are looking at say the + + + align:start position:0% +you you basically are looking at say the +distribution at the terminal value and + + align:start position:0% +distribution at the terminal value and + + + align:start position:0% +distribution at the terminal value and +that determines the price of the + + align:start position:0% +that determines the price of the + + + align:start position:0% +that determines the price of the +derivative. There are you know there are + + align:start position:0% +derivative. There are you know there are + + + align:start position:0% +derivative. There are you know there are +other derivatives where things really + + align:start position:0% +other derivatives where things really + + + align:start position:0% +other derivatives where things really +are path dependent + + align:start position:0% +are path dependent + + + align:start position:0% +are path dependent +um like uh with options with where you + + align:start position:0% +um like uh with options with where you + + + align:start position:0% +um like uh with options with where you +have early exercise possibilities. Um + + align:start position:0% +have early exercise possibilities. Um + + + align:start position:0% +have early exercise possibilities. Um +when do you exercise early or not? then + + align:start position:0% +when do you exercise early or not? then + + + align:start position:0% +when do you exercise early or not? then +the tree methods are really good because + + align:start position:0% +the tree methods are really good because + + + align:start position:0% +the tree methods are really good because +at each element of the tree you can + + align:start position:0% +at each element of the tree you can + + + align:start position:0% +at each element of the tree you can +condition on whatever the path was. So + + align:start position:0% +condition on whatever the path was. So + + + align:start position:0% +condition on whatever the path was. So +um so keep that in mind that when + + align:start position:0% +um so keep that in mind that when + + + align:start position:0% +um so keep that in mind that when +there's path dependence in the problem + + align:start position:0% +there's path dependence in the problem + + + align:start position:0% +there's path dependence in the problem +you'll probably want to use one of these + + align:start position:0% +you'll probably want to use one of these + + + align:start position:0% +you'll probably want to use one of these +methods. Thanks. I know that if you're + + align:start position:0% +methods. Thanks. I know that if you're + + + align:start position:0% +methods. Thanks. I know that if you're +trying to break it down into simple + + align:start position:0% +trying to break it down into simple + + + align:start position:0% +trying to break it down into simple +random walks um you can only + + align:start position:0% +random walks um you can only + + + align:start position:0% +random walks um you can only +use no uh plus minus but if you were to + + align:start position:0% +use no uh plus minus but if you were to + + + align:start position:0% +use no uh plus minus but if you were to +I've heard of people trying to use a + + align:start position:0% +I've heard of people trying to use a + + + align:start position:0% +I've heard of people trying to use a +instead of a binomial tromial tree. Yes. + + align:start position:0% +instead of a binomial tromial tree. Yes. + + + align:start position:0% +instead of a binomial tromial tree. Yes. +Uh so this statement actually is quite a + + align:start position:0% +Uh so this statement actually is quite a + + + align:start position:0% +Uh so this statement actually is quite a +universal statement. Brownian motion is + + align:start position:0% +universal statement. Brownian motion is + + + align:start position:0% +universal statement. Brownian motion is +a limit of many things not just simple + + align:start position:0% +a limit of many things not just simple + + + align:start position:0% +a limit of many things not just simple +random law. For example, if you take + + + align:start position:0% +random law. For example, if you take + + + + align:start position:0% +random law. For example, if you take + +one 0 or minus one and take it to the + + align:start position:0% +one 0 or minus one and take it to the + + + align:start position:0% +one 0 or minus one and take it to the +limit that will also converge to the + + align:start position:0% +limit that will also converge to the + + + align:start position:0% +limit that will also converge to the +simple brownian motion that will be the + + align:start position:0% +simple brownian motion that will be the + + + align:start position:0% +simple brownian motion that will be the +tromial and so on. Yeah. And as Peter + + align:start position:0% +tromial and so on. Yeah. And as Peter + + + align:start position:0% +tromial and so on. Yeah. And as Peter +said, if you're going to use tree method + + align:start position:0% +said, if you're going to use tree method + + + align:start position:0% +said, if you're going to use tree method +to compute something, that will increase + + align:start position:0% +to compute something, that will increase + + + align:start position:0% +to compute something, that will increase +accuracy if you like take more + + align:start position:0% +accuracy if you like take more + + + align:start position:0% +accuracy if you like take more +possibilities at each + + align:start position:0% +possibilities at each + + + align:start position:0% +possibilities at each +step. There's two ways to increase the + + align:start position:0% +step. There's two ways to increase the + + + align:start position:0% +step. There's two ways to increase the +increase the accuracy is take more + + align:start position:0% +increase the accuracy is take more + + + align:start position:0% +increase the accuracy is take more +possibilities at each step or take + + align:start position:0% +possibilities at each step or take + + + align:start position:0% +possibilities at each step or take +smaller time + + align:start position:0% + + + + align:start position:0% + +scales. Okay, so let's move on to the + + align:start position:0% +scales. Okay, so let's move on to the + + + align:start position:0% +scales. Okay, so let's move on to the +final topic, heat equation. + + align:start position:0% + + + + align:start position:0% + +heat equation is not a stoastic + + align:start position:0% +heat equation is not a stoastic + + + align:start position:0% +heat equation is not a stoastic +differential equation. First of + + align:start position:0% +differential equation. First of + + + align:start position:0% +differential equation. First of +all, it's a + + align:start position:0% + + + + align:start position:0% + +PTE. That equation is known as a heat + + align:start position:0% +PTE. That equation is known as a heat + + + align:start position:0% +PTE. That equation is known as a heat +equation. where T is like the time + + align:start position:0% +equation. where T is like the time + + + align:start position:0% +equation. where T is like the time +variable. X is like the space variable. + + align:start position:0% +variable. X is like the space variable. + + + align:start position:0% +variable. X is like the space variable. +And the reason we're interested in in + + align:start position:0% +And the reason we're interested in in + + + align:start position:0% +And the reason we're interested in in +this heat equation in this course is if + + align:start position:0% +this heat equation in this course is if + + + align:start position:0% +this heat equation in this course is if +you came to the previous + + align:start position:0% + + + + align:start position:0% + +lecture the maybe from vessel last + + align:start position:0% +lecture the maybe from vessel last + + + align:start position:0% +lecture the maybe from vessel last +week the brown uh what is it black shows + + align:start position:0% +week the brown uh what is it black shows + + + align:start position:0% +week the brown uh what is it black shows +equation after changing change of + + align:start position:0% +equation after changing change of + + + align:start position:0% +equation after changing change of +variables can be uh reduced to heat + + align:start position:0% +variables can be uh reduced to heat + + + align:start position:0% +variables can be uh reduced to heat +equation. Okay, that's one reason we're + + align:start position:0% +equation. Okay, that's one reason we're + + + align:start position:0% +equation. Okay, that's one reason we're +interested in it. And this is a really + + align:start position:0% +interested in it. And this is a really + + + align:start position:0% +interested in it. And this is a really +really famous equation also in physics. + + align:start position:0% +really famous equation also in physics. + + + align:start position:0% +really famous equation also in physics. +So it was known before lectur's + + align:start position:0% +So it was known before lectur's + + + align:start position:0% +So it was known before lectur's +equation particularly this will can be a + + align:start position:0% +equation particularly this will can be a + + + align:start position:0% +equation particularly this will can be a +model or equations that model this + + align:start position:0% + + + + align:start position:0% + +situation. So you have an infinite + + align:start position:0% +situation. So you have an infinite + + + align:start position:0% +situation. So you have an infinite +bar very uh long and thin. It's + + align:start position:0% +bar very uh long and thin. It's + + + align:start position:0% +bar very uh long and thin. It's +perfectly + + align:start position:0% + + + + align:start position:0% + +insulated. So, heat can only travel uh + + align:start position:0% +insulated. So, heat can only travel uh + + + align:start position:0% +insulated. So, heat can only travel uh +along the + + align:start position:0% +along the + + + align:start position:0% +along the +x-axis. And then at time + + align:start position:0% + + + + align:start position:0% + +z. Okay. At time + + align:start position:0% +z. Okay. At time + + + align:start position:0% +z. Okay. At time +z, you know the heat distribution. + + align:start position:0% + + + + align:start position:0% + +Then this equation tells you the + + align:start position:0% +Then this equation tells you the + + + align:start position:0% +Then this equation tells you the +behavior of how the heat will be + + align:start position:0% +behavior of how the heat will be + + + align:start position:0% +behavior of how the heat will be +distributed at time t. So u of t of + + align:start position:0% +distributed at time t. So u of t of + + + align:start position:0% +distributed at time t. So u of t of +x will be for fixed t will be the + + align:start position:0% +x will be for fixed t will be the + + + align:start position:0% +x will be for fixed t will be the +distribution of the heat over the + + align:start position:0% +distribution of the heat over the + + + align:start position:0% +distribution of the heat over the +x-axis. That's why it's called the heat + + align:start position:0% +x-axis. That's why it's called the heat + + + align:start position:0% +x-axis. That's why it's called the heat +equation. That's where the name comes + + align:start position:0% +equation. That's where the name comes + + + align:start position:0% +equation. That's where the name comes +[Applause] + + align:start position:0% +[Applause] + + + align:start position:0% +[Applause] +from. And this equation is very well + + align:start position:0% +from. And this equation is very well + + + align:start position:0% +from. And this equation is very well +understood. it does have a closed forms + + align:start position:0% +understood. it does have a closed forms + + + align:start position:0% +understood. it does have a closed forms +uh closed form solution and that's what + + align:start position:0% +uh closed form solution and that's what + + + align:start position:0% +uh closed form solution and that's what +I want to talk + + align:start position:0% + + + + align:start position:0% + +about. Okay. So a few observations + + align:start position:0% +about. Okay. So a few observations + + + align:start position:0% +about. Okay. So a few observations +before actually solving + + align:start position:0% + + + + align:start position:0% + +it. Remark + + align:start position:0% + + + + align:start position:0% + +one. If u1 and u2 satisfies heat + + align:start position:0% + + + + align:start position:0% + +equation then u1 plus u2 also + + align:start position:0% +equation then u1 plus u2 also + + + align:start position:0% +equation then u1 plus u2 also +satisfies also + + align:start position:0% + + + + align:start position:0% + +this that's called + + align:start position:0% +this that's called + + + align:start position:0% +this that's called +linearity. Just plug it in and you can + + align:start position:0% +linearity. Just plug it in and you can + + + align:start position:0% +linearity. Just plug it in and you can +figure it out. + + align:start position:0% +figure it out. + + + align:start position:0% +figure it out. +More generally that + + align:start position:0% +More generally that + + + align:start position:0% +More generally that +means if you integrate a family of + + align:start position:0% +means if you integrate a family of + + + align:start position:0% +means if you integrate a family of +functions + + align:start position:0% + + + + align:start position:0% + +ds + + align:start position:0% +ds + + + align:start position:0% +ds +where us all + + align:start position:0% + + + + align:start position:0% + +satisfy + + align:start position:0% +satisfy + + + align:start position:0% +satisfy +star + + align:start position:0% +star + + + align:start position:0% +star +then + + align:start position:0% +then + + + align:start position:0% +then +this also + + align:start position:0% + + + + align:start position:0% + +satisfies + + align:start position:0% +satisfies + + + align:start position:0% +satisfies +star okay as long as you use reasonable + + align:start position:0% +star okay as long as you use reasonable + + + align:start position:0% +star okay as long as you use reasonable +function I'll just assume that we can + + align:start position:0% +function I'll just assume that we can + + + align:start position:0% +function I'll just assume that we can +switch the order of integration and + + align:start position:0% +switch the order of integration and + + + align:start position:0% +switch the order of integration and +differentiation so it's the same thing + + align:start position:0% +differentiation so it's the same thing + + + align:start position:0% +differentiation so it's the same thing +instead of summation I'm taking + + align:start position:0% +instead of summation I'm taking + + + align:start position:0% +instead of summation I'm taking +integration of a lot of + + align:start position:0% +integration of a lot of + + + align:start position:0% +integration of a lot of +solutions + + align:start position:0% +solutions + + + align:start position:0% +solutions +okay and why is that + + align:start position:0% +okay and why is that + + + align:start position:0% +okay and why is that +helpful this is + + align:start position:0% +helpful this is + + + align:start position:0% +helpful this is +helpful because + + align:start position:0% + + + + align:start position:0% + +now it suffices + + align:start position:0% + + + + align:start position:0% + +to + + align:start position:0% +to + + + align:start position:0% +to +solve + + align:start position:0% + + + + align:start position:0% + +for what is it? Initial condition + + align:start position:0% +for what is it? Initial condition + + + align:start position:0% +for what is it? Initial condition +u of t of x equals delta delta + + align:start position:0% +u of t of x equals delta delta + + + align:start position:0% +u of t of x equals delta delta +function of + + align:start position:0% + + + + align:start position:0% + +zero. + + align:start position:0% +zero. + + + align:start position:0% +zero. +Okay, that one is a little bit subtle. + + align:start position:0% +Okay, that one is a little bit subtle. + + + align:start position:0% +Okay, that one is a little bit subtle. +The direct delta function is just it's + + align:start position:0% +The direct delta function is just it's + + + align:start position:0% +The direct delta function is just it's +like an infinite mass at x equals z. + + align:start position:0% +like an infinite mass at x equals z. + + + align:start position:0% +like an infinite mass at x equals z. +It's zero everywhere + + align:start position:0% +It's zero everywhere + + + align:start position:0% +It's zero everywhere +else. And basically in this example, + + align:start position:0% +else. And basically in this example, + + + align:start position:0% +else. And basically in this example, +what you're saying is at time zero, + + align:start position:0% +what you're saying is at time zero, + + + align:start position:0% +what you're saying is at time zero, +you're putting like a massive amount of + + align:start position:0% +you're putting like a massive amount of + + + align:start position:0% +you're putting like a massive amount of +heat at a single point and you're + + align:start position:0% +heat at a single point and you're + + + align:start position:0% +heat at a single point and you're +observing what's going to happen + + align:start position:0% +observing what's going to happen + + + align:start position:0% +observing what's going to happen +afterwards. How this heat will spread + + align:start position:0% +afterwards. How this heat will spread + + + align:start position:0% +afterwards. How this heat will spread +out. If you understand that, you can + + align:start position:0% +out. If you understand that, you can + + + align:start position:0% +out. If you understand that, you can +understand all initial conditions. Why + + align:start position:0% +understand all initial conditions. Why + + + align:start position:0% +understand all initial conditions. Why +is that? + + align:start position:0% + + + + align:start position:0% + +Because if u subs tx uh ux tx + + align:start position:0% +Because if u subs tx uh ux tx + + + align:start position:0% +Because if u subs tx uh ux tx +u0 is such + + align:start position:0% + + + + align:start position:0% + +solution + + align:start position:0% + + + + align:start position:0% + +then integration of let me get it right + + align:start position:0% +then integration of let me get it right + + + align:start position:0% +then integration of let me get it right +u of + + align:start position:0% +u of + + + align:start position:0% +u of +t of s - + + align:start position:0% + + + + align:start position:0% + +X + + align:start position:0% + + + + align:start position:0% + +T is a + + align:start position:0% + + + + align:start position:0% + +solution with initial + + align:start position:0% + + + + align:start position:0% + +condition + + align:start position:0% + + + + align:start position:0% + +X. What is it? + + align:start position:0% + + + + align:start position:0% + +Sorry about that. This is really the + + align:start position:0% +Sorry about that. This is really the + + + align:start position:0% +Sorry about that. This is really the +key. + + align:start position:0% +key. + + + align:start position:0% +key. +If you have a solution to the direct + + align:start position:0% +If you have a solution to the direct + + + align:start position:0% +If you have a solution to the direct +delta solution uh direct delta initial + + align:start position:0% +delta solution uh direct delta initial + + + align:start position:0% +delta solution uh direct delta initial +condition then you can superimpose a lot + + align:start position:0% +condition then you can superimpose a lot + + + align:start position:0% +condition then you can superimpose a lot +of those solutions to obtain a solution + + align:start position:0% +of those solutions to obtain a solution + + + align:start position:0% +of those solutions to obtain a solution +for an arbitrary initial + + align:start position:0% +for an arbitrary initial + + + align:start position:0% +for an arbitrary initial +condition because so this is based on + + align:start position:0% +condition because so this is based on + + + align:start position:0% +condition because so this is based on +that principle because each of them is + + align:start position:0% +that principle because each of them is + + + align:start position:0% +that principle because each of them is +now a solution. If you superose + + align:start position:0% +now a solution. If you superose + + + align:start position:0% +now a solution. If you superose +this then that is a solution and then if + + align:start position:0% +this then that is a solution and then if + + + align:start position:0% +this then that is a solution and then if +you plug it in you figure out that + + align:start position:0% +you plug it in you figure out that + + + align:start position:0% +you plug it in you figure out that +actually it has satisfies this initial + + align:start position:0% + + + + align:start position:0% + +condition. That was my f as a first + + align:start position:0% +condition. That was my f as a first + + + align:start position:0% +condition. That was my f as a first +observation. + + align:start position:0% +observation. + + + align:start position:0% +observation. +Second + + align:start position:0% + + + + align:start position:0% + +observation, second + + align:start position:0% + + + + align:start position:0% + +remark + + align:start position:0% + + + + align:start position:0% + +is for the initial + + align:start position:0% + + + + align:start position:0% + +value. U0x equals the direct delta + + align:start position:0% +value. U0x equals the direct delta + + + align:start position:0% +value. U0x equals the direct delta +function. + + align:start position:0% + + + + align:start position:0% + +you is the + + align:start position:0% + + + + align:start position:0% + +solution is our + + align:start position:0% +solution is our + + + align:start position:0% +solution is our +solution. So we know the solution for + + align:start position:0% +solution. So we know the solution for + + + align:start position:0% +solution. So we know the solution for +the direct delta function. First part we + + align:start position:0% +the direct delta function. First part we + + + align:start position:0% +the direct delta function. First part we +figured out that if we know the solution + + align:start position:0% +figured out that if we know the solution + + + align:start position:0% +figured out that if we know the solution +for the direct delta function and we can + + align:start position:0% +for the direct delta function and we can + + + align:start position:0% +for the direct delta function and we can +solve it for every single initial value + + align:start position:0% +solve it for every single initial value + + + align:start position:0% +solve it for every single initial value +and for the initial value direct delta + + align:start position:0% +and for the initial value direct delta + + + align:start position:0% +and for the initial value direct delta +that is a distribution that's uh that is + + align:start position:0% +that is a distribution that's uh that is + + + align:start position:0% +that is a distribution that's uh that is +the solution that solves the + + align:start position:0% +the solution that solves the + + + align:start position:0% +the solution that solves the +differential equation. So let me say a + + align:start position:0% +differential equation. So let me say a + + + align:start position:0% +differential equation. So let me say a +few words about this equation. Actually + + align:start position:0% +few words about this equation. Actually + + + align:start position:0% +few words about this equation. Actually +one + + align:start position:0% +one + + + align:start position:0% +one +word. Have you seen this equation + + align:start position:0% + + + + align:start position:0% + +before? Right? It's a PDF of normal + + align:start position:0% +before? Right? It's a PDF of normal + + + align:start position:0% +before? Right? It's a PDF of normal +distribution. So what does it mean? It + + align:start position:0% +distribution. So what does it mean? It + + + align:start position:0% +distribution. So what does it mean? It +means in this example if you have a heat + + align:start position:0% +means in this example if you have a heat + + + align:start position:0% +means in this example if you have a heat +traveling along the x-axis perfectly + + align:start position:0% +traveling along the x-axis perfectly + + + align:start position:0% +traveling along the x-axis perfectly +insulated if you put a massive heat at + + align:start position:0% +insulated if you put a massive heat at + + + align:start position:0% +insulated if you put a massive heat at +this zero at one point at time zero then + + align:start position:0% +this zero at one point at time zero then + + + align:start position:0% +this zero at one point at time zero then +at time t your heat will be distributed + + align:start position:0% +at time t your heat will be distributed + + + align:start position:0% +at time t your heat will be distributed +according to the normal distribution. In + + align:start position:0% +according to the normal distribution. In + + + align:start position:0% +according to the normal distribution. In +other words, assume that you have a + + align:start position:0% +other words, assume that you have a + + + align:start position:0% +other words, assume that you have a +bunch of particle. Heat is just a bunch + + align:start position:0% +bunch of particle. Heat is just a bunch + + + align:start position:0% +bunch of particle. Heat is just a bunch +of particles. say millions of particles + + align:start position:0% +of particles. say millions of particles + + + align:start position:0% +of particles. say millions of particles +at a single + + align:start position:0% +at a single + + + align:start position:0% +at a single +point and then at time uh you grab it + + align:start position:0% +point and then at time uh you grab it + + + align:start position:0% +point and then at time uh you grab it +and then time t equals z you release + + align:start position:0% +and then time t equals z you release + + + align:start position:0% +and then time t equals z you release +them then from it's like they're + + align:start position:0% +them then from it's like they're + + + align:start position:0% +them then from it's like they're +distributed now the particle at time t + + align:start position:0% +distributed now the particle at time t + + + align:start position:0% +distributed now the particle at time t +will be distributed according to a + + align:start position:0% +will be distributed according to a + + + align:start position:0% +will be distributed according to a +normal distribution in other words each + + align:start position:0% +normal distribution in other words each + + + align:start position:0% +normal distribution in other words each +particle is like a brownian + + align:start position:0% +particle is like a brownian + + + align:start position:0% +particle is like a brownian +motion so for particle by + + align:start position:0% +motion so for particle by + + + align:start position:0% +motion so for particle by +particle the location of its particle at + + align:start position:0% +particle the location of its particle at + + + align:start position:0% +particle the location of its particle at +and t will be kind of like distributed + + align:start position:0% +and t will be kind of like distributed + + + align:start position:0% +and t will be kind of like distributed +like a brownian motion. So the overall + + align:start position:0% +like a brownian motion. So the overall + + + align:start position:0% +like a brownian motion. So the overall +if you have a massive amount of + + align:start position:0% +if you have a massive amount of + + + align:start position:0% +if you have a massive amount of +particles altogether their distribution + + align:start position:0% +particles altogether their distribution + + + align:start position:0% +particles altogether their distribution +will look like a normal distribution. + + align:start position:0% +will look like a normal distribution. + + + align:start position:0% +will look like a normal distribution. +That's like its + + align:start position:0% +That's like its + + + align:start position:0% +That's like its +content. So that's also one way you see + + align:start position:0% +content. So that's also one way you see + + + align:start position:0% +content. So that's also one way you see +the appearance of a brownian motion + + align:start position:0% +the appearance of a brownian motion + + + align:start position:0% +the appearance of a brownian motion +inside this + + align:start position:0% +inside this + + + align:start position:0% +inside this +equation. Okay, it's like a br bunch of + + align:start position:0% +equation. Okay, it's like a br bunch of + + + align:start position:0% +equation. Okay, it's like a br bunch of +brown motions and happen happening + + align:start position:0% +brown motions and happen happening + + + align:start position:0% +brown motions and happen happening +together at the exact same time. + + align:start position:0% + + + + align:start position:0% + +And + + align:start position:0% +And + + + align:start position:0% +And +now we can just write down the + + align:start position:0% +now we can just write down the + + + align:start position:0% +now we can just write down the +solution. Let me be a little bit more + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +precise. Okay. + + align:start position:0% + + + + align:start position:0% + +for the heat equation delta u by delta + + align:start position:0% + + + + align:start position:0% + +t with initial value + + align:start position:0% + + + + align:start position:0% + +u of 0 x equals some initial value let's + + align:start position:0% +u of 0 x equals some initial value let's + + + align:start position:0% +u of 0 x equals some initial value let's +say v of + + align:start position:0% + + + + align:start position:0% + +x and t greater than equal to zero + + align:start position:0% + + + + align:start position:0% + +The solution + + align:start position:0% + + + + align:start position:0% + +is given + + align:start position:0% + + + + align:start position:0% + +by integration + + align:start position:0% + + + + align:start position:0% + +u at t.x + + align:start position:0% + + + + align:start position:0% + +X is equal + + align:start position:0% + + + + align:start position:0% + +to + + align:start position:0% + + + + align:start position:0% + +Neess. Let me get it right. + + align:start position:0% + + + + align:start position:0% + +x - + + align:start position:0% +x - + + + align:start position:0% +x - +6 that's the + + align:start position:0% + + + + align:start position:0% + +[Applause] + + align:start position:0% + + + + align:start position:0% + +same basically I'm just combining this + + align:start position:0% +same basically I'm just combining this + + + align:start position:0% +same basically I'm just combining this +solution to there plug it in that here + + align:start position:0% +solution to there plug it in that here + + + align:start position:0% +solution to there plug it in that here +you get + + align:start position:0% + + + + align:start position:0% + +So you have an explicit solution no + + align:start position:0% +So you have an explicit solution no + + + align:start position:0% +So you have an explicit solution no +matter what the initial conditions + + align:start position:0% +matter what the initial conditions + + + align:start position:0% +matter what the initial conditions +are. Initial conditions are given as you + + align:start position:0% +are. Initial conditions are given as you + + + align:start position:0% +are. Initial conditions are given as you +can find an explicit solution at time + + align:start position:0% +can find an explicit solution at time + + + align:start position:0% +can find an explicit solution at time +t for all + + align:start position:0% +t for all + + + align:start position:0% +t for all +x. Okay, that means once you uh change + + align:start position:0% +x. Okay, that means once you uh change + + + align:start position:0% +x. Okay, that means once you uh change +the black shells equation into the heat + + align:start position:0% +the black shells equation into the heat + + + align:start position:0% +the black shells equation into the heat +equation, you know you have you now have + + align:start position:0% +equation, you know you have you now have + + + align:start position:0% +equation, you know you have you now have +a closed form solution for + + align:start position:0% + + + + align:start position:0% + +it. In that case, what will happen is + + align:start position:0% +it. In that case, what will happen is + + + align:start position:0% +it. In that case, what will happen is +like the initial it's like a backward + + align:start position:0% +like the initial it's like a backward + + + align:start position:0% +like the initial it's like a backward +heat equation and what will happen is + + align:start position:0% +heat equation and what will happen is + + + align:start position:0% +heat equation and what will happen is +the initial condition you should think + + align:start position:0% +the initial condition you should think + + + align:start position:0% +the initial condition you should think +of as is the final payout function. the + + align:start position:0% +of as is the final payout function. the + + + align:start position:0% +of as is the final payout function. the +final payout function you integrate + + align:start position:0% +final payout function you integrate + + + align:start position:0% +final payout function you integrate +according to this distribution and then + + align:start position:0% +according to this distribution and then + + + align:start position:0% +according to this distribution and then +you get the value at time t equals + + align:start position:0% +you get the value at time t equals + + + align:start position:0% +you get the value at time t equals +z + + align:start position:0% +z + + + align:start position:0% +z +okay the detail like yeah one of the + + align:start position:0% +okay the detail like yeah one of the + + + align:start position:0% +okay the detail like yeah one of the +final project is to actually carry out + + align:start position:0% +final project is to actually carry out + + + align:start position:0% +final project is to actually carry out +all the details so I will stop here + + align:start position:0% +all the details so I will stop here + + + align:start position:0% +all the details so I will stop here +anyway we didn't see how the black + + align:start position:0% +anyway we didn't see how the black + + + align:start position:0% +anyway we didn't see how the black +should equation actually changed into a + + align:start position:0% +should equation actually changed into a + + + align:start position:0% +should equation actually changed into a +heat equation so + + align:start position:0% +heat equation so + + + align:start position:0% +heat equation so +yep if you want to do that project it + + align:start position:0% +yep if you want to do that project it + + + align:start position:0% +yep if you want to do that project it +will be good to have this in and it will + + align:start position:0% +will be good to have this in and it will + + + align:start position:0% +will be good to have this in and it will +help. Any + + align:start position:0% + + + + align:start position:0% + +question? Okay. So, I think that's all I + + align:start position:0% +question? Okay. So, I think that's all I + + + align:start position:0% +question? Okay. So, I think that's all I +have. I think I'll end a little bit + + align:start position:0% +have. I think I'll end a little bit + + + align:start position:0% +have. I think I'll end a little bit +early today. So, that will be the last + + align:start position:0% +early today. So, that will be the last + + + align:start position:0% +early today. So, that will be the last +me math lecture for the semester. From + + align:start position:0% +me math lecture for the semester. From + + + align:start position:0% +me math lecture for the semester. From +now on, you'll only have application + + align:start position:0% +now on, you'll only have application + + + align:start position:0% +now on, you'll only have application +lectures. There are great lectures + + align:start position:0% +lectures. There are great lectures + + + align:start position:0% +lectures. There are great lectures +coming + + align:start position:0% +coming + + + align:start position:0% +coming +up. I hope and I + + align:start position:0% +up. I hope and I + + + align:start position:0% +up. I hope and I +know so yeah, you should come and really + + align:start position:0% +know so yeah, you should come and really + + + align:start position:0% +know so yeah, you should come and really +enjoy. Now you've went through all this + + align:start position:0% +enjoy. Now you've went through all this + + + align:start position:0% +enjoy. Now you've went through all this +hard work. Now, now it's time to enjoy. \ No newline at end of file diff --git a/qg_HT3CjFI4.txt b/qg_HT3CjFI4.txt new file mode 100644 index 0000000000000000000000000000000000000000..1818a2cc3932d1c64db40dcaaf4e61d3dceeff04 --- /dev/null +++ b/qg_HT3CjFI4.txt @@ -0,0 +1,9131 @@ +align:start position:0% + +but before I I I I do that before I get + + align:start position:0% +but before I I I I do that before I get + + + align:start position:0% +but before I I I I do that before I get +into the islm model um let me spend a + + align:start position:0% +into the islm model um let me spend a + + + align:start position:0% +into the islm model um let me spend a +little time telling you what is going on + + align:start position:0% +little time telling you what is going on + + + align:start position:0% +little time telling you what is going on +uh in the US economy and + + align:start position:0% +uh in the US economy and + + + align:start position:0% +uh in the US economy and +as as this will relate to the kind of + + align:start position:0% +as as this will relate to the kind of + + + align:start position:0% +as as this will relate to the kind of +things I will discuss later in the in + + align:start position:0% +things I will discuss later in the in + + + align:start position:0% +things I will discuss later in the in +this lecture so what you see there is is + + align:start position:0% +this lecture so what you see there is is + + + align:start position:0% +this lecture so what you see there is is +the path of net worth so wealth + + align:start position:0% +the path of net worth so wealth + + + align:start position:0% +the path of net worth so wealth +essentially of households and nonprofit + + align:start position:0% +essentially of households and nonprofit + + + align:start position:0% +essentially of households and nonprofit +organizations households primarily in + + align:start position:0% +organizations households primarily in + + + align:start position:0% +organizations households primarily in +the US and what you can see is that you + + align:start position:0% +the US and what you can see is that you + + + align:start position:0% +the US and what you can see is that you +know there's a more or less steady Trend + + align:start position:0% +know there's a more or less steady Trend + + + align:start position:0% +know there's a more or less steady Trend +obviously in recessions net wealth tends + + align:start position:0% +obviously in recessions net wealth tends + + + align:start position:0% +obviously in recessions net wealth tends +to declin ER and it certainly early on + + align:start position:0% +to declin ER and it certainly early on + + + align:start position:0% +to declin ER and it certainly early on +in the covid recession it declined very + + align:start position:0% +in the covid recession it declined very + + + align:start position:0% +in the covid recession it declined very +dramatically because the price price of + + align:start position:0% +dramatically because the price price of + + + align:start position:0% +dramatically because the price price of +equity the price of houses everything + + align:start position:0% +equity the price of houses everything + + + align:start position:0% +equity the price of houses everything +decline with the initial shock but what + + align:start position:0% +decline with the initial shock but what + + + align:start position:0% +decline with the initial shock but what +you see after that is a dramatic rise in + + align:start position:0% +you see after that is a dramatic rise in + + + align:start position:0% +you see after that is a dramatic rise in +wealth in the US and all around the + + align:start position:0% +wealth in the US and all around the + + + align:start position:0% +wealth in the US and all around the +world but particularly in the US and and + + align:start position:0% +world but particularly in the US and and + + + align:start position:0% +world but particularly in the US and and +what is behind that well there are two + + align:start position:0% +what is behind that well there are two + + + align:start position:0% +what is behind that well there are two +things are behind that but the main one + + align:start position:0% +things are behind that but the main one + + + align:start position:0% +things are behind that but the main one +is asset prices you know you have + + align:start position:0% +is asset prices you know you have + + + align:start position:0% +is asset prices you know you have +massive rallies in the equity Market the + + align:start position:0% +massive rallies in the equity Market the + + + align:start position:0% +massive rallies in the equity Market the +price of houses sort of skyrocketed + + align:start position:0% +price of houses sort of skyrocketed + + + align:start position:0% +price of houses sort of skyrocketed +everywhere and so on last year 2022 was + + align:start position:0% +everywhere and so on last year 2022 was + + + align:start position:0% +everywhere and so on last year 2022 was +a bad year for for asset values the + + align:start position:0% +a bad year for for asset values the + + + align:start position:0% +a bad year for for asset values the +equity Market declined pretty sharply in + + align:start position:0% +equity Market declined pretty sharply in + + + align:start position:0% +equity Market declined pretty sharply in +the US but it's still I mean it's a + + align:start position:0% +the US but it's still I mean it's a + + + align:start position:0% +the US but it's still I mean it's a +small decline relative to the big build + + align:start position:0% +small decline relative to the big build + + + align:start position:0% +small decline relative to the big build +up on wealth + + align:start position:0% +up on wealth + + + align:start position:0% +up on wealth +now why do I do you think that in this + + align:start position:0% +now why do I do you think that in this + + + align:start position:0% +now why do I do you think that in this +course I would be talking about this at + + align:start position:0% +course I would be talking about this at + + + align:start position:0% +course I would be talking about this at +this + + align:start position:0% +this + + + align:start position:0% +this +point what happens what do remember + + align:start position:0% +point what happens what do remember + + + align:start position:0% +point what happens what do remember +we're we're in this part of the course + + align:start position:0% +we're we're in this part of the course + + + align:start position:0% +we're we're in this part of the course +we're trying to come up with a model of + + align:start position:0% +we're trying to come up with a model of + + + align:start position:0% +we're trying to come up with a model of +aggregate demand and then how aggre + + align:start position:0% +aggregate demand and then how aggre + + + align:start position:0% +aggregate demand and then how aggre +demand reacts to policy that's the name + + align:start position:0% +demand reacts to policy that's the name + + + align:start position:0% +demand reacts to policy that's the name +of the game in this part of the course + + align:start position:0% +of the game in this part of the course + + + align:start position:0% +of the game in this part of the course +so if I tell you that wealth increase a + + align:start position:0% +so if I tell you that wealth increase a + + + align:start position:0% +so if I tell you that wealth increase a +lot why do you think I'm telling you + + align:start position:0% + + + + align:start position:0% + +that aggregate demand consumers feel + + align:start position:0% +that aggregate demand consumers feel + + + align:start position:0% +that aggregate demand consumers feel +rich they will tend to consume more that + + align:start position:0% +rich they will tend to consume more that + + + align:start position:0% +rich they will tend to consume more that +will increase aggregate demand so the + + align:start position:0% +will increase aggregate demand so the + + + align:start position:0% +will increase aggregate demand so the +point I'm highlighting to here is that + + align:start position:0% +point I'm highlighting to here is that + + + align:start position:0% +point I'm highlighting to here is that +there's a big force behind increasing + + align:start position:0% +there's a big force behind increasing + + + align:start position:0% +there's a big force behind increasing +aggregate demand which is consumers feel + + align:start position:0% +aggregate demand which is consumers feel + + + align:start position:0% +aggregate demand which is consumers feel +richer by the way something similar is + + align:start position:0% +richer by the way something similar is + + + align:start position:0% +richer by the way something similar is +happening in corporations and investment + + align:start position:0% +happening in corporations and investment + + + align:start position:0% +happening in corporations and investment +is also pretty high because of that real + + align:start position:0% +is also pretty high because of that real + + + align:start position:0% +is also pretty high because of that real +investment the other source of of of of + + align:start position:0% +investment the other source of of of of + + + align:start position:0% +investment the other source of of of of +increasing wealth which is not as + + align:start position:0% +increasing wealth which is not as + + + align:start position:0% +increasing wealth which is not as +dramatic as the previous one but is very + + align:start position:0% +dramatic as the previous one but is very + + + align:start position:0% +dramatic as the previous one but is very +important especially in lower income + + align:start position:0% +important especially in lower income + + + align:start position:0% +important especially in lower income +segments of the population which tend to + + align:start position:0% +segments of the population which tend to + + + align:start position:0% +segments of the population which tend to +have a higher propensity to consume is + + align:start position:0% +have a higher propensity to consume is + + + align:start position:0% +have a higher propensity to consume is +that ER incomes did not decline a lot + + align:start position:0% +that ER incomes did not decline a lot + + + align:start position:0% +that ER incomes did not decline a lot +during during + + align:start position:0% +during during + + + align:start position:0% +during during +covid and in some cases they even + + align:start position:0% +covid and in some cases they even + + + align:start position:0% +covid and in some cases they even +increased because of the large transfers + + align:start position:0% +increased because of the large transfers + + + align:start position:0% +increased because of the large transfers +that we saw from the government to + + align:start position:0% +that we saw from the government to + + + align:start position:0% +that we saw from the government to +individual households especially lower + + align:start position:0% +individual households especially lower + + + align:start position:0% +individual households especially lower +income households and at the same time + + align:start position:0% +income households and at the same time + + + align:start position:0% +income households and at the same time +there wasn't much to spend + + align:start position:0% +there wasn't much to spend + + + align:start position:0% +there wasn't much to spend +on so that meant that the saving rate + + align:start position:0% +on so that meant that the saving rate + + + align:start position:0% +on so that meant that the saving rate +also went up a lot in the US during the + + align:start position:0% +also went up a lot in the US during the + + + align:start position:0% +also went up a lot in the US during the +covid recession okay so people save a + + align:start position:0% +covid recession okay so people save a + + + align:start position:0% +covid recession okay so people save a +lot more that's sort of the average + + align:start position:0% +lot more that's sort of the average + + + align:start position:0% +lot more that's sort of the average +saving of household saies you know this + + align:start position:0% +saving of household saies you know this + + + align:start position:0% +saving of household saies you know this +is by quarter I think no by monthly but + + align:start position:0% +is by quarter I think no by monthly but + + + align:start position:0% +is by quarter I think no by monthly but +that's what we saw in the past look at + + align:start position:0% +that's what we saw in the past look at + + + align:start position:0% +that's what we saw in the past look at +during the covid recession people save a + + align:start position:0% +during the covid recession people save a + + + align:start position:0% +during the covid recession people save a +lot + + align:start position:0% +lot + + + align:start position:0% +lot +more and what you're seeing today is + + align:start position:0% +more and what you're seeing today is + + + align:start position:0% +more and what you're seeing today is +obviously they save a lot more that's + + align:start position:0% +obviously they save a lot more that's + + + align:start position:0% +obviously they save a lot more that's +part of the increasing net we worth is + + align:start position:0% +part of the increasing net we worth is + + + align:start position:0% +part of the increasing net we worth is +is due to this it's small relative to + + align:start position:0% +is due to this it's small relative to + + + align:start position:0% +is due to this it's small relative to +the amount of wealth we saw increased + + align:start position:0% +the amount of wealth we saw increased + + + align:start position:0% +the amount of wealth we saw increased +but but this was about this excess + + align:start position:0% +but but this was about this excess + + + align:start position:0% +but but this was about this excess +saving amounted to about 2.7 2.8 + + align:start position:0% +saving amounted to about 2.7 2.8 + + + align:start position:0% +saving amounted to about 2.7 2.8 +trillion dollar so you get a sense of + + align:start position:0% +trillion dollar so you get a sense of + + + align:start position:0% +trillion dollar so you get a sense of +the order of magnitude and what we is + + align:start position:0% +the order of magnitude and what we is + + + align:start position:0% +the order of magnitude and what we is +happening now is that people are + + align:start position:0% +happening now is that people are + + + align:start position:0% +happening now is that people are +dissaving so now people are saving less + + align:start position:0% +dissaving so now people are saving less + + + align:start position:0% +dissaving so now people are saving less +than they used to because now they have + + align:start position:0% +than they used to because now they have + + + align:start position:0% +than they used to because now they have +opportunity to spend their stuff on okay + + align:start position:0% +opportunity to spend their stuff on okay + + + align:start position:0% +opportunity to spend their stuff on okay +and so that's you see massive demand for + + align:start position:0% +and so that's you see massive demand for + + + align:start position:0% +and so that's you see massive demand for +travel massive demand for restant hotels + + align:start position:0% +travel massive demand for restant hotels + + + align:start position:0% +travel massive demand for restant hotels +and stuff like that well that's has a + + align:start position:0% +and stuff like that well that's has a + + + align:start position:0% +and stuff like that well that's has a +lot to do with people had the money to + + align:start position:0% +lot to do with people had the money to + + + align:start position:0% +lot to do with people had the money to +do it they hadn't been able to do it for + + align:start position:0% +do it they hadn't been able to do it for + + + align:start position:0% +do it they hadn't been able to do it for +a while so now they're doing a lot of + + align:start position:0% +a while so now they're doing a lot of + + + align:start position:0% +a while so now they're doing a lot of +that why would I be telling you this now + + align:start position:0% +that why would I be telling you this now + + + align:start position:0% +that why would I be telling you this now +in the course in it is part of the + + align:start position:0% +in the course in it is part of the + + + align:start position:0% +in the course in it is part of the +course for the same reason I told you + + align:start position:0% +course for the same reason I told you + + + align:start position:0% +course for the same reason I told you +that net worth went a lot I mean people + + align:start position:0% +that net worth went a lot I mean people + + + align:start position:0% +that net worth went a lot I mean people +have the savings and they're really + + align:start position:0% +have the savings and they're really + + + align:start position:0% +have the savings and they're really +willing to spend it that puts lots of + + align:start position:0% +willing to spend it that puts lots of + + + align:start position:0% +willing to spend it that puts lots of +upward pressure on our great demand + + align:start position:0% +upward pressure on our great demand + + + align:start position:0% +upward pressure on our great demand +okay these pictures capture more or less + + align:start position:0% +okay these pictures capture more or less + + + align:start position:0% +okay these pictures capture more or less +the same this is captures very much much + + align:start position:0% +the same this is captures very much much + + + align:start position:0% +the same this is captures very much much +what I said in the previous slide you + + align:start position:0% +what I said in the previous slide you + + + align:start position:0% +what I said in the previous slide you +see the personal saving rate that's the + + align:start position:0% +see the personal saving rate that's the + + + align:start position:0% +see the personal saving rate that's the +average I don't remember over oh seveny + + align:start position:0% +average I don't remember over oh seveny + + + align:start position:0% +average I don't remember over oh seveny +year average and you see what happened + + align:start position:0% +year average and you see what happened + + + align:start position:0% +year average and you see what happened +during covid big spike in the saving + + align:start position:0% +during covid big spike in the saving + + + align:start position:0% +during covid big spike in the saving +rate and now big big decline in the + + align:start position:0% +rate and now big big decline in the + + + align:start position:0% +rate and now big big decline in the +saving rate where the saving rate is + + align:start position:0% +saving rate where the saving rate is + + + align:start position:0% +saving rate where the saving rate is +much lower than what normally is and + + align:start position:0% +much lower than what normally is and + + + align:start position:0% +much lower than what normally is and +remember the saving rate is is your + + align:start position:0% +remember the saving rate is is your + + + align:start position:0% +remember the saving rate is is your +income minus your consumption so if + + align:start position:0% +income minus your consumption so if + + + align:start position:0% +income minus your consumption so if +you're saving less you're consuming more + + align:start position:0% +you're saving less you're consuming more + + + align:start position:0% +you're saving less you're consuming more +relative to your income no that's that's + + align:start position:0% +relative to your income no that's that's + + + align:start position:0% +relative to your income no that's that's +the way it + + align:start position:0% +the way it + + + align:start position:0% +the way it +works obviously there's lots of + + align:start position:0% +works obviously there's lots of + + + align:start position:0% +works obviously there's lots of +heterogeneity some people made a lot of + + align:start position:0% +heterogeneity some people made a lot of + + + align:start position:0% +heterogeneity some people made a lot of +money some people didn't make a lot of + + align:start position:0% +money some people didn't make a lot of + + + align:start position:0% +money some people didn't make a lot of +money during covid H some people Save A + + align:start position:0% +money during covid H some people Save A + + + align:start position:0% +money during covid H some people Save A +Lot some people didn't save a lot and + + align:start position:0% +Lot some people didn't save a lot and + + + align:start position:0% +Lot some people didn't save a lot and +and and and in fact we do know that that + + align:start position:0% +and and and in fact we do know that that + + + align:start position:0% +and and and in fact we do know that that +sort of on the lower income segments a + + align:start position:0% +sort of on the lower income segments a + + + align:start position:0% +sort of on the lower income segments a +lot of the excess saving is already gone + + align:start position:0% +lot of the excess saving is already gone + + + align:start position:0% +lot of the excess saving is already gone +I mean accumulated early on but they + + align:start position:0% +I mean accumulated early on but they + + + align:start position:0% +I mean accumulated early on but they +spent it also much + + align:start position:0% +spent it also much + + + align:start position:0% +spent it also much +earlier um so but what you're beginning + + align:start position:0% +earlier um so but what you're beginning + + + align:start position:0% +earlier um so but what you're beginning +to see in some of those segments is even + + align:start position:0% +to see in some of those segments is even + + + align:start position:0% +to see in some of those segments is even +though the don't have excess savings + + align:start position:0% +though the don't have excess savings + + + align:start position:0% +though the don't have excess savings +they're borrowing a lot so now you see + + align:start position:0% +they're borrowing a lot so now you see + + + align:start position:0% +they're borrowing a lot so now you see +credit card borrowing which had declined + + align:start position:0% +credit card borrowing which had declined + + + align:start position:0% +credit card borrowing which had declined +a lot and now has increased quite a bit + + align:start position:0% +a lot and now has increased quite a bit + + + align:start position:0% +a lot and now has increased quite a bit +and again what do you borrow for well + + align:start position:0% +and again what do you borrow for well + + + align:start position:0% +and again what do you borrow for well +for consumption so that also + + align:start position:0% +for consumption so that also + + + align:start position:0% +for consumption so that also +funds additional consumption so for all + + align:start position:0% +funds additional consumption so for all + + + align:start position:0% +funds additional consumption so for all +these reasons in this Mo at this moment + + align:start position:0% +these reasons in this Mo at this moment + + + align:start position:0% +these reasons in this Mo at this moment +the US economy and many economies around + + align:start position:0% +the US economy and many economies around + + + align:start position:0% +the US economy and many economies around +the world are so what we call + + align:start position:0% +the world are so what we call + + + align:start position:0% +the world are so what we call +overheating there a lot of demand for + + align:start position:0% +overheating there a lot of demand for + + + align:start position:0% +overheating there a lot of demand for +the for the production that capacity of + + align:start position:0% +the for the production that capacity of + + + align:start position:0% +the for the production that capacity of +the economy and that translates the the + + align:start position:0% +the economy and that translates the the + + + align:start position:0% +the economy and that translates the the +problem say well what's wrong with that + + align:start position:0% +problem say well what's wrong with that + + + align:start position:0% +problem say well what's wrong with that +well the problem is something you don't + + align:start position:0% +well the problem is something you don't + + + align:start position:0% +well the problem is something you don't +understand at this part of the course + + align:start position:0% +understand at this part of the course + + + align:start position:0% +understand at this part of the course +you understand but you don't have a + + align:start position:0% +you understand but you don't have a + + + align:start position:0% +you understand but you don't have a +model for but you will have six Le six + + align:start position:0% +model for but you will have six Le six + + + align:start position:0% +model for but you will have six Le six +lectur more or less from now is that + + align:start position:0% +lectur more or less from now is that + + + align:start position:0% +lectur more or less from now is that +that leads to high inflation you don't + + align:start position:0% +that leads to high inflation you don't + + + align:start position:0% +that leads to high inflation you don't +know that but intuition tells you that + + align:start position:0% +know that but intuition tells you that + + + align:start position:0% +know that but intuition tells you that +is a lot of demand relative to supply + + align:start position:0% +is a lot of demand relative to supply + + + align:start position:0% +is a lot of demand relative to supply +well prices tend to go up this that + + align:start position:0% +well prices tend to go up this that + + + align:start position:0% +well prices tend to go up this that +happens in micro and it also happens in + + align:start position:0% +happens in micro and it also happens in + + + align:start position:0% +happens in micro and it also happens in +macro we'll learn that later but in any + + align:start position:0% +macro we'll learn that later but in any + + + align:start position:0% +macro we'll learn that later but in any +event as a result of this the US economy + + align:start position:0% +event as a result of this the US economy + + + align:start position:0% +event as a result of this the US economy +is overheating and therefore monetary + + align:start position:0% +is overheating and therefore monetary + + + align:start position:0% +is overheating and therefore monetary +policy has been very contractionary the + + align:start position:0% +policy has been very contractionary the + + + align:start position:0% +policy has been very contractionary the +FED has been tightening interest rate to + + align:start position:0% +FED has been tightening interest rate to + + + align:start position:0% +FED has been tightening interest rate to +cool down the economy so how does that + + align:start position:0% +cool down the economy so how does that + + + align:start position:0% +cool down the economy so how does that +happen well that's what the kind of + + align:start position:0% +happen well that's what the kind of + + + align:start position:0% +happen well that's what the kind of +things that we can answer with the islm + + align:start position:0% +things that we can answer with the islm + + + align:start position:0% +things that we can answer with the islm +model okay so the FED is very islm like + + align:start position:0% +model okay so the FED is very islm like + + + align:start position:0% +model okay so the FED is very islm like +I mean that's the way they think the + + align:start position:0% +I mean that's the way they think the + + + align:start position:0% +I mean that's the way they think the +model is richer they have more equations + + align:start position:0% +model is richer they have more equations + + + align:start position:0% +model is richer they have more equations +and so on but they are thinking in terms + + align:start position:0% +and so on but they are thinking in terms + + + align:start position:0% +and so on but they are thinking in terms +of the mechanism that we're about to + + align:start position:0% +of the mechanism that we're about to + + + align:start position:0% +of the mechanism that we're about to +sort of summarize in the eslm mod okay + + align:start position:0% +sort of summarize in the eslm mod okay + + + align:start position:0% +sort of summarize in the eslm mod okay +so if you have an economy that has this + + align:start position:0% +so if you have an economy that has this + + + align:start position:0% +so if you have an economy that has this +problem and you are in the Central Bank + + align:start position:0% +problem and you are in the Central Bank + + + align:start position:0% +problem and you are in the Central Bank +you need to use monetary policy well to + + align:start position:0% +you need to use monetary policy well to + + + align:start position:0% +you need to use monetary policy well to +understand how the thing works you need + + align:start position:0% +understand how the thing works you need + + + align:start position:0% +understand how the thing works you need +the eslm model that's a starting point + + align:start position:0% +the eslm model that's a starting point + + + align:start position:0% +the eslm model that's a starting point +then you can add bells and whistles but + + align:start position:0% +then you can add bells and whistles but + + + align:start position:0% +then you can add bells and whistles but +your starting point is the model we're + + align:start position:0% +your starting point is the model we're + + + align:start position:0% +your starting point is the model we're +about to see anyway so so what you see + + align:start position:0% +about to see anyway so so what you see + + + align:start position:0% +about to see anyway so so what you see +is what I was saying is that all that + + align:start position:0% +is what I was saying is that all that + + + align:start position:0% +is what I was saying is that all that +wealth all that excess saving all that + + align:start position:0% +wealth all that excess saving all that + + + align:start position:0% +wealth all that excess saving all that +pent up demand if you will led to lots + + align:start position:0% +pent up demand if you will led to lots + + + align:start position:0% +pent up demand if you will led to lots +of H led to a very an economy it's + + align:start position:0% +of H led to a very an economy it's + + + align:start position:0% +of H led to a very an economy it's +overheating and you can see here what + + align:start position:0% +overheating and you can see here what + + + align:start position:0% +overheating and you can see here what +happened I disentangle between a + + align:start position:0% +happened I disentangle between a + + + align:start position:0% +happened I disentangle between a +consumption of goods and consumption of + + align:start position:0% +consumption of goods and consumption of + + + align:start position:0% +consumption of goods and consumption of +services you consumption of servic is + + align:start position:0% +services you consumption of servic is + + + align:start position:0% +services you consumption of servic is +about two third of consumption remember + + align:start position:0% +about two third of consumption remember + + + align:start position:0% +about two third of consumption remember +we talk about that and goods is about + + align:start position:0% +we talk about that and goods is about + + + align:start position:0% +we talk about that and goods is about +one3 what happens is is in the scales + + align:start position:0% +one3 what happens is is in the scales + + + align:start position:0% +one3 what happens is is in the scales +are different noce this is for goods + + align:start position:0% +are different noce this is for goods + + + align:start position:0% +are different noce this is for goods +this that's for for services but what + + align:start position:0% +this that's for for services but what + + + align:start position:0% +this that's for for services but what +you what you see here is that you know + + align:start position:0% +you what you see here is that you know + + + align:start position:0% +you what you see here is that you know +that was the trend so consumption in + + align:start position:0% +that was the trend so consumption in + + + align:start position:0% +that was the trend so consumption in +Services was growing at a steady Pace + + align:start position:0% +Services was growing at a steady Pace + + + align:start position:0% +Services was growing at a steady Pace +then covid came and collapsed I mean you + + align:start position:0% +then covid came and collapsed I mean you + + + align:start position:0% +then covid came and collapsed I mean you +couldn't go to restaurant you couldn't + + align:start position:0% +couldn't go to restaurant you couldn't + + + align:start position:0% +couldn't go to restaurant you couldn't +travel you couldn't do anything so + + align:start position:0% +travel you couldn't do anything so + + + align:start position:0% +travel you couldn't do anything so +consumption in Services collapsed and + + align:start position:0% +consumption in Services collapsed and + + + align:start position:0% +consumption in Services collapsed and +now has been recovering and and and and + + align:start position:0% +now has been recovering and and and and + + + align:start position:0% +now has been recovering and and and and +that recovery pick up pace last year + + align:start position:0% +that recovery pick up pace last year + + + align:start position:0% +that recovery pick up pace last year +actually 2021 already pick up pace and + + align:start position:0% +actually 2021 already pick up pace and + + + align:start position:0% +actually 2021 already pick up pace and +by now we're above the trend okay so + + align:start position:0% +by now we're above the trend okay so + + + align:start position:0% +by now we're above the trend okay so +service consumption that collapsed + + align:start position:0% +service consumption that collapsed + + + align:start position:0% +service consumption that collapsed +during covid now has fully + + align:start position:0% +during covid now has fully + + + align:start position:0% +during covid now has fully +recovered while at the same time the + + align:start position:0% +recovered while at the same time the + + + align:start position:0% +recovered while at the same time the +capacity to produce in the service + + align:start position:0% +capacity to produce in the service + + + align:start position:0% +capacity to produce in the service +sector hasn't recovered equally but that + + align:start position:0% +sector hasn't recovered equally but that + + + align:start position:0% +sector hasn't recovered equally but that +and we'll get that to that after quiz + + align:start position:0% +and we'll get that to that after quiz + + + align:start position:0% +and we'll get that to that after quiz +one what happens to Goods consumption + + align:start position:0% +one what happens to Goods consumption + + + align:start position:0% +one what happens to Goods consumption +well also initially collaps but then + + align:start position:0% +well also initially collaps but then + + + align:start position:0% +well also initially collaps but then +well you know people were Bor at home + + align:start position:0% +well you know people were Bor at home + + + align:start position:0% +well you know people were Bor at home +they couldn't do anything they bought + + align:start position:0% +they couldn't do anything they bought + + + align:start position:0% +they couldn't do anything they bought +lots of gadgets and and stuff like that + + align:start position:0% +lots of gadgets and and stuff like that + + + align:start position:0% +lots of gadgets and and stuff like that +so Goods consumption went up very + + align:start position:0% +so Goods consumption went up very + + + align:start position:0% +so Goods consumption went up very +sharply during covid way above the trend + + align:start position:0% +sharply during covid way above the trend + + + align:start position:0% +sharply during covid way above the trend +you see there's covid collapse and then + + align:start position:0% +you see there's covid collapse and then + + + align:start position:0% +you see there's covid collapse and then +people began to buy all sort of gadgets + + align:start position:0% +people began to buy all sort of gadgets + + + align:start position:0% +people began to buy all sort of gadgets +okay and so now it's slowing down but + + align:start position:0% +okay and so now it's slowing down but + + + align:start position:0% +okay and so now it's slowing down but +still if you look rela to Trend + + align:start position:0% +still if you look rela to Trend + + + align:start position:0% +still if you look rela to Trend +consumption of goods is way above what + + align:start position:0% +consumption of goods is way above what + + + align:start position:0% +consumption of goods is way above what +would have been in the absence of this + + align:start position:0% +would have been in the absence of this + + + align:start position:0% +would have been in the absence of this +episode so the sum of the two things + + align:start position:0% +episode so the sum of the two things + + + align:start position:0% +episode so the sum of the two things +tells you that you have an economy with + + align:start position:0% +tells you that you have an economy with + + + align:start position:0% +tells you that you have an economy with +a lot of consumption and that and that + + align:start position:0% +a lot of consumption and that and that + + + align:start position:0% +a lot of consumption and that and that +at this moment the FED wants to cool + + align:start position:0% +at this moment the FED wants to cool + + + align:start position:0% +at this moment the FED wants to cool +down okay it's too much for the economy + + align:start position:0% +down okay it's too much for the economy + + + align:start position:0% +down okay it's too much for the economy +to take so the FED wants to cool it down + + align:start position:0% +to take so the FED wants to cool it down + + + align:start position:0% +to take so the FED wants to cool it down +and and we're going to see how how you + + align:start position:0% +and and we're going to see how how you + + + align:start position:0% +and and we're going to see how how you +do + + align:start position:0% +do + + + align:start position:0% +do +that okay so now let's get into into + + align:start position:0% +that okay so now let's get into into + + + align:start position:0% +that okay so now let's get into into +this set of lectures and please please + + align:start position:0% +this set of lectures and please please + + + align:start position:0% +this set of lectures and please please +stop if there's anything that is unclear + + align:start position:0% +stop if there's anything that is unclear + + + align:start position:0% +stop if there's anything that is unclear +because as I said this is probably if IA + + align:start position:0% +because as I said this is probably if IA + + + align:start position:0% +because as I said this is probably if IA +of the summer you have forgotten + + align:start position:0% +of the summer you have forgotten + + + align:start position:0% +of the summer you have forgotten +everything you have learned this course + + align:start position:0% +everything you have learned this course + + + align:start position:0% +everything you have learned this course +but you remember these two lectures well + + align:start position:0% +but you remember these two lectures well + + + align:start position:0% +but you remember these two lectures well +I'll be happy okay so so stop it if you + + align:start position:0% +I'll be happy okay so so stop it if you + + + align:start position:0% +I'll be happy okay so so stop it if you +do in fact I I normally I I I have + + align:start position:0% +do in fact I I normally I I I have + + + align:start position:0% +do in fact I I normally I I I have +taught this lecture in one I I decided + + align:start position:0% +taught this lecture in one I I decided + + + align:start position:0% +taught this lecture in one I I decided +to try to slow it down as much as I can + + align:start position:0% +to try to slow it down as much as I can + + + align:start position:0% +to try to slow it down as much as I can +because again I think it's particularly + + align:start position:0% +because again I think it's particularly + + + align:start position:0% +because again I think it's particularly +important for this course and for your + + align:start position:0% +important for this course and for your + + + align:start position:0% +important for this course and for your +stock of knowledge + + align:start position:0% +stock of knowledge + + + align:start position:0% +stock of knowledge +so so one of the thing the main things + + align:start position:0% +so so one of the thing the main things + + + align:start position:0% +so so one of the thing the main things +we're going to be able to do with this + + align:start position:0% +we're going to be able to do with this + + + align:start position:0% +we're going to be able to do with this +small been saying is we're going to be + + align:start position:0% +small been saying is we're going to be + + + align:start position:0% +small been saying is we're going to be +able to discuss the main macroeconomic + + align:start position:0% +able to discuss the main macroeconomic + + + align:start position:0% +able to discuss the main macroeconomic +policy tools which are monetary policy + + align:start position:0% +policy tools which are monetary policy + + + align:start position:0% +policy tools which are monetary policy +monetary policies is the main antic + + align:start position:0% +monetary policies is the main antic + + + align:start position:0% +monetary policies is the main antic +cyclical pool tool but we're also going + + align:start position:0% +cyclical pool tool but we're also going + + + align:start position:0% +cyclical pool tool but we're also going +to be able to understand fiscal policy + + align:start position:0% +to be able to understand fiscal policy + + + align:start position:0% +to be able to understand fiscal policy +and fiscal policy is not exactly + + align:start position:0% +and fiscal policy is not exactly + + + align:start position:0% +and fiscal policy is not exactly +equivalent to monetary policy it works + + align:start position:0% +equivalent to monetary policy it works + + + align:start position:0% +equivalent to monetary policy it works +through different mechanisms allows you + + align:start position:0% +through different mechanisms allows you + + + align:start position:0% +through different mechanisms allows you +to do things that are more targeted + + align:start position:0% +to do things that are more targeted + + + align:start position:0% +to do things that are more targeted +transfer resources to a specific group + + align:start position:0% +transfer resources to a specific group + + + align:start position:0% +transfer resources to a specific group +of people and so on ER and sometimes + + align:start position:0% +of people and so on ER and sometimes + + + align:start position:0% +of people and so on ER and sometimes +monetary policy is just not enough and + + align:start position:0% +monetary policy is just not enough and + + + align:start position:0% +monetary policy is just not enough and +the covid-19 initial recession was + + align:start position:0% +the covid-19 initial recession was + + + align:start position:0% +the covid-19 initial recession was +clearly a case of that and you had to go + + align:start position:0% +clearly a case of that and you had to go + + + align:start position:0% +clearly a case of that and you had to go +all in and and and we'll see what what + + align:start position:0% +all in and and and we'll see what what + + + align:start position:0% +all in and and and we'll see what what +what we did there it was pretty dramatic + + align:start position:0% +what we did there it was pretty dramatic + + + align:start position:0% +what we did there it was pretty dramatic +as an intervention I think that's the + + align:start position:0% +as an intervention I think that's the + + + align:start position:0% +as an intervention I think that's the +covid-19 recession LED probably to what + + align:start position:0% +covid-19 recession LED probably to what + + + align:start position:0% +covid-19 recession LED probably to what +no not probably surely to the largest + + align:start position:0% +no not probably surely to the largest + + + align:start position:0% +no not probably surely to the largest +combined packaging history of policy + + align:start position:0% +combined packaging history of policy + + + align:start position:0% +combined packaging history of policy +support okay in terms of monetary policy + + align:start position:0% +support okay in terms of monetary policy + + + align:start position:0% +support okay in terms of monetary policy +and uh and fiscal + + align:start position:0% +and uh and fiscal + + + align:start position:0% +and uh and fiscal +policy + + align:start position:0% +policy + + + align:start position:0% +policy +so so that's what so what we're want to + + align:start position:0% +so so that's what so what we're want to + + + align:start position:0% +so so that's what so what we're want to +so we're going to after these two + + align:start position:0% +so we're going to after these two + + + align:start position:0% +so we're going to after these two +lectures you're going to get to + + align:start position:0% +lectures you're going to get to + + + align:start position:0% +lectures you're going to get to +understand essentially uh The Joint + + align:start position:0% +understand essentially uh The Joint + + + align:start position:0% +understand essentially uh The Joint +determination of output and interest + + align:start position:0% +determination of output and interest + + + align:start position:0% +determination of output and interest +rate H and we're going to be able to + + align:start position:0% +rate H and we're going to be able to + + + align:start position:0% +rate H and we're going to be able to +study as I said before the impact of + + align:start position:0% +study as I said before the impact of + + + align:start position:0% +study as I said before the impact of +monetary and fiscal policy and this + + align:start position:0% +monetary and fiscal policy and this + + + align:start position:0% +monetary and fiscal policy and this +framework that we're going to use to + + align:start position:0% +framework that we're going to use to + + + align:start position:0% +framework that we're going to use to +develop to to study this is what hick + + align:start position:0% +develop to to study this is what hick + + + align:start position:0% +develop to to study this is what hick +and Hansen initially called the + + align:start position:0% +and Hansen initially called the + + + align:start position:0% +and Hansen initially called the +islm + + align:start position:0% +islm + + + align:start position:0% +islm +model I already sort of hinted that that + + align:start position:0% +model I already sort of hinted that that + + + align:start position:0% +model I already sort of hinted that that +this was coming but why do you think the + + align:start position:0% +this was coming but why do you think the + + + align:start position:0% +this was coming but why do you think the +name + + align:start position:0% + + + + align:start position:0% + +I not the that I separate that is se you + + align:start position:0% +I not the that I separate that is se you + + + align:start position:0% +I not the that I separate that is se you +will separate is from LM remember what + + align:start position:0% +will separate is from LM remember what + + + align:start position:0% +will separate is from LM remember what +we're trying to do here we're trying to + + align:start position:0% +we're trying to do here we're trying to + + + align:start position:0% +we're trying to do here we're trying to +look at the Joint determination of + + align:start position:0% +look at the Joint determination of + + + align:start position:0% +look at the Joint determination of +output and interest rate that is we're + + align:start position:0% +output and interest rate that is we're + + + align:start position:0% +output and interest rate that is we're +trying to determine at at the Joint + + align:start position:0% +trying to determine at at the Joint + + + align:start position:0% +trying to determine at at the Joint +equilibrium of goods markets and + + align:start position:0% +equilibrium of goods markets and + + + align:start position:0% +equilibrium of goods markets and +financial + + align:start position:0% + + + + align:start position:0% + +markets when we describe the equilibrium + + align:start position:0% +markets when we describe the equilibrium + + + align:start position:0% +markets when we describe the equilibrium +in the goods Market we said there is an + + align:start position:0% +in the goods Market we said there is an + + + align:start position:0% +in the goods Market we said there is an +alternative way of describing remember I + + align:start position:0% +alternative way of describing remember I + + + align:start position:0% +alternative way of describing remember I +said it as investment equal to savings I + + align:start position:0% +said it as investment equal to savings I + + + align:start position:0% +said it as investment equal to savings I +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +S okay so the is part of the name comes + + align:start position:0% +S okay so the is part of the name comes + + + align:start position:0% +S okay so the is part of the name comes +from the part that has to do with + + align:start position:0% +from the part that has to do with + + + align:start position:0% +from the part that has to do with +equilibrium in the Goods Market is + + align:start position:0% +equilibrium in the Goods Market is + + + align:start position:0% +equilibrium in the Goods Market is +investment equal to savings and the LM + + align:start position:0% +investment equal to savings and the LM + + + align:start position:0% +investment equal to savings and the LM +part has to do remember L was that + + align:start position:0% +part has to do remember L was that + + + align:start position:0% +part has to do remember L was that +component of aggregate demand we we had + + align:start position:0% +component of aggregate demand we we had + + + align:start position:0% +component of aggregate demand we we had +in the financial markets we look at + + align:start position:0% +in the financial markets we look at + + + align:start position:0% +in the financial markets we look at +equilibrium as aggregate demand demand + + align:start position:0% +equilibrium as aggregate demand demand + + + align:start position:0% +equilibrium as aggregate demand demand +for money equal to supply of money + + align:start position:0% +for money equal to supply of money + + + align:start position:0% +for money equal to supply of money +supply of money was M demand for money + + align:start position:0% +supply of money was M demand for money + + + align:start position:0% +supply of money was M demand for money +was y * L of I and there therefore the + + align:start position:0% +was y * L of I and there therefore the + + + align:start position:0% +was y * L of I and there therefore the +LM part okay that's the reason that's a + + align:start position:0% +LM part okay that's the reason that's a + + + align:start position:0% +LM part okay that's the reason that's a +nemonic for why this model is called the + + align:start position:0% +nemonic for why this model is called the + + + align:start position:0% +nemonic for why this model is called the +is LM the is stands for the part that + + align:start position:0% +is LM the is stands for the part that + + + align:start position:0% +is LM the is stands for the part that +has to do with equilibrium in the Goods + + align:start position:0% +has to do with equilibrium in the Goods + + + align:start position:0% +has to do with equilibrium in the Goods +Market the L has to do with the part has + + align:start position:0% +Market the L has to do with the part has + + + align:start position:0% +Market the L has to do with the part has +to do with equilibrium Financial Market + + align:start position:0% +to do with equilibrium Financial Market + + + align:start position:0% +to do with equilibrium Financial Market +this model is a model that combines + + align:start position:0% +this model is a model that combines + + + align:start position:0% +this model is a model that combines +those two equilibrium okay so we're + + align:start position:0% +those two equilibrium okay so we're + + + align:start position:0% +those two equilibrium okay so we're +going to be interest interesting points + + align:start position:0% +going to be interest interesting points + + + align:start position:0% +going to be interest interesting points +in which both markets are in equilibrium + + align:start position:0% +in which both markets are in equilibrium + + + align:start position:0% +in which both markets are in equilibrium +that's the name of the game + + align:start position:0% +that's the name of the game + + + align:start position:0% +that's the name of the game +here so let's first develop the is + + align:start position:0% +here so let's first develop the is + + + align:start position:0% +here so let's first develop the is +relation and the yes relation is really + + align:start position:0% +relation and the yes relation is really + + + align:start position:0% +relation and the yes relation is really +going back to lecture three we're going + + align:start position:0% +going back to lecture three we're going + + + align:start position:0% +going back to lecture three we're going +to go back to lecture three use the same + + align:start position:0% +to go back to lecture three use the same + + + align:start position:0% +to go back to lecture three use the same +model we use in lecture three with one + + align:start position:0% +model we use in lecture three with one + + + align:start position:0% +model we use in lecture three with one +change and that change is a remember in + + align:start position:0% +change and that change is a remember in + + + align:start position:0% +change and that change is a remember in +in in lecture three we work a lot on a + + align:start position:0% +in in lecture three we work a lot on a + + + align:start position:0% +in in lecture three we work a lot on a +consumption the only endogenous the only + + align:start position:0% +consumption the only endogenous the only + + + align:start position:0% +consumption the only endogenous the only +function we had was a consumption + + align:start position:0% +function we had was a consumption + + + align:start position:0% +function we had was a consumption +function remember remember and then all + + align:start position:0% +function remember remember and then all + + + align:start position:0% +function remember remember and then all +the rest we took as sort of given + + align:start position:0% +the rest we took as sort of given + + + align:start position:0% +the rest we took as sort of given +government expenditure was given + + align:start position:0% +government expenditure was given + + + align:start position:0% +government expenditure was given +investment was given all that was given + + align:start position:0% +investment was given all that was given + + + align:start position:0% +investment was given all that was given +well we're going to relax one of those + + align:start position:0% +well we're going to relax one of those + + + align:start position:0% +well we're going to relax one of those +here and we're going to we're going to + + align:start position:0% +here and we're going to we're going to + + + align:start position:0% +here and we're going to we're going to +flesh out a little more of this + + align:start position:0% +flesh out a little more of this + + + align:start position:0% +flesh out a little more of this +investment here make get make it closer + + align:start position:0% +investment here make get make it closer + + + align:start position:0% +investment here make get make it closer +to what what a a realistic function it's + + align:start position:0% +to what what a a realistic function it's + + + align:start position:0% +to what what a a realistic function it's +not a constant obviously it's not to + + align:start position:0% +not a constant obviously it's not to + + + align:start position:0% +not a constant obviously it's not to +exogenous to equilibrium output and so + + align:start position:0% +exogenous to equilibrium output and so + + + align:start position:0% +exogenous to equilibrium output and so +on in fact we do know that real + + align:start position:0% +on in fact we do know that real + + + align:start position:0% +on in fact we do know that real +investment this is physical investment + + align:start position:0% +investment this is physical investment + + + align:start position:0% +investment this is physical investment +remember this is what is this ey is + + align:start position:0% +remember this is what is this ey is + + + align:start position:0% +remember this is what is this ey is +investment this is purchase of goods and + + align:start position:0% +investment this is purchase of goods and + + + align:start position:0% +investment this is purchase of goods and +services by firms for the purpose of + + align:start position:0% +services by firms for the purpose of + + + align:start position:0% +services by firms for the purpose of +building Capital Equipment structures + + align:start position:0% +building Capital Equipment structures + + + align:start position:0% +building Capital Equipment structures +and stuff like that I saw in PIAA very + + align:start position:0% +and stuff like that I saw in PIAA very + + + align:start position:0% +and stuff like that I saw in PIAA very +quickly I'm not into that but I see more + + align:start position:0% +quickly I'm not into that but I see more + + + align:start position:0% +quickly I'm not into that but I see more +or less the + + align:start position:0% +or less the + + + align:start position:0% +or less the +flow that somebody asked should bonds be + + align:start position:0% +flow that somebody asked should bonds be + + + align:start position:0% +flow that somebody asked should bonds be +included in + + align:start position:0% +included in + + + align:start position:0% +included in +investment what is the + + align:start position:0% +investment what is the + + + align:start position:0% +investment what is the +answer in that investment + + align:start position:0% + + + + align:start position:0% + +I should purchase of bonds be included + + align:start position:0% +I should purchase of bonds be included + + + align:start position:0% +I should purchase of bonds be included +in that investment + + align:start position:0% + + + + align:start position:0% + +no this is purchase of goods and + + align:start position:0% +no this is purchase of goods and + + + align:start position:0% +no this is purchase of goods and +services by firms no Capital machines + + align:start position:0% +services by firms no Capital machines + + + align:start position:0% +services by firms no Capital machines +stuff like that the other thing is a + + align:start position:0% +stuff like that the other thing is a + + + align:start position:0% +stuff like that the other thing is a +financial investment it's nothing to do + + align:start position:0% +financial investment it's nothing to do + + + align:start position:0% +financial investment it's nothing to do +with the Goods Market something that has + + align:start position:0% +with the Goods Market something that has + + + align:start position:0% +with the Goods Market something that has +to do with the financial Market not with + + align:start position:0% +to do with the financial Market not with + + + align:start position:0% +to do with the financial Market not with +a Goods Market a so that investment is + + align:start position:0% +a Goods Market a so that investment is + + + align:start position:0% +a Goods Market a so that investment is +real investment again purchase of + + align:start position:0% +real investment again purchase of + + + align:start position:0% +real investment again purchase of +capital buildings for the purpose of + + align:start position:0% +capital buildings for the purpose of + + + align:start position:0% +capital buildings for the purpose of +production and stuff like + + align:start position:0% +production and stuff like + + + align:start position:0% +production and stuff like +that okay and and this this in + + align:start position:0% +that okay and and this this in + + + align:start position:0% +that okay and and this this in +investment is is is a function of two + + align:start position:0% +investment is is is a function of two + + + align:start position:0% +investment is is is a function of two +things at least the first one is + + align:start position:0% +things at least the first one is + + + align:start position:0% +things at least the first one is +activity when output is high sales are + + align:start position:0% +activity when output is high sales are + + + align:start position:0% +activity when output is high sales are +high companies tend to invest more they + + align:start position:0% +high companies tend to invest more they + + + align:start position:0% +high companies tend to invest more they +buy more equipment they buy more + + align:start position:0% +buy more equipment they buy more + + + align:start position:0% +buy more equipment they buy more +buildings they expand okay so investment + + align:start position:0% +buildings they expand okay so investment + + + align:start position:0% +buildings they expand okay so investment +is an increasing function of output very + + align:start position:0% +is an increasing function of output very + + + align:start position:0% +is an increasing function of output very +much like consumption remember was an + + align:start position:0% +much like consumption remember was an + + + align:start position:0% +much like consumption remember was an +increasing function of output because + + align:start position:0% +increasing function of output because + + + align:start position:0% +increasing function of output because +income is increasing in output so was an + + align:start position:0% +income is increasing in output so was an + + + align:start position:0% +income is increasing in output so was an +increasing function out so this we + + align:start position:0% +increasing function out so this we + + + align:start position:0% +increasing function out so this we +already had SE functions that look like + + align:start position:0% +already had SE functions that look like + + + align:start position:0% +already had SE functions that look like +that and we already know what it does to + + align:start position:0% +that and we already know what it does to + + + align:start position:0% +that and we already know what it does to +aggregate demand no it makes that curve + + align:start position:0% +aggregate demand no it makes that curve + + + align:start position:0% +aggregate demand no it makes that curve +steeper remember and if the multiplier + + align:start position:0% +steeper remember and if the multiplier + + + align:start position:0% +steeper remember and if the multiplier +is behind that well investment gives you + + align:start position:0% +is behind that well investment gives you + + + align:start position:0% +is behind that well investment gives you +something similar there but there is a + + align:start position:0% +something similar there but there is a + + + align:start position:0% +something similar there but there is a +second component which is also present + + align:start position:0% +second component which is also present + + + align:start position:0% +second component which is also present +in consumption but it's not as important + + align:start position:0% +in consumption but it's not as important + + + align:start position:0% +in consumption but it's not as important +as if for investment which is the + + align:start position:0% +as if for investment which is the + + + align:start position:0% +as if for investment which is the +interest + + align:start position:0% +interest + + + align:start position:0% +interest +rate in particular when the interest + + align:start position:0% +rate in particular when the interest + + + align:start position:0% +rate in particular when the interest +rate goes up for any given level of + + align:start position:0% +rate goes up for any given level of + + + align:start position:0% +rate goes up for any given level of +income or output then investment goes + + align:start position:0% +income or output then investment goes + + + align:start position:0% +income or output then investment goes +down why do you think that's the case + + align:start position:0% + + + + align:start position:0% + +yes most of investment is funded with + + align:start position:0% +yes most of investment is funded with + + + align:start position:0% +yes most of investment is funded with +borrowing and borrowing becomes more + + align:start position:0% +borrowing and borrowing becomes more + + + align:start position:0% +borrowing and borrowing becomes more +expensive so so so you don't do it even + + align:start position:0% +expensive so so so you don't do it even + + + align:start position:0% +expensive so so so you don't do it even +if you don't need to borrow There's an + + align:start position:0% +if you don't need to borrow There's an + + + align:start position:0% +if you don't need to borrow There's an +opportunity cost of those funds you can + + align:start position:0% +opportunity cost of those funds you can + + + align:start position:0% +opportunity cost of those funds you can +use it to build machines to produce or + + align:start position:0% +use it to build machines to produce or + + + align:start position:0% +use it to build machines to produce or +you can do something else like like have + + align:start position:0% +you can do something else like like have + + + align:start position:0% +you can do something else like like have +an investment Financial investment so it + + align:start position:0% +an investment Financial investment so it + + + align:start position:0% +an investment Financial investment so it +whether you borrow or not still if the + + align:start position:0% +whether you borrow or not still if the + + + align:start position:0% +whether you borrow or not still if the +interest rate is + + align:start position:0% +interest rate is + + + align:start position:0% +interest rate is +higher the opportunity cost of building + + align:start position:0% +higher the opportunity cost of building + + + align:start position:0% +higher the opportunity cost of building +factories is higher High okay and and so + + align:start position:0% +factories is higher High okay and and so + + + align:start position:0% +factories is higher High okay and and so +that's a reason investment is decreasing + + align:start position:0% +that's a reason investment is decreasing + + + align:start position:0% +that's a reason investment is decreasing +with respect to the interest + + align:start position:0% +with respect to the interest + + + align:start position:0% +with respect to the interest +rate so now we go back to H our + + align:start position:0% +rate so now we go back to H our + + + align:start position:0% +rate so now we go back to H our +equilibrium in the Goods Market which we + + align:start position:0% +equilibrium in the Goods Market which we + + + align:start position:0% +equilibrium in the Goods Market which we +said production is whatever aggregate + + align:start position:0% +said production is whatever aggregate + + + align:start position:0% +said production is whatever aggregate +demand wants so output is going to be + + align:start position:0% +demand wants so output is going to be + + + align:start position:0% +demand wants so output is going to be +equal to aggregate demand aggregate + + align:start position:0% +equal to aggregate demand aggregate + + + align:start position:0% +equal to aggregate demand aggregate +demand is the same old aggregate demand + + align:start position:0% +demand is the same old aggregate demand + + + align:start position:0% +demand is the same old aggregate demand +we had except that now we flesh out what + + align:start position:0% +we had except that now we flesh out what + + + align:start position:0% +we had except that now we flesh out what +is inside that investment function there + + align:start position:0% +is inside that investment function there + + + align:start position:0% +is inside that investment function there +which we have another function is + + align:start position:0% +which we have another function is + + + align:start position:0% +which we have another function is +increasing in output like consumption + + align:start position:0% +increasing in output like consumption + + + align:start position:0% +increasing in output like consumption +was and + + align:start position:0% +was and + + + align:start position:0% +was and +but we also have something that is + + align:start position:0% +but we also have something that is + + + align:start position:0% +but we also have something that is +decreasing in the interest rate and so + + align:start position:0% +decreasing in the interest rate and so + + + align:start position:0% +decreasing in the interest rate and so +this is what we call the is relation and + + align:start position:0% +this is what we call the is relation and + + + align:start position:0% +this is what we call the is relation and +the the is relation + + align:start position:0% +the the is relation + + + align:start position:0% +the the is relation +therefore has all the combinations of + + align:start position:0% +therefore has all the combinations of + + + align:start position:0% +therefore has all the combinations of +output and interest rate that are + + align:start position:0% +output and interest rate that are + + + align:start position:0% +output and interest rate that are +consistent with equilibrium in the Goods + + align:start position:0% +consistent with equilibrium in the Goods + + + align:start position:0% +consistent with equilibrium in the Goods +Market listen at what I said I said the + + align:start position:0% +Market listen at what I said I said the + + + align:start position:0% +Market listen at what I said I said the +I relation or I curve has all the + + align:start position:0% +I relation or I curve has all the + + + align:start position:0% +I relation or I curve has all the +combinations of output and interest rate + + align:start position:0% +combinations of output and interest rate + + + align:start position:0% +combinations of output and interest rate +combinations of output and interest rate + + align:start position:0% +combinations of output and interest rate + + + align:start position:0% +combinations of output and interest rate +that are consistent with equilibrium in + + align:start position:0% +that are consistent with equilibrium in + + + align:start position:0% +that are consistent with equilibrium in +the Goods + + align:start position:0% +the Goods + + + align:start position:0% +the Goods +Market what about lecture + + align:start position:0% + + + + align:start position:0% + +three we already had that but interest + + align:start position:0% +three we already had that but interest + + + align:start position:0% +three we already had that but interest +Play No role so we found one point there + + align:start position:0% +Play No role so we found one point there + + + align:start position:0% +Play No role so we found one point there +there's one level of output which is + + align:start position:0% +there's one level of output which is + + + align:start position:0% +there's one level of output which is +consistent with equilibrium in the Goods + + align:start position:0% +consistent with equilibrium in the Goods + + + align:start position:0% +consistent with equilibrium in the Goods +Market that's what we found now since we + + align:start position:0% +Market that's what we found now since we + + + align:start position:0% +Market that's what we found now since we +have an interest rate there we have two + + align:start position:0% +have an interest rate there we have two + + + align:start position:0% +have an interest rate there we have two +variables for one curve so we can trace + + align:start position:0% +variables for one curve so we can trace + + + align:start position:0% +variables for one curve so we can trace +a curve which not only one + + align:start position:0% +a curve which not only one + + + align:start position:0% +a curve which not only one +point okay + + align:start position:0% +point okay + + + align:start position:0% +point okay +you can trace a + + align:start position:0% + + + + align:start position:0% + +curve + + align:start position:0% +curve + + + align:start position:0% +curve +and good and that's what we call the as + + align:start position:0% +and good and that's what we call the as + + + align:start position:0% +and good and that's what we call the as +relation + + align:start position:0% +relation + + + align:start position:0% +relation +so I remember I told you when we look at + + align:start position:0% +so I remember I told you when we look at + + + align:start position:0% +so I remember I told you when we look at +the Goods Market equ remember this + + align:start position:0% +the Goods Market equ remember this + + + align:start position:0% +the Goods Market equ remember this +diagram because you're going to come + + align:start position:0% +diagram because you're going to come + + + align:start position:0% +diagram because you're going to come +back to it many + + align:start position:0% +back to it many + + + align:start position:0% +back to it many +times there you are so remember when we + + align:start position:0% +times there you are so remember when we + + + align:start position:0% +times there you are so remember when we +look at equilibrium in the Goods Market + + align:start position:0% +look at equilibrium in the Goods Market + + + align:start position:0% +look at equilibrium in the Goods Market +we had something like that I'm I'm just + + align:start position:0% +we had something like that I'm I'm just + + + align:start position:0% +we had something like that I'm I'm just +making it curve rather than linear + + align:start position:0% +making it curve rather than linear + + + align:start position:0% +making it curve rather than linear +simply because I haven't specified the + + align:start position:0% +simply because I haven't specified the + + + align:start position:0% +simply because I haven't specified the +functional form of investment but + + align:start position:0% +functional form of investment but + + + align:start position:0% +functional form of investment but +doesn't matter really make it linear + + align:start position:0% +doesn't matter really make it linear + + + align:start position:0% +doesn't matter really make it linear +okay but remember we had that's the way + + align:start position:0% +okay but remember we had that's the way + + + align:start position:0% +okay but remember we had that's the way +we found equilibrium in the Goods Market + + align:start position:0% +we found equilibrium in the Goods Market + + + align:start position:0% +we found equilibrium in the Goods Market +we have an aggregate demand and it was + + align:start position:0% +we have an aggregate demand and it was + + + align:start position:0% +we have an aggregate demand and it was +increased the slope was positive because + + align:start position:0% +increased the slope was positive because + + + align:start position:0% +increased the slope was positive because +we had a margin of PR to consume that's + + align:start position:0% +we had a margin of PR to consume that's + + + align:start position:0% +we had a margin of PR to consume that's +the reason we had this was not flat but + + align:start position:0% +the reason we had this was not flat but + + + align:start position:0% +the reason we had this was not flat but +upward sloping no and we found + + align:start position:0% +upward sloping no and we found + + + align:start position:0% +upward sloping no and we found +equilibrium output that way okay so + + align:start position:0% +equilibrium output that way okay so + + + align:start position:0% +equilibrium output that way okay so +that's this is lecture three we're back + + align:start position:0% +that's this is lecture three we're back + + + align:start position:0% +that's this is lecture three we're back +in lecture three + + align:start position:0% +in lecture three + + + align:start position:0% +in lecture three +here with two things two differences the + + align:start position:0% +here with two things two differences the + + + align:start position:0% +here with two things two differences the +first one is that this ZZ curve relative + + align:start position:0% +first one is that this ZZ curve relative + + + align:start position:0% +first one is that this ZZ curve relative +to the one had in lecture three is a + + align:start position:0% +to the one had in lecture three is a + + + align:start position:0% +to the one had in lecture three is a +little steeper why is + + align:start position:0% + + + + align:start position:0% + +that why is it a little steeper than by + + align:start position:0% +that why is it a little steeper than by + + + align:start position:0% +that why is it a little steeper than by +steeper I mean if income goes up then + + align:start position:0% +steeper I mean if income goes up then + + + align:start position:0% +steeper I mean if income goes up then +aggregate demand goes up by more than + + align:start position:0% +aggregate demand goes up by more than + + + align:start position:0% +aggregate demand goes up by more than +than it used to go + + align:start position:0% + + + + align:start position:0% + +up exactly because what made it is + + align:start position:0% +up exactly because what made it is + + + align:start position:0% +up exactly because what made it is +upward sloping before was the margin of + + align:start position:0% +upward sloping before was the margin of + + + align:start position:0% +upward sloping before was the margin of +to consume but now there is also a + + align:start position:0% +to consume but now there is also a + + + align:start position:0% +to consume but now there is also a +margin of to invest which is also + + align:start position:0% +margin of to invest which is also + + + align:start position:0% +margin of to invest which is also +positive and that's the reason it's a + + align:start position:0% +positive and that's the reason it's a + + + align:start position:0% +positive and that's the reason it's a +little steeper more interesting for this + + align:start position:0% +little steeper more interesting for this + + + align:start position:0% +little steeper more interesting for this +part of the lecture though for the + + align:start position:0% +part of the lecture though for the + + + align:start position:0% +part of the lecture though for the +construction of the curve is that is a + + align:start position:0% +construction of the curve is that is a + + + align:start position:0% +construction of the curve is that is a +parameter that we have there in ZZ what + + align:start position:0% +parameter that we have there in ZZ what + + + align:start position:0% +parameter that we have there in ZZ what +are the parameters we had before in that + + align:start position:0% +are the parameters we had before in that + + + align:start position:0% +are the parameters we had before in that +curve we had things like going + + align:start position:0% +curve we had things like going + + + align:start position:0% +curve we had things like going +expenditure taxes the the autonomous + + align:start position:0% +expenditure taxes the the autonomous + + + align:start position:0% +expenditure taxes the the autonomous +consumption that's the kind of stuff + + align:start position:0% +consumption that's the kind of stuff + + + align:start position:0% +consumption that's the kind of stuff +that we had as parameters of that ZZ + + align:start position:0% +that we had as parameters of that ZZ + + + align:start position:0% +that we had as parameters of that ZZ +curve by parameters I mean if we change + + align:start position:0% +curve by parameters I mean if we change + + + align:start position:0% +curve by parameters I mean if we change +those parameter we shift that + + align:start position:0% +those parameter we shift that + + + align:start position:0% +those parameter we shift that +curve now for this particular ZZ we have + + align:start position:0% +curve now for this particular ZZ we have + + + align:start position:0% +curve now for this particular ZZ we have +an extra parameter which is very + + align:start position:0% +an extra parameter which is very + + + align:start position:0% +an extra parameter which is very +interesting what is that it's there I + + align:start position:0% +interesting what is that it's there I + + + align:start position:0% +interesting what is that it's there I +think it's the interest + + align:start position:0% +think it's the interest + + + align:start position:0% +think it's the interest +rate no that curve holds for some given + + align:start position:0% +rate no that curve holds for some given + + + align:start position:0% +rate no that curve holds for some given +interest + + align:start position:0% +interest + + + align:start position:0% +interest +rate if I move the interest I'm going to + + align:start position:0% +rate if I move the interest I'm going to + + + align:start position:0% +rate if I move the interest I'm going to +move this curve + + align:start position:0% +move this curve + + + align:start position:0% +move this curve +around that's very important + + align:start position:0% + + + + align:start position:0% + +one of the parameters there the star + + align:start position:0% +one of the parameters there the star + + + align:start position:0% +one of the parameters there the star +parameter I would say for this for this + + align:start position:0% +parameter I would say for this for this + + + align:start position:0% +parameter I would say for this for this +minute of the lecture at least for this + + align:start position:0% +minute of the lecture at least for this + + + align:start position:0% +minute of the lecture at least for this +moment in the lecture is the interest + + align:start position:0% +moment in the lecture is the interest + + + align:start position:0% +moment in the lecture is the interest +rate I can find an equilibrium because I + + align:start position:0% +rate I can find an equilibrium because I + + + align:start position:0% +rate I can find an equilibrium because I +couldn't find an equilibrium in the + + align:start position:0% +couldn't find an equilibrium in the + + + align:start position:0% +couldn't find an equilibrium in the +Goods Market if you don't tell me what + + align:start position:0% +Goods Market if you don't tell me what + + + align:start position:0% +Goods Market if you don't tell me what +the interest rate is because you know + + align:start position:0% +the interest rate is because you know + + + align:start position:0% +the interest rate is because you know +it's a curve remember I told you it's a + + align:start position:0% +it's a curve remember I told you it's a + + + align:start position:0% +it's a curve remember I told you it's a +relationship a curve so if I tell you I + + align:start position:0% +relationship a curve so if I tell you I + + + align:start position:0% +relationship a curve so if I tell you I +tell you what the interest rate is then + + align:start position:0% +tell you what the interest rate is then + + + align:start position:0% +tell you what the interest rate is then +you can find the equilibrium in the + + align:start position:0% +you can find the equilibrium in the + + + align:start position:0% +you can find the equilibrium in the +Goods Market because you can fix this + + align:start position:0% +Goods Market because you can fix this + + + align:start position:0% +Goods Market because you can fix this +curve + + align:start position:0% +curve + + + align:start position:0% +curve +okay that's for one given interest + + align:start position:0% + + + + align:start position:0% + +rate + + align:start position:0% +rate + + + align:start position:0% +rate +okay do do you understand that that's + + align:start position:0% +okay do do you understand that that's + + + align:start position:0% +okay do do you understand that that's +important + + align:start position:0% +important + + + align:start position:0% +important +yes those of you that are awake do you + + align:start position:0% +yes those of you that are awake do you + + + align:start position:0% +yes those of you that are awake do you +understand it or not not everyone is in + + align:start position:0% +understand it or not not everyone is in + + + align:start position:0% +understand it or not not everyone is in +the same page here okay + + align:start position:0% +the same page here okay + + + align:start position:0% +the same page here okay +good ER so let's now with that what + + align:start position:0% +good ER so let's now with that what + + + align:start position:0% +good ER so let's now with that what +we're going to do next is construct the + + align:start position:0% +we're going to do next is construct the + + + align:start position:0% +we're going to do next is construct the +is + + align:start position:0% +is + + + align:start position:0% +is +curve and and and how going remember + + align:start position:0% +curve and and and how going remember + + + align:start position:0% +curve and and and how going remember +what what I want to try to do is Con + + align:start position:0% +what what I want to try to do is Con + + + align:start position:0% +what what I want to try to do is Con +constructing the space of interest rate + + align:start position:0% +constructing the space of interest rate + + + align:start position:0% +constructing the space of interest rate +and output a curve which we're going to + + align:start position:0% +and output a curve which we're going to + + + align:start position:0% +and output a curve which we're going to +call the as + + align:start position:0% +call the as + + + align:start position:0% +call the as +curve at this point here we have a point + + align:start position:0% +curve at this point here we have a point + + + align:start position:0% +curve at this point here we have a point +in that curve because for one level of + + align:start position:0% +in that curve because for one level of + + + align:start position:0% +in that curve because for one level of +interest rate I found the equilibrium + + align:start position:0% +interest rate I found the equilibrium + + + align:start position:0% +interest rate I found the equilibrium +output so to construct the curve what I + + align:start position:0% +output so to construct the curve what I + + + align:start position:0% +output so to construct the curve what I +need to do is start moving the interest + + align:start position:0% +need to do is start moving the interest + + + align:start position:0% +need to do is start moving the interest +rate and see how the equilibrium output + + align:start position:0% +rate and see how the equilibrium output + + + align:start position:0% +rate and see how the equilibrium output +changes and that will trace a curve okay + + align:start position:0% +changes and that will trace a curve okay + + + align:start position:0% +changes and that will trace a curve okay +and that's going to be my + + align:start position:0% +and that's going to be my + + + align:start position:0% +and that's going to be my +is curve or relationship so let's do + + align:start position:0% +is curve or relationship so let's do + + + align:start position:0% +is curve or relationship so let's do +that + + align:start position:0% +that + + + align:start position:0% +that +that's a construction of the + + align:start position:0% +that's a construction of the + + + align:start position:0% +that's a construction of the +curve + + align:start position:0% +curve + + + align:start position:0% +curve +so in the previous chart we found point + + align:start position:0% +so in the previous chart we found point + + + align:start position:0% +so in the previous chart we found point +a so point a there is that point okay + + align:start position:0% +a so point a there is that point okay + + + align:start position:0% +a so point a there is that point okay +there we are we had some interest + + align:start position:0% +there we are we had some interest + + + align:start position:0% +there we are we had some interest +rate this interest rate I mean believe + + align:start position:0% +rate this interest rate I mean believe + + + align:start position:0% +rate this interest rate I mean believe +me that was a parameter of the ZZ curve + + align:start position:0% +me that was a parameter of the ZZ curve + + + align:start position:0% +me that was a parameter of the ZZ curve +I showed you before gave us equilibrium + + align:start position:0% +I showed you before gave us equilibrium + + + align:start position:0% +I showed you before gave us equilibrium +output + + align:start position:0% +output + + + align:start position:0% +output +a so that's a point in the yes because + + align:start position:0% +a so that's a point in the yes because + + + align:start position:0% +a so that's a point in the yes because +that's a combination of interest rate + + align:start position:0% +that's a combination of interest rate + + + align:start position:0% +that's a combination of interest rate +and output which is consistent with + + align:start position:0% +and output which is consistent with + + + align:start position:0% +and output which is consistent with +equilibrium in the Goods Market that's a + + align:start position:0% +equilibrium in the Goods Market that's a + + + align:start position:0% +equilibrium in the Goods Market that's a +point in the is that's a definition of + + align:start position:0% +point in the is that's a definition of + + + align:start position:0% +point in the is that's a definition of +is so now what I'm going to do to + + align:start position:0% +is so now what I'm going to do to + + + align:start position:0% +is so now what I'm going to do to +construct my is is okay let me move the + + align:start position:0% +construct my is is okay let me move the + + + align:start position:0% +construct my is is okay let me move the +interest rate let me raise interest rate + + align:start position:0% +interest rate let me raise interest rate + + + align:start position:0% +interest rate let me raise interest rate +from I to I prime okay that's an + + align:start position:0% +from I to I prime okay that's an + + + align:start position:0% +from I to I prime okay that's an +increase in the interest rate and now + + align:start position:0% +increase in the interest rate and now + + + align:start position:0% +increase in the interest rate and now +let me find what is a new equilibrium in + + align:start position:0% +let me find what is a new equilibrium in + + + align:start position:0% +let me find what is a new equilibrium in +the goods market for a given interest + + align:start position:0% +the goods market for a given interest + + + align:start position:0% +the goods market for a given interest +rate Which is higher than the one I used + + align:start position:0% +rate Which is higher than the one I used + + + align:start position:0% +rate Which is higher than the one I used +to have well that amounts to Shifting + + align:start position:0% +to have well that amounts to Shifting + + + align:start position:0% +to have well that amounts to Shifting +the ZZ curve down + + align:start position:0% +the ZZ curve down + + + align:start position:0% +the ZZ curve down +why does it increasing the interest rate + + align:start position:0% +why does it increasing the interest rate + + + align:start position:0% +why does it increasing the interest rate +shift the ZZ curve down the aggregate + + align:start position:0% +shift the ZZ curve down the aggregate + + + align:start position:0% +shift the ZZ curve down the aggregate +demand + + align:start position:0% + + + + align:start position:0% + +down it makes investment decline exactly + + align:start position:0% +down it makes investment decline exactly + + + align:start position:0% +down it makes investment decline exactly +B is for investment declines okay so + + align:start position:0% +B is for investment declines okay so + + + align:start position:0% +B is for investment declines okay so +that means for any given level of output + + align:start position:0% +that means for any given level of output + + + align:start position:0% +that means for any given level of output +now aggregate demand is lower because + + align:start position:0% +now aggregate demand is lower because + + + align:start position:0% +now aggregate demand is lower because +investment is lower and then you get the + + align:start position:0% +investment is lower and then you get the + + + align:start position:0% +investment is lower and then you get the +multiplier to do it stck no and + + align:start position:0% +multiplier to do it stck no and + + + align:start position:0% +multiplier to do it stck no and +therefore you tend end up with a + + align:start position:0% +therefore you tend end up with a + + + align:start position:0% +therefore you tend end up with a +declining output which is even larger + + align:start position:0% +declining output which is even larger + + + align:start position:0% +declining output which is even larger +than the declining invest the initial + + align:start position:0% +than the declining invest the initial + + + align:start position:0% +than the declining invest the initial +declining invest M as a result of + + align:start position:0% +declining invest M as a result of + + + align:start position:0% +declining invest M as a result of +increase in the interest rate that's + + align:start position:0% +increase in the interest rate that's + + + align:start position:0% +increase in the interest rate that's +what a multiplier does no so say + + align:start position:0% +what a multiplier does no so say + + + align:start position:0% +what a multiplier does no so say +interest rate increased by 100 100 basis + + align:start position:0% +interest rate increased by 100 100 basis + + + align:start position:0% +interest rate increased by 100 100 basis +points that reduce investment by a say10 + + align:start position:0% +points that reduce investment by a say10 + + + align:start position:0% +points that reduce investment by a say10 +billion and equilibrium output ends up + + align:start position:0% +billion and equilibrium output ends up + + + align:start position:0% +billion and equilibrium output ends up +falling by $15 billion because of the + + align:start position:0% +falling by $15 billion because of the + + + align:start position:0% +falling by $15 billion because of the +multiplier and so on okay but the point + + align:start position:0% +multiplier and so on okay but the point + + + align:start position:0% +multiplier and so on okay but the point +is after I do all my convergence to this + + align:start position:0% +is after I do all my convergence to this + + + align:start position:0% +is after I do all my convergence to this +new lower equilibrium level of output I + + align:start position:0% +new lower equilibrium level of output I + + + align:start position:0% +new lower equilibrium level of output I +have a second point in my as curve + + align:start position:0% +have a second point in my as curve + + + align:start position:0% +have a second point in my as curve +because that's a combination of a new + + align:start position:0% +because that's a combination of a new + + + align:start position:0% +because that's a combination of a new +interest rate I prime an output that is + + align:start position:0% +interest rate I prime an output that is + + + align:start position:0% +interest rate I prime an output that is +consistent with equilibrium in the Goods + + align:start position:0% +consistent with equilibrium in the Goods + + + align:start position:0% +consistent with equilibrium in the Goods +Market how do I know that it's + + align:start position:0% +Market how do I know that it's + + + align:start position:0% +Market how do I know that it's +consistent with equili in the Goods + + align:start position:0% +consistent with equili in the Goods + + + align:start position:0% +consistent with equili in the Goods +Market because I'm there I'm crossing 45 + + align:start position:0% +Market because I'm there I'm crossing 45 + + + align:start position:0% +Market because I'm there I'm crossing 45 +degree line that means output equal to + + align:start position:0% +degree line that means output equal to + + + align:start position:0% +degree line that means output equal to +aggregate demand that's equilibrium in + + align:start position:0% +aggregate demand that's equilibrium in + + + align:start position:0% +aggregate demand that's equilibrium in +the Goods + + align:start position:0% +the Goods + + + align:start position:0% +the Goods +Market okay + + align:start position:0% +Market okay + + + align:start position:0% +Market okay +so and of course you can keep going no + + align:start position:0% +so and of course you can keep going no + + + align:start position:0% +so and of course you can keep going no +and trace an entire curve and all that + + align:start position:0% +and trace an entire curve and all that + + + align:start position:0% +and trace an entire curve and all that +you'll do is you'll change the interest + + align:start position:0% +you'll do is you'll change the interest + + + align:start position:0% +you'll do is you'll change the interest +rate that will shift this curve then you + + align:start position:0% +rate that will shift this curve then you + + + align:start position:0% +rate that will shift this curve then you +do the multiplier and endend up with a + + align:start position:0% +do the multiplier and endend up with a + + + align:start position:0% +do the multiplier and endend up with a +new + + align:start position:0% +new + + + align:start position:0% +new +equilibrium and that's another point for + + align:start position:0% +equilibrium and that's another point for + + + align:start position:0% +equilibrium and that's another point for +your curve + + align:start position:0% +your curve + + + align:start position:0% +your curve +okay so is it clear how we constructed + + align:start position:0% +okay so is it clear how we constructed + + + align:start position:0% +okay so is it clear how we constructed +that + + align:start position:0% + + + + align:start position:0% + +curve very important okay + + align:start position:0% +curve very important okay + + + align:start position:0% +curve very important okay +good it's also very important to + + align:start position:0% +good it's also very important to + + + align:start position:0% +good it's also very important to +understand well so why is it downward + + align:start position:0% +understand well so why is it downward + + + align:start position:0% +understand well so why is it downward +sloping yeah that's a + + align:start position:0% + + + + align:start position:0% + +question why is it downward sloping + + align:start position:0% + + + + align:start position:0% + +what does it mean that it's downward + + align:start position:0% +what does it mean that it's downward + + + align:start position:0% +what does it mean that it's downward +slope that means that combination of + + align:start position:0% +slope that means that combination of + + + align:start position:0% +slope that means that combination of +output and interest rate that are + + align:start position:0% +output and interest rate that are + + + align:start position:0% +output and interest rate that are +consistent with equilibrium output are + + align:start position:0% +consistent with equilibrium output are + + + align:start position:0% +consistent with equilibrium output are +negatively correlated meaning you know I + + align:start position:0% +negatively correlated meaning you know I + + + align:start position:0% +negatively correlated meaning you know I +have a combination of high output and + + align:start position:0% +have a combination of high output and + + + align:start position:0% +have a combination of high output and +low interest rate is consistent + + align:start position:0% +low interest rate is consistent + + + align:start position:0% +low interest rate is consistent +or low high interest rate and low output + + align:start position:0% +or low high interest rate and low output + + + align:start position:0% +or low high interest rate and low output +that's what I find + + align:start position:0% +that's what I find + + + align:start position:0% +that's what I find +here but why is that why what is the + + align:start position:0% +here but why is that why what is the + + + align:start position:0% +here but why is that why what is the +logic of that behind that or the + + align:start position:0% +logic of that behind that or the + + + align:start position:0% +logic of that behind that or the +mechanism well the way to think about + + align:start position:0% +mechanism well the way to think about + + + align:start position:0% +mechanism well the way to think about +that is exactly the way I I did this + + align:start position:0% +that is exactly the way I I did this + + + align:start position:0% +that is exactly the way I I did this +experiment is okay let me think what + + align:start position:0% +experiment is okay let me think what + + + align:start position:0% +experiment is okay let me think what +happens if I increase the interest rate + + align:start position:0% +happens if I increase the interest rate + + + align:start position:0% +happens if I increase the interest rate +and I keep the level of output where it + + align:start position:0% +and I keep the level of output where it + + + align:start position:0% +and I keep the level of output where it +was so what happens if I increase the + + align:start position:0% +was so what happens if I increase the + + + align:start position:0% +was so what happens if I increase the +interest rate and I I keep the level of + + align:start position:0% +interest rate and I I keep the level of + + + align:start position:0% +interest rate and I I keep the level of +output at the level it + + align:start position:0% +output at the level it + + + align:start position:0% +output at the level it +was my claim is that that's not an + + align:start position:0% +was my claim is that that's not an + + + align:start position:0% +was my claim is that that's not an +equilibrium in the Goods Market what + + align:start position:0% +equilibrium in the Goods Market what + + + align:start position:0% +equilibrium in the Goods Market what +what is + + align:start position:0% + + + + align:start position:0% + +it so I'm saying suppose I increase the + + align:start position:0% +it so I'm saying suppose I increase the + + + align:start position:0% +it so I'm saying suppose I increase the +interest rate but I keep the output + + align:start position:0% +interest rate but I keep the output + + + align:start position:0% +interest rate but I keep the output +constant so output is here higher + + align:start position:0% +constant so output is here higher + + + align:start position:0% +constant so output is here higher +interest rate aggregate demand is + + align:start position:0% +interest rate aggregate demand is + + + align:start position:0% +interest rate aggregate demand is +there so what what is the problem I'm + + align:start position:0% +there so what what is the problem I'm + + + align:start position:0% +there so what what is the problem I'm +saying my claim is that's not an + + align:start position:0% +saying my claim is that's not an + + + align:start position:0% +saying my claim is that's not an +equilibrium in the Goods Market we're + + align:start position:0% +equilibrium in the Goods Market we're + + + align:start position:0% +equilibrium in the Goods Market we're +going to need a lower level of output to + + align:start position:0% +going to need a lower level of output to + + + align:start position:0% +going to need a lower level of output to +have an equilibrium in the Goods Market + + align:start position:0% +have an equilibrium in the Goods Market + + + align:start position:0% +have an equilibrium in the Goods Market +that's the reason it's downward sloping + + align:start position:0% +that's the reason it's downward sloping + + + align:start position:0% +that's the reason it's downward sloping +but why is that not an equilibrium in + + align:start position:0% +but why is that not an equilibrium in + + + align:start position:0% +but why is that not an equilibrium in +the Goods + + align:start position:0% +the Goods + + + align:start position:0% +the Goods +Market or what is the nature of the dise + + align:start position:0% +Market or what is the nature of the dise + + + align:start position:0% +Market or what is the nature of the dise +equilibrium in the Market there what do + + align:start position:0% +equilibrium in the Market there what do + + + align:start position:0% +equilibrium in the Market there what do +we have an excess demand excess + + align:start position:0% +we have an excess demand excess + + + align:start position:0% +we have an excess demand excess +Supply excess Supply meaning there isn't + + align:start position:0% +Supply excess Supply meaning there isn't + + + align:start position:0% +Supply excess Supply meaning there isn't +enough demand to support that + + align:start position:0% +enough demand to support that + + + align:start position:0% +enough demand to support that +Supply so supply has to fall in order to + + align:start position:0% +Supply so supply has to fall in order to + + + align:start position:0% +Supply so supply has to fall in order to +restore equilibrium in that market in + + align:start position:0% +restore equilibrium in that market in + + + align:start position:0% +restore equilibrium in that market in +the Goods Market okay and since one + + align:start position:0% +the Goods Market okay and since one + + + align:start position:0% +the Goods Market okay and since one +drags the other one it has to Fall by a + + align:start position:0% +drags the other one it has to Fall by a + + + align:start position:0% +drags the other one it has to Fall by a +lot that that has to do with the slope + + align:start position:0% +lot that that has to do with the slope + + + align:start position:0% +lot that that has to do with the slope +of this + + align:start position:0% +of this + + + align:start position:0% +of this +curve that's the reason it's negatively + + align:start position:0% +curve that's the reason it's negatively + + + align:start position:0% +curve that's the reason it's negatively +so that's first thing you have to + + align:start position:0% +so that's first thing you have to + + + align:start position:0% +so that's first thing you have to +understand understand when you construct + + align:start position:0% +understand understand when you construct + + + align:start position:0% +understand understand when you construct +this curve I know I'm going slowly but + + align:start position:0% +this curve I know I'm going slowly but + + + align:start position:0% +this curve I know I'm going slowly but +it's important when you con please try + + align:start position:0% +it's important when you con please try + + + align:start position:0% +it's important when you con please try +to + + align:start position:0% +to + + + align:start position:0% +to +understand why is that another way of + + align:start position:0% +understand why is that another way of + + + align:start position:0% +understand why is that another way of +saying + + align:start position:0% +saying + + + align:start position:0% +saying +it when I when I find the when I change + + align:start position:0% +it when I when I find the when I change + + + align:start position:0% +it when I when I find the when I change +the equilibrium output along this S + + align:start position:0% +the equilibrium output along this S + + + align:start position:0% +the equilibrium output along this S +curve by moving the inid around what I'm + + align:start position:0% +curve by moving the inid around what I'm + + + align:start position:0% +curve by moving the inid around what I'm +doing is I'm moving along an is curve + + align:start position:0% +doing is I'm moving along an is curve + + + align:start position:0% +doing is I'm moving along an is curve +okay so if I if the only reason why + + align:start position:0% +okay so if I if the only reason why + + + align:start position:0% +okay so if I if the only reason why +equilibrium out with is changing is + + align:start position:0% +equilibrium out with is changing is + + + align:start position:0% +equilibrium out with is changing is +because I'm moving the interest rate + + align:start position:0% +because I'm moving the interest rate + + + align:start position:0% +because I'm moving the interest rate +that's a movement along the S + + align:start position:0% +that's a movement along the S + + + align:start position:0% +that's a movement along the S +curve okay so I'm I'm tracing points of + + align:start position:0% +curve okay so I'm I'm tracing points of + + + align:start position:0% +curve okay so I'm I'm tracing points of +the as curve good and I want to draw a + + align:start position:0% +the as curve good and I want to draw a + + + align:start position:0% +the as curve good and I want to draw a +contrast between these movements along + + align:start position:0% +contrast between these movements along + + + align:start position:0% +contrast between these movements along +the is curve versus things that shift + + align:start position:0% +the is curve versus things that shift + + + align:start position:0% +the is curve versus things that shift +the + + align:start position:0% +the + + + align:start position:0% +the +curve okay for + + align:start position:0% +curve okay for + + + align:start position:0% +curve okay for +example + + align:start position:0% +example + + + align:start position:0% +example +that so suppose I increase taxes + + align:start position:0% + + + + align:start position:0% + +increase taxes the government increases + + align:start position:0% +increase taxes the government increases + + + align:start position:0% +increase taxes the government increases +taxes my claim is that the is shift to + + align:start position:0% +taxes my claim is that the is shift to + + + align:start position:0% +taxes my claim is that the is shift to +the + + align:start position:0% +the + + + align:start position:0% +the +left that is for any given level of + + align:start position:0% +left that is for any given level of + + + align:start position:0% +left that is for any given level of +interest rate pick any interest you + + align:start position:0% +interest rate pick any interest you + + + align:start position:0% +interest rate pick any interest you +want say this one you're going to have a + + align:start position:0% +want say this one you're going to have a + + + align:start position:0% +want say this one you're going to have a +lower equilibrium output consistent with + + align:start position:0% +lower equilibrium output consistent with + + + align:start position:0% +lower equilibrium output consistent with +that interest rate if you have a lower + + align:start position:0% +that interest rate if you have a lower + + + align:start position:0% +that interest rate if you have a lower +equilibrium consistent with the same + + align:start position:0% +equilibrium consistent with the same + + + align:start position:0% +equilibrium consistent with the same +interest rate that has shifted the + + align:start position:0% +interest rate that has shifted the + + + align:start position:0% +interest rate that has shifted the +is has to be a different is + + align:start position:0% +is has to be a different is + + + align:start position:0% +is has to be a different is +okay and and think that I can do that + + align:start position:0% +okay and and think that I can do that + + + align:start position:0% +okay and and think that I can do that +for any given level of in I pick this + + align:start position:0% +for any given level of in I pick this + + + align:start position:0% +for any given level of in I pick this +one but I could have pick that one would + + align:start position:0% +one but I could have pick that one would + + + align:start position:0% +one but I could have pick that one would +have been the same I'm saying you + + align:start position:0% +have been the same I'm saying you + + + align:start position:0% +have been the same I'm saying you +increase + + align:start position:0% +increase + + + align:start position:0% +increase +taxes that's going to lead to lower + + align:start position:0% +taxes that's going to lead to lower + + + align:start position:0% +taxes that's going to lead to lower +equilibrium + + align:start position:0% +equilibrium + + + align:start position:0% +equilibrium +output so that means that for this + + align:start position:0% +output so that means that for this + + + align:start position:0% +output so that means that for this +higher level of taxes I will have to + + align:start position:0% +higher level of taxes I will have to + + + align:start position:0% +higher level of taxes I will have to +trace a different test + + align:start position:0% +trace a different test + + + align:start position:0% +trace a different test +curve I can start moving the interest + + align:start position:0% +curve I can start moving the interest + + + align:start position:0% +curve I can start moving the interest +rate around but I'm going to have a + + align:start position:0% +rate around but I'm going to have a + + + align:start position:0% +rate around but I'm going to have a +lower level of output for any given + + align:start position:0% +lower level of output for any given + + + align:start position:0% +lower level of output for any given +level of interest rate because I have + + align:start position:0% +level of interest rate because I have + + + align:start position:0% +level of interest rate because I have +higher taxes + + align:start position:0% +higher taxes + + + align:start position:0% +higher taxes +so how do I know that an increas in + + align:start position:0% +so how do I know that an increas in + + + align:start position:0% +so how do I know that an increas in +taxes will do this Which diagram would + + align:start position:0% +taxes will do this Which diagram would + + + align:start position:0% +taxes will do this Which diagram would +you go to to try to understand + + align:start position:0% + + + + align:start position:0% + +this so or let me ask it + + align:start position:0% +this so or let me ask it + + + align:start position:0% +this so or let me ask it +differently how do I know that this + + align:start position:0% +differently how do I know that this + + + align:start position:0% +differently how do I know that this +stuff shift to the left so I give you + + align:start position:0% +stuff shift to the left so I give you + + + align:start position:0% +stuff shift to the left so I give you +more open space how do I know that this + + align:start position:0% +more open space how do I know that this + + + align:start position:0% +more open space how do I know that this +increasing taxes will shift this is + + align:start position:0% +increasing taxes will shift this is + + + align:start position:0% +increasing taxes will shift this is +curve to the left how would you go about + + align:start position:0% +curve to the left how would you go about + + + align:start position:0% +curve to the left how would you go about +thinking + + align:start position:0% + + + + align:start position:0% + +not going to spend as much money less + + align:start position:0% +not going to spend as much money less + + + align:start position:0% +not going to spend as much money less +outcome there will be less aggregate + + align:start position:0% +outcome there will be less aggregate + + + align:start position:0% +outcome there will be less aggregate +demand and less aggregate demand leads + + align:start position:0% +demand and less aggregate demand leads + + + align:start position:0% +demand and less aggregate demand leads +to less output because output is + + align:start position:0% +to less output because output is + + + align:start position:0% +to less output because output is +aggregate demand deter exactly that's + + align:start position:0% +aggregate demand deter exactly that's + + + align:start position:0% +aggregate demand deter exactly that's +what equilibrium in the Goods Market so + + align:start position:0% +what equilibrium in the Goods Market so + + + align:start position:0% +what equilibrium in the Goods Market so +you can go back to this diagram this + + align:start position:0% +you can go back to this diagram this + + + align:start position:0% +you can go back to this diagram this +goes in the I could say ignore these + + align:start position:0% +goes in the I could say ignore these + + + align:start position:0% +goes in the I could say ignore these +labels here and say look for any given + + align:start position:0% +labels here and say look for any given + + + align:start position:0% +labels here and say look for any given +level of interest rate pick any if I + + align:start position:0% +level of interest rate pick any if I + + + align:start position:0% +level of interest rate pick any if I +increase tax I'm going to shift the Z ZZ + + align:start position:0% +increase tax I'm going to shift the Z ZZ + + + align:start position:0% +increase tax I'm going to shift the Z ZZ +curve + + align:start position:0% +curve + + + align:start position:0% +curve +down okay so ignore the this charar + + align:start position:0% +down okay so ignore the this charar + + + align:start position:0% +down okay so ignore the this charar +suppose that I fix the interest rate but + + align:start position:0% +suppose that I fix the interest rate but + + + align:start position:0% +suppose that I fix the interest rate but +I now change taxes increase taxes well + + align:start position:0% +I now change taxes increase taxes well + + + align:start position:0% +I now change taxes increase taxes well +I'm going to do exactly the same here + + align:start position:0% +I'm going to do exactly the same here + + + align:start position:0% +I'm going to do exactly the same here +I'm going to move this down and it's + + align:start position:0% +I'm going to move this down and it's + + + align:start position:0% +I'm going to move this down and it's +going to be a different is curve though + + align:start position:0% +going to be a different is curve though + + + align:start position:0% +going to be a different is curve though +because I shouldn't have used this + + align:start position:0% +because I shouldn't have used this + + + align:start position:0% +because I shouldn't have used this +diagram let me keep your answer I should + + align:start position:0% +diagram let me keep your answer I should + + + align:start position:0% +diagram let me keep your answer I should +have put a new diagram but it's it's + + align:start position:0% +have put a new diagram but it's it's + + + align:start position:0% +have put a new diagram but it's it's +lecture three in lecture three we did + + align:start position:0% +lecture three in lecture three we did + + + align:start position:0% +lecture three in lecture three we did +see that that an increase in tax would + + align:start position:0% +see that that an increase in tax would + + + align:start position:0% +see that that an increase in tax would +lead to lower equilibrium output + + align:start position:0% +lead to lower equilibrium output + + + align:start position:0% +lead to lower equilibrium output +in fact we know exactly by how much if + + align:start position:0% +in fact we know exactly by how much if + + + align:start position:0% +in fact we know exactly by how much if +if taxes increase by 100 then you know + + align:start position:0% +if taxes increase by 100 then you know + + + align:start position:0% +if taxes increase by 100 then you know +that equilibrium output would decline by + + align:start position:0% +that equilibrium output would decline by + + + align:start position:0% +that equilibrium output would decline by +C1 times 1 / minus + + align:start position:0% +C1 times 1 / minus + + + align:start position:0% +C1 times 1 / minus +C1 changing taxes here would be a little + + align:start position:0% +C1 changing taxes here would be a little + + + align:start position:0% +C1 changing taxes here would be a little +different because there is also remember + + align:start position:0% +different because there is also remember + + + align:start position:0% +different because there is also remember +investment also has a propensity to to + + align:start position:0% +investment also has a propensity to to + + + align:start position:0% +investment also has a propensity to to +to to spend as a function of output so + + align:start position:0% +to to spend as a function of output so + + + align:start position:0% +to to spend as a function of output so +so it would be a little different but + + align:start position:0% +so it would be a little different but + + + align:start position:0% +so it would be a little different but +that's the kind of + + align:start position:0% +that's the kind of + + + align:start position:0% +that's the kind of +calculation okay what else would shift + + align:start position:0% +calculation okay what else would shift + + + align:start position:0% +calculation okay what else would shift +the the is this + + align:start position:0% + + + + align:start position:0% + +way decrease in governance friend would + + align:start position:0% +way decrease in governance friend would + + + align:start position:0% +way decrease in governance friend would +do that what + + align:start position:0% +do that what + + + align:start position:0% +do that what +else this this another thing I want you + + align:start position:0% +else this this another thing I want you + + + align:start position:0% +else this this another thing I want you +to think of any everything because for + + align:start position:0% +to think of any everything because for + + + align:start position:0% +to think of any everything because for +sure you're going to face that in the + + align:start position:0% +sure you're going to face that in the + + + align:start position:0% +sure you're going to face that in the +quiz that anything that would shift the + + align:start position:0% +quiz that anything that would shift the + + + align:start position:0% +quiz that anything that would shift the +curve what else would shift the + + align:start position:0% + + + + align:start position:0% + +curve yeah that's true but but but + + align:start position:0% +curve yeah that's true but but but + + + align:start position:0% +curve yeah that's true but but but +that's not for this part of the course + + align:start position:0% +that's not for this part of the course + + + align:start position:0% +that's not for this part of the course +remember we're in a close economy so + + align:start position:0% +remember we're in a close economy so + + + align:start position:0% +remember we're in a close economy so +here we assume xal to m equal to zero I + + align:start position:0% +here we assume xal to m equal to zero I + + + align:start position:0% +here we assume xal to m equal to zero I +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +zero that comes from after quiz one what + + align:start position:0% + + + + align:start position:0% + +else things that were captur remember + + align:start position:0% +else things that were captur remember + + + align:start position:0% +else things that were captur remember +when I began this lecture I show you + + align:start position:0% +when I began this lecture I show you + + + align:start position:0% +when I began this lecture I show you +wealth what had happened and so on well + + align:start position:0% +wealth what had happened and so on well + + + align:start position:0% +wealth what had happened and so on well +there's nowhere wealth in this model + + align:start position:0% +there's nowhere wealth in this model + + + align:start position:0% +there's nowhere wealth in this model +here it's just output but wealth affects + + align:start position:0% +here it's just output but wealth affects + + + align:start position:0% +here it's just output but wealth affects +how much consumers consume so autonomous + + align:start position:0% +how much consumers consume so autonomous + + + align:start position:0% +how much consumers consume so autonomous +consumption there were lots of stuff + + align:start position:0% +consumption there were lots of stuff + + + align:start position:0% +consumption there were lots of stuff +hidden in that c0 that constant c0 + + align:start position:0% +hidden in that c0 that constant c0 + + + align:start position:0% +hidden in that c0 that constant c0 +remember c0 plus C1 one well c0 captures + + align:start position:0% +remember c0 plus C1 one well c0 captures + + + align:start position:0% +remember c0 plus C1 one well c0 captures +things like how confident were consumers + + align:start position:0% +things like how confident were consumers + + + align:start position:0% +things like how confident were consumers +how wealthy they felt and stuff like + + align:start position:0% +how wealthy they felt and stuff like + + + align:start position:0% +how wealthy they felt and stuff like +that so anything that shift C down + + align:start position:0% +that so anything that shift C down + + + align:start position:0% +that so anything that shift C down +consumer sentiment declines wealth + + align:start position:0% +consumer sentiment declines wealth + + + align:start position:0% +consumer sentiment declines wealth +declines something like that will also + + align:start position:0% +declines something like that will also + + + align:start position:0% +declines something like that will also +shift yes to the left okay so that's + + align:start position:0% + + + + align:start position:0% + +important good so now so we're done with + + align:start position:0% +important good so now so we're done with + + + align:start position:0% +important good so now so we're done with +is for + + align:start position:0% +is for + + + align:start position:0% +is for +now now with the is alone I cannot find + + align:start position:0% +now now with the is alone I cannot find + + + align:start position:0% +now now with the is alone I cannot find +what I want I want to find equili + + align:start position:0% +what I want I want to find equili + + + align:start position:0% +what I want I want to find equili +combinations of interest rate and output + + align:start position:0% +combinations of interest rate and output + + + align:start position:0% +combinations of interest rate and output +that are consistent with equilibrium in + + align:start position:0% +that are consistent with equilibrium in + + + align:start position:0% +that are consistent with equilibrium in +the goods and financial markets this + + align:start position:0% +the goods and financial markets this + + + align:start position:0% +the goods and financial markets this +doesn't do it because it gives you only + + align:start position:0% +doesn't do it because it gives you only + + + align:start position:0% +doesn't do it because it gives you only +combinations that are consistent with + + align:start position:0% +combinations that are consistent with + + + align:start position:0% +combinations that are consistent with +equilibrium in the Goods Market + + align:start position:0% +equilibrium in the Goods Market + + + align:start position:0% +equilibrium in the Goods Market +okay and in fact okay so I now need to + + align:start position:0% +okay and in fact okay so I now need to + + + align:start position:0% +okay and in fact okay so I now need to +look at Financial Market which is the + + align:start position:0% +look at Financial Market which is the + + + align:start position:0% +look at Financial Market which is the +other side the LM relation ship and + + align:start position:0% +other side the LM relation ship and + + + align:start position:0% +other side the LM relation ship and +remember what we had is we had + + align:start position:0% +remember what we had is we had + + + align:start position:0% +remember what we had is we had +equilibrium in the in the financial + + align:start position:0% +equilibrium in the in the financial + + + align:start position:0% +equilibrium in the in the financial +Market we had two instruments that we + + align:start position:0% +Market we had two instruments that we + + + align:start position:0% +Market we had two instruments that we +could use remember we had only two + + align:start position:0% +could use remember we had only two + + + align:start position:0% +could use remember we had only two +assets money and bonds so we could look + + align:start position:0% +assets money and bonds so we could look + + + align:start position:0% +assets money and bonds so we could look +at the equilibrium in in in the in money + + align:start position:0% +at the equilibrium in in in the in money + + + align:start position:0% +at the equilibrium in in in the in money +or equilibrium in bonds is the + + align:start position:0% +or equilibrium in bonds is the + + + align:start position:0% +or equilibrium in bonds is the +same but we we did it all in in terms of + + align:start position:0% +same but we we did it all in in terms of + + + align:start position:0% +same but we we did it all in in terms of +money it's the same because given wealth + + align:start position:0% +money it's the same because given wealth + + + align:start position:0% +money it's the same because given wealth +if one is in equilibrium the other one + + align:start position:0% +if one is in equilibrium the other one + + + align:start position:0% +if one is in equilibrium the other one +has to be in equilibrium as well so I I + + align:start position:0% +has to be in equilibrium as well so I I + + + align:start position:0% +has to be in equilibrium as well so I I +only need to look at one and we're + + align:start position:0% +only need to look at one and we're + + + align:start position:0% +only need to look at one and we're +looking at money okay so money is equal + + align:start position:0% +looking at money okay so money is equal + + + align:start position:0% +looking at money okay so money is equal +to money + + align:start position:0% +to money + + + align:start position:0% +to money +demand I'm going to divide both sides by + + align:start position:0% +demand I'm going to divide both sides by + + + align:start position:0% +demand I'm going to divide both sides by +P this is not going to be very important + + align:start position:0% +P this is not going to be very important + + + align:start position:0% +P this is not going to be very important +now but later we will be and so we're + + align:start position:0% +now but later we will be and so we're + + + align:start position:0% +now but later we will be and so we're +going to have that this is is + + align:start position:0% +going to have that this is is + + + align:start position:0% +going to have that this is is +equilibrium in in in financial Market + + align:start position:0% +equilibrium in in in financial Market + + + align:start position:0% +equilibrium in in in financial Market +means that real real H money supply + + align:start position:0% +means that real real H money supply + + + align:start position:0% +means that real real H money supply +equals real money demand okay that's + + align:start position:0% +equals real money demand okay that's + + + align:start position:0% +equals real money demand okay that's +what we have + + align:start position:0% +what we have + + + align:start position:0% +what we have +here so this you already see it traces + + align:start position:0% +here so this you already see it traces + + + align:start position:0% +here so this you already see it traces +combinations of out put an interest rate + + align:start position:0% +combinations of out put an interest rate + + + align:start position:0% +combinations of out put an interest rate +which are consistent with equilibrium in + + align:start position:0% +which are consistent with equilibrium in + + + align:start position:0% +which are consistent with equilibrium in +financial + + align:start position:0% +financial + + + align:start position:0% +financial +markets + + align:start position:0% +markets + + + align:start position:0% +markets +okay in the past that's the way the LM + + align:start position:0% +okay in the past that's the way the LM + + + align:start position:0% +okay in the past that's the way the LM +would be + + align:start position:0% +would be + + + align:start position:0% +would be +described we would fix M and say well + + align:start position:0% +described we would fix M and say well + + + align:start position:0% +described we would fix M and say well +this will give you an upward sloping + + align:start position:0% +this will give you an upward sloping + + + align:start position:0% +this will give you an upward sloping +curve no because this is downward + + align:start position:0% +curve no because this is downward + + + align:start position:0% +curve no because this is downward +sloping so if this guy goes up I need to + + align:start position:0% +sloping so if this guy goes up I need to + + + align:start position:0% +sloping so if this guy goes up I need to +if this is constant this guy goes up + + align:start position:0% +if this is constant this guy goes up + + + align:start position:0% +if this is constant this guy goes up +well this guy needs to come down what + + align:start position:0% +well this guy needs to come down what + + + align:start position:0% +well this guy needs to come down what +does that what does bring L down well I + + align:start position:0% +does that what does bring L down well I + + + align:start position:0% +does that what does bring L down well I +go up because L Prime is negative so + + align:start position:0% +go up because L Prime is negative so + + + align:start position:0% +go up because L Prime is negative so +that's the way LM used to be described + + align:start position:0% +that's the way LM used to be described + + + align:start position:0% +that's the way LM used to be described +your life is a lot simpler today it's a + + align:start position:0% +your life is a lot simpler today it's a + + + align:start position:0% +your life is a lot simpler today it's a +lot simpler because central banks don't + + align:start position:0% +lot simpler because central banks don't + + + align:start position:0% +lot simpler because central banks don't +Target monetary aggates they don't + + align:start position:0% +Target monetary aggates they don't + + + align:start position:0% +Target monetary aggates they don't +Target M they target the interest rate + + align:start position:0% +Target M they target the interest rate + + + align:start position:0% +Target M they target the interest rate +directly so they tell you the answer + + align:start position:0% +directly so they tell you the answer + + + align:start position:0% +directly so they tell you the answer +already they + + align:start position:0% +already they + + + align:start position:0% +already they +said what Central Bank when it does + + align:start position:0% +said what Central Bank when it does + + + align:start position:0% +said what Central Bank when it does +policy says look I tell you what I will + + align:start position:0% +policy says look I tell you what I will + + + align:start position:0% +policy says look I tell you what I will +be then if output moves around whatever + + align:start position:0% +be then if output moves around whatever + + + align:start position:0% +be then if output moves around whatever +that's that's problem it's a problem for + + align:start position:0% +that's that's problem it's a problem for + + + align:start position:0% +that's that's problem it's a problem for +M we'll provide the M that the market + + align:start position:0% +M we'll provide the M that the market + + + align:start position:0% +M we'll provide the M that the market +needs in order to have interest rate + + align:start position:0% +needs in order to have interest rate + + + align:start position:0% +needs in order to have interest rate +equal to the one we want okay so so it's + + align:start position:0% +equal to the one we want okay so so it's + + + align:start position:0% +equal to the one we want okay so so it's +it's it it is true that it captures all + + align:start position:0% +it's it it is true that it captures all + + + align:start position:0% +it's it it is true that it captures all +the combinations of output and interest + + align:start position:0% +the combinations of output and interest + + + align:start position:0% +the combinations of output and interest +that are consistent with equilibrium in + + align:start position:0% +that are consistent with equilibrium in + + + align:start position:0% +that are consistent with equilibrium in +the financial markets but it's very + + align:start position:0% +the financial markets but it's very + + + align:start position:0% +the financial markets but it's very +simple because the the the what the FED + + align:start position:0% +simple because the the the what the FED + + + align:start position:0% +simple because the the the what the FED +does in the US other central banks do is + + align:start position:0% +does in the US other central banks do is + + + align:start position:0% +does in the US other central banks do is +they say okay this is the interest rate + + align:start position:0% +they say okay this is the interest rate + + + align:start position:0% +they say okay this is the interest rate +we want and now you can put any amount + + align:start position:0% +we want and now you can put any amount + + + align:start position:0% +we want and now you can put any amount +of output you want as long as we remain + + align:start position:0% +of output you want as long as we remain + + + align:start position:0% +of output you want as long as we remain +committed to this interest rate it will + + align:start position:0% +committed to this interest rate it will + + + align:start position:0% +committed to this interest rate it will +be consistent with equilibrium in the in + + align:start position:0% +be consistent with equilibrium in the in + + + align:start position:0% +be consistent with equilibrium in the in +the financial markets because we will do + + align:start position:0% +the financial markets because we will do + + + align:start position:0% +the financial markets because we will do +it so and the way we will do it so is + + align:start position:0% +it so and the way we will do it so is + + + align:start position:0% +it so and the way we will do it so is +we'll provide as much M as the market + + align:start position:0% +we'll provide as much M as the market + + + align:start position:0% +we'll provide as much M as the market +needs so that that combination of output + + align:start position:0% +needs so that that combination of output + + + align:start position:0% +needs so that that combination of output +and interest rate is an equilibrium in + + align:start position:0% +and interest rate is an equilibrium in + + + align:start position:0% +and interest rate is an equilibrium in +the financial Market that is that's a + + align:start position:0% +the financial Market that is that's a + + + align:start position:0% +the financial Market that is that's a +very long way of saying that the FED + + align:start position:0% +very long way of saying that the FED + + + align:start position:0% +very long way of saying that the FED +sets I and then m is whatever this is + + align:start position:0% +sets I and then m is whatever this is + + + align:start position:0% +sets I and then m is whatever this is +needed for this equation to be in + + align:start position:0% +needed for this equation to be in + + + align:start position:0% +needed for this equation to be in +equilibrium so if output Rises and The + + align:start position:0% +equilibrium so if output Rises and The + + + align:start position:0% +equilibrium so if output Rises and The +Fed doesn't want to change the interest + + align:start position:0% +Fed doesn't want to change the interest + + + align:start position:0% +Fed doesn't want to change the interest +rate that means you need to change m + + align:start position:0% +rate that means you need to change m + + + align:start position:0% +rate that means you need to change m +okay so suppose that the FED says I want + + align:start position:0% +okay so suppose that the FED says I want + + + align:start position:0% +okay so suppose that the FED says I want +this interest rate to be fixed at this + + align:start position:0% +this interest rate to be fixed at this + + + align:start position:0% +this interest rate to be fixed at this +level call it I zero and now output + + align:start position:0% +level call it I zero and now output + + + align:start position:0% +level call it I zero and now output +turns out to be + + align:start position:0% + + + + align:start position:0% + +higher what will the FED do in order to + + align:start position:0% +higher what will the FED do in order to + + + align:start position:0% +higher what will the FED do in order to +ensure that I remains at i z what if the + + align:start position:0% +ensure that I remains at i z what if the + + + align:start position:0% +ensure that I remains at i z what if the +FED doesn't do + + align:start position:0% +FED doesn't do + + + align:start position:0% +FED doesn't do +anything so the FED says I want I equals + + align:start position:0% +anything so the FED says I want I equals + + + align:start position:0% +anything so the FED says I want I equals +z and and the FED is calculated that + + align:start position:0% +z and and the FED is calculated that + + + align:start position:0% +z and and the FED is calculated that +output will be about certain level and + + align:start position:0% +output will be about certain level and + + + align:start position:0% +output will be about certain level and +it turns out that output is higher + + align:start position:0% +it turns out that output is higher + + + align:start position:0% +it turns out that output is higher +what happens if the FED doesn't + + align:start position:0% + + + + align:start position:0% + +react and keeps the interest rate at I + + align:start position:0% +react and keeps the interest rate at I + + + align:start position:0% +react and keeps the interest rate at I +zero and output T to be higher than what + + align:start position:0% +zero and output T to be higher than what + + + align:start position:0% +zero and output T to be higher than what +they thought when they provided the M + + align:start position:0% +they thought when they provided the M + + + align:start position:0% +they thought when they provided the M +that they thought the market needed to + + align:start position:0% +that they thought the market needed to + + + align:start position:0% +that they thought the market needed to +be in equilibrium of that interest rate + + align:start position:0% +be in equilibrium of that interest rate + + + align:start position:0% +be in equilibrium of that interest rate +what will + + align:start position:0% + + + + align:start position:0% + +happen well the interest rate will go up + + align:start position:0% +happen well the interest rate will go up + + + align:start position:0% +happen well the interest rate will go up +because money demand will exceed money + + align:start position:0% +because money demand will exceed money + + + align:start position:0% +because money demand will exceed money +supply well the only way to restory + + align:start position:0% +supply well the only way to restory + + + align:start position:0% +supply well the only way to restory +equilibrium is for interest rate to go + + align:start position:0% +equilibrium is for interest rate to go + + + align:start position:0% +equilibrium is for interest rate to go +up but the FED doesn't want that so what + + align:start position:0% +up but the FED doesn't want that so what + + + align:start position:0% +up but the FED doesn't want that so what +the FED will do is when it feels that it + + align:start position:0% +the FED will do is when it feels that it + + + align:start position:0% +the FED will do is when it feels that it +feels the interest rat are going up they + + align:start position:0% +feels the interest rat are going up they + + + align:start position:0% +feels the interest rat are going up they +will provide more money so so they can + + align:start position:0% +will provide more money so so they can + + + align:start position:0% +will provide more money so so they can +restore equilibrium in the financial + + align:start position:0% +restore equilibrium in the financial + + + align:start position:0% +restore equilibrium in the financial +Market at that level of interest rate + + align:start position:0% +Market at that level of interest rate + + + align:start position:0% +Market at that level of interest rate +despite the fact that output end up + + align:start position:0% +despite the fact that output end up + + + align:start position:0% +despite the fact that output end up +being higher than they thought so all + + align:start position:0% +being higher than they thought so all + + + align:start position:0% +being higher than they thought so all +this is a long winded way to say that + + align:start position:0% +this is a long winded way to say that + + + align:start position:0% +this is a long winded way to say that +the LM is the modern LM is + + align:start position:0% + + + + align:start position:0% + +horizontal a few years ago that curve + + align:start position:0% +horizontal a few years ago that curve + + + align:start position:0% +horizontal a few years ago that curve +would have been upward sloping but given + + align:start position:0% +would have been upward sloping but given + + + align:start position:0% +would have been upward sloping but given +the way monetary policy is conducted + + align:start position:0% +the way monetary policy is conducted + + + align:start position:0% +the way monetary policy is conducted +nowadays your life is a lot simpler the + + align:start position:0% +nowadays your life is a lot simpler the + + + align:start position:0% +nowadays your life is a lot simpler the +L is a horizontal curve okay the FED + + align:start position:0% +L is a horizontal curve okay the FED + + + align:start position:0% +L is a horizontal curve okay the FED +tells you the Central Bank tells you H + + align:start position:0% +tells you the Central Bank tells you H + + + align:start position:0% +tells you the Central Bank tells you H +what the interest rate has to be and + + align:start position:0% +what the interest rate has to be and + + + align:start position:0% +what the interest rate has to be and +then it will give whatever M will + + align:start position:0% +then it will give whatever M will + + + align:start position:0% +then it will give whatever M will +provide whatever m is needed so that's + + align:start position:0% +provide whatever m is needed so that's + + + align:start position:0% +provide whatever m is needed so that's +the equilibrium + + align:start position:0% + + + + align:start position:0% + +industry so what shift the modern LM + + align:start position:0% + + + + align:start position:0% + +and by modern I only mean the book + + align:start position:0% +and by modern I only mean the book + + + align:start position:0% +and by modern I only mean the book +doesn't use the terminology but by + + align:start position:0% +doesn't use the terminology but by + + + align:start position:0% +doesn't use the terminology but by +modern I mean that the FED decides what + + align:start position:0% +modern I mean that the FED decides what + + + align:start position:0% +modern I mean that the FED decides what +the interest it + + align:start position:0% +the interest it + + + align:start position:0% +the interest it +is exactly the only thing that will + + align:start position:0% +is exactly the only thing that will + + + align:start position:0% +is exactly the only thing that will +shift into to your life is very simple + + align:start position:0% +shift into to your life is very simple + + + align:start position:0% +shift into to your life is very simple +the only thing that will shift the mod + + align:start position:0% +the only thing that will shift the mod + + + align:start position:0% +the only thing that will shift the mod +LM is that the FED changes its + + align:start position:0% +LM is that the FED changes its + + + align:start position:0% +LM is that the FED changes its +mind a few years back it would have been + + align:start position:0% +mind a few years back it would have been + + + align:start position:0% +mind a few years back it would have been +more + + align:start position:0% +more + + + align:start position:0% +more +complicated a change in money demand + + align:start position:0% +complicated a change in money demand + + + align:start position:0% +complicated a change in money demand +a a change in money supply all those + + align:start position:0% +a a change in money supply all those + + + align:start position:0% +a a change in money supply all those +things will be Shifting the LM around + + align:start position:0% +things will be Shifting the LM around + + + align:start position:0% +things will be Shifting the LM around +now in this setup is very simple no it + + align:start position:0% +now in this setup is very simple no it + + + align:start position:0% +now in this setup is very simple no it +will change only if the feds changes his + + align:start position:0% +will change only if the feds changes his + + + align:start position:0% +will change only if the feds changes his +mind now obviously the FED is not just a + + align:start position:0% +mind now obviously the FED is not just a + + + align:start position:0% +mind now obviously the FED is not just a +moody institution it will change the + + align:start position:0% +moody institution it will change the + + + align:start position:0% +moody institution it will change the +mind and sometimes is forced to change + + align:start position:0% +mind and sometimes is forced to change + + + align:start position:0% +mind and sometimes is forced to change +its + + align:start position:0% +its + + + align:start position:0% +its +mind I mean they're not happy with the + + align:start position:0% +mind I mean they're not happy with the + + + align:start position:0% +mind I mean they're not happy with the +interest rate they're setting + + align:start position:0% +interest rate they're setting + + + align:start position:0% +interest rate they're setting +nowadays they' been forced into that + + align:start position:0% +nowadays they' been forced into that + + + align:start position:0% +nowadays they' been forced into that +were very reluctant to go into very high + + align:start position:0% +were very reluctant to go into very high + + + align:start position:0% +were very reluctant to go into very high +interest rate but you know what is + + align:start position:0% +interest rate but you know what is + + + align:start position:0% +interest rate but you know what is +happening around with very high + + align:start position:0% +happening around with very high + + + align:start position:0% +happening around with very high +consumption and the impact that it's + + align:start position:0% +consumption and the impact that it's + + + align:start position:0% +consumption and the impact that it's +having on inflation they have been + + align:start position:0% +having on inflation they have been + + + align:start position:0% +having on inflation they have been +forced into moving interest rate not + + align:start position:0% +forced into moving interest rate not + + + align:start position:0% +forced into moving interest rate not +only very high but also very fast and + + align:start position:0% +only very high but also very fast and + + + align:start position:0% +only very high but also very fast and +and and and uh that was very risky we + + align:start position:0% +and and and uh that was very risky we + + + align:start position:0% +and and and uh that was very risky we +have been lucky that that nothing has + + align:start position:0% +have been lucky that that nothing has + + + align:start position:0% +have been lucky that that nothing has +really broken when normally when central + + align:start position:0% +really broken when normally when central + + + align:start position:0% +really broken when normally when central +banks raise interest so fast they break + + align:start position:0% +banks raise interest so fast they break + + + align:start position:0% +banks raise interest so fast they break +something along the way somebody's very + + align:start position:0% +something along the way somebody's very + + + align:start position:0% +something along the way somebody's very +lever out there some bank or something + + align:start position:0% +lever out there some bank or something + + + align:start position:0% +lever out there some bank or something +like that and you can you can blow up + + align:start position:0% +like that and you can you can blow up + + + align:start position:0% +like that and you can you can blow up +the UK we had a little scare with some + + align:start position:0% +the UK we had a little scare with some + + + align:start position:0% +the UK we had a little scare with some +insurance companies but + + align:start position:0% +insurance companies but + + + align:start position:0% +insurance companies but +but but was for a different reason + + align:start position:0% +but but was for a different reason + + + align:start position:0% +but but was for a different reason +but but it's it's scary to move policy + + align:start position:0% +but but it's it's scary to move policy + + + align:start position:0% +but but it's it's scary to move policy +very fast because this is a very + + align:start position:0% +very fast because this is a very + + + align:start position:0% +very fast because this is a very +important price for financial markets + + align:start position:0% +important price for financial markets + + + align:start position:0% +important price for financial markets +everything in financial Market gets + + align:start position:0% +everything in financial Market gets + + + align:start position:0% +everything in financial Market gets +priced off that's a starting any pricing + + align:start position:0% +priced off that's a starting any pricing + + + align:start position:0% +priced off that's a starting any pricing +model for stocks for anything will start + + align:start position:0% +model for stocks for anything will start + + + align:start position:0% +model for stocks for anything will start +from that policy rate then everything + + align:start position:0% +from that policy rate then everything + + + align:start position:0% +from that policy rate then everything +builds from there so if this has to move + + align:start position:0% +builds from there so if this has to move + + + align:start position:0% +builds from there so if this has to move +fast you can have lots of + + align:start position:0% +fast you can have lots of + + + align:start position:0% +fast you can have lots of +dislocation so my goal for today is to + + align:start position:0% +dislocation so my goal for today is to + + + align:start position:0% +dislocation so my goal for today is to +just to give you the instr and then + + align:start position:0% +just to give you the instr and then + + + align:start position:0% +just to give you the instr and then +we're going to all talk about + + align:start position:0% +we're going to all talk about + + + align:start position:0% +we're going to all talk about +combinations things that we did in + + align:start position:0% +combinations things that we did in + + + align:start position:0% +combinations things that we did in +certain episodes and and things of that + + align:start position:0% +certain episodes and and things of that + + + align:start position:0% +certain episodes and and things of that +kind okay good so again this part of the + + align:start position:0% +kind okay good so again this part of the + + + align:start position:0% +kind okay good so again this part of the +course is this part of the of the ISL + + align:start position:0% +course is this part of the of the ISL + + + align:start position:0% +course is this part of the of the ISL +mod is very easy and it's a lot easier + + align:start position:0% +mod is very easy and it's a lot easier + + + align:start position:0% +mod is very easy and it's a lot easier +now than it was a few years back okay so + + align:start position:0% +now than it was a few years back okay so + + + align:start position:0% +now than it was a few years back okay so +what does the eslm mo the slm M me + + align:start position:0% +what does the eslm mo the slm M me + + + align:start position:0% +what does the eslm mo the slm M me +simply mean puts the two curves together + + align:start position:0% +simply mean puts the two curves together + + + align:start position:0% +simply mean puts the two curves together +now we have two Curves in the space of + + align:start position:0% +now we have two Curves in the space of + + + align:start position:0% +now we have two Curves in the space of +output and interest rate and two + + align:start position:0% +output and interest rate and two + + + align:start position:0% +output and interest rate and two +unknowns which is output and interest + + align:start position:0% +unknowns which is output and interest + + + align:start position:0% +unknowns which is output and interest +rate + + align:start position:0% + + + + align:start position:0% + +so we have one combination only a that + + align:start position:0% +so we have one combination only a that + + + align:start position:0% +so we have one combination only a that +is consistent with both equilibrium in + + align:start position:0% +is consistent with both equilibrium in + + + align:start position:0% +is consistent with both equilibrium in +the Goods Market and equilibrium in + + align:start position:0% +the Goods Market and equilibrium in + + + align:start position:0% +the Goods Market and equilibrium in +financial Market that's the point + + align:start position:0% +financial Market that's the point + + + align:start position:0% +financial Market that's the point +a + + align:start position:0% +a + + + align:start position:0% +a +okay what happens to points to the right + + align:start position:0% +okay what happens to points to the right + + + align:start position:0% +okay what happens to points to the right +suppose I I I what happen What Happens + + align:start position:0% +suppose I I I what happen What Happens + + + align:start position:0% +suppose I I I what happen What Happens +here if I show you this point in this + + align:start position:0% + + + + align:start position:0% + +space what what's wrong with that + + align:start position:0% + + + + align:start position:0% + +point so point to the a point along the + + align:start position:0% +point so point to the a point along the + + + align:start position:0% +point so point to the a point along the +lamp but to the right what's wrong + + align:start position:0% + + + + align:start position:0% + +there well if it is along the LM I know + + align:start position:0% +there well if it is along the LM I know + + + align:start position:0% +there well if it is along the LM I know +that I'm okay with financial Market that + + align:start position:0% +that I'm okay with financial Market that + + + align:start position:0% +that I'm okay with financial Market that +those points are consistent with + + align:start position:0% +those points are consistent with + + + align:start position:0% +those points are consistent with +equilibrium in financial + + align:start position:0% +equilibrium in financial + + + align:start position:0% +equilibrium in financial +Market but it's not my equilibrium and + + align:start position:0% +Market but it's not my equilibrium and + + + align:start position:0% +Market but it's not my equilibrium and +it has to be in consistent with the + + align:start position:0% +it has to be in consistent with the + + + align:start position:0% +it has to be in consistent with the +other one it's not consistent with + + align:start position:0% +other one it's not consistent with + + + align:start position:0% +other one it's not consistent with +equilibrium in the Goods Market in fact + + align:start position:0% +equilibrium in the Goods Market in fact + + + align:start position:0% +equilibrium in the Goods Market in fact +you know more than that what's wrong + + align:start position:0% +you know more than that what's wrong + + + align:start position:0% +you know more than that what's wrong +with Goods Market there's an imbalance + + align:start position:0% +with Goods Market there's an imbalance + + + align:start position:0% +with Goods Market there's an imbalance +there but in which + + align:start position:0% + + + + align:start position:0% + +direction that point + + align:start position:0% + + + + align:start position:0% + +here what do you mean by excess of + + align:start position:0% + + + + align:start position:0% + +goods no demand is exactly insufficient + + align:start position:0% +goods no demand is exactly insufficient + + + align:start position:0% +goods no demand is exactly insufficient +demand there's too much output for that + + align:start position:0% +demand there's too much output for that + + + align:start position:0% +demand there's too much output for that +demand so that's the reason it's not + + align:start position:0% +demand so that's the reason it's not + + + align:start position:0% +demand so that's the reason it's not +consistent with equilibrium in the Goods + + align:start position:0% +consistent with equilibrium in the Goods + + + align:start position:0% +consistent with equilibrium in the Goods +Market okay to the left is the opposite + + align:start position:0% +Market okay to the left is the opposite + + + align:start position:0% +Market okay to the left is the opposite +no to the left we have insufficient + + align:start position:0% +no to the left we have insufficient + + + align:start position:0% +no to the left we have insufficient +output for the demand we have so it's + + align:start position:0% +output for the demand we have so it's + + + align:start position:0% +output for the demand we have so it's +not consistent with equilibrium in the + + align:start position:0% +not consistent with equilibrium in the + + + align:start position:0% +not consistent with equilibrium in the +the Goods Market so the only point that + + align:start position:0% +the Goods Market so the only point that + + + align:start position:0% +the Goods Market so the only point that +is consistent oh well you can think what + + align:start position:0% +is consistent oh well you can think what + + + align:start position:0% +is consistent oh well you can think what +happens with a point here for + + align:start position:0% +happens with a point here for + + + align:start position:0% +happens with a point here for +example that point because it's in the + + align:start position:0% +example that point because it's in the + + + align:start position:0% +example that point because it's in the +curve is consistent with equilibrium in + + align:start position:0% +curve is consistent with equilibrium in + + + align:start position:0% +curve is consistent with equilibrium in +the Goods Market but it's not consistent + + align:start position:0% +the Goods Market but it's not consistent + + + align:start position:0% +the Goods Market but it's not consistent +with equilibrium in Financial Market + + align:start position:0% +with equilibrium in Financial Market + + + align:start position:0% +with equilibrium in Financial Market +okay what do we have there supposed + + align:start position:0% +okay what do we have there supposed + + + align:start position:0% +okay what do we have there supposed +having in that point the interest rate + + align:start position:0% +having in that point the interest rate + + + align:start position:0% +having in that point the interest rate +is too high so that means the money + + align:start position:0% +is too high so that means the money + + + align:start position:0% +is too high so that means the money +demand is low so too much money demand + + align:start position:0% +demand is low so too much money demand + + + align:start position:0% +demand is low so too much money demand +for money supply okay that's that's what + + align:start position:0% +for money supply okay that's that's what + + + align:start position:0% +for money supply okay that's that's what +you have so those are not so so that's + + align:start position:0% +you have so those are not so so that's + + + align:start position:0% +you have so those are not so so that's +at the end of the day you know this is + + align:start position:0% +at the end of the day you know this is + + + align:start position:0% +at the end of the day you know this is +the only equilibrium point we have and + + align:start position:0% +the only equilibrium point we have and + + + align:start position:0% +the only equilibrium point we have and +and all the experiments I want to do + + align:start position:0% +and all the experiments I want to do + + + align:start position:0% +and all the experiments I want to do +next have to do with moving one curve or + + align:start position:0% +next have to do with moving one curve or + + + align:start position:0% +next have to do with moving one curve or +the other and see what happens to trace + + align:start position:0% +the other and see what happens to trace + + + align:start position:0% +the other and see what happens to trace +new equilibrium points okay but try to + + align:start position:0% +new equilibrium points okay but try to + + + align:start position:0% +new equilibrium points okay but try to +understand + + align:start position:0% +understand + + + align:start position:0% +understand +very well these diagrams of what + + align:start position:0% +very well these diagrams of what + + + align:start position:0% +very well these diagrams of what +happens when I move up horizontally and + + align:start position:0% +happens when I move up horizontally and + + + align:start position:0% +happens when I move up horizontally and +so on and convince yourself that this is + + align:start position:0% +so on and convince yourself that this is + + + align:start position:0% +so on and convince yourself that this is +the only combination it's pretty easy to + + align:start position:0% +the only combination it's pretty easy to + + + align:start position:0% +the only combination it's pretty easy to +convince yourself it's the only + + align:start position:0% +convince yourself it's the only + + + align:start position:0% +convince yourself it's the only +combination but think a little try to + + align:start position:0% +combination but think a little try to + + + align:start position:0% +combination but think a little try to +get away from point A and see what + + align:start position:0% +get away from point A and see what + + + align:start position:0% +get away from point A and see what +happens I guess the best way to do that + + align:start position:0% +happens I guess the best way to do that + + + align:start position:0% +happens I guess the best way to do that +is just to do experiment meaning move + + align:start position:0% +is just to do experiment meaning move + + + align:start position:0% +is just to do experiment meaning move +parameters of these curves and see how + + align:start position:0% +parameters of these curves and see how + + + align:start position:0% +parameters of these curves and see how +equilibrium output changes and so + + align:start position:0% + + + + align:start position:0% + +on so let's do the first + + align:start position:0% +on so let's do the first + + + align:start position:0% +on so let's do the first +experiment and yeah + + align:start position:0% +experiment and yeah + + + align:start position:0% +experiment and yeah +maybe so let's let's let's play with + + align:start position:0% +maybe so let's let's let's play with + + + align:start position:0% +maybe so let's let's let's play with +this so now you have you have your model + + align:start position:0% +this so now you have you have your model + + + align:start position:0% +this so now you have you have your model +and now we can start asking interesting + + align:start position:0% +and now we can start asking interesting + + + align:start position:0% +and now we can start asking interesting +questions the first thing you can ask is + + align:start position:0% +questions the first thing you can ask is + + + align:start position:0% +questions the first thing you can ask is +well fiscal policy how does it + + align:start position:0% +well fiscal policy how does it + + + align:start position:0% +well fiscal policy how does it +work + + align:start position:0% +work + + + align:start position:0% +work +well + + align:start position:0% +well + + + align:start position:0% +well +sorry so here this this is a contraction + + align:start position:0% +sorry so here this this is a contraction + + + align:start position:0% +sorry so here this this is a contraction +in fiscal policy so the same as we did + + align:start position:0% +in fiscal policy so the same as we did + + + align:start position:0% +in fiscal policy so the same as we did +before remember we increase taxes or we + + align:start position:0% +before remember we increase taxes or we + + + align:start position:0% +before remember we increase taxes or we +could have reduced go expenditure + + align:start position:0% +could have reduced go expenditure + + + align:start position:0% +could have reduced go expenditure +whatever that would have shifted the we + + align:start position:0% +whatever that would have shifted the we + + + align:start position:0% +whatever that would have shifted the we +we did that when when we look at the we + + align:start position:0% +we did that when when we look at the we + + + align:start position:0% +we did that when when we look at the we +did exactly that we shift the to to to + + align:start position:0% +did exactly that we shift the to to to + + + align:start position:0% +did exactly that we shift the to to to +the left and what happens here is well + + align:start position:0% +the left and what happens here is well + + + align:start position:0% +the left and what happens here is well +if you shift the to the left there's a + + align:start position:0% +if you shift the to the left there's a + + + align:start position:0% +if you shift the to the left there's a +new combination of output and interest + + align:start position:0% +new combination of output and interest + + + align:start position:0% +new combination of output and interest +rate that is that is consistent with + + align:start position:0% +rate that is that is consistent with + + + align:start position:0% +rate that is that is consistent with +equilibrium both markets that's a lower + + align:start position:0% +equilibrium both markets that's a lower + + + align:start position:0% +equilibrium both markets that's a lower +output okay so if the FED doesn't do + + align:start position:0% +output okay so if the FED doesn't do + + + align:start position:0% +output okay so if the FED doesn't do +anything that means it keeps the LM + + align:start position:0% +anything that means it keeps the LM + + + align:start position:0% +anything that means it keeps the LM +there and there's a contractionary + + align:start position:0% +there and there's a contractionary + + + align:start position:0% +there and there's a contractionary +fiscal policy well that will lead to + + align:start position:0% +fiscal policy well that will lead to + + + align:start position:0% +fiscal policy well that will lead to +contraction in output as well that's the + + align:start position:0% +contraction in output as well that's the + + + align:start position:0% +contraction in output as well that's the +reason we call it contraction not only + + align:start position:0% +reason we call it contraction not only + + + align:start position:0% +reason we call it contraction not only +because fiscal not not only because + + align:start position:0% +because fiscal not not only because + + + align:start position:0% +because fiscal not not only because +govern expenditure decline but it's if + + align:start position:0% +govern expenditure decline but it's if + + + align:start position:0% +govern expenditure decline but it's if +taxes increase that's contractionary + + align:start position:0% +taxes increase that's contractionary + + + align:start position:0% +taxes increase that's contractionary +because it reduces aggregate demand and + + align:start position:0% +because it reduces aggregate demand and + + + align:start position:0% +because it reduces aggregate demand and +the equilibrium that will reduce output + + align:start position:0% + + + + align:start position:0% + +okay so that's canonical contractionary + + align:start position:0% +okay so that's canonical contractionary + + + align:start position:0% +okay so that's canonical contractionary +fiscal policy you move output to the + + align:start position:0% +fiscal policy you move output to the + + + align:start position:0% +fiscal policy you move output to the +left interest rate doesn't move because + + align:start position:0% +left interest rate doesn't move because + + + align:start position:0% +left interest rate doesn't move because +that's controlled by the FED but but + + align:start position:0% +that's controlled by the FED but but + + + align:start position:0% +that's controlled by the FED but but +output declines okay so if somebody ask + + align:start position:0% +output declines okay so if somebody ask + + + align:start position:0% +output declines okay so if somebody ask +you what happens if if if there's a + + align:start position:0% +you what happens if if if there's a + + + align:start position:0% +you what happens if if if there's a +fiscal contraction you were asking a bit + + align:start position:0% +fiscal contraction you were asking a bit + + + align:start position:0% +fiscal contraction you were asking a bit +the the opposite side you know that + + align:start position:0% +the the opposite side you know that + + + align:start position:0% +the the opposite side you know that +people may have spent we have perhaps a + + align:start position:0% +people may have spent we have perhaps a + + + align:start position:0% +people may have spent we have perhaps a +fiscal expansion that was very large but + + align:start position:0% +fiscal expansion that was very large but + + + align:start position:0% +fiscal expansion that was very large but +what happens with a fiscal contraction + + align:start position:0% +what happens with a fiscal contraction + + + align:start position:0% +what happens with a fiscal contraction +well that will lead to lower equilibrium + + align:start position:0% +well that will lead to lower equilibrium + + + align:start position:0% +well that will lead to lower equilibrium +output I keep pring the lower equ what + + align:start position:0% +output I keep pring the lower equ what + + + align:start position:0% +output I keep pring the lower equ what +happens if you have a very large fiscal + + align:start position:0% +happens if you have a very large fiscal + + + align:start position:0% +happens if you have a very large fiscal +expansion what what happens if you have + + align:start position:0% +expansion what what happens if you have + + + align:start position:0% +expansion what what happens if you have +a very large fysical + + align:start position:0% +a very large fysical + + + align:start position:0% +a very large fysical +expansion what moves Ah that's something + + align:start position:0% +expansion what moves Ah that's something + + + align:start position:0% +expansion what moves Ah that's something +that's you should that's a question you + + align:start position:0% +that's you should that's a question you + + + align:start position:0% +that's you should that's a question you +should always ask yourself when when + + align:start position:0% +should always ask yourself when when + + + align:start position:0% +should always ask yourself when when +there is any question + + align:start position:0% +there is any question + + + align:start position:0% +there is any question +islm of islm you should ask which curve + + align:start position:0% +islm of islm you should ask which curve + + + align:start position:0% +islm of islm you should ask which curve +moves start from that always okay so if + + align:start position:0% +moves start from that always okay so if + + + align:start position:0% +moves start from that always okay so if +if we ask you any question about that is + + align:start position:0% +if we ask you any question about that is + + + align:start position:0% +if we ask you any question about that is +obvious about aslm the first thing you + + align:start position:0% +obvious about aslm the first thing you + + + align:start position:0% +obvious about aslm the first thing you +should ask is which Curve will + + align:start position:0% +should ask is which Curve will + + + align:start position:0% +should ask is which Curve will +move + + align:start position:0% +move + + + align:start position:0% +move +so suppose I tell you + + align:start position:0% +so suppose I tell you + + + align:start position:0% +so suppose I tell you +um due to covid the covid shock there + + align:start position:0% +um due to covid the covid shock there + + + align:start position:0% +um due to covid the covid shock there +was a massive ER transfer + + align:start position:0% +was a massive ER transfer + + + align:start position:0% +was a massive ER transfer +income transfer to lowincome individuals + + align:start position:0% +income transfer to lowincome individuals + + + align:start position:0% +income transfer to lowincome individuals +that is we had a very expansionary + + align:start position:0% +that is we had a very expansionary + + + align:start position:0% +that is we had a very expansionary +fiscal + + align:start position:0% +fiscal + + + align:start position:0% +fiscal +policy first thing you should ask is + + align:start position:0% +policy first thing you should ask is + + + align:start position:0% +policy first thing you should ask is +okay which curve moves the LM or the is + + align:start position:0% +okay which curve moves the LM or the is + + + align:start position:0% +okay which curve moves the LM or the is +if I do + + align:start position:0% +if I do + + + align:start position:0% +if I do +that is the is shift to the right does + + align:start position:0% +that is the is shift to the right does + + + align:start position:0% +that is the is shift to the right does +the LM move no has nothing to do with + + align:start position:0% +the LM move no has nothing to do with + + + align:start position:0% +the LM move no has nothing to do with +monetary policy + + align:start position:0% +monetary policy + + + align:start position:0% +monetary policy +okay so that's the first thing you need + + align:start position:0% +okay so that's the first thing you need + + + align:start position:0% +okay so that's the first thing you need +to do which curve is + + align:start position:0% +to do which curve is + + + align:start position:0% +to do which curve is +moving okay if it is fiscal that's a + + align:start position:0% +moving okay if it is fiscal that's a + + + align:start position:0% +moving okay if it is fiscal that's a +Goods Market thing that means it's going + + align:start position:0% +Goods Market thing that means it's going + + + align:start position:0% +Goods Market thing that means it's going +to move the yes not the + + align:start position:0% + + + + align:start position:0% + +LM what is the mechanism here what + + align:start position:0% +LM what is the mechanism here what + + + align:start position:0% +LM what is the mechanism here what +happened + + align:start position:0% +happened + + + align:start position:0% +happened +well remember what we have is I told you + + align:start position:0% +well remember what we have is I told you + + + align:start position:0% +well remember what we have is I told you +go always back to this diagram if you + + align:start position:0% +go always back to this diagram if you + + + align:start position:0% +go always back to this diagram if you +increase taxes and you keep keep the + + align:start position:0% +increase taxes and you keep keep the + + + align:start position:0% +increase taxes and you keep keep the +interest rate constant and you start + + align:start position:0% +interest rate constant and you start + + + align:start position:0% +interest rate constant and you start +from there so so the interest rate + + align:start position:0% +from there so so the interest rate + + + align:start position:0% +from there so so the interest rate +doesn't move then that will do what what + + align:start position:0% +doesn't move then that will do what what + + + align:start position:0% +doesn't move then that will do what what +increasing taxes did in lecture three + + align:start position:0% +increasing taxes did in lecture three + + + align:start position:0% +increasing taxes did in lecture three +will reduce aggregate demand and then + + align:start position:0% +will reduce aggregate demand and then + + + align:start position:0% +will reduce aggregate demand and then +the multiplier will take us to a larger + + align:start position:0% +the multiplier will take us to a larger + + + align:start position:0% +the multiplier will take us to a larger +decline that the initial fiscal + + align:start position:0% +decline that the initial fiscal + + + align:start position:0% +decline that the initial fiscal +contraction okay and that's a decline in + + align:start position:0% +contraction okay and that's a decline in + + + align:start position:0% +contraction okay and that's a decline in +equilibrium output so that y1 there is + + align:start position:0% +equilibrium output so that y1 there is + + + align:start position:0% +equilibrium output so that y1 there is +exactly a this one + + align:start position:0% +exactly a this one + + + align:start position:0% +exactly a this one +here that y Prime okay I haven't moved + + align:start position:0% +here that y Prime okay I haven't moved + + + align:start position:0% +here that y Prime okay I haven't moved +the interest rate I kept it at the same + + align:start position:0% +the interest rate I kept it at the same + + + align:start position:0% +the interest rate I kept it at the same +level I had a fysical + + align:start position:0% +level I had a fysical + + + align:start position:0% +level I had a fysical +contraction that's what we describe with + + align:start position:0% +contraction that's what we describe with + + + align:start position:0% +contraction that's what we describe with +that diagram well that's my new is I + + align:start position:0% +that diagram well that's my new is I + + + align:start position:0% +that diagram well that's my new is I +have a new + + align:start position:0% +have a new + + + align:start position:0% +have a new +is because for any for the same interest + + align:start position:0% +is because for any for the same interest + + + align:start position:0% +is because for any for the same interest +rate I have a lower equilibrium output + + align:start position:0% +rate I have a lower equilibrium output + + + align:start position:0% +rate I have a lower equilibrium output +and it happens that the FED DM change + + align:start position:0% +and it happens that the FED DM change + + + align:start position:0% +and it happens that the FED DM change +the interest rate so that's going to be + + align:start position:0% +the interest rate so that's going to be + + + align:start position:0% +the interest rate so that's going to be +my equilibrium output the whole curve + + align:start position:0% +my equilibrium output the whole curve + + + align:start position:0% +my equilibrium output the whole curve +moved to the left that would could tell + + align:start position:0% +moved to the left that would could tell + + + align:start position:0% +moved to the left that would could tell +three slides ago but now I know more I + + align:start position:0% +three slides ago but now I know more I + + + align:start position:0% +three slides ago but now I know more I +also know that since the FED hasn't + + align:start position:0% +also know that since the FED hasn't + + + align:start position:0% +also know that since the FED hasn't +reacted I I know exactly what is the new + + align:start position:0% +reacted I I know exactly what is the new + + + align:start position:0% +reacted I I know exactly what is the new +equilibrium output which is this I don't + + align:start position:0% +equilibrium output which is this I don't + + + align:start position:0% +equilibrium output which is this I don't +before we could only tell that the curve + + align:start position:0% +before we could only tell that the curve + + + align:start position:0% +before we could only tell that the curve +has shift to the left now since the fan + + align:start position:0% +has shift to the left now since the fan + + + align:start position:0% +has shift to the left now since the fan +react to that fiscal contraction I also + + align:start position:0% +react to that fiscal contraction I also + + + align:start position:0% +react to that fiscal contraction I also +know the equilibrium output will end up + + align:start position:0% +know the equilibrium output will end up + + + align:start position:0% +know the equilibrium output will end up +at White Prim okay good so I'm want to + + align:start position:0% +at White Prim okay good so I'm want to + + + align:start position:0% +at White Prim okay good so I'm want to +stop here and and and in the next + + align:start position:0% +stop here and and and in the next + + + align:start position:0% +stop here and and and in the next +lecture we'll + + align:start position:0% +lecture we'll + + + align:start position:0% +lecture we'll +continue with this \ No newline at end of file diff --git a/r9Jwtxf4SA0.txt b/r9Jwtxf4SA0.txt new file mode 100644 index 0000000000000000000000000000000000000000..390c7d2fba4766dcd1246fb5aefbdbef08eef7c2 --- /dev/null +++ b/r9Jwtxf4SA0.txt @@ -0,0 +1,1158 @@ +ANNOUNCER: The following content +is provided under a + +Creative Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation, or to view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: Hi. + +Our lesson today is called +the 'Inverse Logarithm'. + +And what it will do, among other +things, is give us a + +very nice chance to revisit +inverse functions in general, + +only now applied specifically +to the natural logarithm + +function that we talked +about last time. + +So I call today's lesson, as I +say, 'Inverse Logarithms'. + +And to see what's coming up +here, simply recall that last + +time, we invented, so to speak, +a new function called + +the 'natural log of x'. + +This had nothing to +do with exponents. + +It was what? + +This was the function whose +derivative with respect to 'x' + +was '1/x' and passed through +the point (1 , 0). + +That uniquely defined this +particular function. + +The point being what? + +That this particular function, +since the domain is for + +positive 'x', '1/x' +is positive. + +The curve is always rising, +which means that the function + +itself must be one to one. + +And because the function is one +to one, it means that the + +inverse function exists. + +This is no different from any +other example of forming f + +inverse, given a one to one +function called 'f'. + +So what we do is now, +and remember how + +you invert this function. + +If you want to do this thing +in slow motion, you first + +rotate this through 90 degrees, +then flip it over. + +If you want to do it faster, the +inverse graph of this is + +the reflection of this curve +with respect to the line 'y' + +equals 'x'. + +In any event, if we do this, we +find that the graph of the + +function 'y' equals +'inverse log x' is + +this particular curve. + +And notice the correspondence. + +If this is the point (1 , 0) on +the log curve, the inverse + +point is (0 , 1). + +In other words, the inverse +log of 0 is 1. + +OK. + +Now, the idea is something +like this. + +Just to have a review, +again, of how-- + +see, the punchline I want to +make for today's lesson, right + +at the beginning, is that the +nice thing about studying + +inverse functions is that once +you know the function of which + +you're taking the inverse, you +automatically get all the + +mileage you want out of +the inverse function. + +Well, by way of illustration, +if the function natural log + +had the usual logarithmic +property, we would suspect + +that its inverse +should have the + +usual exponential property. + +Now what is the usual +exponential property? + +The exponential function is +characterized by what? + +That if you take 'f of 'x1 plus +x2'', that's 'f of x1' + +times 'f of x2'. + +So you think of it +in terms of the + +usual exponential notation. + +If you have, say, 10 raised to +the 'x1 plus x2' power, that's + +the same as 10 to the +'x1' power times + +10 to the 'x2' power. + +In other words, if our ln +function is genuinely a + +logarithmic function, we would +expect the inverse of that + +function to be a genuine +exponential function. + +And just to work with inverses +again, let's see if this is + +indeed true. + +Let's see if it's really true +that the 'inverse log of 'x1 + +plus x2'' is the 'inverse +log of x1' times the + +'inverse log of x2'. + +You see, the whole +idea is what? + +Let's give these things names. + +Let 'y1' be the 'inverse log +of x1' and 'y2' be the + +'inverse log of x2'. + +Now, since we've already +studied the natural log + +function, the most natural thing +to do here is to invert + +these, namely 'y1' equals the +inverse 'natural log of x1' is + +the same as saying 'x1' is +the 'natural log of y1'. + +And similarly, this is the same +as saying that 'x2' is + +the 'natural log of y2'. + +And now we add equals to equals, +and we get that 'x1 + +plus x2' is 'natural log y1' +plus 'natural log y2'. + +But allegedly, we understand the +properties of the natural + +log, because if we didn't +understand those, it would be + +kind of futile to be studying +the inverse function. + +What do we know about +the natural log? + +We know that the 'natural +log of 'y1 times y2', by + +definition of a logarithmic +function, is 'log + +y1' plus 'log y2'. + +In other words, 'natural log y1' +plus 'natural log y2', by + +the property of being +logarithmic, is just the + +'natural log of 'y1 +times y2''. + +And now, taking this +relationship and inverting it + +to say this is the same +as saying what? + +The 'inverse natural log of 'x1 +plus x2'' is equal to 'y1' + +times 'y2'. + +And if we now observe that 'y1' +was the 'inverse natural + +log of x1', and 'y2' is the +'inverse natural log of x2', + +we have the result that we +claimed we would have at the + +beginning here. + +Now again, here's one example +where it's not the result that + +I'm not interested in. + +But I'm interested in showing, +again, what we meant when we + +said that once we learn a new +concept, we can bring to it + +all of our old knowledge. + +You see, all of these things +come from our basic + +definition. + +Well, let's carry on +one step further. + +You see, this was an arithmetic +property. + +Let's see if we can get some +calculus properties about the + +inverse natural log based on our +knowledge of the natural + +log itself. + +Well, for example, in a course +of this type, the most natural + +thing to do, I guess, is given +any function, we would always + +like to be able to talk about +its derivative, provided, of + +course, the function +is differentiable. + +So for example, a typical +question that one might ask is + +find 'dy dx', if 'y' is 'inverse +natural log x'. + +Again, this works the same way +as it did for the inverse trig + +functions, for the inverse of +everything that we've done so + +far in this course. + +We start with this particular +relationship and right away + +translate it into that which +we're more familiar with, + +namely we translate 'y' equals +the 'inverse natural log of x' + +into 'x' equals 'natural +log y'. + +Now you see again, since I know +how to differentiate 'log + +y' with respect to 'y', the +derivative of 'natural log y' + +with respect to 'y' was +by definition '1/y'. + +From this relationship +here, I can find + +that 'dx dy' is '1/y'. + +And knowing that 'dx dy' is +'1/y', using my inverse + +function general theory that +tells me that to find the + +derivative of 'y' with respect +to 'x', all I have to do is + +invert the derivative of 'x' +with respect to 'y', I wind up + +with the fact that 'dy dx' +is equal to 'y' itself. + +In other words, the 'inverse +log x' function is + +characterized by the fact that +it's its own derivative. + +In other words, it's a +non-destructible type of + +function with respect +to differentiation. + +This is a rather powerful +property. + +You see what this thing says? + +It says that the derivative +of 'y' with respect + +to 'x' is 'y' itself. + +By the way, just as an aside, we +can do the converse of this + +particular problem. + +You see, we started with 'y' +equals 'inverse log x' and + +showed that this particular +equation was satisfied. + +Notice that if we start with +this particular equation, + +starting with 'dy dx' equals +'y', separate the variables, + +and lo and behold, we wind up +with 'dy over y' equals 'dx'. + +And without carrying out the +details, I leave this to you, + +because it is straightforward. + +Notice that as we look at the +left hand side here, we + +hopefully will think +immediately + +of the natural logarithm. + +Namely, what do we want here? + +The function whose derivative +with respect to 'y' is '1/y'. + +Again, you see what I'm saying +is notice that if we had + +started with this particular +differential equation, we + +could have shown that a +logarithm, and hence solving + +for 'y' explicitly, would +have led to the + +inverse logarithm also. + +But at any rate, notice then +that we can find the + +derivative of the inverse log +just by knowing how to find + +the derivative of the natural +log itself, which is as we + +expect things should be. + +Again, and this is a notational +thing, we do not + +use the language in general +"inverse log x." + +In other words, it's quite +conventional to talk about + +'inverse sine x'. + +You may notice that sometimes +in the text, sometimes in my + +lectures I may have used +the word 'arcsin x'. + +But the general notation +is sine to the minus 1. + +However, when it comes to the +natural logarithm function, + +the inverse is usually +not written as + +'inverse natural log x'. + +It's usually abbreviated, and +let me say this, by the symbol + +'e to the x'. + +Now the reason I say by +the symbol is this. + +If I wanted to, I can say, look, +If I've never heard of + +exponents before, let this +symbol be an abbreviation for + +'inverse log x'. + +Does 'inverse log x' exists? + +Yes, I even drew the graph of +it at the beginning of this + +particular lecture. + +However, again, if you are +tempted to use exponents, the + +notation 'e to the x' is in +keeping in line with the idea + +of our previous lecture. + +I say what? + +This matches the identification +of 'natural log + +x' with the 'log of x' +to the base 'e'. + +Remember, in our previous +lecture, we mentioned that + +this particular function exists +without having to talk + +about a base. + +But if you wanted to identify +it with a traditional + +logarithm, the base you would +have to pick is the base 'e', + +where we showed that 'e' was +some number between 2 and 4. + +In other words, again, it's just +like our 'dy dx' versus + +'dy' divided by 'dx' and +other symbols that we + +invented this way. + +Namely, if I look at 'e to the +x' as being the inverse of the + +natural log, or whether I look +at it as being 'e' raised to + +the 'x' power, where 'e' is that +number that's someplace + +between 2 and 4, I don't get +into any trouble either way + +because of the natural +identification of choosing e + +to be the base of my system. + +But I just mention +that in passing. + +Now you see, the rest +of today's lecture + +will go fairly quickly. + +And the reason that it will go +fairly quickly is that once + +we've established what the +function is that we're talking + +about, every other property of +that function is going to + +follow from the principles that +we've already learned. + +For example, in terms of our +new notation, since the + +derivative of 'e to the x' with +respect to 'x' is 'e to + +the x' itself, remember, +'e to the x' now can + +be viewed as what? + +'e to the x' power, or, to be on +safer grounds, if you want + +to be consistent, it's just an +abbreviation for 'inverse + +natural log x'. + +But at any rate, if 'u' is now +any differentiable function of + +'x', notice that to find the +derivative of 'e to the u' + +with respect to 'x', by the +chain rule, I can say what? + +It's the derivative of 'e to +the u' with respect to 'u' + +times 'du dx'. + +We've just shown that the +derivative of 'e to the u' + +with respect to 'u' is +'e' to the 'u' again. + +And therefore, the derivative +of 'e to the u' with respect + +to 'x' is 'e to the +u' times 'du dx'. + +By the way, this again leads to +another interesting thing + +that makes integrals tough +to handle, in a way. + +We've mentioned this before, +but here's another nice, + +natural environment to bring +this problem up in again. + +When we discussed the second +fundamental theorem of + +integral calculus to show how +one actually would have to + +understand areas to be able +to find a function whose + +derivative was 'e to the +'minus x squared', we + +mentioned, we didn't prove it, +we mentioned that there was no + +familiar function whose +derivative with respect to 'x' + +was 'e to the 'minus +x squared'. + +So this would be a very +difficult problem to handle. + +Now, let's look at +this one instead. + +Let's look at integral '2x 'e +to the minus x squared' dx'. + +To the untrained eye, it would +appear that this is even + +messier than this. + +In other words, this is just 'e +to the 'minus x squared''. + +This one has 'e to the 'minus +x squared'' with a '2x' + +dangling in front of it, and +that looks even tougher. + +But notice that if we look +at our exponent, 'minus x + +squared', the derivative, or the +differential of 'minus x + +squared' is what? + +It's 'minus '2x dx''. + +In other words, the '2x dx' is +precisely what you need to + +reduce this to the form integral +''e to the u' du'. + +In other words, working this +thing out in more specific + +detail, if I let 'u' equal +'minus x squared', 'du' + +becomes 'minus '2x dx'', and +therefore integral '2x 'e to + +the 'minus x squared'' dx' +just becomes what? + +Well, the 'e to the 'minus x +squared'' just becomes 'e to + +the minus u'. + +And '2x dx' is just +'minus du'. + +OK? + +I'm sorry, 'u' is 'minus +x squared'. + +'u' is 'minus x squared'. + +So 'minus x squared' is 'u'. + +So this becomes 'minus +e to the 'u du''. + +And that, of course, +is just minus. + +See, the minus will +come outside. + +The integral of 'e to the u' +with respect to 'u' is + +just 'e to the u'. + +And since 'u' is equal to 'minus +x squared', all we're + +saying is that if you +differentiate minus 'e' to the + +'minus x squared', you +wind up with what? + +'2x 'e to the 'minus x +squared'', the reason being + +that you must multiply this by +the derivative of the exponent + +with respect to 'x'. + +The root of the exponent +is 'minus 2x'. + +'Minus 2x' times minus +1 is '2x'. + +If you want to see this in +more concise differential + +notation, you see, what we're +saying is that the integral of + +'e' to some power with respect +to that same power is 'e' to + +that power plus a constant. + +In other words, the function +that one would have to + +integrate 'e to the 'minus x +squared'' with respect to to + +wind up with 'e to the 'minus x +squared'' would be 'minus x + +squared' itself. + +And you see, now, in the next +step, since this is a true + +statement, the differential +of 'minus x squared' + +is minus '2x dx'. + +And now you see, factoring out +the minus sign and multiplying + +through by minus 1, we arrive +at the same result that we + +wound up with before. + +But again, this is the kind of +material that we can drill on + +extensively in the exercises +in this particular unit. + +The technique is what? + +That the basic building block +of the so-called exponential + +function, the inverse natural +log, is that when you + +differentiate it, you +essentially do not destroy it. + +In other words, the derivative +of 'e to the u' with respect + +to 'x' is 'e to the +u' times 'du dx'. + +And I thought that in closing +today's lesson, I might as + +well show you a very powerful +application of this particular + +result in a non-obvious +situation. + +And it's something that +we call second-order + +differential equations. + +I've picked out here a +differential equation. + +Let me just show you what I +have in mind over here. + +Suppose I tell you that 'y' +is a twice-differentiable + +function of 'x' that satisfies +the following identity, that + +the second derivative of 'y' +with respect to 'x' minus 5 + +times the first derivative of +'y' with respect to 'x' plus 6 + +times 'y' is identically 0. + +And the question is, if this +equation is to be obeyed, what + +must 'y' be? + +And a very interesting technique +for solving this + +kind of a problem, you see, this +is called a second-order + +differential equation because +the highest derivative that + +appears is the second +derivative. + +OK, a rather powerful +technique using the + +exponential is available to us +for problems of this sort. + +And the idea hinges on this. + +As a trial solution, which I'll +call 'y sub t', let's try + +'e to the rx', where 'r' happens +to be a constant. + +You see, the whole idea is if I +differentiate 'e to the rx' + +with respect to 'x', I get 'e +to the rx' back again, only + +with a factor of 'r', namely the +derivative of my exponent + +in this case. + +See, 'r' is a constant. + +The derivative of 'rx' with +respect to 'x' is just 'r'. + +So notice that the first +derivative of 'y sub t' with + +respect to 'x' is 'r +'e to the rx''. + +The second derivative +of 'y sub t' with + +respect to 'x' is what? + +'r' is a constant. + +I differentiate 'e to the rx'. + +That brings down another factor +of 'r' and leaves me + +with 'e to the rx'. + +You see, the whole idea being, +notice that 'e to the rx' is a + +common factor of 'y sub t', 'y +sub 't prime'', 'y sub 't + +double prime''. + +If I now substitute these +results back into my original + +equation, look what I wind up +with. 'y double prime' becomes + +'r squared 'e to the rx''. + +Minus '5y prime', that's minus +'5r 'e to the rx'', plus '6y', + +'6e to the rx'. + +And that must equal zero. + +And here's the key point. + +'e to the rx' is now +a common factor. + +I factor that out. + +If the product of two numbers +is 0, one of the + +factors must be 0. + +But notice from our graph of the +exponential, the inverse + +logarithm, 'e to the x', 'e to +the rx' can never be negative + +and can never be 0, +in fact. 'e to the + +rx' is always positive. + +Therefore, if 'e to the rx' is +always positive, it must be + +the other factor which is 0. + +But 'r squared' minus '5r' plus +6 is not a second-order + +differential equation. + +It's a second-degree polynomial +equation. + +It's a familiar quadratic +equation, which I can solve + +quite easily. + +In other words, I find what? + +That 'r' must be either 2, +or 'r' must equal 3. + +In other words, my claim is that +either 'e to the 2x' or + +'e to the 3x' must +be a solution of + +this particular equation. + +Of course, we can do more with +that, which we will in a later + +part of calculus, not in +this package's work. + +But we're not going to study +differential equations in + +great detail here. + +But for our present purposes, +I think this illustrates how + +one can use the fact that it's +a rather powerful structural + +property when the derivative of +a function with respect to + +'x' is the function itself. + +By the way, as a quick check, +notice that if 'y' equals 'e + +to the 2x', 'y prime' is +twice 'e to the 2x'. + +'y double prime' is +'4 e to the 2x'. + +And therefore 'y double prime' +minus '5y prime' + +plus '6y' is what? + +It's '4e to the 2x' minus '10 e +to the 2x', '6 e to the 2x'. + +And that, in fact, is genuinely, +identically zero. + +In a similar way, checking out +'y' equals 'e to the 3x', we + +get 'y prime' is '3e to the 3x', +'y double prime' is '9e + +to the 3x'. + +Therefore, '9e to the 3x' minus +'15 e to the 3x' plus + +'6e to the 3x' is again, +identically 0. + +And again, you see what this +powerful technique is. + +In general, if 'a' and 'b' are +constants, the substitution 'y + +sub t' equals 'e to the rx'. + +And there'll be a problem in the +exercises on this to give + +you additional drill. + +But that substitution transforms +the second or the + +differential equation, 'y double +prime' plus 'ay prime' + +plus 'by' equals 0, into an +equivalent quadratic equation, + +'r squared' plus 'ar' +plus 'b' equals 0. + +And you see from this equation, +using the quadratic + +formula, we can find the values +of 'r' that satisfy + +this, and that gives +us a couple of + +solutions to the equation. + +Well, at any rate, I +deliberately want this lecture + +to stay short to make the +most important impact. + +And that is again what? + +That once we knew what the +natural log function was, and + +we defined the inverse natural +log function, everything that + +we wanted to know about the +inverse natural log followed + +from the properties +of the log itself. + +And this is basically the +lesson for today. + +We will continue the discussion +of exponential + +functions from a different +point of + +view in our next lecture. + +But until that next +lecture, goodbye. + +ANNOUNCER: Funding for the +publication of this video was + +provided by the Gabriella and +Paul Rosenbaum Foundation. + +Help OCW continue to provide +free and open access to MIT + +courses by making a donation +at ocw.mit.edu/donate. \ No newline at end of file diff --git a/rV5eSoBqrsY.txt b/rV5eSoBqrsY.txt new file mode 100644 index 0000000000000000000000000000000000000000..7dc19067a20c7923ceb8eb40245763c739e72dd9 --- /dev/null +++ b/rV5eSoBqrsY.txt @@ -0,0 +1,3777 @@ +We're quite lucky today to have Bob Sieck +talk to us about launch operations. + +Bob joined NASA early in his career after +a spell with the Air Force. + +This was in the early '60s. + +And he worked on prelaunch checkout and servicing +of Gemini and Apollo. + +Then went into the Shuttle Program. + +He worked on ground operations for the Approach +and Landing Tests. + +We will hear more about that testing when +Gordon Fullerton comes here at the beginning + +of December. + +And then he worked as Launch Director for +a lot of the early Shuttle missions, including + +my first flight. + +And then went to be the Shuttle Operations +Director at Kennedy Space Center. + +But then after the Challenger accident he +came back and worked on another, I don't know, + +40 or so launches. + +I think my last launch was in '96. + +You had already graduated, right? + +Yeah. + +But Bob was the Launch Director of the first +four of my flights. + +He is the head of the whole team of really +thousands of people who are responsible for + +getting the Shuttle ready to fly and for certifying +that, in fact, it is ready to fly. + +It is a very complicated, critical and from +the safety point of view absolutely one of + +the most important things we do, is to figure +out when this incredibly complex vehicle is + +really ready to go. + +Bob is going to talk to us both about some +of the technical aspects of the launch operations. + +But also I hope, from a systems engineering +point of view, we will have a chance towards + +the end to talk about some of the planning +that was going on while the Shuttle was being + +designed and some of the compromises which +had to be made, some of which we've already + +addressed, between the efficiency of turning +around and maintaining a vehicle like the + +Shuttle vis-à-vis the actually initial upfront +cost of it. + +With that as an introduction, Bob, I will +turn it over to you. + +Thanks, Jeff. + +And good morning. + +As Jeff indicated, I got into the business +of launching people and payloads into space + +a long time ago. + +I was privileged to be part of all of the +human space flight programs, so I did a lot + +of that. + +What I didn't do, I saw most of. + +And I have an opinion on all of it, so please +ask questions. + +If I don't have the answer, I am sure to have +an opinion. + +I am going to spend a little bit of time, +we talk about launch operations, but that's + +the final three to four days of a campaign +that begins three to four months before you + +actually start the countdown clocks and put +the astronauts in the vehicle and go fly. + +So I am going to spend some time on the background +of preparing the Shuttle, the ground systems, + +the flight systems prior to the launch count +process particularly to talk about the engineering + +involvement and the responsibilities in those +processes. + +But, in order to talk about launching, I have +to talk some about the operations of putting + +the final pieces together and doing the tests +and inspections prior to launch. + +And then I want to get into the real meat +of it which is the human factors, the role + +of the engineer, the role of the managers +in the process of testing, inspecting, checking + +the flight systems, the ground systems and +certifying that it is OK to put the crew in + +and go fly. + +And that's where we're going to spend most +of our time, but I've got to go through some + +background first. + +I don't know how many of you have been to +the Kennedy Space Center. + +Anybody been down there? + +OK, so you've seen it. + +It is a city where we've launched everything +since the beginning programs, Mercury, Gemini, + +Apollo. + +The most prominent fixture is this Vehicle +Assembly Building which was used for the Apollo + +Program to put together the 300 foot tall +Saturn-Apollo rocket. + +Shuttle is about half that size but we use +this building to do the assembly. + +And I will talk a little bit about that later. + +But it is a city. + +We have our own power systems. + +We have facilities to check out the orbiter +to process the solid rocket motors. + +We have administrative homes for the people. + +And, of course, we have the highly visible +launch pads that are out on the ocean. + +And we also have a runway. + +When the weather cooperates and we can bring +the shuttles back to Florida, we can take + +care of the landing and recovery there. + +The process. + +We'll talk a little bit about the process. + +When an orbiter returns from its previous +mission, it goes through essentially a disassembly, + +inspection and then build it back up and test +it to make sure that it is still within the + +certification base that the engineers set +up for it that you've already heard from previous + +to this lecture. + +You would like to think that if the Orbiter +flies and the rest of the element is a successful + +mission you can just do it like an airplane, +take down the down cargo, whatever, get it + +configured for the next payload that is going +to go up, clean the windshield, so to speak, + +and the crew cabin and go fly it again. + +But the rules don't allow you to do that. + +The rules that the other engineers who have +talked to you have set up are such that you + +have to assume that in some way, even though +during the mission everything seemed to work + +OK, that that hardware was compromised through +the process of reentering, landing, refurbishing + +those systems that have to be refurbished. + +Something may have been invalidated. + +So you have to test all that stuff that worked +just fine in the previous mission, plus all + +of the systems that were not used in the previous +mission, particularly the backup system, the + +things that you would have to rely on in the +event that the primary system doesn't cooperate + +during the next mission. + +And, because of the way the Orbiter was built +with its miles of wiring and thousands of + +components that are active components, you +have to disassemble a lot of that stuff in + +order to meet the requirements that the program +is levied on. + +After the Orbiter lands and you get it safe +and the crew is out and you take out the payload, + +we spend a minimum of two to three months, +roughly a quarter of a million labor hours + +of touch labor on the Orbiter to do this disassembly, +test, inspection, refurbishment process before + +we move it from the hanger, take it to that +Vehicle Assembly Building, integrate it with + +the tank and the solid rocket boosters and +take it on out to the launch pad to go fly + +again. + +And that's where the lion's share of the work +is. + +The work on the tank and the payloads and +the solid rocket boosters is all peripheral + +to the processing of the Orbiter. + +Yes, sir. + +[AUDIENCE QUESTION] Do you find a lot of failures +when you go through? + +We find very few. + +And you could do the tradeoff of, well, is +this effort worth it? + +But, on the other hand, the few that you find, +you're glad that you found them because if + +not you may not have discovered them until +you got out to the launch pad and serviced + +your hazardous systems. + +Or, worse yet, you find out when you get in +the mission. + +And then the impact of that could be not only +a safety impact but could be a higher consequence + +than spending the month to two months in an +orbiter processing facility doing that work. + +Yes? + +But is there a learning curve? + +I mean after each mission do you know which +system you have to look at specifically? + +We look at it and say this system is performing +just fine so we don't have to do this intense + +invasive inspection and test every flight. + +Maybe we can just do it once a calendar year +or every two to three missions, whatever the + +designer thinks is the criteria for checking +on the health of this system. + +And we've done that over the years. + +And after we've had a couple of years of missions +where everything is working just fine, we + +start relaxing these requirements. + +And then something like Challenger happens +or something like Columbia happens and the + +pendulum of conservatism swings the other +direction. + +And we do more tests and more inspections +to verify the hardware because people want + +to be able to say, and we want to be able +to say, well, we've done everything possible + +to make sure that that's a 100% functional, +operating, safe orbiter. + +And so getting this process down to where +it meets the original advertising brochure + +which was we're going to fly these things +every two to three weeks, you start in that + +direction. + +And then events occur either during the mission +or you have the really bad incidents like + +Challenger and Columbia. + +And the conservatism swings the other way +and you end up doing more work. + +And, in addition to that, engineers, because +we are what we are, I was one, we have all + +this hardware available, we like to modify +it. + +We change it. + +We upgrade it because there is new technology +available in computers or in composite materials. + +So, when the orbiter gets to this processing +facility, regardless of how well the mission + +flew, the designers, with their good intensions, +say we want this orbiter to last another five + +years or ten years so we want you to do this +upgrade to the avionics system or we want + +to change out all of the actuators that hold +the payload in the payload bay and this and + +that. + +So you modify. + +And that adds more time. + +It makes more complexity to the process which +invites more tests and inspections. + +You're constantly in a mode where unfortunately, +if the mission flies perfectly, by the time + +you plan your campaign through the processing +facility -- + +You plan your campaign with schedules to last +two months maybe, roughly a third of the work + +you do is work that you hadn't planned when +you initially brought that orbiter into the + +orbiter processing facility. + +It's nonstandard work. + +It is stuff that you uncover in the process +of doing your test or inspection or its new + +requirements or new changes that come from +the designers that have to be implemented. + +And, from an efficiency standpoint, if you're +in the manufacturing or production business, + +that is not efficient. + +If a third of your work that you laid out +for the next two months, at the end of that + +two month period, a third of it was stuff +that you had not planned on doing which means + +you don't have the parts ready, you don't +have the engineering, you don't have the instructions. + +Yes? + +Do you build in time to cover that now? + +Contingency time, yes. + +Let me go back to that. + +We set up our team and operations to run five +days a week, two shifts a day leaving the + +weekends free to catch up for this nonstandard +stuff. + +We essentially end up running a six day work +week if we're in a standard template of flying + +three missions a year, which we're not now +because we're still recovering from the Columbia + +accident. + +We end up working six days a week and roughly +every three or four days we will work a continuous + +around the clock 24 hour operation. + +We try to maintain that original schedule +but we only make it roughly 50% of the time + +due to this, again, nonstandard work, the +extra stuff that works its way in. + +And that's why we have a big team. + +Our team is made up of the United Space Alliance +as a contractor. + +They do the hands-on work. + +They have the technicians. + +They have the engineers that staff the consoles. + +And they are roughly a 6,000 population at +Kennedy Space Center. + +They take care of the orbiter, the tank, the +boosters. + +They are responsible for maintaining all of +our equipment that hooks into the shuttle + +that is required, the process of servicing +it. + +And they have ties to the contractors, the +original equipment manufacturers that built + +the hardware. + +Technically, they can gain access to all the +original manufacturing records for the parts + +that are in the shuttle. + +NASA's responsibility -- +NASA owns the requirements for the Shuttle. + +We delegated all the operational work to the +contractors, but it's a national resource. + +Taxpayers paid for it. + +The government has a responsibility. + +They cannot divest themselves from that. + +NASA owns the requirements for saying what +you test, what you inspect and what the specifications + +are for acceptable performance of that. + +That is controlled by NASA. + +The management of the contractor at Kennedy +is done by NASA engineers in an organization + +that has roughly 500 people out of the 2000 +population at Kennedy Space Center of civil + +service people. + +500 are directly associated with the Shuttle. + +The rest do payload work. + +The Space Station, of course, is a big work +item now at the Kennedy Space Center. + +And they are responsible for the requirements. + +If somebody wants to change the requirement, +a NASA person has to approve that change. + +And we do insight and everything the contractor +does. + +We have at each one of the milestones, when +we leave the processing facility, when we + +leave the Vehicle Assembly Building and when +we get ready to launch, there is a review + +conducted by NASA to review the work that +was done by the contractor during the preceding + +weeks or months. + +And NASA approves moving the vehicle onto +the next stage of its assembly prior to launch. + +And the launch director specifically is responsible +not only for those last few days of the campaign, + +so to speak, leading up to launch, but also +insuring the government contractor team has + +all the tools available to them to be successful. + +Is the work being scheduled in an orderly +fashion? + +Is the ever-tightening budget constraining +their ability to get their work done? + +Is there too much scheduled pressure to meet +a milestone? + +That is the launch director's job. + +The launch director doesn't just come in the +last three days of the campaign with a tie + +and a suit and orchestrate the countdown. + +They have a responsibility from the beginning +to the end of the campaign. + +Engineering. + +I have already addressed this, but the NASA +engineers manage the requirements, the changes + +to the requirements. + +They are the ones in addition to the contractor, +this is a check and balance, that look at + +all the data, the engineering results of the +tests and the inspections. + +And they approve that they met the requirements. + +Also, they participate in critical operations. + +A critical operation is a test on a specific +system. + +Servicing of the vehicle for launch count +or any of the non-standard work that comes + +up during the process. + +They audit what the contractor does. + +And, of course, because we're the customer +and they are the contractor, we have a lot + +of criteria to grade them on for their award +fee performance. + +The operations people manage the scheduling. + +As I indicated, we like to work five days +a week, two shifts a day. + +We really end up working six days a week and +sometimes around the clock. + +The scheduling activity is dynamic. + +And NASA approves all the scheduling. + +We have to approve all the overtime. + +We have the authority to say stop or go not +only in launch count but anywhere in the campaign + +of processing the hardware, as well as the +big picture schedule, you know, how many times + +a year you're going to fly and which orbiter +is assigned to which payload in those missions. + +That is still a NASA responsibility. + +Orbiter processing facility, like I mentioned +before, it is like a hanger for an airplane. + +A big part of the work effort used to be the +tile. + +I think you already had a presentation on +tile. + +There are 25,000 to 30,000 of these little +bricks glued to the vehicle. + +We classically damage about a hundred of them +on each mission due to ice and things coming + +off the tank that have to be replaced, but +we also pull another hundred or so off just + +to inspect the integrity of the glue that +is holding the tile to the structure of the + +vehicle. + +Because a lot of those little bricks have +been glued on there for 25 years and have + +flown 25 to 30 missions. + +Although we have offline test programs that +try to duplicate the environment that the + +tile sees either from a calendar standpoint +or the thermal cycles of the mission, you + +would like to go to the real hardware and +see what is happening. + +We do that invasive type of work of actually +destroying tile, pulling it off the vehicle + +just to make sure that the aging process is +not causing any degradation of the system. + +We pull the engines out and do the maintenance +on the engines offline because the aft fuselage + +of the orbiter is a terrible place to work. + +Any of the hardware we can get out of there +and do it on the bench, it is much better + +to do that than to try to do it in the vehicle +with people crawling all over wire bundles + +and structure and that sort of thing. + +They are concerned about the collateral damage +to do the other work in that compartment of + +the vehicle where the engines are. + +Of course, you've got to take the accommodations +from the previous mission out of the payload + +bay and put in the new stuff for the next +mission. + +I already mentioned modifications. + +Unfortunately, we change more stuff than we +probably should but in order to keep up with + +the aging of the vehicle and the new technology +that goes with the territory of flying a system + +that was designed over 30 years ago. + +And we prepared for the next milestone which +was the vehicle assembly building operations. + +This is where we put the big pieces together. + +The solid rocket boosters are stacked. + +There are four segments in each booster. + +That is a very critical process but only takes +less than a month to do. + +The external tank comes in essentially ready +to fly from Mississippi. + +Except, as you know now, because of the Columbia +accident, we are still looking at the ramifications + +of these lines and other fittings on the tank. + +The acreage foam on the tank, just to digress +a little bit, is sprayed on. + +And that stuff is tough. + +Early in the program we had problems with +some of that coming off, but we solved that + +years ago. + +What we haven't solved is where you have to +do a manual application of foam over a fitting + +that is there because that is where the crane +is attached to it or because there is a line + +there that has to be installed at the Kennedy +Space Center. + +You cannot do it back at the factory. + +Putting that thermal protection system foam +on there is a labor-intensive process. + +It is a critical technique process. + +And, obviously, there are still flaws in the +process that the engineers haven't sorted + +out yet. + +And that is why that stuff keeps coming off +the tank in those places. + +But the solid rocket motors are attached to +this mobile launch platform with four bolts + +the diameter of my wrist. + +The structure engineers really figured this +out good. + +There are four on each one of those that are +attached to the launch platform. + +The tank is attached to the boosters with +four attach points, and those are bolts, again, + +that are the diameter of my wrist. + +And then the orbiter is hung on the tank in +three places with the same sized bolts. + +You've got six million pounds of weight that +is attached to the mobile launch platform + +that is held up by these four bolts, well, +eight total on the solid rocket motors. + +And they work out the dynamics of when the +engines start because the vehicles sways like + +this because the center of gravity is not +right over where those eight bolts are attached. + +And that system works fine. + +It always amazed me that you could hang that +much weight on those few bolts that are only + +the diameter of this, but it works. + +The orbiter is brought over after its campaign, +it's hung on the tank and we test all those + +connections between the solid rocket booster, +the platform, the tank and the orbiter. + +And that only takes about a week to do that. + +And, if that looks good, we have a review +of all of that work. + +And if the review says we didn't leave anything +undone, that we shouldn't take out the launch + +pad then we go out to the launch pad. + +[AUDIENCE QUESTION] Sure. + +Say a little bit about this difference from +just bringing your car into have a 50,000 + +mile checkup, that is the clean room aspects, +the following of procedures, of having a checker. + +Sure. + +Well, a 50,000 mile checkup on a car is usually +an external inspection. + +You change the oil and the filter and you +check all the belts and the radiator hoses + +and you change all the fluids. + +Well, you do that with the orbiter also. + +But, in the case of the orbiter, you want +to know whether you are this far away from + +having to do a valve job or the rings in the +engine have now got so many thousand miles + +on them. + +We have the equivalent. + +You take the heads off the engine and you +give it a valve job. + +And you take the pistons out of the block +and you check for scoring in the block. + +You take the transmission out and you pull +the gears out and make sure that the synchronizers + +are still OK. + +And you go through the rear-end. + +And you take all the avionics out. + +Or, you take your carry-on test equipment +in and you hook it up to these connectors + +on the airflow meter and the computer in your +vehicle and you run all those diagnostics + +to make sure all that stuff, even though it +worked fine after you turned that ignition + +key off the last time, that all the redundancies +and all the capability is still within that + +hardware and all the margins are still there. + +And then you button it back up and you make +sure you button it back up properly, all of + +which is pre-established quite rigid flowcharts, +checklists. + +A checker checking the checker. + +Oh, yes, and you have inspectors where there +are critical things. + +If you're torquing the connecting rods onto +the crankshaft, it says that you've got to + +do those bolts at 50 something foot pounds. + +And the technician will do that. + +And there will be an inspector there verifying +that he set the torque wrench at 50 foot pounds + +and it really clicked there, and they stamp +the procedure that it was done that way. + +I wanted to just add to that, I mean, even +more emphasis. + +You don't do anything to the vehicle or to +the payload unless you have a written procedure. + +What is absolutely not allowed is oh, there +is a little problem, something didn't work + +the way it was supposed to in the test. + +Let's just fiddle around. + +Let's throw a few switches and see what happens. + +Well, I mean, that is normally the way you +work at things if you're in a laboratory or + +working on your car. + +But the thing is you need absolute traceability. + +Because if something later on turns up out +of spec or there is an anomaly during flight, + +you need to be able to recreate everything +that was done to the orbiter. + +That is why we keep such good records on parts. + +Well, you can tell you that story about the +tires that you just mentioned. + +People keep track of where all the parts of +the orbiter came from, the lot numbers. + +And so, if any problem turns up, you can actually +then trace on the orbiter and see if it affects + +there. + +All the work is done for approved work authorization +documents, every step, every touch labor item + +that is done on the vehicle. + +And if you deviate from that procedure, which +is approved by engineering, you have to get + +engineering approval to deviate from it. + +The assembly process, the standard work process +of putting the vehicle together after a mission, + +there is over two million verifiable work +items for the standard flow. + +And that doesn't include modifications or +the nonstandard work that comes up, the proverbial + +glitch that occurs when you're checking out +your computer system or when you pressurize + +this fluid system and the leak rate is higher +than the specification allows. + +Well, engineering comes in and says OK, here +is the trouble procedure. + +Here is what you're going to pursue, but you +don't do any of that until the engineers write + +the procedure and give it to the technicians +or the console operators that say OK, here + +is what you're going to do to try to find +out the source of this leak. + +As Jeff indicated, you don't just start throwing +switches and turning valves and say well, + +let's see if we can find out what's going +on here. + +It is all pre-approved. + +And the reason for that is when you have these +reviews that culminate into final review before + +you get ready to fly, you want to be able +to say that this vehicle is assembled per + +print, that the designer's requirements, the +people that you've already heard from that + +certified that this system will work just +fine in flight if it looks like this when + +we launch it, you're trying to prove that +this is what it looks like when you launch + +it and it is within the certification base +and it is per the engineering drawings that + +we were given and it met all these requirements. + +Otherwise, you are guessing that it is OK +to go fly the machine. + +And you cannot do that in this business. + +[AUDIENCE QUESTION] Yes. + +Does that seem to create any sort of tension +on the engineers feeling like their hands + +are tied to go out and do stuff? + +Well, no, because they are the ones that ultimately +say what goes in those two million steps. + +And if they want to add more tests or checks +or inspections it is within their purview + +to propose that. + +The program, there is a group of senior engineers +that are on these what we call control boards + +that approve the requirements that are implemented +at the Kennedy Space Center. + +And they can say yeah, that's a good idea +or, no, we don't want to change this, go back + +and give us some more rationale for what you +think is a good idea to do to this system. + +In that respect, it is probably somewhat frustrating +for the engineers because they cannot do anything + +different from last time unless they can justify +the rationale for it. + +But that's the way it ought to be. + +The launch pad. + +The facilities at the launch pad are pretty +simple. + +These are the same launch pads we flew from +in Apollo. + +We've got storage facilities for the liquid +hydrogen, liquid oxygen. + +We try to spend a minimum amount of time at +the launch pad because Florida is a nice place + +to be on spring break but it's a bad place +to have exotic hardware sitting outdoors with + +all that salt, humidity and all the other +elements that mother nature throws at you + +like lightening. + +And, I think you can see down here, we have +a good lightening protection system. + +There is a single mast with two wires that +go out about a half a mile from the launch + +pad. + +It makes a good Faraday shield. + +And over the years we've been whacked a lot +of times with lightening. + +In fact, it's a good attraction for lightening. + +And we have never gotten energy inside of +that Faraday shield to damage any hardware. + +However, when we get lightening down there, +we tell the workers to stand down and, of + +course, seek safe haven. + +But we have instrumented it. + +And it has taken some big hits, but we haven't +gotten anything major inside that would cause + +us a problem from electric. + +Yes? + +After you take the Shuttle out onto the launch +pad, is it very expensive to roll it back + +when you find a problem and then bring it +back out again? + +Yes, it is. + +And that's why we have these reviews before +we commit it to go to the launch pad to make + +sure that we're not taking any unknowns or +any work out to the launch pad that should + +rightfully be done either in the Vehicle Assembly +Building or further back in the Orbiter Processing + +Facility. + +It is a lengthy process because it takes about +a week to hook everything up at the pad and + +check it before you go into the process of +servicing the propellants and doing the hazardous + +work which has to all be undone if you roll +back to the Vehicle Assembly Building. + +You've got to make sure you're really ready +to go before you head on out there. + +Yes? + +Approximately how many times has that happened? + +Going back? + +Well, we probably have done it for technical +reasons maybe 20% of the time. + +For weather reasons like we're worried about +a hurricane or something like that the same, + +about 20% of the time. + +One out of every five times we've gone to +the launch pad, we've had to come back for + +either a weather problem or a technical problem +that either occurred at the launch pad or + +it's something that happened with a different +vehicle in the fleet that may still be in + +the Orbiter Processing Facility or a components +that is similar to one that is on the Shuttle + +that is at the pad that they were doing testing +in the laboratory or doing what we call fleet + +leader testing at one of the NASA facilities. + +And they said, you know, there is an inherent +flaw in this auxiliary power unit and we have + +to change the ones that are in the orbiter +because they were manufactured at the same + +time or they have the same component on them +and you cannot do that work out at the launch + +pad so you've got to roll it back. + +So the hardware at the pad may be just fine +from the standpoint that you followed your + +processes and they checked out great in the +previous part of the campaign. + +But an offline issue can cause you to say +no, we've got to roll back and go change out + +this hardware or fix it or further test it +before we can commit it to go fly. + +We have a big water tower out there also which +I will talk about later. + +That is our sound suppression system. + +But basically a month is the maximum time +you like to spend out there. + +We used to put a lot of payloads in the Orbiter +Processing Facility when we were flying laboratories + +and that sort of thing. + +Space Station hardware, we install all that +out at the launch pad now. + +And we test all the connections at the new +facility. + +And we have a simulated launch count with +the astronauts. + +And this is a tradition that goes back to +the Mercury program. + +They bring the astronauts down to the Cape. + +They go through a day, two days of training, +emergency egress, familiarization with the + +hardware, And then we have a simulated launch +count without the propellants and all the + +hazardous stuff just to, if nothing else, +remind the launch team that this is more than + +just a machine. + +We are going to fly people in this thing. + +And this occurs roughly two weeks before launch. + +And it is a good readiness test for the whole +team. + +It's serious. + +We're a couple weeks before flight. + +The crew is in town. + +This vehicle is going to look the best it +ever has. + +And we do a simulated launch countdown to +within a couple seconds of liftoff. + +And then we do a simulated abort with the +safeing of the vehicle and the crew gets out. + +And I will just add something. + +That is always something the crew looked forward +to, first of all, because you actually get + +to get in the vehicle which, despite the fact +that we have pretty good simulators in Houston, + +there is nothing like actually crawling inside +the shuttle that you're going to fly in. + +And there is a lot of safety training that +you do down at the Cape which is really kind + +of fun. + +You don't have any pictures of the launch +escape, the pad slide wire basket? + +No, I don't think so. + +There is a requirement that you need to be +able to get off the pad quickly if there is + +a launch emergency. + +And, of course, on the real launch day, unlike +the simulated countdown where the pad is crawling + +with people, on launch day there are very +few people, even when you're getting into + +the vehicle because it is fueled. + +And then everybody else leaves. + +So they have this big slide wire where if +you have to get out of the orbiter in a hurray + +you go out and you jump in the bag, hit a +little guillotine and it cuts you loose and + +you slide all the way down. + +Actually, in the early days, the astronauts +kept saying we need to try this out. + +And they said no, you cannot do it because +it hasn't been man rated. + +We said wait a minute. + +Well, it's rated for emergency use only so +you cannot try it out. + +And then after Challenger they insisted that +somebody actually ride down in it. + +Not every crew. + +Just one person tried it out. + +But the other thing that you do, once you +get down to the bottom there is an underground + +bunker that you run into. + +And either you stay there and wait for help +or they have these armored personnel carriers + +sitting around there with little tanks which +you get in. + +And you've got to be able to drive your tank. + +They have a breakout section of the fence +so you drive the tank through the fence out + +to a helicopter pickup point. + +So we all have to go out and learn how to +drive the tank. + +And we drive over the sand dunes and everything. + +And then also they have a big pool which they +light on fire. + +And they give you a big fireman's hose and +they show you how to make your way through + +a fire by squirting a water path in front +of you. + +All the little things you dream of as a kid, +to be a fireman, drive a tank. + +So it's good fun. + +But it is part of the extensive safety procedures +that they have. + +And all these things periodically they have +to exercise. + +They do go through, every once in a while, +a disaster drill down at the Cape where they + +simulate an emergency where they have to pick +up the crew either outside the launch pad + +or either out in the ocean. + +And you've got to keep people at full operational +readiness. + +That's one of the aspects of training. + +We train for the anomalies, the nonstandard +things. + +The standard work, they do so much of that +anyway you don't have to train for that. + +You don't have to train to put a payload in +the payload bay. + +You don't have to train to power up your system +and run your system checkout because that + +is a repetitive thing. + +But the nonstandard stuff, when things go +wrong, that's where the emphasis of the training + +is. + +And, like Jeff said, it's a lot of fun. + +It's fun for the launch team, too. + +We have a control center at the Cape, and +it is called the Launch Control Center. + +You would think this is where you launch it +from. + +Well, you do that. + +But all of the other work that is done in +the preceding three months is controlled from + +the Launch Control Center by test conductors +and engineers who wrote the procedures and + +the software that implement all the requirements. + +And they control the activity on the orbiter +or the tank or the boosters when it is still + +back in the offline facilities or the Vehicle +Assembly Building or out to the launch pad. + +They do it from the Launch Control Center. + +We automate what we can from there. + +But for the manual activity -- And a lot of +it is manual because regrettably you cannot + +do all this refurbishment on the shuttle with +automated systems. + +It wasn't built that way. + +It is all managed from out Launch Control +Center with old computers but with a great + +team + +of people. + +The software we use in the computers, I am +not going to go into a lot of detail because + +it is really old stuff, but it works. + +It is like the software program that the FAA +uses to track airplanes. + +It is hacker-proof. + +There are no external interfaces outside of +the Launch Control Center firewall. + +It works just fine. + +And that is where we do the management of +our day-to-day operations from our Launch + +Control Room. + +And we call it the LPS Launch Processing System +software. + +We've tried to change it a couple of times +over the years. + +Buy new hardware. + +We have supplemented it with laptops so that +we can do more human engineering displays, + +but the computers are the same ones that we +bought back in the late '70s. + +But then so are the computers that are on +the orbiter that fly the machine. + +So it works. + +This is a bit repetitive, but I want to go +through it again to make sure to emphasize + +what the role of the engineering is. + +The designers that you've heard from, they +certified their design. + +And they did extensive testing, just like +Detroit does on a car on the door latch. + +And they've tested that door latch and said, +well, this thing out to be good for 250,000 + +miles or 20 years or so many gazillion opening +and closings of the door before it wears out + +and you've got to replace it. + +Well, they did all that. + +And to make sure that that hardware is still +within the certification base, they developed + +requirements, sent them down to the Cape. + +We put them in the procedures, either manual +procedures or software to implement those + +requirements. + +And the team, United Space Alliance the contractor +and the NASA engineers will certify at each + +of the milestone reviews and the process of +moving the hardware out to the pad they've + +met those requirements. + +And they did that either by participating +in the activity or by reviewing the test data. + +And that allows us to sign a certificate of +flight readiness a few days before launch + +that all the requirements have been met. + +When we get into launch count, we take in +a subset of those requirements that when everything + +is powered up and ready to go fly all of these +systems that are active ought to look like + +this. + +The voltages should be between this upper +limit and this lower limit. + +The pressure should be between here and here. + +These indicators should show that they are +open and these indicators should say that + +this latch is closed or the valve is closed +or whatever. + +And we put that in what is called launch commit +criteria. + +And that is the acceptable limit for the performance +of that hardware when you're at that point + +which is nine minutes before launch when everybody +commits that they are ready to go fly. + +And all those requirements, again, are implemented +by procedures in software. + +And the three days of launch count have roughly, +these are numbers, but about 500 requirements. + +There are thousands of measurements associated +with those requirements. + +And most of the looking at those measurements +is done by computers, obviously. + +But you have the engineer involved because +if it is not within limits you turn to the + +engineer for what is wrong. + +Is there any chance to go fix this or do we +have to change hardware? + +Do we have to do trouble shooting? + +So it's not a hands-off operation, obviously. + +The +structure of the launch team, the launch director + +is shown in the middle, but that doesn't mean +he or she is the only one with a go or a no-go + +button. + +The people the implement the requirements, +there are roughly 150 of them in our Control + +Center, and they are the ones that provide +the go, no-go for all the subsystems both + +flight and ground that everything is operating +within the limits. + +They report that to a team of test conductors, +NASA and contractor, and that's reported to + +the launch director. + +We are not along, obviously. + +We have an engineering support area, which +are all the hidden senior engineers that you + +don't see on television. + +And there is a room full of about 150 to 200 +of those. + +And they are looking at the performance of +these systems as they are activated in launch + +count. + +And they've got all the trend data, the previous +history of it. + +And they're looking at things like, well, +all right, everything is in limits, but is + +it within family? + +The last time the system performed the voltage +with this or the pressure was this. + +Well, it's still in limits. + +But it's not the same as it was before so +we go look at it. + +Well, that's for this group of engineers over +here. + +These guys and gals are running through their +procedures. + +And, if everything was within limits, we just +turn to the next page and go onto the next + +one. + +And they also have the emergency procedures. + +If something bad happens these are the people +that will implement the emergency procedures. + +This offline support, they're out there. + +They're the senior people, they've been there +before, they've been out there who knows how + +many years and they're asking questions like +that didn't look right or we missed that step, + +go back and check it again. + +That's what they are for. + +The mission management team over here, these +are the people that do the certificate of + +flight readiness. + +These are the folks that stand up in the readiness +reviews and say I gave the Cape folks a good + +set of requirements. + +There is nothing that happened with the hardware +that they're responsible for. + +And all those offline facilities are on previous +missions. + +That shouldn't have any cloud over this mission. + +They are responsible for certifying that. + +And they do that through a structure of the +mission management team. + +You've got, of course, the flight director +with flight rules and the flight team that + +they look at during the launch count process. + +And you will hear more about that from Wayne +Hale. + +And they, obviously, have a go, no-go input +to the launch director in the decision process + +also. + +We have an integration activity. + +They system engineers are each responsible +for, you know, they have boundary conditions + +on what they are responsible for. + +It is these pieces of hardware. + +It is this wiring. + +It is these actuators or latches or whatever. + +But a lot of that stuff fits together. + +Integration is a technical term for making +sure that this person talks to this person + +and that they are hooked in with this one. + +That activity is done by a console in the +Control Room, again, with senior engineers + +who actually manage all the automated software +that runs the last couple hours of launch + +count that really launches the vehicle. + +And they are tied in with that. + +You also have the more subjective stuff. + +We launch on a public range. + +Public safety is obviously an issue, so the +range has to make sure that it is safe to + +fly from a public standpoint, there are no +boats in the launch danger area, no airplanes + +and that the weather meets the criteria of +being able to track the vehicle should it + +go off course. + +And, of course, the payload has to certify, +particularly if there is an active payload, + +that all of their launch commit criteria is +met. + +And last, but certainly not least, you have +safety oversight of all of that activity. + +And what I don't show on there, of course, +is the flight crew, but they are obviously + +in communication with all of these people. + +So that is the network. + +But everybody out here has no-go authority. + +Anybody can come on the Net or press their +switch and say I've got a problem, we're not + +going anywhere. + +And it is the launch director and the launch +team's responsibility to make sure that problem + +is addressed, hold at the convenient, graceful +to stop all the activity hold point until + +the issue is resolved. + +The real job, and I'll get into this later, +of the launch director is to say no when everybody + +else wants to go because, as you get further +into the launch count, the "launch fever" + +process sets in. + +It is a natural thing, it seems to be. + +People want to go. + +I want to ask you about that a little bit, +I know we'll get into it later on, but flight + +rules and the launch decision, there are flight +rules that say you must scrub if these conditions + +are not met. + +Right. + +And, yet, there is a tendency to allow judgment +to come in. + +Let's take an example of a limit on crosswind +at you landing to the return to launch site. + +You see it go above limits, but the rules +strictly says no, you cannot go. + +Talk about that a little bit. + +That is what we use the mission management +team for. + +And you bring up the weather example. + +Most of this stuff is pretty straightforward. + +It is either the voltage pressure temperature +is in limits or out of limits. + +A person can question that and say I don't +like the trend, and you've got to stop and + +clear the air if they say I want more discussion +on this, I want more data review and that + +sort of thing. + +If it is a discussion like that involves activity +outside of the Control Room beyond the purview + +of the console operators that are running +through the procedure, we rely on the mission + +management team to manage that activity so +the console operators can concentrate on their + +launch commit criteria and their procedures +and their software. + +Something like crosswind limits, if there +is a debate with the flight director and the + +weather people, we hold the clock and say +mission management team, that is yours. + +You manage it, and whatever you have to do +to resolve the decision, we'll scrub if need-be, + +we'll hold if need-be, or if the community +can get comfortable that these crosswinds + +that are peaking occasionally out of spec, +that it's OK to go fly anyway, then we will + +wait to hear from the flight director that +that's OK. + +We don't insulate the Control Room from that, +but we don't want to burden the control center + +with work and what is an offline issue. + +And it is up to the mission management team +to disposition that. + +And you bring up weather because weather is +one of the few things that there is really + +a lot of judgment still involved. + +Is the weather good enough to go fly? + +And it is probably the only thing that is +in that category because everybody has an + +opinion on the weather. + +And Florida weather is dynamic. + +And usually, unless it is wintertime, there +are clouds. + +And there is always a tendency, if you've +held for weather or the weather is marginal, + +to hold longer to see if the weather gets +better. + +And the real issue for the launch director +is to try to convince people, if the weather + +is good enough, that this is good enough. + +And, yeah, you could wait longer for it to +get better but it's good enough. + +We're running out of window time. + +All the time we sit here on the ground with +all these systems humming along, the probability + +of some glitch or something coming up to scrub +you is increased. + +And just as a personal note, when I was I +the Air Force, I was a weather forecaster + +for Missile Operations. + +And I felt that that was a waste of an engineer's +time because I was a graduate engineer with + +my diploma sticking out of my pocket. + +I wanted to go launch missiles and rockets, +and the Air Force said Lieutenant Sieck is + +going to be a weather forecaster supporting +Missile Operations. + +I endured that for a couple of years and put +all of that experience in my hip pocket. + +And I didn't need it until I got into this +launch director job. + +And I spent many hours talking to the weather +people who provide the forecast for the launch + +going over all of the data and the technical +aspects of the weather situation to see if + +there it was prudent to sit here any longer +and wait for the weather to improve or whether + +it was better to scrub, get these guys out +of their uncomfortable suits and send them + +back to crew quarters and recycle for the +next day. + +And they won't necessarily scrub, but you +have to disposition their concern. + +And you will hold until their concern is taken +care of. + +Yes? + +This is unrelated, but you know how the Russians, +in going out to the launch pad, use a rail + +track and they have the rocket flat? + +Can you do that with the shuttle? + +Instead of stacking it like this and then +rolling it out, would it be better, easier? + +Well, the problem with that are the solid +rocket boosters. + +They weight approximately, when assembled, +a little less than three million pounds a + +piece. + +And the joints that caused the Challenger +accident are critical. + +And I don't know if they went through the +technical aspects of the design, but these + +things are 14 feet in diameter. + +Each segment weighs 300,000 pounds and they +have these two cleavaces that come together + +with O rings in there. + +And what caused the Challenger accident was +there was rotation in these joints to the + +point where the O rings, because of cold weather, +weren't making a good seal and caused a gas + +path. + +And 1200 degree temperature. + +Exhaust plume just cut through the metal once +it found a path. + +So you want to maintain the integrity of these +joints. + +If you stacked them horizontally, and that +could be done, and then you lift this thing + +vertically, the joints aren't certified to +maintain their integrity doing that. + +Plus, you'd need some kind of huge crane to +pull this 3 million pounds from horizontal + +to vertical. + +I think it's something that could have been +done, had it been built into the design at + +the beginning. + +And the Russians have a tradition of doing +this. + +And so that is the way they design their rockets. + +For whatever reason, we never started that +way. + +From the very beginning, our rockets got stacked +vertically. + +And that's the way all of the American rockets +have been designed. + +Yes? + +[AUDIENCE QUESTION] The launch director, whether +it is flight worthy, actually, that mission + +management team is responsible for the flight +worthiness because they encompass not only + +watching what you did in launch count, but +the certification of all this hardware before + +it even got to the launch pad. + +And, ultimately, the launch director is responsible +for conducting an orderly launch and making + +sure that this mission management team doesn't +have any issues, that that engineering team + +doesn't have any issues, that the console +operators have really completed their procedures. + +That is their responsibility. + +And, if there is any fuzz on that, so to speak, +even though console operators say they're + +go, and the mission management team says they're +go and flight says they're go, if there is + +any concern about that, it's the launch director's +job to say no, we're not going to go fly today. + +We are going to give you another day or two +days to do more homework, look at more data, + +have more discussions. + +We're going to scrub today, even though everybody +may say we're go. + +And that has happened before. + +And I always wondered, after not too many +times, when I've said no, when everybody wants + +to go, whether I'll get the phone call saying +well, I'm glad you made it safe today, Sieck, + +but you don't have this job tomorrow. + +Well, I never got that call. + +Never did. + +The process, not to bore you with it, but +since it is an operation, normally we try + +to launch in the middle of a week, Wednesday +or Thursday. + +We usually take the weekend off before that +to clean up everything and give the launch + +team a rest, so we power up everything. + +And that's the way we start the process. + +And that's a couple of shifts worth of work +to bring up the ground systems, the flight + +systems, make sure that all the avionics hardware +really comes to life. + +And we put in a no work hold at the end of +that to take care of any problems. + +If that all goes well then we get into the +more critical activity that has time constraints + +associated with it. + +We load the fuel cell. + +That is the power plants and the orbiter reactants, +liquid hydrogen and liquid oxygen, because + +they have limited life. + +Even if you don't have the fuel cells activated +that stuff boils off and you lose it and that + +could count against your mission capability. + +And that is a hazardous operation also. + +And then we put in another no work hold at +the end of that. + +And then we have a period of time where we +bring up the final systems, put in the time + +critical storage, particularly when we're +flying laboratories and you put in plants + +or critters or whatever it may be either in +the crew module or the payload bay. + +And the last 12 hours down here is when you +really have got to make sure this is a real + +decision point right here. + +Are we going to load the external tank, put +a cycle on the tank? + +And we know that putting liquid hydrogen and +liquid oxygen, and there is roughly half a + +million gallons in a tank, puts stresses into +the hardware. + +You really don't want to do that unless you're +pretty sure you're going to launch that day + +or that night. + +We have a meeting before that to make sure +the weather looks pretty good and that the + +mission management team is not working any +offline issues. + +And that has happened before. + +A war story for you. + +In the early '80s, in one of our missions, +we assembled the mission management team to + +decide whether or not we ought to go load +the external tank and go fly. + +Everything looked pretty good. + +And the orbiter project manager said well, +I need to make you aware of this. + +I just got a telegram from the manufacturers +of the tires. + +And the manufacturer said they were inspecting +a lot, a lot of the tires of which we have + +two of them from the same lot on the Orbiter, +and they found some blems on these tires. + +And they don't know whether it's a manufacturing +flaw or an aging defect. + +And we don't know whether it affects the integrity +of the tires. + +But since we knew you were launching tomorrow, +we thought we would share this with you. + +Warm regards, BF Goodrich, I think it was +at the time. + +Well, the mission management team threw on +that on the table and said hey, we've got + +to go work this. + +These people, we don't know, they haven't +said they're not certifying the tires. + +They just said they've got a problem. + +Well, that's fine. + +The mission management team, go work that +and let's talk about whether or not it's prudent, + +under these circumstances, to go load the +tank with some probability that we get all + +the way down to T minus nine minutes and you +folks are going to say hey, we need to look + +at more test data on these tires or have more +discussions with BF Goodrich on whether or + +not we go fly today. + +Well, you don't want to load the tank and +go through all that if that's what you think + +the situation is going to be eight hours away +from that. + +And you've put a cycle on the tank, you've +used up a lot of cryos that you cannot save + +because of the heat leak. + +Plus, your launch team has put a cycle on, +depending on the time of day, they've been + +up all day, all night or whatever. + +Those are the kinds of issues that you need +to make sure get worked. + +And the mission management team has to handle +that, but the launch director has to decide + +just go work that for another day or two. + +We're not going to load the tank. + +Or, what's the promise of this coming to fruition, +the possibility so that it makes sense to + +go try to fly? + +What did you do with the tires? + +In that case, we went ahead and tanked. + +The subsystem manager for that, which you +may have already heard from, went back to + +a lot of the test data that they had run on +the tires, that they had been fairly recent. + +Langley, I think, was involved in it. + +And they said we don't have to worry about +those blems being a problem for the tires + +that are on the Orbiter which, by the way, +you don't have any access to at the launch + +pad. + +If we were going to change the tires, you +would have to roll back to the Orbiter Processing + +Facility. + +And that would be a couple of month's worth +of impact to that flight. + +We ended up not doing anything with the tires, +but it had the mission management team really + +busy for about eight hours. + +And this process takes about three days. + +And we have refined those procedures, as you +might expect over the years, to make this + +as an efficient and repetitive a process as +we can. + +In addition to minimizing the hazards to the +people and the equipment. + +Before we got to terminal count, usually we +take like a two minute break. + +This is a good time to do that. + +Terminal count phase. + +After the tank is loaded, half a million gallons +of liquid hydrogen, liquid oxygen, and there + +are no leaks, and we have leak detectors all +over the vehicle, and we've scrubbed a lot + +of launches because of leaks, we give the +crew a go to come on out. + +And a crew of seven or eight people, it takes +an hour and a half to get them all in and + +get them connected, check their communications +and that sort of thing. + +Roughly three hours before launch we bring +them out, we get them all connected, we close + +the hatch and we verify the integrity of the +crew module. + +And clockwise we're down to T minus 20 minutes, +but if it's a rendezvous window, and most + +of them are now. + +The launch window is only five to ten minutes +long so we have to be in phase with the same + +plane that the Space Station is in and we've +got to get in phase with being able to catch + +the Space Station or have it catch us. + +The launch window, we don't have enough energy +in the Shuttle to steer to any orbit we'd + +like to. + +The launch window is only about ten minutes +long, so we put in a long hold at T minus + +nine minutes for those kinds of missions. + +It is the equivalent of the two minute timeout +in a professional football game. + +Everybody has a chance to review their information, +discuss their strategies, if it's a long launch + +window, if it was just a lab mission then +we only wait for ten minutes at this T minus + +nine mark. + +But, if it's a short window, we set up the +clock such that we hold there for almost an + +hour. + +And then, as you saw on that previous chart, +we do a poll of all those people and make + +sure that they are all still go and they're +not working any problems or issues. + +And then we start this automated software +program that looks at, in addition to the + +systems engineers and their consoles looking +at all their information, we have an automated + +program called the Ground Launch Sequencer +that looks at all the measurements, all the + +parameters to make sure that they are within +limits. + +And it issues all the commands to the vehicle +and the ground support equipment. + +And we did that so we could manage the repeatability +of that process. + +And you had to take the human factor button +pressing out of the process as much as possible. + +And there is not a lot of work that goes on +in there. + +And there is very little manual work. + +You get five minutes. + +The orbiter access arm, their ability o get +out of the vehicle in a big hurry is retracted. + +It takes two to three minutes to pull that +back, but we can get it back up to the vehicle + +in less than 30 seconds which is about the +amount of time it takes them to unstrap and + +get out of there anyway if there's a fire +or something bad like that, that they have + +to do an emergency egress. + +They start the propulsion units on the Orbiter +that pressurize the hydraulic system. + +Just like on an airplane, there is an automated +test of all the aero surfaces like they do + +on the end of a runway. + +But this is done by the computer and it wiggles +the elevons and the rudder and the main engines + +to make sure all of that works. + +And we also start the conditioning of the +propellant at the engine interface. + +And they already had the discussion about +the main engines. + +You have to make sure that the quality of +the fluid in the external tank and the quality + +of it that's right there at the injector of +the engine is within the temperature and density + +parameters that the engine was certified at. + +Because we have to drain the propellant out +of the fill lines. + +And, once we've started doing that, that propellant +starts heating up right there on those valves + +that are going to go into the injector and +start the main engines on the Orbiter. + +That limits our ability to stop and hold after +that. + +We are good for four to five minutes after +that starts. + +And that process starts at T minus five minutes. + +After that point in time, we are either going +to launch or scrub in the next ten minutes. + +And then we pressurize the oxygen tank and +we pressurize the hydrogen tank, but anywhere + +in this period of time we can stop. + +If an engineer or the automated sequencer +says something is out of limits, we will stop + +at those milestones and disposition that problem +if we can. + +But, per our rules, we won't waive any requirements +at that point. + +Even though an engineer may have a perfectly +good explanation as to why this temperature, + +pressure or whatever, our limit is not being +met, if the launch commit criteria, the launch + +rules says no, it has to be like this, then +we're not going to go launch that day. + +We won't. + +After 31 seconds, the solid rocket boosters +come to life. + +The propellant doesn't ignite, but their hydraulic +system is powered up. + +Their avionics systems are powered up. + +Their engine nozzles are checked again in +an automatic sequence. + +And at 10 seconds, if everything looks good +and all these measurements that our Ground + +Launch Sequencer has been looking at, we send +up the computer data bus a go to the onboard + +computers that said all of our stuff has been +satisfied. + +Now, we're still looking at a few things. + +We're looking at those bolts that are holding +the solid rocket motors to the launch pad. + +And the ability to blow the nuts that are +holding them, should that system fail, we + +would send the cutoff to the onboard computers. + +Regardless of where the engines were in their +startup sequence, the three main engines, + +everything will stop. + +And hopefully it will gracefully come to a +stop and we will safe all the systems and + +go from there. + +But that is the final handshake that is preplanned +between flight and ground is that ten seconds + +when we send a command up to the computer +saying we are all go. + +We can still shut you off, and we can shut +you off manually, too. + +If a console operator sees something happening +that they think could compromise the safety + +of the launch, they can call for a cutoff. + +And we have a switch that says cutoff. + +It sends a command to the onboard computers, +and it will stop everything within 10 to 20 + +milliseconds. + +But you don't like to put humans in a position +to have to make that call. + +And that's why all of the critical stuff is +done by the computers. + +And I mentioned the Ground Launch Sequencer. + +That's a console and operators in the back +of the Control Room. + +And they are the ones, by the way, that determine +nobody presses a button for launch. + +A woman in the back of the Control Room types +the liftoff time into the computer when the + +launch director tells her, hey, look, it looks +like we're going to come out of our T minus + +nine minute hold at this point in time. + +So here is the liftoff time. + +Put that in the computer. + +And after that it's a hands-off operation. + +Can I ask, are these commands being physically +sent, I mean they're hard line cable? + +It's what we call a launch data vest. + +It's a cable that is connected from the computers +in the Control Room through the liftoff umbilical + +into the Orbiter computers. + +It's a data train. + +And when is that connection broken? + +At liftoff. + +The onboard computers will check the health +of the main engines, and if the three main + +engines are within all of their operating +parameters, the turbines and the pumps and + +the temperatures then it sends a command to +those eight bolts that hold the solid rocket + +boosters to the mobile launch platform and +the bolts that hold the external tank vent + +arm to the tank. + +And the two Orbiter umbilicals that says fire +the nuts, we're going to go. + +And that is orchestrated by the onboard computers. + +And when that happens you're flying, you're +going. + +The command to ignite the igniters on the +solid rocket motors is sent at that time also + +by the onboard computers within a couple of +milliseconds. + +So all that happens at once. + +And it's an onboard automated thing. + +I talked about the human factor that repeatability +is important. + +And I mentioned I gave the engineers, you +know, I always threw rocks at them because + +they always want to change things. + +It is the launch director's responsibility +to manage. + +They're the owner, so to speak, of the launch +count procedures, the 5,000 pages of documentation + +and the 500 or so software programs that are +executed in the launch count process. + +And we discouraged changes to that for obvious +reasons. + +Unless there is a modification to the flight +hardware or the ground hardware or we found + +something in our previous launch attempt that +said we need to fix this or there's an opportunity + +to increase the margins, we don't change it. + +We try to maintain the procedure and the hardware +the way it always has been. + +And it essentially is. + +We do training, obviously, but we train for +the nonstandard work. + +Just like in the flight team, we have a simulation +supervisor that throws diabolical failures + +out there and we have computer programs and +into the control center we bring the launch + +team, power up the consoles. + +And their displays look like the shuttle is +at the pad and it is getting ready to launch + +and we throw failures at them to test their +reaction and to find bugs in our safing procedures. + +And we've done that over the years. + +I think the next generation of vehicles will +probably have more automation. + +And that will probably be a better thing but +you will never take the console operator out + +of the Control Center either, the Launch Control +Center or the Flight Control Center. + +You need the person there to disposition the +problems, but predictability is what we're + +always after. + +And stable procedures, be they flight or ground, +give predictable results. + +And that is why we automate. + +And we control change, too. + +Responsibility. + +I talked about the engineers. + +I didn't mention, I don't think, technicians +and inspectors. + +But when a technician stamps a procedure that +I torque that bolt and the inspector stamps + +that same procedure and said I saw him torque +that bolt, that is their warranty that that + +event really happened. + +And that paper trail and that warranty is +very important. + +When an engineer signs a procedure that tested +the Flight Control System that said I reviewed + +all the data, didn't see any glitches, everything +met specifications, that signature is his + +or her warranty that the procedure ran correctly +and that they understood the requirements + +that were implemented by that procedure. + +And the requirements were met. + +And that is important. + +Our whole concept of launch readiness is based +on people being responsible for their system, + +be it the designer that signs it that says +there is nothing going on offline, there are + +no faxes out there that say there is a cloud +over the tires. + +Or, my last test of the main engines at Stennis, +there was nothing there that says these three + +engines that are on this orbiter shouldn't +work just fine. + +And they do that in a flight readiness process. + +That is their warranty and responsibility. + +And we hammer this home. + +And it probably comes from, I had this quote +in my office for years and I am going to bore + +you with it, and maybe some of you can guess +where this came from. + +Responsibility is a unique concept. + +It can only reside in here in a single individual. + +You may share it with others, but your portion +is not diminished. + +You may delegate it but it is still with you. + +You may disclaim it but you cannot divest +yourself of it. + +Even if you do not recognize it or admit its +presence, you cannot escape it. + +If responsibility is rightfully yours, no +evasion or ignorance or passing the blame + +can shift the burden to someone else. + +And this is what we push home. + +And, by the way, this quote was Admiral Rickover +who was testifying before Congress after the + +first nuclear submarine accident. + +And he was saying I am responsible. + +It is my program, it is my submarine, I am +responsible. + +Even though somebody else was commanding it, +it doesn't matter, I am responsible. + +And we impress that on the managers, the engineers, +the technicians, the inspectors, you know, + +you're important. + +And the work you do is important. + +And when you sign or stamp that procedure +or give a go on the Net that is your warranty + +that everything is working and you understand +the requirements. + +Very important in the business that we're +in. + +Decision making. + +On the chart. + +This structure has been in place since the +Mercury program. + +There is nothing new here. + +And the only issue comes in when there is +a gray area. + +Who makes the call and how much judgment is +involved in the call? + +And I gave you the example of weather. + +Everybody has an opinion on it. + +It can be judgmental. + +Well, the weather decision is if it is launch +weather related it is the launch director's + +responsibility to determine if it's good enough. + +If the flight director has an issue with the +return to launch site winds, that ultimately + +is his or her decision. + +The people may get involved in it and they +may have offline discussions with the flight + +director, but it is still ultimately his decision. + +And that is the way it has to be because they +are responsible. + +This mission management team is not responsible +for the go, no-go decision on weather on launch + +day. + +It's the flight director for the flight stuff. + +It is the launch director for the launch-related +stuff. + +And it is set up that way so there is no fuzz +on it. + +Other people can have an opinion, other people +can have input, but unless this person up + +here says launch director we're no go, it +is the launch director's decision in that + +case. + +Communication. + +Real important. + +And I will give you an example of that. + +Apollo 13. + +Most of you probably don't remember Apollo +13, but Apollo 13 was like Challenger and + +the Columbia except we didn't lose the flight +crew. + +But it was just as disastrous an event. + +And by all rights the crew shouldn't have +made it safety back to earth, but thanks to + +the heroics of the flight crew and the flight +team and the timing of when that event occurred + +they were able to get back home. + +But that was all caused by activity that was +done on the ground well before the launch. + +And, specifically since I was involved in +that, I remember this like it was yesterday. + +Of course, part of that is an old age thing. + +Stuff that happened 40 years ago comes in +loud and clear. + +Stuff that happened four days ago, I have +a hard time remembering. + +But we had a tank in the spacecraft that we +ran our simulated launch count. + +And back then we put propellants in the vehicle, +all the hazardous stuff and detanks. + +And we couldn't detank the liquid oxygen out +of this tank. + +They had the fuel cells on the spacecraft. + +And just a little more history. + +The tank had been dropped when it was installed +back in California, but engineers and managers + +did some tests and some rationale on saying +well, it's still OK to install it. + +We got it down the Cape. + +We put the liquid oxygen in it and all the +rest of the system. + +We couldn't get it out of this tank. + +And after reviewing it they found, well, the +stand pipe in there that is used to drain + +it on the ground was probably bent or damaged +and that's why we cannot get it out. + +So the managers and engineers got together +for a few days and said turn the heaters on + +in the tank and vent the liquid oxygen off. + +Heat it up and it will boil off as oxygen +gas through another loop that takes it through + +the fuel cells and out vent on the vehicle. + +Use the heaters to go do that. + +So they developed the procedure and we went +on station at night a week after we had the + +anomaly and turned everything on and turned +on the heaters. + +And it is fine. + +You can see the liquid is turning to gas and +it is coming out. + +And the console operator in our Control Room +said hey, Sieck, I cannot monitor the temperature + +in this tank anymore. + +Well, why is that? + +Well, the range on the temperature is from +ambient down to minus 300 degrees because + +it's measured in liquid oxygen. + +And it is upper limits. + +It started heating up, and now I cannot tell +you whether it is 50 degrees or 350 degrees. + +I said OK, stop. + +So we stopped the test and got all these managers +involved, including the people that built + +the tank and say hey, we've lost visibility. + +We're putting energy into this tank that has +liquid oxygen in it. + +We cannot monitor the temperature anymore. + +The pressure seems to be fine. + +They said don't worry about it. + +There is a thermostat in there that is heat +sensitive, and it will open up the power to + +the heaters if it gets to some limit in there. + +Just keep your eye on the pressure. + +Make sure the pressure doesn't get too high. + +Well, of course the pressure isn't going to +get too high because the vent is open. + +So we said fine. + +We turned the ground power supplies on and +let the thing cook for 10 to 12 hours. + +And what we didn't know was that the thermostat +wasn't certified to the voltage we were using + +from our ground power supplies because we +didn't tell them, although our requirements + +allowed it, that we cranked the power supplies +up to 50 volts. + +And why did we do that? + +Well, the more energy you put into the tank +the higher the heaters get and the quicker + +the liquid oxygen boils off. + +You know, high school physics. + +But we didn't tell them that. + +And the people that built the tank and built +that thermostat had only certified it to the + +voltage of fuel cell supply which is half +that value. + +So the thermostat welded together, the points +did, and we had continuous power going on + +in there for eight to ten hours. + +It got to 800, 900 degrees in the tank. + +We burned all the insulation off the wires +to the fans and the heaters. + +And, from that point on, we were just waiting +for something to happen to make those wires + +come together. + +And if you didn't turn the power on you're +going to get a spark in an oxygen tank. + +Not a good thing. + +Well, that is what happened a day into the +mission when they were heading to the moon. + +And they turned the heaters and the fans on +to stir the cryogenics because they were worried + +about stratification and zero gravity. + +And they got the spark and it blew up the +service module. + +The point is that communication, we wrote +down in our procedures what we did, but we + +didn't communicate that on a real-time basis. + +And, although we reviewed the procedures afterward, +as the rest of the team did, the designer + +who was 1500 miles away who had approved what +we did over an intercom system didn't review + +our paperwork. + +You hit that thing with 50 volts, it's only +certified for 25 volts, even though our requirements + +allowed us to use 50 volts. + +It is a case where requirements didn't preclude +us from launching hardware then in hindsight + +was flawed. + +But, on the other hand, communication, we +didn't tell them in real-time. + +And, as a result, Apollo 13 happened. + +So I learned that lesson early on. + +I mean even if you're boring them with what +appears to be minutia, you're going to tell + +them everything and document everything. + +And, thankfully, they went through our procedures +and said well, there it is. + +And I thought we'd get fired. + +And actually we got patted on the back for +documenting what we had done so it made it + +easier to zero in on the root cause of the +problem. + +And, as a result, we fixed that and we were +able to fly again in a few months as opposed + +to having to go through a Challenger or Columbia +type of activity. + +Very important. + +Launch fever. + +The human factor. + +It is hard to describe what the environment +is in the spacecraft a few minutes before + +launch or in the Control Room. + +But there is a lot of tension and there is +a lot of energy. + +And everybody in there, for the most part, +has been awake for the last 10 to 12 hours. + +And they came to work that day or that night +with all hopes of safely launching the Space + +Shuttle. + +And they really don't want anything to go +wrong with their system or somebody else's + +system. + +I mean that's the mood. + +Because, if something goes wrong, you're going +to come back tomorrow or the next day or the + +next week. + +So they really want to hear this everybody, +you know, when they do the polls they go, + +go, go, go. + +And the hardest thing is saying no when everything +sounds like it's go. + +And there are a lot of times when we've had +problems with ground support equipment. + +It is old. + +I wish we had all new stuff for Shuttle. + +A lot of this stuff is the same we used on +Apollo. + +And, in spite of our efforts to maintain it, +it is all out in the corrosive atmosphere + +at the launch pad. + +And that stuff constantly gave us problems. + +And we would lose some of our redundant systems +and some of our primary systems. + +And more than once in launch count, when we'd +have a problem out there, the team would come + +to the launch director through that organization +chart you saw and say we've got an idea. + +We think if we patch around this and then +hook this up to this and we throw these switches + +and we get this result that it will be OK +and we can go fly without this power supply + +being active or this purge system operating +normally and all these other things that we've + +got out there. + +And what you have to do as launch director +is say well, just sit back and analyze whether + +or not -- I mean you rely on your engineers +to use their Yankee ingenuity to fix a problem, + +but you have to assess whether or not they're +literally shot-gunning it and coming up with + +the proverbial quick fix because they want +to go home in an hour or so and celebrate + +a good launch. + +Just like these guys want to get out of those +uncomfortable suits they have been sitting + +in for the last couple hours and either get +out of the spacecraft or get up there in zero + +G. + +As a launch director, you have to assess well, +OK, but is this really the right thing to + +do or are they working this too hard? + +If you gave them another 24 hours to look +at the data and think about their approach + +to a fix would the answer be any different? + +And there have been a few times when they +said well, that sounds pretty good right now + +but I am going to give you another 24 hours +to think about it so we're going to scrub + +for the day. + +And you can hear the big groan in the Control +Room. + +And you can just see it going through their +heads, well, this guy has lost confidence + +in us. + +I mean we all came to work, we get paid to +solve problems and get things done, and he + +is telling us that ain't a good answer, that +ain't a good fix. + +So you have to balance that when you're in +charge, but the real job of the launch director + +is to say no when everybody else wants to +go. + +That is really what you are there for. + +Because these guys get tunnel vision. + +They want to go fly. + +The console operators, things are on automatic +in that last nine minutes, and they just hope + +they don't get that little red or yellow light +on their screen that says hey, you better + +go look at this, it isn't working right. + +The last people you want to ask is it OK to +launch is the crew. + +They'll say yes, no matter what is happening. + +And we do ask them, by the way, but it is +a formality because we know what the answer + +is. + +Unless he's got a fire extinguisher up there +putting out something in the spacecraft, he + +is going to say we're go. + +And that is also why we put in a rule that +says after five minutes, for these critical + +launch commit criteria items, the 500 that +you absolutely have to look at and certify, + +you don't proposition us with a change to +that after five minutes because we're not + +going to entertain it. + +If they're out of limits we're not going today +or tonight. + +It is going to be at least 24 hours. + +A long time. + +But the team that does it, I mean they are +good, they are professionals. + +And we talk a lot about the Apollo program +and how great things were back then, but I + +just gave you the example of Apollo 13. + +The Shuttle team versus the Apollo team has +a much higher degree of difficulty situation + +to deal with. + +There are fewer people on Shuttle, yet it's +a more complex vehicle than the whole Apollo + +system. + +The Saturn 5 rocket and the spacecraft were +simple compared to the Shuttle system. + +And we had 25,000 people at the Cape in the +Apollo program flying two to three times a + +year. + +And in the Shuttle program back in the early +'90s we flew seven times a year with 6,000 + +people with a vehicle that is more complex, +older. + +In the Apollo program our ground equipment +was new and all the flight hardware was new. + +It wasn't reused. + +It was fresh out of the box factory pristine +stuff. + +And requirements were easy, you know, it had +to act and look brand-new or you replaced + +it. + +The Shuttle, because it is 20, 30 years old, +depending on which orbiter and the ground + +equipment which is 30 to 40 years old, there +are requirements that allow fair wear and + +tear. + +The engineers are constantly pushed with is +this good enough? + +These wire bundles are frayed and there are +dings in this line and that weld is looking + +like it has corrosion on it, is it good enough? + +Well, they are constantly propositioning where +back in the Apollo program you didn't have + +to mess with that gray area stuff. + +It either looked or acted brand-new or you +replaced it. + +And replacing it was easy because money was +unlimited. + +As a journeyman engineer on Apollo I was told +whatever you need you can have. + +System engineers seek more test equipment, +you need more technicians to be trained on + +this over here, whatever you need just ask +for it. + +Money is not an object. + +As a manager on the Shuttle program when I +finally got promoted out of the job I liked + +to launch director, I had to tell the journeymen +engineers this is all the money you get for + +next year. + +And be real efficient with this and frugal +because next year you're probably going to + +get less. + +And your strategy and approach to issues is +much different if you have those two different + +environments to deal with. + +And finally the other thing that Shuttle deals +with today versus Apollo is the acceptance + +of risk. + +I mean I already mentioned Apollo 13. + +Back then if you made a mistake you were patted +on the back and told hey, nice try. + +Now, is there anything that can be done to +better enhance your probability of success? + +Whereas, in the Shuttle program, risk aversion +in this country, I don't want to get started + +on that tangent, is becoming more and more +a lifestyle. + +We don't want to do things we might lose or +we might not win or we may not be successful. + +And risk, you know, there is less tolerance +to it. + +And, when you have a problem like Columbia +or Challenger, you get half a dozen boarding + +parties coming into NASA saying here is what +you need to do differently or this is wrong + +with your agency and this and this and you +need to go fix that. + +And, again, back in Apollo, it was what do +you need to be successful? + +Much different. + +And it makes it difficult to operate. + +Bob, could you comment upon risk aversion +and the launch director and whether there + +were more aggressive and more conservative +people who have had your job? + +Well, I would say, before I was launch director, +there was one. + +And he was more aggressive than I was. + +He was the console MANOPS person. + +And he would push, and he would push until +you would say uncle, I surrender or whatever, + +and then he would make a judgment call. + +I was more conservative than that. + +I trained the one immediately after me. + +And he was pretty much the same but he got +the highly visible job, management say that + +this guy was good, we'll take him away from +here and go put him over here managing this + +large organization and worrying about budgets +and contracts. + +That is the same thing that happened to me. + +And that's unfortunate, but NASA's strongest +suit is not succession planning, unfortunately. + +It just isn't. + +Yes? + +Are you saying the Shuttle program is too +risk averse? + +Because you also said that, for example, it +is your job as launch director to be conservative + +and to say no when everyone else is saying +yes. + +No, I wouldn't say that the Shuttle program +is risk adverse. + +I would say our society is risk adverse. + +And you see some of that permeating into the +Shuttle program, but not to the point where + +I would say it is detrimental. + +I mean asking questions, digging in to understand +what your risks are is an important thing + +to do. + +And early in the Shuttle program we didn't +do that. + +We had a lot of confidence in hardware after +the first few missions. + +It's just like a new car. + +You put 5000 miles on it, you get the bugs +out of it and you fully expect it to last + +another so many hundred thousand miles. + +Well, that was the same expectation in the +Shuttle program. + +You fly a few flights and you learn that the +tiles really stayed glued to the Orbiter and + +the thermal control system really responds +as it should on orbit and managing the temperature + +and the coolant leaks and that sort of thing. + +And you build up confidence and you say it +should work now. + +We got the bugs out of it and we can go fly +this thing as often as those guys at the Cape + +can turn it around. + +But what they didn't consider and what all +these engineers, with all due respect that + +you heard from that certify their systems, +they didn't totally capture the environment + +that the Shuttle sees over the long period +of time in their initial certification. + +They didn't capture it. + +And that environment includes not only what +happens in space or the calendar exposure + +to just time on some of these systems that +have soft goods in them, for instance, O rings + +and that sort of thing, but it is the environment +of the Cape with people constantly removing + +hardware, disconnecting things, moving wire +bundles out of the way to get access to this + +or that other component to implement the requirements +that were levied on the Cape to do the tests + +and inspections. + +And they are very invasive, and collateral +damage is a way of life when you're crawling + +around in the Orbiter. + +To put in policy that tries to compensate +for the fact that the certification didn't + +capture that environment that this hardware +has seen for the last 20 to 30 years, to reduce + +the unknowns involved in that, that is the +right thing to do. + +You're trying to reduce the risk of reflying +a very complex vehicle. + +So that is fine, but you take that to a limit. + +I mean you can talk yourself into never flying +which would be pretty easy to go do. + +And then this recovery after the Columbia +accident, that was starting to happen. + +The managers, because they had this investigation +board report that says NASA, you've become + +complacent and overconfident. + +And, by the way, in my opinion that is somewhat +of a bum rap to say that NASA in general, + +and particularly the Shuttle program, had +fallen into that mode. + +But, to have the pendulum swing the other +way to understand what your risks are and + +then you can have knowledge on whether you +decide to accept it or not, that is a good + +thing. + +What didn't happen after Columbia, but we +did do after Challenger, is after we understood + +the root cause of the accident and some of +the other factors like communication that + +we're part of that, reviewed all the systems +and all the requirements, the managers said + +look, we're willing to accept some risk. + +You people who are responsible for these systems +and these processes at the Cape, you need + +to quantify that for us and bring it to us. + +And we will either say OK, we won't accept +that, you go back and change your system or + +change your limits or do more tests or whatever, +or we will accept it. + +We will say we'll accept that risk, management +will accept some risk. + +That happened after Challenger, and we were +able to fly again roughly two years later + +after we recertified the design to the solid +rocket motors. + +That didn't happen after Columbia. + +And you can speculate whether or not we could +have flown six months ago or a year ago or + +we should have waited longer to fly because +we still had a piece of foam come off the + +tank. + +You could debate that. + +But management never acknowledged that they +were willing to accept some risk after Columbia. + +They did say tell us what the risk is but +we really want you to crank it down to zero. + +We don't want to take any risk, unlike Challenger. + +Now, is that bad? + +See, what really happened with Columbia was +the mission management team's discipline had + +eroded. + +There were communication issues. + +And, if you're a student of that investigation, +they didn't grade out very well. + +But the investigation said there is complacency +and overconfidence in the system. + +Well, having been part of the system prior +to my retirement five years ago, you never + +found any complacency or overconfidence with +the engineers, technicians, inspectors or + +the managers that I knew. + +Now, they weren't as smart as they thought +they were or, in some cases, as smart as they + +needed to be. + +But that is not the same as complacency or +overconfidence. + +Because the latter to me implies an attitude +problem that I've got it, I know it all, I + +am smart as I need to be. + +And, for the most part, you know, there were +some people I didn't like because I thought + +he or she was arrogant or something like that, +but I never sensed an attitude problem with + +the Shuttle team. + +From the technicians, many of which I knew +and grew up with, to the top managers in the + +Shuttle program, I never sensed that. + +But were we not as smart as we thought we +were or as smart as we needed to be? + +Were there signs that there was something +going on here that you ought to go fix? + +Yes. + +But, again, they didn't just blow off, so +to speak, these problems we were having with + +foam on the tank and these other systems which, +to me, would have been complacency or overconfidence. + +Anything else? + +We're just about out of time. + +I've got two announcements. + +I've been working with the Stellar people. + +As you know, some of the pdf files that I've +tried to load didn't load. + +They cannot really figure out why, but I have +sent them the files, they've loaded most of + +them on so hopefully almost everything is +there. + +We're continuing to work at it, but hopefully +all the things that you need access to you + +can find. + +I said there were two things, but that's the +only one I remember. + +Well, let me close with one note then. + +I am glad you're here. + +Thanks for your choice to pursue an engineering +career. + +Doing things that are hard, I have found that +in my travels that unfortunately there are + +fewer people deciding to pursue the tough +curriculums and the occupations that require + +a lot of work and have some risk associated +with them. + +But it is encouraging to see people in graduate +school that want to do what I did. + +I am not sure how much engineering I did in +my 40 year career. + +I did a lot of managing and a lot of other +assignments, but I am sure you can accomplish + +a lot. + +I had a grandmother who was born at the end +of the 19th century. + +And, when she was your age, there weren't +any computers, airplanes, cars, TV and that + +sort of thing. + +Yet, in her lifetime, she got to see her favorite +grandson, Bobby, help put a man on the moon. + +And I don't know what can be done in your +lifetime, but you can make great things happen + +with the career you have chosen. + +So thanks for choosing, really. + +Bob, thanks very much. + +A pleasure. + +[APPLAUSE] \ No newline at end of file diff --git a/uyNj56g5rHY.txt b/uyNj56g5rHY.txt new file mode 100644 index 0000000000000000000000000000000000000000..11f350d718511c06c8216cfbb979e06622cddba9 --- /dev/null +++ b/uyNj56g5rHY.txt @@ -0,0 +1,731 @@ +align:start position:0% + +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +[Applause] + + align:start position:0% + + + + align:start position:0% + +What are you working on? I've got a + + align:start position:0% +What are you working on? I've got a + + + align:start position:0% +What are you working on? I've got a +great new idea. I'm going to make cocoa + + align:start position:0% +great new idea. I'm going to make cocoa + + + align:start position:0% +great new idea. I'm going to make cocoa +beans that reproduce as fast as viruses. + + align:start position:0% +beans that reproduce as fast as viruses. + + + align:start position:0% +beans that reproduce as fast as viruses. +That way, we'll have enough cocoa beans + + align:start position:0% +That way, we'll have enough cocoa beans + + + align:start position:0% +That way, we'll have enough cocoa beans +to make as much chocolate as we want. + + align:start position:0% +to make as much chocolate as we want. + + + align:start position:0% +to make as much chocolate as we want. +You know how much I like chocolate. + + align:start position:0% +You know how much I like chocolate. + + + align:start position:0% +You know how much I like chocolate. +Explain your project a little more. How + + align:start position:0% +Explain your project a little more. How + + + align:start position:0% +Explain your project a little more. How +are you going to engineer this yummy + + align:start position:0% +are you going to engineer this yummy + + + align:start position:0% +are you going to engineer this yummy +idea? Well, viruses reproduce really + + align:start position:0% +idea? Well, viruses reproduce really + + + align:start position:0% +idea? Well, viruses reproduce really +fast, so I thought that I could take + + align:start position:0% +fast, so I thought that I could take + + + align:start position:0% +fast, so I thought that I could take +that part from a virus and put it into a + + align:start position:0% +that part from a virus and put it into a + + + align:start position:0% +that part from a virus and put it into a +cocoa plant. Plants are pretty safe to + + align:start position:0% +cocoa plant. Plants are pretty safe to + + + align:start position:0% +cocoa plant. Plants are pretty safe to +work with, but viruses can be dangerous. + + align:start position:0% +work with, but viruses can be dangerous. + + + align:start position:0% +work with, but viruses can be dangerous. +Which virus were you thinking about + + align:start position:0% +Which virus were you thinking about + + + align:start position:0% +Which virus were you thinking about +using? Well, I read that Ebola virus has + + align:start position:0% +using? Well, I read that Ebola virus has + + + align:start position:0% +using? Well, I read that Ebola virus has +a short sequence that Ebola Ebola is a + + align:start position:0% +a short sequence that Ebola Ebola is a + + + align:start position:0% +a short sequence that Ebola Ebola is a +biosafety level four agent. Well, the + + align:start position:0% +biosafety level four agent. Well, the + + + align:start position:0% +biosafety level four agent. Well, the +worst are level five, so I thought it + + align:start position:0% +worst are level five, so I thought it + + + align:start position:0% +worst are level five, so I thought it +was safe enough. Level five? There is no + + align:start position:0% +was safe enough. Level five? There is no + + + align:start position:0% +was safe enough. Level five? There is no +biosafety level five. You'd need lots + + align:start position:0% +biosafety level five. You'd need lots + + + align:start position:0% +biosafety level five. You'd need lots +and lots of training to work in any + + align:start position:0% +and lots of training to work in any + + + align:start position:0% +and lots of training to work in any +level three or four facility and you'd + + align:start position:0% +level three or four facility and you'd + + + align:start position:0% +level three or four facility and you'd +have to wait a few years since they + + align:start position:0% +have to wait a few years since they + + + align:start position:0% +have to wait a few years since they +don't let miners in those labs. But + + align:start position:0% +don't let miners in those labs. But + + + align:start position:0% +don't let miners in those labs. But +there was this show on TV where they + + align:start position:0% +there was this show on TV where they + + + align:start position:0% +there was this show on TV where they +what you see on TV and in movies can be + + align:start position:0% +what you see on TV and in movies can be + + + align:start position:0% +what you see on TV and in movies can be +very deceiving. But let's talk about all + + align:start position:0% +very deceiving. But let's talk about all + + + align:start position:0% +very deceiving. But let's talk about all +the biosafety levels. If we're going to + + align:start position:0% +the biosafety levels. If we're going to + + + align:start position:0% +the biosafety levels. If we're going to +make your viral cocoa beans, we need to + + align:start position:0% +make your viral cocoa beans, we need to + + + align:start position:0% +make your viral cocoa beans, we need to +come up with a way that keeps everyone + + align:start position:0% +come up with a way that keeps everyone + + + align:start position:0% +come up with a way that keeps everyone +safe inside the lab and outside too. + + align:start position:0% +safe inside the lab and outside too. + + + align:start position:0% +safe inside the lab and outside too. +Okay, I do know that biosafety is a + + align:start position:0% +Okay, I do know that biosafety is a + + + align:start position:0% +Okay, I do know that biosafety is a +combination of safe lab practices and + + align:start position:0% +combination of safe lab practices and + + + align:start position:0% +combination of safe lab practices and +techniques. wearing the right safety + + align:start position:0% +techniques. wearing the right safety + + + align:start position:0% +techniques. wearing the right safety +equipment and working in a lab designed + + align:start position:0% +equipment and working in a lab designed + + + align:start position:0% +equipment and working in a lab designed +to contain the experiment. But with + + align:start position:0% +to contain the experiment. But with + + + align:start position:0% +to contain the experiment. But with +biosafety level one, that just means a + + align:start position:0% +biosafety level one, that just means a + + + align:start position:0% +biosafety level one, that just means a +room with screened windows and a door + + align:start position:0% +room with screened windows and a door + + + align:start position:0% +room with screened windows and a door +that closes. That doesn't sound like + + align:start position:0% +that closes. That doesn't sound like + + + align:start position:0% +that closes. That doesn't sound like +much. That's because BL1 experiments use + + align:start position:0% +much. That's because BL1 experiments use + + + align:start position:0% +much. That's because BL1 experiments use +only well-characterized microbes that + + align:start position:0% +only well-characterized microbes that + + + align:start position:0% +only well-characterized microbes that +don't make a healthy person sick. But + + align:start position:0% +don't make a healthy person sick. But + + + align:start position:0% +don't make a healthy person sick. But +remember, there's no eating or drinking + + align:start position:0% +remember, there's no eating or drinking + + + align:start position:0% +remember, there's no eating or drinking +in the lab since you wouldn't want to + + align:start position:0% +in the lab since you wouldn't want to + + + align:start position:0% +in the lab since you wouldn't want to +eat your experiments. When do I get to + + align:start position:0% +eat your experiments. When do I get to + + + align:start position:0% +eat your experiments. When do I get to +wear a lab coat like yours? If you're + + align:start position:0% +wear a lab coat like yours? If you're + + + align:start position:0% +wear a lab coat like yours? If you're +working at biosafety level two, you'll + + align:start position:0% +working at biosafety level two, you'll + + + align:start position:0% +working at biosafety level two, you'll +have to wear it. and gloves, too. Since + + align:start position:0% +have to wear it. and gloves, too. Since + + + align:start position:0% +have to wear it. and gloves, too. Since +some BL2 agents can be infectious, BL2 + + align:start position:0% +some BL2 agents can be infectious, BL2 + + + align:start position:0% +some BL2 agents can be infectious, BL2 +labs have impervious benches, and most + + align:start position:0% +labs have impervious benches, and most + + + align:start position:0% +labs have impervious benches, and most +of the work is done in biological safety + + align:start position:0% +of the work is done in biological safety + + + align:start position:0% +of the work is done in biological safety +cabinets. Lots of BL2 workers also get + + align:start position:0% +cabinets. Lots of BL2 workers also get + + + align:start position:0% +cabinets. Lots of BL2 workers also get +immunizations if they'll be working with + + align:start position:0% +immunizations if they'll be working with + + + align:start position:0% +immunizations if they'll be working with +certain agents. I hate getting shots. + + align:start position:0% +certain agents. I hate getting shots. + + + align:start position:0% +certain agents. I hate getting shots. +Well, not all level two agents require + + align:start position:0% +Well, not all level two agents require + + + align:start position:0% +Well, not all level two agents require +immunizations. Really, the rules for BL1 + + align:start position:0% +immunizations. Really, the rules for BL1 + + + align:start position:0% +immunizations. Really, the rules for BL1 +and BL2 are pretty basic because the + + align:start position:0% +and BL2 are pretty basic because the + + + align:start position:0% +and BL2 are pretty basic because the +agents have minimal risk associated with + + align:start position:0% +agents have minimal risk associated with + + + align:start position:0% +agents have minimal risk associated with +them. But let's think for a minute about + + align:start position:0% +them. But let's think for a minute about + + + align:start position:0% +them. But let's think for a minute about +what biosafety you'd need for your + + align:start position:0% +what biosafety you'd need for your + + + align:start position:0% +what biosafety you'd need for your +mashup of a virus with a cocoa plant. + + align:start position:0% +mashup of a virus with a cocoa plant. + + + align:start position:0% +mashup of a virus with a cocoa plant. +Well, maybe more protective clothes like + + align:start position:0% +Well, maybe more protective clothes like + + + align:start position:0% +Well, maybe more protective clothes like +the workers in biosafety level 3 labs. + + align:start position:0% +the workers in biosafety level 3 labs. + + + align:start position:0% +the workers in biosafety level 3 labs. +They wear full suits and maybe masks or + + align:start position:0% +They wear full suits and maybe masks or + + + align:start position:0% +They wear full suits and maybe masks or +something. It's nothing I can't handle. + + align:start position:0% +something. It's nothing I can't handle. + + + align:start position:0% +something. It's nothing I can't handle. +Imagine me in a space suit. Very cool. + + align:start position:0% +Imagine me in a space suit. Very cool. + + + align:start position:0% +Imagine me in a space suit. Very cool. +And think about how much chocolate we'll + + align:start position:0% +And think about how much chocolate we'll + + + align:start position:0% +And think about how much chocolate we'll +have. Earth to dude. Level three agents + + align:start position:0% +have. Earth to dude. Level three agents + + + align:start position:0% +have. Earth to dude. Level three agents +are very serious, potentially lethal. + + align:start position:0% +are very serious, potentially lethal. + + + align:start position:0% +are very serious, potentially lethal. +And level four agents like Ebola virus + + align:start position:0% +And level four agents like Ebola virus + + + align:start position:0% +And level four agents like Ebola virus +have such a high lethal risk that there + + align:start position:0% +have such a high lethal risk that there + + + align:start position:0% +have such a high lethal risk that there +are only a few places in the world where + + align:start position:0% +are only a few places in the world where + + + align:start position:0% +are only a few places in the world where +they're studied. Restrictions for + + align:start position:0% +they're studied. Restrictions for + + + align:start position:0% +they're studied. Restrictions for +working with these agents are very + + align:start position:0% +working with these agents are very + + + align:start position:0% +working with these agents are very +tight. Everything entering or leaving + + align:start position:0% +tight. Everything entering or leaving + + + align:start position:0% +tight. Everything entering or leaving +BL3 and BL4 labs has to be + + align:start position:0% +BL3 and BL4 labs has to be + + + align:start position:0% +BL3 and BL4 labs has to be +decontaminated. Sometimes the lab has to + + align:start position:0% +decontaminated. Sometimes the lab has to + + + align:start position:0% +decontaminated. Sometimes the lab has to +be in its own building to control foot + + align:start position:0% +be in its own building to control foot + + + align:start position:0% +be in its own building to control foot +traffic. I know I don't want to work + + align:start position:0% +traffic. I know I don't want to work + + + align:start position:0% +traffic. I know I don't want to work +where there are double door entries and + + align:start position:0% +where there are double door entries and + + + align:start position:0% +where there are double door entries and +airlock rooms. I think that sounds like + + align:start position:0% +airlock rooms. I think that sounds like + + + align:start position:0% +airlock rooms. I think that sounds like +fun. If you're so excited about the + + align:start position:0% +fun. If you're so excited about the + + + align:start position:0% +fun. If you're so excited about the +protective clothing, we can always be + + align:start position:0% +protective clothing, we can always be + + + align:start position:0% +protective clothing, we can always be +overly cautious in a level one or two + + align:start position:0% +overly cautious in a level one or two + + + align:start position:0% +overly cautious in a level one or two +facility. But can't we find another way + + align:start position:0% +facility. But can't we find another way + + + align:start position:0% +facility. But can't we find another way +to make more cocoa beans? Okay, maybe we + + align:start position:0% +to make more cocoa beans? Okay, maybe we + + + align:start position:0% +to make more cocoa beans? Okay, maybe we +can find another virus that's not so + + align:start position:0% +can find another virus that's not so + + + align:start position:0% +can find another virus that's not so +dangerous and we can keep working on + + align:start position:0% +dangerous and we can keep working on + + + align:start position:0% +dangerous and we can keep working on +your chocolate idea. Let's start looking + + align:start position:0% +your chocolate idea. Let's start looking + + + align:start position:0% +your chocolate idea. Let's start looking +in here. \ No newline at end of file diff --git a/uyz1UQEu-kk.txt b/uyz1UQEu-kk.txt new file mode 100644 index 0000000000000000000000000000000000000000..077ce6c6d1fc3ca229cf01680f842223c3a2ecd8 --- /dev/null +++ b/uyz1UQEu-kk.txt @@ -0,0 +1,8283 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common License. Your support + + align:start position:0% +a Creative Common License. Your support + + + align:start position:0% +a Creative Common License. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer high-quality educational + + align:start position:0% +to offer high-quality educational + + + align:start position:0% +to offer high-quality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or view additional materials from + + align:start position:0% +or view additional materials from + + + align:start position:0% +or view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +I uh gave you an extension for your + + align:start position:0% +I uh gave you an extension for your + + + align:start position:0% +I uh gave you an extension for your +paper Wednesday, so you don't have to + + align:start position:0% +paper Wednesday, so you don't have to + + + align:start position:0% +paper Wednesday, so you don't have to +ask. It's just automatic. If you want to + + align:start position:0% +ask. It's just automatic. If you want to + + + align:start position:0% +ask. It's just automatic. If you want to +give it to me today, that's fine, too. + + align:start position:0% +give it to me today, that's fine, too. + + + align:start position:0% +give it to me today, that's fine, too. +Uh everybody's busy this time of year, + + align:start position:0% +Uh everybody's busy this time of year, + + + align:start position:0% +Uh everybody's busy this time of year, +so I try to leave a little flexibility + + align:start position:0% +so I try to leave a little flexibility + + + align:start position:0% +so I try to leave a little flexibility +in there. If Wednesday doesn't work for + + align:start position:0% +in there. If Wednesday doesn't work for + + + align:start position:0% +in there. If Wednesday doesn't work for +you, talk to me after class. Uh, I don't + + align:start position:0% +you, talk to me after class. Uh, I don't + + + align:start position:0% +you, talk to me after class. Uh, I don't +like to have you lag too far behind + + align:start position:0% +like to have you lag too far behind + + + align:start position:0% +like to have you lag too far behind +because then it kind of messes up other + + align:start position:0% +because then it kind of messes up other + + + align:start position:0% +because then it kind of messes up other +stuff that you have to do. I'd rather + + align:start position:0% +stuff that you have to do. I'd rather + + + align:start position:0% +stuff that you have to do. I'd rather +have you do something maybe less + + align:start position:0% +have you do something maybe less + + + align:start position:0% +have you do something maybe less +perfect, but get it in on time so you + + align:start position:0% +perfect, but get it in on time so you + + + align:start position:0% +perfect, but get it in on time so you +can, you know, MIT has always uh got 15 + + align:start position:0% +can, you know, MIT has always uh got 15 + + + align:start position:0% +can, you know, MIT has always uh got 15 +things for you to do every time you turn + + align:start position:0% +things for you to do every time you turn + + + align:start position:0% +things for you to do every time you turn +around. So, + + align:start position:0% +around. So, + + + align:start position:0% +around. So, +uh, okay. So we are now uh looking at + + align:start position:0% +uh, okay. So we are now uh looking at + + + align:start position:0% +uh, okay. So we are now uh looking at +some a number of works uh post Darwinian + + align:start position:0% +some a number of works uh post Darwinian + + + align:start position:0% +some a number of works uh post Darwinian +works works that came out after the + + align:start position:0% +works works that came out after the + + + align:start position:0% +works works that came out after the +origin. Not that they wouldn't have come + + align:start position:0% +origin. Not that they wouldn't have come + + + align:start position:0% +origin. Not that they wouldn't have come +out without the origin, but certainly + + align:start position:0% +out without the origin, but certainly + + + align:start position:0% +out without the origin, but certainly +this book wouldn't have. This book uh + + align:start position:0% +this book wouldn't have. This book uh + + + align:start position:0% +this book wouldn't have. This book uh +Butler's Arowan uh which is nowhere + + align:start position:0% +Butler's Arowan uh which is nowhere + + + align:start position:0% +Butler's Arowan uh which is nowhere +spelled backwards more or less + + align:start position:0% +spelled backwards more or less + + + align:start position:0% +spelled backwards more or less +uh is a uh it's a type of utopia, what + + align:start position:0% +uh is a uh it's a type of utopia, what + + + align:start position:0% +uh is a uh it's a type of utopia, what +we call a + + align:start position:0% +we call a + + + align:start position:0% +we call a +dystopia, and it's kind of riffing and + + align:start position:0% +dystopia, and it's kind of riffing and + + + align:start position:0% +dystopia, and it's kind of riffing and +playing with some of the ideas of + + align:start position:0% +playing with some of the ideas of + + + align:start position:0% +playing with some of the ideas of +evolution. Uh, and it is a satire. So, + + align:start position:0% +evolution. Uh, and it is a satire. So, + + + align:start position:0% +evolution. Uh, and it is a satire. So, +satires are hard for people to read. Uh, + + align:start position:0% +satires are hard for people to read. Uh, + + + align:start position:0% +satires are hard for people to read. Uh, +a lot of people just don't quite get the + + align:start position:0% +a lot of people just don't quite get the + + + align:start position:0% +a lot of people just don't quite get the +satire because, you know, it seems to be + + align:start position:0% +satire because, you know, it seems to be + + + align:start position:0% +satire because, you know, it seems to be +saying things that are totally + + align:start position:0% +saying things that are totally + + + align:start position:0% +saying things that are totally +outrageous and yet it's saying them that + + align:start position:0% +outrageous and yet it's saying them that + + + align:start position:0% +outrageous and yet it's saying them that +are in a way that's tongue and cheek. + + align:start position:0% +are in a way that's tongue and cheek. + + + align:start position:0% +are in a way that's tongue and cheek. +And so with Butler, you have to sort of + + align:start position:0% +And so with Butler, you have to sort of + + + align:start position:0% +And so with Butler, you have to sort of +think a little bit before you interpret + + align:start position:0% +think a little bit before you interpret + + + align:start position:0% +think a little bit before you interpret +what he's saying literally because there + + align:start position:0% +what he's saying literally because there + + + align:start position:0% +what he's saying literally because there +all kinds of uh weird little uh + + align:start position:0% +all kinds of uh weird little uh + + + align:start position:0% +all kinds of uh weird little uh +uh + + align:start position:0% +uh + + + align:start position:0% +uh +uh behaviors in the book uh uh among the + + align:start position:0% +uh behaviors in the book uh uh among the + + + align:start position:0% +uh behaviors in the book uh uh among the +people that uh uh this this uh uh + + align:start position:0% +people that uh uh this this uh uh + + + align:start position:0% +people that uh uh this this uh uh +voyager, this traveler discovers. So, + + align:start position:0% +voyager, this traveler discovers. So, + + + align:start position:0% +voyager, this traveler discovers. So, +uh, I thought maybe it'd be helpful for + + align:start position:0% +uh, I thought maybe it'd be helpful for + + + align:start position:0% +uh, I thought maybe it'd be helpful for +us to say a little bit, uh, about + + align:start position:0% +us to say a little bit, uh, about + + + align:start position:0% +us to say a little bit, uh, about +utopias before we read the, uh, before + + align:start position:0% +utopias before we read the, uh, before + + + align:start position:0% +utopias before we read the, uh, before +we get into the book. + + align:start position:0% +we get into the book. + + + align:start position:0% +we get into the book. +Um, so what do you know about + + align:start position:0% +Um, so what do you know about + + + align:start position:0% +Um, so what do you know about +utopias? Have you read a few of them or + + align:start position:0% +utopias? Have you read a few of them or + + + align:start position:0% +utopias? Have you read a few of them or +you've come across them + + align:start position:0% +you've come across them + + + align:start position:0% +you've come across them +before? I mean, I I would love to teach + + align:start position:0% +before? I mean, I I would love to teach + + + align:start position:0% +before? I mean, I I would love to teach +a course just on utopias because it's a + + align:start position:0% +a course just on utopias because it's a + + + align:start position:0% +a course just on utopias because it's a +fascinating type of uh, literature. But + + align:start position:0% +fascinating type of uh, literature. But + + + align:start position:0% +fascinating type of uh, literature. But +uh what are some of the uh what are the + + align:start position:0% +uh what are some of the uh what are the + + + align:start position:0% +uh what are some of the uh what are the +things? Has anybody read any utopias or + + align:start position:0% +things? Has anybody read any utopias or + + + align:start position:0% +things? Has anybody read any utopias or +dystopias? + + align:start position:0% +dystopias? + + + align:start position:0% +dystopias? +What's that? Okay. Elorado and Volter + + align:start position:0% +What's that? Okay. Elorado and Volter + + + align:start position:0% +What's that? Okay. Elorado and Volter +was a a little a little chapter of a + + align:start position:0% +was a a little a little chapter of a + + + align:start position:0% +was a a little a little chapter of a +utopia. + + align:start position:0% +utopia. + + + align:start position:0% +utopia. +Is that a single working example? Yeah. + + align:start position:0% +Is that a single working example? Yeah. + + + align:start position:0% +Is that a single working example? Yeah. +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Okay. Uh what uh + + align:start position:0% +Okay. Uh what uh + + + align:start position:0% +Okay. Uh what uh +I mean most of you have read 1984 I I + + align:start position:0% +I mean most of you have read 1984 I I + + + align:start position:0% +I mean most of you have read 1984 I I +assume or uh Animal Farm. Yeah, these + + align:start position:0% +assume or uh Animal Farm. Yeah, these + + + align:start position:0% +assume or uh Animal Farm. Yeah, these +are inverted utopias. These are what we + + align:start position:0% +are inverted utopias. These are what we + + + align:start position:0% +are inverted utopias. These are what we +call + + align:start position:0% +call + + + align:start position:0% +call +dystopias. Uh they use some of the rules + + align:start position:0% +dystopias. Uh they use some of the rules + + + align:start position:0% +dystopias. Uh they use some of the rules +of utopia, but they present a world that + + align:start position:0% +of utopia, but they present a world that + + + align:start position:0% +of utopia, but they present a world that +is highly + + align:start position:0% +is highly + + + align:start position:0% +is highly +undesirable. But people have been + + align:start position:0% +undesirable. But people have been + + + align:start position:0% +undesirable. But people have been +writing utopias for hundreds of years. + + align:start position:0% +writing utopias for hundreds of years. + + + align:start position:0% +writing utopias for hundreds of years. +And uh what is uh + + align:start position:0% +And uh what is uh + + + align:start position:0% +And uh what is uh +so just to + + align:start position:0% +so just to + + + align:start position:0% +so just to +um some of the I just sent these to you + + align:start position:0% +um some of the I just sent these to you + + + align:start position:0% +um some of the I just sent these to you +just to give you some things to think + + align:start position:0% +just to give you some things to think + + + align:start position:0% +just to give you some things to think +about. These were in a packet I sent + + align:start position:0% +about. These were in a packet I sent + + + align:start position:0% +about. These were in a packet I sent +out. + + align:start position:0% +out. + + + align:start position:0% +out. +Um but a lot of them play with ideas. + + align:start position:0% +Um but a lot of them play with ideas. + + + align:start position:0% +Um but a lot of them play with ideas. +They're idea. They're works of ideas. + + align:start position:0% +They're idea. They're works of ideas. + + + align:start position:0% +They're idea. They're works of ideas. +works in which people + + align:start position:0% +works in which people + + + align:start position:0% +works in which people +uh think about idealized societies of + + align:start position:0% +uh think about idealized societies of + + + align:start position:0% +uh think about idealized societies of +various sorts. Uh and there are some + + align:start position:0% +various sorts. Uh and there are some + + + align:start position:0% +various sorts. Uh and there are some +different types that I mean there the + + align:start position:0% +different types that I mean there the + + + align:start position:0% +different types that I mean there the +classifications are not hard + + align:start position:0% +classifications are not hard + + + align:start position:0% +classifications are not hard +classifications. Some of them blend from + + align:start position:0% +classifications. Some of them blend from + + + align:start position:0% +classifications. Some of them blend from +one to the other but they tend to come + + align:start position:0% +one to the other but they tend to come + + + align:start position:0% +one to the other but they tend to come +out in a variety of forms. + + align:start position:0% +out in a variety of forms. + + + align:start position:0% +out in a variety of forms. +Um, of course there are the earthly + + align:start position:0% +Um, of course there are the earthly + + + align:start position:0% +Um, of course there are the earthly +paradise, earthly paradise utopias. + + align:start position:0% +paradise, earthly paradise utopias. + + + align:start position:0% +paradise, earthly paradise utopias. +People have written about worlds in + + align:start position:0% +People have written about worlds in + + + align:start position:0% +People have written about worlds in +which uh they + + align:start position:0% +which uh they + + + align:start position:0% +which uh they +imagine uh sort of perfect condition for + + align:start position:0% +imagine uh sort of perfect condition for + + + align:start position:0% +imagine uh sort of perfect condition for +humans. Uh and examples of this would be + + align:start position:0% +humans. Uh and examples of this would be + + + align:start position:0% +humans. Uh and examples of this would be +uh old myths uh and and also in some + + align:start position:0% +uh old myths uh and and also in some + + + align:start position:0% +uh old myths uh and and also in some +sense Genesis the uh the paradise uh of + + align:start position:0% +sense Genesis the uh the paradise uh of + + + align:start position:0% +sense Genesis the uh the paradise uh of +the Bible and other other religious + + align:start position:0% +the Bible and other other religious + + + align:start position:0% +the Bible and other other religious +traditions have sort of paradisel like + + align:start position:0% +traditions have sort of paradisel like + + + align:start position:0% +traditions have sort of paradisel like +conditions where uh people may have + + align:start position:0% +conditions where uh people may have + + + align:start position:0% +conditions where uh people may have +lived before + + align:start position:0% +lived before + + + align:start position:0% +lived before +they they committed + + align:start position:0% +they they committed + + + align:start position:0% +they they committed +some terrible sin and were thrust out of + + align:start position:0% +some terrible sin and were thrust out of + + + align:start position:0% +some terrible sin and were thrust out of +the out of the paradise. So this uh this + + align:start position:0% +the out of the paradise. So this uh this + + + align:start position:0% +the out of the paradise. So this uh this +idea of paradise is is uh very much u + + align:start position:0% +idea of paradise is is uh very much u + + + align:start position:0% +idea of paradise is is uh very much u +here's uh earthly paradise of uh a + + align:start position:0% +here's uh earthly paradise of uh a + + + align:start position:0% +here's uh earthly paradise of uh a +bos famous artist + + align:start position:0% +bos famous artist + + + align:start position:0% +bos famous artist +uh and he's uh this was done in 1510 and + + align:start position:0% +uh and he's uh this was done in 1510 and + + + align:start position:0% +uh and he's uh this was done in 1510 and +you you sort of if you study this you + + align:start position:0% +you you sort of if you study this you + + + align:start position:0% +you you sort of if you study this you +see all forms of pleasure. This is a + + align:start position:0% +see all forms of pleasure. This is a + + + align:start position:0% +see all forms of pleasure. This is a +kind of earthly paradise where + + align:start position:0% +kind of earthly paradise where + + + align:start position:0% +kind of earthly paradise where +everybody's enjoying you know some some + + align:start position:0% +everybody's enjoying you know some some + + + align:start position:0% +everybody's enjoying you know some some +some expression of the + + align:start position:0% +some expression of the + + + align:start position:0% +some expression of the +senses. So oftentimes earthly paradises + + align:start position:0% +senses. So oftentimes earthly paradises + + + align:start position:0% +senses. So oftentimes earthly paradises +have uh uh some of the traits are you + + align:start position:0% +have uh uh some of the traits are you + + + align:start position:0% +have uh uh some of the traits are you +know complete + + align:start position:0% +know complete + + + align:start position:0% +know complete +comfort and and escape from the ills of + + align:start position:0% +comfort and and escape from the ills of + + + align:start position:0% +comfort and and escape from the ills of +the world. It's a very non-malthusian + + align:start position:0% +the world. It's a very non-malthusian + + + align:start position:0% +the world. It's a very non-malthusian +world the the sort of uh type of world + + align:start position:0% +world the the sort of uh type of world + + + align:start position:0% +world the the sort of uh type of world +that might exist. Uh, and of course + + align:start position:0% +that might exist. Uh, and of course + + + align:start position:0% +that might exist. Uh, and of course +we're always interested in I mean there + + align:start position:0% +we're always interested in I mean there + + + align:start position:0% +we're always interested in I mean there +there's something about these uh a world + + align:start position:0% +there's something about these uh a world + + + align:start position:0% +there's something about these uh a world +a paradise a world a paradise that's + + align:start position:0% +a paradise a world a paradise that's + + + align:start position:0% +a paradise a world a paradise that's +attractive and we do our best with our + + align:start position:0% +attractive and we do our best with our + + + align:start position:0% +attractive and we do our best with our +technologies and so forth to create + + align:start position:0% +technologies and so forth to create + + + align:start position:0% +technologies and so forth to create +better surroundings for ourselves. So + + align:start position:0% +better surroundings for ourselves. So + + + align:start position:0% +better surroundings for ourselves. So +this is a kind of a a human impulse to + + align:start position:0% +this is a kind of a a human impulse to + + + align:start position:0% +this is a kind of a a human impulse to +improve the conditions of existence as + + align:start position:0% +improve the conditions of existence as + + + align:start position:0% +improve the conditions of existence as +as Darwin might say conditions of + + align:start position:0% +as Darwin might say conditions of + + + align:start position:0% +as Darwin might say conditions of +existence that's what we all survive in + + align:start position:0% +existence that's what we all survive in + + + align:start position:0% +existence that's what we all survive in +and they're harsh and they're uh for + + align:start position:0% +and they're harsh and they're uh for + + + align:start position:0% +and they're harsh and they're uh for +most organisms + + align:start position:0% +most organisms + + + align:start position:0% +most organisms +unmanageable. Um and so humans have this + + align:start position:0% +unmanageable. Um and so humans have this + + + align:start position:0% +unmanageable. Um and so humans have this +capacity to change their conditions of + + align:start position:0% +capacity to change their conditions of + + + align:start position:0% +capacity to change their conditions of +existence. + + align:start position:0% +existence. + + + align:start position:0% +existence. +That's very much what we're doing here + + align:start position:0% +That's very much what we're doing here + + + align:start position:0% +That's very much what we're doing here +today. It's around freezing outside this + + align:start position:0% +today. It's around freezing outside this + + + align:start position:0% +today. It's around freezing outside this +morning and we're sitting on in here in + + align:start position:0% +morning and we're sitting on in here in + + + align:start position:0% +morning and we're sitting on in here in +this nice warm room and sort of so we + + align:start position:0% +this nice warm room and sort of so we + + + align:start position:0% +this nice warm room and sort of so we +have changed our conditions of existence + + align:start position:0% +have changed our conditions of existence + + + align:start position:0% +have changed our conditions of existence +if you will and we do this on a massive + + align:start position:0% +if you will and we do this on a massive + + + align:start position:0% +if you will and we do this on a massive +scale in in contemporary society. + + align:start position:0% +scale in in contemporary society. + + + align:start position:0% +scale in in contemporary society. +Uh other types of utopic literature + + align:start position:0% +Uh other types of utopic literature + + + align:start position:0% +Uh other types of utopic literature +include sort of + + align:start position:0% +include sort of + + + align:start position:0% +include sort of +political and social + + align:start position:0% +political and social + + + align:start position:0% +political and social +uh worlds that uh have been uh posited + + align:start position:0% +uh worlds that uh have been uh posited + + + align:start position:0% +uh worlds that uh have been uh posited +by thinkers through the + + align:start position:0% +by thinkers through the + + + align:start position:0% +by thinkers through the +ages. Uh Plato's Republic was a kind of + + align:start position:0% +ages. Uh Plato's Republic was a kind of + + + align:start position:0% +ages. Uh Plato's Republic was a kind of +a a world in which he imagined what the + + align:start position:0% +a a world in which he imagined what the + + + align:start position:0% +a a world in which he imagined what the +right and perfect or best + + align:start position:0% +right and perfect or best + + + align:start position:0% +right and perfect or best +kind of political world might be um and + + align:start position:0% +kind of political world might be um and + + + align:start position:0% +kind of political world might be um and +a world of u u that would + + align:start position:0% +a world of u u that would + + + align:start position:0% +a world of u u that would +work in some sense for the greatest + + align:start position:0% +work in some sense for the greatest + + + align:start position:0% +work in some sense for the greatest +benefit of + + align:start position:0% +benefit of + + + align:start position:0% +benefit of +society. Um other people have imagined + + align:start position:0% +society. Um other people have imagined + + + align:start position:0% +society. Um other people have imagined +uh Thomas Moore was a uh uh another + + align:start position:0% +uh Thomas Moore was a uh uh another + + + align:start position:0% +uh Thomas Moore was a uh uh another +thinker who actually wrote one of the + + align:start position:0% +thinker who actually wrote one of the + + + align:start position:0% +thinker who actually wrote one of the +first utopias. He he he titled it + + align:start position:0% +first utopias. He he he titled it + + + align:start position:0% +first utopias. He he he titled it +utopia. What does utopia mean? + + align:start position:0% + + + + align:start position:0% + +Utopia in like the roots or no? No. + + align:start position:0% +Utopia in like the roots or no? No. + + + align:start position:0% +Utopia in like the roots or no? No. +Perfect society. + + align:start position:0% +Perfect society. + + + align:start position:0% +Perfect society. +Well, that's that's what we associate + + align:start position:0% +Well, that's that's what we associate + + + align:start position:0% +Well, that's that's what we associate +with it. But the word itself means + + align:start position:0% +with it. But the word itself means + + + align:start position:0% +with it. But the word itself means +nowhere. + + align:start position:0% +nowhere. + + + align:start position:0% +nowhere. +So it it it's it's an admission that it + + align:start position:0% +So it it it's it's an admission that it + + + align:start position:0% +So it it it's it's an admission that it +doesn't in some sense utopic literature + + align:start position:0% +doesn't in some sense utopic literature + + + align:start position:0% +doesn't in some sense utopic literature +starts with the + + align:start position:0% +starts with the + + + align:start position:0% +starts with the +uh admission + + align:start position:0% +uh admission + + + align:start position:0% +uh admission +that this does not exist. So it's a it's + + align:start position:0% +that this does not exist. So it's a it's + + + align:start position:0% +that this does not exist. So it's a it's +a kind of a complex thought experiment + + align:start position:0% +a kind of a complex thought experiment + + + align:start position:0% +a kind of a complex thought experiment +you might say. How would we organize + + align:start position:0% +you might say. How would we organize + + + align:start position:0% +you might say. How would we organize +ourselves if we did it in the best way + + align:start position:0% +ourselves if we did it in the best way + + + align:start position:0% +ourselves if we did it in the best way +we possibly could? that idealism + + align:start position:0% +we possibly could? that idealism + + + align:start position:0% +we possibly could? that idealism +um can be supported in a variety of ways + + align:start position:0% +um can be supported in a variety of ways + + + align:start position:0% +um can be supported in a variety of ways +and we have other types of utopias or + + align:start position:0% +and we have other types of utopias or + + + align:start position:0% +and we have other types of utopias or +utopic uh works uh that are based on + + align:start position:0% +utopic uh works uh that are based on + + + align:start position:0% +utopic uh works uh that are based on +technology. How how is technology + + align:start position:0% +technology. How how is technology + + + align:start position:0% +technology. How how is technology +utopic? What is it about technology that + + align:start position:0% +utopic? What is it about technology that + + + align:start position:0% +utopic? What is it about technology that +pursues utopian ideals? + + align:start position:0% + + + + align:start position:0% + +Well, I mean we never technology can + + align:start position:0% +Well, I mean we never technology can + + + align:start position:0% +Well, I mean we never technology can +never quite make things perfect, but in + + align:start position:0% +never quite make things perfect, but in + + + align:start position:0% +never quite make things perfect, but in +coming up with like technological + + align:start position:0% +coming up with like technological + + + align:start position:0% +coming up with like technological +advances, our goal is to like increase + + align:start position:0% +advances, our goal is to like increase + + + align:start position:0% +advances, our goal is to like increase +probably standard of living in some way + + align:start position:0% +probably standard of living in some way + + + align:start position:0% +probably standard of living in some way +for somebody. + + align:start position:0% +for somebody. + + + align:start position:0% +for somebody. +So I guess advances in technology some + + align:start position:0% +So I guess advances in technology some + + + align:start position:0% +So I guess advances in technology some +may see as leading us toward a utopic + + align:start position:0% +may see as leading us toward a utopic + + + align:start position:0% +may see as leading us toward a utopic +place but then + + align:start position:0% +place but then + + + align:start position:0% +place but then +also like technological advances are + + align:start position:0% +also like technological advances are + + + align:start position:0% +also like technological advances are +also kind of what are getting us into a + + align:start position:0% +also kind of what are getting us into a + + + align:start position:0% +also kind of what are getting us into a +lot of trouble with like population size + + align:start position:0% +lot of trouble with like population size + + + align:start position:0% +lot of trouble with like population size +and everything. So I feel like it can be + + align:start position:0% +and everything. So I feel like it can be + + + align:start position:0% +and everything. So I feel like it can be +a little bit deceiving. + + align:start position:0% +a little bit deceiving. + + + align:start position:0% +a little bit deceiving. +Well, yeah, there there's a cost to + + align:start position:0% +Well, yeah, there there's a cost to + + + align:start position:0% +Well, yeah, there there's a cost to +things that uh that are developed and + + align:start position:0% +things that uh that are developed and + + + align:start position:0% +things that uh that are developed and +sometimes those costs turned out to have + + align:start position:0% +sometimes those costs turned out to have + + + align:start position:0% +sometimes those costs turned out to have +uh + + align:start position:0% +uh + + + align:start position:0% +uh +secondary elements that are, you know, + + align:start position:0% +secondary elements that are, you know, + + + align:start position:0% +secondary elements that are, you know, +rather overwhelming, but yes, there's + + align:start position:0% +rather overwhelming, but yes, there's + + + align:start position:0% +rather overwhelming, but yes, there's +that. Jake, did you have something to + + align:start position:0% +that. Jake, did you have something to + + + align:start position:0% +that. Jake, did you have something to +add to that? say that technology uh well + + align:start position:0% +add to that? say that technology uh well + + + align:start position:0% +add to that? say that technology uh well +like you said with uh the conditions of + + align:start position:0% +like you said with uh the conditions of + + + align:start position:0% +like you said with uh the conditions of +existence the I mean it can't bring us + + align:start position:0% +existence the I mean it can't bring us + + + align:start position:0% +existence the I mean it can't bring us +at least as far as we are can't bring us + + align:start position:0% +at least as far as we are can't bring us + + + align:start position:0% +at least as far as we are can't bring us +all the way to utopia but it I mean it + + align:start position:0% +all the way to utopia but it I mean it + + + align:start position:0% +all the way to utopia but it I mean it +moves us in the right direction it takes + + align:start position:0% +moves us in the right direction it takes + + + align:start position:0% +moves us in the right direction it takes +thing takes bad things and makes them + + align:start position:0% +thing takes bad things and makes them + + + align:start position:0% +thing takes bad things and makes them +either a + + align:start position:0% + + + + align:start position:0% + +nonfactor good + + align:start position:0% +nonfactor good + + + align:start position:0% +nonfactor good +things and as you say we're we're trying + + align:start position:0% +things and as you say we're we're trying + + + align:start position:0% +things and as you say we're we're trying +to improve the human + + align:start position:0% +to improve the human + + + align:start position:0% +to improve the human +tradition. Utopias have also been part + + align:start position:0% +tradition. Utopias have also been part + + + align:start position:0% +tradition. Utopias have also been part +of the satirical tradition. Uh Butler's + + align:start position:0% +of the satirical tradition. Uh Butler's + + + align:start position:0% +of the satirical tradition. Uh Butler's +uh one of his uh one of the one of the + + align:start position:0% +uh one of his uh one of the one of the + + + align:start position:0% +uh one of his uh one of the one of the +writers who he modeled his work on or + + align:start position:0% +writers who he modeled his work on or + + + align:start position:0% +writers who he modeled his work on or +who he not modeled so much but he was + + align:start position:0% +who he not modeled so much but he was + + + align:start position:0% +who he not modeled so much but he was +thinking of was uh Jonathan Swift who + + align:start position:0% +thinking of was uh Jonathan Swift who + + + align:start position:0% +thinking of was uh Jonathan Swift who +wrote Goliver's + + align:start position:0% +wrote Goliver's + + + align:start position:0% +wrote Goliver's +Travels and uh anybody here read + + align:start position:0% +Travels and uh anybody here read + + + align:start position:0% +Travels and uh anybody here read +Goliver's Travels see the work? I don't + + align:start position:0% +Goliver's Travels see the work? I don't + + + align:start position:0% +Goliver's Travels see the work? I don't +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Yeah. Yeah. Well, after that, well, + + align:start position:0% +Yeah. Yeah. Well, after that, well, + + + align:start position:0% +Yeah. Yeah. Well, after that, well, +Goliver's Travels is uh, you know, it's + + align:start position:0% +Goliver's Travels is uh, you know, it's + + + align:start position:0% +Goliver's Travels is uh, you know, it's +a it's a it's sort of just a a fantasy, + + align:start position:0% +a it's a it's sort of just a a fantasy, + + + align:start position:0% +a it's a it's sort of just a a fantasy, +a + + align:start position:0% +a + + + align:start position:0% +a +fiction that is u written by Jonathan + + align:start position:0% +fiction that is u written by Jonathan + + + align:start position:0% +fiction that is u written by Jonathan +Swift in the early 18th century of this + + align:start position:0% +Swift in the early 18th century of this + + + align:start position:0% +Swift in the early 18th century of this +voyager who goes out and he voyages to + + align:start position:0% +voyager who goes out and he voyages to + + + align:start position:0% +voyager who goes out and he voyages to +all these different lands and in each + + align:start position:0% +all these different lands and in each + + + align:start position:0% +all these different lands and in each +land he discovers, you know, different + + align:start position:0% +land he discovers, you know, different + + + align:start position:0% +land he discovers, you know, different +types of people who he interacts with + + align:start position:0% +types of people who he interacts with + + + align:start position:0% +types of people who he interacts with +and through these interactions + + align:start position:0% +and through these interactions + + + align:start position:0% +and through these interactions +uh Swift is able + + align:start position:0% +uh Swift is able + + + align:start position:0% +uh Swift is able +to write uh satirical + + align:start position:0% +to write uh satirical + + + align:start position:0% +to write uh satirical +portraits of + + align:start position:0% +portraits of + + + align:start position:0% +portraits of +contemporary British + + align:start position:0% +contemporary British + + + align:start position:0% +contemporary British +society. He uses this travel to kind of + + align:start position:0% +society. He uses this travel to kind of + + + align:start position:0% +society. He uses this travel to kind of +fantasize in ways that are critical of + + align:start position:0% +fantasize in ways that are critical of + + + align:start position:0% +fantasize in ways that are critical of +society. So that's so that's that's a + + align:start position:0% +society. So that's so that's that's a + + + align:start position:0% +society. So that's so that's that's a +direct model for Butler's work. Okay. So + + align:start position:0% +direct model for Butler's work. Okay. So + + + align:start position:0% +direct model for Butler's work. Okay. So +back to Butler. + + align:start position:0% +back to Butler. + + + align:start position:0% +back to Butler. +Um, so yes, utopia is a is a is a + + align:start position:0% +Um, so yes, utopia is a is a is a + + + align:start position:0% +Um, so yes, utopia is a is a is a +nowhere. It's a generally highly + + align:start position:0% +nowhere. It's a generally highly + + + align:start position:0% +nowhere. It's a generally highly +idealized uh human- centered tradition. + + align:start position:0% +idealized uh human- centered tradition. + + + align:start position:0% +idealized uh human- centered tradition. +um and + + align:start position:0% +um and + + + align:start position:0% +um and +oftentimes is either + + align:start position:0% +oftentimes is either + + + align:start position:0% +oftentimes is either +uh offering or seeking a sort of uh + + align:start position:0% +uh offering or seeking a sort of uh + + + align:start position:0% +uh offering or seeking a sort of uh +perfect + + align:start position:0% +perfect + + + align:start position:0% +perfect +adaptation between the human and his or + + align:start position:0% +adaptation between the human and his or + + + align:start position:0% +adaptation between the human and his or +her environment. So that's that's sort + + align:start position:0% +her environment. So that's that's sort + + + align:start position:0% +her environment. So that's that's sort +of the the goal and this is secured in a + + align:start position:0% +of the the goal and this is secured in a + + + align:start position:0% +of the the goal and this is secured in a +variety of ways. can be secured uh you + + align:start position:0% +variety of ways. can be secured uh you + + + align:start position:0% +variety of ways. can be secured uh you +know sometimes politically through + + align:start position:0% +know sometimes politically through + + + align:start position:0% +know sometimes politically through +organization technologically through + + align:start position:0% +organization technologically through + + + align:start position:0% +organization technologically through +technological development uh and + + align:start position:0% +technological development uh and + + + align:start position:0% +technological development uh and +sometimes uh through uh religious + + align:start position:0% +sometimes uh through uh religious + + + align:start position:0% +sometimes uh through uh religious +religions I mean religions are + + align:start position:0% +religions I mean religions are + + + align:start position:0% +religions I mean religions are +definitely + + align:start position:0% +definitely + + + align:start position:0% +definitely +uh ways in which people try to adapt to + + align:start position:0% +uh ways in which people try to adapt to + + + align:start position:0% +uh ways in which people try to adapt to +their circumstances + + align:start position:0% +their circumstances + + + align:start position:0% +their circumstances +u and you know they're they're they're + + align:start position:0% +u and you know they're they're they're + + + align:start position:0% +u and you know they're they're they're +driven by ideas every every much as uh + + align:start position:0% +driven by ideas every every much as uh + + + align:start position:0% +driven by ideas every every much as uh +some of these others other utopic + + align:start position:0% +some of these others other utopic + + + align:start position:0% +some of these others other utopic +traditions are. Uh Butler went to New + + align:start position:0% +traditions are. Uh Butler went to New + + + align:start position:0% +traditions are. Uh Butler went to New +Zealand in the + + align:start position:0% +Zealand in the + + + align:start position:0% +Zealand in the +1860s as a young man. He uh he was um a + + align:start position:0% +1860s as a young man. He uh he was um a + + + align:start position:0% +1860s as a young man. He uh he was um a +graduate of Cambridge University. + + align:start position:0% +graduate of Cambridge University. + + + align:start position:0% +graduate of Cambridge University. +uh he uh was originally following a + + align:start position:0% +uh he uh was originally following a + + + align:start position:0% +uh he uh was originally following a +course of + + align:start position:0% +course of + + + align:start position:0% +course of +math study of + + align:start position:0% +math study of + + + align:start position:0% +math study of +mathematics, but at the end it just he + + align:start position:0% +mathematics, but at the end it just he + + + align:start position:0% +mathematics, but at the end it just he +couldn't quite keep it together. And so + + align:start position:0% +couldn't quite keep it together. And so + + + align:start position:0% +couldn't quite keep it together. And so +he ended up + + align:start position:0% +he ended up + + + align:start position:0% +he ended up +graduating in sort of religious uh more + + align:start position:0% +graduating in sort of religious uh more + + + align:start position:0% +graduating in sort of religious uh more +of a religious studies studies in in the + + align:start position:0% +of a religious studies studies in in the + + + align:start position:0% +of a religious studies studies in in the +Bible and things of that sort. um sort + + align:start position:0% +Bible and things of that sort. um sort + + + align:start position:0% +Bible and things of that sort. um sort +of a + + align:start position:0% +of a + + + align:start position:0% +of a +pre-clerical educational prep. And at + + align:start position:0% +pre-clerical educational prep. And at + + + align:start position:0% +pre-clerical educational prep. And at +one time he was considering uh becoming + + align:start position:0% +one time he was considering uh becoming + + + align:start position:0% +one time he was considering uh becoming +a cleric + + align:start position:0% +a cleric + + + align:start position:0% +a cleric +uh uh some sort of u uh religious uh + + align:start position:0% +uh uh some sort of u uh religious uh + + + align:start position:0% +uh uh some sort of u uh religious uh +uh leader. + + align:start position:0% +uh leader. + + + align:start position:0% +uh leader. +So at the end of his studies, he decided + + align:start position:0% +So at the end of his studies, he decided + + + align:start position:0% +So at the end of his studies, he decided +this was not something he could really + + align:start position:0% +this was not something he could really + + + align:start position:0% +this was not something he could really +do. who he just didn't want to be didn't + + align:start position:0% +do. who he just didn't want to be didn't + + + align:start position:0% +do. who he just didn't want to be didn't +want to become part of uh he he didn't + + align:start position:0% +want to become part of uh he he didn't + + + align:start position:0% +want to become part of uh he he didn't +want to become a cleric and go out and + + align:start position:0% +want to become a cleric and go out and + + + align:start position:0% +want to become a cleric and go out and +have a you know a group of people who he + + align:start position:0% +have a you know a group of people who he + + + align:start position:0% +have a you know a group of people who he +led and so forth. He he just felt that + + align:start position:0% +led and so forth. He he just felt that + + + align:start position:0% +led and so forth. He he just felt that +this was not an appropriate + + align:start position:0% +this was not an appropriate + + + align:start position:0% +this was not an appropriate +uh form of uh employment and life work + + align:start position:0% +uh form of uh employment and life work + + + align:start position:0% +uh form of uh employment and life work +for him. But his father disagreed with + + align:start position:0% +for him. But his father disagreed with + + + align:start position:0% +for him. But his father disagreed with +him very strongly because his father was + + align:start position:0% +him very strongly because his father was + + + align:start position:0% +him very strongly because his father was +was a cleric and uh they had monumental + + align:start position:0% +was a cleric and uh they had monumental + + + align:start position:0% +was a cleric and uh they had monumental +fights and so they finally settled it + + align:start position:0% +fights and so they finally settled it + + + align:start position:0% +fights and so they finally settled it +that Butler would immigrate to New + + align:start position:0% +that Butler would immigrate to New + + + align:start position:0% +that Butler would immigrate to New +Zealand and so off he went. So he he uh + + align:start position:0% +Zealand and so off he went. So he he uh + + + align:start position:0% +Zealand and so off he went. So he he uh +he went to New Zealand and he was there + + align:start position:0% +he went to New Zealand and he was there + + + align:start position:0% +he went to New Zealand and he was there +in uh uh + + align:start position:0% +in uh uh + + + align:start position:0% +in uh uh +1859 when Darwin's origin came out and + + align:start position:0% +1859 when Darwin's origin came out and + + + align:start position:0% +1859 when Darwin's origin came out and +he was fascinated by the + + align:start position:0% +he was fascinated by the + + + align:start position:0% +he was fascinated by the +book because uh he was a sheep he owned + + align:start position:0% +book because uh he was a sheep he owned + + + align:start position:0% +book because uh he was a sheep he owned +a sheep station there and he did a lot + + align:start position:0% +a sheep station there and he did a lot + + + align:start position:0% +a sheep station there and he did a lot +of + + align:start position:0% +of + + + align:start position:0% +of +breeding. So when he got Darwin's origin + + align:start position:0% +breeding. So when he got Darwin's origin + + + align:start position:0% +breeding. So when he got Darwin's origin +uh variation under domestication and all + + align:start position:0% +uh variation under domestication and all + + + align:start position:0% +uh variation under domestication and all +this uh language uh it made a whole lot + + align:start position:0% +this uh language uh it made a whole lot + + + align:start position:0% +this uh language uh it made a whole lot +of sense to him and of course he was uh + + align:start position:0% +of sense to him and of course he was uh + + + align:start position:0% +of sense to him and of course he was uh +a graduate of Darwin's university too. + + align:start position:0% +a graduate of Darwin's university too. + + + align:start position:0% +a graduate of Darwin's university too. +So he had read uh many of the works that + + align:start position:0% +So he had read uh many of the works that + + + align:start position:0% +So he had read uh many of the works that +Darwin had read including + + align:start position:0% +Darwin had read including + + + align:start position:0% +Darwin had read including +Paley and Paley turns up back in in this + + align:start position:0% +Paley and Paley turns up back in in this + + + align:start position:0% +Paley and Paley turns up back in in this +book and in fact Paley is one of the key + + align:start position:0% +book and in fact Paley is one of the key + + + align:start position:0% +book and in fact Paley is one of the key +uh one of the key objects of the + + align:start position:0% +uh one of the key objects of the + + + align:start position:0% +uh one of the key objects of the +satire and you know in a in an + + align:start position:0% +satire and you know in a in an + + + align:start position:0% +satire and you know in a in an +interesting not not in a a nasty way but + + align:start position:0% +interesting not not in a a nasty way but + + + align:start position:0% +interesting not not in a a nasty way but +in a fascinating intellectual way. + + align:start position:0% +in a fascinating intellectual way. + + + align:start position:0% +in a fascinating intellectual way. +Okay. So, + + align:start position:0% +Okay. So, + + + align:start position:0% +Okay. So, +uh this is uh uh this is this is the + + align:start position:0% +uh this is uh uh this is this is the + + + align:start position:0% +uh this is uh uh this is this is the +setting for this + + align:start position:0% +setting for this + + + align:start position:0% +setting for this +work. Okay. + + align:start position:0% +work. Okay. + + + align:start position:0% +work. Okay. +So, excuse me. Um + + align:start position:0% + + + + align:start position:0% + +uh what's what's going on in this book? + + align:start position:0% +uh what's what's going on in this book? + + + align:start position:0% +uh what's what's going on in this book? +What are some of the things that uh you + + align:start position:0% +What are some of the things that uh you + + + align:start position:0% +What are some of the things that uh you +noted here? And uh what are some of the + + align:start position:0% +noted here? And uh what are some of the + + + align:start position:0% +noted here? And uh what are some of the +big ideas here that Butler? It's it's a + + align:start position:0% +big ideas here that Butler? It's it's a + + + align:start position:0% +big ideas here that Butler? It's it's a +tale. Yes, it's a tale of a guy who goes + + align:start position:0% +tale. Yes, it's a tale of a guy who goes + + + align:start position:0% +tale. Yes, it's a tale of a guy who goes +over the hill. Actually, this + + align:start position:0% +over the hill. Actually, this + + + align:start position:0% +over the hill. Actually, this +hill was uh if you go way back up way + + align:start position:0% +hill was uh if you go way back up way + + + align:start position:0% +hill was uh if you go way back up way +back up in this area up here, someplace + + align:start position:0% +back up in this area up here, someplace + + + align:start position:0% +back up in this area up here, someplace +up here is actually where he he actually + + align:start position:0% +up here is actually where he he actually + + + align:start position:0% +up here is actually where he he actually +went up there. So the uh the start of + + align:start position:0% +went up there. So the uh the start of + + + align:start position:0% +went up there. So the uh the start of +the book actually is quite accurate with + + align:start position:0% +the book actually is quite accurate with + + + align:start position:0% +the book actually is quite accurate with +uh he was a pretty good uh + + align:start position:0% +uh he was a pretty good uh + + + align:start position:0% +uh he was a pretty good uh +hiking he was a budding mountaineer not + + align:start position:0% +hiking he was a budding mountaineer not + + + align:start position:0% +hiking he was a budding mountaineer not +quite there but he was pretty pretty + + align:start position:0% +quite there but he was pretty pretty + + + align:start position:0% +quite there but he was pretty pretty +good on his feet and he + + align:start position:0% +good on his feet and he + + + align:start position:0% +good on his feet and he +uh so this is the the mountain range + + align:start position:0% +uh so this is the the mountain range + + + align:start position:0% +uh so this is the the mountain range +that uh the + + align:start position:0% +that uh the + + + align:start position:0% +that uh the +narrator in Arowan goes over and he goes + + align:start position:0% +narrator in Arowan goes over and he goes + + + align:start position:0% +narrator in Arowan goes over and he goes +over this mountain range And as uh as as + + align:start position:0% +over this mountain range And as uh as as + + + align:start position:0% +over this mountain range And as uh as as +Candid as uh Candid did in in Vololier's + + align:start position:0% +Candid as uh Candid did in in Vololier's + + + align:start position:0% +Candid as uh Candid did in in Vololier's +Candid uh over the mountain range into + + align:start position:0% +Candid uh over the mountain range into + + + align:start position:0% +Candid uh over the mountain range into +this world, this kind of new + + align:start position:0% +this world, this kind of new + + + align:start position:0% +this world, this kind of new +world and it's a kind of a utopia. So + + align:start position:0% +world and it's a kind of a utopia. So + + + align:start position:0% +world and it's a kind of a utopia. So +it's it's one of So it's going to be a + + align:start position:0% +it's it's one of So it's going to be a + + + align:start position:0% +it's it's one of So it's going to be a +thought experiment. That's what it is. + + align:start position:0% +thought experiment. That's what it is. + + + align:start position:0% +thought experiment. That's what it is. +It's a whole bunch of encounters and he + + align:start position:0% +It's a whole bunch of encounters and he + + + align:start position:0% +It's a whole bunch of encounters and he +develops a society. So what are some of + + align:start position:0% +develops a society. So what are some of + + + align:start position:0% +develops a society. So what are some of +the characteristics of this society that + + align:start position:0% +the characteristics of this society that + + + align:start position:0% +the characteristics of this society that +he discovers? + + align:start position:0% +he discovers? + + + align:start position:0% +he discovers? +Claire, well, anything to do with + + align:start position:0% +Claire, well, anything to do with + + + align:start position:0% +Claire, well, anything to do with +illness is almost like a crime. Um, + + align:start position:0% +illness is almost like a crime. Um, + + + align:start position:0% +illness is almost like a crime. Um, +people are imprisoned if they're seen as + + align:start position:0% +people are imprisoned if they're seen as + + + align:start position:0% +people are imprisoned if they're seen as +being sickly at all, whereas like things + + align:start position:0% +being sickly at all, whereas like things + + + align:start position:0% +being sickly at all, whereas like things +that people would be imprisoned for in + + align:start position:0% +that people would be imprisoned for in + + + align:start position:0% +that people would be imprisoned for in +our world aren't punished really at all. + + align:start position:0% +our world aren't punished really at all. + + + align:start position:0% +our world aren't punished really at all. +And it seems like beauty and aesthetic + + align:start position:0% +And it seems like beauty and aesthetic + + + align:start position:0% +And it seems like beauty and aesthetic +things are very selective for. Okay. + + align:start position:0% +things are very selective for. Okay. + + + align:start position:0% +things are very selective for. Okay. +Yes. So he says here, here's a a short + + align:start position:0% +Yes. So he says here, here's a a short + + + align:start position:0% +Yes. So he says here, here's a a short +or here's a quote. Lastly, I should say + + align:start position:0% +or here's a quote. Lastly, I should say + + + align:start position:0% +or here's a quote. Lastly, I should say +that the people were of a physical + + align:start position:0% +that the people were of a physical + + + align:start position:0% +that the people were of a physical +beauty which was simply + + align:start position:0% +beauty which was simply + + + align:start position:0% +beauty which was simply +amazing. The women were vigorous and had + + align:start position:0% +amazing. The women were vigorous and had + + + align:start position:0% +amazing. The women were vigorous and had +a most majestic gate, their heads being + + align:start position:0% +a most majestic gate, their heads being + + + align:start position:0% +a most majestic gate, their heads being +set on upon their shoulders with a grace + + align:start position:0% +set on upon their shoulders with a grace + + + align:start position:0% +set on upon their shoulders with a grace +beyond all power of expression. + + align:start position:0% +beyond all power of expression. + + + align:start position:0% +beyond all power of expression. +The men were as handsome as the women + + align:start position:0% +The men were as handsome as the women + + + align:start position:0% +The men were as handsome as the women +were beautiful. I felt simply abashed in + + align:start position:0% +were beautiful. I felt simply abashed in + + + align:start position:0% +were beautiful. I felt simply abashed in +the presence of such a splendid type. A + + align:start position:0% +the presence of such a splendid type. A + + + align:start position:0% +the presence of such a splendid type. A +compound that is all that is best in + + align:start position:0% +compound that is all that is best in + + + align:start position:0% +compound that is all that is best in +Egyptian, Greek, and Italian, so on and + + align:start position:0% +Egyptian, Greek, and Italian, so on and + + + align:start position:0% +Egyptian, Greek, and Italian, so on and +so forth. What What's he encountering + + align:start position:0% +so forth. What What's he encountering + + + align:start position:0% +so forth. What What's he encountering +here? + + align:start position:0% + + + + align:start position:0% + +Beautiful people, Jake. + + align:start position:0% +Beautiful people, Jake. + + + align:start position:0% +Beautiful people, Jake. +Well, beautiful people, basically. And + + align:start position:0% +Well, beautiful people, basically. And + + + align:start position:0% +Well, beautiful people, basically. And +And why are they beautiful? Uh how did + + align:start position:0% +And why are they beautiful? Uh how did + + + align:start position:0% +And why are they beautiful? Uh how did +they be how did they come to be so + + align:start position:0% +they be how did they come to be so + + + align:start position:0% +they be how did they come to be so +beautiful? They selected themselves for + + align:start position:0% +beautiful? They selected themselves for + + + align:start position:0% +beautiful? They selected themselves for +basically they took people who are like + + align:start position:0% +basically they took people who are like + + + align:start position:0% +basically they took people who are like +really sickly and stuff and sent them to + + align:start position:0% +really sickly and stuff and sent them to + + + align:start position:0% +really sickly and stuff and sent them to +prison basically. Okay. They got in + + align:start position:0% +prison basically. Okay. They got in + + + align:start position:0% +prison basically. Okay. They got in +trouble. All right. So you you get into + + align:start position:0% +trouble. All right. So you you get into + + + align:start position:0% +trouble. All right. So you you get into +you get into trouble in this society. If + + align:start position:0% +you get into trouble in this society. If + + + align:start position:0% +you get into trouble in this society. If +what are some of the reasons for getting + + align:start position:0% +what are some of the reasons for getting + + + align:start position:0% +what are some of the reasons for getting +how can you get into trouble + + align:start position:0% +how can you get into trouble + + + align:start position:0% +how can you get into trouble +Chris? I think it was + + align:start position:0% + + + + align:start position:0% + +for example. + + align:start position:0% +for example. + + + align:start position:0% +for example. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Probably anything mechanical, right? Or + + align:start position:0% +Probably anything mechanical, right? Or + + + align:start position:0% +Probably anything mechanical, right? Or +any sort of Oh, yeah. If if you have if + + align:start position:0% +any sort of Oh, yeah. If if you have if + + + align:start position:0% +any sort of Oh, yeah. If if you have if +you have a a watch or anything + + align:start position:0% +you have a a watch or anything + + + align:start position:0% +you have a a watch or anything +mechanical, watch out. You're going to + + align:start position:0% +mechanical, watch out. You're going to + + + align:start position:0% +mechanical, watch out. You're going to +get We'll We'll come back to that. + + align:start position:0% +get We'll We'll come back to that. + + + align:start position:0% +get We'll We'll come back to that. +That's that's a big that's a big + + align:start position:0% +That's that's a big that's a big + + + align:start position:0% +That's that's a big that's a big +uh air or uh + + align:start position:0% +uh air or uh + + + align:start position:0% +uh air or uh +crime. It's it's a type of crime. + + align:start position:0% +crime. It's it's a type of crime. + + + align:start position:0% +crime. It's it's a type of crime. +Yeah. One that I didn't really + + align:start position:0% +Yeah. One that I didn't really + + + align:start position:0% +Yeah. One that I didn't really +understand was that you weren't + + align:start position:0% +understand was that you weren't + + + align:start position:0% +understand was that you weren't +imprisoned if you committed like theft. + + align:start position:0% +imprisoned if you committed like theft. + + + align:start position:0% +imprisoned if you committed like theft. +I didn't really understand that. Yeah. + + align:start position:0% +I didn't really understand that. Yeah. + + + align:start position:0% +I didn't really understand that. Yeah. +These people have the really bizarre + + align:start position:0% +These people have the really bizarre + + + align:start position:0% +These people have the really bizarre +opinion that if you embezzle or you + + align:start position:0% +opinion that if you embezzle or you + + + align:start position:0% +opinion that if you embezzle or you +steal, you are + + align:start position:0% + + + + align:start position:0% + +what? They don't treat it as a crime, do + + align:start position:0% +what? They don't treat it as a crime, do + + + align:start position:0% +what? They don't treat it as a crime, do +they? They treat it as a illness. You + + align:start position:0% +they? They treat it as a illness. You + + + align:start position:0% +they? They treat it as a illness. You +are ill. you should be you should be you + + align:start position:0% +are ill. you should be you should be you + + + align:start position:0% +are ill. you should be you should be you +know you need to get help from your + + align:start position:0% +know you need to get help from your + + + align:start position:0% +know you need to get help from your +local straightener and you + + align:start position:0% +local straightener and you + + + align:start position:0% +local straightener and you +know and yet if you are if you have + + align:start position:0% +know and yet if you are if you have + + + align:start position:0% +know and yet if you are if you have +pulmonary + + align:start position:0% +pulmonary + + + align:start position:0% +pulmonary +consumption i.e. TB, + + align:start position:0% +consumption i.e. TB, + + + align:start position:0% +consumption i.e. TB, +tuberculosis. How do they treat that? + + align:start position:0% + + + + align:start position:0% + + you up. + + align:start position:0% + you up. + + + align:start position:0% + you up. +Okay. + + align:start position:0% + + + + align:start position:0% + +Is allowed to persist in their + + align:start position:0% +Is allowed to persist in their + + + align:start position:0% +Is allowed to persist in their +Charles, what do you think of this this + + align:start position:0% +Charles, what do you think of this this + + + align:start position:0% +Charles, what do you think of this this +arrangement? I think it's like it's kind + + align:start position:0% +arrangement? I think it's like it's kind + + + align:start position:0% +arrangement? I think it's like it's kind +of a reverse. It's like a he's trying to + + align:start position:0% +of a reverse. It's like a he's trying to + + + align:start position:0% +of a reverse. It's like a he's trying to +reverse just the kind of the values and + + align:start position:0% +reverse just the kind of the values and + + + align:start position:0% +reverse just the kind of the values and +the underlying fabric of society between + + align:start position:0% +the underlying fabric of society between + + + align:start position:0% +the underlying fabric of society between +society he portrays and our society and + + align:start position:0% +society he portrays and our society and + + + align:start position:0% +society he portrays and our society and +it's like it's just like there's like a + + align:start position:0% +it's like it's just like there's like a + + + align:start position:0% +it's like it's just like there's like a +humorous aspect to it that kind of it's + + align:start position:0% +humorous aspect to it that kind of it's + + + align:start position:0% +humorous aspect to it that kind of it's +like in it's a little bit satirical just + + align:start position:0% +like in it's a little bit satirical just + + + align:start position:0% +like in it's a little bit satirical just +there's like a little bit a lot + + align:start position:0% +there's like a little bit a lot + + + align:start position:0% +there's like a little bit a lot +obviously that's like that's subjective + + align:start position:0% +obviously that's like that's subjective + + + align:start position:0% +obviously that's like that's subjective +but I think there's like an element + + align:start position:0% +but I think there's like an element + + + align:start position:0% +but I think there's like an element +that really just makes you think about + + align:start position:0% +that really just makes you think about + + + align:start position:0% +that really just makes you think about +why. Okay, that's Yeah, it uh it + + align:start position:0% +why. Okay, that's Yeah, it uh it + + + align:start position:0% +why. Okay, that's Yeah, it uh it +occurred to me that while this isn't a + + align:start position:0% +occurred to me that while this isn't a + + + align:start position:0% +occurred to me that while this isn't a +perfect uh analysis that at least to + + align:start position:0% +perfect uh analysis that at least to + + + align:start position:0% +perfect uh analysis that at least to +some extent it seems like the selection + + align:start position:0% +some extent it seems like the selection + + + align:start position:0% +some extent it seems like the selection +forces in Arowan + + align:start position:0% +forces in Arowan + + + align:start position:0% +forces in Arowan +are switched in uh from the ones we have + + align:start position:0% +are switched in uh from the ones we have + + + align:start position:0% +are switched in uh from the ones we have +where the natural selection forces in + + align:start position:0% +where the natural selection forces in + + + align:start position:0% +where the natural selection forces in +our world are the ones that the people + + align:start position:0% +our world are the ones that the people + + + align:start position:0% +our world are the ones that the people +put pressure on there like the sickness + + align:start position:0% +put pressure on there like the sickness + + + align:start position:0% +put pressure on there like the sickness +this and that sensing and the one that + + align:start position:0% +this and that sensing and the one that + + + align:start position:0% +this and that sensing and the one that +people put on here are more of the + + align:start position:0% +people put on here are more of the + + + align:start position:0% +people put on here are more of the +natural. Okay, now you're getting at + + align:start position:0% +natural. Okay, now you're getting at + + + align:start position:0% +natural. Okay, now you're getting at +something. Yes, there is there's + + align:start position:0% +something. Yes, there is there's + + + align:start position:0% +something. Yes, there is there's +something going on here with this + + align:start position:0% +something going on here with this + + + align:start position:0% +something going on here with this +selection and this whole phenomenon and + + align:start position:0% +selection and this whole phenomenon and + + + align:start position:0% +selection and this whole phenomenon and +think + + align:start position:0% +think + + + align:start position:0% +think +Darwin, you know, Darwin's world in the + + align:start position:0% +Darwin, you know, Darwin's world in the + + + align:start position:0% +Darwin, you know, Darwin's world in the +origin, humans are outside. How how does + + align:start position:0% +origin, humans are outside. How how does + + + align:start position:0% +origin, humans are outside. How how does +Darwin's world work? Does it work like + + align:start position:0% +Darwin's world work? Does it work like + + + align:start position:0% +Darwin's world work? Does it work like +our social world or does it work like + + align:start position:0% +our social world or does it work like + + + align:start position:0% +our social world or does it work like +this world that Butler's painting for + + align:start position:0% +this world that Butler's painting for + + + align:start position:0% +this world that Butler's painting for +us? In some sense, a thought experiment + + align:start position:0% +us? In some sense, a thought experiment + + + align:start position:0% +us? In some sense, a thought experiment +is this. What what would a society look + + align:start position:0% +is this. What what would a society look + + + align:start position:0% +is this. What what would a society look +like if it behaved according to + + align:start position:0% +like if it behaved according to + + + align:start position:0% +like if it behaved according to +Darwinian principles and strengthen + + align:start position:0% +Darwinian principles and strengthen + + + align:start position:0% +Darwinian principles and strengthen +those principles? + + align:start position:0% + + + + align:start position:0% + +Is this making any sense, David? + + align:start position:0% +Is this making any sense, David? + + + align:start position:0% +Is this making any sense, David? +Well, it's it's sort of a difficult + + align:start position:0% +Well, it's it's sort of a difficult + + + align:start position:0% +Well, it's it's sort of a difficult +question to answer just because + + align:start position:0% +question to answer just because + + + align:start position:0% +question to answer just because +Darwinian principles say um + + align:start position:0% +Darwinian principles say um + + + align:start position:0% +Darwinian principles say um +people act based for their survival and + + align:start position:0% +people act based for their survival and + + + align:start position:0% +people act based for their survival and +for reproduction based on their traits. + + align:start position:0% +for reproduction based on their traits. + + + align:start position:0% +for reproduction based on their traits. +Um but part of Darwinian Darwin's theory + + align:start position:0% +Um but part of Darwinian Darwin's theory + + + align:start position:0% +Um but part of Darwinian Darwin's theory +is sort of similar to Smith's where + + align:start position:0% +is sort of similar to Smith's where + + + align:start position:0% +is sort of similar to Smith's where +Smith says people act on their own + + align:start position:0% +Smith says people act on their own + + + align:start position:0% +Smith says people act on their own +behavior but that's best for society. Um + + align:start position:0% +behavior but that's best for society. Um + + + align:start position:0% +behavior but that's best for society. Um +if everyone acted + + align:start position:0% +if everyone acted + + + align:start position:0% +if everyone acted +solely like Darwin like Darwin's um + + align:start position:0% +solely like Darwin like Darwin's um + + + align:start position:0% +solely like Darwin like Darwin's um +evolutionary pressures I don't think + + align:start position:0% +evolutionary pressures I don't think + + + align:start position:0% +evolutionary pressures I don't think +we'd be able to have the society we had + + align:start position:0% +we'd be able to have the society we had + + + align:start position:0% +we'd be able to have the society we had +right now. Um + + align:start position:0% +right now. Um + + + align:start position:0% +right now. Um +that's a very big that's a very Yes. And + + align:start position:0% +that's a very big that's a very Yes. And + + + align:start position:0% +that's a very big that's a very Yes. And +and this is this + + align:start position:0% +and this is this + + + align:start position:0% +and this is this +is when you read this and you get into + + align:start position:0% +is when you read this and you get into + + + align:start position:0% +is when you read this and you get into +it, you realize they're punishing + + align:start position:0% +it, you realize they're punishing + + + align:start position:0% +it, you realize they're punishing +illness. What happens to those analopee + + align:start position:0% +illness. What happens to those analopee + + + align:start position:0% +illness. What happens to those analopee +out in the plains who are ill? + + align:start position:0% + + + + align:start position:0% + +They tend to be the ones that get a a + + align:start position:0% +They tend to be the ones that get a a + + + align:start position:0% +They tend to be the ones that get a a +little slower and get picked off. + + align:start position:0% +little slower and get picked off. + + + align:start position:0% +little slower and get picked off. +Uh what about the little fish or + + align:start position:0% +Uh what about the little fish or + + + align:start position:0% +Uh what about the little fish or +whatever that is good at stealing you + + align:start position:0% +whatever that is good at stealing you + + + align:start position:0% +whatever that is good at stealing you +know the rocks from or whatever uh from + + align:start position:0% +know the rocks from or whatever uh from + + + align:start position:0% +know the rocks from or whatever uh from +its neighbor + + align:start position:0% +its neighbor + + + align:start position:0% +its neighbor +it like it will tend to live over its + + align:start position:0% +it like it will tend to live over its + + + align:start position:0% +it like it will tend to live over its +neighbor. Yeah. Theft does not get + + align:start position:0% +neighbor. Yeah. Theft does not get + + + align:start position:0% +neighbor. Yeah. Theft does not get +punished in nature. + + align:start position:0% +punished in nature. + + + align:start position:0% +punished in nature. +I mean, theft can be, you know, if if if + + align:start position:0% +I mean, theft can be, you know, if if if + + + align:start position:0% +I mean, theft can be, you know, if if if +you know how to if you're if you're a + + align:start position:0% +you know how to if you're if you're a + + + align:start position:0% +you know how to if you're if you're a +cuckoo and you can lay your eggs in the + + align:start position:0% +cuckoo and you can lay your eggs in the + + + align:start position:0% +cuckoo and you can lay your eggs in the +bird's nest and have somebody else uh + + align:start position:0% +bird's nest and have somebody else uh + + + align:start position:0% +bird's nest and have somebody else uh +hey, you don't have to go to all the + + align:start position:0% +hey, you don't have to go to all the + + + align:start position:0% +hey, you don't have to go to all the +trouble to feed the young. So, in the + + align:start position:0% +trouble to feed the young. So, in the + + + align:start position:0% +trouble to feed the young. So, in the +natural + + align:start position:0% +natural + + + align:start position:0% +natural +world, our moral uh the way we think of + + align:start position:0% +world, our moral uh the way we think of + + + align:start position:0% +world, our moral uh the way we think of +our society and a moral framework is is + + align:start position:0% +our society and a moral framework is is + + + align:start position:0% +our society and a moral framework is is +pretty much absent in the natural world. + + align:start position:0% +pretty much absent in the natural world. + + + align:start position:0% +pretty much absent in the natural world. +I mean things just basically are have a + + align:start position:0% +I mean things just basically are have a + + + align:start position:0% +I mean things just basically are have a +fundamental utilitarian. Is that right? + + align:start position:0% +fundamental utilitarian. Is that right? + + + align:start position:0% +fundamental utilitarian. Is that right? +Is that what you're going to I was just + + align:start position:0% +Is that what you're going to I was just + + + align:start position:0% +Is that what you're going to I was just +going to add to the question that you + + align:start position:0% +going to add to the question that you + + + align:start position:0% +going to add to the question that you +asked. Well, I think that if you so like + + align:start position:0% +asked. Well, I think that if you so like + + + align:start position:0% +asked. Well, I think that if you so like +basically Darwin's principle is based on + + align:start position:0% +basically Darwin's principle is based on + + + align:start position:0% +basically Darwin's principle is based on +like how nature has there's like a like + + align:start position:0% +like how nature has there's like a like + + + align:start position:0% +like how nature has there's like a like +nature the selection process in nature + + align:start position:0% +nature the selection process in nature + + + align:start position:0% +nature the selection process in nature +is like an invisible hand. And if you + + align:start position:0% +is like an invisible hand. And if you + + + align:start position:0% +is like an invisible hand. And if you +try to strengthen those principles, you + + align:start position:0% +try to strengthen those principles, you + + + align:start position:0% +try to strengthen those principles, you +decrease the chance of something that's + + align:start position:0% +decrease the chance of something that's + + + align:start position:0% +decrease the chance of something that's +not like that's not fit to survive like + + align:start position:0% +not like that's not fit to survive like + + + align:start position:0% +not like that's not fit to survive like +the chance of that something to survive + + align:start position:0% +the chance of that something to survive + + + align:start position:0% +the chance of that something to survive +like you make sure that if something is + + align:start position:0% +like you make sure that if something is + + + align:start position:0% +like you make sure that if something is +even the least bit um incompatible with + + align:start position:0% +even the least bit um incompatible with + + + align:start position:0% +even the least bit um incompatible with +its surroundings that it gets eliminated + + align:start position:0% +its surroundings that it gets eliminated + + + align:start position:0% +its surroundings that it gets eliminated +immediately. Yeah, I think like the + + align:start position:0% +immediately. Yeah, I think like the + + + align:start position:0% +immediately. Yeah, I think like the +result of this um would be like like + + align:start position:0% +result of this um would be like like + + + align:start position:0% +result of this um would be like like +suppose you had like obviously every + + align:start position:0% +suppose you had like obviously every + + + align:start position:0% +suppose you had like obviously every +person is multiaceted and you might not + + align:start position:0% +person is multiaceted and you might not + + + align:start position:0% +person is multiaceted and you might not +be so great at one thing but you might + + align:start position:0% +be so great at one thing but you might + + + align:start position:0% +be so great at one thing but you might +have a hidden talent and if you select + + align:start position:0% +have a hidden talent and if you select + + + align:start position:0% +have a hidden talent and if you select +against this person before they discover + + align:start position:0% +against this person before they discover + + + align:start position:0% +against this person before they discover +what they're good at before they find + + align:start position:0% +what they're good at before they find + + + align:start position:0% +what they're good at before they find +like their little corner in the world + + align:start position:0% +like their little corner in the world + + + align:start position:0% +like their little corner in the world +where they're good at doing something + + align:start position:0% +where they're good at doing something + + + align:start position:0% +where they're good at doing something +that can help the rest. like you're + + align:start position:0% +that can help the rest. like you're + + + align:start position:0% +that can help the rest. like you're +eliminating a lot of possibilities and + + align:start position:0% +eliminating a lot of possibilities and + + + align:start position:0% +eliminating a lot of possibilities and +so like in some ways you're selecting + + align:start position:0% +so like in some ways you're selecting + + + align:start position:0% +so like in some ways you're selecting +for the best but like you're also + + align:start position:0% +for the best but like you're also + + + align:start position:0% +for the best but like you're also +narrowing down and like there's only so + + align:start position:0% +narrowing down and like there's only so + + + align:start position:0% +narrowing down and like there's only so +much that a very narrow and not very + + align:start position:0% +much that a very narrow and not very + + + align:start position:0% +much that a very narrow and not very +like + + align:start position:0% +like + + + align:start position:0% +like +multi-purpose serving like community can + + align:start position:0% +multi-purpose serving like community can + + + align:start position:0% +multi-purpose serving like community can +do like not lot of variety. Yeah. Uh + + align:start position:0% +do like not lot of variety. Yeah. Uh + + + align:start position:0% +do like not lot of variety. Yeah. Uh +humans uh in in in this little work + + align:start position:0% +humans uh in in in this little work + + + align:start position:0% +humans uh in in in this little work +uh in Arowan are kind of uh + + align:start position:0% +uh in Arowan are kind of uh + + + align:start position:0% +uh in Arowan are kind of uh +uh they have + + align:start position:0% +uh they have + + + align:start position:0% +uh they have +adopted a + + align:start position:0% +adopted a + + + align:start position:0% +adopted a +philosophy that is based + + align:start position:0% +philosophy that is based + + + align:start position:0% +philosophy that is based +on natural world type of dynamics that + + align:start position:0% +on natural world type of dynamics that + + + align:start position:0% +on natural world type of dynamics that +we find which Butler found in in in in + + align:start position:0% +we find which Butler found in in in in + + + align:start position:0% +we find which Butler found in in in in +Darwin's uh uh + + align:start position:0% +Darwin's uh uh + + + align:start position:0% +Darwin's uh uh +origin and that dynamic is + + align:start position:0% +origin and that dynamic is + + + align:start position:0% +origin and that dynamic is +manifestly and very obviously hugely + + align:start position:0% +manifestly and very obviously hugely + + + align:start position:0% +manifestly and very obviously hugely +different from the world that we live + + align:start position:0% +different from the world that we live + + + align:start position:0% +different from the world that we live +in. We do not select people in our + + align:start position:0% +in. We do not select people in our + + + align:start position:0% +in. We do not select people in our +society uh and punish them for being ill + + align:start position:0% +society uh and punish them for being ill + + + align:start position:0% +society uh and punish them for being ill +do + + align:start position:0% +do + + + align:start position:0% +do +we David? Uh we don't but we do + + align:start position:0% +we David? Uh we don't but we do + + + align:start position:0% +we David? Uh we don't but we do +um sort of reward those who are who like + + align:start position:0% +um sort of reward those who are who like + + + align:start position:0% +um sort of reward those who are who like +are better and like I say this like + + align:start position:0% +are better and like I say this like + + + align:start position:0% +are better and like I say this like +physical appearance like people who are + + align:start position:0% +physical appearance like people who are + + + align:start position:0% +physical appearance like people who are +who look better usually make more money + + align:start position:0% +who look better usually make more money + + + align:start position:0% +who look better usually make more money +um whether or not you if you're taller + + align:start position:0% +um whether or not you if you're taller + + + align:start position:0% +um whether or not you if you're taller +you uh by each inch adds so much to your + + align:start position:0% +you uh by each inch adds so much to your + + + align:start position:0% +you uh by each inch adds so much to your +average there's actually I read an + + align:start position:0% +average there's actually I read an + + + align:start position:0% +average there's actually I read an +article about how + + align:start position:0% +article about how + + + align:start position:0% +article about how +I don't I read an article about how + + align:start position:0% +I don't I read an article about how + + + align:start position:0% +I don't I read an article about how +there was an appearance bias and how + + align:start position:0% +there was an appearance bias and how + + + align:start position:0% +there was an appearance bias and how +people are now trying to like get + + align:start position:0% +people are now trying to like get + + + align:start position:0% +people are now trying to like get +legislation to stop that cuz um it was + + align:start position:0% +legislation to stop that cuz um it was + + + align:start position:0% +legislation to stop that cuz um it was +unequal. But so part of what you're + + align:start position:0% +unequal. But so part of what you're + + + align:start position:0% +unequal. But so part of what you're +saying is we fight we fight socially + + align:start position:0% +saying is we fight we fight socially + + + align:start position:0% +saying is we fight we fight socially +against evolutionary pressures + + align:start position:0% +against evolutionary pressures + + + align:start position:0% +against evolutionary pressures +evolutionary pressures. That's what our + + align:start position:0% +evolutionary pressures. That's what our + + + align:start position:0% +evolutionary pressures. That's what our +laws are. Our laws for equity and + + align:start position:0% +laws are. Our laws for equity and + + + align:start position:0% +laws are. Our laws for equity and +equality and so forth are trying to + + align:start position:0% +equality and so forth are trying to + + + align:start position:0% +equality and so forth are trying to +fight + + align:start position:0% +fight + + + align:start position:0% +fight +against any kind of uh natural selection + + align:start position:0% +against any kind of uh natural selection + + + align:start position:0% +against any kind of uh natural selection +principles because the world the natural + + align:start position:0% +principles because the world the natural + + + align:start position:0% +principles because the world the natural +world of Darwin is not the model for the + + align:start position:0% +world of Darwin is not the model for the + + + align:start position:0% +world of Darwin is not the model for the +social world of + + align:start position:0% +social world of + + + align:start position:0% +social world of +humans. And to the degree that you see + + align:start position:0% +humans. And to the degree that you see + + + align:start position:0% +humans. And to the degree that you see +the absurdity of these uh arrangements + + align:start position:0% +the absurdity of these uh arrangements + + + align:start position:0% +the absurdity of these uh arrangements +where they're punishing people for being + + align:start position:0% +where they're punishing people for being + + + align:start position:0% +where they're punishing people for being +ill and you think that's really not + + align:start position:0% +ill and you think that's really not + + + align:start position:0% +ill and you think that's really not +right, you are basically + + align:start position:0% +right, you are basically + + + align:start position:0% +right, you are basically +reflecting a uh idea of the world that + + align:start position:0% +reflecting a uh idea of the world that + + + align:start position:0% +reflecting a uh idea of the world that +we try to cultivate in our societies. So + + align:start position:0% +we try to cultivate in our societies. So + + + align:start position:0% +we try to cultivate in our societies. So +our societies are not based on + + align:start position:0% +our societies are not based on + + + align:start position:0% +our societies are not based on +evolutionary principles in the sense + + align:start position:0% +evolutionary principles in the sense + + + align:start position:0% +evolutionary principles in the sense +that we're using those evolutionary + + align:start position:0% +that we're using those evolutionary + + + align:start position:0% +that we're using those evolutionary +principles to + + align:start position:0% +principles to + + + align:start position:0% +principles to +uh create the rules of the societ the + + align:start position:0% +uh create the rules of the societ the + + + align:start position:0% +uh create the rules of the societ the +behavior of the + + align:start position:0% +behavior of the + + + align:start position:0% +behavior of the +society. I don't know if this is all + + align:start position:0% +society. I don't know if this is all + + + align:start position:0% +society. I don't know if this is all +coming through. Maybe this this work is + + align:start position:0% +coming through. Maybe this this work is + + + align:start position:0% +coming through. Maybe this this work is +uh yeah Chris I think if we did apply + + align:start position:0% +uh yeah Chris I think if we did apply + + + align:start position:0% +uh yeah Chris I think if we did apply +Dar Darwin's principles to society we + + align:start position:0% +Dar Darwin's principles to society we + + + align:start position:0% +Dar Darwin's principles to society we +converge to a bunch of like type A + + align:start position:0% +converge to a bunch of like type A + + + align:start position:0% +converge to a bunch of like type A +individuals you know always on their + + align:start position:0% +individuals you know always on their + + + align:start position:0% +individuals you know always on their +blackberries always trying to produce as + + align:start position:0% +blackberries always trying to produce as + + + align:start position:0% +blackberries always trying to produce as +much trying to micromanage trying to + + align:start position:0% +much trying to micromanage trying to + + + align:start position:0% +much trying to micromanage trying to +produce as much as they can to gain as + + align:start position:0% +produce as much as they can to gain as + + + align:start position:0% +produce as much as they can to gain as +much revenue as they can and outlast + + align:start position:0% +much revenue as they can and outlast + + + align:start position:0% +much revenue as they can and outlast +everyone else. + + align:start position:0% +everyone else. + + + align:start position:0% +everyone else. +Okay. Uh well yeah maybe so uh but a lot + + align:start position:0% +Okay. Uh well yeah maybe so uh but a lot + + + align:start position:0% +Okay. Uh well yeah maybe so uh but a lot +of these people work within the rules + + align:start position:0% +of these people work within the rules + + + align:start position:0% +of these people work within the rules +you know within the laws. So we have a + + align:start position:0% +you know within the laws. So we have a + + + align:start position:0% +you know within the laws. So we have a +whole law we we have laws and a whole + + align:start position:0% +whole law we we have laws and a whole + + + align:start position:0% +whole law we we have laws and a whole +system of + + align:start position:0% +system of + + + align:start position:0% +system of +regulation of social behavior that we + + align:start position:0% +regulation of social behavior that we + + + align:start position:0% +regulation of social behavior that we +uh that we promulgate in order to + + align:start position:0% +uh that we promulgate in order to + + + align:start position:0% +uh that we promulgate in order to +avoid simply uh might makes right. I + + align:start position:0% +avoid simply uh might makes right. I + + + align:start position:0% +avoid simply uh might makes right. I +mean, might makes right in nature, does + + align:start position:0% +mean, might makes right in nature, does + + + align:start position:0% +mean, might makes right in nature, does +it not? + + align:start position:0% +it not? + + + align:start position:0% +it not? +Might is not supposed to make right in + + align:start position:0% +Might is not supposed to make right in + + + align:start position:0% +Might is not supposed to make right in +our society, is it? + + align:start position:0% + + + + align:start position:0% + +It's not supposed Yeah. Sometimes we + + align:start position:0% +It's not supposed Yeah. Sometimes we + + + align:start position:0% +It's not supposed Yeah. Sometimes we +wonder, but yeah, I'm going to disagree + + align:start position:0% +wonder, but yeah, I'm going to disagree + + + align:start position:0% +wonder, but yeah, I'm going to disagree +with pretty much everything that's been + + align:start position:0% +with pretty much everything that's been + + + align:start position:0% +with pretty much everything that's been +said in the last five minutes because I + + align:start position:0% +said in the last five minutes because I + + + align:start position:0% +said in the last five minutes because I +think our society is much closer than to + + align:start position:0% +think our society is much closer than to + + + align:start position:0% +think our society is much closer than to +this than we're willing to admit. We + + align:start position:0% +this than we're willing to admit. We + + + align:start position:0% +this than we're willing to admit. We +absolutely punish people for illness. + + align:start position:0% +absolutely punish people for illness. + + + align:start position:0% +absolutely punish people for illness. +Anytime someone is schizophrenic or + + align:start position:0% +Anytime someone is schizophrenic or + + + align:start position:0% +Anytime someone is schizophrenic or +bipolar or you know has this stuff we + + align:start position:0% +bipolar or you know has this stuff we + + + align:start position:0% +bipolar or you know has this stuff we +put them on drugs we lock them in + + align:start position:0% +put them on drugs we lock them in + + + align:start position:0% +put them on drugs we lock them in +hospitals if someone's underachieving + + align:start position:0% +hospitals if someone's underachieving + + + align:start position:0% +hospitals if someone's underachieving +they suddenly get punished not in a + + align:start position:0% +they suddenly get punished not in a + + + align:start position:0% +they suddenly get punished not in a +direct way but they absolutely get + + align:start position:0% +direct way but they absolutely get + + + align:start position:0% +direct way but they absolutely get +pushed down to a level of society that + + align:start position:0% +pushed down to a level of society that + + + align:start position:0% +pushed down to a level of society that +can absolutely be considered punishment + + align:start position:0% +can absolutely be considered punishment + + + align:start position:0% +can absolutely be considered punishment +we're not willing to look we don't want + + align:start position:0% +we're not willing to look we don't want + + + align:start position:0% +we're not willing to look we don't want +to look at our world and say that's it + + align:start position:0% +to look at our world and say that's it + + + align:start position:0% +to look at our world and say that's it +and so we can step aside but I will + + align:start position:0% +and so we can step aside but I will + + + align:start position:0% +and so we can step aside but I will +stand firm absolutely that we do this + + align:start position:0% +stand firm absolutely that we do this + + + align:start position:0% +stand firm absolutely that we do this +all the time well but there's punishment + + align:start position:0% +all the time well but there's punishment + + + align:start position:0% +all the time well but there's punishment +in the sense that they get like looked + + align:start position:0% +in the sense that they get like looked + + + align:start position:0% +in the sense that they get like looked +down on by society but it's not + + align:start position:0% +down on by society but it's not + + + align:start position:0% +down on by society but it's not +punishment and they don't actually + + align:start position:0% +punishment and they don't actually + + + align:start position:0% +punishment and they don't actually +reproduce. Well, how do you how do you + + align:start position:0% +reproduce. Well, how do you how do you + + + align:start position:0% +reproduce. Well, how do you how do you +want to make them because the thing is + + align:start position:0% +want to make them because the thing is + + + align:start position:0% +want to make them because the thing is +is you can change the metrics slightly, + + align:start position:0% +is you can change the metrics slightly, + + + align:start position:0% +is you can change the metrics slightly, +but once you can pick whatever you want, + + align:start position:0% +but once you can pick whatever you want, + + + align:start position:0% +but once you can pick whatever you want, +but we'll always have that kind that + + align:start position:0% +but we'll always have that kind that + + + align:start position:0% +but we'll always have that kind that +form of punishment. And one of the + + align:start position:0% +form of punishment. And one of the + + + align:start position:0% +form of punishment. And one of the +things is, you know, if you steal a + + align:start position:0% +things is, you know, if you steal a + + + align:start position:0% +things is, you know, if you steal a +watch that morals can be at least + + align:start position:0% +watch that morals can be at least + + + align:start position:0% +watch that morals can be at least +according to this this culture, morals + + align:start position:0% +according to this this culture, morals + + + align:start position:0% +according to this this culture, morals +are sculpted. Morals can be moved, but + + align:start position:0% +are sculpted. Morals can be moved, but + + + align:start position:0% +are sculpted. Morals can be moved, but +when you have genetic material, you + + align:start position:0% +when you have genetic material, you + + + align:start position:0% +when you have genetic material, you +can't change that. So, if someone's + + align:start position:0% +can't change that. So, if someone's + + + align:start position:0% +can't change that. So, if someone's +sick, lock them away because there's + + align:start position:0% +sick, lock them away because there's + + + align:start position:0% +sick, lock them away because there's +without technology, there's nothing we + + align:start position:0% +without technology, there's nothing we + + + align:start position:0% +without technology, there's nothing we +can do to fix that. But if we have a + + align:start position:0% +can do to fix that. But if we have a + + + align:start position:0% +can do to fix that. But if we have a +good, you know, upstanding moral code, + + align:start position:0% +good, you know, upstanding moral code, + + + align:start position:0% +good, you know, upstanding moral code, +we can send someone to a straightener + + align:start position:0% +we can send someone to a straightener + + + align:start position:0% +we can send someone to a straightener +and just correct their kind of cognitive + + align:start position:0% +and just correct their kind of cognitive + + + align:start position:0% +and just correct their kind of cognitive +structures to make everything better. + + align:start position:0% +structures to make everything better. + + + align:start position:0% +structures to make everything better. +With like with + + align:start position:0% +With like with + + + align:start position:0% +With like with +evolutionary punishment is like just in + + align:start position:0% +evolutionary punishment is like just in + + + align:start position:0% +evolutionary punishment is like just in +a singular sense not allowing somebody + + align:start position:0% +a singular sense not allowing somebody + + + align:start position:0% +a singular sense not allowing somebody +to reproduce. And there are plenty of + + align:start position:0% +to reproduce. And there are plenty of + + + align:start position:0% +to reproduce. And there are plenty of +like sickly individuals who if they were + + align:start position:0% +like sickly individuals who if they were + + + align:start position:0% +like sickly individuals who if they were +parts of herds out in nature, they + + align:start position:0% +parts of herds out in nature, they + + + align:start position:0% +parts of herds out in nature, they +wouldn't be allowed to reproduce and + + align:start position:0% +wouldn't be allowed to reproduce and + + + align:start position:0% +wouldn't be allowed to reproduce and +they wouldn't persist. But for us, we + + align:start position:0% +they wouldn't persist. But for us, we + + + align:start position:0% +they wouldn't persist. But for us, we +are allowed to. So I agree that yes, + + align:start position:0% +are allowed to. So I agree that yes, + + + align:start position:0% +are allowed to. So I agree that yes, +like sick certain sicknesses are + + align:start position:0% +like sick certain sicknesses are + + + align:start position:0% +like sick certain sicknesses are +punished in a certain sense, but if + + align:start position:0% +punished in a certain sense, but if + + + align:start position:0% +punished in a certain sense, but if +you're talking about like evolutionary + + align:start position:0% +you're talking about like evolutionary + + + align:start position:0% +you're talking about like evolutionary +mechanisms, I don't really think that we + + align:start position:0% +mechanisms, I don't really think that we + + + align:start position:0% +mechanisms, I don't really think that we +punish for that. + + align:start position:0% +punish for that. + + + align:start position:0% +punish for that. +Okay. Yeah. Well, you know, I I I I have + + align:start position:0% +Okay. Yeah. Well, you know, I I I I have + + + align:start position:0% +Okay. Yeah. Well, you know, I I I I have +to say uh I think you're both right + + align:start position:0% +to say uh I think you're both right + + + align:start position:0% +to say uh I think you're both right +because this is what this is what + + align:start position:0% +because this is what this is what + + + align:start position:0% +because this is what this is what +Butler's trying to do. He's trying to + + align:start position:0% +Butler's trying to do. He's trying to + + + align:start position:0% +Butler's trying to do. He's trying to +make us think a little more deeply about + + align:start position:0% +make us think a little more deeply about + + + align:start position:0% +make us think a little more deeply about +how people really do behave. the + + align:start position:0% +how people really do behave. the + + + align:start position:0% +how people really do behave. the +development of eugenics in the 19th + + align:start position:0% +development of eugenics in the 19th + + + align:start position:0% +development of eugenics in the 19th +century. Uh so we're we're we're + + align:start position:0% +century. Uh so we're we're we're + + + align:start position:0% +century. Uh so we're we're we're +starting we're we're getting in this + + align:start position:0% +starting we're we're getting in this + + + align:start position:0% +starting we're we're getting in this +book is taking us into that + + align:start position:0% +book is taking us into that + + + align:start position:0% +book is taking us into that +territory. It's a it's a satire. So it's + + align:start position:0% +territory. It's a it's a satire. So it's + + + align:start position:0% +territory. It's a it's a satire. So it's +you know he's not recommending anything + + align:start position:0% +you know he's not recommending anything + + + align:start position:0% +you know he's not recommending anything +in this book. It's just it's a book to + + align:start position:0% +in this book. It's just it's a book to + + + align:start position:0% +in this book. It's just it's a book to +try to make you think to make you think + + align:start position:0% +try to make you think to make you think + + + align:start position:0% +try to make you think to make you think +about you know what is the base of your + + align:start position:0% +about you know what is the base of your + + + align:start position:0% +about you know what is the base of your +society. Is your society + + align:start position:0% +society. Is your society + + + align:start position:0% +society. Is your society +uh entirely a natural thing, an + + align:start position:0% +uh entirely a natural thing, an + + + align:start position:0% +uh entirely a natural thing, an +expression of natural principles, or is + + align:start position:0% +expression of natural principles, or is + + + align:start position:0% +expression of natural principles, or is +it something quite + + align:start position:0% +it something quite + + + align:start position:0% +it something quite +different? It's an effort to + + align:start position:0% +different? It's an effort to + + + align:start position:0% +different? It's an effort to +fight the the the world or to resist + + align:start position:0% +fight the the the world or to resist + + + align:start position:0% +fight the the the world or to resist +becoming part of this natural + + align:start position:0% +becoming part of this natural + + + align:start position:0% +becoming part of this natural +world that Darwin had painted with such + + align:start position:0% +world that Darwin had painted with such + + + align:start position:0% +world that Darwin had painted with such +force and compelling. + + align:start position:0% +force and compelling. + + + align:start position:0% +force and compelling. +uh uh + + align:start position:0% +uh uh + + + align:start position:0% +uh uh +detail. And so Butler is saying, "Okay, + + align:start position:0% +detail. And so Butler is saying, "Okay, + + + align:start position:0% +detail. And so Butler is saying, "Okay, +that world exists out there." But is + + align:start position:0% +that world exists out there." But is + + + align:start position:0% +that world exists out there." But is +that the world in which we exist? Are we + + align:start position:0% +that the world in which we exist? Are we + + + align:start position:0% +that the world in which we exist? Are we +trying to create that, recreate that + + align:start position:0% +trying to create that, recreate that + + + align:start position:0% +trying to create that, recreate that +world? And I agree with Devon. I I I I + + align:start position:0% +world? And I agree with Devon. I I I I + + + align:start position:0% +world? And I agree with Devon. I I I I +think I think his answer is highly + + align:start position:0% +think I think his answer is highly + + + align:start position:0% +think I think his answer is highly +ambiguous because yes, ostensibly we + + align:start position:0% +ambiguous because yes, ostensibly we + + + align:start position:0% +ambiguous because yes, ostensibly we +fight against what we call + + align:start position:0% +fight against what we call + + + align:start position:0% +fight against what we call +injustice. You know, the punishment of + + align:start position:0% +injustice. You know, the punishment of + + + align:start position:0% +injustice. You know, the punishment of +the weak and you know, holding people + + align:start position:0% +the weak and you know, holding people + + + align:start position:0% +the weak and you know, holding people +who are unfortunate to uh uh in in some + + align:start position:0% +who are unfortunate to uh uh in in some + + + align:start position:0% +who are unfortunate to uh uh in in some +way as as responsible for their + + align:start position:0% +way as as responsible for their + + + align:start position:0% +way as as responsible for their +misfortunes. + + align:start position:0% +misfortunes. + + + align:start position:0% +misfortunes. +But there there are it's it's not just + + align:start position:0% +But there there are it's it's not just + + + align:start position:0% +But there there are it's it's not just +that simple. There there are other + + align:start position:0% +that simple. There there are other + + + align:start position:0% +that simple. There there are other +elements that we still express in spite + + align:start position:0% +elements that we still express in spite + + + align:start position:0% +elements that we still express in spite +of ourselves or in spite of, you know, + + align:start position:0% +of ourselves or in spite of, you know, + + + align:start position:0% +of ourselves or in spite of, you know, +the the ideals that we espouse with our + + align:start position:0% +the the ideals that we espouse with our + + + align:start position:0% +the the ideals that we espouse with our +our laws and our social and our + + align:start position:0% +our laws and our social and our + + + align:start position:0% +our laws and our social and our +religious principles. + + align:start position:0% +religious principles. + + + align:start position:0% +religious principles. +And + + align:start position:0% +And + + + align:start position:0% +And +so he's not arguing for he's just trying + + align:start position:0% +so he's not arguing for he's just trying + + + align:start position:0% +so he's not arguing for he's just trying +to make you think about this and and + + align:start position:0% +to make you think about this and and + + + align:start position:0% +to make you think about this and and +sift through the world you live in and + + align:start position:0% +sift through the world you live in and + + + align:start position:0% +sift through the world you live in and +try to understand it in a little more + + align:start position:0% +try to understand it in a little more + + + align:start position:0% +try to understand it in a little more +complex + + align:start position:0% +complex + + + align:start position:0% +complex +way. So why why are these people so down + + align:start position:0% +way. So why why are these people so down + + + align:start position:0% +way. So why why are these people so down +on machines? What is it about machines + + align:start position:0% +on machines? What is it about machines + + + align:start position:0% +on machines? What is it about machines +that they think compromises their + + align:start position:0% +that they think compromises their + + + align:start position:0% +that they think compromises their +society? Because they you know they find + + align:start position:0% +society? Because they you know they find + + + align:start position:0% +society? Because they you know they find +his watch and he gets thrown in jail. + + align:start position:0% + + + + align:start position:0% + +And he he he can't resist uh mentioning + + align:start position:0% +And he he he can't resist uh mentioning + + + align:start position:0% +And he he he can't resist uh mentioning +Paley says uh Paley said that uh even + + align:start position:0% +Paley says uh Paley said that uh even + + + align:start position:0% +Paley says uh Paley said that uh even +quote a savage who saw this watch would + + align:start position:0% +quote a savage who saw this watch would + + + align:start position:0% +quote a savage who saw this watch would +know it was made by you know some some + + align:start position:0% +know it was made by you know some some + + + align:start position:0% +know it was made by you know some some +deliberate force and so on and so forth. + + align:start position:0% +deliberate force and so on and so forth. + + + align:start position:0% +deliberate force and so on and so forth. +Why why are these people why is this + + align:start position:0% +Why why are these people why is this + + + align:start position:0% +Why why are these people why is this +culture so afraid of watches? Kevin uh + + align:start position:0% +culture so afraid of watches? Kevin uh + + + align:start position:0% +culture so afraid of watches? Kevin uh +to pull out a quote. I learned about + + align:start position:0% +to pull out a quote. I learned about + + + align:start position:0% +to pull out a quote. I learned about +four that 400 years previously the state + + align:start position:0% +four that 400 years previously the state + + + align:start position:0% +four that 400 years previously the state +of mechanical knowledge was so far + + align:start position:0% +of mechanical knowledge was so far + + + align:start position:0% +of mechanical knowledge was so far +beyond our own and was so adv advancing + + align:start position:0% +beyond our own and was so adv advancing + + + align:start position:0% +beyond our own and was so adv advancing +uh until one of the most learned + + align:start position:0% +uh until one of the most learned + + + align:start position:0% +uh until one of the most learned +professors of hypothetics wrote an + + align:start position:0% +professors of hypothetics wrote an + + + align:start position:0% +professors of hypothetics wrote an +extraordinary book from which I proposed + + align:start position:0% +extraordinary book from which I proposed + + + align:start position:0% +extraordinary book from which I proposed +to give extracts later on proving that + + align:start position:0% +to give extracts later on proving that + + + align:start position:0% +to give extracts later on proving that +machines were ultimately destined to + + align:start position:0% +machines were ultimately destined to + + + align:start position:0% +machines were ultimately destined to +supplant the race of man and to become + + align:start position:0% +supplant the race of man and to become + + + align:start position:0% +supplant the race of man and to become +uh to become uh instinct in the vitality + + align:start position:0% +uh to become uh instinct in the vitality + + + align:start position:0% +uh to become uh instinct in the vitality +of it different form and superior to + + align:start position:0% +of it different form and superior to + + + align:start position:0% +of it different form and superior to +that of animals as animals and vegetable + + align:start position:0% +that of animals as animals and vegetable + + + align:start position:0% +that of animals as animals and vegetable +life. So, okay, prophet wrote a book + + align:start position:0% +life. So, okay, prophet wrote a book + + + align:start position:0% +life. So, okay, prophet wrote a book +that is that is the the mad professor + + align:start position:0% +that is that is the the mad professor + + + align:start position:0% +that is that is the the mad professor +who we're going to read his his his his + + align:start position:0% +who we're going to read his his his his + + + align:start position:0% +who we're going to read his his his his +uh his theories for the next class + + align:start position:0% +uh his theories for the next class + + + align:start position:0% +uh his theories for the next class +because he has this whole theory about + + align:start position:0% +because he has this whole theory about + + + align:start position:0% +because he has this whole theory about +these machines having the + + align:start position:0% +these machines having the + + + align:start position:0% +these machines having the +capacity to + + align:start position:0% +capacity to + + + align:start position:0% +capacity to +evolve. They don't necessarily do it all + + align:start position:0% +evolve. They don't necessarily do it all + + + align:start position:0% +evolve. They don't necessarily do it all +by themselves but they have help from + + align:start position:0% +by themselves but they have help from + + + align:start position:0% +by themselves but they have help from +humans. But you know there are many + + align:start position:0% +humans. But you know there are many + + + align:start position:0% +humans. But you know there are many +examples in nature where other organisms + + align:start position:0% +examples in nature where other organisms + + + align:start position:0% +examples in nature where other organisms +help uh other organisms uh + + align:start position:0% +help uh other organisms uh + + + align:start position:0% +help uh other organisms uh +u + + align:start position:0% +u + + + align:start position:0% +u +reproduce. So we're going to get into + + align:start position:0% +reproduce. So we're going to get into + + + align:start position:0% +reproduce. So we're going to get into +that in in a big way for next class. But + + align:start position:0% +that in in a big way for next class. But + + + align:start position:0% +that in in a big way for next class. But +that's that's part of it. So they're + + align:start position:0% +that's that's part of it. So they're + + + align:start position:0% +that's that's part of it. So they're +potential + + align:start position:0% +potential + + + align:start position:0% +potential +competition. What are these machines + + align:start position:0% +competition. What are these machines + + + align:start position:0% +competition. What are these machines +also doing as far as the fitness of the + + align:start position:0% +also doing as far as the fitness of the + + + align:start position:0% +also doing as far as the fitness of the +individual? + + align:start position:0% + + + + align:start position:0% + +What do machines do machines have any + + align:start position:0% +What do machines do machines have any + + + align:start position:0% +What do machines do machines have any +impact on the uh the fitness of the + + align:start position:0% +impact on the uh the fitness of the + + + align:start position:0% +impact on the uh the fitness of the +individual? Jennifer, + + align:start position:0% +individual? Jennifer, + + + align:start position:0% +individual? Jennifer, +um feel like they're kind of like a way + + align:start position:0% +um feel like they're kind of like a way + + + align:start position:0% +um feel like they're kind of like a way +of like cheating yet. I mean, as I've + + align:start position:0% +of like cheating yet. I mean, as I've + + + align:start position:0% +of like cheating yet. I mean, as I've +said to you, if I don't have my + + align:start position:0% +said to you, if I don't have my + + + align:start position:0% +said to you, if I don't have my +glasses and I live in a a world that uh + + align:start position:0% +glasses and I live in a a world that uh + + + align:start position:0% +glasses and I live in a a world that uh +you know, so these allow + + align:start position:0% +you know, so these allow + + + align:start position:0% +you know, so these allow +me to survive on a + + align:start position:0% +me to survive on a + + + align:start position:0% +me to survive on a +par with other people, + + align:start position:0% +par with other people, + + + align:start position:0% +par with other people, +but what happens to my offspring + + align:start position:0% +but what happens to my offspring + + + align:start position:0% +but what happens to my offspring +potentially? + + align:start position:0% +potentially? + + + align:start position:0% +potentially? +Yes. Then they also like wouldn't be + + align:start position:0% +Yes. Then they also like wouldn't be + + + align:start position:0% +Yes. Then they also like wouldn't be +able to see it. So I feel like the more + + align:start position:0% +able to see it. So I feel like the more + + + align:start position:0% +able to see it. So I feel like the more +you have to rely on machines, the less + + align:start position:0% +you have to rely on machines, the less + + + align:start position:0% +you have to rely on machines, the less +fit you have to be. So it's kind of + + align:start position:0% +fit you have to be. So it's kind of + + + align:start position:0% +fit you have to be. So it's kind of +Absolutely. Absolutely. So more + + align:start position:0% +Absolutely. Absolutely. So more + + + align:start position:0% +Absolutely. Absolutely. So more +machines, less fit. That's why the + + align:start position:0% +machines, less fit. That's why the + + + align:start position:0% +machines, less fit. That's why the +Armonians are so upset about machines + + align:start position:0% +Armonians are so upset about machines + + + align:start position:0% +Armonians are so upset about machines +because they're trying to emulate + + align:start position:0% +because they're trying to emulate + + + align:start position:0% +because they're trying to emulate +nature. Uh and machines allow less fit + + align:start position:0% +nature. Uh and machines allow less fit + + + align:start position:0% +nature. Uh and machines allow less fit +people to operate on a + + align:start position:0% +people to operate on a + + + align:start position:0% +people to operate on a +par. So they get rid of machines. + + align:start position:0% +par. So they get rid of machines. + + + align:start position:0% +par. So they get rid of machines. +Uh + + align:start position:0% +Uh + + + align:start position:0% +Uh +okay. So this is a society with a + + align:start position:0% +okay. So this is a society with a + + + align:start position:0% +okay. So this is a society with a +vengeance trying to uh just uh adopt the + + align:start position:0% +vengeance trying to uh just uh adopt the + + + align:start position:0% +vengeance trying to uh just uh adopt the +principles of uh uh natural selection in + + align:start position:0% +principles of uh uh natural selection in + + + align:start position:0% +principles of uh uh natural selection in +the natural world as the + + align:start position:0% +the natural world as the + + + align:start position:0% +the natural world as the +code for their social and cultural + + align:start position:0% + + + + align:start position:0% + +behavior. And you can see what the + + align:start position:0% +behavior. And you can see what the + + + align:start position:0% +behavior. And you can see what the +results + + align:start position:0% +results + + + align:start position:0% +results +are. They're very very beautiful. + + align:start position:0% +are. They're very very beautiful. + + + align:start position:0% +are. They're very very beautiful. +Remember what he says. They all look + + align:start position:0% +Remember what he says. They all look + + + align:start position:0% +Remember what he says. They all look +like they're and you know if somebody's + + align:start position:0% +like they're and you know if somebody's + + + align:start position:0% +like they're and you know if somebody's +ill, they don't tell + + align:start position:0% +ill, they don't tell + + + align:start position:0% +ill, they don't tell +anybody. You want somebody to know that + + align:start position:0% +anybody. You want somebody to know that + + + align:start position:0% +anybody. You want somebody to know that +you're ill because uh that exposes you + + align:start position:0% +you're ill because uh that exposes you + + + align:start position:0% +you're ill because uh that exposes you +to their, you know, judgment and you may + + align:start position:0% +to their, you know, judgment and you may + + + align:start position:0% +to their, you know, judgment and you may +ultimately find yourself uh in the + + align:start position:0% +ultimately find yourself uh in the + + + align:start position:0% +ultimately find yourself uh in the +docket in + + align:start position:0% +docket in + + + align:start position:0% +docket in +court, personal bere bereavement court. + + align:start position:0% +court, personal bere bereavement court. + + + align:start position:0% +court, personal bere bereavement court. +that young man whose wife + + align:start position:0% +that young man whose wife + + + align:start position:0% +that young man whose wife +died. He what did he have to argue in + + align:start position:0% +died. He what did he have to argue in + + + align:start position:0% +died. He what did he have to argue in +order to get some kind of uh uh uh + + align:start position:0% +order to get some kind of uh uh uh + + + align:start position:0% +order to get some kind of uh uh uh +better sentence from the court? + + align:start position:0% + + + + align:start position:0% + +remember he said a uh the court said an + + align:start position:0% +remember he said a uh the court said an + + + align:start position:0% +remember he said a uh the court said an +extenduating circumstance was that he + + align:start position:0% +extenduating circumstance was that he + + + align:start position:0% +extenduating circumstance was that he +took out an insurance policy on his wife + + align:start position:0% +took out an insurance policy on his wife + + + align:start position:0% +took out an insurance policy on his wife +before so therefore he had a little bit + + align:start position:0% +before so therefore he had a little bit + + + align:start position:0% +before so therefore he had a little bit +of luck and so he didn't get punished + + align:start position:0% +of luck and so he didn't get punished + + + align:start position:0% +of luck and so he didn't get punished +quite as severely. So, you know, it's + + align:start position:0% +quite as severely. So, you know, it's + + + align:start position:0% +quite as severely. So, you know, it's +it's it's weird fascinating stuff, but + + align:start position:0% +it's it's weird fascinating stuff, but + + + align:start position:0% +it's it's weird fascinating stuff, but +you see what's happening here is + + align:start position:0% +you see what's happening here is + + + align:start position:0% +you see what's happening here is +Butler's playing with + + align:start position:0% +Butler's playing with + + + align:start position:0% +Butler's playing with +the + + align:start position:0% +the + + + align:start position:0% +the +social kind of + + align:start position:0% +social kind of + + + align:start position:0% +social kind of +uh + + align:start position:0% +uh + + + align:start position:0% +uh +platitudes of his time and he's saying, + + align:start position:0% +platitudes of his time and he's saying, + + + align:start position:0% +platitudes of his time and he's saying, +you know, if you look underneath these, + + align:start position:0% +you know, if you look underneath these, + + + align:start position:0% +you know, if you look underneath these, +it's it's it's a lot more complex than + + align:start position:0% +it's it's it's a lot more complex than + + + align:start position:0% +it's it's it's a lot more complex than +people like to think. + + align:start position:0% +people like to think. + + + align:start position:0% +people like to think. +Um so this uh personal bereavement court + + align:start position:0% +Um so this uh personal bereavement court + + + align:start position:0% +Um so this uh personal bereavement court +uh + + align:start position:0% + + + + align:start position:0% + +um well men Victorian England has + + align:start position:0% +um well men Victorian England has + + + align:start position:0% +um well men Victorian England has +developed partially out of this this + + align:start position:0% +developed partially out of this this + + + align:start position:0% +developed partially out of this this +tradition of + + align:start position:0% +tradition of + + + align:start position:0% +tradition of +uh natural naturalism if you will + + align:start position:0% +uh natural naturalism if you will + + + align:start position:0% +uh natural naturalism if you will +uh a a set of a series of developments + + align:start position:0% +uh a a set of a series of developments + + + align:start position:0% +uh a a set of a series of developments +that uh ultimately ely collected into + + align:start position:0% +that uh ultimately ely collected into + + + align:start position:0% +that uh ultimately ely collected into +what you could say loosely was a + + align:start position:0% +what you could say loosely was a + + + align:start position:0% +what you could say loosely was a +eugenical movement. Um and in some ways + + align:start position:0% +eugenical movement. Um and in some ways + + + align:start position:0% +eugenical movement. Um and in some ways +Butler's Butler identifies + + align:start position:0% +Butler's Butler identifies + + + align:start position:0% +Butler's Butler identifies +uh the the the one of the core concepts + + align:start position:0% +uh the the the one of the core concepts + + + align:start position:0% +uh the the the one of the core concepts +of eugenic thinking which is + + align:start position:0% +of eugenic thinking which is + + + align:start position:0% +of eugenic thinking which is +what what concepts that he + + align:start position:0% +what what concepts that he + + + align:start position:0% +what what concepts that he +develops is at the core of eugenics. + + align:start position:0% + + + + align:start position:0% + +I guess that you can make a perfect by + + align:start position:0% +I guess that you can make a perfect by + + + align:start position:0% +I guess that you can make a perfect by +only allowing people who exhibit traits + + align:start position:0% +only allowing people who exhibit traits + + + align:start position:0% +only allowing people who exhibit traits +of expertise. Yeah. + + align:start position:0% +of expertise. Yeah. + + + align:start position:0% +of expertise. Yeah. +That through social policies and various + + align:start position:0% +That through social policies and various + + + align:start position:0% +That through social policies and various +kinds of uh + + align:start position:0% +kinds of uh + + + align:start position:0% +kinds of uh +top-down + + align:start position:0% +top-down + + + align:start position:0% +top-down +principles you can steer the + + align:start position:0% +principles you can steer the + + + align:start position:0% +principles you can steer the +society toward a greater average health + + align:start position:0% +society toward a greater average health + + + align:start position:0% +society toward a greater average health +and capacity. + + align:start position:0% +and capacity. + + + align:start position:0% +and capacity. +So the selection of of uh of uh of the + + align:start position:0% +So the selection of of uh of uh of the + + + align:start position:0% +So the selection of of uh of uh of the +the the best and the brightest if you + + align:start position:0% +the the best and the brightest if you + + + align:start position:0% +the the best and the brightest if you +will put it in short + + align:start position:0% +will put it in short + + + align:start position:0% +will put it in short +end. Eugenicists were + + align:start position:0% +end. Eugenicists were + + + align:start position:0% +end. Eugenicists were +concerned + + align:start position:0% +concerned + + + align:start position:0% +concerned +that contemporary + + align:start position:0% +that contemporary + + + align:start position:0% +that contemporary +societies in to the extent that + + align:start position:0% +societies in to the extent that + + + align:start position:0% +societies in to the extent that +they promulgated the principles of + + align:start position:0% +they promulgated the principles of + + + align:start position:0% +they promulgated the principles of +treatment, equal treatment of people and + + align:start position:0% +treatment, equal treatment of people and + + + align:start position:0% +treatment, equal treatment of people and +and the laws which protected people who + + align:start position:0% +and the laws which protected people who + + + align:start position:0% +and the laws which protected people who +were + + align:start position:0% +were + + + align:start position:0% +were +vulnerable were the eugenicists were + + align:start position:0% +vulnerable were the eugenicists were + + + align:start position:0% +vulnerable were the eugenicists were +concerned that this + + align:start position:0% +concerned that this + + + align:start position:0% +concerned that this +was leading toward weak weaker + + align:start position:0% +was leading toward weak weaker + + + align:start position:0% +was leading toward weak weaker +populations in the sense of + + align:start position:0% +populations in the sense of + + + align:start position:0% +populations in the sense of +Butler because you know on the sheep on + + align:start position:0% +Butler because you know on the sheep on + + + align:start position:0% +Butler because you know on the sheep on +the sheep farm you really do you you + + align:start position:0% +the sheep farm you really do you you + + + align:start position:0% +the sheep farm you really do you you +select the strongest to breed and you + + align:start position:0% +select the strongest to breed and you + + + align:start position:0% +select the strongest to breed and you +know you get a better herd and you just + + align:start position:0% +know you get a better herd and you just + + + align:start position:0% +know you get a better herd and you just +keep doing that and eventually your her + + align:start position:0% +keep doing that and eventually your her + + + align:start position:0% +keep doing that and eventually your her +gets better and better. And so + + align:start position:0% +gets better and better. And so + + + align:start position:0% +gets better and better. And so +eugenicis were + + align:start position:0% +eugenicis were + + + align:start position:0% +eugenicis were +aware that one way of thinking about + + align:start position:0% +aware that one way of thinking about + + + align:start position:0% +aware that one way of thinking about +society would be to try to find ways + + align:start position:0% +society would be to try to find ways + + + align:start position:0% +society would be to try to find ways +to use those + + align:start position:0% +to use those + + + align:start position:0% +to use those +principles. + + align:start position:0% +principles. + + + align:start position:0% +principles. +Um now this as I as I keep saying this + + align:start position:0% +Um now this as I as I keep saying this + + + align:start position:0% +Um now this as I as I keep saying this +is not what Butler is advocating. It's + + align:start position:0% +is not what Butler is advocating. It's + + + align:start position:0% +is not what Butler is advocating. It's +just he's trying to get you to think + + align:start position:0% +just he's trying to get you to think + + + align:start position:0% +just he's trying to get you to think +along these lines so that you understand + + align:start position:0% +along these lines so that you understand + + + align:start position:0% +along these lines so that you understand +some of the implications of it. + + align:start position:0% +some of the implications of it. + + + align:start position:0% +some of the implications of it. +I mean, when you see this poor man with + + align:start position:0% +I mean, when you see this poor man with + + + align:start position:0% +I mean, when you see this poor man with +pulmonary consumption being sentenced to + + align:start position:0% +pulmonary consumption being sentenced to + + + align:start position:0% +pulmonary consumption being sentenced to +hard labor, you realize how absurd it + + align:start position:0% +hard labor, you realize how absurd it + + + align:start position:0% +hard labor, you realize how absurd it +is. + + align:start position:0% +is. + + + align:start position:0% +is. +However, he's tricked you into thinking + + align:start position:0% +However, he's tricked you into thinking + + + align:start position:0% +However, he's tricked you into thinking +about the cost of + + align:start position:0% +about the cost of + + + align:start position:0% +about the cost of +that. And the cost of that is, you know, + + align:start position:0% +that. And the cost of that is, you know, + + + align:start position:0% +that. And the cost of that is, you know, +uh that, you know, there's this this + + align:start position:0% +uh that, you know, there's this this + + + align:start position:0% +uh that, you know, there's this this +other + + align:start position:0% +other + + + align:start position:0% +other +side. So there was a lot of uh there was + + align:start position:0% +side. So there was a lot of uh there was + + + align:start position:0% +side. So there was a lot of uh there was +a lot of um sort of eugenical thinking + + align:start position:0% +a lot of um sort of eugenical thinking + + + align:start position:0% +a lot of um sort of eugenical thinking +that developed in mid Victorian England. + + align:start position:0% +that developed in mid Victorian England. + + + align:start position:0% +that developed in mid Victorian England. +And Darwin was not a gen eugenicist, but + + align:start position:0% +And Darwin was not a gen eugenicist, but + + + align:start position:0% +And Darwin was not a gen eugenicist, but +his cousin Francis Golton who was pretty + + align:start position:0% +his cousin Francis Golton who was pretty + + + align:start position:0% +his cousin Francis Golton who was pretty +influential and was a a brilliant + + align:start position:0% +influential and was a a brilliant + + + align:start position:0% +influential and was a a brilliant +u uh + + align:start position:0% +u uh + + + align:start position:0% +u uh +thinker was one of the pioneers of + + align:start position:0% +thinker was one of the pioneers of + + + align:start position:0% +thinker was one of the pioneers of +eugenics and u he was one of the first + + align:start position:0% +eugenics and u he was one of the first + + + align:start position:0% +eugenics and u he was one of the first +uh Gton was a + + align:start position:0% +uh Gton was a + + + align:start position:0% +uh Gton was a +statistician. He was fascinated with uh + + align:start position:0% +statistician. He was fascinated with uh + + + align:start position:0% +statistician. He was fascinated with uh +the metrics of uh humans, understanding + + align:start position:0% +the metrics of uh humans, understanding + + + align:start position:0% +the metrics of uh humans, understanding +humans in a statistical metrical way. + + align:start position:0% +humans in a statistical metrical way. + + + align:start position:0% +humans in a statistical metrical way. +Uh the person + + align:start position:0% +Uh the person + + + align:start position:0% +Uh the person +who developed the the the system for + + align:start position:0% +who developed the the the system for + + + align:start position:0% +who developed the the the system for +fingerprinting, identifying unique + + align:start position:0% +fingerprinting, identifying unique + + + align:start position:0% +fingerprinting, identifying unique +individuals through fingerprints, he was + + align:start position:0% +individuals through fingerprints, he was + + + align:start position:0% +individuals through fingerprints, he was +really into this stuff. uh uh and he was + + align:start position:0% +really into this stuff. uh uh and he was + + + align:start position:0% +really into this stuff. uh uh and he was +quite interested in the whole idea that + + align:start position:0% +quite interested in the whole idea that + + + align:start position:0% +quite interested in the whole idea that +levels of + + align:start position:0% +levels of + + + align:start position:0% +levels of +intelligence high intelligence + + align:start position:0% +intelligence high intelligence + + + align:start position:0% +intelligence high intelligence +were transported down through the + + align:start position:0% +were transported down through the + + + align:start position:0% +were transported down through the +generations and families. + + align:start position:0% + + + + align:start position:0% + +He wrote a book called inherit + + align:start position:0% +He wrote a book called inherit + + + align:start position:0% +He wrote a book called inherit +hereditary + + align:start position:0% +hereditary + + + align:start position:0% +hereditary +genius in which uh he studied uh members + + align:start position:0% +genius in which uh he studied uh members + + + align:start position:0% +genius in which uh he studied uh members +of great science families and you know + + align:start position:0% +of great science families and you know + + + align:start position:0% +of great science families and you know +what they did what what the next + + align:start position:0% +what they did what what the next + + + align:start position:0% +what they did what what the next +generation did and he tried to develop + + align:start position:0% +generation did and he tried to develop + + + align:start position:0% +generation did and he tried to develop +this kind of + + align:start position:0% +this kind of + + + align:start position:0% +this kind of +uh this this conceptual framework for + + align:start position:0% +uh this this conceptual framework for + + + align:start position:0% +uh this this conceptual framework for +thinking + + align:start position:0% +thinking + + + align:start position:0% +thinking +about how we could + + align:start position:0% +about how we could + + + align:start position:0% +about how we could +improve how Human societies might + + align:start position:0% +improve how Human societies might + + + align:start position:0% +improve how Human societies might +improve + + align:start position:0% +improve + + + align:start position:0% +improve +their average level of intellect + + align:start position:0% +their average level of intellect + + + align:start position:0% +their average level of intellect +and + + align:start position:0% +and + + + align:start position:0% +and +performance and the other side of it + + align:start position:0% +performance and the other side of it + + + align:start position:0% +performance and the other side of it +resist the uh the process of sort of I + + align:start position:0% +resist the uh the process of sort of I + + + align:start position:0% +resist the uh the process of sort of I +mean we call it a gene pool now but he + + align:start position:0% +mean we call it a gene pool now but he + + + align:start position:0% +mean we call it a gene pool now but he +didn't have those words before he was + + align:start position:0% +didn't have those words before he was + + + align:start position:0% +didn't have those words before he was +but he knew basically that uh there were + + align:start position:0% +but he knew basically that uh there were + + + align:start position:0% +but he knew basically that uh there were +principles of + + align:start position:0% +principles of + + + align:start position:0% +principles of +inheritance. So, uh this is what he was + + align:start position:0% +inheritance. So, uh this is what he was + + + align:start position:0% +inheritance. So, uh this is what he was +he was uh he was interested in doing. + + align:start position:0% +he was uh he was interested in doing. + + + align:start position:0% +he was uh he was interested in doing. +Um + + align:start position:0% +Um + + + align:start position:0% +Um +Darwin I don't myself consider Darwin a + + align:start position:0% +Darwin I don't myself consider Darwin a + + + align:start position:0% +Darwin I don't myself consider Darwin a +eugenicist of any type but he does say + + align:start position:0% +eugenicist of any type but he does say + + + align:start position:0% +eugenicist of any type but he does say +in his book that you know people who are + + align:start position:0% +in his book that you know people who are + + + align:start position:0% +in his book that you know people who are +poor should refrain from marrying and + + align:start position:0% +poor should refrain from marrying and + + + align:start position:0% +poor should refrain from marrying and +having children stuff like that. uh you + + align:start position:0% +having children stuff like that. uh you + + + align:start position:0% +having children stuff like that. uh you +know at some level it's just good advice + + align:start position:0% +know at some level it's just good advice + + + align:start position:0% +know at some level it's just good advice +you know can't + + align:start position:0% +you know can't + + + align:start position:0% +you know can't +afford try to try to work within your + + align:start position:0% +afford try to try to work within your + + + align:start position:0% +afford try to try to work within your +means so uh but uh his his cousin Gton + + align:start position:0% +means so uh but uh his his cousin Gton + + + align:start position:0% +means so uh but uh his his cousin Gton +was much more into you know + + align:start position:0% +was much more into you know + + + align:start position:0% +was much more into you know +understanding some of these principles + + align:start position:0% +understanding some of these principles + + + align:start position:0% +understanding some of these principles +and the a society developed in England + + align:start position:0% +and the a society developed in England + + + align:start position:0% +and the a society developed in England +eugenical society of of of + + align:start position:0% +eugenical society of of of + + + align:start position:0% +eugenical society of of of +London we're going to read a work later + + align:start position:0% +London we're going to read a work later + + + align:start position:0% +London we're going to read a work later +in the term + + align:start position:0% +in the term + + + align:start position:0% +in the term +uh by Thomas Henry Huxley which attacks + + align:start position:0% +uh by Thomas Henry Huxley which attacks + + + align:start position:0% +uh by Thomas Henry Huxley which attacks +this whole movement of eugenical + + align:start position:0% +this whole movement of eugenical + + + align:start position:0% +this whole movement of eugenical +thinking but it was quite strong in + + align:start position:0% +thinking but it was quite strong in + + + align:start position:0% +thinking but it was quite strong in +England and you know people like to say + + align:start position:0% +England and you know people like to say + + + align:start position:0% +England and you know people like to say +oh the Germans came up with eugenics and + + align:start position:0% +oh the Germans came up with eugenics and + + + align:start position:0% +oh the Germans came up with eugenics and +they did terrible things in the second + + align:start position:0% +they did terrible things in the second + + + align:start position:0% +they did terrible things in the second +world war but you know eugenics as a set + + align:start position:0% +world war but you know eugenics as a set + + + align:start position:0% +world war but you know eugenics as a set +of ideas was around long before the + + align:start position:0% +of ideas was around long before the + + + align:start position:0% +of ideas was around long before the +third reich I can tell you that uh and + + align:start position:0% +third reich I can tell you that uh and + + + align:start position:0% +third reich I can tell you that uh and +it was uh there was a movement in + + align:start position:0% +it was uh there was a movement in + + + align:start position:0% +it was uh there was a movement in +America I mean you know there's there's + + align:start position:0% +America I mean you know there's there's + + + align:start position:0% +America I mean you know there's there's +a whole history of this this type of + + align:start position:0% +a whole history of this this type of + + + align:start position:0% +a whole history of this this type of +thinking and it it emerged + + align:start position:0% +thinking and it it emerged + + + align:start position:0% +thinking and it it emerged +out of the kind of + + align:start position:0% +out of the kind of + + + align:start position:0% +out of the kind of +naturalism that Charles Darwin was part + + align:start position:0% +naturalism that Charles Darwin was part + + + align:start position:0% +naturalism that Charles Darwin was part +of. But it just indicates that you know + + align:start position:0% +of. But it just indicates that you know + + + align:start position:0% +of. But it just indicates that you know +ideas can be used in a variety of ways. + + align:start position:0% +ideas can be used in a variety of ways. + + + align:start position:0% +ideas can be used in a variety of ways. +Darwin as I said did not use them this + + align:start position:0% +Darwin as I said did not use them this + + + align:start position:0% +Darwin as I said did not use them this +way. He was not a + + align:start position:0% +way. He was not a + + + align:start position:0% +way. He was not a +eugenicist. Uh I mean there may be + + align:start position:0% +eugenicist. Uh I mean there may be + + + align:start position:0% +eugenicist. Uh I mean there may be +anybody who wants to argue that but I + + align:start position:0% +anybody who wants to argue that but I + + + align:start position:0% +anybody who wants to argue that but I +certainly don't but Gton definitely was + + align:start position:0% +certainly don't but Gton definitely was + + + align:start position:0% +certainly don't but Gton definitely was +yeah how does social Darwinism relate to + + align:start position:0% +yeah how does social Darwinism relate to + + + align:start position:0% +yeah how does social Darwinism relate to +eugenics uh it's an expression eugenics + + align:start position:0% +eugenics uh it's an expression eugenics + + + align:start position:0% +eugenics uh it's an expression eugenics +social darism is and eugenics are the + + align:start position:0% +social darism is and eugenics are the + + + align:start position:0% +social darism is and eugenics are the +same yeah okay so so we'll we'll see + + align:start position:0% +same yeah okay so so we'll we'll see + + + align:start position:0% +same yeah okay so so we'll we'll see +more of this it's it's just a it's a + + align:start position:0% +more of this it's it's just a it's a + + + align:start position:0% +more of this it's it's just a it's a +it's a side of this kind of thinking + + align:start position:0% +it's a side of this kind of thinking + + + align:start position:0% +it's a side of this kind of thinking +that uh needs to be + + align:start position:0% +that uh needs to be + + + align:start position:0% +that uh needs to be +understood and addressed and Butler here + + align:start position:0% +understood and addressed and Butler here + + + align:start position:0% +understood and addressed and Butler here +is one of the first harbinger of you + + align:start position:0% +is one of the first harbinger of you + + + align:start position:0% +is one of the first harbinger of you +know this whole wave of + + align:start position:0% +know this whole wave of + + + align:start position:0% +know this whole wave of +thinking + + align:start position:0% +thinking + + + align:start position:0% +thinking +butler there's nothing in his work that + + align:start position:0% +butler there's nothing in his work that + + + align:start position:0% +butler there's nothing in his work that +suggests that he was a eugenicist but in + + align:start position:0% +suggests that he was a eugenicist but in + + + align:start position:0% +suggests that he was a eugenicist but in +u in his um arowan he's sort of + + align:start position:0% +u in his um arowan he's sort of + + + align:start position:0% +u in his um arowan he's sort of +exploring this territory and opening + + align:start position:0% +exploring this territory and opening + + + align:start position:0% +exploring this territory and opening +them up and saying you know here are + + align:start position:0% +them up and saying you know here are + + + align:start position:0% +them up and saying you know here are +ways in which you can think here's here + + align:start position:0% +ways in which you can think here's here + + + align:start position:0% +ways in which you can think here's here +are ways in which you can use Darwinism + + align:start position:0% +are ways in which you can use Darwinism + + + align:start position:0% +are ways in which you can use Darwinism +to think about society + + align:start position:0% +to think about society + + + align:start position:0% +to think about society +be aware. Just a couple of things before + + align:start position:0% +be aware. Just a couple of things before + + + align:start position:0% +be aware. Just a couple of things before +we leave. Uh what about the religious + + align:start position:0% +we leave. Uh what about the religious + + + align:start position:0% +we leave. Uh what about the religious +establishment? What did anybody get + + align:start position:0% +establishment? What did anybody get + + + align:start position:0% +establishment? What did anybody get +through the musical bank + + align:start position:0% + + + + align:start position:0% + +section? Religion in among the Aeronians + + align:start position:0% +section? Religion in among the Aeronians + + + align:start position:0% +section? Religion in among the Aeronians +is pretty much just a empty + + align:start position:0% +is pretty much just a empty + + + align:start position:0% +is pretty much just a empty +uh uh it's it's it's sort of an empty + + align:start position:0% +uh uh it's it's it's sort of an empty + + + align:start position:0% +uh uh it's it's it's sort of an empty +ceremony. People go to these places and + + align:start position:0% +ceremony. People go to these places and + + + align:start position:0% +ceremony. People go to these places and +they + + align:start position:0% +they + + + align:start position:0% +they +uh show a certain kind of uh face if you + + align:start position:0% +uh show a certain kind of uh face if you + + + align:start position:0% +uh show a certain kind of uh face if you +will but fundamentally they don't really + + align:start position:0% +will but fundamentally they don't really + + + align:start position:0% +will but fundamentally they don't really +have much uh conviction that anything + + align:start position:0% +have much uh conviction that anything + + + align:start position:0% +have much uh conviction that anything +important is going to happen in the + + align:start position:0% +important is going to happen in the + + + align:start position:0% +important is going to happen in the +so-called now the musical banks are + + align:start position:0% +so-called now the musical banks are + + + align:start position:0% +so-called now the musical banks are +his the Awanians uh what what what the + + align:start position:0% +his the Awanians uh what what what the + + + align:start position:0% +his the Awanians uh what what what the +uh narrator here calls the Awanian + + align:start position:0% +uh narrator here calls the Awanian + + + align:start position:0% +uh narrator here calls the Awanian +places of uh + + align:start position:0% +places of uh + + + align:start position:0% +places of uh +worship and u these are banks that uh + + align:start position:0% +worship and u these are banks that uh + + + align:start position:0% +worship and u these are banks that uh +these are basically places where people + + align:start position:0% +these are basically places where people + + + align:start position:0% +these are basically places where people +go to be seen and they want to be + + align:start position:0% +go to be seen and they want to be + + + align:start position:0% +go to be seen and they want to be +associated with but fundamentally they + + align:start position:0% +associated with but fundamentally they + + + align:start position:0% +associated with but fundamentally they +don't pay any attention to them. This is + + align:start position:0% +don't pay any attention to them. This is + + + align:start position:0% +don't pay any attention to them. This is +pretty much Butler's view of of + + align:start position:0% +pretty much Butler's view of of + + + align:start position:0% +pretty much Butler's view of of +organized religion of his time. Butler's + + align:start position:0% +organized religion of his time. Butler's + + + align:start position:0% +organized religion of his time. Butler's +father was a cleric. This this is + + align:start position:0% +father was a cleric. This this is + + + align:start position:0% +father was a cleric. This this is +Butler's father's church here in uh in + + align:start position:0% +Butler's father's church here in uh in + + + align:start position:0% +Butler's father's church here in uh in +Langar uh England. And uh it's actually + + align:start position:0% +Langar uh England. And uh it's actually + + + align:start position:0% +Langar uh England. And uh it's actually +quite an interesting church. I went + + align:start position:0% +quite an interesting church. I went + + + align:start position:0% +quite an interesting church. I went +there to visit it once. Uh it sits up on + + align:start position:0% +there to visit it once. Uh it sits up on + + + align:start position:0% +there to visit it once. Uh it sits up on +this sort of null. His father renovated + + align:start position:0% +this sort of null. His father renovated + + + align:start position:0% +this sort of null. His father renovated +it. And apparently most people think he + + align:start position:0% +it. And apparently most people think he + + + align:start position:0% +it. And apparently most people think he +remodeled it. He he took his father took + + align:start position:0% +remodeled it. He he took his father took + + + align:start position:0% +remodeled it. He he took his father took +the the distinctive features of of of + + align:start position:0% +the the distinctive features of of of + + + align:start position:0% +the the distinctive features of of of +the church and kind + + align:start position:0% +the church and kind + + + align:start position:0% +the church and kind +of okay + + align:start position:0% +of okay + + + align:start position:0% +of okay +so what we're uh so this world is a + + align:start position:0% +so what we're uh so this world is a + + + align:start position:0% +so what we're uh so this world is a +world of biological juosition with + + align:start position:0% +world of biological juosition with + + + align:start position:0% +world of biological juosition with +social and uh there's a kind of a humor + + align:start position:0% +social and uh there's a kind of a humor + + + align:start position:0% +social and uh there's a kind of a humor +to it a satire to it butler's making use + + align:start position:0% +to it a satire to it butler's making use + + + align:start position:0% +to it a satire to it butler's making use +of this and + + align:start position:0% +of this and + + + align:start position:0% +of this and +uh I've given you a little dancing + + align:start position:0% +uh I've given you a little dancing + + + align:start position:0% +uh I've given you a little dancing +hippos uh clip here from Fantasia + + align:start position:0% +hippos uh clip here from Fantasia + + + align:start position:0% +hippos uh clip here from Fantasia +And part of the humor of that is seeing + + align:start position:0% +And part of the humor of that is seeing + + + align:start position:0% +And part of the humor of that is seeing +something natural do something + + align:start position:0% +something natural do something + + + align:start position:0% +something natural do something +unnatural. There there there's a kind of + + align:start position:0% +unnatural. There there there's a kind of + + + align:start position:0% +unnatural. There there there's a kind of +humor to it. And that's part of the + + align:start position:0% +humor to it. And that's part of the + + + align:start position:0% +humor to it. And that's part of the +source of the humor in in Arrowan. \ No newline at end of file diff --git a/vN5Yn-niTXE.txt b/vN5Yn-niTXE.txt new file mode 100644 index 0000000000000000000000000000000000000000..67f2579030b7b59d9b361fa0e973875b9b6d8b59 --- /dev/null +++ b/vN5Yn-niTXE.txt @@ -0,0 +1,11635 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% + + + + align:start position:0% + +all right so let's get started so today + + align:start position:0% +all right so let's get started so today + + + align:start position:0% +all right so let's get started so today +or last lecture we talked about + + align:start position:0% +or last lecture we talked about + + + align:start position:0% +or last lecture we talked about +different device parameters mainly our + + align:start position:0% +different device parameters mainly our + + + align:start position:0% +different device parameters mainly our +series resistance and shunt resistance + + align:start position:0% +series resistance and shunt resistance + + + align:start position:0% +series resistance and shunt resistance +and how that affects our efficiencies + + align:start position:0% +and how that affects our efficiencies + + + align:start position:0% +and how that affects our efficiencies +today we're going to talk a lot about + + align:start position:0% +today we're going to talk a lot about + + + align:start position:0% +today we're going to talk a lot about +different material properties and how + + align:start position:0% +different material properties and how + + + align:start position:0% +different material properties and how +they affect certain device + + align:start position:0% +they affect certain device + + + align:start position:0% +they affect certain device +characteristics and mainly just affect + + align:start position:0% +characteristics and mainly just affect + + + align:start position:0% +characteristics and mainly just affect +our output efficiency so we've been + + align:start position:0% +our output efficiency so we've been + + + align:start position:0% +our output efficiency so we've been +talking a lot about the fundamentals I'm + + align:start position:0% +talking a lot about the fundamentals I'm + + + align:start position:0% +talking a lot about the fundamentals I'm +sure you guys are loving this right now + + align:start position:0% +sure you guys are loving this right now + + + align:start position:0% +sure you guys are loving this right now +so we're gonna complete this in probably + + align:start position:0% +so we're gonna complete this in probably + + + align:start position:0% +so we're gonna complete this in probably +the next three lectures and then move on + + align:start position:0% +the next three lectures and then move on + + + align:start position:0% +the next three lectures and then move on +to a lot of the kind of cross-cutting + + align:start position:0% +to a lot of the kind of cross-cutting + + + align:start position:0% +to a lot of the kind of cross-cutting +themes in PV some advanced concepts you + + align:start position:0% +themes in PV some advanced concepts you + + + align:start position:0% +themes in PV some advanced concepts you +know different device architectures and + + align:start position:0% +know different device architectures and + + + align:start position:0% +know different device architectures and +that kind of thing and so that is coming + + align:start position:0% +that kind of thing and so that is coming + + + align:start position:0% +that kind of thing and so that is coming +in the future but we're still doing + + align:start position:0% +in the future but we're still doing + + + align:start position:0% +in the future but we're still doing +fundamentals today and so I know you're + + align:start position:0% +fundamentals today and so I know you're + + + align:start position:0% +fundamentals today and so I know you're +probably all aware of this equation and + + align:start position:0% +probably all aware of this equation and + + + align:start position:0% +probably all aware of this equation and +again this is kind of the progress we've + + align:start position:0% +again this is kind of the progress we've + + + align:start position:0% +again this is kind of the progress we've +made so we're almost all the way through + + align:start position:0% +made so we're almost all the way through + + + align:start position:0% +made so we're almost all the way through +explaining basic device physics and + + align:start position:0% +explaining basic device physics and + + + align:start position:0% +explaining basic device physics and +basic semiconductor physics too so you + + align:start position:0% +basic semiconductor physics too so you + + + align:start position:0% +basic semiconductor physics too so you +can understand simple devices and it's + + align:start position:0% +can understand simple devices and it's + + + align:start position:0% +can understand simple devices and it's +always important to remember that your + + align:start position:0% +always important to remember that your + + + align:start position:0% +always important to remember that your +device is like a leaky bucket and you're + + align:start position:0% +device is like a leaky bucket and you're + + + align:start position:0% +device is like a leaky bucket and you're +limited by the largest hole in that + + align:start position:0% +limited by the largest hole in that + + + align:start position:0% +limited by the largest hole in that +bucket so the weakest aspect of your + + align:start position:0% +bucket so the weakest aspect of your + + + align:start position:0% +bucket so the weakest aspect of your +solar cell is really what's going to + + align:start position:0% +solar cell is really what's going to + + + align:start position:0% +solar cell is really what's going to +limit your device performance and + + align:start position:0% +limit your device performance and + + + align:start position:0% +limit your device performance and +especially if any of you here are trying + + align:start position:0% +especially if any of you here are trying + + + align:start position:0% +especially if any of you here are trying +to make devices it's really important to + + align:start position:0% +to make devices it's really important to + + + align:start position:0% +to make devices it's really important to +think about all of these things when + + align:start position:0% +think about all of these things when + + + align:start position:0% +think about all of these things when +building it and this is very difficult + + align:start position:0% +building it and this is very difficult + + + align:start position:0% +building it and this is very difficult +to do I can certainly tell you that okay + + align:start position:0% +to do I can certainly tell you that okay + + + align:start position:0% +to do I can certainly tell you that okay +so I kind of like this slide what this + + align:start position:0% +so I kind of like this slide what this + + + align:start position:0% +so I kind of like this slide what this +is is saying what's the thing we care + + align:start position:0% +is is saying what's the thing we care + + + align:start position:0% +is is saying what's the thing we care +about most in our solar cells well as + + align:start position:0% +about most in our solar cells well as + + + align:start position:0% +about most in our solar cells well as +scientists other than dollars per watt + + align:start position:0% +scientists other than dollars per watt + + + align:start position:0% +scientists other than dollars per watt +we want to maximize our efficiency for a + + align:start position:0% +we want to maximize our efficiency for a + + + align:start position:0% +we want to maximize our efficiency for a +certain price and our efficiency there + + align:start position:0% +certain price and our efficiency there + + + align:start position:0% +certain price and our efficiency there +are several parameters that go into it + + align:start position:0% +are several parameters that go into it + + + align:start position:0% +are several parameters that go into it +again we talked about our JSC our + + align:start position:0% +again we talked about our JSC our + + + align:start position:0% +again we talked about our JSC our +short-circuit current our open circuit + + align:start position:0% +short-circuit current our open circuit + + + align:start position:0% +short-circuit current our open circuit +voltage and our fill factor and that + + align:start position:0% +voltage and our fill factor and that + + + align:start position:0% +voltage and our fill factor and that +gives us our output energy or output + + align:start position:0% +gives us our output energy or output + + + align:start position:0% +gives us our output energy or output +power and we divide that by the input + + align:start position:0% +power and we divide that by the input + + + align:start position:0% +power and we divide that by the input +power which is the solar insolation now + + align:start position:0% +power which is the solar insolation now + + + align:start position:0% +power which is the solar insolation now +we can split up that again in the open + + align:start position:0% +we can split up that again in the open + + + align:start position:0% +we can split up that again in the open +circuit voltage short circuit current + + align:start position:0% +circuit voltage short circuit current + + + align:start position:0% +circuit voltage short circuit current +and fill factor we talked a little bit + + align:start position:0% +and fill factor we talked a little bit + + + align:start position:0% +and fill factor we talked a little bit +last lecture about fill factor and how + + align:start position:0% +last lecture about fill factor and how + + + align:start position:0% +last lecture about fill factor and how +that's influenced by + + align:start position:0% +that's influenced by + + + align:start position:0% +that's influenced by +different resistive losses in our solar + + align:start position:0% +different resistive losses in our solar + + + align:start position:0% +different resistive losses in our solar +cell today we're gonna mainly be focused + + align:start position:0% +cell today we're gonna mainly be focused + + + align:start position:0% +cell today we're gonna mainly be focused +on short circuit current and things like + + align:start position:0% +on short circuit current and things like + + + align:start position:0% +on short circuit current and things like +internal quantum efficiency which are + + align:start position:0% +internal quantum efficiency which are + + + align:start position:0% +internal quantum efficiency which are +highly affected by our diffusion length + + align:start position:0% +highly affected by our diffusion length + + + align:start position:0% +highly affected by our diffusion length +and the diffusion length is often + + align:start position:0% +and the diffusion length is often + + + align:start position:0% +and the diffusion length is often +limited by certain defects in our + + align:start position:0% +limited by certain defects in our + + + align:start position:0% +limited by certain defects in our +materials and we're gonna get into why + + align:start position:0% +materials and we're gonna get into why + + + align:start position:0% +materials and we're gonna get into why +that is and to a certain extent we'll + + align:start position:0% +that is and to a certain extent we'll + + + align:start position:0% +that is and to a certain extent we'll +talk about open circuit voltage because + + align:start position:0% +talk about open circuit voltage because + + + align:start position:0% +talk about open circuit voltage because +your JSC can really has a large effect + + align:start position:0% +your JSC can really has a large effect + + + align:start position:0% +your JSC can really has a large effect +on your open circuit voltage so what + + align:start position:0% +on your open circuit voltage so what + + + align:start position:0% +on your open circuit voltage so what +we're gonna learn today is what is + + align:start position:0% +we're gonna learn today is what is + + + align:start position:0% +we're gonna learn today is what is +minority carrier diffusion length it was + + align:start position:0% +minority carrier diffusion length it was + + + align:start position:0% +minority carrier diffusion length it was +in the homework hopefully you guys have + + align:start position:0% +in the homework hopefully you guys have + + + align:start position:0% +in the homework hopefully you guys have +some idea coming to lecture but today + + align:start position:0% +some idea coming to lecture but today + + + align:start position:0% +some idea coming to lecture but today +we're gonna talk about a little more in + + align:start position:0% +we're gonna talk about a little more in + + + align:start position:0% +we're gonna talk about a little more in +depth and why it's important and how + + align:start position:0% +depth and why it's important and how + + + align:start position:0% +depth and why it's important and how +it's affected what are the parameters + + align:start position:0% +it's affected what are the parameters + + + align:start position:0% +it's affected what are the parameters +that determine it so mainly diffusivity + + align:start position:0% +that determine it so mainly diffusivity + + + align:start position:0% +that determine it so mainly diffusivity +and lifetime we're gonna describe how + + align:start position:0% +and lifetime we're gonna describe how + + + align:start position:0% +and lifetime we're gonna describe how +it's actually measured in a solar cell + + align:start position:0% +it's actually measured in a solar cell + + + align:start position:0% +it's actually measured in a solar cell +there's actually really cool measurement + + align:start position:0% +there's actually really cool measurement + + + align:start position:0% +there's actually really cool measurement +and we actually have the capabilities in + + align:start position:0% +and we actually have the capabilities in + + + align:start position:0% +and we actually have the capabilities in +our lab and possibly some of you when + + align:start position:0% +our lab and possibly some of you when + + + align:start position:0% +our lab and possibly some of you when +you're making cells will be able to do + + align:start position:0% +you're making cells will be able to do + + + align:start position:0% +you're making cells will be able to do +that measurement we're also going to + + align:start position:0% +that measurement we're also going to + + + align:start position:0% +that measurement we're also going to +look at some of the things that live at + + align:start position:0% +look at some of the things that live at + + + align:start position:0% +look at some of the things that live at +lifetime to some of the basic + + align:start position:0% +lifetime to some of the basic + + + align:start position:0% +lifetime to some of the basic +recombination mechanisms also look at + + align:start position:0% +recombination mechanisms also look at + + + align:start position:0% +recombination mechanisms also look at +how your excess carrier concentration + + align:start position:0% +how your excess carrier concentration + + + align:start position:0% +how your excess carrier concentration +changes as a function of lifetime and + + align:start position:0% +changes as a function of lifetime and + + + align:start position:0% +changes as a function of lifetime and +generation light and then also talk + + align:start position:0% +generation light and then also talk + + + align:start position:0% +generation light and then also talk +about the last material parameter which + + align:start position:0% +about the last material parameter which + + + align:start position:0% +about the last material parameter which +is mobility which discusses kind of how + + align:start position:0% +is mobility which discusses kind of how + + + align:start position:0% +is mobility which discusses kind of how +well these excited charges can move + + align:start position:0% +well these excited charges can move + + + align:start position:0% +well these excited charges can move +around within your material so without + + align:start position:0% +around within your material so without + + + align:start position:0% +around within your material so without +further ado your minority carrier + + align:start position:0% +further ado your minority carrier + + + align:start position:0% +further ado your minority carrier +diffusion length definition is really + + align:start position:0% +diffusion length definition is really + + + align:start position:0% +diffusion length definition is really +simple if you generate let's say a + + align:start position:0% +simple if you generate let's say a + + + align:start position:0% +simple if you generate let's say a +photon comes and hits a silicon atom and + + align:start position:0% +photon comes and hits a silicon atom and + + + align:start position:0% +photon comes and hits a silicon atom and +generates + + align:start position:0% +generates + + + align:start position:0% +generates +an electron pair over here how far or + + align:start position:0% +an electron pair over here how far or + + + align:start position:0% +an electron pair over here how far or +how much volume can it explore that + + align:start position:0% +how much volume can it explore that + + + align:start position:0% +how much volume can it explore that +volume it can explore is described by + + align:start position:0% +volume it can explore is described by + + + align:start position:0% +volume it can explore is described by +some characteristic radius and that + + align:start position:0% +some characteristic radius and that + + + align:start position:0% +some characteristic radius and that +radius is known as the diffusion length + + align:start position:0% +radius is known as the diffusion length + + + align:start position:0% +radius is known as the diffusion length +and it's really important to solar cells + + align:start position:0% +and it's really important to solar cells + + + align:start position:0% +and it's really important to solar cells +because when you think about these + + align:start position:0% +because when you think about these + + + align:start position:0% +because when you think about these +carriers that you're generating when + + align:start position:0% +carriers that you're generating when + + + align:start position:0% +carriers that you're generating when +they if they can only explore a very + + align:start position:0% +they if they can only explore a very + + + align:start position:0% +they if they can only explore a very +short area they're not going to make it + + align:start position:0% +short area they're not going to make it + + + align:start position:0% +short area they're not going to make it +this is a very good solar cell so the + + align:start position:0% +this is a very good solar cell so the + + + align:start position:0% +this is a very good solar cell so the +diffusion length is really long and all + + align:start position:0% +diffusion length is really long and all + + + align:start position:0% +diffusion length is really long and all +these carriers generated there we'll be + + align:start position:0% +these carriers generated there we'll be + + + align:start position:0% +these carriers generated there we'll be +able to make our Junction so again just + + align:start position:0% +able to make our Junction so again just + + + align:start position:0% +able to make our Junction so again just +so we're familiar this is our base and a + + align:start position:0% +so we're familiar this is our base and a + + + align:start position:0% +so we're familiar this is our base and a +top we have our our emitter so our the + + align:start position:0% +top we have our our emitter so our the + + + align:start position:0% +top we have our our emitter so our the +junction would be at this line right + + align:start position:0% +junction would be at this line right + + + align:start position:0% +junction would be at this line right +here on that plane + + align:start position:0% +here on that plane + + + align:start position:0% +here on that plane +if we have a really bad solar cell so + + align:start position:0% +if we have a really bad solar cell so + + + align:start position:0% +if we have a really bad solar cell so +let's say a lot of defects present a lot + + align:start position:0% +let's say a lot of defects present a lot + + + align:start position:0% +let's say a lot of defects present a lot +of areas for these excited carriers to + + align:start position:0% +of areas for these excited carriers to + + + align:start position:0% +of areas for these excited carriers to +recombine they won't make it to the + + align:start position:0% +recombine they won't make it to the + + + align:start position:0% +recombine they won't make it to the +junction they'll have a very short + + align:start position:0% +junction they'll have a very short + + + align:start position:0% +junction they'll have a very short +diffusion length and as a result your + + align:start position:0% +diffusion length and as a result your + + + align:start position:0% +diffusion length and as a result your +short-circuit current and your vo si + + align:start position:0% +short-circuit current and your vo si + + + align:start position:0% +short-circuit current and your vo si +will suffer dramatically so it's really + + align:start position:0% +will suffer dramatically so it's really + + + align:start position:0% +will suffer dramatically so it's really +important to get good crystal quality + + align:start position:0% +important to get good crystal quality + + + align:start position:0% +important to get good crystal quality +and good material quality but up to a + + align:start position:0% +and good material quality but up to a + + + align:start position:0% +and good material quality but up to a +certain point right there's kind of + + align:start position:0% +certain point right there's kind of + + + align:start position:0% +certain point right there's kind of +diminishing returns as you go to higher + + align:start position:0% +diminishing returns as you go to higher + + + align:start position:0% +diminishing returns as you go to higher +and higher qualities and we'll talk + + align:start position:0% +and higher qualities and we'll talk + + + align:start position:0% +and higher qualities and we'll talk +about that in a second so if we assume + + align:start position:0% + + + + align:start position:0% + +what this is showing is how our short + + align:start position:0% +what this is showing is how our short + + + align:start position:0% +what this is showing is how our short +circuit current scales with our + + align:start position:0% +circuit current scales with our + + + align:start position:0% +circuit current scales with our +diffusion length so we have some + + align:start position:0% +diffusion length so we have some + + + align:start position:0% +diffusion length so we have some +something called the generation rate and + + align:start position:0% +something called the generation rate and + + + align:start position:0% +something called the generation rate and +this is often proportional to the photon + + align:start position:0% +this is often proportional to the photon + + + align:start position:0% +this is often proportional to the photon +flux on your material so the number of + + align:start position:0% +flux on your material so the number of + + + align:start position:0% +flux on your material so the number of +photons hitting your solar cell and this + + align:start position:0% +photons hitting your solar cell and this + + + align:start position:0% +photons hitting your solar cell and this +generation rate is something the number + + align:start position:0% +generation rate is something the number + + + align:start position:0% +generation rate is something the number +of carriers produced a second in some + + align:start position:0% +of carriers produced a second in some + + + align:start position:0% +of carriers produced a second in some +given volume so it's a volumetric term + + align:start position:0% +given volume so it's a volumetric term + + + align:start position:0% +given volume so it's a volumetric term +and if we assume that everything within + + align:start position:0% +and if we assume that everything within + + + align:start position:0% +and if we assume that everything within +one diffusion length of our Junction + + align:start position:0% +one diffusion length of our Junction + + + align:start position:0% +one diffusion length of our Junction +gets collected that'll all be counted as + + align:start position:0% +gets collected that'll all be counted as + + + align:start position:0% +gets collected that'll all be counted as +short-circuit current so you basically + + align:start position:0% +short-circuit current so you basically + + + align:start position:0% +short-circuit current so you basically +your JSC has this kind of linear + + align:start position:0% +your JSC has this kind of linear + + + align:start position:0% +your JSC has this kind of linear +dependence on your diffusion length but + + align:start position:0% +dependence on your diffusion length but + + + align:start position:0% +dependence on your diffusion length but +that's only true up to a certain point + + align:start position:0% +that's only true up to a certain point + + + align:start position:0% +that's only true up to a certain point +right so if for example if we have a + + align:start position:0% +right so if for example if we have a + + + align:start position:0% +right so if for example if we have a +diffusion length that's much longer than + + align:start position:0% +diffusion length that's much longer than + + + align:start position:0% +diffusion length that's much longer than +the device thickness it's really not + + align:start position:0% +the device thickness it's really not + + + align:start position:0% +the device thickness it's really not +going to get again diminishing returns + + align:start position:0% +going to get again diminishing returns + + + align:start position:0% +going to get again diminishing returns +as you go to longer and longer diffusion + + align:start position:0% +as you go to longer and longer diffusion + + + align:start position:0% +as you go to longer and longer diffusion +lengths so this is a calculation I did + + align:start position:0% +lengths so this is a calculation I did + + + align:start position:0% +lengths so this is a calculation I did +using a 1d simulation program called PC + + align:start position:0% +using a 1d simulation program called PC + + + align:start position:0% +using a 1d simulation program called PC +1d which if you want to play around with + + align:start position:0% +1d which if you want to play around with + + + align:start position:0% +1d which if you want to play around with +it's free + + align:start position:0% +it's free + + + align:start position:0% +it's free +it's a lot of fun to use actually and + + align:start position:0% +it's a lot of fun to use actually and + + + align:start position:0% +it's a lot of fun to use actually and +you can put in things like lifetimes and + + align:start position:0% +you can put in things like lifetimes and + + + align:start position:0% +you can put in things like lifetimes and +I very basically the lifetime which + + align:start position:0% +I very basically the lifetime which + + + align:start position:0% +I very basically the lifetime which +we'll get to in a second how that + + align:start position:0% +we'll get to in a second how that + + + align:start position:0% +we'll get to in a second how that +changes the diffusion length and you can + + align:start position:0% +changes the diffusion length and you can + + + align:start position:0% +changes the diffusion length and you can +see that there actually is a linear + + align:start position:0% +see that there actually is a linear + + + align:start position:0% +see that there actually is a linear +relation until the diffusion length is + + align:start position:0% +relation until the diffusion length is + + + align:start position:0% +relation until the diffusion length is +about on the order of 300 microns which + + align:start position:0% +about on the order of 300 microns which + + + align:start position:0% +about on the order of 300 microns which +is the device thickness so you can see + + align:start position:0% +is the device thickness so you can see + + + align:start position:0% +is the device thickness so you can see +this kind of trailing off and become sub + + align:start position:0% +this kind of trailing off and become sub + + + align:start position:0% +this kind of trailing off and become sub +linear in its response yeah + + align:start position:0% + + + + align:start position:0% + +so let's let's let's think about it one + + align:start position:0% +so let's let's let's think about it one + + + align:start position:0% +so let's let's let's think about it one +step back why do we care about minority + + align:start position:0% +step back why do we care about minority + + + align:start position:0% +step back why do we care about minority +carriers right so if let's say you + + align:start position:0% +carriers right so if let's say you + + + align:start position:0% +carriers right so if let's say you +generate an electron hole pair and + + align:start position:0% +generate an electron hole pair and + + + align:start position:0% +generate an electron hole pair and +n-type material the hole wants to move + + align:start position:0% +n-type material the hole wants to move + + + align:start position:0% +n-type material the hole wants to move +to the p-type side right and it's the + + align:start position:0% +to the p-type side right and it's the + + + align:start position:0% +to the p-type side right and it's the +electric field will actually repel and + + align:start position:0% +electric field will actually repel and + + + align:start position:0% +electric field will actually repel and +keep it on the electron on the on the on + + align:start position:0% +keep it on the electron on the on the on + + + align:start position:0% +keep it on the electron on the on the on +the n-type side so it's your minority + + align:start position:0% +the n-type side so it's your minority + + + align:start position:0% +the n-type side so it's your minority +carriers that matter in terms of the + + align:start position:0% +carriers that matter in terms of the + + + align:start position:0% +carriers that matter in terms of the +separation and we'll talk about that + + align:start position:0% +separation and we'll talk about that + + + align:start position:0% +separation and we'll talk about that +again if that's still fuzzy in people's + + align:start position:0% +again if that's still fuzzy in people's + + + align:start position:0% +again if that's still fuzzy in people's +heads and so what carrier what matters + + align:start position:0% +heads and so what carrier what matters + + + align:start position:0% +heads and so what carrier what matters +in terms of you talking about deriving + + align:start position:0% +in terms of you talking about deriving + + + align:start position:0% +in terms of you talking about deriving +the ideal diode equation well yeah but + + align:start position:0% +the ideal diode equation well yeah but + + + align:start position:0% +the ideal diode equation well yeah but +in order to be separated which is the + + align:start position:0% +in order to be separated which is the + + + align:start position:0% +in order to be separated which is the +first part that we care about we it + + align:start position:0% +first part that we care about we it + + + align:start position:0% +first part that we care about we it +matters that it's reached the junction + + align:start position:0% +matters that it's reached the junction + + + align:start position:0% +matters that it's reached the junction +and so it's that concentration at the + + align:start position:0% +and so it's that concentration at the + + + align:start position:0% +and so it's that concentration at the +junction that determines the flux across + + align:start position:0% +junction that determines the flux across + + + align:start position:0% +junction that determines the flux across +the junction so make sense okay okay and + + align:start position:0% +the junction so make sense okay okay and + + + align:start position:0% +the junction so make sense okay okay and +so there's also this other loose + + align:start position:0% +so there's also this other loose + + + align:start position:0% +so there's also this other loose +dependence on vo C on your diffusion + + align:start position:0% +dependence on vo C on your diffusion + + + align:start position:0% +dependence on vo C on your diffusion +length and so if you recall from a few + + align:start position:0% +length and so if you recall from a few + + + align:start position:0% +length and so if you recall from a few +lectures ago this is your the equation + + align:start position:0% +lectures ago this is your the equation + + + align:start position:0% +lectures ago this is your the equation +for vo C is dependent on your + + align:start position:0% +for vo C is dependent on your + + + align:start position:0% +for vo C is dependent on your +short-circuit current temperature and + + align:start position:0% +short-circuit current temperature and + + + align:start position:0% +short-circuit current temperature and +your saturation current which you can + + align:start position:0% +your saturation current which you can + + + align:start position:0% +your saturation current which you can +also often think of as your reverse bias + + align:start position:0% +also often think of as your reverse bias + + + align:start position:0% +also often think of as your reverse bias +current and your saturation current is + + align:start position:0% +current and your saturation current is + + + align:start position:0% +current and your saturation current is +dependent on your diffusion length JSC + + align:start position:0% +dependent on your diffusion length JSC + + + align:start position:0% +dependent on your diffusion length JSC +if you've recall was linearly + + align:start position:0% +if you've recall was linearly + + + align:start position:0% +if you've recall was linearly +proportional to the diffusion length so + + align:start position:0% +proportional to the diffusion length so + + + align:start position:0% +proportional to the diffusion length so +the vo C actually scales with the + + align:start position:0% +the vo C actually scales with the + + + align:start position:0% +the vo C actually scales with the +natural log of the square of the + + align:start position:0% +natural log of the square of the + + + align:start position:0% +natural log of the square of the +diffusion length and if you pull out + + align:start position:0% +diffusion length and if you pull out + + + align:start position:0% +diffusion length and if you pull out +that exponent it just squares with the + + align:start position:0% +that exponent it just squares with the + + + align:start position:0% +that exponent it just squares with the +natural log of your diffusion length and + + align:start position:0% +natural log of your diffusion length and + + + align:start position:0% +natural log of your diffusion length and +again very very simple analogy we're + + align:start position:0% +again very very simple analogy we're + + + align:start position:0% +again very very simple analogy we're +assuming again that fill factor is not + + align:start position:0% +assuming again that fill factor is not + + + align:start position:0% +assuming again that fill factor is not +really affected by your diffusion length + + align:start position:0% +really affected by your diffusion length + + + align:start position:0% +really affected by your diffusion length +and that your efficiency is proportional + + align:start position:0% +and that your efficiency is proportional + + + align:start position:0% +and that your efficiency is proportional +to the product of your JSC and your vo C + + align:start position:0% +to the product of your JSC and your vo C + + + align:start position:0% +to the product of your JSC and your vo C +so your short circuit current your open + + align:start position:0% +so your short circuit current your open + + + align:start position:0% +so your short circuit current your open +circuit voltage and you can see as you + + align:start position:0% +circuit voltage and you can see as you + + + align:start position:0% +circuit voltage and you can see as you +go to longer diffusion lengths there's + + align:start position:0% +go to longer diffusion lengths there's + + + align:start position:0% +go to longer diffusion lengths there's +this area of diminishing return and + + align:start position:0% +this area of diminishing return and + + + align:start position:0% +this area of diminishing return and +again there's two different regimes here + + align:start position:0% +again there's two different regimes here + + + align:start position:0% +again there's two different regimes here +one is when your diffusion length is + + align:start position:0% +one is when your diffusion length is + + + align:start position:0% +one is when your diffusion length is +again much less than your device + + align:start position:0% +again much less than your device + + + align:start position:0% +again much less than your device +thickness you can see that uses a huge + + align:start position:0% +thickness you can see that uses a huge + + + align:start position:0% +thickness you can see that uses a huge +increase in efficiency but as your + + align:start position:0% +increase in efficiency but as your + + + align:start position:0% +increase in efficiency but as your +diffusion leaks gets well well above + + align:start position:0% +diffusion leaks gets well well above + + + align:start position:0% +diffusion leaks gets well well above +your device thickness that becomes less + + align:start position:0% +your device thickness that becomes less + + + align:start position:0% +your device thickness that becomes less +and less important okay so how do you + + align:start position:0% +and less important okay so how do you + + + align:start position:0% +and less important okay so how do you +deal with this so if you have let's say + + align:start position:0% +deal with this so if you have let's say + + + align:start position:0% +deal with this so if you have let's say +suppose you want to make a really cheap + + align:start position:0% +suppose you want to make a really cheap + + + align:start position:0% +suppose you want to make a really cheap +solar cell and you have a very dirty + + align:start position:0% +solar cell and you have a very dirty + + + align:start position:0% +solar cell and you have a very dirty +material with very short lifetime shown + + align:start position:0% +material with very short lifetime shown + + + align:start position:0% +material with very short lifetime shown +here there's kind of several ideas of + + align:start position:0% +here there's kind of several ideas of + + + align:start position:0% +here there's kind of several ideas of +what you can do you can have a very very + + align:start position:0% +what you can do you can have a very very + + + align:start position:0% +what you can do you can have a very very +thin device now that's a problem if you + + align:start position:0% +thin device now that's a problem if you + + + align:start position:0% +thin device now that's a problem if you +can't absorb it very well so you can + + align:start position:0% +can't absorb it very well so you can + + + align:start position:0% +can't absorb it very well so you can +have some kind of optical tricks you can + + align:start position:0% +have some kind of optical tricks you can + + + align:start position:0% +have some kind of optical tricks you can +do surface texturing there's all sorts + + align:start position:0% +do surface texturing there's all sorts + + + align:start position:0% +do surface texturing there's all sorts +of other ideas for basically having the + + align:start position:0% +of other ideas for basically having the + + + align:start position:0% +of other ideas for basically having the +carriers come in at angles or having a + + align:start position:0% +carriers come in at angles or having a + + + align:start position:0% +carriers come in at angles or having a +good reflector on the back so that's + + align:start position:0% +good reflector on the back so that's + + + align:start position:0% +good reflector on the back so that's +ways you can with you can work with very + + align:start position:0% +ways you can with you can work with very + + + align:start position:0% +ways you can with you can work with very +low diffusion length materials and still + + align:start position:0% +low diffusion length materials and still + + + align:start position:0% +low diffusion length materials and still +get a device efficiency that's not not + + align:start position:0% +get a device efficiency that's not not + + + align:start position:0% +get a device efficiency that's not not +too bad okay now we're going to talk + + align:start position:0% +too bad okay now we're going to talk + + + align:start position:0% +too bad okay now we're going to talk +quickly about how our minority carrier + + align:start position:0% +quickly about how our minority carrier + + + align:start position:0% +quickly about how our minority carrier +diffusion length is measured and again + + align:start position:0% +diffusion length is measured and again + + + align:start position:0% +diffusion length is measured and again +this is something we're able to do in + + align:start position:0% +this is something we're able to do in + + + align:start position:0% +this is something we're able to do in +our lab and one of the important things + + align:start position:0% +our lab and one of the important things + + + align:start position:0% +our lab and one of the important things +to say is define is collection + + align:start position:0% +to say is define is collection + + + align:start position:0% +to say is define is collection +probability so for example if this is + + align:start position:0% +probability so for example if this is + + + align:start position:0% +probability so for example if this is +our junction right here or our space + + align:start position:0% +our junction right here or our space + + + align:start position:0% +our junction right here or our space +charge region if you generate a carrier + + align:start position:0% +charge region if you generate a carrier + + + align:start position:0% +charge region if you generate a carrier +let's say very very close to the + + align:start position:0% +let's say very very close to the + + + align:start position:0% +let's say very very close to the +junction it's going to have a high or + + align:start position:0% +junction it's going to have a high or + + + align:start position:0% +junction it's going to have a high or +near Unity probability of making it to + + align:start position:0% +near Unity probability of making it to + + + align:start position:0% +near Unity probability of making it to +the direction and being collected if + + align:start position:0% +the direction and being collected if + + + align:start position:0% +the direction and being collected if +it's generated very very very far away + + align:start position:0% +it's generated very very very far away + + + align:start position:0% +it's generated very very very far away +it's going to have a lower probability + + align:start position:0% +it's going to have a lower probability + + + align:start position:0% +it's going to have a lower probability +and that's what this graph is trying to + + align:start position:0% +and that's what this graph is trying to + + + align:start position:0% +and that's what this graph is trying to +show is that right near the junction you + + align:start position:0% +show is that right near the junction you + + + align:start position:0% +show is that right near the junction you +have near Unity collection probability + + align:start position:0% +have near Unity collection probability + + + align:start position:0% +have near Unity collection probability +and as you go away it comes down and the + + align:start position:0% +and as you go away it comes down and the + + + align:start position:0% +and as you go away it comes down and the +different colored lines are showing kind + + align:start position:0% +different colored lines are showing kind + + + align:start position:0% +different colored lines are showing kind +of different ways of increasing that + + align:start position:0% +of different ways of increasing that + + + align:start position:0% +of different ways of increasing that +diffusion length surface passivation is + + align:start position:0% +diffusion length surface passivation is + + + align:start position:0% +diffusion length surface passivation is +important we'll talk about what that is + + align:start position:0% +important we'll talk about what that is + + + align:start position:0% +important we'll talk about what that is +soon and also diffusion lengths you if + + align:start position:0% +soon and also diffusion lengths you if + + + align:start position:0% +soon and also diffusion lengths you if +you're limited by + + align:start position:0% +you're limited by + + + align:start position:0% +you're limited by +fusion length you can see this very very + + align:start position:0% +fusion length you can see this very very + + + align:start position:0% +fusion length you can see this very very +sharp drop-off right here it's + + align:start position:0% +sharp drop-off right here it's + + + align:start position:0% +sharp drop-off right here it's +technically defined as reaching the + + align:start position:0% +technically defined as reaching the + + + align:start position:0% +technically defined as reaching the +junction and being separated which in + + align:start position:0% +junction and being separated which in + + + align:start position:0% +junction and being separated which in +essence will hopefully be the same thing + + align:start position:0% +essence will hopefully be the same thing + + + align:start position:0% +essence will hopefully be the same thing +yeah it can it can affect the diffusion + + align:start position:0% +yeah it can it can affect the diffusion + + + align:start position:0% +yeah it can it can affect the diffusion +length and will or the effective + + align:start position:0% +length and will or the effective + + + align:start position:0% +length and will or the effective +diffusion might we'll get to that in a + + align:start position:0% +diffusion might we'll get to that in a + + + align:start position:0% +diffusion might we'll get to that in a +second it'll be a bit later this is kind + + align:start position:0% +second it'll be a bit later this is kind + + + align:start position:0% +second it'll be a bit later this is kind +of just showing that there's a lot of + + align:start position:0% +of just showing that there's a lot of + + + align:start position:0% +of just showing that there's a lot of +different material parameters not just + + align:start position:0% +different material parameters not just + + + align:start position:0% +different material parameters not just +your diffusion length that can really + + align:start position:0% +your diffusion length that can really + + + align:start position:0% +your diffusion length that can really +affect your device performance in your + + align:start position:0% +affect your device performance in your + + + align:start position:0% +affect your device performance in your +collection probability Oh so if you + + align:start position:0% +collection probability Oh so if you + + + align:start position:0% +collection probability Oh so if you +recall a few slides back we said that + + align:start position:0% +recall a few slides back we said that + + + align:start position:0% +recall a few slides back we said that +our short-circuit current was directly + + align:start position:0% +our short-circuit current was directly + + + align:start position:0% +our short-circuit current was directly +proportional to our diffusion length and + + align:start position:0% +proportional to our diffusion length and + + + align:start position:0% +proportional to our diffusion length and +the reason is that if you're generating + + align:start position:0% +the reason is that if you're generating + + + align:start position:0% +the reason is that if you're generating +carriers within the diffusion length you + + align:start position:0% +carriers within the diffusion length you + + + align:start position:0% +carriers within the diffusion length you +generally think of that as the region of + + align:start position:0% +generally think of that as the region of + + + align:start position:0% +generally think of that as the region of +which you're actually collecting those + + align:start position:0% +which you're actually collecting those + + + align:start position:0% +which you're actually collecting those +carriers right and if you go back to the + + align:start position:0% +carriers right and if you go back to the + + + align:start position:0% +carriers right and if you go back to the +next slide that kind of makes sense and + + align:start position:0% +next slide that kind of makes sense and + + + align:start position:0% +next slide that kind of makes sense and +so this is highlighted so this is our + + align:start position:0% +so this is highlighted so this is our + + + align:start position:0% +so this is highlighted so this is our +junction here we have our n-type + + align:start position:0% +junction here we have our n-type + + + align:start position:0% +junction here we have our n-type +material on top our p-type below and + + align:start position:0% +material on top our p-type below and + + + align:start position:0% +material on top our p-type below and +within a diffusion length of your + + align:start position:0% +within a diffusion length of your + + + align:start position:0% +within a diffusion length of your +minority carrier so on your p-type side + + align:start position:0% +minority carrier so on your p-type side + + + align:start position:0% +minority carrier so on your p-type side +you hear about the diffusion length of + + align:start position:0% +you hear about the diffusion length of + + + align:start position:0% +you hear about the diffusion length of +your electrons and the n-type side you + + align:start position:0% +your electrons and the n-type side you + + + align:start position:0% +your electrons and the n-type side you +care about the diffusion length of your + + align:start position:0% +care about the diffusion length of your + + + align:start position:0% +care about the diffusion length of your +holes and that's the region where you're + + align:start position:0% +holes and that's the region where you're + + + align:start position:0% +holes and that's the region where you're +really collecting carriers of course + + align:start position:0% +really collecting carriers of course + + + align:start position:0% +really collecting carriers of course +there's like a tail off but the first + + align:start position:0% +there's like a tail off but the first + + + align:start position:0% +there's like a tail off but the first +order approximation this is actually a + + align:start position:0% +order approximation this is actually a + + + align:start position:0% +order approximation this is actually a +very good one and so now putting those + + align:start position:0% +very good one and so now putting those + + + align:start position:0% +very good one and so now putting those +all together if we know how our carriers + + align:start position:0% +all together if we know how our carriers + + + align:start position:0% +all together if we know how our carriers +are generated as a function of X and we + + align:start position:0% +are generated as a function of X and we + + + align:start position:0% +are generated as a function of X and we +know what the collection probability is + + align:start position:0% +know what the collection probability is + + + align:start position:0% +know what the collection probability is +as a function of X based on diffusion + + align:start position:0% +as a function of X based on diffusion + + + align:start position:0% +as a function of X based on diffusion +length surface passivation and other + + align:start position:0% +length surface passivation and other + + + align:start position:0% +length surface passivation and other +parameters we can multiply them and then + + align:start position:0% +parameters we can multiply them and then + + + align:start position:0% +parameters we can multiply them and then +integrate to actually get what our + + align:start position:0% +integrate to actually get what our + + + align:start position:0% +integrate to actually get what our +illuminated current will be + + align:start position:0% + + + + align:start position:0% + +the emitter hmm for most models you + + align:start position:0% +the emitter hmm for most models you + + + align:start position:0% +the emitter hmm for most models you +pretty much assume that anything + + align:start position:0% +pretty much assume that anything + + + align:start position:0% +pretty much assume that anything +absorbed I mean first of all the space + + align:start position:0% +absorbed I mean first of all the space + + + align:start position:0% +absorbed I mean first of all the space +charge region is very very narrow + + align:start position:0% +charge region is very very narrow + + + align:start position:0% +charge region is very very narrow +it's almost assumed just to be + + align:start position:0% +it's almost assumed just to be + + + align:start position:0% +it's almost assumed just to be +negligibly thin and the emitter is + + align:start position:0% +negligibly thin and the emitter is + + + align:start position:0% +negligibly thin and the emitter is +generally very very short and the + + align:start position:0% +generally very very short and the + + + align:start position:0% +generally very very short and the +diffusion lengths are so poor in the + + align:start position:0% +diffusion lengths are so poor in the + + + align:start position:0% +diffusion lengths are so poor in the +emitter for reasons we'll get to soon + + align:start position:0% +emitter for reasons we'll get to soon + + + align:start position:0% +emitter for reasons we'll get to soon +that it's almost a dead layer your + + align:start position:0% +that it's almost a dead layer your + + + align:start position:0% +that it's almost a dead layer your +response at the very short wavelengths + + align:start position:0% +response at the very short wavelengths + + + align:start position:0% +response at the very short wavelengths +where you're absorbing most your light + + align:start position:0% +where you're absorbing most your light + + + align:start position:0% +where you're absorbing most your light +in the emitter generally don't add to + + align:start position:0% +in the emitter generally don't add to + + + align:start position:0% +in the emitter generally don't add to +your short-circuit current and we'll + + align:start position:0% +your short-circuit current and we'll + + + align:start position:0% +your short-circuit current and we'll +talk about that soon so excellent + + align:start position:0% +talk about that soon so excellent + + + align:start position:0% +talk about that soon so excellent +question + + align:start position:0% +question + + + align:start position:0% +question +yeah wait sorry say that again so for + + align:start position:0% +yeah wait sorry say that again so for + + + align:start position:0% +yeah wait sorry say that again so for +certain wavelengths of light let's say + + align:start position:0% +certain wavelengths of light let's say + + + align:start position:0% +certain wavelengths of light let's say +that are this out this curve this is for + + align:start position:0% +that are this out this curve this is for + + + align:start position:0% +that are this out this curve this is for +kind of representing beer Lambert's law + + align:start position:0% +kind of representing beer Lambert's law + + + align:start position:0% +kind of representing beer Lambert's law +if it attenuates less drastically that + + align:start position:0% +if it attenuates less drastically that + + + align:start position:0% +if it attenuates less drastically that +characteristic absorption length if it's + + align:start position:0% +characteristic absorption length if it's + + + align:start position:0% +characteristic absorption length if it's +a lot longer than this length here then + + align:start position:0% +a lot longer than this length here then + + + align:start position:0% +a lot longer than this length here then +yes you can assume that this emitter + + align:start position:0% +yes you can assume that this emitter + + + align:start position:0% +yes you can assume that this emitter +region is negligibly thin and that's a + + align:start position:0% +region is negligibly thin and that's a + + + align:start position:0% +region is negligibly thin and that's a +little bit what the homework goes over + + align:start position:0% +little bit what the homework goes over + + + align:start position:0% +little bit what the homework goes over +as well in problem 3 excellent question + + align:start position:0% +as well in problem 3 excellent question + + + align:start position:0% +as well in problem 3 excellent question +and so what we care about is kind of the + + align:start position:0% +and so what we care about is kind of the + + + align:start position:0% +and so what we care about is kind of the +spectral response of our short-circuit + + align:start position:0% +spectral response of our short-circuit + + + align:start position:0% +spectral response of our short-circuit +current so what what this is is this is + + align:start position:0% +current so what what this is is this is + + + align:start position:0% +current so what what this is is this is +a quantum efficiency tool this is + + align:start position:0% +a quantum efficiency tool this is + + + align:start position:0% +a quantum efficiency tool this is +something we have in our lab it's a + + align:start position:0% +something we have in our lab it's a + + + align:start position:0% +something we have in our lab it's a +really fun tool to play around with how + + align:start position:0% +really fun tool to play around with how + + + align:start position:0% +really fun tool to play around with how +it works is you basically have let's say + + align:start position:0% +it works is you basically have let's say + + + align:start position:0% +it works is you basically have let's say +we have a light source that's white + + align:start position:0% +we have a light source that's white + + + align:start position:0% +we have a light source that's white +light and it goes through a series of + + align:start position:0% +light and it goes through a series of + + + align:start position:0% +light and it goes through a series of +filters there's a monochromator which + + align:start position:0% +filters there's a monochromator which + + + align:start position:0% +filters there's a monochromator which +basically it diffracts the light so it + + align:start position:0% +basically it diffracts the light so it + + + align:start position:0% +basically it diffracts the light so it +spatially separates the light kind of + + align:start position:0% +spatially separates the light kind of + + + align:start position:0% +spatially separates the light kind of +like a rainbow and then you can focus + + align:start position:0% +like a rainbow and then you can focus + + + align:start position:0% +like a rainbow and then you can focus +that on to your solar cell and measure + + align:start position:0% +that on to your solar cell and measure + + + align:start position:0% +that on to your solar cell and measure +the current output and under short + + align:start position:0% +the current output and under short + + + align:start position:0% +the current output and under short +circuit conditions and that will tell + + align:start position:0% +circuit conditions and that will tell + + + align:start position:0% +circuit conditions and that will tell +you because you know the carrier + + align:start position:0% +you because you know the carrier + + + align:start position:0% +you because you know the carrier +generation profile for different + + align:start position:0% +generation profile for different + + + align:start position:0% +generation profile for different +wavelengths of light because you know + + align:start position:0% +wavelengths of light because you know + + + align:start position:0% +wavelengths of light because you know +what alpha is for silicon you can + + align:start position:0% +what alpha is for silicon you can + + + align:start position:0% +what alpha is for silicon you can +actually pretty well calculate what what + + align:start position:0% +actually pretty well calculate what what + + + align:start position:0% +actually pretty well calculate what what +your diffusion length is and we'll talk + + align:start position:0% +your diffusion length is and we'll talk + + + align:start position:0% +your diffusion length is and we'll talk +about that on the next slide so this is + + align:start position:0% +about that on the next slide so this is + + + align:start position:0% +about that on the next slide so this is +kind of what your quantum efficiency + + align:start position:0% +kind of what your quantum efficiency + + + align:start position:0% +kind of what your quantum efficiency +walk like this is I think + + align:start position:0% +walk like this is I think + + + align:start position:0% +walk like this is I think +actually don't know this is + + align:start position:0% +actually don't know this is + + + align:start position:0% +actually don't know this is +internal-external but they're just + + align:start position:0% +internal-external but they're just + + + align:start position:0% +internal-external but they're just +related by a factor of one over R so + + align:start position:0% +related by a factor of one over R so + + + align:start position:0% +related by a factor of one over R so +here your blue response so everything + + align:start position:0% +here your blue response so everything + + + align:start position:0% +here your blue response so everything +that's absorbed right in the near + + align:start position:0% +that's absorbed right in the near + + + align:start position:0% +that's absorbed right in the near +surface region in your emitter generally + + align:start position:0% +surface region in your emitter generally + + + align:start position:0% +surface region in your emitter generally +doesn't get collected and this is due to + + align:start position:0% +doesn't get collected and this is due to + + + align:start position:0% +doesn't get collected and this is due to +really bad diffusion links in the + + align:start position:0% +really bad diffusion links in the + + + align:start position:0% +really bad diffusion links in the +emitter region as you go to longer + + align:start position:0% +emitter region as you go to longer + + + align:start position:0% +emitter region as you go to longer +wavelengths which are due the absorption + + align:start position:0% +wavelengths which are due the absorption + + + align:start position:0% +wavelengths which are due the absorption +length is much much deeper you're + + align:start position:0% +length is much much deeper you're + + + align:start position:0% +length is much much deeper you're +collecting a lot of it and then what do + + align:start position:0% +collecting a lot of it and then what do + + + align:start position:0% +collecting a lot of it and then what do +you think is happening here you're + + align:start position:0% +you think is happening here you're + + + align:start position:0% +you think is happening here you're +generally these longer wavelengths your + + align:start position:0% +generally these longer wavelengths your + + + align:start position:0% +generally these longer wavelengths your +alpha is is so low that you're not + + align:start position:0% +alpha is is so low that you're not + + + align:start position:0% +alpha is is so low that you're not +actually absorbing much of this light + + align:start position:0% +actually absorbing much of this light + + + align:start position:0% +actually absorbing much of this light +which is part of the reason that you're + + align:start position:0% +which is part of the reason that you're + + + align:start position:0% +which is part of the reason that you're +not collecting it or that you're + + align:start position:0% +not collecting it or that you're + + + align:start position:0% +not collecting it or that you're +absorbing it so far away from the + + align:start position:0% +absorbing it so far away from the + + + align:start position:0% +absorbing it so far away from the +junction that it's not being able to + + align:start position:0% +junction that it's not being able to + + + align:start position:0% +junction that it's not being able to +diffuse there and so that's kind of how + + align:start position:0% +diffuse there and so that's kind of how + + + align:start position:0% +diffuse there and so that's kind of how +you can look at these quantum efficiency + + align:start position:0% +you can look at these quantum efficiency + + + align:start position:0% +you can look at these quantum efficiency +curves and it's this region here that's + + align:start position:0% +curves and it's this region here that's + + + align:start position:0% +curves and it's this region here that's +really limited by diffusion lengths and + + align:start position:0% +really limited by diffusion lengths and + + + align:start position:0% +really limited by diffusion lengths and +again you have a homework problem + + align:start position:0% +again you have a homework problem + + + align:start position:0% +again you have a homework problem +discussing how that's done some of the + + align:start position:0% +discussing how that's done some of the + + + align:start position:0% +discussing how that's done some of the +cool other tools I lab can kind of do + + align:start position:0% +cool other tools I lab can kind of do + + + align:start position:0% +cool other tools I lab can kind of do +this but it requires a little more + + align:start position:0% +this but it requires a little more + + + align:start position:0% +this but it requires a little more +I don't know handwork on the operator + + align:start position:0% +I don't know handwork on the operator + + + align:start position:0% +I don't know handwork on the operator +but if you can take different eqe curves + + align:start position:0% +but if you can take different eqe curves + + + align:start position:0% +but if you can take different eqe curves +or iqe curves at different points on + + align:start position:0% +or iqe curves at different points on + + + align:start position:0% +or iqe curves at different points on +your solar cell and you get those + + align:start position:0% +your solar cell and you get those + + + align:start position:0% +your solar cell and you get those +spectrums you'll get a whole bunch of + + align:start position:0% +spectrums you'll get a whole bunch of + + + align:start position:0% +spectrums you'll get a whole bunch of +different spectrum you'll scan with your + + align:start position:0% +different spectrum you'll scan with your + + + align:start position:0% +different spectrum you'll scan with your +your light beam you can actually get the + + align:start position:0% +your light beam you can actually get the + + + align:start position:0% +your light beam you can actually get the +fusion lines as a function of position + + align:start position:0% +fusion lines as a function of position + + + align:start position:0% +fusion lines as a function of position +and get a spatial map of your different + + align:start position:0% +and get a spatial map of your different + + + align:start position:0% +and get a spatial map of your different +diffusion lengths and it's really + + align:start position:0% +diffusion lengths and it's really + + + align:start position:0% +diffusion lengths and it's really +helpful if you're trying to find spatial + + align:start position:0% +helpful if you're trying to find spatial + + + align:start position:0% +helpful if you're trying to find spatial +inhomogeneities in your cell so I + + align:start position:0% +inhomogeneities in your cell so I + + + align:start position:0% +inhomogeneities in your cell so I +believe that this is some multi + + align:start position:0% +believe that this is some multi + + + align:start position:0% +believe that this is some multi +crystalline cell and you see all sorts + + align:start position:0% +crystalline cell and you see all sorts + + + align:start position:0% +crystalline cell and you see all sorts +of grain boundaries and those are areas + + align:start position:0% +of grain boundaries and those are areas + + + align:start position:0% +of grain boundaries and those are areas +of very short diffusion length and we'll + + align:start position:0% +of very short diffusion length and we'll + + + align:start position:0% +of very short diffusion length and we'll +talk about why that's the case + + align:start position:0% +talk about why that's the case + + + align:start position:0% +talk about why that's the case +actually on the next couple slides + + align:start position:0% +actually on the next couple slides + + + align:start position:0% +actually on the next couple slides +question yeah + + align:start position:0% + + + + align:start position:0% + +so you're okay so alpha is what tells + + align:start position:0% +so you're okay so alpha is what tells + + + align:start position:0% +so you're okay so alpha is what tells +you is your absorption coefficient right + + align:start position:0% +you is your absorption coefficient right + + + align:start position:0% +you is your absorption coefficient right +and it's often in units of one over + + align:start position:0% +and it's often in units of one over + + + align:start position:0% +and it's often in units of one over +centimeters so inverse centimeters and + + align:start position:0% +centimeters so inverse centimeters and + + + align:start position:0% +centimeters so inverse centimeters and +so if you plot what that looks like it's + + align:start position:0% +so if you plot what that looks like it's + + + align:start position:0% +so if you plot what that looks like it's +some exponential function with X right + + align:start position:0% +some exponential function with X right + + + align:start position:0% +some exponential function with X right +and the point two which is attenuated by + + align:start position:0% +and the point two which is attenuated by + + + align:start position:0% +and the point two which is attenuated by +a factor of one over EE + + align:start position:0% +a factor of one over EE + + + align:start position:0% +a factor of one over EE +that point is one over alpha and that's + + align:start position:0% +that point is one over alpha and that's + + + align:start position:0% +that point is one over alpha and that's +often called the absorption depth or am + + align:start position:0% +often called the absorption depth or am + + + align:start position:0% +often called the absorption depth or am +I thinking of absorption length of that + + align:start position:0% +I thinking of absorption length of that + + + align:start position:0% +I thinking of absorption length of that +wavelength and alpha will vary as a + + align:start position:0% +wavelength and alpha will vary as a + + + align:start position:0% +wavelength and alpha will vary as a +function of wavelength if you recall + + align:start position:0% +function of wavelength if you recall + + + align:start position:0% +function of wavelength if you recall +that if you look at lambda for silicon + + align:start position:0% +that if you look at lambda for silicon + + + align:start position:0% +that if you look at lambda for silicon +it's something that continues to go down + + align:start position:0% +it's something that continues to go down + + + align:start position:0% +it's something that continues to go down +at longer wavelengths so the short + + align:start position:0% +at longer wavelengths so the short + + + align:start position:0% +at longer wavelengths so the short +wavelengths are absorbed very strongly + + align:start position:0% +wavelengths are absorbed very strongly + + + align:start position:0% +wavelengths are absorbed very strongly +and so most of the light is absorbed + + align:start position:0% +and so most of the light is absorbed + + + align:start position:0% +and so most of the light is absorbed +very very close to the surface where the + + align:start position:0% +very very close to the surface where the + + + align:start position:0% +very very close to the surface where the +longer wavelengths most of the light is + + align:start position:0% +longer wavelengths most of the light is + + + align:start position:0% +longer wavelengths most of the light is +actually absorbed better they're far + + align:start position:0% +actually absorbed better they're far + + + align:start position:0% +actually absorbed better they're far +from the surface that make sense and so + + align:start position:0% +from the surface that make sense and so + + + align:start position:0% +from the surface that make sense and so +there's a difference between your + + align:start position:0% +there's a difference between your + + + align:start position:0% +there's a difference between your +absorption length and your diffusion + + align:start position:0% +absorption length and your diffusion + + + align:start position:0% +absorption length and your diffusion +length and that ratio is what's really + + align:start position:0% +length and that ratio is what's really + + + align:start position:0% +length and that ratio is what's really +important right if you're absorbing + + align:start position:0% +important right if you're absorbing + + + align:start position:0% +important right if you're absorbing +really far away from the junction but + + align:start position:0% +really far away from the junction but + + + align:start position:0% +really far away from the junction but +you have a long diffusion length there's + + align:start position:0% +you have a long diffusion length there's + + + align:start position:0% +you have a long diffusion length there's +a greater chance of it making there and + + align:start position:0% +a greater chance of it making there and + + + align:start position:0% +a greater chance of it making there and +it's that ratio that's really really + + align:start position:0% +it's that ratio that's really really + + + align:start position:0% +it's that ratio that's really really +important does that answer your question + + align:start position:0% + + + + align:start position:0% + +okay so what limits is minority carrier + + align:start position:0% +okay so what limits is minority carrier + + + align:start position:0% +okay so what limits is minority carrier +diffusion length we're gonna get to the + + align:start position:0% +diffusion length we're gonna get to the + + + align:start position:0% +diffusion length we're gonna get to the +equation a second for the minority + + align:start position:0% +equation a second for the minority + + + align:start position:0% +equation a second for the minority +carrier diffusion length but basically + + align:start position:0% +carrier diffusion length but basically + + + align:start position:0% +carrier diffusion length but basically +when you excite an electron hole pair + + align:start position:0% +when you excite an electron hole pair + + + align:start position:0% +when you excite an electron hole pair +you have this mobile electron and it's + + align:start position:0% +you have this mobile electron and it's + + + align:start position:0% +you have this mobile electron and it's +in this excited state you've given it + + align:start position:0% +in this excited state you've given it + + + align:start position:0% +in this excited state you've given it +this energy from a photon and now can + + align:start position:0% +this energy from a photon and now can + + + align:start position:0% +this energy from a photon and now can +move around and it can only exist for a + + align:start position:0% +move around and it can only exist for a + + + align:start position:0% +move around and it can only exist for a +certain amount of time before it finds + + align:start position:0% +certain amount of time before it finds + + + align:start position:0% +certain amount of time before it finds +another hole and recombine and that + + align:start position:0% +another hole and recombine and that + + + align:start position:0% +another hole and recombine and that +event again is called recombination and + + align:start position:0% +event again is called recombination and + + + align:start position:0% +event again is called recombination and +a lot of this is actually determined by + + align:start position:0% +a lot of this is actually determined by + + + align:start position:0% +a lot of this is actually determined by +the size of grain + + align:start position:0% +the size of grain + + + align:start position:0% +the size of grain +in your material if you've seen think on + + align:start position:0% +in your material if you've seen think on + + + align:start position:0% +in your material if you've seen think on +the the cell that Tonio brought in + + align:start position:0% +the the cell that Tonio brought in + + + align:start position:0% +the the cell that Tonio brought in +earlier + + align:start position:0% +earlier + + + align:start position:0% +earlier +sorry I don't have a good example it + + align:start position:0% +sorry I don't have a good example it + + + align:start position:0% +sorry I don't have a good example it +didn't just look like one kind of flat + + align:start position:0% +didn't just look like one kind of flat + + + align:start position:0% +didn't just look like one kind of flat +plane you could see like different grain + + align:start position:0% +plane you could see like different grain + + + align:start position:0% +plane you could see like different grain +orientations and the edges of those + + align:start position:0% +orientations and the edges of those + + + align:start position:0% +orientations and the edges of those +grains are called grain boundaries and + + align:start position:0% +grains are called grain boundaries and + + + align:start position:0% +grains are called grain boundaries and +those can act as kind of recombination + + align:start position:0% +those can act as kind of recombination + + + align:start position:0% +those can act as kind of recombination +centers and actually reduce your that's + + align:start position:0% +centers and actually reduce your that's + + + align:start position:0% +centers and actually reduce your that's +called your lifetime which we're gonna + + align:start position:0% +called your lifetime which we're gonna + + + align:start position:0% +called your lifetime which we're gonna +get to on this slide okay so this slide + + align:start position:0% +get to on this slide okay so this slide + + + align:start position:0% +get to on this slide okay so this slide +has a lot of stuff going on what it's + + align:start position:0% +has a lot of stuff going on what it's + + + align:start position:0% +has a lot of stuff going on what it's +saying is that your diffusion length is + + align:start position:0% + + + + align:start position:0% + +characteristic of the diffusivity the + + align:start position:0% +characteristic of the diffusivity the + + + align:start position:0% +characteristic of the diffusivity the +product the square root of the product + + align:start position:0% +product the square root of the product + + + align:start position:0% +product the square root of the product +of your diffusivity in your lifetime the + + align:start position:0% +of your diffusivity in your lifetime the + + + align:start position:0% +of your diffusivity in your lifetime the +way I like to think of diffusivity is + + align:start position:0% +way I like to think of diffusivity is + + + align:start position:0% +way I like to think of diffusivity is +that you have it goes up with + + align:start position:0% +that you have it goes up with + + + align:start position:0% +that you have it goes up with +temperature and it's also affected by + + align:start position:0% +temperature and it's also affected by + + + align:start position:0% +temperature and it's also affected by +your mobility the mobility is saying + + align:start position:0% +your mobility the mobility is saying + + + align:start position:0% +your mobility the mobility is saying +that if you apply let's say an external + + align:start position:0% +that if you apply let's say an external + + + align:start position:0% +that if you apply let's say an external +field an electric field how well can + + align:start position:0% +field an electric field how well can + + + align:start position:0% +field an electric field how well can +those electrons move around so we're + + align:start position:0% +those electrons move around so we're + + + align:start position:0% +those electrons move around so we're +really high mobility means that those + + align:start position:0% +really high mobility means that those + + + align:start position:0% +really high mobility means that those +electrons can move really easily and + + align:start position:0% +electrons can move really easily and + + + align:start position:0% +electrons can move really easily and +you'll accelerate them really quickly + + align:start position:0% +you'll accelerate them really quickly + + + align:start position:0% +you'll accelerate them really quickly +we're very low mobility means that + + align:start position:0% +we're very low mobility means that + + + align:start position:0% +we're very low mobility means that +they're gonna continue to hit into + + align:start position:0% +they're gonna continue to hit into + + + align:start position:0% +they're gonna continue to hit into +things and bump around and not move + + align:start position:0% +things and bump around and not move + + + align:start position:0% +things and bump around and not move +around too well and your diffusion is + + align:start position:0% +around too well and your diffusion is + + + align:start position:0% +around too well and your diffusion is +this kind of thermal process if you + + align:start position:0% +this kind of thermal process if you + + + align:start position:0% +this kind of thermal process if you +think of let's say gases in a room and + + align:start position:0% +think of let's say gases in a room and + + + align:start position:0% +think of let's say gases in a room and +you have a hot gas that's going to + + align:start position:0% +you have a hot gas that's going to + + + align:start position:0% +you have a hot gas that's going to +diffuse a lot faster so it's the product + + align:start position:0% +diffuse a lot faster so it's the product + + + align:start position:0% +diffuse a lot faster so it's the product +of these two things it's it's kind of + + align:start position:0% +of these two things it's it's kind of + + + align:start position:0% +of these two things it's it's kind of +how well it can move around times it's + + align:start position:0% +how well it can move around times it's + + + align:start position:0% +how well it can move around times it's +kind of thermal energy that it has to + + align:start position:0% +kind of thermal energy that it has to + + + align:start position:0% +kind of thermal energy that it has to +move around the energy it has for moving + + align:start position:0% +move around the energy it has for moving + + + align:start position:0% +move around the energy it has for moving +and so that's kind of what the + + align:start position:0% +and so that's kind of what the + + + align:start position:0% +and so that's kind of what the +diffusivity means to me the life time + + align:start position:0% +diffusivity means to me the life time + + + align:start position:0% +diffusivity means to me the life time +again is what I mentioned earlier is + + align:start position:0% +again is what I mentioned earlier is + + + align:start position:0% +again is what I mentioned earlier is +that when you create this excited + + align:start position:0% +that when you create this excited + + + align:start position:0% +that when you create this excited +electron that's now free to move this + + align:start position:0% +electron that's now free to move this + + + align:start position:0% +electron that's now free to move this +mobile electron it can move around in + + align:start position:0% +mobile electron it can move around in + + + align:start position:0% +mobile electron it can move around in +explore a certain area that area or + + align:start position:0% +explore a certain area that area or + + + align:start position:0% +explore a certain area that area or +sorry volume is defined by the diffusion + + align:start position:0% +sorry volume is defined by the diffusion + + + align:start position:0% +sorry volume is defined by the diffusion +length and it exists in that excited + + align:start position:0% +length and it exists in that excited + + + align:start position:0% +length and it exists in that excited +state for some amount of time tau and + + align:start position:0% +state for some amount of time tau and + + + align:start position:0% +state for some amount of time tau and +that tau is not you know the not every + + align:start position:0% +that tau is not you know the not every + + + align:start position:0% +that tau is not you know the not every +carrier that's generated necessarily has + + align:start position:0% +carrier that's generated necessarily has + + + align:start position:0% +carrier that's generated necessarily has +that lifetime but it's a characteristic + + align:start position:0% +that lifetime but it's a characteristic + + + align:start position:0% +that lifetime but it's a characteristic +lifetime that it could have oh yeah and + + align:start position:0% +lifetime that it could have oh yeah and + + + align:start position:0% +lifetime that it could have oh yeah and +then they're pointed out here what they + + align:start position:0% +then they're pointed out here what they + + + align:start position:0% +then they're pointed out here what they +are + + align:start position:0% + + + + align:start position:0% + +okay so that's what affects our + + align:start position:0% +okay so that's what affects our + + + align:start position:0% +okay so that's what affects our +diffusion like so in the next bunch of + + align:start position:0% +diffusion like so in the next bunch of + + + align:start position:0% +diffusion like so in the next bunch of +slides we're going to talk about mainly + + align:start position:0% +slides we're going to talk about mainly + + + align:start position:0% +slides we're going to talk about mainly +how we can affect tau so tau is mainly + + align:start position:0% +how we can affect tau so tau is mainly + + + align:start position:0% +how we can affect tau so tau is mainly +affected by recombination centers so + + align:start position:0% +affected by recombination centers so + + + align:start position:0% +affected by recombination centers so +defects and semiconductors and a few + + align:start position:0% +defects and semiconductors and a few + + + align:start position:0% +defects and semiconductors and a few +other things that we're going to talk + + align:start position:0% +other things that we're going to talk + + + align:start position:0% +other things that we're going to talk +about and then this is almost kind of + + align:start position:0% +about and then this is almost kind of + + + align:start position:0% +about and then this is almost kind of +limited depending on what kind of + + align:start position:0% +limited depending on what kind of + + + align:start position:0% +limited depending on what kind of +materials you're using the mobility and + + align:start position:0% +materials you're using the mobility and + + + align:start position:0% +materials you're using the mobility and +so we'll talk about that as well so all + + align:start position:0% +so we'll talk about that as well so all + + + align:start position:0% +so we'll talk about that as well so all +right what effects lifetime we're gonna + + align:start position:0% +right what effects lifetime we're gonna + + + align:start position:0% +right what effects lifetime we're gonna +go over again basic recombination + + align:start position:0% +go over again basic recombination + + + align:start position:0% +go over again basic recombination +mechanisms and semiconductors there's a + + align:start position:0% +mechanisms and semiconductors there's a + + + align:start position:0% +mechanisms and semiconductors there's a +lot of them a lot of them have some + + align:start position:0% + + + + align:start position:0% + +rather complex kind of equations behind + + align:start position:0% +rather complex kind of equations behind + + + align:start position:0% +rather complex kind of equations behind +them we're not gonna delve too deeply + + align:start position:0% +them we're not gonna delve too deeply + + + align:start position:0% +them we're not gonna delve too deeply +into how to derive them you're welcome + + align:start position:0% +into how to derive them you're welcome + + + align:start position:0% +into how to derive them you're welcome +to do that it was actually kind of fun + + align:start position:0% +to do that it was actually kind of fun + + + align:start position:0% +to do that it was actually kind of fun +to do on my own and refresh myself so + + align:start position:0% +to do on my own and refresh myself so + + + align:start position:0% +to do on my own and refresh myself so +it's really useful and also be able to + + align:start position:0% +it's really useful and also be able to + + + align:start position:0% +it's really useful and also be able to +calculate our excess carrier + + align:start position:0% +calculate our excess carrier + + + align:start position:0% +calculate our excess carrier +concentration which we're gonna do in + + align:start position:0% +concentration which we're gonna do in + + + align:start position:0% +concentration which we're gonna do in +the next couple slides so okay and let's + + align:start position:0% +the next couple slides so okay and let's + + + align:start position:0% +the next couple slides so okay and let's +say for p-type material or sorry n-type + + align:start position:0% +say for p-type material or sorry n-type + + + align:start position:0% +say for p-type material or sorry n-type +material the number of mobile electrons + + align:start position:0% +material the number of mobile electrons + + + align:start position:0% +material the number of mobile electrons +you have is defined as N and not is very + + align:start position:0% +you have is defined as N and not is very + + + align:start position:0% +you have is defined as N and not is very +frequently your dopant density so these + + align:start position:0% +frequently your dopant density so these + + + align:start position:0% +frequently your dopant density so these +come up with 1/2 the time sorry wrong + + align:start position:0% +come up with 1/2 the time sorry wrong + + + align:start position:0% +come up with 1/2 the time sorry wrong +direction are generally the doping + + align:start position:0% +direction are generally the doping + + + align:start position:0% +direction are generally the doping +concentration right so if you're putting + + align:start position:0% +concentration right so if you're putting + + + align:start position:0% +concentration right so if you're putting +in phosphorous atoms into your silicon + + align:start position:0% +in phosphorous atoms into your silicon + + + align:start position:0% +in phosphorous atoms into your silicon +it would be the concentration of + + align:start position:0% +it would be the concentration of + + + align:start position:0% +it would be the concentration of +phosphorous atoms your Delta n is how + + align:start position:0% +phosphorous atoms your Delta n is how + + + align:start position:0% +phosphorous atoms your Delta n is how +many extra electrons are you adding + + align:start position:0% +many extra electrons are you adding + + + align:start position:0% +many extra electrons are you adding +mobile electrons due to the photo + + align:start position:0% +mobile electrons due to the photo + + + align:start position:0% +mobile electrons due to the photo +excitation of light right and so that's + + align:start position:0% +excitation of light right and so that's + + + align:start position:0% +excitation of light right and so that's +what this is saying is that you have + + align:start position:0% +what this is saying is that you have + + + align:start position:0% +what this is saying is that you have +some your Delta n is equal to your + + align:start position:0% +some your Delta n is equal to your + + + align:start position:0% +some your Delta n is equal to your +generation rate so your generation rate + + align:start position:0% +generation rate so your generation rate + + + align:start position:0% +generation rate so your generation rate +is generally in units of carriers per + + align:start position:0% +is generally in units of carriers per + + + align:start position:0% +is generally in units of carriers per +volume per second so how many carriers + + align:start position:0% +volume per second so how many carriers + + + align:start position:0% +volume per second so how many carriers +you're generating in a certain volume + + align:start position:0% +you're generating in a certain volume + + + align:start position:0% +you're generating in a certain volume +and because Delta n is actually a + + align:start position:0% +and because Delta n is actually a + + + align:start position:0% +and because Delta n is actually a +density you need to say okay how long do + + align:start position:0% +density you need to say okay how long do + + + align:start position:0% +density you need to say okay how long do +those carriers last once they're excited + + align:start position:0% +those carriers last once they're excited + + + align:start position:0% +those carriers last once they're excited +and so is this GTL product is what gives + + align:start position:0% +and so is this GTL product is what gives + + + align:start position:0% +and so is this GTL product is what gives +you your Delta n now when working with + + align:start position:0% +you your Delta n now when working with + + + align:start position:0% +you your Delta n now when working with +silicon it's really important to + + align:start position:0% +silicon it's really important to + + + align:start position:0% +silicon it's really important to +understand what the different ratios are + + align:start position:0% +understand what the different ratios are + + + align:start position:0% +understand what the different ratios are +of N and not Delta n your doping + + align:start position:0% +of N and not Delta n your doping + + + align:start position:0% +of N and not Delta n your doping +concentrations so getting these relative + + align:start position:0% +concentrations so getting these relative + + + align:start position:0% +concentrations so getting these relative +numbers in your head is an important + + align:start position:0% +numbers in your head is an important + + + align:start position:0% +numbers in your head is an important +step in moving forward so + + align:start position:0% +step in moving forward so + + + align:start position:0% +step in moving forward so +let's say we subject a piece of silicon + + align:start position:0% +let's say we subject a piece of silicon + + + align:start position:0% +let's say we subject a piece of silicon +to am 1.5 spectra yeah so you're G oh + + align:start position:0% + + + + align:start position:0% + +sorry this is a little off there we go + + align:start position:0% +sorry this is a little off there we go + + + align:start position:0% +sorry this is a little off there we go +sorry about that when I added some + + align:start position:0% +sorry about that when I added some + + + align:start position:0% +sorry about that when I added some +equations so your your generation rate + + align:start position:0% +equations so your your generation rate + + + align:start position:0% +equations so your your generation rate +is on the order of 10 to the 16 a + + align:start position:0% +is on the order of 10 to the 16 a + + + align:start position:0% +is on the order of 10 to the 16 a +carrier lifetime for silicon this is not + + align:start position:0% +carrier lifetime for silicon this is not + + + align:start position:0% +carrier lifetime for silicon this is not +a great lifetime but in okay one is + + align:start position:0% +a great lifetime but in okay one is + + + align:start position:0% +a great lifetime but in okay one is +about 10 microseconds and so as a result + + align:start position:0% +about 10 microseconds and so as a result + + + align:start position:0% +about 10 microseconds and so as a result +of that you'll get about 10 to the 11 + + align:start position:0% +of that you'll get about 10 to the 11 + + + align:start position:0% +of that you'll get about 10 to the 11 +carrier excess carriers per centimeter + + align:start position:0% +carrier excess carriers per centimeter + + + align:start position:0% +carrier excess carriers per centimeter +cubed and if we can't compare that so + + align:start position:0% +cubed and if we can't compare that so + + + align:start position:0% +cubed and if we can't compare that so +for every excess electron we make + + align:start position:0% +for every excess electron we make + + + align:start position:0% +for every excess electron we make +remember we also leave behind a hole so + + align:start position:0% +remember we also leave behind a hole so + + + align:start position:0% +remember we also leave behind a hole so +we have a delta n is generally equal to + + align:start position:0% +we have a delta n is generally equal to + + + align:start position:0% +we have a delta n is generally equal to +Delta P and that's about ten to the + + align:start position:0% +Delta P and that's about ten to the + + + align:start position:0% +Delta P and that's about ten to the +eleventh if we look at our intrinsic + + align:start position:0% +eleventh if we look at our intrinsic + + + align:start position:0% +eleventh if we look at our intrinsic +carrier concentration so if we had no + + align:start position:0% +carrier concentration so if we had no + + + align:start position:0% +carrier concentration so if we had no +dopants how many carriers would we have + + align:start position:0% +dopants how many carriers would we have + + + align:start position:0% +dopants how many carriers would we have +just for the thermal excitation and + + align:start position:0% +just for the thermal excitation and + + + align:start position:0% +just for the thermal excitation and +that's about ten to the ten and so you + + align:start position:0% +that's about ten to the ten and so you + + + align:start position:0% +that's about ten to the ten and so you +can see that your Delta n is actually + + align:start position:0% +can see that your Delta n is actually + + + align:start position:0% +can see that your Delta n is actually +larger than your intrinsic carrier + + align:start position:0% +larger than your intrinsic carrier + + + align:start position:0% +larger than your intrinsic carrier +concentration for silicon under normal + + align:start position:0% +concentration for silicon under normal + + + align:start position:0% +concentration for silicon under normal +illumination conditions now let's take + + align:start position:0% +illumination conditions now let's take + + + align:start position:0% +illumination conditions now let's take +an example suppose we add phosphorus at + + align:start position:0% +an example suppose we add phosphorus at + + + align:start position:0% +an example suppose we add phosphorus at +the order of about 10 to the 16 so + + align:start position:0% +the order of about 10 to the 16 so + + + align:start position:0% +the order of about 10 to the 16 so +that's generally about what a base + + align:start position:0% +that's generally about what a base + + + align:start position:0% +that's generally about what a base +doping concentration should be in that + + align:start position:0% +doping concentration should be in that + + + align:start position:0% +doping concentration should be in that +realm might be a little high but you can + + align:start position:0% +realm might be a little high but you can + + + align:start position:0% +realm might be a little high but you can +see that your while your Delta P is much + + align:start position:0% +see that your while your Delta P is much + + + align:start position:0% +see that your while your Delta P is much +greater than P naught so P naught would + + align:start position:0% +greater than P naught so P naught would + + + align:start position:0% +greater than P naught so P naught would +be how many holes do you have which is a + + align:start position:0% +be how many holes do you have which is a + + + align:start position:0% +be how many holes do you have which is a +ratio of your intrinsic carrier squared + + align:start position:0% +ratio of your intrinsic carrier squared + + + align:start position:0% +ratio of your intrinsic carrier squared +over your dopant density and that's + + align:start position:0% +over your dopant density and that's + + + align:start position:0% +over your dopant density and that's +about 10 to the fourth so it's way way + + align:start position:0% +about 10 to the fourth so it's way way + + + align:start position:0% +about 10 to the fourth so it's way way +less then your then what was there + + align:start position:0% +less then your then what was there + + + align:start position:0% +less then your then what was there +without excitation right so the number + + align:start position:0% +without excitation right so the number + + + align:start position:0% +without excitation right so the number +of holes without any light shining on as + + align:start position:0% +of holes without any light shining on as + + + align:start position:0% +of holes without any light shining on as +P naught you generate a bunch of holes + + align:start position:0% +P naught you generate a bunch of holes + + + align:start position:0% +P naught you generate a bunch of holes +Delta P by shining light on it and you + + align:start position:0% +Delta P by shining light on it and you + + + align:start position:0% +Delta P by shining light on it and you +can see that these numbers are + + align:start position:0% +can see that these numbers are + + + align:start position:0% +can see that these numbers are +drastically different and of course your + + align:start position:0% +drastically different and of course your + + + align:start position:0% +drastically different and of course your +dopant density is actually much much + + align:start position:0% +dopant density is actually much much + + + align:start position:0% +dopant density is actually much much +larger than your Delta n so that on your + + align:start position:0% +larger than your Delta n so that on your + + + align:start position:0% +larger than your Delta n so that on your +majority carriers don't change very much + + align:start position:0% +majority carriers don't change very much + + + align:start position:0% +majority carriers don't change very much +but your minority carriers change very + + align:start position:0% +but your minority carriers change very + + + align:start position:0% +but your minority carriers change very +very drastically that's really what this + + align:start position:0% +very drastically that's really what this + + + align:start position:0% +very drastically that's really what this +is trying to say here under excitation + + align:start position:0% + + + + align:start position:0% + +okay what is lifetime all right so I + + align:start position:0% +okay what is lifetime all right so I + + + align:start position:0% +okay what is lifetime all right so I +hope that bubble shouldn't be up yet + + align:start position:0% + + + + align:start position:0% + +okay so we measure tau by creating some + + align:start position:0% +okay so we measure tau by creating some + + + align:start position:0% +okay so we measure tau by creating some +excess carrier population and then watch + + align:start position:0% +excess carrier population and then watch + + + align:start position:0% +excess carrier population and then watch +them decay and they decay at some rate + + align:start position:0% +them decay and they decay at some rate + + + align:start position:0% +them decay and they decay at some rate +recombination rate and under steady + + align:start position:0% +recombination rate and under steady + + + align:start position:0% +recombination rate and under steady +state conditions so under a constant + + align:start position:0% +state conditions so under a constant + + + align:start position:0% +state conditions so under a constant +elimination if we're not looking at + + align:start position:0% +elimination if we're not looking at + + + align:start position:0% +elimination if we're not looking at +transients your recombination rate is + + align:start position:0% +transients your recombination rate is + + + align:start position:0% +transients your recombination rate is +actually equal to your generation rate + + align:start position:0% +actually equal to your generation rate + + + align:start position:0% +actually equal to your generation rate +so if you compare the two equations on + + align:start position:0% +so if you compare the two equations on + + + align:start position:0% +so if you compare the two equations on +the previous slide they're true under + + align:start position:0% +the previous slide they're true under + + + align:start position:0% +the previous slide they're true under +steady state conditions so that's my + + align:start position:0% +steady state conditions so that's my + + + align:start position:0% +steady state conditions so that's my +public and so your lifetimes will add up + + align:start position:0% +public and so your lifetimes will add up + + + align:start position:0% +public and so your lifetimes will add up +like parallel resistors so we have tau + + align:start position:0% +like parallel resistors so we have tau + + + align:start position:0% +like parallel resistors so we have tau +bulk which is kind of the effective + + align:start position:0% +bulk which is kind of the effective + + + align:start position:0% +bulk which is kind of the effective +lifetime of these photo excited carriers + + align:start position:0% +lifetime of these photo excited carriers + + + align:start position:0% +lifetime of these photo excited carriers +and it's equal to this the 1 over tau + + align:start position:0% +and it's equal to this the 1 over tau + + + align:start position:0% +and it's equal to this the 1 over tau +bulk is equal to 1 over tau radiative so + + align:start position:0% +bulk is equal to 1 over tau radiative so + + + align:start position:0% +bulk is equal to 1 over tau radiative so +this is radiative recombination and this + + align:start position:0% +this is radiative recombination and this + + + align:start position:0% +this is radiative recombination and this +has to do with basically if you read the + + align:start position:0% +has to do with basically if you read the + + + align:start position:0% +has to do with basically if you read the +shockley-queisser efficiency limit paper + + align:start position:0% +shockley-queisser efficiency limit paper + + + align:start position:0% +shockley-queisser efficiency limit paper +this is the lifetime that they assumed + + align:start position:0% +this is the lifetime that they assumed + + + align:start position:0% +this is the lifetime that they assumed +was limiting and for silicon this is + + align:start position:0% +was limiting and for silicon this is + + + align:start position:0% +was limiting and for silicon this is +observed like that this is never ever + + align:start position:0% +observed like that this is never ever + + + align:start position:0% +observed like that this is never ever +the limiting factor and a lot of direct + + align:start position:0% +the limiting factor and a lot of direct + + + align:start position:0% +the limiting factor and a lot of direct +band act materials for those of you + + align:start position:0% +band act materials for those of you + + + align:start position:0% +band act materials for those of you +don't know what that is don't worry + + align:start position:0% +don't know what that is don't worry + + + align:start position:0% +don't know what that is don't worry +about it that's often the limiting + + align:start position:0% +about it that's often the limiting + + + align:start position:0% +about it that's often the limiting +factor and it has to do with the + + align:start position:0% +factor and it has to do with the + + + align:start position:0% +factor and it has to do with the +absorption is always equal to the + + align:start position:0% +absorption is always equal to the + + + align:start position:0% +absorption is always equal to the +emissivity in a material for a direct + + align:start position:0% +emissivity in a material for a direct + + + align:start position:0% +emissivity in a material for a direct +bandgap material radiative recombination + + align:start position:0% +bandgap material radiative recombination + + + align:start position:0% +bandgap material radiative recombination +can be an issue right and I'll talk + + align:start position:0% +can be an issue right and I'll talk + + + align:start position:0% +can be an issue right and I'll talk +about that in a second + + align:start position:0% +about that in a second + + + align:start position:0% +about that in a second +and there's also another recombination + + align:start position:0% +and there's also another recombination + + + align:start position:0% +and there's also another recombination +called O'Shay recombination it's not + + align:start position:0% +called O'Shay recombination it's not + + + align:start position:0% +called O'Shay recombination it's not +audre like I thought when I first came + + align:start position:0% +audre like I thought when I first came + + + align:start position:0% +audre like I thought when I first came +here is O'Shea kind of like I don't know + + align:start position:0% +here is O'Shea kind of like I don't know + + + align:start position:0% +here is O'Shea kind of like I don't know +Oh Jay Simpson I guess and its dominant + + align:start position:0% +Oh Jay Simpson I guess and its dominant + + + align:start position:0% +Oh Jay Simpson I guess and its dominant +only under very high injection + + align:start position:0% +only under very high injection + + + align:start position:0% +only under very high injection +conditions or very high doping density + + align:start position:0% +conditions or very high doping density + + + align:start position:0% +conditions or very high doping density +so in your emitter layer where there's + + align:start position:0% +so in your emitter layer where there's + + + align:start position:0% +so in your emitter layer where there's +really really high doping densities + + align:start position:0% +really really high doping densities + + + align:start position:0% +really really high doping densities +you're going to have a lot of Roche + + align:start position:0% +you're going to have a lot of Roche + + + align:start position:0% +you're going to have a lot of Roche +recombination and the last one is + + align:start position:0% +recombination and the last one is + + + align:start position:0% +recombination and the last one is +shockley-read-hall so these are three + + align:start position:0% +shockley-read-hall so these are three + + + align:start position:0% +shockley-read-hall so these are three +guys they came up with this kind of + + align:start position:0% +guys they came up with this kind of + + + align:start position:0% +guys they came up with this kind of +model for how recombination happens in + + align:start position:0% +model for how recombination happens in + + + align:start position:0% +model for how recombination happens in +defective material so materials with + + align:start position:0% +defective material so materials with + + + align:start position:0% +defective material so materials with +levels + + align:start position:0% +levels + + + align:start position:0% +levels +electronic levels in the mid gap and + + align:start position:0% +electronic levels in the mid gap and + + + align:start position:0% +electronic levels in the mid gap and +again these add like parallel resistors + + align:start position:0% +again these add like parallel resistors + + + align:start position:0% +again these add like parallel resistors +so you're always so if you remember back + + align:start position:0% +so you're always so if you remember back + + + align:start position:0% +so you're always so if you remember back +to the the leaky bucket these are your + + align:start position:0% +to the the leaky bucket these are your + + + align:start position:0% +to the the leaky bucket these are your +leaky buckets for diffusion length right + + align:start position:0% +leaky buckets for diffusion length right + + + align:start position:0% +leaky buckets for diffusion length right +you're always limited by your shortest + + align:start position:0% +you're always limited by your shortest + + + align:start position:0% +you're always limited by your shortest +diffusion length or sorry your shortest + + align:start position:0% +diffusion length or sorry your shortest + + + align:start position:0% +diffusion length or sorry your shortest +lifetime and this is often your limiting + + align:start position:0% +lifetime and this is often your limiting + + + align:start position:0% +lifetime and this is often your limiting +lifetime is your shock would be a hog + + align:start position:0% +lifetime is your shock would be a hog + + + align:start position:0% +lifetime is your shock would be a hog +recombination okay silicon okay so + + align:start position:0% +recombination okay silicon okay so + + + align:start position:0% +recombination okay silicon okay so +radiative recombination so you can + + align:start position:0% +radiative recombination so you can + + + align:start position:0% +radiative recombination so you can +probably guess from the name that + + align:start position:0% +probably guess from the name that + + + align:start position:0% +probably guess from the name that +radiative recombination involves the + + align:start position:0% +radiative recombination involves the + + + align:start position:0% +radiative recombination involves the +photon the ability to absorb photons + + align:start position:0% +photon the ability to absorb photons + + + align:start position:0% +photon the ability to absorb photons +also means you have the ability to emit + + align:start position:0% +also means you have the ability to emit + + + align:start position:0% +also means you have the ability to emit +them and so silicon or many + + align:start position:0% +them and so silicon or many + + + align:start position:0% +them and so silicon or many +semiconductors will emit photons when + + align:start position:0% +semiconductors will emit photons when + + + align:start position:0% +semiconductors will emit photons when +you get a recombination event across the + + align:start position:0% +you get a recombination event across the + + + align:start position:0% +you get a recombination event across the +band and when that happens you emit a + + align:start position:0% +band and when that happens you emit a + + + align:start position:0% +band and when that happens you emit a +photon under equilibrium conditions so + + align:start position:0% +photon under equilibrium conditions so + + + align:start position:0% +photon under equilibrium conditions so +equilibrium means no outside excitation + + align:start position:0% +equilibrium means no outside excitation + + + align:start position:0% +equilibrium means no outside excitation +doesn't mean steady-state so this is + + align:start position:0% +doesn't mean steady-state so this is + + + align:start position:0% +doesn't mean steady-state so this is +let's say in the dark you get your + + align:start position:0% +let's say in the dark you get your + + + align:start position:0% +let's say in the dark you get your +recombination rate is equal to your + + align:start position:0% +recombination rate is equal to your + + + align:start position:0% +recombination rate is equal to your +generation right right because it's in + + align:start position:0% +generation right right because it's in + + + align:start position:0% +generation right right because it's in +thermal equilibrium with the area around + + align:start position:0% +thermal equilibrium with the area around + + + align:start position:0% +thermal equilibrium with the area around +it so it's absorbing photons and + + align:start position:0% +it so it's absorbing photons and + + + align:start position:0% +it so it's absorbing photons and +emitting them at the same rate and this + + align:start position:0% +emitting them at the same rate and this + + + align:start position:0% +emitting them at the same rate and this +is equal to B so some material parameter + + align:start position:0% +is equal to B so some material parameter + + + align:start position:0% +is equal to B so some material parameter +times your hole and electron + + align:start position:0% +times your hole and electron + + + align:start position:0% +times your hole and electron +concentration and again under + + align:start position:0% +concentration and again under + + + align:start position:0% +concentration and again under +equilibrium conditions that's equal to + + align:start position:0% +equilibrium conditions that's equal to + + + align:start position:0% +equilibrium conditions that's equal to +your intrinsic carrier concentration + + align:start position:0% +your intrinsic carrier concentration + + + align:start position:0% +your intrinsic carrier concentration +right your NP product is equal to NI + + align:start position:0% +right your NP product is equal to NI + + + align:start position:0% +right your NP product is equal to NI +square now when you shine light on it + + align:start position:0% +square now when you shine light on it + + + align:start position:0% +square now when you shine light on it +your n which is equal to there we go + + align:start position:0% +your n which is equal to there we go + + + align:start position:0% +your n which is equal to there we go +and naught plus Delta n so this is your + + align:start position:0% +and naught plus Delta n so this is your + + + align:start position:0% +and naught plus Delta n so this is your +excited carrier so your excess carriers + + align:start position:0% +excited carrier so your excess carriers + + + align:start position:0% +excited carrier so your excess carriers +so your n now increases and is greater + + align:start position:0% +so your n now increases and is greater + + + align:start position:0% +so your n now increases and is greater +than n sub I and your net recombination + + align:start position:0% +than n sub I and your net recombination + + + align:start position:0% +than n sub I and your net recombination +rate is determined by this equation + + align:start position:0% +rate is determined by this equation + + + align:start position:0% +rate is determined by this equation +right here so BN P minus B ni square so + + align:start position:0% +right here so BN P minus B ni square so + + + align:start position:0% +right here so BN P minus B ni square so +the difference between your equilibrium + + align:start position:0% +the difference between your equilibrium + + + align:start position:0% +the difference between your equilibrium +and your now excited carrier + + align:start position:0% +and your now excited carrier + + + align:start position:0% +and your now excited carrier +concentrations it's a material parameter + + align:start position:0% +concentrations it's a material parameter + + + align:start position:0% +concentrations it's a material parameter +yeah it depends on for silicon I forget + + align:start position:0% +yeah it depends on for silicon I forget + + + align:start position:0% +yeah it depends on for silicon I forget +what's on the next slide it's 10 to the + + align:start position:0% +what's on the next slide it's 10 to the + + + align:start position:0% +what's on the next slide it's 10 to the +minus 15 I don't know for other + + align:start position:0% +minus 15 I don't know for other + + + align:start position:0% +minus 15 I don't know for other +materials but I presume that that would + + align:start position:0% +materials but I presume that that would + + + align:start position:0% +materials but I presume that that would +change + + align:start position:0% +change + + + align:start position:0% +change +probably be a lot higher for other + + align:start position:0% +probably be a lot higher for other + + + align:start position:0% +probably be a lot higher for other +materials and it turns out your + + align:start position:0% +materials and it turns out your + + + align:start position:0% +materials and it turns out your +radiative recombination lifetimes when + + align:start position:0% +radiative recombination lifetimes when + + + align:start position:0% +radiative recombination lifetimes when +you plug these numbers in and you make + + align:start position:0% +you plug these numbers in and you make + + + align:start position:0% +you plug these numbers in and you make +some assumptions about what's really + + align:start position:0% +some assumptions about what's really + + + align:start position:0% +some assumptions about what's really +small compared to each other you get + + align:start position:0% +small compared to each other you get + + + align:start position:0% +small compared to each other you get +these equations here and again this is + + align:start position:0% +these equations here and again this is + + + align:start position:0% +these equations here and again this is +tau is equal to Delta n over R and so + + align:start position:0% +tau is equal to Delta n over R and so + + + align:start position:0% +tau is equal to Delta n over R and so +you get that and now if you look at it + + align:start position:0% +you get that and now if you look at it + + + align:start position:0% +you get that and now if you look at it +for silicon you get B is about two times + + align:start position:0% +for silicon you get B is about two times + + + align:start position:0% +for silicon you get B is about two times +ten to the minus fifteen your Delta n I + + align:start position:0% +ten to the minus fifteen your Delta n I + + + align:start position:0% +ten to the minus fifteen your Delta n I +put or sorry yeah and I determined just + + align:start position:0% +put or sorry yeah and I determined just + + + align:start position:0% +put or sorry yeah and I determined just +was 10 to the 16 some doping + + align:start position:0% +was 10 to the 16 some doping + + + align:start position:0% +was 10 to the 16 some doping +concentration and your radiative + + align:start position:0% +concentration and your radiative + + + align:start position:0% +concentration and your radiative +lifetime is incredibly incredibly long + + align:start position:0% +lifetime is incredibly incredibly long + + + align:start position:0% +lifetime is incredibly incredibly long +about 50 milliseconds and if you + + align:start position:0% +about 50 milliseconds and if you + + + align:start position:0% +about 50 milliseconds and if you +remember from before when I was + + align:start position:0% +remember from before when I was + + + align:start position:0% +remember from before when I was +calculating a generation rate for + + align:start position:0% +calculating a generation rate for + + + align:start position:0% +calculating a generation rate for +silicon we used about 10 microseconds so + + align:start position:0% +silicon we used about 10 microseconds so + + + align:start position:0% +silicon we used about 10 microseconds so +this is really really long and so radio + + align:start position:0% +this is really really long and so radio + + + align:start position:0% +this is really really long and so radio +recombination is very very slow and it's + + align:start position:0% +recombination is very very slow and it's + + + align:start position:0% +recombination is very very slow and it's +rarely ever the limiting lifetime in + + align:start position:0% +rarely ever the limiting lifetime in + + + align:start position:0% +rarely ever the limiting lifetime in +silicon based solar cells however as as + + align:start position:0% +silicon based solar cells however as as + + + align:start position:0% +silicon based solar cells however as as +you mentioned earlier it's actually a + + align:start position:0% +you mentioned earlier it's actually a + + + align:start position:0% +you mentioned earlier it's actually a +big problem in direct bandgap materials + + align:start position:0% +big problem in direct bandgap materials + + + align:start position:0% +big problem in direct bandgap materials +and if you think of there are some + + align:start position:0% +and if you think of there are some + + + align:start position:0% +and if you think of there are some +materials who actually want a very short + + align:start position:0% +materials who actually want a very short + + + align:start position:0% +materials who actually want a very short +radiative recombination time so for + + align:start position:0% +radiative recombination time so for + + + align:start position:0% +radiative recombination time so for +example if you're trying to make an LED + + align:start position:0% +example if you're trying to make an LED + + + align:start position:0% +example if you're trying to make an LED +you inject carriers using a voltage that + + align:start position:0% +you inject carriers using a voltage that + + + align:start position:0% +you inject carriers using a voltage that +recombination emits photons and then you + + align:start position:0% +recombination emits photons and then you + + + align:start position:0% +recombination emits photons and then you +get light and that's basically how an + + align:start position:0% +get light and that's basically how an + + + align:start position:0% +get light and that's basically how an +LED works so okay so now we'll talk + + align:start position:0% +LED works so okay so now we'll talk + + + align:start position:0% +LED works so okay so now we'll talk +about a little bit shockley-read-hall + + align:start position:0% +about a little bit shockley-read-hall + + + align:start position:0% +about a little bit shockley-read-hall +recombination so this is something that + + align:start position:0% +recombination so this is something that + + + align:start position:0% +recombination so this is something that +our lab works I think very very well in + + align:start position:0% +our lab works I think very very well in + + + align:start position:0% +our lab works I think very very well in +we do a lot of like defects and + + align:start position:0% +we do a lot of like defects and + + + align:start position:0% +we do a lot of like defects and +semiconductors specifically iron and so + + align:start position:0% +semiconductors specifically iron and so + + + align:start position:0% +semiconductors specifically iron and so +iron is one of these really really awful + + align:start position:0% +iron is one of these really really awful + + + align:start position:0% +iron is one of these really really awful +contaminants and solar cells just a + + align:start position:0% +contaminants and solar cells just a + + + align:start position:0% +contaminants and solar cells just a +little bit of iron I think Tony Craig + + align:start position:0% +little bit of iron I think Tony Craig + + + align:start position:0% +little bit of iron I think Tony Craig +Miller I think I don't remember what + + align:start position:0% +Miller I think I don't remember what + + + align:start position:0% +Miller I think I don't remember what +year production this was maybe it was + + align:start position:0% +year production this was maybe it was + + + align:start position:0% +year production this was maybe it was +2009 but 2 grams of iron could + + align:start position:0% +2009 but 2 grams of iron could + + + align:start position:0% +2009 but 2 grams of iron could +contaminate the entire year supply of + + align:start position:0% +contaminate the entire year supply of + + + align:start position:0% +contaminate the entire year supply of +silicon detrimental e so that's a lot + + align:start position:0% +silicon detrimental e so that's a lot + + + align:start position:0% +silicon detrimental e so that's a lot +yes you do for a single panel and you'll + + align:start position:0% +yes you do for a single panel and you'll + + + align:start position:0% +yes you do for a single panel and you'll +it shocked me anyhow so basically we're + + align:start position:0% +it shocked me anyhow so basically we're + + + align:start position:0% +it shocked me anyhow so basically we're +trying to say here is that you have iron + + align:start position:0% +trying to say here is that you have iron + + + align:start position:0% +trying to say here is that you have iron +atoms and it can sit in different areas + + align:start position:0% +atoms and it can sit in different areas + + + align:start position:0% +atoms and it can sit in different areas +of your lattice but you have these + + align:start position:0% +of your lattice but you have these + + + align:start position:0% +of your lattice but you have these +defects that + + align:start position:0% +defects that + + + align:start position:0% +defects that +exist and they introduce different + + align:start position:0% +exist and they introduce different + + + align:start position:0% +exist and they introduce different +energy levels within the bandgap right + + align:start position:0% +energy levels within the bandgap right + + + align:start position:0% +energy levels within the bandgap right +so the outer electrons of iron can + + align:start position:0% +so the outer electrons of iron can + + + align:start position:0% +so the outer electrons of iron can +either sit at these sites so these blue + + align:start position:0% +either sit at these sites so these blue + + + align:start position:0% +either sit at these sites so these blue +sites were their donors or they can + + align:start position:0% +sites were their donors or they can + + + align:start position:0% +sites were their donors or they can +create acceptor States kind of like + + align:start position:0% +create acceptor States kind of like + + + align:start position:0% +create acceptor States kind of like +boron does but they're much higher up + + align:start position:0% +boron does but they're much higher up + + + align:start position:0% +boron does but they're much higher up +into the gap and these act as + + align:start position:0% +into the gap and these act as + + + align:start position:0% +into the gap and these act as +recombination centers and we'll talk + + align:start position:0% +recombination centers and we'll talk + + + align:start position:0% +recombination centers and we'll talk +about why that is in a second + + align:start position:0% + + + + align:start position:0% + +so these trap levels can interact with + + align:start position:0% +so these trap levels can interact with + + + align:start position:0% +so these trap levels can interact with +mobile carriers in a whole bunch of + + align:start position:0% +mobile carriers in a whole bunch of + + + align:start position:0% +mobile carriers in a whole bunch of +different ways okay it can capture an + + align:start position:0% +different ways okay it can capture an + + + align:start position:0% +different ways okay it can capture an +electron that electron can then sit + + align:start position:0% +electron that electron can then sit + + + align:start position:0% +electron that electron can then sit +there if there's enough heat energy it + + align:start position:0% +there if there's enough heat energy it + + + align:start position:0% +there if there's enough heat energy it +might actually get promoted and jump out + + align:start position:0% +might actually get promoted and jump out + + + align:start position:0% +might actually get promoted and jump out +of that and then which case it wouldn't + + align:start position:0% +of that and then which case it wouldn't + + + align:start position:0% +of that and then which case it wouldn't +have actually decreased your excess + + align:start position:0% +have actually decreased your excess + + + align:start position:0% +have actually decreased your excess +carrier population it can also capture + + align:start position:0% +carrier population it can also capture + + + align:start position:0% +carrier population it can also capture +holes and they can also emit holes and + + align:start position:0% +holes and they can also emit holes and + + + align:start position:0% +holes and they can also emit holes and +there's a bunch of things that go into + + align:start position:0% +there's a bunch of things that go into + + + align:start position:0% +there's a bunch of things that go into +these equations here it depends on a lot + + align:start position:0% +these equations here it depends on a lot + + + align:start position:0% +these equations here it depends on a lot +of the energy of this trap state it + + align:start position:0% +of the energy of this trap state it + + + align:start position:0% +of the energy of this trap state it +depends on the carrier excitation we'll + + align:start position:0% +depends on the carrier excitation we'll + + + align:start position:0% +depends on the carrier excitation we'll +talk about that another few slides and + + align:start position:0% +talk about that another few slides and + + + align:start position:0% +talk about that another few slides and +it also depends on these kind of what + + align:start position:0% +it also depends on these kind of what + + + align:start position:0% +it also depends on these kind of what +are like effective I forget the exact + + align:start position:0% +are like effective I forget the exact + + + align:start position:0% +are like effective I forget the exact +word of the effective hole and electron + + align:start position:0% +word of the effective hole and electron + + + align:start position:0% +word of the effective hole and electron +lifetimes and those are limited by your + + align:start position:0% +lifetimes and those are limited by your + + + align:start position:0% +lifetimes and those are limited by your +trap density so these are can be thought + + align:start position:0% +trap density so these are can be thought + + + align:start position:0% +trap density so these are can be thought +of suppose that each let's say each iron + + align:start position:0% +of suppose that each let's say each iron + + + align:start position:0% +of suppose that each let's say each iron +atom is introducing one trap level it + + align:start position:0% +atom is introducing one trap level it + + + align:start position:0% +atom is introducing one trap level it +would be the number of trap levels the + + align:start position:0% +would be the number of trap levels the + + + align:start position:0% +would be the number of trap levels the +density of trap levels within your + + align:start position:0% +density of trap levels within your + + + align:start position:0% +density of trap levels within your +system times some thermal energy so and + + align:start position:0% +system times some thermal energy so and + + + align:start position:0% +system times some thermal energy so and +then a capture cross section which is + + align:start position:0% +then a capture cross section which is + + + align:start position:0% +then a capture cross section which is +saying okay that trap state exists in + + align:start position:0% +saying okay that trap state exists in + + + align:start position:0% +saying okay that trap state exists in +one location kind of how much area can + + align:start position:0% +one location kind of how much area can + + + align:start position:0% +one location kind of how much area can +it see in terms of what effective area + + align:start position:0% +it see in terms of what effective area + + + align:start position:0% +it see in terms of what effective area +is at capturing electrons and and + + align:start position:0% +is at capturing electrons and and + + + align:start position:0% +is at capturing electrons and and +oftentimes at an under the right + + align:start position:0% +oftentimes at an under the right + + + align:start position:0% +oftentimes at an under the right +conditions so with very very deep traps + + align:start position:0% +conditions so with very very deep traps + + + align:start position:0% +conditions so with very very deep traps +so traps mid gap under low injections + + align:start position:0% +so traps mid gap under low injections + + + align:start position:0% +so traps mid gap under low injections +your shocker recall recombination is + + align:start position:0% +your shocker recall recombination is + + + align:start position:0% +your shocker recall recombination is +actually one of those two lifetimes and + + align:start position:0% +actually one of those two lifetimes and + + + align:start position:0% +actually one of those two lifetimes and +it's a very simple equation in under + + align:start position:0% +it's a very simple equation in under + + + align:start position:0% +it's a very simple equation in under +very very high injection conditions it's + + align:start position:0% +very very high injection conditions it's + + + align:start position:0% +very very high injection conditions it's +actually summing them up and if you look + + align:start position:0% +actually summing them up and if you look + + + align:start position:0% +actually summing them up and if you look +in the previous slide if you go to Delta + + align:start position:0% +in the previous slide if you go to Delta + + + align:start position:0% +in the previous slide if you go to Delta +n goes to infinity you can see that this + + align:start position:0% +n goes to infinity you can see that this + + + align:start position:0% +n goes to infinity you can see that this +becomes true + + align:start position:0% + + + + align:start position:0% + +that's a good question that would be my + + align:start position:0% +that's a good question that would be my + + + align:start position:0% +that's a good question that would be my +guess + + align:start position:0% +guess + + + align:start position:0% +guess +yeah sorry there's another question back + + align:start position:0% +yeah sorry there's another question back + + + align:start position:0% +yeah sorry there's another question back +there or like I can Hank so then it is + + align:start position:0% +there or like I can Hank so then it is + + + align:start position:0% +there or like I can Hank so then it is +iron it were stupid or worse still Oh in + + align:start position:0% +iron it were stupid or worse still Oh in + + + align:start position:0% +iron it were stupid or worse still Oh in +terms of capture cross-section yeah I + + align:start position:0% +terms of capture cross-section yeah I + + + align:start position:0% +terms of capture cross-section yeah I +know they're both bad really bad i Tonio + + align:start position:0% +know they're both bad really bad i Tonio + + + align:start position:0% +know they're both bad really bad i Tonio +do you know that off the top your head + + align:start position:0% +do you know that off the top your head + + + align:start position:0% +do you know that off the top your head +I'm sure so gold is gold has a larger + + align:start position:0% +I'm sure so gold is gold has a larger + + + align:start position:0% +I'm sure so gold is gold has a larger +life ending at that lower concentration + + align:start position:0% +life ending at that lower concentration + + + align:start position:0% +life ending at that lower concentration +since iron it's perhaps one of the worst + + align:start position:0% +since iron it's perhaps one of the worst + + + align:start position:0% +since iron it's perhaps one of the worst +and that's why you're not allowed to + + align:start position:0% +and that's why you're not allowed to + + + align:start position:0% +and that's why you're not allowed to +wear old jewelry leaders they ask you to + + align:start position:0% +wear old jewelry leaders they ask you to + + + align:start position:0% +wear old jewelry leaders they ask you to +take off your high end ears okay so no + + align:start position:0% +take off your high end ears okay so no + + + align:start position:0% +take off your high end ears okay so no +bling in the cleaner there you go + + align:start position:0% +bling in the cleaner there you go + + + align:start position:0% +bling in the cleaner there you go +and so for the material scientists and + + align:start position:0% +and so for the material scientists and + + + align:start position:0% +and so for the material scientists and +physicists in the room if that does not + + align:start position:0% +physicists in the room if that does not + + + align:start position:0% +physicists in the room if that does not +apply to you don't worry this is just to + + align:start position:0% +apply to you don't worry this is just to + + + align:start position:0% +apply to you don't worry this is just to +explain what's going on + + align:start position:0% +explain what's going on + + + align:start position:0% +explain what's going on +often when you want recombination to it + + align:start position:0% +often when you want recombination to it + + + align:start position:0% +often when you want recombination to it +happen so this is a momentum or K versus + + align:start position:0% +happen so this is a momentum or K versus + + + align:start position:0% +happen so this is a momentum or K versus +energy it requires not only the emission + + align:start position:0% +energy it requires not only the emission + + + align:start position:0% +energy it requires not only the emission +of a photon but also a phonon to change + + align:start position:0% +of a photon but also a phonon to change + + + align:start position:0% +of a photon but also a phonon to change +its momentum when you introduce a trap + + align:start position:0% +its momentum when you introduce a trap + + + align:start position:0% +its momentum when you introduce a trap +level are these localized impurities + + align:start position:0% +level are these localized impurities + + + align:start position:0% +level are these localized impurities +because it's localized in real space its + + align:start position:0% +because it's localized in real space its + + + align:start position:0% +because it's localized in real space its +delocalized in k space so you have this + + align:start position:0% +delocalized in k space so you have this + + + align:start position:0% +delocalized in k space so you have this +kind of flat level and k and you have + + align:start position:0% +kind of flat level and k and you have + + + align:start position:0% +kind of flat level and k and you have +these very very efficient pathways for + + align:start position:0% +these very very efficient pathways for + + + align:start position:0% +these very very efficient pathways for +recombination if that doesn't resonate + + align:start position:0% +recombination if that doesn't resonate + + + align:start position:0% +recombination if that doesn't resonate +with you don't worry about it right now + + align:start position:0% +with you don't worry about it right now + + + align:start position:0% +with you don't worry about it right now +so okay so here we see that really the + + align:start position:0% +so okay so here we see that really the + + + align:start position:0% +so okay so here we see that really the +impurities can have a very very large + + align:start position:0% +impurities can have a very very large + + + align:start position:0% +impurities can have a very very large +effect if you think of the doping + + align:start position:0% +effect if you think of the doping + + + align:start position:0% +effect if you think of the doping +densities that we put in we've been + + align:start position:0% +densities that we put in we've been + + + align:start position:0% +densities that we put in we've been +using about 10 to the 15 10 to the 16 + + align:start position:0% +using about 10 to the 15 10 to the 16 + + + align:start position:0% +using about 10 to the 15 10 to the 16 +for our dopant densities this is on the + + align:start position:0% +for our dopant densities this is on the + + + align:start position:0% +for our dopant densities this is on the +order of like a million less and it can + + align:start position:0% +order of like a million less and it can + + + align:start position:0% +order of like a million less and it can +have a huge impact on lifetime so one of + + align:start position:0% +have a huge impact on lifetime so one of + + + align:start position:0% +have a huge impact on lifetime so one of +the worst again as we said was ion and + + align:start position:0% +the worst again as we said was ion and + + + align:start position:0% +the worst again as we said was ion and +these interstitial irons are especially + + align:start position:0% +these interstitial irons are especially + + + align:start position:0% +these interstitial irons are especially +bad and that tend to the I don't know it + + align:start position:0% +bad and that tend to the I don't know it + + + align:start position:0% +bad and that tend to the I don't know it +looks like 10 to the 11 + + align:start position:0% +looks like 10 to the 11 + + + align:start position:0% +looks like 10 to the 11 +very very low concentrations that's one + + align:start position:0% +very very low concentrations that's one + + + align:start position:0% +very very low concentrations that's one +in 10 to the 12 so that's one in a + + align:start position:0% +in 10 to the 12 so that's one in a + + + align:start position:0% +in 10 to the 12 so that's one in a +trillion atoms or iron can detrimental + + align:start position:0% +trillion atoms or iron can detrimental + + + align:start position:0% +trillion atoms or iron can detrimental +impact your solar cell so that's really + + align:start position:0% +impact your solar cell so that's really + + + align:start position:0% +impact your solar cell so that's really +really bad so keeping fabs clean so + + align:start position:0% +really bad so keeping fabs clean so + + + align:start position:0% +really bad so keeping fabs clean so +again no jewelry and other things can + + align:start position:0% +again no jewelry and other things can + + + align:start position:0% +again no jewelry and other things can +really that can actually have a very + + align:start position:0% +really that can actually have a very + + + align:start position:0% +really that can actually have a very +large effect on your device performance + + align:start position:0% +large effect on your device performance + + + align:start position:0% +large effect on your device performance +and if you plot that versus your + + align:start position:0% +and if you plot that versus your + + + align:start position:0% +and if you plot that versus your +dislocation density you can see that if + + align:start position:0% +dislocation density you can see that if + + + align:start position:0% +dislocation density you can see that if +you have it's especially bad for very + + align:start position:0% +you have it's especially bad for very + + + align:start position:0% +you have it's especially bad for very +very high lifetime silicon just a few + + align:start position:0% +very high lifetime silicon just a few + + + align:start position:0% +very high lifetime silicon just a few +dislocations can actually really really + + align:start position:0% +dislocations can actually really really + + + align:start position:0% +dislocations can actually really really +hurt it but the effect is mitigated if + + align:start position:0% +hurt it but the effect is mitigated if + + + align:start position:0% +hurt it but the effect is mitigated if +you're already starting with very low + + align:start position:0% +you're already starting with very low + + + align:start position:0% +you're already starting with very low +lifetime so again and again this is + + align:start position:0% +lifetime so again and again this is + + + align:start position:0% +lifetime so again and again this is +something our lab works on quite + + align:start position:0% +something our lab works on quite + + + align:start position:0% +something our lab works on quite +extensively is it's not just the number + + align:start position:0% +extensively is it's not just the number + + + align:start position:0% +extensively is it's not just the number +of iron atoms so if you take a piece of + + align:start position:0% +of iron atoms so if you take a piece of + + + align:start position:0% +of iron atoms so if you take a piece of +silicon and you want to know its + + align:start position:0% +silicon and you want to know its + + + align:start position:0% +silicon and you want to know its +lifetime or how iron impacts is lifetime + + align:start position:0% +lifetime or how iron impacts is lifetime + + + align:start position:0% +lifetime or how iron impacts is lifetime +it's not just a total number of iron + + align:start position:0% +it's not just a total number of iron + + + align:start position:0% +it's not just a total number of iron +atoms in it it's also how they're + + align:start position:0% +atoms in it it's also how they're + + + align:start position:0% +atoms in it it's also how they're +distributed so if you have let's say + + align:start position:0% +distributed so if you have let's say + + + align:start position:0% +distributed so if you have let's say +clusters of iron atoms that would count + + align:start position:0% +clusters of iron atoms that would count + + + align:start position:0% +clusters of iron atoms that would count +as one defect or effectively less than + + align:start position:0% +as one defect or effectively less than + + + align:start position:0% +as one defect or effectively less than +the number of atoms in it and so + + align:start position:0% +the number of atoms in it and so + + + align:start position:0% +the number of atoms in it and so +clustering these things can actually be + + align:start position:0% +clustering these things can actually be + + + align:start position:0% +clustering these things can actually be +really really a good way of cleaning up + + align:start position:0% +really really a good way of cleaning up + + + align:start position:0% +really really a good way of cleaning up +your your solar cell material and this + + align:start position:0% +your your solar cell material and this + + + align:start position:0% +your your solar cell material and this +is an effect called gettering and if you + + align:start position:0% +is an effect called gettering and if you + + + align:start position:0% +is an effect called gettering and if you +can kind of get are these impurity atoms + + align:start position:0% +can kind of get are these impurity atoms + + + align:start position:0% +can kind of get are these impurity atoms +into one location they'll have less of a + + align:start position:0% +into one location they'll have less of a + + + align:start position:0% +into one location they'll have less of a +detrimental impact on your material so + + align:start position:0% +detrimental impact on your material so + + + align:start position:0% +detrimental impact on your material so +this is kind of a tricky one to explain + + align:start position:0% +this is kind of a tricky one to explain + + + align:start position:0% +this is kind of a tricky one to explain +but this is a so shockley-read-hall + + align:start position:0% +but this is a so shockley-read-hall + + + align:start position:0% +but this is a so shockley-read-hall +recombination can also show up in + + align:start position:0% +recombination can also show up in + + + align:start position:0% +recombination can also show up in +something called surface recombination + + align:start position:0% +something called surface recombination + + + align:start position:0% +something called surface recombination +so if you look at your silicon lattice + + align:start position:0% +so if you look at your silicon lattice + + + align:start position:0% +so if you look at your silicon lattice +each silicon atom has four valence + + align:start position:0% +each silicon atom has four valence + + + align:start position:0% +each silicon atom has four valence +electrons and it bonds to four silicon + + align:start position:0% +electrons and it bonds to four silicon + + + align:start position:0% +electrons and it bonds to four silicon +atoms around it and it has satisfied + + align:start position:0% +atoms around it and it has satisfied + + + align:start position:0% +atoms around it and it has satisfied +covalent bonds so this silicon atom has + + align:start position:0% +covalent bonds so this silicon atom has + + + align:start position:0% +covalent bonds so this silicon atom has +all its bond satisfied all its bonds + + align:start position:0% +all its bond satisfied all its bonds + + + align:start position:0% +all its bond satisfied all its bonds +satisfied until you get to the surface + + align:start position:0% +satisfied until you get to the surface + + + align:start position:0% +satisfied until you get to the surface +and at the surface you have what are + + align:start position:0% +and at the surface you have what are + + + align:start position:0% +and at the surface you have what are +called dangling bonds and these dangling + + align:start position:0% +called dangling bonds and these dangling + + + align:start position:0% +called dangling bonds and these dangling +bonds can actually introduce trap States + + align:start position:0% +bonds can actually introduce trap States + + + align:start position:0% +bonds can actually introduce trap States +and you can see that it actually + + align:start position:0% +and you can see that it actually + + + align:start position:0% +and you can see that it actually +introduces a whole ton of levels within + + align:start position:0% +introduces a whole ton of levels within + + + align:start position:0% +introduces a whole ton of levels within +the bandgap that can provide + + align:start position:0% +the bandgap that can provide + + + align:start position:0% +the bandgap that can provide +shockley-read-hall recombination + + align:start position:0% +shockley-read-hall recombination + + + align:start position:0% +shockley-read-hall recombination +pathways for your carriers means the + + align:start position:0% +pathways for your carriers means the + + + align:start position:0% +pathways for your carriers means the +surfaces are incredibly important + + align:start position:0% +surfaces are incredibly important + + + align:start position:0% +surfaces are incredibly important +and the way we tend to think of it and + + align:start position:0% +and the way we tend to think of it and + + + align:start position:0% +and the way we tend to think of it and +this is kind of a concept that might be + + align:start position:0% +this is kind of a concept that might be + + + align:start position:0% +this is kind of a concept that might be +difficult to grasp at first but it + + align:start position:0% +difficult to grasp at first but it + + + align:start position:0% +difficult to grasp at first but it +scales with two things there's two + + align:start position:0% +scales with two things there's two + + + align:start position:0% +scales with two things there's two +things going on you can think of that + + align:start position:0% +things going on you can think of that + + + align:start position:0% +things going on you can think of that +this is the width of your cell and you + + align:start position:0% +this is the width of your cell and you + + + align:start position:0% +this is the width of your cell and you +have some surface recombination velocity + + align:start position:0% +have some surface recombination velocity + + + align:start position:0% +have some surface recombination velocity +which is some kind of characteristic of + + align:start position:0% +which is some kind of characteristic of + + + align:start position:0% +which is some kind of characteristic of +how well they can recombine at the + + align:start position:0% +how well they can recombine at the + + + align:start position:0% +how well they can recombine at the +surface + + align:start position:0% +surface + + + align:start position:0% +surface +and let's say infinite surface + + align:start position:0% +and let's say infinite surface + + + align:start position:0% +and let's say infinite surface +recombination velocities it means that + + align:start position:0% +recombination velocities it means that + + + align:start position:0% +recombination velocities it means that +any carrier that comes and hits that + + align:start position:0% +any carrier that comes and hits that + + + align:start position:0% +any carrier that comes and hits that +surface will most surely recombine so + + align:start position:0% +surface will most surely recombine so + + + align:start position:0% +surface will most surely recombine so +this drops to zero so then you're + + align:start position:0% +this drops to zero so then you're + + + align:start position:0% +this drops to zero so then you're +limited by okay how well can they + + align:start position:0% +limited by okay how well can they + + + align:start position:0% +limited by okay how well can they +actually diffuse to your surface so it's + + align:start position:0% +actually diffuse to your surface so it's + + + align:start position:0% +actually diffuse to your surface so it's +it's again some kind of ratio of your + + align:start position:0% +it's again some kind of ratio of your + + + align:start position:0% +it's again some kind of ratio of your +cell thickness squared over the + + align:start position:0% +cell thickness squared over the + + + align:start position:0% +cell thickness squared over the +diffusivity or carrier diffusivity and + + align:start position:0% +diffusivity or carrier diffusivity and + + + align:start position:0% +diffusivity or carrier diffusivity and +that that gives you an idea of what your + + align:start position:0% +that that gives you an idea of what your + + + align:start position:0% +that that gives you an idea of what your +limiting factors are so under very low + + align:start position:0% +limiting factors are so under very low + + + align:start position:0% +limiting factors are so under very low +surface recombination velocities you're + + align:start position:0% +surface recombination velocities you're + + + align:start position:0% +surface recombination velocities you're +limited by this term here the first one + + align:start position:0% +limited by this term here the first one + + + align:start position:0% +limited by this term here the first one +and under very high ones you're limited + + align:start position:0% +and under very high ones you're limited + + + align:start position:0% +and under very high ones you're limited +by this term and so there's two kind of + + align:start position:0% +by this term and so there's two kind of + + + align:start position:0% +by this term and so there's two kind of +effects going on there and it's + + align:start position:0% +effects going on there and it's + + + align:start position:0% +effects going on there and it's +summarized as well here it at at very + + align:start position:0% +summarized as well here it at at very + + + align:start position:0% +summarized as well here it at at very +very low service recombination + + align:start position:0% +very low service recombination + + + align:start position:0% +very low service recombination +velocities your house surfaces almost + + align:start position:0% +velocities your house surfaces almost + + + align:start position:0% +velocities your house surfaces almost +goes to infinity very high and you can + + align:start position:0% +goes to infinity very high and you can + + + align:start position:0% +goes to infinity very high and you can +passivate these bonds using hydrogen so + + align:start position:0% +passivate these bonds using hydrogen so + + + align:start position:0% +passivate these bonds using hydrogen so +for example if you use hydrofluoric acid + + align:start position:0% +for example if you use hydrofluoric acid + + + align:start position:0% +for example if you use hydrofluoric acid +what it does is it edges away the + + align:start position:0% +what it does is it edges away the + + + align:start position:0% +what it does is it edges away the +silicon oxide layer that sits there and + + align:start position:0% +silicon oxide layer that sits there and + + + align:start position:0% +silicon oxide layer that sits there and +you have these hydrogen atoms then now + + align:start position:0% +you have these hydrogen atoms then now + + + align:start position:0% +you have these hydrogen atoms then now +sit and satisfy these bombs and if + + align:start position:0% +sit and satisfy these bombs and if + + + align:start position:0% +sit and satisfy these bombs and if +they're perfectly satisfied you'll have + + align:start position:0% +they're perfectly satisfied you'll have + + + align:start position:0% +they're perfectly satisfied you'll have +a mobile carrier it'll actually + + align:start position:0% +a mobile carrier it'll actually + + + align:start position:0% +a mobile carrier it'll actually +elastically scattered off not lose any + + align:start position:0% +elastically scattered off not lose any + + + align:start position:0% +elastically scattered off not lose any +energy and not recombine through these + + align:start position:0% +energy and not recombine through these + + + align:start position:0% +energy and not recombine through these +trap States yeah + + align:start position:0% + + + + align:start position:0% + +what is if you if you actually I've seen + + align:start position:0% +what is if you if you actually I've seen + + + align:start position:0% +what is if you if you actually I've seen +some diagrams of what silicon oxide + + align:start position:0% +some diagrams of what silicon oxide + + + align:start position:0% +some diagrams of what silicon oxide +looks like on silicon it passivates many + + align:start position:0% +looks like on silicon it passivates many + + + align:start position:0% +looks like on silicon it passivates many +of the bonds you're absolutely right HF + + align:start position:0% +of the bonds you're absolutely right HF + + + align:start position:0% +of the bonds you're absolutely right HF +is actually probably the best the + + align:start position:0% +is actually probably the best the + + + align:start position:0% +is actually probably the best the +problem is that it etches glass and + + align:start position:0% +problem is that it etches glass and + + + align:start position:0% +problem is that it etches glass and +other things that are in your solar cell + + align:start position:0% +other things that are in your solar cell + + + align:start position:0% +other things that are in your solar cell +material and it's incredibly dangerous + + align:start position:0% +material and it's incredibly dangerous + + + align:start position:0% +material and it's incredibly dangerous +it can kill you rather dramatically so + + align:start position:0% +it can kill you rather dramatically so + + + align:start position:0% +it can kill you rather dramatically so +it's only used in laboratory settings if + + align:start position:0% +it's only used in laboratory settings if + + + align:start position:0% +it's only used in laboratory settings if +you're trying to actually take lifetime + + align:start position:0% +you're trying to actually take lifetime + + + align:start position:0% +you're trying to actually take lifetime +measurements and negate the effect of + + align:start position:0% +measurements and negate the effect of + + + align:start position:0% +measurements and negate the effect of +surface recombination silicon oxide can + + align:start position:0% +surface recombination silicon oxide can + + + align:start position:0% +surface recombination silicon oxide can +be a good one if you actually look at + + align:start position:0% +be a good one if you actually look at + + + align:start position:0% +be a good one if you actually look at +the structure there's a few dangling + + align:start position:0% +the structure there's a few dangling + + + align:start position:0% +the structure there's a few dangling +bonds within there but it can passivate + + align:start position:0% +bonds within there but it can passivate + + + align:start position:0% +bonds within there but it can passivate +most of them just not all of them + + align:start position:0% +most of them just not all of them + + + align:start position:0% +most of them just not all of them +another good passivation technique is + + align:start position:0% +another good passivation technique is + + + align:start position:0% +another good passivation technique is +actually the silicon nitride AARC coding + + align:start position:0% +actually the silicon nitride AARC coding + + + align:start position:0% +actually the silicon nitride AARC coding +it passivates the surface very well so + + align:start position:0% +it passivates the surface very well so + + + align:start position:0% +it passivates the surface very well so +yeah good question and there's other + + align:start position:0% +yeah good question and there's other + + + align:start position:0% +yeah good question and there's other +ways to mitigate surface recombination + + align:start position:0% +ways to mitigate surface recombination + + + align:start position:0% +ways to mitigate surface recombination +so we'll talk about that I think in + + align:start position:0% +so we'll talk about that I think in + + + align:start position:0% +so we'll talk about that I think in +either next lecture or the one after + + align:start position:0% +either next lecture or the one after + + + align:start position:0% +either next lecture or the one after +that so so yeah this slide is just + + align:start position:0% +that so so yeah this slide is just + + + align:start position:0% +that so so yeah this slide is just +telling us that if we bury our thickness + + align:start position:0% +telling us that if we bury our thickness + + + align:start position:0% +telling us that if we bury our thickness +of our silicon we can actually measure + + align:start position:0% +of our silicon we can actually measure + + + align:start position:0% +of our silicon we can actually measure +our service recombination velocity and + + align:start position:0% +our service recombination velocity and + + + align:start position:0% +our service recombination velocity and +we can fit it so we can figure out our + + align:start position:0% +we can fit it so we can figure out our + + + align:start position:0% +we can fit it so we can figure out our +tau surface which is really important + + align:start position:0% +tau surface which is really important + + + align:start position:0% +tau surface which is really important +material parameter generally I think + + align:start position:0% +material parameter generally I think + + + align:start position:0% +material parameter generally I think +good surface recombination velocities or + + align:start position:0% +good surface recombination velocities or + + + align:start position:0% +good surface recombination velocities or +anywhere from like 10 to maybe in the + + align:start position:0% +anywhere from like 10 to maybe in the + + + align:start position:0% +anywhere from like 10 to maybe in the +hundreds for centimeters per second and + + align:start position:0% +hundreds for centimeters per second and + + + align:start position:0% +hundreds for centimeters per second and +really bad ones are much much higher + + align:start position:0% + + + + align:start position:0% + +okay and the last type of recombination + + align:start position:0% +okay and the last type of recombination + + + align:start position:0% +okay and the last type of recombination +mechanism we're gonna talk about today + + align:start position:0% +mechanism we're gonna talk about today + + + align:start position:0% +mechanism we're gonna talk about today +is o.j recombination and this looks like + + align:start position:0% +is o.j recombination and this looks like + + + align:start position:0% +is o.j recombination and this looks like +when I first saw this I'm like why on + + align:start position:0% +when I first saw this I'm like why on + + + align:start position:0% +when I first saw this I'm like why on +earth would this ever happen and the + + align:start position:0% +earth would this ever happen and the + + + align:start position:0% +earth would this ever happen and the +fact is it doesn't until you get to very + + align:start position:0% +fact is it doesn't until you get to very + + + align:start position:0% +fact is it doesn't until you get to very +very high carrier concentrations so you + + align:start position:0% +very high carrier concentrations so you + + + align:start position:0% +very high carrier concentrations so you +can see that it involves three particles + + align:start position:0% +can see that it involves three particles + + + align:start position:0% +can see that it involves three particles +let's say an n-type silicon it needs two + + align:start position:0% +let's say an n-type silicon it needs two + + + align:start position:0% +let's say an n-type silicon it needs two +electrons and a hole what happens is is + + align:start position:0% +electrons and a hole what happens is is + + + align:start position:0% +electrons and a hole what happens is is +that you get the simultaneous relaxation + + align:start position:0% +that you get the simultaneous relaxation + + + align:start position:0% +that you get the simultaneous relaxation +and excitation so you get this + + align:start position:0% +and excitation so you get this + + + align:start position:0% +and excitation so you get this +relaxation of this excited electron into + + align:start position:0% +relaxation of this excited electron into + + + align:start position:0% +relaxation of this excited electron into +a hole and then you get this + + align:start position:0% +a hole and then you get this + + + align:start position:0% +a hole and then you get this +excitation of this other electron into a + + align:start position:0% +excitation of this other electron into a + + + align:start position:0% +excitation of this other electron into a +higher energy state and then it thermal + + align:start position:0% +higher energy state and then it thermal + + + align:start position:0% +higher energy state and then it thermal +ices down in releases of phonon releases + + align:start position:0% +ices down in releases of phonon releases + + + align:start position:0% +ices down in releases of phonon releases +heat yeah Jessica so this is going to be + + align:start position:0% +heat yeah Jessica so this is going to be + + + align:start position:0% +heat yeah Jessica so this is going to be +our n-type material and again because + + align:start position:0% +our n-type material and again because + + + align:start position:0% +our n-type material and again because +this type of recombination event + + align:start position:0% +this type of recombination event + + + align:start position:0% +this type of recombination event +requires two particles it requires two + + align:start position:0% +requires two particles it requires two + + + align:start position:0% +requires two particles it requires two +electrons so it's N squared in one hole + + align:start position:0% +electrons so it's N squared in one hole + + + align:start position:0% +electrons so it's N squared in one hole +so the recombination rate goes up with P + + align:start position:0% +so the recombination rate goes up with P + + + align:start position:0% +so the recombination rate goes up with P +N squared at high enough concentrations + + align:start position:0% +N squared at high enough concentrations + + + align:start position:0% +N squared at high enough concentrations +and so your towel goes up with the one + + align:start position:0% +and so your towel goes up with the one + + + align:start position:0% +and so your towel goes up with the one +over N squared and this is particularly + + align:start position:0% +over N squared and this is particularly + + + align:start position:0% +over N squared and this is particularly +bad again only at very because it goes + + align:start position:0% +bad again only at very because it goes + + + align:start position:0% +bad again only at very because it goes +up with a square of the carrier + + align:start position:0% +up with a square of the carrier + + + align:start position:0% +up with a square of the carrier +concentration it's really bad at a very + + align:start position:0% +concentration it's really bad at a very + + + align:start position:0% +concentration it's really bad at a very +high carrier concentration so if we look + + align:start position:0% +high carrier concentration so if we look + + + align:start position:0% +high carrier concentration so if we look +at this plot we can see that our + + align:start position:0% +at this plot we can see that our + + + align:start position:0% +at this plot we can see that our +minority carrier lifetime drops well + + align:start position:0% +minority carrier lifetime drops well + + + align:start position:0% +minority carrier lifetime drops well +below a microsecond around 10 to the 18 + + align:start position:0% +below a microsecond around 10 to the 18 + + + align:start position:0% +below a microsecond around 10 to the 18 +so you generally want to stay out of + + align:start position:0% +so you generally want to stay out of + + + align:start position:0% +so you generally want to stay out of +that range of doping concentrations in + + align:start position:0% +that range of doping concentrations in + + + align:start position:0% +that range of doping concentrations in +your base because you'll have very very + + align:start position:0% +your base because you'll have very very + + + align:start position:0% +your base because you'll have very very +bad lifetimes + + align:start position:0% + + + + align:start position:0% + +sorry this is our didn't label this + + align:start position:0% +sorry this is our didn't label this + + + align:start position:0% +sorry this is our didn't label this +you're right this is the valence band + + align:start position:0% +you're right this is the valence band + + + align:start position:0% +you're right this is the valence band +that's the conduction band okay all + + align:start position:0% +that's the conduction band okay all + + + align:start position:0% +that's the conduction band okay all +right and so this is kind of driving + + align:start position:0% +right and so this is kind of driving + + + align:start position:0% +right and so this is kind of driving +home again that leaky bucket idea is + + align:start position:0% +home again that leaky bucket idea is + + + align:start position:0% +home again that leaky bucket idea is +that you're really limited by your worst + + align:start position:0% +that you're really limited by your worst + + + align:start position:0% +that you're really limited by your worst +lifetime and so if you remember what + + align:start position:0% +lifetime and so if you remember what + + + align:start position:0% +lifetime and so if you remember what +we're thinking about parallel circuits + + align:start position:0% +we're thinking about parallel circuits + + + align:start position:0% +we're thinking about parallel circuits +here your bulk or your effective + + align:start position:0% +here your bulk or your effective + + + align:start position:0% +here your bulk or your effective +lifetime of each carrier is determined + + align:start position:0% +lifetime of each carrier is determined + + + align:start position:0% +lifetime of each carrier is determined +by these three here your radiative sorry + + align:start position:0% +by these three here your radiative sorry + + + align:start position:0% +by these three here your radiative sorry +that should be a band which is the same + + align:start position:0% +that should be a band which is the same + + + align:start position:0% +that should be a band which is the same +as your radiative recombination O'Shay + + align:start position:0% +as your radiative recombination O'Shay + + + align:start position:0% +as your radiative recombination O'Shay +in chocolate Reed Hall and so in + + align:start position:0% +in chocolate Reed Hall and so in + + + align:start position:0% +in chocolate Reed Hall and so in +different excess carrier densities so + + align:start position:0% +different excess carrier densities so + + + align:start position:0% +different excess carrier densities so +we're varying Delta n by shining various + + align:start position:0% +we're varying Delta n by shining various + + + align:start position:0% +we're varying Delta n by shining various +intensities of light and we can kind of + + align:start position:0% +intensities of light and we can kind of + + + align:start position:0% +intensities of light and we can kind of +activate different limiting lifetimes so + + align:start position:0% +activate different limiting lifetimes so + + + align:start position:0% +activate different limiting lifetimes so +it very low you're a limited by + + align:start position:0% +it very low you're a limited by + + + align:start position:0% +it very low you're a limited by +shockley-read-hall and Chakra Greenhalgh + + align:start position:0% +shockley-read-hall and Chakra Greenhalgh + + + align:start position:0% +shockley-read-hall and Chakra Greenhalgh +can actually go down with higher + + align:start position:0% +can actually go down with higher + + + align:start position:0% +can actually go down with higher +illumination conditions and your O'Shay + + align:start position:0% +illumination conditions and your O'Shay + + + align:start position:0% +illumination conditions and your O'Shay +remember against really really bad + + align:start position:0% +remember against really really bad + + + align:start position:0% +remember against really really bad +around 10 to the 18 becomes your + + align:start position:0% +around 10 to the 18 becomes your + + + align:start position:0% +around 10 to the 18 becomes your +limiting so your tell bulk is always + + align:start position:0% +limiting so your tell bulk is always + + + align:start position:0% +limiting so your tell bulk is always +doing is never doing better than your + + align:start position:0% +doing is never doing better than your + + + align:start position:0% +doing is never doing better than your +worst lifetime hello Jay this came out + + align:start position:0% +worst lifetime hello Jay this came out + + + align:start position:0% +worst lifetime hello Jay this came out +of Dana MacDonald's thesis talam it er + + align:start position:0% +of Dana MacDonald's thesis talam it er + + + align:start position:0% +of Dana MacDonald's thesis talam it er +is it's complicated because it has other + + align:start position:0% +is it's complicated because it has other + + + align:start position:0% +is it's complicated because it has other +influences in it Oh Jay I always think + + align:start position:0% +influences in it Oh Jay I always think + + + align:start position:0% +influences in it Oh Jay I always think +of recombination in the emitter is Oh + + align:start position:0% +of recombination in the emitter is Oh + + + align:start position:0% +of recombination in the emitter is Oh +Jay but you also have other carriers + + align:start position:0% +Jay but you also have other carriers + + + align:start position:0% +Jay but you also have other carriers +coming in due to injection currents + + align:start position:0% +coming in due to injection currents + + + align:start position:0% +coming in due to injection currents +right or and so your excess carrier + + align:start position:0% +right or and so your excess carrier + + + align:start position:0% +right or and so your excess carrier +population is also a function of that + + align:start position:0% +population is also a function of that + + + align:start position:0% +population is also a function of that +and so the equation for it gets a little + + align:start position:0% +and so the equation for it gets a little + + + align:start position:0% +and so the equation for it gets a little +more complicated but it would make sense + + align:start position:0% +more complicated but it would make sense + + + align:start position:0% +more complicated but it would make sense +that as you increase illumination you're + + align:start position:0% +that as you increase illumination you're + + + align:start position:0% +that as you increase illumination you're +increasing your your current into the + + align:start position:0% +increasing your your current into the + + + align:start position:0% +increasing your your current into the +emitter and you would get more carriers + + align:start position:0% +emitter and you would get more carriers + + + align:start position:0% +emitter and you would get more carriers +and it would decrease and it looks + + align:start position:0% +and it would decrease and it looks + + + align:start position:0% +and it would decrease and it looks +almost exactly like Oh Jay in this in + + align:start position:0% +almost exactly like Oh Jay in this in + + + align:start position:0% +almost exactly like Oh Jay in this in +this regime over here I'm not sure the + + align:start position:0% +this regime over here I'm not sure the + + + align:start position:0% +this regime over here I'm not sure the +other things that go into it but if you + + align:start position:0% +other things that go into it but if you + + + align:start position:0% +other things that go into it but if you +look up as theses I think it gives a + + align:start position:0% +look up as theses I think it gives a + + + align:start position:0% +look up as theses I think it gives a +pretty good description okay so you're + + align:start position:0% +pretty good description okay so you're + + + align:start position:0% +pretty good description okay so you're +probably bored of hearing me say this + + align:start position:0% +probably bored of hearing me say this + + + align:start position:0% +probably bored of hearing me say this +but again it's we're always limited by + + align:start position:0% +but again it's we're always limited by + + + align:start position:0% +but again it's we're always limited by +our weakest so in defect mitigated + + align:start position:0% +our weakest so in defect mitigated + + + align:start position:0% +our weakest so in defect mitigated +recombination material so we're + + align:start position:0% +recombination material so we're + + + align:start position:0% +recombination material so we're +the your shortest lifetime is due to + + align:start position:0% +the your shortest lifetime is due to + + + align:start position:0% +the your shortest lifetime is due to +some kind of shockley-read-hall + + align:start position:0% +some kind of shockley-read-hall + + + align:start position:0% +some kind of shockley-read-hall +recombination it's always your lifetime + + align:start position:0% +recombination it's always your lifetime + + + align:start position:0% +recombination it's always your lifetime +for shockley-read-hall is always going + + align:start position:0% +for shockley-read-hall is always going + + + align:start position:0% +for shockley-read-hall is always going +to be much much shorter than your + + align:start position:0% +to be much much shorter than your + + + align:start position:0% +to be much much shorter than your +radiative lifetimes which is a + + align:start position:0% +radiative lifetimes which is a + + + align:start position:0% +radiative lifetimes which is a +characteristic we can exploit for + + align:start position:0% +characteristic we can exploit for + + + align:start position:0% +characteristic we can exploit for +measuring the lifetimes of our materials + + align:start position:0% +measuring the lifetimes of our materials + + + align:start position:0% +measuring the lifetimes of our materials +so because very very few carriers will + + align:start position:0% +so because very very few carriers will + + + align:start position:0% +so because very very few carriers will +actually radiatively recombine and emit + + align:start position:0% +actually radiatively recombine and emit + + + align:start position:0% +actually radiatively recombine and emit +a photon that if more of them are ready + + align:start position:0% +a photon that if more of them are ready + + + align:start position:0% +a photon that if more of them are ready +to leak recombining then we know that + + align:start position:0% +to leak recombining then we know that + + + align:start position:0% +to leak recombining then we know that +it's a very high lifetime material if + + align:start position:0% +it's a very high lifetime material if + + + align:start position:0% +it's a very high lifetime material if +there's a lot of defects and we have + + align:start position:0% +there's a lot of defects and we have + + + align:start position:0% +there's a lot of defects and we have +very very short lifetimes very few of + + align:start position:0% +very very short lifetimes very few of + + + align:start position:0% +very very short lifetimes very few of +them will radiatively recombine and so + + align:start position:0% +them will radiatively recombine and so + + + align:start position:0% +them will radiatively recombine and so +this emission of photons with energy at + + align:start position:0% +this emission of photons with energy at + + + align:start position:0% +this emission of photons with energy at +the bandgap it can kind of give us an + + align:start position:0% +the bandgap it can kind of give us an + + + align:start position:0% +the bandgap it can kind of give us an +idea of the lifetime within our material + + align:start position:0% +idea of the lifetime within our material + + + align:start position:0% +idea of the lifetime within our material +and that's how we measure it's a + + align:start position:0% +and that's how we measure it's a + + + align:start position:0% +and that's how we measure it's a +technique called photo luminescence and + + align:start position:0% +technique called photo luminescence and + + + align:start position:0% +technique called photo luminescence and +what you do is you shine light on it + + align:start position:0% +what you do is you shine light on it + + + align:start position:0% +what you do is you shine light on it +generally with a laser we put a diffuser + + align:start position:0% +generally with a laser we put a diffuser + + + align:start position:0% +generally with a laser we put a diffuser +in front of the laser so the laser beam + + align:start position:0% +in front of the laser so the laser beam + + + align:start position:0% +in front of the laser so the laser beam +spreads its photons over a large area we + + align:start position:0% +spreads its photons over a large area we + + + align:start position:0% +spreads its photons over a large area we +excite all these carriers so this laser + + align:start position:0% +excite all these carriers so this laser + + + align:start position:0% +excite all these carriers so this laser +has very very short wavelengths and I + + align:start position:0% +has very very short wavelengths and I + + + align:start position:0% +has very very short wavelengths and I +think in our very short it's 900 + + align:start position:0% +think in our very short it's 900 + + + align:start position:0% +think in our very short it's 900 +nanometers + + align:start position:0% +nanometers + + + align:start position:0% +nanometers +silicon's bandgap corresponds to about + + align:start position:0% +silicon's bandgap corresponds to about + + + align:start position:0% +silicon's bandgap corresponds to about +1108 nanometers and so 900 is easily + + align:start position:0% +1108 nanometers and so 900 is easily + + + align:start position:0% +1108 nanometers and so 900 is easily +absorbed not just right near the emitter + + align:start position:0% +absorbed not just right near the emitter + + + align:start position:0% +absorbed not just right near the emitter +but also somewhat well deep into the + + align:start position:0% +but also somewhat well deep into the + + + align:start position:0% +but also somewhat well deep into the +below the junction as well and then as + + align:start position:0% +below the junction as well and then as + + + align:start position:0% +below the junction as well and then as +we begin to see recombination when + + align:start position:0% +we begin to see recombination when + + + align:start position:0% +we begin to see recombination when +radiative recombination happens we emit + + align:start position:0% +radiative recombination happens we emit + + + align:start position:0% +radiative recombination happens we emit +a photon and that can happen in certain + + align:start position:0% +a photon and that can happen in certain + + + align:start position:0% +a photon and that can happen in certain +areas better than others and it a lot of + + align:start position:0% +areas better than others and it a lot of + + + align:start position:0% +areas better than others and it a lot of +it depends on like I said defect density + + align:start position:0% +it depends on like I said defect density + + + align:start position:0% +it depends on like I said defect density +and other lifetime limiting defects and + + align:start position:0% +and other lifetime limiting defects and + + + align:start position:0% +and other lifetime limiting defects and +it's a good way to kind of like + + align:start position:0% +it's a good way to kind of like + + + align:start position:0% +it's a good way to kind of like +spatially locate where problems are in + + align:start position:0% +spatially locate where problems are in + + + align:start position:0% +spatially locate where problems are in +your solar cell any other questions that + + align:start position:0% + + + + align:start position:0% + +it depends on your camera right so we + + align:start position:0% +it depends on your camera right so we + + + align:start position:0% +it depends on your camera right so we +use I think a germanium camera to detect + + align:start position:0% +use I think a germanium camera to detect + + + align:start position:0% +use I think a germanium camera to detect +those photons because silicon won't have + + align:start position:0% +those photons because silicon won't have + + + align:start position:0% +those photons because silicon won't have +a very good response and yeah it depends + + align:start position:0% +a very good response and yeah it depends + + + align:start position:0% +a very good response and yeah it depends +on the CCD array within your camera it + + align:start position:0% +on the CCD array within your camera it + + + align:start position:0% +on the CCD array within your camera it +can be really good I do a similar + + align:start position:0% +can be really good I do a similar + + + align:start position:0% +can be really good I do a similar +technique to measure shunts and we have + + align:start position:0% +technique to measure shunts and we have + + + align:start position:0% +technique to measure shunts and we have +a microscope objective we just have to + + align:start position:0% +a microscope objective we just have to + + + align:start position:0% +a microscope objective we just have to +zoom in really really far and then we + + align:start position:0% +zoom in really really far and then we + + + align:start position:0% +zoom in really really far and then we +just scan over an area okay and last + + align:start position:0% +just scan over an area okay and last + + + align:start position:0% +just scan over an area okay and last +little thing is that if you recall let + + align:start position:0% +little thing is that if you recall let + + + align:start position:0% +little thing is that if you recall let +me this slide traps can not only trap an + + align:start position:0% +me this slide traps can not only trap an + + + align:start position:0% +me this slide traps can not only trap an +electron but you can also emit an + + align:start position:0% +electron but you can also emit an + + + align:start position:0% +electron but you can also emit an +electron assuming it has enough thermal + + align:start position:0% +electron assuming it has enough thermal + + + align:start position:0% +electron assuming it has enough thermal +energy and you can see that on this plot + + align:start position:0% +energy and you can see that on this plot + + + align:start position:0% +energy and you can see that on this plot +and so this is an Arrhenius plot so + + align:start position:0% +and so this is an Arrhenius plot so + + + align:start position:0% +and so this is an Arrhenius plot so +again + + align:start position:0% +again + + + align:start position:0% +again +high temperatures aren't this direction + + align:start position:0% +high temperatures aren't this direction + + + align:start position:0% +high temperatures aren't this direction +low temperature over here and you can + + align:start position:0% +low temperature over here and you can + + + align:start position:0% +low temperature over here and you can +see that your lifetime actually + + align:start position:0% +see that your lifetime actually + + + align:start position:0% +see that your lifetime actually +increases at higher temperatures because + + align:start position:0% +increases at higher temperatures because + + + align:start position:0% +increases at higher temperatures because +electrons that see that trap fall into + + align:start position:0% +electrons that see that trap fall into + + + align:start position:0% +electrons that see that trap fall into +it then can easily come back out of it + + align:start position:0% +it then can easily come back out of it + + + align:start position:0% +it then can easily come back out of it +because they have enough thermal energy + + align:start position:0% +because they have enough thermal energy + + + align:start position:0% +because they have enough thermal energy +to escape and that's really what this is + + align:start position:0% +to escape and that's really what this is + + + align:start position:0% +to escape and that's really what this is +depicting so what one of the things I + + align:start position:0% +depicting so what one of the things I + + + align:start position:0% +depicting so what one of the things I +think for researchers in the room who + + align:start position:0% +think for researchers in the room who + + + align:start position:0% +think for researchers in the room who +are studying these types of materials + + align:start position:0% +are studying these types of materials + + + align:start position:0% +are studying these types of materials +varying temperature is often a really + + align:start position:0% +varying temperature is often a really + + + align:start position:0% +varying temperature is often a really +really good way of looking at electronic + + align:start position:0% +really good way of looking at electronic + + + align:start position:0% +really good way of looking at electronic +structure of materials and it can be + + align:start position:0% +structure of materials and it can be + + + align:start position:0% +structure of materials and it can be +very very powerful and this is one + + align:start position:0% +very very powerful and this is one + + + align:start position:0% +very very powerful and this is one +example of a tool to look at this kind + + align:start position:0% +example of a tool to look at this kind + + + align:start position:0% +example of a tool to look at this kind +of these types of traps okay oh good we + + align:start position:0% +of these types of traps okay oh good we + + + align:start position:0% +of these types of traps okay oh good we +have plenty of time we actually might + + align:start position:0% +have plenty of time we actually might + + + align:start position:0% +have plenty of time we actually might +end early + + align:start position:0% +end early + + + align:start position:0% +end early +okay so now we're going to talk about + + align:start position:0% +okay so now we're going to talk about + + + align:start position:0% +okay so now we're going to talk about +mobility we've given a lot of sorry + + align:start position:0% + + + + align:start position:0% + +that's that's a good question so + + align:start position:0% +that's that's a good question so + + + align:start position:0% +that's that's a good question so +phosphorus actually has if you draw it + + align:start position:0% +phosphorus actually has if you draw it + + + align:start position:0% +phosphorus actually has if you draw it +on an E versus X diagram so if we have + + align:start position:0% +on an E versus X diagram so if we have + + + align:start position:0% +on an E versus X diagram so if we have +our conduction band here our valence + + align:start position:0% +our conduction band here our valence + + + align:start position:0% +our conduction band here our valence +band here we said iron put states in the + + align:start position:0% +band here we said iron put states in the + + + align:start position:0% +band here we said iron put states in the +middle of the gap phosphorus and boron + + align:start position:0% +middle of the gap phosphorus and boron + + + align:start position:0% +middle of the gap phosphorus and boron +actually put States very very very close + + align:start position:0% +actually put States very very very close + + + align:start position:0% +actually put States very very very close +to the valence band conduction band if + + align:start position:0% +to the valence band conduction band if + + + align:start position:0% +to the valence band conduction band if +you go to low enough temperature so + + align:start position:0% +you go to low enough temperature so + + + align:start position:0% +you go to low enough temperature so +let's say you know below 100 Kelvin you + + align:start position:0% +let's say you know below 100 Kelvin you + + + align:start position:0% +let's say you know below 100 Kelvin you +can actually freeze out those donor + + align:start position:0% +can actually freeze out those donor + + + align:start position:0% +can actually freeze out those donor +electrons onto the phosphorous atoms and + + align:start position:0% +electrons onto the phosphorous atoms and + + + align:start position:0% +electrons onto the phosphorous atoms and +below certain concentrations of + + align:start position:0% +below certain concentrations of + + + align:start position:0% +below certain concentrations of +phosphorus atoms for example so below + + align:start position:0% +phosphorus atoms for example so below + + + align:start position:0% +phosphorus atoms for example so below +like 10 to the 18 at 0 Kelvin you cannot + + align:start position:0% +like 10 to the 18 at 0 Kelvin you cannot + + + align:start position:0% +like 10 to the 18 at 0 Kelvin you cannot +conduct electricity it actually becomes + + align:start position:0% +conduct electricity it actually becomes + + + align:start position:0% +conduct electricity it actually becomes +a total insulator this is an excellent + + align:start position:0% +a total insulator this is an excellent + + + align:start position:0% +a total insulator this is an excellent +question but at room temperature when + + align:start position:0% +question but at room temperature when + + + align:start position:0% +question but at room temperature when +Katy is on the order so Katy is your + + align:start position:0% +Katy is on the order so Katy is your + + + align:start position:0% +Katy is on the order so Katy is your +thermal energy and at room temperature + + align:start position:0% +thermal energy and at room temperature + + + align:start position:0% +thermal energy and at room temperature +if you put that 4 electrons + + align:start position:0% +if you put that 4 electrons + + + align:start position:0% +if you put that 4 electrons +it's 0.026 electron volts or 26 milli + + align:start position:0% +it's 0.026 electron volts or 26 milli + + + align:start position:0% +it's 0.026 electron volts or 26 milli +electron volts this is a good number to + + align:start position:0% +electron volts this is a good number to + + + align:start position:0% +electron volts this is a good number to +have in mind by the way when that number + + align:start position:0% +have in mind by the way when that number + + + align:start position:0% +have in mind by the way when that number +is on the order of this binding energy + + align:start position:0% +is on the order of this binding energy + + + align:start position:0% +is on the order of this binding energy +for phosphorous they're almost always + + align:start position:0% +for phosphorous they're almost always + + + align:start position:0% +for phosphorous they're almost always +fully ionized and free but that's a very + + align:start position:0% +fully ionized and free but that's a very + + + align:start position:0% +fully ionized and free but that's a very +good question + + align:start position:0% + + + + align:start position:0% + +alright alright so if we remember our + + align:start position:0% +alright alright so if we remember our + + + align:start position:0% +alright alright so if we remember our +definition of mobility it's related to + + align:start position:0% +definition of mobility it's related to + + + align:start position:0% +definition of mobility it's related to +our diffusivity and again our mobility + + align:start position:0% +our diffusivity and again our mobility + + + align:start position:0% +our diffusivity and again our mobility +is saying how well these excited charges + + align:start position:0% +is saying how well these excited charges + + + align:start position:0% +is saying how well these excited charges +can move around and it's also related + + align:start position:0% +can move around and it's also related + + + align:start position:0% +can move around and it's also related +how much thermal energy these charges + + align:start position:0% +how much thermal energy these charges + + + align:start position:0% +how much thermal energy these charges +have so that's why we have this KB T + + align:start position:0% +have so that's why we have this KB T + + + align:start position:0% +have so that's why we have this KB T +factor and what's plotted on the right + + align:start position:0% +factor and what's plotted on the right + + + align:start position:0% +factor and what's plotted on the right +is the Shocker quasar efficiency limit + + align:start position:0% +is the Shocker quasar efficiency limit + + + align:start position:0% +is the Shocker quasar efficiency limit +which are those stars and then how if + + align:start position:0% +which are those stars and then how if + + + align:start position:0% +which are those stars and then how if +you let's say you reduce your mobility + + align:start position:0% +you let's say you reduce your mobility + + + align:start position:0% +you let's say you reduce your mobility +by let's say a factor of 10 or 100 + + align:start position:0% +by let's say a factor of 10 or 100 + + + align:start position:0% +by let's say a factor of 10 or 100 +what's the impact on the overall + + align:start position:0% +what's the impact on the overall + + + align:start position:0% +what's the impact on the overall +efficiency and you can see that if you + + align:start position:0% +efficiency and you can see that if you + + + align:start position:0% +efficiency and you can see that if you +detrimental impacts your mobility you + + align:start position:0% +detrimental impacts your mobility you + + + align:start position:0% +detrimental impacts your mobility you +can really have a large effect on your + + align:start position:0% +can really have a large effect on your + + + align:start position:0% +can really have a large effect on your +diffusion length and it can really hurt + + align:start position:0% +diffusion length and it can really hurt + + + align:start position:0% +diffusion length and it can really hurt +your device performance so it's really + + align:start position:0% +your device performance so it's really + + + align:start position:0% +your device performance so it's really +important material parameter to think + + align:start position:0% +important material parameter to think + + + align:start position:0% +important material parameter to think +about okay so there's lots of ways that + + align:start position:0% +about okay so there's lots of ways that + + + align:start position:0% +about okay so there's lots of ways that +these mobile electrons can do what's + + align:start position:0% +these mobile electrons can do what's + + + align:start position:0% +these mobile electrons can do what's +called scattering so if I'm mobile + + align:start position:0% +called scattering so if I'm mobile + + + align:start position:0% +called scattering so if I'm mobile +electron I'm moving down through the + + align:start position:0% +electron I'm moving down through the + + + align:start position:0% +electron I'm moving down through the +silicon lattice and let's say I see a + + align:start position:0% +silicon lattice and let's say I see a + + + align:start position:0% +silicon lattice and let's say I see a +defect and this defect because it has + + align:start position:0% +defect and this defect because it has + + + align:start position:0% +defect and this defect because it has +these extra electrons it creates this + + align:start position:0% +these extra electrons it creates this + + + align:start position:0% +these extra electrons it creates this +kind of area of charge it can see that + + align:start position:0% +kind of area of charge it can see that + + + align:start position:0% +kind of area of charge it can see that +it can scatter off of it and lose its + + align:start position:0% +it can scatter off of it and lose its + + + align:start position:0% +it can scatter off of it and lose its +energy and so that's called a scattering + + align:start position:0% +energy and so that's called a scattering + + + align:start position:0% +energy and so that's called a scattering +event and that can well not really lose + + align:start position:0% +event and that can well not really lose + + + align:start position:0% +event and that can well not really lose +its energy sorry it'll change direction + + align:start position:0% +its energy sorry it'll change direction + + + align:start position:0% +its energy sorry it'll change direction +it kind of impacts the the movement of + + align:start position:0% +it kind of impacts the the movement of + + + align:start position:0% +it kind of impacts the the movement of +that carrier and there's all sorts of + + align:start position:0% +that carrier and there's all sorts of + + + align:start position:0% +that carrier and there's all sorts of +other defects scattering mechanisms you + + align:start position:0% +other defects scattering mechanisms you + + + align:start position:0% +other defects scattering mechanisms you +can also scatter with an oscillating + + align:start position:0% +can also scatter with an oscillating + + + align:start position:0% +can also scatter with an oscillating +atom or a phonon that's another type of + + align:start position:0% +atom or a phonon that's another type of + + + align:start position:0% +atom or a phonon that's another type of +scattering mechanism and it's heavily + + align:start position:0% +scattering mechanism and it's heavily + + + align:start position:0% +scattering mechanism and it's heavily +dependent on what you put into your + + align:start position:0% +dependent on what you put into your + + + align:start position:0% +dependent on what you put into your +material and we'll talk about that in a + + align:start position:0% +material and we'll talk about that in a + + + align:start position:0% +material and we'll talk about that in a +second + + align:start position:0% +second + + + align:start position:0% +second +and for a lot of materials that are + + align:start position:0% +and for a lot of materials that are + + + align:start position:0% +and for a lot of materials that are +let's say porous or amorphous in some + + align:start position:0% +let's say porous or amorphous in some + + + align:start position:0% +let's say porous or amorphous in some +way or even a lot of like let's say + + align:start position:0% +way or even a lot of like let's say + + + align:start position:0% +way or even a lot of like let's say +organic semiconductors having a good + + align:start position:0% +organic semiconductors having a good + + + align:start position:0% +organic semiconductors having a good +percolation Network is really important + + align:start position:0% +percolation Network is really important + + + align:start position:0% +percolation Network is really important +to transport these charges and often + + align:start position:0% +to transport these charges and often + + + align:start position:0% +to transport these charges and often +it's a very limiting factor and let's + + align:start position:0% +it's a very limiting factor and let's + + + align:start position:0% +it's a very limiting factor and let's +say like organic photovoltaics so this + + align:start position:0% +say like organic photovoltaics so this + + + align:start position:0% +say like organic photovoltaics so this +is a relatively simple scattering + + align:start position:0% +is a relatively simple scattering + + + align:start position:0% +is a relatively simple scattering +mechanism we appointed himself + + align:start position:0% +mechanism we appointed himself + + + align:start position:0% +mechanism we appointed himself +what's going on here is that we can see + + align:start position:0% +what's going on here is that we can see + + + align:start position:0% +what's going on here is that we can see +that as we add carriers so this is and + + align:start position:0% +that as we add carriers so this is and + + + align:start position:0% +that as we add carriers so this is and +it's ten to the 14th very very low + + align:start position:0% +it's ten to the 14th very very low + + + align:start position:0% +it's ten to the 14th very very low +concentration of dopants as we increase + + align:start position:0% +concentration of dopants as we increase + + + align:start position:0% +concentration of dopants as we increase +the number of carriers are scattering + + align:start position:0% +the number of carriers are scattering + + + align:start position:0% +the number of carriers are scattering +off of those ionized impurities so every + + align:start position:0% +off of those ionized impurities so every + + + align:start position:0% +off of those ionized impurities so every +time you add a phosphorus atom let's say + + align:start position:0% +time you add a phosphorus atom let's say + + + align:start position:0% +time you add a phosphorus atom let's say +you introduce a static positive charge + + align:start position:0% +you introduce a static positive charge + + + align:start position:0% +you introduce a static positive charge +and a mobile negative charge when that + + align:start position:0% +and a mobile negative charge when that + + + align:start position:0% +and a mobile negative charge when that +electron leaves and so you now have all + + align:start position:0% +electron leaves and so you now have all + + + align:start position:0% +electron leaves and so you now have all +of these scattering centers of positive + + align:start position:0% +of these scattering centers of positive + + + align:start position:0% +of these scattering centers of positive +charge and so as you increase the number + + align:start position:0% +charge and so as you increase the number + + + align:start position:0% +charge and so as you increase the number +of dopants this is for silicon you + + align:start position:0% +of dopants this is for silicon you + + + align:start position:0% +of dopants this is for silicon you +decrease the mobility of your of your + + align:start position:0% +decrease the mobility of your of your + + + align:start position:0% +decrease the mobility of your of your +material and it's also greatly a + + align:start position:0% +material and it's also greatly a + + + align:start position:0% +material and it's also greatly a +function of temperature I think that's + + align:start position:0% +function of temperature I think that's + + + align:start position:0% +function of temperature I think that's +mostly due to either phonon scattering + + align:start position:0% +mostly due to either phonon scattering + + + align:start position:0% +mostly due to either phonon scattering +that right there's there any other + + align:start position:0% +that right there's there any other + + + align:start position:0% +that right there's there any other +mechanism I'm missing Tonio + + align:start position:0% + + + + align:start position:0% + +but importantly is that higher + + align:start position:0% +but importantly is that higher + + + align:start position:0% +but importantly is that higher +temperatures you may generally get a + + align:start position:0% +temperatures you may generally get a + + + align:start position:0% +temperatures you may generally get a +much lower lower mobility and again + + align:start position:0% +much lower lower mobility and again + + + align:start position:0% +much lower lower mobility and again +hitting home for this is not sure + + align:start position:0% +hitting home for this is not sure + + + align:start position:0% +hitting home for this is not sure +necessarily for silicon but for a lot of + + align:start position:0% +necessarily for silicon but for a lot of + + + align:start position:0% +necessarily for silicon but for a lot of +like these hetero Junction devices so + + align:start position:0% +like these hetero Junction devices so + + + align:start position:0% +like these hetero Junction devices so +for example organics have very very low + + align:start position:0% +for example organics have very very low + + + align:start position:0% +for example organics have very very low +diffusion lengths and a lot of it's + + align:start position:0% +diffusion lengths and a lot of it's + + + align:start position:0% +diffusion lengths and a lot of it's +limited by mobility and so what you do + + align:start position:0% +limited by mobility and so what you do + + + align:start position:0% +limited by mobility and so what you do +is you make these inter digitated P or P + + align:start position:0% +is you make these inter digitated P or P + + + align:start position:0% +is you make these inter digitated P or P +I what I would call PN and I forget the + + align:start position:0% +I what I would call PN and I forget the + + + align:start position:0% +I what I would call PN and I forget the +exact analogy but P and n layers that + + align:start position:0% +exact analogy but P and n layers that + + + align:start position:0% +exact analogy but P and n layers that +inter digitated so that they only have + + align:start position:0% +inter digitated so that they only have + + + align:start position:0% +inter digitated so that they only have +to diffuse not the width of the device + + align:start position:0% +to diffuse not the width of the device + + + align:start position:0% +to diffuse not the width of the device +but the length of those fingers so you + + align:start position:0% +but the length of those fingers so you + + + align:start position:0% +but the length of those fingers so you +effectively need a much shorter + + align:start position:0% +effectively need a much shorter + + + align:start position:0% +effectively need a much shorter +diffusion length and so this is talking + + align:start position:0% +diffusion length and so this is talking + + + align:start position:0% +diffusion length and so this is talking +about some of those other different + + align:start position:0% +about some of those other different + + + align:start position:0% +about some of those other different +ideas and a hetero Junction is two + + align:start position:0% +ideas and a hetero Junction is two + + + align:start position:0% +ideas and a hetero Junction is two +different materials + + align:start position:0% + + + + align:start position:0% + +that's an inter digitated p.m. structure + + align:start position:0% + + + + align:start position:0% + +yeah so what we're gonna be talking + + align:start position:0% +yeah so what we're gonna be talking + + + align:start position:0% +yeah so what we're gonna be talking +about is kind of the products of N and + + align:start position:0% +about is kind of the products of N and + + + align:start position:0% +about is kind of the products of N and +mu and if you recall that your + + align:start position:0% +mu and if you recall that your + + + align:start position:0% +mu and if you recall that your +conductivity so hold on let's go back + + align:start position:0% +conductivity so hold on let's go back + + + align:start position:0% +conductivity so hold on let's go back +what we have here is that we have a + + align:start position:0% + + + + align:start position:0% + +highly doped semiconductor so this is + + align:start position:0% +highly doped semiconductor so this is + + + align:start position:0% +highly doped semiconductor so this is +about 10 to the 16 and then we have our + + align:start position:0% +about 10 to the 16 and then we have our + + + align:start position:0% +about 10 to the 16 and then we have our +intrinsic silicon so this has no dopants + + align:start position:0% +intrinsic silicon so this has no dopants + + + align:start position:0% +intrinsic silicon so this has no dopants +in it whatsoever and now you remember + + align:start position:0% +in it whatsoever and now you remember + + + align:start position:0% +in it whatsoever and now you remember +from last lecture when we applied a + + align:start position:0% +from last lecture when we applied a + + + align:start position:0% +from last lecture when we applied a +voltage across the terminals a current + + align:start position:0% +voltage across the terminals a current + + + align:start position:0% +voltage across the terminals a current +started to flow and when we heat it up + + align:start position:0% +started to flow and when we heat it up + + + align:start position:0% +started to flow and when we heat it up +what had happened your members current + + align:start position:0% +what had happened your members current + + + align:start position:0% +what had happened your members current +increased and that's due to more + + align:start position:0% +increased and that's due to more + + + align:start position:0% +increased and that's due to more +thermally excited carriers and so you're + + align:start position:0% +thermally excited carriers and so you're + + + align:start position:0% +thermally excited carriers and so you're +injured intrinsic carrier concentration + + align:start position:0% +injured intrinsic carrier concentration + + + align:start position:0% +injured intrinsic carrier concentration +goes up right and so your inch what was + + align:start position:0% +goes up right and so your inch what was + + + align:start position:0% +goes up right and so your inch what was +for room temperature what's the + + align:start position:0% +for room temperature what's the + + + align:start position:0% +for room temperature what's the +intrinsic carrier concentration it's + + align:start position:0% +intrinsic carrier concentration it's + + + align:start position:0% +intrinsic carrier concentration it's +about 10 to the 10 and that range and so + + align:start position:0% +about 10 to the 10 and that range and so + + + align:start position:0% +about 10 to the 10 and that range and so +an increase a small increase in + + align:start position:0% +an increase a small increase in + + + align:start position:0% +an increase a small increase in +temperature can greatly increase the + + align:start position:0% +temperature can greatly increase the + + + align:start position:0% +temperature can greatly increase the +intrinsic carrier concentration may be + + align:start position:0% +intrinsic carrier concentration may be + + + align:start position:0% +intrinsic carrier concentration may be +something like 10 to the 12 now in a + + align:start position:0% +something like 10 to the 12 now in a + + + align:start position:0% +something like 10 to the 12 now in a +dope semiconductor is that going to + + align:start position:0% +dope semiconductor is that going to + + + align:start position:0% +dope semiconductor is that going to +affect it as much how about you guys + + align:start position:0% +affect it as much how about you guys + + + align:start position:0% +affect it as much how about you guys +think about that for a little bit + + align:start position:0% +think about that for a little bit + + + align:start position:0% +think about that for a little bit +meet and talk to your neighbor and so + + align:start position:0% +meet and talk to your neighbor and so + + + align:start position:0% +meet and talk to your neighbor and so +I'm going to keep both of these up along + + align:start position:0% +I'm going to keep both of these up along + + + align:start position:0% +I'm going to keep both of these up along +with a high doping concentration and one + + align:start position:0% +with a high doping concentration and one + + + align:start position:0% +with a high doping concentration and one +with a low and which one do you think + + align:start position:0% +with a low and which one do you think + + + align:start position:0% +with a low and which one do you think +will have the highest relative change in + + align:start position:0% +will have the highest relative change in + + + align:start position:0% +will have the highest relative change in +conductivity and in which direction so + + align:start position:0% +conductivity and in which direction so + + + align:start position:0% +conductivity and in which direction so +I'll give you three minutes + + align:start position:0% + + + + align:start position:0% + +okay so we're now going to subject + + align:start position:0% +okay so we're now going to subject + + + align:start position:0% +okay so we're now going to subject +you've seen this demo before we're now + + align:start position:0% +you've seen this demo before we're now + + + align:start position:0% +you've seen this demo before we're now +going to subject our intrinsic carrier + + align:start position:0% +going to subject our intrinsic carrier + + + align:start position:0% +going to subject our intrinsic carrier +to my hairdryer and right now we're + + align:start position:0% +to my hairdryer and right now we're + + + align:start position:0% +to my hairdryer and right now we're +getting let's see it's about 10 micro + + align:start position:0% +getting let's see it's about 10 micro + + + align:start position:0% +getting let's see it's about 10 micro +amps and if we heat this guy out + + align:start position:0% + + + + align:start position:0% + +then mix these two look ah there we go + + align:start position:0% +then mix these two look ah there we go + + + align:start position:0% +then mix these two look ah there we go +okay so you can see we get a rather + + align:start position:0% +okay so you can see we get a rather + + + align:start position:0% +okay so you can see we get a rather +large increase in kind that was up to a + + align:start position:0% +large increase in kind that was up to a + + + align:start position:0% +large increase in kind that was up to a +hundred micro so a factor of ten so + + align:start position:0% +hundred micro so a factor of ten so + + + align:start position:0% +hundred micro so a factor of ten so +quite a large increase okay so let's see + + align:start position:0% +quite a large increase okay so let's see + + + align:start position:0% +quite a large increase okay so let's see +a show of hands so right now we're + + align:start position:0% +a show of hands so right now we're + + + align:start position:0% +a show of hands so right now we're +getting maybe we need to put this on + + align:start position:0% +getting maybe we need to put this on + + + align:start position:0% +getting maybe we need to put this on +milliamps yeah so we're getting about + + align:start position:0% +milliamps yeah so we're getting about + + + align:start position:0% +milliamps yeah so we're getting about +fifty eight milliamps of current through + + align:start position:0% +fifty eight milliamps of current through + + + align:start position:0% +fifty eight milliamps of current through +the semiconductor who thinks that the + + align:start position:0% +the semiconductor who thinks that the + + + align:start position:0% +the semiconductor who thinks that the +currents gonna increase when we add more + + align:start position:0% +currents gonna increase when we add more + + + align:start position:0% +currents gonna increase when we add more +thermal carriers this is for the doped + + align:start position:0% +thermal carriers this is for the doped + + + align:start position:0% +thermal carriers this is for the doped +one we just saw the intrinsic yeah yeah + + align:start position:0% +one we just saw the intrinsic yeah yeah + + + align:start position:0% +one we just saw the intrinsic yeah yeah +what do you think it'll go up the + + align:start position:0% +what do you think it'll go up the + + + align:start position:0% +what do you think it'll go up the +conductivity so this is for the dope + + align:start position:0% +conductivity so this is for the dope + + + align:start position:0% +conductivity so this is for the dope +semiconductor now who thinks it's gonna + + align:start position:0% +semiconductor now who thinks it's gonna + + + align:start position:0% +semiconductor now who thinks it's gonna +stay the same + + align:start position:0% +stay the same + + + align:start position:0% +stay the same +who thinks is gonna go down all right so + + align:start position:0% +who thinks is gonna go down all right so + + + align:start position:0% +who thinks is gonna go down all right so +this is split Wow alright so right now + + align:start position:0% +this is split Wow alright so right now + + + align:start position:0% +this is split Wow alright so right now +we're getting about 57 milliamps and + + align:start position:0% +we're getting about 57 milliamps and + + + align:start position:0% +we're getting about 57 milliamps and +let's heat this guy up and see what + + align:start position:0% +let's heat this guy up and see what + + + align:start position:0% +let's heat this guy up and see what +happens as you can see it's actually + + align:start position:0% +happens as you can see it's actually + + + align:start position:0% +happens as you can see it's actually +going down it's now 52 50 49 so what's + + align:start position:0% +going down it's now 52 50 49 so what's + + + align:start position:0% +going down it's now 52 50 49 so what's +important is that we're measuring + + align:start position:0% +important is that we're measuring + + + align:start position:0% +important is that we're measuring +conductivity it's not only how many + + align:start position:0% +conductivity it's not only how many + + + align:start position:0% +conductivity it's not only how many +carriers we have but also how well they + + align:start position:0% +carriers we have but also how well they + + + align:start position:0% +carriers we have but also how well they +can move around and it's again that + + align:start position:0% +can move around and it's again that + + + align:start position:0% +can move around and it's again that +product of number of carriers comes with + + align:start position:0% +product of number of carriers comes with + + + align:start position:0% +product of number of carriers comes with +mobility and again each of those + + align:start position:0% +mobility and again each of those + + + align:start position:0% +mobility and again each of those +carriers carries an electric charge so + + align:start position:0% +carriers carries an electric charge so + + + align:start position:0% +carriers carries an electric charge so +we put the electric charge of an + + align:start position:0% +we put the electric charge of an + + + align:start position:0% +we put the electric charge of an +electron in front of it oh this is what + + align:start position:0% +electron in front of it oh this is what + + + align:start position:0% +electron in front of it oh this is what +I'm supposed to have up in the + + align:start position:0% +I'm supposed to have up in the + + + align:start position:0% +I'm supposed to have up in the +background while that was happening yeah + + align:start position:0% +background while that was happening yeah + + + align:start position:0% +background while that was happening yeah +so again remember there was huge changes + + align:start position:0% +so again remember there was huge changes + + + align:start position:0% +so again remember there was huge changes +one was measuring milliamps one was + + align:start position:0% +one was measuring milliamps one was + + + align:start position:0% +one was measuring milliamps one was +measuring micro amps so if we look at + + align:start position:0% +measuring micro amps so if we look at + + + align:start position:0% +measuring micro amps so if we look at +room temperature we have about ten to + + align:start position:0% +room temperature we have about ten to + + + align:start position:0% +room temperature we have about ten to +the ten intrinsic carriers right so this + + align:start position:0% +the ten intrinsic carriers right so this + + + align:start position:0% +the ten intrinsic carriers right so this +is for intrinsic silicon with no dopants + + align:start position:0% +is for intrinsic silicon with no dopants + + + align:start position:0% +is for intrinsic silicon with no dopants +whatsoever as we increase the heat even + + align:start position:0% +whatsoever as we increase the heat even + + + align:start position:0% +whatsoever as we increase the heat even +when I don't think we're getting to 500 + + align:start position:0% +when I don't think we're getting to 500 + + + align:start position:0% +when I don't think we're getting to 500 +degrees but let's say we get to 400 + + align:start position:0% +degrees but let's say we get to 400 + + + align:start position:0% +degrees but let's say we get to 400 +we're only going up by a factor of a + + align:start position:0% +we're only going up by a factor of a + + + align:start position:0% +we're only going up by a factor of a +hundred which is substantial right but + + align:start position:0% +hundred which is substantial right but + + + align:start position:0% +hundred which is substantial right but +if we had 10 to the 16 carriers + + align:start position:0% +if we had 10 to the 16 carriers + + + align:start position:0% +if we had 10 to the 16 carriers +originally from our dopants these added + + align:start position:0% +originally from our dopants these added + + + align:start position:0% +originally from our dopants these added +number of intrinsic carrier's aren't + + align:start position:0% +number of intrinsic carrier's aren't + + + align:start position:0% +number of intrinsic carrier's aren't +going to have really much of an effect + + align:start position:0% +going to have really much of an effect + + + align:start position:0% +going to have really much of an effect +at all in terms of the conductivity so + + align:start position:0% +at all in terms of the conductivity so + + + align:start position:0% +at all in terms of the conductivity so +what's really affecting the doped case + + align:start position:0% +what's really affecting the doped case + + + align:start position:0% +what's really affecting the doped case +is that our mobility actually goes to + + align:start position:0% +is that our mobility actually goes to + + + align:start position:0% +is that our mobility actually goes to +with temperature due to these scattering + + align:start position:0% +with temperature due to these scattering + + + align:start position:0% +with temperature due to these scattering +events with temperature and for + + align:start position:0% +events with temperature and for + + + align:start position:0% +events with temperature and for +intrinsic silicon you get a little bit + + align:start position:0% +intrinsic silicon you get a little bit + + + align:start position:0% +intrinsic silicon you get a little bit +better mobility so it's a little bit + + align:start position:0% +better mobility so it's a little bit + + + align:start position:0% +better mobility so it's a little bit +higher but they both have the same + + align:start position:0% +higher but they both have the same + + + align:start position:0% +higher but they both have the same +general trend of lower mobility but only + + align:start position:0% +general trend of lower mobility but only + + + align:start position:0% +general trend of lower mobility but only +by let's say this is about a factor of + + align:start position:0% +by let's say this is about a factor of + + + align:start position:0% +by let's say this is about a factor of +10 where it was about a factor of + + align:start position:0% +10 where it was about a factor of + + + align:start position:0% +10 where it was about a factor of +hundred for the for the intrinsic + + align:start position:0% +hundred for the for the intrinsic + + + align:start position:0% +hundred for the for the intrinsic +carrier so again our carriers and the + + align:start position:0% +carrier so again our carriers and the + + + align:start position:0% +carrier so again our carriers and the +intrinsic case go up by a factor of 100 + + align:start position:0% +intrinsic case go up by a factor of 100 + + + align:start position:0% +intrinsic case go up by a factor of 100 +our mobility goes up by a factor of 10 + + align:start position:0% +our mobility goes up by a factor of 10 + + + align:start position:0% +our mobility goes up by a factor of 10 +so the conductivity then has to increase + + align:start position:0% +so the conductivity then has to increase + + + align:start position:0% +so the conductivity then has to increase +by a factor of 10 and for our dope + + align:start position:0% +by a factor of 10 and for our dope + + + align:start position:0% +by a factor of 10 and for our dope +semiconductor really the heat is just + + align:start position:0% +semiconductor really the heat is just + + + align:start position:0% +semiconductor really the heat is just +hurting our conductivity because of the + + align:start position:0% +hurting our conductivity because of the + + + align:start position:0% +hurting our conductivity because of the +decrease in mobility and the thermal + + align:start position:0% +decrease in mobility and the thermal + + + align:start position:0% +decrease in mobility and the thermal +carriers don't really add they're washed + + align:start position:0% +carriers don't really add they're washed + + + align:start position:0% +carriers don't really add they're washed +out by the the sea of doping atoms that + + align:start position:0% +out by the the sea of doping atoms that + + + align:start position:0% +out by the the sea of doping atoms that +are really adding all the carriers + + align:start position:0% + + + + align:start position:0% + +would you ever want your solar cell that + + align:start position:0% +would you ever want your solar cell that + + + align:start position:0% +would you ever want your solar cell that +hot that's a big question so let's go + + align:start position:0% +hot that's a big question so let's go + + + align:start position:0% +hot that's a big question so let's go +there's an equation for that and we'll + + align:start position:0% +there's an equation for that and we'll + + + align:start position:0% +there's an equation for that and we'll +talk about that later too okay so if you + + align:start position:0% +talk about that later too okay so if you + + + align:start position:0% +talk about that later too okay so if you +look at our vo see if we have a large + + align:start position:0% +look at our vo see if we have a large + + + align:start position:0% +look at our vo see if we have a large +saturation current that means that we're + + align:start position:0% +saturation current that means that we're + + + align:start position:0% +saturation current that means that we're +gonna have a very low vo C right we have + + align:start position:0% +gonna have a very low vo C right we have + + + align:start position:0% +gonna have a very low vo C right we have +this reverse current that's going in the + + align:start position:0% +this reverse current that's going in the + + + align:start position:0% +this reverse current that's going in the +opposite direction of our illumination + + align:start position:0% +opposite direction of our illumination + + + align:start position:0% +opposite direction of our illumination +current that's opposing that + + align:start position:0% +current that's opposing that + + + align:start position:0% +current that's opposing that +illumination current and so if it's + + align:start position:0% +illumination current and so if it's + + + align:start position:0% +illumination current and so if it's +large then it'll hurt our vo C and you + + align:start position:0% +large then it'll hurt our vo C and you + + + align:start position:0% +large then it'll hurt our vo C and you +can see that it scales with D which + + align:start position:0% +can see that it scales with D which + + + align:start position:0% +can see that it scales with D which +scales with KT and so we get this + + align:start position:0% +scales with KT and so we get this + + + align:start position:0% +scales with KT and so we get this +increase in temperature is increasing + + align:start position:0% +increase in temperature is increasing + + + align:start position:0% +increase in temperature is increasing +this J naught and so for most types of + + align:start position:0% +this J naught and so for most types of + + + align:start position:0% +this J naught and so for most types of +cells heat is very very bad especially + + align:start position:0% +cells heat is very very bad especially + + + align:start position:0% +cells heat is very very bad especially +for crystalline silicon for amorphous + + align:start position:0% +for crystalline silicon for amorphous + + + align:start position:0% +for crystalline silicon for amorphous +silicon that's different well I'm not + + align:start position:0% +silicon that's different well I'm not + + + align:start position:0% +silicon that's different well I'm not +gonna get into that today but for a + + align:start position:0% +gonna get into that today but for a + + + align:start position:0% +gonna get into that today but for a +crystalline silicon it's it's heat is + + align:start position:0% +crystalline silicon it's it's heat is + + + align:start position:0% +crystalline silicon it's it's heat is +generally very bad for the performance + + align:start position:0% +generally very bad for the performance + + + align:start position:0% +generally very bad for the performance +and when you do testing so for example + + align:start position:0% +and when you do testing so for example + + + align:start position:0% +and when you do testing so for example +when NREL does tensing they'll rate all + + align:start position:0% +when NREL does tensing they'll rate all + + + align:start position:0% +when NREL does tensing they'll rate all +your cells at you know am 1.5 g some + + align:start position:0% +your cells at you know am 1.5 g some + + + align:start position:0% +your cells at you know am 1.5 g some +calibrated solar simulator that's you + + align:start position:0% +calibrated solar simulator that's you + + + align:start position:0% +calibrated solar simulator that's you +know illuminating your sample and + + align:start position:0% +know illuminating your sample and + + + align:start position:0% +know illuminating your sample and +they're kept at constant temperature so + + align:start position:0% +they're kept at constant temperature so + + + align:start position:0% +they're kept at constant temperature so +the temperatures always reported and + + align:start position:0% +the temperatures always reported and + + + align:start position:0% +the temperatures always reported and +it's generally kept at 25 C so the + + align:start position:0% +it's generally kept at 25 C so the + + + align:start position:0% +it's generally kept at 25 C so the +temperatures are very important + + align:start position:0% +temperatures are very important + + + align:start position:0% +temperatures are very important +characteristic but to answer your + + align:start position:0% +characteristic but to answer your + + + align:start position:0% +characteristic but to answer your +question if again we looked at an + + align:start position:0% +question if again we looked at an + + + align:start position:0% +question if again we looked at an +Arrhenius plot so this is 1 over KT so + + align:start position:0% +Arrhenius plot so this is 1 over KT so + + + align:start position:0% +Arrhenius plot so this is 1 over KT so +this is high temperatures over here low + + align:start position:0% +this is high temperatures over here low + + + align:start position:0% +this is high temperatures over here low +temperatures over here and this is + + align:start position:0% +temperatures over here and this is + + + align:start position:0% +temperatures over here and this is +carrier concentration at very very high + + align:start position:0% +carrier concentration at very very high + + + align:start position:0% +carrier concentration at very very high +temperatures the when when your thermal + + align:start position:0% +temperatures the when when your thermal + + + align:start position:0% +temperatures the when when your thermal +carrier so if you extend this out to + + align:start position:0% +carrier so if you extend this out to + + + align:start position:0% +carrier so if you extend this out to +higher temperature you can see that this + + align:start position:0% +higher temperature you can see that this + + + align:start position:0% +higher temperature you can see that this +will actually surpass the number of + + align:start position:0% +will actually surpass the number of + + + align:start position:0% +will actually surpass the number of +dopant atoms and you'll actually + + align:start position:0% +dopant atoms and you'll actually + + + align:start position:0% +dopant atoms and you'll actually +increase so this is high temperature + + align:start position:0% +increase so this is high temperature + + + align:start position:0% +increase so this is high temperature +over here + + align:start position:0% + + + + align:start position:0% + +your carrier concentration will actually + + align:start position:0% +your carrier concentration will actually + + + align:start position:0% +your carrier concentration will actually +increase at much much lower sorry much + + align:start position:0% +increase at much much lower sorry much + + + align:start position:0% +increase at much much lower sorry much +much higher temperatures and this is + + align:start position:0% +much higher temperatures and this is + + + align:start position:0% +much higher temperatures and this is +what's the extrinsic region so your + + align:start position:0% +what's the extrinsic region so your + + + align:start position:0% +what's the extrinsic region so your +donor concentration is pretty much only + + align:start position:0% +donor concentration is pretty much only + + + align:start position:0% +donor concentration is pretty much only +determined by your dopant density so + + align:start position:0% +determined by your dopant density so + + + align:start position:0% +determined by your dopant density so +this is MD and then at low enough + + align:start position:0% +this is MD and then at low enough + + + align:start position:0% +this is MD and then at low enough +temperature so this is very low + + align:start position:0% +temperature so this is very low + + + align:start position:0% +temperature so this is very low +temperatures you actually start freezing + + align:start position:0% +temperatures you actually start freezing + + + align:start position:0% +temperatures you actually start freezing +out your donor electrons into these + + align:start position:0% +out your donor electrons into these + + + align:start position:0% +out your donor electrons into these +donor states so that actually sums it up + + align:start position:0% +donor states so that actually sums it up + + + align:start position:0% +donor states so that actually sums it up +if you guys have other questions feel + + align:start position:0% +if you guys have other questions feel + + + align:start position:0% +if you guys have other questions feel +free to ask them but we actually can end + + align:start position:0% +free to ask them but we actually can end + + + align:start position:0% +free to ask them but we actually can end +a little bit early I do have your + + align:start position:0% +a little bit early I do have your + + + align:start position:0% +a little bit early I do have your +homework so if you want those come up + + align:start position:0% +homework so if you want those come up + + + align:start position:0% +homework so if you want those come up +here and I think Tonio posted the + + align:start position:0% +here and I think Tonio posted the + + + align:start position:0% +here and I think Tonio posted the +projects online so you can finish + + align:start position:0% +projects online so you can finish + + + align:start position:0% +projects online so you can finish +homework number three that's it + + align:start position:0% + + + + align:start position:0% + +you \ No newline at end of file diff --git a/wyT7EFJlBak.txt b/wyT7EFJlBak.txt new file mode 100644 index 0000000000000000000000000000000000000000..b59cbd5e1159dedc8a4e6f66a8837f77c9792f12 --- /dev/null +++ b/wyT7EFJlBak.txt @@ -0,0 +1,2499 @@ +align:start position:0% + +the following content is provided under + + align:start position:0% +the following content is provided under + + + align:start position:0% +the following content is provided under +a Creative Commons license your support + + align:start position:0% +a Creative Commons license your support + + + align:start position:0% +a Creative Commons license your support +will help MIT OpenCourseWare continue to + + align:start position:0% +will help MIT OpenCourseWare continue to + + + align:start position:0% +will help MIT OpenCourseWare continue to +offer high quality educational resources + + align:start position:0% +offer high quality educational resources + + + align:start position:0% +offer high quality educational resources +for free + + align:start position:0% +for free + + + align:start position:0% +for free +to make a donation or view additional + + align:start position:0% +to make a donation or view additional + + + align:start position:0% +to make a donation or view additional +materials from hundreds of MIT courses + + align:start position:0% +materials from hundreds of MIT courses + + + align:start position:0% +materials from hundreds of MIT courses +visit MIT opencourseware at ocw.mit.edu + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu + + + align:start position:0% +visit MIT opencourseware at ocw.mit.edu +welcome to the metabolism portion of + + align:start position:0% +welcome to the metabolism portion of + + + align:start position:0% +welcome to the metabolism portion of +biological chemistry 507 my name is + + align:start position:0% +biological chemistry 507 my name is + + + align:start position:0% +biological chemistry 507 my name is +Johnny Sigmund and I teach this course + + align:start position:0% +Johnny Sigmund and I teach this course + + + align:start position:0% +Johnny Sigmund and I teach this course +with Joann stubby I'm primarily a + + align:start position:0% +with Joann stubby I'm primarily a + + + align:start position:0% +with Joann stubby I'm primarily a +chalkboard teacher as you'll notice from + + align:start position:0% +chalkboard teacher as you'll notice from + + + align:start position:0% +chalkboard teacher as you'll notice from +my notes in order to make things as + + align:start position:0% +my notes in order to make things as + + + align:start position:0% +my notes in order to make things as +simple as possible I use a lot of + + align:start position:0% +simple as possible I use a lot of + + + align:start position:0% +simple as possible I use a lot of +abbreviations in my abbreviations list + + align:start position:0% +abbreviations in my abbreviations list + + + align:start position:0% +abbreviations in my abbreviations list +will be appended elsewhere let's start + + align:start position:0% +will be appended elsewhere let's start + + + align:start position:0% +will be appended elsewhere let's start +by looking at a metabolic chart figure + + align:start position:0% +by looking at a metabolic chart figure + + + align:start position:0% +by looking at a metabolic chart figure +16 - 1 from the textbook obviously it + + align:start position:0% +16 - 1 from the textbook obviously it + + + align:start position:0% +16 - 1 from the textbook obviously it +looks very complex part of the challenge + + align:start position:0% +looks very complex part of the challenge + + + align:start position:0% +looks very complex part of the challenge +of both teaching and learning + + align:start position:0% +of both teaching and learning + + + align:start position:0% +of both teaching and learning +biochemistry is finding a way to look at + + align:start position:0% +biochemistry is finding a way to look at + + + align:start position:0% +biochemistry is finding a way to look at +this pigs breakfast of biochemical + + align:start position:0% +this pigs breakfast of biochemical + + + align:start position:0% +this pigs breakfast of biochemical +reactions and find its underlying + + align:start position:0% +reactions and find its underlying + + + align:start position:0% +reactions and find its underlying +structure for the purpose of this course + + align:start position:0% +structure for the purpose of this course + + + align:start position:0% +structure for the purpose of this course +the underlying structure we're going to + + align:start position:0% +the underlying structure we're going to + + + align:start position:0% +the underlying structure we're going to +look for is the biochemical pathways + + align:start position:0% +look for is the biochemical pathways + + + align:start position:0% +look for is the biochemical pathways +that let us function for example a + + align:start position:0% +that let us function for example a + + + align:start position:0% +that let us function for example a +pathway could involve making ATP or it + + align:start position:0% +pathway could involve making ATP or it + + + align:start position:0% +pathway could involve making ATP or it +could be putting an amino group onto an + + align:start position:0% +could be putting an amino group onto an + + + align:start position:0% +could be putting an amino group onto an +alpha keto acid in order to make an + + align:start position:0% +alpha keto acid in order to make an + + + align:start position:0% +alpha keto acid in order to make an +amino acid although a few people think + + align:start position:0% +amino acid although a few people think + + + align:start position:0% +amino acid although a few people think +of biochemistry is simple formatting the + + align:start position:0% +of biochemistry is simple formatting the + + + align:start position:0% +of biochemistry is simple formatting the +pigs breakfast into pathways that have + + align:start position:0% +pigs breakfast into pathways that have + + + align:start position:0% +pigs breakfast into pathways that have +functional meaning helps us simplify + + align:start position:0% +functional meaning helps us simplify + + + align:start position:0% +functional meaning helps us simplify +them and make them easier to remember + + align:start position:0% +them and make them easier to remember + + + align:start position:0% +them and make them easier to remember +the second simplifying point is that all + + align:start position:0% +the second simplifying point is that all + + + align:start position:0% +the second simplifying point is that all +biochemical pathways are reversible the + + align:start position:0% +biochemical pathways are reversible the + + + align:start position:0% +biochemical pathways are reversible the +gray vertical bar in the middle of this + + align:start position:0% +gray vertical bar in the middle of this + + + align:start position:0% +gray vertical bar in the middle of this +figure is the biochemical pathway of + + align:start position:0% +figure is the biochemical pathway of + + + align:start position:0% +figure is the biochemical pathway of +glycolysis going from glucose to + + align:start position:0% +glycolysis going from glucose to + + + align:start position:0% +glycolysis going from glucose to +pyruvate there are 10 steps some of + + align:start position:0% +pyruvate there are 10 steps some of + + + align:start position:0% +pyruvate there are 10 steps some of +these steps have a negative Delta G that + + align:start position:0% +these steps have a negative Delta G that + + + align:start position:0% +these steps have a negative Delta G that +is they are favorable in the direction + + align:start position:0% +is they are favorable in the direction + + + align:start position:0% +is they are favorable in the direction +drawn and some of them have a positive + + align:start position:0% +drawn and some of them have a positive + + + align:start position:0% +drawn and some of them have a positive +Delta G that is those steps are + + align:start position:0% +Delta G that is those steps are + + + align:start position:0% +Delta G that is those steps are +favorable in the opposite direction but + + align:start position:0% +favorable in the opposite direction but + + + align:start position:0% +favorable in the opposite direction but +overall when you sum them up all of the + + align:start position:0% +overall when you sum them up all of the + + + align:start position:0% +overall when you sum them up all of the +free energies of the glycolytic pathway + + align:start position:0% +free energies of the glycolytic pathway + + + align:start position:0% +free energies of the glycolytic pathway +you get a negative number which means + + align:start position:0% +you get a negative number which means + + + align:start position:0% +you get a negative number which means +that the pathway of glycolysis is + + align:start position:0% +that the pathway of glycolysis is + + + align:start position:0% +that the pathway of glycolysis is +overall thermodynamically irreversible + + align:start position:0% +overall thermodynamically irreversible + + + align:start position:0% +overall thermodynamically irreversible +and progresses from glucose to pyruvate + + align:start position:0% +and progresses from glucose to pyruvate + + + align:start position:0% +and progresses from glucose to pyruvate +it turns out that there's another + + align:start position:0% +it turns out that there's another + + + align:start position:0% +it turns out that there's another +pathway called gluconeogenesis that + + align:start position:0% +pathway called gluconeogenesis that + + + align:start position:0% +pathway called gluconeogenesis that +pathway it involves taking non + + align:start position:0% +pathway it involves taking non + + + align:start position:0% +pathway it involves taking non +carbohydrate precursors such as pyruvate + + align:start position:0% +carbohydrate precursors such as pyruvate + + + align:start position:0% +carbohydrate precursors such as pyruvate +that's just one example + + align:start position:0% +that's just one example + + + align:start position:0% +that's just one example +kill and converting that precursor to + + align:start position:0% +kill and converting that precursor to + + + align:start position:0% +kill and converting that precursor to +glucose in other words gluconeogenesis + + align:start position:0% +glucose in other words gluconeogenesis + + + align:start position:0% +glucose in other words gluconeogenesis +in effect is the reverse of glycolysis + + align:start position:0% +in effect is the reverse of glycolysis + + + align:start position:0% +in effect is the reverse of glycolysis +as I said the pathway going from glucose + + align:start position:0% +as I said the pathway going from glucose + + + align:start position:0% +as I said the pathway going from glucose +down to pyruvate is exergonic so what + + align:start position:0% +down to pyruvate is exergonic so what + + + align:start position:0% +down to pyruvate is exergonic so what +about the pathway from pyruvate up to + + align:start position:0% +about the pathway from pyruvate up to + + + align:start position:0% +about the pathway from pyruvate up to +glucose in order to make the pathway go + + align:start position:0% +glucose in order to make the pathway go + + + align:start position:0% +glucose in order to make the pathway go +from pyruvate to glucose what nature did + + align:start position:0% +from pyruvate to glucose what nature did + + + align:start position:0% +from pyruvate to glucose what nature did +was invent several biochemical steps + + align:start position:0% +was invent several biochemical steps + + + align:start position:0% +was invent several biochemical steps +that are highly exergonic that is what + + align:start position:0% +that are highly exergonic that is what + + + align:start position:0% +that are highly exergonic that is what +we'll see is they're going to require + + align:start position:0% +we'll see is they're going to require + + + align:start position:0% +we'll see is they're going to require +ATP or some other form of energy input + + align:start position:0% +ATP or some other form of energy input + + + align:start position:0% +ATP or some other form of energy input +in order to make the entire pathway of + + align:start position:0% +in order to make the entire pathway of + + + align:start position:0% +in order to make the entire pathway of +gluconeogenesis exergonic exergonic as + + align:start position:0% +gluconeogenesis exergonic exergonic as + + + align:start position:0% +gluconeogenesis exergonic exergonic as +is required of all pathways so we can + + align:start position:0% +is required of all pathways so we can + + + align:start position:0% +is required of all pathways so we can +indeed convert pyruvate to glucose but + + align:start position:0% +indeed convert pyruvate to glucose but + + + align:start position:0% +indeed convert pyruvate to glucose but +it will require energy input to make the + + align:start position:0% +it will require energy input to make the + + + align:start position:0% +it will require energy input to make the +pathway of gluconeogenesis have a net + + align:start position:0% +pathway of gluconeogenesis have a net + + + align:start position:0% +pathway of gluconeogenesis have a net +negative Delta G that is be favorable + + align:start position:0% +negative Delta G that is be favorable + + + align:start position:0% +negative Delta G that is be favorable +the third thing that actually makes + + align:start position:0% +the third thing that actually makes + + + align:start position:0% +the third thing that actually makes +biochemistry tractable is the fact that + + align:start position:0% +biochemistry tractable is the fact that + + + align:start position:0% +biochemistry tractable is the fact that +nature uses only a very limited + + align:start position:0% +nature uses only a very limited + + + align:start position:0% +nature uses only a very limited +repertoire of chemical reactions + + align:start position:0% +repertoire of chemical reactions + + + align:start position:0% +repertoire of chemical reactions +Joanne showed us that despite the + + align:start position:0% +Joanne showed us that despite the + + + align:start position:0% +Joanne showed us that despite the +complexity of this overall metabolic + + align:start position:0% +complexity of this overall metabolic + + + align:start position:0% +complexity of this overall metabolic +chart there are only about nine or ten + + align:start position:0% +chart there are only about nine or ten + + + align:start position:0% +chart there are only about nine or ten +discrete chemical reactions that nature + + align:start position:0% +discrete chemical reactions that nature + + + align:start position:0% +discrete chemical reactions that nature +uses so at any given step for example in + + align:start position:0% +uses so at any given step for example in + + + align:start position:0% +uses so at any given step for example in +glycolysis you really only have about + + align:start position:0% +glycolysis you really only have about + + + align:start position:0% +glycolysis you really only have about +nine or ten options and of that nine or + + align:start position:0% +nine or ten options and of that nine or + + + align:start position:0% +nine or ten options and of that nine or +ten only about one or two perhaps three + + align:start position:0% +ten only about one or two perhaps three + + + align:start position:0% +ten only about one or two perhaps three +would be chemically reasonable if you + + align:start position:0% +would be chemically reasonable if you + + + align:start position:0% +would be chemically reasonable if you +know your organic chemistry and these + + align:start position:0% +know your organic chemistry and these + + + align:start position:0% +know your organic chemistry and these +nine or ten reaction types you should be + + align:start position:0% +nine or ten reaction types you should be + + + align:start position:0% +nine or ten reaction types you should be +able to navigate the biochemical chart + + align:start position:0% +able to navigate the biochemical chart + + + align:start position:0% +able to navigate the biochemical chart +with comparative ease the fourth point I + + align:start position:0% +with comparative ease the fourth point I + + + align:start position:0% +with comparative ease the fourth point I +wanted to make is perhaps one of the + + align:start position:0% +wanted to make is perhaps one of the + + + align:start position:0% +wanted to make is perhaps one of the +most important is that all biochemical + + align:start position:0% +most important is that all biochemical + + + align:start position:0% +most important is that all biochemical +pathways are regulated chaos would + + align:start position:0% +pathways are regulated chaos would + + + align:start position:0% +pathways are regulated chaos would +result for example if you made glucose + + align:start position:0% +result for example if you made glucose + + + align:start position:0% +result for example if you made glucose +and at the same time took that molecule + + align:start position:0% +and at the same time took that molecule + + + align:start position:0% +and at the same time took that molecule +of glucose and degraded it that's an + + align:start position:0% +of glucose and degraded it that's an + + + align:start position:0% +of glucose and degraded it that's an +example of what we call a futile cycle + + align:start position:0% +example of what we call a futile cycle + + + align:start position:0% +example of what we call a futile cycle +sometimes util cycles can be beneficial + + align:start position:0% +sometimes util cycles can be beneficial + + + align:start position:0% +sometimes util cycles can be beneficial +to a cell for example that could be a + + align:start position:0% +to a cell for example that could be a + + + align:start position:0% +to a cell for example that could be a +way of generating heat but most of the + + align:start position:0% +way of generating heat but most of the + + + align:start position:0% +way of generating heat but most of the +time we want to avoid them because we + + align:start position:0% +time we want to avoid them because we + + + align:start position:0% +time we want to avoid them because we +usually want to avoid futile cycles + + align:start position:0% +usually want to avoid futile cycles + + + align:start position:0% +usually want to avoid futile cycles +nature uses pathway regulation to avoid + + align:start position:0% +nature uses pathway regulation to avoid + + + align:start position:0% +nature uses pathway regulation to avoid +them to provide directionality to + + align:start position:0% +them to provide directionality to + + + align:start position:0% +them to provide directionality to +pathways what nature does is work + + align:start position:0% +pathways what nature does is work + + + align:start position:0% +pathways what nature does is work +thermodynamically irreversible steps + + align:start position:0% +thermodynamically irreversible steps + + + align:start position:0% +thermodynamically irreversible steps +into the front end and back end of the + + align:start position:0% +into the front end and back end of the + + + align:start position:0% +into the front end and back end of the +pathway sometimes nature puts in an + + align:start position:0% +pathway sometimes nature puts in an + + + align:start position:0% +pathway sometimes nature puts in an +irreversible step in the middle of the + + align:start position:0% +irreversible step in the middle of the + + + align:start position:0% +irreversible step in the middle of the +pathway + + align:start position:0% +pathway + + + align:start position:0% +pathway +if that pathway has a branch point that + + align:start position:0% +if that pathway has a branch point that + + + align:start position:0% +if that pathway has a branch point that +happens with glycolysis cells will see + + align:start position:0% +happens with glycolysis cells will see + + + align:start position:0% +happens with glycolysis cells will see +sometimes regulation is affected by + + align:start position:0% +sometimes regulation is affected by + + + align:start position:0% +sometimes regulation is affected by +putting covalent functionalities such as + + align:start position:0% +putting covalent functionalities such as + + + align:start position:0% +putting covalent functionalities such as +a phosphate onto an amino acid on a + + align:start position:0% +a phosphate onto an amino acid on a + + + align:start position:0% +a phosphate onto an amino acid on a +protein that modification could increase + + align:start position:0% +protein that modification could increase + + + align:start position:0% +protein that modification could increase +or decrease the biochemical activity of + + align:start position:0% +or decrease the biochemical activity of + + + align:start position:0% +or decrease the biochemical activity of +that protein often a phosphorylated + + align:start position:0% +that protein often a phosphorylated + + + align:start position:0% +that protein often a phosphorylated +protein is highly active turning on a + + align:start position:0% +protein is highly active turning on a + + + align:start position:0% +protein is highly active turning on a +pathway and it is DS phosphorylated when + + align:start position:0% +pathway and it is DS phosphorylated when + + + align:start position:0% +pathway and it is DS phosphorylated when +the pathway needs to be turned off a + + align:start position:0% +the pathway needs to be turned off a + + + align:start position:0% +the pathway needs to be turned off a +second way to regulate a step in the + + align:start position:0% +second way to regulate a step in the + + + align:start position:0% +second way to regulate a step in the +pathway is by allosteric regulation of + + align:start position:0% +pathway is by allosteric regulation of + + + align:start position:0% +pathway is by allosteric regulation of +the enzymes of the pathway in that case + + align:start position:0% +the enzymes of the pathway in that case + + + align:start position:0% +the enzymes of the pathway in that case +a small molecule will interact with the + + align:start position:0% +a small molecule will interact with the + + + align:start position:0% +a small molecule will interact with the +enzyme in order to increase or decrease + + align:start position:0% +enzyme in order to increase or decrease + + + align:start position:0% +enzyme in order to increase or decrease +its activity Joanne taught us about + + align:start position:0% +its activity Joanne taught us about + + + align:start position:0% +its activity Joanne taught us about +Alice Terry when she taught us how + + align:start position:0% +Alice Terry when she taught us how + + + align:start position:0% +Alice Terry when she taught us how +hemoglobin is regulated to reiterate + + align:start position:0% +hemoglobin is regulated to reiterate + + + align:start position:0% +hemoglobin is regulated to reiterate +nature uses these regulatable enzymes at + + align:start position:0% +nature uses these regulatable enzymes at + + + align:start position:0% +nature uses these regulatable enzymes at +key places in overall metabolic pathways + + align:start position:0% +key places in overall metabolic pathways + + + align:start position:0% +key places in overall metabolic pathways +to enable us to be able to achieve the + + align:start position:0% +to enable us to be able to achieve the + + + align:start position:0% +to enable us to be able to achieve the +function of the pathway without wasting + + align:start position:0% +function of the pathway without wasting + + + align:start position:0% +function of the pathway without wasting +energy or resources the last + + align:start position:0% +energy or resources the last + + + align:start position:0% +energy or resources the last +introductory point I want to make is + + align:start position:0% +introductory point I want to make is + + + align:start position:0% +introductory point I want to make is +that all biochemical pathways tend to be + + align:start position:0% +that all biochemical pathways tend to be + + + align:start position:0% +that all biochemical pathways tend to be +compartmentalized at least in mammalian + + align:start position:0% +compartmentalized at least in mammalian + + + align:start position:0% +compartmentalized at least in mammalian +cells although it's increasingly + + align:start position:0% +cells although it's increasingly + + + align:start position:0% +cells although it's increasingly +becoming obvious that even in bacteria + + align:start position:0% +becoming obvious that even in bacteria + + + align:start position:0% +becoming obvious that even in bacteria +there is some form of + + align:start position:0% +there is some form of + + + align:start position:0% +there is some form of +compartmentalization that is clustering + + align:start position:0% +compartmentalization that is clustering + + + align:start position:0% +compartmentalization that is clustering +of enzymes for a particular pathway in a + + align:start position:0% +of enzymes for a particular pathway in a + + + align:start position:0% +of enzymes for a particular pathway in a +particular area of the cell for example + + align:start position:0% +particular area of the cell for example + + + align:start position:0% +particular area of the cell for example +in a mammalian cell the mitochondrion is + + align:start position:0% +in a mammalian cell the mitochondrion is + + + align:start position:0% +in a mammalian cell the mitochondrion is +the site of fatty acid beta oxidation or + + align:start position:0% +the site of fatty acid beta oxidation or + + + align:start position:0% +the site of fatty acid beta oxidation or +breakdown the tricarboxylic acid cycle + + align:start position:0% +breakdown the tricarboxylic acid cycle + + + align:start position:0% +breakdown the tricarboxylic acid cycle +and enzymes of the pyruvate + + align:start position:0% +and enzymes of the pyruvate + + + align:start position:0% +and enzymes of the pyruvate +dehydrogenase complex are also + + align:start position:0% +dehydrogenase complex are also + + + align:start position:0% +dehydrogenase complex are also +mitochondrial the cytoplasm is the site + + align:start position:0% +mitochondrial the cytoplasm is the site + + + align:start position:0% +mitochondrial the cytoplasm is the site +where we do fatty acid biosynthesis most + + align:start position:0% +where we do fatty acid biosynthesis most + + + align:start position:0% +where we do fatty acid biosynthesis most +of gluconeogenesis glycolysis and the + + align:start position:0% +of gluconeogenesis glycolysis and the + + + align:start position:0% +of gluconeogenesis glycolysis and the +pentose phosphate pathway + + align:start position:0% +pentose phosphate pathway + + + align:start position:0% +pentose phosphate pathway +compartmentalization helps keep the + + align:start position:0% +compartmentalization helps keep the + + + align:start position:0% +compartmentalization helps keep the +metabolic chart tidy and organized with + + align:start position:0% +metabolic chart tidy and organized with + + + align:start position:0% +metabolic chart tidy and organized with +that in the way of an introduction let's + + align:start position:0% +that in the way of an introduction let's + + + align:start position:0% +that in the way of an introduction let's +turn to my lecture notes which i present + + align:start position:0% +turn to my lecture notes which i present + + + align:start position:0% +turn to my lecture notes which i present +in the format of storyboards in the + + align:start position:0% +in the format of storyboards in the + + + align:start position:0% +in the format of storyboards in the +first storyboard panel a I give the + + align:start position:0% +first storyboard panel a I give the + + + align:start position:0% +first storyboard panel a I give the +definition of metabolism as the linked + + align:start position:0% +definition of metabolism as the linked + + + align:start position:0% +definition of metabolism as the linked +set of biochemical reactions by which we + + align:start position:0% +set of biochemical reactions by which we + + + align:start position:0% +set of biochemical reactions by which we +obtain and use free energy that is Delta + + align:start position:0% +obtain and use free energy that is Delta + + + align:start position:0% +obtain and use free energy that is Delta +G for life we use that free energy for a + + align:start position:0% +G for life we use that free energy for a + + + align:start position:0% +G for life we use that free energy for a +lot of things but the use is really + + align:start position:0% +lot of things but the use is really + + + align:start position:0% +lot of things but the use is really +divided into three areas the first is to + + align:start position:0% +divided into three areas the first is to + + + align:start position:0% +divided into three areas the first is to +do mechanical work the second is to + + align:start position:0% +do mechanical work the second is to + + + align:start position:0% +do mechanical work the second is to +generate concentration gradients and the + + align:start position:0% +generate concentration gradients and the + + + align:start position:0% +generate concentration gradients and the +third + + align:start position:0% +third + + + align:start position:0% +third +is for biosynthesis in a few minutes I'm + + align:start position:0% +is for biosynthesis in a few minutes I'm + + + align:start position:0% +is for biosynthesis in a few minutes I'm +going to be giving you an example of all + + align:start position:0% +going to be giving you an example of all + + + align:start position:0% +going to be giving you an example of all +three panel B biochemists divide + + align:start position:0% +three panel B biochemists divide + + + align:start position:0% +three panel B biochemists divide +metabolism to two subcategories + + align:start position:0% +metabolism to two subcategories + + + align:start position:0% +metabolism to two subcategories +catabolism and anabolism briefly + + align:start position:0% +catabolism and anabolism briefly + + + align:start position:0% +catabolism and anabolism briefly +catabolism consists of the energy + + align:start position:0% +catabolism consists of the energy + + + align:start position:0% +catabolism consists of the energy +yielding pathways an analysis basically + + align:start position:0% +yielding pathways an analysis basically + + + align:start position:0% +yielding pathways an analysis basically +biosynthesis we use the free energy that + + align:start position:0% +biosynthesis we use the free energy that + + + align:start position:0% +biosynthesis we use the free energy that +we generate through catabolism in order + + align:start position:0% +we generate through catabolism in order + + + align:start position:0% +we generate through catabolism in order +to assemble complex molecules by way of + + align:start position:0% +to assemble complex molecules by way of + + + align:start position:0% +to assemble complex molecules by way of +an Abba lism let's look at panel C we're + + align:start position:0% +an Abba lism let's look at panel C we're + + + align:start position:0% +an Abba lism let's look at panel C we're +going to start 5:07 with the discussion + + align:start position:0% +going to start 5:07 with the discussion + + + align:start position:0% +going to start 5:07 with the discussion +of catabolism that is the energy + + align:start position:0% +of catabolism that is the energy + + + align:start position:0% +of catabolism that is the energy +yielding pathways by way of definitions + + align:start position:0% +yielding pathways by way of definitions + + + align:start position:0% +yielding pathways by way of definitions +a reduced molecule is one that is + + align:start position:0% +a reduced molecule is one that is + + + align:start position:0% +a reduced molecule is one that is +abundantly supplied with electrons + + align:start position:0% +abundantly supplied with electrons + + + align:start position:0% +abundantly supplied with electrons +examples are carbohydrates fats and + + align:start position:0% +examples are carbohydrates fats and + + + align:start position:0% +examples are carbohydrates fats and +proteins these are typically our foods + + align:start position:0% +proteins these are typically our foods + + + align:start position:0% +proteins these are typically our foods +the process of catabolism involves + + align:start position:0% +the process of catabolism involves + + + align:start position:0% +the process of catabolism involves +finding a way to liberate the electrons + + align:start position:0% +finding a way to liberate the electrons + + + align:start position:0% +finding a way to liberate the electrons +from those reduced substances and + + align:start position:0% +from those reduced substances and + + + align:start position:0% +from those reduced substances and +transfer those electrons to mobile + + align:start position:0% +transfer those electrons to mobile + + + align:start position:0% +transfer those electrons to mobile +electron carriers such as nad plus to + + align:start position:0% +electron carriers such as nad plus to + + + align:start position:0% +electron carriers such as nad plus to +form NADH or nadp+ to form NADPH the + + align:start position:0% +form NADH or nadp+ to form NADPH the + + + align:start position:0% +form NADH or nadp+ to form NADPH the +process by which electrons are removed + + align:start position:0% +process by which electrons are removed + + + align:start position:0% +process by which electrons are removed +from a molecule is called oxidation and + + align:start position:0% +from a molecule is called oxidation and + + + align:start position:0% +from a molecule is called oxidation and +the oxidation products are for example + + align:start position:0% +the oxidation products are for example + + + align:start position:0% +the oxidation products are for example +carbon dioxide that we breathe out or in + + align:start position:0% +carbon dioxide that we breathe out or in + + + align:start position:0% +carbon dioxide that we breathe out or in +some organisms lactate or other simple + + align:start position:0% +some organisms lactate or other simple + + + align:start position:0% +some organisms lactate or other simple +molecules that are excreted simple that + + align:start position:0% +molecules that are excreted simple that + + + align:start position:0% +molecules that are excreted simple that +is compared to the complex reduced + + align:start position:0% +is compared to the complex reduced + + + align:start position:0% +is compared to the complex reduced +molecules that we consume as food nadh + + align:start position:0% +molecules that we consume as food nadh + + + align:start position:0% +molecules that we consume as food nadh +and fadh2 molecules that Joanne taught + + align:start position:0% +and fadh2 molecules that Joanne taught + + + align:start position:0% +and fadh2 molecules that Joanne taught +us are what I'll refer to as mobile + + align:start position:0% +us are what I'll refer to as mobile + + + align:start position:0% +us are what I'll refer to as mobile +electron carriers they can usually move + + align:start position:0% +electron carriers they can usually move + + + align:start position:0% +electron carriers they can usually move +around inside the cell although + + align:start position:0% +around inside the cell although + + + align:start position:0% +around inside the cell although +sometimes they're embedded within + + align:start position:0% +sometimes they're embedded within + + + align:start position:0% +sometimes they're embedded within +enzymes that is usually the case with + + align:start position:0% +enzymes that is usually the case with + + + align:start position:0% +enzymes that is usually the case with +fadh2 we consume an enormous lee large + + align:start position:0% +fadh2 we consume an enormous lee large + + + align:start position:0% +fadh2 we consume an enormous lee large +number of reduced substances due to the + + align:start position:0% +number of reduced substances due to the + + + align:start position:0% +number of reduced substances due to the +complexities of our diets and catabolism + + align:start position:0% +complexities of our diets and catabolism + + + align:start position:0% +complexities of our diets and catabolism +revolves taking the electrons out of + + align:start position:0% +revolves taking the electrons out of + + + align:start position:0% +revolves taking the electrons out of +this enormous leave ass array of + + align:start position:0% +this enormous leave ass array of + + + align:start position:0% +this enormous leave ass array of +substrates and transferring those + + align:start position:0% +substrates and transferring those + + + align:start position:0% +substrates and transferring those +electrons to a small number of reduced + + align:start position:0% +electrons to a small number of reduced + + + align:start position:0% +electrons to a small number of reduced +electron carriers for example an ad or + + align:start position:0% +electron carriers for example an ad or + + + align:start position:0% +electron carriers for example an ad or +Flavin's in the process of respiration + + align:start position:0% +Flavin's in the process of respiration + + + align:start position:0% +Flavin's in the process of respiration +which we'll come to later the electrons + + align:start position:0% +which we'll come to later the electrons + + + align:start position:0% +which we'll come to later the electrons +are further transferred from the reduced + + align:start position:0% +are further transferred from the reduced + + + align:start position:0% +are further transferred from the reduced +electron carriers all the way to + + align:start position:0% +electron carriers all the way to + + + align:start position:0% +electron carriers all the way to +molecular oxygen the reduction of + + align:start position:0% +molecular oxygen the reduction of + + + align:start position:0% +molecular oxygen the reduction of +molecular oxygen is a highly exothermic + + align:start position:0% +molecular oxygen is a highly exothermic + + + align:start position:0% +molecular oxygen is a highly exothermic +reaction we're going to be able to use + + align:start position:0% +reaction we're going to be able to use + + + align:start position:0% +reaction we're going to be able to use +the energy that's generated by + + align:start position:0% +the energy that's generated by + + + align:start position:0% +the energy that's generated by +oxygen reduction in order to make ATP + + align:start position:0% +oxygen reduction in order to make ATP + + + align:start position:0% +oxygen reduction in order to make ATP +and to do some other important + + align:start position:0% +and to do some other important + + + align:start position:0% +and to do some other important +biochemical activities now I'm going to + + align:start position:0% +biochemical activities now I'm going to + + + align:start position:0% +biochemical activities now I'm going to +introduce a physiological scenario and + + align:start position:0% +introduce a physiological scenario and + + + align:start position:0% +introduce a physiological scenario and +use it in order to introduce the pathway + + align:start position:0% +use it in order to introduce the pathway + + + align:start position:0% +use it in order to introduce the pathway +of glycolysis in class at this point I + + align:start position:0% +of glycolysis in class at this point I + + + align:start position:0% +of glycolysis in class at this point I +usually ask a student to stand up and + + align:start position:0% +usually ask a student to stand up and + + + align:start position:0% +usually ask a student to stand up and +sit down as you can imagine being called + + align:start position:0% +sit down as you can imagine being called + + + align:start position:0% +sit down as you can imagine being called +out in class creates more than a little + + align:start position:0% +out in class creates more than a little + + + align:start position:0% +out in class creates more than a little +bit of anxiety in the student let's look + + align:start position:0% +bit of anxiety in the student let's look + + + align:start position:0% +bit of anxiety in the student let's look +at panel D the signal to stand up and + + align:start position:0% +at panel D the signal to stand up and + + + align:start position:0% +at panel D the signal to stand up and +sit down is processed by the brain and + + align:start position:0% +sit down is processed by the brain and + + + align:start position:0% +sit down is processed by the brain and +an electrical signal then goes by the + + align:start position:0% +an electrical signal then goes by the + + + align:start position:0% +an electrical signal then goes by the +nerves to the muscles enabling the + + align:start position:0% +nerves to the muscles enabling the + + + align:start position:0% +nerves to the muscles enabling the +student to stand up the anxiety of being + + align:start position:0% +student to stand up the anxiety of being + + + align:start position:0% +student to stand up the anxiety of being +called on by the teacher in class + + align:start position:0% +called on by the teacher in class + + + align:start position:0% +called on by the teacher in class +results in a nervous excitation of the + + align:start position:0% +results in a nervous excitation of the + + + align:start position:0% +results in a nervous excitation of the +adrenal gland specifically in the + + align:start position:0% +adrenal gland specifically in the + + + align:start position:0% +adrenal gland specifically in the +andrina medulla which releases + + align:start position:0% +andrina medulla which releases + + + align:start position:0% +andrina medulla which releases +epinephrine epinephrine is also known as + + align:start position:0% +epinephrine epinephrine is also known as + + + align:start position:0% +epinephrine epinephrine is also known as +adrenaline it goes to the muscles as + + align:start position:0% +adrenaline it goes to the muscles as + + + align:start position:0% +adrenaline it goes to the muscles as +well as other organs of the body as + + align:start position:0% +well as other organs of the body as + + + align:start position:0% +well as other organs of the body as +we'll see later in 507 and the + + align:start position:0% +we'll see later in 507 and the + + + align:start position:0% +we'll see later in 507 and the +epinephrine will interact at cell + + align:start position:0% +epinephrine will interact at cell + + + align:start position:0% +epinephrine will interact at cell +membranes by way of transmembrane + + align:start position:0% +membranes by way of transmembrane + + + align:start position:0% +membranes by way of transmembrane +receptors in order to turn on pathways + + align:start position:0% +receptors in order to turn on pathways + + + align:start position:0% +receptors in order to turn on pathways +of catabolism in order to generate the + + align:start position:0% +of catabolism in order to generate the + + + align:start position:0% +of catabolism in order to generate the +ATP that's needed to help the student + + align:start position:0% +ATP that's needed to help the student + + + align:start position:0% +ATP that's needed to help the student +deal with this stressful situation this + + align:start position:0% +deal with this stressful situation this + + + align:start position:0% +deal with this stressful situation this +is sometimes called the fight-or-flight + + align:start position:0% +is sometimes called the fight-or-flight + + + align:start position:0% +is sometimes called the fight-or-flight +response at this point in the class if I + + align:start position:0% +response at this point in the class if I + + + align:start position:0% +response at this point in the class if I +really wanted to make my point and have + + align:start position:0% +really wanted to make my point and have + + + align:start position:0% +really wanted to make my point and have +it transferred to every student + + align:start position:0% +it transferred to every student + + + align:start position:0% +it transferred to every student +I'd announce a pop quiz the announcement + + align:start position:0% +I'd announce a pop quiz the announcement + + + align:start position:0% +I'd announce a pop quiz the announcement +of a pop quiz would cause kind of this + + align:start position:0% +of a pop quiz would cause kind of this + + + align:start position:0% +of a pop quiz would cause kind of this +cold feeling throughout your gut that's + + align:start position:0% +cold feeling throughout your gut that's + + + align:start position:0% +cold feeling throughout your gut that's +actually the feeling of adrenaline + + align:start position:0% +actually the feeling of adrenaline + + + align:start position:0% +actually the feeling of adrenaline +preparing your body to deal with the + + align:start position:0% +preparing your body to deal with the + + + align:start position:0% +preparing your body to deal with the +stress situation in that case of the + + align:start position:0% +stress situation in that case of the + + + align:start position:0% +stress situation in that case of the +quiz let's look at panel II as a + + align:start position:0% +quiz let's look at panel II as a + + + align:start position:0% +quiz let's look at panel II as a +scenario progresses let me introduce a + + align:start position:0% +scenario progresses let me introduce a + + + align:start position:0% +scenario progresses let me introduce a +few biochemical players glycogen + + align:start position:0% +few biochemical players glycogen + + + align:start position:0% +few biochemical players glycogen +phosphorylase glucose glucose + + align:start position:0% +phosphorylase glucose glucose + + + align:start position:0% +phosphorylase glucose glucose +6-phosphate and glucose 1-phosphate + + align:start position:0% +6-phosphate and glucose 1-phosphate + + + align:start position:0% +6-phosphate and glucose 1-phosphate +in panel F we see a muscle cell the + + align:start position:0% +in panel F we see a muscle cell the + + + align:start position:0% +in panel F we see a muscle cell the +epinephrine in the blood is only going + + align:start position:0% +epinephrine in the blood is only going + + + align:start position:0% +epinephrine in the blood is only going +to reach a concentration of about 10 to + + align:start position:0% +to reach a concentration of about 10 to + + + align:start position:0% +to reach a concentration of about 10 to +the minus 10 molar that's a very very + + align:start position:0% +the minus 10 molar that's a very very + + + align:start position:0% +the minus 10 molar that's a very very +low concentration the epinephrine is + + align:start position:0% +low concentration the epinephrine is + + + align:start position:0% +low concentration the epinephrine is +going to interact at the beta and alpha + + align:start position:0% +going to interact at the beta and alpha + + + align:start position:0% +going to interact at the beta and alpha +adrenergic receptors in the muscle cell + + align:start position:0% +adrenergic receptors in the muscle cell + + + align:start position:0% +adrenergic receptors in the muscle cell +membrane this interaction results in the + + align:start position:0% +membrane this interaction results in the + + + align:start position:0% +membrane this interaction results in the +activation of a kinase that is a + + align:start position:0% +activation of a kinase that is a + + + align:start position:0% +activation of a kinase that is a +molecule that transfers a phosphate + + align:start position:0% +molecule that transfers a phosphate + + + align:start position:0% +molecule that transfers a phosphate +group and that kinase which is called SP + + align:start position:0% +group and that kinase which is called SP + + + align:start position:0% +group and that kinase which is called SP +k4 + + align:start position:0% +k4 + + + align:start position:0% +k4 +days phosphorylase kinase phosphorylates + + align:start position:0% +days phosphorylase kinase phosphorylates + + + align:start position:0% +days phosphorylase kinase phosphorylates +serine 14 on glycogen phosphorylase + + align:start position:0% +serine 14 on glycogen phosphorylase + + + align:start position:0% +serine 14 on glycogen phosphorylase +phosphorylation activates glycogen + + align:start position:0% +phosphorylation activates glycogen + + + align:start position:0% +phosphorylation activates glycogen +phosphorylase which will then begin to + + align:start position:0% +phosphorylase which will then begin to + + + align:start position:0% +phosphorylase which will then begin to +degrade glycogen the polymeric storage + + align:start position:0% +degrade glycogen the polymeric storage + + + align:start position:0% +degrade glycogen the polymeric storage +form of glucose in us that is mammals to + + align:start position:0% +form of glucose in us that is mammals to + + + align:start position:0% +form of glucose in us that is mammals to +produce initially glucose 1-phosphate + + align:start position:0% +produce initially glucose 1-phosphate + + + align:start position:0% +produce initially glucose 1-phosphate +glucose 1-phosphate will then go through + + align:start position:0% +glucose 1-phosphate will then go through + + + align:start position:0% +glucose 1-phosphate will then go through +a number of transformations and + + align:start position:0% +a number of transformations and + + + align:start position:0% +a number of transformations and +eventually be converted into other forms + + align:start position:0% +eventually be converted into other forms + + + align:start position:0% +eventually be converted into other forms +of glucose and then other molecules that + + align:start position:0% +of glucose and then other molecules that + + + align:start position:0% +of glucose and then other molecules that +will generate energy in nutshell this + + align:start position:0% +will generate energy in nutshell this + + + align:start position:0% +will generate energy in nutshell this +stand up sit down scenario results in + + align:start position:0% +stand up sit down scenario results in + + + align:start position:0% +stand up sit down scenario results in +the generation of energy in a matter of + + align:start position:0% +the generation of energy in a matter of + + + align:start position:0% +the generation of energy in a matter of +seconds which is one of the things that + + align:start position:0% +seconds which is one of the things that + + + align:start position:0% +seconds which is one of the things that +we use metabolism for another thing i + + align:start position:0% +we use metabolism for another thing i + + + align:start position:0% +we use metabolism for another thing i +said earlier was that you use metabolic + + align:start position:0% +said earlier was that you use metabolic + + + align:start position:0% +said earlier was that you use metabolic +energy to generate concentration + + align:start position:0% +energy to generate concentration + + + align:start position:0% +energy to generate concentration +gradients and it turns out that + + align:start position:0% +gradients and it turns out that + + + align:start position:0% +gradients and it turns out that +generation of concentration gradients is + + align:start position:0% +generation of concentration gradients is + + + align:start position:0% +generation of concentration gradients is +absolutely critical for muscle activity + + align:start position:0% +absolutely critical for muscle activity + + + align:start position:0% +absolutely critical for muscle activity +the sarcoplasmic reticulum in our muscle + + align:start position:0% +the sarcoplasmic reticulum in our muscle + + + align:start position:0% +the sarcoplasmic reticulum in our muscle +cells must accumulate calcium and + + align:start position:0% +cells must accumulate calcium and + + + align:start position:0% +cells must accumulate calcium and +release it at precisely defined moments + + align:start position:0% +release it at precisely defined moments + + + align:start position:0% +release it at precisely defined moments +in order to enable the muscle to be able + + align:start position:0% +in order to enable the muscle to be able + + + align:start position:0% +in order to enable the muscle to be able +to work that concentration gradient of + + align:start position:0% +to work that concentration gradient of + + + align:start position:0% +to work that concentration gradient of +calcium has to be created and it's + + align:start position:0% +calcium has to be created and it's + + + align:start position:0% +calcium has to be created and it's +created with the energy that we get from + + align:start position:0% +created with the energy that we get from + + + align:start position:0% +created with the energy that we get from +metabolism again we'll see how calcium + + align:start position:0% +metabolism again we'll see how calcium + + + align:start position:0% +metabolism again we'll see how calcium +gradients help boot up energy generation + + align:start position:0% +gradients help boot up energy generation + + + align:start position:0% +gradients help boot up energy generation +in the last lecture which deals with + + align:start position:0% +in the last lecture which deals with + + + align:start position:0% +in the last lecture which deals with +pathway regulation \ No newline at end of file diff --git a/xCCeV-glFdM.txt b/xCCeV-glFdM.txt new file mode 100644 index 0000000000000000000000000000000000000000..27a00a5997e13aa828bde2d37551c3af60547d2b --- /dev/null +++ b/xCCeV-glFdM.txt @@ -0,0 +1,2667 @@ +align:start position:0% + +Okay. Um, it's time to move on to second + + align:start position:0% +Okay. Um, it's time to move on to second + + + align:start position:0% +Okay. Um, it's time to move on to second +order equations. First order equations + + align:start position:0% +order equations. First order equations + + + align:start position:0% +order equations. First order equations +we've done pretty carefully. Second + + align:start position:0% +we've done pretty carefully. Second + + + align:start position:0% +we've done pretty carefully. Second +order equations are a step harder and + + align:start position:0% +order equations are a step harder and + + + align:start position:0% +order equations are a step harder and +but they come up in nature. They come in + + align:start position:0% +but they come up in nature. They come in + + + align:start position:0% +but they come up in nature. They come in +every application because they include a + + align:start position:0% +every application because they include a + + + align:start position:0% +every application because they include a +an acceleration a second derivative. + + align:start position:0% +an acceleration a second derivative. + + + align:start position:0% +an acceleration a second derivative. +Okay. So this would be a second order + + align:start position:0% +Okay. So this would be a second order + + + align:start position:0% +Okay. So this would be a second order +equation because of that second + + align:start position:0% +equation because of that second + + + align:start position:0% +equation because of that second +derivative. I'm often going to have + + align:start position:0% +derivative. I'm often going to have + + + align:start position:0% +derivative. I'm often going to have +constant A, B, and C. We have enough + + align:start position:0% +constant A, B, and C. We have enough + + + align:start position:0% +constant A, B, and C. We have enough +difficulties to without allowing those + + align:start position:0% +difficulties to without allowing those + + + align:start position:0% +difficulties to without allowing those +to change. So A, B, C constants. + + align:start position:0% +to change. So A, B, C constants. + + + align:start position:0% +to change. So A, B, C constants. +Uh, and I doing the null solution to + + align:start position:0% +Uh, and I doing the null solution to + + + align:start position:0% +Uh, and I doing the null solution to +start with. + + align:start position:0% +start with. + + + align:start position:0% +start with. +Later there'll be a forcing term on the + + align:start position:0% +Later there'll be a forcing term on the + + + align:start position:0% +Later there'll be a forcing term on the +right hand side but today for this video + + align:start position:0% +right hand side but today for this video + + + align:start position:0% +right hand side but today for this video +null solutions and the point is now + + align:start position:0% +null solutions and the point is now + + + align:start position:0% +null solutions and the point is now +what's new is that there are two null + + align:start position:0% +what's new is that there are two null + + + align:start position:0% +what's new is that there are two null +solutions. So y null will be a + + align:start position:0% +solutions. So y null will be a + + + align:start position:0% +solutions. So y null will be a +combination of e and they're both + + align:start position:0% +combination of e and they're both + + + align:start position:0% +combination of e and they're both +exponentials. The having constant + + align:start position:0% +exponentials. The having constant + + + align:start position:0% +exponentials. The having constant +coefficients there means exponentials in + + align:start position:0% +coefficients there means exponentials in + + + align:start position:0% +coefficients there means exponentials in +the solution. So e to the some exponent + + align:start position:0% +the solution. So e to the some exponent + + + align:start position:0% +the solution. So e to the some exponent +and another one to a + + align:start position:0% +and another one to a + + + align:start position:0% +and another one to a +hopefully different exponent. + + align:start position:0% +hopefully different exponent. + + + align:start position:0% +hopefully different exponent. +Sometimes if s1 equals s2 that'll be a + + align:start position:0% +Sometimes if s1 equals s2 that'll be a + + + align:start position:0% +Sometimes if s1 equals s2 that'll be a +special case and we'll have a slight + + align:start position:0% +special case and we'll have a slight + + + align:start position:0% +special case and we'll have a slight +change but this is typical. So we have + + align:start position:0% +change but this is typical. So we have + + + align:start position:0% +change but this is typical. So we have +two constants c1 and c2 in the null + + align:start position:0% +two constants c1 and c2 in the null + + + align:start position:0% +two constants c1 and c2 in the null +solutions and we need two initial + + align:start position:0% +solutions and we need two initial + + + align:start position:0% +solutions and we need two initial +conditions to determine those constants. + + align:start position:0% +conditions to determine those constants. + + + align:start position:0% +conditions to determine those constants. +So previously for a first order equation + + align:start position:0% +So previously for a first order equation + + + align:start position:0% +So previously for a first order equation +we were given y of zero. + + align:start position:0% +we were given y of zero. + + + align:start position:0% +we were given y of zero. +Now + + align:start position:0% +Now + + + align:start position:0% +Now +when we have acceleration + + align:start position:0% +when we have acceleration + + + align:start position:0% +when we have acceleration +we give the initial velocity y prime of + + align:start position:0% +we give the initial velocity y prime of + + + align:start position:0% +we give the initial velocity y prime of +zero. + + align:start position:0% + + + + align:start position:0% + +Y prime I use may I use prime + + align:start position:0% +Y prime I use may I use prime + + + align:start position:0% +Y prime I use may I use prime +as a shorthand for derivative? + + align:start position:0% +as a shorthand for derivative? + + + align:start position:0% +as a shorthand for derivative? +y prime of zero is dydt + + align:start position:0% +y prime of zero is dydt + + + align:start position:0% +y prime of zero is dydt +at zero. So two conditions will at the + + align:start position:0% +at zero. So two conditions will at the + + + align:start position:0% +at zero. So two conditions will at the +right time determine those two + + align:start position:0% +right time determine those two + + + align:start position:0% +right time determine those two +constants. And just to say again so + + align:start position:0% +constants. And just to say again so + + + align:start position:0% +constants. And just to say again so +second derivative will be y doublep + + align:start position:0% +second derivative will be y doublep + + + align:start position:0% +second derivative will be y doublep +prime + + align:start position:0% +prime + + + align:start position:0% +prime +and that represents in physics it + + align:start position:0% +and that represents in physics it + + + align:start position:0% +and that represents in physics it +represents acceleration + + align:start position:0% +represents acceleration + + + align:start position:0% +represents acceleration +change in velocity. Change in y prime is + + align:start position:0% +change in velocity. Change in y prime is + + + align:start position:0% +change in velocity. Change in y prime is +yblep prime. And in a graph of a + + align:start position:0% +yblep prime. And in a graph of a + + + align:start position:0% +yblep prime. And in a graph of a +function, yblep prime shows up in + + align:start position:0% +function, yblep prime shows up in + + + align:start position:0% +function, yblep prime shows up in +bending of the graph. Bending of the + + align:start position:0% +bending of the graph. Bending of the + + + align:start position:0% +bending of the graph. Bending of the +graph because bending is a change in + + align:start position:0% +graph because bending is a change in + + + align:start position:0% +graph because bending is a change in +slope. Bending is a change + + align:start position:0% +slope. Bending is a change + + + align:start position:0% +slope. Bending is a change +in the slope. + + align:start position:0% +in the slope. + + + align:start position:0% +in the slope. +And the slope is y prime the first + + align:start position:0% +And the slope is y prime the first + + + align:start position:0% +And the slope is y prime the first +derivative. So to measure changes in y + + align:start position:0% +derivative. So to measure changes in y + + + align:start position:0% +derivative. So to measure changes in y +prime which will bend the graph the the + + align:start position:0% +prime which will bend the graph the the + + + align:start position:0% +prime which will bend the graph the the +my chalk would be a tangent line. As + + align:start position:0% +my chalk would be a tangent line. As + + + align:start position:0% +my chalk would be a tangent line. As +that changes that gives us a yblep prime + + align:start position:0% +that changes that gives us a yblep prime + + + align:start position:0% +that changes that gives us a yblep prime +a second derivative. Okay. So I'm ready + + align:start position:0% +a second derivative. Okay. So I'm ready + + + align:start position:0% +a second derivative. Okay. So I'm ready +for some examples. + + align:start position:0% +for some examples. + + + align:start position:0% +for some examples. +And the first example, the most basic + + align:start position:0% +And the first example, the most basic + + + align:start position:0% +And the first example, the most basic +equation of motion in + + align:start position:0% +equation of motion in + + + align:start position:0% +equation of motion in +uh physics and engineering, I would say + + align:start position:0% +uh physics and engineering, I would say + + + align:start position:0% +uh physics and engineering, I would say +it's called harmonic motion and B is + + align:start position:0% +it's called harmonic motion and B is + + + align:start position:0% +it's called harmonic motion and B is +zero. That's the key point. B is zero. + + align:start position:0% +zero. That's the key point. B is zero. + + + align:start position:0% +zero. That's the key point. B is zero. +So we have a it's Newton's law. And so a + + align:start position:0% +So we have a it's Newton's law. And so a + + + align:start position:0% +So we have a it's Newton's law. And so a +will be the mass m + + align:start position:0% +will be the mass m + + + align:start position:0% +will be the mass m +yblep prime second derivative + + align:start position:0% +yblep prime second derivative + + + align:start position:0% +yblep prime second derivative +b is zero + + align:start position:0% +b is zero + + + align:start position:0% +b is zero +later b will be a damping term a a + + align:start position:0% +later b will be a damping term a a + + + align:start position:0% +later b will be a damping term a a +friction term a resistance term but + + align:start position:0% +friction term a resistance term but + + + align:start position:0% +friction term a resistance term but +let's have that zero so we're going to + + align:start position:0% +let's have that zero so we're going to + + + align:start position:0% +let's have that zero so we're going to +have perpetual motion here plus the + + align:start position:0% +have perpetual motion here plus the + + + align:start position:0% +have perpetual motion here plus the +force so this is Newton's law m a is f= + + align:start position:0% +force so this is Newton's law m a is f= + + + align:start position:0% +force so this is Newton's law m a is f= +ma the force is proportional with a + + align:start position:0% +ma the force is proportional with a + + + align:start position:0% +ma the force is proportional with a +minus sign. So it's going to come on + + align:start position:0% +minus sign. So it's going to come on + + + align:start position:0% +minus sign. So it's going to come on +this side as a plus proportional + + align:start position:0% +this side as a plus proportional + + + align:start position:0% +this side as a plus proportional +to y. There's the equation. + + align:start position:0% +to y. There's the equation. + + + align:start position:0% +to y. There's the equation. +No, no y prime term. + + align:start position:0% +No, no y prime term. + + + align:start position:0% +No, no y prime term. +m yp prime + k y = z. + + align:start position:0% +m yp prime + k y = z. + + + align:start position:0% +m yp prime + k y = z. +Starting from an initial position and an + + align:start position:0% +Starting from an initial position and an + + + align:start position:0% +Starting from an initial position and an +initial velocity, it's like a spring + + align:start position:0% +initial velocity, it's like a spring + + + align:start position:0% +initial velocity, it's like a spring +going up and down. + + align:start position:0% +going up and down. + + + align:start position:0% +going up and down. +or a clock pendulum going going back and + + align:start position:0% +or a clock pendulum going going back and + + + align:start position:0% +or a clock pendulum going going back and +forth and it we'll see it it so it's + + align:start position:0% +forth and it we'll see it it so it's + + + align:start position:0% +forth and it we'll see it it so it's +going to be well we want to solve that + + align:start position:0% +going to be well we want to solve that + + + align:start position:0% +going to be well we want to solve that +equation + + align:start position:0% +equation + + + align:start position:0% +equation +so do we see solutions to that + + align:start position:0% +so do we see solutions to that + + + align:start position:0% +so do we see solutions to that +so if I had if m and k were one suppose + + align:start position:0% +so if I had if m and k were one suppose + + + align:start position:0% +so if I had if m and k were one suppose +m and k were one I'm looking for second + + align:start position:0% +m and k were one I'm looking for second + + + align:start position:0% +m and k were one I'm looking for second +derivative plus the function is zero + + align:start position:0% +derivative plus the function is zero + + + align:start position:0% +derivative plus the function is zero +second derivative is minus the function + + align:start position:0% +second derivative is minus the function + + + align:start position:0% +second derivative is minus the function +I Immediately think of sin t and cosine + + align:start position:0% +I Immediately think of sin t and cosine + + + align:start position:0% +I Immediately think of sin t and cosine +t ss and cosiness because the second + + align:start position:0% +t ss and cosiness because the second + + + align:start position:0% +t ss and cosiness because the second +derivative the first derivative of s is + + align:start position:0% +derivative the first derivative of s is + + + align:start position:0% +derivative the first derivative of s is +cosine the second derivative is minus + + align:start position:0% +cosine the second derivative is minus + + + align:start position:0% +cosine the second derivative is minus +the sign it gives us the minus sign here + + align:start position:0% +the sign it gives us the minus sign here + + + align:start position:0% +the sign it gives us the minus sign here +the plus sign there zero. So the the + + align:start position:0% +the plus sign there zero. So the the + + + align:start position:0% +the plus sign there zero. So the the +these special solutions here are y + + align:start position:0% +these special solutions here are y + + + align:start position:0% +these special solutions here are y +is this is the null I'm finding the null + + align:start position:0% +is this is the null I'm finding the null + + + align:start position:0% +is this is the null I'm finding the null +solution is let me call them c1 times + + align:start position:0% +solution is let me call them c1 times + + + align:start position:0% +solution is let me call them c1 times +the cosine and now I have to figure out + + align:start position:0% +the cosine and now I have to figure out + + + align:start position:0% +the cosine and now I have to figure out +the cosine of what + + align:start position:0% +the cosine of what + + + align:start position:0% +the cosine of what +I want the cosine + + align:start position:0% +I want the cosine + + + align:start position:0% +I want the cosine +to satisfy to be a null solution satisfy + + align:start position:0% +to satisfy to be a null solution satisfy + + + align:start position:0% +to satisfy to be a null solution satisfy +my equation let me put it in it there's + + align:start position:0% +my equation let me put it in it there's + + + align:start position:0% +my equation let me put it in it there's +a square root of k over mt + + align:start position:0% + + + + align:start position:0% + +and you have to see that if I take two + + align:start position:0% +and you have to see that if I take two + + + align:start position:0% +and you have to see that if I take two +derivatives of the cosine that will + + align:start position:0% +derivatives of the cosine that will + + + align:start position:0% +derivatives of the cosine that will +produce minus the cosine which I want + + align:start position:0% +produce minus the cosine which I want + + + align:start position:0% +produce minus the cosine which I want +and because of that the chain rule will + + align:start position:0% +and because of that the chain rule will + + + align:start position:0% +and because of that the chain rule will +bring out this square root twice so it + + align:start position:0% +bring out this square root twice so it + + + align:start position:0% +bring out this square root twice so it +will bring bring out the factor km m + + align:start position:0% +will bring bring out the factor km m + + + align:start position:0% +will bring bring out the factor km m +for yblep prime and that factor k / m. + + align:start position:0% +for yblep prime and that factor k / m. + + + align:start position:0% +for yblep prime and that factor k / m. +The m's will cancel and I'll have the k + + align:start position:0% +The m's will cancel and I'll have the k + + + align:start position:0% +The m's will cancel and I'll have the k +that matches that k. It's a solution. + + align:start position:0% +that matches that k. It's a solution. + + + align:start position:0% +that matches that k. It's a solution. +And the other solution is just like it. + + align:start position:0% +And the other solution is just like it. + + + align:start position:0% +And the other solution is just like it. +It's the sign + + align:start position:0% +It's the sign + + + align:start position:0% +It's the sign +of this square root of k / m t. + + align:start position:0% + + + + align:start position:0% + +That's worth putting a box around. + + align:start position:0% +That's worth putting a box around. + + + align:start position:0% +That's worth putting a box around. +That's what I mean by free harmonic + + align:start position:0% +That's what I mean by free harmonic + + + align:start position:0% +That's what I mean by free harmonic +motion. + + align:start position:0% +motion. + + + align:start position:0% +motion. +Something is just oscillating + + align:start position:0% +Something is just oscillating + + + align:start position:0% +Something is just oscillating +in rotation problem. Something is just + + align:start position:0% +in rotation problem. Something is just + + + align:start position:0% +in rotation problem. Something is just +going around a circle at a constant + + align:start position:0% +going around a circle at a constant + + + align:start position:0% +going around a circle at a constant +speed. So, and notice well notice I + + align:start position:0% +speed. So, and notice well notice I + + + align:start position:0% +speed. So, and notice well notice I +haven't + + align:start position:0% +haven't + + + align:start position:0% +haven't +these are not the same as those + + align:start position:0% +these are not the same as those + + + align:start position:0% +these are not the same as those +cosiness are related to exponentials but + + align:start position:0% +cosiness are related to exponentials but + + + align:start position:0% +cosiness are related to exponentials but +not identical. So I could write the + + align:start position:0% +not identical. So I could write the + + + align:start position:0% +not identical. So I could write the +answer this way with using cosine and s + + align:start position:0% +answer this way with using cosine and s + + + align:start position:0% +answer this way with using cosine and s +or as you'll see I can write the same + + align:start position:0% +or as you'll see I can write the same + + + align:start position:0% +or as you'll see I can write the same +the same formula using exponentials + + align:start position:0% +the same formula using exponentials + + + align:start position:0% +the same formula using exponentials +complex exponentials. Everybody + + align:start position:0% +complex exponentials. Everybody + + + align:start position:0% +complex exponentials. Everybody +remembers the big formula that allows + + align:start position:0% +remembers the big formula that allows + + + align:start position:0% +remembers the big formula that allows +complex numbers in here is Oiler's + + align:start position:0% +complex numbers in here is Oiler's + + + align:start position:0% +complex numbers in here is Oiler's +formula that the exponential of I omega + + align:start position:0% +formula that the exponential of I omega + + + align:start position:0% +formula that the exponential of I omega +t is the cosine plus i * the s of omega + + align:start position:0% +t is the cosine plus i * the s of omega + + + align:start position:0% +t is the cosine plus i * the s of omega +t. I'll write it again. That that that's + + align:start position:0% +t. I'll write it again. That that that's + + + align:start position:0% +t. I'll write it again. That that that's +a solution. It's got the two it's got + + align:start position:0% +a solution. It's got the two it's got + + + align:start position:0% +a solution. It's got the two it's got +two null solutions. They're independent. + + align:start position:0% +two null solutions. They're independent. + + + align:start position:0% +two null solutions. They're independent. +They're different. If we've got two + + align:start position:0% +They're different. If we've got two + + + align:start position:0% +They're different. If we've got two +constants, because our equation is + + align:start position:0% +constants, because our equation is + + + align:start position:0% +constants, because our equation is +linear, we can safely multiply by any + + align:start position:0% +linear, we can safely multiply by any + + + align:start position:0% +linear, we can safely multiply by any +constant and add solutions and they stay + + align:start position:0% +constant and add solutions and they stay + + + align:start position:0% +constant and add solutions and they stay +solutions because we have a linear + + align:start position:0% +solutions because we have a linear + + + align:start position:0% +solutions because we have a linear +equation and zero on the right hand + + align:start position:0% +equation and zero on the right hand + + + align:start position:0% +equation and zero on the right hand +side. Good. + + align:start position:0% +side. Good. + + + align:start position:0% +side. Good. +Uh, of course, we can't write this + + align:start position:0% +Uh, of course, we can't write this + + + align:start position:0% +Uh, of course, we can't write this +square root of a over m k over m + + align:start position:0% +square root of a over m k over m + + + align:start position:0% +square root of a over m k over m +forever. Let let me do what everybody + + align:start position:0% +forever. Let let me do what everybody + + + align:start position:0% +forever. Let let me do what everybody +does. Introduce omega. It's omega + + align:start position:0% +does. Introduce omega. It's omega + + + align:start position:0% +does. Introduce omega. It's omega +natural. The N here stands for the + + align:start position:0% +natural. The N here stands for the + + + align:start position:0% +natural. The N here stands for the +natural frequency. The frequency that + + align:start position:0% +natural frequency. The frequency that + + + align:start position:0% +natural frequency. The frequency that +that clock is going at. And that is the + + align:start position:0% +that clock is going at. And that is the + + + align:start position:0% +that clock is going at. And that is the +square root of K over M. + + align:start position:0% +square root of K over M. + + + align:start position:0% +square root of K over M. +So our equation, we could rewrite that + + align:start position:0% +So our equation, we could rewrite that + + + align:start position:0% +So our equation, we could rewrite that +equation. Let me rewrite that equation + + align:start position:0% +equation. Let me rewrite that equation + + + align:start position:0% +equation. Let me rewrite that equation +to make it simple. I'll divide by M. No + + align:start position:0% +to make it simple. I'll divide by M. No + + + align:start position:0% +to make it simple. I'll divide by M. No +problem to divide by M. So then I have + + align:start position:0% +problem to divide by M. So then I have + + + align:start position:0% +problem to divide by M. So then I have +yp prime plus k / m which is omega n^2 + + align:start position:0% +yp prime plus k / m which is omega n^2 + + + align:start position:0% +yp prime plus k / m which is omega n^2 +the natural frequency squared y equals + + align:start position:0% +the natural frequency squared y equals + + + align:start position:0% +the natural frequency squared y equals +zero. That's let's put a box around that + + align:start position:0% +zero. That's let's put a box around that + + + align:start position:0% +zero. That's let's put a box around that +one because that's you couldn't couldn't + + align:start position:0% +one because that's you couldn't couldn't + + + align:start position:0% +one because that's you couldn't couldn't +be better than that. The constant a is + + align:start position:0% +be better than that. The constant a is + + + align:start position:0% +be better than that. The constant a is +one. The constant b is zero. the + + align:start position:0% +one. The constant b is zero. the + + + align:start position:0% +one. The constant b is zero. the +constant C is a known omega n^ squ + + align:start position:0% +constant C is a known omega n^ squ + + + align:start position:0% +constant C is a known omega n^ squ +depending on the the the pendulum + + align:start position:0% +depending on the the the pendulum + + + align:start position:0% +depending on the the the pendulum +itself. Okay. And the solutions then + + align:start position:0% +itself. Okay. And the solutions then + + + align:start position:0% +itself. Okay. And the solutions then +I'll just copy this solution. Y null is + + align:start position:0% +I'll just copy this solution. Y null is + + + align:start position:0% +I'll just copy this solution. Y null is +c1 cosine of omega n t because omega n + + align:start position:0% +c1 cosine of omega n t because omega n + + + align:start position:0% +c1 cosine of omega n t because omega n +is that square root and c2 sine of omega + + align:start position:0% +is that square root and c2 sine of omega + + + align:start position:0% +is that square root and c2 sine of omega +n t. Oh well, wait a minute. I can + + align:start position:0% +n t. Oh well, wait a minute. I can + + + align:start position:0% +n t. Oh well, wait a minute. I can +figure out what C1 and C2 are. + + align:start position:0% +figure out what C1 and C2 are. + + + align:start position:0% +figure out what C1 and C2 are. +So + + align:start position:0% +So + + + align:start position:0% +So +coming from the initial conditions, + + align:start position:0% +coming from the initial conditions, + + + align:start position:0% +coming from the initial conditions, +right? The initial conditions. If I plug + + align:start position:0% +right? The initial conditions. If I plug + + + align:start position:0% +right? The initial conditions. If I plug +in t equals 0, + + align:start position:0% +in t equals 0, + + + align:start position:0% +in t equals 0, +then I want to get the answer y of 0. + + align:start position:0% +then I want to get the answer y of 0. + + + align:start position:0% +then I want to get the answer y of 0. +The the known initial condition, the + + align:start position:0% +The the known initial condition, the + + + align:start position:0% +The the known initial condition, the +place the pendulum started swinging + + align:start position:0% +place the pendulum started swinging + + + align:start position:0% +place the pendulum started swinging +from, the place the spring you you + + align:start position:0% +from, the place the spring you you + + + align:start position:0% +from, the place the spring you you +pulled the spring a distance y of 0, you + + align:start position:0% +pulled the spring a distance y of 0, you + + + align:start position:0% +pulled the spring a distance y of 0, you +let go + + align:start position:0% +let go + + + align:start position:0% +let go +at t equals 0. + + align:start position:0% +at t equals 0. + + + align:start position:0% +at t equals 0. +So I'm plugging in tals 0. At tals 0, + + align:start position:0% +So I'm plugging in tals 0. At tals 0, + + + align:start position:0% +So I'm plugging in tals 0. At tals 0, +that's zero. Forget the sign. This is + + align:start position:0% +that's zero. Forget the sign. This is + + + align:start position:0% +that's zero. Forget the sign. This is +one. So I I discover that C1 should be Y + + align:start position:0% +one. So I I discover that C1 should be Y + + + align:start position:0% +one. So I I discover that C1 should be Y +of zero. Simple. C1 is Y of zero + + align:start position:0% + + + + align:start position:0% + +because that gives me the right answer + + align:start position:0% +because that gives me the right answer + + + align:start position:0% +because that gives me the right answer +at T equals Z. And what about C2? Can I + + align:start position:0% +at T equals Z. And what about C2? Can I + + + align:start position:0% +at T equals Z. And what about C2? Can I +figure out C2? Well, that's going to + + align:start position:0% +figure out C2? Well, that's going to + + + align:start position:0% +figure out C2? Well, that's going to +involve the initial velocity, the + + align:start position:0% +involve the initial velocity, the + + + align:start position:0% +involve the initial velocity, the +derivative at t=0. + + align:start position:0% +derivative at t=0. + + + align:start position:0% +derivative at t=0. +So the der because the derivative of the + + align:start position:0% +So the der because the derivative of the + + + align:start position:0% +So the der because the derivative of the +sign is the cosine which equals 1 at t= + + align:start position:0% +sign is the cosine which equals 1 at t= + + + align:start position:0% +sign is the cosine which equals 1 at t= +0. + + align:start position:0% +0. + + + align:start position:0% +0. +The derivative of this is the sign which + + align:start position:0% +The derivative of this is the sign which + + + align:start position:0% +The derivative of this is the sign which +is zero. So the when I'm looking at y + + align:start position:0% +is zero. So the when I'm looking at y + + + align:start position:0% +is zero. So the when I'm looking at y +prime, the derivative, + + align:start position:0% +prime, the derivative, + + + align:start position:0% +prime, the derivative, +I'm looking here at t equals z. And I + + align:start position:0% +I'm looking here at t equals z. And I + + + align:start position:0% +I'm looking here at t equals z. And I +want y prime of zero. + + align:start position:0% +want y prime of zero. + + + align:start position:0% +want y prime of zero. +But I don't just want y prime of zero. + + align:start position:0% +But I don't just want y prime of zero. + + + align:start position:0% +But I don't just want y prime of zero. +Do you see that? That doesn't have the + + align:start position:0% +Do you see that? That doesn't have the + + + align:start position:0% +Do you see that? That doesn't have the +right derivative at t equals z. Because + + align:start position:0% +right derivative at t equals z. Because + + + align:start position:0% +right derivative at t equals z. Because +when I take the derivative and omega n, + + align:start position:0% +when I take the derivative and omega n, + + + align:start position:0% +when I take the derivative and omega n, +that constant, you remember that + + align:start position:0% +that constant, you remember that + + + align:start position:0% +that constant, you remember that +constant, the derivative of of this will + + align:start position:0% +constant, the derivative of of this will + + + align:start position:0% +constant, the derivative of of this will +bring out an omega n. So I better have + + align:start position:0% +bring out an omega n. So I better have + + + align:start position:0% +bring out an omega n. So I better have +an omega n down here to cancel it. And + + align:start position:0% +an omega n down here to cancel it. And + + + align:start position:0% +an omega n down here to cancel it. And +now I've got it. + + align:start position:0% +now I've got it. + + + align:start position:0% +now I've got it. +That tells me the motion + + align:start position:0% +That tells me the motion + + + align:start position:0% +That tells me the motion +forever and ever. + + align:start position:0% +forever and ever. + + + align:start position:0% +forever and ever. +Energy is constant. Potential energy + + align:start position:0% +Energy is constant. Potential energy + + + align:start position:0% +Energy is constant. Potential energy +plus kinetic energy. I could speak about + + align:start position:0% +plus kinetic energy. I could speak about + + + align:start position:0% +plus kinetic energy. I could speak about +energy but I won't. + + align:start position:0% +energy but I won't. + + + align:start position:0% +energy but I won't. +That's that motion continues forever. + + align:start position:0% +That's that motion continues forever. + + + align:start position:0% +That's that motion continues forever. +Free harmonic motion. Free harmonic + + align:start position:0% +Free harmonic motion. Free harmonic + + + align:start position:0% +Free harmonic motion. Free harmonic +motion. Okay. It it goes on and on. + + align:start position:0% +motion. Okay. It it goes on and on. + + + align:start position:0% +motion. Okay. It it goes on and on. +Okay. And again, uh, I could write this + + align:start position:0% +Okay. And again, uh, I could write this + + + align:start position:0% +Okay. And again, uh, I could write this +in terms of complex exponentials, but + + align:start position:0% +in terms of complex exponentials, but + + + align:start position:0% +in terms of complex exponentials, but +I'm pretty happy with that form. It's + + align:start position:0% +I'm pretty happy with that form. It's + + + align:start position:0% +I'm pretty happy with that form. It's +hard to beat that form. Okay. So, uh, + + align:start position:0% +hard to beat that form. Okay. So, uh, + + + align:start position:0% +hard to beat that form. Okay. So, uh, +what else to what else to do here? First + + align:start position:0% +what else to what else to do here? First + + + align:start position:0% +what else to what else to do here? First +of all, we're going to have + + align:start position:0% +of all, we're going to have + + + align:start position:0% +of all, we're going to have +cosine omega t's for quite a while. + + align:start position:0% +cosine omega t's for quite a while. + + + align:start position:0% +cosine omega t's for quite a while. +I better d draw the graph of that simple + + align:start position:0% +I better d draw the graph of that simple + + + align:start position:0% +I better d draw the graph of that simple +familiar function. And + + align:start position:0% +familiar function. And + + + align:start position:0% +familiar function. And +so here's a graph of cosine omega t. So + + align:start position:0% +so here's a graph of cosine omega t. So + + + align:start position:0% +so here's a graph of cosine omega t. So +here's t, + + align:start position:0% +here's t, + + + align:start position:0% +here's t, +here's cosine of omega, here's zero, + + align:start position:0% +here's cosine of omega, here's zero, + + + align:start position:0% +here's cosine of omega, here's zero, +here's two. Well, let me see what I get. + + align:start position:0% +here's two. Well, let me see what I get. + + + align:start position:0% +here's two. Well, let me see what I get. +So I go cosine of omega. Cosine of omega + + align:start position:0% +So I go cosine of omega. Cosine of omega + + + align:start position:0% +So I go cosine of omega. Cosine of omega +t is what I'm drawing. Not cosine t. + + align:start position:0% +t is what I'm drawing. Not cosine t. + + + align:start position:0% +t is what I'm drawing. Not cosine t. +Cosine t would go 0 to 2 pi. But I have + + align:start position:0% +Cosine t would go 0 to 2 pi. But I have + + + align:start position:0% +Cosine t would go 0 to 2 pi. But I have +cosine of omega t. So cosine of omega t + + align:start position:0% +cosine of omega t. So cosine of omega t + + + align:start position:0% +cosine of omega t. So cosine of omega t +is what I want to graph. So it starts at + + align:start position:0% +is what I want to graph. So it starts at + + + align:start position:0% +is what I want to graph. So it starts at +at one and it comes back it drops comes + + align:start position:0% +at one and it comes back it drops comes + + + align:start position:0% +at one and it comes back it drops comes +back up comes back to one. But what is + + align:start position:0% +back up comes back to one. But what is + + + align:start position:0% +back up comes back to one. But what is +this t final? + + align:start position:0% +this t final? + + + align:start position:0% +this t final? +The the period this t is the period + + align:start position:0% +The the period this t is the period + + + align:start position:0% +The the period this t is the period +of the oscillation. + + align:start position:0% +of the oscillation. + + + align:start position:0% +of the oscillation. +It's the time it takes for the swing to + + align:start position:0% +It's the time it takes for the swing to + + + align:start position:0% +It's the time it takes for the swing to +go up and back. It's And what is that? + + align:start position:0% +go up and back. It's And what is that? + + + align:start position:0% +go up and back. It's And what is that? +That would be So I'm looking So I'm + + align:start position:0% +That would be So I'm looking So I'm + + + align:start position:0% +That would be So I'm looking So I'm +graphing coine of omega t is what I'm + + align:start position:0% +graphing coine of omega t is what I'm + + + align:start position:0% +graphing coine of omega t is what I'm +graphing. + + align:start position:0% + + + + align:start position:0% + +So omega t starts out at zero where t is + + align:start position:0% +So omega t starts out at zero where t is + + + align:start position:0% +So omega t starts out at zero where t is +zero and it goes up to So I want omega + + align:start position:0% +zero and it goes up to So I want omega + + + align:start position:0% +zero and it goes up to So I want omega +t. when I get here this omega t should + + align:start position:0% +t. when I get here this omega t should + + + align:start position:0% +t. when I get here this omega t should +be 2 pi + + align:start position:0% + + + + align:start position:0% + +right + + align:start position:0% +right + + + align:start position:0% +right +then I've completed the cosine + + align:start position:0% +then I've completed the cosine + + + align:start position:0% +then I've completed the cosine +uh one + + align:start position:0% +uh one + + + align:start position:0% +uh one +one uh rotation around the circle one + + align:start position:0% +one uh rotation around the circle one + + + align:start position:0% +one uh rotation around the circle one +movement of the pendulum back and forth + + align:start position:0% +movement of the pendulum back and forth + + + align:start position:0% +movement of the pendulum back and forth +is in that picture now okay so omega t + + align:start position:0% +is in that picture now okay so omega t + + + align:start position:0% +is in that picture now okay so omega t +is 2 pi right + + align:start position:0% +is 2 pi right + + + align:start position:0% +is 2 pi right +the period is t. I think of omega as the + + align:start position:0% +the period is t. I think of omega as the + + + align:start position:0% +the period is t. I think of omega as the +circular frequency. Omega is in Omega is + + align:start position:0% +circular frequency. Omega is in Omega is + + + align:start position:0% +circular frequency. Omega is in Omega is +in radians + + align:start position:0% + + + + align:start position:0% + +per + + align:start position:0% +per + + + align:start position:0% +per +second. + + align:start position:0% + + + + align:start position:0% + +That's that's my that's the units. And + + align:start position:0% +That's that's my that's the units. And + + + align:start position:0% +That's that's my that's the units. And +units truly are important to keep track. + + align:start position:0% +units truly are important to keep track. + + + align:start position:0% +units truly are important to keep track. +O omega that's omega radians per second + + align:start position:0% +O omega that's omega radians per second + + + align:start position:0% +O omega that's omega radians per second +when I multiply by the period the t in + + align:start position:0% +when I multiply by the period the t in + + + align:start position:0% +when I multiply by the period the t in +seconds I get 2 pi radians okay now in + + align:start position:0% +seconds I get 2 pi radians okay now in + + + align:start position:0% +seconds I get 2 pi radians okay now in +engineers and in everyday use there's + + align:start position:0% +engineers and in everyday use there's + + + align:start position:0% +engineers and in everyday use there's +another frequency + + align:start position:0% +another frequency + + + align:start position:0% +another frequency +called f for frequency probably okay so + + align:start position:0% +called f for frequency probably okay so + + + align:start position:0% +called f for frequency probably okay so +f you should know about f + + align:start position:0% +f you should know about f + + + align:start position:0% +f you should know about f +and its frequency is in hertz. So f is + + align:start position:0% +and its frequency is in hertz. So f is + + + align:start position:0% +and its frequency is in hertz. So f is +measured in hertz. + + align:start position:0% +measured in hertz. + + + align:start position:0% +measured in hertz. +H e r tz. + + align:start position:0% +H e r tz. + + + align:start position:0% +H e r tz. +H er tz + + align:start position:0% + + + + align:start position:0% + +named after the guy, not the tomato + + align:start position:0% +named after the guy, not the tomato + + + align:start position:0% +named after the guy, not the tomato +uh ketchup guy, but the Oh, that's + + align:start position:0% +uh ketchup guy, but the Oh, that's + + + align:start position:0% +uh ketchup guy, but the Oh, that's +hints. Anyway, sorry about that. Uh + + align:start position:0% +hints. Anyway, sorry about that. Uh + + + align:start position:0% +hints. Anyway, sorry about that. Uh +Herz, + + align:start position:0% +Herz, + + + align:start position:0% +Herz, +not the car. That's what I was trying to + + align:start position:0% +not the car. That's what I was trying to + + + align:start position:0% +not the car. That's what I was trying to +say. but the the German guy who + + align:start position:0% +say. but the the German guy who + + + align:start position:0% +say. but the the German guy who +was involved early with this stuff. So + + align:start position:0% +was involved early with this stuff. So + + + align:start position:0% +was involved early with this stuff. So +what is f? + + align:start position:0% +what is f? + + + align:start position:0% +what is f? +F is + + align:start position:0% +F is + + + align:start position:0% +F is +one. F * t is one. Instead of dealing + + align:start position:0% +one. F * t is one. Instead of dealing + + + align:start position:0% +one. F * t is one. Instead of dealing +with 2 pi, which counts radians, the one + + align:start position:0% +with 2 pi, which counts radians, the one + + + align:start position:0% +with 2 pi, which counts radians, the one +just counts complete loops, complete + + align:start position:0% +just counts complete loops, complete + + + align:start position:0% +just counts complete loops, complete +oscillations. So, so, so f f compared to + + align:start position:0% +oscillations. So, so, so f f compared to + + + align:start position:0% +oscillations. So, so, so f f compared to +omega uh f is smaller by a factor 2 pi. + + align:start position:0% +omega uh f is smaller by a factor 2 pi. + + + align:start position:0% +omega uh f is smaller by a factor 2 pi. +So, f * t is 1. f is 1 / t. Omega is 2 + + align:start position:0% +So, f * t is 1. f is 1 / t. Omega is 2 + + + align:start position:0% +So, f * t is 1. f is 1 / t. Omega is 2 +pi / t. So, putting these together, all + + align:start position:0% +pi / t. So, putting these together, all + + + align:start position:0% +pi / t. So, putting these together, all +I'm saying is omega is 2<unk>i * f. + + align:start position:0% +I'm saying is omega is 2<unk>i * f. + + + align:start position:0% +I'm saying is omega is 2<unk>i * f. +So when we say we're getting 60 cycles, + + align:start position:0% +So when we say we're getting 60 cycles, + + + align:start position:0% +So when we say we're getting 60 cycles, +so that's what I would measure TF in. FF + + align:start position:0% +so that's what I would measure TF in. FF + + + align:start position:0% +so that's what I would measure TF in. FF +would be in cycles + + align:start position:0% +would be in cycles + + + align:start position:0% +would be in cycles +is cycles + + align:start position:0% +is cycles + + + align:start position:0% +is cycles +per second. + + align:start position:0% + + + + align:start position:0% + +One cycle, 2 pi radians. + + align:start position:0% + + + + align:start position:0% + +This isn't big heavy math, but it's more + + align:start position:0% +This isn't big heavy math, but it's more + + + align:start position:0% +This isn't big heavy math, but it's more +important than a lot of math just to get + + align:start position:0% +important than a lot of math just to get + + + align:start position:0% +important than a lot of math just to get +these + + align:start position:0% +these + + + align:start position:0% +these +letters straight. So there's capital T, + + align:start position:0% +letters straight. So there's capital T, + + + align:start position:0% +letters straight. So there's capital T, +the period, and two measures of + + align:start position:0% +the period, and two measures of + + + align:start position:0% +the period, and two measures of +frequency. One is omega in radians per + + align:start position:0% +frequency. One is omega in radians per + + + align:start position:0% +frequency. One is omega in radians per +second, and the other is F in cycle, + + align:start position:0% +second, and the other is F in cycle, + + + align:start position:0% +second, and the other is F in cycle, +full cycles per second. So one is 2 pi + + align:start position:0% +full cycles per second. So one is 2 pi + + + align:start position:0% +full cycles per second. So one is 2 pi +times the other. Good. Okay. And we have + + align:start position:0% +times the other. Good. Okay. And we have + + + align:start position:0% +times the other. Good. Okay. And we have +this. Okay. I think we're uh + + align:start position:0% +this. Okay. I think we're uh + + + align:start position:0% +this. Okay. I think we're uh +we've got the key ideas here then for + + align:start position:0% +we've got the key ideas here then for + + + align:start position:0% +we've got the key ideas here then for +unforced motion pure oscillation going + + align:start position:0% +unforced motion pure oscillation going + + + align:start position:0% +unforced motion pure oscillation going +on forever. + + align:start position:0% +on forever. + + + align:start position:0% +on forever. +And uh let me just + + align:start position:0% +And uh let me just + + + align:start position:0% +And uh let me just +write what I already mentioned. A + + align:start position:0% +write what I already mentioned. A + + + align:start position:0% +write what I already mentioned. A +different way to express y would be with + + align:start position:0% +different way to express y would be with + + + align:start position:0% +different way to express y would be with +small c's + + align:start position:0% +small c's + + + align:start position:0% +small c's +e to the i omega n t and c2 e to the + + align:start position:0% +e to the i omega n t and c2 e to the + + + align:start position:0% +e to the i omega n t and c2 e to the +minus i omega n t. All I'm saying is + + align:start position:0% +minus i omega n t. All I'm saying is + + + align:start position:0% +minus i omega n t. All I'm saying is +that this form with exponentials + + align:start position:0% +that this form with exponentials + + + align:start position:0% +that this form with exponentials +is is entirely equivalent to this form + + align:start position:0% +is is entirely equivalent to this form + + + align:start position:0% +is is entirely equivalent to this form +with cosine and sign. + + align:start position:0% +with cosine and sign. + + + align:start position:0% +with cosine and sign. +That form allows me two constants + + align:start position:0% +That form allows me two constants + + + align:start position:0% +That form allows me two constants +capital C1 and C2. This form allows me + + align:start position:0% +capital C1 and C2. This form allows me + + + align:start position:0% +capital C1 and C2. This form allows me +two constants little one and C C2. And + + align:start position:0% +two constants little one and C C2. And + + + align:start position:0% +two constants little one and C C2. And +from that I have that. From this I have + + align:start position:0% +from that I have that. From this I have + + + align:start position:0% +from that I have that. From this I have +this. So So we really do have + + align:start position:0% +this. So So we really do have + + + align:start position:0% +this. So So we really do have +exponentials here. And the key message + + align:start position:0% +exponentials here. And the key message + + + align:start position:0% +exponentials here. And the key message +is that for pure oscillation those + + align:start position:0% +is that for pure oscillation those + + + align:start position:0% +is that for pure oscillation those +exponentials are pure imaginary exponent + + align:start position:0% +exponentials are pure imaginary exponent + + + align:start position:0% +exponentials are pure imaginary exponent +i omega nt. Okay that's the best example + + align:start position:0% +i omega nt. Okay that's the best example + + + align:start position:0% +i omega nt. Okay that's the best example +the simplest example the first example. + + align:start position:0% +the simplest example the first example. + + + align:start position:0% +the simplest example the first example. +Thanks. \ No newline at end of file diff --git a/xgUCzL3TD1g.txt b/xgUCzL3TD1g.txt new file mode 100644 index 0000000000000000000000000000000000000000..244575924159079a09c7adc8aa48656f113a5e50 --- /dev/null +++ b/xgUCzL3TD1g.txt @@ -0,0 +1,2031 @@ +The following content is +provided under a Creative + +Commons license. + +Your support will help MIT +OpenCourseWare continue to + +offer high quality educational +resources for free. + +To make a donation or view +additional materials from + +hundreds of MIT courses, visit +MIT OpenCourseWare at + +ocw.mit.edu. + +PROFESSOR: So, last time we +started in on a discussion of + +a new topic, with was +statistical mechanics. + +So what we're trying to do now +is revisit the thermodynamics + +that we've spent most of the +term deriving and trying to + +use in a microscopic approach. + +So our hope is to be able to +start with a microscopic model + +of matter, starting with atoms +and molecules that we + +know are out there. + +And formulate thermodynamics +starting from that microscopic + +point of view. + +In contrast to the way it was +first formulated historically, + +and the way we've presented it +also, which is as an entirely + +empirical subject based on +macroscopic observation and + +deduction from that. + +So, we looked at the +probabilities that states with + +different energies would be +occupied and we inferred that + +there would be a simple way to +describe the distribution of + +atoms or molecules in states +of different levels. + +First of all, although I didn't +state it explicitly, + +essentially assumed there is +that if I've got a bunch of + +molecules, and I've got states +that they could be in of equal + +energy, then the probability +that they would be in one or + +another of those states +is the same. + +If the energies of the states +are equal, the probabilities + +that those states will +be occupied. + +That they'll be populated by +molecules, will be equal. + +And then we deduced what's +called the Boltzmann + +probability distribution. + +Which says that the probability +that a molecular + +state, i, will be occupied is +proportional to e to the minus + +Ei over kT, where little +Ei is the energy of + +that molecular state. + +And then realizing that the +probability that some state + +out there has to be occupied, +we saw that of course if we + +sum over all these probabilities +that sum has to + +equal one, right? + +In other words, the sum +over all of i of P of + +i is equal to one. + +So that means that we could +write not just that this is + +proportional to this, but we +could write that Pi is equal + +to e to the minus Ei over +kT divided by the + +sum of all such terms. + +So now we know how to figure +out how likely it is that a + +certain state is occupied. + +And what it means is, let's say +we have a whole bunch of + +states whose energy is pretty +low compared to kT. kT, the + +Boltzmann constant times +temperature is energy units. + +So if it's pretty warm, maybe +it's room temperature, maybe + +it's warmer. + +And there are a whole lot of +states that are accessible + +because the energies +are less than kT. + +What does that mean? + +That means that you could put a +bunch of different i's here + +whose energies are all quite +low compared to kT. + +And they'll all have significant +probabilities. + +Now let's decrease the energy. + +Go to cold temperature. + +So kT becomes really small. + +So that e to the minus energy +over kT starts to, if this + +gets to be bigger than kT by a +lot, then this whole thing is + +a very small number. + +Suddenly, you get very few +states accessible. + +So if we just plot this +distribution, of course it's + +easy to do, it's just a +decaying exponential. + +So Pi, which is a +function of Ei. + +It just looks like this. + +And here are a bunch +of states. + +And if we have a classical +mechanics picture of matter, + +then there would just be +continuous states. + +And if we have a quantum +mechanical picture of matter, + +there might be individual states +with gaps in between + +the energies. + +Either way, what happens, what +this is saying is, if we go + +out to higher and higher +energies, then you have a + +smaller and smaller probability +to be in + +a state like that. + +And if you go to low energies, +the probability gets bigger. + +And it depends on temperature. + +Because it's the ratio between +the energy and kT that + +dictates the size +of that term. + +So let's say this is moderate +temperature. + +If we go to low temperature, it +might look more like this. + +Hardly any states can be +occupied because even states + +of rather moderate energies, +suddenly now those energies + +are much bigger than kT. + +In other words, kT is measuring +thermal energy. + +It's saying there's not enough +thermal energy to populate, to + +knock things into states +whose energy is + +much higher than that. + +So you have a very precipitous +decay. + +If you go to the other +extreme, of very high + +temperature, then this will +tend to flatten out. + +Eventually it'll decay, but +it may take a long time. + +Because now kT is enormous. + +So the energy has to +get to be very big. + +Before it's bigger than kT. + +And as long as it +isn't, then this + +exponential term is not small. + +So there be a whole bunch of +states that may be occupied. + +In other words, a whole bunch +of states that are thermally + +accessible at equilibrium. + +Systems at thermal equilibrium, +molecules are + +getting knocked around +with whatever + +thermal energy is available. + +Crashing into each other or into +the walls of a vessel. + +And there'll be a distribution +of molecular energies. + +And that distribution is skewed +either low or high + +depending on the temperature. + +So that's what that +distribution, the Boltzmann + +distribution, is telling us. + +This is often called a Boltzmann +factor, because it's + +telling what the population of +some particular state is. + +OK. + +Now, this is just dealing with +individual molecule states. + +Then we said, OK, what about +the whole system? + +Well, the same kind of relation +holds there, too. + +In other words, if these are +individual molecule energies, + +now if I look at the entire +system, right well, still, + +there's no reason that same +distribution doesn't hold. + +And it does. + +So in other words, Pi of Ei, +that's the whole system + +energy, is e to the minus Ei +over kT, over the sum over i, + +Ei over kT. + +Now, this i doesn't refer to +a single molecule state. + +We're talking about +a whole system. + +It might be a mole of atoms or +molecules in the gas phase, or + +what have you. + +It refers to a system state +where the energy, the state of + +every one of those atoms or +molecules is specified. + +So this is a system +microstate. + +Every molecular state +is specified. + +So for a mole of stuff, that +means there might be 10 to the + +24 or so molecular states that +this single subscript is + +indicating. + +But the point is, those +states exist. + +They have a total energy. + +What's the probability that the +whole system will be in + +such a state? + +Still going to be proportional +to the total system energy. + +It turns out that these +summations end up taking on an + +enormous importance in +statistical mechanics. + +And the reason is, as we'll see +shortly, it turns out that + +every single macroscopic +thermodynamic function can be + +derived by knowing just that. + +Just these sums, what are called +partition functions. + +So of course they take on +enormous importance. + +So, we call them partition +functions because what they're + +doing is, they're indicating +how the molecules are + +partitioned among the different +available levels. + +The molecules or +a whole system. + +So the molecular partition +function is labeled little q. + +And the system partition +function is labeled big Q. + +It's called the canonical +partition function. + +And because they are going +to take on such special + +importance, let's just look at +some of their properties for + +different kinds of systems +and in general. + +OK, first of all, let's talk +about units and values. + +They are unitless. + +This is an exponential +function. + +Here are units of energy +and energy. + +But this is a unitless +was number. + +It's just some number, right? + +Could be 1. + +Could be 10. + +Could be 50. + +Whatever, right? + +Could be 10 to the 24. + +Its magnitude tells you about +more or less how many states + +are thermally accessible. + +Because, look at it. + +And then go back to the example +that I showed you if + +lots of these terms are big, are +significant because this + +is really a big number, right? + +It's really hot. + +So lots of states have energies +lower than kT, which + +means this is not too small, for +lots and lots of values of + +i, then this just +keeps adding up. + +And of course, same here. + +So the number might +be very large. + +But if we're in the low +temperature limit, maybe we're + +in such low temperature that +only the lowest possible state + +is occupied. + +And everything else, +it's just too cold. + +There's not enough thermal +energy to occupy anything but + +the very lowest state +available. + +Well, in that case the lowest +state, this would be one. + +Essentially we could +label this zero. + +We could put the energy, the +zero of energy there. + +Everything else is really big +compared to kT, which means + +this exponential gets to be a +really small number for every + +state except one. + +And this is just equal to one. + +In other words, the magnitude +of these numbers tells us + +about how many states are +accessible, thermally + +accessible, to molecules +or to a whole system. + +So let's just go through a +couple of specific examples to + +try to make that a little +more concrete. + +One is, let's start in +the simplest case. + +Which it'll turn out +I just alluded to. + +Let's consider a perfect atomic +crystal at essentially + +zero degrees Kelvin. + +Zero Kelvin. + +So every atom. + +Or even if it's a molecular +crystal, every molecule, + +they're all in the +ground state. + +There's no excess +thermal energy. + +Every molecule is in +its proper place. + +Every atom, if it's +an atomic lattice. + +In other words, it's in +the ground state. + +That's it. + +So again, we can place the +zero where we like. + +We'll place it there. + +That one, for that one state, +this will be equal to one. + +And for everything else +it'll be zero. + +So Q is just the sum of e +to the minus Ei over kT. + +It's equal to e to the minus +zero over kT plus e to the + +minus E1 over kT plus e to +the minus E2 over kT. + +But remember, T is +really tiny. + +It's almost zero +degrees Kelvin. + +So all these things are +much bigger than that. + +So this is vanishingly small. + +This is vanishingly small. + +The whole thing is approximately +equal to one. + +That's it. + +Also, if we say OK, now what's +the probability of the system + +being in a particular state. + +Well, we have an expression +for that. + +So let's look at P0. + +It's e to the minus E0 +over kT over the sum. + +Which we've just seen. + +So it's e to the minus E0 over +to kT divided by e to the + +minus E0 over kT plus e to the +minus E1 over kT, and so on. + +This is the only term +that's significant. + +So it's approximately +equal to one. + +Now, while I've got this written +here, let's just make + +sure we've got something +clear. + +What if we hadn't arbitrarily +set the zero of + +energy equal to zero? + +I mean, it's arbitrary, right? + +We can put the zero of +energy anywhere. + +And you might think, well, gee +that's going to have a big + +effect on everything. + +Well, it would have an effect +on the actual number that we + +get for Q. But what you'll see +is that any measurable + +quantity that we calculate +won't be affected. + +It's only the zero of the energy +scale that's going to + +be affected. + +So for example, let's look +at this probability. + +It doesn't matter where we +put the zero of energy. + +This term is still going +to be enormously bigger + +then the next one. + +And the next one. + +And the next one. + +So in this sum only this term +is going to matter. + +It's going to cancel +with this term. + +So whether or not these +individual terms are equal to + +one, which happens if we set +this to zero, or whether + +they're equal to some +other number. + +Still, the probability that the +system is in the lowest + +state is one, right? + +That doesn't depend on where we +arbitrarily put the zero of + +the energy scale. + +The state is still going to +be in the ground state, at + +essentially zero +degrees Kelvin. + +And it'll turn out to be that +way with any property that we + +can measure. + +Only the zero of this scale +moves if we arbitrarily move + +it somewhere. + +But the observable, measurable +quantities that we calculate, + +they won't change. + +Other than that scale. + +So that's one simple example. + +Now let's look at +another example. + +Let's consider a mole of atoms, +roaming around in the + +gas phase at room temperature. + +OK, so now what I want to do +is just have a simple model + +for their translational +motion. + +And of course, we could +do that either quantum + +mechanically or classically +solve for that. + +We're going to use an +even simpler model. + +And this model is going to be +very, very useful for a lot of + +the things that we'll treat. + +It's called a lattice model. + +All it means is, we're +going to divide up + +the available volume. + +This room, for example, +into zillions + +of tiny little elements. + +Little volume elements. + +Each one about the +size of an atom. + +The idea being, we're going to +specify the state of the atom + +by saying where is it. + +Is it in this lattice sight, +in this one, in this + +one, in this one. + +So it's a lattice model. + +Might be an atom there. + +Might be one there. + +So we're going to divide +the volume up. + +So let's call our atomic volume +little v. Our total + +volume big V. And an atomic +volume, it's going to be on + +the order of 1 angstroms +cubed. + +Or 10 to the minus +30 meters cubed. + +And our room, our volume +macroscopic one, might be on + +the order of one meter cubed. + +Ordinary sort of size. + +So now let's figure out our +molecular partition function. + +Now, implicit in this, we're +basically saying that the + +energy, the translational +energy, is basically zero. + +In other words, all these states +have the same energy. + +They're just located in +different positions. + +At any given instant of time. + +And what that means is all +these terms, all these + +Boltzmann factors, we just +set them equal to one. + +We'll set the zero of energy +there, be done with it. + +It's a simple model. + +But it's going to give us the +right order of magnitude that + +we're after. + +So, how many states are there +that are accessible? + +Well, on the order of 10 +to the 30th, right? + +So q, little q, we'll call it +little q translational, it's + +just discussing where +things are. + +Is on the order of +10 to the 30th. + +And if we do a more careful +treatment, if we treat the + +translational energy of atoms, +either classically or quantum + +mechanically and solve it. + +We'll still get, we still +do get, about the + +same order of magnitude. + +Now let's treat the +whole system. + +So, what happens? + +What are our total +possible states? + +Because we have to add this up +for every possible state. + +Well, let's start with +the first atom. + +It has to be somewhere. + +It has 10 to the 30th +possibilities for + +where it can be. + +Let's start with the +second atom. + +And put it somewhere. + +Well, it has 10 to the 30th +minus one, which is still + +pretty close to 10 +to the 30th. + +Let's let's go to +the third atom. + +And the fourth. + +If we have about a mole of +atoms, let's say 10 to the + +24th atoms, that's still going +to occupy a very small + +fraction of the site. + +Only one in a million. + +So we don't have to keep +careful track. + +Every one of them, we can just +say, look, there are 10 to the + +30th available sites. + +Because we're not going to worry +about a change in one in + +a millionth. + +So what that means is, capital +Q, trans for the system, is 10 + +to the 30th times +10 to the 30th. + +In other words, let's now +take the whole state. + +Well, I could put +atom one here. + +I have 10 to the 30th +possibilities. + +Atom two, I can put +anywhere else. + +So the joint probability of +that particular state, for + +just the two atoms, is 10th to +the 30th times 10 to the 30th. + +It's 10 to the 30th squared. + +So this is going +to keep going. + +It's going to be 10 to the +30th to the Nth power. + +Where N is the number +of atoms, which + +is 10 of the 24th. + +Huge number, right? + +It is a huge number. + +And that, too, if we treat the +whole thing classically or + +quantum mechanically and +work it all out. + +We'll get that number. + +Or something on that order. + +Because you know there really +is a simply astronomical + +number of states accessible to +the whole bunch of atoms or + +molecules in this room. + +It really is that big. + +So in other words, capital +Q is just an + +astronomical number. + +And it is the case. + +OK. + +There's an important +sort of nuance + +that we need to introduce. + +And it's the following. + +Turns out, it is an astronomical +number. + +But a tiny bit less astronomical +than what I've + +treated so far would indicate. + +So let's look a little +more carefully. + +What I've said is that Q +translational is little q + +translational, that is, that +10 to the 30th number. + +To the Nth power. + +But there's one failing here. + +Which is, when I got that, when +I decided that if I have + +just the first two atoms I've +got 10th to the 30th times 10 + +to the 30th possible states, the +trouble with that is then + +if I keep counting all the +possible atoms starting with + +each one, I'll double-count +it, right? + +In other words, what if I +interchange those two atoms? + +Well, those states are +identical, right? + +Indistinguishable. + +And it's only distinguishable +states that count. + +When you specify these +things, these are + +indicating distinct states. + +In some way, at least in + +principle, measurably different. + +If the atom's are identical, in +other words, if it's a mole + +of the same stuff, I don't have +a way of distinguishing + +between those two. + +I have to correct for that. + +And when I come to the third +atom, I have to correct for + +all the possible interchanges. + +Of course, it's three +factorial. + +And in general, it's +N factorial. + +So this result needs +to be modified. + +This is true for distinguishable +particles. + +In other words, if I had all +different atoms, so I could + +label them all, then I don't +have that correction. + +Because then there's really a +difference between that state + +and the state with the two +atoms interchanged. + +But if it's a mole of identical +atoms, that's no + +longer the case. + +So then, Q translational is +little q translational to the + +N power divided by +N factorial. + +It's still going to be an +absolutely enormous number. + +But it's going to be a little +less absolutely enormous than + +it was a minute ago. + +Now finally, I just want +to introduce a handy + +approximation to N factorial +that's going to turn out to be + +very useful again and again. + +And that's called Stirling's +approximation. + +For the log of a big number, +ln N factorial is N log N + +minus N. If we take e to those, +both sides, then we + +find that N factorial is equal +to e to the minus N + +N to the nth power. + +So this, then, is approximately +equal to q + +translational to +the Nth power. + +Over N to the N times e to the +minus N. Now let's put the + +numbers back in. + +There's our 10 to the 30th to +the 10 to the 24th power. + +And now we're going to diminish +that just a bit. + +It's N to the Nth power. + +So it's 10 to the 24th to the +10 to the 24th power. + +Times e to the minus 10 +to the 24th power. + +So, we can cancel +something here. + +So we have 10 to the 6th to the +10 to the 24th power times + +e to the 10 to the 24th +power. e is about 10 + +to the 0.4th power. + +So this whole thing is about 10 +to the 6.4th power to the + +10 to the 24th power +It's still a + +pretty respectable number. + +You could still say +astronomical. + +But maybe astronomical, +but not quite to + +the edge of the universe. + +Whereas the one before maybe hit +the edge of the universe + +and then beyond. + +So that's our second example. + +And again, part of what I'm +trying to do here is just + +introduce some ideas. + +Things like this +way of modeling + +positions and so forth. + +But also, again, orders +of magnitude. + +How big are these numbers. + +For different sorts +of systems. + +So let's do one more example. + +Now, let's consider a +polymer in a liquid. + +And it has different +configurations. + +And they might be a little +bit different in energy. + +For example, some configurations +might bring + +neighboring regions of the +polymer into proximity where + +they could hydrogen bond. + +And the point is that then the +molecular energies involved + +will change a little bit. + +Because of some sorts of +interactions that are possible + +in some configurations. + +And not in other +configurations. + +So what I'm trying to do is +introduce a very simple + +framework through which we +might be able to look at + +things like protein folding, +or DNA hydrogen bonding. + +Things like this. + +And just in a simple way model +how those work and what the + +forces are that drive them. + +So we'll think about polymer +configurations. + +So let's look at a few +configurations. + +Here is going to be one. + +I'm going to label +this one here. + +And then here are +a few others. + +So I've labeled them this way +so that you can see how they + +are distinct from each other. + +This one would have a possible +interaction. + +So we'll label its energy. + +So this is molecular state +i, here's going to + +be our energy, Ei. + +And let's call this one +negative e int, for an + +interaction energy +that's favorable. + +And these will be zero. + +Let's just put that there. + +Zero, zero, zero. + +And let's also indicate +the degeneracy. + +How many states, different +states are there + +with the same energy. + +And that's called gi. + +And here it's one. + +And here are these three. + +So that's the framework +of our model. + +Well, so what's our molecular +partition function for this + +configurational degree +of freedom? + +Well, we can label it little +q configurational. + +So we're going to sum over these +states. e to the minus + +Ei for the different +configurations over kT. + +So it's e to the +e int over kT. + +Plus three times e to the zero +over kT, we'll get all those + +other three terms. + +So that's it. + +It's e to the e int over +kT plus three. + +Remember, the interaction energy +is negative e int. + +It's a favorable interaction. +e int is a positive number. + +So that's our result. + +Now we've described the +probabilities in terms of the + +states that can be occupied. + +That is, we've added it up. + +But of course, even the way +I wrote it just out of + +convenience, I didn't +actually write out + +each term in the sum. + +In the notes I actually +did that. + +But of course it's not necessary +to write e to the + +zero over kT plus e to the zero +over kT and write that + +three times for each +of these three. + +Rather, it's convenient to +group them together. + +And the point I'm illustrating +here is that in our + +expression, for the partition +function, we've written that + +in terms of the individual +states. + +But we doing a sum over the +individual molecular states. + +But we could also sum +over energy levels. + +Including the degeneracy. + +So we could say, let's not do +the sum over every state. + +After all, what if there are a +hundred states that had the + +same energy. + +Rather than just three. + +Gets to be kind of +painful, right? + +Instead let's just sum +over energy levels. + +They're all going to be the +same factor anyway. + +And then we'll have, we'll +just explicitly write the + +degeneracy in there. + +So, we can write the partition +function as a + +sum over energy level. + +So, in other words q is the +sum over i, e to the + +minus Ei over kT. + +That's individual molecular +states i. + +But we also could write it as +the sum over i, where this now + +is molecular energy levels i. + +And then we need to incorporate +the degeneracy gi + +e to the minus Ei over kT. + +Same thing, of course. + +But again, sometimes much +more convenient to + +write things this way. + +And of course, we can write +the probabilities of the + +occupancies in the +same way, too. + +That is, we could talk about the +Pi in terms of individual + +states. e to the minus Ei over +kT over q, the whole sum. + +Or Pi summing over energy +levels, gi e to the minus Ei + +over kT, divided by q. + +Here, of course, this +is bigger if + +it's degenerate, right? + +It's saying that the probability +of being in this + +energy level is three times the +probability of it being in + +any individual one +of the states. + +But sometimes it's useful +to keep track of + +things in this way. + +What it shows you too is that, +remember when we looked at, + +did I erase it? + +I guess it's gone. + +When we looked at this +probability distribution for + +the occupancies of the levels, +of course, what it says is at + +any temperature, the lowest +level is the most probable. + +For intermediate temperatures. + +For low temperatures, for +high temperatures. + +At high temperature, it might be +only a little more probable + +than the next one over, and the +next one, and so forth. + +But the very lowest state +always has the highest + +probability. + +But the lowest energy doesn't +always have the highest + +probability because +of degeneracies. + +There might be many states +with an energy up here. + +And the probability of any one +of them is only a little lower + +than the probability of +the lowest energy. + +That could be the case here. + +Let's say, the interaction +energy + +isn't enormously strong. + +So there is some energetic +favoring of this state. + +Maybe there are 10% at +room temperature. + +Maybe it turns out there are 10% +more molecules like this + +than in any one of +these states. + +But of course, these three +altogether mean that there are + +many more molecules at +this energy than + +at the lowest energy. + +Now of course we could do the +same thing for the canonical + +partition function. + +Not just the molecular one. + +So in other words, capital Q sum +over i system microstates. + +e to the minus capital +Ei over kT. + +But we could also write it +as a sum over energies. + +Sum over system energies. + +Ei. + +And then we have to include +the degeneracy. + +Capital Omega i e to the +minus Ei over kT. + +Degeneracy of the system +energy Ei. + +Little g here is the +degeneracy of + +molecular energy Ei. + +Now, same form. + +Just an important difference, +though. + +This number, this little gi, is +typically a small number. + +It could be one, it +could be a few. + +This number is usually +astronomical. + +That's basically, that is, +what we calculated here. + +In other words, how many total +system states are there with a + +particular energy. + +Well, in many, many, many +cases the answer is some + +astronomical number. + +So this number might often +be between one and ten. + +This number might be +10 to the 24th. + +It might be 10 to the 24th +to a large power. + +And, of course, that has a big +effect on the way things end + +up working. + +In statistical mechanics +and in thermodynamics. + +A lot of thermodynamics results +are the way they are + +because you have so many +possible states with a + +particular energy. + +That that energy can be strongly +favored just by + +virtue of the number of +states that there are. + +Just the way, in a very small +way, this energy might be + +favored just because there are +more states with it then there + +are states here. + +But again, with the +system, it's not a + +factor of three to one. + +It might be a factor of +10 to the 24th to + +the power of something. + +It might be just enormously +larger than other + +possibilities that'll tend +to put the energy + +at a certain place. + +And just to continue, of course, +the same thing goes + +for the system probabilities. + +Pi, right, which is e to the +minus Ei over kT divided by + +capital Q. If this is a sum over +states, or omega i e to + +the minus Ei over kT over Q, +let's write this over, if now + +we're calculating +the probability + +of an energy level. + +And it's important to make +the distinction. + +Because in many cases, that's +what we care about. + +What's the energy +of the system? + +And we often don't care about +exactly where's that molecule + +and that one, and that one, +and that one, right? + +The individual states that might +be involved that would + +comprise that energy. + +Now, what I want to do is start +deriving thermodynamics. + +Like I promised, we're going +to be able to derive every + +thermodynamic quantity +if we just know + +the partition function. + +So now I just want +to show that that + +might really be true. + +So, the point is that from Q +we're going to get all of our + +thermodynamics. + +And let's start with +the energy. + +Remember u, right? + +That's our system energy. + +It's an average energy. + +It's an average of the energy +that we would get by looking + +at the states that the system +might be occupying. + +So we can write it +as a sum over i. + +Of Pi times Ei. + +In other words, it's going to be +determined by the energy of + +any system state times the +probability that the system is + +in that state. + +Add them all up. + +Well, we know what that is. + +It's the sum i of Ei, e to the +minus Ei over kT divided by Q. + +Now, I'm going to just make +a simple substitution. + +I'm going to use the term beta +to mean one over kT. + +I'm really just using that so I +don't need to use the chain + +rule a billion times and +doing derivatives. + +So I'm going to write this is +sum over i Ei e to the minus + +beta Ei over Q. + +So Q, then, in this term is +just a sum over i e to the + +minus beta Ei. + +So. + +Now I do want to take +some derivatives. + +If I take dQ / d beta, keeping +V and N constant, then I get + +derivative with respect +to beta. + +Sum over i e to the +minus beta Ei. + +So that's going to bring +out Ei, right? + +So it's going to bring out minus +Ei minus the sum over i, + +Ei e to the minus beta Ei. + +That obviously looks +like a handy thing. + +Because that looks +like that term. + +Then, our average energy, +remember, it's one over Q. Sum + +of i, Ei e to the +minus beta Ei. + +So now, it's just minus one +over q, dQ / d beta. + +So that's just the same as +minus d log Q / d beta. + +And now I'm going to +use the chain rule. + +So it's minus d log Q / +dT times dT / d beta. + +All at constant V and N. Now I +can easily get dT / d beta. + +Because d beta / dT is just +minus one over kT squared. + +It's just the derivative of one +over kT with respect to T. + +So finally, my average E, which +is u, is just kT squared + +times d log Q / dT constant +V, N. That's terrific. + +In other words, if I have an +expression for Q, I know the + +partition function, and I +can calculate it at any + +temperature. + +I just need to take log of it, +take its derivative with + +respect to temperature. + +Multiply it by k T squared +and I've got my energy. + +Not very complicated, right? + +So in other words, macroscopic +thermodynamic properties come + +straight out of our microscopic +model of + +statistical mechanics. + +Statistical thermodynamics. + +Now I'm just going to state the +next result, just because + +I want to get there and it'll be +followed up more next time. + +But it's the following. + +You can see, of course, our Q +is a function of V and N and + +T. It's a function of V because +in principle the + +energies that are going +into all this can be + +a function of volume. + +What thermodynamic function +is naturally a + +function of N, V, T? + +Who remembers? + +Gibbs free energy? + +Helmholtz free energy? + +Enthalpy? + +Which one? + +Nobody knows. + +What's a function of N, V, and +T. Or, V and T, is what we + +really formulate it as. + +N was introduced later. + +The Helmholtz free energy. + +Thank you. + +What that suggests is that +actually the simplest and most + +natural connection between Q and +macroscopic thermodynamics + +is to the Helmholtz +free energy. + +And the result that you'll see +derived next time is A is just + +minus kT log of Q. What +a simple result. + +And you'll see the derivations +in your notes. + +You can see it's a couple +of lines, right? + +But of course, if you know A, +and you know E, you know + +everything, right? + +Because S is in there. + +And then other combinations +can give S and G and mu. + +And p. + +And anything else you want. + +So that's the point, is that +all of macroscopic + +thermodynamics follows. + +And you'll see that elaborated +more next time. + +And in addition, a very simple +natural expression for the + +entropy in terms of the states +available follows, that we've + +alluded to before. + +And now you'll see +it played out. + +Right. \ No newline at end of file diff --git a/ycO0Vn_w9Q0.txt b/ycO0Vn_w9Q0.txt new file mode 100644 index 0000000000000000000000000000000000000000..672cff55debef74b6a5b43c4dcd4e680f76a49ab --- /dev/null +++ b/ycO0Vn_w9Q0.txt @@ -0,0 +1,1819 @@ +align:start position:0% + +hi welcome back to recitation + + align:start position:0% +hi welcome back to recitation + + + align:start position:0% +hi welcome back to recitation +in lecture you learned about some new + + align:start position:0% +in lecture you learned about some new + + + align:start position:0% +in lecture you learned about some new +tools for computing certain limits in + + align:start position:0% +tools for computing certain limits in + + + align:start position:0% +tools for computing certain limits in +particular you learned about l'hopital's + + align:start position:0% +particular you learned about l'hopital's + + + align:start position:0% +particular you learned about l'hopital's +rule so now you have the ability to + + align:start position:0% +rule so now you have the ability to + + + align:start position:0% +rule so now you have the ability to +compute easily some limits that before + + align:start position:0% +compute easily some limits that before + + + align:start position:0% +compute easily some limits that before +might have been difficult to do so I + + align:start position:0% +might have been difficult to do so I + + + align:start position:0% +might have been difficult to do so I +have here four examples of limits some + + align:start position:0% +have here four examples of limits some + + + align:start position:0% +have here four examples of limits some +of which or maybe all of which or maybe + + align:start position:0% +of which or maybe all of which or maybe + + + align:start position:0% +of which or maybe all of which or maybe +none of which sure well definitely some + + align:start position:0% +none of which sure well definitely some + + + align:start position:0% +none of which sure well definitely some +of which will be you could use + + align:start position:0% +of which will be you could use + + + align:start position:0% +of which will be you could use +l'hopital's rule on so here they are why + + align:start position:0% +l'hopital's rule on so here they are why + + + align:start position:0% +l'hopital's rule on so here they are why +don't you pause the video take a few + + align:start position:0% +don't you pause the video take a few + + + align:start position:0% +don't you pause the video take a few +minutes to to work them out come back + + align:start position:0% +minutes to to work them out come back + + + align:start position:0% +minutes to to work them out come back +and we can work them out together + + align:start position:0% + + + + align:start position:0% + +welcome back so we have these four + + align:start position:0% +welcome back so we have these four + + + align:start position:0% +welcome back so we have these four +limits here and let's start solving them + + align:start position:0% +limits here and let's start solving them + + + align:start position:0% +limits here and let's start solving them +shall we so I'll just go from the first + + align:start position:0% +shall we so I'll just go from the first + + + align:start position:0% +shall we so I'll just go from the first +one and then I'll I'll you know go + + align:start position:0% +one and then I'll I'll you know go + + + align:start position:0% +one and then I'll I'll you know go +through them in order so limit a is the + + align:start position:0% +through them in order so limit a is the + + + align:start position:0% +through them in order so limit a is the +limit as X goes to 1 of X to the a minus + + align:start position:0% +limit as X goes to 1 of X to the a minus + + + align:start position:0% +limit as X goes to 1 of X to the a minus +1 over X to the B minus 1 if we want to + + align:start position:0% +1 over X to the B minus 1 if we want to + + + align:start position:0% +1 over X to the B minus 1 if we want to +use l'hopital's rule we have to first + + align:start position:0% +use l'hopital's rule we have to first + + + align:start position:0% +use l'hopital's rule we have to first +check that this is a limit of an + + align:start position:0% +check that this is a limit of an + + + align:start position:0% +check that this is a limit of an +appropriate kind of expression so that's + + align:start position:0% +appropriate kind of expression so that's + + + align:start position:0% +appropriate kind of expression so that's +in particular a limit that is a 0 over 0 + + align:start position:0% +in particular a limit that is a 0 over 0 + + + align:start position:0% +in particular a limit that is a 0 over 0 +or infinity over infinity form so an + + align:start position:0% +or infinity over infinity form so an + + + align:start position:0% +or infinity over infinity form so an +indeterminate quotient and as X goes to + + align:start position:0% +indeterminate quotient and as X goes to + + + align:start position:0% +indeterminate quotient and as X goes to +1 we see that X to the a goes to 1 so X + + align:start position:0% +1 we see that X to the a goes to 1 so X + + + align:start position:0% +1 we see that X to the a goes to 1 so X +to the a minus 1 goes to 0 and similarly + + align:start position:0% +to the a minus 1 goes to 0 and similarly + + + align:start position:0% +to the a minus 1 goes to 0 and similarly +X to the B goes to 1 so X to the B minus + + align:start position:0% +X to the B goes to 1 so X to the B minus + + + align:start position:0% +X to the B goes to 1 so X to the B minus +1 goes to 0 so indeed this is a 0 over 0 + + align:start position:0% +1 goes to 0 so indeed this is a 0 over 0 + + + align:start position:0% +1 goes to 0 so indeed this is a 0 over 0 +indeterminate form so we can apply + + align:start position:0% +indeterminate form so we can apply + + + align:start position:0% +indeterminate form so we can apply +l'hopital's rule so we apply l'hopital's + + align:start position:0% +l'hopital's rule so we apply l'hopital's + + + align:start position:0% +l'hopital's rule so we apply l'hopital's +rule and it says that the limit as X + + align:start position:0% +rule and it says that the limit as X + + + align:start position:0% +rule and it says that the limit as X +goes to 1 of X to the a minus 1 over X + + align:start position:0% +goes to 1 of X to the a minus 1 over X + + + align:start position:0% +goes to 1 of X to the a minus 1 over X +to the B minus 1 ok so what do we do + + align:start position:0% +to the B minus 1 ok so what do we do + + + align:start position:0% +to the B minus 1 ok so what do we do +what l'hopital's rule says is we can + + align:start position:0% +what l'hopital's rule says is we can + + + align:start position:0% +what l'hopital's rule says is we can +take the the derivative of the top and + + align:start position:0% +take the the derivative of the top and + + + align:start position:0% +take the the derivative of the top and +the derivative of the bottom and then + + align:start position:0% +the derivative of the bottom and then + + + align:start position:0% +the derivative of the bottom and then +the limit of the the left side side will + + align:start position:0% +the limit of the the left side side will + + + align:start position:0% +the limit of the the left side side will +be equal to the limit of the result + + align:start position:0% +be equal to the limit of the result + + + align:start position:0% +be equal to the limit of the result +provided the the result actually has an + + align:start position:0% +provided the the result actually has an + + + align:start position:0% +provided the the result actually has an +existent limit either a real number or + + align:start position:0% +existent limit either a real number or + + + align:start position:0% +existent limit either a real number or +infinity or minus infinity so in this + + align:start position:0% +infinity or minus infinity so in this + + + align:start position:0% +infinity or minus infinity so in this +case this says that this expression is + + align:start position:0% +case this says that this expression is + + + align:start position:0% +case this says that this expression is +equal to + + align:start position:0% +equal to + + + align:start position:0% +equal to +the limits at the same limit as X goes + + align:start position:0% +the limits at the same limit as X goes + + + align:start position:0% +the limits at the same limit as X goes +to one of okay so the derivative of the + + align:start position:0% +to one of okay so the derivative of the + + + align:start position:0% +to one of okay so the derivative of the +top is a X to the a minus 1 and the + + align:start position:0% +top is a X to the a minus 1 and the + + + align:start position:0% +top is a X to the a minus 1 and the +derivative of the bottom is B X to the B + + align:start position:0% +derivative of the bottom is B X to the B + + + align:start position:0% +derivative of the bottom is B X to the B +minus 1 so l'hopital's rule says that + + align:start position:0% +minus 1 so l'hopital's rule says that + + + align:start position:0% +minus 1 so l'hopital's rule says that +these two limits are equal provided that + + align:start position:0% +these two limits are equal provided that + + + align:start position:0% +these two limits are equal provided that +the second limit exists so what is the + + align:start position:0% +the second limit exists so what is the + + + align:start position:0% +the second limit exists so what is the +second limit well we can okay we can do + + align:start position:0% +second limit well we can okay we can do + + + align:start position:0% +second limit well we can okay we can do +some simplifications here here there + + align:start position:0% +some simplifications here here there + + + align:start position:0% +some simplifications here here there +what there wasn't you know a lot of + + align:start position:0% +what there wasn't you know a lot of + + + align:start position:0% +what there wasn't you know a lot of +obvious simplifying to be done but here + + align:start position:0% +obvious simplifying to be done but here + + + align:start position:0% +obvious simplifying to be done but here +there's an obvious simplification step + + align:start position:0% +there's an obvious simplification step + + + align:start position:0% +there's an obvious simplification step +so this is equal to the limit as X goes + + align:start position:0% +so this is equal to the limit as X goes + + + align:start position:0% +so this is equal to the limit as X goes +to one of so so a over B is just a + + align:start position:0% +to one of so so a over B is just a + + + align:start position:0% +to one of so so a over B is just a +constant and now the powers of X this is + + align:start position:0% +constant and now the powers of X this is + + + align:start position:0% +constant and now the powers of X this is +X to the a minus B but as X goes to one + + align:start position:0% +X to the a minus B but as X goes to one + + + align:start position:0% +X to the a minus B but as X goes to one +X to the a minus B goes to one no matter + + align:start position:0% +X to the a minus B goes to one no matter + + + align:start position:0% +X to the a minus B goes to one no matter +what a and B are so at this point this + + align:start position:0% +what a and B are so at this point this + + + align:start position:0% +what a and B are so at this point this +isn't an indeterminate form anymore this + + align:start position:0% +isn't an indeterminate form anymore this + + + align:start position:0% +isn't an indeterminate form anymore this +is a nice simple limit we can just plug + + align:start position:0% +is a nice simple limit we can just plug + + + align:start position:0% +is a nice simple limit we can just plug +in so this is just equal to a ok so + + align:start position:0% +in so this is just equal to a ok so + + + align:start position:0% +in so this is just equal to a ok so +that's that's part a straightforward + + align:start position:0% +that's that's part a straightforward + + + align:start position:0% +that's that's part a straightforward +application of l'hopital's rule let's go + + align:start position:0% +application of l'hopital's rule let's go + + + align:start position:0% +application of l'hopital's rule let's go +look at Part B so Part B asked us for + + align:start position:0% +look at Part B so Part B asked us for + + + align:start position:0% +look at Part B so Part B asked us for +the limit as X goes to zero of sine 5x + + align:start position:0% +the limit as X goes to zero of sine 5x + + + align:start position:0% +the limit as X goes to zero of sine 5x +over X so I'll put that right here maybe + + align:start position:0% +over X so I'll put that right here maybe + + + align:start position:0% +over X so I'll put that right here maybe +I'll draw a little border so the limit + + align:start position:0% +I'll draw a little border so the limit + + + align:start position:0% +I'll draw a little border so the limit +as X goes to zero of sine of 5x divided + + align:start position:0% +as X goes to zero of sine of 5x divided + + + align:start position:0% +as X goes to zero of sine of 5x divided +by X so again that there's a there's a + + align:start position:0% +by X so again that there's a there's a + + + align:start position:0% +by X so again that there's a there's a +question of you know is this limit do we + + align:start position:0% +question of you know is this limit do we + + + align:start position:0% +question of you know is this limit do we +know what it is already + + align:start position:0% +know what it is already + + + align:start position:0% +know what it is already +and the answer is maybe we do and maybe + + align:start position:0% +and the answer is maybe we do and maybe + + + align:start position:0% +and the answer is maybe we do and maybe +we don't but suppose we don't so in that + + align:start position:0% +we don't but suppose we don't so in that + + + align:start position:0% +we don't but suppose we don't so in that +case can we apply l'hopital's rule + + align:start position:0% +case can we apply l'hopital's rule + + + align:start position:0% +case can we apply l'hopital's rule +well we check and as X goes to zero sine + + align:start position:0% +well we check and as X goes to zero sine + + + align:start position:0% +well we check and as X goes to zero sine +of 5x so as X goes to zero five X goes + + align:start position:0% +of 5x so as X goes to zero five X goes + + + align:start position:0% +of 5x so as X goes to zero five X goes +to zero so sine of 5 X goes to zero and + + align:start position:0% +to zero so sine of 5 X goes to zero and + + + align:start position:0% +to zero so sine of 5 X goes to zero and +X goes to zero so this is another zero + + align:start position:0% +X goes to zero so this is another zero + + + align:start position:0% +X goes to zero so this is another zero +over zero form so we can apply + + align:start position:0% +over zero form so we can apply + + + align:start position:0% +over zero form so we can apply +l'hopital's rule + + align:start position:0% +l'hopital's rule + + + align:start position:0% +l'hopital's rule +so l'hopital's rule says that this is + + align:start position:0% +so l'hopital's rule says that this is + + + align:start position:0% +so l'hopital's rule says that this is +equal to the limit as X goes to zero of + + align:start position:0% +equal to the limit as X goes to zero of + + + align:start position:0% +equal to the limit as X goes to zero of +well we take the derivative of the top + + align:start position:0% +well we take the derivative of the top + + + align:start position:0% +well we take the derivative of the top +and divide by the derivative of the + + align:start position:0% +and divide by the derivative of the + + + align:start position:0% +and divide by the derivative of the +bottom so the derivative of the top is + + align:start position:0% +bottom so the derivative of the top is + + + align:start position:0% +bottom so the derivative of the top is +just five cosine + + align:start position:0% +just five cosine + + + align:start position:0% +just five cosine +five X and the derivative of the bottom + + align:start position:0% +five X and the derivative of the bottom + + + align:start position:0% +five X and the derivative of the bottom +is one so l'hopital's rule says the + + align:start position:0% +is one so l'hopital's rule says the + + + align:start position:0% +is one so l'hopital's rule says the +limit here is equal to the limit here + + align:start position:0% +limit here is equal to the limit here + + + align:start position:0% +limit here is equal to the limit here +provided this limit exists and now as X + + align:start position:0% +provided this limit exists and now as X + + + align:start position:0% +provided this limit exists and now as X +goes to zero well okay five one is + + align:start position:0% +goes to zero well okay five one is + + + align:start position:0% +goes to zero well okay five one is +constant so we're just looking at the + + align:start position:0% +constant so we're just looking at the + + + align:start position:0% +constant so we're just looking at the +limit of cosine 5x here as X goes to 0 + + align:start position:0% +limit of cosine 5x here as X goes to 0 + + + align:start position:0% +limit of cosine 5x here as X goes to 0 +that just approaches five times cosine + + align:start position:0% +that just approaches five times cosine + + + align:start position:0% +that just approaches five times cosine +of 0 which is 1 so this is equal to + + align:start position:0% +of 0 which is 1 so this is equal to + + + align:start position:0% +of 0 which is 1 so this is equal to +sorry the cosine of zero part is 1 so + + align:start position:0% +sorry the cosine of zero part is 1 so + + + align:start position:0% +sorry the cosine of zero part is 1 so +it's 5 times 1 which is 5 now I should + + align:start position:0% +it's 5 times 1 which is 5 now I should + + + align:start position:0% +it's 5 times 1 which is 5 now I should +note that that we didn't actually really + + align:start position:0% +note that that we didn't actually really + + + align:start position:0% +note that that we didn't actually really +need l'hopital's rule for this one one + + align:start position:0% +need l'hopital's rule for this one one + + + align:start position:0% +need l'hopital's rule for this one one +thing you can remember is that this + + align:start position:0% +thing you can remember is that this + + + align:start position:0% +thing you can remember is that this +limit is is is actually the definition + + align:start position:0% +limit is is is actually the definition + + + align:start position:0% +limit is is is actually the definition +of the derivative of sine of five x at x + + align:start position:0% +of the derivative of sine of five x at x + + + align:start position:0% +of the derivative of sine of five x at x +equals zero so what we just did with + + align:start position:0% +equals zero so what we just did with + + + align:start position:0% +equals zero so what we just did with +l'hopital's rule was use the derivative + + align:start position:0% +l'hopital's rule was use the derivative + + + align:start position:0% +l'hopital's rule was use the derivative +to compute the derivative if you like so + + align:start position:0% +to compute the derivative if you like so + + + align:start position:0% +to compute the derivative if you like so +so we use the fact that we already knew + + align:start position:0% +so we use the fact that we already knew + + + align:start position:0% +so we use the fact that we already knew +the derivative in order to compute it we + + align:start position:0% +the derivative in order to compute it we + + + align:start position:0% +the derivative in order to compute it we +could also just say by definition this + + align:start position:0% +could also just say by definition this + + + align:start position:0% +could also just say by definition this +is the derivative of sine 5x at zero + + align:start position:0% +is the derivative of sine 5x at zero + + + align:start position:0% +is the derivative of sine 5x at zero +which is five cosine of 0 which is 1 + + align:start position:0% +which is five cosine of 0 which is 1 + + + align:start position:0% +which is five cosine of 0 which is 1 +which is 5 + + align:start position:0% +which is 5 + + + align:start position:0% +which is 5 +rather okay so that's Part B now Part C + + align:start position:0% +rather okay so that's Part B now Part C + + + align:start position:0% +rather okay so that's Part B now Part C +asks for the limit as X goes to zero of + + align:start position:0% +asks for the limit as X goes to zero of + + + align:start position:0% +asks for the limit as X goes to zero of +x squared minus 6x plus two yes over X + + align:start position:0% +x squared minus 6x plus two yes over X + + + align:start position:0% +x squared minus 6x plus two yes over X +plus one so this limit you can't apply + + align:start position:0% +plus one so this limit you can't apply + + + align:start position:0% +plus one so this limit you can't apply +l'hopital's rule + + align:start position:0% +l'hopital's rule + + + align:start position:0% +l'hopital's rule +why can't you apply l'hopital's rule + + align:start position:0% +why can't you apply l'hopital's rule + + + align:start position:0% +why can't you apply l'hopital's rule +well because it's not an indeterminate + + align:start position:0% +well because it's not an indeterminate + + + align:start position:0% +well because it's not an indeterminate +form this limit is really easy to + + align:start position:0% +form this limit is really easy to + + + align:start position:0% +form this limit is really easy to +compute you can just plug in x equals + + align:start position:0% +compute you can just plug in x equals + + + align:start position:0% +compute you can just plug in x equals +zero here the top is going to 2 and the + + align:start position:0% +zero here the top is going to 2 and the + + + align:start position:0% +zero here the top is going to 2 and the +bottom is going to 1 so the whole limit + + align:start position:0% +bottom is going to 1 so the whole limit + + + align:start position:0% +bottom is going to 1 so the whole limit +is going to 2 divided by 1 which is 2 so + + align:start position:0% +is going to 2 divided by 1 which is 2 so + + + align:start position:0% +is going to 2 divided by 1 which is 2 so +there's there's no you don't not only + + align:start position:0% +there's there's no you don't not only + + + align:start position:0% +there's there's no you don't not only +you don't need l'hopital's rule and also + + align:start position:0% +you don't need l'hopital's rule and also + + + align:start position:0% +you don't need l'hopital's rule and also +you can't apply l'hopital's rule this is + + align:start position:0% +you can't apply l'hopital's rule this is + + + align:start position:0% +you can't apply l'hopital's rule this is +not a forum in which l'hopital's rule + + align:start position:0% +not a forum in which l'hopital's rule + + + align:start position:0% +not a forum in which l'hopital's rule +applies it's not an indeterminate form + + align:start position:0% +applies it's not an indeterminate form + + + align:start position:0% +applies it's not an indeterminate form +okay so but okay but the result is is + + align:start position:0% +okay so but okay but the result is is + + + align:start position:0% +okay so but okay but the result is is +very easy to compute good so that's 2 + + align:start position:0% +very easy to compute good so that's 2 + + + align:start position:0% +very easy to compute good so that's 2 +and we've got our last one now which is + + align:start position:0% +and we've got our last one now which is + + + align:start position:0% +and we've got our last one now which is +d limit + + align:start position:0% +d limit + + + align:start position:0% +d limit +as X goes to infinity of Ln of 1 plus e + + align:start position:0% +as X goes to infinity of Ln of 1 plus e + + + align:start position:0% +as X goes to infinity of Ln of 1 plus e +to the 3x quantity divided by 2x plus 5 + + align:start position:0% +to the 3x quantity divided by 2x plus 5 + + + align:start position:0% +to the 3x quantity divided by 2x plus 5 +okay well is it obvious what this limit + + align:start position:0% +okay well is it obvious what this limit + + + align:start position:0% +okay well is it obvious what this limit +is not not to me so okay so so then we + + align:start position:0% +is not not to me so okay so so then we + + + align:start position:0% +is not not to me so okay so so then we +can check can we apply it so it's it's a + + align:start position:0% +can check can we apply it so it's it's a + + + align:start position:0% +can check can we apply it so it's it's a +quotient so can we apply l'hopital's + + align:start position:0% +quotient so can we apply l'hopital's + + + align:start position:0% +quotient so can we apply l'hopital's +rule well we can apply l'hopital's rule + + align:start position:0% +rule well we can apply l'hopital's rule + + + align:start position:0% +rule well we can apply l'hopital's rule +if it's an indeterminate quotient so + + align:start position:0% +if it's an indeterminate quotient so + + + align:start position:0% +if it's an indeterminate quotient so +what's happening is X so as to infinity + + align:start position:0% +what's happening is X so as to infinity + + + align:start position:0% +what's happening is X so as to infinity +well let's do the bottom first because + + align:start position:0% +well let's do the bottom first because + + + align:start position:0% +well let's do the bottom first because +that's easy as X goes to infinity 2 X + + align:start position:0% +that's easy as X goes to infinity 2 X + + + align:start position:0% +that's easy as X goes to infinity 2 X +plus 5 goes to infinity and ok as X goes + + align:start position:0% +plus 5 goes to infinity and ok as X goes + + + align:start position:0% +plus 5 goes to infinity and ok as X goes +to infinity + + align:start position:0% +to infinity + + + align:start position:0% +to infinity +either the 3 X goes to infinity so 1 + + align:start position:0% +either the 3 X goes to infinity so 1 + + + align:start position:0% +either the 3 X goes to infinity so 1 +plus e to the 3 X goes to infinity so + + align:start position:0% +plus e to the 3 X goes to infinity so + + + align:start position:0% +plus e to the 3 X goes to infinity so +log of 1 plus e to the 3 X goes to + + align:start position:0% +log of 1 plus e to the 3 X goes to + + + align:start position:0% +log of 1 plus e to the 3 X goes to +infinity so this is an infinity over + + align:start position:0% +infinity so this is an infinity over + + + align:start position:0% +infinity so this is an infinity over +infinity form that's an indeterminate + + align:start position:0% +infinity form that's an indeterminate + + + align:start position:0% +infinity form that's an indeterminate +form and indeterminate quotient so we + + align:start position:0% +form and indeterminate quotient so we + + + align:start position:0% +form and indeterminate quotient so we +can apply l'hopital's rule + + align:start position:0% +can apply l'hopital's rule + + + align:start position:0% +can apply l'hopital's rule +so l'hopital's rule says that this is + + align:start position:0% +so l'hopital's rule says that this is + + + align:start position:0% +so l'hopital's rule says that this is +equal to the limit of the quotient of + + align:start position:0% +equal to the limit of the quotient of + + + align:start position:0% +equal to the limit of the quotient of +the ratio of the derivatives provided + + align:start position:0% +the ratio of the derivatives provided + + + align:start position:0% +the ratio of the derivatives provided +that that that limit exists so this is + + align:start position:0% +that that that limit exists so this is + + + align:start position:0% +that that that limit exists so this is +equal to the limit as X goes to infinity + + align:start position:0% +equal to the limit as X goes to infinity + + + align:start position:0% +equal to the limit as X goes to infinity +of ok so we need to look at the ratio of + + align:start position:0% +of ok so we need to look at the ratio of + + + align:start position:0% +of ok so we need to look at the ratio of +the derivatives so the bottom one is + + align:start position:0% +the derivatives so the bottom one is + + + align:start position:0% +the derivatives so the bottom one is +easy that's two for the top one to + + align:start position:0% +easy that's two for the top one to + + + align:start position:0% +easy that's two for the top one to +compute this derivative we need to use + + align:start position:0% +compute this derivative we need to use + + + align:start position:0% +compute this derivative we need to use +the chain rule here so you take the + + align:start position:0% +the chain rule here so you take the + + + align:start position:0% +the chain rule here so you take the +derivative of this and you get well it's + + align:start position:0% +derivative of this and you get well it's + + + align:start position:0% +derivative of this and you get well it's +a log so on the bottom we get 1 plus e + + align:start position:0% +a log so on the bottom we get 1 plus e + + + align:start position:0% +a log so on the bottom we get 1 plus e +to the 3x and then then by the chain + + align:start position:0% +to the 3x and then then by the chain + + + align:start position:0% +to the 3x and then then by the chain +rule up top you get 3 e to the 3x or + + align:start position:0% +rule up top you get 3 e to the 3x or + + + align:start position:0% +rule up top you get 3 e to the 3x or +just rewriting this a little bit in a + + align:start position:0% +just rewriting this a little bit in a + + + align:start position:0% +just rewriting this a little bit in a +nicer form this is the limit as X goes + + align:start position:0% +nicer form this is the limit as X goes + + + align:start position:0% +nicer form this is the limit as X goes +to infinity of 3 over 2 times e to the + + align:start position:0% +to infinity of 3 over 2 times e to the + + + align:start position:0% +to infinity of 3 over 2 times e to the +3x over 1 plus e to the 3x all right so + + align:start position:0% +3x over 1 plus e to the 3x all right so + + + align:start position:0% +3x over 1 plus e to the 3x all right so +now the question is what do we do from + + align:start position:0% +now the question is what do we do from + + + align:start position:0% +now the question is what do we do from +here well is this limit obvious well ok + + align:start position:0% +here well is this limit obvious well ok + + + align:start position:0% +here well is this limit obvious well ok +so there are + + align:start position:0% +so there are + + + align:start position:0% +so there are +you know to two situations here one is + + align:start position:0% +you know to two situations here one is + + + align:start position:0% +you know to two situations here one is +you you might look at this and you might + + align:start position:0% +you you might look at this and you might + + + align:start position:0% +you you might look at this and you might +already know what this limit is and the + + align:start position:0% +already know what this limit is and the + + + align:start position:0% +already know what this limit is and the +reason you might know that is that X + + align:start position:0% +reason you might know that is that X + + + align:start position:0% +reason you might know that is that X +goes to infinity e to the 3x is going to + + align:start position:0% +goes to infinity e to the 3x is going to + + + align:start position:0% +goes to infinity e to the 3x is going to +infinity and e to the 3x and 1 plus e to + + align:start position:0% +infinity and e to the 3x and 1 plus e to + + + align:start position:0% +infinity and e to the 3x and 1 plus e to +the 3x is going to infinity so this is + + align:start position:0% +the 3x is going to infinity so this is + + + align:start position:0% +the 3x is going to infinity so this is +an infinity over infinity indeterminate + + align:start position:0% +an infinity over infinity indeterminate + + + align:start position:0% +an infinity over infinity indeterminate +form and so you could apply l'hopital's + + align:start position:0% +form and so you could apply l'hopital's + + + align:start position:0% +form and so you could apply l'hopital's +rule to it again okay that that that's + + align:start position:0% +rule to it again okay that that that's + + + align:start position:0% +rule to it again okay that that that's +one thing you could do but you might + + align:start position:0% +one thing you could do but you might + + + align:start position:0% +one thing you could do but you might +also look at it and say well these two + + align:start position:0% +also look at it and say well these two + + + align:start position:0% +also look at it and say well these two +things are going to infinity at exactly + + align:start position:0% +things are going to infinity at exactly + + + align:start position:0% +things are going to infinity at exactly +the same rate right this plus one is is + + align:start position:0% +the same rate right this plus one is is + + + align:start position:0% +the same rate right this plus one is is +almost totally irrelevant I mean + + align:start position:0% +almost totally irrelevant I mean + + + align:start position:0% +almost totally irrelevant I mean +actually for purposes of estimating the + + align:start position:0% +actually for purposes of estimating the + + + align:start position:0% +actually for purposes of estimating the +magnitude of this fraction it is totally + + align:start position:0% +magnitude of this fraction it is totally + + + align:start position:0% +magnitude of this fraction it is totally +irrelevant when you take you know when + + align:start position:0% +irrelevant when you take you know when + + + align:start position:0% +irrelevant when you take you know when +3x is big then say e to the 3x is like a + + align:start position:0% +3x is big then say e to the 3x is like a + + + align:start position:0% +3x is big then say e to the 3x is like a +billion or something so e to the 3x is a + + align:start position:0% +billion or something so e to the 3x is a + + + align:start position:0% +billion or something so e to the 3x is a +billion so you have a billion over a + + align:start position:0% +billion so you have a billion over a + + + align:start position:0% +billion so you have a billion over a +billion and one right so it's very very + + align:start position:0% +billion and one right so it's very very + + + align:start position:0% +billion and one right so it's very very +very close to one and it's gonna closer + + align:start position:0% +very close to one and it's gonna closer + + + align:start position:0% +very close to one and it's gonna closer +and closer to one to one so okay so if + + align:start position:0% +and closer to one to one so okay so if + + + align:start position:0% +and closer to one to one so okay so if +you if you didn't trust that analysis + + align:start position:0% +you if you didn't trust that analysis + + + align:start position:0% +you if you didn't trust that analysis +based on magnitudes I mean the idea here + + align:start position:0% +based on magnitudes I mean the idea here + + + align:start position:0% +based on magnitudes I mean the idea here +is just that the most significant term + + align:start position:0% +is just that the most significant term + + + align:start position:0% +is just that the most significant term +and the top is the e to the 3x the most + + align:start position:0% +and the top is the e to the 3x the most + + + align:start position:0% +and the top is the e to the 3x the most +significant term in the bottom is e to + + align:start position:0% +significant term in the bottom is e to + + + align:start position:0% +significant term in the bottom is e to +the 3x they dominate everything else + + align:start position:0% +the 3x they dominate everything else + + + align:start position:0% +the 3x they dominate everything else +that appears which is just this little + + align:start position:0% +that appears which is just this little + + + align:start position:0% +that appears which is just this little +one so that's gonna give you a ratio of + + align:start position:0% +one so that's gonna give you a ratio of + + + align:start position:0% +one so that's gonna give you a ratio of +1 if you don't trust that analysis you + + align:start position:0% +1 if you don't trust that analysis you + + + align:start position:0% +1 if you don't trust that analysis you +can apply l'hopital's rule again and + + align:start position:0% +can apply l'hopital's rule again and + + + align:start position:0% +can apply l'hopital's rule again and +l'hopital's rule will tell you exactly + + align:start position:0% +l'hopital's rule will tell you exactly + + + align:start position:0% +l'hopital's rule will tell you exactly +the equivalent thing when you take a + + align:start position:0% +the equivalent thing when you take a + + + align:start position:0% +the equivalent thing when you take a +derivative you'll be left with 3 e to + + align:start position:0% +derivative you'll be left with 3 e to + + + align:start position:0% +derivative you'll be left with 3 e to +the 3x over 3 e to the 3x which is just + + align:start position:0% +the 3x over 3 e to the 3x which is just + + + align:start position:0% +the 3x over 3 e to the 3x which is just +1 so in either case this part goes to 1 + + align:start position:0% +1 so in either case this part goes to 1 + + + align:start position:0% +1 so in either case this part goes to 1 +so 3 halves times it goes right to 3 + + align:start position:0% +so 3 halves times it goes right to 3 + + + align:start position:0% +so 3 halves times it goes right to 3 +halves alright so there you have it four + + align:start position:0% +halves alright so there you have it four + + + align:start position:0% +halves alright so there you have it four +limits computed with l'hopital's rule + + align:start position:0% +limits computed with l'hopital's rule + + + align:start position:0% +limits computed with l'hopital's rule +well one of them computed without + + align:start position:0% +well one of them computed without + + + align:start position:0% +well one of them computed without +l'hopital's rule remember you always + + align:start position:0% +l'hopital's rule remember you always + + + align:start position:0% +l'hopital's rule remember you always +have to check that you actually have an + + align:start position:0% +have to check that you actually have an + + + align:start position:0% +have to check that you actually have an +indeterminate form before you apply + + align:start position:0% +indeterminate form before you apply + + + align:start position:0% +indeterminate form before you apply +l'hopital's rule and that's all i have + + align:start position:0% +l'hopital's rule and that's all i have + + + align:start position:0% +l'hopital's rule and that's all i have +to say about that so I'll end there \ No newline at end of file diff --git a/zNCBDrnT05E.txt b/zNCBDrnT05E.txt new file mode 100644 index 0000000000000000000000000000000000000000..64b573b734eed491fa170dbcbce80161ea577e83 --- /dev/null +++ b/zNCBDrnT05E.txt @@ -0,0 +1,11187 @@ +align:start position:0% + +The following content is provided under + + align:start position:0% +The following content is provided under + + + align:start position:0% +The following content is provided under +a Creative Common license. Your support + + align:start position:0% +a Creative Common license. Your support + + + align:start position:0% +a Creative Common license. Your support +will help MIT Open Courseware continue + + align:start position:0% +will help MIT Open Courseware continue + + + align:start position:0% +will help MIT Open Courseware continue +to offer highquality educational + + align:start position:0% +to offer highquality educational + + + align:start position:0% +to offer highquality educational +resources for free. To make a donation + + align:start position:0% +resources for free. To make a donation + + + align:start position:0% +resources for free. To make a donation +or to view additional materials from + + align:start position:0% +or to view additional materials from + + + align:start position:0% +or to view additional materials from +hundreds of MIT courses, visit MIT Open + + align:start position:0% +hundreds of MIT courses, visit MIT Open + + + align:start position:0% +hundreds of MIT courses, visit MIT Open +Courseware at ocw.mmit.edu. + + align:start position:0% + + + + align:start position:0% + +The there's a reading the the new + + align:start position:0% +The there's a reading the the new + + + align:start position:0% +The there's a reading the the new +reading is on stellar. It's an excerpt + + align:start position:0% +reading is on stellar. It's an excerpt + + + align:start position:0% +reading is on stellar. It's an excerpt +from a textbook on dynamics by professor + + align:start position:0% +from a textbook on dynamics by professor + + + align:start position:0% +from a textbook on dynamics by professor +Jim Williams who recently who was in uh + + align:start position:0% +Jim Williams who recently who was in uh + + + align:start position:0% +Jim Williams who recently who was in uh +in the mechanical engineering department + + align:start position:0% +in the mechanical engineering department + + + align:start position:0% +in the mechanical engineering department +here at MIT and just recently retired. + + align:start position:0% +here at MIT and just recently retired. + + + align:start position:0% +here at MIT and just recently retired. +This reading is essentially a review of + + align:start position:0% +This reading is essentially a review of + + + align:start position:0% +This reading is essentially a review of +everything we've done in kinematics. So + + align:start position:0% +everything we've done in kinematics. So + + + align:start position:0% +everything we've done in kinematics. So +it gives you a different point of view. + + align:start position:0% +it gives you a different point of view. + + + align:start position:0% +it gives you a different point of view. +It's extremely well written. it. So it + + align:start position:0% +It's extremely well written. it. So it + + + align:start position:0% +It's extremely well written. it. So it +goes through things like derivatives of + + align:start position:0% +goes through things like derivatives of + + + align:start position:0% +goes through things like derivatives of +rotating vectors. It has three or four + + align:start position:0% +rotating vectors. It has three or four + + + align:start position:0% +rotating vectors. It has three or four +really terrific examples of problems + + align:start position:0% +really terrific examples of problems + + + align:start position:0% +really terrific examples of problems +that uh are solved using the techniques + + align:start position:0% +that uh are solved using the techniques + + + align:start position:0% +that uh are solved using the techniques +that we've used up to this point. So + + align:start position:0% +that we've used up to this point. So + + + align:start position:0% +that we've used up to this point. So +it's a good way to re review for the + + align:start position:0% +it's a good way to re review for the + + + align:start position:0% +it's a good way to re review for the +quiz which is coming up a week from + + align:start position:0% +quiz which is coming up a week from + + + align:start position:0% +quiz which is coming up a week from +Thursday on October 14th. That quiz will + + align:start position:0% +Thursday on October 14th. That quiz will + + + align:start position:0% +Thursday on October 14th. That quiz will +be here. + + align:start position:0% +be here. + + + align:start position:0% +be here. +closed book, one sheet of notes, piece + + align:start position:0% +closed book, one sheet of notes, piece + + + align:start position:0% +closed book, one sheet of notes, piece +of paper, both sides as your for + + align:start position:0% +of paper, both sides as your for + + + align:start position:0% +of paper, both sides as your for +reference material. + + align:start position:0% +reference material. + + + align:start position:0% +reference material. +Okay, survey results. So, you have pet + + align:start position:0% +Okay, survey results. So, you have pet + + + align:start position:0% +Okay, survey results. So, you have pet +set 4. It has uh I think five questions + + align:start position:0% +set 4. It has uh I think five questions + + + align:start position:0% +set 4. It has uh I think five questions +on it. We'll quickly take a look at the + + align:start position:0% +on it. We'll quickly take a look at the + + + align:start position:0% +on it. We'll quickly take a look at the +at the problems that you're working on + + align:start position:0% +at the problems that you're working on + + + align:start position:0% +at the problems that you're working on +right now. So, here's this uh yo-yo like + + align:start position:0% +right now. So, here's this uh yo-yo like + + + align:start position:0% +right now. So, here's this uh yo-yo like +thing, a spool. It's all There were some + + align:start position:0% +thing, a spool. It's all There were some + + + align:start position:0% +thing, a spool. It's all There were some +questions on NB. The inner piece doesn't + + align:start position:0% +questions on NB. The inner piece doesn't + + + align:start position:0% +questions on NB. The inner piece doesn't +rotate relative to the outer piece. It's + + align:start position:0% +rotate relative to the outer piece. It's + + + align:start position:0% +rotate relative to the outer piece. It's +all one solid spool, but it has two + + align:start position:0% +all one solid spool, but it has two + + + align:start position:0% +all one solid spool, but it has two +different radi that uh uh are in + + align:start position:0% +different radi that uh uh are in + + + align:start position:0% +different radi that uh uh are in +functioning in the problem. And the + + align:start position:0% +functioning in the problem. And the + + + align:start position:0% +functioning in the problem. And the +question is, will the spool roll to the + + align:start position:0% +question is, will the spool roll to the + + + align:start position:0% +question is, will the spool roll to the +left or to the right when the string is + + align:start position:0% +left or to the right when the string is + + + align:start position:0% +left or to the right when the string is +pulled to the right? So, we're going to + + align:start position:0% +pulled to the right? So, we're going to + + + align:start position:0% +pulled to the right? So, we're going to +come back to it. I'm just going to run + + align:start position:0% +come back to it. I'm just going to run + + + align:start position:0% +come back to it. I'm just going to run +through all the questions quickly. The + + align:start position:0% +through all the questions quickly. The + + + align:start position:0% +through all the questions quickly. The +second one was this somewhat familiar + + align:start position:0% +second one was this somewhat familiar + + + align:start position:0% +second one was this somewhat familiar +problem you've done uh done. Now the uh + + align:start position:0% +problem you've done uh done. Now the uh + + + align:start position:0% +problem you've done uh done. Now the uh +the question asks you about + + align:start position:0% +the question asks you about + + + align:start position:0% +the question asks you about +how fast it will be it has to go before + + align:start position:0% +how fast it will be it has to go before + + + align:start position:0% +how fast it will be it has to go before +the thing starts sliding up and this the + + align:start position:0% +the thing starts sliding up and this the + + + align:start position:0% +the thing starts sliding up and this the +survey question if the starting position + + align:start position:0% +survey question if the starting position + + + align:start position:0% +survey question if the starting position +of the spool is moved down the rod + + align:start position:0% +of the spool is moved down the rod + + + align:start position:0% +of the spool is moved down the rod +will the angular rate be higher when the + + align:start position:0% +will the angular rate be higher when the + + + align:start position:0% +will the angular rate be higher when the +spool begins to slide up the rod you + + align:start position:0% +spool begins to slide up the rod you + + + align:start position:0% +spool begins to slide up the rod you +have to go faster to get it to go okay + + align:start position:0% +have to go faster to get it to go okay + + + align:start position:0% +have to go faster to get it to go okay +next + + align:start position:0% +next + + + align:start position:0% +next +okay this is finding the equation of + + align:start position:0% +okay this is finding the equation of + + + align:start position:0% +okay this is finding the equation of +motion for a pendulum and everybody + + align:start position:0% +motion for a pendulum and everybody + + + align:start position:0% +motion for a pendulum and everybody +knows the natural frequency of a + + align:start position:0% +knows the natural frequency of a + + + align:start position:0% +knows the natural frequency of a +pendulum square root of G over L but + + align:start position:0% +pendulum square root of G over L but + + + align:start position:0% +pendulum square root of G over L but +this pendulum has a torsional spring + + align:start position:0% +this pendulum has a torsional spring + + + align:start position:0% +this pendulum has a torsional spring +added to it and the question is square + + align:start position:0% +added to it and the question is square + + + align:start position:0% +added to it and the question is square +root G over L doesn't involve the mass + + align:start position:0% +root G over L doesn't involve the mass + + + align:start position:0% +root G over L doesn't involve the mass +but will the natural frequency now that + + align:start position:0% +but will the natural frequency now that + + + align:start position:0% +but will the natural frequency now that +you put the torsional spring on it will + + align:start position:0% +you put the torsional spring on it will + + + align:start position:0% +you put the torsional spring on it will +it will it now involve the mass no + + align:start position:0% +it will it now involve the mass no + + + align:start position:0% +it will it now involve the mass no +reason you should know this you've + + align:start position:0% +reason you should know this you've + + + align:start position:0% +reason you should know this you've +probably never done this problem before + + align:start position:0% +probably never done this problem before + + + align:start position:0% +probably never done this problem before +and uh we'll come back to that next + + align:start position:0% +and uh we'll come back to that next + + + align:start position:0% +and uh we'll come back to that next +the fourth problem two degree freedom + + align:start position:0% +the fourth problem two degree freedom + + + align:start position:0% +the fourth problem two degree freedom +system and want you to uh come up with + + align:start position:0% +system and want you to uh come up with + + + align:start position:0% +system and want you to uh come up with +the equations of motion. But the survey + + align:start position:0% +the equations of motion. But the survey + + + align:start position:0% +the equations of motion. But the survey +question, if K1 didn't exist, this is + + align:start position:0% +question, if K1 didn't exist, this is + + + align:start position:0% +question, if K1 didn't exist, this is +just two masses coupled by a spring. + + align:start position:0% +just two masses coupled by a spring. + + + align:start position:0% +just two masses coupled by a spring. +It's no, this thing is no longer + + align:start position:0% +It's no, this thing is no longer + + + align:start position:0% +It's no, this thing is no longer +constrained in the X direction. There's + + align:start position:0% +constrained in the X direction. There's + + + align:start position:0% +constrained in the X direction. There's +no X constraints on the system. + + align:start position:0% +no X constraints on the system. + + + align:start position:0% +no X constraints on the system. +So if that if that's the case, this + + align:start position:0% +So if that if that's the case, this + + + align:start position:0% +So if that if that's the case, this +system still has two natural + + align:start position:0% +system still has two natural + + + align:start position:0% +system still has two natural +frequencies. + + align:start position:0% +frequencies. + + + align:start position:0% +frequencies. +An object that can a system that can + + align:start position:0% +An object that can a system that can + + + align:start position:0% +An object that can a system that can +vibrate essentially has as many natural + + align:start position:0% +vibrate essentially has as many natural + + + align:start position:0% +vibrate essentially has as many natural +frequencies as it does equations of + + align:start position:0% +frequencies as it does equations of + + + align:start position:0% +frequencies as it does equations of +motion. This one requires two equations + + align:start position:0% +motion. This one requires two equations + + + align:start position:0% +motion. This one requires two equations +of motion, but it will have one zero + + align:start position:0% +of motion, but it will have one zero + + + align:start position:0% +of motion, but it will have one zero +natural frequency and the other one + + align:start position:0% +natural frequency and the other one + + + align:start position:0% +natural frequency and the other one +greater than zero. In the second case, + + align:start position:0% +greater than zero. In the second case, + + + align:start position:0% +greater than zero. In the second case, +when it's greater than zero, + + align:start position:0% +when it's greater than zero, + + + align:start position:0% +when it's greater than zero, +this thing is oscillating somehow. It + + align:start position:0% +this thing is oscillating somehow. It + + + align:start position:0% +this thing is oscillating somehow. It +has no extra strength. What can you say + + align:start position:0% +has no extra strength. What can you say + + + align:start position:0% +has no extra strength. What can you say +about the position of the center of + + align:start position:0% +about the position of the center of + + + align:start position:0% +about the position of the center of +mass? + + align:start position:0% +mass? + + + align:start position:0% +mass? +So, let's look at the results. So this + + align:start position:0% +So, let's look at the results. So this + + + align:start position:0% +So, let's look at the results. So this +is the first one is the spool problem. + + align:start position:0% +is the first one is the spool problem. + + + align:start position:0% +is the first one is the spool problem. +So + + align:start position:0% +So + + + align:start position:0% +So +let's + + align:start position:0% + + + + align:start position:0% + +here's the spool. + + align:start position:0% +here's the spool. + + + align:start position:0% +here's the spool. +Here's the table. Here's the inner + + align:start position:0% +Here's the table. Here's the inner + + + align:start position:0% +Here's the table. Here's the inner +radius. It's got a string wrapped on it. + + align:start position:0% +radius. It's got a string wrapped on it. + + + align:start position:0% +radius. It's got a string wrapped on it. +You're pulling the string this way at V + + align:start position:0% +You're pulling the string this way at V + + + align:start position:0% +You're pulling the string this way at V +in the I direction. This will be + + align:start position:0% + + + + align:start position:0% + +O + + align:start position:0% +O + + + align:start position:0% +O +XY. + + align:start position:0% +XY. + + + align:start position:0% +XY. +And now the question is when you pull on + + align:start position:0% +And now the question is when you pull on + + + align:start position:0% +And now the question is when you pull on +this, which way will the spool go? And + + align:start position:0% +this, which way will the spool go? And + + + align:start position:0% +this, which way will the spool go? And +most of you said it'll go to the left. + + align:start position:0% +most of you said it'll go to the left. + + + align:start position:0% +most of you said it'll go to the left. +So I made this I made this up. We're + + align:start position:0% +So I made this I made this up. We're + + + align:start position:0% +So I made this I made this up. We're +going to do the experiment. + + align:start position:0% + + + + align:start position:0% + +So, I've wrapped Teflon tape on this + + align:start position:0% +So, I've wrapped Teflon tape on this + + + align:start position:0% +So, I've wrapped Teflon tape on this +spool. + + align:start position:0% +spool. + + + align:start position:0% +spool. +It's got a C battery in the center to + + align:start position:0% +It's got a C battery in the center to + + + align:start position:0% +It's got a C battery in the center to +give it a little bit of weight. + + align:start position:0% +give it a little bit of weight. + + + align:start position:0% +give it a little bit of weight. +And here's the experiment. + + align:start position:0% +And here's the experiment. + + + align:start position:0% +And here's the experiment. +And the guys in the booth, I hope, have + + align:start position:0% +And the guys in the booth, I hope, have + + + align:start position:0% +And the guys in the booth, I hope, have +a minute to be to zoom in on it. I'm + + align:start position:0% +a minute to be to zoom in on it. I'm + + + align:start position:0% +a minute to be to zoom in on it. I'm +going to let go. And now I'm going to + + align:start position:0% +going to let go. And now I'm going to + + + align:start position:0% +going to let go. And now I'm going to +start pulling. Whoops. I need to put a + + align:start position:0% +start pulling. Whoops. I need to put a + + + align:start position:0% +start pulling. Whoops. I need to put a +little more out here. + + align:start position:0% +little more out here. + + + align:start position:0% +little more out here. +Pull on the tape. + + align:start position:0% + + + + align:start position:0% + +You believe it? + + align:start position:0% +You believe it? + + + align:start position:0% +You believe it? +So, I've done the reverse of what's say + + align:start position:0% +So, I've done the reverse of what's say + + + align:start position:0% +So, I've done the reverse of what's say +there. I'm pulling that way, but it goes + + align:start position:0% +there. I'm pulling that way, but it goes + + + align:start position:0% +there. I'm pulling that way, but it goes +in the same direction as you pull it. + + align:start position:0% +in the same direction as you pull it. + + + align:start position:0% +in the same direction as you pull it. +So, the answer to this question is it + + align:start position:0% +So, the answer to this question is it + + + align:start position:0% +So, the answer to this question is it +would go to the right. + + align:start position:0% +would go to the right. + + + align:start position:0% +would go to the right. +Kind of unbelievable almost, right? Huh? + + align:start position:0% +Kind of unbelievable almost, right? Huh? + + + align:start position:0% +Kind of unbelievable almost, right? Huh? +How does it do that? + + align:start position:0% +How does it do that? + + + align:start position:0% +How does it do that? +Let's do it again. + + align:start position:0% + + + + align:start position:0% + +All right. Now, show you something else. + + align:start position:0% +All right. Now, show you something else. + + + align:start position:0% +All right. Now, show you something else. +If you that hasn't sort of boggled your + + align:start position:0% +If you that hasn't sort of boggled your + + + align:start position:0% +If you that hasn't sort of boggled your +mind, + + align:start position:0% +mind, + + + align:start position:0% +mind, +then what's it going to do if I pull + + align:start position:0% +then what's it going to do if I pull + + + align:start position:0% +then what's it going to do if I pull +straight up? + + align:start position:0% +straight up? + + + align:start position:0% +straight up? +How many think it's going to go that + + align:start position:0% +How many think it's going to go that + + + align:start position:0% +How many think it's going to go that +way? Raise your hand. + + align:start position:0% +way? Raise your hand. + + + align:start position:0% +way? Raise your hand. +How many think it's going to go that + + align:start position:0% +How many think it's going to go that + + + align:start position:0% +How many think it's going to go that +way? Raise your hand. All right, + + align:start position:0% +way? Raise your hand. All right, + + + align:start position:0% +way? Raise your hand. All right, +sure enough. Now, that means it must be + + align:start position:0% +sure enough. Now, that means it must be + + + align:start position:0% +sure enough. Now, that means it must be +some angle in between in which it will + + align:start position:0% +some angle in between in which it will + + + align:start position:0% +some angle in between in which it will +do neither. It'll start to slip. + + align:start position:0% + + + + align:start position:0% + +Right about there. + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +Neat little problem. + + align:start position:0% + + + + align:start position:0% + +And now this you know doing this problem + + align:start position:0% +And now this you know doing this problem + + + align:start position:0% +And now this you know doing this problem +is all about + + align:start position:0% +is all about + + + align:start position:0% +is all about +computing velocities + + align:start position:0% +computing velocities + + + align:start position:0% +computing velocities +using concepts like + + align:start position:0% + + + + align:start position:0% + +so if we call this a + + align:start position:0% +so if we call this a + + + align:start position:0% +so if we call this a +b c I think it's the other way around in + + align:start position:0% +b c I think it's the other way around in + + + align:start position:0% +b c I think it's the other way around in +the in the problem excuse me a b + + align:start position:0% +the in the problem excuse me a b + + + align:start position:0% +the in the problem excuse me a b +c and E + + align:start position:0% + + + + align:start position:0% + +the key to this problem is being able to + + align:start position:0% +the key to this problem is being able to + + + align:start position:0% +the key to this problem is being able to +figure out what the velocity of this + + align:start position:0% +figure out what the velocity of this + + + align:start position:0% +figure out what the velocity of this +point C is. + + align:start position:0% +point C is. + + + align:start position:0% +point C is. +And the first thing to understand this + + align:start position:0% +And the first thing to understand this + + + align:start position:0% +And the first thing to understand this +is the velocity of the end of the tape + + align:start position:0% +is the velocity of the end of the tape + + + align:start position:0% +is the velocity of the end of the tape +in + + align:start position:0% +in + + + align:start position:0% +in +a + + align:start position:0% +a + + + align:start position:0% +a +an in a fixed reference frame. + + align:start position:0% +an in a fixed reference frame. + + + align:start position:0% +an in a fixed reference frame. +So every point on the tape moves at the + + align:start position:0% +So every point on the tape moves at the + + + align:start position:0% +So every point on the tape moves at the +same speed. That means where it touches + + align:start position:0% +same speed. That means where it touches + + + align:start position:0% +same speed. That means where it touches +right here is also moving at that speed. + + align:start position:0% +right here is also moving at that speed. + + + align:start position:0% +right here is also moving at that speed. +So the velocity + + align:start position:0% +So the velocity + + + align:start position:0% +So the velocity +of C with respect to O is V I. And + + align:start position:0% +of C with respect to O is V I. And + + + align:start position:0% +of C with respect to O is V I. And +that's kind of the key to the problem. + + align:start position:0% +that's kind of the key to the problem. + + + align:start position:0% +that's kind of the key to the problem. +So + + align:start position:0% +So + + + align:start position:0% +So +if that's also equal to the velocity of + + align:start position:0% +if that's also equal to the velocity of + + + align:start position:0% +if that's also equal to the velocity of +D with respect to O plus the velocity of + + align:start position:0% +D with respect to O plus the velocity of + + + align:start position:0% +D with respect to O plus the velocity of +C with respect to D + + align:start position:0% +C with respect to D + + + align:start position:0% +C with respect to D +and + + align:start position:0% +and + + + align:start position:0% +and +the velocity of D is this point of + + align:start position:0% +the velocity of D is this point of + + + align:start position:0% +the velocity of D is this point of +contact with the ground. What's that + + align:start position:0% +contact with the ground. What's that + + + align:start position:0% +contact with the ground. What's that +velocity? + + align:start position:0% +velocity? + + + align:start position:0% +velocity? +Zero. This is back to those + + align:start position:0% +Zero. This is back to those + + + align:start position:0% +Zero. This is back to those +instantaneous center of rotation things. + + align:start position:0% +instantaneous center of rotation things. + + + align:start position:0% +instantaneous center of rotation things. +zero there is what makes this equation + + align:start position:0% +zero there is what makes this equation + + + align:start position:0% +zero there is what makes this equation +easy. + + align:start position:0% +easy. + + + align:start position:0% +easy. +And then you have an you know how to + + align:start position:0% +And then you have an you know how to + + + align:start position:0% +And then you have an you know how to +compute the velocity of a rotating + + align:start position:0% +compute the velocity of a rotating + + + align:start position:0% +compute the velocity of a rotating +vector. This one's not changing length, + + align:start position:0% +vector. This one's not changing length, + + + align:start position:0% +vector. This one's not changing length, +but it is surely rotating about this + + align:start position:0% +but it is surely rotating about this + + + align:start position:0% +but it is surely rotating about this +point. And so there's going to be an + + align:start position:0% +point. And so there's going to be an + + + align:start position:0% +point. And so there's going to be an +omega cross r in here. And that'll allow + + align:start position:0% +omega cross r in here. And that'll allow + + + align:start position:0% +omega cross r in here. And that'll allow +you to solve for omega. And then once + + align:start position:0% +you to solve for omega. And then once + + + align:start position:0% +you to solve for omega. And then once +you know for omega, then you can solve + + align:start position:0% +you know for omega, then you can solve + + + align:start position:0% +you know for omega, then you can solve +for a, which is the real question that + + align:start position:0% +for a, which is the real question that + + + align:start position:0% +for a, which is the real question that +was asked. Okay, + + align:start position:0% +was asked. Okay, + + + align:start position:0% +was asked. Okay, +next one. + + align:start position:0% +next one. + + + align:start position:0% +next one. +This is + + align:start position:0% +This is + + + align:start position:0% +This is +the uh Oh yeah. So the starting position + + align:start position:0% +the uh Oh yeah. So the starting position + + + align:start position:0% +the uh Oh yeah. So the starting position +this is a spool. + + align:start position:0% + + + + align:start position:0% + +Here's the arm + + align:start position:0% +Here's the arm + + + align:start position:0% +Here's the arm +and here is that it's the question is at + + align:start position:0% +and here is that it's the question is at + + + align:start position:0% +and here is that it's the question is at +0.25 m up here. And if you move it down + + align:start position:0% +0.25 m up here. And if you move it down + + + align:start position:0% +0.25 m up here. And if you move it down +to 0.15, + + align:start position:0% + + + + align:start position:0% + +will the system be able to go faster + + align:start position:0% +will the system be able to go faster + + + align:start position:0% +will the system be able to go faster +before it breaks loose or not? And your + + align:start position:0% +before it breaks loose or not? And your + + + align:start position:0% +before it breaks loose or not? And your +answer was most people said yes. And + + align:start position:0% +answer was most people said yes. And + + + align:start position:0% +answer was most people said yes. And +that basically that's true. + + align:start position:0% +that basically that's true. + + + align:start position:0% +that basically that's true. +What is it that's driving that thing + + align:start position:0% +What is it that's driving that thing + + + align:start position:0% +What is it that's driving that thing +providing the uh force that is trying to + + align:start position:0% +providing the uh force that is trying to + + + align:start position:0% +providing the uh force that is trying to +push it up the sleeve? + + align:start position:0% + + + + align:start position:0% + +So the the rod is as it going around is + + align:start position:0% +So the the rod is as it going around is + + + align:start position:0% +So the the rod is as it going around is +trying to drive that thing in a circle + + align:start position:0% +trying to drive that thing in a circle + + + align:start position:0% +trying to drive that thing in a circle +and therefore it is being accelerated + + align:start position:0% +and therefore it is being accelerated + + + align:start position:0% +and therefore it is being accelerated +in in this to the central point. So it + + align:start position:0% +in in this to the central point. So it + + + align:start position:0% +in in this to the central point. So it +has centripal acceleration and that + + align:start position:0% +has centripal acceleration and that + + + align:start position:0% +has centripal acceleration and that +requires forces and they come through + + align:start position:0% +requires forces and they come through + + + align:start position:0% +requires forces and they come through +the rod and that will develop normal + + align:start position:0% +the rod and that will develop normal + + + align:start position:0% +the rod and that will develop normal +forces and friction. So when you + + align:start position:0% +forces and friction. So when you + + + align:start position:0% +forces and friction. So when you +when you slide down the rod some to that + + align:start position:0% +when you slide down the rod some to that + + + align:start position:0% +when you slide down the rod some to that +new position is has that centrial + + align:start position:0% +new position is has that centrial + + + align:start position:0% +new position is has that centrial +acceleration gone up or down? + + align:start position:0% + + + + align:start position:0% + +R has gotten smaller. Centripal + + align:start position:0% +R has gotten smaller. Centripal + + + align:start position:0% +R has gotten smaller. Centripal +acceleration is + + align:start position:0% +acceleration is + + + align:start position:0% +acceleration is +r omega squared. Right? So you you might + + align:start position:0% +r omega squared. Right? So you you might + + + align:start position:0% +r omega squared. Right? So you you might +be speaking algebraically that so the + + align:start position:0% +be speaking algebraically that so the + + + align:start position:0% +be speaking algebraically that so the +magnitude of that centripal acceleration + + align:start position:0% +magnitude of that centripal acceleration + + + align:start position:0% +magnitude of that centripal acceleration +has gone up or down if you bring it + + align:start position:0% +has gone up or down if you bring it + + + align:start position:0% +has gone up or down if you bring it +closer to the axis + + align:start position:0% +closer to the axis + + + align:start position:0% +closer to the axis +down. Okay. So you can go faster to get + + align:start position:0% +down. Okay. So you can go faster to get + + + align:start position:0% +down. Okay. So you can go faster to get +up to the same uh level of acceleration + + align:start position:0% +up to the same uh level of acceleration + + + align:start position:0% +up to the same uh level of acceleration +where it'll break free. Next + + align:start position:0% + + + + align:start position:0% + +this is oh the natural frequency of the + + align:start position:0% +this is oh the natural frequency of the + + + align:start position:0% +this is oh the natural frequency of the +pendulum. Some of you said yes, some of + + align:start position:0% +pendulum. Some of you said yes, some of + + + align:start position:0% +pendulum. Some of you said yes, some of +you said no, some not sure. You're going + + align:start position:0% +you said no, some not sure. You're going + + + align:start position:0% +you said no, some not sure. You're going +to find out. you're going to figure out + + align:start position:0% +to find out. you're going to figure out + + + align:start position:0% +to find out. you're going to figure out +the equation of motion of the system and + + align:start position:0% +the equation of motion of the system and + + + align:start position:0% +the equation of motion of the system and +it includes that torsional spring and + + align:start position:0% +it includes that torsional spring and + + + align:start position:0% +it includes that torsional spring and +mass is definitely going to be in it. So + + align:start position:0% +mass is definitely going to be in it. So + + + align:start position:0% +mass is definitely going to be in it. So +look for an answer that includes ma uh + + align:start position:0% +look for an answer that includes ma uh + + + align:start position:0% +look for an answer that includes ma uh +that you'll see that + + align:start position:0% +that you'll see that + + + align:start position:0% +that you'll see that +mass is going to show up in a way that + + align:start position:0% +mass is going to show up in a way that + + + align:start position:0% +mass is going to show up in a way that +if you solve for the natural frequency + + align:start position:0% +if you solve for the natural frequency + + + align:start position:0% +if you solve for the natural frequency +it won't it won't be uh it won't leave + + align:start position:0% +it won't it won't be uh it won't leave + + + align:start position:0% +it won't it won't be uh it won't leave +the final equation. Okay. + + align:start position:0% +the final equation. Okay. + + + align:start position:0% +the final equation. Okay. +And + + align:start position:0% + + + + align:start position:0% + +So this is the one about the two masses. + + align:start position:0% +So this is the one about the two masses. + + + align:start position:0% +So this is the one about the two masses. +And if the spring were zero, the second + + align:start position:0% +And if the spring were zero, the second + + + align:start position:0% +And if the spring were zero, the second +natural frequency of the system, the + + align:start position:0% +natural frequency of the system, the + + + align:start position:0% +natural frequency of the system, the +first natural frequency, when you have a + + align:start position:0% +first natural frequency, when you have a + + + align:start position:0% +first natural frequency, when you have a +system that has what's called a rigid + + align:start position:0% +system that has what's called a rigid + + + align:start position:0% +system that has what's called a rigid +body degree of freedom, when this thing + + align:start position:0% +body degree of freedom, when this thing + + + align:start position:0% +body degree of freedom, when this thing +when there's no K1 spring, this system + + align:start position:0% +when there's no K1 spring, this system + + + align:start position:0% +when there's no K1 spring, this system +looks like two masses on wheels + + align:start position:0% +looks like two masses on wheels + + + align:start position:0% +looks like two masses on wheels +connected by a spring and a dash pot. + + align:start position:0% + + + + align:start position:0% + +And in the x direction there are no + + align:start position:0% +And in the x direction there are no + + + align:start position:0% +And in the x direction there are no +constraints. + + align:start position:0% +constraints. + + + align:start position:0% +constraints. +So if I set this system to vibrating, + + align:start position:0% +So if I set this system to vibrating, + + + align:start position:0% +So if I set this system to vibrating, +what can you say about the motion of its + + align:start position:0% +what can you say about the motion of its + + + align:start position:0% +what can you say about the motion of its +center of mass? + + align:start position:0% + + + + align:start position:0% + +So could you find the center of mass of + + align:start position:0% +So could you find the center of mass of + + + align:start position:0% +So could you find the center of mass of +that system? Got to give you the masses + + align:start position:0% +that system? Got to give you the masses + + + align:start position:0% +that system? Got to give you the masses +of it. But you have some m1 + + align:start position:0% +of it. But you have some m1 + + + align:start position:0% +of it. But you have some m1 +and an m2 and we'll give we'll call this + + align:start position:0% +and an m2 and we'll give we'll call this + + + align:start position:0% +and an m2 and we'll give we'll call this +the uh + + align:start position:0% + + + + align:start position:0% + +x in that direction. Could you determine + + align:start position:0% +x in that direction. Could you determine + + + align:start position:0% +x in that direction. Could you determine +the center of mass of the system? You + + align:start position:0% +the center of mass of the system? You + + + align:start position:0% +the center of mass of the system? You +know how to do that, right? It's going + + align:start position:0% +know how to do that, right? It's going + + + align:start position:0% +know how to do that, right? It's going +to be depend if they were equal in mass, + + align:start position:0% +to be depend if they were equal in mass, + + + align:start position:0% +to be depend if they were equal in mass, +it'd be right in the center. If this was + + align:start position:0% +it'd be right in the center. If this was + + + align:start position:0% +it'd be right in the center. If this was +bigger, it would be over here. Something + + align:start position:0% +bigger, it would be over here. Something + + + align:start position:0% +bigger, it would be over here. Something +like that. But so the we know that for a + + align:start position:0% +like that. But so the we know that for a + + + align:start position:0% +like that. But so the we know that for a +system of particles + + align:start position:0% +system of particles + + + align:start position:0% +system of particles +the sum of the external forces on the + + align:start position:0% +the sum of the external forces on the + + + align:start position:0% +the sum of the external forces on the +system is equal to the mass of the + + align:start position:0% +system is equal to the mass of the + + + align:start position:0% +system is equal to the mass of the +system times the acceleration of the + + align:start position:0% +system times the acceleration of the + + + align:start position:0% +system times the acceleration of the +what? + + align:start position:0% +what? + + + align:start position:0% +what? +Center of mass. + + align:start position:0% +Center of mass. + + + align:start position:0% +Center of mass. +What are the external forces in the + + align:start position:0% +What are the external forces in the + + + align:start position:0% +What are the external forces in the +horizontal direction? + + align:start position:0% + + + + align:start position:0% + +How big are they? + + align:start position:0% +How big are they? + + + align:start position:0% +How big are they? +Zero. Therefore, what can be the + + align:start position:0% +Zero. Therefore, what can be the + + + align:start position:0% +Zero. Therefore, what can be the +acceleration of the center of mass? + + align:start position:0% +acceleration of the center of mass? + + + align:start position:0% +acceleration of the center of mass? +Zero. This thing will actually in this + + align:start position:0% +Zero. This thing will actually in this + + + align:start position:0% +Zero. This thing will actually in this +second natural frequency it'll sit there + + align:start position:0% +second natural frequency it'll sit there + + + align:start position:0% +second natural frequency it'll sit there +and just oscillate back and forth. One + + align:start position:0% +and just oscillate back and forth. One + + + align:start position:0% +and just oscillate back and forth. One +mass going in one direction, one the + + align:start position:0% +mass going in one direction, one the + + + align:start position:0% +mass going in one direction, one the +other and but it center of mass won't + + align:start position:0% +other and but it center of mass won't + + + align:start position:0% +other and but it center of mass won't +move. The other degree of freedom and + + align:start position:0% +move. The other degree of freedom and + + + align:start position:0% +move. The other degree of freedom and +the other natural frequency, the one + + align:start position:0% +the other natural frequency, the one + + + align:start position:0% +the other natural frequency, the one +that has zero natural frequency is rigid + + align:start position:0% +that has zero natural frequency is rigid + + + align:start position:0% +that has zero natural frequency is rigid +body motion. No relative motion. Give + + align:start position:0% +body motion. No relative motion. Give + + + align:start position:0% +body motion. No relative motion. Give +this thing a little push, some initial + + align:start position:0% +this thing a little push, some initial + + + align:start position:0% +this thing a little push, some initial +momentum. It'll just sit there and roll + + align:start position:0% +momentum. It'll just sit there and roll + + + align:start position:0% +momentum. It'll just sit there and roll +forever. The mass is not moving relative + + align:start position:0% +forever. The mass is not moving relative + + + align:start position:0% +forever. The mass is not moving relative +to one another. It just rolls and rolls + + align:start position:0% +to one another. It just rolls and rolls + + + align:start position:0% +to one another. It just rolls and rolls +and rolls and rolls and never comes + + align:start position:0% +and rolls and rolls and never comes + + + align:start position:0% +and rolls and rolls and never comes +back. infinite period zero natural + + align:start position:0% +back. infinite period zero natural + + + align:start position:0% +back. infinite period zero natural +frequency. Okay, we're talking about + + align:start position:0% +frequency. Okay, we're talking about + + + align:start position:0% +frequency. Okay, we're talking about +fictitious forces the other day and um + + align:start position:0% +fictitious forces the other day and um + + + align:start position:0% +fictitious forces the other day and um +there are times when they are they're + + align:start position:0% +there are times when they are they're + + + align:start position:0% +there are times when they are they're +useful but they're sort of like giving a + + align:start position:0% +useful but they're sort of like giving a + + + align:start position:0% +useful but they're sort of like giving a +little kid a loaded gun. You know, you + + align:start position:0% +little kid a loaded gun. You know, you + + + align:start position:0% +little kid a loaded gun. You know, you +can really get yourself in trouble + + align:start position:0% +can really get yourself in trouble + + + align:start position:0% +can really get yourself in trouble +quickly. So, I'm not not advocating a + + align:start position:0% +quickly. So, I'm not not advocating a + + + align:start position:0% +quickly. So, I'm not not advocating a +lot of use of it, but it's good to have + + align:start position:0% +lot of use of it, but it's good to have + + + align:start position:0% +lot of use of it, but it's good to have +a little insight. One of one of the + + align:start position:0% +a little insight. One of one of the + + + align:start position:0% +a little insight. One of one of the +students when I after the lecture last + + align:start position:0% +students when I after the lecture last + + + align:start position:0% +students when I after the lecture last +time a student um mentioned to me he + + align:start position:0% +time a student um mentioned to me he + + + align:start position:0% +time a student um mentioned to me he +said the you know the way I was taught + + align:start position:0% +said the you know the way I was taught + + + align:start position:0% +said the you know the way I was taught +about fictitious forces is that we use + + align:start position:0% +about fictitious forces is that we use + + + align:start position:0% +about fictitious forces is that we use +them to patch up a problem when we're + + align:start position:0% +them to patch up a problem when we're + + + align:start position:0% +them to patch up a problem when we're +trying to work in a non-inertial frame. + + align:start position:0% +trying to work in a non-inertial frame. + + + align:start position:0% +trying to work in a non-inertial frame. +How can you make Newton's laws apply + + align:start position:0% +How can you make Newton's laws apply + + + align:start position:0% +How can you make Newton's laws apply +if you are in an in a non-inertial + + align:start position:0% +if you are in an in a non-inertial + + + align:start position:0% +if you are in an in a non-inertial +frame? Otherwise an accelerating + + align:start position:0% +frame? Otherwise an accelerating + + + align:start position:0% +frame? Otherwise an accelerating +reference frame. So, I just thought I + + align:start position:0% +reference frame. So, I just thought I + + + align:start position:0% +reference frame. So, I just thought I +would revisit a little bit of what we + + align:start position:0% +would revisit a little bit of what we + + + align:start position:0% +would revisit a little bit of what we +said the other day you with uh + + align:start position:0% +said the other day you with uh + + + align:start position:0% +said the other day you with uh +explaining things that way a little bit. + + align:start position:0% +explaining things that way a little bit. + + + align:start position:0% +explaining things that way a little bit. +So, it might just turn out to be + + align:start position:0% +So, it might just turn out to be + + + align:start position:0% +So, it might just turn out to be +familiar with you for you. And let's + + align:start position:0% +familiar with you for you. And let's + + + align:start position:0% +familiar with you for you. And let's +just look. + + align:start position:0% + + + + align:start position:0% + +This is go back quickly and revisit that + + align:start position:0% +This is go back quickly and revisit that + + + align:start position:0% +This is go back quickly and revisit that +elevator problem. So, you remember + + align:start position:0% +elevator problem. So, you remember + + + align:start position:0% +elevator problem. So, you remember +you're you're here. You got some mass m. + + align:start position:0% +you're you're here. You got some mass m. + + + align:start position:0% +you're you're here. You got some mass m. +You're standing on some scales. + + align:start position:0% +You're standing on some scales. + + + align:start position:0% +You're standing on some scales. +And I'm we want I want to know what the + + align:start position:0% +And I'm we want I want to know what the + + + align:start position:0% +And I'm we want I want to know what the +scales are going to read. Now, we did + + align:start position:0% +scales are going to read. Now, we did + + + align:start position:0% +scales are going to read. Now, we did +this one quickly the other day. I'm just + + align:start position:0% +this one quickly the other day. I'm just + + + align:start position:0% +this one quickly the other day. I'm just +going to revisit it. The uh + + align:start position:0% +going to revisit it. The uh + + + align:start position:0% +going to revisit it. The uh +and it's accelerating. This is point A. + + align:start position:0% +and it's accelerating. This is point A. + + + align:start position:0% +and it's accelerating. This is point A. +And here down here is O, my inertial + + align:start position:0% +And here down here is O, my inertial + + + align:start position:0% +And here down here is O, my inertial +frame. + + align:start position:0% + + + + align:start position:0% + +And the acceleration of A with respect + + align:start position:0% +And the acceleration of A with respect + + + align:start position:0% +And the acceleration of A with respect +to O is plus a quarter of G in the + + align:start position:0% +to O is plus a quarter of G in the + + + align:start position:0% +to O is plus a quarter of G in the +J hat direction. Okay. + + align:start position:0% +J hat direction. Okay. + + + align:start position:0% +J hat direction. Okay. +Now this thing when you think about this + + align:start position:0% +Now this thing when you think about this + + + align:start position:0% +Now this thing when you think about this +if you were want you're trying to do + + align:start position:0% +if you were want you're trying to do + + + align:start position:0% +if you were want you're trying to do +physics in the elevator but it's an + + align:start position:0% +physics in the elevator but it's an + + + align:start position:0% +physics in the elevator but it's an +accelerating frame. So Newton's laws + + align:start position:0% +accelerating frame. So Newton's laws + + + align:start position:0% +accelerating frame. So Newton's laws +don't apply. + + align:start position:0% +don't apply. + + + align:start position:0% +don't apply. +And in fact, so you're in the elevator, + + align:start position:0% +And in fact, so you're in the elevator, + + + align:start position:0% +And in fact, so you're in the elevator, +you can't see that you're accelerating, + + align:start position:0% +you can't see that you're accelerating, + + + align:start position:0% +you can't see that you're accelerating, +but you could measure your weight, for + + align:start position:0% +but you could measure your weight, for + + + align:start position:0% +but you could measure your weight, for +example. + + align:start position:0% +example. + + + align:start position:0% +example. +So, + + align:start position:0% +So, + + + align:start position:0% +So, +how do you fix up + + align:start position:0% +how do you fix up + + + align:start position:0% +how do you fix up +the + + align:start position:0% +the + + + align:start position:0% +the +equations so that you can predict the + + align:start position:0% +equations so that you can predict the + + + align:start position:0% +equations so that you can predict the +right answer? + + align:start position:0% +right answer? + + + align:start position:0% +right answer? +And to do that basically you have to add + + align:start position:0% +And to do that basically you have to add + + + align:start position:0% +And to do that basically you have to add +in + + align:start position:0% +in + + + align:start position:0% +in +a force a fictitious force that accounts + + align:start position:0% +a force a fictitious force that accounts + + + align:start position:0% +a force a fictitious force that accounts +for the + + align:start position:0% +for the + + + align:start position:0% +for the +additional forces you will feel in this + + align:start position:0% +additional forces you will feel in this + + + align:start position:0% +additional forces you will feel in this +system + + align:start position:0% +system + + + align:start position:0% +system +due to the acceleration. + + align:start position:0% +due to the acceleration. + + + align:start position:0% +due to the acceleration. +Okay. So + + align:start position:0% +Okay. So + + + align:start position:0% +Okay. So +remember the way we did this problem. If + + align:start position:0% +remember the way we did this problem. If + + + align:start position:0% +remember the way we did this problem. If +you do this problem just in the + + align:start position:0% +you do this problem just in the + + + align:start position:0% +you do this problem just in the +straightforward way, the summation of + + align:start position:0% +straightforward way, the summation of + + + align:start position:0% +straightforward way, the summation of +the external forces + + align:start position:0% +the external forces + + + align:start position:0% +the external forces +in the y direction + + align:start position:0% +in the y direction + + + align:start position:0% +in the y direction +is the mass times the acceleration a + + align:start position:0% +is the mass times the acceleration a + + + align:start position:0% +is the mass times the acceleration a +with respect to o. + + align:start position:0% +with respect to o. + + + align:start position:0% +with respect to o. +And we need a free body diagram. In the + + align:start position:0% +And we need a free body diagram. In the + + + align:start position:0% +And we need a free body diagram. In the +free body diagram of this just this mass + + align:start position:0% +free body diagram of this just this mass + + + align:start position:0% +free body diagram of this just this mass +here, + + align:start position:0% + + + + align:start position:0% + +you have an mg + + align:start position:0% +you have an mg + + + align:start position:0% +you have an mg +downwards and an n upwards. And so you'd + + align:start position:0% +downwards and an n upwards. And so you'd + + + align:start position:0% +downwards and an n upwards. And so you'd +say this is equal to n minus + + align:start position:0% + + + + align:start position:0% + +mg. + + align:start position:0% +mg. + + + align:start position:0% +mg. +Now + + align:start position:0% +Now + + + align:start position:0% +Now +if you are trying to do this experime + + align:start position:0% +if you are trying to do this experime + + + align:start position:0% +if you are trying to do this experime +you're doing this experiment inside you + + align:start position:0% +you're doing this experiment inside you + + + align:start position:0% +you're doing this experiment inside you +can measure this n that's going to be + + align:start position:0% +can measure this n that's going to be + + + align:start position:0% +can measure this n that's going to be +your weight and you would like to do + + align:start position:0% +your weight and you would like to do + + + align:start position:0% +your weight and you would like to do +this by fictitious forces you say that + + align:start position:0% +this by fictitious forces you say that + + + align:start position:0% +this by fictitious forces you say that +ah the uh + + align:start position:0% + + + + align:start position:0% + +summation of the external real forces + + align:start position:0% +summation of the external real forces + + + align:start position:0% +summation of the external real forces +minus + + align:start position:0% +minus + + + align:start position:0% +minus +this mass times the acceleration of A + + align:start position:0% +this mass times the acceleration of A + + + align:start position:0% +this mass times the acceleration of A +with respect to + + align:start position:0% +with respect to + + + align:start position:0% +with respect to +O has got to be equal to zero. And + + align:start position:0% +O has got to be equal to zero. And + + + align:start position:0% +O has got to be equal to zero. And +that's then + + align:start position:0% +that's then + + + align:start position:0% +that's then +N minus + + align:start position:0% +N minus + + + align:start position:0% +N minus +MG + + align:start position:0% +MG + + + align:start position:0% +MG +minus MG + + align:start position:0% +minus MG + + + align:start position:0% +minus MG +over 4. Here's your fictitious force. + + align:start position:0% + + + + align:start position:0% + +And that's as if then you've come over + + align:start position:0% +And that's as if then you've come over + + + align:start position:0% +And that's as if then you've come over +here and you've added + + align:start position:0% +here and you've added + + + align:start position:0% +here and you've added +a force an additional force on this free + + align:start position:0% +a force an additional force on this free + + + align:start position:0% +a force an additional force on this free +body diagram that looks like mg g over4. + + align:start position:0% +body diagram that looks like mg g over4. + + + align:start position:0% +body diagram that looks like mg g over4. +And now you say the sum of these forces + + align:start position:0% +And now you say the sum of these forces + + + align:start position:0% +And now you say the sum of these forces +this is the correction + + align:start position:0% +this is the correction + + + align:start position:0% +this is the correction +that's allowing you now to work in this + + align:start position:0% +that's allowing you now to work in this + + + align:start position:0% +that's allowing you now to work in this +accelerating frame. + + align:start position:0% +accelerating frame. + + + align:start position:0% +accelerating frame. +If you treat do this free body diagram + + align:start position:0% +If you treat do this free body diagram + + + align:start position:0% +If you treat do this free body diagram +and sum these up then you will find the + + align:start position:0% +and sum these up then you will find the + + + align:start position:0% +and sum these up then you will find the +uh + + align:start position:0% +uh + + + align:start position:0% +uh +this expression which you can solve for + + align:start position:0% +this expression which you can solve for + + + align:start position:0% +this expression which you can solve for +n and you'll get m 5 over 4 g. Okay, in + + align:start position:0% +n and you'll get m 5 over 4 g. Okay, in + + + align:start position:0% +n and you'll get m 5 over 4 g. Okay, in +fact if you stood in the scales that's + + align:start position:0% +fact if you stood in the scales that's + + + align:start position:0% +fact if you stood in the scales that's +what you get. + + align:start position:0% + + + + align:start position:0% + +All right. So, I want to I want to do + + align:start position:0% +All right. So, I want to I want to do + + + align:start position:0% +All right. So, I want to I want to do +this is example one. I want to do sort + + align:start position:0% +this is example one. I want to do sort + + + align:start position:0% +this is example one. I want to do sort +of example 1.5. The cable breaks + + align:start position:0% +of example 1.5. The cable breaks + + + align:start position:0% +of example 1.5. The cable breaks +on this elevator. + + align:start position:0% + + + + align:start position:0% + +Your free body diagram still has an mg + + align:start position:0% +Your free body diagram still has an mg + + + align:start position:0% +Your free body diagram still has an mg +on it. + + align:start position:0% +on it. + + + align:start position:0% +on it. +You're still inside. You're still + + align:start position:0% +You're still inside. You're still + + + align:start position:0% +You're still inside. You're still +measuring forces. + + align:start position:0% +measuring forces. + + + align:start position:0% +measuring forces. +And you want to use this idea of a + + align:start position:0% +And you want to use this idea of a + + + align:start position:0% +And you want to use this idea of a +fictitious force to help you sort out + + align:start position:0% +fictitious force to help you sort out + + + align:start position:0% +fictitious force to help you sort out +what forces will you feel inside that + + align:start position:0% +what forces will you feel inside that + + + align:start position:0% +what forces will you feel inside that +elevator. + + align:start position:0% +elevator. + + + align:start position:0% +elevator. +Okay? + + align:start position:0% +Okay? + + + align:start position:0% +Okay? +And + + align:start position:0% +And + + + align:start position:0% +And +so just just you know you know how to do + + align:start position:0% +so just just you know you know how to do + + + align:start position:0% +so just just you know you know how to do +the answer in the straightforward way. + + align:start position:0% +the answer in the straightforward way. + + + align:start position:0% +the answer in the straightforward way. +the ex sum of the external forces + + align:start position:0% +the ex sum of the external forces + + + align:start position:0% +the ex sum of the external forces +is minus mg + + align:start position:0% +is minus mg + + + align:start position:0% +is minus mg +and that's equal to the mass times the + + align:start position:0% +and that's equal to the mass times the + + + align:start position:0% +and that's equal to the mass times the +acceleration of a with respect to o and + + align:start position:0% +acceleration of a with respect to o and + + + align:start position:0% +acceleration of a with respect to o and +therefore + + align:start position:0% +therefore + + + align:start position:0% +therefore +acceleration of a with respect to o is + + align:start position:0% +acceleration of a with respect to o is + + + align:start position:0% +acceleration of a with respect to o is +just minus g right + + align:start position:0% + + + + align:start position:0% + +so + + align:start position:0% +so + + + align:start position:0% +so +mean and you could have told me that you + + align:start position:0% +mean and you could have told me that you + + + align:start position:0% +mean and you could have told me that you +know that's trivial that you drop the + + align:start position:0% +know that's trivial that you drop the + + + align:start position:0% +know that's trivial that you drop the +thing accelerates at the at acceleration + + align:start position:0% +thing accelerates at the at acceleration + + + align:start position:0% +thing accelerates at the at acceleration +of gravity. So, I want to think I want + + align:start position:0% +of gravity. So, I want to think I want + + + align:start position:0% +of gravity. So, I want to think I want +to know what's what's the how you're + + align:start position:0% +to know what's what's the how you're + + + align:start position:0% +to know what's what's the how you're +doing the experiment inside. You don't + + align:start position:0% +doing the experiment inside. You don't + + + align:start position:0% +doing the experiment inside. You don't +know that you're accelerating. All + + align:start position:0% +know that you're accelerating. All + + + align:start position:0% +know that you're accelerating. All +you're doing is measurements, but you've + + align:start position:0% +you're doing is measurements, but you've + + + align:start position:0% +you're doing is measurements, but you've +been you've been told how to correct it. + + align:start position:0% +been you've been told how to correct it. + + + align:start position:0% +been you've been told how to correct it. +So, let's put in the fictitious force, + + align:start position:0% +So, let's put in the fictitious force, + + + align:start position:0% +So, let's put in the fictitious force, +which is minus m a0. And that means mass + + align:start position:0% +which is minus m a0. And that means mass + + + align:start position:0% +which is minus m a0. And that means mass +times acceleration. + + align:start position:0% +times acceleration. + + + align:start position:0% +times acceleration. +This one + + align:start position:0% + + + + align:start position:0% + +the mass times the acceleration is + + align:start position:0% +the mass times the acceleration is + + + align:start position:0% +the mass times the acceleration is +downwards. So minus that the fictitious + + align:start position:0% +downwards. So minus that the fictitious + + + align:start position:0% +downwards. So minus that the fictitious +force is an mg g force upwards. And what + + align:start position:0% +force is an mg g force upwards. And what + + + align:start position:0% +force is an mg g force upwards. And what +do you feel? + + align:start position:0% + + + + align:start position:0% + +What do the scales read? + + align:start position:0% +What do the scales read? + + + align:start position:0% +What do the scales read? +Nothing. You feel absolutely nothing. + + align:start position:0% +Nothing. You feel absolutely nothing. + + + align:start position:0% +Nothing. You feel absolutely nothing. +Right? + + align:start position:0% +Right? + + + align:start position:0% +Right? +Okay. So just an aside kind of question. + + align:start position:0% + + + + align:start position:0% + +Because I know this is confused + + align:start position:0% +Because I know this is confused + + + align:start position:0% +Because I know this is confused +occasionally we all get confused around + + align:start position:0% +occasionally we all get confused around + + + align:start position:0% +occasionally we all get confused around +this is is gravity + + align:start position:0% +this is is gravity + + + align:start position:0% +this is is gravity +now in these pro problems that we do is + + align:start position:0% +now in these pro problems that we do is + + + align:start position:0% +now in these pro problems that we do is +gravity + + align:start position:0% +gravity + + + align:start position:0% +gravity +and acceleration. + + align:start position:0% + + + + align:start position:0% + +We all we say all the time I use the + + align:start position:0% +We all we say all the time I use the + + + align:start position:0% +We all we say all the time I use the +phrase the acceleration of gravity. How + + align:start position:0% +phrase the acceleration of gravity. How + + + align:start position:0% +phrase the acceleration of gravity. How +many times have you ever said that? Have + + align:start position:0% +many times have you ever said that? Have + + + align:start position:0% +many times have you ever said that? Have +you ever said that? The acceleration of + + align:start position:0% +you ever said that? The acceleration of + + + align:start position:0% +you ever said that? The acceleration of +gravity. What do we mean? What we mean + + align:start position:0% +gravity. What do we mean? What we mean + + + align:start position:0% +gravity. What do we mean? What we mean +is this is when you let something drop + + align:start position:0% +is this is when you let something drop + + + align:start position:0% +is this is when you let something drop +in freef fall, it'll accelerate at g. + + align:start position:0% +in freef fall, it'll accelerate at g. + + + align:start position:0% +in freef fall, it'll accelerate at g. +But the way we apply for when we're + + align:start position:0% +But the way we apply for when we're + + + align:start position:0% +But the way we apply for when we're +writing out equations of motion, we say + + align:start position:0% +writing out equations of motion, we say + + + align:start position:0% +writing out equations of motion, we say +the sum of the external forces is equal + + align:start position:0% +the sum of the external forces is equal + + + align:start position:0% +the sum of the external forces is equal +to mass times the acceleration. Where + + align:start position:0% +to mass times the acceleration. Where + + + align:start position:0% +to mass times the acceleration. Where +does gravity go? It's a force. + + align:start position:0% +does gravity go? It's a force. + + + align:start position:0% +does gravity go? It's a force. +So this is another thing not to let not + + align:start position:0% +So this is another thing not to let not + + + align:start position:0% +So this is another thing not to let not +to get confused by by is to think about + + align:start position:0% +to get confused by by is to think about + + + align:start position:0% +to get confused by by is to think about +gravity as being an acceleration. We + + align:start position:0% +gravity as being an acceleration. We + + + align:start position:0% +gravity as being an acceleration. We +spent a lot of time figuring out ways to + + align:start position:0% +spent a lot of time figuring out ways to + + + align:start position:0% +spent a lot of time figuring out ways to +write accelerations, right, in rotating, + + align:start position:0% +write accelerations, right, in rotating, + + + align:start position:0% +write accelerations, right, in rotating, +translating reference frames. Gravity + + align:start position:0% +translating reference frames. Gravity + + + align:start position:0% +translating reference frames. Gravity +never pops up in there. It always comes + + align:start position:0% +never pops up in there. It always comes + + + align:start position:0% +never pops up in there. It always comes +up on the force side of the equation. + + align:start position:0% +up on the force side of the equation. + + + align:start position:0% +up on the force side of the equation. +Okay. + + align:start position:0% + + + + align:start position:0% + +Ah. All right. So, one one last + + align:start position:0% + + + + align:start position:0% + +example from last time, but it's + + align:start position:0% +example from last time, but it's + + + align:start position:0% +example from last time, but it's +relevant to + + align:start position:0% +relevant to + + + align:start position:0% +relevant to +problem on the homework. So we have this + + align:start position:0% +problem on the homework. So we have this + + + align:start position:0% +problem on the homework. So we have this +shaft spinning. + + align:start position:0% +shaft spinning. + + + align:start position:0% +shaft spinning. +This is the Z-axis + + align:start position:0% +This is the Z-axis + + + align:start position:0% +This is the Z-axis +spinning at constant rate omega. + + align:start position:0% + + + + align:start position:0% + +And we'll use this is R + + align:start position:0% +And we'll use this is R + + + align:start position:0% +And we'll use this is R +hat and this is Z K hat. These are these + + align:start position:0% +hat and this is Z K hat. These are these + + + align:start position:0% +hat and this is Z K hat. These are these +two position. These are the length R hat + + align:start position:0% +two position. These are the length R hat + + + align:start position:0% +two position. These are the length R hat +direction and the height Z using + + align:start position:0% +direction and the height Z using + + + align:start position:0% +direction and the height Z using +cylindrical coordinates. And now I just + + align:start position:0% +cylindrical coordinates. And now I just + + + align:start position:0% +cylindrical coordinates. And now I just +want you to let's just use this notion + + align:start position:0% +want you to let's just use this notion + + + align:start position:0% +want you to let's just use this notion +of fictitious forces to figure out what + + align:start position:0% +of fictitious forces to figure out what + + + align:start position:0% +of fictitious forces to figure out what +the first what's the what's the + + align:start position:0% +the first what's the what's the + + + align:start position:0% +the first what's the what's the +fictitious force on this system. + + align:start position:0% +fictitious force on this system. + + + align:start position:0% +fictitious force on this system. +So we're trying to account you're out + + align:start position:0% +So we're trying to account you're out + + + align:start position:0% +So we're trying to account you're out +there remember this is now this notion + + align:start position:0% +there remember this is now this notion + + + align:start position:0% +there remember this is now this notion +of you're out there where this mass is + + align:start position:0% +of you're out there where this mass is + + + align:start position:0% +of you're out there where this mass is +you're riding with this mass and you're + + align:start position:0% +you're riding with this mass and you're + + + align:start position:0% +you're riding with this mass and you're +trying to say what are the forces what + + align:start position:0% +trying to say what are the forces what + + + align:start position:0% +trying to say what are the forces what +forces am I going to feel? You want to + + align:start position:0% +forces am I going to feel? You want to + + + align:start position:0% +forces am I going to feel? You want to +be able to predict it correctly. So you + + align:start position:0% +be able to predict it correctly. So you + + + align:start position:0% +be able to predict it correctly. So you +have to find a fictitious force that you + + align:start position:0% +have to find a fictitious force that you + + + align:start position:0% +have to find a fictitious force that you +can bring in that accounts for an + + align:start position:0% +can bring in that accounts for an + + + align:start position:0% +can bring in that accounts for an +acceleration. And what acceleration is + + align:start position:0% +acceleration. And what acceleration is + + + align:start position:0% +acceleration. And what acceleration is +are we feeling out there? + + align:start position:0% +are we feeling out there? + + + align:start position:0% +are we feeling out there? +Centripal, right? And the centripal + + align:start position:0% +Centripal, right? And the centripal + + + align:start position:0% +Centripal, right? And the centripal +acceleration + + align:start position:0% +acceleration + + + align:start position:0% +acceleration +the uh we want the sum of the external + + align:start position:0% +the uh we want the sum of the external + + + align:start position:0% +the uh we want the sum of the external +forces + + align:start position:0% +forces + + + align:start position:0% +forces +and this is going to be in the r hat + + align:start position:0% +and this is going to be in the r hat + + + align:start position:0% +and this is going to be in the r hat +direction + + align:start position:0% +direction + + + align:start position:0% +direction +minus + + align:start position:0% +minus + + + align:start position:0% +minus +m times the and now this is we need + + align:start position:0% +m times the and now this is we need + + + align:start position:0% +m times the and now this is we need +reference frames here. So you have a + + align:start position:0% +reference frames here. So you have a + + + align:start position:0% +reference frames here. So you have a +fixed frame O + + align:start position:0% +fixed frame O + + + align:start position:0% +fixed frame O +XY you have a rotating frame here A X + + align:start position:0% +XY you have a rotating frame here A X + + + align:start position:0% +XY you have a rotating frame here A X +prime Yprime Zprime and this is your + + align:start position:0% +prime Yprime Zprime and this is your + + + align:start position:0% +prime Yprime Zprime and this is your +point B up here. + + align:start position:0% +point B up here. + + + align:start position:0% +point B up here. +So + + align:start position:0% +So + + + align:start position:0% +So +the sum of the external forces minus the + + align:start position:0% +the sum of the external forces minus the + + + align:start position:0% +the sum of the external forces minus the +mass times the acceleration of B with + + align:start position:0% +mass times the acceleration of B with + + + align:start position:0% +mass times the acceleration of B with +respect to zero is got to be equal to + + align:start position:0% +respect to zero is got to be equal to + + + align:start position:0% +respect to zero is got to be equal to +zero. That's how that's what this how + + align:start position:0% +zero. That's how that's what this how + + + align:start position:0% +zero. That's how that's what this how +this fictitious force thing works. So + + align:start position:0% +this fictitious force thing works. So + + + align:start position:0% +this fictitious force thing works. So +what on the free body diagram of this + + align:start position:0% +what on the free body diagram of this + + + align:start position:0% +what on the free body diagram of this +thing, what are the actual forces on it? + + align:start position:0% +thing, what are the actual forces on it? + + + align:start position:0% +thing, what are the actual forces on it? +Well, this rod has to there's certainly + + align:start position:0% +Well, this rod has to there's certainly + + + align:start position:0% +Well, this rod has to there's certainly +a weight + + align:start position:0% +a weight + + + align:start position:0% +a weight +downwards. + + align:start position:0% +downwards. + + + align:start position:0% +downwards. +There must be some supporting force + + align:start position:0% +There must be some supporting force + + + align:start position:0% +There must be some supporting force +upwards because we'll put that in in the + + align:start position:0% +upwards because we'll put that in in the + + + align:start position:0% +upwards because we'll put that in in the +Z direction here because this thing + + align:start position:0% +Z direction here because this thing + + + align:start position:0% +Z direction here because this thing +certainly doesn't accelerate up and + + align:start position:0% +certainly doesn't accelerate up and + + + align:start position:0% +certainly doesn't accelerate up and +down. So, the rod's lifting it up + + align:start position:0% +down. So, the rod's lifting it up + + + align:start position:0% +down. So, the rod's lifting it up +somehow. The rod is also putting on some + + align:start position:0% +somehow. The rod is also putting on some + + + align:start position:0% +somehow. The rod is also putting on some +has potentially some radial component + + align:start position:0% +has potentially some radial component + + + align:start position:0% +has potentially some radial component +and I'm just drawing it in the positive + + align:start position:0% +and I'm just drawing it in the positive + + + align:start position:0% +and I'm just drawing it in the positive +direction. And those those are my + + align:start position:0% +direction. And those those are my + + + align:start position:0% +direction. And those those are my +forces. + + align:start position:0% +forces. + + + align:start position:0% +forces. +And we've in this problem omega dot + + align:start position:0% +And we've in this problem omega dot + + + align:start position:0% +And we've in this problem omega dot +theta dot equals zero and r dot and r + + align:start position:0% +theta dot equals zero and r dot and r + + + align:start position:0% +theta dot equals zero and r dot and r +dot were zero. So it's constant rotation + + align:start position:0% +dot were zero. So it's constant rotation + + + align:start position:0% +dot were zero. So it's constant rotation +rate. No geometry changes here. + + align:start position:0% +rate. No geometry changes here. + + + align:start position:0% +rate. No geometry changes here. +Okay. So we did we cranked cranked + + align:start position:0% +Okay. So we did we cranked cranked + + + align:start position:0% +Okay. So we did we cranked cranked +through this problem before. And now I + + align:start position:0% +through this problem before. And now I + + + align:start position:0% +through this problem before. And now I +want to make this correction. And I want + + align:start position:0% +want to make this correction. And I want + + + align:start position:0% +want to make this correction. And I want +to add this fictitious force in the + + align:start position:0% +to add this fictitious force in the + + + align:start position:0% +to add this fictitious force in the +acceleration is minus r omega^ 2 in the + + align:start position:0% +acceleration is minus r omega^ 2 in the + + + align:start position:0% +acceleration is minus r omega^ 2 in the +r hat direction. So minus m * that is a + + align:start position:0% +r hat direction. So minus m * that is a + + + align:start position:0% +r hat direction. So minus m * that is a +plus I get an m + + align:start position:0% + + + + align:start position:0% + +r + + align:start position:0% +r + + + align:start position:0% +r +omega squared + + align:start position:0% + + + + align:start position:0% + +and pointing outwards. + + align:start position:0% +and pointing outwards. + + + align:start position:0% +and pointing outwards. +Okay. And so the sum of the forces + + align:start position:0% +Okay. And so the sum of the forces + + + align:start position:0% +Okay. And so the sum of the forces +in the radial direction + + align:start position:0% + + + + align:start position:0% + +minus or + + align:start position:0% +minus or + + + align:start position:0% +minus or +sum of the forces in the radial + + align:start position:0% +sum of the forces in the radial + + + align:start position:0% +sum of the forces in the radial +direction now + + align:start position:0% +direction now + + + align:start position:0% +direction now +minus this m a b with respect to o. + + align:start position:0% +minus this m a b with respect to o. + + + align:start position:0% +minus this m a b with respect to o. +Well, what are the sum of the real + + align:start position:0% +Well, what are the sum of the real + + + align:start position:0% +Well, what are the sum of the real +forces? Just nr + + align:start position:0% +forces? Just nr + + + align:start position:0% +forces? Just nr +and this minus mass times the + + align:start position:0% +and this minus mass times the + + + align:start position:0% +and this minus mass times the +acceleration. That's your m r 2 + + align:start position:0% +acceleration. That's your m r 2 + + + align:start position:0% +acceleration. That's your m r 2 +m r omega squ and that's got to be zero. + + align:start position:0% +m r omega squ and that's got to be zero. + + + align:start position:0% +m r omega squ and that's got to be zero. +So you find out that this there is a + + align:start position:0% + + + + align:start position:0% + +all is zero. Therefore, + + align:start position:0% +all is zero. Therefore, + + + align:start position:0% +all is zero. Therefore, +solve for nr is minus + + align:start position:0% +solve for nr is minus + + + align:start position:0% +solve for nr is minus +m r omega^ 2. So that rod out here is + + align:start position:0% +m r omega^ 2. So that rod out here is + + + align:start position:0% +m r omega^ 2. So that rod out here is +pulling that constantly pulling it in to + + align:start position:0% +pulling that constantly pulling it in to + + + align:start position:0% +pulling that constantly pulling it in to +make it go around the circle. And but + + align:start position:0% +make it go around the circle. And but + + + align:start position:0% +make it go around the circle. And but +we've just done this now by this notion + + align:start position:0% +we've just done this now by this notion + + + align:start position:0% +we've just done this now by this notion +of a fictitious force. So + + align:start position:0% +of a fictitious force. So + + + align:start position:0% +of a fictitious force. So +let's go back to this problem now. Well, + + align:start position:0% +let's go back to this problem now. Well, + + + align:start position:0% +let's go back to this problem now. Well, +actually, I'll just take one final step. + + align:start position:0% +actually, I'll just take one final step. + + + align:start position:0% +actually, I'll just take one final step. +If that's the here's your now your um + + align:start position:0% +If that's the here's your now your um + + + align:start position:0% +If that's the here's your now your um +free body diagram touched up with this + + align:start position:0% +free body diagram touched up with this + + + align:start position:0% +free body diagram touched up with this +fictitious force so that we can work as + + align:start position:0% +fictitious force so that we can work as + + + align:start position:0% +fictitious force so that we can work as +if we're here. And by the way, if you + + align:start position:0% +if we're here. And by the way, if you + + + align:start position:0% +if we're here. And by the way, if you +could, you know, if you uh could + + align:start position:0% +could, you know, if you uh could + + + align:start position:0% +could, you know, if you uh could +measure, if you had a strain gauge or + + align:start position:0% +measure, if you had a strain gauge or + + + align:start position:0% +measure, if you had a strain gauge or +something, so you could measure the + + align:start position:0% +something, so you could measure the + + + align:start position:0% +something, so you could measure the +force + + align:start position:0% +force + + + align:start position:0% +force +that this rod + + align:start position:0% +that this rod + + + align:start position:0% +that this rod +is putting on that mass. If you can + + align:start position:0% +is putting on that mass. If you can + + + align:start position:0% +is putting on that mass. If you can +measure it out there, this would be what + + align:start position:0% +measure it out there, this would be what + + + align:start position:0% +measure it out there, this would be what +you would measure. + + align:start position:0% +you would measure. + + + align:start position:0% +you would measure. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Now, what about the torque that that + + align:start position:0% +Now, what about the torque that that + + + align:start position:0% +Now, what about the torque that that +force + + align:start position:0% +force + + + align:start position:0% +force +creates around here? + + align:start position:0% + + + + align:start position:0% + +So you have an outward force m r omega + + align:start position:0% +So you have an outward force m r omega + + + align:start position:0% +So you have an outward force m r omega +squar that's cent c c c c c c c c c c c + + align:start position:0% +squar that's cent c c c c c c c c c c c + + + align:start position:0% +squar that's cent c c c c c c c c c c c +c c c c c c c c c centrifugal force this + + align:start position:0% +c c c c c c c c c centrifugal force this + + + align:start position:0% +c c c c c c c c c centrifugal force this +fictitious force + + align:start position:0% +fictitious force + + + align:start position:0% +fictitious force +going pulling out up here what moment + + align:start position:0% +going pulling out up here what moment + + + align:start position:0% +going pulling out up here what moment +does that create down here + + align:start position:0% + + + + align:start position:0% + +what's the magnitude first + + align:start position:0% + + + + align:start position:0% + +and that'll be a torque + + align:start position:0% + + + + align:start position:0% + +around + + align:start position:0% +around + + + align:start position:0% +around +say in the theta direction. + + align:start position:0% + + + + align:start position:0% + +So what's the moment arm? + + align:start position:0% +So what's the moment arm? + + + align:start position:0% +So what's the moment arm? +The moment arm + + align:start position:0% +The moment arm + + + align:start position:0% +The moment arm +the moment arm Z. Okay. So then the + + align:start position:0% +the moment arm Z. Okay. So then the + + + align:start position:0% +the moment arm Z. Okay. So then the +torque is going to be for R cross F and + + align:start position:0% +torque is going to be for R cross F and + + + align:start position:0% +torque is going to be for R cross F and +it's going to be the uh M R Z omega^ 2 + + align:start position:0% +it's going to be the uh M R Z omega^ 2 + + + align:start position:0% +it's going to be the uh M R Z omega^ 2 +Okay. And it's trying to that centripal + + align:start position:0% +Okay. And it's trying to that centripal + + + align:start position:0% +Okay. And it's trying to that centripal +force is trying to bend it out. + + align:start position:0% +force is trying to bend it out. + + + align:start position:0% +force is trying to bend it out. +Therefore, the torque down here required + + align:start position:0% +Therefore, the torque down here required + + + align:start position:0% +Therefore, the torque down here required +to keep it from doing so is actually in + + align:start position:0% +to keep it from doing so is actually in + + + align:start position:0% +to keep it from doing so is actually in +the other direction. + + align:start position:0% +the other direction. + + + align:start position:0% +the other direction. +So the torque that this system must put + + align:start position:0% +So the torque that this system must put + + + align:start position:0% +So the torque that this system must put +on this bar is minus. + + align:start position:0% +on this bar is minus. + + + align:start position:0% +on this bar is minus. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So let's go to this problem. If this is + + align:start position:0% +So let's go to this problem. If this is + + + align:start position:0% +So let's go to this problem. If this is +the point about which we're computing + + align:start position:0% +the point about which we're computing + + + align:start position:0% +the point about which we're computing +the moments, then there's centrip + + align:start position:0% +the moments, then there's centrip + + + align:start position:0% +the moments, then there's centrip +centripal accelerations in this problem. + + align:start position:0% +centripal accelerations in this problem. + + + align:start position:0% +centripal accelerations in this problem. +But in what direction are they? + + align:start position:0% + + + + align:start position:0% + +Either one of those masses. + + align:start position:0% + + + + align:start position:0% + +Pardon? + + align:start position:0% +Pardon? + + + align:start position:0% +Pardon? +So each little mass like one of those + + align:start position:0% +So each little mass like one of those + + + align:start position:0% +So each little mass like one of those +the upper mass m over two it's spinning + + align:start position:0% +the upper mass m over two it's spinning + + + align:start position:0% +the upper mass m over two it's spinning +and it's shown in its as it's coming + + align:start position:0% +and it's shown in its as it's coming + + + align:start position:0% +and it's shown in its as it's coming +around the wheel. It's up at the top. + + align:start position:0% +around the wheel. It's up at the top. + + + align:start position:0% +around the wheel. It's up at the top. +What direction is the fictitious force + + align:start position:0% +What direction is the fictitious force + + + align:start position:0% +What direction is the fictitious force +that it's putting on that system? + + align:start position:0% +that it's putting on that system? + + + align:start position:0% +that it's putting on that system? +Radial outwards, right? And does it have + + align:start position:0% +Radial outwards, right? And does it have + + + align:start position:0% +Radial outwards, right? And does it have +any moment arm? That force going up with + + align:start position:0% +any moment arm? That force going up with + + + align:start position:0% +any moment arm? That force going up with +respect to that point in the center? No. + + align:start position:0% +respect to that point in the center? No. + + + align:start position:0% +respect to that point in the center? No. +So, it creates no moment. The bottom one + + align:start position:0% +So, it creates no moment. The bottom one + + + align:start position:0% +So, it creates no moment. The bottom one +by just symmetry doesn't either. This + + align:start position:0% +by just symmetry doesn't either. This + + + align:start position:0% +by just symmetry doesn't either. This +one over here, + + align:start position:0% +one over here, + + + align:start position:0% +one over here, +it also has a a fictitious force you can + + align:start position:0% +it also has a a fictitious force you can + + + align:start position:0% +it also has a a fictitious force you can +think of. which is outward m omega squar + + align:start position:0% +think of. which is outward m omega squar + + + align:start position:0% +think of. which is outward m omega squar +what's its moment arm with respect to + + align:start position:0% +what's its moment arm with respect to + + + align:start position:0% +what's its moment arm with respect to +that to our origin here zero again it + + align:start position:0% +that to our origin here zero again it + + + align:start position:0% +that to our origin here zero again it +produces no moment it produces an + + align:start position:0% +produces no moment it produces an + + + align:start position:0% +produces no moment it produces an +unbalanced force though right it's going + + align:start position:0% +unbalanced force though right it's going + + + align:start position:0% +unbalanced force though right it's going +around producing an unbalanced force uh + + align:start position:0% +around producing an unbalanced force uh + + + align:start position:0% +around producing an unbalanced force uh +this problem the upper one's the + + align:start position:0% +this problem the upper one's the + + + align:start position:0% +this problem the upper one's the +fictitious forces up the lower one which + + align:start position:0% +fictitious forces up the lower one which + + + align:start position:0% +fictitious forces up the lower one which +direction is it + + align:start position:0% +direction is it + + + align:start position:0% +direction is it +down it's perfectly balanced they're + + align:start position:0% +down it's perfectly balanced they're + + + align:start position:0% +down it's perfectly balanced they're +just equal and opposite just going + + align:start position:0% +just equal and opposite just going + + + align:start position:0% +just equal and opposite just going +around you'd feel no you'd feel nothing + + align:start position:0% +around you'd feel no you'd feel nothing + + + align:start position:0% +around you'd feel no you'd feel nothing +uncomfortable this one you'd feel this + + align:start position:0% +uncomfortable this one you'd feel this + + + align:start position:0% +uncomfortable this one you'd feel this +motorcycle trying to hop down the road. + + align:start position:0% +motorcycle trying to hop down the road. + + + align:start position:0% +motorcycle trying to hop down the road. +Okay, it really happens, right? But this + + align:start position:0% +Okay, it really happens, right? But this + + + align:start position:0% +Okay, it really happens, right? But this +one, what happens? + + align:start position:0% +one, what happens? + + + align:start position:0% +one, what happens? +Does this mass m over2, what direction + + align:start position:0% +Does this mass m over2, what direction + + + align:start position:0% +Does this mass m over2, what direction +is the centripal acceleration? I'll + + align:start position:0% +is the centripal acceleration? I'll + + + align:start position:0% +is the centripal acceleration? I'll +change the wording a little bit. The + + align:start position:0% +change the wording a little bit. The + + + align:start position:0% +change the wording a little bit. The +upper mass in case B, which direction is + + align:start position:0% +upper mass in case B, which direction is + + + align:start position:0% +upper mass in case B, which direction is +the centripal acceleration? + + align:start position:0% +the centripal acceleration? + + + align:start position:0% +the centripal acceleration? +Straight down, right? And the bottom + + align:start position:0% +Straight down, right? And the bottom + + + align:start position:0% +Straight down, right? And the bottom +mass, what direction? + + align:start position:0% +mass, what direction? + + + align:start position:0% +mass, what direction? +Straight up. + + align:start position:0% +Straight up. + + + align:start position:0% +Straight up. +Straight up. And the fictitious forces + + align:start position:0% +Straight up. And the fictitious forces + + + align:start position:0% +Straight up. And the fictitious forces +that are that reflect those two + + align:start position:0% +that are that reflect those two + + + align:start position:0% +that are that reflect those two +accelerations are the top one is up and + + align:start position:0% +accelerations are the top one is up and + + + align:start position:0% +accelerations are the top one is up and +the bottom one is down. But they produce + + align:start position:0% +the bottom one is down. But they produce + + + align:start position:0% +the bottom one is down. But they produce +a a net that do they have a moment arm + + align:start position:0% +a a net that do they have a moment arm + + + align:start position:0% +a a net that do they have a moment arm +that they act on with respect to that + + align:start position:0% +that they act on with respect to that + + + align:start position:0% +that they act on with respect to that +center. Yeah. This little distance here + + align:start position:0% +center. Yeah. This little distance here + + + align:start position:0% +center. Yeah. This little distance here +I think it's called B in the problem. So + + align:start position:0% +I think it's called B in the problem. So + + + align:start position:0% +I think it's called B in the problem. So +this thing m over two r omega^ 2* b is a + + align:start position:0% +this thing m over two r omega^ 2* b is a + + + align:start position:0% +this thing m over two r omega^ 2* b is a +torque about the x- axis. And this one + + align:start position:0% +torque about the x- axis. And this one + + + align:start position:0% +torque about the x- axis. And this one +down here is another m over 2 r omega^ + + align:start position:0% +down here is another m over 2 r omega^ + + + align:start position:0% +down here is another m over 2 r omega^ +2. And it's another torque in the same + + align:start position:0% +2. And it's another torque in the same + + + align:start position:0% +2. And it's another torque in the same +direction. So this thing produces quite + + align:start position:0% +direction. So this thing produces quite + + + align:start position:0% +direction. So this thing produces quite +a strong moment. But the but the wheel + + align:start position:0% +a strong moment. But the but the wheel + + + align:start position:0% +a strong moment. But the but the wheel +as the wheel turns + + align:start position:0% +as the wheel turns + + + align:start position:0% +as the wheel turns +that moment goes + + align:start position:0% + + + + align:start position:0% + +starts off it's about the x axis here. + + align:start position:0% +starts off it's about the x axis here. + + + align:start position:0% +starts off it's about the x axis here. +But when that weight gets to 90 degrees, + + align:start position:0% +But when that weight gets to 90 degrees, + + + align:start position:0% +But when that weight gets to 90 degrees, +what direction is the moment + + align:start position:0% + + + + align:start position:0% + +switches to the all the way around to + + align:start position:0% +switches to the all the way around to + + + align:start position:0% +switches to the all the way around to +the the y axis? + + align:start position:0% +the the y axis? + + + align:start position:0% +the the y axis? +Okay, so it's going to be a moment. The + + align:start position:0% +Okay, so it's going to be a moment. The + + + align:start position:0% +Okay, so it's going to be a moment. The +answer to this problem is going to look + + align:start position:0% +answer to this problem is going to look + + + align:start position:0% +answer to this problem is going to look +in time is going to look something like + + align:start position:0% +in time is going to look something like + + + align:start position:0% +in time is going to look something like +m r omega^ 2 z sin or cosine omega t. So + + align:start position:0% +m r omega^ 2 z sin or cosine omega t. So + + + align:start position:0% +m r omega^ 2 z sin or cosine omega t. So +the moment in this around the x- axis is + + align:start position:0% +the moment in this around the x- axis is + + + align:start position:0% +the moment in this around the x- axis is +kind it's going to be trying to the + + align:start position:0% +kind it's going to be trying to the + + + align:start position:0% +kind it's going to be trying to the +bike's going to be trying to go back and + + align:start position:0% +bike's going to be trying to go back and + + + align:start position:0% +bike's going to be trying to go back and +forth like this. Okay. At ome with + + align:start position:0% +forth like this. Okay. At ome with + + + align:start position:0% +forth like this. Okay. At ome with +frequency omega. Okay. + + align:start position:0% + + + + align:start position:0% + +So let's um I was going to say that's it + + align:start position:0% +So let's um I was going to say that's it + + + align:start position:0% +So let's um I was going to say that's it +for fictitious forces but it's not. I + + align:start position:0% +for fictitious forces but it's not. I + + + align:start position:0% +for fictitious forces but it's not. I +got a great demo for you. + + align:start position:0% + + + + align:start position:0% + +All right, + + align:start position:0% + + + + align:start position:0% + +we have a slope. + + align:start position:0% + + + + align:start position:0% + +I've got a cart + + align:start position:0% +I've got a cart + + + align:start position:0% +I've got a cart +on wheels here. And I actually do + + align:start position:0% + + + + align:start position:0% + +Okay. + + align:start position:0% + + + + align:start position:0% + +And I'm going to put a + + align:start position:0% +And I'm going to put a + + + align:start position:0% +And I'm going to put a +box here. + + align:start position:0% +box here. + + + align:start position:0% +box here. +And in the box, I got the wrong color + + align:start position:0% +And in the box, I got the wrong color + + + align:start position:0% +And in the box, I got the wrong color +here, but I'll try colored chalk for the + + align:start position:0% +here, but I'll try colored chalk for the + + + align:start position:0% +here, but I'll try colored chalk for the +first time. In the box, I've got a + + align:start position:0% +first time. In the box, I've got a + + + align:start position:0% +first time. In the box, I've got a +fluid. + + align:start position:0% + + + + align:start position:0% + +Okay. And the box has a lid on it so I + + align:start position:0% +Okay. And the box has a lid on it so I + + + align:start position:0% +Okay. And the box has a lid on it so I +don't make a mess. + + align:start position:0% + + + + align:start position:0% + +Now, I'm going to + + align:start position:0% +Now, I'm going to + + + align:start position:0% +Now, I'm going to +I'm actually going to do this + + align:start position:0% +I'm actually going to do this + + + align:start position:0% +I'm actually going to do this +experiment. I brought my ramp. We're + + align:start position:0% +experiment. I brought my ramp. We're + + + align:start position:0% +experiment. I brought my ramp. We're +going to set up this ramp. This box is + + align:start position:0% +going to set up this ramp. This box is + + + align:start position:0% +going to set up this ramp. This box is +going to be rolling down this hill and + + align:start position:0% +going to be rolling down this hill and + + + align:start position:0% +going to be rolling down this hill and +basically not no losses, no friction + + align:start position:0% +basically not no losses, no friction + + + align:start position:0% +basically not no losses, no friction +holding it back. It's just going to be + + align:start position:0% +holding it back. It's just going to be + + + align:start position:0% +holding it back. It's just going to be +able to take off and accelerate down + + align:start position:0% +able to take off and accelerate down + + + align:start position:0% +able to take off and accelerate down +that hill. + + align:start position:0% +that hill. + + + align:start position:0% +that hill. +Um, + + align:start position:0% +Um, + + + align:start position:0% +Um, +and I want to know + + align:start position:0% +and I want to know + + + align:start position:0% +and I want to know +A, + + align:start position:0% +A, + + + align:start position:0% +A, +B, C. + + align:start position:0% +B, C. + + + align:start position:0% +B, C. +When it's rolling down that hill, will + + align:start position:0% +When it's rolling down that hill, will + + + align:start position:0% +When it's rolling down that hill, will +the level will the bo fluid in the box + + align:start position:0% + + + + align:start position:0% + +look like that? + + align:start position:0% +look like that? + + + align:start position:0% +look like that? +Look like + + align:start position:0% + + + + align:start position:0% + +that or + + align:start position:0% + + + + align:start position:0% + +like that. + + align:start position:0% + + + + align:start position:0% + +So, we're going to take our poll here. + + align:start position:0% +So, we're going to take our poll here. + + + align:start position:0% +So, we're going to take our poll here. +So, how many believe that + + align:start position:0% +So, how many believe that + + + align:start position:0% +So, how many believe that +when it's rolling down the hill, the + + align:start position:0% +when it's rolling down the hill, the + + + align:start position:0% +when it's rolling down the hill, the +fluid will stay level, parallel to the + + align:start position:0% +fluid will stay level, parallel to the + + + align:start position:0% +fluid will stay level, parallel to the +ground? Let's raise your hands if you + + align:start position:0% +ground? Let's raise your hands if you + + + align:start position:0% +ground? Let's raise your hands if you +think this I want everybody to make a + + align:start position:0% +think this I want everybody to make a + + + align:start position:0% +think this I want everybody to make a +guess here. Everybody get in. Raise them + + align:start position:0% +guess here. Everybody get in. Raise them + + + align:start position:0% +guess here. Everybody get in. Raise them +high if you think it's going to stay + + align:start position:0% +high if you think it's going to stay + + + align:start position:0% +high if you think it's going to stay +level. + + align:start position:0% +level. + + + align:start position:0% +level. +Okay, maybe a quarter of you. How many + + align:start position:0% +Okay, maybe a quarter of you. How many + + + align:start position:0% +Okay, maybe a quarter of you. How many +think it's going to do this? + + align:start position:0% +think it's going to do this? + + + align:start position:0% +think it's going to do this? +Okay, a few more. And how many think + + align:start position:0% +Okay, a few more. And how many think + + + align:start position:0% +Okay, a few more. And how many think +it's going to do this? + + align:start position:0% +it's going to do this? + + + align:start position:0% +it's going to do this? +All right, so I want you to, you know, + + align:start position:0% +All right, so I want you to, you know, + + + align:start position:0% +All right, so I want you to, you know, +get in natural little groups there of + + align:start position:0% +get in natural little groups there of + + + align:start position:0% +get in natural little groups there of +two or three people and talk about this + + align:start position:0% +two or three people and talk about this + + + align:start position:0% +two or three people and talk about this +for a couple of minutes and see if you + + align:start position:0% +for a couple of minutes and see if you + + + align:start position:0% +for a couple of minutes and see if you +can convince your neighbor that you're + + align:start position:0% +can convince your neighbor that you're + + + align:start position:0% +can convince your neighbor that you're +right. Figure this out. Stop and talk + + align:start position:0% +right. Figure this out. Stop and talk + + + align:start position:0% +right. Figure this out. Stop and talk +about it. + + align:start position:0% + + + + align:start position:0% + +And and let's set up to do the + + align:start position:0% +And and let's set up to do the + + + align:start position:0% +And and let's set up to do the +experiment. + + align:start position:0% + + + + align:start position:0% + +Actually, I think if we do it up here. + + align:start position:0% +Actually, I think if we do it up here. + + + align:start position:0% +Actually, I think if we do it up here. +Yeah. So, like that. + + align:start position:0% + + + + align:start position:0% + +So, you hold the ramp. Yeah. You come + + align:start position:0% +So, you hold the ramp. Yeah. You come + + + align:start position:0% +So, you hold the ramp. Yeah. You come +here. + + align:start position:0% +here. + + + align:start position:0% +here. +[Music] + + align:start position:0% +[Music] + + + align:start position:0% +[Music] +We'll just practice our setup here for a + + align:start position:0% +We'll just practice our setup here for a + + + align:start position:0% +We'll just practice our setup here for a +second. So, you're going to have to hold + + align:start position:0% +second. So, you're going to have to hold + + + align:start position:0% +second. So, you're going to have to hold +it quite a bit higher. + + align:start position:0% +it quite a bit higher. + + + align:start position:0% +it quite a bit higher. +Okay. And actually now when we get it + + align:start position:0% +Okay. And actually now when we get it + + + align:start position:0% +Okay. And actually now when we get it +ready to go. + + align:start position:0% +ready to go. + + + align:start position:0% +ready to go. +How sealed is that? + + align:start position:0% +How sealed is that? + + + align:start position:0% +How sealed is that? +Pardon? Very well sealed. So I'm going + + align:start position:0% +Pardon? Very well sealed. So I'm going + + + align:start position:0% +Pardon? Very well sealed. So I'm going +to have you also you hold it and you + + align:start position:0% +to have you also you hold it and you + + + align:start position:0% +to have you also you hold it and you +release it. Right. And that's about the + + align:start position:0% +release it. Right. And that's about the + + + align:start position:0% +release it. Right. And that's about the +right because I got to catch it so it + + align:start position:0% +right because I got to catch it so it + + + align:start position:0% +right because I got to catch it so it +doesn't uh + + align:start position:0% +doesn't uh + + + align:start position:0% +doesn't uh +All right. Now we're going to stop. + + align:start position:0% +All right. Now we're going to stop. + + + align:start position:0% +All right. Now we're going to stop. +We're not going to do it right away. I'm + + align:start position:0% +We're not going to do it right away. I'm + + + align:start position:0% +We're not going to do it right away. I'm +going to I'm going to get him to answer + + align:start position:0% +going to I'm going to get him to answer + + + align:start position:0% +going to I'm going to get him to answer +the question a second time. + + align:start position:0% + + + + align:start position:0% + +Good idea. + + align:start position:0% + + + + align:start position:0% + +All right. And I think that'll work just + + align:start position:0% +All right. And I think that'll work just + + + align:start position:0% +All right. And I think that'll work just +great. + + align:start position:0% +great. + + + align:start position:0% +great. +And we're not going to give it away. + + align:start position:0% +And we're not going to give it away. + + + align:start position:0% +And we're not going to give it away. +Okay. So, set it down and we'll do the + + align:start position:0% +Okay. So, set it down and we'll do the + + + align:start position:0% +Okay. So, set it down and we'll do the +thing. Just Just drop it. + + align:start position:0% + + + + align:start position:0% + +Okay. So, let's do the uh let's do the + + align:start position:0% +Okay. So, let's do the uh let's do the + + + align:start position:0% +Okay. So, let's do the uh let's do the +quiz again. + + align:start position:0% +quiz again. + + + align:start position:0% +quiz again. +I want to see if any of you convinced + + align:start position:0% +I want to see if any of you convinced + + + align:start position:0% +I want to see if any of you convinced +your neighbor to change their vote. So, + + align:start position:0% +your neighbor to change their vote. So, + + + align:start position:0% +your neighbor to change their vote. So, +how many believe that it's going to be + + align:start position:0% +how many believe that it's going to be + + + align:start position:0% +how many believe that it's going to be +A? + + align:start position:0% +A? + + + align:start position:0% +A? +H one or two. Interesting. That count + + align:start position:0% +H one or two. Interesting. That count + + + align:start position:0% +H one or two. Interesting. That count +went down. How many believe it's going + + align:start position:0% +went down. How many believe it's going + + + align:start position:0% +went down. How many believe it's going +to be B? A lot of people went up. How + + align:start position:0% +to be B? A lot of people went up. How + + + align:start position:0% +to be B? A lot of people went up. How +many think it's going to be C? Okay. + + align:start position:0% +many think it's going to be C? Okay. + + + align:start position:0% +many think it's going to be C? Okay. +Okay, still a couple hold outs. Let's do + + align:start position:0% +Okay, still a couple hold outs. Let's do + + + align:start position:0% +Okay, still a couple hold outs. Let's do +the experiment. + + align:start position:0% + + + + align:start position:0% + +So guys in the booth, can you get a good + + align:start position:0% +So guys in the booth, can you get a good + + + align:start position:0% +So guys in the booth, can you get a good +shot of this? I hope I want this. So it + + align:start position:0% +shot of this? I hope I want this. So it + + + align:start position:0% +shot of this? I hope I want this. So it +p + + align:start position:0% +p + + + align:start position:0% +p +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +Move the chalk. Yep. + + align:start position:0% +Move the chalk. Yep. + + + align:start position:0% +Move the chalk. Yep. +And + + align:start position:0% +And + + + align:start position:0% +And +I'm going to have to catch it. All + + align:start position:0% +I'm going to have to catch it. All + + + align:start position:0% +I'm going to have to catch it. All +right. Let her rip. + + align:start position:0% + + + + align:start position:0% + +Which way? + + align:start position:0% +Which way? + + + align:start position:0% +Which way? +Yeah, let's do it again. + + align:start position:0% + + + + align:start position:0% + +Just make sure the guys in the booth got + + align:start position:0% +Just make sure the guys in the booth got + + + align:start position:0% +Just make sure the guys in the booth got +a good shot of this. Okay, once more. + + align:start position:0% + + + + align:start position:0% + +Pretty neat, huh? + + align:start position:0% +Pretty neat, huh? + + + align:start position:0% +Pretty neat, huh? +So, + + align:start position:0% + + + + align:start position:0% + +if you're if you're skiing + + align:start position:0% +if you're if you're skiing + + + align:start position:0% +if you're if you're skiing +downhill, you're going down the hill + + align:start position:0% +downhill, you're going down the hill + + + align:start position:0% +downhill, you're going down the hill +accelerating. + + align:start position:0% +accelerating. + + + align:start position:0% +accelerating. +Which way do you feel the forces on your + + align:start position:0% +Which way do you feel the forces on your + + + align:start position:0% +Which way do you feel the forces on your +body? + + align:start position:0% + + + + align:start position:0% + +You you feel forces pulling you down + + align:start position:0% +You you feel forces pulling you down + + + align:start position:0% +You you feel forces pulling you down +straight. You feel forces pulling you + + align:start position:0% +straight. You feel forces pulling you + + + align:start position:0% +straight. You feel forces pulling you +down the hill. field forces pulling you + + align:start position:0% +down the hill. field forces pulling you + + + align:start position:0% +down the hill. field forces pulling you +into the hill. + + align:start position:0% + + + + align:start position:0% + +So this is straightforward application + + align:start position:0% +So this is straightforward application + + + align:start position:0% +So this is straightforward application +of this. + + align:start position:0% +of this. + + + align:start position:0% +of this. +In order for this thing to have this, + + align:start position:0% +In order for this thing to have this, + + + align:start position:0% +In order for this thing to have this, +this slope of that liquid was parallel + + align:start position:0% +this slope of that liquid was parallel + + + align:start position:0% +this slope of that liquid was parallel +to the slope. + + align:start position:0% + + + + align:start position:0% + +So + + align:start position:0% + + + + align:start position:0% + +let's see if we I think I get my notes + + align:start position:0% +let's see if we I think I get my notes + + + align:start position:0% +let's see if we I think I get my notes +back out here. + + align:start position:0% + + + + align:start position:0% + +So let's do this just quickly do this + + align:start position:0% +So let's do this just quickly do this + + + align:start position:0% +So let's do this just quickly do this +problem rig sort of rigorously the way + + align:start position:0% +problem rig sort of rigorously the way + + + align:start position:0% +problem rig sort of rigorously the way +we would do it uh straight + + align:start position:0% +we would do it uh straight + + + align:start position:0% +we would do it uh straight +straightforward with accelerations and + + align:start position:0% +straightforward with accelerations and + + + align:start position:0% +straightforward with accelerations and +free body diagrams and so forth. We're + + align:start position:0% +free body diagrams and so forth. We're + + + align:start position:0% +free body diagrams and so forth. We're +going to have some normal force + + align:start position:0% +going to have some normal force + + + align:start position:0% +going to have some normal force +pushing up. There's no I said no + + align:start position:0% +pushing up. There's no I said no + + + align:start position:0% +pushing up. There's no I said no +friction. This thing's slippery surface. + + align:start position:0% +friction. This thing's slippery surface. + + + align:start position:0% +friction. This thing's slippery surface. +Just as if it was sliding down. Got to + + align:start position:0% +Just as if it was sliding down. Got to + + + align:start position:0% +Just as if it was sliding down. Got to +do do rollers in the classroom. Uh it's + + align:start position:0% +do do rollers in the classroom. Uh it's + + + align:start position:0% +do do rollers in the classroom. Uh it's +got an mg + + align:start position:0% + + + + align:start position:0% + +and there are no other external forces. + + align:start position:0% +and there are no other external forces. + + + align:start position:0% +and there are no other external forces. +Okay. And we know then that the + + align:start position:0% +Okay. And we know then that the + + + align:start position:0% +Okay. And we know then that the +summation of the external forces + + align:start position:0% +summation of the external forces + + + align:start position:0% +summation of the external forces +has got to be the + + align:start position:0% +has got to be the + + + align:start position:0% +has got to be the +mass times the acceleration. And I'm + + align:start position:0% +mass times the acceleration. And I'm + + + align:start position:0% +mass times the acceleration. And I'm +going to make this + + align:start position:0% +going to make this + + + align:start position:0% +going to make this +here. I'll call this point A in the + + align:start position:0% +here. I'll call this point A in the + + + align:start position:0% +here. I'll call this point A in the +center. And I'm going to make my + + align:start position:0% +center. And I'm going to make my + + + align:start position:0% +center. And I'm going to make my +inertial reference frame X down the + + align:start position:0% +inertial reference frame X down the + + + align:start position:0% +inertial reference frame X down the +hill, Y perpendicular to the hill. Okay. + + align:start position:0% +hill, Y perpendicular to the hill. Okay. + + + align:start position:0% +hill, Y perpendicular to the hill. Okay. +So the mass times the acceleration of A + + align:start position:0% +So the mass times the acceleration of A + + + align:start position:0% +So the mass times the acceleration of A +with respect to O is then equal and I + + align:start position:0% +with respect to O is then equal and I + + + align:start position:0% +with respect to O is then equal and I +can this is my then external forces. So + + align:start position:0% +can this is my then external forces. So + + + align:start position:0% +can this is my then external forces. So +this this is my X direction. + + align:start position:0% +this this is my X direction. + + + align:start position:0% +this this is my X direction. +So I'm going to break this G mg force + + align:start position:0% +So I'm going to break this G mg force + + + align:start position:0% +So I'm going to break this G mg force +force into two components. One down the + + align:start position:0% +force into two components. One down the + + + align:start position:0% +force into two components. One down the +hill. Guess I need an angle. + + align:start position:0% + + + + align:start position:0% + +Let's see. + + align:start position:0% + + + + align:start position:0% + +So if + + align:start position:0% +So if + + + align:start position:0% +So if +this is theta, + + align:start position:0% +this is theta, + + + align:start position:0% +this is theta, +then this is + + align:start position:0% + + + + align:start position:0% + +theta here. + + align:start position:0% + + + + align:start position:0% + +Okay. And the force down the hill is + + align:start position:0% +Okay. And the force down the hill is + + + align:start position:0% +Okay. And the force down the hill is +that component is mg + + align:start position:0% + + + + align:start position:0% + +sin theta. + + align:start position:0% +sin theta. + + + align:start position:0% +sin theta. +And the force this direction + + align:start position:0% +And the force this direction + + + align:start position:0% +And the force this direction +is then going to be + + align:start position:0% + + + + align:start position:0% + +and I'll just I'll give us some unit + + align:start position:0% +and I'll just I'll give us some unit + + + align:start position:0% +and I'll just I'll give us some unit +vectors here to keep things straight. + + align:start position:0% +vectors here to keep things straight. + + + align:start position:0% +vectors here to keep things straight. +This this force + + align:start position:0% +This this force + + + align:start position:0% +This this force +is minus mg + + align:start position:0% +is minus mg + + + align:start position:0% +is minus mg +cossine theta in the J hat direction. + + align:start position:0% +cossine theta in the J hat direction. + + + align:start position:0% +cossine theta in the J hat direction. +So the sum of the forces here + + align:start position:0% +So the sum of the forces here + + + align:start position:0% +So the sum of the forces here +all of them are + + align:start position:0% +all of them are + + + align:start position:0% +all of them are +mg + + align:start position:0% +mg + + + align:start position:0% +mg +sin theta ihat + + align:start position:0% +sin theta ihat + + + align:start position:0% +sin theta ihat +minus + + align:start position:0% +minus + + + align:start position:0% +minus +mg cosine theta + + align:start position:0% +mg cosine theta + + + align:start position:0% +mg cosine theta +j hat plus n in the jhat direction. So + + align:start position:0% +j hat plus n in the jhat direction. So + + + align:start position:0% +j hat plus n in the jhat direction. So +that's the total vector sum and that + + align:start position:0% +that's the total vector sum and that + + + align:start position:0% +that's the total vector sum and that +would be that's got to be equal to my + + align:start position:0% +would be that's got to be equal to my + + + align:start position:0% +would be that's got to be equal to my +mass times the acceleration of A with + + align:start position:0% +mass times the acceleration of A with + + + align:start position:0% +mass times the acceleration of A with +respect to O. + + align:start position:0% +respect to O. + + + align:start position:0% +respect to O. +And we know that's straight down the + + align:start position:0% +And we know that's straight down the + + + align:start position:0% +And we know that's straight down the +hill. So this is only going to be in the + + align:start position:0% +hill. So this is only going to be in the + + + align:start position:0% +hill. So this is only going to be in the +I. This one's only going to be in the + + align:start position:0% +I. This one's only going to be in the + + + align:start position:0% +I. This one's only going to be in the +ihat direction. We know the acceleration + + align:start position:0% +ihat direction. We know the acceleration + + + align:start position:0% +ihat direction. We know the acceleration +perpendicular to the hill has got to be + + align:start position:0% +perpendicular to the hill has got to be + + + align:start position:0% +perpendicular to the hill has got to be +zero. Okay. So if we just add up the + + align:start position:0% +zero. Okay. So if we just add up the + + + align:start position:0% +zero. Okay. So if we just add up the +components of this thing + + align:start position:0% +components of this thing + + + align:start position:0% +components of this thing +in the ihat direction just the x + + align:start position:0% +in the ihat direction just the x + + + align:start position:0% +in the ihat direction just the x +direction + + align:start position:0% +direction + + + align:start position:0% +direction +then + + align:start position:0% + + + + align:start position:0% + +I have only this term and that term and + + align:start position:0% +I have only this term and that term and + + + align:start position:0% +I have only this term and that term and +I find that the + + align:start position:0% + + + + align:start position:0% + +mg + + align:start position:0% +mg + + + align:start position:0% +mg +sin theta equals + + align:start position:0% + + + + align:start position:0% + +Right? And so + + align:start position:0% +Right? And so + + + align:start position:0% +Right? And so +the acceleration of A with respect to O + + align:start position:0% +the acceleration of A with respect to O + + + align:start position:0% +the acceleration of A with respect to O +is just g sin theta. + + align:start position:0% +is just g sin theta. + + + align:start position:0% +is just g sin theta. +Okay. Well, that's pretty trivial and it + + align:start position:0% +Okay. Well, that's pretty trivial and it + + + align:start position:0% +Okay. Well, that's pretty trivial and it +doesn't give us much insight + + align:start position:0% +doesn't give us much insight + + + align:start position:0% +doesn't give us much insight +about + + align:start position:0% + + + + align:start position:0% + +it. Actually, that doesn't give me much + + align:start position:0% +it. Actually, that doesn't give me much + + + align:start position:0% +it. Actually, that doesn't give me much +insight about why that's the answer. + + align:start position:0% +insight about why that's the answer. + + + align:start position:0% +insight about why that's the answer. +Okay. So actually this is a time when + + align:start position:0% +Okay. So actually this is a time when + + + align:start position:0% +Okay. So actually this is a time when +maybe thinking about a you're in that + + align:start position:0% +maybe thinking about a you're in that + + + align:start position:0% +maybe thinking about a you're in that +frame you're you're going down the hill + + align:start position:0% +frame you're you're going down the hill + + + align:start position:0% +frame you're you're going down the hill +you're skiing and you're now in an + + align:start position:0% +you're skiing and you're now in an + + + align:start position:0% +you're skiing and you're now in an +accelerating reference frame and you + + align:start position:0% +accelerating reference frame and you + + + align:start position:0% +accelerating reference frame and you +want to say I want to work from this + + align:start position:0% +want to say I want to work from this + + + align:start position:0% +want to say I want to work from this +frame what do I have to what fictitious + + align:start position:0% +frame what do I have to what fictitious + + + align:start position:0% +frame what do I have to what fictitious +force do I have to add to that free body + + align:start position:0% +force do I have to add to that free body + + + align:start position:0% +force do I have to add to that free body +diagram so I can account for my for my + + align:start position:0% +diagram so I can account for my for my + + + align:start position:0% +diagram so I can account for my for my +acceleration + + align:start position:0% + + + + align:start position:0% + +So remember this the fictitious force we + + align:start position:0% +So remember this the fictitious force we + + + align:start position:0% +So remember this the fictitious force we +want to deal deal with has to do with + + align:start position:0% +want to deal deal with has to do with + + + align:start position:0% +want to deal deal with has to do with +this guy. We're we're in the moving + + align:start position:0% +this guy. We're we're in the moving + + + align:start position:0% +this guy. We're we're in the moving +frame. We can't we can't judge this. + + align:start position:0% +frame. We can't we can't judge this. + + + align:start position:0% +frame. We can't we can't judge this. +We're just told that it exists and we + + align:start position:0% +We're just told that it exists and we + + + align:start position:0% +We're just told that it exists and we +need to correct for it. So we need a + + align:start position:0% +need to correct for it. So we need a + + + align:start position:0% +need to correct for it. So we need a +fictitious force that's minus m a with + + align:start position:0% +fictitious force that's minus m a with + + + align:start position:0% +fictitious force that's minus m a with +respect to o. So that would be minus mg + + align:start position:0% +respect to o. So that would be minus mg + + + align:start position:0% +respect to o. So that would be minus mg +sin theta and that would be in this + + align:start position:0% +sin theta and that would be in this + + + align:start position:0% +sin theta and that would be in this +direction. So dash lines here is my + + align:start position:0% +direction. So dash lines here is my + + + align:start position:0% +direction. So dash lines here is my +mg sin theta fictitious force + + align:start position:0% + + + + align:start position:0% + +in the other direction was the real + + align:start position:0% +in the other direction was the real + + + align:start position:0% +in the other direction was the real +force the component of gravity mg sin + + align:start position:0% +force the component of gravity mg sin + + + align:start position:0% +force the component of gravity mg sin +theta + + align:start position:0% +theta + + + align:start position:0% +theta +in this direction was my normal force + + align:start position:0% +in this direction was my normal force + + + align:start position:0% +in this direction was my normal force +and in this direction is my component of + + align:start position:0% +and in this direction is my component of + + + align:start position:0% +and in this direction is my component of +gravity that is my mg G cosine theta. + + align:start position:0% +gravity that is my mg G cosine theta. + + + align:start position:0% +gravity that is my mg G cosine theta. +Okay, + + align:start position:0% + + + + align:start position:0% + +it's a real force. So yeah, these these + + align:start position:0% +it's a real force. So yeah, these these + + + align:start position:0% +it's a real force. So yeah, these these +real forces and this fictitious force. + + align:start position:0% +real forces and this fictitious force. + + + align:start position:0% +real forces and this fictitious force. +But now we say the sum of these all + + align:start position:0% +But now we say the sum of these all + + + align:start position:0% +But now we say the sum of these all +these forces have to sum to zero. + + align:start position:0% +these forces have to sum to zero. + + + align:start position:0% +these forces have to sum to zero. +So we but look look what happens here. + + align:start position:0% +So we but look look what happens here. + + + align:start position:0% +So we but look look what happens here. +So what's the what ex what force do you + + align:start position:0% +So what's the what ex what force do you + + + align:start position:0% +So what's the what ex what force do you +feel + + align:start position:0% +feel + + + align:start position:0% +feel +in the reference frame? You're the skier + + align:start position:0% +in the reference frame? You're the skier + + + align:start position:0% +in the reference frame? You're the skier +going down the hill. What forces the net + + align:start position:0% +going down the hill. What forces the net + + + align:start position:0% +going down the hill. What forces the net +forces do you feel on you that are in + + align:start position:0% +forces do you feel on you that are in + + + align:start position:0% +forces do you feel on you that are in +the x direction down the hill + + align:start position:0% + + + + align:start position:0% + +zero + + align:start position:0% +zero + + + align:start position:0% +zero +it's exactly the reason I did that silly + + align:start position:0% +it's exactly the reason I did that silly + + + align:start position:0% +it's exactly the reason I did that silly +freef fall problem a minute ago when you + + align:start position:0% +freef fall problem a minute ago when you + + + align:start position:0% +freef fall problem a minute ago when you +drop something + + align:start position:0% +drop something + + + align:start position:0% +drop something +when you're weightless the scales are + + align:start position:0% +when you're weightless the scales are + + + align:start position:0% +when you're weightless the scales are +reading the cable broke in the elevator + + align:start position:0% +reading the cable broke in the elevator + + + align:start position:0% +reading the cable broke in the elevator +scales read zero the fictitious force + + align:start position:0% +scales read zero the fictitious force + + + align:start position:0% +scales read zero the fictitious force +was equal and opposite to the + + align:start position:0% +was equal and opposite to the + + + align:start position:0% +was equal and opposite to the +gravitational force you feel and the + + align:start position:0% +gravitational force you feel and the + + + align:start position:0% +gravitational force you feel and the +scales would show no force in the in the + + align:start position:0% +scales would show no force in the in the + + + align:start position:0% +scales would show no force in the in the +freef fall direction. In this case, + + align:start position:0% +freef fall direction. In this case, + + + align:start position:0% +freef fall direction. In this case, +you're not freef fall, but you're freef + + align:start position:0% +you're not freef fall, but you're freef + + + align:start position:0% +you're not freef fall, but you're freef +fall down a slope and the component down + + align:start position:0% +fall down a slope and the component down + + + align:start position:0% +fall down a slope and the component down +the slope, you have no net force in that + + align:start position:0% +the slope, you have no net force in that + + + align:start position:0% +the slope, you have no net force in that +direction. So, if you're + + align:start position:0% +direction. So, if you're + + + align:start position:0% +direction. So, if you're +in the reference frame of that moving + + align:start position:0% +in the reference frame of that moving + + + align:start position:0% +in the reference frame of that moving +cart, the only actual force you feel is + + align:start position:0% +cart, the only actual force you feel is + + + align:start position:0% +cart, the only actual force you feel is +N. + + align:start position:0% +N. + + + align:start position:0% +N. +You will feel a force on your feet + + align:start position:0% +You will feel a force on your feet + + + align:start position:0% +You will feel a force on your feet +equal to mg cosine theta. + + align:start position:0% +equal to mg cosine theta. + + + align:start position:0% +equal to mg cosine theta. +So if theta goes to 90° you're in freef + + align:start position:0% +So if theta goes to 90° you're in freef + + + align:start position:0% +So if theta goes to 90° you're in freef +fall and you feel it goes to zero. Theta + + align:start position:0% +fall and you feel it goes to zero. Theta + + + align:start position:0% +fall and you feel it goes to zero. Theta +is 0 degrees it's max and you would feel + + align:start position:0% +is 0 degrees it's max and you would feel + + + align:start position:0% +is 0 degrees it's max and you would feel +mg. Okay. So here just this this one + + align:start position:0% +mg. Okay. So here just this this one + + + align:start position:0% +mg. Okay. So here just this this one +this is an example for me where this + + align:start position:0% +this is an example for me where this + + + align:start position:0% +this is an example for me where this +notion of a fictitious force kind of + + align:start position:0% +notion of a fictitious force kind of + + + align:start position:0% +notion of a fictitious force kind of +helps me figure out what's going on. + + align:start position:0% + + + + align:start position:0% + +pretty amazing. + + align:start position:0% +pretty amazing. + + + align:start position:0% +pretty amazing. +Okay, so we're going to uh move on from + + align:start position:0% +Okay, so we're going to uh move on from + + + align:start position:0% +Okay, so we're going to uh move on from +this kind of discussion of fict + + align:start position:0% +this kind of discussion of fict + + + align:start position:0% +this kind of discussion of fict +fictitious forces and things. So let's + + align:start position:0% +fictitious forces and things. So let's + + + align:start position:0% +fictitious forces and things. So let's +it's been an hour. U we'll take a little + + align:start position:0% +it's been an hour. U we'll take a little + + + align:start position:0% +it's been an hour. U we'll take a little +break for a second. Also, if you got any + + align:start position:0% +break for a second. Also, if you got any + + + align:start position:0% +break for a second. Also, if you got any +questions about what we've covered up to + + align:start position:0% +questions about what we've covered up to + + + align:start position:0% +questions about what we've covered up to +this point, think about them and ask + + align:start position:0% +this point, think about them and ask + + + align:start position:0% +this point, think about them and ask +them in a minute. So just take a short + + align:start position:0% +them in a minute. So just take a short + + + align:start position:0% +them in a minute. So just take a short +break. So while I've been uh while + + align:start position:0% +break. So while I've been uh while + + + align:start position:0% +break. So while I've been uh while +you've been taking a break, a couple of + + align:start position:0% +you've been taking a break, a couple of + + + align:start position:0% +you've been taking a break, a couple of +people came up and asked questions. One + + align:start position:0% +people came up and asked questions. One + + + align:start position:0% +people came up and asked questions. One +of them was are fictitious forces real + + align:start position:0% +of them was are fictitious forces real + + + align:start position:0% +of them was are fictitious forces real +and the and the other is you know why + + align:start position:0% +and the and the other is you know why + + + align:start position:0% +and the and the other is you know why +does the water move? + + align:start position:0% +does the water move? + + + align:start position:0% +does the water move? +All right. + + align:start position:0% + + + + align:start position:0% + +So the answer to the answer to the first + + align:start position:0% +So the answer to the answer to the first + + + align:start position:0% +So the answer to the answer to the first +question + + align:start position:0% +question + + + align:start position:0% +question +if you want to be careful + + align:start position:0% +if you want to be careful + + + align:start position:0% +if you want to be careful +and do the problem rigorously + + align:start position:0% +and do the problem rigorously + + + align:start position:0% +and do the problem rigorously +don't mess with fictitious forces. + + align:start position:0% +don't mess with fictitious forces. + + + align:start position:0% +don't mess with fictitious forces. +The only + + align:start position:0% +The only + + + align:start position:0% +The only +real forces in the problem are the ones + + align:start position:0% +real forces in the problem are the ones + + + align:start position:0% +real forces in the problem are the ones +that you would put on a free body + + align:start position:0% +that you would put on a free body + + + align:start position:0% +that you would put on a free body +diagram such that that the sum of the + + align:start position:0% +diagram such that that the sum of the + + + align:start position:0% +diagram such that that the sum of the +external forces equals the mass times + + align:start position:0% +external forces equals the mass times + + + align:start position:0% +external forces equals the mass times +acceleration. And these forces are + + align:start position:0% +acceleration. And these forces are + + + align:start position:0% +acceleration. And these forces are +always real ones. They are gravity. They + + align:start position:0% +always real ones. They are gravity. They + + + align:start position:0% +always real ones. They are gravity. They +are normal forces. They're friction + + align:start position:0% +are normal forces. They're friction + + + align:start position:0% +are normal forces. They're friction +forces. They're spring forces. They're + + align:start position:0% +forces. They're spring forces. They're + + + align:start position:0% +forces. They're spring forces. They're +dash pot forces. They're all these + + align:start position:0% +dash pot forces. They're all these + + + align:start position:0% +dash pot forces. They're all these +mechanical things, but they're real + + align:start position:0% +mechanical things, but they're real + + + align:start position:0% +mechanical things, but they're real +forces. In the rod, that thing's + + align:start position:0% +forces. In the rod, that thing's + + + align:start position:0% +forces. In the rod, that thing's +spinning around. That rod since it's a + + align:start position:0% +spinning around. That rod since it's a + + + align:start position:0% +spinning around. That rod since it's a +rigid thing it can support bending. So + + align:start position:0% +rigid thing it can support bending. So + + + align:start position:0% +rigid thing it can support bending. So +it can put a she it has shear force. It + + align:start position:0% +it can put a she it has shear force. It + + + align:start position:0% +it can put a she it has shear force. It +can have axial forces. Those are real + + align:start position:0% +can have axial forces. Those are real + + + align:start position:0% +can have axial forces. Those are real +forces that it can put on the mass. + + align:start position:0% +forces that it can put on the mass. + + + align:start position:0% +forces that it can put on the mass. +Fictitious forces are not forces. They + + align:start position:0% +Fictitious forces are not forces. They + + + align:start position:0% +Fictitious forces are not forces. They +are minus a mass times a real what? + + align:start position:0% +are minus a mass times a real what? + + + align:start position:0% +are minus a mass times a real what? +Acceleration. + + align:start position:0% + + + + align:start position:0% + +So real forces real accelerations. We + + align:start position:0% +So real forces real accelerations. We + + + align:start position:0% +So real forces real accelerations. We +use this notion of a fictitious force as + + align:start position:0% +use this notion of a fictitious force as + + + align:start position:0% +use this notion of a fictitious force as +a convenience but it is a highly + + align:start position:0% +a convenience but it is a highly + + + align:start position:0% +a convenience but it is a highly +dangerous tool. + + align:start position:0% +dangerous tool. + + + align:start position:0% +dangerous tool. +Okay. But actually if once you get used + + align:start position:0% +Okay. But actually if once you get used + + + align:start position:0% +Okay. But actually if once you get used +to it a little bit it can give you some + + align:start position:0% +to it a little bit it can give you some + + + align:start position:0% +to it a little bit it can give you some +really quick insight. But I would always + + align:start position:0% +really quick insight. But I would always + + + align:start position:0% +really quick insight. But I would always +if I have doubts I'd always go back and + + align:start position:0% +if I have doubts I'd always go back and + + + align:start position:0% +if I have doubts I'd always go back and +just do the problem in a rigorous way + + align:start position:0% +just do the problem in a rigorous way + + + align:start position:0% +just do the problem in a rigorous way +and just check that your insight was + + align:start position:0% +and just check that your insight was + + + align:start position:0% +and just check that your insight was +right. But it could give you great + + align:start position:0% +right. But it could give you great + + + align:start position:0% +right. But it could give you great +insight to starting a problem. You know + + align:start position:0% +insight to starting a problem. You know + + + align:start position:0% +insight to starting a problem. You know +to expect a centrifugal term in your + + align:start position:0% +to expect a centrifugal term in your + + + align:start position:0% +to expect a centrifugal term in your +results. you know to expect a coriololis + + align:start position:0% +results. you know to expect a coriololis + + + align:start position:0% +results. you know to expect a coriololis +term. You just you know that they're + + align:start position:0% +term. You just you know that they're + + + align:start position:0% +term. You just you know that they're +going to be there because you you you + + align:start position:0% +going to be there because you you you + + + align:start position:0% +going to be there because you you you +sometimes you u + + align:start position:0% +sometimes you u + + + align:start position:0% +sometimes you u +you you know you feel them. The reason + + align:start position:0% +you you know you feel them. The reason + + + align:start position:0% +you you know you feel them. The reason +we like to use them is because you + + align:start position:0% +we like to use them is because you + + + align:start position:0% +we like to use them is because you +actually can feel them. + + align:start position:0% +actually can feel them. + + + align:start position:0% +actually can feel them. +They actually affect what you feel. + + align:start position:0% +They actually affect what you feel. + + + align:start position:0% +They actually affect what you feel. +So when you're in the uh + + align:start position:0% + + + + align:start position:0% + +when you're in that first in that first + + align:start position:0% +when you're in that first in that first + + + align:start position:0% +when you're in that first in that first +problem of the elevator problem the + + align:start position:0% +problem of the elevator problem the + + + align:start position:0% +problem of the elevator problem the +answer + + align:start position:0% + + + + align:start position:0% + +I didn't actually write it + + align:start position:0% +I didn't actually write it + + + align:start position:0% +I didn't actually write it +here it is the normal force that you + + align:start position:0% +here it is the normal force that you + + + align:start position:0% +here it is the normal force that you +feel that the scales weighs is 54g + + align:start position:0% +feel that the scales weighs is 54g + + + align:start position:0% +feel that the scales weighs is 54g +and it's the sum of gravity and that + + align:start position:0% +and it's the sum of gravity and that + + + align:start position:0% +and it's the sum of gravity and that +fictitious force + + align:start position:0% +fictitious force + + + align:start position:0% +fictitious force +It's mg plus m * a quart of a g. + + align:start position:0% +It's mg plus m * a quart of a g. + + + align:start position:0% +It's mg plus m * a quart of a g. +And so because you actually and and it's + + align:start position:0% +And so because you actually and and it's + + + align:start position:0% +And so because you actually and and it's +in this moving reference this + + align:start position:0% +in this moving reference this + + + align:start position:0% +in this moving reference this +accelerating reference frame inside an + + align:start position:0% +accelerating reference frame inside an + + + align:start position:0% +accelerating reference frame inside an +elevator where you can't directly + + align:start position:0% +elevator where you can't directly + + + align:start position:0% +elevator where you can't directly +measure the acceleration. All you can + + align:start position:0% +measure the acceleration. All you can + + + align:start position:0% +measure the acceleration. All you can +measure is the force + + align:start position:0% +measure is the force + + + align:start position:0% +measure is the force +but you you know what the acceleration + + align:start position:0% +but you you know what the acceleration + + + align:start position:0% +but you you know what the acceleration +is. It's given. So you stick it in as a + + align:start position:0% +is. It's given. So you stick it in as a + + + align:start position:0% +is. It's given. So you stick it in as a +fix and you find out that the real + + align:start position:0% +fix and you find out that the real + + + align:start position:0% +fix and you find out that the real +normal force that you measure actually + + align:start position:0% +normal force that you measure actually + + + align:start position:0% +normal force that you measure actually +has in it that piece that comes from the + + align:start position:0% +has in it that piece that comes from the + + + align:start position:0% +has in it that piece that comes from the +fictitious force. Okay. Why does the + + align:start position:0% +fictitious force. Okay. Why does the + + + align:start position:0% +fictitious force. Okay. Why does the +water move? Right? This this has to do + + align:start position:0% +water move? Right? This this has to do + + + align:start position:0% +water move? Right? This this has to do +this really the same discussion. The the + + align:start position:0% +this really the same discussion. The the + + + align:start position:0% +this really the same discussion. The the +fictitious force + + align:start position:0% +fictitious force + + + align:start position:0% +fictitious force +up the hill and the real force down the + + align:start position:0% +up the hill and the real force down the + + + align:start position:0% +up the hill and the real force down the +hill exactly cancel. + + align:start position:0% +hill exactly cancel. + + + align:start position:0% +hill exactly cancel. +If you could, if you're standing on + + align:start position:0% +If you could, if you're standing on + + + align:start position:0% +If you could, if you're standing on +scales that actually can measure side + + align:start position:0% +scales that actually can measure side + + + align:start position:0% +scales that actually can measure side +force as well as normal force, you + + align:start position:0% +force as well as normal force, you + + + align:start position:0% +force as well as normal force, you +standing on the scales, you would feel + + align:start position:0% +standing on the scales, you would feel + + + align:start position:0% +standing on the scales, you would feel +no side forces up and down the hill. + + align:start position:0% +no side forces up and down the hill. + + + align:start position:0% +no side forces up and down the hill. +None. + + align:start position:0% +None. + + + align:start position:0% +None. +You measure a normal force and the + + align:start position:0% +You measure a normal force and the + + + align:start position:0% +You measure a normal force and the +normal force you measure will be mg + + align:start position:0% +normal force you measure will be mg + + + align:start position:0% +normal force you measure will be mg +cosine theta. + + align:start position:0% +cosine theta. + + + align:start position:0% +cosine theta. +So the force on any + + align:start position:0% +So the force on any + + + align:start position:0% +So the force on any +you know any object in that accelerating + + align:start position:0% +you know any object in that accelerating + + + align:start position:0% +you know any object in that accelerating +reference frame it essentially thinks + + align:start position:0% +reference frame it essentially thinks + + + align:start position:0% +reference frame it essentially thinks +that all forces are perpendic that it + + align:start position:0% +that all forces are perpendic that it + + + align:start position:0% +that all forces are perpendic that it +that you feel in that reference frame + + align:start position:0% +that you feel in that reference frame + + + align:start position:0% +that you feel in that reference frame +are perpendicular to the hill. + + align:start position:0% +are perpendicular to the hill. + + + align:start position:0% +are perpendicular to the hill. +So if why does water seek level + + align:start position:0% +So if why does water seek level + + + align:start position:0% +So if why does water seek level +because the force gravity is down and + + align:start position:0% +because the force gravity is down and + + + align:start position:0% +because the force gravity is down and +the surface of the water goes + + align:start position:0% +the surface of the water goes + + + align:start position:0% +the surface of the water goes +perpendicular to the gravitational + + align:start position:0% +perpendicular to the gravitational + + + align:start position:0% +perpendicular to the gravitational +force. That's just the nature of fluids. + + align:start position:0% +force. That's just the nature of fluids. + + + align:start position:0% +force. That's just the nature of fluids. +So if the force on all those fluid + + align:start position:0% +So if the force on all those fluid + + + align:start position:0% +So if the force on all those fluid +particles is is this angle, what's the + + align:start position:0% +particles is is this angle, what's the + + + align:start position:0% +particles is is this angle, what's the +fluid level going to do? So that the + + align:start position:0% +fluid level going to do? So that the + + + align:start position:0% +fluid level going to do? So that the +pressure on the surface is equal + + align:start position:0% +pressure on the surface is equal + + + align:start position:0% +pressure on the surface is equal +everywhere. And if you go a foot down, + + align:start position:0% +everywhere. And if you go a foot down, + + + align:start position:0% +everywhere. And if you go a foot down, +you'd have equal pressure everywhere in + + align:start position:0% +you'd have equal pressure everywhere in + + + align:start position:0% +you'd have equal pressure everywhere in +the fluid. + + align:start position:0% +the fluid. + + + align:start position:0% +the fluid. +So it it just see what + + align:start position:0% + + + + align:start position:0% + +so the water moves so that its surface + + align:start position:0% +so the water moves so that its surface + + + align:start position:0% +so the water moves so that its surface +will be perpendicular to what it thinks + + align:start position:0% +will be perpendicular to what it thinks + + + align:start position:0% +will be perpendicular to what it thinks +is it thinks that this is kind of being + + align:start position:0% +is it thinks that this is kind of being + + + align:start position:0% +is it thinks that this is kind of being +the local gravity. The local gravity is + + align:start position:0% +the local gravity. The local gravity is + + + align:start position:0% +the local gravity. The local gravity is +pointed in that direction. So the + + align:start position:0% +pointed in that direction. So the + + + align:start position:0% +pointed in that direction. So the +surface level seeks that level. + + align:start position:0% +surface level seeks that level. + + + align:start position:0% +surface level seeks that level. +If somebody else can say it better than + + align:start position:0% +If somebody else can say it better than + + + align:start position:0% +If somebody else can say it better than +that Tom Dave Matt anybody + + align:start position:0% +that Tom Dave Matt anybody + + + align:start position:0% +that Tom Dave Matt anybody +these are + + align:start position:0% + + + + align:start position:0% + +Yeah. + + align:start position:0% +Yeah. + + + align:start position:0% +Yeah. +Yeah. + + align:start position:0% + + + + align:start position:0% + +Well, + + align:start position:0% + + + + align:start position:0% + +yeah. You're as if you you're on the + + align:start position:0% +yeah. You're as if you you're on the + + + align:start position:0% +yeah. You're as if you you're on the +body and you're trying to sum up all the + + align:start position:0% +body and you're trying to sum up all the + + + align:start position:0% +body and you're trying to sum up all the +forces you feel and accounting also for + + align:start position:0% +forces you feel and accounting also for + + + align:start position:0% +forces you feel and accounting also for +the fact that this is accelerating. And + + align:start position:0% +the fact that this is accelerating. And + + + align:start position:0% +the fact that this is accelerating. And +the fix it force is this fictitious + + align:start position:0% +the fix it force is this fictitious + + + align:start position:0% +the fix it force is this fictitious +force that's due to the body's + + align:start position:0% +force that's due to the body's + + + align:start position:0% +force that's due to the body's +acceleration. You have to know that + + align:start position:0% +acceleration. You have to know that + + + align:start position:0% +acceleration. You have to know that +you're accelerating to be able to put + + align:start position:0% +you're accelerating to be able to put + + + align:start position:0% +you're accelerating to be able to put +this term in. + + align:start position:0% +this term in. + + + align:start position:0% +this term in. +And all it comes from this equation + + align:start position:0% +And all it comes from this equation + + + align:start position:0% +And all it comes from this equation +gener thinking of this as a generic + + align:start position:0% +gener thinking of this as a generic + + + align:start position:0% +gener thinking of this as a generic +equation by taking this term and just + + align:start position:0% +equation by taking this term and just + + + align:start position:0% +equation by taking this term and just +moving it to this side and setting + + align:start position:0% +moving it to this side and setting + + + align:start position:0% +moving it to this side and setting +everything equal to zero. + + align:start position:0% + + + + align:start position:0% + +Lots of puzzlemen around this. This + + align:start position:0% +Lots of puzzlemen around this. This + + + align:start position:0% +Lots of puzzlemen around this. This +what happens if you make the angle of + + align:start position:0% +what happens if you make the angle of + + + align:start position:0% +what happens if you make the angle of +the ram like very steep + + align:start position:0% +the ram like very steep + + + align:start position:0% +the ram like very steep +very steep. So if it goes to 90° + + align:start position:0% +very steep. So if it goes to 90° + + + align:start position:0% +very steep. So if it goes to 90° +you're in freef fall you will measure + + align:start position:0% +you're in freef fall you will measure + + + align:start position:0% +you're in freef fall you will measure +the + + align:start position:0% +the + + + align:start position:0% +the +this cosine theta goes to zero and goes + + align:start position:0% +this cosine theta goes to zero and goes + + + align:start position:0% +this cosine theta goes to zero and goes +to zero. + + align:start position:0% +to zero. + + + align:start position:0% +to zero. +This term stays the same. This goes to + + align:start position:0% +This term stays the same. This goes to + + + align:start position:0% +This term stays the same. This goes to +mg that way. This goes mg that way. and + + align:start position:0% +mg that way. This goes mg that way. and + + + align:start position:0% +mg that way. This goes mg that way. and +it's in equilibrium and both + + align:start position:0% + + + + align:start position:0% + +then you're going to have very very + + align:start position:0% +then you're going to have very very + + + align:start position:0% +then you're going to have very very +small normal force. + + align:start position:0% +small normal force. + + + align:start position:0% +small normal force. +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +Okay. + + align:start position:0% + + + + align:start position:0% + +I couldn't hear the last comment. The + + align:start position:0% +I couldn't hear the last comment. The + + + align:start position:0% +I couldn't hear the last comment. The +water wouldn't go all the way to the + + align:start position:0% +water wouldn't go all the way to the + + + align:start position:0% +water wouldn't go all the way to the +side. + + align:start position:0% + + + + align:start position:0% + +Well, you know, the water unfortunately, + + align:start position:0% +Well, you know, the water unfortunately, + + + align:start position:0% +Well, you know, the water unfortunately, +I mean, it with the tiniest little bit + + align:start position:0% +I mean, it with the tiniest little bit + + + align:start position:0% +I mean, it with the tiniest little bit +of normal uh acceler normal force here, + + align:start position:0% +of normal uh acceler normal force here, + + + align:start position:0% +of normal uh acceler normal force here, +the water will seek that level, but when + + align:start position:0% +the water will seek that level, but when + + + align:start position:0% +the water will seek that level, but when +it gets to zero, it's kind of all + + align:start position:0% +it gets to zero, it's kind of all + + + align:start position:0% +it gets to zero, it's kind of all +the water is just going to be in freef + + align:start position:0% +the water is just going to be in freef + + + align:start position:0% +the water is just going to be in freef +fall. It's going to form surface tension + + align:start position:0% +fall. It's going to form surface tension + + + align:start position:0% +fall. It's going to form surface tension +takes over, right? Yeah. This argument + + align:start position:0% +takes over, right? Yeah. This argument + + + align:start position:0% +takes over, right? Yeah. This argument +that equal pressure is the same as it + + align:start position:0% +that equal pressure is the same as it + + + align:start position:0% +that equal pressure is the same as it +was just on a flat surface accelerating. + + align:start position:0% + + + + align:start position:0% + +Okay. If you were ah good question. If + + align:start position:0% +Okay. If you were ah good question. If + + + align:start position:0% +Okay. If you were ah good question. If +you're on a flat surface accelerating, + + align:start position:0% +you're on a flat surface accelerating, + + + align:start position:0% +you're on a flat surface accelerating, +if you were accelerating and this cart + + align:start position:0% +if you were accelerating and this cart + + + align:start position:0% +if you were accelerating and this cart +accelerates with a fluid on it and it's + + align:start position:0% +accelerates with a fluid on it and it's + + + align:start position:0% +accelerates with a fluid on it and it's +accelerating in that direction, + + align:start position:0% +accelerating in that direction, + + + align:start position:0% +accelerating in that direction, +what would the surface of the liquid do? + + align:start position:0% + + + + align:start position:0% + +stay level or change? + + align:start position:0% +stay level or change? + + + align:start position:0% +stay level or change? +Okay. Does it slope back or does it + + align:start position:0% +Okay. Does it slope back or does it + + + align:start position:0% +Okay. Does it slope back or does it +slope forward? I'm accelerating in that + + align:start position:0% +slope forward? I'm accelerating in that + + + align:start position:0% +slope forward? I'm accelerating in that +direction. + + align:start position:0% +direction. + + + align:start position:0% +direction. +There's a centrifugal + + align:start position:0% +There's a centrifugal + + + align:start position:0% +There's a centrifugal +not a fictitious force pushing back on + + align:start position:0% +not a fictitious force pushing back on + + + align:start position:0% +not a fictitious force pushing back on +it pushes it makes it pile up at the + + align:start position:0% +it pushes it makes it pile up at the + + + align:start position:0% +it pushes it makes it pile up at the +back. + + align:start position:0% +back. + + + align:start position:0% +back. +Okay, one more. + + align:start position:0% +Okay, one more. + + + align:start position:0% +Okay, one more. +You're in the elevator. You're + + align:start position:0% +You're in the elevator. You're + + + align:start position:0% +You're in the elevator. You're +accelerating a quarter of a g. + + align:start position:0% +accelerating a quarter of a g. + + + align:start position:0% +accelerating a quarter of a g. +You feel the scales tells you weigh, you + + align:start position:0% +You feel the scales tells you weigh, you + + + align:start position:0% +You feel the scales tells you weigh, you +know, 25% more than you used to. And you + + align:start position:0% +know, 25% more than you used to. And you + + + align:start position:0% +know, 25% more than you used to. And you +have a pendulum. And on before the + + align:start position:0% +have a pendulum. And on before the + + + align:start position:0% +have a pendulum. And on before the +elevator starts, it's got a 1se second + + align:start position:0% +elevator starts, it's got a 1se second + + + align:start position:0% +elevator starts, it's got a 1se second +natural period. + + align:start position:0% +natural period. + + + align:start position:0% +natural period. +And now the elevator gets going, does + + align:start position:0% +And now the elevator gets going, does + + + align:start position:0% +And now the elevator gets going, does +the period change? + + align:start position:0% +the period change? + + + align:start position:0% +the period change? +Higher or lower? + + align:start position:0% + + + + align:start position:0% + +Okay. The So the natural frequency of + + align:start position:0% +Okay. The So the natural frequency of + + + align:start position:0% +Okay. The So the natural frequency of +the pendulum, simple pendulum, square + + align:start position:0% +the pendulum, simple pendulum, square + + + align:start position:0% +the pendulum, simple pendulum, square +root of G over L. What do you what do + + align:start position:0% +root of G over L. What do you what do + + + align:start position:0% +root of G over L. What do you what do +you guess that the natural frequency is + + align:start position:0% +you guess that the natural frequency is + + + align:start position:0% +you guess that the natural frequency is +if you're going up at a quarter of a G? + + align:start position:0% + + + + align:start position:0% + +Say again. + + align:start position:0% + + + + align:start position:0% + +as if you have a higher or lower + + align:start position:0% +as if you have a higher or lower + + + align:start position:0% +as if you have a higher or lower +acceleration of gravity around. + + align:start position:0% +acceleration of gravity around. + + + align:start position:0% +acceleration of gravity around. +It's like you have a higher + + align:start position:0% +It's like you have a higher + + + align:start position:0% +It's like you have a higher +gravitational force is what you think + + align:start position:0% +gravitational force is what you think + + + align:start position:0% +gravitational force is what you think +you're feeling. Is that going to make + + align:start position:0% +you're feeling. Is that going to make + + + align:start position:0% +you're feeling. Is that going to make +put make the tension in this string + + align:start position:0% +put make the tension in this string + + + align:start position:0% +put make the tension in this string +higher? Is that going to make the weight + + align:start position:0% +higher? Is that going to make the weight + + + align:start position:0% +higher? Is that going to make the weight +of the pendulum feel greater? Yeah. By + + align:start position:0% +of the pendulum feel greater? Yeah. By + + + align:start position:0% +of the pendulum feel greater? Yeah. By +five for fours. And you'll find out you + + align:start position:0% +five for fours. And you'll find out you + + + align:start position:0% +five for fours. And you'll find out you +work out. It gets kind of messy to prove + + align:start position:0% +work out. It gets kind of messy to prove + + + align:start position:0% +work out. It gets kind of messy to prove +this uh rigorously, but it's going to + + align:start position:0% +this uh rigorously, but it's going to + + + align:start position:0% +this uh rigorously, but it's going to +look something like the square root of + + align:start position:0% +look something like the square root of + + + align:start position:0% +look something like the square root of +54 G over L. Okay. Okay. + + align:start position:0% + + + + align:start position:0% + +All right. We got a little time left. I + + align:start position:0% +All right. We got a little time left. I + + + align:start position:0% +All right. We got a little time left. I +might not be able to completely finish + + align:start position:0% +might not be able to completely finish + + + align:start position:0% +might not be able to completely finish +this, but I do want to show you + + align:start position:0% +this, but I do want to show you + + + align:start position:0% +this, but I do want to show you +something. + + align:start position:0% +something. + + + align:start position:0% +something. +You had a + + align:start position:0% + + + + align:start position:0% + +Hold it up so they can see. It + + align:start position:0% + + + + align:start position:0% + +gets pretty violent, doesn't it? Pass it + + align:start position:0% +gets pretty violent, doesn't it? Pass it + + + align:start position:0% +gets pretty violent, doesn't it? Pass it +around. + + align:start position:0% + + + + align:start position:0% + +Okay. This this thing is shaking like + + align:start position:0% +Okay. This this thing is shaking like + + + align:start position:0% +Okay. This this thing is shaking like +crazy. + + align:start position:0% + + + + align:start position:0% + +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +All right. I'll let you and I'll uh + + align:start position:0% + + + + align:start position:0% + +All right. In the absence of external + + align:start position:0% +All right. In the absence of external + + + align:start position:0% +All right. In the absence of external +forces, what can you say about the + + align:start position:0% +forces, what can you say about the + + + align:start position:0% +forces, what can you say about the +motion of its center of gravity? Do you + + align:start position:0% +motion of its center of gravity? Do you + + + align:start position:0% +motion of its center of gravity? Do you +think in the at least this direction? + + align:start position:0% +think in the at least this direction? + + + align:start position:0% +think in the at least this direction? +can't move right in the up up and down + + align:start position:0% +can't move right in the up up and down + + + align:start position:0% +can't move right in the up up and down +direction. It uh uh the center of + + align:start position:0% +direction. It uh uh the center of + + + align:start position:0% +direction. It uh uh the center of +gravity does move because I'm putting a + + align:start position:0% +gravity does move because I'm putting a + + + align:start position:0% +gravity does move because I'm putting a +force on it through the cord. Okay, this + + align:start position:0% +force on it through the cord. Okay, this + + + align:start position:0% +force on it through the cord. Okay, this +is there's this has a relation to a + + align:start position:0% +is there's this has a relation to a + + + align:start position:0% +is there's this has a relation to a +problem that you were had on problem set + + align:start position:0% +problem that you were had on problem set + + + align:start position:0% +problem that you were had on problem set +two. + + align:start position:0% +two. + + + align:start position:0% +two. +I wanted to go back and talk about it a + + align:start position:0% +I wanted to go back and talk about it a + + + align:start position:0% +I wanted to go back and talk about it a +little bit because + + align:start position:0% + + + + align:start position:0% + +this is that thing with a track in it + + align:start position:0% +this is that thing with a track in it + + + align:start position:0% +this is that thing with a track in it +and has a roller going around and it's + + align:start position:0% +and has a roller going around and it's + + + align:start position:0% +and has a roller going around and it's +going around at constant speed. And this + + align:start position:0% +going around at constant speed. And this + + + align:start position:0% +going around at constant speed. And this +has mass m this has mass the outside + + align:start position:0% +has mass m this has mass the outside + + + align:start position:0% +has mass m this has mass the outside +thing is just the mass of this block. + + align:start position:0% +thing is just the mass of this block. + + + align:start position:0% +thing is just the mass of this block. +Okay? And this there's an internal donut + + align:start position:0% +Okay? And this there's an internal donut + + + align:start position:0% +Okay? And this there's an internal donut +in here, a toid. And this mass is made + + align:start position:0% +in here, a toid. And this mass is made + + + align:start position:0% +in here, a toid. And this mass is made +to go running around around inside. And + + align:start position:0% +to go running around around inside. And + + + align:start position:0% +to go running around around inside. And +you were asked to figure out the + + align:start position:0% +you were asked to figure out the + + + align:start position:0% +you were asked to figure out the +acceleration of that guy. But this + + align:start position:0% +acceleration of that guy. But this + + + align:start position:0% +acceleration of that guy. But this +thing's on wheels. + + align:start position:0% + + + + align:start position:0% + +Now + + align:start position:0% +Now + + + align:start position:0% +Now +this problem and I I apologize for for + + align:start position:0% +this problem and I I apologize for for + + + align:start position:0% +this problem and I I apologize for for +posing this problem the way I did. I + + align:start position:0% +posing this problem the way I did. I + + + align:start position:0% +posing this problem the way I did. I +should have posed it in the following + + align:start position:0% +should have posed it in the following + + + align:start position:0% +should have posed it in the following +sense following way. These two problems + + align:start position:0% +sense following way. These two problems + + + align:start position:0% +sense following way. These two problems +are really equal to one another. + + align:start position:0% +are really equal to one another. + + + align:start position:0% +are really equal to one another. +I have a rod. I have a mass on the end. + + align:start position:0% +I have a rod. I have a mass on the end. + + + align:start position:0% +I have a rod. I have a mass on the end. +This radius here we said was E. This + + align:start position:0% +This radius here we said was E. This + + + align:start position:0% +This radius here we said was E. This +radius is E. The mass is the same. It's + + align:start position:0% +radius is E. The mass is the same. It's + + + align:start position:0% +radius is E. The mass is the same. It's +m. This was going around at + + align:start position:0% +m. This was going around at + + + align:start position:0% +m. This was going around at +omega. This is going around at omega. + + align:start position:0% +omega. This is going around at omega. + + + align:start position:0% +omega. This is going around at omega. +This is on wheels. Exactly. These two + + align:start position:0% +This is on wheels. Exactly. These two + + + align:start position:0% +This is on wheels. Exactly. These two +problems are + + align:start position:0% +problems are + + + align:start position:0% +problems are +identical because if the geometry is the + + align:start position:0% +identical because if the geometry is the + + + align:start position:0% +identical because if the geometry is the +same, the rotation rates the same, the + + align:start position:0% +same, the rotation rates the same, the + + + align:start position:0% +same, the rotation rates the same, the +masses are the same, the acceleration of + + align:start position:0% +masses are the same, the acceleration of + + + align:start position:0% +masses are the same, the acceleration of +this bead here, this roller is the same + + align:start position:0% +this bead here, this roller is the same + + + align:start position:0% +this bead here, this roller is the same +in this problem as it is in that + + align:start position:0% +in this problem as it is in that + + + align:start position:0% +in this problem as it is in that +problem. just that this problem is much + + align:start position:0% +problem. just that this problem is much + + + align:start position:0% +problem. just that this problem is much +easier to figure out the forces. This + + align:start position:0% +easier to figure out the forces. This + + + align:start position:0% +easier to figure out the forces. This +turned out to be kind of nasty. And I + + align:start position:0% +turned out to be kind of nasty. And I + + + align:start position:0% +turned out to be kind of nasty. And I +said last time that the solution to the + + align:start position:0% +said last time that the solution to the + + + align:start position:0% +said last time that the solution to the +B part, which is the normal force that + + align:start position:0% +B part, which is the normal force that + + + align:start position:0% +B part, which is the normal force that +this is put on this roller, I said that + + align:start position:0% +this is put on this roller, I said that + + + align:start position:0% +this is put on this roller, I said that +answer was wrong. I actually am wrong + + align:start position:0% +answer was wrong. I actually am wrong + + + align:start position:0% +answer was wrong. I actually am wrong +about that. I I was thinking of a + + align:start position:0% +about that. I I was thinking of a + + + align:start position:0% +about that. I I was thinking of a +different answer. I was thinking of this + + align:start position:0% +different answer. I was thinking of this + + + align:start position:0% +different answer. I was thinking of this +problem. + + align:start position:0% +problem. + + + align:start position:0% +problem. +uh the pro the answer that was given the + + align:start position:0% +uh the pro the answer that was given the + + + align:start position:0% +uh the pro the answer that was given the +normal force that is by the track places + + align:start position:0% +normal force that is by the track places + + + align:start position:0% +normal force that is by the track places +on the roller or the vice versa is + + align:start position:0% +on the roller or the vice versa is + + + align:start position:0% +on the roller or the vice versa is +actually what was given is correct. It + + align:start position:0% +actually what was given is correct. It + + + align:start position:0% +actually what was given is correct. It +wasn't what I actually was seeking when + + align:start position:0% +wasn't what I actually was seeking when + + + align:start position:0% +wasn't what I actually was seeking when +I wrote the problem. Sometimes you know + + align:start position:0% +I wrote the problem. Sometimes you know + + + align:start position:0% +I wrote the problem. Sometimes you know +you when you're making up problems you + + align:start position:0% +you when you're making up problems you + + + align:start position:0% +you when you're making up problems you +have an end result in mind and then you + + align:start position:0% +have an end result in mind and then you + + + align:start position:0% +have an end result in mind and then you +wrote it wrong. I wrote it wrong. So + + align:start position:0% +wrote it wrong. I wrote it wrong. So + + + align:start position:0% +wrote it wrong. I wrote it wrong. So +let's do this problem + + align:start position:0% +let's do this problem + + + align:start position:0% +let's do this problem +and I want to do I want this is partly + + align:start position:0% +and I want to do I want this is partly + + + align:start position:0% +and I want to do I want this is partly +re uh to review a couple of things for + + align:start position:0% +re uh to review a couple of things for + + + align:start position:0% +re uh to review a couple of things for +you. So I want to find the what I really + + align:start position:0% +you. So I want to find the what I really + + + align:start position:0% +you. So I want to find the what I really +want is I want to find + + align:start position:0% +want is I want to find + + + align:start position:0% +want is I want to find +the equation of motion + + align:start position:0% +the equation of motion + + + align:start position:0% +the equation of motion +in + + align:start position:0% + + + + align:start position:0% + +how do I draw my + + align:start position:0% + + + + align:start position:0% + +so here's my x yz inertial reference + + align:start position:0% +so here's my x yz inertial reference + + + align:start position:0% +so here's my x yz inertial reference +frame. I just lined it up here with the + + align:start position:0% +frame. I just lined it up here with the + + + align:start position:0% +frame. I just lined it up here with the +know the center of this thing to start + + align:start position:0% +know the center of this thing to start + + + align:start position:0% +know the center of this thing to start +with. Doesn't really matter. So I want + + align:start position:0% +with. Doesn't really matter. So I want + + + align:start position:0% +with. Doesn't really matter. So I want +to find an equation of motion in the x + + align:start position:0% +to find an equation of motion in the x + + + align:start position:0% +to find an equation of motion in the x +direction. + + align:start position:0% + + + + align:start position:0% + +And we don't have time to do this whole + + align:start position:0% +And we don't have time to do this whole + + + align:start position:0% +And we don't have time to do this whole +problem here. So I'm going to do the + + align:start position:0% +problem here. So I'm going to do the + + + align:start position:0% +problem here. So I'm going to do the +first piece of it is + + align:start position:0% +first piece of it is + + + align:start position:0% +first piece of it is +just to give you some review and + + align:start position:0% +just to give you some review and + + + align:start position:0% +just to give you some review and +exercise in figuring out degrees of + + align:start position:0% +exercise in figuring out degrees of + + + align:start position:0% +exercise in figuring out degrees of +freedom. How many I I I'm implying that + + align:start position:0% +freedom. How many I I I'm implying that + + + align:start position:0% +freedom. How many I I I'm implying that +I I can write one equation. It may take + + align:start position:0% +I I can write one equation. It may take + + + align:start position:0% +I I can write one equation. It may take +more than that. So the number of degrees + + align:start position:0% +more than that. So the number of degrees + + + align:start position:0% +more than that. So the number of degrees +of freedom we said is equal to the + + align:start position:0% +of freedom we said is equal to the + + + align:start position:0% +of freedom we said is equal to the +number of + + align:start position:0% +number of + + + align:start position:0% +number of +required + + align:start position:0% +required + + + align:start position:0% +required +can't write today + + align:start position:0% + + + + align:start position:0% + +independent + + align:start position:0% + + + + align:start position:0% + +coordinates. + + align:start position:0% +coordinates. + + + align:start position:0% +coordinates. +So the number of coordinates required to + + align:start position:0% +So the number of coordinates required to + + + align:start position:0% +So the number of coordinates required to +completely describe the motion and we + + align:start position:0% +completely describe the motion and we + + + align:start position:0% +completely describe the motion and we +came up with a little expression for + + align:start position:0% +came up with a little expression for + + + align:start position:0% +came up with a little expression for +that. It's six times the number of rigid + + align:start position:0% +that. It's six times the number of rigid + + + align:start position:0% +that. It's six times the number of rigid +bodies plus 3 * the number of particles. + + align:start position:0% +bodies plus 3 * the number of particles. + + + align:start position:0% +bodies plus 3 * the number of particles. +So this is rigid bodies. + + align:start position:0% +So this is rigid bodies. + + + align:start position:0% +So this is rigid bodies. +This is particles + + align:start position:0% + + + + align:start position:0% + +minus + + align:start position:0% +minus + + + align:start position:0% +minus +C and these are the constraints. + + align:start position:0% + + + + align:start position:0% + +So, let's figure that out for this + + align:start position:0% +So, let's figure that out for this + + + align:start position:0% +So, let's figure that out for this +problem. + + align:start position:0% +problem. + + + align:start position:0% +problem. +Oops. + + align:start position:0% + + + + align:start position:0% + +How many constraints? It's just a quick + + align:start position:0% +How many constraints? It's just a quick + + + align:start position:0% +How many constraints? It's just a quick +practice. + + align:start position:0% +practice. + + + align:start position:0% +practice. +So constraints and I'm going to start + + align:start position:0% +So constraints and I'm going to start + + + align:start position:0% +So constraints and I'm going to start +off with on + + align:start position:0% +off with on + + + align:start position:0% +off with on +the main block. Okay. So + + align:start position:0% +the main block. Okay. So + + + align:start position:0% +the main block. Okay. So +there's on the main block there's no Y + + align:start position:0% +there's on the main block there's no Y + + + align:start position:0% +there's on the main block there's no Y +motion. There's no Z motion. These + + align:start position:0% +motion. There's no Z motion. These + + + align:start position:0% +motion. There's no Z motion. These +rollers don't let it come in or out. So + + align:start position:0% + + + + align:start position:0% + +no Y or Z motion. + + align:start position:0% + + + + align:start position:0% + +So that's two constraints. + + align:start position:0% +So that's two constraints. + + + align:start position:0% +So that's two constraints. +Okay. What about rotations on the main + + align:start position:0% +Okay. What about rotations on the main + + + align:start position:0% +Okay. What about rotations on the main +block? How many constraints are we + + align:start position:0% +block? How many constraints are we + + + align:start position:0% +block? How many constraints are we +assuming here? + + align:start position:0% +assuming here? + + + align:start position:0% +assuming here? +Three. We're not allowing it to roll in + + align:start position:0% +Three. We're not allowing it to roll in + + + align:start position:0% +Three. We're not allowing it to roll in +the X, the Y, or the Z. + + align:start position:0% + + + + align:start position:0% + +So there's three more constraints. + + align:start position:0% +So there's three more constraints. + + + align:start position:0% +So there's three more constraints. +And now on the little mass. + + align:start position:0% + + + + align:start position:0% + +Okay, on the little mass there's no Z + + align:start position:0% +Okay, on the little mass there's no Z + + + align:start position:0% +Okay, on the little mass there's no Z +motion. That's out of the board. + + align:start position:0% + + + + align:start position:0% + +That's one more constraint. + + align:start position:0% +That's one more constraint. + + + align:start position:0% +That's one more constraint. +And then + + align:start position:0% + + + + align:start position:0% + +omega t + + align:start position:0% +omega t + + + align:start position:0% +omega t +is the angle that this thing that's + + align:start position:0% +is the angle that this thing that's + + + align:start position:0% +is the angle that this thing that's +theta. + + align:start position:0% +theta. + + + align:start position:0% +theta. +This is specified. + + align:start position:0% + + + + align:start position:0% + +It's a given in the problem. It's not + + align:start position:0% +It's a given in the problem. It's not + + + align:start position:0% +It's a given in the problem. It's not +unknown. It's just that's what's going + + align:start position:0% +unknown. It's just that's what's going + + + align:start position:0% +unknown. It's just that's what's going +that's what makes this thing do its + + align:start position:0% +that's what makes this thing do its + + + align:start position:0% +that's what makes this thing do its +thing. It's going round and round. And + + align:start position:0% +thing. It's going round and round. And + + + align:start position:0% +thing. It's going round and round. And +so this is not an unknown. And therefore + + align:start position:0% +so this is not an unknown. And therefore + + + align:start position:0% +so this is not an unknown. And therefore +you can say that the y + + align:start position:0% +you can say that the y + + + align:start position:0% +you can say that the y +motion of this particle + + align:start position:0% + + + + align:start position:0% + +is + + align:start position:0% +is + + + align:start position:0% +is +e + + align:start position:0% +e + + + align:start position:0% +e +sin omega t. + + align:start position:0% + + + + align:start position:0% + +And that's a constraint. + + align:start position:0% +And that's a constraint. + + + align:start position:0% +And that's a constraint. +And the X motion + + align:start position:0% +And the X motion + + + align:start position:0% +And the X motion +is + + align:start position:0% +is + + + align:start position:0% +is +the motion of + + align:start position:0% +the motion of + + + align:start position:0% +the motion of +the + + align:start position:0% +the + + + align:start position:0% +the +main block to which it's attached + + align:start position:0% +main block to which it's attached + + + align:start position:0% +main block to which it's attached +plus an E cosine + + align:start position:0% +plus an E cosine + + + align:start position:0% +plus an E cosine +omega t. + + align:start position:0% +omega t. + + + align:start position:0% +omega t. +And that's another these are known. This + + align:start position:0% +And that's another these are known. This + + + align:start position:0% +And that's another these are known. This +is you've already accounted for this. + + align:start position:0% +is you've already accounted for this. + + + align:start position:0% +is you've already accounted for this. +That's that's the main masses motion. So + + align:start position:0% +That's that's the main masses motion. So + + + align:start position:0% +That's that's the main masses motion. So +this is something known. So these mount + + align:start position:0% +this is something known. So these mount + + + align:start position:0% +this is something known. So these mount +up each one of these. This gives you a + + align:start position:0% +up each one of these. This gives you a + + + align:start position:0% +up each one of these. This gives you a +constraint and this gives you a + + align:start position:0% +constraint and this gives you a + + + align:start position:0% +constraint and this gives you a +constraint. And so let's add them up. So + + align:start position:0% +constraint. And so let's add them up. So + + + align:start position:0% +constraint. And so let's add them up. So +two and three or five six 7 8. + + align:start position:0% +two and three or five six 7 8. + + + align:start position:0% +two and three or five six 7 8. +So you can actually completely describe + + align:start position:0% +So you can actually completely describe + + + align:start position:0% +So you can actually completely describe +the motion of this thing with one + + align:start position:0% +the motion of this thing with one + + + align:start position:0% +the motion of this thing with one +equation of motion. Okay. + + align:start position:0% + + + + align:start position:0% + +All right. + + align:start position:0% +All right. + + + align:start position:0% +All right. +So I'm seeking so I want to find + + align:start position:0% + + + + align:start position:0% + +the sum of the external forces + + align:start position:0% +the sum of the external forces + + + align:start position:0% +the sum of the external forces +on + + align:start position:0% +on + + + align:start position:0% +on +the main block + + align:start position:0% +the main block + + + align:start position:0% +the main block +in the x direction. Okay. + + align:start position:0% +in the x direction. Okay. + + + align:start position:0% +in the x direction. Okay. +And that's going to be we know that + + align:start position:0% +And that's going to be we know that + + + align:start position:0% +And that's going to be we know that +that's the mass of that block times x + + align:start position:0% +that's the mass of that block times x + + + align:start position:0% +that's the mass of that block times x +dot. So x is going to be the coordinate + + align:start position:0% +dot. So x is going to be the coordinate + + + align:start position:0% +dot. So x is going to be the coordinate +that describes the motion of that mass + + align:start position:0% +that describes the motion of that mass + + + align:start position:0% +that describes the motion of that mass +mb. + + align:start position:0% + + + + align:start position:0% + +So we need a free body diagram of MB. + + align:start position:0% + + + + align:start position:0% + +So here's the block. + + align:start position:0% + + + + align:start position:0% + +There'll be a normal force up. There's + + align:start position:0% +There'll be a normal force up. There's + + + align:start position:0% +There'll be a normal force up. There's +going to be m BG downwards. + + align:start position:0% +going to be m BG downwards. + + + align:start position:0% +going to be m BG downwards. +And the only other forces acting on this + + align:start position:0% +And the only other forces acting on this + + + align:start position:0% +And the only other forces acting on this +block are + + align:start position:0% +block are + + + align:start position:0% +block are +a force that's comes through this rod + + align:start position:0% +a force that's comes through this rod + + + align:start position:0% +a force that's comes through this rod +that's holding the + + align:start position:0% +that's holding the + + + align:start position:0% +that's holding the +that mass, the little mass. Okay. and + + align:start position:0% + + + + align:start position:0% + +and it's I'm just going to draw it at + + align:start position:0% +and it's I'm just going to draw it at + + + align:start position:0% +and it's I'm just going to draw it at +some arbitrary angle, not necessarily + + align:start position:0% +some arbitrary angle, not necessarily + + + align:start position:0% +some arbitrary angle, not necessarily +theta. It's going to be a force. + + align:start position:0% +theta. It's going to be a force. + + + align:start position:0% +theta. It's going to be a force. +I'm going to call that + + align:start position:0% +I'm going to call that + + + align:start position:0% +I'm going to call that +force + + align:start position:0% +force + + + align:start position:0% +force +on this main mass. And it's and it's a + + align:start position:0% +on this main mass. And it's and it's a + + + align:start position:0% +on this main mass. And it's and it's a +vector for the moment. It'll have two + + align:start position:0% +vector for the moment. It'll have two + + + align:start position:0% +vector for the moment. It'll have two +components in the x and y directions. + + align:start position:0% + + + + align:start position:0% + +So in order to write an equation so in + + align:start position:0% +So in order to write an equation so in + + + align:start position:0% +So in order to write an equation so in +the y direction it's trivial n is equal + + align:start position:0% +the y direction it's trivial n is equal + + + align:start position:0% +the y direction it's trivial n is equal +to you know uh mg mg in this direction + + align:start position:0% +to you know uh mg mg in this direction + + + align:start position:0% +to you know uh mg mg in this direction +we have to have to break this into two + + align:start position:0% +we have to have to break this into two + + + align:start position:0% +we have to have to break this into two +components. We need to know the + + align:start position:0% +components. We need to know the + + + align:start position:0% +components. We need to know the +component of this in the x direction and + + align:start position:0% +component of this in the x direction and + + + align:start position:0% +component of this in the x direction and +put it in here and we'll be and we'll be + + align:start position:0% +put it in here and we'll be and we'll be + + + align:start position:0% +put it in here and we'll be and we'll be +done. Okay. So + + align:start position:0% + + + + align:start position:0% + +now I'm going to use um third law. + + align:start position:0% +now I'm going to use um third law. + + + align:start position:0% +now I'm going to use um third law. +The force that that + + align:start position:0% +The force that that + + + align:start position:0% +The force that that +rod places on this body + + align:start position:0% +rod places on this body + + + align:start position:0% +rod places on this body +is equal and opposite to the force that + + align:start position:0% +is equal and opposite to the force that + + + align:start position:0% +is equal and opposite to the force that +the rod places on the mass going round + + align:start position:0% +the rod places on the mass going round + + + align:start position:0% +the rod places on the mass going round +and round. You agree with me? + + align:start position:0% +and round. You agree with me? + + + align:start position:0% +and round. You agree with me? +Okay. + + align:start position:0% +Okay. + + + align:start position:0% +Okay. +So, what we really what we need to do + + align:start position:0% +So, what we really what we need to do + + + align:start position:0% +So, what we really what we need to do +next is here's the mass up here going + + align:start position:0% +next is here's the mass up here going + + + align:start position:0% +next is here's the mass up here going +round and round and the forces on it is + + align:start position:0% +round and round and the forces on it is + + + align:start position:0% +round and round and the forces on it is +it has an mg + + align:start position:0% +it has an mg + + + align:start position:0% +it has an mg +downward and it has some force on it. + + align:start position:0% +downward and it has some force on it. + + + align:start position:0% +downward and it has some force on it. +That is the force on the little mass. + + align:start position:0% +That is the force on the little mass. + + + align:start position:0% +That is the force on the little mass. +And you're going to find that F on the + + align:start position:0% +And you're going to find that F on the + + + align:start position:0% +And you're going to find that F on the +little mass equals minus F on the + + align:start position:0% +little mass equals minus F on the + + + align:start position:0% +little mass equals minus F on the +big mass due to third law + + align:start position:0% +big mass due to third law + + + align:start position:0% +big mass due to third law +considerations. + + align:start position:0% +considerations. + + + align:start position:0% +considerations. +So all I have to do is then figure out + + align:start position:0% +So all I have to do is then figure out + + + align:start position:0% +So all I have to do is then figure out +the X component of this force, put a + + align:start position:0% +the X component of this force, put a + + + align:start position:0% +the X component of this force, put a +minus sign in front of it, and I'm + + align:start position:0% +minus sign in front of it, and I'm + + + align:start position:0% +minus sign in front of it, and I'm +basically done. + + align:start position:0% +basically done. + + + align:start position:0% +basically done. +And and to do that, I say F equals MA. I + + align:start position:0% +And and to do that, I say F equals MA. I + + + align:start position:0% +And and to do that, I say F equals MA. I +don't have time to finish that today. + + align:start position:0% +don't have time to finish that today. + + + align:start position:0% +don't have time to finish that today. +I'll show you it next time. and we'll + + align:start position:0% +I'll show you it next time. and we'll + + + align:start position:0% +I'll show you it next time. and we'll +figure out the uh equation of motion for + + align:start position:0% +figure out the uh equation of motion for + + + align:start position:0% +figure out the uh equation of motion for +this thing. Now, in in dragging all this + + align:start position:0% +this thing. Now, in in dragging all this + + + align:start position:0% +this thing. Now, in in dragging all this +stuff here today, I forgot to bring my + + align:start position:0% +stuff here today, I forgot to bring my + + + align:start position:0% +stuff here today, I forgot to bring my +muddy cards. So, you got a minute and if + + align:start position:0% +muddy cards. So, you got a minute and if + + + align:start position:0% +muddy cards. So, you got a minute and if +any of you have just a burning question + + align:start position:0% +any of you have just a burning question + + + align:start position:0% +any of you have just a burning question +you want to answer or something you + + align:start position:0% +you want to answer or something you + + + align:start position:0% +you want to answer or something you +really liked or if if you don't mind, + + align:start position:0% +really liked or if if you don't mind, + + + align:start position:0% +really liked or if if you don't mind, +just take a piece of paper, make a note + + align:start position:0% +just take a piece of paper, make a note + + + align:start position:0% +just take a piece of paper, make a note +on it, and drop it off on the way out. + + align:start position:0% +on it, and drop it off on the way out. + + + align:start position:0% +on it, and drop it off on the way out. +Thanks a lot. See you on Thursday. \ No newline at end of file diff --git a/zYcRXHYKYTI.txt b/zYcRXHYKYTI.txt new file mode 100644 index 0000000000000000000000000000000000000000..01b5e83895ed7819076b5cd426d6bd0e8685fc66 --- /dev/null +++ b/zYcRXHYKYTI.txt @@ -0,0 +1,1403 @@ +align:start position:0% + +we're going to take a look at how point + + align:start position:0% +we're going to take a look at how point + + + align:start position:0% +we're going to take a look at how point +of view and Composition + + align:start position:0% +of view and Composition + + + align:start position:0% +of view and Composition +are very clearly connected but before we + + align:start position:0% +are very clearly connected but before we + + + align:start position:0% +are very clearly connected but before we +show the connections we have to sort of + + align:start position:0% +show the connections we have to sort of + + + align:start position:0% +show the connections we have to sort of +define visually define what i mean by + + align:start position:0% +define visually define what i mean by + + + align:start position:0% +define visually define what i mean by +point of view for example so take a look + + align:start position:0% +point of view for example so take a look + + + align:start position:0% +point of view for example so take a look +at these four images now it doesn't look + + align:start position:0% +at these four images now it doesn't look + + + align:start position:0% +at these four images now it doesn't look +at it but these images are of the + + align:start position:0% +at it but these images are of the + + + align:start position:0% +at it but these images are of the +identical sample just simply taken with + + align:start position:0% +identical sample just simply taken with + + + align:start position:0% +identical sample just simply taken with +four different points of view there it's + + align:start position:0% +four different points of view there it's + + + align:start position:0% +four different points of view there it's +true that I also change the background + + align:start position:0% +true that I also change the background + + + align:start position:0% +true that I also change the background +on them but generally what I did was I + + align:start position:0% +on them but generally what I did was I + + + align:start position:0% +on them but generally what I did was I +moved the sample around or the camera + + align:start position:0% +moved the sample around or the camera + + + align:start position:0% +moved the sample around or the camera +and we get four really completely + + align:start position:0% +and we get four really completely + + + align:start position:0% +and we get four really completely +different-looking visual ideas of what + + align:start position:0% +different-looking visual ideas of what + + + align:start position:0% +different-looking visual ideas of what +this stuff was about which one is right + + align:start position:0% +this stuff was about which one is right + + + align:start position:0% +this stuff was about which one is right +I'm not sure there is a right in any of + + align:start position:0% +I'm not sure there is a right in any of + + + align:start position:0% +I'm not sure there is a right in any of +this that's one of the fun things about + + align:start position:0% +this that's one of the fun things about + + + align:start position:0% +this that's one of the fun things about +this kind of work there are no hard fast + + align:start position:0% +this kind of work there are no hard fast + + + align:start position:0% +this kind of work there are no hard fast +rules that we have to follow but I + + align:start position:0% +rules that we have to follow but I + + + align:start position:0% +rules that we have to follow but I +wanted to give this example to show you + + align:start position:0% +wanted to give this example to show you + + + align:start position:0% +wanted to give this example to show you +that just by simply changing the angle + + align:start position:0% +that just by simply changing the angle + + + align:start position:0% +that just by simply changing the angle +of your camera or moving your material + + align:start position:0% +of your camera or moving your material + + + align:start position:0% +of your camera or moving your material +around you see different things again + + align:start position:0% +around you see different things again + + + align:start position:0% +around you see different things again +we're learning to see in this course so + + align:start position:0% +we're learning to see in this course so + + + align:start position:0% +we're learning to see in this course so +in this situation I wanted to show the + + align:start position:0% +in this situation I wanted to show the + + + align:start position:0% +in this situation I wanted to show the +fabrication of this particular pyramid + + align:start position:0% +fabrication of this particular pyramid + + + align:start position:0% +fabrication of this particular pyramid +sort of telling a story in a particular + + align:start position:0% +sort of telling a story in a particular + + + align:start position:0% +sort of telling a story in a particular +image for now just take a real good look + + align:start position:0% +image for now just take a real good look + + + align:start position:0% +image for now just take a real good look +at this pyramid that was made with this + + align:start position:0% +at this pyramid that was made with this + + + align:start position:0% +at this pyramid that was made with this +wafer that was imprinted with a pattern + + align:start position:0% +wafer that was imprinted with a pattern + + + align:start position:0% +wafer that was imprinted with a pattern +and I felt that this was not quite right + + align:start position:0% +and I felt that this was not quite right + + + align:start position:0% +and I felt that this was not quite right +because there was a little ambiguity and + + align:start position:0% +because there was a little ambiguity and + + + align:start position:0% +because there was a little ambiguity and +where the pyramids point is it's a + + align:start position:0% +where the pyramids point is it's a + + + align:start position:0% +where the pyramids point is it's a +little too close to the curve of the + + align:start position:0% +little too close to the curve of the + + + align:start position:0% +little too close to the curve of the +wafer so by simply raising the camera + + align:start position:0% +wafer so by simply raising the camera + + + align:start position:0% +wafer so by simply raising the camera +ever so slightly we get it nice and + + align:start position:0% +ever so slightly we get it nice and + + + align:start position:0% +ever so slightly we get it nice and +clean line without well let's continue + + align:start position:0% +clean line without well let's continue + + + align:start position:0% +clean line without well let's continue +calling it ambiguity for the time being + + align:start position:0% +calling it ambiguity for the time being + + + align:start position:0% +calling it ambiguity for the time being +here + + align:start position:0% +here + + + align:start position:0% +here +is an example where for this particular + + align:start position:0% +is an example where for this particular + + + align:start position:0% +is an example where for this particular +device of micro rotor I shot it from + + align:start position:0% +device of micro rotor I shot it from + + + align:start position:0% +device of micro rotor I shot it from +above because I was using a + + align:start position:0% +above because I was using a + + + align:start position:0% +above because I was using a +stereomicroscope I had this brand new + + align:start position:0% +stereomicroscope I had this brand new + + + align:start position:0% +stereomicroscope I had this brand new +piece of equipment that I had to use of + + align:start position:0% +piece of equipment that I had to use of + + + align:start position:0% +piece of equipment that I had to use of +course because it's brand new and from + + align:start position:0% +course because it's brand new and from + + + align:start position:0% +course because it's brand new and from +that point of view very unfortunately + + align:start position:0% +that point of view very unfortunately + + + align:start position:0% +that point of view very unfortunately +you see all kinds of dust and yuck which + + align:start position:0% +you see all kinds of dust and yuck which + + + align:start position:0% +you see all kinds of dust and yuck which +I could not get rid of because I don't + + align:start position:0% +I could not get rid of because I don't + + + align:start position:0% +I could not get rid of because I don't +have control over the light so I simply + + align:start position:0% +have control over the light so I simply + + + align:start position:0% +have control over the light so I simply +changed back to my camera and my one of + + align:start position:0% +changed back to my camera and my one of + + + align:start position:0% +changed back to my camera and my one of +five lens with a different point of view + + align:start position:0% +five lens with a different point of view + + + align:start position:0% +five lens with a different point of view +which gave me a much cleaner image many + + align:start position:0% +which gave me a much cleaner image many + + + align:start position:0% +which gave me a much cleaner image many +times we get stuck on a particular + + align:start position:0% +times we get stuck on a particular + + + align:start position:0% +times we get stuck on a particular +approach to looking at things let's say + + align:start position:0% +approach to looking at things let's say + + + align:start position:0% +approach to looking at things let's say +directly from above and it doesn't + + align:start position:0% +directly from above and it doesn't + + + align:start position:0% +directly from above and it doesn't +necessarily give the best image here's + + align:start position:0% +necessarily give the best image here's + + + align:start position:0% +necessarily give the best image here's +an example where this is a pdms that's + + align:start position:0% +an example where this is a pdms that's + + + align:start position:0% +an example where this is a pdms that's +been etched with a grading on it and I + + align:start position:0% +been etched with a grading on it and I + + + align:start position:0% +been etched with a grading on it and I +took it with this particular view and + + align:start position:0% +took it with this particular view and + + + align:start position:0% +took it with this particular view and +just by simply changing the pdms to a + + align:start position:0% +just by simply changing the pdms to a + + + align:start position:0% +just by simply changing the pdms to a +slightly different position we get a + + align:start position:0% +slightly different position we get a + + + align:start position:0% +slightly different position we get a +different point of view let's go back + + align:start position:0% +different point of view let's go back + + + align:start position:0% +different point of view let's go back +and forth on this and see it's kind of + + align:start position:0% +and forth on this and see it's kind of + + + align:start position:0% +and forth on this and see it's kind of +fun to do this anyway but you'll notice + + align:start position:0% +fun to do this anyway but you'll notice + + + align:start position:0% +fun to do this anyway but you'll notice +that you really this one has a better + + align:start position:0% +that you really this one has a better + + + align:start position:0% +that you really this one has a better +approach to looking at the refraction + + align:start position:0% +approach to looking at the refraction + + + align:start position:0% +approach to looking at the refraction +but at the same time you notice when we + + align:start position:0% +but at the same time you notice when we + + + align:start position:0% +but at the same time you notice when we +I did that the shadow is changing in its + + align:start position:0% +I did that the shadow is changing in its + + + align:start position:0% +I did that the shadow is changing in its +position again this is encouraging you + + align:start position:0% +position again this is encouraging you + + + align:start position:0% +position again this is encouraging you +to understand that when you change your + + align:start position:0% +to understand that when you change your + + + align:start position:0% +to understand that when you change your +point of view of course you're also + + align:start position:0% +point of view of course you're also + + + align:start position:0% +point of view of course you're also +changing your composition in this + + align:start position:0% +changing your composition in this + + + align:start position:0% +changing your composition in this +situation I had a petri dish with + + align:start position:0% +situation I had a petri dish with + + + align:start position:0% +situation I had a petri dish with +various gels that had different colors + + align:start position:0% +various gels that had different colors + + + align:start position:0% +various gels that had different colors +let's just leave it at that for the time + + align:start position:0% +let's just leave it at that for the time + + + align:start position:0% +let's just leave it at that for the time +being this was my primary initial point + + align:start position:0% +being this was my primary initial point + + + align:start position:0% +being this was my primary initial point +of view and I thought it was kind of + + align:start position:0% +of view and I thought it was kind of + + + align:start position:0% +of view and I thought it was kind of +boring and so the point of view was a + + align:start position:0% +boring and so the point of view was a + + + align:start position:0% +boring and so the point of view was a +little tighter in that I chose to get + + align:start position:0% +little tighter in that I chose to get + + + align:start position:0% +little tighter in that I chose to get +the camera closer and I + + align:start position:0% +the camera closer and I + + + align:start position:0% +the camera closer and I +also included different kinds of gels in + + align:start position:0% +also included different kinds of gels in + + + align:start position:0% +also included different kinds of gels in +this situation larger ones it is a + + align:start position:0% +this situation larger ones it is a + + + align:start position:0% +this situation larger ones it is a +different point of view in terms of your + + align:start position:0% +different point of view in terms of your + + + align:start position:0% +different point of view in terms of your +selection of what it is that you are + + align:start position:0% +selection of what it is that you are + + + align:start position:0% +selection of what it is that you are +going to be showing so these are not + + align:start position:0% +going to be showing so these are not + + + align:start position:0% +going to be showing so these are not +very deep changes but enough to make + + align:start position:0% +very deep changes but enough to make + + + align:start position:0% +very deep changes but enough to make +very very different images as for + + align:start position:0% +very very different images as for + + + align:start position:0% +very very different images as for +example this one which is a glass wafer + + align:start position:0% +example this one which is a glass wafer + + + align:start position:0% +example this one which is a glass wafer +that's been etched so that they're + + align:start position:0% +that's been etched so that they're + + + align:start position:0% +that's been etched so that they're +creating channels on the wafer from this + + align:start position:0% +creating channels on the wafer from this + + + align:start position:0% +creating channels on the wafer from this +point of view and here is another point + + align:start position:0% +point of view and here is another point + + + align:start position:0% +point of view and here is another point +of view where I'm not showing the whole + + align:start position:0% +of view where I'm not showing the whole + + + align:start position:0% +of view where I'm not showing the whole +thing and maybe we don't have to show + + align:start position:0% +thing and maybe we don't have to show + + + align:start position:0% +thing and maybe we don't have to show +the whole thing all the time maybe we + + align:start position:0% +the whole thing all the time maybe we + + + align:start position:0% +the whole thing all the time maybe we +can show the work by something that is + + align:start position:0% +can show the work by something that is + + + align:start position:0% +can show the work by something that is +in my opinion a more interesting + + align:start position:0% +in my opinion a more interesting + + + align:start position:0% +in my opinion a more interesting +composition and a different point of + + align:start position:0% +composition and a different point of + + + align:start position:0% +composition and a different point of +view here a small change take a look at + + align:start position:0% +view here a small change take a look at + + + align:start position:0% +view here a small change take a look at +both of these and I hope you see that in + + align:start position:0% +both of these and I hope you see that in + + + align:start position:0% +both of these and I hope you see that in +the first one it was a bit of a sloppy + + align:start position:0% +the first one it was a bit of a sloppy + + + align:start position:0% +the first one it was a bit of a sloppy +point of view in the sense that i'm + + align:start position:0% +point of view in the sense that i'm + + + align:start position:0% +point of view in the sense that i'm +showing labels that really is not + + align:start position:0% +showing labels that really is not + + + align:start position:0% +showing labels that really is not +something of value and so by simply + + align:start position:0% +something of value and so by simply + + + align:start position:0% +something of value and so by simply +moving the camera slightly then focusing + + align:start position:0% +moving the camera slightly then focusing + + + align:start position:0% +moving the camera slightly then focusing +a little closer it's a cleaner point of + + align:start position:0% +a little closer it's a cleaner point of + + + align:start position:0% +a little closer it's a cleaner point of +view again this is also about God + + align:start position:0% +view again this is also about God + + + align:start position:0% +view again this is also about God +position but they are very much + + align:start position:0% +position but they are very much + + + align:start position:0% +position but they are very much +connected here is this researchers point + + align:start position:0% +connected here is this researchers point + + + align:start position:0% +connected here is this researchers point +of view where he decided to show the + + align:start position:0% +of view where he decided to show the + + + align:start position:0% +of view where he decided to show the +flexibility of this material and include + + align:start position:0% +flexibility of this material and include + + + align:start position:0% +flexibility of this material and include +hands which is a good idea when you want + + align:start position:0% +hands which is a good idea when you want + + + align:start position:0% +hands which is a good idea when you want +to show scale for me I decided to be a + + align:start position:0% +to show scale for me I decided to be a + + + align:start position:0% +to show scale for me I decided to be a +little more playful and just playing + + align:start position:0% +little more playful and just playing + + + align:start position:0% +little more playful and just playing +more around the flexibility in showing + + align:start position:0% +more around the flexibility in showing + + + align:start position:0% +more around the flexibility in showing +the shadows of it and we did get a cover + + align:start position:0% +the shadows of it and we did get a cover + + + align:start position:0% +the shadows of it and we did get a cover +of a journal which was nice whole + + align:start position:0% +of a journal which was nice whole + + + align:start position:0% +of a journal which was nice whole +different point of view same material + + align:start position:0% +different point of view same material + + + align:start position:0% +different point of view same material +both are good you know there's not again + + align:start position:0% +both are good you know there's not again + + + align:start position:0% +both are good you know there's not again +it not one is better than the other + + align:start position:0% +it not one is better than the other + + + align:start position:0% +it not one is better than the other +necessarily i decided + + align:start position:0% +necessarily i decided + + + align:start position:0% +necessarily i decided +to dig out from the depths of my slide + + align:start position:0% +to dig out from the depths of my slide + + + align:start position:0% +to dig out from the depths of my slide +collection when i was an architectural + + align:start position:0% +collection when i was an architectural + + + align:start position:0% +collection when i was an architectural +photographer to show you a difference + + align:start position:0% +photographer to show you a difference + + + align:start position:0% +photographer to show you a difference +that does somewhat inform us in this + + align:start position:0% +that does somewhat inform us in this + + + align:start position:0% +that does somewhat inform us in this +course here's a beautiful space in + + align:start position:0% +course here's a beautiful space in + + + align:start position:0% +course here's a beautiful space in +california designed by the simone Iguchi + + align:start position:0% +california designed by the simone Iguchi + + + align:start position:0% +california designed by the simone Iguchi +this is the first image that I made and + + align:start position:0% +this is the first image that I made and + + + align:start position:0% +this is the first image that I made and +here is the second image that I made + + align:start position:0% +here is the second image that I made + + + align:start position:0% +here is the second image that I made +let's go back and forth a little on this + + align:start position:0% +let's go back and forth a little on this + + + align:start position:0% +let's go back and forth a little on this +as well and you see in this second image + + align:start position:0% +as well and you see in this second image + + + align:start position:0% +as well and you see in this second image +I decided to have the camera points + + align:start position:0% +I decided to have the camera points + + + align:start position:0% +I decided to have the camera points +slightly upward of changing the point of + + align:start position:0% +slightly upward of changing the point of + + + align:start position:0% +slightly upward of changing the point of +view so that we see a slant of sky I + + align:start position:0% +view so that we see a slant of sky I + + + align:start position:0% +view so that we see a slant of sky I +think this is a better image I think + + align:start position:0% +think this is a better image I think + + + align:start position:0% +think this is a better image I think +it's more interesting but I also think + + align:start position:0% +it's more interesting but I also think + + + align:start position:0% +it's more interesting but I also think +that it allows the viewer to sort of + + align:start position:0% +that it allows the viewer to sort of + + + align:start position:0% +that it allows the viewer to sort of +parties paid more in the image that is + + align:start position:0% +parties paid more in the image that is + + + align:start position:0% +parties paid more in the image that is +to kind of go along upward and be part + + align:start position:0% +to kind of go along upward and be part + + + align:start position:0% +to kind of go along upward and be part +of paying attention to what is going on + + align:start position:0% +of paying attention to what is going on + + + align:start position:0% +of paying attention to what is going on +with the sky I think showing the edges + + align:start position:0% +with the sky I think showing the edges + + + align:start position:0% +with the sky I think showing the edges +and the connection between the edge and + + align:start position:0% +and the connection between the edge and + + + align:start position:0% +and the connection between the edge and +something beyond is an interesting view + + align:start position:0% +something beyond is an interesting view + + + align:start position:0% +something beyond is an interesting view +of how to show things as I did hear back + + align:start position:0% +of how to show things as I did hear back + + + align:start position:0% +of how to show things as I did hear back +to our world when I needed to show + + align:start position:0% +to our world when I needed to show + + + align:start position:0% +to our world when I needed to show +bubbles for a book that we did I decided + + align:start position:0% +bubbles for a book that we did I decided + + + align:start position:0% +bubbles for a book that we did I decided +to keep the edge of the plate showing + + align:start position:0% +to keep the edge of the plate showing + + + align:start position:0% +to keep the edge of the plate showing +and show the background it is a point of + + align:start position:0% +and show the background it is a point of + + + align:start position:0% +and show the background it is a point of +view that I felt sort of worked in here + + align:start position:0% +view that I felt sort of worked in here + + + align:start position:0% +view that I felt sort of worked in here +is another point of view with the same + + align:start position:0% +is another point of view with the same + + + align:start position:0% +is another point of view with the same +material which is better I the + + align:start position:0% +material which is better I the + + + align:start position:0% +material which is better I the +interested to hear your opinions here + + align:start position:0% +interested to hear your opinions here + + + align:start position:0% +interested to hear your opinions here +is a device with the researchers point + + align:start position:0% +is a device with the researchers point + + + align:start position:0% +is a device with the researchers point +of view of it and this is my point of + + align:start position:0% +of view of it and this is my point of + + + align:start position:0% +of view of it and this is my point of +view where I first of all like to get it + + align:start position:0% +view where I first of all like to get it + + + align:start position:0% +view where I first of all like to get it +in focus but since we're talking about + + align:start position:0% +in focus but since we're talking about + + + align:start position:0% +in focus but since we're talking about +point of view I'll stay with that and + + align:start position:0% +point of view I'll stay with that and + + + align:start position:0% +point of view I'll stay with that and +all I did was I put it on a white + + align:start position:0% +all I did was I put it on a white + + + align:start position:0% +all I did was I put it on a white +background and I just slanted the device + + align:start position:0% +background and I just slanted the device + + + align:start position:0% +background and I just slanted the device +and the camera of this point of view and + + align:start position:0% +and the camera of this point of view and + + + align:start position:0% +and the camera of this point of view and +I think it's a much more successful + + align:start position:0% +I think it's a much more successful + + + align:start position:0% +I think it's a much more successful +picture and finally + + align:start position:0% +picture and finally + + + align:start position:0% +picture and finally +in this situation when you do have a + + align:start position:0% +in this situation when you do have a + + + align:start position:0% +in this situation when you do have a +device that is almost pretty much + + align:start position:0% +device that is almost pretty much + + + align:start position:0% +device that is almost pretty much +symmetrical if you're going to take a + + align:start position:0% +symmetrical if you're going to take a + + + align:start position:0% +symmetrical if you're going to take a +photograph from above you just better + + align:start position:0% +photograph from above you just better + + + align:start position:0% +photograph from above you just better +make sure that you make the image + + align:start position:0% +make sure that you make the image + + + align:start position:0% +make sure that you make the image +symmetrical as well take a look at this + + align:start position:0% +symmetrical as well take a look at this + + + align:start position:0% +symmetrical as well take a look at this +first one again and you know there's + + align:start position:0% +first one again and you know there's + + + align:start position:0% +first one again and you know there's +nothing worse than an almost okay image + + align:start position:0% +nothing worse than an almost okay image + + + align:start position:0% +nothing worse than an almost okay image +if it were really really off symmetry + + align:start position:0% +if it were really really off symmetry + + + align:start position:0% +if it were really really off symmetry +that would work better than just a tad + + align:start position:0% +that would work better than just a tad + + + align:start position:0% +that would work better than just a tad +off symmetry so my suggestion is to if + + align:start position:0% +off symmetry so my suggestion is to if + + + align:start position:0% +off symmetry so my suggestion is to if +you do decide to make a symmetrical like + + align:start position:0% +you do decide to make a symmetrical like + + + align:start position:0% +you do decide to make a symmetrical like +image just make sure it is a symmetrical + + align:start position:0% +image just make sure it is a symmetrical + + + align:start position:0% +image just make sure it is a symmetrical +point of view \ No newline at end of file